WorldWideScience
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Programming for seismogram 1-D generation, considering the attenuation and dispersing effects; Programa para gerar sismograma 1-D, considerando os efeitos da atenuacao e dispersao  

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

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Generating synthetic seismogram envelopes along the MASE array for a vertical dependent heterogeneous model  

Science.gov (United States)

Coda waves are due to redistribution of energy in a heterogeneous medium. In this study, we propose a multilayer model of the crust to generate synthetic envelopes for local earthquakes along the Pacific trench of Mexico. Our model consists in an heterogeneous crust with different layers of concentrations of scatterers overlying an homogeneous layer representing the absorbing mantle. We assume that the concentration of scatterers is largest near the surface (MLTWA estimates of intrinsic- and scattering-attenuation obtained in a uniform half-space. Geophysical Journal International, 182: 949-955. Fehler, M., Hoshiba, M., Sato, H., and Obara, K. (1992). Separation of Scattering and intrinsic attenuation for the Kanto-Tokai Region, Japan, using measurements of S-wave energy versus hypocentral distance, Geophys, J. Int., 108, 787-800. Yoshimoto, K. (2000). Monte Carlo simulation of seismogram envelopes in scattering media. J. Geophys. Res. 105, 6153-6161.

Dominguez Ramirez, L. A.; Davis, P. M.

2010-12-01

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An Interactive Program on Digitizing Historical Seismograms  

Science.gov (United States)

Retrieving information from historical seismograms is of great importance since they are considered the unique sources that provide quantitative information of historical earthquakes. Modern techniques of seismology require digital forms of seismograms that are essentially a sequence of time-amplitude pairs. However, the historical seismograms, after scanned into computers, are two dimensional arrays. Each element of the arrays contains the grayscale value or RGB value of the corresponding pixel. The problem of digitizing historical seismograms, referred to as converting historical seismograms to digital seismograms, can be formulated as an inverse problem that generating sequences of time-amplitude pairs from a two dimension arrays. This problem has infinite solutions. The algorithm for automatic digitization of historical seismogram presented considers several features of seismograms, including continuity, smoothness of the seismic traces as the prior information, and assumes that the amplitude is a single-valued function of time. An interactive program based on the algorithm is also presented. The program is developed using Matlab GUI and has both automatic and manual modality digitization. Users can easily switch between them, and try different combinations to get the optimal results. Several examples are given to illustrate the results of digitizing seismograms using the program, including a photographic record and a wide-angle reflection/refraction seismogram. Digitized result of the program (redrawn using Golden Software Surfer for high resolution image). (a) shows the result of automatic digitization, and (b) is the result after manual correction.

Xu, Y.; Xu, T.

2013-12-01

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A technique for improving pseudo-synthetic seismograms generated from neutron logs in gas-saturated clastic rocks  

International Nuclear Information System (INIS)

In clastic and carbonate rock sequences, the neutron and sonic log curves usually deflect in a similar fashion. Moreover, in some cases the two curves can be overlain and they generally appear to mimic each other, with variations between them only in the amplitudes of the two curves. This descriptive correlation is the basis of direct cross-plot techniques used to convert a neutron log into a pseudo-sonic log, which can then be combined with a density log to create a pseudo-synthetic seismogram. Unfortunately, the seismograms produced in this way may not match the standard synthetic seismograms produced from the sonic and density logs if the ‘gas effect’ is not taken into account. In order to correct for the gas effect, the inter-log correlations between the compensated neutron log (CNL) and the borehole-compensated (BHC) sonic log curves from a well in Taiwan were carefully examined. Then, we developed a technique for transforming the CNL log into a pseudo-BHC log by splicing together several continuous sandstone intervals in which the gas effect could be identified from the scattered data on the cross-plot of neutron porosity versus sonic interval transit time. Based upon our results, application of the new composite transform method yields a pseudo-synthetic seismogram that better matches the standard synthetic seismogram (made from the sonic and density logs) according to frequency, amplitude and polarity. This gas correction technique may be particularly usefion technique may be particularly useful in oil and gas exploratory and development areas where neutron logs are more prevalent than sonic logs or where sonic logs are scarce. (paper)

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A constant stress-drop model for producing broadband synthetic seismograms: Comparison with the next generation attenuation relations  

Science.gov (United States)

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

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Method for rapid high-frequency seismogram calculation  

Science.gov (United States)

We present a method for rapid, high-frequency seismogram calculation that makes use of an algorithm to automatically generate an exhaustive set of seismic phases with an appreciable amplitude on the seismogram. The method uses a hierarchical order of ray and seismic-phase generation, taking into account some existing constraints for ray paths and some physical constraints. To compute synthetic seismograms, the COMRAD code (from the Italian: "COdice Multifase per il RAy-tracing Dinamico") uses as core a dynamic ray-tracing code. To validate the code, we have computed in a layered medium synthetic seismograms using both COMRAD and a code that computes the complete wave field by the discrete wave number method. The seismograms are compared according to a time-frequency misfit criteria based on the continuous wavelet transform of the signals. Although the number of phases is considerably reduced by the selection criteria, the results show that the loss in amplitude on the whole seismogram is negligible. Moreover, the time for the computing of the synthetics using the COMRAD code (truncating the ray series at the 10th generation) is 3-4-fold less than that needed for the AXITRA code (up to a frequency of 25 Hz).

Stabile, Tony Alfredo; De Matteis, Raffaella; Zollo, Aldo

2009-02-01

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Synthetic seismogram web service and Python tools  

Science.gov (United States)

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

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Finite-difference synthetic seismograms for SH waves  

Science.gov (United States)

The research performed under this contract, during the period 12 January 1983 through 11 January 1984, can be divided into two major topics: finite-difference synthetic seismograms for SH waves; and array analysis of the ground motions from the 1971 San Fernando Earthquake. In Section 2, the accuracy and ease of application of the finite-difference method for generating synthetic seismograms of SH wave propagation in cylindrically symmetric media is discussed. The finite-difference method was the advantage that arbitrary density and velocity field in the medium may be specified. A point source is generated by a simple transformation of a line source. The accuracy of the finite-difference seismograms in flat layered media is confirmed by comparison with the Cagniard De-Hoop method. The finite-difference seismograms also agree with a previously untried dipping-layer Cagniard method. An earthquake radiation pattern is approximated by introducing a near-field which has permanent displacement near the source.

Vidale, J.; Helmberger, D. V.; Clayton, R.

1984-08-01

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Global synthetic seismograms using a 2-D finite-difference method  

Science.gov (United States)

Two-dimensional (2-D) finite-difference (FD) synthetics, which fill the gap between fast 1-D analytic synthetics and time-consuming full 3-D synthetics in our ability to model seismograms, have been used in many studies. We address several issues involving 2-D FD methods in generating global synthetic seismograms. These include: (1) interfacing point source excitation for earthquakes with 2-D FD methods; (2) out-of-plane spreading corrections and (3) reducing the spherical Earth to the flattened models. The first issue is tackled using two methods, a `transparent source box' approach and a moment tensor excitation approach, where each has its own advantages. Moreover, our `source box' excitation does not have the late-time drift problem that occurred in previous studies. The out-of-plane geometric spreading correction is accounted for by estimating the ray parameter and applying a post-simulation filter to 2-D synthetics. Finally, parameters of the Earth-flattening transformation are discussed and validated. The effectiveness of this method is demonstrated by comparing our synthetics with frequency-wavenumber summation, normal-mode and 3-D spectral-element synthetics.

Li, Dunzhu; Helmberger, Don; Clayton, Robert W.; Sun, Daoyuan

2014-05-01

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Holographic memory system based on projection recording of computer-generated 1D Fourier holograms.  

Science.gov (United States)

Utilization of computer generation of holographic structures significantly simplifies the optical scheme that is used to record the microholograms in a holographic memory record system. Also digital holographic synthesis allows to account the nonlinear errors of the record system to improve the microholograms quality. The multiplexed record of holograms is a widespread technique to increase the data record density. In this article we represent the holographic memory system based on digital synthesis of amplitude one-dimensional (1D) Fourier transform holograms and the multiplexed record of these holograms onto the holographic carrier using optical projection scheme. 1D Fourier transform holograms are very sensitive to orientation of the anamorphic optical element (cylindrical lens) that is required for encoded data object reconstruction. The multiplex record of several holograms with different orientation in an optical projection scheme allowed reconstruction of the data object from each hologram by rotating the cylindrical lens on the corresponding angle. Also, we discuss two optical schemes for the recorded holograms readout: a full-page readout system and line-by-line readout system. We consider the benefits of both systems and present the results of experimental modeling of 1D Fourier holograms nonmultiplex and multiplex record and reconstruction. PMID:25322249

Betin, A Yu; Bobrinev, V I; Donchenko, S S; Odinokov, S B; Evtikhiev, N N; Starikov, R S; Starikov, S N; Zlokazov, E Yu

2014-10-01

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Seismogram Construction to Fit the Recorded B032593c Earthquake, Japan on Observation Station Bfo, Germany  

Directory of Open Access Journals (Sweden)

Full Text Available In this research the model of earth layers between earthquake's epicenter in Hokkaido Japan and observation station in Black Forest of Observatory (BFO, Germany is investigated. The earth model is 1-D that represents the average speed model. The earth model is obtained by seismogram comparison between data and synthetic seismogram in time domain and three components simultaneously. Synthetic Seismogram is calculated with the Green's function of the Earth by MINor Integration (GEMINI program, where program's input is initially the earth model IASPEI91, PREMAN and also the Centroid Moment Tensor (CMT solution of the earthquake. A Butterworth low-pass filter with corner frequency of 20 mHz is imposed to measured and synthetic seismogram. On seismogram comparison we can find unsystematic discrepancies, covering the travel time and waveform of all wave phases, namely on P, S, SS wave and surface wave of Rayleigh and Love. Solution to the above mentioned discrepancies needs correction to the earth structure, that covering the change of earth crust thickness, the gradient of ?h and value of zero order coefficient in ?h and ?v in upper mantle, to get the fitting on the surface wave of Love and Rayleigh. Further correction to accomplish the discrepancies on body waves is conducted on layers beneath upper mantle down to depth of 630 km, where a little change at speed model of P and S wave is carried out. The number of oscillation amount especially on Love wave is influenced by earth crust depth earth. Good fitting is obtained at phase and amplitude of Love wave, but also at amplitude of some body wave too. This effect is not yet been exploited for the determination of moment tensor.

Bagus Jaya Santosa

2005-04-01

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Restriction of the phase matching condition on refractive index modulation of 1D photonic crystals in second harmonic generation  

Science.gov (United States)

Phase and group velocity matching equations of second harmonic generation are reconsidered for 1D photonic crystals to analyze an induced structure restriction. A multiplicity of solutions is found through a numerical computation, which separates the restricted structure parameters into infinite units. The local and global characteristics of the restriction on refractive indices and material lengths are discussed in detail as well. The analysis shows that increasing either the dispersion of the nonlinear material or the thickness of a single layer will require a larger refractive index contrast.

Wu, Huinan; Huang, Jinjer; Pu, Shaozhi; Zhang, Liuyang; Yang, Zhongying

2015-01-01

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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 res

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Blind deconvolution of seismograms regularized via minimum support  

Science.gov (United States)

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.

Royer, A. A.; Bostock, M. G.; Haber, E.

2012-12-01

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Iodine-doped-poly(3,4-ethylenedioxythiophene)-modified Si nanowire 1D core-shell arrays as an efficient photocatalyst for solar hydrogen generation.  

Science.gov (United States)

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(2) production using solar energy. PMID:22961939

Yang, Tian; Wang, Hui; Ou, Xue-Mei; Lee, Chun-Sing; Zhang, Xiao-Hong

2012-12-01

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Inpainting of historical seismograms using sparse representation method  

Science.gov (United States)

This paper presents a method of inpainting historical seismograms recorded by a pen and paper drum-type seismograph. In the seismogram, some portions of the wave may be lost or distorted owing to time marks or violent shaking. In this study, the seismic waveform is divided into several frames of equal length, and the lost or distorted portions are restored frame by frame. Because a seismogram contains several repetitive patterns in the entire waveform, each frame can be sparsely represented on the basis of these patterns. Therefore, the sparse representation model is employed to represent historical seismograms. In addition, an inpainting model that employs sparsity as a prior is formulated, and it is used to restore the lost portions by solving a L0-norm minimization problem. However, this minimization problem may be ill posed and result in an incorrect outcome if the missing interval duration of the wave is very large. Therefore, to solve this ill-posed problem, a prior based on the Fourier spectrum of the waveform is added to the inpainting method. Simulation results prove that the proposed inpainting method can restore the missing wave well.

Wang, Lifu; Sun, Yi; Cai, Xiaogang

2015-01-01

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Iodine-doped-poly(3,4-ethylenedioxythiophene)-modified Si nanowire 1D core-shell arrays as an efficient photocatalyst for solar hydrogen generation  

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

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Wavelet analysis of the seismograms for tsunami warning  

Directory of Open Access Journals (Sweden)

Full Text Available The complexity in the tsunami phenomenon makes the available warning systems not much effective in the practical situations. The problem arises due to the time lapsed in the data transfer, processing and modeling. The modeling and simulation needs the input fault geometry and mechanism of the earthquake. The estimation of these parameters and other aprior information increases the utilized time for making any warning. Here, the wavelet analysis is used to identify the tsunamigenesis of an earthquake. The frequency content of the seismogram in time scale domain is examined using wavelet transform. The energy content in high frequencies is calculated and gives a threshold for tsunami warnings. Only first few minutes of the seismograms of the earthquake events are used for quick estimation. The results for the earthquake events of Andaman Sumatra region and other historic events are promising.

A. Chamoli

2010-10-01

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S-Wave Velocity Structure beneath Southwest North America from Seismogram Comparisons of the Mexico Earthquake on 22 June 1997  

Directory of Open Access Journals (Sweden)

Full Text Available This research investigates earth structure beneath the Southwest North America landmass, especially between Mexico and California. Models based on S wave velocities for this area were obtained by carrying out seismogram fitting in time domain and three Cartesian components simultaneously. The data used is from an event, coded as C052297B that occurred in the state of Guerrero, Mexico and it was fitted to synthetic data computed with the GEMINI program at TS network stations. Earth model IASPEI91 and SPREM were used as input to create the synthetic data. Real and synthetic seismograms were subjected to a low-pass filter with a frequency corner of 20 mHz.Waveform analysis results show very unsystematic and strong deviations in the waveform, arrival times, amount of oscillation and the height of the wave amplitude. Discrepancies are met on S, Love, Rayleigh and ScS waves, where the stations epicentral distances are below 300. Deviation in analysis waveform because of the usage of model 1-D of SPREM and IASPEI91, because the 1-D was a kind of average value an elastic property at one particular depth of global earth. With the method of waveform analysis we can see how sensitive waveform is to structures within the layers of the Earth.To explain the discrepancies, a correction to the earth structure is essential. The corrections account for the thickness of the crust, speed gradient of bh, the coefficient for the bh and bv in the upper mantle for surface wave fitting, a small variation of the S speed structure at a layer under the upper mantle above 771 km for S wave fitting, and a small variation at the base the mantle layers for ScS wave fitting. At some stations, a correction for S speed structure have yielded P wave fitting. Results of this research indicate that the 1-D earth model obtained through seismogram fitting at every hypocenter-observation station pair is unique. The S-wave velocity on the upper mantle has strong negative anomalies. This paper criticized the previous earth models in the same area, which have been published by other seismologists, by analyzing the seismogram of C052297B earthquake in the TS seismological network station

Bagus Jaya Santosa

2008-09-01

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Full Waveform 3D Synthetic Seismic Algorithm for 1D Layered Anelastic Models  

Science.gov (United States)

Numerical calculation of synthetic seismograms for 1D layered earth models remains a significant aspect of amplitude-offset investigations, surface wave studies, microseismic event location approaches, and reflection interpretation or inversion processes. Compared to 3D finite-difference algorithms, memory demand and execution time are greatly reduced, enabling rapid generation of seismic data within workstation or laptop computational environments. We have developed a frequency-wavenumber forward modeling algorithm adapted to realistic 1D geologic media, for the purpose of calculating seismograms accurately and efficiently. The earth model consists of N layers bounded by two halfspaces. Each layer/halfspace is a homogeneous and isotropic anelastic (attenuative and dispersive) solid, characterized by a rectangular relaxation spectrum of absorption mechanisms. Compressional and shear phase speeds and quality factors are specified at a particular reference frequency. Solution methodology involves 3D Fourier transforming the three coupled, second- order, integro-differential equations for particle displacements to the frequency-horizontal wavenumber domain. An analytic solution of the resulting ordinary differential system is obtained. Imposition of welded interface conditions (continuity of displacement and stress) at all interfaces, as well as radiation conditions in the two halfspaces, yields a system of 6(N+1) linear algebraic equations for the coefficients in the ODE solution. An optimized inverse 2D Fourier transform to the space domain gives the seismic wavefield on a horizontal plane. Finally, three-component seismograms are obtained by accumulating frequency spectra at designated receiver positions on this plane, followed by a 1D inverse FFT from angular frequency ? to time. Stress-free conditions may be applied at the top or bottom interfaces, and seismic waves are initiated by force or moment density sources. Examples reveal that including attenuation stabilizes the numerical calculations, and reduces wraparound artifacts associated with the spatially-periodic 2D Fourier transform. Sandia National Laboratories is a multiprogram science and engineering facility operated by Sandia Corporation, a Lockheed-Martin company, for the US DOE under contract DE-AC04-94AL85000.

Schwaiger, H. F.; Aldridge, D. F.; Haney, M. M.

2007-12-01

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

KAUST Repository

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

22

A hybrid method for simulating near-source, broadband seismograms: Application to the 2003 Bam earthquake (Mw 6.5)  

Science.gov (United States)

The main objective of this article is to simulate the three components of near-source ground shaking recorded at Bam station, close to the causative fault, during the destructive the 2003 Bam earthquake, where were strongly influenced by rupture directivity effect. A hybrid technique composed of the theoretical Green's function, finite element and finite difference method proposed by Spudich et al. (1987, 2003) (COMPSYN) and a ?2-based finite-fault approach proposed by Beresnev and Atkinson (1998a) (FINSIM) are used for generating seismograms at low and high frequencies respectively. A Genetic algorithm technique is developed for minimizing the differences between the recorded and simulated data incorporating parameters within a predefined upper/lower bound's values previously estimated for main shock by other investigators. Two different faulting models, consist of a straight line segment and a straight line segment followed by a slightly north-eastward branch, are used. The simulated three component seismograms at Bam station, in terms of elastic response spectra, are validated by comparing the simulated time series with those of the observed data. Moreover, the pulses involved in the recorded time series due to the rupture directivity are estimated and compared with those of the observed data. A sensitivity analysis is performed for recognizing the influence of model parameter changes, such as focal mechanism (strike, dip and rake), rise-time, rupture velocity and hypocenter location on the simulated seismograms. Relatively good match of the simulated and observed time series, particularly the two faulting models, confirm the potentiality of the proposed technique and the suitability of seismological model parameters used. This technique can be used for specific site hazard analysis of the Bam region and linear/nonlinear dynamic analysis of structures where were damaged during the Bam earthquake particularly for retrofitting the well known international adobe buildings of Arg-e-Bam.

Nicknam, Ahmad; Eslamian, Yasser

2010-05-01

23

0-D and 1-D inorganic-organic composite polyoxotungstates constructed from in-situ generated monocopperII-substituted Keggin polyoxoanions and copperII-organoamine complexes  

International Nuclear Information System (INIS)

Combination of in-situ generated monocopperII-substituted Keggin polyoxoanions with copperII-organoamine complexes under hydrothermal conditions results in seven inorganic-organic composite polyoxotungstates [Cu(en)2(H2O)]2{[Cu(en)2][?-PCuW11O39Cl]}.3H2O (1), {[Cu(en)2(H2O)][Cu(en)2]2[?-PCuW11O39Cl]}.6H2O (2), {[Cu(en)2(H2O)]2[Cu(en)2][?-XCuW11O39]}.5H2O (3/4, X=SiIV/GeIV), {[Cu(deta)(H2O)2]2[Cu(deta)(H2O)][?-XCuW11O39]}.5H2O (5/6, X=GeIV/SiIV) and [Cu(dap)2]2{[Cu(dap)2]2[Cu(dap)2][?-PCuW11O39]2} (7) (en=ethylenediamine, dap=1,2-diaminopropane and deta=diethylenetriamine). 1 is an isolated structure whereas 2 is a 1-D chain structure, but both contain [?-PCuW11O39Cl]6- polyoxoanions. 3-6 contain the 1-D linear chains made up of [?-XCuW11O39]6- polyoxoanions in the pattern of -A-A-A- (A=[?-XCuW11O39]6-), while 7 demonstrates the first 1-D zigzag chain constructed from [?-PCuW11O39]211O39]210- polyoxoanions via [Cu(en)2]2+ bridges in the pattern of -A-B-A-B- (A=[?-PCuW11O39]210-, B=[Cu(en)2]2+). The successful syntheses of 1-7 can provide some experimental evidences that di-/tri-/hexa-vacant polyoxoanions can be transformed into mono-vacant Keggin polyoxoanions under hydrothermal conditions. - Graphical abstract: A family of inorganic-organic composite polyoxotugstates have been harvested by combination of in-situ generated monocopperII-substituted Keggin polyoxoanions and copperII-organoamine complexes based on di-/tri-/hexa-vacant polyoxoanion precursors, CuCl2.2H2O and organoamines under hydrothermal conditions and structurally characterized by the elemental analysis, IR spectroscopy, TGA and single-crystal X-ray crystallography

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Further experimental investigation of the correct Q1D electrodynamical part of a model for the fluid flow in a Faraday segmented MHD generator channel  

Energy Technology Data Exchange (ETDEWEB)

The correct quasi-one-dimensional (Q1D) electrodynamical part (the electric current density vector in a working fluid has only one component: j{sub y}) of a model for the fluid flow in a Faraday ideally segmented (absence of the Hall electric current: I{sub x} = O) generator channel was developed. In this paper, the validity of the model is demonstrated for the electric currents of interest for commercial MHD energy conversion with combustion products as a working fluid [3], and the semi-empirical factor {Delta}x from the model is further investigated. It seems that in modeling in electrodynamics or electromagnetics the consequences of taking an assumption, better say a simplification, are the same as in fluid dynamics. We cut some of the connections of a model with reality, i.e. we partially destroy some of the equations and then they can be only partially satisfied. In question are the models of fluid flow in a Faraday ideally segmented channel, which have the Q1D electrodynamical part as defined above, or based on the assumption that the x component (besides j{sub z} = O, E{sub z} = O) of the Faraday current j{sub x} does not exist in the core of the flow, e.g. [3-6]. The assumption that the electric current flows inside a channel through the whole cross section of a segment (s2b), even in the core of the flow, does not correspond to reality [14]. It leads to an underestimation of the working fluid electrical resistance. One has to admit that in the frame of the assumption j{sub x} = O it is impossible to describe the reality inside a channel. But, it is still possible to describe the global characteristics of a generator: electrical output, electrical and thermal efficiency, etc. with the Q1D model ligitimate regarding the equation of conservation of charges (div j = O for the stationary electric current) [1]. (author)

Bajovic, V.S. [Technische Hogeschool Eindhoven (Netherlands). Dept. of Electrical Engineering

1994-12-01

25

An XML-SEED Format for the Exchange of Synthetic Seismograms  

Science.gov (United States)

We have demonstrated that we can calculate global theoretical seismograms for realistic 3D Earth models based upon the combination of a precise numerical technique (the spectral-element method) and a sufficiently fast supercomputer (the Earth Simulator) [Tsuboi et al, 2003]. It has now become possible to routinely calculate synthetic seismograms for earthquakes greater than a certain magnitude. We have started to create a synthetic seismogram database by using model S20RTS of the mantle (Ritsema et al., 1999), model CRUST2.0 of the crust (Basin et al., 2000), and topography and bathymetry model ETOPO5. The calculations are performed on 1944 processors, which require 243 out of 640 nodes of the Earth Simulator. Starting in 2003, we select earthquakes with magnitudes greater than 6.5 from the Harvard CMT catalog and calculate theoretical seismograms for the Stations in the Global Seismographic Network. To distribute this synthetic seismogram database to the seismological community, the data format of the seismograms becomes an issue because the SEED format, which is currently used for the exchange of broadband seismic data, does not have an entry for the metadata that characterize the theoretical seismograms. To overcome this problem, we extend the SEED format by using the eXtended Markup Language (XML) and propose this format as a possible standard for the exchange of theoretical seismograms. The representation of SEED volumes in XML has already been explored by the IFREE/JAMSTEC data center. We believe that the use of XML to extend the SEED format to accommodate the exchange of theoretical seismograms is promising because XML is easy to modify and is used as a basic protocol of network tools, such as Web services. We adopt this representation of SEED volumes in XML and extend it to include metadata entries for the theoretical seismogram database. The entries that we have added to this format uniquely characterize the simulation that was performed to create the synthetics. Currently, each data sample is represented by a character, but it should be possible to include binary formatted data, such as mini-SEED. We will soon distribute these theoretical seismograms through mirrored IFREE/JAMSTEC and Caltech web interfaces.

Tsuboi, S.; Tromp, J.; Komatitsch, D.

2004-12-01

26

Data space reduction, quality assessment and searching of seismograms: Autoencoder networks for waveform data  

OpenAIRE

What makes a seismogram look like a seismogram? Seismic data sets generally contain waveforms sharing some set of visual characteristics and features—indeed, seismologists routinely exploit this when performing quality control ‘by hand’. Understanding and harnessing these characteristics offers the prospect of a deeper understanding of seismic waveforms, and opens up many potential new techniques for processing and working with data. In addition, the fact that certain features are share...

Valentine, A. P.; Trampert, J.

2012-01-01

27

Investigating the Tsunamigenic Potential of Earthquakes from Analysis of the Informational and Multifractal Properties of Seismograms  

Science.gov (United States)

Revealing the tsunamigenic potential of an earthquake is very challenging in regards to minimizing the casualties a tsunami can provoke. Thus, development of methodologies that can reliably furnish a early warnings of a tsunami is crucial. In order to accomplish this aim it is important to preliminarily identify the characteristics of seismograms that can be used to distinguish tsunamigenic (TS) earthquakes from non-tsunamigenic (NTS) earthquakes. In this paper P-wave time dynamic of 17 seismograms of TS earthquakes and 26 NTS seismograms are analysed by means of two advanced statistical tools: the Fisher-Shannon method and the multifractal detrended fluctuation analysis (MFDFA). Both methods are well suited to disclosing the inner time properties of complex signals, as seismograms appear to be. Using these two methods jointly, we defined a classifier, the performance of which was tested by means of the receiver-operating characteristic curve that plots true positive rate versus false positive rate. This classifier shows a discrimination power that can be considered acceptable in comparison with the devastating effects caused by a non-alarmed tsunami. Our findings indicate that proper choice of the classifier's threshold allows correctly identification of approximately 69 % of the NTS seismograms and approximately 76 % of the TS seismograms. The presented results presented may be helpful in addressing the complex problem of early tsunami warning.

Telesca, Luciano; Chamoli, Ashutosh; Lovallo, Michele; Stabile, Tony Alfredo

2014-06-01

28

Seismogram Analysis of C052198B Earthquake, Minahasa at Observatory Stations in Australia  

Directory of Open Access Journals (Sweden)

Full Text Available The earth structure between the Minahasa earthquake, coded as C052198B, and observatory stations in Australia has been investigated through analysis in the time domain of three-component seismograms. The synthetic seismograms are constructed from an earth model, the CMT solution of the earthquake and station locations. The calculation is based on the GEMINI method, and the corner frequency is set at 20 mHz. Using deconvolutions of the station instruments responses, the measured and synthetic seismogram can be compared with the same units. The seismogram comparison indicates discre-pancies between recorded data and synthetic seismograms calculated from the anisotropic PREM model, in the travel times of Rayleigh and Love surface wave, as well as the S and core reflected ScS and ScS2 body waves. Discrepancies of Love wave travel time and the number of oscillations are explained by changes in the crustal velocity model and by setting the positive gradient of ?h in the upper mantle. While for Rayleigh waves and arrival times of body waves, corrections to the zero order coefficients of ? are needed at layers in the mantle. The interpretation of the results of the waveform analyses indicates strong anisotropy in the upper mantle. The anisotropy also occurs, to a lesser extent, at layers beneath the upper mantle.

Bagus Jaya Santosa

2012-03-01

29

Ray synthetic seismograms: a useful tool in the International Data Center environment  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper some of the results of a feasibility study on ray synthetic seismograms usage are reported. A computational method, ways of composing synthetic traces, an application of the source wavelet and the radiation pattern and integration of such an approach into the Center for Seismic Studies (CSS revision 3.0 structure are outlined. Further on, results obtained for model examples, nuclear explosions, and earthquakes are presented. Conclusions of the undertaken feasibility study help to understand that ray synthetic seismograms represent a very fast tool (results in ?no time? and simultaneously represent a complex tool with all needed features. The ray synthetic seismograms can be implemented in various ways: to be computed automatically and used within the Intelligent Monitoring System, to be computed automatically and provided to the analyst, to provide a database of master events, to be computed interactively by an analyst during routine daily analysis.

P. Firbas

1994-06-01

30

Source mechanisms and near-source wave propagation from broadband seismograms  

Directory of Open Access Journals (Sweden)

Full Text Available Recording seismic events at teleseismic distances with broadband and high dynamic range instruments provides new high-quality data that allow us to interpret in more detail the complexity of seismic rupture as well as the heterogeneous structure of the medium surrounding the source where waves are initially propagating. Wave propagation analysis is performed by ray tracing in a local cartesian coordinate system near the source and in a global spherical coordinate system when waves enter the mantle. Seismograms are constructed at each station for a propagation in a 2.5-D medium. Many phases can be included and separately analyzed; this is one of the major advantages of ray tracing compared to other wave propagation techniques. We have studied four earthquakes, the 1988 Spitak Armenia Earthquake (Ms = 6.9, the 1990 Iran earthquake (Ms = 7.7, the 1990 romanian earthquake (Ms = 5.8 and the 1992 Erzincan, Turkey earthquake (Ms = 6.8. These earthquakes exhibit in different ways the complexity of the rupture and the signature of the medium surrounding the source. The use of velocity seismograms, the time derivative of displacement, increases the difficulty of the fit between synthetic seismograms and real seismograms but provides clear evidence for a need of careful time delay estimations of the different converted phases. We find that understanding of the seismic rupture as well as the influence of the medium surrounding the source for teleseismically recorded earthquakes requires a multi-stop procedure: starting with ground displacement seismograms, one is able to give a first description of the rupture as well as of the first-order influence of the medium. Then, considering the ground velocity seismograms makes the fit more difficult to obtain but increases our sensitivity to the rupture process and early converted phases. With increasing number of worldwide broadband stations, a complex rupture description is possible independently of field observations, which can be used to check the adequacy of such complicated models.

J. Perrot

1994-06-01

31

Generation of a pseudo-2D shear-wave velocity section by inversion of a series of 1D dispersion curves  

Science.gov (United States)

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

32

Synthetic Seismogram Based Deterministic Seismic Zoning for the Hungarian Part of the Pannonian Basin  

Science.gov (United States)

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.

33

Class Room Exercises Using JMA-59-Type Seismograms for Earthquake Study at High-School Level  

Science.gov (United States)

The JMA-59-type electromagnetic seismograph was the standard seismograph for routine observations by the Japan Meteorological Agency (JMA) from the 1960's to the 1990's. Some features of those seismograms include 1) displacement wave records (electrically integrated from a velocity output by a moving-coil-type sensor), 2) ink records on paper (analog recording with time marks), 3) continuous drum recording for 12 h, and 4) lengthy operation time over several decades. However, the digital revolution in recording systems during the 1990's made these analog features obsolete, and their abundant and bulky paper-based records were stacked and sometimes disregarded in the library of every observatory. Interestingly, from an educational aspect, the disadvantages of these old-fashioned systems become highly advantageous for educational or outreach purposes. The updated digital instrument is essentially a 'black-box,' not revealing its internal mechanisms and being too fast for observing its signal processes. While the old seismometers and recording systems have been disposed of long since, stacks of analog seismograms continue to languish in observatories' back rooms. In our study, we develop some classroom exercises for studying earthquakes at the mid- to high-school level using these analog seismograms. These exercises include 1) reading the features of seismic records, 2) measuring the S-P time, 3) converting the hypocentral distance from Omori's distance formula, 4) locating the epicenter/hypocenter using the S-P times of surrounding stations, and 5) estimating earthquake magnitude using the Tsuboi's magnitude formula. For this calculation we developed a 'nomogram'--a graphical paper calculator created using a Python-based freeware tool named 'PyNomo.' We tested many seismograms and established the following rules: 1) shallow earthquakes are appropriate for using the Tsuboi's magnitude formula; 2) there is no saturation at peak amplitude; 3) seismograms make it easy to read S-P time and maximum amplitude; 4) they also make it is easy to locate an earthquake's hypocenter. For advanced study, particularly of the source mechanisms of earthquakes, P-wave arrival phases are typically determined from wave records. In this exercise, we use displacement-based records for use by students for recognizing these arrival phases directly rather than by using velocity or acceleration records. Following are some advantages of using these JMA-59-type seismograms: 1) displacement records are easy to compare with real ground motion; 2) ink records can help young students visualize the analog images of a legacy seismograph; 3) scale dimensions such as amplitude of 100 times and time scale of 1 mm/s are easy to explain while using these seismograms as an exercise resource. We confirmed the availability of our exercises by cooperation with our high-school students. We will offer some practical examples at the conference. Keywords: JMA-59 type seismograph, seismograms, hypocenter location, magnitude estimation, educational tool, classroom exercise, high-school

Okamoto, Y.; Furuta, S.; Hirota, N.

2013-12-01

34

Seismogram Analysis of Earthquakes Around Indonesia In UGM Observational Station: S Velocity Structure.  

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

35

An EGF-based methodology for predicting compatible seismograms in the spectral domain using GA technique  

Science.gov (United States)

The main objective of this paper is to present a methodology for predicting spectrum compatible seismograms at sites where main shock is not recorded by other sites from which the main event has been observed using recorded aftershocks. The genetic algorithm and multitaper method are employed to minimize differences between the calculated synthetic seismogram and observed data. The multitaper spectrum approach being used permits the reduction of spectral leakage providing the possibility of matching the Fourier spectral amplitudes corresponding to synthetic and observed waveforms. The proposed technique is applied to the 2006 Silakhor earthquake (Mw= 6.1, Iran) as a case study. The six component waveforms (L, T and V) at two stations were simulated by minimizing errors between the synthetic response spectra, the Fourier spectral amplitudes and those of the observed. The results are shown to be in a good agreement with those of the observed data. The three components of waveforms at the other three stations were predicted incorporating the calculated parameters. The validity of the technique is proven through demonstrating good agreement of the response spectra and Fourier spectral amplitudes corresponding to the predicted and observed seismograms at other three stations. It is concluded that, the methodology is applicable for predicting realistic acceleration time histories to be used in seismic performance evaluation of existing structures in the region under study.

Nicknam, Ahmad; Eslamian, Yasser

2011-04-01

36

A novel technique for automatic seismic data processing using both integral and local feature of seismograms  

Science.gov (United States)

A novel technique for automatic seismic data processing using both integral and local feature of seismograms was presented in this paper. Here, the term integral feature of seismograms refers to feature which may depict the shape of the whole seismograms. However, unlike some previous efforts which completely abandon the DIAL approach, i.e., signal detection, phase identification, association, and event localization, and seek to use envelope cross-correlation to detect seismic events directly, our technique keeps following the DIAL approach, but in addition to detect signals corresponding to individual seismic phases, it also detects continuous wave-trains and explores their feature for phase-type identification and signal association. More concrete ideas about how to define wave-trains and combine them with various detections, as well as how to measure and utilize their feature in the seismic data processing were expatiated in the paper. This approach has been applied to the routine data processing by us for years, and test results for a 16 days' period using data from the Xinjiang seismic station network were presented. The automatic processing results have fairly low false and missed event rate simultaneously, showing that the new technique has good application prospects for improvement of the automatic seismic data processing.

Jin, Ping; Zhang, Chengliu; Shen, Xufeng; Wang, Hongchun; Pan, Changzhou; Lu, Na; Xu, Xiong

2014-06-01

37

Waveform modelling using locked-mode synthetic and differential seismograms: application to determination of the structure of Mexico  

Science.gov (United States)

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

Using regional geophysical databases to facilitate the identification of surface reflections on P seismograms  

Science.gov (United States)

The relative amplitude method allows the focal mechanism of an earthquake to be determined using the relative amplitudes of P and the surface reflections pP and sP observed on P seismograms recorded at long range. Regional structural information is helpful when interpreting P seismograms in terms of P, pP, sP and other arrivals such as near-source S-to-P conversions. Here we re-interpret array seismograms from the 1972 January 12 Gulf of Suez earthquake and demonstrate that many of the regionally dependent parameters, required by the method, can be obtained not only from conventional published sources, but also from geophysical databases that can be easily accessed via the internet. For example, one interpretation of the P seismogram recorded by the seismometer array at Gauribidanur, India (GBA), from the Gulf of Suez earthquake is that the first large-amplitude arrival after P is pP, followed by sP. However, modelling shows that this interpretation requires an anomalously high Poisson's ratio in the above-source structure. After careful consideration of plausible arrival times and relative amplitudes of P, pP and sP at GBA and on seismograms recorded by two other arrays, our preferred model has a focal mechanism with ?s=105°, ?=85°, ?=-165° and a source depth of 7.8km in a Poisson crust 23km thick. In our preferred model, the first large-amplitude arrival after P at GBA is not pP, but an S-to-P conversion at the Moho (independent studies suggest the Moho is about 25km deep in the epicentral region). Our example demonstrates that the relative amplitudes of P and surface reflections have the potential to identify seismic disturbances that are too deep to be possible violations of the Comprehensive Nuclear Test Ban Treaty (CTBT). The availability of data from seismometer arrays (within the International Monitoring System) and easily accessible geophysical databases containing regional structural parameters will allow the relative amplitude method to be used to help verify the CTBT.

Bowers, David; Pearce, Robert G.; Douglas, Alan

2000-09-01

39

Rock avalanche dynamics evidenced by near-field strongmotion seismogram  

Science.gov (United States)

Giant landslides have been argued to have some distinctive physical properties such that they can achieve high speed sliding and long runout distance. Although estimating their physical properties is difficult, it is nevertheless crucial for landslide assessments. The idea assessments are from direct measurements when they are at motion. However, due to their scarce occurrences and short flowing durations, they have rarely been instrumentally recorded. In Tsaoling area, Taiwan, there have been historically documented four giant landslides since the late 19th century because of its unique geological condition and, therefore, seismological equipments have been installed around the area since the 90s to monitor the regional seismic activities and its topographic amplification effects. In 1999, Chi-Chi earthquake triggered the fifth major landslide, with a scar volume 0.125 km3. Due to its volume and site locality to the seismic instrument array, the landslide induced ground motion was expected to be captured. We cross examine the records of the surrounding seismic stations and find that only the nearest station, CHY080, exhibits distinguished signatures which may be associated with the landslide. We use the Ensemble Empirical Mode Decomposition (EEMD) to decompose the signals which identify a series of peculiar wave packets. Based on it, a simple rigid sliding model is deployed to analyze the sliding process for physical quantities of the landslide. The results reveal that with the sliding distance 1994 m, the maximum velocity reaches ~ 78 m/s, and the mass generates a large collision impact against the riverbed and the steep slope on the other side of the river. The friction angle of the sliding surface could be estimated and suggested as low as 6.9° so as to achieve a high velocity sliding. These results are agreeable with kinematic simulation of the landslide and provide evidence that the landslide induces seismic ground motion. The revealed results provide a solid evidence and create a new high record for the massive and high speed landslide.

Chang, Kuo-Jen; Kuo, Chih-Yu; Chen, Rou-Fei; Chan, Yu-Chang

2010-05-01

40

Predicting the distribution of reservoirs by combining variable wavelet model of seismograms with wavelet edge analysis and modeling  

Science.gov (United States)

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

41

Data space reduction, quality assessment and searching of seismograms: autoencoder networks for waveform data  

Science.gov (United States)

What makes a seismogram look like a seismogram? Seismic data sets generally contain waveforms sharing some set of visual characteristics and features - indeed, seismologists routinely exploit this when performing quality control 'by hand'. Understanding and harnessing these characteristics offers the prospect of a deeper understanding of seismic waveforms, and opens up many potential new techniques for processing and working with data. In addition, the fact that certain features are shared between waveforms suggests that it may be possible to transform the data away from the time domain, and represent the same information using fewer parameters. If so, this would be a significant step towards making fully non-linear tomographic inversions computationally tractable. Hinton & Salakhutdinov showed that a particular class of neural network, termed 'autoencoder networks', may be used to find lower-dimensional encodings of complex binary data sets. Here, we adapt their work to the continuous case to allow the use of autoencoders for seismic waveforms, and offer a demonstration in which we compress 512-point waveforms to 32-element encodings. We also demonstrate that the mapping from data to encoding space, and its inverse, are well behaved, as required for many applications. Finally, we sketch a number of potential applications of the technique, which we hope will be of practical interest across all seismological disciplines, and beyond.

Valentine, Andrew P.; Trampert, Jeannot

2012-05-01

42

Synthetic Seismograms for Realistic 3D Earth Model with Anisotropic Inner Core  

Science.gov (United States)

We have demonstrated that we can calculate global theoretical seismograms for realistic 3D Earth models based upon the combination of a precise numerical technique (the spectral-element method) and a sufficiently fast supercomputer (the Earth Simulator) [Tsuboi et al, 2003]. Here we have calculated synthetic seismograms by using model S20RTS of the mantle (Ritsema et al., 1999), model CRUST2.0 of the crust (Basin et al., 2000), topography and bathymetry model ETOPO5, and anisotropic inner core model (Ishii 2002). The calculations are performed on 4056 processors, which require 507 out of 640 nodes of the Earth Simulator. These synthetics are computed by using SPECFEM3D(Komatitsch and Tromp, 2002) and are accurate up to 3.5 seconds. We have calculated these synthetics with aisotropic inner core model for several earthquakes and compared with the synthetics which are calculated for isotropic inner core model. Preliminary comparison shows that the travel time differences between anisotropic inner core model and isotropic core model for PKPab phases are at most a few seconds. There seems to be no significant differences in waveforms of PKP phases. These differences in travel times may help us to improve inner core fine structure by comparing these synthetics with observation.

Tsuboi, S.; Tono, Y.

2006-12-01

43

A simple derivation of the formula to calculated synthetic long-period seismograms in a heterogeneous Earth by normal mode summation  

Science.gov (United States)

A simple modification of Gilbert's formula to account for slight lateral heterogeneity of the Earth leads to a convenient formula to calculate synthetic long period seismograms. Partial derivatives are easily calculated, thus the formula is suitable for direct inversion of seismograms for lateral heterogeneity of the Earth.

Tanimoto, T.

1983-01-01

44

A simple derivation of the formula to calculate synthetic long-period seismograms in a heterogeneous earth by normal mode summation  

Science.gov (United States)

A simple modification of Gilbert's formula to account for slight lateral heterogeneity of the earth leads to a convenient formula to calculate synthetic long period seismograms. Partial derivatives are easily calculated, thus the formula is suitable for direct inversion of seismograms for lateral heterogeneity of the earth. Previously announced in STAR as N83-29893

Tanimoto, T.

1984-01-01

45

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

Science.gov (United States)

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

46

High-frequency Born synthetic seismograms based on coupled normal modes  

Science.gov (United States)

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

47

First-order P-wave ray synthetic seismograms in inhomogeneous, weakly anisotropic, layered media  

Science.gov (United States)

The calculation of first-order P-wave ray synthetic seismograms based on first-order ray tracing (FORT) and dynamic ray tracing (FODRT) for P-waves propagating in inhomogeneous, weakly anisotropic media is extended from smooth to layered media. All the basic formulae necessary to calculate the P-wave FORT and FODRT quantities inside layers and to transform them at the points of reflection/transmission are given. The proposed formulae are applicable in subcritical as well as overcritical regions. The accuracy of the results is tested by comparing the approximate (FORT) results with the results obtained from a standard ray tracer for anisotropic media. The tests indicate that, except for critical regions, where the ray theory provides incorrect results anyway, the accuracy of FORT and FODRT in layered media is comparable with the accuracy in smooth media.

Pšen?ík, Ivan; Farra, Véronique

2014-07-01

48

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

49

Analysis of seismogram envelopes. State of the art and future developments; Jishin hakei no envelope kaiseki. Genjo to kongo no kadai  

Energy Technology Data Exchange (ETDEWEB)

Reviewed herein are researches on seismogram envelopes of small earthquakes and observations. The physical exploration tries to search for coherent portions in the waves by array observation, to detect strong contrasts in underground structures. Analysis of seismogram envelopes is much different from the above. The coda wave in the seismogram of local earthquake is characterized by a structure of random short-waves overlapping three-dimensionally the upper surface of a gradually changing structure. This paper describes characteristics of heterogeneous earth structures and coda waves, modeling based on the radiation propagation theories, and simulation and analysis examples of 3-component, total waveform envelopes, based on the Born approximation in the theory of elasticity. It also outlines the envelopes, in the seismograms of earthquakes which have occurred in the Kanto and Tokai districts, changing from a pulse-shape to spindle-shape, theoretical models developed by diffractiometry for strongly random heterogeneous structures, and future research prospects. 37 refs., 28 figs.

Sato, H. [Tohoku University, Sendai (Japan)

1998-10-01

50

Synthetic Seismograms in Transversely Isotropic Plane Layered Media Sismogrammes synthétiques dans les milieux stratifiés présentant une isotropie plane  

OpenAIRE

The purpose of the work presented in the paper, is to compute the response of transversely isotropic plane layered media excited by a buried or surface source, in order to obtain a method which can help interpreting real seismograms. The computation in frequency f and wavenumber k domain based on the Kennett's reflectivity method is exposed. Displacements in space and time are calculated by numerical integration (Fourier-Hankel transform) of the response in frequency and wavenumber domain. Th...

Guennou C.

2006-01-01

51

A program for rapid computation of multioffset vertical seismic profile synthetic seismograms for layered media  

Science.gov (United States)

PNSEB is a set of FORTRAN programs for calculating the response of a layered elastic medium using the reflectivity method as described in Mallick and Frazer (Practical Aspects of Reflectivity Modeling, Geophysics 52, 1355-1364, 1987; Rapid Computation of Multi-offset VSP Synthetic Seismograms for Layered Media, Geophysics 53, 479-491, 1988). PNSEB consists of two basic modules, each of which consists of more than one major option. The first module, PNSN, calculates the earth's response (Green's function) in frequency-wavenumber (omega-p) space. Using the proper option, the program can calculate the response at very small or very large offsets. No lateral variability or anisotropy are allowed, but the full response including interface waves is calculated. The second module, PNSYN, in its main form converts the output from PNSN to time-distance (t-x) space, which can then be plotted by the VSPLT module or by other plotting packages. The program has been written and optimized for vector computers, such as a Cray or Convex, but also runs well on scalar computers such as Sun workstations.

Lindwall, Dennis; Mallick, Subhashis

1994-01-01

52

MineSeis -- A MATLAB GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model  

Energy Technology Data Exchange (ETDEWEB)

Modeling ground motions from multi-shot, delay-fired mining blasts is important to the understanding of their source characteristics such as spectrum modulation. MineSeis is a MATLAB{reg_sign} (a computer language) Graphical User Interface (GUI) program developed for the effective modeling of these multi-shot mining explosions. The program provides a convenient and interactive tool for modeling studies. Multi-shot, delay-fired mining blasts are modeled as the time-delayed linear superposition of identical single shot sources in the program. These single shots are in turn modeled as the combination of an isotropic explosion source and a spall source. Mueller and Murphy`s (1971) model for underground nuclear explosions is used as the explosion source model. A modification of Anandakrishnan et al.`s (1997) spall model is developed as the spall source model. Delays both due to the delay-firing and due to the single-shot location differences are taken into account in calculating the time delays of the superposition. Both synthetic and observed single-shot seismograms can be used to construct the superpositions. The program uses MATLAB GUI for input and output to facilitate user interaction with the program. With user provided source and path parameters, the program calculates and displays the source time functions, the single shot synthetic seismograms and the superimposed synthetic seismograms. In addition, the program provides tools so that the user can manipulate the results, such as filtering, zooming and creating hard copies.

Yang, X.

1998-12-31

53

Data Mining for Tectonic Tremor in a Large Global Seismogram Database using Preprocessed Data Quality Measurements  

Science.gov (United States)

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

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

A comparison of two methods for earthquake source inversion using strong motion seismograms  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we compare two time-domain inversion methods that have been widely applied to the problem of modeling earthquake rupture using strong-motion seismograms. In the multi-window method, each point on the fault is allowed to rupture multiple times. This allows flexibility in the rupture time and hence the rupture velocity. Variations in the slip-velocity function are accommodated by variations in the slip amplitude in each time-window. The single-window method assumes that each point on the fault ruptures only once, when the rupture front passes. Variations in slip amplitude are allowed and variations in rupture velocity are accommodated by allowing the rupture time to vary. Because the multi-window method allows greater flexibility, it has the potential to describe a wider range of faulting behavior; however, with this increased flexibility comes an increase in the degrees of freedom and the solutions are comparatively less stable. We demonstrate this effect using synthetic data for a test model of the Mw 7.3 1992 Landers, California earthquake, and then apply both inversion methods to the actual recordings. The two approaches yield similar fits to the strong-motion data with different seismic moments indicating that the moment is not well constrained by strong-motion data alone. The slip amplitude distribution is similar using either approach, but important differences exist in the rupture propagation models. The single-window method does a better job of recovering the true seismic moment and the average rupture velocity. The multi-window method is preferable when rise time is strongly variable, but tends to overestimate the seismic moment. Both methods work well when the rise time is constant or short compared to the periods modeled. Neither approach can recover the temporal details of rupture propagation unless the distribution of slip amplitude is constrained by independent data.

G. C. Beroza

1994-06-01

56

A semigroup for Lagrangian 1D isentropic flow  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses a system of Lagrangian equations used to describe 1D isentropic flow. This paper covers the approximate differential equations, the Banach space re-metrization and semigroup generation. 10 refs.

Pimbley, G.H.

1988-01-01

57

Terahertz Signal Generation in 1-D Photonic Crystals Terahertz Signal Generation in 1-D Photonic Crystals  

OpenAIRE

Theoretical and numerical results are presented to assure that a tunable, narrow-band, coherent THz radiation source can be based on parametric down-conversion in aphotonic crystal. Our proposal is based on down-conversion mixing and a local-field enhancement mechanism that is available by tuning each of the two driving laserfields either to band-edge or to a defect mode in the band gap. The frequency of the down-converted signal can be tuned by intersecting two non co-linear laser sources. T...

Mónica Trejo; Ángel González; Ibarra-manzano, O.; Estudillo-ayala, J.; Rojas-laguna, R.; Gonza?lez-barboza, J.; Andrade-lucio, A.; Alvarado-me?ndez, E.; Castro-sa?nchez, R.; Guzma?n-cabrera, R.; Aguilera-corte?s, L. A.; Haus, J. W.; Torres-cisneros, M.

2012-01-01

58

Terahertz Signal Generation in 1-D Photonic Crystals Terahertz Signal Generation in 1-D Photonic Crystals  

Directory of Open Access Journals (Sweden)

Full Text Available Theoretical and numerical results are presented to assure that a tunable, narrow-band, coherent THz radiation source can be based on parametric down-conversion in aphotonic crystal. Our proposal is based on down-conversion mixing and a local-field enhancement mechanism that is available by tuning each of the two driving laserfields either to band-edge or to a defect mode in the band gap. The frequency of the down-converted signal can be tuned by intersecting two non co-linear laser sources. The polarizations are degenerate at normal incidence and have sub-THz down-conversion maximum. For aspecific sample geometry we show that by changing the angle of incidence of one tunable laser to 30 degrees the THz frequency is about11.5 THz for p-polarization and 3.5THz for s-polarization, since the angle-dependent transmission spectrum is different for p- and spolarizations.The peak conversion efficiency for both polarizations is enhanced by over two orders of magnitude. Finally we also introduce some preliminary experimental results which agree with the numerical results we present here.En este trabajo presentamos resultados teóricos y numéricos que aseguran poder obtener una fuente de radiación coherente, sintonizable y de banda angosta en la región terahertzdel espectro electromagnético. Nuestra propuesta se basa en el efecto de conversión paramétrica no lineal y en el mecanismo de amplificación delcampo. Estos efectos se obtienen simultáneamente al sintonizar dos fuentes láser en la orilla de la banda prohibida o en el modo de un defecto localizado del cristal fotónico. La frecuencia de la señal obtenida puede ser sintonizada al mezclar las dos fuentes láser con diferente ángulo de incidencia. Las polarizaciones son degeneradas a un ángulo de incidencia normal y la conversión paramétrica genera señales sub-terahertz. Para una muestra específica, mostramos que cambiando el ángulo de incidencia de un láser sintonizable a 30 grados,la frecuencia de la señal obtenida en el cristal es de 11.5 THz para la polarización p y de 3.5 THz para la polarización s. Esto es debido a que el espectro de transmisión es dependientedel ángulo y por lo tanto, existen diferencias para la polarización p y para la s. La eficiencia de conversión pico para ambas polarizaciones es amplificada por más de dos órdenes de magnitud. Finalmente, también se muestran algunos resultados experimentales preliminares que concuerdan con los resultados numéricos que presentamos en este artículo.

Mónica Trejo

2012-02-01

59

Reducing Uncertainties in the Velocities Determined by Inversion of Phase Velocity Dispersion Curves by Using Synthetic Seismograms  

Science.gov (United States)

The use of Rayleigh waves phase velocity dispersion curves for the determination of shallow shear-wave velocity profiles is widespread in the context of geotechnical, earthquake engineering, and seismic hazard applications because it is a low-cost technique. A significant problem with this technique, however, is its intrinsic non-uniqueness, and although this problem is widely recognized, there have not been systematic efforts to develop approaches to reduce the pervasive uncertainty that affects the velocity profiles determined by the inversion. To minimize the lack of uniqueness different methodologies can be combined together. Genetic algorithms (GA) can be used to maximize the probability of finding the global optimum. Furthermore, considering higher modes of propagation will help reducing the non-uniqueness problem. Here, we present one approach based on the use of synthetic seismograms, which has been tested successfully with synthetic data designed to resemble actual data. For example, two completely different velocity models produce essentially the same dispersion curves for the fundamental mode and the first three higher modes, which mean that there is no objective way to discriminate between the two models. On the other hand, the corresponding synthetic traces have significant differences, which allow choosing the appropriate velocity model. The goal of this study is to apply the synthetic seismogram technique to data collected with method of multi-channel analysis of surface waves (MASW). We use simulated tests to assess the usefulness and the limitations of this technique. We use a target velocity profile with an assumed water level for calculation of synthetic experimental dispersion curve, which is used in the inversion process. The inversion process results in several different inverted velocity profiles with theoretical dispersion curves similar to the target dispersion curve. Applying the synthetic seismogram technique, it is possible to robustly find the inverted velocity of the target profile.

Hosseini, M.; Pezeshk, S.; Pujol, J. M.

2012-12-01

60

Refinement of parameters of weak nuclear explosions conducted at the Semipalatinsk test site on the basis of historical seismograms study  

Science.gov (United States)

Many researchers working in the field of monitoring and discriminating of nuclear tests encounter the problem of lacking in seismic catalogues the information about source parameters for weak nuclear explosions. As usual, the information about origin time, coordinates and magnitude is absent, there is information about date, approximate coordinates and information about explosion yield. Huge work conducted on recovery of parameters of small underground nuclear explosions conducted at the Semipalatinsk Test Site using records of analogue seismic stations of the USSR located at regional distances was conducted by V. Khalturin, T. Rayutian, P. Richards (Pure and Applied Geophysics, 2001). However, if underground nuclear explosions are studied and described in literature quite well, then air and contact explosions were small and were not recorded by standard permanent seismic stations. In 1961-1962 maximum number of air and contact explosions was conducted at Opytnoye polye site of the STS. We managed to find and analyze additional seismic data from some temporary and permanent stations. That time IPE AS USSR installed a network of high-sensitive stations along Pamir-Baykal profile to study earth crust structure and upper mantle, the profile length was 3500 km. Epicentral distance from some stations of the profile to Opytnoye polye was 300-400 km. In addition, a permanent seismic station Semipalatinsk (SEM) located 175 km away from the site started its operation. The seismograms from this station became available recently. The digitized historical seismograms allowed to recover and add parameters for more than 36 air and surface explosions. Origin time, coordinates, magnitudes mpv, MLV and energy class K were determined for explosions. A regional travel-time curve for Central Kazakhstan constructed using records of calibration chemical explosions conducted at the STS in 1997-2000 and ground-truth underground nuclear explosions was used to determine kinematic parameters of explosions. MLV, mpv, and energy class K were determined for all underground nuclear explosions conducted at the STS using historical seismograms from Central Asia stations. Dependencies of regional magnitudes on yield were received for air and underground nuclear explosions. Thus, application of historical seismograms at regional distances allows to recover and replenish the seismic catalogues of past nuclear explosions for further use in scientific investigations and monitoring tasks.

Sokolova, Inna

2014-05-01

61

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes  

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 characlip 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)

62

Human CD1d knock-in mouse model demonstrates potent antitumor potential of human CD1d-restricted invariant natural killer T cells  

OpenAIRE

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

63

Well logging apparatus and method: synthetic logs and synthetic seismograms with extrapolated reflector dip from log measurements  

International Nuclear Information System (INIS)

A borehole investigating device takes measurements of a subsurface earth formation and provides signals forming sonic, formation density or similar logs of the borehole. Additionally, the investigating device measures the dip of seismic signal reflectors traversed by the borehole and provides corresponding dip signals. A seismic section which may or may not include the borehole is selected, and the log and dip signals are combined with signals defining the location of the seismic section with respect to the borehole, to thereby provide synthetic logs for each of a number of virtual boreholes which coincide with selected virtual and/or actual shotpoints of the seismic section. The synthetic log signals are then combined to form a truly twodimensional synthetic seismogram for the selected seismic section. The synthetically derived signals may be corrected in accordance with a selected geological model of the formation

64

Synthetic seismograms in transversely isotropic plane layered media; Sismogrammes synthetiques dans les milieux stratifies presentant une isotropie plane  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the work presented in the paper, is to compute the response of transversely isotropic plane layered media excited by a buried or surface source, in order to obtain a method which can help interpreting real seismograms. The computation in frequency f and wavenumber k domain based on the Kennett`s reflectivity method is exposed. Displacements in space and time are calculated by numerical integration (Fourier-Hankel transform) of the response in frequency and wavenumber domain. The numerical surface response of a transverse isotropic two-layered half space excited by a surface source is presented. The mechanical properties of the proposed two-layered half-space falls within the range of marine sediments. The frequency and offset proposed domain correspond with geotechnical surveys. Effects of anisotropy are put forward by comparing the responses in anisotropy case to the responses in isotropic case. (author) 18 refs.

Guennou, C. [Universite de Bretagne Occidentale, 29 - Brest (France)

1998-09-01

65

Study of the 11th July, 1915, Portuguese offshore earthquake, in the Atlantic from contemporary seismograms and bulletins  

Science.gov (United States)

The seismicity rate in the contact of the Nubian and Euro-Asiatic plates along the Azores-Gibraltar region can be considered moderate. Nevertheless, large earthquakes do occur, as is well known from historical records. The sensibility of seismographic networks to earthquakes with oceanic origin has been extremely low until recent times. Oceanic M5 earthquakes have not been consistently recorded up to the second third of the XX century, precluding a proper knowledge of seismicity rates and other parameters of interest for earthquake hazard. Nevertheless, information for some events does exist, most of which remains to be properly studied. In this paper we analyze historical data for the 11th July, 1915 earthquake, which occurred offshore and was felt over the whole mainland Portugal. This event is one of the largest occurred during the instrumental period in the region of diffuse seismicity around the Gorringe bank. However it has been little studied, probably because it did not cause serious damage. The 11th July, 1915 earthquake is of great interest due to its size, estimated on the order of M6, and to its unique location with respect to the regions of large earthquakes in the Atlantic. In this paper, we present source parameters for this earthquake based on the analysis of the available contemporary seismograms and related documents. After throughout collection and selection, 23 seismograms obtained at 11 different European stations were digitized and processed. The event was relocated and its magnitude recalculated. Its focal mechanism has also been studied through waveform modeling and first motion polarity. We present the results of this analysis, compare the source of the 1915 earthquake with that of present earthquakes in the same region, and interpret the new results in light of the regional seismicity and seismo-tectonics.

Batllo-Ortiz, J.; Custodio, S.; Macia, R.; Teves-Costa, P.

2012-12-01

66

IMPROVEMENTS OF RIVER MODELING 1D DATA PREPARATION  

Directory of Open Access Journals (Sweden)

Full Text Available Improvements of river modeling 1D data preparation. The importance of hydrographical networks data and the need for detailed studies do generate an increase of projects in this specialized area and a diversification of river mathematical modeling software. River mathematical modeling can be done in two ways, namely; the "2D mode" and the “1D mode”. The “2D mode” is where a digital terrain model of a full hydrographical basin must be produced and "1D mode" is where only cross sections, long sections and structures elevations needs to be presented in a graphical environment and in a specific formats for the mathematical modeling software. This paper will show the principle of a custom built GIS, specially created to help the preparation of 1D river modeling data. The benefits are; elimination of human errors, automated processing, increasing productivity, flexible output and cost reduction.

ION-MARIAN MOISOIU

2012-11-01

67

Coal-seismic, desktop computer programs in BASIC; Part 5, Perform X-square T-square analysis and plot normal moveout lines on seismogram overlay  

Science.gov (United States)

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

68

Detection and identification of sources of very distant seismic events in Western United States using single array seismograms  

International Nuclear Information System (INIS)

In search of a new source discriminant based on the characteristics of PP signal, a study has been made by special further processing of Gauribidanur array (GBA) seismograms of underground explosions at Nevada Test Site (NTS) in Southern Nevada and of tectonic earthquakes in five provinces in the Western United States (US), both class of events being situated in the far teleseismic distance range (120deg

69

Two extensions of 1D Toda hierarchy  

CERN Document Server

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

70

Two extensions of 1D Toda hierarchy  

International Nuclear Information System (INIS)

The extended Toda hierarchy of Carlet, Dubrovin and Zhang is reconsidered in 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.

71

Integrable 1D Toda cellular automata  

CERN Document Server

First, we recall the algebro-geometric method of construction finite field valued solutions of the discrete KP equation and next we perform a reduction of dKP to the 1D Toda equation. It gives a method of construction of solutions of the 1D Toda equation taking values in a finite field.

Bialecki, M

2005-01-01

72

Running On-Demand Strong Ground Motion Simulations with the Second-Generation Broadband Platform  

Science.gov (United States)

We have developed the second-generation Southern California Earthquake Center (SCEC) Broadband Platform by integrating scientific modeling codes into a system capable of computing broadband seismograms (0-10 Hz) for historical and scenario earthquakes in California. The SCEC Broadband Platform is a collaborative software development project involving SCEC researchers, graduate students, and the SCEC Community Modeling Environment (SCEC/CME) software development group. SCEC scientific groups have contributed software modules to the Broadband Platform including rupture generation, low-frequency deterministic seismogram synthesis, high-frequency stochastic seismogram synthesis, and non-linear site effects. These complex scientific codes have been integrated into a system that supports easy on-demand computation of broadband seismograms. The SCEC Broadband Platform is designed to be used by both scientific and engineering researchers familiar with ground motion simulations. Users may calculate broadband seismograms for both historical earthquakes (validation events including Northridge, Loma Prieta, and Landers) and user-defined earthquakes. Users may select among various codebases for rupture generation, low-frequency synthesis, high-frequency synthesis, and incorporation of site effects, with the option of running a goodness-of-fit comparison against observed or simulated seismograms. The platform produces a variety of data products, including broadband seismograms, rupture visualizations, and goodness-of-fit plots. The Broadband Platform was implemented using software development best practices that support software accuracy, reliability, and ease of use, including version control, user documentation, acceptance tests, and formal software releases. Users can install the platform on their own machine, verify that it is installed correctly, and run their own simulations on demand. The Broadband Platform enables users to run complex ground motion modeling codes without detailed knowledge about how the codes are implemented. Users may run a validation event, supply their own simple source description, or provide a rupture description in Standard Rupture Format (SRF). Users may specify their own list of stations or use a provided list. Currently the platform supports stations and events in Southern California, the Bay Area, and the Mojave. In our poster, we will discuss the scientific capabilities of the Broadband Platform. We will describe the software engineering behind the platform development and the rigorous release procedure involved. Additionally, we will present simulations performed using the platform, including goodness-of-fit results, and discuss potential applications of on-demand broadband seismogram computation.

Callaghan, S.; Maechling, P. J.; Graves, R. W.; Somerville, P. G.; Collins, N.; Olsen, K. B.; Imperatori, W.; Jones, M.; Archuleta, R. J.; Schmedes, J.; Jordan, T. H.; Broadband Platform Working Group

2010-12-01

73

Synthetic seismograms in laterrally heterogeneous anelastic media: Modal summation for the case of offshore seismic sources (deep-sea trough)  

International Nuclear Information System (INIS)

While waiting for the increment of strong motion data, especially for earthquake prone areas outside the United States and Japan, a very useful approach to perform immediate site specific seismic hazard assessment is the development and use of modelling tools. They are based, on one hand, on the theoretical knowledge of the physics of the seismic source and of wave propagation and, on the other hand, on the exploitation of the relatively rich database, already available, that can be used for the definition of the source and structural models. With these input data we model the ground motion using the mode-coupling approach for sharply varying laterally heterogeneous anelastic media, i.e. computing the coupling coefficients for the modes transmitted and reflected at the vertical interface, between two quarter spaces in welded contact. The formalism can be readily applied to any laterally heterogeneous structure by using a custom series of layered anelastic structures in welded contact at vertical interfaces. The case of seismic wave propagation in smooth varying laterally heterogeneous layered media, is solved with an approximation, equivalent to WKBJ method. The theoretical formulation that combines both WKBJ and the coupling coefficients approaches, is implemented in a computer program package. The computer code we have developed allows us to calculate synthetic seismograms for a wide range of laterally inhomogeneous layered anelastic media. As a case study we use an earthquake which occurred on December 16, 1999 (mb=4.8) beneath the Bartlett sea trough, south of Santiago de Cuba city, that was recorded by an accelerometer (SMA-100) placed in Rio Carpintero (RCC) station, at an epicentral distance of about 30 Km. The path travelled by the waves corresponds to a complex structure from undersea source to inland seismic station. A good fit between the observed transverse component (SH-waves) of acceleration and the corresponding synthetic signal is obtained for a seismic moment of M0-7,1.1022. (author)

74

Ig-like transcript 4 inhibits lipid antigen presentation through direct CD1d interaction.  

OpenAIRE

NKT cells recognize lipid Ags presented by CD1d molecules and play an important role in the regulation of innate and adaptive immune responses. In this study, we report the identification of a membrane-associated protein, Ig-like transcript 4 (ILT4), as a novel human CD1d receptor that inhibits CD1d-mediated immune responses. We found that native CD1d tetramer generated by mammalian cells was able to specifically bind human monocytes in the peripheral blood, and this binding was at least part...

Li, D.; Wang, L.; Yu, L.; Freundt, Ec; Jin, B.; Screaton, GR; Xu, Xn

2009-01-01

75

Synthetic Seismograms in Transversely Isotropic Plane Layered Media Sismogrammes synthétiques dans les milieux stratifiés présentant une isotropie plane  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of the work presented in the paper, is to compute the response of transversely isotropic plane layered media excited by a buried or surface source, in order to obtain a method which can help interpreting real seismograms. The computation in frequency f and wavenumber k domain based on the Kennett's reflectivity method is exposed. Displacements in space and time are calculated by numerical integration (Fourier-Hankel transform of the response in frequency and wavenumber domain. The numerical surface response of a transverse isotropic two-layered half space excited by a surface source is presented. The mechanical properties of the proposed two-layered halfspace falls within the range of marine sediments. The frequency and offset proposed domain correspond with geotechnical surveys. Effects of anisotropy are put forward by comparing the responses in anisotropic case to the responses in isotropic case. Le but des présents travaux est de calculer la réponse des milieux stratifiés présentant une isotropie plane à l'excitation d'une source enterrée ou de surface, de façon à obtenir une méthode qui puisse aider à l'interprétation des sismogrammes réels. Le calcul exposé ici, dans un domaine de fréquence f et de nombre d'onde k, est basé sur la méthode de réflexion de Kennett. Les déplacements dans l'espace et dans le temps sont calculés par une intégration numérique (transformée de Fourier-Hankel de la réponse en fréquence et en nombre d'onde. La réponse numérique de surface d'un demi-espace à isotropie plane et à deux marqueurs excités par une source de surface est ici présentée. Les propriétés mécaniques du demi-espace proposé correspondent à celles de la gamme des sédiments marins. La fréquence et le décalage du domaine proposé correspondent à ceux employés dans la prospection géotechnique. Les effets de l'anisotropie sont mis en avant en comparant les réponses de l'exemple anisotrope à celles de l'exemple isotrope.

Guennou C.

2006-12-01

76

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

77

Synthetic seismograms from vibracores: A case study in correlating the late quaternary seismic stratigraphy of the New Jersey inner continental shelf  

Science.gov (United States)

A new technique, using empirical relationships between median grain size and density and velocity to calculate proxy values for density and velocity, avoids many of the problems associated with the use of well logs and shipboard measurements to construct synthetic seismograms. This method was used to groundtruth and correlate across both analog and digital shallow high-resolution seismic data on the New Jersey shelf. Sampling dry vibracores to determine median grain size eliminates the detrimental effects that coring disturbances and preservation variables have on the sediment and water content of the core. The link between seismic response to lithology and bed spacing is more exact. The exact frequency of the field seismic data can be realistically simulated by a 10-20 cm sampling interval of the vibracores. The estimate of the percentage error inherent in this technique, 12% for acoustic impedance and 24% for reflection amplitude, is calculated to one standard deviation and is within a reasonable limit for such a procedure. The synthetic seismograms of two cores, 4-6 m long, were used to correlate specific sedimentary deposits to specific seismic reflection responses. Because this technique is applicable to unconsolidated sediments, it is ideal for upper Pleistocene and Holocene strata. Copyright ?? 1996, SEPM (Society for Sedimentary Geology).

Esker, D.; Sheridan, R.E.; Ashley, G.M.; Waldner, J.S.; Hall, D.W.

1996-01-01

78

The LONG1D simulation code  

International Nuclear Information System (INIS)

LONG1D is a tracking programme for the study of longitudinal dynamics in proton synchrotrons, in the presence of space charge. The model considers only motion along the beam axis. The beam is represented by an ensemble of macro-particles, tracked in parallel. LONG1D has a variety of ensembles available, as appropriate to coasting and bunched beams. It allows for the injection of additional particles to facilitate phase-space painting studies. LONG1D can simulate the effect of radial and phase damping loops, and provides estimates of transverse incoherent betatron tune-shifts. This paper presents the physics algorithms used and some simulation results, and comparison with experimental observations. (Author) (10 refs., 2 figs.)

79

1-D equations of radiation hydrodynamics  

International Nuclear Information System (INIS)

The radiation transfer equation is derived in the comoving frame, in curvilinear coordinates, to first order in u/c, no symmetry being assumed. This equation is then specialized to 1-D, and its moments are calculated for the limiting case of Thomson scattering. The equations of radiation hydrodynamics are also given

80

1D WCIP and FEM hybridization  

OpenAIRE

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.

Girard, Caroline; Raveu, Nathalie; Perrussel, Ronan; Li, Jia; Lanteri, Ste?phane

2012-01-01

81

Preparation of 1D nanostructures using biomolecules  

Energy Technology Data Exchange (ETDEWEB)

In this paper we have shown that one-dimensional (1D) particle arrays can be obtained using biomolecules, like DNA or amino-acids. Nano-arrays of silver and gold were prepared in a single-step synthesis, by exploiting the binding abilities of {lambda}-DNA and L-Arginine. The morphology and optical properties of these nanostructures were investigated using AFM, TEM and UV-Vis absorption spectroscopy.

Pruneanu, Stela; Olenic, Liliana; Kacso, Irina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Tudoran, Lucian Barbu [Babes-Bolyai University, Electron Microscopy Center, 1 Mihail Kogalniceanu, 400006 Cluj-Napoca (Romania); Al-Said, Said A Farha; Hassanien, Reda; Houlton, Andrew; Horrocks, Benjamin R, E-mail: stela.pruneanu@itim-cj.r [School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

2009-08-01

82

Wave Propagation in 1-D Spiral geometry  

CERN Document Server

In this article, we investigate the wave equation in spiral geometry and study the modes of vibrations of a one-dimensional (1-D) string in spiral shape. Here we show that the problem of wave propagation along a spiral can be reduced to Bessel differential equation and hence, very closely related to the problem of radial waves of two-dimensional (2-D) vibrating membrane in circular geometry.

Chatterjee, Deep

2014-01-01

83

Preparation of 1D nanostructures using biomolecules  

International Nuclear Information System (INIS)

In this paper we have shown that one-dimensional (1D) particle arrays can be obtained using biomolecules, like DNA or amino-acids. Nano-arrays of silver and gold were prepared in a single-step synthesis, by exploiting the binding abilities of ?-DNA and L-Arginine. The morphology and optical properties of these nanostructures were investigated using AFM, TEM and UV-Vis absorption spectroscopy.

84

Finite thermal conductivity in 1D lattices  

OpenAIRE

We discuss the thermal conductivity of a chain of coupled rotators, showing that it is the first example of a 1d nonlinear lattice exhibiting normal transport properties in the absence of an on-site potential. Numerical estimates obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. Th...

Giardina?, C.; Livi, R.; Politi, A.; Vassalli, M.

2000-01-01

85

Hu1D10 induces apoptosis concurrent with activation of the AKT survival pathway in human chronic lymphocytic leukemia cells.  

Science.gov (United States)

The 1D10 antigen is the target for Hu1D10 (apolizumab), a humanized HLA-DR beta-chain-specific antibody that is currently in clinical trials for hematologic malignancies. We demonstrate that Hu1D10 induces caspase-independent apoptosis following secondary cross-linking in primary chronic lymphocytic leukemia (CLL) cells. Generation of reactive oxygen species (ROS) and signal transduction, as evidenced by phosphorylation of Syk and AKT, were noted. The source of the Hu1D10-induced ROS was examined using the Raji lymphoblastic cell line with engineered defects in the mitochondrial respiratory chain. Hu1D10 treatment of clones with deficient mitochondrial respiration produced ROS suggesting a cytoplasmic source. Administration of ROS scavengers to primary CLL cells prior to Hu1D10 treatment diminished AKT activation. Treatment with Hu1D10 and the phosphatidylinositol 3-kinase inhibitor LY294002 demonstrated in vitro synergy with enhanced apoptosis. In conjunction with an ongoing clinical trial, blood samples were collected following intravenous infusion of Hu1D10 and analyzed for phosphorylation of AKT. Two of 3 patient samples showed a sustained increase in AKT phosphorylation following Hu1D10 administration. These data suggest that Hu1D10 ligation in CLL cells induces death and survival signals for which combination therapies may be designed to greatly enhance efficiency of both Hu1D10 and other class II antibodies in development. PMID:14630799

Mone, Andrew P; Huang, Peng; Pelicano, Helene; Cheney, Carolyn M; Green, Jennifer M; Tso, J Yun; Johnson, Amy J; Jefferson, Sara; Lin, Thomas S; Byrd, John C

2004-03-01

86

Coalescence phenomena in 1D silver nanostructures  

International Nuclear Information System (INIS)

Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reaction in ethylene glycol at 160 deg. C were studied experimentally and theoretically. Analysis by TEM and HRTEM shows different defects found on the body of these materials, suggesting that they were induced by previous coalescence processes in the synthesis stage. TEM observations showed that irradiation with the electron beam eliminates the boundaries formed near the edges of the structures, suggesting that this process can be carried out by the application of other means of energy (i.e. thermal). These results were also confirmed by theoretical calculations by Monte Carlo simulations using a Sutton-Chen potential. A theoretical study by molecular dynamics simulation of the different coalescence processes on 1D silver nanostructures is presented, showing a surface energy driven sequence followed to form the final coalesced structure. Calculations were made at 1000-1300 K, which is near the melting temperature of silver (1234 K). Based on these results, it is proposed that 1D nanostructures can grow through a secondary mechanism based on coalescence, without losing their dimensionality.

87

Chaos in 1d edge plasmas  

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 ronary problem) rediscovers the known routes to chaos in spatial extension like period doubling or intermittence. (orig.)

88

Effects of 1-D versus 3-D velocity models on moment tensor inversion in the Dobrá Voda area in the Little Carpathians region, Slovakia  

Science.gov (United States)

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

89

Immunoglobulin-like Transcript 4 (ILT4) Inhibits Lipid Antigen Presentation through Direct CD1d Interaction1  

OpenAIRE

Natural killer T (NKT) cells recognize lipid antigens presented by CD1d molecules and play an important role in the regulation of innate and adaptive immune responses. Here we report the identification of a membrane-associated protein, immunoglobulin-like transcript 4 (ILT4), as a novel human CD1d receptor that inhibits CD1d-mediated immune responses. We found that native CD1d tetramer generated by mammalian cells was able to specifically bind human monocytes in the peripheral blood, and this...

Li, Demin; Wang, Lili; Yu, Li; Freundt, Eric C.; Jin, Boquan; Screaton, Gavin R.; Xu, Xiao-ning

2009-01-01

90

CD1d presentation of glycolipids.  

OpenAIRE

The CD1 family of antigen-presenting molecules consists of five members, CD1a to e. Of these molecules CD1d has been the subject of much interest over the past 10 years following the discovery that this molecule presents antigens to a group of T cells known as invariant natural killer T cells (iNKT). iNKT cells carry an invariant T cell receptor which contains homologous gene segments in mouse and man. iNKT cells are positively selected in the thymus in the same manner as major histocompatibi...

Speak, Ao; Cerundolo, V.; Platt, Fm

2008-01-01

91

Finite thermal conductivity in 1d lattices  

CERN Document Server

We discuss the thermal conductivity of a chain of coupled rotators, showing that it is the first example of a 1d nonlinear lattice exhibiting normal transport properties in the absence of an on-site potential. Numerical estimates obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of this model.

Giardinà, C; Politi, A; Vassalli, M

2000-01-01

92

CIW exam 1D0-470  

CERN Document Server

Here''s the book you need to prepare for Exam 1D0-470, CIW Security Professional. This Study Guide provides:In-depth coverage of official exam objectivesPractical information on security concepts and practicesHundreds of challenging review questions, in the book and on the CDLeading-edge exam preparation software, including a testing engine and electronic flashcards Authoritative coverage of all exam topics, including:Implementing internetworking encryption and encryption methodsAnalyzing firewall types and firewall terminologyPlanning security systems and incorporating multiple levels of prot

Stanger, James; Crothers, Tim

2006-01-01

93

Blood flow quantification using 1D CFD parameter identification  

Science.gov (United States)

Patient-specific measurements of cerebral blood flow provide valuable diagnostic information concerning cerebrovascular diseases rather than visually driven qualitative evaluation. In this paper, we present a quantitative method to estimate blood flow parameters with high temporal resolution from digital subtraction angiography (DSA) image sequences. Using a 3D DSA dataset and a 2D+t DSA sequence, the proposed algorithm employs a 1D Computational Fluid Dynamics (CFD) model for estimation of time-dependent flow values along a cerebral vessel, combined with an additional Advection Diffusion Equation (ADE) for contrast agent propagation. The CFD system, followed by the ADE, is solved with a finite volume approximation, which ensures the conservation of mass. Instead of defining a new imaging protocol to obtain relevant data, our cost function optimizes the bolus arrival time (BAT) of the contrast agent in 2D+t DSA sequences. The visual determination of BAT is common clinical practice and can be easily derived from and be compared to values, generated by a 1D-CFD simulation. Using this strategy, we ensure that our proposed method fits best to clinical practice and does not require any changes to the medical work flow. Synthetic experiments show that the recovered flow estimates match the ground truth values with less than 12% error in the mean flow rates.

Brosig, Richard; Kowarschik, Markus; Maday, Peter; Katouzian, Amin; Demirci, Stefanie; Navab, Nassir

2014-03-01

94

Inverting full waveforms into 1D seismic (upper) crustal model by Neighborhood Algorithm: example from the Corinth Gulf, Greece  

Science.gov (United States)

Constructing seismic models of the Earth crust serves two major purposes: (i) helping to understand a geologic structure, and (ii) enabling investigations of earthquakes in terms of their location, centroid-moment-tensors, and/or slip-history on faults. We follow line (ii) where even good 1D models are still important. Should the 1D models be usable in seismic waveform modeling, the natural way is to derive them from full waveforms. We developed and tested a method in which full waveforms of an earthquake recorded in a network of local-to-regional stations are inverted into a 1D crustal model, optimally representing the seismic wave propagation. A single-point source approximation is used. The hypocenter position, origin time and a double-couple focal mechanism are fixed at previously determined values. The forward problem is solved by the Discrete Wavenumber method (Bouchon, 1981; Coutant 1989). The inverse problem is solved by the Neighborhood Algorithm (Sambridge, 1999), providing a suite of the well-fitting velocity models. The misfit function is the L2 norm of the difference between the observed and synthetic seismograms. The performance of the method is illustrated on the largest event (Mw 5.3) of the 2010 Efpalio earthquake sequence, Greece (Sokos et al., 2012). Broad-band data at 8 stations are used, spanning epicentral distances from 13 to 100 km. Several different parametrizations are tested. The most interesting results are obtained in the frequency range of 0.05-0.20 Hz for varying 7 layer thicknesses, their Vp and Vs. The corresponding waveform match (variance reduction VR~0.6) is significantly better than with the previously existing models of the region. It strengthens a chance to study some details of the space-time rupture process of future significant events in the Corinth Gulf. As revealed by the correlation and covariance matrices, the mutual trade-off between the thicknesses and velocities, as well as between Vp and Vs is negligible. The resolution decreases with depth. The best resolved is a significant Vs increase in the topmost 4 km; the Vp/Vs ratio in this layer is as large as ~2 - 2.5. Several path-dependent (single-station) 1D models were also constructed whose main importance was the stability check. Investigation of lateral crustal variations would require more earthquakes.

Plicka, Vladimir; Zahradnik, Jiri

2013-04-01

95

MineSeis -- A MATLAB{reg_sign} GUI program to calculate synthetic seismograms from a linear, multi-shot blast source model  

Energy Technology Data Exchange (ETDEWEB)

Large scale (up to 5 kt) chemical blasts are routinely conducted by mining and quarry industries around the world to remove overburden or to fragment rocks. Because of their ability to trigger the future International Monitoring System (IMS) of the Comprehensive Test Ban Treaty (CTBT), these blasts are monitored and studied by verification seismologists for the purpose of discriminating them from possible clandestine nuclear tests. One important component of these studies is the modeling of ground motions from these blasts with theoretical and empirical source models. The modeling exercises provide physical bases to regional discriminants and help to explain the observed signal characteristics. The program MineSeis has been developed to implement the synthetic seismogram modeling of multi-shot blast sources with the linear superposition of single shot sources. Single shot sources used in the modeling are the spherical explosion plus spall model mentioned here. Mueller and Murphy`s (1971) model is used as the spherical explosion model. A modification of Anandakrishnan et al.`s (1997) spall model is developed for the spall component. The program is implemented with the MATLAB{reg_sign} Graphical User Interface (GUI), providing the user with easy, interactive control of the calculation.

Yang, X.

1998-04-01

96

Concentric mosaic(s), planar motion and 1D cameras  

OpenAIRE

General SFM methods give poor results for images captured by constrained motions such as planar motion of concentric mosaics (CM). In this paper, we propose new SFM algorithms for both images captured by CM and composite mosaic images from CM. We first introduce 1D affine camera model for completing 1D camera models. Then we show that a 2D image captured by CM can be decoupled into two 1D images: one 1D projective and one 1D affine; a composite mosaic image can by rebinned into a calibrated 1...

Quan, Long; Lu, Le; Shum, Harry; Lhuillier, Maxime

2001-01-01

97

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

98

Targeted disruption of Tbc1d20 with zinc-finger nucleases causes cataracts and testicular abnormalities in mice.  

Science.gov (United States)

BackgroundLoss-of-function mutations in TBC1D20 cause Warburg Micro syndrome 4 (WARBM4), which is an autosomal recessive syndromic disorder characterized by eye, brain, and genital abnormalities. Blind sterile (bs) mice carry a Tbc1d20-null mutation and exhibit cataracts and testicular phenotypes similar to those observed in WARBM4 patients. In addition to TBC1D20, mutations in RAB3GAP1, RAB3GAP2 and RAB18 cause WARBM1-3 respectively. However, regardless of which gene harbors the causative mutation, all individuals affected with WARBM exhibit indistinguishable clinical presentations. In contrast, bs, Rab3gap1 -/- , and Rab18 -/- mice exhibit distinct phenotypes; this phenotypic variability of WARBM mice was previously attributed to potential compensatory mechanisms. Rab3gap1 -/- and Rab18 -/- mice were genetically engineered using standard approaches, whereas the Tbc1d20 mutation in the bs mice arose spontaneously. There is the possibility that another unidentified mutation within the bs linkage disequilibrium may be contributing to the bs phenotypes and thus contributing to the phenotypic variability in WARBM mice. The goal of this study was to establish the phenotypic consequences in mice caused by the disruption of the Tbc1d20 gene.ResultsThe zinc finger nuclease (ZFN) mediated genomic editing generated a Tbc1d20 c.[418_426del] deletion encoding a putative TBC1D20-ZFN protein with an in-frame p.[H140_Y143del] deletion within the highly conserved TBC domain. The evaluation of Tbc1d20 ZFN/ZFN eyes identified severe cataracts and thickened pupillary sphincter muscle. Tbc1d20 ZFN/ZFN males are infertile and the analysis of the seminiferous tubules identified disrupted acrosomal development. The compound heterozygote Tbc1d20 ZFN/bs mice, generated from an allelic bs/+ X Tbc1d20 ZFN/+ cross, exhibited cataracts and aberrant acrosomal development indicating a failure to complement.ConclusionsOur findings show that the disruption of Tbc1d20 in mice results in cataracts and aberrant acrosomal formation, thus establishing bs and Tbc1d20 ZFN/ZFN as allelic variants. Although the WARBM molecular disease etiology remains unclear, both the bs and Tbc1d20 ZFN/ZFN mice are excellent model organisms for future studies to establish TBC1D20-mediated molecular and cellular functions. PMID:25476608

Park, Anna; Liegel, Ryan P; Ronchetti, Adam; Ebert, Allison D; Geurts, Aron; Sidjanin, Duska J

2014-12-01

99

Design and Implementation of a 1-D Multi-Scroll Chaotic Circuit Based on CFOAs  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, a method is proposed to design a one-dimensional (1-D multi-scroll chaotic circuit by using Current Feedback Operational Amplifiers (CFOAs. A chaotic circuit is designed which consists of three integrators and one nonlinear circuit. The circuit can generate 1-D multi-scroll chaotic attractors. The central frequency of the circuit is higher with fewer active devices and simpler circuit construction. Numeral simulation, circuit simulation experiments are performed and results show that the method is feasible and circuit design is correct.

Xianming Wu

2014-01-01

100

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 e 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

101

Using Borehole Vertical Array Data to Determine Local Attenuation and Velocity Structure: A Combined Global-Local Optimization Algorithm for Plane Wave Seismogram Inversion  

Science.gov (United States)

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

102

Role for lysosomal phospholipase A2 in iNKT cell-mediated CD1d recognition  

OpenAIRE

Invariant natural killer T (iNKT) cells recognize self lipid antigens presented by CD1d molecules. The nature of the self-antigens involved in the development and maturation of iNKT cells is poorly defined. Lysophospholipids are self-antigens presented by CD1d that are generated through the action of phospholipases A1 and A2. Lysosomal phospholipase A2 (LPLA2, group XV phospholipase A2) resides in the endocytic system, the main site where CD1d antigen acquisition occurs, suggesting that it co...

Paduraru, Crina; Bezbradica, Jelena S.; Kunte, Amit; Kelly, Robert; Shayman, James A.; Veerapen, Natacha; Cox, Liam R.; Besra, Gurdyal S.; Cresswell, Peter

2013-01-01

103

Preferential elimination of chromosome 1D from homoeologous group-1 alien addition lines in hexaploid wheat.  

Science.gov (United States)

Alien chromosome addition lines are useful genetic material for studying the effect of an individual chromosome in the same genetic background. However, addition lines are sometimes unstable and tend to lose the alien chromosome in subsequent generations. In this study, we report preferential removal of chromosome 1D rather than the alien chromosome from homoeologous group-1 addition lines. The Agropyron intermedium chromosome 1Agi (1E) addition line, created in the background of 'Vilmorin 27', showed loss of a part of chromosome 1D, thereby losing its HMW glutenin locus. Even in the case of Aegilops longissima and Ae. peregrina, the genomes of which are closer to the B genome than D genome, chromosome 1D was lost from chromosome 1Sl and 1Sv addition lines in cv. 'Chinese Spring' rather than chromosome 1B during transfer from one generation to another. A similar observation was also observed in the case of a chromosome 1E disomic addition line of Ag. elongatum and alloplasmic common wheat line with Ag. intermedium ssp. trichophorum cytoplasm. The reason for this strange observation is thought to lie in the history of wheat evolution, the size of chromosome 1D compared to 1A and 1B, or differing pollen competition abilities. PMID:17991995

Garg, Monika; Elamein, Hala M M; Tanaka, Hiroyuki; Tsujimoto, Hisashi

2007-10-01

104

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

OpenAIRE

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

105

New Scotogenic Model of Neutrino Mass with $U(1)_D$ Gauge Interaction  

OpenAIRE

We propose a new realization of the one-loop radiative model of neutrino mass generated by dark matter (scotogenic), where the particles in the loop have an additional $U(1)_D$ gauge symmetry, which may be exact or broken to $Z_2$. This model is relevant to a number of astrophysical observations, including AMS-02 and the dark matter distribution in dwarf galactic halos.

Ma, Ernest; Picek, Ivica; Radovcic, Branimir

2013-01-01

106

New scotogenic model of neutrino mass with U(1)D gauge interaction  

International Nuclear Information System (INIS)

We propose a new realization of the one-loop radiative model of neutrino mass generated by dark matter (scotogenic), where the particles in the loop have an additional U(1)D gauge symmetry, which may be exact or broken to Z2. This model is relevant to a number of astrophysical observations, including AMS-02 and the dark-matter distribution in dwarf galactic halos

107

From nonfinite to finite 1D arrays of origami tiles.  

Science.gov (United States)

CONSPECTUS: DNA based nanotechnology provides a basis for high-resolution fabrication of objects almost without physical size limitations. However, the pathway to large-scale production of large objects is currently unclear. Operationally, one method forward is to use high information content, large building blocks, which can be generated with high yield and reproducibility. Although flat DNA origami naturally invites comparison to pixels in zero, one, and two dimensions and voxels in three dimensions and has provided an excellent mechanism for generating blocks of significant size and complexity and a multitude of shapes, the field is young enough that a single "brick" has not become the standard platform used by the majority of researchers in the field. In this Account, we highlight factors we considered that led to our adoption of a cross-shaped, non-space-filling origami species, designed by Dr. Liu of the Seeman laboratory, as the building block ideal for use in the fabrication of finite one-dimensional arrays. Three approaches that can be employed for uniquely coding origami-origami linkages are presented. Such coding not only provides the energetics for tethering the species but also uniquely designates the relative orientation of the origami building blocks. The strength of the coding approach implemented in our laboratory is demonstrated using examples of oligomers ranging from finite multimers composed of four, six, and eight origami structures to semi-infinite polymers (100mers). Two approaches to finite array design and the series of assembly steps that each requires are discussed. The process of AFM observation for array characterization is presented as a critical case study. For these soft species, the array images do not simply present the solution phase geometry projected onto a two-dimensional surface. There are additional perturbations associated with fluidic forces associated with sample preparation. At this time, reconstruction of the "true" or average solution structures for blocks is more readily achieved using computer models than using direct imaging methods. The development of scalable 1D-origami arrays composed of uniquely addressable components is a logical, if not necessary, step in the evolution of higher order fully addressable structures. Our research into the fabrication of arrays has led us to generate a listing of several important areas of future endeavor. Of high importance is the re-enforcement of the mechanical properties of the building blocks and the organization of multiple arrays on a surface of technological importance. While addressing this short list of barriers to progress will prove challenging, coherent development along each of these lines of inquiry will accelerate the appearance of commercial scale molecular manufacturing. PMID:24803094

Wu, Tsai Chin; Rahman, Masudur; Norton, Michael L

2014-06-17

108

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

International Nuclear Information System (INIS)

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)

109

T1D in School (Type 1 Diabetes)  

Science.gov (United States)

... About JDRF Life with T1D Get Involved Advocacy Research Grant Center Get ... School Advisory Toolkit This guide offers collaborative methods for educators and parents of children with diabetes ...

110

Main: 1D6R [RPSD[Archive  

Lifescience Database Archive (English)

Full Text Available 1D6R ?? Soybean Glycine max (L.) Merrill Bowman-Birk Type Proteinase Inhibitor Precursor Glyci ... Warkentin, G.Wenzl, P.Flecker Crystal Structure Of Cancer ... Chemopreventive Bowman-Birk Inhibitor In Ternary C ...

111

T1D in College (Type 1 Diabetes)  

Science.gov (United States)

... Stories › Quick Links Grant Center Info for Applicants Info for Awardees Industry Partnerships Also in this Section Updates and Announcements Funding Opportunities and Deadlines Additional Resources Contact Grant Staff JDRF About JDRF Life with T1D Get Involved ...

112

Dealing with a New T1D Diagnosis in College  

Science.gov (United States)

... Stories › Quick Links Grant Center Info for Applicants Info for Awardees Industry Partnerships Also in this Section Updates and Announcements Funding Opportunities and Deadlines Additional Resources Contact Grant Staff JDRF About JDRF Life with T1D Get Involved ...

113

Main: 1D8U [RPSD[Archive  

Lifescience Database Archive (English)

Full Text Available 1D8U ?? Rice Oryza sativa L. Non-Symbiotic Hemoglobin 1 Name=Hb1; Synonyms=Glb1a; Oryza Sativa ... C49883.1; -.|EMBL; U76029; AAC49882.1; -.|EMBL; AF335 504; AAK72229.1; -.|PIR; T04163; T04163.|PDB; 1D8U; ... PLANT_GLOBIN; 1. X-Ray Diffraction, Resolution: 2.35 ... Angstrom, R-Factor: 0.208, R-Free: 0.261 Length: 1 ...

114

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

CERN Document Server

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

115

A human serotonin 1D receptor variant (5HT1D beta) encoded by an intronless gene on chromosome 6.  

OpenAIRE

An intronless gene encoding a serotonin receptor (5HT1D beta) has been cloned and functionally expressed in mammalian fibroblast cultures. Based on the deduced amino acid sequence, the gene encodes a 390-amino acid protein displaying considerable homology, within putative transmembrane domains (approximately 75% identity) to the canine and human 5HT1D receptors. Membranes prepared from CHO cells stably expressing the receptor bound [3H]serotonin with high affinity (Kd 4 nM) and displayed a ph...

Demchyshyn, L.; Sunahara, R. K.; Miller, K.; Teitler, M.; Hoffman, B. J.; Kennedy, J. L.; Seeman, P.; Tol, H. H.; Niznik, H. B.

1992-01-01

116

A new 1D-multigroup-discrete ordinates algorithm for neutron transport  

International Nuclear Information System (INIS)

A variation of the multigroup SN method, called the MultiGroup Converged SM (MGCSN) method has been constructed to generate benchmark quality solutions to the 1D multigroup transport equation. The method is woven around two convergence accelerators that accelerate the convergence of sequences to their limits. The Romberh acceleration is well known to accelerate convergence of a discretized numerical scheme to a low discretization error. The Wynn-epsilon scheme is a Pade' approximant for a specially constructed series that has a desired limit. Romberg acceleration is applied to the 1D transport equation to reduce the spatial error; while, the Wynn-epsilon acceleration converges the solution in quadrature order. The MGCSN method is presented in detail and demonstrated for fixed source problems; however, its application to critical system is also demonstrated. (author)

117

N/D analysis of 1D2 diproton through coupled pp, ?+d and N? channels  

International Nuclear Information System (INIS)

Dinucleon resonance at pp (1D2) state is analysed by means of the three-channel N/D formalism with couplings among pp, pi d and N delta channels. The Glauber model amplitudes are used as an input to pi d elastic amplitude in addition to the input so far used such as the empirical pp elastic amplitude, etc. Most probable solution seems that Argand plots of both pp and pi d elastic amplitudes show local counterclockwise circles. The radius of Argand circle of pi d amplitude is larger than that of pp amplitude. Resultant amplitude of N delta elastic channel shows a possibility that 1D2 resonance is generated through an N delta bound state. (author)

118

GIS-BASED 1-D DIFFUSIVE WAVE OVERLAND FLOW MODEL  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a GIS-based 1-d distributed overland flow model and summarizes an application to simulate a flood event. The model estimates infiltration using the Green-Ampt approach and routes excess rainfall using the 1-d diffusive wave approximation. The model was designed to use readily available topographic, soils, and land use/land cover data and rainfall predictions from a meteorological model. An assessment of model performance was performed for a small catchment and a large watershed, both in urban environments. Simulated runoff hydrographs were compared to observations for a selected set of validation events. Results confirmed the model provides reasonable predictions in a short period of time.

KALYANAPU, ALFRED [Los Alamos National Laboratory; MCPHERSON, TIMOTHY N. [Los Alamos National Laboratory; BURIAN, STEVEN J. [NON LANL

2007-01-17

119

Flood hazard assessment using 1D and 2D approaches  

Science.gov (United States)

The EU flood risk Directive (Directive 2007/60/EC) prescribes risk assessment and mapping to develop flood risk management plans. Flood hazard mapping may be carried out with mathematical models able to determine flood-prone areas once realistic conditions (in terms of discharge or water levels) are imposed at the boundaries of the case study. The deterministic models are mainly based on shallow water equations expressed in their 1D or 2D formulation. The 1D approach is widely used, especially in technical studies, due to its relative simplicity, its computational efficiency and also because it requires topographical data not as expensive as the ones needed by 2D models. Even if in a great number of practical situations, such as modeling in-channel flows and not too wide floodplains, the 1D approach may provide results close to the prediction of a more sophisticated 2D model, it must be pointed out that the correct use of a 1D model in practical situations is more complex than it may seem. The main issues to be correctly modeled in a 1D approach are the definition of hydraulic structures such as bridges and buildings interacting with the flow and the treatment of the tributaries. Clearly all these aspects have to be taken into account also in the 2D modeling, but with fewer difficulties. The purpose of this paper is to show how the above cited issues can be described using a 1D or 2D unsteady flow modeling. In particular the Authors will show the devices that have to be implemented in 1D modeling to get reliable predictions of water levels and discharges comparable to the ones obtained using a 2D model. Attention will be focused on an actual river (Crati river) located in the South of Italy. This case study is quite complicated since it deals with the simulation of channeled flows, overbank flows, interactions with buildings, bridges and tributaries. Accurate techniques, intentionally developed by the Authors to take into account all these peculiarities in 1D and 2D modeling, will be presented, compared and discussed.

Petaccia, Gabriella; Costabile, Pierfranco; Macchione, Francesco; Natale, Luigi

2013-04-01

120

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 electricer, a comparison of the simulated electrical parameters with experimental results was performed.

121

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

Energy Technology Data Exchange (ETDEWEB)

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.

Barrera, Marcela, E-mail: barrera@tandar.cnea.gov.ar [Comision Nacional de Energia Atomica, Avenida General Paz 1499, San Martin 1650, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Rubinelli, Francisco [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC)-CONICET, Gueemes 3450, Santa Fe 3000 (Argentina); Rey-Stolle, Ignacio [Instituto de Energia Solar, Universidad Politecnica de Madrid, Avenida Complutense 30, Madrid 28040 (Spain); Pla, Juan [Comision Nacional de Energia Atomica, Avenida General Paz 1499, San Martin 1650, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)

2012-08-15

122

DYN1D-MSR dynamics code for molten salt reactors  

International Nuclear Information System (INIS)

This paper reports about the DYN1D-MSR code development and dynamics studies of the molten salt reactors (MSR) - one of the 'Generation IV International Forum' concepts. In this forum the graphite-moderated channel type MSR based on the previous Oak Ridge National Laboratory research is considered. The liquid molten salt serves as a fuel and coolant, simultaneously and causes two physical peculiarities: the fission energy is released predominantly directly into the coolant and the delayed neutrons precursors are drifted by the fuel flow. The drift causes the spread of delayed neutrons distribution to the non-core parts of primary circuit and it can lead to a reactivity loss or gain in the case of fuel flow acceleration or deceleration, respectively. Therefore, specific 3D tool based on in house code DYN3D was developed in FZR. The code DYN3D-MSR is based on the solution of two-group neutron diffusion equation by the help of a nodal expansion method and it includes models of delayed neutrons drift and specific MSR heat release distribution. In this paper the development and verification of 1D version DYN1D-MSR of the code is described. The code has been validated with the experimental data gained from the molten salt reactor experiment performed in the Oak Ridge and after the validation it was applied to several typical transients (overcooling of fuel at the core inlet, reactivity insertion, and the fuel pump trip)

123

Ultracold spherical horizons in gauged N=1, d=4 supergravity  

International Nuclear Information System (INIS)

We show that the near-horizon limit of ultracold magnetic Reissner-Nordstroem-De Sitter black holes, whose geometry is the direct product of 2-dimensional Minkowski spacetime and a 2-sphere, preserves half of the supersymmetries of minimal R-gauged N=1, d=4 supergravity.

124

Selected Topics in the Theory of 1D Quantum Wires  

OpenAIRE

Lecture given at the Landau Institute Seminar, Col de Port, March 1994, intended for a qualitative discussion of recent theoretical results in the physics of 1D quantum wires. The consideration is mainly focused on observable quantities, such as conductance, persistent current, and X-Ray response functions, which are discussed in simple terms.

Gogolin, Alexander O.

1994-01-01

125

A 1D wavelet filtering for ultrasound images despeckling  

Science.gov (United States)

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

126

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

127

Super resolution and spectral properties for 1D multilayer systems  

OpenAIRE

We investigate the spectral properties of one-dimensional multilayer structures for the two polarizations TE and TM. We give a physical explanation for the large spatial transmission band that can be obtained with this kind of system, and the correlated super resolution effect. We also suggest a designing approach to build 1D metal-dielectric multilayer structures that have super resolution.

Mandatori, A.; Bertolotti, M.

2009-01-01

128

KINE, 1-D PWR Dynamic with Partial Core Boiling  

International Nuclear Information System (INIS)

1 - Description of program or function: 1-D dynamics program for PWRs with partial boiling in the core. Solves time dependent diffusion equation for 2 prompt and 6 delayed neutron groups. 2 - Method of solution: Backward extrapolation technique. 3 - Restrictions on the complexity of the problem: 2 prompt and 6 delayed neutron groups, 200 local meshes

129

Ultrahigh sensitivity of Au/1D ?-Fe2O3 to acetone and the sensing mechanism.  

Science.gov (United States)

Hematite (?-Fe(2)O(3)) is a nontoxic, stable, versatile material that is widely used in catalysis and sensors. Its functionality in sensing organic molecules such as acetone is of great interest because it can result in potential medical applications. In this report, microwave irradiation is applied in the preparation of one-dimensional (1D) ?-FeOOH, thereby simplifying our previous hydrothermal method and reducing the reaction time to just a few minutes. Upon calcination, the sample was converted to porous ?-Fe(2)O(3) nanorods, which were then decorated homogeneously by fine Au particles, yielding Au/1D ?-Fe(2)O(3) at nominally 3 wt % Au. After calcination, the sample was tested as a potential sensor for acetone in the parts per million range and compared to a similarly loaded Pt sample and the pure 1D ?-Fe(2)O(3) support. Gold addition results in a much enhanced response whereas Pt confers little or no improvement. From tests on acetone in the 1-100 ppm range in humid air, Au/1D ?-Fe(2)O(3) has a fast response, short recovery time, and an almost linear response to the acetone concentration. The optimum working temperature was found to be 270 °C, which was judged to be a compromise between the thermal activation of lattice oxygen in hematite and the propensity for acetone adsorption. The surface reaction was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and a possible sensing mechanism is proposed. The presence of Au nanoparticles is believed to promote the dissociation of molecular oxygen better in replenishing O vacancies, thereby increasing the instantaneous supply of lattice oxygen to the oxidation of acetone (to H(2)O and CO(2)), which proceeds through an adsorbed acetate intermediate. This work contributes to the development of next-generation sensors, which offer ultrahigh detection capabilities for organic molecules. PMID:22950638

Gunawan, Poernomo; Mei, Lin; Teo, Jaclyn; Ma, Jianmin; Highfield, James; Li, Qiuhong; Zhong, Ziyi

2012-10-01

130

PPM1D is a prognostic marker and therapeutic target in colorectal cancer  

OpenAIRE

Protein phosphatase, Mg2+/Mn2+ dependent, 1D (PPM1D) has been associated with carcinogenesis. The present study investigated PPM1D expression as a potential biomarker in colorectal cancer (CRC). PPM1D expression was assessed using immunohistochemistry in 368 patients with CRC. The correlation between PPM1D expression, clinicopathological features and prognosis was analyzed. PPM1D small interfering (si)RNA-induced PPM1D silencing was performed in CRC cell lines to assess the effect of PPM1D on...

Peng, Tian-shu; He, Yong-heng; Nie, Tian; Hu, Xiang-dang; Lu, Hai-yan; Yi, Jian; Shuai, Yun-fei; Luo, Min

2014-01-01

131

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

Science.gov (United States)

...the failure of 2nd stage turbine blades, which could result...replacement of 2nd stage turbines on Arriel 1B, 1D, and...engine to replace the gas turbine discs [[Page 27412...substantial number of small entities under the...

2010-05-17

132

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

Science.gov (United States)

...position check of 2nd stage turbine blades on Arriel 1S1 engines...replacement of 2nd stage turbines on Arriel 1B, 1D, and...engine to replace the gas turbine discs and blades. The...substantial number of small entities under the...

2010-03-10

133

Molecular, Physicochemical and Rheological Characteristics of Introgressive Triticale/Triticum monococcum ssp. monococcum Lines with Wheat 1D/1A Chromosome Substitution  

OpenAIRE

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...

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

2013-01-01

134

Investigation of reflood models by coupling REFLA-1D and multi-loop system model  

International Nuclear Information System (INIS)

A system analysis code REFLA-1DS was developed by coupling reflood analysis code REFLA-1D and a multi-loop primary system model. The reflood models in the code were investigated for the development of the integral system analysis code. The REFLA-1D, which was developed with the small scale reflood experiment at JAERI, consists of one-dimensional core model and a primary system model with a constant loop resistance. The multi-loop primary system model was developed with the Cylindrical Core Test Facility of JAERI's large scale reflood tests. The components modeled in the code are the upper plenum, the steam generator, the coolant pump, the ECC injection port, the downcomer and the broken cold leg nozzle. The coupling between the two models in REFLA-1DS is accomplished by applying the equivalent flow resistance calculated with the multiloop model to the REFLA-1D. The characteristics of the code is its simplicity of the system model and the solution method which enables the fast running and the easy reflood analysis for the further model development. A fairly good agreement was obtained with the results of the Cylindrical Core Test Facility for the calculated water levels in the downcomer, the core and the upper plenum. A qualitatively good agreement was obtained concerning the parametric effects of the system pressure, the ECC flow rate and the initial clad temperature. Needs for further code improvements of the models, however, were pointed out. These include the problem concerning the generation rate of the steam and water droplets in the core in an early period, the effect of the flow oscillation on the core cooling, the heat release from the downcomer wall, and the stable system calculation. (author)

135

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

136

Geometry of D1-D5-P bound states  

International Nuclear Information System (INIS)

Supersymmetric solutions of 6D supergravity (with two translation symmetries) can be written as a hyper-Kahler base times a 2D fiber. The subset of these solutions which correspond to true bound states of D1-D5-P charges give microstates of the 3-charge extremal black hole. To understand the characteristics shared by the bound states we decompose known bound state geometries into base-fiber form. The axial symmetry of the solutions make the base Gibbons-Hawking. We find the base to be actually 'pseudo-hyper-Kahler': The signature changes from (4,0) to (0,4) across a hypersurface. 2-charge D1-D5 geometries are characterized by a 'central curve'S1; the analogue for 3-charge appears to be a hypersurface that for our metrics is an orbifold of S1xS3

137

1-D transforms for the motion compensation residual.  

Science.gov (United States)

Transforms used in image coding are also commonly used to compress prediction residuals in video coding. Prediction residuals have different spatial characteristics from images, and it is useful to develop transforms that are adapted to prediction residuals. In this paper, we explore the differences between the characteristics of images and motion compensated prediction residuals by analyzing their local anisotropic characteristics and develop transforms adapted to the local anisotropic characteristics of these residuals. The analysis indicates that many regions of motion compensated prediction residuals have 1-D anisotropic characteristics and we propose to use 1-D directional transforms for these regions. We present experimental results with one example set of such transforms within the H.264/AVC codec and the results indicate that the proposed transforms can improve the compression efficiency of motion compensated prediction residuals over conventional transforms. PMID:20923737

Kamisli, Fatih; Lim, Jae S

2011-04-01

138

Iron-based 1D nanostructures by electrospinning process  

Energy Technology Data Exchange (ETDEWEB)

Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe{sub 2}O{sub 3}) nanotubes and polycrystalline Fe{sub 3}C nanofibers were obtained by simple air or mixed gas (H{sub 2}, 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 (H{sub 2} and Ar) were used for the annealing treatments, for the first time polycrystalline Fe{sub 3}C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe{sub 3}C 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.

Eid, Cynthia; Asmar, Roy; Khoury, Antonio [Laboratoire de Physique Appliquee (LPA) associe a l' ecole doctorale des Sciences et Technologies, Departement de Physique, Universite Libanaise, Faculte des Sciences II, 90656 Jdeidet El Metn (Lebanon); Brioude, Arnaud; Salles, Vincent; Monteil, Yves; Miele, Philippe [Laboratoire des Multimateriaux et Interfaces (UMR CNRS 5615), Universite Lyon1, Universite de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne Cedex (France); Plenet, Jean-Claude [Laboratoire de Physique de la Matiere condensee et Nanostructures, CNRS UMR 5586, Universite Lyon1, Universite de Lyon, 43 Bd du 11 Novembre 1918, Villeurbanne Cedex (France); Khoury, Randa, E-mail: arnaud.brioude@univ-lyon1.fr [Laboratoire de Chimie, Faculte d' Agronomie, Universite Libanaise, Fanar, Faculte des Sciences II, 90656 Jdeidet El Metn (Lebanon)

2010-03-26

139

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.

140

Iron-based 1D nanostructures by electrospinning process  

Science.gov (United States)

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.

Eid, Cynthia; Brioude, Arnaud; Salles, Vincent; Plenet, Jean-Claude; Asmar, Roy; Monteil, Yves; Khoury, Randa; Khoury, Antonio; Miele, Philippe

2010-03-01

141

D1-D5-P microstates at the cap  

CERN Document Server

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

142

Image denoising by block-matching and 1D filtering  

Science.gov (United States)

In this paper, we develop a new image denoising method based on block-matching and transform-domain filtering. The developed method is derived from the current state-of-the-art denoising method (BM3D). We separate the 3D transform in the original method to two steps 1D transform, to further enhance the sparsity for signals whose elements are highly similar and to weaken the sparsity for those signals whose elements are dissimilar. Because the 1D filtering is on highly similar elements and the 2D filtering on image blocks are all removed, the image details can be better reserved and fewer artifacts are introduced than original method. Experimental results demonstrate that the developed method is competitive and better than some of the current state-of-the-art denoising methods in terms of peak signal-to-noise ratio, structural similarity, and subjective visual quality.

Hou, Yingkun; Chen, Tao; Yang, Deyun; Zhu, Lili; Yang, Hongxiang

2012-01-01

143

Simulation of sawtooth dynamics with a 1-D transport code  

International Nuclear Information System (INIS)

Simulation of sawtooth dynamics with a 1-D transport code is proposed as a useful tool for the study of sawtooth models. A sawtooth model, based on enhanced radial transport as a mechanism for the internal disruption, is discussed. This transport is triggered, when a resistively growing m=1 island exceeds its critical size, which depends on the local shear. Simulations of TFR and T-10 discharges show good agreement with experimentally observed sawteeth in Ohmically and electron cyclotron wave heated plasmas

144

Spectrum of 1D quasicrystals near the periodic chain  

OpenAIRE

A tight binding model on the general 1D quasiperiodic chain is studied in the framework of perturbation theory, near the corresponding periodic chain, using a new set of coordinates. The main gaps are well described, whereas the very small ones are correctly given, only for a very small perturbation. For a given irrational number, the energies where the gaps appear in the periodic chain spectrum, are exactly derived. Moreover, a labelling for these gaps which orders them according to their de...

Sire, Cle?ment; Mosseri, Re?my

1989-01-01

145

Blind Detection of Severely Blurred 1D Barcode  

OpenAIRE

In this paper, we present a joint blind channel estimation and symbol detection for decoding a blurred and noisy 1D barcode captured image. From an information transmission point of view, we show that the channel impulse response, the noise power and the symbols can be efficiently estimated by taking into account the signal structure such as the cyclostationary property of the hidden Markov process to estimate. Based on the Expectation-Maximisation method, we show that the new algorithm offer...

Dridi, Noura; Delignon, Yves; Sawaya, Wadih; Septier, Franc?ois

2010-01-01

146

Universal Luttinger Liquid Relations in the 1D Hubbard Model  

CERN Document Server

We study the 1D extended Hubbard model with a weak repulsive short-range interaction in the non-half-filled band case, using non-perturbative Renormalization Group methods and Ward Identities. At the critical temperature, T = 0, the response functions have anomalous power-law decay with multiplicative logarithmic corrections. The critical exponents, the susceptibility and the Drude weight verify the universal Luttinger liquid relations. Borel summability and (a weak form of) Spin-Charge separation is established.

Benfatto, Giuseppe; Mastropietro, Vieri

2011-01-01

147

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)

148

1D Cahn-Hilliard equation for modulated phase systems  

Energy Technology Data Exchange (ETDEWEB)

Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.

Villain-Guillot, Simon, E-mail: simon.villain-guillot@u-bordeaux1.f [Centre de Physique Moleculaire Optique et Hertzienne, Universite Bordeaux I, 351 cours de la Liberation 33405 Talence Cedex (France)

2010-05-21

149

Spatial stochastic resonance in 1D Ising systems  

CERN Document Server

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 the classical stochastic resonance phenomenon.

Neda, Z; Ravasz, E; Lakdawala, P; Gade, P M

1999-01-01

150

The Cosmological Mass Function with 1D Gravity  

OpenAIRE

The cosmological mass function problem is analyzed in full detail in the case of 1D gravity, with analytical, semi-analytical and numerical techniques. The extended Press & Schechter theory is improved by detailing the relation between smoothing radius and mass of the objects. This is done by introducing in the formalism the concept of a growth curve for the objects. The predictions of the extended Press & Schechter theory are compared to large N-body simulations of flat exp...

Monaco, Pierluigi; Murante, Giuseppe

1999-01-01

151

Chaotic Encryption Scheme Using 1-D Chaotic Map  

OpenAIRE

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...

Mina Mishra; Mankar, Vijay H.

2013-01-01

152

Symmetry distortion of extended 1-D ?-electron systems  

International Nuclear Information System (INIS)

It has been shown that a symmetry lowering from a state with higher symmetry to a state with lower symmetry (D(2m)d ? C(2m)) occurs in 1-D polymers with polymethine fragments as elementary units when electron-vibration interaction is taken into account. The investigations are carried out using an extended Su-Schrieffer-Heeger method, where the electron-electron interaction is taken into account

153

Two-Dimensional Digital Filters with Variable Magnitude Characteristics Obtained from a 1-D Monotonic Response  

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.

Venkat Ramachandran

2007-09-01

154

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

155

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)

156

Coupling of Nod1D and HOTCHANNEL: static case  

International Nuclear Information System (INIS)

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)

157

Generation of synthetic strong earthquake ground motions using a composite source model and synthetic green's functions  

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

158

Global Control Methods for GHZ State Generation on 1-D Ising Chain  

CERN Document Server

We discuss how to prepare an Ising chain in a GHZ state using a single global control field only. This model does not require the spins to be individually addressable and is applicable to quantum systems such as cold atoms in optical lattices, some liquid- or solid-state NMR experiments, and many nano-scale quantum structures. We show that GHZ states can always be reached asymptotically from certain easy-to-prepare initial states using adiabatic passage, and under certain conditions finite-time reachability can be ensured. To provide a reference useful for future experimental implementations three different control strategies to achieve the objective, adiabatic passage, Lyapunov control and optimal control are compared, and their advantages and disadvantages discussed, in particular in the presence of realistic imperfections such as imperfect initial state preparation, system inhomogeneity and dephasing.

Wang, Xiaoting; Bose, Sougato; Schirmer, Sophie

2010-01-01

159

Timescales, dynamical phase transitions and 3rd order phase transitions in the 1d anisotropic XY model  

OpenAIRE

Recent research into time-integrated observables has revealed a special class of states which cap- ture the singular features of the generating functions of those observables, as estimated by full counting statistics (FCS). In this work we extend the results of [Phys. Rev. B 87 184303 (2013)] to the 1d anisotropic XY -model and find a set of FCS critical points associated with the time-integrated transverse magnetization and anisotropy. We show dynamical phase transitions (D...

Hickey, James M.

2014-01-01

160

Extended-Range Ultrarefractive 1D Photonic Crystal Prisms  

Science.gov (United States)

A proposal has been made to exploit the special wavelength-dispersive characteristics of devices of the type described in One-Dimensional Photonic Crystal Superprisms (NPO-30232) NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 10a. A photonic crystal is an optical component that has a periodic structure comprising two dielectric materials with high dielectric contrast (e.g., a semiconductor and air), with geometrical feature sizes comparable to or smaller than light wavelengths of interest. Experimental superprisms have been realized as photonic crystals having three-dimensional (3D) structures comprising regions of amorphous Si alternating with regions of SiO2, fabricated in a complex process that included sputtering. A photonic crystal of the type to be exploited according to the present proposal is said to be one-dimensional (1D) because its contrasting dielectric materials would be stacked in parallel planar layers; in other words, there would be spatial periodicity in one dimension only. The processes of designing and fabricating 1D photonic crystal superprisms would be simpler and, hence, would cost less than do those for 3D photonic crystal superprisms. As in 3D structures, 1D photonic crystals may be used in applications such as wavelength-division multiplexing. In the extended-range configuration, it is also suitable for spectrometry applications. As an engineered structure or artificially engineered material, a photonic crystal can exhibit optical properties not commonly found in natural substances. Prior research had revealed several classes of photonic crystal structures for which the propagation of electromagnetic radiation is forbidden in certain frequency ranges, denoted photonic bandgaps. It had also been found that in narrow frequency bands just outside the photonic bandgaps, the angular wavelength dispersion of electromagnetic waves propagating in photonic crystal superprisms is much stronger than is the angular wavelength dispersion obtained by use of conventional prisms and diffraction gratings and is highly nonlinear.

Ting, David Z.

2007-01-01

161

Acute exercise and physiological insulin induce distinct phosphorylation signatures on TBC1D1 and TBC1D4 proteins in human skeletal muscle  

Science.gov (United States)

We investigated the phosphorylation signatures of two Rab-GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers exercised in the fasted or fed state and muscle biopsies were taken before and immediately after exercise. We identified TBC1D1/4 phospho-sites that (1) did not respond to exercise or postprandial increase in insulin (TBC1D4: S666), (2) responded to insulin only (TBC1D4: S318), (3) responded to exercise only (TBC1D1: S237, S660, S700; TBC1D4: S588, S751), and (4) responded to both insulin and exercise (TBC1D1: T596; TBC1D4: S341, T642, S704). In the insulin-stimulated leg, Akt phosphorylation of both T308 and S473 correlated significantly with multiple sites on both TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Interestingly, in the exercised leg in the fasted state TBC1D1 phosphorylation (S237, T596) correlated significantly with the activity of the ?2/?2/?3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) correlated with the activity of the ?2/?2/?1 AMPK trimer. Our data show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK regulated phosphorylation of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between species is problematic. Key points Phosphorylation signature patterns on TBC1D1 and TBC1D4 proteins in the insulin–glucose pathway were investigated in human skeletal muscle in response to physiological insulin and exercise. In response to postprandial increase in insulin, Akt phosphorylation of T308 and S473 correlated significantly with sites on TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Exercise induced phosphorylation of TBC1D1 (S237, T596) that correlated significantly with activity of the ?2/?2/?3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) with exercise correlated with activity of the ?2/?2/?1 AMPK trimer. TBC1D1 phosphorylation signatures with exercise/muscle contraction were comparable between human and mouse skeletal muscle, and AMPK regulated phosphorylation of these sites in mouse muscle, whereas contraction and exercise elicited different TBC1D4 phosphorylation patterns in mouse compared with human muscle. Our results show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and indicate that Akt and AMPK may be upstream kinases. PMID:24247980

Treebak, Jonas T; Pehmøller, Christian; Kristensen, Jonas M; Kjøbsted, Rasmus; Birk, Jesper B; Schjerling, Peter; Richter, Erik A; Goodyear, Laurie J; Wojtaszewski, Jørgen F P

2014-01-01

162

Quadratic Finite Element Method for 1D Deterministic Transport  

International Nuclear Information System (INIS)

In the discrete ordinates, or SN, numerical solution of the transport equation, both the spatial ((und r)) and angular ((und (Omega))) dependences on the angular flux ?(und r),(und (Omega))are modeled discretely. While significant effort has been devoted toward improving the spatial discretization of the angular flux, we focus on improving the angular discretization of ?(und r),(und (Omega)). Specifically, we employ a Petrov-Galerkin quadratic finite element approximation for the differencing of the angular variable (?) in developing the one-dimensional (1D) spherical geometry SN equations. We develop an algorithm that shows faster convergence with angular resolution than conventional SN algorithms

163

Particle transport in the 1-D diffusive atomic mix limit  

International Nuclear Information System (INIS)

A multiple length-scale asymptotic analysis shows that 1-D diffusive heterogeneous-media transport problems are accurately modeled by the atomic mix approximation when the optical widths of the 'chunks' of different materials are O(1). The atomic mix approximation is commonly known to be valid only when the chunks of different materials are optically thin. The analysis also shows that for the same class of problems, the Standard, or Levermore-Pomraning (LP) model does not have the correct asymptotic behavior. Numerical results are given that validate the theoretical predictions. (authors)

164

Feedback stabilization of a simplified 1d fluid- particle system  

OpenAIRE

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

165

Stabilization for 1D radiative and reactive viscous gas flows  

International Nuclear Information System (INIS)

We consider the compressible 1D-Navier-Stokes system for a viscous heat-conducting gas, with a pressure law p(?,?) = R?? + a/3?4 and a one-order kinetics to include radiative and reactive processes. The mass force and the ignition phenomenon are also taken into account. For large data and under general assumptions on the heat conductivity, we establish global in time bounds and exponential stabilization for solutions in Lq and H1-norms, by using new Lyapunov functionals. (authors)

166

Enhanced transmission of electromagnetic waves through 1D plasmonic crystals.  

Science.gov (United States)

Transmission of electromagnetic waves through thick perfect conducting slabs perforated by one-dimensional arrays of rectangular holes was studied experimentally in the microwave frequency range. The observed thickness-dependent transmission clearly exhibits the evanescent and propagating nature of the involved electromagnetic excitations on the considered structures, which are effective surface plasmons and localized waveguide resonances, respectively. The 1D crystals showing transmission based on localized resonances further manifests the frequency-dependent effective refractive index depending on the filling ratio of the holes and accompanies resonant guided wave propagation. PMID:20940913

So, Jin-Kyu; Jung, Hoe-Cheon; Min, Sun-Hong; Jang, Kyu-Ha; Bak, Seung-Ho; Park, Gun-Sik

2010-09-13

167

1D models for condensation induced water hammer in pipelines  

International Nuclear Information System (INIS)

Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)

168

1D models for condensation induced water hammer in pipelines  

Energy Technology Data Exchange (ETDEWEB)

Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)

Bloemeling, Frank; Neuhas, Thorsten; Schaffrath, Andreas [TUEV NORD SysTec GmbH und Co. KG, Hamburg (Germany)

2013-03-15

169

Coherent thermal conductance of 1-D photonic crystals  

International Nuclear Information System (INIS)

We present an exact calculation of coherent thermal conductance in 1-D multilayer photonic crystals using the S-matrix method. In particular, we study the thermal conductance in a bilayer structure of Si/vacuum or Al2O3/vacuum slabs by means of the exact radiative heat flux expression. Based on the results obtained for the Al2O3/vacuum structure we show by comparison with previous works that the material losses and (localized) surface modes supported by the inner layers play a fundamental role and cannot be omitted in the definition of thermal conductance. Our results could have significant implications in the conception of efficient thermal barriers.

170

A 1D analysis of two high order MOC methods  

International Nuclear Information System (INIS)

The work presented here provides two different methods for evaluating angular fluxes along long characteristics. One is based off a projection of the 1D transport equation onto a complete set of Legendre polynomials, while the other uses the 1D integral transport equation to evaluate the angular flux values at specific points along each track passing through a cell. The Moment Long Characteristic (M-LC) method is shown to provide 2(P+1) spatial convergence and significant gains in accuracy with the addition of only a few spatial degrees of freedom. The M-LC method, though, is shown to be ill-conditioned at very high order and for optically thin geometries. The Point Long Characteristic (P-LC) method, while less accurate, significantly improves stability to problems with optically thin cells. The P-LC method is also more flexible, allowing for extra angular flux evaluations along a given track to give a more accurate representation of the shape along each track. This is at the expense of increasing the degrees of freedom of the system, though, and requires an increase in memory storage. This work concludes that both may be used simultaneously within the same geometry to provide the best mix of accuracy and stability possible. (authors)

171

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

172

The ?1D-adrenergic receptor directly regulates arterial blood pressure via vasoconstriction  

OpenAIRE

To investigate the physiological role of the ?1D-adrenergic receptor (?1D-AR) subtype, we created mice lacking the ?1D-AR (?1D–/–) by gene targeting and characterized their cardiovascular function. In ?1D–/– mice, the RT-PCR did not detect any transcript of the ?1D-AR in any tissue examined, and there was no apparent upregulation of other ?1-AR subtypes. Radioligand binding studies showed that ?1-AR binding capacity in the aorta was lost, while that in the heart was unaltered ...

Tanoue, Akito; Nasa, Yoshihisa; Koshimizu, Takaaki; Shinoura, Hitomi; Oshikawa, Sayuri; Kawai, Takayuki; Sunada, Sachie; Takeo, Satoshi; Tsujimoto, Gozoh

2002-01-01

173

Acute exercise and physiological insulin induce distinct phosphorylation signatures on TBC1D1 and TBC1D4 in human skeletal muscle  

DEFF Research Database (Denmark)

We investigated the phosphorylation signatures of two Rab GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers exercised in the fasted or fed state and muscle biopsies were taken before and immediately after exercise. We identified TBC1D1/4 sites that did not respond to either exercise or insulin (TBC1D4: S666), that responded to insulin only (TBC1D4: S318), that responded to exercise only (TBC1D1: S237, S660, S700; TBC1D4: S588, S751), and that responded to both insulin and exercise (TBC1D1: T596; TBC1D4: S341, T642, S704). In the insulin stimulated leg, Akt phosphorylation on both T308 and S473 correlated significantly with multiple sites on both TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Interestingly, in the exercised leg in the fasted state TBC1D1 phosphorylation (S237, T596) correlated significantly with the activity ofthe ?2?2?3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) correlated with the activity of the ?2?2?1 AMPK trimer. Our data show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK was regulating phosphorylation of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between species are difficult.

Treebak, Jonas Thue; PehmØller, Christian

2014-01-01

174

Generation of Acoustic Signals from Buried Explosions  

Science.gov (United States)

Buried explosions generate both seismic and acoustic signals. The mechanism for the acoustic generation is generally assumed to be large ground motions above the source region that cause atmospheric pressure disturbances which can propagate locally or regionally depending on source size and weather conditions. In order to better understand the factors that control acoustic generation from buried explosions, we conducted a series of 200 lb explosions detonated in and above the dry alluvium and limestones of Kirtland AFB, New Mexico. In this experiment, nicknamed HUMBLE REDWOOD III, we detonated charges at heights of burst of 2 m (no crater) and depths of burst of 7 m (fully confined). The seismic and acoustic signals were recorded on a network of near-source (ballistic free fall of the near surface rock units, and ends with positive accelerations due to "slapdown" of the material. Spall seismograms were synthesized using emplacement media parameters and high-speed video observations of the surface movements. We present a comparison of the spall synthetics and acoustic waveforms for fully-confined explosions in both limestone and alluvium.

Bonner, J. L.; Reinke, R.; Waxler, R.; Lenox, E. A.

2012-12-01

175

Scandalously Parallelizable Mesh Generation  

OpenAIRE

We propose a novel approach which employs random sampling to generate an accurate non-uniform mesh for numerically solving Partial Differential Equation Boundary Value Problems (PDE-BVP's). From a uniform probability distribution U over a 1D domain, we sample M discretizations of size N where M>>N. The statistical moments of the solutions to a given BVP on each of the M ultra-sparse meshes provide insight into identifying highly accurate non-uniform meshes. Essentially, we u...

Bortz, David; Christlieb, Andrew

2011-01-01

176

PALLAS-1D(VII), Direct Integration of Transport Equation in 1-D Planar and Spherical Geometry  

International Nuclear Information System (INIS)

1 - Description of program or function: PALLAS-1D(VII) solves the steady state Boltzmann transport equation in one dimensional plan and spherical geometries for fixed source problems. It can also solve the transport of secondary gamma rays such as Bremsstrahlung and annihilation photons. 2 - Method of solution: The method of direct integration of the transport equation is used, in which the equation is integrated along the flight path of radiation in the direction of motion at each discrete ordinate direction. Anisotropic scattering is treated precisely using differential scattering cross sections for elastic scattering; however, isotropic scattering in the laboratory system is assumed in inelastic scattering of neutron. No iteration and convergence techniques are used for obtaining the flux. Energy dependence is treated by the multigroup approximation. 3 - Restrictions on the complexity of the problem: PALLAS-1D(VII) has been written in the fixed dimensioning, which restricts the numbers of energy meshes, material regions, nuclides, angular meshes, spatial meshes to be input

177

Three consistent approaches of the multiple cracking process in 1D composites  

Energy Technology Data Exchange (ETDEWEB)

Most modeling found in literature for the multiple cracking process of 1D composites can be categorised into three different approaches a Continuous Approach (CA) that assumes an infinitely long composite and two random approaches that consider composites of finite length. The Random Strength Approach (RSA) rests on a spatial discretization of the composite on which a strength distribution is applied whereas the Random Crack Approach (RCA) generates the location and the strength of each new crack without any discretization. The first part of the paper lays the model and its statistical foundations. They are used to demonstrate that the three approaches should provide consistent results. The three approaches are then introduced with special emphasis on the RCA as it is implemented for the first time without any approximation. Finally the results provided by the three approaches are compared confirming their full consistency. (authors)

Castelier, E. [CEA Cadarache, DEN SESC, F-13108 St Paul Les Durance (France); Gelebart, L. [CEA Saclay, DEN SRMA, F-91191 Gif Sur Yvette (France); Lacour, C.; Lantuejoul, C. [Mines ParisTech, F-77305 Fontainebleau (France)

2010-07-01

178

Evaluation of the 1D empirical mode decomposition method to smooth digital speckle pattern interferometry fringes  

Science.gov (United States)

The 1D empirical mode decomposition method is applied to reduce speckle noise in the correlation fringes produced in digital speckle pattern interferometry. This method is based on the decomposition of a signal in a sum of well-behaved fast and slow oscillation modes through a sifting process, which generates a fully data-driven technique. Consequently, this is an adaptive approach and the use of basis functions in the analysis process is not required. The denoised signal is given by the residue obtained after the fast oscillation modes are removed. The performance and limitations of the denoising technique are analyzed using computer simulated fringes and these results are compared with those obtained using a wavelet sub-band removal approach. An application of the EMD method to denoise experimental correlation fringes is also presented.

Bernini, María B.; Galizzi, Gustavo E.; Federico, Alejandro; Kaufmann, Guillermo H.

2007-06-01

179

Cardiolipin Binds to CD1d and Stimulates CD1d-Restricted ?? T cells in the Normal Murine Repertoire1,2  

OpenAIRE

Cardiolipin (CL), a major phospholipid in bacterial cell walls, is sequestered from the immune system in mammalian mitochondria and is, therefore, a potential “danger signal”. Based on growing evidence that phospholipids constitute natural ligands for CD1 and that CD1d-restricted T cells recognize phospholipids, we hypothesized that CD1d binds and presents CL, and that T cells in the normal immune repertoire respond to CL in a CD1d-restricted manner. We determined the murine CD1d-CL cryst...

Dieude?, Me?lanie; Striegl, Harald; Tyznik, Aaron J.; Wang, Jing; Behar, Samuel M.; Piccirillo, Ciriaco A.; Levine, Jerrold S.; Zajonc, Dirk M.; Rauch, Joyce

2011-01-01

180

Benchmarking of a 1D scrape-off layer code SOLF1D with SOLPS and its use in modelling long-legged divertors  

Science.gov (United States)

A 1D code modelling scrape-off layer (SOL) transport parallel to the magnetic field (SOLF1D) is benchmarked with 2D simulations of MAST-U SOL performed via the SOLPS code for two different collisionalities. Based on this comparison, SOLF1D is then used to model the effects of divertor leg stretching in 1D, in support of the planned Super-X divertor on MAST. The aim is to separate magnetic flux expansion from volumetric power losses due to recycling neutrals by stretching the divertor leg either vertically (?B? = 0 in the divertor) or radially (B ? 1/R).

Havlí?ková, E.; Fundamenski, W.; Subba, F.; Coster, D.; Wischmeier, M.; Fishpool, G.

2013-06-01

181

Benchmarking of a 1D scrape-off layer code SOLF1D with SOLPS and its use in modelling long-legged divertors  

International Nuclear Information System (INIS)

A 1D code modelling scrape-off layer (SOL) transport parallel to the magnetic field (SOLF1D) is benchmarked with 2D simulations of MAST-U SOL performed via the SOLPS code for two different collisionalities. Based on this comparison, SOLF1D is then used to model the effects of divertor leg stretching in 1D, in support of the planned Super-X divertor on MAST. The aim is to separate magnetic flux expansion from volumetric power losses due to recycling neutrals by stretching the divertor leg either vertically (?B? = 0 in the divertor) or radially (B ? 1/R). (paper)

182

Slug modeling with 1D two-fluid model  

International Nuclear Information System (INIS)

Simulations of condensation-induced water hammer with one-dimensional two-fluid model requires explicit modeling of slug formation, slug propagation, and in some cases slug decay. Stratified flow correlations that are more or less well known in 1D two-fluid models, are crucial for accurate description of the initial phase of the slug formation and slug propagation. Slug formation means transition to other flow regime that requires different set of correlations. To use such two-fluid model for condensation induced water hammer simulations, a single slug must be explicitly recognized and captured. In the present work two cases of condensation-induced water hammer simulations performed with WAHA code, are described and discussed: injection of cold liquid into horizontal pipe filled with steam and injection of hot steam into horizontal pipe partially filled with cold liquid. (orig.)

183

Neutral excitations in quasi-1D strongly correlated electron systems  

International Nuclear Information System (INIS)

Novel neutral spin-0 excitation for quasi-1D systems with one electron per site are obtained within a localized scheme. Our ground state wave-function is defined by a variational localized - site cluster - expanded ansatz and these excitations are naturally built upon it. All computations are easily carried out by a transfer matrix technique that enables explicit inclusion of electron - correlation effects and, at the same time, provides a quasi - particle band - theoretic picture of these excitations. This treatment is applied, in particular, to a polyphene strip. At k=0 the energy gap corresponds to a dipole-allowed transition in the visible region, our result compares fairly well with observed decreasing transitions for finite polyphene strips. (author). 14 refs, 1 fig

184

Slug modeling with 1D two-fluid model  

Energy Technology Data Exchange (ETDEWEB)

Simulations of condensation-induced water hammer with one-dimensional two-fluid model requires explicit modeling of slug formation, slug propagation, and in some cases slug decay. Stratified flow correlations that are more or less well known in 1D two-fluid models, are crucial for accurate description of the initial phase of the slug formation and slug propagation. Slug formation means transition to other flow regime that requires different set of correlations. To use such two-fluid model for condensation induced water hammer simulations, a single slug must be explicitly recognized and captured. In the present work two cases of condensation-induced water hammer simulations performed with WAHA code, are described and discussed: injection of cold liquid into horizontal pipe filled with steam and injection of hot steam into horizontal pipe partially filled with cold liquid. (orig.)

Tiselj, Iztok [Jozef Stefan Institute, Ljubljana (Slovenia). Reactor Engineering Div.; Martin, C. Samuel [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering

2012-05-15

185

Effective slip boundary conditions for 1D periodic surfaces  

CERN Document Server

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

186

1D-transport properties of single superconducting lead nanowires  

DEFF Research Database (Denmark)

We report on the transport properties of single superconducting lead nanowires grown by an electrodeposition technique, embedded in a nanoporous track-etched polymer membrane. The nanowires are granular, have uniform diameter of ?40 nm and a very large aspect ratio (?500). The diameter of the nanowire is small enough to ensure a 1D superconducting regime in a wide temperature range below T. The non-zero resistance in the superconducting state and its variation caused by fluctuations of the superconducting order parameter were measured versus temperature, magnetic field, and applied DC current (or voltage). The current induced breakdowns in the V-I characteristics may be explained by the formation of phase slip centers. Moreover, DC voltage driven measurements reveal the existence of a new S-shape behavior near the formation of these phase slip centers. © 2003 Elsevier B.V. All rights reserved.

Michotte, S.; Mátéfi-Tempfli, Stefan

2003-01-01

187

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.

188

MX chains: 1-D analog of CuO planes?  

International Nuclear Information System (INIS)

We study a two-band Peierls-Hubbard model for halogen-bridged mixed-valence transition metal linear chain complexes (MX chains). We include electron-electron correlations (both Hubbard and PPP-like expressions) using several techniques including calculations in the zero-hopping limit, exact diagonalization of small systems, mean field approximation, and a Gutzwiller-like Ansatz for quantum phonons. The adiabatic optical absorption and phonon spectra for both photo-excited and doping induced defects (kinks, polarons, bipolarons, and excitons) are discussed. A long period phase which occurs even at commensurate filling for certain parameter values may be related to twinning. The effect of including the electron-phonon in addition to the electron-electron interaction on the polaron/bipolaron (pairing) competition is especially interesting when this class of compounds is viewed as a 1-D analog of high-temperature superconductors. 6 refs., 4 figs

189

Microlens Masses from 1-D Parallaxes and Heliocentric Proper Motions  

CERN Document Server

One-dimensional (1-D) microlens parallaxes can be combined with heliocentric lens-source relative proper motion measurements to derive the lens mass and distance, as suggested by Ghosh et al. (2004). Here I present the first mathematical anlysis of this procedure, which I show can be represented as a quadratic equation. Hence, it is formally subject to a two-fold degeneracy. I show that this degeneracy can be broken in many cases using the relatively crude 2-D parallax information that is often available for microlensing events. I also develop an explicit formula for the region of parameter space where it is more difficult to break this degeneracy. Although no mass/distance measurements have yet been made using this technique, it is likely to become quite common over the next decade.

Gould, Andrew

2014-01-01

190

Magnetic exchange interactions in 1D and 2D cuprates  

International Nuclear Information System (INIS)

In many copper oxygen networks, especially for Cu-O bond angles close to 90 , ferromagnetic (FM) interactions play an important role in addition to the well known superexchange J ? t2/U. We present a systematic study of the electronic structure and the exchange integrals J for different types of 1D and 2D spin 1/2 cuprates: edge shared (Li2CuO2) and corner shared (A2CuO3 [A=Sr,Ca]) single-chains, double-chains (SrCuO2), and planar (CaCuO2, Sr2CuO2Cl2, R2CuO4 [R=La,Nd,Sm]) arrangements. Based on full potential LDA and LDA+U band structure calculations and subsequent tight-binding (TB) models we estimate sign and magnitude of the most relevant J's. We compare the results of total energy calculations with those of TB models from one-band and multi-band approaches. The FM contributions can be estimated from the difference between the TB and the total energy results. We investigate the effect of the inter-plaquette geometry (edge shared vs. corner shared CuO2 plaquettes) and the intra-plaquette geometry under pressure on the coupling strength. In excellent agreement with various experiments, our calculations result in; (i) dominant FM nearest neighbor (NN) coupling J1?-17 meV in Li2CuO2, (ii) strongly enhanced AFM NN J1?180 meV for the 1D corner shared chains compared to (iii) Jared chains compared to (iii) J1?110..150 meV for the 2D compounds where we observe a sequence of J's (with respect to the cations) in agreement with the experimental data. (orig.)

191

Optical reflectance and omnidirectional bandgaps in Fibonacci quasicrystals type 1-D multilayer structures containing exponentially graded material  

Science.gov (United States)

A theoretical study of optical reflectance and reflection bands of 1-D photonic quasi-crystals (Fibonacci type arrangement) composed of exponentially graded material is presented. The proposed structures consist of two different layers, one of them is of constant refractive index (L) and the other one is of exponentially graded refractive index (S) dielectric materials. Four different generations (2nd, 3rd, 4th and 5th) of the Fibonacci sequence for 10 periods in one dimension (1-D) are considered and compared in view of their optical reflectance and bandgaps for both TE and TM polarisations. Also, we proposed some heterostructures made by the combination of different Fibonacci generations and their periods to obtain suitable omnidirectional reflection band. We used the transfer matrix method (TMM) to obtain the reflectance, bandgaps and omnidirectional reflectional bandgaps (ODR) of such structures in near infrared spectrum (800-2200 nm) at different angles of incidence. We show that ODR exists in these types of structures. The number of ODRs and total bandgap depend on the Fibonacci generations. Extraordinary ODR bandgaps are obtained in the case of heterostructures formed by the combination of different generations of the Fibonacci sequence. The ODR for these structures is similar to the ODR of photonic crystals containing left-handed materials. This work would be useful to study the Fibonacci type photonic crystals having graded index materials and also it will open new window to design several photonic crystal devices like sensors, reflectors, etc. in the infrared region.

Singh, Bipin K.; Thapa, Khem B.; Pandey, Praveen C.

2013-06-01

192

SPATIOTEMPORAL INHIBITION OF INNATE IMMUNITY SIGNALING BY THE TBC1D23 RAB-GAP1  

OpenAIRE

We previously identified Tbc1d23 as a candidate novel regulator of innate immunity using comparative genomics RNAi screens in C. elegans and mouse macrophages. Using Tbc1d23 knockout mice and macrophages engineered to overexpress Tbc1d23, we now show that Tbc1d23 is a general inhibitor of innate immunity signaling, strongly inhibiting multiple Toll-like receptor (TLR) and Dectin signaling pathways. Tbc1d23 likely acts downstream of the TLR signaling adaptors MyD88 and Trif and upstream of the...

Arras, Lesly; Yang, Ivana V.; Lackford, Brad; Riches, David W. H.; Prekeris, Rytis; Freedman, Jonathan H.; Schwartz, David A.; Alper, Scott

2012-01-01

193

TBC1D1 Regulates Insulin- and Contraction-Induced Glucose Transport in Mouse Skeletal Muscle  

OpenAIRE

OBJECTIVE: TBC1D1 is a member of the TBC1 Rab-GTPase family of proteins and is highly expressed in skeletal muscle. Insulin and contraction increase TBC1D1 phosphorylation on phospho-Akt substrate motifs (PASs), but the function of TBC1D1 in muscle is not known. Genetic linkage analyses show a TBC1D1 R125W missense variant confers risk for severe obesity in humans. The objective of this study was to determine whether TBC1D1 regulates glucose transport in skeletal muscle. RESEARCH DESIGN AND M...

Toyoda, Taro; Yu, Haiyan; Fujii, Nobuharu; Hirshman, Michael F.; An, Ding Jeff; Goodyear, Laurie Joy; Taylor, Eric B.

2010-01-01

194

The ?1D-adrenergic receptor directly regulates arterial blood pressure via vasoconstriction  

Science.gov (United States)

To investigate the physiological role of the ?1D-adrenergic receptor (?1D-AR) subtype, we created mice lacking the ?1D-AR (?1D–/–) by gene targeting and characterized their cardiovascular function. In ?1D–/– mice, the RT-PCR did not detect any transcript of the ?1D-AR in any tissue examined, and there was no apparent upregulation of other ?1-AR subtypes. Radioligand binding studies showed that ?1-AR binding capacity in the aorta was lost, while that in the heart was unaltered in ?1D–/– mice. Non-anesthetized ?1D–/– mice maintained significantly lower basal systolic and mean arterial blood pressure conditions, relative to wild-type mice, and they showed no significant change in heart rate or in cardiac function, as assessed by echocardiogram. Besides hypotension, the pressor responses to phenylephrine and norepinephrine were decreased by 30–40% in ?1D–/– mice. Furthermore, the contractile response of the aorta and the pressor response of isolated perfused mesenteric arterial beds to ?1-AR stimulation were markedly reduced in ?1D–/– mice. We conclude that the ?1D-AR participates directly in sympathetic regulation of systemic blood pressure by vasoconstriction. PMID:11901185

Tanoue, Akito; Nasa, Yoshihisa; Koshimizu, Takaaki; Shinoura, Hitomi; Oshikawa, Sayuri; Kawai, Takayuki; Sunada, Sachie; Takeo, Satoshi; Tsujimoto, Gozoh

2002-01-01

195

1D Optimization of Uniformly Cu Doped Beryllium Ignition Capsules  

Science.gov (United States)

An ignition capsule can be tuned by iteratively adjusting the laser pulses in 2D radiation hydrodynamic simulations of a capsule and hohlraum. However, a multitude of optimally tuned designs may be necessary to choose among design options, such as peak laser power and energy, dopant concentration, ablator thickness, DT ice thickness, and other parameters. We use a frequency dependent radiation source derived from 2D integrated calculations to explore the levels and timings of the radiation pulses created by four laser pulses across many 1D calculations. The first pulse is fixed at a level sufficient to melt the beryllium. The fourth pulse duration and length are determined by the laser energy and peak power. Pulse levels and timings are adjusted so that all shocks coalesce just inside the DT ice/gas interface (Munro et al., 2001). In addition to varying ablator and ice thickness (e.g. Haan et al., 2005) we have varied the laser energy, peak laser power, and dopant level, seeking designs optimizing several parameters, including yield (with and without alpha deposition), peak no-burn temperature, rho-r, and velocity. This optimization leads us to low dopant concentrations (0.1 to 0.3%) with thick ablators (˜160-190 microns) for further 2D analysis.

Yirak, Kristopher; Wilson, Douglas; Simakov, Andrei; Kline, John; Salmonson, Jay; Milovich, Jose; Clark, Daniel; Callahan, Debbie; Sepke, Scott

2012-10-01

196

Three-field modeling for MARS 1-D code  

International Nuclear Information System (INIS)

In this study, the three-field modeling of the two-phase mixture is developed. The finite difference equations for the three-field equations thereafter are devised. The solution scheme has been implemented into the MARS 1-D code. The three-field formulations adopted are similar to those for MARS 3-D module, in a sense that the mass and momentum are treated separately for the entrained liquid and continuous liquid. As in the MARS-3D module, the entrained liquid and continuous liquid are combined into one for the energy equation, assuming thermal equilibrium between the two. All the non-linear terms are linearized to arrange the finite difference equation set into a linear matrix form with respect to the unknown arguments. The problems chosen for the assessment of the newly added entrained field consist of basic conceptual tests. Among the tests are gas-only test, liquid-only test, gas-only with supplied entrained liquid test, Edwards pipe problem, and GE level swell problem. The conceptual tests performed confirm the sound integrity of the three-field solver

197

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

198

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 dld 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) th

199

1D modeling of snow photochemistry at Summit Greenland  

Science.gov (United States)

Reactive halogens in Arctic regions and their impact on ozone levels have been a subject of intensive research since the mid 1980s, in particular in regions close to first-year sea ice. Motivated by indirect evidence that reactive halogens are also present on the Greenland ice shield, two field campaigns have been conducted at Summit, Greenland in 2007 and 2008. The purpose of these studies was to measure air and snow properties with a particular focus on halogen and HOx chemistry in snow covered remote regions. Initial results show evidence for halogen chemistry with BrO concentrations measured up to 3 ppt with the UCLA long path DOAS instrument. In order to understand the chemical and physical processes occurring during these field experiments we have developed a new 1D model for snow physics and chemistry. This model has been coupled to the boundary layer model MISTRA, which includes detailed multiphase chemistry in the atmosphere, with the goal of understanding how chemical species evolve with time in the interstitial air and to study the interplay between the chemistry in and above the snow. The importance of gas exchange will be highlighted as well at the necessity for studies to quantify the ion content of the liquid layer on snow grains. The methodology for modeling the multiphase in-snow chemistry will be presented along with results from this new model, including vertical profiles of halogens in the snow pack and in the atmosphere along with their evolution in time.

Thomas, J. L.; Stutz, J.; von Glasow, R.

2009-04-01

200

1D Multiphase Modeling of Chemistry Over Remote Ice Sheets  

Science.gov (United States)

Motivated by observations of reactive nitrogen and halogen chemistry over the Greenland ice sheet we have developed a 1D model for snow physics and chemistry. This model has been coupled to the boundary layer model MISTRA, which includes detailed multiphase chemistry in the atmosphere. The goal of our project was to provide a framework to quantify the chemistry in the interstitial air and to study the interplay between the chemistry in and above the snow. The methodology for modeling the multiphase in-snow chemistry will be presented along with results from the model, including vertical profiles of ozone, NOx, and halogens in the snow pack and in the atmosphere. Gas-phase and aqueous phase chemical processes controlling these species in snow covered regions are analyzed and the implications for modeling NOx and ozone fluxes over remote ice sheets will be discussed. Model data will be presented in the context of past and ongoing field campaigns at Summit Research Station. The needs for future research on interstitial air gas transport and ice chemistry will be highlighted.

Thomas, J. L.; Stutz, J.; von Glasow, R.

2009-12-01

201

Control and imaging of O(1D2) precession  

Science.gov (United States)

Larmor precession of a quantum mechanical angular momentum vector about an applied magnetic field forms the basis for a range of magnetic resonance techniques, including nuclear magnetic resonance spectroscopy and magnetic resonance imaging. We have used a polarized laser pump-probe scheme with velocity-map imaging detection to visualize, for the first time, the precessional motion of a quantum mechanical angular momentum vector. Photodissociation of O2 at 157 nm provides a clean source of fast-moving O(1D2) atoms, with their electronic angular momentum vector strongly aligned perpendicular to the recoil direction. In the presence of an external magnetic field, the distribution of atomic angular momenta precesses about the field direction, and polarization-sensitive images of the atomic scattering distribution recorded as a function of field strength yield ‘time-lapse-photography’ style movies of the precessional motion. We present movies recorded in various experimental geometries, and discuss potential consequences and applications in atmospheric chemistry and reaction dynamics.

Wu, Shiou-Min; Radenovic, Dragana ?.; van der Zande, Wim J.; Groenenboom, Gerrit C.; Parker, David H.; Vallance, Claire; Zare, Richard N.

2011-01-01

202

1D and 3D resistivity inversions for geotechnical investigation  

International Nuclear Information System (INIS)

The resistivity method is frequently used in the investigation of the shallow parts of the earth. Interpretation of such data is usually done assuming a layered earth. However, a more complete imaging can be obtained if 3D models are used. Thirty-five vertical electrical soundings (VES) were carried out in a regular mesh at the northwestern part of Greater Cairo in order to characterize different geological units and to study their quality for building foundations. Models obtained from 1D inversion of each VES, together with borehole information, were used for construction of eight geoelectrical sections which exhibit the main geoelectrical characteristics of the geological units present in the area. The 3D inversion of the data indicated a complex subsurface electrical resistivity distribution conditioned by lithology, water content and tectonic structures. The results indicate that the subsurface consists of different geologic units such as gravel and sand, sand, clay and limestone. The main results are related to the characterization of the clay formations in the north of the survey area, which is revealed by low-resistivity values (600 ? m) depicted in the central part of the study zone

203

Modeling ECRIS using 1D multi-fluid  

International Nuclear Information System (INIS)

The Department of Experimental and Applied Physics (IEAP) at the University of Kiel (CAU Kiel) is establishing a solar wind laboratory for the calibration of space instrumentation. The main item of this facility is a 11 GHz (Plateau) ECR ion source. It can be operated at two different radial magnetic confinements, using a set of permanent magnets in either hexapole or dodeca-pole arrangement. While beam focussing by moving the extraction along the beam line to match the ion beam into the analysing magnet is well known, little is known about beam steering by moving the extraction in the plane perpendicular to the beam line. The 1D-multi-fluid model allows a simple coupling between measured charge-state distribution and plasma parameters. We can draw 5 conclusions from the study: 1) the simulations reproduce the expected characteristic charge state distributions; 2) the influence of individual fluid velocities is small but can be relevant for the higher charge states; 3) singly charged ions are not well modeled as a fluid; 4) for medium electron densities, ion drifts make about half of the influence of the ion temperature to the extracted currents of highly charged ions; and 5) very low neutral gas pressure could allow the production of highly charged ions. This document is composed of an abstract followed by the slides of the presentation. (author)

204

Electrodeposition of photoactive 1D gallium selenide quantum dots  

Energy Technology Data Exchange (ETDEWEB)

One-dimensional (1D) quantum dots of gallium selenide have been obtained by cathodic electrodeposition onto the tin doped indium oxide (ITO) glass substrates from aqueous acidic solutions at room temperature. Characterizations of the as-deposited films by energy dispersive X-ray (EDX) spectroscopy confirm a selenium rich chemistry, X-ray diffraction (XRD) shows that mixture of phases like GaSe/Ga{sub 2}Se{sub 3}, and optical spectroscopy shows a direct optical band gap of 2.85 eV with intermediate transition energy at 1.9 eV. From transmission electron microscopy (TEM), the films show the one-dimensional quantum dots chains in grains. Scanning electron microscopy (SEM) images indicate dimorphous placement of nanoparticles. The elementals surface analysis of the core-shell nanoparticles determined by X-ray photoelectron spectroscopy (XPS) supported the EDX results and confirmed the chemical nature of the material. The photoelectrochemical (PEC) studies of gallium selenide films were carried out and the nanocrystalline gallium selenide films were found to be photoactive in aqueous sodium thiosulphate solution.

Gujar, T.P. [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of)], E-mail: gujar_tp@yahoo.com; Shinde, V.R. [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); Park, Jong-Won [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); The Industrial Chemistry, University of Sang-Myung, Seoul 130-650 (Korea, Republic of); Lee, Hyun Kyung [Industrial Chemistry, University of Sang-Myung, Seoul 130-650 (Korea, Republic of); Jung, Kwang-Deog [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of); Joo, Oh-Shim [Clean Energy Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650 (Korea, Republic of)], E-mail: joocat@kist.re.kr

2008-12-30

205

Electrodeposition of photoactive 1D gallium selenide quantum dots  

International Nuclear Information System (INIS)

One-dimensional (1D) quantum dots of gallium selenide have been obtained by cathodic electrodeposition onto the tin doped indium oxide (ITO) glass substrates from aqueous acidic solutions at room temperature. Characterizations of the as-deposited films by energy dispersive X-ray (EDX) spectroscopy confirm a selenium rich chemistry, X-ray diffraction (XRD) shows that mixture of phases like GaSe/Ga2Se3, and optical spectroscopy shows a direct optical band gap of 2.85 eV with intermediate transition energy at 1.9 eV. From transmission electron microscopy (TEM), the films show the one-dimensional quantum dots chains in grains. Scanning electron microscopy (SEM) images indicate dimorphous placement of nanoparticles. The elementals surface analysis of the core-shell nanoparticles determined by X-ray photoelectron spectroscopy (XPS) supported the EDX results and confirmed the chemical nature of the material. The photoelectrochemical (PEC) studies of gallium selenide films were carried out and the nanocrystalline gallium selenide films were found to be photoactive in aqueous sodium thiosulphate solution

206

Nonlinear electrical conductivity in a 1D granular medium  

CERN Document Server

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

207

Transport properties of 1D disordered models a novel approach  

CERN Document Server

A new method is developed for the study of transport properties of 1D models with random potentials. It is based on an exact transformation that reduces discrete Schr\\"odinger equation in the tight-binding model to a two-dimensional Hamiltonian map. This map describes the behavior of a classical linear oscillator under random parametric delta-kicks. We are interested in the statistical properties of the transmission coefficient $T_L$ of a disordered sample of length $L$. In the ballistic regime we derive expressions for the mean value of the transmission coefficient $T_L$, its second moment and variance, that are more accurate than the existing ones. In the localized regime we analyze the global characteristics of $\\ln T_L$, and demonstrate that its distribution function approaches the Gaussian form if $L\\to \\infty$. For any finite $L$ there are deviations from the Gaussian law that originate from the subtle correlation effects between different trajectories of the Hamiltonian map.

Dossetti-Romero, V; Krokhin, A A

2002-01-01

208

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.

209

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

210

An Efficient Algorithm for approximating 1D Ground States  

CERN Document Server

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

211

Phage display-derived recombinant antibodies with TCR-like specificity against alpha-galactosylceramide and its analogues in complex with human CD1d molecules.  

OpenAIRE

The glycolipid alpha-galactosylceramide (alpha-GalCer) is a potent activator of invariant natural killer T (iNKT) cells and has been shown to be an effective agent against cancer, infections and autoimmune diseases. The effectiveness of alpha-GalCer and its alkyl chain analogues depends on efficient loading and presentation by the antigen-presenting molecule CD1d. To monitor the ability of CD1d to present the glycolipids, we have used a phage display strategy to generate recombinant antibodie...

Denkberg, G.; Stronge, Vs; Zahavi, E.; Pittoni, P.; Oren, R.; Shepherd, D; Salio, M.; Mccarthy, C.; Illarionov, Pa; Merwe, A.; Besra, GS; Dellabona, P.; Casorati, G.; Cerundolo, V.; Reiter, Y.

2008-01-01

212

Multiplet structure of the defect modes in 1D helical photonic crystals with twist defects  

International Nuclear Information System (INIS)

We theoretically analyse the defect modes generated by equispaced twist defects in 1D helical (cholesteric-like) structures within their frequency gap which is such that only the first two of the four eigenwaves 1±, 2± are exponentially attenuated. n0 identical defects generate n0 different defect modes, each one represented by a linear combination of the four eigenwaves. The components 1+ and 1- are by far the dominant ones and they are localized near the defect planes. We give exact analytic expressions for the elements of the transfer and scattering matrices of the defect planes, for the functions defining the defect mode when n0 = 1, and for the defect frequencies when n0 = 1, 2, 3. In the particular case n0 = 2 and twist angle ? = ?/2, the difference between the two defect wavelengths ?d2, ?d1 depends exponentially on the distance z1 between the defect planes, going to zero for z1 ? ? and becoming as large as the entire frequency gap for z1 ? 0

213

Spatio-temporal stability of 1D Kerr cavity solitons  

Science.gov (United States)

The Lugiato-Lefever equation (LLE) has been extensively studied since its derivation in 1987, when this meanfield model was introduced to describe nonlinear optical cavities. The LLE was originally derived to describe a ring cavity or a Fabry-Perot resonator with a transverse spatial extension and partially filled with a nonlinear medium but it has also been shown to be applicable to other types of cavities, such as fiber resonators and microresonators. Depending on the parameters used, the LLE can present a monostable or bistable input-output response curve. A large number of theoretical studies have been done in the monostable regime, but the bistable regime has remained widely unexplored. One of the reasons for this was that previous experimental setups were not able to works in such regimes of the parameter space. Nowadays the possibility of reaching such parameter regimes experimentally has renewed the interest in the LLE. In this contribution, we present an in-depth theoretical study of the different dynamical regimes that can appear in parameter space, focusing on the dynamics of localized solutions, also known as cavity solitons (CSs). We show that time-periodic oscillations of a 1D CS appear naturally in a broad region of parameter space. More than this oscillatory regime, which has been recently demonstrated experimentally,1 we theoretically report on several kinds of chaotic dynamics. We show that the existence of CSs and their dynamics is related with the spatial dynamics of the system and with the presence of a codimension-2 point known as a Fold-Hopf bifurcation point. These dynamical regimes can become accessible by using devices such as microresonators, for instance widely used for creating optical frequency combs.

Gelens, L.; Parra-Rivas, P.; Leo, F.; Gomila, D.; Matias, Manuel A.; Coen, S.

2014-05-01

214

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

Science.gov (United States)

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 cell-defects 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. PMID:24755556

Shin, Jung Hoon; Park, Se-Ho

2014-05-01

215

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

CERN Document Server

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

216

Identification of T1D susceptibility genes within the MHC region by combining protein interaction networks and SNP genotyping data  

DEFF Research Database (Denmark)

To develop novel methods for identifying new genes that contribute to the risk of developing type 1 diabetes within the Major Histocompatibility Complex (MHC) region on chromosome 6, independently of the known linkage disequilibrium (LD) between human leucocyte antigen (HLA)-DRB1, -DQA1, -DQB1 genes. We have developed a novel method that combines single nucleotide polymorphism (SNP) genotyping data with protein-protein interaction (ppi) networks to identify disease-associated network modules enriched for proteins encoded from the MHC region. Approximately 2500 SNPs located in the 4 Mb MHC region were analysed in 1000 affected offspring trios generated by the Type 1 Diabetes Genetics Consortium (T1DGC). The most associated SNP in each gene was chosen and genes were mapped to ppi networks for identification of interaction partners. The association testing and resulting interacting protein modules were statistically evaluated using permutation. A total of 151 genes could be mapped to nodes within the protein interaction network and their interaction partners were identified. Five protein interaction modules reached statistical significance using this approach. The identified proteins are well known in the pathogenesis of T1D, but the modules also contain additional candidates that have been implicated in beta-cell development and diabetic complications. The extensive LD within the MHC region makes it important to develop new methods for analysing genotyping data for identification of additional risk genes for T1D. Combining genetic data with knowledge about functional pathways provides new insight into mechanisms underlying T1D.

Brorsson, C.; Hansen, Niclas Tue

2009-01-01

217

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

OpenAIRE

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

218

A peptide targeting an interaction interface disrupts the dopamine D1-D2 receptor heteromer to block signaling and function in vitro and in vivo: effective selective antagonism.  

Science.gov (United States)

Although the dopamine D1-D2 receptor heteromer has emerging physiological relevance and a postulated role in different neuropsychiatric disorders, such as drug addiction, depression, and schizophrenia, there is a need for pharmacological tools that selectively target such receptor complexes in order to analyze their biological and pathophysiological functions. Since no selective antagonists for the D1-D2 heteromer are available, serial deletions and point mutations were used to precisely identify the amino acids involved in an interaction interface between the receptors, residing within the carboxyl tail of the D1 receptor that interacted with the D2 receptor to form the D1-D2 receptor heteromer. It was determined that D1 receptor carboxyl tail residues (404)Glu and (405)Glu were critical in mediating the interaction with the D2 receptor. Isolated mutation of these residues in the D1 receptor resulted in the loss of agonist activation of the calcium signaling pathway mediated through the D1-D2 receptor heteromer. The physical interaction between the D1 and D2 receptor could be disrupted, as shown by coimmunoprecipitation and BRET analysis, by a small peptide generated from the D1 receptor sequence that contained these amino acids, leading to a switch in G-protein affinities and loss of calcium signaling, resulting in the inhibition of D1-D2 heteromer function. The use of the D1-D2 heteromer-disrupting peptide in vivo revealed a pathophysiological role for the D1-D2 heteromer in the modulation of behavioral despair. This peptide may represent a novel pharmacological tool with potential therapeutic benefits in depression treatment. PMID:25063849

Hasbi, Ahmed; Perreault, Melissa L; Shen, Maurice Y F; Zhang, Lucia; To, Ryan; Fan, Theresa; Nguyen, Tuan; Ji, Xiaodong; O'Dowd, Brian F; George, Susan R

2014-11-01

219

1-D Experimental Study on the Two-Phase Natural Circulation Flow under ERVC  

International Nuclear Information System (INIS)

To observe and evaluate the two-phase natural circulation phenomena through the gap between the reactor vessel and the insulation in the APR1400 under an external vessel cooling, the T-HERMES (Thermo- Hydraulic Evaluations of Reactor vessel cooling Mechanisms by External Self-induced flow) program has been performed at KAERI. The HERMES-HALF study, which is one of the THERMES programs, has been performed to observe and evaluate the two-phase natural circulation phenomena through the gap between the reactor vessel and the insulation in the APR1400. The HERMES-HALF is a non-heating and a half-scaled three-dimensional experimental study on the two-phase natural circulation through the annular gap between the reactor vessel and the insulation. The behaviors of the two-phase natural circulation flow in the insulation gap are observed, and the liquid mass flow rates driven by the natural circulation loop are measured. From the HERMES-HALF experimental results, the natural circulation flow rate can be generated up to 200kg/s by adjusting the inlet and outlet area of the insulation. This flow rate value is the same as the 323kg/m2s mass flux value normalized with the annular section area. Compared to the KAIST and SULTAN experimental results, the CHF values reach about 1.3 . 1.5MW/m2 at the top of the lower head vessel (90 degrees) based on the 323kg/m2s mass flux which is measured from the HERMES-HALF experiments. Though the scaling law is ad experiments. Though the scaling law is adapted to the HERMES-HALF experimental facility, the similarity of the non-heating experiment to the heating experiment should be certified. This property scaling and geometry scaling should be studied to apply the experimental data to a real APR1400. A T-HERMES-1D study has been launched to evaluate the property and geometry scaling of the HERMES-HALF experimental results. The T-HERMES-1D is a one dimensional non-heating / heating experimental study on a two-phase natural circulation through the annular gap between the reactor vessel and the insulation. For the property scaling, the non-heating results should be compared with heating experimental ones. That is, a coolant sub-cooling effect, such as a steam bubble behavior and a flashing effect, and a natural circulation flow instability should be evaluated. For the geometry scaling, the 1-D phenomena should be compared with the 3-D ones of HERMES-HALF. In this paper, the T-HERMES-1D experimental facility and preliminary loop analytical results were presented

220

Statistical Properties of Ideal Ensemble of Disordered 1D Steric Spin-Chains  

OpenAIRE

The statistical properties of ensemble of disordered 1D steric spin-chains (SSC) of various length are investigated. Using 1D spin-glass type classical Hamiltonian, the recurrent trigonometrical equations for stationary points and corresponding conditions for the construction of stable 1D SSCs are found. The ideal ensemble of spin-chains is analyzed and the latent interconnections between random angles and interaction constants for each set of three nearest-neighboring spins...

Gevorkyan, Ashot; Abajyan, Hakob; Sukiasyan, Haik

2010-01-01

221

Exercise increases TBC1D1 phosphorylation in human skeletal muscle  

OpenAIRE

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, regulatin...

Jessen, Niels; An, Ding; Lihn, Aina S.; Nygren, Jonas; Hirshman, Michael F.; Thorell, Anders; Goodyear, Laurie J.

2011-01-01

222

Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint  

Energy Technology Data Exchange (ETDEWEB)

To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.

McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.

2012-06-01

223

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 ± 2.4, M-value 4.3 ± 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 ± 0.4 kg weight loss (P <0.001) and a significant increase in insulin sensitivity (M value 5.6 ± 0.6), but surprisingly, there was no effect on expression or phosphorylation of any of the muscle-signaling proteins. Exercise increased muscle AMPK?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

224

[Chemical structural features and anti-complementary activity of polysaccharide HPS1-D from Hedysarum polybotrys].  

Science.gov (United States)

HPS1-D, an active polysaccharide,was isolated and purified from Hedysarum polybotrys. HPS1-D was obtained after treated with Savage method and H2O2, and purified with DEAE-cellulose 52 and Sephadex G-100 gel filtration chromatography. Then physicochemical property analysis, GC, methylation, partial acid hydrolysis, and NMR method were used to study chemical structural of HPS1-D. The conformation was primarily analyzed with GPC-MALLS method and Congo red reaction. The anti-complementary activity of HPS1-D was evaluated with the hemolysis assay. HPS1-D was a heteropolysaccharide and consisted of D-glucose, L-arabinose, (7.2:1.3). HPS1-D proved to be a neutral sugar, with 1, 4-and 1, 4, 6-alpha-D-glucopyranosyl residues in backbone ,and 1, 5-and 1, 3, 5-alpha-L-arabinofuranosyl residues in branches. HPS1-D has a random coil state conformation with monodisperse mass distribution in 0.9% NaCl solution. And HPS1-D had triple-helix conformation in concentrate of NaOH solution. Anti-complementary activity of HPS1-D was closed to its positive control heparin. PMID:24754175

Yang, Tao; Guo, Long; Li, Can; Yang, Ying-Lai; Feng, Shi-Lan

2014-01-01

225

Comments on the Bifurcation Structure of 1D Maps  

DEFF Research Database (Denmark)

The paper presents a complementary view on some of the phenomena related to the bifurcation structure of unimodal maps. An approximate renormalization theory for the period-doubling cascade is developed, and a mapping procedure is established that accounts directly for the box-within-a-box structure of the total bifurcation set. This presents a picture in which the homoclinic orbit bifurcations act as a skeleton for the bifurcational set. At the same time, experimental results on continued subharmonic generation for piezoelectrically amplified sound waves, predating the Feigenbaum theory, are called into attention.

Belykh, V.N.; Mosekilde, Erik

1997-01-01

226

Rotated multifractal network generator  

International Nuclear Information System (INIS)

The recently introduced multifractal network generator (MFNG), has been shown to provide a simple and flexible tool for creating random graphs with very diverse features. The MFNG is based on multifractal measures embedded in 2d, leading also to isolated nodes, whose number is relatively low for realistic cases, but may become dominant in the limiting case of infinitely large network sizes. Here we discuss the relation between this effect and the information dimension for the 1d projection of the link probability measure (LPM), and argue that the node isolation can be avoided by a simple transformation of the LPM based on rotation

227

Rotated multifractal network generator  

CERN Document Server

The recently introduced multifractal network generator (MFNG), has been shown to provide a simple and flexible tool for creating random graphs with very diverse features. The MFNG is based on multifractal measures embedded in 2d, leading also to isolated nodes, whose number is relatively low for realistic cases, but may become dominant in the limiting case of infinitely large network sizes. Here we discuss the relation between this effect and the information dimension for the 1d projection of the link probability measure (LPM), and argue that the node isolation can be avoided by a simple transformation of the LPM based on rotation.

Palla, G; Vicsek, T

2011-01-01

228

Rotated multifractal network generator  

Science.gov (United States)

The recently introduced multifractal network generator (MFNG), has been shown to provide a simple and flexible tool for creating random graphs with very diverse features. The MFNG is based on multifractal measures embedded in 2d, leading also to isolated nodes, whose number is relatively low for realistic cases, but may become dominant in the limiting case of infinitely large network sizes. Here we discuss the relation between this effect and the information dimension for the 1d projection of the link probability measure (LPM), and argue that the node isolation can be avoided by a simple transformation of the LPM based on rotation.

Palla, Gergely; Pollner, Péter; Vicsek, Tamás

2011-02-01

229

The organic anion transport polypeptide 1d1 (Oatp1d1) mediates hepatocellular uptake of phalloidin and microcystin into skate liver  

International Nuclear Information System (INIS)

Organic anion transporting polypeptides (rodent Oatp; human OATP) mediate cellular uptake of numerous organic compounds including xenobiotic toxins into mammalian hepatocytes. In the little skate Leucoraja erinacea a liver-specific Oatp (Oatp1d1, also called sOatp) has been identified and suggested to represent an evolutionarily ancient precursor of the mammalian liver OATP1B1 (human), Oatp1b2 (rat), and OATP1B3 (human). The present study tested whether Oatp1d1 shares functional transport activity of the xenobiotic oligopeptide toxins phalloidin and microcystin with the mammalian liver Oatps/OATPs. The phalloidin analogue [3H]-demethylphalloin was taken up into skate hepatocytes with high affinity (Km ? 0.4 ?M), and uptake could be inhibited by phalloidin and a variety of typical Oatp/OATP substrates such as bromosulfophthalein, bile salts, estrone-3-sulfate, cyclosporine A and high concentrations of microcystin-LR (Ki ? 150 ?M). When expressed in Xenopus laevis oocytes Oatp1d1 increased uptake of demethylphalloin (Km ? 2.2 ?M) and microcystin-LR (Km ? 27 ?M) 2- to 3-fold over water-injected oocytes, whereas the alternative skate liver organic anion transporter, the dimeric Ost?/?, exhibited no phalloidin and only minor microcystin-LR transport. Also, the closest mammalian Oatp1d1 orthologue, the human brain and testis OATP1C1, did not show any phalloidin transport activity. These results demonstrate that the evolutionarily ancient Oatp1d1 is ionarily ancient Oatp1d1 is able to mediate uptake of cyclic oligopeptide toxins into skate liver. The findings support the notion that Oatp1d1 is a precursor of the liver-specific mammalian Oatps/OATPs and that its transport properties are closely associated with certain forms of toxic liver injury such as for example protein phosphatase inhibition by the water-borne toxin microcystin

230

Treatment time reduction for large thermal lesions by using a multiple 1D ultrasound phased array system  

International Nuclear Information System (INIS)

To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the two methods, power optimization and acoustic window enlargement, for reducing power accumulation in the near field are combined to investigate the feasibility of continuously heating a large target region (maximally 3.2 x 3.2 x 3.2 cm3). A multiple 1D ultrasound phased array system generates the foci to scan the target region. Simulations show that the target region can be successfully heated without cooling and no near-field heating occurs. Moreover, due to the fact that there is no cooling time during the heating sessions, the total treatment time is significantly reduced to only several minutes, compared to the existing several hours

231

Treatment time reduction for large thermal lesions by using a multiple 1D ultrasound phased array system  

Science.gov (United States)

To generate large thermal lesions in ultrasound thermal therapy, cooling intermissions are usually introduced during the treatment to prevent near-field heating, which leads to a long treatment time. A possible strategy to shorten the total treatment time is to eliminate the cooling intermissions. In this study, the two methods, power optimization and acoustic window enlargement, for reducing power accumulation in the near field are combined to investigate the feasibility of continuously heating a large target region (maximally 3.2 × 3.2 × 3.2 cm3). A multiple 1D ultrasound phased array system generates the foci to scan the target region. Simulations show that the target region can be successfully heated without cooling and no near-field heating occurs. Moreover, due to the fact that there is no cooling time during the heating sessions, the total treatment time is significantly reduced to only several minutes, compared to the existing several hours.

Liu, Hao-Li; Chen, Yung-Yaw; Yen, Jia-Yush; Lin, Win-Li

2003-05-01

232

HELIOS-CR - A 1-D radiation-magnetohydrodynamics code with inline atomic kinetics modeling  

International Nuclear Information System (INIS)

HELIOS-CR is a user-oriented 1D radiation-magnetohydrodynamics code to simulate the dynamic evolution of laser-produced plasmas and z-pinch plasmas. It includes an in-line collisional-radiative (CR) model for computing non-LTE atomic level populations at each time step of the hydrodynamics simulation. HELIOS-CR has been designed for ease of use, and is well-suited for experimentalists, as well as graduate and undergraduate student researchers. The energy equations employed include models for laser energy deposition, radiation from external sources, and high-current discharges. Radiative transport can be calculated using either a multi-frequency flux-limited diffusion model, or a multi-frequency, multi-angle short characteristics model. HELIOS-CR supports the use of SESAME equation of state (EOS) tables, PROPACEOS EOS/multi-group opacity data tables, and non-LTE plasma properties computed using the inline CR modeling. Time-, space-, and frequency-dependent results from HELIOS-CR calculations are readily displayed with the HydroPLOT graphics tool. In addition, the results of HELIOS simulations can be post-processed using the SPECT3D Imaging and Spectral Analysis Suite to generate images and spectra that can be directly compared with experimental measurements. The HELIOS-CR package runs on Windows, Linux, and Mac OSX platforms, and includes online documentation. We will discuss the major features of HELIOS-CR, and present example results from simulations results from simulations

233

The role of river flow and tidal asymmetry on 1-D estuarine morphodynamics  

Science.gov (United States)

research efforts have been devoted to understanding estuarine morphodynamics under tidal forcing. However, the impact of river discharge on estuarine morphodynamics is insufficiently examined. Inspired by the Yangtze Estuary, this work explores the morphodynamic impact of river discharge in a 560 km long tidal basin based on a 1-D model (Delft3D). The model considers total load sediment transport and employs a morphodynamic updating scheme to achieve long-term morphodynamic evolution. We analyze the role of Stokes drift, tidal asymmetry, and river discharge in generating tidal residual sediment transport. Model results suggest that morphodynamic equilibrium is approached within millennia by vanishing spatial gradients of tidal residual sediment transport. We find that the interaction between ebb-directed Stokes return flow/river flow with tides is an important mechanism that flushes river-supplied sediment seaward. Increasing river discharge does not induce continuously eroded or accreted equilibrium bed profiles because of the balance between riverine sediment supply and sediment flushing to the sea. An intermediate threshold river discharge can be defined which leads to a deepest equilibrium bed profile. As a result, the shape (concavity or convexity) of the equilibrium bed profiles will adapt with the magnitude of river discharge. Overall, this study reveals the significant role of river discharge in controlling estuarine morphodynamics by supplying sediment and reinforcing ebb-directed residual sediment transport.

Guo, L.; Wegen, M.; Roelvink, J. A.; He, Q.

2014-11-01

234

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

235

Quasi-3D resistivity gridding from large AEM datasets of 1D geophysical models: a step toward enhanced geological interpretation  

Science.gov (United States)

With the advent of airborne electromagnetic (AEM), large areas can be investigated with a high density of geophysical soundings: flight lines are typically tens of kilometers long with a sounding for each 3-30m and line spacing of 200-1000m. AEM soundings are usually inverted to 1D layered-earth resistivity models, possibly with spatially constrained inversion algorithms which take into account neighboring soundings for the inversion and provide a more consistent set of resistivity models. But as 3D inversion of AEM data remains unsolved, the visualization of these rich datasets representing 3D geological structures is often limited to 2D cross-sections and thematic maps. We present a new methodology to tackle the need for 3D visualization of resistivity structures. Our method is based on the regional 2D interpolation of the geophysical model parameters: layer thicknesses and resistivities obtained from geophysical inversion are mapped in the 2D horizontal space. From these maps, a 3D irregular mesh is generated according to the geometry of the 1D geophysical models. The cells constituting the 3D grid are irregular hexahedra which accurately follow the geometry of geophysical interfaces. This produces very fine, but memory-light 3D grids of resistivity at low computational cost. The 3D grid is then written to VTK standards and can be read with a powerful 3D visualization software which is freely available. The error from inversion, expressed as the standard deviation of model parameters, is used to weight each sounding during interpolation, which gives more importance to 1D models with a low residual between the sounding data and the 1D geophysical model. The propagation of uncertainty during interpolation is quantified and expressed as a standard deviation factor in each cell of the model. This is made possible by the use of kriging for interpolation, and allows the extraction of regions of the 3D grid which match given quality criteria. The reliability of the 3D grid, and its ability to represent heterogeneities present in the 1D models depend on the resolution of the 3D grid and the quality of the interpolation. The 3D grid is provided with a quantification of the loss of detail due to gridding process. The method is largely illustrated with a case study based on a SkyTEM airborne transient electromagnetic geophysical survey conducted on two islands in Galápagos Archipelago in 2006. The 3D resistivity grid of this extensive survey provides unprecedented images. Resistivity thresholds applied to the 3D grid allows the delineation of 3D geological bodies, providing unprecedented insights into the hydrogeology and geological structures of these volcanic islands.

Pryet, A.; Ramm, J.; Auken, E.; Chilès, J.; Violette, S.; D'Ozouville, N.; Deffontaines, B.

2010-12-01

236

On asymptotic stability in energy space of ground states of NLS in 1D  

CERN Document Server

We transpose work by T.Mizumachi to prove smoothing estimates for dispersive solutions of the linearization at a ground state of a Nonlinear Schr\\"odinger equation (NLS) in 1D. As an application we extend to dimension 1D a result on asymptotic stability of ground states of NLS proved by Cuccagna & Mizumachi for dimensions $\\ge 3$

Cuccagna, Scipio

2007-01-01

237

A new 3D consistent 1D group constants representation scheme  

International Nuclear Information System (INIS)

A 1D group constant representation scheme employing tables having independent variables of control rod tip position, fuel temperature, moderator density, and boron concentration is presented. This table functionalizes the current conservation factors (CCF) as well as the conventional 1D collapsed group constants. To test the 1D kinetics model with this 1D group constants representation scheme, steady state and transient calculations for the NEACRP A1 benchmark problem and a SMART bank withdrawal event are performed and compared with 3D reference values. Results show that the errors in k-eff are reduced to about one tenth when using CCF without significant computational overheads. The error in the power distribution is decreased to the range of one fifth or tenth at steady state calculation. During transient, the 1D result shows much closer results to the 3D values than the conventional linear 1D group constants representation. It is expected that the proposed 1D kinetics model with the 1D group constants representation scheme can be used in many practical applications requiring fast execution such as operator supporting system and coupled real time simulation of the system with significantly enhanced solution fidelity

238

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

239

TBC1D1 reduces palmitate oxidation by inhibiting ?-HAD activity in skeletal muscle.  

Science.gov (United States)

In skeletal muscle the Rab-GTPase-activating protein TBC1D1 has been implicated in the regulation of fatty acid oxidation by an unknown mechanism. We determined whether TBC1D1 altered fatty acid utilization via changes in protein-mediated fatty acid transport and/or selected enzymes regulating mitochondrial fatty acid oxidation. We also determined the effects of TBC1D1 on glucose transport and oxidation. Electrotransfection of mouse soleus muscles with TBC1D1 cDNA increased TBC1D1 protein after 2 wk (PGLUT4 and glucose transport. The reductions in TBC1D1-mediated fatty acid oxidation could not be attributed to changes in the transporter FAT/CD36, muscle mitochondrial content, CPT1 expression or the expression and phosphorylation of AS160, acetyl-CoA carboxylase, or AMPK. However, TBC1D1 overexpression reduced ?-HAD enzyme activity (-18%, P<0.05). In conclusion, TBC1D1-mediated reduction of muscle fatty acid oxidation appears to occur via inhibition of ?-HAD activity. PMID:25163918

Maher, A C; McFarlan, J; Lally, J; Snook, L A; Bonen, A

2014-11-01

240

Identification of RAPD Marker for Chromosome 1D of Common Wheat  

Directory of Open Access Journals (Sweden)

Full Text Available Development of genetically compensating nullisomic-tetrasomic and ditelosomic lines of commonwheat (Triticum aestivum L. have been widely used to construct high density genetic maps of homoeologouswheat chromosomes. During present research, easier, cheaper and quicker procedure of Polymerase ChainReaction (PCR was used to map Randomly Amplified Polymorphic DNA primers on chromosome 1D ofcommon wheat. Genomic DNA was isolated from two genetic stocks of wheat cultivar Chinese Spring viz;NT-1D1B and NT-2A2B. PCR were conducted using RAPD primers GLC-07 and GLC-11. RAPD primerGLC-11 amplified a polymorphic allele of approximately 500 bp, which was present in NT-2A2B (used aspositive control but was absent in NT-1D1B indicating that the locus is present on chromosome 1D of commonwheat. Hence this marker (GLC-11 can reliably be used to keep track of chromosome 1D of hexaploid wheat.

Imtiaz Ahmad Khan

2010-04-01

241

Mapping of the serotonin 5-HT{sub 1D{alpha}} autoreceptor gene (HTR1D) on chromosome 1 using a silent polymorphism in the coding region  

Energy Technology Data Exchange (ETDEWEB)

Serotonin (5-HT){sub ID} receptors are 5-HT release-regulating autoreceptors in the human brain. Abnormalities in brain 5-HT function have been hypothesized in the pathophysiology of various psychiatric disorders, including obsessive-compulsive disorder, autism, mood disorders, eating disorders, impulsive violent behavior, and alcoholism. Thus, mutations occurring in 5-HT autoreceptors may cause or increase the vulnerability to any of these conditions. 5-HT{sub 1D{alpha}} and 5-HT{sub 1D{Beta}} subtypes have been previously localized to chromosomes 1p36.3-p34.3 and 6q13, respectively, using rodent-human hybrids and in situ localization. In this communication, we report the detection of a 5-HT{sub 1D{alpha}} receptor gene polymorphism by single strand conformation polymorphism (SSCP) analysis of the coding sequence. The polymorphism was used for fine scale linkage mapping of 5-HT{sub 1D{alpha}} on chromosome 1. This polymorphism should also be useful for linkage studies in populations and in families. Our analysis also demonstrates that functionally significant coding sequence variants of the 5-HT{sub 1D{alpha}} are probably not abundant either among alcoholics or in the general population. 14 refs., 1 fig., 1 tab.

Ozaki, N.; Lappalainen, J.; Linnoila, M. [National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (United States)] [and others

1995-04-24

242

Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation  

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

243

Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation  

International Nuclear Information System (INIS)

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

244

THE STEREOCHEMISTRY OF THE O(1D)+N2O-]NO+NO REACTION VIA VELOCITY-ALIGNED PHOTOFRAGMENT DYNAMICS  

OpenAIRE

Velocity-aligned, superthermal O(1D) atoms generated via the photodissociation of N2O have been employed to investigate the stereodynamics of the title reaction. The power of this experimental technique, when coupled with Doppler-resolved, polarized laser-induced fluorescence probing of the reaction products, is demonstrated by reference to the specific reaction channel leading to NO(v?=0)+NO(v?=16,17), which is shown to proceed via direct stripping dynamics. Furthermore, the observed pro...

Brouard, M.; Duxon, S.; Enriquez, P.; Simons, J.

1992-01-01

245

The primate-specific protein TBC1D3 is required for optimal macropinocytosis in a novel ARF6-dependent pathway.  

OpenAIRE

The generation of novel genes and proteins throughout evolution has been proposed to occur as a result of whole genome and gene duplications, exon shuffling, and retrotransposition events. The analysis of such genes might thus shed light into the functional complexity associated with highly evolved species. One such case is represented by TBC1D3, a primate-specific gene, harboring a TBC domain. Because TBC domains encode Rab-specific GAP activities, TBC-containing proteins are predicted to pl...

Frittoli, Emanuela; Palamidessi, Andrea; Pizzigoni, Alessandro; Lanzetti, Letizia; Garre?, Massimiliano; Troglio, Flavia; Troilo, Albino; Fukuda, Mitsunori; Di Fiore, Pier Paolo; Scita, Giorgio; Confalonieri, Stefano

2008-01-01

246

Non-inductive electric current generation with the Alfven waves  

International Nuclear Information System (INIS)

Non-inductive current generation by means of radio frequency waves is studied using one-dimensional (1D) quasilinear equations. The main results obtained in this thesis are the general expressions for the current generated, for the efficiency of current generation and for the critical power - the lowest power required for current saturation. (M.W.O.)

247

Alniditan, a new 5-hydroxytryptamine1D agonist and migraine-abortive agent: ligand-binding properties of human 5-hydroxytryptamine1D alpha, human 5-hydroxytryptamine1D beta, and calf 5-hydroxytryptamine1D receptors investigated with [3H]5-hydroxytryptamine and [3H]alniditan.  

Science.gov (United States)

Alniditan is a new migraine-abortive agent. It is a benzopyran derivative and therefore structurally unrelated to sumatriptan and other indole-derivatives and to ergoline derivatives. The action of sumatriptan is thought to be mediated by 5-hydroxytryptamine (5-HT)1D-type receptors. We investigated the receptor-binding profile in vitro of alniditan compared with sumatriptan and dihydroergotamine for 28 neurotransmitter receptor subtypes, several receptors for peptides and lipid-derived factors, ion channel-binding sites, and monoamine transporters. Alniditan revealed nanomolar affinity for calf substantia nigra 5-HT1D and for cloned h5-HT1D alpha, h5-HT1D beta and h5-HT1A receptors (Ki = 0.8, 0.4, 1.1, and 3.8 nM, respectively). Alniditan was more potent than sumatriptan at 5-HT1D-type and 5-HT1A receptors. Alniditan showed moderate-to-low or no affinity for other investigated receptors; sumatriptan showed additional binding to 5-HT1F receptors. Dihydroergotamine had a much broader profile with high affinity for several 5-HT, adrenergic and dopaminergic receptors. In signal transduction assays using cells expressing recombinant h5-HT1D alpha, h5-HT1D beta, or h5-HT1A receptors, alniditan (like 5-HT) was a full agonist for inhibition of stimulated adenylyl cyclase (IC50 = 1.1, 1.3, and 74 nM, respectively, for alniditan). Therefore, in functional assays, the potency of alniditan was much higher at 5-HT1D receptors than at 5-HT1A receptors. We further compared the properties of [3H]alniditan, as a new radioligand for 5-HT1D-type receptors, with those of [3H]5-HT in membrane preparations of calf substantia nigra, C6 glioma cells expressing h5-HT1D alpha, and L929 cells expressing h5-HT1D beta receptors. [3H]Alniditan revealed very rapid association and dissociation binding kinetics and showed slightly higher affinity (Kd = 1-2 nM) than [3H]5-HT. We investigated 25 compounds for inhibition of [3H]alniditan and [3H]5-HT binding in the three membrane preparations; Ki values of the radioligands were largely similar, although some subtle differences appeared. Most compounds did not differentiate between 5-HT1D alpha and 5-HT1D beta receptors, except methysergide, ritanserin, ocaperidone, risperidone, and ketanserin, which showed 10-60-fold higher affinity for the 5-HT1D alpha receptor. The Ki values of the compounds obtained with 5-HT1D receptors in calf substantia nigra indicated that these receptors are of the 5-HT1D beta-type. We demonstrated that alniditan is a potent agonist at h5-HT1D alpha and h5-HT1D beta receptors; its properties probably underlie its cranial vasoconstrictive and antimigraine properties. PMID:8967979

Leysen, J E; Gommeren, W; Heylen, L; Luyten, W H; Van de Weyer, I; Vanhoenacker, P; Haegeman, G; Schotte, A; Van Gompel, P; Wouters, R; Lesage, A S

1996-12-01

248

Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids  

International Nuclear Information System (INIS)

One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better sed taurine concentrations produce better scores plot subpopulation cluster resolution.

249

Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids  

Energy Technology Data Exchange (ETDEWEB)

One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.

Sandusky, Peter [Eckerd College, Department of Chemistry (United States); Appiah-Amponsah, Emmanuel; Raftery, Daniel, E-mail: raftery@purdue.edu [Purdue University, Department of Chemistry (United States)

2011-04-15

250

Tbc1d15-17 regulates synaptic development at the Drosophila neuromuscular junction.  

Science.gov (United States)

Members of the Tre-2/Bub2/Cdc16 (TBC) family of proteins are believed to function as GTPase-activating proteins (GAPs) for Rab GTPases, which play pivotal roles in intracellular membrane trafficking. Although membrane trafficking is fundamental to neuronal morphogenesis and function, the roles of TBC-family Rab GAPs have been poorly characterized in the nervous system. In this paper, we provide genetic evidence that Tbc1d15-17, the Drosophila homolog of mammalian Rab7-GAP TBC1d15, is required for normal presynaptic growth and postsynaptic organization at the neuromuscular junction (NMJ). A loss-of-function mutation in Tbc1d15-17 or its presynaptic knockdown leads to an increase in synaptic bouton number and NMJ length. Tbc1d15-17 mutants are also defective in the distribution of the postsynaptic scaffold Discs-large (Dlg) and in the level of the postsynaptic glutamate subunit GluRIIA. These postsynaptic phenotypes are recapitulated by postsynaptic knockdown of Tbc1d15-17. We also show that presynaptic overexpression of a constitutively active Rab7 mutant in a wild-type background causes a synaptic overgrowth phenotype resembling that of Tbc1d15-17 mutants, while a dominant-negative form of Rab7 has the opposite effect. Together, our findings establish a novel role for Tbc1d15-17 and its potential substrate Rab7 in regulating synaptic development. PMID:23812537

Lee, Min-Jung; Jang, Sooyeon; Nahm, Minyeop; Yoon, Jin-Ho; Lee, Seungbok

2013-08-01

251

Contraction regulates site-specific phosphorylation of TBC1D1 in skeletal muscle  

OpenAIRE

TBC1D1 (tre-2/USP6, BUB2, cdc16 domain family member 1) is a Rab-GAP (GTPase-activating protein) that is highly expressed in skeletal muscle, but little is known about TBC1D1 regulation and function. We studied TBC1D1 phosphorylation on three predicted AMPK (AMP-activated protein kinase) phosphorylation sites (Ser231, Ser660 and Ser700) and one predicted Akt phosphorylation site (Thr590) in control mice, AMPK?2 inactive transgenic mice (AMPK?2i TG) and Akt2-knockout mice (Akt2 KO). Muscle c...

Vichaiwong, Kanokwan; Purohit, Suneet; An, Ding; Toyoda, Taro; Jessen, Niels; Hirshman, Michael f; Goodyear, Laurie j

2010-01-01

252

The behaviour of 1D CuI crystal@SWNT nanocomposite under electron irradiation  

OpenAIRE

Nanocomposite 1D CuI crystal@SWNT was obtained by the growth of CuI nanocrystals inside single walled carbon nanotubes (SWNTs) using the capillary technique. High resolution transmission electron microscopy (HRTEM) investigation of the atomic structure of 1D CuI crystals revealed two types of 1D CuI crystals: with growth direction and > relative to the bulk hexagonal CuI stucture. EM images were recorded and atomic models of the structure were proposed. According to th...

Hutchison, Jl; Grobert, N.; Zakalyukin, Rm; Eliseev, Aa; Chernisheva, Mv; Kumnskov, As; Grigoriev, Yv; Krestinin, Av; Freitag, B.; Kiselev, Na

2008-01-01

253

A conservative strategy to couple 1D and 2D models for shallow water flow simulation  

OpenAIRE

A 1D–2D coupled numerical model is presented in this work. 1D and 2D models are formulated using a conservative upwind cell-centred finite volume scheme. The discretization is based on cross-sections for the 1D model and with triangular unstructured grid for the 2D model. The resulting element of discretization for the coupled model is analysed and two different coupling techniques based on mass conservation and mass and momentum conservation respectively are explored, considering both fron...

Morales-herna?ndez, M.; Garci?a-navarro, P.; Burguete Tolosa, Javier; Brufau, P.

2013-01-01

254

Thermal characterization of large size lithium-ion pouch cell based on 1d electro-thermal model  

Science.gov (United States)

Thermal management is one of the key factors to keep lithium-ion cells in optimum electrical performance, under safe working conditions and into a reasonably low ageing process. This issue is becoming particularly relevant due to the heterogeneous heat generation along the cell. Cell working temperature is determined by ambient temperature, heat generation and evacuation capacity. Therefore, thermal management is established by: i) the intrinsic thermal properties (heat capacity & thermal conductivity) and ii) the heat generation electro-thermal parameters (internal resistance, open circuit voltage & entropic factor). In this research, different methods - calculated and experimental - are used to characterize the main heat properties of a 14Ah -LiFePO4/graphite-commercial large sizes pouch cell. In order to evaluate the accuracy of methods, two comparisons were performed. First, Newman heat generation estimations were compared with experimental heat measurements. Secondly, empirical thermal cell behaviour was match with 1D electro-thermal model response. Finally, considering the results, the most adequate methodology to evaluate the key thermal parameters of a large size Lithium-ion pouch cell are proposed to be: i) pulse method for internal resistance, ii)heat loss method for entropic factor; and iii)experimental measurement (ARC calorimeter and C-177-97 standard method) for heat capacity and thermal conductivity.

Vertiz, G.; Oyarbide, M.; Macicior, H.; Miguel, O.; Cantero, I.; Fernandez de Arroiabe, P.; Ulacia, I.

2014-12-01

255

Two Step Procedure Using a 1-D Slab Spectral Geometry in a Pebble Bed Reactor Core Analysis  

Energy Technology Data Exchange (ETDEWEB)

A strong spectral interaction between the core and the reflector has been one of the main concerns in the analysis of pebble bed reactor cores. To resolve this problem, VSOP adopted iteration between the spectrum calculation in a spectral zone and the global core calculation. In VSOP, the whole problem domain is divided into many spectral zones in which the fine group spectrum is calculated using bucklings for fast groups and albedos for thermal groups from the global core calculation. The resulting spectrum in each spectral zone is used to generate broad group cross sections of the spectral zone for the global core calculation. In this paper, we demonstrate a two step procedure in a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. The equivalent cross sections generated in this way include the effect of the spectral interaction between the core and the reflector. In the second step, we perform a diffusion calculation using the equivalent cross sections generated in the first step. A simple benchmark problem derived from the PMBR-400 Reactor was introduced to verify this approach. We compared the two step solutions with the Monte Carlo (MC) solutions for the problem.

Lee, Hyun Chul; Kim, Kang Seog; Noh, Jae Man; Joo, Hyung Kook [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

256

Two Step Procedure Using a 1-D Slab Spectral Geometry in a Pebble Bed Reactor Core Analysis  

International Nuclear Information System (INIS)

A strong spectral interaction between the core and the reflector has been one of the main concerns in the analysis of pebble bed reactor cores. To resolve this problem, VSOP adopted iteration between the spectrum calculation in a spectral zone and the global core calculation. In VSOP, the whole problem domain is divided into many spectral zones in which the fine group spectrum is calculated using bucklings for fast groups and albedos for thermal groups from the global core calculation. The resulting spectrum in each spectral zone is used to generate broad group cross sections of the spectral zone for the global core calculation. In this paper, we demonstrate a two step procedure in a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. The equivalent cross sections generated in this way include the effect of the spectral interaction between the core and the reflector. In the second step, we perform a diffusion calculation using the equivalent cross sections generated in the first step. A simple benchmark problem derived from the PMBR-400 Reactor was introduced to verify this approach. We compared the two step solutions with the Monte Carlo (MC) solutions for the problem

257

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

Science.gov (United States)

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

258

Expression, phosphorylation and function of the Rab-GTPase activating protein TBC1D1 in pancreatic beta-cells  

OpenAIRE

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 ...

Rutti Roch, Sabine; Arous, Caroline; Nica, Alexandra C.; Kanzaki, Makoto; Halban, Philippe A.; Bouzakri, Karim

2014-01-01

259

Overexpression of AtDREB1D transcription factor improves drought tolerance in soybean.  

Science.gov (United States)

Drought is one of the major abiotic stresses that affect productivity in soybean (Glycine max L.) Several genes induced by drought stress include functional genes and regulatory transcription factors. The Arabidopsis thaliana DREB1D transcription factor driven by the constitutive and ABA-inducible promoters was introduced into soybean through Agrobacterium tumefaciens-mediated gene transfer. Several transgenic lines were generated and molecular analysis was performed to confirm transgene integration. Transgenic plants with an ABA-inducible promoter showed a 1.5- to two-fold increase of transgene expression under severe stress conditions. Under well-watered conditions, transgenic plants with constitutive and ABA-inducible promoters showed reduced total leaf area and shoot biomass compared to non-transgenic plants. No significant differences in root length or root biomass were observed between transgenic and non-transgenic plants under non-stress conditions. When subjected to gradual water deficit, transgenic plants maintained higher relative water content because the transgenic lines used water more slowly as a result of reduced total leaf area. This caused them to wilt slower than non-transgenic plants. Transgenic plants showed differential drought tolerance responses with a significantly higher survival rate compared to non-transgenic plants when subjected to comparable severe water-deficit conditions. Moreover, the transgenic plants also showed improved drought tolerance by maintaining 17-24 % greater leaf cell membrane stability compared to non-transgenic plants. The results demonstrate the feasibility of engineering soybean for enhanced drought tolerance by expressing stress-responsive genes. PMID:25192890

Guttikonda, Satish K; Valliyodan, Babu; Neelakandan, Anjanasree K; Tran, Lam-Son Phan; Kumar, Rajesh; Quach, Truyen N; Voothuluru, Priyamvada; Gutierrez-Gonzalez, Juan J; Aldrich, Donavan L; Pallardy, Stephen G; Sharp, Robert E; Ho, Tuan-Hua David; Nguyen, Henry T

2014-12-01

260

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

CERN Document Server

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

261

The Boundary Element Formulation of the 1-Group, 1-D Nodal Equations  

International Nuclear Information System (INIS)

A boundary element method is developed for the 1-D nodal diffusion equation in cylindrical geometry. This method retains the matrix qualities of the nodal formulation while providing an accurate computational benchmark for evaluating reactor analysis codes

262

Estimación de la vulnerabilidad de acuíferos mediante un modelo cuantitativo - Hydrus 1D  

OpenAIRE

Ríos Rojas, Liliana and Vélez Otálvaro, María Victoria (2007) Estimación de la vulnerabilidad de acuíferos mediante un modelo cuantitativo - Hydrus 1D. Avances en Recursos Hidráulicos (15). pp. 23-34. ISSN 0121-5701

Ri?os Rojas, Liliana; Ve?lez Ota?lvaro, Mari?a Victoria

2007-01-01

263

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes; L'analyse des sismogrammes historiques: un outil important pour l'evaluation de l'alea sismique. Etudes de cas de tremblements de terre en France et en Italie  

Energy Technology Data Exchange (ETDEWEB)

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)

Pino, N.A. [Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Via Diocleziano 328, 80124 Napoli (Italy)

2011-06-15

264

1D model for the dynamics and expansion of elongated Bose-Einstein condensates  

OpenAIRE

We present a 1D effective model for the evolution of a cigar-shaped Bose-Einstein condensate in time dependent potentials whose radial component is harmonic. We apply this model to investigate the dynamics and expansion of condensates in 1D optical lattices, by comparing our predictions with recent experimental data and theoretical results. We also discuss negative-mass effects which could be probed during the expansion of a condensate moving in an optical lattice.

Massignan, Pietro; Modugno, Michele

2002-01-01

265

User's manual of the REFLA-1D/MODE4 reflood thermo-hydrodynamic analysis code  

International Nuclear Information System (INIS)

REFLA-1D/MODE4 code has been developed by incorporating local power effect model and fuel temperature profile effect model into REFLA-1D/MODE3 code. This code can calculate the temperature transient of local rod by considering radial power profile effect in core and simulate the thermal characteristics of the nuclear fuel rod. This manual describes the outline of incorporated models, modification of the code with incorporating models and provides application information required to utilize the code. (author)

266

Two-loop effective action of O(N) spin models in 1/D expansion  

Energy Technology Data Exchange (ETDEWEB)

We calculate the two-loop effective action of O(N) spin models on the lattice in a 1/D expansion to order 1/D/sup 2/. The resulting free energy depends on ..beta.. = 1/T and the order parameter PHI. It matches the high and low temperature regimes and is quite reliable close to the phase transition where is has a simple Landau expansion.

Matsui, T.; Kleinert, H.; Ami, S.

1984-08-09

267

Exercise and Insulin: Convergence or Divergence at AS160 and TBC1D1?  

OpenAIRE

Akt substrate of 160 kDa (called AS160 or TBC1D4) and TBC1D1, Rab GTPase activating proteins that regulate glucose transport, become phosphorylated with exercise- or insulin-stimulation. Evidence suggests that this convergence may prove to be imperfect, and each stimulus will produce a unique phospho-signature, providing a plausible mechanism for their apparently unique and overlapping roles in exercise- and insulin-stimulated glucose transport.

Cartee, Gregory D.; Funai, Katsuhiko

2009-01-01

268

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

OpenAIRE

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 s...

Prude?ncio, Thiago

2013-01-01

269

Alternative spliced CD1d transcripts in human bronchial epithelial cells  

OpenAIRE

CD1d is a MHC I like molecule which presents glycolipid to natural killer T (NKT) cells, a group of cells with diverse but critical immune regulatory functions in the immune system. These cells are required for optimal defence against bacterial, viral, protozoan, and fungal infections, and control of immune-pathology and autoimmune diseases. CD1d is expressed on antigen presenting cells but also found on some non-haematopoietic cells. However, it has not been observed on bronchial epithelium,...

Benam, Kh; Kok, Wl; Mcmichael, Aj; Ho, Lp

2011-01-01

270

Transparent Conducting Electrodes based on 1D and 2D Ag Nanogratings for Organic Photovoltaics  

OpenAIRE

The optical and electrical properties of optically-thin one-dimensional (1D) Ag nanogratings and two-dimensional (2D) Ag nanogrids are studied, and their use as transparent electrodes in organic photovoltaics are explored. A large broadband and polarization-insensitive optical absorption enhancement in the organic light-harvesting layers is theoretically and numerically demonstrated using either single-layer 2D Ag nanogrids or two perpendicular 1D Ag nanogratings, and is att...

Zeng, Beibei; Kafafi, Zakya H.; Bartoli, Filbert J.

2014-01-01

271

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

OpenAIRE

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...

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

2010-01-01

272

Analysis of the Arkuszewski benchmark by 1-D supercell, 2-D collision probability and Monte Carlo methods  

International Nuclear Information System (INIS)

The Arkuszweski benchmark is a square lattice assembly with 8 uranium pins surrounding a Gd loaded fuel pin. For this problem details of K-infinity, absorption and production rates at zero burnup alone are required to be computed. Results from Monte Carlo method using a cross section library based on ENDF/B-V data are available which can be treated as reference values. We have used 69 group WIMS library. Cross sections for Gd isotopes were generated here from their resonance parameters. The above benchmark was solved by a 1-D supercell approach, a 2-D collision probability method and a Monte Carlo method. This paper discusses the results obtained using these three methods. (author). 5 refs, 1 fig., 5 tabs

273

Soluble 1D coordination polymers based on dendron-functionalized bispyridine ligand for linking between immobilized molecules on substrates.  

Science.gov (United States)

As a monomeric ligand for a soluble 1D coordination polymer, a benzyl-ether based dendrimer having a rigid 4,4'-bispyridine ligand at the focal point has been synthesized and the coordination chemistry with Pd(II) investigated by nuclear magnetic resonance, ultraviolet-visible and fluorescence spectroscopies, gel permeation chromatography measurement, and X-ray photoelectron spectroscopy. As a result, it was found that the synthesized dendrimer forms a stable, soluble Pd(II) coordination polymer with rough estimation of degree of polymerization of 10 in organic solvents. Furthermore, through the coordination polymer we attempted to link fourth-generation poly(amidoamine) dendrimers (PAMAM) individually immobilized on mica and confirmed the interconnection of the PAMAM through coordination polymers by atomic force microscopy. PMID:16207059

Tokuhisa, Hideo; Kanesato, Masatoshi

2005-10-11

274

Ruthenium and osmium complexes of hemilabile chiral monophosphinite ligands derived from 1D-pinitol or 1D-chiro-inositol as catalysts for asymmetric hydrogenation reactions.  

Science.gov (United States)

The monophosphinite ligands, 1D-1,2;5,6-di-O-cyclopentylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P1), 1D-1,2;5,6-di-O-isopropylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P2), 1D-1,2;5,6-di-O-cyclohexylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P3), and 1D-1,2;5,6-di-O-cyclopentylidene-3-O-ethyl-4-O-diphenylphosphino-chiro-inositol (D-P4), can be conveniently prepared from the chiral natural products 1D-pinitol or 1D-chiro-inositol. On treatment of toluene solutions of RuCl2(PPh3)3 with two mole equivalents of the ligands D-PY (Y = 1-4) the complexes RuCl2(D-P1)2 (1), RuCl2(D-P2)2 (4), RuCl2(D-P3)2 (5), or RuCl2(D-P4)2 (6), respectively, are formed. Similarly, treatment of OsCl2(PPh3)3 with D-P1 gives OsCl2(D-P1)2 (7). The single crystal X-ray structure determination of 1 reveals that each D-P1 ligand coordinates to ruthenium through phosphorus and the oxygen atom of the methoxyl group. Treatment of 1 with excess LiBr or LiI results in metathesis of the chloride ligands and RuBr2(D-P1)2 (2) or RuI2(D-P1)2 (3), respectively, are formed. Exposure of a solution of 1 to carbon monoxide results in the very rapid formation of RuCl2(CO)2(D-P1)2 (8), thereby demonstrating the ease with which the oxygen donors are displaced from the metal and hence the hemilabile nature of the two bidentate D-P1 ligands in 1. Preliminary studies indicate that 1-7 act as catalysts for the asymmetric hydrogenation reactions of acetophenone and 3-quinuclidinone to give the corresponding alcohols in generally high conversions but low enantiomeric excesses. PMID:25315464

Slade, Angela T; Lensink, Cornelis; Falshaw, Andrew; Clark, George R; Wright, L James

2014-12-01

275

Molecular, Physicochemical and Rheological Characteristics of Introgressive Triticale/Triticum monococcum ssp. monococcum Lines with Wheat 1D/1A Chromosome Substitution  

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

276

Molecular, physicochemical and rheological characteristics of introgressive Triticale/Triticum monococcum ssp. monococcum lines with wheat 1D/1A chromosome substitution.  

Science.gov (United States)

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

277

Ring-polymer molecular dynamics: Rate coefficient calculations for energetically symmetric (near thermoneutral) insertion reactions (X + H2) ? HX + H(X = C(1D), S(1D))  

Science.gov (United States)

Following our previous study of prototypical insertion reactions of energetically asymmetric type with the RPMD (Ring-Polymer Molecular Dynamics) method [Y. Li, Y. Suleimanov, and H. Guo, J. Phys. Chem. Lett. 5, 700 (2014)], we extend it to two other prototypical insertion reactions with much less exothermicity (near thermoneutral), namely, X + H2 ? HX + H where X = C(1D), S(1D), in order to assess the accuracy of this method for calculating thermal rate coefficients for this class of reactions. For both chemical reactions, RPMD displays remarkable accuracy and agreement with the previous quantum dynamic results that make it encouraging for the future application of the RPMD to other barrier-less, complex-forming reactions involving polyatomic reactants with any exothermicity.

Suleimanov, Yury V.; Kong, Wendi J.; Guo, Hua; Green, William H.

2014-12-01

278

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

International Nuclear Information System (INIS)

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 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

279

Regulation of c-fos expression by the dopamine D1-D2 receptor heteromer.  

Science.gov (United States)

The dopamine D1 and D2 receptors form the D1-D2 receptor heteromer in a subset of neurons and couple to the Gq protein to regulate intracellular calcium signaling. In the present study the effect of D1-D2 heteromer activation and disruption on neuronal activation in the rat brain was mapped. This was accomplished using the dopamine agonist SKF 83959 to activate the D1-D2 heteromer in combination with a TAT-D1 disrupting peptide we developed, and which has been shown to disrupt the D1/D2 receptor interaction and antagonize D1-D2 heteromer-induced cell signaling and behavior. Acute SKF 83959 administration to rats induced significant c-fos expression in the nucleus accumbens that was significantly inhibited by TAT-D1 pretreatment. No effects of SKF 83959 were seen in caudate putamen. D1-D2 heteromer disruption by TAT-D1 did not have any effects in any striatal subregions, but induced significant c-fos immunoreactivity in a number of cortical regions including the orbitofrontal cortex, prelimbic and infralimbic cortices and piriform cortex. The induction of c-fos by TAT-D1 was also evident in the anterior olfactory nucleus, as well as the lateral habenula and thalamic nuclei. These findings show for the first time that the D1-D2 heteromer can differentially regulate c-fos expression in a region-dependent manner either through its activation or through tonic inhibition of neuronal activity. PMID:25446350

Perreault, M L; Shen, M Y F; Fan, T; George, S R

2015-01-29

280

Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO  

Science.gov (United States)

Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k+l from Blanke and Delecluse, 1993, and two equation models: generic length scale closures from Umlauf and Burchard, 2003) are able to correctly reproduce the classical test of Kato and Phillips (1969) under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a 1-year period (mid-2010 to mid-2011) at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between -2 and 2 °C during the stratified period (June to October). However, the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D) is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA">http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA). This package is a good starting point for further investigation of vertical processes.

Reffray, G.; Bourdalle-Badie, R.; Calone, C.

2015-01-01

281

Role of human CD4 D1D2 domain in HIV-1 infection.  

Science.gov (United States)

Broadly neutralizing antibodies and appropriate immunogens are critical for preexposure prophylaxis and therapeutic HIV vaccines. In this study, we aimed to explore effective antibodies against the genetically diverse HIV-1 strains by investigating the roles of human CD4 D1D2 domain and nonvariable immugens. The human CD4 D1D2 domain and the chimeric protein of mouse D1 domain/human D2 domain were expressed in Sf9 insect cells and purified by gel-filtration chromatography. The human CD4 D1D2 domain potently inhibited the infection of 77.8% HIV-1 pseudoviruses, including the clades AE, B' and BC, with less than 20 ?g/mL of IC(50). pcDNA3.1-mhD1D2m and pcDNA3.1-mhD2m plasmids were used for the production of mouse anti-human CD4 polyclonal antibodies. The neutralizing activities of the polyclonal antibodies were determined by using pseudotyped HIV-1 viruses. The antibodies induced by plasmids containing human CD4 D1D2 domain were able to potently inhibit all pseudotyped HIV-1 strains. The antibodies from mhD1D2m-immunized mice also showed strong binding capacity to CD4 expressed on the surface of TZM-bl cells. The potent and broad inhibitory activity of antibodies against the human CD4 D1D2 domain may be used to develop effective passive immunization agent to control the spread of HIV infection. PMID:23252862

Li, Lan; Shi, Xuanling; Lu, Qingyu; Zhang, Senyan; Wang, Xinquan; Jiang, Xu; Liu, Yifeng; Wang, Guanshi; Zhu, Weijun; Lei, Rongyue; Wu, Hao

2013-01-01

282

Syntheses, crystal structures and luminescent properties of two new 1D d 1 coordination polymers constructed from 2,2'-bibenzimidazole and 1,4-benzenedicarboxylate  

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

283

Syntheses, crystal structures and luminescent properties of two new 1D d10 coordination polymers constructed from 2,2?-bibenzimidazole and 1,4-benzenedicarboxylate  

Science.gov (United States)

Two novel interesting d10 metal coordination polymers, [Zn(H 2bibzim)(BDC)] n ( 1) and [Cd(H 2bibzim)(BDC)] n ( 2) [H 2bibzim=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 d10 coordination polymeric framework.

Wen, Lili; Li, Yizhi; Dang, Dongbin; Tian, Zhengfang; Ni, Zhaoping; Meng, Qingjin

2005-11-01

284

1D Parameter Study on Tar Conversion in Counterflow Diffusion Flames  

Energy Technology Data Exchange (ETDEWEB)

Gasification is a renewable technology with a potential for providing biogas for use in heat and power generation. Tars in biogas from the gasification process still present a problem especially in end-use applications like gas turbines or internal combustion engines. These applications require that the gas is cooled; cooling however results in tar condensation which leads to fouling and clogging of the equipment. Gas cleaning and conditioning systems to control tar levels exist and are still being improved to make them efficient and affordable. With the right physical conditions, tar cracking can be a successful alternative to remove tars in biogas. This study investigated the oxidation of a fixed amount of tar species in a biogas composition using a computational fluid dynamics model of a 1D counterflow diffusion flame in which the air-fuel equivalence ratio is assumed to be 1. Simulations were performed using an in-house code Chem1D at atmospheric conditions, a fixed air temperature of 300 K and a strain rate of 10s{sup -1} which was later changed to 100s{sup -1}. Three tar species, benzene, naphthalene and phenanthrene were studied. The major focus was on the influence of radical production and temperature effects on tar removal as the fuel temperature, fuel hydrogen content, and the oxygen content in the oxidiser were altered. Results revealed that the dominant reactions responsible for the conversion of the tar species were H, O, and OH radical reactions. H radical reactions were the majority followed by OH reactions. High fuel inlet temperatures favour production of the three radicals with small increments in maximum flame temperature. Trends showed that the tar species' consumption rates increased and were sensitive to maximum temperature changes. Increasing the hydrogen content in the fuel showed a trend of decreasing consumption of the added tar species. This was unexpected because there was increased production of H radicals as well as a small increase in maximum temperatures. It was recommended that further investigation into the reaction kinetics involving the H radical is needed to find out what happens when the hydrogen content in the fuel is increased. This study revealed that increasing the oxygen content favours higher radical concentrations, in specific OH and O radicals. There are high flame temperatures increments and an increase in the relative total tar consumption rates. The study showed that temperature effects seem to be more influential in the consumption of the tar species compared to the effect of radical chemistry. The two mechanisms compared had similar trends. This was done for benzene as the added tar species. An investigation into the trends with naphthalene and phenanthrene species using the Richter2 mechanism was recommended to compare with the ABF mechanism (C2 chemistry of the Appel, Bockhorn, and Frenklach mechanism) trends obtained to check for consistency. Other mechanisms can also be investigated for similar trends. Finally, there is a need to translate the results of the study in a 2D computational fluid dynamics model for analysis in a more practical situation. This will help in designing an optimal tar cracking reactor.

Makumbi, S.E.

2008-08-15

285

VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm  

Science.gov (United States)

Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Paraná sedimentary basin (Bebedouro and Pirassununga cities), both located in São Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies.

Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Santos, Fernando Acácio Monteiro dos; Almeida, Emerson Rodrigo

2015-01-01

286

CD1d-restricted antigen presentation by V?9V?2-T cells requires trogocytosis.  

Science.gov (United States)

CD1d-restricted invariant natural killer T cells (iNKT) constitute an important immunoregulatory T-cell subset that can be activated by the synthetic glycolipid ?-galactosylceramide (?-GalCer) and play a dominant role in antitumor immunity. Clinical trials with ?-GalCer-pulsed monocyte-derived dendritic cells (moDC) have shown anecdotal antitumor activity in advanced cancer. It was reported that phosphoantigen (pAg)-activated V?9V?2-T cells can acquire characteristics of professional antigen-presenting cells (APC). Considering the clinical immunotherapeutic applications, V?9V?2-T APC can offer important advantages over moDC, potentially constituting an attractive novel APC platform. Here, we demonstrate that V?9V?2-T APC can present antigens to iNKT. However, this does not result from de novo synthesis of CD1d by V?9V?2-T, but critically depends on trogocytosis of CD1d-containing membrane fragments from pAg-expressing cells. CD1d-expressing V?9V?2-T cells were able to activate iNKT in a CD1d-restricted and ?-GalCer-dependent fashion. Although ?-GalCer-loaded moDC outperformed V?9V?2-T APC on a per cell basis, V?9V?2-T APC possess unique features with respect to clinical immunotherapeutic application that make them an interesting platform for consideration in future clinical trials. PMID:24934445

Schneiders, Famke L; Prodöhl, Jan; Ruben, Jurjen M; O'Toole, Tom; Scheper, Rik J; Bonneville, Marc; Scotet, Emmanuel; Verheul, Henk M W; de Gruijl, Tanja D; van der Vliet, Hans J

2014-08-01

287

TBC1D16 is a Rab4A GTPase activating protein that regulates receptor recycling and EGF receptor signaling  

OpenAIRE

Rab4A is a master regulator of receptor recycling from endocytic compartments to the plasma membrane. The protein TBC1D16 is up-regulated in melanoma, and TBC1D16-overexpressing melanoma cells are dependent on TBC1D16. We show here that TBC1D16 enhances the intrinsic rate of GTP hydrolysis by Rab4A. TBC1D16 is both cytosolic and membrane associated; the membrane-associated pool colocalizes with transferrin and EGF receptors (EGFRs) and early endosome antigen 1, but not with LAMP1 protein. Exp...

Goueli, Basem S.; Powell, Marianne Broome; Finger, Elizabeth C.; Pfeffer, Suzanne R.

2012-01-01

288

Universal nature of collective plasmonic excitations in finite 1-D carbon-based nanostructures  

CERN Document Server

Tomonaga-Luttinger (T-L) theory predicts collective plasmon resonances in 1-D nanostructure conductors of finite length, that vary roughly in inverse proportion to the length of the structure. Yet, such resonances have not been clearly identified in experiments so far. Here we provide evidence of the T-L plasmon resonances using first-principle computational real-time spectroscopy studies of representative finite 1-D carbon-based nanostructures ranging from atom and benzene-like chain structures to short carbon nanotubes. Our all-electron Time-Dependent Density-Functional Theory (TDDFT) real-time simulation framework is capable to accurately capture the relevant nanoscopic effects including correct frequencies for known optical transitions, and various collective plasmon excitations. The presence of 1-D T-L plasmons is universally predicted by the various numerical experiments, which also demonstrate a phenomenon of resonance splitting. Extending these simulations to longer structures will allow the accurate ...

Polizzi, Eric

2015-01-01

289

Spontaneous solitons in the thermal equilibrium of a quasi-1D Bose gas.  

Science.gov (United States)

We show that solitons occur generically in the thermal equilibrium state of a weakly interacting elongated Bose gas, without the need for external forcing or perturbations. This reveals a major new quality to the experimentally widespread quasicondensate state, usually thought of as primarily phase-fluctuating. Thermal solitons are seen in uniform 1D, trapped 1D, and elongated 3D gases, appearing as shallow solitons at low quasicondensate temperatures, becoming widespread and deep as temperature rises. This behavior can be understood via thermal occupation of the type II excitations in the Lieb-Liniger model of a uniform 1D gas. Furthermore, we find that the quasicondensate phase includes very appreciable density fluctuations while leaving phase fluctuations largely unaltered from the standard picture derived from a density-fluctuation-free treatment. PMID:23215499

Karpiuk, Tomasz; Deuar, Piotr; Bienias, Przemys?aw; Witkowska, Emilia; Paw?owski, Krzysztof; Gajda, Mariusz; Rz??ewski, Kazimierz; Brewczyk, Miros?aw

2012-11-16

290

[3H]-5-carboxamidotryptamine labels 5-HT1D binding sites in bovine substantia nigra.  

OpenAIRE

1. [3H]-5-hydroxytryptamine (5-HT) has been shown to radiolabel at least five types of 5-HT binding sites in mammalian brain tissue, 5-HT1A, 5-HT1C, 5-HT1D and 5-HT1D and 5-HT1E (Frazer et al., 1990). Selective masking of 5-HT1A and 5-HT1C receptors, has uncovered binding sites which display both high (5-HT1D) and low (5-HT1E) affinity for 5-carboxamidotryptamine (5-CT). By utilizing [3H]-5-CT we have eliminated a portion of the complex binding (5-HT1E) seen when [3H]-5-HT is used as a radiol...

Nowak, H. P.; Mahle, C. D.; Yocca, F. D.

1993-01-01

291

PC-1D installation manual and user's guide  

Energy Technology Data Exchange (ETDEWEB)

PC-1D is a software package for personal computers that uses finite-element analysis to solve the fully-coupled two-carrier semiconductor transport equations in one dimension. This program is particularly useful for analyzing the performance of optoelectronic devices such as solar cells, but can be applied to any bipolar device whose carrier flows are primarily one-dimensional. This User's Guide provides the information necessary to install PC-1D, define a problem for solution, solve the problem, and examine the results. Example problems are presented which illustrate these steps. The physical models and numerical methods utilized are presented in detail. This document supports version 3.1 of PC-1D, which incorporates faster numerical algorithms with better convergence properties than previous versions of the program. 51 refs., 17 figs., 5 tabs.

Basore, P.A.

1991-05-01

292

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

CERN Document Server

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

293

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

Science.gov (United States)

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

294

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.))

295

1-D Two-phase Flow Investigation for External Reactor Vessel Cooling  

Energy Technology Data Exchange (ETDEWEB)

During a severe accident, when a molten corium is relocated in a reactor vessel lower head, the RCF(Reactor Cavity Flooding) system for ERVC (External Reactor Vessel Cooling) is actuated and coolants are supplied into a reactor cavity to remove a decay heat from the molten corium. This severe accident mitigation strategy for maintaining a integrity of reactor vessel was adopted in the nuclear power plants of APR1400, AP600, and AP1000. Under the ERVC condition, the upward two-phase flow is driven by the amount of the decay heat from the molten corium. To achieve the ERVC strategy, the two-phase natural circulation in the annular gap between the external reactor vessel and the insulation should be formed sufficiently by designing the coolant inlet/outlet area and gap size adequately on the insulation device. Also the natural circulation flow restriction has to be minimized. In this reason, it is needed to review the fundamental structure of insulation. In the existing power plants, the insulation design is aimed at minimizing heat losses under a normal operation. Under the ERVC condition, however, the ability to form the two-phase natural circulation is uncertain. Namely, some important factors, such as the coolant inlet/outlet areas, flow restriction, and steam vent etc. in the flow channel, should be considered for ERVC design. T-HEMES 1D study is launched to estimate the natural circulation flow under the ERVC condition of APR1400. The experimental facility is one-dimensional and scaled down as the half height and 1/238 channel area of the APR1400 reactor vessel. The air injection method was used to simulate the boiling at the external reactor vessel and generate the natural circulation two-phase flow. From the experimental results, the natural circulation flow rate highly depended on inlet/outlet areas and the circulation flow rate increased as the outlet height as well as the supplied water head increased. On the other hand, the simple analysis using the drift flux model was carried out to predict the natural circulation flow rate and estimate the pressure drop distribution from the momentum equation. The calculated circulation flow rate was similar to experimental results within about 15% error bound. Also the effect of the turbine flow meter, which was installed to measure the circulation flow rate, was found that the natural circulation flow rate decreased due to the form loss of the turbine flow meter. And the simple analysis without the pressure drop of the turbine flow meter was performed to estimate the natural circulation phenomena under the actual ERVC condition.

Kim, Jae Cheol

2007-02-15

296

1-D Two-phase Flow Investigation for External Reactor Vessel Cooling  

International Nuclear Information System (INIS)

During a severe accident, when a molten corium is relocated in a reactor vessel lower head, the RCF(Reactor Cavity Flooding) system for ERVC (External Reactor Vessel Cooling) is actuated and coolants are supplied into a reactor cavity to remove a decay heat from the molten corium. This severe accident mitigation strategy for maintaining a integrity of reactor vessel was adopted in the nuclear power plants of APR1400, AP600, and AP1000. Under the ERVC condition, the upward two-phase flow is driven by the amount of the decay heat from the molten corium. To achieve the ERVC strategy, the two-phase natural circulation in the annular gap between the external reactor vessel and the insulation should be formed sufficiently by designing the coolant inlet/outlet area and gap size adequately on the insulation device. Also the natural circulation flow restriction has to be minimized. In this reason, it is needed to review the fundamental structure of insulation. In the existing power plants, the insulation design is aimed at minimizing heat losses under a normal operation. Under the ERVC condition, however, the ability to form the two-phase natural circulation is uncertain. Namely, some important factors, such as the coolant inlet/outlet areas, flow restriction, and steam vent etc. in the flow channel, should be considered for ERVC design. T-HEMES 1D study is launched to estimate the natural circulation flow under the ERVC condition of APR1400. The experimental facility is one-dPR1400. The experimental facility is one-dimensional and scaled down as the half height and 1/238 channel area of the APR1400 reactor vessel. The air injection method was used to simulate the boiling at the external reactor vessel and generate the natural circulation two-phase flow. From the experimental results, the natural circulation flow rate highly depended on inlet/outlet areas and the circulation flow rate increased as the outlet height as well as the supplied water head increased. On the other hand, the simple analysis using the drift flux model was carried out to predict the natural circulation flow rate and estimate the pressure drop distribution from the momentum equation. The calculated circulation flow rate was similar to experimental results within about 15% error bound. Also the effect of the turbine flow meter, which was installed to measure the circulation flow rate, was found that the natural circulation flow rate decreased due to the form loss of the turbine flow meter. And the simple analysis without the pressure drop of the turbine flow meter was performed to estimate the natural circulation phenomena under the actual ERVC condition

297

Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO  

Science.gov (United States)

Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k + l from Blanke and Delecluse, 1993 and two equation models: Generic Lengh Scale closures from Umlauf and Burchard, 2003) are able to correctly reproduce the classical test of Kato and Phillips (1969) under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a one-year period (mid-2010 to mid-2011) at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between -2 and 2 °C during the stratified period (June to October). However the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D) is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (PAPA">http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA). This package is a good starting point for further investigation of vertical processes.

Reffray, G.; Bourdalle-Badie, R.; Calone, C.

2014-08-01

298

Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO  

Directory of Open Access Journals (Sweden)

Full Text Available Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k + l from Blanke and Delecluse, 1993 and two equation models: Generic Lengh Scale closures from Umlauf and Burchard, 2003 are able to correctly reproduce the classical test of Kato and Phillips (1969 under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a one-year period (mid-2010 to mid-2011 at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between ?2 and 2 °C during the stratified period (June to October. However the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA. This package is a good starting point for further investigation of vertical processes.

G. Reffray

2014-08-01

299

Lipid binding orientation within CD1d affects recognition of Borrelia burgorferi antigens by NKT cells  

OpenAIRE

Invariant natural killer T cells (iNKT cells) respond to CD1d-presented glycolipids from Borrelia burgdorferi, the causative agent of Lyme disease. Although mouse and human iNKT cells respond to different antigens based on subtle differences in their fatty acids, the mechanism by which fatty acid structure determines antigenic potency is not well understood. Here we show that the mouse and human CD1d present glycolipids having different fatty acids, based in part upon a difference at a single...

Wang, Jing; Li, Yali; Kinjo, Yuki; Mac, Thien-thi; Gibson, Darren; Painter, Gavin F.; Kronenberg, Mitchell; Zajonc, Dirk M.

2010-01-01

300

Quantization of the fermionic sector in N=1, D=11 supergravity  

International Nuclear Information System (INIS)

It is shown that the fermionic sector of N=1, D=11 supergravity can be rearranged in such a way that a minimal number of auxiliary fields are necessary to be introduced so that the quartic gravitino interaction terms can be eliminated. After functional integration over the gravitino a effective action in terms of these auxiliary fields and the bosonic fields of N=1, D=11 supergravity is obtained. The non-vanishing expectation value of these auxiliary fields can lead to mass-like terms for the gravitino and contributions so the cosmological constant. (Author)

301

Calreticulin Controls the Rate of Assembly of CD1d Molecules in the Endoplasmic Reticulum*  

OpenAIRE

CD1d is an MHC class I-like molecule comprised of a transmembrane glycoprotein (heavy chain) associated with ?2-microglobulin (?2m) that presents lipid antigens to NKT cells. Initial folding of the heavy chain involves its glycan-dependent association with calreticulin (CRT), calnexin (CNX), and the thiol oxidoreductase ERp57, and is followed by assembly with ?2m to form the heterodimer. Here we show that in CRT-deficient cells CD1d heavy chains convert to ?2m-associated dimers at an acce...

Zhu, Yajuan; Zhang, Wei; Veerapen, Natacha; Besra, Gurdyal; Cresswell, Peter

2010-01-01

302

Dopamine D1-D2 receptor heteromer signaling pathway in the brain: emerging physiological relevance  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Dopamine is an important catecholamine neurotransmitter modulating many physiological functions, and is linked to psychopathology of many diseases such as schizophrenia and drug addiction. Dopamine D1 and D2 receptors are the most abundant dopaminergic receptors in the striatum, and although a clear segregation between the pathways expressing these two receptors has been reported in certain subregions, the presence of D1-D2 receptor heteromers within a unique subset of neurons, forming a novel signaling transducing functional entity has been shown. Recently, significant progress has been made in elucidating the signaling pathways activated by the D1-D2 receptor heteromer and their potential physiological relevance.

Hasbi Ahmed

2011-06-01

303

CRUNCH 1D: a computer program for seismic analysis of the HTGR core  

International Nuclear Information System (INIS)

This document serves as a user's manual and theoretical manual for the CRUNCH1D computer program. CRUNCH1D is a numerical integration code designed to analyze the HTGR core for seismic excitation. The core is represented as a one-dimensional horizontal strip of blocks constrained within the PCRV. Each block of the CRUNCH model represents one or more columns of the actual core. One additional block is provided to model the core support floor. Seismic excitation is provided by defining the motion of the PCRV. CRUNCH has two types of mathematical models for collisions; the standard spring-damper model, and an impulse-momentum model

304

The (2+1)-d U(1) Quantum Link Model Masquerading as Deconfined Criticality  

OpenAIRE

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 a dangerously irrelevant 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 de...

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

2013-01-01

305

Entangling strings of neutral atoms in 1D atomic pipeline structures  

CERN Document Server

We study a string of neutral atoms with nearest neighbor interaction in a 1D beam splitter configuration, where the longitudinal motion is controlled by a moving optical lattice potential. The dynamics of the atoms crossing the beam splitter maps to a 1D spin model with controllable time dependent parameters, which allows the creation of maximally entangled states of atoms by crossing a quantum phase transition. Furthermore, we show that this system realizes protected quantum memory, and we discuss the implementation of one- and two-qubit gates in this setup.

Dorner, U; Jaksch, D; Lewenstein, M; Zoller, P

2002-01-01

306

Entangling strings of neutral atoms in 1D atomic pipeline structures.  

Science.gov (United States)

We study a string of neutral atoms with nearest neighbor interaction in a 1D beam splitter configuration, where the longitudinal motion is controlled by a moving optical lattice potential. The dynamics of the atoms crossing the beam splitter maps to a 1D spin model with controllable time dependent parameters, which allows the creation of maximally entangled states of atoms by crossing a quantum phase transition. Furthermore, we show that this system realizes protected quantum memory, and we discuss the implementation of one- and two-qubit gates in this setup. PMID:12935017

Dorner, U; Fedichev, P; Jaksch, D; Lewenstein, M; Zoller, P

2003-08-15

307

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

OpenAIRE

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 experimen...

Kuo, Shou-yi; Lin, Hsin-i

2014-01-01

308

Single file diffusion enhancement in a fluctuating modulated quasi-1D channel  

Science.gov (United States)

We show that the diffusion of a single file of particles moving in a fluctuating modulated quasi-1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favoured by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by patterns of pinning sites.

Coupier, G.; Saint Jean, M.; Guthmann, C.

2007-03-01

309

Single File Diffusion enhancement in a fluctuating modulated 1D channel  

CERN Document Server

We show that the diffusion of a single file of particles moving in a fluctuating modulated 1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favored by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by adapted patterns of pinning sites.

Coupier, G; Guthmann, C; Coupier, Gwennou; Jean, Michel Saint; Guthmann, Claudine

2006-01-01

310

Using the D1D5 CFT to Understand Black Holes  

OpenAIRE

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 i...

Avery, Steven

2010-01-01

311

1D cadmium(II) thiocyanate systems: Synthesis and characterization of three new polymeric 1D cadmium(II) thiocyanato complexes  

Science.gov (United States)

Three new cadmium(II) thiocyanato complexes, [{Cd(NCS) 2(val)}·H 2O] n1, [Cd(NCS) 2(3-ampy) 2] n2, and [Cd(NCS) 2(pyrazolinone)] n3, (val = D, L-valine, 3-ampy = 3-aminopyridine and pyrazolinone = 3-methyl-1-phenyl-2-pyrazolin-5-one) have been synthesized and structurally characterized. The X-ray structure analysis revealed di-?-N,S thiocyanato bridges connecting cadmium centers in a 1D chain with the co-ligand blocking the remaining coordination sites. The structure of complex 1 features six coordinate Cd(II) centers, each cadmium is surrounded by two N atoms and two S atoms from two bridging N,S-thiocyanato groups giving rise to a zigzag 1D chain and two oxygen atoms of the alternating chelating ?-O,O'-valine that coordinates as zwitterionic terminal amino acid. The structure of complex 2 consists of octahedral Cd(II) centers, connected by di-?-N,S-bridging NCS groups, thus forming a 1D chain system along the [1 0 1] direction. The amino-groups are forming one intra-chain N sbnd H⋯N hydrogen bond and one interchain N sbnd H⋯N hydrogen bond to N-atoms of adjacent chains. The structure of 3 reveals di-?-N,S-NCS doubly bridged unusual penta-coordinated cadmium centers with the alternating monodentate pyrazolinone ligand blocking the fifth coordination site. IR spectra and thermal properties of complexes are reported.

Saber, Mohamed R.; Abu-Youssef, Morsy A. M.; Goher, Mohamed A. S.; Sabra, Berry A.; Hafez, Afaf K.; Badr, Ahmed M.-A.; Mautner, Franz A.

2012-01-01

312

Consumer generativity  

OpenAIRE

The concept of generativity--that is, adults' preoccupation for the well-being of the next generations--has been the subject of numerous studies in social psychology since the 1950's. In parallel, many companies are positioning their products and services as generative, a reality that has not been extensively studied from an academic perspective in marketing. To remedy this shortcoming, we propose the formal introduction of the concept of generativity in the marketing literature, as well as t...

Lacroix, Caroline

2011-01-01

313

Vapor generator  

International Nuclear Information System (INIS)

The object of the present invention is the provision of an improved vapor generator for use with a gas-cooled reactor in an electrical power generating facility. The vapor generator is particularly suited for use in a substantially cylindrical cavity in a pressure vessel and the length of tubing used in unheated sections and in expansion zones is minimized. (UK)

314

Ice Concentration Retrieval in Stratiform Mixed-phase Clouds Using Cloud Radar Reflectivity Measurements and 1D Ice Growth Model Simulations  

Energy Technology Data Exchange (ETDEWEB)

Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.

Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao

2014-10-01

315

Cytoplasmic retention of a nucleocytoplasmic protein TBC1D3 by microtubule network is required for enhanced EGFR signaling.  

Science.gov (United States)

The hominoid oncogene TBC1D3 enhances epidermal growth factor receptor (EGFR) signaling and induces cell transformation. However, little is known regarding its spatio-temporal regulation and mechanism of tumorigenesis. In the current study, we identified the microtubule subunit ?-tubulin as a potential interaction partner for TBC1D3 using affinity purification combined with mass spectrometry analysis. The interaction between TBC1D3 and ?-tubulin was confirmed by co-immunoprecipitation. Using the same method, we also revealed that TBC1D3 co-precipitated with endogenous ?-tubulin, another subunit of the microtubule. In agreement with these results, microtubule cosedimentation assays showed that TBC1D3 associated with the microtubule network. The ?-tubulin-interacting site of TBC1D3 was mapped to amino acids 286?353 near the C-terminus of the TBC domain. Deletion mutation within these amino acids was shown to abolish the interaction of TBC1D3 with ?-tubulin. Interestingly, the deletion mutation caused a complete loss of TBC1D3 from the cytoplasmic filamentous and punctate structures, and TBC1D3 instead appeared in the nucleus. Consistent with this, wild-type TBC1D3 exhibited the same nucleocytoplasmic distribution in cells treated with the microtubule depolymerizing agent nocodazole, suggesting that the microtubule network associates with and retains TBC1D3 in the cytoplasm. We further found that deficiency in ?-tubulin-interacting resulted in TBC1D3's inability to inhibit c-Cbl recruitment and EGFR ubiquitination, ultimately leading to dysregulation of EGFR degradation and signaling. Taken together, these studies indicate a novel model by which the microtubule network regulates EGFR stability and signaling through tubulin dimer/oligomer interaction with the nucleocytoplasmic protein TBC1D3. PMID:24714105

He, Ze; Tian, Tian; Guo, Dan; Wu, Huijuan; Chen, Yang; Zhang, Yongchen; Wan, Qing; Zhao, Huzi; Wang, Congyang; Shen, Hongjing; Zhao, Lei; Bu, Xiaodong; Wan, Meiling; Shen, Chuanlu

2014-01-01

316

1D Cahn-Hilliard equation: Ostwald ripening and application to modulated phase systems  

OpenAIRE

Using an approximate analytical solution of the Cahn-Hilliard equation describing the coalescence during a first order phase transition, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, we compute the thermodynamically stable period of a 1D modulated phase pattern.

Villain-guillot, Simon

2008-01-01

317

1D Cahn-Hilliard equation: Ostwald ripening and modulated phase systems  

OpenAIRE

Using an approximate analytical solution of the Cahn-Hilliard equation describing the coalescence during a first order phase transition, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, we compute the thermodynamically stable period of a 1D modulated phase pattern.

Villain-guillot, Simon

2007-01-01

318

Refining the classification of the irreps of the 1D N-Extended Supersymmetry  

OpenAIRE

The linear finite irreducible representations of the algebra of the 1D $N$-Extended Supersymmetric Quantum Mechanics are discussed in terms of their "connectivity" (a symbol encoding information on the graphs associated to the irreps). The classification of the irreducible representations with the same fields content and different connectivity is presented up to $N\\leq 8$.

Kuznetsova, Zhanna; Toppan, Francesco

2007-01-01

319

Arabidopsis UEV1D promotes Lysine-63-linked polyubiquitination and is involved in DNA damage response.  

Science.gov (United States)

DNA damage tolerance (DDT) in budding yeast requires Lys-63-linked polyubiquitination of the proliferating cell nuclear antigen. The ubiquitin-conjugating enzyme Ubc13 and the Ubc enzyme variant (Uev) methyl methanesulfonate2 (Mms2) are required for this process. Mms2 homologs have been found in all eukaryotic genomes examined; however, their roles in multicellular eukaryotes have not been elucidated. We report the isolation and characterization of four UEV1 genes from Arabidopsis thaliana. All four Uev1 proteins can form a stable complex with At Ubc13 or with Ubc13 from yeast or human and can promote Ubc13-mediated Lys-63 polyubiquitination. All four Uev1 proteins can replace yeast MMS2 DDT functions in vivo. Although these genes are ubiquitously expressed in most tissues, UEV1D appears to express at a much higher level in germinating seeds and in pollen. We obtained and characterized two uev1d null mutant T-DNA insertion lines. Compared with wild-type plants, seeds from uev1d null plants germinated poorly when treated with a DNA-damaging agent. Those that germinated grew slower, and the majority ceased growth within 2 weeks. Pollen from uev1d plants also displayed a moderate but significant decrease in germination in the presence of DNA damage. This report links Ubc13-Uev with functions in DNA damage response in Arabidopsis. PMID:18178771

Wen, Rui; Torres-Acosta, J Antonio; Pastushok, Landon; Lai, Xiaoqin; Pelzer, Lindsay; Wang, Hong; Xiao, Wei

2008-01-01

320

Strong coupling hadron masses in 1/d expansion for Wilson fermions  

CERN Document Server

Motivated by the weak-strong coupling expansion \\cite{Rosenstein}, we calculate the spectrum of hadrons using a systematic 1/d (d - dimensionality of spacetime) in addition to a strong coupling expansion in \\beta. The 1/d expansion is pushed to the next to leading order in (1/d) for mesons and next to next to leading order for baryons. We do the calculation using Wilson fermions with arbitrary r and show that doublers decouple from the spectrum only when r is close to the Wilson's value r=1. For these r the spectrum is much closer to the lattice results and the phenomenological values than those obtained by using either the (nonsystematic) "randomwalk" approximation or the hopping parameter expansion. In particular, the value of the nucleon to \\rho - meson mass ratio is lowered to \\frac {3 \\log d -1/4}{2 {\\rm arccosh} 2}+O(1/d)\\approx 1.48. The result holds even for \\beta as large as 5, where the weak-strong coupling expansion is applicable and therefore these results are expected to be reasonable.

Rosenstein, B

1995-01-01

321

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

CERN Document Server

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

322

3D Versus 1D Radiative Transfer Modeling of Planetary Nebulae  

Science.gov (United States)

Planetary nebulae are the products of the fast stellar wind from the end of the AGB star phase. To date, there are many one-dimensional radiative transfer codes, and a few fully 3D codes that can model the ionization of the planetary nebulae. Some limitations on 1D codes are that they can only make spherical or parallel plane models, while 3D codes take much computing power and memory to run. A pseudo-3D code such as pyCloudy can model a planetary nebula in 3D by making multiple runs of a 1D code such as Cloudy in different angles from the center of the nebula. We compared the 1D models with pseudo-3D models to determine if the 1D models give good approximations for the observed parameters of the planetary nebulae. We find that one-dimensional codes can actually give good estimates for electron temperature and density in a bipolar planetary nebula.

Pantoja, Blake M.; Ladjal, Djazia

2015-01-01

323

A fast sonochemical method to prepare 1D and 3D nanostructures of bismuth sulfide  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Nesse trabalho, um método sonoquímico de síntese de nanoestruturas de sulfeto de bismuto em 1D e 3D foi desenvolvido e comparado com uma rota sintética empregando aquecimento sob refluxo. O método sonoquímico monstrou ser mais rápido e eficiente na obtenção de nanoestruturas com alta homogeneidade m [...] orfológica. A forma e qualidade dos nanocristais foram dependentes do tipo de solvente empregado na síntese. Superestruturas em 3D semelhantes a flores foram obtidas quando etileno glicol puro foi utilizado como solvente, enquanto estruturas em 1D na forma de nanobastões foram obtidas quando utilizada uma mistura de dimetilsulfóxido e etileno como solvente. Abstract in english In this work, a sonochemical method to synthesize nanostructures of bismuth sulfide in 1D and 3D framework was developed and compared with a synthetic route with heating under reflux. The sonochemical method showed to be faster and more efficient than refluxing method to obtain nanostructures with h [...] igh morphological homogeneity. Form and quality of the nanocrystals were dependent on the type of solvent employed in the synthesis procedure. 3D flower-like superstructures were obtained when ethylene glycol was used as solvent, while 1D nanorods were obtained when a mixture of dimethyl sulfoxide and ethylene glycol was used as solvent.

Paulo R. R., Mesquita; Jorge S., Almeida; Leonardo S. G., Teixeira; Antônio F. da, Silva; Luciana A., Silva.

2013-02-01

324

Behavioral Responses in Animal Model of Congenital Muscular Dystrophy 1D.  

Science.gov (United States)

Congenital muscular dystrophies 1D (CMD1D) present a mutation on the LARGE gene and are characterized by an abnormal glycosylation of ?-dystroglycan (?-DG), strongly implicated as having a causative role in the development of central nervous system abnormalities such as cognitive impairment seen in patients. However, in the animal model of CMD1D, the brain involvement remains unclear. Therefore, the objective of this study is to evaluate the cognitive involvement in the Large(myd) mice. To this aim, we used adult homozygous, heterozygous, and wild-type mice. The mice underwent six behavioral tasks: habituation to an open field, step-down inhibitory avoidance, continuous multiple trials step-down inhibitory avoidance task, object recognition, elevated plus-maze, and forced swimming test. It was observed that Large(myd) individuals presented deficits on the habituation to the open field, step down inhibitory avoidance, continuous multiple-trials step-down inhibitory avoidance, object recognition, and forced swimming. This study shows the first evidence that abnormal glycosylation of ?-DG may be affecting memory storage and restoring process in an animal model of CMD1D. PMID:25465243

Comim, Clarissa M; Schactae, Aryadnne L; Soares, Jaime A; Ventura, Letícia; Freiberger, Viviane; Mina, Francielle; Dominguini, Diogo; Vainzof, Mariz; Quevedo, João

2014-12-01

325

Silencing of TBC1D15 promotes RhoA activation and membrane blebbing.  

Science.gov (United States)

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

326

Models of Late-Type Disk Galaxies: 1-D Versus 2-D  

CERN Document Server

We investigate the effects of stochasticity on the observed galaxy parameters by comparing our stochastic star formation two-dimensional (2-D) galaxy evolution models with the commonly used one-dimensional (1-D) models with smooth star formation. The 2-D stochastic models predict high variability of the star formation rate and the surface photometric parameters across the galactic disks and in time.

Mineikis, Tadas

2015-01-01

327

Systematics of the single-particle properties of the 1d2s shell nuclei  

International Nuclear Information System (INIS)

Experimental data on pickup and stripping reactions have been used to investigate single-particle properties of the most stable nuclei of the 1d2s shell. Populations of proton subshells and single-particle energies of the nuclear hamiltonian are obtained. (orig.)

328

Dilepton production in high energy heavy ion collisions with 3+1D relativistic viscous hydrodynamics  

International Nuclear Information System (INIS)

We present a first calculation of the dilepton yield and elliptic flow done with 3+1D viscous hydrodynamical simulations of relativistic heavy ion collisions at the top RHIC energy. A comparison with recent experimental data from the STAR collaboration is made

329

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

330

On the self-assembly of TiOx into 1D NP network nanostructures  

Science.gov (United States)

Here, we report for the first time a ‘ligand free’ method of designing 1D TiOx supramolecular network materials, which starts from Ti bare metal powder. Each TiOx oxidation step has been carefully investigated with different analytical techniques, including high resolution transmission electron microscopy/high resolution scanning electron microscopy (HRTEM/HRSEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy and superconducting quantum interference device (SQUID) measurements. The self-assembly of TiOx nanoparticles (NPs) into 1D supramolecular nanoparticle networks is induced by the formation of mixed valent TiII,III species. The synthesis starts with etching a bare Ti surface, followed by a continuous oxidation of TiOx clusters and NPs, and it finally ends with the self-assembly into rigid 1D NPs chains. Today, such self-assembled 1D NP TiOx network materials are bridging the gap between the nanoscale and the macroscopic material world and will further provide interesting research opportunities.

Redel, Engelbert; Sai Kiran Chakravadhanula, Venkata; Lan, Yanhua; Natzeck, Carsten; Heissler, Stefan

2015-02-01

331

Probing the dispersion properties of 1D nanophotonic waveguides with far-field Fourier optics  

DEFF Research Database (Denmark)

We present an advanced Fourier space imaging technique to probe guided light in nanophotonic structures with an effective numerical aperture of 2.5. This superresolution technique allows us to successfully investigate the dispersive properties of 1D nanowaveguides such as photonic crystal W1 waveguides, photonic wire, slot waveguides and couplers.

Le Thomas, N.; Jágerská, J.

2008-01-01

332

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.

333

On the self-assembly of TiOx into 1D NP network nanostructures.  

Science.gov (United States)

Here, we report for the first time a 'ligand free' method of designing 1D TiOx supramolecular network materials, which starts from Ti bare metal powder. Each TiOx oxidation step has been carefully investigated with different analytical techniques, including high resolution transmission electron microscopy/high resolution scanning electron microscopy (HRTEM/HRSEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy and superconducting quantum interference device (SQUID) measurements. The self-assembly of TiOx nanoparticles (NPs) into 1D supramolecular nanoparticle networks is induced by the formation of mixed valent Ti(II,III) species. The synthesis starts with etching a bare Ti surface, followed by a continuous oxidation of TiOx clusters and NPs, and it finally ends with the self-assembly into rigid 1D NPs chains. Today, such self-assembled 1D NP TiOx network materials are bridging the gap between the nanoscale and the macroscopic material world and will further provide interesting research opportunities. PMID:25591051

Redel, Engelbert; Chakravadhanula, Venkata Sai Kiran; Lan, Yanhua; Natzeck, Carsten; Heissler, Stefan

2015-02-01

334

On the 1D Modeling of Fluid Flowing through a Junction  

OpenAIRE

Consider a fluid flowing through a junction between two pipes with different sections. Its evolution is described by the 2D or 3D Euler equations, whose analytical theory is far from complete and whose numerical treatment may be rather costly. This note compares different 1D approaches to this phenomenon.

Colombo, Rinaldo M.; Garavello, Mauro

2009-01-01

335

1-D and 2D-NMR assignments of nigricin from Iris imbricata  

Directory of Open Access Journals (Sweden)

Full Text Available Ethanolic crude extract of I. imbricata Lindl. (Iridaceae was subjected to column chromatography on silica gel with varying portions of MeOH: CHCl3. Nigicin (irisolone was isolated and its identification carried out by IR, UV, MS, 1-D and 2-D NMR spectroscopy

Seyed Abdul Majid Ayatollahi

2005-01-01

336

Crystal Structures of Human TBC1D1 and TBC1D4 (AS160) RabGTPase-activating Protein (RabGAP) Domains Reveal Critical Elements for GLUT4 Translocation*  

OpenAIRE

We have solved the x-ray crystal structures of the RabGAP domains of human TBC1D1 and human TBC1D4 (AS160), at 2.2 and 3.5 Å resolution, respectively. Like the yeast Gyp1p RabGAP domain, whose structure was solved previously in complex with mouse Rab33B, the human TBC1D1 and TBC1D4 domains both have 16 ?-helices and no ?-sheet elements. We expected the yeast Gyp1p RabGAP/mouse Rab33B structure to predict the corresponding interfaces between cognate mammalian RabGAPs and Rabs, but found tha...

Park, Sang-youn; Jin, Wanzhu; Woo, Ju Rang; Shoelson, Steven E.

2011-01-01

337

Design and initial 1D radiography tests of the FANTOM mobile fast-neutron radiography and tomography system  

Science.gov (United States)

The FANTOM system is a tabletop sized fast-neutron radiography and tomography system newly developed at the Applied Nuclear Physics Division of Uppsala University. The main purpose of the system is to provide time-averaged steam-and-water distribution measurement capability inside the metallic structures of two-phase test loops for light water reactor thermal-hydraulic studies using a portable fusion neutron generator. The FANTOM system provides a set of 1D neutron transmission data, which may be inserted into tomographic reconstruction algorithms to achieve a 2D mapping of the steam-and-water distribution. In this paper, the selected design of FANTOM is described and motivated. The detector concept is based on plastic scintillator elements, separated for spatial resolution. Analysis of pulse heights on an event-to-event basis is used for energy discrimination. Although the concept allows for close stacking of a large number of detector elements, this demonstrator is equipped with only three elements in the detector and one additional element for monitoring the yield from the neutron generator. The first measured projections on test objects of known configurations are presented. These were collected using a Sodern Genie 16 neutron generator with an isotropic yield of about 1E8 neutrons per second, and allowed for characterization of the instrument's capabilities. At an energy threshold of 10 MeV, the detector offered a count rate of about 500 cps per detector element. The performance in terms of spatial resolution was validated by fitting a Gaussian Line Spread Function to the experimental data, a procedure that revealed a spatial unsharpness in good agreement with the predicted FWHM of 0.5 mm.

Andersson, P.; Valldor-Blücher, J.; Andersson Sundén, E.; Sjöstrand, H.; Jacobsson-Svärd, S.

2014-08-01

338

Determination of the absolute configuration of (+)-neopentyl-1-d alcohol by neutron and x-ray diffraction analysis.  

OpenAIRE

The absolute configuration of (+)-neopentyl-1-d alcohol, prepared by the reduction of 2,2-dimethylpropanal-1-d by actively fermenting yeast, has been determined to be S by neutron diffraction. The neutron study was carried out on the phthalate half ester of neopentyl-1-d alcohol, crystallized as its strychnine salt. The absolute configuration of the (-)-strychninium cation was first determined by an x-ray anomalous dispersion study of its iodide salt. The chiral skeleton of strychnine then se...

Yuan, H. S.; Stevens, R. C.; Bau, R.; Mosher, H. S.; Koetzle, T. F.

1994-01-01

339

Generative Semantics  

OpenAIRE

Generative semantics is (or perhaps was) a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of the program are a matter of some controversy and have been extensively debated. Generative semanticists took Chomsky's concept of deep structure

Karim Bagha

2011-01-01

340

Sound generator  

OpenAIRE

A sound generator, particularly a loudspeaker, configured to emit sound, comprising a rigid element (2) enclosing a plurality of air compartments (3), wherein the rigid element (2) has a back side (B) comprising apertures (4), and a front side (F) that is closed, wherein the generator is provided with at least one actuator (6), for instance one or more electromagnetic actuators and/or piezoelectric elements, configured to actuate the rigid element (2) for the generation of the sound.

Berkhoff, Arthur Perry

2008-01-01

341

Power generation  

International Nuclear Information System (INIS)

Whether world-wide or in Europe, gas consumption is driven by power generation. This workshop aims at reviewing various types of generation (combined heat and power, combined cycle, micro-turbines.) technologies, and their economic and environmental impact against other energy generation techniques. What might be the target date for combined cycle power plants within the French mix-energy? This article gathers 5 presentations about this topic given at the gas conference

342

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

OpenAIRE

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

343

Complementary regulation of TBC1D1 and AS160 by growth factors, insulin and AMPK activators  

OpenAIRE

Abstract AS160 and TBC1D1 are related RabGAPs implicated in regulating the trafficking of GLUT4 storage vesicles to the cell surface. All animal species examined contain TBC1D1, whereas AS160 evolved with the vertebrates. TBC1D1 has two clusters of phosphorylated residues, either side of the second PTB domain. Each cluster contains a 14-3-3-binding site. When AMPK is activated in HEK293 cells, 14-3-3s bind primarily to phosphoSer237 in TBC1D1; whereas 14-3-3 binding depends primari...

Chen, Shuai; Murphy, Jane; Toth, Rachel; Campbell, David G.; Morrice, Nick A.; Mackintosh, Carol

2007-01-01

344

Regulation of inflorescence branch development in rice through a novel pathway involving the pentatricopeptide repeat protein sped1-D.  

Science.gov (United States)

Panicle type has a direct bearing on rice yield. Here, we characterized a rice clustered-spikelet mutant, sped1-D, with shortened pedicels and/or secondary branches, which exhibits decreased pollen fertility. We cloned sped1-D and found that it encodes a pentatricopeptide repeat protein. We investigated the global expression profiles of wild-type, 9311, and sped1-D plants using Illumina RNA sequencing. The expression of several GID1L2 family members was downregulated in the sped1-D mutant, suggesting that the gibberellin (GA) pathway is involved in the elongation of pedicels and/or secondary branches. When we overexpressed one GID1L2, AK070299, in sped1-D plants, the panicle phenotype was restored to varying degrees. In addition, we analyzed the expression of genes that function in floral meristems and found that RFL and WOX3 were severely downregulated in sped1-D. These results suggest that sped1-D may prompt the shortening of pedicels and secondary branches by blocking the action of GID1L2, RFL, and Wox3. Moreover, overexpression of sped1-D in Arabidopsis resulted in the shortening of pedicels and clusters of siliques, which indicates that the function of sped1-D is highly conserved in monocotyledonous and dicotyledonous plants. Sequence data from this article have been deposited with the miRBase Data Libraries under accession no. MI0003201. PMID:24950892

Jiang, Guanghuai; Xiang, Yanghai; Zhao, Jiying; Yin, Dedong; Zhao, Xianfeng; Zhu, Lihuang; Zhai, Wenxue

2014-08-01

345

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

Science.gov (United States)

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 Escherichia coli yielded sufficient amounts of only one mutant (P133R). This enzyme exhibited reduced K(m) and k(cat) values 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. PMID:21185810

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

2011-05-30

346

Radioisotope generator  

International Nuclear Information System (INIS)

A radioisotope generator is described in which it is possible to interupt the elution process at any desired time, i.e. before the electron flacon is full. The interuption is performed in such a way that sterile air is simultaneously admitted into the generator, into both the column and the elution flacon. (Th.P.)

347

Radionuclide Generators  

Science.gov (United States)

Radionuclide generator systems continue to play a key role in providing both diagnostic and therapeutic radionuclides for various applications in nuclear medicine, oncology, and interventional cardiology. Although many parent/daughter pairs have been evaluated as radionuclide generator systems, there are a relatively small number of generators, which are currently in routine clinical and research use. Essentially every conceivable approach has been used for parent/separation strategies, including sublimation, thermochromatographic separation, solvent extraction, and adsorptive column chromatography. The most widely used radionuclide generator for clinical applications is the 99Mo/99mTc generator system, but recent years have seen an enormous increase in the use of generators to provide therapeutic radionuclides, which has paralleled the development of complementary technologies for targeting agents for therapy and in the general increased interest in the use of unsealed therapeutic radioactive sources. More recently, use of the 68Ge/68Ga generator is showing great potential as a source of positron-emitting 68Ga for positron emission tomography (PET)/CT imaging. Key advantages for the use of radionuclide generators include reasonable costs, the convenience of obtaining the desired daughter radionuclide on demand, and availability of the daughter radionuclide in high specific activity, no-carrier added form.

Rösch, F.; Knapp, F. F. (Russ)

348

Verification and comparison of four numerical schemes for a 1D viscoelastic blood flow model.  

Science.gov (United States)

A reliable and fast numerical scheme is crucial for the 1D simulation of blood flow in compliant vessels. In this paper, a 1D blood flow model is incorporated with a Kelvin-Voigt viscoelastic arterial wall. This leads to a nonlinear hyperbolic-parabolic system, which is then solved with four numerical schemes, namely: MacCormack, Taylor-Galerkin, monotonic upwind scheme for conservation law and local discontinuous Galerkin. The numerical schemes are tested on a single vessel, a simple bifurcation and a network with 55 arteries. The numerical solutions are checked favorably against analytical, semi-analytical solutions or clinical observations. Among the numerical schemes, comparisons are made in four important aspects: accuracy, ability to capture shock-like phenomena, computational speed and implementation complexity. The suitable conditions for the application of each scheme are discussed. PMID:25145651

Wang, Xiaofei; Fullana, Jose-Maria; Lagrée, Pierre-Yves

2014-08-22

349

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

CERN Document Server

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

350

Slice imaging of nitric acid photodissociation: The O(1D) + HONO channel  

International Nuclear Information System (INIS)

We report an imaging study of nitric acid (HNO3) photodissociation near 204 nm with detection of O(1D), one of the major decomposition products in this region. The images show structure reflecting the vibrational distribution of the HONO coproduct and significant angular anisotropy that varies with recoil speed. The images also show substantial alignment of the O(1D) orbital, which is analyzed using an approximate treatment that reveals that the polarization is dominated by incoherent, high order contributions. The results offer additional insight into the dynamics of the dissociation of nitric acid through the S3 (2 1A') excited state, resolving an inconsistency in previously reported angular distributions, and pointing the way to future studies of the angular momentum polarization.

351

Beyond 1D: spectral line formation with 3D hydrodynamical model atmospheres of red giants  

CERN Document Server

We present the results of realistic, 3D, hydrodynamical, simulations of surface convection in red giant stars with varying effective temperatures and metallicities. We use the convection simulations as time-dependent, hydrodynamical, model atmospheres to compute spectral line profiles for a number of ions and molecules under the assumption of local thermodynamic equilibrium (LTE). We compare the results with the predictions of line formation calculations based on 1D, hydrostatic, model stellar atmospheres in order to estimate the impact of 3D models on the derivation of elemental abundances. We find large negative 3D-1D LTE abundance corrections (typically -0.5 to -1 dex) for weak low-excitation lines from molecules and neutral species in the very low metallicity cases. Finally, we discuss the extent of departures from LTE in the case of neutral iron spectral line formation.

Collet, R; Trampedach, R

2007-01-01

352

Elastic and viscoplastic pellets fragmentation modeling using an axisymmetrical 1D finite element code  

International Nuclear Information System (INIS)

During first rise to power in Power Water Reactor, fuel pellets crack because of thermal expansion. The phenomena of pellet cracking and fragments relocation have a major influence on rod behaviour and especially on the cladding behaviour in the case of pellet-cladding interaction. This article presents the modeling used to take into account the fragmented state of the pellet in the EDF fuel rod thermo-mechanical code, CYRANO3reg. The aim is to simulate more realistic stress and strain fields in the pellet. The investigated method consists in adding parameters in the 1D finite elements calculations in order to integrate the multi-dimensional fragmentation effects in the axisymmetrical 1D code CYRANO3reg. These parameters modify the material behaviour by describing the fuel as an anisotropic damaged material. The modeling accounts for the opening and closing of radial pellet cracks. It has been implemented in the code for elastic and viscoplastic fuel behaviours

353

Statins impair CD1d-mediated antigen presentation through the inhibition of prenylation.  

Science.gov (United States)

Statins are widely used as cholesterol-lowering agents that also decrease inflammation and target enzymes essential for prenylation, an important process in the activation and intracellular transport of proteins vital for a wide variety of cellular functions. Here, we report that statins impair a critical component of the innate immune response, CD1d-mediated Ag presentation. The addition of specific intermediates in the isoprenylation pathway reversed this effect, whereas specific targeting of enzymes responsible for prenylation mimicked the inhibitory effects of statins on Ag presentation by CD1d as well as MHC class II molecules. This study demonstrates the importance of isoprenylation in the regulation of Ag presentation and suggests a mechanism by which statins reduce inflammatory responses. PMID:19342651

Khan, Masood A; Gallo, Richard M; Renukaradhya, Gourapura J; Du, Wenjun; Gervay-Hague, Jacquelyn; Brutkiewicz, Randy R

2009-04-15

354

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

OpenAIRE

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...

Beer, M. S.; Stanton, J. A.; Bevan, Y.; Heald, A.; Reeve, A. J.; Street, L. J.; Matassa, V. G.; Hargreaves, R. J.; Middlemiss, D. N.

1993-01-01

355

Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image  

CERN Document Server

Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.

Shakhakarmi, Niraj

2012-01-01

356

Effect of the deformation operator in the D1D5 CFT  

CERN Document Server

The D1D5 CFT gives a holographic dual description of a near-extremal black hole in string theory. The interaction in this theory is given by a marginal deformation operator, which is composed of supercharges acting on a twist operator. The twist operator links together different copies of a free CFT. We study the effect of this deformation operator when it links together CFT copies with winding numbers M and N to produce a copy with winding M+N, populated with excitations of a particular form. We compute the effect of the deformation operator in the full supersymmetric theory, firstly on a Ramond-Ramond ground state and secondly on states with an initial bosonic or fermionic excitation. Our results generalize recent work which studied only the bosonic sector of the CFT. Our findings are a step towards understanding thermalization in the D1D5 CFT, which is related to black hole formation and evaporation in the bulk.

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

2014-01-01

357

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

358

A First Measurement of the Tensor-Polarized Structure Function b1d  

International Nuclear Information System (INIS)

The Hermes experiment studies the spin structure of the nucleon using the 27.6 GeV longitudinally polarized positron beam of HERA and an internal target of pure gases. In addition to the well-known spin structure function g1, measured precisely with longitudinally polarized proton and deuteron targets, the use of a tensor-polarized deuteron target provides access to the tensor polarized structure function b1d. The latter, measured with an unpolarized beam, quantifies the dependence of the parton momentum distribution on the nucleon spin. Hermes had a 1-month dedicated run with a tensor polarized deuterium target during the 2000 data taking period. Here preliminary results on the tensor-polarized structure function b1d are presented for the kinematic range 0.002 < x < 0.85 and 0.1 GeV2 < Q2 < 20 GeV2

359

A First Measurement of the Tensor-Polarized Structure Function b1d  

CERN Document Server

The Hermes experiment studies the spin structure of the nucleon using the 27.6 GeV longitudinally polarized positron beam of HERA and an internal target of pure gases. In addition to the well-known spin structure function g_1, measured precisely with longitudinally polarized proton and deuteron targets, the use of a tensor-polarized deuteron target provides access to the tensor polarized structure function b1d. The latter, measured with an unpolarized beam, quantifies the dependence of the parton momentum distribution on the nucleon spin. Hermes had a 1-month dedicated run with a tensor polarized deuterium target during the 2000 data taking period. Here preliminary results on the tensor-polarized structure function b1d are presented for the kinematic range 0.002

Contalbrigo, M

2002-01-01

360

Scanning Gate Microscopy of a 1D InAs/InP Nanowire Quantum Dot  

Science.gov (United States)

One-dimensional (1D) nanowire quantum dots provide ideal systems to probe the quantum behavior of electrons. We study long, thin quantum dots (length ˜300nm, diameter ˜20nm) in an InAs/InP nanowire heterostructure. They provide an interesting system - the Coulomb blockade allows one to control the electron number and measure the energy of quantum states. The nanowire diameter is less than the Bohr radius, making nanowire dots 1D for modest electron numbers. Using a liquid-He cooled scanning gate microscope (SGM) [1], we image the nanowire's conductance as a function of tip position. The conducting SGM tip creates a movable gate to probe the system. We present conductance images of long dots, which use Coulomb blockade to probe the potential profile of the nanowire system and the effects of the metal/semiconductor contacts. [4pt] [1] A. Bleszynski-Jayich et. al , Phys. Rev. B 77, 245327 (2008).

Boyd, Erin E.; Trodahl, Halvar J.; Westervelt, R. M.; Nilsson, Kristian; Samuelson, Lars

2010-03-01

361

Rotating condensed-boson gases in a 1D lattice at finite temperature  

Science.gov (United States)

In this paper, we study the thermodynamic properties of a rotating boson gases in a one-dimensional (1D) optical lattice at finite temperature. Our system is formed by loading three-dimensional boson-clouds into 1D optical lattice and subjected to rotate with angular velocity ? about the z-axis (rotating condensate in a quasi-two-dimensional trap). We employ the semiclassical approximation to calculate the condensate fraction, critical temperature and the heat capacity of the system. The calculated results show that the rotating condensates in a quasi-two-dimensional have interesting properties which are absent in both three or pure two-dimensional systems. Our results can be extended to investigate the current experiments of rotating Bose-Einstein condensation produced or transferred in one-dimensional optical lattices.

Hassan, Ahmed S.; Soliman, Shemi S. M.

2015-02-01

362

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.

363

A contribution to the 1D modelling of fuel element mechanics  

International Nuclear Information System (INIS)

A fuel element mechanics model must involve such effects as fuel cracking, the friction contact of the fuel and the cladding and so on. These effects are however essentially 3D ones and far from being trivial. This paper makes an attempt to model the fuel element mechanical behavior in the simplest way as a system of 1D problems depending only on one space variable. The presented general theories deal with a boundary (contact) value problem for one fuel rod section, a homogenized fuzzy-crack problem and a 1D axial friction contact problem. An interconnection of particular submodels is discussed. Numerical examples illustrating the particular submodels and the model as a whole are presented. (orig.)

364

Lifshitz theories with extra dimensions and 3+1-d Lorentz invariance  

CERN Document Server

We construct Lifshitz scalar field theories in 4+1 dimensions which retain 3+1-d Lorentz invariance and therefore ensure a unique limiting speed in the 3+1-d world. Such a construction is potentially useful in developing field-theoretic ultraviolet completions of extra-dimensional field theories. The extra dimension y is treated asymmetrically from the usual three spatial dimensions by introducing derivatives of order 2n with respect to y in the action. We show that lambda phi^4 theory becomes progressively less non-renormalisable by power counting as n is increased. This suggests that the non-local theory obtained in the infinite-n limit may be complete in the ultraviolet.

He, Xiao-Gang; Volkas, Raymond R

2011-01-01

365

Na-ion dynamics in Quasi-1D compound NaV2O4  

Science.gov (United States)

We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV2O4. By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above Tdiff ? 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above Tdiff. Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV2O4 and related compounds in energy related applications.

Månsson, M.; Umegaki, I.; Nozaki, H.; Higuchi, Y.; Kawasaki, I.; Watanabe, I.; Sakurai, H.; Sugiyama, J.

2014-12-01

366

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

367

2D/1D approximations to the 3D neutron transport equation. II: Numerical comparisons  

International Nuclear Information System (INIS)

In a companion paper [1], (i) several new '2D/1D equations' are introduced as accurate approximations to the 3D Boltzmann transport equation, (ii) the simplest of these approximate equations is systematically discretized, and (iii) a theoretically stable iteration scheme is developed to solve the discrete equations. In this paper, numerical results are presented that confirm the theoretical predictions made in [1]. (authors)

368

Dopamine D1-D2 receptor heteromer signaling pathway in the brain: emerging physiological relevance  

OpenAIRE

Abstract Dopamine is an important catecholamine neurotransmitter modulating many physiological functions, and is linked to psychopathology of many diseases such as schizophrenia and drug addiction. Dopamine D1 and D2 receptors are the most abundant dopaminergic receptors in the striatum, and although a clear segregation between the pathways expressing these two receptors has been reported in certain subregions, the presence of D1-D2 receptor heteromers within a unique subset of neur...

Hasbi Ahmed; O'Dowd Brian F; George Susan R

2011-01-01

369

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

CERN Document Server

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

370

EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP  

International Nuclear Information System (INIS)

In the mid 80's, a four-group/two-region, entirely analytical 1D nodal benchmark appeared. It was readily acknowledged that this special case was as far as one could go in terms of group number and still achieve an analytical solution. In this work, we show that by decomposing the solution to the multigroup diffusion equation into homogeneous and particular solutions, extension to any number of groups is a relatively straightforward exercise using the mathematics of linear algebra

371

1-D numerical modelling of shallow flows with variable horizontal density  

OpenAIRE

A 1-D numerical model is presented for vertically homogeneous shallow flows with variable horizontal density. The governing equations represent depth-averaged mass and momentum conservation of a liquid-species mixture, and mass conservation of the species in the horizontal direction. Here, the term 'species' refers to material transported with the liquid flow. For example, when the species is taken to be suspended sediment, the model provides an idealized simulation of hyper-concentrated sedi...

Leighton, Fz; Borthwick, Agl; Taylor, Ph

2010-01-01

372

FROM 1D TO 3D FERRIMAGNETS IN THE EDTA FAMILY  

OpenAIRE

The results of increasing the dimensionality of a 1-d ferrimagnet to 2 and 3-d are discussed with reference to a novel 3-dimensional ordered phase based on the EDTA ligand (MtM (M'EDTA)2 .4H2O). Low temperature magnetic susceptibility data for (MtMM') = (ZnNiNi), (CoNiNi) and (CoCoCo) are discussed on the basis of the magnetic sublattices involved.

Coronado, E.; Sapin A, F.; Go?mez-romero, P.; Beltra?n, D.; Burriel, R.; Carlin, R.

1988-01-01

373

Characterisation of J(O1D) at Cape Grim 2000-2005  

Science.gov (United States)

Estimates of the rate of production of excited oxygen atoms due to the photolysis of ozone J(O1D) have been derived from radiation measurements carried out at Cape Grim, Tasmania (40.6° S, 144.7° E). These estimates agree well with measurements made during SOAPEX-II and with model estimates of clear sky photolysis rates. Observations spanning 2000-2005 have been used to quantify the impact of season, cloud and ozone column amount. The annual cycle of J(O1D) has been investigated via monthly means. These means show an inter-annual variation (monthly standard deviation) of 9%, but in midsummer and midwinter this reduces to 3-4%. Factors dependent upon solar zenith angle and satellite derived total ozone column explain 87% of the observed signal variation of the individual measurements. The impact of total column ozone, expressed as a Radiation Amplification Factor (RAF), is found to be ~1.45, in agreement with model estimates. This ozone dependence explains 20% of the variation observed at medium solar zenith angles (30-50°). The impact of clouds results in a median reduction of 14% in J(O1D) for the same solar zenith angle range. At all solar zenith angles less than 50° approximately 10% of measurements show enhanced J(O1D) due to cloud scattering and this fraction climbs to 25% at higher solar angles. Including estimates of cloudiness derived from Long Wave Radiation measurements resulted in a statistically significant fit to observations but the quality of the fit did not increase significantly as measured by the reduced R2.

Wilson, S. R.

2014-07-01

374

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

OpenAIRE

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...

Dougan, Stephanie K.; Salas, Azucena; Rava, Paul; Agyemang, Amma; Kaser, Arthur; Morrison, Jamin; Khurana, Archana; Kronenberg, Mitchell; Johnson, Caroline; Exley, Mark; Hussain, M. Mahmood; Blumberg, Richard S.

2005-01-01

375

Preparation of 1D C/C Composites with High Thermal Conductivity  

OpenAIRE

Three kinds of pitches were used as matrix precursors, the self-fabricated mesophase (AR) pitch-based carbon fibers were used as the reinforcing agent, one dimension (1D) carbon/carbon (C/C) composites were prepared by a hot-pressing molding method at about 500° and subsequent carbonization as well as graphitization treatments. The influence of precursor pitches and heat-treatment temperatures (HTTs) on the thermal conductive properties of the C/C composites were investigated. The morphology...

Lin Jian-feng, Yuan Guan-ming

2013-01-01

376

A Fulling-Kuchment theorem for the 1D harmonic oscillator  

CERN Document Server

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

377

Transport coefficients of D1-D5-P system and the membrane paradigm  

CERN Document Server

I discuss a correspondence between string theory and the black hole membrane paradigm in the context of D1-D5-P system. By using the Kubo formula, I calculate transport coefficients of the effective string model induced by two kinds of minimal scalars. Then, I show that these transport coefficients exactly agree with the corresponding membrane transport coefficients of a five dimensional near extremal black hole with three charges.

Sasai, Yuya

2012-01-01

378

Scotogenic $Z_2$ or $U(1)_D$ Model of Neutrino Mass with $\\Delta(27)$ Symmetry  

CERN Document Server

The scotogenic model of radiative neutrino mass with $Z_2$ or $U(1)_D$ dark matter is shown to accommodate $\\Delta(27)$ symmetry naturally. The resulting neutrino mass matrix is identical to either of two forms, one proposed in 2006, the other in 2008. These two structures are studied in the context of present neutrino data, with predictions of $CP$ violation and neutrinoless double beta decay.

Ma, Ernest

2014-01-01

379

Scotogenic Z2 or U(1)D model of neutrino mass with ?(27) symmetry  

Science.gov (United States)

The scotogenic model of radiative neutrino mass with Z2 or U(1)D dark matter is shown to accommodate ?(27) symmetry naturally. The resulting neutrino mass matrix is identical to either of two forms, one proposed in 2006, the other in 2008. These two structures are studied in the context of present neutrino data, with predictions of CP violation and neutrinoless double beta decay.

Ma, Ernest; Natale, Alexander

2014-06-01

380

Comment on ``Integrability and Coherence of Hopping between 1D Correlated Electron Systems''  

OpenAIRE

We comment on recent numerical studies concerning coupled 1D electron liquids (F. Mila and D. Poilblanc, Phys. Rev. Lett. 76, 287 (1996)). In particular, we point out that the importance of integrability observed in the results of these authors for the quantity $P(t)$ is really an indication of the importance of integrability for questions of ergodicity, rather than questions of coherence. We discuss why this is so, and why the quantity $$ is a more appropria...

Clarke, David; Strong, Steven

1996-01-01

381

Discontinuous Galerkin finite element method applied to the 1-D spherical neutron transport equation  

International Nuclear Information System (INIS)

Discontinuous Galerkin finite element methods are used to estimate solutions to the non-scattering 1-D spherical neutron transport equation. Various trial and test spaces are compared in the context of a few sample problems whose exact solution is known. Certain trial spaces avoid unphysical behaviors that seem to plague other methods. Comparisons with diamond differencing and simple corner-balancing are presented to highlight these improvements

382

Statins Impair CD1d-Mediated Antigen Presentation Through Inhibition of Prenylation1  

OpenAIRE

Statins are widely used as cholesterol-lowering agents that also decrease inflammation, and target enzymes essential for prenylation, an important process in the activation and intracellular transport of proteins vital for a wide variety of cellular functions. Here, we report that statins impair a critical component of the innate immune response, CD1d-mediated antigen presentation. The addition of specific intermediates in the isoprenylation pathway reversed this effect, whereas specific targ...

Khan, Masood A.; Gallo, Richard M.; Renukaradhya, Gourapura J.; Du, Wenjun; Gervay-hague, Jacquelyn; Brutkiewicz, Randy R.

2009-01-01

383

Mixed (1D-2D) quantum electron transport in percolating gold film  

OpenAIRE

The gold film (mean thickness $\\approx$ 3.5 nm) was condensed in high vacuum at temperature 70 K on single-crystal sapphire substrate. The transport properties of the film at low temperature reveal simultaneously indications of 1D and 2D quantum interference effects of weak localization and electron-electron interaction. It is shown that this behavior is determined by inhomogeneous electron transport at the threshold of thickness-controlled metal-insulator transition.

Beliayev, E. Yu; Belevtsev, B. I.; Kolesnichenko, Yu A.

2011-01-01

384

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)

385

Quantum phases of hard-core dipolar bosons in coupled 1D optical lattices  

OpenAIRE

Hard-core dipolar bosons trapped in a parallel stack of N>=2 1D optical lattices (tubes) can develop several phases made of composites of particles from different tubes: superfluids, supercounterfluids and insulators as well as mixtures of those. Bosonization analysis shows that these phases are threshold-less with respect to the dipolar interaction, with the key "control knob" being filling factors in each tube, provided the inter-tube tunneling is suppressed. The effective...

Safavi-naini, A.; Capogrosso-sansone, B.; Kuklov, A.

2014-01-01

386

Study of the 1D anisotropic Kondo necklace model at criticality via an entanglement entropy estimator  

OpenAIRE

We use an estimator of quantum criticality based on the entanglement entropy to discuss the ground state properties of the 1D anisotropic Kondo necklace model. We found that the T=0 phase diagram of the model is described by a critical line separating an antiferromagnetic phase from a Kondo singlet state. Moreover we calculate the conformal anomaly on the critical line and obtained that c tends to 0.5 as the thermodynamic limit is reached. We conclude that these transitions ...

Saguia, A.

2013-01-01

387

TROUGH - 1 D. A one-dimensional computer code for calculation of radionuclide transport in groundwater  

International Nuclear Information System (INIS)

A family of computer codes with the generic name TROUGH (Transport of Radioactive Outflows in Underground Hydrology) has been produced for the safety analysis of radioactive waste repositories. The simplest version of this family, TROUGH-1D, has undergone thorough development and testing and has been applied to several aspects of the NAGRA work. This present report contains a technical description and user manual for the code. (author)

388

Scaling Exponent for Coarsening in a 1D q-state system  

CERN Document Server

An exponent $\\beta$ which characterises non-equilibrium coarsening processes is calculated in a deterministic solvable model of coarsening for a 1D q-state Potts system. We study how the fraction of sites P which have never changed their state, scale with the characteristic domain length $$. $\\beta$ is defined by P \\sim $^{\\beta -1}$. We propose a new model of coarsening that prevents correlations from developing between domains thereby ensuring tractability and an exact result for any q.

Gopinathan, A

1998-01-01

389

1D Cahn-Hilliard dynamics: Ostwald ripening and application to modulated phase systems  

International Nuclear Information System (INIS)

We use a family of stationary solution of the Cahn-Hilliard dynamics in order to describe the coalescence during a first order phase transition. With this analytical ansatz, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, the same ansatz is also used to compute the thermodynamically stable period of a 1D modulated phase pattern, described by a Cahn-Hilliard dynamics with long range interaction terms

390

Ground-state spin structure of strongly interacting disordered 1D Hubbard model  

International Nuclear Information System (INIS)

We study the influence of on-site disorder on the magnetic properties of the ground state of the infinite-U one-dimensional (1D) Hubbard model. We find that the ground state is not ferromagnetic. This is analysed in terms of the algebraic structure of the spin dependence of the Hamiltonian. A simple explanation is derived for the 1/N periodicity in the persistent current for this model. (author)

391

MNM1D: A Numerical Code for Colloid Transport in Porous Media: Implementation and Validation  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Understanding the mechanisms that control the transport and fate of colloidal particles in subsurface environments is a crucial issue faced by several researchers in the last years. In many cases, natural colloids have been shown to play a major role in the spreading of strongly sorbing contaminants, while manufactured micro-and nanoparticles, which are nowadays widely spread in the subsurface, can be toxic themselves. On the other hand, in recent years studies have been addressed to the use of highly reactive micro-and nanoparticle suspensions for the remediation of contaminated aquifers. Provide the set of partial-differential model equations and its numerical solution for the colloid transport under transient hydrochemical conditions, that have been previously shown to be extremely important in micro-and nanoparticle transport in porous media. Approach: This study presented a novel colloid transport model, called MNM1D (Micro-and Nanoparticle transport Model in porous media in 1D geometry, able to simulate the colloid behavior in porous media in the presence of both constant and transient hydrochemical parameters (namely ionic strength. The model accounts for attachment and detachment phenomena, that can be modeled with one or two linear and/or langmuirian interaction sites. The governing equations were solved using a finite-differences approach, herein presented and discussed in details. Results: Both qualitative and quantitative comparisons with results of well-established colloid transport models, based both on analytical and numerical solutions of the colloid transport equation, were performed. The MNM1D results were found to be in good agreement with these solutions. Conclusion: The shown good agreement between MNM1D and the other models indicated that this code can represent in the future a useful tool for the simulation of colloidal transport in groundwater under transient hydrochemical conditions.

Tiziana Tosco

2009-01-01

392

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

393

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

394

CO(2) selective 1D double chain dipyridyl-porphyrin based porous coordination polymers.  

Science.gov (United States)

Thermal reactions of MnCl(DPyP) (DPyP = 5,15-di(4-pyridyl)-10,20-diphenylporphyrin) as a metalloligand with Co(II) and Zn(II) ions in dimethylformamide led to neutral one-dimensional (1D) double chain dipyridyl-porphyrin-based porous coordination polymers (PCPs), Co3(DPyP)3·4DMF (I) and Zn3(DPyP)3·2DMF·4H2O (II). Both PCPs were structurally characterized by X-ray crystallography. Particularly, the central Mn(III) ion in MnCl(DPyP) was transmetallated with Co(II) or Zn(II) ions and the central Co(II) or Zn(II) ions were further coordinated to pyridyl groups of neighboring M(DPyP) (M = Co or Zn) porphyrin complexes. PCPs I and II are isostructural and each 1D double chain interacts with another 1D double chain by multiple hydrogen bonding to stabilize the resulting framework. Therefore, solvent-free 1D double chain PCPs have permanent porosity, and the void volumes of the solvent-free I and II are calculated to be 22.6% and 23.0%, respectively. Gas sorption analysis indicated that I and II exhibited selective adsorption of CO2 at 196 K. Both PCPs exhibited much smaller sorption abilities for N2 (77 K), H2 (77 K), and CH4 (196 K) than CO2 (196 K). Both PCPs exhibited different PXRD patterns when dried at 373 K, which indicated that the framework transformation of the isostructural M3(DPyP)3 type of PCPs strongly depended on the type of central metal ions. PMID:24496095

Kim, Hyun-Chul; Lee, Young Sun; Huh, Seong; Lee, Suk Joong; Kim, Youngmee

2014-04-21

395

TBC1D14 regulates autophagosome formation via Rab11- and ULK1-positive recycling endosomes.  

OpenAIRE

Autophagy is a bulk degradation process characterized by the formation of double membrane vesicles called autophagosomes. The exact molecular mechanism of autophagosome formation and the origin of the autophagosomal membrane remain unclear. We screened 38 human Tre-2/Bub2/Cdc16 domain-containing Rab guanosine triphosphatase-activating proteins (GAPs) and identified 11 negative regulators of starvation-induced autophagy. One of these putative RabGAPs, TBC1D14, colocalizes and interacts with th...

Longatti, A.; Lamb, Ca; Razi, M.; Yoshimura, S.; Barr, FA; Tooze, Sa

2012-01-01

396

The immunoregulatory role of CD1d-restricted natural killer T cells in disease.  

OpenAIRE

Natural killer T (NKT) cells constitute a T cell subpopulation that shares several characteristics with NK cells. NKT cells are characterized by a narrow T cell antigen receptor (TCR) repertoire, recognize glycolipid antigen in the context of the monomorphic CD1d antigen-presenting molecule, and have the unique capacity to rapidly produce large amounts of both T helper (Th) 1 and Th2 cytokines. Important roles of NKT cells have now been demonstrated in the regulation of autoimmune, allergic, ...

Vliet, Hj; Molling, J. W.; Blomberg-van Flier, B. M. E. Von; Nishi, N.; Kolgen, W.; Eertwegh, A. J. M. Den; Pinedo, H. M.; Giaccone, G.; Scheper, R. J.

2004-01-01

397

Quantum Integrable 1D anyonic Models: Construction through Braided Yang-Baxter Equation  

Directory of Open Access Journals (Sweden)

Full Text Available Applying braided Yang-Baxter equation quantum integrable and Bethe ansatz solvable 1D anyonic lattice and field models are constructed. Along with known models we discover novel lattice anyonic and q-anyonic models as well as nonlinear Schrödinger equation (NLS and the derivative NLS quantum field models involving anyonic operators, N-particle sectors of which yield the well known anyon gases, interacting through ? and derivative ?-function potentials.

Anjan Kundu

2010-10-01

398

Resistivity structure of Sumatran Fault (Aceh segment) derived from 1-D magnetotelluric modeling  

Science.gov (United States)

Sumatran Fault Zone is the most active fault in Indonesia as a result of strike-slip component of Indo-Australian oblique convergence. With the length of 1900 km, Sumatran fault was divided into 20 segments starting from the southernmost Sumatra Island having small slip rate and increasing to the north end of Sumatra Island. There are several geophysical methods to analyze fault structure depending on physical parameter used in these methods, such as seismology, geodesy and electromagnetic. Magnetotelluric method which is one of geophysical methods has been widely used in mapping and sounding resistivity distribution because it does not only has the ability for detecting contras resistivity but also has a penetration range up to hundreds of kilometers. Magnetotelluric survey was carried out in Aceh region with the 12 total sites crossing Sumatran Fault on Aceh and Seulimeum segments. Two components of electric and magnetic fields were recorded during 10 hours in average with the frequency range from 320 Hz to 0,01 Hz. Analysis of the pseudosection of phase and apparent resistivity exhibit vertical low phase flanked on the west and east by high phase describing the existence of resistivity contras in this region. Having rotated the data to N45°E direction, interpretation of the result has been performed using three different methods of 1D MT modeling i.e. Bostick inversion, 1D MT inversion of TM data, and 1D MT inversion of the impedance determinant. By comparison, we concluded that the use of TM data only and the impedance determinant in 1D inversion yield the more reliable resistivity structure of the fault compare to other methods. Based on this result, it has been shown clearly that Sumatra Fault is characterized by vertical contras resistivity indicating the existence of Aceh and Seulimeum faults which has a good agreement with the geological data.

Nurhasan, Sutarno, D.; Bachtiar, H.; Sugiyanto, D.; Ogawa, Y.; Kimata, F.; Fitriani, D.

2012-06-01

399

Modélisation 1D du comportement d'un clarificateur à partir du logiciel GPS-X  

OpenAIRE

The increase in number of regulations applying to treated water makes the design of Waste Water Treatment Plants (WWTP), and especially of the secondary clarifiers, every day more challenging. Waste water treatment modeling is a precious tool toward this optimized design. The here-described study aims at determining the values of the Takács 1D-model settling parameters which best fit the behavior of the four studied clarifiers'. This modeling is made via the GPS-X software. Firstly, we...

Deltimple, C.

2010-01-01

400

Obstacles Detection on a Road by Dense Stereovision with 1D Correlation Windows and Fuzzy Filtering  

OpenAIRE

In this paper, we propose an original approach to obstacles detection based on stereovision with mono-dimensional correlation windows. The result of the algorithm is a dense disparity map associated with a confidence map. For each pixel, correlation indices are computed for several widths of windows and several positions of the window centre. Three criteria, extracted from each correlation curve, are combined by a fuzzy filter to define a confidence measure. Our 1D method is compared to a cla...

Lefebvre, Se?bastien; Ambellouis, Se?bastien; Cabestaing, Franc?ois

2006-01-01

401

Fermi 1D quantum gas Luttinger liquid approach and spin-charge separation  

CERN Document Server

We discuss the properties of quasi-1D quantum gases of fermionic atoms using the Luttinger liquid theory, including the presence of an optical lattice and of a longitudinal trapping potential. We analyze in particular the nature and manifestations of spin-charge separation, where in the case of atoms ``spin'' and ``charge'' refers to two internal atomic states and the atomic mass density, respectively.

Recati, A; Zwerger, W; Zoller, P

2003-01-01

402

Ripple - a spherical-harmonic postprocessor for 1-D LASNEX simulations  

International Nuclear Information System (INIS)

The first-order hydrodynamics code RIPPLE provides a lower-cost alternative to 2-D LASNEX for problems involving small deviations from spherical symmetry. RIPPLE, developed as a postprocessor for 1-D LASNEX, solves the linearized hydrodynamic equations using the LASNEX results as zero-order solutions. Linearity is not a severe limitation, since a target designer is frequently only interested in estimating the severity of instabilities and in determining the spatial wavelengths that exhibit greatest instability

403

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

OpenAIRE

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

404

On a 2D zoom for 1D shallow-water model: coupling and data assimilation  

OpenAIRE

In the context of river hydraulics we elaborate the idea of a 'zoom' model locally superposed on an open-channel network global model. The zoom model (2D shallow water equations) describes additional physical phenomena, which are not represented by the global model (1D shallow water equations with storage areas). Both models are coupled using the optimal control approach when the zoom model is used to assimilate local observations into the global model (variational data assimilation) by playi...

Monnier, Jerome; Gejadze, Igor

2007-01-01

405

Strong Laws of Large Numbers for &#x1D539;-Valued Random Fields  

OpenAIRE

We extend to random fields case, the results of Woyczynski, who proved Brunk's type strong law of large numbers (SLLNs) for &#x1D539;-valued random vectors under geometric assumptions. Also, we give probabilistic requirements for above-mentioned SLLN, related to results obtained by Acosta as well as necessary and sufficient probabilistic conditions for the geometry of Banach space associated to the strong and weak law of large numbers for multidimensionally indexed random vectors.

Lagodowski, Zbigniew A.

2009-01-01

406

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

OpenAIRE

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...

Jícha M.; Pokorný J.; Fišer J.

2012-01-01

407

On the Second Mixed Moment of the Characteristic Polynomials of 1D Band Matrices  

Science.gov (United States)

We consider the asymptotic behavior of the second mixed moment of the characteristic polynomials of 1D Gaussian band matrices, i.e., of the Hermitian N × N matrices H N with independent Gaussian entries such that = ? ik ? jl J ij , where . Assuming that , , we show that the moment's asymptotic behavior (as ) in the bulk of the spectrum coincides with that for the Gaussian Unitary Ensemble.

Shcherbina, Tatyana

2014-05-01

408

Time resolved nonlinear spectroscopy at the band edge of 1D photonic crystals  

OpenAIRE

Large refractive index changes have been measured at the band edge frequency of 1D photonic crystals. Results concerning both thin and thick samples of high and low refractive index contrast respectively are presented. The very large value of the refractive index changes obtained at moderate pump powers thanks to the strong enhancement of the local intensity inside the photonic crystal open the way to very small volume devices for optical signal processing. However, time-resolved experiments ...

Astic, Magali; Delaye, Philippe; Frey, Robert; Roosen, Ge?rald; Andre?, Re?gis; Belabas, N.; Sagnes, Isabelle; Raj, R.

2008-01-01

409

Random phase approximation for the 1D anti-ferromagnetic Heisenberg model  

International Nuclear Information System (INIS)

The Hartree-Fock random phase approximation (HF-RPA) approach is applied to the one-dimensional (1D) anti-ferromagnetic Heisenberg model in the Jordan-Wigner representation. Somewhat contrary to expectation, this leads to reasonable results for spectral functions and sum rules in the symmetry-unbroken phase. In a preliminary application of self-consistent RPA to finite-size chains, strongly improved results are obtained

410

A facile route for 3D aerogels from nanostructured 1D and 2D materials  

OpenAIRE

Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the tra...

Sung Mi Jung; Hyun Young Jung; Dresselhaus, Mildred S.; Yung Joon Jung; Jing Kong

2012-01-01

411

Inherent Two-Way Ambiguity in 2D Projective Reconstruction from Three Uncalibrated 1D Images  

OpenAIRE

It is shown that there always exists a two-way ambiguity for 2D projective reconstruction from three uncalibrated 1D views independent of the number of point correspondences. It is also shown that the two distinct projective reconstructions are exactly related by a quadratic transformation with the three camera centers as the fundamental points. The unique reconstruction exists only for the case where the three camera centers are aligned. The theoretical results are demonstrated on numerical ...

Quan, Long

1999-01-01

412

Two-Way Ambiguity in 2D Projective Reconstruction from Three Uncalibrated 1D Images  

OpenAIRE

We show that there is in genral a two-way ambiguity for 2D projective reconstruction from three uncalilbrated 1D views, independent of the number of point correspondences. The two distinct projective reconstructions are exactly related by a quadratic transformation with the three camera centers as fundamental points. Unique 2D reconstruction is possible only when the three camera centers are aligned. By Carlsson duality, there is a dual two-way ambiguity for 2D projective reconstruction from ...

Quan, Long

2001-01-01

413

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

414

Non-Abelian String and Particle Braiding in Topological Order - Modular SL(3,Z) Representation and 3+1D Twisted Gauge Theory  

CERN Document Server

String and particle excitations are examined in a class of 3+1D topological order described by a discrete gauge theory with a gauge group $G$ and a 4-cocycle twist $\\omega_4 \\in \\mathcal{H}^4(G,\\mathbb{R}/\\mathbb{Z})$ of $G$'s cohomology group. We demonstrate the topological spin and the spin-statistics relation for the closed strings, and their multi-string braiding. The 3+1D twisted gauge theory can be characterized by a representation of SL$(3,\\mathbb{Z})$ modular transformation, which we find its generators $\\mathsf{S}^{xyz}$ and $\\mathsf{T}^{xy}$ in terms of the gauge group $G$ and the 4-cocycle $\\omega_4$. As we compactify one of the 3D's direction $z$ into a compact circle inserted with a gauge flux $b$, we can use the generators of SL$(2,\\mathbb{Z})$ subgroup of SL$(3,\\mathbb{Z})$, $\\mathsf{S}^{xy}$ and $\\mathsf{T}^{xy}$, to study the dimension reduction of the 3D topological order $\\mathcal{C}^{3\\text{D}}$ to a direct sum of degenerate states of 2D topological orders $\\mathcal{C}_b^{2\\text{D}}$ in di...

Wang, Juven

2014-01-01

415

Numerical Modeling of Imploding Plasma liners Using the 1D Radiation-Hydrodynamics Code HELIOS  

Science.gov (United States)

The Plasma Liner Experiment (PLX) is attempting to form imploding plasma liners to reach 0.1 Mbar upon stagnation, via 30--60 spherically convergent plasma jets. PLX is partly motivated by the desire to develop a standoff driver for magneto-inertial fusion. The liner density, atomic makeup, and implosion velocity will help determine the maximum pressure that can be achieved. This work focuses on exploring the effects of atomic physics and radiation on the 1D liner implosion and stagnation dynamics. For this reason, we are using Prism Computational Science's 1D Lagrangian rad-hydro code HELIOS, which has both equation of state (EOS) table-lookup and detailed configuration accounting (DCA) atomic physics modeling. By comparing a series of PLX-relevant cases proceeding from ideal gas, to EOS tables, to DCA treatments, we aim to identify how and when atomic physics effects are important for determining the peak achievable stagnation pressures. In addition, we present verification test results as well as brief comparisons to results obtained with RAVEN (1D radiation-MHD) and SPHC (smoothed particle hydrodynamics).

Davis, J. S.; Hanna, D. S.; Awe, T. J.; Hsu, S. C.; Stanic, M.; Cassibry, J. T.; Macfarlane, J. J.

2010-11-01

416

Implementation and assessment of three-field modeling for MARS 1-D code  

International Nuclear Information System (INIS)

The two-phase mixture of liquid water and steam has been analyzed using the two-fluid (or two-phase) representation in MARS 1-D module, as is done in most reactor system analysis codes. MARS 1-D code could also treat noncondensable gas as a part of the gas phase, assuming thermal and mechanical equilibrium with the steam. Soluble materials such as boron are included in the liquid phase. The two-phase modeling of the liquid/gas mixture flows, even though quite adequate in most flow conditions, wouldn't quite closely represent the flow where entrained liquid is involved, especially in the channel flow. The entrained liquid, in so-called annular mist flow, is known to have much higher velocity than the continuous liquid along the channel wall has. It is therefore believed more appropriate to treat the entrained liquid in a separate manner from the continuous liquid in such a flow. In this study, the three-field modeling of the two-phase mixture is developed. The finite difference equations for the three-field equations thereafter are devised. The solution scheme has been implemented into the MARS 1-D code. To test the three-field implementation, several conceptual problems have been simulated using the new solution scheme

417

Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons  

International Nuclear Information System (INIS)

One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO2 ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose solution under N2 flow at different temperatures. The phase transformation process of hydrogen titanate ribbons was investigated by in-situ X-ray diffraction at various temperatures. Besides, one-dimensional carbon-modified TiO2 ribbons calcined at different temperatures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption isotherms, diffuse reflectance ultraviolet–visible spectroscopy, and so on. Carbon-modified TiO2 ribbons showed one-dimensional ribbon crystal structure and various crystal phases of TiO2. After being modified with carbon, a layer of uniform carbon film was coated on the surface of TiO2 ribbons, which improved their adsorption capacity for methyl orange as a model organic pollutant. One-dimensional carbon-modified TiO2 ribbons also exhibited enhanced visible-light absorbance with the increase of calcination temperatures. - Highlights: • The synthesis of 1D carbon-modified TiO2 ribbons. • The phase transformation of 1D carbon-modified TiO2 ribbons. • 1D carbon-modified TiO2 exhibites enhanced visible-light absorbance

418

Tuning the 1D-self-assembly of dicyano-functionalized helicene building-blocks  

International Nuclear Information System (INIS)

Full text: Effective control of chirality in supramolecular systems is an important challenge towards the assembly of well-defined nano-architectures from the bottom-up. The chirality transfer from single molecules onto 3D- and 2D-crystals is well known, however chirality in case of the 1D-objects (wires) is largely unexplored. Here we present a study based on Scanning Tunnelling Microscopy (STM) and X-Ray Photoelectron Spectroscopy (XPS) measurements and Density Functional Theory (DFT) calculations to understand the formation of 1D conglomerates from enantiopure dicyano functionalized heptahelicene molecules of both chiralities at different, well defined single-crystal surfaces. We show that the main bonding motif can be switched by temperature, substrate or adatom stimuli. We discuss the key driving forces for the formation of well-ordered long-range arrays and the chirality transfer on the single molecule scale as well as onto the 1D conglomerate as a whole. In comparison of experiment and theory, we deepen the insight into the chirality transfer in competition between molecule-molecule and surface-molecule interactions. (author)

419

Self-Assembly of Functional Molecules into 1D Crystalline Nanostructures.  

Science.gov (United States)

Self-assembled functional nanoarchitectures are employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials usage efficiency, low energy consumption, and high-performance devices. One-dimensional (1D) crystalline nanostructures, especially molecule-composed crystalline nanostructures, attract significant attention due to their fascinating infusion structure and functionality which enables the easy tailoring of organic molecules with excellent carrier mobility and crystal stability. In this review, we discuss the recent progress of 1D crystalline self-assembled nanostructures of functional molecules, which include both a small molecule-derived and a polymer-based crystalline nanostructure. The basic principles of the molecular structure design and the process engineering of 1D crystalline nanostructures are also discussed. The molecular building blocks, self-assembly structures, and their applications in optical, electrical, and photoelectrical devices are overviewed and we give a brief outlook on crucial issues that need to be addressed in future research endeavors. PMID:25523368

Guo, Yanbing; Xu, Liang; Liu, Huibiao; Li, Yongjun; Che, Chi-Ming; Li, Yuliang

2015-02-01

420

1-D kinetic divertor gas-box simulations and development of a 2-D code  

International Nuclear Information System (INIS)

We report on 1-D kinetic simulations of a gas-box divertor using the W1 collisional PIC code to compare with previous slot-divertor calculations. Two gas-box models are used: one with a uniform gas density and another where the gas is allowed to be attenuated by the plasma. We discuss initial comparisons of the kinetic W1 results with 1-D fluid theory to assess changes needed in SOL transport codes. We also present progress on the extension of W1 to two spatial dimensions. The simplest model couples adjacent magnetic field lines by an anomalous cross-field diffusion operator, but the potential is determined by 1-D ambipolar flow. We compare this model with a 2-D potential equation obtained by solving the current continuity equation, ? circ J = 0. Here the cross-field current can be described by conductivity from ion-neutral collisions, anomalous toroidal momentum transport, or polarization current. Such calculations require a high level of parallel computations to be practical, and we will report on experience with the T3D computer in this regard

421

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

422

Transient dynamic and modeling parameter sensitivity analysis of 1D solid oxide fuel cell model  

International Nuclear Information System (INIS)

Highlights: • A multiphysics, 1D, dynamic SOFC model is developed. • The presented model is validated experimentally in eight different operating conditions. • Electrochemical and thermal dynamic transient time expressions are given in explicit forms. • Parameter sensitivity is discussed for different semi-empirical parameters in the model. - Abstract: In this paper, a multiphysics solid oxide fuel cell (SOFC) dynamic model is developed by using a one dimensional (1D) modeling approach. The dynamic effects of double layer capacitance on the electrochemical domain and the dynamic effect of thermal capacity on thermal domain are thoroughly considered. The 1D approach allows the model to predict the non-uniform distributions of current density, gas pressure and temperature in SOFC during its operation. The developed model has been experimentally validated, under different conditions of temperature and gas pressure. Based on the proposed model, the explicit time constant expressions for different dynamic phenomena in SOFC have been given and discussed in detail. A parameters sensitivity study has also been performed and discussed by using statistical Multi Parameter Sensitivity Analysis (MPSA) method, in order to investigate the impact of parameters on the modeling accuracy

423

Modelling activities of experimental facilities related to advanced reactors. Considerations on 1D/3D issues  

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)

424

Implementation and validation of a 1D fluid model for collapsible channels.  

Science.gov (United States)

A 1D fluid model is implemented for the purpose of fluid-structure interaction (FSI) simulations in complex and completely collapsible geometries, particularly targeting the case of obstructive sleep apnea (OSA). The fluid mechanics are solved separately from any solid mechanics, making possible the use of a highly complex and/or black-box solver for the solid mechanics. The fluid model is temporally discretized with a second-order scheme and spatially discretized with an asymmetrical fourth-order scheme that is robust in highly uneven geometries. A completely collapsing and reopening geometry is handled smoothly using a modified area function. The numerical implementation is tested with two driven-geometry cases: (1) an inviscid analytical solution and (2) a completely closing geometry with viscous flow. Three-dimensional fluid simulations in static geometries are performed to examine the assumptions of the 1D model, and with a well-defined pressure-recovery constant the 1D model agrees well with 3D models. The model is very fast computationally, is robust, and is recommended for OSA simulations where the bulk flow pressure is primarily of interest. PMID:24008973

Anderson, Peter; Fels, Sidney; Green, Sheldon

2013-11-01

425

E-beam to complement optical lithography for 1D layouts  

Science.gov (United States)

The semiconductor industry is moving to highly regular designs, or 1D gridded layouts, to enable scaling to advanced nodes, as well as improve process latitude, chip size and chip energy consumption. The fabrication of highly regular ICs is straightforward. Poly and metal layers are arranged into 1D layouts. These 1D layouts facilitate a two-step patterning approach: a line-creation step, followed by a line-cutting step, to form the desired IC pattern (See Figure 1). The first step, line creation, can be accomplished with a variety of lithography techniques including 193nm immersion (193i) and Self-Aligned Double Patterning (SADP). It appears feasible to create unidirectional parallel lines to at least 11 nm half-pitch, with two applications of SADP for pitch division by four. Potentially, this step can also be accomplished with interference lithography or directed self assembly in the future. The second step, line cutting, requires an extremely high-resolution lithography technique. At advanced nodes, the only options appear to be the costly quadruple patterning with 193i, or EUV or E-Beam Lithography (EBL). This paper focuses on the requirements for a lithography system for "line cutting", using EBL to complement Optical. EBL is the most cost-effective option for line cutting at advanced nodes for HVM.

Lam, David K.; Liu, Enden D.; Smayling, Michael C.; Prescop, Ted

2011-04-01

426

Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons  

Energy Technology Data Exchange (ETDEWEB)

One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO{sub 2} ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose