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Sample records for stage direct coupled

  1. Directionality of coupling of physiological subsystems: age-related changes of cardiorespiratory interaction during different sleep stages in babies.

    Science.gov (United States)

    Mrowka, Ralf; Cimponeriu, Laura; Patzak, Andreas; Rosenblum, Michael G

    2003-12-01

    Activity of many physiological subsystems has a well-expressed rhythmic character. Often, a dependency between physiological rhythms is established due to interaction between the corresponding subsystems. Traditional methods of data analysis allow one to quantify the strength of interaction but not the causal interrelation that is indispensable for understanding the mechanisms of interaction. Here we present a recently developed method for quantification of coupling direction and apply it to an important problem. Namely, we study the mutual influence of respiratory and cardiovascular rhythms in healthy newborns within the first 6 mo of life in quiet and active sleep. We find an age-related change of the coupling direction: the interaction is nearly symmetric during the first days and becomes practically unidirectional (from respiration to heart rhythm) at the age of 6 mo. Next, we show that the direction of interaction is mainly determined by respiratory frequency. If the latter is less than approximately 0.6 Hz, the interaction occurs dominantly from respiration to heart. With higher respiratory frequencies that only occur at very young ages, the dominating direction is less pronounced or even abolished. The observed dependencies are not related to sleep stage, suggesting that the coupling direction is determined by system-inherent dynamical processes, rather than by functional modulations. The directional analysis may be applied to other interacting narrow band oscillatory systems, e.g., in the central nervous system. Thus it is an important step forward in revealing and understanding causal mechanisms of interactions.

  2. Direction selective structural-acoustic coupled radiator

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-04-01

    This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

  3. Identification of coupling direction: Application to cardiorespiratory interaction

    Science.gov (United States)

    Rosenblum, Michael G.; Cimponeriu, Laura; Bezerianos, Anastasios; Patzak, Andreas; Mrowka, Ralf

    2002-04-01

    We consider the problem of experimental detection of directionality of weak coupling between two self-sustained oscillators from bivariate data. We further develop the method introduced by Rosenblum and Pikovsky [Phys. Rev. E 64, 045202 (2001)], suggesting an alternative approach. Next, we consider another framework for identification of directionality, based on the idea of mutual predictability. Our algorithms provide directionality index that shows whether the coupling between the oscillators is unidirectional or bidirectional, and quantifies the asymmetry of bidirectional coupling. We demonstrate the efficiency of three different algorithms in determination of directionality index from short and noisy data. These techniques are then applied to analysis of cardiorespiratory interaction in healthy infants. The results reveal that the direction of coupling between cardiovascular and respiratory systems varies with the age within the first 6 months of life. We find a tendency to change from nearly symmetric bidirectional interaction to nearly unidirectional one (from respiration to the cardiovascular system).

  4. Semi-direct sums of Lie algebras and continuous integrable couplings

    International Nuclear Information System (INIS)

    Ma Wenxiu; Xu Xixiang; Zhang Yufeng

    2006-01-01

    A relation between semi-direct sums of Lie algebras and integrable couplings of continuous soliton equations is presented, and correspondingly, a feasible way to construct integrable couplings is furnished. A direct application to the AKNS spectral problem leads to a novel hierarchy of integrable couplings of the AKNS hierarchy of soliton equations. It is also indicated that the study of integrable couplings using semi-direct sums of Lie algebras is an important step towards complete classification of integrable systems

  5. Performance of a directly-coupled PV water pumping system

    International Nuclear Information System (INIS)

    Mokeddem, Abdelmalek; Midoun, Abdelhamid; Kadri, D.; Hiadsi, Said; Raja, Iftikhar A.

    2011-01-01

    Highlights: → Directly coupled PV water pumping system installed and performance studied. → Configured for two static heads, operate without electronic control and auxiliary power. → The system attains steady state soon after any abrupt change. → Cost effective and useful for low head communicating wells system. - Abstract: This paper describes the experimental study carried out to investigate the performance of a simple, directly coupled dc photovoltaic (PV) powered water pumping system. The system comprises of a 1.5 kWp PV array, dc motor and a centrifugal pump. The experiment was conducted over a period of 4 months and the system performance was monitored under different climatic conditions and varying solar irradiance with two static head configurations. Although the motor-pump efficiency did not exceed 30%, which is typical for directly-coupled photovoltaic pumping systems, such a system is clearly suitable for low head irrigation in the remote areas, not connected to the national grid and where access to water comes as first priority issue than access to technology. The system operates without battery and complex electronic control, therefore not only the initial cost is low but also maintenance, repairing and replacement cost can be saved. The study showed that directly coupled system attains steady state soon after any abrupt change.

  6. Minimizing coupling loss by selection of twist pitch lengths in multi-stage cable-in-conduit conductors

    International Nuclear Information System (INIS)

    Rolando, G; Nijhuis, A; Devred, A

    2014-01-01

    The numerical code JackPot-ACDC (van Lanen et al 2010 Cryogenics 50 139–48, van Lanen et al 2011 IEEE Trans. Appl. Supercond. 21 1926–9, van Lanen et al 2012 Supercond. Sci. Technol. 25 025012) allows fast parametric studies of the electro-magnetic performance of cable-in-conduit conductors (CICCs). In this paper the code is applied to the analysis of the relation between twist pitch length sequence and coupling loss in multi-stage ITER-type CICCs. The code shows that in the analysed conductors the coupling loss is at its minimum when the twist pitches of the successive cabling stages have a length ratio close to one. It is also predicted that by careful selection of the stage-to-stage twist pitch ratio, CICCs cabled according to long twist schemes in the initial stages can achieve lower coupling loss than conductors with shorter pitches. The result is validated by AC loss measurements performed on prototype conductors for the ITER Central Solenoid featuring different twist pitch sequences. (paper)

  7. A coupling model for the two-stage core calculation method with subchannel analysis for boiling water reactors

    International Nuclear Information System (INIS)

    Mitsuyasu, Takeshi; Aoyama, Motoo; Yamamoto, Akio

    2017-01-01

    Highlights: • A coupling model of the two-stage core calculation with subchannel analysis. • BWR fuel assembly parameters are assumed and verified. • The model was evaluated for heterogeneous problems. - Abstract: The two-stage core analysis method is widely used for BWR core analysis. The purpose of this study is to develop a core analysis model coupled with subchannel analysis within the two-stage calculation scheme using an assembly-based thermal-hydraulics calculation in the core analysis. The model changes the 2D lattice physics scheme, and couples with 3D subchannel analysis which evaluates the thermal-hydraulics characteristics within the coolant flow area divided as some subchannel regions. In order to couple with these two analyses, some BWR fuel assembly parameters are assumed and verified. The developed model is evaluated for the heterogeneous problem with and without a control rod. The present model is especially effective for the control rod inserted condition. The present model can incorporate the subchannel effect into the current two-stage core calculation method.

  8. Couple-Focused Group Intervention for Women With Early Stage Breast Cancer

    Science.gov (United States)

    Manne, Sharon L.; Ostroff, Jamie S.; Winkel, Gary; Fox, Kevin; Grana, Generosa; Miller, Eric; Ross, Stephanie; Frazier, Thomas

    2005-01-01

    This study examined the efficacy of a couple-focused group intervention on psychological adaptation of women with early stage breast cancer and evaluated whether perceived partner unsupportive behavior or patient functional impairment moderated intervention effects. Two hundred thirty-eight women were randomly assigned to receive either 6 sessions…

  9. On-chip spin-controlled orbital angular momentum directional coupling

    Science.gov (United States)

    Xie, Zhenwei; Lei, Ting; Si, Guangyuan; Du, Luping; Lin, Jiao; Min, Changjun; Yuan, Xiaocong

    2018-01-01

    Optical vortex beams have many potential applications in the particle trapping, quantum encoding, optical orbital angular momentum (OAM) communications and interconnects. However, the on-chip compact OAM detection is still a big challenge. Based on a holographic configuration and a spin-dependent structure design, we propose and demonstrate an on-chip spin-controlled OAM-mode directional coupler, which can couple the OAM signal to different directions due to its topological charge. While the directional coupling function can be switched on/off by altering the spin of incident beam. Both simulation and experimental measurements verify the validity of the proposed approach. This work would benefit the on-chip OAM devices for optical communications and high dimensional quantum coding/decoding in the future.

  10. Response and Uniformity Studies of Directly Coupled Tiles

    International Nuclear Information System (INIS)

    Zutshi, Vishnu

    2010-01-01

    A finely-segmented scintillator-based calorimeter which capitalizes on the marriage of proven detection techniques with novel solid-state photo-detector devices such as Multi-pixel Photon Counters (MPPCs) is an interesting calorimetric system from the point of view of future detector design. A calorimeter system consisting of millions of channels will require a high degree of integration. The first steps towards this integration have already been facilitated by the small size and magnetic field immunity of the MPPCs. The photo-conversion occurs right at the tile, thus obviating the need for routing of long clear fibers. Similar considerations apply to the presence of wave-length shifting (WLS) fibers inside the tiles which couple it to the photo-detectors. Significant simplification in construction and assembly ensue if the MPPCs can be coupled directly to the scintillator tiles. Equally importantly, the total absence of fibers would offer greater flexibility in the choice of the transverse segmentation while enhancing the electro-mechanical integrability of the design. The NIU high-energy physics group has been studying the fiberless or direct-coupling option for some time now. Encouraging results on response and response uniformity have been obtained using radioactive sources. This MOU seeks to set up a framework to extend these tests using beams at the MTBF. The results will be relevant to high granularity scintillator/crystal electromagnetic and hadronic calorimetry. The tests involve a set of small directly-coupled tile counters fabricated at NIU which will be placed in the beam to study their response and response uniformity as a function of the incident position of the particles passing through them.

  11. Response and Uniformity Studies of Directly Coupled Tiles

    Energy Technology Data Exchange (ETDEWEB)

    Zutshi, Vishnu

    2010-04-02

    A finely-segmented scintillator-based calorimeter which capitalizes on the marriage of proven detection techniques with novel solid-state photo-detector devices such as Multi-pixel Photon Counters (MPPCs) is an interesting calorimetric system from the point of view of future detector design. A calorimeter system consisting of millions of channels will require a high degree of integration. The first steps towards this integration have already been facilitated by the small size and magnetic field immunity of the MPPCs. The photo-conversion occurs right at the tile, thus obviating the need for routing of long clear fibers. Similar considerations apply to the presence of wave-length shifting (WLS) fibers inside the tiles which couple it to the photo-detectors. Significant simplification in construction and assembly ensue if the MPPCs can be coupled directly to the scintillator tiles. Equally importantly, the total absence of fibers would offer greater flexibility in the choice of the transverse segmentation while enhancing the electro-mechanical integrability of the design. The NIU high-energy physics group has been studying the fiberless or direct-coupling option for some time now. Encouraging results on response and response uniformity have been obtained using radioactive sources. This MOU seeks to set up a framework to extend these tests using beams at the MTBF. The results will be relevant to high granularity scintillator/crystal electromagnetic and hadronic calorimetry. The tests involve a set of small directly-coupled tile counters fabricated at NIU which will be placed in the beam to study their response and response uniformity as a function of the incident position of the particles passing through them.

  12. Direct optical measurement of light coupling into planar waveguide by plasmonic nanoparticles.

    Science.gov (United States)

    Pennanen, Antti M; Toppari, J Jussi

    2013-01-14

    Coupling of light into a thin layer of high refractive index material by plasmonic nanoparticles has been widely studied for application in photovoltaic devices, such as thin-film solar cells. In numerous studies this coupling has been investigated through measurement of e.g. quantum efficiency or photocurrent enhancement. Here we present a direct optical measurement of light coupling into a waveguide by plasmonic nanoparticles. We investigate the coupling efficiency into the guided modes within the waveguide by illuminating the surface of a sample, consisting of a glass slide coated with a high refractive index planar waveguide and plasmonic nanoparticles, while directly measuring the intensity of the light emitted out of the waveguide edge. These experiments were complemented by transmittance and reflectance measurements. We show that the light coupling is strongly affected by thin-film interference, localized surface plasmon resonances of the nanoparticles and the illumination direction (front or rear).

  13. Shape Optimization of the Assisted Bi-directional Glenn surgery for stage-1 single ventricle palliation

    Science.gov (United States)

    Verma, Aekaansh; Shang, Jessica; Esmaily-Moghadam, Mahdi; Wong, Kwai; Marsden, Alison

    2016-11-01

    Babies born with a single functional ventricle typically undergo three open-heart surgeries starting as neonates. The first of these stages (BT shunt or Norwood) has the highest mortality rates of the three, approaching 30%. Proceeding directly to a stage-2 Glenn surgery has historically demonstrated inadequate pulmonary flow (PF) & high mortality. Recently, the Assisted Bi-directional Glenn (ABG) was proposed as a promising means to achieve a stable physiology by assisting the PF via an 'ejector pump' from the systemic circulation. We present preliminary parametrization and optimization results for the ABG geometry, with the goal of increasing PF. To limit excessive pressure increases in the Superior Vena Cava (SVC), the SVC pressure is included as a constraint. We use 3-D finite element flow simulations coupled with a single ventricle lumped parameter network to evaluate PF & the pressure constraint. We employ a derivative free optimization method- the Surrogate Management Framework, in conjunction with the OpenDIEL framework to simulate multiple simultaneous evaluations. Results show that nozzle diameter is the most important design parameter affecting ABG performance. The application of these results to patient specific situations will be discussed. This work was supported by an NSF CAREER award (OCI1150184) and by the XSEDE National Computing Resource.

  14. Direct determinations of the πNN coupling constants

    International Nuclear Information System (INIS)

    Ericson, T.E.O.; ); Loiseau, B.

    1998-01-01

    A novel extrapolation method has been used to deduce directly the charged πNN coupling constant from backward np differential scattering cross sections. The extracted value, g c 2 = 14.52(026)is higher than the indirectly deduced values obtained in nucleon-nucleon energy-dependent partial-wave analyses. Our preliminary direct value from a reanalysis of the GMO sum-rule points to an intermediate value of g c 2 about 13.97(30). (author)

  15. Couples' Support-Related Communication, Psychological Distress, and Relationship Satisfaction among Women with Early Stage Breast Cancer

    Science.gov (United States)

    Manne, Sharon; Sherman, Marne; Ross, Stephanie; Ostroff, Jamie; Heyman, Richard E.; Fox, Kevin

    2004-01-01

    This study examined associations between couple communication about cancer and psychological distress and relationship satisfaction of women diagnosed with early stage breast cancer. One hundred forty-eight couples completed a videotaped discussion of a cancer-related issue and a general issue. Patients completed measures of psychological distress…

  16. Stages of Learning during a Self-Directed Stress Management Experience

    Science.gov (United States)

    Larson, Karl L.

    2015-01-01

    Purpose: The purpose of the study was to document the stages of learning reflected through student journaling during a self-directed experience in stress management, and the relationship of those stages to a historical model. Methods: College students participating in a full-semester course in stress management theory were required to select a…

  17. Photonic crystal fiber design for broadband directional coupling

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bang, Ole; Bjarklev, Anders Overgaard

    2004-01-01

    A novel design for a broadband directional coupler based on a photonic crystal fiber is investigated numerically. It is shown that suitable index-depressing doping of the core regions in an index-guiding twin-core photonic crystal fiber can stabilize the coupling coefficient between the cores over...

  18. Directional synthetic aperture flow imaging using a dual stage beamformer approach

    DEFF Research Database (Denmark)

    Li, Ye; Jensen, Jørgen Arendt

    2011-01-01

    . The new method has been studied using the Field II simulations and experimental flow rig measurements. A linear array transducer with 7 MHz center frequency is used, and 64 elements are active to transmit and receive signals. The data is processed in two stages. The first stage has a fixed focus point......A new method for directional synthetic aperture flow imaging using a dual stage beamformer approach is presented. The velocity estimation is angle independent and the amount of calculations is reduced compared to full synthetic aperture, but still maintains all the advantages at the same time....... In the second stage, focal points are considered as virtual sources and data is beamformed along the flow direction. Then the velocities are estimated by finding the spatial shift between two signals. In the experimental measurements the angle between the transmit beam and flow vessel was 70 and a laminar flow...

  19. Geometric detection of coupling directions by means of inter-system recurrence networks

    International Nuclear Information System (INIS)

    Feldhoff, Jan H.; Donner, Reik V.; Donges, Jonathan F.; Marwan, Norbert; Kurths, Jürgen

    2012-01-01

    We introduce a geometric method for identifying the coupling direction between two dynamical systems based on a bivariate extension of recurrence network analysis. Global characteristics of the resulting inter-system recurrence networks provide a correct discrimination for weakly coupled Rössler oscillators not yet displaying generalised synchronisation. Investigating two real-world palaeoclimate time series representing the variability of the Asian monsoon over the last 10,000 years, we observe indications for a considerable influence of the Indian summer monsoon on climate in Eastern China rather than vice versa. The proposed approach can be directly extended to studying K>2 coupled subsystems.

  20. Coupling effect and control strategies of the maglev dual-stage inertially stabilization system based on frequency-domain analysis.

    Science.gov (United States)

    Lin, Zhuchong; Liu, Kun; Zhang, Li; Zeng, Delin

    2016-09-01

    Maglev dual-stage inertially stabilization (MDIS) system is a newly proposed system which combines a conventional two-axis gimbal assembly and a 5-DOF (degree of freedom) magnetic bearing with vernier tilting capacity to perform dual-stage stabilization for the LOS of the suspended optical instrument. Compared with traditional dual-stage system, maglev dual-stage system exhibits different characteristics due to the negative position stiffness of the magnetic forces, which introduces additional coupling in the dual stage control system. In this paper, the coupling effect on the system performance is addressed based on frequency-domain analysis, including disturbance rejection, fine stage saturation and coarse stage structural resonance suppression. The difference between various control strategies is also discussed, including pile-up(PU), stabilize-follow (SF) and stabilize-compensate (SC). A number of principles for the design of a maglev dual stage system are proposed. A general process is also suggested, which leads to a cost-effective design striking a balance between high performance and complexity. At last, a simulation example is presented to illustrate the arguments in the paper. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Direction of coupling from phases of interacting oscillators: An information-theoretic approach

    Science.gov (United States)

    Paluš, Milan; Stefanovska, Aneta

    2003-05-01

    A directionality index based on conditional mutual information is proposed for application to the instantaneous phases of weakly coupled oscillators. Its abilities to distinguish unidirectional from bidirectional coupling, as well as to reveal and quantify asymmetry in bidirectional coupling, are demonstrated using numerical examples of quasiperiodic, chaotic, and noisy oscillators, as well as real human cardiorespiratory data.

  2. Directional multimode coupler for planar magnonics: Side-coupled magnetic stripes

    Energy Technology Data Exchange (ETDEWEB)

    Sadovnikov, A. V., E-mail: sadovnikovav@gmail.com; Nikitov, S. A. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation); Kotel' nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow 125009 (Russian Federation); Beginin, E. N.; Sheshukova, S. E.; Romanenko, D. V.; Sharaevskii, Yu. P. [Laboratory “Metamaterials,” Saratov State University, Saratov 410012 (Russian Federation)

    2015-11-16

    We experimentally demonstrate spin waves coupling in two laterally adjacent magnetic stripes. By the means of Brillouin light scattering spectroscopy, we show that the coupling efficiency depends both on the magnonic waveguides' geometry and the characteristics of spin-wave modes. In particular, the lateral confinement of coupled yttrium-iron-garnet stripes enables the possibility of control over the spin-wave propagation characteristics. Numerical simulations (in time domain and frequency domain) reveal the nature of intermodal coupling between two magnonic stripes. The proposed topology of multimode magnonic coupler can be utilized as a building block for fabrication of integrated parallel functional and logic devices such as the frequency selective directional coupler or tunable splitter, enabling a number of potential applications for planar magnonics.

  3. Initialization method for triple-layer exchanged coupled direct overwrite MO disk (abstract)

    Science.gov (United States)

    Hatwar, T. K.; Genova, D. J.; Palumbo, A. C.

    1993-05-01

    Increasing efforts are directed at the development of direct overwrite (DOW) capability for achieving higher data transfer rate in MO media. DOW by light intensity modulation on a triple-layer medium has shown great promise. The three layers consist of memory, reference, and intermediate layers that are weakly coupled to each other. This scheme uses an auxiliary magnet to initialize the reference layer in one direction in addition to the bias magnet. DOW is between high and low power levels. High power aligns the magnetization of the coupled layers in one direction, and low power aligns the magnetization in the opposite direction. These high (Ph) and low (Pl) powers are generally widely separated. Since the focused writing beam has a Gaussian profile, when the center of the spot does the high power writing, the ``skirt'' is actually doing the low power writing. As a result, if the background is initialized in the direction of the high power written mark, a chain-like domain pattern is observed. This leads to high writing noise. We found that such writing noise can be eliminated by initializing the background in the direction of the low power written marks. We will discuss the spin structure in exchanged coupled triple-layer films and the DOW characteristics of the disk with the two different initialization methods.

  4. Computing algebraic transfer entropy and coupling directions via transcripts

    Science.gov (United States)

    Amigó, José M.; Monetti, Roberto; Graff, Beata; Graff, Grzegorz

    2016-11-01

    Most random processes studied in nonlinear time series analysis take values on sets endowed with a group structure, e.g., the real and rational numbers, and the integers. This fact allows to associate with each pair of group elements a third element, called their transcript, which is defined as the product of the second element in the pair times the first one. The transfer entropy of two such processes is called algebraic transfer entropy. It measures the information transferred between two coupled processes whose values belong to a group. In this paper, we show that, subject to one constraint, the algebraic transfer entropy matches the (in general, conditional) mutual information of certain transcripts with one variable less. This property has interesting practical applications, especially to the analysis of short time series. We also derive weak conditions for the 3-dimensional algebraic transfer entropy to yield the same coupling direction as the corresponding mutual information of transcripts. A related issue concerns the use of mutual information of transcripts to determine coupling directions in cases where the conditions just mentioned are not fulfilled. We checked the latter possibility in the lowest dimensional case with numerical simulations and cardiovascular data, and obtained positive results.

  5. Coherence resonance and stochastic resonance in directionally coupled rings

    Science.gov (United States)

    Werner, Johannes Peter; Benner, Hartmut; Florio, Brendan James; Stemler, Thomas

    2011-11-01

    In coupled systems, symmetry plays an important role for the collective dynamics. We investigate the dynamical response to noise with and without weak periodic modulation for two classes of ring systems. Each ring system consists of unidirectionally coupled bistable elements but in one class, the number of elements is even while in the other class the number is odd. Consequently, the rings without forcing show at a certain coupling strength, either ordering (similar to anti-ferromagnetic chains) or auto-oscillations. Analysing the bifurcations and fixed points of the two ring classes enables us to explain the dynamical response measured to noise and weak modulation. Moreover, by analysing a simplified model, we demonstrate that the response is universal for systems having a directional component in their stochastic dynamics in phase space around the origin.

  6. Robust independent modal space control of a coupled nano-positioning piezo-stage

    Science.gov (United States)

    Zhu, Wei; Yang, Fufeng; Rui, Xiaoting

    2018-06-01

    In order to accurately control a coupled 3-DOF nano-positioning piezo-stage, this paper designs a hybrid controller. In this controller, a hysteresis observer based on a Bouc-Wen model is established to compensate the hysteresis nonlinearity of the piezoelectric actuator first. Compared to hysteresis compensations using Preisach model and Prandt-Ishlinskii model, the compensation method using the hysteresis observer is computationally lighter. Then, based on the proposed dynamics model, by constructing the modal filter, a robust H∞ independent modal space controller is designed and utilized to decouple the piezo-stage and deal with the unmodeled dynamics, disturbance, and hysteresis compensation error. The effectiveness of the proposed controller is demonstrated experimentally. The experimental results show that the proposed controller can significantly achieve the high-precision positioning.

  7. Pd(II/HPMoV-Catalyzed Direct Oxidative Coupling Reaction of Benzenes with Olefins

    Directory of Open Access Journals (Sweden)

    Yasutaka Ishii

    2010-03-01

    Full Text Available The direct aerobic coupling reaction of arenes with olefins was successfully achieved by the use of Pd(OAc2/molybdovanadophosphoric acid (HPMoV as a key catalyst under 1 atm of dioxygen. This catalytic system could be extended to the coupling reaction of various substituted benzenes with olefins such as acrylates, aclrolein, and ethylene through the direct aromatic C-H bond activation.

  8. Direction of Coupling from Phases of Interacting Oscillators: A Permutation Information Approach

    Science.gov (United States)

    Bahraminasab, A.; Ghasemi, F.; Stefanovska, A.; McClintock, P. V. E.; Kantz, H.

    2008-02-01

    We introduce a directionality index for a time series based on a comparison of neighboring values. It can distinguish unidirectional from bidirectional coupling, as well as reveal and quantify asymmetry in bidirectional coupling. It is tested on a numerical model of coupled van der Pol oscillators, and applied to cardiorespiratory data from healthy subjects. There is no need for preprocessing and fine-tuning the parameters, which makes the method very simple, computationally fast and robust.

  9. The study on a gas-coupled two-stage stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Zhu, X. S.; Pan, C. Z.; Guo, J.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A two-stage gas-coupled Stirling-type pulse tube cryocooler (SPTC) driven by a linear dual-opposed compressor has been designed, manufactured and tested. Both of the stages adopted coaxial structure for compactness. The effect of a cold double-inlet at the second stage on the cooling performance was investigated. The test results show that the cold double-inlet will help to achieve a lower cooling temperature, but it is not conducive to achieving a higher cooling capacity. At present, without the cold double-inlet, the second stage has achieved a no-load temperature of 11.28 K and a cooling capacity of 620 mW/20 K with an input electric power of 450 W. With the cold double-inlet, the no-load temperature is lowered to 9.4 K, but the cooling capacity is reduced to 400 mW/20 K. The structure of the developed cryocooler and the influences of charge pressure, operating frequency and hot end temperature will also be introduced in this paper.

  10. Direct and Indirect Links between the Couple Relationship and Child School Outcomes

    Science.gov (United States)

    Chen, Hui-Hua; Liang, Yi-Ching; Gapp, Susan C.; Newland, Lisa A.; Giger, Jarod T.; Lin, Chunn-Ying

    2017-01-01

    This study measured aspects of the couple relationship to examine direct and indirect relations with parental involvement in education and children's school outcomes. The sample (n = 100) consisted of families that have at least one child between the ages of 8 and 11 in urban central Taiwan. Findings indicated that couple relationship quality is…

  11. Comparative Study on Uni- and Bi-Directional Fluid Structure Coupling of Wind Turbine Blades

    Directory of Open Access Journals (Sweden)

    Mesfin Belayneh Ageze

    2017-09-01

    Full Text Available The current trends of wind turbine blade designs are geared towards a longer and slender blade with high flexibility, exhibiting complex aeroelastic loadings and instability issues, including flutter; in this regard, fluid-structure interaction (FSI plays a significant role. The present article will conduct a comparative study between uni-directional and bi-directional fluid-structural coupling models for a horizontal axis wind turbine. A full-scale, geometric copy of the NREL 5MW blade with simplified material distribution is considered for simulation. Analytical formulations of the governing relations with appropriate approximation are highlighted, including turbulence model, i.e., Shear Stress Transport (SST k-ω. These analytical relations are implemented using Multiphysics package ANSYS employing Fluent module (Computational Fluid Dynamics (CFD-based solver for the fluid domain and Transient Structural module (Finite Element Analysis-based solver for the structural domain. ANSYS system coupling module also is configured to model the two fluid-structure coupling methods. The rated operational condition of the blade for a full cycle rotation is considered as a comparison domain. In the bi-directional coupling model, the structural deformation alters the angle of attack from the designed values, and by extension the flow pattern along the blade span; furthermore, the tip deflection keeps fluctuating whilst it tends to stabilize in the uni-directional coupling model.

  12. Experimental study of directionally solidified ferromagnetic shape memory alloy under multi-field coupling

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuping, E-mail: zhuyuping@126.com [Institute of Geophysics, China Earthquake Administration, Beijing 100081 (China); Chen, Tao; Teng, Yao [Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013 (China); Liu, Bingfei [Airport College, Civil Aviation University of China, Tianjin 300300 (China); Xue, Lijun [Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2016-11-01

    Directionally solidified, polycrystalline Ni–Mn–Ga is studied in this paper. The polycrystalline Ni–Mn–Ga samples were cut at different angles to solidification direction. The magnetic field induced strain under constant stress and the temperature-induced strain under constant magnetic field during the loading–unloading cycle were measured. The experimental results show that the mechanical behavior during the loading–unloading cycle of the material is nonlinear and anisotropic. Based on the experimental results, the effects of multi-field coupling factors, such as stress, magnetic field, temperature and cutting angle on the mechanical behaviors were analyzed. Some useful conclusions were obtained, which will provide guidance for practical applications. - Highlights: • The magnetic-induced strains in different directions are tested. • The temperature-induced strains in different directions are tested. • The effects of coupling factors on directional solidification samples are studied.

  13. A Single-Stage High-Power-Factor Light-Emitting Diode (LED Driver with Coupled Inductors for Streetlight Applications

    Directory of Open Access Journals (Sweden)

    Chun-An Cheng

    2017-02-01

    Full Text Available This paper presents and implements a single-stage high-power-factor light-emitting diode (LED driver with coupled inductors, suitable for streetlight applications. The presented LED driver integrates an interleaved buck-boost power factor correction (PFC converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power conversion circuit. Coupled inductors inside the interleaved buck-boost PFC converter sub-circuit are designed to operate in discontinuous conduction mode (DCM for achieving input-current shaping, and the half-bridge-type series resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the presented driver features a high power factor, low total harmonic distortion (THD of input current, and soft switching. Finally, a prototype driver is developed and implemented to supply a 165-W-rated LED streetlight module with utility-line input voltages ranging from 210 to 230 V. Experimental results demonstrate that high power factor (>0.99, low utility-line current THD (<7%, low-output voltage ripples (<1%, low-output current ripples (<10%, and high circuit efficiency (>90% are obtained in the presented single-stage driver for LED streetlight applications.

  14. The establishment and application of direct coupled electrostatic-structural field model in electrostatically controlled deployable membrane antenna

    Science.gov (United States)

    Gu, Yongzhen; Duan, Baoyan; Du, Jingli

    2018-05-01

    The electrostatically controlled deployable membrane antenna (ECDMA) is a promising space structure due to its low weight, large aperture and high precision characteristics. However, it is an extreme challenge to describe the coupled field between electrostatic and membrane structure accurately. A direct coupled method is applied to solve the coupled problem in this paper. Firstly, the membrane structure and electrostatic field are uniformly described by energy, considering the coupled problem is an energy conservation phenomenon. Then the direct coupled electrostatic-structural field governing equilibrium equations are obtained by energy variation approach. Numerical results show that the direct coupled method improves the computing efficiency by 36% compared with the traditional indirect coupled method with the same level accuracy. Finally, the prototype has been manufactured and tested and the ECDMA finite element simulations show good agreement with the experiment results as the maximum surface error difference is 6%.

  15. Asynchronous machines. Direct torque control; Machines asynchrones. Commande par controle direct de couple

    Energy Technology Data Exchange (ETDEWEB)

    Fornel, B. de [Institut National Polytechnique, 31 - Toulouse (France)

    2006-05-15

    The asynchronous machine, with its low cost and robustness, is today the most widely used motor to make speed variators. However, its main drawback is that the same current generates both the magnetic flux and the torque, and thus any torque variation creates a flux variation. Such a coupling gives to the asynchronous machine a nonlinear behaviour which makes its control much more complex. The direct self control (DSC) method has been developed to improve the low efficiency of the scalar control method and for the specific railway drive application. The direct torque control (DTC) method is derived from the DSC method but corresponds to other type of applications. The DSC and DTC algorithms for asynchronous motors are presented in this article: 1 - direct control of the stator flux (DSC): principle, flux control, torque control, switching frequency of the inverter, speed estimation; 2 - direct torque control (DTC): principle, electromagnetic torque derivative, signals shape and switching frequency, some results, DTC speed variator without speed sensor, DTC application to multi-machine multi-converter systems; 3 - conclusion. (J.S.)

  16. Coupling of the four design stages in the management of nuclear fuel

    International Nuclear Information System (INIS)

    Marinez R, R. L.

    2016-01-01

    In this work, the main characteristics of the system to solve the four stages of the nuclear fuel management are presented; the above for boiling water reactors (BWR). The novelty of the system is that a complete solution is obtained in a coupled way; the involved stages are fuel lattice design, fuel assembly design, fuel reload design and control rod pattern design. To do this, in each stage of the process some heuristics techniques are applied, and each stage has its own objective function. The used heuristic techniques are neural network and a hybrid between scatter search and path re linking for fuel lattice design; for fuel assembly design a simple local search was applied and finally, for both fuel reload and control rod pattern designs, the tabu search technique was used. The system have two loops, one external loop and one internal loop, the first one starts with fuel lattice design and concludes with control rod pattern design; on the other hand, the internal loop executes an iterative process between both fuel reload design and control rod pattern designs, to start this loop a seed fuel reload is required, which is obtained applying Haling principle. The internal loop is finished when four iterations were achieved, while the external loop is finished when two iterations were achieved, this number of iterations was fixed due to the great quantity of required computational resources. An 18- months equilibrium cycle was considered to have a reference value to compare against the obtained results with our system, this cycle have two fuel fresh batches with the same average uranium enrichment, but different gadolinia content. The above cycle achieved a 10,896 Mwd/Tu of energy and was divided into 12 burnup steps. The obtained results show the advantage to solve the complete problem in a coupled way, even though a great quantity of computational resources are used. It is necessary to note that the energy value was not achieved in all cases, only in some

  17. Boosting the Direct CP Measurement of the Higgs-Top Coupling.

    Science.gov (United States)

    Buckley, Matthew R; Gonçalves, Dorival

    2016-03-04

    Characterizing the 125 GeV Higgs boson is a critical component of the physics program at the LHC Run II. In this Letter, we consider tt[over ¯]H associated production in the dileptonic mode. We demonstrate that the difference in azimuthal angle between the leptons from top decays can directly reveal the CP structure of the top-Higgs coupling with the sensitivity of the measurement substantially enhanced in the boosted Higgs regime. We first show how to access this channel via H→bb[over ¯] jet-substructure tagging, then demonstrate the ability of the new variable to measure CP. Our analysis includes all signal and background samples simulated via the MC@NLO algorithm including hadronization and underlying-event effects. Using a boosted Higgs substructure with dileptonic tops, we find that the top-Higgs coupling strength and the CP structure can be directly probed with achievable luminosity at the 13 TeV LHC.

  18. FIRST DIRECT EVIDENCE OF TWO STAGES IN FREE RECALL

    Directory of Open Access Journals (Sweden)

    Eugen Tarnow

    2015-12-01

    Full Text Available I find that exactly two stages can be seen directly in sequential free recall distributions. These distributions show that the first three recalls come from the emptying of working memory, recalls 6 and above come from a second stage and the 4th and 5th recalls are mixtures of the two.A discontinuity, a rounded step function, is shown to exist in the fitted linear slope of the recall distributions as the recall shifts from the emptying of working memory (positive slope to the second stage (negative slope. The discontinuity leads to a first estimate of the capacity of working memory at 4-4.5 items. The total recall is shown to be a linear combination of the content of working memory and items recalled in the second stage with 3.0-3.9 items coming from working memory, a second estimate of the capacity of working memory. A third, separate upper limit on the capacity of working memory is found (3.06 items, corresponding to the requirement that the content of working memory cannot exceed the total recall, item by item. This third limit is presumably the best limit on the average capacity of unchunked working memory.The second stage of recall is shown to be reactivation: The average times to retrieve additional items in free recall obey a linear relationship as a function of the recall probability which mimics recognition and cued recall, both mechanisms using reactivation (Tarnow, 2008.

  19. MgB2 magnetometer with directly coupled pick-up loop

    NARCIS (Netherlands)

    Portesi, C.; Mijatovic, D.; Veldhuis, Dick; Brinkman, Alexander; Monticone, E.; Gonnelli, R.S.

    2006-01-01

    magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which

  20. Directional interacting whispering-gallery modes in coupled dielectric microdisks

    International Nuclear Information System (INIS)

    Ryu, Jung-Wan; Lee, Soo-Young; Kim, Chil-Min; Park, Young-Jai

    2006-01-01

    We study the optical interaction in a coupled dielectric microdisks by investigating the splitting of resonance positions of interacting whispering-gallery modes (WGM's) and their pattern change, depending on the distance between the microdisks. It is shown that the interaction between the WGM's with odd parity about the y axis becomes appreciable at a distance less than a wavelength and causes directional emissions of the resulting interacting WGM's. The directionality of the interacting WGM's can be understood in terms of an effective boundary deformation in ray dynamical analysis. We also discuss the oscillation of the splitting when the distance is greater than a wavelength

  1. Methyl Radicals in Oxidative Coupling of Methane Directly Confirmed by Synchrotron VUV Photoionization Mass Spectroscopy

    Science.gov (United States)

    Luo, Liangfeng; Tang, Xiaofeng; Wang, Wendong; Wang, Yu; Sun, Shaobo; Qi, Fei; Huang, Weixin

    2013-01-01

    Gas-phase methyl radicals have been long proposed as the key intermediate in catalytic oxidative coupling of methane, but the direct experimental evidence still lacks. Here, employing synchrotron VUV photoionization mass spectroscopy, we have directly observed the formation of gas-phase methyl radicals during oxidative coupling of methane catalyzed by Li/MgO catalysts. The concentration of gas-phase methyl radicals correlates well with the yield of ethylene and ethane products. These results lead to an enhanced fundamental understanding of oxidative coupling of methane that will facilitate the exploration of new catalysts with improved performance. PMID:23567985

  2. Direct 13C-1H coupling constants in the vinyl group of 1-vinylpyrazoles

    International Nuclear Information System (INIS)

    Afonin, A.V.; Voronov, V.K.; Es'kova, L.A.; Domnina, E.S.; Petrova, E.V.; Zasyad'ko, O.V.

    1987-01-01

    In a continuation of a study of the rotational isomerism of 1-vinylpyrazoles, they studied the direct 13 C- 1 H coupling constants in the vinyl group of 1-vinylpyrazole, 1-vinyl-4-bromopyrazole, 1-vinyl-3-methylpyrazole, 1-vinyl-5-methylpyrazole, 1-vinyl-3,5-dimethylpyrazole, and 1-vinyl-4-nitro-3,5-dimethylpyrazole. The 13 C- 1 H direct coupling constants in the vinyl group of 1-vinylpyrazoles are stereo-specific and vary with change in the conformer ratio

  3. Robust Adaptive Synchronization of Ring Configured Uncertain Chaotic FitzHugh–Nagumo Neurons under Direction-Dependent Coupling

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2018-02-01

    Full Text Available This paper exploits the dynamical modeling, behavior analysis, and synchronization of a network of four different FitzHugh–Nagumo (FHN neurons with unknown parameters linked in a ring configuration under direction-dependent coupling. The main purpose is to investigate a robust adaptive control law for the synchronization of uncertain and perturbed neurons, communicating in a medium of bidirectional coupling. The neurons are assumed to be different and interconnected in a ring structure. The strength of the gap junctions is taken to be different for each link in the network, owing to the inter-neuronal coupling medium properties. Robust adaptive control mechanism based on Lyapunov stability analysis is employed and theoretical criteria are derived to realize the synchronization of the network of four FHN neurons in a ring form with unknown parameters under direction-dependent coupling and disturbances. The proposed scheme for synchronization of dissimilar neurons, under external electrical stimuli, coupled in a ring communication topology, having all parameters unknown, and subject to directional coupling medium and perturbations, is addressed for the first time as per our knowledge. To demonstrate the efficacy of the proposed strategy, simulation results are provided.

  4. Robust Adaptive Synchronization of Ring Configured Uncertain Chaotic FitzHugh–Nagumo Neurons under Direction-Dependent Coupling

    Science.gov (United States)

    Iqbal, Muhammad; Rehan, Muhammad; Hong, Keum-Shik

    2018-01-01

    This paper exploits the dynamical modeling, behavior analysis, and synchronization of a network of four different FitzHugh–Nagumo (FHN) neurons with unknown parameters linked in a ring configuration under direction-dependent coupling. The main purpose is to investigate a robust adaptive control law for the synchronization of uncertain and perturbed neurons, communicating in a medium of bidirectional coupling. The neurons are assumed to be different and interconnected in a ring structure. The strength of the gap junctions is taken to be different for each link in the network, owing to the inter-neuronal coupling medium properties. Robust adaptive control mechanism based on Lyapunov stability analysis is employed and theoretical criteria are derived to realize the synchronization of the network of four FHN neurons in a ring form with unknown parameters under direction-dependent coupling and disturbances. The proposed scheme for synchronization of dissimilar neurons, under external electrical stimuli, coupled in a ring communication topology, having all parameters unknown, and subject to directional coupling medium and perturbations, is addressed for the first time as per our knowledge. To demonstrate the efficacy of the proposed strategy, simulation results are provided. PMID:29535622

  5. Direct Formation of Silane Coupling Agents on Glass for Improved Composite Performance

    National Research Council Canada - National Science Library

    Boyles, David

    2003-01-01

    ...; and 3) reaction of aminoalkenes with the reduced surface via a hydrosilylation reaction which formed the coupling agent directly on the surface of the glass fiber for glass surfaces incorporated into epoxy systems...

  6. Performance Characterization of an xy-Stage Applied to Micrometric Laser Direct Writing Lithography

    Directory of Open Access Journals (Sweden)

    Juan Jaramillo

    2017-01-01

    Full Text Available This article concerns the characterization of the stability and performance of a motorized stage used in laser direct writing lithography. The system was built from commercial components and commanded by G-code. Measurements use a pseudo-periodic-pattern (PPP observed by a camera and image processing is based on Fourier transform and phase measurement methods. The results report that the built system has a stability against vibrations determined by peak-valley deviations of 65 nm and 26 nm in the x and y directions, respectively, with a standard deviation of 10 nm in both directions. When the xy-stage is in movement, it works with a resolution of 0.36 μm, which is an acceptable value for most of research and development (R and D microtechnology developments in which the typical feature size used is in the micrometer range.

  7. Performance Characterization of an xy-Stage Applied to Micrometric Laser Direct Writing Lithography.

    Science.gov (United States)

    Jaramillo, Juan; Zarzycki, Artur; Galeano, July; Sandoz, Patrick

    2017-01-31

    This article concerns the characterization of the stability and performance of a motorized stage used in laser direct writing lithography. The system was built from commercial components and commanded by G-code. Measurements use a pseudo-periodic-pattern (PPP) observed by a camera and image processing is based on Fourier transform and phase measurement methods. The results report that the built system has a stability against vibrations determined by peak-valley deviations of 65 nm and 26 nm in the x and y directions, respectively, with a standard deviation of 10 nm in both directions. When the xy-stage is in movement, it works with a resolution of 0.36 μm, which is an acceptable value for most of research and development (R and D) microtechnology developments in which the typical feature size used is in the micrometer range.

  8. Method and system for dual resolution translation stage

    Science.gov (United States)

    Halpin, John Michael

    2014-04-22

    A dual resolution translation stage includes a stage assembly operable to receive an optical element and a low resolution adjustment device mechanically coupled to the stage assembly. The dual resolution stage also includes an adjustable pivot block mechanically coupled to the stage assembly. The adjustable pivot block includes a pivot shaft. The dual resolution stage further includes a lever arm mechanically coupled to the adjustable pivot block. The lever arm is operable to pivot about the pivot shaft. The dual resolution stage additionally includes a high resolution adjustment device mechanically coupled to the lever arm and the stage assembly.

  9. Theoretical and experimental investigations on the cooling capacity distributions at the stages in the thermally-coupled two-stage Stirling-type pulse tube cryocooler without external precooling

    Science.gov (United States)

    Tan, Jun; Dang, Haizheng

    2017-03-01

    The two-stage Stirling-type pulse tube cryocooler (SPTC) has advantages in simultaneously providing the cooling powers at two different temperatures, and the capacity in distributing these cooling capacities between the stages is significant to its practical applications. In this paper, a theoretical model of the thermally-coupled two-stage SPTC without external precooling is established based on the electric circuit analogy with considering real gas effects, and the simulations of both the cooling performances and PV power distribution between stages are conducted. The results indicate that the PV power is inversely proportional to the acoustic impedance of each stage, and the cooling capacity distribution is determined by the cold finger cooling efficiency and the PV power into each stage together. The design methods of the cold fingers to achieve both the desired PV power and the cooling capacity distribution between the stages are summarized. The two-stage SPTC is developed and tested based on the above theoretical investigations, and the experimental results show that it can simultaneously achieve 0.69 W at 30 K and 3.1 W at 85 K with an electric input power of 330 W and a reject temperature of 300 K. The consistency between the simulated and the experimental results is observed and the theoretical investigations are experimentally verified.

  10. Pinning synchronization of hybrid-coupled directed delayed dynamical network via intermittent control.

    Science.gov (United States)

    Cai, Shuiming; Zhou, Peipei; Liu, Zengrong

    2014-09-01

    This paper concerns the problem of exponential synchronization for a class of general delayed dynamical networks with hybrid coupling via pinning periodically intermittent control. Both the internal delay and coupling delay are taken into account in the network model. Meanwhile, the transmission delay and self-feedback delay are involved in the delayed coupling term. By establishing a new differential inequality, several simple and useful exponential synchronization criteria are derived analytically. It is shown that the controlled synchronization state can vary in comparison with the conventional synchronized solution, and the degree of the node and the inner delayed coupling matrix play important roles in the controlled synchronization state. By choosing different inner delayed coupling matrices and the degrees of the node, different controlled synchronization states can be obtained. Furthermore, the detail pinning schemes deciding what nodes should be chosen as pinned candidates and how many nodes are needed to be pinned for a fixed coupling strength are provided. The simple procedures illuminating how to design suitable intermittent controllers in real application are also given. Numerical simulations, including an undirected scale-free network and a directed small-world network, are finally presented to demonstrate the effectiveness of the theoretical results.

  11. A stage is a stage is a stage: a direct comparison of two scoring systems.

    Science.gov (United States)

    Dawson, Theo L

    2003-09-01

    L. Kohlberg (1969) argued that his moral stages captured a developmental sequence specific to the moral domain. To explore that contention, the author compared stage assignments obtained with the Standard Issue Scoring System (A. Colby & L. Kohlberg, 1987a, 1987b) and those obtained with a generalized content-independent stage-scoring system called the Hierarchical Complexity Scoring System (T. L. Dawson, 2002a), on 637 moral judgment interviews (participants' ages ranged from 5 to 86 years). The correlation between stage scores produced with the 2 systems was .88. Although standard issue scoring and hierarchical complexity scoring often awarded different scores up to Kohlberg's Moral Stage 2/3, from his Moral Stage 3 onward, scores awarded with the two systems predominantly agreed. The author explores the implications for developmental research.

  12. Preparation of fluorinated biaryls through direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates

    KAUST Repository

    Fang, Xin; Huang, Yuanyuan; Chen, Xiaoqing; Lin, Xiaoxi; Bai, Zhengshuai; Huang, Kuo-Wei; Yuan, Yaofeng; Weng, Zhiqiang

    2013-01-01

    The direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates gave the desired products of fluorinated biaryls in good to excellent yields. A diverse set of important functional groups including methoxy, aldehyde, ester

  13. Ni-Catalyzed Dehydrogenative Cross-Coupling: Direct Transformation of Aldehydes to Esters and Amides

    Science.gov (United States)

    Whittaker, Aaron M.; Dong, Vy M.

    2015-01-01

    By exploring a new mode of Ni-catalyzed cross-coupling, we have developed a protocol to transform both aromatic and aliphatic aldehydes into either esters or amides directly. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. We present mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C–H bond. PMID:25424967

  14. The detection of transient directional couplings based on phase synchronization

    International Nuclear Information System (INIS)

    Wagner, T; Fell, J; Lehnertz, K

    2010-01-01

    We extend recent approaches based on the concept of phase synchronization to enable the time-resolved investigation of directional relationships between coupled dynamical systems from short and transient noisy time series. For our approach, we consider an observed ensemble of a sufficiently large number of time series as multiple realizations of a process. We derive an index that quantifies the direction of transient interactions and assess its statistical significance using surrogate techniques. Analysing time series from noisy and chaotic systems, we demonstrate numerically the applicability and limitations of our approach. Our findings from an exemplary application to event-related brain activities underline the importance of our method for improving knowledge about the mechanisms underlying memory formation in humans.

  15. The detection of transient directional couplings based on phase synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, T; Fell, J; Lehnertz, K, E-mail: twagner@uni-bonn.d [Department of Epileptology, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany)

    2010-05-15

    We extend recent approaches based on the concept of phase synchronization to enable the time-resolved investigation of directional relationships between coupled dynamical systems from short and transient noisy time series. For our approach, we consider an observed ensemble of a sufficiently large number of time series as multiple realizations of a process. We derive an index that quantifies the direction of transient interactions and assess its statistical significance using surrogate techniques. Analysing time series from noisy and chaotic systems, we demonstrate numerically the applicability and limitations of our approach. Our findings from an exemplary application to event-related brain activities underline the importance of our method for improving knowledge about the mechanisms underlying memory formation in humans.

  16. Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry by direct injection nebulization for selenium speciation

    DEFF Research Database (Denmark)

    Bendahl, Lars; Gammelgaard, Bente; Jons, O.

    2001-01-01

    A demountable direct injection high efficiency nebulizer operating at low sample uptake rates was developed and used for coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS). When the nebulizer was used for continuous sample introduction, detection...

  17. A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2017-04-01

    Full Text Available This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope’s modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity.

  18. Experimental analysis of direct-expansion ground-coupled heat pump systems

    Science.gov (United States)

    Mei, V. C.; Baxter, V. D.

    1991-09-01

    Direct-expansion ground-coil-coupled (DXGC) heat pump systems have certain energy efficiency advantages over conventional ground-coupled heat pump (GCHP) systems. Principal among these advantages are that the secondary heat transfer fluid heat exchanger and circulating pump are eliminated. While the DXGC concept can produce higher efficiencies, it also produces more system design and environmental problems (e.g., compressor starting, oil return, possible ground pollution, and more refrigerant charging). Furthermore, general design guidelines for DXGC systems are not well documented. A two-pronged approach was adopted for this study: (1) a literature survey, and (2) a laboratory study of a DXGC heat pump system with R-22 as the refrigerant, for both heating and cooling mode tests done in parallel and series tube connections. The results of each task are described in this paper. A set of general design guidelines was derived from the test results and is also presented.

  19. Ultrafast directional beam switching in coupled vertical-cavity surface-emitting lasers

    International Nuclear Information System (INIS)

    Ning, C. Z.; Goorjian, P.

    2001-01-01

    We propose a strategy to performing ultrafast directional beam switching using two coupled vertical-cavity surface-emitting lasers (VCSELs). The proposed strategy is demonstrated for two VCSELs of 5.6 μm in diameter placed about 1 μm apart from the edges, showing a switching speed of 42 GHz with a maximum far-field angle span of about 10 degree. [copyright] 2001 American Institute of Physics

  20. Sleep-dependent directional coupling between human neocortex and hippocampus.

    Science.gov (United States)

    Wagner, Tobias; Axmacher, Nikolai; Lehnertz, Klaus; Elger, Christian E; Fell, Jürgen

    2010-02-01

    Complex interactions between neocortex and hippocampus are the neural basis of memory formation. Two-step theories of memory formation suggest that initial encoding of novel information depends on the induction of rapid plasticity within the hippocampus, and is followed by a second sleep-dependent step of memory consolidation. These theories predict information flow from the neocortex into the hippocampus during waking state and in the reverse direction during sleep. However, experimental evidence that interactions between hippocampus and neocortex have a predominant direction which reverses during sleep rely on cross-correlation analysis of data from animal experiments and yielded inconsistent results. Here, we investigated directional coupling in intracranial EEG data from human subjects using a phase-modeling approach which is well suited to reveal functional interdependencies in oscillatory data. In general, we observed that the anterior hippocampus predominantly drives nearby and remote brain regions. Surprisingly, however, the influence of neocortical regions on the hippocampus significantly increased during sleep as compared to waking state. These results question the standard model of hippocampal-neocortical interactions and suggest that sleep-dependent consolidation is accomplished by an active retrieval of hippocampal information by the neocortex. Copyright 2009 Elsevier Srl. All rights reserved.

  1. Physics Implications of Flat Directions in Free Fermionic Superstring Models; 1, Mass Spectrum and Couplings

    CERN Document Server

    Cleaver, G; Espinosa, J R; Everett, L; Langacker, P G; Wang, J

    1999-01-01

    From the "top-down" approach we investigate physics implications of the class of D- and F- flat directions formed from non-Abelian singlets which are proven flat to all orders in the nonrenormalizable superpotential, for a prototype quasi-realistic free fermionic string model with the standard model gauge group and three families (CHL5). These flat directions have at least an additional U(1)' unbroken at the string scale. For each flat direction, the complete set of effective mass terms and effective trilinear superpotential terms in the observable sector are computed to all orders in the VEV's of the fields in the flat direction. The "string selection-rules" disallow a large number of couplings allowed by gauge invariance, resulting in a massless spectrum with a large number of exotics, in most cases excluded by experiment, thus signifying a generic flaw of these models. Nevertheless, the resulting trilinear couplings of the massless spectrum possess a number of interesting features which we analyse for two ...

  2. Directed coupling in local field potentials of macaque V4 during visual short-term memory revealed by multivariate autoregressive models

    Directory of Open Access Journals (Sweden)

    Gregor M Hoerzer

    2010-05-01

    Full Text Available Processing and storage of sensory information is based on the interaction between different neural populations rather than the isolated activity of single neurons. In order to characterize the dynamic interaction and transient cooperation of sub-circuits within a neural network, multivariate autoregressive (MVAR models have proven to be an important analysis tool. In this study, we apply directed functional coupling based on MVAR models and describe the temporal and spatial changes of functional coupling between simultaneously recorded local field potentials (LFP in extrastriate area V4 during visual memory. Specifically, we compare the strength and directional relations of coupling based on Generalized Partial Directed Coherence (GDPC measures while two rhesus monkeys perform a visual short-term memory task. In both monkeys we find increases in theta power during the memory period that are accompanied by changes in directed coupling. These interactions are most prominent in the low frequency range encompassing the theta band (3-12~Hz and, more importantly, are asymmetric between pairs of recording sites. Furthermore, we find that the degree of interaction decreases as a function of distance between electrode positions, suggesting that these interactions are a predominantly local phenomenon. Taken together, our results show that directed coupling measures based on MVAR models are able to provide important insights into the spatial and temporal formation of local functionally coupled ensembles during visual memory in V4. Moreover, our findings suggest that visual memory is accompanied not only by a temporary increase of oscillatory activity in the theta band, but by a direction-dependent change in theta coupling, which ultimately represents a change in functional connectivity within the neural circuit.

  3. Directional gene expression and antisense transcripts in sexual and asexual stages of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    López-Barragán María J

    2011-11-01

    Full Text Available Abstract Background It has been shown that nearly a quarter of the initial predicted gene models in the Plasmodium falciparum genome contain errors. Although there have been efforts to obtain complete cDNA sequences to correct the errors, the coverage of cDNA sequences on the predicted genes is still incomplete, and many gene models for those expressed in sexual or mosquito stages have not been validated. Antisense transcripts have widely been reported in P. falciparum; however, the extent and pattern of antisense transcripts in different developmental stages remain largely unknown. Results We have sequenced seven bidirectional libraries from ring, early and late trophozoite, schizont, gametocyte II, gametocyte V, and ookinete, and four strand-specific libraries from late trophozoite, schizont, gametocyte II, and gametocyte V of the 3D7 parasites. Alignment of the cDNA sequences to the 3D7 reference genome revealed stage-specific antisense transcripts and novel intron-exon splicing junctions. Sequencing of strand-specific cDNA libraries suggested that more genes are expressed in one direction in gametocyte than in schizont. Alternatively spliced genes, antisense transcripts, and stage-specific expressed genes were also characterized. Conclusions It is necessary to continue to sequence cDNA from different developmental stages, particularly those of non-erythrocytic stages. The presence of antisense transcripts in some gametocyte and ookinete genes suggests that these antisense RNA may play an important role in gene expression regulation and parasite development. Future gene expression studies should make use of directional cDNA libraries. Antisense transcripts may partly explain the observed discrepancy between levels of mRNA and protein expression.

  4. A New Cost-Effective Multi-Drive Solution based on a Two-Stage Direct Power Electronic Conversion Topology

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    of a protection circuit involving twelve diodes with full voltage/current ratings used only during faulty situations, makes this topology not so attractive. Lately, two stage Direct Power Electronic Conversion (DPEC) topologies have been proposed, providing similar functionality as a matrix converter but allowing...... shared by many loads, making this topology more cost effective. The functionality of the proposed two-stage multi-drive direct power electronic conversion topology is validated by experiments on a realistic laboratory prototype....

  5. tBuLi-Mediated One-Pot Direct Highly Selective Cross-Coupling of Two Distinct Aryl Bromides

    NARCIS (Netherlands)

    Vila, Carlos; Cembellin, Sara; Hornillos, Valentin; Giannerini, Massimo; Fananas-Mastral, Martin; Feringa, Ben L.

    2015-01-01

    A Pd-catalyzed direct cross-coupling of two distinct aryl bromides mediated by tBuLi is described. The use of [Pd-PEPPSI-IPr] or [Pd-PEPPSI-IPent] as catalyst allows for the efficient one-pot synthesis of unsymmetrical biaryls at room temperature. The key for this selective cross-coupling is the use

  6. Blood Stage Plasmodium falciparum Exhibits Biological Responses to Direct Current Electric Fields.

    Directory of Open Access Journals (Sweden)

    Lorena M Coronado

    Full Text Available The development of resistance to insecticides by the vector of malaria and the increasingly faster appearance of resistance to antimalarial drugs by the parasite can dangerously hamper efforts to control and eradicate the disease. Alternative ways to treat this disease are urgently needed. Here we evaluate the in vitro effect of direct current (DC capacitive coupling electrical stimulation on the biology and viability of Plasmodium falciparum. We designed a system that exposes infected erythrocytes to different capacitively coupled electric fields in order to evaluate their effect on P. falciparum. The effect on growth of the parasite, replication of DNA, mitochondrial membrane potential and level of reactive oxygen species after exposure to electric fields demonstrate that the parasite is biologically able to respond to stimuli from DC electric fields involving calcium signaling pathways.

  7. Shear Alfven wave excitation by direct antenna coupling and fast wave resonant mode conversion

    International Nuclear Information System (INIS)

    Borg, G.G.

    1994-01-01

    Antenna coupling to the shear Alfven wave by both direct excitation and fast wave resonant mode conversion is modelled analytically for a plasma with a one dimensional linear density gradient. We demonstrate the existence of a shear Alfven mode excited directly by the antenna. For localised antennas, this mode propagates as a guided beam along the steady magnetic field lines intersecting the antenna. Shear Alfven wave excitation by resonant mode conversion of a fast wave near the Alfven resonance layer is also demonstrated and we prove that energy is conserved in this process. We compare the efficiency of these two mechanisms of shear Alfven wave excitation and present a simple analytical formula giving the ratio of the coupled powers. Finally, we discuss the interpretation of some experimental results. 45 refs., 7 figs

  8. Developmental Issues in Counseling With Couples.

    Science.gov (United States)

    Seligman, Linda; Deutsch, Marjorie B.

    Marriages, just like the individuals in them, go through stages of development. Understanding these relatively predictable stages can be helpful to couples, by allaying apprehension, promoting preparation for change, and putting fluctuations into perspective. Research on marital stages and experiences in counseling couples suggest that marriages…

  9. /sup 13/C-/sup 13/C spin-spin coupling constants in structural investigations. V. The direct carbon-carbon coupling constants in the vinyl group

    Energy Technology Data Exchange (ETDEWEB)

    Krivdin, L.B.; Shcherbakov, V.V.; Kalabin, G.A.

    1988-03-10

    The direct spin-spin coupling constants in the vinyl group were measured in 100 mono-substituted ethylene derivatives. The inductive effect of the substituent was found to be the major factor in the variation of this constant and, in some cases, the stereospecific effect of the unshared electron pairs of heteratoms makes a significant contribution to the /sup 13/C-/sup 13/C coupling constants.

  10. Effect of coupling asymmetry on mean-field solutions of the direct and inverse Sherrington-Kirkpatrick model

    DEFF Research Database (Denmark)

    Sakellariou, Jason; Roudi, Yasser; Mezard, Marc

    2012-01-01

    We study how the degree of symmetry in the couplings influences the performance of three mean field methods used for solving the direct and inverse problems for generalized Sherrington-Kirkpatrick models. In this context, the direct problem is predicting the potentially time-varying magnetizations...... than the other two approximations, TAP outperforms MF when the coupling matrix is nearly symmetric, while MF works better when it is strongly asymmetric. For the inverse problem, MF performs better than both TAP and nMF, although an ad hoc adjustment of TAP can make it comparable to MF. For high...

  11. Numerical study of unsteady flows past oscillating airfoils using direct zonal coupling method

    International Nuclear Information System (INIS)

    Zhang, F.; Khalid, M.

    2005-01-01

    A direct zonal coupling method was proposed for solving the flows past oscillating airfoils in this study. The entire computational domain was divided into inner and outer zones. The grid in the inner zone is moving with the oscillation of the airfoil, whereas the grid in the outer zone is artificially adjusted to the position consistent with the inner zone grid. The governing equations in the moving frame (the rotation potential energy is included) and those under the stationary frame were applied to inner and outer zones, respectively. By using this kind of treatment, the grid on the zonal interface is 1-to-1 matched. The coupling between the two zones is direct. Both the geometric and flow conservations are entirely satisfied. The NACA0012 and NLR7301 airfoils with oscillations were used as the test cases. The accuracy of the proposed method was demonstrated by the computational results compared with the experimental data.(author)

  12. Renewable water: Direct contact membrane distillation coupled with solar ponds

    International Nuclear Information System (INIS)

    Suárez, Francisco; Ruskowitz, Jeffrey A.; Tyler, Scott W.; Childress, Amy E.

    2015-01-01

    Highlights: • Experimental investigation of direct contact membrane distillation driven by solar ponds. • The DCMD/SGSP system treats ∼6 times the water flow treated by an AGMD/SGSP system. • Half of the energy extracted from the SGSP was used to transport water across the membrane. • Reducing heat losses through the DCMD/SGSP system would yield higher water fluxes. - Abstract: Desalination powered by renewable energy sources is an attractive solution to address the worldwide water-shortage problem without contributing significant to greenhouse gas emissions. A promising system for renewable energy desalination is the utilization of low-temperature direct contact membrane distillation (DCMD) driven by a thermal solar energy system, such as a salt-gradient solar pond (SGSP). This investigation presents the first experimental study of fresh water production in a coupled DCMD/SGSP system. The objectives of this work are to determine the experimental fresh water production rates and the energetic requirements of the different components of the system. From the laboratory results, it was found that the coupled DCMD/SGSP system treats approximately six times the water flow treated by a similar system that consisted of an air–gap membrane distillation unit driven by an SGSP. In terms of the energetic requirements, approximately 70% of the heat extracted from the SGSP was utilized to drive thermal desalination and the rest was lost in different locations of the system. In the membrane module, only half of the useful heat was actually used to transport water across the membrane and the remainder was lost by conduction in the membrane. It was also found that by reducing heat losses throughout the system would yield higher water fluxes, pointing out the need to improve the efficiency throughout the DCMD/SGSP coupled system. Therefore, further investigation of membrane properties, insulation of the system, or optimal design of the solar pond must be addressed in

  13. Tailor-made nano-structured materials for perpendicular recording media and head-precise control of direct/indirect exchange coupling

    International Nuclear Information System (INIS)

    Takahashi, Migaku; Tsunoda, Masakiyo; Saito, Shin

    2009-01-01

    Tailor-made nano-structured spin materials obtained by precisely controlled nano-scale fabrication technologies for use in ultra-high density hard disk drives (HDDs), as well as an understanding of their nanomagnetics, are essential from the view point of materials, processes, and physics. Artificial control of the exchange coupling among ferromagnetic layers through the RKKY interaction (indirect) and direct exchange coupling represented as the exchange bias at the ferromagnetic (FM)/antiferromagnetic (AFM) interface are of great interest and have received significant attention to induce new modulated spin structures in conventional simple FM materials. In particular, soft magnetic under layer (SUL) with strong synthetic antiferromagnetic (SAF) coupling between two adjacent soft magnetic layers, exchange coupled stacked media introducing exchange coupling between FM layers and giant exchange anisotropy at the FM/AFM interface have attracted significant attention from the view point of applications. Within the framework of the present paper, we discuss future technical trends for SUL, granular media and the spin-valve head from the viewpoint of direct and/or indirect exchange coupling based on our recent results

  14. Electric power generating plant having direct-coupled steam and compressed-air cycles

    Science.gov (United States)

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  15. Electric power generating plant having direct coupled steam and compressed air cycles

    Science.gov (United States)

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  16. Modification of Irrational Ideas and Test Anxiety through Rational Stage Directed Hypnotherapy (RSDH).

    Science.gov (United States)

    Boutin, Gerard E.; Tosi, Donald J.

    1983-01-01

    Examined the effects of four treatment conditions on the modification of irrational ideas and test anxiety in female nursing students (N=48). The Rational Stage Directed Hypnotherapy (RSDH) treatment group was significantly more effective than the hypnosis only group. The placebo and control groups showed no significant effects. (Author/JAC)

  17. Transfer Entropy Estimation and Directional Coupling Change Detection in Biomedical Time Series

    Directory of Open Access Journals (Sweden)

    Lee Joon

    2012-04-01

    Full Text Available Abstract Background The detection of change in magnitude of directional coupling between two non-linear time series is a common subject of interest in the biomedical domain, including studies involving the respiratory chemoreflex system. Although transfer entropy is a useful tool in this avenue, no study to date has investigated how different transfer entropy estimation methods perform in typical biomedical applications featuring small sample size and presence of outliers. Methods With respect to detection of increased coupling strength, we compared three transfer entropy estimation techniques using both simulated time series and respiratory recordings from lambs. The following estimation methods were analyzed: fixed-binning with ranking, kernel density estimation (KDE, and the Darbellay-Vajda (D-V adaptive partitioning algorithm extended to three dimensions. In the simulated experiment, sample size was varied from 50 to 200, while coupling strength was increased. In order to introduce outliers, the heavy-tailed Laplace distribution was utilized. In the lamb experiment, the objective was to detect increased respiratory-related chemosensitivity to O2 and CO2 induced by a drug, domperidone. Specifically, the separate influence of end-tidal PO2 and PCO2 on minute ventilation (V˙E before and after administration of domperidone was analyzed. Results In the simulation, KDE detected increased coupling strength at the lowest SNR among the three methods. In the lamb experiment, D-V partitioning resulted in the statistically strongest increase in transfer entropy post-domperidone for PO2→V˙E. In addition, D-V partitioning was the only method that could detect an increase in transfer entropy for PCO2→V˙E, in agreement with experimental findings. Conclusions Transfer entropy is capable of detecting directional coupling changes in non-linear biomedical time series analysis featuring a small number of observations and presence of outliers. The results

  18. Preparation of fluorinated biaryls through direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates

    KAUST Repository

    Fang, Xin

    2013-07-01

    The direct palladium-catalyzed coupling of polyfluoroarenes with aryltrifluoroborates gave the desired products of fluorinated biaryls in good to excellent yields. A diverse set of important functional groups including methoxy, aldehyde, ester, nitro and halide can be well tolerated in the protocol. © 2013 Elsevier B.V. All rights reserved.

  19. Direct Detection and Imaging of Low-Energy Electrons with Delta-Doped Charge-Coupled Devices

    Science.gov (United States)

    Nikzad, S.; Yu, Q.; Smith, A. L.; Jones, T. J.; Tombrello, T. A.; Elliott, S. T.

    1998-01-01

    We report the use fo delta-doped charge-coupled devices (CCDs) for direct detection of electrons in the 50-1500 eV energy range. These are the first measurements with a solid state device to detect electrons in this energy range.

  20. Directly coupled YBCO dc SQUID magnetometers

    International Nuclear Information System (INIS)

    Petersen, P.R.E.; Shen, Y.Q.; Holst, T.; Larsen, B.H.; Sager, M.P.; Bindslev Hansen, J.

    1999-01-01

    YBa 2 Cu 3 O 7- x magnetometers have been made on 10mmx10mm MgO substrates by directly coupling the magnetometer pick-up loop to a dc SQUID with narrow strip lines. The dc SQUIDs were made with YBa 2 Cu 3 O 7-x step-edge Josephson junctions. The layout of the magnetometer pick-up loop was chosen as a compromise between maximizing the loop effective area and minimizing the loop inductance. The SQUID was designed to have L S ∼100 pH in order to obtain β L =2I 0 L S /Φ 0 approx.= 1 with the single-junction critical current I 0 ∼10 μA. We have made magnetometers with white noise levels down to 55 fT Hz -1/2 and a 1/f knee at 1 Hz (ac biased). Noise measurements were made on a field-cooled magnetometer. The noise measured at 1 Hz when cooled in 'zero field' was 175 fT Hz -1/2 . When cooled in magnetic fields of B = 50 μT and B = 100 μT we measured the noise at 1 Hz to be 430 fT Hz -1 2 and 1.3 pT Hz -1/2 , respectively. (author)

  1. Asymmetric flows over symmetric surfaces: capacitive coupling in induced-charge electro-osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Mansuripur, T S [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Pascall, A J; Squires, T M [Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 (United States)], E-mail: squires@engineering.ucsb.edu

    2009-07-15

    We report curious asymmetric induced-charge electro-osmotic (ICEO) flows over a symmetric, planar gate electrode under applied ac electric fields, whereas symmetric, counter-rotating rolls are expected. Furthermore, the asymmetric component of the flow is consistently directed towards the grounded electrode. We propose that capacitive coupling of the gate electrode to the microscope stage-a comparatively large equipotential surface that acts effectively as a ground-is responsible for this symmetry breaking. This stray capacitance drives the formation of a double layer whose zeta potential is proportional to the potential drop from the electrolyte directly above the gate electrode to the external stage. Therefore, the charge in this 'stray' double layer varies in phase with the driving field, resulting in a rectified, steady flow as with standard ICEO. We experimentally vary the stray capacitance, the electric potential of the stage and the location of the gate electrode, and find that the effect on the stray flow is qualitatively consistent with the predictions of the proposed mechanism. In the process, we demonstrate that capacitive coupling offers an additional means of manipulating fluid flow over a polarizable surface.

  2. Asymmetric flows over symmetric surfaces: capacitive coupling in induced-charge electro-osmosis

    International Nuclear Information System (INIS)

    Mansuripur, T S; Pascall, A J; Squires, T M

    2009-01-01

    We report curious asymmetric induced-charge electro-osmotic (ICEO) flows over a symmetric, planar gate electrode under applied ac electric fields, whereas symmetric, counter-rotating rolls are expected. Furthermore, the asymmetric component of the flow is consistently directed towards the grounded electrode. We propose that capacitive coupling of the gate electrode to the microscope stage-a comparatively large equipotential surface that acts effectively as a ground-is responsible for this symmetry breaking. This stray capacitance drives the formation of a double layer whose zeta potential is proportional to the potential drop from the electrolyte directly above the gate electrode to the external stage. Therefore, the charge in this 'stray' double layer varies in phase with the driving field, resulting in a rectified, steady flow as with standard ICEO. We experimentally vary the stray capacitance, the electric potential of the stage and the location of the gate electrode, and find that the effect on the stray flow is qualitatively consistent with the predictions of the proposed mechanism. In the process, we demonstrate that capacitive coupling offers an additional means of manipulating fluid flow over a polarizable surface.

  3. Investigating the performance of directional boundary layer model through staged modeling method

    Science.gov (United States)

    Jeong, Moon-Gyu; Lee, Won-Chan; Yang, Seung-Hune; Jang, Sung-Hoon; Shim, Seong-Bo; Kim, Young-Chang; Suh, Chun-Suk; Choi, Seong-Woon; Kim, Young-Hee

    2011-04-01

    BLM since the feasibility of the BLM has been investigated in many papers[4][5][6]. Instead of fitting the parameters to the wafer critical dimensions (CD) directly, we tried to use the aerial image (AI) from the rigorous simulator with the electromagnetic field (EMF) solver. Usually that kind of method is known as the staged modeling method. To see the advantages of this method we conducted several experiments and observed the results comparing the method of fitting to the wafer CD directly. Through the tests we could observe some remarkable results and confirmed that the staged modeling had better performance in many ways.

  4. Direct lymphography and lower mesentericography - possibilities and limits in determining the localization, stage and operability of rectal cancer

    International Nuclear Information System (INIS)

    Viyachki, I.; Todorova, L.

    1976-01-01

    The indications for direct lymphography and lower mesentericography in determining the localization, stage and operability of rectal cancer are discussed in detail. Direct lymphography was attempted in 23 and lower selective mesentericography in 12 patients with rectal cancer. Essential is only the positive result, although it indicates an advanced malignant process. Lower mesentericography, especially the selective one, furnishes valuable information on the localization and stage of rectal cancer, and hence on its operability. Major importance is attached to the combined use of the two methods. They may thus complement one another in the diagnosis of the early stages of rectal cancer and may be helpful in the search of early recurrences after radical treatment. (author)

  5. Direct catalytic cross-coupling of organolithium compounds

    NARCIS (Netherlands)

    Giannerini, Massimo; Fananas Mastral, Martin; Feringa, Ben L.

    Catalytic carbon-carbon bond formation based on cross-coupling reactions plays a central role in the production of natural products, pharmaceuticals, agrochemicals and organic materials. Coupling reactions of a variety of organometallic reagents and organic halides have changed the face of modern

  6. Blind Direction-of-Arrival Estimation with Uniform Circular Array in Presence of Mutual Coupling

    Directory of Open Access Journals (Sweden)

    Song Liu

    2016-01-01

    Full Text Available A blind direction-of-arrival (DOA estimation algorithm based on the estimation of signal parameters via rotational invariance techniques (ESPRIT is proposed for a uniform circular array (UCA when strong electromagnetic mutual coupling is present. First, an updated UCA model with mutual coupling in a discrete Fourier transform (DFT beam space is deduced, and the new manifold matrix is equal to the product of a centrosymmetric diagonal matrix and a Vandermonde-structure matrix. Then we carry out blind DOA estimation through a modified ESPRIT method, thus avoiding the need for spatial angular searching. In addition, two mutual coupling parameter estimation methods are presented after the DOAs have been estimated. Simulation results show that the new algorithm is reliable and effective especially for closely spaced signals.

  7. Compact four-channel terahertz demultiplexer based on directional coupling photonic crystal

    Science.gov (United States)

    Jiu-Sheng, Li; Han, Liu; Le, Zhang

    2015-09-01

    Electromagnetic polarization conveys valuable information for signal processing. Manipulation of terahertz wavelength demultiplexer exhibits tremendous potential in developing application of terahertz science and technology. We propose an approach to separate efficiently four frequencies terahertz waves based on three cascaded directional coupling two-dimensional photonic crystal waveguides. Both plane wave expansion method and finite-difference time-domain method are used to calculate and analyze the characteristics of the proposed device. The simulation results show that the designed terahertz wavelength demultiplexer can split four different wavelengths of terahertz wave into different propagation directions with high transmittance and low crosstalk. The present device is very compact and the total size is 6.8×10.6 mm2. This enables the terahertz wavelength demultiplexer to be used in terahertz wave system and terahertz wave integrated circuit fields.

  8. Bidirectional communication using delay coupled chaotic directly ...

    Indian Academy of Sciences (India)

    A symmetric bidirectional coupling is identified as a suitable method for isochronal synchronization of such lasers. The optimum values of coupling and feedback strength that can provide maximum quality of synchronization are identified. This method is successfully employed for encoding/decoding both analog and digital ...

  9. Dynamic solar-powered multi-stage direct contact membrane distillation system: Concept design, modeling and simulation

    KAUST Repository

    Lee, Jung Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, NorEddine; Kim, Young-Deuk

    2017-01-01

    This paper presents a theoretical analysis of the monthly average daily and hourly performances of a solar-powered multi-stage direct contact membrane distillation (SMDCMD) system with an energy recovery scheme and dynamic operating system. Mid

  10. Sparse networks of directly coupled, polymorphic, and functional side chains in allosteric proteins.

    Science.gov (United States)

    Soltan Ghoraie, Laleh; Burkowski, Forbes; Zhu, Mu

    2015-03-01

    Recent studies have highlighted the role of coupled side-chain fluctuations alone in the allosteric behavior of proteins. Moreover, examination of X-ray crystallography data has recently revealed new information about the prevalence of alternate side-chain conformations (conformational polymorphism), and attempts have been made to uncover the hidden alternate conformations from X-ray data. Hence, new computational approaches are required that consider the polymorphic nature of the side chains, and incorporate the effects of this phenomenon in the study of information transmission and functional interactions of residues in a molecule. These studies can provide a more accurate understanding of the allosteric behavior. In this article, we first present a novel approach to generate an ensemble of conformations and an efficient computational method to extract direct couplings of side chains in allosteric proteins, and provide sparse network representations of the couplings. We take the side-chain conformational polymorphism into account, and show that by studying the intrinsic dynamics of an inactive structure, we are able to construct a network of functionally crucial residues. Second, we show that the proposed method is capable of providing a magnified view of the coupled and conformationally polymorphic residues. This model reveals couplings between the alternate conformations of a coupled residue pair. To the best of our knowledge, this is the first computational method for extracting networks of side chains' alternate conformations. Such networks help in providing a detailed image of side-chain dynamics in functionally important and conformationally polymorphic sites, such as binding and/or allosteric sites. © 2014 Wiley Periodicals, Inc.

  11. Direct Numerical Simulation of Turbulent Multi-Stage Autoignition Relevant to Engine Conditions

    Science.gov (United States)

    Chen, Jacqueline

    2017-11-01

    Due to the unrivaled energy density of liquid hydrocarbon fuels combustion will continue to provide over 80% of the world's energy for at least the next fifty years. Hence, combustion needs to be understood and controlled to optimize combustion systems for efficiency to prevent further climate change, to reduce emissions and to ensure U.S. energy security. In this talk I will discuss recent progress in direct numerical simulations of turbulent combustion focused on providing fundamental insights into key `turbulence-chemistry' interactions that underpin the development of next generation fuel efficient, fuel flexible engines for transportation and power generation. Petascale direct numerical simulation (DNS) of multi-stage mixed-mode turbulent combustion in canonical configurations have elucidated key physics that govern autoignition and flame stabilization in engines and provide benchmark data for combustion model development under the conditions of advanced engines which operate near combustion limits to maximize efficiency and minimize emissions. Mixed-mode combustion refers to premixed or partially-premixed flames propagating into stratified autoignitive mixtures. Multi-stage ignition refers to hydrocarbon fuels with negative temperature coefficient behavior that undergo sequential low- and high-temperature autoignition. Key issues that will be discussed include: 1) the role of mixing in shear driven turbulence on the dynamics of multi-stage autoignition and cool flame propagation in diesel environments, 2) the role of thermal and composition stratification on the evolution of the balance of mixed combustion modes - flame propagation versus spontaneous ignition - which determines the overall combustion rate in autoignition processes, and 3) the role of cool flames on lifted flame stabilization. Finally prospects for DNS of turbulent combustion at the exascale will be discussed in the context of anticipated heterogeneous machine architectures. sponsored by DOE

  12. Foot segmental motion and coupling in stage II and III tibialis posterior tendon dysfunction.

    Science.gov (United States)

    Van de Velde, Maarten; Matricali, Giovanni Arnoldo; Wuite, Sander; Roels, Charlotte; Staes, Filip; Deschamps, Kevin

    2017-06-01

    Classification systems developed in the field of posterior tibialis tendon dysfunction omit to include dynamic measurements. Since this may negatively affect the selection of the most appropriate treatment modality, studies on foot kinematics are highly recommended. Previous research characterised the foot kinematics in patients with posterior tibialis tendon dysfunction. However, none of the studies analysed foot segmental motion synchrony during stance phase, nor compared the kinematic behaviour of the foot in presence of different posterior tibialis tendon dysfunction stages. Therefore, we aimed at comparing foot segmental motion and coupling in patients with posterior tibialis tendon dysfunction grade 2 and 3 to those of asymptomatic subjects. Foot segmental motion of 11 patients suffering from posterior tibialis tendon dysfunction stage 2, 4 patients with posterior tibialis tendon dysfunction stage 3 and 15 asymptomatic subjects was objectively quantified with the Rizzoli foot model using an instrumented walkway and a 3D passive motion capture system. Dependent variables were the range of motion occurring at the different inter-segment angles during subphases of stance and swing phase as well as the cross-correlation coefficient between a number of segments. Significant differences in range of motion were predominantly found during the forefoot push off phase and swing phase. In general, both patient cohorts demonstrated a reduced range of motion compared to the control group. This hypomobility occurred predominantly in the rearfoot and midfoot (pfoot which should be considered in the decision making process since it may help explaining the success and failure of certain conservative and surgical interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches

    KAUST Repository

    Lee, Jung Gil

    2016-10-24

    An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m2 at each stage is found to be 21.5 kg.

  14. Robustness and versatility of a nonlinear interdependence method for directional coupling detection from spike trains

    Science.gov (United States)

    Malvestio, Irene; Kreuz, Thomas; Andrzejak, Ralph G.

    2017-08-01

    The detection of directional couplings between dynamics based on measured spike trains is a crucial problem in the understanding of many different systems. In particular, in neuroscience it is important to assess the connectivity between neurons. One of the approaches that can estimate directional coupling from the analysis of point processes is the nonlinear interdependence measure L . Although its efficacy has already been demonstrated, it still needs to be tested under more challenging and realistic conditions prior to an application to real data. Thus, in this paper we use the Hindmarsh-Rose model system to test the method in the presence of noise and for different spiking regimes. We also examine the influence of different parameters and spike train distances. Our results show that the measure L is versatile and robust to various types of noise, and thus suitable for application to experimental data.

  15. Three semi-direct sum Lie algebras and three discrete integrable couplings associated with the modified K dV lattice equation

    International Nuclear Information System (INIS)

    Yu Zhang; Zhang Yufeng

    2009-01-01

    Three semi-direct sum Lie algebras are constructed, which is an efficient and new way to obtain discrete integrable couplings. As its applications, three discrete integrable couplings associated with the modified K dV lattice equation are worked out. The approach can be used to produce other discrete integrable couplings of the discrete hierarchies of soliton equations.

  16. Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

    Science.gov (United States)

    Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

    2015-02-01

    A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

  17. Single-stage three-phase AC to DC conversion with isolation and Bi-directional power flow

    NARCIS (Netherlands)

    Vermulst, B.J.D.; Duarte, J.L.; Wijnands, C.G.E.; Lomonova, E.A.

    2014-01-01

    An approach for three-phase AC to DC conversion is proposed, which consists of a single-stage while offering galvanic isolation, soft-switching, bi-directional power flow and a significant reduction of inductive and capacitive energy storage. Two elements enable this approach, namely a neutral

  18. Late-stage diversification of biologically active pyridazinones via a direct C-H functionalization strategy.

    Science.gov (United States)

    Li, Wei; Fan, Zhoulong; Geng, Kaijun; Xu, Youjun; Zhang, Ao

    2015-01-14

    Divergent C-H functionalization reactions (arylation, carboxylation, olefination, thiolation, acetoxylation, halogenation, naphthylation) using a pyridazinone moiety as an internal directing group were successfully established. This approach offers a late-stage, ortho-selective diversification of a biologically active pyridazinone scaffold. Seven series of novel pyridazinone analogues were synthesized conveniently as the synthetic precursors of potential sortase A (SrtA) inhibitors.

  19. Direct Coupling of Thermo- and Photocatalysis for Conversion of CO2 -H2 O into Fuels.

    Science.gov (United States)

    Zhang, Li; Kong, Guoguo; Meng, Yaping; Tian, Jinshu; Zhang, Lijie; Wan, Shaolong; Lin, Jingdong; Wang, Yong

    2017-12-08

    Photocatalytic CO 2 reduction into renewable hydrocarbon solar fuels is considered as a promising strategy to simultaneously address global energy and environmental issues. This study focused on the direct coupling of photocatalytic water splitting and thermocatalytic hydrogenation of CO 2 in the conversion of CO 2 -H 2 O into fuels. Specifically, it was found that direct coupling of thermo- and photocatalysis over Au-Ru/TiO 2 leads to activity 15 times higher (T=358 K; ca. 99 % CH 4 selectivity) in the conversion of CO 2 -H 2 O into fuels than that of photocatalytic water splitting. This is ascribed to the promoting effect of thermocatalytic hydrogenation of CO 2 by hydrogen atoms generated in situ by photocatalytic water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Photovoltaic pumping system - Comparative study analysis between direct and indirect coupling mode

    Science.gov (United States)

    Harrag, Abdelghani; Titraoui, Abdessalem; Bahri, Hamza; Messalti, Sabir

    2017-02-01

    In this paper, P&O algorithm is used in order to improve the performance of photovoltaic water pumping system in both dynamic and static response. The efficiency of the proposed algorithm has been studied successfully using a DC motor-pump powered using controller by thirty six PV modules via DC-DC boost converter derived by a P&O MPPT algorithm. Comparative study results between the direct and indirect modes coupling confirm that the proposed algorithm can effectively improve simultaneously: accuracy, rapidity, ripple and overshoot.

  1. A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches.

    Science.gov (United States)

    Lee, Jung-Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, Noreddine; Kim, Young-Deuk

    2016-12-15

    An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m 2  at each stage is found to be 21.5 kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Coupled motions direct electrons along human microsomal P450 Chains.

    Directory of Open Access Journals (Sweden)

    Christopher R Pudney

    2011-12-01

    Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron

  3. Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

    Science.gov (United States)

    Kasch, Richard; Merk, Sebastian; Assmann, Grit; Lahm, Andreas; Napp, Matthias; Merk, Harry; Flessa, Steffen

    2017-01-01

    Background The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available. Questions/Purposes A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department’s perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations. Methods A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department’s perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes. Results Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p cost drivers were the cost of the implant and

  4. Pre-capacity building in loosely-coupled collaborations: Setting the stage for future initiatives

    Directory of Open Access Journals (Sweden)

    Cheryl A. Hyde

    2012-08-01

    Full Text Available This article examines the benefits and limitations of ‘loosely-coupled’ research collaborations between university faculty and 12 grassroots community-based organisations (CBOs. The authors assert that community-based research projects that develop the knowledge base within CBOs, and can be described as ‘pre-capacity building’ work, can be an important stepping stone to the subsequent development of more formal and strategic capacity-building partnership ventures. However, such projects must be approached carefully with a clear understanding of the ‘threshold dimensions’ that must be met before proceeding with any collaboration. Written as a cautionary tale, the authors identify some of the problems that arise when the threshold stage is poorly executed, and more generally speak to the dangers of initiating even loosely-coupled collaborations in the absence of an explicit and well-established campus commitment to and support for community engagement and partnerships. Keywords: Community capacity-building, community-university partnerships, community research, collaboration

  5. A novel voice coil motor-driven compliant micropositioning stage based on flexure mechanism

    Science.gov (United States)

    Shang, Jiangkun; Tian, Yanling; Li, Zheng; Wang, Fujun; Cai, Kunhai

    2015-09-01

    This paper presents a 2-degrees of freedom flexure-based micropositioning stage with a flexible decoupling mechanism. The stage is composed of an upper planar stage and four vertical support links to improve the out-of-plane stiffness. The moving platform is driven by two voice coil motors, and thus it has the capability of large working stroke. The upper stage is connected with the base through six double parallel four-bar linkages mechanisms, which are orthogonally arranged to implement the motion decoupling in the x and y directions. The vertical support links with serially connected hook joints are utilized to guarantee good planar motion with heavy-loads. The static stiffness and the dynamic resonant frequencies are obtained based on the theoretical analyses. Finite element analysis is used to investigate the characteristics of the developed stage. Experiments are carried out to validate the established models and the performance of the developed stage. It is noted that the developed stage has the capability of translational motion stroke of 1.8 mm and 1.78 mm in working axes. The maximum coupling errors in the x and y directions are 0.65% and 0.82%, respectively, and the motion resolution is less than 200 nm. The experimental results show that the developed stage has good capability for trajectory tracking.

  6. Photons from the early stages of relativistic heavy-ion collisions

    Science.gov (United States)

    Oliva, L.; Ruggieri, M.; Plumari, S.; Scardina, F.; Peng, G. X.; Greco, V.

    2017-07-01

    We present results about photon-production in relativistic heavy-ion collisions. The main novelty of our study is the calculation of the contribution of the early-stage photons to the photon spectrum. The initial stage is modeled by an ensemble of classical gluon fields which decay to a quark-gluon plasma via the Schwinger mechanism, and the evolution of the system is studied by coupling classical field equations to relativistic kinetic theory; photon production is then computed by including the pertinent collision processes into the collision integral. We find that the contribution of the early-stage photons to the direct photon spectrum is substantial for pT≈2 GeV and higher, the exact value depending on the collision energy; therefore, we identify this part of the photon spectrum as the sign of the early stage. Moreover, the amount of photons produced during the early stage is not negligible with respect to those produced by a thermalized quark-gluon plasma: We support the idea that there is no dark age in relativistic heavy-ion collisions.

  7. Staging laser plasma accelerators for increased beam energy

    International Nuclear Information System (INIS)

    Panasenko, Dmitriy; Shu, Anthony; Schroeder, Carl; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Cormier-Michel, Estelle; Plateau, Guillaume; Lin, Chen; Toth, Csaba; Geddes, Cameron; Esarey, Eric; Leemans, Wim

    2008-01-01

    Staging laser plasma accelerators is an efficient way of mitigating laser pump depletion in laser driven accelerators and necessary for reaching high energies with compact laser systems. The concept of staging includes coupling of additional laser energy and transporting the electron beam from one accelerating module to another. Due to laser damage threshold constraints, in-coupling laser energy with conventional optics requires distances between the accelerating modules of the order of 10m, resulting in decreased average accelerating gradient and complicated e-beam transport. In this paper we use basic scaling laws to show that the total length of future laser plasma accelerators will be determined by staging technology. We also propose using a liquid jet plasma mirror for in-coupling the laser beam and show that it has the potential to reduce distance between stages to the cm-scale.

  8. Acquired Immune Deficiency Syndrome: A Preliminary Examination of the Effects on Gay Couples and Coupling.

    Science.gov (United States)

    Carl, Douglas

    1986-01-01

    The Acquired Immune Deficiency Syndrome (AIDS) epidemic significantly influences attitudes about life and lifestyles. Homosexuals have to give increased consideration to coupling, the nature of coupled relationships, sex and intimacy, and death long before the normal time. Discusses impact of AIDS on the early stages of gay coupling and on the…

  9. Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry of drug residues from latent fingerprints.

    Science.gov (United States)

    Clemons, Kristina; Wiley, Rachel; Waverka, Kristin; Fox, James; Dziekonski, Eric; Verbeck, Guido F

    2013-07-01

    Here, we present a method of extracting drug residues from fingerprints via Direct Analyte-Probed Nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS). This instrumental technique provides higher selectivity and lower detection limits over current methods, greatly reducing sample preparation, and does not compromise the integrity of latent fingerprints. This coupled to Raman microscopy is an advantageous supplement for location and identification of trace particles. DAPNe uses a nanomanipulator for extraction and differing microscopies for localization of chemicals of interest. A capillary tip with solvent of choice is placed in a nanopositioner. The surface to be analyzed is placed under a microscope, and a particle of interest is located. Using a pressure injector, the solvent is injected onto the surface where it dissolves the analyte, and then extracted back into the capillary tip. The solution is then directly analyzed via NSI-MS. Analyses of caffeine, cocaine, crystal methamphetamine, and ecstasy have been performed successfully. © 2013 American Academy of Forensic Sciences.

  10. Estimation of Direct Melanoma-related Costs by Disease Stage and by Phase of Diagnosis and Treatment According to Clinical Guidelines

    Directory of Open Access Journals (Sweden)

    Alessandra Buja

    2017-11-01

    Full Text Available Cutaneous melanoma is a major concern in terms of healthcare systems and economics. The aim of this study was to estimate the direct costs of melanoma by disease stage, phase of diagnosis, and treatment according to the pre-set clinical guidelines drafted by the AIOM (Italian Medical Oncological Association. Based on the AIOM guidelines for malignant cutaneous melanoma, a highly detailed decision-making model was developed describing the patient’s pathway from diagnosis through the subsequent phases of disease staging, surgical and medical treatment, and follow-up. The model associates each phase potentially involving medical procedures with a likelihood measure and a cost, thus enabling an estimation of the expected costs by disease stage and clinical phase of melanoma diagnosis and treatment according to the clinical guidelines. The mean per-patient cost of the whole melanoma pathway (including one year of follow-up ranged from €149 for stage 0 disease to €66,950 for stage IV disease. The costs relating to each phase of the disease’s diagnosis and treatment depended on disease stage. It is essential to calculate the direct costs of managing malignant cutaneous melanoma according to clinical guidelines in order to estimate the economic burden of this disease and to enable policy-makers to allocate appropriate resources.

  11. Distributed coupling high efficiency linear accelerator

    Science.gov (United States)

    Tantawi, Sami G.; Neilson, Jeffrey

    2016-07-19

    A microwave circuit for a linear accelerator includes multiple monolithic metallic cell plates stacked upon each other so that the beam axis passes vertically through a central acceleration cavity of each plate. Each plate has a directional coupler with coupling arms. A first coupling slot couples the directional coupler to an adjacent directional coupler of an adjacent cell plate, and a second coupling slot couples the directional coupler to the central acceleration cavity. Each directional coupler also has an iris protrusion spaced from corners joining the arms, a convex rounded corner at a first corner joining the arms, and a corner protrusion at a second corner joining the arms.

  12. Bi-directional ultrasonic wave coupling to FBGs in continuously bonded optical fiber sensing.

    Science.gov (United States)

    Wee, Junghyun; Hackney, Drew; Bradford, Philip; Peters, Kara

    2017-09-01

    Fiber Bragg grating (FBG) sensors are typically spot-bonded onto the surface of a structure to detect ultrasonic waves in laboratory demonstrations. However, to protect the rest of the optical fiber from any environmental damage during real applications, bonding the entire length of fiber, called continuous bonding, is commonly done. In this paper, we investigate the impact of continuously bonding FBGs on the measured Lamb wave signal. In theory, the ultrasonic wave signal can bi-directionally transfer between the optical fiber and the plate at any adhered location, which could potentially produce output signal distortion for the continuous bonding case. Therefore, an experiment is performed to investigate the plate-to-fiber and fiber-to-plate signal transfer, from which the signal coupling coefficient of each case is theoretically estimated based on the experimental data. We demonstrate that the two coupling coefficients are comparable, with the plate-to-fiber case approximately 19% larger than the fiber-to-plate case. Finally, the signal waveform and arrival time of the output FBG responses are compared between the continuous and spot bonding cases. The results indicate that the resulting Lamb wave signal output is only that directly detected at the FBG location; however, a slight difference in signal waveform is observed between the two bonding configurations. This paper demonstrates the practicality of using continuously bonded FBGs for ultrasonic wave detection in structural health monitoring (SHM) applications.

  13. Obtaining high-resolution stage forecasts by coupling large-scale hydrologic models with sensor data

    Science.gov (United States)

    Fries, K. J.; Kerkez, B.

    2017-12-01

    We investigate how "big" quantities of distributed sensor data can be coupled with a large-scale hydrologic model, in particular the National Water Model (NWM), to obtain hyper-resolution forecasts. The recent launch of the NWM provides a great example of how growing computational capacity is enabling a new generation of massive hydrologic models. While the NWM spans an unprecedented spatial extent, there remain many questions about how to improve forecast at the street-level, the resolution at which many stakeholders make critical decisions. Further, the NWM runs on supercomputers, so water managers who may have access to their own high-resolution measurements may not readily be able to assimilate them into the model. To that end, we ask the question: how can the advances of the large-scale NWM be coupled with new local observations to enable hyper-resolution hydrologic forecasts? A methodology is proposed whereby the flow forecasts of the NWM are directly mapped to high-resolution stream levels using Dynamical System Identification. We apply the methodology across a sensor network of 182 gages in Iowa. Of these sites, approximately one third have shown to perform well in high-resolution flood forecasting when coupled with the outputs of the NWM. The quality of these forecasts is characterized using Principal Component Analysis and Random Forests to identify where the NWM may benefit from new sources of local observations. We also discuss how this approach can help municipalities identify where they should place low-cost sensors to most benefit from flood forecasts of the NWM.

  14. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    Science.gov (United States)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  15. [Coupling coordinated development of ecological-economic system in Loess Plateau].

    Science.gov (United States)

    Zhang, Qing-Feng; Wu, Fa-Qi; Wang, Li; Wang, Jian

    2011-06-01

    Based on system theory, a coupling coordinated development model of ecological-economic system in Loess Plateau was established, and the evaluation criteria and basic types of the coordinated development of the ecological-economic system were proposed. The county-level coupling coordinated development of the ecological-economic system was also discussed, based on the local characteristics. The interactions between the ecological and economic systems in Loess Plateau could be divided into four stages, i.e., seriously disordered development stage, mild-disordered development stage, low-level coordinated development stage, and high level well-coordinated development stage. At each stage, there existed a cyclic process of profit and loss-antagonist-running-dominant-synchronous development. The coupling development degree of the ecological-economic system in Loess Plateau was overall at a lower level, being about 62.7% of the counties at serious disorder, 30.1% of the counties at mild disorder, and 7.1% of the counties at low but coordinated level. The coupling development degree based on the model established in this study could better reflect the current social-economic and ecological environment situations, especially the status of coordination. To fully understand the coupling of ecological-economic system and to adopt appropriate development mode would be of significance to promote the county-level coordinated development in Loess Plateau.

  16. Direct-coupled-ray method for design-oriented three-dimensional transport analysis

    International Nuclear Information System (INIS)

    Bucholz, J.A.; Poncelet, C.G.

    1977-01-01

    A fast three-dimensional design-oriented transport method has been developed for the solution of both neutron and gamma transport problems. It combines a nodal approach with analytic integral transport to achieve relative speed and accuracy. An analytic solution is obtained for the angular flux in each of the 14 directions defined by the six faces and eight corners of a cubic mesh block. The scheme used to accommodate high-order anisotropic scattering is based on the formulation of ray-to-ray scattering probabilities in an integral sense. A variable mesh approximation has also been introduced to provide greater flexibility. The details of a direct-coupled-ray (DCR) → P 1 conversion technique have been developed but not yet implemented. The DCR method, as implemented in the TRANS3 code, has been used in a number of liquid-metal fast breeder reactor shielding applications. These included a one-dimensional deep penetration configuration and one-, two-, and three dimensional representations of the lower axial shield of the Clinch River Breeder Reactor. Comparisons with ANISN and DOT-III solutions indicated good to excellent agreement in most situations

  17. Evaluation of Air Coupled Ultrasound for Composite Aerospace Structure

    Science.gov (United States)

    Tat, H.; Georgeson, G.; Bossi, R.

    2009-03-01

    Non-contact air coupled ultrasound suffers from the high acoustic impedance mismatch characteristics of air to solid interfaces. Advances in transducer technology, particularly MEMS, have improved the acoustic impedance match at the transmission stage and the signal to noise at the reception stage. Comparisons of through transmission (TTU) scanning of laminate and honeycomb test samples using conventional piezoelectric air coupled transducers, new MEMS air coupled transducers, and standard water coupled inspections have been performed to assess the capability. An additional issue for air coupled UT inspection is the need for a lean implementation for both manufacturing and in-service operations. Concepts and applications utilizing magnetic coupling of transducers have been developed that allows air coupled inspection operations in compact low cost configurations.

  18. Direct dimethyl ether (DME) synthesis through a thermally coupled heat exchanger reactor

    International Nuclear Information System (INIS)

    Vakili, R.; Pourazadi, E.; Setoodeh, P.; Eslamloueyan, R.; Rahimpour, M.R.

    2011-01-01

    Compared to some of the alternative fuel candidates such as methane, methanol and Fischer-Tropsch fuels, dimethyl ether (DME) seems to be a superior candidate for high-quality diesel fuel in near future. The direct synthesis of DME from syngas would be more economical and beneficial in comparison with the indirect process via methanol synthesis. Multifunctional auto-thermal reactors are novel concepts in process intensification. A promising field of applications for these concepts could be the coupling of endothermic and exothermic reactions in heat exchanger reactors. Consequently, in this study, a double integrated reactor for DME synthesis (by direct synthesis from syngas) and hydrogen production (by the cyclohexane dehydrogenation) is modelled based on the heat exchanger reactors concept and a steady-state heterogeneous one-dimensional mathematical model is developed. The corresponding results are compared with the available data for a pipe-shell fixed bed reactor for direct DME synthesis which is operating at the same feed conditions. In this novel configuration, DME production increases about 600 Ton/year. Also, the effects of some operational parameters such as feed flow rates and the inlet temperatures of exothermic and endothermic sections on reactor behaviour are investigated. The performance of the reactor needs to be proven experimentally and tested over a range of parameters under practical operating conditions.

  19. Two stages of directed forgetting: Electrophysiological evidence from a short-term memory task.

    Science.gov (United States)

    Gao, Heming; Cao, Bihua; Qi, Mingming; Wang, Jing; Zhang, Qi; Li, Fuhong

    2016-06-01

    In this study, a short-term memory test was used to investigate the temporal course and neural mechanism of directed forgetting under different memory loads. Within each trial, two memory items with high or low load were presented sequentially, followed by a cue indicating whether the presented items should be remembered. After an interval, subjects were asked to respond to the probe stimuli. The ERPs locked to the cues showed that (a) the effect of cue type was initially observed during the P2 (160-240 ms) time window, with more positive ERPs for remembering relative to forgetting cues; (b) load effects were observed during the N2-P3 (250-500 ms) time window, with more positive ERPs for the high-load than low-load condition; (c) the cue effect was also observed during the N2-P3 time window, with more negative ERPs for forgetting versus remembering cues. These results demonstrated that directed forgetting involves two stages: task-relevance identification and information discarding. The cue effects during the N2 epoch supported the view that directed forgetting is an active process. © 2016 Society for Psychophysiological Research.

  20. Direct analysis of ultra-trace semiconductor gas by inductively coupled plasma mass spectrometry coupled with gas to particle conversion-gas exchange technique.

    Science.gov (United States)

    Ohata, Masaki; Sakurai, Hiromu; Nishiguchi, Kohei; Utani, Keisuke; Günther, Detlef

    2015-09-03

    An inductively coupled plasma mass spectrometry (ICPMS) coupled with gas to particle conversion-gas exchange technique was applied to the direct analysis of ultra-trace semiconductor gas in ambient air. The ultra-trace semiconductor gases such as arsine (AsH3) and phosphine (PH3) were converted to particles by reaction with ozone (O3) and ammonia (NH3) gases within a gas to particle conversion device (GPD). The converted particles were directly introduced and measured by ICPMS through a gas exchange device (GED), which could penetrate the particles as well as exchange to Ar from either non-reacted gases such as an air or remaining gases of O3 and NH3. The particle size distribution of converted particles was measured by scanning mobility particle sizer (SMPS) and the results supported the elucidation of particle agglomeration between the particle converted from semiconductor gas and the particle of ammonium nitrate (NH4NO3) which was produced as major particle in GPD. Stable time-resolved signals from AsH3 and PH3 in air were obtained by GPD-GED-ICPMS with continuous gas introduction; however, the slightly larger fluctuation, which could be due to the ionization fluctuation of particles in ICP, was observed compared to that of metal carbonyl gas in Ar introduced directly into ICPMS. The linear regression lines were obtained and the limits of detection (LODs) of 1.5 pL L(-1) and 2.4 nL L(-1) for AsH3 and PH3, respectively, were estimated. Since these LODs revealed sufficiently lower values than the measurement concentrations required from semiconductor industry such as 0.5 nL L(-1) and 30 nL L(-1) for AsH3 and PH3, respectively, the GPD-GED-ICPMS could be useful for direct and high sensitive analysis of ultra-trace semiconductor gas in air. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. A new coupled system for BWR nuclear fuel management

    International Nuclear Information System (INIS)

    Castillo, A.; Ortiz-Servin, J.J.; Montes-Tadeo, J.L.; Perusquia, R.; Rizos, R.L.M.

    2015-01-01

    In this work, a system to solve four stages of the fuel management problem is showed.The system uses different heuristic techniques to solve each stage of that area, and this problem is solved in a coupled way. Considered problems correspond to the following designs: fuel lattice, fuel assembly, fuel reload and control rod patterns. Even though, each stage of the problem can have its own objective function, the complete problem was solved using a multi-objective function. The solution strategy is to solve each stage of design in an iterative process, taking into account previous results for the next stage, until to achieve a complete solution. The solution strategy to solve the coupled problem is the following: the first solved stage is the fuel lattice design, the second one is fuel assembly design, finally an internal loop between both fuel reload design and control rod pattern design is carried out.For this internal loop, a seed reload using Haling principle is generated. The obtained results showed the advantage to solve the whole problem in a coupled way. (author)

  2. Circuit-quantum electrodynamics with direct magnetic coupling to single-atom spin qubits in isotopically enriched 28Si

    Directory of Open Access Journals (Sweden)

    Guilherme Tosi

    2014-08-01

    Full Text Available Recent advances in silicon nanofabrication have allowed the manipulation of spin qubits that are extremely isolated from noise sources, being therefore the semiconductor equivalent of single atoms in vacuum. We investigate the possibility of directly coupling an electron spin qubit to a superconducting resonator magnetic vacuum field. By using resonators modified to increase the vacuum magnetic field at the qubit location, and isotopically purified 28Si substrates, it is possible to achieve coupling rates faster than the single spin dephasing. This opens up new avenues for circuit-quantum electrodynamics with spins, and provides a pathway for dispersive read-out of spin qubits via superconducting resonators.

  3. Multistage Coupling of Laser-Wakefield Accelerators with Curved Plasma Channels

    Science.gov (United States)

    Luo, J.; Chen, M.; Wu, W. Y.; Weng, S. M.; Sheng, Z. M.; Schroeder, C. B.; Jaroszynski, D. A.; Esarey, E.; Leemans, W. P.; Mori, W. B.; Zhang, J.

    2018-04-01

    Multistage coupling of laser-wakefield accelerators is essential to overcome laser energy depletion for high-energy applications such as TeV-level electron-positron colliders. Current staging schemes feed subsequent laser pulses into stages using plasma mirrors while controlling electron beam focusing with plasma lenses. Here a more compact and efficient scheme is proposed to realize the simultaneous coupling of the electron beam and the laser pulse into a second stage. A partly curved channel, integrating a straight acceleration stage with a curved transition segment, is used to guide a fresh laser pulse into a subsequent straight channel, while the electrons continue straight. This scheme benefits from a shorter coupling distance and continuous guiding of the electrons in plasma while suppressing transverse beam dispersion. Particle-in-cell simulations demonstrate that the electron beam from a previous stage can be efficiently injected into a subsequent stage for further acceleration while maintaining high capture efficiency, stability, and beam quality.

  4. Design and modelling of an innovative three-stage thermal storage system for direct steam generation CSP plants

    Science.gov (United States)

    Garcia, Pierre; Vuillerme, Valéry; Olcese, Marco; El Mourchid, Nadim

    2016-05-01

    Thermal Energy Storage systems (TES) for a Direct Steam Generation (DSG) solar plant feature preferably three stages in series including a latent heat storage module so that steam can be recovered with a limited temperature loss. The storage system designed within the Alsolen Sup project is characterized by an innovative combination of sensible and latent modules. A dynamic model of this three-stage storage has been developed and applied to size the storage system of the Alsolen Sup® plant demonstrator at CEA Cadarache. Results of this simulation show that this promising concept is an efficient way to store heat in DSG solar plants.

  5. Reduction of Cogging Torque in Dual Rotor Permanent Magnet Generator for Direct Coupled Wind Energy Systems

    Science.gov (United States)

    Paulsamy, Sivachandran

    2014-01-01

    In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions. PMID:25202746

  6. Reduction of cogging torque in dual rotor permanent magnet generator for direct coupled wind energy systems.

    Science.gov (United States)

    Paulsamy, Sivachandran

    2014-01-01

    In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions.

  7. Experimental investigation of a multi-stage humidification-dehumidification desalination system heated directly by a cylindrical Fresnel lens solar concentrator

    International Nuclear Information System (INIS)

    Wu, Gang; Zheng, Hongfei; Ma, Xinglong; Kutlu, Cagri; Su, Yuehong

    2017-01-01

    Highlights: • A solar desalination system heated directly by curved Fresnel lens concentrator. • Desalination system is based on the humidification-dehumidification process. • Four-stage multi-effect desalination system is proposed. • Condensation latent heat and residual heat in the brine are recycled and reutilized. • The maximum yield and GOR of the unit can reach 3.4 kg/h and 2.1, respectively. - Abstract: This study demonstrates a multi-stage humidification-dehumidification (HDH) solar desalination system heated directly by a cylindrical Fresnel lens concentrator. In this novel system, the solar radiation is sent directly into desalination unit. That is to say, the solar receiver and the evaporator of the system are a whole in which the black fillers in seawater directly absorb the concentrated solar lights to heat the seawater film to produce the evaporation. The configuration and working processes of the proposed design are described in detail. In order to analyze its performance, a small solar desalination prototype unit incorporated with a cylindrical Fresnel lens concentrator was designed and built in our laboratory. Using three-stage isothermal tandem heating mode, the variation of the fresh water yield rate and the absorber temperature with time were measured experimentally and were compared with theoretical calculations. The experimental results show that the maximum yield of the unit is about 3.4 kg/h, the maximum gained output ratio (GOR) is about 2.1, when the average intensity of solar radiation is about 867 W/m"2. This study indicates that the proposed system has the characteristics of compact structure and GOR high. It still can be improved when the design and operation are optimized further.

  8. Staging of laser-plasma accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Steinke, S., E-mail: ssteinke@lbl.gov; Tilborg, J. van; Benedetti, C.; Geddes, C. G. R.; Gonsalves, A. J.; Nakamura, K.; Schroeder, C. B.; Esarey, E. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Daniels, J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven (Netherlands); Swanson, K. K.; Shaw, B. H.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); University of California, Berkeley, California 94720 (United States)

    2016-05-15

    We present results of an experiment where two laser-plasma-accelerator stages are coupled at a short distance by a plasma mirror. Stable electron beams from the first stage were used to longitudinally probe the dark-current-free, quasi-linear wakefield excited by the laser of the second stage. Changing the arrival time of the electron beam with respect to the second stage laser pulse allowed reconstruction of the temporal wakefield structure, determination of the plasma density, and inference of the length of the electron beam. The first stage electron beam could be focused by an active plasma lens to a spot size smaller than the transverse wake size at the entrance of the second stage. This permitted electron beam trapping, verified by a 100 MeV energy gain.

  9. Iodine-Catalyzed Direct Olefination of 2-Oxindoles and Alkenes via Cross-Dehydrogenative Coupling (CDC) in Air.

    Science.gov (United States)

    Huang, Hong-Yan; Wu, Hong-Ru; Wei, Feng; Wang, Dong; Liu, Li

    2015-08-07

    A direct intermolecular olefination of sp(3) C-H bond between 2-oxindoles and simple alkenes via a Cross-Dehydrogenative Coupling (CDC) strategy has been developed. In the absence of additional base, moderate to excellent yields have been obtained by using a catalytic amount of iodine with atmospheric oxygen as the reoxidant. Based on the observation of a radical capture experiment, the transformation is proposed to proceed via a radical process.

  10. Investigation of multi-stage cold forward extrusion process using coupled thermo-mechanical finite element analysis

    Science.gov (United States)

    Görtan, Mehmet Okan

    2018-05-01

    Cold extrusion processes are distinguished by their low material usage as well as great efficiency in the production of mid-range and large component series. Although majority of the cold extruded parts are produced using die systems containing multiple forming stages, this subject has rarely been investigated so far. Therefore, the characteristics of multi-stage cold forward rod extrusion is studied in the current work using thermo-mechanically coupled finite element (FE) analysis. A case hardening steel, 16MnCr5 (1.7131) was used as experimental material. Its strain, strain rate and temperature dependent mechanical characteristics were determined using compression testing and modeled in FE simulations via a Johnson-Cook material model. Friction coefficients for the same material while in contact with a tool steel (1.2379) were determined dependent on temperature and contact pressure using sliding compression test (SCT) and modeled by an adaptive friction model developed by the author. In the first set of simulations, rod material with a diameter of 14.9 mm was extruded down to a diameter of 9.6 mm in a single step using three different die opening angles (2α); 20°, 40° and 60°. In the second set of investigations, the same rod was reduced first to 12 mm and then to 9.6 mm in two steps within the same forming die. Press forces, contact normal stresses between extruded material and forming die, material temperature and axial stresses are compared in these two set of simulations and the differences are discussed.

  11. Current limiting characteristics of transformer type SFCL with coupled secondary windings according to its winding direction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sung Hun [Dept. of Electrical Engineering, Soongsil University, Seoul (Korea, Republic of); Han, Tae Hee [Dept. of Aero Materials Engineering, Jungwon University, Goesan (Korea, Republic of)

    2017-06-15

    In this paper, the current limiting characteristics of the transformer type superconducting fault current limiter (SFCL) with the two coupled secondary windings due to its winding direction were analyzed. To analyze the dependence of transient fault current limiting characteristics on the winding direction of the additional secondary winding, the fault current limiting tests of the SFCL with an additional secondary winding, wound as subtractive polarity winding and additive polarity winding, were carried out. The time interval of quench occurrence between two superconducting elements comprising the transformer type SFCL with the additional secondary winding was confirmed to be affected by the winding direction of the additional secondary winding. In case of the subtractive polarity winding of the additional secondary winding, the time interval of the quench occurrence in two superconducting elements was shorter than the case of the additive polarity winding.

  12. Current limiting characteristics of transformer type SFCL with coupled secondary windings according to its winding direction

    International Nuclear Information System (INIS)

    Lim, Sung Hun; Han, Tae Hee

    2017-01-01

    In this paper, the current limiting characteristics of the transformer type superconducting fault current limiter (SFCL) with the two coupled secondary windings due to its winding direction were analyzed. To analyze the dependence of transient fault current limiting characteristics on the winding direction of the additional secondary winding, the fault current limiting tests of the SFCL with an additional secondary winding, wound as subtractive polarity winding and additive polarity winding, were carried out. The time interval of quench occurrence between two superconducting elements comprising the transformer type SFCL with the additional secondary winding was confirmed to be affected by the winding direction of the additional secondary winding. In case of the subtractive polarity winding of the additional secondary winding, the time interval of the quench occurrence in two superconducting elements was shorter than the case of the additive polarity winding

  13. Coupled skinny baker's maps and the Kaplan-Yorke conjecture

    Science.gov (United States)

    Gröger, Maik; Hunt, Brian R.

    2013-09-01

    The Kaplan-Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions.

  14. Coupled skinny baker's maps and the Kaplan–Yorke conjecture

    International Nuclear Information System (INIS)

    Gröger, Maik; Hunt, Brian R

    2013-01-01

    The Kaplan–Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions. (paper)

  15. Coupled ears in lizards and crocodilians

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob; Bierman, Hilary

    2016-01-01

    Lizard ears are coupled across the pharynx, and are very directional. In consequence all auditory responses should be directional, without a requirement for computation of sound source location. Crocodilian ears are connected through sinuses, and thus less tightly coupled. Coupling may improve th...... range is reviewed in the light of current theories of sound localization....

  16. Enhancement of couples' communication and dyadic coping by a self-directed approach: a randomized controlled trial.

    Science.gov (United States)

    Bodenmann, Guy; Hilpert, Peter; Nussbeck, Fridtjof W; Bradbury, Thomas N

    2014-08-01

    Although prevention of relationship distress and dissolution has potential to strengthen the well-being of partners and any children they are raising, dissemination of prevention programs can be limited because couples face many barriers to in-person participation. An alternative strategy, providing couples with an instructional DVD, is tested in the present study, in which 330 Caucasian couples (N = 660 participants; mean age: men 41.4 years, women 40.0 years) were randomly assigned to a DVD group without any further support, a DVD group with technical telephone coaching, or a wait-list control group. Couples completed questionnaires at pretest, posttest, and 3 and 6 months after completion of the intervention. Self-report measures of dyadic coping, communication quality, ineffective arguing, and relationship satisfaction were used to test whether the intervention groups improved in comparison with the control group. Women in both intervention groups increased in dyadic coping, reduced conflict behavior, and were more satisfied with their relationship 6 months after the intervention. Effects for men were mixed. Participants with poorer skills reported stronger improvement. Intimate relationships can, within limits, be positively influenced by a self-directed approach. Effective dissemination of principles underlying successful relationships can be facilitated through the use of emerging low-cost tools and technologies. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  17. A fast and automatically paired 2-D direction-of-arrival estimation with and without estimating the mutual coupling coefficients

    Science.gov (United States)

    Filik, Tansu; Tuncer, T. Engin

    2010-06-01

    A new technique is proposed for the solution of pairing problem which is observed when fast algorithms are used for two-dimensional (2-D) direction-of-arrival (DOA) estimation. Proposed method is integrated with array interpolation for efficient use of antenna elements. Two virtual arrays are generated which are positioned accordingly with respect to the real array. ESPRIT algorithm is used by employing both the real and virtual arrays. The eigenvalues of the rotational transformation matrix have the angle information at both magnitude and phase which allows the estimation of azimuth and elevation angles by using closed-form expressions. This idea is used to obtain the paired interpolated ESPRIT algorithm which can be applied for arbitrary arrays when there is no mutual coupling. When there is mutual coupling, two approaches are proposed in order to obtain 2-D paired DOA estimates. These blind methods can be applied for the array geometries which have mutual coupling matrices with a Toeplitz structure. The first approach finds the 2-D paired DOA angles without estimating the mutual coupling coefficients. The second approach estimates the coupling coefficients and iteratively improves both the coupling coefficients and the DOA estimates. It is shown that the proposed techniques solve the pairing problem for uniform circular arrays and effectively estimate the DOA angles in case of unknown mutual coupling.

  18. Money: a therapeutic tool for couples therapy.

    Science.gov (United States)

    Shapiro, Margaret

    2007-09-01

    This article addresses the therapeutic importance of discussing money at every stage of a couple's relationship, both as a concrete reality and as a metaphor for security, adequacy, competence, commitment, acceptance, and acknowledgment in a relationship. I will present a developmental schema looking at financial issues that couples confront at various stages in the adult life cycle and how these affect and reflect relationship problems. The article also presents a money questionnaire as a useful tool for exploring family-of-origin financial history, affect, and behavior.

  19. Synchronization of coupled different chaotic FitzHugh-Nagumo neurons with unknown parameters under communication-direction-dependent coupling.

    Science.gov (United States)

    Iqbal, Muhammad; Rehan, Muhammad; Khaliq, Abdul; Saeed-ur-Rehman; Hong, Keum-Shik

    2014-01-01

    This paper investigates the chaotic behavior and synchronization of two different coupled chaotic FitzHugh-Nagumo (FHN) neurons with unknown parameters under external electrical stimulation (EES). The coupled FHN neurons of different parameters admit unidirectional and bidirectional gap junctions in the medium between them. Dynamical properties, such as the increase in synchronization error as a consequence of the deviation of neuronal parameters for unlike neurons, the effect of difference in coupling strengths caused by the unidirectional gap junctions, and the impact of large time-delay due to separation of neurons, are studied in exploring the behavior of the coupled system. A novel integral-based nonlinear adaptive control scheme, to cope with the infeasibility of the recovery variable, for synchronization of two coupled delayed chaotic FHN neurons of different and unknown parameters under uncertain EES is derived. Further, to guarantee robust synchronization of different neurons against disturbances, the proposed control methodology is modified to achieve the uniformly ultimately bounded synchronization. The parametric estimation errors can be reduced by selecting suitable control parameters. The effectiveness of the proposed control scheme is illustrated via numerical simulations.

  20. Astrocytes take the stage in a tale of signaling-metabolism coupling

    DEFF Research Database (Denmark)

    Bak, Lasse K

    2017-01-01

    Astrocytes are crucial cells in the brain that are intimately coupled with neuronal metabolism. A new paper from San Martín et al. provides evidence that physiological levels of the gaseous signal molecule NO can rapidly and reversibly increase astrocyte metabolism of glucose and production...... of lactate. A proposed neurological coupling-from the potential source of NO, endothelial cells, to the potential beneficiary from the lactate, neurons-prompts new questions regarding the controversial role of lactate in the brain....

  1. Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

    Science.gov (United States)

    Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

    2018-05-01

    This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

  2. MgB2 magnetometer with a directly coupled pick-up loop

    Science.gov (United States)

    Portesi, C.; Mijatovic, D.; Veldhuis, D.; Brinkman, A.; Monticone, E.; Gonnelli, R. S.

    2006-05-01

    In this work, we show the results obtained in the fabrication and characterization of an MgB2 magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which incorporates two nanobridges as weak links in a superconducting loop. The nanobridges were realized by focused ion beam milling; they were 240 nm wide and had a critical current density of 107 A cm-2. The magnetometer was characterized at different temperatures and also measurements of the noise levels have been performed. The device shows Josephson quantum interference up to 20 K and the calculated effective area at low temperatures was 0.24 mm2. The transport properties of the magnetometer allow determining fundamental materials properties of the MgB2 thin films, such as the penetration depth.

  3. Synchronization of Coupled Different Chaotic FitzHugh-Nagumo Neurons with Unknown Parameters under Communication-Direction-Dependent Coupling

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2014-01-01

    Full Text Available This paper investigates the chaotic behavior and synchronization of two different coupled chaotic FitzHugh-Nagumo (FHN neurons with unknown parameters under external electrical stimulation (EES. The coupled FHN neurons of different parameters admit unidirectional and bidirectional gap junctions in the medium between them. Dynamical properties, such as the increase in synchronization error as a consequence of the deviation of neuronal parameters for unlike neurons, the effect of difference in coupling strengths caused by the unidirectional gap junctions, and the impact of large time-delay due to separation of neurons, are studied in exploring the behavior of the coupled system. A novel integral-based nonlinear adaptive control scheme, to cope with the infeasibility of the recovery variable, for synchronization of two coupled delayed chaotic FHN neurons of different and unknown parameters under uncertain EES is derived. Further, to guarantee robust synchronization of different neurons against disturbances, the proposed control methodology is modified to achieve the uniformly ultimately bounded synchronization. The parametric estimation errors can be reduced by selecting suitable control parameters. The effectiveness of the proposed control scheme is illustrated via numerical simulations.

  4. Effect of Group Cognitive Behavioral Couples Therapy on Couple Burnout and Divorce Tendency in Couples

    Directory of Open Access Journals (Sweden)

    M Mohammadi

    2017-02-01

    .01. According to the posttest scores of the experiment control groups for these two variables, it was recognized that the cognitive behavioral couple therapy has led to reduction in couple burnout and divorce tendency among the couples of the experiment group in comparison to the control group in the posttest stage.    Conclusion: The research findings indicate that the cognitive behavioral couple therapy model can reduce marital problems, and using this couple therapy approach is recommended for working with the couples involved in marital problems with divorce demand.  

  5. Direct Observation of Field and Temperature Induced Domain Replication in Dipolar Coupled Perpendicular Anisotropy Films

    Energy Technology Data Exchange (ETDEWEB)

    Hauet, T.; Gunther, C.M.; Pfau, B.; Eisebitt, S.; Fischer, P.; Rick, R. L.; Thiele, J.-U.; Hellwig, O.; Schabes, M.E.

    2007-07-01

    Dipolar interactions in a soft/Pd/hard [CoNi/Pd]{sub 30}/Pd/[Co/Pd]{sub 20} multilayer system, where a thick Pd layer between two ferromagnetic units prevents direct exchange coupling, are directly revealed by combining magnetometry and state-of-the-art layer resolving soft x-ray imaging techniques with sub-100-nm spatial resolution. The domains forming in the soft layer during external magnetic field reversal are found to match the domains previously trapped in the hard layer. The low Curie temperature of the soft layer allows varying its intrinsic parameters via temperature and thus studying the competition with dipolar fields due to the domains in the hard layer. Micromagnetic simulations elucidate the role of [CoNi/Pd] magnetization, exchange, and anisotropy in the duplication process. Finally, thermally driven domain replication in remanence during temperature cycling is demonstrated.

  6. Hydrothermal–galvanic couple synthesis of directionally oriented BaTiO3 thin films on TiN-coated substrates

    International Nuclear Information System (INIS)

    Yang, Chia-Jung; Tsai, Di-You; Chan, Pei-Hsuan; Wu, Chu-Tsun; Lu, Fu-Hsing

    2013-01-01

    BaTiO 3 films were synthesized on TiN-coated Si substrate below 100 °C by a hydrothermal–galvanic couple technique in barium contained alkaline solutions. X-ray diffraction and electron backscatter diffraction results show that the BaTiO 3 thin films were directionally oriented grown on the TiN/Si substrates, i.e., (111) BaTiO 3 over (111) TiN. The surface morphologies revealed that BaTiO 3 nucleated and grew over the TiN surface with a single layer. From kinetic analyses, the growth rates of BaTiO 3 films prepared by the hydrothermal–galvanic couple technique were faster than a hydrothermal method. The galvanic effects were confirmed by investigating the induced currents and energies. The galvanic currents were generated and controlled by both the dissolution of TiN and the formation of BaTiO 3 . The output electric energies increased rapidly with the reaction time and leveled off at the full coverage of BaTiO 3 . - Highlights: • Cubic BaTiO 3 films are synthesized by a hydrothermal–galvanic couple method (HT–GC). • Growth rates of BaTiO 3 films made by HT–GC are faster than a hydrothermal method. • BaTiO 3 films are directionally oriented grown on the TiN/Si substrates. • Galvanic currents are controlled by dissolution of TiN and formation of BaTiO 3

  7. Phase-field simulation of peritectic solidification closely coupled with directional solidification experiments in an Al-36 wt% Ni alloy

    International Nuclear Information System (INIS)

    Siquieri, R; Emmerich, H; Doernberg, E; Schmid-Fetzer, R

    2009-01-01

    In this work we present experimental and theoretical investigations of the directional solidification of Al-36 wt% Ni alloy. A phase-field approach (Folch and Plapp 2005 Phys. Rev. E 72 011602) is coupled with the CALPHAD (calculation of phase diagrams) method to be able to simulate directional solidification of Al-Ni alloy including the peritectic phase Al 3 Ni. The model approach is calibrated by systematic comparison to microstructures grown under controlled conditions in directional solidification experiments. To illustrate the efficiency of the model it is employed to investigate the effect of temperature gradient on the microstructure evolution of Al-36 wt% Ni during solidification.

  8. Direct coupling of electromembrane extraction to mass spectrometry – Advancing the probe functionality toward measurements of zwitterionic drug metabolites

    DEFF Research Database (Denmark)

    Kige Rye, Torstein; Fuchs, David; Pedersen-Bjergaard, Stig

    2017-01-01

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow......-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min-1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes......, the system can potentially be used for direct analysis of various kinds of chemical reactions that have to be run at pH conditions unfavorable for direct analyte extractions....

  9. Disturbance estimation and compensation for planar motors on the long-stroke stage of a wafer stage

    Directory of Open Access Journals (Sweden)

    Bizhong Xia

    2015-04-01

    Full Text Available This article presents a data-based method to estimate and compensate low-frequency disturbance in planar motors on the long-stroke stage of a wafer stage, which is a typical multiple-input multiple-output system. First, a data-based method is introduced to decouple the multiple-input multiple-output system into multi-single-input single-output system, which is crucial for the design of controller and the correction of disturbance estimation in the scanning direction. Second, dominant low-frequency disturbances in the long-stroke stage are analyzed. Third, estimation and compensation method under moving condition is proposed. The compensation method is based on three feedforward tables, and the tables are indexed by trajectory parameters, including velocity and position instead of time in the iterative learning control method. Finally, experiments are performed on the long-stroke stage of a wafer stage to verify the proposed method. Experimental results show that the proposed method can effectively improve the servo performance by reducing the tracking errors by nearly 1/2 in the forward direction and 1/3 in the backward direction and lowering error difference between the forward and backward directions from 5.1 to 1.2 µm.

  10. Kinetics of the direct sulfation of limestone at the initial stage of crystal growth of the solid product

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2011-01-01

    The direct sulfation of limestone was studied in a quartz bench scale fixed‐bed reactor with the technique of data deconvolution. The obtained results show that the direct sulfation of limestone has a two‐period kinetic behavior: a short initial sulfation period with high but fast decreasing...... such as SO2, O2, and CO2 and the temperature. The sulfation process in the initial stage of the period with product crystal growth can be described by the combination of the sulfation reaction at the gas–solid interface, diffusion of the product ions toward the product crystal grains, diffusion of carbonate...

  11. Study of ablation and implosion stages in wire arrays using coupled ultraviolet and X-ray probing diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, A. A.; Ivanov, V. V.; Astanovitskiy, A. L.; Wiewior, P. P.; Chalyy, O. [University of Nevada Reno, Reno, Nevada 89557 (United States); Papp, D. [University of Nevada Reno, Reno, Nevada 89557 (United States); ELI-ALPS, ELI-Hu Nkft., H-6720 Szeged (Hungary)

    2015-11-15

    Star and cylindrical wire arrays were studied using laser probing and X-ray radiography at the 1-MA Zebra pulse power generator at the University of Nevada, Reno. The Leopard laser provided backlighting, producing a laser plasma from a Si target which emitted an X-ray probing pulse at the wavelength of 6.65 Å. A spherically bent quartz crystal imaged the backlit wires onto X-ray film. Laser probing diagnostics at the wavelength of 266 nm included a 3-channel polarimeter for Faraday rotation diagnostic and two-frame laser interferometry with two shearing interferometers to study the evolution of the plasma electron density at the ablation and implosion stages. Dynamics of the plasma density profile in Al wire arrays at the ablation stage were directly studied with interferometry, and expansion of wire cores was measured with X-ray radiography. The magnetic field in the imploding plasma was measured with the Faraday rotation diagnostic, and current was reconstructed.

  12. An Integrative Biosensor Based on Contra-Directional Coupling Two-dimensional Photonic Crystal Waveguides

    International Nuclear Information System (INIS)

    Xiao-Yu, Mao; Di-Bi, Yao; Ling-Yun, Zhao; Yi-Dong, Huang; Wei, Zhang; Jiang-De, Peng

    2008-01-01

    We propose an integrative biochemical sensor utilizing the dip in the transmission spectrum of a normal single-line defect photonic crystal (PC) waveguide, which has a contra-directional coupling with another PC waveguide. When the air holes in the PC slab are filled with a liquid analyte with different refractive indices, the dip has a wavelength shift By detecting the output power variation at a certain fixed wavelength, a sensitivity of 1.2 × 10 −4 is feasible. This structure is easy for integration due to its plane waveguide structure and omissible pump source. In addition, high signal to noise ratio can be expected because signal transmits via a normal single-line defect PC waveguide instead of the PC hole area or analyte

  13. Actual characteristics study on HTR-10GT coupling with direct gas turbine cycle

    International Nuclear Information System (INIS)

    Peng Xuechuang; Zhu Shutang; Wang Jie

    2005-01-01

    HTR-10GT is a testing project coupling the reactor HTR-10 with direct gas turbine cycle. Its thermal cycle can be taken as a closed, recuperated and inter-cooled Brayton cycle. The present study is focused on the thermal cycle performance of HTR-10GT under practical conditions of leakage, pressure losses, etc.. Through thermodynamic analysis, the expression of cycle efficiency for actual thermal cycle is derived. By establishing a physical model with friction loss and leakage, a set of governing equation are constructed based on some reasonable assumptions. The results of actual cycle efficiency have been calculated for different leakage amount at different locations while the effects of leakage under different power level have also been calculated and analyzed. (authors)

  14. Compact and broadband directional coupling and demultiplexing in dielectric-loaded surface plasmon polariton waveguides based on the multimode interference effect

    DEFF Research Database (Denmark)

    Zhu, Zhihong; García Ortíz, César Eduardo; Han, Zhanghua

    2013-01-01

    We theoretically, numerically, and experimentally demonstrate that a directional coupling function can be realized with a wide bandwidth (greater than 200 nm) in dielectric-loaded surface plasmon polariton waveguides based on the multimode interference effect. The functional size of the structure...

  15. Coherence Phenomena in Coupled Optical Resonators

    Science.gov (United States)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  16. Multi-path interferometric Josephson directional amplifier for qubit readout

    Science.gov (United States)

    Abdo, Baleegh; Bronn, Nicholas T.; Jinka, Oblesh; Olivadese, Salvatore; Brink, Markus; Chow, Jerry M.

    2018-04-01

    We realize and characterize a quantum-limited, directional Josephson amplifier suitable for qubit readout. The device consists of two nondegenerate, three-wave-mixing amplifiers that are coupled together in an interferometric scheme, embedded in a printed circuit board. Nonreciprocity is generated by applying a phase gradient between the same-frequency pumps feeding the device, which plays the role of the magnetic field in a Faraday medium. Directional amplification and reflection-gain elimination are induced via wave interference between multiple paths in the system. We measure and discuss the main figures of merit of the device and show that the experimental results are in good agreement with theory. An improved version of this directional amplifier is expected to eliminate the need for bulky, off-chip isolation stages that generally separate quantum systems and preamplifiers in high-fidelity, quantum-nondemolition measurement setups.

  17. Direct lifts of coupled cell networks

    Science.gov (United States)

    Dias, A. P. S.; Moreira, C. S.

    2018-04-01

    In networks of dynamical systems, there are spaces defined in terms of equalities of cell coordinates which are flow-invariant under any dynamical system that has a form consistent with the given underlying network structure—the network synchrony subspaces. Given a network and one of its synchrony subspaces, any system with a form consistent with the network, restricted to the synchrony subspace, defines a new system which is consistent with a smaller network, called the quotient network of the original network by the synchrony subspace. Moreover, any system associated with the quotient can be interpreted as the restriction to the synchrony subspace of a system associated with the original network. We call the larger network a lift of the smaller network, and a lift can be interpreted as a result of the cellular splitting of the smaller network. In this paper, we address the question of the uniqueness in this lifting process in terms of the networks’ topologies. A lift G of a given network Q is said to be direct when there are no intermediate lifts of Q between them. We provide necessary and sufficient conditions for a lift of a general network to be direct. Our results characterize direct lifts using the subnetworks of all splitting cells of Q and of all split cells of G. We show that G is a direct lift of Q if and only if either the split subnetwork is a direct lift or consists of two copies of the splitting subnetwork. These results are then applied to the class of regular uniform networks and to the special classes of ring networks and acyclic networks. We also illustrate that one of the applications of our results is to the lifting bifurcation problem.

  18. First-principles approach to the dynamic magnetoelectric couplings for the non-reciprocal directional dichroism in BiFeO3

    International Nuclear Information System (INIS)

    Lee, Jun Hee; Fishman, Randy S; Kézsmáki, István

    2016-01-01

    Due to the complicated magnetic and crystallographic structures of BiFeO 3 , its magnetoelectric (ME) couplings and microscopic model Hamiltonian remain poorly understood. By employing a first-principles approach, we uncover all possible ME couplings associated with the spin-current (SC) and exchange-striction (ES) polarizations, and construct an appropriate Hamiltonian for the long-range spin-cycloid in BiFeO 3 . First-principles calculations are used to understand the microscopic origins of the ME couplings. We find that inversion symmetries broken by ferroelectric and antiferroelectric distortions induce the SC and the ES polarizations, which cooperatively produce the dynamic ME effects in BiFeO 3 . A model motivated by first principles reproduces the absorption difference of counter-propagating light beams called non-reciprocal directional dichroism. The current paper focuses on the spin-driven (SD) polarizations produced by a dynamic electric field, i.e. the dynamic ME couplings. Due to the inertial properties of Fe, the dynamic SD polarizations differ significantly from the static SD polarizations. Our systematic approach can be generally applied to any multiferroic material, laying the foundation for revealing hidden ME couplings on the atomic scale and for exploiting optical ME effects in the next generation of technological devices such as optical diodes. (paper)

  19. Direct coupling of polymer-based microchip electrophoresis to online MALDI-MS using a rotating ball inlet.

    Science.gov (United States)

    Musyimi, Harrison K; Guy, Jason; Narcisse, Damien A; Soper, Steven A; Murray, Kermit K

    2005-12-01

    We report on the coupling of a polymer-based microfluidic chip to a MALDI-TOF MS using a rotating ball interface. The microfluidic chips were fabricated by micromilling a mold insert into a brass plate, which was then used for replicating polymer microparts via hot embossing. Assembly of the chip was accomplished by thermally annealing a cover slip to the embossed substrate to enclose the channels. The linear separation channel was 50 microm wide, 100 microm deep, and possessed an 8 cm effective length separation channel with a double-T injector (V(inj) = 10 nL). The exit of the separation channel was machined to allow direct contact deposition of effluent onto a specially constructed rotating ball inlet to the mass spectrometer. Matrix addition was accomplished in-line on the surface of the ball. The coupling utilized the ball as the cathode transfer electrode to transport sample into the vacuum for desorption with a 355 nm Nd:YAG laser and analyzed on a TOF mass spectrometer. The ball was cleaned online after every rotation. The ability to couple poly(methylmethacrylate) microchip electrophoresis devices for the separation of peptides and peptide fragments produced from a protein digest with subsequent online MALDI MS detection was demonstrated.

  20. Coupling of In Vitro Bioassays with Planar Chromatography in Effect-Directed Analysis.

    Science.gov (United States)

    Weiss, Stefan C; Egetenmeyer, Nicole; Schulz, Wolfgang

    Modern analytical test methods increasingly detect anthropogenic organic substances and their transformation products in water samples and in the environment. The presence of these compounds might pose a risk to the aquatic environment. To determine a possible (eco)toxicological risk, aquatic samples are tested using various bioassays, including sub-organismic assays such as the luminescent bacteria inhibition test, the acetylcholinesterase inhibition test, and the umu-test. The effect-directed analysis (EDA) combines physicochemical separation methods with biological (in vitro) tests. High-performance thin-layer chromatography (HPTLC) has proved to be particularly well suited for the separation of organic compounds and the subsequent analysis of effects by the application of the biotests directly on the surface of the HPTLC plate. The advantage of using HPTLC in comparison to high-performance liquid chromatography (HPLC) for EDA is that the solvent which is used as a mobile phase during chromatography is completely evaporated after the separation and therefore can no longer influence the applied bioassays.A prioritization during the complex identification process can be achieved when observed effects are associated with the separated zones in HPTLC. This increases the probability of identifying the substance responsible for an adverse effect from the multitude of organic trace substances in environmental samples. Furthermore, by comparing the pattern of biological effects of a separated sample, it is possible to track and assess changes in biological activity over time, over space, or in the course of a process, even without identifying the substance. HPTLC has already been coupled with various bioassays.Because HPTLC is a very flexible system, various detection techniques can be used and combined. In addition to the UV/Vis absorption and fluorescence measurements, TLC can also be coupled with a mass spectrometer (MS) for compound identification. In addition

  1. Total water production capacity inversion phenomenon in multi-stage direct contact membrane distillation: A theoretical study

    KAUST Repository

    Lee, Jung Gil

    2017-09-09

    The low thermal efficiency and low water production are among the major challenges that prevent membrane distillation (MD) process from being commercialized. In an effort to design an efficient multi-stage direct contact MD (DCMD) unit through mathematical simulation, a new phenomenon that we refer to as total water production capacity inversion (WPI) has been detected. It is represented by a decrease in the total water production beyond a number of stages or a certain module length. WPI phenomenon, which was confirmed by using two different mathematical models validated experimentally, was found to take place due to the decrease in water vapor flux across the membrane as well as the increase in heat loss by conduction as the membrane length increases. Therefore, WPI should be considered as a critical MD design-criterion, especially for large scale units. Investigations conducted for a simulated multi-stage DCMD process showed that inlet feed and permeate temperatures difference, feed and permeate flow rates, and feed salinity have different effects on WPI. The number of stages (or module length at constant width) that leads to a maximum water production has been determined for different operating parameters. Decreasing inlet feed and permeate temperatures difference, or inlet feed and permeate flow rates and increasing inlet feed temperature at constant temperature difference or inlet feed salinity cause the WPI to take place at lower number of stages. Even though the feed salinity affects negligibly the mean permeate flux, it was clearly shown that it can affect WPI. The results presented herein unveil a hidden phenomenon that is likely to occur during process scale-up procedures and should be considered by process engineers for a proper choice of system design and operating conditions.

  2. Direct transitions from high-K isomers to low-K bands -- {gamma} softness or coriolis coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R.; Narimatsu, Kanako; Ohtsubo, Shin-Ichi [Kyushu Univ., Fukuoka (Japan)] [and others

    1996-12-31

    Recent measurements of direct transitions from high-K isomers to low-K bands reveal severe break-down of the K-selection rule and pose the problem of how to understand the mechanism of such K-violation. The authors recent systematic calculations by using a simple {gamma}-tunneling model reproduced many of the observed hindrances, indicating the importance of the {gamma} softness. However, there are some data which cannot be explained in terms of the {gamma}-degree of freedom. In this talk, the authors also discuss the results of conventional Coriolis coupling calculations, which is considered to be another important mechanism.

  3. Improved formalism for precision Higgs coupling fits

    Science.gov (United States)

    Barklow, Tim; Fujii, Keisuke; Jung, Sunghoon; Karl, Robert; List, Jenny; Ogawa, Tomohisa; Peskin, Michael E.; Tian, Junping

    2018-03-01

    Future e+e- colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e+e- data, based on the effective field theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e+e- colliders.

  4. Improved formalism for precision Higgs coupling fits

    International Nuclear Information System (INIS)

    Barklow, Tim; Peskin, Michael E.; Jung, Sunghoon; Tian, Junping

    2017-08-01

    Future e + e - colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e + e - data, based on the Effective Field Theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e + e - colliders.

  5. Direct observation of magnon-phonon coupling in yttrium iron garnet

    Science.gov (United States)

    Man, Haoran; Shi, Zhong; Xu, Guangyong; Xu, Yadong; Chen, Xi; Sullivan, Sean; Zhou, Jianshi; Xia, Ke; Shi, Jing; Dai, Pengcheng

    2017-09-01

    The magnetic insulator yttrium iron garnet (YIG) with a ferrimagnetic transition temperature of ˜560 K has been widely used in microwave and spintronic devices. Anomalous features in spin Seeback effect (SSE) voltages have been observed in Pt/YIG and attributed to magnon-phonon coupling. Here, we use inelastic neutron scattering to map out low-energy spin waves and acoustic phonons of YIG at 100 K as a function of increasing magnetic field. By comparing the zero and 9.1 T data, we find that instead of splitting and opening up gaps at the spin wave and acoustic phonon dispersion intersecting points, magnon-phonon coupling in YIG enhances the hybridized scattering intensity. These results are different from expectations of conventional spin-lattice coupling, calling for different paradigms to understand the scattering process of magnon-phonon interactions and the resulting magnon polarons.

  6. Neurovascular coupling protects neurons against hypoxic injury via inhibition of potassium currents by generation of nitric oxide in direct neuron and endothelium cocultures.

    Science.gov (United States)

    Wu, Kun-Wei; Kou, Zeng-Wei; Mo, Jia-Lin; Deng, Xu-Xu; Sun, Feng-Yan

    2016-10-15

    This study examined the effect of neuron-endothelial coupling on the survival of neurons after ischemia and the possible mechanism underlying that effect. Whole-cell patch-clamp experiments were performed on cortical neurons cultured alone or directly cocultured with brain microvascular endothelial cells (BMEC). Propidium iodide (PI) and NeuN staining were performed to examine neuronal death following oxygen and glucose deprivation (OGD). We found that the neuronal transient outward potassium currents (I A ) decreased in the coculture system, whereas the outward delayed-rectifier potassium currents (I K ) did not. Sodium nitroprusside, a NO donor, enhanced BMEC-induced I A inhibition and nitro-l-arginine methylester, a NOS inhibitor, partially prevented this inhibition. Moreover, the neurons directly cocultured with BMEC showed more resistance to OGD-induced injury compared with the neurons cultured alone, and that neuroprotective effect was abolished by treatment with NS5806, an activator of the I A . These results indicate that vascular endothelial cells assist neurons to prevent hypoxic injury via inhibiting neuronal I A by production of NO in the direct neuron-BMEC coculture system. These results further provide direct evidence of functional coupling between neurons and vascular endothelial cells. This study clearly demonstrates that vascular endothelial cells play beneficial roles in the pathophysiological processes of neurons after hypoxic injury, suggesting that the improvement of neurovascular coupling or functional remodeling may become an important therapeutic target for preventing brain injury. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Coupling methods for multistage sampling

    OpenAIRE

    Chauvet, Guillaume

    2015-01-01

    Multistage sampling is commonly used for household surveys when there exists no sampling frame, or when the population is scattered over a wide area. Multistage sampling usually introduces a complex dependence in the selection of the final units, which makes asymptotic results quite difficult to prove. In this work, we consider multistage sampling with simple random without replacement sampling at the first stage, and with an arbitrary sampling design for further stages. We consider coupling ...

  8. Development of a compact, fiber-coupled, six degree-of-freedom measurement system for precision linear stage metrology

    International Nuclear Information System (INIS)

    Yu, Xiangzhi; Gillmer, Steven R.; Woody, Shane C.; Ellis, Jonathan D.

    2016-01-01

    A compact, fiber-coupled, six degree-of-freedom measurement system which enables fast, accurate calibration, and error mapping of precision linear stages is presented. The novel design has the advantages of simplicity, compactness, and relatively low cost. This proposed sensor can simultaneously measure displacement, two straightness errors, and changes in pitch, yaw, and roll using a single optical beam traveling between the measurement system and a small target. The optical configuration of the system and the working principle for all degrees-of-freedom are presented along with the influence and compensation of crosstalk motions in roll and straightness measurements. Several comparison experiments are conducted to investigate the feasibility and performance of the proposed system in each degree-of-freedom independently. Comparison experiments to a commercial interferometer demonstrate error standard deviations of 0.33 μm in straightness, 0.14 μrad in pitch, 0.44 μradin yaw, and 45.8 μrad in roll.

  9. Development of a compact, fiber-coupled, six degree-of-freedom measurement system for precision linear stage metrology

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiangzhi, E-mail: xiangzhi.yu@rochester.edu; Gillmer, Steven R. [Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); Woody, Shane C. [InSituTec Incorporated, 7140 Weddington Road, Concord, North Carolina 28027 (United States); Ellis, Jonathan D. [Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); The Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

    2016-06-15

    A compact, fiber-coupled, six degree-of-freedom measurement system which enables fast, accurate calibration, and error mapping of precision linear stages is presented. The novel design has the advantages of simplicity, compactness, and relatively low cost. This proposed sensor can simultaneously measure displacement, two straightness errors, and changes in pitch, yaw, and roll using a single optical beam traveling between the measurement system and a small target. The optical configuration of the system and the working principle for all degrees-of-freedom are presented along with the influence and compensation of crosstalk motions in roll and straightness measurements. Several comparison experiments are conducted to investigate the feasibility and performance of the proposed system in each degree-of-freedom independently. Comparison experiments to a commercial interferometer demonstrate error standard deviations of 0.33 μm in straightness, 0.14 μrad in pitch, 0.44 μradin yaw, and 45.8 μrad in roll.

  10. Improved formalism for precision Higgs coupling fits

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, Tim; Peskin, Michael E. [Stanford Univ., Menlo Park, CA (United States). Stanford Linear Accelerator Center; Fujii, Keisuke; Ogawa, Tomohisa [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Jung, Sunghoon [Stanford Univ., Menlo Park, CA (United States). Stanford Linear Accelerator Center; Seoul National Univ. (Korea, Republic of). Dept. of Physics and Astronomy; Karl, Robert; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Tian, Junping [Tokyo Univ. (Japan). International Center for Elementary Particle Physics (ICEPP)

    2017-08-15

    Future e{sup +}e{sup -} colliders give the promise of model-independent determinations of the couplings of the Higgs boson. In this paper, we present an improved formalism for extracting Higgs boson couplings from e{sup +}e{sup -} data, based on the Effective Field Theory description of corrections to the Standard Model. We apply this formalism to give projections of Higgs coupling accuracies for stages of the International Linear Collider and for other proposed e{sup +}e{sup -} colliders.

  11. Directional radiation pattern in structural-acoustic coupled system

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-07-01

    In this paper we demonstrate the possibility of designing a radiator using structural-acoustic interaction by predicting the pressure distribution and radiation pattern of a structural-acoustic coupling system that is composed by a wall and two spaces. If a wall separates spaces, then the wall's role in transporting the acoustic characteristics of the spaces is important. The spaces can be categorized as bounded finite space and unbounded infinite space. The wall considered in this study composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. This rather hypothetical circumstance is selected to study the general coupling problem between the finite and infinite acoustic domains. We developed an equation that predicts the energy distribution and energy flow in the two spaces separated by a wall, and its computational examples are presented. Three typical radiation patterns that include steered, focused, and omnidirected are presented. A designed radiation pattern is also presented by using the optimal design algorithm.

  12. One-dimensional simulation of a stirling three-stage pulse-tube refrigerator

    NARCIS (Netherlands)

    Etaati, M.A.; Mattheij, R.M.M.; Tijsseling, A.S.; Waele, de A.T.A.M.

    2009-01-01

    A one-dimensional mathematical model is derived for a three-stage pulse-tube refrigerator (PTR) that is based on the conservation laws and the ideal gas law. The three-stage PTR is regarded as three separate single-stage PTRs that are coupled via proper junction conditions. At the junctions there

  13. One-dimensional simulation of a Stirling three-stage pulse-tube refrigerator

    NARCIS (Netherlands)

    Etaati, M.A.; Mattheij, R.M.M.; Tijsseling, A.S.; Waele, de A.T.A.M.

    2009-01-01

    A one-dimensional mathematical model is derived for a three-stage pulse-tube refrigerator (PTR) that is based on the conservation laws and the ideal gas law. The three-stage PTR is regarded as three separate single-stage PTRs that are coupled via proper junction conditions. At the junctions there

  14. A Preliminary Direct Measurement of the Parity-Violating Coupling of the Z{sup 0} to Strange Quarks, A{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Muller, David

    1999-07-09

    We present an updated direct measurement of the parity-violating coupling of the Z{sup 0} to strange quarks, A{sub s}, derived from the full SLD data sample of approximately 550,000 hadronic decays of Z{sup 0} bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1998. Z{sup 0} {r_arrow} s{bar s} events are tagged by the presence in each event hemisphere of a high-momentum K{sup {+-}}, K{sub s} or {Lambda}{sup 0}/{bar {Lambda}}{sup 0} identified using the Cherenkov Ring Imaging Detector and/or a mass tag. The CCD vertex detector is used to suppress the background from heavy-flavor events. The strangeness of the tagged particle is used to sign the event thrust axis in the direction of the initial s quark. The coupling A{sub s} is obtained directly from a measurement of the left-right-forward-backward production asymmetry in polar angle of the tagged s quark. The background from u{bar u} and d{bar d} events is measured from the data, as is the analyzing power of the method for s{bar s} events. We measure: A{sub s} = 0.85 {+-} 0.06(stat.) {+-} 0.07(syst.)(preliminary).

  15. Directional patterns of cross frequency phase and amplitude coupling within the resting state mimic patterns of fMRI functional connectivity

    Science.gov (United States)

    Weaver, Kurt E.; Wander, Jeremiah D.; Ko, Andrew L.; Casimo, Kaitlyn; Grabowski, Thomas J.; Ojemann, Jeffrey G.; Darvas, Felix

    2016-01-01

    Functional imaging investigations into the brain's resting state interactions have yielded a wealth of insight into the intrinsic and dynamic neural architecture supporting cognition and behavior. Electrophysiological studies however have highlighted the fact that synchrony across large-scale cortical systems is composed of spontaneous interactions occurring at timescales beyond the traditional resolution of fMRI, a feature that limits the capacity of fMRI to draw inference on the true directional relationship between network nodes. To approach the question of directionality in resting state signals, we recorded resting state functional MRI (rsfMRI) and electrocorticography (ECoG) from four human subjects undergoing invasive epilepsy monitoring. Using a seed-point based approach, we employed phase-amplitude coupling (PAC) and biPhase Locking Values (bPLV), two measures of cross-frequency coupling (CFC) to explore both outgoing and incoming connections between the seed and all non-seed, site electrodes. We observed robust PAC between a wide range of low-frequency phase and high frequency amplitude estimates. However, significant bPLV, a CFC measure of phase-phase synchrony, was only observed at specific narrow low and high frequency bandwidths. Furthermore, the spatial patterns of outgoing PAC connectivity were most closely associated with the rsfMRI connectivity maps. Our results support the hypothesis that PAC is relatively ubiquitous phenomenon serving as a mechanism for coordinating high-frequency amplitudes across distant neuronal assemblies even in absence of overt task structure. Additionally, we demonstrate that the spatial distribution of a seed-point rsfMRI sensorimotor network is strikingly similar to specific patterns of directional PAC. Specifically, the high frequency activities of distal patches of cortex owning membership in a rsfMRI sensorimotor network were most likely to be entrained to the phase of a low frequency rhythm engendered from the

  16. Direct solar energy conversion and storage through coupling between photoelectrochemical and ferroelectric effects

    Directory of Open Access Journals (Sweden)

    Chi-Wei Lo

    2011-12-01

    Full Text Available Harvesting and storing solar energy has become more and more important. Current solid-state photovoltaic cells and conventional photoelectrochemical cells are not capable of directly storing the converted energy, which has to be facilitated by connecting to external storing devices. We demonstrate a device architecture that can convert and store solar energy in the electrical form within an intrinsically single structure. Mobile charge is internally stored, based on the coupling between photoelectrochemical and ferroelectric effects. The tested device architecture can be photo-charged under 1000 W/m2 of white light to an open-circuit voltage of 0.47V with a capacity of 37.62 mC/cm2. After removal of the light source, the mobile charge stored lasts more than 8 hours, and the open-circuit output voltage lasts more than 24 hours.

  17. Improvement of directionality and sound-localization by internal ear coupling in barn owls

    DEFF Research Database (Denmark)

    Wagner, Hermann; Christensen-Dalsgaard, Jakob; Kettler, Lutz

    Mark Konishi was one of the first to quantify sound-localization capabilities in barn owls. He showed that frequencies between 3 and 10 kHz underlie precise sound localization in these birds, and that they derive spatial information from processing interaural time and interaural level differences....... However, despite intensive research during the last 40 years it is still unclear whether and how internal ear coupling contributes to sound localization in the barn owl. Here we investigated ear directionality in anesthetized birds with the help of laser vibrometry. Care was taken that anesthesia...... time difference in the low-frequency range, barn owls hesitate to approach prey or turn their heads when only low-frequency auditory information is present in a stimulus they receive. Thus, the barn-owl's sound localization system seems to be adapted to work best in frequency ranges where interaural...

  18. 37 GHz Direct-Modulation Bandwidth of Multi-Section InGaAsP/InP DBR-Laser with weakly coupled active grating section

    DEFF Research Database (Denmark)

    Kaiser, W.; Bach, L.; Reithmaier, J. P.

    2003-01-01

    37 GHz direct-modulation bandwidth could be obtained by a multi-section design with an integrated weakly coupled DBR grating. The laser shows side mode suppression ratios of 45 dB and output powers exceeding 20 mW....

  19. Simulation studies on the effect of positioning tolerances on optical coupling efficiency

    Science.gov (United States)

    Pamidighantam, Ramana V.; Yeo, Yongkee; Sudharsanam, Krishnamachari; Lee, Sik Pong; Iyer, Mahadevan K.

    2002-08-01

    The development of Optoelectronic components for communications is converging towards access networks where device cost makes a significant impact on the market acceptance. Thus, the device design engineer needs to input assembly, fabrication and process constraints into the design at an early stage. The present study is part of a Project on Packaging of Optical Components that IME, Singapore has initiated as part of an ongoing Electronics Packaging Research Consortium with industry partnership. In the present study, the coupling of optical radiation from a laser diode to optical fiber is simulated for a fiber optic transmitter component development project. Different optical configurations based on direct coupling, spherical ball lenses, integral lensed fibers and thermally expanded fibers are created within the commercially available transmitter package space. The effect of optical element variables on the placement tolerance is analyzed and will be reported. The effect of alignment tolerances on the optical coupling is analyzed. Simulation results are presented recommending realizable alignment and placement tolerances to develop a low cost short range link distance transmitter.

  20. Correlates of Couples’ Perceived Similarity at the Initiation Stage and Currently

    Directory of Open Access Journals (Sweden)

    Susan Sprecher

    2013-12-01

    Full Text Available Although prior research (Montoya, Horton, & Kirchner, 2008 has indicated that perceived similarity is more important than actual similarity as a predictor of satisfaction and attraction, there is a lack of research on factors associated with couples’ perceptions of similarity in their relationship. In the present study, a sample of couples (both partners provided ratings of the degree to which they perceived similarity in six areas (background characteristics, attitudes and beliefs, leisure pursuits and interests, communication style, personality, and physical attributes for two stages in their relationship: currently and at the initiation stage (viewed retrospectively. The couples perceived greater similarity for the current stage of their relationship than for the beginning stage of their relationship. Factors found to be associated with perceived similarity included positive social network reactions, overlap in social networks (predictor of current perceived similarity only, perceived compatibility, and satisfaction and commitment (examined only for current perceived similarity. Of the various types of perceived similarity considered in this study, similarity in attitudes and beliefs was most consistently associated with the various predictor variables. Implications of these results for enhancing couple relationships are discussed.

  1. Design Evaluation of Wind Turbine Spline Couplings Using an Analytical Model: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Keller, J.; Wallen, R.; Errichello, R.; Halse, C.; Lambert, S.

    2015-02-01

    Articulated splines are commonly used in the planetary stage of wind turbine gearboxes for transmitting the driving torque and improving load sharing. Direct measurement of spline loads and performance is extremely challenging because of limited accessibility. This paper presents an analytical model for the analysis of articulated spline coupling designs. For a given torque and shaft misalignment, this analytical model quickly yields insights into relationships between the spline design parameters and resulting loads; bending, contact, and shear stresses; and safety factors considering various heat treatment methods. Comparisons of this analytical model against previously published computational approaches are also presented.

  2. Neuronal oscillations with non-sinusoidal morphology produce spurious phase-to-amplitude coupling and directionality.

    Directory of Open Access Journals (Sweden)

    Diego Lozano-Soldevilla

    2016-08-01

    Full Text Available Neuronal oscillations support cognitive processing. Modern views suggest that neuronal oscillations do not only reflect coordinated activity in spatially distributed networks, but also that there is interaction between the oscillations at different frequencies. For example, invasive recordings in animals and humans have found that the amplitude of fast oscillations (> 40 Hz occur non-uniformly within the phase of slower oscillations, forming the so-called cross-frequency coupling (CFC. However, the CFC patterns be influenced by features in the signal that do not relate to underlying physiological interactions. For example, CFC estimates may be sensitive to spectral correlations due to non-sinusoidal properties of the alpha band wave morphology. To investigate this issue, we performed CFC analysis using experimental and synthetic data. The former consisted in a double-blind magnetoencephalography pharmacological study in which participants received either placebo, 0.5 mg or 1.5 mg of lorazepam (LZP; GABAergic enhancer in different experimental sessions. By recording oscillatory brain activity with during rest and working memory (WM, we were able to demonstrate that posterior alpha (8 – 12 Hz phase was coupled to beta-low gamma band (20 – 45 Hz amplitude envelope during all sessions. Importantly, bicoherence values around the harmonics of the alpha frequency were similar both in magnitude and topographic distribution to the cross-frequency coherence (CFCoh values observed in the alpha-phase to beta-low gamma coupling. In addition, despite the large CFCoh we found no significant cross-frequency directionality (CFD. Critically, simulations demonstrated that a sizable part of our empirical CFCoh between alpha and beta-low gamma coupling and the lack of CFD could be explained by two-three harmonics aligned in zero phase-lag produced by the physiologically characteristic alpha asymmetry in the amplitude of the peaks relative to the troughs

  3. Warthog: A MOOSE-Based Application for the Direct Code Coupling of BISON and PROTEUS

    Energy Technology Data Exchange (ETDEWEB)

    McCaskey, Alexander J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Slattery, Stuart [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Billings, Jay Jay [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    Warthog leverages a tool known as DataTransferKit to seamlessly enable the transfer for solution data between disparate frameworks and mesh formats. To end, we demonstrate tests for the direct software coupling of BISON and PROTEUS using Warthog, and discuss current impediments and solutions to the construction of physically realistic input models for this coupled BISON-PROTEUS system.

  4. Two-stage high frequency pulse tube refrigerator with base temperature below 10 K

    Science.gov (United States)

    Chen, Liubiao; Wu, Xianlin; Liu, Sixue; Zhu, Xiaoshuang; Pan, Changzhao; Guo, Jia; Zhou, Yuan; Wang, Junjie

    2017-12-01

    This paper introduces our recent experimental results of pulse tube refrigerator driven by linear compressor. The working frequency is 23-30 Hz, which is much higher than the G-M type cooler (the developed cryocooler will be called high frequency pulse tube refrigerator in this paper). To achieve a temperature below 10 K, two types of two-stage configuration, gas coupled and thermal coupled, have been designed, built and tested. At present, both types can achieve a no-load temperature below 10 K by using only one compressor. As to gas-coupled HPTR, the second stage can achieve a cooling power of 16 mW/10K when the first stage applied a 400 mW heat load at 60 K with a total input power of 400 W. As to thermal-coupled HPTR, the designed cooling power of the first stage is 10W/80K, and then the temperature of the second stage can get a temperature below 10 K with a total input power of 300 W. In the current preliminary experiment, liquid nitrogen is used to replace the first coaxial configuration as the precooling stage, and a no-load temperature 9.6 K can be achieved with a stainless steel mesh regenerator. Using Er3Ni sphere with a diameter about 50-60 micron, the simulation results show it is possible to achieve a temperature below 8 K. The configuration, the phase shifters and the regenerative materials of the developed two types of two-stage high frequency pulse tube refrigerator will be discussed, and some typical experimental results and considerations for achieving a better performance will also be presented in this paper.

  5. FI/SI on-line solvent extraction/back extraction preconcentration coupled to direct injection nebulization inductively coupled plasma mass spectrometry for determination of copper and lead

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection on-line preconcentration procedure for determination of trace levels of copper and lead via solvent extraction/back extraction coupled to ICP-MS is described. In citrate buffer of pH 3, neutral complexes between the analytes and the chelating reagent, ammonium...... loop, the content of which is subsequently introduced into the ICP-MS, via a direct injection high efficiency nebulizer (DIHEN), for quantification. Enrichment factors of 29.6 (Cu) and 23.3 (Pb), detection limits of 17 ng/l (Cu) and 11 ng/l (Pb), along with a sampling frequency of 13 s/h were obtained...

  6. Finite-element simulations of coupling capacitances in capacitively coupled pixel detectors

    CERN Document Server

    AUTHOR|(SzGeCERN)755510

    2017-01-01

    Capacitively coupled hybrid silicon pixel-detector assemblies are under study for the vertex detector at the proposed future CLIC linear electron-positron collider. The assemblies consist of active CCPDv3 sensors, with 25 μm pixel pitch implemented in a 180 nm High- Voltage CMOS process, which are glued to the CLICpix readout ASIC, with the same pixel pitch and processed in a commercial 65 nm CMOS technology. The signal created in the silicon bulk of the active sensors passes a two-stage amplifier, in each pixel, and gets transferred as a voltage pulse to metal pads facing the readout chip (ROC). The coupling of the signal to the metal pads on the ROC side proceeds through the capacitors formed between the two chips by a thin layer of epoxy glue. The coupling strength and the amount of unwanted cross coupling to neighbouring pixels depends critically on the uniformity of the glue layer, its thickness and on the alignment precision during the flip-chip assembly process. Finite-element calculations of the coup...

  7. Approximation scheme for strongly coupled plasmas: Dynamical theory

    International Nuclear Information System (INIS)

    Golden, K.I.; Kalman, G.

    1979-01-01

    The authors present a self-consistent approximation scheme for the calculation of the dynamical polarizability α (k, ω) at long wavelengths in strongly coupled one-component plasmas. Development of the scheme is carried out in two stages. The first stage follows the earlier Golden-Kalman-Silevitch (GKS) velocity-average approximation approach, but goes much further in its application of the nonlinear fluctuation-dissipation theorem to dynamical calculations. The result is the simple expression for α (k, ω), αatsub GKSat(k, ω) 4 moment sum rule. In the second stage, the above dynamical expression is made self-consistent at long wavelengths by postulating that a decomposition of the quadratic polarizabilities in terms of linear ones, which prevails in the k → 0 limit for weak coupling, can be relied upon as a paradigm for arbitrary coupling. The result is a relatively simple quadratic integral equation for α. Its evaluation in the weak-coupling limit and its comparison with known exact results in that limit reveal that almost all important correlational and long-time effects are reproduced by our theory with very good numerical accuracy over the entire frequency range; the only significant defect of the approximation seems to be the absence of the ''dominant'' γ ln γ -1 (γ is the plasma parameter) contribution to Im α

  8. Development of a direct hydride generation nebulizer for the determination of selenium by inductively coupled plasma optical emission spectrometry

    International Nuclear Information System (INIS)

    Carrion, Nereida; Murillo, Miguel; Montiel, Edie; Diaz, Dorfe

    2003-01-01

    A study was conducted to evaluate the performance of a new direct hydride generation nebulizer system for determination of hydride forming elements by inductively coupled plasma optical emission spectroscopy. This system was designed and optimized to obtain the highest sensitivity. Several experimental designs were used for these purposes. To optimize the individual parameters of the system, and to study the interaction between these parameters for both direct hydride generation nebulizers, a central composite orthogonal design with eight factors was set up. Significant behavioral differences were observed in the two direct hydride generation nebulizers studied. Finally, a 70 μm gas orifice nebulizer exhibits a better detection limit than the 120 μm nebulizer. Generally, for determination of selenium, this new direct hydride generation nebulizer system exhibits a linear dynamic range and detection limit (3σb) of 3 orders of magnitude and 0.2 μg l -1 for selenium, respectively. This new hydride generator is much simpler system that conventional hydride generation systems, which does not need to be changed to work in normal mode with the inductively coupled plasma, since this system may be used for hydride forming elements and those that do not form them. It produces a rapid response with low memory effect. It reduces the interference level of Ni, Co and Cu to 600, 500 and 5 mg l -1 , respectively. The accuracy of the system was verified by the determination of selenium in several standard reference materials of ambient, food and clinical sample matrices. No statistically significant differences (95 confidence level) were obtained between our method and the reference values

  9. Runx expression is mitogenic and mutually linked to Wnt activity in blastula-stage sea urchin embryos.

    Directory of Open Access Journals (Sweden)

    Anthony J Robertson

    Full Text Available The Runt homology domain (Runx defines a metazoan family of sequence-specific transcriptional regulatory proteins that are critical for animal development and causally associated with a variety of mammalian cancers. The sea urchin Runx gene SpRunt-1 is expressed throughout the blastula stage embryo, and is required globally during embryogenesis for cell survival and differentiation.Depletion of SpRunt-1 by morpholino antisense-mediated knockdown causes a blastula stage deficit in cell proliferation, as shown by bromodeoxyuridine (BrdU incorporation and direct cell counts. Reverse transcription coupled polymerase chain reaction (RT-PCR studies show that the cell proliferation deficit is presaged by a deficit in the expression of several zygotic wnt genes, including wnt8, a key regulator of endomesoderm development. In addition, SpRunt-1-depleted blastulae underexpress cyclinD, an effector of mitogenic Wnt signaling. Blastula stage cell proliferation is also impeded by knockdown of either wnt8 or cyclinD. Chromatin immunoprecipitation (ChIP indicates that Runx target sites within 5' sequences flanking cyclinD, wnt6 and wnt8 are directly bound by SpRunt-1 protein at late blastula stage. Furthermore, experiments using a green fluorescent protein (GFP reporter transgene show that the blastula-stage operation of a cis-regulatory module previously shown to be required for wnt8 expression (Minokawa et al., Dev. Biol. 288: 545-558, 2005 is dependent on its direct sequence-specific interaction with SpRunt-1. Finally, inhibitor studies and immunoblot analysis show that SpRunt-1 protein levels are negatively regulated by glycogen synthase kinase (GSK-3.These results suggest that Runx expression and Wnt signaling are mutually linked in a feedback circuit that controls cell proliferation during development.

  10. Direct calculation of the spin stiffness on square, triangular and cubic lattices using the coupled cluster method

    OpenAIRE

    Krüger, S. E.; Darradi, R.; Richter, J.; Farnell, D. J. J

    2006-01-01

    We present a method for the direct calculation of the spin stiffness by means of the coupled cluster method. For the spin-half Heisenberg antiferromagnet on the square, the triangular and the cubic lattices we calculate the stiffness in high orders of approximation. For the square and the cubic lattices our results are in very good agreement with the best results available in the literature. For the triangular lattice our result is more precise than any other result obtained so far by other a...

  11. Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

    KAUST Repository

    He, Lipeng

    2012-07-23

    Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

  12. Enhanced reactivities toward amines by introducing an imine arm to the pincer ligand: Direct coupling of two amines to form an imine without oxidant

    KAUST Repository

    He, Lipeng; Chen, Tao; Gong, Dirong; Lai, Zhiping; Huang, Kuo-Wei

    2012-01-01

    Dehydrogenative homocoupling of primary alcohols to form esters and coupling of amines to form imines was accomplished using a class of novel pincer ruthenium complexes. The reactivities of the ruthenium pincer complexes for the direct coupling of amines to form imines were enhanced by introducing an imine arm to the pincer ligand. Selective oxidation of benzylamines to imines was achieved using aniline derivatives as the substrate and solvent. © 2012 American Chemical Society.

  13. Investigating the use of multi-point coupling for single-sensor bearing estimation in one direction

    Science.gov (United States)

    Woolard, Americo G.; Phoenix, Austin A.; Tarazaga, Pablo A.

    2018-04-01

    Bearing estimation of radially propagating symmetric waves in solid structures typically requires a minimum of two sensors. As a test specimen, this research investigates the use of multi-point coupling to provide directional inference using a single-sensor. By this provision, the number of sensors required for localization can be reduced. A finite-element model of a beam is constructed with a symmetrically placed bipod that has asymmetric joint-stiffness properties. Impulse loading is applied at different points along the beam, and measurements are taken from the apex of the bipod. A technique is developed to determine the direction-of-arrival of the propagating wave. The accuracy when using the bipod with the developed technique is compared against results gathered without the bipod and measuring from an asymmetric location along the beam. The results show 92% accuracy when the bipod is used, compared to 75% when measuring without the bipod from an asymmetric location. A geometry investigation finds the best accuracy results when one leg of the bipod has a low stiffness and a large diameter relative to the other leg.

  14. Modification of irrational ideas and test anxiety through rational stage directed hypnotherapy [RSDH].

    Science.gov (United States)

    Boutin, G E; Tosi, D J

    1983-05-01

    Examined the effects of four treatment conditions on the modification of Irrational Ideas and test anxiety in female nursing students. The treatments were Rational Stage Directed Hypnotherapy, a cognitive behavioral approach that utilized hypnosis and vivid-emotive-imagery, a hypnosis-only treatment, a placebo condition, and a no-treatment control. The 48 Ss were assigned randomly to one of these treatment groups, which met for 1 hour per week for 6 consecutive weeks with in-vivo homework assignments also utilized. Statistically significant treatment effects on cognitive, affective, behavioral, and physiological measures were noted for both the RSDH and hypnosis group at the posttest and at a 2-month follow-up. Post-hoc analyses revealed the RSDH treatment group to be significantly more effective than the hypnosis only group on both the post- and follow-up tests. The placebo and control groups showed no significant effects either at post-treatment or at follow-up.

  15. DECOVALEX III PROJECT. Thermal-Hydro-Mechanical Coupled Processes in Safety Assessments. Report of Task 4

    International Nuclear Information System (INIS)

    Andersson, Johan

    2005-02-01

    A part (Task 4) of the International DECOVALEX III project on coupled thermo-hydro-mechanical (T-H-M) processes focuses on T-H-M modelling applications in safety and performance assessment of deep geological nuclear waste repositories. A previous phase, DECOVALEX II, saw a need to improve such modelling. In order to address this need Task 4 of DECOVALEX III has: Analysed two major T-H-M experiments (Task 1 and Task 2) and three different Bench Mark Tests (Task 3) set-up to explore the significance of T-H-M in some potentially important safety assessment applications. Compiled and evaluated the use of T-H-M modelling in safety assessments at the time of the year 2000. Organised a forum a forum of interchange between PA-analysts and THM modelers at each DECOVALEX III workshop. Based on this information the current report discusses the findings and strives for reaching recommendations as regards good practices in addressing coupled T-H-M issues in safety assessments. The full development of T-H-M modelling is still at an early stage and it is not evident whether current codes provide the information that is required. However, although the geosphere is a system of fully coupled processes, this does not directly imply that all existing coupled mechanisms must be represented numerically. Modelling is conducted for specific purposes and the required confidence level should be considered. It is necessary to match the confidence level with the modelling objective. Coupled THM modelling has to incorporate uncertainties. These uncertainties mainly concern uncertainties in the conceptual model and uncertainty in data. Assessing data uncertainty is important when judging the need to model coupled processes. Often data uncertainty is more significant than the coupled effects. The emphasis on the need for THM modelling differs among disciplines. For geological radioactive waste disposal in crystalline and other similar hard rock formations DECOVALEX III shows it is essential to

  16. DECOVALEX III PROJECT. Thermal-Hydro-Mechanical Coupled Processes in Safety Assessments. Report of Task 4

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden)

    2005-02-15

    A part (Task 4) of the International DECOVALEX III project on coupled thermo-hydro-mechanical (T-H-M) processes focuses on T-H-M modelling applications in safety and performance assessment of deep geological nuclear waste repositories. A previous phase, DECOVALEX II, saw a need to improve such modelling. In order to address this need Task 4 of DECOVALEX III has: Analysed two major T-H-M experiments (Task 1 and Task 2) and three different Bench Mark Tests (Task 3) set-up to explore the significance of T-H-M in some potentially important safety assessment applications. Compiled and evaluated the use of T-H-M modelling in safety assessments at the time of the year 2000. Organised a forum a forum of interchange between PA-analysts and THM modelers at each DECOVALEX III workshop. Based on this information the current report discusses the findings and strives for reaching recommendations as regards good practices in addressing coupled T-H-M issues in safety assessments. The full development of T-H-M modelling is still at an early stage and it is not evident whether current codes provide the information that is required. However, although the geosphere is a system of fully coupled processes, this does not directly imply that all existing coupled mechanisms must be represented numerically. Modelling is conducted for specific purposes and the required confidence level should be considered. It is necessary to match the confidence level with the modelling objective. Coupled THM modelling has to incorporate uncertainties. These uncertainties mainly concern uncertainties in the conceptual model and uncertainty in data. Assessing data uncertainty is important when judging the need to model coupled processes. Often data uncertainty is more significant than the coupled effects. The emphasis on the need for THM modelling differs among disciplines. For geological radioactive waste disposal in crystalline and other similar hard rock formations DECOVALEX III shows it is essential to

  17. Rate dependent direct inverse hysteresis compensation of piezoelectric micro-actuator used in dual-stage hard disk drive head positioning system.

    Science.gov (United States)

    Rahman, Md Arifur; Al Mamun, Abdullah; Yao, Kui

    2015-08-01

    The head positioning servo system in hard disk drive is implemented nowadays using a dual-stage actuator—the primary stage consisting of a voice coil motor actuator providing long range motion and the secondary stage controlling the position of the read/write head with fine resolution. Piezoelectric micro-actuator made of lead zirconate titanate (PZT) has been a popular choice for the secondary stage. However, PZT micro-actuator exhibits hysteresis—an inherent nonlinear characteristic of piezoelectric material. The advantage expected from using the secondary micro-actuator is somewhat lost by the hysteresis of the micro-actuator that contributes to tracking error. Hysteresis nonlinearity adversely affects the performance and, if not compensated, may cause inaccuracy and oscillation in the response. Compensation of hysteresis is therefore an important aspect for designing head-positioning servo system. This paper presents a new rate dependent model of hysteresis along with rigorous analysis and identification of the model. Parameters of the model are found using particle swarm optimization. Direct inverse of the proposed rate-dependent generalized Prandtl-Ishlinskii model is used as the hysteresis compensator. Effectiveness of the overall solution is underscored through experimental results.

  18. Dynamic solar-powered multi-stage direct contact membrane distillation system: Concept design, modeling and simulation

    KAUST Repository

    Lee, Jung Gil

    2017-04-26

    This paper presents a theoretical analysis of the monthly average daily and hourly performances of a solar-powered multi-stage direct contact membrane distillation (SMDCMD) system with an energy recovery scheme and dynamic operating system. Mid-latitude meteorological data from Busan, Korea is employed, featuring large climate variation over the course of one year. The number of module stages used by the dynamic operating scheme changes dynamically based on the inlet feed temperature of the successive modules, which results in an improvement of the water production and thermal efficiency. The simulations of the SMDCMD system are carried out to investigate the spatial and temporal variations in the feed and permeate temperatures and permeate flux. The monthly average daily water production increases from 0.37m3/day to 0.4m3/day and thermal efficiency increases from 31% to 45% when comparing systems both without and with dynamic operation in December. The water production with respect to collector area ranged from 350m2 to 550m2 and the seawater storage tank volume ranged from 16m3 to 28.8m3, and the solar fraction at various desired feed temperatures from 50°C to 80°C have been investigated in October and December.

  19. MgB{sub 2} magnetometer with a directly coupled pick-up loop

    Energy Technology Data Exchange (ETDEWEB)

    Portesi, C [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Mijatovic, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Veldhuis, D [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Brinkman, A [Low Temperature Division and Mesa Research Institute, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Monticone, E [Istituto Elettrotecnico Nazionale Galileo Ferraris, Strada delle Cacce 91, I-10135 Turin (Italy); Gonnelli, R S [INFM, Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)

    2006-05-15

    In this work, we show the results obtained in the fabrication and characterization of an MgB{sub 2} magnetometer with a directly coupled pick-up loop. We used an all in situ technique for fabricating magnesium diboride films, which consists of the co-evaporation of B and Mg by means of an e-gun and a resistive heater respectively. Consequently, we realized the superconducting device, which incorporates two nanobridges as weak links in a superconducting loop. The nanobridges were realized by focused ion beam milling; they were 240 nm wide and had a critical current density of 10{sup 7} A cm{sup -2}. The magnetometer was characterized at different temperatures and also measurements of the noise levels have been performed. The device shows Josephson quantum interference up to 20 K and the calculated effective area at low temperatures was 0.24 mm{sup 2}. The transport properties of the magnetometer allow determining fundamental materials properties of the MgB{sub 2} thin films, such as the penetration depth.

  20. Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents

    NARCIS (Netherlands)

    Vila, Carlos; Giannerini, Massimo; Hornillos, Valentin; Fananas-Mastral, Martin; Feringa, Ben L.

    2014-01-01

    Palladium-catalysed cross-coupling of secondary C(sp(3)) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation

  1. DEVELOPMENT OF COMPUTER AIDED DESIGN OF CHAIN COUPLING

    Directory of Open Access Journals (Sweden)

    Sergey Aleksandrovich Sergeev

    2015-12-01

    Full Text Available The present paper describes the development stages of computer-aided design of chain couplings. The first stage is the automation of traditional design techniques (intermediate automation. The second integrated automation with the development of automated equipment and production technology, including on the basis of flexible manufacturing systems (high level of automation.

  2. Situational variation in moral judgment: In a stage or on a stage?

    Science.gov (United States)

    Carpendale, J I; Krebs, D L

    1992-04-01

    Two issues were examined in this study-the consistency of moral judgment across different types of dilemma and different social contexts, and the relationship between the structure (stage) of moral judgment and the content of moral decisions. Forty subjects were given two hypothetical dilemmas about business decisions and two standard Kohlberg dilemmas. Half the subjects directed their responses to a business audience, half to a philosophical audience. Responses to the moral dilemmas were scored in accordance with the Colby and Kohlberg (1987) scoring manual. Stage of moral reasoning was found to be significantly higher on the Kohlberg dilemmas than on the business dilemmas. A significant interaction between type of dilemma and audience was attributed to the tendency of subjects directing their responses to a business audience to interpret one of the business dilemmas in terms of the moral order of business, but for subjects directing their responses to a philosophy audience to treat it as a philosophical dilemma. The other business dilemma evoked uniformly low-level moral judgments. The amount of selfishness intrinsic in subjects' moral choices on the business dilemmas was significantly negatively correlated with moral maturity on the business dilemmas, but not with their moral maturity on Kohlberg's test. These results are interpreted as more consistent with models of moral development such as those advanced by C. G. Levine ([1979] "Stage Acquisition and Stage Use: An Appraisal of Stage Displacement Explanations of Variation in Moral Reasoning, " Human Development, Vol. 22, pp. 145-164), J. Rest ([1983] "Morality," in: P. H. Mussen [ed.], J. H. Flavell and E. Markman [Vol. eds.], Handbook of Child Psychology [Vol. 3, 4th ed.], John Wiley & Sons, New York), and R. Harré ([1984]) Personal Being: A Theory for Individual Psychology, Harvard University Press, Cambridge, Massachusetts), which posit a relatively wide range of within-person stage use and emphasize the

  3. Top down viewing of the inductively coupled plasma using a dual grating, direct reading spectrograph and an all mirror optical system

    International Nuclear Information System (INIS)

    Apel, C.T.; Duchane, D.V.; Palmer, B.A.

    1980-01-01

    Using an all-mirror optical system, an inductively coupled plasma is viewed top down and the light is directed to a dual grating, direct reading spectrograph. Top down viewing of the plasma, with masking of the image of the argon plasma torus at the spectrograph entrance slit, significantly reduces background signal from the source and permits the use of the depth of field of the optical system to achieve compromise conditions for viewing the plasma. Light from the plasma source is introduced to the optical system by means of a mirror situated directly over the plasma. The system is exhausted in such a way that cool air flowing past the mirror forms a thermal barrier between the mirror and the plasma. Elements such as copper and lead have atomic and ionic lines which tend to exhibit self absorption when viewed top down through the cooler ground state atoms in the plume of the plasma. One of the approaches to this problem is to shear off the plume of the plasma with a jet of air directed across the tip of the plasma. A second approach is to make use of the dual grating, direct reading spectrograph and real-time computer system which easily permits the setting of alternate lines for each element so that self absorption and matrix effects are minimized. The design of the dual-grating, direct-reading spectrograph allows for the mounting of more than 200 13-mm-dia photomultiplier tubes along the focal curves. In an effort to demonstrate the use of fiber optics as a viable technique for the closer placement of exit slits, a red sensitive photomultiplier tube was coupled with a 30-cm fiber-optic ribbon to detect light from the Li 670.784 nm line on the focal curve. It was successful and had the added advantages of absorbing second-order ultraviolet light

  4. THE DEVELOPMENT OF IODINE BASED IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF HG USING DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

    Science.gov (United States)

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hgo) in EPA Method 5 type sampling. An iodine based impinger solutoin proved to be ver...

  5. A directly coupled monolithic rectangular resonator forming a robust microwave plasma ion source for SIFT-MS

    International Nuclear Information System (INIS)

    Spanel, P; Hall, E F H; Workman, C T; Smith, D

    2004-01-01

    A simple ion source is described that consists of a glass discharge tube positioned judiciously in a rectangular waveguide resonator that is directly coupled to an under-run standard magnetron. This ion source operates well with gas mixtures, including rare gases, air and water vapour in the pressure range 10-100 Pa and at magnetron powers within the range 15-40 W. The main advantage of this magnetron/cavity arrangement is the absence of mechanically adjustable parts (aerial and tuning stub), in contrast to other commonly used arrangements that combine a cavity resonator that is connected to the magnetron via a launcher and a coaxial cable

  6. A directly coupled monolithic rectangular resonator forming a robust microwave plasma ion source for SIFT-MS

    Energy Technology Data Exchange (ETDEWEB)

    Spanel, P [Trans Spectra Limited, 9 The Elms, Newcastle under Lyme, ST5 8RP (United Kingdom); Hall, E F H [Trans Spectra Limited, 9 The Elms, Newcastle under Lyme, ST5 8RP (United Kingdom); Workman, C T [Trans Spectra Limited, 9 The Elms, Newcastle under Lyme, ST5 8RP (United Kingdom); Smith, D [Trans Spectra Limited, 9 The Elms, Newcastle under Lyme, ST5 8RP (United Kingdom)

    2004-05-01

    A simple ion source is described that consists of a glass discharge tube positioned judiciously in a rectangular waveguide resonator that is directly coupled to an under-run standard magnetron. This ion source operates well with gas mixtures, including rare gases, air and water vapour in the pressure range 10-100 Pa and at magnetron powers within the range 15-40 W. The main advantage of this magnetron/cavity arrangement is the absence of mechanically adjustable parts (aerial and tuning stub), in contrast to other commonly used arrangements that combine a cavity resonator that is connected to the magnetron via a launcher and a coaxial cable.

  7. Coupling of the four design stages in the management of nuclear fuel; Acoplamiento de las cuatro etapas de diseno en la administracion de combustible nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Marinez R, R. L.

    2016-07-01

    In this work, the main characteristics of the system to solve the four stages of the nuclear fuel management are presented; the above for boiling water reactors (BWR). The novelty of the system is that a complete solution is obtained in a coupled way; the involved stages are fuel lattice design, fuel assembly design, fuel reload design and control rod pattern design. To do this, in each stage of the process some heuristics techniques are applied, and each stage has its own objective function. The used heuristic techniques are neural network and a hybrid between scatter search and path re linking for fuel lattice design; for fuel assembly design a simple local search was applied and finally, for both fuel reload and control rod pattern designs, the tabu search technique was used. The system have two loops, one external loop and one internal loop, the first one starts with fuel lattice design and concludes with control rod pattern design; on the other hand, the internal loop executes an iterative process between both fuel reload design and control rod pattern designs, to start this loop a seed fuel reload is required, which is obtained applying Haling principle. The internal loop is finished when four iterations were achieved, while the external loop is finished when two iterations were achieved, this number of iterations was fixed due to the great quantity of required computational resources. An 18- months equilibrium cycle was considered to have a reference value to compare against the obtained results with our system, this cycle have two fuel fresh batches with the same average uranium enrichment, but different gadolinia content. The above cycle achieved a 10,896 Mwd/Tu of energy and was divided into 12 burnup steps. The obtained results show the advantage to solve the complete problem in a coupled way, even though a great quantity of computational resources are used. It is necessary to note that the energy value was not achieved in all cases, only in some

  8. A novel, fast and efficient single-sensor automatic sleep-stage classification based on complementary cross-frequency coupling estimates.

    Science.gov (United States)

    Dimitriadis, Stavros I; Salis, Christos; Linden, David

    2018-04-01

    Limitations of the manual scoring of polysomnograms, which include data from electroencephalogram (EEG), electro-oculogram (EOG), electrocardiogram (ECG) and electromyogram (EMG) channels have long been recognized. Manual staging is resource intensive and time consuming, and thus considerable effort must be spent to ensure inter-rater reliability. As a result, there is a great interest in techniques based on signal processing and machine learning for a completely Automatic Sleep Stage Classification (ASSC). In this paper, we present a single-EEG-sensor ASSC technique based on the dynamic reconfiguration of different aspects of cross-frequency coupling (CFC) estimated between predefined frequency pairs over 5 s epoch lengths. The proposed analytic scheme is demonstrated using the PhysioNet Sleep European Data Format (EDF) Database with repeat recordings from 20 healthy young adults. We validate our methodology in a second sleep dataset. We achieved very high classification sensitivity, specificity and accuracy of 96.2 ± 2.2%, 94.2 ± 2.3%, and 94.4 ± 2.2% across 20 folds, respectively, and also a high mean F1 score (92%, range 90-94%) when a multi-class Naive Bayes classifier was applied. High classification performance has been achieved also in the second sleep dataset. Our method outperformed the accuracy of previous studies not only on different datasets but also on the same database. Single-sensor ASSC makes the entire methodology appropriate for longitudinal monitoring using wearable EEG in real-world and laboratory-oriented environments. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  9. Updated Global Analysis of Higgs Couplings

    CERN Document Server

    Ellis, John

    2013-01-01

    There are many indirect and direct experimental indications that the new particle H discovered by the ATLAS and CMS Collaborations has spin zero and (mostly) positive parity, and that its couplings to other particles are correlated with their masses. Beyond any reasonable doubt, it is a Higgs boson, and here we examine the extent to which its couplings resemble those of the single Higgs boson of the Standard Model. Our global analysis of its couplings to fermions and massive bosons determines that they have the same relative sign as in the Standard Model. We also show directly that these couplings are highly consistent with a dependence on particle masses that is linear to within a few %, and scaled by the conventional electroweak symmetry-breaking scale to within 10%. We also give constraints on loop-induced couplings, on the total Higgs decay width, and on possible invisible decays of the Higgs boson under various assumptions.

  10. Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

    Science.gov (United States)

    Piotrowicz, P. A.; Caneses, J. F.; Showers, M. A.; Green, D. L.; Goulding, R. H.; Caughman, J. B. O.; Biewer, T. M.; Rapp, J.; Ruzic, D. N.

    2018-05-01

    We present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displays characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.

  11. Effect of the nitrogen unshared electron pair on the direct /sup 13/C-/sup 13/C spin-spin coupling constant of a neighboring bond in oximes

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbakov, V.V.; Krivdin, L.B.; Kalabin, G.A.; Trofimov, B.A.

    1986-11-20

    The authors have previously established that the direct /sup 13/C-/sup 13/C coupling constants are stereospecific relative to the orientation of unshared electron pairs (UEP) of nitrogen and oxygen atoms. Here they show that the nitrogen UEP produces a positive contribution to the direct /sup 13/C-/sup 13/C coupling constant of an adjacent syn-periplanar carbon-carbon bond and not to a negative contribution of the corresponding constant of the anti-periplanar bond. Thus, the observed effect is not a consequence of the interaction of the heteroatom UEP with the anti-bonding orbital of the adjacent anti-periplanar bond (n/sub o-o/* interaction) as in the case of anomeric and related effects.

  12. Simultaneous viscous-inviscid coupling via transpiration

    International Nuclear Information System (INIS)

    Yiu, K.F.C.; Giles, M.B.

    1995-01-01

    In viscous-inviscid coupling analysis, the direct coupling technique and the inverse coupling technique are commonly adopted. However, stability and convergence of the algorithms derived are usually very unsatisfactory. Here, by using the transpiration technique to simulate the effect of the displacement thickness, a new simultaneous coupling method is derived. The integral boundary layer equations and the full potential equation are chosen to be the viscous-inviscid coupled system. After discretization, the Newton-Raphson technique is proposed to solve the coupled nonlinear system. Several numerical results are used to demonstrate the accuracy and efficiency of the proposed method. 15 refs., 23 figs

  13. Direct coupling of a solar-hydrogen system in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arriaga, L.G. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico); Centro de Investigacion y Desarrollo Tecnologico en Electroquimica S.C., Parque tecnologico Queretaro Sanfandila, Pedro Escobedo, C.P. 76703 Queretaro (Mexico); Martinez, W. [Departamento de Materiales Solares, CIE-UNAM, Av. Xochicalco s/n, Col. Centro, 62580 Temixco, Morelos (Mexico); Cano, U.; Blud, H. [Gerencia de Energias No Convencionales, Instituto de Investigaciones Electricas (IIE), Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)

    2007-09-15

    The scope of this article is to show the initial results obtained in the interconnection of a 2.7 kW solar panel system with a solid polymer electrolyte (SPE) electrolyzer. The Non-Conventional Energies Department (ENC) at the Electrical Research Institute (IIE) considers that the storage of this intermittent energy by a chemical element such as hydrogen can be advantageous for certain applications. One of the arguments is that unlike traditional battery systems, hydrogen presents the great advantage of not discharging its energy content as long as it is not used. The solar-hydrogen (S-H) system proposed consists of a commercial electrolyzer stack by Proton Energy Systems and a photovoltaic (PV) solar system of 36 panels (75 W each) of monocrystalline silicon (Siemens) interconnected in a configuration for 2.7 kW power at 48V{sub DC}. The complete electrolyzer (stack plus auxiliaries) has a maximum capacity of 1000lN/h of hydrogen with a power energy consumption of 8 kVA (220V{sub AC}, 32 A) and uses a stack of 25 cells of SPE with an energy consumption of 5.6 kW. We present voltage, current and energy consumption of the electrolyzer as a whole system and of the stack alone, as well as hydrogen quantification for the Hogen 40 operating in laboratory. These results allowed us to estimate the possibilities of coupling the electrolyzer stack alone, i.e. no auxiliaries nor power conditioning, with the solar PV system. Results such as I-E curves of the solar PV system obtained at different irradiances and temperatures, as well as I-E curve of SPE electrolyzer stack, gave direction for confirming that PV system configuration was sufficiently good to have the electrolyzer stack working near the maximum power point at a good range of irradiances ({proportional_to}600-800W/m{sup 2}). (author)

  14. Direct Observation of Strong Ion Coupling in Laser-Driven Shock-Compressed Targets

    International Nuclear Information System (INIS)

    Ravasio, A.; Benuzzi-Mounaix, A.; Loupias, B.; Ozaki, N.; Rabec le Gloahec, M.; Koenig, M.; Gregori, G.; Daligault, J.; Delserieys, A.; Riley, D.; Faenov, A. Ya.; Pikuz, T. A.

    2007-01-01

    In this Letter we report on a near collective x-ray scattering experiment on shock-compressed targets. A highly coupled Al plasma was generated and probed by spectrally resolving an x-ray source forward scattered by the sample. A significant reduction in the intensity of the elastic scatter was observed, which we attribute to the formation of an incipient long-range order. This speculation is confirmed by x-ray scattering calculations accounting for both electron degeneracy and strong coupling effects. Measurements from rear side visible diagnostics are consistent with the plasma parameters inferred from x-ray scattering data. These results give the experimental evidence of the strongly coupled ionic dynamics in dense plasmas

  15. Effect of Couple Therapy Based on the Choice Theory on Social Commitment of Couples

    Directory of Open Access Journals (Sweden)

    Hossein Abbasi

    2017-09-01

    Full Text Available Background and Objective: Commitment to spouse, marriage, and family is one of the most important factors ensuring the continuity of marriage and strength of family bonds that has attracted considerable attention in the contemporary family and marriage studies. In this study, we sought to determine the effect of couple therapy based on the choice theory on the social commitment of couples. Materials and Methods: This was a quasi-experimental study with pretest-posttest design and a control group that was performed among volunteer couples visiting Isfahan Counseling and Psychology Centers in Isfahan, Iran, during 2015. The subjects consisted of 32 incompatible couples who were selected through convenience sampling and were randomly assigned into experimental (16 couples and control (16 couples groups. Then, the experimental group received nine sessions of group couple therapy during three months on family life skills based on choice theory. It is worth mentioning that the dependent variable was the social commitment of couples evaluated by the dimensions of commitment inventory of Adams and Jones (1997. The collected data were analyzed by multivariate analysis of covariance in SPSS, version 20. Results: At the post-test stage, couple therapy based on choice theory significantly enhanced social commitment in the experimental group compared to the control group (P<0.001. Conclusion: According to the findings of this study, couple therapy based on the choice theory is an effective strategy in promoting commitment and loyalty to spouse, marriage, and family and can decrease and prevent family-related problems and threats such as divorce and marital infidelity.

  16. Polyglutamate directed coupling of bioactive peptides for the delivery of osteoinductive signals on allograft bone

    Science.gov (United States)

    Culpepper, Bonnie K.; Bonvallet, Paul P.; Reddy, Michael S.; Ponnazhagan, Selvarangan; Bellis, Susan L.

    2012-01-01

    Allograft bone is commonly used as an alternative to autograft, however allograft lacks many osteoinductive factors present in autologous bone due to processing. In this study, we investigated a method to reconstitute allograft with osteoregenerative factors. Specifically, an osteoinductive peptide from collagen I, DGEA, was engineered to express a heptaglutamate (E7) domain, which binds the hydroxyapatite within bone mineral. Addition of E7 to DGEA resulted in 9× greater peptide loading on allograft, and significantly greater retention after a 5-day interval with extensive washing. When factoring together greater initial loading and retention, the E7 domain directed a 45-fold enhancement of peptide density on the allograft surface. Peptide-coated allograft was also implanted subcutaneously into rats and it was found that E7DGEA was retained in vivo for at least 3 months. Interestingly, E7DGEA peptides injected intravenously accumulated within bone tissue, implicating a potential role for E7 domains in drug delivery to bone. Finally, we determined that, as with DGEA, the E7 modification enhanced coupling of a bioactive BMP2-derived peptide on allograft. These results suggest that E7 domains are useful for coupling many types of bone-regenerative molecules to the surface of allograft to reintroduce osteoinductive signals and potentially advance allograft treatments. PMID:23182349

  17. Batch pervaporative fermentation with coupled membrane and its influence on energy consumption in permeate recovery and distillation stage

    International Nuclear Information System (INIS)

    Leon, Juan A.; Palacios-Bereche, Reynaldo; Nebra, Silvia A.

    2016-01-01

    In the ethanol production process from sugarcane molasses, the distillation process is a high-energy demand stage. The distillation energy efficiency is strongly associated with the alcoholic fermentation performance in the process. The final ethanol concentration in the alcoholic wines has a direct impact on consumption of thermal energy in ethanol separation. In this paper, ethanol production with a H-SBMF (Hybrid-Simple Batch Membrane Fermenter) using PDMS (polydimethylsiloxane) pervaporation membrane was modelled and simulated, in order to determine its influence on energy consumption in distillation. Steam in distillation and electrical energy needs in permeate recovery were mainly influenced by membrane adaptation. The H-SBMF achieved a higher ethanol production in the range of 10–13% compared to the conventional batch fermenter, and an increase in productivity of 150%. The distillation system consisted of two sets of columns: the ethanol recovery column and the rectification column. The permeate recovery system (i.e. vacuum and compression) was regarded in order to evaluate the electrical energy requirement, and the thermal energy demand was evaluated. A decrease in steam consumption was evidenced by the adaptation of the membrane to the fermenter. Higher energy efficiencies were achieved in distillation with larger membrane areas, achieving almost 17% steam reduction. - Highlights: • Higher and faster ethanol productions were achieved by fermenter hybridization. • Multi-stage permeate compression and inter-stage heat recovery were assumed. • Energy demand was studied based on an integrated fermentation and distillation scheme. • High-energy efficiency was attained in the distillation to produce hydrated alcohol.

  18. Synchronizing spiral waves in a coupled Rössler system

    International Nuclear Information System (INIS)

    Gao Jia-Zhen; Yang Shu-Xin; Xie Ling-Ling; Gao Ji-Hua

    2011-01-01

    The synchronisation of spiral patterns in a drive-response Rössler system is studied. The existence of three types of synchronisation is revealed by inspecting the coupling parameter space. Two transient stages of phase synchronisation and partial synchronisation are observed in a comparatively weak feedback coupling parameter regime, whilst complete synchronisation of spirals is found with strong negative couplings. Detailed observations of the synchronous process, such as oscillatory frequencies, parameters mismatches and amplitude variations, etc, are investigated via numerical simulations. (general)

  19. First-principles approach to the dynamic magnetoelectric couplings for the non-reciprocal directional dichroism in BiFeO3

    Science.gov (United States)

    Lee, Jun Hee; Kézsmáki, István; Fishman, Randy S.

    2016-04-01

    Due to the complicated magnetic and crystallographic structures of BiFeO3, its magnetoelectric (ME) couplings and microscopic model Hamiltonian remain poorly understood. By employing a first-principles approach, we uncover all possible ME couplings associated with the spin-current (SC) and exchange-striction (ES) polarizations, and construct an appropriate Hamiltonian for the long-range spin-cycloid in BiFeO3. First-principles calculations are used to understand the microscopic origins of the ME couplings. We find that inversion symmetries broken by ferroelectric and antiferroelectric distortions induce the SC and the ES polarizations, which cooperatively produce the dynamic ME effects in BiFeO3. A model motivated by first principles reproduces the absorption difference of counter-propagating light beams called non-reciprocal directional dichroism. The current paper focuses on the spin-driven (SD) polarizations produced by a dynamic electric field, i.e. the dynamic ME couplings. Due to the inertial properties of Fe, the dynamic SD polarizations differ significantly from the static SD polarizations. Our systematic approach can be generally applied to any multiferroic material, laying the foundation for revealing hidden ME couplings on the atomic scale and for exploiting optical ME effects in the next generation of technological devices such as optical diodes. This manuscript has been written by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan.

  20. A Simple Catalytic Mechanism for the Direct Coupling of α-Carbonyls with Functionalized Amines: A One-Step Synthesis of Plavix

    OpenAIRE

    Evans, Ryan W.; Zbieg, Jason R.; Zhu, Shaolin; Li, Wei; MacMillan, David W. C.

    2013-01-01

    The direct α-amination of ketones, esters, and aldehydes has been accomplished via copper catalysis. In the presence of catalytic copper(II) bromide, a diverse range of carbonyl and amine substrates undergo fragment coupling to produce synthetically useful α-amino substituted motifs. The transformation is proposed to proceed via a catalytically generated α-bromo carbonyl species; nucleophilic displacement of the bromide by the amine then delivers the α-amino carbonyl adduct while the catalyst...

  1. Direct detection of early-stage cancers using circulating tumor DNA

    DEFF Research Database (Denmark)

    Phallen, Jillian; Sausen, Mark; Adleff, Vilmos

    2017-01-01

    Early detection and intervention are likely to be the most effective means for reducing morbidity and mortality of human cancer. However, development of methods for noninvasive detection of early-stage tumors has remained a challenge. We have developed an approach called targeted error correction...

  2. Achieving Synchronization in Arrays of Coupled Differential Systems with Time-Varying Couplings

    Directory of Open Access Journals (Sweden)

    Xinlei Yi

    2013-01-01

    Full Text Available We study complete synchronization of the complex dynamical networks described by linearly coupled ordinary differential equation systems (LCODEs. Here, the coupling is timevarying in both network structure and reaction dynamics. Inspired by our previous paper (Lu et al. (2007-2008, the extended Hajnal diameter is introduced and used to measure the synchronization in a general differential system. Then we find that the Hajnal diameter of the linear system induced by the time-varying coupling matrix and the largest Lyapunov exponent of the synchronized system play the key roles in synchronization analysis of LCODEs with identity inner coupling matrix. As an application, we obtain a general sufficient condition guaranteeing directed time-varying graph to reach consensus. Example with numerical simulation is provided to show the effectiveness of the theoretical results.

  3. Stac3 has a direct role in skeletal muscle-type excitation-contraction coupling that is disrupted by a myopathy-causing mutation.

    Science.gov (United States)

    Polster, Alexander; Nelson, Benjamin R; Olson, Eric N; Beam, Kurt G

    2016-09-27

    In skeletal muscle, conformational coupling between CaV1.1 in the plasma membrane and type 1 ryanodine receptor (RyR1) in the sarcoplasmic reticulum (SR) is thought to underlie both excitation-contraction (EC) coupling Ca(2+) release from the SR and retrograde coupling by which RyR1 increases the magnitude of the Ca(2+) current via CaV1.1. Recent work has shown that EC coupling fails in muscle from mice and fish null for the protein Stac3 (SH3 and cysteine-rich domain 3) but did not establish the functional role of Stac3 in the CaV1.1-RyR1 interaction. We investigated this using both tsA201 cells and Stac3 KO myotubes. While confirming in tsA201 cells that Stac3 could support surface expression of CaV1.1 (coexpressed with its auxiliary β1a and α2-δ1 subunits) and the generation of large Ca(2+) currents, we found that without Stac3 the auxiliary γ1 subunit also supported membrane expression of CaV1.1/β1a/α2-δ1, but that this combination generated only tiny Ca(2+) currents. In Stac3 KO myotubes, there was reduced, but still substantial CaV1.1 in the plasma membrane. However, the CaV1.1 remaining in Stac3 KO myotubes did not generate appreciable Ca(2+) currents or EC coupling Ca(2+) release. Expression of WT Stac3 in Stac3 KO myotubes fully restored Ca(2+) currents and EC coupling Ca(2+) release, whereas expression of Stac3W280S (containing the Native American myopathy mutation) partially restored Ca(2+) currents but only marginally restored EC coupling. We conclude that membrane trafficking of CaV1.1 is facilitated by, but does not require, Stac3, and that Stac3 is directly involved in conformational coupling between CaV1.1 and RyR1.

  4. Palladium-Catalysed Direct Cross-Coupling of Organolithium Reagents with Aryl and Vinyl Triflates

    NARCIS (Netherlands)

    Vila, Carlos; Hornillos, Valentin; Giannerini, Massimo; Fananas-Mastral, Martin; Feringa, Bernard L.

    2014-01-01

    Carbon-Carbon Bond Formation Carbon-carbon bond formation by the cross-coupling of highly reactive organolithium reagents is a major challenge. Recently, it was demonstrated that palladium catalysts are able to couple organic halides with various organolithium species under mild conditions in a

  5. Thermodynamically coupled mass transport processes in a saturated clay

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1984-01-01

    Gradients of temperature, pressure, and fluid composition in saturated clays give rise to coupled transport processes (thermal and chemical osmosis, thermal diffusion, ultrafiltration) in addition to the direct processes (advection and diffusion). One-dimension transport of water and a solute in a saturated clay subjected to mild gradients of temperature and pressure was simulated numerically. When full coupling was accounted for, volume flux (specific discharge) was controlled by thermal osmosis and chemical osmosis. The two coupled fluxes were oppositely directed, producing a point of stagnation within the clay column. Solute flows were dominated by diffusion, chemical osmosis, and thermal osmosis. Chemical osmosis produced a significant flux of solute directed against the gradient of solute concentration; this effect reduced solute concentrations relative to the case without coupling. Predictions of mass transport in clays at nuclear waste repositories could be significantly in error if coupled transport processes are not accounted for. 14 refs., 8 figs

  6. Thermodynamically coupled mass transport processes in a saturated clay

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1984-11-01

    Gradients of temperature, pressure, and fluid composition in saturated clays give rise to coupled transport processes (thermal and chemical osmosis, thermal diffusion, ultrafiltration) in addition to the direct processes (advection and diffusion). One-dimensional transport of water and a solute in a saturated clay subjected to mild gradients of temperature and pressure was simulated numerically. When full coupling was accounted for, volume flux (specific discharge) was controlled by thermal osmosis and chemical osmosis. The two coupled fluxes were oppositely directed, producing a point of stagnation within the clay column. Solute flows were dominated by diffusion, chemical osmosis, and thermal osmosis. Chemical osmosis produced a significant flux of solute directed against the gradient of solute concentration; this effect reduced solute concentrations relative to the case without coupling. Predictions of mass transport in clays at nuclear waste repositories could be significantly in error if coupled transport processes are not accounted for. 14 references, 8 figures, 1 table

  7. Multiple stage miniature stepping motor

    International Nuclear Information System (INIS)

    Niven, W.A.; Shikany, S.D.; Shira, M.L.

    1981-01-01

    A stepping motor comprising a plurality of stages which may be selectively activated to effect stepping movement of the motor, and which are mounted along a common rotor shaft to achieve considerable reduction in motor size and minimum diameter, whereby sequential activation of the stages results in successive rotor steps with direction being determined by the particular activating sequence followed

  8. Management of End-Stage Ankle Arthritis: Cost-Utility Analysis Using Direct and Indirect Costs.

    Science.gov (United States)

    Nwachukwu, Benedict U; McLawhorn, Alexander S; Simon, Matthew S; Hamid, Kamran S; Demetracopoulos, Constantine A; Deland, Jonathan T; Ellis, Scott J

    2015-07-15

    Total ankle replacement and ankle fusion are costly but clinically effective treatments for ankle arthritis. Prior cost-effectiveness analyses for the management of ankle arthritis have been limited by a lack of consideration of indirect costs and nonoperative management. The purpose of this study was to compare the cost-effectiveness of operative and nonoperative treatments for ankle arthritis with inclusion of direct and indirect costs in the analysis. Markov model analysis was conducted from a health-systems perspective with use of direct costs and from a societal perspective with use of direct and indirect costs. Costs were derived from the 2012 Nationwide Inpatient Sample (NIS) and expressed in 2013 U.S. dollars; effectiveness was expressed in quality-adjusted life years (QALYs). Model transition probabilities were derived from the available literature. The principal outcome measure was the incremental cost-effectiveness ratio (ICER). In the direct-cost analysis for the base case, total ankle replacement was associated with an ICER of $14,500/QALY compared with nonoperative management. When indirect costs were included, total ankle replacement was both more effective and resulted in $5900 and $800 in lifetime cost savings compared with the lifetime costs following nonoperative management and ankle fusion, respectively. At a $100,000/QALY threshold, surgical management of ankle arthritis was preferred for patients younger than ninety-six years and total ankle replacement was increasingly more cost-effective in younger patients. Total ankle replacement, ankle fusion, and nonoperative management were the preferred strategy in 83%, 12%, and 5% of the analyses, respectively; however, our model was sensitive to patient age, the direct costs of total ankle replacement, the failure rate of total ankle replacement, and the probability of arthritis after ankle fusion. Compared with nonoperative treatment for the management of end-stage ankle arthritis, total ankle

  9. Coupled DM Heating in SCDEW Cosmologies

    Directory of Open Access Journals (Sweden)

    Silvio Bonometto

    2017-08-01

    Full Text Available Strongly-Coupled Dark Energy plus Warm dark matter (SCDEW cosmologies admit the stationary presence of ∼1% of coupled-DM and DE, since inflationary reheating. Coupled-DM fluctuations therefore grow up to non-linearity even in the early radiative expansion. Such early non-linear stages are modelized here through the evolution of a top-hat density enhancement, reaching an early virial balance when the coupled-DM density contrast is just 25–26, and the DM density enhancement is ∼10 % of the total density. During the time needed to settle in virial equilibrium, the virial balance conditions, however, continue to modify, so that “virialized” lumps undergo a complete evaporation. Here, we outline that DM particles processed by overdensities preserve a fraction of their virial momentum. Although fully non-relativistic, the resulting velocities (moderately affect the fluctuation dynamics over greater scales, entering the horizon later on.

  10. Stage measurement at gaging stations

    Science.gov (United States)

    Sauer, Vernon B.; Turnipseed, D. Phil

    2010-01-01

    Stream and reservoir stage are critical parameters in the computation of stream discharge and reservoir volume, respectively. In addition, a record of stream stage is useful in the design of structures that may be affected by stream elevation, as well as for the planning for various uses of flood plains. This report describes equipment and methodology for the observation, sensing, and recording of stage in streams and reservoirs. Although the U.S. Geological Survey (USGS) still uses the traditional, basic stilling-well float system as a predominant gaging station, modern electronic stage sensors and water-level recorders are now commonly used. Bubble gages coupled with nonsubmersible pressure transducers eliminate the need for stilling wells. Submersible pressure transducers have become common in use for the measurement of stage in both rivers and lakes. Furthermore, noncontact methods, such as radar, acoustic, and laser methods of sensing water levels, are being developed and tested, and in the case of radar, are commonly used for the measurement of stage. This report describes commonly used gaging-station structures, as well as the design and operation of gaging stations. Almost all of the equipment and instruments described in this report will meet the accuracy standard set by the USGS Office of Surface Water (OSW) for the measurement of stage for most applications, which is ±0.01 foot (ft) or 0.2 percent of the effective stage. Several telemetry systems are used to transmit stage data from the gaging station to the office, although satellite telemetry has become the standard. These telemetry systems provide near real-time stage data, as well as other information that alerts the hydrographer to extreme or abnormal events, and instrument malfunctions.

  11. Anomalous coupling of scalars to gauge fields

    International Nuclear Information System (INIS)

    Brax, Philippe; Davis, Anne-Christine; Seery, David; Weltman, Amanda

    2010-10-01

    We study the transformation properties of a scalar-tensor theory, coupled to fermions, under the Weyl rescaling associated with a transition from the Jordan to the Einstein frame. We give a simple derivation of the corresponding modification to the gauge couplings. After changing frames, this gives rise to a direct coupling between the scalar and the gauge fields. (orig.)

  12. Anomalous coupling of scalars to gauge fields

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [CEA, IPhT, CNRS, URA 2306, Gif-sur-Yvette (France). Inst. de Physique Theorique; Burrage, Clare [Geneve Univ. (Switzerland). Dept. de Physique Theorique; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Davis, Anne-Christine [Centre for Mathematical Sciences, Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Seery, David [Sussex Univ., Brighton (United Kingdom). Dept. of Physics and Astronomy; Weltman, Amanda [Cape Town Univ., Rondebosch (South Africa). Astronomy, Cosmology and Gravity Centre

    2010-10-15

    We study the transformation properties of a scalar-tensor theory, coupled to fermions, under the Weyl rescaling associated with a transition from the Jordan to the Einstein frame. We give a simple derivation of the corresponding modification to the gauge couplings. After changing frames, this gives rise to a direct coupling between the scalar and the gauge fields. (orig.)

  13. Staging with spatial filters

    International Nuclear Information System (INIS)

    Glaze, J.

    1974-01-01

    It is known that small scale beam instabilities limit the focusable energy that can be achieved from a terawatt laser chain. Spatial filters are currently being used on CYCLOPS to ameliorate this problem. Realizing the full advantage of such a filter, however, may require certain staging modifications. A staging methodology is discussed that should be applicable to the CYCLOPS, 381, and SHIVA systems. Experiments are in progress on CYCLOPS that will address directly the utility of the proposed approach

  14. Extensions to the coupling coefficient calculations for muon telescopes

    International Nuclear Information System (INIS)

    Baker, C.P.; Humble, J.E.; Duldig, M.L.

    1989-01-01

    The calculation of coupling coefficients for muon telescopes has previously used interpolation from a limited set of asymptotic directions of arrival of primary particles. Furthermore, these calculations have not incorporated curvature of the atmosphere and thus diverge from the true response at zenith angles greater than about 75 degrees. The necessary extensions to calculate coupling coefficients at arbitrary zenith angles are given, including an improved method of incorporating the asymptotic directions of the primary particles. It is shown, using this method, that certain coupling coefficients are highly sensitive to small changes in asymptotic directions for some telescope configurations. 10 refs., 1 fig., 3 tabs

  15. Extensions to the coupling coefficient calculations for muon telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Baker, C P; Humble, J E [Tasmania Univ., Sandy Bay (Australia). Dept. of Physics; Duldig, M L [Dept. of the Arts, Sport, the Environment, Tourism and Territories, Hobart (Australia). Antarctic Div.

    1989-01-01

    The calculation of coupling coefficients for muon telescopes has previously used interpolation from a limited set of asymptotic directions of arrival of primary particles. Furthermore, these calculations have not incorporated curvature of the atmosphere and thus diverge from the true response at zenith angles greater than about 75 degrees. The necessary extensions to calculate coupling coefficients at arbitrary zenith angles are given, including an improved method of incorporating the asymptotic directions of the primary particles. It is shown, using this method, that certain coupling coefficients are highly sensitive to small changes in asymptotic directions for some telescope configurations. 10 refs., 1 fig., 3 tabs.

  16. Single-phase mixing studies by means of a directly coupled CFD/system-code tool

    International Nuclear Information System (INIS)

    Bertolotto, Davide; Chawla, Rakesh; Manera, Annalisa; Smith, Brian; Prasser, Horst-Michael

    2008-01-01

    The present paper describes the coupling of the 3D computational fluid dynamics (CFD) code CFX with the best estimate thermal-hydraulic code TRACE. Two different coupling schemes, i.e. an explicit and a semi-implicit one, have been tested. Verification of the coupled CFX/TRACE code has first been carried out on the basis of a simple test case consisting of a straight pipe filled with liquid subject to a sudden acceleration. As a second validation step, measurements using advanced instrumentation (wire-mesh sensors) have been performed in a simple, specially constructed test facility consisting of two loops connected by a double T-junction. Comparisons of the measurements are made with calculation results obtained using the coupled codes, as well as the individual codes in stand-alone mode, thereby clearly bringing out the effectiveness of the achieved coupling for simulating situations in which three-dimensional mixing phenomena are important. (authors)

  17. Ag-protein plasmonic architectures for surface plasmon-coupled emission enhancements and Fabry-Perot mode-coupled directional fluorescence emission

    Science.gov (United States)

    Badiya, Pradeep Kumar; Patnaik, Sai Gourang; Srinivasan, Venkatesh; Reddy, Narendra; Manohar, Chelli Sai; Vedarajan, Raman; Mastumi, Noriyoshi; Belliraj, Siva Kumar; Ramamurthy, Sai Sathish

    2017-10-01

    We report the use of silver decorated plant proteins as spacer material for augmented surface plasmon-coupled emission (120-fold enhancement) and plasmon-enhanced Raman scattering. We extracted several proteins from different plant sources [Triticum aestivum (TA), Aegle marmelos (AM), Ricinus communis (RC), Jatropha curcas (JC) and Simarouba glauca (SG)] followed by evaluation of their optical properties and simulations to rationalize observed surface plasmon resonance. Since the properties exhibited by protein thin films is currently gaining research interest, we have also carried out simulation studies with Ag-protein biocomposites as spacer materials in metal-dielectric-metal planar microcavity architecture for guided emission of Fabry-Perot mode-coupled fluorescence.

  18. Axisymmetric alternating direction explicit scheme for efficient coupled simulation of hydro-mechanical interaction in geotechnical engineering—Application to circular footing and deep tunnel in saturated ground

    Directory of Open Access Journals (Sweden)

    Simon Heru Prassetyo

    2018-04-01

    Full Text Available Explicit solution techniques have been widely used in geotechnical engineering for simulating the coupled hydro-mechanical (H-M interaction of fluid flow and deformation induced by structures built above and under saturated ground, i.e. circular footing and deep tunnel. However, the technique is only conditionally stable and requires small time steps, portending its inefficiency for simulating large-scale H-M problems. To improve its efficiency, the unconditionally stable alternating direction explicit (ADE scheme could be used to solve the flow problem. The standard ADE scheme, however, is only moderately accurate and is restricted to uniform grids and plane strain flow conditions. This paper aims to remove these drawbacks by developing a novel high-order ADE scheme capable of solving flow problems in non-uniform grids and under axisymmetric conditions. The new scheme is derived by performing a fourth-order finite difference (FD approximation to the spatial derivatives of the axisymmetric fluid–diffusion equation in a non-uniform grid configuration. The implicit Crank-Nicolson technique is then applied to the resulting approximation, and the subsequent equation is split into two alternating direction sweeps, giving rise to a new axisymmetric ADE scheme. The pore pressure solutions from the new scheme are then sequentially coupled with an existing geomechanical simulator in the computer code fast Lagrangian analysis of continua (FLAC. This coupling procedure is called the sequentially-explicit coupling technique based on the fourth-order axisymmetric ADE scheme or SEA-4-AXI. Application of SEA-4-AXI for solving axisymmetric consolidation of a circular footing and of advancing tunnel in deep saturated ground shows that SEA-4-AXI reduces computer runtime up to 42%–50% that of FLAC's basic scheme without numerical instability. In addition, it produces high numerical accuracy of the H-M solutions with average percentage difference of only 0.5%

  19. Multi-Directional Environmental Sensors

    Science.gov (United States)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement multi-directional environmental sensors. In one embodiment, a multi-directional environmental sensor includes: an inner conductive element that is substantially symmetrical about three orthogonal planes; an outer conductive element that is substantially symmetrical about three orthogonal planes; and a device that measures the electrical characteristics of the multi-directional environmental sensor, the device having a first terminal and a second terminal; where the inner conductive element is substantially enclosed within the outer conductive element; where the inner conductive element is electrically coupled to the first terminal of the device; and where the outer conductive element is electrically coupled to the second terminal of the device.

  20. Simultaneous specimen and stage cleaning device for analytical electron microscope

    Science.gov (United States)

    Zaluzec, Nestor J.

    1996-01-01

    An improved method and apparatus are provided for cleaning both a specimen stage, a specimen and an interior of an analytical electron microscope (AEM). The apparatus for cleaning a specimen stage and specimen comprising a plasma chamber for containing a gas plasma and an air lock coupled to the plasma chamber for permitting passage of the specimen stage and specimen into the plasma chamber and maintaining an airtight chamber. The specimen stage and specimen are subjected to a reactive plasma gas that is either DC or RF excited. The apparatus can be mounted on the analytical electron microscope (AEM) for cleaning the interior of the microscope.

  1. Surrogate versus couple therapy in vaginismus.

    Science.gov (United States)

    Ben-Zion, Itzhak; Rothschild, Shelly; Chudakov, Bella; Aloni, Ronit

    2007-05-01

    Women who do not have a cooperative partner cannot complete the usual therapeutic process in the treatment of vaginismus, because they cannot progress to the stage of practicing the insertion of the man partner's fingers and the insertion of a penis. To compare traditional couple therapy with therapy utilizing a surrogate partner. The study was controlled and retrospective. Data were obtained from the treatment charts of patients who had come to the clinic for treatment of vaginismus. Sixteen vaginismus patients who were treated with a man surrogate partner were compared with 16 vaginismus patients who were treated with their own partners. Successful pain-free intercourse upon completion of therapy. One hundred percent of the surrogate patients succeeded in penile-vaginal intercourse compared with 75% in the couples group (P = 0.1). All surrogate patients ended the therapy because it was fully successful, compared with 69% in the couples group. Twelve percent of the couples group ended the therapy because it failed, and 19% because the couples decided to separate. Treating vaginismus with a man surrogate partner was at least as effective as couple therapy. Surrogate therapy may be considered for vaginismus patients who have no cooperative partner.

  2. WYD method for an eigen solution of coupled problems

    Directory of Open Access Journals (Sweden)

    A Harapin

    2016-04-01

    Full Text Available Designing efficient and stable algorithm for finding the eigenvalues andeigenvectors is very important from the static as well as the dynamic aspectin coupled problems. Modal analysis requires first few significant eigenvectorsand eigenvalues while direct integration requires the highest value toascertain the length of the time step that satisfies the stability condition.The paper first presents the modification of the well known WYDmethod for a solution of single field problems: an efficient and numericallystable algorithm for computing eigenvalues and the correspondingeigenvectors. The modification is based on the special choice of thestarting vector. The starting vector is the static solution of displacements forthe applied load, defined as the product of the mass matrix and the unitdisplacement vector. The starting vector is very close to the theoreticalsolution, which is important in cases of small subspaces.Additionally, the paper briefly presents the adopted formulation for solvingthe fluid-structure coupled systems problems which is based on a separatesolution for each field. Individual fields (fluid and structure are solvedindependently, taking in consideration the interaction information transferbetween them at every stage of the iterative solution process. The assessmentof eigenvalues and eigenvectors for multiple fields is also presented. This eigenproblem is more complicated than the one for the ordinary structural analysis,as the formulation produces non-symmetrical matrices.Finally, a numerical example for the eigen solution coupled fluidstructureproblem is presented to show the efficiency and the accuracy ofthe developed algorithm.

  3. Cross-coupling between accommodation and convergence is optimized for a broad range of directions and distances of gaze.

    Science.gov (United States)

    Nguyen, Dorothy; Vedamurthy, Indu; Schor, Clifton

    2008-03-01

    Accommodation and convergence systems are cross-coupled so that stimulation of one system produces responses by both systems. Ideally, the cross-coupled responses of accommodation and convergence match their respective stimuli. When expressed in diopters and meter angles, respectively, stimuli for accommodation and convergence are equal in the mid-sagittal plane when viewed with symmetrical convergence, where historically, the gains of the cross coupling (AC/A and CA/C ratios) have been quantified. However, targets at non-zero azimuth angles, when viewed with asymmetric convergence, present unequal stimuli for accommodation and convergence. Are the cross-links between the two systems calibrated to compensate for stimulus mismatches that increase with gaze-azimuth? We measured the response AC/A and stimulus CA/C ratios at zero azimuth, 17.5 and 30 deg of rightward gaze eccentricities with a Badal Optometer and Wheatstone-mirror haploscope. AC/A ratios were measured under open-loop convergence conditions along the iso-accommodation circle (locus of points that stimulate approximately equal amounts of accommodation to the two eyes at all azimuth angles). CA/C ratios were measured under open-loop accommodation conditions along the iso-vergence circle (locus of points that stimulate constant convergence at all azimuth angles). Our results show that the gain of accommodative-convergence (AC/A ratio) decreased and the bias of convergence-accommodation increased at the 30 deg gaze eccentricity. These changes are in directions that compensate for stimulus mismatches caused by spatial-viewing geometry during asymmetric convergence.

  4. Bidirectional communication using delay coupled chaotic directly ...

    Indian Academy of Sciences (India)

    Corresponding author. ... 30 September 2009. Abstract. Chaotic synchronization of two directly modulated semiconductor lasers with ... For InGaAsP lasers used in optical communication systems, the nonlinear gain re- duction is very strong and its ...

  5. Improvement of the directional stability of passenger car trailer couplings with actively controlled steering

    Science.gov (United States)

    Desens, Jens

    The stabilization of pendulum oscillations of passenger car trailer couplings, using active steering, was examined. A linear model of the couplings was presented. Each axle was provided with a controller. The controllers were optimized, with regard to necessary sensors, in order to minimize costs. The rear and the front axles were provided with a control unit in order to compute the potential prevailing in the active steering of several axles. It was shown that the passenger car rear axle was the most suitable for coupling stabilization. The experiment was simulated, using a complex coupling model. The developed controller allowed the passenger car trailer to be driven at a speed higher than 150 km per hour.

  6. Thermo-magneto-elastoplastic coupling model of metal magnetic memory testing method for ferromagnetic materials

    Science.gov (United States)

    Shi, Pengpeng; Zhang, Pengcheng; Jin, Ke; Chen, Zhenmao; Zheng, Xiaojing

    2018-04-01

    Metal magnetic memory (MMM) testing (also known as micro-magnetic testing) is a new non-destructive electromagnetic testing method that can diagnose ferromagnetic materials at an early stage by measuring the MMM signal directly on the material surface. Previous experiments have shown that many factors affect MMM signals, in particular, the temperature, the elastoplastic state, and the complex environmental magnetic field. However, the fact that there have been only a few studies of either how these factors affect the signals or the physical coupling mechanisms among them seriously limits the industrial applications of MMM testing. In this paper, a nonlinear constitutive relation for a ferromagnetic material considering the influences of temperature and elastoplastic state is established under a weak magnetic field and is used to establish a nonlinear thermo-magneto-elastoplastic coupling model of MMM testing. Comparing with experimental data verifies that the proposed theoretical model can accurately describe the thermo-magneto-elastoplastic coupling influence on MMM signals. The proposed theoretical model can predict the MMM signals in a complex environment and so is expected to provide a theoretical basis for improving the degree of quantification in MMM testing.

  7. Two-stage continuous process of methyl ester from high free fatty acid mixed crude palm oil using static mixer coupled with high-intensity of ultrasound

    International Nuclear Information System (INIS)

    Somnuk, Krit; Smithmaitrie, Pruittikorn; Prateepchaikul, Gumpon

    2013-01-01

    Highlights: • Mixed crude palm oil was used in the two-step continuous process. • Two-step continuous process was performed using static mixer coupled with ultrasound. • The maximum obtained yield was 92.5 vol.% after the purification process. • The residence time less than 20 s was achieved in ultrasonic reactors. - Abstract: The two-stage continuous process of methyl ester from high free fatty acid (FFA) mixed crude palm oil (MCPO) was performed by using static mixer coupled with high-intensity of ultrasound. The 2 × 1000 W ultrasonic homogenizers were operated at 18 kHz frequency in the 2 × 100 mL continuous reactors. For the first-step, acid-catalyzed esterification was employed with 18 vol.% of methanol, 2.7 vol.% of sulfuric acid, 60 °C of temperature, and 20 L h −1 of MCPO flow rate, for reducing the acid value from 28 mg KOH g −1 to less than 2 mg KOH g −1 . For the second-step, base-catalyzed transesterification was carried out under 18 vol.% of methanol, 8 g KOH L −1 of oil, and 20 L h −1 of esterified oil flow rate at 30 °C. The high yields of esterified oil and crude biodiesel were attained within the residence time of less than 20 s in the ultrasonic reactors. The yields of each stage process were: 103.3 vol.% of esterified oil, 105.4 vol.% of crude biodiesel, and 92.5 vol.% of biodiesel when compared with 100 vol.% MCPO. The quality of the biodiesel meets the specification of biodiesel standard in Thailand

  8. Direct Coupling of Electron Beam Irradiation and Polymer Extrusion for a Continuous Polymer Modification in Molten State

    International Nuclear Information System (INIS)

    Stephan, M.

    2006-01-01

    The new approach of an e-beam initiating of chemical reactions in polymers in molten state results in some innovative results. High temperature, intensive macromolecular mobility and the absence of any crystallinity are some reasons for achieving unexpected structures, processing behaviour and properties changes in such treated thermoplastics and rubbers. Examples are a much more effective crosslinking of polyethylene and special rubbers, long chain branching of polypropylene or a partial crosslinking of polysulfone. Additionally, most of these modification effects are also achievable by a direct coupling of electron beam irradiation and conventional polymer extrusion processing for a continuous polymer modification in molten state. For realizing this unique processing technique a special MOBILE RADIATION FACILITY (MOBRAD1/T) was designed, constructed and manufactured in the IPF Dresden at which a lab-scale single screw extruder was adapted direct to an electron beam accelerator to realize a prompt irradiation of extruded polymer melt profiles before there solidification. Surprisingly, as a result of these short-time-melt reactions some effective and new polymer modification effects were found and will be presented

  9. Directional amplifier in an optomechanical system with optical gain

    Science.gov (United States)

    Jiang, Cheng; Song, L. N.; Li, Yong

    2018-05-01

    Directional amplifiers are crucial nonreciprocal devices in both classical and quantum information processing. Here we propose a scheme for realizing a directional amplifier between optical and microwave fields based on an optomechanical system with optical gain, where an active optical cavity and two passive microwave cavities are coupled to a common mechanical resonator via radiation pressure. The two passive cavities are coupled via hopping interaction to facilitate the directional amplification between the active and passive cavities. We obtain the condition of achieving optical directional amplification and find that the direction of amplification can be controlled by the phase differences between the effective optomechanical couplings. The effects of the gain rate of the active cavity and the effective coupling strengths on the maximum gain of the amplifier are discussed. We show that the noise added to this amplifier can be greatly suppressed in the large cooperativity limit.

  10. Luminescence evolution from alumina ceramic surface before flashover under direct and alternating current voltage in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Su, Guo-Qiang; Wang, Yi-Bo; Song, Bai-Peng; Mu, Hai-Bao, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn; Zhang, Guan-Jun, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Li, Feng; Wang, Meng [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)

    2016-06-15

    The luminescence evolution phenomena from alumina ceramic surface in vacuum under high voltage of direct and alternating current are reported, with the voltage covering a large range from far below to close to the flashover voltage. Its time resolved and spatial distributed behaviors are examined by a photon counting system and an electron-multiplying charge-coupled device (EMCCD) together with a digital camera, respectively. The luminescence before flashover exhibits two stages as voltage increasing, i.e., under a relative low voltage (Stage A), the luminescence is ascribed to radiative recombination of hetero-charges injected into the sample surface layer by Schottky effect; under a higher voltage (Stage B), a stable secondary electron emission process, resulting from the Fowler-Nordheim emission at the cathode triple junction (CTJ), is responsible for the luminescence. Spectrum analysis implies that inner secondary electrons within the surface layer of alumina generated during the SSEE process also participate in the luminescence of Stage B. A comprehensive interpretation of the flashover process is formulated, which might promote a better understanding of flashover issue in vacuum.

  11. Stages of chaotic synchronization.

    Science.gov (United States)

    Tang, D. Y.; Dykstra, R.; Hamilton, M. W.; Heckenberg, N. R.

    1998-09-01

    In an experimental investigation of the response of a chaotic system to a chaotic driving force, we have observed synchronization of chaos of the response system in the forms of generalized synchronization, phase synchronization, and lag synchronization to the driving signal. In this paper we compare the features of these forms of synchronized chaos and study their relations and physical origins. We found that different forms of chaotic synchronization could be interpreted as different stages of nonlinear interaction between the coupled chaotic systems. (c) 1998 American Institute of Physics.

  12. Modelling of the initial stage of the surface discharge development

    International Nuclear Information System (INIS)

    Gibalov, V.; Pietsch, G.

    1998-01-01

    Computer modelling of the initial stage of the surface discharge was performed by solving numerically the coupled continuity, the Poisson and Townsend ionization equations and taking into account the ionization, attachment and detachment processes. The potential distribution at the dielectric surface and at the boundaries which surround the integration region have been calculated with the charge-image method in a 3D approach. In order to eliminate numerical diffusion effects, the solution of the continuity equation was corrected using a flux correction transport routine. At the positive voltage the development of the discharge channel is determined mainly by the shape of the electrode tip. At the negative voltage the following phases of the discharge may be distinguished: the initial phase, the cathode directed streamer phase resulting in the cathode layer formation, and the propagating phase. The physical processes governing each discharge phase are described in detail. (J.U.)

  13. Coupled geochemical and solute transport code development

    International Nuclear Information System (INIS)

    Morrey, J.R.; Hostetler, C.J.

    1985-01-01

    A number of coupled geochemical hydrologic codes have been reported in the literature. Some of these codes have directly coupled the source-sink term to the solute transport equation. The current consensus seems to be that directly coupling hydrologic transport and chemical models through a series of interdependent differential equations is not feasible for multicomponent problems with complex geochemical processes (e.g., precipitation/dissolution reactions). A two-step process appears to be the required method of coupling codes for problems where a large suite of chemical reactions must be monitored. Two-step structure requires that the source-sink term in the transport equation is supplied by a geochemical code rather than by an analytical expression. We have developed a one-dimensional two-step coupled model designed to calculate relatively complex geochemical equilibria (CTM1D). Our geochemical module implements a Newton-Raphson algorithm to solve heterogeneous geochemical equilibria, involving up to 40 chemical components and 400 aqueous species. The geochemical module was designed to be efficient and compact. A revised version of the MINTEQ Code is used as a parent geochemical code

  14. Magnetic shield effect simulation of superconducting film shield covering directly coupled HTS dc-SQUID magnetometer

    International Nuclear Information System (INIS)

    Terauchi, N.; Noguchi, S.; Igarashi, H.

    2011-01-01

    A superconducting film shield over a SQUID ring improves the robustness of the SQUID with respect to magnetic noise. Supercurrent in the SQUID magnetometer and the superconducting film shield were simulated. The superconducting film shield reduces the influence of the external magnetic field on the SQUID ring. An HTS SQUID is a high sensitive magnetic sensor. In recent years, the HTS SQUID is widely used in various applications. In some applications, high robustness with respect to magnetic noise is required to realize stable operation at outside of a magnetic shielding room. The target of this paper is a directly coupled HTS dc-SQUID magnetometer. To enhance the robustness of the SQUID magnetometer, use of a superconducting thin film shield has been proposed. The magnetic field directly penetrating the SQUID ring causes the change of the critical current of Josephson junction, and then the SQUID magnetometer transitions into inoperative state. In order to confirm the magnetic shield effect of the superconducting film shield, electromagnetic field simulation with 3D edge finite element method was performed. To simulate the high temperature superconductor, E-J characteristics and c-axis anisotropy are considered. To evaluate the effect of the superconducting film shield, an external magnetic field which is supposed to be a magnetic noise is applied. From the simulation results, the time transition of the magnetic flux penetrating the SQUID ring is investigated and the effect of the superconducting film shield is confirmed. The amplitude of the magnetic flux penetrating the SQUID ring can be reduced to about one-sixth since the superconducting film shield prevents the magnetic noise from directly penetrating the SQUID ring.

  15. [Dynamic coupling and spatial disparity of economic development and water environmental quality in Songhua River Basin of Jilin Province, Northeast China].

    Science.gov (United States)

    Yang, Li-Hua; Tong, Lian-Jun

    2013-02-01

    By using coupling model, this paper analyzed the relationships between the economic development and water environment quality in Songhua River Basin of Jilin Province from 1991 to 2010. During the study period, both the economic development index and the water environment index in the Basin showed an uptrend, basically in a coordination state. From the perspective of coupling coordination degree, the economic development and the water environment system were in interactive coupling, with the features of complexity, nonlinearity, and time-variation. As a whole, the coupling experienced three stages, i.e., low level stage, antagonistic stage, and breaking-in stage. As for the coupling degree, the coupling of the economic development and the water environment system was in the first quadrant, i.e., at a development stage of basic coordination. From the perspective of spatial disparity, the coupling degree of the economic development and the water environment system was higher in the upper reaches of the Songhua River Basin, including Changchun and Jilin, than in the lower reaches, including Songyuan and Baicheng. The coupling degree was not only significantly positively correlated with regional economic development, but also affected by the links between the regions as well as the industrial structure within the regions. The economic development of the cities in the upper reaches of the Songhua River Basin was obviously higher than that in the lower reaches, and, due to the adopting of more strict and effective measures for environmental protection and pollution emissions reduction, the water environment quality in the upper reaches of the Songhua River Basin was better.

  16. Domain decomposition with local refinement for flow simulation around a nuclear waste disposal site: direct computation versus simulation using code coupling with OCamlP3L

    Energy Technology Data Exchange (ETDEWEB)

    Clement, F.; Vodicka, A.; Weis, P. [Institut National de Recherches Agronomiques (INRA), 78 - Le Chesnay (France); Martin, V. [Institut National de Recherches Agronomiques (INRA), 92 - Chetenay Malabry (France); Di Cosmo, R. [Institut National de Recherches Agronomiques (INRA), 78 - Le Chesnay (France); Paris-7 Univ., 75 (France)

    2003-07-01

    We consider the application of a non-overlapping domain decomposition method with non-matching grids based on Robin interface conditions to the problem of flow surrounding an underground nuclear waste disposal. We show with a simple example how one can refine the mesh locally around the storage with this technique. A second aspect is studied in this paper. The coupling between the sub-domains can be achieved by computing in two ways: either directly (i.e. the domain decomposition algorithm is included in the code that solves the problems on the sub-domains) or using code coupling. In the latter case, each sub-domain problem is solved separately and the coupling is performed by another program. We wrote a coupling program in the functional language Ocaml, using the OcamIP31 environment devoted to ease the parallelism. This at the same time we test the code coupling and we use the natural parallel property of domain decomposition methods. Some simple 2D numerical tests show promising results, and further studies are under way. (authors)

  17. Domain decomposition with local refinement for flow simulation around a nuclear waste disposal site: direct computation versus simulation using code coupling with OCamlP3L

    International Nuclear Information System (INIS)

    Clement, F.; Vodicka, A.; Weis, P.; Martin, V.; Di Cosmo, R.

    2003-01-01

    We consider the application of a non-overlapping domain decomposition method with non-matching grids based on Robin interface conditions to the problem of flow surrounding an underground nuclear waste disposal. We show with a simple example how one can refine the mesh locally around the storage with this technique. A second aspect is studied in this paper. The coupling between the sub-domains can be achieved by computing in two ways: either directly (i.e. the domain decomposition algorithm is included in the code that solves the problems on the sub-domains) or using code coupling. In the latter case, each sub-domain problem is solved separately and the coupling is performed by another program. We wrote a coupling program in the functional language Ocaml, using the OcamIP31 environment devoted to ease the parallelism. This at the same time we test the code coupling and we use the natural parallel property of domain decomposition methods. Some simple 2D numerical tests show promising results, and further studies are under way. (authors)

  18. Double-temperature ratchet model and current reversal of coupled Brownian motors

    Science.gov (United States)

    Li, Chen-Pu; Chen, Hong-Bin; Zheng, Zhi-Gang

    2017-12-01

    On the basis of the transport features and experimental phenomena observed in studies of molecular motors, we propose a double-temperature ratchet model of coupled motors to reveal the dynamical mechanism of cooperative transport of motors with two heads, where the interactions and asynchrony between two motor heads are taken into account. We investigate the collective unidirectional transport of coupled system and find that the direction of motion can be reversed under certain conditions. Reverse motion can be achieved by modulating the coupling strength, coupling free length, and asymmetric coefficient of the periodic potential, which is understood in terms of the effective potential theory. The dependence of the directed current on various parameters is studied systematically. Directed transport of coupled Brownian motors can be manipulated and optimized by adjusting the pulsation period or the phase shift of the pulsation temperature.

  19. Two stage-type railgun accelerator

    International Nuclear Information System (INIS)

    Ogino, Mutsuo; Azuma, Kingo.

    1995-01-01

    The present invention provides a two stage-type railgun accelerator capable of spiking a flying body (ice pellet) formed by solidifying a gaseous hydrogen isotope as a fuel to a thermonuclear reactor at a higher speed into a central portion of plasmas. Namely, the two stage-type railgun accelerator accelerates the flying body spiked from a initial stage accelerator to a portion between rails by Lorentz force generated when electric current is supplied to the two rails by way of a plasma armature. In this case, two sets of solenoids are disposed for compressing the plasma armature in the longitudinal direction of the rails. The first and the second sets of solenoid coils are previously supplied with electric current. After passing of the flying body, the armature formed into plasmas by a gas laser disposed at the back of the flying body is compressed in the longitudinal direction of the rails by a magnetic force of the first and the second sets of solenoid coils to increase the plasma density. A current density is also increased simultaneously. Then, the first solenoid coil current is turned OFF to accelerate the flying body in two stages by the compressed plasma armature. (I.S.)

  20. Direct analysis of formate in human plasma, serum and whole blood by in-line coupling of microdialysis to capillary electrophoresis for rapid diagnosis of methanol poisoning

    OpenAIRE

    Kubáň, P. (Pavel); Boček, P. (Petr)

    2013-01-01

    A microdialytic device was in-line coupled to capillary electrophoresis for direct injection of blood samples. Its performance was demonstrated on rapid analysis of formic acid in various blood samples including serum samples of a patient diagnosed with acute methanol poisoning.

  1. Tomato Yield and Water Use Efficiency - Coupling Effects between Growth Stage Specific Soil Water Deficits

    DEFF Research Database (Denmark)

    Chen, Si; Zhenjiang, Zhou; Andersen, Mathias Neumann

    2015-01-01

    To investigate the sensitivity of tomato yield and water use efficiency (WUE) to soil water content at different growth stages, the central composite rotatable design (CCRD) was employed in a five-factor-five-level pot experiment under regulated deficit irrigation. Two regression models concerning...... the effects of stage-specific soil water content on tomato yield and WUE were established. The results showed that the lowest available soil water (ASW) content (around 28%) during vegetative growth stage (here denoted θ1) resulted in high yield and WUE. Moderate (around 69% ASW) during blooming and fruit...... effects of ASW in two growth stages were between θ2 and θ5, θ3. In both cases a moderate θ2 was a precondition for maximum yield response to increasing θ5 and θ3. Sensitivity analysis revealed that yield was most sensitive to soil water content at fruit maturity (θ5). Numerical inspection...

  2. Final Report DE-SC0006997; PI Sharp; Coupled Biological and Micro-XAS/XRF Analysis of In Situ Uranium Biogeochemical Processes

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Jonathan O. [Colorado School of Mines, Golden, CO (United States)

    2016-03-30

    Project Overview: The impact of the original seed award was substantially increased by leveraging a postdoctoral fellowship (Marie Curie Postdoctoral Fellowship) and parallel funds from (A) synergistic project supported by NSF and (B) with DOE collaborators (PI’s Ranville and Williams) as well as no-cost extension that greatly increased the impact and publications associated with the project. In aligning with SBR priorities, the project’s focus was extended more broadly to explore coupled biogeochemical analysis of metal (im)mobilization processes beyond uranium with a foundation in integrating microbial ecology with geochemical analyses. This included investigations of arsenic and zinc during sulfate reducing conditions in addition to direct microbial reduction of metals. Complimentary work with NSF funding and collaborative DOE interactions further increased the project scope to investigate metal (im)mobilization coupled to biogeochemical perturbations in forest ecosystems with an emphasis on coupled carbon and metal biogeochemistry. In total, the project was highly impactful and resulted in 9 publications and directly supported salary/tuition for 3 graduate students at various stages of their academic careers as well as my promotion to Associate Professor. In going forward, findings provided inspiration for a two subsequent proposals with collaborators at Lawrence Berkeley Laboratory and others that are currently in review (as of March 2016).

  3. A pilot randomized controlled trial of the feasibility of a self-directed coping skills intervention for couples facing prostate cancer: Rationale and design

    Directory of Open Access Journals (Sweden)

    Lambert Sylvie D

    2012-09-01

    Full Text Available Abstract Background Although it is known both patients’ and partners’ reactions to a prostate cancer diagnosis include fear, uncertainty, anxiety and depression with patients’ partners’ reactions mutually determining how they cope with and adjust to the illness, few psychosocial interventions target couples. Those that are available tend to be led by highly trained professionals, limiting their accessibility and long-term sustainability. In addition, it is recognised that patients who might benefit from conventional face-to-face psychosocial interventions do not access these, either by preference or because of geographical or mobility barriers. Self-directed interventions can overcome some of these limitations and have been shown to contribute to patient well-being. This study will examine the feasibility of a self-directed, coping skills intervention for couples affected by cancer, called Coping-Together, and begin to explore its potential impact on couples’ illness adjustment. The pilot version of Coping-Together includes a series of four booklets, a DVD, and a relaxation audio CD. Methods/design In this double-blind, two-group, parallel, randomized controlled trial, 70 couples will be recruited within 4 months of a prostate cancer diagnosis through urology private practices and randomized to: 1 Coping-Together or 2 a minimal ethical care condition. Minimal ethical care condition couples will be mailed information booklets available at the Cancer Council New South Wales and a brochure for the Cancer Council Helpline. The primary outcome (anxiety and additional secondary outcomes (distress, depression, dyadic adjustment, quality of life, illness or caregiving appraisal, self-efficacy, and dyadic and individual coping will be assessed at baseline (before receiving study material and 2 months post-baseline. Intention-to-treat and per protocol analysis will be conducted. Discussion As partners’ distress rates exceed not only population

  4. Computational Aspects of Nuclear Coupled-Cluster Theory

    International Nuclear Information System (INIS)

    Dean, David Jarvis; Hagen, Gaute; Hjorth-Jensen, M.; Papenbrock, T.F.

    2008-01-01

    Coupled-cluster theory represents an important theoretical tool that we use to solve the quantum many-body problem. Coupled-cluster theory also lends itself to computation in a parallel computing environment. In this article, we present selected results from ab initio studies of stable and weakly bound nuclei utilizing computational techniques that we employ to solve coupled-cluster theory. We also outline several perspectives for future research directions in this area.

  5. Analysis of pumping performances in one-stage turbomolecular pump by 3D direct simulation Monte Carlo calculation

    International Nuclear Information System (INIS)

    Sheng Wang; Hisashi Ninokata

    2005-01-01

    The turbomolecular pump (TMP) has been applied in many fields for producing high and ultrahigh vacuum. It works mainly in conditions of free molecular and transitional flow where the mathematical model is the Boltzmann equation. In this paper, direct simulation Monte Carlo (DSMC) method is applied to simulate the one-stage TMP with a 3D analysis in a rotating reference frame. Considering the Coriolis and centrifugal accelerations, the equations about the molecular velocities and position are deduced. The VSS model and NTC collision schemes are used to calculate the intermolecular collisions. The diffuse reflection is employed on the molecular reflection from the surfaces of boundary. The transmission probabilities of gas flow in two opposite flow direction, the relationship between the mass flow rate and the pressure difference, the pumping performances including the maximum compression ratio on different outlet pressures in free molecular flow and transitional flow and the maximum pumping efficiency on different blade angles are calculated. The transmission probabilities are applied to analyze the relationship between the outlet pressure and the maximum pressure ratio. The numerical results show good quantitative agreement with the existing experiment data. (authors)

  6. Altered Coupling between Motion-Related Activation and Resting-State Brain Activity in the Ipsilesional Sensorimotor Cortex after Cerebral Stroke

    Directory of Open Access Journals (Sweden)

    Jianping Hu

    2017-07-01

    Full Text Available Functional connectivity maps using resting-state functional magnetic resonance imaging (rs-fMRI can closely resemble task fMRI activation patterns, suggesting that resting-state brain activity may predict task-evoked activation or behavioral performance. However, this conclusion was mostly drawn upon a healthy population. It remains unclear whether the predictive ability of resting-state brain activity for task-evoked activation would change under different pathological conditions. This study investigated dynamic changes of coupling between patterns of resting-state functional connectivity (RSFC and motion-related activation in different stages of cerebral stroke. Twenty stroke patients with hand motor function impairment were involved. rs-fMRI and hand motion-related fMRI data were acquired in the acute, subacute, and early chronic stages of cerebral stroke on a 3-T magnetic resonance (MR scanner. Sixteen healthy participants were enrolled as controls. For each subject, an activation map of the affected hand was first created using general linear model analysis on task fMRI data, and then an RSFC map was determined by seeding at the peak region of hand motion activation during the intact hand task. We then measured the extent of coupling between the RSFC maps and motion-related activation maps. Dynamic changes of the coupling between the two fMRI maps were estimated using one-way repeated measures analysis of variance across the three stages. Moreover, imaging parameters were correlated with motor performances. Data analysis showed that there were different coupling patterns between motion-related activation and RSFC maps associating with the affected motor regions during the acute, subacute, and early chronic stages of stroke. Coupling strengths increased as the recovery from stroke progressed. Coupling strengths were correlated with hand motion performance in the acute stage, while coupling recovery was negatively correlated with the recovery

  7. [Continuous ethanol fermentation coupled with recycling of yeast flocs].

    Science.gov (United States)

    Wang, Bo; Ge, Xu-Meng; Li, Ning; Bai, Feng-Wu

    2006-09-01

    A continuous ethanol fermentation system composed of three-stage tanks in series coupled with two sedimentation tanks was established. A self-flocculating yeast strain developed by protoplast fusion from Saccharomyces cerevisiae and Schizosaccharomyces pombe was applied. Two-stage enzymatic hydrolysate of corn powder containing 220g/L of reducing sugar, supplemented with 1.5g/L (NH4)2HPO4 and 2.5g/L KH2PO4, was used as the ethanol fermentation substrate and fed into the first fermentor at the dilution rate of 0.057h(-1). The yeast flocs separated by sedimentation were recycled into the first fermentor as two different models: activation-recycle and direct recycle. The quasi-steady states were obtained for both operation models after the fermentation systems experienced short periods of transitions. Activation process helped enhance the performance of ethanol fermentation at the high dilution rates. The broth containing more than 101g/L ethanol, 3.2g/L residual reducing sugar and 7.7g/L residual total sugar was produced. The ethanol productivity was calculated to be 5.77g/(L x h), which increased by more than 70% compared with that achieved in the same tank in series system without recycling of yeast cells.

  8. A micro-coupling for micro mechanical systems

    Science.gov (United States)

    Li, Wei; Zhou, Zhixiong; Zhang, Bi; Xiao, Yunya

    2016-05-01

    The error motions of micro mechanical systems, such as micro-spindles, increase with the increasing of the rotational speed, which not only decreases the rotational accuracy, but also promotes instability and limits the maximum operational speed. One effective way to deal with it is to use micro-flexible couplings between the drive and driven shafts so as to reduce error motions of the driven shaft. But the conventional couplings, such as diaphragm couplings, elastomeric couplings, bellows couplings, and grooved couplings, etc, cannot be directly used because of their large and complicated structures. This study presents a novel micro-coupling that consists of a flexible coupling and a shape memory alloy (SMA)-based clamp for micro mechanical systems. It is monolithic and can be directly machined from a shaft. The study performs design optimization and provides manufacturing considerations, including thermo-mechanical training of the SMA ring for the desired Two-Way-Shape-Memory effect (TWSMe). A prototype micro-coupling and a prototype micro-spindle using the proposed coupling are fabricated and tested. The testing results show that the prototype micro-coupling can bear a torque of above 5 N • mm and an axial force of 8.5 N and be fitted with an SMA ring for clamping action at room temperature (15 °C) and unclamping action below-5 °C. At the same time, the prototype micro-coupling can work at a rotational speed of above 200 kr/min with the application to a high-speed precision micro-spindle. Moreover, the radial runout error of the artifact, as a substitute for the micro-tool, is less than 3 μm while that of turbine shaft is above 7 μm. It can be concluded that the micro-coupling successfully accommodates misalignment errors of the prototype micro-spindle. This research proposes a micro-coupling which is featured with an SMA ring, and it is designed to clamp two shafts, and has smooth transmission, simple assembly, compact structure, zero-maintenance and

  9. Maturation arrest of human oocytes at germinal vesicle stage

    Directory of Open Access Journals (Sweden)

    Zhi Qin Chen

    2010-01-01

    Full Text Available Maturation arrest of human oocytes may occur at various stages of the cell cycle. A total failure of human oocytes to complete meiosis is rarely observed during assisted conception cycles. We describe here a case of infertile couples for whom all oocytes repeatedly failed to mature at germinal vesicle (GV stage during in vitro fertilization/Intra cytoplasmic sperm injection (IVF/ICSI. The patient underwent controlled ovarian stimulation followed by oocyte retrieval and IVF/ICSI. The oocytes were stripped off cumulus cells prior to the ICSI procedure and their maturity status was defined. The oocyte maturation was repeatedly arrested at the GV. Oocyte maturation arrest may be the cause of infertility in this couple. The recognition of oocyte maturation arrest as a specific medical condition may contribute to the characterization of the currently known as "oocyte factor." The cellular and genetic mechanisms causing oocyte maturation arrest should be the subject for further investigation.

  10. Grating-assisted surface acoustic wave directional couplers

    Science.gov (United States)

    Golan, G.; Griffel, G.; Seidman, A.; Croitoru, N.

    1991-07-01

    Physical properties of novel grating-assisted Y directional couplers are examined using the coupled-mode theory. A general formalism for the analysis of the lateral perturbed directional coupler properties is presented. Explicit expressions for waveguide key parameters such as coupling length, grating period, and other structural characterizations, are obtained. The influence of other physical properties such as time and frequency response or cutoff conditions are also analyzed. A plane grating-assisted directional coupler is presented and examined as a basic component in the integrated acoustic technology.

  11. Lessons Learned for the MICE Coupling Solenoid from the MICE Spectrometer Solenoids

    International Nuclear Information System (INIS)

    Green, Michael A.; Wang, Li; Pan, Heng; Wu, Hong; Guo, Xinglong; Li, S.Y.; Zheng, S.X.; Virostek, Steve P.; DeMello, Allen J.; Li, Derun; Trillaud, Frederick; Zisman, Michael S.

    2010-01-01

    Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the first test of the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and its effect on the operation of the HTS leads. The second time the second spectrometer magnet was tested; the cooling to the cold mass was still not adequate. The cryogenic designs of the MICE and MuCOOL coupling magnets are quite different, but the lessons learned from the tests of the spectrometer magnets have affected the design of the coupling magnets.

  12. Chimera states: Effects of different coupling topologies

    Science.gov (United States)

    Bera, Bidesh K.; Majhi, Soumen; Ghosh, Dibakar; Perc, Matjaž

    2017-04-01

    Collective behavior among coupled dynamical units can emerge in various forms as a result of different coupling topologies as well as different types of coupling functions. Chimera states have recently received ample attention as a fascinating manifestation of collective behavior, in particular describing a symmetry breaking spatiotemporal pattern where synchronized and desynchronized states coexist in a network of coupled oscillators. In this perspective, we review the emergence of different chimera states, focusing on the effects of different coupling topologies that describe the interaction network connecting the oscillators. We cover chimera states that emerge in local, nonlocal and global coupling topologies, as well as in modular, temporal and multilayer networks. We also provide an outline of challenges and directions for future research.

  13. Numerical analysis on a four-stage looped thermoacoustic Stirling power generator for low temperature waste heat

    International Nuclear Information System (INIS)

    Wang, Kai; Qiu, Limin

    2017-01-01

    Highlights: • Four-stage looped thermoacoustic power generator for waste heat is studied. • Coupling position is found to have remarkable effects on performance. • Better efficiency is available when coupled near the cold ends of the cores. • The influence of the regenerator position on the efficiency is weak. • Matching between the acoustic impedances of engine and alternator is important. - Abstract: Recent developments in thermoacoustic technologies have demonstrated that multi-stage looped thermoacoustic Stirling engine would be a promising option for harvesting waste heat. Previous studies on multi-stage looped thermoacoustic systems were mainly focused on heat-driven refrigeration or heat pumping, while much fewer work were done on power generations, especially those for recovering low temperature heat. In this work, a four-stage looped thermoacoustic Stirling power generator for generating electricity from low temperature waste heat at 300 °C is systematically studied. A numerical model is built and then validated on an experimental four-stage looped thermoacoustic Stirling engine. On the basis of the validated model, the effects of the coupling position for the linear alternators and the regenerator position on the acoustic characteristics and performances of the power generation system are numerically investigated. The distributions of the acoustic fields along the loop, including the pressure amplitude, volume flow rate, phase angle, specific acoustic impedance and acoustic power, are presented and analysed for three representative coupling modes. Superior efficiency is achieved when the linear alternators are coupled near the cold ends of the thermoacoustic cores on the resonators, while more electric power is generated at the hot ends. The worst performance is expected when the linear alternators are connected at the middle of the resonators. The underling mechanisms are further explained detailedly by analysing the characteristics of the

  14. Two-Stage Centrifugal Fan

    Science.gov (United States)

    Converse, David

    2011-01-01

    Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

  15. Direct coupling of a genome-scale microbial in silico model and a groundwater reactive transport model

    International Nuclear Information System (INIS)

    Fang, Yilin; Scheibe, Timothy D.; Mahadevan, Radhakrishnan; Garg, Srinath; Long, Philip E.; Lovley, Derek R.

    2011-01-01

    The activity of microorganisms often plays an important role in dynamic natural attenuation or engineered bioremediation of subsurface contaminants, such as chlorinated solvents, metals, and radionuclides. To evaluate and/or design bioremediated systems, quantitative reactive transport models are needed. State-of-the-art reactive transport models often ignore the microbial effects or simulate the microbial effects with static growth yield and constant reaction rate parameters over simulated conditions, while in reality microorganisms can dynamically modify their functionality (such as utilization of alternative respiratory pathways) in response to spatial and temporal variations in environmental conditions. Constraint-based genome-scale microbial in silico models, using genomic data and multiple-pathway reaction networks, have been shown to be able to simulate transient metabolism of some well studied microorganisms and identify growth rate, substrate uptake rates, and byproduct rates under different growth conditions. These rates can be identified and used to replace specific microbially-mediated reaction rates in a reactive transport model using local geochemical conditions as constraints. We previously demonstrated the potential utility of integrating a constraint based microbial metabolism model with a reactive transport simulator as applied to bioremediation of uranium in groundwater. However, that work relied on an indirect coupling approach that was effective for initial demonstration but may not be extensible to more complex problems that are of significant interest (e.g., communities of microbial species, multiple constraining variables). Here, we extend that work by presenting and demonstrating a method of directly integrating a reactive transport model (FORTRAN code) with constraint-based in silico models solved with IBM ILOG CPLEX linear optimizer base system (C library). The models were integrated with BABEL, a language interoperability tool. The

  16. 3-D Modelling of Electromagnetic, Thermal, Mechanical and Metallurgical Couplings in Metal Forming Processes

    International Nuclear Information System (INIS)

    Chenot, Jean-Loup; Bay, Francois

    2007-01-01

    The different stages of metal forming processes often involve - beyond the mechanical deformations processes - other physical coupled problems, such as heat transfer, electromagnetism or metallurgy. The purpose of this paper is to focus on problems involving electromagnetic couplings. After a brief recall on electromagnetic modeling, we shall then focus on induction heating processes and present some results regarding heat transfer, as well as mechanical couplings. A case showing coupling for metallurgic microstructure evolution will conclude this paper

  17. Treating couples recovering from infidelity: an integrative approach.

    Science.gov (United States)

    Gordon, Kristina Coop; Baucom, Donald H; Snyder, Douglas K

    2005-11-01

    Infidelity is one of the most difficult problems to address in couple therapy, most likely because it involves a traumatic relationship event that alters the ways in which couples process information about each other and established behavioral patterns. We present a three-stage treatment designed to address the cognitive, behavioral, and emotional sequelae of affairs that integrates cognitive-behavioral and insight-oriented strategies with the literatures on traumatic response and forgiveness. A case study with pretreatment, posttreatment, and 6-month follow-up data is presented to illustrate the treatment methods.

  18. Coupled fast-thermal system at the 'RB' nuclear reactor

    International Nuclear Information System (INIS)

    Pesic, M.

    1987-04-01

    The results of the analyses of the possibility of the coupled fast-thermal system (CFTS) design at the 'RB' nuclear reactor are shown. As the proof of the theoretical analyses the first stage CFTS-1 has been designed, realized, and tested. The excellent agreement between the results of the CFTS-1 studies and the theoretical predictions opens a straight way to the second, the final stage - realization of the designed CFST at the 'RB' nuclear reactor. (author)

  19. String dynamics at strong coupling

    International Nuclear Information System (INIS)

    Hull, C.M.

    1996-01-01

    The dynamics of superstring, supergravity and M-theories and their compactifications are probed by studying the various perturbation theories that emerge in the strong and weak-coupling limits for various directions in coupling constant space. The results support the picture of an underlying non-perturbative theory that, when expanded perturbatively in different coupling constants, gives different perturbation theories, which can be perturbative superstring theories or superparticle theories. The p-brane spectrum is considered in detail and a criterion found to establish which p-branes govern the strong-coupling dynamics. In many cases there are competing conjectures in the literature, and this analysis decides between them. In other cases, new results are found. The chiral 6-dimensional theory resulting from compactifying the type IIB string on K 3 is studied in detail and it is found that certain strong-coupling limits appear to give new theories, some of which hint at the possibility of a 12-dimensional origin. (orig.)

  20. Sleep and caregiving : sleeping practices of couples facing neurodegenerative diseases

    OpenAIRE

    Casini , Elisa

    2017-01-01

    This doctoral dissertation in sociology examines the sleep practices of ageing couples confronted with neuro-degenerative conditions. It aims to understand the time- and space-related aspects of these sleep practices, so central to couples’ lives, throughout the different stages of illness, and places particular emphasis on gender-based relations. Thirty couples were interviewed in their homes, 12 of whom were affected by Lewy Body Dementia and 18 by Alzheimer’s Disease. Empirical methods suc...

  1. Cooperation and competition between two symmetry breakings in a coupled ratchet

    Science.gov (United States)

    Li, Chen-Pu; Chen, Hong-Bin; Fan, Hong; Xie, Ge-Ying; Zheng, Zhi-Gang

    2018-03-01

    We investigate the collective mechanism of coupled Brownian motors in a flashing ratchet in the presence of coupling symmetry breaking and space symmetry breaking. The dependences of directed current on various parameters are extensively studied in terms of numerical simulations and theoretical analysis. Reversed motion can be achieved by modulating multiple parameters including the spatial asymmetry coefficient, the coupling asymmetry coefficient, the coupling free length and the coupling strength. The dynamical mechanism of these transport properties can be reasonably explained by the effective potential theory and the cooperation or competition between two symmetry breakings. Moreover, adjusting the Gaussian white noise intensity, which can induce weak reversed motion under certain condition, can optimize and manipulate the directed transport of the ratchet system.

  2. Receptor oligomerization in family B1 of G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Roed, Sarah Norklit; Ørgaard, Anne; Jørgensen, Rasmus

    2012-01-01

    , the glucagon receptor, and the receptors for parathyroid hormone (PTHR1 and PTHR2). The dysregulation of several family B1 receptors is involved in diseases, such as diabetes, chronic inflammation, and osteoporosis which underlines the pathophysiological importance of this GPCR subfamily. In spite of this......, investigation of family B1 receptor oligomerization and especially its pharmacological importance is still at an early stage. Even though GPCR oligomerization is a well-established phenomenon, there is a need for more investigations providing a direct link between these interactions and receptor functionality......The superfamily of the seven transmembrane G-protein-coupled receptors (7TM/GPCRs) is the largest family of membrane-associated receptors. GPCRs are involved in the pathophysiology of numerous human diseases, and they constitute an estimated 30-40% of all drug targets. During the last two decades...

  3. Two-step two-stage fission gas release model

    International Nuclear Information System (INIS)

    Kim, Yong-soo; Lee, Chan-bock

    2006-01-01

    Based on the recent theoretical model, two-step two-stage model is developed which incorporates two stage diffusion processes, grain lattice and grain boundary diffusion, coupled with the two step burn-up factor in the low and high burn-up regime. FRAPCON-3 code and its in-pile data sets have been used for the benchmarking and validation of this model. Results reveals that its prediction is in better agreement with the experimental measurements than that by any model contained in the FRAPCON-3 code such as ANS 5.4, modified ANS5.4, and Forsberg-Massih model over whole burn-up range up to 70,000 MWd/MTU. (author)

  4. Analysis of the coupling coordination between transportation infrastructure investment and economic development in Hubei province

    Directory of Open Access Journals (Sweden)

    Wenxia Zhai

    2017-06-01

    Full Text Available The relationship between transportation infrastructure investment and regional economic growth has been the focus of domestic and foreign academic research. Using the models of coupling degree and coupling coordination degree, this paper calculated the coupling degree and coupling coordination degree between the comprehensive level of transportation infrastructure investment and economic development in Hubei province and its 17 cities, and analyzed its temporal and spatial characteristics. The result showed that, from 2001 to 2013, the coupling and coupling coordination between transportation infrastructure investment and economic development in Hubei province were on a steady rise in the time sequence characteristics. It experienced the upgrade from the uncoordinated – nearly uncoordinated – barely coordinated – intermediately coordinated stages. In the year of 2013, the coupling and coupling coordination of transportation infrastructure investment and economic development in the 17 prefecture-level cities of Hubei Province showed a very uneven spatial difference. Good coordination, primary coordination, barely coordinate, and barely in-coordination are distributed in the province. The average coordination degree of the 17 prefecture-level cities in Hubei is relatively low, and there is a negative tend to expand the difference. This study has confirmed the relationship between transportation infrastructure investment and the economic development to be in an interactive coupling and coordination, but in different regions and different stages, the degree of coordination has obvious spatial and temporal differences.

  5. Direct determination of trace rare earth elements in ancient porcelain samples with slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Xiang Guoqiang; Jiang Zucheng; He Man; Hu Bin

    2005-01-01

    A method for the direct determination of trace rare earth elements in ancient porcelain samples by slurry sampling fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry was developed with the use of polytetrafluoroethylene as fluorinating reagent. It was found that Si, as a main matrix element in ancient porcelain sample, could be mostly removed at the ashing temperature of 1200 deg. C without considerable losses of the analytes. However, the chemical composition of ancient porcelain sample is very complicated, which makes the influences resulting from other matrix elements not be ignored. Therefore, the matrix effect of ancient porcelain sample was also investigated, and it was found that the matrix effect is obvious when the matrix concentration was larger than 0.8 g l -1 . The study results of particle size effect indicated that when the sample particle size was less than 0.057 mm, the particle size effect is negligible. Under the optimized operation conditions, the detection limits for rare earth elements by fluorinating electrothermal vaporization inductively coupled plasma mass spectrometry were 0.7 ng g -1 (Eu)-33.3 ng g -1 (Nd) with the precisions of 4.1% (Yb)-10% (La) (c = 1 μg l -1 , n = 9). The proposed method was used to directly determine the trace rare earth elements in ancient porcelain samples produced in different dynasty (Sui, Ming and Qing), and the analytical results are satisfactory

  6. Piezoelectric power converter with bi-directional power transfer

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a bi-directional piezoelectric power converter com¬ prising a piezoelectric transformer. The piezoelectric transformer comprises an input electrode electrically coupled to a primary section of the piezoelectric transformer and an output electrode electrically...... coupled to an output section of the piezoelectric transformer to provide a transformer output signal. A bi-directional switching circuit is coupled between the output electrode and a DC or AC output voltage of the power converter. Forward and reverse current conducting periods of the bi......, a reverse current is conducted through the bi-directional switching circuit from the DC or AC output voltage to the output electrode to discharge the DC or AC output voltage and return power to the primary section of the piezoelectric transformer....

  7. An experimentally validated simulation model for a four-stage spray dryer

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2017-01-01

    mathematical model is an index-1 differential algebraic equation (DAE) model with 12 states, 9 inputs, 8 disturbances, and 30 parameters. The parameters in the model are identified from well-excited experimental data obtained from the industrialtype spray dryer. The simulated outputs ofthe model are validated...... is divided into four consecutive stages: a primary spray drying stage, two heated fluid bed stages, and a cooling fluid bed stage. Each of these stages in the model is assumed ideally mixed and the dynamics are described by mass- and energy balances. These balance equations are coupled with constitutive...... equations such as a thermodynamic model, the water evaporation rate, the heat transfer rates, and an equation for the stickiness of the powder (glass transition temperature). Laboratory data is used to model the equilibrium moisture content and the glass transition temperature of the powder. The resulting...

  8. Directly connected series coupled HTPEM fuel cell stacks to a Li-ion battery DC bus for a fuel cell electrical vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    The work presented in this paper examines the use of pure hydrogen fuelled high temperature polymer electrolyte membrane (HTPEM) fuel cell stacks in an electrical car, charging a Li-ion battery pack. The car is equipped with two branches of two series coupled 1 kW fuel cell stacks which...... are connected directly parallel to the battery pack during operation. This enables efficient charging of the batteries for increased driving range. With no power electronics used, the fuel cell stacks follow the battery pack voltage, and charge the batteries passively. This saves the electrical and economical...... losses related to these components and their added system complexity. The new car battery pack consists of 23 Li-ion battery cells and the charging and discharging are monitored by a battery management system (BMS) which ensures safe operating conditions for the batteries. The direct connection...

  9. Grid Compatibility of Variable Speed Wind Turbines with Directly Coupled Synchronous Generator and Hydro-Dynamically Controlled Gearbox

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.; Poeller, M. [DIgSILENT GmbH, 72810 Gomaringen (Germany); Basteck, A.; Tilscher, M.; Pfister, J. [Voith Turbo GmbH and Co. KG, 74564 Crailsheim (Germany)

    2006-07-01

    This paper analyzes grid integration aspects of a new type of variable-speed wind turbine, the directly coupled synchronous generator with hydro-dynamically controlled gearbox. In contrast to existing wind generators using synchronous generators, the generator of this concept is directly connected to the AC grid, without the application of any power electronics converter. Variable speed operation of the turbine is mechanically achieved by a gear box with continuously controllable variable gear box ratio. For this purpose, a detailed dynamic model of a 2 MW wind turbine with a Voith WinDrive has been implemented using the modelling environment of the simulation software DIgSILENT PowerFactory. For investigating grid compatibility aspects of this new wind generator concept, a model of a 50 MW wind farm, with typical layout, based on 25 wind turbines of the 2 MW-class has been analyzed. This paper focuses on the compatibility of the new concept with existing connection standards, such as the E.ON grid code. Of special interest are typical stability phenomena of synchronous generators, such as transient and oscillatory stability as well as power quality issues like voltage flicker. The results of stability studies are presented and possible advantages of the new concept with special focus on offshore applications are discussed.

  10. Extremely high-brightness kW-class fiber coupled diode lasers with wavelength stabilization

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Glenn, John D.

    2011-06-01

    TeraDiode has produced ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 1,040 W from a 200 μm core diameter, 0.18 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 18 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. The laser has been used to demonstrate laser cutting and welding of steel sheet metal up to 6.65 mm thick. Higher brightness fiber-coupled diode lasers, including a module with 418 W of power coupled to a 100 μm, 0.15 NA fiber, have also been demonstrated.

  11. The μ-RWELL: A compact, spark protected, single amplification-stage MPGD

    Science.gov (United States)

    Poli Lener, M.; Bencivenni, G.; de Olivera, R.; Felici, G.; Franchino, S.; Gatta, M.; Maggi, M.; Morello, G.; Sharma, A.

    2016-07-01

    In this work we present two innovative architectures of resistive MPGDs based on the WELL-amplification concept: - the micro-Resistive WELL (μ-RWELL) is a compact spark-protected single amplification-stage Micro-Pattern Gas Detector (MPGD). The amplification stage, realized with a structure very similar to a GEM foil (called WELL), is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new architecture, showing an excellent space resolution, 50 μm, is a very compact device, robust against discharges and exhibiting a large gain (>104), simple to construct and easy for engineering and then suitable for large area tracking devices as well as digital calorimeters. - the Fast Timing Micro-pattern (FTM): a new device with an architecture based on a stack of several coupled full-resistive layers where drift and multiplication stages (WELL type) alternate in the structure. The signals from each multiplication stage can be read out from any external readout boards through the capacitive couplings, providing a signal with a gain of 104-105. The main advantage of this new device is the improvement of the timing provided by the competition of the ionization processes in the different drift regions, which can be exploited for fast timing at the high luminosity accelerators (e.g. HL-LHC upgrade) as well as for applications like medical imaging.

  12. Dynamics of directional coupling underlying spike-wave discharges

    NARCIS (Netherlands)

    Sysoeva, M.V.; Luttjohann, A.K.; Luijtelaar, E.L.J.M. van; Sysoev, I.V.

    2016-01-01

    Purpose: Spike and wave discharges (SWDs), generated within cortico-thalamo-cortical networks, are the electroencephalographic biomarker of absence epilepsy. The current work aims to identify mechanisms of SWD initiation, maintenance and termination by the analyses of dynamics and directionality of

  13. Effect of water electrolysis temperature of hydrogen production system using direct coupling photovoltaic and water electrolyzer

    Directory of Open Access Journals (Sweden)

    Tetsuhiko Maeda

    2016-01-01

    Full Text Available We propose control methods of a photovoltaic (PV-water electrolyzer (ELY system that generates hydrogen by controlling the number of ELY cells. The advantage of this direct coupling between PV and ELY is that the power loss of DC/DC converter is avoided. In this study, a total of 15 ELY cells are used. In the previous researches, the electrolyzer temperature was constantly controlled with a thermostat. Actually, the electrolyzer temperature is decided by the balance of the electrolysis loss and the heat loss to the outside. Here, the method to control the number of ELY cells was investigated. Maximum Power Point Tracking efficiency of more than 96% was achieved without ELY temperature control. Furthermore we construct a numerical model taking into account of ELY temperature. Using this model, we performed a numerical simulation of 1-year. Experimental data and the simulation results shows the validity of the proposed control method.

  14. DFT Investigation of the Palladium-Catalyzed Ene-Yne Coupling

    DEFF Research Database (Denmark)

    Henriksen, Signe Teuber; Tanner, David Ackland; Skrydstrup, T.

    2010-01-01

    ). Concerning chemoselectivity, the calculations also clarify why the ene-yne coupling is able to dominate over plausible alternative reaction pathways such as alkene homocoupiing and alkyne polymerization. The role of the phosphine ligand at various stages of the catalytic cycle has also been delineated....

  15. Rapid Determination of Clenbuterol in Pork by Direct Immersion Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Ye, Diru; Wu, Susu; Xu, Jianqiao; Jiang, Ruifen; Zhu, Fang; Ouyang, Gangfeng

    2016-02-01

    Direct immersion solid-phase microextraction (DI-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was developed for rapid analysis of clenbuterol in pork for the first time. In this work, a low-cost homemade 44 µm polydimethylsiloxane (PDMS) SPME fiber was employed to extract clenbuterol in pork. After extraction, derivatization was performed by suspending the fiber in the headspace of the 2 mL sample vial saturated with a vapor of 100 µL hexamethyldisilazane. Lastly, the fiber was directly introduced to GC-MS for analysis. All parameters that influenced absorption (extraction time), derivatization (derivatization reagent, time and temperature) and desorption (desorption time) were optimized. Under optimized conditions, the method offered a wide linear range (10-1000 ng g(-1)) and a low detection limit (3.6 ng g(-1)). Finally, the method was successfully applied in the analysis of pork from the market, and recoveries of the method for spiked pork were 97.4-105.7%. Compared with the traditional solvent extraction method, the proposed method was much cheaper and fast. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Selective sp3 C–H alkylation via polarity-match-based cross-coupling

    Science.gov (United States)

    Le, Chip; Liang, Yufan; Evans, Ryan W.; Li, Ximing; MacMillan, David W. C.

    2017-01-01

    The functionalization of carbon–hydrogen (C–H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence1. Although many C–H functionalization reactions involve C(sp3)–C(sp2) coupling, there is a growing demand for C–H alkylation reactions, wherein sp3 C–H bonds are replaced with sp3 C–alkyl groups. Here we describe a polarity-match-based selective sp3 C–H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C–H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl–alkyl fragment coupling. The sp3 C–H alkylation is highly selective for the α-C–H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry. PMID:28636596

  17. Selective sp3 C-H alkylation via polarity-match-based cross-coupling.

    Science.gov (United States)

    Le, Chip; Liang, Yufan; Evans, Ryan W; Li, Ximing; MacMillan, David W C

    2017-07-06

    The functionalization of carbon-hydrogen (C-H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence. Although many C-H functionalization reactions involve C(sp 3 )-C(sp 2 ) coupling, there is a growing demand for C-H alkylation reactions, wherein sp 3 C-H bonds are replaced with sp 3 C-alkyl groups. Here we describe a polarity-match-based selective sp 3 C-H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C-H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl-alkyl fragment coupling. The sp 3 C-H alkylation is highly selective for the α-C-H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry.

  18. Selective sp3 C-H alkylation via polarity-match-based cross-coupling

    Science.gov (United States)

    Le, Chip; Liang, Yufan; Evans, Ryan W.; Li, Ximing; MacMillan, David W. C.

    2017-07-01

    The functionalization of carbon-hydrogen (C-H) bonds is one of the most attractive strategies for molecular construction in organic chemistry. The hydrogen atom is considered to be an ideal coupling handle, owing to its relative abundance in organic molecules and its availability for functionalization at almost any stage in a synthetic sequence. Although many C-H functionalization reactions involve C(sp3)-C(sp2) coupling, there is a growing demand for C-H alkylation reactions, wherein sp3 C-H bonds are replaced with sp3 C-alkyl groups. Here we describe a polarity-match-based selective sp3 C-H alkylation via the combination of photoredox, nickel and hydrogen-atom transfer catalysis. This methodology simultaneously uses three catalytic cycles to achieve hydridic C-H bond abstraction (enabled by polarity matching), alkyl halide oxidative addition, and reductive elimination to enable alkyl-alkyl fragment coupling. The sp3 C-H alkylation is highly selective for the α-C-H of amines, ethers and sulphides, which are commonly found in pharmaceutically relevant architectures. This cross-coupling protocol should enable broad synthetic applications in de novo synthesis and late-stage functionalization chemistry.

  19. Exact solutions of some coupled nonlinear diffusion-reaction ...

    Indian Academy of Sciences (India)

    certain coupled diffusion-reaction (D-R) equations of very general nature. In recent years, various direct methods have been proposed to find the exact solu- tions not only of nonlinear partial differential equations but also of their coupled versions. These methods include unified ansatz approach [3], extended hyperbolic func ...

  20. Quantitative real-time monitoring of multi-elements in airborne particulates by direct introduction into an inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Suzuki, Yoshinari; Sato, Hikaru; Hiyoshi, Katsuhiro; Furuta, Naoki

    2012-01-01

    A new calibration system for real-time determination of trace elements in airborne particulates was developed. Airborne particulates were directly introduced into an inductively coupled plasma mass spectrometer, and the concentrations of 15 trace elements were determined by means of an external calibration method. External standard solutions were nebulized by an ultrasonic nebulizer (USN) coupled with a desolvation system, and the resulting aerosol was introduced into the plasma. The efficiency of sample introduction via the USN was calculated by two methods: (1) the introduction of a Cr standard solution via the USN was compared with introduction of a Cr(CO) 6 standard gas via a standard gas generator and (2) the aerosol generated by the USN was trapped on filters and then analyzed. The Cr introduction efficiencies obtained by the two methods were the same, and the introduction efficiencies of the other elements were equal to the introduction efficiency of Cr. Our results indicated that our calibration method for introduction efficiency worked well for the 15 elements (Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Sn, Sb, Ba, Tl and Pb). The real-time data and the filter-collection data agreed well for elements with low-melting oxides (V, Co, As, Mo, Sb, Tl, and Pb). In contrast, the real-time data were smaller than the filter-collection data for elements with high-melting oxides (Ti, Cr, Mn, Ni, Cu, Zn, Sn, and Ba). This result implies that the oxides of these 8 elements were not completely fused, vaporized, atomized, and ionized in the initial radiation zone of the inductively coupled plasma. However, quantitative real-time monitoring can be realized after correction for the element recoveries which can be calculated from the ratio of real-time data/filter-collection data. - Highlights: ► APs were directly introduced into ICP-MS and real-time analysis was performed. ► The real-time data were calibrated by a multi-element standard solution from USN. ► During real

  1. Collisionless coupling of a high- β expansion to an ambient, magnetized plasma. II. Experimental fields and measured momentum coupling

    Science.gov (United States)

    Bonde, Jeffrey; Vincena, Stephen; Gekelman, Walter

    2018-04-01

    The momentum coupled to a magnetized, ambient argon plasma from a high- β, laser-produced carbon plasma is examined in a collisionless, weakly coupled limit. The total electric field was measured by separately examining the induced component associated with the rapidly changing magnetic field of the high- β (kinetic β˜106), expanding plasma and the electrostatic component due to polarization of the expansion. Their temporal and spatial structures are discussed and their effect on the ambient argon plasma (thermal β˜10-2) is confirmed with a laser-induced fluorescence diagnostic, which directly probed the argon ion velocity distribution function. For the given experimental conditions, the electrostatic field is shown to dominate the interaction between the high- β expansion and the ambient plasma. Specifically, the expanding plasma couples energy and momentum into the ambient plasma by pulling ions inward against the flow direction.

  2. Early disrupted neurovascular coupling and changed event level hemodynamic response function in type 2 diabetes: an fMRI study.

    Science.gov (United States)

    Duarte, João V; Pereira, João M S; Quendera, Bruno; Raimundo, Miguel; Moreno, Carolina; Gomes, Leonor; Carrilho, Francisco; Castelo-Branco, Miguel

    2015-10-01

    Type 2 diabetes (T2DM) patients develop vascular complications and have increased risk for neurophysiological impairment. Vascular pathophysiology may alter the blood flow regulation in cerebral microvasculature, affecting neurovascular coupling. Reduced fMRI signal can result from decreased neuronal activation or disrupted neurovascular coupling. The uncertainty about pathophysiological mechanisms (neurodegenerative, vascular, or both) underlying brain function impairments remains. In this cross-sectional study, we investigated if the hemodynamic response function (HRF) in lesion-free brains of patients is altered by measuring BOLD (Blood Oxygenation Level-Dependent) response to visual motion stimuli. We used a standard block design to examine the BOLD response and an event-related deconvolution approach. Importantly, the latter allowed for the first time to directly extract the true shape of HRF without any assumption and probe neurovascular coupling, using performance-matched stimuli. We discovered a change in HRF in early stages of diabetes. T2DM patients show significantly different fMRI response profiles. Our visual paradigm therefore demonstrated impaired neurovascular coupling in intact brain tissue. This implies that functional studies in T2DM require the definition of HRF, only achievable with deconvolution in event-related experiments. Further investigation of the mechanisms underlying impaired neurovascular coupling is needed to understand and potentially prevent the progression of brain function decrements in diabetes.

  3. Predicting the Coupling Properties of Axially-Textured Materials

    Science.gov (United States)

    Fuentes-Cobas, Luis E.; Muñoz-Romero, Alejandro; Montero-Cabrera, María E.; Fuentes-Montero, Luis; Fuentes-Montero, María E.

    2013-01-01

    A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones. PMID:28788370

  4. Predicting the Coupling Properties of Axially-Textured Materials

    Directory of Open Access Journals (Sweden)

    María E. Fuentes-Montero

    2013-10-01

    Full Text Available A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones.

  5. Direct Structural Identification of Gas Induced Gate-Opening Coupled with Commensurate Adsorption in a Microporous Metal-Organic Framework.

    Science.gov (United States)

    Banerjee, Debasis; Wang, Hao; Plonka, Anna M; Emge, Thomas J; Parise, John B; Li, Jing

    2016-08-08

    Gate-opening is a unique and interesting phenomenon commonly observed in flexible porous frameworks, where the pore characteristics and/or crystal structures change in response to external stimuli such as adding or removing guest molecules. For gate-opening that is induced by gas adsorption, the pore-opening pressure often varies for different adsorbate molecules and, thus, can be applied to selectively separate a gas mixture. The detailed understanding of this phenomenon is of fundamental importance to the design of industrially applicable gas-selective sorbents, which remains under investigated due to the lack of direct structural evidence for such systems. We report a mechanistic study of gas-induced gate-opening process of a microporous metal-organic framework, [Mn(ina)2 ] (ina=isonicotinate) associated with commensurate adsorption, by a combination of several analytical techniques including single crystal X-ray diffraction, in situ powder X-ray diffraction coupled with differential scanning calorimetry (XRD-DSC), and gas adsorption-desorption methods. Our study reveals that the pronounced and reversible gate opening/closing phenomena observed in [Mn(ina)2 ] are coupled with a structural transition that involves rotation of the organic linker molecules as a result of interaction of the framework with adsorbed gas molecules including carbon dioxide and propane. The onset pressure to open the gate correlates with the extent of such interaction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Coupled vibrations in horizontal and vertical rotor-bearings systems

    OpenAIRE

    Luneno, Jean-Claude

    2010-01-01

    For dynamical systems having several degrees of freedom, motion in one direction can induce motion in the other and/or vice versa. This means that there is a certain coupling between these two motions. Coupling can in some cases be a source of instability that causes self-excited vibrations in rotating machinery. In modeling hydropower rotors, couplings other than those that are the result of gyroscopic effect are normally not considered. This is due to the complexity of the reasons for coupl...

  7. Coupled vibrations in horizontal and vertical rotor-bearing systems

    OpenAIRE

    Luneno, Jean-Claude

    2011-01-01

    For dynamical systems having several degrees of freedom, motion in one direction can induce motion in the other. This means that there is a certain coupling between these two motions. Coupling can in some cases be a source of instability that causes self-excited vibrations in rotating machinery. In classical modeling of rotor systems, couplings other than those that are the result of gyroscopic effect are normally not considered. This is due to thecomplexity of the reasons for coupling which ...

  8. Correlated Coulomb Drag in Capacitively Coupled Quantum-Dot Structures.

    Science.gov (United States)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka

    2016-05-13

    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs)-a bias-driven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach that accounts for higher-order tunneling (cotunneling) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechanism driven by nonlocal multielectron cotunneling processes. Our theory establishes the conditions for a nonzero drag as well as the direction of the drag current in terms of microscopic system parameters. Interestingly, the direction of the drag current is not determined by the drive current, but by an interplay between the energy-dependent lead couplings. Studying the drag mechanism in a graphene-based CQD heterostructure, we show that the predictions of our theory are consistent with recent experiments on Coulomb drag in CQD systems.

  9. Plant specification of a generic human-error data through a two-stage Bayesian approach

    International Nuclear Information System (INIS)

    Heising, C.D.; Patterson, E.I.

    1984-01-01

    Expert judgement concerning human performance in nuclear power plants is quantitatively coupled with actuarial data on such performance in order to derive plant-specific human-error rate probability distributions. The coupling procedure consists of a two-stage application of Bayes' theorem to information which is grouped by type. The first information type contains expert judgement concerning human performance at nuclear power plants in general. Data collected on human performance at a group of similar plants forms the second information type. The third information type consists of data on human performance in a specific plant which has the same characteristics as the group members. The first and second information types are coupled in the first application of Bayes' theorem to derive a probability distribution for population performance. This distribution is then combined with the third information type in a second application of Bayes' theorem to determine a plant-specific human-error rate probability distribution. The two stage Bayesian procedure thus provides a means to quantitatively couple sparse data with expert judgement in order to obtain a human performance probability distribution based upon available information. Example calculations for a group of like reactors are also given. (author)

  10. Models for electromagnetic coupling of lightning onto multiconductor cables in underground cavities

    Science.gov (United States)

    Higgins, Matthew Benjamin

    This dissertation documents the measurements, analytical modeling, and numerical modeling of electromagnetic transfer functions to quantify the ability of cloud-to-ground lightning strokes (including horizontal arc-channel components) to couple electromagnetic energy onto multiconductor cables in an underground cavity. Measurements were performed at the Sago coal mine located near Buckhannon, WV. These transfer functions, coupled with mathematical representations of lightning strokes, are then used to predict electric fields within the mine and induced voltages on a cable that was left abandoned in the sealed area of the Sago mine. If voltages reached high enough levels, electrical arcing could have occurred from the abandoned cable. Electrical arcing is known to be an effective ignition source for explosive gas mixtures. Two coupling mechanisms were measured: direct and indirect drive. Direct coupling results from the injection or induction of lightning current onto metallic conductors such as the conveyors, rails, trolley communications cable, and AC power shields that connect from the outside of the mine to locations deep within the mine. Indirect coupling results from electromagnetic field propagation through the earth as a result of a cloud-to-ground lightning stroke or a long, low-altitude horizontal current channel from a cloud-to-ground stroke. Unlike direct coupling, indirect coupling does not require metallic conductors in a continuous path from the surface to areas internal to the mine. Results from the indirect coupling measurements and analysis are of great concern. The field measurements, modeling, and analysis indicate that significant energy can be coupled directly into the sealed area of the mine. Due to the relatively low frequency content of lightning (extremely well with analytical and computational models developed for the Sago site which take into account measured soil properties.

  11. Enhancement of thermoelectric figure-of-merit in laterally-coupled nanowire arrays

    International Nuclear Information System (INIS)

    Zhang, Yiqun; Shi, Yi; Pu, Lin; Wang, Junzhuan; Pan, Lijia; Zheng, Youdou

    2011-01-01

    A high ZT value is predicted in laterally-coupled nanowire arrays. The quantum confinement and coupling of electrons are considered in the framework of effective-mass envelope-function theory. The boundary scattering on phonons is also taken into account. The thermoelectric properties benefit from the large Seebeck coefficient and dramatically reduced lattice thermal conductivity, as well as the preserved electronic conductivity in the minibands of the coupling nanowires. The enhancement of ZT to more than 10-fold is achieved in the n-type Si nanowires/Ge host material. Results suggest that the laterally-coupled nanowire arrays can be designed for high-performance thermoelectric devices. -- Highlights: → A high ZT value is predicted in the lateral-coupling nanowire arrays. → The lattice thermal conductivity is dramatically reduced in the lateral direction of nanowire arrays. → The electron transport is preserved in the lateral direction due to the coupling effect. → The ZT value is largely enhanced as the nanowire volume fraction exceeds some critical point.

  12. Early-stage attenuation of phase-amplitude coupling in the hippocampus and medial prefrontal cortex in a transgenic rat model of Alzheimer's disease.

    Science.gov (United States)

    Bazzigaluppi, Paolo; Beckett, Tina L; Koletar, Margaret M; Lai, Aaron Y; Joo, Illsung L; Brown, Mary E; Carlen, Peter L; McLaurin, JoAnne; Stefanovic, Bojana

    2018-03-01

    Alzheimer's disease (AD) is pathologically characterized by amyloid-β peptide (Aβ) accumulation, neurofibrillary tangle formation, and neurodegeneration. Preclinical studies on neuronal impairments associated with progressive amyloidosis have demonstrated some Aβ-dependent neuronal dysfunction including modulation of gamma-aminobutyric acid-ergic signaling. The present work focuses on the early stage of disease progression and uses TgF344-AD rats that recapitulate a broad repertoire of AD-like pathologies to investigate the neuronal network functioning using simultaneous intracranial recordings from the hippocampus (HPC) and the medial prefrontal cortex (mPFC), followed by pathological analyses of gamma-aminobutyric acid (GABA A ) receptor subunits α1 , α5, and δ, and glutamic acid decarboxylases (GAD65 and GAD67). Concomitant to amyloid deposition and tau hyperphosphorylation, low-gamma band power was strongly attenuated in the HPC and mPFC of TgF344-AD rats in comparison to those in non-transgenic littermates. In addition, the phase-amplitude coupling of the neuronal networks in both areas was impaired, evidenced by decreased modulation of theta band phase on gamma band amplitude in TgF344-AD animals. Finally, the gamma coherence between HPC and mPFC was attenuated as well. These results demonstrate significant neuronal network dysfunction at an early stage of AD-like pathology. This network dysfunction precedes the onset of cognitive deficits and is likely driven by Aβ and tau pathologies. This article is part of the Special Issue "Vascular Dementia". © 2017 Her Majesty the Queen in Right of Canada Journal of Neurochemistry © 2017 International Society for Neurochemistry.

  13. Measuring Electromechanical Coupling in Patients with Coronary Artery Disease and Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Lizhen Ji

    2016-04-01

    Full Text Available Coronary artery disease (CAD is the most common cause of death globally. To detect CAD noninvasively at an early stage before clinical symptoms occur is still nowadays challenging. Analysis of the variation of heartbeat interval (RRI opens a new avenue for evaluating the functional change of cardiovascular system which is accepted to occur at the subclinical stage of CAD. In addition, systolic time interval (STI and diastolic time interval (DTI also show potential. There may be coupling in these electromechanical time series due to their physiological connection. However, to the best of our knowledge no publication has systematically investigated how can the coupling be measured and how it changes in CAD patients. In this study, we enrolled 39 CAD patients and 36 healthy subjects and for each subject the electrocardiogram (ECG and photoplethysmography (PPG signals were recorded simultaneously for 5 min. The RRI series, STI series, and DTI series were constructed, respectively. We used linear cross correlation (CC, coherence function (CF, as well as nonlinear mutual information (MI, cross conditional entropy (XCE, cross sample entropy (XSampEn, and cross fuzzy entropy (XFuzzyEn to analyse the bivariate RRI-DTI coupling, RRI-STI coupling, and STI-DTI coupling, respectively. Our results suggest that the linear CC and CF generally have no significant difference between the two groups for all three types of bivariate coupling. The MI only shows weak change in RRI-DTI coupling. By comparison, the three entropy-based coupling measurements show significantly decreased coupling in CAD patients except XSampEn for RRI-DTI coupling (less significant and XCE for STI-DTI and RRI-STI coupling (not significant. Additionally, the XFuzzyEn performs best as it was still significant if we further applied the Bonferroni correction in our statistical analysis. Our study indicates that the intrinsic electromechanical coupling is most probably nonlinear and can better

  14. Techniques for heavy-ion coupled-channels calculations. I. Long-range Coulomb coupling

    International Nuclear Information System (INIS)

    Rhoades-Brown, M.; Macfarlane, M.H.; Pieper, S.C.

    1980-01-01

    Direct-reaction calculations for heavy ions require special computational techniques that take advantage of the physical peculiarities of heavy-ion systems. This paper is the first of a series on quantum-mechanical coupled-channels calculations for heavy ions. It deals with the problems posed by the long range of the Coulomb coupling interaction. Our approach is to use the Alder-Pauli factorization whereby the channel wave functions are expressed as products of Coulomb functions and modulating amplitudes. The equations for the modulating amplitudes are used to integrate inwards from infinity to a nuclear matching radius ( approx. = 20 fm). To adequate accuracy, the equations for the amplitudes can be reduced to first order and solved in first Born approximation. The use of the Born approximation leads to rapid recursion relations for the solutions of the Alder-Pauli equations and hence to a great reduction in computational labor. The resulting coupled-channels Coulomb functions can then be matched in the usual way to solutions of the coupled radial equations in the interior region of r space. Numerical studies demonstrate the reliability of the various techniques introduced

  15. Improving plasmonic waveguides coupling efficiency using nanoantennas

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Bouillard, Jean-Sebastien

    2012-01-01

    . The classical dipole antenna scheme can be improved by changing the nanoantenna geometry, adding constructive elements such as reflecting bars and mirrors and using arrays of antennas. The modelling designates that the coupling efficiency from a vertical fiber to a plasmonic waveguide can be improved more than......Plasmonic waveguides bear a lot of potential for photonic applications. However, one of the challenges for implementing them in devices is the low coupling efficiency to and from optical fibers. We report on our approach to facilitate the coupling efficiency with the use of metallic nanoantennas...... in 180 times in comparison with a direct fiber-waveguide coupling. Pros and cons of each configuration are discussed. Fabrication and characterisation results are reported....

  16. Direct coupling of a genome-scale microbial in silico model and a groundwater reactive transport model.

    Science.gov (United States)

    Fang, Yilin; Scheibe, Timothy D; Mahadevan, Radhakrishnan; Garg, Srinath; Long, Philip E; Lovley, Derek R

    2011-03-25

    The activity of microorganisms often plays an important role in dynamic natural attenuation or engineered bioremediation of subsurface contaminants, such as chlorinated solvents, metals, and radionuclides. To evaluate and/or design bioremediated systems, quantitative reactive transport models are needed. State-of-the-art reactive transport models often ignore the microbial effects or simulate the microbial effects with static growth yield and constant reaction rate parameters over simulated conditions, while in reality microorganisms can dynamically modify their functionality (such as utilization of alternative respiratory pathways) in response to spatial and temporal variations in environmental conditions. Constraint-based genome-scale microbial in silico models, using genomic data and multiple-pathway reaction networks, have been shown to be able to simulate transient metabolism of some well studied microorganisms and identify growth rate, substrate uptake rates, and byproduct rates under different growth conditions. These rates can be identified and used to replace specific microbially-mediated reaction rates in a reactive transport model using local geochemical conditions as constraints. We previously demonstrated the potential utility of integrating a constraint-based microbial metabolism model with a reactive transport simulator as applied to bioremediation of uranium in groundwater. However, that work relied on an indirect coupling approach that was effective for initial demonstration but may not be extensible to more complex problems that are of significant interest (e.g., communities of microbial species and multiple constraining variables). Here, we extend that work by presenting and demonstrating a method of directly integrating a reactive transport model (FORTRAN code) with constraint-based in silico models solved with IBM ILOG CPLEX linear optimizer base system (C library). The models were integrated with BABEL, a language interoperability tool. The

  17. Direct coupling of a genome-scale microbial in silico model and a groundwater reactive transport model

    Science.gov (United States)

    Fang, Yilin; Scheibe, Timothy D.; Mahadevan, Radhakrishnan; Garg, Srinath; Long, Philip E.; Lovley, Derek R.

    2011-03-01

    The activity of microorganisms often plays an important role in dynamic natural attenuation or engineered bioremediation of subsurface contaminants, such as chlorinated solvents, metals, and radionuclides. To evaluate and/or design bioremediated systems, quantitative reactive transport models are needed. State-of-the-art reactive transport models often ignore the microbial effects or simulate the microbial effects with static growth yield and constant reaction rate parameters over simulated conditions, while in reality microorganisms can dynamically modify their functionality (such as utilization of alternative respiratory pathways) in response to spatial and temporal variations in environmental conditions. Constraint-based genome-scale microbial in silico models, using genomic data and multiple-pathway reaction networks, have been shown to be able to simulate transient metabolism of some well studied microorganisms and identify growth rate, substrate uptake rates, and byproduct rates under different growth conditions. These rates can be identified and used to replace specific microbially-mediated reaction rates in a reactive transport model using local geochemical conditions as constraints. We previously demonstrated the potential utility of integrating a constraint-based microbial metabolism model with a reactive transport simulator as applied to bioremediation of uranium in groundwater. However, that work relied on an indirect coupling approach that was effective for initial demonstration but may not be extensible to more complex problems that are of significant interest (e.g., communities of microbial species and multiple constraining variables). Here, we extend that work by presenting and demonstrating a method of directly integrating a reactive transport model (FORTRAN code) with constraint-based in silico models solved with IBM ILOG CPLEX linear optimizer base system (C library). The models were integrated with BABEL, a language interoperability tool. The

  18. Preoperative staging of rectal cancer; Praeoperatives Staging des Rektumkarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A.O.; Baumann, T.; Pache, G.; Langer, M. [Abt. Roentgendiagnostik, Radiologische Universitaetsklinik Freiburg, Freiburg im Breisgau (Germany); Wiech, T. [Inst. fuer Pathologie, Universitaetsklinik Freiburg, Freiburg (Germany)

    2007-07-15

    Accurate preoperative staging of rectal cancer is crucial for therapeutic decision making, as local tumor extent, nodal status, and patterns of metastatic spread are directly associated with different treatment strategies. Recently, treatment approaches have been widely standardized according to large studies and consensus guidelines. Introduced by Heald, total mesorectal excision (TME) is widely accepted as the surgical procedure of choice to remove the rectum together with its enveloping tissues and the mesorectal fascia. Neoadjuvant radiochemotherapy also plays a key role in the treatment of locally advanced stages, while the use of new drugs will lead to a further improvement in oncological outcome. Visualization of the circumferential resection margin is the hallmark of any preoperative imaging and a prerequisite for high-quality TME surgery. The aim of this article is to present an overview on current cross-sectional imaging with emphasis on magnetic resonance imaging. Future perspectives in rectal cancer imaging are addressed. (orig.)

  19. Vehicle systems: coupled and interactive dynamics analysis

    Science.gov (United States)

    Vantsevich, Vladimir V.

    2014-11-01

    This article formulates a new direction in vehicle dynamics, described as coupled and interactive vehicle system dynamics. Formalised procedures and analysis of case studies are presented. An analytical consideration, which explains the physics of coupled system dynamics and its consequences for dynamics of a vehicle, is given for several sets of systems including: (i) driveline and suspension of a 6×6 truck, (ii) a brake mechanism and a limited slip differential of a drive axle and (iii) a 4×4 vehicle steering system and driveline system. The article introduces a formal procedure to turn coupled system dynamics into interactive dynamics of systems. A new research direction in interactive dynamics of an active steering and a hybrid-electric power transmitting unit is presented and analysed to control power distribution between the drive axles of a 4×4 vehicle. A control strategy integrates energy efficiency and lateral dynamics by decoupling dynamics of the two systems thus forming their interactive dynamics.

  20. Collective motions of globally coupled oscillators and some probability distributions on circle

    Energy Technology Data Exchange (ETDEWEB)

    Jaćimović, Vladimir [Faculty of Natural Sciences and Mathematics, University of Montenegro, Cetinjski put, bb., 81000 Podgorica (Montenegro); Crnkić, Aladin, E-mail: aladin.crnkic@hotmail.com [Faculty of Technical Engineering, University of Bihać, Ljubijankićeva, bb., 77000 Bihać, Bosnia and Herzegovina (Bosnia and Herzegovina)

    2017-06-28

    In 2010 Kato and Jones described a new family of probability distributions on circle, obtained as Möbius transformation of von Mises distribution. We present the model demonstrating that these distributions appear naturally in study of populations of coupled oscillators. We use this opportunity to point out certain relations between Directional Statistics and collective motion of coupled oscillators. - Highlights: • We specify probability distributions on circle that arise in Kuramoto model. • We study how the mean-field coupling affects the shape of distribution of phases. • We discuss potential applications in some experiments on cell cycle. • We apply Directional Statistics to study collective dynamics of coupled oscillators.

  1. Couple-level Minority Stress: An Examination of Same-sex Couples' Unique Experiences.

    Science.gov (United States)

    Frost, David M; LeBlanc, Allen J; de Vries, Brian; Alston-Stepnitz, Eli; Stephenson, Rob; Woodyatt, Cory

    2017-12-01

    Social stress resulting from stigma, prejudice, and discrimination-"minority stress"-negatively impacts sexual minority individuals' health and relational well-being. The present study examined how being in a same-sex couple can result in exposure to unique minority stressors not accounted for at the individual level. Relationship timeline interviews were conducted with 120 same-sex couples equally distributed across two study sites (Atlanta and San Francisco), gender (male and female), and relationship duration (at least six months but less than three years, at least three years but less than seven years, and seven or more years). Directed content analyses identified 17 unique couple-level minority stressors experienced within nine distinct social contexts. Analyses also revealed experiences of dyadic minority stress processes (stress discrepancies and stress contagion). These findings can be useful in future efforts to better understand and address the cumulative impact of minority stress on relational well-being and individual health.

  2. Device for the acquisition and visualization in real time of the velocity and direction of wind in a radiological post stage

    International Nuclear Information System (INIS)

    Ledo P, L.M.; Guibert G, R.; Dominguez L, O.; Alonso A, D.; Ramos V, E.O.

    2006-01-01

    The work shows the development, construction and post stage of a device dedicated to the acquisition and transmission in real time of the information on the behavior of the meteorological variables: velocity and wind direction. It is introduced for the first time in an observation position the automatic monitoring, in real time, using the tools that it offers the digitalisation of the information and the computation. The obtained data are registered in a PC, its are visualized appropriately and can be objects of later analysis. It was developed the application program Autoclima for such purpose. (Author)

  3. Three stage Kondo effect in a three quantum dot system

    Science.gov (United States)

    Chiappe, Guillermo; Costa Ribeiro, Laercio; Hamad, Ignacio; Victoriano Anda, Enrique

    2014-03-01

    In this work we study the transport properties of a series connected three quantum dot (QD) system with local strong Coulomb interaction and with one of the extremity QD connected to two metallic leads. We evaluate the local density of states (LDOS) in the QDs and the conductance between the metallic leads considering different magnitudes for the coupling between the central and the extremity QD which is not connected to the leads (side QDs). For small magnitudes of this coupling the LDOS of the QD coupled to the leads present a Kondo resonance with a dip and a very tiny peak at the Fermi level. The widths of these structures are associated to three energy scales, or three Kondo temperatures, which characterizes the three stage Kondo regime. Increasing the coupling between the side QDs we observe a transition to the conventional Kondo regime. We use the multi-configuration Lanczos calculations and the finite U slave-boson mean-field theory. The results present qualitative and quantitative agreement.

  4. A Single-Stage LED Tube Lamp Driver with Power-Factor Corrections and Soft Switching for Energy-Saving Indoor Lighting Applications

    Directory of Open Access Journals (Sweden)

    Chun-An Cheng

    2017-01-01

    Full Text Available This paper presents a single-stage alternating current (AC/direct current (DC light-emitting diode (LED tube lamp driver for energy-saving indoor lighting applications; this driver features power-factor corrections and soft switching, and also integrates a dual buck-boost converter with coupled inductors and a half-bridge series resonant converter cascaded with a bridge rectifier into a single-stage power-conversion topology. The features of the presented driver are high efficiency (>91%, satisfying power factor (PF > 0.96, low input-current total-harmonic distortion (THD < 10%, low output voltage ripple factor (<7.5%, low output current ripple factor (<8%, and zero-voltage switching (ZVS obtained on both power switches. Operational principles are described in detail, and experimental results obtained from an 18 W-rated LED tube lamp for T8/T10 fluorescent lamp replacements with input utility-line voltages ranging from 100 V to 120 V have demonstrated the functionality of the presented driver suitable for indoor lighting applications.

  5. Acoustical coupling of lizard eardrums

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Manley, Geoffrey A

    2008-01-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct...... and indirect sound components on the eardrum. The ensuing pressure-difference characteristics generate the highest directionality of any similar-sized terrestrial vertebrate ear. The aim of the present study was to measure the gain of the direct and indirect sound components in three lizard species: Anolis...... sagrei and Basiliscus vittatus (iguanids) and Hemidactylus frenatus (gekkonid) by laser vibrometry, using either free-field sound or a headphone and coupler for stimulation. The directivity of the ear of these lizards is pronounced in the frequency range from 2 to 5 kHz. The directivity is ovoidal...

  6. Some chaotic features of intrinsically coupled Josephson junctions

    International Nuclear Information System (INIS)

    Kolahchi, M.R.; Shukrinov, Yu.M.; Hamdipour, M.; Botha, A.E.; Suzuki, M.

    2013-01-01

    Highlights: ► Intrinsically coupled Josephson junctions model a high-T c superconductor. ► Intrinsically coupled Josephson junctions can act as a chaotic nonlinear system. ► Chaos could be due to resonance overlap. ► Avoiding parameters that lead to chaos is important for the design of resonators. -- Abstract: We look for chaos in an intrinsically coupled system of Josephson junctions. This study has direct applications for the high-T c resonators which require coherence amongst the junctions

  7. Ion sampling and transport in Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Farnsworth, Paul B.; Spencer, Ross L.

    2017-08-01

    Quantitative accuracy and high sensitivity in inductively coupled plasma mass spectrometry (ICP-MS) depend on consistent and efficient extraction and transport of analyte ions from an inductively coupled plasma to a mass analyzer, where they are sorted and detected. In this review we examine the fundamental physical processes that control ion sampling and transport in ICP-MS and compare the results of theory and computerized models with experimental efforts to characterize the flow of ions through plasma mass spectrometers' vacuum interfaces. We trace the flow of ions from their generation in the plasma, into the sampling cone, through the supersonic expansion in the first vacuum stage, through the skimmer, and into the ion optics that deliver the ions to the mass analyzer. At each stage we consider idealized behavior and departures from ideal behavior that affect the performance of ICP-MS as an analytical tool.

  8. Direct mediation, duality and unification

    International Nuclear Information System (INIS)

    Abel, Steven; Khoze, Valentin V.

    2008-01-01

    It is well-known that in scenarios with direct gauge mediation of supersymmetry breaking the messenger fields significantly affect the running of Standard Model couplings and introduce Landau poles which are difficult to avoid. Among other things, this appears to remove any possibility of a meaningful unification prediction and is often viewed as a strong argument against direct mediation. We propose two ways that Seiberg duality can circumvent this problem. In the first, which we call 'deflected-unification', the SUSY-breaking hidden sector is a magnetic theory which undergoes a Seiberg duality to an electric phase. Importantly, the electric version has fewer fundamental degrees of freedom coupled to the MSSM compared to the magnetic formulation. This changes the β-functions of the MSSM gauge couplings so as to push their Landau poles above the unification scale. We show that this scenario is realised for recently suggested models of gauge mediation based on a metastable SCQD-type hidden sector directly coupled to MSSM. The second possibility for avoiding Landau poles, which we call 'dual-unification', begins with the observation that, if the mediating fields fall into complete SU(5) multiplets, then the MSSM+messengers exhibits a fake unification at unphysical values of the gauge couplings. We show that, in known examples of electric/magnetic duals, such a fake unification in the magnetic theory reflects a real unification in the electric theory. We therefore propose that the Standard Model could itself be a magnetic dual of some unknown electric theory in which the true unification takes place. This scenario maintains the unification prediction (and unification scale) even in the presence of Landau poles in the magnetic theory below the GUT scale. We further note that this dual realization of grand unification can explain why Nature appears to unify, but the proton does not decay.

  9. Exchange effects in direct reactions

    International Nuclear Information System (INIS)

    LeMere, M.; Kanellopoulos, E.J.; Suenkel, W.; Tang, Y.C.

    1979-01-01

    The effect of antisymmetrization in direct reactions is examined by studying the properties of the coupling-normalization kernel function occurring in a resonating-group formulation. From this study, one obtains useful information concerning the general behavior of direct-reactiion processes and some justification for the use of three-body models in phenomenological analyses

  10. Coupling of THALES and FROST using MPI Method

    International Nuclear Information System (INIS)

    Park, Jin Woo; Ryu, Seok Hee; Jung, Chan Do; Jung, Jee Hoon; Um, Kil Sup; Lee, Jae Il

    2013-01-01

    This paper presents the coupling method between THALES and FROST and the simulation results with the coupled code system. In this study, subchannel analysis code THALES and transient fuel performance code FROST were coupled using MPI method as the first stage of the development of the multi-dimensional safety analysis methodology. As a part of the validation, the CEA ejection accident was simulated using the coupled THALES-FROST code and the results were compared with the ShinKori 3 and 4 FSAR. Comparison results revealed that CHASER using MPI method predicts fuel temperatures and heat flux quantitatively well. Thus it was confirmed that the THALES and FROST are properly coupled. In near future, ASTRA, multi-dimensional core neutron kinetics code, will be linked to THALESFROST code for the detailed three-dimensional CEA ejection analysis. The current safety analysis methodology for a CEA ejection accident based on numerous conservative assumptions with the point kinetics model results in quite adverse consequences. Thus, KNF is developing the multi-dimensional safety analysis methodology to enhance the consequences of the CEA ejection accident. For this purpose, three-dimensional core neutron kinetics code ASTRA, subchannel analysis code THALES, and transient fuel performance analysis code FROST are being coupled using message passing interface(MPI). For the first step, THALES and FROST are coupled and tested

  11. Fiber-optic coupled pressure transducer

    International Nuclear Information System (INIS)

    Tallman, C.R.; Wingate, F.P.; Ballard, E.O.

    1979-01-01

    A fiber-optic coupled pressure transducer was developed for measurement of pressure transients produced by fast electrical discharges in laser cavities. A detailed description of the design and performance will be given. Shock tube performance and measurements in direct electrical discharge regions will be presented

  12. Two Kinds of New Lie Algebras for Producing Integrable Couplings

    International Nuclear Information System (INIS)

    Yan Qingyou; Qi Jianxun

    2006-01-01

    Two types of Lie algebras are constructed, which are directly used to deduce the two resulting integrable coupling systems with multi-component potential functions. Many other integrable couplings of the known integrable systems may be obtained by the approach.

  13. Shakespeare Page to Stage: An Active Approach to "Othello."

    Science.gov (United States)

    Thomas, Peter

    1994-01-01

    Presents an account of how one English teacher taught William Shakespeare's "Othello" through dramatics in a challenging way. Considers how teachers of drama might discuss props, stage directions, and the proper handling of Desdemona's handkerchief. Explains how teachers should try to take the plays from "page to stage." (HB)

  14. Degenerate quantum gases with spin-orbit coupling: a review.

    Science.gov (United States)

    Zhai, Hui

    2015-02-01

    This review focuses on recent developments in synthetic spin-orbit (SO) coupling in ultracold atomic gases. Two types of SO coupling are discussed. One is Raman process induced coupling between spin and motion along one of the spatial directions and the other is Rashba SO coupling. We emphasize their common features in both single-particle and two-body physics and the consequences of both in many-body physics. For instance, single particle ground state degeneracy leads to novel features of superfluidity and a richer phase diagram; increased low-energy density-of-state enhances interaction effects; the absence of Galilean invariance and spin-momentum locking gives rise to intriguing behaviours of superfluid critical velocity and novel quantum dynamics; and the mixing of two-body singlet and triplet states yields a novel fermion pairing structure and topological superfluids. With these examples, we show that investigating SO coupling in cold atom systems can, enrich our understanding of basic phenomena such as superfluidity, provide a good platform for simulating condensed matter states such as topological superfluids and more importantly, result in novel quantum systems such as SO coupled unitary Fermi gas and high spin quantum gases. Finally we also point out major challenges and some possible future directions.

  15. Phase coupling in the cardiorespiratory interaction.

    Science.gov (United States)

    Bahraminasab, A; Kenwright, D; Stefanovska, A; Ghasemi, F; McClintock, P V E

    2008-01-01

    Markovian analysis is applied to derive nonlinear stochastic equations for the reconstruction of heart rate and respiration rate variability data. A model of their 'phase' interactions is obtained for the first time, thereby gaining new insights into the strength and direction of the cardiorespiratory phase coupling. The reconstructed model can reproduce synchronisation phenomena between the cardiac and the respiratory systems, including switches in synchronisation ratio. The technique is equally applicable to the extraction of the multi-dimensional couplings between many interacting subsystems.

  16. Reciprocity relation for multichannel coupling kernels

    International Nuclear Information System (INIS)

    Cotanch, S.R.; Satchler, G.R.

    1981-01-01

    Assuming time-reversal invariance of the many-body Hamiltonian, it is proven that the kernels in a general coupled-channels formulation are symmetric, to within a specified spin-dependent phase, under the interchange of channel labels and coordinates. The theorem is valid for both Hermitian and suitably chosen non-Hermitian Hamiltonians which contain complex effective interactions. While of direct practical consequence for nuclear rearrangement reactions, the reciprocity relation is also appropriate for other areas of physics which involve coupled-channels analysis

  17. Establishment and analysis of coupled dynamic model for dual-mass silicon micro-gyroscope

    Science.gov (United States)

    Wang, Zhanghui; Qiu, Anping; Shi, Qin; Zhang, Taoyuan

    2017-12-01

    This paper presents a coupled dynamic model for a dual-mass silicon micro-gyroscope (DMSG). It can quantitatively analyze the influence of left-right stiffness difference on the natural frequencies, modal matrix and modal coupling coefficient of the DMSG. The analytic results are verified by using the finite element method (FEM) simulation. The model shows that with the left-right stiffness difference of 1%, the modal coupling coefficient is 12% in the driving direction and 31% in the sensing direction. It also shows that in order to achieve good separation, the stiffness of base beam should be small enough in both the driving and sensing direction.

  18. The single- and double-particle properties and the current reversal of coupled Brownian motors

    International Nuclear Information System (INIS)

    Li, Chen-Pu; Chen, Hong-Bin; Zheng, Zhi-Gang; Fan, Hong; Shen, Wen-Mei

    2017-01-01

    In this paper, we investigate the directed transport of coupled Brownian motors composed of two identical particles which is individually subject to a time-symmetric rocking force in spatially-symmetric periodic potentials. We find that both the coupling free length and the coupling strength can induce the reversed motion of the coupled Brownian motors, the essence of which is the coupled Brownian motors can exhibit completely different single- or double-particle properties under certain conditions. Namely, the current reversal is the result of the mutual conversion between the single- and double-particle properties of the coupled Brownian motors. Moreover, the directed current of coupled Brownian motors can be optimized and manipulated by adjusting the strength, the period, the phase difference of the rocking forces, and the noise intensity. (paper)

  19. Direct detection with dark mediators

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, David; Surujon, Ze' ev [C. N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794 (United States); Tsai, Yuhsin [Physics Department, University of California Davis, Davis, CA 95616 (United States)

    2014-11-10

    We introduce dark mediator Dark Matter (dmDM) where the dark and visible sectors are connected by at least one light mediator ϕ carrying the same dark charge that stabilizes DM. ϕ is coupled to the Standard Model via an operator q{sup ¯}qϕϕ{sup ⁎}/Λ, and to dark matter via a Yukawa coupling y{sub χ}χ{sup c¯}χϕ. Direct detection is realized as the 2→3 process χN→χ{sup ¯}Nϕ at tree-level for m{sub ϕ}≲10 keV and small Yukawa coupling, or alternatively as a loop-induced 2→2 process χN→χN. We explore the direct-detection consequences of this scenario and find that a heavy O(100 GeV) dmDM candidate fakes different O(10 GeV) standard WIMPs in different experiments. Large portions of the dmDM parameter space are detectable above the irreducible neutrino background and not yet excluded by any bounds. Interestingly, for the m{sub ϕ} range leading to novel direct detection phenomenology, dmDM is also a form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies between dwarf galaxy observations and numerical simulations.

  20. An Integrated Hot-Stage Microscope-Direct Analysis in Real Time-Mass Spectrometry System for Studying the Thermal Behavior of Materials.

    Science.gov (United States)

    Ashton, Gage P; Harding, Lindsay P; Parkes, Gareth M B

    2017-12-19

    This paper describes a new analytical instrument that combines a precisely temperature-controlled hot-stage with digital microscopy and Direct Analysis in Real Time-mass spectrometry (DART-MS) detection. The novelty of the instrument lies in its ability to monitor processes as a function of temperature through the simultaneous recording of images, quantitative color changes, and mass spectra. The capability of the instrument was demonstrated through successful application to four very varied systems including profiling an organic reaction, decomposition of silicone polymers, and the desorption of rhodamine B from an alumina surface. The multidimensional, real-time analytical data provided by this instrument allow for a much greater insight into thermal processes than could be achieved previously.

  1. A gateway to new physics: direct measurement of the top Yukawa coupling to the Higgs boson

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00405244; Wermes, Norbert

    The top quark has the largest Yukawa coupling in the Standard Model, is the main contribution to the Higgs mass $m_H$ corrections and defines the evolution of the Higgs effective potential with the energy, together with $m_H$. It can be directly measured through the associated production process $pp \\to t\\bar{t}H$. Two searches for this process are described in this thesis, using data collected with the ATLAS detector at the Large Hadron Collider. The fully hadronic analysis is performed with data corresponding to an integrated luminosity of $20.3\\,\\text{fb}^{-1}$ at a centre-of-mass energy of $\\sqrt{s}=8\\,\\text{TeV}$ and uses a boosted decision tree algorithm to discriminate between signal and background: the dominant multijet background is estimated using a data-driven method. An upper limit of $6.4$ ($5.4$) times the Standard Model cross section is observed (expected) at 95% confidence level and a best-fit value of $1.6 \\pm 2.6$ for the signal strength $\\mu_{t\\bar{t}H}=\\sigma_{t\\bar{t}H}^\\text{obs}/\\sigma...

  2. Direct convertor based upon space charge effects

    International Nuclear Information System (INIS)

    Gitomer, S.J.

    1977-01-01

    A device capable of converting directly the kinetic energy of charged particles into electrical energy is considered. The device differs from earlier ones (such as Post's periodic focus electrostatic direct convertor) in that it makes use of the space charge repulsion in a high density charged particle beam. The beam is directed into a monotonic decelerating electrostatic field of a several-stage planar-finned structure. The collector fins coincide with vacuum equipotential surfaces. Space charge blowup of the beam directs particles onto various collector fins. The energy efficiency of a 4-stage device has been determined using a numberical simulation approach. We find that efficiencies approaching 75 percent are possible. An approximate scaling law is derived for the space charge based direct converter and a comparison is made to the periodic focus direct convertor. We find the space charge based direct convertor to be superior to a number of ways

  3. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  4. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Yang, Lihui; Zhang, Yongming; Bai, Qi; Yan, Ning; Xu, Hua; Rittmann, Bruce E.

    2015-01-01

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  5. Effects of a Randomized Couple-Based Intervention on Quality of Life of Breast Cancer Patients and Their Partners

    Science.gov (United States)

    Kayser, Karen; Feldman, Barry N.; Borstelmann, Nancy A.; Daniels, Ann A.

    2010-01-01

    The purpose of this study was to determine the effectiveness of a couple-based intervention on the quality of life (QOL) of early-stage breast cancer patients and their partners. A randomized controlled design was used to assign couples to either the hospital standard social work services (SSWS) or a couple-based intervention, the Partners in…

  6. A 3-stage model for assessing the probable economic effects of direct-to-consumer advertising of pharmaceuticals.

    Science.gov (United States)

    Vogel, Ronald J; Ramachandran, Sulabha; Zachry, Woodie M

    2003-01-01

    The pharmaceutical industry employs a variety of marketing strategies that have previously been directed primarily toward physicians. However, mass media direct-to-consumer (DTC) advertising of prescription drugs has emerged as a ubiquitous promotional strategy. This article explores the economics of DTC advertising in greater depth than has been done in the past by using a 3-stage economic model to assess the pertinent literature and to show the probable effects of DTC advertising in the United States. Economics literature on the subject was searched using the Journal of Economic Literature. Health services literature was searched using computer callback devices. Spending on DTC advertising in the United States increased from $17 million in 1985 to $2.5 billion in 2000. Proponents of DTC advertising claim that it provides valuable product-related information to health care professionals and patients, may contribute to better use of medications, and helps patients take charge of their own health care. Opponents argue that DTC advertising provides misleading messages rather than well-balanced, evidence-based information. The literature is replete with opinions about the effects of prescription drug advertising on pharmaceutical drug prices and physician-prescribing patterns, but few studies have addressed the issues beyond opinion surveys. The economic literature on advertising effects in other markets, however, may provide insight. DTC advertising indirectly affects the price and the quantity of production of pharmaceuticals via its effect on changes in consumer demand.

  7. Biologically inspired coupled antenna beampattern design

    Energy Technology Data Exchange (ETDEWEB)

    Akcakaya, Murat; Nehorai, Arye, E-mail: makcak2@ese.wustl.ed, E-mail: nehorai@ese.wustl.ed [Department of Electrical and Systems Engineering, Washington University in St Louis, St Louis, MO 63130 (United States)

    2010-12-15

    We propose to design a small-size transmission-coupled antenna array, and corresponding radiation pattern, having high performance inspired by the female Ormia ochracea's coupled ears. For reproduction purposes, the female Ormia is able to locate male crickets' call accurately despite the small distance between its ears compared with the incoming wavelength. This phenomenon has been explained by the mechanical coupling between the Ormia's ears, which has been modeled by a pair of differential equations. In this paper, we first solve these differential equations governing the Ormia ochracea's ear response, and convert the response to the pre-specified radio frequencies. We then apply the converted response of the biological coupling in the array factor of a uniform linear array composed of finite-length dipole antennas, and also include the undesired electromagnetic coupling due to the proximity of the elements. Moreover, we propose an algorithm to optimally choose the biologically inspired coupling for maximum array performance. In our numerical examples, we compute the radiation intensity of the designed system for binomial and uniform ordinary end-fire arrays, and demonstrate the improvement in the half-power beamwidth, sidelobe suppression and directivity of the radiation pattern due to the biologically inspired coupling.

  8. Coupled uncertainty provided by a multifractal random walker

    International Nuclear Information System (INIS)

    Koohi Lai, Z.; Vasheghani Farahani, S.; Movahed, S.M.S.; Jafari, G.R.

    2015-01-01

    The aim here is to study the concept of pairing multifractality between time series possessing non-Gaussian distributions. The increasing number of rare events creates “criticality”. We show how the pairing between two series is affected by rare events, which we call “coupled criticality”. A method is proposed for studying the coupled criticality born out of the interaction between two series, using the bivariate multifractal random walk (BiMRW). This method allows studying dependence of the coupled criticality on the criticality of each individual system. This approach is applied to data sets of gold and oil markets, and inflation and unemployment. - Highlights: • The coupled criticality between two systems is modeled by the bivariate multifractal random walk. • This coupled criticality is generally directed. • This coupled criticality is inversely proportional to the criticality of either of the systems. • The coupled criticality can emerge when at least one of the systems posses a Gaussian distribution

  9. Superstring threshold corrections to Yukawa couplings

    International Nuclear Information System (INIS)

    Antoniadis, I.; Taylor, T.R.

    1992-12-01

    A general method of computing string corrections to the Kaehler metric and Yukawa couplings is developed at the one-loop level for a general compactification of the heterotic superstring theory. It also provides a direct determination of the so-called Green-Schwarz term. The matter metric has an infrared divergent part which reproduces the field-theoretical anomalous dimensions, and a moduli-dependent part which gives rise to threshold corrections in the physical Yukawa couplings. Explicit expressions are derived for symmetric orbifold compactifications. (author). 20 refs

  10. Staged fuel and air injection in combustion systems of gas turbines

    Science.gov (United States)

    Hughes, Michael John; Berry, Jonathan Dwight

    2018-04-17

    A gas turbine that includes a working fluid flowpath extending aftward from a forward injector in a combustor. The combustor may include an inner radial wall, an outer radial wall, and, therebetween, a flow annulus. A staged injector may intersect the flow annulus so to attain an injection point within the working fluid flowpath by which aftward and forward annulus sections are defined. Air directing structure may include an aftward intake section that corresponds to the aftward annulus section and a forward intake section that corresponds to the forward annulus section. The air directing structure may be configured to: direct air entering through the aftward intake section through the aftward annulus section in a forward direction to the staged injector; and direct air entering through the forward intake section through the forward annulus section in a forward direction to the forward injector.

  11. Cross-Coupled Eye Movement Supports Neural Origin of Pattern Strabismus

    Science.gov (United States)

    Ghasia, Fatema F.; Shaikh, Aasef G.; Jacobs, Jonathan; Walker, Mark F.

    2015-01-01

    Purpose. Pattern strabismus describes vertically incomitant horizontal strabismus. Conventional theories emphasized the role of orbital etiologies, such as abnormal fundus torsion and misaligned orbital pulleys as a cause of the pattern strabismus. Experiments in animal models, however, suggested the role of abnormal cross-connections between the neural circuits. We quantitatively assessed eye movements in patients with pattern strabismus with a goal to delineate the role of neural circuits versus orbital etiologies. Methods. We measured saccadic eye movements with high-precision video-oculography in 14 subjects with pattern strabismus, 5 with comitant strabismus, and 15 healthy controls. We assessed change in eye position in the direction orthogonal to that of the desired eye movement (cross-coupled responses). We used fundus photography to quantify the fundus torsion. Results. We found cross-coupling of saccades in all patients with pattern strabismus. The cross-coupled responses were in the same direction in both eyes, but larger in the nonviewing eye. All patients had clinically apparent inferior oblique overaction with abnormal excylotorsion. There was no correlation between the amount of the fundus torsion or the grade of oblique overaction and the severity of cross-coupling. The disconjugacy in the saccade direction and amplitude in pattern strabismics did not have characteristics predicted by clinically apparent inferior oblique overaction. Conclusions. Our results validated primate models of pattern strabismus in human patients. We found no correlation between ocular torsion or oblique overaction and cross-coupling. Therefore, we could not ascribe cross-coupling exclusively to the orbital etiology. Patients with pattern strabismus could have abnormalities in the saccade generators. PMID:26024072

  12. CHEMVAL project: report on stages 3 and 4

    International Nuclear Information System (INIS)

    Read, D.

    1991-01-01

    This report describes the results of CHEMVAL Stages 3 and 4, an international coupled chemical transport model verification/validation exercise involving the participation of research organisations within EC countries, Sweden, Switzerland and Finland. The methodology employed and results obtained for fifteen verification tests of varying complexity are described. The outcome of validation studies against two well characterised experimental systems is also assessed in terms of the requirements for radiological risk assessment. (author)

  13. A 1.2-V CMOS front-end for LTE direct conversion SAW-less receiver

    International Nuclear Information System (INIS)

    Wang Riyan; Li Zhengping; Zhang Weifeng; Zeng Longyue; Huang Jiwei

    2012-01-01

    A CMOS RF front-end for the long-term evolution (LTE) direct conversion receiver is presented. With a low noise transconductance amplifier (LNA), current commutating passive mixer and transimpedance operational amplifier (TIA), the RF front-end structure enables high-integration, high linearity and simple frequency planning for LTE multi-band applications. Large variable gain is achieved using current-steering transconductance stages. A current commutating passive mixer with 25% duty-cycle LO improves gain, noise and linearity. A direct coupled current-input filter (DCF) is employed to suppress the out-of-band interferer. Fabricated in a 0.13-μm CMOS process, the RF front-end achieves a 45 dB conversion voltage gain, 2.7 dB NF, −7 dBm IIP3, and +60 dBm IIP2 with calibration from 2.3 to 2.7 GHz. The total RF front end with divider draws 40 mA from a single 1.2-V supply. (semiconductor integrated circuits)

  14. On couplings to matter in massive (bi-)gravity

    International Nuclear Information System (INIS)

    Rham, Claudia de; Ribeiro, Raquel H; Heisenberg, Lavinia

    2015-01-01

    We investigate the coupling to matter in ghost-free massive (bi-)gravity. When species in the matter sector couple covariantly to only one metric, we show that at one-loop these couplings do not spoil the special structure of the graviton potential. When the same species couples directly to both metrics we show that a ghost is present at the classical level and that loops destroy the special structure of the potential at an unacceptably low scale. We then propose a new ‘composite’ effective metric built out of both metrics. When matter fields couple covariantly to this effective metric, the would be Boulware–Deser (BD) ghost is absent in different representative limits. At one-loop such couplings do not detune the special structure of the potential. We conjecture that matter can couple covariantly to that effective metric in all generality without introducing any BD ghost below a cut-off scale parametrically larger than the strong coupling scale. We also discuss alternative couplings to matter where the kinetic and potential terms of the matter field couple to different metrics. In both cases we discuss preliminary implications for cosmology. (paper)

  15. A novel bridge coupler for SSC coupled cavity linac

    International Nuclear Information System (INIS)

    Yao, C.G.; Chang, C.R.; Funk, W.

    1992-01-01

    A novel magnetically coupled multi-cavity bridge coupler is proposed for SSC Coupled-Cavity-Linac (CCL). The bridge coupler is a five cell disc-loaded waveguide with a small central aperture used for measurement and two large curved coupling slots near the edge on each disc. The two coupling slots on the adjacent disc are rotated 90 degrees in orientation to reduce the direct coupling. This type of structure is capable of producing very large coupling (>10% in our longest bridge coupler). Also because of the small opening on the discs, the high-order-modes are very far (> 300 MHz) above the operating mode. Thus for long bridge couplers, the magnetic coupled structure should provide maximum coupling with minimum mode mixing problems. In this paper both physics and engineering issues of this new bridge coupler are presented. (Author) 5 refs., 2 tabs., 6 figs

  16. Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.

    Directory of Open Access Journals (Sweden)

    Prabhat S Kunwar

    2003-12-01

    Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

  17. Attachment and couple satisfaction as predictors of expressed emotion in women facing breast cancer and their partners in the immediate post-surgery period.

    Science.gov (United States)

    Favez, Nicolas; Cairo Notari, Sarah; Antonini, Tania; Charvoz, Linda

    2017-02-01

    To investigate expressed emotion (EE) in couples facing breast cancer in the immediate post-surgery period. EE may be predictive of psychological disturbances that hinder both partners' capacities to cope with the stress of the disease. Severity of the disease, attachment tendencies, and couple satisfaction were tested as predictors of EE. The design was cross-sectional. Couples (N = 61) were interviewed 2 weeks after the women's breast surgery. Expressed emotion was assessed in women and in partners with the Five-Minute Speech Sample, with a focus on overt and covert criticisms. Self-reported EE, attachment tendencies, and couple satisfaction were assessed with questionnaires. Hierarchical regression analyses were performed to test the predictors and possible interactions between them. Both partners expressed overt and covert criticisms; women expressed more overt criticisms than did their partners. Cancer stage was inversely related to the number of overt criticisms in women and to the number of covert criticisms in partners. Regression analyses showed that in women, higher attachment anxiety and lower couple satisfaction were positive predictors of overt criticisms; in partners, a higher cancer stage was a negative predictor of overt and covert criticisms. Practitioners should pay attention to the couple relationship in breast cancer. EE is most likely to appear when the cancer stage is low, showing that even when the medical prognosis is optimal, relational and emotional disturbances may occur. Statement of contribution What is already known on this subject? The couple relationship is of paramount importance in breast cancer. Expressed emotion (EE) is related to negative individual and relational psychological outcomes in psychiatric and somatic diseases. Expressed emotion has not yet been studied in the context of breast cancer. What does this study add? Expressed emotion is present in breast cancer situations, especially when the cancer stage is low. There

  18. Development of a Microfluidic Open Interface with Flow Isolated Desorption Volume for the Direct Coupling of SPME Devices to Mass Spectrometry.

    Science.gov (United States)

    Tascon, Marcos; Alam, Md Nazmul; Gómez-Ríos, Germán Augusto; Pawliszyn, Janusz

    2018-02-20

    Technologies that efficiently integrate the sampling and sample preparation steps with direct introduction to mass spectrometry (MS), providing simple and sensitive analytical workflows as well as capabilities for automation, can generate a great impact in a vast variety of fields, such as in clinical, environmental, and food-science applications. In this study, a novel approach that facilitates direct coupling of Bio-SPME devices to MS using a microfluidic design is presented. This technology, named microfluidic open interface (MOI), which operates under the concept of flow-isolated desorption volume, consists of an open-to-ambient desorption chamber (V ≤ 7 μL) connected to an ionization source. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such as electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Using this setup, the desorption chamber is used to release target compounds from the coating, while the isolation of the flow enables the ionization source to be continuously fed with solvent, all without the necessity of employment of additional valves. As a proof of concept, the design was applied to an ESI-MS/MS system for experimental validation. Furthermore, numerical simulations were undertaken to provide a detailed understanding of the fluid flow pattern inside the interface, then used to optimize the system for better efficiency. The analytical workflow of the developed Bio-SPME-MOI-MS setup consists of the direct immersion of SPME fibers into the matrix to extract/enrich analytes of interest within a short period of time, followed by a rinsing step with water to remove potentially adhering proteins, salts, and/or other interfering compounds. Next, the fiber is inserted into the

  19. Synchronization of complex delayed dynamical networks with nonlinearly coupled nodes

    International Nuclear Information System (INIS)

    Liu Tao; Zhao Jun; Hill, David J.

    2009-01-01

    In this paper, we study the global synchronization of nonlinearly coupled complex delayed dynamical networks with both directed and undirected graphs. Via Lyapunov-Krasovskii stability theory and the network topology, we investigate the global synchronization of such networks. Under the assumption that coupling coefficients are known, a family of delay-independent decentralized nonlinear feedback controllers are designed to globally synchronize the networks. When coupling coefficients are unavailable, an adaptive mechanism is introduced to synthesize a family of delay-independent decentralized adaptive controllers which guarantee the global synchronization of the uncertain networks. Two numerical examples of directed and undirected delayed dynamical network are given, respectively, using the Lorenz system as the nodes of the networks, which demonstrate the effectiveness of proposed results.

  20. A theoretical study of a direct contact membrane distillation system coupled to a salt-gradient solar pond for terminal lakes reclamation.

    Science.gov (United States)

    Suárez, Francisco; Tyler, Scott W; Childress, Amy E

    2010-08-01

    Terminal lakes are water bodies that are located in closed watersheds with the only output of water occurring through evaporation or infiltration. The majority of these lakes, which are commonly located in the desert and influenced by human activities, are increasing in salinity. Treatment options are limited, due to energy costs, and many of these lakes provide an excellent opportunity to test solar-powered desalination systems. This paper theoretically investigates utilization of direct contact membrane distillation (DCMD) coupled to a salt-gradient solar pond (SGSP) for sustainable freshwater production at terminal lakes. A model for heat and mass transport in the DCMD module and a thermal model for an SGSP were developed and coupled to evaluate the feasibility of freshwater production. The construction of an SGSP outside and inside of a terminal lake was studied. As results showed that freshwater flows are on the same order of magnitude as evaporation, these systems will only be successful if the SGSP is constructed inside the terminal lake so that there is little or no net increase in surface area. For the study site of this investigation, water production on the order of 2.7 x 10(-3) m(3) d(-1) per m(2) of SGSP is possible. The major advantages of this system are that renewable thermal energy is used so that little electrical energy is required, the coupled system requires low maintenance, and the terminal lake provides a source of salts to create the stratification in the SGSP. (c) 2010 Elsevier Ltd. All rights reserved.

  1. Temperature influences selective mortality during the early life stages of a coral reef fish.

    Directory of Open Access Journals (Sweden)

    Tauna L Rankin

    2011-05-01

    Full Text Available For organisms with complex life cycles, processes occurring at the interface between life stages can disproportionately impact survival and population dynamics. Temperature is an important factor influencing growth in poikilotherms, and growth-related processes are frequently correlated with survival. We examined the influence of water temperature on growth-related early life history traits (ELHTs and differential mortality during the transition from larval to early juvenile stage in sixteen monthly cohorts of bicolor damselfish Stegastes partitus, sampled on reefs of the upper Florida Keys, USA over 6 years. Otolith analysis of settlers and juveniles coupled with environmental data revealed that mean near-reef water temperature explained a significant proportion of variation in pelagic larval duration (PLD, early larval growth, size-at-settlement, and growth during early juvenile life. Among all cohorts, surviving juveniles were consistently larger at settlement, but grew more slowly during the first 6 d post-settlement. For the other ELHTs, selective mortality varied seasonally: during winter and spring months, survivors exhibited faster larval growth and shorter PLDs, whereas during warmer summer months, selection on PLD reversed and selection on larval growth became non-linear. Our results demonstrate that temperature not only shapes growth-related traits, but can also influence the direction and intensity of selective mortality.

  2. High cost of stage IV pressure ulcers.

    Science.gov (United States)

    Brem, Harold; Maggi, Jason; Nierman, David; Rolnitzky, Linda; Bell, David; Rennert, Robert; Golinko, Michael; Yan, Alan; Lyder, Courtney; Vladeck, Bruce

    2010-10-01

    The aim of this study was to calculate and analyze the cost of treatment for stage IV pressure ulcers. A retrospective chart analysis of patients with stage IV pressure ulcers was conducted. Hospital records and treatment outcomes of these patients were followed up for a maximum of 29 months and analyzed. Costs directly related to the treatment of pressure ulcers and their associated complications were calculated. Nineteen patients with stage IV pressure ulcers (11 hospital-acquired and 8 community-acquired) were identified and their charts were reviewed. The average hospital treatment cost associated with stage IV pressure ulcers and related complications was $129,248 for hospital-acquired ulcers during 1 admission, and $124,327 for community-acquired ulcers over an average of 4 admissions. The costs incurred from stage IV pressure ulcers are much greater than previously estimated. Halting the progression of early stage pressure ulcers has the potential to eradicate enormous pain and suffering, save thousands of lives, and reduce health care expenditures by millions of dollars. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Direct coupling of a liquid chromatograph to a continuous flow hydrogen nuclear magnetic resonance detector for analysis of petroleum and synthetic fuels

    International Nuclear Information System (INIS)

    Haw, J.F.; Glass, T.E.; Hausler, D.W.; Motell, E.; Dorn, H.C.

    1980-01-01

    Initial results obtained for a flow 1 H nuclear magnetic resonance (NMR) detector directly coupled to a liquid chromatography unit are described. Results achieved for a model mixture and several jet fuel samples are discussed. Chromatographic separation of alkanes, alkylbenzenes, and substituted naphthalenes present in the jet fuel samples are easily identified with the 1 H NMR detector. Results with our present flow 1 H NMR insert indicate that 5-Hz linewidths are readily obtainable for typical chromatographic flow rates. The limitations and advantages of this liquid chromatography detector are compared with more commonly employed detectors (e.g., refractive index detectors). 11 figures

  4. Measurement reduction for mutual coupling calibration in DOA estimation

    Science.gov (United States)

    Aksoy, Taylan; Tuncer, T. Engin

    2012-01-01

    Mutual coupling is an important source of error in antenna arrays that should be compensated for super resolution direction-of-arrival (DOA) algorithms, such as Multiple Signal Classification (MUSIC) algorithm. A crucial step in array calibration is the determination of the mutual coupling coefficients for the antenna array. In this paper, a system theoretic approach is presented for the mutual coupling characterization of antenna arrays. The comprehension and implementation of this approach is simple leading to further advantages in calibration measurement reduction. In this context, a measurement reduction method for antenna arrays with omni-directional and identical elements is proposed which is based on the symmetry planes in the array geometry. The proposed method significantly decreases the number of measurements during the calibration process. This method is evaluated using different array types whose responses and the mutual coupling characteristics are obtained through numerical electromagnetic simulations. It is shown that a single calibration measurement is sufficient for uniform circular arrays. Certain important and interesting characteristics observed during the experiments are outlined.

  5. A coupled photometric assay for characterization of S-adenosyl-l-homocysteine hydrolases in the physiological hydrolytic direction.

    Science.gov (United States)

    Kailing, Lyn L; Bertinetti, Daniela; Herberg, Friedrich W; Pavlidis, Ioannis V

    2017-10-25

    S-Adenosyl-l-homocysteine hydrolases (SAHases) are important metabolic enzymes and their dysregulation is associated with some severe diseases. In vivo they catalyze the hydrolysis of S-adenosyl-l-homocysteine (SAH), the by-product of methylation reactions in various organisms. SAH is a potent inhibitor of methyltransferases, thus its removal from the equilibrium is an important requirement for methylation reactions. SAH hydrolysis is also the first step in the cellular regeneration process of the methyl donor S-adenosyl-l-methionine (SAM). However, in vitro the equilibrium lies towards the synthetic direction. To enable characterization of SAHases in the physiologically relevant direction, we have developed a coupled photometric assay that shifts the equilibrium towards hydrolysis by removing the product adenosine, using a high affinity adenosine kinase (AK). This converts adenosine to AMP and thereby forms equimolar amounts of ADP, which is phosphorylated by a pyruvate kinase (PK), in turn releasing pyruvate. The readout of the assay is the consumption of NADH during the lactate dehydrogenase (LDH) catalyzed reduction of pyruvate to lactic acid. The applicability of the assay is showcased for the determination of the kinetic constants of an SAHase from Bradyrhizobium elkanii (K M,SAH 41±5μM, v max,SAH 25±1μM/min with 0.13mg/mL enzyme). This assay is a valuable tool for in vitro characterization of SAHases with biotechnological potential, and for monitoring SAHase activity in diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Coding "We-ness" in couple's relationship stories: A method for assessing mutuality in couple therapy.

    Science.gov (United States)

    Gildersleeve, Sara; Singer, Jefferson A; Skerrett, Karen; Wein, Shelter

    2017-05-01

    "We-ness," a couple's mutual investment in their relationship and in each other, has been found to be a potent dimension of couple resilience. This study examined the development of a method to capture We-ness in psychotherapy through the coding of relationship narratives co-constructed by couples ("We-Stories"). It used a coding system to identify the core thematic elements that make up these narratives. Couples that self-identified as "happy" (N = 53) generated We-Stories and completed measures of relationship satisfaction and mutuality. These stories were then coded using the We-Stories coding manual. Findings indicated that security, an element that involves aspects of safety, support, and commitment, was most common, appearing in 58.5% of all narratives. This element was followed by the elements of pleasure (49.1%) and shared meaning/vision (37.7%). The number of "We-ness" elements was also correlated with and predictive of discrepancy scores on measures of relationship mutuality, indicating the validity of the We-Stories coding manual. Limitations and future directions are discussed.

  7. Spin–orbit coupling in actinide cations

    DEFF Research Database (Denmark)

    Bagus, Paul S.; Ilton, Eugene S.; Martin, Richard L.

    2012-01-01

    The limiting case of Russell–Saunders coupling, which leads to a maximum spin alignment for the open shell electrons, usually explains the properties of high spin ionic crystals with transition metals. For actinide compounds, the spin–orbit splitting is large enough to cause a significantly reduced...... spin alignment. Novel concepts are used to explain the dependence of the spin alignment on the 5f shell occupation. We present evidence that the XPS of ionic actinide materials may provide direct information about the angular momentum coupling within the 5f shell....

  8. Mechanisms of stage-transcending protection following immunization of mice with late liver stage-arresting genetically attenuated malaria parasites.

    Directory of Open Access Journals (Sweden)

    Brandon K Sack

    2015-05-01

    Full Text Available Malaria, caused by Plasmodium parasite infection, continues to be one of the leading causes of worldwide morbidity and mortality. Development of an effective vaccine has been encumbered by the complex life cycle of the parasite that has distinct pre-erythrocytic and erythrocytic stages of infection in the mammalian host. Historically, malaria vaccine development efforts have targeted each stage in isolation. An ideal vaccine, however, would target multiple life cycle stages with multiple arms of the immune system and be capable of eliminating initial infection in the liver, the subsequent blood stage infection, and would prevent further parasite transmission. We have previously shown that immunization of mice with Plasmodium yoelii genetically attenuated parasites (GAP that arrest late in liver stage development elicits stage-transcending protection against both a sporozoite challenge and a direct blood stage challenge. Here, we show that this immunization strategy engenders both T- and B-cell responses that are essential for stage-transcending protection, but the relative importance of each is determined by the host genetic background. Furthermore, potent anti-blood stage antibodies elicited after GAP immunization rely heavily on FC-mediated functions including complement fixation and FC receptor binding. These protective antibodies recognize the merozoite surface but do not appear to recognize the immunodominant merozoite surface protein-1. The antigen(s targeted by stage-transcending immunity are present in both the late liver stages and blood stage parasites. The data clearly show that GAP-engendered protective immune responses can target shared antigens of pre-erythrocytic and erythrocytic parasite life cycle stages. As such, this model constitutes a powerful tool to identify novel, protective and stage-transcending T and B cell targets for incorporation into a multi-stage subunit vaccine.

  9. Use of microextraction by packed sorbent directly coupled to an electron ionization single quadrupole mass spectrometer as an alternative for non-separative determinations.

    Science.gov (United States)

    Casas Ferreira, Ana María; Moreno Cordero, Bernardo; Pérez Pavón, José Luis

    2017-02-01

    Sometimes it is not necessary to separate the individual compounds of a sample to resolve an analytical problem, it is enough to obtain a signal profile of the sample formed by all the components integrating it. Within this strategy, electronic noses based on the direct coupling of a headspace sampler with a mass spectrometer (HS-MS) have been proposed. Nevertheless, this coupling is not suitable for the analysis of non-volatile compounds. In order to propose an alternative to HS-MS determinations for non-volatile compounds, here we present the first 'proof of concept' use of the direct coupling of microextraction by packed sorbents (MEPS) to a mass spectrometer device using an electron ionization (EI) and a single quadrupole as ionization source and analyzer, respectively. As target compounds, a set of analytes with different physic-chemical properties were evaluated (2-ethyl-1-hexanol, styrene, 2-heptanone, among others). The use of MEPS extraction present many advantages, such as it is fast, simple, easy to automate and requires small volumes of sample and organic solvents. Moreover, MEPS cartridges are re-usable as samples can be extracted more than 100 times using the same syringe. In order to introduce into the system all the elution volume from the MEPS extraction, a programmable temperature vaporizer (PTV) is proposed as the injector device. Results obtained with the proposed methodology (MEPS-PTV/MS) were compared with the ones obtained based on the separative scheme, i.e. using gas chromatography separation (MEPS-PTV-GC/MS), and both methods provided similar results. Limits of detection were found to be between 3.26 and 146.6μgL -1 in the non-separative scheme and between 0.02 and 1.72μgL -1 when the separative methodology was used. Repeatability and reproducibility were evaluated with values below 17% in all cases. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Sensitivity enhanced NMR spectroscopy by quenching scalar coupling mediated relaxation: Application to the direct observation of hydrogen bonds in 13C/15N-labeled proteins

    Energy Technology Data Exchange (ETDEWEB)

    Liu Aizhuo; Hu Weidong; Qamar, Seema; Majumdar, Ananya [Memorial Sloan-Kettering Cancer Center, Cellular Biochemistry and Biophysics Program (United States)

    2000-05-15

    In this paper, we demonstrate that the sensitivity of triple-resonance NMR experiments can be enhanced significantly through quenching scalar coupling mediated relaxation by using composite-pulse decoupling (CPD) or an adiabatic decoupling sequence on aliphatic, in particular alpha-carbons in {sup 13}C/{sup 15}N-labeled proteins. The CPD-HNCO experiment renders 50% sensitivity enhancement over the conventional CT-HNCO experiment performed on a 12 kDa FK506 binding protein, when a total of 266 ms of amide nitrogen-carbonyl carbon defocusing and refocusing periods is employed. This is a typical time period for the direct detection of hydrogen bonds in proteins via trans-hydrogen bond {sup 3h}J{sub NC'} couplings. The experimental data fit theoretical analysis well. The significant enhancement in sensitivity makes the experiment more applicable to larger-sized proteins without resorting to perdeuteration.

  11. Development of a simple extraction cell with bi-directional continuous flow coupled on-line to ICP-MS for assessment of elemental associations in solid samples

    DEFF Research Database (Denmark)

    Buanuam, Janya; Tiptanasup, Kasipa; Shiowatana, Juwadee

    2006-01-01

    A continuous-flow system comprising a novel, custom-built extraction module and hyphenated with inductively coupled plasma-mass spectrometric (ICP-MS) detection is proposed for assessing metal mobilities and geochemical associations in soil compartments as based on using the three step BCR (now...... the Measurements and Testing Programme of the European Commission) sequential extraction scheme. Employing a peristaltic pump as liquid driver, alternate directional flows of the extractants are used to overcome compression of the solid particles within the extraction unit to ensure a steady partitioning flow rate...... and thus to maintain constant operationally defined extraction conditions. The proposed flow set-up is proven to allow for trouble-free handling of soil samples up to 1 g and flow rates ≤ 10 mL min–1. The miniaturized extraction system was coupled to ICP-MS through a flow injection interface in order...

  12. Direct introduction of volatile carbon compounds into the spray chamber of an inductively coupled plasma mass spectrometer: Sensitivity enhancement for selenium

    International Nuclear Information System (INIS)

    Kovacevic, Miroslav; Goessler, Walter

    2005-01-01

    The effect of signal enhancement of elements with ionization potentials in the range from 9 to 11 eV by carbon-containing compounds is a well-known phenomenon in inductively coupled plasma mass spectrometry (ICPMS). It has traditionally been exploited through the addition of organic solvents to the sample matrix or to the mobile phase to improve sensitivity. In the present work, aqueous solutions of volatile carbon compounds (acetone, methanol and acetic acid) were directly introduced into the thermostatted spray chamber rather than being added to the sample matrix. It is presumed that no aerosol is produced from these solutions and only vapors of organic compounds are swept into the plasma together with the sample aerosol. When a 0.40 mol l -1 aqueous solution of acetone was introduced directly into the spray chamber, the signals for arsenic and selenium were enhanced by a factor of 4.2. The usefulness of this approach was demonstrated through the achievement of lower instrumental detection limits for selenium at m/z 82 (0.1 ng ml -1 ) compared to the system without direct introduction of volatile carbon compounds (0.5 ng ml -1 ). The method was successfully applied in the determination of traces of selenium in natural water, urine and bovine liver reference material

  13. Disentangling Higgs-Top Couplings in Associated Production

    CERN Document Server

    Ellis, John; Sakurai, Kazuki; Takeuchi, Michihisa

    2014-01-01

    In the presence of CP violation, the Higgs-top coupling may have both scalar and pseudoscalar components, $\\kappa_t$ and ${\\tilde \\kappa_t}$, which are bounded indirectly but only weakly by the present experimental constraints on the Higgs-gluon-gluon and Higgs-$\\gamma$-$\\gamma$ couplings, whereas upper limits on electric dipole moments provide strong additional indirect constraints on ${\\tilde \\kappa_t}$, if the Higgs-electron coupling is similar to that in the Standard Model and there are no cancellations with other contributions. We discuss methods to measure directly the scalar and pseudoscalar Higgs-top couplings by measurements of Higgs production in association with ${\\bar t} t$, single $t$ and single ${\\bar t}$ at the LHC. Measurements of the total cross sections are very sensitive to variations in the Higgs-top couplings that are consistent with the present indirect constraints, as are invariant mass distributions in ${\\bar t} t H$, $tH$ and ${\\bar t} H$ final states. We also investigate the addition...

  14. Palm oil mill effluent treatment using a two-stage microbial fuel cells system integrated with immobilized biological aerated filters.

    Science.gov (United States)

    Cheng, Jia; Zhu, Xiuping; Ni, Jinren; Borthwick, Alistair

    2010-04-01

    An integrated system of two-stage microbial fuel cells (MFCs) and immobilized biological aerated filters (I-BAFs) was used to treat palm oil mill effluent (POME) at laboratory scale. By replacing the conventional two-stage up-flow anaerobic sludge blanket (UASB) with a newly proposed upflow membrane-less microbial fuel cell (UML-MFC) in the integrated system, significant improvements on NH(3)-N removal were observed and direct electricity generation implemented in both MFC1 and MFC2. Moreover, the coupled iron-carbon micro-electrolysis in the cathode of MFC2 further enhanced treatment efficiency of organic compounds. The I-BAFs played a major role in further removal of NH(3)-N and COD. For influent COD and NH(3)-N of 10,000 and 125 mg/L, respectively, the final effluents COD and NH(3)-N were below 350 and 8 mg/L, with removal rates higher than 96.5% and 93.6%. The GC-MS analysis indicated that most of the contaminants were satisfactorily biodegraded by the integrated system. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. The dynamics of stress and fatigue across menopause: attractors, coupling, and resilience.

    Science.gov (United States)

    Taylor-Swanson, Lisa; Wong, Alexander E; Pincus, David; Butner, Jonathan E; Hahn-Holbrook, Jennifer; Koithan, Mary; Wann, Kathryn; Woods, Nancy F

    2018-04-01

    The objective of this study was to evaluate the regulatory dynamics between stress and fatigue experienced by women during the menopausal transition (MT) and early postmenopause (EPM). Fatigue and perceived stress are commonly experienced by women during the MT and EPM. We sought to discover relationships between these symptoms and to employ these symptoms as possible markers for resilience. Participants were drawn from the longitudinal Seattle Midlife Women's Health Study. Eligible women completed questionnaires on 60+ occasions (annual health reports and monthly health diaries) (n = 56 women). The total number of observations across the sample was 4,224. STRAW+10 criteria were used to stage women in either in late reproductive, early or late transition, or EPM stage. Change values were generated for fatigue and stress and analyzed with a multilevel structural equation model; slopes indicate how quickly a person returns to homeostasis after a perturbation. Coupling of stress and fatigue was modeled to evaluate resilience, the notion of maintaining stability during change. Eligible women were on average 35 years old (SD = 4.71), well educated, employed, married or partnered, and white. Fit indices suggested the model depicts the relationships of stress and fatigue (χ(9 df) = 7.638, P = 0.57, correction factor = 4.9244; root mean square error of approximation (RMSEA) 90% CI = 0.000 ≤ 0.000 ≤ 0.032; comparative fit index (CFI) = 1.00). A loss in model fit across stages suggests that the four stages differed in their dynamics (χΔ(12 df) = 21.181, P = .048). All stages showed fixed-point attractor dynamics: fatigue became less stable over time; stress generally became more stable over time. Coupling relationships of stress on fatigue show evidence for shifts in regulatory relationships with one another across the MT. Results are suggestive of general dysregulation via disruptions to coupling relationships of stress and

  16. DIFFICULTIES IN DETERMINING THE STAGE OF PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    I. V. Lukianov

    2014-07-01

    Full Text Available The choice of a technique of treatment of prostate cancer depends on the age of the patient, accompanying diseases and prevalence of tumoral process. The basic methods at an inspection stage at which the cancer stage is defined are: definition of prostate specific membrane antigen, rectal examination, results of the rectal ultrasound guided biopsy, prostate imaging methods and an estimation of a grade of a tumor. Nowadays one of the main directions of determining the treatment for various stages of tumor is the development of prognostic models based on the analysis of predictors for tumor expansion.

  17. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    Science.gov (United States)

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

  18. Charge correlation measurements of double-sided direct-coupled silicon mirostrip detectors

    International Nuclear Information System (INIS)

    Wood, M.L.; Kuehler, J.F.; Kalbfleisch, G.R.; Kaplan, D.H.; Skubic, P.; Lucas, A.D.; Wilburn, C.D.

    1991-01-01

    Charge correlation measurements of several Micron 38 mm by 58 mm by 300 micron thick double-sided DC-coupled microstripe detectors have been made. They have been bench tested with a Sr-90 source, with the detectors operated at -22C. The correlation of the charges collected from both the diode ('holes') and the ohmic ('electrons') stripes are equal within a signal to noise resolution of 20:1 (i.e., 1,200 electrons noise) using common-mode subtracted double-correlated sampling with the Berkeley SVXD readout chip

  19. The SU(3) running coupling from lattice gluons

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, C. [Edinburgh Univ. (United Kingdom). Dept. of Phys. and Astron.; UKQCD Collaboration

    1995-04-01

    We provide numerical results for the running coupling in SU(3) Yang-Mills theory as determined from an analysis of lattice two and three-point gluon correlation functions. The coupling is evaluated directly, from first principles, by defining suitable renormalisation constants from the lattice triple gluon vertex and gluon propagator. For momenta larger than 2GeV, the coupling is found to run according to the 2-loop asymptotic formula. The influence of lattice artifacts on the results appears negligible within the precision of our measurements, although further work on this point is in progress. ((orig.)).

  20. Semiconductor ring lasers coupled by a single waveguide

    Science.gov (United States)

    Coomans, W.; Gelens, L.; Van der Sande, G.; Mezosi, G.; Sorel, M.; Danckaert, J.; Verschaffelt, G.

    2012-06-01

    We experimentally and theoretically study the characteristics of semiconductor ring lasers bidirectionally coupled by a single bus waveguide. This configuration has, e.g., been suggested for use as an optical memory and as an optical neural network motif. The main results are that the coupling can destabilize the state in which both rings lase in the same direction, and it brings to life a state with equal powers at both outputs. These are both undesirable for optical memory operation. Although the coupling between the rings is bidirectional, the destabilization occurs due to behavior similar to an optically injected laser system.

  1. The construction of a model of the process of couples' forgiveness in emotion-focused therapy for couples.

    Science.gov (United States)

    Meneses, Catalina Woldarsky; Greenberg, Leslie S

    2011-10-01

    This study explored how forgiveness unfolds in the context of emotion-focused couples therapy (EFT-C) in eight cases of women betrayed by their partners. Forgiveness was defined as a process involving the reduction in negative feelings and the giving out of undeserved compassion. This was measured by changes in the pre- and posttreatment scores on the Enright Forgiveness Inventory, the Unfinished Business Resolution Scale, and a single item directly asking respondents to indicate their degree of forgiveness. A task analysis was performed to rigorously track the steps leading to forgiveness using videotapes of therapy sessions for eight couples. The performance of the four couples who forgave were compared with each other and then contrasted with the performance of another four couples who did not reach forgiveness at the end of therapy. Based on these observations, a model of the process of forgiveness in EFT-C and a process rating system were developed. © 2011 American Association for Marriage and Family Therapy.

  2. Elemental speciation via high-performance liquid chromatography combined with inductively coupled plasma atomic emission spectroscopic detection: application of a direct injection nebulizer

    International Nuclear Information System (INIS)

    LaFreniere, K.E; Fassel, V.A.; Eckels, D.E.

    1987-01-01

    An evaluation is presented of a direct injection nebulizer (DIN) interfaced to a high-performance liquid chromatograph (HPLC) with inductively coupled plasma atomic emission spectroscopic (ICP-AES) detection for simultaneous multielement speciation. The limits of detection (LODs) obtained with the DIN interface in the HPLC mode were found to be comparable to those obtained by continuous-flow sample introduction into the ICP, or inferior by up to only a factor of 4. In addition, the DIN allowed for the direct injection into the ICP of a variety of common HPLC solvents (up to 100% methanol, acetonitrile, methyl isobutyl ketone, pyridine, and water). The HPLC-DIN-ICP-AES system was compared to other HPLC-atomic spectroscopic detection techniques and was found to offer substantial improvement over the alternative on-line, detection methods in terms of LODs. Representative applications of the HPLC-DIN-ICP-AES system to the elemental speciation of coal process streams, shale oil, solvent refined coal, and crude oil are presented

  3. Vibration characteristics of two-stage planetary transmission system with thin-walled ring gear on elastic supports

    Science.gov (United States)

    Li, JianYing; Hu, QingChun; Zong, ChangFu; Zhu, TianJun; Zhang, ZeXing

    2018-03-01

    A dual-clutch and dual-speed planetary gears mechanism of a hybrid car coupled-system is taken as research subject, in which the ring gear of planet set II is a thin-walled structure and the clutch friction plates of planet set II are used as its elastic supports. Based on the lumped parameter-rigid elastic coupled dynamic model of two-stage planetary transmission system with thin-walled ring gear on elastic supports, the motion differential equations are established and the dynamic responses are solved by the Runge-Kutta method considering each stage internal and external time-varying mesh stiffness. The vibration displacements of each stage ring gear have been affected differently in time-domain, the translational vibration displacement of the ring gear of planet set I are obviously more than the torsional vibration displacement, but it is opposite for the ring gear of planet set II; The translational and torsional vibration responses of each stage ring gear arrive the peak in low-frequency. The analysis results of this paper can enrich the theoretical research of multistage planetary transmission and provide guidance for dynamic design.

  4. Coupled modes, frequencies and fields of a dielectric resonator and a cavity using coupled mode theory

    Science.gov (United States)

    Elnaggar, Sameh Y.; Tervo, Richard; Mattar, Saba M.

    2014-01-01

    Probes consisting of a dielectric resonator (DR) inserted in a cavity are important integral components of electron paramagnetic resonance (EPR) spectrometers because of their high signal-to-noise ratio. This article studies the behavior of this system, based on the coupling between its dielectric and cavity modes. Coupled-mode theory (CMT) is used to determine the frequencies and electromagnetic fields of this coupled system. General expressions for the frequencies and field distributions are derived for both the resulting symmetric and anti-symmetric modes. These expressions are applicable to a wide range of frequencies (from MHz to THz). The coupling of cavities and DRs of various sizes and their resonant frequencies are studied in detail. Since the DR is situated within the cavity then the coupling between them is strong. In some cases the coupling coefficient, κ, is found to be as high as 0.4 even though the frequency difference between the uncoupled modes is large. This is directly attributed to the strong overlap between the fields of the uncoupled DR and cavity modes. In most cases, this improves the signal to noise ratio of the spectrometer. When the DR and the cavity have the same frequency, the coupled electromagnetic fields are found to contain equal contributions from the fields of the two uncoupled modes. This situation is ideal for the excitation of the probe through an iris on the cavity wall. To verify and validate the results, finite element simulations are carried out. This is achieved by simulating the coupling between a cylindrical cavity's TE011 and the dielectric insert's TE01δ modes. Coupling between the modes of higher order is also investigated and discussed. Based on CMT, closed form expressions for the fields of the coupled system are proposed. These expressions are crucial in the analysis of the probe's performance.

  5. Ultrafast single-molecule photonics: Excited state dynamics in coherently coupled complexes

    International Nuclear Information System (INIS)

    Hernando, Jordi; Hoogenboom, Jacob; Dijk, Erik van; Garcia-Parajo, Maria; Hulst, Niek F. van

    2008-01-01

    We present a single-molecule study on femtosecond dynamics in multichromophoric systems, combining fs pump-probe, emission-spectra and fluorescence-lifetime analysis. The ultrafast fs approach gives direct information on the initial exciton dynamics after excitation. The lifetime data show superradiance, a direct measure for the extent of the coherent coupling and static disorder. The spectra finally reveal the role of exciton-phonon coupling. At the single-molecule level a wide range of exciton delocalization lengths and energy redistribution times is revealed

  6. Ultrafast single-molecule photonics: Excited state dynamics in coherently coupled complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hernando, Jordi [Dept. de Quimica, Universitat Autonoma Barcelona, 08193 Cerdanyola del Valles (Spain); Hoogenboom, Jacob [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain); Dijk, Erik van [Applied Optics Group, MESA Institute for Nanotechnology, University of Twente, 7500AE Enschede (Netherlands); Garcia-Parajo, Maria [IBEC-Institute of BioEngineering of Catalunya, 08028 Barcelona (Spain); ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08015 Barcelona (Spain); Hulst, Niek F. van [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona (Spain) and ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08015 Barcelona (Spain)], E-mail: Niek.vanHulst@ICFO.es

    2008-05-15

    We present a single-molecule study on femtosecond dynamics in multichromophoric systems, combining fs pump-probe, emission-spectra and fluorescence-lifetime analysis. The ultrafast fs approach gives direct information on the initial exciton dynamics after excitation. The lifetime data show superradiance, a direct measure for the extent of the coherent coupling and static disorder. The spectra finally reveal the role of exciton-phonon coupling. At the single-molecule level a wide range of exciton delocalization lengths and energy redistribution times is revealed.

  7. Dynamic behaviors in directed networks

    International Nuclear Information System (INIS)

    Park, Sung Min; Kim, Beom Jun

    2006-01-01

    Motivated by the abundance of directed synaptic couplings in a real biological neuronal network, we investigate the synchronization behavior of the Hodgkin-Huxley model in a directed network. We start from the standard model of the Watts-Strogatz undirected network and then change undirected edges to directed arcs with a given probability, still preserving the connectivity of the network. A generalized clustering coefficient for directed networks is defined and used to investigate the interplay between the synchronization behavior and underlying structural properties of directed networks. We observe that the directedness of complex networks plays an important role in emerging dynamical behaviors, which is also confirmed by a numerical study of the sociological game theoretic voter model on directed networks

  8. Measuring Relative Coupling Strength in Circadian Systems.

    Science.gov (United States)

    Schmal, Christoph; Herzog, Erik D; Herzel, Hanspeter

    2018-02-01

    Modern imaging techniques allow the monitoring of circadian rhythms of single cells. Coupling between these single cellular circadian oscillators can generate coherent periodic signals on the tissue level that subsequently orchestrate physiological outputs. The strength of coupling in such systems of oscillators is often unclear. In particular, effects on coupling strength by varying cell densities, by knockouts, and by inhibitor applications are debated. In this study, we suggest to quantify the relative coupling strength via analyzing period, phase, and amplitude distributions in ensembles of individual circadian oscillators. Simulations of different oscillator networks show that period and phase distributions become narrower with increasing coupling strength. Moreover, amplitudes can increase due to resonance effects. Variances of periods and phases decay monotonically with coupling strength, and can serve therefore as measures of relative coupling strength. Our theoretical predictions are confirmed by studying recently published experimental data from PERIOD2 expression in slices of the suprachiasmatic nucleus during and after the application of tetrodotoxin (TTX). On analyzing the corresponding period, phase, and amplitude distributions, we can show that treatment with TTX can be associated with a reduced coupling strength in the system of coupled oscillators. Analysis of an oscillator network derived directly from the data confirms our conclusions. We suggest that our approach is also applicable to quantify coupling in fibroblast cultures and hepatocyte networks, and for social synchronization of circadian rhythmicity in rodents, flies, and bees.

  9. Coherent Vortices in Strongly Coupled Liquids

    International Nuclear Information System (INIS)

    Ashwin, J.; Ganesh, R.

    2011-01-01

    Strongly coupled liquids are ubiquitous in both nature and laboratory plasma experiments. They are unique in the sense that their average potential energy per particle dominates over the average kinetic energy. Using ''first principles'' molecular dynamics (MD) simulations, we report for the first time the emergence of isolated coherent tripolar vortices from the evolution of axisymmetric flows in a prototype two-dimensional (2D) strongly coupled liquid, namely, the Yukawa liquid. Linear growth rates directly obtained from MD simulations are compared with a generalized hydrodynamic model. Our MD simulations reveal that the tripolar vortices persist over several turn over times and hence may be observed in strongly coupled liquids such as complex plasma, liquid metals and astrophysical systems such as white dwarfs and giant planetary interiors, thereby making the phenomenon universal.

  10. Coherent Vortices in Strongly Coupled Liquids

    Science.gov (United States)

    Ashwin, J.; Ganesh, R.

    2011-04-01

    Strongly coupled liquids are ubiquitous in both nature and laboratory plasma experiments. They are unique in the sense that their average potential energy per particle dominates over the average kinetic energy. Using “first principles” molecular dynamics (MD) simulations, we report for the first time the emergence of isolated coherent tripolar vortices from the evolution of axisymmetric flows in a prototype two-dimensional (2D) strongly coupled liquid, namely, the Yukawa liquid. Linear growth rates directly obtained from MD simulations are compared with a generalized hydrodynamic model. Our MD simulations reveal that the tripolar vortices persist over several turn over times and hence may be observed in strongly coupled liquids such as complex plasma, liquid metals and astrophysical systems such as white dwarfs and giant planetary interiors, thereby making the phenomenon universal.

  11. Hydraulic Fracture Induced Seismicity During A Multi-Stage Pad Completion in Western Canada: Evidence of Activation of Multiple, Parallel Faults

    Science.gov (United States)

    Maxwell, S.; Garrett, D.; Huang, J.; Usher, P.; Mamer, P.

    2017-12-01

    Following reports of injection induced seismicity in the Western Canadian Sedimentary Basin, regulators have imposed seismic monitoring and traffic light protocols for fracturing operations in specific areas. Here we describe a case study in one of these reservoirs, the Montney Shale in NE British Columbia, where induced seismicity was monitored with a local array during multi-stage hydraulic fracture stimulations on several wells from a single drilling pad. Seismicity primarily occurred during the injection time periods, and correlated with periods of high injection rates and wellhead pressures above fracturing pressures. Sequential hydraulic fracture stages were found to progressively activate several parallel, critically-stressed faults, as illuminated by multiple linear hypocenter patterns in the range between Mw 1 and 3. Moment tensor inversion of larger events indicated a double-couple mechanism consistent with the regional strike-slip stress state and the hypocenter lineations. The critically-stressed faults obliquely cross the well paths which were purposely drilled parallel to the minimum principal stress direction. Seismicity on specific faults started and stopped when fracture initiation points of individual injection stages were proximal to the intersection of the fault and well. The distance ranges when the seismicity occurs is consistent with expected hydraulic fracture dimensions, suggesting that the induced fault slip only occurs when a hydraulic fracture grows directly into the fault and the faults are temporarily exposed to significantly elevated fracture pressures during the injection. Some faults crossed multiple wells and the seismicity was found to restart during injection of proximal stages on adjacent wells, progressively expanding the seismogenic zone of the fault. Progressive fault slip is therefore inferred from the seismicity migrating further along the faults during successive injection stages. An accelerometer was also deployed close

  12. A Review of Application Building Information Modeling (BIM) During Pre-Construction Stage: Retrospective and Future Directions

    Science.gov (United States)

    Edra Nisa Lau, Santi; Zakaria, Rozana; Aminudin, Eeydzah; Saar, Chai Chang; Yusof, Aswadi; Fatihi Hafifi Che Wahid, Che Muhammad

    2018-04-01

    Pre-construction is one of the biggest areas of risk and uncertainty in construction project as it deals with subsurface ground conditions information. The amount of detail data needed in pre-construction especially for existing data modelling and site analysis should be sufficient enough to ensure that significant risks could not reasonably be anticipated. Current practicing method in interpreting data during this stage tasks reveal limitation. Construction industry faced many obstacles due to the depends on the traditional practice; paper-based document which missing and redundant data always happened. In recent years, there has been a shift in construction where people move to BIM application because of its potential to reduce the problem faced by infrastructure world. BIM has become a successful technology and widely popular in the construction world especially in developed countries because of its potential. Nowadays, people are moving one step ahead in BIM which is adoption of BIM during pre-construction stage. Thus, this paper review studies centered on BIM-integrated modelling during preconstruction stage. But there is lack of practical researches have been made during this stage. Although a large number of studies on BIM have been conducted in the past decade, a lack of consensus remains among researchers and practitioners regarding the applications of BIM during pre-construction stage, the availability of subsequent data integration tool for geotechnical activity. A comprehensive literature review was conducted for data collection and analysis. After in-depth review of journal articles widely cover the application of BIM, this study summarizes an overview and critical reflection of geotechnical data integration using BIM during pre-construction stage. The results are useful for the identification of research clusters and topics in the BIM community.

  13. Parallel coupling of symmetric and asymmetric exclusion processes

    International Nuclear Information System (INIS)

    Tsekouras, K; Kolomeisky, A B

    2008-01-01

    A system consisting of two parallel coupled channels where particles in one of them follow the rules of totally asymmetric exclusion processes (TASEP) and in another one move as in symmetric simple exclusion processes (SSEP) is investigated theoretically. Particles interact with each other via hard-core exclusion potential, and in the asymmetric channel they can only hop in one direction, while on the symmetric lattice particles jump in both directions with equal probabilities. Inter-channel transitions are also allowed at every site of both lattices. Stationary state properties of the system are solved exactly in the limit of strong couplings between the channels. It is shown that strong symmetric couplings between totally asymmetric and symmetric channels lead to an effective partially asymmetric simple exclusion process (PASEP) and properties of both channels become almost identical. However, strong asymmetric couplings between symmetric and asymmetric channels yield an effective TASEP with nonzero particle flux in the asymmetric channel and zero flux on the symmetric lattice. For intermediate strength of couplings between the lattices a vertical-cluster mean-field method is developed. This approximate approach treats exactly particle dynamics during the vertical transitions between the channels and it neglects the correlations along the channels. Our calculations show that in all cases there are three stationary phases defined by particle dynamics at entrances, at exits or in the bulk of the system, while phase boundaries depend on the strength and symmetry of couplings between the channels. Extensive Monte Carlo computer simulations strongly support our theoretical predictions. Theoretical calculations and computer simulations predict that inter-channel couplings have a strong effect on stationary properties. It is also argued that our results might be relevant for understanding multi-particle dynamics of motor proteins

  14. Efficacy and safety of direct-acting antivirals-based antiviral therapies for hepatitis C virus patients with stage 4-5 chronic kidney disease: a meta-analysis.

    Science.gov (United States)

    Li, Tao; Qu, Yundong; Guo, Ying; Wang, Yan; Wang, Lei

    2017-07-01

    The aim of this study was to assess the efficacy and safety of direct-acting antivirals (DAA)-based antiviral therapies for HCV patients with stage 4-5 chronic kidney disease. We conducted a systematic literature search in PubMed, EMBASE, Web of Science, and CENTRAL on the Cochrane Library without time and language limitations. The search strategy used was "(End stage renal disease OR chronic kidney failure OR severe renal impairment OR chronic kidney disease OR dialysis) AND (sofosbuvir OR simeprevir OR grazoprevir OR elbasvir OR ombitasvir OR paritaprevir OR ritonavir OR dasabuvir OR daclatasvir OR asuparevir OR direct-acting antiviral OR DAA)". Sustained virologic response at 12 weeks after the end of treatment (SVR12), adverse events (AEs) and/or serious adverse events (SAEs) with 95% confidence intervals (CI) were pooled. Eleven studies, comprising a total of 264 patients were included for our meta-analysis. The pooled SVR12 rate were 93.2% (95% CI 89.9%-95.9%, I 2 =0.0%), 89.4% (95% CI 82.0%-95.0%, I 2 =0.0%) and 94.7% (95% CI 91.0%-97.5%, I 2 =0.0%) in total population, patients with sofosbuvir-based therapies and patients with non-sofosbuvir-based therapies respectively. For HCV genotype 1 patients, the pooled SVR12 rate was 93.1% (95% CI 88.3%-96.7%, I 2 =20.0%). The pooled incidence of SAEs was 12.1% (95% CI 6.2%-19.7%, I 2 =55.0%). The pooled discontinuation rate because of AEs or SAEs in our meta-analysis was 2.2% (95% CI 0.8%-4.4%, I 2 =0.0%). DAA-based antiviral therapies are effective and well-tolerated for HCV patients with stage 4-5 chronic kidney disease. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Thermally-driven Coupled THM Processes in Shales

    Science.gov (United States)

    Rutqvist, J.

    2017-12-01

    Temperature changes can trigger strongly coupled thermal-hydrological-mechanical (THM) processes in shales that are important to a number of subsurface energy applications, including geologic nuclear waste disposal and hydrocarbon extraction. These coupled processes include (1) direct pore-volume couplings, by thermal expansion of trapped pore-fluid that triggers instantaneous two-way couplings between pore fluid pressure and mechanical deformation, and (2) indirect couplings in terms of property changes, such as changes in mechanical stiffness, strength, and permeability. Direct pore-volume couplings have been studied in situ during borehole heating experiments in shale (or clay stone) formations at Mont Terri and Bure underground research laboratories in Switzerland and France. Typically, the temperature changes are accompanied with a rapid increase in pore pressure followed by a slower decrease towards initial (pre-heating) pore pressure. Coupled THM modeling of these heater tests shows that the pore pressure increases because the thermal expansion coefficient of the fluid is much higher than that of the porous clay stone. Such thermal pressurization induces fluid flow away from the pressurized area towards areas of lower pressure. The rate of pressure increase and magnitude of peak pressure depends on the rate of heating, pore-compressibility, and permeability of the shale. Modeling as well as laboratory experiments have shown that if the pore pressure increase is sufficiently large it could lead to fracturing of the shale or shear slip along pre-existing bedding planes. Another set of data and observations have been collected associated with studies related to concentrated heating and cooling of oil-shales and shale-gas formations. Heating may be used to enhance production from tight oil-shale, whereas thermal stimulation has been attempted for enhanced shale-gas extraction. Laboratory experiments on shale have shown that strength and elastic deformation

  16. Early and progressive impairment of spinal blood flow-glucose metabolism coupling in motor neuron degeneration of ALS model mice.

    Science.gov (United States)

    Miyazaki, Kazunori; Masamoto, Kazuto; Morimoto, Nobutoshi; Kurata, Tomoko; Mimoto, Takahumi; Obata, Takayuki; Kanno, Iwao; Abe, Koji

    2012-03-01

    The exact mechanism of selective motor neuron death in amyotrophic lateral sclerosis (ALS) remains still unclear. In the present study, we performed in vivo capillary imaging, directly measured spinal blood flow (SBF) and glucose metabolism, and analyzed whether if a possible flow-metabolism coupling is disturbed in motor neuron degeneration of ALS model mice. In vivo capillary imaging showed progressive decrease of capillary diameter, capillary density, and red blood cell speed during the disease course. Spinal blood flow was progressively decreased in the anterior gray matter (GM) from presymptomatic stage to 0.80-fold of wild-type (WT) mice, 0.61 at early-symptomatic, and 0.49 at end stage of the disease. Local spinal glucose utilization (LSGU) was transiently increased to 1.19-fold in anterior GM at presymptomatic stage, which in turn progressively decreased to 0.84 and 0.60 at early-symptomatic and end stage of the disease. The LSGU/SBF ratio representing flow-metabolism uncoupling (FMU) preceded the sequential pathological changes in the spinal cord of ALS mice and was preferentially found in the affected region of ALS. The present study suggests that this early and progressive FMU could profoundly involve in the whole disease process as a vascular factor of ALS pathology, and could also be a potential target for therapeutic intervention of ALS.

  17. EEG-NIRS based assessment of neurovascular coupling during anodal transcranial direct current stimulation--a stroke case series.

    Science.gov (United States)

    Dutta, Anirban; Jacob, Athira; Chowdhury, Shubhajit Roy; Das, Abhijit; Nitsche, Michael A

    2015-04-01

    A method for electroencephalography (EEG) - near-infrared spectroscopy (NIRS) based assessment of neurovascular coupling (NVC) during anodal transcranial direct current stimulation (tDCS). Anodal tDCS modulates cortical neural activity leading to a hemodynamic response, which was used to identify impaired NVC functionality. In this study, the hemodynamic response was estimated with NIRS. NIRS recorded changes in oxy-hemoglobin (HbO2) and deoxy-hemoglobin (Hb) concentrations during anodal tDCS-induced activation of the cortical region located under the electrode and in-between the light sources and detectors. Anodal tDCS-induced alterations in the underlying neuronal current generators were also captured with EEG. Then, a method for the assessment of NVC underlying the site of anodal tDCS was proposed that leverages the Hilbert-Huang Transform. The case series including four chronic (>6 months) ischemic stroke survivors (3 males, 1 female from age 31 to 76) showed non-stationary effects of anodal tDCS on EEG that correlated with the HbO2 response. Here, the initial dip in HbO2 at the beginning of anodal tDCS corresponded with an increase in the log-transformed mean-power of EEG within 0.5Hz-11.25Hz frequency band. The cross-correlation coefficient changed signs but was comparable across subjects during and after anodal tDCS. The log-transformed mean-power of EEG lagged HbO2 response during tDCS but then led post-tDCS. This case series demonstrated changes in the degree of neurovascular coupling to a 0.526 A/m(2) square-pulse (0-30 s) of anodal tDCS. The initial dip in HbO2 needs to be carefully investigated in a larger cohort, for example in patients with small vessel disease.

  18. NDDP multi-stage flash desalination process simulator design process optimization

    International Nuclear Information System (INIS)

    Sashi Kumar, G.N.; Mahendra, A.K.; Sanyal, A.; Gouthaman, G.

    2009-03-01

    The improvement of NDDP-MSF plant's performance ratio (PR) from design value of 9.0 to 13.1 was achieved by optimizing the plant's operating parameters within the feasible zone of operation. This plant has 20% excess heat transfer area over the design condition which helped us to get a PR of 15.1 after optimization. Thus we have obtained, (1) A 45% increase in the output over design value by the optimization carried out with design heat transfer area. (2) A 68% increase in the output over design value by the optimization carried out with increased heat transfer area. This report discusses the approach, methodology and results of the optimization study carried out. A simulator, MSFSIM which predicts the performance of a multi-stage flash (MSF) desalination plant has been coupled with Genetic Algorithm (GA) optimizer. Exhaustive optimization case studies have been conducted on this plant with an objective to increase the performance ratio (PR). The steady state optimization performed was based on obtaining the best stage wise pressure profile to enhance thermal efficiency which in-turn improves the performance ratio. Apart from this, the recirculating brine flow rate was also optimized. This optimization study enabled us to increase the PR of NDDP-MSF plant from design value of 9.0 to an optimized value 13.1. The actual plant is provided with 20% additional heat transfer area over and above the design heat transfer area. Optimization with this additional heat transfer area has taken the PR to 15.1. A desire to maintain equal flashing rates in all of the stages (a feature required for long life of the plant and to avoid cascading effect of non-flashing triggered by any stage) of the MSF plant has also been achieved. The deviation in the flashing rates within stages has been reduced. The startup characteristic of the plant (i.e the variation of stage pressure and the variation of recirculation flow rate with time), have been optimized with a target to minimize the

  19. Comparative spring-staging ecology of sympatric arctic-nesting geese in south-central Nebraska

    Science.gov (United States)

    Pearse, Aaron T.; Krapu, Gary L.; Cox, Robert R.

    2013-01-01

    The Rainwater Basin in Nebraska has been a historic staging area for midcontinent greater white-fronted geese (Anser albifrons frontalis) since the 1950s and, in the mid-1990s, millions of midcontinent lesser snow geese (Chen caerulescens caerulescens) expanded their spring migration route to include this region. In response to speculation that snow geese may be in direct competition with white-fronted geese, we compared staging ecology by quantifying diet, habitat use, movement patterns, and time budgets during springs 1998–1999. Collected white-fronted geese (n  =  190) and snow geese (n  =  203) consumed primarily corn (Zea mays; 97–98% aggregate dry mass) while staging in Nebraska; thus, diet overlap was nearly complete. Both species used cornfields most frequently during the morning (54–55%) and wetlands more during the afternoon (51–65%). When found grouped together, snow goose abundance was greater than white-fronted goose abundance by an average of 57 times (se  =  11, n  =  131 groups) in crop fields and 28 times (se  =  9, n  =  84 groups) in wetlands. Snow geese and white-fronted geese flew similar distances between roosting and feeding sites, leaving and returning to wetland roost sties at similar times in mornings and afternoons. Overlap in habitat-specific time budgets was high; resting was the most common behavior on wetlands, and foraging was a common behavior in fields. We observed 111 interspecific agonistic interactions while observing white-fronted and snow geese. White-fronted geese initiated and dominated more interactions with other waterfowl species than did snow geese (32 vs. 14%). Certain aspects of spring-staging niches (i.e., diet, habitat use, movement patterns, and habitat-specific behavior) of white-fronted and snow geese overlapped greatly at this mid-latitude staging site, creating opportunity for potential food- and habitat-based competition between species. Snow geese did not consistently dominate

  20. Design and control of a decoupled two degree of freedom translational parallel micro-positioning stage.

    Science.gov (United States)

    Lai, Lei-Jie; Gu, Guo-Ying; Zhu, Li-Min

    2012-04-01

    This paper presents a novel decoupled two degrees of freedom (2-DOF) translational parallel micro-positioning stage. The stage consists of a monolithic compliant mechanism driven by two piezoelectric actuators. The end-effector of the stage is connected to the base by four independent kinematic limbs. Two types of compound flexure module are serially connected to provide 2-DOF for each limb. The compound flexure modules and mirror symmetric distribution of the four limbs significantly reduce the input and output cross couplings and the parasitic motions. Based on the stiffness matrix method, static and dynamic models are constructed and optimal design is performed under certain constraints. The finite element analysis results are then given to validate the design model and a prototype of the XY stage is fabricated for performance tests. Open-loop tests show that maximum static and dynamic cross couplings between the two linear motions are below 0.5% and -45 dB, which are low enough to utilize the single-input-single-out control strategies. Finally, according to the identified dynamic model, an inversion-based feedforward controller in conjunction with a proportional-integral-derivative controller is applied to compensate for the nonlinearities and uncertainties. The experimental results show that good positioning and tracking performances are achieved, which verifies the effectiveness of the proposed mechanism and controller design. The resonant frequencies of the loaded stage at 2 kg and 5 kg are 105 Hz and 68 Hz, respectively. Therefore, the performance of the stage is reasonably good in term of a 200 N load capacity. © 2012 American Institute of Physics

  1. Travelling wave solutions of generalized coupled Zakharov–Kuznetsov and dispersive long wave equations

    Directory of Open Access Journals (Sweden)

    M. Arshad

    Full Text Available In this manuscript, we constructed different form of new exact solutions of generalized coupled Zakharov–Kuznetsov and dispersive long wave equations by utilizing the modified extended direct algebraic method. New exact traveling wave solutions for both equations are obtained in the form of soliton, periodic, bright, and dark solitary wave solutions. There are many applications of the present traveling wave solutions in physics and furthermore, a wide class of coupled nonlinear evolution equations can be solved by this method. Keywords: Traveling wave solutions, Elliptic solutions, Generalized coupled Zakharov–Kuznetsov equation, Dispersive long wave equation, Modified extended direct algebraic method

  2. Two-Stage Power Factor Corrected Power Supplies: The Low Component-Stress Approach

    DEFF Research Database (Denmark)

    Petersen, Lars; Andersen, Michael Andreas E.

    2002-01-01

    The discussion concerning the use of single-stage contra two-stage PFC solutions has been going on for the last decade and it continues. The purpose of this paper is to direct the focus back on how the power is processed and not so much as to the number of stages or the amount of power processed...

  3. Maxima and minima of the orientation phenomena for direct 1s→2p+-1 electron-ion collisional excitations in weakly coupled plasmas

    International Nuclear Information System (INIS)

    Yoon Jung-Sik; Jung Young-Dae

    1999-01-01

    Orientation phenomena for direct 1s→2p +-1 electron-ion collisional excitations in weakly coupled plasma are investigated using the semiclassical trajectory method including the close-encounter effects. In weakly coupled plasmas, the electron-ion interaction potential is given by the classical nonspherical Debye-Hueckel model. The semiclassical screened hyperbolic-orbit trajectory method is applied to describe the motion of the projectile electron in order to investigate the variation of the orientation parameter as a function of the impact parameter, projectile energy, and Debye length. A comparison is also given for the hyperbolic-orbit and straight-line trajectory methods. The results show that the orientation parameters obtained by the hyperbolic-orbit trajectory method have maxima and minima for small impact parameter regions. In other words, there are complete 1s→2p +1 (maxima) and complete 1s→2p -1 (minima) transitions for certain impact parameters. These maxima cannot be found using the straight-line trajectory method. The variation of the propensity of the 1s→2p -1 transitions due to the plasma screening effects on the atomic wave functions is also discussed

  4. Delayed Single Stage Perineal Posterior Urethroplasty.

    Science.gov (United States)

    Ali, Shahzad; Shahnawaz; Shahzad, Iqbal; Baloch, Muhammad Umar

    2015-06-01

    To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Descriptive case series. Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patient's age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3%) experienced recurrent stricture during first 10 months. Five (16.6%) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6%) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3% with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures.

  5. Inferring the Directionality of Coupling with Conditional Mutual Information

    Czech Academy of Sciences Publication Activity Database

    Vejmelka, Martin; Paluš, Milan

    2008-01-01

    Roč. 77, - (2008), Art.no.-026214 ISSN 1539-3755 EU Projects: European Commission(XE) 517133 - BRACCIA Institutional research plan: CEZ:AV0Z10300504 Keywords : directionality * chaotic oscillators * time series analysis * information theory * phase dynamics Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.508, year: 2008

  6. Ultrafast hydrogen exchange reveals specific structural events during the initial stages of folding of cytochrome c.

    Science.gov (United States)

    Fazelinia, Hossein; Xu, Ming; Cheng, Hong; Roder, Heinrich

    2014-01-15

    Many proteins undergo a sharp decrease in chain dimensions during early stages of folding, prior to the rate-limiting step in folding. However, it remains unclear whether compact states are the result of specific folding events or a general hydrophobic collapse of the poly peptide chain driven by the change in solvent conditions. To address this fundamental question, we extended the temporal resolution of NMR-detected H/D exchange labeling experiments into the microsecond regime by adopting a microfluidics approach. By observing the competition between H/D exchange and folding as a function of labeling pH, coupled with direct measurement of exchange rates in the unfolded state, we were able to monitor hydrogen-bond formation for over 50 individual backbone NH groups within the initial 140 microseconds of folding of horse cytochrome c. Clusters of solvent-shielded amide protons were observed in two α-helical segments in the C-terminal half of the protein, while the N-terminal helix remained largely unstructured, suggesting that proximity in the primary structure is a major factor in promoting helix formation and association at early stages of folding, while the entropically more costly long-range contacts between the N- and C-terminal helices are established only during later stages. Our findings clearly indicate that the initial chain condensation in cytochrome c is driven by specific interactions among a subset of α-helical segments rather than a general hydrophobic collapse.

  7. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

  8. Coupling-parameter expansion in thermodynamic perturbation theory.

    Science.gov (United States)

    Ramana, A Sai Venkata; Menon, S V G

    2013-02-01

    An approach to the coupling-parameter expansion in the liquid state theory of simple fluids is presented by combining the ideas of thermodynamic perturbation theory and integral equation theories. This hybrid scheme avoids the problems of the latter in the two phase region. A method to compute the perturbation series to any arbitrary order is developed and applied to square well fluids. Apart from the Helmholtz free energy, the method also gives the radial distribution function and the direct correlation function of the perturbed system. The theory is applied for square well fluids of variable ranges and compared with simulation data. While the convergence of perturbation series and the overall performance of the theory is good, improvements are needed for potentials with shorter ranges. Possible directions for further developments in the coupling-parameter expansion are indicated.

  9. Direct Photonic-Plasmonic Coupling and Routing in Single Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Rouxue; Pausauskie, Peter; Huang, Jiaxing; Yang, Piedong

    2009-10-20

    Metallic nanoscale structures are capable of supporting surface plasmon polaritons (SPPs), propagating collective electron oscillations with tight spatial confinement at the metal surface. SPPs represent one of the most promising structures to beat the diffraction limit imposed by conventional dielectric optics. Ag nano wires have drawn increasing research attention due to 2D sub-100 nm mode confinement and lower losses as compared with fabricated metal structures. However, rational and versatile integration of Ag nanowires with other active and passive optical components, as well as Ag nanowire based optical routing networks, has yet to be achieved. Here, we demonstrate that SPPs can be excited simply by contacting a silver nanowire with a SnO2 nanoribbon that serves both as an unpolarized light source and a dielectric waveguide. The efficient coupling makes it possible to measure the propagation-distance-dependent waveguide spectra and frequency-dependent propagation length on a single Ag nanowire. Furthermore, we have demonstrated prototypical photonic-plasmonic routing devices, which are essential for incorporating low-loss Ag nanowire waveguides as practical components into high-capacity photonic circuits.

  10. Pure spin current manipulation in antiferromagnetically exchange coupled heterostructures

    Science.gov (United States)

    Avilés-Félix, L.; Butera, A.; González-Chávez, D. E.; Sommer, R. L.; Gómez, J. E.

    2018-03-01

    We present a model to describe the spin currents generated by ferromagnet/spacer/ferromagnet exchange coupled trilayer systems and heavy metal layers with strong spin-orbit coupling. By exploiting the magnitude of the exchange coupling (oscillatory RKKY-like coupling) and the spin-flop transition in the magnetization process, it has been possible to produce spin currents polarized in arbitrary directions. The spin-flop transition of the trilayer system originates pure spin currents whose polarization vector depends on the exchange field and the magnetization equilibrium angles. We also discuss a protocol to control the polarization sign of the pure spin current injected into the metallic layer by changing the initial conditions of magnetization of the ferromagnetic layers previously to the spin pumping and inverse spin Hall effect experiments. The small differences in the ferromagnetic layers lead to a change in the magnetization vector rotation that permits the control of the sign of the induced voltage components due to the inverse spin Hall effect. Our results can lead to important advances in hybrid spintronic devices with new functionalities, particularly, the ability to control microscopic parameters such as the polarization direction and the sign of the pure spin current through the variation of macroscopic parameters, such as the external magnetic field or the thickness of the spacer in antiferromagnetic exchange coupled systems.

  11. Direct diode lasers with comparable beam quality to fiber, CO2, and solid state lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Kaiman, Michael; Overman, Robert; Glenn, John D.; Tayebati, Parviz

    2012-03-01

    TeraDiode has produced kW-class ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 2,040 W from a 50 μm core diameter, 0.15 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.75 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 2-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers.

  12. Coupling sequential injection on-line preconcentration using a PTFE beads packed column to direct injection nebulization inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection on-line preconcentration procedure for trace metals by using a PTFE bead-packed microcolumn coupled to ICP-MS is described, and used for simultaneous analyses of cadmium and lead. In dilute nitric acid (0.5%, v/v), neutral complexes between the analytes...

  13. Cost analysis of surgically treated pressure sores stage III and IV.

    Science.gov (United States)

    Filius, A; Damen, T H C; Schuijer-Maaskant, K P; Polinder, S; Hovius, S E R; Walbeehm, E T

    2013-11-01

    Health-care costs associated with pressure sores are significant and their financial burden is likely to increase even further. The aim of this study was to analyse the direct medical costs of hospital care for surgical treatment of pressure sores stage III and IV. We performed a retrospective chart study of patients who were surgically treated for stage III and IV pressure sores between 2007 and 2010. Volumes of health-care use were obtained for all patients and direct medical costs were subsequently calculated. In addition, we evaluated the effect of location and number of pressure sores on total costs. A total of 52 cases were identified. Average direct medical costs in hospital were €20,957 for the surgical treatment of pressure sores stage III or IV; average direct medical costs for patients with one pressure sore on an extremity (group 1, n = 5) were €30,286, €10,113 for patients with one pressure sore on the trunk (group 2, n = 32) and €40,882 for patients with multiple pressure sores (group 3, n = 15). The additional costs for patients in group 1 and group 3 compared to group 2 were primarily due to longer hospitalisation. The average direct medical costs for surgical treatment of pressure sores stage III and IV were high. Large differences in costs were related to the location and number of pressure sores. Insight into the distribution of these costs allows identification of high-risk patients and enables the development of specific cost-reducing measures. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  14. A real nonlinear integrable couplings of continuous soliton hierarchy and its Hamiltonian structure

    International Nuclear Information System (INIS)

    Yu Fajun

    2011-01-01

    Some integrable coupling systems of existing papers are linear integrable couplings. In the Letter, beginning with Lax pairs from special non-semisimple matrix Lie algebras, we establish a scheme for constructing real nonlinear integrable couplings of continuous soliton hierarchy. A direct application to the AKNS spectral problem leads to a novel nonlinear integrable couplings, then we consider the Hamiltonian structures of nonlinear integrable couplings of AKNS hierarchy with the component-trace identity. - Highlights: → We establish a scheme to construct real nonlinear integrable couplings. → We obtain a novel nonlinear integrable couplings of AKNS hierarchy. → Hamiltonian structure of nonlinear integrable couplings AKNS hierarchy is presented.

  15. runDM: Running couplings of Dark Matter to the Standard Model

    Science.gov (United States)

    D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

    2018-02-01

    runDM calculates the running of the couplings of Dark Matter (DM) to the Standard Model (SM) in simplified models with vector mediators. By specifying the mass of the mediator and the couplings of the mediator to SM fields at high energy, the code can calculate the couplings at low energy, taking into account the mixing of all dimension-6 operators. runDM can also extract the operator coefficients relevant for direct detection, namely low energy couplings to up, down and strange quarks and to protons and neutrons.

  16. Commercialization of Micro-fabrication of Antenna-Coupled Transition Edge Sensor Bolometer Detectors for Studies of the Cosmic Microwave Background

    Science.gov (United States)

    Suzuki, Aritoki; Bebek, Chris; Garcia-Sciveres, Maurice; Holland, Stephen; Kusaka, Akito; Lee, Adrian T.; Palaio, Nicholas; Roe, Natalie; Steinmetz, Leo

    2018-04-01

    We report on the development of commercially fabricated multichroic antenna-coupled transition edge sensor (TES) bolometer arrays for cosmic microwave background (CMB) polarimetry experiments. CMB polarimetry experiments have deployed instruments in stages. Stage II experiments deployed with O(1000) detectors and reported successful detection of B-mode (divergence-free) polarization pattern in the CMB. Stage III experiments have recently started observing with O(10,000) detectors with wider frequency coverage. A concept for a stage IV experiment, CMB-S4, is emerging to make a definitive measurement of CMB polarization from the ground with O(400,000) detectors. The orders of magnitude increase in detector count for CMB-S4 require a new approach in detector fabrication to increase fabrication throughput and reduce the cost. We report on collaborative efforts with two commercial micro-fabrication foundries to fabricate antenna-coupled TES bolometer detectors. The detector design is based on the sinuous antenna-coupled dichroic detector from the POLARBEAR-2 experiment. The TES bolometers showed the expected I-V response, and the RF performance agrees with the simulation. We will discuss the motivation, design consideration, fabrication processes, test results, and how industrial detector fabrication could be a path to fabricate hundreds of detector wafers for future CMB polarimetry experiments.

  17. Nonlocal synchronization in nearest neighbour coupled oscillators

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Elgazzar, A.S.; Cerdeira, H.A.

    2002-02-01

    We investigate a system of nearest neighbour coupled oscillators. We show that the nonlocal frequency synchronization, that might appear in such a system, occurs as a consequence of the nearest neighbour coupling. The power spectra of nonadjacent oscillators shows that there is no complete coincidence between all frequency peaks of the oscillators in the nonlocal cluster, while the peaks for neighbouring oscillators approximately coincide even if they are not yet in a cluster. It is shown that nonadjacent oscillators closer in frequencies, share slow modes with their adjacent oscillators which are neighbours in space. It is also shown that when a direct coupling between non-neighbours oscillators is introduced explicitly, the peaks of the spectra of the frequencies of those non-neighbours coincide. (author)

  18. Mechanical core coupling and reactors stability

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2006-01-01

    Structural parts of nuclear reactors are complex mechanical systems, able to vibrate with a set of proper frequencies when suitably excited. Cyclical variations in the strain state of the materials, including density perturbations, are produced. This periodic changes may affect reactor reactivity. But a variation in reactivity affects reactor thermal power, thus modifying the temperature field of the abovementiones materials. If the variation in temperature fields is fast enough, thermal-mechanical coupling may produce fast variations in strain states, and this, at its turn, modifies the reactivity, and so on. This coupling between mechanical vibrations of the structure and the materials of the core, with power oscillations of the reactor, not only may not be excluded a priori, but it seems that it has been present in some stage of the incidents or accidents that happened during the development of nuclear reactor technology. The purpose of the present communication is: (a) To review and generalize some mathematical models that were proposed in order to describe thermal-mechanical coupling in nuclear reactors. (b) To discuss some conditions in which significant instabilities could arise, including large amplitude power oscillations coupled with mechanical vibrations whose amplitudes are too small to be excluded by conventional criteria of mechanical design. Enough Certain aspects of thr physical safety of nuclear power reactors, that are objected by people that opposes to the renaissance of nucleoelectric generation, are discussed in the framework of the mathematical model proposed in this paper [es

  19. A new computerized moving stage for optical microscopes

    Science.gov (United States)

    Hatiboglu, Can Ulas; Akin, Serhat

    2004-06-01

    Measurements of microscope stage movements in the x and y directions are of importance for some stereological methods. Traditionally, the length of stage movements is measured with differing precision and accuracy using a suitable motorized stage, a microscope and software. Such equipment is generally expensive and not readily available in many laboratories. One other challenging problem is the adaptability to available microscope systems which weakens the possibility of the equipment to be used with any kind of light microscope. This paper describes a simple and cheap programmable moving stage that can be used with the available microscopes in the market. The movements of the stage are controlled by two servo-motors and a controller chip via a Java-based image processing software. With the developed motorized stage and a microscope equipped with a CCD camera, the software allows complete coverage of the specimens with minimum overlap, eliminating the optical strain associated with counting hundreds of images through an eyepiece, in a quick and precise fashion. The uses and the accuracy of the developed stage are demonstrated using thin sections obtained from a limestone core plug.

  20. CROSS-COUPLING BETWEEN ACCOMMODATION AND CONVERGENCE IS OPTIMIZED FOR A BROAD RANGE OF DIRECTIONS AND DISTANCES OF GAZE

    OpenAIRE

    Nguyen, Dorothy; Vedamurthy, Indu; Schor, Clifton

    2008-01-01

    Accommodation and convergence systems are cross-coupled so that stimulation of one system produces responses by both systems. Ideally, the cross-coupled responses of accommodation and convergence match their respective stimuli. When expressed in diopters and meter angles respectively, stimuli for accommodation and convergence are equal in the mid-sagittal plane when viewed with symmetrical convergence, where historically, the gains of the cross coupling (AC/A and CA/C ratios) have been quanti...

  1. An analysis of multislot directional coupler

    International Nuclear Information System (INIS)

    Arai, Hiroyuki; Goto, Naohisa; Yamamoto, Takumi.

    1986-03-01

    This paper presents an analysis of multislot directional coupler for monitoring the gyrotron output. We solved the boundary value problem of the directional coupler to investigate the detailed effect of finite thickness slot and mutual coupling between slots. Numerical data of coupler design is presented for non-resonant a pair slot, and mode sensitivity in overmoded waveguide is also evaluated. (author)

  2. Tunable coupling between fixed-frequency superconducting transmon qubits

    Energy Technology Data Exchange (ETDEWEB)

    Filipp, Stefan [IBM Research Zurich, 8803 Rueschlikon (Switzerland); McKay, David C.; Magesan, Easwar; Mezzacapo, Antonio; Chow, Jerry M.; Gambetta, Jay M. [IBM TJ Watson Research Center, Yorktown Heights, NY (United States)

    2016-07-01

    The controlled realization of qubit-qubit interactions is essential for both the physical implementation of quantum error-correction codes and for reliable quantum simulations. Ideally, the fidelity and speed of corresponding two-qubit gate operations is comparable to those of single qubit operations. In particular, in a scalable superconducting qubit architecture coherence must not be compromised by the presence of additional coupling elements mediating the interaction between qubits. Here we present a coupling method between fixed-frequency transmon qubits based on the frequency modulation of an auxiliary circuit coupling to the individual transmons. Since the coupler remains in its ground state at all times, its coherence does not significantly influence the fidelity of consequent entangling operations. Moreover, with the possibility to create interactions along different directions, our method is suited to engineer Hamiltonians with adjustable coupling terms. This property can be utilized for quantum simulations of spins or fermions in transmon arrays, in which pairwise couplings between adjacent qubits can be activated on demand.

  3. Advanced direct liquefaction concepts for PETC generic units. Final report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    The Advanced Concepts for Direct Coal Liquefaction program was initiated by the Department of Energy in 1991 to develop technologies that could significantly reduce the cost of producing liquid fuels by the direct liquefaction of coal. The advanced 2-stage liquefaction technology that was developed at Wilsonville over the past 10 years has contributed significantly toward decreasing the cost of producing liquids from coal to about $33/bbl. It remains, however, the objective of DOE to further reduce this cost to a level more competitive with petroleum based products. This project, among others, was initiated to investigate various alternative approaches to develop technologies that might ultimately lead to a 25 % reduction in cost of product. In this project a number of novel concepts were investigated, either individually or in a coupled configuration that had the potential to contribute toward meeting the DOE goal. The concepts included mature technologies or ones closely related to them, such as coal cleaning by oil agglomeration, fluid coking and distillate hydrotreating and dewaxing. Other approaches that were either embryonic or less developed were chemical pretreatment of coal to remove oxygen, and dispersed catalyst development for application in the 2-stage liquefaction process. This report presents the results of this project. It is arranged in four sections which were prepared by participating organizations responsible for that phase of the project. A summary of the overall project and the principal results are given in this section. First, however, an overview of the process economics and the process concepts that were developed during the course of this program is presented.

  4. Evaluation of high step-up power electronics stages in thermoelectric generator systems

    DEFF Research Database (Denmark)

    Sun, Kai; Ni, Longxian; Chen, Min

    2013-01-01

    To develop practical thermoelectric generator (TEG) systems, especially radioisotope thermoelectric power supplies for deep-space exploration, a power conditioning stage with high step-up gain is indispensable. This stage is used to step up the low output voltage of thermoelectric generators...... to the required high level. Furthermore, maximum power point tracking control for TEG modules needs to be implemented into the power electronics stages. In this paper, the temperature-dependent electrical characteristics of a thermoelectric generator are analyzed in depth. Three typical high step-up power...... converters suitable for TEG applications are discussed: an interleaved boost converter, a boost converter with a coupled inductor and an interleaved boost converter with an auxiliary transformer. A general comparison of the three high step-up converters is conducted to study the step-up gain, conversion...

  5. Hydrodynamic interaction induced spontaneous rotation of coupled active filaments.

    Science.gov (United States)

    Jiang, Huijun; Hou, Zhonghuai

    2014-12-14

    We investigate the coupled dynamics of active filaments with long range hydrodynamic interactions (HI). Remarkably, we find that filaments can rotate spontaneously under the same conditions in which a single filament alone can only move in translation. Detailed analysis reveals that the emergence of coupled rotation originates from an asymmetric flow field associated with HI which breaks the symmetry of translational motion when filaments approach. The breaking is then further stabilized by HI to form self-sustained coupled rotation. Intensive simulations show that coupled rotation forms easily when one filament tends to collide with the front-half of the other. For head-to-tail approaching, we observe another interesting HI-induced coupled motion, where filaments move together in the form of one following the other. Moreover, the radius of coupled rotation increases exponentially as the rigidity of the filament increases, which suggests that HI are also important for the alignment of rigid-rod-like filaments which has been assumed to be solely a consequence of direct collisions.

  6. Correlated Coulomb drag in capacitively coupled quantum-dot structures

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka

    2016-01-01

    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs) -- a biasdriven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach which accounts for higher-order tunneling (cotunneling......) processes as well as energy-dependent lead couplings, and identify a mesoscopic Coulomb drag mechanism driven by nonlocal multi-electron cotunneling processes. Our theory establishes the conditions for a nonzero drag as well as the direction of the drag current in terms of microscopic system parameters...... on Coulomb drag in CQD systems....

  7. Model of natural ventilation by using a coupled thermal-airflow simulation program

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2012-01-01

    This article presents a model of natural ventilation of buildings at the stage of design and a consequence of the behaviour of the occupants. An evaluation is made by coupling multizone air modelling and thermal building simulation using a deterministic set of input factors comprising among others...

  8. Observation and inverse problems in coupled cell networks

    International Nuclear Information System (INIS)

    Joly, Romain

    2012-01-01

    A coupled cell network is a model for many situations such as food webs in ecosystems, cellular metabolism and economic networks. It consists in a directed graph G, each node (or cell) representing an agent of the network and each directed arrow representing which agent acts on which. It yields a system of differential equations .x(t)=f(x(t)), where the component i of f depends only on the cells x j (t) for which the arrow j → i exists in G. In this paper, we investigate the observation problems in coupled cell networks: can one deduce the behaviour of the whole network (oscillations, stabilization, etc) by observing only one of the cells? We show that the natural observation properties hold for almost all the interactions f

  9. A Method for Coupling a Direct Current Power Source Across a Dielectric Membrane or Other Non-Conducting Membrane

    National Research Council Canada - National Science Library

    Steinbrecher, Donald H

    2008-01-01

    .... A second set of plates on the second side of the membrane form a set of coupling capacitors wherein the non-conducting dielectric membrane becomes part of the coupling-capacitor dielectric material...

  10. Fabrication of Antenna-Coupled KID Array for Cosmic Microwave Background Detection

    Science.gov (United States)

    Tang, Q. Y.; Barry, P. S.; Basu Thakur, R.; Kofman, A.; Nadolski, A.; Vieira, J.; Shirokoff, E.

    2018-05-01

    Kinetic inductance detectors (KIDs) have become an attractive alternative to traditional bolometers in the sub-mm and mm observing community due to their innate frequency multiplexing capabilities and simple lithographic processes. These advantages make KIDs a viable option for the O(500,000) detectors needed for the upcoming Cosmic Microwave Background-Stage 4 experiment. We have fabricated an antenna-coupled MKID array in the 150 GHz band optimized for CMB detection. Our design uses a twin-slot antenna coupled to an inverted microstrip made from a superconducting Nb/Al bilayer as the strip, a Nb ground plane and a SiN_x dielectric layer in between, which is then coupled to an Al KID grown on high-resistivity Si. We present the fabrication process and measurements of SiN_x microstrip resonators.

  11. Magnetotransport and coupling in nanostructured Co/Ag thin films

    International Nuclear Information System (INIS)

    Bracho Rodriguez, G.J.; Pereira, L.G.; Miranda, M.G.M.; Antunes, A.B.; Baibich, M.N.

    2000-01-01

    We have studied the electrical resistivity and giant magnetoresistance (GMR) of [Co(15 A)/Ag(45 A)] 20 /Ag(45 A) multilayers treated at different annealing temperatures. A simulation based on a formal solution of the Boltzmann equation for the electrical resistivity was performed, and the results compared to the experimental results from 4.2 to 300 K. The simulation shows that both the mean free paths and the transmission coefficients are affected by the breaking of the magnetic layers: at lower annealing temperatures, on account of stress relief and other related processes, the mean free paths increase, but the minority spin mean free path for electrons decreases for anneals above 324 deg. C. A simple parameter to measure the coupling present in spin valve systems is proposed. This shows a decrease of the coupling in the first stages of the anneals, with a sudden increase in coupling upon breaking the magnetic layers

  12. Magnetotransport and coupling in nanostructured Co/Ag thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bracho Rodriguez, G.J.; Pereira, L.G.; Miranda, M.G.M.; Antunes, A.B.; Baibich, M.N. E-mail: mbaibich@if.ufrgs.br

    2000-05-01

    We have studied the electrical resistivity and giant magnetoresistance (GMR) of [Co(15 A)/Ag(45 A)]{sub 20}/Ag(45 A) multilayers treated at different annealing temperatures. A simulation based on a formal solution of the Boltzmann equation for the electrical resistivity was performed, and the results compared to the experimental results from 4.2 to 300 K. The simulation shows that both the mean free paths and the transmission coefficients are affected by the breaking of the magnetic layers: at lower annealing temperatures, on account of stress relief and other related processes, the mean free paths increase, but the minority spin mean free path for electrons decreases for anneals above 324 deg. C. A simple parameter to measure the coupling present in spin valve systems is proposed. This shows a decrease of the coupling in the first stages of the anneals, with a sudden increase in coupling upon breaking the magnetic layers.

  13. Phase-space curvature in spin-orbit-coupled ultracold atomic systems

    Science.gov (United States)

    Armaitis, J.; Ruseckas, J.; Anisimovas, E.

    2017-04-01

    We consider a system with spin-orbit coupling and derive equations of motion which include the effects of Berry curvatures. We apply these equations to investigate the dynamics of particles with equal Rashba-Dresselhaus spin-orbit coupling in one dimension. In our derivation, the adiabatic transformation is performed first and leads to quantum Heisenberg equations of motion for momentum and position operators. These equations explicitly contain position-space, momentum-space, and phase-space Berry curvature terms. Subsequently, we perform the semiclassical approximation and obtain the semiclassical equations of motion. Taking the low-Berry-curvature limit results in equations that can be directly compared to previous results for the motion of wave packets. Finally, we show that in the semiclassical regime, the effective mass of the equal Rashba-Dresselhaus spin-orbit-coupled system can be viewed as a direct effect of the phase-space Berry curvature.

  14. InGaN directional coupler made with a one-step etching technique

    Science.gov (United States)

    Gao, Xumin; Yuan, Jialei; Yang, Yongchao; Zhang, Shuai; Shi, Zheng; Li, Xin; Wang, Yongjin

    2017-06-01

    We propose, fabricate and characterize an on-chip integration of light source, InGaN waveguide, directional coupler and photodiode, in which AlGaN layers are used as top and bottom optical claddings to form an InGaN waveguide for guiding the in-plane emitted light from the InGaN/GaN multiple-quantum-well light-emitting diode (MQW-LED). The difference in etch rate caused by different exposure windows leads to an etching depth discrepancy using the one-step etching technique, which forms the InGaN directional coupler with the overlapped underlying slab. Light propagation results directly confirm effective light coupling in the InGaN directional coupler, which is achieved through high-order guided modes. The InGaN waveguide couples the modulated light from the InGaN/GaN MQW-LED and transfers part of light to the coupled waveguide via the InGaN directional coupler. The in-plane InGaN/GaN MQW-photodiode absorbs the guided light by the coupled InGaN waveguide and induces the photocurrent. The on-chip InGaN photonic integration experimentally demonstrates an in-plane light communication with a data transmission of 50 Mbps.

  15. Dynamics of a minimal consumer network with bi-directional influence

    Science.gov (United States)

    Ekaterinchuk, Ekaterina; Jungeilges, Jochen; Ryazanova, Tatyana; Sushko, Iryna

    2018-05-01

    We study the dynamics of a model of interdependent consumer behavior defined by a family of two-dimensional noninvertible maps. This family belongs to a class of coupled logistic maps with different nonlinearity parameters and coupling terms that depend on one variable only. In our companion paper we considered the case of independent consumers as well as the case of uni-directionally connected consumers. The present paper aims at describing the dynamics in the case of a bi-directional connection. In particular, we investigate the bifurcation structure of the parameter plane associated with the strength of coupling between the consumers, focusing on the mechanisms of qualitative transformations of coexisting attractors and their basins of attraction.

  16. PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING

    International Nuclear Information System (INIS)

    LUO, Y.; PILAT, F.; ROSER, T.

    2004-01-01

    The measurement of the residual betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been developed and tested at the Relativistic Heavy Ion Collider (RHIC) as a very promising method for the linear decoupling on the ramp. By modulating the strengths of different skew quadrupole families the two eigentunes are precisely measured with the phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation directions are determined. The residual linear coupling could be corrected according to the measurement. An analytical solution for skew quadrupole modulation based on Hamiltonian perturbation approximation is given, and simulation code using smooth accelerator model is also developed. Some issues concerning the practical applications of this technique are discussed

  17. Solar constraints on new couplings between electromagnetism and gravity

    International Nuclear Information System (INIS)

    Solanki, S.K.; Preuss, O.; Haugan, M.P.; Gandorfer, A.; Povel, H.P.; Steiner, P.; Stucki, K.; Bernasconi, P.N.; Soltau, D.

    2004-01-01

    The unification of quantum field theory and general relativity is a fundamental goal of modern physics. In many cases, theoretical efforts to achieve this goal introduce auxiliary gravitational fields, ones in addition to the familiar symmetric second-rank tensor potential of general relativity, and lead to nonmetric theories because of direct couplings between these auxiliary fields and matter. Here, we consider an example of a metric-affine gauge theory of gravity in which torsion couples nonminimally to the electromagnetic field. This coupling causes a phase difference to accumulate between different polarization states of light as they propagate through the metric-affine gravitational field. Solar spectropolarimetric observations are reported and used to set strong constraints on the relevant coupling constant k: k 2 2

  18. Breaking the mold: sculpting impasses in couples' therapy.

    Science.gov (United States)

    Papp, Peggy; Scheinkman, Michele; Malpas, Jean

    2013-03-01

    In the fall of 2009, we the authors started a project at the Ackerman Institute for the Family in New York City that focuses on understanding and transforming impasses in couples' therapy. In experimenting with various interventions, we discovered the power of sculpting to capture and transform stalemates in couples relationships. In this article, we describe the ways in which sculpting brings forward the gestalt of a couple's impasse, highlights nuances of emotions and feelings, and reveals elements of both present and past. We also discuss the ways in which sculpting illuminates the partners' sense of self in the relationship as they feel constrained within their reciprocal dynamics. Through three different cases, we outline a protocol for sculpting. We demonstrate how the therapist invites the partners to create a visual/sensory narrative of their impasse, guides staging of their metaphors and images, and utilizes their enactments to unpack emotions, beliefs, and patterns that are typically on the periphery of awareness. We also articulate how sculpting offers a platform for the process of change. © FPI, Inc.

  19. Warthog: Coupling Status Update

    Energy Technology Data Exchange (ETDEWEB)

    Hart, Shane W. D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Reardon, Bradley T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-30

    stand-alone BISON run. Future work involves improving the user interface (UI), likely through integration with the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Workbench. Furthermore, automating the input creation would ease the user experience. The next priority is to continue coupling the work with other codes in the SHARP package. Efforts on other projects include work to couple the Nek5000 thermo-hydraulics code to MOOSE, but this is in the preliminary stages.

  20. Antiferromagnetic exchange coupling measurements on single Co clusters

    Science.gov (United States)

    Wernsdorfer, W.; Leroy, D.; Portemont, C.; Brenac, A.; Morel, R.; Notin, L.; Mailly, D.

    2009-03-01

    We report on single-cluster measurements of the angular dependence of the low-temperature ferromagnetic core magnetization switching field in exchange-coupled Co/CoO core-shell clusters (4 nm) using a micro-bridge DC superconducting quantum interference device (μ-SQUID). It is observed that the coupling with the antiferromagnetic shell induces modification in the switching field for clusters with intrinsic uniaxial anisotropy depending on the direction of the magnetic field applied during the cooling. Using a modified Stoner-Wohlfarth model, it is shown that the core interacts with two weakly coupled and asymmetrical antiferromagnetic sublattices. Ref.: C. Portemont, R. Morel, W. Wernsdorfer, D. Mailly, A. Brenac, and L. Notin, Phys. Rev. B 78, 144415 (2008)

  1. A flexible method to model HIV serodiscordance among couples in Mozambique.

    Directory of Open Access Journals (Sweden)

    Adelino J C Juga

    Full Text Available Whereas the number of people newly infected by HIV is continuing to decline globally, the epidemic continues to expand in many parts of the world. As the HIV/AIDS epidemic has matured in many countries, it is believed that the proportion of new infections occurring within couples has risen. Across countries, including Mozambique, a sizeable proportion of couples with HIV infection are discordant. A serodiscordant couple is a couple in which one partner has tested positive for HIV and the other has not. To describe the HIV serodiscordance among couples, a variety of association measures can be used. In this paper, we propose the serodiscordance measure (SDM as a new alternative measure. Focus is on the specification of flexible marginal and random effects models for multivariate correlated binary data together with a full-likelihood estimation method, to adequately and directly describe the measure of interest. Fitting joint models allows examining the effects of different risk factors and other covariates on the probability to be HIV positive for each member within a couple, and estimating common effects for both probabilities more efficiently, while accounting for the association between their infection status. Moreover, the interpretation of the proposed association parameter SDM is more direct and relevant and effects of covariates can be studied as well. Results show that the HIV prevalence for the province where a couple was located as well as the union number for the woman within a couple are factors associated with HIV serodiscordance. These findings are important for the Mozambican public health policy makers to design national prevention plans, which include policies to stimulate regular HIV testing for couples as well as adolescents and young adults, prior to getting married or living together as a couple.

  2. Delayed Single Stage Perineal Posterior Urethroplasty

    International Nuclear Information System (INIS)

    Ali, S.; Shahnawaz; Shahzad, I.; Baloch, M. U.

    2015-01-01

    Objective: To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Study Design: Descriptive case series. Place and Duration of Study: Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Methodology: Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Results: Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patients age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3 percentage) experienced recurrent stricture during first 10 months. Five (16.6 percentage) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6 percentage) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3 percentage with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Conclusion: Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures. (author)

  3. Electroencephalogram–Electromyography Coupling Analysis in Stroke Based on Symbolic Transfer Entropy

    Directory of Open Access Journals (Sweden)

    Yunyuan Gao

    2018-01-01

    Full Text Available The coupling strength between electroencephalogram (EEG and electromyography (EMG signals during motion control reflects the interaction between the cerebral motor cortex and muscles. Therefore, neuromuscular coupling characterization is instructive in assessing motor function. In this study, to overcome the limitation of losing the characteristics of signals in conventional time series symbolization methods, a variable scale symbolic transfer entropy (VS-STE analysis approach was proposed for corticomuscular coupling evaluation. Post-stroke patients (n = 5 and healthy volunteers (n = 7 were recruited and participated in various tasks (left and right hand gripping, elbow bending. The proposed VS-STE was employed to evaluate the corticomuscular coupling strength between the EEG signal measured from the motor cortex and EMG signal measured from the upper limb in both the time-domain and frequency-domain. Results showed a greater strength of the bi-directional (EEG-to-EMG and EMG-to-EEG VS-STE in post-stroke patients compared to healthy controls. In addition, the strongest EEG–EMG coupling strength was observed in the beta frequency band (15–35 Hz during the upper limb movement. The predefined coupling strength of EMG-to-EEG in the affected side of the patient was larger than that of EEG-to-EMG. In conclusion, the results suggested that the corticomuscular coupling is bi-directional, and the proposed VS-STE can be used to quantitatively characterize the non-linear synchronization characteristics and information interaction between the primary motor cortex and muscles.

  4. Stage-specific and age-dependent profiles of zinc, copper, manganese, and selenium in rat seminiferous tubules

    International Nuclear Information System (INIS)

    Homma-Takeda, S.; Nishimura, Y.; Watanabe, Y.; Imaseki, H.; Yukawa, M.

    2004-01-01

    Stage-specific and age-dependent profiles of zinc, copper, manganese, and selenium in testis were examined in Wistar rats by both inductively coupled argon plasma-mass spectrometry (ICP-MS) with a microdissection technique and in situ elemental imaging of micro-PIXE analysis. The young adult animals (10 weeks old) contained higher levels of zinc and manganese in the seminiferous tubules at stages VII-VIII than stages XI through VI and IX-X and the levels were higher than those of the immature and old animals. Copper and selenium levels at stages VII-VIII of the young adult animals were also higher than those of the immature and old animals. In stages VII and VIII, zinc was higher in the central area of the seminiferous epithelium, where spermatozoa were localized, demonstrating a cell-specific property. (author)

  5. Preimplantation genetic diagnosis for chromosomal rearrangements with the use of array comparative genomic hybridization at the blastocyst stage.

    Science.gov (United States)

    Christodoulou, Christodoulos; Dheedene, Annelies; Heindryckx, Björn; van Nieuwerburgh, Filip; Deforce, Dieter; De Sutter, Petra; Menten, Björn; Van den Abbeel, Etienne

    2017-01-01

    To establish the value of array comparative genomic hybridization (CGH) for preimplantation genetic diagnosis (PGD) in embryos of translocation carriers in combination with vitrification and frozen embryo transfer in nonstimulated cycles. Retrospective data analysis study. Academic centers for reproductive medicine and genetics. Thirty-four couples undergoing PGD for chromosomal rearrangements from October 2013 to December 2015. Trophectoderm biopsy at day 5 or day 6 of embryo development and subsequently whole genome amplification and array CGH were performed. This approach revealed a high occurrence of aneuploidies and structural rearrangements unrelated to the parental rearrangement. Nevertheless, we observed a benefit in pregnancy rates of these couples. We detected chromosomal abnormalities in 133/207 embryos (64.2% of successfully amplified), and 74 showed a normal microarray profile (35.7%). In 48 of the 133 abnormal embryos (36.1%), an unbalanced rearrangement originating from the parental translocation was identified. Interestingly, 34.6% of the abnormal embryos (46/133) harbored chromosome rearrangements that were not directly linked to the parental translocation in question. We also detected a combination of unbalanced parental-derived rearrangements and aneuploidies in 27 of the 133 abnormal embryos (20.3%). The use of trophectoderm biopsy at the blastocyst stage is less detrimental to the survival of the embryo and leads to a more reliable estimate of the genomic content of the embryo than cleavage-stage biopsy. In this small cohort PGD study, we describe the successful implementation of array CGH analysis of blastocysts in patients with a chromosomal rearrangement to identify euploid embryos for transfer. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Toward 100 GHz direct modulation rate of antenna coupled nanoLED

    DEFF Research Database (Denmark)

    Fortuna, Seth A.; Taghizadeh, Alireza; Yablonovitch, Eli

    2016-01-01

    We show that > 100 GHz direct modulation rate while maintaining a quantum efficiency higher than 25% is possible by using an optical antenna to enhance the spontaneous emission rate of an electrically injected III-V nanoLED.......We show that > 100 GHz direct modulation rate while maintaining a quantum efficiency higher than 25% is possible by using an optical antenna to enhance the spontaneous emission rate of an electrically injected III-V nanoLED....

  7. Staged fluidized-bed combustion and filter system

    International Nuclear Information System (INIS)

    Mei, J.S.; Halow, J.S.

    1994-01-01

    A staged fluidized-bed combustion and filter system are described for substantially reducing the quantity of waste through the complete combustion into ash-type solids and gaseous products. The device has two fluidized-bed portions, the first primarily as a combustor/pyrolyzer bed, and the second as a combustor/filter bed. The two portions each have internal baffles to define stages so that material moving therein as fluidized beds travel in an extended route through those stages. Fluidization and movement is achieved by the introduction of gases into each stage through a directional nozzle. Gases produced in the combustor/pyrolyzer bed are permitted to travel into corresponding stages of the combustor/filter bed through screen filters that permit gas flow but inhibit solids flow. Any catalyst used in the combustor/filter bed is recycled. The two beds share a common wall to minimize total volume of the system. A slightly modified embodiment can be used for hot gas desulfurization and sorbent regeneration. Either side-by-side rectangular beds or concentric beds can be used. The system is particularly suited to the processing of radioactive and chemically hazardous waste. 10 figures

  8. Anisotropic magnetocrystalline coupling of the skyrmion lattice in MnSi

    Science.gov (United States)

    Luo, Yongkang; Lin, Shi-Zeng; Fobes, D. M.; Liu, Zhiqi; Bauer, E. D.; Betts, J. B.; Migliori, A.; Thompson, J. D.; Janoschek, M.; Maiorov, B.

    2018-03-01

    We investigate the anisotropic nature of magnetocrystalline coupling between the crystallographic and skyrmion crystal (SKX) lattices in the chiral magnet MnSi by magnetic field-angle resolved resonant ultrasound spectroscopy. Abrupt changes are observed in the elastic moduli and attenuation when the magnetic field is parallel to the [011] crystallographic direction. These observations are interpreted in a phenomenological Ginzburg-Landau theory that identifies switching of the SKX orientation to be the result of an anisotropic magnetocrystalline coupling potential. Our paper sheds new light on the nature of magnetocrystalline coupling potential relevant to future spintronic applications.

  9. An RF power amplifier with inter-metal-shuffled capacitor for inter-stage matching in a digital CMOS process

    Energy Technology Data Exchange (ETDEWEB)

    Feng Xiaoxing; Zhang Xing; Ge Binjie; Wang Xin' an, E-mail: wangxa@szpku.edu.c [Key Laboratory of Integrated Microsystems, Shenzhen Graduate School of Peking University, Shenzhen 518055 (China)

    2009-06-01

    One challenge of the implementation of fully-integrated RF power amplifiers into a deep submicro digital CMOS process is that no capacitor is available, especially no high density capacitor. To address this problem, a two-stage class-AB power amplifier with inter-stage matching realized by an inter-metal coupling capacitor is designed in a 180-nm digital CMOS process. This paper compares three structures of inter-metal coupling capacitors with metal-insulator-metal (MIM) capacitor regarding their capacitor density. Detailed simulations are carried out for the leakage, the voltage dependency, the temperature dependency, and the quality factor between an inter-metal shuffled (IMS) capacitor and an MIM capacitor. Finally, an IMS capacitor is chosen to perform the inter-stage matching. The techniques are validated via the design and implement of a two-stage class-AB RF power amplifier for an UHF RFID application. The PA occupies 370 x 200 mum{sup 2} without pads in the 180-nm digital CMOS process and outputs 21.1 dBm with 40% drain efficiency and 28.1 dB power gain at 915 MHz from a single 3.3 V power supply.

  10. An RF power amplifier with inter-metal-shuffled capacitor for inter-stage matching in a digital CMOS process

    International Nuclear Information System (INIS)

    Feng Xiaoxing; Zhang Xing; Ge Binjie; Wang Xin'an

    2009-01-01

    One challenge of the implementation of fully-integrated RF power amplifiers into a deep submicro digital CMOS process is that no capacitor is available, especially no high density capacitor. To address this problem, a two-stage class-AB power amplifier with inter-stage matching realized by an inter-metal coupling capacitor is designed in a 180-nm digital CMOS process. This paper compares three structures of inter-metal coupling capacitors with metal-insulator-metal (MIM) capacitor regarding their capacitor density. Detailed simulations are carried out for the leakage, the voltage dependency, the temperature dependency, and the quality factor between an inter-metal shuffled (IMS) capacitor and an MIM capacitor. Finally, an IMS capacitor is chosen to perform the inter-stage matching. The techniques are validated via the design and implement of a two-stage class-AB RF power amplifier for an UHF RFID application. The PA occupies 370 x 200 μm 2 without pads in the 180-nm digital CMOS process and outputs 21.1 dBm with 40% drain efficiency and 28.1 dB power gain at 915 MHz from a single 3.3 V power supply.

  11. Direct coupling of a dense (supercritical) gas chromatograph to a mass spectrometer using a supersonic molecular beam interface

    International Nuclear Information System (INIS)

    Randall, L.G.; Wahrhaftig, A.L.

    1981-01-01

    A detecting mass spectrometer has been successfully coupled to a dense gas (supercritical fluid) chromatograph to produce an instrument (DGC/MS) that may be an alternative to high performance liquid chromatograph/mass spectrometer instruments (HPLC/MS) and gas chromatograph/mass spectrometer instruments (GC/MS) for analysis of involatile and/or thermally labile compounds. The mobile phase in DGC is a gas held at temperatures above the critical temperature and at pressures sufficient to obtain nearly liquid-like densities. DGC combines advantages of GC and HPLC: rapid separations, moderate operating temperatures, and analysis of involatile compounds. An advantage unique to DGC is the solvent power dependence upon pressure. While several groups have studied DGC, its development has been limited by the lack of a sensitive and selective detector. Hence, work has been directed towards the design and construction of a DGC/MS resulting in a trial instrument capable of chromatographic pressures of at least 300 atm and temperatures from 10 0 to 60 0 C. The DGC/MS coupling has been accomplished by the use of a supersonic molecular beam interface. This application of molecular beam formation appears to be unique in its requirements of a large pressure ratio (approx.10 8 ), low flow rates, and low final pressures. The authors outline characteristics of supersonic jets and molecular beams pertinent to the design of such an instrument. The interface which uses pumping speeds of 2400 and 1200 l/s in the beam forming chambers is described in detail, while the other components: the detecting mass spectrometer, the dense gas supply, and the DGC: are briefly described. Preliminary work with this instrument has established the feasibility of DGC/MS as an analytical technique and further development is recommended

  12. Application of Hoffman modulation contrast microscopy coupled with three-wavelength two-beam interferometry to the in situ direct observation of the growth process of a crystal in microgravity

    Science.gov (United States)

    Tsukamoto, Katsuo

    1988-01-01

    Direct visualization of three dimensional transfer process of both heat and mass around a growing crystal and mono-molecular growth layers on the surface is possible in situ by means of high resolution Hoffman modulation contrast microscopy coupled with three wavelength two beam Mach-Zehnder interferometry. This in situ observation is very suitable for the verification of the growth mechanism of a crystal in a solution or a melt in microgravity.

  13. Uniquely identifiable tamper-evident device using coupling between subwavelength gratings

    Science.gov (United States)

    Fievre, Ange Marie Patricia

    Reliability and sensitive information protection are critical aspects of integrated circuits. A novel technique using near-field evanescent wave coupling from two subwavelength gratings (SWGs), with the input laser source delivered through an optical fiber is presented for tamper evidence of electronic components. The first grating of the pair of coupled subwavelength gratings (CSWGs) was milled directly on the output facet of the silica fiber using focused ion beam (FIB) etching. The second grating was patterned using e-beam lithography and etched into a glass substrate using reactive ion etching (RIE). The slightest intrusion attempt would separate the CSWGs and eliminate near-field coupling between the gratings. Tampering, therefore, would become evident. Computer simulations guided the design for optimal operation of the security solution. The physical dimensions of the SWGs, i.e. period and thickness, were optimized, for a 650 nm illuminating wavelength. The optimal dimensions resulted in a 560 nm grating period for the first grating etched in the silica optical fiber and 420 nm for the second grating etched in borosilicate glass. The incident light beam had a half-width at half-maximum (HWHM) of at least 7 microm to allow discernible higher transmission orders, and a HWHM of 28 microm for minimum noise. The minimum number of individual grating lines present on the optical fiber facet was identified as 15 lines. Grating rotation due to the cylindrical geometry of the fiber resulted in a rotation of the far-field pattern, corresponding to the rotation angle of moire fringes. With the goal of later adding authentication to tamper evidence, the concept of CSWGs signature was also modeled by introducing random and planned variations in the glass grating. The fiber was placed on a stage supported by a nanomanipulator, which permitted three-dimensional displacement while maintaining the fiber tip normal to the surface of the glass substrate. A 650 nm diode laser was

  14. Disentangling Higgs-top couplings in associated production

    International Nuclear Information System (INIS)

    Ellis, John; Hwang, Dae Sung; Sakurai, Kazuki; Takeuchi, Michihisa

    2014-01-01

    In the presence of CP violation, the Higgs-top coupling may have both scalar and pseudoscalar components, κ t and κ-tilde t , which are bounded indirectly but only weakly by the present experimental constraints on the Higgs-gluon-gluon and Higgs-γ-γ couplings, whereas upper limits on electric dipole moments provide strong additional indirect constraints on κ-tilde t , if the Higgs-electron coupling is similar to that in the Standard Model and there are no cancellations with other contributions. We discuss methods to measure directly the scalar and pseudoscalar Higgs-top couplings by measurements of Higgs production in association with t-macront, single t and single t-macron at the LHC. Measurements of the total cross sections are very sensitive to variations in the Higgs-top couplings that are consistent with the present indirect constraints, as are invariant mass distributions in t-macrontH, tH and t-macronH final states. We also investigate the additional information on κ t and κ-tilde t that could be obtained from measurements of the longitudinal and transverse t polarization in the different associated production channels, and the t-macront spin correlation in t-macrontH events

  15. Rayleigh-Bénard turbulence modified by two-way coupled inertial, nonisothermal particles

    Science.gov (United States)

    Park, Hyungwon John; O'Keefe, Kevin; Richter, David H.

    2018-03-01

    Direct numerical simulation (DNS) combined with the Lagrangian point particle model is used to study Rayleigh-Bénard convection in order to understand modifications due to the interaction of inertial, nonisothermal particles with buoyancy-driven turbulence. In this system, turbulence can be altered through direct momentum coupling, as well as through buoyancy modification via thermal coupling between phases. We quantify the effect of the dispersed phase by changes to the total integrated turbulent kinetic energy (TKE) and Nusselt number (Nu). The dispersed particles experience gravitational settling and are introduced at the lower wall so that turbulence must overcome the settling velocity for the particles to vertically distribute throughout the domain. We focus primarily on particle inertia, settling velocity, mass fraction, and the ratio of the particle to fluid specific heat. Furthermore, individual contributions by the momentum coupling and thermal coupling are studied to see which most significantly changes Nu and TKE. Our results show that particles with Stokes number of order unity maximize Nu, corresponding to a peak of clustering and attenuation of TKE. Increased mass fractions lead to a linear increase of Nu and decrease of TKE. With varying specific heat ratio, Nu and TKE exhibit monotonic behaviors, where in the high limit particles become isothermal and depend upon the initialized particle temperature. It is also shown that particles two-way coupled only through momentum attenuate Nu and weaken TKE, while thermal-only coupling also weakens TKE but enhances Nu. When both couplings are present, however, thermal coupling overwhelms the momentum coupling attenuation, and the net result is an enhancement of Nu.

  16. Using invisible decay modes as probes of Z' couplings

    International Nuclear Information System (INIS)

    Hewett, J.L.; Rizzo, T.G.

    1993-08-01

    We explore the possibility that Z' couplings can be probed using decay modes which involve neutrinos once Standard Model backgrounds are directly determined by the data itself. For some models, sufficient statistics are available at either the SSC or LHC to render these modes useful for coupling determinations, provided the mass of the Z' is not much large than 1 TeV, if we assume other new physics background sources are absent

  17. Synchronization and collective motion of globally coupled Brownian particles

    International Nuclear Information System (INIS)

    Sevilla, Francisco J; Heiblum-Robles, Alexandro; Dossetti, Victor

    2014-01-01

    In this work, we study a system of passive Brownian (non-self-propelled) particles in two dimensions, interacting only through a social-like force (velocity alignment in this case) that resembles Kuramoto's coupling among phase oscillators. We show that the kinematical stationary states of the system go from a phase in thermal equilibrium with no net flux of particles, to far-from-equilibrium phases exhibiting collective motion by increasing the coupling among particles. The mechanism that leads to the instability of the equilibrium phase relies on the competition between two time scales, namely, the mean collision time of the Brownian particles in a thermal bath and the time it takes for a particle to orient its direction of motion along the direction of motion of the group. Our results show a clear connection between collective motion and the Kuramoto model for synchronization, in our case, for the direction of motion of the particles. (paper)

  18. Visible-Light-Induced Nickel-Catalyzed Negishi Cross-Couplings by Exogenous-Photosensitizer-Free Photocatalysis.

    Science.gov (United States)

    Abdiaj, Irini; Fontana, Alberto; Gomez, M Victoria; de la Hoz, Antonio; Alcázar, Jesús

    2018-03-22

    The merging of photoredox and transition-metal catalysis has become one of the most attractive approaches for carbon-carbon bond formation. Such reactions require the use of two organo-transition-metal species, one of which acts as a photosensitizer and the other one as a cross-coupling catalyst. We report herein an exogenous-photosensitizer-free photocatalytic process for the formation of carbon-carbon bonds by direct acceleration of the well-known nickel-catalyzed Negishi cross-coupling that is based on the use of two naturally abundant metals. This finding will open new avenues in cross-coupling chemistry that involve the direct visible-light absorption of organometallic catalytic complexes. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. The Second Stage of a Saturn V Ready For Test

    Science.gov (United States)

    1970-01-01

    This Saturn V S-II (second) stage is being lifted into position for a test at the Vehicle Assembly Building at the Kennedy Space Center. When the Saturn V booster stage (S-IC) burned out and dropped away, power for the Saturn was provided by the 82-foot-long and 33-foot-diameter S-II stage. Developed by the Space Division of North American Aviation under the direction of the Marshall Space Flight Center, the stage utilized five J-2 engines, each producing 200,000 pounds of thrust. The engines used liquid oxygen and liquid hydrogen as propellants. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

  20. Alternative solution algorithm for coupled thermal-hydraulic problems

    International Nuclear Information System (INIS)

    Farnsworth, D.A.; Rice, J.G.

    1986-01-01

    A thermal-hydraulic system involves flow of a fluid for which a combined solution of the continuity, momentum, and energy equations is required. When the solutions of the energy and momentum fields are dependent on each other, the system is said to be thermally coupled. A common problem encountered in the numerical solution of strongly coupled thermal-hydraulic problems is a very slow rate of convergence or a complete lack of convergence. Many times this degradation in convergence is due to the lack of true coupling between the energy and momentum fields during the iteration process. In the most widely used solution algorithms - such as the SIMPLE algorithm and its many variants - a sequential solution technique is required. That is, the solution process alternates between the flow and energy fields until a converged solution is obtained. This approach allows only implicit energy-momentum coupling. To improve the convergence rate for strongly coupled problems, a practical solution algorithm that can accommodate true energy-momentum coupling terms was developed. A complete simultaneous (versus sequential) solution of the governing conservation equations utilizing a line-by-line solution was developed and direct coupling terms between the momentum and energy fields were added utilizing a modified Newton-Raphson technique

  1. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  2. Development of an interface for directly coupled solid-phase extraction and GC-MS analysis

    NARCIS (Netherlands)

    Öllers, M.J.H.; van Lieshout, H.P.M.; Janssen, J.G.M.; Cramers, C.A.M.G.

    Solid-phase extraction (SPE) is widely used as a sample preparation technique in numerous application areas of chromatography. Large-volume injection is an attractive technique for coupling SPE to gas chromatography (GC) because it provides improved detection limits and circumvents the need for

  3. A new vibration isolation bed stage with magnetorheological dampers for ambulance vehicles

    International Nuclear Information System (INIS)

    Chae, Hee Dong; Choi, Seung-Bok

    2015-01-01

    The vibration experienced in an ambulance can lead to secondary injury to a patient and discourage a paramedic from providing emergency care. In this study, with the goal of resolving this problem, a new vibration isolation bed stage associated with magnetorheological (MR) dampers is proposed to ensure ride quality as well as better care for the patient while he/she is being transported. The bed stage proposed in this work can isolate vibrations in the vertical, rolling and pitching directions to reflect the reality that occurs in the ambulance. Firstly, an appropriate-sized MR damper is designed based on the field-dependent rheological properties of MR fluid, and the damping force characteristics of a MR damper are evaluated as a function of the current. A mechanical model of the proposed vibration isolation bed stage is then established to derive the governing equations of motion. Subsequently, a sliding mode controller is formulated to control the vibrations caused from the imposed excitation signals; those signals are directly measured using a real ambulance subjected to bump-and-curve road conditions. Using the controller based on the dynamic motion of the bed stage, the vibration control performance is evaluated in both the vertical and pitch directions. It is demonstrated that the magnitude of the vibration in the patient compartment of the ambulance can be significantly reduced by applying an input current to the MR dampers installed for the new bed stage. (technical note)

  4. Calculating luminosity for a coupled Tevatron lattice

    International Nuclear Information System (INIS)

    Holt, J.A.; Martens, M.A.; Michelotti, L.; Goderre, G.

    1995-05-01

    The traditional formula for calculating luminosity assumes an uncoupled lattice and makes use of one-degree-of-freedom lattice functions, β H and β v , for relating transverse beam widths to emittances. Strong coupling requires changing this approach. It is simplest to employ directly the linear normal form coordinates of the one turn map. An equilibrium distribution in phase space is expressed as a function of the Jacobian's eigenvectors and beam size parameters or emittances. Using the equilibrium distributions an expression for the luminosity was derived and applied to the Tevatron lattice, which was coupled due to a quadrupole roll

  5. The impact of disease stage on direct medical costs of HIV management: a review of the international literature.

    Science.gov (United States)

    Levy, Adrian; Johnston, Karissa; Annemans, Lieven; Tramarin, Andrea; Montaner, Julio

    2010-01-01

    The global prevalence of HIV infection continues to grow, as a result of increasing incidence in some countries and improved survival where highly active antiretroviral therapy (HAART) is available. Growing healthcare expenditure and shifts in the types of medical resources used have created a greater need for accurate information on the costs of treatment. The objectives of this review were to compare published estimates of direct medical costs for treating HIV and to determine the impact of disease stage on such costs, based on CD4 cell count and plasma viral load. A literature review was conducted to identify studies meeting prespecified criteria for information content, including an original estimate of the direct medical costs of treating an HIV-infected individual, stratified based on markers of disease progression. Three unpublished cost-of-care studies were also included, which were applied in the economic analyses published in this supplement. A two-step procedure was used to convert costs into a common price year (2004) using country-specific health expenditure inflators and, to account for differences in currency, using health-specific purchasing power parities to express all cost estimates in US dollars. In all nine studies meeting the eligibility criteria, infected individuals were followed longitudinally and a 'bottom-up' approach was used to estimate costs. The same patterns were observed in all studies: the lowest CD4 categories had the highest cost; there was a sharp decrease in costs as CD4 cell counts rose towards 100 cells/mm³; and there was a more gradual decline in costs as CD4 cell counts rose above 100 cells/mm³. In the single study reporting cost according to viral load, it was shown that higher plasma viral load level (> 100,000 HIV-RNA copies/mL) was associated with higher costs of care. The results demonstrate that the cost of treating HIV disease increases with disease progression, particularly at CD4 cell counts below 100 cells

  6. Antenna-coupled bolometer arrays using transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael J. [Department of Physics, University of California, Berkeley, California 94720 (United States)]. E-mail: mmyers@cosmology.berkeley.edu; Ade, Peter [School of Physics and Astronomy, Cardiff University, Cardiff, Wales (United Kingdom); Arnold, Kam [Department of Physics, University of California, Berkeley, California 94720 (United States); Engargiola, Greg [Department of Astronomy, University of California, Berkeley, California 94720 (United States); Holzapfel, Bill [Department of Physics, University of California, Berkeley, California 94720 (United States); Lee, Adrian T. [Department of Physics, University of California, Berkeley, California 94720 (United States); O' Brient, Roger [Department of Physics, University of California, Berkeley, California 94720 (United States); Richards, Paul L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Smith, Andy [Northrop Grumman, Redondo Beach, California 90278 (United States); Spieler, Helmuth [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Tran, Huan T. [Department of Physics, University of California, Berkeley, California 94720 (United States)

    2006-04-15

    We are developing antenna-coupled Transition-Edge Sensor (TES) bolometer arrays for use in measurements of the CMB polarization. TES bolometers have many well-known advantages over conventional bolometers, such as increased speed, linearity, and the existence of readout multiplexers. Antenna-coupled bolometers use an on-chip planar antenna to couple light into the bolometer. The antenna directivity and polarization sensitivity, along with the potential for on-chip band defining filters and channelizing circuits, allow a significant increase in focal plane integration. This eliminates the bulky horns, quasioptical filters, dichroics, and polarizers which might otherwise be needed in a conventional bolometric system. This simplification will ease the construction of receivers with larger numbers of pixels. We report on the fabrication and optical testing of single antenna-coupled bolometer pixels with integrated band defining filters. We will also discuss current progress on fabrication of a bolometer array based on this design.

  7. Stochastic synchronization of coupled neural networks with intermittent control

    International Nuclear Information System (INIS)

    Yang Xinsong; Cao Jinde

    2009-01-01

    In this Letter, we study the exponential stochastic synchronization problem for coupled neural networks with stochastic noise perturbations. Based on Lyapunov stability theory, inequality techniques, the properties of Weiner process, and adding different intermittent controllers, several sufficient conditions are obtained to ensure exponential stochastic synchronization of coupled neural networks with or without coupling delays under stochastic perturbations. These stochastic synchronization criteria are expressed in terms of several lower-dimensional linear matrix inequalities (LMIs) and can be easily verified. Moreover, the results of this Letter are applicable to both directed and undirected weighted networks. A numerical example and its simulations are offered to show the effectiveness of our new results.

  8. Weak and strong coupling equilibration in nonabelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, Liam [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Kurkela, Aleksi [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Faculty of Science and Technology, University of Stavanger,4036 Stavanger (Norway); Romatschke, Paul [Department of Physics, 390 UCB, University of Colorado at Boulder,Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado,Boulder, Colorado 80309 (United States); Schee, Wilke van der [Center for Theoretical Physics, MIT,Cambridge, MA 02139 (United States); Zhu, Yan [Department of Physics, University of Jyväskyla, P.O. Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics,P.O. Box 64, 00014 University of Helsinki (Finland)

    2016-04-06

    We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

  9. Weak and strong coupling equilibration in nonabelian gauge theories

    International Nuclear Information System (INIS)

    Keegan, Liam; Kurkela, Aleksi; Romatschke, Paul; Schee, Wilke van der; Zhu, Yan

    2016-01-01

    We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

  10. Reverberant acoustic energy in auditoria that comprise systems of coupled rooms

    Science.gov (United States)

    Summers, Jason E.

    2003-11-01

    A frequency-dependent model for reverberant energy in coupled rooms is developed and compared with measurements for a 1:10 scale model and for Bass Hall, Ft. Worth, TX. At high frequencies, prior statistical-acoustics models are improved by geometrical-acoustics corrections for decay within sub-rooms and for energy transfer between sub-rooms. Comparisons of computational geometrical acoustics predictions based on beam-axis tracing with scale model measurements indicate errors resulting from tail-correction assuming constant quadratic growth of reflection density. Using ray tracing in the late part corrects this error. For mid-frequencies, the models are modified to account for wave effects at coupling apertures by including power transmission coefficients. Similarly, statical-acoustics models are improved through more accurate estimates of power transmission measurements. Scale model measurements are in accord with the predicted behavior. The edge-diffraction model is adapted to study transmission through apertures. Multiple-order scattering is theoretically and experimentally shown inaccurate due to neglect of slope diffraction. At low frequencies, perturbation models qualitatively explain scale model measurements. Measurements confirm relation of coupling strength to unperturbed pressure distribution on coupling surfaces. Measurements in Bass Hall exhibit effects of the coupled stage house. High frequency predictions of statistical acoustics and geometrical acoustics models and predictions of coupling apertures all agree with measurements.

  11. Two-stage nonrecursive filter/decimator

    International Nuclear Information System (INIS)

    Yoder, J.R.; Richard, B.D.

    1980-08-01

    A two-stage digital filter/decimator has been designed and implemented to reduce the sampling rate associated with the long-term computer storage of certain digital waveforms. This report describes the design selection and implementation process and serves as documentation for the system actually installed. A filter design with finite-impulse response (nonrecursive) was chosen for implementation via direct convolution. A newly-developed system-test statistic validates the system under different computer-operating environments

  12. Amplitude death in a ring of nonidentical nonlinear oscillators with unidirectional coupling.

    Science.gov (United States)

    Ryu, Jung-Wan; Kim, Jong-Ho; Son, Woo-Sik; Hwang, Dong-Uk

    2017-08-01

    We study the collective behaviors in a ring of coupled nonidentical nonlinear oscillators with unidirectional coupling, of which natural frequencies are distributed in a random way. We find the amplitude death phenomena in the case of unidirectional couplings and discuss the differences between the cases of bidirectional and unidirectional couplings. There are three main differences; there exists neither partial amplitude death nor local clustering behavior but an oblique line structure which represents directional signal flow on the spatio-temporal patterns in the unidirectional coupling case. The unidirectional coupling has the advantage of easily obtaining global amplitude death in a ring of coupled oscillators with randomly distributed natural frequency. Finally, we explain the results using the eigenvalue analysis of the Jacobian matrix at the origin and also discuss the transition of dynamical behavior coming from connection structure as the coupling strength increases.

  13. Monlinear fish-scale metamaterial via coupled duffing oscillators

    OpenAIRE

    Kochetov, Bogdan; Tuz, Vladimir; Mladyonov, Pavel; Prosvirnin, Sergey; Kochetova, Lyudmila

    2012-01-01

    The dynamic system of two coupled Duffing oscillators is considered in order to predict the optical response of the nonlinear planar fish-scale metamaterial. The direct numerical calculation of meta material response confirms the correctness of the proposed model

  14. Constructing New Discrete Integrable Coupling System for Soliton Equation by Kronecker Product

    International Nuclear Information System (INIS)

    Yu Fajun; Zhang Hongqing

    2008-01-01

    It is shown that the Kronecker product can be applied to constructing new discrete integrable coupling system of soliton equation hierarchy in this paper. A direct application to the fractional cubic Volterra lattice spectral problem leads to a novel integrable coupling system of soliton equation hierarchy. It is also indicated that the study of discrete integrable couplings by using the Kronecker product is an efficient and straightforward method. This method can be used generally

  15. Quantifying interactions between real oscillators with information theory and phase models: Application to cardiorespiratory coupling

    Science.gov (United States)

    Zhu, Yenan; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Dick, Thomas E.; Jacono, Frank J.; Galán, Roberto F.

    2013-02-01

    Interactions between oscillators can be investigated with standard tools of time series analysis. However, these methods are insensitive to the directionality of the coupling, i.e., the asymmetry of the interactions. An elegant alternative was proposed by Rosenblum and collaborators [M. G. Rosenblum, L. Cimponeriu, A. Bezerianos, A. Patzak, and R. Mrowka, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.65.041909 65, 041909 (2002); M. G. Rosenblum and A. S. Pikovsky, Phys. Rev. EPLEEE81063-651X10.1103/PhysRevE.64.045202 64, 045202 (2001)] which consists in fitting the empirical phases to a generic model of two weakly coupled phase oscillators. This allows one to obtain the interaction functions defining the coupling and its directionality. A limitation of this approach is that a solution always exists in the least-squares sense, even in the absence of coupling. To preclude spurious results, we propose a three-step protocol: (1) Determine if a statistical dependency exists in the data by evaluating the mutual information of the phases; (2) if so, compute the interaction functions of the oscillators; and (3) validate the empirical oscillator model by comparing the joint probability of the phases obtained from simulating the model with that of the empirical phases. We apply this protocol to a model of two coupled Stuart-Landau oscillators and show that it reliably detects genuine coupling. We also apply this protocol to investigate cardiorespiratory coupling in anesthetized rats. We observe reciprocal coupling between respiration and heartbeat and that the influence of respiration on the heartbeat is generally much stronger than vice versa. In addition, we find that the vagus nerve mediates coupling in both directions.

  16. Threefold symmetric magnetic two-ion coupling in hcp rare-earth metals

    International Nuclear Information System (INIS)

    Jensen, J.

    1997-01-01

    The heavy rare earths crystallize in the hcp structure. Most of magnetic couplings between two ions in these metals are independent of the two different orientations of the hexagonal layers. However, trigonal anisotropy terms may occur, reflecting that c-axis is only threefold axis. In the presence of a trigonal coupling the symmetry is reduced, and the double-zone representation in the c-direction ceases to be valid. The strong interaction between the transverse optical phonons and the acoustic spin waves propagating in the c-direction of Yb detected more than twenty years ago, was the first example of a trigonal coupling found in these systems. A few years ago a careful neutron-diffraction study of the c-axis modulated magnetic structures in Er showed the presence of higher harmonics at positions along the c-axis translated by odd multiple of 2φ/c. This indicates distortions of the structures due to trigonal couplings, and the same characteristic phenomenon has now been also observed in Ho. Additionally, mean field calculations show that a trigonal coupling in Ho is required, in order to explain the increase in the commensurable effects observed for the 8 and 10 layered periodic structures, when a field is applied along the c-axis. (author)

  17. Capacitor blocks for linear transformer driver stages.

    Science.gov (United States)

    Kovalchuk, B M; Kharlov, A V; Kumpyak, E V; Smorudov, G V; Zherlitsyn, A A

    2014-01-01

    In the Linear Transformer Driver (LTD) technology, the low inductance energy storage components and switches are directly incorporated into the individual cavities (named stages) to generate a fast output voltage pulse, which is added along a vacuum coaxial line like in an inductive voltage adder. LTD stages with air insulation were recently developed, where air is used both as insulation in a primary side of the stages and as working gas in the LTD spark gap switches. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. The capacitor block incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Several modifications of the capacitor blocks were developed and tested on the life time and self breakdown probability. Blocks were tested both as separate units and in an assembly of capacitive module, consisting of five capacitor blocks. This paper presents detailed design of capacitor blocks, description of operation regimes, numerical simulation of electric field in the switches, and test results.

  18. Direct impact aerosol sampling by electrostatic precipitation

    Science.gov (United States)

    Braden, Jason D.; Harter, Andrew G.; Stinson, Brad J.; Sullivan, Nicholas M.

    2016-02-02

    The present disclosure provides apparatuses for collecting aerosol samples by ionizing an air sample at different degrees. An air flow is generated through a cavity in which at least one corona wire is disposed and electrically charged to form a corona therearound. At least one grounded sample collection plate is provided downstream of the at least one corona wire so that aerosol ions generated within the corona are deposited on the at least one grounded sample collection plate. A plurality of aerosol samples ionized to different degrees can be generated. The at least one corona wire may be perpendicular to the direction of the flow, or may be parallel to the direction of the flow. The apparatus can include a serial connection of a plurality of stages such that each stage is capable of generating at least one aerosol sample, and the air flow passes through the plurality of stages serially.

  19. Process-independent strong running coupling

    International Nuclear Information System (INIS)

    Binosi, Daniele; Mezrag, Cedric; Papavassiliou, Joannis; Roberts, Craig D.; Rodriguez-Quintero, Jose

    2017-01-01

    Here, we unify two widely different approaches to understanding the infrared behavior of quantum chromodynamics (QCD), one essentially phenomenological, based on data, and the other computational, realized via quantum field equations in the continuum theory. Using the latter, we explain and calculate a process-independent running-coupling for QCD, a new type of effective charge that is an analogue of the Gell-Mann–Low effective coupling in quantum electrodynamics. The result is almost identical to the process-dependent effective charge defined via the Bjorken sum rule, which provides one of the most basic constraints on our knowledge of nucleon spin structure. As a result, this reveals the Bjorken sum to be a near direct means by which to gain empirical insight into QCD's Gell-Mann–Low effective charge.

  20. Silicon nanostructures produced by laser direct etching

    DEFF Research Database (Denmark)

    Müllenborn, Matthias; Dirac, Paul Andreas Holger; Petersen, Jon Wulff

    1995-01-01

    A laser direct-write process has been applied to structure silicon on a nanometer scale. In this process, a silicon substrate, placed in a chlorine ambience, is locally heated above its melting point by a continuous-wave laser and translated by high-resolution direct-current motor stages. Only...

  1. A Two-stage DC-DC Converter for the Fuel Cell-Supercapacitor Hybrid System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    A wide input range multi-stage converter is proposed with the fuel cells and supercapacitors as a hybrid system. The front-end two-phase boost converter is used to optimize the output power and to reduce the current ripple of fuel cells. The supercapacitor power module is connected by push...... and designed. A 1kW prototype controlled by TMS320F2808 DSP is built in the lab. Simulation and experimental results confirm the feasibility of the proposed two stage dc-dc converter system.......-pull-forward half bridge (PPFHB) converter with coupled inductors in the second stage to handle the slow transient response of the fuel cells and realize the bidirectional power flow control. Moreover, this cascaded structure simplifies the power management. The control strategy for the whole system is analyzed...

  2. Applying artificial intelligence to disease staging: Deep learning for improved staging of diabetic retinopathy.

    Science.gov (United States)

    Takahashi, Hidenori; Tampo, Hironobu; Arai, Yusuke; Inoue, Yuji; Kawashima, Hidetoshi

    2017-01-01

    Disease staging involves the assessment of disease severity or progression and is used for treatment selection. In diabetic retinopathy, disease staging using a wide area is more desirable than that using a limited area. We investigated if deep learning artificial intelligence (AI) could be used to grade diabetic retinopathy and determine treatment and prognosis. The retrospective study analyzed 9,939 posterior pole photographs of 2,740 patients with diabetes. Nonmydriatic 45° field color fundus photographs were taken of four fields in each eye annually at Jichi Medical University between May 2011 and June 2015. A modified fully randomly initialized GoogLeNet deep learning neural network was trained on 95% of the photographs using manual modified Davis grading of three additional adjacent photographs. We graded 4,709 of the 9,939 posterior pole fundus photographs using real prognoses. In addition, 95% of the photographs were learned by the modified GoogLeNet. Main outcome measures were prevalence and bias-adjusted Fleiss' kappa (PABAK) of AI staging of the remaining 5% of the photographs. The PABAK to modified Davis grading was 0.64 (accuracy, 81%; correct answer in 402 of 496 photographs). The PABAK to real prognosis grading was 0.37 (accuracy, 96%). We propose a novel AI disease-staging system for grading diabetic retinopathy that involves a retinal area not typically visualized on fundoscopy and another AI that directly suggests treatments and determines prognoses.

  3. Correlation effects in side-coupled quantum dots

    International Nuclear Information System (INIS)

    Zitko, R; Bonca, J

    2007-01-01

    Using Wilson's numerical renormalization group (NRG) technique, we compute zero-bias conductance and various correlation functions of a double quantum dot (DQD) system. We present different regimes within a phase diagram of the DQD system. By introducing a negative Hubbard U on one of the quantum dots, we simulate the effect of electron-phonon coupling and explore the properties of the coexisting spin and charge Kondo state. In a triple quantum dot (TQD) system, a multi-stage Kondo effect appears where localized moments on quantum dots are screened successively at exponentially distinct Kondo temperatures

  4. A hybrid, coupled approach for modeling charged fluids from the nano to the mesoscale

    Science.gov (United States)

    Cheung, James; Frischknecht, Amalie L.; Perego, Mauro; Bochev, Pavel

    2017-11-01

    We develop and demonstrate a new, hybrid simulation approach for charged fluids, which combines the accuracy of the nonlocal, classical density functional theory (cDFT) with the efficiency of the Poisson-Nernst-Planck (PNP) equations. The approach is motivated by the fact that the more accurate description of the physics in the cDFT model is required only near the charged surfaces, while away from these regions the PNP equations provide an acceptable representation of the ionic system. We formulate the hybrid approach in two stages. The first stage defines a coupled hybrid model in which the PNP and cDFT equations act independently on two overlapping domains, subject to suitable interface coupling conditions. At the second stage we apply the principles of the alternating Schwarz method to the hybrid model by using the interface conditions to define the appropriate boundary conditions and volume constraints exchanged between the PNP and the cDFT subdomains. Numerical examples with two representative examples of ionic systems demonstrate the numerical properties of the method and its potential to reduce the computational cost of a full cDFT calculation, while retaining the accuracy of the latter near the charged surfaces.

  5. A multi-stage malaria vaccine candidate targeting both transmission and asexual parasite life-cycle stages

    DEFF Research Database (Denmark)

    Theisen, Michael; Roeffen, Will; Singh, Susheel K

    2014-01-01

    that combine antigens from both stages may provide direct protection and indirect benefit by reducing the force of infection. We constructed a chimeric antigen composed of a fragment of the Plasmodium falciparum (Pf) glutamate-rich protein fused in frame to a correctly folded fragment of Pfs48/45. The chimera...... dependent cellular inhibition assay. The combined data provide a strong rationale for entering the next phase of clinical grade production and testing....

  6. Review of multi-physics temporal coupling methods for analysis of nuclear reactors

    International Nuclear Information System (INIS)

    Zerkak, Omar; Kozlowski, Tomasz; Gajev, Ivan

    2015-01-01

    Highlights: • Review of the numerical methods used for the multi-physics temporal coupling. • Review of high-order improvements to the Operator Splitting coupling method. • Analysis of truncation error due to the temporal coupling. • Recommendations on best-practice approaches for multi-physics temporal coupling. - Abstract: The advanced numerical simulation of a realistic physical system typically involves multi-physics problem. For example, analysis of a LWR core involves the intricate simulation of neutron production and transport, heat transfer throughout the structures of the system and the flowing, possibly two-phase, coolant. Such analysis involves the dynamic coupling of multiple simulation codes, each one devoted to the solving of one of the coupled physics. Multiple temporal coupling methods exist, yet the accuracy of such coupling is generally driven by the least accurate numerical scheme. The goal of this paper is to review in detail the approaches and numerical methods that can be used for the multi-physics temporal coupling, including a comprehensive discussion of the issues associated with the temporal coupling, and define approaches that can be used to perform multi-physics analysis. The paper is not limited to any particular multi-physics process or situation, but is intended to provide a generic description of multi-physics temporal coupling schemes for any development stage of the individual (single-physics) tools and methods. This includes a wide spectrum of situation, where the individual (single-physics) solvers are based on pre-existing computation codes embedded as individual components, or a new development where the temporal coupling can be developed and implemented as a part of code development. The discussed coupling methods are demonstrated in the framework of LWR core analysis

  7. Transverse emittance growth in staged laser-wakefield acceleration

    Directory of Open Access Journals (Sweden)

    T. Mehrling

    2012-11-01

    Full Text Available We present a study on the emittance evolution of electron bunches, externally injected into laser-driven plasma waves using the three-dimensional particle-in-cell (PIC code OSIRIS. Results show order-of-magnitude transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This behavior is supported by analytic theory reproducing the simulation data to a percent level. The length over which the full emittance growth develops is found to be less than or comparable to the typical dimension of a single plasma module in current multistage designs. In addition, the analytic theory enables the quantitative prediction of emittance degradation in two consecutive accelerators coupled by free-drift sections, excluding this as a scheme for effective emittance-growth suppression, and thus suggests the necessity of beam-matching sections between acceleration stages with fundamental implications on the overall design of staged laser-wakefield accelerators.

  8. Design and construction of the X-2 two-stage free piston driven expansion tube

    Science.gov (United States)

    Doolan, Con

    1995-01-01

    This report outlines the design and construction of the X-2 two-stage free piston driven expansion tube. The project has completed its construction phase and the facility has been installed in the new impulsive research laboratory where commissioning is about to take place. The X-2 uses a unique, two-stage driver design which allows a more compact and lower overall cost free piston compressor. The new facility has been constructed in order to examine the performance envelope of the two-stage driver and how well it couple to sub-orbital and super-orbital expansion tubes. Data obtained from these experiments will be used for the design of a much larger facility, X-3, utilizing the same free piston driver concept.

  9. Chimera states in nonlocally coupled phase oscillators with biharmonic interaction

    Science.gov (United States)

    Cheng, Hongyan; Dai, Qionglin; Wu, Nianping; Feng, Yuee; Li, Haihong; Yang, Junzhong

    2018-03-01

    Chimera states, which consist of coexisting domains of coherent and incoherent parts, have been observed in a variety of systems. Most of previous works on chimera states have taken into account specific form of interaction between oscillators, for example, sinusoidal coupling or diffusive coupling. Here, we investigate chimera dynamics in nonlocally coupled phase oscillators with biharmonic interaction. We find novel chimera states with features such as that oscillators in the same coherent cluster may split into two groups with a phase difference around π/2 and that oscillators in adjacent coherent clusters may have a phase difference close to π/2. The different impacts of the coupling ranges in the first and the second harmonic interactions on chimera dynamics are investigated based on the synchronous dynamics in globally coupled phase oscillators. Our study suggests a new direction in the field of chimera dynamics.

  10. Wind farm node connected DFIG/back-to-back converter coupling transient model for grid integration studies

    International Nuclear Information System (INIS)

    Ostolaza, J.X.; Etxeberria, A.; Zubia, I.

    2015-01-01

    Highlights: • Full-order DFIG/B2B coupling transient model to the connection of wind farm node. • Algebraic loop between stator and filter currents due to transformer is overcome. • A novel decoupling based control design of grid-side converter is presented. • 24 state-variables describe the DFIG: 15 electro-mechanical, plus 9 for control. • State machine implements the sequential control among its operational modes. - Abstract: This paper presents the explicit electromagnetic transient model of a Doubly Fed Induction Generator (DFIG), that includes its coupling with the back-to-back converter, when the generator/converter set is connected to the wind farm’s Thevenin equivalent, as seen from DFIG’s terminals. Besides that, DFIG’s grid side converter control system is defined in detail, so that expressions for the direct tuning of all compensators are provided. The overall electromechanical wind generator model includes 24 state variables: four mechanical, eleven electrical, and nine more – one for each controller – associated to the control system. The developed model is complemented with a state machine that implements the sequential control among the different stages that define its operational modes. Simulation and experimental results show that the developed model is able to predict the behaviour of the generator in short and long term scenarios.

  11. Munc18-1-regulated stage-wise SNARE assembly underlying synaptic exocytosis.

    Science.gov (United States)

    Ma, Lu; Rebane, Aleksander A; Yang, Guangcan; Xi, Zhiqun; Kang, Yuhao; Gao, Ying; Zhang, Yongli

    2015-12-23

    Synaptic-soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins couple their stage-wise folding/assembly to rapid exocytosis of neurotransmitters in a Munc18-1-dependent manner. The functions of the different assembly stages in exocytosis and the role of Munc18-1 in SNARE assembly are not well understood. Using optical tweezers, we observed four distinct stages of assembly in SNARE N-terminal, middle, C-terminal, and linker domains (or NTD, MD, CTD, and LD, respectively). We found that SNARE layer mutations differentially affect SNARE assembly. Comparison of their effects on SNARE assembly and on exocytosis reveals that NTD and CTD are responsible for vesicle docking and fusion, respectively, whereas MD regulates SNARE assembly and fusion. Munc18-1 initiates SNARE assembly and structures t-SNARE C-terminus independent of syntaxin N-terminal regulatory domain (NRD) and stabilizes the half-zippered SNARE complex dependent upon the NRD. Our observations demonstrate distinct functions of SNARE domains whose assembly is intimately chaperoned by Munc18-1.

  12. The staging area concept for item control

    International Nuclear Information System (INIS)

    Williams, R.A.

    1984-01-01

    Accounting for special nuclear material contained in fabricated nuclear fuel rod items has been completely automated at the Westinghouse Nuclear Fuel Division facility in Columbia, South Carolina. Experience with the automated system has shown substantial difficulty in maintaining current knowledge of the precise locations of rods pulled out of the ''normal'' processing cycle. This has been resolved by creation of two tightly controlled staging areas for handling and distribution of all ''deviant'' rods by two specially trained expeditors. Thus, coupling automated data collection with centralized expert handling and distribution has created a viable system for control of large numbers of fuel rods in a major fabrication plant

  13. Direct contact condensation in packed beds

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Klausner, James F.; Mei, Renwei; Knight, Jessica [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FL 32611 (United States)

    2006-12-15

    A diffusion driven desalination process was recently described where a very effective direct contact condenser with a packed bed is used to condense water vapor out of an air/vapor mixture. A laboratory scale direct contact condenser has been fabricated as a twin tower structure with two stages, co-current and countercurrent. Experiments have been operated in each stage with respective saturated air inlet temperatures of 36, 40 and 43{sup o}C. The temperature and humidity data have been collected at the inlet and exit of the packed bed for different water to air mass flow ratios that vary between 0 and 2.5. A one-dimensional model based on conservation principles has been developed, which predicts the variation of temperature, humidity, and condensation rate through the condenser stages. Agreement between the model and experiments is very good. It is observed that the countercurrent flow stage condensation effectiveness is significantly higher than that for the co-current stage. The condensation heat and mass transfer rates were found to decrease when water blockages occur within the packed bed. Using high-speed digital cinematography, it was observed that this problem can occur at any operating condition, and is dependent on the packing surface wetting characteristics. This observation is used to explain the requirement for two different empirical constants, depending on packing diameter, suggested by Onda for the air side mass transfer coefficient correlation. (author)

  14. Traffic dynamics on coupled spatial networks

    International Nuclear Information System (INIS)

    Du, Wen-Bo; Zhou, Xing-Lian; Chen, Zhen; Cai, Kai-Quan; Cao, Xian-Bin

    2014-01-01

    With the rapid development of modern traffic, various means of transportation systems make it more convenient and diversified for passengers to travel out. In this paper, we establish a two-layered spatial network model where the low-speed lower layer is a regular lattice and the high-speed upper layer is a scale-free network embedded in the lattice. Passengers will travel along the path with the minimal travel time, and they can transfer from one layer to the other, which will induce extra transfer cost. We extensively investigate the traffic process on these coupled spatial networks and focus on the effect of the parameter α, the speed ratio between two networks. It is found that, as α grows, the network capacity of the coupled networks increases in the early stage and then decreases, indicating that cooperation between the coupled networks will induce the highest network capacity at an optimal α. We then provide an explanation for this non-monotonous dependence from a micro-scope point of view. The travel time reliability is also examined. Both in free-flow state and congestion state, the travel time is linearly related to the Euclidean distance. However, the variance of travel time in the congestion state is remarkably larger than that in the free-flow state, namely, people have to set aside more redundant time in an unreliable traffic system

  15. Contemporary management of stage I and II seminoma.

    Science.gov (United States)

    Chung, Peter; Warde, Padraig

    2013-10-01

    Seminoma represents about 60 % of all testicular germ cell tumors. At presentation about 80 % of patients have stage I and about 15 % have stage II disease. The last three decades have seen a substantial change in the philosophy of management with the success of surveillance as a strategy to minimize unnecessary treatment, recognition of the late effects of radiation therapy, and the success of cisplatin-based chemotherapy as curative treatment either in the first-line or salvage setting. Overall, in stage I disease where 80-85 % are cured with orchiectomy alone, efforts now are directed at reducing the burden of the disease and its diagnosis on patients with increasing utilization of surveillance and decreased employment of adjuvant therapy. For stage II disease, balancing the relative toxicities of radiation and chemotherapy while avoiding the use of multimodality therapy due to the additive long-term toxicity has become the priority.

  16. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-02

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

  17. Three-stage method for interpretation of uranium-lead isotopic data

    International Nuclear Information System (INIS)

    Nejmark, L.A.; Ovchinnikova, G.V.; Levchenkov, O.A.

    1982-01-01

    Three-dimensional approach for the iterpretation of uranium-lead isoto e ratios in pnatural systems, development of which corresponds to three stages, has been considered. In the framework of the three-stage model two cases, differing in the character of uranium-lead systems violation at the beginning of the third stage, are discussed. The first case corresponds to uranium addition or lead substraction, and the second one - to addition of lead of unknown isotopic content. Three-stage approach permits without amending the isotopic content of lead captured during crystallization to calculated the beginning of the second and third stages of uranium-lead systems development and to evaluate parameters of lead added to the system. Concrete examples of interpretation of uranium-lead isotopic ratios in minerals and rock samples as a whole both of the terrestrial and cosmic origin are considered. Possibilities and limitations of the three-stage approach are analyzed and directions of further development are outlined

  18. Seeking Ligand Bias: Assessing GPCR Coupling to Beta-Arrestins for Drug Discovery

    OpenAIRE

    Bohn, Laura M.; McDonald, Patricia H.

    2010-01-01

    G protein-coupled receptors (GPCR) are the major site of action for endogenous hormones and neurotransmitters. Early drug discovery efforts focused on determining whether ligands could engage G protein coupling and subsequently activate or inhibit cognate “second messengers.” Gone are those simple days as we now realize that receptors can also couple βarrestins. As we delve into the complexity of ligand-directed signaling and receptosome scaffolds, we are faced with what may seem like endless...

  19. Bidirectional waveguide coupling with plasmonic Fano nanoantennas

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Rui; Decker, Manuel, E-mail: manuel.decker@anu.edu.au; Staude, Isabelle; Neshev, Dragomir N.; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

    2014-08-04

    We introduce the concept of a bidirectional, compact single-element Fano nanoantenna that allows for directional coupling of light in opposite directions of a high-index dielectric waveguide for two different operation wavelengths. We utilize a Fano resonance to tailor the radiation phases of a gold nanodisk and a nanoslit that is inscribed into the nanodisk to realize bidirectional scattering. We show that this Fano nanoantenna operates as a bidirectional waveguide coupler at telecommunication wavelengths and, thus, is ideally suitable for integrated wavelength-selective light demultiplexing.

  20. Microbiota dynamics and diversity at different stages of industrial processing of cocoa beans into cocoa powder

    NARCIS (Netherlands)

    Líma, L.J.R.; Velpen, van der V.; Wolkers-Rooijackers, J.C.M.; Kamphuis, H.J.; Zwietering, M.H.; Nout, M.J.R.

    2012-01-01

    We sampled a cocoa powder production line to investigate the impact of processing on the microbial community size and diversity at different stages. Classical microbiological methods were combined with 16S rRNA gene PCR-denaturing gradient gel electrophoresis, coupled with clone library