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1

Energy Technology Data Exchange (ETDEWEB)

For a processing and an interpretation of correct seismic data, it is necessary to recognize and to know as the factors act that influence in the propagation of the seismic waves, as the attenuation and the dispersion, constituting in the biggest practical impediment for the use of seismic for targets the big depths, limiting the resolution of the method. However these phenomena little are taken in consideration in the analysis of the data, thus the necessity of its bigger agreement, because if attenuation and dispersion they confuse the application of the seismic, if convenient understood and measures, can be valuable sources of information about the constitution of the rocks. Therefore, in this work the effect of the attenuation and dispersion in the data of reflection seismic had been simulated on a program, in Mat-Lab. Being able to generate 1-D seismograms, in the domain of the time, considering the normal incidence of plain wave in a package of plain, horizontal and isotropic layers, taking in account the physical attributes of the way, being able to simulate the effects of ghost and of multiples of free surface, if considering the source in the water. (author)

Rodrigues, Bruno de O.; Oliveira, Sergio A.M. de [Universidade Estadual do Norte Fluminense (UENF), Macae, RJ (Brazil). Lab. de Engenharia e Exploracao do Petroleo (LENEP)

2004-07-01

2

Broadband (0.1-20 Hz) synthetic seismograms for finite-fault sources were produced for a model where stress drop is constant with seismic moment to see if they can match the magnitude dependence and distance decay of response spectral amplitudes found in the Next Generation Attenuation (NGA) relations recently developed from strong-motion data of crustal earthquakes in tectonically active regions. The broadband synthetics were constructed for earthquakes of M 5.5, 6.5, and 7.5 by combining deterministic synthetics for plane-layered models at low frequencies with stochastic synthetics at high frequencies. The stochastic portion used a source model where the Brune stress drop of 100 bars is constant with seismic moment. The deterministic synthetics were calculated using an average slip velocity, and hence, dynamic stress drop, on the fault that is uniform with magnitude. One novel aspect of this procedure is that the transition frequency between the deterministic and stochastic portions varied with magnitude, so that the transition frequency is inversely related to the rise time of slip on the fault. The spectral accelerations at 0.2, 1.0, and 3.0 sec periods from the synthetics generally agreed with those from the set of NGA relations for M 5.5-7.5 for distances of 2-100 km. At distances of 100-200 km some of the NGA relations for 0.2 sec spectral acceleration were substantially larger than the values of the synthetics for M 7.5 and M 6.5 earthquakes because these relations do not have a term accounting for Q. At 3 and 5 sec periods, the synthetics for M 7.5 earthquakes generally had larger spectral accelerations than the NGA relations, although there was large scatter in the results from the synthetics. The synthetics showed a sag in response spectra at close-in distances for M 5.5 between 0.3 and 0.7 sec that is not predicted from the NGA relations.

Frankel, A.

2009-01-01

3

Synthetic seismogram web service and Python tools

Many geophysical methods require knowledge of Green's functions (GF) or synthetic seismograms in dependence of ranges of source and receiver coordinates. Examples include synthetic seismogram generation, moment tensor inversion, the modeling of depth phases for regional and teleseismic earthquakes, or the modeling of pressure diffusion induced static displacement and strain. Calculation of Green's functions is a computationally expensive operation and it can be of advantage to calculate them in advance: the same Green's function traces can then be reused several or many times as required in a typical application. Regarding Green's function computation as an independent step in a use-case's processing chain encourages to store these in an application independent form. They can then be shared between different applications and they can also be passed to other researchers, e.g. via a web service. Starting now, we provide such a web service to the seismological community (http://kinherd.org/), where a researcher can share Green's function stores and retrieve synthetic seismograms for various point and extended earthquake source models for many different earth models at local, regional and global scale. This web service is part of a rich new toolset for the creation and handling of Green's functions and synthetic seismograms (http://emolch.github.com/pyrocko/gf). It can be used off-line or in client mode. Its core features are: greatly simplified generation of Green's function stores supports various codes for Green's function computation extensible Green's function storage format flexible spacial indexing of Green's functions integrated travel time computation support for other types of Green's functions; e.g. poro-elastic GFs written in Python

Heimann, Sebastian; Cesca, Simone; Kriegerowski, Marius; Dahm, Torsten

2014-05-01

4

Streaming Seismograms into Earth-Science Classrooms

Seismograms are the fundamental observations upon which seismology is based; they are central to any course in seismology and important for any discussion of earthquake-related phenomena based on seismic observations. Advances in the collection and distribution of seismic data have made the use of research-quality seismograms in any network capable classroom feasible. The development of large, deep seismogram archives place an unprecedented quantity of high-quality data within reach of the modern classroom environment. I describe and discuss several computer tools and classroom activities that I use in introductory (general education) and advanced undergraduate courses that present near real-time research-quality seismic observations in the classroom. The Earth Motion Monitor Application (EMMA), is a MacOS application that presents a visually clear seismogram display that can be projected in classrooms with internet access. Seismic signals from thousands of station are available from the IRIS data center and the bandwidth can be tailored to the particular type of signal of interest (large event, low frequencies; small event, high frequencies). In introductory classes for non-science students, the near realtime display routinely shows magnitude 4.0-5.0 earthquake-generated signals, demonstrating to students the frequency of earthquake occurrence. Over the next few minutes as the waves travel through and across the planet, their arrival on the seismogram display provides some basic data for a qualitative estimate of the event's general location. When a major or great earthquake occurs, a broad-band display of signals from nearby stations can dramatically and dynamically illuminate the frequent activity associated with the aftershock sequence. Routine use of the display (while continuing the traditional classroom activities) provides students with a significant dose of seismogram study. Students generally find all the signals, including variations in seismic background motions, interesting and formulate good questions related to the signal details. A few minutes at the beginning of class reviewing the activity between classes and a few minutes when an earthquake occurs provide valuable discussion points related to earthquake science and seismic-wave propagation. Other tools discussed are related to global earthquake geography, with self-updating global maps of earthquakes (Epicentral, a MacOS and iOS application). When a signal first shows up on the EMMA seismogram display, students can invest a few minutes estimating the event's general location (and checking the signal character - relative arrival times, dispersion, etc). When a location is posted by an appropriate authority (e.g. the U. S. Geological Survey) the student's estimates can be checked and discussed. Additionally, Epicentral for MacOS presents a self-updated Twitter stream that can light up substantially when a felt earthquake occurs. Although the language of many of the tweeters can be colorful, the results are interesting and instant. The inclusion of these tools takes some time away from traditional lectures, but helps produce a dynamic, thought-provoking classroom experience.

Ammon, C. J.

2011-12-01

5

Net current generation in a 1D quantum ring at zero magnetic field

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study a non-adiabatic excitation of an electron system in a 1D quantum ring radiated by a short THz pulse. The response of two models, a continuous and discrete, is explored. By introducing a spatial asymmetry in the external perturbation a net current can be generated in the ring at a zero magnetic field. Effect of impurities and ratchets are investigated in combination with symmetric and asymmetric external excitation.

Gylfadottir, Sigridur Sif; Nita, Marian; Gudmundsson, Vidar; Manolescu, Andrei

2004-01-01

6

Human CD1d–glycolipid tetramers generated by in vitro oxidative refolding chromatography

Digital Repository Infrastructure Vision for European Research (DRIVER)

CD1 molecules are specialized in presenting lipids to T lymphocytes, but identification and isolation of CD1-restricted lipidspecific T cells has been hampered by the lack of reliable and sensitive techniques. We here report the construction of CD1d–glycolipid tetramers from fully denatured human CD1d molecules by using the technique of oxidative refolding chromatography. We demonstrate that chaperone- and foldase-assisted refolding of denatured CD1d molecules an...

Karadimitris, Anastasios; Gadola, Stephan; Altamirano, Myriam; Brown, Dave; Woolfson, Adrian; Klenerman, Paul; Chen, Ji-li; Koezuka, Yasuhiko; Roberts, Irene A. G.; Price, David A.; Dusheiko, Geoff; Milstein, Ce?sar; Fersht, Alan; Luzzatto, Lucio; Cerundolo, Vincenzo

2001-01-01

7

1.D wake field generation by Ultra short laser chirp pulse in plasmas

International Nuclear Information System (INIS)

The nonlinear interaction of ultra-short chirp laser pulse with a uniform plasmas is studied numerically in 1-D. It is shown that positive chirp pulse increase wake field amplitude significantly . Furthermore, optimum value for pulse length is obtained about 0.2?p

2007-08-27

8

Hybrid 0-D, 1-D, and 2-D model of helical explosive-driven magnetic flux compression generator

Energy Technology Data Exchange (ETDEWEB)

We describe a hybrid code model of the Sandia National Laboratories' model 632, a very large explosive-driven magnetic flux compression generator. This involves the use of two codes. The first is a coupled 0-D equivalent circuit model and 1-D magnetohydrodynamic computation. The second is the 2-D materials response code, CSQ. This is used to obtain an equivalent ''drag coefficient'' so that the 2-D stator coil conductor-encapsulent interaction can be modeled in the 1-D code.

Burgess, T.J.

1985-01-01

9

Generation of Nonclassical Microwave States Using an Artificial Atom in 1D Open Space

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have embedded an artificial atom, a superconducting transmon qubit, in a 1D open space and investigated the scattering properties of an incident microwave coherent state. By studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. In particular, by measuring the second-order correlation function, g(2), we show photon antibunching in the reflected field and superbunching in the transmitted field. We also compare the elast...

2012-01-01

10

Generation of nonclassical microwave states using an artificial atom in 1D open space

We have embedded an artificial atom, a superconducting transmon qubit, in a 1D open space and investigated the scattering properties of an incident microwave coherent state. By studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. In particular, by measuring the second-order correlation function, $g^{(2)}$, we show photon antibunching in the reflected field and superbunching in the transmitted field. We also compare the elastically and inelastically scattered fields using both phase-sensitive and phase-insensitive measurements.

Hoi, Io-Chun; Johansson, Göran; Lindkvist, Joel; Delsing, Per; Wilson, C M

2012-01-01

11

Generation of nonclassical microwave states using an artificial atom in 1D open space.

We have embedded an artificial atom, a superconducting transmon qubit, in a 1D open space and investigated the scattering properties of an incident microwave coherent state. By studying the statistics of the reflected and transmitted fields, we demonstrate that the scattered states can be nonclassical. In particular, by measuring the second-order correlation function, g((2)), we show photon antibunching in the reflected field and superbunching in the transmitted field. We also compare the elastically and inelastically scattered fields using both phase-sensitive and phase-insensitive measurements. PMID:23004976

Hoi, Io-Chun; Palomaki, Tauno; Lindkvist, Joel; Johansson, Göran; Delsing, Per; Wilson, C M

2012-06-29

12

The high-gain harmonic generation (HGHG) free-electron laser (FEL) is an important candidate for a fourth-generation light source. Lots of theoretical work has been performed. Recently a further 1D theory about HGHG FEL has been developed. It considers the effects of different parameters for the whole process. An initial program based on this theory has been made. In this paper, a brief comparison of the results from this 1D program and from TDA (3D code) is discussed. It also analyses the parameters for Shanghai deep ultra violate free-electron laser source (SDUV-FEL), including electron beam energy spread, seed laser power, strength of dispersion section etc.

Li, Yuhui; Zhang, Shancai

2004-01-01

13

jSynthesizer: A Java based first-motion synthetic seismogram tool

Both researchers and educators need software tools to create synthetic seismograms to model earthquake sources. We have developed a program that generates first-motion synthetic seismograms that is highly interactive and suited to the needs of both research and education audiences. Implemented in the Java programming language, our program is available for use on Windows, Mac OS X and Linux operating systems. Our program allows the user to input the fault parameters strike, dip and slip angle, numerically or graphically using a lower hemisphere equal-area stereographic projection of the focal sphere of the earthquake. This representation is familiar to geologists and seismologists as the standard way of displaying the orientation of a fault in space. The user is also able to enter the relative location of the seismograph and the depth and crustal velocity structure in the vicinity of the earthquake. The direct P wave along with reflections off of layer boundaries near the source are generated using a constant ray-parameter approximation. The instrument response functions used by the Worldwide Standardized Seismogram Network and the attenuation response of the Earth's mantle are generated in the frequency domain and applied to generate the synthetic seismogram. Planned enhancements to this program will allow the simultaneous generation of seismograms at many stations as well as more complicated crustal structures.

Sullivan, Mark

2009-10-01

14

Stratigraphic and structural interpretations by using diffraction seismograms

Energy Technology Data Exchange (ETDEWEB)

A two-dimensional seismic diffraction modeling method has been applied to an east-west cross section of Bay Marchand located 1 1/2 mi north of the Bay Marchand/South Timbalier area boundary in block 2 through block 4 of T23S, R23E. A 20-layer geologic depth model has been constructed from the correlation of SP-induction and sonic well logs. Each layer has been assigned a velocity determined from the corresponding sonic logs and a density approximated from Gardner's rule. A synthetic seismogram has been generated due to the geologic depth model using diffraction modeling computer code.

Snavely, R.K.; Sarwar, A.K.M.

1988-09-01

15

Computing Uniformly Asymptotic Seismograms Using Complex Ray Tracing

Methods based on ray tracing are the tool of choice for modeling wave propagation through heterogeneous media at high frequencies. Reliable computation of amplitudes near caustics are still a problem though. We present a new method to compute these amplitudes accurately using complex rays and polynomial phase functions. This method allows the determination of global uniformly asymptotic solutions to the wave equation in the presence of arbitrarily many caustics. The model representation is done using the discrete cosine transform, rather than cubic splines. This way the velocity model can be analytically continued without higher order discontinuities at the interfaces of the interpolation cells. The complex two-point ray tracing is done efficiently, thus avoiding a global search of complex space. With this method amplitudes are not only correctly computed near caustics but also in the shadow zones. Seismograms are computed for both geometrical and uniformly asymptotic solutions, using a velocity model from the Yucca Mountain test site that generates caustics.

Amodei, D.; Keers, H.; Vasco, D.; Johnson, L.

2005-12-01

16

Energy Technology Data Exchange (ETDEWEB)

A new 1D core-shell strategy is demonstrated for a hydrogen-generation photo-electrochemical cell (PEC). This Si/iodine-doped poly(3,4-ethylenedioxythiophene) (PEDOT) 1D nanocable array shows an encouraging solar-to-chemical energy-conversion efficiency. Coating with iodine-doped PEDOT can effectively enhance the photocatalytic efficiency and stability of SiNW arrays. The PEC model proposed shows a potentially promising structure for H{sub 2} production using solar energy. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Yang, Tian; Wang, Hui; Ou, Xue-Mei; Zhang, Xiao-Hong [Nano-organic Photoelectronic Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Lee, Chun-Sing [Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Sciences, City University of Hong Kong, Hong Kong SAR (China)

2012-12-04

17

Blind deconvolution of seismograms regularized via minimum support

International Nuclear Information System (INIS)

The separation of earthquake source signature and propagation effects (the Earth’s ‘Green’s function’) that encode a seismogram is a challenging problem in seismology. The task of separating these two effects is called blind deconvolution. By considering seismograms of multiple earthquakes from similar locations recorded at a given station and that therefore share the same Green’s function, we may write a linear relation in the time domain ui(t)*sj(t) ? uj(t)*si(t) = 0, where ui(t) is the seismogram for the ith source and sj(t) is the jth unknown source. The symbol * represents the convolution operator. From two or more seismograms, we obtain a homogeneous linear system where the unknowns are the sources. This system is subject to a scaling constraint to deliver a non-trivial solution. Since source durations are not known a priori and must be determined, we augment our system by introducing the source durations as unknowns and we solve the combined system (sources and source durations) using separation of variables. Our solution is derived using direct linear inversion to recover the sources and Newton’s method to recover source durations. This method is tested using two sets of synthetic seismograms created by convolution of (i) random Gaussian source-time functions and (ii) band-limited sources with a simplified Green’s function and signal to noise levels up to 10% with encouraging results. (paper)

2012-12-01

18

A hybrid method for the computation of quasi-3D seismograms.

The development of powerful computer clusters and efficient numerical computation methods, such as the Spectral Element Method (SEM) made possible the computation of seismic wave propagation in a heterogeneous 3D earth. However, the cost of theses computations is still problematic for global scale tomography that requires hundreds of such simulations. Part of the ongoing research effort is dedicated to the development of faster modeling methods based on the spectral element method. Capdeville et al. (2002) proposed to couple SEM simulations with normal modes calculation (C-SEM). Nissen-Meyer et al. (2007) used 2D SEM simulations to compute 3D seismograms in a 1D earth model. Thanks to these developments, and for the first time, Lekic et al. (2011) developed a 3D global model of the upper mantle using SEM simulations. At the local and continental scale, adjoint tomography that is using a lot of SEM simulation can be implemented on current computers (Tape, Liu et al. 2009). Due to their smaller size, these models offer higher resolution. They provide us with images of the crust and the upper part of the mantle. In an attempt to teleport such local adjoint tomographic inversions into the deep earth, we are developing a hybrid method where SEM computation are limited to a region of interest within the earth. That region can have an arbitrary shape and size. Outside this region, the seismic wavefield is extrapolated to obtain synthetic data at the Earth's surface. A key feature of the method is the use of a time reversal mirror to inject the wavefield induced by distant seismic source into the region of interest (Robertsson and Chapman 2000). We compute synthetic seismograms as follow: Inside the region of interest, we are using regional spectral element software RegSEM to compute wave propagation in 3D. Outside this region, the wavefield is extrapolated to the surface by convolution with the Green's functions from the mirror to the seismic stations. For now, these Green's functions are computed using 2D SEM simulation in a 1D Earth model. Such seismograms account for the 3D structure inside the region of interest in a quasi-exact manner. Later we plan to extrapolate the misfit function computed from such seismograms at the stations back into the SEM region in order to compute local adjoint kernels. This opens a new path toward regional adjoint tomography into the deep Earth. Capdeville, Y., et al. (2002). "Coupling the spectral element method with a modal solution for elastic wave propagation in global Earth models." Geophysical Journal International 152(1): 34-67. Lekic, V. and B. Romanowicz (2011). "Inferring upper-mantle structure by full waveform tomography with the spectral element method." Geophysical Journal International 185(2): 799-831. Nissen-Meyer, T., et al. (2007). "A two-dimensional spectral-element method for computing spherical-earth seismograms-I. Moment-tensor source." Geophysical Journal International 168(3): 1067-1092. Robertsson, J. O. A. and C. H. Chapman (2000). "An efficient method for calculating finite-difference seismograms after model alterations." Geophysics 65(3): 907-918. Tape, C., et al. (2009). "Adjoint tomography of the southern California crust." Science 325(5943): 988-992.

Masson, Yder; Romanowicz, Barbara

2013-04-01

19

Fully digital 1-D, 2-D and 3-D multiscroll chaos as hardware pseudo random number generators

This paper introduces the first fully digital implementation of 1-D, 2-D and 3-D multiscroll chaos using the sawtooth nonlinearity in a 3rd order ODE with the Euler approximation. Systems indicate chaotic behaviour through phase space boundedness and positive Lyapunov exponent. Low-significance bits form a PRNG and pass all tests in the NIST SP. 800-22 suite without post-processing. Real-time control of the number of scrolls allows distinct output streams with 2-D and 3-D multiscroll chaos enabling greater controllability. The proposed PRNGs are experimentally verified on a Xilinx Virtex 4 FPGA with logic utilization less than 1.25%, throughput up to 5.25 Gbits/s and up to 512 distinct output streams with low cross-correlation.

Mansingka, Abhinav S.

2012-10-07

20

Analysis of Rock-Fall and Rock-Fall Avalanche Seismograms in the French Alps

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study reviews seismograms from 10 rock-fall events recorded between 1992 and 2001 by the permanent seismological network Sismalp in the French Alps. A new seismic-magnitude scale was defined that allowed us to compare and classify ground-motion vibrations generated by these Alpine rock falls. Each rock fall has also been characterized by its ground-motion duration t30 at an epicentral distance of 30 km. No relation was found between rock-fall parameters (fall height, runout distance, vol...

Deparis, J.; Jongmans, Denis; Cotton, Fabrice; Baillet, Laurent; Thouvenot, Franc?ois; Hantz, D.

2008-01-01

21

Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods

Directory of Open Access Journals (Sweden)

Full Text Available Using an improved global pseudospectral modeling algorithm we synthesize seismograms generated by oceanic and continental earthquakes. Attention is given to attenuation, to explicit modeling of boundary conditions at the ocean-bottom interface, simulation of the Rayleigh window and interface-wave propagation. The algorithm is based on Fourier and Chebyshev differential operators and a domain-decomposition technique - one grid for the fluid and another grid for the solid. Wave propagation in the oceanic and continent crusts and mantle is modeled by using a viscoelastic stress-strain relation based on memory variables.The main physical phenomena associated with an ocean-crust system are modeled, including Scholte waves, leaking Rayleigh waves, dispersive modes, and the Rayleigh-window phenomenon due to a minimum in the reflection coefficient of the ocean bottom, which has not been simulated with direct methods. In particular, we model Rayleigh modes (mainly the M11 mode, and coupled Rayleigh-Scholte waves, for which the dispersion relation is solved in simple cases. Also, we model the effects of random inhomogeneities in the crust and mantle by using a von Kármán autocovariance probability function, which simulates scattering-Q-effects.The 2-D modeling code allows general material variability, and a complete and accurate characterization of the seismic response of oceanic and continental earthquakes. A synthetic seismogram for an earthquake in the South Atlantic region is provided.

Milton P. Plasencia Linares

2005-11-01

22

Energy Technology Data Exchange (ETDEWEB)

A Faraday ideally segmented (the absence of the Hall electric current I{sub x}=0) MHD generator channel, with a weakly ionized plasma as a working fluid, is considered. The magnetic field is applied along the z axis and the working fluid flows along the x axis. The stationary state of the flow and the stationary electric current are considered. The new quasi-one-dimensional (Q1D) electrodynamical part of a model is developed. The main assumption (besides j{sub z} = 0, E{sub z} = 0) taken in the whole working fluid flow, is j{sub x} = 0. It means that the bending of the electric current pattern in the working fluid, due to the nonmassive electrodes and the presence of the magnetic field, is not explicitly considered. In the frame of the assumption taken, the legitimacy regarding the equation of conservation of charges: div {rvec j} = 0 suggests that the straight electric current pattern in the model should be narrow. In other words, it suggests replacing of a rather complicated electric current pattern in a working fluid by an artificially straight and narrow one in the modeling, promising that it would still be possible to describe the global channel parameters - its electrical output, the influence of the shape and the size of the channel on the generator performance etc.

Bajovic, V.S. [Eindhoven Univ. of Technology (Netherlands)

1995-12-31

23

Full Text Available olli1d17 Clone name olli1d17 Library olli 5' end seq. ID olli1d17 [NBRP] Acc. of 5' end - Tissue nd CLSTF24799 [advanced search] Homology of 5' end xanthine dehydrogenase [Poecilia reticulata] Score of 5' en nd CLSTR20493 [advanced search] Homology of 3' end xanthine dehydrogenase [Poecilia reticulata] Score of 3' en

24

25

Fast estimation of local magnitudes from non-standard Wood-Anderson, short period, seismograms

Directory of Open Access Journals (Sweden)

Full Text Available We propose a method for fast estimation of local magnitudes from seismograms (analog or digital different from the standard Wood-Anderson ones. The method provides a justification of the widely used methods for approximate evaluation of magnitudes from analog seismograms. The method is illustrated through an application to local microseismic data from Baja California, Mexico.

J. J. González

2003-06-01

26

Multichannel Analysis of Surface Waves utilizes a multichannel recording system to estimate near-surface shear (S)-wave velocities from high-frequency Rayleigh waves. A pseudo-2D S-wave velocity (vS) section is constructed by aligning 1D models at the midpoint of each receiver spread and using a spatial interpolation scheme. The horizontal resolution of the section is therefore most influenced by the receiver spread length and the source interval. The receiver spread length sets the theoretical lower limit and any vS structure with its lateral dimension smaller than this length will not be properly resolved in the final vS section. A source interval smaller than the spread length will not improve the horizontal resolution because spatial smearing has already been introduced by the receiver spread. In this paper, we first analyze the horizontal resolution of a pair of synthetic traces. Resolution analysis shows that (1) a pair of traces with a smaller receiver spacing achieves higher horizontal resolution of inverted S-wave velocities but results in a larger relative error; (2) the relative error of the phase velocity at a high frequency is smaller than at a low frequency; and (3) a relative error of the inverted S-wave velocity is affected by the signal-to-noise ratio of data. These results provide us with a guideline to balance the trade-off between receiver spacing (horizontal resolution) and accuracy of the inverted S-wave velocity. We then present a scheme to generate a pseudo-2D S-wave velocity section with high horizontal resolution using multichannel records by inverting high-frequency surface-wave dispersion curves calculated through cross-correlation combined with a phase-shift scanning method. This method chooses only a pair of consecutive traces within a shot gather to calculate a dispersion curve. We finally invert surface-wave dispersion curves of synthetic and real-world data. Inversion results of both synthetic and real-world data demonstrate that inverting high-frequency surface-wave dispersion curves - by a pair of traces through cross-correlation with phase-shift scanning method and with the damped least-square method and the singular-value decomposition technique - can feasibly achieve a reliable pseudo-2D S-wave velocity section with relatively high horizontal resolution. ?? 2008 Elsevier B.V. All rights reserved.

Luo, Y.; Xia, J.; Liu, J.; Xu, Y.; Liu, Q.

2008-01-01

27

Energy Technology Data Exchange (ETDEWEB)

A rather long-period significant later phase which appeared in the seismogram at Kumagaya JMA Observatory during the 1984 Nagano-ken-seibu earthquake is highly important in terms of its resolution and clarity. Studies on the seismogram at Kumagaya JMA Observatory and investigation on the mechanism of the later phase generation have been carried on based on the underground structure, and the generating mechanism of the later phase based on the arranged later phase phenomena and the mechanism of the earthquake commencement are studied. The response amplitude is 1.3 times as compared with the case of principal motion only, and the tremor duration is as large as 3 times due to the existence of the later phase with prominent 6 second cycle in the seismogram at Kumagaya. The later phase consists of Love-wave. Such a later phase can be considered to be a phenomenon which reflects the general underground structure of the area from the epicenter to Kumagaya. The earthquake generating mechanism also relates to the appearance of the later phase, and SH wave emitted from the focus of the earthquake to the north-east direction can be considered to participate in the generation of the later phase. 31 refs., 13 figs.

Koyama, S. (Building Research Inst., Tokyo (Japan)); Seo, K.; Samano, T. (Tokyo Inst. of Technology, Tokyo (Japan). Graduate School)

1992-10-30

28

This research undertook scientific problem inherent in the monitoring of a comprehensive nuclear test ban treaty; establishing confidence that the seismograms from small and moderate-sized events are understood, thus, identifiable. This requires an unders...

T. C. Wallace S. L. Beck

1995-01-01

29

International Nuclear Information System (INIS)

This paper presents experimental evidence of enhancement of second-harmonic generation as a result of the combination of high electromagnetic mode density of states, low group velocity, and spatial phase locking of the fields near the photonic band edge

2000-11-03

30

We derive exact expressions for a number of aging functions that are scaling limits of non-equilibrium correlations, R(tw,tw+t) as tw --> infinity with t/tw --> theta, in the 1D homogenous q-state Potts model for all q with T=0 dynamics following a quench from infinite temperature. One such quantity is (the two-point, two-time correlation function) when n/sqrt(tw) --> z. Exact, closed-form expressions are also obtained when one or more interludes of infinite temperature dynamics occur. Our derivations express the scaling limit via coalescing Brownian paths and a ``Brownian space-time spanning tree,'' which also yields other aging functions, such as the persistence probability of no spin flip at 0 between tw and tw+t.

Fontes, L R; Newman, C M; Stein, D L

2001-01-01

31

Historic analogue seismograms of the large 1956 Amorgos twin earthquakes which occurred in the volcanic arc of the Hellenic Subduction Zone (HSZ) were collected, digitized and reanalyzed to obtain refined estimates of their depth and focal mechanism. In total, 80 records of the events from 29 European stations were collected and, if possible, digitized. In addition, bulletins were searched for instrument parameters required to calculate transfer functions for instrument correction. A grid search based on matching the digitized historic waveforms to complete synthetic seismograms was then carried out to infer optimal estimates for depth and focal mechanism. Owing to incomplete or unreliable information on instrument parameters and frequently occurring technical problems during recording such as writing needles jumping off mechanical recording systems, much less seismograms than collected proved suitable for waveform matching. For the first earthquake, only 7 seismograms from three different stations (STU, GTT, COP) could be used. Nevertheless, the grid search produces stable optimal values for both source depth and focal mechanism. Our results indicate a shallow hypocenter at about 25 km depth. The best-fitting focal mechanism is a SW-NE-trending normal fault dipping either by 30° towards SE or 60° towards NW. This finding is consistent with the local structure of the Santorini-Amorgos graben. For the second earthquake, 4 seismograms from three different stations (JEN, GTT, COP) proved suitable for waveform matching. Whereas it was impossible to obtain meaningful results for the focal mechanism owing to surface wave coda of the first event overlapping body wave phases of the second event, waveform matching and time-frequency analysis point to a considerably deeper hypocenter located within the Wadati-Benioff-zone of the subducting African plate at about 120-160 km depth.

Brüstle, A.; Friederich, W.; Meier, T.; Gross, C.

2013-11-01

32

Macroseismic intensities are the only available data for most historical earthquakes and often represent the unique source of information for crucial events in the definition of seismic hazard. In this paper, we attempt at getting insight into source characteristics by reproducing the observed intensity field. As a test case, we study the source of 1908 Messina Straits earthquake (MW = 7.1), by testing three distinct fault models deduced from the analysis of geodetic data. Starting from the static slip distribution, we develop kinematic source models for the investigated fault and compute full waveform synthetic seismograms in a 1-D structural model, also accounting for anelastic attenuation. Then, we convert both computed peak-ground acceleration (PGA) and peak-ground velocity (PGV) to macroseismic intensity at 100 selected sites, by means of specific empirical relations for the Italian region. By comparing the original data separately with PGA- and PGV-based intensity fields, we discriminate among the tested faults and determine the best values for the investigated kinematic parameters of the source. We also perform a misfit analysis for the best source model, in order to investigate the dependence of the results on the selected parametrization. The results of the analysis indicate that among the tested models, the one characterized by an east-dipping fault, with strike-oriented NS slightly rotated clockwise, better explains the observed macroseismic field of the 1908 Messina Straits earthquake. Besides, the fracture nucleated at the southern end of the fault and ruptured northward, producing considerable directivity effects. This is in agreement with the published results obtained from the investigation of the historical seismograms. We also determine realistic values for the rupture velocity and the rise-time. Our study confirms the great potential of the macroseismic data, demonstrating that they contain enough information to constrain important characteristics of the fault, which can be retrieved by using complex source models and computing complete wavefield. Moreover, we also show that the simultaneous comparison of both PGA- and PGV-based synthetic macroseismic fields with the original intensities provides tighter constraints for discriminating among different source models, with respect to what attainable from each of them.

Convertito, Vincenzo; Pino, Nicola Alessandro

2014-07-01

33

Macroseismic intensities are the only available data for most historical earthquakes and often represent the unique source of information for crucial events in the definition of seismic hazard. In this paper, we attempt at getting insight into source characteristics by reproducing the observed intensity field. As a test case, we study the source of 1908 Messina Straits earthquake (MW = 7.1), by testing three distinct fault models deduced from the analysis of geodetic data. Starting from the static slip distribution, we develop kinematic source models for the investigated fault and compute full waveform synthetic seismograms in a 1-D structural model, also accounting for anelastic attenuation. Then, we convert both computed peak-ground acceleration (PGA) and peak-ground velocity (PGV) to macroseismic intensity at 100 selected sites, by means of specific empirical relations for the Italian region. By comparing the original data separately with PGA- and PGV-based intensity fields, we discriminate among the tested faults and determine the best values for the investigated kinematic parameters of the source. We also perform a misfit analysis for the best source model, in order to investigate the dependence of the results on the selected parametrization. The results of the analysis indicate that among the tested models, the one characterized by an east-dipping fault, with strike-oriented NS slightly rotated clockwise, better explains the observed macroseismic field of the 1908 Messina Straits earthquake. Besides, the fracture nucleated at the southern end of the fault and ruptured northward, producing considerable directivity effects. This is in agreement with the published results obtained from the investigation of the historical seismograms. We also determine realistic values for the rupture velocity and the rise-time. Our study confirms the great potential of the macroseismic data, demonstrating that they contain enough information to constrain important characteristics of the fault, which can be retrieved by using complex source models and computing complete wavefield. Moreover, we also show that the simultaneous comparison of both PGA- and PGV-based synthetic macroseismic fields with the original intensities provides tighter constraints for discriminating among different source models, with respect to what attainable from each of them.

Convertito, Vincenzo; Pino, Nicola Alessandro

2014-04-01

34

Although most researches focus on the lateral heterogeneity of 3D Earth nowadays, a spherically multi-layered model where the parameters depend only on depth still represents a good first order approximation of real Earth. Such 1D models could be used as starting models for seismic tomographic inversion or as background model where the source mechanisms are inverted. The problem of wave propagation in a spherically layered model had been solved theoretically long time ago (Takeuchi and Saito, 1972). The existing computer programs such as Mineos (developed by G. Master, J. Woodhouse and F. Gilbert), Gemini (Friederich and Dalkolmo 1995), DSM (Kawai et. al. 2006) and QSSP (Wang 1999) tackled the computational aspects of the problem. A new simple and fast program for computing the Green's function of a stack of spherical dissipative layers is presented here. The analytical solutions within each homogeneous spherical layer are joined through the continuous boundary conditions and propagated from the center of model up to the level of source depth. Another solution is built by propagating downwardly from the free surface of model to the source level. The final solution is then constructed in frequency domain from the previous two solutions to satisfy the discontinuities of displacements and stresses at the source level which are required by the focal mechanism. The numerical instability in the propagator approach is solved by complementing the matrix propagating with an orthonormalization procedure (Wang 1999). Another unstable difficulty due to the high attenuation in the upper mantle low velocity zone is overcome by switching the bases of solutions from the spherical Bessel functions to the spherical Hankel functions when necessary. We compared the synthetic seismograms obtained from the new program YASEIS with those computed by Gemini and QSSP. In the range of near distances, the synthetics by a reflectivity code for the horizontally layers are also compared with those from YASEIS. Finally the static displacements in the source region are computed by choosing a very small frequency value in YASEIS which is designed for computing the dynamic response, and compared with the results in a homogeneous half-space model (Okada 1992). [1] Friederich, W. and J. Dalkolmo (1995). Complete synthetic seismograms for a spherically symmetric Earth a numerical computation of the Green's function in the frequency domain, Geophys. J. Int., vol. 122, 537-550. [2] Kawai, K., N. Takeuchi, and R.J. Geller (2006). Complete synthetic seismograms up to 2Hz for transversely isotropic spherically symmetric media, Geophys. J. Int., vol. 164, 411-424. [3] Okada, Y. (1992). Internal deformation due to shear and tensile faults in a half space, Bull. Seismol. Soc. Am., vol. 82, no. 2, 1018-1040. [4] Takeuchi, H. and M. Saito (1972). Seismic surface waves, Methods in computational physics, vol. II, 217-295. [5] Wang, R. (1999). A simple orthonormalization method for stable and efficient computation of Green's functions, Bull. Seismol. Soc. Am., vol. 89, no. 3, 733-741.

Ma, Yanlu

2013-04-01

35

Deterministic seismic hazard computations have been done for the Hungarian part of the Pannonian basin within the framework of a cooperation of five countries. Synthetic seismograms have been computed by the modal summation method up to 1 Hz in order to determine the expected maximum displacement (DMAX), velocity (VMAX) and the design ground acceleration (DGA) on a 0.2°× 0.2° grid. DGA values have been estimated from the seismograms by using the standard.This investigation justified the suspicion that a considerable part of seismic hazard of Hungary comes from the seismogenic zones of the neighbouring countries. The highest DGA reaches a value as high as 0.14 g (which corresponds approximately to the VIII intensity degree in the MSK-64 scale). Among the six largest cities of Hungary, three art particularly subject to a high seismic risk. Greater acceleration values have been found for the cities of Szeged and Debrecen than was expected before this study.

Bus, Z.; Szeidovitz, G.; Vaccari, F.

36

Directory of Open Access Journals (Sweden)

Full Text Available The seismogram comparison between the measured and synthetics seismogram has been carried out in observation station of UGM, where the seismograms are excited by earthquakes that occurred at North Sumatra, Sumbawa, Sunda Strait, around North Celebes and PNG. The ray paths from earthquake's hypocenter to UGM give opportunity to understand the earth structure alongside the front area of subduction zone. The calculation of synthetic seismogram needs input in the form of earth model, the Centroid Moment Tensor (CMT solution of the earthquake and location of observation station, as well as the relevant date file response of the observation station. Waveform comparison and fitting at surface wave indicate that speed's anomalies in the lithosphere have negative character in front area of subducted zone, but become positive for northern area of subduction zone. By paying attention to waveform of Love surface wave, it is obtained, that this waveform are sensitive to the change of earth crust thickness, while Rayleigh waveform is not sensitive. Heterogeneity is not only occurred in the lithosphere, but also in deeper earth layers, until Core Mantle Boundary (CMB. Different corrections are needed to make the fitting at S secondary wave, but also at depth wave and its repetitions. The result of this research shows that the research area, which is located in the front of subduction zone has anomalies at S speed of at deeper earth layers which than the lithosphere. The earth structure as the result of this research differs from the other seismological results, where they used the methods, which are based on inversion of arrival time data of body wave and dispersion analysis on surface wave.

Bagus Jaya Santosa

2008-11-01

37

We have developed algorithms for modelling seismic waveforms to constrain regional Earth structure. The seismogram is represented as a sum of locked-mode travelling waves in a layered medium. This representation is convenient as it allows us to model structures with slowly varying heterogeneity and to construct differential seismograms. Describes the techniques we have implemented that enable us to compute synthetic and differential seismograms in an efficient and stable manner. The computational methods are sufficiently rapid that many modes can be included and in some cases the entire seismogram may be modified. These algorithms are applied to model a set of seismograms of southern Mexican earthquakes recorded in northern Mexico. The frequency bandwidth of these data is centred at 0.067 Hz and we demonstrate that even at these relatively high frequencies, many features of the seismogram can be successfully modelled. Our results suggest that the structure within the recording array in northern Mexico is resolvably different from that to the south. We find that the average shear velocity of the lower lithosphere of southern Mexico is very low, approximately 4.3 km s-1. If the low-velocity region is confined to the Trans Mexican Volcanic Belt, the shear velocities between 20-80 km depth are approximately 3.3 km s-1. This may be correlated with partial melt and is consistent with the active volcanism and high heat flow found in the region. -Authors

Gomberg, J. S.; Masters, T. G.

1988-01-01

38

Reservoir prediction with its unique role in oil and gas fields is constantly facing new challenges, such as high-resolution seismic data and fast-accurate impedance inversion are needed. Generally, conventional methods used to enhance the resolution of seismic data, for example the spectral whitening, sometimes called balancing or broadening, is hard to yield valuable results as the seismic wavelets change during traveling subsurface. Besides, impedance inversion used in reservoir such as acoustic impedance inversion (AII) also confronts problem—low computational efficiency when more geological and geophysical parameters are taken into consideration in the modeling inversion. Based on these questions, in this study, a joint approach is presented. The first approach is the variable wavelet model of seismograms (VWMS), which is carried out by a series of processes such as time partition and frequency domain processing, to enhance the resolution of the seismic traces. Another approach that can improve the computational efficiency of the AII is the acoustic impedance inversion based wavelet edge analysis and modeling (AII-WEAM). In this approach, the algorithms of the AII were replaced by the modified very fast simulated annealing (MVFSA), to improve the inversed speed. By using a gas reservoir predicting example, we show that the joint approaches produce results that are feasible and reliable after comparing with the well data. Hence, these joint approaches have great potential to be the next-generation tools for reservoir description and prediction.

Xie, Yujiang; Liu, Gao

2014-02-01

39

Energy Technology Data Exchange (ETDEWEB)

The authors present the results of moment tensor inversions using regional seismograms recorded during the 1991-1992 PASSCAL passive seismic experiment on the Tibetan Plateau. Using data recorded over a one-year period, they estimate the source mechanisms for 38 earthquakes within and near the Tibetan Plateau with moment-magnitudes (M{sub w}) ranging from 3.8 to 5.0. With only one exception, all the events within the Plateau, but away from the Plateau boundary, indicate either strike-slip or extensional faulting, a result consistent with previous studies. Three-fourths of all the events occurred at depths less than 10 km, and all but two at depths less than 15 km. Several events, located near the southeastern section of the Plateau, exhibit an unusual m{sub b}-M{sub w} difference of approximately one magnitude unit. 19 refs., 3 figs.

Randall, G.E.; Owens, T.J. [Univ. of South Carolina, Columbia, SC (United States); Ammon, C.J. [St. Louis Univ., MO (United States)

1995-07-01

40

High-frequency Born synthetic seismograms based on coupled normal modes

High-frequency and full waveform synthetic seismograms on a 3-D laterally heterogeneous earth model are simulated using the theory of coupled normal modes. The set of coupled integral equations that describe the 3-D response are simplified into a set of uncoupled integral equations by using the Born approximation to calculate scattered wavefields and the pure-path approximation to modulate the phase of incident and scattered wavefields. This depends upon a decomposition of the aspherical structure into smooth and rough components. The uncoupled integral equations are discretized and solved in the frequency domain, and time domain results are obtained by inverse Fourier transform. Examples show the utility of the normal mode approach to synthesize the seismic wavefields resulting from interaction with a combination of rough and smooth structural heterogeneities. This approach is applied to an ~4 Hz shallow crustal wave propagation around the site of the San Andreas Fault Observatory at Depth (SAFOD). ?? The Author Geophysical Journal International ?? 2011 RAS.

Pollitz, F.

2011-01-01

41

The May 18, 1998 Indian Nuclear Test Seismograms at station NIL

Energy Technology Data Exchange (ETDEWEB)

The last underground nuclear tests were conducted by India and Pakistan in May 1998. Although the Comprehensive Test Ban Treaty has not entered force, an International Monitoring System (IMS), established by the treaty is nearing completion. This system includes 170 seismic stations, a number of them originally established by IRIS. The station IRIS station NIL (Nilore, Pakistan) is close to a planned IMS primary station and recorded some very interesting seismograms from the May 18, 1998 Indian test. We carefully calibrated the path to NIL using a prior Mw 4.4 that occurred on April 4, 1995 about 110 km north of the Indian test site. We used joint epicentral location techniques along with teleseismic P waves and regional surface waves to fix the epicenter, depth, mechanism and moment of this event. From these we obtained a velocity model for the path to NIL and created explosion synthetic seismograms to compare with the data. Interestingly the observed Rayleigh waves are reversed, consistent with an implosion rather than an explosion source. The preferred explanation is that the explosion released tectonic stress near the source region, which can be modeled as a thrust earthquake of approximate Mw 4.0 plus a pure explosion. This tectonic release is sufficient to completely dominate the Rayleigh waves and produce the observed signal (Walter et al. 2005). We also examined the explosion at high frequencies of 6 6-8 Hz where many studies have shown that relative P/S amplitudes can discriminate explosions from a background of earthquakes (Rodgers and Walter, 2002). Comparing with the April 4 1995 earthquake we see the classic difference of relatively large P/S values for the explosion compared to the earthquakes despite the complication of the large tectonic release during the explosion.

Walter, W R; Rodgers, A J; Bowers, D; Selby, N

2005-04-11

42

1-D neutronics optimization design for ITER CH HCSB TBM

International Nuclear Information System (INIS)

The neutronics problem of the TBM module design connects closely with TBM's other problems, such as, tritium generation, thermo-hydraulic, safety, etc. An exact neutronics calculation for the TBM module is very important. Based on the 1-D calculation model given in the CH HCSB TBM design, a better 1-D neutronics optimization has been performed using the ONEDANT code with related database. (authors)

2006-09-01

43

Coal-seismic, desktop computer programs in BASIC; Part 7, Display and compute shear-pair seismograms

Processing of geophysical data taken with the U.S. Geological Survey's coal-seismic system is done with a desk-top, stand-alone computer. Programs for this computer are written in the extended BASIC language utilized by the Tektronix 4051 Graphic System. This report discusses and presents five computer pro grams used to display and compute shear-pair seismograms.

Hasbrouck, W. P.

1983-01-01

44

Directory of Open Access Journals (Sweden)

Full Text Available In this research the S speed structure is investigated by seismogram analysis of Washington's earthquake, C022801L using data of TUC station, Tucson, Arizona, U.S.A. The seismogram comparison between the observed and the synthetic seismogram is conducted in time domain and three components simultaneously. The initially input for the calculation of synthetic seismogram is earth model of PREMAN and CMT solution from the earthquake. A low-pass Butterworth filter with corner frequency of 20 mHz is convolved to observed and synthetic seismogram. Waveform comparison shows a real deviation when travel time and waveform of some wave phase are compared, namely on S wave, surface wave of Love and Rayleigh and wave ScS and ScS-2. This research shows, how sensitive the waveform is to the earth model, better than the method of travel time or the dispersion analysis. Research hereinafter is addressed to finish the found discrepancies at S wave, surface wave of Love and Rayleigh and ScS and ScS-2 wave, in observation station TUC. To obtain the seismogram fitting, correction for S speed structure in earth model is needed, that are changes of earth crust thickness, the speed model of ? in upper mantle covering the speed gradient of ?h and value of zeroeth order coefficient for the ?h and ?v, for accomplishing the discrepancies at surface wave of Love and Rayleigh. Further correction on S speed is conducted to accomplish the deviation at S wave at earth layering systems from Upper Mantle up to a 630 km depth. Mean while for the ScS and ScS-2 wave phase the correction is carried out on S speed in the earth layers up to CMB. Fitting Seismogram is obtained at waveform of various wave phases that is S wave, surface wave of Love and Rayleigh and ScS, ScS-2 wave, either on travel time or especially also at oscillation number in Love wave. This result indicates that the anisotropy is occurred not only in upper mantle but till deeper earth layers, till CMB.

Bagus Jaya Santosa

2005-11-01

45

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite a high degree of conservation, subtle but important differences exist between the CD1d antigen presentation pathways of humans and mice. These differences may account for the minimal success of natural killer T (NKT) cell-based antitumor therapies in human clinical trials, which contrast strongly with the powerful antitumor effects in conventional mouse models. To develop an accurate model for in vivo human CD1d (hCD1d) antigen presentation, we have generated a hCD1d knock-in (hCD1d-K...

Wen, Xiangshu; Rao, Ping; Carren?o, Leandro J.; Kim, Seil; Lawrenczyk, Agnieszka; Porcelli, Steven A.; Cresswell, Peter; Yuan, Weiming

2013-01-01

46

MMT. 1-D Radionuclide Ground Water Transport

Energy Technology Data Exchange (ETDEWEB)

MMT solves the one-dimensional equation for transport of radionuclides in a ground-water system with uniform velocity and transport properties. The purpose of the code is to evaluate radionuclide release rates from the site subsystem. MMT treats convective transport, sorption-desorption effects, and hydrodynamic dispersion. Sorption and desorption of radionuclides are taken into account by application of retardation factors which are spatially uniform and derived from bulk rock properties and average geochemical data. Dispersion along the direction of flow (forward and backward) is also taken into account. Because the code solves only the one-dimensional transport equation, dispersion transverse to the direction of flow is not evaluated. A discrete parcel random walk (DPRW) approach is used to solve the coupled equations. This numerical technique is inherently stable and minimizes computational errors that lead to apparent mass nonconservation. MMT is a set of three programs which are run sequentially. The first program, MMT1D, utilizes flow and radionuclide input to generate the raw radionuclide release rate output in terms of the frequency at which parcels pass the specified release point and the calculated weights of these parcels. The second program, PLTCVT, is a postprocessor which filters and smooths the MMT1D output to reduce the statistical fluctuation. PLTCVT uses a variable-window, moving-average filter algorithm to smooth the raw results. The smoothed output from PLTCVT consists of separate, smoothed output files for each nuclide under consideration. The third program, MERGE, merges the separate release files generated by PLTCVT into a single output file. This merged output file may be used directly by a biosphere transport or dose assessment code as radionuclide release rate input data.

Golis, M.J. [Battelle Memorial Institute, Columbus, OH (United States)

1984-05-01

47

Wavelet transform analysis of transient signals: the seismogram and the electrocardiogram

Energy Technology Data Exchange (ETDEWEB)

In this dissertation I quantitatively demonstrate how the wavelet transform can be an effective mathematical tool for the analysis of transient signals. The two key signal processing applications of the wavelet transform, namely feature identification and representation (i.e., compression), are shown by solving important problems involving the seismogram and the electrocardiogram. The seismic feature identification problem involved locating in time the P and S phase arrivals. Locating these arrivals accurately (particularly the S phase) has been a constant issue in seismic signal processing. In Chapter 3, I show that the wavelet transform can be used to locate both the P as well as the S phase using only information from single station three-component seismograms. This is accomplished by using the basis function (wave-let) of the wavelet transform as a matching filter and by processing information across scales of the wavelet domain decomposition. The `pick` time results are quite promising as compared to analyst picks. The representation application involved the compression of the electrocardiogram which is a recording of the electrical activity of the heart. Compression of the electrocardiogram is an important problem in biomedical signal processing due to transmission and storage limitations. In Chapter 4, I develop an electrocardiogram compression method that applies vector quantization to the wavelet transform coefficients. The best compression results were obtained by using orthogonal wavelets, due to their ability to represent a signal efficiently. Throughout this thesis the importance of choosing wavelets based on the problem at hand is stressed. In Chapter 5, I introduce a wavelet design method that uses linear prediction in order to design wavelets that are geared to the signal or feature being analyzed. The use of these designed wavelets in a test feature identification application led to positive results. The methods developed in this thesis; the feature identification methods of Chapter 3, the compression methods of Chapter 4, as well as the wavelet design methods of Chapter 5, are general enough to be easily applied to other transient signals.

Anant, K.S.

1997-06-01

48

In this paper we present two new procedures for automatic detection and picking of P-wave arrivals. The first involves the application of kurtosis and skewness on the vector magnitude of three component seismograms. Customarily, P-wave arrival detection techniques use vertical component seismogram which is appropriate only for teleseismic events. The inherent weakness of those methods stems from the fact that the energy from P-wave is distributed among horizontal and vertical recording channels. Our procedure, however, uses the vector magnitude which accommodates all components. The results show that this procedure would be useful for detecting/picking of P-arrivals from local and regional earthquakes and man-made explosions. The second procedure introduces a new method called "Ratios in Higher Order Statistics (RHOS)." Unlike commonly used techniques that involve derivatives, this technique employs ratios of adjacent kurtosis and skewness values to improve the accuracy of the detection of the P onset. RHOS c...

Dugda, Mulugeta

2010-01-01

49

Digital Repository Infrastructure Vision for European Research (DRIVER)

The basic purpose of the paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One of examples of such kind of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). We propose here a discrete stochastic model for possible solution of a problem of strong EQ's forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is...

Yulmetyev, Renat; Gafarov, Fail; Ha?nggi, Peter; Nigmatullin, Raoul; Kayumov, Shamil

2001-01-01

50

Intermittency and clustering in the 1-D lattice gas model

International Nuclear Information System (INIS)

We construct generating functions of the scaled factorial moments of the distribution of the particles and links (two neighbouring particles) in the 1-D statistical system for variable bin size. The results show intermittent-like behaviour. We compare the intermittency signal for particles and links and discuss a possible influence of the clustering in hadronization on the size of fluctuations. (orig.)

1991-01-01

51

Two extensions of 1D Toda hierarchy

The extended Toda hierarchy of Carlet, Dubrovin and Zhang is reconsidered in the light of a 2+1D extension of the 1D Toda hierarchy constructed by Ogawa. These two extensions of the 1D Toda hierarchy turn out to have a very similar structure, and the former may be thought of as a kind of dimensional reduction of the latter. In particular, this explains an origin of the mysterious structure of the bilinear formalism proposed by Milanov.

Takasaki, Kanehisa

2010-01-01

52

The collision of plates at subduction zones yields the potential for disastrous earthquakes, yet the processes that lead up to these events are still largely unclear and make them difficult to forecast. Recent advancements in seismic monitoring has revealed subtle ground vibrations termed tectonic tremor that occur as long-lived swarms of narrow bandwidth activity, different from local earthquakes of comparable amplitude that create brief signals of broader, higher frequency. The close proximity of detected tremor events to the lower edge of the seismogenic zone along the subduction interface suggests a potential triggering relationship between tremor and megathrust earthquakes. Most tremor catalogs are constructed with detection methods that involve an exhausting download of years of high sample rate seismic data, as well as large computation power to process the large data volume and identify temporal patterns of tremor activity. We have developed a tremor detection method that employs the underutilized Quality Analysis Control Kit (QuACK), originally built to analyze station performance and identify instrument problems across the many seismic networks that contribute data to one of the largest seismogram databases in the world (IRIS DMC). The QuACK dataset stores seismogram amplitudes at a wide range of frequencies calculated every hour since 2005 for most stations achieved in the IRIS DMC. Such a preprocessed dataset is advantageous considering several tremor detection techniques use hourly seismic amplitudes in the frequency band where tremor is most active (2-5 Hz) to characterize the time history of tremor. Yet these previous detection techniques have relied on downloading years of 40-100 sample-per-second data to make the calculations, which typically takes several days on a 36-node high-performance cluster to calculate the amplitude variations for a single station. Processing times are even longer for a recently developed detection algorithm that utilize the ratio of amplitudes between tremor frequencies and those of local earthquakes (10-15 Hz) and surface waves (0.02-0.1 Hz). Using the QuACK dataset, we can make the more advanced calculations in a fraction of the time. This method works well to quickly detect tremor in the Cascadia region by finding similar times of increased tremor activity when comparing across a variety of stations within a 100km radius of a reference station. We confirm the legitimacy of this method by demonstrating comparable results to several previously developed tremor detection techniques despite a much shorter processing time. The rapid processing time has allowed us to refine the detection algorithm by seeking more optimal frequency bands by comparing results from our technique and others, using several stations across the Cascadia subduction zone. As we move forward, we will apply the method to other subduction zones, and ultimately to the vast set of seismic data stored at the IRIS DMC for which tremor has not been previously investigated.

Rasor, B. A.; Brudzinski, M. R.

2013-12-01

53

Study of East Kazakh explosions and propagation in Central Asia using regional Chinese seismograms

International Nuclear Information System (INIS)

Seismograms recorded at the Urumchi Station in northwestern China from eleven Asian events including seven presumed East Kazakh nuclear explosions were analyzed. Group velocity dispersion curves of Rayleigh waves were measured at short periods on paths through basin and fold belt terrains. At 10 sec period, the velocities on paths over sedimentary basins are 25% slower than velocities on paths over fold belts. We interpret those differences in velocities to be due to the great thicknesses of sedimentary deposits in basin terrains. Epicentral locations were estimated using differential travel times between P/sub n/ and L/sub g/ and particle motions of Rayleigh waves measured on a single three-component record. For a 1000 km path, the location errors (one standad deviation) are about +-125 km in azimuth and +-30 km in distance. In addition, systematic errors due to structural effects on surface-wave paths and on velocities of regional phases are shown to seriously bias location estimates of several events. We applied a differential phase method to Rayleigh waves from the East Kazakh explosions and found that signals of all events are in-phase with signals from the reference event on 10/12/80. Thus, there is no evidence for phase reversals or shifts at the Urumchi station in the frequency band where signal to noise ratio is good and where assumptions of the method are valid. Seismic moments of explosions were estimated using models of explosion sources with associated tectonic release. Observed amplitude spectra of Rayleigh waves were richer in high frequencies than predicted by the model. This could be a source effect related to source medium excitation (i.e., Green's functions) or a path effect caused by energy focussing and/or amplifications. We discuss the potential bias in the estimates of moment due to assumptions/limitations. 24 references, 16 figures, 6 tables

1984-01-01

54

Development of earthquake early warning system using real time signal of broadband seismogram

Energy Technology Data Exchange (ETDEWEB)

Earthquake pose serious threat of live and properties for urban area near subduction zone offshore and active fault on land. Jakarta and Bandung is an example of big city that no system of Earthquake early warning (EEW) event very high urbanization, and has many important infra structure in the area. The capital city is potentially high risk ground shaking. EEW can be usefull tool for reducing earthquake hazard, if spatial relation between cities and earthquake source is favorable for such warning and their citizens are properly trained to response early warning message. An EEW and rapid response system can provide the critical information needed to minimized lost of live and property and direct rescue. Earthquake ground shaking with magnitude M>6.0 from zone of Megathrust, southern of West Java should potentially damage in the area of west java especially Bandung and Jakarta City. This research development of EEW parameter such as amplitude displacement (Pd), rapid magnitude determination (M) and Peak ground Velocity (PGV). We explore the practical approach to EEW with the use of Broadband seismogram signal. Time effective EEW which epicenter from megathrust zone has potential to provide EEW in the area of west java such as Jakarta first ground shaking more or less 60 second later and strong shaking 118 second after EEW Alarm on CISI Station. EEW notification at potentially damage in the area of west java can be predicted from the characteristic of Pd > 0.5 cm, M> 6 and PGV > 10 cm/sec. GIS as a tool for presentation of hazard mapping in the affected area.

Gunawan, Hendar; Puspito, Nanang T.; Ibrahim, Gunawan; Harjadi, Prih [Badan Meteorologi Klimatologi dan Geofisika, Jl. Angkasa I No 2 Jakarta 10720 Indonesia Institut Technologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2012-06-20

55

Development of earthquake early warning system using real time signal of broadband seismogram

Earthquake pose serious threat of live and properties for urban area near subduction zone offshore and active fault on land. Jakarta and Bandung is an example of big city that no system of Earthquake early warning (EEW) event very high urbanization, and has many important infra structure in the area. The capital city is potentially high risk ground shaking. EEW can be usefull tool for reducing earthquake hazard, if spatial relation between cities and earthquake source is favorable for such warning and their citizens are properly trained to response early warning message. An EEW and rapid response system can provide the critical information needed to minimized lost of live and property and direct rescue. Earthquake ground shaking with magnitude M>6.0 from zone of Megathrust, southern of West Java should potentially damage in the area of west java especially Bandung and Jakarta City. This research development of EEW parameter such as amplitude displacement (Pd), rapid magnitude determination (M) and Peak ground Velocity (PGV). We explore the practical approach to EEW with the use of Broadband seismogram signal. Time effective EEW which epicenter from megathrust zone has potential to provide EEW in the area of west java such as Jakarta first ground shaking more or less 60 second later and strong shaking 118 second after EEW Alarm on CISI Station. EEW notification at potentially damage in the area of west java can be predicted from the characteristic of Pd > 0.5 cm, M> 6 and PGV > 10 cm/sec. GIS as a tool for presentation of hazard mapping in the affected area.

Gunawan, Hendar; Puspito, Nanang T.; Ibrahim, Gunawan; Harjadi, Prih

2012-06-01

56

Digital Repository Infrastructure Vision for European Research (DRIVER)

The hybridization between two numerical methods, the 1D Wave Concept Iterative Procedure (WCIP) and the 2D Finite Element Method (FEM), is introduced. Preliminary numerical results are also presented.

2012-01-01

57

Social exploration of 1D games

DEFF Research Database (Denmark)

In this paper the apparently meaningless concept of a 1 dimensional computer game is explored, via netnography. A small number of games was designed and implemented, in close contact with online communities of players and developers, providing evidence that 1 dimension is enough to produce interesting gameplay, to allow for level design and even to leave room for artistic considerations on 1D rendering. General techniques to re-design classic 2D games into 1D are also emerging from this exploration.

Valente, Andrea; Marchetti, Emanuela

2013-01-01

58

Natural Lipid Ligands Associated with Human CD1d Targeted to Different Subcellular Compartments

Digital Repository Infrastructure Vision for European Research (DRIVER)

CD1d is an MHC class I-like membrane glycoprotein that presents lipid antigens to NKT cells. Despite intensive biochemical, genetic and structural studies, the endogenous lipids associated with CD1d remain poorly defined because of the biochemical challenges posed by their hydrophobic nature. Here we report the generation of a protease-cleavable CD1d variant with a similar trafficking pattern to wild-type CD1d that can be purified in the absence of detergent and allows the characterization of...

Yuan, Weiming; Kang, Suk-jo; Evans, James E.; Cresswell, Peter

2009-01-01

59

International Nuclear Information System (INIS)

Seismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100-120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques. In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the 20. century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) - both of which are the strongest ever recorded instrumentally in their respective countries - and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismo-genic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Appennines. (author)

2011-06-01

60

First Observation of Upsilon(1D) States

The CLEO III experiment has recently accumulated a large statistics sample of 4.73 x 10^6 Upsilon(3S) decays. We present the first evidence for the production of the triplet Upsilon(1D) states in the four-photon cascade, Upslion(3S) -> gamma chi_b(2P), chi_b(2P) -> gamma Upsilon(1D), Upsilon(1D) -> gamma chi_b(1P), chi_b(1P) -> gamma Upsilon(1S), followed by the Upsilon(1S) annihilation to e+ e- or mu+ mu-. The signal has a significance of 9.7 standard deviations. The measured product branching ratio for these five decays, (3.3 +- 0.6 +- 0.5) x 10^{-5}, is consistent with the theoretical estimates. We see a 6.8 standard deviation signal for a state with a mass of 10162.2 +- 1.6 MeV/c^2, consistent with the Upsilon(1D_2) assignment. We also present improved measurements of the Upsilon(3S) -> pi0 pi0 Upsilon(1S) branching ratio and the associated di-pion mass distribution.

Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; McGee, S; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Sun, W M; Weinstein, A J; Mahapatra, R; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G T; Vogel, H; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, David G; Drell, P S; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Mistry, N B; Nordberg, E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Thayer, J G; Urner, D; Viehhauser, G; Warburton, A; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stöck, H; Yelton, J; Brandenburg, G; Kim, D Y J; Wilson, R; Benslama, K; Eisenstein, B I; Ernst, J; Gollin, G D; Hans, R M; Karliner, I; Lowrey, N; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Ammar, R; Besson, D; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Li, S Z; Poling, R A; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ahmed, S; Alam, M S; Jian, L; Saleem, M; Wappler, F; Eckhart, E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pedlar, T K; Thayer, J B; Von Törne, E; Wilksen, T; Zoeller, M M; Muramatsu, H; Richichi, S J; Severini, H; Skubic, P L; Dytman, S A; Müller, J A; Nam, S; Savinov, V; Chen, S; Hinson, J W; Lee, J; Miller, D H; Pavlunin, V; Shibata, E I; Shipsey, I P J; Cronin-Hennessy, D; Lyon, A L; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Maravin, Y; Stroynowski, R; Artuso, M; Boulahouache, C; Bukin, K; Dambasuren, E; Khroustalev, K; Mountain, R; Nandakumar, R; Skwarnicki, T; Stone, S; Wang, J C; Mahmood, A H

2002-01-01

61

Digital Repository Infrastructure Vision for European Research (DRIVER)

An hybridization between two numerical methods, the 1d Wave Concept Iterative Procedure (WCIP) and the 2d Finite Element Method (FEM), is developed. Using two examples, comparisons are provided between the new hybrid method and an analytic solution, when available, or the WCIP alone.

2012-01-01

62

Simulating high-frequency seismograms in complicated media: A spectral approach

International Nuclear Information System (INIS)

The main attraction of using a spectral method instead of a conventional finite difference or finite element technique for full-wavefield forward modeling in elastic media is the increased accuracy of a spectral approximation. While a finite difference method accurate to second order typically requires 8 to 10 computational grid points to resolve the smallest wavelengths on a 1-D grid, a spectral method that approximates the wavefield by trignometric functions theoretically requires only 2 grid points per minimum wavelength and produces no numerical dispersion from the spatial discretization. The resultant savings in computer memory, which is very significant in 2 and 3 dimensions, allows for larger scale and/or higher frequency simulations

1993-11-01

63

The basic purpose of the paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One of examples of such kind of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). We propose here a discrete stochastic model for possible solution of a problem of strong EQ's forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is performed by two independent methods: with the use of statistical theory of discrete non-Markov stochastic processes (Phys. Rev. E62,6178 (2000)) and the local Hurst exponent. Time recordings of seismic signals of the first four dynamic orthogonal collective variables, six various plane of phase portrait of four dimensional phase space of orthogonal variables and the local Hurst exponent have been calculated for the dynamic analysis of the earth states. The approaches, permitting to obtain an algorithm of strong EQ's forecasting and to di...

Yulmetyev, R M; Hänggi, P; Nigmatullin, R; Kayumov, S; Yulmetyev, Renat; Gafarov, Fail; Nigmatullin, Raoul; Kayumov, Shamil

2001-01-01

64

International Nuclear Information System (INIS)

Radiative instabilities that can develop in plasmas subjected to external heating and radiative cooling are of great importance in edge plasmas of tokamaks and stellarators. They will be analyzed in this paper on the basis of the 1d heat conduction equation. Bifurcation and time evolution of temperature profiles along magnetic field lines between two target plates have been reported. The simple model functions used there are applied here together with methods proved to be useful in nonlinear theories of dynamical systems in order to investigate stable, unstable and chaotic solutions of the 1d heat conduction equation. We consider the model of a radiative plasma with periodically (period ?) injected impurities. In order to show the basic mechanism we discuss at first the time-dependent problem which leads to an equation that can be integrated piecewise exactly analogous to the equation of motion for the periodically kicked rotator. Solution and Lyapunov stability analysis of that one-dimensional radiative map show the existence of stable and unstable solutions. Calculating attractors and Lyapunov exponents in dependence of parameters like power input or period ? shows the appearance of periodical solutions followed by period doubling and finally resulting in chaos in the radiative plasma. Second, we consider 1d and time-dependent problems by calculating profiles and attractors. Enhancing the period ? starting from ? = 0 (stationary problem) rediscovers the known routes to chaos in spatial extension like period doubling or intermittence. (orig.)

2001-09-10

65

Modelling fibrinolysis: 1D continuum models.

Fibrinolysis is the enzymatic degradation of the fibrin mesh that stabilizes blood clots. Experiments have shown that coarse clots made of thick fibres sometimes lyse more quickly than fine clots made of thin fibres, despite the fact that individual thick fibres lyse more slowly than individual thin fibres. This paper aims at using a 1D continuum reaction-diffusion model of fibrinolysis to elucidate the mechanism by which coarse clots lyse more quickly than fine clots. Reaction-diffusion models have been the standard tool for investigating fibrinolysis, and have been successful in capturing the wave-like behaviour of lysis seen in experiments. These previous models treat the distribution of fibrin within a clot as homogeneous, and therefore cannot be used directly to study the lysis of fine and coarse clots. In our model, we include a spatially heterogeneous fibrin concentration, as well as a more accurate description of the role of fibrin as a cofactor in the activation of the lytic enzyme. Our model predicts spatio-temporal protein distributions in reasonable quantitative agreement with experimental data. The model also predicts observed behaviour such as a front of lysis moving through the clot with an accumulation of lytic proteins at the front. In spite of the model improvements, however, we find that 1D continuum models are unable to accurately describe the observed differences in lysis behaviour between fine and coarse clots. Features of the problems that lead to the inaccuracy of 1D continuum models are discussed. We conclude that higher-dimensional, multiscale models are required to investigate the effect of clot structure on lysis behaviour. PMID:23220467

Bannish, Brittany E; Keener, James P; Woodbury, Michael; Weisel, John W; Fogelson, Aaron L

2014-03-01

66

1D localisation and the symmetric group

Energy Technology Data Exchange (ETDEWEB)

Earlier investigations making use of a density matrix formalism to study the average resistance of a disordered solid are extended in the 1D case to calculate moments of the resistance within a diagonal-disorder model. Application of the symmetric group greatly simplifies the problem, reducing matrices from of order 2 /SUP 2N/ to of order 2N + 1 for the Nth moment. The symmetry-reduced matrix enables a transparent discussion to be made of the analytic properties of the mean conductance which is shown to have a number of remarkable properties. Finally, some analytic results are presented in various limiting cases and compared with earlier work.

Pendry, J.B.

1982-08-20

67

A 1-D dusty plasma photonic crystal

Energy Technology Data Exchange (ETDEWEB)

It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 ?m to about 1350 ?m, depending on the rf power fed into the discharge.

Mitu, M. L.; Tico?, C. M. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Toader, D.; Banu, N.; Scurtu, A. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Department of Physics, University of Bucharest, 077125 Bucharest (Romania)

2013-09-21

68

Beam and storage ring parameters have to meet a number of stringent conditions before circulating three-dimensional crystalline beams can be obtained. Existing storage rings violate at least one of these conditions. The remarkable exception is the very low-energy ring PALLAS with 'radio frequency focusing', which apparently abides by the full set of conditions, and where 3D-ordering has indeed been realized. However 1D-ordering, - particles lining up in a 'string of non-overtaking links' - has been observed in several storage rings with electron cooling, even though the above conditions on the classical plasma parameter as well as on the lattice periodicity are largely violated. In this paper, we discuss conditions for 1D- ordering, including space-charge limits, instabilities and cooling requirements. We conclude that densities of some 10**4 ions/m may be possible; about 100 times more than those obtained in present experiments. Such dense strings are of practical interest for precision measurements of ion p...

Katayama, T

2004-01-01

69

Linked cluster expansion and 1/d expansions for classical spin systems

International Nuclear Information System (INIS)

We consider 1/d expansions for classical spin systems based on the vertex renormalized linked cluster expansion (LCE). The free multiplicities of the LCE graphs on a hypercubic lattice in an arbitrary dimension d are calculated using generating functions. The technique is applied to the Ising model and to a two-component classical lattice gas corresponding to an extended Hubbard model at half filling in the zero-bandwidth limit. We use a resummation of the LCE to generate 1/d expansions for the equation of state and for the critical temperature. The method, which is rather general and applicable to a wide range of models, proves convenient for calculating asymptotic power series expansions in 1/d. The vertex renormalized expansion is shown to break down at low temperature in higher order approximations, barring attempts to construct simple approximations that are both self-consistent and exact to some finite order in 1/d

2001-01-01

70

Linked cluster expansion and 1/d expansions for classical spin systems

Energy Technology Data Exchange (ETDEWEB)

We consider 1/d expansions for classical spin systems based on the vertex renormalized linked cluster expansion (LCE). The free multiplicities of the LCE graphs on a hypercubic lattice in an arbitrary dimension d are calculated using generating functions. The technique is applied to the Ising model and to a two-component classical lattice gas corresponding to an extended Hubbard model at half filling in the zero-bandwidth limit. We use a resummation of the LCE to generate 1/d expansions for the equation of state and for the critical temperature. The method, which is rather general and applicable to a wide range of models, proves convenient for calculating asymptotic power series expansions in 1/d. The vertex renormalized expansion is shown to break down at low temperature in higher order approximations, barring attempts to construct simple approximations that are both self-consistent and exact to some finite order in 1/d.

Halvorsen, E.; Bartkowiak, M.

2001-01-01

71

Directory of Open Access Journals (Sweden)

Full Text Available Source parameters for three majo earthquakes in the East African rift are re-computed from historical seismograms and bulletins. The main shock and the largest foreshock of the August 25, 1906 earthquake sequence in the main Ethiopian rift are re-located on the eastern shoulder of the rift segment.The magnitude of the main shock is estimated to be 6.5 (Mw from spectral analysis. The December 13, 1910 earthquake in the Rukwa rift (Western Tanzania indicated a significant strike-slip component from teleseismcs body-waveform inversion for fault mechanism and seismic moment. The January 6, 1928 earthquake in the Gregory rift (Kenya showed a multiple rupture process and unusually long duration for a size of 6.6(Mw. The May 20, 1990 earthquake in Southern Sudan, mentioned merely for the sake of comparison, is the largest of all instrumentally recorded events in the East African rift system. Despite the fact that the mode of deformation in the continental rift is predominantly of extensional nature, the three largest earthquakes known to occur in the circum-Tanzanian craton have shallow focal depths and significant strike-slip component in their fault mechanisms. This and similar works will enrich the database for seismic hazard assessment in East Africa.

O. Kulhánek

2000-06-01

72

Processing of data taken with the U.S. Geological Survey's coal-seismic system is done with a desktop, stand-alone computer. Programs for this computer are written in the extended BASIC language used by the Tektronix 4051 Graphic System. This report presents computer programs to perform X-square/T-square analyses and to plot normal moveout lines on a seismogram overlay.

Hasbrouck, W. P.

1983-01-01

73

1-D hybrid code for FRM dynamics

International Nuclear Information System (INIS)

A 1-D radial hybrid code has been written to study the start-up of the FRM via neutral-beam injection. This code, named FROST (Field Reversed One-dimensional STart-up), models the plasma as azimuthal symmetric with no axial dependence. A multi-group method in energy and canonical angular momentum describes the large-orbit ions from the beam. This method is designed to be more efficient than those employing particle tracking, since the characteristic timescale of the simulation is the ion slowing down time, rather than the much shorter cyclotron period. A time-differentiated Grad-Shafranov equation couples the ion current to massless fluid equations describing electrons and low energy ions. Flux coordinates are used in this fluid model, in preference to an Eulerian framework, so that coupling of plasma at the two different radii of a closed flux surface may be treated with ease. Since a fluid treatment for electrons is invalid near a field null, a separate model for the electron current has been included for this region, a unique feature. Results of simulation of injection into a 2XIIB-like plasma are discussed. Electron currents are found to retard, but not prevent reversal of the magnetic field at the plasma center

1985-04-09

74

Point Charge Forces in 1D Model

The Point Charge Forces in One-Dimension model investigates the electric force that one charged particle exerts on another. The electric force is shown in three ways. First, particle 2 can be dragged left or right to sample the force at various locations - the force on each particle is shown with an arrow. Second, the numerical value of each force is shown in the table at the bottom. Third, you can check the box at the top of the menu to plot a graph of the electric force as a function of position. For the graph (and the numerical values), we define positive force as a force pointing to the right, and negative force as a force pointing to the left. The Point Charge Forces in One-Dimension was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_bu_Point_Charge_Force_1D.jar file will run the program if Java is installed.

Duffy, Andrew

2010-04-16

75

Energy Technology Data Exchange (ETDEWEB)

Waveforms from nuclear explosions at the E. Kazakhistan test site were recorded at ARU GAR at the distance range studied for Nevada Test Site explosions (between 1380 and 1540 km). Waveforms at ARU are characterized by weak initial P waves following by strong secondary arrivals within 5 seconds. Within approximately 14 seconds comes a strong later arrival, preceded by a longer-period arrival. Filtering in different frequency bands shows initial P wave long period arrival are consistent with an amplitude ratio of 1:2. Other arrivals are high-frequency vanish for periods longer than 2 sec. Synthetic reflectivity seismogram calculations test previous P wave models for Central Eurasia for compatibility with identified waveform patterns. Most models produce impulsive 1st arrivals fail to generate strong secondary arrivals. Only models by Mechie et al. (1993) Priestley Cipar (1994) show some observed P wave patterns. With a new model strong secondary arrivals are generated with observed frequencies attribute these arrivals to a Moho underside reflection free surface reflection PP.

Koch, K.

1994-07-01

76

Tunneling into 1D and quasi-1D conductors and Luttinger-liquid behavior

The paper addresses the problem whether and how it is possible to detect the Luttinger-liquid behavior from the $IV$ curves for tunneling to 1D or quasi-1D conductors. The power-law non-ohmic $IV$ curve, which is usually considered as a manifestation of the Luttinger-liquid behavior, can be also deduced from the theory of the Coulomb blockaded junction between 3D conductors affected by the environment effect. In both approaches the power-law exponents are determined by the ratio of the impedance of an effective electric circuit to the quantum resistance. Though two approaches predict different power-law exponents (because of a different choice of effective circuits), the difference becomes negligible for a large number of conductance channels.

Sonin, E B

2001-01-01

77

Axial turbomachine modelling with a 1D axisymmetric approach

International Nuclear Information System (INIS)

This work concerns the design and safety analysis of direct cycle gas cooled reactor. The estimation of compressor and turbine performances in transient operations is of high importance for the designer. The first goal of this study is to provide a description of compressor behaviour in unstable conditions with a better understanding than the models based on performance maps ('traditional' 0D approach). A supplementary objective is to provide a coherent description of the turbine behaviour. The turbomachine modelling approach consists in the solution of 1D axisymmetric Navier-Stokes equations on an axial grid inside the turbomachine: mass, axial momentum, circumferential momentum and total-enthalpy balances are written. Blade forces are taken into account by using compressor or turbine blade cascade steady correlations. A particular effort has been developed to generate or test correlations in low mass flow and negative mass flow regimes, based on experimental data. The model is tested on open literature cases of the gas turbine aircraft community. For compressor and turbine, steady situations are fairly described, especially for medium and high mass flow rate. The dynamic behaviour of compressor is also quite well described, even in unstable operation (surge): qualitative tendencies (role of plenum volume and role of throttle) and some quantitative characteristics (frequency) are in a good agreement with experimental data. The application to transient simulations of gas cooled nuclear reactors is concentrated on the hypothetical 10 in. break accident. The results point out the importance of the location of the pipe rupture in a hypothetical break event. In some detailed cases, compressor surge and back flow through the circuit can occur. In order to be used in a design phase, a simplified model of surge has also been developed. This simplified model is applied to the gas fast reactor (GFR) and compared quite favourably with 1D axisymmetric simulation results

2007-09-01

78

T = 0 phase diagram of 1D extended anisotropic spin- 1/2 Heisenberg model

Energy Technology Data Exchange (ETDEWEB)

For the 1D spin-1/2 Heisenberg model with ferromagnetic nearest-neighbor interaction and antiferromagnetic next-nearest neighbor one we present the phase diagram at T = 0 as obtained by DMRG analysis. The interplay of interactions generates two massless and two massive phases in the range of parameters considered. We discuss the properties of the correlations in these phases.

Plekhanov, Evgeny; Avella, Adolfo; Mancini, Ferdinando, E-mail: plekhanoff@physics.unisa.i, E-mail: avella@physics.unisa.i, E-mail: mancini@physics.unisa.i [Dipartimento di Fisica ' E.R. Caianiello' - Unita CNISM di Salerno Universita degli Studi di Salerno, I-84081 Baronissi (Italy)

2009-01-01

79

Magnon-mediated NMR quantum gates in a 1-D antiferromagnet

We propose a method of controlling a quantum logic gate in a solid-state NMR quantum computer. A switchable inter-qubit coupling can be generated by using the longitudinal component of the Suhl-Nakamura interaction induced by a local singlet-triplet excitation in a 1-D antiferromagnet with a spin gap.

Goto, A; Hashi, K; Goto, Atsushi; Shimizu, Tadashi; Hashi, Kenjiro

2002-01-01

80

D1D5 microstate geometries from string amplitudes

Digital Repository Infrastructure Vision for European Research (DRIVER)

We reproduce the asymptotic expansion of the D1D5 microstate geometries by computing the emission amplitudes of closed string states from disks with mixed D1D5 boundary conditions. Thus we provide a direct link between the supergravity and D-brane descriptions of the D1D5 microstates at non-zero string coupling. Microscopically, the profile functions characterizing the microstate solutions are encoded in the choice of a condensate for the twisted open string states connectin...

Giusto, Stefano; Morales, Jose F.; Russo, Rodolfo

2009-01-01

81

Retrieving the parameters of a seismic source from seismograms involves deconvolving the response of the medium from seismic records. Thus, in general, source parameters are determined from both seismograms and the Green functions describing the properties of the medium in which the earthquake focus is buried. The quality of each of these two datasets is equally significant for the successful determination of source characteristics. As a rule, both sets are subject to contamination by effects that decrease the resolution of the source parameters. Seismic records are generally contaminated by noise that appears as a spurious signal unrelated to the source. Since an improper model of the medium is quite often employed, due to poor knowledge of the seismic velocity of the area under study, and since the hypocentre may be mislocated, the Green functions are not without fault. Thus, structures not modelled by Green functions are assigned to the source, distorting the source mechanism. To demonstrate these effects, we performed a synthetic case study by simulating seismic observations in the Dobrá Voda area of the Little Carpathians region of Slovakia. Simplified 1-D and 3-D laterally inhomogeneous structural models were constructed, and synthetic data were calculated using the 3-D model. Both models were employed during a moment tensor inversion. The synthetic data were contaminated by random noise up to 10 and 20 % of the maximum signal amplitude. We compared the influence of these two effects on retrieving moment tensors, and determined that a poor structural model can be compensated for by high-quality data; and that, in a similar manner, a lack of data can be compensated for by a detailed model of the medium. For examples, five local events from the Dobrá Voda area were processed.

Jechumtálová, Zuzana; Bulant, Petr

2014-07-01

82

Groups naturally promote their strengths and prefer values and rules that give them an identity and an advantage. This shows up as generational tensions across cohorts who share common experiences, including common elders. Dramatic cultural events in America since 1925 can help create an understanding of the differing value structures of the Silents, the Boomers, Gen Xers, and the Millennials. Differences in how these generations see motivation and values, fundamental reality, relations with others, and work are presented, as are some applications of these differences to the dental profession. PMID:16623137

Chambers, David W

2005-01-01

83

Polymorphisms in CD1d affect antigen presentation and the activation of CD1d-restricted T cells

Digital Repository Infrastructure Vision for European Research (DRIVER)

CD1 proteins constitute a distinct lineage of antigen-presenting molecules specialized for the presentation of lipid antigens to T cells. In contrast to the extensive sequence polymorphism characteristic of classical MHC molecules, CD1 proteins exhibit limited sequence diversity. Here, we describe the identification and characterization of CD1d alleles in wild-derived mouse strains. We demonstrate that polymorphisms in CD1d affect the presentation of endogenous and exogenous ligands to CD1d-r...

Zimmer, Michael I.; Nguyen, Hanh P.; Wang, Bin; Xu, Honglin; Colmone, Angela; Felio, Kyrie; Choi, Hak-jong; Zhou, Ping; Alegre, Maria-luisa; Wang, Chyung-ru

2009-01-01

84

Come forth CD1d: Hsp110 in the regulation of intestinal epithelial CD1d expression

Digital Repository Infrastructure Vision for European Research (DRIVER)

CD1d, a nonclassical MHC class I–like molecule, is prominently expressed on intestinal epithelial cells and is thought to function in the regulation of intestinal intraepithelial lymphocyte activity. Hsp110, an abundant heat shock protein present in essentially all mammalian tissues, has now been shown to upregulate CD1d expression in colonic tissue culture cell lines. Might this abundant chaperone serve an autocrine function in the regulation of CD1d expression?

Nicchitta, Christopher V.

2003-01-01

85

Vlasov-Poisson in 1D: waterbags

We revisit in one dimension the waterbag method to solve numerically Vlasov-Poisson equations. In this approach, the phase-space distribution function $f(x,v)$ is initially sampled by an ensemble of patches, the waterbags, where $f$ is assumed to be constant. As a consequence of Liouville theorem it is only needed to follow the evolution of the border of these waterbags, which can be done by employing an orientated, self-adaptive polygon tracing isocontours of $f$. This method, which is entropy conserving in essence, is very accurate and can trace very well non linear instabilities as illustrated by specific examples. As an application of the method, we generate an ensemble of single waterbag simulations with decreasing thickness, to perform a convergence study to the cold case. Our measurements show that the system relaxes to a steady state where the gravitational potential profile is a power-law of slowly varying index $\\beta$, with $\\beta$ close to $3/2$ as found in the literature. However, detailed analys...

Colombi, Stéphane

2014-01-01

86

Vlasov-Poisson in 1D: waterbags

We revisit in one dimension the waterbag method to solve numerically Vlasov-Poisson equations. In this approach, the phase-space distribution function f (x, v) is initially sampled by an ensemble of patches, the waterbags, where f is assumed to be constant. As a consequence of Liouville theorem, it is only needed to follow the evolution of the border of these waterbags, which can be done by employing an orientated, self-adaptive polygon tracing isocontours of f. This method, which is entropy conserving in essence, is very accurate and can trace very well non-linear instabilities as illustrated by specific examples. As an application of the method, we generate an ensemble of single-waterbag simulations with decreasing thickness to perform a convergence study to the cold case. Our measurements show that the system relaxes to a steady state where the gravitational potential profile is a power law of slowly varying index ?, with ? close to 3/2 as found in the literature. However, detailed analysis of the properties of the gravitational potential shows that at the centre, ? > 1.54. Moreover, our measurements are consistent with the value ? = 8/5 = 1.6 that can be analytically derived by assuming that the average of the phase-space density per energy level obtained at crossing times is conserved during the mixing phase. These results are incompatible with the logarithmic slope of the projected density profile ? - 2 ? -0.47 obtained recently by Schulz et al. using an N-body technique. This sheds again strong doubts on the capability of N-body techniques to converge to the correct steady state expected in the continuous limit.

Colombi, Stéphane; Touma, Jihad

2014-07-01

87

Energy Technology Data Exchange (ETDEWEB)

This research undertook scientific problem inherent in the monitoring of a comprehensive nuclear test ban treaty; establishing confidence that the seismograms from small and moderate-sized events are understood, thus, identifiable. This requires an understanding of broadband regional distance seismic phases from both explosions and earthquakes, the excitation of the various phases, and their dependence on source. Data from open broadband stations across the Andean Cordillera were used in research to evaluate the utility of the spectral characteristics of regional distance seismo-grams of phase ratio pairs (Pg/Lg; Pn/Lg). The entire regional waveforms for seismic events traversing the Andes were modeled providing detail of crustal thickness, the average crustal velocity, and propagation efficiency. Further, this report details research to treat a single regional distance station as a seismic observatory and to establish a relative location procedure in which to locate smaller magnitude events relative to an established epicentral coordinate. Finally, the results are reported of a temporary broadband deployment used to record the DOE hosted Non-Proliferation Experiment; exploration of how geologic environment changes affects discriminants.

Wallace, T.C.; Beck, S.L.

1995-06-01

88

Ion-sensing properties of 1D vanadium pentoxide nanostructures

The application of one-dimensional (1D) V2O5· nH2O nanostructures as pH sensing material was evaluated. 1D V2O5· nH2O nanostructures were obtained by a hydrothermal method with systematic control of morphology forming different nanostructures: nanoribbons, nanowires and nanorods. Deposited onto Au-covered substrates, 1D V2O5· nH2O nanostructures were employed as gate material in pH sensors based on separative extended gate FET as an alternative to provide FET isolation from the chemical environment. 1D V2O5· nH2O nanostructures showed pH sensitivity around the expected theoretical value. Due to high pH sensing properties, flexibility and low cost, further applications of 1D V2O5· nH2O nanostructures comprise enzyme FET-based biosensors using immobilized enzymes.

Vieira, Nirton CS; Avansi, Waldir; Figueiredo, Alessandra; Ribeiro, Caue; Mastelaro, Valmor R.; Guimarães, Francisco EG

2012-06-01

89

First Observation of a Upsilon(1D) State

We present the first evidence for the production of Upsilon(1D) states in the four-photon cascade, Upsilon(3S)-->gamma chib(2P), chib(2P)-->gamma Upsilon(1D), Upsilon(1D)-->gamma chib(1P), chib(1P)-->gamma Upsilon(1S), followed by the Upsilon(1S) annihilation into e+e- or mu+mu-. The signal has a significance of 10.2 standard deviations. The measured product branching ratio for these five decays, (2.5+-0.5+-0.5)x10^(-5), is consistent with the theoretical estimates. The data are dominated by the production of one Upsilon(1D) state consistent with the J=2 assignment. Its mass is determined to be (10161.1+-0.6+-1.6) MeV, which is consistent with the predictions from potential models and lattice QCD calculations. We also searched for Upsilon(3S)-->gammachib(2P), chib(2P)-->gammaUpsilon(1D), followed by either Upsilon(1D)-->eta Upsilon(1S) or Upsilon(1D)-->pi+pi- Upsilon(1S). We find no evidence for such decays and set upper limits on the product branching ratios.

Bonvicini, G; Dubrovin, M; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Weinstein, A J; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Patterson, J R; Pedlar, T K; Peterson, D; Pivarski, J; Riley, D; Rosner, J L; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Sun, W M; Thayer, J G; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stöck, H; Yelton, J; Eisenstein, B I; Gollin, G D; Karliner, I; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Besson, D; Gao, K Y; Gong, D T; Kubota, Y; Li, S Z; Poling, R A; Scott, A W; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ernst, J; Arms, K; Eckhart, E; Gan, K K; Gwon, C; Severini, H; Skubic, P L; Asner, D M; Dytman, S A; Mehrabyan, S S; Müller, J A; Nam, S; Savinov, V; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cummings, J P; Danko, I; Napolitano, J; Cronin-Hennessy, D; Park, C S; Park, W; Thayer, J B; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Haynes, J; Menaa, N; Mountain, R; Muramatsu, H; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, Kevin; Mahmood, A H; Csorna, S E

2004-01-01

90

Consistent 1-D neutronics modeling using current conservation factors

Energy Technology Data Exchange (ETDEWEB)

The 3D neutronics code is the ultimate means of achieving high fidelity in the neutronic simulation of the reactor core, nevertheless the 1D neutronic s model is needed to replace 3D model in many practical circumstances. In this paper a 3D consistent 1D model based on nonlinear analytic nodal method is developed. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. To test the 1D model with CCF, three cases of steady state calculation were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. With the planar averaged group constants and the CCFs introduced in this paper, it becomes possible to reproduce the 3D reference solution from the 1D model. Thus the 1D model with CCF can provide the preciser results at the steady state, and it is expected that the slow transient such as the day range xenon dynamics can be simulated more accurately with 1D model.

Lee, K. B.; Joo, H. G.; Cho, B. O.; Zee, S. Q. [KAERI, Taejon (Korea, Republic of)

1999-10-01

91

First Observation of a Upsilon(1D) State

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the first evidence for the production of Upsilon(1D) states in the four-photon cascade, Upsilon(3S)-->gamma chib(2P), chib(2P)-->gamma Upsilon(1D), Upsilon(1D)-->gamma chib(1P), chib(1P)-->gamma Upsilon(1S), followed by the Upsilon(1S) annihilation into e+e- or mu+mu-. The signal has a significance of 10.2 standard deviations. The measured product branching ratio for these five decays, (2.5+-0.5+-0.5)x10^(-5), is consistent with the theoretical estimates. The data...

Bonvicini, G.; Collaboration, Cleo

2004-01-01

92

Exploiting the CD1d-iNKT cell axis for potentiation of DC-based cancer vaccines.

Invariant natural killer T cells (iNKT) and dendritic cells (DC) play a central role in tumor immunity through downstream activation of immune effector cells by pro-inflammatory cytokines. Evidence is accumulating that the CD1d-iNKT cell axis can be effectively used to potentiate DC-based cancer vaccines. Here, we provide a detailed methodology for the generation of (CD1d-expressing) monocyte-derived DC (moDC) and their subsequent loading with the iNKT cell agonist ?-galactosylceramide (?-GalCer) or their direct ligation by agonistic anti-CD1d monoclonal antibodies. PMID:24619678

Lameris, Roeland; Schneiders, Famke L; de Gruijl, Tanja D; van der Vliet, Hans J

2014-01-01

93

1D photonic crystal sensor integrated in a microfluidic system

DEFF Research Database (Denmark)

A refractive index sensor was designed as a 1D resonator incorporated in a microfluidic channel, where aqueous solutions were injected. A sensitivity of 480 nm/RIU and a minimum difference of Deltan = 0.002 were determined.

Nunes, Pedro; Mortensen, Asger

2009-01-01

94

A Reduced Complexity Quasi-1D Viterbi Detector

Directory of Open Access Journals (Sweden)

Full Text Available This paper develops a reduced complexity quasi-1D detector for optical storage devices and digital communication system. Superior performance of the proposed detector is evidenced by simulation results.

Rabi N. Panda

2011-02-01

95

A Reduced Complexity Quasi-1D Viterbi Detector

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper develops a reduced complexity quasi-1D detector for optical storage devices and digital communication system. Superior performance of the proposed detector is evidenced by simulation results.

Panda, Rabi N.; Nihar Panda; Panigrahi, Siba P.; Mohanty, Rashmi R.; Sahu, Manoj K.; Sahu, Himanshu S.; Anupama Majhi; Mishra, Umesh C.

2011-01-01

96

Towards a reasoned 1-D river model calibration

Digital Repository Infrastructure Vision for European Research (DRIVER)

Model calibration remains a critical step in numerical modelling. After many attempts to automate this task in water-related domains, questions about the actual need for calibrating physics-based models are still open. This article proposes a framework for good model calibration practice for end-users of 1-D hydraulic simulation codes. This framework includes a formalisation of objects used in 1-D river hydraulics along with a generic conceptual description of the model calibration process. I...

Vidal, J. P.; Moisan, S.; Faure, J. B.; Dartus, D.

2005-01-01

97

We try to compare and evaluate the nature of tsunami generation and seismic wave generation in occurrence of the 2011 Tohoku-Oki earthquake (hereafter, called as TOH11), in terms of two type of moment rate functions, inferred from finite source imaging of tsunami waveforms and seismic waveforms. Since 1970's, the nature of "tsunami earthquakes" has been discussed in many researches (e.g. Kanamori, 1972; Kanamori and Kikuchi, 1993; Kikuchi and Kanamori, 1995; Ide et al., 1993; Satake, 1994) mostly based on analysis of seismic waveform data , in terms of the "slow" nature of tsunami earthquakes (e.g., the 1992 Nicaragura earthquake). Although TOH11 is not necessarily understood as a tsunami earthquake, TOH11 is one of historical earthquakes that simultaneously generated large seismic waves and tsunami. Also, TOH11 is one of earthquakes which was observed both by seismic observation network and tsunami observation network around the Japanese islands. Therefore, for the purpose of analyzing the nature of tsunami generation, we try to utilize tsunami waveform data as much as possible. In our previous studies of TOH11 (Fujihara et al., 2012a; Fujihara et al., 2012b), we inverted tsunami waveforms at GPS wave gauges of NOWPHAS to image the spatio-temporal slip distribution. The "temporal" nature of our tsunami source model is generally consistent with the other tsunami source models (e.g., Satake et al, 2013). For seismic waveform inversion based on 1-D structure, here we inverted broadband seismograms at GSN stations based on the teleseismic body-wave inversion scheme (Kikuchi and Kanamori, 2003). Also, for seismic waveform inversion considering the inhomogeneous internal structure, we inverted strong motion seismograms at K-NET and KiK-net stations, based on 3-D Green's functions (Fujihara et al., 2013a; Fujihara et al., 2013b). The gross "temporal" nature of our seismic source models are generally consistent with the other seismic source models (e.g., Yoshida et al., 2011; Ide at al., 2011; Yagi and Fukahata, 2011; Suzuki et al., 2011). The comparison of two type of moment rate functions, inferred from finite source imaging of tsunami waveforms and seismic waveforms, suggested that there was the time period common to both seismic wave generation and tsunami generation followed by the time period unique to tsunami generation. At this point, we think that comparison of the absolute values of moment rates is not so meaningful between tsunami waveform inversion and seismic waveform inversion, because of general ambiguity of rigidity values of each subfault in the fault region (assuming the rigidity value of 30 GPa of Yoshida et al (2011)). Considering this, the normalized value of moment rate function was also evaluated and it does not change the general feature of two moment rate functions in terms of duration property. Furthermore, the results suggested that tsunami generation process apparently took more time than seismic wave generation process did. Tsunami can be generated even by "extra" motions resulting from many suggested abnormal mechanisms. These extra motions may be attribute to the relatively larger-scale tsunami generation than expected from the magnitude level from seismic ground motion, and attribute to the longer duration of tsunami generation process.

Fujihara, S.; Korenaga, M.; Kawaji, K.; Akiyama, S.

2013-12-01

98

Emergent space-time supersymmetry in 3+1D Weyl and 2+1D Dirac semimetals

Unlike bosonic symmetries such as translations, supersymmetry (SUSY) is intrinsically fermionic by interchanging bosons and fermions. No direct evidences of SUSY have been revealed in nature yet. In this paper, using renormalization group analysis, we theoretically show that SUSY emerges at pair density wave (PDW) transitions in 3+1D Weyl semimetals and 2+1D Dirac semimetals. We construct explicit fermionic lattice models featuring 3+1D Weyl fermions or 2+1D massless two-component Dirac fermions and show that PDW is the leading instability as short-range interactions exceed a critical value and that the N=2 SUSY emerges at the continuous PDW transitions. We further discuss possible routes to realize these lattice models and experimental signatures of emergent SUSY at the PDW criticality.

Jian, Shao-Kai; Yao, Hong

2014-01-01

99

Propagation of compressional elastic waves through a 1-D medium with contact nonlinearities

Digital Repository Infrastructure Vision for European Research (DRIVER)

Propagation of monochromatic elastic waves across cracks is investigated in 1D, both theoretically and numerically. Cracks are modeled by nonlinear jump conditions. The mean dilatation of a single crack and the generation of harmonics are estimated by a perturbation analysis, and computed by the harmonic balance method. With a periodic and finite network of cracks, direct numerical simulations are performed and compared with Bloch-Floquet's analysis.

Lombard, Bruno; Piraux, Joe?l

2009-01-01

100

Quantum reactive scattering of O({sup 1}D) + H{sub 2} and O({sup 1}D) + HD.

Energy Technology Data Exchange (ETDEWEB)

A recently developed wavepacket method is applied to study the quantum dynamics of the reactions O({sup 1}D)+H2{yields}OH+H and O({sup 1}D) +HD{yields}OH(OD)+D(H). The ab initio based, global, 1A {prime} potential energy surface of Ho et al. is employed. The results of three-dimensional, total angular momentum J=0 scattering calculations are presented and discussed, with emphasis on qualitative features of the dynamics.

Balint-Kurti, G. G.; Gonzalez, A. I.; Goldfield, E. M.; Gray, S. K.; Chemistry; Univ. of Bristol; Wayne State Univ.

1998-01-01

101

2D/1D approximations to the 3D neutron transport equation. I: Theory

Energy Technology Data Exchange (ETDEWEB)

A new class of '2D/1D' approximations is proposed for the 3D linear Boltzmann equation. These approximate equations preserve the exact transport physics in the radial directions x and y and diffusion physics in the axial direction z. Thus, the 2D/1D equations are more accurate approximations of the 3D Boltzmann equation than the conventional 3D diffusion equation. The 2D/1D equations can be systematically discretized, to yield accurate simulation methods for 3D reactor core problems. The resulting solutions will be more accurate than 3D diffusion solutions, and less expensive to generate than standard 3D transport solutions. In this paper, we (i) show that the simplest 2D/1D equation has certain desirable properties, (ii) systematically discretize this equation, and (iii) derive a stable iteration scheme for solving the discrete system of equations. In a companion paper [1], we give numerical results that confirm the theoretical predictions of accuracy and iterative stability. (authors)

Kelley, B. W.; Larsen, E. W. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-07-01

102

3"1D, 4"1D, 5"1D 4"1F, 5"1F and 6"1F states of He

International Nuclear Information System (INIS)

Hylleraas method variational calculations up to 367 terms are reported for the three lowest states of neutral helium with "1D and "1F symmetry. Convergence arguments are presented to obtain new estimates of the exact non-relativistic energies of these states. The reliability of the estimates ranges from 10"-"6 au in the worst case to 10"-"9 au in the best case. (author)

1982-02-14

103

A sensitive and specific radioimmunoassay for 1-?-d arabino furanosylcytosine

International Nuclear Information System (INIS)

In order to determine the blood level of 1-?-D-arabinofuranosylcytosine (Ara-C), an antileukemic agent, a sensitive and specific radioimmunoassay (RIA) system using anti-Ara-C serum, (5-3H) Ara-C and a dextran-coated charcoal method has been developed. The anti-Ara-C serum obtained from a guinea pig was hardly cross-reactive with 1-?-D-arabinofuranosyluracil (Ara-U), tetrahydrouridine (THU) and other Ara-C analogues. The RIA system for Ara-C could detect concentrations as low as 60 pg/ml in plasma. Average of the intra- and inter-assay variancies at 5, 10, 20 ng/ml were 4.3% and 5.6% respectively. Ara-C in blood samples obtained from human patients who orally received N4-palmitoyl-1-?-D-arabinofuranosyl-cytosine (PL-AC) was determined by the present RIA system. (author)

1984-09-01

104

Collisional quenching of O(1D) by O(3P)

Metastable O(1D) atoms may be quenched in collisions with ground state O(3P) atoms by transitions in the avoided crossing regions of the three lowest 3Pi(g) states of O2 of which the lowest separates to O(3P) + O(3P) and the two upper to O(3P) + O(1D). Quantal calculations of the adiabatic potential energy curves of the 3Pi(g) states are carried out with particular attention to an avoided crossing region in the lowest two states around a nuclear separation of 3.2a(0). Diabatic potential matrix elements are constructed from the adiabatic curves by imposing the requirement that they be smooth everywhere. A multi-state diabatic formulation is used to describe the scattering and the cross-sections for the collision-induced quenching of O(1D) atoms are calculated.

Yee, J.-H.; Guberman, Steven L.; Dalgarno, A.

1990-01-01

105

The GIRAFFE Archive: 1D and 3D Spectra

The GIRAFFE Archive (giraffe-archive.obspm.fr'>http://giraffe-archive.obspm.fr) contains the reduced spectra observed with the intermediate and high resolution multi-fiber spectrograph installed at VLT/UT2 (ESO). In its multi-object configuration and the different integral field unit configurations, GIRAFFE produces 1D spectra and 3D spectra. We present here the status of the archive and the different functionalities to select and download both 1D and 3D data products, as well as the present content. The two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations. These latter products can be explored using the VO Paris Euro3D Client (http://voplus.obspm.fr/ chil/Euro3D).

Royer, F.; Jégouzo, I.; Tajahmady, F.; Normand, J.; Chilingarian, I.

2013-10-01

106

The 1D Hubbard model within the Composite Operator Method

Although effective for two dimensional (2D) systems, some approximations may fail in describing the properties of one-dimensional (1D) models, which belong to a different universality class. In this paper, we analyze the adequacy of the Composite Operator Method (COM), which provides a good description of many features of 2D strongly correlated systems, in grasping the physics of 1D models. To this purpose, the 1D Hubbard model is studied within the framework of the COM by considering a two-pole approximation and a paramagnetic ground state. The local, thermodynamic and single-particle properties, the correlation functions and susceptibilities are calculated in the case of half filling and arbitrary filling. The results are compared with those obtained by the Bethe Ansatz (BA) as well as by other numerical and analytical techniques. The advantages and limitations of the method are analyzed in detail.

Avella, A; Sánchez-López, M M; Avella, Adolfo; Mancini, Ferdinando; Sanchez-Lopez, Maria del Mar

2000-01-01

107

Interior gradient estimate for 1-D anisotropic curvature flow

Directory of Open Access Journals (Sweden)

Full Text Available We establish the interior gradient estimate for general 1-D anisotropic curvature flow. The estimate depends only on the height of the graph and not on the gradient at initial time. The proof relies on the monotonicity property of the number of zeros for the parabolic equation.

Yoshihiro Tonegawa

2005-11-01

108

Simulation of Organic Solar Cells Using AMPS-1D Program

Directory of Open Access Journals (Sweden)

Full Text Available The analysis of microelectronic and photonic structure in one dimension program [AMPS-1D] program has been successfully used to study inorganic solar cells. In this work the program has been used to optimize the performance of the organic solar cells. The cells considered consist of poly(2-methoxy-5-(3,7- dimethyloctyloxy-1,4-phenylenevinylene [MDMO-PPV

Samah G. Babiker

2012-03-01

109

Just Renormalizable TGFT's on U(1) d with Gauge Invariance

We study the polynomial Abelian or U(1) d Tensorial Group Field Theories equipped with a gauge invariance condition in any dimension d. We prove the just renormalizability at all orders of perturbation of the and random tensor models. We also deduce that the tensor model is super-renormalizable.

Samary, Dine Ousmane; Vignes-Tourneret, Fabien

2014-07-01

110

Transport correlation functions in 1D disordered media

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study the correlation functions of the transmission coefficients of a disordered 1D system taken for two slightly différent values E and E' of the incident wave energy. Characteristic length scales associated with the decay of these correlation functions are obtained and are shown to differ from the length scale associated with the correlator

1987-01-01

111

Polaron in a quasi 1D cylindrical quantum wire

Directory of Open Access Journals (Sweden)

Full Text Available Polaron states in a quasi 1D cylindrical quantum wire with a parabolic confinement potential are investigated applying the Feynman variational principle. The effect of the wire radius on the polaron ground state energy level, the mass and the Fröhlich electron-phonon-coupling constant are obtained for the case of a quasi 1D cylindrical quantum wire. The effect of anisotropy of the structure on the polaron ground state energy level and the mass are also investigated. It is observed that as the wire radius tends to zero, the polaron mass and energy diverge logarithmically. The polaron mass and energy differ from the canonical strong-coupling behavior by the Fröhlich electron-phonon coupling constant and the radius of the quasi 1D cylindrical quantum wire that are expressed through a logarithmic function. Moreover, it is observed that the polaron energy and mass for strong coupling for the case of the quasi 1D cylindrical quantum wire are greater than those for bulk crystals. It is also observed that the anisotropy of the structure considerably affects both the polaron ground state energy level and the mass. It is found that as the radius of the cylindrical wire reduces, the regimes of the weak and intermediate coupling polaron shorten while the region of the strong coupling polaron broadens and extends into those of the weak and intermediate ones. Analytic expressions for the polaron ground state energy level and mass are derived for the case of strong coupling polarons.

I.Nsangou

2005-01-01

112

A 1D wavelet filtering for ultrasound images despeckling

Ultrasound images appearance is characterized by speckle, shadows, signal dropout and low contrast which make them really difficult to process and leads to a very poor signal to noise ratio. Therefore, for main imaging applications, a denoising step is necessary to apply successfully medical imaging algorithms on such images. However, due to speckle statistics, denoising and enhancing edges on these images without inducing additional blurring is a real challenging problem on which usual filters often fail. To deal with such problems, a large number of papers are working on B-mode images considering that the noise is purely multiplicative. Making such an assertion could be misleading, because of internal pre-processing such as log compression which are done in the ultrasound device. To address those questions, we designed a novel filtering method based on 1D Radiofrequency signal. Indeed, since B-mode images are initially composed of 1D signals and since the log compression made by ultrasound devices modifies noise statistics, we decided to filter directly the 1D Radiofrequency signal envelope before log compression and image reconstitution, in order to conserve as much information as possible. A bi-orthogonal wavelet transform is applied to the log transform of each signal and an adaptive 1D split and merge like algorithm is used to denoise wavelet coefficients. Experiments were carried out on synthetic data sets simulated with Field II simulator and results show that our filter outperforms classical speckle filtering methods like Lee, non-linear means or SRAD filters.

Dahdouh, Sonia; Dubois, Mathieu; Frenoux, Emmanuelle; Osorio, Angel

2010-03-01

113

1D Scaling with Ablation for K-Shell Radiation from Stainless Steel Wire Arrays

International Nuclear Information System (INIS)

A 1D Lagrangian magnetohydrodynamic z-pinch simulation code is extended to include wire ablation. The plasma transport coefficients are calibrated to reproduce the K-shell yields measured on the Z generator for three stainless steel arrays of diameter 55 mm and masses ranging from 1.8 to 2.7 mg. The resulting 1D scaling model is applied to a larger SS array (65 mm and 2.5 mg) on the refurbished Z machine. Simulation results predict a maximum K-shell yield of 77 kJ for an 82 kV charging voltage. This maximum drops to 42 kJ at 75 kV charging. Neglecting the ablation precursor leads to a ?10% change in the calculated yield.

2009-01-21

114

Effect of the twist operator in the D1D5 CFT

The D1D5 CFT has been very useful in the study of black holes. The interaction in this theory involves a twist operator, which links together different copies of a free CFT. For the bosonic fields, we examine the action of this twist when it links together CFT copies with winding numbers M and N to produce a copy with winding M+N. Starting with the vacuum state generates a squeezed state, which we compute. Starting with an initial excitation on one of the copies gives a linear combination of excitations on the final state, which we also compute. These results generalize earlier computations where these quantities were computed for the special case M=N=1. Our results should help in understanding the thermalization process in the D1D5 CFT, which gives the dual of black hole formation in the bulk.

Carson, Zaq; Mathur, Samir D; Turton, David

2014-01-01

115

𝒩-Structures Applied to Closed Ideals in BCH-Algebras

Directory of Open Access Journals (Sweden)

Full Text Available The notions of 𝒩-subalgebras and 𝒩-closed ideals in BCH-algebras are introduced, and the relation between 𝒩-subalgebras and 𝒩-closed ideals is considered. Characterizations of 𝒩-subalgebras and 𝒩-closed ideals are provided. Using special subsets, 𝒩-subalgebras and 𝒩-closed ideals are constructed. A condition for an 𝒩-subalgebra to be an 𝒩-closed ideal is discussed. Given an 𝒩-structure, the greatest 𝒩-closed ideal which is contained in the 𝒩-structure is established.

Mehmet Ali Öztürk

2010-01-01

116

1D design style implications for mask making and CEBL

At advanced nodes, CMOS logic is being designed in a highly regular design style because of the resolution limitations of optical lithography equipment. Logic and memory layouts using 1D Gridded Design Rules (GDR) have been demonstrated to nodes beyond 12nm.[1-4] Smaller nodes will require the same regular layout style but with multiple patterning for critical layers. One of the significant advantages of 1D GDR is the ease of splitting layouts into lines and cuts. A lines and cuts approach has been used to achieve good pattern fidelity and process margin to below 12nm.[4] Line scaling with excellent line-edge roughness (LER) has been demonstrated with self-aligned spacer processing.[5] This change in design style has important implications for mask making: • The complexity of the masks will be greatly reduced from what would be required for 2D designs with very complex OPC or inverse lithography corrections. • The number of masks will initially increase, as for conventional multiple patterning. But in the case of 1D design, there are future options for mask count reduction. • The line masks will remain simple, with little or no OPC, at pitches (1x) above 80nm. This provides an excellent opportunity for continual improvement of line CD and LER. The line pattern will be processed through a self-aligned pitch division sequence to divide pitch by 2 or by 4. • The cut masks can be done with "simple OPC" as demonstrated to beyond 12nm.[6] Multiple simple cut masks may be required at advanced nodes. "Coloring" has been demonstrated to below 12nm for two colors and to 8nm for three colors. • Cut/hole masks will eventually be replaced by e-beam direct write using complementary e-beam lithography (CEBL).[7-11] This transition is gated by the availability of multiple column e-beam systems with throughput adequate for high- volume manufacturing. A brief description of 1D and 2D design styles will be presented, followed by examples of 1D layouts. Mask complexity for 1D layouts patterned directly will be compared to mask complexity for lines and cuts at nodes larger than 20nm. No such comparison is possible below 20nm since single-patterning does not work below ~80nm pitch using optical exposure tools. Also discussed will be recently published wafer results for line patterns with pitch division by-2 and by-4 at sub-12nm nodes, plus examples of post-etch results for 1D patterns done with cut masks and compared to cuts exposed by a single-column e-beam direct write system.

Smayling, Michael C.

2013-09-01

117

Plasmonic Excitations of 1D Metal-Dielectric Interfaces in 2D Systems: 1D Surface Plasmon Polaritons

Surface plasmon-polariton (SPP) excitations of metal-dielectric interfaces are a fundamental light-matter interaction which has attracted interest as a route to spatial confinement of light far beyond that offered by conventional dielectric optical devices. Conventionally, SPPs have been studied in noble-metal structures, where the SPPs are intrinsically bound to a 2D metal-dielectric interface. Meanwhile, recent advances in the growth of hybrid 2D crystals, which comprise laterally connected domains of distinct atomically thin materials, provide the first realistic platform on which a 2D metal-dielectric system with a truly 1D metal-dielectric interface can be achieved. Here we show for the first time that 1D metal-dielectric interfaces support a fundamental 1D plasmonic mode (1DSPP) which exhibits cutoff behavior that provides dramatically improved light confinement in 2D systems. The 1DSPP constitutes a new basic category of plasmon as the missing 1D member of the plasmon family: 3D bulk plasmon, 2DSPP, 1DSPP, and 0D localized SP.

Mason, Daniel R.; Menabde, Sergey G.; Yu, Sunkyu; Park, Namkyoo

2014-01-01

118

D1-D5-P microstates at the cap

The geometries describing D1-D5-P bound states in string theory have three regions: flat asymptotics, an anti-de Sitter throat, and a 'cap' region at the bottom of the throat. We identify the CFT description of a known class of supersymmetric D1-D5-P microstate geometries which describe degrees of freedom in the cap region. The class includes both regular solutions and solutions with conical defects, and generalizes configurations with known CFT descriptions: a parameter related to spectral flow in the CFT is generalized from integer to fractional values. We provide strong evidence for this identification by comparing the massless scalar excitation spectrum between gravity and CFT and finding exact agreement.

Giusto, Stefano; Mathur, Samir D; Turton, David

2012-01-01

119

Universal quantum walks and adiabatic algorithms by 1D Hamiltonians

We construct a family of time-independent nearest-neighbor Hamiltonians coupling eight-state systems on a 1D ring that enables universal quantum computation. Hamiltonians in this family can achieve universality either by driving a continuous-time quantum walk or by terminating an adiabatic algorithm. In either case, the universality property can be understood as arising from an efficient simulation of a programmable quantum circuit. Using gadget perturbation theory, one can demonstrate the same kind of universality for related Hamiltonian families acting on qubits in 2D. Our results demonstrate that simulating 1D chains of spin-7/2 particles is BQP-hard, and indeed BQP-complete because the outputs of decision problems can be encoded in the outputs of such simulations.

Chase, Bradley A

2008-01-01

120

International Nuclear Information System (INIS)

It is believed that the D1D5 brane system is described by an 'orbifold CFT' at a special point in moduli space. We first develop a general formulation relating amplitudes in a d-dimensional CFT to absorption/emission of quanta from flat infinity. We then construct the D1D5 vertex operators for minimally coupled scalars in supergravity, and use these to compute the CFT amplitude for emission from a state carrying a single excitation. Using spectral flow we relate this process to one where we have emission from a highly excited initial state. In each case the radiation rate is found to agree with the radiation found in the gravity dual.

2009-10-01

121

On the 1D Coulomb Klein-Gordon equation

International Nuclear Information System (INIS)

For a single particle of mass m experiencing the potential -?/vertical bar x vertical bar, the 1D Klein-Gordon equation is mathematically underdefined even when ? 2 the ground-state energy E decreases through zero, and soon after that mR reaches a finite critical value below which E becomes complex, signalling a breakdown of the single-particle theory. At this critical point of the curve E(mR) the Klein-Gordon norm changes sign: the curve has a lower branch describing a bound antiparticle state, with positive energy -E, which exists for mR between the critical and some higher value where E reaches -m. Though apparently unanticipated in this context, similar scenarios are in fact familiar for strong short-range potentials (1D or 3D), and also for strong 3D Coulomb potentials with ? of order unity

2007-02-02

122

Iron-based 1D nanostructures by electrospinning process

International Nuclear Information System (INIS)

Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe2O3) nanotubes and polycrystalline Fe3C nanofibers were obtained by simple air or mixed gas (H2, Ar) annealing treatments. Using the air annealing treatment, a high control of the morphology as well as of the wall thickness of the nanotubes was demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H2 and Ar) were used for the annealing treatments, for the first time polycrystalline Fe3C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe3C nanoparticle stability and nanofiber cohesion. The morphology and structural properties of all these iron-based 1D nanostructures were fully characterized by SEM, TEM, XRD and Raman spectroscopy.

2010-03-26

123

Developing 1D nanostructure arrays for future nanophotonics

Directory of Open Access Journals (Sweden)

Full Text Available AbstractThere is intense and growing interest in one-dimensional (1-D nanostructures from the perspective of their synthesis and unique properties, especially with respect to their excellent optical response and an ability to form heterostructures. This review discusses alternative approaches to preparation and organization of such structures, and their potential properties. In particular, molecular-scale printing is highlighted as a method for creating organized pre-cursor structure for locating nanowires, as well as vapor–liquid–solid (VLS templated growth using nano-channel alumina (NCA, and deposition of 1-D structures with glancing angle deposition (GLAD. As regards novel optical properties, we discuss as an example, finite size photonic crystal cavity structures formed from such nanostructure arrays possessing highQand small mode volume, and being ideal for developing future nanolasers.

Cooke DG

2006-01-01

124

Unfrozen spin effect in a composite 1D topological superconductor

The spin of Majorana fermions (MF) is nearly frozen by the applied magnetic field in a composite 1D topological superconductor due to the weak spin-orbit coupling (SOC). In this work, we address theoretically the strong SOC limit and weak-magnetic-field effect, under which the spin degree of freedom of MFs is reactivated and dependent on the wire direction. The quantized zero-energy conductance peak in a bent N/S wire junction can be severely suppressed. The MF phase is significantly modified due to the spin noncollinearity and the fusion of MFs is independent of the wire direction, which is opposite to the strong-magnetic-field case. It is also found that the spatial distribution of an MF could be heavily affected by the wire direction. The findings are helpful to identify and braid MFs in the 1D wire network.

Wang, J.; Hao, L.; Yang, Y. H.; Chan, K. S.

2013-08-01

125

Sandia reactor kinetics codes: SAK and PK1D

International Nuclear Information System (INIS)

The Sandia Kinetics code (SAK) is a one-dimensional coupled thermal-neutronics transient analysis code for use in simulation of reactor transients. The time-dependent cross section routines allow arbitrary time-dependent changes in material properties. The one-dimensional heat transfer routines are for cylindrical geometry and allow arbitrary mesh structure, temperature-dependent thermal properties, radiation treatment, and coolant flow and heat-transfer properties at the surface of a fuel element. The Point Kinetics 1 Dimensional Heat Transfer Code (PK1D) solves the point kinetics equations and has essentially the same heat-transfer treatment as SAK. PK1D can address extended reactor transients with minimal computer execution time

1978-01-01

126

Just Renormalizable TGFT's on $U(1)^{d}$ with Gauge Invariance

We study the polynomial Abelian or $U(1)^d$ Tensorial Group Field Theories equipped with a gauge invariance condition in any dimension $d$. From our analysis, we prove the just renormalizability at all orders of perturbation of the $\\vp^4_6$ and $\\vp^6_5$ random tensor models. We also deduce that the $\\vp^4_5$ tensor model is super-renormalizable.

Samary, Dine Ousmane

2012-01-01

127

Extended electronic states in disordered 1-d lattices: an example

Digital Repository Infrastructure Vision for European Research (DRIVER)

We discuss a very simple model of a 1-d disordered lattice, in which {\\em all} the electronic eigenstates are extended. The nature of these states is examined from several viewpoints, and it is found that the eigenfunctions are not Bloch functions although they extend throughout the chain. Some typical wavefunctions are plotted. This problem originated in our earlier study of extended states in the quasiperiodic copper-mean lattice [ Sil, Karmakar, Moitra and Chakrabarti, Ph...

Sil, S.; Karmakar, S. N.; Moitra, R. K.

1993-01-01

128

Spatial stochastic resonance in 1D Ising systems

Digital Repository Infrastructure Vision for European Research (DRIVER)

The 1D Ising model is analytically studied in a spatially periodic and oscillatory external magnetic field using the transfer-matrix method. For low enough magnetic field intensities the correlation between the external magnetic field and the response in magnetization presents a maximum for a given temperature. The phenomenon can be interpreted as a resonance phenomenon induced by the stochastic heatbath. This novel "spatial stochastic resonance" has a different origin from ...

Neda, Z.; Rusz, A.; Ravasz, E.; Lakdawala, P.; Gade, P. M.

1999-01-01

129

D1-D5 black hole microstate counting from supergravity

Digital Repository Infrastructure Vision for European Research (DRIVER)

We quantize the moduli space of regular D1-D5 microstates, directly from Type IIB SUGRA. The moduli space is parametrized by a smooth closed non-selfintersecting curve in four dimensions, and we derive that the components of the curve satisfy chiral boson commutation relations, with the correct value of the effective Planck constant previously conjectured using U-duality. We use the Crnkovic-Witten-Zuckerman covariant quantization method, previously used to quantize the `bub...

Rychkov, Vyacheslav S.

2005-01-01

130

Tearing mode stability in 1D and 2D

International Nuclear Information System (INIS)

A stability code for tearing modes in 1D and 2D straight equilibria in the tokamak scaling has been developed. It finds the lowest eigenvalue of a Hermitian problem which is obtained analytically by a reduction of the full problem. The main advantage is the powerful handling of equilibria with several resonant surfaces and displaying poloidal and radial mode couplings. The code has been successfully tested by comparing it with explicitly known analytical results for external kinks. (orig.)

1981-12-01

131

Dimer impurity effect on the 1D density of states

International Nuclear Information System (INIS)

We study the effect of a dimer impurity on the local density of states (LDOS) associated with 1D tight binding Hamiltonian. Theoretical analysis is carried out by studying the resulting three-term recursion relation corresponding to the tridiagonal representation of the system Hamiltonian. We found a closed form expression for the perturbed LDOS in terms of the unperturbed one with a pre-factor that carries information on both location and potential strength of the dimer impurity.

2010-11-01

132

A coarse-mesh method for 1-D reactor kinetics

International Nuclear Information System (INIS)

A 1-D coarse-mesh reactor-kinetics method is presented. The nodal flux is approximated by means of a cubic expansion formula and the so called time-integrated algorithm is used for time integration. Application to numerical problems has shown that this method is, in addition to being fairly accurate, very fast and therefore well-suited for implementation into some of the current codes for LWR accident analysis. (author)

1986-01-01

133

Single atom transistor in a 1D optical lattice

International Nuclear Information System (INIS)

We propose a scheme utilizing a quantum interference phenomenon to switch the transport of atoms in a 1D optical lattice through a site containing an impurity atom. The impurity represents a qubit which in one spin state is transparent to the probe atoms, but in the other acts as a single atom mirror. This allows a single-shot quantum nondemolition measurement of the qubit spin

2004-10-01

134

Single atom transistor in a 1D optical lattice.

We propose a scheme utilizing a quantum interference phenomenon to switch the transport of atoms in a 1D optical lattice through a site containing an impurity atom. The impurity represents a qubit which in one spin state is transparent to the probe atoms, but in the other acts as a single atom mirror. This allows a single-shot quantum nondemolition measurement of the qubit spin. PMID:15524777

Micheli, A; Daley, A J; Jaksch, D; Zoller, P

2004-10-01

135

Regulatory Role of CD1d in Neurotropic Virus Infection?

Digital Repository Infrastructure Vision for European Research (DRIVER)

The GDVII strain of Theiler's murine encephalomyelitis virus (TMEV) causes an acute fatal polioencephalomyelitis in mice. Infection of susceptible mice with the DA strain of TMEV results in an acute polioencephalomyelitis followed by chronic immune-mediated demyelination with virus persistence in the central nervous system (CNS); DA virus infection is used as an animal model for multiple sclerosis. CD1d-restricted natural killer T (NKT) cells can contribute to viral clearance and regulation o...

Tsunoda, Ikuo; Tanaka, Tomoko; Fujinami, Robert S.

2008-01-01

136

1D Effectively Closed Subshifts and 2D Tilings

Michael Hochman showed that every 1D effectively closed subshift can be simulated by a 3D subshift of finite type and asked whether the same can be done in 2D. It turned out that the answer is positive and necessary tools were already developed in tilings theory. We discuss two alternative approaches: first, developed by N. Aubrun and M. Sablik, goes back to Leonid Levin; the second one, developed by the authors, goes back to Peter Gacs.

Bruno, Durand; Romashchenko, Andrei

2010-01-01

137

Enhancing Solar Cell Efficiencies through 1-D Nanostructures

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

Yu Kehan

2008-01-01

138

Examining Prebiotic Chemistry Using O(^1D) Insertion Reactions

Aminomethanol, methanediol, and methoxymethanol are all prebiotic molecules expected to form via photo-driven grain surface chemistry in the interstellar medium (ISM). These molecules are expected to be precursors for larger, biologically-relevant molecules in the ISM such as sugars and amino acids. These three molecules have not yet been detected in the ISM because of the lack of available rotational spectra. A high resolution (sub)millimeter spectrometer coupled to a molecular source is being used to study these molecules using O(^1D) insertion reactions. The O(^1D) chemistry is initiated using an excimer laser, and the products of the insertion reactions are adiabatically cooled using a supersonic expansion. Experimental parameters are being optimized by examination of methanol formed from O(^1D) insertion into methane. Theoretical studies of the structure and reaction energies for aminomethanol, methanediol, and methoxymethanol have been conducted to guide the laboratory studies once the methanol experiment has been optimized. The results of the calculations and initial experimental results will be presented.

Hays, Brian M.; Laas, Jacob C.; Weaver, Susanna L. Widicus

2013-06-01

139

MARG1D: One dimensional outer region matching data code

International Nuclear Information System (INIS)

A code MARG1D has been developed which computes outer region matching data of the one dimensional Newcomb equation. Matching data play an important role in the resistive (and non ideal) Magneto-hydrodynamic (MHD) stability analysis in a tokamak plasma. The MARG1D code computes matching data by using the boundary value method or by the eigenvalue method. Variational principles are derived for the problems to be solved and a finite element method is applied. Except for the case of marginal stability, the eigenvalue method is equivalent to the boundary value method. However, the eigenvalue method has the several advantages: it is a new method of ideal MHD stability analysis for which the marginally stable state can be identified, and it guarantees numerical stability in computing matching data close to marginal stability. We perform detailed numerical experiments for a model equation with analytical solutions and for the Newcomb equation in the m=1 mode theory. Numerical experiments show that MARG1D code gives the matching data with numerical stability and high accuracy. (author)

1995-01-01

140

Supported plasma-made 1D heterostructures: perspectives and applications

Energy Technology Data Exchange (ETDEWEB)

Plasma-related methods have been widely used in the fabrication of carbon nanotubes and nanofibres (NFs) and semiconducting inorganic nanowires (NWs). A natural progression of the research in the field of 1D nanostructures is the synthesis of multicomponent NWs and NFs. In this paper we review the state of the art of the fabrication by plasma methods of 1D heterostructures including applications and perspectives. Furthermore, recent developments on the use of metal seeds (Ag, Au, Pt) to obtain metal-oxide nanostructures are also extensively described. Results are shown for various metal substrates, either metal foils or supported nanoparticles/thin films of the metal where the effects of the size, surface coverage, percolation degree and thickness of the metal seeds have been systematically evaluated. The possibilities of the process are illustrated by the preparation of nanostructured films and supported NFs of different metal-oxides (Ag, Au and SiO{sub 2}, TiO{sub 2}, ZnO). Particularly, in the case of silver, the application of an oxygen plasma treatment prior to the deposition of the oxide was critical for efficiently controlling the growth of the 1D heterostructures. A phenomenological model is proposed to account for the thin-film nanostructuring and fibre formation by considering basic phenomena such as stress relaxation, inhomogeneities in the plasma sheath electrical field and the local disturbance of the oxide growth.

Borras, Ana; Macias-Montero, Manuel; Romero-Gomez, Pablo; Gonzalez-Elipe, Agustin R, E-mail: anaisabel.borras@icmse.csic.es [Materials Science Institute of Seville (CSIC-Universidad Sevilla), C/Americo Vespucio 49 41092, Sevilla (Spain)

2011-05-04

141

Numerical simulation of Ge solar cells using D-AMPS-1D code

International Nuclear Information System (INIS)

A solar cell is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. When light with photon energies greater than the band gap is absorbed by a semiconductor material, free electrons and free holes are generated by optical excitation in the material. The main characteristic of a photovoltaic device is the presence of internal electric field able to separate the free electrons and holes so they can pass out of the material to the external circuit before they recombine. Numerical simulation of photovoltaic devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. The electrical transport and the optical behavior of the solar cells discussed in this work were studied with the simulation code D-AMPS-1D. This software is an updated version of the one-dimensional (1D) simulation program Analysis of Microelectronic and Photonic Devices (AMPS) that was initially developed at The Penn State University, USA. Structures such as homojunctions, heterojunctions, multijunctions, etc., resulting from stacking layers of different materials can be studied by appropriately selecting characteristic parameters. In this work, examples of cells simulation made with D-AMPS-1D are shown. Particularly, results of Ge photovoltaic devices are presented. The role of the InGaP buffer on the device was studied. Moreover, a comparison of the simulated electrical parameters with experimental results was performed.

2012-08-15

142

Digital Repository Infrastructure Vision for European Research (DRIVER)

A method for the generation of discrete-domain two-dimensional (2-D) transfer functions possessing variable magnitude and contour characteristics is presented in this paper. The proposed method is based upon a configuration constituted by two 1-D filters in cascade and a feedback loop....

Venkat Ramachandran; Gargour, Christian S.; Ramachandran, Ravi P.

2007-01-01

143

Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

Rathod, K D; Natarajan, Vasant

2013-01-01

144

Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

Digital Repository Infrastructure Vision for European Research (DRIVER)

We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{1...

Rathod, K. D.; Singh, Pushpander; Natarajan, Vasant

2013-01-01

145

Dissipative Quantum Dynamics of Bosonic Atoms in a Shallow 1D Optical Lattice

International Nuclear Information System (INIS)

We theoretically study the dipolar motion of bosonic atoms in a very shallow, strongly confined 1D optical lattice using the parameters of the recent experiment [C. D. Fertig et al., Phys. Rev. Lett. 94, 120403 (2005)]. We find that, due to momentum uncertainty, a small, but non-negligible, atom population occupies the unstable velocity region of the corresponding classical dynamics, resulting in the observed dissipative atom transport. This population is generated even in a static vapor, due to quantum fluctuations which are enhanced by the lattice and the confinement, and is not notably affected by the motion of atoms or finite temperature

2005-09-09

146

System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

Digital Repository Infrastructure Vision for European Research (DRIVER)

The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the o...

Kulla, P.; Sevcik, P.; Chrenek, M.; Misun, J.

1993-01-01

147

P10-S A Novel Protein Database Search Algorithm for 1D and 2D LC-MS Data

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel, “Ion Accounting” algorithm has been developed for protein identification using time-resolved, LC-MSE data from 1D and 2D LC-MS experiments. The data from a 1D LC-MS analysis generate a series of precursor-product tables that are initially queried against a protein database using the “Ion Accounting” algorithm. Hereby each precursor and product is associated with only single peptide identification. The database search is a hierarchal process containing three modules. With the ...

Li, G.; Golick, D.; Dyson, B.; Silva, J. C.; Liu, H.; Vissers, J. P. C.; Gebler, J. C.; Gorenstein, M. V.; Geromanos, S. J.

2007-01-01

148

Coupling of Nod1D and HOTCHANNEL: static case; Acoplamiento de Nod1D y HOTCHANNEL: caso estatico

Energy Technology Data Exchange (ETDEWEB)

In this work the joining of the programs Nod1D and HOTCHANNEL, developed in the National Polytechnic Institute (IPN) and in the Electrical Research Institute (IIE) respectively is described. The first one allows to study the neutronic of a nuclear reactor and the second one allows to carry out the analysis of hot channel of a Boiling Water Reactor (BWR). Nod1 D is a program that it solves by nodal methods type finite element those diffusion equations in multigroup, and it is the static part of Nod Kin that it solves the diffusion equation in their time dependent part. For another side HOTCHANNEL is based on a mathematical model constituted by four conservation equations (two of mass conservation, one of motion quantity and one of energy), which are solved applying one discretization in implicit finite differences. Both programs have been verified in independent form using diverse test problems. In this work the modifications that were necessary to carry out to both for obtaining a coupled program that it provides the axial distribution of the neutron flux, the power, the burnup and the void fraction, among others parameters as much as neutronic as thermal hydraulics are described. Those are also mentioned limitations, advantages and disadvantages of the final product to which has been designated Nod1 D-HotChn. Diverse results for the Cycle 1 of the Laguna Verde Unit 1 reactor of the Nucleo electric central comparing them with those obtained directly with the CoreMasterPresto code are provided. (Author)

Gomez T, A.M. [IPN-ESFM, 07738 Mexico D.F. (Mexico); Ovando C, R. [IIE-Gcia. de Energia Nuclear, Cuernavaca, Morelos (Mexico)]. e-mail: rovando@iie.org.mx

2003-07-01

149

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The cellular localization of the ?1D-adrenergic receptor (?1D-AR is controversial. Studies in heterologous cell systems have shown that this receptor is expressed in intracellular compartments. Other studies show that dimerization with other ARs promotes the cell surface expression of the ?1D-AR. To assess the cellular localization in vascular smooth muscle cells, we developed an adenoviral vector for the efficient expression of a GFP labeled ?1D-AR. We also measured cellular localization with immunocytochemistry. Intracellular calcium levels, measurement of reactive oxygen species and contraction of the rat aorta were used as measures of functional activity. Results The adenovirally expressed ?1D-AR was expressed in intracellular compartments in human aortic smooth muscle cells. The intracellular localization of the ?1D-AR was also demonstrated with immunocytochemistry using an ?1D-AR specific antibody. RT-PCR analysis detected mRNA transcripts corresponding to the ?1A-?1B- and ?1D-ARs in these aortic smooth muscle cells. Therefore, the presence of the other ?1-ARs, and the potential for dimerization with these receptors, does not alter the intracellular expression of the ?1D-AR. Despite the predominant intracellular localization in vascular smooth muscle cells, the ?1D-AR remained signaling competent and mediated the phenylephrine-induced increases in intracellular calcium. The ?1D-AR also was coupled to the generation of reactive oxygen species in smooth muscle cells. There is evidence from heterologous systems that the ?1D-AR heterodimerizes with the ?2-AR and that desensitization of the ?2-AR results in ?1D-AR desensitization. In the rat aorta, desensitization of the ?2-AR had no effect on contractile responses mediated by the ?1D-AR. Conclusion Our results suggest that the dimerization of the ?1D-AR with other ARs does not alter the cellular expression or functional response characteristics of the ?1D-AR.

Hadley Robert W

2008-02-01

150

Phthalocyanine based 1D nanowires for device applications

1D nanowires (NWs) of Cu (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-Phthalocyanine (CuPc(OBu)8) molecule have been grown on different substrates by cost effective solution processing technique. The density of NWs is found to be strongly dependent on the concentration of solution. The possible formation mechanism of these structures is ?-? interaction between phthalocyanine molecules. The improved conductivity of these NWs as compared to spin coated film indicates their potential for molecular device applications.

Saini, Rajan; Mahajan, Aman; Bedi, R. K.

2012-06-01

151

Spectral function of the 1D Hubbard model

International Nuclear Information System (INIS)

For the one-dimensional (1D) Hubbard model, we extended the bosonization technique, away from half filling, in such a way that a general formula is obtained for the zero temperature equal-time single-particle Green function with validity over the whole doping range. With our method, we can calculate, for the first time, the one-body Green function and thus, the spectral function in both the Tomonaga-Luttinger and Luther-Emery universality classes. The method also gives a tool to determine the coefficients of the correlation functions which cannot be determined with previously used methods. ((orig.))

1994-04-01

152

D1-D5 black hole microstate counting from supergravity

Energy Technology Data Exchange (ETDEWEB)

We quantize the moduli space of regular D1-D5 microstates, directly from Type IIB SUGRA. The moduli space is parametrized by a smooth closed non-selfintersecting curve in four dimensions, and we derive that the components of the curve satisfy chiral boson commutation relations, with the correct value of the effective Planck constant previously conjectured using U-duality. We use the Crnkovic-Witten-Zuckerman covariant quantization method, previously used to quantize the 'bubbling AdS' geometries, combined with a certain new 'consistency condition' which allows us to reduce the computation to quantizing perturbations around the plane wave.

Rychkov, Vyacheslav S. [Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

2006-01-15

153

D1-D5 black hole microstate counting from supergravity

International Nuclear Information System (INIS)

We quantize the moduli space of regular D1-D5 microstates, directly from Type IIB SUGRA. The moduli space is parametrized by a smooth closed non-selfintersecting curve in four dimensions, and we derive that the components of the curve satisfy chiral boson commutation relations, with the correct value of the effective Planck constant previously conjectured using U-duality. We use the Crnkovic-Witten-Zuckerman covariant quantization method, previously used to quantize the 'bubbling AdS' geometries, combined with a certain new 'consistency condition' which allows us to reduce the computation to quantizing perturbations around the plane wave

2006-01-01

154

Nonultralocal Quantum Algebra and 1D Anyonic Quantum Integrable Models

International Nuclear Information System (INIS)

Applying braided Yang-Baxter equation quantum integrable and Bethe ansatz, solvable 1D anyon lattice and field models are constructed. Along with known models we discover novel lattice anyon and q-anyon models as well as nonlinear Schoedinger equation (NLS) and the derivative NLS anyon quantum field models, N-particle sectors of which yield the well-known anyon gases, interacting through ? and derivative ? function potentials. As a byproduct we discover a new anyon quantum group Hopf algebra with unusual braided multiplication. (author)

2010-01-01

155

Nanofluidic sustainable energy conversion using a 1D nanofluidic network.

We propose a 1-dimensional (1D) nanofluidic energy conversion device by implementing a surface-patterned Nafion membrane for the direct energy conversion of the pressure to electrical power. By implementing a -200-nm-thick nano-bridge with a 5-nm pore size between two microfluidic channels, we acquired an effective streaming potential of 307 mV and output power of 94 pW with 0.1 mM KCI under pressure difference of 45 MPa. The experimental results show both the effects of applied pressure differences and buffer concentrations on the effective streaming potential, and are consistent with the analytical prediction. PMID:24734635

Kim, Sang Hui; Kwak, Seungmin; Han, Sung Il; Chun, Dong Won; Lee, Kyu Hyoung; Kim, Jinseok; Lee, Jeong Hoon

2014-05-01

156

Spatial coherence of polaritons in a 1D channel

Energy Technology Data Exchange (ETDEWEB)

We analyze time evolution of spatial coherence of a polariton ensemble in a quantum wire (1D channel) under constant uniform resonant pumping. Using the theoretical approach based on the Lindblad equation for a one-particle density matrix, which takes into account the polariton-phonon and excitonexciton interactions, we study the behavior of the first-order coherence function g{sup 1} for various pump intensities and temperatures in the range of 1-20 K. Bistability and hysteresis in the dependence of the first-order coherence function on the pump intensity is demonstrated.

Savenko, I. G., E-mail: savenko.j@mail.ru [Russian Academy of Sciences, Academic University, Research and Education Center of Nanotechnologies (Russian Federation); Iorsh, I. V. [National Research University of Information Technologies, Mechanics and Optics (Russian Federation); Kaliteevski, M. A. [Russian Academy of Sciences, Academic University, Research and Education Center of Nanotechnologies (Russian Federation); Shelykh, I. A. [University of Iceland, Science Institute (Iceland)

2013-01-15

157

Feedback stabilization of a simplified 1d fluid- particle system

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the feedback stabilization of a simplified 1d model for a fluid-structure interaction system. The fluid equation is the viscous Burgers equation whereas the motion of the particle is given by the Newton's laws. We stabilize this system around a stationary state by using feedbacks located at the exterior boundary of the fluid domain. With one input, we obtain a local stabilizability of the system with an exponential decay rate of order $\\sigma<\\sigma_0$. An arbitrary order for the ...

Badra, Mehdi; Takahashi, Take?o

2013-01-01

158

A 1D Ising model for ripple formation

Energy Technology Data Exchange (ETDEWEB)

A 1D Ising model is shown to reproduce qualitatively the dynamics of ripple formation. The saltation effect is imposed using a Kawasaki dynamics and a pair interaction over some distance l. Within this model, the ripple state turns out to be metastable, in agreement with cellular automata simulations as well as recent underwater experiments. A dynamical phase diagram is obtained. A mean-field solution of the problem is given in terms of the ripple size. A mapping is then performed onto a 2D l x {infinity} static problem. (author)

Vandewalle, Nicolas [GRASP, Institut de Physique B5, Universite de Liege, Liege (Belgium); Laboratoire des Milieux Desordonnes et Heterogenes, Tour 13, Case 86, Paris (France); Galam, Serge [Laboratoire des Milieux Desordonnes et Heterogenes, Tour 13, Case 86, Paris (France)

2000-07-21

159

A 1-d Ising model for ripple formation

A 1-d Ising model is shown to reproduce qualitatively the dynamics of ripple formation. Saltation effect is imposed using a Kawasaki dynamics and a pair interaction over some distance l. Within this model, the ripple state turns out to be metastable in agreement with cellular automata simulations as well as recent under water experiments. A dynamical phase diagram is obtained. A mean-field solution of the problem is given in terms of the ripple size. A mapping is then performed onto a 2-dimensional l x infinity static problem.

Vandewalle, N; Vandewalle, Nicolas; Galam, Serge

2002-01-01

160

A 1D Ising model for ripple formation

International Nuclear Information System (INIS)

A 1D Ising model is shown to reproduce qualitatively the dynamics of ripple formation. The saltation effect is imposed using a Kawasaki dynamics and a pair interaction over some distance l. Within this model, the ripple state turns out to be metastable, in agreement with cellular automata simulations as well as recent underwater experiments. A dynamical phase diagram is obtained. A mean-field solution of the problem is given in terms of the ripple size. A mapping is then performed onto a 2D l x ? static problem. (author)

2000-07-21

161

Exotic prepotentials from D(-1)D7 dynamics

International Nuclear Information System (INIS)

We compute the partition functions of D(-1)D7 systems describing the multi-instanton dynamics of SO(N) gauge theories in eight dimensions. This is the simplest instance of the so called exotic instantons. In analogy with the Seiberg-Witten theory in four space-time dimensions, the prepotential and correlators in the chiral ring are derived via localization formulas and found to satisfy relations of the Matone type. Exotic prepotentials of SO(N) gauge theories with N = 2 supersymmetries in four-dimensions are also discussed.

2009-10-01

162

1D modeling on the material balance in CFB boiler

Energy Technology Data Exchange (ETDEWEB)

An 1D model of the circulating fluidized bed (CFB) boiler is developed specifically to predict the material balance in CFB boiler. This model emphasizes on the important factors that influence the ash balance in CFB boilers, such as ash formation, attrition and size reduction, residence time and segregation in dense bed. The corresponding sub-models are discussed in detail. In the simulation of a 135MWe CFB boiler in Zibo power plant, China, the parameters in mass balance model under full load operation, such as segregation parameters and axial decay constant, are optimized. The model can predict the mass balances at different operating loads in the same boiler.

Hairui Yang; Guangxi Yue; Xianbin Xiao; Junfu Lu; Qing Liu [Tsinghua University, Beijing (China). Department of Thermal Engineering

2005-10-15

163

Spatial coherence of polaritons in a 1D channel

International Nuclear Information System (INIS)

We analyze time evolution of spatial coherence of a polariton ensemble in a quantum wire (1D channel) under constant uniform resonant pumping. Using the theoretical approach based on the Lindblad equation for a one-particle density matrix, which takes into account the polariton-phonon and excitonexciton interactions, we study the behavior of the first-order coherence function g1 for various pump intensities and temperatures in the range of 1–20 K. Bistability and hysteresis in the dependence of the first-order coherence function on the pump intensity is demonstrated.

2013-01-01

164

A seismic waveform inversion algorithm is demonstrated for the estimation of elastic soil properties from one-dimensional downhole array recordings. For a given bedrock motion, scarcity of near-surface geotechnical information, error propagation and limited resolution of the continuum usually result in predictions of surface ground motion that poorly compare with low amplitude observations. This discrepancy is further aggravated for strong ground motion, associated with hysteretic, nonlinear, and potentially irreversible material deformations. Seismogram inversion is a nonlinear multi-parameter optimization problem. Traditional search techniques that use characteristics of the problem to determine the next sampling point (e.g. gradients, Hessians, linearity and continuity) are computationally efficient, yet limited to convex regular functions. As a result, they fail to identify the best fit solution in seismogram inversion problems, when the starting model is too far from the global optimal solution. On the other hand, stochastic search techniques (e.g. genetic algorithms, simulated annealing) have been shown to efficiently identify promising regions in the search space, but perform very poorly in a localized search. The proposed inversion technique is a two-step process, namely a genetic algorithm in the wavelet domain in series with a nonlinear least-square fit in the frequency domain; we thus improve the computational efficiency of the former, while avoiding the pitfalls of using local linearization techniques such as the latter for the optimization of multi-modal, discontinuous and non-differentiable functions. The parameters to be estimated are stepwise variations of the shear modulus, attenuation and density with depth, for horizontally layered media with refined near-surface discretization. Equality constrains are imposed on the vector of unknowns to bound the search space, based on the available soil investigation. For the genetic algorithm, the objective function is defined as the normalized cross-correlation between the observed data and the synthetics. We perform the inversion in the wavelet domain to allow for equal weighting of the information across all frequency bands. Since ground motion is non-stationary in time and frequency, a time-domain inversion would inevitably emphasize the larger amplitude signals. The process is repeated in series for a subset of the available borehole and surface waveform pairs, selected on the basis of signal quality. The mean estimated soil properties from the genetic algorithm are then used as a starting model for the local minimization scheme. The target function in this stage is the empirical transfer function in the frequency domain, estimated using the average spectral ratio between surface and borehole pairs. The global-local inversion technique can efficiently identify the optimal solution vicinity in the search space by means of the hybrid genetic algorithm, whereas the use of nonlinear least-square fit accelerates substantially the detection of the best fit model. The algorithm has been implemented in MATLAB, and inversion results are illustrated for stations in the Japanese strong motion borehole array Kik-Net, as well as for borehole stations in Southern California jointly operated by the California Integrated Seismic Network, the Southern California Earthquake Center, and the University of California at Santa Barbara.

Assimaki, D.; Tsuda, K.; Oakes, J.; Steidl, J.

2004-12-01

165

Directory of Open Access Journals (Sweden)

Full Text Available

A method for the generation of discrete-domain two-dimensional (2-D transfer functions possessing variable magnitude and contour characteristics is presented in this paper. The proposed method is based upon a configuration constituted by two 1-D filters in cascade and a feedback loop. Each of these 1-D filter is designed to have a monotonic magnitude frequency response. This is obtained by performing one or several integrations, either with respect to ? or ?2, of the denominator of a magnitude Butterworth low-pass frequency response and obtaining the corresponding modified transfer function. The variable characteristics in each domain are obtained by changing a multiplier either in the forward path or in the feedback path of the proposed general configuration. The use of a generalized bilinear transformation (GBT on the transfer functions obtained by the above mentioned method permits the generation of a large number of different characteristics. A certain number of these characteristics is examined in some detail. Illustrative examples are provided.

Ravi P. Ramachandran

2007-09-01

166

Intertwining relations for the deformed D1D5 CFT

The Higgs branch of the D1D5 system flows in the infrared to a two-dimensional mathcal{N} = left( {4,4} right) SCFT. This system is believed to have an "orbifold point" in its moduli space where the SCFT is a free sigma model with target space the symmetric product of copies of T 4; however, at the orbifold point gravity is strongly coupled and to reach the supergravity point one needs to turn on the four exactly marginal deformations corresponding to the blow-up modes of the orbifold SCFT. Recently, technology has been developed for studying these deformations and perturbing the D1D5 CFT off its orbifold point. We present a new method for computing the general effect of a single application of the deformation operators. The method takes the form of intertwining relations that map operators in the untwisted sector before application of the deformation operator to operators in the 2-twisted sector after the application of the deformation operator. This method is computationally more direct, and may be of theoretical interest. This line of inquiry should ultimately have relevance for black hole physics.

Avery, Steven G.; Chowdhury, Borun D.

2011-05-01

167

Nonlinear 1D DPCM image prediction using polynomial neural networks

This work presents a novel polynomial neural network approach to 1D differential pulse code modulation (DPCM) design for image compression. This provides an alternative to current tradition and neural networks techniques, by allowing the incremental construction of higher-order polynomials of different orders. The proposed predictor utilizes Ridge Polynomial Neural Networks (RPNs), which allow the use of linear and non-linear terms, and avoid the problem of the combinatorial explosion of the higher-order terms. In RPNs, there is no requirement to select the number of hidden units or the order of the network. Extensive computer simulations have demonstrated that the resulting encoders work very well. At a transmission rate of 1 bit/pixel, the 1D RPN system provides on average a 13 dB improvement in SNR over the standard linear DPCM and a 9 dB improvement when compared to HONNs. A further result of the research was that third-order RPNs can provide very good predictions in a variety of images.

Liatsis, Panos; Hussain, Abir J.

1999-03-01

168

A Diamagnetic Trap with 1D Camelback Potential

The ability to trap matter is of great importance in experimental physics since it allows isolation and measurement of intrinsic properties of the trapped matter. We present a study of a three dimensional (3D) trap for a diamagnetic rod in a pair of diametric cylindrical magnets. This system yields a fascinating 1D camelback potential along the longitudinal axis which is one of the elementary model potentials of interest in physics. This potential can be tailored by controlling the magnet length/radius aspect ratio. We developed theoretical models and verify them with experiments using graphite rods. We show that, in general, a camelback field or potential profile exists in between a pair of parallel linear dipole distribution. By exploiting this potential, we demonstrate a unique and simple technique to determine the magnetic susceptibility of the rod. This system could be further utilized as a platform for custom-designed 1D potential, a highly sensitive force-distance transducer or a trap for semiconductor...

Gunawan, Oki

2014-01-01

169

Numerical shock instability on 1D Euler equations

Numerical shock instabilities are deficiencies that may occur when predicting a shockwave in compressible flow computations. These deficiencies are usually present in shock capturing schemes with minimal numerical diffusion (i.e. Roe flux) when computing slowly moving shock problems, the hypersonic wall heating problem (Noh's problem) and even when simply predicting a steady state supersonic flow past a circular cylinder. For the supersonic flow past a cylinder, the predicted solution would normally consist of a pair of oblique shocks as opposed to the correct solution which is a bow-shock. Thus, the predicted thermodynamic quantities behind the shockwave are incorrect, compromising the overall flow predictions around the cylinder. This problem is also infamously known as the carbuncle phenomenon. The carbuncle problem has been around for more than 20 years yet there is no consensus within the literature of its true 'cause'. Recent studies have pointed out that the carbuncle may manifest itself in 2D, 1 1/2 D and even 1D shock structures. The current study will investigate the stability of 1D shock profiles based on the scalar and isothermal Euler equations using a numerical method based on Roe-flux. The results of this study will hopefully pave the way to better understand the root of the carbuncle phenomenon.

Wahi, Nadihah; Ismail, Farzad

2013-04-01

170

Reactions of HO2 with carbon monoxide and nitric oxide and of O/1 D/ with water.

Investigation of the reactions of the hydroperoxyl radical with carbon monoxide and nitric oxide in a static system, and reexamination of the reaction of O(1 D) with water. The HO2 radicals were generated by the photolysis of N2O at 2139 A in the presence of excess H2O or H2 and smaller amounts of CO and O2. The O(1 D) atoms produced from the photolysis of N2O react with H2O or with H2 to give OH radicals in the case of H2O or OH radicals and H atoms in the case of H2. With H2O, two OH radicals are produced for each O(1 D) removed at low pressures, but the OH yield drops as the pressure is raised. This drop is attributed to an insertion reaction which removes from 10 to 30% of the O(1 D) atoms at about 650 torr of H2O at 200 F. The OH radicals generated can react with either CO or H2 to produce H atoms, which then add to O2 to produce HO2. In the absence of NO, the HO2 radicals could react by two routes, while with NO present NO2 is produced in a long chain process.

Simonaitis, R.; Heicklen, J.

1973-01-01

171

Digital Repository Infrastructure Vision for European Research (DRIVER)

Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or...

Salmanowicz, Boles?aw P.; Monika Langner; Halina Wi?niewska; Barbara Apolinarska; Micha? Kwiatek; Lidia B?aszczyk

2013-01-01

172

1-D array of perforated diode neutron detectors

Energy Technology Data Exchange (ETDEWEB)

Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 {mu}m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with {sup 6}LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.

McNeil, Walter J. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: wjm4444@ksu.edu; Bellinger, Steven L.; Unruh, Troy C.; Henderson, Chris M.; Ugorowski, Phil; Morris-Lee, Bryce [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States); Taylor, Russell D. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [Kansas State University, Mechanical and Nuclear Engineering Department, Manhattan, KS 66506 (United States)], E-mail: mcgregor@ksu.edu

2009-06-01

173

1-D array of perforated diode neutron detectors

International Nuclear Information System (INIS)

Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 ?m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with 6LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.

2009-06-01

174

Invariant manifolds and stability: Some results for 1-D maps

International Nuclear Information System (INIS)

To give an analytic estimate of the stability domain of nonlinear systems, like large accelerators, has been a subjected of intense theoretical studies for many years. Up to now, even for the simple case of the one-dimensional Henon map, one could not determine the border of the stability domain using analytic tools. On the other hand this estimate can easily be found by tracking through the map. A promising new attempt is presented here, to estimate the dynamic aperture for the Henon map via following the invariant manifolds of its hyperbolic fixed point. The same technique is then applied to a different map and an attempt to generalize the method presented in this paper to generic 1-D polynomial maps is briefly discussed

1992-11-01

175

Effective slip boundary conditions for 1D periodic surfaces

In many applications it is advantageous to construct effective slip boundary conditions, which could fully characterize flow over patterned surfaces. Here we focus on laminar shear flows over smooth anisotropic surfaces with arbitrary periodic scalar slip $b(y)$, varying in only one direction. We derive general expressions for longitudinal and transverse components of the effective slip-length tensor, and show that they are affine being related by a simple formula \\[ b_{\\mathrm{eff}}^{\\bot}[b(y)/L] =\\frac{b_{\\mathrm{eff}%}^{\\parallel}[2b(y)/L]}{2}. \\] A remarkable corollary of this relation is that the flow along any direction of the 1D surface can be easily determined, once the longitudinal component of the effective slip tensor is found from the known spatially nonuniform scalar slip.

Asmolov, Evgeny S

2012-01-01

176

Point Charge Electric Field in 1D Model

The Point Charge Electric Field in 1D model investigates the electric field at various positions along a line, when there are either one or two charged particles on that line. The electric field is represented in two ways. First, there is a movable positive test charge that you can move along the line to sample the field at various locations - the direction of the force on that test charge is the same as the direction of the electric force on the test charge. The second way to represent the electric field is to plot a graph of the electric field as a function of position. For the graph, we define positive field as a field pointing to the right, and negative field as a field pointing to the left.

Duffy, Andrew

2009-10-21

177

Surface-Plasmon Assisted Exciton Transport in 1D Nanostructures

We consider effect of coupling between exciton propagating in a 1D-nanostructure (e.g., carbon nanotube) and localized surface plasmon modes induced by a metal nanoparticle located in close proximity to the nanostructure. Both regimes of weak and strong exciton-plasmon couplings are taken into account leading to the dressed exciton and plasmon states. In this representation, the dynamics of the dressed excitons is mapped on the impurity scattering problem. The analysis of the scattering matrix indicates that the surface-plasmon modes lead to the exciton intraband scattering and possibility to form localized states within the exciton band gap. Surface plasmon induced exciton radiation pattern and the radiative and non-radiative decay rates are calculated and their dependence on the exciton-plasmon coupling is analyzed.

Cherqui, Charles; Dunlap, David; Piryatinski, Andrei

2013-03-01

178

Normal Modes on 1D Monatomic Lattice Model

The Normal Modes on 1D Monatomic Lattice Model shows the motion and the dispersion relation of N identical ions of mass M separated by a lattice distance a. Ionic vibrations in a crystal lattice form the basis for understanding many thermal properties found in materials. These vibrations are described as displacement waves traveling through the lattice. These vibrational modes can also be described as bosonic particles called phonons which have quantized energy in much the same way photons do for light. Using a spring model for the inter-ionic interactions, the dispersion relation between the vibrational frequencies and the allowed wave vectors can be analytically solved for the simple one dimensional case. It is sometimes difficult for students to visualize these modes of vibration and how they relate to the resulting ionic motions in the underlying crystal lattice. This simulation facilitates the understanding of the analytical solution by graphically representing these modes. The analytical form of the dispersion relation is shown along with the allowed normal mode points. Based on the chosen normal mode, the motion of the ions as a function of time is displayed to help visualize the mode. It is easy to see how the chosen mode affects the ion motions from unit cell to unit cell. The Normal Modes on 1D Monatomic Lattice Model was developed by Richard Charles Andrew using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed.

Andrew, Richard C.

2013-10-08

179

75 FR 11072 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines

...turboshaft engines. That AD requires...checks of the gas generator 2nd stage turbine...checks of the gas generator 2nd stage turbine...turboshaft engines that do not...reports that in engines that do not...new cases of gas generator 2nd stage...

2010-03-10

180

CD1d Activation and Blockade: A New Antitumor Strategy1

Digital Repository Infrastructure Vision for European Research (DRIVER)

CD1d is expressed on APCs and presents glycolipids to CD1d-restricted NKT cells. For the first time, we demonstrate the ability of anti-CD1d mAbs to inhibit the growth of different CD1d-negative experimental carcinomas in mice. Anti-CD1d mAbs systemically activated CD1d+ APC, as measured by production of IFN-? and IL-12. Tumor growth inhibition was found to be completely dependent on IFN-? and IL-12 and variably dependent on CD8+ T cells and NK cells, depending upon the tumor model examined...

Teng, Michele W. L.; Yue, Simon; Sharkey, Janelle; Exley, Mark A.; Smyth, Mark J.

2009-01-01

181

Hepatic CD1d-restricted and natural killer T-cell populations are heterogeneous. Classical 'type 1' ?-galactosylceramide-reactive CD1d-restricted T cells express 'invariant' TCR? ('iNKT'). iNKT dominating rodent liver are implicated in inflammation, including in hepatitis models. Low levels of iNKT are detected in human liver, decreased in subjects with chronic hepatitis C (CHC). However, high levels of human hepatic CD161(±) CD56(±) noninvariant pro-inflammatory CD1d-restricted 'type 2' T cells have been identified in vitro. Unlike rodents, healthy human hepatocytes only express trace and intracellular CD1d. Total hepatic CD1d appears to be increased in CHC and primary biliary cirrhosis. Direct ex vivo analysis of human intrahepatic lymphocytes (IHL), including matched ex vivo versus in vitro expanded IHL, demonstrated detectable noninvariant CD1d reactivity in substantial proportions of HCV-positive livers and significant fractions of HCV-negative livers. However, ?-galactosylceramide-reactive iNKT were detected only relatively rarely. Liver CD1d-restricted IHL produced IFN?, variable levels of IL-10 and modest levels of Th2 cytokines IL-4 and IL-13 ex vivo. In a novel FACS assay, a major fraction (10-20%) of hepatic T cells rapidly produced IFN? and up-regulated activation marker CD69 in response to CD1d. As previously only shown with murine iNKT, noninvariant human CD1d-specific responses were also augmented by IL-12. Interestingly, CD1d was found selectively expressed on the surface of hepatocytes in CHC, but not those CHC subjects with history of alcohol usage or resolved CHC. In contrast to hepatic iNKT, noninvariant IFN?-producing type 2 CD1d-reactive NKT cells are commonly detected in CHC, together with cognate ligand CD1d, implicating them in CHC liver damage. PMID:23808994

Yanagisawa, K; Yue, S; van der Vliet, H J; Wang, R; Alatrakchi, N; Golden-Mason, L; Schuppan, D; Koziel, M J; Rosen, H R; Exley, M A

2013-08-01

182

DISCOLORATION OF THE WETTED SURFACE IN THE 6.1D DISSOLVER

Energy Technology Data Exchange (ETDEWEB)

During a camera inspection of a failed coil in the 6.1D dissolver, an orange discoloration was observed on a portion of the dissolver wall and coils. At the request of H-Canyon Engineering, the inspection video of the dissolver was reviewed by SRNL to assess if the observed condition (a non-uniform, orange-colored substance on internal surfaces) was a result of corrosion. Although the dissolver vessel and coil corrode during dissolution operations, the high acid conditions are not consistent with the formation of ferrous oxides (i.e., orange/rust-colored corrosion products). In a subsequent investigation, SRNL performed dissolution experiments to determine if residues from the nylon bags used for Pu containment could have generated the orange discoloration following dissolution. When small pieces of a nylon bag were placed in boiling 8 M nitric acid solutions containing other components representative of the H-Canyon process, complete dissolution occurred almost immediately. No residues were obtained even when a nylon mass to volume ratio greater than 100 times the 6.1D dissolver value was used. Degradation products from the dissolution of nylon bags are not responsible for the discoloration observed in the dissolver.

Rudisill, T.; Mickalonis, J.; Crapse, K.

2013-12-18

183

Prognostic value of PPM1D in 800 gastric cancer patients.

Protein phosphatase magnesium?dependent 1 delta (PPM1D) has recently been associated with tumor biology. However, the expression pattern and clinical significance of PPM1D in gastric cancer (GC) have yet to be elucidated. The present study aimed to investigate the clinical and prognostic significance of PPM1D in GC. PPM1D expression was assessed in 800 patients with GC using immunohistochemistry and tissue samples were divided into a PPM1D?positive and ?negative group. The correlation between PPM1D expression and clinicopathological parameters or prognosis was investigated. PPM1D expression was significantly higher in GC tissue than in adjacent normal tissue (48 versus 9.5%; P<0.001). PPM1D positivity was significantly correlated with nodal status, distant metastasis and vascular invasion. Survival analysis indicated that the five?year survival rate in the PPM1D?positive group was significantly lower than that in the PPM1D?negative group (41 versus 72%; p=0.0012). Furthermore, the association between PPM1D positivity and survival rate was still significant following regulation of other prognostic markers in a multivariate analysis [hazard ratio (HR), 6.572; 95% confidence interval (CI), 3.108?13.471; P=0.0018]. In conclusion, the present study suggested that PPM1D positivity is associated with GC invasion and metastasis, and proposed PPM1D positivity as an indicator of unfavorable prognosis in patients with GC. PMID:24788664

Ma, Dan; Zhang, Chao-Jun; Chen, Zu-Lin; Yang, Hua

2014-07-01

184

We have been developing an accurate and efficient numerical scheme, which uses the finite-difference method (FDM) in spherical coordinates, for the computation of global seismic wave propagation through laterally heterogeneous realistic Earth models. In the field of global seismology, traditional axisymmetric modeling has been used widely as an efficient approach since it can solve the 3-D elastodynamic equation in spherical coordinates on a 2-D cross-section of the Earth, assuming structures to be invariant with respect to the axis through the seismic source. However, it has the severe disadvantages that asymmetric structures about the axis cannot be incorporated and the source mechanisms with arbitrary shear dislocation have not been attempted for a long time. Our scheme is based on the framework of axisymmetric modeling but has been extended to treat asymmetric structures, arbitrary moment-tensor point sources, anelastic attenuation, and the Earth center which is a singularity of wave equations in spherical coordinates. All these types of schemes which solve 3-D wavefields on a 2-D model cross-section are classified as 2.5-D modeling, so we have named our scheme the spherical 2.5-D FDM. In this study, we compare synthetic seismograms calculated using our FDM scheme with three-component observed long-period seismograms including data from stations newly installed in Antarctica in conjunction with the International Polar Year (IPY) 2007-2008. Seismic data from inland Antarctica are expected to reveal images of the Earth's deep interior with enhanced resolution because of the high signal-to-noise ratio and wide extent of this region, in addition to the rarity of sampling paths along the rotation axis of the Earth. We calculate synthetic seismograms through the preliminary reference earth model (PREM) including attenuation using a moment-tensor point source for the November 9, 2009 Fiji earthquake. Our results show quite good agreement between synthetic and observed seismograms, which indicates the accuracy of observations in the Antarctica, as well as the feasibility of the spherical 2.5-D modeling scheme.

Toyokuni, Genti; Takenaka, Hiroshi; Kanao, Masaki; Wiens, Douglas A.; Nyblade, Andrew

2012-07-01

185

Hemi-omnidirectional lasing from a cholesteric liquid crystal layer on a 1D photonic crystal film

Energy Technology Data Exchange (ETDEWEB)

We herein report on a hybrid photonic band gap (PBG) system, which was fabricated using a cholesteric liquid crystal (CLC) layer on a 1-dimensional (1D) photonic crystal (PC) film, i.e., hybrid 'CLC/1D PC'. The CLC layer is made of nematic liquid crystal monomers embedded in polymeric helical CLC networks, thereby exhibiting a field-induced reorientational undulation of the helical axis. It is shown that intensity-controllable circularly polarized laser emissions may be generated at the wavelength of the high-energy band edge mode of the CLC layer in the dye-doped 'CLC/1D PC' PBG structure. The handedness of the lasing light corresponds to the handedness of the CLC layer used. Moreover, the direction of propagation of laser emissions could be manipulated from uni- to hemi-omnidirectional for the hybrid 'CLC/1D PC' PBG structure by applying an electric field.

Park, Byoungchoo [Kwangwoon University, Seoul (Korea, Republic of)

2011-09-15

186

Nonlinear electrical conductivity in a 1D granular medium

We report the observation of the electrical transport within a chain of metallic beads (probably slightly oxidized) under applied stress. We observe a transition from an isolating to a conductive state as the applied current is increased. The voltage-current U-I characteristics is found to be symmetric with an ohmic reversible component continuously followed by a nonlinear hysteretic part saturating to a critical voltage of 0.4 V per contact. This 1D experiment allows to understand the phenomena linked to this conduction transition such as the "Branly effect'' by focusing on the nature of the contacts instead of the structure of the granular network as usual. We show that this transition comes from an electro-thermal coupling due to the local heating of the microcontact up to their melting near 1000 degre C (even for so low voltage as 0.4 V). Based on this self-regulated temperature mechanism, an analytical expression for the nonlinear U-I back trajectory is derived in very good agreement with the data. It al...

Falcon, E; Creyssels, M; Falcon, Eric; Castaing, Bernard; Creyssels, Mathieu

2004-01-01

187

Dynamical tunneling-like effects in 1D classical systems

International Nuclear Information System (INIS)

Dynamical tunneling occurs when a particle tunnels between two distinct classically trapped periodic regions of classical phase space that are not separated by a potential barrier. Although the dynamical tunneling has been observed in many multi-dimensional Hamiltonian systems, it has not been observed in 1D systems described by a single potential. In this paper, we show that classical trajectories of real potentials such as V1(x) = x4 exhibit dynamical tunneling-like behavior when energy or time is complex. It was found that the doubly periodic nature of the Jacobian elliptic functions is responsible for this dynamical tunneling-like behavior. The time spent in one region by the tunneling trajectory before crossing over to the other is found to be proportional to |(E03/4)/?E, where total energy E = E0 + i?E with E0 2(x) = x4 + (1 + i)x show evidence of dynamical tunneling even for real energies. The role of complex time in dynamical tunneling is discussed. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Quantum physics with non-Hermitian operators’. (paper)

2012-11-09

188

Quantum Heat Engines; Multiple-State 1D Box System

Directory of Open Access Journals (Sweden)

Full Text Available We evaluate quantum Otto, Diesel and Brayton cycles employing multiple-state 1D box system instead of ideal gas filled cylinder. The work and heat are extracted using the change in the expectation of Hamiltonian of the system which leads to the first law of thermodynamics to quantum system. The first law makes available to redefine the force which is in fact not well defined in a quantum mechanical system and then it is applied to define the quantum version of thermodynamic processes, i.e. isobaric, isovolume and adiabatic. As the results, the efficiency of quantum Otto engine depends only on the compression ratio and will be higher than the efficiency of quantum Diesel which can decrease by the widening of expansion under isobaric process. The efficiency of quantum Brayton engine may reach maximum on certain combination between the wide of box under isobaric expansion and compression, under certain conditions. The amount of levels participated in the quantum heat engine system will potentially reduce the performance of the quantum heat cycles consisting isobaric process, but it can be resisted using isobaric process controller.

Eny Latifah

2013-08-01

189

An Efficient Algorithm for approximating 1D Ground States

The most commonly used algorithm for approximating ground states of 1D quantum systems is the Density Matrix Renormalization Group approach (DMRG). DMRG works very well in practice, but there is no proved guarantee for when it works, and it is easy to come up with counter examples in which it gets stuck in a local minimum. In this paper we describe an efficient classical algorithm which finds a good approximation of the ground state of a one dimensional quantum system, under the condition that such a good approximation exists by a Matrix Product State (MPS) of constant bond dimension (BD). In case the guarantee is only for a good approximation by an MPS of logarithmic BD, the algorithm becomes somewhat less efficient: it will take quasi-polynomial time to find the approximation. The assumption that the BD is small seems to hold for many interesting physical systems. We note that if the bound on the BD is polynomial, a polynomial time algorithm is unlikely to exist, since it is known that the problem of findin...

Aharonov, Dorit; Irani, Sandy

2009-01-01

190

1D nonnegative Schrodinger operators with point interactions

Directory of Open Access Journals (Sweden)

Full Text Available Let $Y$ be an infinite discrete set of points in $dR$,satisfying the condition $inf{|y-y'|,; y,y'in Y, y'ey}>0.$ In the paper we prove that the systems${delta(x-y}_{yin Y}, ;{delta'(x-y}_{yin Y},{delta(x-y,;delta'(x-y}_{yin Y}$ {form Riesz} bases in the corresponding closed linear spans in the Sobolev spaces $W_2^{-1}(dR$ and $W_2^{-2}(dR$. As an application, we prove the transversalness of the Friedrichs and Kreui n nonnegative selfadjoint extensions of the nonnegative symmetric operators $A_0$, $A'$, and $H_0$ defined {as restrictions} of the operator $A =-frac{ d^2}{ dx^2},$ $dom (A=W^2_2(dR${to} the linear manifolds $dom (A_0=left{ finW_2^2(mathbb{R}colon f(y=0,; yin Y ight}$, $dom(A'={ gin W_2^2(mathbb{R}colon g'(y=0,; yin Y },$ and$dom (H_0=left{fin W_2^2(mathbb{R}colonf(y=0,;f'(y=0,; yin Y ight}$, respectively. Using thedivergence forms, the basic nonnegative boundary triplets for$A^*_0$, $A'^*$, and $H^*_0$ are constructed.

Yu. G. Kovalev

2013-07-01

191

The influence of dissipation in a 1D quantum metamaterial

International Nuclear Information System (INIS)

Quantum metamaterials consist of quantum coherent structures made up of artificial atoms connected by a transmission medium. In this work we investigate the effects of decoherence in both the transmission medium and the artificial atom using a fully quantum mechanical model. We consider a prototypical solid state 1D quantum metamaterial, i.e. a superconducting flux qubit coupled to a transmission line section on resonance. An initially excited qubit is found to effectively pump a propagating coherent pulse and increase the average output power of the transmission line. Evidence of entanglement between the qubit and the transmission line with a propagating coherent pulse is also demonstrated. This signature behaviour is found to still be evident when a level of decoherence in line with that found in typical experiments is introduced into the transmission line section as well as the qubit. Increasing levels of decoherence, particularly in the qubit, are shown to be dangerous as they destroy the quantum correlations between the qubit and the propagating field. (paper)

2013-08-01

192

Nanowires and 1D arrays fabrication: An overview

International Nuclear Information System (INIS)

Since the discovery of M41S materials family in 1992, some special features like aligned pores perpendicularly to the substrate surface and long range order, have been looked for with great interest for many applications of these kind of nanomaterials. The growth of thin films displaying meso- and nano-porous structures have attracted the attention of many research groups in the last decade and, with that aim several techniques such as: MBE, CVD, AFM, ion beam lithography, etc., have been used. On the other hand, a lot of down-top techniques, particularly those in which, self-assembly processes play a relevant role in the growth mechanisms of that nanostructures have been reported. Among them, electrochemical techniques constitute one of the most used to fabricate highly ordered nanostructures to be used as templates for replicating other nanostructured materials and for growing functionalized material arrays. In this paper, a brief overview on the nanofabrication techniques is done mainly of those related with the nanowires and, in general, 1D nanostructures fabrication. In addition, we show some results on ordered and disordered nanoporous anodic alumina membranes (AAM) and anodic titania membranes (ATM), respectively. Besides some functionalized systems based on these membranes used as templates are presented such as, magnetic nanowire arrays, biosensors, and carbon nanotubes. The potentiality of these systems for applications on diverse field, such as, nanoelectronic, magneto-optic, biotechnology and optoelectronic is demonstrated

2006-01-20

193

XBWR, 1-D Xe Transients for BWR in Axial Geometry

International Nuclear Information System (INIS)

1 - Nature of the physical problem solved: 1-D xenon transients for BWRs in axial geometry. 2 - Method of solution: XBWR couples a two group neutron diffusion calculation in plane geometry with a two phase flow cooling channel calculation and the heat conduction in the typical fuel rod. The program allows following any given power time schedule, such as shut-down and restart, day-night power variation etc., while the reactor is being kept critical by control rod movement, variable poisoning of the core, or coolant flow recirculation rate. The xenon and iodine concentrations variation is evaluated pointwise (up to 100 points) by analytical solution for successive fixed time steps. At the end of each time step a new distribution of fluxes, power, voids and temperatures is obtained, which is consistent with the reactor critical condition as it is got by variation of the control parameter taking into account the feedbacks. The new flux distribution is used as input for xenon and iodine concentrations evolution in the next time step

1980-01-01

194

Chaotic Encryption Scheme Using 1-D Chaotic Map

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes three different chaotic encryption methods using 1-D chaotic map known as Logistic map named as Logistic, NLFSR and Modified NLFSR according to the name of chaotic map and non-linear function involved in the scheme. The designed schemes have been crypt analyzed for five different methods for testing its strength. Cryptanalysis has been performed for various texts using various keys selected from domain of key space. Logistic and NLFSR methods are found to resist known plaintext attack for available first two characters of plaintext. Plaintext sensitivity of both methods is within small range along with medium key sensitivity. Identifiability for keys of first two of the scheme has not been derived concluding that methods may prove to be weak against brute-force attack. In the last modified scheme avalanche effect found to be improved compared to the previous ones and method is found to resist brute-force attack as it derives the conclusion for identifiability.

Mina Mishra

2011-07-01

195

Synthesis and properties of a few 1-D cobaltous fumarates

International Nuclear Information System (INIS)

Metal fumarates are often studied in the context of metal organic framework solids. Preparation, structure and properties of three cobalt(II) fumarates, viz. [Co(fum)(H2O)4]·H2O 1, [Co(fum)(py)2(H2O)2] 2, and [Co(fum)(4-CNpy)2(H2O)2] 3 (fum=fumarate, py=pyridine, 4-CNpy=4-cyanopyridine) are described. All three are chain polymers involving bridging fumarato ligands between each pair of octahedral Co(II) centres, but while the first one is zigzag in structure, the latter two are linear. Indexed powder X-ray diffraction patterns, solid state electronic spectra and magnetic properties of the species are reported. Thermal decomposition behaviour of the compounds suggests that they may be suitable as precursors to make Co3O4 via pyrolysis below 600 °C. - Graphical abstract: Structure and properties of three chain-polymeric cobalt(II) fumarates are described. Highlights: ? Three fumarate bridged 1-D coordination polymers of cobalt(II) are reported. ? While Co(II) fumarate pentahydrate is zigzag, the species having both pyridine and water as co-ligands are linear in structure. ? Prominent lines in the powder X-ray diffraction patterns have been indexed. ? Thermal decomposition of the species yields Co3O4 as the final product.

2012-08-01

196

Free surface water wave 1-D LBGK predictions

The performance of a single phase free surface lattice Boltzmann (LB) solver is investigated. The lattice-BGK (LBGK) model explores the free surface behavior with a focus on non-overturning water waves. The discretized equations are based on shallow water wave theory in viscous flow. Therefore, only flows with horizontal velocity dominating free surface waves is applicable. The solutions on uniform grids implement an elastic-collision scheme assuming slip boundaries at the tank walls. Simulations are carried out in horizontal base-excited square tanks. The forcing amplitude and the tank aspect ratios of are kept constant while the forcing frequency is varied off- and near resonance. At this water depth, the free surface was observed to slosh in a first sway mode initially; however, the following cycles would typically consist of traveling waves or bores. The flow typically remained 1-D in resonance cases except at the bore front and near the walls. The LB experiments are limited to flow simulations of weak bores which occurred near resonance with forcing amplitude in the order of . The LB solutions were in good agreement with a Riemann solver and agreed fairly well with experimental data.

Frandsen, J. B.

2006-07-01

197

A Survey on Just-Non-𝔛 Groups

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let 𝔛 be a class of groups. A group which does not belong to 𝔛 but all of whose proper quotient groups belong to 𝔛 is called just-non-𝔛 group. The present note is a survey of recent results on the topic with a special attention to topological groups.

Daniele Ettore Otera; Russo, Francesco G.

2010-01-01

198

A Survey on Just-Non-𝔛 Groups

Directory of Open Access Journals (Sweden)

Full Text Available Let 𝔛 be a class of groups. A group which does not belong to 𝔛 but all of whose proper quotient groups belong to 𝔛 is called just-non-𝔛 group. The present note is a survey of recent results on the topic with a special attention to topological groups.

Francesco G. Russo

2010-01-01

199

System for Digital 1D-Image Processing with 1024 Pixel CCD Sensor

Directory of Open Access Journals (Sweden)

Full Text Available The conception of system for digital 1D-images processing with digital CCD camera is presented. The system is created from these three basic parts: the digital CCD camera with linear image sensor CCD L133C, 8-bit interface and a personal computer. The scanning digital CCD camera generated a video signals, which are processed in the analog signal processor. The output signal is continually converted to 8-bit data words in A/D converter. This data words maybe transfer over a bus driver to the operation memory of personal computer, by setting one of the three work regimes of digital CCD camera. Some application possibilities and basic technical parameters of this system are given.

J. Misun

1993-11-01

200

Normal Modes on 1D Diatomic Lattice Model

The Normal Modes on 1D Diatomic Lattice Model shows the motion and the dispersion relation of N diatomic unit cells. Ionic vibrations in a crystal lattice form the basis for understanding many thermal properties found in materials. These vibrations are described as displacement waves traveling through the lattice. These vibrational modes can also be described as bosonic particles called phonons which have quantized energy in much the same way photons do for light. Using a spring model for the inter-ionic interactions, the dispersion relations between the vibrational frequencies and the allowed wave vectors can be analytically solved for the simple one dimensional case with a two atom basis. It is sometimes difficult for students to visualize these modes of vibration and how they relate to the resulting ionic motions in the underlying crystal lattice. This simulation facilitates the understanding of the analytical solutions by graphically representing these modes. The analytical forms of the two dispersion relations (the optical and acoustic branches) are shown along with the allowed normal mode points. Based on the chosen normal mode, the motion of the ions as a function of time is displayed to help visualize the mode. It is easy to see how the chosen mode affects the ion motions inside a unit cell as well as the motions from unit cell to unit cell. Also, the optical and acoustic motions can be readily compared. This model was developed by Richard Charles Andrew using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed.

Andrew, Richard C.

2013-10-14

201

Simplified 1D modelling of the HGA test

International Nuclear Information System (INIS)

Document available in extended abstract form only. The HGA test is located in the Mont Terri Rock Laboratory (Switzerland). It consists of a horizontal borehole of 1.00 m of diameter and 13.00 m of length excavated in the ultra-low permeable Opalinus clay. During the tunnel drilling, the Opalinus clay near the tunnel wall was damaged, giving rise to an EDZ (Excavation Damaged Zone) around the tunnel. A steel liner was placed along the 6.00 m close to the tunnel mouth in order to guarantee the stability. The last 4.00 m at the tunnel end were backfilled with gravel. Along the remaining 3.00 m, an inflatable rubber packer of 1.00 m in diameter, was installed and inflated, thereby compressing the EDZ that was created during the tunnel excavation. The test section was filled with de-aired water and care was taken in order to eliminate the air from this tunnel section. Subsequently, a series of water and gas injection tests were carried out with varying mega-packer pressure, whereby water or gas was injected into the test section and, due to the very low permeability of the intact Opalinus clay, forced to flow back along the EDZ. In order to model the water and gas flow through the EDZ, we have followed a two-track approach. On the one hand, a 2D axisymmetric numerical model using code-bright has been made. On the other hand, a 1D analytical-numerical model has been developed and implemented in an Excel spreadsheet, whereby the field equations defined on a 1D geometrical domain are numerically solved using the finite element method. The 1D model has been used in order to calibrate the 2D axisymmetric model. Both the Opalinus clay and the EDZ will be considered to be porous media, with an incompressible solid phase (clay), an incompressible liquid phase (water and air) and a gas phase (water and air). The properties of the liquid phase will be assumed to be independent of the concentration of dissolved air and the gas phase will be assumed to be a mixture of dry air and water vapour, both assumed to be ideal gases, such that Dalton's law holds. Exchanges of both species water and species air between the liquid phase and the gas phase will be allowed, but it will be assumed that they are always in equilibrium, defined by the psychrometric and Henry's laws. It will be assumed that motions are slow so that terms involving accelerations and products of velocities may be neglected. Motion of the liquid phase and of the gas phase will be described by generalisations of Darcy's laws appropriate to unsaturated porous media and motion of the species water and the species air in the liquid phase and in the gas phase will be described by Fick's laws. In the Opalinus clay the intrinsic permeability will be assumed to be constant, but in the EDZ it will be assumed that it depends on the volumetric deformation of the solid skeleton via an aperture-based cubic law. A generalised form of Terzaghi's effective stress principle will be assumed to hold both in saturated and in unsaturated conditions. The constitutive laws for generalised effective stress both the Opalinus clay and the EDZ will be assumed to be given by isotropic linear elasticity. A water retention curve will govern the degree of saturation of the porous medium and, in particular, the transition between saturated and unsaturated states. Finally, it will be assumed that temperature remains constant everywhere. By combining the balance equations, the equilibrium restrictions and the constitutive relations, we get the field equations, that with suitable initial and boundary conditions allow to determine the unknown functions of the space position and time. In the considered case of the HGA test, we have considered simplifying assumptions that greatly reduce the complexity of the field equations. Mechanical assumptions: (1) there is axisymmetry about the tunnel axis; (2) there are no volume forces; and (3) slices z = const move independently and in plane strain. Hydraulic assumptions: (1) there is axisymmetry about the tunnel axis; and (2) there are no volume forces. Furthermore, on

2012-10-01

202

CD1d expression on and regulation of murine hematopoietic stem and progenitor cells

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the present study, surface CD1d, which is involved in immune cell interactions, was assessed for effects on hematopoiesis. Mouse BM hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) express CD1d. The numbers and cycling status of HPCs in the BM and spleen of different strains of cd1d?/? mice were enhanced significantly, suggesting that CD1d is a negative regulator of HPCs. In support of this, CD1d was required for the SCF and Flt3 ligand synergistic enhancement ...

Broxmeyer, Hal E.; Christopherson, Kent; Hangoc, Giao; Cooper, Scott; Mantel, Charlie; Renukaradhya, Gourapura J.; Brutkiewicz, Randy R.

2012-01-01

203

CD1d-restricted NKT cells comprise an innate-like T cell population that exerts significant influence over early events in the developing immune response. The frequency of NKT cells is highly variable in humans and in mice, but the basis for this variability remains unclear. In this study, we report a striking deficiency of type I NKT cells in the wild-derived inbred strains PWD/PhJ, SPRET/EiJ, and CAST/EiJ. Investigation of the underlying basis for the lack of type I NKT cells revealed that one strain, PWD/PhJ, exhibited a significant impairment in thymocyte and splenocyte CD1d gene and protein expression. Accordingly, both thymocytes and bone marrow-derived dendritic cells from PWD mice exhibited a significant impairment in the ability to present ?-galactosylceramide to NKT cells. The impaired PWD CD1d gene expression was due to impaired CD1d promoter activity. Fine-mapping of the promoter activity revealed that two single nucleotide substitutions at positions -331 and -164 in the proximal promoter were each sufficient to account for the diminished PWD CD1d promoter activity. Examination of the strain distribution pattern of these polymorphisms revealed that, of 19 strains analyzed, only PWD and PWK mice possessed both CD1d promoter polymorphisms. A subsequent examination of the PWK strain revealed that it also exhibited impaired thymocyte CD1d expression and very low numbers of NKT cells. Taken together, these results provide new insight into the control of CD1d gene expression, and they have implications for the evolution of CD1d and type I NKT cells. PMID:24307737

Borg, Zachary D; Benoit, Patrick J; Lilley, Graham W J; Aktan, Idil; Chant, Alan; DeVault, Victoria L; Rincon, Mercedes; Boyson, Jonathan E

2014-01-01

204

Anti-tumor Potential of Type-I NKT cells against CD1d-positive and CD1d-negative Tumors in Humans

Digital Repository Infrastructure Vision for European Research (DRIVER)

V?24-invariant Natural Killer T cells (NKTs) are strictly CD1d-restricted, and CD1d expression has been found in several types of leukemia and lymphoma as well as in brain tumors suggesting that these malignancies could be targeted for direct NKT-cell cytotoxicity. Several studies have revealed strong positive associations between the numbers of tumor-infiltrating or circulating NKTs with improved disease outcome in patients with diverse types of CD1d-negative solid tumors. The mechanism by ...

Metelitsa, Leonid S.

2011-01-01

205

Robust fractal characterization of 1D and 2D signals

Fractal characterization of signals is well suited in analysis of some time series data and in classification of natural shapes and textures. A maximum likelihood estimator is used to measure the parameter H which is directly related to the fractal dimension. The robustness of the estimator and the performance of the method are demonstrated on datasets generated using a variety of techniques. Finally the characterization is used in segmentation of composite images of natural textures.

Avadhanam, Niranjan; Mitra, Sunanda

1993-10-01

206

KAM tori in 1D random discrete nonlinear Schrodinger model?

Digital Repository Infrastructure Vision for European Research (DRIVER)

We suggest that KAM theory could be extended for certain infinite-dimensional systems with purely discrete linear spectrum. We provide empirical arguments for the existence of square summable infinite-dimensional invariant tori in the random discrete nonlinear Schrodinger equation, appearing with a finite probability for a given initial condition with sufficiently small norm. Numerical support for the existence of a fat Cantor set of initial conditions generating almost periodic oscillations ...

Johansson, Magnus; Kopidakis, G.; Aubry, S.

2010-01-01

207

75 FR 27411 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines

...and 1S1 Turboshaft Engines AGENCY: Federal Aviation...and 1S1 turboshaft engines. That AD requires initial...position checks of the gas generator 2nd stage turbine blades...and 1S1 turboshaft engines that do not...

2010-05-17

208

Directory of Open Access Journals (Sweden)

Full Text Available Na visão computacional, a calibração de câmeras é um processo necessário quando deseja-se recuperar informações como, por exemplo, ângulos e distâncias. O presente trabalho trata do problema de calibração de câmeras com gabaritos de uma única dimensão. Atualmente, tal problema só tem solução se forem impostas restrições ao movimento do gabarito ou se alguns parâmetros das câmeras já sejam previamente conhecidos. Contudo, demonstra-se que uma abordagem diferente pode ser aplicada se, ao invés de uma única câmera, um conjunto binocular for considerado. Nesse caso, a calibração é possível com um gabarito 1D que realiza um deslocamento desconhecido e sem restrições, mesmo sem nenhuma informação prévia a respeito das câmeras. Tal método baseia-se na estimação de uma transformação que, após a estimação da matriz fundamental do sistema, permite atualizar uma calibração projetiva para uma calibração euclidiana. Experimentos em imagens reais e sintéticas validam o novo método e mostram que a sua exatidão é comparável a de outros métodos clássicos de calibração, já bem conhecidos na literatura.In computer vision, the camera calibration is a process needed when the recovery of some information, such as angles and distances, is desired. The present work deals with the problem of camera calibration using one-dimensional patterns. Nowadays, this problem only has a solution if some restrictions to the pattern's movement are imposed or if some angles of the cameras are known in advance. However, a different approach can be applied if, instead of only one camera, a stereo system is considered. In that case, the calibration is possible with a one-dimensional pattern that executes an unknown and unrestricted movement, even without any previous information concerning the cameras. Such method is based on the estimation of a transform which, after the estimation of the system's fundamental matrix, allows updating a projective calibration into a Euclidean calibration. Experiments using both real and synthetic images validate the new method and demonstrate that its accuracy is comparable to other well known calibration methods in the literature.

José Alexandre de França

2011-06-01

209

Twisted N=1, d=4 supergravity and its symmetries

International Nuclear Information System (INIS)

We display the construction of a twisted superalgebra for the N=1 Euclidean supergravity on 4-manifolds with an almost complex structure. It acts on a representation of twisted supersymmetry made of forms with odd and even statistics and it is covariant under a U(2)?SO(4) Lorentz invariance of the manifold's tangent-space. It contains 4 twisted supersymmetry generators, one nilpotent scalar, one vector and one pseudo-scalar. The superalgebra closes on the twisted fields of supergravity in its new minimal set of auxiliary fields. Its couplings to the twisted Wess and Zumino and vector multiplets are also determined.

2013-02-11

210

KAM tori in 1D random discrete nonlinear Schrödinger model?

We suggest that KAM theory could be extended for certain infinite-dimensional systems with purely discrete linear spectrum. We provide empirical arguments for the existence of square summable infinite-dimensional invariant tori in the random discrete nonlinear Schrödinger equation, appearing with a finite probability for a given initial condition with sufficiently small norm. Numerical support for the existence of a fat Cantor set of initial conditions generating almost periodic oscillations is obtained by analyzing i) sets of recurrent trajectories over successively larger time scales, and ii) finite-time Lyapunov exponents. The norm region where such KAM-like tori may exist shrinks to zero when the disorder strength goes to zero and the localization length diverges.

Johansson, M.; Kopidakis, G.; Aubry, S.

2010-09-01

211

Exercise increases TBC1D1 phosphorylation in human skeletal muscle

DEFF Research Database (Denmark)

Exercise and weight loss are cornerstones in the treatment and prevention of type 2 diabetes, and both interventions function to increase insulin sensitivity and glucose uptake into skeletal muscle. Studies in rodents demonstrate that the underlying mechanism for glucose uptake in muscle involves site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 (TBC1D4) and TBC1D1. Multiple kinases, including Akt and AMPK, phosphorylate TBC1D1 and AS160 on distinct residues, regulating their activity and allowing for GLUT4 translocation. In contrast to extensive rodent-based studies, the regulation of AS160 and TBC1D1 in human skeletal muscle is not well understood. In this study, we determined the effects of dietary intervention and a single bout of exercise on TBC1D1 and AS160 site-specific phosphorylation in human skeletal muscle. Ten obese (BMI 33.4 Â± 2.4, M-value 4.3 Â± 0.5) subjects were studied at baseline and after a 2-wk dietary intervention. Muscle biopsies were obtained from the subjects in the resting (basal) state and immediately following a 30-min exercise bout (70% Vo(2 max)). Muscle lysates were analyzed for AMPK activity and Akt phosphorylation and for TBC1D1 and AS160 phosphorylation on known or putative AMPK and Akt sites as follows: AS160 Ser(711) (AMPK), TBC1D1 Ser(231) (AMPK), TBC1D1 Ser(660) (AMPK), TBC1D1 Ser(700) (AMPK), and TBC1D1 Thr(590) (Akt). The diet intervention that consisted of a major shift in the macronutrient composition resulted in a 4.2 Â± 0.4 kg weight loss (P <0.001) and a significant increase in insulin sensitivity (M value 5.6 Â± 0.6), but surprisingly, there was no effect on expression or phosphorylation of any of the muscle-signaling proteins. Exercise increased muscle AMPKÎ±2 activity but did not increase Akt phosphorylation. Exercise increased phosphorylation on AS160 Ser(711), TBC1D1 Ser(231), and TBC1D1 Ser(660) but had no effect on TBC1D1 Ser(700). Exercise did not increase TBC1D1 Thr(590) phosphorylation or TBC1D1/AS160 PAS phosphorylation, consistent with the lack of Akt activation. These data demonstrate that a single bout of exercise regulates TBC1D1 and AS160 phosphorylation on multiple sites in human skeletal muscle.

Jessen, Niels; An, Ding

2011-01-01

212

1D engine simulation of a turbocharged SI engine with CFD computation on components

Digital Repository Infrastructure Vision for European Research (DRIVER)

Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization. This thesis concerns 1D engine simulation of a turbocharged SI engine and the introduction of CFD computations on components as a way to assess inaccuracies in the 1D model. 1D engine ...

2008-01-01

213

Tandem repeats modify the structure of the canine CD1D gene

Digital Repository Infrastructure Vision for European Research (DRIVER)

Among the CD1 proteins that present lipid antigens to T cells, CD1d is the only one that stimulates a population of T cells with an invariant T-cell receptor known as NKT cells. Sequencing of a 722 nucleotide gap in the dog (Canis lupus familiaris) genome revealed that the canine CD1D gene lacks a sequence homologous to exon 2 of human CD1D, coding for the start codon and signal peptide. Also, the canine CD1D gene contains three different short tandem repeats that disrupt the e...

Looringh Beeck, F. A.; Leegwater, P. A. J.; Herrmann, T.; Broere, F.; Rutten, V. P. M. G.; Willemse, T.; Rhijn, I.

2012-01-01

214

A molecular basis for NKT cell recognition of CD1d-self antigen

Digital Repository Infrastructure Vision for European Research (DRIVER)

The antigen receptor for natural killer T cells (NKT TCR) bind CD1d-restricted microbial and self lipid antigens, although the molecular basis of self-CD1d recognition is unclear. Here, we have characterized NKT TCR recognition of CD1d molecules loaded with natural self-antigens (Ags), and report the 2.3 Å resolution structure of an autoreactive NKT TCR-phosphatidylinositol-CD1d complex. NKT TCR recognition of self and foreign antigens was underpinned by a similar mode of germline-encoded re...

Mallevaey, Thierry; Clarke, Andrew J.; Scott-browne, James; Young, Mary H.; Roisman, Laila C.; Pellicci, Daniel G.; Patel, Onisha; Vivian, Julian P.; Matsuda, Jennifer L.; Mccluskey, James; Godfrey, Dale I.; Marrack, Philippa; Rossjohn, Jamie; Gapin, Laurent

2011-01-01

215

Regulation of CD1d expression and function by a herpesvirus infection

Digital Repository Infrastructure Vision for European Research (DRIVER)

Little is known about the role of CD1d-restricted T cells in antiviral immune responses. Here we show that the lytic replication cycle of the Kaposi sarcoma–associated herpesvirus (KSHV) promotes downregulation of cell-surface CD1d. This is caused by expression of the 2 modulator of immune recognition (MIR) proteins of the virus, each of which promotes the loss of surface CD1d expression following transfection into uninfected cells. Inhibition of CD1d surface expression is due to ubiquitina...

Sanchez, David Jesse; Gumperz, Jenny E.; Ganem, Don

2005-01-01

216

The effect of intracellular trafficking of CD1d on the formation of TCR repertoire of NKT cells.

CD1 molecules belong to non-polymorphic MHC class I-like proteins and present lipid antigens to T cells. Five different CD1 genes (CD1a-e) have been identified and classified into two groups. Group 1 include CD1a-c and present pathogenic lipid antigens to ?? T cells reminiscence of peptide antigen presentation by MHC-I molecules. CD1d is the only member of Group 2 and presents foreign and self lipid antigens to a specialized subset of ?? T cells, NKT cells. NKT cells are involved in diverse immune responses through prompt and massive production of cytokines. CD1d-dependent NKT cells are categorized upon the usage of their T cell receptors. A major subtype of NKT cells (type I) is invariant NKT cells which utilize invariant V?14-J?18 TCR alpha chain in mouse. The remaining NKT cells (type II) utilize diverse TCR alpha chains. Engineered CD1d molecules with modified intracellular trafficking produce either type I or type II NKT celldefects suggesting the lipid antigens for each subtypes of NKT cells are processed/generated in different intracellular compartments. Since the usage of TCR by a T cell is the result of antigen-driven selection, the intracellular metabolic pathways of lipid antigen are a key in forming the functional NKT cell repertoire. [BMB Reports 2014; 47(5): 241-248]. PMID:24755556

Shin, Jung Hoon; Park, Se-Ho

2014-05-01

217

Fabrication of GaN/AlGaN 1D photonic crystals designed for nonlinear optical applications

In this paper we present a reliable process to fabricate GaN/AlGaN one dimensional photonic crystal (1D-PhC) microcavities with nonlinear optical properties. We used a heterostructure with a GaN layer embedded between two Distributed Bragg Reflectors consisting of AlGaN/GaN multilayers, on sapphire substrate, designed to generate a {\\lambda}= 800 nm frequency down-converted signal (\\chi^(2) effect) from an incident pump signal at {\\lambda}= 400 nm. The heterostructure was epitaxially grown by metal organic chemical vapour deposition (MOCVD) and integrates a properly designed 1D-PhC grating, which amplifies the signal by exploiting the double effect of cavity resonance and non linear GaN enhancement. The integrated 1D-PhC microcavity was fabricate combing a high resolution e-beam writing with a deep etching technique. For the pattern transfer we used ~ 170 nm layer Cr metal etch mask obtained by means of high quality lift-off technique based on the use of bi-layer resist (PMMA/MMA). At the same time, plasma co...

Stomeo, T; Tasco, V; Tarantini, I; Campa, A; De Vittorio, M; Passaseo, A; Braccini, M; Larciprete, M C; Sibilia, C; Bovino, F A

2011-01-01

218

Simplified 1-D calculation of 13.5-nm emission in a tin plasma including radiation transport

Digital Repository Infrastructure Vision for European Research (DRIVER)

Many next generation lithography schemes for the semiconductor industry are based on a 13.5-nm tin plasma light source, where hundreds of thousands of 4d-4f, 4p-4d, and 4d-5p transitions from Sn5+–Sn13+ ions overlap to form an unresolved transition array. To aid computation, transition arrays are treated statistically, and Hartree-Fock results are used to calculate radiation transport in the optically thick regime with a 1-D Lagrangian plasma hydrodynamics code. Time-dependent spectra and c...

White, John Kingston; Dunne, Padraig; Hayden, Patrick; O Sullivan, Gerry

2009-01-01

219

1D compressible flow with temperature dependent transport coefficients

We establish existence of global-in-time weak solutions to the one dimensional, compressible Navier-Stokes system for a viscous and heat conducting ideal polytropic gas (pressure $p=K\\theta/\\tau$, internal energy $e=c_v \\theta$), when the viscosity $\\mu$ is constant and the heat conductivity $\\kappa$ depends on the temperature $\\theta$ according to $\\kappa(\\theta) = \\bar \\kappa \\theta^\\beta$, with $0\\leq\\beta<{3/2}$. This choice of degenerate transport coefficients is motivated by the kinetic theory of gasses. Approximate solutions are generated by a semi-discrete finite element scheme. We first formulate sufficient conditions that guarantee convergence to a weak solution. The convergence proof relies on weak compactness and convexity, and it applies to the more general constitutive relations $\\mu(\\theta) = \\bar \\mu \\theta^\\alpha$, $\\kappa(\\theta) = \\bar \\kappa \\theta^\\beta$, with $\\alpha\\geq 0$, $0 \\leq \\beta < 2$ ($\\bar \\mu, \\bar \\kappa$ constants). We then verify the sufficient conditions in the case...

Jenssen, Helge Kristian

2009-01-01

220

Development of a 3D consistent 1D neutronics model for reactor core simulation

International Nuclear Information System (INIS)

In this report a 3D consistent 1D model based on nonlinear analytic nodal method is developed to reproduce the 3D results. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. Furthermore in order to properly use 1D group constants, a new 1D group constants representation scheme employing tables for the fuel temperature, moderator density and boron concentration is developed and functionalized for the control rod tip position. To test the 1D kinetics model with CCF, several steady state and transient calculations were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF without significant computational overhead. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. The 1D kinetics model with CCF and the 1D group constant functionalization employing tables as a function of control rod tip position can provide preciser results at the steady state and transient calculation. Thus it is expected that the 1D kinetics model derived in this report can be used in the safety analysis, reactor real time simulation coupled with system analysis code, operator support system etc.

2001-01-01

221

Influence of lipid rafts on CD1d presentation by dendritic cells

DEFF Research Database (Denmark)

Our main objective was to analyze the role of lipid rafts in the activation of Valpha-14(-) and Valpha-14(+) T hybridomas by dendritic cells. We showed that activation of Valpha-14(+) hybridomas by dendritic cells or other CD1d-expressing cells was altered by disruption of lipid rafts with the cholesterol chelator MbetaCD. However, CD1d presentation to autoreactive Valpha-14(-) anti-CD1d hybridomas which do not require the endocytic pathway was not altered. Using partitioning of membrane fractions with Brij98 at 37 degrees C, we confirmed that CD1d was enriched in subcellular fractions corresponding to lipid rafts and we describe that alpha-GalCer enhanced CD1d amount in the low density detergent insoluble fraction. We conclude that the membrane environment of CD1d can influence antigen presentation mainly when the endocytic pathway is required. Flow cytometry analysis can provide additional information on lipid rafts in plasma membranes and allows a dynamics follow-up of lipid rafts partitioning. Using this method, we showed that CD1d plasma membrane expression was sensitive to low concentrations of detergent. This may suggest either that CD1d is associated with lipid rafts mainly in intracellular membranes or that its association with the lipid rafts in the plasma membrane is weak.

Peng, Wei; Martaresche, Cecile

2011-01-01

222

Development of a 3D consistent 1D neutronics model for reactor core simulation

Energy Technology Data Exchange (ETDEWEB)

In this report a 3D consistent 1D model based on nonlinear analytic nodal method is developed to reproduce the 3D results. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. Furthermore in order to properly use 1D group constants, a new 1D group constants representation scheme employing tables for the fuel temperature, moderator density and boron concentration is developed and functionalized for the control rod tip position. To test the 1D kinetics model with CCF, several steady state and transient calculations were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF without significant computational overhead. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. The 1D kinetics model with CCF and the 1D group constant functionalization employing tables as a function of control rod tip position can provide preciser results at the steady state and transient calculation. Thus it is expected that the 1D kinetics model derived in this report can be used in the safety analysis, reactor real time simulation coupled with system analysis code, operator support system etc.

Lee, Ki Bog; Joo, Han Gyu; Cho, Byung Oh; Zee, Sung Quun

2001-02-01

223

Luminescence concentration quenching of 1D2 state in YPO4:Pr3+

International Nuclear Information System (INIS)

Under selective excitation of the 3P0 level of the Pr3+ ion in YPO4, the emission spectra and fluorescence decay curves were measured at different concentrations and temperatures. The origin of the spectral line located at 16 318 cm-1 (612.8 nm) was discussed and attributed to the 1D2 ? 3H4 transition. The process of concentration quenching for the 1D2 state was also studied. Using the Inokuti-Hirayama model, the non-exponential fluorescence decay curves of the 1D2 level were fitted. The result shows that dipole-quadrupole interaction between Pr3+ ions, which causes 1D2 ? 1G4 and 3H4 ? 3F4 cross-relaxation, results in the quenching of 1D2 emissions. (author)

2001-02-05

224

The syntheses and structures of two new Zn(II) complexes, a 2D graphite-like layer {[Zn(PIA)H2 O]?H2 O}n (1) and an independent 1D single-walled metal-organic nanotube (SWMONT) {[Zn2 (PIA)2 (bpy)2 ]?2.5?H2 O?DMA}n (2), have been reported based on a "Y"-shaped 5-(pyridine-4-yl)isophthalic acid ligand (H2 PIA). Interestingly, the 2D graphite-like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2'-bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal-organic nanotube generated from a 2D layer by a "rolling-up" mechanism. PMID:24648263

Zhang, Qingfu; Geng, Aijing; Zhang, Haina; Hu, Falu; Lu, Zhang-Hui; Sun, Dezhi; Wei, Xilian; Ma, Chunlin

2014-04-22

225

Experimental method for laser-driven flyer plates for 1-D shocks

International Nuclear Information System (INIS)

One-dimensional shocks can be generated by impacting flyer plates accelerated to terminal velocities by a confined laser-ablated plasma. Over the past few years, we have developed this capability with our facility-size laser, TRIDENT, capable of ?500 Joules at multi-microsecond pulse lengths to accelerate 1-D flyer plates, 8-mm diameter by 0.1-2 mm thick. Plates have been accelerated to terminal velocities of 100 to ?500 m/s, with full recovery of the flyer and target for post mortem metallography. By properly tailoring the laser temporal and spatial profile, the expanding confined plasma accelerates the plate away from the transparent sapphire substrate, and decouples the laser parameters from shock pressure profile resulting from the plate impact on a target. Since the flyer plate is in free flight on impact with the target, minimal collateral damage occurs to either. The experimental method to launch these plates to terminal velocity, ancillary diagnostics, and representative experimental data is presented

2007-12-12

226

Surface roughened 1-D Au host nanorods for visible light induced photocatalyst

International Nuclear Information System (INIS)

Highlights: • Surface roughened 1-D Au host nanorods for visible light induced photocatalyst are tried. • A nanofilm of hematite coated on high conducting and vertically aligned smooth Au nanorods or nanoporous Au nanorods is prepared. • We report an effect of surface morphology of Au nanorods on the photoactivity of hematite/gold nanorod arrays prepared by the electrodeposition method. -- Abstract: Visible light induced photocatalytic degradation of rhodamine B and hydrogen generation from solar water splitting by hematite (?-Fe2O3) coated gold (Au) nanorods have been investigated, in which two types of ?-Fe2O3/Au nanorods with different Au surfaces were synthesized and then carefully compared. Vertically aligned smooth Au nanorod and porous Au nanorod arrays were prepared by the electro-deposition method using anodized aluminum oxide templates, followed by deposition of hematite onto nanoporous Au nanorods and smooth Au nanorods to synthesize core/shell like nanostructure. The as-prepared samples were characterized by Field Emission Scanning Electron Microscopy, X-ray Diffraction, and X-ray Photoelectron Spectroscopy. Also, their photocatalytic activities were investigated by photo-degradation of rhodamine B, photocurrent–voltage, and incident photon to current conversion efficiency measurements under AM 1.5G light irradiation. Hematite (?-Fe2O3) coated porous Au nanorods showed better photocatalytic activities than ?-Fe2O3 coated smooth Au nanorods, showing faster dye degradation rate, higher photocurrent density and better photon harvesting

2013-05-01

227

Structure and Catalytic Mechanism of Human Steroid 5-Reductase (AKR1D1)

Energy Technology Data Exchange (ETDEWEB)

Human steroid 5{beta}-reductase (aldo-keto reductase (AKR) 1D1) catalyzes reduction of {Delta}{sup 4}-ene double bonds in steroid hormones and bile acid precursors. We have reported the structures of an AKR1D1-NADP{sup +} binary complex, and AKR1D1-NADP{sup +}-cortisone, AKR1D1-NADP{sup +}-progesterone and AKR1D1-NADP{sup +}-testosterone ternary complexes at high resolutions. Recently, structures of AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone complexes showed that the product is bound unproductively. Two quite different mechanisms of steroid double bond reduction have since been proposed. However, site-directed mutagenesis supports only one mechanism. In this mechanism, the 4-pro-R hydride is transferred from the re-face of the nicotinamide ring to C5 of the steroid substrate. E120, a unique substitution in the AKR catalytic tetrad, permits a deeper penetration of the steroid substrate into the active site to promote optimal reactant positioning. It participates with Y58 to create a 'superacidic' oxyanion hole for polarization of the C3 ketone. A role for K87 in the proton relay proposed using the AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone structure is not supported.

Costanzo, L.; Drury, J; Christianson, D; Penning, T

2009-01-01

228

Apolipoprotein A-IV reduces hepatic gluconeogenesis through nuclear receptor NR1D1.

We showed recently that apoA-IV improves glucose homeostasis by enhancing pancreatic insulin secretion in the presence of elevated levels of glucose. Therefore, examined whether apolipoprotein A-IV (apoA-IV) also regulates glucose metabolism through the suppression of hepatic gluconeogenesis. The ability of apoA-IV to lower gluconeogenic gene expression and glucose production was measured in apoA-IV(-/-) and wild-type mice and primary mouse hepatocytes. The transcriptional regulation of Glc-6-Pase and phosphoenolpyruvate carboxykinase (PEPCK) by apoA-IV was determined by luciferase activity assay. Using bacterial two-hybrid library screening, NR1D1 was identified as a putative apoA-IV-binding protein. The colocalization and interaction between apoA-IV and NR1D1 were confirmed by immunofluorescence, in situ proximity ligation assay, and coimmunoprecipitation. Enhanced recruitment of NR1D1 and activity by apoA-IV to Glc-6-Pase promoter was verified with ChIP and a luciferase assay. Down-regulation of apoA-IV on gluconeogenic genes is mediated through NR1D1, as illustrated in cells with NR1D1 knockdown by siRNA. We found that apoA-IV suppresses the expression of PEPCK and Glc-6-Pase in hepatocytes; decreases hepatic glucose production; binds and activates nuclear receptor NR1D1 and stimulates NR1D1 expression; in cells lacking NR1D1, fails to inhibit PEPCK and Glc-6-Pase gene expression; and stimulates higher hepatic glucose production and higher gluconeogenic gene expression in apoA-IV(-/-) mice. We conclude that apoA-IV inhibits hepatic gluconeogenesis by decreasing Glc-6-Pase and PEPCK gene expression through NR1D1. This novel regulatory pathway connects an influx of energy as fat from the gut (and subsequent apoA-IV secretion) with inhibition of hepatic glucose production. PMID:24311788

Li, Xiaoming; Xu, Min; Wang, Fei; Kohan, Alison B; Haas, Michael K; Yang, Qing; Lou, Danwen; Obici, Silvana; Davidson, W Sean; Tso, Patrick

2014-01-24

229

Energy Technology Data Exchange (ETDEWEB)

Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Su, Xiong [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Liu, Jialiu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Sundaresan, Sinju [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Stahl, Philip D., E-mail: pstahl@wustl.edu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)

2013-05-03

230

Expression of CD1d and presence of invariant NKT cells in classical Hodgkin lymphoma

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract We studied CD1d-restricted invariant natural killer T (iNKT) cells in classical Hodgkin lymphoma (cHL). Tumor cells stained positive for CD1d in 21/44 cHL cases, whereas in non-Hodgkin lymphoma (NHL) only 9/31 stained positive. In contrast, CD1c expression was more common in NHL. The percentage of iNKT cells in cHL cell suspensions was similar to the percentage in reactive lymph nodes and was not related to the CD1d expression status of the tumor cells. In conclusion, we f...

2010-01-01

231

Proteasome-mediated degradation antagonizes critical levels of the apoptosis-inducing C1D protein

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract The C1D gene is expressed in a broad spectrum of mammalian cells and tissues but its product induces apoptotic cell death when exceeding a critical level. Critical levels are achieved in a fraction of cells by transient transfection with EGFP-tagged C1D expression constructs. However, transfected cells expressing sub-critical levels of C1D(EGFP) escape apoptotic cell death by activation of a proteasome-mediated rescue mechanism. Inhibition of the proteasome-dependent degrad...

Rothbarth Karsten; Stammer Hermann; Werner Dieter

2002-01-01

232

Pfaffian-like ground state for 3-body-hard-core bosons in 1D lattices

We propose a Pfaffian-like Ansatz for the ground state of bosons subject to 3-body infinite repulsive interactions in a 1D lattice. Our Ansatz consists of the symmetrization over all possible ways of distributing the particles in two identical Tonks-Girardeau gases. We support the quality of our Ansatz with numerical calculations and propose an experimental scheme based on mixtures of bosonic atoms and molecules in 1D optical lattices in which this Pfaffian-like state could be realized. Our findings may open the way for the creation of non-abelian anyons in 1D systems.

Paredes, B; Cirac, J I

2006-01-01

233

A rectangular fin optimization including comparison between 1-D and 2-D analyses

Energy Technology Data Exchange (ETDEWEB)

Both 1-D and 2-D analytic methods are used for a rectangular fin optimization. Optimum heat loss is taken as 98% of the maximum heat loss. Temperature profile using 2-D analytic method and relative error of temperature along the fin length between 1-D and 2-D analytic methods are presented. Increasing rate of the optimum heat loss with the variation of Biot number and decreasing rate of that with the variation of the fin base length are listed. Optimum fin tip length using 2-D analytic method and relative error of that between 1-D and 2-D analytic methods are presented as a function of Biot numbers ratio.

Kang, Hyung Suk [Kangwon National University, Chunchon (Korea, Republic of)

2006-12-15

234

Mycobacterial phosphatidylinositol mannoside is a natural antigen for CD1d-restricted T cells

Digital Repository Infrastructure Vision for European Research (DRIVER)

A group of T cells recognizes glycolipids presented by molecules of the CD1 family. The CD1d-restricted natural killer T cells (NKT cells) are primarily considered to be self-reactive. By employing CD1d-binding and T cell assays, the following structural parameters for presentation by CD1d were defined for a number of mycobacterial and mammalian lipids: two acyl chains facilitated binding, and a polar head group was essential for T cell recognition. Of the mycobacterial lipids tested, only a ...

Fischer, Karsten; Scotet, Emmanuel; Niemeyer, Marcus; Koebernick, Heidrun; Zerrahn, Jens; Maillet, Sophie; Hurwitz, Robert; Kursar, Mischo; Bonneville, Marc; Kaufmann, Stefan H. E.; Schaible, Ulrich E.

2004-01-01

235

International Nuclear Information System (INIS)

A new simplified technique for 1D non-uniform dose delivery using a single dynamic absorber, driven by a computer system, has been recently proposed together with a simple analytic algorithm. This technique uses an 0ptimized 'stepped' absorber's speed profile and the generated fluence profile is an approximation of the desired radiation beam. In the case of non-uniform beam profiles with multiple maxima/minima, the original proposed stepping algorithm' has some limitations and produces a too rough approximation of the desired profiles. In order to increase the agreement between desired and generated profiles, more sophisticated optimization schemes are required. In this paper we have applied a variant of simulated annealing (SA) as a statistical optimization algorithm to further investigate the possibilities and the limits of the single-absorber technique in the field of 1D intensity modulation. In the current application the cost function used is the mean square root of the percentage differences between desired and generated profiles, the absorber's resting times have been chosen as optimization variables and at each iteration just one variable is randomly changed, adding an incremental 'grain'. A Cauchy generating function is used, different cooling schedules are evaluated; constraints related to our apparatus are introduced and starting annealing parameters are set after some initial optimization tests. The method is tested in reproducing theoretical non-uniform beams, by comparing desired modulated fluence profiles with calculated fluence profiles obtainable with the single absorber after the derivation of optimized speed profiles by the proposed SA approach. The results of these simulations show that the application of the SA method optimizes the single absorber's performance and that clinically important modulated beams useful for conformal radiotherapy can be accurately reproduced. (author)

1997-01-01

236

A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of 1-?-d-Arabinofuranosylcytosine (ara-C), 1-?-d-Arabinofuranosyluracil (ara-U) and 1-?-d-Arabinofuranosylcytosine triphosphate (ara-CTP) in the leukemic cells for the first time. The analytes were separated on a C18 column (100mm×2.1mm, 1.8?m) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The ion-pairing reagent, NFPA, was added to the mobile phase to retain the analytes in the column. The cell homogenates sample was prepared by the simple protein precipitation. The calibration curves were linear over a concentration range of 3.45-3450.0ng/mL for ara-C, 1.12-1120.0ng/mL for ara-U and 4.13-4130.0ng/mL for ara-CTP. The intra-day and inter-day precision was less than 15% and the relative error (RE) were all within ±15%. The validated method was successfully applied to assess the disposition characteristics of ara-C and support cell pharmacokinetics after the patients with leukemia were intravenously infused with SDAC and HiDAC. The result of the present study would provide the valuable information for the ara-C therapy. PMID:24880220

Liang, Di; Wang, Wei; Jiang, Xuechun; Yin, Shiliang

2014-07-01

237

Recent ARPES experiments on quasi-1D bulk materials and artificial structures.

The spectroscopy of quasi-one-dimensional (1D) systems has been a subject of strong interest since the first experimental observations of unusual line shapes in the early 1990s. Angle-resolved photoemission (ARPES) measurements performed with increasing accuracy have greatly broadened our knowledge of the properties of bulk 1D materials and, more recently, of artificial 1D structures. They have yielded a direct view of 1D bands, of open Fermi surfaces, and of characteristic instabilities. They have also provided unique microscopic evidence for the non-conventional, non-Fermi-liquid, behavior predicted by theory, and for strong and singular interactions. Here we briefly review some of the remarkable experimental results obtained in the last decade. PMID:21813968

Grioni, M; Pons, S; Frantzeskakis, E

2009-01-14

238

Novel calibration method for non-overlapping multiple vision sensors based on 1D target

The global calibration of multiple vision sensors (MVS) with non-overlapping views has been widely studied. In this paper, a novel calibration method for MVS with non-overlapping fields of view based on 1D target is presented. First, two neighboring vision sensors are selected. The rotation matrix between the two vision sensors is computed using the co-linearity property of the feature points on 1D target. Then the translation vector is computed according to the known distances between feature points on 1D target. The global calibration of all vision sensors is realized by repeating the above pair-wise calibration on different pairs of vision sensors. Due to the small volume and mobility of 1D target, the proposed global calibration method can be applied to vision sensors distributed in a large area or narrow space. Experiment results show that the RMS error of global calibration is within 0.060 mm.

Liu, Zhen; Zhang, Guangjun; Wei, Zhenzhong; Sun, Junhua

2011-04-01

239

On dispersion for Klein Gordon equation with periodic potential in 1D

Digital Repository Infrastructure Vision for European Research (DRIVER)

By exploiting estimates on Bloch functions obtained in a previous paper, we prove decay estimates for Klein Gordon equations with a time independent potential periodic in space in 1D and with generic mass

Cuccagna, Scipio

2007-01-01

240

2D separated-local-field spectra from projections of 1D experiments

A novel procedure for reconstruction of 2D separated-local-field (SLF) NMR spectra from projections of 1D NMR data is presented. The technique, dubbed SLF projection reconstruction from one-dimensional spectra (SLF-PRODI), is particularly useful for uniaxially oriented membrane protein samples and represents a fast and robust alternative to the popular PISEMA experiment which correlates 1H- 15N dipole-dipole couplings with 15N chemical shifts. The different 1D projections in the SLF-PRODI experiment are obtained from 1D spectra recorded under influence of homonuclear decoupling sequences with different scaling factors for the heteronuclear dipolar couplings. We demonstrate experimentally and numerically that as few as 2-4 1D projections will normally be sufficient to reconstruct a 2D SLF-PRODI spectrum with a quality resembling typical PISEMA spectra, leading to significant reduction of the acquisition time.

Bertelsen, Kresten; Pedersen, Jan M.; Nielsen, Niels Chr.; Vosegaard, Thomas

2007-02-01

241

Differential constraints for Kaup -- Broer system as reduction of 1-D Toda lattice

It is shown that some special reduction of infinite 1-D Toda lattice gives differential constraints compatible with Kaup -- Broer system. A family of the travelling wave solutions of Kaup -- Broer system and its higher version is constructed.

Svinin, A K

2001-01-01

242

Comment on supersymmetrization of N = 1 D = 10 supergravity with Lorentz Chern-Simons term

International Nuclear Information System (INIS)

We re-examine supersymmetrization of the N = 1 D = 10 supergravity with Lorentz Chern-Simons term. The supersymmetric counterparts are determined to the first order of some Noether expansion parameter, and they have one arbitrary parameter. (author)

1986-01-01

243

Decreased sensitivity of 5-HT1D receptors in chronic tension-type headache

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVE: To assess the sensitivity of 5-HT1D receptors in chronic tension-type headache using sumatriptan as a pharmacological probe. BACKGROUND: Previous studies have suggested involvement of serotonergic systems in chronic tension-type headache (CTTH), but relevant experimental data are limited. Sumatriptan, a 5-HT1B/1D receptor agonist, stimulates the release of growth hormone (GH) and inhibits the release of ACTH, cortisol, and prolactin. These effects may be used to explore the functio...

2002-01-01

244

Abnormal 5-HT1D receptor function in cluster headache: A neuroendocrine study with sumatriptan

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this study was to assess the sensitivity of 5-HT(1D) receptors in patients with episodic cluster headache using sumatriptan as a pharmacological probe. The drug, a selective 5-HT(1B/1D) agonist, stimulates the secretion of growth hormone and inhibits the release of prolactin, adrenocorticotropic hormone (ACTH) and cortisol. These effects may be used to explore the function of serotonergic systems in vivo. We administered subcutaneous sumatriptan and placebo to 20 patients with ...

2003-01-01

245

O(1D) Production Following Electron Impact on Oxygen-Containing Molecules

International Nuclear Information System (INIS)

A solid Ne matrix detector is used to study electron-impact dissociation pathways in CO2 and N2O. This matrix is selectively sensitive to the metastable oxygen species, O(1D). O(1D) is an important constituent in the atmospheres of Earth and other extra-terrestrial objects. Kinetic energy and excitation function data for production of this species will be presented.

2012-11-05

246

1-D Air-snowpack modeling of atmospheric nitrous acid at South Pole during ANTCI 2003

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 1-D air-snowpack model of HONO has been developed and constrained by observed chemistry and meteorology data. The 1-D model includes molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate and interstitial air HONO photolysis. Photolysis of nitrate is important as a dominant HONO source inside the snowpack, however, the observed HONO emission from the snowpack was triggered mainly by the equilibri...

Wei Liao; Tan, D.

2008-01-01

247

A perfectly matched layer based technique for the scattering from 1-D periodic microstrip structures

Digital Repository Infrastructure Vision for European Research (DRIVER)

An efficient technique is presented to compute the scattering from one-dimensional (1-D) periodic microstrip structures, illuminated by a plane wave under perpendicular incidence. The technique relies on a Mixed Potential Integral Equation (MPIE), discretized by the Method of Moments (MoM), solving for the unknown current density flowing within a unit cell of the periodic structure. The pertinent 1-D periodic Green's functions are obtained by invoking the Perfectly Matched Layer (PML)-paradig...

Vande Ginste, Dries; Rogier, Hendrik

2010-01-01

248

Efficient Fast Multiplication Free Integer Transformation for the 1-D DCT of the H.265 Standard

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, efficient one-dimensional (1-D) fast integer transform algorithms of the DCT matrix for the H.265 stan-dard is proposed. Based on the symmetric property of the integer transform matrix and the matrix operations, which denote the row/column permutations and the matrix decompositions, along with using the dyadic symmetry modification on the standard matrix, the efficient fast 1-D integer transform algorithms are developed. Therefore, the computational complexities of the proposed...

Mohamed Nasr Haggag; Mohamed El-Sharkawy; Gamal Fahmy; Maher Rizkalla

2010-01-01

249

Quantum Cable as transport spectroscopy of 1D DOS of cylindrical quantum wires

We considered the proposed Quantum Cable as a kind of transport spectroscopy of one-dimensional (1D) density of states (DOS) of cylindrical quantum wires. By simultaneously detecting the direct current through the cylindrical quantum wire and the leaked tunneling current into the neighboring wire at desired temperatures, one can obtain detailed information about 1D DOS and subband structure of cylindrical quantum wires.

Zeng, Z Y; Zhang, L D

2000-01-01

250

"Exact WKB integration'' of polynomial 1D Schr\\"odinger (or Sturm-Liouville) problem

We review an "exact semiclassical" resolution method for the general stationary 1D Schr\\"odinger equation with a polynomial potential. This method avoids having to compute any Stokes phenomena directly; instead, it basically relies on an elementary Wronskian identity, and on a fully exact form of Bohr--Sommerfeld quantization conditions which can also be viewed as a Bethe-Ansatz system of equations that will "solve" the general polynomial 1D Schr\\"odinger problem.

Voros, A

2002-01-01

251

Protective mucosal immunity mediated by epithelial CD1d and IL-10.

The mechanisms by which mucosal homeostasis is maintained are of central importance to inflammatory bowel disease. Critical to these processes is the intestinal epithelial cell (IEC), which regulates immune responses at the interface between the commensal microbiota and the host. CD1d presents self and microbial lipid antigens to natural killer T (NKT) cells, which are involved in the pathogenesis of colitis in animal models and human inflammatory bowel disease. As CD1d crosslinking on model IECs results in the production of the important regulatory cytokine interleukin (IL)-10 (ref. 9), decreased epithelial CD1d expression--as observed in inflammatory bowel disease--may contribute substantially to intestinal inflammation. Here we show in mice that whereas bone-marrow-derived CD1d signals contribute to NKT-cell-mediated intestinal inflammation, engagement of epithelial CD1d elicits protective effects through the activation of STAT3 and STAT3-dependent transcription of IL-10, heat shock protein 110 (HSP110; also known as HSP105), and CD1d itself. All of these epithelial elements are critically involved in controlling CD1d-mediated intestinal inflammation. This is demonstrated by severe NKT-cell-mediated colitis upon IEC-specific deletion of IL-10, CD1d, and its critical regulator microsomal triglyceride transfer protein (MTP), as well as deletion of HSP110 in the radioresistant compartment. Our studies thus uncover a novel pathway of IEC-dependent regulation of mucosal homeostasis and highlight a critical role of IL-10 in the intestinal epithelium, with broad implications for diseases such as inflammatory bowel disease. PMID:24717441

Olszak, Torsten; Neves, Joana F; Dowds, C Marie; Baker, Kristi; Glickman, Jonathan; Davidson, Nicholas O; Lin, Chyuan-Sheng; Jobin, Christian; Brand, Stephan; Sotlar, Karl; Wada, Koichiro; Katayama, Kazufumi; Nakajima, Atsushi; Mizuguchi, Hiroyuki; Kawasaki, Kunito; Nagata, Kazuhiro; Müller, Werner; Snapper, Scott B; Schreiber, Stefan; Kaser, Arthur; Zeissig, Sebastian; Blumberg, Richard S

2014-05-22

252

The D1-D2 heterodimer in the reaction center core of phototrophs binds the redox plastoquinone cofactors, Q(A) and Q(B), the terminal acceptors of the photosynthetic electron transfer chain in the photosystem II (PSII). This complex is the target of the herbicide atrazine, an environmental pollutant competitive inhibitor of Q(B) binding, and consequently it represents an excellent biomediator to develop biosensors for pollutant monitoring in ecosystems. In this context, we have undertaken a study of the Chlamydomonas reinhardtii D1-D2 proteins aimed at designing site directed mutants with increased affinity for atrazine. The three-dimensional structure of the D1 and D2 proteins from C. reinhardtii has been homology modeled using the crystal structure of the highly homologous Thermosynechococcus elongatus proteins as templates. Mutants of D1 and D2 were then generated in silico and the atrazine binding affinity of the mutant proteins has been calculated to predict mutations able to increase PSII affinity for atrazine. The computational approach has been validated through comparison with available experimental data and production and characterization of one of the predicted mutants. The latter analyses indicated an increase of one order of magnitude of the mutant sensitivity and affinity for atrazine as compared to the control strain. Finally, D1-D2 heterodimer mutants were designed and selected which, according to our model, increase atrazine binding affinity by up to 20 kcal/mol, representing useful starting points for the development of high affinity biosensors for atrazine. PMID:19693932

Rea, Giuseppina; Polticelli, Fabio; Antonacci, Amina; Scognamiglio, Viviana; Katiyar, Prashant; Kulkarni, Sudhir A; Johanningmeier, Udo; Giardi, Maria Teresa

2009-10-01

253

Exome sequencing identifies somatic gain-of-function PPM1D mutations in brainstem gliomas.

Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect. To determine the genetic and epigenetic landscape of these tumors, we performed exomic sequencing of 14 brainstem gliomas (BSGs) and 12 thalamic gliomas. We also performed targeted mutational analysis of an additional 24 such tumors and genome-wide methylation profiling of 45 gliomas. This study led to the discovery of tumor-specific mutations in PPM1D, encoding wild-type p53-induced protein phosphatase 1D (WIP1), in 37.5% of the BSGs that harbored hallmark H3F3A mutations encoding p.Lys27Met substitutions. PPM1D mutations were mutually exclusive with TP53 mutations in BSG and attenuated p53 activation in vitro. PPM1D mutations were truncating alterations in exon 6 that enhanced the ability of PPM1D to suppress the activation of the DNA damage response checkpoint protein CHK2. These results define PPM1D as a frequent target of somatic mutation and as a potential therapeutic target in brainstem gliomas. PMID:24880341

Zhang, Liwei; Chen, Lee H; Wan, Hong; Yang, Rui; Wang, Zhaohui; Feng, Jie; Yang, Shaohua; Jones, Siân; Wang, Sizhen; Zhou, Weixin; Zhu, Huishan; Killela, Patrick J; Zhang, Junting; Wu, Zhen; Li, Guilin; Hao, Shuyu; Wang, Yu; Webb, Joseph B; Friedman, Henry S; Friedman, Allan H; McLendon, Roger E; He, Yiping; Reitman, Zachary J; Bigner, Darell D; Yan, Hai

2014-07-01

254

Digital Repository Infrastructure Vision for European Research (DRIVER)

Final HERMES results on the proton, deuteron and neutron structure function g1 are presented in the kinematic range 0.0021

Riedl, Caroline; Hermes-collaboration, For The

2004-01-01

255

Final HERMES results on the proton, deuteron and neutron structure function g1 are presented in the kinematic range 0.0021

Riedl, C; Akopov, Z; Amarian, M; Ammosov, V V; Andrus, A; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetisian, A; Avetissian, E; Bailey, P; Baturin, V; Baumgarten, C; Beckmann, M; Belostotskii, S; Bernreuther, S; Bianchi, N; Blok, H P; Böttcher, Helmut B; Borisov, A; Bouwhuis, M; Brack, J; Brüll, A; Bryzgalov, V V; Capitani, G P; Chiang, H C; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; Devitsin, E G; Di Nezza, P; Düren, M; Ehrenfried, M; Elalaoui-Moulay, A; Elbakian, G M; Ellinghaus, F; Elschenbroich, U; Ely, J; Fabbri, R; Fantoni, A; Feshchenko, A; Felawka, L; Fox, B; Franz, J; Frullani, S; Gärber, Y; Gapienko, G; Gapienko, V; Garibaldi, F; Garrow, K; Garutti, E; Gaskell, D; Gavrilov, G E; Karibian, V; Graw, G; Grebenyuk, O; Greeniaus, L G; Hafidi, K; Hartig, M; Hasch, D; Heesbeen, D; Henoch, M; Hertenberger, R; Hesselink, W H A; Hillenbrand, A; Hoek, M; Holler, Y; Hommez, B; Iarygin, G; Ivanilov, A; Izotov, A; Jackson, H E; Jgoun, A; Kaiser, R; Kinney, E; Kiselev, A; Königsmann, K C; Kopytin, M; Korotkov, V A; Kozlov, V; Krauss, B; Krivokhizhin, V G; Lagamba, L; Lapikas, L; Laziev, A; Lenisa, P; Liebing, P; Lindemann, T; Lipka, K; Lorenzon, W; Lü, J; Maiheu, B; Makins, N C R; Marianski, B; Marukyan, H O; Masoli, F; Mexner, V; Meyners, N; Miklukho, O; Miller, C A; Miyachi, Y; Muccifora, V; Nagaitsev, A; Nappi, E; Naryshkin, Yu; Nass, A; Negodaev, M A; Nowak, Wolf-Dieter; Oganessyan, K; Ohsuga, H; Orlandi, G; Pickert, N; Potashov, S Yu; Potterveld, D H; Raithel, M; Reggiani, D; Reimer, P E; Reischl, A; Reolon, A R; Rith, K; Airapetian, A; Rosner, G; Rostomyan, A; Rubacek, L; Ryckbosch, D; Salomatin, Yu I; Sanjiev, I; Savin, I; Scarlett, C; Schäfer, A; Schill, C; Schnell, G; Schüler, K P; Schwind, A; Seele, J; Seidl, R; Seitz, B; Shanidze, R G; Shearer, C; Shibata, T A; Shutov, V B; Simani, M C; Sinram, K; Stancari, M D; Statera, M; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Tait, P; Tanaka, H; Taroian, S P; Tchuiko, B; Terkulov, A R; Tkabladze, A V; Trzcinski, A; Tytgat, M; Vandenbroucke, A; Van der Nat, P B; van der Steenhoven, G; Vetterli, Martin C; Vikhrov, V; Vincter, M G; Visser, J; Vogel, C; Vogt, M; Volmer, J; Weiskopf, C; Wendland, J; Wilbert, J; Ybeles-Smit, G V; Yen, S; Zihlmann, B; Zohrabyan, H G; Zupranski, P; Riedl, Caroline

2005-01-01

256

Global analytical ab initio ground-state potential energy surface for the C(1D)+H2 reactive system

A new global ab initio potential energy surface (called ZMB-a) for the 1^1A^' } state of the C(1D)+H2 reactive system has been constructed. This is based upon ab initio calculations using the internally contracted multireference configuration interaction approach with the aug-cc-pVQZ basis set, performed at about 6300 symmetry unique geometries. Accurate analytical fits are generated using many-body expansions with the permutationally invariant polynomials, except that the fit of the deep well region is taken from our previous fit. The ZMB-a surface is unique in the accurate description of the regions around conical intersections (CIs) and of van der Waals (vdW) interactions. The CIs between the 1^1A^' } and 2^1A^' } states cause two kinds of barriers on the ZMB-a surface: one is in the linear H-CH dissociation direction with a barrier height of 9.07 kcal/mol, which is much higher than those on the surfaces reported before; the other is in the C(1D) collinearly attacking H2 direction with a barrier height of 12.39 kcal/mol. The ZMB-a surface basically reproduces our ab initio calculations in the vdW interaction regions, and supports a linear C-HH vdW complex in the entrance channel, and two vdW complexes in the exit channel, at linear CH-H and HC-H geometries, respectively.

Zhang, Chunfang; Fu, Mingkai; Shen, Zhitao; Ma, Haitao; Bian, Wensheng

2014-06-01

257

One-dimensional (1D) zinc oxide nanostructures are the main components of nanogenerators and central to the emerging field of nanopiezotronics. Understanding the underlying physics and quantifying the electromechanical properties of these structures, the topic of this research study, play a major role in designing next-generation nanoelectromechanical devices. Here, atomistic simulations are utilized to study surface and size-scale effects on the electromechanical response of 1D ZnO nanostructures. It is shown that the mechanical and piezoelectric properties of these structures are controlled by their size, cross-sectional geometry, and loading configuration. The study reveals enhancement of the piezoelectric and elastic modulus of ZnO nanowires (NW) with diameter d > 1 nm, followed by a sudden drop for d piezoelectric properties of ZnO nanobelts (NBs) followed by an enhancement in piezoelectric properties occurs when their lower dimension is reduced to piezoelectric wurtzite to nonpiezoelectric body-centered tetragonal (WZ ? BCT) and graphite-like phase (WZ ? HX) structures occurs in ZnO NWs loaded up to large strains of ?10%. PMID:24296508

Momeni, Kasra; Attariani, Hamed

2014-03-14

258

Benchmarks and models for 1-D radiation transport in stochastic participating media

Energy Technology Data Exchange (ETDEWEB)

Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material temperature. Benchmark values and variances for time evolution of the ensemble average of material temperature energy density and radiation transmission are computed via a Monte Carlo type method. These benchmarks are used as a basis for comparison with three other approximate methods of solution. One of these approximate methods is simple atomic mix. The second approximate model is an adaptation of what is commonly called the Levermore-Pomraning model and which is referred to here as the standard model. It is shown that recasting the temperature coupling as a type of effective scattering can be useful in formulating the third approximate model, an adaptation of a model due to Su and Pomraning which attempts to account for the effects of scattering in a stochastic context. This last adaptation shows consistent improvement over both the atomic mix and standard models when used in the 1-D slab geometry but shows limited improvement in the 1-D spherical geometry. Benchmark values are also computed for radiation transmission from the 1-D sphere without material heating present. This is to evaluate the performance of the standard model on this geometry--something which has never been done before. All of the various tests demonstrate the importance of stochastic structure on the solution. Also demonstrated are the range of usefulness and limitations of a simple atomic mix formulation.

Miller, D S

2000-08-21

259

We present a new abundance analysis of HE 1327-2326, the currently most iron-poor star, based on observational data obtained with VLT/UVES. We correct the 1D LTE abundances for 3D effects to provide an abundance pattern that supersedes previous works, and should be used to observationally test current models of the chemical yields of the first-generation SNe. Apart from confirming the 1D LTE abundances found in previous studies before accounting for 3D effects, we make use of a novel technique to apply the 3D-1D corrections for CNO which are a function of excitation potential and line strength for the molecular lines that comprise the observable CH, NH, and OH features. We find that the fit to the NH band at 3360 A is greatly improved due to the application of the 3D-1D corrections. This may indicate that 3D effects are actually observable in this star. We also report the first detection of several weak Ni lines. The cosmologically important element Li is still not detected; the new Li upper limit is extremel...

Frebel, Anna; Collet, Remo; Christlieb, Norbert; Aoki, Wako

2008-01-01

260

Stress Distribution in the Direction of 1-D Motion of an Interstitial Loop

Energy Technology Data Exchange (ETDEWEB)

We studied a stress distribution around a dislocation loop to know the effect of compressive stress on 1-D motion of defect clusters. And we presented the effect of 1-D motion on the radiation hardening. Two mechanisms of radiation hardening have been proposed. One is a dispersed barrier hardening mechanism. This explains defect clusters as barriers to a dislocation motion. And the other is a cascade induced source hardening mechanism, which places emphasis on the role of defects as a Cottrell atmosphere for dislocation motions. The interaction between dislocation and defect clusters has been considered, but the self-motion of clusters was not considered. No model has given a solution to the 1-D motion of defect clusters of a size of over 2 nm. Though the 1-D motion of defect clusters was observed by many researchers, they did not consider its effect on radiation hardening. To establish the effect of a 1-D motion on radiation damage, it is important to clarify the driving force of this motion. At this time, we tried to find out stress field into the motion direction of clusters through calculations with equations suggested by T. A. Kraishi et al.

Kwon, Sang Chul; Kim, Whung Whoe [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Moon, Won Jin; Kim, Young Min [Korea Basic Science Institute, Daejeon (Korea, Republic of)

2007-07-01

261

Lifetime measurements of the 3d94s(1D)4p configuration of Cu. Pt. 1

International Nuclear Information System (INIS)

The radiative lifetimes of the levels in the 3d94s(1D)4p configuration of Cu I are measured. The levels are excited from the metastable 3d94s2 2D3/2,5/2 levels. The metastable Cu atoms are generated in a pulsed hollow cathode discharge. The levels investigated are populated with a 35-ps laser pulse at wavelengths around 220 nm. The laser induced fluorescence signal is detected. The lifetime of the 3d94s(3D)4p 4D1/2 level is also determined by direct excitation from the ground state. A comparison with calculated literature values is given. (orig.)

1993-02-01

262

Hidden nonlinear su(2|2) superunitary symmetry of N=2 superextended 1D Dirac delta potential problem

International Nuclear Information System (INIS)

We show that the N=2 superextended 1D quantum Dirac delta potential problem is characterized by the hidden nonlinear su(2|2) superunitary symmetry. The unexpected feature of this simple supersymmetric system is that it admits three different Z2-gradings, which produce a separation of 16 integrals of motion into three different sets of 8 bosonic and 8 fermionic operators. These three different graded sets of integrals generate two different nonlinear, deformed forms of su(2|2), in which the Hamiltonian plays a role of a multiplicative central charge. On the ground state, the nonlinear superalgebra is reduced to the two distinct 2D Euclidean analogs of a superextended Poincare algebra used earlier in the literature for investigation of spontaneous supersymmetry breaking. We indicate that the observed exotic supersymmetric structure with three different Z2-gradings can be useful for the search of hidden symmetries in some other quantum systems, in particular, related to the Lame equation

2008-01-24

263

Analysis of Phase Space Structure of A 1-D Discrete System Using Global and Local Symbolic Dynamics

International Nuclear Information System (INIS)

Symbolic dynamics, in which the system trajectory is represented as a string of symbols, appears as a convenient method for the analysis of properties of chaotic attractors. In this paper, we show that, using a noncanonical coding scheme based on a moving partition point, we are able to access such properties of the phase space of a dynamical system as the localisation of unstable periodic orbits and of their stable invariant manifolds. Applying different coding schemes enables us to extract different information about the phase space structure from the chaotic trajectory. A judicial choice of the method of symbolic coding allows to obtain information which may be missing in the symbolic dynamics from the generating partition. We present results for the 1-D case taking the logistic map as a numerical example. The extension to higher dimension is also discussed. The theoretical background of the methods used is also given. (author)

2005-05-01

264

TBC1D24 Mutation Causes Autosomal-Dominant Nonsyndromic Hearing Loss.

Hereditary hearing loss is extremely heterogeneous. Over 70 genes have been identified to date, and with the advent of massively parallel sequencing, the pace of novel gene discovery has accelerated. In a family segregating progressive autosomal-dominant nonsyndromic hearing loss (NSHL), we used OtoSCOPE® to exclude mutations in known deafness genes and then performed segregation mapping and whole-exome sequencing to identify a unique variant, p.Ser178Leu, in TBC1D24 that segregates with the hearing loss phenotype. TBC1D24 encodes a GTPase-activating protein expressed in the cochlea. Ser178 is highly conserved across vertebrates and its change is predicted to be damaging. Other variants in TBC1D24 have been associated with a panoply of clinical symptoms including autosomal recessive NSHL, syndromic hearing impairment associated with onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS syndrome), and a wide range of epileptic disorders. PMID:24729539

Azaiez, Hela; Booth, Kevin T; Bu, Fengxiao; Huygen, Patrick; Shibata, Seiji B; Shearer, A Eliot; Kolbe, Diana; Meyer, Nicole; Black-Ziegelbein, E Ann; Smith, Richard J H

2014-07-01

265

Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays

Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol-gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol-gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices.

Kuo, Shou-Yi; Lin, Hsin-I.

2014-02-01

266

Tachyon condensation and 'bounce' in the D1-D5 system

Energy Technology Data Exchange (ETDEWEB)

We construct supergravity solutions dual to microstates of the D1-D3-D5 system with nonzero B field moduli. Just like the D1-D5 solutions in [hep-th/0109154] these solutions are generically nonsingular everywhere, with the 'throat' closing smoothly near r=0. We write expressions relating the asymptotic supergravity fields to the integral brane charges. We study the infall of a D1 brane down the throat of the geometries. This test brane 'bounces' off the smooth end for generic initial conditions. The details of the bounce depend on both the choice of D1-D3-D5 microstate and the direction of approach of the infalling D1 brane. In the dual field theory description we see that the tachyon mode starts to condense, but the tachyon bounces back up the potential hill without reaching the deepest point of the potential.

Lunin, Oleg; Mathur, Samir D.; Park, I.Y.; Saxena, Ashish E-mail: ashish@pacific.mps.ohio-state.edu

2004-02-16

267

Tachyon condensation and 'bounce' in the D1-D5 system

International Nuclear Information System (INIS)

We construct supergravity solutions dual to microstates of the D1-D3-D5 system with nonzero B field moduli. Just like the D1-D5 solutions in [hep-th/0109154] these solutions are generically nonsingular everywhere, with the 'throat' closing smoothly near r=0. We write expressions relating the asymptotic supergravity fields to the integral brane charges. We study the infall of a D1 brane down the throat of the geometries. This test brane 'bounces' off the smooth end for generic initial conditions. The details of the bounce depend on both the choice of D1-D3-D5 microstate and the direction of approach of the infalling D1 brane. In the dual field theory description we see that the tachyon mode starts to condense, but the tachyon bounces back up the potential hill without reaching the deepest point of the potential

2004-02-16

268

Development of 1-D carbon composites for plasma-facing components

International Nuclear Information System (INIS)

Carbon-based materials continue to be proposed and utilized as plasma-facing surfaces in fusion devices because of their low atomic number and superior high temperature thermal properties. This study presents results of a carbon-carbon composite development program for high heat flux surfaces using one-dimensional (1-D), high thermal conductivity materials. Thermal conductivity testing of six 1-D composites was accomplished, along with coefficient of thermal expansion (CTE) tests. Results indicate progress toward achieving composites with very high conductivity, approaching pyrolytic graphite values. Several 1-D composites have room temperature thermal conductivities which exceed 500 W/m K in the parallel-to-fiber direction. Perpendicular-to-fiber direction conductivity values were typically more that an order of magnitude lower. Experimental CTE data show values up to 10x10-6/ C perpendicular to fibers and nearly zero values in the fiber direction. Mechanical property testing will be included in future efforts. ((orig.))

1994-09-01

269

3+1D Massless Weyl spinors from bosonic scalar-tensor duality

We consider the fermionization of a bosonic free theory characterized by the 3+1D scalar - tensor duality. This duality can be interpreted as the dimensional reduction, via a planar boundary, of the 4+1D topological BF theory. In this model, adopting the Sommerfield tomographic representation of quantized bosonic fields, we explicitly build a fermionic operator and its associated Klein factor such that it satisfies the correct anticommutation relations. Interestingly, we demonstrate that this operator satisfies the massless Dirac equation and that it can be identified with a 3+1D Weyl spinor. Finally, as an explicit example, we write the integrated charge density in terms of the tomographic transformed bosonic degrees of freedom.

Amoretti, Andrea; Caruso, Giacomo; Maggiore, Nicola; Magnoli, Nicodemo

2013-01-01

270

1-D space ball array calibration methodology for coordinate measurement machine

In industry, the coordinate measuring machine (CMM) is the most confident instrument in length metrology. The device must conduct systematic precision calibration during installation and before measurement in order to ensure the measurement quality. However, the complete calibration procedure is multifarious. It requires many standard gauges and an experienced worker to finish the job. The expenditure is considerable. The purposes of this study are, first, to develop a CMM calibration tool, the 1-D space ball array plate, to carry out the calibration process, and secondly, to propose the `1-D space ball array coordinating algorithm' to compute the CMM spacial measurement error. From the actual measuring experiments, the proposed 1-D ball array plate has good repeatability and has similar functions of a step gauge. In addition, the proposed methodology conforms to the calibration specification of ISO 10360-2, and has the advantages of low fabrication cost and short calibration time. It provides a new and efficient procedure for CMM calibration.

Lee, S. J.; Chang, D. Y.

2005-01-01

271

1-D space ball array calibration methodology for coordinate measurement machine

International Nuclear Information System (INIS)

In industry, the coordinate measuring machine (CMM) is the most confident instrument in length metrology. The device must conduct systematic precision calibration during installation and before measurement in order to ensure the measurement quality. However, the complete calibration procedure is multifarious. It requires many standard gauges and an experienced worker to finish the job. The expenditure is considerable. The purposes of this study are, first, to develop a CMM calibration tool, the 1-D space ball array plate, to carry out the calibration process, and secondly, to propose the '1-D space ball array coordinating algorithm' to compute the CMM spacial measurement error. From the actual measuring experiments, the proposed 1-D ball array plate has good repeatability and has similar functions of a step gauge. In addition, the proposed methodology conforms to the calibration specification of ISO 10360-2, and has the advantages of low fabrication cost and short calibration time. It provides a new and efficient procedure for CMM calibration

2005-01-01

272

Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays.

Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol-gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol-gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices. PMID:24521308

Kuo, Shou-Yi; Lin, Hsin-I

2014-01-01

273

International Nuclear Information System (INIS)

We describe a model that generates realistic synthetic records of plausible strong ground motions, specific to the fault - station geometry. We model the slip as a superposition of randomly located sub-events. Since this source includes random parameters, we generate multiple realizations to investigate the uncertainties. In the context of the Representation Theorem, the motion is transferred to the site using synthetic Green's functions generated for a flat-layered Earth model. The Green's functions are generated using the regional velocity model, and can be modified with shallow layers to match the local site conditions. Source parameters are related energy and effective stress. Thus the parameters in the model are mostly constrained by either geological or geophysical observations. This paper also reviews several applications. The purpose of this paper is to review the method that we have been using to generate the synthetic seismograms, illustrate some applications, and discuss future directions for these studies

2003-12-22

274

Differential excitation cross section of atomic oxygen by electron impact - (3P-1D transition)

Results of an electron impact experiment in which a crossed-beam method was used to determine the differential excitation cross sections of atomic oxygen (3P-1D transition) are reported. The measurements cover energies of 7, 10, 15, 20, and 30 eV, with the angular range varying from 30 to 150 deg in 15-deg increments. The results are consistent, both in shape and in magnitude, with theoretical predictions, providing a direct confirmation of the theoretical total excitation cross sections of O(1D) state. Details of the experimental equipment and procedure are given.

Shyn, T. W.; Sharp, W. E.

1986-01-01

275

Modeling of general 1-D periodic leaky-wave antennas in layered media using EIGER.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a mixed-potential integral-equation formulation for analyzing 1-D periodic leaky-wave antennas in layered media. The structures are periodic in one dimension and finite in the other two dimensions. The unit cell consists of an arbitrary-shaped metallic/dielectric structure. The formulation has been implemented in the EIGER{trademark} code in order to obtain the real and complex propagation wavenumbers of the bound and leaky modes of such structures. Validation results presented here include a 1-D periodic planar leaky-wave antenna and a fully 3-D waveguide test case.

Wilton, Donald R. (University of Houston); Basilio, Lorena I.; Celepcikay, Ferhat T. (University of Houston); Johnson, William Arthur; Baccarelli, Paolo (Sapienza Universita de Roma); Valerio, Guido (Sapienza Universita de Roma); Paulotto, Simone (University of Houston); Langston, William L.; Jackson, David R. (University of Houston)

2010-09-01

276

Fermions tunnelling from GHS and non-extremal D1-D5 black holes

Energy Technology Data Exchange (ETDEWEB)

Recent research shows that fermions tunnelling can result in correct Hawking temperature of a black hole. In this letter, choosing a set of appropriate matrices {gamma}{sup {mu}}, we attempt to study Hawking radiation of Dirac particles across the horizons of the GHS and non-extremal five-dimensional D1-D5 black holes in string theory by using fermions tunnelling method. Finally, the expected Hawking temperatures of the GHS and non-extremal D1-D5 black holes are correctly recovered.

Jiang Qingquan [Institute of Particle Physics, Central China Normal University, Wuhan, Hubei 430079 (China)], E-mail: jiangqq@iopp.ccnu.edu.cn

2008-09-11

277

The (2 + 1)-d U(1) quantum link model masquerading as deconfined criticality

The (2 + 1)-d U(1) quantum link model is a gauge theory, amenable to quantum simulation, with a spontaneously broken SO(2) symmetry emerging at a quantum phase transition. Its low-energy physics is described by a (2 + 1)-d RP(1) effective field theory, perturbed by an SO(2) breaking operator, which prevents the interpretation of the emergent pseudo-Goldstone boson as a dual photon. At the quantum phase transition, the model mimics some features of deconfined quantum criticality, but remains linearly confining. Deconfinement only sets in at high temperature. Dedicated to the memory of Bernard B Beard (1957-2012).

Banerjee, D.; Jiang, F.-J.; Widmer, P.; Wiese, U.-J.

2013-12-01

278

International Nuclear Information System (INIS)

With deuterium present in the formyl group, the equilibrium constant for transfer of N-methylformamide from chloroform to D2O at 250C was enhanced by a factor of 3.1 +- 0.15%, as estimated independently by proton magnetic resonance and by double-labeling experiments in which 14C and 3H were incorporated alternatively into the methyl group. The distribution coefficient of acetaldehyde-1-d between D2O and the vapor phase, on the other hand, differed from that of acetaldehyde by less than 0.5%

1983-02-23

279

The Mouse Cd1d-Restricted Repertoire Is Dominated by a Few Autoreactive T Cell Receptor Families

Digital Repository Infrastructure Vision for European Research (DRIVER)

To define the phenotype and T cell receptor (TCR) repertoire of CD1d-dependent T cells, we compared the populations of T cells that persisted in major histocompatibility complex (MHC)-deficient mice, which lack mainstream T cells, with those from MHC/CD1d doubly deficient mice, which lack both mainstream and CD1d-dependent T cells. Surprisingly, up to 80% of the CD1d-dependent T cells were stained by tetramers of CD1d/?-galactosylceramide, which specifically identify the previously described...

Park, Se-ho; Weiss, Angela; Benlagha, Kamel; Kyin, Tim; Teyton, Luc; Bendelac, Albert

2001-01-01

280

Directory of Open Access Journals (Sweden)

Full Text Available Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8. Genomic in situ hybridization (GISH and fluorescence in situ hybridization (FISH confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax, and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.

Lidia B?aszczyk

2013-07-01

281

Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement. PMID:23896593

Salmanowicz, Boles?aw P; Langner, Monika; Wi?niewska, Halina; Apolinarska, Barbara; Kwiatek, Micha?; B?aszczyk, Lidia

2013-01-01

282

The antitumor effect of natural killer T cells has been reported in several studies analyzing the expression of CD1d on antigen-presenting cells (APCs). Therefore, the present study questioned whether APCs may be abnormal in the peripheral blood (PB) of acute leukemia (AL) patients, particularly the levels of CD1d. To improve the understanding of the role of CD1d on APCs, the levels of CD1d on monocytes were analyzed in healthy controls, AL patients and AL patients with complete remission (CR). In addition, the correlation between the number of CD3+CD56+ T lymphocytes and levels of CD1d on monocytes was analyzed. Flow cytometry was used to determine the levels of CD1d on monocytes and lymphocytes. A significant decrease was observed in the levels of CD1d on monocytes in the PB of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients compared with the healthy controls. Simultaneously, significantly different levels of CD1d on monocytes were identified between the CR-AML and the CR-ALL patients; the levels of CD1d on monocytes remained low in the CR-AML patients, while the levels of CD1d on monocytes recovered in the CR-ALL patients. A significantly negative correlation was observed between the number of CD3+CD56+ T lymphocytes and the levels of CD1d on monocytes in AL patients. However, a significantly positive correlation was identified between the cytotoxicity of the CD3+CD56+ T lymphocytes and the levels of CD1d on monocytes. These results suggested that the significantly low levels of CD1d on monocytes may contribute to AML and ALL progression. In addition, a significant correlation was observed between the levels of CD1d on monocytes and the number/cytotoxicity of CD3+CD56+ T lymphocytes in AML and ALL patients.

GUO, WENJIAN; DONG, AISHU; XING, CHAO; LIN, XIAOJI; PAN, XIAHUI; LIN, YING; ZHU, BAOLING; HE, MUQING; YAO, RONG-XING

2014-01-01

283

Mélange à quatre ondes en bord de bande d'un cristal photonique 1D

Nous présentons ici une expérience de mélange à quatre ondes pour la caractérisation de non-linéarités optiques du troisième ordre dans des cristaux photoniques 1D. Nous avons montré que la structuration du matériau permettait d'augmenter l'efficacité des processus non-linéaires grâce aux propriétés de localisation de la lumière en bord de bande interdite du cristal photonique.

Astic, M.; Barthelemy, P.; Träger, D.; Razzari, L.; Delaye, P.; Frey, R.; André, R.; Roosen, G.

2006-10-01

284

Pharmacological challenge with a serotonin 1D agonist in alcohol dependence

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Both animal and clinical studies have implicated serotonergic dysfunction in the pathogenesis of alcohol abuse and dependence. However the exact mechanisms involved remain unknown. Theoretically, low serotonin promotes alcohol seeking behavior. Sumatriptan is a serotonin1D agonist. It is postulated that sumatriptan's agonism at this terminal autoreceptor increases negative feedback, creating a net effect of decreased serotonergic neurotransmission. Adminis...

2005-01-01

285

Nonlinear Control of Absorption in Graphene-based 1D Photonic Crystal

Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic crystal with a monolayer graphene defect. Thanks to the large third order nonlinearity of graphene and field localization in the defect layer we demonstrate the possibility to achieve controllable, saturable absorption for the pump frequency.

Vincenti, M A; Grande, M; D'Orazio, A; Scalora, M

2013-01-01

286

Glucose sensor using periodic nanostructured hybrid 1D Au/ZnO arrays

International Nuclear Information System (INIS)

Hybrid 1D nanostructured Au/ZnO arrays were created by heat treatment of a spin-coated zinc acetate-PVA-Au(III) layer on surface relief grating and functioned as an electrochemical and optical D(+)-glucose sensor due to electrochemical oxidation between hybrid nanostructures and D(+)-glucose. The morphology and chemical composition of 1D Au/ZnO hybrid arrays were characterized by means of AFM, SEM, EDAX, and XPS. Electrochemical and optical sensitivities by the addition of D(+)-glucoses on 1D Au/ZnO arrays were investigated using Cyclic voltammetry and UV–vis-NIR spectra in the medical concentration ranges of 0.5, 2.0, and 8.0 mM. - Highlights: ? Zinc acetate-PVA-Au(III) composites were prepared by simply mixing zinc acetate-PVA and gold(III) chloride trihydrate. ? Hybrid 1D nanostructured Au/ZnO arrays were easily fabricated using surface relief gratings without additional process steps. ? Redox and optical sensor to detect D(+)-glucoses.

2012-07-01

287

A new 1D approximation for the solution of 2D radiative transfer problems

International Nuclear Information System (INIS)

The simplified M-1D algorithm (M stands for modified) for the calculation of horizontal distribution of reflected brightness coefficient in 2D regions with large homogeneous pixels is presented. This algorithm is based upon modified 3*N-1 1D-transport equations (where N is the number of large pixels) instead of one 2D-transport equation, usually used in such problems. The method does not rely on empiric assumptions on both optical properties of atmosphere or diffuse radiation intensity. Numerical results demonstrating the accuracy of the presented algorithm for simulating brightening and shadowing effects in a vicinity of the jump of optical properties given. The accuracy of the M-1D approximation strongly depends on the geometry and illumination conditions. However, it remains below 15% and can reach 1% for all cases studied and is strongly higher than the accuracy of usually employed independent pixel approximation. Time reduction via replacing 2D problem via modified 1D problem is about 17 times for all cases considered in this paper.

2010-03-01

288

The effective potential of components of the curl of an antisymmetric tensor coupled to gravity in D dimensions is evaluated in a 1/D expansion. For large D, only highest-rank propagators contribute to leading order, while multiloop diagrams are suppresse...

O. Foda

1984-01-01

289

Comparison between 3D and 1D simulations of a regenerative blower for fuel cell applications

International Nuclear Information System (INIS)

Highlights: ? A hydrogen recirculation blower for automotive fuel cells applications is studied. ? A 3D CFD analysis has been carried out to better understand the internal flows of the machine. ? The CFD results are compared to a 1D model set up by the authors in previous works. ? The main hypotheses put forward for the theoretical 1D model are compatible with the 3D analysis. - Abstract: A 3D Computational Fluid Dynamics (CFD) analysis has been carried out to better understand the internal fluid dynamics of a regenerative blower used for hydrogen recirculation in a Proton Exchange Membrane (PEM), Fuel Cell (FC) utilized for automotive applications. The obtained results are used to highlight the motion of the fluid in the vanes and in the side channel of the machine and to verify the main hypotheses put forward concerning the theoretical 1D model set up by the authors in previous works on the basis of the momentum exchange theory. Finally, the CFD analysis has been used to point out the effect of the slope of the vanes on the performance of the regenerative blower, and the results have been compared with those obtained using of the 1D model.

2012-03-01

290

UBV photometry of new H-alpha stars in the association Orion OB1d

Energy Technology Data Exchange (ETDEWEB)

UBV data are given for 92 new stars with H-alpha in emission found recently by Parsamyan and Chavira (1982) in the association Orion OB1d. The limiting magnitude in U is 17.7m. The positions of these stars in the Hertzsprung-Russell diagram and in the two-color (U - B, B - V) diagram are given. 9 references.

Gasparian, K.G.

1985-09-01

291

1-D Transport Model for Analysis of Expanding Radius and Full Bore Startup of Tokamak Plasmas.

This report describes the physics models and numerical algorithms that have been used in the WHIST one-dimensional (1-D) transport code to study expanding radius vs full bore startup scenarios for tokamak plasmas. The phase of the tokamak discharge that i...

A. T. Mense W. A. Houlberg S. E. Attenberger

1980-01-01

292

Boltzmann Equation in 1D-Spherical and Cylindrical Geometry. Specifications of the ORPHEE Code.

Specifications of ORPHEE (a neutronic time-independent code for 1D-spherical or cylindrical-geometry) are given. The various forms of Boltzmann's equation, with respect to the kind of symmetry are presented. The development of the anisotropic source is st...

D. Verwaerde

1981-01-01

293

Boltzmann equation in 1D-spherical and cylindrical geometry. Specifications of the ORPHEE code

International Nuclear Information System (INIS)

Specifications of ORPHEE (a neutronic time-independent code for 1D-spherical or cylindrical-geometry) are given. The various forms of Boltzmann's equation, with respect to the kind of symmetry are presented. The development of the anisotropic source is studied and then it is shown how to build finite difference schemes in order to get a good approximation of this equation

1981-01-01

294

1D Schr\\"odinger operator with periodic plus compactly supported potentials

We consider the 1D Schr\\"odinger operator $Hy=-y''+(p+q)y$ with a periodic potential $p$ plus compactly supported potential $q$ on the real line. The spectrum of $H$ consists of an absolutely continuous part plus a finite number of simple eigenvalues in each spectral gap $\\g_n\

Korotyaev, Evgeny

2009-01-01

295

Silencing of TBC1D15 promotes RhoA activation and membrane blebbing.

Membrane blebs are round-shaped dynamic membrane protrusions that occur under many physiological conditions. Membrane bleb production is primarily controlled by actin cytoskeletal rearrangements mediated by RhoA. Tre2-Bub2-Cdc16 (TBC) domain-containing proteins are negative regulators of the Rab family of small GTPases and contain a highly conserved TBC domain. In this report, we show that the expression of TBC1D15 is associated with the activity of RhoA and the production of membrane blebs. Depletion of TBC1D15 induced activation of RhoA and membrane blebbing, which was abolished by the addition of an inhibitor for RhoA signaling. In addition, we show that TBC1D15 is required for the accumulation of RhoA at the equatorial cortex for the ingression of the cytokinetic furrow during cytokinesis. Our results demonstrate a novel role for TBC1D15 in the regulation of RhoA during membrane blebbing and cytokinesis. PMID:24337944

Takahara, Yuko; Maeda, Masao; Hasegawa, Hitoki; Ito, Satoko; Hyodo, Toshinori; Asano, Eri; Takahashi, Masahide; Hamaguchi, Michinari; Senga, Takeshi

2014-04-01

296

The D1-D2 region of the large subunit ribosomal DNA as barcode for ciliates.

Ciliates are a major evolutionary lineage within the alveolates, which are distributed in nearly all habitats on our planet and are an essential component for ecosystem function, processes and stability. Accurate identification of these unicellular eukaryotes through, for example, microscopy or mating type reactions is reserved to few specialists. To satisfy the demand for a DNA barcode for ciliates, which meets the standard criteria for DNA barcodes defined by the Consortium for the Barcode of Life (CBOL), we here evaluated the D1-D2 region of the ribosomal DNA large subunit (LSU-rDNA). Primer universality for the phylum Ciliophora was tested in silico with available database sequences as well as in the laboratory with 73 ciliate species, which represented nine of 12 ciliate classes. Primers tested in this study were successful for all tested classes. To test the ability of the D1-D2 region to resolve conspecific and congeneric sequence divergence, 63 Paramecium strains were sampled from 24 mating species. The average conspecific D1-D2 variation was 0.18%, whereas congeneric sequence divergence averaged 4.83%. In pairwise genetic distance analyses, we identified a D1-D2 sequence divergence of barcode for ciliated protists. PMID:24165195

Stoeck, T; Przybos, E; Dunthorn, M

2014-05-01

297

A novel ferromagnetic 1D dysprosium chain was synthesized. It exhibits slow magnetic relaxation, originating from the single-ion behaviour of Dy(3+) as indicated by dc and ac magnetic data of both diluted and un-diluted samples. PMID:24769724

Jia, Li; Chen, Qi; Meng, Yin-Shan; Sun, Hao-Ling; Gao, Song

2014-06-01

298

A derivation of Akcasu's 'MLP' equations for 1-D particle transport in stochastic media

International Nuclear Information System (INIS)

This paper presents a new derivation of Akcasu's Modified Levermore-Pomraning (MLP) model for estimating the ensemble-averaged angular flux for particle transport problems in 1-D geometrically random media. The significant new feature of the MLP equations is that, unlike the earlier Levermore-Pomraning (LP) model, the MLP equations are exact for certain classes of problems with scattering. (authors)

2007-04-15

299

Fresnel Lenses fabricated by femtosecond laser micromachining on Polymer 1D Photonic Crystal

Directory of Open Access Journals (Sweden)

Full Text Available We report the fabrication of micro Fresnel lenses by femtosecond laser surface ablation on polymer 1D photonic crystals. This device is designed to focus the transmitted wavelength of the photonic crystal and filter the wavelengths corresponding to the photonic band gap region. Integration of such devices in a wavelength selective light harvesting and filtering microchip can be achieved.

Guduru Surya S.K.

2013-11-01

300

Non-linear Finite-Frequency Waveform Inversion for 1-D Structures

One-dimensional velocity models are representative of regional tectonic units. They are important in determining the locations and focal mechanisms of earthquakes, and provide initial models for tomographic studies. We develop a new approach to the non-linear inversion of finite-frequency traveltimes and amplitudes for 1-D models. Frequency-dependent traveltime and amplitude anomalies are measured by cross-correlation of three-component synthetic and recorded waveforms windowed around body and surface waves. Sensitivity kernels to parameters involved in the 1-D model, such as P- and S-wave speeds and depths of seismic discontinuities, are computed numerically by perturbing the reference model and measuring the resulting traveltime and amplitude perturbations, thus avoiding the invocation of Born approximation. An iterative inversion is carried out with updates of traveltime and amplitude measurements and sensitivity kernels following each iteration. We apply this new approach to the inversion of 1D structures around the source region of the May 12, 2008, Wenchuan earthquake. Numerous moderate aftershocks (Mw=5-6) and densely deployed broadband stations provide plenty of records for obtaining 1-D models along a variety of source-receiver path, revealing lateral structural variations in both the Tibetan Plateau and Sichuan Basin.

Wan, K.; Ni, S.; Zhao, L.

2010-12-01

301

On Eigenvalue spacings for the 1-D Anderson model with singular site distribution

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study eigenvalue spacings and local eigenvalue statistics for 1D lattice Schrodinger operators with Holder regular potential, obtaining a version of Minami's inequality and Poisson statistics for the local eigenvalue spacings. The main additional new input are regular properties of the Furstenberg measures and the density of states obtained in some of the author's earlier work.

Bourgain, Jean

2013-01-01

302

A simple 1D model with thermomechanical coupling for superelastic SMAs

International Nuclear Information System (INIS)

This paper presents an outline for a new uniaxial model for shape memory alloys that accounts for thermomechanical coupling. The coupling provides an explanation of the dependence of SMA behavior on the loading rate. 1D simulations are carried in Matlab using simple finite-difference discretization of the mechanical and thermal equations.

2010-06-01

303

Well-posedness of 1-D compressible Euler-Poisson equations with physical vacuum

This paper is concerned with the 1-D compressible Euler-Poisson equations with moving physical vacuum boundary condition. It is usually used to describe the motion of a self-gravitating inviscid gaseous star. The local well-posedness of classical solutions is established in the case of the adiabatic index $1<\\gamma<3$.

Gu, Xumin

2011-01-01

304

Clifford algebras and the minimal representations of the 1D N-extended supersymmetry algebra

Energy Technology Data Exchange (ETDEWEB)

The Atiyah-Bott-Shapiro classification of the irreducible Clifford algebra is used to derive general properties of the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z{sub 2}-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. (author)

Toppan, Francesco [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: toppan@cbpf.br

2008-07-01

305

Minimal representations of supersymmetry and 1D N-extended {sigma}-models

Energy Technology Data Exchange (ETDEWEB)

We discuss the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z{sub 2}-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. Their knowledge allows to construct one-dimensional sigma-models with extended off-shell supersymmetries without using superfields (author)

Toppan, Francesco

2008-07-01

306

International Nuclear Information System (INIS)

Two novel interesting d 1 metal coordination polymers, [Zn(H2bibzim)(BDC)] n (1) and [Cd(H2bibzim)(BDC)] n (2) [H2bibzim=2,2'-bibenzimidazole, BDC=1,4-benzenedicarboxylate] have been synthesized under solvothermal conditions and structurally characterized. Both 1 and 2 are constructed from infinite neutral zigzag-like one-dimensional (1D) chains. The ?-? interactions and interchain hydrogen-bonding interactions further extend the 1D arrangement to generate a 3D supramolecular architecture for 1 and 2. Both complexes have high thermal stability and display strong blue fluorescent emissions in the solid state upon photo-excitation at 365 nm at room temperature. They are the first two examples that 2,2'-bibenzimidazole has been introduced into the d 1 coordination polymeric framework

2005-11-01

307

We have analyzed the 1 u( 1D) and 2 u( 1D) ion-pair states of I 2 by perturbation-facilitated optical-optical double resonance using the B3?(0 u+)˜ c1 g mixing state as an intermediate. The double-resonance spectra exhibited the strong vibrational progression to the 1 u( 1D) state in accord with the ??=0 propensity rule for the valence to ion-pair state transitions. With the state selection in the intermediate state, each progression shows a simple rotational structure consisting of P and R doublets, while the extra lines were found in some vibrational states. We interpreted the occurrence of the extra lines as the interaction with the 2 u( 1D) state lying closely and extended our observation to its lower vibrational states. Finally we identified the 1 u( 1D) state in the 0? v?31 range and the 2 u( 1D) state in the 0? v?9 range, and analyzed their energy levels including the heterogenous interaction. The 1 u( 1D)-2 u( 1D) interaction was found to be described in the pure precession approximation and the precious molecular constants were reported for the 1 u( 1D) and 2 u( 1D) ion-pair states.

Motohiro, Satoshi; Umakoshi, Akimitsu; Ishiwata, Takashi

2001-08-01

308

C1D is a gamma-irradiation inducible nuclear matrix protein that interacts with and activates the DNA-dependent protein kinase (DNA-PK) that is essential for the repair of the DNA double-strand breaks and V(D)J recombination. Recently, it was demonstrated that C1D can also interact with TRAX and prevent the association of TRAX with Translin, a factor known to bind DNA break-point junctions, and that over expression of C1D can induce p53-dependent apoptosis. Taken together, these findings suggest that mammalian C1D could be involved in maintenance of genome integrity by regulating the activity of proteins involved in DNA repair and recombination. To obtain direct evidence for the biological function of C1D that we show is highly conserved between diverse species, we have analysed the Saccharomyces cerevisiae C1D homologue. We report that the disruption of the YC1D gene results in a temperature sensitivity and that yc1d mutant strains exhibit defects in non-homologous DNA end joining (NHEJ) and accurate DNA repair. In addition, using a novel plasmid-based in vivo recombination assay, we show that yc1d mutant strains are also defective in homologous recombination. These results indicate that YC1D is implicated in both homologous recombination and NHEJ pathways for the repair of DNA double-strand breaks. PMID:12421302

Erdemir, Tuba; Bilican, Bilada; Cagatay, Tolga; Goding, Colin R; Yavuzer, Ugur

2002-11-01

309

International Nuclear Information System (INIS)

NEWT1D, a one dimensional multifluid model of the scrape-off layer and divertor plasma, has been used to model the plasma including the distribution of carbon ionization states in the SOL and divertor of ELMing H-mode at two injected power levels in DIII-D. Comparison of the code predictions to the measured divertor and scrape-off layer (SOL) plasma density and temperature shows good agreement. Comparison of the predicted line emissions to the spectroscopic data suggests that physically sputtered carbon from the strike point is not transported up the flux tube; a distributed source of carbon a few centimeters up the flux tube is required to achieve reasonable agreement

1996-06-24

310

The physiological responses of chemostat cultures of the filamentous fungus, Aspergillus niger (B1-D) to simulated and actual oxidative stress, imposed respectively by addition of exogenous menadione (MD; a superoxide radical generating reagent) and gassing the culture with oxygen enriched air (25%, 50%, 75%, and 100% [v/v]), were examined. Changes in the levels of intracellular superoxide anions and defensive enzyme activities, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), were monitored, together with glutathione and respiratory activity in both the dynamic phase and when a new steady state was established. Culture response to MD addition was distinct from that upon exposure to enriched oxygen conditions, in that MD caused elevated levels of intracellular protein, whereas oxygen enrichment caused reduced protein content, especially at low dilution rates. An unexpectedly low level of superoxide radical was found in oxygen-enriched steady-state cultures (>/=50%) at a range of dilution rates, which was not caused by elevated SOD activity. Under these conditions, it was noted that the ratio of rotenone-insensitive/total respiration increased, suggesting increased activity of the alternative respiratory pathway. This may have had the effect of reducing the endogenous generation of superoxide radicals under oxygen rich conditions, but also may have reduced the ATP yield due to the non-proton-pumping nature of the alternative respiratory pathway. Thus, the negative culture effects noted in many studies at high oxygen levels may not simply be due to elevated endogenous superoxide generation, but could be in part due to the consequences of metabolic changes in the culture that seek to minimize superoxide generation. The dynamic culture response was characterized by rapid elevation of intracellular superoxide anions and associated protective enzymes, especially SOD, and was clearly distinct from the adaptive response just described. PMID:12673769

Bai, Zhonghu; Harvey, Linda M; McNeil, Brian

2003-06-20

311

The effect of disease associated point mutations on 5?-reductase (AKR1D1) enzyme function

The stereospecific 5?-reduction of ?4-3-ketosterols is very difficult to achieve chemically and introduces a 90° bend between ring A and B of the planar steroid. In mammals, the reaction is catalyzed by steroid 5?-reductase, a member of the aldo-keto reductase (AKR) family. The human enzyme, AKR1D1, plays an essential role in bile-acid biosynthesis since the 5?-configuration is required for the emulsifying properties of bile. Deficient 5?-reductase activity can lead to cholestasis and neo-natal liver failure and is often lethal if it remains untreated. In five patients with 5?-reductase deficiency, sequencing revealed individual, non-synonymous point mutations in the AKR1D1 gene: L106F, P133R, G223E, P198L and R261C. However, mapping these mutations to the AKR1D1 crystal structure failed to reveal any obvious involvement in substrate or cofactor binding or catalytic mechanism, and it remained unclear whether these mutations could be causal for the observed disease. We analyzed the positions of the reported mutations and found that they reside in highly conserved portions of AKR1D1 and hypothesized that they would likely lead to changes in protein folding, and hence enzyme activity. Attempts to purify the mutant enzymes for further characterization by over-expression in E.coli yielded sufficient amounts of only one mutant (P133R). This enzyme exhibited reduced Km and kcat with the bile acid intermediate ?4-cholesten-7?-ol-3-one as substrate reminiscent of uncompetitive inhibition. In addition, P133R displayed no change in cofactor affinity but was more thermolabile as judged by CD-spectroscopy. When all AKR1D1 mutants were expressed in HEK 293 cells, protein expression levels and enzyme activity were dramatically reduced. Furthermore, cycloheximide treatment revealed decreased stability of several of the mutants compared to wild type. Our data show, that all five mutations identified in patients with functional bile acid deficiency strongly affected AKR1D1 enzyme functionality and therefore may be causal for this disease.

Mindnich, Rebekka; Drury, Jason E.; Penning, Trevor M.

2011-01-01

312

TBC1D5 and the AP2 complex regulate ATG9 trafficking and initiation of autophagy.

The RabGAP protein TBC1D5 controls cellular endomembrane trafficking processes and binds the retromer subunit VPS29 and the ubiquitin-like protein ATG8 (LC3). Here, we describe that TBC1D5 also associates with ATG9 and the active ULK1 complex during autophagy. Moreover, ATG9 and TBC1D5 interact with clathrin and the AP2 complex. Depletion of TBC1D5 leads to missorting of ATG9 to late endosomes upon activation of autophagy, whereas inhibition of clathrin-mediated endocytosis or AP2 depletion alters ATG9 trafficking and its association with TBC1D5. Taken together, our data show that TBC1D5 and the AP2 complex are important novel regulators of the rerouting of ATG9-containing vesicular carriers toward sites of autophagosome formation. PMID:24603492

Popovic, Doris; Dikic, Ivan

2014-04-01

313

Early-onset epileptic encephalopathies (EOEEs) are a group of rare devastating epileptic syndromes of infancy characterized by severe drug-resistant seizures and electroencephalographic abnormalities. The current study aims to determine the genetic etiology of a familial form of EOEE fulfilling the diagnosis criteria for malignant migrating partial seizures of infancy (MMPSI). We identified two inherited novel mutations in TBC1D24 in two affected siblings. Mutations severely impaired TBC1D24 expression and function, which is critical for maturation of neuronal circuits. The screening of TBC1D24 in an additional set of eight MMPSI patients was negative. TBC1D24 loss of function has been associated to idiopathic infantile myoclonic epilepsy, as well as to drug-resistant early-onset epilepsy with intellectual disability. Here, we describe a familial form of MMPSI due to mutation in TBC1D24, revealing a devastating epileptic phenotype associated with TBC1D24 dysfunction. PMID:23526554

Milh, Mathieu; Falace, Antonio; Villeneuve, Nathalie; Vanni, Nicola; Cacciagli, Pierre; Assereto, Stefania; Nabbout, Rima; Benfenati, Fabio; Zara, Federico; Chabrol, Brigitte; Villard, Laurent; Fassio, Anna

2013-06-01

314

Digital Repository Infrastructure Vision for European Research (DRIVER)

Myeloid antigen-presenting cells (APC) express CD1d molecules that present exogenous and endogenous lipid antigens that activate CD1d-restricted T cells, natural killer T (NKT) cells. NKT cell activation has been shown to mediate the potent downstream activation of other immune cells through cell–cell interactions and rapid, prolific cytokine production. Foreign antigens are not required for NKT cell activation. The endogenous lipids bound to CD1d are sufficient for activation of NKT cells ...

Muindi, Karen; Cernadas, Manuela; Watts, Gerald F. M.; Royle, Louise; Neville, David C. A.; Dwek, Raymond A.; Besra, Gurdyal S.; Rudd, Pauline M.; Butters, Terry D.; Brenner, Michael B.

2010-01-01

315

Insulin stimulates the translocation of the glucose transporter GLUT4 from intracellular locations to the plasma membrane in adipose and muscle cells. Prior studies have shown that Akt phosphorylation of the Rab GTPase-activating protein, AS160 (160-kDa Akt substrate; also known as TBC1D4), triggers GLUT4 translocation, most likely by suppressing its Rab GTPase-activating protein activity. However, the regulation of a very similar protein, TBC1D1 (TBC domain family, member 1), which is mainly found in muscle, in insulin-stimulated GLUT4 translocation has been unclear. In the present study, we have identified likely Akt sites of insulin-stimulated phosphorylation of TBC1D1 in C2C12 myotubes. We show that a mutant of TBC1D1, in which several Akt sites have been converted to alanine, is considerably more inhibitory to insulin-stimulated GLUT4 translocation than wild-type TBC1D1. This result thus indicates that similar to AS160, Akt phosphorylation of TBC1D1 enables GLUT4 translocation. We also show that in addition to Akt activation, activation of the AMP-dependent protein kinase partially relieves the inhibition of GLUT4 translocation by TBC1D1. Finally, we show that the R125W variant of TBC1D1, which has been genetically associated with obesity, is equally inhibitory to insulin-stimulated GLUT4 translocation, as is wild-type TBC1D1, and that healthy and type 2 diabetic individuals express approximately the same level of TBC1D1 in biopsies of vastus lateralis muscle. In conclusion, phosphorylation of TBC1D1 is required for GLUT4 translocation. Thus, the regulation of TBC1D1 resembles that of its paralog, AS160.

Peck, Grantley R.; Chavez, Jose A.; Roach, William G.; Budnik, Bogdan A.; Lane, William S.; Karlsson, Hakan K. R.; Zierath, Juleen R.; Lienhard, Gustav E.

2009-01-01

316

Insulin stimulates the translocation of the glucose transporter GLUT4 from intracellular locations to the plasma membrane in adipose and muscle cells. Prior studies have shown that Akt phosphorylation of the Rab GTPase-activating protein, AS160 (160-kDa Akt substrate; also known as TBC1D4), triggers GLUT4 translocation, most likely by suppressing its Rab GTPase-activating protein activity. However, the regulation of a very similar protein, TBC1D1 (TBC domain family, member 1), which is mainly found in muscle, in insulin-stimulated GLUT4 translocation has been unclear. In the present study, we have identified likely Akt sites of insulin-stimulated phosphorylation of TBC1D1 in C2C12 myotubes. We show that a mutant of TBC1D1, in which several Akt sites have been converted to alanine, is considerably more inhibitory to insulin-stimulated GLUT4 translocation than wild-type TBC1D1. This result thus indicates that similar to AS160, Akt phosphorylation of TBC1D1 enables GLUT4 translocation. We also show that in addition to Akt activation, activation of the AMP-dependent protein kinase partially relieves the inhibition of GLUT4 translocation by TBC1D1. Finally, we show that the R125W variant of TBC1D1, which has been genetically associated with obesity, is equally inhibitory to insulin-stimulated GLUT4 translocation, as is wild-type TBC1D1, and that healthy and type 2 diabetic individuals express approximately the same level of TBC1D1 in biopsies of vastus lateralis muscle. In conclusion, phosphorylation of TBC1D1 is required for GLUT4 translocation. Thus, the regulation of TBC1D1 resembles that of its paralog, AS160. PMID:19740738

Peck, Grantley R; Chavez, Jose A; Roach, William G; Budnik, Bogdan A; Lane, William S; Karlsson, Håkan K R; Zierath, Juleen R; Lienhard, Gustav E

2009-10-30

317

Quantization of coupled 1D vector modes in integrated photonic waveguides

International Nuclear Information System (INIS)

A quantum mechanical analysis of the guided light in integrated photonics waveguides is presented. The analysis is made starting from one-dimensional (1D) guided vector modes by taking into account the modal orthonormalization property on a cross section of an optical waveguide, the vector structure of the guided optical modes and the reversal-time symmetry in order to quantize the 1D vector modes and to derive the quantum momentum operator and the Heisenberg equations. The results provide a quantum-consistent formulation of the linear and nonlinear quantum light propagations as a function of forward and backward creation and annihilation operators in integrated photonics. As an illustration, an application to an integrated nonlinear directional coupler is given, that is, both the nonlinear momentum and the Heisenberg equations of the nonlinear coupler are derived

2008-06-01

318

Assessment of core thermo-hydrodynamic models of REFLA-1D with CCTF data

International Nuclear Information System (INIS)

In order to assess the core thermo-hydrodynamic models of REFLA-1D/MODE3, which is the latest version of REFLA-1D, several calculations of the core thermo-hydrodynamics have been performed for the CCTF Core-I series tests. The measured initial and boundary conditions were used for these calculations. The calculational results showed that the water accumulation model of Case 2 could predict the CCTF results fairly well as it could for the JAERI small scale facility. The calculated results for the base case and the EM tests were in good agreement with the CCTF data. The parameter effects, such as system pressure, initial clad temperature, Acc injection rate, LPCI injection rate and initial down-comer wall temperature, were predicted correctly, except for the high system pressure and the high LPCI injection rate tests. (author)

1983-01-01

319

L-694,247: a potent 5-HT1D receptor agonist.

Digital Repository Infrastructure Vision for European Research (DRIVER)

1. The 5-hydroxytryptamine (5-HT) receptor binding selectivity profile of a novel, potent 5-HT1D receptor agonist, L-694,247 (2-[5-[3-(4-methylsulphonylamino)benzyl-1,2,4-oxadiazol-5-yl ]- 1H-indole-3-yl]ethylamine) was assessed and compared with that of the 5-HT1-like receptor agonist, sumatriptan. 2. L-694,247 had an affinity (pIC50) of 10.03 at the 5-HT1D binding site and 9.08 at the 5-HT1B binding site (sumatriptan: pIC50 values 8.22 and 5.94 respectively). L-694,247 retained good selecti...

1993-01-01

320

D1/D5 system and Wilson Loops in (Non-)commutative Gauge Theories

We study the behavior of the Wilson loop in the (5+1)-dimensional supersymmetric Yang-Mills theory with the presence of the solitonic object. Using the dual string description of the Yang-Mills theory that is given by the D1/D5 system, we estimate the Wilson loops both in the temporal and spatial cases. For the case of the temporal loop, we obtain the velocity dependent potential. For the spatial loop, we find that the area law is emerged due to the effect of the D1-branes. Further, we consider D1/D5 system in the presence of the constant $B$ field. It is found that the Wilson loop obeys the area law for the effect of the noncommutativity.

Takahashi, H; Suzuki, K; Takahashi, Hidenori; Nakajima, Tadahito; Suzuki, Kenji

2002-01-01

321

All the supersymmetric solutions of N=1,d=5 ungauged supergravity

We classify the supersymmetric solutions of ungauged N=1 d=5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstrom black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N=2,d=4 solutions. Our formulae allows the uplifting of certain N=2,d=4 black holes to N=1,d=5 black holes on KK monopoles or to pp-waves propagating along black strings.

Bellorin, J; Ortín, T

2007-01-01

322

All the supersymmetric solutions of N = 1, d = 5 ungauged supergravity

Energy Technology Data Exchange (ETDEWEB)

We classify the supersymmetric solutions of ungauged N = 1 d = 5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstroem black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N = 2, d = 4 solutions. Our formulae allows the uplifting of certain N = 2, d = 4 black holes to N = 1, d = 5 black holes on KK monopoles or to pp-waves propagating along black strings.

Bellorin, Jorge; Meessen, Patrick; Ortin, Tomas [Instituto de Fisica Teorica UAM/CSIC, Facultad de Ciencias C-XVI, C.U. Cantoblanco, E-28049-Madrid (Spain)

2007-01-15

323

All the supersymmetric solutions of N = 1, d = 5 ungauged supergravity

International Nuclear Information System (INIS)

We classify the supersymmetric solutions of ungauged N = 1 d = 5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstroem black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N = 2, d = 4 solutions. Our formulae allows the uplifting of certain N = 2, d = 4 black holes to N = 1, d = 5 black holes on KK monopoles or to pp-waves propagating along black strings

2007-01-01

324

Modeling of the diffraction pattern of 1D-disordered silicon carbide

International Nuclear Information System (INIS)

A method for calculating the diffraction pattern of a 1D-disordered crystal structure is considered by the example of silicon carbide. One-dimensional disordering is described using a cell setting the mutual position of all close-packed crystal layers. Two models of structure disordering during the polytypic transformation of the silicon carbide cubic modification into hexagonal are discussed. The results of the calculation of the diffraction spectrum in different stages of polytypic transformation are reported. It is shown that 1D disordering leads to the formation of a set of weak diffraction reflections. The experimentally observed changes in the diffraction pattern can be interpreted within the hypothesis on crystal structure disordering through displacement of adjacent close-packed layers.

2008-09-01

325

Experimental validation of Villain's conjecture about magnetic ordering in quasi-1D helimagnets

Energy Technology Data Exchange (ETDEWEB)

Low-temperature magnetic susceptibility, zero-field muon spin resonance and specific heat measurements have been performed in the quasi-one-dimensional (1D) molecular helimagnetic compound Gd(hfac){sub 3}NITEt. The specific heat presents two anomalies at T{sub 0}=2.19(2)K and T{sub N}=1.88(2)K, while susceptibility and zero-field muon spin resonance show anomalies only at T{sub N}=1.88(2)K. The results suggest an experimental validation of Villain's conjecture of a two-step magnetic ordering in quasi-1D XY helimagnets: the paramagnetic phase and the helical spin solid phases are separated by a chiral spin liquid, where translational invariance is broken without violation of rotational invariance.

Cinti, F., E-mail: fabio.cinti@fi.infn.i [CNISM and Department of Physics, University of Florence, 50019 Sesto Fiorentino (Italy); CNR-INFM S3 National Research Center, I-41100 Modena (Italy); Rettori, A. [CNISM and Department of Physics, University of Florence, 50019 Sesto Fiorentino (Italy); CNR-INFM S3 National Research Center, I-41100 Modena (Italy); Pini, M.G. [ISC-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Mariani, M.; Micotti, E. [Department of Physics A. Volta and CNR-INFM, University of Pavia, Via Bassi 6, I-27100 Pavia (Italy); Lascialfari, A. [Department of Physics A. Volta and CNR-INFM, University of Pavia, Via Bassi 6, I-27100 Pavia (Italy); Institute of General Physiology and Biological Chemistry, University of Milano, Via Trentacoste 2, I-20134 Milano (Italy); CNR-INFM S3 National Research Center, I-41100 Modena (Italy); Papinutto, N. [CIMeC, University of Trento, Via delle Regole, 101 38060 Mattarello (Italy); Department of Physics A. Volta and CNR-INFM, University of Pavia, Via Bassi 6, I-27100 Pavia (Italy); Amato, A. [Paul Scherrer Institute, CH-5232 Villingen PSI (Switzerland); Caneschi, A.; Gatteschi, D. [INSTM R.U. Firenze and Department of Chemistry, University of Florence, Via della Lastruccia 3, I-50019 Sesto Fiorentino (Italy); Affronte, M. [CNR-INFM S3 National Research Center, I-41100 Modena (Italy); Department of Physics, University of Modena and Reggio Emilia Via Campi 213/A, I-41100 Modena (Italy)

2010-05-15

326

Structurally unstable regular dynamics in 1D piecewise smooth maps, and circle maps

International Nuclear Information System (INIS)

Highlights: ? A discontinuous 1D map with two discontinuity points is considered. ? Dynamic behaviors are either periodic or quasiperiodic. ? Dynamics are always structurally unstable. ? Any small perturbation in one of the parameters leads to different dynamics. - Abstract: In this work we consider a simple system of piecewise linear discontinuous 1D map with two discontinuity points: X? = aX if ?X? z, where a and b can take any real value, and may have several applications. We show that its dynamic behaviors are those of a linear rotation: either periodic or quasiperiodic, and always structurally unstable. A generalization to piecewise monotone functions X? = F(X) if ?X? z is also given, proving the conditions leading to a homeomorphism of the circle.

2012-11-01

327

Collective mode damping and viscosity in a 1D unitary Fermi gas

We calculate the damping of the Bogoliubov-Anderson mode in a one-dimensional two-component attractive Fermi gas for arbitrary coupling strength within a quantum hydrodynamic approach. Using the Bethe-Ansatz solution of the 1D BCS-BEC crossover problem, we derive analytic results for the viscosity covering the full range from a Luther-Emery liquid of weakly bound pairs to a Lieb-Liniger gas of strongly bound bosonic dimers. At the unitarity point, the system is a Tonks-Girardeau gas with a universal constant $\\alpha_{\\zeta}=0.38$ in the viscosity $\\zeta=\\alpha_{\\zeta}\\hbar n$ for T=0. For the trapped case, we calculate the Q-factor of the breathing mode and show that the damping provides a sensitive measure of temperature in 1D Fermi gases.

Punk, M

2006-01-01

328

Single-particle excitation spectrum in 1D ultracold fermionic optical lattices

We investigate the properties of fermions trapped in a one-dimensional (1D) optical lattice by using the density-matrix renormalization (DMRG) group method. Owing to a harmonic confinement potential inherent in real experiments, system becomes inhomogeneous structure. Under certain conditions for weak-repulsive interaction, we find that the single-particle excitation spectrum structure changes to band branching and discrete bound-state states as increasing the trap strength. Additionally, we consider the case of strong-repulsive interacting regimes which local density profile show coexist with central Mott-plateau phase with surrounded by metallic regions. As increasing the trap strength, we find the breakdown of 1D Tomonaga-Luttinger (TL) liquid which is alternative to an effective doping into the Mott phase. We will present the various kinds of striking spectra, show the comparison of repulsive interaction case with attractive interaction one.

Yamamoto, Atsushi; Yamada, Susumu; Machida, Masahiko

2012-12-01

329

Static sign language recognition using 1D descriptors and neural networks

A frame work for static sign language recognition using descriptors which represents 2D images in 1D data and artificial neural networks is presented in this work. The 1D descriptors were computed by two methods, first one consists in a correlation rotational operator.1 and second is based on contour analysis of hand shape. One of the main problems in sign language recognition is segmentation; most of papers report a special color in gloves or background for hand shape analysis. In order to avoid the use of gloves or special clothing, a thermal imaging camera was used to capture images. Static signs were picked up from 1 to 9 digits of American Sign Language, a multilayer perceptron reached 100% recognition with cross-validation.

Solís, José F.; Toxqui, Carina; Padilla, Alfonso; Santiago, César

2012-10-01

330

Hyperfine structures of the nd _1D(n = 3 - 8) states of _3He I

International Nuclear Information System (INIS)

We have used the beam-foil quantum beat method to measure the hyperfine structure separations F = 3/2 - 5/2 of the 1snd _1D states (n = 3 - 8) of _3He I. We observed the single frequency modulated decay curves of the 1s2p _1P - 1snd _1D transitions for times after excitation up to 50 ns, corresponding to 4 to 5 modulation periods. The frequencies obtained (with a precision of 2 to 5%) are compared with other experiments and theory. The frequencies are determined mainly by the singlet-triplet energy separations and mixing factors for the He I D-states. The results agree with the same parameters obtained from other recent level-crossing measurements in strong magnetic field mixing of the singlet-triplet states

1981-08-17

331

Shock waves in a 1D Bose gas: from a BEC to a Tonks gas

We analyze shock-wave solutions of the mean-field equations describing delta interacting 1D Bose gas for {\\it arbitrary}, repulsive, interaction strength. We derive a simple expression for the speed of propagation of arbitrarily shaped pulses. We use the number-conserving Bogolubov approach to verify the applicability of mean-field approach to shock wave problems in a 1D Bose-Einstein condensate (BEC). We show that quantum corrections to the dynamics of BEC shocks are likely to be negligible for white shocks. For dark shock waves quantum corrections seem to be negligible until the moment of wave breaking, which is followed by soliton production. We show that quantum corrections to dark-shock-originated solitons can be significant. We point out possible signatures of the BEC-Tonks crossover in a white shock dynamics. Our findings can be directly verified in different experimental setups.

Damski, B

2006-01-01

332

Confinement and quantum anomaly in quasi-1D spinless fermion chains

We consider the field renormalization group (RG) of two coupled one-spatial dimension (1D) spinless fermion chains under intraforward, interforward, interbackscattering and interumklapp interactions until two-loops order. Up to this order, we demonstrate the quantum confinement in the RG flow, where the interband chiral Fermi points reduce to single chiral Fermi points and the renormalized interaction couplings have Luttinger liquid fixed points. We show that this quasi-1D system is equivalently described in terms of one and two-color interactions and address the problem of quantum anomaly, inherent to this system, as a direct consequence of coupling 1+1 free Dirac fields to one and two-color interactions.

Prudêncio, Thiago

2013-01-01

333

Detecting Majorana fermions in quasi-1D topological phases using non-local order parameters

There has been much recent interest in realizing Majorana fermions in solid-state or cold atom systems. A primary goal has been to identify the topological phases which host them and propose routes towards their experimental detection. Such topological phases cannot be distinguished via local order parameters. Instead, we propose non-local string order parameters to distinguish 1D topological phases hosting Majorana zero modes. We also discuss potential cold atom measurements of string order, based on recent experimental developments, as a new and alternative route towards their detection. We further consider N identical chains of interacting fermions and use the group cohomology approach to construct non-local order parameters to distinguish topological phases of this quasi-1D system.

Bahri, Yasaman; Vishwanath, Ashvin

2013-03-01

334

The Dynamic Structure Factor of the 1D Bose Gas near the Tonks-Girardeau Limit

While the 1D Bose gas appears to exhibit superfluid response under certain conditions, it fails the Landau criterion according to the elementary excitation spectrum calculated by Lieb. The apparent riddle is solved by calculating the dynamic structure factor of the Lieb-Liniger 1D Bose gas. A pseudopotential Hamiltonian in the fermionic representation is used to derive a Hartree-Fock operator, which turns out to be well-behaved and local. The Random-Phase approximation for the dynamic structure factor based on this derivation is calculated analytically and is expected to be valid at least up to first order in $1/\\gamma$, where $\\gamma$ is the dimensionless interaction strength of the model. The dynamic structure factor in this approximation clearly indicates a crossover behavior from the non-superfluid Tonks to the superfluid weakly-interacting regime, which should be observable by Bragg scattering in current experiments.

Brand, J; Brand, Joachim; Cherny, Alexander Yu.

2004-01-01

335

B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction.

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells. PMID:24198748

Shin, Jung Hoon; Park, Se-Ho

2013-10-01

336

A finite element solver and energy stable coupling for 3D and 1D fluid models

The paper develops a solver based on conforming finite element method (FEM) for a 3D--1D coupled incompressible flow problem. New coupling conditions are introduced to ensure a suitable bound for the cumulative energy of the model. We study the stability and the accuracy of the discretization method and the performance of some state-of-the-art linear algebraic solvers for such flow configurations. Motivated by the simulation of the flow over inferior vena cava (IVC) filter, we consider the coupling of a 1D fluid model and a 3D fluid model posed in a domain with anisotropic inclusions. The relevance of our approach to realistic cardiovascular simulations is demonstrated by computing a blood flow over a model IVC filter.

Dobroserdova, Tatiana K

2013-01-01

337

Potentiometric, ESI MS and AM1d studies of lasalocid esters silver(I) complexes

Eight lasalocid esters (L) were synthesised and their complex formation with Ag + cations in propylene carbonate was studied by the potentiometric, ESI MS and AM1d semiempirical methods. The stability constants of AgL +, AgL2+ and Ag 2L 2+ complexes were determined indicating the favourable formation of the 1:1 complexes (AgL +). ESI MS spectra of the Lasalocid esters complexes with Ag + cations demonstrated also the formation of the 1:1 complexes. The formation of AgL2+ and Ag 2L 2+ complexes under the ESI MS conditions was not detected. The ?HOF values calculated by the AM1d semiempirical method show that the formation of the 1:1 complexes is favourable and this result is in very good agreement with the experimental data. The structures of AgL +, and Ag 2L 2+ complexes of Las3 and Las7 are visualised and discussed.

Pankiewicz, Rados?aw; Kira, Jaromir; Schroeder, Grzegorz; Ossowski, Tadeusz; Brzezinski, Bogumi?

2006-01-01

338

Homochiral 3D Metal-Organic Frameworks from Chiral 1D Rods: 6 – Way Helical Packing

Energy Technology Data Exchange (ETDEWEB)

The chiral 3D MOFs resulted from the packing of chiral 1D SBBs were studied. It was demonstrated that the final packing pattern is dependent on the dimension of SBB's. In addition, we were able to identify a new plywood-like network from ligand 2H2 exhibiting an unprecedented six-way chiral helical packing motif, which can be added on the list of invariant rod packings.

Shin, Sung M.; Moon, Dohyun; Jeong, Kyung S.; Kim, Jaheon; Thallapally, Praveen K.; Jeong, Nakcheol

2011-07-20

339

Non-generic blow-up solutions for the critical focusing NLS in 1-D

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider the L-2-critical focusing non-linear Schrodinger equation in 1 + 1d. We demonstrate the existence of a large set of initial data close to the ground state soliton resulting in the pseudo-conformal type blow-up behavior. More specifically, we prove a version of a conjecture of Perelman, establishing the existence of a codimension one stable blow-up manifold in the measurable category.

2009-01-01

340

Ultracold Bose Gases in 1D Random Potentials: From Lifshits Glasses to Bose-Einstein Condensates

We study an ultracold Bose gas in the presence of 1D disorder for repulsive inter-atomic interactions, ranging from zero to the Thomas-Fermi regime. We show that for very small interactions, the Bose gas populates a finite number of localized single particle Lifshits states, while for large interactions, it forms a delocalized disordered Bose-Einstein condensate. We discuss the phase diagram and compute the equations of state in various phases.

Lugan, P; Bouyer, P; Aspect, A; Lewenstein, M; Sánchez-Palencia, L; Lugan, Pierre; Cl\\'{e}ment, David; Bouyer, Philippe; Aspect, Alain; Lewenstein, Maciej; Sanchez-Palencia, Laurent

2006-01-01

341

Digital Repository Infrastructure Vision for European Research (DRIVER)

The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme i...

Alle?gre, Vincent; Lehmann, Franc?ois; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal

2012-01-01

342

The supersymmetric solutions and extensions of ungauged matter-coupled N = 1, d = 4 supergravity

International Nuclear Information System (INIS)

We find the most general supersymmetric solutions of ungauged N = 1, d = 4 supergravity coupled to an arbitrary number of vector and chiral supermultiplets, which turn out to be essentially pp-waves and strings. We also introduce magnetic 1-forms and their supersymmetry transformations and 2-forms associated to the isometries of the scalar manifold and their supersymmetry transformations. Only the latter can couple to BPS objects (strings), in agreement with our results.

2008-05-01

343

The supersymmetric solutions and extensions of ungauged matter-coupled N=1,d=4 supergravity

We find the most general supersymmetric solutions of ungauged N=1,d=4 supergravity coupled to an arbitrary number of vector and chiral supermultiplets, which turn out to be essentially pp-waves and strings. We also introduce magnetic 1-forms and their supersymmetry transformations and 2-forms associated to the isometries of the scalar manifold and their supersymmetry transformations. Only the latter can couple to BPS objects (strings), in agreement with our results.

Ortin, Tomas

2008-01-01

344

Chemistry in 1d via DMRG: Benchmarks for small atoms, ions, and molecules

The density matrix renormalization group (DMRG) method, an efficient solver of lattice models in 1d, has been adapted to solve real-space problems. We use DMRG to study the behavior of soft-Coulomb interacting matter, reporting accurate benchmarks for small systems. We compare with Hartree-Fock and the local density approximation, noting similarities and differences with 3d. We study how correlation grows as bonds stretch.

Wagner, Lucas O; Burke, Kieron; White, Steven R

2012-01-01

345

Finite difference approximation of control via the potential in a 1-D Schrodinger equation

Directory of Open Access Journals (Sweden)

Full Text Available We consider the problem of steering given initial data to given terminal data via a time-dependent potential, the control, in a 1-D Schrodinger equation. We determine a condition for existence of a transferring potential within our approximation. Using Maple, we give equations for the control and also examples in which the potential is restricted to be centralized and to be a step potential.

K. Kime

2000-04-01

346

Hawking Radiation from Non-Extremal D1-D5 Black Hole via Anomalies

Digital Repository Infrastructure Vision for European Research (DRIVER)

We take the method of anomaly cancellation for the derivation of Hawking radiation initiated by Robinson and Wilczek, and apply it to the non-extremal five-dimensional D1-D5 black hole in string theory. The fluxes of the electric charge flow and the energy-momentum tensor from the black hole are obtained. They are shown to match exactly with those of the two-dimensional black body radiation at the Hawking temperature.

Shin, Hyeonjoon; Kim, Wontae

2007-01-01

347

Hawking radiation from non-extremal D1-D5 black hole via anomalies

Energy Technology Data Exchange (ETDEWEB)

We take the method of anomaly cancellation for the derivation of Hawking radiation initiated by Robinson and Wilczek, and apply it to the non-extremal five-dimensional D1-D5 black hole in string theory. The fluxes of the electric charge flow and the energy-momentum tensor from the black hole are obtained. They are shown to match exactly with those of the two-dimensional black body radiation at the Hawking temperature.

Shin, Hyeonjoon [Center for Quantum Spacetime, Sogang University, Seoul, 121-742 (Korea, Republic of); Kim, Wontae [Department of Physics and Center for Quantum Spacetime, Sogang University, C.P.O. Box 1142, Seoul 100-611 (Korea, Republic of)

2007-06-15

348

Folding a 2-D powder diffraction image into a 1-D scan: a new procedure

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new procedure aiming at folding a powder diffraction 2-D into a 1-D scan is presented. The technique consists of three steps: tracking the beam centre by means of a Simulated Annealing (SA) of the diffraction rings along the same axis, detector tilt and rotation determination by a Hankel Lanczos Singular Value Decomposition (HLSVD) and intensity integration by an adaptive binning algorithm. The X-ray powder diffraction (XRPD) intensity profile of the standard NIST Si 640c ...

Cervellino, Antonio; Giannini, Cinzia; Guagliardi, Antonietta; Ladisa, Massimo

2006-01-01

349

Local source tomography for Vrancea (Romania) region: minimum 1D model

International Nuclear Information System (INIS)

The Vrancea zone is characterized by a narrow, vertical focal volume of intense and persistent seismicity in the depth range of 60-220 km. The processes associated with the Vrancea earthquakes outline a final stage of continental subduction with plate detachment, still far from being understood. Our main purpose is to perform local earthquake tomography to image crustal structures in Vrancea and adjacent regions as initial reference model in 3 D tomography. The study includes updating of the existing catalogues of seismic parameter data, calculation of a minimum 1D model and correlation with the existing controlled-source data. The model is determined by a trial-and-error process, with internal non-linear (iterative) inversion procedure (program VELEST). The average velocity model parameters are obtained by minimizing the standard deviations of the travel time residuals. The P-wave travel times for 500 well-locatable events are used, merging travel time data recorded by two separate independent seismic networks: the Romanian telemetered network (17 vertical-component S-13 seismometers) and the digital accelerometers network (30 three-component K2 instruments) installed in 1996 within the joint Romanian-German cooperation programme CRC 461. Since the two networks largely overlap geographically, we calculate a common minimum 1D model that guarantees a uniform location quality and uniform phase identification for the two networks. Absolute mislocation errors for the combined networks using the minimum 1D model are calculated using quarry blast data obtained during the VRANCEA99 refraction experiment deployed in 1999 in Romania as a contribution to the CRC 461 programme. The resulted minimum 1D model and station corrections are used to relocate all the considered events and to improve the consistency in the phase identification. The station corrections obtained are correlated with the lateral velocity variations in the surface geology of the region. This paper is a preliminary contribution to the future seismic tomography study in the framework of the CALIXTO'99 project. (authors)

2000-09-21

350

Li-diffusion and lattice relaxation in the 1-d superionic-conductor beta-eucryptite

International Nuclear Information System (INIS)

The 1-d Li+ conductor ?-eucryptite (LiAlSiO4) was studied by quasi-elastic neutron measurements. From the coherent scattering it can be shown that correlations between the Li+ ions are extremely important up to the highest investigated temperatures (T0C). The diffusion of individual ions was studied by incoherent scattering. For the Li+ a jump diffusion along c with mainly a jump-distance of c/3 was confirmed. (Auth.)

1983-12-01

351

Absorption enhancement in 1D Ag/SiO2 metallic-dielectric photonic crystals

Directory of Open Access Journals (Sweden)

Full Text Available The one-dimensional Ag/SiO2 metallic-dielectric photonic crystals (PCs have been prepared. The absorption enhancement effect over the corresponding metal of 1D Ag/SiO2 metallic-dielectric multi-layer structures has been measured. The enhancement effect increases with the number of layers increasing. The origin of this phenomenon and its effect on the transmittance and reflectance have been discussed.

Duanzheng Yao

2009-01-01

352

Quark-Hadron Duality in Spin Structure Functions g1p and g1d

Digital Repository Infrastructure Vision for European Research (DRIVER)

New measurements of the spin structure functions of the proton and deuteron g1p(x,Q2) and g1d(x,Q2) in the nucleon resonance region are compared with extrapolations of target-mass-corrected next-to-leading-order (NLO) QCD fits to higher energy data. Averaged over the entire resonance region (W1.7 GeV2. This global duality appears to result from cancellations among the prominent lo...

Bosted, P. E.; Dharmawardane, K. V.; Dodge, G. E.; Forest, T. A.; Kuhn, S. E.; Al, Y. Prok Et

2006-01-01

353

On the gravitational stability of D1-D5-P black holes

Digital Repository Infrastructure Vision for European Research (DRIVER)

We examine the stability of the nonextremal D1-D5-P black hole solutions. In particular, we look for the appearance of a superradiant instability for the spinning black holes but we find no evidence of such an instability. We compare this situation with that for the smooth soliton geometries, which were recently observed to suffer from an ergoregion instability, and consider the implications for the fuzzball proposal.

Cardoso, Vitor; Dias, Oscar J. C.; Myers, Robert C.

2007-01-01

354

Line shape of the non-thermal 6300 A O/1D/ emission

The two-population model of Schmitt, Abreu and Hays (1981) is used to calculate the line shape of the atomic oxygen metastable state, nonthermal O(1D) 6300 A emission, in order to simulate observations made from a space platform at different zenith angles and altitudes. The Addition theorem, for spherical harmonics of a Legendre polynomial expansion of the nonthermal population distribution function, is used to obtain nonthermal line shapes observed at zenith angles other than the local vertical one.

Schmitt, G. A.; Abreu, V. J.; Hays, P. B.

1982-01-01

355

Prediction of car cabin environment by means of 1D and 3D cabin model

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thermal comfort and also reduction of energy requirements of air-conditioning system in vehicle cabins are currently very intensively investigated and up-to-date issues. The article deals with two approaches of modelling of car cabin environment; the first model was created in simulation language Modelica (typical 1D approach without cabin geometry) and the second one was created in specialized software Theseus-FE (3D approach with cabin geometry). Performance and capabilities of this t...

Fišer J.; Pokorný J.; Jícha M.

2012-01-01

356

Analysis of lumped parameter models for blood flow simulations and their relation with 1D models

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper provides new results of consistence and convergence of the lumped parameters (ODE models) toward one-dimensional (hyperbolic or parabolic) models for blood flow. Indeed, lumped parameter models (exploiting the electric circuit analogy for the circulatory system) are shown to discretize continuous 1D models at first order in space. We derive the complete set of equations useful for the blood flow networks, new schemes for electric circuit analogy, the stability criteria that guarant...

2004-01-01

357

Stability and control of a confined 1D quantum system with time-dependent delta potentials

International Nuclear Information System (INIS)

The evolution problem for a quantum particle confined in a 1D box and interacting with one fixed point through a time-dependent point interaction is considered. Under suitable assumptions of regularity for the time profile of the Hamiltonian, we prove the existence of strict solutions to the corresponding Schroedinger equation. The result is used to discuss the stability and steady-state local controllability of the wavefunction when the strength of the interaction is used as a control parameter.

2011-04-08

358

Zero finite-temperature charge stiffness within the half-filled 1D Hubbard model

Energy Technology Data Exchange (ETDEWEB)

Even though the one-dimensional (1D) Hubbard model is solvable by the Bethe ansatz, at half-filling its finite-temperature T>0 transport properties remain poorly understood. In this paper we combine that solution with symmetry to show that within that prominent T=0 1D insulator the charge stiffness D(T) vanishes for T>0 and finite values of the on-site repulsion U in the thermodynamic limit. This result is exact and clarifies a long-standing open problem. It rules out that at half-filling the model is an ideal conductor in the thermodynamic limit. Whether at finite T and U>0 it is an ideal insulator or a normal resistor remains an open question. That at half-filling the charge stiffness is finite at U=0 and vanishes for U>0 is found to result from a general transition from a conductor to an insulator or resistor occurring at U=U{sub c}=0 for all finite temperatures T>0. (At T=0 such a transition is the quantum metal to Mott–Hubbard-insulator transition.) The interplay of the ?-spin SU(2) symmetry with the hidden U(1) symmetry beyond SO(4) is found to play a central role in the unusual finite-temperature charge transport properties of the 1D half-filled Hubbard model. -- Highlights: •The charge stiffness of the half-filled 1D Hubbard model is evaluated. •Its value is controlled by the model symmetry operator algebras. •We find that there is no charge ballistic transport at finite temperatures T>0. •The hidden U(1) symmetry controls the U=0 phase transition for T>0.

Carmelo, J.M.P., E-mail: carmelo@fisica.uminho.pt [Center and Department of Physics, University of Minho, Campus Gualtar, P-4710-057 Braga (Portugal); Beijing Computational Science Research Center, Beijing 100084 (China); Institut für Theoretische Physik III, Universität Stuttgart, D-70550 Stuttgart (Germany); Gu, Shi-Jian [Beijing Computational Science Research Center, Beijing 100084 (China); Department of Physics and ITP, Chinese University of Hong Kong, Hong Kong (China); Sacramento, P.D. [CFIF, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Beijing Computational Science Research Center, Beijing 100084 (China)

2013-12-15

359

Ground-state energy for 1D (t,U,X)-model at low densities

International Nuclear Information System (INIS)

In describing the properties of quasi-1D materials with a highly-screened interelectronic potential, an attractive hopping term has to be added to the Hubbard Hamiltonian. The effective interaction and the ground-state energy in ladder approximation are analyzed. At low electronic densities, the attractive part of the interaction, initially smaller than the repulsive term, can become more effective, the ground-state energy decreasing below the unperturbed value. (author). 12 refs, 4 figs

1992-01-01

360

Dimensional crossover from 2D to 1D in small-Josephson-junction arrays

International Nuclear Information System (INIS)

Dimensionality effect on the superconductor-insulator transition in small-Josephson-junction arrays has been studied experimentally. We have fabricated 2D arrays with different widths including a 1D array simultaneously on the same substrate and observed a crossover from superconducting to insulating behavior as the array width was reduced. The result indicates that the quantum fluctuations of the superconducting phases are enhanced by the dimensional reduction

2003-05-01

361

1D lattice dynamics of the diffusion limited reaction $A + A \\to A + S Transient behavior

We use a boolean cellular automaton model to describe the diffusion limiteddynamics of the irreversible reaction A+A->A+S on a 1D lattice. We derive a setof equations for the dynamics of the empty interval probabilities from whichexplicit expressions for the particle concentration and the two-pointcorrelation can be obtained. It is shown that the long time dynamics is inagreement with the off-lattice solution. The early time behavior, however,predicts a slower decay of the concentration.

Abad, E; Nicolis, G

2000-01-01

362

A new derivation of Akcasu's 'MLP' equations for 1-D particle transport in stochastic media

International Nuclear Information System (INIS)

This paper presents a new derivation of Akcasu's modified Levermore-Pomraning (MLP) model, which estimates the ensemble-averaged angular flux for particle transport problems in 1-D geometrically random media. The significant new feature of the MLP equations is that, unlike the earlier Levermore-Pomraning (LP) model, the MLP equations are exact for certain classes of problems with scattering. We also show, via asymptotic analyses, that the MLP equations are accurate in the atomic mix and diffusion limits

2008-04-01

363

Microsomal triglyceride transfer protein lipidation and control of CD1d on antigen-presenting cells

Digital Repository Infrastructure Vision for European Research (DRIVER)

Microsomal triglyceride transfer protein (MTP), an endoplasmic reticulum (ER) chaperone that loads lipids onto apolipoprotein B, also regulates CD1d presentation of glycolipid antigens in the liver and intestine. We show MTP RNA and protein in antigen-presenting cells (APCs) by reverse transcription–polymerase chain reaction and by immunoblotting of mouse liver mononuclear cells and mouse and human B cell lines. Functional MTP, demonstrated by specific triglyceride transfer activity, is pre...

2005-01-01

364

Self Configuring Routing and 802.1D Bridging Bridge with automatic hierarchical local MAC addresses.

Digital Repository Infrastructure Vision for European Research (DRIVER)

UCIII offers the first hierarchical routing protocol on layer two using self configured standard local MAC addresses. Makes Ethernet networks scalable without encapsulation. Compatible and self configurable within IEEE 802.1D standard bridges through a combined spanning tree protocol. Simple application of Up/Down routing and Distance Vector principles, enhanced Turn Prohibition mechanisms that allow last turn to destination branch to be permitted. Partner sought: big/small switch manufacturers

Azcorra Salon?a, Arturo

2008-01-01

365

Time-dependent delta-interactions for 1D Schr\\"odinger Hamiltonians

The non autonomous Cauchy problem for time dependent 1D point interactions is considered. The regularity assumptions for the coupling parameter are accurately analyzed and show that the general results for non autonomous linear evolution equations in Banach spaces are far from being optimal. In the mean time, this article shows an unexpected application of paraproduct techniques, initiated by J.M. Bony for nonlinear partial differential equations, to a classical linear problem.

Hmidi, Taoufik; Nier, Francis

2009-01-01

366

1D exciton band and exciton-phonon interaction in a single polymer chain

The excitonic luminescence of an isolated polydiacetylene polymer chain in its monomer matrix is studied by micro-photoluminescence. These chains behave as perfect 1D excitonic systems with the expected 1/sqrt{E} density of states between 5 and 50 K. The temperature dependence of the homogeneous width is quantitatively explained by interaction with longitudinal acoustic phonons of the crystal in the range of temperature explored.

Dubin, F

2002-01-01

367

Insulin stimulation regulates AS160 and TBC1D1 phosphorylation sites in human skeletal muscle

DEFF Research Database (Denmark)

Individuals with obesity and type 2 diabetes (T2D) are typically insulin resistant, exhibiting impaired skeletal muscle glucose uptake. Animal and cell culture experiments have shown that site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 and TBC1D1 is critical for GLUT4 translocation facilitating glucose uptake, but their regulation in human skeletal muscle is not well understood.

Middelbeek, R J W; Chambers, M A

2013-01-01

368

Inverse Problem for the Discrete 1D Schrödinger Operator with Small Periodic Potentials

Consider the discrete 1D Schrödinger operator on ? with an odd 2k periodic potential q. For small potentials we show that the mapping: q? heights of vertical slits on the quasi-momentum domain (similar to the Marchenko-Ostrovski maping for the Hill operator) is a local isomorphism and the isospectral set consists of 2k distinct potentials. Finally, the asymptotics of the spectrum are determined as q?0.

Korotyaev, Evgeny; Kutsenko, Anton

2006-02-01

369

On variational data assimilation for 1D and 2D fluvial hydraulics

Digital Repository Infrastructure Vision for European Research (DRIVER)

We address two problems related to variational data assimilation (VDA) as applied to river hydraulics (1D and 2D shallow water models). First, we seek to estimate accurately some parameters such as the inflow discharge, manning coefficients, the topography and/or the initial state. We develop a method which allow to assimilate lagrangian data (trajectory particles at the surface e.g. extracted from video images). Second, we develop a joint data assimilation - coupling method. We seek to coupl...

Gejadze, Igor; Honnorat, Marc; Le Dimet, Franc?ois-xavier; Monnier, Jerome

2006-01-01

370

Off-shell ''N=1 D=6'' and ''conformal N=2 D=4'' supergravity theories

International Nuclear Information System (INIS)

The superspace torsions constraints are imposed and a solution of the Bianchi identities in terms of superfields and their covariant derivatives is given. The component fields, their supersymmetry transformation are show and a Lagrangian which couples supergravity and a matter multiplet is exhibited. Finally it is shown that after dimensional reduction the N=1 D=6 off-shell supergravity theory yields the N=2 D=4 off-shell conformal supergravity theory. (Author)

1983-01-01

371

The general 1D Schr\\"odinger equation as an exactly solvable problem

We review an exact WKB resolution method for the stationary 1D Schr\\"odinger equation with a general polynomial potential. This contribution covers already published material: we supply a commented summary here, stressing a few aspects which were less highlighted before. As some of our earlier papers needed later corrections, we also recapitulate these here in footnotes in the bibliography. The latter, not meant to be exhaustive, focuses on narrowly relevant works plus some broader ones that do offer more extensive bibliographies.

Voros, A

2004-01-01

372

A Fulling-Kuchment theorem for the 1D harmonic oscillator

We prove that there exists a pair of "non-isospectral" 1D semiclassical Schr\\"odinger operators whose spectra agree modulo h^\\infty. In particular, all their semiclassical trace invariants are the same. Our proof is based on an idea of Fulling-Kuchment and Hadamard's variational formula applied to suitable perturbations of the harmonic oscillator. Keywords: Inverse spectral problems, semiclassical Schr\\"odinger operators, trace invariants, Hadamard's variational formula, harmonic oscillator, Penrose mushroom, Sturm-Liouville theory.

Guillemin, Victor

2011-01-01

373

Wave functions of the super Tonks-Girardeau gas and the trapped 1D hard sphere Bose gas

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent theoretical and experimental results demonstrate a close connection between the super Tonks-Girardeau (sTG) gas and a 1D hard sphere Bose (HSB) gas with hard sphere diameter nearly equal to the 1D scattering length $a_{1D}$ of the sTG gas, a highly excited gas-like state with nodes only at interparticle separations $|x_{j\\ell}|=x_{node}\\approx a_{1D}$. It is shown herein that when the coupling constant $g_B$ in the Lieb-Liniger interaction $g_B\\delta(x_{j\\ell})$ is ne...

Girardeau, M. D.; Astrakharchik, G. E.

2009-01-01

374

Higher secant varieties of P^n × P^m embedded in bi-degree (1,d)

Digital Repository Infrastructure Vision for European Research (DRIVER)

Let $X^{(n,m)}_{(1,d)}$ denote the Segre\\/-Veronese embedding of $\\PP n \\times \\PP m$ via the sections of the sheaf $\\mathcal{O}(1,d)$. We study the dimensions of higher secant varieties of $X^{(n,m)}_{(1,d)}$ and we prove that there is no defective $s^{th}$ secant variety, except possibly for $n$ values of $s$. Moreover when ${m+d \\choose d}$ is a multiple of $(m+n+1)$, the $s^{th}$ secant variety of $X^{(n,m)}_{(1,d)}$ has the expected dimension for every $s$.

Bernardi, Alessandra; Carlini, Enrico; Catalisano, Maria Virgina

2011-01-01

375

Distinct requirements for CD1d intracellular transport for development of V?14 iNKT cells1

Digital Repository Infrastructure Vision for European Research (DRIVER)

The positive selection of V?14 invariant (i)NKT cells in mice requires CD1dmediated antigen presentation by CD4+ CD8+ thymocytes. Maturation of newly selected iNKT cells continues in the periphery also involves CD1d expression. CD1d molecules acquire antigens for presentation in endosomal compartments, to which CD1d molecules have access through an intrinsic CD1d-encoded tyrosine motif and by association with the Class II major histocompatibility complex (MHC) chaperone, invariant chain (Ii)...

Sille?, Fenna C. M.; Boxem, Mike; Sprengers, Dave; Veerapen, Natacha; Besra, Gurdyal; Boes, Marianne

2009-01-01

376

Substrate specificity and effect on GLUT4 translocation of the Rab GTPase-activating protein Tbc1d1.

Insulin stimulation of the trafficking of the glucose transporter GLUT4 to the plasma membrane is controlled in part by the phosphorylation of the Rab GAP (GTPase-activating protein) AS160 (also known as Tbc1d4). Considerable evidence indicates that the phosphorylation of this protein by Akt (protein kinase B) leads to suppression of its GAP activity and results in the elevation of the GTP form of a critical Rab. The present study examines a similar Rab GAP, Tbc1d1, about which very little is known. We found that the Rab specificity of the Tbc1d1 GAP domain is identical with that of AS160. Ectopic expression of Tbc1d1 in 3T3-L1 adipocytes blocked insulin-stimulated GLUT4 translocation to the plasma membrane, whereas a point mutant with an inactive GAP domain had no effect. Insulin treatment led to the phosphorylation of Tbc1d1 on an Akt site that is conserved between Tbc1d1 and AS160. These results show that Tbc1d1 regulates GLUT4 translocation through its GAP activity, and is a likely Akt substrate. An allele of Tbc1d1 in which Arg(125) is replaced by tryptophan has very recently been implicated in susceptibility to obesity by genetic analysis. We found that this form of Tbc1d1 also inhibited GLUT4 translocation and that this effect also required a functional GAP domain. PMID:17274760

Roach, William G; Chavez, Jose A; Mîinea, Cristinel P; Lienhard, Gustav E

2007-04-15

377

A study on cooling efficiency using 1-d analysis code suitable for cooling system of thermoforming

Energy Technology Data Exchange (ETDEWEB)

Thermoforming is one of the most versatile and economical processes available for polymer products, but cycle time and production cost must be continuously reduced in order to improve the competitive power of products. In this study, water spray cooling was simulated to apply to a cooling system instead of compressed air cooling in order to shorten the cycle time and reduce the cost of compressed air used in the cooling process. At first, cooling time using compressed air was predicted in order to check the state of mass production. In the following step, the ratio of removed energy by air cooling or water spray cooling among the total removed energy was found by using 1-D analysis code of the cooling system under the condition of checking the possibility of conversion from 2-D to 1-D problem. The analysis results using water spray cooling show that cycle time can be reduced because of high cooling efficiency of water spray, and cost of production caused by using compressed air can be reduced by decreasing the amount of the used compressed air. The 1-D analysis code can be widely used in the design of a thermoforming cooling system, and parameters of the thermoforming process can be modified based on the recommended data suitable for a cooling system of thermoforming

Li, Zhen Zhe; Heo, Kwang Su; Xuan, Dong Ji; Seol, Seoung Yun [Chonnam National University, Gwangju (Korea, Republic of)

2009-03-15

378

Ultrafast terahertz-field-induced dynamics of superconducting bulk and quasi-1D samples

International Nuclear Information System (INIS)

Within a density-matrix formalism based on the Bardeen–Cooper–Schrieffer (BCS) model and the Bogoliubov–de Gennes equations we provide a description of the dynamics of the non-equilibrium superconducting pairing induced by a terahertz (THz) laser pulse in bulk and quasi-one-dimensional (1D) samples of conventional (BCS-type) superconductors. A cross-over from an adiabatic to a non-adiabatic regime takes place for short and intense THz pulses. In the non-adiabatic regime, the order parameter performs a damped oscillation. We discuss how the parameters of the THz pulse influence the amplitude and the mean value of the oscillation in bulk samples. It is demonstrated that for high intensities the non-adiabatic regime can be reached even for pulses longer than the oscillation period. For the 1D samples we find that the oscillation may attenuate with a different power law. This is analysed by comparing the THz-induced dynamics with the dynamics induced by a sudden switching of the pairing strength, which exhibits essentially the same behaviour. The numerical calculations show that the exponent of the power law depends critically on the density of states in the Debye window and therefore changes in an oscillatory way with the confinement strength. Irregularities in the decay of the oscillation are predicted when the 1D quantum wire is cut short to an elongated zero-dimensional quantum dot structure. (paper)

2013-05-01

379

Renegade homeostatic cytokine responses in T1D: drivers of regulatory/effector T cell imbalance.

Homeostatic cytokines contribute to the balance between regulatory and effector T cells (Tregs and Teffs respectively) and are necessary to maintain peripheral tolerance. These cytokines include IL-2 that supports Treg and IL-7 and IL-15 that drive Teff. In overt settings of lost tolerance (i.e. graft rejection), IL-2 Treg signatures are decreased while IL-7 and IL-15 Teff signatures are often enhanced. Similar cytokine profile imbalances also occur in some autoimmune diseases. In type 1 diabetes (T1D), there are underlying defects in the IL-2 pathway and Teff cytokine blockade can prevent and treat diabetes in NOD mice. In this review, we summarize evidence of IL-2, IL-7 and IL-15 genetic and cellular alterations in T1D patients. We then discuss how the combined effect of these cytokine profiles may together contribute to altered Treg/Teff ratios and functions in T1D. Implications for combination therapies and suggestions for integrated cytokine and Treg/Teff biomarker development are then proposed. PMID:24576418

Gupta, Shipra; Cerosaletti, Karen; Long, S Alice

2014-04-01

380

Neutronic analysis of the 1D and 1E banks reflux detection system

Energy Technology Data Exchange (ETDEWEB)

Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely, the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal {sup 235}U concentration levels to reflux levels remain satisfactory detectable.

Blanchard, A.

1999-12-21

381

Bottomonium studies via {upsilon}(3S) decays. First observation of {upsilon}(1D) states

Energy Technology Data Exchange (ETDEWEB)

The CLEO III experiment has recently accumulated a large statistics sample of 4.73 {center_dot} 10{sup 6} {upsilon}(3S) decays. We present the first evidence for the production of the triplet {upsilon}(1D) states in the four-photon cascade, {upsilon}(3S) {yields} {gamma}{chi}{sub b}(2P), {chi}{sub b}(2P) {yields} {gamma}{upsilon}(1D), {upsilon}(1D) {yields} {gamma}{chi}{sub b}(1P) {yields} {gamma}{upsilon}(1S), followed by the {upsilon}(1S) annihilation to e{sup +}e{sup -} or {mu}{sup +}{mu}{sup -}. We have also analyzed two-photon cascades between the triplet S and triplet P states and report improved measurements of the photon energies and transition rates. We have searched for {upsilon}(3S) {yields} {gamma}{eta}{sub b}(1S) hindered M1 photon transition in inclusive photon spectrum. No evidence for such a transition is found. We set upper limits on the branching ratio, which rule out many previously published phenomenological estimates of the rate for this transition.

Skwarnicki, T

2003-04-01

382

The investigations on the pressure wave propagation along the arterial network and its relationships with vascular physiopathologies can be supported nowadays by numerical simulations. One dimensional (1D) mathematical models, based on systems of two partial differential equations for each arterial segment suitably matched at bifurcations, can be simulated with low computational costs and provide useful insights into the role of wave reflections. Some recent works have indeed moved in this direction. The specific contribution of the present paper is to illustrate a 1D numerical model numerically coupled with a model for the heart action. Typically, the action of the heart on the arterial system is modelled as a boundary condition at the entrance of the aorta. However, the left ventricle (LV) and the vascular network are a strongly coupled single mechanical system. This coupling can be relevant in the numerical description of pressure waves propagation, particularly when dealing with pathological situations. In this work, we propose a simple lumped parameter model for the heart and show how it can be coupled numerically with a 1D model for the arteries. Numerical results actually confirm the relevant impact of the heart-arteries coupling in realistic simulations. PMID:17132614

Formaggia, Luca; Lamponi, Daniele; Tuveri, Massimiliano; Veneziani, Alessandro

2006-10-01

383

Using the D1D5 CFT to Understand Black Holes

In this dissertation, we review work presented in arXiv:0906.2015, arXiv:0907.1663, arXiv:1002.3132, arXiv:1003.2746, and arXiv:1007.2202 on the D1D5 system. We begin with some motivational material for black holes in string theory. In Chapter 2, we review the D1D5 system, including the gravity and CFT descriptions. In Chapter 3, we show how to perturbatively relax the decoupling limit in a general AdS-CFT setting. This allows one to compute the emission out of the AdS/CFT into the asymptotic flat space. In Chapter 4, we apply that formalism to some particular geometries, and exactly reproduce the emission spectrum. These geometries are interpreted as fuzzball microstates of a black hole, and the emission as the microscopic analogue of the Hawking radiation. In Chapter 5, we discuss how to deform the D1D5 CFT off of its orbifold point. In particular, we present full off-shell expressions for first-order corrections to the CFT states. One can see how high-energy states can fragment into many lower-energy state...

Avery, Steven

2010-01-01

384

Energy Technology Data Exchange (ETDEWEB)

The state of art of modelling activities related to integral experimental facilities of advanced passive reactors show to date important open items. The main advantage of using 1D plant codes is the capability of simulating the full interaction between components traditionally correctly modelled (condensers, heat exchangers, pipes and vessels) and other components for which codes are not 100% suitable (pools and containments). Polytechnical University of Catalonia (UPC) and Polytechnical University of Valencia (UPV) cooperated with other European research organizations in the 'Technology Enhancement for Passive Safety Systems' (TEPSS) project, within the European Fourth Framework Programme. It was a task of both Universities to supply analytical support of PANDA tests. The paper deals with the 1D/3D discussion in the framework of modelling activities related to integral passive facilities like PANDA. It starts choosing reference tests among those corresponding to our participation in TEPSS project. The discrepancies observed in a 1D simulation of the selected tests will be shown and analyzed. An evaluation of how the 3D version can lead to a better agreement with data will be included. Disadvantages of 3D codes will be shown too. Combining the use of different codes, and considering analyst criteria, will make possible to establish suitable recommendations from both engineering and scientific point of view. (author)

Batet, Lluis; Reventos, Francesc [Polytechnical Univ. of Catalonia, Barcelona (Spain); Chiva, Sergio; Munoz-Cobo, J.L.

1999-07-01

385

International Nuclear Information System (INIS)

The state of art of modelling activities related to integral experimental facilities of advanced passive reactors show to date important open items. The main advantage of using 1D plant codes is the capability of simulating the full interaction between components traditionally correctly modelled (condensers, heat exchangers, pipes and vessels) and other components for which codes are not 100% suitable (pools and containments). Polytechnical University of Catalonia (UPC) and Polytechnical University of Valencia (UPV) cooperated with other European research organizations in the 'Technology Enhancement for Passive Safety Systems' (TEPSS) project, within the European Fourth Framework Programme. It was a task of both Universities to supply analytical support of PANDA tests. The paper deals with the 1D/3D discussion in the framework of modelling activities related to integral passive facilities like PANDA. It starts choosing reference tests among those corresponding to our participation in TEPSS project. The discrepancies observed in a 1D simulation of the selected tests will be shown and analyzed. An evaluation of how the 3D version can lead to a better agreement with data will be included. Disadvantages of 3D codes will be shown too. Combining the use of different codes, and considering analyst criteria, will make possible to establish suitable recommendations from both engineering and scientific point of view. (author)

1999-04-19

386

1D Metallo-Dielectric Photonic Crystals as Selective Emitters for Thermophotovoltaic Applications

Spectrally selective thermal radiators that are easy to fabricate is a key ingredient in increasing the efficiency of thermophotovoltaic energy converters. 2D and 3D photonic crystals have been proposed as selective emitters with good control over spectral emission and fabricated. Due to their structural complexity, they are difficult to fabricate. 1D photonic crystals have not been analyzed completely for their spectral emission characteristics. Using a method of dyadic Green's function technique and the fluctuation-dissipation theorem, we have analyzed thermal emission from planarly layered periodic media. 1D photonic crystals made of alternate layers of ultra-thin metallic films in-between dielectric layers exhibit selective emission properties ideal for thermophotovoltaic applications with GaSb photovoltaic cells. By varying the thickness of the dielectric layer, the frequency around which the emitters transitions from lower emissivity to higher emissivity can be altered. It is possible to increase this transition frequency to optical frequencies by replacing the metallic film with a high band gap semiconductor like SiC. Preliminary results from experiments on 1D photonic crystals made of alternating layers of tungsten and alumina will be presented.

Narayanaswamy, Arvind; Cybulski, James; Chen, Gang

2004-11-01

387

Avidity-Dependent Programming of Autoreactive T Cells in T1D

Fate determination for autoreactive T cells relies on a series of avidity-dependent interactions during T cell selection, represented by two general types of signals, one based on antigen expression and density during T cell development, and one based on genes that interpret the avidity of TCR interaction to guide developmental outcome. We used proinsulin-specific HLA class II tetramers to purify and determine transcriptional signatures for autoreactive T cells under differential selection in type 1 diabetes (T1D), in which insulin (INS) genotypes consist of protective and susceptible alleles that regulate the level of proinsulin expression in the thymus. Upregulation of steroid nuclear receptor family 4A (NR4A) and early growth response family genes in proinsulin-specific T cells was observed in individuals with susceptible INS-VNTR genotypes, suggesting a mechanism for avidity-dependent fate determination of the T cell repertoire in T1D. The NR4A genes act as translators of TCR signal strength that guide central and peripheral T cell fate decisions through transcriptional modification. We propose that maintenance of an NR4A-guided program in low avidity autoreactive T cells in T1D reflects their prior developmental experience influenced by proinsulin expression, identifying a pathway permissive for autoimmunity.

Durinovic-Bello, Ivana; Gersuk, Vivian H.; Ni, Chester; Wu, Rebecca; Thorpe, Jerill; Jospe, Nicholas; Sanda, Srinath; Greenbaum, Carla J.; Nepom, Gerald T.

2014-01-01

388

Secure information embedding into 1D biomedical signals based on SPIHT.

This paper proposes an encoding system for 1D biomedical signals that allows embedding metadata and provides security and privacy. The design is based on the analysis of requirements for secure and efficient storage, transmission and access to medical tests in e-health environment. This approach uses the 1D SPIHT algorithm to compress 1D biomedical signals with clinical quality, metadata embedding in the compressed domain to avoid extra distortion, digital signature to implement security and attribute-level encryption to support Role-Based Access Control. The implementation has been extensively tested using standard electrocardiogram and electroencephalogram databases (MIT-BIH Arrhythmia, MIT-BIH Compression and SCCN-EEG), demonstrating high embedding capacity (e.g. 3 KB in resting ECGs, 200 KB in stress tests, 30 MB in ambulatory ECGs), short delays (2-3.3s in real-time transmission) and compression of the signal (by ?3 in real-time transmission, by ?5 in offline operation) despite of the embedding of security elements and metadata to enable e-health services. PMID:23707304

Rubio, Oscar J; Alesanco, Alvaro; García, José

2013-08-01

389

Characterizing CEACAM5 interaction with CD8? and CD1d in intestinal homeostasis.

Normal intestinal epithelial cells (IECs) could act as non-professional antigen-presenting cells, selectively activating CD8(+)-suppressor T cells. An epithelial cell surface glycoprotein, gp180, recognized by monoclonal antibodies B9 and L12 was determined to be critical in this process. Purification and sequence analysis of mAb B9 reactive material revealed amino-acid sequence homology with CEACAM5. We demonstrate that CEACAM5 has properties attributed to gp180, such as CD8? binding and activation of CD8-associated Lck. CEACAM5 is the only CEACAM member interacting with CD1d through the B3 domain. Its N domain (recognized by B9) is required for CD8? binding. Removal of the N-domain glycosylated residues reduces B9 recognition, CD8? binding affinity, and activation of LcK. Therefore, conformational changes in CEACAM5 glycosylation site are critical for its interaction with CD8?. CEACAM5-activated CD8(+) T cells acquire the ability to suppress the proliferation of CD4(+) T cells in vitro in the presence of interleukin (IL)-15 or IL-7. We provide new insights into the role of CEACAM5 and define its specific immunoregulatory properties among the CEACAMs expressed on IECs. We suggest that unique set of interactions between CEACAM5, CD1d, and CD8 render CD1d more class I-like molecule, facilitating antigen presentation and activation of CD8(+)-suppressor regulatory T cells. PMID:24104458

Roda, G; Jianyu, X; Park, M S; DeMarte, L; Hovhannisyan, Z; Couri, R; Stanners, C P; Yeretssian, G; Mayer, L

2014-05-01

390

A study on cooling efficiency using 1-d analysis code suitable for cooling system of thermoforming

International Nuclear Information System (INIS)

Thermoforming is one of the most versatile and economical processes available for polymer products, but cycle time and production cost must be continuously reduced in order to improve the competitive power of products. In this study, water spray cooling was simulated to apply to a cooling system instead of compressed air cooling in order to shorten the cycle time and reduce the cost of compressed air used in the cooling process. At first, cooling time using compressed air was predicted in order to check the state of mass production. In the following step, the ratio of removed energy by air cooling or water spray cooling among the total removed energy was found by using 1-D analysis code of the cooling system under the condition of checking the possibility of conversion from 2-D to 1-D problem. The analysis results using water spray cooling show that cycle time can be reduced because of high cooling efficiency of water spray, and cost of production caused by using compressed air can be reduced by decreasing the amount of the used compressed air. The 1-D analysis code can be widely used in the design of a thermoforming cooling system, and parameters of the thermoforming process can be modified based on the recommended data suitable for a cooling system of thermoforming

2009-03-01

391

Effect of Stress Distribution on 1-D Motion of Radiation Defects

International Nuclear Information System (INIS)

Irradiation induced mechanical property degradation of materials has been studied from several decades ago, but the mechanism is still in controversy. Two mechanisms have been proposed. One is the dispersed barrier hardening mechanism. This explains defect clusters as barriers to the dislocation motion. And the other is the cascade induced source hardening mechanism, which places emphasis on a role of defects as Cottrell atmosphere to dislocation motions. However, the above mechanisms can be applied to only a part of experimental results. Any model has not given a solution to 1-D motion of defect clusters of size over 2 nm. 1-D motion of defects clusters has been observed by many researchers. At first, Kroupa et al. proposed a conservative climb of dislocation loops by pipe diffusion. Kiritani tried to explain the driving force of motion with strain field. Some MD simulation results showed a kind of crowdion motion into close packed direction in a crystal. But large clusters of more than a few hundred SIAs showed significantly reduced mobility. To know the effect of 1-D motion on radiation damage, it is important to clarify driving force of the motion. In this study, we tried to link an observation of the motion of loop to a stress field around loops calculated with the Peach-Koehler equation

2006-11-02

392

Effect of Stress Distribution on 1-D Motion of Radiation Defects

Energy Technology Data Exchange (ETDEWEB)

Irradiation induced mechanical property degradation of materials has been studied from several decades ago, but the mechanism is still in controversy. Two mechanisms have been proposed. One is the dispersed barrier hardening mechanism. This explains defect clusters as barriers to the dislocation motion. And the other is the cascade induced source hardening mechanism, which places emphasis on a role of defects as Cottrell atmosphere to dislocation motions. However, the above mechanisms can be applied to only a part of experimental results. Any model has not given a solution to 1-D motion of defect clusters of size over 2 nm. 1-D motion of defects clusters has been observed by many researchers. At first, Kroupa et al. proposed a conservative climb of dislocation loops by pipe diffusion. Kiritani tried to explain the driving force of motion with strain field. Some MD simulation results showed a kind of crowdion motion into close packed direction in a crystal. But large clusters of more than a few hundred SIAs showed significantly reduced mobility. To know the effect of 1-D motion on radiation damage, it is important to clarify driving force of the motion. In this study, we tried to link an observation of the motion of loop to a stress field around loops calculated with the Peach-Koehler equation.

Kwon, Sang Chul; Kim, Whung Whoe [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Moon, Won Jin; Kim, Young Min [Korea Basic Science Institute, Taejon (Korea, Republic of)

2006-07-01

393

Avidity-Dependent Programming of Autoreactive T Cells in T1D.

Fate determination for autoreactive T cells relies on a series of avidity-dependent interactions during T cell selection, represented by two general types of signals, one based on antigen expression and density during T cell development, and one based on genes that interpret the avidity of TCR interaction to guide developmental outcome. We used proinsulin-specific HLA class II tetramers to purify and determine transcriptional signatures for autoreactive T cells under differential selection in type 1 diabetes (T1D), in which insulin (INS) genotypes consist of protective and susceptible alleles that regulate the level of proinsulin expression in the thymus. Upregulation of steroid nuclear receptor family 4A (NR4A) and early growth response family genes in proinsulin-specific T cells was observed in individuals with susceptible INS-VNTR genotypes, suggesting a mechanism for avidity-dependent fate determination of the T cell repertoire in T1D. The NR4A genes act as translators of TCR signal strength that guide central and peripheral T cell fate decisions through transcriptional modification. We propose that maintenance of an NR4A-guided program in low avidity autoreactive T cells in T1D reflects their prior developmental experience influenced by proinsulin expression, identifying a pathway permissive for autoimmunity. PMID:24844227

Durinovic-Belló, Ivana; Gersuk, Vivian H; Ni, Chester; Wu, Rebecca; Thorpe, Jerill; Jospe, Nicholas; Sanda, Srinath; Greenbaum, Carla J; Nepom, Gerald T

2014-01-01

394

Three novel Cd(II)/Zn(II) compounds, [Cd 2(poda) 2(phen) 3(H 2O)] n· nEtOH·3 nH 2O (1), [Zn(poda) 2(bpy)(H 2O)] n(2) and [Zn(Hpoda) 2(bpy)] (3) (H 2poda = 1,2-phenylenediacetic acid, phen = 1,10-phenanthroline, bpy = 2,2'-bipyridyl), have been synthesized and characterized by IR, TG, fluorescent spectrum and single-crystal X-ray diffraction techniques. In 1, poda 2- anions link the adjacent Cd(II) centers to generate a 1D zigzag chain. Furthermore, an unprecedented four-footed "8-shaped" mixed water-ethanol (H 2O) 6(C 2H 5OH) 2 cluster connects four double chains based on 1D zigzag chain into 3D supramolecular architecture. By bis(chelate-monodentate) fashion of poda 2- ligand, compound 2 exhibits 1D zigzag chains, which forming a dense zipper-like 2D structure via strong ?-? stacking interactions. Differed from 1 and 2, compound 3 has a mononuclear motif, and displays a 3D 6-connected ?-Po net hydrogen-bonded topology. The structure-related solid-state fluorescence spectra of compounds 1 and 2 have been determined.

Yang, Fang; Ren, Yixia; Li, Dongsheng; Fu, Feng; Qi, Guangcai; Wang, Yaoyu

2008-12-01

395

Position error in profiles retrieved from MIPAS observations with a 1-D algorithm

Directory of Open Access Journals (Sweden)

Full Text Available The information load (IL analysis, first introduced for the two-dimensional approach (Carlotti and Magnani, 2009, is applied to the inversion of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding observations operated with a 1-dimensional (1-D retrieval algorithm. The IL distribution of MIPAS spectra is shown to be often asymmetrical with respect to the tangent points of the observations and permits us to define the preferential latitude where the profiles retrieved with a 1-D algorithm should be geo-located. Therefore, defining the geo-location of the retrieved profile by means of the tangent points leads to a "position error". We assess the amplitude of the position error for some of the MIPAS main products and we show that the IL analysis can also be used as a tool for the selection of spectral intervals that, when analyzed, minimize the position error of the retrieved profile. When the temperature (*T* profiles are used for the retrieval of volume mixing ratio (VMR of atmospheric constituents, the *T*-position error (of the order of 1.5 degrees of latitude induces a VMR error that is directly connected with the horizontal *T* gradients. Temperature profiles can be externally-provided or determined in a previous step of the retrieval process. In the first case, the IL analysis shows that a meaningful fraction (often exceeding 50% of the VMR error deriving from the 1-D approximation is to be attributed to the mismatch between the position assigned to the external *T* profile and the positions where *T* is required by the analyzed observations. In the second case the retrieved *T* values suffer by an error of 1.5–2 K due to neglecting the horizontal variability of *T*; however the error induced on VMRs is of minor concern because of the generally small mismatch between the IL distribution of the observations analyzed to retrieve *T* and those analyzed to retrieve the VMR target. An estimate of the contribution of the *T*-position error to the error budget is provided for MIPAS main products. This study shows that the information load analysis can be successfully exploited in a 1-D context that makes the assumption of horizontal homogeneity of the analyzed portion of atmosphere. The analysis that we propose can be extended to the 1-D inversion of other limb-sounding experiments.

M. Carlotti

2013-02-01

396

Position error in profiles retrieved from MIPAS observations with a 1-D algorithm

Directory of Open Access Journals (Sweden)

Full Text Available The information load (IL analysis, first introduced for the two-dimensional approach (Carlotti and Magnani, 2009, is applied to the inversion of MIPAS observations operated with a 1-dimensional (1-D retrieval algorithm. The IL distribution of MIPAS spectra is shown to be often asymmetrical with respect to the tangent points of the observations and permits to identify the preferential latitude where the profiles retrieved with a 1-D algorithm should be geo-located. Therefore a position error is made when the tangent points of the observations are used to assign the geo-location of the retrieved profile. We assess the amplitude of the position error for some of the MIPAS main targets and we show that the IL analysis can also be used as a tool for the selection of observations that, when analyzed, minimize the position error of the retrieved profile. When the temperature (*T* profiles are used for the retrieval of volume mixing ratio (VMR of atmospheric constituents, the *T* position error (of the order of 1.5 degrees of latitude induces a VMR error that is directly connected with the horizontal *T* gradients. Temperature profiles can be externally-provided or determined in a previous step of the retrieval process. In the first case, the IL analysis shows that a meaningful fraction (often exceeding 50% of the VMR error deriving from the 1-D approximation is to be attributed to the mismatch between the position assigned to the external *T* profile and the positions where *T* is required by the analyzed observations. In the second case the retrieved *T* values suffer by an error of 1.5–2 K due to neglecting the horizontal variability of *T*; however the error induced on VMRs is of minor entity because of the generally small mismatch between the IL distribution of the observations analyzed to retrieve *T* and those analyzed to retrieve the VMR target. An estimate of the contribution of the *T*-position error to the error budget is provided for MIPAS main targets. This study shows that the information load analysis can be successfully exploited in a 1-D context that makes the assumption of horizontal homogeneity of the analyzed portion of atmosphere. The analysis that we propose can be extended to the 1-D inversion of other limb-sounding experiments.

M. Carlotti

2012-09-01

397

Position error in profiles retrieved from MIPAS observations with a 1-D algorithm

The information load (IL) analysis, first introduced for the two-dimensional approach (Carlotti and Magnani, 2009), is applied to the inversion of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) observations operated with a 1-dimensional (1-D) retrieval algorithm. The IL distribution of MIPAS spectra is shown to be often asymmetrical with respect to the tangent points of the observations and permits us to define the preferential latitude where the profiles retrieved with a 1-D algorithm should be geo-located. Therefore, defining the geo-location of the retrieved profile by means of the tangent points leads to a "position error". We assess the amplitude of the position error for some of the MIPAS main products and we show that the IL analysis can also be used as a tool for the selection of spectral intervals that, when analyzed, minimize the position error of the retrieved profile. When the temperature (T) profiles are used for the retrieval of volume mixing ratio (VMR) of atmospheric constituents, the T-position error (of the order of 1.5 degrees of latitude) induces a VMR error that is directly connected with the horizontal T gradients. Temperature profiles can be externally-provided or determined in a previous step of the retrieval process. In the first case, the IL analysis shows that a meaningful fraction (often exceeding 50%) of the VMR error deriving from the 1-D approximation is to be attributed to the mismatch between the position assigned to the external T profile and the positions where T is required by the analyzed observations. In the second case the retrieved T values suffer by an error of 1.5-2 K due to neglecting the horizontal variability of T; however the error induced on VMRs is of minor concern because of the generally small mismatch between the IL distribution of the observations analyzed to retrieve T and those analyzed to retrieve the VMR target. An estimate of the contribution of the T-position error to the error budget is provided for MIPAS main products. This study shows that the information load analysis can be successfully exploited in a 1-D context that makes the assumption of horizontal homogeneity of the analyzed portion of atmosphere. The analysis that we propose can be extended to the 1-D inversion of other limb-sounding experiments.

Carlotti, M.; Arnone, E.; Castelli, E.; Dinelli, B. M.; Papandrea, E.

2013-02-01

398

Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

Energy Technology Data Exchange (ETDEWEB)

Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.

K.R. Maskaly

2005-06-01

399

The nuclear matrix protein C1D is an activator of the DNA-dependent protein kinase (DNA-PK), which is essential for the repair of DNA double-strand breaks (DSBs) and V(D)J recombination. C1D is phosphorylated very efficiently by DNA-PK, and its mRNA and protein levels are induced upon gamma-irradiation, suggesting that C1D may play a role in repair of DSBs in vivo. In an attempt to identify the biological function of C1D, we have employed the yeast two-hybrid system and found that C1D interacts specifically with Translin-associated factor X, TRAX. Although the biological function of TRAX remains unknown, its bipartite nuclear targeting sequences suggest a role for TRAX in the movement of associated proteins, including Translin, into the nucleus. We show that C1D and TRAX interact specifically in both yeast and mammalian cells. Interestingly, however, interaction of these two proteins in mammalian cells only occur following gamma-irradiation, raising the possibility of involvement of TRAX in DNA double-strand break repair and providing evidence for biological functions of the nuclear matrix protein C1D and TRAX. Moreover, we show, using fluorescently tagged proteins, that the relative expression levels of TRAX and Translin affect their subcellular localization. These results suggest that one role for C1D may be to regulate TRAX/Translin complex formation. PMID:11801738

Erdemir, Tuba; Bilican, Bilada; Oncel, Dilhan; Goding, Colin R; Yavuzer, Ugur

2002-01-01

400

Alterations in the formation of brain networks are associated with several neurodevelopmental disorders. Mutations in TBC1 domain family member 24 (TBC1D24) are responsible for syndromes that combine cortical malformations, intellectual disability, and epilepsy, but the function of TBC1D24 in the brain remains unknown. We report here that in utero TBC1D24 knockdown in the rat developing neocortex affects the multipolar-bipolar transition of neurons leading to delayed radial migration. Furthermore, we find that TBC1D24-knockdown neurons display an abnormal maturation and retain immature morphofunctional properties. TBC1D24 interacts with ADP ribosylation factor (ARF)6, a small GTPase crucial for membrane trafficking. We show that in vivo, overexpression of the dominant-negative form of ARF6 rescues the neuronal migration and dendritic outgrowth defects induced by TBC1D24 knockdown, suggesting that TBC1D24 prevents ARF6 activation. Overall, our findings demonstrate an essential role of TBC1D24 in neuronal migration and maturation and highlight the physiological relevance of the ARF6-dependent membrane-trafficking pathway in brain development. PMID:24469796

Falace, Antonio; Buhler, Emmanuelle; Fadda, Manuela; Watrin, Françoise; Lippiello, Pellegrino; Pallesi-Pocachard, Emilie; Baldelli, Pietro; Benfenati, Fabio; Zara, Federico; Represa, Alfonso; Fassio, Anna; Cardoso, Carlos

2014-02-11

401

The Rab-GTPase activating protein TBC1D1 is a paralog of AS160/TBC1D4. AS160/TBC1D4, a downstream effector of Akt, has been shown to play a central role in beta-cell function and survival. The two proteins have overlapping function in insulin signalling in muscle cells. However, the expression and the potential role of TBC1D1 in beta-cells remain unknown. Therefore, the aim of this study is to investigate whether TBC1D1 is expressed in beta-cells and whether it plays, as AS160/TBC1D4, a role in beta-cell function and survival. Using human and rat beta-cells, this study shows for the first time that TBC1D1 is expressed and phosphorylated in response to glucose in these cells. Knockdown of TBC1D1 in beta-cells resulted in increased basal and glucose-stimulated insulin release, decreased proliferation but no change in apoptosis. PMID:24239544

Rütti, Sabine; Arous, Caroline; Nica, Alexandra C; Kanzaki, Makoto; Halban, Philippe A; Bouzakri, Karim

2014-01-01

402

The paper is devoted to optimization of quasi-normal eigenvalues of a spectral problem associated with a 1-D wave equation in an inhomogeneous medium. The wave equation is equipped with a radiation boundary condition, and so the set of quasi-normal eigenvalues lies in $\\C_+$. The problem is to design for a given $\\alpha \\in \\R$ the structure of the inhomogeneous medium such that it generates a quasi-normal eigenvalue on the line $\\alpha + \\i \\R$ with a minimal possible imaginary part. We consider the problem for three admissible families of structures. Two of these families have a natural mechanical interpretation as classes of Krein strings with total mass and static moment constraints. For these two classes we find optimal quasi-normal eigenvalues explicitly. The third class of admissible structures is connected with the problem of optimal design for photonic crystals. For this class, the paper gives a wider statement of the optimization problem, proves existence of optimal structures, and study their prope...

Karabash, Illya M

2011-01-01

403

A PIC simulation study on the evolution of the real and imaginary frequencies of 1D plasma waves

We use electrostatic PIC simulations to study the evolution of both the real and complex frequency of 1D plasma waves. We are considering especially the linear regime where the asymptotic damping rate is much bigger than the bounce frequency. In this regime the waves are typically very small and below the thermal noise. These waves can be studied using a subtraction technique where two simulations where identical random number generation seeds are carried out. In the first, a small amplitude wave is excited. In the second simulation no wave is excited. The results from each simulation are subtracted providing a clean linear wave that can be studied. As previously predicted, the damping is divided in two stages, an initial transient and an asymptotic decay (Landau's formula). The time-dependent resonant width measured in the simulations is compared with the theoretical prediction. In typical ICF plasmas nld^3 <˜10^3. Therefore, the number of resonant electrons can be small for linear waves. We will consider the effects of small numbers of resonant particles and their consequences of the observed damping.

Grismayer, Thomas; Fahlen, Jay; Winjum, Benjamin; Tsung, Frank; Morales, George; Mori, Warren

2009-11-01

404

A 2D/1D coupling neutron transport method based on the matrix MOC and NEM methods

Energy Technology Data Exchange (ETDEWEB)

A new 2D/1D coupling method based on the matrix MOC method (MMOC) and nodal expansion method (NEM) is proposed for solving the three-dimensional heterogeneous neutron transport problem. The MMOC method, used for radial two-dimensional calculation, constructs a response matrix between source and flux with only one sweep and then solves the linear system by using the restarted GMRES algorithm instead of the traditional trajectory sweeping process during within-group iteration for angular flux update. Long characteristics are generated by using the customization of commercial software AutoCAD. A one-dimensional diffusion calculation is carried out in the axial direction by employing the NEM method. The 2D and ID solutions are coupled through the transverse leakage items. The 3D CMFD method is used to ensure the global neutron balance and adjust the different convergence properties of the radial and axial solvers. A computational code is developed based on these theories. Two benchmarks are calculated to verify the coupling method and the code. It is observed that the corresponding numerical results agree well with references, which indicates that the new method is capable of solving the 3D heterogeneous neutron transport problem directly. (authors)

Zhang, H.; Zheng, Y.; Wu, H.; Cao, L. [School of Nuclear Science and Technology, Xi' an Jiaotong University, No. 28, Xianning West Road, Xi' an, Shaanxi 710049 (China)

2013-07-01

405

Exact Ground States for Quasi 1D Systems with Hubbard Interaction

Directory of Open Access Journals (Sweden)

Full Text Available Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties. Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties. Using a positive semidefinite operator technique we deduced exact ground states for a modified diamond chain described by a non-integrable Hubbard model with on-site repulsion. Our results are valid for arbitrary length of the chain and strength of the Hubbard interaction. For the analyzed parameter space region of the quasi 1D chain structure we found that two flat bands are present in the bare band structure of the system, both for zero and for a fixed value of magnetic field. We obtained ground states of nonmagnetic and ferromagnetic insulator type and studied their physical properties.

Zs. Gulácsi

2012-03-01