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1

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

2

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 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)

3

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

4

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

5

Efficient computation of NACT seismograms  

Science.gov (United States)

We present a modification to the NACT formalism (Li and Romanowicz, 1995) for computing synthetic seismograms and sensitivity kernels in global seismology. In the NACT theory, the perturbed seismogram consists of an along-branch coupling term, which is computed under the well-known PAVA approximation (e.g. Woodhouse and Dziewonski, 1984), and an across-branch coupling term, which is computed under the linear Born approximation. In the classical formalism, the Born part is obtained by a double summation over all pairs of coupling modes, where the numerical cost grows as (number of sources * number of receivers) * (corner frequency)^4. Here, however, by adapting the approach of Capdeville (2005), we are able to separate the computation into two single summations, which are responsible for the “source to scatterer” and the “scatterer to receiver” contributions, respectively. As a result, the numerical cost of the new scheme grows as (number of sources + number of receivers) * (corner frequency)^2. Moreover, by expanding eigen functions on a wavelet basis, a compression factor of at least 3 (larger at lower frequency) is achieved, leading to a factor of ~10 saving in disk storage. Numerical experiments show that the synthetic seismograms computed from the new approach agree well with those from the classical mode coupling method. The new formalism is significantly more efficient when approaching higher frequencies and in cases of large numbers of sources and receivers, while the across-branch mode coupling feature is still preserved, though not explicitly.

Zheng, Z.; Romanowicz, B. A.

2009-12-01

6

3D Spectrum of Equatorial Density Irregularities Generated from Observed 1D Spectra  

Science.gov (United States)

ASTRA and Cornell University have a joint project underway to develop an inverse diffraction tomography algorithm suitable for a two-dimensional array of GPS receivers located in the equatorial region. A significant component of the research involves development of an accurate, realistic electro-magnetic propagation forward model that goes from the GPS satellites to the array of ground receivers. The forward model will be used to test the accuracy of the inverse diffraction tomography algorithm, help select the optimal method of doing the inversion, allow for comprehensive, sophisticated non-linear inversions, and help provide insight to the science that will result from the inversion analysis. The method of approach to the forward model includes a realistic 3D model of the electron density irregularities, arbitrary time-varying geometry between satellite and ground receiver array and multiple phase screens to allow for strong scattering. The focus of this talk is on the development of the 3D spectrum of the irregularities, and how the 3D spectrum can be generated from observed in-situ 1D spectra from rockets or satellites such C/NOFS. The C/NOFS satellite has an in-situ Plasma Langmuir Probe (PLP) sensor that is capable of measuring electron density fluctuations at sample rates of 512 Hz. Preliminary analysis has been performed on these fluctuations. Spectra have been calculated for a number of different altitudes and local times. Preliminary results are presented from this research and, assuming a power law form for the spectra, spectral indices are calculated. Given observed 1D spectra of the irregularities, a theoretical analysis will be presented that allows recovery of the 3D spectrum of irregularities from the observed 1D spectra. Preliminary calculations of such 3D spectra derived from the observed C/NOFS 1D spectra will be presented.

Bust, G. S.; Rodrigues, F. S.; Psiake, M.; Kelley, M. C.; Roddy, P. A.

2009-12-01

7

Historical Seismogram Filming Project: Second Progress Report.  

Science.gov (United States)

Over 120,000 seismograms have been filmed during the first year of the Historical Seismogram Filming Project. The emphasis has been on U.S. stations of the Federal network through the year 1955. During the remainder of 1980 the emphasis will continue to b...

D. P. Glover

1980-01-01

8

Historical Seismogram Filming Project: Third Progress Report.  

Science.gov (United States)

Over 136,000 seismograms have been filmed during the first 2 years of the Historical Seismogram Filming Project. The complete files of five Federal stations have been filmed. This report discusses the current status of the project and the problems encount...

D. P. Glover, H. Meyers

1981-01-01

9

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

10

Historical Seismogram Filming Project: Fourth Progress Report.  

Science.gov (United States)

World Data Center A for Solid Earth Geophysics has collected, microfilmed, and archived historical seismograms from selected seismograph stations and earthquakes worldwide. The purpose of this project is to preserve and archive historically important seis...

D. P. Glover, H. Meyers

1982-01-01

11

Model-Based Signal Processing: Correlation Detection With Synthetic Seismograms  

Science.gov (United States)

Recent applications of correlation methods to seismological problems illustrate the power of coherent signal processing applied to seismic waveforms. Examples of these applications include detection of low amplitude signals buried in ambient noise and cross-correlation of sets of waveforms to form event clusters and accurately measure delay times for event relocation and/or earth structure. These methods rely on the exploitation of the similarity of individual waveforms and have been successfully applied to large sets of empirical observations. However, in cases with little or no empirical event data, such as aseismic regions or exotic event types, correlation methods with observed seismograms will not be possible due to the lack of previously observed similar waveforms. This study uses model-based signals computed for three-dimensional (3D) Earth models to form the basis for correlation detection. Synthetic seismograms are computed for fully 3D models estimated from the Markov Chain Monte-Carlo (MCMC) method. MCMC uses stochastic sampling to fit multiple seismological data sets. Rather than estimate a single "optimal" model, MCMC results in a suite of models that sample the model space and incorporates uncertainty through variability of the models. The variability reflects our ignorance of Earth structure, due to limited resolution, data and modeling errors, and produces variability in the seismic waveform response. Model-based signals are combined using a subspace method where the synthetic signals are decomposed into an orthogonal basis by singular-value decomposition (SVD) and the observed waveforms are represented with a linear combination of a sub-set of eigenvectors (signals) associated with the most significant eigenvalues. We have demonstrated the method by modeling long-period (80-10 seconds) regional seismograms for a moderate (M~5) earthquake near the China-North Korea border. Synthetic seismograms are computed with the Spectral Element Method for a suite of long-wavelength (2 degree) seismic velocity models based on the MCMC method. We are working on higher resolution (1 degree) models for the same region and methods to increase the frequency content of the synthetic seismograms using both 1D reflectivity synthetics and 3D synthetics with a recently developed elastic finite difference code.

Rodgers, A.; Harris, D.; Pasyanos, M.; Blair, S.; Matt, R.

2006-12-01

12

Parameter Analysis For A High-Gain Harmonic Generation FEL By Numerical Calculation Based On 1D Theory  

CERN Document Server

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

Li, Yuhui; Zhang, Shancai

2004-01-01

13

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

CERN Document Server

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

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

2012-01-01

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Historical Seismogram Filming Project: First Progress Report.  

Science.gov (United States)

World Data Center A for Solid Earth Geophysics is engaged in a project of microfilming historical seismograms (1897 to 1963) and related data from a global distribution of stations. This project was initiated in response to the concern of many seismologis...

H. Meyers, W. H. K. Lee

1979-01-01

15

Synthetic seismograms - II. Synthesis of amplitude spectra and seismograms of P waves from underground nuclear explosions  

International Nuclear Information System (INIS)

As a part of programme of seismic detection of underground nuclear explosions, step by step variations in the amplitude spectra and waveforms of P wave signal, as it propagates from source to receiver region, are investigated. Influences on the amplitude spectra and waveforms of teleseismic p waves due to : (1) variation in the shape of reduced displacement potential, (2) variation of mantle Q values, (3) change in depth, (4) various yields, (5) spalling, and (6) variation of crustal structure at source as well as at receiver are studied. The results show that for a yield of 85 kilotons, the time structure of seismograms is nearly same for four types of reduced displacement potentials considered here. The duration of waveforms is affected both by crustal structure at source as well as due to spalling. In general, effect of receiver crust on seismograms is found to be minor. Synthesized and observed P wave seismograms for Longshot, Milrow and Cannikin underground nuclear explosions are computed at various seismometer array stations of the UKAEA. Computed seismograms compare well with the recorded ones. It is seen that: (1) overburden P wave velocity inferred from seismograms is less as compared to its value obtained from on-site measurements, and (2) the source function, the source crust transfer function, the mantle transfer function and the spalling function are the most important factors that influence shaping of spectra and seismograms. (M.G.B.)

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SOSA: A tool for seismogram retrieval and analysis.  

Science.gov (United States)

Currently, analysis of synthetic seismograms and comparison to observed seismograms requires multiple tools to gather disparate sources of information and run various analysis routines. The SOSA application (Synthetic and Observed Seismogram Analysis) seeks to combine common tasks into a single software application. The tool enables scientists to retrieve observed seismograms accessible through a DHI (Data Handling Interface) and seismograms saved locally or accessible through an SRB (Storage Resource Broker). DHI implementations currently provide access to the IRIS DMC, the University of South Carolina, the Northern California Earthquake Data Center at Berkeley and the Southern California Earthquake Data Center at Caltech. Retrieved seismograms include the instrument signal and station information with instrument response. Seismograms retrieved from any source can be processed together, allowing easy comparison between synthetics and observed seismograms. Existing processing abilities include re-sampling, filtering, rotation, convolution/deconvolution with instrument response and correlation between seismograms. Scientists may save seismograms into SAC or mSEED format. The utility of the application will be demonstrated and future directions discussed.

Muench, J.; Maechling, P.; Kamb, L.; Ahern, T.

2004-12-01

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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

18

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

19

Broadband CyberShake Platform: Seismogram Synthesis for Broadband Physics-Based Probabilistic Seismic Hazard Analysis  

Science.gov (United States)

Researchers at the Southern California Earthquake Center (SCEC) have developed the CyberShake computational platform to perform probabilistic seismic hazard analysis (PSHA) in the Los Angeles region (Graves et al., 2010) using deterministic wave propagation simulations at frequencies up to 0.5 Hz. CyberShake uses seismic reciprocity to calculate synthetic seismograms for a suite of more than 600,000 rupture realizations. From this set of seismograms we compute intensity measures, which are then combined into a PSHA hazard curve for the site of interest. SCEC has also developed the SCEC Broadband Ground Motion Simulation Platform, a software system that can calculate broadband seismograms at frequencies up to 10 Hz for historical and scenario earthquakes using multiple earthquake rupture generators, multiple low- and high-frequency wave propagation simulation codes, and multiple site effects modules. Here we report how we have integrated the high-frequency computational capabilities of the SCEC Broadband Platform into CyberShake, producing the Broadband CyberShake Platform. The Broadband CyberShake Platform extends the frequency range up to 10 Hz by combining low frequency deterministic synthetic seismograms with higher frequency stochastic seismograms. We can now calculate physics-based seismograms and PSHA hazard curves for intensity measures such as PGA that are strongly dependent on higher frequency ground motions. A potential benefit of this approach, particularly at higher frequencies, is that given adequate sampling of the parameter space, the physics-based model naturally limits the upper bound of the estimated ground motion response. This often leads to a reduction in hazard at longer return periods. We are applying the computational capabilities of the SCEC Broadband CyberShake Platform at southern California sites selected to support validation of this newly developed PSHA computational technique. This includes calculation of Broadband CyberShake seismograms at Southern California Seismic Network station locations for comparison with observations for well-observed Southern California earthquakes, as well as calculation of Broadband CyberShake hazard curves at precariously balanced rock sites to validate our technique and to investigate the impact of higher frequencies on these fragile geological structures.

Callaghan, S.; Maechling, P. J.; Small, P.; Milner, K.; Graves, R. W.; Jordan, T. H.; CyberShake Collaboration

2011-12-01

20

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

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

Mansingka, Abhinav S.

2012-10-07

 
 
 
 
21

Inventory of Filmed Historical Seismograms and Station Bulletins at World Data Center A.  

Science.gov (United States)

In 1979, World Data Center A for Solid Earth Geophysics began the Historical Seismogram Filming Project with the objective of preserving seismograms dating from the beginning of the instrumental era in seismology. Realizing the importance of that project ...

D. P. Glover, H. Meyers, R. B. Herrmann, M. Whittington

1985-01-01

22

Blind deconvolution of seismograms regularized via minimum support  

Science.gov (United States)

The separation of earthquake source signature and propagation effects (i.e. the Earth’s Green’s function) that encode a seismogram is a challenging problem in seismology, and is termed blind deconvolution. By considering records of multiple earthquakes at a given station that share the same Green’s function, we can write the linear relation uk(t) ? sj(t) - uj(t) ? sk(t) = 0 where uk is the seismogram for the kth source and sj is the jth unknown source. The symbol ? represents the convolution operator. Using two or more seismograms, we obtain a homogeneous linear system where the unknowns are the sources (note from symmetry, we might equally well consider seismograms representing the same source but different Green’s functions and consider the Green’s functions as unknowns). This system is augmented through specification of scale to deliver a non-trivial solution. Two issues require careful consideration for this problem to be solved. First, source durations are not known a priori and must be determined. If the specified source duration is too short, the system becomes over-determined, and if it is too long, the system is under-determined. Accordingly, we introduce source durations as unknowns and solve the combined system (sources and source durations) using separation of variables (Golub & Pereyra, 1973) regularized such that source durations are the shortest necessary to solve the system, i.e. minimum support. The solution is derived iteratively using least squares to recover the sources and the Gauss-Newton algorithm to recover source durations. Second, to resolve realistic signals requires seismograms and solutions of dimension ?104, hence iterative matrix inversion (LSQR) has been employed in conjunction with fast matrix multiplication operators based on the Fast Fourier Transform (FFT). This method has been tested using synthetic seismograms created by convolution of random sources with simplified Green’s functions and added noise. In numerical simulations to date, the method accurately recovers sources at noise levels up to 10% peak signal strength. Results from more realistic synthetic simulations and applications to real data will be presented.

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

2010-12-01

23

On-demand synthetic seismograms from the IRIS DMC  

Science.gov (United States)

The IRIS Data Management Center (DMC) has served waveform data to the seismology community for over 30 years. This presentation highlights a new, on-demand synthetic seismogram service that will complement the observation-based data we have traditionally distributed. We are computing a global-scale database of Green's functions from which users can request synthetic seismograms for arbitrary source and receiver parameters and Earth models. The multi-terabyte scale database of Green's functions is computed by the spectral-element method AxiSEM for a selection of spherically symmetric Earth models (PREM, IASP91, AK135) with anisotropy and attenuation. The resolution of the simulations will be between 2-8 to about 100 sec periods (final resolution to be determined by computational resources available). The synthetics are accessible using a simple web service that returns synthetics according to specified source-receiver combination, Earth model and signal band. On-the-fly post-processing such as convolution with a moment tensor (or specified Global CMT solution) and source-time function is being developed. This service is intended to return synthetic seismograms quickly, making it useful for studying variations in source properties, Earth models or temporal changes in instrument responses. It is also designed to be callable by simple scripts and works well in automated processing. The DMC will also provide a command line script to download selections of synthetics. This new dataset and related service provide a powerful tool in multiple areas of study where synthetic seismograms are useful.

Hutko, A. R.; Trabant, C. M.; Karstens, R.; Nissen-Meyer, T.; Bahavar, M.

2013-12-01

24

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

25

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

Directory of Open Access Journals (Sweden)

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

Milton P. Plasencia Linares

2005-11-01

26

Analytical computation of three-dimensional synthetic seismograms by Modal Summation: method, validation and applications  

Science.gov (United States)

In order to enable realistic and reliable earthquake hazard assessment and reliable estimation of the ground motion response to an earthquake, three-dimensional velocity models have to be considered. The propagation of seismic waves in complex laterally varying 3D layered structures is a complicated process. Analytical solutions of the elastodynamic equations for such types of media are not known. The most common approaches to the formal description of seismic wavefields in such complex structures are methods based on direct numerical solutions of the elastodynamic equations, e.g. finite-difference, finite-element method, and approximate asymptotic methods. In this work, we present an innovative methodology for computing synthetic seismograms, complete of the main direct, refracted, converted phases and surface waves in three-dimensional anelastic models based on the combination of the Modal Summation technique with the Asymptotic Ray Theory in the framework of the WKBJ - approximation. The three - dimensional models are constructed using a set of vertically heterogeneous sections (1D structures) that are juxtaposed on a regular grid. The distribution of these sections in the grid is done in such a way to fulfill the requirement of weak lateral inhomogeneity in order to satisfy the condition of applicability of the WKBJ - approximation, i.e. the lateral gradient of the parameters characterizing the 1D structure has to be small with respect to the prevailing wavelength. The new method has been validated comparing synthetic seismograms with the records available of three different earthquakes in three different regions: Kanto basin (Japan) triggered by the 1990 Odawara earthquake Mw= 5.1, Romanian territory triggered by the 30 May 1990 Vrancea intermediate-depth earthquake Mw= 6.9 and Iranian territory affected by the 26 December 2003 Bam earthquake Mw= 6.6. Besides the advantage of being a useful tool for assessment of seismic hazard and seismic risk reduction, it is characterized by high efficiency, in fact, once the study region is identified and the 3D model is constructed, the computation, at each station, of the three components of the synthetic signal (displacement, velocity, and acceleration) takes less than 3 hours on a 2 GHz CPU.

La Mura, Cristina; Gholami, Vahid; Panza, Giuliano F.

2013-04-01

27

A kinetic study on singlet molecular oxygen (O{sub 2}({sup 1d}elta{sup g})) generation and quenching by dihydroxynapthalenes  

Energy Technology Data Exchange (ETDEWEB)

Anaerobic photo-oxidation of a series of dihydroxynapthalenes (DHN)was studied.It was found that the interaction of O{sub 2}({sup 1d}elta{sup {sub g}}) yielded a quenching rate constant, the range depending on solvent polarity, pH, and substitution pattern of the DHN. The mechanism of the interaction appeared to be mediated by an encounter complex with a considerable charge transfer component, similar to the photo-oxidative kinetic behavior of simple substituted phenols and dihydroxybenzenes. DHN were found to be highly reactive towards O{sub 2}({sup 1d}elta{sup {sub g}}) when the hydroxy groups are ionized. Various tests indicated that DHN are good candidates for an environmental O{sub 2}({sup 1d}elta{sub g})-mediated photo-oxidation. 27 refs., graphs.

Luiz, M. [Universidad Nacional de La Patagonia, San Juan Bosco (Argentina); Soltermann, A. T.; Biasutti, A.; Garcia, N. A. [Universidad Nacional de Rio Cuarto, Rio Cuarto (Argentina)

1996-01-01

28

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.

Luo, Yinhe; Xia, Jianghai; Liu, Jiangping; Xu, Yixian; Liu, Qingsheng

2008-04-01

29

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Bagus Jaya Santosa

2012-01-01

30

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

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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

31

Source mechanisms and near-source wave propagation from broadband seismograms  

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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

32

Generating virtual textile composite specimens using statistical data from micro-computed tomography: 1D tow representations for the Binary Model  

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A Monte Carlo algorithm is defined for generating replicas of textile composite specimens that possess the same statistical characteristics as specimens imaged using high resolution computed tomography. The textile reinforcement is represented by one-dimensional tow loci in three-dimensional space, which are easily incorporated into the Binary Model of textile composites. A tow locus is expressed as the sum of non-stochastic, periodic variations in the coordinates of the tow centroid and stochastic, non-periodic deviations. The non-stochastic variations have period commensurate with the dimensions of the unit cell of the textile, while the stochastic deviations, which describe geometrical defects, exhibit correlation lengths that may be incommensurate with the unit cell. The model is calibrated with data deduced in prior work from computed tomography images. The calibration obviates the need for assuming any ideal shape functions for the tow loci, which can take very general form. The approach is therefore valid for a wide range of textile architectures. Once calibrated, a Markov Chain algorithm can generate numerous stochastic replicas of a textile architecture very rapidly. These virtual specimens can be much larger than the real specimens from which the data were originally gathered, a necessary feature when real specimen size is limited by the nature of high resolution computed tomography. The virtual specimen generator is illustrated using data for an angle interlock weave.

Blacklock, Matthew; Bale, Hrishikesh; Begley, Matthew; Cox, Brian

2012-03-01

33

Investigations of historical seismograms of the 1956 Amorgos-Santorini earthquake (Greece, Ms=7.4)  

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The digitization of historical seismograms allows to gain new information about important earthquakes that occurred in the first part of the 20th century. On July 9, 1956 a strong earthquake occurred between the islands Amorgos and Santorini within the volcanic arc of the Hellenic Subduction Zone. A second strong earthquake followed just SW of the first event about 13 minutes later. Both earthquakes caused severe damages on the surrounding islands. A tsunami, with a maximum wave height of 30 m at the south coast of Amorgos caused damages within a region of 100 km. Available focal mechanisms of the first event vary from strike-slip to normal faulting. The focal depth of the first event is estimated to 10 (+/-10) km. Depth estimates for the second event vary between 40 and 100 km. This suggests a re-examination of the events. It was possible to collect more than 80 analogue seismograms of 30 seismic stations from Belgium, Denmark, Germany, Italy, Croatia, Malta, Austria, Poland, Romania, Switzerland, Spain and Turkey. On all seismograms the first main shock is visible in various qualities, while the second main shock can be clearly observed at 3 stations. The stations, for which useful digitized waveforms are available, are at a distance from 247 km up to 2337 km with a azimuthal coverage of 120°. The digitization and correction of the suitable seismograms was done by applying the program TESEO (developed by INGV, Rome). The seismograms of the first event show large surface wave amplitudes, while the surface waves are missing at the second event. The frequency content of the digitized seismograms is investigated using a multiple filter technique (MFT). MFT calculations show clearly the P and S wave as well as the dispersion of the surface wave of the first event. Synthetic waveforms are calculated for various depths down to 160 km and different moment tensors with the program GEMINI. Instrument corrected synthetic seismograms may be fitted to digitized recordings in order to constrain the moment tensors and focal depths of the two events by waveform inversion.

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

2009-04-01

34

Correlation of borehole and seismic data in the Gulf of Alaska through synthetic seismograms: Preliminary results from IODP Expedition 341  

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During IODP Expedition 341, a transect of sites was drilled in the Gulf of Alaska across the shelf and slope, continuing as far as the distal Surveyor Fan, in order to investigate the sedimentary record from a period of changing climate during the Pliocene-Pleistocene that led to the glaciation of the southern Alaskan margin. A major objective of this expedition was to drill through a series of seismically-resolved sedimentary sequences and use the resulting record to study provenance, paleoclimate and glacimarine indicators, and ultimately to link the record to the tectonic and climatic history of the region. Wireline logging data are important for making borehole to seismic correlations, by providing a time-depth relationship for each logged site and geophysical characterization of the drilled sequences. Four sites were logged during the expedition, measuring natural gamma ray, bulk density, magnetic susceptibility, electrical resistivity, and sonic velocity. These data provide information on physical properties of the drilled sediments at an intermediate resolution, between the centimeter scale of core data and the meter to kilometer scale of seismic data. Velocity data are critical for correlating features measured in the depth domain (e.g., cores and logs) to features measured in the time domain (e.g., seismic reflections). Using P-wave velocity and bulk density data to construct a synthetic seismogram, a time-depth relationship can be determined for each site. Data from cores are limited by core recovery and can fail to capture properties at the seismic scale, while data from logging are limited to the logged interval (typically below ~100 mbsf) and can require post-cruise processing to recover the best quality logs. Composite velocity and density records can be constructed using both core and log data, and reflection coefficients can then be calculated and convolved with a seafloor wavelet to generate a site-specific synthetic seismogram. The synthetic seismogram can be compared with seismic data in the vicinity of each borehole to establish the best time-depth relationship for the site. Preliminary shipboard integration of core, log, and seismic data indicate that distinct changes in lithology and logging data often coincide with significant seismic reflections or boundaries between primary seismic units. These results suggest that prominent seismic reflections may be associated with the presence of cemented sediments and increased clast abundance/size, among other things, that are observed in this glacially influenced sedimentary environment. Using synthetic seismograms to determine time-depth relationships, detailed records from cores and logs can be accurately related to seismic stratigraphic features, and interpretation can be extended from individual boreholes into the large number of seismic profiles of different resolutions that have been collected throughout the Gulf of Alaska.

Slagle, A. L.; Worthington, L. L.; Drab, L.; Gulick, S. P.

2013-12-01

35

YASEIS: Yet Another computer program to calculate synthetic SEISmograms for a spherically multi-layered Earth model  

Science.gov (United States)

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

Ma, Yanlu

2013-04-01

36

Digitization Procedures of Analogue Seismograms from the Adam Dziewonski Observatory (HRV) at Harvard, MA  

Science.gov (United States)

This project explores methods of digitization of analogue seismic recordings for better preservation and to facilitate data distribution to the community. Different techniques are investigated using seismograms from one particular station, the Adam Dziewonski Observatory (HRV) at Harvard, Massachusetts. This seismological station, still in operation as a part of the Global Seismographic Network today, is one of the oldest stations in the United States. The station was built in 1933, and since its installation, the station has produced approximately 16,000 analogue seismograms. The majority of these recordings were taken between 1933 and 1953, with some intermittent recordings between 1962 and 1998 after digital seismometers had become a standard. These analogue seismograms have the potential of expanding the database for seismological research such as identification of events previously not catalogued. Due to poor storage environment at the station, some of the records, especially those on regular type of paper, are damaged beyond repair. Nevertheless, many of the records on photographic paper are in better condition, and we have focused on a subset of these recordings that are least damaged. Even these seismograms require cleaning and, in consultation with the Weissman Preservation Center of Harvard Library, preparation techniques for the photographic records are examined. After the seismograms are cleaned and flattened, three different equipments are investigated for digitization, i.e., a copy machine, scanner, and camera. These instruments allow different imaging resolutions, ranging from 200 dots per inch (dpi) to 800 dpi. The image resolution and the bit depth have a wide range of implications that are closely linked to the digitization program one chooses to convert the image to time series. We explore three different software for this conversion, SeisDig (Bromirski and Chuang, 2003), Teseo2 (Pintore and Quintiliani, 2008), and NeuraLog (www.neuralog.com), and determine advantages and disadvantages associated with each software. One of the important features of the software is the automatic tracing algorithms. The success of the automatic tracing depends upon many factors, and this is examined using examples from long and short period recordings with high amplitude (thin and fading lines), and long and short period recordings with low amplitude (well-defined lines). Automatically traced data are also compared to manually traced samples. Based upon these results, we propose a set of procedures and recommendations for cleaning, imaging scheme including resolution and bit depth, and digitization software. Ultimately, we would like to outline a robust procedure for mass seismogram digitization and process all the Harvard station recordings and make them available to the community through the IRIS Data Management Center.

Torpey, M.; Ishii, M.

2010-12-01

37

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

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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

38

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

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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

39

The damping of seismic waves and its determination from reflection seismograms  

Science.gov (United States)

The damping in theoretical waveforms is described phenomenologically and a classification is proposed. A method for studying the Earth's crust was developed which includes this damping as derived from reflection seismograms. Seismic wave propagation by absorption, attenuation of seismic waves by scattering, and dispersion relations are considered. Absorption of seismic waves within the Earth as well as reflection and transmission of elastic waves seen through boundary layer absorption are also discussed.

Engelhard, L.

1979-01-01

40

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

 
 
 
 
41

Three-component seismogram envelope synthesis in randomly inhomogeneous semi-infinite media based on the single scattering approximation  

Science.gov (United States)

We present a method for synthesizing three-component seismogram envelopes of local earthquake in a randomly inhomogeneous semi-infinite medium. The method extends the single scattering model of Sato [Sato, H., 1984. Attenuation and envelope formation of three-component seismograms of small local earthquakes in randomly inhomogeneous lithosphere. J. Geophys. Res. 89: 1221-1241.] by incorporating the effects of a free surface, frequency-dependent non-spherical radiation from a double-couple point source, and non-isotropic scattering including wave-type conversion. We synthesize seismogram envelopes—the root-mean-square (rms) amplitude of seismograms—at a receiver located on the free surface by dividing an inhomogeneous medium into many small cells and summing the energy of scattered waves from the cells on the isochronal scattering shells of different scattering modes for a given lapse time. Our main focus is the free surface effect, which alters the shape of isochronal scattering shells and the amplitudes of incident waves. Synthesizing three-component seismogram envelopes for different source-receiver configurations, we find that these effects on seismogram envelopes are not negligible and are pronounced at early S coda. P coda envelope shape is not very sensitive to free-surface incorporation because of dominant SP scattered waves which come from the source direction.

Yoshimoto, Kazuo; Sato, Haruo; Ohtake, Masakazu

1997-02-01

42

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

43

Generation of stable 'low phytic acid' transgenic rice through antisense repression of the 1D-myo-inositol 3-phosphate synthase gene (RINO1) using the 18-kDa oleosin promoter.  

Science.gov (United States)

Phytic acid acts as the major storage form of phosphorus in plant seeds and is poorly digested by monogastric animals. The degradation of phytic acid in animal diets is necessary to overcome both environmental and nutritional issues. The enzyme 1D-myo-inositol 3-phosphate [Ins(3)P(1)] synthase (EC 5.5.1.4) catalyses the first step of myo-inositol biosynthesis and directs phytic acid biosynthesis in seeds. The rice Ins(3)P(1) synthase gene (RINO1) is highly expressed in developing seed embryos and in the aleurone layer, where phytic acid is synthesized and stored. In rice seeds, 18-kDa oleosin (Ole18) is expressed in a seed-specific manner, and its transcripts are restricted to the embryo and the aleurone layer. Therefore, to effectively suppress phytic acid biosynthesis, antisense RINO1 cDNA was expressed under the control of the Ole18 promoter, directing the same spatial pattern in seeds as RINO1 in transgenic rice plants. The generated transgenic rice plants showed strong 'low phytic acid' (lpa) phenotypes, in which seed phytic acid was reduced by 68% and free available phosphate was concomitantly increased. No negative effects on seed weight, germination or plant growth were observed. The available phosphate levels of the stable transgenic plants surpassed those of currently available rice lpa mutants. PMID:19021878

Kuwano, Mio; Mimura, Tetsuro; Takaiwa, Fumio; Yoshida, Kaoru T

2009-01-01

44

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

45

The Seismic Wavefield, Volume II: Interpretation of Seismograms on Regional and Global Scales  

Science.gov (United States)

Volume II of Brian Kennett's book, The Seismic Wavefield, is entitled “Interpretation of Seismograms on Regional and Global Scales.” The first volume in this series is entitled “Introduction and Theoretical Development,” and was published in 2001. The current volume is divided into three parts, 17 chapters, and an appendix. By way of numerous observations and illustrations, this volume introduces the reader to the various regional and global seismic phases. Here is where one learns how to distinguish Pn from Pg, how to unravel the PKP traveltime branches, and where to look for Love. The writing is clear and concise, the references are plentiful, and the quality of the figures is excellent.

Tromp, Jeroen

46

The application of generalized fractal in arrival time detection of seismograms  

International Nuclear Information System (INIS)

Based on the energy features of seismic signals and generalized fractal, a novel algorithm of arrival time detection for seismogram was presented in this paper. The change of intercept of Mandel-brot-Richardson curve can be used to estimate arrival time of seismic signal accurately. A new pre-processing method was also proposed, which can increase the signal to noise ratio of weak seismic signals and not influence the first break of signals. In order to detect arrival time of signals automatically, the intercept curve was corrected using a method that similarly to coordinate rotation. (authors)

47

The Coupled Spectral Element/Normal Mode Method: Application to the Testing of Several Approximations Based on Normal Mode Theory for the Computation of Seismograms in a Realistic 3D Earth.  

Science.gov (United States)

The spectral element method (SEM) has recently been adapted successfully for global spherical earth wave propagation applications. Its advantage is that it provides a way to compute exact seismograms in a 3D earth, without restrictions on the size or wavelength of lateral heterogeneity at any depth, and can handle diffraction and other interactions with major structural boundaries. Its disadvantage is that it is computationally heavy. In order to partly address this drawback, a coupled SEM/normal mode method was developed (Capdeville et al., 2000). This enables us to more efficiently compute bodywave seismograms to realistically short periods (10s or less). In particular, the coupled SEM/normal mode method is a powerful tool to test the validity of some analytical approximations that are currently used in global waveform tomography, and that are considerably faster computationally. Here, we focus on several approximations based on normal mode perturbation theory: the classical "path-average approximation" (PAVA) introduced by Woodhouse and Dziewonski (1984) and well suited for fundamental mode surface waves (1D sensitivity kernels); the non-linear asymptotic coupling theory (NACT), which introduces coupling between mode branches and 2D kernels in the vertical plane containing the source and the receiver (Li and Tanimoto, 1993; Li and Romanowicz, 1995); an extension of NACT which includes out of plane focusing terms computed asymptotically (e.g. Romanowicz, 1987) and introduces 3D kernels; we also consider first order perturbation theory without asymptotic approximations, such as developed for example by Dahlen et al. (2000). We present the results of comparisons of realistic seismograms for different models of heterogeneity, varying the strength and sharpness of the heterogeneity and its location in depth in the mantle. We discuss the consequences of different levels of approximations on our ability to resolve 3D heterogeneity in the earth's mantle.

Capdeville, Y.; Gung, Y.; Romanowicz, B.

2002-12-01

48

Focal mechanism and depth of the 1956 Amorgos twin earthquakes from waveform matching of analogue seismograms  

Science.gov (United States)

Historic analogue seismograms of the large 1956 Amorgos twin earthquakes which occurred in the volcanic arc of the Hellenic subduction zone (HSZ) were collected, digitized and reanalyzed to obtain refined estimates of their depth and focal mechanism. In total, 80 records of the events from 29 European stations were collected and, if possible, digitized. In addition, bulletins were searched for instrument parameters required to calculate transfer functions for instrument correction. A grid search based on matching the digitized historic waveforms to complete synthetic seismograms was then carried out to infer optimal estimates for depth and focal mechanism. Owing to incomplete or unreliable information on instrument parameters and frequently occurring technical problems during recording, such as writing needles jumping off mechanical recording systems, much less seismograms than collected proved suitable for waveform matching. For the first earthquake, only seven seismograms from three different stations at Stuttgart (STU), Göttingen (GTT) and Copenhagen (COP) could be used. Nevertheless, the waveform matching grid search yields two stable misfit minima for source depths of 25 and 50 km. Compatible fault plane solutions are either of normal faulting or thrusting type. A separate analysis of 42 impulsive first-motion polarities taken from the International Seismological Summary (ISS bulletin) excludes the thrusting mechanism and clearly favors a normal faulting solution with at least one of the potential fault planes striking in SW-NE direction. This finding is consistent with the local structure and microseismic activity of the Santorini-Amorgos graben. Since crustal thickness in the Amorgos area is generally less than 30 km, a source depth of 25 km appears to be more realistic. The second earthquake exhibits a conspicuously high ratio of body wave to surface wave amplitudes suggesting an intermediate-depth event located in the Hellenic Wadati-Benioff zone. This hypothesis is supported by a focal mechanism analysis based on first-motion polarities, which indicates a mechanism very different from that of the first event. A waveform matching grid search done to support the intermediate-depth hypothesis proved not to be fruitful because the body wave phases are overlain by strong surface wave coda of the first event inhibiting a waveform match. However, body to surface wave amplitude ratios of a modern intermediate-depth event with an epicenter close to the island of Milos observed at stations of the German Regional Seismic Network (GRSN) exhibit a pattern similar to the one observed for the second event with high values in a frequency band between 0.05 Hz and 0.3 Hz. In contrast, a shallow event with an epicenter in western Crete and nearly identical source mechanism and magnitude, shows very low ratios of body and surface wave amplitude up to 0.17 Hz and higher ratios only beyond that frequency. Based on this comparison with a modern event, we estimate the source depth of the second event to be greater than 100 km. The proximity in time and space of the two events suggests a triggering of the second, potentially deep event by the shallow first one.

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

2014-10-01

49

Parameters of Higuchi's method to characterize primary waves in some seismograms from the Mexican subduction zone  

Science.gov (United States)

Higuchi's method is a procedure that, if applied appropriately, can determine in a reliable way the fractal dimension D of time series; this fractal dimension permits to characterize the degree of correlation of the series. However, when analyzing some time series with Higuchi's method, there are oscillations at the right-hand side of the graph, which can cause a mistaken determination of the fractal dimension. In this work, an appropriate explanation is given to this type of behaviour. Using the seismogram as a time series and the properties of the P and S waves, it is possible to use the properties of Higuchi's method to previously detect the arrival of the earthquake shacking stage, some seconds in advance, approximately 30-35 s in the case of Mexico City. Thus, we propose the Higuchi's method to characterize and detect the P waves in order to estimate the strength of the forthcoming S waves.

Gálvez-Coyt, Gonzalo; Muñoz-Diosdado, Alejandro; Peralta, José A.; Balderas-López, José A.; Angulo-Brown, Fernando

2012-06-01

50

Tomography S Velocity Structure between Washington’s Earthquake C022801l and Observational Station Tuc through Seismogram Analysis  

Directory of Open Access Journals (Sweden)

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

Bagus Jaya Santosa

2005-11-01

51

Time-domain solutions for nonlinear elastic 1-D plane wave propagation  

Energy Technology Data Exchange (ETDEWEB)

Time-domain solutions are obtained for 1-D nonlinear elastic wave propagation problems using a five-constant nonlinear theory. The assumption of weak attenuation was used throughout the development. The strongest nonlinear effects are obtained for the case of single compressional wave propagation, for single compressional or shear wave propagation through a longitudinally pre-stressed elastic material, and for shear wave propagation in a shear pre-stressed elastic material. Estimates of the size of these effects indicate that nonlinear phenomena are likely to be observable in real seismic data. The results may be useful for the measurement of nonlinear constants in elastic materials, for explaining the frequency content of seismograms, and for monitoring strain fields in the earth`s crust.

Korneev, V.A.

1998-06-01

52

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

53

A Multi-scale Approach to 1-D Finite-Frequency Inversions  

Science.gov (United States)

One-dimensional velocity models are representative of regional tectonic units. They are important in determining the locations and focal mechanisms of earthquakes, and provide initial models for tomographic studies. However, resolution of velocity models are quite dependent on the distribution of stations and earthquakes. Making use of finite-frequency travel-times which afford better resolution on the velocity structures, we formulated a multi-scale approach to reveal 1-D model from a single or more seismogram of local records. From a series of synthetic tests, it shows how 1-D multi-scale velocity models could be obtained from data with limited quality. Sensitivity kernels to parameters involved in the model, such as P- and S-wave speeds and depths of seismic discontinuities, are computed numerically by perturbing the reference model and measuring the resulting travel-times. An iterative inversion is carried out with updates of travel-time and amplitude measurements and sensitivity kernels following each iteration. According to the resolution of different phases and their Fréchet kernels, models at different scales were determined to explain the corresponding parts of data. In a synthetic test we reconstructed the input model into a series of reasonable models with multiple scale levels, assuming this method to be accurate and quickly in modeling 1-D structures from limited local records. This approach was also applied to the inversions of velocity structures in South Africa using real seismic records from Kimberley Array, revealing lateral structural variations in Kaapvaal Craton.

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

2011-12-01

54

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

55

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

56

Computation of Three Component Receiver Functions (R3) by Beamforming of Optimal Regional Vertical Component Seismograms Before Simultaneous Iterative Deconvolution  

Science.gov (United States)

In receiver function (RF) analysis, we interpret Ps conversions and reverberations from broadband seismograms of teleseismic events (from 30 to 90 degrees away). To produce RFs, the horizontal component of the seismogram is deconvolved by the vertical (which, because of the near vertical ray paths, are assumed to be the P-source function). Noise in the vertical component (i.e. scattering from localized 3-D structure, s-waves energy, ambient noise, etc.) will result in a noisy horizontal RF with possible spurious peaks. Many investigators produce RFs by rotating the seismograms into the presumed or derived ray path of the P-wave (L-component) prior to deconvolution. Our goal is to make a cleaner RF by way of beamforming to produce the cleanest P-waveform from the seismogram before deconvolution. Rather than using a reference model to compute delay time for beamforming, cross-correlation will be used to compute delay times of the P-wave across stations. A regional wave-front will be fit to the time delays to estimate a regionally corrected backazimuth (BAZ) and ray parameter. This data derived BAZ and ray parameter will be used to rotate the seismograms into the P-ray path (L-component). A cleaner estimate of the incoming P-waveform can be made by beamforming the vertical component of the seismogram from a given station with those recorded at neighboring stations (from upwards of three hundred km away). The time delays derived from cross-correlation will be used to align P-wave recordings from stations as much as 300 km away. This beamed vertical component is then averaged from stations across different geological terrains. As a result, local variation in delay times of P reverberations will not be coherent across stations and stacking (beaming) will remove these P-reverberations from the beamed P component (assumed source function). Further improvement can be made by producing a correlation matrix for all shifted P-waveforms from each station and excluding those with low correlation coefficients from the beam. Because we have removed (or minimized) the P-reverberations from the source function (L component), it becomes necessary to rotate all three components to be parallel with the P-wave ray parameter to minimize the amplitudes of P-reverberations on the SV and SH components. We then deconvolve all three components of the rotated local seismogram by the beamed vertical component and produce a three component receiver function (RF3). The vertical component of the RF3 will contain local P-reverberations, thereby contributing P-arrival times that are independent of the Vp/Vs ratio. When combined with radial (Ps) components of the RF3, this can reduce the ambiguity in trade-off between estimates of depth and Vp/Vs ratio to a given horizon. This method of computing RF3s will be tested in both areas of complex geology (southern California) and relatively simple geology (midcontinent USA). Comparison of RF3s with traditional receiver functions may yield better interpretations than using either method independently.

Pratt, K. W.; Gurrola, H.

2011-12-01

57

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

58

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

59

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

International Nuclear Information System (INIS)

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

60

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

International Nuclear Information System (INIS)

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.

 
 
 
 
61

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

Energy Technology Data Exchange (ETDEWEB)

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

Patton, H.J.; Mills, J.M. Jr.

1984-03-01

62

A 2-D spectral-element method for computing spherical-earth seismograms-II. Waves in solid-fluid media  

Science.gov (United States)

We portray a dedicated spectral-element method to solve the elastodynamic wave equation upon spherically symmetric earth models at the expense of a 2-D domain. Using this method, 3-D wavefields of arbitrary resolution may be computed to obtain Fréchet sensitivity kernels, especially for diffracted arrivals. The meshing process is presented for varying frequencies in terms of its efficiency as measured by the total number of elements, their spacing variations and stability criteria. We assess the mesh quantitatively by defining these numerical parameters in a general non-dimensionalized form such that comparisons to other grid-based methods are straightforward. Efficient-mesh generation for the PREM example and a minimum-messaging domain decomposition and parallelization strategy lay foundations for waveforms up to frequencies of 1 Hz on moderate PC clusters. The discretization of fluid, solid and respective boundary regions is similar to previous spectral-element implementations, save for a fluid potential formulation that incorporates the density, thereby yielding identical boundary terms on fluid and solid sides. We compare the second-order Newmark time extrapolation scheme with a newly implemented fourth-order symplectic scheme and argue in favour of the latter in cases of propagation over many wavelengths due to drastic accuracy improvements. Various validation examples such as full moment-tensor seismograms, wavefield snapshots, and energy conservation illustrate the favourable behaviour and potential of the method.

Nissen-Meyer, Tarje; Fournier, Alexandre; Dahlen, F. A.

2008-09-01

63

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

64

Main: 1D6R [RPSD  

Full Text Available 1D6R ?? Soybean Glycine max (L.) Merrill Bowman-Birk Type Proteinase Inhibitor Precursor Glyci ... ith Bovine Trypsin At 2.3 A Resolution. Structural Basis ... Of Janus-Faced Serine Protease Inhibitor Specifici ...

65

Chaos in 1D radiative edge plasmas  

International Nuclear Information System (INIS)

Bifurcation and chaos in radiative edge plasmas are investigated on the basis of a periodically driven reaction-diffusion equation which results from the time dependent 1d heat conduction equation including a given periodically time-modulated impurity density. The temporal problem shows the transition to chaos through the Feigenbaum route. In 1d and time dependent plasmas Hopf bifurcation and intermittency phenomena exist. The application to a carbon seeded plasma shows the existence of different oscillation regimes. (orig.)

66

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

67

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 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)

68

Upstream Design and 1D-CAE  

Science.gov (United States)

Recently, engineering design environment of Japan is changing variously. Manufacturing companies are being challenged to design and bring out products that meet the diverse demands of customers and are competitive against those produced by rising countries(1). In order to keep and strengthen the competitiveness of Japanese companies, it is necessary to create new added values as well as conventional ones. It is well known that design at the early stages has a great influence on the final design solution. Therefore, design support tools for the upstream design is necessary for creating new added values. We have established a research society for 1D-CAE (1 Dimensional Computer Aided Engineering)(2), which is a general term for idea, methodology and tools applicable for the upstream design support, and discuss the concept and definition of 1D-CAE. This paper reports our discussion about 1D-CAE.

Sawada, Hiroyuki

69

First Observation of Upsilon(1D) States  

CERN Document Server

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

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

2002-01-01

70

Main: 1D8U [RPSD  

Full Text Available 1D8U ?? Rice Oryza sativa L. Non-Symbiotic Hemoglobin 1 Name=Hb1; Synonyms=Glb1a; Oryza Sativa ... s Jr. M.Hargrove, E.A.Brucker, B.Stec, G.Sarath, R.Arredondo -Peter, R.V.Klucas, J.S.Olson, G.N.Phillips Jr. Cry ...

71

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

72

YORP torques with 1D thermal model  

CERN Document Server

A numerical model of the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect for objects defined in terms of a triangular mesh is described. The algorithm requires that each surface triangle can be handled independently, which implies the use of a 1D thermal model. Insolation of each triangle is determined by an optimized ray-triangle intersection search. Surface temperature is modeled with a spectral approach; imposing a quasi-periodic solution we replace heat conduction equation by the Helmholtz equation. Nonlinear boundary conditions are handled by an iterative, FFT based solver. The results resolve the question of the YORP effect in rotation rate independence on conductivity within the nonlinear 1D thermal model regardless of the accuracy issues and homogeneity assumptions. A seasonal YORP effect in attitude is revealed for objects moving on elliptic orbits when a nonlinear thermal model is used.

Breiter, Slawomir; Czekaj, Maria

2010-01-01

73

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

74

Pulfrich refractometer for 1-D gradients.  

Science.gov (United States)

A refractometer based on the critical angle condition was constructed and found useful for determining 1-D distributions of refractive index. The method is particularly convenient when transient liquids are tested, although it is applicable to solid samples. The device is simple and straightforward in its use, allowing realtime measurements with no additional optical system. The sensitivity can be changed with the size of the apparatus. PMID:20539598

Cervantes, M; Rodriguez-Vera, R

1988-11-01

75

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.

76

Coalescence phenomena in 1D silver nanostructures.  

Science.gov (United States)

Different coalescence processes on 1D silver nanostructures synthesized by a PVP assisted reaction in ethylene glycol at 160?°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. PMID:21828529

Gutiérrez-Wing, C; Pérez-Alvarez, M; Mondragón-Galicia, G; Arenas-Alatorre, J; Gutiérrez-Wing, M T; Henk, M C; Negulescu, I I; Rusch, K A

2009-07-22

77

Reassessment of source parameters for three major earthquakes in the East African rift system from historical seismograms and bulletins  

Directory of Open Access Journals (Sweden)

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

O. Kulhánek

2000-06-01

78

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

79

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

80

1D oxide nanostructures from chemical solutions.  

Science.gov (United States)

Nanotechnology has motivated a tremendous effort in the synthesis approaches to grow free standing or hierarchical nanomaterials such as nanowires and nanorods. Bottom-up approaches based on chemistry are an important approach to produce nanomaterials, and here the concepts of growing oxide 1D nanostructures from chemical solutions are reviewed. The thermodynamic and kinetic aspects of the nucleation and growth of oxide compounds in solutions are presented with emphasis on hydrothermal and molten salt synthesis. The importance of solubility of precursors, the precursor chemistry, role of organic additives as well as the chemical complexity and dimensionality and symmetry of the crystal structure of the compound grown are highlighted. PMID:24129769

Einarsrud, Mari-Ann; Grande, Tor

2014-04-01

 
 
 
 
81

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

82

A 1-D dusty plasma photonic crystal  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-09-21

83

$Z^+(4430)$ as a $D_1'{D}^* $ ($D_1{D}^* $) molecular state  

CERN Document Server

We reexamine whether $Z^+(4430)$ could be a $D_1'-{D}^*$ or $D_1-{D}^*$ molecular state after considering both the pion and $\\sigma$ meson exchange potentials and introducing the form factor to take into account the structure effect of the interaction vertex. Our numerical analysis with Matlab package MATSLISE indicates the contribution from the sigma meson exchange is small for the $D_1'-{D}^*$ system and significant for the $D_1-{D}^*$ system. The S-wave $D_1-\\bar{D}^*$ molecular state with only $J^{P}=0^-$ and $D_1'-{D}^*$ molecular states with $J^P=0^-,1^-,2^-$ may exist with reasonable parameters. One should investigate whether the broad width of $D_1'$ disfavors the possible formation of molecular states in the future. The bottom analog $Z_B$ of $Z^+(4430)$ has a larger binding energy, which may be searched at Tevatron and LHC. Experimental measurement of the quantum number of $Z^+(4430)$ may help uncover its underlying structure.

Liu, Xiang; Deng, Wei-Zhen; Zhu, Shi-Lin

2008-01-01

84

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)

85

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

86

Understanding 1D Electrostatic Dust Levitation  

Science.gov (United States)

Electrostatically-dominated dust motion has been hypothesized since the Lunar Horizon Glow was observed by the Surveyor spacecraft. The hypothesized occurence of this phenomenon was naturally extended to asteroids due to their small gravities. Additionally, it has been suggested that the dust ponds observed on Eros by the NEAR mission may be created by electrostatically-dominated dust transport. Previous attempts to numerically model dust motion on the Moon and Eros have been stymied by poorly understood dust launching mechanisms. As a result, the initial velocity and charge of dust particles used in numerical simulations may or may not have any relevance to the actual conditions occurring in situ. It has been seen that properly tuned initial states (velocity and charge) result in dust particles levitating above the surface in both 1D and 2D simulations. Levitation is of interest to planetary scientists since it provides a way to quickly redistribute the surface dust particles over a body. However, there is currently no method to predict whether or not a certain initial state will result in levitation. We have developed a method to provide constraints on the initial states that result in levitation as a function of dust particle size and central body gravity. Additionally, our method can be applied to several models of the plasma sheath. Thus, we limit the guesswork involved in determining which initial conditions result in levitation. We provide a more detailed understanding of levitation phenomena couched in terms of the commonly recognized spring-mass system. This method of understanding dust motion removes the dependency on the launching mechanism, which remains fraught with controversy. Once a feasible dust launching mechanism is identified (be it micrometeoroid bombardment or electrostatic lofting), our method will allow the community to quickly ascertain if dust levitation will occur in situ or if it is simply a numerical artifact. In addition to constraining the initial states that result in dust levitation, our model provides estimates of the heights and sizes of particles that could be levitated as a function of the central body gravity and plasma sheath potential profile. Thus, given a model of the plasma sheath, we can inform future missions hoping to observe levitating particles.

Hartzell, C. M.; Scheeres, D. J.

2011-12-01

87

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

88

Design, synthesis, and functional activity of labeled CD1d glycolipid agonists.  

Science.gov (United States)

Invariant natural killer T cells (iNKT cells) are restricted by CD1d molecules and activated upon CD1d-mediated presentation of glycolipids to T cell receptors (TCRs) located on the surface of the cell. Because the cytokine response profile is governed by the structure of the glycolipid, we sought a method for labeling various glycolipids to study their in vivo behavior. The prototypical CD1d agonist, ?-galactosyl ceramide (?-GalCer) 1, instigates a powerful immune response and the generation of a wide range of cytokines when it is presented to iNKT cell TCRs by CD1d molecules. Analysis of crystal structures of the TCR-?-GalCer-CD1d ternary complex identified the ?-methylene unit in the fatty acid side chain, and more specifically the pro-S hydrogen at this position, as a site for incorporating a label. We postulated that modifying the glycolipid in this way would exert a minimal impact on the TCR-glycolipid-CD1d ternary complex, allowing the labeled molecule to function as a good mimic for the CD1d agonist under investigation. To test this hypothesis, the synthesis of a biotinylated version of the CD1d agonist threitol ceramide (ThrCer) was targeted. Both diastereoisomers, epimeric at the label tethering site, were prepared, and functional experiments confirmed the importance of substituting the pro-S, and not the pro-R, hydrogen with the label for optimal activity. Significantly, functional experiments revealed that biotinylated ThrCer (S)-10 displayed behavior comparable to that of ThrCer 5 itself and also confirmed that the biotin residue is available for streptavidin and antibiotin antibody recognition. A second CD1d agonist, namely ?-GalCer C20:2 4, was modified in a similar way, this time with a fluorescent label. The labeled ?-GalCer C20:2 analogue (11) again displayed functional behavior comparable to that of its unlabeled substrate, supporting the notion that the ?-methylene unit in the fatty acid amide chain should be a suitable site for attaching a label to a range of CD1d agonists. The flexibility of the synthetic strategy, and late-stage incorporation of the label, opens up the possibility of using this labeling approach to study the in vivo behavior of a wide range of CD1d agonists. PMID:23458425

Jervis, Peter J; Polzella, Paolo; Wojno, Justyna; Jukes, John-Paul; Ghadbane, Hemza; Garcia Diaz, Yoel R; Besra, Gurdyal S; Cerundolo, Vincenzo; Cox, Liam R

2013-04-17

89

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

90

Frobenius Problem for Semigroups ${\\sl S}(d_1,d_2,d_3)$  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The matrix representation of the set $\\Delta({\\bf d}^3)$, ${\\bf d}^3=(d_1,d_2, d_3)$, of the integers which are unrepresentable by $d_1,d_2,d_3$ is found. The diagrammatic procedure of calculation of the generating function $\\Phi({\\bf d}^3;z)$ for the set $\\Delta({\\bf d}^3)$ is developed. The Frobenius number $F({\\bf d}^3)$, genus $G({\\bf d}^3)$ and Hilbert series $H({\\bf d}^3;z)$ of a graded subring for non--symmetric and symmetric semigroups ${\\sf S}({\\bf d}^3)$ are found....

Fel, Leonid G.

2004-01-01

91

Vlasov-Poisson in 1D: waterbags  

CERN Document Server

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

Colombi, Stéphane

2014-01-01

92

Vlasov-Poisson in 1D: waterbags  

Science.gov (United States)

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

Colombi, Stéphane; Touma, Jihad

2014-07-01

93

Ion-sensing properties of 1D vanadium pentoxide nanostructures  

Science.gov (United States)

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

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

2012-06-01

94

The 1D-ISAR imaging of manoeuvering aircraft  

Science.gov (United States)

Most operating radar systems don't provide sufficient range resolution to resolve flying targets in range direction. Nevertheless, high cross range resolution can be obtained by 1-D imaging. This procedure will be successful only, if the target motion is compensated with a high accuracy. A motion compensation technique is introduced based on Kalman forward-backward smoothing on radar position estimates together with spectral information. An iterative error correction procedure (autofocus) yields a cross range image with sufficient resolution. Correct scaling and estimation of the imaging axis direction are derived from the flight path by a simple orientation model. Some experimental study of this kind of ISAR processing was done with the electronic radar phased array. Echo sequences of targets of opportunity were recorded and off-line processed. With the autofocus procedure, coherence times up to 6 sec could be achieved providing resolution cells in the magnitude of 1 m. Images during straight flight periods as well as along curved flight paths were generated. The reliability of the information given by the signatures was examined.

Ender, J.

1989-10-01

95

First Observation of a Upsilon(1D) State  

CERN Document Server

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

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

2004-01-01

96

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

97

Interaction of environmental contaminants with zebrafish organic anion transporting polypeptide, Oatp1d1 (Slco1d1).  

Science.gov (United States)

Polyspecific transporters from the organic anion transporting polypeptide (OATP/Oatp) superfamily mediate the uptake of a wide range of compounds. In zebrafish, Oatp1d1 transports conjugated steroid hormones and cortisol. It is predominantly expressed in the liver, brain and testes. In this study we have characterized the transport of xenobiotics by the zebrafish Oatp1d1 transporter. We developed a novel assay for assessing Oatp1d1 interactors using the fluorescent probe Lucifer yellow and transient transfection in HEK293 cells. Our data showed that numerous environmental contaminants interact with zebrafish Oatp1d1. Oatp1d1 mediated the transport of diclofenac with very high affinity, followed by high affinity towards perfluorooctanesulfonic acid (PFOS), nonylphenol, gemfibrozil and 17?-ethinylestradiol; moderate affinity towards carbaryl, diazinon and caffeine; and low affinity towards metolachlor. Importantly, many environmental chemicals acted as strong inhibitors of Oatp1d1. A strong inhibition of Oatp1d1 transport activity was found by perfluorooctanoic acid (PFOA), chlorpyrifos-methyl, estrone (E1) and 17?-estradiol (E2), followed by moderate to low inhibition by diethyl phthalate, bisphenol A, 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4 tetrahydronapthalene and clofibrate. In this study we identified Oatp1d1 as a first Solute Carrier (SLC) transporter involved in the transport of a wide range of xenobiotics in fish. Considering that Oatps in zebrafish have not been characterized before, our work on zebrafish Oatp1d1 offers important new insights on the understanding of uptake processes of environmental contaminants, and contributes to the better characterization of zebrafish as a model species. PMID:25088042

Popovic, Marta; Zaja, Roko; Fent, Karl; Smital, Tvrtko

2014-10-01

98

A Reduced Complexity Quasi-1D Viterbi Detector  

Directory of Open Access Journals (Sweden)

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

Rabi N. Panda

2011-02-01

99

A Reduced Complexity Quasi-1D Viterbi Detector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

100

Spectral decomposition of 1D Fokker - Planck differential operator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We construct spectral decomposition of 1D Fokker - Planck differential operator. This reveal solution of Cauchy problem. We develop fundamental solution of Cauchy problem and compare it with one obtained by other means in our former work [5].

Tanski, Igor A.

2006-01-01

 
 
 
 
101

1D photonic crystal sensor integrated in a microfluidic system  

DEFF Research Database (Denmark)

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

Nunes, Pedro; Mortensen, Asger

2009-01-01

102

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

103

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

104

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)

105

On the computation of long period seismograms in a 3-D earth using normal mode based approximations  

Science.gov (United States)

Tomographic inversions for large-scale structure of the earth's mantle involve a forward modelling step of wave propagation through 3-D heterogeneity. Until now, most investigators have worked in the framework of the simplest theoretical assumptions, namely the infinite frequency `ray theory' in the case of body wave traveltime inversions, or the `path-average' approximation (PAVA) to normal mode perturbation theory, in the case of surface waves and long-period waveforms. As interest is shifting to mapping shorter wavelength structures, the need for a more accurate theoretical account of the interaction of seismic waves with mantle heterogeneity, coupled with improvements in path coverage, has been realized. Here we discuss different levels of approximations used in the context of normal mode perturbation theory, when modelling time domain seismic waveforms. We compare the performance of asymptotic approximations, which collapse the effects of 3-D structure onto the great circle vertical plane: the 1-D PAVA and a 2-D approximation called non-linear asymptotic coupling theory (NACT), which both are zeroth order asymptotic approximations. We then discuss how off-vertical plane effects can be introduced using higher order asymptotics. These computationally efficient approximations are compared to the linear Born formalism (BORN), which computes scattering integrals over the entire surface of the sphere. We point out some limitations of this linear formalism in the case of spatially extended anomalies, and show how that can be remedied through the introduction of a non-linear term (NBORN). All these approximations are referenced to a precise 3-D numerical computation afforded by the spectral element method. We discuss simple geometries, and explore a range of sizes of anomalies compared to the wavelength of the seismic waves considered, thus illustrating the range of validity and limitations of the various approximations considered.

Romanowicz, Barbara A.; Panning, Mark P.; Gung, Yuancheng; Capdeville, Yann

2008-11-01

106

1D EM Modeling for Onshore Hydrocarbon Detection using MATLAB  

Directory of Open Access Journals (Sweden)

Full Text Available Controlled Source Electromagnetic (CSEM is a new technique used for hydrocarbons detection. This study focuses on One dimension (1D modeling of hydrocarbon detection for onshore application using the principles of electromagnetic (EM waves propagation. The transmitted frequency which is 0.25 Hz was used to characterize the hydrocarbon at 500 m, 1000 m and 1500 m. Electric fields detected by the receivers at 500, 1000 and 1500 m were 22.85, 20.4 and 17.1 V m-1, respectively which was determined by using 1D simulation. This non-seismic 1D modeling may provide alternative solution for hydrocarbon (HC detection for oil and gas industry.

N.H.H.M. Hanif

2011-01-01

107

Decoupled 1D/3D analysis of a hydraulic valve  

Science.gov (United States)

Analysis approaches during product development of fluid valves and other aircraft fluid delivery components vary greatly depending on the development stage. Traditionally, empirical or simplistic one-dimensional tools are being deployed during preliminary design, whereas detailed analysis such as CFD (Computational Fluid Dynamics) tools are used to refine a selected design during the detailed design stage. In recent years, combined 1D/3D co-simulation has been deployed specifically for system level simulations requiring an increased level of analysis detail for one or more components. The present paper presents a decoupled 1D/3D analysis approach where 3D CFD analysis results are utilized to enhance the fidelity of a dynamic 1D modelin context of an aircraft fuel valve.

Mehring, Carsten; Zopeya, Ashok; Latham, Matt; Ihde, Thomas; Massie, Dan

2014-10-01

108

Time-Resolved 1-D X-ray Imaging Technique for Z-Pinch Plasma Diagnosis  

International Nuclear Information System (INIS)

A sensitive time-resolved 1-D x-ray imaging system with linear energy response to 100eV-2keV x-rays is developed and applied in Z-Pinch experiments to investigate time dependent x-ray distribution with one-dimensional(1-D) spatial resolution of 0.1mm?0.4mm and temporal resolution of 3ns. A slit in the system relays the 1-D image of the pinch plasma to a plastic scintillator foil with a thickness of 0.2mm which converts x-ray to visible and near-infrared light and has linear response to x-ray energy. With an optical fiber array consisting of 40 linearly arranged individual fibers behind the scintillator foil, it is capable of transmitting the 1-D image out from within the vacuum chamber. The optical fiber array is subsequently coupled to a streak camera via optical fiber bundle consisting of 40 individual 30-meter-long fibers to allow the investigation of time-resolved 1D x-ray distribution. To avoid viewing the plasma-generated visible light and covering aluminum foil on the scintillator, both the scintillator foil and the fiber array are tilted at an angle of 45 degrees from the line of sight. This diagnostic system has been successfully applied in gas-puff and tungsten wire-array Z-Pinch experiments carried out on Qiang-Guang-1, S-300, and Angara-5-1 facilities for time-resolved measurement of x-ray power distribution along the axis or radius of the imploding plasma. In these experiments, the current is in the range of 1-3MA and the x-ray radiation energy is in th and the x-ray radiation energy is in the order of 10-50kJ. Some experimental results will be presented in this paper

109

Effect of the twist operator in the D1D5 CFT  

CERN Document Server

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

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

2014-01-01

110

Effect of the twist operator in the D1D5 CFT  

Science.gov (United States)

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

Carson, Zaq; Hampton, Shaun; Mathur, Samir D.; Turton, David

2014-08-01

111

Evaluation of confinement capability of radioactive materials under the fire accident in nuclear fuel facility with CELVA-1D (Cell Ventillation Analysis Code-1D)  

International Nuclear Information System (INIS)

To reduce the clogging of smoke on the HEPA filters under the fire accident, some of ventilation systems in the plant are equipped with the pre-filters in front of the HEPA filters for collecting the relatively large smoke particles. Appropriate correspondence such as the exchange of the pre-filter is important for confinement of radioactive materials in the ventilation system under the fire accident. To study smoke generation behavior due to the burnable wastes and clogging properties of the ventilation filters by smoke loading, the verification test has been performed. The cell ventilation system analysis code, CELVA-1D was used for analysis of smoke generation and the rising of pressure drop at both the pre-filter and the HEPA filter. With the change of source term, the breakage of time of the pre-filter was also estimated. (author)

112

Interior gradient estimate for 1-D anisotropic curvature flow  

Directory of Open Access Journals (Sweden)

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

Yoshihiro Tonegawa

2005-11-01

113

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

114

T1D in College (Type 1 Diabetes)  

Science.gov (United States)

... Kids Walk to Cure Diabetes Young Leadership Committee Corporate Partners Related Countdown Stories Volunteer Spotlight: Martin Gilmore ... with T1D means more freedom along with increased responsibility. Gain insights and information to ... you’re facing. Type One Nation , JDRF’s social network for people with type 1 diabetes is ...

115

Observation of the Upsilon(1D) and Upsilon(2D)  

CERN Document Server

We present evidence, from published BABAR data, for the existence of further excitations in the b-bbar spectrum, namely the long-awaited Upsilon(1D) and Upsilon(2D) with central masses of 10098 pm 5 MeV and 10492 pm 5 MeV, respectively.

van Beveren, Eef

2010-01-01

116

Polaron in a quasi 1D cylindrical quantum wire  

Directory of Open Access Journals (Sweden)

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

I.Nsangou

2005-01-01

117

Large Time existence For 1D Green-Naghdi equations  

CERN Document Server

We consider here the $1D $ Green-Naghdi equations that are commonly used in coastal oceanography to describe the propagation of large amplitude surface waves. We show that the solution of the Green-Naghdi equations can be constructed by a standard Picard iterative scheme so that there is no loss of regularity of the solution with respect to the initial condition.

Israwi, Samer

2009-01-01

118

Two-phase 1D+1D model of a DMFC: development and validation on extensive operating conditions range  

Energy Technology Data Exchange (ETDEWEB)

A two-phase 1D+1D model of a direct methanol fuel cell (DMFC) is developed, considering overall mass balance, methanol transport in gas phase through anode diffusion layer, methanol and water crossover. The model is quantitatively validated on an extensive range of operating conditions, 24 polarisation curves. The model accurately reproduces DMFC performance in the validation range and, outside this, it is able to predict values under feasible operating conditions. Finally, the estimations of methanol crossover flux are qualitatively and quantitatively similar to experimental measures and the main local quantities' trends are coherent with results obtained with more complex models. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Casalegno, A.; Marchesi, R.; Parenti, D. [Dipartimento di Energetica, Politecnico di Milano (Italy)

2008-02-15

119

1D design style implications for mask making and CEBL  

Science.gov (United States)

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

Smayling, Michael C.

2013-09-01

120

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

Science.gov (United States)

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

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

2014-04-01

 
 
 
 
121

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

Science.gov (United States)

Surface plasmon-polariton (SPP) excitations of metal-dielectric interfaces are a fundamental light-matter interaction which has attracted interest as a route to spatial confinement of light far beyond that offered by conventional dielectric optical devices. Conventionally, SPPs have been studied in noble-metal structures, where the SPPs are intrinsically bound to a 2D metal-dielectric interface. Meanwhile, recent advances in the growth of hybrid 2D crystals, which comprise laterally connected domains of distinct atomically thin materials, provide the first realistic platform on which a 2D metal-dielectric system with a truly 1D metal-dielectric interface can be achieved. Here we show for the first time that 1D metal-dielectric interfaces support a fundamental 1D plasmonic mode (1DSPP) which exhibits cutoff behavior that provides dramatically improved light confinement in 2D systems. The 1DSPP constitutes a new basic category of plasmon as the missing 1D member of the plasmon family: 3D bulk plasmon, 2DSPP, 1DSPP, and 0D localized SP. PMID:24686894

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

2014-01-01

122

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

123

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

124

Excitations in the deformed D1D5 CFT  

CERN Document Server

We perform some simple computations for the first order deformation of the D1D5 CFT off its orbifold point. It had been shown earlier that under this deformation the vacuum state changes to a squeezed state (with the further action of a supercharge). We now start with states containing one or two initial quanta and write down the corresponding states obtained under the action of deformation operator. The result is relevant to the evolution of an initial excitation in the CFT dual to the near extremal D1D5 black hole: when a left and a right moving excitation collide in the CFT, the deformation operator spreads their energy over a larger number of quanta, thus evolving the state towards the infrared.

Avery, Steven G; Mathur, Samir D

2010-01-01

125

Sandia reactor kinetics codes: SAK and PK1D  

International Nuclear Information System (INIS)

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

126

Universal quantum walks and adiabatic algorithms by 1D Hamiltonians  

CERN Document Server

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

Chase, Bradley A

2008-01-01

127

Developing 1D nanostructure arrays for future nanophotonics  

Directory of Open Access Journals (Sweden)

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

Cooke DG

2006-01-01

128

Noise correlations in 1D Bose mixtures in optical lattices  

Science.gov (United States)

We study the noise correlations of one-dimensional(1D) Bose mixtures, as a probe of their quantum phases. In [1], we discuss the rich structure of many-body phases, such as paired and counterflow superfluidity in such 1D mixtures. We now ask the question what is the signature of these phases in the correlations of the atomic cloud after time-of- flight at long times. Using both Luttinger liquid theory and time-evolving block decimation (TEBD) method, we find clear signatures of these phases. Within the numerical approach we also discuss the case of trapped systems.[4pt] [1] Anzi Hu, L. Mathey, Ippei Danshita, Eite Tiesinga, Carl J. Williams, and Charles W. Clark, Phys. Rev. A 80, 023619 (2009).

Hu, Anzi; Mathey, Ludwig; Williams, Carl; Clark, Charles

2010-03-01

129

D1D5 system and noncommutative geometry  

International Nuclear Information System (INIS)

Supergravity on AdS3xS3xT4 has a dual description as a conformal sigma-model with the target space being the moduli space of instantons on the noncommutative torus. We derive the precise relation between the parameters of this noncommutative torus and the parameters of the near-horizon geometry. We show that the low energy dynamics of the system of D1D5-branes wrapped on the torus of finite size is described in terms of the noncommutative geometry. As a byproduct, we give a prediction on the dependence of the moduli space of instantons on the noncommutative T4 on the metric and the noncommutativity parameter. We give a compelling evidence that the moduli space of stringy instantons on R4 with the B-field does not receive ?'-corrections. We also study the relation between the D1D5 sigma-model instantons and the supergravity instantons

130

Developing 1D nanostructure arrays for future nanophotonics  

Science.gov (United States)

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

Polanyi, John C; Yang, JodySY; Wu, Zhanghua; Philipose, Usha; Xu, Tao; Yang, Susan; Kavanagh, KL; Liu, JQ; Yang, L; Wang, Y; Robbie, Kevin; Yang, J; Kaminska, K; Cooke, DG; Hegmann, FA; Budz, AJ; Haugen, HK

2006-01-01

131

Quantitative 1D saturation profiles on chalk by NMR.  

DEFF Research Database (Denmark)

Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal that strong saturation gradients exist in chalk core samples after core floods, due to capillary effects. The method is useful in analysis of corefloods, e.g., for determination of capillary pressure functions

Olsen, Dan; Topp, Simon

1996-01-01

132

Benchmarking 1D Hydrodynamic Codes for Steady State Solutions  

Science.gov (United States)

Recent studies that investigate the coronal heating problem use numerical codes to solve the 1D hydrodynamic equations. Many different numerical solutions are involved for solving the equations, however, only a few comparison have been made between the different numerical results. In this study, we begin a benchmarking process by comparing steady state solutions from the NRL Solar Flux Tube Model(SOLFTM), AAD's code and Serio's Scaling Law by calculating percentage differences in their simulated temperatures and densities.

Mulu-Moore, F.; Winebarger, A.; Warren, H.

2007-12-01

133

Phonons and Solitons in 1D Mott Insulators  

CERN Document Server

We study the problem of one-dimensional (1D) Luttinger liquids in the insulating Mott-Hubbard phase in the presence of acoustic phonons in the semiclassical limit. We show that solitonic excitations can propagate freely in the system and the energy required to produce a soliton is reduced by a polaronic effect. We find a critical value of the electron-phonon coupling constant for which this energy vanishes.

Chang, C M; Bishop, A R; Chang, Chun-Min

2000-01-01

134

Ultrahigh-Q nanocavity with 1D photonic gap.  

Science.gov (United States)

Recently, various wavelength-sized cavities with theoretical Q values of approximately 10(8) have been reported, however, they all employ 2D or 3D photonic band gaps to realize strong light confinement. Here we numerically demonstrate that ultrahigh-Q (2.0x10(8)) and wavelength-sized (V(eff) approximately 1.4(lambda/n)3) cavities can be achieved by employing only 1D periodicity. PMID:18648423

Notomi, M; Kuramochi, E; Taniyama, H

2008-07-21

135

1-D DCT Using Latency Efficient Floating Point Algorithms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents the design of one-dimensional discrete cosine transform (DCT) architecture for digital signal processing (DSP) applications. DCT is a basic transformation for coding method which converts spatial domain to frequency domain of image. In 1-D DCT operation addition, subtraction, multiplication operations are required. These operations must be accurate, less latency. Floating point operations have dynamic range of representation, more accurate and perform millions of calculati...

Viswanath Gowd A, Yedukondala Rao V.

2013-01-01

136

Regimes of quantum degeneracy in trapped 1D gases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We discuss the regimes of quantum degeneracy in a trapped 1D gas and obtain the diagram of states. Three regimes have been identified: the BEC regimes of a true condensate and quasicondensate, and the regime of a trapped gas of Tonks (gas of impenetrable bosons). The presence of a sharp cross-over to the BEC regime requires extremely small interaction between particles. We discuss how to distinguish between true and quasicondensates in phase coherence experiments.

Petrov, D. S.; Shlyapnikov, G. V.; Walraven, J. T. M.

2000-01-01

137

Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer  

Science.gov (United States)

Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication1. Here, using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focussed on protein truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, we show that rare PTVs in the p53 inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and to ovarian cancer. PPM1D PTV mutations were present in 25/7781 cases vs 1/5861 controls; P=1.12×10?5, which included 18 mutations in 6,912 individuals with breast cancer; P = 2.42×10?4 and 12 mutations in 1,121 individuals with ovarian cancer; P = 3.10×10?9. Notably, all the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370 bp region in the final exon of the gene, C-terminal to the phosphatase catalytic domain. Functional studies demonstrated that the mutations result in enhanced suppression of p53 in response to ionising radiation exposure, suggesting the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function typically associated with this class of variant, but instead likely have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the utility of sequencing in their identification. PMID:23242139

Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A.; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Pour, Naser Ansari; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M.; Yang, Tsun-Po; Adlard, Julian W.; Barwell, Julian; Berg, Jonathan; Brady, Angela F.; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D. Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J.; Paterson, Joan; Porteous, Mary; Rogers, Mark T.; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A.; Caufield, Mark J.; Deloukas, Panagiotis; McCarthy, Mark I.; Todd, John A.; Turnbull, Clare; Reis-Filho, Jorge S.; Ashworth, Alan; Antoniou, Antonis C.; Lord, Christopher J.; Donnelly, Peter; Rahman, Nazneen

2013-01-01

138

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)

139

Enhancing Solar Cell Efficiencies through 1-D Nanostructures  

Directory of Open Access Journals (Sweden)

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

Yu Kehan

2008-01-01

140

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)

 
 
 
 
141

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

International Nuclear Information System (INIS)

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

142

Controllable Photonic Band Gap and Defect Mode in a 1D CO2-Laser Optical Lattice  

International Nuclear Information System (INIS)

We propose a new method to form a novel controllable photonic crystal with cold atoms and study the photonic band gap (PBG) of an infinite 1D CO2-laser optical lattice of 85Rb atoms under the condition of quantum coherence. A significant gap generated near the resonant frequency of the atom is founded and its dependence on physical parameters is also discussed. Using the eigenquation of defect mode, we calculate the defect mode when a defect is introduced into such a lattice. Our study shows that the proposed new method can be used to optically probe optical lattice in situ and to design some novel and controllable photonic crystals

143

Construction of two 3D homochiral frameworks with 1D chiral pores via chiral recognition.  

Science.gov (United States)

The reactions of a pair of enantiomers of macrocyclic nickel(II) complexes with racemic penicillamine generated two 3D hydrogen-bonded homochiral frameworks of {[Ni(f-(SS)-L)](2)(l-pends)(ClO(4))(2)}(n) (?-1) and {[Ni(f-(RR)-L)](2)(d-pends) (ClO(4))(2)}(n) (?-1). The frameworks possess 1D tubular pores and opposite right/left-handed helical porous surfaces (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane; pends(2-) = penicillaminedisulfide anion). PMID:21434680

Li, Huan-Yong; Jiang, Long; Xiang, Hua; Makal, Trevor A; Zhou, Hong-Cai; Lu, Tong-Bu

2011-04-18

144

The Effect of a Shallow Thrust-Fault Reflecting Boundary Condition on Teleseismic Radiated Energy: Study Using Dynamic Finite-Element Rupture Models and Synthetic Body Wave Seismograms  

Science.gov (United States)

It has been suggested that dislocation models of teleseismic waves may seriously underestimate seismic moments of shallow thrust-fault events (Brune, 1996). Dislocation models allow seismic waves, such as reflected phases, to propagate through the fault boundary unimpeded, i.e., they are "transparent" to seismic radiation. Brune hypothesizes instead that the two sides of the fault separate during rupture creating a reflecting boundary condition that is "opaque" to seismic radiation. If so, then energy becomes trapped in the overhanging wedge, radiated energy to teleseismic distances is reduced, and the moment is underestimated. We tested this by producing and comparing synthetic P and SH seismograms for earthquakes with and without a reflecting or "opaque" fault boundary condition. We used friction laws in dynamic, three-dimensional finite-element models to create slip-histories for models with partially to completely reflecting faults in the Mode II and Mode III directions. The inclusion of gravity created sufficient lithostatic stress that any Mode I opening was negligible. We have three "opaque" models in order of most to least opaque: crack-like (slip-weakening) with zero sliding friction, crack-like with constant sliding friction, and pulse-like (slip- and rate-weakening). The slip-history of our dislocation model with a "transparent" fault boundary condition (Haskell-like model), is the integral of Brune's (1970) far-field time function. Slip-histories for these "opaque" and "transparent" models are normalized such that they have the same potency. In addition, the Haskell-like model slip-history is designed to have the same final slip, peak slip-rate, and slip start times as the pulse-like model at each location on the fault for a close comparison. Synthetic seismograms were calculated for the above four models at a variety of azimuths and epicentral distances, and the peak-to-peak amplitudes were numerically evaluated. Note that we normalized the peak-to-peak amplitudes of the three "opaque" models by the Haskell-like model. Therefore, a peak-to-peak value 1 indicates that dislocation theory would overestimate the seismic moment of the opaque model. Our results for the P wave peak-to-peak amplitudes are: 1.64 for crack-like with zero sliding friction, 0.96 for crack-like with constant sliding friction, and 1.09 for pulse-like. For SH waves the values are: 2.02 for crack-like with zero sliding friction, 1.02 for crack-like with constant sliding friction, and 1.05 for pulse-like. Interestingly, two out of the three models (constant sliding friction and pulse-like) have peak-to-peak amplitudes either very close or slightly larger than the "transparent," Haskell-like model. The somewhat unrealistic, zero sliding friction model (which is "opaque" to all Mode II and Mode III sliding) has a larger peak-to-peak amplitude than the Haskell-like, but this can be explained by the fact it oscillates about the equilibrium, zero frequency solution. Thus, it appears that a reflecting boundary condition has little to no effect on the radiated energy to teleseismic distances. If anything, a completely reflecting boundary increases the radiated energy. Hence, we do not find any problem with standard dislocation theory in estimating seismic moment.

Smith, D. E.; Aagaard, B. T.; Heaton, T. H.

2002-12-01

145

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

146

Molecular characterization of zebrafish Oatp1d1 (Slco1d1), a novel organic anion-transporting polypeptide.  

Science.gov (United States)

The organic anion-transporting polypeptide (OATP/Oatp) superfamily includes a group of polyspecific transporters that mediate transport of large amphipathic, mostly anionic molecules across cell membranes of eukaryotes. OATPs/Oatps are involved in the disposition and elimination of numerous physiological and foreign compounds. However, in non-mammalian species, the functional properties of Oatps remain unknown. We aimed to elucidate the role of Oatp1d1 in zebrafish to gain insights into the functional and structural evolution of the OATP1/Oatp1 superfamily. We show that diversification of the OATP1/Oatp1 family occurs after the emergence of jawed fish and that the OATP1A/Oatp1a and OATP1B/Oatp1b subfamilies appeared at the root of tetrapods. The Oatp1d subfamily emerged in teleosts and is absent in tetrapods. The zebrafish Oatp1d1 is similar to mammalian OATP1A/Oatp1a and OATP1B/Oatp1b members, with the main physiological role in transport and balance of steroid hormones. Oatp1d1 activity is dependent upon pH gradient, which could indicate bicarbonate exchange as a mode of transport. Our analysis of evolutionary conservation and structural properties revealed that (i) His-79 in intracellular loop 3 is conserved within OATP1/Oatp1 family and is crucial for the transport activity; (ii) N-glycosylation impacts membrane targeting and is conserved within the OATP1/Oatp1 family with Asn-122, Asn-133, Asn-499, and Asn-512 residues involved; (iii) the evolutionarily conserved cholesterol recognition interaction amino acid consensus motif is important for membrane localization; and (iv) Oatp1d1 is present in dimeric and possibly oligomeric form in the cell membrane. In conclusion, we describe the first detailed characterization of a new Oatp transporter in zebrafish, offering important insights into the functional evolution of the OATP1/Oatp1 family and the physiological role of Oatp1d1. PMID:24126916

Popovic, Marta; Zaja, Roko; Fent, Karl; Smital, Tvrtko

2013-11-22

147

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-07-01

148

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)

149

BGK electron solitary waves: 1D and 3D  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents new results for 1D BGK electron solitary wave (phase-space electron hole solutions and, based on the new results, extends the solutions to include the 3D electrical interaction (E ~ 1/r 2 of charged particles. Our approach for extending to 3D is to solve the nonlinear 3D Poisson and 1D Vlasov equations based on a key feature of 1D electron hole (EH solutions; the positive core of an EH is screened by electrons trapped inside the potential energy trough. This feature has not been considered in previous studies. We illustrate this key feature using an analytical model and argue that the feature is independent of any specific model. We then construct azimuthally symmetric EH solutions under conditions where electrons are highly field-aligned and ions form a uniform background along the magnetic field. Our results indicate that, for a single humped electric potential, the parallel cut of the perpendicular component of the electric field (E? is unipolar and that of the parallel component (E|| bipolar, reproducing the multi-dimensional features of the solitary waves observed by the FAST satellite. Our analytical solutions presented in this article capture the 3D electric interaction and the observed features of (E|| and E?. The solutions predict a dependence of the parallel width-amplitude relation on the perpendicular size of EHs. This dependence can be used in conjunction with experimental data to yield an estimate of the typical perpendicular size of observed EHs; this provides important information on the perpendicular span of the source region as well as on how much electrostatic energy is transported by the solitary waves.

L.-J. Chen

2002-01-01

150

RMXXST057001 4-1(+d2) [RefDIC  

Full Text Available RMXXST057001 Sample ID: RMXXST057001 Source Treatment RNA Quality Check Labeling Hybridization R ... aw Data Reference Sample - Source Sample Title 4 -1(+d2) Organism Mus musculus Source Type cell line ... pe stem cell Cell Purification n/a Growth Protocol 4 -1(ZHBTc4 )ES cells were cultured for 2 days in the ... addition of tetracycline, the expression of Oct-3/4 ... is completely disappeared in 4 -1(ZHBTc4 )ES cells. ... addition of tetracycline, the expression of Oct-3/4 ... is completely disappeared in 4 -1(ZHBTc4 )ES cells. ...

151

RMXXST056001 4-1(+d1) [RefDIC  

Full Text Available RMXXST056001 Sample ID: RMXXST056001 Source Treatment RNA Quality Check Labeling Hybridization R ... aw Data Reference Sample - Source Sample Title 4 -1(+d1) Organism Mus musculus Source Type cell line ... pe stem cell Cell Purification n/a Growth Protocol 4 -1(ZHBTc4 )ES cells were cultured for 1 day in the p ... addition of tetracycline, the expression of Oct-3/4 ... is completely disappeared in 4 -1(ZHBTc4 )ES cells. ... addition of tetracycline, the expression of Oct-3/4 ... is completely disappeared in 4 -1(ZHBTc4 )ES cells. ...

152

Cluster size distribution in 1D-CA traffic models  

International Nuclear Information System (INIS)

We propose a useful method to analyze one-dimensional (1D)-cellular automata traffic models based on the distribution of cluster size in the system. By applying this method, we reproduce the exact solution of the totally asymmetric exclusion process and the zero range process (ZRP). Moreover, we confirm that a certain kind of slow-to-start model can be interpreted as the ZRP and also obtain the exact solution of it. Finally, we extend the Fukui–Ishibashi model and obtain promising expressions of the flux. (paper)

153

Nanofluidic sustainable energy conversion using a 1D nanofluidic network.  

Science.gov (United States)

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

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

2014-05-01

154

Phase transition in (2+1)d quantum gravity  

CERN Document Server

(2+1) dimensional gravity is equivalent to an exactly soluble non-Abelian Chern-Simons gauge field theory (E Witten 1988). Regarding this as the topological phase of quantum gravity in (2+1)d, we suggest a topological symmetry breaking by introducing a mass term for the gauge fields, which carries a space-time metric and local dynamical degrees of freedom. We consider the finite temperature behavior of the symmetry broken phase, and claim a restoration of the topological invariance at some critical temperature. The phase transition is shown of the zeroth order.

Chen, W

1994-01-01

155

D1-D5 black hole microstate counting from supergravity  

CERN Document Server

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

Rychkov, V S

2006-01-01

156

PLZT spatial light modulator for a 1-D hologram memory.  

Science.gov (United States)

A 100-bit slitlike aperture array spatial light modulator has been developed using 8.8/65/35 PLZT for a high-bit-density 1-D hologram memory. The most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized. The lowest SNR was 86, and rise time and fall time have been 30 microsec and 8 microsec, respectively, at 190-V halfwave voltage. One-dimensional holographic storage experiments have been successfully performed using this PLZT spatial light modulator. PMID:20216813

Ueno, K; Saku, T

1980-01-01

157

Spatial coherence of polaritons in a 1D channel  

International Nuclear Information System (INIS)

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

158

1-D DCT Using Latency Efficient Floating Point Algorithms  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the design of one-dimensional discrete cosine transform (DCT architecture for digital signal processing (DSP applications. DCT is a basic transformation for coding method which converts spatial domain to frequency domain of image. In 1-D DCT operation addition, subtraction, multiplication operations are required. These operations must be accurate, less latency. Floating point operations have dynamic range of representation, more accurate and perform millions of calculations per second. So the floating point operations are used for the above operations. In this floating point adder/subtractor is the most complex operation in a floating-point arithmetic and consists of many variable latency- and area dependent sub-operations. In floating-point addition implementations, latency is the primary performance bottleneck. So different types of floating point adder/subtractor algorithms such as LOD, LOP, Two-path are used to decrease the latency. The trade off is observed in 1-D DCT by changing different types of adders in place of summer. All architectures are designed and implemented using VHDL using Xillinx 13.1software.

Viswanath Gowd A, Yedukondala Rao V, T. Shanmuganantham

2013-04-01

159

A Diamagnetic Trap with 1D Camelback Potential  

CERN Document Server

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

Gunawan, Oki

2014-01-01

160

Polarization transitions in interacting ring 1D arrays  

CERN Document Server

Periodic nanostructures can display the dynamics of arrays of atoms while enabling the tuning of interactions in ways not normally possible in Nature. We examine one dimensional arrays of a ``synthetic atom,'' a one dimensional ring with a nearest neighbor Coulomb interaction. We consider the classical limit first, finding that the singly charged rings possess antiferroelectric order at low temperatures when the charge is discrete, but that they do not order when the charge is treated as a continuous classical fluid. In the quantum limit Monte Carlo simulation suggests that the system undergoes a quantum phase transition as the interaction strength is increased. This is supported by mapping the system to the 1D transverse field Ising model. Finally we examine the effect of magnetic fields. We find that a magnetic field can alter the electrostatic phase transition producing a ferroelectric groundstate, solely through its effect of shifting the eigenenergies of the quantum problem.

Roostaei, B; Mullen, Kieran; Roostaei, Bahman

2006-01-01

 
 
 
 
161

Two new 1D coordination polymers: syntheses, structures and properties  

Directory of Open Access Journals (Sweden)

Full Text Available Two new coordination polymers, namely, [Zn(bi(Cl2]n (1 and [Cu(L2(bib(H2O2]n (2 (bi = 4,4'-bis(2-methylimidazol-1-ylmethylbiphenyl; L = 4-(2-(4-(methoxycarbonylphenoxyethoxybenzoic acid and bib = 2,3-bis(4-pyridylbutane, are synthesized and characterized. Both of 1 and 2 have 1D covalent chains, which show different conformally chain feature. 2D supremolecular rhombic and rectangle motifs are observed in 1 and 2, respectively. The O–H···O and C–H···Cl hydrogen-bonding interactions play a significant role in promoting the diversity of structural patterns. DOI: http://dx.doi.org/10.4314/bcse.v28i3.11

J. Wu

2014-09-01

162

D1D5 System and Noncommutative Geometry  

CERN Document Server

Supergravity on $AdS_3\\times S^3\\times {\\bf T}^4$ has dual description as a conformal sigma-model with the target space the moduli space of instantons on the noncommutative torus. We derive the precise relation between the parameters of this noncommutative torus and the parameters of the near-horizon geometry. We show that the low energy dynamics of the system of $D1D5$ branes wrapped on the torus of finite size is described in terms of noncommutative geometry. As a byproduct, we give a prediction on the dependence of the moduli space of instantons on the noncommutative ${\\bf T}^4$ on the metric and the noncommutativity parameter. We give a compelling evidence that the moduli space of stringy instantons on ${\\bf R}^4$ with the $B$ field does not receive sigma-model instantons and the supergravity instantons.

Mikhailov, A

2000-01-01

163

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.

Mátéfi-Tempfli, Stefan

2003-01-01

164

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.)

165

Pseudo-fermionization of 1-D bosons in optical lattices  

CERN Document Server

We present a model that generalizes the Bose-Fermi mapping for strongly correlated 1D bosons in an optical lattice, to cases in which the average number of atoms per site is larger than one. This model gives an accurate account of equilibrium properties of such systems, in parameter regimes relevant to current experiments. The application of this model to non-equilibrium phenomena is explored by a study of the dynamics of an atom cloud subject to a sudden displacement of the confining potential. Good agreement is found with results of recent experiments. The simplicity and intuitive appeal of this model make it attractive as a general tool for understanding bosonic systems in the strongly correlated regime.

Pupillo, G; Williams, C J; Clark, C W; Pupillo, Guido; Rey, Ana Maria; Williams, Carl J.; Clark, Charles W.

2005-01-01

166

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

167

Ballistic Localization in Quasi-1D Waveguides with Rough Surfaces  

CERN Document Server

Structure of eigenstates in a periodic quasi-1D waveguide with a rough surface is studied both analytically and numerically. We have found a large number of "regular" eigenstates for any high energy. They result in a very slow convergence to the classical limit in which the eigenstates are expected to be completely ergodic. As a consequence, localization properties of eigenstates originated from unperturbed transverse channels with low indexes, are strongly localized (delocalized) in the momentum (coordinate) representation. These eigenstates were found to have a quite unexpeted form that manifests a kind of "repulsion" from the rough surface. Our results indicate that standard statistical approaches for ballistic localization in such waveguides seem to be unappropriate.

Izrailev, F M; Luna-Acosta, G A

2003-01-01

168

Slab detachment - 3-D versus 1-D & 2-D  

Science.gov (United States)

Slab detachment is a geodynamic process that may affect subduction zones on Earth. This process is characterized by the detachment of a subducting slab fragment and results in a dramatic decrease of the slab pull force magnitude. As a result, slab detachment has many potential consequences for the dynamics of convergent zones such as orogens. We study three-dimensional (3-D) lateral propagation of slab detachment due to a laterally varying initial slab length with numerical simulations based on the finite element method (FEM). The slab detachment is simulatedby buoyancy-driven necking in a layer of power-law fluid embedded in a linear viscous medium. Our 3-D FEM code combines a numerical contour-line technique and a deformable Lagrangian mesh with re-meshing. With this combined method it is possible to accurately follow the initial material contours with the FEM mesh and to accurately resolve the geometrical instabilities. We are able to follow the material contour and therefore, to study the accurate slab geometry at any time. We provide a detailed description of the evolution of the slab morphology and evaluate the rates of lateral propagation of slab detachment.We compare the 3D results with the 1-D analytical solution for slab detachment of Schmalholz (2011). We further compare the 3-D results with 2-D numerical simulationsthat can be described reasonably well with the 1-D analytical solution. The fundamental differences between the3-D and 2-D slab detachment are identified and quantified. REFERENCES Schmalholz, S., 2011, A simple analytical solution for slab detachment, Earth and Planetary Science Letters 304, 45-54

von Tscharner, Marina; Duretz, Thibault; Schmalholz, Stefan

2014-05-01

169

A 1-D model for highly sensitive tubular reactors  

Energy Technology Data Exchange (ETDEWEB)

We consider the steady state operation of wall-cooled, fixed-bed tubular reactors. In these reactors the temperature rise ..delta..T must normally be limited to small fractions of the adiabatic temperature rise ..delta..T/sub ad/, both to avoid runaway and maintain product selectivity. Yet ..delta..T/..delta..T/sub ad/ << 1 can only occur if eta = t/sub dif//t/sub reac/ << 1, where t/sub dif/ is the timescale on which heat escapes the reactor by ''diffusing'' to the cooled walls, and t/sub reac/ is the timescale over which the reaction occurs. So here we use asymptotic methods based on eta << 1 to analyze the 2-d reactor equations, and find the radial concentration and temperature profiles to leading order in eta. We then obtain a 1-d model of the reactor by substituting these asymptotically correct profiles into the reactor equations and averaging over r. This model, the ..cap alpha..-model, is identical to the standard (Beek and Singer) 1-d model, except that the reactor's overall heat transfer coefficient U is a decreasing function of the temperature rise ..delta..T. This occurs because as ..delta..T increases, the reaction becomes increasingly concentrated near r = 0, causing a decreased heat transfer efficiency through the reactor's walls. By comparing it with numerical solutions of the original 2-d reactor equations, we find that the ..cap alpha..-model simulates the 2-d equations very accurately, even for highly sensitive reactors operated near runaway. We also find that a runaway criterion derived from the ..cap alpha..-model predicts the runaway transition of the original 2-d equations accurately, especially for highly sensitive reactors. 19 refs.

Hagan, P.S.; Herskowitz, M.; Pirkle, J.C.

1987-01-01

170

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

171

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

CERN Document Server

A 1D code modelling 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 or radially.

Havlickova, E; Subba, F; Coster, D; Wischmeier, M; Fishpool, G

2013-01-01

172

Spin asymmetry A1d and the spin-dependent structure function g1d of the deuteron at low values of x and Q2  

Science.gov (United States)

We present a precise measurement of the deuteron longitudinal spin asymmetry A1d and of the deuteron spin-dependent structure function g1d at Q2 < 1 (GeV / c) 2 and 4 ×10-5 < x < 2.5 ×10-2 based on the data collected by the COMPASS experiment at CERN during the years 2002 and 2003. The statistical precision is tenfold better than that of the previous measurement in this region. The measured A1d and g1d are found to be consistent with zero in the whole range of x.

Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Bade?ek, B.; Balestra, F.; Ball, J.; Baum, G.; Bedfer, Y.; Bernet, C.; Bertini, R.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M. P.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Costa, S.; Crespo, M. L.; D'Hose, N.; Dalla Torre, S.; Dasgupta, S. S.; de Masi, R.; Denisov, O. Yu.; Dhara, L.; Diaz Kavka, V.; Dinkelbach, A. M.; Donskov, S. V.; Dorofeev, V. A.; Doshita, N.; Duic, V.; Dünnweber, W.; Eversheim, P. D.; Eyrich, W.; Fabro, M.; Faessler, M.; Falaleev, V.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M.; Fischer, H.; Franz, J.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A. M.; Grajek, O. A.; Grasso, A.; Grube, B.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Hedicke, S.; Heinsius, F. H.; Hermann, R.; Heß, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Ilgner, C.; Ioukaev, A. I.; Ishimoto, S.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N. I.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Khomutov, N. V.; Kisselev, Yu.; Klein, F.; Koblitz, S.; Koivuniemi, J. H.; Kolosov, V. N.; Komissarov, E. V.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Korentchenko, A. S.; Korzenev, A.; Kotzinian, A. M.; Koutchinski, N. A.; Kravchuk, N. P.; Kroumchtein, Z. V.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M. E.; Lamanna, M.; Le Goff, J. M.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matsuda, T.; Maximov, A. N.; Meyer, W.; Mielech, A.; Mikhailov, Yu. V.; Moinester, M. A.; Nähle, O.; Nassalski, J.; Neliba, S.; Neyret, D. P.; Nikolaenko, V. I.; Nozdrin, A. A.; Obraztsov, V. F.; Olshevsky, A. G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Peshekhonov, D. V.; Peshekhonov, V. D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Popov, A. A.; Pretz, J.; Procureur, S.; Quintans, C.; Ramos, S.; Reicherz, G.; Rozhdestvensky, A. M.; Rondio, E.; Sadovski, A. B.; Samoylenko, V. D.; Sandacz, A.; Sapozhnikov, M. G.; Savin, I. A.; Schiavon, P.; Schill, C.; Schmitt, L.; Shevchenko, O. Yu.; Shishkin, A. A.; Siebert, H.-W.; Sinha, L.; Sissakian, A. N.; Slunecka, M.; Smirnov, G. I.; Sozzi, F.; Sugonyaev, V. P.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sulc, M.; Sulej, R.; Takabayashi, N.; Tchalishev, V. V.; Tessarotto, F.; Teufel, A.; Tkatchev, L. G.; Virius, M.; Vlassov, N. V.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wirth, S.; Wi?licki, W.; Zaremba, K.; Zhao, J.; Ziegler, R.; Zvyagin, A.; Compass Collaboration

173

Spin asymmetry A1d and the spin-dependent structure function g1d of the deuteron at low values of x and Q  

Science.gov (United States)

We present a precise measurement of the deuteron longitudinal spin asymmetry A1d and of the deuteron spin-dependent structure function g1d at Q<1 GeV and 4×101d and g1d are found to be consistent with zero in the whole range of x.

Compass Collaboration; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Bade?ek, B.; Balestra, F.; Ball, J.; Baum, G.; Bedfer, Y.; Bernet, C.; Bertini, R.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M. P.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Costa, S.; Crespo, M. L.; D'Hose, N.; Dalla Torre, S.; Dasgupta, S. S.; de Masi, R.; Denisov, O. Yu.; Dhara, L.; Diaz Kavka, V.; Dinkelbach, A. M.; Donskov, S. V.; Dorofeev, V. A.; Doshita, N.; Duic, V.; Dünnweber, W.; Eversheim, P. D.; Eyrich, W.; Fabro, M.; Faessler, M.; Falaleev, V.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M.; Fischer, H.; Franz, J.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A. M.; Grajek, O. A.; Grasso, A.; Grube, B.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Hedicke, S.; Heinsius, F. H.; Hermann, R.; Heß, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Ilgner, C.; Ioukaev, A. I.; Ishimoto, S.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N. I.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Khomutov, N. V.; Kisselev, Yu.; Klein, F.; Koblitz, S.; Koivuniemi, J. H.; Kolosov, V. N.; Komissarov, E. V.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Korentchenko, A. S.; Korzenev, A.; Kotzinian, A. M.; Koutchinski, N. A.; Kravchuk, N. P.; Kroumchtein, Z. V.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M. E.; Lamanna, M.; Le Goff, J. M.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matsuda, T.; Maximov, A. N.; Meyer, W.; Mielech, A.; Mikhailov, Yu. V.; Moinester, M. A.; Nähle, O.; Nassalski, J.; Neliba, S.; Neyret, D. P.; Nikolaenko, V. I.; Nozdrin, A. A.; Obraztsov, V. F.; Olshevsky, A. G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Peshekhonov, D. V.; Peshekhonov, V. D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Popov, A. A.; Pretz, J.; Procureur, S.; Quintans, C.; Ramos, S.; Reicherz, G.; Rozhdestvensky, A. M.; Rondio, E.; Sadovski, A. B.; Samoylenko, V. D.; Sandacz, A.; Sapozhnikov, M. G.; Savin, I. A.; Schiavon, P.; Schill, C.; Schmitt, L.; Shevchenko, O. Yu.; Shishkin, A. A.; Siebert, H.-W.; Sinha, L.; Sissakian, A. N.; Slunecka, M.; Smirnov, G. I.; Sozzi, F.; Sugonyaev, V. P.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sulc, M.; Sulej, R.; Takabayashi, N.; Tchalishev, V. V.; Tessarotto, F.; Teufel, A.; Tkatchev, L. G.; Virius, M.; Vlassov, N. V.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wirth, S.; Wi?licki, W.; Zaremba, K.; Zhao, J.; Ziegler, R.; Zvyagin, A.

2007-04-01

174

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 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

175

Crossed molecular beams study of O({sup 1}D) reactions with H{sub 2} molecules  

Energy Technology Data Exchange (ETDEWEB)

Reaction dynamics of O({sup 1}D) atoms with H{sub 2} molecules was reinvestigated using the crossed molecular beams technique with pulsed beams. The O({sup 1}D) beam was generated by photodissociating O{sub 3} molecules at 248 nm. Time-of-flight spectra and the laboratory angular distribution of the OH products were measured. The derived OH product center-of-mass flux-velocity contour diagram shows more backward scattered intensity with respect to the O({sup 1}D) beam. In contrast to previous studies which show that the insertion mechanism is the dominant process, our results indicate that the contribution from the collinear approach of the O({sup 1}D) atom to the H{sub 2} molecule on the first excited state potential energy surface is significant and the energy barrier for the collinear approach is therefore minimal. Despite the increased time resolution in this experiment, no vibrational structure in the OH product time-of-flight spectra was resolved. This is in agreement with LIF studies, which have shown that the rotational distributions of the OH products in all vibrational states are broad and highly inverted.

Miau, T.T.

1995-05-01

176

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

177

A first-principles study on quasi-1D alkali metal chains within zeolite channels  

Science.gov (United States)

We report first-principles studies on systems formed by alkali metal (Na, K, or Rb) added to zeolite ITQ-4. Geometric and electronic structures of the quasi-1D chains of intercalated alkali metal atoms at experimental loading (4 metal atoms per 32 Si) are studied. Clear differences between different kinds of alkali metal are found, with a general trend of decreased ionization and less metallic character for the lighter alkali metals. Within the zeolite channels, it is possible to form insulated and metallic alkali metal chains by doping Na or Rb. Agreeing with experiments, only Rb here is found to be a good candidate to generate inorganic electride. We also predict that a large quantity of Na can be doped into the zeolite channel, while no more than 4 Rb per 16 Si can be doped.

Li, Zhenyu; Yang, Jinlong; Hou, J. G.; Zhu, Qingshi

2004-05-01

178

Deforming the D1D5 CFT away from the orbifold point  

CERN Document Server

The D1D5 brane bound state is believed to have an `orbifold point' in its moduli space which is the analogue of the free Yang Mills theory for the D3 brane bound state. The supergravity geometry generated by D1 and D5 branes is described by a different point in moduli space, and in moving towards this point we have to deform the CFT by a marginal operator: the `twist' which links together two copies of the CFT. In this paper we find the effect of this deformation operator on the simplest physical state of the CFT -- the Ramond vacuum. The twist deformation leads to a final state that is populated by pairs of excitations like those in a squeezed state. We find the coefficients characterizing the distribution of these particle pairs (for both bosons and fermions) and thus write this final state in closed form.

Avery, Steven G; Mathur, Samir D

2010-01-01

179

Deforming the D1D5 CFT away from the orbifold point  

Science.gov (United States)

The D1D5 brane bound state is believed to have an ‘orbifold point’ in its moduli space which is the analogue of the free Yang Mills theory for the D3 brane bound state. The supergravity geometry generated by D1 and D5 branes is described by a different point in moduli space, and in moving towards this point we have to deform the CFT by a marginal operator: the ‘twist’ which links together two copies of the CFT. In this paper we find the effect of this deformation operator on the simplest physical state of the CFT — the Ramond vacuum. The twist deformation leads to a final state that is populated by pairs of excitations like those in a squeezed state. We find the coefficients characterizing the distribution of these particle pairs (for both bosons and fermions) and thus write this final state in closed form.

Avery, Steven G.; Chowdhury, Borun D.; Mathur, Samir D.

2010-06-01

180

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

Directory of Open Access Journals (Sweden)

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

J. Misun

1993-11-01

 
 
 
 
181

Chaotic Encryption Scheme Using 1-D Chaotic Map  

Directory of Open Access Journals (Sweden)

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

Mina Mishra

2011-07-01

182

1D X-ray Beam Compressing Monochromators  

International Nuclear Information System (INIS)

A total beam compression of 5 and 10 corresponding to the asymmetry angles of 9 deg. and 12 deg. is achieved with V-5 and V-10 monochromators, respectively, in standard single crystal pure germanium (220) X-ray beam compressing (V-shaped) monochromators for CuK?1 radiation. A higher 1D compression of X-ray beam is possible using larger angles of asymmetry, however it is achieved at the expense of the total intensity, which is decreased due to the refraction effect. To increase the monochromator intensity, several ways are considered both theoretically and experimentally. Linearly graded germanium rich GexSi(1-x) single crystal was used to prepare a V-21 single crystal monochromator with 15 deg. asymmetry angles (compression factor of 21). Its temperature gradient version is discussed for CuK?1 radiation. X-ray diffraction measurements on the graded GeSi monochromator showed more than 3-times higher intensity at the output compared with that of a pure Ge monochromator.

183

Landau-Zener Tunneling in 1-d periodic potential  

Science.gov (United States)

Landau-Zener tunneling can be used to model the transition between energy bands of a particle in 1-d periodic potential [1-2]. It is pointed out that a specific model could be utilized to explain the transition driven by a uniform external force, between energy bands in a periodic lattice [3]. Here we examine the transition driven by an external force, in a sinusoidal periodic potential, by solving Schr"odinger equation numerically. As an exact solution, all bands and transitions between them are included. By considering arbitrary crystal potential of any supercell size, we can approximate random potential scattering and examine how random elastic scattering modifies the inter-band transition and eventually the electron transport. Non-exponential decays and other patterns for different ranges of parameters will be presented. We will also make a connection between the numerical results and conventional Landau-Zener transition model, and show how a time-dependent periodic potential will change the nature of transition. Supported by NSF.[4pt] [1] Zener, C., 1932, Proc. Roy. Soc. London Ser. A 137, 696.[0pt] [2] C. Zener, A theory of the electrical breakdown of solid dielectrics, Proc. Royal Soc. A 145 (1934) 523.[0pt] [3] Q. Niu and M. G. Raizen, Phys. Rev. Lett. 80, 3491(1998)

Li, Jiajun; Han, Jong

2013-03-01

184

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

185

Spin-charge separation in the 1D Hubbard model  

Science.gov (United States)

We demonstrate that the Configuration Interaction (CI) Approximation recaptures essential features of the exact solution of the 1D Hubbard model. The CI method systematically describes fluctuation and quantum tunneling corrections to the Hartree-Fock Approximation (HFA). HFA predicts that doping a half-filled Hubbard chain leads to the appearance of charged spin-polarons or charged domain-wall solitons in the antiferromagnetic (AFM) background. The CI method describes the quantum dynamics of these charged magnetic solitons. We test the accuracy of the CI method against the exact solution of the one-dimensional Hubbard model. We find remarkable agreement between the energy of the mobile charged bosonic domain-wall (as given by the CI method) and the exact energy of the doping hole (as given by the Bethe Ansatz) for the entire U/t range. The CI method also leads to a clear demonstration of the spin-charge separation. Addition of one doping hole to the half-filled antiferromagnetic chain results in the appearance of two different carriers: a charged bosonic domain-wall (which carries the charge but no spin) and a neutral spin-1/2 domain wall (which carries the spin but no charge).

Berciu, Mona; John, Sajeev

2000-03-01

186

Nanowires and 1D arrays fabrication: An overview  

International Nuclear Information System (INIS)

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

187

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

188

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

189

CD1d expression as a prognostic marker for chronic lymphocytic leukemia.  

Science.gov (United States)

We analyzed the expression of CD1d, an antigen-presenting molecule, on peripheral blood leukemic cells of cases of chronic lymphocytic leukemia (CLL) by flow cytometry. We demonstrated variable expression of CD1d on leukemic lymphocytes and an association between high expression of CD1d with shorter time to treatment and overall survival of patients. CD1d was positively associated with CD38 expression, but not with unmutated heavy chain variable (VH) mutational status or adverse cytogenetics of leukemic lymphocytes. Our findings support that CD1d expression is a prognostic marker for CLL. PMID:23668820

Anastasiadis, Athanasios; Kotsianidis, Ioannis; Papadopoulos, Vasileios; Spanoudakis, Emmanouil; Margaritis, Dimitrios; Christoforidou, Anna; Gouliamtzi, Stamatoula; Tsatalas, Costas

2014-02-01

190

&#x1D4A9;-Fuzzy Ideals in Ordered Semigroups  

Directory of Open Access Journals (Sweden)

Full Text Available We introduce the concept of &#x1D4A9;-fuzzy left (right ideals in ordered semigroups and characterize ordered semigroups in terms of &#x1D4A9;-fuzzy left (right ideals. We characterize left regular (right regular and left simple (right simple ordered semigroups in terms of &#x1D4A9;-fuzzy left (&#x1D4A9;-fuzzy right ideals. The semilattice of left (right simple semigroups in terms of &#x1D4A9;-fuzzy left (right ideals is discussed.

Muhammad Shabir

2009-01-01

191

Dynamics of the gas-liquid interfacial reaction of O(1D) with a liquid hydrocarbon.  

Science.gov (United States)

The dynamics of the gas-liquid interfacial reaction of the first electronically excited state of the oxygen atom, O((1)D), with the surface of a liquid hydrocarbon, squalane (C(30)H(62); 2,6,10,15,19,23-hexamethyltetracosane) has been studied experimentally. Translationally hot O((1)D) atoms were generated by 193 nm photolysis of a low pressure (nominally 1 mTorr) of N(2)O a short distance (mean = 6 mm) above a continually refreshed liquid squalane surface. Nascent OH (X(2)?, v' = 0) reaction products were detected by laser-induced fluorescence (LIF) on the OH A(2)?(+)-X(2)? (1,0) band at the same distance above the surface. The speed distribution of the recoiling OH was characterized by measuring the appearance profiles as a function of photolysis-probe delay for selected rotational levels, N'. The rotational (and, partially, fine-structure) state distributions were also measured by recording LIF excitation spectra at selected photolysis-probe delays. The OH v' = 0 rotational distribution is bimodal and can be empirically decomposed into near thermal (~300 K) and much hotter (~6000 K) Boltzmann-temperature components. There is a strong positive correlation between rotational excitation and translation energy. However, the colder rotational component still represents a significant fraction (~30%) of the fastest products, which have substantially superthermal speeds. We estimate an approximate upper limit of 3% for the quantum yield of OH per O((1)D) atom that collides with the surface. By comparison with established mechanisms for the corresponding reactions in the gas phase, we conclude that the rotationally and translationally hot products are formed via a nonstatistical insertion mechanism. The rotationally cold but translationally hot component is most likely produced by direct abstraction. Secondary collisions at the liquid surface of products of either of the previous two mechanisms are most likely responsible for the rotationally and translationally cold products. We do not think it likely, a priori, that they could be produced in the observed significant yield via a statistical insertion mechanism for a molecule the size of squalane embedded in a surrounding liquid surface. PMID:21473641

Waring, Carla; King, Kerry L; Costen, Matthew L; McKendrick, Kenneth G

2011-06-30

192

Structural and population-based evaluations of TBC1D1 p.Arg125Trp.  

Science.gov (United States)

Obesity is now a leading cause of preventable death in the industrialised world. Understanding its genetic influences can enhance insight into molecular pathogenesis and potential therapeutic targets. A non-synonymous polymorphism (rs35859249, p.Arg125Trp) in the N-terminal TBC1D1 phosphotyrosine-binding (PTB) domain has shown a replicated association with familial obesity in women. We investigated these findings in the Avon Longitudinal Study of Parents and Children (ALSPAC), a large European birth cohort of mothers and offspring, and by generating a predicted model of the structure of this domain. Structural prediction involved the use of three separate algorithms; Robetta, HHpred/MODELLER and I-TASSER. We used the transmission disequilibrium test (TDT) to investigate familial association in the ALSPAC study cohort (N?=?2,292 mother-offspring pairs). Linear regression models were used to examine the association of genotype with mean measurements of adiposity (Body Mass Index (BMI), waist circumference and Dual-energy X-ray absorptiometry (DXA) assessed fat mass), and logistic regression was used to examine the association with odds of obesity. Modelling showed that the R125W mutation occurs in a location of the TBC1D1 PTB domain that is predicted to have a function in a putative protein:protein interaction. We did not detect an association between R125W and BMI (mean per allele difference 0.27 kg/m(2) (95% Confidence Interval: 0.00, 0.53) P?=?0.05) or obesity (odds ratio 1.01 (95% Confidence Interval: 0.77, 1.31, P?=?0.96) in offspring after adjusting for multiple comparisons. Furthermore, there was no evidence to suggest that there was familial association between R125W and obesity (?(2)?=?0.06, P?=?0.80). Our analysis suggests that R125W in TBC1D1 plays a role in the binding of an effector protein, but we find no evidence that the R125W variant is related to mean BMI or odds of obesity in a general population sample. PMID:23667688

Richardson, Tom G; Thomas, Elaine C; Sessions, Richard B; Lawlor, Debbie A; Tavaré, Jeremy M; Day, Ian N M

2013-01-01

193

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.-Hasbi, A., Perreault, M. L., Shen, M. Y. F., Zhang, L., To, R., Fan, T., Nguyen, T., Ji, X., O'Dowd, B. F., George, S. R. 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. 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

194

Robust fractal characterization of 1D and 2D signals  

Science.gov (United States)

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

Avadhanam, Niranjan; Mitra, Sunanda

1993-10-01

195

A 1d Traffic Model with Threshold Parameters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The basic properties of traffic flow are analyzed using a simple deterministic one dimensional "car following model" with continuous variables based on a model introduced by Nagel and Herrmann [Physica A 199 254--269 (1993)] including a few modifications. As a first case we investigate the creation and propagation of jams in a platoon generated by a slow leading vehicle. In a second case we look at a system with the size L, periodic boundary conditions and identical vehicles...

Sauermann, G.; Herrmann, H. J.

1997-01-01

196

Calibração binocular com gabaritos 1D sem restrição demovimentos / Binocular calibration with 1D parttern without movements restriction  

Scientific Electronic Library Online (English)

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

José Alexandre de, França; Maria Bernadete de M., França; Marcelo Ricardo, Stemmer; Rodrigo Henrique C., Palácios.

2011-06-01

197

Calibração binocular com gabaritos 1D sem restrição demovimentos / Binocular calibration with 1D parttern without movements restriction  

Scientific Electronic Library Online (English)

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

José Alexandre de, França; Maria Bernadete de M., França; Marcelo Ricardo, Stemmer; Rodrigo Henrique C., Palácios.

198

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

International Nuclear Information System (INIS)

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

199

Maxwell-Dirac chiral equations in (3+1)D exactly integrable; Equacoes de Maxwell-Dirac quirais em (3+1)D exatamente integraveis  

Energy Technology Data Exchange (ETDEWEB)

We study the integrability of the (3+1)-dimension chiral Maxwell-Dirac (Weyl) equations, in a formalism with local causality preservation. One characteristic of these formalisms is that even in (3+1)D we have a (3+1+D dynamic because there is no participation of the spatial coordinates orthogonal to the direction of the interaction(quantum exchange). The dynamic is conformal invariant and the equations became exactly integrable

Souza, Manoelito Martins de [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Fisica

1994-12-31

200

PSS-3D1D: an improved 3D1D profile method of protein fold recognition for the annotation of twilight zone sequences.  

Science.gov (United States)

Annotation of any newly determined protein sequence depends on the pairwise sequence identity with known sequences. However, for the twilight zone sequences which have only 15-25% identity, the pair-wise comparison methods are inadequate and the annotation becomes a challenging task. Such sequences can be annotated by using methods that recognize their fold. Bowie et al. described a 3D1D profile method in which the amino acid sequences that fold into a known 3D structure are identified by their compatibility to that known 3D structure. We have improved the above method by using the predicted secondary structure information and employ it for fold recognition from the twilight zone sequences. In our Protein Secondary Structure 3D1D (PSS-3D1D) method, a score (w) for the predicted secondary structure of the query sequence is included in finding the compatibility of the query sequence to the known fold 3D structures. In the benchmarks, the PSS-3D1D method shows a maximum of 21% improvement in predicting correctly the ? + ? class of folds from the sequences with twilight zone level of identity, when compared with the 3D1D profile method. Hence, the PSS-3D1D method could offer more clues than the 3D1D method for the annotation of twilight zone sequences. The web based PSS-3D1D method is freely available in the PredictFold server at http://bioinfo.bdu.ac.in/servers/ . PMID:22160493

Ganesan, K; Parthasarathy, S

2011-12-01

 
 
 
 
201

Competing Regimes of Motion of 1D Mobile Impurities  

Science.gov (United States)

We show that a distinguishable mobile impurity inside a one-dimensional many-body state at zero temperature generally does not behave like a quasiparticle. Instead, both the impurity dynamics as well as the ground state of the bath are fundamentally transformed by a diverging number of zero-energy excitations being generated, leading to what we call infrared-dominated (ID) dynamics. Combining analytics and density matrix renormalization group numerics, we provide a general formula for the power law governing ID dynamics at zero momentum, discuss a threshold beyond which quasiparticle dynamics may occur again, and study the competition between the ID and quasiparticle universality classes at larger impurity momenta.

Kantian, A.; Schollwöck, U.; Giamarchi, T.

2014-08-01

202

Human cytomegalovirus (HCMV) US2 protein interacts with human CD1d (hCD1d) and down-regulates invariant NKT (iNKT) cell activity.  

Science.gov (United States)

To avoid host immune surveillance, human cytomegalovirus (HCMV) encoded endoplasmic reticulum (ER)-membrane glycoprotein US2, which interferes with antigen presenting mechanism of Major histocompatibility complex (MHC) class Ia and class II molecules. However, not many attempts have been made to study the effect of HCMV US2 on the expression of MHC class Ib molecules. In this study, we examined the effect of HCMV US2 on the expression and function of human CD1d (hCD1d), which presents glycolipid antigens to invariant NKT (iNKT) cells. Our results clearly showed that the physiological interaction between ER lumenal domain of HCMV US2 and ?3 domain of hCD1d was observed within ER. Compared with mature form of hCD1d, immature form of hCD1d is more susceptible to ubiquitin-dependent proteasomal degradation mediated by HCMV US2. Moreover, the ectopic expression of HCMV US2 leads to the down-modulation of iNKT cell activity without significant change of hCD1d expression. These results will advance our understanding of the function of HCMV US2 in immune evasive mechanisms against anti-viral immunity of iNKT cells. PMID:24213674

Han, Jihye; Rho, Seung Bae; Lee, Jae Yeon; Bae, Joonbeom; Park, Se Ho; Lee, Suk Jun; Lee, Sang Yeol; Ahn, Curie; Kim, Jae Young; Chun, Taehoon

2013-11-01

203

Molecular characterization of the maize Rp1-D rust resistance haplotype and its mutants.  

Science.gov (United States)

The Rp1-D gene for resistance to maize common rust (Puccinia sorghi) is a member of a complex locus (haplotype) composed of Rp1-D and approximately eight other gene homologs. The identity of Rp1-D was demonstrated by using two independent gene-tagging approaches with the transposons Mutator and Dissociation. PIC20, a disease resistance (R) gene analog probe previously mapped to the rp1 locus, detected insertion of Dissociation in an Rp1-D mutation and excision in three revertants. Independent libraries probed with the PIC20 or Mutator probes resulted in isolation of the same gene sequence. Rp1-D belongs to the nucleotide binding site, leucine-rich repeat class of R genes. However, unlike the rust resistance genes M and L6 from flax, the maize Rp1-D gene does not encode an N-terminal domain with similarity to the signal transduction domains of the Drosophila Toll protein and mammalian interleukin-1 receptor. Although the abundance of transcripts of genes from the rp1 complex changed with leaf age, there was no evidence of any change due to inoculation with avirulent or virulent rust biotypes. A set of 27 Rp1-D mutants displayed at least nine different deletions of Rp1-D gene family members that were consistent with unequal crossing-over events. One mutation (Rp1-D*-24) resulted in deletion of all but one gene family member. Other unique deletions were observed in the disease lesion mimic Rp1-D*-21 and the partially susceptible mutant Rp1-D*-5. Different rp1 specificities have distinct DNA fingerprints (haplotypes). Analysis of recombinants between rp1 specificities indicated that recombination had occurred within the rp1 gene complex. Similar analyses indicated that the rust R genes at the rp5 locus, 2 centimorgans distal to rp1, are not closely related to Rp1-D. PMID:10402435

Collins, N; Drake, J; Ayliffe, M; Sun, Q; Ellis, J; Hulbert, S; Pryor, T

1999-07-01

204

Spatial and temporal expression of the beta1D integrin during mouse development.  

Science.gov (United States)

The beta1D protein is a recently characterized isoform of the integrin beta1 subunit that is present in cardiac and skeletal muscles. In this study, we have examined the expression of beta1D in different types of skeletal muscle and in cardiac muscle and studied its distribution during mouse development, using new monoclonal antibodies specific for beta1D. Immunoprecipitation studies revealed that, while beta1A is strongly expressed in proliferating C2C12 myoblasts, beta1D is only expressed after their differentiation to myotubes. In these myotubes, beta1D is associated with different alpha subunits, namely alpha3A, alpha5, alpha7A, or alpha7B. Initially, during embryogenesis, the alpha1A subunit is the only beta1 variant expressed in skeletal and cardiac muscle. The beta1D subunit is first detected in skeletal muscle at E17.5, whereas in cardiac muscle its expression begins around the time of birth. Later the expression of beta1A in skeletal and cardiac muscle becomes restricted to capillary cells, whereas beta1D eventually becomes the only variant expressed in adult cardiac and skeletal muscle cells. The switch from the beta1A to the beta1D subunit in cardiac muscle cells coincides with the expression of alpha7. In adults there is a distinct concentration of beta1D at the myotendinous junctions of muscle fibers and at costameres in both cardiac and skeletal muscle. In addition, beta1D is present at intercalated discs in cardiac muscle and at neuromuscular junctions in skeletal muscle cells. The amount of beta1D in different types of skeletal muscle (fast, slow, and mixed-type) was similar, but cardiac muscle expressed almost five times as much of this protein. We suggest that beta1D plays a role in the maintenance of the cytoarchitecture of mature muscle and in the functional integrity of the muscle cells. PMID:9415431

van der Flier, A; Gaspar, A C; Thorsteinsdóttir, S; Baudoin, C; Groeneveld, E; Mummery, C L; Sonnenberg, A

1997-12-01

205

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

206

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

207

[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

208

Therapeutic implications of CD1d expression and tumor-infiltrating macrophages in pediatric medulloblastomas.  

Science.gov (United States)

Immunobiology of medulloblastoma (MB), the most common malignant brain tumor in children, is poorly understood. Although tumor cells in some MBs were recently shown to express CD1d and be susceptible to V?24-invariant natural killer T (NKT)-cell cytotoxicity, the clinical relevance of CD1d expression in MB patients remains unknown. We investigated the expression of CD1d in pediatric MBs and correlated with molecular and clinical characteristics. Specifically, we explored if NKT cell therapy can be targeted at a subset of pediatric MBs with poorer prognosis. Particularly, infantile MBs have a worse outcome because radiotherapy is delayed to avoid neurocognitive sequelae. Immunohistochemistry for CD1d was performed on a screening set of 38 primary pediatric MBs. Gene expression of the membrane form of M2 macrophage marker, CD163, was studied in an expanded cohort of 60 tumors. Outcome data was collected prospectively. Thirteen of 38 MBs (34.2 %) expressed CD1d on immunohistochemistry. CD1d was expressed mainly on MB tumor cells, and on some tumor-associated macrophages. Majority (18/22, 82 %) of non sonic-hedgehog/Wingless-activated MBs (group 3 and 4) were CD1d-negative (p = 0.05). A subset of infantile MBs (4/9, 44.4 %) expressed CD1d. Macrophages infiltrating MB expressed CD163 apart from CD1d. Molecular subtypes demonstrated statistical differences in CD163 expression, SHH-tumors were the most enriched (p = 0.006). Molecular and clinical subtypes of pediatric MB exhibit distinct differences in CD1d expression, which have important therapeutic implications. High CD1d expression in infantile MBs offers potential new immunotherapeutic treatment with NKT cell therapy in infants, where treatment is suboptimal due delayed radiotherapy. PMID:25115738

Teo, Wan-Yee; Elghetany, M Tarek; Shen, Jianhe; Man, Tsz-Kwong; Li, Xiaonan; Chintagumpala, Murali; Su, Jack Meng Fen; Dauser, Robert; Whitehead, William; Adesina, Adekunle M; Lau, Ching C

2014-11-01

209

Control oriented 1D electrochemical model of lithium ion battery  

International Nuclear Information System (INIS)

Lithium ion (Li-ion) batteries provide high energy and power density energy storage for diverse applications ranging from cell phones to hybrid electric vehicles (HEVs). For efficient and reliable systems integration, low order dynamic battery models are needed. This paper introduces a general method to generate numerically a fully observable/controllable state variable model from electrochemical kinetic, species and charge partial differential equations that govern the discharge/charge behavior of a Li-ion battery. Validated against a 313th order nonlinear CFD model of a 6 Ah HEV cell, a 12th order state variable model predicts terminal voltage to within 1% for pulse and constant current profiles at rates up to 50 C. The state equation is constructed in modal form with constant negative real eigenvalues distributed in frequency space from 0 to 10 Hz. Open circuit potential, electrode surface concentration/reaction distribution coupling and electrolyte concentration/ionic conductivity nonlinearities are explicitly approximated in the model output equation on a local, electrode-averaged and distributed basis, respectively. The balanced realization controllability/observability gramian indicates that the fast electrode surface concentration dynamics are more observable/controllable than the electrode bulk concentration dynamics (i.e. state of charge)

210

Refractive statistical concave 1D diffusers for laser beam shaping  

Science.gov (United States)

Certain high power laser applications require thin homogeneous laser lines. A possible concept to generate the necessary flat-top profile uses multi-aperture elements followed by a lens to recombine separated beamlets. Advantages of this concept are the independence from entrance intensity profile and achromaticity. However, the periodic structure and the overlapping of beamlets produce interference effects especially when highly coherent light is used. Random optical elements that diffuse only in one direction can reduce the contrast of the interference pattern. Losses due to undesired diffusion in large angles have to be minimized to maintain a good quality and high efficiency of beam shaping. We have fabricated diffusers made of fused silica for a wide range of wavelengths that diffuse only in one direction. Structures are based on an array of concave cylindrical microlenses with locally varying size and position following a well defined statistical distribution. The scattering angle can be influenced by process parameters and is typically between 1° and 60°. To predict the influence of process parameters on the optical properties, a simplified model for the fabrication process and geometrical optics have been used. Characterization of the fabricated devices was done by stylus measurements for the surface shapes, microinterferometry to measure phase profiles and high resolution goniometry to obtain far field distribution of light. The simulated data compare very well to measured optical properties. Based on our simulation tool we discuss limits of our fabrication method and optimal fabrication parameters.

Bitterli, Roland; Kim, Myunsik; Scharf, Toralf; Herzig, Hans-Peter; Bich, Andreas; Dumouchel, Christine; Roth, Sylvain; Völkel, Reinhard; Weible, K. J.

2008-08-01

211

Oxidation characteristics of silicon exposed to O(1D2) and O(3P2) radicals and stress-relaxation oxidation model for O(1D2) radicals  

Science.gov (United States)

We investigated the oxidation of silicon by O(1D2) and O(3P2) radicals in a microwave plasma at 673 K in an Ar/O2 atmosphere containing a small amount of hydrogen. O(1D2) radical oxidation with hydrogen gave a much higher growth rate than wet thermal oxidation at 1223 K. The activation energies for the parabolic rate constant owing to O(1D2) and O(3P2) radical oxidations were respectively 0.18 and 0.40 eV, which are much lower than that (0.71 eV) by thermal oxidation. In time-dependent dielectric breakdown tests, despite SiO2 films formed by radicals having a higher degradation rate than those produced by thermal oxidation, SiO2 films formed by O(1D2) radicals had longer lifetimes. Our dielectric breakdown model indicates this is due to the flat SiO2 surface and interface suppressing two-dimensional local breakdown. A stress-relaxation oxidation model for O(1D2) radicals is proposed that well explains the formation of flat SiO2 surfaces and interfaces.

Kabe, Yoshiro; Hasunuma, Ryu; Yamabe, Kikuo

2014-03-01

212

Facility for testing performance of 1-D position sensitive neutron detectors at Apsara reactor, Trombay  

International Nuclear Information System (INIS)

Full text: We have set up a test facility for 1-D position sensitive neutron detectors at tangential beam hole no.9 of Apsara, a medium flux (1012 n/cm2/sec) research reactor. The description of neutron beam collimator, detector shielding, 1- D PSD and its testing electronics, procedure of testing and various characteristic parameters measured are reported in this paper

213

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.

Cédile, Oriane

2011-01-01

214

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-02-01

215

Q1D organic metals the electronic contribution to the equation of state  

CERN Document Server

Starting from the recently derived expression for the chemical potential of the electron gas on a 1D lattice,and a well known thermodynamical relation,we have obtained the equation of state of the electron gas on a 1D lattice.

Celebonovic, V

1997-01-01

216

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

Directory of Open Access Journals (Sweden)

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

Werner Dieter

2002-09-01

217

Hyperbranched quasi-1D nanostructures for solid-state dye-sensitized solar cells.  

Science.gov (United States)

In this work we demonstrate hyperbranched nanostructures, grown by pulsed laser deposition, composed of one-dimensional anatase single crystals assembled in arrays of high aspect ratio hierarchical mesostructures. The proposed growth mechanism relies on a two-step process: self-assembly from the gas phase of amorphous TiO2 clusters in a forest of tree-shaped hierarchical mesostructures with high aspect ratio; oriented crystallization of the branches upon thermal treatment. Structural and morphological characteristics can be optimized to achieve both high specific surface area for optimal dye uptake and broadband light scattering thanks to the microscopic feature size. Solid-state dye sensitized solar cells fabricated with arrays of hyperbranched TiO2 nanostructures on FTO-glass sensitized with D102 dye showed a significant 66% increase in efficiency with respect to a reference mesoporous photoanode and reached a maximum efficiency of 3.96% (among the highest reported for this system). This result was achieved mainly thanks to an increase in photogenerated current directly resulting from improved light harvesting efficiency of the hierarchical photoanode. The proposed photoanode overcomes typical limitations of 1D TiO2 nanostructures applied to ss-DSC and emerges as a promising foundation for next-generation high-efficiency solid-state devices comprosed of dyes, polymers, or quantum dots as sensitizers. PMID:24180577

Passoni, Luca; Ghods, Farbod; Docampo, Pablo; Abrusci, Agnese; Martí-Rujas, Javier; Ghidelli, Matteo; Divitini, Giorgio; Ducati, Caterina; Binda, Maddalena; Guarnera, Simone; Li Bassi, Andrea; Casari, Carlo Spartaco; Snaith, Henry J; Petrozza, Annamaria; Di Fonzo, Fabio

2013-11-26

218

Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag  

Directory of Open Access Journals (Sweden)

Full Text Available Vegetation fires emit hot gases and particles which are rapidly transported upward by the positive buoyancy generated by the combustion process. In general, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. In this paper, we revisit the parameterization of the vertical transport of hot gases and particles emitted from vegetation fires, described in Freitas et al. (2007, to include the effects of environmental wind on transport and dilution of the smoke plume at its scale. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to simulate the time evolution of the plume rise and the smoke injection height. One-dimensional (1-D model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three-dimensional (3-D Active Tracer High resolution Atmospheric Model (ATHAM. We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

S. R. Freitas

2010-01-01

219

Light-Directing Chiral Liquid Crystal Nanostructures: From 1D to 3D.  

Science.gov (United States)

Conspectus Endowing external, remote, and dynamic control to self-organized superstructures with desired functionalities is a principal driving force in the bottom-up nanofabrication of molecular devices. Light-driven chiral molecular switches or motors in liquid crystal (LC) media capable of self-organizing into optically tunable one-dimensional (1D) and three-dimensional (3D) superstructures represent such an elegant system. As a consequence, photoresponsive cholesteric LCs (CLCs), i.e., self-organized 1D helical superstructures, and LC blue phases (BPs), i.e., self-organized 3D periodic cubic lattices, are emerging as a new generation of multifunctional supramolecular 1D and 3D photonic materials in their own right because of their fundamental academic interest and technological significance. These smart stimuli-responsive materials can be facilely fabricated from achiral LC hosts by the addition of a small amount of a light-driven chiral molecular switch or motor. The photoresponsiveness of these materials is a result of both molecular interaction and geometry changes in the chiral molecular switch upon light irradiation. The doped photoresponsive CLCs undergo light-driven pitch modulation and/or helix inversion, which has many applications in color filters, polarizers, all-optical displays, optical lasers, sensors, energy-saving smart devices, and so on. Recently, we have conceptualized and rationally synthesized different light-driven chiral molecular switches that have very high helical twisting powers (HTPs) and exhibit large changes in HTP in different states, thereby enabling wide phototunability of the systems by the addition of very small amounts of the molecular switches into commercially available achiral LCs. The light-driven chiral molecular switches are based on well-recognized azobenzene, dithienylcyclopentene, and spirooxazine derivatives. We have demonstrated high-resolution and lightweight photoaddressable displays without patterned electronics on flexible substrates. The wide tunability of the HTP furnishes reflection colors encompassing the whole visible spectrum and beyond in a reversible manner. Photomodulation of the helical pitch of the CLCs has been achieved by UV, visible, and near-infrared (NIR) light irradiation. NIR-light-induced red, green, and blue (RGB) reflections have been leveraged only by varying the power density of the IR laser. Some chiral switches are found to confer helix inversion to the cholesteric systems, which qualifies the CLCs for applications where circularly polarized light is involved. Dynamic and static primary RGB reflection colors have been achieved in a single film. LC BPs have been fabricated and investigated in the context of self-organized 3D photonic band gap (PBG) materials, and dynamic phototuning of the PBG over the visible region has been achieved. Omnidirectional lasing and tuning of the laser emission wavelength have also been attained in monodisperse photoresponsive CLC microshells fabricated by a capillary-based microfluidic technique. This Account covers the research and development in our laboratory starting from the design concepts and synthesis of photodynamic chiral molecular switches to their applications in the fabrication of photoresponsive CLCs and BPs. Potential and demonstrated practical applications of photoresponsive CLCs, microshells, and BPs are discussed, and the Account concludes with a brief forecast of what lies beyond the horizon in this rapidly expanding and fascinating field. PMID:25181560

Bisoyi, Hari Krishna; Li, Quan

2014-10-21

220

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

 
 
 
 
221

The FC-1D: The profitable alternative Flying Circus Commercial Aviation Group  

Science.gov (United States)

The FC-1D was designed as an advanced solution for a low cost commercial transport meeting or exceeding all of the 1993/1994 AIAA/Lockheed request for proposal requirements. The driving philosophy behind the design of the FC-1D was the reduction of airline direct operating costs. Every effort was made during the design process to have the customer in mind. The Flying Circus Commercial Aviation Group targeted reductions in drag, fuel consumption, manufacturing costs, and maintenance costs. Flying Circus emphasized cost reduction throughout the entire design program. Drag reduction was achieved by implementation of the aft nacelle wing configuration to reduce cruise drag and increase cruise speeds. To reduce induced drag, rather than increasing the wing span of the FC-1D, spiroids were included in the efficient wing design. Profile and friction drag are reduced by using riblets in place of paint around the fuselage and empennage of the FC-1D. Choosing a single aisle configuration enabled the Flying Circus to optimize the fuselage diameter. Thus, reducing fuselage drag while gaining high structural efficiency. To further reduce fuel consumption a weight reduction program was conducted through the use of composite materials. An additional quality of the FC-1D is its design for low cost manufacturing and assembly. As a result of this design attribute, the FC-1D will have fewer parts which reduces weight as well as maintenance and assembly costs. The FC-1D is affordable and effective, the apex of commercial transport design.

Meza, Victor J.; Alvarez, Jaime; Harrington, Brook; Lujan, Michael A.; Mitlyng, David; Saroughian, Andy; Silva, Alex; Teale, Tim

1994-01-01

222

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-01-01

223

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.

224

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

225

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

226

Universal Transverse Conductance between Quantum Hall Regions and (2+1)D Bosonization  

CERN Document Server

Using bosonization techniques for (2+1)D systems, we show that the transverse conductance for a system with general current interactions, when measured between perfect Hall regions is not renormalized at low temperatures. Our method extends and combines two results we have recently obtained on low dimensional fermionic systems: on the one hand, the relationship between universality of Landauer conductance and universality of bosonization rules for (1+1)D systems, and on the other hand, the universal character of the bosonized topological current associated to a (2+1)D fermionic system with current interaction.

Barci, D G; Barci, Daniel G.

2000-01-01

227

Spatial and frequency domain effects of defects in 1D photonic crystal  

CERN Document Server

The aim of this paper is to present the analysis of influence of defects in 1D photonic crystal (PC) on the density of states and simultaneously spontaneous emission, in both spatial and frequency domains. In our investigations we use an analytic model of 1D PC with defects. Our analysis reveals how presence of a defect causes a defect mode to appear. We show that a defect in 1D PC has local character, being negligible in regions of PC situated far from the defected elementary cell. We also analyze the effect of multiple defects, which lead to photonic band gap splitting.

Rudzi?ski, A; Szczepa?ski, P; 10.1007/s11082-007-9095-3

2009-01-01

228

Design, synthesis, and functional activity of labeled CD1d glycolipid agonists.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Invariant natural killer T cells (iNKT cells) are restricted by CD1d molecules and activated upon CD1d-mediated presentation of glycolipids to T cell receptors (TCRs) located on the surface of the cell. Because the cytokine response profile is governed by the structure of the glycolipid, we sought a method for labeling various glycolipids to study their in vivo behavior. The prototypical CD1d agonist, ?-galactosyl ceramide (?-GalCer) 1, instigates a powerful immune response and the generati...

Jervis, Pj; Polzella, P.; Wojno, J.; Jukes, Jp; Ghadbane, H.; Garcia Diaz, Yr; Besra, Gs; Cerundolo, V.; Cox, Lr

2013-01-01

229

Cutting edge: nonglycosidic CD1d lipid ligands activate human and murine invariant NKT cells.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Invariant NKT cells (iNKT cells) recognize CD1d/glycolipid complexes. We demonstrate that the nonglycosidic compound threitolceramide efficiently activates iNKT cells, resulting in dendritic cell (DC) maturation and the priming of Ag-specific T and B cells. Threitolceramide-pulsed DCs are more resistant to iNKT cell-dependent lysis than alpha-galactosylceramide-pulsed DCs due to the weaker affinity of the human iNKT TCR for CD1d/ threitolceramide than CD1d/alpha-galactosylceramide complexes. ...

Silk, Jd; Salio, M.; Reddy, Bg; Shepherd, D.; Gileadi, U.; Brown, J.; Masri, Sh; Polzella, P.; Ritter, G.; Besra, Gs; Jones, Ey; Schmidt, Rr; Cerundolo, V.

2008-01-01

230

Numerical simulation of the 1D and 2D Hubbard models  

International Nuclear Information System (INIS)

This paper investigates the ground state of the 1D and the 2D (square lattice) finite-sized Hubbard model for variable filling using a novel quantum simulation method. The authors have studied up to 256 sites for both 1D and 2D. Away from half filling the 2D antiferromagnetic order is initially destroyed, albeit without any clear sign of a Fermi liquid behavior. A metallic jump in n(k) appears only very far from half filling. In the 1D case, by contrast, a Fermi liquid-like jump in n(k) is obtained even very close to half filling

231

D1-D3 (or $\\bar{\\textrm{D}3}$) Systems with Fluxes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this article we study D1-D3 (or $\\bar{\\textrm{D}3}$) brane systems with generic constant electric and magnetic fluxes in IIB string theory. We work out all possible supersymmetric configurations and find out via T-duality all of them and corresponding supersymmetry conditions could be related to the supersymmetric intersecting D1-D1 pairs. And we do D1-D3 (or $\\bar{\\textrm{D}3}$) open string quantization for a class of configurations. We find that there are many near mass...

Chen, Bin; Liu, Xiao

2008-01-01

232

D1-D3 (or D3-bar) systems with fluxes  

International Nuclear Information System (INIS)

In this article we study D1-D3 (or D3-bar) brane systems with generic constant electric and magnetic fluxes in IIB string theory. We work out all possible supersymmetric configurations and find out via T-duality all of them and corresponding supersymmetry conditions could be related to the supersymmetric intersecting D1-D1 pairs. And we do D1-D3 (or D3-bar) open string quantization for a class of configurations. We find that there are many near massless states in NS sector for near-BPS configurations. Furthermore we calculate open string pair creation rate in generic nonsupersymmetric configurations.

233

Synthesis and Electron Field-Emission of 1-D Carbon-Related Nanostructured Materials  

Science.gov (United States)

Carbon nanotubes, a new stable form of carbon that was first identified in 1991 [1], are fullerene-related structures which consist of graphitic cylinders closed at either end with caps containing pentagonal rings. Although carbon nanotube structures are closely related to graphite, the curvature, symmetry and small size induce marked deviations from the graphitic behavior. Various methods have been used to produce carbon nanotubes, e.g., arc-discharge, laser-vaporization, catalytic chemical vapor deposition, but too many impurities also be produced, such as fullerenes, carbon nanoparticles and amorphous carbons. The microwave plasma enhanced chemical vapor deposition (MPECVD) system has been used to grow carbon nanotubes in this work and other 1-D carbon-related nanostructured materials was synthesized by the electron cyclotron resonance (ECR) plasma system. Plasma is generated by microwave excitation at 2.45 GHz by a magnetron passes through a waveguide and fed perpendicularly through a quartz dome into an 875 G magnetic field generated by the coils surrounding the resonance volume that creates the ECR condition. The deposition chamber was pumped down to the base pressure of 6.7X10-4 Pa (5X10-6 Torr) with a turbomolecular pump for ECR-plasma and subatmospheric pressures for MPECVD by a rotary mechanical pump. Well-aligned carbon-related nanostructures have been synthesized in nanoporous alumina or silicon with a uniform diameter of 30-100 nm by microwave excited plasma of CH_4, C_2H_2, N_2, H2 and Ar precursors. Nickel nanowires not only serve as catalysts to decompose hydrocarbons to form nanostructures but also function as an electrical conductor for other advanced applications. A negative dc bias is always applied to the substrate to promote the flow of ion fluxes through the nanochannels of the template materials that facilitate the physical adsorption and subsequent chemical absorption in the formation of carbon- and carbon-nitride nanotubes[2]. The electron field emission characteristics of the 1-D carbon-related nanostructures were measured by the conventional diode method at an ambient pressure of 1.3X10-3 Pa (10-5 Torr). The films (1X1-cm^2) were separated from the anode by ITO (indium tin oxide) coated glass, where a glass fiber spacer was maintained at 150 ?m from the cathode. The current density and electric field characteristics were measured using a Keithley 237 electrometer. A range of onset electron emission field from 3.5 to 1.5 V/?m and an emission current density up to 1 mA/cm^2 at 3V/?m have been achieved in this study, apparently superior to other carbon-based electron field emitters[3]. The results were reproducible over a period of weeks and the nanotubes did not degrade physically when exposing to a humid air of RH 90using the Fowler-Nordheim model, I=aV^2 exp (-b?_e^3/2/V) , where a and b are constants. The turn-on voltage was estimated as the voltage deviating from ln(I/V^2)-1/V curve. The effective work function (?_e=?/?) of the arrayed carbon nanotubes was calculated from the slope of the Fowler-Nordheim plot, where the value of ?, the field enhancement factor, was found to be 1517. This value increased to 3357 when nitrogen was doped, but decreased to 974 when boron was doped. The incorporation of nitrogen or boron into the carbon network apparently changes the original nanostructure and the chemical bonding. The structural and compositional modification by the incorporation of nitrogen, boron, or hydrogen into the 1-D carbon-related nanostructured materials were analyzed by FTIR , XPS , Raman spectroscopy , and FE-SEM . Various forms in connection with 1-D nanostructured materials applicable to the NEMS , e.g. , nanowelding of nanotubes[4], tubes on tube , open-end nanotubes and coils of nanofiber and nanotubes have been produced in this research depending on the plasma chemistry, catalytic effect and the design of template. [1]. S. Iijima, Nature 354, 56 (1991). [2]. S. L. Sung, S. H. Tsai, C. H. Tseng, X. W. Liu, and H. C. Shih, Appl. Phys. Lett. 74, 197 (1999). [3]. S. H. Tsai,

Shih, Han C.

2002-10-01

234

Quantum and semi-classical transport in RTDs using NEMO 1-D  

Science.gov (United States)

NEMO 1-D has been developed primarily for the simulation of resonant tunneling diodes, and quantitative and predictive agreements with experimental high performance, high current density devices have been achieved in the past.

Klimeck, G.; Stout, P.; Bowen, R. C.

2003-01-01

235

The importance of B cell CD1d expression for humoral immunity.  

Science.gov (United States)

It was reported over a decade previously that CD1d-restricted Natural Killer T (NKT) cells could interact with CD1d-expressing B cells and facilitate antibody secretion. Since then, several studies have observed that NKT cells can provide B-cell help for production of antibody against model and pathogen-derived glycolipids, carbohydrates and proteins. In regard to T cell-dependent protein antigens, it is still not entirely clear to what extent cognate interactions between CD1d-expressing B cells and NKT cells contribute to initial and long-lived B-cell responses that are characteristic of such antigens. In this editorial, we review evidence that NKT cells provide CD1d-dependent cognate and non-cognate forms of B-cell help following immunization with protein antigen. Elucidating these mechanisms will be important for harnessing NKT cells during vaccination. PMID:24946838

Lang, Mark L

2014-11-01

236

Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag  

Directory of Open Access Journals (Sweden)

Full Text Available We revisit the parameterization of the vertical transport of hot gases and particles emitted from biomass burning, described in Freitas et al. (2007, to include the effects of environmental wind on transport and dilution of the smoke plume at the cloud scale. Typically, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to explicitly simulate the time evolution of the plume rise with the additional mass and momentum. One-dimensional (1-D model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three dimensional (3-D Active Tracer High resolution Atmospheric Model (ATHAM. We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.

S. R. Freitas

2009-07-01

237

Structure-based design of novel Chlamydomonas reinhardtii D1-D2 photosynthetic proteins for herbicide monitoring.  

Science.gov (United States)

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

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

2009-10-01

238

Reexamination of the O(3P?1D) excitation rate by thermal electron impact  

International Nuclear Information System (INIS)

The theoretical and experimental electron impact excitation cross sections for the O(3P?1D) transition that have been reported in the literature the last two decades are used to derive O(3P?1D) excitation rates by thermal electron impact. The derived rates are represented by a simple parametric formula which should prove useful in atmospheric 6,300-angstrom airglow and electron gas thermal balance studies

239

Coherent Synchrotron Radiation and Space Charge for a 1-D Bunch on an Arbitrary Planar Orbit  

Energy Technology Data Exchange (ETDEWEB)

Realistic modeling of coherent synchrotron radiation (CSR) and the space charge force in single-pass systems and rings usually requires at least a two-dimensional (2-D) description of the charge/current density of the bunch. Since that leads to costly computations, one often resorts to a 1-D model of the bunch for first explorations. This paper provides several improvements to previous 1-D theories, eliminating unnecessary approximations and physical restrictions.

Warnock, R.L.; /SLAC

2008-01-08

240

Structural resistance of chemically modified 1-D nanostructured titanates in inorganic acid environment  

International Nuclear Information System (INIS)

Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO2-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO2-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO2-nanoproducts with different morphologies through a simple process and from a low cost precursor.

 
 
 
 
241

Amide analogues of CD1d agonists modulate iNKT-cell-mediated cytokine production.  

Science.gov (United States)

Invariant natural killer T (iNKT) cells are restricted by the non-polymorphic MHC class I-like protein, CD1d, and activated following presentation of lipid antigens bound to CD1d molecules. The prototypical iNKT cell agonist is ?-galactosyl ceramide (?-GalCer). CD1d-mediated activation of iNKT cells by this molecule results in the rapid secretion of a range of pro-inflammatory (Th1) and regulatory (Th2) cytokines. Polarization of the cytokine response can be achieved by modifying the structure of the glycolipid, which opens up the possibility of using CD1d agonists as therapeutic agents for a range of diseases. Analysis of crystal structures of the T-cell receptor-?-GalCer-CD1d complex led us to postulate that amide isosteres of known CD1d agonists should modulate the cytokine response profile upon iNKT-cell activation. To this end, we describe the synthesis and biological activity of amide analogues of ?-GalCer and its non-glycosidic analogue threitol ceramide (ThrCer). All of the analogues were found to stimulate murine and human iNKT cells by CD1d-mediated presentation to varying degrees; however, the thioamide and carbamate analogues of ThrCer were of particular interest in that they elicited a strongly polarized cytokine response (more interferon-gamma (IFN-?), no interleukin-4 (IL-4)) in mice. While the ThrCer-carbamate analogue was shown to transactivate natural killer (NK) cells, a mechanism that has been used to account for the preferential production of IFN-? by other CD1d agonists, this pathway does not account for the polarized cytokine response observed for the thioamide analogue. PMID:22324848

Wojno, Justyna; Jukes, John-Paul; Ghadbane, Hemza; Shepherd, Dawn; Besra, Gurdyal S; Cerundolo, Vincenzo; Cox, Liam R

2012-05-18

242

Structural resistance of chemically modified 1-D nanostructured titanates in inorganic acid environment  

Energy Technology Data Exchange (ETDEWEB)

Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO{sub 2}-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO{sub 2}-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO{sub 2}-nanoproducts with different morphologies through a simple process and from a low cost precursor.

Marinkovic, Bojan A., E-mail: bojan@puc-rio.br [Departamento de Engenharia de Materiais, Pontificia Universidade Catolica de Rio de Janeiro-PUC-Rio, Rua Marques de Sao Vicente 225, Gavea, RJ (Brazil); Fredholm, Yann C. [Nanogavea-Nanotecnologia Sustentavel Ltda, Av. Padre Leonel Franca 150, Gavea, RJ (Brazil); Morgado, Edisson [PETROBRAS S.A./CENPES, Research and Development Centre, Av. Horacio Macedo, 950, Cidade Universitaria, 21941-915, Rio de Janeiro, RJ (Brazil); Jardim, Paula M.; Rizzo, Fernando [Departamento de Engenharia de Materiais, Pontificia Universidade Catolica de Rio de Janeiro-PUC-Rio, Rua Marques de Sao Vicente 225, Gavea, RJ (Brazil)

2010-10-15

243

Q1D organic metals a theoretical determination of the electrical conductivity  

CERN Document Server

Using the Hubbard model on a 1D lattice and the "memory function" approach,we have calculated the electrical conductivity of a 1D system of correlated electrons on a lattice. We have determined the temperature and frequency profiles of the conductivity. Effects of changes of the band filling on the conductivity were also briefly discussed.The results were compared with experimental data on the Bechgaard salts, and the agreement is satisfactory.

Celebonovic, V

1997-01-01

244

Actinometric measurement of j(O3-O(1D)) using a luminol detector  

Science.gov (United States)

The photolysis frequency of ozone to singlet D oxygen atoms has been measured by means of a chemical actinometer using a luminol based detector. The instrument measures j(O3-O(1D)) with a precision of 10 percent. The data collected in winter and spring of 1991 is in agreement with model predictions and previously measured values. Data from a global solar radiometer can be used to estimate the effects of local cloudiness on j(O3-O(1D)).

Bairai, Solomon T.; Stedman, Donald H.

1992-01-01

245

Fluorine substitution enhanced photovoltaic performance of a D-A(1)-D-A(2) copolymer.  

Science.gov (United States)

A new alternating donor-acceptor (D-A1-D-A2) copolymer containing two electron-deficient moieties, isoindigo and quinoxaline, was synthesized. The photovoltaic performance of this polymer could be improved by incorporating fluorine atoms into the quinoxaline units, resulting in an efficiency of 6.32%. This result highlights the attractive promise of D-A1-D-A2 copolymers for high-performance bulk heterojunction solar cells. PMID:24000353

Dang, Dongfeng; Chen, Weichao; Yang, Renqiang; Zhu, Weiguo; Mammo, Wendimagegn; Wang, Ergang

2013-10-18

246

Spin-exchange-induced dimerization of an atomic 1-D system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Using low-temperature scanning tunneling microscopy, we demonstrate an unambiguous 1-D system that surprisingly undergoes a CDW instability on a metallic substrate. Our ability to directly and quantitatively measure the structural distortion of this system provides an accurate reference for comparison with first principles theory. In comparison to previously proposed physical mechanisms, we attribute this particular 1-D CDW instability to a ferromagnetic state. We show that ...

Zaki, Nader; Marianetti, Chris A.; Acharya, Danda P.; Zahl, Percy; Sutter, Peter; Okamoto, Junichi; Johnson, Peter D.; Millis, Andrew J.; Osgood, Richard M.

2012-01-01

247

Simplexide Induces CD1d-Dependent Cytokine and Chemokine Production from Human Monocytes.  

Science.gov (United States)

Monocytes are major effector cells of innate immunity and recognize several endogenous and exogenous molecules due to the expression of wide spectrum of receptors. Among them, the MHC class I-like molecule CD1d interacts with glycolipids and presents them to iNKT cells, mediating their activation. Simplexide belongs to a novel class of glycolipids isolated from marine sponges and is structurally distinct from other immunologically active glycolipids. In this study we have examined the effects of simplexide on cytokine and chemokine release from human monocytes. Simplexide induces a concentration- and time-dependent release of IL-6, CXCL8, TNF-? and IL-10 and increases the expression of IL6, CXCL8 and IL10 mRNA. Cytokine and chemokine release induced by simplexide from monocytes is dependent on CD1d since: i) a CD1d antagonist, 1,2-bis (diphenylphosphino) ethane [DPPE]- polyethylene glycolmonomethylether [PEG], specifically blocks simplexide-induced activation of monocytes; ii) CD1d knockdown inhibits monocyte activation by simplexide and iii) simplexide induces cytokine production from CD1d-transfected but not parental C1R cell line Finally, we have shown that simplexide also induces iNKT cell expansion in vitro. Our results demonstrate that simplexide, apart from activating iNKT cells, induces the production of cytokines and chemokines from human monocytes by direct interaction with CD1d. PMID:25390653

Loffredo, Stefania; Staiano, Rosaria I; Granata, Francescopaolo; Costantino, Valeria; Borriello, Francesco; Frattini, Annunziata; Lepore, Maria Teresa; Mangoni, Alfonso; Marone, Gianni; Triggiani, Massimo

2014-01-01

248

Simplexide Induces CD1d-Dependent Cytokine and Chemokine Production from Human Monocytes  

Science.gov (United States)

Monocytes are major effector cells of innate immunity and recognize several endogenous and exogenous molecules due to the expression of wide spectrum of receptors. Among them, the MHC class I-like molecule CD1d interacts with glycolipids and presents them to iNKT cells, mediating their activation. Simplexide belongs to a novel class of glycolipids isolated from marine sponges and is structurally distinct from other immunologically active glycolipids. In this study we have examined the effects of simplexide on cytokine and chemokine release from human monocytes. Simplexide induces a concentration- and time-dependent release of IL-6, CXCL8, TNF-? and IL-10 and increases the expression of IL6, CXCL8 and IL10 mRNA. Cytokine and chemokine release induced by simplexide from monocytes is dependent on CD1d since: i) a CD1d antagonist, 1,2-bis (diphenylphosphino) ethane [DPPE]- polyethylene glycolmonomethylether [PEG], specifically blocks simplexide-induced activation of monocytes; ii) CD1d knockdown inhibits monocyte activation by simplexide and iii) simplexide induces cytokine production from CD1d-transfected but not parental C1R cell line Finally, we have shown that simplexide also induces iNKT cell expansion in vitro. Our results demonstrate that simplexide, apart from activating iNKT cells, induces the production of cytokines and chemokines from human monocytes by direct interaction with CD1d. PMID:25390653

Loffredo, Stefania; Staiano, Rosaria I.; Granata, Francescopaolo; Costantino, Valeria; Borriello, Francesco; Frattini, Annunziata; Lepore, Maria Teresa; Mangoni, Alfonso; Marone, Gianni; Triggiani, Massimo

2014-01-01

249

Evaluation of the entropy consistent euler flux on 1D and 2D test problems  

Science.gov (United States)

Perhaps most CFD simulations may yield good predictions of pressure and velocity when compared to experimental data. Unfortunately, these results will most likely not adhere to the second law of thermodynamics hence comprising the authenticity of predicted data. Currently, the test of a good CFD code is to check how much entropy is generated in a smooth flow and hope that the numerical entropy produced is of the correct sign when a shock is encountered. Herein, a shock capturing code written in C++ based on a recent entropy consistent Euler flux is developed to simulate 1D and 2D flows. Unlike other finite volume schemes in commercial CFD code, this entropy consistent flux (EC) function precisely satisfies the discrete second law of thermodynamics. This EC flux has an entropy-conserved part, preserving entropy for smooth flows and a numerical diffusion part that will accurately produce the proper amount of entropy, consistent with the second law. Several numerical simulations of the entropy consistent flux have been tested on two dimensional test cases. The first case is a Mach 3 flow over a forward facing step. The second case is a flow over a NACA 0012 airfoil while the third case is a hypersonic flow passing over a 2D cylinder. Local flow quantities such as velocity and pressure are analyzed and then compared with mainly the Roe flux. The results herein show that the EC flux does not capture the unphysical rarefaction shock unlike the Roe-flux and does not easily succumb to the carbuncle phenomenon. In addition, the EC flux maintains good performance in cases where the Roe flux is known to be superior.

Roslan, Nur Khairunnisa Hanisah; Ismail, Farzad

2012-06-01

250

The relation of scan range and reflection shape in single-crystal 1D profile measurement  

International Nuclear Information System (INIS)

Changes in shape of 1D profiles of small-single-crystal Bragg reflections have been examined in terms of the shapes of the components which, convoluted together, generate the profile. In most practical cases, operational features require truncation of the angular scan range of measurement and the conventional linear formula for scan range, ?=a+bxtan ?, is then not strictly valid. A more appropriate relationship involves a combination of root mean square (RMS) and linear (LIN) forms, ?=[(p')2+(q'xtan ?2]1/2 + (p''+q''xtan ?) where p' is associated with the leading and trailing edges of the distribution of the combined ?-invariant components and p'' with its plateau width while q' is associated with the leading and trailing edges of the distribution of the wavelength component and q'' with the separation of its outer peaks if there are more than one. For operational purposes, this relationship can be substituted with adequate precision by ?=[c2+(dxtan ?)2]1/2, but the parameters c and d do not then have a simple relationship to the ?-invariant and ?-variant components. Use of a conventional linear formula when a RMS one is the relevant one can mean that, in the lower ? range, the estimate of integrated intensity will be too high and, in the higher ? range, it will be too low, so that, with increasing ?, a positive then a negative systematic error is introduced and not merely a negative error not merely a negative error as the conventional interpretation of truncation holds. The conclusions of the present analysis are tested against experimental data where the conventional treatment for truncation failed. For the estimation of integrated intensity, and hence of structure factors, which are consistent over the operational range of ?, a RMS formula for the scan range is advisable. (orig.)

251

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 (), RuCl2(D-P2)2 (), RuCl2(D-P3)2 (), or RuCl2(D-P4)2 (), respectively, are formed. Similarly, treatment of OsCl2(PPh3)3 with D-P1 gives OsCl2(D-P1)2 (). The single crystal X-ray structure determination of reveals that each D-P1 ligand coordinates to ruthenium through phosphorus and the oxygen atom of the methoxyl group. Treatment of with excess LiBr or LiI results in metathesis of the chloride ligands and RuBr2(D-P1)2 () or RuI2(D-P1)2 (), respectively, are formed. Exposure of a solution of to carbon monoxide results in the very rapid formation of RuCl2(CO)2(D-P1)2 (), 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 . Preliminary studies indicate that 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

2014-10-28

252

O2(b^1 ? _g^ +, ? = 0, 1) relative yields in O(1D) + O2 energy transfer  

Science.gov (United States)

Energy transfer from O(1D) to O2 is the main source of O2(b^1 ? _g^ +) in vibrational levels ? = 0 and 1 in the Earth's thermosphere. Knowledge of the relative yields for O2(b^1 ? _g^ +) production in ? = 0 and 1 is essential for a reliable interpretation and modeling of the O2 atmospheric band emissions (b^1 ? _g^ +-X ^3 ? _g^ -) from these two vibrational levels. We report laboratory measurements of the relative yields at room temperature. In the experiments, O2(b^1 ? _g^ +, ? = 0, 1) is generated by O(1D) + O2 collisions following partial photodissociation of O2 at 157.6 nm. O2(b^1 ? _g^ +, ? = 0, 1) emission detection is used to monitor the temporal evolution of the vibrational level populations. The measured fractional yield for ? = 1 is 0.8 ± 0.1, in contrast with the results of previous studies that indicated dominant O2(b^1 ? _g^ +, ? = 0) production. A revision is warranted of the values used for these relative yields in atmospheric models.

Pejakovi?, Dušan A.; Copeland, Richard A.; Slanger, Tom G.; Kalogerakis, Konstantinos S.

2014-07-01

253

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

254

HERMES Precision Results on g1p, g1d and g1n and the First Measurement of the Tensor Structure Function b1d  

CERN Document Server

Final HERMES results on the proton, deuteron and neutron structure function g1 are presented in the kinematic range 0.00211d are presented.

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

2005-01-01

255

Kinetics of O(1D) + H2O and O(1D) + H2: absolute rate coefficients and O(3P) yields between 227 and 453 K.  

Science.gov (United States)

The rate coefficients for the crucial atmospheric reactions of O((1)D) with H(2)O and H(2), k(1) and k(2), were measured over a wide temperature range using O((1)D) detection based on the chemiluminescence reaction of O((1)D) with C(2)H. Analyzing the decays of the chemiluminescence intensities yielded a value for k(1)(T) of (1.70 x 10(-10)exp[36 K/T]) cm(3) s(-1). Multiplying or dividing k(1)(T) by a factor f(T) = 1.04 exp(5.59(|1 K/T- 1/287|)), gives the 95% confidence limits; our new determination, in good agreement with previous studies, further reduces the uncertainty in k(1). An extended study of k(2) yielded a temperature independent rate constant of (1.35 +/- 0.05) x 10(-10) cm(3) s(-1). This precise value, based on an extended set of determinations with very low scatter, is significantly larger than the current recommendations, as were two other recent k(2) determinations. Secondly, the fractions of O((1)D) quenched to O((3)P) by H(2)O and H(2), k(1b)/k(1) and k(2b)/k(2), were precisely determined from fits to chemiluminescence decays. A temperature-independent value for k(1b)/k(1) of 0.010 +/- 0.003 was found. For the quenching fraction k(2b)/k(2) a value of 0.007 +/- 0.007 was obtained at room temperature. Both determinations are significantly smaller than values and upper limits from previous studies. PMID:20577663

Vranckx, Stijn; Peeters, Jozef; Carl, Shaun

2010-08-28

256

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

Energy Technology Data Exchange (ETDEWEB)

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

Miller, D S

2000-08-21

257

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

International Nuclear Information System (INIS)

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

258

Force on a slow moving impurity due to thermal and quantum fluctuations in a 1D Bose-Einstein condensate  

Energy Technology Data Exchange (ETDEWEB)

We study the drag force acting on an impurity moving through a 1D Bose-Einstein condensate in the presence of both quantum and thermal fluctuations. We are able to find exact analytical solutions of the partial differential equations to the level of the Bogoliubov approximation. At zero temperature, we find a nonzero force is exerted on the impurity at subcritical velocities, due to the scattering of quantum fluctuations. We make the following explicit assumptions: far from the impurity the system is in a quantum state given by that of a zero (or finite) temperature Bose-Einstein condensate, and the scattering process generates only causally related reflection/transmission. The results raise unanswered questions in the quantum dynamics associated with the formation of persistent currents.

Roberts, David [Los Alamos National Laboratory; Sykes, Andrew [UNIV OF QUEENSLAND

2009-01-01

259

50 CFR Table 1d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2011 and 2012.  

Science.gov (United States)

...Fisheries 9 2010-10-01 2010-10-01 false At-Sea Whiting Fishery Annual Set-Asides, 2011 and 2012. 1d Table...Table 1d Table 1d to Part 660, Subpart C— At-Sea Whiting Fishery Annual Set-Asides, 2011 and 2012....

2010-10-01

260

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.

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

2014-02-01

 
 
 
 
261

Microstates of D1-D5(-P) black holes as interacting D-branes  

CERN Document Server

In our previous study [1] (1311.6540), we figured out that the thermodynamics of the near extremal black $p$-branes can be explained as the collective motions of gravitationally interacting elementary $p$-branes (the $p$-soup proposal). We test this proposal in the near-extremal D1-D5 and D1-D5-P black holes and show that their thermodynamics also can be explained in a similar fashion, i.e. via the collective motions of the interacting elementary D1-branes and D5-branes (and waves). It may imply that the microscopic origins of these intersecting black branes and the black $p$-brane are explained in the unified picture. We also argue the relation between the $p$-soup proposal and the conformal field theory calculations of the D1-D5(-P) black holes in superstring theory.

Morita, Takeshi

2014-01-01

262

U-duality Twists and Possible Phase Transitions in 2+1D Supergravity  

CERN Document Server

We study 2+1D toroidal compactifications of M-theory with twists in the U-duality group. These compactifications realize many symmetric-manifolds from the classification of 2+1D extended supergravity moduli-spaces. We then focus on the moduli-space $SU(2,1)/U(2)$ obtained by dimensional reduction of pure N=2 supergravity in 3+1D. This space is realized with an explicit example. Assuming that there are no quantum corrections, we conjecture that the classical discrete duality group has to be augmented with an extra strong/weak coupling duality. This implies the existence of new phases of the theory in which the original 8 compactification radii are all fixed at the Planck scale.

Ganor, O J

1999-01-01

263

An improved 1D area law for frustration-free systems  

CERN Document Server

We present a new proof for the 1D area law for frustration-free systems with a constant gap, which exponentially improves the entropy bound in Hastings' 1D area law, and which is tight to within a polynomial factor. For particles of dimension $d$, spectral gap $\\epsilon>0$ and interaction strength of at most $J$, our entropy bound is $S_{1D}\\le \\orderof{1}X^3\\log^8 X$ where $X\\EqDef(J\\log d)/\\epsilon$. Our proof is completely combinatorial, combining the detectability lemma with basic tools from approximation theory. Incorporating locality into the proof when applied to the 2D case gives an entanglement bound that is at the cusp of being non-trivial in the sense that any further improvement would yield a sub-volume law.

Arad, Itai; Vazirani, Umesh

2011-01-01

264

The deuteron spin-dependent structure function g1d and its first moment  

Science.gov (United States)

We present a measurement of the deuteron spin-dependent structure function g1d based on the data collected by the COMPASS experiment at CERN during the years 2002 2004. The data provide an accurate evaluation for ?1d, the first moment of g1d(x), and for the matrix element of the singlet axial current, a. The results of QCD fits in the next to leading order (NLO) on all g deep inelastic scattering data are also presented. They provide two solutions with the gluon spin distribution function ?G positive or negative, which describe the data equally well. In both cases, at Q=3GeV the first moment of ?G(x) is found to be of the order of 0.2 0.3 in absolute value.

Compass Collaboration; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Alexeev, M.; Amoroso, A.; Bade?ek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Becker, M.; Bedfer, Y.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M. P.; Bytchkov, V. N.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Colavita, A. A.; Costa, S.; Crespo, M. L.; D'Hose, N.; Dalla Torre, S.; Das, S.; Dasgupta, S. S.; de Masi, R.; Dedek, N.; Demchenko, D.; Denisov, O. Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A. M.; Donskov, S. V.; Dorofeev, V. A.; Doshita, N.; Duic, V.; Dünnweber, W.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Fauland, P.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M.; Fischer, H.; Franz, J.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A. M.; Grajek, O. A.; Grasso, A.; Grube, B.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Hedicke, S.; Heinsius, F. H.; Hermann, R.; Heß, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Horn, I.; Ilgner, C.; Ioukaev, A. I.; Ivanchin, I.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N. I.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J. H.; Kolosov, V. N.; Komissarov, E. V.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Korentchenko, A. S.; Korzenev, A.; Kotzinian, A. M.; Koutchinski, N. A.; Kouznetsov, O.; Kowalik, K.; Kramer, D.; Kravchuk, N. P.; Krivokhizhin, G. V.; Kroumchtein, Z. V.; Kubart, J.; Kuhn, R.; Kukhtin, V.; Kunne, F.; Kurek, K.; Ladygin, M. E.; Lamanna, M.; Le Goff, J. M.; Leberig, M.; Lednev, A. A.; Lehmann, A.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Masek, L.; Massmann, F.; Matsuda, T.; Matthiä, D.; Maximov, A. N.; Meyer, W.; Mielech, A.; Mikhailov, Yu. V.; Moinester, M. A.; Nagel, T.; Nähle, O.; Nassalski, J.; Neliba, S.; Neyret, D. P.; Nikolaenko, V. I.; Nikolaev, K.; Nozdrin, A. A.; Obraztsov, V. F.; Olshevsky, A. G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Peshekhonov, D. V.; Peshekhonov, V. D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V. A.; Pontecorvo, G.; Popov, A. A.; Pretz, J.; Procureur, S.; Quintans, C.; Ramos, S.; Reicherz, G.; Rondio, E.; Rozhdestvensky, A. M.; Ryabchikov, D.; Samoylenko, V. D.; Sandacz, A.; Santos, H.; Sapozhnikov, M. G.; Savin, I. A.; Schiavon, P.; Schill, C.; Schmitt, L.; Schroeder, W.; Seeharsch, D.; Seimetz, M.; Setter, D.; Shevchenko, O. Yu.; Siebert, H.-W.; Silva, L.; Sinha, L.; Sissakian, A. N.; Slunecka, M.; Smirnov, G. I.; Sozzi, F.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sugonyaev, V. P.; Sulc, M.; Sulej, R.; Tchalishev, V. V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L. G.; Trippel, S.; Venugopal, G.; Virius, M.; Vlassov, N. V.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wi?licki, W.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhao, J.; Ziegler, R.; Zvyagin, A.

2007-03-01

265

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

266

Enhancing the optical nonlinearity by 1D thin-film photonic crystals with Kerr defect cavities  

Science.gov (United States)

In this paper, we study the linear and nonlinear responses of 1-D photonic bandgap (PBG) structures. We show that, the nonlinear interaction can be greatly enhanced by the use of Kerr defect modes in a 1D dielectric photonic crystal structure, such as low-intensity bistability and multistability, and by optimizing the design of the layer sequence. 1-D PBG structure can also be promising candidate as low-intensity nonlinear phase shifter. Nonlinear z-scan measurements of a 3-cavity thin-film PBG sample show that the nonlinearity is enhanced over the native material by a factor over 30, while maintaining a bandwidth greater than 1T Hz, which is great for all-optical switching.

Chen, Yan; Liu, Yongdong; Blair, Steve

2005-04-01

267

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

268

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 (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

269

Epitaxial integrated dE1 - dE2 silicon detectors  

International Nuclear Information System (INIS)

Epitaxial integrated dE1-dE2 silicon detectors have been developed by using the multilayer epitaxial crystal growth technique combined with the chemical preferential etching technique. These detectors are useful for eliminating events affected by channeling and blocking effects in the identification of heavy ions using multiple detector telescope systems. Characteristics of dE detectors of the integrated dE1-dE2 type are confirmed to as good as those of integrated E-dE detectors. (orig.)

270

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

271

The 1/D Expansion for Classical Magnets: Low-Dimensional Models with Magnetic Field  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The field-dependent magnetization m(H,T) of 1- and 2-dimensional classical magnets described by the $D$-component vector model is calculated analytically in the whole range of temperature and magnetic fields with the help of the 1/D expansion. In the 1-st order in 1/D the theory reproduces with a good accuracy the temperature dependence of the zero-field susceptibility of antiferromagnets \\chi with the maximum at T \\lsim |J_0|/D (J_0 is the Fourier component of the exchange ...

Garanin, D. A.

1998-01-01

272

Excitation content of spectral functions in the 1D t-J model  

International Nuclear Information System (INIS)

The excitation content of spectral functions of the 1D t-J model with nearest neighbor (n.n.) interactions is obtained from the Bethe-Ansatz solution at the supersymmetric point and compared with quantum Monte Carlo (QMC) simulations based on the hybrid-loop algorithm. We consider the one-particle spectrum as well as the dynamical spin and charge structure factors. The connection to the 1D supersymmetric t-J model with 1/r2 interaction will be explained

273

Excitation content of spectral functions in the 1D t-J model  

Energy Technology Data Exchange (ETDEWEB)

The excitation content of spectral functions of the 1D t-J model with nearest neighbor (n.n.) interactions is obtained from the Bethe-Ansatz solution at the supersymmetric point and compared with quantum Monte Carlo (QMC) simulations based on the hybrid-loop algorithm. We consider the one-particle spectrum as well as the dynamical spin and charge structure factors. The connection to the 1D supersymmetric t-J model with 1/r{sup 2} interaction will be explained.

Lavalle, Catia [Institut fuer Theoretische Physik III, Universitaet Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)], E-mail: lavalle@theo3.physik.uni-stuttgart.de; Arikawa, Mitsuhiro [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Muramatsu, Alejandro [Institut fuer Theoretische Physik III, Universitaet Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart (Germany)

2007-09-01

274

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)

275

Accurate baryon masses from meson masses using potential models and the 1/D expansion  

International Nuclear Information System (INIS)

The recently derived ratio of three particle to two particle nonrelativistic binding energies for power law potentials in the leading order of the 1/D expansion, where D is the number of spatial dimensions, is used to investigate the ground state baryon spectrum. Using the phenomenologically successful Martin potential and the known meson masses, it is shown how the above ratio can be utilized to obtain accurate masses for baryons, even those containing light quarks. It is also mentioned how the shifted 1/D expansion may be used to study certain excited baryon states

276

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

CERN Document Server

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 deconfined quantum criticality, but remains linearly confining. Deconfinement only sets in at high temperature.

Banerjee, D; Widmer, P; Wiese, U -J

2013-01-01

277

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

278

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

279

Conformal Generators and Doubly Special Relativity Theories  

CERN Document Server

In this paper, the relation between the modified Lorenz boosts, proposed in the doubly relativity theories and a linear combination of Conformal Group generators in $R^{1,d-1}$ is investigated. The introduction of a new generator is proposed in order to deform the Conformal Group to achieve the connection conjectured. The new generator is obtained trough a formal dimensional reduction from a free massless particle living in a $R^{2,d}$ space. Due this treatment it is possible to say that even DSR theories modify light cone structure in $R^{1,d-1}$, it could remains, in some cases, untouched in $R^{2,d}$.

Leiva, C

2004-01-01

280

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

 
 
 
 
281

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

282

Phase structure of (2+1)d strongly coupled lattice gauge theories  

CERN Document Server

We study the chiral phase transition in (2+1)d strongly coupled U(N) lattice gauge theories with staggered fermions. We show with high precision simulations performed directly in the chiral limit that these models undergo a Berezinski-Kosterlitz-Thouless (BKT) transition. We also show that this universality class is unaffected even in the large N limit.

Strouthos, C G

2003-01-01

283

A simple 1D model with thermomechanical coupling for superelastic SMAs  

International Nuclear Information System (INIS)

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

284

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

International Nuclear Information System (INIS)

The Atiyah-Bott-Shapiro classification of the irreducible Clifford algebra is used to derive general properties of the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z2-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. (author)

285

Reduction of the electronics of a 1D position sensitive detector  

International Nuclear Information System (INIS)

A readout method has been developed for a 1D position sensitive detector which reduces the readout electronics dramatically. The method combines features of both cathode-strip and cathode-wedge readout and has been applied to a 36-strip detector. The detector electronics is reduced to 8 charge amplifiers without loss of spatial resolution. (orig.)

286

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

CERN Document Server

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

Gu, Xumin

2011-01-01

287

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

Science.gov (United States)

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

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

2010-12-01

288

Pharmacological challenge with a serotonin 1D agonist in alcohol dependence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Pienaar Willie; Stefan, Maritz J.; Hugo Charmaine J; Vythilingum Bavanisha; Stein Dan J

2005-01-01

289

Effective potential in N=1, d=4 supergravity coupled to the Volkov-Akulov field  

International Nuclear Information System (INIS)

The only-loop effective potential for N=1, d=4 supergravity theory coupled to the Volkov-Akulov field is calculated. Then it is shown that after an ajustment of some parameters the local supersymmetry is dynamically broken and as a consequence the gravitino acquires mass. (Author)

290

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

291

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

292

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

293

X-ray photon correlation spectroscopy using the Mythen 1D detector  

International Nuclear Information System (INIS)

X-ray Photon Correlation Spectroscopy (XPCS) is an experimental technique to measure the dynamics of materials on nano- and microscales. Often, the maximum frame rate of the detector limits which dynamical processes can be investigated. This study examines the applicability of the Mythen 1D detector for coherent scattering applications with special focus on XPCS experiments.

294

Exact Embedding of N=1, D=7 Gauged Supergravity in D=11  

CERN Document Server

We obtain the explicit and complete bosonic non-linear Kaluza-Klein ansatz for the consistent S^4 reduction of D=11 supergravity to N=1, D=7 gauged supergravity. This provides a geometrical interpretation of the lower dimensional solutions from the eleven-dimensional point of view.

Lü, H

1999-01-01

295

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

Science.gov (United States)

Ciliates are a major evolutionary lineage within the alveolates, which are distributed in nearly all habitats on our planet and are an essential component for ecosystem function, processes and stability. Accurate identification of these unicellular eukaryotes through, for example, microscopy or mating type reactions is reserved to few specialists. To satisfy the demand for a DNA barcode for ciliates, which meets the standard criteria for DNA barcodes defined by the Consortium for the Barcode of Life (CBOL), we here evaluated the D1-D2 region of the ribosomal DNA large subunit (LSU-rDNA). Primer universality for the phylum Ciliophora was tested in silico with available database sequences as well as in the laboratory with 73 ciliate species, which represented nine of 12 ciliate classes. Primers tested in this study were successful for all tested classes. To test the ability of the D1-D2 region to resolve conspecific and congeneric sequence divergence, 63 Paramecium strains were sampled from 24 mating species. The average conspecific D1-D2 variation was 0.18%, whereas congeneric sequence divergence averaged 4.83%. In pairwise genetic distance analyses, we identified a D1-D2 sequence divergence of Paramecium species. Using this definition, only 3.8% of all conspecific and 3.9% of all congeneric sequence comparisons had the potential of false assignments. Neighbour-joining analyses inferred monophyly for all taxa but for two Paramecium octaurelia strains. Here, we present a protocol for easy DNA amplification of single cells and voucher deposition. In conclusion, the presented data pinpoint the D1-D2 region as an excellent candidate for an official CBOL barcode for ciliated protists. PMID:24165195

Stoeck, T; Przybos, E; Dunthorn, M

2014-05-01

296

POLARISATION OF THE S - PHASE OF SEISMOGRAMS  

Directory of Open Access Journals (Sweden)

Full Text Available In earthquakes recorded at moderate distances it lias been ohservedthat S phase appears first as SII, folloived some 10 to 14 seconds laterby SV. The object of tliis paper is to try to decide ichether doublérefraction is likely to be the explanation of tliis jìlwnomenon.A simpie model to consider ivould be a « transversely isotropie »material, symmetrical about the radiai direction. Formulae for thevelocities of SII and SV waves are available; tliese velocities dependon the angle that the ray makes ivi t li the norma!. It is unlikely thatthe Eartli could be as markedly anisotropie as the minerai beryl, whichis transversely isotropie; aceordingly, this material, of ivhich the fi veclastic constants are knoivn is taken as an extreme example, andthe velocities of SH and SV for different angles of incidence are« scaled down » so as to match the velocity of distortional ivaves ingranite. It is then possible to calcitiate the difference in the timo takenby ivaves from one point of the surface of the Earth to anotlier pointon the surface according as the S wave in the surface layer is of SHor SV type.

R. STONELEY

1951-06-01

297

How Do I Read a Seismogram?  

Science.gov (United States)

This tutorial introduces novice users to reading the lines on a seismograph. Topics include how to distinguish a real earthquake from background vibrations (microseisms) recorded by the instrument, how to read the minute marks that record the passage of time, and how to distinguish the types of earthquake waves that appear on the chart.

298

Saturn Ring Seismology: Interpreting the Seismogram  

Science.gov (United States)

Marley (1990) and Marley and Porco (1993) proposed that f-mode oscillations of Saturn could excite resonant density and bending waves in the inner C-ring. They hypothesized that certain wave features discovered by Rosen et al. (1991) that were not associated with known satellite resonances could be the result of such resonant interactions with the planetary oscillation modes. They also predicted that if this was the case the waves would be found to be density (and not bending) waves by Cassini and predicted the azimuthal wave number of the C-ring waves m. Employing Cassini VIMS stellar occultation data Hedman and Nicholson (2013) have now confirmed the predictions and demonstrated that at least some of the C-ring features identified by Rosen et al. are indeed likely caused by resonant oscillation modes of Saturn. Given this context we have taken a fresh look at the Saturn ring seismology. First we propose that an apparent bending wave denoted 'j' by Rosen may be a second order outer vertical resonance with the l=3, m=2 f-mode of Saturn and discuss the locations of other plausible second order resonances in the rings. Since only a handful of ring resonances have been identified, measuring even one or two additional planetary mode frequencies would substantially assist the process of inverting mode frequencies to constrain Saturn interior's structure. Using the available mode frequencies, modern inversion technique employed in stellar seismology, and a recent set of Saturn interior models we provide an initial estimation of what available mode frequencies are telling us about the interior structure of the planet. Since the f-modes are confined relatively closely to the planetary surface, most of the observed modes probe only the outermost layers of the planet that are already comparatively well understood. However the l = 2 mode does probe relatively deeply into the planet and we will discuss the potential the measurement of this mode frequency has for placing new constraints on the interior structure.

Marley, Mark Scott

2013-01-01

299

Linear and Nonlinear Laser-Based Guided Acoustic Waves Propagating at Surfaces (2D) and Edges (1D)  

Science.gov (United States)

In recent years photoacoustics opened the door to many new applications of 2D linear surface acoustic waves (SAWs), e.g., nondestructive evaluation (NDE) of surface-breaking cracks. Real partially-closed cracks of micrometer size have been analyzed. More recently also pulsed laser excitation of solitary elastic surface pulses and their detection with a continuouswave probe laser has been achieved, by generating dispersion with a thin film coating that introduces a length scale. In addition, such laser-based pump-probe experiments allow the excitation of short nonlinear SAW pulses developing steep shock fronts that fracture brittle materials such as silica or silicon. With this method it is possible to measure the fracture strength of materials and compare the critical failure stress with ab initio calculations of the ideal strength of the corresponding perfect single crystal. The excitation and detection of 1D edge or wedge waves propagating along a wedge formed by two planar surfaces that meet at the apex of the wedge or wedge tip has been performed by laser irradiation. The characteristic features of the non-dispersive linear wedge waves such as their small phase velocity below the Rayleigh velocity, the very high degree of localization of the displacement field at the wedge tip, and their existence for certain geometries in anisotropic media such as silicon could be verified by photoacoustic experiments. Despite the strong nonlinearity of certain edge-localized modes, as expected from theoretical considerations, 1D solitary waves and nonlinear wedge waves with steep pulse profiles could not be detected up to now. The latest progress will be discussed.

Hess, Peter

2012-02-01

300

Targeting PPM1D by lentivirus-mediated RNA interference inhibits the tumorigenicity of bladder cancer cells  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Protein phosphatase magnesium/manganese-dependent 1D (PPM1D) is a p53-induced phosphatase that functions as a negative regulator of stress response pathways and has oncogenic properties. However, the functional role of PPM1D in bladder cancer (BC) remains largely unknown. In the present study, lenti [...] virus vectors carrying small hairpin RNA (shRNA) targeting PPM1D were used to explore the effects of PPM1D knockdown on BC cell proliferation and tumorigenesis. shRNA-mediated knockdown of PPM1D significantly inhibited cell growth and colony forming ability in the BC cell lines 5637 and T24. Flow cytometric analysis showed that PPM1D silencing increased the proportion of cells in the G0/G1 phase. Downregulation of PPM1D also inhibited 5637 cell tumorigenicity in nude mice. The results of the present study suggest that PPM1D plays a potentially important role in BC tumorigenicity, and lentivirus-mediated delivery of shRNA against PPM1D might be a promising therapeutic strategy for the treatment of BC.

W., Wang; H., Zhu; H., Zhang; L., Zhang; Q., Ding; H., Jiang.

1044-10-01

 
 
 
 
301

Targeting PPM1D by lentivirus-mediated RNA interference inhibits the tumorigenicity of bladder cancer cells  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Protein phosphatase magnesium/manganese-dependent 1D (PPM1D) is a p53-induced phosphatase that functions as a negative regulator of stress response pathways and has oncogenic properties. However, the functional role of PPM1D in bladder cancer (BC) remains largely unknown. In the present study, lenti [...] virus vectors carrying small hairpin RNA (shRNA) targeting PPM1D were used to explore the effects of PPM1D knockdown on BC cell proliferation and tumorigenesis. shRNA-mediated knockdown of PPM1D significantly inhibited cell growth and colony forming ability in the BC cell lines 5637 and T24. Flow cytometric analysis showed that PPM1D silencing increased the proportion of cells in the G0/G1 phase. Downregulation of PPM1D also inhibited 5637 cell tumorigenicity in nude mice. The results of the present study suggest that PPM1D plays a potentially important role in BC tumorigenicity, and lentivirus-mediated delivery of shRNA against PPM1D might be a promising therapeutic strategy for the treatment of BC.

W., Wang; H., Zhu; H., Zhang; L., Zhang; Q., Ding; H., Jiang.

2014-09-23

302

Targeting PPM1D by lentivirus-mediated RNA interference inhibits the tumorigenicity of bladder cancer cells  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Protein phosphatase magnesium/manganese-dependent 1D (PPM1D) is a p53-induced phosphatase that functions as a negative regulator of stress response pathways and has oncogenic properties. However, the functional role of PPM1D in bladder cancer (BC) remains largely unknown. In the present study, lenti [...] virus vectors carrying small hairpin RNA (shRNA) targeting PPM1D were used to explore the effects of PPM1D knockdown on BC cell proliferation and tumorigenesis. shRNA-mediated knockdown of PPM1D significantly inhibited cell growth and colony forming ability in the BC cell lines 5637 and T24. Flow cytometric analysis showed that PPM1D silencing increased the proportion of cells in the G0/G1 phase. Downregulation of PPM1D also inhibited 5637 cell tumorigenicity in nude mice. The results of the present study suggest that PPM1D plays a potentially important role in BC tumorigenicity, and lentivirus-mediated delivery of shRNA against PPM1D might be a promising therapeutic strategy for the treatment of BC.

W., Wang; H., Zhu; H., Zhang; L., Zhang; Q., Ding; H., Jiang.

303

Targeting PPM1D by lentivirus-mediated RNA interference inhibits the tumorigenicity of bladder cancer cells.  

Science.gov (United States)

Protein phosphatase magnesium/manganese-dependent 1D (PPM1D) is a p53-induced phosphatase that functions as a negative regulator of stress response pathways and has oncogenic properties. However, the functional role of PPM1D in bladder cancer (BC) remains largely unknown. In the present study, lentivirus vectors carrying small hairpin RNA (shRNA) targeting PPM1D were used to explore the effects of PPM1D knockdown on BC cell proliferation and tumorigenesis. shRNA-mediated knockdown of PPM1D significantly inhibited cell growth and colony forming ability in the BC cell lines 5637 and T24. Flow cytometric analysis showed that PPM1D silencing increased the proportion of cells in the G0/G1 phase. Downregulation of PPM1D also inhibited 5637 cell tumorigenicity in nude mice. The results of the present study suggest that PPM1D plays a potentially important role in BC tumorigenicity, and lentivirus-mediated delivery of shRNA against PPM1D might be a promising therapeutic strategy for the treatment of BC. PMID:25387670

Wang, W; Zhu, H; Zhang, H; Zhang, L; Ding, Q; Jiang, H

2014-12-01

304

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

305

Constructions of 1D helical chains with left-handed/right-handed helicity: a correlation between the helicity of 1D chains and the chirality of building blocks.  

Science.gov (United States)

The reactions of [Ni(alpha-SS-L)](ClO(4))(2)/[Ni(alpha-RR-L)](ClO(4))(2) with dca(-) gave two enantiomers of [Ni(SS-L)](dca)(2) (S-) and [Ni(RR-L)](dca)(2) (R-) in acetonitrile/water, and two supramolecular stereoisomers of {[Ni(SS-L)](2)(dca)(3)(ClO(4)).DMF}(n) (Delta-) and {[Ni(RR-L)](2)(dca)(3)(ClO(4)).DMF}(n) (Lambda-) in acetonitrile/DMF, respectively (L = 5,5,7,12,12, 14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, dca = dicyanamide, N(CN)(2)(-)). While the reaction of racemic [Ni(alpha-rac-L)](ClO(4))(2) (containing an equal amount of SS and RR enantiomers) with dca(-) in acetonitrile/water or acetonitrile/DMF produced a trimer of [Ni(rac-L)(dca)](3).(dca).(ClO(4))(2).MeCN () rather than S-/R- or Delta-/Lambda-. X-ray single-crystal analysis reveals that S-/R- and Delta-/Lambda- crystallize in a chiral space group P2(1), while crystallizes in a centrosymmetric space group C2/c. In S-/R-, the [Ni(SS-L)](dca)(2)/[Ni(RR-L)](dca)(2) monomers are linked through intermolecular hydrogen bonds to form a two-dimensional sheet. While the intermolecular hydrogen bonding linking of {[Ni(SS-L)](2)(dca)(3)}(+)/{[Ni(RR-L)](2)(dca)(3)}(+) leads to the formation of a 1D right-handed helical chain of Delta- and 1D left-handed helical chain of Lambda-, respectively, demonstrating there is a correlation between the helicity of 1D chains and the chirality of building blocks. Complex forms a triangular structure of {[Ni(rac-L)(dca)](3)}(3+), in which the macrocyclic ligand L adopts unsymmetrical RR/RR/SS or RR/SS/SS configurations. The homochiral nature of S-/R- and Delta-/Lambda- are confirmed by the results of solid circular dichroism (CD) spectra measurements. The magnetic properties of chiral Delta-/Lambda- and achiral were investigated. PMID:19690692

Zheng, Xiao-Dan; Jiang, Long; Feng, Xiao-Long; Lu, Tong-Bu

2009-09-14

306

1D coordination polymers formed by tetranuclear lead(II) building blocks with carboxylate ligands: In situ isomerization of itaconic acid  

International Nuclear Information System (INIS)

The synthesis of two new lead(II) coordination polymers, [Pb2(mpic)4(H2O)]·0.5H2O (1) and [Pb2(phen)2(cit)(mes)]·2H2O (2) has been reported, where mpic=3-methyl picolinate, phen=o-phenanthroline, H2cit=citraconic acid, H2mes mesaconic acid. X-ray single crystal diffraction analyses showed that the complexes comprise topologically different 1D polymeric chains stabilized by weak interactions and both containing tetranuclear Pb4 units connected by carboxylate groups. In compound 1 3-methylpicolinic acid is formed in situ from 3-methyl piconitrile, and mesaconate and citraconate anions were surprisingly formed from itaconic acid during the synthesis of 2. The photoluminescence and thermal properties of the complexes have been studied. - Graphical abstract: Two new topologically different 1D coordination polymers formed by Pb4 clusters have been synthesized and characterized by X-ray analysis. The luminescence and thermal properties have been studied. Display Omitted - Highlights: • Both the complexes, made up of different ligands, forms topologycally different 1D polymeric chains containing Pb4 clusters. • The final structures are stabilized by weak interactions (H-bond, ????? stacking). • In complex 1, the 3-methylpicolinic acid is generated in situ from 3-methyl piconitrile. • Mesaconate and citraconate anions are surprisingly formed in situ from itaconic acid during the synthesis of complex 2, indicating an exceptional transformation

307

Magnetic Anticrossing of 1D Subbands in Coupled Ballistic Double Quantum Wires  

Energy Technology Data Exchange (ETDEWEB)

We study the low-temperature in-plane magnetoconductance of vertically coupled double quantum wires. Using a novel flip-chip technique, the wires are defined by two pairs of mutually aligned split gates on opposite sides of a s 1 micron thick AlGaAs/GaAs double quantum well heterostructure. We observe quantized conductance steps due to each quantum well and demonstrate independent control of each ID wire. A broad dip in the magnetoconductance at -6 T is observed when a magnetic field is applied perpendicular to both the current and growth directions. This conductance dip is observed only when 1D subbands are populated in both the top and bottom constrictions. This data is consistent with a counting model whereby the number of subbands crossing the Fermi level changes with field due to the formation of an anticrossing in each pair of 1D subbands.

BLOUNT,MARK A.; MOON,JEONG-SUN; SIMMONS,JERRY A.; LYO,SUNGKWUN K.; WENDT,JOEL R.; RENO,JOHN L.

2000-07-13

308

Interaction between (1+1) D Gaussian spatial double solitons with losses in strongly nonlocal media  

International Nuclear Information System (INIS)

The propagation properties of (1+1) D Gaussian double light beams in strongly nonlocal nonlinear media with low losses are studied. By simplifying the nonlocal nonlinear Schroedinger equation which the light propagation in strongly nonlocal nonlinear media with low losses obeys, the propagation model of (1+1) D Gaussian double light beams in the media is obtained. With analysis method, the evolution laws of double light beams propagation are studied, the quasi double solitons solution is obtained. Further studies point out that the trajectories of the two light beams' centers in propagation are Airy functions; the two light beams will collide and separate; with the increase of propagation distance, the maximal distance between the two light beams' centers will become larger. When the losses increase, the collision spatial period will become smaller, and the maximal distance between the two light beams' centers will become larger. (authors)

309

Weighted similarity-invariant linear algorithm for camera calibration with rotating 1D objects.  

Science.gov (United States)

In this paper, a weighted similarity-invariant linear algorithm for camera calibration with rotating 1D objects is proposed. First, we propose a new estimation method for computing the relative depth of the free endpoint on the 1D object and prove its robustness against noise compared with those used in previous literature. The introduced estimator is invariant to image similarity transforms, resulting in a similarity-invariant linear calibration algorithm which is slightly more accurate than the well-known normalized linear algorithm. Then, we use the reciprocals of the standard deviations of the estimated relative depths from different images as the weights on the constraint equations of the similarity-invariant linear calibration algorithm, and propose a weighted similarity-invariant linear calibration algorithm with higher accuracy. Experimental results on synthetic data as well as on real image data show the effectiveness of our proposed algorithm. PMID:22531762

Shi, Kunfeng; Dong, Qiulei; Wu, Fuchao

2012-08-01

310

Static sign language recognition using 1D descriptors and neural networks  

Science.gov (United States)

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

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

2012-10-01

311

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

International Nuclear Information System (INIS)

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

312

FPGA Implementation of Efficient VLSI Architecture for Fixed Point 1-D DWT Using Lifting Scheme  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a scheme for the design of area efficient and high speed pipeline VLSI architecture for the computation of fixed point 1-d discrete wavelet transform using lifting scheme is proposed. The main focus of the scheme is to reduce the number and period of clock cycles and efficient area with little or no overhead on hardware resources. The fixed point representation requires less hardware resources compared with floating point representation. The pipelining architecture speeds up the clock rate of DWT and reduced bit precision reduces the area required for implementation. The architecture has been coded in verilog HDL on Xilinx platform and the target FPGA device used is Virtex-II Pro family, XC2VP7-7board. The proposed scheme requires the least computing time for fixed point 1-D DWT and achieves theless area for implementation, compared with other architectures. So this architecture is realizable for real time processing of DWT computation applications.

Durga Sowjanya

2012-09-01

313

Designing 1D grating for extraordinary optical transmission for TM polarization  

Science.gov (United States)

Due to their high brightness at resonance, 1D metallo-dielectric transmission gratings have been proposed as useful in a number of applications including Scanning Near-field Optical Microscopy (SNOM), flat-panel displays, spatial light modulators and optoelectronic devices. In this article, using the Fabry-Perot resonance condition and numerical optimization, we demonstrate a design methodology of 1D grating structure that provides resonance at a desired wavelength for Transverse Magnetic (TM) polarization. Depending on grating and substrate materials and target applications under consideration, our method provides optimum grating parameters, i.e. slit width, grating period and thickness adaptively. Application specific requirements such as the bandwidth around a resonance can be adjusted by setting appropriate constraint functions. Simulations results from modal analysis show that resonances are achieved at wavelengths for which grating parameters have been optimized.

Rahman, A. T. M. Anishur; Vasilev, Krasimir; Majewski, Peter

2012-01-01

314

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

Science.gov (United States)

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

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

2006-01-01

315

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

316

A 1D (radial) Plasma Jet Propagation Study for the Plasma Liner Experiment (PLX)  

Science.gov (United States)

The Plasma Liner Experiment will explore the formation of imploding spherical ``plasma liners'' that reach peak pressures of 0.1 Mbar upon stagnation. The liners will be formed through the merging of dense, high velocity plasma jets (n˜10^17 cm-3, T˜3 eV, v˜50 km/s) in a spherically convergent geometry. The focus of this 1D (radial) study is argon plasma jet evolution during propagation from the rail gun source to the jet merging radius. The study utilizes the Large Scale Plasma (LSP) PIC code with atomic physics included through the use of a non-Local Thermal Equilibrium (NLTE) Equation of State (EOS) table. We will present scenarios for expected 1D (radial) plasma jet evolution, from upon exiting the PLX rail gun to reaching the jet merging radius. The importance of radiation cooling early in the simulation is highlighted.

Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.; Welch, D. R.; Thoma, C.; Golovkin, I.; Macfarlane, J. J.; Case, A.; Messer, S. J.; Witherspoon, F. D.; Cassibry, J. T.; Awe, T. J.; Hsu, S. C.

2011-11-01

317

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

318

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

CERN Document Server

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

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

2004-01-01

319

An alternative scheme for the multiplexed acquisition of 1D and 2D NMR spectra  

Science.gov (United States)

Spin system selective 1D 1H, 2D DQF-COSY and 2D HSQC NMR spectra were recorded in order to fully assign the 1H and 13C 1D NMR spectra of an asymmetrical ?-cyclodextrin derivative. Instead of individually accessing the seven sugar anomeric protons by means of long multiplet selective pulses, only short region selective pulses were used. The simultaneously selected anomeric protons were differentiated by allowing their magnetization to evolve under the sole effect of the chemical shift interaction. In each experiment, the seven recorded spectra were linear combinations of the seven desired ones. The combination coefficients were measured and used to obtain almost perfectly separated sugar unit sub-spectra. This multiplexed acquisition scheme resulted in a time gain factor of about 2.

Plainchont, B.; Martinez, A.; Tisse, S.; Bouillon, J.-P.; Wieruszeski, J.-M.; Lippens, G.; Jeannerat, D.; Nuzillard, J.-M.

2010-09-01

320

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-05-15

 
 
 
 
321

Lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns  

Science.gov (United States)

Spatial scale plays an important role in many fields. As a scale-dependent measure for spatial heterogeneity, lacunarity describes the distribution of gaps within a set at multiple scales. In Earth science, environmental science, and ecology, lacunarity has been increasingly used for multiscale modeling of spatial patterns. This paper presents the development and implementation of a geographic information system (GIS) software extension for lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns. Depending on the application requirement, lacunarity analysis can be performed in two modes: global mode or local mode. The extension works for: (1) binary (1-bit) and grey-scale datasets in any raster format supported by ArcGIS and (2) 1D, 2D, and 3D point datasets as shapefiles or geodatabase feature classes. For more effective measurement of lacunarity for different patterns or processes in raster datasets, the extension allows users to define an area of interest (AOI) in four different ways, including using a polygon in an existing feature layer. Additionally, directionality can be taken into account when grey-scale datasets are used for local lacunarity analysis. The methodology and graphical user interface (GUI) are described. The application of the extension is demonstrated using both simulated and real datasets, including Brodatz texture images, a Spaceborne Imaging Radar (SIR-C) image, simulated 1D points on a drainage network, and 3D random and clustered point patterns. The options of lacunarity analysis and the effects of polyline arrangement on lacunarity of 1D points are also discussed. Results from sample data suggest that the lacunarity analysis extension can be used for efficient modeling of spatial patterns at multiple scales.

Dong, Pinliang

2009-10-01

322

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Quarteroni, Alfio; Milisic, Vuk

2004-01-01

323

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

324

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Zbigniew A. Lagodowski

2009-01-01

325

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)

326

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

327

FPGA Implementation of Efficient VLSI Architecture for Fixed Point 1-D DWT Using Lifting Scheme  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, a scheme for the design of area efficient and high speed pipeline VLSI architecture for the computation of fixed point 1-d discrete wavelet transform using lifting scheme is proposed. The main focus of the scheme is to reduce the number and period of clock cycles and efficient area with little or no overhead on hardware resources. The fixed point representation requires less hardware resources compared with floating point representation. The pipelining architecture speeds up th...

Durga Sowjanya; Srinivas, K. N. H.; Venkata Ganapathi, P.

2012-01-01

328

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

329

Probing the quantum state of a 1D Bose gas using off-resonant light scattering  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a theoretical treatment of coherent light scattering from an interacting 1D Bose gas at finite temperatures. We show how this can provide a nondestructive measurement of the atomic system states. The equilibrium states are determined by the temperature and interaction strength, and are characterized by the spatial density-density correlation function. We show how this correlation function is encoded in the angular distribution of the fluctuations of the scattered ...

Sykes, A. G.; Ballagh, R. J.

2011-01-01

330

VizieR Online Data Catalog: NGC 7129 FIRS 2 interferometric 1-D spectrum (Fuente+, 2014)  

Science.gov (United States)

Interferometric 1-D spectrum towards NGC 7129 FIRS 2 (RA=21:43:01.7, Dec=+66:03:23.6 J2000). The X-axis is frequency in MHz and the Y-axis is intensity in temperature units (K). The spectrum was observed with the IRAM Plateau de Bure Interferometer in CD configuration providing a synthesized beam of 1.43"x1.26" PA 144. The adopted source velocity is v=-10km/s. (2 data files).

Fuente, A.; Cernicharo, J.; Caselli, P.; McCoey, C.; Johnstone, D.; Fich, M.; van Kempen, T.; Palau, Aina; Yildiz, U. A.; Tercero, B.; Lopez, A.

2014-05-01

331

INFIL1D: a quasi-analytical model for simulating one-dimensional, constant flux infiltration  

International Nuclear Information System (INIS)

The program INFIL1D is designed to calculate approximate wetting-front advance into an unsaturated, uniformly moist, homogeneous soil profile, under constant surface-flux conditions. The code is based on a quasi-analytical method, which utilizes an assumed invariant functional relationship between reduced (normalized) flux and water content. The code uses general hydraulic property data in tabular form to simulate constant surface-flux infiltration. 10 references, 4 figures

332

Regulation of anthocyanin biosynthesis in Arabidopsis thaliana red pap1-D cells metabolically programmed by auxins.  

Science.gov (United States)

Red pap1-D cells of Arabidopsis thaliana have been cloned from production of anthocyanin pigmentation 1-Dominant (pap1-D) plants. The red cells are metabolically programmed to produce high levels of anthocyanins by a WD40-bHLH-MYB complex that is composed of the TTG1, TT8/GL3 and PAP1 transcription factors. Here, we report that indole 3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) regulate anthocyanin biosynthesis in these red cells. Seven concentrations (0, 0.2, 0.4, 2.2, 9, 18 and 27 ?M) were tested for the three auxins. IAA and 2,4-D at 2.2-27 ?M reduced anthocyanin levels. NAA at 0-0.2 ?M or above 9 ?M also decreased anthocyanin levels, but from 0.4 to 9 ?M, it increased them. HPLC-ESI-MS analysis identified seven cyanin molecules that were produced in red pap1-D cells, and their levels were affected by auxins. The expression levels of ten genes, including six transcription factors (TTG1, EGL3, MYBL2, TT8, GL3 and PAP1) and four pathway genes (PAL1, CHS, DFR and ANS) involved in anthocyanin biosynthesis were analyzed upon various auxin treatments. The resulting data showed that 2,4-D, NAA and IAA control anthocyanin biosynthesis by regulating the expression of TT8, GL3 and PAP1 as well as genes in the anthocyanin biosynthetic pathway, such as DFR and ANS. In addition, the expression of MYBL2, PAL1 and CHS in red pap1-D and wild-type cells differentially respond to the three auxins. Our data demonstrate that the three auxins regulate anthocyanin biosynthesis in metabolically programmed red cells via altering the expression of transcription factor genes and pathway genes. PMID:24370633

Liu, Zhong; Shi, Ming-Zhu; Xie, De-Yu

2014-04-01

333

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)

334

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

335

High-Resolution Radiation Hybrid Map of Wheat Chromosome 1D  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Physical mapping methods that do not rely on meiotic recombination are necessary for complex polyploid genomes such as wheat (Triticum aestivum L.). This need is due to the uneven distribution of recombination and significant variation in genetic to physical distance ratios. One method that has proven valuable in a number of nonplant and plant systems is radiation hybrid (RH) mapping. This work presents, for the first time, a high-resolution radiation hybrid map of wheat chromosome 1D (D geno...

Kalavacharla, Venu; Hossain, Khwaja; Gu, Yong; Riera-lizarazu, Oscar; Vales, M. Isabel; Bhamidimarri, Suresh; Gonzalez-hernandez, Jose L.; Maan, Shivcharan S.; Kianian, Shahryar F.

2006-01-01

336

Solar absorbers using 1D and 2D periodic nanostructured nickel films  

Science.gov (United States)

This paper presents results obtained from finite difference time domain and transfer matrix method modelling of nickel thin films. It is shown that by adding a periodic 1D grating to the surface of the nickel its optical absorption over the 300 nm–1000 nm spectral range can be dramatically increased. 2D gratings show excellent polarization independence making them ideally suited to high temperature solar thermal applications.

Ahmad, N.; Stokes, J.; Cryan, M. J.

2014-12-01

337

Structural and Population-Based Evaluations of TBC1D1 p.Arg125Trp  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Obesity is now a leading cause of preventable death in the industrialised world. Understanding its genetic influences can enhance insight into molecular pathogenesis and potential therapeutic targets. A non-synonymous polymorphism (rs35859249, p.Arg125Trp) in the N-terminal TBC1D1 phosphotyrosine-binding (PTB) domain has shown a replicated association with familial obesity in women. We investigated these findings in the Avon Longitudinal Study of Parents and Children (ALSPAC), a large Europea...

Richardson, Tom G.; Thomas, Elaine C.; Sessions, Richard B.; Lawlor, Debbie A.; Tavare?, Jeremy M.; Day, Ian N. M.

2013-01-01

338

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

339

Two-scale numerical simulation of the weakly compressible 1D isentropic Euler equations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Motivated by the difficulty to solve numerically the weakly compressible 1D isentropic Euler equations with classical methods, we develop in this paper a two scale numerical method on this model. This method is based on two scale convergence theory developped by N'Guetseng and Allaire, and finite volume scheme. Furthermore, we do some numerical simulations in order to verify that the two-scale numerical method is more and more accurate when the Mach number diminishes.

Fre?nod, Emmanuel; Mouton, Alexandre; Sonnendru?cker, Eric

2007-01-01

340

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

 
 
 
 
341

A systematic comparison between 1-D and 3-D hemodynamics in compliant arterial models.  

Science.gov (United States)

We present a systematic comparison of computational hemodynamics in arteries between a one-dimensional (1-D) and a three-dimensional (3-D) formulation with deformable vessel walls. The simulations were performed using a series of idealized compliant arterial models representing the common carotid artery, thoracic aorta, aortic bifurcation, and full aorta from the arch to the iliac bifurcation. The formulations share identical inflow and outflow boundary conditions and have compatible material laws. We also present an iterative algorithm to select the parameters for the outflow boundary conditions by using the 1-D theory to achieve a desired systolic and diastolic pressure at a particular vessel. This 1-D/3-D framework can be used to efficiently determine material and boundary condition parameters for 3-D subject-specific arterial models with deformable vessel walls. Finally, we explore the impact of different anatomical features and hemodynamic conditions on the numerical predictions. The results show good agreement between the two formulations, especially during the diastolic phase of the cycle. PMID:24115509

Xiao, Nan; Alastruey, Jordi; Alberto Figueroa, C

2014-02-01

342

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

343

Cutting edge: nonglycosidic CD1d lipid ligands activate human and murine invariant NKT cells.  

Science.gov (United States)

Invariant NKT cells (iNKT cells) recognize CD1d/glycolipid complexes. We demonstrate that the nonglycosidic compound threitolceramide efficiently activates iNKT cells, resulting in dendritic cell (DC) maturation and the priming of Ag-specific T and B cells. Threitolceramide-pulsed DCs are more resistant to iNKT cell-dependent lysis than alpha-galactosylceramide-pulsed DCs due to the weaker affinity of the human iNKT TCR for CD1d/ threitolceramide than CD1d/alpha-galactosylceramide complexes. iNKT cells stimulated with threitolceramide also recover more quickly from activation-induced anergy. Kinetic and functional experiments showed that shortening or lengthening the threitol moiety by one hydroxymethylene group modulates ligand recognition, as human and murine iNKT cells recognize glycerolceramide and arabinitolceramide differentially. Our data broaden the range of potential iNKT cell agonists. The ability of these compounds to assist the priming of Ag-specific immune responses while minimizing iNKT cell-dependent DC lysis makes them attractive adjuvants for vaccination strategies. PMID:18453560

Silk, Jonathan D; Salio, Mariolina; Reddy, B Gopal; Shepherd, Dawn; Gileadi, Uzi; Brown, James; Masri, S Hajar; Polzella, Paolo; Ritter, Gerd; Besra, Gurdyal S; Jones, E Yvonne; Schmidt, Richard R; Cerundolo, Vincenzo

2008-05-15

344

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

Science.gov (United States)

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

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

2014-04-01

345

Avidity-dependent programming of autoreactive T cells in T1D.  

Science.gov (United States)

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

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

2014-01-01

346

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)

347

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

Science.gov (United States)

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

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

2014-05-01

348

Inversion of MT profiles using laterally coupled 1D piecewise continuous models  

Science.gov (United States)

This paper presents a method for constructing coupled, 1D electrical conductivity models of the Earth from surface magnetotelluric measurements. The construction of the individual models is a nonlinear inverse problem that can be approached by linearization techniques combined with iterative methods and Tikhonov's regularization. The standard application of these techniques usually leads to smooth models that represent a continuous variation of conductivity with depth. In a previous work we described how these methods can be modified to incorporate what is known in Computer Vision as the line process (LP) decoupling technique, which has the ability to include discontinuities in the models. This results in piecewise smooth models which are often more adequate for representing stratified media. Now, the 1D models are coupled in order to include information from neighboring sites. We have implemented a relaxation technique to construct 2D profiles using coupled 1D models. We present numerical experiments and application to field data. In both cases we assume that the data is contaminated by static shift effects. The algorithm automatically takes these effects into account. The examples illustrate the performance of the combined LP and Tikhonov's regularization method in the solution of difficult practical problems.

Hidalgo Silva, Hugo; Gomez-Trevino, Enrique; Marroquin Zaleta, Jose L.

1998-10-01

349

Emergent 1d Ising Behavior in AN Elementary Cellular Automaton Model  

Science.gov (United States)

The fundamental nature of an evolving one-dimensional (1D) Ising model is investigated with an elementary cellular automaton (CA) simulation. The emergent CA simulation employs an ensemble of cells in one spatial dimension, each cell capable of two microstates interacting with simple nearest-neighbor rules and incorporating an external field. The behavior of the CA model provides insight into the dynamics of coupled two-state systems not expressible by exact analytical solutions. For instance, state progression graphs show the causal dynamics of a system through time in relation to the system's entropy. Unique graphical analysis techniques are introduced through difference patterns, diffusion patterns, and state progression graphs of the 1D ensemble visualizing the evolution. All analyses are consistent with the known behavior of the 1D Ising system. The CA simulation and new pattern recognition techniques are scalable (in both dimension, complexity, and size) and have many potential applications such as complex design of materials, control of agent systems, and evolutionary mechanism design.

Kassebaum, Paul G.; Iannacchione, Germano S.

350

High power 1D and 2D photonic crystal distributed feedback quantum cascade lasers  

Science.gov (United States)

For many practical applications that need bright sources of mid-infrared radiation, single mode operation and good beam quality are also required. Quantum cascade lasers are prominent candidates as compact sources of mid-infrared radiation capable of delivering very high power both CW and under pulsed operation. While 1D photonic crystal distributed feedback structures can be used to get single mode operation from quantum cascade lasers with narrow ridge widths, novel 2D photonic crystal cavity designs can be used to improve spectral and spatial purity of broad area quantum cascade lasers. In this paper, we demonstrate high power, spatially and spectrally pure operation at room temperature from narrow ridge and broad area quantum cascade lasers with buried 1D and 2D photonic crystal structures. Single mode continuous wave emission at ? = 4.8 ?m up to 700 mW in epi-up configuration at room temperature was observed from a 11 ?m wide 5 mm long distributed feedback quantum cascade laser with buried 1D gratings. High peak powers up to 34 W was obtained from a 3mm long 400 ?m wide 2D photonic crystal distributed feedback laser at room temperature under pulsed operation. The far field profile had a single peak normal to the laser facet and the M2 figure of merit was as low as 2.5. Emission spectrum had a dominating single mode at ? = 4.36 ?m.

Gökden, B.; Bai, Y.; Tsao, S.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

2011-01-01

351

A two-layer $\\alpha\\omega$ dynamo model, and its implications for 1-D dynamos  

CERN Document Server

I will discuss an attempt at representing an interface dynamo in a simplified, essentially 1D framework. The operation of the dynamo is broken up into two 1D layers, one containing the $\\alpha$ effect and the other containing the $\\omega$ effect, and these two layers are allowed to communicate with each other by the simplest possible representation of diffusion, an analogue of Newton's law of cooling. Dynamical back-reaction of the magnetic field on them with diagrams I computed for a comparable purely 1D model. The bifurcation structure shows remarkable similarity, but a couple of subtle changes imply dramatically different physical behaviour for the model. In particular, the solar-like dynamo mode found in the 1-layer model is not stable in the 2-layer version; instead there is an (apparent) homoclinic bifurcation and a sequence of periodic, quasiperiodic, and chaotic modes. I argue that the fragility of these models makes them effectively useless as predictors or interpreters of more complex dynamos.

Roald, C B

1999-01-01

352

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

353

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

354

A reference 1-D model of electrical conductivity for the upper mantle beneath the Philippine Sea  

International Nuclear Information System (INIS)

Complete text of publication follows. We have run a three-year-long seafloor electromagnetic (EM) survey project in the Philippine Sea in order to image electrical feature of deep mantle slab stagnating in the transition zone and surrounding mantle in three dimensions (3-D). The project iterated one-year-long deployment of ocean bottom electromagnetometers (OBEMs), involving total of 37 instruments installed at 18 sites. The data obtained by each phase have been analyzed in turn based on magnetotelluric (MT) method. As the first step toward the 3-D analysis, we have attempted to obtain one-dimensional (1-D) model which can be used as a reference model for the Philippine Sea mantle. To have a good representative model is critical for subsequent 3-D inversion analysis with quick and stable convergence. The seafloor MT responses are severely affected by surface heterogeneity because of high contrast in the conductivity between crustal rocks and seawater. Thus, the effect of the surface heterogeneity is stripped from the observed responses by 3-D forward modeling analysis. Then, the corrected responses are averaged over the sites and the mean response is inverted in a 1-D space. After a few iterations of this procedure, we obtain a 1-D conductivity model that is free from the effect of the surface heterogeneity. The resultant 1-D model shows that the mantle in 100 - 400 km depth is relatively homogeneous with about 0.03 S/m. In the mantle transition zone, the conductivitye mantle transition zone, the conductivity increases by 0.2 - 1.0 S/m. Both the upper mantle and the transition zone are much more conductive than the 1-D reference models for northern Pacific obtained by Utada et al. (2003), Kuvshinov et al. (2005) and Shimizu et al. (talk in this session). Some of the discrepancies may be attributed to the difference in water contents and/or in the degree of partial melting. However, we need more careful examination as they might be ascribed to different modeling approaches applied for the modeling of different scales.

355

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

Science.gov (United States)

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

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

2013-02-01

356

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

Directory of Open Access Journals (Sweden)

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

M. Carlotti

2013-02-01

357

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

Directory of Open Access Journals (Sweden)

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

M. Carlotti

2012-09-01

358

Development of 1D Particle-in-Cell Code and Simulation of Plasma-Wall Interactions  

Science.gov (United States)

This thesis discusses the development of a 1D particle-in-cell (PIC) code and the analysis of plasma-wall interactions. The 1D code (Plasma and Wall Simulation -- PAWS) is a kinetic simulation of plasma done by treating both electrons and ions as particles. The goal of this thesis is to study near wall plasma interaction to better understand the mechanism that occurs in this region. The main focus of this investigation is the effects that secondary electrons have on the sheath profile. The 1D code is modeled using the PIC method. Treating both the electrons and ions as macroparticles the field is solved on each node and weighted to each macro particle. A pre-ionized plasma was loaded into the domain and the velocities of particles were sampled from the Maxwellian distribution. An important part of this code is the boundary conditions at the wall. If a particle hits the wall a secondary electron may be produced based on the incident energy. To study the sheath profile the simulations were run for various cases. Varying background neutral gas densities were run with the 2D code and compared to experimental values. Different wall materials were simulated to show their effects of SEE. In addition different SEE yields were run, including one study with very high SEE yields to show the presence of a space charge limited sheath. Wall roughness was also studied with the 1D code using random angles of incidence. In addition to the 1D code, an external 2D code was also used to investigate wall roughness without secondary electrons. The roughness profiles where created upon investigation of wall roughness inside Hall Thrusters based off of studies done on lifetime erosion of the inner and outer walls of these devices. The 2D code, Starfish[33], is a general 2D axisymmetric/Cartesian code for modeling a wide a range of plasma and rarefied gas problems. These results show that higher SEE yield produces a smaller sheath profile and that wall roughness produces a lower SEE yield. Modeling near wall interactions is not a simple or perfected task. Due to the lack of a second dimension and a sputtering model it is not possible with this study to show the positive effects wall roughness could have on Hall thruster performance since roughness occurs from the negative affect of sputtering.

Rose, Laura P.

359

Using the D1D5 CFT to understand black holes  

Science.gov (United States)

The bound state of D1-branes and D5-branes in IIB string theory is an exceptionally fertile system for the study of black holes. The D1D5 system has two, dual descriptions: a gravitational and a conformal field theory (CFT) description. Here, we focus on using the two-dimensional CFT to understand black hole physics. After reviewing the D1D5 system, we first show how to perturbatively relax the decoupling limit to calculate the emission out of the AdS/CFT into the asymptotic flat space. We take the effect of the neck into account and fix the coupling between the CFT and the asymptotic flat space. This calculation is distinguished from other AdS-CFT calculations which only work in the strict decoupling limit and use the gravitational description to learn about strongly coupled field theory. We apply the formalism to particular smooth, horizonless three-charge nonextremal geometries. In the fuzzball proposal, these geometries are interpreted as black hole microstates, but they suffer from a classical instability. At first, the instability seems problematic in the fuzzball proposal; however, it was argued that if one used the D1D5 CFT then the instability could be interpreted as precisely the Hawking radiation process for the particular microstates. That the instability is classical, and not quantum mechanical results from a large Bose enhancement. In this document, we perform calculations that confirm this interpretation and demonstrate the above emission formalism. All of the calculations discussed thus far, and most of the calculations in the literature on the D1D5 CFT, are at the "orbifold point" in moduli space. This point is far from the black hole physics of interest, but some calculations agree anyway. To understand black holes better it seems likely that moving off of the orbifold point will become necessary. We present several calculations demonstrating the effect of a single application of the marginal deformation operator that moves the D1D5 CFT off its orbifold point. The deformation operator twists two copies of the orbifold CFT, which we show produces a "squeezed state" with an arbitrary number of excitations. Thus, initial high-energy excitations can fragment into many low-energy excitations. This deformation, should give rise to thermalization and other important black hole dynamics. Finally, we close with a brief summary and mention some opportunities for future work.

Avery, Steven G.

2010-10-01

360

Coupled 1D-3D hydrodynamic modelling, with application to the Pearl River Delta  

Science.gov (United States)

Within the hydrodynamic modelling community, it is common practice to apply different modelling systems for coastal waters and river systems. Whereas for coastal waters 3D finite difference or finite element grids are commonly used, river systems are generally modelled using 1D networks. Each of these systems is tailored towards specific applications. Three-dimensional coastal water models are designed to model the horizontal and vertical variability in coastal waters and are less well suited for representing the complex geometry and cross-sectional areas of river networks. On the other hand, 1D river network models are designed to accurately represent complex river network geometries and complex structures like weirs, barrages and dams. A disadvantage, however, is that they are unable to resolve complex spatial flow variability. In real life, however, coastal oceans and rivers interact. In deltaic estuaries, both tidal intrusion of seawater into the upstream river network and river discharge into open waters play a role. This is frequently approached by modelling the systems independently, with off-line coupling of the lateral boundary forcing. This implies that the river and the coastal model run sequentially, providing lateral discharge (1D) and water level (3D) forcing to each other without the possibility of direct feedback or interaction between these processes. An additional disadvantage is that due to the time aggregation usually applied to exchanged quantities, mass conservation is difficult to ensure. In this paper, we propose an approach that couples a 3D hydrodynamic modelling system for coastal waters (Delft3D) with a 1D modelling system for river hydraulics (SOBEK) online. This implies that contrary to off-line coupling, the hydrodynamic quantities are exchanged between the 1D and 3D domains during runtime to resolve the real-time exchange and interaction between the coastal waters and river network. This allows for accurate and mass conserving modelling of complex coastal waters and river network systems, whilst the advantages of both systems are maintained and used in an optimal and computationally efficient way. The coupled 1D-3D system is used to model the flows in the Pearl River Delta (Guangdong, China), which are determined by the interaction of the upstream network of the Pearl River and the open waters of the South China Sea. The highly complex upstream river network is modelled in 1D, simulating river discharges for the dry and wet monsoon periods. The 3D coastal model simulates the flow due to the external (ocean) periodic tidal forcing, the salinity distribution for both dry and wet seasons, as well as residual water levels (sea level anomalies) originating from the South China Sea. The model is calibrated and its performance extensively assessed against field measurements, resulting in a mean root mean square (RMS) error of below 6% for water levels over the entire Pearl River Delta. The model also represents both the discharge distribution over the river network and salinity transport processes with good accuracy, resolving the discharge distribution over the main branches of the river network within 5% of reported annual mean values and RMS errors for salinity in the range of 2 ppt (dry season) to 5 ppt (wet season).

Twigt, Daniel J.; de Goede, Erik D.; Zijl, Firmijn; Schwanenberg, Dirk; Chiu, Alex Y. W.

2009-12-01

 
 
 
 
361

REFLA-1D/MODE3: a computer code for reflood thermo-hydrodynamic analysis during PWR-LOCA  

International Nuclear Information System (INIS)

This manual describes the REFLA-1D/MODE3 reflood system analysis code. This code can solve the core thermo-hydrodynamics under forced flooding conditions and gravity feed conditions in a system similar to FLECHT-SET Phase A. This manual describes the REFLA-1D/MODE3 models and provides application information required to utilize the code. (author)

362

Thermally activated polymorphic transition from a 1D ribbon to a 2D carpet: squaric acid on Au(111).  

Science.gov (United States)

Polymorphic transition from the 1D ribbon to the 2D carpet superstructure of squaric acid molecules on Au(111) was achieved through a thermally activated process. Our combined STM and DFT study revealed that the molecular arrangements in 1D and 2D superstructures are determined by the stability of their conformational isomers and assembled structures, respectively. PMID:25116868

Ueji, Kan; Jung, Jaehoon; Oh, Junepyo; Miyamura, Kazuo; Kim, Yousoo

2014-10-01

363

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.)

364

Laser flash photolysis of ozone - O/1D/ quantum yields in the fall-off region 297-325 nm  

Science.gov (United States)

The wavelength dependence of the quantum yield for O(1D) production from ozone photolysis has been determined between 297.5 nm and 325 nm in order to resolve serious discrepancies among previous studies. The results of this investigation are compared to earlier work by calculating atmospheric production rate constants for O(1D). It is found that for the purpose of calculating this rate constant, there is now good agreement among three studies at 298 K. Furthermore, it appears that previous data on the temperature dependence of the O(1D) quantum yield fall-off is adequate for determining the vertical profile of the O(1D) production rate constant. Several experimental difficulties associated with using NO2(asterisk) chemiluminescence to monitor O(1D) have been identified.

Brock, J. C.; Watson, R. T.

1980-01-01

365

Identification of Regions Critical for the Integrity of the TSC1-TSC2-TBC1D7 Complex  

Science.gov (United States)

The TSC1-TSC2-TBC1D7 complex is an important negative regulator of the mechanistic target of rapamycin complex 1 that controls cell growth in response to environmental cues. Inactivating TSC1 and TSC2 mutations cause tuberous sclerosis complex (TSC), an autosomal dominant disorder characterised by the occurrence of benign tumours in various organs and tissues, notably the brain, skin and kidneys. TBC1D7 mutations have not been reported in TSC patients but homozygous inactivation of TBC1D7 causes megaencephaly and intellectual disability. Here, using an exon-specific deletion strategy, we demonstrate that some regions of TSC1 are not necessary for the core function of the TSC1-TSC2 complex. Furthermore, we show that the TBC1D7 binding site is encoded by TSC1 exon 22 and identify amino acid residues involved in the TSC1-TBC1D7 interaction. PMID:24714658

Santiago Lima, Arthur Jorge; Hoogeveen-Westerveld, Marianne; Nakashima, Akio; Maat-Kievit, Anneke; van den Ouweland, Ans; Halley, Dicky; Kikkawa, Ushio; Nellist, Mark

2014-01-01

366

Synthesis and serotonergic activity of arylpiperazide derivatives of serotonin: potent agonists for 5-HT1D receptors.  

Science.gov (United States)

A series of new arylpiperazide derivatives of serotonin has been prepared and evaluated as 5-HT1D receptor agonists. Binding experiments at cloned human 5-HT1D alpha, 5-HT1D beta, and 5-HT1A receptors show that all the compounds are very potent and selective ligands for 5-HT1D receptor subtypes. Functional activity studies (contraction of the New Zealand white rabbit saphenous vein) demonstrate that most of the derivatives behave as full agonists. Among them, the aryl sulfonamide derivative 5q (pD2 = 8.33 compare to 5.75 for sumatriptan) was also identified as a very potent agonist in inhibiting the forskolin-mediated cyclase coupled to 5-HT1D beta receptors (EC50 = 0.52nM). PMID:7658447

Perez, M; Fourrier, C; Sigogneau, I; Pauwels, P J; Palmier, C; John, G W; Valentin, J P; Halazy, S

1995-09-01

367

Pre-test parameter sensitivity analysis for the KNGR DVI performance test using a 1-D module of MARS  

International Nuclear Information System (INIS)

Pre-test analysis using a 1-D moduleof MARS 2.0 code has been performed for the KNGR (Korean Next Generation Reactor) DVI (Direct Vessel Injection) performance test facility which is a full height and 1/24.3 volume scaled separate effects test facility focusing on the identification of multi-dimensional thermal-hydraulic phenomena in the downcomer during the reflood conditions of a large break LOCA. From the steady state analyses for various test cases at the late reflood condition, the degree of major thermal-hydraulic phenomena such as ECC bypass, ECC penetration, steam condensation, and water level sweep-out are quantified. The MARS code analysis results showed that: (a) multi-dimensional flow and temperature behavior occurred in the downcomer region as expected, (b) the proximity of ECC injection to the break caused more ECC bypass and less steam condensation efficiency, (c) increasing the steam flow rate resulted in more ECC bypass and less steam condensation, and (d) the high velocity of steam flow swept-out the water in the downcomer just below the cold leg nozzle. These results are comparable with those observed in the previous tests such as UPTF and CCTF

368

Assessment of a 1-D, Multi-colour X-ray Imaging System for the MAST ST  

International Nuclear Information System (INIS)

A design of the ID soft x-ray imaging system for future experiments at the Mega-Amper Spherical Tokamak (MAST) and results of the numerical simulations based on initial assumptions about the state of the tokamak plasma as well as the parameters and geometry of the detection system are presented. The imaging system consists of a set of arrays of detectors, pinholes and filters attached to each set, together with suitable readout electronics. In simulations, an array of semiconductor detectors is compared with an array of scintillator-photomultiplier combination. The measuring system is assumed to operate in the range 1-10 keV. In addition to the 1-D imaging of x-ray emission, the system gives the possibility to measure the energy slope of x-ray spectrum and thus the electron temperature of plasma.An extended numerical code simulates the imaging system for various parameters of plasma (spatial profiles of the plasma density and temperature) generated at the tokamak and for different configurations of the detection system

369

Real-time defect detection in transparent multilayer polymer films using structured illumination and 1D filtering  

Science.gov (United States)

Today, typical polymer films consist of several functional layers, like printable surface or barrier layers. They are produced in coextrusion processes, in which the different materials are extruded through a single die and formed to a blown- or cast film with haul-off speeds up to 500 m/min. In the production of transparent multilayer films certain defects, called "interfacial instabilities", can occur. They emerge from shear stress and turbulences in the material flow during the process and result in a reduction of the mechanical properties and the optical quality of the product. Interfacial instabilities cannot be detected by conventional film inspection systems available on the market because the optical distortions they produce do not change the brightness of a pixel. In this paper, an approach for solving this problem is presented. The film is illuminated with a patterned line-light source in a backlight setting and a CCD line scan camera is used for recording the image lines. The defects can be detected using a 1D filter tuned to the spatial-frequency of the pattern. The distortion caused by the defects leads to a local extremum in the feature image generated by the filter, which can be easily detected by threshold segmentation. The system has been tested in an industrial setting and proved to be fast enough for inline-inspection. Further applications could be in the fast deflectometric inspection of high-gloss surfaces.

Michaeli, Walter; Berdel, Klaus; Osterbrink, Oliver

2009-06-01

370

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

International Nuclear Information System (INIS)

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

371

1-D fluid model of atmospheric-pressure rf He+O2 cold plasmas: Parametric study and critical evaluation  

International Nuclear Information System (INIS)

In this paper atmospheric-pressure rf He+O2 cold plasmas are studied by means of a 1-D fluid model. 17 species and 60 key reactions selected from a study of 250+ reactions are incorporated in the model. O2+, O3-, and O are the dominant positive ion, negative ion, and reactive oxygen species, respectively. Ground state O is mainly generated by electron induced reactions and quenching of atomic and molecular oxygen metastables, while three-body reactions leading to the formation of O2 and O3 are the main mechanisms responsible for O destruction. The fraction of input power dissipated by ions is ?20%. For the conditions considered in the study ?6% of the input power is coupled to ions in the bulk and this amount will increase with increasing electronegativity. Radial and electrode losses of neutral species are in most cases negligible when compared to gas phase processes as these losses are diffusion limited due to the large collisionality of the plasma. The electrode loss rate of neutral species is found to be nearly independent of the surface adsorption probability p for p > 0.001 and therefore plasma dosage can be quantified even if p is not known precisely.

372

Exact Ground States for Quasi 1D Systems with Hubbard Interaction  

Directory of Open Access Journals (Sweden)

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

Zs. Gulácsi

2012-03-01

373

Nonthermal O(1S) and O(1D) populations in cometary atmospheres  

Science.gov (United States)

Recent developments in the field of cometary science have motivated many studies dealing with the nucleus composition and mineralogy, and also with the photochemistry of the coma. In particular, ground based observations have shown that the visible oxygen emissions at 557.7 and 630 nm, both belonging to the Rosetta-VIRTIS-M passband, present different line profiles, pointing to specific photochemical processes. In this work, we present a Monte Carlo simulation of the O(1D) and O(1S) photochemistry including photodissociation of H2O, CO2 and CO, quenching, collisional thermalization and radiative decay. The model solves Boltzmann's integro differential equation including sources and sinks, as well as a prescribed expansion velocity of the coma. The energy distribution functions (EDF's) of O(1S) and O(1D) are computed at cometocentric distances ranging between 10 and 5000 km. We find that the EDF's of both O(1D) and O(1S) are strongly nonthermal, up to a degree that sharply varies with cometocentric distance, as thermalization is less efficient when the density of the dominant species is reduced. It follows that the Doppler profile of the visible radiations emitted by both species is non-gaussian in a frame of reference moving with the expanding coma. The nonthermal volume emission rate is then integrated along a set of chosen line of sights, accounting for the explicit Doppler profiles derived from the EDF's as well as the expansion motion, and the Doppler profile of the full coma is computed. It appears that most of the line width is due to the expansion motion, although the detailed line shape remains sensitive to the nonthermal nature of the EDF's. Our computation can then be compared with the line profiles observed from the ground with the UVES spectrograph mounted on the ESO-VLT.

Hubert, B. A.; Bisikalo, D. V.; Shematovich, V. I.; Gerard, J. M.; Decock, A.; Manfroid, J.; Hutsemekers, D.; Jehin, E.

2013-12-01

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Electrochemical cortisol immunosensors based on sonochemically synthesized zinc oxide 1D nanorods and 2D nanoflakes.  

Science.gov (United States)

We report on label free, highly sensitive and selective electrochemical immunosensors based on one-dimensional 1D ZnO nanorods (ZnO-NRs) and two-dimensional 2D ZnO nanoflakes (ZnO-NFs) which were synthesized on Au-coated substrates using simple one step sonochemical approach. Selective detection of cortisol using cyclic voltammetry (CV) is achieved by immobilizing anti-cortisol antibody (Anti-C(ab)) on the ZnO nanostructures (NSs). 1D ZnO-NRs and 2D ZnO-NFs provide unique sensing advantages over bulk materials. While 1D-NSs boast a high surface area to volume ratio, 2D-NSs with large area in polarized (0001) plane and high surface charge density could promote higher Anti-C(ab) loading and thus better sensing performance. Beside large surface area, ZnO-NSs also exhibit higher chemical stability, high catalytic activity, and biocompatibility. TEM studies showed that both ZnO-NSs are single crystalline oriented in (0001) plane. The measured sensing parameters are in the physiological range with a sensitivity of 11.86 µA/M exhibited by ZnO-NRs and 7.74 µA/M by ZnO-NFs with the lowest detection limit of 1 pM which is 100 times better than conventional enzyme-linked immunosorbant immunoassay (ELISA). ZnO-NSs based cortisol immunosensors were tested on human saliva samples and the performance were validated with conventional (ELISA) method which exhibits a remarkable correlation. The developed sensors can be integrated with microfluidic system and miniaturized potentiostat for point-of-care cortisol detection and such developed protocol can be used in personalized health monitoring/diagnostic. PMID:25064820

Vabbina, Phani Kiran; Kaushik, Ajeet; Pokhrel, Nimesh; Bhansali, Shekhar; Pala, Nezih

2015-01-15