H.264 SVC Complexity Reduction Based on Likelihood Mode Decision

Directory of Open Access Journals (Sweden)

L. Balaji

2015-01-01

Full Text Available H.264 Advanced Video Coding (AVC was prolonged to Scalable Video Coding (SVC. SVC executes in different electronics gadgets such as personal computer, HDTV, SDTV, IPTV, and full-HDTV in which user demands various scaling of the same content. The various scaling is resolution, frame rate, quality, heterogeneous networks, bandwidth, and so forth. Scaling consumes more encoding time and computational complexity during mode selection. In this paper, to reduce encoding time and computational complexity, a fast mode decision algorithm based on likelihood mode decision (LMD is proposed. LMD is evaluated in both temporal and spatial scaling. From the results, we conclude that LMD performs well, when compared to the previous fast mode decision algorithms. The comparison parameters are time, PSNR, and bit rate. LMD achieve time saving of 66.65% with 0.05% detriment in PSNR and 0.17% increment in bit rate compared with the full search method.

Common mode noise on the main Tevatron bus and associated beam emittance growth

International Nuclear Information System (INIS)

Zhang, P.; Johnson, R.P.; Kuchnir, M.; Siergiej, D.; Wolff, D.

1991-05-01

Overlap of betatron tune frequencies with the power supply noise spectrum can cause transverse beam emittance growth in a storage ring. We have studied this effect for tunes near the integer, where the betatron frequency is low. By injecting noise onto the main power supply bus, it was determined that common mode noise was the dominant source of emittance growth. A noise suppression feed-back loop was then used to reduce the noise and the emittance growth. These experiments are described as are investigations of the common mode propagation along the Tevatron bus and measurements of the fields generated by common mode excitation of isolated Tevatron magnets. 3 refs., 4 figs

Temperature-Driven Change in the Unstable Growth Mode on Patterned GaAs(001)

International Nuclear Information System (INIS)

Tadayyon-Eslami, T.; Phaneuf, R. J.; Kan, H.-C.; Calhoun, L. C.

2006-01-01

We observe a dramatic change in the unstable growth mode during GaAs molecular beam epitaxy on patterned GaAs(001) as the temperature is lowered through approximately 540 deg. C, roughly coincident with the preroughening temperature. Observations of the As 2 flux dependence, however, rule out thermodynamic preroughening as driving the growth mode change. Similar observations rule out the change in surface reconstruction as the cause. Instead, we find evidence that the change in the unstable growth mode can be explained by a competition between the decreased adatom collection rate on small terraces and a small anisotropic barrier to adatom diffusion downward across step bunches

Fatigue crack growth in fiber reinforced plastics

Science.gov (United States)

Mandell, J. F.

1979-01-01

Fatigue crack growth in fiber composites occurs by such complex modes as to frustrate efforts at developing comprehensive theories and models. Under certain loading conditions and with certain types of reinforcement, simpler modes of fatigue crack growth are observed. These modes are more amenable to modeling efforts, and the fatigue crack growth rate can be predicted in some cases. Thus, a formula for prediction of ligamented mode fatigue crack growth rate is available.

Equalizer complexity of mode division multiplexed coherent receivers

NARCIS (Netherlands)

Inan, B.; Spinnler, B.; Ferreira, F.; Lobato, A.; Adhikari, S.; Sleiffer, V.A.J.M.; Borne, van den D.; Hanik, N.; Jansen, S.L.

2012-01-01

We show that OFDM requires the lowest equalizer complexity for crosstalk compensation in a mode-division-multiplexing receiver. For a 2000-km transmission distance and less than 10% ODFM-specific overhead, the modal dispersion must be below 12 ps/km

Fatigue Debond Growth in Sandwich Structures Loaded in Mixed Mode Bending (MMB)

DEFF Research Database (Denmark)

Quispitupa, Amilcar; Berggreen, Christian; Carlsson, Leif A.

2008-01-01

Static and cyclic debond growth in sandwich specimens loaded in mixed mode bending (MMB) is examined. The MMB sandwich specimens were manufactured using H100 PVC foam core and E-glass/polyester non-crimp quadro-axial [0/45/90/-45]s DBLT-850 face sheets. Static test were performed to determine...... the fracture toughness of the debonded sandwich specimens at different mixed mode loadings. The mixed mode ratio (mode I to mode II) was controlled by changing the lever arm distance of the MMB test rig. Compliance technique and visual inspection was employed to measure the crack length during fatigue. Fatigue...... tests were performed at 90% of the static fracture toughness at a loading ratio of R=0.1. Fatigue results revealed higher debond crack growth rates when the lever arm distance was increased. For some specimens, the crack propagated just below the face/core interface in the foam core and for others...

Experimental and theoretical studies of active control of resistive wall mode growth in the EXTRAP T2R reversed-field pinch

Science.gov (United States)

Drake, J. R.; Brunsell, P. R.; Yadikin, D.; Cecconello, M.; Malmberg, J. A.; Gregoratto, D.; Paccagnella, R.; Bolzonella, T.; Manduchi, G.; Marrelli, L.; Ortolani, S.; Spizzo, G.; Zanca, P.; Bondeson, A.; Liu, Y. Q.

2005-07-01

Active feedback control of resistive wall modes (RWMs) has been demonstrated in the EXTRAP T2R reversed-field pinch experiment. The control system includes a sensor consisting of an array of magnetic coils (measuring mode harmonics) and an actuator consisting of a saddle coil array (producing control harmonics). Closed-loop (feedback) experiments using a digital controller based on a real time Fourier transform of sensor data have been studied for cases where the feedback gain was constant and real for all harmonics (corresponding to an intelligent-shell) and cases where the feedback gain could be set for selected harmonics, with both real and complex values (targeted harmonics). The growth of the dominant RWMs can be reduced by feedback for both the intelligent-shell and targeted-harmonic control systems. Because the number of toroidal positions of the saddle coils in the array is half the number of the sensors, it is predicted and observed experimentally that the control harmonic spectrum has sidebands. Individual unstable harmonics can be controlled with real gains. However if there are two unstable mode harmonics coupled by the sideband effect, control is much less effective with real gains. According to the theory, complex gains give better results for (slowly) rotating RWMs, and experiments support this prediction. In addition, open loop experiments have been used to observe the effects of resonant field errors applied to unstable, marginally stable and robustly stable modes. The observed effects of field errors are consistent with the thin-wall model, where mode growth is proportional to the resonant field error amplitude and the wall penetration time for that mode harmonic.

Experimental and theoretical studies of active control of resistive wall mode growth in the EXTRAP T2R reversed-field pinch

International Nuclear Information System (INIS)

Drake, J.R.; Brunsell, P.R.; Yadikin, D.

2005-01-01

Active feedback control of resistive wall modes (RWMs) has been demonstrated in the EXTRAP T2R reversed-field pinch experiment. The control system includes a sensor consisting of an array of magnetic coils (measuring mode harmonics) and an actuator consisting of a saddle coil array (producing control harmonics). Closed-loop (feedback) experiments using a digital controller based on a real time Fourier transform of sensor data have been studied for cases where the feedback gain was constant and real for all harmonics (corresponding to an intelligent-shell) and cases where the feedback gain could be set for selected harmonics, with both real and complex values (targeted harmonics). The growth of the dominant RWMs can be reduced by feedback for both the intelligent-shell and targeted-harmonic control systems. Because the number of toroidal positions of the saddle coils in the array is half the number of the sensors, it is predicted and observed experimentally that the control harmonic spectrum has sidebands. Individual unstable harmonics can be controlled with real gains. However if there are two unstable mode harmonics coupled by the sideband effect, control is much less effective with real gains. According to the theory, complex gains give better results for (slowly) rotating RWMs, and experiments support this prediction. In addition, open loop experiments have been used to observe the effects of resonant field errors applied to unstable, marginally stable and robustly stable modes. The observed effects of field errors are consistent with the thin-wall model, where mode growth is proportional to the resonant field error amplitude and the wall penetration time for that mode harmonic

Complexity control algorithm based on adaptive mode selection for interframe coding in high efficiency video coding

Science.gov (United States)

Chen, Gang; Yang, Bing; Zhang, Xiaoyun; Gao, Zhiyong

2017-07-01

The latest high efficiency video coding (HEVC) standard significantly increases the encoding complexity for improving its coding efficiency. Due to the limited computational capability of handheld devices, complexity constrained video coding has drawn great attention in recent years. A complexity control algorithm based on adaptive mode selection is proposed for interframe coding in HEVC. Considering the direct proportionality between encoding time and computational complexity, the computational complexity is measured in terms of encoding time. First, complexity is mapped to a target in terms of prediction modes. Then, an adaptive mode selection algorithm is proposed for the mode decision process. Specifically, the optimal mode combination scheme that is chosen through offline statistics is developed at low complexity. If the complexity budget has not been used up, an adaptive mode sorting method is employed to further improve coding efficiency. The experimental results show that the proposed algorithm achieves a very large complexity control range (as low as 10%) for the HEVC encoder while maintaining good rate-distortion performance. For the lowdelayP condition, compared with the direct resource allocation method and the state-of-the-art method, an average gain of 0.63 and 0.17 dB in BDPSNR is observed for 18 sequences when the target complexity is around 40%.

Electrostatic effect for the collisionless tearing mode

International Nuclear Information System (INIS)

Hoshino, M.

1987-01-01

Electron dynamics has not been self-consistently considered in collisionless tearing mode theories to date because of the mathematical complexity of the Vlasov-Maxwell equations. We have found using computer simulations that electrostatic fields play an important role in the tearing mode. Vlasov theory, including the electrostatic field, is investigated for topologies with both antiparallel and nonantiparallel magnetic field lines. The electrostatic field influences the resonant current in the neutral sheet which is a non-MHD effect, and modifies the linear growth rate. At the magnetopause, where the field lines are not antiparallel, the electrostatic effect acts to raise the linear growth rate of the tearing mode. On the other hand, in the magnetotail, where magnetic field lines are antiparallel, the electrostatic effect reduces the tearing mode growth rate. copyright American Geophysical Union 1987

Mode I and Mode II Interlaminar Crack Growth Resistances of Ceramic Matrix Composites at Ambient Temperature

National Research Council Canada - National Science Library

Choi, Sung R; Kowalik, Robert W; Alexander, Donald J

2007-01-01

...) including three gas-turbine grade melt-infiltrated SiC/SiC composites. Modes I and II crack growth resistances, GI and GII, were evaluated at ambient temperature using double cantilever beam and end notched flexure methods, respectively...

Curvature effects in the nonlinear growth of the cylindrical tearing mode

International Nuclear Information System (INIS)

Somon, J. P.

1984-01-01

The full set of the usual resistive massless equations is used to investigate the nonlinear growth of the helical perturbation to a cylindrical equilibrium with tokamak ordering. There is a curvature dependant critical magnetic island width xsub(T)sup(*) α set containing D/Δ' above which the Rutherford solution is recovered for the tearing mode as well as for the linear slow interchange modes with Δ' > 0. Non linearity stabilizes at this critical width the linearly unstable slow interchange modes with Δ' > 0

Friction stress effects on mode I crack growth predictions

NARCIS (Netherlands)

Chen, Q.; Deshpande, V.S.; Giessen, E. van der; Needleman, A.

2003-01-01

The effect of a lattice friction stress on the monotonic growth of a plane strain mode I crack under small-scale yielding conditions is analyzed using discrete dislocation plasticity. When the friction stress is increased from zero to half the dislocation nucleation stress, the crack tip stress

Influence of Different Interlayers on Growth Mode and Properties of InN by MOVPE

International Nuclear Information System (INIS)

Ri-Qing, Zhang; Xiang-Lin, Liu; Ting-Ting, Kang; Wei-Guo, Hu; Shao-Yan, Yang; Chun-Mei, Jiao; Qing-Sheng, Zhu

2008-01-01

We grow InN epilayers on different interlayers by metal organic vapour phase epitaxy (MOVPE) method, and investigate the effect of interlayer on the properties and growth mode of InN films. Three InN samples were deposited on nitrided sapphire, low-temperature InN (LT-InN) and high-temperature GaN (HT-GaN), respectively. The InN layer grown directly on nitrided sapphire owns the narrowest x-ray diffraction rocking curve (XRC) width of 300 arcsec among the three samples, and demonstrates a two-dimensional (2D) step-flow-like lateral growth mode, which is much different from the three-dimensional (3D) pillar-like growth mode of LT-InN and HT-GaN buffered samples. It seems that mismatch tensile strain is helpful for the lateral epitaxy of InN film, whereas compressive strain promotes the vertical growth of InN films

Different modes of APC/C activation control growth and neuron-glia interaction in the developing Drosophila eye.

Science.gov (United States)

Neuert, Helen; Yuva-Aydemir, Yeliz; Silies, Marion; Klämbt, Christian

2017-12-15

The development of the nervous system requires tight control of cell division, fate specification and migration. The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that affects different steps of cell cycle progression, as well as having postmitotic functions in nervous system development. It can therefore link different developmental stages in one tissue. The two adaptor proteins, Fizzy/Cdc20 and Fizzy-related/Cdh1, confer APC/C substrate specificity. Here, we show that two distinct modes of APC/C function act during Drosophila eye development. Fizzy/Cdc20 controls the early growth of the eye disc anlage and the concomitant entry of glial cells onto the disc. In contrast, fzr/cdh1 acts during neuronal patterning and photoreceptor axon growth, and subsequently affects neuron-glia interaction. To further address the postmitotic role of Fzr/Cdh1 in controlling neuron-glia interaction, we identified a series of novel APC/C candidate substrates. Four of our candidate genes are required for fzr/cdh1 -dependent neuron-glia interaction, including the dynein light chain Dlc90F Taken together, our data show how different modes of APC/C activation can couple early growth and neuron-glia interaction during eye disc development. © 2017. Published by The Company of Biologists Ltd.

Electron molecular beam epitaxy: Layer-by-layer growth of complex oxides via pulsed electron-beam deposition

International Nuclear Information System (INIS)

Comes, Ryan; Liu Hongxue; Lu Jiwei; Gu, Man; Khokhlov, Mikhail; Wolf, Stuart A.

2013-01-01

Complex oxide epitaxial film growth is a rich and exciting field, owing to the wide variety of physical properties present in oxides. These properties include ferroelectricity, ferromagnetism, spin-polarization, and a variety of other correlated phenomena. Traditionally, high quality epitaxial oxide films have been grown via oxide molecular beam epitaxy or pulsed laser deposition. Here, we present the growth of high quality epitaxial films using an alternative approach, the pulsed electron-beam deposition technique. We demonstrate all three epitaxial growth modes in different oxide systems: Frank-van der Merwe (layer-by-layer); Stranski-Krastanov (layer-then-island); and Volmer-Weber (island). Analysis of film quality and morphology is presented and techniques to optimize the morphology of films are discussed.

Complex mode indication function and its applications to spatial domain parameter estimation

Science.gov (United States)

Shih, C. Y.; Tsuei, Y. G.; Allemang, R. J.; Brown, D. L.

1988-10-01

This paper introduces the concept of the Complex Mode Indication Function (CMIF) and its application in spatial domain parameter estimation. The concept of CMIF is developed by performing singular value decomposition (SVD) of the Frequency Response Function (FRF) matrix at each spectral line. The CMIF is defined as the eigenvalues, which are the square of the singular values, solved from the normal matrix formed from the FRF matrix, [ H( jω)] H[ H( jω)], at each spectral line. The CMIF appears to be a simple and efficient method for identifying the modes of the complex system. The CMIF identifies modes by showing the physical magnitude of each mode and the damped natural frequency for each root. Since multiple reference data is applied in CMIF, repeated roots can be detected. The CMIF also gives global modal parameters, such as damped natural frequencies, mode shapes and modal participation vectors. Since CMIF works in the spatial domain, uneven frequency spacing data such as data from spatial sine testing can be used. A second-stage procedure for accurate damped natural frequency and damping estimation as well as mode shape scaling is also discussed in this paper.

Analysis of Optical Fiber Complex Propagation Matrix on the Basis of Vortex Modes

DEFF Research Database (Denmark)

Lyubopytov, Vladimir S.; Tatarczak, Anna; Lu, Xiaofeng

2016-01-01

We propose and experimentally demonstrate a novel method for reconstruction of the complex propagation matrix of optical fibers supporting propagation of multiple vortex modes. This method is based on the azimuthal decomposition approach and allows the complex matrix elements to be determined...... by direct calculations. We apply the proposed method to demonstrate the feasibility of optical compensation for coupling between vortex modes in optical fiber....

An in-plane solid-liquid-solid growth mode for self-avoiding lateral silicon nanowires.

Science.gov (United States)

Yu, Linwei; Alet, Pierre-Jean; Picardi, Gennaro; Roca i Cabarrocas, Pere

2009-03-27

We report an in-plane solid-liquid-solid (IPSLS) mode for obtaining self-avoiding lateral silicon nanowires (SiNW) in a reacting-gas-free annealing process, where the growth of SiNWs is guided by liquid indium drops that transform the surrounding a-SiratioH matrix into crystalline SiNWs. The SiNWs can be approximately mm long, with the smallest diameter down to approximately 22 nm. A high growth rate of >10(2) nm/s and rich evolution dynamics are revealed in a real-time in situ scanning electron microscopy observation. A qualitative growth model is proposed to account for the major features of this IPSLS SiNW growth mode.

Airborne measurements of nucleation mode particles I: coastal nucleation and growth rates

Directory of Open Access Journals (Sweden)

C. D. O'Dowd

2007-01-01

Full Text Available A light aircraft was equipped with a bank of Condensation Particle Counters (CPCs (50% cut from 3–5.4–9.6 nm and a nano-Scanning Mobility Particle Sizer (nSMPS and deployed along the west coast of Ireland, in the vicinity of Mace Head. The objective of the exercise was to provide high resolution micro-physical measurements of the coastal nucleation mode in order to map the spatial extent of new particle production regions and to evaluate the evolution, and associated growth rates of the coastal nucleation-mode aerosol plume. Results indicate that coastal new particle production is occurring over most areas along the land-sea interface with peak concentrations at the coastal plume-head in excess of 106 cm−3. Pseudo-Lagrangian studies of the coastal plume evolution illustrated significant growth of new particles to sizes in excess of 8 nm approximately 10 km downwind of the source region. Close to the plume head (<1 km growth rates can be as high as 123–171 nm h−1, decreasing gradually to 53–72 nm h−1 at 3 km. Further along the plume, at distances up to 10 km, the growth rates are calculated to be 17–32 nm h−1. Growth rates of this magnitude suggest that after a couple of hours, coastal nucleation mode particles can reach significant sizes where they can contribution to the regional aerosol loading.

Fluoroquinolone-gyrase-DNA complexes: two modes of drug binding.

Science.gov (United States)

Mustaev, Arkady; Malik, Muhammad; Zhao, Xilin; Kurepina, Natalia; Luan, Gan; Oppegard, Lisa M; Hiasa, Hiroshi; Marks, Kevin R; Kerns, Robert J; Berger, James M; Drlica, Karl

2014-05-02

DNA gyrase and topoisomerase IV control bacterial DNA topology by breaking DNA, passing duplex DNA through the break, and then resealing the break. This process is subject to reversible corruption by fluoroquinolones, antibacterials that form drug-enzyme-DNA complexes in which the DNA is broken. The complexes, called cleaved complexes because of the presence of DNA breaks, have been crystallized and found to have the fluoroquinolone C-7 ring system facing the GyrB/ParE subunits. As expected from x-ray crystallography, a thiol-reactive, C-7-modified chloroacetyl derivative of ciprofloxacin (Cip-AcCl) formed cross-linked cleaved complexes with mutant GyrB-Cys(466) gyrase as evidenced by resistance to reversal by both EDTA and thermal treatments. Surprisingly, cross-linking was also readily seen with complexes formed by mutant GyrA-G81C gyrase, thereby revealing a novel drug-gyrase interaction not observed in crystal structures. The cross-link between fluoroquinolone and GyrA-G81C gyrase correlated with exceptional bacteriostatic activity for Cip-AcCl with a quinolone-resistant GyrA-G81C variant of Escherichia coli and its Mycobacterium smegmatis equivalent (GyrA-G89C). Cip-AcCl-mediated, irreversible inhibition of DNA replication provided further evidence for a GyrA-drug cross-link. Collectively these data establish the existence of interactions between the fluoroquinolone C-7 ring and both GyrA and GyrB. Because the GyrA-Gly(81) and GyrB-Glu(466) residues are far apart (17 Å) in the crystal structure of cleaved complexes, two modes of quinolone binding must exist. The presence of two binding modes raises the possibility that multiple quinolone-enzyme-DNA complexes can form, a discovery that opens new avenues for exploring and exploiting relationships between drug structure and activity with type II DNA topoisomerases.

Non-linear self-reinforced growth of tearing modes with multiple rational surfaces

International Nuclear Information System (INIS)

Maschke, E.K.; Persson, M.; Dewar, R.L.; Australian National Univ., Canberra, ACT

1993-06-01

The non-linear evolution of tearing modes with multiple rational surfaces is discussed. It is demonstrated that, in the presence of small differential rotation, the non-linear growth might be faster than exponential. This growth occurs as the rotation frequencies of the plasma at the different rational surfaces go into equilibrium

[Effects of different trophic modes on growth characteristics, metabolism and cellular components of Chlorella vulgaris].

Science.gov (United States)

Kong, Weibao; Wang, Yang; Yang, Hong; Xi, Yuqin; Han, Rui; Niu, Shiquan

2015-03-04

We studied the effects of trophic modes related to glucose and light (photoautotrophy, mixotrophy and heterotrophy) on growth, cellular components and carbon metabolic pathway of Chlorella vulgaris. The parameters about growth of algal cells were investigated by using spectroscopy and chromatography techniques. When trophic mode changed from photoautotrophy to mixotrophy and to heterotrophy successively, the concentrations of soluble sugar, lipid and saturated C16/C18 fatty acids in C. vulgaris increased, whereas the concentrations of unsaturated C16, C18 fatty acids, proteins, photosynthetic pigments and 18 relative amino acids decreased. Light and glucose affect the growth, metabolism and the biochemical components biosynthesis of C. vulgaris. Addition of glucose can promote algal biomass accumulation, stimulate the synthesis of carbonaceous components, but inhibit nitrogenous components. Under illumination cultivation, concentration and consumption level of glucose decided the main trophic modes of C. vulgaris. Mixotrophic and heterotrophic cultivation could promote the growth of algal cells.

The study of RMB exchange rate complex networks based on fluctuation mode

Science.gov (United States)

Yao, Can-Zhong; Lin, Ji-Nan; Zheng, Xu-Zhou; Liu, Xiao-Feng

2015-10-01

In the paper, we research on the characteristics of RMB exchange rate time series fluctuation with methods of symbolization and coarse gaining. First, based on fluctuation features of RMB exchange rate, we define the first type of fluctuation mode as one specific foreign currency against RMB in four days' fluctuating situations, and the second type as four different foreign currencies against RMB in one day's fluctuating situation. With the transforming method, we construct the unique-currency and multi-currency complex networks. Further, through analyzing the topological features including out-degree, betweenness centrality and clustering coefficient of fluctuation-mode complex networks, we find that the out-degree distribution of both types of fluctuation mode basically follows power-law distributions with exponents between 1 and 2. The further analysis reveals that the out-degree and the clustering coefficient generally obey the approximated negative correlation. With this result, we confirm previous observations showing that the RMB exchange rate exhibits a characteristic of long-range memory. Finally, we analyze the most probable transmission route of fluctuation modes, and provide probability prediction matrix. The transmission route for RMB exchange rate fluctuation modes exhibits the characteristics of partially closed loop, repeat and reversibility, which lays a solid foundation for predicting RMB exchange rate fluctuation patterns with large volume of data.

High power blue LED development using different growth modes

Energy Technology Data Exchange (ETDEWEB)

Lee, Dong S.; Florescu, Doru I.; Ramer, Jeff C.; Merai, Vinod; Parekh, Aniruddh; Begarney, Michael J.; Armour, Eric A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); Lu Dong [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); School of Engineering, Rutgers University, Piscataway, NJ 08854 (United States)

2004-09-01

Blue high brightness light emitting diodes (HB-LEDs) have been developed using different growth modes in the active layers. Piezoelectric field engineering improves the optical output power in multiple quantum well (MQW) LEDs by inserting an optimized transitional superlattice (TSL) before the active MQW layers. Within single quantum well (SQW) LEDs, quasi-Quantum Dot (QD) growth for Indium localization has been realized. The SQW LED output power exceeds the strain engineered MQW LEDs. The experimental data indicates that Indium localization enhances overall quantum efficiency and results in increased output power for HB-LEDs. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Complexity growth in minimal massive 3D gravity

Science.gov (United States)

Qaemmaqami, Mohammad M.

2018-01-01

We study the complexity growth by using "complexity =action " (CA) proposal in the minimal massive 3D gravity (MMG) model which is proposed for resolving the bulk-boundary clash problem of topologically massive gravity (TMG). We observe that the rate of the complexity growth for Banados-Teitelboim-Zanelli (BTZ) black hole saturates the proposed bound by physical mass of the BTZ black hole in the MMG model, when the angular momentum parameter and the inner horizon of black hole goes to zero.

Relations among the crack growth modes resulting from tensor splitting

Czech Academy of Sciences Publication Activity Database

Kafka, Vratislav

2015-01-01

Roč. 60, č. 4 (2015), s. 319-335 ISSN 0001-7043 Institutional support: RVO:68378297 Keywords : fracture mechanics * combination of crack-growth modes * non-local effect * tensor splitting Subject RIV: JL - Materials Fatigue, Friction Mechanics http://journal.it.cas.cz/60(15)4-Contents/60(15)4a.pdf

Phase diagram of interfacial growth modes by vapor deposition and its application for ZnO nanostructures

Science.gov (United States)

Shu, Da-Jun; Xiong, Xiang; Liu, Ming; Wang, Mu

2017-09-01

Interfacial growth from vapor has been extensively studied. However, a straightforward picture of the growth mode under different growth conditions is still lacking. In this paper, we develop a comprehensive interfacial growth theory based on the stochastic approach. Using a critical interisland separation, we construct a general phase diagram of the growth modes. It has been revealed that if the Ehrlich-Schwoebel barrier EES is smaller than a critical value, the interfacial growth proceeds in a layer-by-layer (LBL) mode at any deposition rate. However, if EES is larger than the critical value, LBL growth occurs only at very small or very large deposition rates relative to the intralayer hopping rate, and multilayer (ML) growth occurs at a moderate deposition rate. Experiments with zinc oxide growth by chemical vapor deposition have been designed to qualitatively demonstrate the theoretical model. By changing the flux of the carrier gas (nitrogen gas) in chemical vapor deposition, we realize LBL, ML, and then reentrance of LBL homoepitaxial growth of ZnO successively. Moreover, we find that surface kinetics of ZnO is suppressed by decreasing oxygen partial pressure by comparing the experimental observations and theoretical models, which is supported by our recent first-principles calculations. Since the influence of the substrate and the growth species on growth can approximately be represented by binding energy and surface kinetics, we suggest that the phase diagram is essential for interfacial growth of different materials by vapor deposition.

STABILIZATION OF UNUSUAL SUBSTRATE COORDINATION MODES IN DINUCLEAR MACROCYCLIC COMPLEXES

Directory of Open Access Journals (Sweden)

Vasile Lozan

2010-06-01

Full Text Available The steric protection offered by the macrobinucleating hexaazaditiophenolate ligand (L allows for the preparation of the first stable dinuclear nickel(II borohydride bridged complex, which reacts rapidly with elemental sulphur producing a tetranuclear nickel(II complex [{(LNi2}2(μ-S6]2+ bearing a helical μ4-hexa- sulfide ligand. The [(LCoII 2]2+ fragment have been able to trap a monomethyl orthomolybdate in the binding pocket. Unusual coordination modes of substrate in dinuclear macrocyclic compounds was demonstrated.

Complexity growth in massive gravity theories, the effects of chirality, and more

Science.gov (United States)

Ghodrati, Mahdis

2017-11-01

To study the effect of parity violation on the rate of complexity growth, by using "complexity=action " conjecture, we find the complexity growth rates in different solutions of the chiral theory of topologically massive gravity (TMG) and parity-preserving theory of new massive gravity (NMG). Using the results, one can see that decreasing the parameter μ , which increases the effect of the Chern-Simons term and increases chirality, would increase the rate of growth of complexity. Also one can observe a stronger correlation between complexity growth and temperature rather than complexity growth and entropy. At the end we comment on the possible meaning of the deforming term of chiral Liouville action for the rate of complexity growth of warped conformal field theories in the tensor network renormalization picture.

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics

Science.gov (United States)

Lepczyk, Christopher A.; Miura, Tomoaki; Fox, Jefferson M.

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001–2006 and 2006–2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries. PMID:29734346

Quantifying urban growth patterns in Hanoi using landscape expansion modes and time series spatial metrics.

Science.gov (United States)

Nong, Duong H; Lepczyk, Christopher A; Miura, Tomoaki; Fox, Jefferson M

2018-01-01

Urbanization has been driven by various social, economic, and political factors around the world for centuries. Because urbanization continues unabated in many places, it is crucial to understand patterns of urbanization and their potential ecological and environmental impacts. Given this need, the objectives of our study were to quantify urban growth rates, growth modes, and resultant changes in the landscape pattern of urbanization in Hanoi, Vietnam from 1993 to 2010 and to evaluate the extent to which the process of urban growth in Hanoi conformed to the diffusion-coalescence theory. We analyzed the spatiotemporal patterns and dynamics of the built-up land in Hanoi using landscape expansion modes, spatial metrics, and a gradient approach. Urbanization was most pronounced in the periods of 2001-2006 and 2006-2010 at a distance of 10 to 35 km around the urban center. Over the 17 year period urban expansion in Hanoi was dominated by infilling and edge expansion growth modes. Our findings support the diffusion-coalescence theory of urbanization. The shift of the urban growth areas over time and the dynamic nature of the spatial metrics revealed important information about our understanding of the urban growth process and cycle. Furthermore, our findings can be used to evaluate urban planning policies and aid in urbanization issues in rapidly urbanizing countries.

Growth of the double Tearing mode in a plasma cylinder

International Nuclear Information System (INIS)

Gatilov, V.V.; Sagalakov, A.M.; Ul'chenko, V.F.

1989-01-01

Within the framework of the linear theory the growth of Tearing modes in collisional plasma of a cylindrical filament with a free boundary in the presence of two resonance surfaces is studied. The boundary problems for the system of Kadomtsev-Pogutse equation were solved numerically using the method of differential run which was widely used to study the stability of viscous liquid flows. The asymptotic dependences for the increments are determined. The regular behaviour of increments in the case of drawing together of resonance surfaces is fiound. A very strong destabilizing factor of conductivity inhomogeneity on modes 1/1, 2/1 connected with the resonance surface in the near-the-boundary plasma region is found

Tearing mode growth in a regime of weak magnetic shear

International Nuclear Information System (INIS)

Riyopoulos, S.; Hazeltine, R.D.

1987-06-01

The nonlinear growth for the m/n ≥ 2 resistive tearing mode is studied in case when the rational surface q(r 0 ) = m/n falls in a regime of weak magnetic shear, q'(r 0 ) ≅ 0. The island width is determined self-consistently from the nonlinear, zero-helicity component of the perturbed magnetic flux that provides the local shear. It is found that the magnetic perturbation keeps growing exponentially in the nonlinear regime on a hybrid resistive-Alfvenic time scale, while the island width and the vorticity grow on a much slower time scale. Accordingly, much faster release of magnetic energy results for modes growing near minima of hollow q profiles

Low-Complexity Hierarchical Mode Decision Algorithms Targeting VLSI Architecture Design for the H.264/AVC Video Encoder

Directory of Open Access Journals (Sweden)

Guilherme Corrêa

2012-01-01

Full Text Available In H.264/AVC, the encoding process can occur according to one of the 13 intraframe coding modes or according to one of the 8 available interframes block sizes, besides the SKIP mode. In the Joint Model reference software, the choice of the best mode is performed through exhaustive executions of the entire encoding process, which significantly increases the encoder's computational complexity and sometimes even forbids its use in real-time applications. Considering this context, this work proposes a set of heuristic algorithms targeting hardware architectures that lead to earlier selection of one encoding mode. The amount of repetitions of the encoding process is reduced by 47 times, at the cost of a relatively small cost in compression performance. When compared to other works, the fast hierarchical mode decision results are expressively more satisfactory in terms of computational complexity reduction, quality, and bit rate. The low-complexity mode decision architecture proposed is thus a very good option for real-time coding of high-resolution videos. The solution is especially interesting for embedded and mobile applications with support to multimedia systems, since it yields good compression rates and image quality with a very high reduction in the encoder complexity.

Growth of fullerene on Ag and hydrogen-passivated Si substrates: Effect of electron beam exposure on growth modes

International Nuclear Information System (INIS)

Rundhe, M.V.; Dev, B.N.

2008-01-01

We have used Auger electron spectroscopy (AES) to investigate the effect of electron beam exposure on growth modes of fullerene (C 60 ) on substrates like Ag and hydrogen-passivated Si(1 1 1). The electron beam comprises of 3.4 keV electrons, which are used in the AES study. To investigate the effect, Auger signal (AS) vs. deposition time (t) measurements were conducted in a sequential mode, i.e., alternating deposition of C 60 and analysis using the electron beam. Duration of AES data collection after each deposition was the duration of exposure to electron beam in this experiment. For the growth study of C 60 on Ag, three AS-t plots were recorded for three different durations of exposure to electron beam. Changes in the AS-t plot, depending on the duration of exposure to the electron beam, reflect the electron beam-induced damage. Electron beam-induced damages of C 60 produce carbon materials of different densities and consequently transmission coefficient (α) of Auger electron through this material changes. In order to fit the AES (AS vs. t) data a model has been used which simultaneously provides the growth mode and the transmission coefficient. Observation of an increasing transmission coefficient with the increasing duration of exposure to the electron beam from α=0.34 to 0.60 indicates the change of the nature of the carbon material due to the partial damage of C 60

Dense SDM (12-core × 3-mode) transmission over 527 km with 33.2-ns mode-dispersion employing low-complexity parallel MIMO frequency-domain equalization

DEFF Research Database (Denmark)

Shibahara, K.; Mizuno, T.; Takara, H.

We demonstrate 12-core × 3-mode dense SDM transmission over 527 km graded-index multi-core few-mode fiber without mode-dispersion management. Employing low baud rate multi-carrier signal and frequency-domain equalization enables 33.2-ns DMD compensation with low computational complexity. © 2015 OSA...

Research on the co-movement between high-end talent and economic growth: A complex network approach

Science.gov (United States)

Zhang, Zhen; Wang, Minggang; Xu, Hua; Zhang, Wenbin; Tian, Lixin

2018-02-01

The major goal of this paper is to focus on the co-movement between high-end talent and economic growth by a complex network approach. Firstly, the national high-end talent development efficiency from 1990 to 2015 is taken as the quantitative index to measure the development of high-end talent. The added values of the primary industry, secondary industry, tertiary industry are selected as economic growth indexes, and all the selected sample data are standardized by the mean value processing method. Secondly, let seven months as the length of the sliding window, and one month as the sliding step, then the grey correlation degrees between systems are measured using the slope correlation degrees, and the grey correlation degree sequence is mapped into the symbol series composed by three symbols { Y , O , N } based on the coarse graining method. Let three characters as a mode, the nodes are obtained by the modes according to the time sequence. Let the transformation between the modal be the edge, and the times of the transformation be weight, then the co-movement networks between national high-end talent development efficiency and the added values of the primary industry, secondary industry, tertiary industry are built respectively. Finally, the dynamic characteristics of the networks are analysed by the node strength, strength distribution, weighted clustering coefficient, conversion cycle of the modes and the transition between the co-movement modes. The results indicate that there are mutual influence and promotion relations between the national high-end talent development efficiency and the added values of the primary, secondary and tertiary industry.

Growth modes of individual ferrite grains in the austenite to ferrite transformation of low carbon steels

International Nuclear Information System (INIS)

Li, D.Z.; Xiao, N.M.; Lan, Y.J.; Zheng, C.W.; Li, Y.Y.

2007-01-01

The mesoscale deterministic cellular automaton (CA) method and probabilistic Q-state Potts-based Monte Carlo (MC) model have been adopted to investigate independently the individual growth behavior of ferrite grain during the austenite (γ)-ferrite (α) transformation. In these models, the γ-α phase transformation and ferrite grain coarsening induced by α/α grain boundary migration could be simulated simultaneously. The simulations demonstrated that both the hard impingement (ferrite grain coarsening) and the soft impingement (overlapping carbon concentration field) have a great influence on the individual ferrite growth behavior. Generally, ferrite grains displayed six modes of growth behavior: parabolic growth, delayed nucleation and growth, temporary shrinkage, partial shrinkage, complete shrinkage and accelerated growth in the transformation. Some modes have been observed before by the synchrotron X-ray diffraction experiment. The mesoscopic simulation provides an alternative tool for investigating both the individual grain growth behavior and the overall transformation behavior simultaneously during transformation

Fatigue crack growth and life prediction under mixed-mode loading

Science.gov (United States)

Sajith, S.; Murthy, K. S. R. K.; Robi, P. S.

2018-04-01

Fatigue crack growth life as a function of crack length is essential for the prevention of catastrophic failures from damage tolerance perspective. In damage tolerance design approach, principles of fracture mechanics are usually applied to predict the fatigue life of structural components. Numerical prediction of crack growth versus number of cycles is essential in damage tolerance design. For cracks under mixed mode I/II loading, modified Paris law (d/a d N =C (ΔKe q ) m ) along with different equivalent stress intensity factor (ΔKeq) model is used for fatigue crack growth rate prediction. There are a large number of ΔKeq models available for the mixed mode I/II loading, the selection of proper ΔKeq model has significant impact on fatigue life prediction. In the present investigation, the performance of ΔKeq models in fatigue life prediction is compared with respect to the experimental findings as there are no guidelines/suggestions available on the selection of these models for accurate and/or conservative predictions of fatigue life. Within the limitations of availability of experimental data and currently available numerical simulation techniques, the results of present study attempt to outline models that would provide accurate and conservative life predictions. Such a study aid the numerical analysts or engineers in the proper selection of the model for numerical simulation of the fatigue life. Moreover, the present investigation also suggests a procedure to enhance the accuracy of life prediction using Paris law.

Rapid solidification growth mode transitions in Al-Si alloys by dynamic transmission electron microscopy

International Nuclear Information System (INIS)

Roehling, John D.; Coughlin, Daniel R.; Gibbs, John W.; Baldwin, J. Kevin; Mertens, James C.E.; Campbell, Geoffrey H.; Clarke, Amy J.; McKeown, Joseph T.

2017-01-01

In situ dynamic transmission electron microscope (DTEM) imaging of Al-Si thin-film alloys was performed to investigate rapid solidification behavior. Solidification of alloys with compositions from 1 to 15 atomic percent Si was imaged during pulsed laser melting and subsequent solidification. Solely α-Al solidification was observed in Al-1Si and Al-3Si alloys, and solely kinetically modified eutectic growth was observed in Al-6Si and Al-9Si alloys. A transition in the solidification mode in eutectic and hypereutectic alloys (Al-12Si and Al-15Si) from nucleated α-Al dendrites at lower solidification velocities to planar eutectic growth at higher solidification velocities was observed, departing from trends previously seen in laser-track melting experiments. Comparisons of the growth modes and corresponding velocities are compared with previous solidification models, and implications regarding the models are discussed.

Rate-dependent mode I interlaminar crack growth mechanisms in graphite/epoxy and graphite/PEEK

Science.gov (United States)

Gillespie, J. W., Jr.; Carlsson, L. A.; Smiley, A. J.

1987-01-01

In this paper the mode I fracture behavior of graphite/epoxy and graphite/PEEK composites is examined over four decades of crosshead rates (0.25-250 mm/min). Straight-sided double-cantilever-beam specimens consisting of unidirectional laminates were tested at room temperature. For graphite/epoxy the load-deflection response was linear to fracture, and stable slow crack growth initiating at the highest load level was observed for all rates tested. In contrast, mode I crack growth in the graphite/PEEK material was often unstable and showed stick-slip behavior. Subcritical crack growth occurring prior to the onset of fracture was observed at intermediate displacement rates. A mechanism for the fracture behavior of the graphite/PEEK material (based on viscoelastic, plastic, and microcrack coalescence in the process zone) is proposed and related to the observed rate-dependent phenomena.

Effects of multiple modes interaction on the resistive wall mode instability

International Nuclear Information System (INIS)

Chen, Longxi; Lei, Wenqing; Ma, Zhiwei; Wu, Bin

2013-01-01

The effects of multiple modes interaction on the resistive wall mode (RWM) are studied in a slab geometry with and without plasma flow. The modes interaction can have a large effect on both the linear growth rate and the nonlinear saturation level of the RWM. We found that modes interaction can suppress the linear growth rate for the most unstable mode. The plasma flow can also help to control the growth of the RWM. The RWM can be stabilized completely by a plasma flow when considering the modes interaction. The effect of modes interaction on the RWM is stronger for the mode rational surface in the vacuum than that in the plasma. The modes interaction results in a substantially lowered saturation level for the most unstable RWM. (paper)

Structural properties, crystal quality and growth modes of MOCVD-grown AlN with TMAl pretreatment of sapphire substrate

KAUST Repository

Sun, Haiding; Wu, Feng; Altahtamouni, Talal Mohammed Ahmad; Alfaraj, Nasir; Li, Kun; Detchprohm, Theeradetch; Dupuis, Russell; Li, Xiaohang

2017-01-01

The growth of high quality AlN epitaxial films relies on precise control of the initial growth stages. In this work, we examined the influence of the trimethylaluminum (TMAl) pretreatment of sapphire substrates on the structural properties, crystal quality and growth modes of heteroepitaxial AlN films on (0001) sapphire substrates. Without the pretreatment, the AlN films nucleated on the smooth surface but exhibited mixed crystallographic Al- (N-) polarity, resulting in rough AlN film surfaces. With increasing the pretreatment time from 1 to 5 s, the N-polarity started to be impeded. However, small islands were formed on sapphire surface due to the decompostion of TMAl. As a result, small voids became noticeable at the nucleation layer (NL) because the growth started as quasi three-dimensional (3D) but transformed to 2D mode as the film grew thicker and got coalesced, leading to smoother and Al-polar films. On the other hand, longer pretreatment time of 40 s formed large 3D islands on sapphire, and thus initiated a 3D-growth mode of the AlN film, generating Al-polar AlN nanocolumns with different facets, which resulted into rougher film surfaces. The epitaxial growth modes and their correlation with the AlN film crystal quality under different TMAl pretreatments are also discussed.

Structural properties, crystal quality and growth modes of MOCVD-grown AlN with TMAl pretreatment of sapphire substrate

KAUST Repository

Sun, Haiding

2017-08-08

The growth of high quality AlN epitaxial films relies on precise control of the initial growth stages. In this work, we examined the influence of the trimethylaluminum (TMAl) pretreatment of sapphire substrates on the structural properties, crystal quality and growth modes of heteroepitaxial AlN films on (0001) sapphire substrates. Without the pretreatment, the AlN films nucleated on the smooth surface but exhibited mixed crystallographic Al- (N-) polarity, resulting in rough AlN film surfaces. With increasing the pretreatment time from 1 to 5 s, the N-polarity started to be impeded. However, small islands were formed on sapphire surface due to the decompostion of TMAl. As a result, small voids became noticeable at the nucleation layer (NL) because the growth started as quasi three-dimensional (3D) but transformed to 2D mode as the film grew thicker and got coalesced, leading to smoother and Al-polar films. On the other hand, longer pretreatment time of 40 s formed large 3D islands on sapphire, and thus initiated a 3D-growth mode of the AlN film, generating Al-polar AlN nanocolumns with different facets, which resulted into rougher film surfaces. The epitaxial growth modes and their correlation with the AlN film crystal quality under different TMAl pretreatments are also discussed.

Relationship Between Unusual High-Temperature Fatigue Crack Growth Threshold Behavior in Superalloys and Sudden Failure Mode Transitions

Science.gov (United States)

Telesman, J.; Smith, T. M.; Gabb, T. P.; Ring, A. J.

2017-01-01

An investigation of high temperature cyclic fatigue crack growth (FCG) threshold behavior of two advanced nickel disk alloys was conducted. The focus of the study was the unusual crossover effect in the near-threshold region of these type of alloys where conditions which produce higher crack growth rates in the Paris regime, produce higher resistance to crack growth in the near threshold regime. It was shown that this crossover effect is associated with a sudden change in the fatigue failure mode from a predominant transgranular mode in the Paris regime to fully intergranular mode in the threshold fatigue crack growth region. This type of a sudden change in the fracture mechanisms has not been previously reported and is surprising considering that intergranular failure is typically associated with faster crack growth rates and not the slow FCG rates of the near-threshold regime. By characterizing this behavior as a function of test temperature, environment and cyclic frequency, it was determined that both the crossover effect and the onset of intergranular failure are caused by environmentally driven mechanisms which have not as yet been fully identified. A plausible explanation for the observed behavior is proposed.

On synchronisation of a class of complex chaotic systems with complex unknown parameters via integral sliding mode control

Science.gov (United States)

Tirandaz, Hamed; Karami-Mollaee, Ali

2018-06-01

Chaotic systems demonstrate complex behaviour in their state variables and their parameters, which generate some challenges and consequences. This paper presents a new synchronisation scheme based on integral sliding mode control (ISMC) method on a class of complex chaotic systems with complex unknown parameters. Synchronisation between corresponding states of a class of complex chaotic systems and also convergence of the errors of the system parameters to zero point are studied. The designed feedback control vector and complex unknown parameter vector are analytically achieved based on the Lyapunov stability theory. Moreover, the effectiveness of the proposed methodology is verified by synchronisation of the Chen complex system and the Lorenz complex systems as the leader and the follower chaotic systems, respectively. In conclusion, some numerical simulations related to the synchronisation methodology is given to illustrate the effectiveness of the theoretical discussions.

Nonlinear eigen-mode structures in complex astroclouds

Science.gov (United States)

Karmakar, P. K.; Haloi, A.

2017-05-01

The evolutionary dynamics of strongly nonlinear waves (of arbitrary amplitude) in an inhomogeneous complex astrophysical viscous cloud is investigated without recourse to any kind of swindle. It consists of warm lighter electrons and ions (Boltzmanian); and cold massive bi-polar dust grains (inertial fluids) alongside vigorous neutral dynamics in quasi-neural hydrodynamic equilibrium. Application of the Sagdeev pseudo-potential method transforms the analytic model into a conjugated pair of intermixed non-integrable energy integral laws. A natural excitation of electrostatic quasi-monotonic compressive dispersive shock-like eigen-modes is numerically demonstrated. In contrast, the self-gravitational waves grow purely as non-monotonic compressive oscillatory shock-like structures. The unique features of both the distinct classes are depicted. Their non-trivial significance in the astro-context is emphasized.

The initial growth of complex oxides : study and manipulation

NARCIS (Netherlands)

Rijnders, Augustinus J.H.M.

2001-01-01

In this thesis, the initial growth stage, i.e., nucleation and growth of the first few unit cell layers, of complex oxides was studied in real time during pulsed laser deposition (PLD). These studies were performed at their optimal epitaxial growth conditions, i.e., high temperature and high oxygen

Face/core debond fatigue crack growth characterization using the sandwich mixed mode bending specimen

DEFF Research Database (Denmark)

Manca, Marcello; Quispitupa, Amilcar; Berggreen, Christian

2012-01-01

Face/core fatigue crack growth in foam-cored sandwich composites is examined using the mixed mode bending (MMB) test method. The mixed mode loading at the debond crack tip is controlled by changing the load application point in the MMB test fixture. Sandwich specimens were manufactured using H45...... and H100 PVC foam cores and E-glass/polyester face sheets. All specimens were pre-cracked in order to define a sharp crack front. The static debond fracture toughness for each material configuration was measured at different mode-mixity phase angles. Fatigue tests were performed at 80% of the static...

Improved Empirical Mode Decomposition Algorithm of Processing Complex Signal for IoT Application

OpenAIRE

Yang, Xianzhao; Cheng, Gengguo; Liu, Huikang

2015-01-01

Hilbert-Huang transform is widely used in signal analysis. However, due to its inadequacy in estimating both the maximum and the minimum values of the signals at both ends of the border, traditional HHT is easy to produce boundary error in empirical mode decomposition (EMD) process. To overcome this deficiency, this paper proposes an enhanced empirical mode decomposition algorithm for processing complex signal. Our work mainly focuses on two aspects. On one hand, we develop a technique to obt...

Nonlinear eigen-mode structures in complex astroclouds

International Nuclear Information System (INIS)

Karmakar, P K; Haloi, A

2017-01-01

The evolutionary dynamics of strongly nonlinear waves (of arbitrary amplitude) in an inhomogeneous complex astrophysical viscous cloud is investigated without recourse to any kind of swindle. It consists of warm lighter electrons and ions (Boltzmanian); and cold massive bi-polar dust grains (inertial fluids) alongside vigorous neutral dynamics in quasi-neural hydrodynamic equilibrium. Application of the Sagdeev pseudo-potential method transforms the analytic model into a conjugated pair of intermixed non-integrable energy integral laws. A natural excitation of electrostatic quasi-monotonic compressive dispersive shock-like eigen-modes is numerically demonstrated. In contrast, the self-gravitational waves grow purely as non-monotonic compressive oscillatory shock-like structures. The unique features of both the distinct classes are depicted. Their non-trivial significance in the astro-context is emphasized. (paper)

Growth modes of pentacene films obtained by pulsed laser deposition

International Nuclear Information System (INIS)

Wisz, G.; Kuzma, M.; Virt, I.; Sagan, P.; Rudyj, I.

2011-01-01

Thin pentacene films were deposited on KCl and ITO/glass substrates by the pulsed laser deposition method (PLD) using a YAG:Nd 3+ laser with a second harmonic (λ = 532 nm). We compared the structure of the layer on differently oriented substrates with respect to the pentacene plasma plume - vertical and parallel orientation. The structure of the layers formed was examined using SEM, RHEED and THEED methods. The lattice parameters of the layer deposited on KCl were determined from THEED pattern (a = 5.928 A, b 7.874 A, c = 14,98 A, α = 76.54 o , β 75.17 o , γ = 89.20 o ). The preferred direction [11-bar 0] of the layer growth on KCl substrate was addressed. The effect of the substrate orientation results in a different growth mode of the layers.

Monitoring of biofilm growth using ATR-leaky mode spectroscopy

International Nuclear Information System (INIS)

Leitz, M.; Franke, H.; Grattan, K.T.V.; Tamachkiarow, A.

2002-01-01

An approach to the in situ monitoring of biofilm formation using the technique of ATR-leaky mode spectroscopy is given as an example for the case of Cytophaga. The biofilm growth was studied on an aluminium layer and on a bilayer of the hydrogel agarose on aluminium. This metal was chosen because of its chemical stability in aqueous systems. The spectra obtained have been recorded using a flow cell to contain the suspension and nutrients over a period of several days. In the case considered using a prism surface coated with agarose, the experiments were performed by breeding in an incubator. (author)

Growth mode transition of tetrahydrofuran clathrate hydrates in the guest/host concentration boundary layer.

Science.gov (United States)

Sabase, Yuichiro; Nagashima, Kazushige

2009-11-19

Clathrate hydrates are known to form a thin film along a guest/host boundary. We present here the first report of tetrahydrofuran (THF) clathrate hydrate formation in a THF/water concentration boundary layer. We found that the THF-water system also forms a hydrate film separating the guest/host phases. The lateral growth rate of the film increases as supercooling increases. The thickness of the film at the growth tip decreases as supercooling and the lateral growth rate increase. These tendencies are consistent with reports of experiments for other hydrates and predictions of heat-transfer models. After film formation and slight melting, two types of growth modes are observed, depending on temperature T. At T = 3.0 degrees C, the film slowly thickens. The thickening rate is much lower than the lateral growth rate, as reported for other hydrates. At T agglomerate of small polycrystalline hydrates forms in each phase. Grain boundaries in the film and pore spaces in the agglomerate act as paths for permeation of each liquid. Timing when continuous nucleation starts is dominantly controlled by the time of initiation of liquid permeation through the film. Digital particle image velocimetry analysis of the agglomerate shows that it expands not by growth at the advancing front but rather by continuous nucleation in the interior. Expansion rates of the agglomerate tend to be higher for the cases of multipermeation paths in the film and the thinner film. We suppose that the growth mode transition to continuous nucleation is caused by the memory effect due to slight melting of the hydrate film.

Direct migration motion estimation and mode decision to decoder for a low-complexity decoder Wyner-Ziv video coding

Science.gov (United States)

Lei, Ted Chih-Wei; Tseng, Fan-Shuo

2017-07-01

This paper addresses the problem of high-computational complexity decoding in traditional Wyner-Ziv video coding (WZVC). The key focus is the migration of two traditionally high-computationally complex encoder algorithms, namely motion estimation and mode decision. In order to reduce the computational burden in this process, the proposed architecture adopts the partial boundary matching algorithm and four flexible types of block mode decision at the decoder. This approach does away with the need for motion estimation and mode decision at the encoder. The experimental results show that the proposed padding block-based WZVC not only decreases decoder complexity to approximately one hundredth that of the state-of-the-art DISCOVER decoding but also outperforms DISCOVER codec by up to 3 to 4 dB.

Formation of complex wedding-cake morphologies during homoepitaxial film growth of Ag on Ag(111): atomistic, step-dynamics, and continuum modeling

International Nuclear Information System (INIS)

Li Maozhi; Han, Yong; Thiel, P A; Evans, J W

2009-01-01

An atomistic lattice-gas model is developed which successfully describes all key features of the complex mounded morphologies which develop during deposition of Ag films on Ag(111) surfaces. We focus on this homoepitaxial thin film growth process below 200 K. The unstable multilayer growth mode derives from the presence of a large Ehrlich-Schwoebel step-edge barrier, for which we characterize both the step-orientation dependence and the magnitude. Step-dynamics modeling is applied to further characterize and elucidate the evolution of the vertical profiles of these wedding-cake-like mounds. Suitable coarse-graining of these step-dynamics equations leads to instructive continuum formulations for mound evolution.

On using the Hilbert transform for blind identification of complex modes: A practical approach

Science.gov (United States)

Antunes, Jose; Debut, Vincent; Piteau, Pilippe; Delaune, Xavier; Borsoi, Laurent

2018-01-01

The modal identification of dynamical systems under operational conditions, when subjected to wide-band unmeasured excitations, is today a viable alternative to more traditional modal identification approaches based on processing sets of measured FRFs or impulse responses. Among current techniques for performing operational modal identification, the so-called blind identification methods are the subject of considerable investigation. In particular, the SOBI (Second-Order Blind Identification) method was found to be quite efficient. SOBI was originally developed for systems with normal modes. To address systems with complex modes, various extension approaches have been proposed, in particular: (a) Using a first-order state-space formulation for the system dynamics; (b) Building complex analytic signals from the measured responses using the Hilbert transform. In this paper we further explore the latter option, which is conceptually interesting while preserving the model order and size. Focus is on applicability of the SOBI technique for extracting the modal responses from analytic signals built from a set of vibratory responses. The novelty of this work is to propose a straightforward computational procedure for obtaining the complex cross-correlation response matrix to be used for the modal identification procedure. After clarifying subtle aspects of the general theoretical framework, we demonstrate that the correlation matrix of the analytic responses can be computed through a Hilbert transform of the real correlation matrix, so that the actual time-domain responses are no longer required for modal identification purposes. The numerical validation of the proposed technique is presented based on time-domain simulations of a conceptual physical multi-modal system, designed to display modes ranging from normal to highly complex, while keeping modal damping low and nearly independent of the modal complexity, and which can prove very interesting in test bench

Ion temperature gradient modes in toroidal helical systems

Energy Technology Data Exchange (ETDEWEB)

Kuroda, T. [Graduate University for Advanced Studies, Toki, Gifu (Japan); Sugama, H.; Kanno, R.; Okamoto, M.

2000-04-01

Linear properties of ion temperature gradient (ITG) modes in helical systems are studied. The real frequency, growth rate, and eigenfunction are obtained for both stable and unstable cases by solving a kinetic integral equation with proper analytic continuation performed in the complex frequency plane. Based on the model magnetic configuration for toroidal helical systems like the Large Helical Device (LHD), dependences of the ITG mode properties on various plasma equilibrium parameters are investigated. Particularly, relative effects of {nabla}B-curvature drifts driven by the toroidicity and by the helical ripples are examined in order to compare the ITG modes in helical systems with those in tokamaks. (author)

Ion temperature gradient modes in toroidal helical systems

International Nuclear Information System (INIS)

Kuroda, T.; Sugama, H.; Kanno, R.; Okamoto, M.

2000-04-01

Linear properties of ion temperature gradient (ITG) modes in helical systems are studied. The real frequency, growth rate, and eigenfunction are obtained for both stable and unstable cases by solving a kinetic integral equation with proper analytic continuation performed in the complex frequency plane. Based on the model magnetic configuration for toroidal helical systems like the Large Helical Device (LHD), dependences of the ITG mode properties on various plasma equilibrium parameters are investigated. Particularly, relative effects of ∇B-curvature drifts driven by the toroidicity and by the helical ripples are examined in order to compare the ITG modes in helical systems with those in tokamaks. (author)

Linear growth rates of resistive tearing modes with sub-Alfvénic streaming flow

International Nuclear Information System (INIS)

Wu, L. N.; Ma, Z. W.

2014-01-01

The tearing instability with sub-Alfvénic streaming flow along the external magnetic field is investigated using resistive MHD simulation. It is found that the growth rate of the tearing mode instability is larger than that without the streaming flow. With the streaming flow, there exist two Alfvén resonance layers near the central current sheet. The larger perturbation of the magnetic field in two closer Alfvén resonance layers could lead to formation of the observed cone structure and can largely enhance the development of the tearing mode for a narrower streaming flow. For a broader streaming flow, a larger separation of Alfvén resonance layers reduces the magnetic reconnection. The linear growth rate decreases with increase of the streaming flow thickness. The growth rate of the tearing instability also depends on the plasma beta (β). When the streaming flow is embedded in the current sheet, the growth rate increases with β if β  s , but decreases if β > β s . The existence of the specific value β s can be attributed to competition between the suppressing effect of β and the enhancing effect of the streaming flow on the magnetic reconnection. The critical value β s increases with increase of the streaming flow strength

Factors influencing the temporal growth rate of the high order TM{sub 0n} modes in the Ka-band overmoded Cherenkov oscillator

Energy Technology Data Exchange (ETDEWEB)

Wu, Dapeng, E-mail: vipbenjamin@163.com; Shu, Ting; Ju, Jinchuan [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

2015-06-15

When the wavelength of overmoded Cherenkov oscillator goes into Ka-band, power handling capacity becomes an essential issue. Using the TM{sub 02} mode or higher order TM{sub 0n} modes as the operating mode is a potential solution. This paper is aimed to find some proper parameters to make the temporal growth rate of the TM{sub 02} mode higher in our previously studied Gigawatt (GW)-class Ka band oscillator. An accurate and fast calculation method of the “hot” dispersion equation is derived for rectangular corrugated SWSs, which are widely used in the high frequency Cherenkov devices. Then, factors that affect the temporal growth rate of the high order TM{sub 0n} modes are analyzed, including the depth of corrugation, the radius of drift tube, and the diode voltage. Results show that, when parameters are chosen properly, the temporal growth rate of the TM{sub 02} mode can be as high as 0.3 ns{sup −1}.

On the growth estimates of entire functions of double complex variables

Directory of Open Access Journals (Sweden)

Sanjib Datta

2017-08-01

Full Text Available Recently Datta et al. (2016 introduced the idea of relative type and relative weak type of entire functions of two complex variables with respect to another entire function of two complex variables and prove some related growth properties of it. In this paper, further we study some growth properties of entire functions of two complex variables on the basis of their relative types and relative weak types as introduced by Datta et al (2016.

Equalizer Complexity for 6-LP Mode 112 Gbit/s m-ary DP-QAM Space Division Multiplexed Transmission in Strongly Coupled Few-Mode-Fibers

DEFF Research Database (Denmark)

Asif, Rameez; Ye, Feihong; Morioka, Toshio

2015-01-01

12×12 multiple-input multiple-output (MIMO) adaptive digital signal processing (DSP). Time domain equalization (TDE) is realized to implement the linear adaptive MIMO module that is implemented in blind mode using conventional constant-modulusalgorithm (CMA) for finite impulse response (FIR) adaptive......We have quantified equalizer complexity for transmitting dual-polarized 6-LP modes (LP01, LP11a, LP11b, LP21a, LP21b and LP02) of 112 Gbit/s m-ary QAM (m=4, 16, 32, 64, 256) single carrier signals over 20 km step-index few-mode fiber. The transmitted signals are strongly coupled and recovered using...

Interactions between default mode and control networks as a function of increasing cognitive reasoning complexity.

Science.gov (United States)

Hearne, Luke; Cocchi, Luca; Zalesky, Andrew; Mattingley, Jason B

2015-07-01

Successful performance of challenging cognitive tasks depends on a consistent functional segregation of activity within the default-mode network, on the one hand, and control networks encompassing frontoparietal and cingulo-opercular areas on the other. Recent work, however, has suggested that in some cognitive control contexts nodes within the default-mode and control networks may actually cooperate to achieve optimal task performance. Here, we used functional magnetic resonance imaging to examine whether the ability to relate variables while solving a cognitive reasoning problem involves transient increases in connectivity between default-mode and control regions. Participants performed a modified version of the classic Wason selection task, in which the number of variables to be related is systematically varied across trials. As expected, areas within the default-mode network showed a parametric deactivation with increases in relational complexity, compared with neural activity in null trials. Critically, some of these areas also showed enhanced connectivity with task-positive control regions. Specifically, task-based connectivity between the striatum and the angular gyri, and between the thalamus and right temporal pole, increased as a function of relational complexity. These findings challenge the notion that functional segregation between regions within default-mode and control networks invariably support cognitive task performance, and reveal previously unknown roles for the striatum and thalamus in managing network dynamics during cognitive reasoning. © 2015 Wiley Periodicals, Inc.

Space-time evolution of whistler mode wave growth in the magnetosphere

International Nuclear Information System (INIS)

Carlson, C.R.; Helliwell, R.A.; Inan, U.S.

1990-01-01

A new model is developed to simulate the space-time evolution of a propagating coherent whistler mode wave pulse in the magnetosphere. The model is applied to the case of single frequency (2-6 kHz) wave pulses injected into the magnetosphere near L ≅ 4, using the VLF transmitting facility at Siple Station, Antarctica. The mechanism for growth is cyclotron resonance between the circularly polarized waves and the gyrating energetic electrons of the radiation belts. Application of this model reproduces observed exponential wave growth up to a saturated level. Additionally, the model predicts the observed initial linear increase in the output frequency versus time. This is the first time these features have been reproduced using applied wave intensities small enough to be consistent with satellite measurements. The center velocities of the electrons entering the wave pulse are selected in a way which maximizes the growth rate. The results show the importance of the transient aspects in the wave growth process. The growth established as the wave propagates toward the geomagnetic equator results in a spatially advancing wave phase structure due mainly to the geomagnetic inhomogeneity. Through the feedback of this radiation upon other electrons, conditions are established which result in a linearly increasing output frequency with time

Effects of friction and high torque on fatigue crack propagation in mode III

International Nuclear Information System (INIS)

Nayeb-Hashemi, H.; McClintock, F.A.; Ritchie, R.O.

1982-01-01

Turbo-generator and automotive shafts are often subjected to complex histories of high torques. To provide a basis for fatigue life estimation in such components, a study of fatigue crack propagation in Mode III (anti-plane shear) for a mill-annealed AISI 4140 steel (R /SUB B/ 88, 590 MN/m 2 tensile strength) has been undertaken, using torsionally-loaded, circumferentially-notched cylindrical specimens. As demonstrated previously for higher strength AISI 4340 steel, Mode III cyclic crack growth rates (dc/dN) /SUB III/ can be related to the alternating stress intensity factor ΔK /SUB III/ for conditions of small-scale yielding. However, to describe crack propagation behavior over an extended range of crack growth rates (about 10 -6 to 10 -2 mm per cycle), where crack growth proceeds under elastic-plastic and full plastic conditions, no correlation between (dc/dN) /SUB III/ and ΔK /SUB III/ is possible. Accordingly, a new parameter for torsional crack growth, termed the plastic strain intensity GAMMA /SUB III/, is introduced and is shown to provide a unique description of Mode III crack growth behavior for a wide range of testing conditions, provided a mean load reduces friction, abrasion, and interlocking between mating fracture surfaces A micro-mechanical model for the main radial Mode III growth is extended to high nominal stress levels, and predicts that Mode III fatigue crack propagation rates should be proportional to the range of plastic strain intensity (ΔGAMMA /SUB III/) if local Mode II growth rates are proportional to the displacements. Such predictions are shown to be in agreement with measured growth rates in AISI 4140 steel from 10 -6 to 10 -2 mm per cycle

Bifurcations of the normal modes of the Ne...Br{sub 2} complex

Energy Technology Data Exchange (ETDEWEB)

Blesa, Fernando [Departamento de Fisica Aplicada, Universidad de Zaragoza, Zaragoza (Spain); Mahecha, Jorge [Instituto de Fisica, Universidad de Antioquia, Medellin (Colombia); Salas, J. Pablo [Area de Fisica Aplicada, Universidad de La Rioja, Logrono (Spain); Inarrea, Manuel, E-mail: manuel.inarrea@unirioja.e [Area de Fisica Aplicada, Universidad de La Rioja, Logrono (Spain)

2009-12-28

We study the classical dynamics of the rare gas-dihalogen Ne...Br{sub 2} complex in its ground electronic state. By considering the dihalogen bond frozen at its equilibrium distance, the system has two degrees of freedom and its potential energy surface presents linear and T-shape isomers. We find the nonlinear normal modes of both isomers that determine the phase space structure of the system. By means of surfaces of section and applying the numerical continuation of families of periodic orbits, we detect and identify the different bifurcations suffered by the normal modes as a function of the system energy. Finally, using the Orthogonal Fast Lyapunov Indicator (OFLI), we study the evolution of the fraction of the phase space volume occupied by regular motions.

Constant-Distance Mode Nanospray Desorption Electrospray Ionization Mass Spectrometry Imaging of Biological Samples with Complex Topography

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Son N.; Liyu, Andrey V.; Chu, Rosalie K.; Anderton, Christopher R.; Laskin, Julia

2017-01-17

A new approach for constant distance mode mass spectrometry imaging of biological samples using nanospray desorption electrospray ionization (nano-DESI MSI) was developed by integrating a shear-force probe with nano-DESI probe. The technical concept and basic instrumental setup as well as general operation of the system are described. Mechanical dampening of resonant oscillations due to the presence of shear forces between the probe and the sample surface enables constant-distance imaging mode via a computer controlled closed feedback loop. The capability of simultaneous chemical and topographic imaging of complex biological samples is demonstrated using living Bacillus Subtilis ATCC 49760 colonies on agar plates. The constant-distance mode nano-DESI MSI enabled imaging of many metabolites including non-ribosomal peptides (surfactin, plipastatin and iturin) and iron-bound heme on the surface of living bacterial colonies ranging in diameter from 10 mm to 13 mm with height variations of up to 0.8 mm above the agar plate. Co-registration of ion images to topographic images provided higher-contrast images. Constant-mode nano-DESI MSI is ideally suited for imaging biological samples of complex topography in their native state.

Competitive cluster growth in complex networks.

Science.gov (United States)

Moreira, André A; Paula, Demétrius R; Costa Filho, Raimundo N; Andrade, José S

2006-06-01

In this work we propose an idealized model for competitive cluster growth in complex networks. Each cluster can be thought of as a fraction of a community that shares some common opinion. Our results show that the cluster size distribution depends on the particular choice for the topology of the network of contacts among the agents. As an application, we show that the cluster size distributions obtained when the growth process is performed on hierarchical networks, e.g., the Apollonian network, have a scaling form similar to what has been observed for the distribution of a number of votes in an electoral process. We suggest that this similarity may be due to the fact that social networks involved in the electoral process may also possess an underlining hierarchical structure.

Studies of new modes of radioactive decay by spontaneous emission of complex nuclei

International Nuclear Information System (INIS)

Barwick, S.W.; Hulet, E.K.; Moody, K.; Price, P.B.; Ravn, H.L.

1990-01-01

Impressive progress has been made in the two years since Rose and Jones first reported the novel spontaneous decay mode 223 Ra → 14 C + 209 Pb. Since then, the isotopes 222 Ra, 224 Ra, and 226 Ra have been observed to emit 14 C, and stringent upper limits have been set on branching ratios B( 14 C/α) for 221 Ra and 225 Ac. The discoveries of emission of 24 Ne from 232 U, and 231 Pa, and 233 U show that the phenomenon of heavy ion emission is a general one. A goal of recent experiments by the authors collaboration is to test models that differ by as much as 10 5 in predicted half-lives for the emission of complex nuclei with Z ≥ 12. Due to small branching ratios B approx-lt 10 -14 , and large fission background, they are developing new techniques to insure reliable identification of such rare decay modes. Experimental support for the unified models of alpha decay, complex nuclei emission, and spontaneous fission are addressed

Evaluation of crack growth behavior and probabilistic S–N characteristics of carburized Cr–Mn–Si steel with multiple failure modes

International Nuclear Information System (INIS)

Li, Wei; Sun, Zhenduo; Zhang, Zhenyu; Deng, Hailong; Sakai, Tatsuo

2014-01-01

Highlights: • The stepwise S–N characteristics only for interior induced failure was observed. • The interior crack growth behavior with threshold conditions in different stages was clarified. • The distribution characteristics of test data in transition failure region was evaluated. • A model for evaluating the probabilistic S–N curve with multiple failure modes was developed. - Abstract: The unexpected failures of case-hardened steels in long life regime have been a critical issue in modern engineering design. In this study, the failure behavior of a carburized Cr–Mn–Si steel under very high cycle fatigue (VHCF) was investigated, and a model for evaluating the probabilistic S–N curve associated with multiple failure modes was developed. Results show that the carburized Cr–Mn–Si steel exhibits three failure modes including the surface flaw-induced failure, the interior inclusion-induced failure without the fine granular area (FGA) and the interior inclusion-induced failure with the FGA. As the predominant failure mode in the VHCF regime, the interior failure process can be divided into four stages: (i) the small crack growth around the inclusion, (ii) the stable macroscopic crack growth outside the FGA, (iii) the unstable crack growth outside the fish-eye and (iv) the momentary fracture outside the final crack growth zone. The threshold values are successively evaluated to be 2.33 MPa m 1/2 , 4.13 MPa m 1/2 , 18.51 MPa m 1/2 and 29.26 MPa m 1/2 . The distribution characteristics of the test data in transition failure region can be well characterized by the mixed two-parameter Weibull distribution function. The developed probabilistic S–N curve model is in good agreement with the test data with multiple failure modes. Although the result is somewhat conservative in the VHCF regime, it is acceptable for safety considerations

Influence of competition and age on tree growth in structurally complex old-growth forests in northern Minnesota, USA

Science.gov (United States)

Tuomas Aakala; Shawn Fraver; Anthony W. D' Amato; Brian J. Palik

2013-01-01

Factors influencing tree growth in structurally complex forests remain poorly understood. Here we assessed the influence of competition on Pinus resinosa (n = 224) and Pinus strobus (n = 90) growth in four old-growth stands in Minnesota, using mixed effects models. A subset of trees, with...

Surface tearing modes in tokamaks

International Nuclear Information System (INIS)

Takizuka, Tomonori; Kurita, Gen-ichi; Azumi, Masafumi; Takeda, Tatsuoki

1985-10-01

Surface tearing modes in tokamaks are studied numerically and analytically. The eigenvalue problem is solved to obtain the growth rate and the mode structure. We investigate in detail dependences of the growth rate of the m/n = 2/1 resistive MHD modes on the safety factor at the plasma surface, current profile, wall position, and resistivity. The surface tearing mode moves the plasma surface even when the wall is close to the surface. The stability diagram for these modes is presented. (author)

Asymmetric modes and complex time eigenvalues of the one-speed neutron transport equation in a homogeneous sphere

International Nuclear Information System (INIS)

Paranjape, S.D.; Kumar, V.; Sahni, D.C.

1993-01-01

The one-speed, time-dependent, isotropically scattering, integral transport equation in a homogeneous sphere has been converted into a criticality-like problem by considering exponential time behaviour of the scalar flux. This criticality problem has been converted into a matrix eigenvalue problem using the Fourier transform technique. The time eigenvalues λ, which are complex in general, have been determined for spherically symmetric as well as asymmetric modes. For the former case, the real decay constants and the real parts of complex decay constants decrease monotonically with increasing system size and form two distinct families of single-valued functions. For the spherically asymmetric modes, certain new features emerge. The real decay constants are found to be multi-valued functions of system size and they do not always decrease monotonically with increasing system size. As the system size increases from zero onwards, the decay constants alternate between complex and real values and the real and complex decay constant curves interlace. (Author)

Effect of modes interaction on the resistive wall mode stability

International Nuclear Information System (INIS)

Chen Longxi; Wu Bin

2013-01-01

Effects of modes interaction on the resistive wall mode (RWM) stability are studied. When considering the modes interaction effects, the linear growth rate of the most unstable (3, 1) mode decreases. After linear evolution, the RWM saturates at the nonlinear phase. The saturation can be attributed to flux piling up on the resistive wall. When some modes exist, the (3, 1) mode saturates at lower level compared with single mode evolution. Meanwhile, the magnetic energy of the (5, 2) mode increases correspondingly, but the magnetic energy saturation level of the (2, 1) mode changes weakly. (authors)

Transverse multibunch modes for non-rigid bunches, including mode coupling

Energy Technology Data Exchange (ETDEWEB)

Berg, J S; Ruth, R D [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

1996-08-01

A method for computing transverse multibunch growth rates and frequency shifts in rings, which has been described previously, is applied to the PEP-II B factory. The method allows multibunch modes with different internal-bunch oscillation modes to couple to one another, similar to single-bunch mode coupling. Including coupling between the multibunch modes gives effects similar to those seen in single-bunch mode coupling. These effects occur at currents that are lower than the single-bunch mode coupling threshold. (author)

Structure of the Mr 140,000 growth hormone-dependent insulin-like growth factor binding protein complex: Determination by reconstitution and affinity-labeling

International Nuclear Information System (INIS)

Baxter, R.C.; Martin, J.L.

1989-01-01

To determine the structure of the high molecular weight, growth hormone-dependent complex between the insulin-like growth factors (IGF-I and IGF-II) and their binding proteins in human serum, we have reconstituted the complex from its purified component proteins and analyzed it by gel electrophoresis and autoradiography after covalent cross-linking. The proteins tested in reconstitution mixtures were an acid-labile Mr 84,000-86,000 glycoprotein doublet (alpha subunit), an acid-stable Mr 47,000-53,000 glycoprotein doublet with IGF-binding activity (BP-53 or beta subunit), and IGF-I or IGF-II (gamma subunit). In incubations containing any one of the three subunits 125I-labeled and the other two unlabeled, identical 125I-labeled alpha-beta-gamma complexes of Mr 140,000 were formed. Minor bands of Mr 120,000 and 90,000 were also seen, thought to represent a partially deglycosylated form of the alpha-beta-gamma complex, and an alpha-gamma complex arising as a cross-linking artifact. When serum samples from subjects of various growth hormone status were affinity-labeled with IGF-II tracer, a growth hormone-dependent Mr 140,000 band was seen, corresponding to the reconstituted alpha-beta-gamma complex. Other growth hormone-dependent labeled bands, of Mr 90,000 (corresponding to alpha-gamma), Mr 55,000-60,000 (corresponding to labeled beta-subunit doublet), and smaller bands of Mr 38,000, 28,000, and 23,000-25,000 (corresponding to labeled beta-subunit degradation products), were also seen in the affinity-labeled serum samples and in the complex reconstituted from pure proteins. All were immunoprecipitable with an anti-BP-53 antiserum. We conclude that the growth hormone-dependent Mr 140,000 IGF-binding protein complex in human serum has three components: the alpha (acid-labile) subunit, the beta (binding) subunit, and the gamma (growth factor) subunit

Effects of friction and high torque on fatigue crack propagation in Mode III

Science.gov (United States)

Nayeb-Hashemi, H.; McClintock, F. A.; Ritchie, R. O.

1982-12-01

Turbo-generator and automotive shafts are often subjected to complex histories of high torques. To provide a basis for fatigue life estimation in such components, a study of fatigue crack propagation in Mode III (anti-plane shear) for a mill-annealed AISI 4140 steel (RB88, 590 MN/m2 tensile strength) has been undertaken, using torsionally-loaded, circumferentially-notched cylindrical specimens. As demonstrated previously for higher strength AISI 4340 steel, Mode III cyclic crack growth rates (dc/dN) IIIcan be related to the alternating stress intensity factor ΔKIII for conditions of small-scale yielding. However, to describe crack propagation behavior over an extended range of crack growth rates (˜10-6 to 10-2 mm per cycle), where crack growth proceeds under elastic-plastic and full plastic conditions, no correlation between (dc/dN) III and ΔKIII is possible. Accordingly, a new parameter for torsional crack growth, termed the plastic strain intensity Γ III, is introduced and is shown to provide a unique description of Mode III crack growth behavior for a wide range of testing conditions, provided a mean load reduces friction, abrasion, and interlocking between mating fracture surfaces. The latter effect is found to be dependent upon the mode of applied loading (i.e., the presence of superimposed axial loads) and the crack length and torque level. Mechanistically, high-torque surfaces were transverse, macroscopically flat, and smeared. Lower torques showed additional axial cracks (longitudinal shear cracking) perpendicular to the main transverse surface. A micro-mechanical model for the main radi l Mode III growth, based on the premise that crack advance results from Mode II coalescence of microcracks initiated at inclusions ahead of the main crack front, is extended to high nominal stress levels, and predicts that Mode III fatigue crack propagation rates should be proportional to the range of plastic strain intensity (ΔΓIII if local Mode II growth rates are

Distinct growth of the nasomaxillary complex in Au. sediba.

Science.gov (United States)

Lacruz, Rodrigo S; Bromage, Timothy G; O'Higgins, Paul; Toro-Ibacache, Viviana; Warshaw, Johanna; Berger, Lee R

2015-10-15

Studies of facial ontogeny in immature hominins have contributed significantly to understanding the evolution of human growth and development. The recently discovered hominin species Autralopithecus sediba is represented by a well-preserved and nearly complete facial skeleton of a juvenile (MH1) which shows a derived facial anatomy. We examined MH1 using high radiation synchrotron to interpret features of the oronasal complex pertinent to facial growth. We also analyzed bone surface microanatomy to identify and map fields of bone deposition and bone resorption, which affect the development of the facial skeleton. The oronasal anatomy (premaxilla-palate-vomer architecture) is similar to other Australopithecus species. However surface growth remodeling of the midface (nasomaxillary complex) differs markedly from Australopithecus, Paranthropus, early Homo and from KNM-WT 15000 (H. erectus/ergaster) showing a distinct distribution of vertically disposed alternating depository and resorptive fields in relation to anterior dental roots and the subnasal region. The ontogeny of the MH1 midface superficially resembles some H. sapiens in the distribution of remodeling fields. The facial growth of MH1 appears unique among early hominins representing an evolutionary modification in facial ontogeny at 1.9 my, or to changes in masticatory system loading associated with diet.

Band offsets and growth mode of molecular beam epitaxy grown MgO (111) on GaN (0002) by x-ray photoelectron spectroscopy

Science.gov (United States)

Craft, H. S.; Collazo, R.; Losego, M. D.; Mita, S.; Sitar, Z.; Maria, J.-P.

2007-10-01

MgO is a proposed dielectric for use as a tunneling barrier in devices integrating GaN and ferroelectric oxides. In this study, we present data regarding the growth mode and band offsets of MgO grown epitaxially on GaN (0002) surfaces using molecular beam epitaxy. Using in situ x-ray photoelectron spectroscopy (XPS) and molecular beam epitaxy, we determine, from sequential growth experiments, that the growth of MgO proceeds via the Volmer-Weber (three-dimensional) mode, and full coalescence of the film does not occur until approximately 12nm of MgO has been deposited. The observation of a three-dimensional growth mode is in agreement with previously published data. For the valence band offset, we find a value of 1.2±0.2eV, which corresponds to a 3.2eV conduction band offset. XPS measurements suggest a chemically abrupt interface and no effect on band lineup due to the slow coalescence behavior.

Band offsets and growth mode of molecular beam epitaxy grown MgO (111) on GaN (0002) by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Craft, H. S.; Collazo, R.; Losego, M. D.; Mita, S.; Sitar, Z.; Maria, J.-P.

2007-01-01

MgO is a proposed dielectric for use as a tunneling barrier in devices integrating GaN and ferroelectric oxides. In this study, we present data regarding the growth mode and band offsets of MgO grown epitaxially on GaN (0002) surfaces using molecular beam epitaxy. Using in situ x-ray photoelectron spectroscopy (XPS) and molecular beam epitaxy, we determine, from sequential growth experiments, that the growth of MgO proceeds via the Volmer-Weber (three-dimensional) mode, and full coalescence of the film does not occur until approximately 12 nm of MgO has been deposited. The observation of a three-dimensional growth mode is in agreement with previously published data. For the valence band offset, we find a value of 1.2±0.2 eV, which corresponds to a 3.2 eV conduction band offset. XPS measurements suggest a chemically abrupt interface and no effect on band lineup due to the slow coalescence behavior

New Modeling of Steady-State Modes of Complex Electrical Grids of Power Systems

Directory of Open Access Journals (Sweden)

Akhmetbayev Arman

2018-01-01

Full Text Available Classical methods for modeling the steady-state modes of complex electrical networks and systems are based on the application of nonlinear node equations. Nonlinear equations are solved by iterative methods, which are connected by known difficulties. To a certain extent, these difficulties can be weakened by applying topological methods. In this paper, we outline the theoretical foundations for the formation of the inverse form of nodal stress equations based on the topology of electrical networks and systems. A new topological method for calculating the distribution coefficients of node currents is proposed based on all possible trees of a directed graph of a complex electrical network. A complex program for calculating current distribution coefficients and forming steady-state parameters in the MATLAB environment has been developed.

Molecular phylogenetics of Echinopsis (Cactaceae): Polyphyly at all levels and convergent evolution of pollination modes and growth forms.

Science.gov (United States)

Schlumpberger, Boris O; Renner, Susanne S

2012-08-01

In its current circumscription, Echinopsis with 100-150 species is one of the largest and morphologically most diverse genera of Cactaceae. This diversity and an absence of correlated characters have resulted in numerous attempts to subdivide Echinopsis into more homogeneous subgroups. To infer natural species groups in this alliance, we here provide a plastid phylogeny and use it to infer changes in growth form, pollination mode, and ploidy level. We sequenced 3800 nucleotides of chloroplast DNA from 162 plants representing 144 species and subspecies. The sample includes the type species of all genera close to, or included in, Echinopsis as well as a dense sample of other genera of the Trichocereeae and further outgroups. New and published chromosome counts were compiled and traced on the phylogeny, as were pollination modes and growth habits. A maximum likelihood phylogeny confirms that Echinopsis s.l. is not monophyletic nor are any of the previously recognized genera that have more than one species. Pollination mode and, to a lesser extent, growth habit are evolutionarily labile, and diploidy is the rule in Echinopsis s.l., with the few polyploids clustered in just a few clades. The use of evolutionary labile floral traits and growth habit has led to nonnatural classifications. Taxonomic realignments are required, but further study of less evolutionary labile traits suitable for circumscribing genera are needed. Surprisingly, polyploidy seems infrequent in the Echinopsis alliance and hybridization may thus be of minor relevance in the evolution of this clade.

Operation modes research of liquefied natural gas storages as a part of the ground complexes equipment

Directory of Open Access Journals (Sweden)

N. S. Korolev

2014-01-01

Full Text Available The use of the Liquefied Natural Gas (LNG in the space-rocket equipment is motivated by some advantages. That is why a lot of tests and works are actively carried out now on rocket engines using liquefied natural gas.To provide the engine tests and subsequent rocket complex operation a creation of LNG storages is demanded as a part of ground processing equipment and support for their safe operation conditions.One of LNG danger factor is its low boiling temperature, and also changing the condition, density and LNG boiling temperature at storage due to evaporation of light component, namely methane. At refill of the storages having fuel remains with a new LNG portion these factors can lead to formation of the stratified macro-layers and cause a mode of the intensive mixing that is called "rollover", with almost instant evaporation of LNG big mass and sharp pressure boost, capable to result in the storage distraction with catastrophic effects.The work objectives are formulated such as a technique development for forecasting of the LNG parameters in operating storages including the rollover mode, a comparison of calculated results of the LNG parameters with the experimental data, and a definition of possible recommendations for safe operation of LNG storages as a part of the ground complexes equipment.The paper reviews 12 publications concerning the issues and proceeding processes at operation of LNG storages, including the rollover mode.To verify the reliability of process simulation results in the LNG, represented in models by the binary methane-ethane mixture the calculated values have been compared with the experimental data for a LNG storage mode in the reservoir of a ground test complex.The reliability of developed models of the heat-mass-exchange processes in stratified on density and temperature in LNG storage with emergence of conditions for the rollover mode has been verified by comparing the settlement characteristics to the published

Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system

International Nuclear Information System (INIS)

Knauer, J.P.; Verdon, C.P.; Meyerhofer, D.D.; Boehly, T.R.; Bradley, D.K.; Smalyuk, V.A.; Ofer, D.; McKenty, P.W.; Glendinning, S.G.; Kalantar, D.H.; Watt, R.G.; Gobby, P.L.; Willi, O.; Taylor, R.J.

1997-01-01

The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5x10 14 W/cm 2 . Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%endash 7% over a 600-μm-diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-μm and 60-μm wavelength perturbations was found to be in good agreement with ORCHID simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-μm-thick polystyrene foam buffer layer resulted in reduced growth of the 31-μm perturbation and essentially unchanged growth for the 60-μm case when compared to targets without foam. copyright 1997 American Institute of Physics

Rock Fracture Toughness Study Under Mixed Mode I/III Loading

Science.gov (United States)

Aliha, M. R. M.; Bahmani, A.

2017-07-01

Fracture growth in underground rock structures occurs under complex stress states, which typically include the in- and out-of-plane sliding deformation of jointed rock masses before catastrophic failure. However, the lack of a comprehensive theoretical and experimental fracture toughness study for rocks under contributions of out-of plane deformations (i.e. mode III) is one of the shortcomings of this field. Therefore, in this research the mixed mode I/III fracture toughness of a typical rock material is investigated experimentally by means of a novel cracked disc specimen subjected to bend loading. It was shown that the specimen can provide full combinations of modes I and III and consequently a complete set of mixed mode I/III fracture toughness data were determined for the tested marble rock. By moving from pure mode I towards pure mode III, fracture load was increased; however, the corresponding fracture toughness value became smaller. The obtained experimental fracture toughness results were finally predicted using theoretical and empirical fracture models.

Complexity reduction in the H.264/AVC using highly adaptive fast mode decision based on macroblock motion activity

Science.gov (United States)

Abdellah, Skoudarli; Mokhtar, Nibouche; Amina, Serir

2015-11-01

The H.264/AVC video coding standard is used in a wide range of applications from video conferencing to high-definition television according to its high compression efficiency. This efficiency is mainly acquired from the newly allowed prediction schemes including variable block modes. However, these schemes require a high complexity to select the optimal mode. Consequently, complexity reduction in the H.264/AVC encoder has recently become a very challenging task in the video compression domain, especially when implementing the encoder in real-time applications. Fast mode decision algorithms play an important role in reducing the overall complexity of the encoder. In this paper, we propose an adaptive fast intermode algorithm based on motion activity, temporal stationarity, and spatial homogeneity. This algorithm predicts the motion activity of the current macroblock from its neighboring blocks and identifies temporal stationary regions and spatially homogeneous regions using adaptive threshold values based on content video features. Extensive experimental work has been done in high profile, and results show that the proposed source-coding algorithm effectively reduces the computational complexity by 53.18% on average compared with the reference software encoder, while maintaining the high-coding efficiency of H.264/AVC by incurring only 0.097 dB in total peak signal-to-noise ratio and 0.228% increment on the total bit rate.

Interaction Mode between Inclusion Complex of Vitamin K3 with γ- Cyclodextrin and Herring-Sperm DNA.

Science.gov (United States)

Tang, Yan; Cai, Li; Xue, Kang; Wang, Chunling; Xiong, Xiaoli

2016-05-03

Methods including spectroscopy, electronic chemistry and thermodynamics were used to study the inclusion effect between γ-cyclodextrin (CD) and vitamin K3(K3), as well as the interaction mode between herring-sperm DNA (hsDNA) and γ-CD-K3 inclusion complex. The results from ultraviolet spectroscopic method indicated that VK3 and γ-CD formed 1:1 inclusion complex, with the inclusion constant Kf = 1.02 × 10(4) L/mol, which is based on Benesi-Hildebrand's viewpoint. The outcomes from the probe method and Scatchard methods suggested that the interaction mode between γ-CD-K3 and DNA was a mixture mode, which included intercalation and electrostatic binding effects. The binding constants were K (θ)25°C = 2.16 × 10(4) L/mol, and K(θ)37°C = 1.06 × 10(4) L/mol. The thermodynamic functions of the interaction between γ-CD-K3 and DNA were ΔrHm(θ) = -2.74 × 10(4) J/mol, ΔrSm(θ) = 174.74 J·mol(-1)K(-1), therefore, both ΔrHm(θ) (enthalpy) and ΔrSm(θ) (entropy) worked as driven forces in this action.

Crystallization of Mitochondrial Respiratory Complex II fromChicken Heart: A Membrane-Protein Complex Diffracting to 2.0Angstrom

Energy Technology Data Exchange (ETDEWEB)

Huang, Li-shar; Borders, Toni M.; Shen, John T.; Wang, Chung-Jen; Berry, Edward A.

2004-12-17

Procedure is presented for preparation of diffraction-quality crystals of a vertebrate mitochondrial respiratory Complex II. The crystals have the potential to diffract to at least 2.0 Angstrom with optimization of post-crystal-growth treatment and cryoprotection. This should allow determination of the structure of this important and medically relevant membrane protein complex at near-atomic resolution and provide great detail of the mode of binding of substrates and inhibitors at the two substrate-binding sites.

EFFECT OF COMPLEX ORGANIC COMPOUNDS ON GROWTH PLANLET OF DENDROBIUM ORCHID

Directory of Open Access Journals (Sweden)

Sitti Raodah Garuda

2015-01-01

Full Text Available Uniqueness of stunning Dendrobium variety such as shapes, colors, and sizes are main attraction of this plant. Germination oforchid seeds can be carried out in a laboratory with in vitro techniques.Medium used for germination of orchid seeds are Vacin and Went medium. Researcher stried to add other substances that may increase growth explants, such as complex organic compounds. Study aims to determine effect of complex organic compounds into growth medium VW Dendrobium plantlets. Research used complete randomized design consist five treatment:VW medium without extract (control, VW medium+banana extract, VW medium+ melon extrac, VW medium+guava extract and VW medium+pepaya extract, with three replications, each replication consist two culture bottles.. Each culture bottle planted four planlets. Addition of complex organic compounds such as melon extract gave best vegetative growth of leaves quantity, roots quantity, root length and fresh weight. While guava extract provide best results to plantlet high and saplings. Plant lets with melon extract treatment showed appearance of muscular orchid plantlets is characteristic of plants that can survive during acclimatization. While both guava extract is best used for purpose of orchid plantlets regeneration.

Mixed-Mode Oscillations in Complex-Plasma Instabilities

International Nuclear Information System (INIS)

Mikikian, Maxime; Cavarroc, Marjorie; Coueedel, Lenaiec; Tessier, Yves; Boufendi, Laiefa

2008-01-01

Instabilities in dusty plasmas are frequent phenomena. We show that some instabilities can be described by mixed-mode oscillations often encountered in chemical systems or neuronal dynamics and studied through dynamical system theories. The time evolution of these instabilities is studied through the change in the associated waveform. Frequency and interspike interval are analyzed and compared to results obtained in other scientific fields concerned by mixed-mode oscillations

Polarity control and growth mode of InN on yttria-stabilized zirconia (111) surfaces

International Nuclear Information System (INIS)

Kobayashi, Atsushi; Okubo, Kana; Ohta, Jitsuo; Oshima, Masaharu; Fujioka, Hiroshi

2012-01-01

We have found that polarity of epitaxial InN layers has been controlled by choice of a capping material during high-temperature annealing of yttria-stabilized zirconia (YSZ) (111) substrates in air. Angle-resolved X-ray photoelectron spectroscopy has revealed that the amount of segregation of Y atoms to the YSZ surface depended on the capping material of the substrates. In-polar and N-polar InN have been reproducibly grown on Y-segregated and Y-segregation-free YSZ surfaces, respectively. We have also found that the growth of the first monolayer (ML) of N-polar InN proceeds in a step-flow mode which then switches to layer-by-layer mode after the coverage by 1-ML-thick InN. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

A pragmatic approach to including complex natural modes of vibration in aeroelastic analysis

CSIR Research Space (South Africa)

Van Zyl, Lourens H

2015-09-01

Full Text Available complex natural modes of vibration in aeroelastic analysis Louw van Zyl International Aerospace Symposium of South Africa 14 to 16 September, 2015 Stellenbosch, South Africa Slide 2 © CSIR 2006 www.csir.co.za Problem statement..., the square of the angular frequencies in radians per second) [ ]{ } [ ]{ } [ ]{ } { }fxKxCxM =++ &&& [ ]{ } [ ]{ } 0=+ xKxMs2 Slide 4 © CSIR 2006 www.csir.co.za Structural Dynamics (continued) • The corresponding eigenvectors are real...

Reconstruction of a metabolic regulatory network in Escherichia coli for purposeful switching from cell growth mode to production mode in direct GABA fermentation from glucose.

Science.gov (United States)

Soma, Yuki; Fujiwara, Yuri; Nakagawa, Takuya; Tsuruno, Keigo; Hanai, Taizo

2017-09-01

γ-aminobutyric acid (GABA) is a drug and functional food additive and is used as a monomer for producing the biodegradable plastic, polyamide 4. Recently, direct GABA fermentation from glucose has been developed as an alternative to glutamate-based whole cell bioconversion. Although total productivity in fermentation is determined by the specific productivity and cell amount responsible for GABA production, the optimal metabolic state for GABA production conflicts with that for bacterial cell growth. Herein, we demonstrated metabolic state switching from the cell growth mode based on the metabolic pathways of the wild type strain to a GABA production mode based on a synthetic metabolic pathway in Escherichia coli through rewriting of the metabolic regulatory network and pathway engineering. The GABA production mode was achieved by multiple strategies such as conditional interruption of the TCA and glyoxylate cycles, engineering of GABA production pathway including a bypass for precursor metabolite supply, and upregulation of GABA transporter. As a result, we achieved 3-fold improvement in total GABA production titer and yield (4.8g/L, 49.2% (mol/mol glucose)) in batch fermentation compared to the case without metabolic state switching (1.6g/L, 16.4% (mol/mol glucose)). This study reports the highest GABA production performance among previous reports on GABA fermentation from glucose using engineered E. coli. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Combined effect of viscosity and vorticity on single mode Rayleigh-Taylor instability bubble growth

International Nuclear Information System (INIS)

Banerjee, Rahul; Mandal, Labakanta; Roy, S.; Khan, M.; Gupta, M. R.

2011-01-01

The combined effect of viscosity and vorticity on the growth rate of the bubble associated with single mode Rayleigh-Taylor instability is investigated. It is shown that the effect of viscosity on the motion of the lighter fluid associated with vorticity accumulated inside the bubble due to mass ablation may be such as to reduce the net viscous drag on the bubble exerted by the upper heavier fluid as the former rises through it.

Long timescale plasma dynamics and explosive growth driven by the double tearing mode in reversed shear plasmas

International Nuclear Information System (INIS)

Ishii, Y.; Azumi, M.; Kishimoto, Y.; Leboeuf, J.N.

2003-01-01

A new nonlinear destabilization process is found in the nonlinear phase of the double tearing mode (DTM) by using reduced MHD equations with helical symmetry. The nonlinear destabilization causes the abrupt growth of the DTM and subsequent collapse after long timescale evolution in the Rutherford-type regime. The nonlinear growth of the DTM is suddenly triggered, when the triangular deformation of magnetic islands with a sharp current point at the X-point around the outer rational surface exceeds a certain value. Decreasing the resistivity increases the sharpness of the triangularity and the spontaneous growth rate in the abrupt growth phase is almost independent of the resistivity. Current point formation is also confirmed in multi-helicity simulations, where the magnetic fields become stochastic between two rational surfaces. (author)

Nonlinear drift tearing mode. Strong mode of excitation and stabilization mechanisms

International Nuclear Information System (INIS)

Galeev, A.A.; Zelenyj, L.M.; Kuznetsova, M.M.

1985-01-01

A nonlinear theory of magnetic disturbance development in collisionless configurations with magnetic field shear is considered. The instability evolution is investigated with account for the dynamics of ions and potential electric fields which determine the mode stabilization. It has been found that the drift tearing mode possesses metastable properties: in a nonlinear mode even the growth of linearly stable disturbances of the finite amplitude is possible

Interaction of tearing modes

International Nuclear Information System (INIS)

Satya, Y.; Schmidt, G.

1979-01-01

A fully developed tearing mode modifies the magnetic field profile. The effect of this profile modification on the linear growth rate of a different tearing mode in a slab and cylindrical geometry is investigated

Investigations on Substrate Temperature-Induced Growth Modes of Organic Semiconductors at Dielectric/semiconductor Interface and Their Correlation with Threshold Voltage Stability in Organic Field-Effect Transistors.

Science.gov (United States)

Padma, Narayanan; Maheshwari, Priya; Bhattacharya, Debarati; Tokas, Raj B; Sen, Shashwati; Honda, Yoshihide; Basu, Saibal; Pujari, Pradeep Kumar; Rao, T V Chandrasekhar

2016-02-10

Influence of substrate temperature on growth modes of copper phthalocyanine (CuPc) thin films at the dielectric/semiconductor interface in organic field effect transistors (OFETs) is investigated. Atomic force microscopy (AFM) imaging at the interface reveals a change from 'layer+island' to "island" growth mode with increasing substrate temperatures, further confirmed by probing the buried interfaces using X-ray reflectivity (XRR) and positron annihilation spectroscopic (PAS) techniques. PAS depth profiling provides insight into the details of molecular ordering while positron lifetime measurements reveal the difference in packing modes of CuPc molecules at the interface. XRR measurements show systematic increase in interface width and electron density correlating well with the change from layer + island to coalesced huge 3D islands at higher substrate temperatures. Study demonstrates the usefulness of XRR and PAS techniques to study growth modes at buried interfaces and reveals the influence of growth modes of semiconductor at the interface on hole and electron trap concentrations individually, thereby affecting hysteresis and threshold voltage stability. Minimum hole trapping is correlated to near layer by layer formation close to the interface at 100 °C and maximum to the island formation with large voids between the grains at 225 °C.

Growth performance, innate immune responses and disease resistance of fingerling blunt snout bream, Megalobrama amblycephala adapted to different berberine-dietary feeding modes.

Science.gov (United States)

Xu, Wei-Na; Chen, Dan-Hong; Chen, Qing-Qing; Liu, Wen-Bin

2017-09-01

A 8-week feeding trial was conducted to evaluate the effect of different berberine-dietary feeding modes on growth, non-specific immune responses and disease resistance of blunt snout bream, Megalobrama amblycephala. Fish (average initial weight 4.70 ± 0.02 g) were fed two fat levels (5% and 10%) diets in three berberine-feeding modes (supplementing 50 mg/kg berberine continuously, two-week or four-week intervals) with four replicates, respectively. Then, fish were challenged by Aeromonas hydrophila and mortality was recorded for the next 96 h after feeding trial. The results showed that different feeding modes of berberine significantly influenced growth, innate immunity and antioxidant capability of fish. Fish fed normal diet with 50 mg/kg berberine at two-week interval mode reflected remarkably (P complement component 3 (C3) and complement component 4 (C4) concentrations were significantly (P feeding modes. Based on fish healthy improvement and feeding cost saving, blunt snout bream fed normal diet with 50 mg/kg berberine at two-week interval or fed high-fat diet with berberine at two-week or four-week intervals were optimal feeding mode, respectively. Copyright © 2017. Published by Elsevier Ltd.

Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

Directory of Open Access Journals (Sweden)

Bodee Nutho

2014-11-01

Full Text Available In the present study, our aim is to investigate the preferential binding mode and encapsulation of the flavonoid fisetin in the nano-pore of β-cyclodextrin (β-CD at the molecular level using various theoretical approaches: molecular docking, molecular dynamics (MD simulations and binding free energy calculations. The molecular docking suggested four possible fisetin orientations in the cavity through its chromone or phenyl ring with two different geometries of fisetin due to the rotatable bond between the two rings. From the multiple MD results, the phenyl ring of fisetin favours its inclusion into the β-CD cavity, whilst less binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system.

Final hazard classification and auditable safety analysis for the 308 Building Complex during post-deactivation surveillance and maintenance mode

International Nuclear Information System (INIS)

Dexheimer, D.

1996-11-01

This document summarizes the inventories of radioactive and hazardous materials present within the 308 Building Complex, and presents the hazard evaluation methodology used to prepare the hazard classification for the Complex. The complex includes the 308 Building (process area and office facilities) and the 308 Building Annex, which includes the former Neutron Radiography Facility containing a shutdown (and partially decommissioned) reactor. This document applies to the post-deactivation surveillance and maintenance mode only, and provides an authorization basis limited to surveillance and maintenance activities. This document does not authorize decommissioning and decontamination activities, movement of fissile materials, modification to facility confinement structures, nor the introduction or storage of additional radionuclides in the 308 Building Complex. This document established a final hazard classification and identifies appropriate and adequate safety functions and controls to reduce or mitigate the risk associated with the surveillance and maintenance mode. The most consequential hazard event scenario is a postulated unmitigated release from an earthquake event involving the entire complex. That release is equivalent to 30% of the Nuclear Category 3 threshold adjusted as allowed by DOE-STD-1027-92 (DOE 1992). The dominant isotopes are 239 Pu, 240 Pu, and 241 Am in the gloveboxes

Kink and tearing mode instabilities in a tokamak

International Nuclear Information System (INIS)

Pogutse, O.P.

The continuous transition from a free-boundary-kink mode to a tearing mode in a current carrying plasma column is investigated. It is shown that in the real experimental situation, even for high temperatures in the plasma periphery, the kink mode exists due to electron inertia, the growth rate of the instability being at least a few times smaller than the growth rate with a free boundary. We find the dispersion relation allowing us to calculate the growth rate for plasma parameters of physical interest. It is shown that as the size of the current channel increases the growth rate falls, but the range of values of the safety factor where the mode is unstable broadens

Energy of auroral electrons and Z mode generation

Science.gov (United States)

Krauss-Varban, D.; Wong, H. K.

1990-01-01

The present consideration of Z-mode radiation generation, in light of observational results indicating that the O mode and second-harmonic X-mode emissions can prevail over the X-mode fundamental radiation when suprathermal electron energy is low, gives attention to whether the thermal effect on the Z-mode dispersion can be equally important, and whether the Z-mode can compete for the available free-energy source. It is found that, under suitable circumstances, the growth rate of the Z-mode can be substantial even for low suprathermal auroral electron energies. Growth is generally maximized for propagation perpendicular to the magnetic field.

Effect of the resistive wall on the growth rate of weakly unstable external kink mode in general 3D configurations

International Nuclear Information System (INIS)

Chu, M.S.; Ichiguchi, K.

2005-05-01

Formation of a method for the systematic computation of the growth rate of the weakly unstable RWM in 3D configurations by using results from ideal stability codes is presented. It is shown that the growth rate of the RWM is approximately given by the rate at which the available free energy for the ideal external kink mode can be dissipated by the resistive wall. The eigenfunction is also approximated by that of the external kink mode. This formulation is demonstrated by coupling to the ideal MHD code KSTEP with computation of the dissipation on the resistive wall. Results of the stability of the RWM in LHD plasmas and discussion on the validity and improvement to the computation are also included. (author)

Complexity growth rates for AdS black holes in massive gravity and f(R) gravity

Energy Technology Data Exchange (ETDEWEB)

Guo, Wen-Di; Wei, Shao-Wen; Li, Yan-Yan; Liu, Yu-Xiao [Lanzhou University, Institute of Theoretical Physics, Lanzhou (China)

2017-12-15

The ''complexity = action'' duality states that the quantum complexity is equal to the action of the stationary AdS black hole within the Wheeler-DeWitt patch at late time approximation. We compute the action growth rates of the neutral and charged black holes in massive gravity and the neutral, charged and Kerr-Newman black holes in f(R) gravity to test this conjecture. Besides, we investigate the effects of the massive graviton terms, higher derivative terms and the topology of the black hole horizon on the complexity growth rate. (orig.)

The energy spectrum of electromagnetic normal modes in dissipative media: modes between two metal half spaces

International Nuclear Information System (INIS)

Sernelius, Bo E

2008-01-01

The energy spectrum of electromagnetic normal modes plays a central role in the theory of the van der Waals and Casimir interaction. Here we study the modes in connection with the van der Waals interaction between two metal half spaces. Neglecting dissipation leads to distinct normal modes with real-valued frequencies. Including dissipation seems to have the effect that these distinct modes move away from the real axis into the complex frequency plane. The summation of the zero-point energies of these modes render a complex-valued result. Using the contour integration, resulting from the use of the generalized argument principle, gives a real-valued and different result. We resolve this contradiction and show that the spectrum of true normal modes forms a continuum with real frequencies

The effect of pH and storage on copper speciation and bacterial growth in complex growth media

DEFF Research Database (Denmark)

Hasman, Henrik; Bjerrum, Morten J.; Christiansen, Lasse Engbo

2009-01-01

correlation between the free copper concentration and bacterial growth, than for the total copper concentration and growth. Furthermore, it is shown that the initial pH influences the amount of free copper ions in the media and that this has a direct effect on the ability of bacterial cultures to grow......In this paper we examine how the bacterial growth is influenced by the availability of copper ions in complex Mueller Hinton growth media. The data shows that the free copper concentration is seven to eight orders of magnitude lower the total copper concentration and that there seems to be a better....... However, there still remains an effect of pH on bacterial growth which cannot be attributed to the influence of the Cu2+ concentration alone. The study also shows that the sterilization treatment can have some effect on the availability of copper ions in the media over time. Freshly autoclaved and sterile...

Identification of a liver growth factor as an albumin-bilirubin complex.

OpenAIRE

Díaz-Gil, J J; Gavilanes, J G; Sánchez, G; García-Cañero, R; García-Segura, J M; Santamaría, L; Trilla, C; Escartín, P

1987-01-01

We have reported the purification and characterization of a protein that behaves as a liver growth factor, showing activity either in vivo or in vitro [Díaz-Gil et al. (1986) Biochem. J. 235, 49-55]. In the present paper, we identify this liver growth factor (LGF) as an albumin-bilirubin complex. This conclusion is supported by the results of chemical and spectroscopic characterization of this protein as well as by experiments in vivo. Incubation of albumin isolated from normal rats with bili...

Tearing modes with pressure gradient effect in pair plasmas

International Nuclear Information System (INIS)

Cai Huishan; Li Ding; Zheng Jian

2009-01-01

The general dispersion relation of tearing mode with pressure gradient effect in pair plasmas is derived analytically. If the pressure gradients of positron and electron are not identical in pair plasmas, the pressure gradient has significant influence at tearing mode in both collisionless and collisional regimes. In collisionless regime, the effects of pressure gradient depend on its magnitude. For small pressure gradient, the growth rate of tearing mode is enhanced by pressure gradient. For large pressure gradient, the growth rate is reduced by pressure gradient. The tearing mode can even be stabilized if pressure gradient is large enough. In collisional regime, the growth rate of tearing mode is reduced by the pressure gradient. While the positron and electron have equal pressure gradient, tearing mode is not affected by pressure gradient in pair plasmas.

Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system

International Nuclear Information System (INIS)

Knauer, J. P.; Betti, R.; Bradley, D. K.; Boehly, T. R.; Collins, T. J. B.; Goncharov, V. N.; McKenty, P. W.; Meyerhofer, D. D.; Smalyuk, V. A.; Verdon, C. P.

2000-01-01

The results from a series of single-mode, Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five or six 351 nm laser beams overlapped with total intensities up to 2.5x10 14 W/cm 2 . Experiments were performed with both 3 ns ramp and 3 ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600 μm diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using throughfoil radiography and was detected with an x-ray framing camera for CH targets. Two-dimensional (2-D) hydrodynamic simulations (ORCHID) [R. L. McCrory and C. P. Verdon, in Inertial Confinement Fusion (Editrice Compositori, Bologna, 1989), pp. 83-124] of the growth of 20, 31, and 60 μm wavelength perturbations were in good agreement with the experimental data when the experimental details, including noise, were included. The amplitude of the simulation optical depth is in good agreement with the experimental optical depth; therefore, great care must be taken when the growth rates are compared to dispersion formulas. Since the foil's initial condition just before it is accelerated is not that of a uniformly compressed foil, the optical density measurement does not accurately reflect the amplitude of the ablation surface but is affected by the initial nonuniform density profile. (c) 2000 American Institute of Physics

Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system

Energy Technology Data Exchange (ETDEWEB)

Knauer, J. P. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Bradley, D. K. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Boehly, T. R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Collins, T. J. B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Goncharov, V. N. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); McKenty, P. W. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Smalyuk, V. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Verdon, C. P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] (and others)

2000-01-01

The results from a series of single-mode, Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five or six 351 nm laser beams overlapped with total intensities up to 2.5x10{sup 14} W/cm{sup 2}. Experiments were performed with both 3 ns ramp and 3 ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600 {mu}m diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using throughfoil radiography and was detected with an x-ray framing camera for CH targets. Two-dimensional (2-D) hydrodynamic simulations (ORCHID) [R. L. McCrory and C. P. Verdon, in Inertial Confinement Fusion (Editrice Compositori, Bologna, 1989), pp. 83-124] of the growth of 20, 31, and 60 {mu}m wavelength perturbations were in good agreement with the experimental data when the experimental details, including noise, were included. The amplitude of the simulation optical depth is in good agreement with the experimental optical depth; therefore, great care must be taken when the growth rates are compared to dispersion formulas. Since the foil's initial condition just before it is accelerated is not that of a uniformly compressed foil, the optical density measurement does not accurately reflect the amplitude of the ablation surface but is affected by the initial nonuniform density profile. (c) 2000 American Institute of Physics.

Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

OpenAIRE

Muliar, Olena; Usuga Castaneda, Mario A.; Rottwitt, Karsten; Lægsgaard, Jesper

2015-01-01

The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength or optical modes. Mode division multiplexing (MDM) appears in this context as a promising and viable solution for such capacity increase, since it utilizes multiple spatial modes of an optical fiber as indi...

MHD simulation of high wavenumber ballooning-like modes in LHD

International Nuclear Information System (INIS)

Miura, H.; Nakajima, N.

2008-10-01

Dynamical growths of high-wavenumber ballooning modes are studied through full-3D nonlinear MHD simulations of the Large Helical Device. The growths of the ballooning modes are identified by studying the growth rates and the radial profiles of the Fourier coefficients of fluctuation variables. The mechanisms to weaken the growth of instability, such as the local fattening of the pressure and the energy release to the parallel kinetic energy, are found being insufficient to suppress the high-wavenumber ballooning modes. Consequently, the mean pressure profile is totally modified when the evolutions of the ballooning modes are saturated. The numerical results reveal that we need some mechanisms which do not originate from an ideal MHD to achieve a mild, saturated behaviors beyond the growths of unstable high ballooning modes in the helical device. The parallel heat conductivity is proposed as one of possible non-ideal mechanisms. (author)

Student Reading Growth Illuminates the Common Core Text-Complexity Standard: Raising Both Bars

Science.gov (United States)

Williamson, Gary L.; Fitzgerald, Jill; Stenner, Jackson A.

2014-01-01

The Common Core State Standards (CCSS) establish a challenging text-complexity standard for all high school graduates to read at college and workplace text-complexity levels. We argue that implementation of the CCSS standard requires concurrent examination of historical student reading-growth trends. An example of a historical student average…

An Abrupt Transition to an Intergranular Failure Mode in the Near-Threshold Fatigue Crack Growth Regime in Ni-Based Superalloys

Science.gov (United States)

Telesman, J.; Smith, T. M.; Gabb, T. P.; Ring, A. J.

2018-06-01

Cyclic near-threshold fatigue crack growth (FCG) behavior of two disk superalloys was evaluated and was shown to exhibit an unexpected sudden failure mode transition from a mostly transgranular failure mode at higher stress intensity factor ranges to an almost completely intergranular failure mode in the threshold regime. The change in failure modes was associated with a crossover of FCG resistance curves in which the conditions that produced higher FCG rates in the Paris regime resulted in lower FCG rates and increased ΔK th values in the threshold region. High-resolution scanning and transmission electron microscopy were used to carefully characterize the crack tips at these near-threshold conditions. Formation of stable Al-oxide followed by Cr-oxide and Ti-oxides was found to occur at the crack tip prior to formation of unstable oxides. To contrast with the threshold failure mode regime, a quantitative assessment of the role that the intergranular failure mode has on cyclic FCG behavior in the Paris regime was also performed. It was demonstrated that even a very limited intergranular failure content dominates the FCG response under mixed mode failure conditions.

Functional complexity of the axonal growth cone: a proteomic analysis.

Directory of Open Access Journals (Sweden)

Adriana Estrada-Bernal

Full Text Available The growth cone, the tip of the emerging neurite, plays a crucial role in establishing the wiring of the developing nervous system. We performed an extensive proteomic analysis of axonal growth cones isolated from the brains of fetal Sprague-Dawley rats. Approximately 2000 proteins were identified at ≥ 99% confidence level. Using informatics, including functional annotation cluster and KEGG pathway analysis, we found great diversity of proteins involved in axonal pathfinding, cytoskeletal remodeling, vesicular traffic and carbohydrate metabolism, as expected. We also found a large and complex array of proteins involved in translation, protein folding, posttranslational processing, and proteasome/ubiquitination-dependent degradation. Immunofluorescence studies performed on hippocampal neurons in culture confirmed the presence in the axonal growth cone of proteins representative of these processes. These analyses also provide evidence for rough endoplasmic reticulum and reveal a reticular structure equipped with Golgi-like functions in the axonal growth cone. Furthermore, Western blot revealed the growth cone enrichment, relative to fetal brain homogenate, of some of the proteins involved in protein synthesis, folding and catabolism. Our study provides a resource for further research and amplifies the relatively recently developed concept that the axonal growth cone is equipped with proteins capable of performing a highly diverse range of functions.

Stoichiometry control of complex oxides by sequential pulsed-laser deposition from binary-oxide targets

Energy Technology Data Exchange (ETDEWEB)

Herklotz, A. [ORNL, Materials Science and Technology Division, Bethel Valley Road, Oak Ridge, Tennessee 37831-6056 (United States); Martin Luther University Halle-Wittenberg, Institute for Physics, Von-Danckelmann-Platz 3, 06120 Halle (Germany); Dörr, K. [Martin Luther University Halle-Wittenberg, Institute for Physics, Von-Danckelmann-Platz 3, 06120 Halle (Germany); Ward, T. Z.; Eres, G. [ORNL, Materials Science and Technology Division, Bethel Valley Road, Oak Ridge, Tennessee 37831-6056 (United States); Christen, H. M.; Biegalski, M. D. [ORNL, Center for Nanophase Materials Sciences, Bethel Valley Road, Oak Ridge, Tennessee 37831-6496 (United States)

2015-03-30

To have precise atomic layer control over interfaces, we examine the growth of complex oxides through the sequential deposition from binary targets by pulsed laser deposition. In situ reflection high-energy electron diffraction (RHEED) is used to control the growth and achieve films with excellent structural quality. The growth from binary oxide targets is fundamentally different from single target growth modes and shows more similarities to shuttered growth by molecular beam epitaxy. The RHEED intensity oscillations of non-stoichiometric growth are consistent with a model of island growth and accumulation of excess material on the surface that can be utilized to determine the correct stoichiometry for growth. Correct monolayer doses can be determined through an envelope frequency in the RHEED intensity oscillations. In order to demonstrate the ability of this growth technique to create complex heterostructures, the artificial n = 2 and 3 Sr{sub n+1}Ti{sub n}O{sub 3n+1} Ruddlesden-Popper phases are grown with good long-range order. This method enables the precise unit-cell level control over the structure of perovskite-type oxides, and thus the growth of complex materials with improved structural quality and electronic functionality.

Holographic complexity and two identities of action growth

Energy Technology Data Exchange (ETDEWEB)

Huang, Hyat, E-mail: hyat@mail.bnu.edu.cn; Feng, Xing-Hui, E-mail: xhfengp@mail.bnu.edu.cn; Lü, H., E-mail: mrhonglu@gmail.com

2017-06-10

The recently proposed complexity-action conjecture allows one to calculate how fast one can produce a quantum state from a reference state in terms of the on-shell action of the dual AdS black hole at the Wheeler–DeWitt patch. We show that the action growth rate is given by the difference of the generalized enthalpy between the two corresponding horizons. The proof relies on the second identity that the surface-term contribution on a horizon is given by the product of the associated temperature and entropy.

Growth mode, magnetic and magneto-optical properties of pulsed-laser-deposited Au/Co/Au(1 1 1) trilayers

International Nuclear Information System (INIS)

Clavero, C.; Cebollada, A.; Armelles, G.; Fruchart, O.

2010-01-01

The growth mode, magnetic and magneto-optical properties of epitaxial Au/Co/Au(1 1 1) ultrathin trilayers grown by pulsed-laser deposition (PLD) under ultra-high vacuum are presented. Sapphire wafers buffered with a single-crystalline Mo(1 1 0) buffer layer were used as substrates. Owing to PLD-induced interfacial intermixing at the lower Co/Au(1 1 1) interface, a close-to layer-by-layer growth mode is promoted. Surprisingly, despite this intermixing, ferromagnetic behavior is found at room temperature for coverings starting at 1 atomic layer (AL). The films display perpendicular magnetization with anisotropy constants reduced by 50% compared to TD-grown or electrodeposited films, and with a coercivity more than one order of magnitude lower (≤5mT). The magneto-optical (MO) response in the low Co thickness range is dominated by Au/Co interface contributions. For thicknesses starting at 3 AL Co, the MO response has a linear dependence with the Co thickness, indicative of a continuous-film-like MO behavior.

Prediction of Accurate Mixed Mode Fatigue Crack Growth Curves using the Paris' Law

Science.gov (United States)

Sajith, S.; Krishna Murthy, K. S. R.; Robi, P. S.

2017-12-01

Accurate information regarding crack growth times and structural strength as a function of the crack size is mandatory in damage tolerance analysis. Various equivalent stress intensity factor (SIF) models are available for prediction of mixed mode fatigue life using the Paris' law. In the present investigation these models have been compared to assess their efficacy in prediction of the life close to the experimental findings as there are no guidelines/suggestions available on selection of these models for accurate and/or conservative predictions of fatigue life. Within the limitations of availability of experimental data and currently available numerical simulation techniques, the results of present study attempts to outline models that would provide accurate and conservative life predictions.

Resistive wall modes in the EXTRAP T2R reversed-field pinch

Science.gov (United States)

Brunsell, P. R.; Malmberg, J.-A.; Yadikin, D.; Cecconello, M.

2003-10-01

Resistive wall modes (RWM) in the reversed field pinch are studied and a detailed comparison of experimental growth rates and linear magnetohydrodynamic (MHD) theory is made. RWM growth rates are experimentally measured in the thin shell device EXTRAP T2R [P. R. Brunsell et al., Plasma Phys. Controlled Fusion 43, 1 (2001)]. Linear MHD calculations of RWM growth rates are based on experimental equilibria. Experimental and linear MHD RWM growth rate dependency on the equilibrium profiles is investigated experimentally by varying the pinch parameter Θ=Bθ(a)/ in the range Θ=1.5-1.8. Quantitative agreement between experimental and linear MHD growth rates is seen. The dominating RWMs are the internal on-axis modes (having the same helicity as the central equilibrium field). At high Θ, external nonresonant modes are also observed. For internal modes experimental growth rates decrease with Θ while for external modes, growth rates increase with Θ. The effect of RWMs on the reversed-field pinch plasma performance is discussed.

Fast convergent frequency-domain MIMO equalizer for few-mode fiber communication systems

Science.gov (United States)

He, Xuan; Weng, Yi; Wang, Junyi; Pan, Z.

2018-02-01

Space division multiplexing using few-mode fibers has been extensively explored to sustain the continuous traffic growth. In few-mode fiber optical systems, both spatial and polarization modes are exploited to transmit parallel channels, thus increasing the overall capacity. However, signals on spatial channels inevitably suffer from the intrinsic inter-modal coupling and large accumulated differential mode group delay (DMGD), which causes spatial modes de-multiplex even harder. Many research articles have demonstrated that frequency domain adaptive multi-input multi-output (MIMO) equalizer can effectively compensate the DMGD and demultiplex the spatial channels with digital signal processing (DSP). However, the large accumulated DMGD usually requires a large number of training blocks for the initial convergence of adaptive MIMO equalizers, which will decrease the overall system efficiency and even degrade the equalizer performance in fast-changing optical channels. Least mean square (LMS) algorithm is always used in MIMO equalization to dynamically demultiplex the spatial signals. We have proposed to use signal power spectral density (PSD) dependent method and noise PSD directed method to improve the convergence speed of adaptive frequency domain LMS algorithm. We also proposed frequency domain recursive least square (RLS) algorithm to further increase the convergence speed of MIMO equalizer at cost of greater hardware complexity. In this paper, we will compare the hardware complexity and convergence speed of signal PSD dependent and noise power directed algorithms against the conventional frequency domain LMS algorithm. In our numerical study of a three-mode 112 Gbit/s PDM-QPSK optical system with 3000 km transmission, the noise PSD directed and signal PSD dependent methods could improve the convergence speed by 48.3% and 36.1% respectively, at cost of 17.2% and 10.7% higher hardware complexity. We will also compare the frequency domain RLS algorithm against

Hyper-resistivity produced by tearing mode turbulence

International Nuclear Information System (INIS)

Strauss, H.R.

1986-01-01

Tearing mode turbulence produces a hyper-resistivity or effective anomalous electron viscosity. The hyper-resistivity is calculated for the mean magnetic field quasilinearly, and for long-wavelength modes using the direct interaction approximation. The hyper-resistivity accounts for current relaxation in reversed-field pinch experiments, and gives a magnetic fluctuation sealing of S -1 /sup // 3 . It causes enhanced tearing mode growth rates in the turbulent phase of tokamak disruptions. In astrophysics, it limits magnetic energy growth due to the dynamo effect, and may explain rapid reconnection phenomena such as solar flares

A computer program for external modes in complex ionic crystals (the rigid molecular-ion model)

International Nuclear Information System (INIS)

Chaplot, S.L.

1978-01-01

A computer program DISPR has been developed to calculate the external mode phonon dispersion relation in the harmonic approximation for complex ionic crystals using the rigid molecular ion model. A description of the program, the flow diagram and the required input information are given. A sample calculation for α-KNO 3 is presented. The program can handle any type of crystal lattice with any number of atoms and molecules per unit cell with suitable changes in dimension statements. (M.G.B.)

Whimsicality of multi-mode Hasegawa space-charge waves in a complex plasma containing collision-dominated electrons and streaming ions

Science.gov (United States)

Lee, Myoung-Jae; Jung, Young-Dae

2017-09-01

The influence of collision-dominated electrons on multi-mode Hasegawa space-charge waves are investigated in a complex plasma containing streaming ions. The dispersion relation for the multi-mode Hasegawa space-charge wave propagating in a cylindrical waveguide filled with dusty plasma containing collision-dominated electrons and streaming ions is derived by using the fluid equations and Poisson’s equation which lead to a Bessel equation. By the boundary condition, the roots of the Bessel function would characterize the property of space-charge wave propagation. It is found that two solutions exist for wave frequency, which are affected by the radius of waveguide and the roots of the Bessel function. The damping and growing modes are found to be enhanced by an increase of the radius. However, an increase of electron collision frequency would suppress the damping and the growing modes of the propagating space-charge wave in a cylindrical waveguide plasma.

A novel tridentate coordination mode for the carbonatonickel system exhibited in an unusual hexanuclear nickel(II) mu3-carbonato-bridged complex.

Science.gov (United States)

Anderson, James C; Blake, Alexander J; Moreno, Rafael Bou; Raynel, Guillaume; van Slageren, Joris

2009-11-14

The fixation of CO(2) at ambient temperature has been achieved by the reaction of Ni(cod)(2) and TMEDA in CO(2) saturated THF that yields a novel hexanuclear nickel(II) mu(3)-carbonato bridged complex [Ni(6)(mu(3)-CO(3))(4)(TMEDA)(6)(H(2)O)(12)](OH)(4) in 59% yield. The complex was characterised by MS analysis and the structure corroborated by single-crystal X-ray crystallography. The complex exhibits a rare carbonato binding mode for Ni(II) complexes and moderately strong antiferromagnetic interactions.

Linear neoclassical tearing mode in tokamaks

International Nuclear Information System (INIS)

Shaing, K. C.

2007-01-01

The growth rate of linear tearing modes in tokamaks is calculated including the neoclassical dissipation mechanism. It is found that when the growth rate is much smaller than the ion-ion collision frequency, the growth rate is reduced approximately by a factor of (B p /B) 2/5 from its standard value, and when the growth rate is much larger than the ion-ion collision frequency, the growth rate is reduced by a factor [√(ε)/(1.6q 2 )] 1/5 . Here, B p is the poloidal magnetic field strength, B is the magnetic field strength, ε is the inverse aspect ratio, and q is the safety factor. The width of the resistive layer is broadened when compared to that of the standard theory. In both limits, the growth rate and the resistive layer width only depend on B p and are independent of B. The growth rates in the plateau regime and for the inertia dominant modes are also presented

Efficient growth of complex graph states via imperfect path erasure

International Nuclear Information System (INIS)

Campbell, Earl T; Fitzsimons, Joseph; Benjamin, Simon C; Kok, Pieter

2007-01-01

Given a suitably large and well connected (complex) graph state, any quantum algorithm can be implemented purely through local measurements on the individual qubits. Measurements can also be used to create the graph state: path erasure techniques allow one to entangle multiple qubits by determining only global properties of the qubits. Here, this powerful approach is extended by demonstrating that even imperfect path erasure can produce the required graph states with high efficiency. By characterizing the degree of error in each path erasure attempt, one can subsume the resulting imperfect entanglement into an extended graph state formalism. The subsequent growth of the improper graph state can be guided, through a series of strategic decisions, in such a way as to bound the growth of the error and eventually yield a high-fidelity graph state. As an implementation of these techniques, we develop an analytic model for atom (or atom-like) qubits in mismatched cavities, under the double-heralding entanglement procedure of Barrett and Kok (2005 Phys. Rev. A 71 060310). Compared to straightforward post-selection techniques our protocol offers a dramatic improvement in growing complex high-fidelity graph states

Synthesis and Characterization of Nanodiamond-Growth Factor Complexes Towards Applications in Oral Implantation and Regenerative Medicine.

Science.gov (United States)

Bang, Julie; Ting, Caleb; Wang, Peter; Kim, Ted; Wang, Kenneth; Kee, Theodore; Miya, Darron; Ho, Dean; Lee, Dong-Keun

2018-02-19

Current challenges in the field of regenerative medicine include the need to deliver sustained concentrations of growth factors and genes that are required to induce the repair of deficient tissues. Enhancement of drug delivery and uptake may result in improved growth factor efficacy. Nanodiamonds (NDs) were explored as potential growth factor delivery agents due to the many favorable properties that they possess. For example, ND's biocompatibility has been extensively validated pre-clinically. In addition, they can be scalably produced through impact events such as detonation. They possess notably faceted surfaces with diverse electrostatic properties that allow the rapid formation of growth factor complexes. In this study, a complex based on NDs conjugated to epidermal growth factor (EGF) functionalized with Alexa Fluor 488 (ND-EGF) was developed. ND-EGF was comprehensively evaluated using dynamic light scattering and zeta potential analysis. Furthermore, the NDs were capable of eluting EGF in a sustained fashion. Therefore, ND-EGF may serve as a promising nano-biomaterial for sustained growth factor elution.

Crystal structure of the tyrosine kinase domain of the hepatocyte growth factor receptor c-Met and its complex with the microbial alkaloid K-252a.

Science.gov (United States)

Schiering, Nikolaus; Knapp, Stefan; Marconi, Marina; Flocco, Maria M; Cui, Jean; Perego, Rita; Rusconi, Luisa; Cristiani, Cinzia

2003-10-28

The protooncogene c-met codes for the hepatocyte growth factor receptor tyrosine kinase. Binding of its ligand, hepatocyte growth factor/scatter factor, stimulates receptor autophosphorylation, which leads to pleiotropic downstream signaling events in epithelial cells, including cell growth, motility, and invasion. These events are mediated by interaction of cytoplasmic effectors, generally through Src homology 2 (SH2) domains, with two phosphotyrosine-containing sequence motifs in the unique C-terminal tail of c-Met (supersite). There is a strong link between aberrant c-Met activity and oncogenesis, which makes this kinase an important cancer drug target. The furanosylated indolocarbazole K-252a belongs to a family of microbial alkaloids that also includes staurosporine. It was recently shown to be a potent inhibitor of c-Met. Here we report the crystal structures of an unphosphorylated c-Met kinase domain harboring a human cancer mutation and its complex with K-252a at 1.8-A resolution. The structure follows the well established architecture of protein kinases. It adopts a unique, inhibitory conformation of the activation loop, a catalytically noncompetent orientation of helix alphaC, and reveals the complete C-terminal docking site. The first SH2-binding motif (1349YVHV) adopts an extended conformation, whereas the second motif (1356YVNV), a binding site for Grb2-SH2, folds as a type II Beta-turn. The intermediate portion of the supersite (1353NATY) assumes a type I Beta-turn conformation as in an Shc-phosphotyrosine binding domain peptide complex. K-252a is bound in the adenosine pocket with an analogous binding mode to those observed in previously reported structures of protein kinases in complex with staurosporine.

A third mode of surface‐associated growth: immobilization of Salmonella enterica serovar Typhimurium modulates the RpoS‐directed transcriptional programme

DEFF Research Database (Denmark)

Knudsen, Gitte Maegaard; Nielsen, Maj‐Britt; Grassby, Terri

2012-01-01

environments in both food products and the GI tract. This immobilized mode of growth has not been widely studied. To develop our understanding of the effects of immobilization upon a food‐borne bacterial pathogen, we used the IFR Gel Cassette model. The transcriptional programme and metabolomic profile...

Growth scenarios for sub-Saharan countries in the framework of economic complexity

OpenAIRE

Cristelli, Matthieu; Tacchella, Andrea; Zaccaria, Andrea; Pietronero, Luciano

2014-01-01

We present a comparative analysis of the medium-long term perspectives of development for sub-Saharan countries in the framework of economic complexity. This analysis is made in comparison with the development of Asian tigers. Economic complexity is a data-driven framework which aims at providing a more scientific basis for the economic theory and it has a specific focus on understanding the determinants of growth by means of two new economic dimensions: the country fitness and the produc...

Two-dimensional Schrödinger symmetry and three-dimensional breathers and Kelvin-ripple complexes as quasi-massive-Nambu-Goldstone modes

Science.gov (United States)

Takahashi, Daisuke A.; Ohashi, Keisuke; Fujimori, Toshiaki; Nitta, Muneto

2017-08-01

Bose-Einstein condensates (BECs) confined in a two-dimensional (2D) harmonic trap are known to possess a hidden 2D Schrödinger symmetry, that is, the Schrödinger symmetry modified by a trapping potential. Spontaneous breaking of this symmetry gives rise to a breathing motion of the BEC, whose oscillation frequency is robustly determined by the strength of the harmonic trap. In this paper, we demonstrate that the concept of the 2D Schrödinger symmetry can be applied to predict the nature of three-dimensional (3D) collective modes propagating along a condensate confined in an elongated trap. We find three kinds of collective modes whose existence is robustly ensured by the Schrödinger symmetry, which are physically interpreted as one breather mode and two Kelvin-ripple complex modes, i.e., composite modes in which the vortex core and the condensate surface oscillate interactively. We provide analytical expressions for the dispersion relations (energy-momentum relation) of these modes using the Bogoliubov theory [D. A. Takahashi and M. Nitta, Ann. Phys. 354, 101 (2015), 10.1016/j.aop.2014.12.009]. Furthermore, we point out that these modes can be interpreted as "quasi-massive-Nambu-Goldstone (NG) modes", that is, they have the properties of both quasi-NG and massive NG modes: quasi-NG modes appear when a symmetry of a part of a Lagrangian, which is not a symmetry of a full Lagrangian, is spontaneously broken, while massive NG modes appear when a modified symmetry is spontaneously broken.

Vibrational transitions in hydrogen bonded bimolecular complexes – A local mode perturbation theory approach to transition frequencies and intensities

DEFF Research Database (Denmark)

Mackeprang, Kasper; Kjærgaard, Henrik Grum

2017-01-01

The local mode perturbation theory (LMPT) model was developed to improve the description of hydrogen bonded XH-stretching transitions, where X is typically O or N. We present a modified version of the LMPT model to extend its application from hydrated bimolecular complexes to hydrogen bonded...

Nonlinear MHD and energetic particle modes in stellarators

International Nuclear Information System (INIS)

Strauss, H.R.

2002-01-01

The M3D code has been applied to ideal, resistive, two fluid, and hybrid simulations of compact quasi axisymmetric stellarators. When beta exceeds a threshold, low poloidal mode number (m=6∼18) modes grow exponentially, clearly distinguishable from the equilibrium evolution. Simulations of NCSX have beta limits are significantly higher than the infinite mode number ballooning limits. In the presence of resistivity, these modes occur well below the ideal limit. Their growth rate scaling with resistivity is similar to tearing modes. With sufficient viscosity, the growth rate becomes slow enough to allow calculations of magnetic island evolution. Hybrid gyrokinetic simulations with energetic particles indicate that global shear Alfven TAE - like modes can be destabilized in stellarators. Computations in a two - period compact stellarator obtained a predominantly n=1 toroidal mode with about the expected TAE frequency. Work is in progress to study fast ion-driven Alfven modes in NCSX. (author)

Experimental study of complex mixed-mode oscillations generated in a Bonhoeffer-van der Pol oscillator under weak periodic perturbation

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Kuniyasu, E-mail: kuniyasu.shimizu@it-chiba.ac.jp [Department of Electrical, Electronics and Computer Engineering, Chiba Institute of Technology, Narashino 275-0016 (Japan); Sekikawa, Munehisa [Department of Mechanical and Intelligent Engineering, Utsunomiya University, Utsunomiya 321-8585 (Japan); Inaba, Naohiko [Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kawasaki 214-8571 (Japan)

2015-02-15

Bifurcations of complex mixed-mode oscillations denoted as mixed-mode oscillation-incrementing bifurcations (MMOIBs) have frequently been observed in chemical experiments. In a previous study [K. Shimizu et al., Physica D 241, 1518 (2012)], we discovered an extremely simple dynamical circuit that exhibits MMOIBs. Our model was represented by a slow/fast Bonhoeffer-van der Pol circuit under weak periodic perturbation near a subcritical Andronov-Hopf bifurcation point. In this study, we experimentally and numerically verify that our dynamical circuit captures the essence of the underlying mechanism causing MMOIBs, and we observe MMOIBs and chaos with distinctive waveforms in real circuit experiments.

The effect of pressure anisotropy on ballooning modes in tokamak plasmas

Science.gov (United States)

Johnston, A.; Hole, M. J.; Qu, Z. S.; Hezaveh, H.

2018-06-01

Edge Localised Modes are thought to be caused by a spectrum of magnetohydrodynamic instabilities, including the ballooning mode. While ballooning modes have been studied extensively both theoretically and experimentally, the focus of the vast majority of this research has been on isotropic plasmas. The prevalence of pressure anisotropy in modern tokamaks thus motivates further study of these modes. This paper presents a numerical analysis of ballooning modes in anisotropic equilibria. The investigation was conducted using the newly-developed codes HELENA+ATF and MISHKA-A, which adds anisotropic physics to equilibria and stability analysis. We have examined the impact of anisotropy on the stability of an n = 30 ballooning mode, confirming results conform to previous calculations in the isotropic limit. Growth rates of ballooning modes in equilibria with different levels of anisotropy were then calculated using the stability code MISHKA-A. The key finding was that the level of anisotropy had a significant impact on ballooning mode growth rates. For {T}\\perp > {T}| | , typical of ICRH heating, the growth rate increases, while for {T}\\perp < {T}| | , typical of neutral beam heating, the growth rate decreases.

Spacecraft Complexity Subfactors and Implications on Future Cost Growth

Science.gov (United States)

Leising, Charles J.; Wessen, Randii; Ellyin, Ray; Rosenberg, Leigh; Leising, Adam

2013-01-01

During the last ten years the Jet Propulsion Laboratory has used a set of cost-risk subfactors to independently estimate the magnitude of development risks that may not be covered in the high level cost models employed during early concept development. Within the last several years the Laboratory has also developed a scale of Concept Maturity Levels with associated criteria to quantitatively assess a concept's maturity. This latter effort has been helpful in determining whether a concept is mature enough for accurate costing but it does not provide any quantitative estimate of cost risk. Unfortunately today's missions are significantly more complex than when the original cost-risk subfactors were first formulated. Risks associated with complex missions are not being adequately evaluated and future cost growth is being underestimated. The risk subfactor process needed to be updated.

Surface modes in physics

CERN Document Server

Sernelius, Bo E

2011-01-01

Electromagnetic surface modes are present at all surfaces and interfaces between material of different dielectric properties. These modes have very important effects on numerous physical quantities: adhesion, capillary force, step formation and crystal growth, the Casimir effect etc. They cause surface tension and wetting and they give rise to forces which are important e.g. for the stability of colloids.This book is a useful and elegant approach to the topic, showing how the concept of electromagnetic modes can be developed as a unifying theme for a range of condensed matter physics. The

Unstable oscillatory Pierce modes of neutralized electron beams

International Nuclear Information System (INIS)

Cary, J.R.; Lemons, D.S.

1982-01-01

Oscillatory modes of the Pierce system have been calculated. These modes are found to have growth rates comparable to the previously investigated purely growing modes. When these modes are included, it is found that the Pierce system is unstable for most values of ω/sub p/ L/V 0 >π

Sliding mode control and observation

CERN Document Server

Shtessel, Yuri; Fridman, Leonid; Levant, Arie

2014-01-01

The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

Effects of Trophic Modes, Carbon Sources, and Salinity on the Cell Growth and Lipid Accumulation of Tropic Ocean Oilgae Strain Desmodesmus sp. WC08.

Science.gov (United States)

Zhao, Zhenyu; Ma, Shasha; Li, Ang; Liu, Pinghuai; Wang, Meng

2016-10-01

The effects of trophic modes, carbon sources, and salinity on the growth and lipid accumulation of a marine oilgae Desmodesmus sp. WC08 in different trophic cultures were assayed by single factor experiment based on the blue-green algae medium (BG-11). The results implied that biomass and lipid accumulation culture process were optimized depending on the tophic modes, sorts, and concentration of carbon sources and salinity in the cultivation. There was no significant difference in growth or lipid accumulation with Na 2 CO 3 amendment or NaHCO 3 amendment. However, Na 2 CO 3 amendment did enhance the biomass and lipid accumulation to some extent. The highest Desmodesmus sp. WC08 biomass and lipid accumulation was achieved in the growth medium with photoautotrophic cultivation, 0.08 g L -1 Na 2 CO 3 amendment and 15 g L -1 sea salt, respectively.

Nonlinear evolution of Mack modes in a hypersonic boundary layer

Science.gov (United States)

Chokani, Ndaona

2005-01-01

In hypersonic boundary layer flows the nonlinear disturbance evolution occurs relatively slowly over a very long length scale and has a profound effect on boundary layer transition. In the case of low-level freestream disturbances and negligible surface roughness, the transition is due to the modal growth of exponentially growing Mack modes that are destabilized by wall cooling. Cross-bicoherence measurements, derived from hot-wire data acquired in a quiet hypersonic tunnel, are used to identify and quantify phase-locked, quadratic sum and difference interactions involving the Mack modes. In the early stages of the nonlinear disturbance evolution, cross-bicoherence measurements indicate that the energy exchange between the Mack mode and the mean flow first occurs to broaden the sidebands; this is immediately followed by a sum interaction of the Mack mode to generate the first harmonic. In the next stages of the nonlinear disturbance evolution, there is a difference interaction of the first harmonic, which is also thought to contribute to the mean flow distortion. This difference interaction, in the latter stages, is also accompanied by a difference interaction between Mack mode and first harmonic, and a sum interaction, which forces the second harmonic. Analysis using the digital complex demodulation technique, shows that the low-frequency, phase-locked interaction that is identified in the cross bicoherence when the Mack mode and first harmonic have large amplitudes, arises due to the amplitude modulation of Mack mode and first harmonic.

MODELING OF OPERATION MODES OF SHIP POWER PLANT OF COMBINED PROPULSION COMPLEX WITH CONTROL SYSTEM BASED ON ELECTRONIC CONTROLLERS

Directory of Open Access Journals (Sweden)

E. A. Yushkov

2016-12-01

Full Text Available Purpose. Designing of diagrams to optimize mathematic model of the ship power plant (SPP combined propulsion complexes (CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. Methodology. After analyzing of ship power plant modes of CPC proposed diagrams to optimize mathematic model of the above mentioned complex. The model based on using of electronic controllers in automatic regulation and control systems for diesel and thruster which allow to actualize more complicated control algorithm with viewpoint of increasing working efficiency of ship power plant at normal and emergency modes. Results. Determined suitability of comparative computer modeling in MatLab Simulink for building of imitation model objects based on it block diagrams and mathematic descriptions. Actualized diagrams to optimize mathematic model of the ship’s power plant (SPP combined propulsion complexes (CPC with Azipod system in MatLab Simulink software package Ships_CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. The function blocks of proposed complex are the main structural units which allow to investigate it normal and emergency modes. Originality. This model represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». For example, the function boxes outputs of PID-regulators of MRDG depends from set excitation voltage and rotating frequency that in turn depends from power-station load and respond that is a ship moving or dynamically positioning, and come on input (inputs of thruster rotating frequency PID-regulator models. Practical value. The results of researches planned to use in

Algorithmic complexity of growth hormone release in humans

Energy Technology Data Exchange (ETDEWEB)

Prank, K.; Wagner, M.; Brabant, G. [Medical School Hannover (Germany)

1996-12-31

Most hormones are secreted in an pulsatile rather than in a constant manner. This temporal pattern of pulsatile hormone release plays an important role in the regulation of cellular function and structure. In healthy humans growth hormone (GH) secretion is characterized by distinct pulses whereas patients bearing a GH producing tumor accompanied with excessive secretion (acromegaly) exhibit a highly irregular pattern of GH release. It has been hypothesized that this highly disorderly pattern of GH release in acromegaly arises from random events in the GH-producing tumor under decreased normal control of GH secretion. Using a context-free grammar complexity measure (algorithmic complexity) in conjunction with random surrogate data sets we demonstrate that the temporal pattern of GH release in acromegaly is not significantly different from a variety of stochastic processes. In contrast, normal subjects clearly exhibit deterministic structure in their temporal patterns of GH secretion. Our results support the hypothesis that GH release in acromegaly is due to random events in the GH-producing tumorous cells which might become independent from hypothalamic regulation. 17 refs., 1 fig., 2 tabs.

Normal mode approach to modelling of feedback stabilization of the resistive wall mode

International Nuclear Information System (INIS)

Chu, M.S.; Chance, M.S.; Okabayashi, M.; Glasser, A.H.

2003-01-01

Feedback stabilization of the resistive wall mode (RWM) of a plasma in a general feedback configuration is formulated in terms of the normal modes of the plasma-resistive wall system. The growth/damping rates and the eigenfunctions of the normal modes are determined by an extended energy principle for the plasma during its open (feedback) loop operation. A set of equations are derived for the time evolution of these normal modes with currents in the feedback coils. The dynamics of the feedback system is completed by the prescription of the feedback logic. The feasibility of the feedback is evaluated by using the Nyquist diagram method or by solving the characteristic equations. The elements of the characteristic equations are formed from the growth and damping rates of the normal modes, the sensor matrix of the perturbation fluxes detected by the sensor loops, the excitation matrix of the energy input to the normal modes by the external feedback coils, and the feedback logic. (The RWM is also predicted to be excited by an external error field to a large amplitude when it is close to marginal stability.) This formulation has been implemented numerically and applied to the DIII-D tokamak. It is found that feedback with poloidal sensors is much more effective than feedback with radial sensors. Using radial sensors, increasing the number of feedback coils from a central band on the outboard side to include an upper and a lower band can substantially increase the effectiveness of the feedback system. The strength of the RWM that can be stabilized is increased from γτ w = 1 to 30 (γ is the growth rate of the RWM in the absence of feedback and τ w is the resistive wall time constant) Using poloidal sensors, just one central band of feedback coils is sufficient for the stabilization of the RWM with γτ w = 30. (author)

Pad-mode-induced instantaneous mode instability for simple models of brake systems

Science.gov (United States)

Oberst, S.; Lai, J. C. S.

2015-10-01

Automotive disc brake squeal is fugitive, transient and remains difficult to predict. In particular, instantaneous mode squeal observed experimentally does not seem to be associated with mode coupling and its mechanism is not clear. The effects of contact pressures, friction coefficients as well as material properties (pressure and temperature dependency and anisotropy) for brake squeal propensity have not been systematically explored. By analysing a finite element model of an isotropic pad sliding on a plate similar to that of a previously reported experimental study, pad modes have been identified and found to be stable using conventional complex eigenvalue analysis. However, by subjecting the model to contact pressure harmonic excitation for a range of pressures and friction coefficients, a forced response analysis reveals that the dissipated energy for pad modes is negative and becomes more negative with increasing contact pressures and friction coefficients, indicating the potential for instabilities. The frequency of the pad mode in the sliding direction is within the range of squeal frequencies observed experimentally. Nonlinear time series analysis of the vibration velocity also confirms the evolution of instabilities induced by pad modes as the friction coefficient increases. By extending this analysis to a more realistic but simple brake model in the form of a pad-on-disc system, in-plane pad-modes, which a complex eigenvalue analysis predicts to be stable, have also been identified by negative dissipated energy for both isotropic and anisotropic pad material properties. The influence of contact pressures on potential instabilities has been found to be more dominant than changes in material properties owing to changes in pressure or temperature. Results here suggest that instantaneous mode squeal is likely caused by in-plane pad-mode instabilities.

Probable mode prediction for H.264 advanced video coding P slices using removable SKIP mode distortion estimation

Science.gov (United States)

You, Jongmin; Jeong, Jechang

2010-02-01

The H.264/AVC (advanced video coding) is used in a wide variety of applications including digital broadcasting and mobile applications, because of its high compression efficiency. The variable block mode scheme in H.264/AVC contributes much to its high compression efficiency but causes a selection problem. In general, rate-distortion optimization (RDO) is the optimal mode selection strategy, but it is computationally intensive. For this reason, the H.264/AVC encoder requires a fast mode selection algorithm for use in applications that require low-power and real-time processing. A probable mode prediction algorithm for the H.264/AVC encoder is proposed. To reduce the computational complexity of RDO, the proposed method selects probable modes among all allowed block modes using removable SKIP mode distortion estimation. Removable SKIP mode distortion is used to estimate whether or not a further divided block mode is appropriate for a macroblock. It is calculated using a no-motion reference block with a few computations. Then the proposed method reduces complexity by performing the RDO process only for probable modes. Experimental results show that the proposed algorithm can reduce encoding time by an average of 55.22% without significant visual quality degradation and increased bit rate.

Zonal Flows Driven by Small-Scale Drift-Alfven Modes

International Nuclear Information System (INIS)

Li Dehui; Zhou Deng

2011-01-01

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

Crystal structure of glucose isomerase in complex with xylitol inhibitor in one metal binding mode.

Science.gov (United States)

Bae, Ji-Eun; Kim, In Jung; Nam, Ki Hyun

2017-11-04

Glucose isomerase (GI) is an intramolecular oxidoreductase that interconverts aldoses and ketoses. These characteristics are widely used in the food, detergent, and pharmaceutical industries. In order to obtain an efficient GI, identification of novel GI genes and substrate binding/inhibition have been studied. Xylitol is a well-known inhibitor of GI. In Streptomyces rubiginosus, two crystal structures have been reported for GI in complex with xylitol inhibitor. However, a structural comparison showed that xylitol can have variable conformation at the substrate binding site, e.g., a nonspecific binding mode. In this study, we report the crystal structure of S. rubiginosus GI in a complex with xylitol and glycerol. Our crystal structure showed one metal binding mode in GI, which we presumed to represent the inactive form of the GI. The metal ion was found only at the M1 site, which was involved in substrate binding, and was not present at the M2 site, which was involved in catalytic function. The O 2 and O 4 atoms of xylitol molecules contributed to the stable octahedral coordination of the metal in M1. Although there was no metal at the M2 site, no large conformational change was observed for the conserved residues coordinating M2. Our structural analysis showed that the metal at the M2 site was not important when a xylitol inhibitor was bound to the M1 site in GI. Thus, these findings provided important information for elucidation or engineering of GI functions. Copyright © 2017 Elsevier Inc. All rights reserved.

Propagating annular modes

Science.gov (United States)

Sheshadri, A.; Plumb, R. A.

2017-12-01

The leading "annular mode", defined as the dominant EOF of surface pressure or of zonal mean zonal wind variability, appears as a dipolar structure straddling the mean midlatitude jet and thus seems to describe north-south wobbling of the jet latitude. However, extratropical zonal wind anomalies frequently tend to migrate poleward. This behavior can be described by the first two EOFs, the first (AM1) being the dipolar structure, and the second (AM2) having a tripolar structure centered on the mean jet. Taken in isolation, AM1 thus describes a north-south wobbling of the jet position, while AM2 describes a strengthening and narrowing of the jet. However, despite the fact that they are spatially orthogonal, and their corresponding time series temporally orthogonal, AM1 and AM2 are not independent, but show significant lag-correlations which reveal the propagation. The EOFs are not modes of the underlying dynamical system governing the zonal flow evolution. The true modes can be estimated using principal oscillation pattern (POP) analysis. In the troposphere, the leading POPs manifest themselves as a pair of complex conjugate structures with conjugate eigenvalues thus, in reality, constituting a single, complex, mode that describes propagating anomalies. Even though the principal components associated with the two leading EOFs decay at different rates, each decays faster than the true mode. These facts have implications for eddy feedback and the susceptibility of the mode to external perturbations. If one interprets the annular modes as the modes of the system, then simple theory predicts that the response to steady forcing will usually be dominated by AM1 (with the longest time scale). However, such arguments should really be applied to the true modes. Experiments with a simplified GCM show that climate response to perturbations do not necessarily have AM1 structures. Implications of these results for stratosphere-troposphere interactions are explored. The POP

Fatigue crack growth in mixed mode I+III+III non proportional loading conditions in a 316 stainless steel, experimental analysis and modelization of the effects of crack tip plasticity

International Nuclear Information System (INIS)

Fremy, F.

2012-01-01

This thesis deals with fatigue crack growth in non-proportional variable amplitude mixed mode I + II + III loading conditions and analyses the effects of internal stresses stemming from the confinement of the plastic zone in small scale yielding conditions. The tests showed that there are antagonistic long-distance and short-distance effects of the loading history on fatigue crack growth. The shape of loading path, and not only the maximum and minimum values in this path, is crucial and, by comparison, the effects of contact and friction are of lesser importance. Internal stresses play a major role on the fatigue crack growth rate and on the crack path. An approach was developed to analyze the elastic-plastic behavior of a representative section of the crack front using the FEA. A model reduction technic is used to extract the relevant information from the FE results. To do so, the velocity field is partitioned into mode I, II, III elastic and plastic components, each component being characterized by an intensity factor and a fixed spatial distribution. The calculations were used to select seven loading paths in I + II and I + II + III mixed mode conditions, which all have the same amplitudes for each mode, the same maximum, minimum and average values. These paths are supposed to be equivalent in the sense of common failure criteria, but differ significantly when the elastic-plastic behavior of the material is accounted for. The results of finite element simulations and of simulations using a simplified model proposed in this thesis are both in agreement with experimental results. The approach was also used to discuss the role of mode III loading steps. Since the material behavior is nonlinear, the nominal loading direction does not coincide with the plastic flow direction. Adding a mode III loading step in a mode I+II fatigue cycle, may, in some cases, significantly modify the behaviour of the crack (crack growth rate, crack path and plastic flow). (author)

Computational study of axisymmetric modes in noncircular cross section tokamaks

International Nuclear Information System (INIS)

Johnson, J.L.; Chance, M.S.; Greene, J.M.; Grimm, R.C.; Jardin, S.C.; Kerner, W.; Manickam, J.; Weimer, K.E.

1976-09-01

A major computational program to investigate the MHD equilibrium, stability, and nonlinear evolution properties of realistic tokamak configurations is proceeding. Preliminary application is made to the Princeton PDX device. Both axisymmetric (n = 0) modes and kink (n = 1) modes are found; the growth rates depend sensitively on the configuration. A study of the nonlinear evolution of axisymmetric modes in such a device shows that flux conservation in the vacuum region can limit their growth

Anisotropic Growth of Otavite on Calcite: Implications for Heteroepitaxial Growth Mechanisms

Energy Technology Data Exchange (ETDEWEB)

Riechers, Shawn L.; Kerisit, Sebastien N.

2017-12-18

Elucidating how cation intermixing can affect the mechanisms of heteroepitaxial growth in aqueous media has remained a challenging endeavor. Toward this goal, in situ atomic force microscopy was employed to image the heteroepitaxial growth of otavite (CdCO3) at the (10-14) surface of calcite (CaCO3) single crystals in static aqueous conditions. Heteroepitaxial growth proceeded via spreading of three-dimensional (3D) islands and two-dimensional (2D) atomic layers at low and high initial saturation levels, respectively. Experiments were carried out as a function of applied force and imaging mode thus enabling determination of growth mechanisms unaltered by imaging artifacts. This approach revealed the significant anisotropic nature of heteroepitaxial growth on calcite in both growth modes and its dependence on supersaturation, intermixing, and substrate topography. The 3D islands not only grew preferentially along the [42-1] direction relative to the [010] direction, resulting in rod-like surface precipitates, but also showed clear preference for growth from the island end rich in obtuse/obtuse kink sites. Pinning to step edges was observed to often reverse this tendency. In the 2D growth mode, the relative velocities of acute and obtuse steps were observed to switch between the first and second atomic layers. This phenomenon stemmed from the significant Cd-Ca intermixing in the first layer, despite bulk thermodynamics predicting the formation of almost pure otavite. Composition effects were also responsible for the inability of 3D islands to grow on 2D layers in cases where both modes were observed to occur simultaneously. Overall, the AFM images highlighted the effects of intermixing on heteroepitaxial growth, particularly how it can induce thickness-dependent growth mechanisms at the nanoscale.

Spatial stability of jets - the nonaxisymmetric fundamental and reflection modes

International Nuclear Information System (INIS)

Hardee, P.E.

1987-01-01

A spatial stability analysis of the relativistic dispersion relation governing the growth and propagation of harmonic components comprising a perturbation to the surface of a cylindrical jet is performed. The spatial growth of harmonic components associated with the nonaxisymmetric fundamental solution and reflection solutions of several Fourier modes are analyzed. Approximate analytical expressions describing resonant frequencies and wavelengths, and maximum growth rates at resonance applicable to relativistic jets are found from the dispersion relation, and the nature of the resonances is explored. On transonic jets there is only a fundamental solution for each Fourier mode with no resonance or maximum growth rate. On supersonic jets there is a fundamental solution and reflection solutions for each Fourier mode, and each solution contains a resonance at which the growth rate is a maximum. A numerical analysis of the fundamental and first three reflection solutions of the axisymmetric and first three nonaxisymmetric Fourier modes is performed. The numerical analysis is restricted to nonrelativistic flows but otherwise covers a broad range of Mach numbers and jet densities. The numerical results are used along with the analytical results to obtain accurate expressions for resonant frequencies, wavelengths, and growth rates as a function of Mach numnber and jet density. In all cases the fastest spatial growth rate at a given frequency is of harmonic components associated with the fundamental solution of one of the nonaxisymmetric Fourier modes. The application of these results to jet structure and implication of these results for jet structure in extragalactic radio sources are considered. 23 references

Gyrokinetic Stability Studies of the Microtearing Mode in the National Spherical Torus Experiment H-mode

International Nuclear Information System (INIS)

Baumgaertel J.A., Redi M.H., Budny R.V., Rewoldt G., Dorland W.

2005-01-01

Insight into plasma microturbulence and transport is being sought using linear simulations of drift waves on the National Spherical Torus Experiment (NSTX), following a study of drift wave modes on the Alcator C-Mod Tokamak. Microturbulence is likely generated by instabilities of drift waves, which cause transport of heat and particles. Understanding this transport is important because the containment of heat and particles is required for the achievement of practical nuclear fusion. Microtearing modes may cause high heat transport through high electron thermal conductivity. It is hoped that microtearing will be stable along with good electron transport in the proposed low collisionality International Thermonuclear Experimental Reactor (ITER). Stability of the microtearing mode is investigated for conditions at mid-radius in a high density NSTX high performance (H-mode) plasma, which is compared to the proposed ITER plasmas. The microtearing mode is driven by the electron temperature gradient, and believed to be mediated by ion collisions and magnetic shear. Calculations are based on input files produced by TRXPL following TRANSP (a time-dependent transport analysis code) analysis. The variability of unstable mode growth rates is examined as a function of ion and electron collisionalities using the parallel gyrokinetic computational code GS2. Results show the microtearing mode stability dependence for a range of plasma collisionalities. Computation verifies analytic predictions that higher collisionalities than in the NSTX experiment increase microtearing instability growth rates, but that the modes are stabilized at the highest values. There is a transition of the dominant mode in the collisionality scan to ion temperature gradient character at both high and low collisionalities. The calculations suggest that plasma electron thermal confinement may be greatly improved in the low-collisionality ITER

Effects of the finite pressure of plasma on internal kink mode

International Nuclear Information System (INIS)

Oliveira, G.M.G. de.

1980-01-01

The objective of this work is to study the stability of the Internal Kink and Central Kink modes in ideal MHD cylindrical plasma due to the pressure variations and the different current profiles. It was used the σ Euler equation derived by Goedbloed and Sakanaka. Its analysis is based on the boundary layer method, where the effects due to the plasma inertia are only considered in a boundary layer in the neighborhood of the surface where the perturbation is parallel to the field lines. For the internal Kink mode a numerical analysis is also done by integrating the Euler equation. It was calculated the growth rate of the two modes for the different pressure ans current profiles. It was verified that for both, the Internal Kink and Central Kink modes, the growth rate becomes larger as the derivative of these profiles increases. However, for the Internal Kink mode, one obtains a reduction of up to 50% in the growth rate calculated by Rosenbluth et al. For the Central Kink mode, one notices that the growth rate is proportional to β of the plasma and to the derivatives of the pressure and current. (author) [pt

3D reconnection due to oblique modes: a simulation of Harris current sheets

Directory of Open Access Journals (Sweden)

G. Lapenta

2000-01-01

Full Text Available Simulations in three dimensions of a Harris current sheet with mass ratio, mi/me = 180, and current sheet thickness, pi/L = 0.5, suggest the existence of a linearly unstable oblique mode, which is independent from either the drift-kink or the tearing instability. The new oblique mode causes reconnection independently from the tearing mode. During the initial linear stage, the system is unstable to the tearing mode and the drift kink mode, with growth rates that are accurately described by existing linear theories. How-ever, oblique modes are also linearly unstable, but with smaller growth rates than either the tearing or the drift-kink mode. The non-linear stage is first reached by the drift-kink mode, which alters the initial equilibrium and leads to a change in the growth rates of the tearing and oblique modes. In the non-linear stage, the resulting changes in magnetic topology are incompatible with a pure tearing mode. The oblique mode is shown to introduce a helical structure into the magnetic field lines.

A Minimal Model to Explore the Influence of Distant Modes on Mode-Coupling Instabilities

Science.gov (United States)

Kruse, Sebastian; Hoffmann, Norbert

2010-09-01

The phenomenon of mode-coupling instability is one of the most frequently explored mechanisms to explain self-excited oscillation in sliding systems with friction. A mode coupling instability is usually due to the coupling of two modes. However, further modes can have an important influence on the coupling of two modes. This work extends a well-known minimal model to describe mode-coupling instabilities in order to explore the influence of a distant mode on the classical mode-coupling pattern. This work suggests a new minimal model. The model is explored and it is shown that a third mode can have significant influence on the classical mode-coupling instabilities where two modes are coupling. Different phenomena are analysed and it is pointed out that distant modes can only be ignored in very special cases and that the onset friction-induced oscillations can even be very sensitive to minimal variation of a distant mode. Due to the chosen academic minimal-model and the abandonment of a complex Finite-Element model the insight stays rather phenomenological but a better understanding of the mode-coupling mechnanism can be gained.

Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

International Nuclear Information System (INIS)

Yeh, J-R; Lin, T-Y; Shieh, J-S; Chen, Y; Huang, N E; Wu, Z; Peng, C-K

2008-01-01

In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven

Investigating complex patterns of blocked intestinal artery blood pressure signals by empirical mode decomposition and linguistic analysis

Energy Technology Data Exchange (ETDEWEB)

Yeh, J-R; Lin, T-Y; Shieh, J-S [Department of Mechanical Engineering, Yuan Ze University, 135 Far-East Road, Chung-Li, Taoyuan, Taiwan (China); Chen, Y [Far Eastern Memorial Hospital, Taiwan (China); Huang, N E [Research Center for Adaptive Data Analysis, National Central University, Taiwan (China); Wu, Z [Center for Ocean-Land-Atmosphere Studies (United States); Peng, C-K [Beth Israel Deaconess Medical Center, Harvard Medical School (United States)], E-mail: s939205@ mail.yzu.edu.tw

2008-02-15

In this investigation, surgical operations of blocked intestinal artery have been conducted on pigs to simulate the condition of acute mesenteric arterial occlusion. The empirical mode decomposition method and the algorithm of linguistic analysis were applied to verify the blood pressure signals in simulated situation. We assumed that there was some information hidden in the high-frequency part of the blood pressure signal when an intestinal artery is blocked. The empirical mode decomposition method (EMD) has been applied to decompose the intrinsic mode functions (IMF) from a complex time series. But, the end effects and phenomenon of intermittence damage the consistence of each IMF. Thus, we proposed the complementary ensemble empirical mode decomposition method (CEEMD) to solve the problems of end effects and the phenomenon of intermittence. The main wave of blood pressure signals can be reconstructed by the main components, identified by Monte Carlo verification, and removed from the original signal to derive a riding wave. Furthermore, the concept of linguistic analysis was applied to design the blocking index to verify the pattern of riding wave of blood pressure using the measurements of dissimilarity. Blocking index works well to identify the situation in which the sampled time series of blood pressure signal was recorded. Here, these two totally different algorithms are successfully integrated and the existence of the existence of information hidden in high-frequency part of blood pressure signal has been proven.

Resolving the Complex Genetic Basis of Phenotypic Variation and Variability of Cellular Growth.

Science.gov (United States)

Ziv, Naomi; Shuster, Bentley M; Siegal, Mark L; Gresham, David

2017-07-01

In all organisms, the majority of traits vary continuously between individuals. Explaining the genetic basis of quantitative trait variation requires comprehensively accounting for genetic and nongenetic factors as well as their interactions. The growth of microbial cells can be characterized by a lag duration, an exponential growth phase, and a stationary phase. Parameters that characterize these growth phases can vary among genotypes (phenotypic variation), environmental conditions (phenotypic plasticity), and among isogenic cells in a given environment (phenotypic variability). We used a high-throughput microscopy assay to map genetic loci determining variation in lag duration and exponential growth rate in growth rate-limiting and nonlimiting glucose concentrations, using segregants from a cross of two natural isolates of the budding yeast, Saccharomyces cerevisiae We find that some quantitative trait loci (QTL) are common between traits and environments whereas some are unique, exhibiting gene-by-environment interactions. Furthermore, whereas variation in the central tendency of growth rate or lag duration is explained by many additive loci, differences in phenotypic variability are primarily the result of genetic interactions. We used bulk segregant mapping to increase QTL resolution by performing whole-genome sequencing of complex mixtures of an advanced intercross mapping population grown in selective conditions using glucose-limited chemostats. We find that sequence variation in the high-affinity glucose transporter HXT7 contributes to variation in growth rate and lag duration. Allele replacements of the entire locus, as well as of a single polymorphic amino acid, reveal that the effect of variation in HXT7 depends on genetic, and allelic, background. Amplifications of HXT7 are frequently selected in experimental evolution in glucose-limited environments, but we find that HXT7 amplifications result in antagonistic pleiotropy that is absent in naturally

Simulation and modeling of whistler-mode wave growth through cyclotron resonance with energetic electrons in the magnetosphere

International Nuclear Information System (INIS)

Carlson, C.R.

1987-01-01

New models and simulations of wave growth experienced by electromagnetic waves propagating through the magnetosphere in the whistler mode are presented. For these waves, which have frequencies below the electron gyro and plasma frequencies, the magnetospheric plasma acts like a natural amplifier often amplifying the waves by ∼ 30 dB. The mechanism for growth is cyclotron resonance between the circularly polarized waves and the gyrating energetic electrons which make up the Van Allen radiation belts. The main emphasis is to simulate single-frequency wave pulses, in the 2-6 kHz range, that have been injected into the magnetosphere, near L ∼ 4, by the Stanford transmitting facility at Siple station, Antarctica. However, the results can also be applied to naturally occurring signals, signals from other transmitters, non-CW signals, and signals in other parts of the magnetosphere not probed by the Siple Station transmitter. Results show the importance of the transient aspects in the wave-growth process. The wave growth established as the wave propagates toward the equator, is given a spatially advancing wave phase structure by the geomagnetic inhomogeneity. Through the feedback of this radiation upon other electrons, conditions are set up that results in the linearly increasing output frequency with time

'In-Crystallo' Capture of a Michaelis Complex And Product Binding Modes of a Bacterial Phosphotriesterase

Energy Technology Data Exchange (ETDEWEB)

Jackson, C.J.; Foo, J.-L.; Kim, H.-K.; Carr, P.D.; Liu, J.-W.; Salem, G.; Ollis, D.L.

2009-05-18

The mechanism by which the binuclear metallophosphotriesterases (PTEs, E.C. 3.1.8.1) catalyse substrate hydrolysis has been extensively studied. The {mu}-hydroxo bridge between the metal ions has been proposed to be the initiating nucleophile in the hydrolytic reaction. In contrast, analysis of some biomimetic systems has indicated that {mu}-hydroxo bridges are often not themselves nucleophiles, but act as general bases for freely exchangeable nucleophilic water molecules. Herein, we present crystallographic analyses of a bacterial PTE from Agrobacterium radiobacter, OpdA, capturing the enzyme-substrate complex during hydrolysis. This model of the Michaelis complex suggests the alignment of the substrate will favor attack from a solvent molecule terminally coordinated to the {alpha}-metal ion. The bridging of both metal ions by the product, without disruption of the {mu}-hydroxo bridge, is also consistent with nucleophilic attack occurring from the terminal position. When phosphodiesters are soaked into crystals of OpdA, they coordinate bidentately to the {beta}-metal ion, displacing the {mu}-hydroxo bridge. Thus, alternative product-binding modes exist for the PTEs, and it is the bridging mode that appears to result from phosphotriester hydrolysis. Kinetic analysis of the PTE and promiscuous phosphodiesterase activities confirms that the presence of a {mu}-hydroxo bridge during phosphotriester hydrolysis is correlated with a lower pK{sub a} for the nucleophile, consistent with a general base function during catalysis.

Rippling modes in the edge of a tokamak plasma

International Nuclear Information System (INIS)

Carreras, B.A.; Callen, J.D.; Gaffney, P.W.; Hicks, H.R.

1982-02-01

A promising resistive magnetohydrodynamic candidate for the underlying cause of turbulence in the edge of a tokamak plasma is the rippling instability. In this paper we develop a computational model for these modes in the cylindrical tokamak approximation and explore the linear growth and single-helicity quasi-linear saturation phases of the rippling modes for parameters appropriate to the edge of a tokamak plasma. Large parallel heat conduction does not stabilize these modes; it only reduces their growth rate by a factor scaling as k/sub parallel//sup -4/3/. Nonlinearly, individual rippling modes are found to saturate by quasi-linear flattening of the resistivity profile. The saturated amplitude of the modes scales as m/sup -1/, and the radial extent of these modes grows linearly with time due to radial Vector E x Vector B 0 convection. This evolution is found to be terminated by parallel heat conduction

Rippling modes in the edge of a tokamak plasma

International Nuclear Information System (INIS)

Carreras, B.A.; Gaffney, P.W.; Hicks, H.R.; Callan, J.D.

1982-01-01

A promising resistive magnetohydrodynamic candidate for the underlying cause of turbulence in the edge of a tokamak plasma is the rippling instability. In this paper a computational model for these modes in the cylindrical tokamak approximation was developed and the linear growth and single-helicity quasi-linear saturation phases of the rippling modes for parameters appropriate to the edge of a tokamak plasma were explored. Large parallel heat conduction does not stabilize these modes; it only reduces their growth rate by a factor sacling as K/sup -4/3//sub parallel/. Nonlinearly, individual rippling modes are found to saturate by quasi-linear flattening of the resistivity profile. The saturated amplitude of the modes scales as m -1 , and the radial extent of these modes grows linearly with time due to radial E x B 0 convection. This evolution is found to be terminated by parallel heat conduction

Analytic theory of the nonlinear M = 1 tearing mode

International Nuclear Information System (INIS)

Hazeltine, R.D.; Meiss, J.D.; Morrison, P.J.

1985-09-01

Numerical studies show that the m = 1 tearing mode continues to grow exponentially well into the nonlinear regime, in contrast with the slow, ''Rutherford,'' growth of m > 1 modes. We present a single helicity calculation which generalizes that of Rutherford to the case when the constant-psi approximation is invalid. As in that theory, the parallel current becomes an approximate flux function when the island size, W, exceeds the linear tearing layer width. However for the m = 1 mode, W becomes proportional to deltaB, rather than (deltaB)/sup 1/2/ above this critical amplitude. This implies that the convective nonlinearity in Ohm's law, which couples the m = 0 component to the m = 1 component, dominates the resistive diffusion term. The balance between the inductive electric field and this convective nonlinearity results in exponential growth. Assuming the form of the perturbed fields to be like that of the linear mode, we find that the growth occurs at 71% of the linear rate

Comparison of dielectric barrier discharge modes fungicidal effect on candida albicans growth

International Nuclear Information System (INIS)

Slama, J.; Kriha, V.; Fantova, V.; Julak, J.

2013-01-01

Filamentary and quasi-homogeneous mode of dielectric barrier discharge (DBD) was investigated as a plasma source with fungicidal effect on Candida albicans yeast inoculated on Sabouraud agar wafers. As compared with the filamentary DBD mode, the quasi-homogeneous mode had significantly better results: shorter exposition time needed for inhibiting C. albicans yeast, moreover the quasi-homogeneous mode had gentle influence on the agar surface structure.

Quasinormal-Mode Expansion of the Scattering Matrix

Directory of Open Access Journals (Sweden)

Filippo Alpeggiani

2017-06-01

Full Text Available It is well known that the quasinormal modes (or resonant states of photonic structures can be associated with the poles of the scattering matrix of the system in the complex-frequency plane. In this work, the inverse problem, i.e., the reconstruction of the scattering matrix from the knowledge of the quasinormal modes, is addressed. We develop a general and scalable quasinormal-mode expansion of the scattering matrix, requiring only the complex eigenfrequencies and the far-field properties of the eigenmodes. The theory is validated by applying it to illustrative nanophotonic systems with multiple overlapping electromagnetic modes. The examples demonstrate that our theory provides an accurate first-principles prediction of the scattering properties, without the need for postulating ad hoc nonresonant channels.

Univariate and Bivariate Empirical Mode Decomposition for Postural Stability Analysis

Directory of Open Access Journals (Sweden)

Jacques Duchêne

2008-05-01

Full Text Available The aim of this paper was to compare empirical mode decomposition (EMD and two new extended methods of  EMD named complex empirical mode decomposition (complex-EMD and bivariate empirical mode decomposition (bivariate-EMD. All methods were used to analyze stabilogram center of pressure (COP time series. The two new methods are suitable to be applied to complex time series to extract complex intrinsic mode functions (IMFs before the Hilbert transform is subsequently applied on the IMFs. The trace of the analytic IMF in the complex plane has a circular form, with each IMF having its own rotation frequency. The area of the circle and the average rotation frequency of IMFs represent efficient indicators of the postural stability status of subjects. Experimental results show the effectiveness of these indicators to identify differences in standing posture between groups.

Tearing mode instability due to anomalous resistivity

International Nuclear Information System (INIS)

Furuya, Atsushi; Itoh, Sanae I.; Yagi, Masatoshi

2000-01-01

Tearing mode instability in the presence of microscopic truculence is investigates. The effects of microscopic turbulence on tearing mode are taken as drags which are calculated by one-point renormalization method and mean-field approximation. These effects are reduced to effective diffusivities in reduced MHD equations. Using these equations, the stability analyses of the tearing mode are performed. It is shown that a finite amplitude of fluctuation enhances the growth rate of tearing mode. For very high values of turbulent diffusivities, marginally stable state exists. The effects of each turbulent diffusivity on mode stability are examined near marginal stability boundary. Parameter dependence of the resistive ballooning mode turbulence on tearing mode is analyzed as an example. (author)

Topoclimate effects on growing season length and montane conifer growth in complex terrain

Science.gov (United States)

Barnard, D. M.; Barnard, H. R.; Molotch, N. P.

2017-05-01

Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow. We then compared these metrics with stem relative basal area increment (relative BAI) at seven sites among elevation and aspects in a Colorado montane forest. As elevation increased, we found shorter GSL (-50 d km-1) due to later GSstart (40 d km-1) and earlier GSend (-10 d km-1). North-facing sites had a 21 d shorter GSL than south-facing sites at similar elevations (i.e. equal to 200 m elevation difference on a given aspect). Growing season length was positively correlated with relative BAI, explaining 83% of the variance. This study shows that topography exerts strong environmental controls on GSL and thus forest growth. Given the climate-related dependencies of these controls, the results presented here have important implications for ecosystem responses to changes in climate and highlight the need for improved phenology representation in complex terrain.

A bioactive molecule in a complex wound healing process: platelet-derived growth factor.

Science.gov (United States)

Kaltalioglu, Kaan; Coskun-Cevher, Sule

2015-08-01

Wound healing is considered to be particularly important after surgical procedures, and the most important wounds related to surgical procedures are incisional, excisional, and punch wounds. Research is ongoing to identify methods to heal non-closed wounds or to accelerate wound healing; however, wound healing is a complex process that includes many biological and physiological events, and it is affected by various local and systemic factors, including diabetes mellitus, infection, ischemia, and aging. Different cell types (such as platelets, macrophages, and neutrophils) release growth factors during the healing process, and platelet-derived growth factor is a particularly important mediator in most stages of wound healing. This review explores the relationship between platelet-derived growth factor and wound healing. © 2014 The International Society of Dermatology.

Spatial light modulation for mode conditioning

DEFF Research Database (Denmark)

Glückstad, Jesper; Palima, Darwin

We demonstrate patented techniques for generating tuneable complex field distributions for controllable coupling to high-order guided modes of micro-structured fibres. The optical Fourier transform of binary phase-only patterns which are encoded on a computer-controlled spatial light modulator......, generates complex field distributions for selective launching of a desired mode. Both the amplitude and the phase of the programmable fields are modulated by straightforward and fast adjustments of simple pre-defined binary phase-only diffractive patterns. Experiments demonstrate tuneable coupling...

Stability of longitudinal modes in a bunched beam with mode coupling

International Nuclear Information System (INIS)

Satoh, K.

1981-06-01

In this paper we study a longitudinal coherent bunch instability in which the growth time is comparable to or less than the period of synchrotron oscillations. Both longitudinal and transverse bunch instabilities have been studied. In most treatments, however, the coherent force is assumed to be small and is treated as a perturbation compared with the synchrotron force. This makes the problem simpler because an individual synchrotron mode is decoupled. As bunch current increases, the coherent force is no longer small and the mode frequency shift becomes significant compared with the synchrotron frequency. Therefore in this case it is necessary to include coupling of the synchrotron modes. Recently a fast blow-up instability which comes from mode coupling was studied. Their method is to derive a dispersion relation for a bunched beam using the Vlasov equation and to analyze it as in a coasting beam. They showed that if mode coupling is included the Vlasov equation predicts a fast microwave instability with a stability condition similar to that for a coasting beam. In this paper we will partly follow their method and present a formalism which includes coupling between higher-order radial modes as well as coupling between synchrotron modes. The formalism is considered to be generalization of the Sacherer formalism without mode coupling. This theory predicts that instability is induced not only by coupling between different synchrotron modes, but also by coupling between positive and negative modes, since negative synchrotron modes are included in the theory in a natural manner. This formalism is to be used for a Gaussian bunch and a parabolic bunch, and is also useful for transverse problems

A two-fluid study of oblique tearing modes in a force-free current sheet

Energy Technology Data Exchange (ETDEWEB)

Akçay, Cihan, E-mail: akcay@lanl.gov; Daughton, William [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lukin, Vyacheslav S. [National Science Foundation, Arlington, Virginia 22230 (United States); Liu, Yi-Hsin [NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2016-01-15

Kinetic simulations have demonstrated that three-dimensional reconnection in collisionless regimes proceeds through the formation and interaction of magnetic flux ropes, which are generated due to the growth of tearing instabilities at multiple resonance surfaces. Since kinetic simulations are intrinsically expensive, it is desirable to explore the feasibility of reduced two-fluid models to capture this complex evolution, particularly, in the strong guide field regime, where two-fluid models are better justified. With this goal in mind, this paper compares the evolution of the collisionless tearing instability in a force-free current sheet with a two-fluid model and fully kinetic simulations. Our results indicate that the most unstable modes are oblique for guide fields larger than the reconnecting field, in agreement with the kinetic results. The standard two-fluid tearing theory is extended to address the tearing instability at oblique angles. The resulting theory yields a flat oblique spectrum and underestimates the growth of oblique modes in a similar manner to kinetic theory relative to kinetic simulations.

The basic route of the nuclear translocation porcine growth hormone (GH)-growth hormone receptor (GHR) complex (pGH/GHR) in porcine hepatocytes.

Science.gov (United States)

Hainan, Lan; Huilin, Liu; Khan, Mahamad; Xin, Zheng; YuJiang, Yang; Hui, Zhang; Naiquan, Yao

2018-06-08

Traditional views suggest that growth hormone and the growth hormone receptor (GH/GHR complex) exert their functions only on the plasma membrane. This paradigm, however, has been challenged by recent new findings that the GH/GHR complex could translocate into cell nuclei where they could still exhibit important physiological functions. We also reported the nuclear localization of porcine GH/GHR and their potential functions in porcine hepatocytes. However, the basic path of pGH/GHR's nuclear translocation remains unclear. Combining previous research results and our current findings, we proposed two basic routes of pGH/GHR's nuclear transportation as follows: 1) after pGH binding to GHR, pGH/GHR enters into the cytoplasm though clathrin- or caveolin-mediated endocytosis, then the pGH/GHR complex enters into early endosomes (Rab5-positive), and the endosome carries the GH/GHR complex to the endoplasmic reticulum (ER). After endosome docking on the ER, the endosome starts fission, and the pGH/GHR complex enters into the ER lumen. Then the pGH/GHR complex transports into the cytoplasm, possibly by the ERAD pathway. Subsequently, the pGH/GHR complex interacts with IMPα/β, which, in turn, mediates GH/GHR nuclear localization; 2) pGH binds with the GHR on the cell membrane and, subsequently, pGH/GHR internalizes into the cell and enters into the endosome (this endosome may belong to a class of endosomes called envelope-associated endosomes (NAE)). Then, the endosome carries the pGH/GHR to the nuclear membrane. After docking on the nuclear membrane, the pGH/GHR complex fuses with the nuclear membrane and then enters into the cell nucleus. Copyright © 2018 Elsevier Inc. All rights reserved.

Stochastic modeling of mode interactions via linear parabolized stability equations

Science.gov (United States)

Ran, Wei; Zare, Armin; Hack, M. J. Philipp; Jovanovic, Mihailo

2017-11-01

Low-complexity approximations of the Navier-Stokes equations have been widely used in the analysis of wall-bounded shear flows. In particular, the parabolized stability equations (PSE) and Floquet theory have been employed to capture the evolution of primary and secondary instabilities in spatially-evolving flows. We augment linear PSE with Floquet analysis to formally treat modal interactions and the evolution of secondary instabilities in the transitional boundary layer via a linear progression. To this end, we leverage Floquet theory by incorporating the primary instability into the base flow and accounting for different harmonics in the flow state. A stochastic forcing is introduced into the resulting linear dynamics to model the effect of nonlinear interactions on the evolution of modes. We examine the H-type transition scenario to demonstrate how our approach can be used to model nonlinear effects and capture the growth of the fundamental and subharmonic modes observed in direct numerical simulations and experiments.

Phylogenetic investigation of the complex evolutionary history of dispersal mode and diversification rates across living and fossil Fagales.

Science.gov (United States)

Larson-Johnson, Kathryn

2016-01-01

As a primary determinant of spatial structure in angiosperm populations, fruit dispersal may impact large-scale ecological and evolutionary processes. Essential to understanding these mechanisms is an accurate reconstruction of dispersal mode over the entire history of an angiosperm lineage. A total-evidence phylogeny is presented for most fossil fruit and all extant genera in Fagales over its c. 95 million yr history. This phylogeny - the largest of its kind to include plant fossils - was used to reconstruct an evolutionary history directly informed by fossil morphologies and to assess relationships among dispersal mode, biogeographic range size, and diversification rate. Reconstructions indicate four transitions to wind dispersal and seven to biotic dispersal, with the phylogenetic integration of fossils crucial to understanding these patterns. Complexity further increased when more specialized behaviors were considered, with fluttering, gliding, autorotating, and scatter-hoarding evolving multiple times across the order. Preliminary biogeographic analyses suggest larger range sizes in biotically dispersed lineages, especially when pollination mode was held constant. Biotically dispersed lineages had significantly higher diversification rates than abiotically dispersed lineages, although transitions in dispersal mode alone cannot explain all detected diversification rate shifts across Fagales. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Planktonic growth and biofilm formation profiles in Candida haemulonii species complex.

Science.gov (United States)

Ramos, Lívia S; Oliveira, Simone S C; Souto, Xênia M; Branquinha, Marta H; Santos, André L S

2017-10-01

Candida haemulonii species complex have emerged as multidrug-resistant yeasts able to cause fungemia worldwide. However, very little is known regarding their physiology and virulence factors. In this context, planktonic growth and biofilm formation of Brazilian clinical isolates of Candida haemulonii (n = 5), Candida duobushaemulonii (n = 4), and Candida haemulonii var. vulnera (n = 3) were reported. Overall, the fungal planktonic growth curves in Sabouraud dextrose broth reached the exponential phase in 48 h at 37°C. All the clinical isolates formed biofilm on polystyrene in a time-dependent event, as judged by the parameters evaluated: biomass (crystal violet staining), metabolic activity (XTT reduction), and extracellular matrix (safranin incorporation). No statistically significant differences were observed when the average measurements among the three Candida species were compared regarding both planktonic and biofilm lifestyles; however, typical isolate-specific differences were clearly noticed in fungal growth kinetics. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Tris-amidoximate uranyl complexes via η2 binding mode coordinated in aqueous solution shown by X-ray absorption spectroscopy and density functional theory methods.

Science.gov (United States)

Zhang, Linjuan; Qie, Meiying; Su, Jing; Zhang, Shuo; Zhou, Jing; Li, Jiong; Wang, Yu; Yang, Shitong; Wang, Shuao; Li, Jingye; Wu, Guozhong; Wang, Jian Qiang

2018-03-01

The present study sheds some light on the long-standing debate concerning the coordination properties between uranyl ions and the amidoxime ligand, which is a key ingredient for achieving efficient extraction of uranium. Using X-ray absorption fine structure combined with theoretical simulation methods, the binding mode and bonding nature of a uranyl-amidoxime complex in aqueous solution were determined for the first time. The results show that in a highly concentrated amidoxime solution the preferred binding mode between UO 2 2+ and the amidoxime ligand is η 2 coordination with tris-amidoximate species. In such a uranyl-amidoximate complex with η 2 binding motif, strong covalent interaction and orbital hybridization between U 5f/6d and (N, O) 2p should be responsible for the excellent binding ability of the amidoximate ligand to uranyl. The study was performed directly in aqueous solution to avoid the possible binding mode differences caused by crystallization of a single-crystal sample. This work also is an example of the simultaneous study of local structure and electronic structure in solution systems using combined diagnostic tools.

Fatigue crack growth in mode II of adhesively joined composites

DEFF Research Database (Denmark)

Biel, Anders; Toftegaard, Helmuth Langmaack

2017-01-01

, experiments are performed to derive material data for a crack propagation in shear i.e. in mode II. The shear loading of the crack is achieved by use of double cantilever beam specimens loaded with uneven bending moments. The experiments are performed under a constant cyclic displacement. An initial mode I...... loading is used to make the crack start in the adhesive. The crack length is measured using a load synchronized camera. Due to the shear loading the crack deviates from the adhesive layer into the laminate. A stable crack propagation is detected in the laminate. No influence have been detected due...... to an increasing crack length. It is also observed that the crack is trapped in the laminate; if the loading is changed to mode I the crack continues to propagate in the laminate....

Hydrothermal growth of cross-linked hyperbranched copper dendrites using copper oxalate complex

Science.gov (United States)

Truong, Quang Duc; Kakihana, Masato

2012-06-01

A facile and surfactant-free approach has been developed for the synthesis of cross-linked hyperbranched copper dendrites using copper oxalate complex as a precursor and oxalic acid as a reducing and structure-directing agent. The synthesized particles are composed of highly branched nanostructures with unusual cross-linked hierarchical networks. The formation of copper dendrites can be explained in view of both diffusion control and aggregation-based growth model accompanied by the chelation-assisted assembly. Oxalic acid was found to play dual roles as reducing and structure-directing agent based on the investigation results. The understanding on the crystal growth and the roles of oxalic acid provides clear insight into the formation mechanism of hyperbranched metal dendrites.

Exact quantification of the complexity of spacewise pattern growth in cellular automata

International Nuclear Information System (INIS)

Freire, Joana G; Gallas, Jason A C; Brison, Owen J

2009-01-01

We analyze the two possible ways of simulating complex systems with cellular automata: by using the familiar timewise updating or by using the complementary spacewise updating. Both updating algorithms operate on identical sets of initial conditions defining the state of the automaton. While timewise growth generally probes just vanishingly small sets of initial conditions producing statistical samples of the asymptotic attractors, spacewise growth operates with much restricted sets which allow one to simulate them all, exhaustively. Our main result is the derivation of an exact analytical formula to quantify precisely one of the two sources of algorithmic complexity of spacewise detection of the complete set of attractors for elementary 1D cellular automata with generic non-periodic architectures of any arbitrary size. The formula gives the total number of initial conditions that need to be investigated to locate rigorously all possible patterns for any given rule. As simple applications, we illustrate how this knowledge may be used (i) to uncover missing patterns in previous classifications in the literature and (ii) to obtain surprisingly novel patterns that are totally unreachable with the time-honored technique of artificially imposing spatially periodic boundary conditions.

Effects of resonant magnetic perturbation on the triggering and the evolution of double-tearing mode

Science.gov (United States)

Wang, L.; Lin, W. B.; Wang, X. Q.

2018-02-01

The effects of resonant magnetic perturbation on the triggering and the evolution of the double-tearing mode are investigated by using nonlinear magnetohydrodynamics simulations in a slab geometry. It is found that the double-tearing mode can be destabilized by boundary magnetic perturbation. Moreover, the mode has three typical development stages before it reaches saturation: the linear stable stage, the linear-growth stage, and the exponential-growth stage. The onset and growth of the double-tearing mode significantly depend on the boundary magnetic perturbations, particularly in the early development stage of the mode. The influences of the magnetic perturbation amplitude on the mode for different separations of the two rational surfaces are also discussed.

Radiation-induced ηe-modes

International Nuclear Information System (INIS)

Shukla, P.K.; Yu, M.Y.

1990-01-01

Impurity radiation in a plasma can cause not only static instabilities, but also dynamic instabilities related to the drift and acoustic waves. Radiative instabilities are of much interest because they are associated with relatively high frequency and short wavelength fluctuations, which have been suspected to be responsible for anomalous electron energy transport in tokamak edge plasmas. In this paper, we consider radiation-induced η e instabilities, taking into account electrostatic effects as well as density and temperature inhomogeneities. Also included are the effects of finite gyroradius and dissipation. It is found that the latter can cause strong linear coupling between the modes of interest. The resulting instabilities can have larger growth rates than the static radiative instability. Analytical expressions for the growth rates and instability regimes are given for the limiting cases of practical interest. In particular, it is shown that the η e -mode can couple to both radiation and dissipation to cause resistive instabilities. The parameter regimes of the original radiative as well as the dissipative modes are thereby broadened and shifted because of the interaction. (author) 3 refs

The Impact of Services on Economic Complexity: Service Sophistication as Route for Economic Growth.

Science.gov (United States)

Stojkoski, Viktor; Utkovski, Zoran; Kocarev, Ljupco

2016-01-01

Economic complexity reflects the amount of knowledge that is embedded in the productive structure of an economy. By combining tools from network science and econometrics, a robust and stable relationship between a country's productive structure and its economic growth has been established. Here we report that not only goods but also services are important for predicting the rate at which countries will grow. By adopting a terminology which classifies manufactured goods and delivered services as products, we investigate the influence of services on the country's productive structure. In particular, we provide evidence that complexity indices for services are in general higher than those for goods, which is reflected in a general tendency to rank countries with developed service sector higher than countries with economy centred on manufacturing of goods. By focusing on country dynamics based on experimental data, we investigate the impact of services on the economic complexity of countries measured in the product space (consisting of both goods and services). Importantly, we show that diversification of service exports and its sophistication can provide an additional route for economic growth in both developing and developed countries.

Tearing mode saturation with finite pressure

International Nuclear Information System (INIS)

Lee, J.K.

1988-01-01

With finite pressure, the saturation of the current-driven tearing mode is obtained in three-dimensional nonlinear resistive magnetohydrodynamic simulations for Tokamak plasmas. To effectively focus on the tearing modes, the perturbed pressure effects are excluded while the finite equilibrium pressure effects are retained. With this model, the linear growth rates of the tearing modes are found to be very insensitive to the equilibrium pressure increase. The nonlinear aspects of the tearing modes, however, are found to be very sensitive to the pressure increase in that the saturation level of the nonlinear harmonics of the tearing modes increases monotonically with the pressure rise. The increased level is associated with enhanced tearing island sizes or increased stochastic magnetic field region. (author)

Sound modes in hot nuclear matter

International Nuclear Information System (INIS)

Kolomietz, V. M.; Shlomo, S.

2001-01-01

The propagation of the isoscalar and isovector sound modes in a hot nuclear matter is considered. The approach is based on the collisional kinetic theory and takes into account the temperature and memory effects. It is shown that the sound velocity and the attenuation coefficient are significantly influenced by the Fermi surface distortion (FSD). The corresponding influence is much stronger for the isoscalar mode than for the isovector one. The memory effects cause a nonmonotonous behavior of the attenuation coefficient as a function of the relaxation time leading to a zero-to-first sound transition with increasing temperature. The mixing of both the isoscalar and the isovector sound modes in an asymmetric nuclear matter is evaluated. The condition for the bulk instability and the instability growth rate in the presence of the memory effects is studied. It is shown that both the FSD and the relaxation processes lead to a shift of the maximum of the instability growth rate to the longer-wavelength region

Toroidal coupling and frequency spectrum of tearing modes

International Nuclear Information System (INIS)

Edery, D.; Samain, A.

1989-05-01

The frequency spectrum of tearing modes is analyzed with the help of a mode coupling model including toroidal effects in the MHD regions and various non linear effects in the resonant layers. In particular it is shown that the sudden damping of the mode rotation and the simultaneous enhancement of the growth rate observed in tokamak, could be explained as a bifurcating solution of the dispersion equation

Structure of calmodulin complexed with an olfactory CNG channel fragment and role of the central linker: Residual dipolar couplings to evaluate calmodulin binding modes outside the kinase family

International Nuclear Information System (INIS)

Contessa, Gian Marco; Orsale, Maria; Melino, Sonia; Torre, Vincent; Paci, Maurizio; Desideri, Alessandro; Cicero, Daniel O.

2005-01-01

The NMR high-resolution structure of calmodulin complexed with a fragment of the olfactory cyclic-nucleotide gated channel is described. This structure shows features that are unique for this complex, including an active role of the linker connecting the N- and C-lobes of calmodulin upon binding of the peptide. Such linker is not only involved in the formation of an hydrophobic pocket to accommodate a bulky peptide residue, but it also provides a positively charged region complementary to a negative charge of the target. This complex of calmodulin with a target not belonging to the kinase family was used to test the residual dipolar coupling (RDC) approach for the determination of calmodulin binding modes to peptides. Although the complex here characterized belongs to the (1--14) family, high Q values were obtained with all the 1:1 complexes for which crystalline structures are available. Reduction of the RDC data set used for the correlation analysis to structured regions of the complex allowed a clear identification of the binding mode. Excluded regions comprise calcium binding loops and loops connecting the EF-hand motifs

Mode-mode coupling theory of itinerant electron antiferromagnetism in superconducting state

International Nuclear Information System (INIS)

Fujimoto, Yukinobu; Miyake, Kazumasa

2012-01-01

It has been considered since the first discovery of a high-T c cuprate that an antiferromagnetic (AF) state and a superconducting (SC) state are separated in it. However, it is very intriguing that the coexistence of the AF and SC states has recently been observed in HgBa 2 Ca 4 Cu 5 O 12+ (Hg-1245). Moreover, it is very novel that this coexistence of these two states appears if the SC-transition temperature T c is higher than the AF-transition temperature T N . The mode-mode coupling theory can provide a clear elucidation of this novel phenomenon. A key point of this theory is that the AF susceptibility consists of the random-phase-approximation (RPA) term and the mode-mode coupling one. The RPA term works to make a positive contribution to the emergence of the antiferromagnetic critical point (AF-CP). In contrast, the mode-mode coupling term works to make a negative contribution to the emergence of the AF-CP. However, the growth of the SC-gap function in the d x 2 -y 2 -wave SC state works to suppress the negative contribution of the mode-mode coupling term to the emergence of the AF-CP. Moreover, the effect of SC fluctuations near the SC-transition temperature T c suppresses the mode-mode coupling term of the AF susceptibility that works to hinder the AF ordering. For these two reasons, there is a possibility that the d x 2 -y 2 -wave SC state is likely to promote the emergence of the AF-CP. Namely, the appearance of the above-mentioned novel coexistence of the AF and SC states observed in Hg-1245 can be explained qualitatively on the basis of this idea.

Nonlinear growth of strongly unstable tearing modes

International Nuclear Information System (INIS)

Waelbroeck, F.L.

1993-11-01

Rutherford's theory of the tearing instability is extended to cases where current nonlinearities are important, such as long wavelength modes in current slabs and the m = 1 instability in tokamaks with moderately large aspect-ratios. Of particular interest is the possibility that the associated magnetic islands, as a result of secondary instabilities, have a singular response to the Ohmic diffusion of the current. A family of islands is used to test this possibility; it is found that the response remains bounded

In situ doping of catalyst-free InAs nanowires with Si: Growth, polytypism, and local vibrational modes of Si

Energy Technology Data Exchange (ETDEWEB)

Dimakis, Emmanouil; Ramsteiner, Manfred; Huang, Chang-Ning; Trampert, Achim; Riechert, Henning; Geelhaar, Lutz [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany); Davydok, Anton; Biermanns, Andreas; Pietsch, Ullrich [Festkörperphysik, Universität Siegen, Walter-Flex-Str. 3, 57072 Siegen (Germany)

2013-09-30

Growth and structural aspects of the in situ doping of InAs nanowires with Si have been investigated. The nanowires were grown catalyst-free on Si(111) substrates by molecular beam epitaxy. The supply of Si influenced the growth kinetics, affecting the nanowire dimensions, but not the degree of structural polytypism, which was always pronounced. As determined by Raman spectroscopy, Si was incorporated as substitutional impurity exclusively on In sites, which makes it a donor. Previously unknown Si-related Raman peaks at 355 and 360 cm{sup −1} were identified, based on their symmetry properties in polarization-dependent measurements, as the two local vibrational modes of an isolated Si impurity on In site along and perpendicular, respectively, to the c-axis of the wurtzite InAs crystal.

Position-dependent deuterium isotope effect on photoisomerization of ammineaquarhodium(III) complexes: identification of the excited-state vibronic deactivation mode

International Nuclear Information System (INIS)

Skibsted, L.H.

1987-01-01

cis to trans Photoisomerization quantum yields are increased by a factor of approximately two by deuteriation of co-ordinated water in tetra-amminediaquarhodium, but are almost insensitive to deuteriation of co-ordinated water in tetra-ammineaquachlororhodium and to deuteriation of co-ordinated ammonia in either complex; this identifies the dominating nonradiative deactivation mode (competing with the excited-state rearrangement) as a hydrogen-oxygen vibration in an excited-state intermediate of reduced co-ordination number. (author)

Correlations between locked modes and impurity influxes

Energy Technology Data Exchange (ETDEWEB)

Fishpool, G M [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Lawson, K D [UKAEA Culham Lab., Abingdon (United Kingdom)

1994-07-01

An analysis of pulses that were disturbed by medium Z impurity influxes (Cl, Cr, Fe and Ni) recorded during the 91/92 JET operations, has demonstrated that such influxes can result in MHD modes which subsequently ``lock``. A correlation is found between the power radiated by the influx and the time difference between the start of the influx and the beginning of the locked mode. The growth in the amplitude of the locked mode itself can lead to further impurity influxes. A correlation is noted between intense influxes (superior to 10 MW) and the mode ``unlocking``. (authors). 4 refs., 4 figs.

Bacteria of the Burkholderia cepacia complex are cyanogenic under biofilm and colonial growth conditions

Directory of Open Access Journals (Sweden)

Hoshino Saiko

2008-06-01

Full Text Available Abstract Background The Burkholderia cepacia complex (Bcc is a collection of nine genotypically distinct but phenotypically similar species. They show wide ecological diversity and include species that are used for promoting plant growth and bio-control as well species that are opportunistic pathogens of vulnerable patients. Over recent years the Bcc have emerged as problematic pathogens of the CF lung. Pseudomonas aeruginosa is another important CF pathogen. It is able to synthesise hydrogen cyanide (HCN, a potent inhibitor of cellular respiration. We have recently shown that HCN production by P. aeruginosa may have a role in CF pathogenesis. This paper describes an investigation of the ability of bacteria of the Bcc to make HCN. Results The genome of Burkholderia cenocepacia has 3 putative HCN synthase encoding (hcnABC gene clusters. B. cenocepacia and all 9 species of the Bcc complex tested were able to make cyanide at comparable levels to P. aeruginosa, but only when grown surface attached as colonies or during biofilm growth on glass beads. In contrast to P. aeruginosa and other cyanogenic bacteria, cyanide was not detected during planktonic growth of Bcc strains. Conclusion All species in the Bcc are cyanogenic when grown as surface attached colonies or as biofilms.

Breathing-mode resonance of a complex plasma disk

International Nuclear Information System (INIS)

Sheridan, T.E.; Buckey, C.R.; Cox, D.J.; Merrill, R.J.; Theisen, W.L.

2004-01-01

We have experimentally characterized the breathing mode oscillation of a strongly-coupled, dusty plasma disk. Steady-state oscillations are excited by sinusoidally modulating the plasma density, creating a single-frequency, in-plane driving force. Resonance curves agree well with damped harmonic oscillator theory. A response at the second harmonic is observed and found to increase with the square of the driving force, indicating a quadratic nonlinearity

Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

Science.gov (United States)

Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

2011-12-01

Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

On the influence of the environment on modeling the fatigue crack growth process

International Nuclear Information System (INIS)

Mc Evily, A.J.

1987-01-01

The effect of the environment at room and elevated temperature were considered with respect to the influence exerted on the basic mechanical aspects of the fatigue crack growth process. An experimental assessment of this influence was obtained by conducting fatigue crack growth tests both in air and vacuum and the results of such experiments are given. Topics considered include crack closure, short crack growth in notched and unnotched specimens, Mode II crack growth, and the effects of oxidation at elevated temperatures. It is shown that the basic mechanisms of fatigue crack growth can be greatly altered by the presence of oxide films at the fatigue crack tip. Modeling the mechanical aspects of the crack growth process is by itself a challenging task. In addition, the environmental considerations adds to the complexity of the modeling process. (Author)

Ballooning mode stabilization by moderate sheared rotation

International Nuclear Information System (INIS)

Hameiri, E.

1996-01-01

Sheared toroidal plasma rotation has been known for some time to have a stabilizing effect on the ballooning modes. A recent calculation showed that a large flow shear, with dΩ/dq of the order of the Alfven toroidal frequency, can stabilize the ballooning modes. This latest result is, in fact, not so optimistic. For observed flows with Mach number of order unity one gets dΩ/dq smaller by a factor O(√β) from the required level (if the flow shear length is of the same order as the magnetic shear length). Moreover, the calculation does not take into account a possibly large transient growth of the mode amplitude due to its Floquet structures We show here that, in fact, there is a general tendency of the ballooning mode to stabilize as soon as the flow shear dΩ/dq exceeds the (O√β smaller) open-quotes slowclose quotes magnetosonic wave frequency. Our analysis is perturbative, where the small parameter is related to the small coupling between the slow and Alfven waves-as is the case in a high aspect-ratio tokamak. (In the perturbation it is important to take the Hamiltonian nature of the governing equations into account.) Moreover, our results apply to the relevant transient growth of the mode amplitude

Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

DEFF Research Database (Denmark)

Muliar, Olena; Usuga Castaneda, Mario A.; Rottwitt, Karsten

2015-01-01

), commonly used in a MDM scenario. This experimental technique requires the use of a Mach-Zehnder interferometer, where the reference's path length is controlled by an optical delay line. The interference between the output beams of reference and fiber under test (FUT) is recorded on a CCD camera......The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength...... or optical modes. Mode division multiplexing (MDM) appears in this context as a promising and viable solution for such capacity increase, since it utilizes multiple spatial modes of an optical fiber as individual communication channels for data transmission. In order to evaluate its performance, a MDM system...

Effect of H-2 complex on the growth of embryo-derived teratomas in mice

International Nuclear Information System (INIS)

Taya, C.; Moriwaki, K.

1986-01-01

Seven-day-old embryos of several H-2 congenic strains were transplanted under the kidney capsules of syngeneic adult recipients to determine the genetic factors(s) governing the in vivo growth of embryo-derived teratomas. A.TH(H-2t2) and A.TL(H-2t1) strains showed significantly greater tumor weights than A.BY(H-2b) and A.SW(H-2s) strains. The A(H-2a) strain was intermediate in tumor size. A comparison of the genic constitution of the H-2 complex in each congenic strain suggested that the H-2D locus and/or its distal regions affected the growth of embryo-derived teratomas. The teratoma induced in the B10.A(H-2a) strain was smaller than that in the A(H-2a) strain, indicating that the genetic background of the A strain is favorable for teratoma growth. Histological observations demonstrated that the existence of embryonal carcinoma cells was necessary for the growth of teratomas. A radiation-sensitive immunological factor in the recipient probably plays a role in stimulating teratoma growth

Complex Network Theory Applied to the Growth of Kuala Lumpur's Public Urban Rail Transit Network.

Science.gov (United States)

Ding, Rui; Ujang, Norsidah; Hamid, Hussain Bin; Wu, Jianjun

2015-01-01

Recently, the number of studies involving complex network applications in transportation has increased steadily as scholars from various fields analyze traffic networks. Nonetheless, research on rail network growth is relatively rare. This research examines the evolution of the Public Urban Rail Transit Networks of Kuala Lumpur (PURTNoKL) based on complex network theory and covers both the topological structure of the rail system and future trends in network growth. In addition, network performance when facing different attack strategies is also assessed. Three topological network characteristics are considered: connections, clustering and centrality. In PURTNoKL, we found that the total number of nodes and edges exhibit a linear relationship and that the average degree stays within the interval [2.0488, 2.6774] with heavy-tailed distributions. The evolutionary process shows that the cumulative probability distribution (CPD) of degree and the average shortest path length show good fit with exponential distribution and normal distribution, respectively. Moreover, PURTNoKL exhibits clear cluster characteristics; most of the nodes have a 2-core value, and the CPDs of the centrality's closeness and betweenness follow a normal distribution function and an exponential distribution, respectively. Finally, we discuss four different types of network growth styles and the line extension process, which reveal that the rail network's growth is likely based on the nodes with the biggest lengths of the shortest path and that network protection should emphasize those nodes with the largest degrees and the highest betweenness values. This research may enhance the networkability of the rail system and better shape the future growth of public rail networks.

Quasi-linear evolution of tearing modes

International Nuclear Information System (INIS)

Pellat, R.; Frey, M.; Tagger, M.

1983-07-01

The growth of a Tearing instability in Rutherford's nonlinear regime is investigated. Using a singular perturbation technique, lowest order Rutherford's result is recovered. To the following order it is shown that the mode generates a quasi-linear deformation of the equilibrium flux profile, whose resistive diffusion slows down the growth and shows the possibility of a saturation of the instability

Effects of dietary fructooligosaccharide levels and feeding modes on growth, immune responses, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala).

Science.gov (United States)

Zhang, Chun-Nuan; Li, Xiang-Fei; Jiang, Guang-Zhen; Zhang, Ding-Dong; Tian, Hong-Yan; Li, Jun-Yi; Liu, Wen-Bin

2014-12-01

This study aimed to determine the effects of fructooligosaccharide (FOS) levels and its feeding modes on growth, immune response, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala). Fish (12.5 ± 0.5 g) were subjected to three FOS levels (0, 0.4% and 0.8%) and two feeding modes (supplementing FOS continuously and supplementing FOS two days interval 5 days) according to a 3 × 2 factorial design. At the end of 8-week feeding trial, fish were challenged by Aeromonas hydrophila with concentration of 1 × 10(5) CFU mL(-1) and mortality was recorded for the next 96 h. Fish fed 0.4% FOS continuously (D2) and fish fed the basal diet for 5 days followed by 0.8% FOS for 2 days (D5) showed admirable growth performance. The highest plasma lysozyme, acid phosphatase and myeloperoxidase activities as well as complement component 3, total protein and immunoglobulin M (IgM) levels were all observed in fish fed D5. They were significantly higher (P 0.05) with that of fish fed D2. A similar trend was also observed in antioxidant capability as well as the expression of Leap-I and Leap-Ⅱ. Mortality showed an opposite trend with the immune response with the lowest rate observed in fish fed D5. The results indicated that diet supplementing FOS in appropriate levels and feeding modes could improve the growth, immune response and antioxidant capability of fish, as might consequently lead to enhanced disease resistance. It can be speculated that the basal diet for 5 days followed by 0.8% FOS for 2 days was most suitable for blunt snout bream. Copyright © 2014 Elsevier Ltd. All rights reserved.

New phenomena in epitaxial growth: solid films on quasicrystalline substrates

International Nuclear Information System (INIS)

Fournee, V; Thiel, P A

2005-01-01

An overview is given of the research conducted in the field of solid film growth on quasiperiodic surfaces. An atomistic description of quasicrystalline surfaces is presented and discussed in relation to bulk structural models. The various systems for which thin film growth has been attempted so far are reviewed. Emphasis is placed on the nucleation mechanisms of the solid films, on their growth modes in relation to the nature of the deposited metals, on the possibility of intermixing or alloying at the interface and on the epitaxial relationships at the crystal-quasicrystal interfaces. We also describe situations where the deposited elements adopt a quasiperiodic structure, which opens up the possibility of extending our understanding of the relation between quasiperiodicity and the physical properties of such structurally and chemically complex solids. (topical review)

Theory of tokamak resistive fishbone modes

International Nuclear Information System (INIS)

Shi Bingren; Sui Guofang

1995-12-01

A special kind of internal kink mode, the fishbone, can be excited by the energetic particles in tokamak plasmas. Theoretical analyses of fishbone modes based on the ideal MHD framework have predicted that two branches of modes exists. One is the Chen-White branch with ω∼ω-bar dm , corresponding to a higher threshold in β h ; the other is the Coppis branch with ω∼ω *i , and a much lower threshold in β h . The latter mode would put a rather unfavourable restriction on heating efficiency and on plasma confinement. However. It is found that the resistivity effect is essential for this mode. In this paper, a new resistive fishbone mode analysis is carried out. In the (γ mhd ,β H ) space, the stability diagram shows complicate structure, the Coppis branch is replaced by a weakly unstable mode and there is no longer closed stable region. The growth rate of this mode varies with β h , its peak value is still very low compared to other internal modes. The implications of these results to future tokamak experiments are discussed. (8 figs.)

Do economic globalization and industry growth destabilize careers? An analysis of career complexity and career patterns over time

NARCIS (Netherlands)

Biemann, T.; Fasang, A.E.; Grunow, D.

2011-01-01

We analyze the impact of economic globalization and industry growth on the complexity of early work careers in Germany. We conceptualize complexity as the absolute number of employer changes, the regularity in the order of job changes, and the variability of the durations spent in different

Computational investigation of single mode vs multimode Rayleigh endash Taylor seeding in Z-pinch implosions

International Nuclear Information System (INIS)

Douglas, M.R.; Deeney, C.; Roderick, N.F.

1998-01-01

A series of two-dimensional magnetohydrodynamic calculations have been carried out to investigate single and multimode growth and mode coupling for magnetically-driven Rayleigh endash Taylor instabilities in Z pinches. Wavelengths ranging from 5.0 mm down to 1.25 mm were considered. Such wavelengths are comparable to those observed at stagnation using a random density open-quotes seedingclose quotes method. The calculations show that wavelengths resolved by less than 10 cells exhibit an artificial decrease in initial Fourier spectrum amplitudes and a reduction in the corresponding amplitude growth. Single mode evolution exhibits linear exponential growth and the development of higher harmonics as the mode transitions into the nonlinear phase. The mode growth continues to exponentiate but at a slower rate than determined by linear hydrodynamic theory. In the two and three mode case, there is clear evidence of mode coupling and inverse cascade. In addition, distinct modal patterns are observed late in the implosion, resulting from finite shell thickness and magnetic field effects. copyright 1998 American Institute of Physics. thinsp

Instability threshold of neoclassical tearing mode, double tearing mode and off-axis sawteeth crash in tokamaks

International Nuclear Information System (INIS)

Li, D.

2001-01-01

The neoclassical and double tearing modes have been analyzed with related new phenomena in the reversed magnetic shear tokamak plasmas. The instability threshold, and the linear and nonlinear evolution are derived for the neoclassical tearing modes. It is found that the perturbed bootstrap current in the resistive layer has a stabilizing effect while the equilibrium bootstrap current in the outer region can destabilize the modes. The dispersion relation is derived for the double tearing mode. It is found that the onset of ''annular crash'' is due to the fast reconnection of the hot and cold islands, triggered by the interaction of both branches. The onset of ''core crash'' is mainly due to the coalescence between the hot islands, triggered by the explosive growth of the inner branch. (author)

Instability threshold of neoclassical tearing mode, double tearing mode and off-axis sawteeth crash in tokamaks

International Nuclear Information System (INIS)

Li Ding

1999-01-01

The neoclassical and double tearing modes have been analyzed with related new phenomena in the reversed magnetic shear tokamak plasmas. The instability threshold, and the linear and nonlinear evolution are derived for the neoclassical tearing modes. It is found that the perturbed bootstrap current in the resistive layer has a stabilizing effect while the equilibrium bootstrap current in the outer region can destabilize the modes. The dispersion relation is derived for the double tearing mode. It is found that the onset of 'annular crash' is due to the fast reconnection of the hot and cold islands, triggered by the interaction of both branches. The onset of 'core crash' is mainly due to the coalescence between the hot islands, triggered by the explosive growth of the inner branch. (author)

The Influence of Prior Modes of Growth, Temperature, Medium, and Substrate Surface on Biofilm Formation by Antibiotic-Resistant Campylobacter jejuni.

Science.gov (United States)

Teh, Amy Huei Teen; Lee, Sui Mae; Dykes, Gary A

2016-12-01

Campylobacter jejuni is one of the most common causes of bacterial gastrointestinal food-borne infection worldwide. It has been suggested that biofilm formation may play a role in survival of these bacteria in the environment. In this study, the influence of prior modes of growth (planktonic or sessile), temperatures (37 and 42 °C), and nutrient conditions (nutrient broth and Mueller-Hinton broth) on biofilm formation by eight C. jejuni strains with different antibiotic resistance profiles was examined. The ability of these strains to form biofilm on different abiotic surfaces (stainless steel, glass, and polystyrene) as well as factors potentially associated with biofilm formation (bacterial surface hydrophobicity, auto-aggregation, and initial attachment) was also determined. The results showed that cells grown as sessile culture generally have a greater ability to form biofilm (P Biofilm was also greater (P biofilm formation in a strain-dependent manner. The strains were able to attach and form biofilms on different abiotic surfaces, but none of them demonstrated strong, complex, or structured biofilm formation. There were no clear trends between the bacterial surface hydrophobicity, auto-aggregation, attachment, and biofilm formation by the strains. This finding suggests that environmental factors did affect biofilm formation by C. jejuni, and they are more likely to persist in the environment in the form of mixed-species rather than monospecies biofilms.

Cognitive Complexity and Verbal Response Mode Use in Discussion.

Science.gov (United States)

Kline, Susan L.; And Others

1990-01-01

Uses William B. Stiles' discourse analysis system to determine whether there are general differences in the way individuals varying in construct system development use their utterances to establish understanding with each other. Finds that construct system development was positively correlated with edification and question response mode use, and…

Industrial case study: evaluation of a mixed-mode resin for selective capture of a human growth factor recombinantly expressed in E. coli.

Science.gov (United States)

Kaleas, Kimberly A; Schmelzer, Charles H; Pizarro, Shelly A

2010-01-08

Mixed-mode chromatography resins are gaining popularity as effective purification tools for challenging feedstocks. This study presents the development of an industrial application to selectively capture recombinant human vascular endothelial growth factor (rhVEGF) on Capto MMC from an alkaline feedstock. Capto MMC resin contains a ligand that has the potential to participate in ionic, hydrophobic, and hydrogen boding interactions with proteins and is coupled to a highly cross-linked agarose bead matrix. VEGF is a key growth factor involved in angiogenesis and has therapeutic applications for wound healing. In this process, it is expressed in Escherichia coli as inclusion bodies. Solids are harvested from the cell lysate, and the rhVEGF is solubilized and refolded at pH 9.8 in the presence of urea and redox reagents. The unique mixed-mode characteristics of Capto MMC enabled capture of this basic protein with minimal load conditioning and delivered a concentrated pool for downstream processing with >95% yields while reducing host cell protein content to study explores the impact of loading conditions and residence time on the dynamic binding capacity as well as the development of elution conditions for optimal purification performance. After evaluating various elution buffers, l-arginine HCl was shown to be an effective eluting agent for rhVEGF desorption from the Capto MMC mixed-mode resin since it successfully disrupted the multiple interactions between the resin and rhVEGF. The lab scale effort produced a robust chromatography step that was successfully implemented at commercial manufacturing scale. Copyright 2009 Elsevier B.V. All rights reserved.

Complex Network Theory Applied to the Growth of Kuala Lumpur's Public Urban Rail Transit Network.

Directory of Open Access Journals (Sweden)

Rui Ding

Full Text Available Recently, the number of studies involving complex network applications in transportation has increased steadily as scholars from various fields analyze traffic networks. Nonetheless, research on rail network growth is relatively rare. This research examines the evolution of the Public Urban Rail Transit Networks of Kuala Lumpur (PURTNoKL based on complex network theory and covers both the topological structure of the rail system and future trends in network growth. In addition, network performance when facing different attack strategies is also assessed. Three topological network characteristics are considered: connections, clustering and centrality. In PURTNoKL, we found that the total number of nodes and edges exhibit a linear relationship and that the average degree stays within the interval [2.0488, 2.6774] with heavy-tailed distributions. The evolutionary process shows that the cumulative probability distribution (CPD of degree and the average shortest path length show good fit with exponential distribution and normal distribution, respectively. Moreover, PURTNoKL exhibits clear cluster characteristics; most of the nodes have a 2-core value, and the CPDs of the centrality's closeness and betweenness follow a normal distribution function and an exponential distribution, respectively. Finally, we discuss four different types of network growth styles and the line extension process, which reveal that the rail network's growth is likely based on the nodes with the biggest lengths of the shortest path and that network protection should emphasize those nodes with the largest degrees and the highest betweenness values. This research may enhance the networkability of the rail system and better shape the future growth of public rail networks.

Two-fluid effects on pressure-driven modes in a heliotron device

International Nuclear Information System (INIS)

Miura, H.; Ito, A.; Sato, M.; Goto, R.; Hatori, T.

2014-10-01

Two-fluid effects on the ballooning or pressure-driven unstable modes are studied numerically to understand physics in linear and nonlinear evolution of them in a heliotron device. Full 3D simulations for β 0 = 5% unstable magnetic configuration of the large helical device show that the introduction of the two-fluid term brings about broader radial profile and higher growth rate in the linear stage of the evolution, weakened parallel heat conduction, and lead to a saturation profile worse than that in the single-fluid MHD simulation. The numerical results show that suppression of high wave-number modes enhance the growth of low wave-number modes. The two-fluid effects and a plausible mild saturation of ballooning modes is discussed. (author)

Comparison study of catalyst nanoparticle formation and carbon nanotube growth: Support effect

International Nuclear Information System (INIS)

Wang Yunyu; Luo Zhiquan; Li Bin; Ho, Paul S.; Yao Zhen; Shi Li; Bryan, Eugene N.; Nemanich, Robert J.

2007-01-01

A comparison study has been conducted on the formation of catalyst nanoparticles on a high surface tension metal and low surface tension oxide for carbon nanotube (CNT) growth via catalytic chemical vapor deposition (CCVD). Silicon dioxide (SiO 2 ) and tantalum have been deposited as supporting layers before deposition of a thin layer of iron catalyst. Iron nanoparticles were formed after thermal annealing. It was found that densities, size distributions, and morphologies of iron nanoparticles were distinctly different on the two supporting layers. In particular, iron nanoparticles revealed a Volmer-Weber growth mode on SiO 2 and a Stranski-Krastanov mode on tantalum. CCVD growth of CNTs was conducted on iron/tantalum and iron/SiO 2 . CNT growth on SiO 2 exhibited a tip growth mode with a slow growth rate of less than 100 nm/min. In contrast, the growth on tantalum followed a base growth mode with a fast growth rate exceeding 1 μm/min. For comparison, plasma enhanced CVD was also employed for CNT growth on SiO 2 and showed a base growth mode with a growth rate greater than 2 μm/min. The enhanced CNT growth rate on tantalum was attributed to the morphologies of iron nanoparticles in combination with the presence of an iron wetting layer. The CNT growth mode was affected by the adhesion between the catalyst and support as well as CVD process

The effect of medium structure complexity on the growth of Saccharomyces cerevisiae in gelatin-dextran systems.

Science.gov (United States)

Boons, Kathleen; Noriega, Estefanía; Verherstraeten, Niels; David, Charlotte C; Hofkens, Johan; Van Impe, Jan F

2015-04-16

As most food systems are (semi-)solid, the effect of food structure on bacterial growth has been widely acknowledged. However, studies on the growth dynamics of yeasts have neglected the effect of food structure. In this paper, the growth dynamics of the spoilage yeast Saccharomyces cerevisiae was investigated at 23.5 °C in broth, singular, homogeneous biopolymer systems and binary biopolymer systems with a heterogeneous microstructure. The biopolymers gelatin and dextran were used to introduce the different levels of structure. The metabolizing ability of gelatin and dextran by S. cerevisiae was examined. To study microbial behavior in the binary systems at the micro level, mixtures were imaged with confocal laser scanning microscopy (CLSM). Growth dynamics and microscopic images of S. cerevisiae were compared with those obtained for Escherichia coli in the same model system (Boons et al., 2014). Different phase-separated, heterogeneous microstructures were obtained by changing the amount of added gelatin and dextran. Regardless of the microstructure, S. cerevisiae was preferentially located in the dextran phase. Metabolizing ability-tests indicated that gelatin could be consumed by S. cerevisiae but in the presence of glucose, no change in gelatin concentration was observed. No indication of dextran metabolizing ability was observed. When supplementing broth with gelatin or dextran alone, an enhanced growth rate and maximum cell density were observed. This enhancement was further increased by adding a second biopolymer, introducing a heterogeneous microstructure and hence increasing the medium structure complexity. The results obtained indicate that food structure complexity plays a significant role in the growth dynamics of S. cerevisiae, an important food spoiler. Copyright © 2014. Published by Elsevier B.V.

Entry Mode Choice in Emerging Markets

OpenAIRE

Gundersen, Anne Kathrine Navestad

2012-01-01

As the mature markets of developed economies have become increasingly saturated, firms are turning their attention towards emerging markets for further enterprise growth. However, these countries often present significant challenges for foreign entrants, forcing firms to adapt their strategies to the new context. While MNEs? entry mode choice is an extensively studied field, there is a deficit in the entry mode research on SMEs, and even more so when it comes to entry into emerging markets in...

Controlling Complex Systems and Developing Dynamic Technology

Science.gov (United States)

Avizienis, Audrius Victor

In complex systems, control and understanding become intertwined. Following Ilya Prigogine, we define complex systems as having control parameters which mediate transitions between distinct modes of dynamical behavior. From this perspective, determining the nature of control parameters and demonstrating the associated dynamical phase transitions are practically equivalent and fundamental to engaging with complexity. In the first part of this work, a control parameter is determined for a non-equilibrium electrochemical system by studying a transition in the morphology of structures produced by an electroless deposition reaction. Specifically, changing the size of copper posts used as the substrate for growing metallic silver structures by the reduction of Ag+ from solution under diffusion-limited reaction conditions causes a dynamical phase transition in the crystal growth process. For Cu posts with edge lengths on the order of one micron, local forces promoting anisotropic growth predominate, and the reaction produces interconnected networks of Ag nanowires. As the post size is increased above 10 microns, the local interfacial growth reaction dynamics couple with the macroscopic diffusion field, leading to spatially propagating instabilities in the electrochemical potential which induce periodic branching during crystal growth, producing dendritic deposits. This result is interesting both as an example of control and understanding in a complex system, and as a useful combination of top-down lithography with bottom-up electrochemical self-assembly. The second part of this work focuses on the technological development of devices fabricated using this non-equilibrium electrochemical process, towards a goal of integrating a complex network as a dynamic functional component in a neuromorphic computing device. Self-assembled networks of silver nanowires were reacted with sulfur to produce interfacial "atomic switches": silver-silver sulfide junctions, which exhibit

Magnetorotational Instability: Nonmodal Growth and the Relationship of Global Modes to the Shearing Box

Energy Technology Data Exchange (ETDEWEB)

J Squire, A Bhattacharjee [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

2014-07-01

We study the magnetorotational instability (MRI) (Balbus & Hawley 1998) using non-modal stability techniques.Despite the spectral instability of many forms of the MRI, this proves to be a natural method of analysis that is well-suited to deal with the non-self-adjoint nature of the linear MRI equations. We find that the fastest growing linear MRI structures on both local and global domains can look very diff erent to the eigenmodes, invariably resembling waves shearing with the background flow (shear waves). In addition, such structures can grow many times faster than the least stable eigenmode over long time periods, and be localized in a completely di fferent region of space. These ideas lead – for both axisymmetric and non-axisymmetric modes – to a natural connection between the global MRI and the local shearing box approximation. By illustrating that the fastest growing global structure is well described by the ordinary diff erential equations (ODEs) governing a single shear wave, we find that the shearing box is a very sensible approximation for the linear MRI, contrary to many previous claims. Since the shear wave ODEs are most naturally understood using non-modal analysis techniques, we conclude by analyzing local MRI growth over finite time-scales using these methods. The strong growth over a wide range of wave-numbers suggests that non-modal linear physics could be of fundamental importance in MRI turbulence (Squire & Bhattacharjee 2014).

Observations on resistive wall modes

International Nuclear Information System (INIS)

Gerwin, R.A.; Finn, J.M.

1996-01-01

Several results on resistive wall modes and their application to tokamaks are presented. First, it is observed that in the presence of collisional parallel dynamics there is an exact cancellation to lowest order of the dissipative and sound wave effects for an ideal Ohm's law. This is easily traced to the fact that the parallel dynamics occurs along the perturbed magnetic field lines for such electromagnetic modes. Such a cancellation does not occur in the resistive layer of a tearing-like mode. The relevance to models for resistive wall modes using an electrostatic Hammett-Perkins type operator to model Landau damping will be discussed. Second, we observe that with an ideal Ohm's law, resistive wall modes can be destabilized by rotation in that part of parameter space in which the ideal MHD modes are stable with the wall at infinity. This effect can easily be explained by interpreting the resistive wall instability in terms of mode coupling between the backward stable MHD mode and a stable mode locked into the wall. Such an effect can occur for very small rotation for tearing-resistive wall modes in which inertia dominates viscosity in the layer, but the mode is stabilized by further rotation. For modes for which viscosity dominates in the layer, rotation is purely stabilizing. For both tearing models, a somewhat higher rotation frequency gives stability essentially whenever the tearing mode is stable with a perfectly conducting wall. These tearing/resistive wall results axe also simply explained in terms of mode coupling. It has been shown that resonant external ideal modes can be stabilized in the presence of resistive wall and resistive plasma with rotation of order the nominal tearing mode growth rate. We show that these modes behave as resistive wall tearing modes in the sense above. This strengthens the suggestion that rotational stabilization of the external kink with a resistive wall is due to the presence of resistive layers, even for ideal modes

Tearing modes in toroidal geometry

International Nuclear Information System (INIS)

Connor, J.W.; Cowley, S.C.; Hastie, R.J.; Hender, T.C.; Hood, A.; Martin, T.J.

1988-01-01

The separation of the cylindrical tearing mode stability problem into a resistive resonant layer calculation and an external marginal ideal magnetohydrodynamic (MHD) calculation (Δ' calculation) is generalized to axisymmetric toroidal geometry. The general structure of this separation is analyzed and the marginal ideal MHD information (the toroidal generalization of Δ') required to discuss stability is isolated. This can then, in principle, be combined with relevant resonant layer calculations to determine tearing mode growth rates in realistic situations. Two examples are given: the first is an analytic treatment of toroidally coupled (m = 1, n = 1) and (m = 2, n = 1) tearing modes in a large aspect ratio torus; the second, a numerical treatment of the toroidal coupling of three tearing modes through finite pressure effects in a large aspect ratio torus. In addition, the use of a coupling integral approach for determining the stability of coupled tearing modes is discussed. Finally, the possibility of using initial value resistive MHD codes in realistic toroidal geometry to determine the necessary information from the ideal MHD marginal solution is discussed

Analysis of current diffusive ballooning mode

International Nuclear Information System (INIS)

Yagi, M.; Azumi, M.; Itoh, K.; Itoh, S.; Fukuyama, A.

1993-04-01

The current diffusive ballooning mode is analysed in the tokamak plasma. This mode is destabilized by the current diffusivity (i.e., the electron viscosity) and stabilized by the thermal conductivity and ion viscosity. By use of the ballooning transformation, the eigenmode equation is solved. Analytic solution is obtained by the strong ballooning limit. Numerical calculation is also performed to confirm the analytic theory. The growth rate of the mode and the mode structure are analysed. The stability boundary is derived in terms of the current diffusivity, thermal conductivity, ion viscosity and the pressure gradient for the given shear parameter. This result is applied to express the thermal conductivity in terms of the pressure gradient, magnetic configurational parameters (such as the safety factor, shear and aspect ratio) and the Prandtl numbers. (author)

Facile synthesis of graphene on single mode fiber via chemical vapor deposition

International Nuclear Information System (INIS)

Zhang, C.; Man, B.Y.; Jiang, S.Z.; Yang, C.; Liu, M.; Chen, C.S.; Xu, S.C.; Feng, D.J.; Bi, D.; Liu, F.Y.; Qiu, H.W.

2014-01-01

Direct deposition of graphene film on the standard single mode fiber is offered using a Cu-vapor-assisted chemical vapor deposition system. The gas flow of H 2 and Ar before the growth process plays a crucial role for the direct deposition of the graphene film and the layers of the graphene can be controlled by the growth time. With a large gas flow, Cu atoms are carried off with the gas flow and hard to deposit on the surface of the single mode fiber before the growth process. Consequently, uniform graphene film is obtained in this case. On the contrary, with a lower one, Cu atoms is facile to deposit on the surface of the single mode fiber and form nanodots acting as active catalytic sites for the growth of carbon nanotubes. This method presents us a promising transfer-free technique for fabrication of the photonic applications.

Causality analysis of leading singular value decomposition modes identifies rotor as the dominant driving normal mode in fibrillation

Science.gov (United States)

Biton, Yaacov; Rabinovitch, Avinoam; Braunstein, Doron; Aviram, Ira; Campbell, Katherine; Mironov, Sergey; Herron, Todd; Jalife, José; Berenfeld, Omer

2018-01-01

Cardiac fibrillation is a major clinical and societal burden. Rotors may drive fibrillation in many cases, but their role and patterns are often masked by complex propagation. We used Singular Value Decomposition (SVD), which ranks patterns of activation hierarchically, together with Wiener-Granger causality analysis (WGCA), which analyses direction of information among observations, to investigate the role of rotors in cardiac fibrillation. We hypothesized that combining SVD analysis with WGCA should reveal whether rotor activity is the dominant driving force of fibrillation even in cases of high complexity. Optical mapping experiments were conducted in neonatal rat cardiomyocyte monolayers (diameter, 35 mm), which were genetically modified to overexpress the delayed rectifier K+ channel IKr only in one half of the monolayer. Such monolayers have been shown previously to sustain fast rotors confined to the IKr overexpressing half and driving fibrillatory-like activity in the other half. SVD analysis of the optical mapping movies revealed a hierarchical pattern in which the primary modes corresponded to rotor activity in the IKr overexpressing region and the secondary modes corresponded to fibrillatory activity elsewhere. We then applied WGCA to evaluate the directionality of influence between modes in the entire monolayer using clear and noisy movies of activity. We demonstrated that the rotor modes influence the secondary fibrillatory modes, but influence was detected also in the opposite direction. To more specifically delineate the role of the rotor in fibrillation, we decomposed separately the respective SVD modes of the rotor and fibrillatory domains. In this case, WGCA yielded more information from the rotor to the fibrillatory domains than in the opposite direction. In conclusion, SVD analysis reveals that rotors can be the dominant modes of an experimental model of fibrillation. Wiener-Granger causality on modes of the rotor domains confirms their

Instability modes on a solid-body-rotation flow in a finite-length pipe

Science.gov (United States)

Feng, Chunjuan; Liu, Feng; Rusak, Zvi; Wang, Shixiao

2017-09-01

Numerical solutions of the incompressible Navier-Stokes equations are obtained to study the time evolution of both axisymmetric and three-dimensional perturbations to a base solid-body-rotation flow in a finite-length pipe with non-periodic boundary conditions imposed at the pipe inlet and outlet. It is found that for a given Reynolds number there exists a critical swirl number beyond which the initial perturbations grow, in contrast to the solid-body rotation flow in an infinitely-long pipe or a finite-length pipe with periodic inlet and exit boundary conditions for which the classical Kelvin analysis and Rayleigh stability criterion affirm neutrally stable for all levels of swirl. This paper uncovers for the first time the detailed evolution of the perturbations in both the axisymmetric and three-dimensional situations. The computations reveal a linear growth stage of the perturbations with a constant growth rate after a brief initial period of decay of the imposed initial perturbations. The fastest growing axisymmetric and three-dimensional instability modes and the associated growth rates are identified numerically for the first time. The computations show that the critical swirl number increases and the growth rate of instability decreases at the same swirl number with decreasing Reynolds number. The growth rate of the axisymmetric mode at high Reynolds number agrees well with previous stability theory for inviscid flow. More importantly, three-dimensional simulations uncover that the most unstable mode is the spiral type m = 1 mode, which appears at a lower critical swirl number than that for the onset of the axisymmetric mode. This spiral mode grows faster than the unstable axisymmetric mode at the same swirl. Moreover, the computations reveal that after the linear growing stage of the perturbation the flow continues to evolve nonlinearly to a saturated axisymmetric vortex breakdown state.

Instability modes on a solid-body-rotation flow in a finite-length pipe

Directory of Open Access Journals (Sweden)

Chunjuan Feng

2017-09-01

Full Text Available Numerical solutions of the incompressible Navier-Stokes equations are obtained to study the time evolution of both axisymmetric and three-dimensional perturbations to a base solid-body-rotation flow in a finite-length pipe with non-periodic boundary conditions imposed at the pipe inlet and outlet. It is found that for a given Reynolds number there exists a critical swirl number beyond which the initial perturbations grow, in contrast to the solid-body rotation flow in an infinitely-long pipe or a finite-length pipe with periodic inlet and exit boundary conditions for which the classical Kelvin analysis and Rayleigh stability criterion affirm neutrally stable for all levels of swirl. This paper uncovers for the first time the detailed evolution of the perturbations in both the axisymmetric and three-dimensional situations. The computations reveal a linear growth stage of the perturbations with a constant growth rate after a brief initial period of decay of the imposed initial perturbations. The fastest growing axisymmetric and three-dimensional instability modes and the associated growth rates are identified numerically for the first time. The computations show that the critical swirl number increases and the growth rate of instability decreases at the same swirl number with decreasing Reynolds number. The growth rate of the axisymmetric mode at high Reynolds number agrees well with previous stability theory for inviscid flow. More importantly, three-dimensional simulations uncover that the most unstable mode is the spiral type m = 1 mode, which appears at a lower critical swirl number than that for the onset of the axisymmetric mode. This spiral mode grows faster than the unstable axisymmetric mode at the same swirl. Moreover, the computations reveal that after the linear growing stage of the perturbation the flow continues to evolve nonlinearly to a saturated axisymmetric vortex breakdown state.

Nanoscale imaging of the growth and division of bacterial cells on planar substrates with the atomic force microscope

Energy Technology Data Exchange (ETDEWEB)

Van Der Hofstadt, M. [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Hüttener, M.; Juárez, A. [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Departament de Microbiologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona (Spain); Gomila, G., E-mail: ggomila@ibecbarcelona.eu [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Departament d' Electronica, Universitat de Barcelona, C/ Marti i Franqués 1, 08028 Barcelona (Spain)

2015-07-15

With the use of the atomic force microscope (AFM), the Nanomicrobiology field has advanced drastically. Due to the complexity of imaging living bacterial processes in their natural growing environments, improvements have come to a standstill. Here we show the in situ nanoscale imaging of the growth and division of single bacterial cells on planar substrates with the atomic force microscope. To achieve this, we minimized the lateral shear forces responsible for the detachment of weakly adsorbed bacteria on planar substrates with the use of the so called dynamic jumping mode with very soft cantilever probes. With this approach, gentle imaging conditions can be maintained for long periods of time, enabling the continuous imaging of the bacterial cell growth and division, even on planar substrates. Present results offer the possibility to observe living processes of untrapped bacteria weakly attached to planar substrates. - Highlights: • Gelatine coatings used to weakly attach bacterial cells onto planar substrates. • Use of the dynamic jumping mode as a non-perturbing bacterial imaging mode. • Nanoscale resolution imaging of unperturbed single living bacterial cells. • Growth and division of single bacteria cells on planar substrates observed.

Peculiarities in film growth of ferroelectric complex oxides in ion-plasma sputtering

International Nuclear Information System (INIS)

Mukhortov, V.M.; Golovko, Yu.I.; Mukhortov, Vl.M.; Dudkevich, V.P.

1981-01-01

Experimental investigation into the process of complex oxide film growth (using BaTiO 3 and (Ba,Sr)TiO 3 as an example) during ion-plasma sputtering has been carried out. It is shown that neutral excited atoms are knocked out of a ceramic target during its ion bombardment. Removing from the target they loss energy at the expence of collisions and at some distance hsub(cr) the oxidation reaction (BaO, TiO, TiO 2 , SrO) becomes possible. So the ''construction'' material comes in either in the form of atoms or in the form of molecules of simple oxides depending on a distance between cathode and substrate. Two mechanisms of synthesis and crystallization distinguished with dependences of growth rate, elementary cell parameters and other structure characteristics on precipitation temperature correspond to two precipitation mechanisms. Part of re-evaporation and reduction processes is discussed [ru

Low-Pass Filtering Approach via Empirical Mode Decomposition Improves Short-Scale Entropy-Based Complexity Estimation of QT Interval Variability in Long QT Syndrome Type 1 Patients

Directory of Open Access Journals (Sweden)

Vlasta Bari

2014-09-01

Full Text Available Entropy-based complexity of cardiovascular variability at short time scales is largely dependent on the noise and/or action of neural circuits operating at high frequencies. This study proposes a technique for canceling fast variations from cardiovascular variability, thus limiting the effect of these overwhelming influences on entropy-based complexity. The low-pass filtering approach is based on the computation of the fastest intrinsic mode function via empirical mode decomposition (EMD and its subtraction from the original variability. Sample entropy was exploited to estimate complexity. The procedure was applied to heart period (HP and QT (interval from Q-wave onset to T-wave end variability derived from 24-hour Holter recordings in 14 non-mutation carriers (NMCs and 34 mutation carriers (MCs subdivided into 11 asymptomatic MCs (AMCs and 23 symptomatic MCs (SMCs. All individuals belonged to the same family developing long QT syndrome type 1 (LQT1 via KCNQ1-A341V mutation. We found that complexity indexes computed over EMD-filtered QT variability differentiated AMCs from NMCs and detected the effect of beta-blocker therapy, while complexity indexes calculated over EMD-filtered HP variability separated AMCs from SMCs. The EMD-based filtering method enhanced features of the cardiovascular control that otherwise would have remained hidden by the dominant presence of noise and/or fast physiological variations, thus improving classification in LQT1.

Spectrum of resistive MHD modes in cylindrical plasmas

International Nuclear Information System (INIS)

Ryu, C.M.; Grimm, R.C.

1983-07-01

A numerical study of the normal modes of a compressible resistive MHD fluid in cylindrical geometry is presented. Resistivity resolves the shear Alfven and slow magnetosonic continua of ideal MHD into discrete spectra and gives rise to heavily damped modes whose frequencies lie on specific lines in the complex plane. Fast magnetosonic waves are less affected but are also damped. Overstable modes arise from the shear Alfven spectrum. The stabilizing effect of favorable average curvature is shown. Eigenfunctions illustrating the nature of typical normal modes are displayed

Mode coupling in spin torque oscillators

International Nuclear Information System (INIS)

Zhang, Steven S.-L.; Zhou, Yan; Li, Dong; Heinonen, Olle

2016-01-01

A number of recent experimental works have shown that the dynamics of a single spin torque oscillator can exhibit complex behavior that stems from interactions between two or more modes of the oscillator, such as observed mode-hopping or mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In the present work, we rigorously derive such a theory starting with the Landau–Lifshitz–Gilbert equation for magnetization dynamics by expanding up to third-order terms in deviation from equilibrium. Our results show how a linear mode coupling, which is necessary for observed mode-hopping to occur, arises through coupling to a magnon bath. The acquired temperature dependence of this coupling implies that the manifold of orbits and fixed points may shift with temperature. - Highlights: • Deriving equations for coupled modes in spin torque oscillators. • Including Hamiltonian formalism and elimination of three–magnon processes. • Thermal bath of magnons central to mode coupling. • Numerical examples of circular and elliptical devices.

Mode coupling in spin torque oscillators

Energy Technology Data Exchange (ETDEWEB)

Zhang, Steven S.-L., E-mail: ZhangShule@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Zhou, Yan, E-mail: yanzhou@hku.hk [Department of Physics, The University of Hong Kong, Hong Kong (China); Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong (China); Li, Dong, E-mail: geodesic.ld@gmail.com [Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Heinonen, Olle, E-mail: heinonen@anl.gov [Material Science Division, Argonne National Laboratory, Lemont, IL 60439 (United States); Northwestern-Argonne Institute of Science and Technology, 2145 Sheridan Road, Evanston, IL 60208 (United States); Computation Institute, The Unversity of Chicago, 5735 S Ellis Avenue, Chicago, IL 60637 (United States)

2016-09-15

A number of recent experimental works have shown that the dynamics of a single spin torque oscillator can exhibit complex behavior that stems from interactions between two or more modes of the oscillator, such as observed mode-hopping or mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In the present work, we rigorously derive such a theory starting with the Landau–Lifshitz–Gilbert equation for magnetization dynamics by expanding up to third-order terms in deviation from equilibrium. Our results show how a linear mode coupling, which is necessary for observed mode-hopping to occur, arises through coupling to a magnon bath. The acquired temperature dependence of this coupling implies that the manifold of orbits and fixed points may shift with temperature. - Highlights: • Deriving equations for coupled modes in spin torque oscillators. • Including Hamiltonian formalism and elimination of three–magnon processes. • Thermal bath of magnons central to mode coupling. • Numerical examples of circular and elliptical devices.

Connection between adiabaticity and the mirror mode

International Nuclear Information System (INIS)

Cohen, R.H.

1976-01-01

The size of magnetic moment jumps of a particle in a long, thin equilibrium magnetic mirror field is shown to be related to the complex zeroes of the mirror mode parameter B + 4πdP/sub perpendicular//dB. A consequence is that adiabaticity places a lower limit on β than does the mirror mode

Laser Covariance Vibrometry for Unsymmetrical Mode Detection

Science.gov (United States)

2006-09-01

2 CMIF Complex Modal Indicator Function . . . . . . . . . . . . . 2 FDAC Frequency Domain Acceptance Criterion . . . . . . . . . . 2 OEM’s Original...complex modal indicator function ( CMIF ) [23] a set of singular value decomposition response functions and the frequency domain acceptance criterion...AFITGEENP03-02. 59. Phillips, Allyn W., Randall J. Allemang, and William A. Fladung. “The Complex Mode Indicator Function ( CMIF ) as a Parameter

Hydromagnetic modes in an inhomogeneous collisionless plasma of finite pressure

International Nuclear Information System (INIS)

Klimushkin, D.Yu.

2006-01-01

One studied three-dimensional structure and rate of growth of hydromagnetic waves. The mode is shown to be the Alfven modified inhomogeneity, finite pressure and plasma anisotropy. The mode structure transverse the magnetic shells may be of two types. Under some specific conditions one may observe image-drift waves in the magnetosphere. The described modes may be responsible for some types of geomagnetic field oscillations [ru

Infrared, diode laser spectroscopy of the Ar--N2O complex: Observation of the intermolecular bending mode in combination with the highest frequency intramolecular stretching mode

International Nuclear Information System (INIS)

Hu, T.A.; Chappell, E.L.; Sharpe, S.W.

1993-01-01

Rotationally resolved vibrational spectra consisting of a-type transitions have been observed for the low-frequency, intermolecular bending mode in combination with the highest frequency, intramolecular stretching mode of Ar--N 2 O. Analysis of the spectral data places the origin of the combination band at 2256.1 cm -1 while the origin of the intramolecular stretching fundamental is at 2223.9 cm -1 . The difference between these two origins is approximately 32.2 cm -1 and agrees well with our calculated frequency of 31.5 cm -1 for the intermolecular bending mode, which was obtained by analysis of the centrifugal distortion constants. In addition, argon--nitrous oxide exhibits an anomalously large inertial defect of 10.96 amu A 2 in the combination state. This indicates a breakdown in the assumption of separation between vibration and rotation. While much of the inertial defect in the ground state can be accounted for by including Coriolis interactions, that occurring in the combination state is only partially accounted for by a similar analysis. Small, but significant changes, are observed in both the radial and angular parameters for Ar--N 2 O when going from the ground to the combination state, indicating large amplitude motion. The combination band is approximately 200 times less intense than the high-frequency, stretching fundamental of Ar--N 2 O. In addition, over 400 new rovibrational transitions are assigned to the previously observed 1 0 1 intramolecular stretching fundamental of the complex, and the subsequent rotational analysis is found to be in close agreement with earlier studies. Data were taken on a newly built, rapid-scan, diode laser spectrometer that incorporates a 12 cmx200 μm pulsed slit-expansion nozzle

Second-mode control in hypersonic boundary layers over assigned complex wall impedance

Science.gov (United States)

Sousa, Victor; Patel, Danish; Chapelier, Jean-Baptiste; Scalo, Carlo

2017-11-01

The durability and aerodynamic performance of hypersonic vehicles greatly relies on the ability to delay transition to turbulence. Passive aerodynamic flow control devices such as porous acoustic absorbers are a very attractive means to damp ultrasonic second-mode waves, which govern transition in hypersonic boundary layers under idealized flow conditions (smooth walls, slender geometries, small angles of attack). The talk will discuss numerical simulations modeling such absorbers via the time-domain impedance boundary condition (TD-IBC) approach by Scalo et al. in a hypersonic boundary layer flow over a 7-degree wedge at freestream Mach numbers M∞ = 7.3 and Reynolds numbers Rem = 1.46 .106 . A three-parameter impedance model tuned to the second-mode waves is tested first with varying resistance, R, and damping ratio, ζ, revealing complete mode attenuation for R workers at DLR-Göttingen.

A human transcription factor in search mode.

Science.gov (United States)

Hauser, Kevin; Essuman, Bernard; He, Yiqing; Coutsias, Evangelos; Garcia-Diaz, Miguel; Simmerling, Carlos

2016-01-08

Transcription factors (TF) can change shape to bind and recognize DNA, shifting the energy landscape from a weak binding, rapid search mode to a higher affinity recognition mode. However, the mechanism(s) driving this conformational change remains unresolved and in most cases high-resolution structures of the non-specific complexes are unavailable. Here, we investigate the conformational switch of the human mitochondrial transcription termination factor MTERF1, which has a modular, superhelical topology complementary to DNA. Our goal was to characterize the details of the non-specific search mode to complement the crystal structure of the specific binding complex, providing a basis for understanding the recognition mechanism. In the specific complex, MTERF1 binds a significantly distorted and unwound DNA structure, exhibiting a protein conformation incompatible with binding to B-form DNA. In contrast, our simulations of apo MTERF1 revealed significant flexibility, sampling structures with superhelical pitch and radius complementary to the major groove of B-DNA. Docking these structures to B-DNA followed by unrestrained MD simulations led to a stable complex in which MTERF1 was observed to undergo spontaneous diffusion on the DNA. Overall, the data support an MTERF1-DNA binding and recognition mechanism driven by intrinsic dynamics of the MTERF1 superhelical topology. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Circular modes for flat beams in the LHC

Directory of Open Access Journals (Sweden)

A. Burov

2013-06-01

Full Text Available Typically x/y optical coupling is considered as unwanted and thus suppressed; particular exclusions are electron and ionization coolers. Could some special coupled modes be effectively applied for the LHC complex? Perhaps, the answer is positive: use of the circular modes in the injectors with their transformation into planar modes in the LHC allows both the space charge and beam-beam luminosity limitations to be significantly reduced, if not practically eliminated.

Characteristics of growth of complex ferroelectric oxide films by plasma-ion sputtering

Science.gov (United States)

Mukhortov, V. M.; Golovko, Yu. I.; Mukhortov, Vl. M.; Dudkevich, V. P.

1981-02-01

An experimental investigation was made of the process of growth of a complex oxide film, such as BaTiO3 or (Ba, Sr)TiO3, by plasma-ion sputtering. It was found that ion bombardment of a ceramic target knocked out neutral excited atoms. These atoms lost energy away from the target by collisions and at a certain critical distance hcr they were capable of oxidation to produce BaO, TiO, TiO2, and SrO. Therefore, depending on the distance between the cathode and the substrate, the “construction” material arrived in the form of atoms or molecules of simple oxides. These two (atomic and molecular) deposition mechanisms corresponded to two mechanisms of synthesis and crystallization differing in respect of the dependences of the growth rate, unit cell parameters, and other structural properties on the deposition temperature. The role of re-evaporation and of oxidation-reduction processes was analyzed.

Nonlinear magnetohydrodynamics of edge localized mode precursors

Energy Technology Data Exchange (ETDEWEB)

Guo, Z. B., E-mail: guozhipku@gmail.com [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing (China); WCI Center for Fusion Theory, NFRI, Gwahangno 113, Yusung-gu, Daejeon 305-333 (Korea, Republic of); Wang, Lu [SEEE, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Wang, X. G. [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing (China)

2015-02-15

A possible origin of edge-localized-mode (ELM) precursors based on nonlinear ideal peeling-ballooning mode is reported. Via nonlinear variational principle, a nonlinear evolution equation of the radial displacement is derived and solved, analytically. Besides an explosive growth in the initial nonlinear phase, it is found that the local displacement evolves into an oscillating state in the developed nonlinear phase. The nonlinear frequency of the ELM precursors scales as ω{sub pre}∼x{sup 1/3}ξ{sup ^}{sub ψ,in}{sup 2/3}n, with x position in radial direction, ξ{sup ^}{sub ψ,in} strength of initial perturbation, and n toroidal mode number.

Linear calculations of edge current driven kink modes with BOUT++ code

Energy Technology Data Exchange (ETDEWEB)

Li, G. Q., E-mail: ligq@ipp.ac.cn; Xia, T. Y. [Institute of Plasma Physics, CAS, Hefei, Anhui 230031 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Snyder, P. B.; Turnbull, A. D. [General Atomics, San Diego, California 92186 (United States); Ma, C. H.; Xi, P. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); FSC, School of Physics, Peking University, Beijing 100871 (China)

2014-10-15

This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density.

Linear calculations of edge current driven kink modes with BOUT++ code

International Nuclear Information System (INIS)

Li, G. Q.; Xia, T. Y.; Xu, X. Q.; Snyder, P. B.; Turnbull, A. D.; Ma, C. H.; Xi, P. W.

2014-01-01

This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density

QUANTITATIVE TESTS OF ELMs AS INTERMEDIATE n PEELING-BALOONING MODES

International Nuclear Information System (INIS)

LAO, LL; SNYDER, PB; LEONARD, AW; OIKAWA, T; OSBORNE, TH; PETRIE, TW; FERRON, JR; GROEBNER, RJ; HORTON, LD; KAMADA, Y; MURAKAMI, M; SAARELMA, S; STJOHN, HE; TURNBULL, AD; WILSON, HR

2003-01-01

A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES. Several testable features of the working model of edge localized modes (ELMs) as intermediate toroidal mode number peeling-ballooning modes are evaluated quantitatively using DIII-D and JT-60U experimental data and the ELITE MHD stability code. These include the hypothesis that ELM sizes are related to the radial widths of the unstable MHD modes, the unstable modes have a strong ballooning character localized in the outboard bad curvature region, and ELM size generally becomes smaller at high edge collisionality. ELMs are triggered when the growth rates of the unstable MHD modes become significantly large. These testable features are consistent with many ELM observations in DIII-D and JT-60U discharges

Effect of Weakly Nonthermal Ion Velocity Distribution on Jeans Instability in a Complex Plasma in Presence of Secondary Electrons

International Nuclear Information System (INIS)

Sarkar, S.; Maity, S.

2013-01-01

In this paper we have investigated the effect of weak nonthermality of ion velocity distribution on Jean’s instability in a complex plasma in presence of secondary electrons and negatively charged dust grains. The primary and secondary electron temperatures are assumed equal. Thus plasma under consideration consists of three components: Boltzman distributed electrons, non-thermal ions and negatively charged inertial dust grains. From the linear dispersion relation we have calculated the real frequency and growth rate of the Jean’s mode. Numerically we have found that secondary electron emission destabilizes Jean’s mode when ion nonthermality is weak. (author)

Verification of GENE and GYRO with L-mode and I-mode plasmas in Alcator C-Mod

Science.gov (United States)

Mikkelsen, D. R.; Howard, N. T.; White, A. E.; Creely, A. J.

2018-04-01

Verification comparisons are carried out for L-mode and I-mode plasma conditions in Alcator C-Mod. We compare linear and nonlinear ion-scale calculations by the gyrokinetic codes GENE and GYRO to each other and to the experimental power balance analysis. The two gyrokinetic codes' linear growth rates and real frequencies are in good agreement throughout all the ion temperature gradient mode branches and most of the trapped electron mode branches of the kyρs spectra at r/a = 0.65, 0.7, and 0.8. The shapes of the toroidal mode spectra of heat fluxes in nonlinear simulations are very similar for kyρs ≤ 0.5, but in most cases GENE has a relatively higher heat flux than GYRO at higher mode numbers. The ratio of ion to electron heat flux is similar in the two codes' simulations, but the heat fluxes themselves do not agree in almost all cases. In the I-mode regime, GENE's heat fluxes are ˜3 times those from GYRO, and they are ˜60%-100% higher than GYRO in the L-mode conditions. The GYRO under-prediction of Qe is much reduced in GENE's L-mode simulations, and it is eliminated in the I-mode simulations. This largely improved agreement with the experimental electron heat flux is offset, however, by the large overshoot of GENE's ion heat fluxes, which are 2-3 times the experimental level, and its electron heat flux overshoot at r/a = 0.80 in the I-mode. Rotation effects can explain part of the difference between the two codes' predictions, but very significant differences remain in simulations without any rotation effects.

Hepatoma-derived growth factor and nucleolin exist in the same ribonucleoprotein complex

Directory of Open Access Journals (Sweden)

Bremer Stephanie

2013-01-01

Full Text Available Abstract Background Hepatoma-derived growth factor (HDGF is a protein which is highly expressed in a variety of tumours. HDGF has mitogenic, angiogenic, neurotrophic and antiapoptotic activity but the molecular mechanisms by which it exerts these activities are largely unknown nor has its biological function in tumours been elucidated. Mass spectrometry was performed to analyse the HDGFStrep-tag interactome. By Pull–down-experiments using different protein and nucleic acid constructs the interaction of HDGF and nucleolin was investigated further. Results A number of HDGFStrep-tag copurifying proteins were identified which interact with RNA or are involved in the cellular DNA repair machinery. The most abundant protein, however, copurifying with HDGF in this approach was nucleolin. Therefore we focus on the characterization of the interaction of HDGF and nucleolin in this study. We show that expression of a cytosolic variant of HDGF causes a redistribution of nucleolin into the cytoplasm. Furthermore, formation of HDGF/nucleolin complexes depends on bcl-2 mRNA. Overexpression of full length bcl-2 mRNA increases the number of HDGF/nucleolin complexes whereas expression of only the bcl-2 coding sequence abolishes interaction completely. Further examination reveals that the coding sequence of bcl-2 mRNA together with either the 5′ or 3′ UTR is sufficient for formation of HDGF/nucleolin complexes. When bcl-2 coding sequence within the full length cDNA is replaced by a sequence coding for secretory alkaline phosphatase complex formation is not enhanced. Conclusion The results provide evidence for the existence of HDGF and nucleolin containing nucleoprotein complexes which formation depends on the presence of specific mRNAs. The nature of these RNAs and other components of the complexes should be investigated in future.

3-D near-field imaging of guided modes in nanophotonic waveguides

Directory of Open Access Journals (Sweden)

Ziegler Jed I.

2017-04-01

Full Text Available Highly evanescent waveguides with a subwavelength core thickness present a promising lab-on-chip solution for generating nanovolume trapping sites using overlapping evanescent fields. In this work, we experimentally studied Si3N4 waveguides whose sub-wavelength cross-sections and high aspect ratios support fundamental and higher order modes at a single excitation wavelength. Due to differing modal effective indices, these co-propagating modes interfere and generate beating patterns with significant evanescent field intensity. Using near-field scanning optical microscopy (NSOM, we map the structure of these beating modes in three dimensions. Our results demonstrate the potential of NSOM to optimize waveguide design for complex field trapping devices. By reducing the in-plane width, the population of competing modes decreases, resulting in a simplified spectrum of beating modes, such that waveguides with a width of 650 nm support three modes with two observed beats. Our results demonstrate the potential of NSOM to optimize waveguide design for complex field trapping devices.

Alternative Binding Modes Identified for Growth and Differentiation Factor-associated Serum Protein (GASP) Family Antagonism of Myostatin*

Science.gov (United States)

Walker, Ryan G.; Angerman, Elizabeth B.; Kattamuri, Chandramohan; Lee, Yun-Sil; Lee, Se-Jin; Thompson, Thomas B.

2015-01-01

Myostatin, a member of the TGF-β family of ligands, is a strong negative regulator of muscle growth. As such, it is a prime therapeutic target for muscle wasting disorders. Similar to other TGF-β family ligands, myostatin is neutralized by binding one of a number of structurally diverse antagonists. Included are the antagonists GASP-1 and GASP-2, which are unique in that they specifically antagonize myostatin. However, little is known from a structural standpoint describing the interactions of GASP antagonists with myostatin. Here, we present the First low resolution solution structure of myostatin-free and myostatin-bound states of GASP-1 and GASP-2. Our studies have revealed GASP-1, which is 100 times more potent than GASP-2, preferentially binds myostatin in an asymmetrical 1:1 complex, whereas GASP-2 binds in a symmetrical 2:1 complex. Additionally, C-terminal truncations of GASP-1 result in less potent myostatin inhibitors that form a 2:1 complex, suggesting that the C-terminal domains of GASP-1 are the primary mediators for asymmetric complex formation. Overall, this study provides a new perspective on TGF-β antagonism, where closely related antagonists can utilize different ligand-binding strategies. PMID:25657005

Trajectories of Identity Formation Modes and Their Personality Context in Adolescence.

Science.gov (United States)

Topolewska-Siedzik, Ewa; Cieciuch, Jan

2018-04-01

Identity formation is a dynamic process during adolescence. Trajectories of identity formation were assessed longitudinally in early and middle adolescents, taking into account the personality underpinnings of this process. Identity formation was conceptualized according to the circumplex of identity formation modes. The model distinguishes basic modes rooted in Marcia's categories of exploration and commitment. Plasticity and stability, the two higher order Big Five meta-traits, were used to assess personality underpinnings. This study includes five measurement waves over 1.5 years and involves 1,839 Polish participants; 914 early adolescents (53.9% girls) and 925 middle adolescents (63.8% girls). The results suggest that (1) the four identity formation modes change dynamically, showing linear and curvilinear growth and that (2) identity formation mode trajectories are more dynamic in middle adolescence than in early adolescence. The results also showed that, in the conditional model, (3) the higher-order personality factors and gender affect the growth factors of identity formation modes. Overall, trajectories of identity formation modes are more linear during early adolescence and more curvilinear during middle adolescence. The initial levels in identity trajectories are influenced by the personality metatraits but only plasticity is related to change among early adolescents.

On fully three-dimensional resistive wall mode and feedback stabilization computations

International Nuclear Information System (INIS)

Strumberger, E.; Merkel, P.; Sempf, M.; Guenter, S.

2008-01-01

Resistive walls, located close to the plasma boundary, reduce the growth rates of external kink modes to resistive time scales. For such slowly growing resistive wall modes, the stabilization by an active feedback system becomes feasible. The fully three-dimensional stability code STARWALL, and the feedback optimization code OPTIM have been developed [P. Merkel and M. Sempf, 21st IAEA Fusion Energy Conference 2006, Chengdu, China (International Atomic Energy Agency, Vienna, 2006, paper TH/P3-8] to compute the growth rates of resistive wall modes in the presence of nonaxisymmetric, multiply connected wall structures and to model the active feedback stabilization of these modes. In order to demonstrate the capabilities of the codes and to study the effect of the toroidal mode coupling caused by multiply connected wall structures, the codes are applied to test equilibria using the resistive wall structures currently under debate for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)] and ASDEX Upgrade [W. Koeppendoerfer et al., Proceedings of the 16th Symposium on Fusion Technology, London, 1990 (Elsevier, Amsterdam, 1991), Vol. 1, p. 208

Quasinormal Modes of a Quantum-Corrected Schwarzschild Black ...

Indian Academy of Sciences (India)

Chunyan Wang

2017-11-27

Nov 27, 2017 ... Abstract. In this work, we investigate the electromagnetic perturbation around a quantum-corrected. Schwarzschild black hole. The complex frequencies of the quasinormal modes are evaluated by the third- order WKB approximation. The numerical results obtained showed that the complex frequencies ...

From current-driven to neoclassically driven tearing modes.

Science.gov (United States)

Reimerdes, H; Sauter, O; Goodman, T; Pochelon, A

2002-03-11

In the TCV tokamak, the m/n = 2/1 island is observed in low-density discharges with central electron-cyclotron current drive. The evolution of its width has two distinct growth phases, one of which can be linked to a "conventional" tearing mode driven unstable by the current profile and the other to a neoclassical tearing mode driven by a perturbation of the bootstrap current. The TCV results provide the first clear observation of such a destabilization mechanism and reconcile the theory of conventional and neoclassical tearing modes, which differ only in the dominant driving term.

Locked modes and magnetic field errors in MST

International Nuclear Information System (INIS)

Almagri, A.F.; Assadi, S.; Prager, S.C.; Sarff, J.S.; Kerst, D.W.

1992-06-01

In the MST reversed field pinch magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance, the disturbance locks to an impulsive field error generated at a sawtooth crash, the error fields grow monotonically after locking (perhaps due to an unstable interaction between the modes and field error), and over the tens of milliseconds of growth confinement degrades and the discharge eventually terminates. Field error control has been partially successful in eliminating locking

New modes of assisted mechanical ventilation.

Science.gov (United States)

Suarez-Sipmann, F

2014-05-01

Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

Control of growth mode of multiwalled carbon nanotubes

International Nuclear Information System (INIS)

Nguyen Hong Quang; Kim, Do-Hyung

2009-01-01

We have conducted an experimental study to investigate the synthesis of multi-walled carbon nanotubes (CNTs) by a dc plasma-enhanced chemical vapour deposition (PECVD) technique. The synthesis of base and tip-type of CNTs was selectively controlled by changing the catalyst size, catalyst film thickness correlated with altering the NH 3 pretreatment plasma current. These types of CNT showed distinctive properties in nanotube structure, growth rate and vertical alignment, which were confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and in situ optical interference measurement. The vertically aligned behaviour of CNT was systematically studied by using a fine-patterned catalyst layer with diverse critical dimensions. Freestanding single CNT was successfully realized by optimum tip-type CNT growth, conventional photolithography and wet-etch process.

Saturation and postsaturation phenomena of Rayleigh-Taylor instability with adjacent modes

International Nuclear Information System (INIS)

Ikegawa, Tadashi; Nishihara, Katsunobu

2003-01-01

A weakly nonlinear theory has been developed for the classical Rayleigh-Taylor instability with a finite bandwidth taken into account self-consistently. The theory includes up to third order nonlinearity, which results in the saturation of linear growth and determines subsequent weakly nonlinear growth. Analytical results are shown to agree fairly well with two-dimensional hydrodynamic simulations. There are generally many local peaks of a perturbation with a finite bandwidth due to the interference of modes. Since a local amplitude is determined from phases among the modes as well as the bandwidth, we have investigated an onset of the linear growth saturation and the subsequent weakly nonlinear growth for different bandwidths and phases. It is shown that the saturation of the linear growth occurs locally, i.e., each of the local maximum amplitudes (LMAs) grows exponentially until it reaches almost the same saturation amplitude. In the random phase case, the root mean square amplitude thus saturates with almost the same amplitude as the LMA, after most of the LMAs have saturated. The saturation amplitude of the LMA is found to be independent of the bandwidth and depends on the Atwood number. We derive a formula of the saturation amplitude of modes based on the results obtained, and discuss its relation with Haan's formula [Phys. Rev. A 39, 5812 (1989)]. The LMAs grow linearly in time after the saturation and their speeds are approximated by the product of the linear growth rate and the saturation amplitude. We investigate the Atwood number dependence of both the saturation amplitude and the weakly nonlinear growth

General description and understanding of the nonlinear dynamics of mode-locked fiber lasers.

Science.gov (United States)

Wei, Huai; Li, Bin; Shi, Wei; Zhu, Xiushan; Norwood, Robert A; Peyghambarian, Nasser; Jian, Shuisheng

2017-05-02

As a type of nonlinear system with complexity, mode-locked fiber lasers are known for their complex behaviour. It is a challenging task to understand the fundamental physics behind such complex behaviour, and a unified description for the nonlinear behaviour and the systematic and quantitative analysis of the underlying mechanisms of these lasers have not been developed. Here, we present a complexity science-based theoretical framework for understanding the behaviour of mode-locked fiber lasers by going beyond reductionism. This hierarchically structured framework provides a model with variable dimensionality, resulting in a simple view that can be used to systematically describe complex states. Moreover, research into the attractors' basins reveals the origin of stochasticity, hysteresis and multistability in these systems and presents a new method for quantitative analysis of these nonlinear phenomena. These findings pave the way for dynamics analysis and system designs of mode-locked fiber lasers. We expect that this paradigm will also enable potential applications in diverse research fields related to complex nonlinear phenomena.

Dose to the metaphyseal growth complexes in children undergoing /sup 99m/Tc-EHDP bone scans

International Nuclear Information System (INIS)

Thomas, S.R.; Gelfand, M.J.; Kerelakes, J.G.; Ascoli, F.A.; Maxon, H.R.; Saenger, E.L.; Feller, P.A.; Sodd, V.J.; Paras, P.

1978-01-01

The spatial and temporal distribution of radionuclides in children may differ greatly from that accepted for adults. Following injection of a bone-seeking agent (/sup 99m/Tc-EHDP), radioactivity in the metaphyseal growth complexes of the distal femur and proximal tibia was quantitated in a series of children 4 to 16 years of age, using a gamma camera/computer system. The dose to the growth plate was found to range from 0.8 to 4.7 rads when adjusted to an administered activity of 200 μci/kg, compared to approximately 0.6 rad to the adult skeleton for a corresponding study

Basic mode of nonlinear spin-wave resonance in normally magnetized ferrite films

International Nuclear Information System (INIS)

Gulyaev, Yu.V.; Zil'berman, P.E.; Timiryazev, A.G.; Tikhomirova, M.P.

2000-01-01

Modes of nonlinear and spin-wave resonance (SWR) in the normally magnetized ferrite films were studied both theoretically and experimentally. The particular emphasis was placed on the basic mode of SWR. One showed theoretically that with the growth of the precession amplitude the profile of the basic mode changed. The nonlinear shift of the resonance field depends on the parameters of fixing of the surface spins. Films of ferroyttrium garnet (FYG) with strong gradient of the single-axis anisotropy field along the film thickness, as well as, FYG films of the submicron thickness where investigated experimentally. With the intensification of Uhf-power one observed the sublinear shift of the basic mode resonance field following by the superlinear growth of the absorbed power. That kind of behaviour is explained by variation of the profile of the varying magnetization space distribution [ru

Matrix method for two-dimensional waveguide mode solution

Science.gov (United States)

Sun, Baoguang; Cai, Congzhong; Venkatesh, Balajee Seshasayee

2018-05-01

In this paper, we show that the transfer matrix theory of multilayer optics can be used to solve the modes of any two-dimensional (2D) waveguide for their effective indices and field distributions. A 2D waveguide, even composed of numerous layers, is essentially a multilayer stack and the transmission through the stack can be analysed using the transfer matrix theory. The result is a transfer matrix with four complex value elements, namely A, B, C and D. The effective index of a guided mode satisfies two conditions: (1) evanescent waves exist simultaneously in the first (cladding) layer and last (substrate) layer, and (2) the complex element D vanishes. For a given mode, the field distribution in the waveguide is the result of a 'folded' plane wave. In each layer, there is only propagation and absorption; at each boundary, only reflection and refraction occur, which can be calculated according to the Fresnel equations. As examples, we show that this method can be used to solve modes supported by the multilayer step-index dielectric waveguide, slot waveguide, gradient-index waveguide and various plasmonic waveguides. The results indicate the transfer matrix method is effective for 2D waveguide mode solution in general.

Resistive mode in rotating plasma columns including the hall current

International Nuclear Information System (INIS)

Galvao, R.M.O.

1983-01-01

A new resistive mode is shown to exist in rotating plasma columns. The mode is localized in the neighbourhood of the radius where the angular velocity of the bulk plasma is equal to minus half the local angular velocity of the ions. This singular point is caused by the Hall term in the generalized Ohm law. The growth rate of the mode scales with eta sup(1/2), where eta is the plasma resistivity. (Author) [pt

The evolution of transmission mode

Science.gov (United States)

Forbes, Mark R.; Hauffe, Heidi C.; Kallio, Eva R.; Okamura, Beth; Sait, Steven M.

2017-01-01

This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289251

Effects of ion temperature fluctuations on the stability of resistive ballooning modes

International Nuclear Information System (INIS)

Singh, R.; Nordman, H.; Jarmen, A.; Weiland, J.

1996-01-01

The influence of ion temperature fluctuations on the stability of resistive drift- and ballooning-modes is investigated using a two-fluid model. The Eigenmode equations are derived and solved analytically in a low beta model equilibrium. Parameters relevant to L-mode edge plasmas from the Texas Experimental Tokamak are used. The resistive modes are found to be destabilized by ion temperature fluctuations over a broad range of mode numbers. The scaling of the growth rate with magnetic shear and mode number is elucidated. 13 refs, 4 figs

Nonlinear tearing modes in the reversed field pinch

International Nuclear Information System (INIS)

Miller, G.

1989-01-01

Finite-amplitude islands, which are the saturated states of tearing modes in the reversed field pinch, are calculated. These states are bifurcated noncylindrical equilibrium states. With σ(r) (σequivalentj x B/B 2 ) nonuniform across the plasma, as is consistent with experiment, a variety of m = 1 and m = 0 bifurcated equilibria are possible, instead of just the m = 1 helix calculated for uniform σ(r) by Taylor [in Pulsed High Beta Plasmas, edited by D. Evans (Pergamon, Oxford, 1976), p. 59]. Assuming the magnetic field lines in the reversed field pinch are weakly stochastic, the growth time of an unstable tearing mode is on the inertial time scale, as in the Taylor model, in constrast to growth on the resistive time scale predicted from nonlinear tearing mode theory when magnetic surfaces exist. The dependence of the saturated island width on radius of a conducting shell is investigated. Islands in the reversed field pinch often have magnetic wells in the island interior, which may result in improved confinement in the island regions

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

International Nuclear Information System (INIS)

Takahashi, J.; Nakamura, Y.; Yamanaka, Y.

2014-01-01

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

Influence of asymmetric magnetic perturbation on the nonlinear evolution of double tearing modes

Science.gov (United States)

Xiong, G. Z.; Wang, L.; Li, X. Q.; Liu, H. F.; Tang, C. J.; Huang, J.; Zhang, X.; Wang, X. Q.

2017-06-01

The effects of asymmetric magnetic perturbation on the triggering and evolution of double tearing modes (DTMs) are investigated using nonlinear magnetohydrodynamics simulations in a slab geometry. We find that for reversed magnetic shear plasmas the resistive reconnection process induced by the initial perturbation at one rational surface can drive a new island at the other rational surface with the same mode number. The four typical states of the mode for the time evolution are found, and include: (i) a linear growth stage; (ii) a linear/nonlinear stable stage; (iii) an interactively driving stage; and (iv) a symmetric DTM stage. These differ from previous simulation results. Moreover, nonlinear DTM growth is found to strongly depend on the asymmetric magnetic perturbation, particularly in the early nonlinear phase. The initial perturbation strength scale of island width suggests that the left island enters into a Sweet-Parker growth process when the right island is sufficiently large to effectively drive the other. These results predict that although externally applied magnetic perturbations can suppress the neoclassical tearing mode they can also trigger new instabilities such as asymmetric DTMs.

Influence of asymmetric magnetic perturbation on the nonlinear evolution of double tearing modes

International Nuclear Information System (INIS)

Xiong, G Z; Liu, H F; Huang, J; Wang, X Q; Wang, L; Li, X Q; Tang, C J; Zhang, X

2017-01-01

The effects of asymmetric magnetic perturbation on the triggering and evolution of double tearing modes (DTMs) are investigated using nonlinear magnetohydrodynamics simulations in a slab geometry. We find that for reversed magnetic shear plasmas the resistive reconnection process induced by the initial perturbation at one rational surface can drive a new island at the other rational surface with the same mode number. The four typical states of the mode for the time evolution are found, and include: (i) a linear growth stage; (ii) a linear/nonlinear stable stage; (iii) an interactively driving stage; and (iv) a symmetric DTM stage. These differ from previous simulation results. Moreover, nonlinear DTM growth is found to strongly depend on the asymmetric magnetic perturbation, particularly in the early nonlinear phase. The initial perturbation strength scale of island width suggests that the left island enters into a Sweet–Parker growth process when the right island is sufficiently large to effectively drive the other. These results predict that although externally applied magnetic perturbations can suppress the neoclassical tearing mode they can also trigger new instabilities such as asymmetric DTMs. (paper)

SPA-LEED Study of the Morphology and Nucleation of a Novel Growth Mode and the ''devil's staircase'' on Pb/Si(111)

International Nuclear Information System (INIS)

Wang-Chi Vincent Yeh

2003-01-01

This thesis was developed to address the following questions for the Pb/Si(111) system: (1) Is it possible to control the nano-structure growth by changing the initial substrate; (2) is the nucleation theory applicable to the case of the 7-step growth mode; and (3) what phase or phases could be formed between coverage 6/5 ML and 4/3 ML? The first question was answered in chapter 2, different growth results were observed for different initial substrate, suggesting the possibility of controlling nano-structure growth by selecting the initial substrate. The applicability of nucleation theory was determined to be unclear in chapter 3, from the results that the saturation island density does not depend on deposition rate, in contrary to the prediction of nucleation theory. Chapter 4 revealed a novel ''devil's staircase'' in Pb/Si(111) within the coverage range 6/5 ML and 4/3 ML. Low temperature deposition experiments showed high order of self-organization in such a system. Theoretical studies are needed to understand such a low temperature behavior. In general, this thesis provides possibilities of controlling nano-structure growth, which can be possibly an indication for future application. It also raises interesting questions in fundamental researches: a modified theory of nucleation is needed, and a detailed study of low temperature behavior is required. Details of the conclusions in each of the chapters are collected in the following sections

Study of density fluctuation in L-mode and H-mode plasmas on JFT-2M by microwave reflectometer

International Nuclear Information System (INIS)

Shinohara, Kouji

1997-08-01

We propose the model which can explain the runaway phase. The model takes account of the scattered wave which is caused by the density fluctuation near the cut-off layer. We should take a new approach instead of the conventional phase measurement in order to derive the information of the density fluctuation from the data with the runaway phase. The complex spectrum and the rotary spectrum analyses are useful tools to analyze such data. The density fluctuation in L-mode and H-mode plasmas is discussed by using this new approach. We have observed that the reduction of the density fluctuation is localized in the edge region where the sheared electric field is produced. The fluctuations in the range of frequency lower than 100 kHz are mainly reduced. Two interesting features have been observed. One is the detection of the coherent mode around 100 kHz in H-mode. This mode appears about 10 ms after L to H transition. The timing corresponds to the formation of a steep density and temperature gradient in the edge region. The other is the enhancement of the fluctuations with the frequency higher than 300 kHz in H-mode in contrast to the reduction of the fluctuations with the frequency lower than 100 kHz. The Doppler shift is observed in the complex auto-power spectrum of the reflected wave when the plasma is actively moved. We have confirmed that the movement of the plasma is appropriately measured by using the low pass filter. The reflectometer can be used to measure the density profile by using a low pass filter even when the runaway phase phenomenon occurs. (author). 150 refs

Nonlinear evolution of the mode structure of ELMs in realistic ASDEX Upgrade geometry

Energy Technology Data Exchange (ETDEWEB)

Krebs, Isabel; Hoelzl, Matthias; Lackner, Karl; Guenter, Sibylle [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, Garching (Germany); Collaboration: The ASDEX Upgrade Team

2013-07-01

Edge-localized modes (ELMs) are edge instabilities in H-mode plasmas, which eject particles and energy. The suitability of the H-mode for future fusion reactors depends crucially on the exact ELM dynamics as they can damage plasma facing components if too large. We have simulated ELMs in ASDEX Upgrade geometry using the nonlinear MHD code JOREK. Emphasis was put on the mode structure evolution in the early ELM phase which is characterized by the exponential growth of the unstable toroidal Fourier harmonics followed by a phase of saturation. In the linear phase, toroidal harmonics grow independently, whereas at larger amplitudes, the nonlinear interaction between the toroidal harmonics influences their growth and structure. Prior to mode saturation, the evolution of the mode structure can be reproduced well by a simple quadratic mode-interaction model, which yields a possible explanation for the strong n=1 component of type-I ELMs observed in ASDEX Upgrade. In the linear phase of the simulations, intermediate toroidal mode numbers (n 6-14) are most unstable as predicted by the peeling-ballooning model. But non-linearly, the n=1 component becomes important due to an energy transfer from pairs of linearly dominant toroidal harmonics with neighboring mode numbers to the n=1. The latter thereby changes its spatial structure.

Towards Indoor Transportation Mode Detection using Mobile Sensing

DEFF Research Database (Denmark)

Prentow, Thor Siiger; Blunck, Henrik; Kjærgaard, Mikkel Baun

2015-01-01

Transportation mode detection is a growing field of research, in which a variety of methods have been developed for detecting transportation modes foremost for outdoor travels. It has been employed in application areas such as public transportation, environmental footprint profiling, and context......-aware mobile assistants. For indoor travels the problem of transportation mode detection has received comparatively little attention, even though diverse transportation modes, such as biking, electric vehicles, and scooters, are used indoors, especially in large building complexes. The potential applications...... are diverse, may also extend beyond indoor variants of the above outdoor applications, and include, e.g., scheduling and progress tracking for mobile workers, management of vehicular resources, and navigation support. However, for indoor transportation mode detection, both the physical environment as well...

Manipulating Rayleigh-Taylor Growth Using Adjoints

Science.gov (United States)

Kord, Ali; Capecelatro, Jesse

2017-11-01

It has been observed that initial interfacial perturbations affect the growth of Rayleigh-Taylor (RT) instabilities. However, it remains to be seen to what extent the perturbations alter the RT growth rate. Direct numerical simulations (DNS) provide a powerful means for studying the effects of initial conditions (IC) on the growth rate. However, a brute-force approach for identifying optimal initial perturbations is not practical via DNS. In addition, identifying sensitivity of the RT growth to the large number of parameters used in defining the IC is computationally expensive. A discrete adjoint is formulated to measure sensitivities of multi-mode RT growth to ICs in a high-order finite difference framework. The sensitivity is used as a search direction for adjusting the initial perturbations to both maximize and suppress the RT growth rate during its non-linear regime. The modes that contribute the greatest sensitivity are identified, and optimized perturbation energy spectrum are reported. PhD Student, Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI.

Growth characteristics of liquid cultures increase the reliability of presumptive identification of Mycobacterium tuberculosis complex.

Science.gov (United States)

Pinhata, Juliana Maira Watanabe; Felippe, Isis Moreira; Gallo, Juliana Failde; Chimara, Erica; Ferrazoli, Lucilaine; de Oliveira, Rosangela Siqueira

2018-04-23

We evaluated the microscopic and macroscopic characteristics of mycobacteria growth indicator tube (MGIT) cultures for the presumptive identification of the Mycobacterium tuberculosis complex (MTBC) and assessed the reliability of this strategy for correctly directing isolates to drug susceptibility testing (DST) or species identification. A total of 1526 isolates of mycobacteria received at the Instituto Adolfo Lutz were prospectively subjected to presumptive identification by the observation of growth characteristics along with cord formation detection via microscopy. The presumptive identification showed a sensitivity, specificity and accuracy of 98.8, 92.5 and 97.9 %, respectively. Macroscopic analysis of MTBC isolates that would have been erroneously classified as non-tuberculous mycobacteria based solely on microscopic morphology enabled us to direct them rapidly to DST, representing a substantial gain to patients. In conclusion, the growth characteristics of mycobacteria in MGIT, when considered along with cord formation, increased the reliability of the presumptive identification, which has a great impact on the laboratory budget and turnaround times.

Alternative binding modes identified for growth and differentiation factor-associated serum protein (GASP) family antagonism of myostatin.

Science.gov (United States)

Walker, Ryan G; Angerman, Elizabeth B; Kattamuri, Chandramohan; Lee, Yun-Sil; Lee, Se-Jin; Thompson, Thomas B

2015-03-20

Myostatin, a member of the TGF-β family of ligands, is a strong negative regulator of muscle growth. As such, it is a prime therapeutic target for muscle wasting disorders. Similar to other TGF-β family ligands, myostatin is neutralized by binding one of a number of structurally diverse antagonists. Included are the antagonists GASP-1 and GASP-2, which are unique in that they specifically antagonize myostatin. However, little is known from a structural standpoint describing the interactions of GASP antagonists with myostatin. Here, we present the First low resolution solution structure of myostatin-free and myostatin-bound states of GASP-1 and GASP-2. Our studies have revealed GASP-1, which is 100 times more potent than GASP-2, preferentially binds myostatin in an asymmetrical 1:1 complex, whereas GASP-2 binds in a symmetrical 2:1 complex. Additionally, C-terminal truncations of GASP-1 result in less potent myostatin inhibitors that form a 2:1 complex, suggesting that the C-terminal domains of GASP-1 are the primary mediators for asymmetric complex formation. Overall, this study provides a new perspective on TGF-β antagonism, where closely related antagonists can utilize different ligand-binding strategies. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Optical-domain Compensation for Coupling between Optical Fiber Conjugate Vortex Modes

DEFF Research Database (Denmark)

Lyubopytov, Vladimir S.; Tatarczak, Anna; Lu, Xiaofeng

2016-01-01

We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation.......We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation....

Linear studies of resistive interchange modes in a cylindrical reversed field pinch

International Nuclear Information System (INIS)

Mirin, A.A.; O'Neill, N.J.; Killeen, J.; Bonugli, R.J.; Ellis, M.J.

1986-01-01

Resistive interchange modes in a cylindrical reversed field pinch are studied using a one-dimensional, linear, compressible initial value code. Separate equations for the electron and ion temperature perturbations are solved. Hall terms and the thermal force vector are included in Ohm's law. Anisotropic thermal conductivity and viscosity are included in the code model. Calculations are carried out for various values of poloidal and toroidal mode number, Lundquist number, Suydam parameter, Hall parameter, thermal conductivity, viscosity, etc., with respect to uniform density equilibria known to be stable to tearing modes. It is shown that in the cold ion limit sufficiently large Hall terms cause all modes that are tested to become stable. However for T/sub i/ = T/sub e/ and ignoring the effects of viscosity and thermal conductivity, there is a critical value of the ratio of Alfven to ion cyclotron frequency above which the ''even'' mode not only dominates the ''odd'' mode but is likely to have a growth rate significantly larger than that of the odd mode in the absence of Hall terms. Inclusion of a classical tensor thermal conductivity, while having little effect on the odd mode in the absence of Hall terms, does stabilize the even mode for sufficiently large Hall parameter. Inclusion of a classical tensor viscosity reduces the growth rate of (but does not necessarily stabilize) the odd mode. Inclusion of Hall and thermal force terms, tensor thermal conductivity and tensor viscosity causes all modes that are tested to stabilize. Results are compared to other contemporary studies

Real-time observation of epitaxial crystal growth in gaseous environment using x-ray diffraction and x-ray reflectometry

International Nuclear Information System (INIS)

Kawamura, Tomoaki; Bhunia, Satyaban; Watanabe, Yoshio; Fujikawa, Seiji

2008-01-01

We made the x-ray diffractometer combined with the MOCVD growth system for the real-time observation of epitaxial growth in gaseous environment, and investigated the growth mechanism of InP crystals. Changes of the (-5/2 O) Bragg diffraction during the growth revealed that the growth starts immediately after the In source has been supplied and gradually stopped, owing to the migrating In atoms on the surface. Additionally, one can easily determine the growth modes, including 3-dimensional mode, layer-by-layer mode, and step-flow mode, by observing the change of x-ray reflectivity with various growth conditions. (author)

Mode II interlaminar fracture of graphite/epoxy and graphite/PEEK

Science.gov (United States)

Carlsson, L. A.; Gillespie, J. W.; Trethewey, B. R.

1986-01-01

The end notched flexure (ENF) specimen is employed in an investigation of the interlaminar fracture toughness in Mode II (skew symmetric shear) loading of unidirectional graphite/epoxy and graphite/PEEK composites. Important experimental parameters such as the influence of precracking and the data reduction scheme for the Mode II toughness are discussed. Nonlinear load-deflection response is significant for the tough thermoplastic resin composite but is also present for the brittle thermoset composite. The observed nonlinearities, which are highly rate dependent, are attributed to a combination of slow stable crack growth preceding unstable crack growth and material inelastic behavior in the process zone around the crack tip.

Effect of secondary electron emission on Jean's instability in a complex plasma in the presence of nonthermal ions

International Nuclear Information System (INIS)

Sarkar, Susmita; Maity, Saumyen; Banerjee, Soumyajyoti

2011-01-01

In this paper, we have investigated the role of secondary electron emission on Jean's instability in a complex plasma in the presence of nonthermal ions. The equilibrium dust surface potential has been considered negative and hence primary and secondary electron temperatures are equal. Such plasma consists of three components: Boltzman distributed electrons, nonthermal ions and negatively charged inertial dust grains. From the linear dispersion relation, we have calculated the real frequency and growth rate of Jean's instability. Numerically, we have shown that for strong ion nonthermality Jean's mode is unstable. Growth of the instability reduces and the real part of the wave frequency increases with increasing secondary electron emission from dust grains. Hence, strong secondary electron emission suppresses Jean's instability in a complex plasma even when ion nonthermality is strong and equilibrium dust charge is negative.

Growth and smolting in lower-mode Atlantic Salmon stocked into the Penobscot River, Maine

Science.gov (United States)

Zydlewski, Joseph D.; O'Malley, Andrew; Cox, Oliver; Ruksznis, Peter; Trial, Joan G.

2014-01-01

Restoration of Atlantic Salmon Salmo salar in Maine has relied on hatchery-produced fry and smolts for critical stocking strategies. Stocking fry minimizes domestication selection, but these fish have poor survival. Conversely, stocked smolts have little freshwater experience but provide higher adult returns. Lower-mode (LM) fish, those not growing fast enough to ensure smolting by the time of stocking, are a by-product of the smolt program and are an intermediate hatchery product. From 2002 to 2009, between 70,000 and 170,000 marked LM Atlantic Salmon were stocked into the Pleasant River (a tributary in the Penobscot River drainage, Maine) in late September to early October. These fish were recaptured as actively migrating smolts (screw trapping), as nonmigrants (electrofishing), and as returning adults to the Penobscot River (Veazie Dam trap). Fork length (FL) was measured and a scale sample was taken to retrospectively estimate FL at winter annulus one (FW1) using the intercept-corrected direct proportion model. The LM fish were observed to migrate as age-1, age-2, and infrequently as age-3 smolts. Those migrating as age-1 smolts had a distinctly larger estimated FL at FW1 (>112 mm) than those that remained in the river for at least one additional year. At the time of migration, age-2 and age-3 smolts were substantially larger than age-1 smolts. Returning adult Atlantic Salmon of LM origin had estimated FLs at FW1 that corresponded to smolt age (greater FL for age 1 than age 2). The LM product produces both age-1 and age-2 smolts that have greater freshwater experience than hatchery smolts and may have growth and fitness advantages. The data from this study will allow managers to better assess the probability of smolting age and manipulate hatchery growth rates to produce a targeted-size LM product.

Mathematical modeling of the crack growth in linear elastic isotropic materials by conventional fracture mechanics approaches and by molecular dynamics method: crack propagation direction angle under mixed mode loading

Science.gov (United States)

Stepanova, Larisa; Bronnikov, Sergej

2018-03-01

The crack growth directional angles in the isotropic linear elastic plane with the central crack under mixed-mode loading conditions for the full range of the mixity parameter are found. Two fracture criteria of traditional linear fracture mechanics (maximum tangential stress and minimum strain energy density criteria) are used. Atomistic simulations of the central crack growth process in an infinite plane medium under mixed-mode loading using Large-scale Molecular Massively Parallel Simulator (LAMMPS), a classical molecular dynamics code, are performed. The inter-atomic potential used in this investigation is Embedded Atom Method (EAM) potential. The plane specimens with initial central crack were subjected to Mixed-Mode loadings. The simulation cell contains 400000 atoms. The crack propagation direction angles under different values of the mixity parameter in a wide range of values from pure tensile loading to pure shear loading in a wide diapason of temperatures (from 0.1 К to 800 К) are obtained and analyzed. It is shown that the crack propagation direction angles obtained by molecular dynamics method coincide with the crack propagation direction angles given by the multi-parameter fracture criteria based on the strain energy density and the multi-parameter description of the crack-tip fields.

Crystallization and preliminary X-ray analysis of the complexes between a Fab and two forms of human insulin-like growth factor II

International Nuclear Information System (INIS)

Newman, Janet; Cohen, Edward H.; Cosgrove, Leah; Kopacz, Kris; Dransfield, Daniel T.; Adams, Timothy E.; Peat, Thomas S.

2009-01-01

Complexes of both hIGF-II and hIGF-IIE with a Fab have been crystallized and investigated by X-ray analysis. Elevated expression of insulin-like growth factor II (IGF-II) is frequently observed in a variety of human malignancies, including breast, colon and liver cancer. As IGF-II can deliver a mitogenic signal through both the type 1 insulin-like growth factor receptor (IGF-IR) and an alternately spliced form of the insulin receptor (IR-A), neutralizing the biological activity of this growth factor directly is an attractive therapeutic option. One method of doing this would be to find antibodies that bind tightly and specifically to the peptide, which could be used as protein therapeutics to lower the peptide levels in vivo and/or to block the peptide from binding to the IGF-IR or IR-A. To address this, Fabs were selected from a phage-display library using a biotinylated precursor form of the growth factor known as IGF-IIE as a target. Fabs were isolated that were specific for the E-domain C-terminal extension and for mature IGF-II. Four Fabs selected from the library were produced, complexed with IGF-II and set up in crystallization trials. One of the Fab–IGF-II complexes (M64-F02–IGF-II) crystallized readily, yielding crystals that diffracted to 2.2 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 50.7, b = 106.9, c = 110.7 Å. There was one molecule of the complete complex in the asymmetric unit. The same Fab was also crystallized with a longer form of the growth factor, IGF-IIE. This complex crystallized in space group P2 1 2 1 2 1 , with unit-cell parameters a = 50.7, b = 107, c = 111.5 Å, and also diffracted X-rays to 2.2 Å resolution

Benchmark studies of the gyro-Landau-fluid code and gyro-kinetic codes on kinetic ballooning modes

Energy Technology Data Exchange (ETDEWEB)

Tang, T. F. [Dalian University of Technology, Dalian 116024 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Ma, C. H. [Fusion Simulation Center, School of Physics, Peking University, Beijing (China); Bass, E. M.; Candy, J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Holland, C. [University of California San Diego, La Jolla, California 92093-0429 (United States)

2016-03-15

A Gyro-Landau-Fluid (GLF) 3 + 1 model has been recently implemented in BOUT++ framework, which contains full Finite-Larmor-Radius effects, Landau damping, and toroidal resonance [Ma et al., Phys. Plasmas 22, 055903 (2015)]. A linear global beta scan has been conducted using the JET-like circular equilibria (cbm18 series), showing that the unstable modes are kinetic ballooning modes (KBMs). In this work, we use the GYRO code, which is a gyrokinetic continuum code widely used for simulation of the plasma microturbulence, to benchmark with GLF 3 + 1 code on KBMs. To verify our code on the KBM case, we first perform the beta scan based on “Cyclone base case parameter set.” We find that the growth rate is almost the same for two codes, and the KBM mode is further destabilized as beta increases. For JET-like global circular equilibria, as the modes localize in peak pressure gradient region, a linear local beta scan using the same set of equilibria has been performed at this position for comparison. With the drift kinetic electron module in the GYRO code by including small electron-electron collision to damp electron modes, GYRO generated mode structures and parity suggest that they are kinetic ballooning modes, and the growth rate is comparable to the GLF results. However, a radial scan of the pedestal for a particular set of cbm18 equilibria, using GYRO code, shows different trends for the low-n and high-n modes. The low-n modes show that the linear growth rate peaks at peak pressure gradient position as GLF results. However, for high-n modes, the growth rate of the most unstable mode shifts outward to the bottom of pedestal and the real frequency of what was originally the KBMs in ion diamagnetic drift direction steadily approaches and crosses over to the electron diamagnetic drift direction.

Dynamic feedback for multi-mode plasma instabilities

International Nuclear Information System (INIS)

Sen, A.K.

1978-01-01

Constant feedback, which has been used exclusively, fails to stabilize more than one mode of a plasma instability. It is shown that a suitable dynamic or frequency-dependent feedback can stabilize all modes. Methods are developed in which such a feedback structure can be chosen in terms of its poles and zeros in relation to those of the plasma transfer function in the complex frequency plane. The synthesis procedure for such a feedback structure, in the form of an integrated electronic circuit is also discussed. As an example, a dynamic feedback for multi-mode stabilization of a collisional drift wave instability is developed in detail. (author)

Analysis of current diffusive ballooning mode in tokamaks

International Nuclear Information System (INIS)

Uchida, M.; Fukuyama, A.; Itoh, S.-I.; Yagi, M.

1999-12-01

The effect of finite gyroradius on the current diffusive ballooning mode is examined. Starting from the reduced MHD equations including turbulent transports, coupling with drift motion and finite gyroradius effect of ions, we derive a ballooning mode equation with complex transport coefficients. The eigenfrequency, saturation level and thermal diffusivity are evaluated numerically from the marginal stability condition. Preliminary results of their parameter dependence is presented. (author)

On the role of resonances in double-mode pulsation

International Nuclear Information System (INIS)

Dziembowski, W.; Kovacs, G.

1984-01-01

Simultaneous effects of resonant coupling and non-linear saturation of linear driving mechanism on the finite amplitude solution of multi-modal pulsation problem and on its stability are investigated. Both effects are calculated in the lowest order of approximation in terms of amplitudes. It is shown that the 2:1 resonance between one of the two linearly unstable modes and a higher frequency mode causes double-mode (fundamental and first overtone) pulsation. In a certain range of parameters, such as the frequency mismatch, the linear growth and damping rates, it is the only stable solution of the problem. (author)

Tearing modes in tokamaks with lower hybrid current drive

International Nuclear Information System (INIS)

Xu, X.Q.

1990-08-01

In this paper, the effect of current drive on the tearing modes in the semi-collisional regime is analyzed using the drift-kinetic equation. A collisional operator is developed to model electron parallel conductivity. For the pure tearing modes the linear and quasilinear growth rates in the Rutherford regimes have been found to have roughly the same forms with a modified resistivity as without current drive. One interesting result is the prediction of a new instability. This instability, driven by the current gradient inside the tearing mode layer, is possibly related to MHD behavior observed in these experiments. 9 refs

ELMs and constraints on the H-mode pedestal: A model based on peeling-ballooning modes

International Nuclear Information System (INIS)

Snyder, P.B.

2002-01-01

Maximizing the pedestal height while maintaining acceptable ELMs is a key issue for optimizing tokamak performance. We present a model for ELMs and pedestal constraints based upon theoretical analysis of edge instabilities which can limit the pedestal height and drive ELMs. Sharp pedestal pressure gradients drive large bootstrap currents which play a complex dual role in the stability physics. Consequently, the dominant modes are often intermediate-n coupled 'peeling-ballooning' modes, driven both by current and the pressure gradient. A highly efficient new MHD code, ELITE, is used to study these modes, and calculate quantitative stability constraints on the pedestal, including direct constraints on the pedestal height. A model of various ELM types is developed, and quantitatively compared to data from several tokamaks. A number of observations agree with predictions, including ELM onset times, ELM depth, and variation in pedestal height with discharge shape. Projections of pedestal stability constraints for Next Step designs, and nonlinear simulations of peeling-ballooning modes using the BOUT code are also presented. (author)

Experimental studies of tearing mode and resistive wall mode dynamics in the reversed field pinch configuration

International Nuclear Information System (INIS)

Malmberg, Jenny-Ann

2003-06-01

locked modes. The internal and external non-resonant resistive wall modes grow on the time scale of the shell penetration time. These growth rates depend on the RFP equilibrium. The internal non-resonant resistive wall modes dominate in Extrap T2R, especially for shallow reversed discharges. The external non-resonant modes grow solely in deep reversal discharges

Analysis of Statoliths Displacement in Chara Rhizoids for Validating the Microgravity-Simulation Quality of Clinorotation Modes

Science.gov (United States)

Krause, Lars; Braun, Markus; Hauslage, Jens; Hemmersbach, Ruth

2018-05-01

In single-celled rhizoids of the green algae Chara, positively gravitropic growth is governed by statoliths kept in a dynamically stable position 10-25 μ m above the cell tip by a complex interaction of gravity and actomyosin forces. Any deviation of the tube-like cells from the tip-downward orientation causes statoliths to sediment onto the gravisensitive subapical cell flank which initiates a gravitropic curvature response. Microgravity experiments have shown that abolishing the net tip-directed gravity force results in an actomyosin-mediated axial displacement of statoliths away from the cell tip. The present study was performed to critically assess the quality of microgravity simulation provided by different operational modes of a Random Positioning Machine (RPM) running with one axis (2D mode) or two axes (3D mode) and different rotational speeds (2D), speed ranges and directions (3D). The effects of 2D and 3D rotation were compared with data from experiments in real microgravity conditions (MAXUS sounding rocket missions). Rotational speeds in the range of 60-85 rpm in 2D and 3D modes resulted in a similar kinetics of statolith displacement as compared to real microgravity data, while slower clinorotation (2-11 rpm) caused a reduced axial displacement and a more dispersed arrangement of statoliths closer to the cell tip. Increasing the complexity of rotation by adding a second rotation axis in case of 3D clinorotation did not increase the quality of microgravity simulation, however, increased side effects such as the level of vibrations resulting in a more dispersed arrangement of statoliths. In conclusion, fast 2D clinorotation provides the most appropriate microgravity simulation for investigating the graviperception mechanism in Chara rhizoids, whereas slower clinorotation speeds and rotating samples around two axes do not improve the quality of microgravity simulation.

Reaction-diffusion controlled growth of complex structures

Science.gov (United States)

Noorduin, Willem; Mahadevan, L.; Aizenberg, Joanna

2013-03-01

Understanding how the emergence of complex forms and shapes in biominerals came about is both of fundamental and practical interest. Although biomineralization processes and organization strategies to give higher order architectures have been studied extensively, synthetic approaches to mimic these self-assembled structures are highly complex and have been difficult to emulate, let alone replicate. The emergence of solution patterns has been found in reaction-diffusion systems such as Turing patterns and the BZ reaction. Intrigued by this spontaneous formation of complexity we explored if similar processes can lead to patterns in the solid state. We here identify a reaction-diffusion system in which the shape of the solidified products is a direct readout of the environmental conditions. Based on insights in the underlying mechanism, we developed a toolbox of engineering strategies to deterministically sculpt patterns and shapes, and combine different morphologies to create a landscape of hierarchical multi scale-complex tectonic architectures with unprecedented levels of complexity. These findings may hold profound implications for understanding, mimicking and ultimately expanding upon nature's morphogenesis strategies, allowing the synthesis of advanced highly complex microscale materials and devices. WLN acknowledges the Netherlands Organization for Scientific Research for financial support

Field measurements of hygroscopic properties and state of mixing of nucleation mode particles

Directory of Open Access Journals (Sweden)

M. Väkevä

2002-01-01

Full Text Available An Ultrafine Tandem Differential Mobility Analyser (UF-TDMA has been used in several field campaigns over the last few years. The investigations were focused on the origin and properties of nucleation event aerosols, which are observed frequently in various environments. This paper gives a summary of the results of 10 nm and 20 nm particle hygroscopic properties from different measurement sites: an urban site, an urban background site and a forest site in Finland and a coastal site in western Ireland. The data can be classified in four hygroscopic growth classes: hydrofobic, less-hygroscopic, more-hygroscopic and sea-salt. Similar classification has been earlier presented for Aitken and accumulation mode particles. In urban air, the summertime 10 nm particles showed varying less-hygroscopic growth behaviour, while winter time 10 nm and 20 nm particles were externally mixed with two different hygroscopic growth modes. The forest measurements revealed diurnal behaviour of hygroscopic growth, with high growth factors at day time and lower during night. The urban background particles had growth behaviour similar to the urban and forest measurement sites depending on the origin of the observed particles. The coastal measurements were strongly affected by air mass history. Both 10 nm and 20 nm particles were hygroscopic in marine background air. The 10 nm particles produced during clean nucleation burst periods were hydrofobic. Diurnal variation and higher growth factors of 10 nm particles were observed in air affected by other source regions. External mixing was occasionally observed at all the sites, but incidents with more than two growth modes were extremely rare.

Time dependent fracture growth in intact crystalline rock: new laboratory procedures

International Nuclear Information System (INIS)

Backers, T.; Stephansson, O.

2008-01-01

Short term laboratory tests to determine the strength of rock material are commonly used to assess stability of rock excavations. However, loading the rock below its short term strength may lead to delayed failure due to slow stable fracture growth. This time-dependent phenomenon is called subcritical fracture growth. A fracture mechanics based approach is applied in this study to determine the parameters describing subcritical fracture growth under Mode Ⅰ (tensile) and Mode Ⅱ (in-plane shear) loading in terms of the stress intensity factors of saturated granodiorite from the) Aespoe HRL. A statistical method is applied to data from three-point bending (tension) and Punch-Through Shear with Confining Pressure, PTS/CP, (shear) experiments. One population of each set-up was subjected to rapid loading tests yielding a strength probability distribution. A second population was loaded up to a certain fraction of the statistical percentage for failure and the time-to-failure was determined. From these two populations the subcritical fracture growth parameters were determined successfully. Earlier studies demonstrated subcritical fracture growth under Mode I loading conditions, but this study shows that under a Mode Ⅱ load time-dependent fracture growth exists as well. (authors)

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

Science.gov (United States)

Asahi, Y.; Ishizawa, A.; Watanabe, T.-H.; Tsutsui, H.; Tsuji-Iio, S.

2014-05-01

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

Biochemical investigation of yttrium(III) complex containing 1,10-phenanthroline: DNA binding and antibacterial activity.

Science.gov (United States)

Khorasani-Motlagh, Mozhgan; Noroozifar, Meissam; Moodi, Asieh; Niroomand, Sona

2013-03-05

Characterization of the interaction between yttrium(III) complex containing 1,10-phenanthroline as ligand, [Y(phen)2Cl(OH2)3]Cl2⋅H2O, and DNA has been carried out by UV absorption, fluorescence spectra and viscosity measurements in order to investigate binding mode. The experimental results indicate that the yttrium(III) complex binds to DNA and absorption is decreasing in charge transfer band with the increase in amount of DNA. The binding constant (Kb) at different temperatures as well as thermodynamic parameters, enthalpy change (ΔH°) and entropy change (ΔS°), were calculated according to relevant fluorescent data and Vant' Hoff equation. The results of interaction mechanism studies, suggested that groove binding plays a major role in the binding of the complex and DNA. The activity of yttrium(III) complex against some bacteria was tested and antimicrobial screening tests shown growth inhibitory activity in the presence of yttrium(III) complex. Copyright © 2013 Elsevier B.V. All rights reserved.

Accelerated reliability demonstration under competing failure modes

International Nuclear Information System (INIS)

Luo, Wei; Zhang, Chun-hua; Chen, Xun; Tan, Yuan-yuan

2015-01-01

The conventional reliability demonstration tests are difficult to apply to products with competing failure modes due to the complexity of the lifetime models. This paper develops a testing methodology based on the reliability target allocation for reliability demonstration under competing failure modes at accelerated conditions. The specified reliability at mission time and the risk caused by sampling of the reliability target for products are allocated for each failure mode. The risk caused by degradation measurement fitting of the target for a product involving performance degradation is equally allocated to each degradation failure mode. According to the allocated targets, the accelerated life reliability demonstration test (ALRDT) plans for the failure modes are designed. The accelerated degradation reliability demonstration test plans and the associated ALRDT plans for the degradation failure modes are also designed. Next, the test plan and the decision rules for the products are designed. Additionally, the effects of the discreteness of sample size and accepted number of failures for failure modes on the actual risks caused by sampling for the products are investigated. - Highlights: • Accelerated reliability demonstration under competing failure modes is studied. • The method is based on the reliability target allocation involving the risks. • The test plan for the products is based on the plans for all the failure modes. • Both failure mode and degradation failure modes are considered. • The error of actual risks caused by sampling for the products is small enough

Resistive Wall Mode Stability and Control in the Reversed Field Pinch

International Nuclear Information System (INIS)

Yadikin, Dmitriy

2006-03-01

Control of MHD instabilities using a conducting wall together with external magnetic fields is an important route to improved performance and reliability in fusion devices. Active control of MHD modes is of interest for both the Advanced Tokamak and the Reversed Field Pinch (RFP) configurations. A wide range of unstable, current driven MHD modes is present in the RFP. An ideally conducting wall facing the plasma can in principle provide stabilization to these modes. However, a real, resistive wall characterized by a wall field diffusion time, cannot stabilize the ideal MHD modes unless they rotate with Alfvenic velocity, which is usually not the case. With a resistive wall, the ideal modes are converted into resistive wall modes (RWM) with growth rates comparable to the inverse wall time. Resistive wall modes have been studied in the EXTRAP T2R thin shell RFP device. Growth rates have been measured and found in agreement with linear MHD stability calculations. An advanced system for active control has been developed and installed on the EXTRAP T2R device. The system includes an array of 128 active saddle coils, fully covering the torus surface. Experiments on EXTRAP T2R have for the first time demonstrated simultaneous active suppression of multiple independent RWMs. In experiments with a partial array, coupling of different modes due to the limited number of feedback coils has been observed, in agreement with theory. Different feedback strategies, such as the intelligent shell, the rotating shell, and mode control have been studied. Further, feedback operation with different types of magnetic field sensors, measuring either the radial or the toroidal field components have been compared

Influence of toroidal rotation on tearing modes

Science.gov (United States)

Cai, Huishan; Cao, Jintao; Li, Ding

2017-10-01

Tearing modes stability analysis including toroidal rotation is studied. It is found that rotation affects the stability of tearing modes mainly through the interaction with resistive inner region of tearing mode. The coupling of magnetic curvature with centrifugal force and Coriolis force provides a perturbed perpendicular current, and a return parallel current is induced to affect the stability of tearing modes. Toroidal rotation plays a stable role, which depends on the magnitude of Mach number and adiabatic index Γ, and is independent on the direction of toroidal rotation. For Γ >1, the scaling of growth rate is changed for typical Mach number in present tokamaks. For Γ = 1 , the scaling keeps unchanged, and the effect of toroidal rotation is much less significant, compared with that for Γ >1. National Magnetic Confinement Fusion Science Program and National Science Foundation of China under Grants No. 2014GB106004, No. 2013GB111000, No. 11375189, No. 11075161 and No. 11275260, and Youth Innovation Promotion Association CAS.

Two modes of interaction of the single-stranded DNA-binding protein of bacteriophage T7 with the DNA polymerase-thioredoxin complex

KAUST Repository

Ghosh, Sharmistha; Hamdan, Samir; Richardson, Charles C.

2010-01-01

The DNA polymerase encoded by bacteriophage T7 has low processivity. Escherichia coli thioredoxin binds to a segment of 76 residues in the thumb subdomain of the polymerase and increases the processivity. The binding of thioredoxin leads to the formation of two basic loops, loops A and B, located within the thioredoxin-binding domain (TBD). Both loops interact with the acidic C terminus of the T7 helicase. A relatively weak electrostatic mode involves the C-terminal tail of the helicase and the TBD, whereas a high affinity interaction that does not involve the C-terminal tail occurs when the polymerase is in a polymerization mode. T7 gene 2.5 single-stranded DNA-binding protein (gp2.5) also has an acidic C-terminal tail. gp2.5 also has two modes of interaction with the polymerase, but both involve the C-terminal tail of gp2.5. An electrostatic interaction requires the basic residues in loops A and B, and gp2.5 binds to both loops with similar affinity as measured by surface plasmon resonance. When the polymerase is in a polymerization mode, the C terminus of gene 2.5 protein interacts with the polymerase in regions outside the TBD.gp2.5 increases the processivity of the polymerase-helicase complex during leading strand synthesis. When loop B of the TBD is altered, abortive DNA products are observed during leading strand synthesis. Loop B appears to play an important role in communication with the helicase and gp2.5, whereas loop A plays a stabilizing role in these interactions. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

Two modes of interaction of the single-stranded DNA-binding protein of bacteriophage T7 with the DNA polymerase-thioredoxin complex

KAUST Repository

Ghosh, Sharmistha

2010-04-06

The DNA polymerase encoded by bacteriophage T7 has low processivity. Escherichia coli thioredoxin binds to a segment of 76 residues in the thumb subdomain of the polymerase and increases the processivity. The binding of thioredoxin leads to the formation of two basic loops, loops A and B, located within the thioredoxin-binding domain (TBD). Both loops interact with the acidic C terminus of the T7 helicase. A relatively weak electrostatic mode involves the C-terminal tail of the helicase and the TBD, whereas a high affinity interaction that does not involve the C-terminal tail occurs when the polymerase is in a polymerization mode. T7 gene 2.5 single-stranded DNA-binding protein (gp2.5) also has an acidic C-terminal tail. gp2.5 also has two modes of interaction with the polymerase, but both involve the C-terminal tail of gp2.5. An electrostatic interaction requires the basic residues in loops A and B, and gp2.5 binds to both loops with similar affinity as measured by surface plasmon resonance. When the polymerase is in a polymerization mode, the C terminus of gene 2.5 protein interacts with the polymerase in regions outside the TBD.gp2.5 increases the processivity of the polymerase-helicase complex during leading strand synthesis. When loop B of the TBD is altered, abortive DNA products are observed during leading strand synthesis. Loop B appears to play an important role in communication with the helicase and gp2.5, whereas loop A plays a stabilizing role in these interactions. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.

Spatial arrangement of faults and opening-mode fractures

Science.gov (United States)

Laubach, S. E.; Lamarche, J.; Gauthier, B. D. M.; Dunne, W. M.; Sanderson, David J.

2018-03-01

Spatial arrangement is a fundamental characteristic of fracture arrays. The pattern of fault and opening-mode fracture positions in space defines structural heterogeneity and anisotropy in a rock volume, governs how faults and fractures affect fluid flow, and impacts our understanding of the initiation, propagation and interactions during the formation of fracture patterns. This special issue highlights recent progress with respect to characterizing and understanding the spatial arrangements of fault and fracture patterns, providing examples over a wide range of scales and structural settings. Five papers describe new methods and improvements of existing techniques to quantify spatial arrangement. One study unravels the time evolution of opening-mode fracture spatial arrangement, which are data needed to compare natural patterns with progressive fracture growth in kinematic and mechanical models. Three papers investigate the role of evolving diagenesis in localizing fractures by mechanical stratigraphy and nine discuss opening-mode fracture spatial arrangement. Two papers show the relevance of complex cluster patterns to unconventional reservoirs through examples of fractures in tight gas sandstone horizontal wells, and a study of fracture arrangement in shale. Four papers demonstrate the roles of folds in fracture localization and the development spatial patterns. One paper models along-fault friction and fluid pressure and their effects on fault-related fracture arrangement. Contributions address deformation band patterns in carbonate rocks and fault size and arrangement above a detachment fault. Three papers describe fault and fracture arrangements in basement terrains, and three document fracture patterns in shale. This collection of papers points toward improvement in field methods, continuing improvements in computer-based data analysis and creation of synthetic fracture patterns, and opportunities for further understanding fault and fracture attributes in

Fatigue Crack Growth Rate and Stress-Intensity Factor Corrections for Out-of-Plane Crack Growth

Science.gov (United States)

Forth, Scott C.; Herman, Dave J.; James, Mark A.

2003-01-01

Fatigue crack growth rate testing is performed by automated data collection systems that assume straight crack growth in the plane of symmetry and use standard polynomial solutions to compute crack length and stress-intensity factors from compliance or potential drop measurements. Visual measurements used to correct the collected data typically include only the horizontal crack length, which for cracks that propagate out-of-plane, under-estimates the crack growth rates and over-estimates the stress-intensity factors. The authors have devised an approach for correcting both the crack growth rates and stress-intensity factors based on two-dimensional mixed mode-I/II finite element analysis (FEA). The approach is used to correct out-of-plane data for 7050-T7451 and 2025-T6 aluminum alloys. Results indicate the correction process works well for high DeltaK levels but fails to capture the mixed-mode effects at DeltaK levels approaching threshold (da/dN approximately 10(exp -10) meter/cycle).

Resistive effects on line-tied magnetohydrodynamic modes in cylindrical geometry

International Nuclear Information System (INIS)

Delzanno, Gian Luca; Evstatiev, E. G.; Finn, John M.

2007-01-01

An investigation of the effect of resistivity on the linear stability of line-tied magnetohydrodynamic (MHD) modes is presented in cylindrical geometry, based on the method recently developed in the paper by Evstatiev et al. [Phys. Plasmas 13, 072902 (2006)]. The method uses an expansion of the full solution of the problem in one-dimensional radial eigenfunctions. This method is applied to study sausage modes (m=0, m being the poloidal wavenumber), kink modes (m=1), and m=2 modes. All these modes can be resistively unstable. It is found that m≠0 modes can be unstable below the ideal MHD threshold due to resistive diffusion of the field lines, with growth rates proportional to resistivity. For these resistive modes, there is no indication of tearing, i.e., current sheets or boundary layers due to ideal MHD singularities. That is, resistivity acts globally on the whole plasma column and not in layers. Modes with m=0, on the other hand, can exist as tearing modes if the equilibrium axial magnetic field reverses sign within the plasma

The complexity of standing postural control in older adults: a modified detrended fluctuation analysis based upon the empirical mode decomposition algorithm.

Directory of Open Access Journals (Sweden)

Junhong Zhou

Full Text Available Human aging into senescence diminishes the capacity of the postural control system to adapt to the stressors of everyday life. Diminished adaptive capacity may be reflected by a loss of the fractal-like, multiscale complexity within the dynamics of standing postural sway (i.e., center-of-pressure, COP. We therefore studied the relationship between COP complexity and adaptive capacity in 22 older and 22 younger healthy adults. COP magnitude dynamics were assessed from raw data during quiet standing with eyes open and closed, and complexity was quantified with a new technique termed empirical mode decomposition embedded detrended fluctuation analysis (EMD-DFA. Adaptive capacity of the postural control system was assessed with the sharpened Romberg test. As compared to traditional DFA, EMD-DFA more accurately identified trends in COP data with intrinsic scales and produced short and long-term scaling exponents (i.e., α(Short, α(Long with greater reliability. The fractal-like properties of COP fluctuations were time-scale dependent and highly complex (i.e., α(Short values were close to one over relatively short time scales. As compared to younger adults, older adults demonstrated lower short-term COP complexity (i.e., greater α(Short values in both visual conditions (p>0.001. Closing the eyes decreased short-term COP complexity, yet this decrease was greater in older compared to younger adults (p<0.001. In older adults, those with higher short-term COP complexity exhibited better adaptive capacity as quantified by Romberg test performance (r(2 = 0.38, p<0.001. These results indicate that an age-related loss of COP complexity of magnitude series may reflect a clinically important reduction in postural control system functionality as a new biomarker.

Integrated two-section discrete mode laser

NARCIS (Netherlands)

Anandarajah, P.M.; Latkowski, S.; Browning, C.; Zhou, R.; O'Carroll, J.; Phelan, R.; Kelly, B.; O'Gorman, J.; Barry, L.P.

2012-01-01

The authors present the design and characterization of a novel integrated two-section discrete mode index patterned diode laser source. The two slotted regions etched into the laser ridge waveguide are formed in the same fabrication step as the ridge, thus avoiding the requirement for complex

Full melting of a two-dimensional complex plasma crystal triggered by localized pulsed laser heating

Science.gov (United States)

Couëdel, L.; Nosenko, V.; Rubin-Zuzic, M.; Zhdanov, S.; Elskens, Y.; Hall, T.; Ivlev, A. V.

2018-04-01

The full melting of a two-dimensional plasma crystal was induced in a principally stable monolayer by localized laser stimulation. Two distinct behaviors of the crystal after laser stimulation were observed depending on the amount of injected energy: (i) below a well-defined threshold, the laser melted area recrystallized; (ii) above the threshold, it expanded outwards in a similar fashion to mode-coupling instability-induced melting, rapidly destroying the crystalline order of the whole complex plasma monolayer. The reported experimental observations are due to the fluid mode-coupling instability, which can pump energy into the particle monolayer at a rate surpassing the heat transport and damping rates in the energetic localized melted spot, resulting in its further growth. This behavior exhibits remarkable similarities with impulsive spot heating in ordinary reactive matter.

Synergy of plasma resistivity and electron viscosity in mediating double tearing modes in cylindrical plasmas

International Nuclear Information System (INIS)

He Zhixiong; He, H D; Long, Y X; Mou, Z Z; Dong, J Q; Gao Zhe

2010-01-01

The linear behaviors of the double tearing mode (DTM) mediated by parallel electron viscosity and plasma resistivity in cylindrical plasmas with reversed magnetic shear and thus two resonant rational flux surfaces are numerically investigated in this paper. It is shown that DTMs mediated by electron viscosity alone behave similarly to the DTMs mediated by resistivity alone. DTMs mediated by electron viscosity are found to be enhanced by plasma resistivity, which is in such a range that the growth rate of the modes induced by the latter alone is comparable with that of the modes mediated by the former alone, and vice versa. Otherwise the growth rate of the modes is equal to the higher of the modes mediated by resistivity or electron viscosity alone when both resistivity and electron viscosity are taken into account. The enhancement is found to be closely related to the profiles of the stream function.

Bloch Modes and Evanescent Modes of Photonic Crystals: Weak Form Solutions Based on Accurate Interface Triangulation

Directory of Open Access Journals (Sweden)

Matthias Saba

2015-01-01

Full Text Available We propose a new approach to calculate the complex photonic band structure, both purely dispersive and evanescent Bloch modes of a finite range, of arbitrary three-dimensional photonic crystals. Our method, based on a well-established plane wave expansion and the weak form solution of Maxwell’s equations, computes the Fourier components of periodic structures composed of distinct homogeneous material domains from a triangulated mesh representation of the inter-material interfaces; this allows substantially more accurate representations of the geometry of complex photonic crystals than the conventional representation by a cubic voxel grid. Our method works for general two-phase composite materials, consisting of bi-anisotropic materials with tensor-valued dielectric and magnetic permittivities ε and μ and coupling matrices ς. We demonstrate for the Bragg mirror and a simple cubic crystal closely related to the Kelvin foam that relatively small numbers of Fourier components are sufficient to yield good convergence of the eigenvalues, making this method viable, despite its computational complexity. As an application, we use the single gyroid crystal to demonstrate that the consideration of both conventional and evanescent Bloch modes is necessary to predict the key features of the reflectance spectrum by analysis of the band structure, in particular for light incident along the cubic [111] direction.

Regular growth of systems of functions and systems of non-homogeneous convolution equations in convex domains of the complex plane

International Nuclear Information System (INIS)

Krivosheev, A S

2000-01-01

In this paper we introduce the notion of regular growth for a system of entire functions of finite order and type. This is a direct and natural generalization of the classical completely regular growth of an entire function. We obtain sufficient and necessary conditions for the solubility of a system of non-homogeneous convolution equations in convex domains of the complex plane. These conditions depend on whether the system of Laplace transforms of the analytic functionals that generate the convolution equations has regular growth. In the case of smooth convex domains, these solubility conditions form a criterion

The acid-labile subunit of the ternary insulin-like growth factor complex in cirrhosis: relation to liver dysfunction

DEFF Research Database (Denmark)

Møller, S; Juul, A; Becker, U

2000-01-01

BACKGROUND/AIMS: In the circulation, insulin-like growth factor-I (IGF-I) is bound in a trimeric complex of 150 kDa with IGF binding protein-3 (IGFBP-3) and the acid-labile subunit (ALS). Whereas circulating IGF-I and IGFBP-3 are reported to be low in patients with chronic liver failure, the leve...... with significant relations to liver dysfunction and other components of the IGF complex. A small hepatic extraction was found in controls, which suggests extrahepatic production of ALS. Future studies should focus on organ-specific removal of ALS.......BACKGROUND/AIMS: In the circulation, insulin-like growth factor-I (IGF-I) is bound in a trimeric complex of 150 kDa with IGF binding protein-3 (IGFBP-3) and the acid-labile subunit (ALS). Whereas circulating IGF-I and IGFBP-3 are reported to be low in patients with chronic liver failure, the level...... of ALS has not been described in relation to hepatic dysfunction. The aim of the present study was therefore to measure circulating and hepatic venous concentrations of ALS in relation to hepatic function and the IGF axis. METHODS: Twenty-five patients with cirrhosis (Child class A/B/C:5/10/10) and 30...

Dynamic behaviour of the high confinement mode of fusion plasmas

International Nuclear Information System (INIS)

Zohm, H.

1995-05-01

This paper describes the dynamic behaviour of the High Confinement mode (H-mode) of fusion plasmas, which is one of the most promising regimes of enhanced energy confinement in magnetic fusion research. The physics of the H-mode is not yet fully understood, and the detailed behaviour is complex. However, we establish a simple physics picture of the phenomenon. Although a first principles theory of the anomalous transport processes in a fusion plasma has not yet been given, we show that within the picture developed here, it is possible to describe the dynamic behaviour of the H-mode, namely the dynamics of the L-H transition and the occurrence of edge localized modes (ELMs). (orig.)

Monolithic mode locked DBR laser with multiple-bandgap MQW structure realized by selective area growth

Energy Technology Data Exchange (ETDEWEB)

Schilling, M.; Bouayad-Amine, J.; Feeser, T.; Haisch, H.; Kuehn, E.; Lach, E.; Satzke, K.; Weber, J.; Zielinski, E. [Alcatel Telecom, Stuttgart (Germany). Research Div.

1996-12-31

The realization of novel monolithically integrated multiple-segment pulse laser sources in InGaAsP MQW technology is reported. The MQW layers for all functional sections of these devices, the modulator, the active (gain) and the passive waveguide, as well as the Bragg section were grown in a single selective area growth (SAG) step by LP-MOVPE on SiO{sub 2} patterned 2 inch InP substrates. Due to a properly selected pattern geometry 3 different bandgap regions with smooth interfaces are thereby formed along the laser cavity. The more than 4 mm long DBR lasers which exhibit a threshold current as low as 30 mA were mode locked by an intra-cavity electroabsorption modulator applying a sinusoidal voltage at around 10 GHz. In this way an optical pulse train with pulse widths < 13 ps (measured with a streak camera) and high extinction ratio was generated. A time-bandwidth product of 0.5 close to the Fourier limit is obtained. This device is very attractive for signal generation in 40 Gb/s OTDM transmission systems at 1.55 {micro}m wavelength.

Zonal flow generation in collisionless trapped electron mode turbulence

International Nuclear Information System (INIS)

Anderson, J; Nordman, H; Singh, R; Weiland, J

2006-01-01

In the present work the generation of zonal flows in collisionless trapped electron mode (TEM) turbulence is studied analytically. A reduced model for TEM turbulence is utilized based on an advanced fluid model for reactive drift waves. An analytical expression for the zonal flow growth rate is derived and compared with the linear TEM growth, and its scaling with plasma parameters is examined for typical tokamak parameter values

Biking and Walking: The Position of Non-Motorised Transport Modes in Transport Systems

NARCIS (Netherlands)

Rietveld, Piet

2001-01-01

Long run developments such as income growth and urban sprawl lead one to expect a continuous decline of thecontribution of non-motorised transport modes to the performance of transport systems. In terms of the total number of trips, non-motorised transport modes have retained high shares, however.

Translation elicits a growth rate-dependent, genome-wide, differential protein production in Bacillus subtilis.

Science.gov (United States)

Borkowski, Olivier; Goelzer, Anne; Schaffer, Marc; Calabre, Magali; Mäder, Ulrike; Aymerich, Stéphane; Jules, Matthieu; Fromion, Vincent

2016-05-17

Complex regulatory programs control cell adaptation to environmental changes by setting condition-specific proteomes. In balanced growth, bacterial protein abundances depend on the dilution rate, transcript abundances and transcript-specific translation efficiencies. We revisited the current theory claiming the invariance of bacterial translation efficiency. By integrating genome-wide transcriptome datasets and datasets from a library of synthetic gfp-reporter fusions, we demonstrated that translation efficiencies in Bacillus subtilis decreased up to fourfold from slow to fast growth. The translation initiation regions elicited a growth rate-dependent, differential production of proteins without regulators, hence revealing a unique, hard-coded, growth rate-dependent mode of regulation. We combined model-based data analyses of transcript and protein abundances genome-wide and revealed that this global regulation is extensively used in B. subtilis We eventually developed a knowledge-based, three-step translation initiation model, experimentally challenged the model predictions and proposed that a growth rate-dependent drop in free ribosome abundance accounted for the differential protein production. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

Effects of compressibility on the resistive ballooning mode

International Nuclear Information System (INIS)

Hender, T.C.; Carreras, B.A.; Cooper, W.A.; Holmes, J.A.; Diamond, P.H.; Similon, P.L.

1983-09-01

The linear stability of the resistive ballooning mode, as described by the resistive MHD model, is investigated both analytically and numerically. When the pressure evolution is approximated by fluid convection (reduced MHD model), an instability driven by geodesic curvature, with a growth rate γ approx. eta/sup 1/3/β/sub rho//sup 2/3/, is found. For conditions relevant to the Impurity Study Experiment (ISX-B), it is shown that for modest poloidal beta (β/sub rho/ approx. = 1), high current, and relatively high temperatures, compressibility has a significant stabilizing influence, relative to the pressure convection model, for low toroidal mode number modes. However, at high β/sub rho/ (greater than or equal to 2), low current, and lower temperatures, compressibility has much less effect

Resistive m=o mode in reverse-field configurations

International Nuclear Information System (INIS)

Galvao, R.M.O.; Santiago, M.A.M.

1982-01-01

The resistive m=0 mode is studied. Where m is the azimuthal mode number in magnetic confinement configurations with parallel field lines such that the magnetic field reverses direction inside the plasma. A cylindrical plasma column which rotates rigidly with a rotation velocity Ω is considered. It is found that the growth rate of the mode γ scales differently with the plasma resistivity depending on whether Ω vanishes or not; γα sup(3/5) for Ω=0 and γα sup(1/3) for Ω different 0. When the Hall term is also included in the generalized Ohm's law, γα sup(1/2) is obtained. This last result is in disagreement with the results of Krappraff et al. (Author) [pt

Effect of sheared flows on neoclassical tearing modes

Energy Technology Data Exchange (ETDEWEB)

Sen, A [Institute for Plasma Research, Bhat, Gandhinagar (India); Chandra, D; Kaw, P [Institute for Plasma Research, Bhat, Gandhinagar (India); Bora, M P [Physics Dept., Gauhati University, Guwahati (India); Kruger, S [Tech-X, Boulder, CO (United States); Ramos, J [Plasma Science and Fusion Center, MIT, Cambridge, MA (United States)

2005-01-01

The influence of toroidal sheared equilibrium flows on the nonlinear evolution of classical and neoclassical tearing modes (NTMs) is studied through numerical solutions of a set of reduced generalized MHD equations that include viscous force effects based on neoclassical closures. In general, differential flow is found to have a strong stabilizing influence leading to lower saturated island widths for the classical (m/n = 2/1) mode and reduced growth rates for the (m/n = 3/1) neoclassical mode. Velocity shear on the other hand is seen to make a destabilizing contribution. An analytic model calculation, consisting of a generalized Rutherford island evolution equation that includes shear flow effects is also presented and the numerical results are discussed in the context of this model. (author)

A convection-allowing ensemble forecast based on the breeding growth mode and associated optimization of precipitation forecast

Science.gov (United States)

Li, Xiang; He, Hongrang; Chen, Chaohui; Miao, Ziqing; Bai, Shigang

2017-10-01

A convection-allowing ensemble forecast experiment on a squall line was conducted based on the breeding growth mode (BGM). Meanwhile, the probability matched mean (PMM) and neighborhood ensemble probability (NEP) methods were used to optimize the associated precipitation forecast. The ensemble forecast predicted the precipitation tendency accurately, which was closer to the observation than in the control forecast. For heavy rainfall, the precipitation center produced by the ensemble forecast was also better. The Fractions Skill Score (FSS) results indicated that the ensemble mean was skillful in light rainfall, while the PMM produced better probability distribution of precipitation for heavy rainfall. Preliminary results demonstrated that convection-allowing ensemble forecast could improve precipitation forecast skill through providing valuable probability forecasts. It is necessary to employ new methods, such as the PMM and NEP, to generate precipitation probability forecasts. Nonetheless, the lack of spread and the overprediction of precipitation by the ensemble members are still problems that need to be solved.

Single-mode coherent synchrotron radiation instability

Directory of Open Access Journals (Sweden)

S. Heifets

2003-06-01

Full Text Available The microwave instability driven by the coherent synchrotron radiation (CSR has been previously studied [S. Heifets and G. V. Stupakov, Phys. Rev. ST Accel. Beams 5, 054402 (2002] neglecting effect of the shielding caused by the finite beam pipe aperture. In practice, the unstable mode can be close to the shielding threshold where the spectrum of the radiation in a toroidal beam pipe is discrete. In this paper, the CSR instability is studied in the case when it is driven by a single synchronous mode. A system of equations for the beam-wave interaction is derived and its similarity to the 1D free-electron laser theory is demonstrated. In the linear regime, the growth rate of the instability is obtained and a transition to the case of continuous spectrum is discussed. The nonlinear evolution of the single-mode instability, both with and without synchrotron damping and quantum diffusion, is also studied.

The Spectral Web of stationary plasma equilibria. II. Internal modes

Science.gov (United States)

Goedbloed, J. P.

2018-03-01

The new method of the Spectral Web to calculate the spectrum of waves and instabilities of plasma equilibria with sizeable flows, developed in the preceding Paper I [Goedbloed, Phys. Plasmas 25, 032109 (2018)], is applied to a collection of classical magnetohydrodynamic instabilities operating in cylindrical plasmas with shear flow or rotation. After a review of the basic concepts of the complementary energy giving the solution path and the conjugate path, which together constitute the Spectral Web, the cylindrical model is presented and the spectral equations are derived. The first example concerns the internal kink instabilities of a cylindrical force-free magnetic field of constant α subjected to a parabolic shear flow profile. The old stability diagram and the associated growth rate calculations for static equilibria are replaced by a new intricate stability diagram and associated complex growth rates for the stationary model. The power of the Spectral Web method is demonstrated by showing that the two associated paths in the complex ω-plane nearly automatically guide to the new class of global Alfvén instabilities of the force-free configuration that would have been very hard to predict by other methods. The second example concerns the Rayleigh-Taylor instability of a rotating theta-pinch. The old literature is revisited and shown to suffer from inconsistencies that are remedied. The most global n = 1 instability and a cluster sequence of more local but much more unstable n =2 ,3 ,…∞ modes are located on separate solution paths in the hydrodynamic (HD) version of the instability, whereas they merge in the MHD version. The Spectral Web offers visual demonstration of the central position the HD flow continuum and of the MHD Alfvén and slow magneto-sonic continua in the respective spectra by connecting the discrete modes in the complex plane by physically meaningful curves towards the continua. The third example concerns the magneto-rotational instability

Mitigating impact of thermal and rectified radio-frequency sheath potentials on edge localized modes

Energy Technology Data Exchange (ETDEWEB)

Gui, B. [Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Lawerence Livermore National Lab, Livermore, California 94550 (United States); Xu, X. Q. [Lawerence Livermore National Lab, Livermore, California 94550 (United States); Myra, J. R.; D' Ippolito, D. A. [Lodestar Research Corporation, Boulder, Colorado 80301 (United States)

2014-11-15

The mitigating impact of thermal and rectified radio frequency (RF) sheath potentials on the peeling-ballooning modes is studied non-linearly by employing a two-fluid three-field simulation model based on the BOUT++ framework. Additional shear flow and the Kelvin-Helmholtz effect due to the thermal and rectified RF sheath potential are induced. It is found that the shear flow increases the growth rate while the K-H effect decreases the growth rate slightly when there is a density gradient, but the energy loss of these cases is suppressed in the nonlinear phase. The stronger external electrostatic field due to the sheaths has a more significant effect on the energy loss suppression. From this study, it is found the growth rate in the linear phase mainly determines the onset of edge-localized modes, while the mode spectrum width in the nonlinear phase has an important impact on the turbulent transport. The wider mode spectrum leads to weaker turbulent transport and results in a smaller energy loss. Due to the thermal sheath and rectified RF sheath potential in the scrape-off-layer, the modified shear flow tears apart the peeling-ballooning filament and makes the mode spectrum wider, resulting in less energy loss. The perturbed electric potential and the parallel current near the sheath region is also suppressed locally due to the sheath boundary condition.

Instability of g-mode oscillations in white dwarf stars

Science.gov (United States)

Keeley, D. A.

1979-01-01

A white dwarf model with M = 6 solar masses, Te = 12,000 K, and L = 1.2 x 10 to the 31st erg/sec provided by Cox has been tested for linear stability of radial oscillations. The radial mode instability first reported for this model by Cox, et al. (1979) has been confirmed. The growth rates obtained are comparable to the rates found by Cox. A sequence of l = 2 g-modes has also been found to be unstable. The e-folding times range from around 10 to the 11th periods for a 137 second mode (1 radial node) to less than 100 periods for a 629 second mode (17 nodes). It is likely that the latter rate is too high because the eigenfunction has been forced to vanish at the non-zero inner radius of the model, at which the Brunt-Vaisala frequency is barely less than the mode frequency.

Tearing mode dynamics and sawtooth oscillation in Hall-MHD

Science.gov (United States)

Ma, Zhiwei; Zhang, Wei; Wang, Sheng

2017-10-01

Tearing mode instability is one of the most important dynamic processes in space and laboratory plasmas. Hall effects, resulted from the decoupling of electron and ion motions, could cause the fast development and perturbation structure rotation of the tearing mode and become non-negligible. We independently developed high accuracy nonlinear MHD code (CLT) to study Hall effects on the dynamic evolution of tearing modes with Tokamak geometries. It is found that the rotation frequency of the mode in the electron diamagnetic direction is in a good agreement with analytical prediction. The linear growth rate increases with increase of the ion inertial length, which is contradictory to analytical solution in the slab geometry. We further find that the self-consistently generated rotation largely alters the dynamic behavior of the double tearing mode and the sawtooth oscillation. National Magnetic Confinement Fusion Science Program of China under Grant No. 2013GB104004 and 2013GB111004.

A MATHEMATICAL MODEL OF THERMAL POWER PLANTS SMOKE EXHAUSTERS INDUCTION MOTORS SYSTEM OPERATION MODES

Directory of Open Access Journals (Sweden)

K. M. Vasyliv

2017-06-01

Full Text Available Purpose. Development of a model-software complex (MSC for computer analysis of modes of the system of induction motors (IM of smoke exhausters of thermal power plant (TPP, the basic elements of which are mathematical models and corresponding software written in the programming language FORTRAN. Methodology. Mathematical model serves as a system of differential equations of electrical and mechanical condition. The equation of electric state is written in phase coordinates based on Kirchhoff's laws, and mechanical condition described by the d'Alembert equation. Mathematical model focuses on explicit numerical integration methods. Scientific novelty. The equation of state of electrical connections takes into account the mutual electromagnetic circuits for transformer of own needs (TON and induction motors and interdependence (in all possible combinations between: TON (from which motors powered and each of the two IM and blood pressure between themselves. The complex allows to simulate electromagnetic and electromechanical processes in transitional and steady, symmetric and asymmetric modes including modes of self-induction motors. Results. Complex is used for computer analysis of electromagnetic and electromechanical processes and established the basic laws of motion modes of starting, stopping and self-start of IM of smoke exhausters of the TPP unit. Practical value. The complex is suitable for computer analysis of modes of other similar units of own needs of thermal power plants.

Theory of energetic trapped particle-induced resistive interchange-ballooning modes

International Nuclear Information System (INIS)

Biglari, H.; Chen, L.

1986-02-01

A theory describing the influence of energetic trapped particles on resistive interchange-ballooning modes in tokamaks is presented. It is shown that a population of hot particles trapped in the region of adverse curvature can resonantly interact with and destabilize the resistive interchange mode, which is stable in their absence because of favorable average curvature. The mode is different from the usual resistive interchange mode not only in its destabilization mechanism, but also in that it has a real component to its frequency comparable to the precessional drift frequency of the rapidly circulating energetic species. Corresponding growth rate and threshold conditions for this trapped-particle-driven instability are derived and finite banana width effects are shown to have a stabilizing effect on the mode. Finally, the ballooning/tearing dispersion relation is generalized to include hot particles, so that both the ideal and the resistive modes are derivable in the appropriate limits. 23 refs., 7 figs

The Use of Contact Mode Atomic Force Microscopy in Aqueous Medium for Structural Analysis of Spinach Photosynthetic Complexes

Energy Technology Data Exchange (ETDEWEB)

Phuthong, Witchukorn; Huang, Zubin; Wittkopp, Tyler M.; Sznee, Kinga; Heinnickel, Mark L.; Dekker, Jan P.; Frese, Raoul N.; Prinz, Fritz B.; Grossman, Arthur R.

2015-07-28

To investigate the dynamics of photosynthetic pigment-protein complexes in vascular plants at high resolution in an aqueous environment, membrane-protruding oxygen-evolving complexes (OECs) associated with photosystem II (PSII) on spinach (Spinacia oleracea) grana membranes were examined using contact mode atomic force microscopy. This study represents, to our knowledge, the first use of atomic force microscopy to distinguish the putative large extrinsic loop of Photosystem II CP47 reaction center protein (CP47) from the putative oxygen-evolving enhancer proteins 1, 2, and 3 (PsbO, PsbP, and PsbQ) and large extrinsic loop of Photosystem II CP43 reaction center protein (CP43) in the PSII-OEC extrinsic domains of grana membranes under conditions resulting in the disordered arrangement of PSII-OEC particles. Moreover, we observed uncharacterized membrane particles that, based on their physical characteristics and electrophoretic analysis of the polypeptides associated with the grana samples, are hypothesized to be a domain of photosystem I that protrudes from the stromal face of single thylakoid bilayers. Our results are interpreted in the context of the results of others that were obtained using cryo-electron microscopy (and single particle analysis), negative staining and freeze-fracture electron microscopy, as well as previous atomic force microscopy studies.

The evolution of investments decision mode in China's telecommunication

Institute of Scientific and Technical Information of China (English)

ZHANG Ai-hua; ZHAO Lian-qiang; SHU Hua-ying

2007-01-01

This essay analyzes the data of Chinese telecommunication market, telecommunication investments and investment benefits over the past 20 years. On the basis of these data, the essay reviews Chinese changing telecommunication policies and discusses the major events in the course of China's telecommunication development. It is argued that telecommunication policies, regime backgrounds and market demand characteristics have a significant impact on investment decision mode in telecommunication industry. The evolution of network investments decision mode in China's telecommunication has corresponded to the transformation of these key factors. Considering the special events in the development of Chinese telecommunication as divisions, the essay discusses three stages of the evolution of investments decision mode in China's telecommunication. With the firm environment and problems that Chinese telecommunication operators have been facing since 2000 analyzed. it is demonstrated that Chinese telecommunication operators should change their mode of investment decision into the "profit-oriented investment decision mode" in order to achieve a high growth performance in the capital market,. This investment decision mode will result in increase of the investment profit with limited investment capital. The main procedure of profit-oriented investment decision mode is set out, which is abstracted to a mathematical model eventually.

Active control of multiple resistive wall modes

International Nuclear Information System (INIS)

Brunsell, P. R.; Yadikin, D.; Gregoratto, D.; Paccagnella, R.; Liu, Y. Q.; Bolzonella, T.; Cecconello, M.; Drake, J. R.; Kuldkepp, M.; Manduchi, G.; Marchiori, G.; Marrelli, L.; Partin, P.; Menmuir, S.; Ortolani, S.; Rachlew, E.; Spizzo, S.; Zanca, P.

2005-01-01

Active magnetic feedback suppression of resistive wall modes is of common interest for several fusion concepts relying on close conducting walls for stabilization of ideal magnetohydrodynamic (MHD) modes. In the advanced tokamak without plasma rotation the kink mode is not completely stabilized, but rather converted into an unstable resistive wall mode (RWM) with a growth time comparable to the wall magnetic flux penetration time. The reversed field pinch (RFP) is similar to the advanced tokamak in the sense that it uses a conducting wall for kink mode stabilization. Also both configurations are susceptible to resonant field error amplification of marginally stable modes. However, the RFP has a different RWM spectrum and, in general, a range of modes is unstable. Hence, the requirement for simultaneous feedback stabilization of multiple independent RWMs arises for the RFP configuration. Recent experiments on RWM feedback stabilization, performed in the RFP device EXTRAP T2R [1], are presented. The experimental results obtained are the first demonstration of simultaneous feedback control of multiple independent RWMs [2]. Using an array of active magnetic coils, a reproducible suppression of several RWMs is achieved for the duration of the discharge, 3-5 wall times, through feedback action. An array with 64 active saddle coils at 4 poloidal times 16 toroidal positions is used. The important issues of side band generation by the active coil array and the accompanying coupling of different unstable modes through the feedback action are addressed in this study. Open loop control experiments have been carried out to quantitatively study resonant field error amplification. (Author)

Skin effect modifications of the Resistive Wall Mode dynamics in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Villone, Fabio, E-mail: villone@unicas.it [Ass. Euratom/ENEA/CREATE, DIEI, Università di Cassino e del Lazio Meridionale, Via Di Biasio 43, 03043 Cassino, FR (Italy); Pustovitov, Vladimir D. [Institute of Tokamak Physics, National Research Centre ‘Kurchatov Institute’, Pl. Kurchatova 1, Moscow 123182 (Russian Federation)

2013-11-22

We present the first evidence of the skin-effect modification of the Resistive Wall Mode (RWM) dynamics in a tokamak. The computations are performed with the CarMa code, using its unique ability of treating volumetric 3D conducting structures. The results prove that conventional thin-wall models and codes, assuming the thin equivalent wall located on the inner side of a real (thick) wall, may fail to get accurate estimates of RWM growth rates, since the inclusion of the skin effect makes the growth rates always larger than otherwise. The difference is noticeable even for the conventional slow RWMs and becomes substantial for faster modes. Some possible equivalent thin-wall modeling approaches are also discussed.

Effect of oxygen plasma treatment on crystal growth mode at pentacene/Ni interface in organic thin-film transistors.

Science.gov (United States)

Song, Bang Joo; Hong, Kihyon; Kim, Woong-Kwon; Kim, Kisoo; Kim, Sungjun; Lee, Jong-Lam

2010-11-25

We report how treatment of nickel (Ni) with O(2) plasma affects the polarity of Ni surface, crystallinity of pentacene film on the Ni, and electrical properties of pentacene organic thin-film transistors (OTFTs) that use Ni as source-drain electrodes. The polar component of surface energy in Ni surface increased from 8.1 to 43.3 mJ/m(2) after O(2)-plasma treatment for 10 s. From X-ray photoelectron spectra and secondary electron emission spectra, we found that NiO(x) was formed on the O(2)-plasma-treated Ni surface and the work function of O(2)-plasma-treated Ni was 0.85 eV higher than that of untreated Ni. X-ray diffraction and atomic force microscopy measurements showed that pentacene molecules are well aligned as a thin-film and grains grow much larger on O(2)-plasma-treated Ni than on untreated Ni. This change in the growth mode is attributed to the reduction of interaction energy between pentacene and Ni due to formation of oxide at the Ni/pentacene interface. Thus, O(2)-plasma treatment promoted the growth of well-ordered pentacene film and lowered both the hole injection barrier and the contact resistance between Ni and pentacene by forming NiO(x), enhancing the electrical property of bottom-contact OTFTs.

Excitation of internal kink modes by trapped energetic beam ions

International Nuclear Information System (INIS)

Chen, L.; White, R.B.; Rosenbluth, M.N.

1983-10-01

Energetic trapped particles are shown to have a destabilizing effect on the internal kink mode in tokamaks. The plasma pressure threshold for the mode is lowered by the particles. The growth rate is near the ideal magnetohydrodynamic value, but the frequency is comparable to the trapped particle precission frequency. A model for the instability cycle gives stability properties, associated particle losses, and neutron emissivity consistent with the fishbone events observed in PDX

Investigation of magnetic modes in the ASDEX tokamak

International Nuclear Information System (INIS)

Zohm, H.

1990-10-01

Properties of MHD-modes in the ASDEX Tokamak have been investigated by application and further development of the MIRNOV-diagnostics, i.e. measurement of magnetic field fluctuations. In addition to evaluation methods supported by models, also a model-independent statistical data analysis makes sense. The very important physics of mode locking, i.e. the slowing-down of rotating modes is examined. An elaborated theoretical model allows an interpretation of experimental results. Especially interesting is the loss of the angular momentum of rotating plasmas by mode locking. Experiments for mode stabilisation and prevention of electric current breakdown are discussed. Additional MHD-processes under different plasma conditions are treated on the fundament of the devloped model ideas. The author shows that the main tokamak plasma is described very well by one-dimensional models with cylindrical geometry, while the boundary zone of the plasma demands a more complex analysis. In the appendix a concept for the investigation of the MHD-activity in ASDEX-Upgrade is discussed. (AH)

Nonlinear MHD and energetic particle modes in stellarators

International Nuclear Information System (INIS)

Strauss, H.R.; Fu, G.Y.; Park, W.; Breslau, J.; Sugiyama, L.E.

2003-01-01

The M3D (Multi-level 3D) project carries out simulation studies of plasmas using multiple levels of physics, geometry and grid models. The M3D code has been applied to ideal, resistive, two fluid, and hybrid simulations of compact quasi axisymmetric stellarators. When β exceeds a threshold, moderate toroidal mode number (n ∼ 10) modes grow exponentially, clearly distinguishable from the equilibrium evolution. The β limits are significantly higher than the infinite mode number ballooning limits. In the presence of resistivity, these modes occur well below the ideal limit. Their growth rate scaling with resistivity is similar to tearing modes. At low resistivity, the modes couple to resistive interchanges, which are unstable in most stellarators. Two fluid simulations with M3D show that resistive modes can be stabilized by diamagnetic drift. The two fluid computations are done with a realistic value of the Hall parameter, the ratio of ion skin depth to major radius. Hybrid gyrokinetic simulations with energetic particles indicate that global shear Alfven TAE - like modes can be destabilized in stellarators. Computations in a two-period compact stellarator obtained a predominantly n=1 toroidal mode with the expected TAE frequency. It is found that TAE modes are more stable in the two-period compact stellarator that in a tokamak with the same q and pressure profiles. M3D combines a two dimensional unstructured mesh with finite element discretization in poloidal planes, and fourth order finite differencing in the toroidal direction. (author)

[Conservative treatment using plasma rich in growth factors (PRGF) for injury to the ligamentous complex of the ankle].

Science.gov (United States)

Frei, R; Biosca, F E; Handl, M; Trc, T

2008-02-01

The authors describe the therapeutic utilization of separated/isolated autologous growth factors in semiconservative treatment of type III injury to the ankle ligamentous complex. Between October 2004 and March 2005 a group of 11 patients, two women and nine men, aged 18 to 41 (average, 25.09) years with acute injury to the lateral ligamentous complex of the ankle were treated by plasma rich in growth factors (PRGF) infiltration. On functional radiographic examination, the post-traumatic lateral opening of the tibiotalar intraarticular space was 17.45 degrees (range, 12.0-30.0; s = 5.68). The injured patients were clinically examined and standard forced inversion radiographs were made using topical anesthesia. Autologous PRGF activated with calcium chloride was used to infiltrate the injured tissues. The treatment was followed by immobilization of the joint and its subsequent rehabilitation. Clinical examination of injured tissues was carried out at 4 and 6 weeks of follow-up, using stability assessment tests and functional radiography of the ankle. Physical therapy included standard procedures, but faster regeneration of the soft tissues allowed for more exercises. The average time of healing was 5.18 weeks. Five patients showed no signs of instability at 4 weeks after therapy and could return to their previous sports activities. One patient had lateral ankle instability at 5 weeks and therefore the therapy continued with prolonged immobilization and then rehabilitation at a slower pace. The average lateral opening of the tibiotalar intra-articular space at 4 or 6 follow-up weeks was 4.73 degrees (range, 3.0 - 7.0; s = 1.19). At 6 weeks after therapy, 90.9% of the patients resumed their full sports activities. Ankle distortion with swelling, hematoma and pain, but with no radiographic findings of ligament lesions, is usually treated conservatively by ankle immobilization and early rehabilitation. When an injury to the fibular ankle ligaments occurs (i.e., opening

ON THE SATURATION OF THE MAGNETOROTATIONAL INSTABILITY VIA PARASITIC MODES

International Nuclear Information System (INIS)

Pessah, Martin E.; Goodman, Jeremy

2009-01-01

We investigate the stability of incompressible, exact, non-ideal magnetorotational (MRI) modes against parasitic instabilities. Both Kelvin-Helmholtz and tearing-mode parasitic instabilities may occur in the dissipative regimes accessible to current numerical simulations. We suppose that a primary MRI mode saturates at an amplitude such that its fastest parasite has a growth rate comparable to its own. The predicted alpha parameter then depends critically on whether the fastest primary and parasitic modes fit within the computational domain and whether non-axisymmetric parasitic modes are allowed. Hence, even simulations that resolve viscous and resistive scales may not saturate properly unless the numerical domain is large enough to allow the free evolution of both MRI and parasitic modes. To minimally satisfy these requirements in simulations with vertical background fields, the vertical extent of the domain should accommodate the fastest growing MRI mode while the radial and azimuthal extents must be twice as large. The fastest parasites have horizontal wavelengths roughly twice as long as the vertical wavelength of the primary.

C-di-GMP regulates Pseudomonas aeruginosa stress response to tellurite during both planktonic and biofilm modes of growth

DEFF Research Database (Denmark)

Chua, Song Lin; Sivakumar, Krishnakumar; Rybtke, Morten Levin

2015-01-01

tellurite (TeO3(2-)) exposure induced the intracellular content of the secondary messenger cyclic di-GMP (c-di-GMP) of Pseudomonas aeruginosa. Two diguanylate cyclases (DGCs), SadC and SiaD, were responsible for the increased intracellular content of c-di-GMP. Enhanced c-di-GMP levels by TeO3(2-) further...... increased P. aeruginosa biofilm formation and resistance to TeO3(2-). P. aeruginosa ΔsadCΔsiaD and PAO1/p(lac)-yhjH mutants with low intracellular c-di-GMP content were more sensitive to TeO3(2-) exposure and had low relative fitness compared to the wild-type PAO1 planktonic and biofilm cultures exposed...... to TeO3(2-). Our study provided evidence that c-di-GMP level can play an important role in mediating stress response in microbial communities during both planktonic and biofilm modes of growth....

GaN Power Stage for Switch-mode Audio Amplification

DEFF Research Database (Denmark)

Ploug, Rasmus Overgaard; Knott, Arnold; Poulsen, Søren Bang

2015-01-01

Gallium Nitride (GaN) based power transistors are gaining more and more attention since the introduction of the enhancement mode eGaN Field Effect Transistor (FET) which makes an adaptation from Metal-Oxide Semiconductor (MOSFET) to eGaN based technology less complex than by using depletion mode Ga......N FETs. This project seeks to investigate the possibilities of using eGaN FETs as the power switching device in a full bridge power stage intended for switch mode audio amplification. A 50 W 1 MHz power stage was built and provided promising audio performance. Future work includes optimization of dead...

Multiplexing of spatial modes in the mid-IR region

Science.gov (United States)

Gailele, Lucas; Maweza, Loyiso; Dudley, Angela; Ndagano, Bienvenu; Rosales-Guzman, Carmelo; Forbes, Andrew

2017-02-01

Traditional optical communication systems optimize multiplexing in polarization and wavelength both trans- mitted in fiber and free-space to attain high bandwidth data communication. Yet despite these technologies, we are expected to reach a bandwidth ceiling in the near future. Communications using orbital angular momentum (OAM) carrying modes offers infinite dimensional states, providing means to increase link capacity by multiplexing spatially overlapping modes in both the azimuthal and radial degrees of freedom. OAM modes are multiplexed and de-multiplexed by the use of spatial light modulators (SLM). Implementation of complex amplitude modulation is employed on laser beams phase and amplitude to generate Laguerre-Gaussian (LG) modes. Modal decomposition is employed to detect these modes due to their orthogonality as they propagate in space. We demonstrate data transfer by sending images as a proof-of concept in a lab-based scheme. We demonstrate the creation and detection of OAM modes in the mid-IR region as a precursor to a mid-IR free-space communication link.

RHEED transmission mode and pole figures thin film and nanostructure texture analysis

CERN Document Server

Wang, Gwo-Ching

2014-01-01

This unique book covers the fundamental principle of electron diffraction, basic instrumentation of RHEED, definitions of textures in thin films and nanostructures, mechanisms and control of texture formation, and examples of RHEED transmission mode measurements of texture and texture evolution of thin films and nanostructures. Also presented is a new application of RHEED in the transmission mode called RHEED pole figure technique that can be used to monitor the texture evolution in thin film growth and nanostructures and is not limited to single crystal epitaxial film growth. Details of the construction of RHEED pole figures and the interpretation of observed pole figures are presented.  Materials covered include metals, semiconductors, and thin insulators. This book also: Presents a new application of RHEED in the transmission mode Introduces a variety of textures from metals, semiconductors, compound semiconductors, and their characteristics in RHEED pole figures Provides examples of RHEED measurements o...

Is anatomic complexity associated with renal tumor growth kinetics under active surveillance?

Science.gov (United States)

Mehrazin, Reza; Smaldone, Marc C; Egleston, Brian; Tomaszewski, Jeffrey J; Concodora, Charles W; Ito, Timothy K; Abbosh, Philip H; Chen, David Y T; Kutikov, Alexander; Uzzo, Robert G

2015-04-01

Linear growth rate (LGR) is the most commonly employed trigger for definitive intervention in patients with renal masses managed with an initial period of active surveillance (AS). Using our institutional cohort, we explored the association between tumor anatomic complexity at presentation and LGR in patients managed with AS. Enhancing renal masses managed expectantly for at least 6 months were included for analysis. The association between Nephrometry Score and LGR was assessed using generalized estimating equations, adjusting for the age, Charlson score, race, sex, and initial tumor size. Overall, 346 patients (401 masses) met the inclusion criteria (18% ≥ cT1b), with a median follow-up of 37 months (range: 6-169). Of these, 44% patients showed progression to definitive intervention with a median duration of 27 months (range: 6-130). On comparing patients managed expectantly to those requiring intervention, no difference was seen in median tumor size at presentation (2.2 vs. 2.2 cm), whereas significant differences in median age (74 vs. 65 y, P anatomic tumor complexity at presentation and renal masses of LGR of clinical stage 1 under AS may afford a clinically useful cue to tailor individual patient radiographic surveillance schedules and warrants further evaluation. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of multi-nutrient complex fertilizers on growth and tuber yield of very early potato (Solanum tuberosum L. cultivars

Directory of Open Access Journals (Sweden)

Wanda Wadas

2013-10-01

Full Text Available The aim of the study was to compare the effect of multi-nutrient complex fertilizers (HydroComplex, Nitrophoska Blue Special and Viking 13 from the nitrophoska group, and Polimag S from the amophoska group and single-nutrient fertilizers on the growth and tuber yield of very early potato cultivars (‘Aster’, ‘Fresco’, ‘Gloria’. The field experiment was carried out on podzolic soil in mid-eastern Poland during 2005–2007. The study showed a greater beneficial effect of HydroComplex and Nitrophoska Blue Special on the growth of very early potato cultivars than that of Viking 13 and Polimag S. The application of HydroComplex and Nitrophoska Blue Special resulted in greater above-ground plant biomass and assimilation leaf area compared with single-nutrient fertilizers; the leaf area index (LAI was higher by 0.28 and 0.32, respectively. The differences were smaller and not statistically confirmed with the use of Polimag S and Viking 13. When the multi-nutrient complex fertilizers were applied, leaf weight ratio (LWR, leaf area ratio (LAR and specific leaf area (SLA were similar to the single-nutrient fertilizers. Of the multi-nutrient complex fertilizers, only Nitrophoska Blue Special resulted in higher tuber yield, on average by 2.40 t × ha-1, compared with the single-nutrient fertilizers. The studied cultivars showed a similar response to applied fertilizers. LAI for ‘Gloria’ was higher than for ‘Aster’ and ‘Fresco’, with smaller LAR found in ‘Gloria’. LWR for ‘Fresco’ was smaller than for ‘Aster’ and ‘Gloria’, with higher SLA found in ‘Fresco’. The tuber yield of ‘Aster” (24.04 t × ha-1 was higher on average by 3 t × ha-1 than for ‘Fresco’ and ‘Gloria’.

Effect of Alfvén waves on the growth rate of the electron-cyclotron maser emission

Energy Technology Data Exchange (ETDEWEB)

Wu, D. J., E-mail: djwu@pmo.ac.cn [Purple Mountain Observatory, CAS, Nanjing 210008 (China)

2014-06-15

By using the non-relativistic approximation for the calculation of growth rates, but taking account of the weakly relativistic modification for the electron-cyclotron resonance condition, it is shown that the effect of Alfvén waves (AWs) on the electron-cyclotron maser emission leads to the significant increase of the O-mode growth rate, but has little effect on the X-mode growth rate. We propose that this is because the O-mode wave has the field-aligned polarization sense in the same as the field-aligned oscillatory current, which is created by the field-aligned oscillatory motion of the energetic electrons caused via the presence of AWs. It is this field-aligned oscillatory current that contributes a novel growth rate to the O-mode wave but has little effect on the X-mode wave.

Working in the Field of Complex Psychological Trauma: A Framework for Personal and Professional Growth, Training, and Supervision.

Science.gov (United States)

Coleman, Anne Marie; Chouliara, Zoë; Currie, Kay

2018-03-01

The aim of this article is to explore the positive and negative impacts of working therapeutically in complex psychological trauma (CPT), particularly the field of gender-based violence (GBV) and childhood sexual abuse (CSA), from the clinicians' perspective. The focus was on the prospect of positive gains and growth for therapists. Twenty-one clinicians ( n = 21; counselors/psychotherapists and psychologists) from National Health Service (NHS) specialist trauma services, a community mental health team, and specialist sexual assault counseling organization participated. Interpretative phenomenological analysis (IPA) was utilized to conduct single one-off interviews and analysis. Six themes were identified: Called to the work; Connection, Separation, and Oneness; Into and out of the darkness; Chaos into meaning; Reparation not repetition; and Expansion and growth. The first "Therapist Led Framework of Growth in Trauma Work" is presented. Vicarious posttraumatic growth (VPTG) was a key finding, with CPT therapists experiencing a "challenge/benefit/change" growth process. Adoption of actively relational strategies to enhance clinicians' growth process through trauma work is being proposed. The benefits of conceptualizing both the positive and negative impacts of such work for supervision, training, shaping the formal curricula, service management, and continuing professional development (CPD) are being discussed. The need for good practice guidelines on self-care internationally is highlighted.

Physics of resistive wall modes

International Nuclear Information System (INIS)

Igochine, V.

2012-01-01

The advanced tokamak regime is a promising candidate for steady-state tokamak operation which is desirable for a fusion reactor. This regime is characterized by a high bootstrap current fraction and a flat or reversed safety factor profile, which leads to operation close to the pressure limit. At this limit, an external kink mode becomes unstable. This external kink is converted into the slowly growing resistive wall mode (RWM) by the presence of a conducting wall. Reduction of the growth rate allows one to act on the mode and to stabilize it. There are two main factors which determine the stability of the RWM. The first factor comes from external magnetic perturbations (error fields, resistive wall, feedback coils, etc). This part of RWM physics is the same for tokamaks and reversed field pinch configurations. The physics of this interaction is relatively well understood and based on classical electrodynamics. The second ingredient of RWM physics is the interaction of the mode with plasma flow and fast particles. These interactions are particularly important for tokamaks, which have higher plasma flow and stronger trapped particle effects. The influence of the fast particles will also be increasingly more important in ITER and DEMO which will have a large fraction of fusion born alpha particles. These interactions have kinetic origins which make the computations challenging since not only particles influence the mode, but also the mode acts on the particles. Correct prediction of the ‘plasma–RWM’ interaction is an important ingredient which has to be combined with external field's influence (resistive wall, error fields and feedback) to make reliable predictions for RWM behaviour in tokamaks. All these issues are reviewed in this paper. (special topic)

Wave mode instabilities in a two-stream free-electron laser with a background plasma

International Nuclear Information System (INIS)

Nadrifard, Shabnam; Maraghechi, B; Mohsenpour, T

2013-01-01

A theory is presented for a two-stream free-electron laser (FEL) with a background plasma. A dispersion relation (DR) for the unstable couplings of wave modes is derived using fluid formulation. This DR is solved numerically to find the unstable modes and their growth rate. The effect of the velocity difference of the two electron beams as well as the background plasma on the FEL resonance and the two-stream instability is studied. It is shown that their separate as well as combined effects can increase the growth rates. (paper)

On the structure of the two-stream instability–complex G-Hamiltonian structure and Krein collisions between positive- and negative-action modes

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ruili; Liu, Jian; Xiao, Jianyuan [Department of Modern Physics and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Key Laboratory of Geospace Environment, CAS, Hefei, Anhui 230026 (China); Qin, Hong, E-mail: hongqin@princeton.edu [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Department of Modern Physics and School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Davidson, Ronald C. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2016-07-15

The two-stream instability is probably the most important elementary example of collective instabilities in plasma physics and beam-plasma systems. For a warm plasma with two charged particle species, the instability diagram of the two-stream instability based on a 1D warm-fluid model exhibits an interesting band structure that has not been explained. We show that the band structure for this instability is the consequence of the Hamiltonian nature of the warm two-fluid system. Interestingly, the Hamiltonian nature manifests as a complex G-Hamiltonian structure in wave-number space, which directly determines the instability diagram. Specifically, it is shown that the boundaries between the stable and unstable regions are locations for Krein collisions between eigenmodes with different Krein signatures. In terms of physics, this rigorously implies that the system is destabilized when a positive-action mode resonates with a negative-action mode, and that this is the only mechanism by which the system can be destabilized. It is anticipated that this physical mechanism of destabilization is valid for other collective instabilities in conservative systems in plasma physics, accelerator physics, and fluid dynamics systems, which admit infinite-dimensional Hamiltonian structures.

The impact of pedestal turbulence and electron inertia on edge-localized-mode crashes

Energy Technology Data Exchange (ETDEWEB)

Xi, P. W. [FSC and State Key Lab of Nuclear Physics and Technology, Department of Physics, Peking University, Beijing 100871 (China); Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Xu, X. Q. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon (Korea, Republic of); Center for Astrophysics and Space Sciences and Department of Physics, University of California San Diego, La Jolla, California 92093-0429 (United States)

2014-05-15

We demonstrate that the occurrence of Edge-Localized-Modes (ELM) crashes does not depend only on the linear peeling-ballooning threshold, but also relies on nonlinear processes. Wave-wave interaction constrains the growth time of a mode, thus inducing a shift in the criterion for triggering an ELM crash. An ELM crash requires the P-B growth rate to exceed a critical value γ>γ{sub c}, where γ{sub c} is set by 1/τ{sup ¯}{sub c}, and τ{sup ¯}{sub c} is the averaged mode phase coherence time. For 0<γ<γ{sub c}, P-B turbulence develops but drives enhanced turbulent transport. We also show that electron inertia dramatically changes the instability threshold when density is low. However, P-B turbulence alone cannot generate enough current transport to allow fast reconnection during an ELM crash.

AFM study of growth of Bi2Sr2-xLaxCuO6 thin films

International Nuclear Information System (INIS)

Haitao Yang; Hongjie Tao; Yingzi Zhang; Duogui Yang; Lin Li; Zhongxian Zhao

1997-01-01

c-axis-oriented Bi 2 Sr 1.6 La 0.4 CuO 6 thin films deposited on flat planes of (100)SrTiO 3 , (100)LaAlO 3 and (100)MgO substrates and vicinal planes (off-angle ∼ 6 deg.) of SrTiO 3 substrates by RF magnetron sputtering were studied by atomic force microscopy (AFM). T c of these films reached 29 K. Film thickness ranged from 15 nm to 600 nm. Two typical growth modes have been observed. AFM images of thin films on flat planes of substrates showed a terraced-island growth mode. By contrast, Bi-2201 thin films on vicinal planes of substrates showed a step-flow growth mode. The growth unit is a half-unit-cell in the c-axis for both growth modes. No example of spiral growth, which was thought to be the typical structure of YBCO thin films, was found in either of these kinds of thin films. (author)

Experimental investigation of different regimes of mode-locking in a high repetition rate passively mode-locked semiconductor quantum-dot laser.

Science.gov (United States)

Kéfélian, Fabien; O'Donoghue, Shane; Todaro, Maria Teresa; McInerney, John; Huyet, Guillaume

2009-04-13

We report experimental investigations on a two-section 16-GHz repetition rate InAs/GaAs quantum dot passively mode-locked laser. Near the threshold current, pseudo-periodic Q-switching with complex dynamics is exhibited. Mode-locking operation regimes characterized by different repetition rates and timing jitter levels are encountered up to twice the threshold current. Evolution of the RF spectrum and optical spectrum with current is compared. The different mode-locked regimes are shown to be associated with different spectral and temporal shapes, ranging from 1.3 to 6 ps. This point is discussed by introducing the existence of two different supermodes. Repetition rate evolution and timing jitter increase is attributed to the coupling between the dominant and the secondary supermodes.

Two-mode PLC-based mode multi/demultiplexer for mode and wavelength division multiplexed transmission.

Science.gov (United States)

Hanzawa, Nobutomo; Saitoh, Kuimasa; Sakamoto, Taiji; Matsui, Takashi; Tsujikawa, Kyozo; Koshiba, Masanori; Yamamoto, Fumihiko

2013-11-04

We proposed a PLC-based mode multi/demultiplexer (MUX/DEMUX) with an asymmetric parallel waveguide for mode division multiplexed (MDM) transmission. The mode MUX/DEMUX including a mode conversion function with an asymmetric parallel waveguide can be realized by matching the effective indices of the LP(01) and LP(11) modes of two waveguides. We report the design of a mode MUX/DEMUX that can support C-band WDM-MDM transmission. The fabricated mode MUX/DEMUX realized a low insertion loss of less than 1.3 dB and high a mode extinction ratio that exceeded 15 dB. We used the fabricated mode MUX/DEMUX to achieve a successful 2 mode x 4 wavelength x 10 Gbps transmission over a 9 km two-mode fiber with a penalty of less than 1 dB.

Stability analysis of resistive MHD modes via a new numerical matching technique

International Nuclear Information System (INIS)

Furukawa, M.; Tokuda, S.; Zheng, L.-J.

2009-01-01

1 shows the growth rate of m/n = 2/1 tearing mode as a function of the width of the 'inner region' Δr. The growth rate is normalized by its value without the numerical matching. We see that the growth rate is calculated in a sufficient accuracy even for Δr = 0.1. In addition, the smaller resistivity η allows thinner inner region. (author)

Elevator mode convection in flows with strong magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Liu, Li; Zikanov, Oleg, E-mail: zikanov@umich.edu [Department of Mechanical Engineering, University of Michigan-Dearborn, 48128-1491 Michigan (United States)

2015-04-15

Instability modes in the form of axially uniform vertical jets, also called “elevator modes,” are known to be the solutions of thermal convection problems for vertically unbounded systems. Typically, their relevance to the actual flow state is limited by three-dimensional breakdown caused by rapid growth of secondary instabilities. We consider a flow of a liquid metal in a vertical duct with a heated wall and strong transverse magnetic field and find elevator modes that are stable and, thus, not just relevant, but a dominant feature of the flow. We then explore the hypothesis suggested by recent experimental data that an analogous instability to modes of slow axial variation develops in finite-length ducts, where it causes large-amplitude fluctuations of temperature. The implications for liquid metal blankets for tokamak fusion reactors that potentially invalidate some of the currently pursued design concepts are discussed.

Nondestructive evaluation of helicopter rotor blades using guided Lamb modes.

Science.gov (United States)

Chakrapani, Sunil Kishore; Barnard, Daniel; Dayal, Vinay

2014-03-01

This paper presents an application for turning and direct modes in a complex composite laminate structure. The propagation and interaction of turning modes and fundamental Lamb modes are investigated in the skin, spar and web sections of a helicopter rotor blade. Finite element models were used to understand the various mode conversions at geometric discontinuities such as web-spar joints. Experimental investigation was carried out with the help of air coupled ultrasonic transducers. The turning and direct modes were confirmed with the help of particle displacements and velocities. Experimental B-Scans were performed on damaged and undamaged samples for qualitative and quantitative assessment of the structure. A strong correlation between the numerical and experimental results was observed and reported. Copyright © 2013 Elsevier B.V. All rights reserved.

A Microplate Growth Inhibition Assay for Screening Bacteriocins against Listeria monocytogenes to Differentiate Their Mode-of-Action

Directory of Open Access Journals (Sweden)

Paul Priyesh Vijayakumar

2015-06-01

Full Text Available Lactic acid bacteria (LAB have historically been used in food fermentations to preserve foods and are generally-recognized-as-safe (GRAS by the FDA for use as food ingredients. In addition to lactic acid; some strains also produce bacteriocins that have been proposed for use as food preservatives. In this study we examined the inhibition of Listeria monocytogenes 39-2 by neutralized and non-neutralized bacteriocin preparations (Bac+ preps produced by Lactobacillus curvatus FS47; Lb. curvatus Beef3; Pediococcus acidilactici Bac3; Lactococcus lactis FLS1; Enterococcus faecium FS56-1; and Enterococcus thailandicus FS92. Activity differences between non-neutralized and neutralized Bac+ preps in agar spot assays could not readily be attributed to acid because a bacteriocin-negative control strain was not inhibitory to Listeria in these assays. When neutralized and non-neutralized Bac+ preps were used in microplate growth inhibition assays against L. monocytogenes 39-2 we observed some differences attributed to acid inhibition. A microplate growth inhibition assay was used to compare inhibitory reactions of wild-type and bacteriocin-resistant variants of L. monocytogenes to differentiate bacteriocins with different modes-of-action (MOA whereby curvaticins FS47 and Beef3, and pediocin Bac3 were categorized to be in MOA1; enterocins FS92 and FS56-1 in MOA2; and lacticin FLS1 in MOA3. The microplate bacteriocin MOA assay establishes a platform to evaluate the best combination of bacteriocin preparations for use in food applications as biopreservatives against L. monocytogenes.

A Microplate Growth Inhibition Assay for Screening Bacteriocins against Listeria monocytogenes to Differentiate Their Mode-of-Action.

Science.gov (United States)

Vijayakumar, Paul Priyesh; Muriana, Peter M

2015-06-11

Lactic acid bacteria (LAB) have historically been used in food fermentations to preserve foods and are generally-recognized-as-safe (GRAS) by the FDA for use as food ingredients. In addition to lactic acid; some strains also produce bacteriocins that have been proposed for use as food preservatives. In this study we examined the inhibition of Listeria monocytogenes 39-2 by neutralized and non-neutralized bacteriocin preparations (Bac+ preps) produced by Lactobacillus curvatus FS47; Lb. curvatus Beef3; Pediococcus acidilactici Bac3; Lactococcus lactis FLS1; Enterococcus faecium FS56-1; and Enterococcus thailandicus FS92. Activity differences between non-neutralized and neutralized Bac+ preps in agar spot assays could not readily be attributed to acid because a bacteriocin-negative control strain was not inhibitory to Listeria in these assays. When neutralized and non-neutralized Bac+ preps were used in microplate growth inhibition assays against L. monocytogenes 39-2 we observed some differences attributed to acid inhibition. A microplate growth inhibition assay was used to compare inhibitory reactions of wild-type and bacteriocin-resistant variants of L. monocytogenes to differentiate bacteriocins with different modes-of-action (MOA) whereby curvaticins FS47 and Beef3, and pediocin Bac3 were categorized to be in MOA1; enterocins FS92 and FS56-1 in MOA2; and lacticin FLS1 in MOA3. The microplate bacteriocin MOA assay establishes a platform to evaluate the best combination of bacteriocin preparations for use in food applications as biopreservatives against L. monocytogenes.

Charge Inversion of Phospholipids by Dimetal Complexes for Positive Ion-Mode Electrospray Ionization Mass Spectrometry Analysis

DEFF Research Database (Denmark)

Svane, Simon; Gorshkov, Vladimir; Kjeldsen, Frank

2015-01-01

charges per phosphate group. Three different phosphoinositide phosphates (mono-, di-, and triphosphorylated inositides), a phosphatidic acid, a phosphatidylcholine, a phosphatidylethanolamine, and a phosphatidylglycerol were investigated. The intensities obtained in positive ion-mode of phosphoinositide...... phosphates and phosphatidic acid bound to {LGa2}(5+) were between 2.5- and 116-fold higher than that of the unmodified lipids in the negative ion-mode. Native phosphoinositide ions yielded upon CID in the negative ion-mode predominantly product ions due to losses of H3PO4, PO3(-) and H2O. In comparison, CID...

Stabilization of kinetic internal kink mode by ion diamagnetic effects

International Nuclear Information System (INIS)

Naitou, H.; Kuramoto, T.; Kobayashi, T.; Yagi, M.; Tokuda, S.; Matsumoto, T.

2000-04-01

Ion diamagnetic effects on the m=1 (poloidal mode number) and n=1 (toroidal mode number) kinetic internal kink mode are studied numerically by the three-field gyro-reduced-MHD code in the cylindrical coordinates, GRM3F-CY. In the derivation of the gryo-reduced-MHD model including the ion diamagnetic effects, finite gyroradius effects of ions are added to the gyrokinetic Poisson equation (quasi-neutral condition) and the convection term of the conservation law of the ion density. It is found that the long wavelength approximation, ksub(perpendicular) ρ ti ti is the thermal ion gyroradius, fails to reproduce the correct dispersion relation; the formulation valid even for ksub(perpendicular) ρ ti >> 1 is necessary. The results of numerical calculation coincide with the theory for |ω *e |+|ω *i | 0 , where the growth rate reduces as the density gradient increases. Here ω *e and ω *i are electron and ion diamagnetic angular frequencies estimated at the rational surface of q=1 (q is a safety factor), respectively, and γ 0 is the growth rate for the uniform density. Very weak instability, however, is observed for |ω *e |+|ω *i | 0 , where the theory predicts the complete stabilization. This residual instability appears since the region with the density gradient is limited in the radial direction and the stabilization by the outgoing drift-wave like mode becomes incomplete. (author)

Local effect of equilibrium current on tearing mode stability

International Nuclear Information System (INIS)

Cozzani, F.

1985-12-01

The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in tokamaks is investigated analytically. The plasma response inside the tearing layer is derived from fluid theory and the local equilibrium current is shown to couple to the mode dynamics through its gradient, which is proportional to the local electron temperature gradient under the approximations used in the analysis. The relevant eigenmode equations, expressing Ampere's law and the plasma quasineutrality condition, respectively, are suitably combined in a single integral equation, from which a variational principle is formulated to derive the mode dispersion relations for several cases of interest. The local equilibrium current is treated as a small perturbation of the known results for the m greater than or equal to 2 and the m = 1 tearing modes in the collisional regime, and the m greater than or equal to 2 tearing mode in the semicollisional regime; its effect is found to enhance stabilization for the m greater than or equal to 2 drift-tearing mode in the collisional regime, whereas the m = 1 growth rate is very slightly increased and the stabilizing effect of the parallel thermal conduction on the m greater than or equal to 2 mode in the semicollisional regime is slightly reduced

Chaos in a complex plasma

International Nuclear Information System (INIS)

Sheridan, T.E.

2005-01-01

Chaotic dynamics is observed experimentally in a complex (dusty) plasma of three particles. A low-frequency sinusoidal modulation of the plasma density excites both the center-of-mass and breathing modes. Low-dimensional chaos is seen for a 1:2 resonance between these modes. A strange attractor with a dimension of 2.48±0.05 is observed. The largest Lyapunov exponent is positive

Phosphorus-hydrogen complexes in LEC-grown InP

International Nuclear Information System (INIS)

Ulrici, W.; Kwasniewski, A.; Czupalla, M.; Neubert, M.

2005-01-01

In LEC-grown InP, about 30 sharp vibrational absorption lines are measured in the frequency region 2200 to 2350 cm -1 . All these lines are due to phosphorus-hydrogen stretching modes. Experiments on InP containing both hydrogen and deuterium finally proved that the line at 2202.4 cm -1 is due to a single hydrogen atom bonded to P in an indium vacancy (V In ) and that the line at 2315.6 cm -1 is due to the complex of four P-H bonds in an V In . In InP:H:D, this V In H 4 complex gives rise to six vibrational lines in the region of P-H modes and six lines in the region of P-D modes because of the five different types of V In H n D m complexes. The measured frequencies of these 12 lines are in excellent agreement with those obtained from ab initio calculations reported in the literature. Additional P-H complexes are discussed. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Influence of mode-beating pulse on laser-induced plasma

Science.gov (United States)

Nishihara, M.; Freund, J. B.; Glumac, N. G.; Elliott, G. S.

2018-04-01

This paper addresses the influence of mode-beating pulse on laser-induced plasma. The second harmonic of a Nd:YAG laser, operated either with the single mode or multimode, was used for non-resonant optical breakdown, and subsequent plasma development was visualized using a streak imaging system. The single mode lasing leads to a stable breakdown location and smooth envelopment of the plasma boundary, while the multimode lasing, with the dominant mode-beating frequency of 500-800 MHz, leads to fluctuations in the breakdown location, a globally modulated plasma surface, and growth of local microstructures at the plasma boundary. The distribution of the local inhomogeneity was measured from the elastic scattering signals on the streak image. The distance between the local structures agreed with the expected wavelength of hydrodynamic instability development due to the interference between the surface excited wave and transmitted wave. A numerical simulation, however, indicates that the local microstructure could also be directly generated at the peaks of the higher harmonic components if the multimode pulse contains up to the eighth harmonic of the fundamental cavity mode.

Nonlinear growth of the quasi-interchange instability

International Nuclear Information System (INIS)

Waelbroeck, F.L.

1988-07-01

In this paper nonlinear effects on the growth of a pressure-driven, interchange-like mode are investigated. This mode is thought to be responsible for the sawtooth crashes observed in JET and successfully accounts for most of their features. The analysis presented here differs from previous bifurcation calculations by the inclusion of toroidal coupling effects. Toroidal curvature, which is important for pressure-driven modes, destroys the helical symmetry which is typical of kink-like instabilities. 14 refs., 3 figs

Resistive ballooning modes in W7-AS and W7-X

International Nuclear Information System (INIS)

Kaiser, R.

1993-01-01

'Critical' pressure gradients due to resistive ballooning modes and their growth rates were computed for the W7-AS stellarator and for a HELIAS configuration with W7-X parameters, and the two configurations were compared. The results are based on the evaluation of a fourth order magnetic differential equation along closed magnetic field lines. The numerical procedure applying a variational approach uses the 'Garching resistive ballooning code', GARBO, which was originally developed for the stability analysis of axisymmetric plasmas. Concerning purely growing modes, this analysis shows that the favourable stability properties of W7-X, already optimized with respect to ideal ballooning modes, persist in the resistive regime: the destabilizing effect of resistivity is largely compensated by the stabilizing contribution of plasma compression. As a consequence, the ideal β limit continues only moderately shifted in the resistive case and likewise ideal ballooning stable equilibria (up to β 0 ≅ 5%) do not become resistively unstable. The situation is different for W7-AS. Greater resistive effects (in comparison with W7-X) are found in a configuration that is already ideally much more unstable. A basic feature in resistive calculations is the occurrence of overstable modes. These modes no longer show a stability threshold and, for realistic values of pressure and resistivity, linear instability is obtained for W7-AS as well as for W7-X, with growth rates and oscillation frequencies in the kilo-Hertz range. (author). 29 refs, 13 figs

Growth Kinetics and Size Distribution Dynamics of Viscous Secondary Organic Aerosol

Energy Technology Data Exchange (ETDEWEB)

Zaveri, Rahul A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Shilling, John E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Zelenyuk, Alla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Liu, Jiumeng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Bell, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. of Atmospheric Chemistry; D’Ambro, Emma L. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences and Dept. of Chemistry; Gaston, Cassandra J. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences; Univ. of Miami, Miami, FL (United States). Rosenstiel School of Marine and Atmospheric Science; Thornton, Joel A. [Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences and Dept. of Chemistry; Laskin, Alexander [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Purdue Univ., West Lafayette, IN (United States). Dept. of Chemistry; Lin, Peng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL); Purdue Univ., West Lafayette, IN (United States). Dept. of Chemistry; Wilson, Jacqueline [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Div.; Easter, Richard C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC); Wang, Jian [Brookhaven National Lab. (BNL), Upton, NY (United States). Environmental & Climate Sciences Dept.; Bertram, Allan K. [Univ. of British Columbia, Vancouver, BC (Canada). Dept. of Chemistry; Martin, Scot T. [Harvard Univ., Cambridge, MA (United States). School of Engineering and Applied Sciences (SEAS) and Dept. of Earth and Planetary Sciences; Seinfeld, John H. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Div. of Chemistry and Chemical Engineering and Div. of Engineering and Applied Science; Worsnop, Douglas R. [Aerodyne Research, Billerica, MA (United States). Center for Aerosol and Cloud Chemistry

2017-12-15

Low bulk diffusivity inside viscous semisolid atmospheric secondary organic aerosol (SOA) can prolong equilibration time scale, but its broader impacts on aerosol growth and size distribution dynamics are poorly understood. In this article, we present quantitative insights into the effects of bulk diffusivity on the growth and evaporation kinetics of SOA formed under dry conditions from photooxidation of isoprene in the presence of a bimodal aerosol consisting of Aitken (ammonium sulfate) and accumulation (isoprene or α-pinene SOA) mode particles. Aerosol composition measurements and evaporation kinetics indicate that isoprene SOA is composed of several semivolatile organic compounds (SVOCs), with some reversibly reacting to form oligomers. Model analysis shows that liquid-like bulk diffusivities can be used to fit the observed evaporation kinetics of accumulation mode particles but fail to explain the growth kinetics of bimodal aerosol by significantly under-predicting the evolution of the Aitken mode. In contrast, the semisolid scenario successfully reproduces both evaporation and growth kinetics, with the interpretation that hindered partitioning of SVOCs into large viscous particles effectively promotes the growth of smaller particles that have shorter diffusion time scales. This effect has important implications for the growth of atmospheric ultrafine particles to climatically active sizes.

Weakly nonlinear incompressible Rayleigh-Taylor instability growth at cylindrically convergent interfaces

International Nuclear Information System (INIS)

Wang, L. F.; He, X. T.; Wu, J. F.; Zhang, W. Y.; Ye, W. H.

2013-01-01

A weakly nonlinear (WN) model has been developed for the incompressible Rayleigh-Taylor instability (RTI) in cylindrical geometry. The transition from linear to nonlinear growth is analytically investigated via a third-order solutions for the cylindrical RTI initiated by a single-mode velocity perturbation. The third-order solutions can depict the early stage of the interface asymmetry due to the bubble-spike formation, as well as the saturation of the linear (exponential) growth of the fundamental mode. The WN results in planar RTI [Wang et al., Phys. Plasmas 19, 112706 (2012)] are recovered in the limit of high-mode number perturbations. The difference between the WN growth of the RTI in cylindrical geometry and in planar geometry is discussed. It is found that the interface of the inward (outward) development spike/bubble is extruded (stretched) by the additional inertial force in cylindrical geometry compared with that in planar geometry. For interfaces with small density ratios, the inward growth bubble can grow fast than the outward growth spike in cylindrical RTI. Moreover, a reduced formula is proposed to describe the WN growth of the RTI in cylindrical geometry with an acceptable precision, especially for small-amplitude perturbations. Using the reduced formula, the nonlinear saturation amplitude of the fundamental mode and the phases of the Fourier harmonics are studied. Thus, it should be included in applications where converging geometry effects play an important role, such as the supernova explosions and inertial confinement fusion implosions.

Acceleration of FDTD mode solver by high-performance computing techniques.

Science.gov (United States)

Han, Lin; Xi, Yanping; Huang, Wei-Ping

2010-06-21

A two-dimensional (2D) compact finite-difference time-domain (FDTD) mode solver is developed based on wave equation formalism in combination with the matrix pencil method (MPM). The method is validated for calculation of both real guided and complex leaky modes of typical optical waveguides against the bench-mark finite-difference (FD) eigen mode solver. By taking advantage of the inherent parallel nature of the FDTD algorithm, the mode solver is implemented on graphics processing units (GPUs) using the compute unified device architecture (CUDA). It is demonstrated that the high-performance computing technique leads to significant acceleration of the FDTD mode solver with more than 30 times improvement in computational efficiency in comparison with the conventional FDTD mode solver running on CPU of a standard desktop computer. The computational efficiency of the accelerated FDTD method is in the same order of magnitude of the standard finite-difference eigen mode solver and yet require much less memory (e.g., less than 10%). Therefore, the new method may serve as an efficient, accurate and robust tool for mode calculation of optical waveguides even when the conventional eigen value mode solvers are no longer applicable due to memory limitation.

Kinetics of slow domain growth in complex systems

International Nuclear Information System (INIS)

Lindgard, P.-A.; Castan, T.

1989-01-01

The domain growth after a quench to very low and to finite temperatures T is analyzed by scaling theory and Monte Carlo simulation. The model studied has continuous variables, non-conserved order parameter and has two kinds of domain walls: sharp, straight stacking faults and broad curved soliton-like walls. For quenches to higher temperatures the growth exponent is found to approach the classical Allen-Cahn exponent n = 1/2. (A.C.A.S.) [pt

Selenophene transition metal complexes

Energy Technology Data Exchange (ETDEWEB)

White, Carter James [Iowa State Univ., Ames, IA (United States)

1994-07-27

This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η⁵- and the η¹(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The ⁷⁷Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η¹(S)-bound thiophenes, η¹(S)-benzothiophene and η¹(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η¹(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh₃)Re(2-benzothioenylcarbene)]O₃SCF₃ was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η¹(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

Two mode optical fiber in space optics communication

Science.gov (United States)

Hampl, Martin

2017-11-01

In our contribution we propose to use of a two-mode optical fiber as a primary source in a transmitting optical head instead of the laser diode. The distribution of the optical intensity and the complex degree of the coherence on the output aperture of the lens that is irradiated by a step-index weakly guiding optical fiber is investigated. In our treatment we take into account weakly guided modes with polarization corrections to the propagation constant and unified theory of second order coherence and polarization of electromagnetic beams.

Kinetic analysis of MHD ballooning modes in tokamaks

International Nuclear Information System (INIS)

Tang, W.M.; Rewoldt, G.; Cheng, C.Z.; Chance, M.S.

1984-10-01

A comprehensive analysis of the stability properties of the appropriate kinetically generalized form of MHD ballooning modes together with the usual trapped-particle drift modes is presented. The calculations are fully electromagnetic and include the complete dynamics associated with compressional ion acoustic waves. Trapped-particle effects along with all forms of collisionless dissipation are taken into account without approximations. The influence of collisions is estimated with a model Krook operator. Results from the application of this analysis to realistic tokamak operating conditions indicate that unstable short-wavelength modes with significant growth rates can extend from β = 0 to value above the upper ideal-MHD-critical-beta associated with the so-called second stability regime. Since the strength of the relevant modes appears to vary gradually with β, these results support a soft beta limit picture involving a continuous (rather than abrupt or hard) modification of anomalous transport already present in low-β-tokamaks. However, at higher beta the increasing dominance of the electromagnetic component of the perturbations indicated by these calculations could also imply significantly different transport scaling properties

Turnarounds to Transfer: Design beyond the Modes

Science.gov (United States)

Eddy, Jennifer

2014-01-01

In "Turnarounds to Transfer," teachers design a collection of tasks toward the summative performance goal but go beyond the Communicative mode criteria: they must assess for transfer. Transfer design criteria must include a complexity or variation that make learners engage critical thinking skills and call upon a repertoire of knowledge…

PLC-based mode multi/demultiplexers for mode division multiplexing

Science.gov (United States)

Saitoh, Kunimasa; Hanzawa, Nobutomo; Sakamoto, Taiji; Fujisawa, Takeshi; Yamashita, Yoko; Matsui, Takashi; Tsujikawa, Kyozo; Nakajima, Kazuhide

2017-02-01

Recently developed PLC-based mode multi/demultiplexers (MUX/DEMUXs) for mode division multiplexing (MDM) transmission are reviewed. We firstly show the operation principle and basic characteristics of PLC-based MUX/DEMUXs with an asymmetric directional coupler (ADC). We then demonstrate the 3-mode (2LP-mode) multiplexing of the LP01, LP11a, and LP11b modes by using fabricated PLC-based mode MUX/DEMUX on one chip. In order to excite LP11b mode in the same plane, a PLC-based LP11 mode rotator is introduced. Finally, we show the PLC-based 6-mode (4LP-mode) MUX/DEMUX with a uniform height by using ADCs, LP11 mode rotators, and tapered waveguides. It is shown that the LP21a mode can be excited from the LP11b mode by using ADC, and the two nearly degenerated LP21b and LP02 modes can be (de)multiplexed separately by using tapered mode converter from E13 (E31) mode to LP21b (LP02) mode.

Lung growth and development.

Science.gov (United States)

Joshi, Suchita; Kotecha, Sailesh

2007-12-01

Human lung growth starts as a primitive lung bud in early embryonic life and undergoes several morphological stages which continue into postnatal life. Each stage of lung growth is a result of complex and tightly regulated events governed by physical, environmental, hormonal and genetic factors. Fetal lung liquid and fetal breathing movements are by far the most important determinants of lung growth. Although timing of the stages of lung growth in animals do not mimic that of human, numerous animal studies, mainly on sheep and rat, have given us a better understanding of the regulators of lung growth. Insight into the genetic basis of lung growth has helped us understand and improve management of complex life threatening congenital abnormalities such as congenital diaphragmatic hernia and pulmonary hypoplasia. Although advances in perinatal medicine have improved survival of preterm infants, premature birth is perhaps still the most important factor for adverse lung growth.

Effects of growth rate on structural property and adatom migration behaviors for growth of GaInNAs/GaAs (001) by molecular beam epitaxy

Science.gov (United States)

Li, Jingling; Gao, Peng; Zhang, Shuguang; Wen, Lei; Gao, Fangliang; Li, Guoqiang

2018-03-01

We have investigated the structural properties and the growth mode of GaInNAs films prepared at different growth rates (Rg) by molecular beam epitaxy. The crystalline structure is studied by high resolution X-ray diffraction, and the evolution of GaInNAs film surface morphologies is studied by atomic force microscopy. It is found that both the crystallinity and the surface roughness are improved by increasing Rg, and the change in the growth mode is attributed to the adatom migration behaviors particularly for In atoms, which is verified by elemental analysis. In addition, we have presented some theoretical calculation results related to the N adsorption energy to show the unique N migration behavior, which is instructive to interpret the growth mechanism of GaInNAs films.

Neoclassical tearing modes in a tokamak

International Nuclear Information System (INIS)

Hahm, T.S.

1988-08-01

Linear tearing instability is studied in the banana collisionality regime in tokamak geometry. Neoclassical effects produce significant modifications of Ohm's law and the vorticity equation so that the growth rate of tearing modes driven by Δ' is dramatically reduced compared to the usual resistive MHD value. Consequences of this result, regarding the presence of pressure-gradient-driven neoclassical resistive interchange instabilities and the evolution of magnetic islands in the Rutherford regime, are discussed. 10 refs

MHD [magnetohydrodynamic] modes driven by anomalous electron viscosity and their role in fast sawtooth crashes

International Nuclear Information System (INIS)

Aydemir, A.Y.

1990-01-01

We derive the dispersion relations for both small and large-Δ' modes (m ≥ 2, and m = 1 modes, respectively) driven by anomalous electron viscosity. Under the assumption that the anomalous kinematic electron viscosity is comparable to the anomalous electron thermal diffusivity, we find that the viscous mode typically has a higher growth rate than the corresponding resistive mode. We compare computational results in cylindrical and toroidal geometries with theory and present some nonlinear results for viscous m = 1 modes in both circular and D-shaped boundaries and discuss their possible rile in fast sawtooth crashes. 30 ref., 5 figs., 1 tab

Dynamics of coupled mode solitons in bursting neural networks

Science.gov (United States)

Nfor, N. Oma; Ghomsi, P. Guemkam; Moukam Kakmeni, F. M.

2018-02-01

Using an electrically coupled chain of Hindmarsh-Rose neural models, we analytically derived the nonlinearly coupled complex Ginzburg-Landau equations. This is realized by superimposing the lower and upper cutoff modes of wave propagation and by employing the multiple scale expansions in the semidiscrete approximation. We explore the modified Hirota method to analytically obtain the bright-bright pulse soliton solutions of our nonlinearly coupled equations. With these bright solitons as initial conditions of our numerical scheme, and knowing that electrical signals are the basis of information transfer in the nervous system, it is found that prior to collisions at the boundaries of the network, neural information is purely conveyed by bisolitons at lower cutoff mode. After collision, the bisolitons are completely annihilated and neural information is now relayed by the upper cutoff mode via the propagation of plane waves. It is also shown that the linear gain of the system is inextricably linked to the complex physiological mechanisms of ion mobility, since the speeds and spatial profiles of the coupled nerve impulses vary with the gain. A linear stability analysis performed on the coupled system mainly confirms the instability of plane waves in the neural network, with a glaring example of the transition of weak plane waves into a dark soliton and then static kinks. Numerical simulations have confirmed the annihilation phenomenon subsequent to collision in neural systems. They equally showed that the symmetry breaking of the pulse solution of the system leaves in the network static internal modes, sometime referred to as Goldstone modes.

Comparative Study of Various Normal Mode Analysis Techniques Based on Partial Hessians

OpenAIRE

GHYSELS, AN; VAN SPEYBROECK, VERONIQUE; PAUWELS, EWALD; CATAK, SARON; BROOKS, BERNARD R.; VAN NECK, DIMITRI; WAROQUIER, MICHEL

2010-01-01

Standard normal mode analysis becomes problematic for complex molecular systems, as a result of both the high computational cost and the excessive amount of information when the full Hessian matrix is used. Several partial Hessian methods have been proposed in the literature, yielding approximate normal modes. These methods aim at reducing the computational load and/or calculating only the relevant normal modes of interest in a specific application. Each method has its own (dis)advantages and...

Sausage mode of a high density Z-pinch

International Nuclear Information System (INIS)

Pereira, N.; Rostoker, N.

1983-01-01

In Z-pinch experiments at Maxwell Laboratories, Inc., growth rates have been measured by observing optical emission along the pinch axis. Growth rates estimated by means of the usual model of a pinch involving an incompressible fluid and a surface current are too large by a factor of 2-4. X-ray pinhole photographs generally have the appearance of a series of beads that would be expected from instability of the sausage mode. In some cases, particularly the implosion of large diameter wire arrays with BLACKJACK 5, the beads disappear and only the kink instability is apparent. Generalizing the pinch model to include compressibility does not significantly alter the predictions. A further generalization to include distributed current has therefore been considered. It seems likely that the current can penetrate significantly during the lifetime of the pinch. We consider a model of the pinch that is initially an infinite cylinder. For the sausage mode, stability is determined by a simple second order differential equation together with the boundary condition that follows from the wave number and the frequency of the instability

Energetic ion excited long-lasting ``sword'' modes in tokamak plasmas with low magnetic shear

Science.gov (United States)

Wang, Xiaogang; Zhang, Ruibin; Deng, Wei; Liu, Yi

2013-10-01

An m/ n = 1 mode driven by trapped fast ions with a sword-shape envelope of long-lasting (for hundreds of milliseconds) magnetic perturbation signals, other than conventional fishbones, is studied in this paper. The mode is usually observed in low shear plasmas. Frequency and growth rate of the mode and its harmonics are calculated and in good agreements with observations. The radial mode structure is also obtained and compared with that of fishbones. It is found that due to fast ion driven the mode differs from magnetohydrodynamic long lived modes (LLMs) observed in MAST and NSTX. On the other hand, due to the feature of weak magnetic shear, the mode is also significantly different from fishbones. The nonlinear evolution of the mode and its comparison with fishbones are further investigated to analyze the effect of the mode on energetic particle transport and confinement.

Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

OpenAIRE

Yu-zhu ZHANG; Yang LIU; Xiang ZENG; Kai-lin CHEN; Ze-hui HUANG; Hong-ke XIE

2011-01-01

The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological...

Comparison of L- and H-mode plasma edge fluctuations in MAST

International Nuclear Information System (INIS)

Dudson, B D; Dendy, R O; Kirk, A; Meyer, H; Counsell, G F

2005-01-01

Edge turbulence measurements from a reciprocating Langmuir probe in MAST are presented. A comparison of the range/standard deviation (R/S), growth of range, first moment and differencing and rescaling methods for calculating the Hurst exponent is made. The differencing and rescaling method is found to be the most useful for identifying scaling over long time-periods. A comparison is made between L-mode, dithering H-mode and H-mode plasma edge turbulence and evidence for self-similarity is found. Tests are performed and it is demonstrated that the results are due to properties of the data, and are not artefacts of the methods. A comparison of Hurst exponent methods with the autocorrelation function and power spectrum is used to demonstrate the presence of long-time correlation in L-mode data, and the absence of long-time correlation in the case of dithering H-mode

A CALCULATION METHOD OF TRANSIENT MODES OF ELECTRIC SHIPS’ PROPELLING ELECTRIC PLANTS

Directory of Open Access Journals (Sweden)

V. A. Yarovenko

2017-12-01

Full Text Available The purpose of the work is to develop the method for calculating the transient modes of electric ships’ propelling electric plants during maneuver. This will allow us to evaluate and improve the maneuverability of vessels with electric motion. Methodology. The solution to the problems is proposed to be carried out on the basis of mathematical modeling of maneuvering modes. The duration of transient modes in an electric power plant at electric ships’ maneuvers is commensurable with the transient operation modes of the vessel itself. Therefore, the analysis of the electric power plants’ maneuvering modes should be made in unity with all the components of the ship’s propulsion complex. Results. A specified mathematical model of transient regimes of electric ship’s propulsion complex, including thermal motors, synchronous generators, electric power converters, propulsion motors, propellers, rudder, ship’s hull is developed. The model is universal. It covers the vast majority of modern and promising electric ships with a traditional type of propulsors. It allows calculating the current values of the basic mode indicators and assessing the quality indicators of maneuvering. The model is made in relative units. Dimensionless parameters of the complex are obtained. These parameters influence the main indicators of the quality of maneuvering. The adequacy of the suggested specified mathematical model and the developed computation method based on it were confirmed. To do this, the results of mathematical modeling for a real electric ship were compared with the data obtained in the course of field experiments conducted by other researchers. Originality. The mathematical description of a generator unit, as an integral part of an indivisible ship’s propulsion complex, makes it possible to calculate the dynamic operation modes of electric power sources during electric vessels’ maneuvering. There is an opportunity to design the electric ships�

Complex modes and frequencies in damped structural vibrations

DEFF Research Database (Denmark)

Krenk, Steen

2004-01-01

It is demonstrated that the state space formulation of the equation of motion of damped structural elements like cables and beams leads to a symmetric eigenvalue problem if the stiffness and damping operators are self-adjoint, and that this is typically the case in the absence of gyroscopic forces....... The corresponding theory of complex modal analysis of continuous systems is developed and illustrated in relation to optimal damping and impulse response of cables and beams with discrete dampers....

On the ordinary mode instability for low beta plasmas

Energy Technology Data Exchange (ETDEWEB)

Hadi, F.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar (Pakistan); Bashir, M. F. [Department of Physics, G. C. University, Lahore (Pakistan); Salam Chair in Physics, G. C. University, Lahore (Pakistan); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742-2431 (United States); School of Space Research, Kyung Hee University, Yongin (Korea, Republic of); Schlickeiser, R. [Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- and Astrophysik, Ruhr-Universität, Bochum (Germany)

2014-05-15

The purely growing ordinary (O) mode instability, first discussed by Davidson and Wu [Phys. Fluids 13, 1407 (1970)], has recently received renewed attention owing to its potential applicability to the solar wind plasma. In a series of papers, Ibscher, Schlickeiser, and their colleagues [Phys. Plasmas 19, 072116 (2012); ibid. 20, 012103 (2013); ibid. 20, 042121 (2013); ibid. 21, 022110 (2014)] revisited the O mode instability and extended it to the low-beta plasma regime by considering a counter-streaming bi-Maxwellian model. However, the O-mode instability is, thus, far discussed only on the basis of the marginal stability condition rather than actual numerical solutions of the dispersion relation. The present paper revisits the O-mode instability by considering the actual complex roots. The marginal stability condition as a function of the (electron) temperature anisotropy and beta naturally emerges in such a scheme.

Non-linear coupling of drift modes in a quadrupole

International Nuclear Information System (INIS)

Elliott, J.A.; Sandeman, J.C.; Tessema, G.Y.

1990-01-01

We report continuing experimental studies of non-linear interactions of drift waves, with direct evidence of a growth saturation mechanism by transfer of energy to lower frequency modes. Wave launching experiments show that the decay rate of drift waves can be strongly amplitude dependent. (author) 9 refs., 5 figs

Compressibility effects on ideal and kinetic ballooning modes and elimination of finite Larmor radius stabilization

International Nuclear Information System (INIS)

Kotschenreuther, M.

1985-07-01

The dynamics of ideal and kinetic ballooning modes are considered analytically including parallel ion dynamics, but without electron dissipation. For ideal modes, parallel dynamics predominantly determine the growth rate when β is within approx.30% of the ideal threshold, resulting in a substantial reduction in growth rate. Compressibility also eliminates the stabilization effects of finite Larmor radius (FLR); FLR effects (when temperature gradients are neglected) can even increase the growth rate above the MHD value. Temperature gradients accentuate this by adding a new source of free energy independent of the MHD drive, in this region of ballooning coordinate corresponding in MHD to the continuum. Analytic dispersion relations are derived demonstrating the effects above; the formalism emphasizes the similarities between the ideal MHD and kinetic cases

The effect of size and competition on tree growth rate in old-growth coniferous forests

Science.gov (United States)

Das, Adrian

2012-01-01

Tree growth and competition play central roles in forest dynamics. Yet models of competition often neglect important variation in species-specific responses. Furthermore, functions used to model changes in growth rate with size do not always allow for potential complexity. Using a large data set from old-growth forests in California, models were parameterized relating growth rate to tree size and competition for four common species. Several functions relating growth rate to size were tested. Competition models included parameters for tree size, competitor size, and competitor distance. Competitive strength was allowed to vary by species. The best ranked models (using Akaike’s information criterion) explained between 18% and 40% of the variance in growth rate, with each species showing a strong response to competition. Models indicated that relationships between competition and growth varied substantially among species. The results also suggested that the relationship between growth rate and tree size can be complex and that how we model it can affect not only our ability to detect that complexity but also whether we obtain misleading results. In this case, for three of four species, the best model captured an apparent and unexpected decline in potential growth rate for the smallest trees in the data set.

CASTOR: Normal-mode analysis of resistive MHD plasmas

NARCIS (Netherlands)

Kerner, W.; Goedbloed, J. P.; Huysmans, G. T. A.; Poedts, S.; Schwarz, E.

1998-01-01

The CASTOR (complex Alfven spectrum of toroidal plasmas) code computes the entire spectrum of normal-modes in resistive MHD for general tokamak configurations. The applied Galerkin method, in conjunction with a Fourier finite-element discretisation, leads to a large scale eigenvalue problem A (x)

Parameter spaces for linear and nonlinear whistler-mode waves

International Nuclear Information System (INIS)

Summers, Danny; Tang, Rongxin; Omura, Yoshiharu; Lee, Dong-Hun

2013-01-01

We examine the growth of magnetospheric whistler-mode waves which comprises a linear growth phase followed by a nonlinear growth phase. We construct time-profiles for the wave amplitude that smoothly match at the transition between linear and nonlinear wave growth. This matching procedure can only take place over a limited “matching region” in (N h /N 0 ,A T )-space, where A T is the electron thermal anisotropy, N h is the hot (energetic) electron number density, and N 0 is the cold (background) electron number density. We construct this matching region and determine how the matching wave amplitude varies throughout the region. Further, we specify a boundary in (N h /N 0 ,A T )-space that separates a region where only linear chorus wave growth can occur from the region in which fully nonlinear chorus growth is possible. We expect that this boundary should prove of practical use in performing computationally expensive full-scale particle simulations, and in interpreting experimental wave data

Using a system of differential equations that models cattle growth to uncover the genetic basis of complex traits.

Science.gov (United States)

Freua, Mateus Castelani; Santana, Miguel Henrique de Almeida; Ventura, Ricardo Vieira; Tedeschi, Luis Orlindo; Ferraz, José Bento Sterman

2017-08-01

The interplay between dynamic models of biological systems and genomics is based on the assumption that genetic variation of the complex trait (i.e., outcome of model behavior) arises from component traits (i.e., model parameters) in lower hierarchical levels. In order to provide a proof of concept of this statement for a cattle growth model, we ask whether model parameters map genomic regions that harbor quantitative trait loci (QTLs) already described for the complex trait. We conducted a genome-wide association study (GWAS) with a Bayesian hierarchical LASSO method in two parameters of the Davis Growth Model, a system of three ordinary differential equations describing DNA accretion, protein synthesis and degradation, and fat synthesis. Phenotypic and genotypic data were available for 893 Nellore (Bos indicus) cattle. Computed values for parameter k 1 (DNA accretion rate) ranged from 0.005 ± 0.003 and for α (constant for energy for maintenance requirement) 0.134 ± 0.024. The expected biological interpretation of the parameters is confirmed by QTLs mapped for k 1 and α. QTLs within genomic regions mapped for k 1 are expected to be correlated with the DNA pool: body size and weight. Single nucleotide polymorphisms (SNPs) which were significant for α mapped QTLs that had already been associated with residual feed intake, feed conversion ratio, average daily gain (ADG), body weight, and also dry matter intake. SNPs identified for k 1 were able to additionally explain 2.2% of the phenotypic variability of the complex ADG, even when SNPs for k 1 did not match the genomic regions associated with ADG. Although improvements are needed, our findings suggest that genomic analysis on component traits may help to uncover the genetic basis of more complex traits, particularly when lower biological hierarchies are mechanistically described by mathematical simulation models.

Synthesis, crystal growth, structural and physicochemical studies of novel binary organic complex: 4-chloroaniline–3-hydroxy-4-methoxybenzaldehyde

International Nuclear Information System (INIS)

Sharma, K.P.; Reddi, R.S.B.; Bhattacharya, S.; Rai, R.N.

2012-01-01

The solid-state reaction, which is solvent free and green synthesis, has been adopted to explore the novel compound. The phase diagram of 4-chloroaniline (CA) and 3-hydroxy-4-methoxybenzaldehyde (HMB) system shows the formation of a novel 1:1 molecular complex, and two eutectics on either sides of complex. Thermochemical studies of complex and eutectics have been carried out for various properties such as heat of fusion, entropy of fusion, Jackson's parameters, interfacial energy and excess thermodynamic functions. The formation of molecular complex was also studied by IR, NMR, elemental analysis and UV–Vis absorption spectra. The single crystal of molecular complex was grown and its XRD study confirms the formation of complex and identifies the crystal structure and atomic packing of crystal of complex. Transmission spectra of grown crystal of the complex show 70% transmittance efficiency with cut off wavelength 412 nm. The band gap and refractive index of the crystal of complex have also been studied. - Graphical abstarct: Exploiting phase diagram study and solvent free synthesis a novel compound was synthesized and its single crystal growth, atomic packing, energy band gap and refractive index were studied. Highlights: ► Novel organic complex was synthesized using Green or solvent free synthesis. ► Phase diagram study provided the information to identify the worthy composition of novel complex. ► The single crystal of the sufficient size was grown from the ethanol solution. ► Crystal analysis suggested that the covalent bond is formed between the two parent compounds. ► The transmittance of the crystal was found to be 70% and it was transparent from 412 to 850 nm.

Spatial-mode switchable ring fiber laser based on low mode-crosstalk all-fiber mode MUX/DEMUX

Science.gov (United States)

Ren, Fang; Yu, Jinyi; Wang, Jianping

2018-05-01

We report an all-fiber ring laser that emits linearly polarized (LP) modes based on the intracavity all-fiber mode multiplexer/demultiplexer (MUX/DEMUX). Multiple LP modes in ring fiber laser are generated by taking advantage of mode MUX/DEMUX. The all-fiber mode MUX/DEMUX are composed of cascaded mode-selective couplers (MSCs). The output lasing mode of the ring fiber laser can be switched among the three lowest-order LP modes by employing combination of a mode MUX and a simple N × 1 optical switch. The slope efficiencies, optical spectra and mode profiles are measured.