An Interactive Program on Digitizing Historical Seismograms
Xu, Y.; Xu, T.
2013-12-01
Retrieving information from historical seismograms is of great importance since they are considered the unique sources that provide quantitative information of historical earthquakes. Modern techniques of seismology require digital forms of seismograms that are essentially a sequence of time-amplitude pairs. However, the historical seismograms, after scanned into computers, are two dimensional arrays. Each element of the arrays contains the grayscale value or RGB value of the corresponding pixel. The problem of digitizing historical seismograms, referred to as converting historical seismograms to digital seismograms, can be formulated as an inverse problem that generating sequences of time-amplitude pairs from a two dimension arrays. This problem has infinite solutions. The algorithm for automatic digitization of historical seismogram presented considers several features of seismograms, including continuity, smoothness of the seismic traces as the prior information, and assumes that the amplitude is a single-valued function of time. An interactive program based on the algorithm is also presented. The program is developed using Matlab GUI and has both automatic and manual modality digitization. Users can easily switch between them, and try different combinations to get the optimal results. Several examples are given to illustrate the results of digitizing seismograms using the program, including a photographic record and a wide-angle reflection/refraction seismogram. Digitized result of the program (redrawn using Golden Software Surfer for high resolution image). (a) shows the result of automatic digitization, and (b) is the result after manual correction.
International Nuclear Information System (INIS)
In clastic and carbonate rock sequences, the neutron and sonic log curves usually deflect in a similar fashion. Moreover, in some cases the two curves can be overlain and they generally appear to mimic each other, with variations between them only in the amplitudes of the two curves. This descriptive correlation is the basis of direct cross-plot techniques used to convert a neutron log into a pseudo-sonic log, which can then be combined with a density log to create a pseudo-synthetic seismogram. Unfortunately, the seismograms produced in this way may not match the standard synthetic seismograms produced from the sonic and density logs if the ‘gas effect’ is not taken into account. In order to correct for the gas effect, the inter-log correlations between the compensated neutron log (CNL) and the borehole-compensated (BHC) sonic log curves from a well in Taiwan were carefully examined. Then, we developed a technique for transforming the CNL log into a pseudo-BHC log by splicing together several continuous sandstone intervals in which the gas effect could be identified from the scattered data on the cross-plot of neutron porosity versus sonic interval transit time. Based upon our results, application of the new composite transform method yields a pseudo-synthetic seismogram that better matches the standard synthetic seismogram (made from the sonic and density logs) according to frequency, amplitude and polarity. This gas correction technique may be particularly usefion technique may be particularly useful in oil and gas exploratory and development areas where neutron logs are more prevalent than sonic logs or where sonic logs are scarce. (paper)
Kung, Shih-Ling; Lewis, Charles; Wu, Jong-Chang
2013-06-01
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.
Instaseis: instant global seismograms based on a broadband waveform database
van Driel, M.; Krischer, L.; Stähler, S. C.; Hosseini, K.; Nissen-Meyer, T.
2015-03-01
We present a new method and implementation (Instaseis) to store global Green's functions in a database which allows for near-instantaneous (on the order of milliseconds) extraction of arbitrary seismograms. Using the axisymmetric spectral element method (AxiSEM), the generation of these databases, based on reciprocity of the Green's functions, is very efficient and is approximately half as expensive as a single AxiSEM forward run. Thus, this enables the computation of full databases at half the cost of the computation of seismograms for a single source in the previous scheme and allows to compute databases at the highest frequencies globally observed. By storing the basis coefficients of the numerical scheme (Lagrange polynomials), the Green's functions are 4th order accurate in space and the spatial discretization respects discontinuities in the velocity model exactly. High order temporal interpolation using Lanczos resampling allows to retrieve seismograms at any sampling rate. AxiSEM is easily adaptable to arbitrary 1-D models or other spherical objects such as Mars. In this paper, we present the basic rationale and details of the method as well as benchmarks and illustrate a variety of applications. The code is open source and available with extensive documentation at http://www.instaseis.net.
Users can access the array of seismometers operated by the the University of California at Berkeley's Seismological Laboratory in northern and central California. The Berkeley Digital Seismic Network is an array of high-dynamic range, broadband seismometers. Data from these instruments are transmitted continuously to UC Berkeley for processing and analysis. Using the interface, visitors may create a seismogram by selecting the desired station, channel, time period, and plotting parameters.
Efficient Synthesis of Seismograms via Path Integration
Schlottmann, R. B.; Baig, A. M.
2002-12-01
Global seismology is at a critical stage in its maturation as a field of study. With the advent of broadband digital seismic networks, we have been inundated with a wealth of high-quality data. This new data has brought global traveltime tomographic images close to their saturation point, i.e., the point at which additional measurements make a negligible difference in the major features observed, given present station coverage and the natural source distribution. More stringent seismic constraints on the details of the Earth's deep structure can be obtained only by including the additional information recorded in the seismic waveform. This valuable information is most effectively extracted by the comparison of data with synthetic waveforms computed for a proposed structure model. The need for a practical and accurate method of generating these synthetics for the propagation of broadband seismic waves through realistic, 3-D models has never been greater. However, at the present time practicality and accuracy are almost mutually exclusive. Practicality is achievable if one is willing to settle for high-frequency asymptotic solutions or for models with merely 1-D variations or for both. Until recent years, these "practical" methods were really the only methods available to seismologists, but now those who have plenty of computing power and memory, and plenty of patience, can generate very accurate seismograms up to frequencies that are approaching the range of low-frequency teleseismic S-waves. Here we present an alternative approach, one that provides an adjustable compromise between computational speed and accuracy. We recast an existing path integral solution for acoustic wave propagation in a form that is immensely more amenable to numerical implementation. Several comparisons between the new path integral method and slower, established numerical methods for nontrivial 3-D media will be made.
Method for rapid high-frequency seismogram calculation
Stabile, Tony Alfredo; De Matteis, Raffaella; Zollo, Aldo
2009-02-01
We present a method for rapid, high-frequency seismogram calculation that makes use of an algorithm to automatically generate an exhaustive set of seismic phases with an appreciable amplitude on the seismogram. The method uses a hierarchical order of ray and seismic-phase generation, taking into account some existing constraints for ray paths and some physical constraints. To compute synthetic seismograms, the COMRAD code (from the Italian: "COdice Multifase per il RAy-tracing Dinamico") uses as core a dynamic ray-tracing code. To validate the code, we have computed in a layered medium synthetic seismograms using both COMRAD and a code that computes the complete wave field by the discrete wave number method. The seismograms are compared according to a time-frequency misfit criteria based on the continuous wavelet transform of the signals. Although the number of phases is considerably reduced by the selection criteria, the results show that the loss in amplitude on the whole seismogram is negligible. Moreover, the time for the computing of the synthetics using the COMRAD code (truncating the ray series at the 10th generation) is 3-4-fold less than that needed for the AXITRA code (up to a frequency of 25 Hz).
Synthetic seismogram web service and Python tools
Heimann, Sebastian; Cesca, Simone; Kriegerowski, Marius; Dahm, Torsten
2014-05-01
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
Streaming Seismograms into Earth-Science Classrooms
Ammon, C. J.
2011-12-01
Seismograms are the fundamental observations upon which seismology is based; they are central to any course in seismology and important for any discussion of earthquake-related phenomena based on seismic observations. Advances in the collection and distribution of seismic data have made the use of research-quality seismograms in any network capable classroom feasible. The development of large, deep seismogram archives place an unprecedented quantity of high-quality data within reach of the modern classroom environment. I describe and discuss several computer tools and classroom activities that I use in introductory (general education) and advanced undergraduate courses that present near real-time research-quality seismic observations in the classroom. The Earth Motion Monitor Application (EMMA), is a MacOS application that presents a visually clear seismogram display that can be projected in classrooms with internet access. Seismic signals from thousands of station are available from the IRIS data center and the bandwidth can be tailored to the particular type of signal of interest (large event, low frequencies; small event, high frequencies). In introductory classes for non-science students, the near realtime display routinely shows magnitude 4.0-5.0 earthquake-generated signals, demonstrating to students the frequency of earthquake occurrence. Over the next few minutes as the waves travel through and across the planet, their arrival on the seismogram display provides some basic data for a qualitative estimate of the event's general location. When a major or great earthquake occurs, a broad-band display of signals from nearby stations can dramatically and dynamically illuminate the frequent activity associated with the aftershock sequence. Routine use of the display (while continuing the traditional classroom activities) provides students with a significant dose of seismogram study. Students generally find all the signals, including variations in seismic background motions, interesting and formulate good questions related to the signal details. A few minutes at the beginning of class reviewing the activity between classes and a few minutes when an earthquake occurs provide valuable discussion points related to earthquake science and seismic-wave propagation. Other tools discussed are related to global earthquake geography, with self-updating global maps of earthquakes (Epicentral, a MacOS and iOS application). When a signal first shows up on the EMMA seismogram display, students can invest a few minutes estimating the event's general location (and checking the signal character - relative arrival times, dispersion, etc). When a location is posted by an appropriate authority (e.g. the U. S. Geological Survey) the student's estimates can be checked and discussed. Additionally, Epicentral for MacOS presents a self-updated Twitter stream that can light up substantially when a felt earthquake occurs. Although the language of many of the tweeters can be colorful, the results are interesting and instant. The inclusion of these tools takes some time away from traditional lectures, but helps produce a dynamic, thought-provoking classroom experience.
Model-Based Signal Processing: Correlation Detection With Synthetic Seismograms
Rodgers, A.; Harris, D.; Pasyanos, M.; Blair, S.; Matt, R.
2006-12-01
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.
Directory of Open Access Journals (Sweden)
Bagus Jaya Santosa
2005-04-01
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.
Performance optimization of a thermoelectric generator with linear material profiles in a 1D setup
Energy Technology Data Exchange (ETDEWEB)
Zabrocki, Knud; Mueller, Eckhard [Institute of Materials Research, German Aerospace Center (DLR), Koeln (Germany); Seifert, Wolfgang; Trimper, Steffen [Martin Luther University Halle-Wittenberg, Halle (Saale) (Germany)
2010-07-01
Graded and segmented thermoelectric elements have been studied for a long time with the aim of improving the performance of thermogenerators that are exposed to a large temperature difference. The global optimization of a performance parameter is commonly based on a one-dimensional continua-theoretical model. Following the proposal by Mueller et al., the temperature profile T(x) can be calculated within a model-free setup directly from the 1D thermal energy balance, e. g. based on an independent and free variability of the material parameters the Seebeck coefficient, the electrical and thermal conductivities, S(x), {sigma}(x) and {kappa}(x) is assumed primarily. Thus the optimum current density can be determined from the maximum of the global performance parameter. Here, an analytical solution of the 1D thermal energy balance has been found for constant gradients based on Bessel functions. For particular cases of linear material profiles the authors present results for the optimization of performance parameters like the electrical power output P{sub el} and the efficiency {eta} of a thermogenerator (TEG). These results are compared with another analytical model, the constant property model (CPM) and a suitable reference for the performance is discussed.
Wu, Huinan; Huang, Jinjer; Pu, Shaozhi; Zhang, Liuyang; Yang, Zhongying
2015-01-01
Phase and group velocity matching equations of second harmonic generation are reconsidered for 1D photonic crystals to analyze an induced structure restriction. A multiplicity of solutions is found through a numerical computation, which separates the restricted structure parameters into infinite units. The local and global characteristics of the restriction on refractive indices and material lengths are discussed in detail as well. The analysis shows that increasing either the dispersion of the nonlinear material or the thickness of a single layer will require a larger refractive index contrast.
An Accurate and Efficient Method of Computing Differential Seismograms
Hu, S.; Zhu, L.
2013-12-01
Inversion of seismic waveforms for Earth structure usually requires computing partial derivatives of seismograms with respect to velocity model parameters. We developed an accurate and efficient method to calculate differential seismograms for multi-layered elastic media, based on the Thompson-Haskell propagator matrix technique. We first derived the partial derivatives of the Haskell matrix and its compound matrix respect to the layer parameters (P wave velocity, shear wave velocity and density). We then derived the partial derivatives of surface displacement kernels in the frequency-wavenumber domain. The differential seismograms are obtained by using the frequency-wavenumber double integration method. The implementation is computationally efficient and the total computing time is proportional to the time of computing the seismogram itself, i.e., independent of the number of layers in the model. We verified the correctness of results by comparing with differential seismograms computed using the finite differences method. Our results are more accurate because of the analytical nature of the derived partial derivatives.
A hybrid method for the computation of quasi-3D seismograms.
Masson, Yder; Romanowicz, Barbara
2013-04-01
The development of powerful computer clusters and efficient numerical computation methods, such as the Spectral Element Method (SEM) made possible the computation of seismic wave propagation in a heterogeneous 3D earth. However, the cost of theses computations is still problematic for global scale tomography that requires hundreds of such simulations. Part of the ongoing research effort is dedicated to the development of faster modeling methods based on the spectral element method. Capdeville et al. (2002) proposed to couple SEM simulations with normal modes calculation (C-SEM). Nissen-Meyer et al. (2007) used 2D SEM simulations to compute 3D seismograms in a 1D earth model. Thanks to these developments, and for the first time, Lekic et al. (2011) developed a 3D global model of the upper mantle using SEM simulations. At the local and continental scale, adjoint tomography that is using a lot of SEM simulation can be implemented on current computers (Tape, Liu et al. 2009). Due to their smaller size, these models offer higher resolution. They provide us with images of the crust and the upper part of the mantle. In an attempt to teleport such local adjoint tomographic inversions into the deep earth, we are developing a hybrid method where SEM computation are limited to a region of interest within the earth. That region can have an arbitrary shape and size. Outside this region, the seismic wavefield is extrapolated to obtain synthetic data at the Earth's surface. A key feature of the method is the use of a time reversal mirror to inject the wavefield induced by distant seismic source into the region of interest (Robertsson and Chapman 2000). We compute synthetic seismograms as follow: Inside the region of interest, we are using regional spectral element software RegSEM to compute wave propagation in 3D. Outside this region, the wavefield is extrapolated to the surface by convolution with the Green's functions from the mirror to the seismic stations. For now, these Green's functions are computed using 2D SEM simulation in a 1D Earth model. Such seismograms account for the 3D structure inside the region of interest in a quasi-exact manner. Later we plan to extrapolate the misfit function computed from such seismograms at the stations back into the SEM region in order to compute local adjoint kernels. This opens a new path toward regional adjoint tomography into the deep Earth. Capdeville, Y., et al. (2002). "Coupling the spectral element method with a modal solution for elastic wave propagation in global Earth models." Geophysical Journal International 152(1): 34-67. Lekic, V. and B. Romanowicz (2011). "Inferring upper-mantle structure by full waveform tomography with the spectral element method." Geophysical Journal International 185(2): 799-831. Nissen-Meyer, T., et al. (2007). "A two-dimensional spectral-element method for computing spherical-earth seismograms-I. Moment-tensor source." Geophysical Journal International 168(3): 1067-1092. Robertsson, J. O. A. and C. H. Chapman (2000). "An efficient method for calculating finite-difference seismograms after model alterations." Geophysics 65(3): 907-918. Tape, C., et al. (2009). "Adjoint tomography of the southern California crust." Science 325(5943): 988-992.
Inpainting of historical seismograms using sparse representation method
Wang, Lifu; Sun, Yi; Cai, Xiaogang
2015-01-01
This paper presents a method of inpainting historical seismograms recorded by a pen and paper drum-type seismograph. In the seismogram, some portions of the wave may be lost or distorted owing to time marks or violent shaking. In this study, the seismic waveform is divided into several frames of equal length, and the lost or distorted portions are restored frame by frame. Because a seismogram contains several repetitive patterns in the entire waveform, each frame can be sparsely represented on the basis of these patterns. Therefore, the sparse representation model is employed to represent historical seismograms. In addition, an inpainting model that employs sparsity as a prior is formulated, and it is used to restore the lost portions by solving a L0-norm minimization problem. However, this minimization problem may be ill posed and result in an incorrect outcome if the missing interval duration of the wave is very large. Therefore, to solve this ill-posed problem, a prior based on the Fourier spectrum of the waveform is added to the inpainting method. Simulation results prove that the proposed inpainting method can restore the missing wave well.
Blind deconvolution of seismograms regularized via minimum support
Royer, A.; Bostock, M. G.; Haber, E.
2010-12-01
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.
Wavelet analysis of the seismograms for tsunami warning
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A. Chamoli
2010-10-01
Full Text Available The complexity in the tsunami phenomenon makes the available warning systems not much effective in the practical situations. The problem arises due to the time lapsed in the data transfer, processing and modeling. The modeling and simulation needs the input fault geometry and mechanism of the earthquake. The estimation of these parameters and other aprior information increases the utilized time for making any warning. Here, the wavelet analysis is used to identify the tsunamigenesis of an earthquake. The frequency content of the seismogram in time scale domain is examined using wavelet transform. The energy content in high frequencies is calculated and gives a threshold for tsunami warnings. Only first few minutes of the seismograms of the earthquake events are used for quick estimation. The results for the earthquake events of Andaman Sumatra region and other historic events are promising.
On-demand synthetic seismograms from the IRIS DMC
Hutko, A. R.; Trabant, C. M.; Karstens, R.; Nissen-Meyer, T.; Bahavar, M.
2013-12-01
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.
Directory of Open Access Journals (Sweden)
Bagus Jaya Santosa
2008-09-01
Full Text Available This research investigates earth structure beneath the Southwest North America landmass, especially between Mexico and California. Models based on S wave velocities for this area were obtained by carrying out seismogram fitting in time domain and three Cartesian components simultaneously. The data used is from an event, coded as C052297B that occurred in the state of Guerrero, Mexico and it was fitted to synthetic data computed with the GEMINI program at TS network stations. Earth model IASPEI91 and SPREM were used as input to create the synthetic data. Real and synthetic seismograms were subjected to a low-pass filter with a frequency corner of 20 mHz.Waveform analysis results show very unsystematic and strong deviations in the waveform, arrival times, amount of oscillation and the height of the wave amplitude. Discrepancies are met on S, Love, Rayleigh and ScS waves, where the stations epicentral distances are below 300. Deviation in analysis waveform because of the usage of model 1-D of SPREM and IASPEI91, because the 1-D was a kind of average value an elastic property at one particular depth of global earth. With the method of waveform analysis we can see how sensitive waveform is to structures within the layers of the Earth.To explain the discrepancies, a correction to the earth structure is essential. The corrections account for the thickness of the crust, speed gradient of bh, the coefficient for the bh and bv in the upper mantle for surface wave fitting, a small variation of the S speed structure at a layer under the upper mantle above 771 km for S wave fitting, and a small variation at the base the mantle layers for ScS wave fitting. At some stations, a correction for S speed structure have yielded P wave fitting. Results of this research indicate that the 1-D earth model obtained through seismogram fitting at every hypocenter-observation station pair is unique. The S-wave velocity on the upper mantle has strong negative anomalies. This paper criticized the previous earth models in the same area, which have been published by other seismologists, by analyzing the seismogram of C052297B earthquake in the TS seismological network station
Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods
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Milton P. Plasencia Linares
2005-11-01
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.
Slanger, T. G.; Copeland, R. A.; Kalogerakis, K. S.; Byler, E. B.; Jia, B.; Pejakovic, D. A.
2008-12-01
The reaction between O(1D) and ozone is highly exothermic, with a variety of possible pathways, and includes all states of O2 lying below the first dissociation limit at 5.1 eV. The three Herzberg states at 4 - 5 eV and even the 5?g state - bound by only ~0.1 eV - are all accessible. Our interest has been to generate the lowest vibrational level of the lowest Herzberg state, O2(c1?u-), because O2(c-X) v'=0 emission is a major nightglow feature in the visible spectral region of Venus and presumably of Mars. Although the c1?u-(v = 0) level is known to be produced by O- atom recombination in a flowing afterglow [Lawrence, et al., 1977; Slanger, 1978; Kenner and Ogryzlo, 1983], it has not previously been generated in a pulsed experiment, where kinetics can be most easily determined. We find that photodissociation of ozone at 248 nm rapidly generates the v=0 levels of all three O2 Herzberg states - c1?u-, A3?u+, and A'3?u - as observed in the Herzberg I/II/III and Chamberlain bands. These levels appear as the O(1D) disappears, each exhibiting different time histories. From earlier work, we established that the O(1D) + O3 reaction generates high vibrational levels of the O2 states [Slanger and Copeland, 2003], but here we see the lowest level. The O2(b - X) Atmospheric bands appear over a yet longer time scale. Emission from the O(1D - 3P) red lines is a prominent feature in these experiments, although the radiating efficiency is only about 10-7. This work has been supported by Grant No. NNG05GO77G from the NASA Planetary Atmospheres program. E. Byler participated as an NSF REU (Research Experience for Undergraduates) student. G.M. Lawrence, et al. Science., 195, 573, 1977. T.G. Slanger, J. Chem. Phys., 69, 4779, 1978. R.D. Kenner and E.A. Ogryzlo, Can. J. Chem., 61, 921, 1983. T.G. Slanger and R.A. Copeland, Chem. Rev. 103, 4731, 2003.
International Nuclear Information System (INIS)
Thermoelectric devices are semiconductor devices which are capable of either generating a voltage when placed in between a temperature gradient, exploiting the Seebeck effect, or producing a temperature gradient when powered by electricity, exploiting the Peltier effect. The devices are usually employed in environments with time-varying temperature differences and input/output powers. Therefore it becomes important to understand the behaviour of thermoelectric devices during thermal and electrical transients in order to properly simulate and design complex thermoelectric systems which also include power electronics and control systems. The purpose of this paper is to provide the transient solution to the one-dimensional heat conduction equation with internal heat generation that describes the transfer and generation of heat throughout a thermoelectric device. The solution proposed can be included in a model in which the Peltier effect, the thermal masses and the electrical behaviour of the system are considered too; this would be of great benefit because it would allow accurate simulations of thermoelectric systems. While the previous literature does not focus on the study of thermal transients in thermoelectric applications and usually considers constant the temperatures at the hot and cold sides, this paper proposes a dynamic exchange of heat through the hot and cold side, both in steady-state and transients. This paper also presents an analytical solution which is presents an analytical solution which is then computed by Matlab to simulate a physical experiment. Simulation results show excellent correlation with experimentally determined values, thus validating the solution. - Highlights: ? We solve the one-dimensional heat conduction equation for thermoelectric devices. ? Both the steady-state and transient solutions are provided. ? This solution can be used to accurately simulate thermoelectric systems. ? Simulations and experimental results are provided.
I 2 dissociation by O 2( a1?) generated from the reaction O( 1D) + N 2O
Azyazov, Valeriy N.; Heaven, Michael C.
2011-01-01
A new kinetic scheme for the dissociation of I 2 by O 2( a1?) has been proposed by Azyazov et al. [7]. The reactions initiated by UV photolysis of N 2O/I 2 mixtures have been used to probe details of this dissociation model, and provide additional validation. Pulsed photolysis of both N 2O and I 2, was used to generate I( 2P 1/2), I( 2P 3/2), and O 2( a1?). Emission spectroscopy and laser induced fluorescence techniques were used to follow the time evolutions of I( 2P 1/2) and I 2. Suppression of the chain propagation stage of I 2 dissociation has been observed for the first time. Computational modeling indicated that the observed kinetics are consistent with the revised dissociation model.
Vandermonde matrix analysis of long-period seismograms
Gilbert, Freeman
2001-09-01
Seismograms recorded by the Global Seismic Network can be processed to obtain receiver strips for each earthquake. The receiver strips for all earthquakes can be analysed simultaneously in the time domain by using the representation in terms of exponentially decaying sinusoids (signal poles). The (time, strip) matrix is the product of two matrices, a Vandermonde matrix of signal poles and a matrix of excitation amplitudes. The shift-invariant property of Vandermonde matrices can be used to determine the signal poles (and hence the complex eigenfrequencies) and, subsequently, the excitation amplitudes. The latter provide the source vectors for each multiplet and earthquake. They can be combined with the eigenfrequencies and amplitudes to form a system of linear equations for the coupling-splitting matrices that constrain 3-D structure. In some cases multiplets whose eigenfunctions are insensible in the upper mantle are quasi-resonantly coupled to well-observed multiplets. The Vandermonde matrix analysis can often be extended to these `latent' multiplets and their coupling-splitting matrices can be determined. The source vectors for each multiplet and for each earthquake are constraints on the source mechanism of the earthquake. Thus, the investigation of the earthquake mechanism can be performed independently of the investigations of aspherical structure. This separation is one of the strengths of Vandermonde matrix analysis.
Telesca, Luciano; Chamoli, Ashutosh; Lovallo, Michele; Stabile, Tony Alfredo
2014-06-01
Revealing the tsunamigenic potential of an earthquake is very challenging in regards to minimizing the casualties a tsunami can provoke. Thus, development of methodologies that can reliably furnish a early warnings of a tsunami is crucial. In order to accomplish this aim it is important to preliminarily identify the characteristics of seismograms that can be used to distinguish tsunamigenic (TS) earthquakes from non-tsunamigenic (NTS) earthquakes. In this paper P-wave time dynamic of 17 seismograms of TS earthquakes and 26 NTS seismograms are analysed by means of two advanced statistical tools: the Fisher-Shannon method and the multifractal detrended fluctuation analysis (MFDFA). Both methods are well suited to disclosing the inner time properties of complex signals, as seismograms appear to be. Using these two methods jointly, we defined a classifier, the performance of which was tested by means of the receiver-operating characteristic curve that plots true positive rate versus false positive rate. This classifier shows a discrimination power that can be considered acceptable in comparison with the devastating effects caused by a non-alarmed tsunami. Our findings indicate that proper choice of the classifier's threshold allows correctly identification of approximately 69 % of the NTS seismograms and approximately 76 % of the TS seismograms. The presented results presented may be helpful in addressing the complex problem of early tsunami warning.
Investigating the inner time properties of seismograms by using the Fisher Information Measure
Telesca, Luciano; Lovallo, Michele; Alcaz, Vasile; Ilies, Ion
2014-09-01
The time dynamics of seismograms of nine tectonic earthquakes which occurred in Vrancea (Romania) registered at three seismic stations located in Moldova are analyzed by means of the informational approach of the Fisher Information Measure (FIM). The three seismic stations in Moldova are located, two (MILM and LEOM) within an area with high seismic hazard, while the third (SORM) in a less hazardous region. Our findings point out to a clear discrimination of the two stations MILM and LEOM from SORM on the basis of the informational properties of the recorded seismograms corresponding to the same earthquakes. In particular it is found that larger distance and lower azimuth characterize seismograms with lower FIM, which implies lower organization and higher disorder in seismograms recorded by SORM with respect to those recorded by MILM and LEOM. The lower FIM revealed by seismograms recorded by SORM could be put in relationship with the lower degree of seismic hazard in the area where the seismic station is installed.
Seismogram Analysis of C052198B Earthquake, Minahasa at Observatory Stations in Australia
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Bagus Jaya Santosa
2012-03-01
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.
Luo, Y.; Xia, J.; Liu, J.; Xu, Y.; Liu, Q.
2008-01-01
Multichannel Analysis of Surface Waves utilizes a multichannel recording system to estimate near-surface shear (S)-wave velocities from high-frequency Rayleigh waves. A pseudo-2D S-wave velocity (vS) section is constructed by aligning 1D models at the midpoint of each receiver spread and using a spatial interpolation scheme. The horizontal resolution of the section is therefore most influenced by the receiver spread length and the source interval. The receiver spread length sets the theoretical lower limit and any vS structure with its lateral dimension smaller than this length will not be properly resolved in the final vS section. A source interval smaller than the spread length will not improve the horizontal resolution because spatial smearing has already been introduced by the receiver spread. In this paper, we first analyze the horizontal resolution of a pair of synthetic traces. Resolution analysis shows that (1) a pair of traces with a smaller receiver spacing achieves higher horizontal resolution of inverted S-wave velocities but results in a larger relative error; (2) the relative error of the phase velocity at a high frequency is smaller than at a low frequency; and (3) a relative error of the inverted S-wave velocity is affected by the signal-to-noise ratio of data. These results provide us with a guideline to balance the trade-off between receiver spacing (horizontal resolution) and accuracy of the inverted S-wave velocity. We then present a scheme to generate a pseudo-2D S-wave velocity section with high horizontal resolution using multichannel records by inverting high-frequency surface-wave dispersion curves calculated through cross-correlation combined with a phase-shift scanning method. This method chooses only a pair of consecutive traces within a shot gather to calculate a dispersion curve. We finally invert surface-wave dispersion curves of synthetic and real-world data. Inversion results of both synthetic and real-world data demonstrate that inverting high-frequency surface-wave dispersion curves - by a pair of traces through cross-correlation with phase-shift scanning method and with the damped least-square method and the singular-value decomposition technique - can feasibly achieve a reliable pseudo-2D S-wave velocity section with relatively high horizontal resolution. ?? 2008 Elsevier B.V. All rights reserved.
Luo, Yinhe; Xia, Jianghai; Liu, Jiangping; Xu, Yixian; Liu, Qingsheng
2008-04-01
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.
Convertito, Vincenzo; Pino, Nicola Alessandro
2014-07-01
Macroseismic intensities are the only available data for most historical earthquakes and often represent the unique source of information for crucial events in the definition of seismic hazard. In this paper, we attempt at getting insight into source characteristics by reproducing the observed intensity field. As a test case, we study the source of 1908 Messina Straits earthquake (MW = 7.1), by testing three distinct fault models deduced from the analysis of geodetic data. Starting from the static slip distribution, we develop kinematic source models for the investigated fault and compute full waveform synthetic seismograms in a 1-D structural model, also accounting for anelastic attenuation. Then, we convert both computed peak-ground acceleration (PGA) and peak-ground velocity (PGV) to macroseismic intensity at 100 selected sites, by means of specific empirical relations for the Italian region. By comparing the original data separately with PGA- and PGV-based intensity fields, we discriminate among the tested faults and determine the best values for the investigated kinematic parameters of the source. We also perform a misfit analysis for the best source model, in order to investigate the dependence of the results on the selected parametrization. The results of the analysis indicate that among the tested models, the one characterized by an east-dipping fault, with strike-oriented NS slightly rotated clockwise, better explains the observed macroseismic field of the 1908 Messina Straits earthquake. Besides, the fracture nucleated at the southern end of the fault and ruptured northward, producing considerable directivity effects. This is in agreement with the published results obtained from the investigation of the historical seismograms. We also determine realistic values for the rupture velocity and the rise-time. Our study confirms the great potential of the macroseismic data, demonstrating that they contain enough information to constrain important characteristics of the fault, which can be retrieved by using complex source models and computing complete wavefield. Moreover, we also show that the simultaneous comparison of both PGA- and PGV-based synthetic macroseismic fields with the original intensities provides tighter constraints for discriminating among different source models, with respect to what attainable from each of them.
Torpey, M.; Ishii, M.
2010-12-01
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.
Directory of Open Access Journals (Sweden)
Bagus Jaya Santosa
2008-11-01
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.
Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods
Energy Technology Data Exchange (ETDEWEB)
Carcione, Jose M [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste (Italy); Helle, Hans B [Norsk Hydro a.s., 0 and E Research Centre, Bergen (Norway); Seriani, Geza [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste (Italy); Plasencia Linares, Milton P [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, La Plata (Argentina)
2005-04-15
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. [Spanish] El algoritmo de modulacion seudoespectral es mejorado y aplicado a la simulacion de sismogramas generados por sismos oceanicos y continentales, como atencion a la atenuacion y a la modelacion explicita de condiciones a la frontera en el fondo oceanico y a la simulacion de la ventana de Rayleigh y la propagacion en interfases. El algoritmo se basa en los operadores diferenciales de Fourier y de Chebyshev con una tecnica de decomposicion de dominios, una malla para el fluido y otra para el solido. Para la propagacion se usa una relacion de esfuerzo-deformacion basada en variables de memoria. Entre los fenomenos modelados se incluyen las ondas de Scholte, las ondas evanescentes de Rayleigh y los modos dispersivos, asi como la ventana de Rayleigh, un minimo del coeficiente de reflexion en el fondo oceanico que nunca ha sido simulado con metodos directos. Hemos modelado los modos de Rayleigh (principalmente M11) y las ondas acopladas Rayleigh-Scholte, resolviendo la relacion de dispersion para casos simples. Se modelo tambien efectos de inhomogeneidades aleatorias en la corteza y manto mediante una funcion de autocovarianza tipo von Karman que simula los efectos de dispersion de ondas. El programa bidimensional permite una variacion material general y una caracterizacion completa y exacta de la respuesta para sismos oceanicos y continentales. Se desarrolla un ejemplo para un sismograma originado en la region del Atlantico Sur.
Gomberg, J.S.; Masters, T.G.
1988-01-01
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
Rock avalanche dynamics evidenced by near-field strongmotion seismogram
Chang, Kuo-Jen; Kuo, Chih-Yu; Chen, Rou-Fei; Chan, Yu-Chang
2010-05-01
Giant landslides have been argued to have some distinctive physical properties such that they can achieve high speed sliding and long runout distance. Although estimating their physical properties is difficult, it is nevertheless crucial for landslide assessments. The idea assessments are from direct measurements when they are at motion. However, due to their scarce occurrences and short flowing durations, they have rarely been instrumentally recorded. In Tsaoling area, Taiwan, there have been historically documented four giant landslides since the late 19th century because of its unique geological condition and, therefore, seismological equipments have been installed around the area since the 90s to monitor the regional seismic activities and its topographic amplification effects. In 1999, Chi-Chi earthquake triggered the fifth major landslide, with a scar volume 0.125 km3. Due to its volume and site locality to the seismic instrument array, the landslide induced ground motion was expected to be captured. We cross examine the records of the surrounding seismic stations and find that only the nearest station, CHY080, exhibits distinguished signatures which may be associated with the landslide. We use the Ensemble Empirical Mode Decomposition (EEMD) to decompose the signals which identify a series of peculiar wave packets. Based on it, a simple rigid sliding model is deployed to analyze the sliding process for physical quantities of the landslide. The results reveal that with the sliding distance 1994 m, the maximum velocity reaches ~ 78 m/s, and the mass generates a large collision impact against the riverbed and the steep slope on the other side of the river. The friction angle of the sliding surface could be estimated and suggested as low as 6.9° so as to achieve a high velocity sliding. These results are agreeable with kinematic simulation of the landslide and provide evidence that the landslide induces seismic ground motion. The revealed results provide a solid evidence and create a new high record for the massive and high speed landslide.
Xie, Yujiang; Liu, Gao
2014-02-01
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.
Ichinose, Gene A.; Thio, Hong Kie; Somerville, Paul G.; Sato, Toshiaki; Ishii, Toru
2003-10-01
We digitized teleseismic and regional records of the 1944 Tonankai earthquake. We used the multiple time window method to invert these records for the spatial and temporal distribution of slip and rake. We assume a 220 × 140 km fault with a spacing of 20 × 20 km and a maximum rupture velocity of 2.5 km/s. The inversion resolved an asperity along the accretionary wedge and under the Shima and Atsumi Peninsulas. The rupture propagated from southwest to northeast, and there was little slip near the hypocenter, consistent with the absence of uplift in the overlying submarine forearc basin. The peak slip is 2.3 m, and the total seismic moment is 2.4 × 1028 dyn cm (Mw 8.2). We compared the predicted and observed vertical geodetic displacements and inferred that the limit of rupture is consistent with the change from subsidence to uplift west of the Atsumi Peninsula. This suggested that the earthquake did not rupture the plate interface in the Tokai gap. We modeled the tsunami using sea-bottom displacements generated from this slip model. The tide gauge amplitudes and frequency content are consistent with those predicted. Resolution tests from inverting synthetic seismograms computed using a simplified slip model indicated that the combination of teleseismic and regional data sets best recovers the asperity locations and peak slips given similar station geometry and degrees of freedom. An inversion of the synthetic regional data set indicates that slip artifacts can occur early in the rupture process due to many clipped records while the inversion of synthetic teleseismic data set had less resolution and recovered only 50% of the peak slip.
Synthetic seismogram images of upper mantle structure: No evidence for a 520-km discontinuity
Bock, Gunter
1994-08-01
Seismological data used by Shearer (1990, 1991) to infer the existence of a seismic discontinuity at 520 km depth are compared with complete long-period body-wave seismographs calculated for the International Association of Seismology and Physics of the Earth's Interior 1991 (Iaspei91) Earth model. The Iaspei91 model does not contain a seismic discontinuity at or near 520 km depth. The observed P and SH multiples caused by topside reflections and SS precursors caused by underside reflections from the 410-km and 660-km discontinuities are well reproduced by the synthetic stacks. The synthetics exhibit clear 'phase extrema' between these reflections that correlate well with similar features in the observed waveform stacks. Shearer interpreted these 'phase extrema' as separate reflections from a seismic discontinuity at 520 km depth. Cross-correlation analysis of synthetic seismograms gives an apparent discontinuity depth of about 520 km for P and SH multiples as well as SS precursors. Similarly, amplitude analysis of synthetic upper mantle reflections is in reasonable agreement with the observations reported by Shearer (1991). The phase extrema seen in the synthetics are the result of an extended, multicycle wavelet which is composed of depth phases and other structural phases such as reverberations from the crustal layer, convolved with the instrument response of long-period stations of the Global Seismograph Network. The comparison of observational data, presented by Shearer (1990, 1991), with the synthetic seismogram stacks of this paper shows that the claim of good seismological evidence for a 520-km seismic discontinuity as a global feature is not compelling.
Wavelet transform analysis of transient signals: the seismogram and the electrocardiogram
Energy Technology Data Exchange (ETDEWEB)
Anant, K.S.
1997-06-01
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.
Dugda, Mulugeta
2010-01-01
In this paper we present two new procedures for automatic detection and picking of P-wave arrivals. The first involves the application of kurtosis and skewness on the vector magnitude of three component seismograms. Customarily, P-wave arrival detection techniques use vertical component seismogram which is appropriate only for teleseismic events. The inherent weakness of those methods stems from the fact that the energy from P-wave is distributed among horizontal and vertical recording channels. Our procedure, however, uses the vector magnitude which accommodates all components. The results show that this procedure would be useful for detecting/picking of P-arrivals from local and regional earthquakes and man-made explosions. The second procedure introduces a new method called "Ratios in Higher Order Statistics (RHOS)." Unlike commonly used techniques that involve derivatives, this technique employs ratios of adjacent kurtosis and skewness values to improve the accuracy of the detection of the P onset. RHOS c...
Yulmetyev, Renat; Gafarov, Fail; Ha?nggi, Peter; Nigmatullin, Raoul; Kayumov, Shamil
2001-01-01
The basic purpose of the paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One of examples of such kind of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). We propose here a discrete stochastic model for possible solution of a problem of strong EQ's forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is...
International Nuclear Information System (INIS)
Many problems of physical interest - for instance, in statistical mechanics - are described by linear ordinary second-order differential systems for which different types of transfer matrices can be introduced and used. Focusing on heterostructures where matching at interfaces is involved, this paper discusses two of them with emphasis on one, here denoted T, which involves the linear differential form expressing the physical quantities matched at the interfaces. The mathematical background is summarized in a simple way and then T is used to study two types of heterostructures involving a large number of interfaces. Firstly, the regular periodic superlattices are studied and the role of different boundary conditions (BCs) at the end of one period is discussed. Only periodic BCs are suitable to study a simple regular superlattices but the discussion provides the background to study different approximants when the period is a largish generation of a quasi-regular heterostructure, like, for instance, a Fibonacci sequence. (author)
Pratt, K. W.; Gurrola, H.
2011-12-01
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.
Rasor, B. A.; Brudzinski, M. R.
2013-12-01
The collision of plates at subduction zones yields the potential for disastrous earthquakes, yet the processes that lead up to these events are still largely unclear and make them difficult to forecast. Recent advancements in seismic monitoring has revealed subtle ground vibrations termed tectonic tremor that occur as long-lived swarms of narrow bandwidth activity, different from local earthquakes of comparable amplitude that create brief signals of broader, higher frequency. The close proximity of detected tremor events to the lower edge of the seismogenic zone along the subduction interface suggests a potential triggering relationship between tremor and megathrust earthquakes. Most tremor catalogs are constructed with detection methods that involve an exhausting download of years of high sample rate seismic data, as well as large computation power to process the large data volume and identify temporal patterns of tremor activity. We have developed a tremor detection method that employs the underutilized Quality Analysis Control Kit (QuACK), originally built to analyze station performance and identify instrument problems across the many seismic networks that contribute data to one of the largest seismogram databases in the world (IRIS DMC). The QuACK dataset stores seismogram amplitudes at a wide range of frequencies calculated every hour since 2005 for most stations achieved in the IRIS DMC. Such a preprocessed dataset is advantageous considering several tremor detection techniques use hourly seismic amplitudes in the frequency band where tremor is most active (2-5 Hz) to characterize the time history of tremor. Yet these previous detection techniques have relied on downloading years of 40-100 sample-per-second data to make the calculations, which typically takes several days on a 36-node high-performance cluster to calculate the amplitude variations for a single station. Processing times are even longer for a recently developed detection algorithm that utilize the ratio of amplitudes between tremor frequencies and those of local earthquakes (10-15 Hz) and surface waves (0.02-0.1 Hz). Using the QuACK dataset, we can make the more advanced calculations in a fraction of the time. This method works well to quickly detect tremor in the Cascadia region by finding similar times of increased tremor activity when comparing across a variety of stations within a 100km radius of a reference station. We confirm the legitimacy of this method by demonstrating comparable results to several previously developed tremor detection techniques despite a much shorter processing time. The rapid processing time has allowed us to refine the detection algorithm by seeking more optimal frequency bands by comparing results from our technique and others, using several stations across the Cascadia subduction zone. As we move forward, we will apply the method to other subduction zones, and ultimately to the vast set of seismic data stored at the IRIS DMC for which tremor has not been previously investigated.
A comparison of two methods for earthquake source inversion using strong motion seismograms
Directory of Open Access Journals (Sweden)
G. C. Beroza
1994-06-01
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.
Study of East Kazakh explosions and propagation in Central Asia using regional Chinese seismograms
Energy Technology Data Exchange (ETDEWEB)
Patton, H.J.; Mills, J.M. Jr.
1984-03-01
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.
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
Development of earthquake early warning system using real time signal of broadband seismogram
Gunawan, Hendar; Puspito, Nanang T.; Ibrahim, Gunawan; Harjadi, Prih
2012-06-01
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.
Development of earthquake early warning system using real time signal of broadband seismogram
Energy Technology Data Exchange (ETDEWEB)
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
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.
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 m 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.
van der Hilst, R. D.; de Hoop, M. V.; Shim, S. H.; Shang, X.; Wang, P.; Cao, Q.
2012-04-01
Over the past three decades, tremendous progress has been made with the mapping of mantle heterogeneity and with the understanding of these structures in terms of, for instance, the evolution of Earth's crust, continental lithosphere, and thermo-chemical mantle convection. Converted wave imaging (e.g., receiver functions) and reflection seismology (e.g. SS stacks) have helped constrain interfaces in crust and mantle; surface wave dispersion (from earthquake or ambient noise signals) characterizes wavespeed variations in continental and oceanic lithosphere, and body wave and multi-mode surface wave data have been used to map trajectories of mantle convection and delineate mantle regions of anomalous elastic properties. Collectively, these studies have revealed substantial ocean-continent differences and suggest that convective flow is strongly influenced by but permitted to cross the upper mantle transition zone. Many questions have remained unanswered, however, and further advances in understanding require more accurate depictions of Earth's heterogeneity at a wider range of length scales. To meet this challenge we need new observations—more, better, and different types of data—and methods that help us extract and interpret more information from the rapidly growing volumes of broadband data. The huge data volumes and the desire to extract more signal from them means that we have to go beyond 'business as usual' (that is, simplified theory, manual inspection of seismograms, …). Indeed, it inspires the development of automated full wave methods, both for tomographic delineation of smooth wavespeed variations and the imaging (for instance through inverse scattering) of medium contrasts. Adjoint tomography and reverse time migration, which are closely related wave equation methods, have begun to revolutionize seismic inversion of global and regional waveform data. In this presentation we will illustrate this development - and its promise - drawing from our work on inverse scattering of reflected SS and ScS/SKKS wavefields and reverse time migration of converted P and S waves. With SS and the wave conversions we study the upper mantle transition zone and with ScS/SKKS we image complex structures near the base of the mantle.
1-D neutronics optimization design for ITER CH HCSB TBM
International Nuclear Information System (INIS)
The neutronics problem of the TBM module design connects closely with TBM's other problems, such as, tritium generation, thermo-hydraulic, safety, etc. An exact neutronics calculation for the TBM module is very important. Based on the 1-D calculation model given in the CH HCSB TBM design, a better 1-D neutronics optimization has been performed using the ONEDANT code with related database. (authors)
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
1D Copper Nanostructures: Progress, Challenges and Opportunities.
Bhanushali, Sushrut; Ghosh, Prakash; Ganesh, Anuradda; Cheng, Wenlong
2015-03-01
One-dimensional noble metal nanostructures are important components in modern nanoscience and nanotechnology due to their unique optical, electrical, mechanical, and thermal properties. However, their cost and scalability may become a major bottleneck for real-world applications. Copper, being an earth-abundant metallic element, is an ideal candidate for commercial applications. It is critical to develop technologies to produce 1D copper nanostructures with high monodispersity, stability and oxygen-resistance for future low-cost nano-enabled materials and devices. This article covers comprehensively the current progress in 1D copper nanostructures, most predominantly nanorods and nanowires. First, various synthetic methodologies developed so far to generate 1D copper nanostructures are thoroughly described; the methodologies are in conjunction with the discussion of microscopic, spectrophotometric, crystallographic and morphological characterizations. Next, striking electrical, optical, mechanical and thermal properties of 1D copper nanostructures are highlighted. Additionally, the emerging applications of 1D copper nanostructures in flexible electronics, transparent electrodes, low cost solar cells, field emission devices are covered, amongst others. Finally, there is a brief discussion of the remaining challenges and opportunities. PMID:25504816
Predicting Lg Coda Using Synthetic Seismograms and Media With Stochastic Heterogeneity
Tibuleac, I. M.; Stroujkova, A.; Bonner, J. L.; Mayeda, K.
2005-12-01
Recent examinations of the characteristics of coda-derived Sn and Lg spectra for yield estimation have shown that the spectral peak of Nevada Test Site (NTS) explosion spectra is depth-of-burial dependent, and that this peak is shifted to higher frequencies for Lop Nor explosions at the same depths. To confidently use coda-based yield formulas, we need to understand and predict coda spectral shape variations with depth, source media, velocity structure, topography, and geological heterogeneity. We present results of a coda modeling study to predict Lg coda. During the initial stages of this research, we have acquired and parameterized a deterministic 6 deg. x 6 deg. velocity and attenuation model centered on the Nevada Test Site. Near-source data are used to constrain density and attenuation profiles for the upper five km. The upper crust velocity profiles are quilted into a background velocity profile at depths greater than five km. The model is parameterized for use in a modified version of the Generalized Fourier Method in two dimensions (GFM2D). We modify this model to include stochastic heterogeneities of varying correlation lengths within the crust. Correlation length, Hurst number and fractional velocity perturbation of the heterogeneities are used to construct different realizations of the random media. We use nuclear explosion and earthquake cluster waveform analysis, as well as well log and geological information to constrain the stochastic parameters for a path between the NTS and the seismic stations near Mina, Nevada. Using multiple runs, we quantify the effects of variations in the stochastic parameters, of heterogeneity location in the crust and attenuation on coda amplitude and spectral characteristics. We calibrate these parameters by matching synthetic earthquake Lg coda envelopes to coda envelopes of local earthquakes with well-defined moments and mechanisms. We generate explosion synthetics for these calibrated deterministic and stochastic models. Secondary effects, including a compensated linear vector dipole source, are superposed on the synthetics in order to adequately characterize the Lg generation. We use this technique to characterize the effects of depth of burial on the coda spectral shapes.
Anne Cox
2014-06-05
The Introductory Physics 1D Motion Lab asks students to develop a computer model for a ball moving vertically under the influence of gravity. When the file is opened, it is initially programmed with a mass moving at constant velocity. It is assumed that students have first collected data of a basketball or volleyball bouncing under a motion detector. The lab instructions fully explain how to build the computer model using Easy Java Simulations modeling tool. The students will learn how to modify the model to simulate a bouncing ball, define variables, calculate relationships, and change the properties for plotting the graph. The calculus is done for the student. Editor's Note: The Easy Java Simulation tool greatly reduces the amount of programming required to develop computer models. Exercises in student-generated modeling are becoming much more widespread in physics education because of the opportunities for students to test and apply their own prototypes to explain and predict physical phenomena. This resource is distributed as a ready-to-run (compiled) Java archive. In order to modify the simulation (and see how it is designed), users must install the Easy Java Simulations Modeling and Authoring Tool. SEE RELATED MATERIALS for a link to install the EJS modeling tool.
Saikia, C. K.; Roman-nieves, J. I.; Woods, M. T.
2013-12-01
Source parameters of nuclear and chemical explosions are often estimated by matching either the corner frequency and spectral level of a single event or the spectral ratio when spectra from two events are available with known source parameters for one. In this study, we propose an alternative method in which waveforms from two or more events can be simultaneously equalized by setting the differential of the processed seismograms at one station from any two individual events to zero. The method involves convolving the equivalent Mueller-Murphy displacement source time function (MMDSTF) of one event with the seismogram of the second event and vice-versa, and then computing their difference seismogram. MMDSTF is computed at the elastic radius including both near and far-field terms. For this method to yield accurate source parameters, an inherent assumption is that green's functions for the any paired events from the source to a receiver are same. In the frequency limit of the seismic data, this is a reasonable assumption and is concluded based on the comparison of green's functions computed for flat-earth models at various source depths ranging from 100m to 1Km. Frequency domain analysis of the initial P wave is, however, sensitive to the depth phase interaction, and if tracked meticulously can help estimating the event depth. We applied this method to the local waveforms recorded from the three SPE shots and precisely determined their yields. These high-frequency seismograms exhibit significant lateral path effects in spectrogram analysis and 3D numerical computations, but the source equalization technique is independent of any variation as long as their instrument characteristics are well preserved. We are currently estimating the uncertainty in the derived source parameters assuming the yields of the SPE shots as unknown. We also collected regional waveforms from 95 NTS explosions at regional stations ALQ, ANMO, CMB, COR, JAS LON, PAS, PFO and RSSD. We are currently employing a station based analysis using the equalization technique to estimate depth and yields of many relative to those of the announced explosions; and to develop their relationship with the Mw and Mo for the NTS explosions.
Larmat, C.; Montagner, J.-P.; Capdeville, Y.; Banerdt, W. B.; Lognonné, P.; Vilotte, J.-P.
2008-07-01
The past 4 decades of Mars exploration have provided much information about the Mars surface, when its interior structure remains relatively poorly constrained. Today available data are compatible with a large range of model parameters. Seismology is able to provide valuable additional data but the number of seismographs will likely be quite limited, specially in the early-stage of future Mars seismic networks. It is thus of importance to be able to correctly isolate effects induced by the crust structure. Mars topography is characterized by spectacular reliefs like the Tharsis bulge or the Hellas basin and by the so-called "Mars dichotomy": the north hemisphere is made up of low-altitude plains above a relatively thin crust when the south hemisphere is characterized by a thick crust sustaining high reliefs. The aim of this paper is to study the effects induced on seismograms by the topography of the surface and crust-mantle discontinuities. Synthetic seismograms were computed using the coupled spectral element-modal solution method, which reduces the numerical cost by limiting the use of the spectral element method to the regions where lateral variations, like the presence of a topography, are considered. Due to numerical cost, this study is limited to long period and thus focuses on surface waves, mainly on long period Rayleigh waves. We show that reliefs like the Tharsis bulge or the Hellas basin can induce an apparent velocity anomaly up to 0.5% when only the surface topography is introduced. Apparent anomalies can raise up to 1.0% when the surface topography is fully compensated by a mirror-image topography of the crust-mantle discontinuity. Travel-time of surface wave are systematically increased for seismometers in the north hemisphere of Mars and decreased in the south hemisphere. When comparing effects on seismograms by the Earth and Mars topography, we found them to be larger for the Earth. It is due to the fact that we work with a seismic velocity model of Mars with a mean crust thickness of 110 km when the crust thickness has a mean value of 50 km for the Earth. When changing the Mars model for a thinner crust with a mean thickness of 50 km, effects by the topography on Mars seismograms becomes of the same order when not larger than what is observed on the Earth.
Social exploration of 1D games
DEFF Research Database (Denmark)
Valente, Andrea; Marchetti, Emanuela
2013-01-01
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.
Yulmetyev, Renat; Gafarov, Fail; Hänggi, Peter; Nigmatullin, Raoul; Kayumov, Shamil
2001-12-01
The basic scientific point of this paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One example of such kinds of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). EQ's are among the most dramatic phenomena in nature. We propose here a discrete stochastic model for possible solution of a problem of strong EQ forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is performed by two independent methods: by using statistical theory of discrete non-Markov stochastic processes [Phys. Rev. E 62, 6178 (2000)] and the local Hurst exponent. The following Earth states have been considered among them: before (Ib) and during (I) strong EQ, during weak EQ (II) and during TE (III), and in a calm state of Earth's core (IV). The estimation of states I, II, and III has been made on the particular examples of Turkey (1999) EQ's, state IV has been taken as an example of Earth's state before underground TE. Time recordings of seismic signals of the first four dynamic orthogonal collective variables, six various planes of phase portrait of four-dimensional phase space of orthogonal variables and the local Hurst exponent have been calculated for the dynamic analysis of states of systems I-IV. The analysis of statistical properties of seismic time series I-IV has been realized with the help of a set of discrete time-dependent functions (time correlation function and first three memory functions), their power spectra, and the first three points in the statistical spectrum of non-Markovity parameters. In all systems studied we have found a bizarre combination of the following spectral characteristics: the fractal frequency spectra adjustable by phenomena of usual and restricted self-organized criticality, spectra of white and color noises and unusual alternation of Markov and non-Markov effects of long-range memory, detected earlier [J. Phys. A 27, 5363 (1994)] only for hydrodynamic systems. Our research demonstrates that discrete non-Markov stochastic processes and long-range memory effects play a crucial role in the behavior of seismic systems I-IV. The approaches, permitting us to obtain an algorithm of strong EQ forecasting and to differentiate TE's from weak EQ's, have been developed.
Earthquake source scaling relationships from -1 to 5 ML using seismograms recorded at 2.5-km depth
Abercrombie, Rachel E.
1995-12-01
The scaling relationships of earthquake sources less than about magnitude 3 have been the subject of considerable controversy over the last two decades. Studies of such events have shown a tendency for the constant stress drop, self similarity of larger earthquakes to breakdown at small magnitudes, and an apparent minimum source dimension of about 100 m has been observed. Other studies showed that this apparent breakdown in scaling could be an artifact of severe near-surface attenuation, limiting the spatial resolution of surface data. In this study, source parameters are determined for over 100 nearby, tectonic earthquakes, from recordings at a depth of 2.5 km (in granite) in the Cajon Pass scientific drill hole, southern California. Comparison of the seismograms recorded at this depth with those at the wellhead clearly demonstrates the effect of the severe attenuation in the upper kilometers of the Earth's crust. Source parameters are calculated by spectral modeling of three-component P and S waves, assuming four source models based on the Brune ?-2 (n = 2) model. In model l, n = 2 is fixed, and Q of P and S waves is determined to be 912 (581-1433) and 1078 (879-1323), respectively (the numbers in parentheses are ±1 standard deviation). In model 2, QP = QS = 1000 is assumed and n is allowed to vary. The ?-2 model is a good average for the data set, but there is some real scatter supported by the data. In model 3, QP = QS = 1000 is also assumed and ?-2 is constrained, and in model 4, attenuation is ignored and n is allowed to vary. Source dimensions of less than 10m are observed for all four models, 10 times smaller than the proposed "minimum". No breakdown in constant stress drop scaling is seen in the downhole data (approximately ML-1 to 5.5, M0 = 109 - 1016 Nm). The ratio between radiated seismic energy (estimated by integrating the velocity squared spectra with adequate signal bandwidth) and seismic moment appears to decrease gradually with decreasing moment in the magnitude range -1 to 7. This is not incompatible with a constant stress drop but could result from errors in calculating energy. The ratio of the S wave energy to that radiated by the P waves is about 14, after correction for attenuation. This low value is consistent with the corner frequency shift of about 1.3. This corner frequency shift is observed for all four source models and therefore is interpreted as being source controlled.
Esker, D.; Sheridan, R.E.; Ashley, G.M.; Waldner, J.S.; Hall, D.W.
1996-01-01
A new technique, using empirical relationships between median grain size and density and velocity to calculate proxy values for density and velocity, avoids many of the problems associated with the use of well logs and shipboard measurements to construct synthetic seismograms. This method was used to groundtruth and correlate across both analog and digital shallow high-resolution seismic data on the New Jersey shelf. Sampling dry vibracores to determine median grain size eliminates the detrimental effects that coring disturbances and preservation variables have on the sediment and water content of the core. The link between seismic response to lithology and bed spacing is more exact. The exact frequency of the field seismic data can be realistically simulated by a 10-20 cm sampling interval of the vibracores. The estimate of the percentage error inherent in this technique, 12% for acoustic impedance and 24% for reflection amplitude, is calculated to one standard deviation and is within a reasonable limit for such a procedure. The synthetic seismograms of two cores, 4-6 m long, were used to correlate specific sedimentary deposits to specific seismic reflection responses. Because this technique is applicable to unconsolidated sediments, it is ideal for upper Pleistocene and Holocene strata. Copyright ?? 1996, SEPM (Society for Sedimentary Geology).
Sawada, Hiroyuki
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.
Bethe Ansatz for 1D interacting anyons
Batchelor, M T; He, J S
2006-01-01
This article gives a pedagogic derivation of the Bethe Ansatz solution for 1D interacting anyons. This includes a demonstration of the subtle role of the anyonic phases in the Bethe Ansatz arising from the anyonic commutation relations. The thermodynamic Bethe Ansatz equations defining the temperature dependent properties of the model are also derived, from which some groundstate properties are obtained.
Measurement of persistence in 1-D diffusion
Wong, G P; Walsworth, R L; Cory, D G; Wong, Glenn P.; Mair, Ross W.; Walsworth, Ronald L.; Cory, David G.
2001-01-01
Using a novel NMR scheme we observed persistence in 1-D gas diffusion. Analytical approximations and numerical simulations have shown that for an initially random array of spins undergoing diffusion, the probability p(t) that the average spin orientation in a given region has not changed sign (i.e., ``persists'') up to time t follows a power law t^{-\\theta}, where \\theta depends on the dimensionality of the system. The large nuclear spin polarization of laser-polarized 129Xe gas allowed us both to prepare an initial ``quasi-random'' 1-D array of spin orientations and then to perform real-time NMR imaging to monitor the spin diffusion. Our measurements are consistent with theoretical and numerical predictions of \\theta ~ 0.12. We also observed finite size effects for long time gas diffusion.
Brokešová, Johana; Málek, Ji?í
2015-02-01
Near-source records obtained by the mechanical seismic sensor Rotaphone are presented. The Rotaphone can measure six components of seismic movements, three translational and three rotational. The apparent S-wave phase velocity is determined and the possibility to obtain the wavepath S-wave velocity directly under the receiver is discussed. Rotation-to-translation ratios (RTRs) characterize the strength of rotations compared to translations. The Rotaphone records of local microearthquakes were obtained in various European seismoactive regions over the last few years. Three case studies, analyzed in detail, include various geological structures and seismograms recorded at various epicentral distances from 0.7 to 14.9 km. Also, the source depth varies from 4.8 to 10.4 km. The first case is an event from the West Bohemia intraplate seismic swarm region. The seismogram was recorded only 0.7 km from the epicenter. This case shows the complexity of rotation-to-translational relations near the epicenter. The second case is from the Corinthian Gulf active-rift region. The study confirms the expectation of the theory concerning rotations connected with the direct S wave; however, difficulties follow from a very complex 3D geological structure in the vicinity of the station, complicated by a distinctive topography with steep slopes of the hills. The third example is from South Iceland, near the active Katla volcano. The data in this case satisfy the rotation-to-translation relations very well, which is probably caused by the relatively simple geological setting and appropriate source-to-receiver configuration. The RTRs are computed for all three cases, and their frequency dependence is discussed.
Wang, Y.; Forsyth, D. W.; Savage, B.
2010-12-01
In our previous surface wave study in Gulf of California area, we developed a moderate-resolution 3D shear velocity model by employing two-plane wave field representation array technique and 2D finite frequency kernels based on Born’s approximation. Using both amplitude and phase information of 22-111s teleseismic Rayleigh wave, we were able to constrain a lateral resolution on the order of 100 km in the upper 160 km depth. In order to enhance resolution beneath the highly heterogeneous Gulf region, we carry on further study using Spectral element method (SEM) for forward wave propagation simulation and adjoint method for tomographic inversion. The code we are using is SPECFEM3D_GLOBE by Komatitsch and Tromp et al. To enhance the resolution in the Gulf, we will minimize the waveform difference between the regional earthquake seismograms, recorded by NARS-Baja seismic array and stations in southern California, and synthetic seismograms simulated by SEM, to iteratively update the current model based on an adjoint inversion. Taking our current 3D moderate-resolution model as starting point and a recently developed crustal structure of Gulf region should help to reduce the number of iterations. There are two reasons that resolution should be enhanced compared to surface wave tomography: first, regional events contain more high frequency signals than teleseismic events; second, SEM is a full waveform synthesis method avoiding many of the usual approximations in tomographic studies. Improved tomographic images of 3D velocity heterogeneities in the upper mantle of Gulf of California will help to identify compositional and temperature variations, leading to a better understanding of mantle dynamics in the region.
Brokešová, Johana; Málek, Ji?í
2015-04-01
Near-source records obtained by the mechanical seismic sensor Rotaphone are presented. The Rotaphone can measure six components of seismic movements, three translational and three rotational. The apparent S-wave phase velocity is determined and the possibility to obtain the wavepath S-wave velocity directly under the receiver is discussed. Rotation-to-translation ratios (RTRs) characterize the strength of rotations compared to translations. The Rotaphone records of local microearthquakes were obtained in various European seismoactive regions over the last few years. Three case studies, analyzed in detail, include various geological structures and seismograms recorded at various epicentral distances from 0.7 to 14.9 km. Also, the source depth varies from 4.8 to 10.4 km. The first case is an event from the West Bohemia intraplate seismic swarm region. The seismogram was recorded only 0.7 km from the epicenter. This case shows the complexity of rotation-to-translational relations near the epicenter. The second case is from the Corinthian Gulf active-rift region. The study confirms the expectation of the theory concerning rotations connected with the direct S wave; however, difficulties follow from a very complex 3D geological structure in the vicinity of the station, complicated by a distinctive topography with steep slopes of the hills. The third example is from South Iceland, near the active Katla volcano. The data in this case satisfy the rotation-to-translation relations very well, which is probably caused by the relatively simple geological setting and appropriate source-to-receiver configuration. The RTRs are computed for all three cases, and their frequency dependence is discussed.
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.
1D oxide nanostructures from chemical solutions.
Einarsrud, Mari-Ann; Grande, Tor
2014-04-01
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
Weinshank, R. L.; Zgombick, J. M.; Macchi, M. J.; Branchek, T. A.; Hartig, P. R.
1992-01-01
The serotonin 1D (5-HT1D) receptor is a pharmacologically defined binding site and functional receptor site. Observed variations in the properties of 5-HT1D receptors in different tissues have led to the speculation that multiple receptor proteins with slightly different properties may exist. We report here the cloning, deduced amino acid sequences, pharmacological properties, and second-messenger coupling of a pair of human 5-HT1D receptor genes, which we have designated 5-HT1D alpha and 5-H...
The Role of O(1D) in the Oxidation of Si(100)
International Nuclear Information System (INIS)
Oxidation of silicon with neutral atomic oxygen species generated in a rare gas plasma has recently been shown to produce high-quality thin oxides. It has been speculated that atomic oxygen in the first excited state, O(1D), is a dominant reactive species in the oxidation mechanism. In this study, we investigate the role of O(1D) in silicon oxidation in the absence of other oxidizing species. The O(1D) is generated by laser-induced photodissociation of N2O at 193 nm. We find that, at 400?C, O(1D) is effective in the initial stages of oxidation, but the oxide growth rate falls dramatically past 1.5 nm. Oxide films thicker than 2 nm were unachievable regardless of oxidation time or N2O partial pressure (0.5-90 mTorr), indicating O(1D) cannot be a dominant reactive species in thicker oxidation mechanisms. We suggest that quenching of O(1D) to O(3P) (ground state) during diffusion through thicker oxides results in drastically slower oxidation kinetics. In contrast, oxidation with a vacuum ultraviolet (VUV) excimer lamp operating at 172 nm resulted in oxide thicknesses up to 4 nm. Thus, other species produced in plasmas and excimer lamps, such as molecular and atomic ions, photons, and free and conduction band electrons, play a dominant role in the rapid oxidation mechanism of thicker oxides (> 2 nm)
Synthesis of magnetic 1D dichalcogenide nanostructures
Energy Technology Data Exchange (ETDEWEB)
Kidd, Timothy E., E-mail: tim.kidd@uni.edu; O' Shea, Aaron; Griffith, Zach; Leslie, Stroh; Shand, Paul M. [University of Northern Iowa, Physics Department (United States); Boyle, Kayla R.; Strauss, Laura H. [University of Northern Iowa, Chemistry and Biochemistry Department (United States)
2012-06-15
We report the first synthesis of magnetic one-dimensional transition metal dichalcogenides. Pure and Mn-doped tantalum disulfide nanotapes were synthesized using a catalyst-free single-step growth process. The sample yield of nanostructures was nearly 100 %. The nanotapes were composed of a number of smaller nanowires which appear to be open-ended nanotubes. The smaller nanowires have diameters ranging from about 30 to 300 nm. The Mn dopants were incorporated within intercalation sites between TaS{sub 2} layers. Interactions between these dopant ions induced low temperature magnetic phase transitions similar to those seen in macroscopic Mn{sub x}TaS{sub 2} compounds. The magnetic properties do not exactly correspond to their bulk counterparts, as exemplified by a higher than expected ferromagnetic transition temperature in 1D nanostructures. This indicates the magnetic properties are likely influenced by quantum size effects. The simplicity of this one-step synthesis method should allow for this technique to be extended to other dichalcogenide systems and/or magnetic dopants, opening up a new class of 1D magnetic nanostructures.
GPU accelerated CESE method for 1D shock tube problems
Ran, Wei; Cheng, Wan; Qin, Fenghua; Luo, Xisheng
2011-10-01
In the present study, a GPU accelerated 1D space-time CESE method is developed and applied to shock tube problems with and without condensation. We have demonstrated how to implement the CESE algorithm to solve 1D shock tube problems using an older generation GPU (the NVIDIA 9800 GT) with relatively limited memory. To optimize the code performance, we used Shared Memory and solved the inter-Block boundary problem in two ways, namely the branch scheme and the overlapping scheme. The implementations of these schemes are discussed in detail and their performances are compared for the Sod shock tube problems. For the Sod problem without condensation, the speedup over an Intel CPU E7300 is 23 for the branch scheme and 41 for the overlapping scheme, respectively. While for problems with condensation, both schemes achieve higher acceleration ratios, 53 and 71, respectively. The higher speedup of the condensation case can be ascribed to the source term calculation which has a local dependence on the mesh point and the SOURCE kernel has a higher acceleration ratio.
Plicka, Vladimir; Zahradnik, Jiri
2013-04-01
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.
'A Civil Action' 1-D Transport Game
Scott Bair
The 'A Civil Action' 1-D Contaminant Transport Game is an EXCEL spreadsheet that enables students to compute concentrations of TCE traveling in the groundwater flow system toward well H that emanate from the W.R. Grace site. The idea of the game is to draw students into learning some of the fundamental concepts about (1) how contaminants move in the subsurface and (2) how models can be used to test hypotheses. These concepts are taught within the context of the famous 'A Civil Action' trial described in the book by Jonathan Harr (1996) and the movie starring John Travolta (1998). The spreadsheet computes values of hydraulic head, advective flow velocities and traveltimes, contaminant velocities, and contaminant concentrations at 20 locations along the flowpath from W.R. Grace to the Aberjona River. Breakthrough curves showing changes in concentration versus distance and changes in concentration versus time pop-up automatically (see below). The spreadsheet also creates graphs of advective and contaminant velocities versus distance.
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
Basarir, Nilay; Meral Ozel, Nurcan
2013-04-01
Marmara Region has witnessed many destructive earthquakes where some of them caused tsunami. Examination of these earthquakes through analyzing of analog records is crucial for the interpretation of seismotectonics and to assess the level of seismic hazard in this region. Many geological field surveys and geophysical studies to date indicated that 1912, Sarkoy-Murefte event, occurred on the Ganos Fault Zone, was one of the largest earthquake in the western Marmara Sea and caused tsunami. The same is also valid for 04.01.1935, 14:41, M=6.4 and 16:20 M=6.3 Erdek-Marmara Island, and 18.09.1963, 1963, M=6.3 Cinarcik Earthquakes. The purpose of this study is to contribute to the seismotectonics of this region by examining these earthquakes and revaluate source parameters of these shocks using seismic waveforms, which were previously not carried out by modern techniques. In this study, the original seismograms from various countries for 1912 Sarköy-Mürefte, 1935, Erdek Marmara Island and 1963, Cinarcik Earthquakes were digitized. The magnitude Mw, seismic moment Mo, the radius of circular source zone R and stress drop ?? values were redetermined using digitized original seismic waveforms from displacement spectra for these historical events. For this purpose, a large number of seismic station bulletins have been consulted for the instrumental information to remove the instrument response. In addition, the epicentral locations have been calculated using available readings from original records and also ISS bulletins for 04.01.1935-14:41 and 16:20 Marmara Island-Erdek Earthquake and 18.09.1963-16:58 Cinarcik Earthquake. For the 1912 event, the magnitude Mw=7.13 and radius of the fault area R=41 km were determined. Also, 04.01.1935- 14:41 and 16:20 Earthquakes showed a fault radius of about 15 km with magnitudes Mw=6.0 and Mw=5.9, respectively. The epicenter determinations showed that the first event in 04.01.1935 was located at 40.72 N- 27.72 E while the second one occurred at 40.61 N-27.43 E. Another finding is of the 1963 event, which gave a fault radius of approximately 13 km with a magnitude Mw=5.9. The 1963 event was located at 40.80 N-29.18 E. Furthermore; moment tensor inversion method was applied on these earthquakes by using original seismograms collected from various observatories. The fault mechanisms for 04.01.1935-14:41 and 16:20 Earthquakes were determined using moment tensor inversion from the original seismic waveforms for the first time. Likewise, fault mechanism for the 1963 Cinarcik Earthquake was also obtained. The results showed that these earthquakes have normal fault mechanism. The application of moment tensor inversion method to the historical earthquakes records will give an opportunity to understand the geometry of the known faults possibly shed light some unknown structures and illuminate the seismotectonic features of Marmara Region based on the retrieved fault mechanism solution.
Basarir, N.; Meral Ozel, N.
2013-12-01
Marmara Region has witnessed many devastating earthquakes where some of them caused tsunami. Examination of these earthquakes through analyzing of analog records is crucial for the interpretation of seismotectonics and to assess the level of seismic hazard in this region. To date, many geological field surveys and geophysical studies indicated that 1912, Sarkoy-Murefte event, occurred on the Ganos Fault Zone, was one of the largest earthquake in the western Marmara Sea and caused tsunami. The same is also valid for 04.01.1935, 14:41, M=6.4 and 16:20 M=6.3 Erdek-Marmara Island, and 18.09.1963, 1963, M=6.3 Cinarcik Earthquakes. The aim of this study is to contribute to the seismotectonics of this region by examining these earthquakes and revaluate source parameters of these shocks using seismic waveforms, which were previously not carried out by modern techniques. In this study, the original seismograms from various countries for 1912 Sarköy-Mürefte, 1935, Erdek Marmara Island and 1963, Cinarcik Earthquakes were digitized. The magnitude Mw, seismic moment Mo, the radius of circular source zone R and stress drop values were redetermined using digitized original seismic waveforms from displacement spectra for these historical events. For this purpose, a large number of seismic station bulletins have been consulted for the instrumental information to remove the instrument response. In addition, the epicentral locations have been calculated using available readings from original records and also ISS bulletins for 04.01.1935-14:41 and 16:20 Marmara Island-Erdek Earthquake and 18.09.1963-16:58 Cinarcik Earthquake. For the 1912 event, the magnitude Mw=7.13 and radius of the fault area R=41 km were determined. Also, 04.01.1935- 14:41 and 16:20 Earthquakes showed a fault radius of about 15 km with magnitudes Mw=6.0 and Mw=5.9, respectively. The epicenter determinations showed that the first event in 04.01.1935 was located at 40.72 N- 27.72 E while the second one occurred at 40.61 N-27.43 E. Another finding is of the 1963 event, which gave a fault radius of approximately 13 km with a magnitude Mw=5.9. The 1963 event was located at 40.80 N-29.18 E. Furthermore; moment tensor inversion method was applied on these earthquakes by using original seismograms collected from various observatories. The fault mechanisms for 04.01.1935-14:41 and 16:20 Earthquakes were determined using moment tensor inversion from the original seismic waveforms for the first time. Likewise, fault mechanism for the 1963 Cinarcik Earthquake was also obtained. The results showed that these earthquakes have normal fault mechanism. The application of moment tensor inversion method to the historical earthquakes records will give an opportunity to understand the geometry of the known faults possibly shed light some unknown structures and illuminate the seismotectonic features of Marmara Region based on the retrieved fault mechanism solution.
Weinshank, R L; Zgombick, J M; Macchi, M J; Branchek, T A; Hartig, P R
1992-01-01
The serotonin 1D (5-HT1D) receptor is a pharmacologically defined binding site and functional receptor site. Observed variations in the properties of 5-HT1D receptors in different tissues have led to the speculation that multiple receptor proteins with slightly different properties may exist. We report here the cloning, deduced amino acid sequences, pharmacological properties, and second-messenger coupling of a pair of human 5-HT1D receptor genes, which we have designated 5-HT1D alpha and 5-HT1D beta due to their strong similarities in sequence, pharmacological properties, and second-messenger coupling. Both genes are free of introns in their coding regions, are expressed in the human cerebral cortex, and can couple to inhibition of adenylate cyclase activity. The pharmacological binding properties of these two human receptors are very similar, and match closely the pharmacological properties of human, bovine, and guinea pig 5-HT1D sites. Both receptors exhibit high-affinity binding of sumatriptan, a new anti-migraine medication, and thus are candidates for the pharmacological site of action of this drug. Images PMID:1565658
Garg, Monika; Elamein, Hala M M; Tanaka, Hiroyuki; Tsujimoto, Hisashi
2007-10-01
Alien chromosome addition lines are useful genetic material for studying the effect of an individual chromosome in the same genetic background. However, addition lines are sometimes unstable and tend to lose the alien chromosome in subsequent generations. In this study, we report preferential removal of chromosome 1D rather than the alien chromosome from homoeologous group-1 addition lines. The Agropyron intermedium chromosome 1Agi (1E) addition line, created in the background of 'Vilmorin 27', showed loss of a part of chromosome 1D, thereby losing its HMW glutenin locus. Even in the case of Aegilops longissima and Ae. peregrina, the genomes of which are closer to the B genome than D genome, chromosome 1D was lost from chromosome 1Sl and 1Sv addition lines in cv. 'Chinese Spring' rather than chromosome 1B during transfer from one generation to another. A similar observation was also observed in the case of a chromosome 1E disomic addition line of Ag. elongatum and alloplasmic common wheat line with Ag. intermedium ssp. trichophorum cytoplasm. The reason for this strange observation is thought to lie in the history of wheat evolution, the size of chromosome 1D compared to 1A and 1B, or differing pollen competition abilities. PMID:17991995
Vlasov-Poisson in 1D: waterbags
Colombi, Stéphane
2014-01-01
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...
Vlasov-Poisson in 1D: waterbags
Colombi, Stéphane; Touma, Jihad
2014-07-01
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.
Hemi-omnidirectional lasing from a cholesteric liquid crystal layer on a 1D photonic crystal film
International Nuclear Information System (INIS)
We herein report on a hybrid photonic band gap (PBG) system, which was fabricated using a cholesteric liquid crystal (CLC) layer on a 1-dimensional (1D) photonic crystal (PC) film, i.e., hybrid 'CLC/1D PC'. The CLC layer is made of nematic liquid crystal monomers embedded in polymeric helical CLC networks, thereby exhibiting a field-induced reorientational undulation of the helical axis. It is shown that intensity-controllable circularly polarized laser emissions may be generated at the wavelength of the high-energy band edge mode of the CLC layer in the dye-doped 'CLC/1D PC' PBG structure. The handedness of the lasing light corresponds to the handedness of the CLC layer used. Moreover, the direction of propagation of laser emissions could be manipulated from uni- to hemi-omnidirectional for the hybrid 'CLC/1D PC' PBG structure by applying an electric field.
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)
Lifescience Database Archive (English)
Full Text Available 1D6R ?? Soybean Glycine max (L.) Merrill Bowman-Birk Type Proteinase Inhibitor Precursor Glyci ... Warkentin, G.Wenzl, P.Flecker Crystal Structure Of Cancer ... Chemopreventive Bowman-Birk Inhibitor In Ternary C ...
Spectral decomposition of 1D Fokker - Planck differential operator
Tanski, Igor A.
2006-01-01
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].
Hauksson, E.; Chi, W.; Shearer, P.
2003-12-01
We present preliminary results applying waveform cross-correlation to southern California seismograms for over 380,000 events between 1984 and 2002. Waveforms recorded by the SCSN are first extracted from the SCEDC data center in 50 s windows that include both P and S waves. The resulting online waveform archive uses about 0.5 TB on a RAID system. The traces are then re-sampled to a uniform 100 Hz sample rate and band-pass filtered to between 1 and 10 Hz. Next, we apply time domain waveform cross-correlation for P and S waves between each event and 100 neighboring events (identified from the catalog based on a 3-D velocity model of Hauksson (2000). We identify and save differential times from the peaks in the cross-correlation functions and use a spline interpolation method to achieve a nominal timing precision of 0.001 s. These differential times, together with existing P and S phase picks, are input to the double-difference program of Waldhauser and Ellsworth (2000). We define a grid across southern California and locate hypocenters near each grid node. Because some events may be located many times as hypocenters are calculated near successive grid-points, we assign a weight to each hypocenter and calculate a weighted average hypo-center for each earthquake. The new HypoDD hypocenters show improved clustering both horizontally and vertically, creating a more focused picture of the previously identified, spatially complex distributions of seismicity. In many cases, the late Quaternary faults, such as the Elsinore and Hollywood-Santa Monica faults appear to bracket the seismicity distributions; in other cases, the faults trace the median within a symmetric distribution of hypocenters. The depth distribution of the seismicity shows sudden changes across some of the major strike-slip faults, while regions of dip-slip faulting are often bound by dipping surfaces that are clearly defined by the deepest hypocenters. The seismicity around the southern San Andreas fault shows clear alignment along the Carrizo Plain segment while both the Mojave and Coachella Valley segments are dominated by off-fault hypocenters. A prominent horizontal boundary striking a few degrees north of west with a prominent depth change in the seismicity cuts across Banning Pass towards San Bernardino. Earthquake swarms in the Salton Sea at the south end of the San Andreas fault suggest the presence of two north-northwest striking seismic zones at the south end of the San Andreas fault. The seismicity along the San Jacinto fault forms sharp alignments that in most cases are adjacent to, but not coincident with, the mapped surface traces that are either parallel to the traces or form high angles to them. In the Los Angeles basin, the major aftershock sequences appear as densely focused clusters within a cloud of scattered background seismicity. The seismicity along the Newport-Inglewood fault forms a sharp alignment to the north and a diffuse distribution to the south, where the 1933 Long Beach earthquake occurred. Similarly, several clusters as well as scattered background seismicity extending from east to west across the basin illuminate the blind thrusts beneath the north edge of the basin. The major aftershock sequences such as 1992 Landers, 1994 Northridge, and 1999 Hector Mine form clusters, with distinct internal structures, illuminating secondary faults and a heterogeneous main fault rupture surface. Some of these alignments suggest that high angle cross-faults were activated by the mainshock.
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
Time-Resolved 1-D X-ray Imaging Technique for Z-Pinch Plasma Diagnosis
Yang, J. L.; Li, Z. H.; Xu, R. K.; Li, L. B.; Ning, J. M.; Guo, C.; Song, F. J.; Xu, Z. P.; Xia, G. X.
2006-01-01
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 the order of 10-50kJ. Some experimental results will be presented in this paper.
Decoupled 1D/3D analysis of a hydraulic valve
Mehring, Carsten; Zopeya, Ashok; Latham, Matt; Ihde, Thomas; Massie, Dan
2014-10-01
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.
The GIRAFFE Archive: 1D and 3D Spectra
Royer, F.; Jégouzo, I.; Tajahmady, F.; Normand, J.; Chilingarian, I.
2013-10-01
The GIRAFFE Archive (giraffe-archive.obspm.fr'>http://giraffe-archive.obspm.fr) contains the reduced spectra observed with the intermediate and high resolution multi-fiber spectrograph installed at VLT/UT2 (ESO). In its multi-object configuration and the different integral field unit configurations, GIRAFFE produces 1D spectra and 3D spectra. We present here the status of the archive and the different functionalities to select and download both 1D and 3D data products, as well as the present content. The two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations. These latter products can be explored using the VO Paris Euro3D Client (http://voplus.obspm.fr/ chil/Euro3D).
GIS-BASED 1-D DIFFUSIVE WAVE OVERLAND FLOW MODEL
Energy Technology Data Exchange (ETDEWEB)
KALYANAPU, ALFRED [Los Alamos National Laboratory; MCPHERSON, TIMOTHY N. [Los Alamos National Laboratory; BURIAN, STEVEN J. [NON LANL
2007-01-17
This paper presents a GIS-based 1-d distributed overland flow model and summarizes an application to simulate a flood event. The model estimates infiltration using the Green-Ampt approach and routes excess rainfall using the 1-d diffusive wave approximation. The model was designed to use readily available topographic, soils, and land use/land cover data and rainfall predictions from a meteorological model. An assessment of model performance was performed for a small catchment and a large watershed, both in urban environments. Simulated runoff hydrographs were compared to observations for a selected set of validation events. Results confirmed the model provides reasonable predictions in a short period of time.
Dissociative recombination source for O I /1D/ atoms
Sharp, W. E.; Rusch, D. W.; Hays, P. B.
1975-01-01
A study of the nighttime dissociative recombination production of O(1D) is reported. The data were gathered by a rocket payload carrying an ion mass spectrometer, Langmuir probe, retarding potential analyzer, and 6300-A photometer. The specific recombination rate to produce O(1D) atoms is deduced to be (2.8 + or - 1.0) times 10 to the minus 8th cu cm per sec and is 30% of the total laboratory rate. The quenching rate at 250 km is 0.0044 + or - 0.0015 per sec.
Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Bocvarski, V.; Ducloy, M.
2007-04-01
1D and 2D reflection gratings (Permalloy stripes or dots deposited on silicon), immersed in an external homogeneous static magnetic field, are used to study 1D and 2D diffraction of fast metastable helium atoms He* (23S1). Both the grazing incidence used here and the repulsive potential (for sub-level m = -1) generated by the magnetisation reduce the quenching effect. This periodically structured potential is responsible for the diffraction in the incidence plane as well as for the diffraction in the perpendicular plane.
WOLF 1D PKW - Modèle numériqeu 1D des écoulements sur un déversoir en touches de piano
Erpicum, Se?bastien; Archambeau, Pierre; Dewals, Benjamin; Machiels, Olivier; Pirotton, Michel
2011-01-01
The Piano Key Weir (PKW) is a new type of free weir, similar to a labyrinth weir, showing appealing performance to release high discharges under limited head levels in the upstream reservoir. Because of the PKW geometric specificities, its hydraulic capacity remains difficult to predict without using experimental techniques. Wolf1D PKW numerical model has been developed at the Research Unit HACH at the University of Liege to model the flow over a PKW. It is based on a 1D modelling of the PKW ...
Polaron in a quasi 1D cylindrical quantum wire
Directory of Open Access Journals (Sweden)
I.Nsangou
2005-01-01
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.
Surface EM waves on 1D Photonic Crystals
Morozov, G V; Martorell, J
2006-01-01
We study surface states of 1D photonic crystals using a semiclassical coupled wave theory. Both TE and TM modes are treated. We derive analytic approximations that clarify the systematics of the dispersion relations, and the roles of the various parameters defining the crystal.
Surface EM waves in 1D Photonic Crystals
Martorell, J; Sprung, D W L
2005-01-01
Accurate analytic approximations are developed for the band gap boundaries and surface waves of a 1D photonic crystal, making use of the semiclassical theory recently developed by the authors: [Phys. Rev. E {69} (2004) 016612 and {70} (2004) 016606]. These analytic results provide useful insight on systematics of surface states.
Lifescience Database Archive (English)
Full Text Available 1D8U ?? Rice Oryza sativa L. Non-Symbiotic Hemoglobin ... 1 Name=Hb1; Synonyms=Glb1a; Oryza Sativa ... Molecule: Non-Symbiotic Hemoglobin ; Chain: A, B; Engineered: Yes Oxygen Storage/Trans ... lips Jr. Crystal Structure Of A Nonsymbiotic Plant Hemoglobin ... Structure V. 8 1005 2000 Globin, Bis-Histidyl, Hem ...
Large Time existence For 1D Green-Naghdi equations
Israwi, Samer
2009-01-01
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.
5?-Reduced steroids and human ?(4)-3-ketosteroid 5?-reductase (AKR1D1).
Chen, Mo; Penning, Trevor M
2014-05-01
5?-Reduced steroids are non-planar steroids that have a 90° bend in their structure to create an A/B cis-ring junction. This novel property is required for bile-acids to act as emulsifiers, but in addition 5?-reduced steroids have remarkable physiology and may act as potent tocolytic agents, endogenous cardiac glycosides, neurosteroids, and can act as ligands for orphan and membrane bound receptors. In humans there is only a single 5?-reductase gene AKR1D1, which encodes ?(4)-3-ketosteroid-5?-reductase (AKR1D1). This enzyme is a member of the aldo-keto reductase superfamily, but possesses an altered catalytic tetrad, in which Glu120 replaces the conserved His residue. This predominant liver enzyme generates all 5?-dihydrosteroids in the C19-C27 steroid series. Mutations exist in the AKR1D1 gene, which result in loss of protein stability and are causative in bile-acid deficiency. PMID:24513054
Intra prediction with 1D macroblock partitioning for image and video coding
Laroche, G.; Jung, J.; Pesquet, B.
2009-01-01
The H.264/AVC1 standard of the Video Coding Experts Group (VCEG) and the Moving Pictures Experts Group (MPEG), also known as MPEG-4 AVC, achieves significant compression gain compared to its predecessors. Not only Inter yet also Intra coding has been greatly improved. Today VCEG encourages coding efficiency improvements through the KTA (Key Technical Area) software,2 a collection of tools that improves the H.264/AVC standard, to prepare the next generation video codec. The work proposed in this paper has been designed in this context. An Intra coding scheme is proposed. A macroblock is split in 1D partitions to reduce the distance between the pixel to encode and its predictors. Three scan orders for the partitions are available: a raster scan, a bidirectional scan and a hierarchical scan. Predictors adapted to the shape and characteristics of the 1D partitions are defined and finally a 1D-DCT is applied to the residual signal. Experimental results report an average bitrate savings of 8.6% compared to the H.264/AVC standard (up to 19% on a particular sequence).
1D design style implications for mask making and CEBL
Smayling, Michael C.
2013-09-01
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.
Directory of Open Access Journals (Sweden)
Hadley Robert W
2008-02-01
Full Text Available Abstract Background The cellular localization of the ?1D-adrenergic receptor (?1D-AR is controversial. Studies in heterologous cell systems have shown that this receptor is expressed in intracellular compartments. Other studies show that dimerization with other ARs promotes the cell surface expression of the ?1D-AR. To assess the cellular localization in vascular smooth muscle cells, we developed an adenoviral vector for the efficient expression of a GFP labeled ?1D-AR. We also measured cellular localization with immunocytochemistry. Intracellular calcium levels, measurement of reactive oxygen species and contraction of the rat aorta were used as measures of functional activity. Results The adenovirally expressed ?1D-AR was expressed in intracellular compartments in human aortic smooth muscle cells. The intracellular localization of the ?1D-AR was also demonstrated with immunocytochemistry using an ?1D-AR specific antibody. RT-PCR analysis detected mRNA transcripts corresponding to the ?1A-?1B- and ?1D-ARs in these aortic smooth muscle cells. Therefore, the presence of the other ?1-ARs, and the potential for dimerization with these receptors, does not alter the intracellular expression of the ?1D-AR. Despite the predominant intracellular localization in vascular smooth muscle cells, the ?1D-AR remained signaling competent and mediated the phenylephrine-induced increases in intracellular calcium. The ?1D-AR also was coupled to the generation of reactive oxygen species in smooth muscle cells. There is evidence from heterologous systems that the ?1D-AR heterodimerizes with the ?2-AR and that desensitization of the ?2-AR results in ?1D-AR desensitization. In the rat aorta, desensitization of the ?2-AR had no effect on contractile responses mediated by the ?1D-AR. Conclusion Our results suggest that the dimerization of the ?1D-AR with other ARs does not alter the cellular expression or functional response characteristics of the ?1D-AR.
García-Cazarín, Mary L; Smith, Jennifer L; Olszewski, Kyle A; McCune, Dan F; Simmerman, Linda A; Hadley, Robert W; Kraner, Susan D; Piascik, Michael T
2008-01-01
Background The cellular localization of the ?1D-adrenergic receptor (?1D-AR) is controversial. Studies in heterologous cell systems have shown that this receptor is expressed in intracellular compartments. Other studies show that dimerization with other ARs promotes the cell surface expression of the ?1D-AR. To assess the cellular localization in vascular smooth muscle cells, we developed an adenoviral vector for the efficient expression of a GFP labeled ?1D-AR. We also measured cellular localization with immunocytochemistry. Intracellular calcium levels, measurement of reactive oxygen species and contraction of the rat aorta were used as measures of functional activity. Results The adenovirally expressed ?1D-AR was expressed in intracellular compartments in human aortic smooth muscle cells. The intracellular localization of the ?1D-AR was also demonstrated with immunocytochemistry using an ?1D-AR specific antibody. RT-PCR analysis detected mRNA transcripts corresponding to the ?1A-?1B- and ?1D-ARs in these aortic smooth muscle cells. Therefore, the presence of the other ?1-ARs, and the potential for dimerization with these receptors, does not alter the intracellular expression of the ?1D-AR. Despite the predominant intracellular localization in vascular smooth muscle cells, the ?1D-AR remained signaling competent and mediated the phenylephrine-induced increases in intracellular calcium. The ?1D-AR also was coupled to the generation of reactive oxygen species in smooth muscle cells. There is evidence from heterologous systems that the ?1D-AR heterodimerizes with the ?2-AR and that desensitization of the ?2-AR results in ?1D-AR desensitization. In the rat aorta, desensitization of the ?2-AR had no effect on contractile responses mediated by the ?1D-AR. Conclusion Our results suggest that the dimerization of the ?1D-AR with other ARs does not alter the cellular expression or functional response characteristics of the ?1D-AR. PMID:18304336
Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses
Rathod, K D; Natarajan, Vasant
2013-01-01
We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.
Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses
Rathod, K. D.; Singh, P. K.; Natarajan, Vasant
2014-09-01
We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.
Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses
Rathod, K. D.; Singh, Pushpander; Natarajan, Vasant
2013-01-01
We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{1...
Choi, Seung Ho; Byun, Kyung Min; Kim, Young L
2015-03-01
Excitation of hybridized multiple resonances can be an effective route for coherent light generation in irregular 1D systems larger than the localization length of light. Necklace states are often considered to have nonlocalized states. However, we propose that some hybridized/coupled states can have high-resonant tunneling with spatially extended fields. If strong localization properties are preserved in hybridized resonances, the excitation of such states allows for deposition of the excitation energy deep into the structure and spatial overlap with local gain regions. This result could allow for better utilizing hybridized resonances in biological or natural photonic systems. PMID:25723448
Near-field localization of ultrashort optical pulses in transverse 1-D periodic nanostructures.
Nakagawa, W; Tyan, R C; Sun, P C; Fainman, Y
2000-07-31
We present a transverse 1-D periodic nanostructure which exhibits lateral internal Thorneld localization for normally incident ultrashort pulses, and which may be applied to the enhancement of nonlinear optical phenomena. The peak intensity of an optical pulse propagating in the nanostructure is approximately 12 times that of an identical incident pulse propagating in a bulk material of the same refractive index. For second harmonic generation, an overall enhancement factor of approximately 10.8 is predicted. Modeling of pulse propagation is performed using Fourier spectrum decomposition and Rigorous Coupled-Wave Analysis (RCWA). PMID:19404377
Plasmonic Excitations of 1D Metal-Dielectric Interfaces in 2D Systems: 1D Surface Plasmon Polaritons
Mason, Daniel R.; Menabde, Sergey G.; Yu, Sunkyu; Park, Namkyoo
2014-04-01
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.
Lidia B?aszczyk; Barbara Apolinarska; Micha? Kwiatek; Halina Wi?niewska; Monika Langner; Salmanowicz, Boles?aw P.
2013-01-01
Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or...
Iron-based 1D nanostructures by electrospinning process
Energy Technology Data Exchange (ETDEWEB)
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
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.
Iron-based 1D nanostructures by electrospinning process
International Nuclear Information System (INIS)
Iron-based 1D nanostructures have been successfully prepared using an electrospinning technique and varying the pyrolysis atmospheres. Hematite (Fe2O3) nanotubes and polycrystalline Fe3C nanofibers were obtained by simple air or mixed gas (H2, Ar) annealing treatments. Using the air annealing treatment, a high control of the morphology as well as of the wall thickness of the nanotubes was demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H2 and Ar) were used for the annealing treatments, for the first time polycrystalline Fe3C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe3C nanoparticle stability and nanofiber cohesion. The morphology and structural properties of all these iron-based 1D nanostructures were fully characterized by SEM, TEM, XRD and Raman spectroscopy.
Developing 1D nanostructure arrays for future nanophotonics
Directory of Open Access Journals (Sweden)
Cooke DG
2006-01-01
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.
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
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
Positive Magneto-Resistance in Quasi-1D Conductors
Martin, I; Martin, Ivar; Phillips, Philip
1997-01-01
We present here a simple qualitative model that interpolates between the high and low temperature properties of quasi-1D conductors. At high temperatures we argue that transport is governed by inelastic scattering whereas at low temperatures the conductance decays exponentially with the electron dephasing length. The crossover between these regimes occurs at the temperature at which the elastic and inelastic scattering times become equal. This model is shown to be in quantitative agreement with the organic conductor $TTT_2I_{3-\\delta}$. Within this model, we also show that on the insulating side, the positive magnetoresistance of the form $(H/T)^2$ observed in $TTT_2I_{3-\\delta}$ and other quasi-1D conductors can be explained by the role spin-flip scattering plays in the electron dephasing rate.
D1-D5-P microstates at the cap
Giusto, Stefano; Mathur, Samir D; Turton, David
2012-01-01
The geometries describing D1-D5-P bound states in string theory have three regions: flat asymptotics, an anti-de Sitter throat, and a 'cap' region at the bottom of the throat. We identify the CFT description of a known class of supersymmetric D1-D5-P microstate geometries which describe degrees of freedom in the cap region. The class includes both regular solutions and solutions with conical defects, and generalizes configurations with known CFT descriptions: a parameter related to spectral flow in the CFT is generalized from integer to fractional values. We provide strong evidence for this identification by comparing the massless scalar excitation spectrum between gravity and CFT and finding exact agreement.
1D Cahn-Hilliard equation for modulated phase systems
Energy Technology Data Exchange (ETDEWEB)
Villain-Guillot, Simon, E-mail: simon.villain-guillot@u-bordeaux1.f [Centre de Physique Moleculaire Optique et Hertzienne, Universite Bordeaux I, 351 cours de la Liberation 33405 Talence Cedex (France)
2010-05-21
Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.
OrthoZoom Scroller: 1D Multi-Scale Navigation
Appert, Caroline; Fekete, Jean-daniel
2006-01-01
This article introduces the OrthoZoom Scroller, a novel interaction technique that improves target acquisition in very large one-dimensional spaces. The OrthoZoom Scroller requires only a mouse to perform panning and zooming in a 1D space. Panning is performed along the slider dimension while zooming is performed along the orthogonal one. We present a controlled experiment showing that the OrthoZoom Scroller is about twice as fast as Speed Dependant Automatic Zooming to perform pointing tasks...
Dimer impurity effect on the 1D density of states
International Nuclear Information System (INIS)
We study the effect of a dimer impurity on the local density of states (LDOS) associated with 1D tight binding Hamiltonian. Theoretical analysis is carried out by studying the resulting three-term recursion relation corresponding to the tridiagonal representation of the system Hamiltonian. We found a closed form expression for the perturbed LDOS in terms of the unperturbed one with a pre-factor that carries information on both location and potential strength of the dimer impurity.
Nonreciprocity of edge modes in 1D magnonic crystal
Lisenkov, I.; Kalyabin, D.; Osokin, S.; Klos, J. W.; Krawczyk, M.; Nikitov, S.
2015-03-01
Spin waves propagation in 1D magnonic crystals is investigated theoretically. Mathematical model based on plane wave expansion method is applied to different types of magnonic crystals, namely bi-component magnonic crystal with symmetric/asymmetric boundaries and ferromagnetic film with periodically corrugated top surface. It is shown that edge modes in magnonic crystals may exhibit nonreciprocal behaviour at much lower frequencies than in homogeneous films.
Feedback stabilization of a simplified 1d fluid- particle system
Badra, Mehdi; Takahashi, Take?o
2013-01-01
We consider the feedback stabilization of a simplified 1d model for a fluid-structure interaction system. The fluid equation is the viscous Burgers equation whereas the motion of the particle is given by the Newton's laws. We stabilize this system around a stationary state by using feedbacks located at the exterior boundary of the fluid domain. With one input, we obtain a local stabilizability of the system with an exponential decay rate of order $\\sigma
Dynamical Delocalization for the 1D Bernoulli Discrete Dirac Operator
Oliveira, Cesar R.; Prado, Roberto A.
2005-01-01
An 1D tight-binding version of the Dirac equation is considered; after checking that it recovers the usual discrete Schr?odinger equation in the nonrelativistic limit, it is found that for two-valued Bernoulli potentials the zero mass case presents absence of dynamical localization for specific values of the energy, albeit it has no continuous spectrum. For the other energy values (again excluding some very specific ones) the Bernoulli Dirac system is localized, independentl...
1D Cahn-Hilliard equation for modulated phase systems
Villain-guillot, Simon
2009-01-01
Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non local term preventing the formation of macroscopic domains. Using stationnary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long range interaction
1D Cahn-Hilliard equation for modulated phase systems
International Nuclear Information System (INIS)
Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.
1D Effectively Closed Subshifts and 2D Tilings
Bruno, Durand; Romashchenko, Andrei
2010-01-01
Michael Hochman showed that every 1D effectively closed subshift can be simulated by a 3D subshift of finite type and asked whether the same can be done in 2D. It turned out that the answer is positive and necessary tools were already developed in tilings theory. We discuss two alternative approaches: first, developed by N. Aubrun and M. Sablik, goes back to Leonid Levin; the second one, developed by the authors, goes back to Peter Gacs.
The Cosmological Mass Function with 1D Gravity
Monaco, Pierluigi; Murante, Giuseppe
1999-01-01
The cosmological mass function problem is analyzed in full detail in the case of 1D gravity, with analytical, semi-analytical and numerical techniques. The extended Press & Schechter theory is improved by detailing the relation between smoothing radius and mass of the objects. This is done by introducing in the formalism the concept of a growth curve for the objects. The predictions of the extended Press & Schechter theory are compared to large N-body simulations of flat exp...
Partial breaking of N=1, D=10 supersymmetry
Bellucci, S.; Ivanov, E.; Krivonos, S.
1998-01-01
We describe the spontaneous partial breaking of $N=1 D=10$ supersymmetry to $N=(1,0) d=6$ and its dimensionally-reduced versions in the framework of the nonlinear realizations method. The basic Goldstone superfield is $N=(1,0) d=6$ hypermultiplet superfield satisfying a nonlinear generalization of the standard hypermultiplet constraint. We interpret the generalized constraint as the manifestly worldvolume supersymmetric form of equations of motion of the Type I super 5-brane...
Group Manifold Reduction of Dual N=1 d=10 Supergravity
Roo, Mees; Eenink, Martijn G. C.; Panda, Sudhakar; Westra, Dennis B.
2005-01-01
We perform a group manifold reduction of the dual version of N=1 d=10 supergravity to four dimensions. The effects of the 3- and 4-form gauge fields in the resulting gauged N=4 d=4 supergravity are studied in particular. The example of the group manifold SU(2)xSU(2) is worked out in detail, and we compare for this case the four-dimensional scalar potential with gauged N=4 supergravity.
Enhancing Solar Cell Efficiencies through 1-D Nanostructures
Directory of Open Access Journals (Sweden)
Yu Kehan
2008-01-01
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.
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)
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)
Enhancing Solar Cell Efficiencies through 1-D Nanostructures
2009-01-01
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.
Coupling of Nod1D and HOTCHANNEL: static case; Acoplamiento de Nod1D y HOTCHANNEL: caso estatico
Energy Technology Data Exchange (ETDEWEB)
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
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)
Extended-Range Ultrarefractive 1D Photonic Crystal Prisms
Ting, David Z.
2007-01-01
A proposal has been made to exploit the special wavelength-dispersive characteristics of devices of the type described in One-Dimensional Photonic Crystal Superprisms (NPO-30232) NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 10a. A photonic crystal is an optical component that has a periodic structure comprising two dielectric materials with high dielectric contrast (e.g., a semiconductor and air), with geometrical feature sizes comparable to or smaller than light wavelengths of interest. Experimental superprisms have been realized as photonic crystals having three-dimensional (3D) structures comprising regions of amorphous Si alternating with regions of SiO2, fabricated in a complex process that included sputtering. A photonic crystal of the type to be exploited according to the present proposal is said to be one-dimensional (1D) because its contrasting dielectric materials would be stacked in parallel planar layers; in other words, there would be spatial periodicity in one dimension only. The processes of designing and fabricating 1D photonic crystal superprisms would be simpler and, hence, would cost less than do those for 3D photonic crystal superprisms. As in 3D structures, 1D photonic crystals may be used in applications such as wavelength-division multiplexing. In the extended-range configuration, it is also suitable for spectrometry applications. As an engineered structure or artificially engineered material, a photonic crystal can exhibit optical properties not commonly found in natural substances. Prior research had revealed several classes of photonic crystal structures for which the propagation of electromagnetic radiation is forbidden in certain frequency ranges, denoted photonic bandgaps. It had also been found that in narrow frequency bands just outside the photonic bandgaps, the angular wavelength dispersion of electromagnetic waves propagating in photonic crystal superprisms is much stronger than is the angular wavelength dispersion obtained by use of conventional prisms and diffraction gratings and is highly nonlinear.
1-D modeling of ion transport in rectangular nanofluidic channels
Kun, Liu; Dechun, Ba; Xiaoguang, Gu; Guangyu, Du; Zeng, Lin; Xinghua, Liu; Zhixue, Wang; Songwen, Xiao
2012-01-01
Based on the continuity hypothesis of fluid, 1-D mathematical models of ions' transport in the rectangular nanofluidic channels are established by using the Poisson-Boltzmann (PB) equation and the modified Navier-Stokes (N-S) equations. The deduced equations are solved with MATLAB software. The results show that the distribution of the electric potential and the flow field could be predicted by the parameters, such as conductivity, surface charge density, solution concentration and channel height. The relationships between the parameters and the flow characteristics of the solution are also discussed. The research will help to the accurate manipulation of the solution in the nanofluidic channels.
Analytical approach to 1D bound state problems
Šindelka, M.; Eleuch, H.; Rostovtsev, Y. V.
2012-08-01
Using a recently developed new analytic approach to solution of the 1D Schrödinger equation [Eleuch et al., Europhys. Lett. 89, 50004 (2010)], we derive a quantization rule determining the positions of bound state energy levels in an arbitrary potential. The obtained quantization formula is applied to a simple model problem and is found to be superior to the well known Bohr-Sommerfeld (JWKB) quantization rule. Contrary to the JWKB prescription, our new formula contains extra contributions arising from the classically forbidden regions. The corresponding analytic wavefunctions are smooth even at the classical turning points.
Magnetic polarons in doped 1D antiferromagnetic chain
Gonza?lez, I.; Castro, J.; Baldomir, D.; Sboychakov, A. O.; Rakhmanov, A. L.; Kugel, K. I.
2003-01-01
The structure of magnetic polarons (ferrons) is studied for an 1D antiferromagnetic chain doped by non-magnetic donor impurities. The conduction electrons are assumed to be bound by the impurities. Such a chain can be described as a set of ferrons at the antiferromagnetic background. We found that two types of ferrons can exist in the system. The ground state of the chain corresponds to the ferrons with the sizes of the order of the localization length of the electron near t...
Phthalocyanine based 1D nanowires for device applications
Saini, Rajan; Mahajan, Aman; Bedi, R. K.
2012-06-01
1D nanowires (NWs) of Cu (II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-Phthalocyanine (CuPc(OBu)8) molecule have been grown on different substrates by cost effective solution processing technique. The density of NWs is found to be strongly dependent on the concentration of solution. The possible formation mechanism of these structures is ?-? interaction between phthalocyanine molecules. The improved conductivity of these NWs as compared to spin coated film indicates their potential for molecular device applications.
Deconvolution/identification techniques for 1-D transient signals
Energy Technology Data Exchange (ETDEWEB)
Goodman, D.M.
1990-10-01
This paper discusses a variety of nonparametric deconvolution and identification techniques that we have developed for application to 1-D transient signal problems. These methods are time-domain techniques that use direct methods for matrix inversion. Therefore, they are not appropriate for large data'' problems. These techniques involve various regularization methods and permit the use of certain kinds of a priori information in estimating the unknown. These techniques have been implemented in a package using standard FORTRAN that should make the package readily transportable to most computers. This paper is also meant to be an instruction manual for the package. 25 refs., 17 figs., 1 tab.
1D models for condensation induced water hammer in pipelines
Energy Technology Data Exchange (ETDEWEB)
Bloemeling, Frank; Neuhas, Thorsten; Schaffrath, Andreas [TUEV NORD SysTec GmbH und Co. KG, Hamburg (Germany)
2013-03-15
Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)
Effective transport equations in quasi 1D systems
Kalinay, P.
2014-12-01
The mapping methods reducing 2D or 3D transport equations in quasi 1D structures onto the longitudinal coordinate x are revisited. The general formalism based on homogenization is explained on the simplest case, diffusion in a 2D channel of varying width A(x). Then its modifications to diffusion in an external field (Smoluchowski equation), and nonzero mass of the particles (Klein-Kramers equation) are demonstrated. A special attention is payed to the role of the "natural" curvilinear coordinates, connected with the stationary flow, in the mapping and derivation of the effective equations.
A 1D analysis of two high order MOC methods
International Nuclear Information System (INIS)
The work presented here provides two different methods for evaluating angular fluxes along long characteristics. One is based off a projection of the 1D transport equation onto a complete set of Legendre polynomials, while the other uses the 1D integral transport equation to evaluate the angular flux values at specific points along each track passing through a cell. The Moment Long Characteristic (M-LC) method is shown to provide 2(P+1) spatial convergence and significant gains in accuracy with the addition of only a few spatial degrees of freedom. The M-LC method, though, is shown to be ill-conditioned at very high order and for optically thin geometries. The Point Long Characteristic (P-LC) method, while less accurate, significantly improves stability to problems with optically thin cells. The P-LC method is also more flexible, allowing for extra angular flux evaluations along a given track to give a more accurate representation of the shape along each track. This is at the expense of increasing the degrees of freedom of the system, though, and requires an increase in memory storage. This work concludes that both may be used simultaneously within the same geometry to provide the best mix of accuracy and stability possible. (authors)
1-D DCT Using Latency Efficient Floating Point Algorithms
Directory of Open Access Journals (Sweden)
Viswanath Gowd A, Yedukondala Rao V, T. Shanmuganantham
2013-04-01
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.
Numerical shock instability on 1D Euler equations
Wahi, Nadihah; Ismail, Farzad
2013-04-01
Numerical shock instabilities are deficiencies that may occur when predicting a shockwave in compressible flow computations. These deficiencies are usually present in shock capturing schemes with minimal numerical diffusion (i.e. Roe flux) when computing slowly moving shock problems, the hypersonic wall heating problem (Noh's problem) and even when simply predicting a steady state supersonic flow past a circular cylinder. For the supersonic flow past a cylinder, the predicted solution would normally consist of a pair of oblique shocks as opposed to the correct solution which is a bow-shock. Thus, the predicted thermodynamic quantities behind the shockwave are incorrect, compromising the overall flow predictions around the cylinder. This problem is also infamously known as the carbuncle phenomenon. The carbuncle problem has been around for more than 20 years yet there is no consensus within the literature of its true 'cause'. Recent studies have pointed out that the carbuncle may manifest itself in 2D, 1 1/2 D and even 1D shock structures. The current study will investigate the stability of 1D shock profiles based on the scalar and isothermal Euler equations using a numerical method based on Roe-flux. The results of this study will hopefully pave the way to better understand the root of the carbuncle phenomenon.
Hemi-omnidirectional lasing from a cholesteric liquid crystal layer on a 1D photonic crystal film
Energy Technology Data Exchange (ETDEWEB)
Park, Byoungchoo [Kwangwoon University, Seoul (Korea, Republic of)
2011-09-15
We herein report on a hybrid photonic band gap (PBG) system, which was fabricated using a cholesteric liquid crystal (CLC) layer on a 1-dimensional (1D) photonic crystal (PC) film, i.e., hybrid 'CLC/1D PC'. The CLC layer is made of nematic liquid crystal monomers embedded in polymeric helical CLC networks, thereby exhibiting a field-induced reorientational undulation of the helical axis. It is shown that intensity-controllable circularly polarized laser emissions may be generated at the wavelength of the high-energy band edge mode of the CLC layer in the dye-doped 'CLC/1D PC' PBG structure. The handedness of the lasing light corresponds to the handedness of the CLC layer used. Moreover, the direction of propagation of laser emissions could be manipulated from uni- to hemi-omnidirectional for the hybrid 'CLC/1D PC' PBG structure by applying an electric field.
Crossed molecular beams study of O({sup 1}D) reactions with H{sub 2} molecules
Energy Technology Data Exchange (ETDEWEB)
Miau, T.T.
1995-05-01
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.
Mukherjee, Bratindranath; Gupta, Satyajit; Peterson, Aaron; Imahori, Hiroshi; Manivannan, Ayyakkannu; Subramanian, Vaidyanathan Ravi
2014-08-11
A unique heterostructured optoelectronic material (HOM), consisting of a reduced graphene oxide (RGO) layer with spatially distributed CdS, suspended by zinc oxide (ZnO) nanorods, is presented. The key features of this HOM are the assembly of the components in a manner so as to realize an effective integration between the constituents and the ability to modify the electronic properties of the RGO. For the first time, the location of RGO (as a suspended layer) along with the tuning of its charge-transport properties (n-/p-type) and its influence on the photo(electro)chemical processes has been examined systematically by using this ZnO/RGO/CdS HOM as a case study. The n-type RGO interlayer facilitates >100?% increase in the photocurrent density and 25?% increase in the photodegradation of a dye, compared to ZnO/CdS, thus demonstrating its multifunctionality. At 3.2?mA?cm(-2) , this HOM architecture helps to achieve the highest photocurrent density utilizing ZnO, RGO, and CdS as building blocks in any form. The work is significant for the following reasons: i)?other one dimensional (1D) oxides/chalcogenides or 1D oxides/dyes may be designed with similar architectures; ii)?HOMs with tunable optical absorbance and charge-transport properties could be realized; iii)?related application areas (e.g., sensing or solar fuel generation) should be greatly benefited. PMID:25066752
DISCOLORATION OF THE WETTED SURFACE IN THE 6.1D DISSOLVER
Energy Technology Data Exchange (ETDEWEB)
Rudisill, T.; Mickalonis, J.; Crapse, K.
2013-12-18
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.
DEFF Research Database (Denmark)
Treebak, Jonas Thue; PehmØller, Christian
2014-01-01
We investigated the phosphorylation signatures of two Rab GTPase activating proteins TBC1D1 and TBC1D4 in human skeletal muscle in response to physical exercise and physiological insulin levels induced by a carbohydrate rich meal using a paired experimental design. Eight healthy male volunteers exercised in the fasted or fed state and muscle biopsies were taken before and immediately after exercise. We identified TBC1D1/4 sites that did not respond to either exercise or insulin (TBC1D4: S666), that responded to insulin only (TBC1D4: S318), that responded to exercise only (TBC1D1: S237, S660, S700; TBC1D4: S588, S751), and that responded to both insulin and exercise (TBC1D1: T596; TBC1D4: S341, T642, S704). In the insulin stimulated leg, Akt phosphorylation on both T308 and S473 correlated significantly with multiple sites on both TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Interestingly, in the exercised leg in the fasted state TBC1D1 phosphorylation (S237, T596) correlated significantly with the activity ofthe ?2?2?3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) correlated with the activity of the ?2?2?1 AMPK trimer. Our data show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK was regulating phosphorylation of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between species are difficult.
Ishii, Hiroshi; Asai, Yasuhiro
2015-12-01
Although precursory signs of an earthquake can occur before the event, it is difficult to observe such signs with precision, especially on earth's surface where artificial noise and other factors complicate signal detection. One possible solution to this problem is to install monitoring instruments into the deep bedrock where earthquakes are likely to begin. When evaluating earthquake occurrence, it is necessary to elucidate the processes of stress accumulation in a medium and then release as a fault (crack) is generated, and to do so, the stress must be observed continuously. However, continuous observations of stress have not been implemented yet for earthquake monitoring programs. Strain is a secondary physical quantity whose variation varies depending on the elastic coefficient of the medium, and it can yield potentially valuable information as well. This article describes the development of a borehole stress meter that is capable of recording both continuous stress and strain at a depth of about 1 km. Specifically, this paper introduces the design principles of the stress meter as well as its actual structure. It also describes a newly developed calibration procedure and the results obtained to date for stress and strain studies of deep boreholes at three locations in Japan. To show examples of the observations, records of stress seismic waveforms generated by the 2011 Tohoku earthquake ( M 9.0) are presented. The results demonstrate that the stress meter data have sufficient precision and reliability.
Topological expansion and exponential asymptotics in 1D quantum mechanics
International Nuclear Information System (INIS)
Borel summable semiclassical expansions in 1D quantum mechanics are considered. These are the Borel summable expansions of fundamental solutions and of quantities constructed with their help. An expansion, called topological, is constructed for the corresponding Borel functions. This allows us to study the Borel plane singularity structure in a systematic way. Examples of such structures are considered for linear, harmonic and anharmonic potentials. Together with the best approximation provided by the semiclassical series the exponentially small contributions completing the approximation are considered. A natural method of constructing such exponential asymptotics based on the Borel plane singularity structures provided by the topological expansion is developed. The method is used to form the semiclassical series including exponential contributions for the energy levels of the anharmonic oscillator. (author)
Topological Expansion and Exponential Asymptotics in 1D Quantum Mechanics
Giller, S
2000-01-01
Borel summable semiclassical expansions in 1D quantum mechanics are considered. These are the Borel summable expansions of fundamental solutions and of quantities constructed with their help. An expansion, called topological,is constructed for the corresponding Borel functions. Its main property is to order the singularity structure of the Borel plane in a hierarchical way by an increasing complexity of this structure starting from the analytic one. This allows us to study the Borel plane singularity structure in a systematic way. Examples of such structures are considered for linear, harmonic and anharmonic potentials. Together with the best approximation provided by the semiclassical series the exponentially small contribution completing the approximation are considered. A natural method of constructing such an exponential asymptotics relied on the Borel plane singularity structures provided by the topological expansion is developed. The method is used to form the semiclassical series including exponential ...
Directed enzymatic activation of 1-d DNA tiles.
Garg, Sudhanshu; Chandran, Harish; Gopalkrishnan, Nikhil; LaBean, Thomas H; Reif, John
2015-02-24
The tile assembly model is a Turing universal model of self-assembly where a set of square shaped tiles with programmable sticky sides undergo coordinated self-assembly to form arbitrary shapes, thereby computing arbitrary functions. Activatable tiles are a theoretical extension to the Tile assembly model that enhances its robustness by protecting the sticky sides of tiles until a tile is partially incorporated into a growing assembly. In this article, we experimentally demonstrate a simplified version of the Activatable tile assembly model. In particular, we demonstrate the simultaneous assembly of protected DNA tiles where a set of inert tiles are activated via a DNA polymerase to undergo linear assembly. We then demonstrate stepwise activated assembly where a set of inert tiles are activated sequentially one after another as a result of attachment to a growing 1-D assembly. We hope that these results will pave the way for more sophisticated demonstrations of activated assemblies. PMID:25625898
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.)
1D-transport properties of single superconducting lead nanowires
DEFF Research Database (Denmark)
Michotte, S.; Mátéfi-Tempfli, Stefan
2003-01-01
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.
Towards a consistent picture for quasi-1D organic superconductors
International Nuclear Information System (INIS)
The electrical resistivity of the quasi-1D organic superconductor (TMTSF)2PF6 was recently measured at low temperature from the critical pressure needed to suppress the spin-density-wave state up to a pressure where superconductivity has almost disappeared. This data revealed a direct correlation between the onset of superconductivity at Tc and the strength of a non-Fermi-liquid linear term in the normal-state resistivity, going as ?(T)=?0+AT+BT2 at low temperature, so that A?0 as Tc?0. Here we show that the contribution of low-frequency antiferromagnetic fluctuations to the spin-lattice relaxation rate is also correlated with this non-Fermi-liquid term AT in the resistivity. These correlations suggest that anomalous scattering and pairing have a common origin, both rooted in the low-frequency antiferromagnetic fluctuations measured by NMR. A similar situation may also prevail in the recently discovered iron-pnictide superconductors.
1D simulation of sawtooth crash based on transport bifurcation
International Nuclear Information System (INIS)
The crash of the temperature profile associated with a propagating transport bifurcation between the L-mode and the magnetic braiding mode (M-mode) in a tokamak plasma is presented. The magnetic braiding mode is induced by the magnetic stochasticity. If the pressure gradient exceeds a threshold value a magnetic stochasticity sets in and the heat conductivity is much enhanced (M-mode). The back transition to the L-mode occurs when the pressure gradient decreases to another threshold value. The model of the transport bifurcation is included in the 1D transport code. The crash of the temperature profile and the propagation of the crash front (avalanche) are realized by this model. The collapse without a precursor oscillation is revealed. (author)
Interaction quenches in the 1D Bose gas
Kormos, Marton; Chou, Yang-Zhi; Caux, Jean-Sebastien; Imambekov, Adilet
2013-01-01
The non-equilibrium dynamics of integrable systems are special: there is substantial evidence that after a quantum quench they do not thermalize but their asymptotic steady state can be described by a Generalized Gibbs Ensemble (GGE). Most of the studies on the GGE so far have focused on models that can be mapped to quadratic systems while analytic treatment in non-quadratic systems remained elusive. We obtain results on interaction quenches in a non-quadratic continuum system, the 1D Bose gas described by the integrable Lieb-Liniger model. We compute local correlators for a non-interacting initial state and arbitrary final interactions as well as two-point functions for quenches to the Tonks-Girardeau regime. We show that in the long time limit integrability leads to significant deviations from the predictions of the grand canonical ensemble.
Stochastic quantum dynamics in 1D and lattice systems
Ruostekoski, J
2010-01-01
We show that stochastic phase-space methods within the truncated Wigner approximation can be used to solve non-equilibrium dynamics of bosonic atoms in 1d traps. We consider systems both with and without an optical lattice and address different approximations in stochastic synthesization of quantum statistical correlations of the initial atomic field operator. We also present a numerically efficient projection method for analyzing correlation functions of the simulation results. Physical examples demonstrate non-equilibrium quantum dynamics of solitons and atom number squeezing in optical lattices in which case we, e.g., numerically track the soliton coordinates and calculate quantum mechanical expectation values and uncertainties for the position of the soliton.
D1D5 System and Noncommutative Geometry
Mikhailov, A
2000-01-01
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.
Fermiology of a 1D heavy electron metal
Gröber, C
1999-01-01
We present a Quantum Monte Carlo (QMC) study of the 1D Kondo lattice at non-integer filling, i.e. a one-dimensional version of a heavy electron metal. For this special system the minus-sign problem turns out to be strongly reduced, which allows QMC simulations for temperatures as low as 1% of the conduction electron bandwidth. The single particle Green's function shows and intricate network of low-energy bands at low temperature, with a Fermi surface volume that comprises both c and f-electrons. As temperature increases the system evolves through two distinct crossover temperatures into a very simple band structure with one free c-electron band and a disconnected upper and lower Hubbard band for f-electrons. The f-electrons thus `drop out' of the Fermi surface volume as temperature increases.
1-D array of perforated diode neutron detectors
McNeil, Walter J.; Bellinger, Steven L.; Unruh, Troy C.; Henderson, Chris M.; Ugorowski, Phil; Morris-Lee, Bryce; Taylor, Russell D.; McGregor, Douglas S.
2009-06-01
Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 ?m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with 6LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.
A 1-D model for highly sensitive tubular reactors
Energy Technology Data Exchange (ETDEWEB)
Hagan, P.S.; Herskowitz, M.; Pirkle, J.C.
1987-01-01
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.
Slab detachment - 3-D versus 1-D & 2-D
von Tscharner, Marina; Duretz, Thibault; Schmalholz, Stefan
2014-05-01
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
𝒟(?)lentiginosine-induced apoptosis involves the intrinsic pathway and is p53-independent
Minutolo, A; Grelli, S; Marino-Merlo, F; Cordero, F M; Brandi, A; Macchi, B; Mastino, A
2012-01-01
We have recently found that 𝒟(?)lentiginosine, a synthetic iminosugar exerting glucosidase inhibitory activity, but not its natural enantiomer lentiginosine, is endowed with an unexpected, pro-apoptotic activity. Here, we investigated mechanisms involved in apoptosis induced by 𝒟?)lentiginosine in MOLT-3, HT-29 and SH-SY5Y tumour cell lines. The results showed that 𝒟?)lentiginosine increased caspase 9 expression at 18?h in all the cell lines from 1.5–3.1 folds. Cytochrome c in the cytoplasm was found to be increased from 2.3–2.6 folds in treated cells with respect to control cells. These effects were accompanied by a remarkable collapse of the mitochondrial membrane potential and by the downregulation of anti-apoptotic genes, as well as the upregulation of pro-apoptotic genes of the Bcl-2 family. U937Bcl-2 transfectants, highly expressing Bcl-2, were reluctant to undergo apoptosis even following treatment with 500??M 𝒟?)lentiginosine, whereas apoptosis by 𝒟?)lentiginosine was induced also in U937 cells, naturally deficient in P53. Thus, our study establishes that the enantiomer of a natural iminosugar is endowed with a possible anti-tumorigenic effect that might be ascribed not only to their capacity to inhibit glycosidases but also to other unknown mechanisms. These data encourage further investigation on similar compounds to make them an interesting platform for the generation of new anticancer drugs. PMID:22833097
García-Cazarín, Mary L; Smith, Jennifer L; Clair, Daret K St; Piascik, Michael T
2008-10-01
Activation of the endogenous alpha1-adrenergic receptor (AR) associated with human aortic smooth muscle cells resulted in a dose- and time-dependent increase in the levels of mitochondrial reactive oxygen species (ROS). ROS increases were apparent within 10 min and maximal after 45 min. Prolonged activation (>4 h) of the alpha1-AR resulted in smooth muscle cell apoptosis. Both the increase in ROS and apoptotic cell death were blocked by the nonselective alpha1-AR antagonist prazosin as well as the selective alpha1D-AR antagonist 8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7, 9-dione (BMY 7378). Increases in ROS and apoptosis produced by alpha1-AR activation were also blocked by the p38 mitogen-activated protein kinase inhibitor 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole (SB 202190) and the NAPDH oxidase inhibitor apocynin. The extracellular signal-regulated kinase 1/2 inhibitor 2'-amino-3'-methoxyflavone (PD 98059) or the c-Jun NH2-terminal kinase inhibitor 1, 9-pyrazoloanthrone anthra(1, 9-cd)pyrazol-6(2H)-one (SP 600125) was without effect on increases in ROS levels or apoptosis. Pifithrin-alpha, an inhibitor of the tumor suppressor protein p53, had no effect on ROS generation but did block alpha1D-AR-induced apoptosis. Activation of the alpha1D-AR resulted in translocation of p53 to the mitochondria. The mitochondrial translocation of p53 was blocked by prazosin, BMY 7378, apocynin, SB 202190, and pifithrin-alpha. Apoptosis was also blocked by small interfering RNA directed against p53. These data show that the alpha1D-AR is coupled to the generation of mitochondrial ROS by a pathway involving p38 and NADPH oxidase. Sustained activation of the alpha1D-AR results in smooth muscle cell apoptosis in a pathway that involves the tumor suppressor protein p53 and the mitochondrial translocation of p53. The data also provide evidence of a linkage between the alpha1D-AR and p53. PMID:18628404
Gorelova, Natalia; Seamans, Jeremy K.
2015-01-01
The persistent Na+ current (INap) is believed to be an important target of dopamine modulation in prefrontal cortex (PFC) neurons. While past studies have tested the effects of dopamine on INap, the results have been contradictory largely because of difficulties in measuring INap using somatic whole-cell recordings. To circumvent these confounds we used the cell-attached patch-clamp technique to record single Na+ channels from the soma, proximal dendrite (PD) or proximal axon (PA) of intact prefrontal layer V pyramidal neurons. Under baseline conditions, numerous well resolved Na+ channel openings were recorded that exhibited an extrapolated reversal potential of 73 mV, a slope conductance of 14–19 pS and were blocked by tetrodotoxin (TTX). While similar in most respects, the propensity to exhibit prolonged bursts lasting >40 ms was many fold greater in the axon than the soma or dendrite. Bath application of the D1/D5 receptor agonist SKF81297 shifted the ensemble current activation curve leftward and increased the number of late events recorded from the PD but not the soma or PA. However, the greatest effect was on prolonged bursting where the D1/D5 receptor agonist increased their occurrence 3 fold in the PD and nearly 7 fold in the soma, but not at all in the PA. As a result, D1/D5 receptor activation equalized the probability of prolonged burst occurrence across the proximal axosomatodendritic region. Therefore, D1/D5 receptor modulation appears to be targeted mainly to Na+ channels in the PD/soma and not the PA. By circumventing the pitfalls of previous attempts to study the D1/D5 receptor modulation of INap, we demonstrate conclusively that D1/D5 receptor activation can increase the INap generated proximally, however questions still remain as to how D1/D5 receptor modulates Na+ currents in the more distal initial segment where most of the INap is normally generated. PMID:25729354
1D nonnegative Schrodinger operators with point interactions
Directory of Open Access Journals (Sweden)
Yu. G. Kovalev
2013-07-01
Full Text Available Let $Y$ be an infinite discrete set of points in $dR$,satisfying the condition $inf{|y-y'|,; y,y'in Y, y'ey}>0.$ In the paper we prove that the systems${delta(x-y}_{yin Y}, ;{delta'(x-y}_{yin Y},{delta(x-y,;delta'(x-y}_{yin Y}$ {form Riesz} bases in the corresponding closed linear spans in the Sobolev spaces $W_2^{-1}(dR$ and $W_2^{-2}(dR$. As an application, we prove the transversalness of the Friedrichs and Kreui n nonnegative selfadjoint extensions of the nonnegative symmetric operators $A_0$, $A'$, and $H_0$ defined {as restrictions} of the operator $A =-frac{ d^2}{ dx^2},$ $dom (A=W^2_2(dR${to} the linear manifolds $dom (A_0=left{ finW_2^2(mathbb{R}colon f(y=0,; yin Y ight}$, $dom(A'={ gin W_2^2(mathbb{R}colon g'(y=0,; yin Y },$ and$dom (H_0=left{fin W_2^2(mathbb{R}colonf(y=0,;f'(y=0,; yin Y ight}$, respectively. Using thedivergence forms, the basic nonnegative boundary triplets for$A^*_0$, $A'^*$, and $H^*_0$ are constructed.
Electrodeposition of photoactive 1D gallium selenide quantum dots
International Nuclear Information System (INIS)
One-dimensional (1D) quantum dots of gallium selenide have been obtained by cathodic electrodeposition onto the tin doped indium oxide (ITO) glass substrates from aqueous acidic solutions at room temperature. Characterizations of the as-deposited films by energy dispersive X-ray (EDX) spectroscopy confirm a selenium rich chemistry, X-ray diffraction (XRD) shows that mixture of phases like GaSe/Ga2Se3, and optical spectroscopy shows a direct optical band gap of 2.85 eV with intermediate transition energy at 1.9 eV. From transmission electron microscopy (TEM), the films show the one-dimensional quantum dots chains in grains. Scanning electron microscopy (SEM) images indicate dimorphous placement of nanoparticles. The elementals surface analysis of the core-shell nanoparticles determined by X-ray photoelectron spectroscopy (XPS) supported the EDX results and confirmed the chemical nature of the material. The photoelectrochemical (PEC) studies of gallium selenide films were carried out and the nanocrystalline gallium selenide films were found to be photoactive in aqueous sodium thiosulphate solution
Quantum Heat Engines; Multiple-State 1D Box System
Directory of Open Access Journals (Sweden)
Eny Latifah
2013-08-01
Full Text Available We evaluate quantum Otto, Diesel and Brayton cycles employing multiple-state 1D box system instead of ideal gas filled cylinder. The work and heat are extracted using the change in the expectation of Hamiltonian of the system which leads to the first law of thermodynamics to quantum system. The first law makes available to redefine the force which is in fact not well defined in a quantum mechanical system and then it is applied to define the quantum version of thermodynamic processes, i.e. isobaric, isovolume and adiabatic. As the results, the efficiency of quantum Otto engine depends only on the compression ratio and will be higher than the efficiency of quantum Diesel which can decrease by the widening of expansion under isobaric process. The efficiency of quantum Brayton engine may reach maximum on certain combination between the wide of box under isobaric expansion and compression, under certain conditions. The amount of levels participated in the quantum heat engine system will potentially reduce the performance of the quantum heat cycles consisting isobaric process, but it can be resisted using isobaric process controller.
Dynamical functions of a 1D correlated quantum liquid
International Nuclear Information System (INIS)
The dynamical correlation functions in one-dimensional electronic systems show power-law behaviour at low energies and momenta close to integer multiples of the charge and spin Fermi momenta. These systems are usually referred to as Tomonaga-Luttinger liquids. However, near well defined lines of the (k,?) plane the power-law behaviour extends beyond the low-energy cases mentioned above, and also appears at higher energies, leading to singular features in the photoemission spectra and other dynamical correlation functions. The general spectral-function expressions derived in this paper were used in recent theoretical studies of the finite-energy singular features in photoemission of the organic compound tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) metallic phase. They are based on a so-called pseudofermion dynamical theory (PDT), which allows us to systematically enumerate and describe the excitations in the Hubbard model starting from the Bethe ansatz, as well as to calculate the charge and spin object phase shifts appearing as exponents of the power laws. In particular, we concentrate on the spin-density m?0 limit and on effects in the vicinity of the singular border lines, as well as close to half filling. Our studies take into account spectral contributions from types of microscopic processes that do not occur for finite values of the spin density. In addition, the specific processes involved in the spectral features of TTF-TCNQ are studied. Our resultres of TTF-TCNQ are studied. Our results are useful for the further understanding of the unusual spectral properties observed in low-dimensional organic metals and also provide expressions for the one- and two-atom spectral functions of a correlated quantum system of ultracold fermionic atoms in a 1D optical lattice with on-site two-atom repulsion
Fabrication of GaN/AlGaN 1D photonic crystals designed for nonlinear optical applications
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
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...
Fabrication of GaN/AlGaN 1D photonic crystals designed for nonlinear optical applications
Stomeo, T.; Epifani, G.; Tasco, V.; Tarantini, I.; Campa, A.; Vittorio, M.; Passaseo, A.; Braccini, M.; Larciprete, M. C.; Sibilia, C.; Bovino, F. A.
2011-01-01
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 ep...
Photodissociation of NO2 in the (2) 2B2 state: The O(1D2) dissociation channel
International Nuclear Information System (INIS)
Direct current slice and crush velocity map imaging has been used to probe the photodissociation dynamics of nitrogen dioxide above the second dissociation limit. The paper is a companion to a previous publication [J. Chem. Phys. 128, 164318 (2008)] in which we reported results for the O(3PJ)+NO(2??) adiabatic product channel. Here we examine the O(1D2)+NO(2??) diabatic product channel at similar excitation energies. Using one- and two-color imaging experiments to observe the velocity distributions of state selected NO fragments and O atoms, respectively, we are able to build a detailed picture of the dissociation dynamics. We show that by combining the information obtained from velocity map imaging studies with mass-resolved resonantly enhanced multiphoton ionization spectroscopy it is possible to interpret and fully assign the NO images. By recording two-color images of the O(1D2) photofragments with different polarization combinations of the pump and probe laser fields we also measure the orbital angular momentum alignment in the atomic fragment. We find that the entire O(1D2) photofragment distribution is similarly aligned with most of the population in the MJ=±1 magnetic sublevels. The similarity of the fragment polarizations is interpreted as a signature of all of the O(1D2) atoms being formed vp>D2) atoms being formed via the same avoided crossing. At the photolysis energy of 5.479 52 eV we find that the NO fragments are preferentially formed in v=1 and that the vibrationally excited fragments exhibit a bimodal rotational distribution. This is in contrast to the unimodal rotational profile of the NO fragments in v=0. We discuss these observations in terms of the calculated topology of the adiabatic potential energy surfaces and attribute the vibrational inversion and rotational bimodality of the v=1 fragments to the symmetric stretch and bending motion generated on excitation to the (2) 2B2 state.
Zhang, Qingfu; Geng, Aijing; Zhang, Haina; Hu, Falu; Lu, Zhang-Hui; Sun, Dezhi; Wei, Xilian; Ma, Chunlin
2014-04-22
The syntheses and structures of two new Zn(II) complexes, a 2D graphite-like layer {[Zn(PIA)H2 O]?H2 O}n (1) and an independent 1D single-walled metal-organic nanotube (SWMONT) {[Zn2 (PIA)2 (bpy)2 ]?2.5?H2 O?DMA}n (2), have been reported based on a "Y"-shaped 5-(pyridine-4-yl)isophthalic acid ligand (H2 PIA). Interestingly, the 2D graphite-like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2'-bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal-organic nanotube generated from a 2D layer by a "rolling-up" mechanism. PMID:24648263
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
Although the dopamine D1-D2 receptor heteromer has emerging physiological relevance and a postulated role in different neuropsychiatric disorders, such as drug addiction, depression, and schizophrenia, there is a need for pharmacological tools that selectively target such receptor complexes in order to analyze their biological and pathophysiological functions. Since no selective antagonists for the D1-D2 heteromer are available, serial deletions and point mutations were used to precisely identify the amino acids involved in an interaction interface between the receptors, residing within the carboxyl tail of the D1 receptor that interacted with the D2 receptor to form the D1-D2 receptor heteromer. It was determined that D1 receptor carboxyl tail residues (404)Glu and (405)Glu were critical in mediating the interaction with the D2 receptor. Isolated mutation of these residues in the D1 receptor resulted in the loss of agonist activation of the calcium signaling pathway mediated through the D1-D2 receptor heteromer. The physical interaction between the D1 and D2 receptor could be disrupted, as shown by coimmunoprecipitation and BRET analysis, by a small peptide generated from the D1 receptor sequence that contained these amino acids, leading to a switch in G-protein affinities and loss of calcium signaling, resulting in the inhibition of D1-D2 heteromer function. The use of the D1-D2 heteromer-disrupting peptide in vivo revealed a pathophysiological role for the D1-D2 heteromer in the modulation of behavioral despair. This peptide may represent a novel pharmacological tool with potential therapeutic benefits in depression treatment. PMID:25063849
Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint
Energy Technology Data Exchange (ETDEWEB)
McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.
2012-06-01
To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.
Exercise increases TBC1D1 phosphorylation in human skeletal muscle
DEFF Research Database (Denmark)
Jessen, Niels; An, Ding
2011-01-01
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.
1D engine simulation of a turbocharged SI engine with CFD computation on components
Renberg, Ulrica
2008-01-01
Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization. This thesis concerns 1D engine simulation of a turbocharged SI engine and the introduction of CFD computations on components as a way to assess inaccuracies in the 1D model. 1D engine ...
Twisted N=1, d=4 supergravity and its symmetries
International Nuclear Information System (INIS)
We display the construction of a twisted superalgebra for the N=1 Euclidean supergravity on 4-manifolds with an almost complex structure. It acts on a representation of twisted supersymmetry made of forms with odd and even statistics and it is covariant under a U(2)?SO(4) Lorentz invariance of the manifold's tangent-space. It contains 4 twisted supersymmetry generators, one nilpotent scalar, one vector and one pseudo-scalar. The superalgebra closes on the twisted fields of supergravity in its new minimal set of auxiliary fields. Its couplings to the twisted Wess and Zumino and vector multiplets are also determined.
Twisted N=1, d=4 supergravity and its symmetries
Baulieu, Laurent; Bellon, Marc; Reys, Valentin
2013-02-01
We display the construction of a twisted superalgebra for the N=1 Euclidean supergravity on 4-manifolds with an almost complex structure. It acts on a representation of twisted supersymmetry made of forms with odd and even statistics and it is covariant under a U(2)?SO(4) Lorentz invariance of the manifold's tangent-space. It contains 4 twisted supersymmetry generators, one nilpotent scalar, one vector and one pseudo-scalar. The superalgebra closes on the twisted fields of supergravity in its new minimal set of auxiliary fields. Its couplings to the twisted Wess and Zumino and vector multiplets are also determined.
Processing of seismograms with vibration transillumination
Energy Technology Data Exchange (ETDEWEB)
Magnitskaya, N.N.; Nikolayev, A.V.
1983-01-01
The use of low power vibration sources in seismic transilluminations is linked to recording of signals whose intensity is much less than the level of the background microseismic interferences. The problem developing in this case of amplitude rarefaction, ''compression'' of the signal is solved in practice by correlation processing of the vibrograms. A serious restriction for this method is the correlation noise which develops during the processing. Control of this noise which reduces the amplitude resolution and diminishes the signal/multiplicative interference ratio can occur in different ways: by selecting special probing signals which have low level of correlation noise, and by using special algorithms for processing the vibrograms. One of these algorithms is described.
Directory of Open Access Journals (Sweden)
José Alexandre de França
2011-06-01
Full Text Available Na visão computacional, a calibração de câmeras é um processo necessário quando deseja-se recuperar informações como, por exemplo, ângulos e distâncias. O presente trabalho trata do problema de calibração de câmeras com gabaritos de uma única dimensão. Atualmente, tal problema só tem solução se forem impostas restrições ao movimento do gabarito ou se alguns parâmetros das câmeras já sejam previamente conhecidos. Contudo, demonstra-se que uma abordagem diferente pode ser aplicada se, ao invés de uma única câmera, um conjunto binocular for considerado. Nesse caso, a calibração é possível com um gabarito 1D que realiza um deslocamento desconhecido e sem restrições, mesmo sem nenhuma informação prévia a respeito das câmeras. Tal método baseia-se na estimação de uma transformação que, após a estimação da matriz fundamental do sistema, permite atualizar uma calibração projetiva para uma calibração euclidiana. Experimentos em imagens reais e sintéticas validam o novo método e mostram que a sua exatidão é comparável a de outros métodos clássicos de calibração, já bem conhecidos na literatura.In computer vision, the camera calibration is a process needed when the recovery of some information, such as angles and distances, is desired. The present work deals with the problem of camera calibration using one-dimensional patterns. Nowadays, this problem only has a solution if some restrictions to the pattern's movement are imposed or if some angles of the cameras are known in advance. However, a different approach can be applied if, instead of only one camera, a stereo system is considered. In that case, the calibration is possible with a one-dimensional pattern that executes an unknown and unrestricted movement, even without any previous information concerning the cameras. Such method is based on the estimation of a transform which, after the estimation of the system's fundamental matrix, allows updating a projective calibration into a Euclidean calibration. Experiments using both real and synthetic images validate the new method and demonstrate that its accuracy is comparable to other well known calibration methods in the literature.
Scientific Electronic Library Online (English)
José Alexandre de, França; Maria Bernadete de M., França; Marcelo Ricardo, Stemmer; Rodrigo Henrique C., Palácios.
2011-06-01
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.
International Nuclear Information System (INIS)
Organic anion transporting polypeptides (rodent Oatp; human OATP) mediate cellular uptake of numerous organic compounds including xenobiotic toxins into mammalian hepatocytes. In the little skate Leucoraja erinacea a liver-specific Oatp (Oatp1d1, also called sOatp) has been identified and suggested to represent an evolutionarily ancient precursor of the mammalian liver OATP1B1 (human), Oatp1b2 (rat), and OATP1B3 (human). The present study tested whether Oatp1d1 shares functional transport activity of the xenobiotic oligopeptide toxins phalloidin and microcystin with the mammalian liver Oatps/OATPs. The phalloidin analogue [3H]-demethylphalloin was taken up into skate hepatocytes with high affinity (Km ? 0.4 ?M), and uptake could be inhibited by phalloidin and a variety of typical Oatp/OATP substrates such as bromosulfophthalein, bile salts, estrone-3-sulfate, cyclosporine A and high concentrations of microcystin-LR (Ki ? 150 ?M). When expressed in Xenopus laevis oocytes Oatp1d1 increased uptake of demethylphalloin (Km ? 2.2 ?M) and microcystin-LR (Km ? 27 ?M) 2- to 3-fold over water-injected oocytes, whereas the alternative skate liver organic anion transporter, the dimeric Ost?/?, exhibited no phalloidin and only minor microcystin-LR transport. Also, the closest mammalian Oatp1d1 orthologue, the human brain and testis OATP1C1, did not show any phalloidin transport activity. These results demonstrate that the evolutionarily ancient Oatp1d1 is ionarily ancient Oatp1d1 is able to mediate uptake of cyclic oligopeptide toxins into skate liver. The findings support the notion that Oatp1d1 is a precursor of the liver-specific mammalian Oatps/OATPs and that its transport properties are closely associated with certain forms of toxic liver injury such as for example protein phosphatase inhibition by the water-borne toxin microcystin
The role of river flow and tidal asymmetry on 1-D estuarine morphodynamics
Guo, L.; Wegen, M.; Roelvink, J. A.; He, Q.
2014-11-01
Numerous research efforts have been devoted to understanding estuarine morphodynamics under tidal forcing. However, the impact of river discharge on estuarine morphodynamics is insufficiently examined. Inspired by the Yangtze Estuary, this work explores the morphodynamic impact of river discharge in a 560 km long tidal basin based on a 1-D model (Delft3D). The model considers total load sediment transport and employs a morphodynamic updating scheme to achieve long-term morphodynamic evolution. We analyze the role of Stokes drift, tidal asymmetry, and river discharge in generating tidal residual sediment transport. Model results suggest that morphodynamic equilibrium is approached within millennia by vanishing spatial gradients of tidal residual sediment transport. We find that the interaction between ebb-directed Stokes return flow/river flow with tides is an important mechanism that flushes river-supplied sediment seaward. Increasing river discharge does not induce continuously eroded or accreted equilibrium bed profiles because of the balance between riverine sediment supply and sediment flushing to the sea. An intermediate threshold river discharge can be defined which leads to a deepest equilibrium bed profile. As a result, the shape (concavity or convexity) of the equilibrium bed profiles will adapt with the magnitude of river discharge. Overall, this study reveals the significant role of river discharge in controlling estuarine morphodynamics by supplying sediment and reinforcing ebb-directed residual sediment transport.
Surface roughened 1-D Au host nanorods for visible light induced photocatalyst
International Nuclear Information System (INIS)
Highlights: • Surface roughened 1-D Au host nanorods for visible light induced photocatalyst are tried. • A nanofilm of hematite coated on high conducting and vertically aligned smooth Au nanorods or nanoporous Au nanorods is prepared. • We report an effect of surface morphology of Au nanorods on the photoactivity of hematite/gold nanorod arrays prepared by the electrodeposition method. -- Abstract: Visible light induced photocatalytic degradation of rhodamine B and hydrogen generation from solar water splitting by hematite (?-Fe2O3) coated gold (Au) nanorods have been investigated, in which two types of ?-Fe2O3/Au nanorods with different Au surfaces were synthesized and then carefully compared. Vertically aligned smooth Au nanorod and porous Au nanorod arrays were prepared by the electro-deposition method using anodized aluminum oxide templates, followed by deposition of hematite onto nanoporous Au nanorods and smooth Au nanorods to synthesize core/shell like nanostructure. The as-prepared samples were characterized by Field Emission Scanning Electron Microscopy, X-ray Diffraction, and X-ray Photoelectron Spectroscopy. Also, their photocatalytic activities were investigated by photo-degradation of rhodamine B, photocurrent–voltage, and incident photon to current conversion efficiency measurements under AM 1.5G light irradiation. Hematite (?-Fe2O3) coated porous Au nanorods showed better photocatalytic activities than ?-Fe2O3 coated smooth Au nanorods, showing faster dye degradation rate, higher photocurrent density and better photon harvesting
Two step procedure by using a 1-D slab spectral geometry for a pebble bed reactor core analysis
International Nuclear Information System (INIS)
In this paper, we demonstrate a two step procedure for a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. In the second step, we perform a diffusion calculation by using the equivalent cross sections generated in the first step. A simple 2-D benchmark problem derived from the PMBR-400 reactor was introduced to verify the two step procedure. We compared the two step solutions with the Monte Carlo solutions for the problem and found that the two step solutions agreed well with the Monte Carlo solutions within an acceptable error range. (authors)
Synthesis of all Stereoisomers of KRN7000, the CD1d-binding NKT Cell Ligand
Park, Jeong-ju; Lee, Ji Hyung; Ghosh, Subhash Ch; Bricard, Gabriel; Venkataswamy, Manjunatha M.; Porcelli, Steven A.; Chung, Sung-kee
2008-01-01
KRN7000 is an important ligand identified for CD1d protein of APC, and KRN7000/CD1d complex can stimulate NKT cells to release Th1 and Th2 cytokines. In an effort to understand the structure-activity relationships, we have carried out the synthesis of a complete set of the KRN7000 stereoisomers, and their biological activities examined.
A rational route to SCM materials based on a 1-D cobalt selenocyanato coordination polymer.
Boeckmann, Jan; Näther, Christian
2011-07-01
Thermal annealing of a discrete complex with terminal SeCN anions and monodentate coligands enforces the formation of a 1D cobalt selenocyanato coordination polymer that shows slow relaxation of the magnetization. Therefore, this approach offers a rational route to 1D materials that might show single chain magnetic behaviour. PMID:21617809
Development of a 3D consistent 1D neutronics model for reactor core simulation
International Nuclear Information System (INIS)
In this report a 3D consistent 1D model based on nonlinear analytic nodal method is developed to reproduce the 3D results. During the derivation, the current conservation factor (CCF) is introduced which guarantees the same axial neutron currents obtained from the 1D equation as the 3D reference values. Furthermore in order to properly use 1D group constants, a new 1D group constants representation scheme employing tables for the fuel temperature, moderator density and boron concentration is developed and functionalized for the control rod tip position. To test the 1D kinetics model with CCF, several steady state and transient calculations were performed and compared with 3D reference values. The errors of K-eff values were reduced about one tenth when using CCF without significant computational overhead. And the errors of power distribution were decreased to the range of one fifth or tenth at steady state calculation. The 1D kinetics model with CCF and the 1D group constant functionalization employing tables as a function of control rod tip position can provide preciser results at the steady state and transient calculation. Thus it is expected that the 1D kinetics model derived in this report can be used in the safety analysis, reactor real time simulation coupled with system analysis code, operator support system etc.
Energy Technology Data Exchange (ETDEWEB)
Ozaki, N.; Lappalainen, J.; Linnoila, M. [National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (United States)] [and others
1995-04-24
Serotonin (5-HT){sub ID} receptors are 5-HT release-regulating autoreceptors in the human brain. Abnormalities in brain 5-HT function have been hypothesized in the pathophysiology of various psychiatric disorders, including obsessive-compulsive disorder, autism, mood disorders, eating disorders, impulsive violent behavior, and alcoholism. Thus, mutations occurring in 5-HT autoreceptors may cause or increase the vulnerability to any of these conditions. 5-HT{sub 1D{alpha}} and 5-HT{sub 1D{Beta}} subtypes have been previously localized to chromosomes 1p36.3-p34.3 and 6q13, respectively, using rodent-human hybrids and in situ localization. In this communication, we report the detection of a 5-HT{sub 1D{alpha}} receptor gene polymorphism by single strand conformation polymorphism (SSCP) analysis of the coding sequence. The polymorphism was used for fine scale linkage mapping of 5-HT{sub 1D{alpha}} on chromosome 1. This polymorphism should also be useful for linkage studies in populations and in families. Our analysis also demonstrates that functionally significant coding sequence variants of the 5-HT{sub 1D{alpha}} are probably not abundant either among alcoholics or in the general population. 14 refs., 1 fig., 1 tab.
Identification of RAPD Marker for Chromosome 1D of Common Wheat
Directory of Open Access Journals (Sweden)
Imtiaz Ahmad Khan
2010-04-01
Full Text Available Development of genetically compensating nullisomic-tetrasomic and ditelosomic lines of commonwheat (Triticum aestivum L. have been widely used to construct high density genetic maps of homoeologouswheat chromosomes. During present research, easier, cheaper and quicker procedure of Polymerase ChainReaction (PCR was used to map Randomly Amplified Polymorphic DNA primers on chromosome 1D ofcommon wheat. Genomic DNA was isolated from two genetic stocks of wheat cultivar Chinese Spring viz;NT-1D1B and NT-2A2B. PCR were conducted using RAPD primers GLC-07 and GLC-11. RAPD primerGLC-11 amplified a polymorphic allele of approximately 500 bp, which was present in NT-2A2B (used aspositive control but was absent in NT-1D1B indicating that the locus is present on chromosome 1D of commonwheat. Hence this marker (GLC-11 can reliably be used to keep track of chromosome 1D of hexaploid wheat.
PIH1D1, a subunit of R2TP complex, inhibits doxorubicin-induced apoptosis.
Inoue, Mika; Saeki, Makio; Egusa, Hiroshi; Niwa, Hitoshi; Kamisaki, Yoshinori
2010-12-17
We have previously reported that the two components of R2TP complex, RNA polymerase II-associated protein 3 (RPAP3), and Reptin, regulate apoptosis. Here we characterize another component of the complex, PIH1 domain containing protein 1 (PIH1D1). PIH1D1 interacts with both RPAP3 and Monad in HEK293 or U2OS cells. PIH1D1 transcripts were abundant in lung, leukocyte, and placenta. The reduction in endogenous PIH1D1 by siRNA enhanced apoptosis and caspase-3 activation induced by doxorubicin in U2OS cells. These results suggest that PIH1D1 may also function as a novel modulator of apoptosis pathway. PMID:21078300
ASOP, Shield Calculation, 1-D, Discrete Ordinates Transport
International Nuclear Information System (INIS)
1 - Nature of physical problem solved: ASOP is a shield optimization calculational system based on the one-dimensional discrete ordinates transport program ANISN. It has been used to design optimum shields for space applications of SNAP zirconium-hydride-uranium- fueled reactors and uranium-oxide fueled thermionic reactors and to design beam stops for the ORELA facility. 2 - Method of solution: ASOP generates coefficients of linear equations describing the logarithm of the dose and dose-weight derivatives as functions of position from data obtained in an automated sequence of ANISN calculations. With the dose constrained to a design value and all dose-weight derivatives required to be equal, the linear equations may be solved for a new set of shield dimensions. Since changes in the shield dimensions may cause the linear functions to change, the entire procedure is repeated until convergence is obtained. The detailed calculations of the radiation transport through shield configurations for every step in the procedure distinguish ASOP from other shield optimization computer code systems which rely on multiple component sources and attenuation coefficients to describe the transport. 3 - Restrictions on the complexity of the problem: Problem size is limited only by machine size
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)
Comparison of 1D and 2D modelling with soil erosion model SMODERP
Kavka, Petr; Weyskrabova, Lenka; Zajicek, Jan
2013-04-01
The contribution presents a comparison of a runoff simulated by profile method (1D) and spatially distributed method (2D). Simulation model SMODERP is used for calculation and prediction of soil erosion and surface runoff from agricultural land. SMODERP is physically based model that includes the processes of infiltration (Phillips equation), surface runoff (kinematic wave based equation), surface retention, surface roughness and vegetation impact on runoff. 1D model was developed in past, new 2D model was developed in last two years. The model is being developed at the Department of Irrigation, Drainage and Landscape Engineering, Civil Engineering Faculty, CTU in Prague. 2D model was developed as a tool for widespread GIS software ArcGIS. The physical relations were implemented through Python script. This script uses ArcGIS system tools for raster and vectors treatment of the inputs. Flow direction is calculated by Steepest Descent algorithm in the preliminary version of 2D model. More advanced multiple flow algorithm is planned in the next version. Spatially distributed models enable to estimate not only surface runoff but also flow in the rills. Surface runoff is described in the model by kinematic wave equation. Equation uses Manning roughness coefficient for surface runoff. Parameters for five different soil textures were calibrated on the set of forty measurements performed on the laboratory rainfall simulator. For modelling of the rills a specific sub model was created. This sub model uses Manning formula for flow estimation. Numerical stability of the model is solved by Courant criterion. Spatial scale is fixed. Time step is dynamically changed depending on how flow is generated and developed. SMODERP is meant to be used not only for the research purposes, but mainly for the engineering practice. We also present how the input data can be obtained based on available resources (soil maps and data, land use, terrain models, field research, etc.) and how can the model be used in the assessments of soil erosion risk and in designing of erosion control measures. The research has been supported by the research grants SGS SGS11/148/OHK1/3T/11 "Experimental Research on Rainfall-runoff and Erosion Processes" and by Project No. TA02020647 " Atlas EROZE - a modern tool for soil erosion assessment".
Light-directing chiral liquid crystal nanostructures: from 1D to 3D.
Bisoyi, Hari Krishna; Li, Quan
2014-10-21
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
Energy Technology Data Exchange (ETDEWEB)
Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Su, Xiong [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Liu, Jialiu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Sundaresan, Sinju [Department of Internal Medicine, Center for Human Nutrition Washington University School of Medicine, St. Louis, MO 63110 (United States); Stahl, Philip D., E-mail: pstahl@wustl.edu [Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110 (United States)
2013-05-03
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.
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
Structure and Catalytic Mechanism of Human Steroid 5-Reductase (AKR1D1)
Energy Technology Data Exchange (ETDEWEB)
Costanzo, L.; Drury, J; Christianson, D; Penning, T
2009-01-01
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.
The FC-1D: The profitable alternative Flying Circus Commercial Aviation Group
Meza, Victor J.; Alvarez, Jaime; Harrington, Brook; Lujan, Michael A.; Mitlyng, David; Saroughian, Andy; Silva, Alex; Teale, Tim
1994-01-01
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.
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.
Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids
Energy Technology Data Exchange (ETDEWEB)
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
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.
Growth and Magnetic characterization of 1D Permalloy Nanowires using self developed AAO Templates
Singh, A. K.; Khan, G. G.; Das, B.; Mandal, K.
2015-02-01
1D Permalloy refers to an alloy of Ni and Fe with 80% and 20% composition respectively. 1D Permalloy nanowires are particularly attractive because of their high permeability, low coercivity, near zero magnetostriction and high anisotropic magnetoresistance. Because of low magnetostriction of Permalloy shape anisotropy plays a very important role. As a result, the nanowires show unidirectional anisotropy along their length. Because of this property, they can be used in many applications such as recording head sensors, magnetic storage devices etc. In the present work 1D Permalloy nanowires arrays were fabricated into the pores of self engineered Anodic Aluminium Oxide (AAO) templates by a simple electrodeposition technique (EDT). By varying the Anodization voltage and the parameters of the electrolytic solutions we developed various AAO templates with different average pore diameters. We developed the 1D Permalloy NW's of different diameters depending on the pore size arrangement of AAO templates by varying the deposition conditions. Structural characterization of AAO templates and 1D Permalloy NW's was performed by Transmission and Scanning Electron Microscopy (TEM & SEM). XRD studies of 1D Permalloy NW's shows their fcc crystalline structure and the AAO template was found to be amorphous in nature. Magnetic studies show the 1D Permalloy NW's arrays to have obvious anisotropy, and the easy axis was found to be parallel to the nanowires axis. We performed the angular dependence measurement of 1D Permalloy NW's. When the applied magnetic field was parallel to the nanowires, the coercivity (Hc) and the maximum remanent ratio (Mr/Ms) were considerably higher than those while the magnetic field perpendicular to the nanowires. 1D Permalloy NW's developed in this work are expected to be utilize in magnetic memory and magnetic recording devices.
Temperature-dependence of a 1D interface fluctuations: role of a finite disorder correlation length
Agoritsas, Elisabeth
2013-01-01
Experimental realizations of a one-dimensional (1D) interface always exhibit a finite microscopic width and/or a disorder correlation length. We study analytically and numerically the geometrical fluctuations of a static 1D interface with a short-range elasticity, submitted to a quenched random-bond Gaussian disorder of finite disorder correlation length, and at finite temperature. Using the exact mapping from the static 1D interface to the 1+1 Directed Polymer (DP) growing in a continuous sp...
A conservative strategy to couple 1D and 2D models for shallow water flow simulation
Morales-herna?ndez, M.; Garci?a-navarro, P.; Burguete Tolosa, Javier; Brufau, P.
2013-01-01
A 1D–2D coupled numerical model is presented in this work. 1D and 2D models are formulated using a conservative upwind cell-centred finite volume scheme. The discretization is based on cross-sections for the 1D model and with triangular unstructured grid for the 2D model. The resulting element of discretization for the coupled model is analysed and two different coupling techniques based on mass conservation and mass and momentum conservation respectively are explored, considering both fron...
The Deuteron Spin-dependent Structure Function g1d and its First Moment
Compass, The Collaboration; Alexakhin, V. Yu
2006-01-01
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 Gamma_1^d, the first moment of g1d(x), and for the matrix element of the singlet axial current, a0. The results of QCD fits in the next to leading order (NLO) on all g1 deep inelastic scattering data are also presented. They provide two solutions with the gluon spin...
Two Step Procedure Using a 1-D Slab Spectral Geometry in a Pebble Bed Reactor Core Analysis
International Nuclear Information System (INIS)
A strong spectral interaction between the core and the reflector has been one of the main concerns in the analysis of pebble bed reactor cores. To resolve this problem, VSOP adopted iteration between the spectrum calculation in a spectral zone and the global core calculation. In VSOP, the whole problem domain is divided into many spectral zones in which the fine group spectrum is calculated using bucklings for fast groups and albedos for thermal groups from the global core calculation. The resulting spectrum in each spectral zone is used to generate broad group cross sections of the spectral zone for the global core calculation. In this paper, we demonstrate a two step procedure in a pebble bed reactor core analysis. In the first step, we generate equivalent cross sections from a 1-D slab spectral geometry model with the help of the equivalence theory. The equivalent cross sections generated in this way include the effect of the spectral interaction between the core and the reflector. In the second step, we perform a diffusion calculation using the equivalent cross sections generated in the first step. A simple benchmark problem derived from the PMBR-400 Reactor was introduced to verify this approach. We compared the two step solutions with the Monte Carlo (MC) solutions for the problem
Thermal characterization of large size lithium-ion pouch cell based on 1d electro-thermal model
Vertiz, G.; Oyarbide, M.; Macicior, H.; Miguel, O.; Cantero, I.; Fernandez de Arroiabe, P.; Ulacia, I.
2014-12-01
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.
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.)
Frebel, Anna; Collet, Remo; Christlieb, Norbert; Aoki, Wako
2008-01-01
We present a new abundance analysis of HE 1327-2326, the currently most iron-poor star, based on observational data obtained with VLT/UVES. We correct the 1D LTE abundances for 3D effects to provide an abundance pattern that supersedes previous works, and should be used to observationally test current models of the chemical yields of the first-generation SNe. Apart from confirming the 1D LTE abundances found in previous studies before accounting for 3D effects, we make use of a novel technique to apply the 3D-1D corrections for CNO which are a function of excitation potential and line strength for the molecular lines that comprise the observable CH, NH, and OH features. We find that the fit to the NH band at 3360 A is greatly improved due to the application of the 3D-1D corrections. This may indicate that 3D effects are actually observable in this star. We also report the first detection of several weak Ni lines. The cosmologically important element Li is still not detected; the new Li upper limit is extremel...
Momeni, Kasra; Attariani, Hamed
2014-03-14
One-dimensional (1D) zinc oxide nanostructures are the main components of nanogenerators and central to the emerging field of nanopiezotronics. Understanding the underlying physics and quantifying the electromechanical properties of these structures, the topic of this research study, play a major role in designing next-generation nanoelectromechanical devices. Here, atomistic simulations are utilized to study surface and size-scale effects on the electromechanical response of 1D ZnO nanostructures. It is shown that the mechanical and piezoelectric properties of these structures are controlled by their size, cross-sectional geometry, and loading configuration. The study reveals enhancement of the piezoelectric and elastic modulus of ZnO nanowires (NW) with diameter d > 1 nm, followed by a sudden drop for d tetragon (HT) pairs at the intersection of (21[combining macron]1[combining macron]0) and (011[combining macron]0) planes in NBs. Transition from a surface-reconstructed dominant to a surface-relaxed dominant region is demonstrated for lateral dimensions tetragonal (WZ ? BCT) and graphite-like phase (WZ ? HX) structures occurs in ZnO NWs loaded up to large strains of ?10%. PMID:24296508
Global analytical ab initio ground-state potential energy surface for the C(1D)+H2 reactive system
Zhang, Chunfang; Fu, Mingkai; Shen, Zhitao; Ma, Haitao; Bian, Wensheng
2014-06-01
A new global ab initio potential energy surface (called ZMB-a) for the 1^1A^' } state of the C(1D)+H2 reactive system has been constructed. This is based upon ab initio calculations using the internally contracted multireference configuration interaction approach with the aug-cc-pVQZ basis set, performed at about 6300 symmetry unique geometries. Accurate analytical fits are generated using many-body expansions with the permutationally invariant polynomials, except that the fit of the deep well region is taken from our previous fit. The ZMB-a surface is unique in the accurate description of the regions around conical intersections (CIs) and of van der Waals (vdW) interactions. The CIs between the 1^1A^' } and 2^1A^' } states cause two kinds of barriers on the ZMB-a surface: one is in the linear H-CH dissociation direction with a barrier height of 9.07 kcal/mol, which is much higher than those on the surfaces reported before; the other is in the C(1D) collinearly attacking H2 direction with a barrier height of 12.39 kcal/mol. The ZMB-a surface basically reproduces our ab initio calculations in the vdW interaction regions, and supports a linear C-HH vdW complex in the entrance channel, and two vdW complexes in the exit channel, at linear CH-H and HC-H geometries, respectively.
Overexpression of AtDREB1D transcription factor improves drought tolerance in soybean.
Guttikonda, Satish K; Valliyodan, Babu; Neelakandan, Anjanasree K; Tran, Lam-Son Phan; Kumar, Rajesh; Quach, Truyen N; Voothuluru, Priyamvada; Gutierrez-Gonzalez, Juan J; Aldrich, Donavan L; Pallardy, Stephen G; Sharp, Robert E; Ho, Tuan-Hua David; Nguyen, Henry T
2014-12-01
Drought is one of the major abiotic stresses that affect productivity in soybean (Glycine max L.) Several genes induced by drought stress include functional genes and regulatory transcription factors. The Arabidopsis thaliana DREB1D transcription factor driven by the constitutive and ABA-inducible promoters was introduced into soybean through Agrobacterium tumefaciens-mediated gene transfer. Several transgenic lines were generated and molecular analysis was performed to confirm transgene integration. Transgenic plants with an ABA-inducible promoter showed a 1.5- to two-fold increase of transgene expression under severe stress conditions. Under well-watered conditions, transgenic plants with constitutive and ABA-inducible promoters showed reduced total leaf area and shoot biomass compared to non-transgenic plants. No significant differences in root length or root biomass were observed between transgenic and non-transgenic plants under non-stress conditions. When subjected to gradual water deficit, transgenic plants maintained higher relative water content because the transgenic lines used water more slowly as a result of reduced total leaf area. This caused them to wilt slower than non-transgenic plants. Transgenic plants showed differential drought tolerance responses with a significantly higher survival rate compared to non-transgenic plants when subjected to comparable severe water-deficit conditions. Moreover, the transgenic plants also showed improved drought tolerance by maintaining 17-24 % greater leaf cell membrane stability compared to non-transgenic plants. The results demonstrate the feasibility of engineering soybean for enhanced drought tolerance by expressing stress-responsive genes. PMID:25192890
Evaluation of the entropy consistent euler flux on 1D and 2D test problems
Roslan, Nur Khairunnisa Hanisah; Ismail, Farzad
2012-06-01
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.
Liang, Di; Wang, Wei; Jiang, Xuechun; Yin, Shiliang
2014-07-01
A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of 1-?-d-Arabinofuranosylcytosine (ara-C), 1-?-d-Arabinofuranosyluracil (ara-U) and 1-?-d-Arabinofuranosylcytosine triphosphate (ara-CTP) in the leukemic cells for the first time. The analytes were separated on a C18 column (100mm×2.1mm, 1.8?m) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The ion-pairing reagent, NFPA, was added to the mobile phase to retain the analytes in the column. The cell homogenates sample was prepared by the simple protein precipitation. The calibration curves were linear over a concentration range of 3.45-3450.0ng/mL for ara-C, 1.12-1120.0ng/mL for ara-U and 4.13-4130.0ng/mL for ara-CTP. The intra-day and inter-day precision was less than 15% and the relative error (RE) were all within ±15%. The validated method was successfully applied to assess the disposition characteristics of ara-C and support cell pharmacokinetics after the patients with leukemia were intravenously infused with SDAC and HiDAC. The result of the present study would provide the valuable information for the ara-C therapy. PMID:24880220
Comment on supersymmetrization of N = 1 D = 10 supergravity with Lorentz Chern-Simons term
International Nuclear Information System (INIS)
We re-examine supersymmetrization of the N = 1 D = 10 supergravity with Lorentz Chern-Simons term. The supersymmetric counterparts are determined to the first order of some Noether expansion parameter, and they have one arbitrary parameter. (author)
Verification and comparison of four numerical schemes for a 1D viscoelastic blood flow model
Wang, Xiaofei; Fullana, Jose-maria; Lagre?e, Pierre-yves
2013-01-01
A reliable and fast numerical scheme is crucial for the 1D simulation of blood flow in compliant vessels. In this paper, a 1D blood flow model is incorporated with a Kelvin-Voigt viscoelastic arterial wall. This leads to a nonlinear hyperbolic-parabolic system, which is then solved with four numerical schemes, namely: MacCormack, Taylor-Galerkin, MUSCL (monotonic upwind scheme for conservation law) and local discontinuous Galerkin. The numerical schemes are tested on a singl...
Exact results for the 1D interacting Fermi gas with arbitrary polarization
Batchelor, M T; Guan, X W; Oelkers, N
2005-01-01
We investigate the 1D interacting two-component Fermi gas with arbitrary polarization. Exact results for the ground state energy, momentum distribution functions, spin velocity and charge velocity reveal subtle polarization dependent quantum effects. Additional results for the equilibrium properties of the harmonically trapped 1D Fermi gas obtained within the local density approximation indicate an interplay between the polarization dependent cloud size and the Fermi pressure.
Protective mucosal immunity mediated by epithelial CD1d and IL-10.
Olszak, Torsten; Neves, Joana F; Dowds, C Marie; Baker, Kristi; Glickman, Jonathan; Davidson, Nicholas O; Lin, Chyuan-Sheng; Jobin, Christian; Brand, Stephan; Sotlar, Karl; Wada, Koichiro; Katayama, Kazufumi; Nakajima, Atsushi; Mizuguchi, Hiroyuki; Kawasaki, Kunito; Nagata, Kazuhiro; Müller, Werner; Snapper, Scott B; Schreiber, Stefan; Kaser, Arthur; Zeissig, Sebastian; Blumberg, Richard S
2014-05-22
The mechanisms by which mucosal homeostasis is maintained are of central importance to inflammatory bowel disease. Critical to these processes is the intestinal epithelial cell (IEC), which regulates immune responses at the interface between the commensal microbiota and the host. CD1d presents self and microbial lipid antigens to natural killer T (NKT) cells, which are involved in the pathogenesis of colitis in animal models and human inflammatory bowel disease. As CD1d crosslinking on model IECs results in the production of the important regulatory cytokine interleukin (IL)-10 (ref. 9), decreased epithelial CD1d expression--as observed in inflammatory bowel disease--may contribute substantially to intestinal inflammation. Here we show in mice that whereas bone-marrow-derived CD1d signals contribute to NKT-cell-mediated intestinal inflammation, engagement of epithelial CD1d elicits protective effects through the activation of STAT3 and STAT3-dependent transcription of IL-10, heat shock protein 110 (HSP110; also known as HSP105), and CD1d itself. All of these epithelial elements are critically involved in controlling CD1d-mediated intestinal inflammation. This is demonstrated by severe NKT-cell-mediated colitis upon IEC-specific deletion of IL-10, CD1d, and its critical regulator microsomal triglyceride transfer protein (MTP), as well as deletion of HSP110 in the radioresistant compartment. Our studies thus uncover a novel pathway of IEC-dependent regulation of mucosal homeostasis and highlight a critical role of IL-10 in the intestinal epithelium, with broad implications for diseases such as inflammatory bowel disease. PMID:24717441
Measurement of one-particle correlations and momentum distributions for trapped 1D gases
Girardeau, M D
2000-01-01
van Hove's theory of scattering of probe particles by a macroscopic target is generalized so as to relate the differential cross section for atomic ejection via stimulated Raman transitions to one-particle momentum-time correlations and momentum distributions of 1D trapped gases. This method is well suited to probing the longitudinal momentum distributions of 1D gases in situ, and examples are given for bosonic and fermionic atoms.
Coherent Synchrotron Radiation and Space Charge for a 1-D Bunch on an Arbitrary Planar Orbit
International Nuclear Information System (INIS)
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
User's manual of the REFLA-1D/MODE4 reflood thermo-hydrodynamic analysis code
International Nuclear Information System (INIS)
REFLA-1D/MODE4 code has been developed by incorporating local power effect model and fuel temperature profile effect model into REFLA-1D/MODE3 code. This code can calculate the temperature transient of local rod by considering radial power profile effect in core and simulate the thermal characteristics of the nuclear fuel rod. This manual describes the outline of incorporated models, modification of the code with incorporating models and provides application information required to utilize the code. (author)
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
Energy Technology Data Exchange (ETDEWEB)
Roberts, David [Los Alamos National Laboratory; Sykes, Andrew [UNIV OF QUEENSLAND
2009-01-01
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.
Analysis of Phase Space Structure of A 1-D Discrete System Using Global and Local Symbolic Dynamics
International Nuclear Information System (INIS)
Symbolic dynamics, in which the system trajectory is represented as a string of symbols, appears as a convenient method for the analysis of properties of chaotic attractors. In this paper, we show that, using a noncanonical coding scheme based on a moving partition point, we are able to access such properties of the phase space of a dynamical system as the localisation of unstable periodic orbits and of their stable invariant manifolds. Applying different coding schemes enables us to extract different information about the phase space structure from the chaotic trajectory. A judicial choice of the method of symbolic coding allows to obtain information which may be missing in the symbolic dynamics from the generating partition. We present results for the 1-D case taking the logistic map as a numerical example. The extension to higher dimension is also discussed. The theoretical background of the methods used is also given. (author)
Slade, Angela T; Lensink, Cornelis; Falshaw, Andrew; Clark, George R; Wright, L James
2014-12-01
The monophosphinite ligands, 1D-1,2;5,6-di-O-cyclopentylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P1), 1D-1,2;5,6-di-O-isopropylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P2), 1D-1,2;5,6-di-O-cyclohexylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P3), and 1D-1,2;5,6-di-O-cyclopentylidene-3-O-ethyl-4-O-diphenylphosphino-chiro-inositol (D-P4), can be conveniently prepared from the chiral natural products 1D-pinitol or 1D-chiro-inositol. On treatment of toluene solutions of RuCl2(PPh3)3 with two mole equivalents of the ligands D-PY (Y = 1-4) the complexes RuCl2(D-P1)2 (1), RuCl2(D-P2)2 (4), RuCl2(D-P3)2 (5), or RuCl2(D-P4)2 (6), respectively, are formed. Similarly, treatment of OsCl2(PPh3)3 with D-P1 gives OsCl2(D-P1)2 (7). The single crystal X-ray structure determination of 1 reveals that each D-P1 ligand coordinates to ruthenium through phosphorus and the oxygen atom of the methoxyl group. Treatment of 1 with excess LiBr or LiI results in metathesis of the chloride ligands and RuBr2(D-P1)2 (2) or RuI2(D-P1)2 (3), respectively, are formed. Exposure of a solution of 1 to carbon monoxide results in the very rapid formation of RuCl2(CO)2(D-P1)2 (8), thereby demonstrating the ease with which the oxygen donors are displaced from the metal and hence the hemilabile nature of the two bidentate D-P1 ligands in 1. Preliminary studies indicate that 1-7 act as catalysts for the asymmetric hydrogenation reactions of acetophenone and 3-quinuclidinone to give the corresponding alcohols in generally high conversions but low enantiomeric excesses. PMID:25315464
Barker, H. W.; Stephens, G. L.; Partain, P. T.; Bergman, J. W.; Bonnel, B.; Campana, K.; Clothiaux, E. E.; Clough, S.; Cusack, S.; Delamere, J.; Edwards, J.; Evans, K. F.; Fouquart, Y.; Freidenreich, S.; Galin, V.; Hou, Y.; Kato, S.; Li, J.; Mlawer, E.; Morcrette, J.-J.; O'Hirok, W.; Räisänen, P.; Ramaswamy, V.; Ritter, B.; Rozanov, E.; Schlesinger, M.; Shibata, K.; Sporyshev, P.; Sun, Z.; Wendisch, M.; Wood, N.; Yang, F.
2003-08-01
The primary purpose of this study is to assess the performance of 1D solar radiative transfer codes that are used currently both for research and in weather and climate models. Emphasis is on interpretation and handling of unresolved clouds. Answers are sought to the following questions: (i) How well do 1D solar codes interpret and handle columns of information pertaining to partly cloudy atmospheres? (ii) Regardless of the adequacy of their assumptions about unresolved clouds, do 1D solar codes perform as intended?One clear-sky and two plane-parallel, homogeneous (PPH) overcast cloud cases serve to elucidate 1D model differences due to varying treatments of gaseous transmittances, cloud optical properties, and basic radiative transfer. The remaining four cases involve 3D distributions of cloud water and water vapor as simulated by cloud-resolving models. Results for 25 1D codes, which included two line-by-line (LBL) models (clear and overcast only) and four 3D Monte Carlo (MC) photon transport algorithms, were submitted by 22 groups. Benchmark, domain-averaged irradiance profiles were computed by the MC codes. For the clear and overcast cases, all MC estimates of top-of-atmosphere albedo, atmospheric absorptance, and surface absorptance agree with one of the LBL codes to within ±2%. Most 1D codes underestimate atmospheric absorptance by typically 15-25 W m-2 at overhead sun for the standard tropical atmosphere regardless of clouds.Depending on assumptions about unresolved clouds, the 1D codes were partitioned into four genres: (i) horizontal variability, (ii) exact overlap of PPH clouds, (iii) maximum/random overlap of PPH clouds, and (iv) random overlap of PPH clouds. A single MC code was used to establish conditional benchmarks applicable to each genre, and all MC codes were used to establish the full 3D benchmarks. There is a tendency for 1D codes to cluster near their respective conditional benchmarks, though intragenre variances typically exceed those for the clear and overcast cases. The majority of 1D codes fall into the extreme category of maximum/random overlap of PPH clouds and thus generally disagree with full 3D benchmark values. Given the fairly limited scope of these tests and the inability of any one code to perform extremely well for all cases begs the question that a paradigm shift is due for modeling 1D solar fluxes for cloudy atmospheres.
Salmanowicz, Boles?aw P; Langner, Monika; Wi?niewska, Halina; Apolinarska, Barbara; Kwiatek, Micha?; B?aszczyk, Lidia
2013-01-01
Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW) glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number) of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax), and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement. PMID:23896593
Directory of Open Access Journals (Sweden)
Lidia B?aszczyk
2013-07-01
Full Text Available Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8. Genomic in situ hybridization (GISH and fluorescence in situ hybridization (FISH confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax, and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.
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
Final HERMES results on the proton, deuteron and neutron structure function g1 are presented in the kinematic range 0.0021
Benchmarks and models for 1-D radiation transport in stochastic participating media
Energy Technology Data Exchange (ETDEWEB)
Miller, D S
2000-08-21
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.
Magnetohydrodynamic generators
International Nuclear Information System (INIS)
The basic theoretical and practical information is presented on magnetohydrodynamic generators. Fundamental information is given on the thermodynamic cycles of heat engines, on low-temperature plasma used in magnetohydrodynamic generators, on plasma flow in a magnetic field, and on three basic MHD generator groups, i.e., open cycle generators, closed cycle generators with non-equilibrium plasma, and liquid metal generators which may directly be used for the production of alternating current. (Ha)
International Nuclear Information System (INIS)
Recently developed analytic methods, which reduce the Glauber amplitude for charged-particle--neutral-atom collisions to a one-dimensional integral representation involving modified Lommel functions, are used to evaluate the cross sections for the direct excitation of 3 1D and 4 1D states of helium by electron impact with incident energies from 40 to 1000 eV. It is shown that the Glauber amplitudes can be written in terms of three generating functions: One of these has already been derived by Thomas and Chan; the detailed reduction of the other two is given in this paper. Comparison is made with the Born, Ochkur, and Woollings-McDowell approximations. The polarization fraction of the 6678-A helium line emitted in e-+He collisions is also calculated in the Glauber approximation. The agreement between theory and experiment is less than satisfactory in the entire energy region
VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm
Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Santos, Fernando Acácio Monteiro dos; Almeida, Emerson Rodrigo
2015-01-01
Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Paraná sedimentary basin (Bebedouro and Pirassununga cities), both located in São Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies.
PIH1D1 interacts with mTOR complex 1 and enhances ribosome RNA transcription.
Kamano, Yuya; Saeki, Makio; Egusa, Hiroshi; Kakihara, Yoshito; Houry, Walid A; Yatani, Hirofumi; Kamisaki, Yoshinori
2013-10-11
PIH1D1 is the defining component of the R2TP complex. Recently, R2TP has been reported to stabilize mTOR (mammalian target of rapamycin), an important regulator of cell growth and protein synthesis. Two complexes of mTOR, mTORC1 and mTORC2, have been identified. We demonstrate that immunoprecipitation (IP) of PIH1D1 results in the co-IP of Raptor (mTORC1 specific), but not Rictor (mTORC2 specific), and that knockdown of PIH1D1 decreases mTORC1 assembly, S6 kinase phosphorylation (indicator of mTORC1 activity), and rRNA transcription without affecting mTORC2 in human breast cancer MCF-7 cells. In addition, we provide evidence that PIH1D1 is overexpressed in various breast cancer cell lines. These findings collectively suggest that PIH1D1 may have an important role in mTORC1 regulation in breast cancers. PMID:24036451
U-duality twists and possible phase transitions in 2+1 D supergravity
Ganor, O J
1999-01-01
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.
Development of 1-D carbon composites for plasma-facing components
International Nuclear Information System (INIS)
Carbon-based materials continue to be proposed and utilized as plasma-facing surfaces in fusion devices because of their low atomic number and superior high temperature thermal properties. This study presents results of a carbon-carbon composite development program for high heat flux surfaces using one-dimensional (1-D), high thermal conductivity materials. Thermal conductivity testing of six 1-D composites was accomplished, along with coefficient of thermal expansion (CTE) tests. Results indicate progress toward achieving composites with very high conductivity, approaching pyrolytic graphite values. Several 1-D composites have room temperature thermal conductivities which exceed 500 W/m K in the parallel-to-fiber direction. Perpendicular-to-fiber direction conductivity values were typically more that an order of magnitude lower. Experimental CTE data show values up to 10x10-6/ C perpendicular to fibers and nearly zero values in the fiber direction. Mechanical property testing will be included in future efforts. ((orig.))
3+1D Massless Weyl spinors from bosonic scalar-tensor duality
Amoretti, Andrea; Caruso, Giacomo; Maggiore, Nicola; Magnoli, Nicodemo
2013-01-01
We consider the fermionization of a bosonic free theory characterized by the 3+1D scalar - tensor duality. This duality can be interpreted as the dimensional reduction, via a planar boundary, of the 4+1D topological BF theory. In this model, adopting the Sommerfield tomographic representation of quantized bosonic fields, we explicitly build a fermionic operator and its associated Klein factor such that it satisfies the correct anticommutation relations. Interestingly, we demonstrate that this operator satisfies the massless Dirac equation and that it can be identified with a 3+1D Weyl spinor. Finally, as an explicit example, we write the integrated charge density in terms of the tomographic transformed bosonic degrees of freedom.
A comparison of 1D and 2D LSTM architectures for the recognition of handwritten Arabic
Yousefi, Mohammad Reza; Soheili, Mohammad Reza; Breuel, Thomas M.; Stricker, Didier
2015-01-01
In this paper, we present an Arabic handwriting recognition method based on recurrent neural network. We use the Long Short Term Memory (LSTM) architecture, that have proven successful in different printed and handwritten OCR tasks. Applications of LSTM for handwriting recognition employ the two-dimensional architecture to deal with the variations in both vertical and horizontal axis. However, we show that using a simple pre-processing step that normalizes the position and baseline of letters, we can make use of 1D LSTM, which is faster in learning and convergence, and yet achieve superior performance. In a series of experiments on IFN/ENIT database for Arabic handwriting recognition, we demonstrate that our proposed pipeline can outperform 2D LSTM networks. Furthermore, we provide comparisons with 1D LSTM networks trained with manually crafted features to show that the automatically learned features in a globally trained 1D LSTM network with our normalization step can even outperform such systems.
Microstates of D1-D5(-P) black holes as interacting D-branes
Morita, Takeshi
2014-01-01
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.
[Investigation of transmission spectral of 1-D photonic crystal with LC].
Liu, Yong-jun; Lian, Jia; Hu, Li-fa; Lu, Xing-hai; Xuan, Li
2010-08-01
One-dimensional (1-D) photonic crystals(PCs)with liquid crystals (LCs) are promising in various applications such as filters, low-threshold lasers, optical switch. In the present paper, the authors investigated the transmission spectrum of 1-D PCs with LCs for defect layer at different voltages ranging from 0 to 10 V. The tunable spectral range was about 50 nm, FWHM of the transmission peak was 18 nm and the band gap was nearly 400 nm. Furthermore, we presented a kind of polarization insensitive LC photonic crystal, and designed a 1-D LC photonic crystal device that has double LC layers with zero twisted angle. Double LC layers have a function of compensation for both polarization components of incident light, which makes the original two transmission peaks in the band gap to incorporate to one, and enhances the light intensity and filter performance. PMID:20939299
Universal nature of collective plasmonic excitations in finite 1-D carbon-based nanostructures
Polizzi, Eric
2015-01-01
Tomonaga-Luttinger (T-L) theory predicts collective plasmon resonances in 1-D nanostructure conductors of finite length, that vary roughly in inverse proportion to the length of the structure. Yet, such resonances have not been clearly identified in experiments so far. Here we provide evidence of the T-L plasmon resonances using first-principle computational real-time spectroscopy studies of representative finite 1-D carbon-based nanostructures ranging from atom and benzene-like chain structures to short carbon nanotubes. Our all-electron Time-Dependent Density-Functional Theory (TDDFT) real-time simulation framework is capable to accurately capture the relevant nanoscopic effects including correct frequencies for known optical transitions, and various collective plasmon excitations. The presence of 1-D T-L plasmons is universally predicted by the various numerical experiments, which also demonstrate a phenomenon of resonance splitting. Extending these simulations to longer structures will allow the accurate ...
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
Modelling turbulent vertical mixing sensitivity using a 1-D version of NEMO
Directory of Open Access Journals (Sweden)
G. Reffray
2014-08-01
Full Text Available Through two numerical experiments, a 1-D vertical model called NEMO1D was used to investigate physical and numerical turbulent-mixing behaviour. The results show that all the turbulent closures tested (k + l from Blanke and Delecluse, 1993 and two equation models: Generic Lengh Scale closures from Umlauf and Burchard, 2003 are able to correctly reproduce the classical test of Kato and Phillips (1969 under favourable numerical conditions while some solutions may diverge depending on the degradation of the spatial and time discretization. The performances of turbulence models were then compared with data measured over a one-year period (mid-2010 to mid-2011 at the PAPA station, located in the North Pacific Ocean. The modelled temperature and salinity were in good agreement with the observations, with a maximum temperature error between ?2 and 2 °C during the stratified period (June to October. However the results also depend on the numerical conditions. The vertical RMSE varied, for different turbulent closures, from 0.1 to 0.3 °C during the stratified period and from 0.03 to 0.15 °C during the homogeneous period. This 1-D configuration at the PAPA station (called PAPA1D is now available in NEMO as a reference configuration including the input files and atmospheric forcing set described in this paper. Thus, all the results described can be recovered by downloading and launching PAPA1D. The configuration is described on the NEMO site (http://www.nemo-ocean.eu/Using-NEMO/Configurations/C1D_PAPA. This package is a good starting point for further investigation of vertical processes.
Heat Conduction and Long-Range Spatial Correlation in 1D Models
Zhou, X; Zhou, Xin; Iwamoto, Mitsumasa
2002-01-01
Heat conduction in a 1D model is studied. The model can be analytically treated, based on the mesoscopic electronic transport theory (METT). The normal heat conduction is correspondent with the incoherent transport in METT. By defining a `phase' correlation between particles at the two ends of the 1D chain, we find that the randomization of scatterers implies the absence of the correlation, which it indicates a normal thermal conductivity. For comparing, we also numerically simulate the energy transport in the model. The results are help for understanding some previous researches about the condition to get the normal heat conduction.
Construction and Analysis of Lattice Boltzmann Methods Applied to a 1D Convection-Diffusion Equation
Dellacherie, Ste?phane
2012-01-01
We construct and we analyze two LBM schemes build on the D1Q2 lattice to solve the 1D (linear) convection-diffusion equation. We obtain these LBM schemes by showing that the 1D convection-diffusion equation is the fluid limit of a discrete velocity kinetic system. Then, we show in the periodic case that these LBM schemes are equivalent to a finite difference type scheme named LFCCDF scheme. This allows us, firstly, to prove the convergence in L? of these schemes, and to obtain discrete maxi...
Dopamine D1-D2 receptor heteromer signaling pathway in the brain: emerging physiological relevance
Directory of Open Access Journals (Sweden)
Hasbi Ahmed
2011-06-01
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.
Superdescendants of the D1D5 CFT and their dual 3-charge geometries
Giusto, Stefanodipartimento Di Fisica Ed Astronomia “galileo Galilei”; Russo, Rodolfo
2013-01-01
We describe how to obtain the gravity duals of semiclassical states in the D1-D5 CFT that are superdescendants of a class of RR ground states. On the gravity side, the configurations we construct are regular and asymptotically reproduce the 3-charge D1-D5-P black hole compactified on $S^1\\times T^4$. The geometries depend trivially on the $T^4$ directions but non-trivially on the remaining 6D space. In the decoupling limit, they reduce to asymptotically AdS$_3 \\times S^3 \\ti...
Quasi-1D Modeling of Polymer Melt Die Swell in Short Dies
Jeong, Jae-hyeuk; Leonov, Arkady I.
2003-01-01
This paper describes the isothermal die swell using our recent quasi-1D model for fast (high Deborah number) contraction flows of polymers melts. Because the model analyzes the flow in several flow regions as one continuous process, it makes possible to evaluate the die swell as a qusi-1D extrudate flow in dies of various lengths. Using the asymptotic matching condition for the change in flow type at the die exit allowed us to find the swelling profile for extrudate along th...
Propagating mode in the photonic gap of 1D resonant Bragg reflector
Energy Technology Data Exchange (ETDEWEB)
Cho, Kikuo; Hirai, Takahiko; Ikawa, Tomoe
2002-12-15
Concerning '1D resonant photonic crystals', i.e., 1D periodic arrays of resonant layers with a spacing satisfying the Bragg condition for resonant light, recent topics are summarized together with additional new findings. The central points are about (1) the recent theoretical finding of a new branch in the middle of photonic gap, (2) an approach-dependent controversy about its existence, (3) its consequence as sharp dips in reflectance spectrum and the corresponding internal field patters, indicating its propagating mode character, (4) the comparison between macroscopic and microscopic treatment of resonance effect, and (5) corrected transfer matrix method and its analytical equivalence with nonlocal response theory.
Single File Diffusion enhancement in a fluctuating modulated 1D channel
Coupier, G; Guthmann, C; Coupier, Gwennou; Jean, Michel Saint; Guthmann, Claudine
2006-01-01
We show that the diffusion of a single file of particles moving in a fluctuating modulated 1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favored by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by adapted patterns of pinning sites.
The (2 + 1)-d U(1) quantum link model masquerading as deconfined criticality
International Nuclear Information System (INIS)
The (2 + 1)-d U(1) quantum link model is a gauge theory, amenable to quantum simulation, with a spontaneously broken SO(2) symmetry emerging at a quantum phase transition. Its low-energy physics is described by a (2 + 1)-d RP(1) effective field theory, perturbed by an SO(2) breaking operator, which prevents the interpretation of the emergent pseudo-Goldstone boson as a dual photon. At the quantum phase transition, the model mimics some features of deconfined quantum criticality, but remains linearly confining. Deconfinement only sets in at high temperature. (paper)
1D/3D Coupling Calculation Analysis on Bus Cooling System
Directory of Open Access Journals (Sweden)
Kai Shen
2014-12-01
Full Text Available Compared with front engine vehicle, the windward side’s flow field in cooling model of rear engine bus is complicated and it can’t be calculated by means of 1D model. For this problem, this paper has used Star-CCM to build a 3D simulation model of cooling system, engine compartment and complete vehicle. Then, it had a 1D/3D coupling calculation on cooling system with Kuli software. It could be helpful in the optimization design of the flow field of rear engine compartment and optimization match of cooling system.
Quantized 1D- and 2D optical molasses: Laser cooling and spectrum of resonance fluorescene
International Nuclear Information System (INIS)
We present results for laser cooling of optical molasses and the spectrum of resonance fluorescene based on a fully quantum mechanical treatment of the atomic center-of-mass motion for 1D and 2D laser configurations. Our calculations based on recently developed wave function simulations of the quantum master equation for laser cooling
1D Cahn-Hilliard equation: Ostwald ripening and application to modulated phase systems
Villain-guillot, Simon
2008-01-01
Using an approximate analytical solution of the Cahn-Hilliard equation describing the coalescence during a first order phase transition, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, we compute the thermodynamically stable period of a 1D modulated phase pattern.
Nonlinear Control of Absorption in Graphene-based 1D Photonic Crystal
Vincenti, M. A.; Ceglia, D.; Grande, M.; D Orazio, A.; Scalora, M.
2013-01-01
Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic crystal with a monolayer graphene defect. Thanks to the large third order nonlinearity of graphene and field localization in the defect layer we demonstrate the possibility to achieve controllable, saturable absorption for the pump frequency.
Fresnel Lenses fabricated by femtosecond laser micromachining on Polymer 1D Photonic Crystal
Directory of Open Access Journals (Sweden)
Guduru Surya S.K.
2013-11-01
Full Text Available We report the fabrication of micro Fresnel lenses by femtosecond laser surface ablation on polymer 1D photonic crystals. This device is designed to focus the transmitted wavelength of the photonic crystal and filter the wavelengths corresponding to the photonic band gap region. Integration of such devices in a wavelength selective light harvesting and filtering microchip can be achieved.
Dilepton production in high energy heavy ion collisions with 3+1D relativistic viscous hydrodynamics
Vujanovic, G; Schenke, B; Jeon, S; Rapp, R; Gale, C
2012-01-01
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.
Dilepton production in high energy heavy ion collisions with 3+1D relativistic viscous hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Vujanovic, G.; Young, C. [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Schenke, B. [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Jeon, S. [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Rapp, R. [Cyclotron Institute and Dept. of Physics and Astronomy, Texas A and M University, College Station, TX 77843-3366 (United States); Gale, C. [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada)
2013-05-02
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.
Gargiulo, Lucia; Papaioannou, Maria; Sica, Michela; Talini, Giulia; Chaidos, Aristeidis; Richichi, Barbara; Nikolaev, Andrei V; Nativi, Cristina; Layton, Mark; de la Fuente, Josu; Roberts, Irene; Luzzatto, Lucio; Notaro, Rosario; Karadimitris, Anastasios
2013-04-01
The mechanism of bone marrow failure (BMF) in paroxysmal nocturnal hemoglobinuria (PNH) is not yet known. Because in PNH the biosynthesis of the glycolipid molecule glycosylphosphatidylinositol (GPI) is disrupted in hematopoietic stem and progenitor cells by a somatic mutation in the PIG-A gene, BMF might result from an autoimmune attack, whereby T cells target GPI in normal cells, whereas PIG-A mutant GPI-negative cells are spared. In a deliberate test of this hypothesis, we have demonstrated in PNH patients the presence of CD8(+) T cells reactive against antigen-presenting cells (APCs) loaded with GPI. These T cells were significantly more abundant in PNH patients than in healthy controls; their reactivity depended on CD1d expression and they increased upon coculture with CD1d-expressing, GPI-positive APCs. In GPI-specific T cells captured by CD1d dimer technology, we identified, through global T-cell receptor ? (TCR?) analysis, an invariant TCRV?21 sequence, which was then found at frequencies higher than background in the TCR repertoire of 6 of 11 PNH patients. Thus, a novel, autoreactive, CD1d-restricted, GPI-specific T-cell population, enriched in an invariant TCR? chain, is expanded in PNH patients and may be responsible for BMF in PNH. PMID:23372165
Multiple channel dynamics in the O(1D) reaction with alkanes.
Yang, Xueming
2006-01-14
In this article, we briefly review the recent experimental studies of the multiple channel dynamics of the O((1)D) reaction with alkane molecules using the significantly improved universal crossed molecular beam technique. In these reactions, the dominant reaction mechanism is found to be an O atom insertion into the C-H bond, while a direct abstraction mechanism is also present in the OH formation channel. While the reaction mechanism is similar for all of these reactions, the product channels are quite different because of the significantly different energetics of these reaction channels. In the O((1)D) reaction with methane, OH formation is the dominant process while H atom formation is also a significant process. In the O((1)D) reaction with ethane, however, the CH(3) + CH(2)OH is the most important process, OH formation is still significant and H atom formation is of minor importance. A new type of O atom insertion mechanism (insertion into a C-C bond) is also inferred from the O((1)D) reaction with cyclopropane. Through these comprehensive studies, complete dynamical pictures of many multiple channel chemical reactions could be obtained. Such detailed studies could provide a unique bridge between dynamics and kinetics research. PMID:16482261
Clifford algebras and the minimal representations of the 1D N-extended supersymmetry algebra
Energy Technology Data Exchange (ETDEWEB)
Toppan, Francesco [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: toppan@cbpf.br
2008-07-01
The Atiyah-Bott-Shapiro classification of the irreducible Clifford algebra is used to derive general properties of the minimal representations of the 1D N-Extended Supersymmetry algebra (the Z{sub 2}-graded symmetry algebra of the Supersymmetric Quantum Mechanics) linearly realized on a finite number of fields depending on a real parameter t, the time. (author)
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)
Boltzmann equation in 1D-spherical and cylindrical geometry. Specifications of the ORPHEE code
International Nuclear Information System (INIS)
Specifications of ORPHEE (a neutronic time-independent code for 1D-spherical or cylindrical-geometry) are given. The various forms of Boltzmann's equation, with respect to the kind of symmetry are presented. The development of the anisotropic source is studied and then it is shown how to build finite difference schemes in order to get a good approximation of this equation
A fast sonochemical method to prepare 1D and 3D nanostructures of bismuth sulfide
Scientific Electronic Library Online (English)
Paulo R. R., Mesquita; Jorge S., Almeida; Leonardo S. G., Teixeira; Antônio F. da, Silva; Luciana A., Silva.
2013-02-01
Full Text Available 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.
3D Versus 1D Radiative Transfer Modeling of Planetary Nebulae
Pantoja, Blake M.; Ladjal, Djazia
2015-01-01
Planetary nebulae are the products of the fast stellar wind from the end of the AGB star phase. To date, there are many one-dimensional radiative transfer codes, and a few fully 3D codes that can model the ionization of the planetary nebulae. Some limitations on 1D codes are that they can only make spherical or parallel plane models, while 3D codes take much computing power and memory to run. A pseudo-3D code such as pyCloudy can model a planetary nebula in 3D by making multiple runs of a 1D code such as Cloudy in different angles from the center of the nebula. We compared the 1D models with pseudo-3D models to determine if the 1D models give good approximations for the observed parameters of the planetary nebulae. We find that one-dimensional codes can actually give good estimates for electron temperature and density in a bipolar planetary nebula.
1D Cahn-Hilliard equation: Ostwald ripening and modulated phase systems
Villain-guillot, Simon
2007-01-01
Using an approximate analytical solution of the Cahn-Hilliard equation describing the coalescence during a first order phase transition, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, we compute the thermodynamically stable period of a 1D modulated phase pattern.
Critical Temperature of the Deconfining Phase Transition in (2+1)d Georgi-Glashow Model
Kovchegov, Yu V; Kovchegov, Yuri V.
2003-01-01
We find the temperature of the phase transition in the (2+1)d Georgi-Glashow model. The critical temperature is shown to depend on the gauge coupling and on the ratio of Higgs and gauge boson masses. In the BPS limit of light Higgs the previous result by Dunne, Kogan, Kovner, and Tekin is reproduced.
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)
Systematics of the single-particle properties of the 1d2s shell nuclei
International Nuclear Information System (INIS)
Experimental data on pickup and stripping reactions have been used to investigate single-particle properties of the most stable nuclei of the 1d2s shell. Populations of proton subshells and single-particle energies of the nuclear hamiltonian are obtained. (orig.)
CAMK1D amplification implicated in epithelial-mesenchymal transition in basal-like breast cancer.
Bergamaschi, Anna; Kim, Young H; Kwei, Kevin A; La Choi, Yoon; Bocanegra, Melanie; Langerød, Anita; Han, Wonshik; Noh, Dong-Young; Huntsman, David G; Jeffrey, Stefanie S; Børresen-Dale, Anne-Lise; Pollack, Jonathan R
2008-12-01
Breast cancer exhibits clinical and molecular heterogeneity, where expression profiling studies have identified five major molecular subtypes. The basal-like subtype, expressing basal epithelial markers and negative for estrogen receptor (ER), progesterone receptor (PR) and HER2, is associated with higher overall levels of DNA copy number alteration (CNA), specific CNAs (like gain on chromosome 10p), and poor prognosis. Discovering the molecular genetic basis of tumor subtypes may provide new opportunities for therapy. To identify the driver oncogene on 10p associated with basal-like tumors, we analyzed genomic profiles of 172 breast carcinomas. The smallest shared region of gain spanned just seven genes at 10p13, including calcium/calmodulin-dependent protein kinase ID (CAMK1D), functioning in intracellular signaling but not previously linked to cancer. By microarray, CAMK1D was overexpressed when amplified, and by immunohistochemistry exhibited elevated expression in invasive carcinomas compared to carcinoma in situ. Engineered overexpression of CAMK1D in non-tumorigenic breast epithelial cells led to increased cell proliferation, and molecular and phenotypic alterations indicative of epithelial-mesenchymal transition (EMT), including loss of cell-cell adhesions and increased cell migration and invasion. Our findings identify CAMK1D as a novel amplified oncogene linked to EMT in breast cancer, and as a potential therapeutic target with particular relevance to clinically unfavorable basal-like tumors. PMID:19383354
Interaction of Dual N=1, D=10 Supergravity with Yang-Mills Matter Multiplet
Saulina, N. A.; Terentiev, M. V.; Zyablyuk, K. N.
1994-01-01
The lagrangian of the N=1, D=10 dual supergravity interacting with the Yang-Mills matter multiplet is constructed starting immediately from the equations of motion obtained from the Bianchi Identities in the superspace approach. The difference is established in comparison with the Gates-Nishino lagrangian at the fourth order level in fermionic fields.
Scientific Electronic Library Online (English)
W., Wang; H., Zhu; H., Zhang; L., Zhang; Q., Ding; H., Jiang.
1044-10-01
Full Text Available 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.
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
Energy Technology Data Exchange (ETDEWEB)
Zhang, Damao; Wang, Zhien; Heymsfield, Andrew J.; Fan, Jiwen; Luo, Tao
2014-10-01
Measurement of ice number concentration in clouds is important but still challenging. Stratiform mixed-phase clouds (SMCs) provide a simple scenario for retrieving ice number concentration from remote sensing measurements. The simple ice generation and growth pattern in SMCs offers opportunities to use cloud radar reflectivity (Ze) measurements and other cloud properties to infer ice number concentration quantitatively. To understand the strong temperature dependency of ice habit and growth rate quantitatively, we develop a 1-D ice growth model to calculate the ice diffusional growth along its falling trajectory in SMCs. The radar reflectivity and fall velocity profiles of ice crystals calculated from the 1-D ice growth model are evaluated with the Atmospheric Radiation Measurements (ARM) Climate Research Facility (ACRF) ground-based high vertical resolution radar measurements. Combining Ze measurements and 1-D ice growth model simulations, we develop a method to retrieve the ice number concentrations in SMCs at given cloud top temperature (CTT) and liquid water path (LWP). The retrieved ice concentrations in SMCs are evaluated with in situ measurements and with a three-dimensional cloud-resolving model simulation with a bin microphysical scheme. These comparisons show that the retrieved ice number concentrations are within an uncertainty of a factor of 2, statistically.
Desrosiers, Jacques
2006-01-01
This book provides a survey overview of the state-of-the-art in integer programming column generation and its many applications, featuring chapters written by leading experts in the various methodological and application areas of Column Generation.
Combined crossed beam and theoretical studies of the C(1D) + CH4 reaction
Leonori, Francesca; Skouteris, Dimitrios; Petrucci, Raffaele; Casavecchia, Piergiorgio; Rosi, Marzio; Balucani, Nadia
2013-01-01
The reaction involving atomic carbon in its first electronically excited state 1D and methane has been investigated in crossed molecular beam experiments at a collision energy of 25.3 kJ mol-1. Electronic structure calculations of the underlying potential energy surface (PES) and Rice-Ramsperger-Kassel-Marcus (RRKM) estimates of rates and branching ratios have been performed to assist the interpretation of the experimental results. The reaction proceeds via insertion of C(1D) into one of the C-H bonds of methane leading to the formation of the intermediate HCCH3 (methylcarbene or ethylidene), which either decomposes directly into the products C2H3 + H or C2H2 + H2 or isomerizes to the more stable ethylene, which in turn dissociates into C2H3 + H or H2CC + H2. The experimental results indicate that the H-displacement and H2-elimination channels are of equal importance and that for both channels the reaction mechanism is controlled by the presence of a bound intermediate, the lifetime of which is comparable to its rotational period. On the contrary, RRKM estimates predict a very short lifetime for the insertion intermediate and the dominance of the H-displacement channel. It is concluded that the reaction C(1D) + CH4 cannot be described statistically and a dynamical treatment is necessary to understand its mechanism. Possibly, nonadiabatic effects are responsible for the discrepancies, as triplet and singlet PES of methylcarbene cross each other and intersystem crossing is possible. Similarities with the photodissociation of ethylene and with the related reactions N(2D) + CH4, O(1D) + CH4 and S(1D) + CH4 are also commented on.
Chalothorn, Dan; McCune, Dan F; Edelmann, Stephanie E; Tobita, Kimimasa; Keller, Bradley B; Lasley, Robert D; Perez, Dianne M; Tanoue, Akito; Tsujimoto, Gozoh; Post, Ginell R; Piascik, Michael T
2003-06-01
The regulation of cardiac and vascular function by the alpha 1B- and alpha 1D-adrenoceptors (ARs) has been assessed in two lines of transgenic mice, one over-expressing a constitutively active alpha 1B-AR mutation (alpha 1B-ARC128F) and the other an alpha 1D-AR knockout line. The advantage of using mice expressing a constitutively active alpha 1B-AR is that the receptor is tonically active, thus avoiding the use of nonselective agonists that can activate all subtypes. In hearts from animals expressing alpha 1B-ARC128F, the activities of the mitogen-activated protein kinases, extracellular signal-regulated kinase, and c-Jun N-terminal kinase were significantly elevated compared with nontransgenic control animals. Mice over-expressing the alpha 1B-ARC128F had echocardiographic evidence of contractile dysfunction and increases in chamber dimensions. In isolated-perfused hearts or left ventricular slices from alpha 1B-ARC128F-expressing animals, the ability of isoproterenol to increase contractile force or increase cAMP levels was significantly decreased. In contrast to the prominent effects on the heart, constitutive activation of the alpha 1B-AR had little effect on the ability of phenylephrine to induce vascular smooth muscle contraction in the isolated aorta. The ability of phenylephrine to stimulate coronary vasoconstriction was diminished in alpha 1D-AR knockout mice. In alpha 1D-AR knockout animals, no negative effects on cardiac contractile function were noted. These results show that the alpha1-ARs regulate distinctly different physiologic processes. The alpha 1B-AR appears to be involved in the regulation of cardiac growth and contractile function, whereas the alpha 1D-AR is coupled to smooth muscle contraction and the regulation of systemic arterial blood pressure. PMID:12649302
The D1-D2 region of the large subunit ribosomal DNA as barcode for ciliates.
Stoeck, T; Przybos, E; Dunthorn, M
2014-05-01
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 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
International Nuclear Information System (INIS)
The object of the present invention is the provision of an improved vapor generator for use with a gas-cooled reactor in an electrical power generating facility. The vapor generator is particularly suited for use in a substantially cylindrical cavity in a pressure vessel and the length of tubing used in unheated sections and in expansion zones is minimized. (UK)
International Nuclear Information System (INIS)
The patent describes an isotope generator incorporating the possibility of stopping elution before the elution vessel is completely full. Sterile ventilation of the whole system can then occur, including of both generator reservoir and elution vessel. A sterile, and therefore pharmaceutically acceptable, elution fluid is thus obtained and the interior of the generator is not polluted with non-sterile air. (T.P.)
Hart, Joanne B; Kröger, Lars; Falshaw, Andrew; Falshaw, Ruth; Farkas, Erzsébet; Thiem, Joachim; Win, Anna L
2004-08-01
The products from the enzymatic beta-D-galactopyranosylation of 1D-chiro-inositol, 1D-pinitol, 1D-3-O-allyl-4-O-methyl-chiro-inositol, 1D-3,4-di-O-methyl-chiro-inositol, 1L-chiro-inositol and myo-inositol in combined yields ranging from 46% to 64% have been obtained using the beta-galactosidase isolated from an anaerobic extreme thermophile, Thermoanaerobacter sp. strain TP6-B1 and p-nitrophenyl beta-D-galactopyranoside as the donor. Analysis of the products from these reactions reveals information about the acceptor preferences of the enzyme. PMID:15261579
Arroyo-Torres, B.; Wittkowski, M.; Chiavassa, A.; Scholz, M.; Freytag, B.; Marcaide, J. M.; Hauschildt, P. H.; Wood, P. R.; Abellan, F. J.
2015-03-01
Aims: This research has two main goals. First, we present the atmospheric structure and the fundamental parameters of three red supergiants (RSGs), increasing the sample of RSGs observed by near-infrared spectro-interferometry. Additionally, we test possible mechanisms that may explain the large observed atmospheric extensions of RSGs. Methods: We carried out spectro-interferometric observations of the RSGs V602 Car, HD 95687, and HD 183589 in the near-infrared K-band (1.92-2.47 ?m) with the VLTI/AMBER instrument at medium spectral resolution (R ~ 1500). To categorize and comprehend the extended atmospheres, we compared our observational results to predictions by available hydrostatic PHOENIX, available 3D convection, and new 1D self-excited pulsation models of RSGs. Results: Our near-infrared flux spectra of V602 Car, HD 95687, and HD 183589 are well reproduced by the PHOENIX model atmospheres. The continuum visibility values are consistent with a limb-darkened disk as predicted by the PHOENIX models, allowing us to determine the angular diameter and the fundamental parameters of our sources. Nonetheless, in the case of V602 Car and HD 95686, the PHOENIX model visibilities do not predict the large observed extensions of molecular layers, most remarkably in the CO bands. Likewise, the 3D convection models and the 1D pulsation models with typical parameters of RSGs lead to compact atmospheric structures as well, which are similar to the structure of the hydrostatic PHOENIX models. They can also not explain the observed decreases in the visibilities and thus the large atmospheric molecular extensions. The full sample of our RSGs indicates increasing observed atmospheric extensions with increasing luminosity and decreasing surface gravity, and no correlation with effective temperature or variability amplitude. Conclusions: The location of our RSG sources in the Hertzsprung-Russell diagram is confirmed to be consistent with the red limits of recent evolutionary tracks. The observed extensions of the atmospheric layers of our sample of RSGs are comparable to those of Mira stars. This phenomenon is not predicted by any of the considered model atmospheres including available 3D convection and new 1D pulsation models of RSGs. This confirms that neither convection nor pulsation alone can levitate the molecular atmospheres of RSGs. Our observed correlation of atmospheric extension with luminosity supports a scenario of radiative acceleration on Doppler-shifted molecular lines. Based on observations made with the VLT Interferometer (VLTI) at Paranal Observatory under programme ID 091.D-0275.Figures 2-6 are available in electronic form at http://www.aanda.org
Zhao, Xueying; Zhang, Yuanyuan; Leander, Michelle; Li, Lingyun; Wang, Guoshen; Emmett, Nerimiah
2014-01-01
Alpha(1D)-adrenergic receptor (?(1D)-AR) plays important roles in regulating physiological and pathological responses mediated by catecholamines, particularly in the cardiovascular and urinary systems. The present study was designed to investigate the expression profile of ?(1D)-AR in the diabetic kidneys and its modulation by activation of peroxisome proliferator-activated receptors (PPARs). 12-week-old Zucker lean (ZL) and Zucker diabetic fatty (ZD) rats were treated with fenofibrate or rosiglitazone for 8-10 weeks. Gene microarray, real-time PCR, and confocal immunofluorescence microscopy were performed to assess mRNA and protein expression of ?(1D)-AR in rat kidney tissue. Using microarray, we found that ?(1D)-AR gene was dramatically upregulated in 22-week-old ZD rats compared to ZL controls. Quantitative PCR analysis verified a 16-fold increase in ?(1D)-AR mRNA in renal cortex from ZD animals compared to normal controls. Chronic treatment with fenofibrate or rosiglitazone reduced renal cortical ?(1D)-AR gene. Immunofluorescence staining confirmed that ?(1D)-AR protein was induced in the glomeruli and tubules of diabetic rats. Moreover, dual immunostaining for ?(1D)-AR and kidney injury molecule-1 indicated that ?(1D)-AR was expressed in dedifferentiated proximal tubules of diabetic Zucker rats. Taken together, our results show that ?(1D)-AR expression is upregulated in the diabetic kidneys. PPAR activation suppressed renal expression of ?(1D)-AR in diabetic nephropathy. PMID:24772448
Zhao, Xueying; Zhang, Yuanyuan; Leander, Michelle; Li, Lingyun; Wang, Guoshen; Emmett, Nerimiah
2014-01-01
Alpha1D-adrenergic receptor (?1D-AR) plays important roles in regulating physiological and pathological responses mediated by catecholamines, particularly in the cardiovascular and urinary systems. The present study was designed to investigate the expression profile of ?1D-AR in the diabetic kidneys and its modulation by activation of peroxisome proliferator-activated receptors (PPARs). 12-week-old Zucker lean (ZL) and Zucker diabetic fatty (ZD) rats were treated with fenofibrate or rosigli...
Effect of the deformation operator in the D1D5 CFT
Carson, Zaq; Mathur, Samir D; Turton, David
2014-01-01
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.
Assessment of core thermo-hydrodynamic models of REFLA-1D with CCTF data
International Nuclear Information System (INIS)
In order to assess the core thermo-hydrodynamic models of REFLA-1D/MODE3, which is the latest version of REFLA-1D, several calculations of the core thermo-hydrodynamics have been performed for the CCTF Core-I series tests. The measured initial and boundary conditions were used for these calculations. The calculational results showed that the water accumulation model of Case 2 could predict the CCTF results fairly well as it could for the JAERI small scale facility. The calculated results for the base case and the EM tests were in good agreement with the CCTF data. The parameter effects, such as system pressure, initial clad temperature, Acc injection rate, LPCI injection rate and initial down-comer wall temperature, were predicted correctly, except for the high system pressure and the high LPCI injection rate tests. (author)
FPGA Implementation of Efficient VLSI Architecture for Fixed Point 1-D DWT Using Lifting Scheme
Directory of Open Access Journals (Sweden)
Durga Sowjanya
2012-09-01
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.
Rotating condensed-boson gases in a 1D lattice at finite temperature
Hassan, Ahmed S.; Soliman, Shemi S. M.
2015-02-01
In this paper, we study the thermodynamic properties of a rotating boson gases in a one-dimensional (1D) optical lattice at finite temperature. Our system is formed by loading three-dimensional boson-clouds into 1D optical lattice and subjected to rotate with angular velocity ? about the z-axis (rotating condensate in a quasi-two-dimensional trap). We employ the semiclassical approximation to calculate the condensate fraction, critical temperature and the heat capacity of the system. The calculated results show that the rotating condensates in a quasi-two-dimensional have interesting properties which are absent in both three or pure two-dimensional systems. Our results can be extended to investigate the current experiments of rotating Bose-Einstein condensation produced or transferred in one-dimensional optical lattices.
Magnetic Anticrossing of 1D Subbands in Coupled Ballistic Double Quantum Wires
International Nuclear Information System (INIS)
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
Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image
Directory of Open Access Journals (Sweden)
Niraj Shakhakarmi
2012-01-01
Full Text Available Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.
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)
Na-ion dynamics in Quasi-1D compound NaV2O4
Månsson, M.; Umegaki, I.; Nozaki, H.; Higuchi, Y.; Kawasaki, I.; Watanabe, I.; Sakurai, H.; Sugiyama, J.
2014-12-01
We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV2O4. By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above Tdiff ? 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above Tdiff. Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV2O4 and related compounds in energy related applications.
Potentiometric, ESI MS and AM1d studies of lasalocid esters silver(I) complexes
Pankiewicz, Rados?aw; Kira, Jaromir; Schroeder, Grzegorz; Ossowski, Tadeusz; Brzezinski, Bogumi?
2006-01-01
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.
Static sign language recognition using 1D descriptors and neural networks
Solís, José F.; Toxqui, Carina; Padilla, Alfonso; Santiago, César
2012-10-01
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.
Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image
Shakhakarmi, Niraj
2012-01-01
Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.
From 0D to 1D modeling of tubular solid oxide fuel cell
International Nuclear Information System (INIS)
An analysis of tubular solid oxide fuel cell fuelled with humidified hydrogen is presented in the paper. Numerical calculations have been performed by means of 0D and 1D levels of the electrical current density vector prediction together with 3D level of continuity, momentum, energy and species transport modeling. It has been shown that constant current density assumption throughout the fuel cell, as in 0D model, gives some overestimation of voltage, power and temperature in comparison with 1D model. However, obtained characteristics are similar for both cases. Additionally, an influence of discretization segments number on the model prediction has been analyzed. The local changes of current density along the fuel cell tube are also presented. It is shown that for increasing values of average current density throughout the cell, relevant local values of current density decrease linearly with tube length.
Verification and comparison of four numerical schemes for a 1D viscoelastic blood flow model.
Wang, Xiaofei; Fullana, Jose-Maria; Lagrée, Pierre-Yves
2015-11-01
A reliable and fast numerical scheme is crucial for the 1D simulation of blood flow in compliant vessels. In this paper, a 1D blood flow model is incorporated with a Kelvin-Voigt viscoelastic arterial wall. This leads to a nonlinear hyperbolic-parabolic system, which is then solved with four numerical schemes, namely: MacCormack, Taylor-Galerkin, monotonic upwind scheme for conservation law and local discontinuous Galerkin. The numerical schemes are tested on a single vessel, a simple bifurcation and a network with 55 arteries. The numerical solutions are checked favorably against analytical, semi-analytical solutions or clinical observations. Among the numerical schemes, comparisons are made in four important aspects: accuracy, ability to capture shock-like phenomena, computational speed and implementation complexity. The suitable conditions for the application of each scheme are discussed. PMID:25145651
Beyond 1D: spectral line formation with 3D hydrodynamical model atmospheres of red giants
Collet, R; Trampedach, R
2007-01-01
We present the results of realistic, 3D, hydrodynamical, simulations of surface convection in red giant stars with varying effective temperatures and metallicities. We use the convection simulations as time-dependent, hydrodynamical, model atmospheres to compute spectral line profiles for a number of ions and molecules under the assumption of local thermodynamic equilibrium (LTE). We compare the results with the predictions of line formation calculations based on 1D, hydrostatic, model stellar atmospheres in order to estimate the impact of 3D models on the derivation of elemental abundances. We find large negative 3D-1D LTE abundance corrections (typically -0.5 to -1 dex) for weak low-excitation lines from molecules and neutral species in the very low metallicity cases. Finally, we discuss the extent of departures from LTE in the case of neutral iron spectral line formation.
1989-01-01
When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.
2012-07-19
Windmills have been used for hundreds of years to collect energy from the wind in order to pump water, grind grain, and more recently generate electricity. There are many possible designs for the blades of a wind generator and engineers are always trying new ones. Design and test your own wind generator, then try to improve it by running a small electric motor connected to a voltage sensor.
International Nuclear Information System (INIS)
Steam generators for pressurized water reactors (PWR) with a U-bundle of boiler tubes, flowed around by the feedwater and a shell around the U-nest of boiler tubes which forms a fall space with the steam generator housing, and with a preheater enclosing the cold shank of the U-bundle of boiler tubes, in which at least a portion of the feedwater supplied to the steam generator flows in the direction of the tube plate. (orig./RW)
Liu, Zhong; Shi, Ming-Zhu; Xie, De-Yu
2014-04-01
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
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
Ewing, R.; Iliev, O.; Lazarov, R.; Naumovich, A.
2004-01-01
Finite difference discretizations of 1D poroelasticity equations with discontinuous coefficients are analyzed. A recently suggested FD discretization of poroelasticity equations with constant coefficients on staggered grid, [5], is used as a basis. A careful treatment of the interfaces leads to harmonic averaging of the discontinuous coefficients. Here, convergence for the pressure and for the displacement is proven in certain norms for the scheme with harmonic averaging (HA). Order of conv...
Amplification Effects on the Transmission and Reflexion Phases in 1D Periodic Systems
Zekri, N.; Bennabi, K.; Maarouf, S.
1999-01-01
We investigate the localization observed recently for locally non-hermitian Hamiltonians by studying the effect of the amplification on the scaling behavior of the transmission and reflection phases in 1D periodic chains of $\\delta$-potentials. The amplification here is represented by an imaginary term added to the on-site potential. It is found that both phases of the transmission and reflection amplitudes are strongly affected by the amplification term. In particular, the ...
On a 2D zoom for 1D shallow-water model: coupling and data assimilation
Monnier, Jerome; Gejadze, Igor
2007-01-01
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...
Large frequency range of negligible transmission in 1D photonic quantum well structures
Zi, J.; Wan, J.; Zhang, C.
1998-01-01
We show that it is possible to enlarge the range of low transmission in 1D photonic crystals by using photonic quantum well structures. If a defect is introduced in the photonic quantum well structures, defect modes with a very high quality factor may appear. The transmission of the defect mode is due to the coupling between the eigenmodes of the defect and those at the band edges of the constituent photonic crystals.
Finite Time Blow Up for a 1D Model of 2D Boussinesq System
Choi, Kyudong; Kiselev, Alexander; Yao, Yao
2015-03-01
The 2D conservative Boussinesq system describes inviscid, incompressible, buoyant fluid flow in a gravity field. The possibility of finite time blow up for solutions of this system is a classical problem of mathematical hydrodynamics. We consider a 1D model of the 2D Boussinesq system motivated by a particular finite time blow up scenario. We prove that finite time blow up is possible for the solutions to the model system.
Ground-state energy for 1D (t,U,X)-model at low densities
International Nuclear Information System (INIS)
In describing the properties of quasi-1D materials with a highly-screened interelectronic potential, an attractive hopping term has to be added to the Hubbard Hamiltonian. The effective interaction and the ground-state energy in ladder approximation are analyzed. At low electronic densities, the attractive part of the interaction, initially smaller than the repulsive term, can become more effective, the ground-state energy decreasing below the unperturbed value. (author). 12 refs, 4 figs
Exact results for the 1D mixed Bose-Fermi interacting gas
Batchelor, M T; Guan, X W; Oelkers, N
2005-01-01
The exact solution of the 1D mixed Bose-Fermi interacting gas is used to calculate ground state properties both for finite systems and in the thermodynamic limit. The quasimomentum distribution, ground state energy and generalized velocities are obtained as functions of the interaction strength both for polarized and non-polarized fermions. We do not observe any demixing instability of the system for repulsive interactions.
Collective dispersion relations for the 1D interacting two-component Bose and Fermi gases
Batchelor, M T; Guan, X W; Oelkers, N
2006-01-01
We investigate the elementary excitations of charge and spin degrees for the 1D interacting two-component Bose and Fermi gases by means of the discrete Bethe ansatz equations. Analytic results in the limiting cases of strong and weak interactions are derived, where the Bosons are treated in the repulsive and the fermions in the strongly attractive regime. We confirm and complement results obtained previously from the Bethe ansatz equations in the thermodynamic limit.
Resistivity structure of Sumatran Fault (Aceh segment) derived from 1-D magnetotelluric modeling
Nurhasan, Sutarno, D.; Bachtiar, H.; Sugiyanto, D.; Ogawa, Y.; Kimata, F.; Fitriani, D.
2012-06-01
Sumatran Fault Zone is the most active fault in Indonesia as a result of strike-slip component of Indo-Australian oblique convergence. With the length of 1900 km, Sumatran fault was divided into 20 segments starting from the southernmost Sumatra Island having small slip rate and increasing to the north end of Sumatra Island. There are several geophysical methods to analyze fault structure depending on physical parameter used in these methods, such as seismology, geodesy and electromagnetic. Magnetotelluric method which is one of geophysical methods has been widely used in mapping and sounding resistivity distribution because it does not only has the ability for detecting contras resistivity but also has a penetration range up to hundreds of kilometers. Magnetotelluric survey was carried out in Aceh region with the 12 total sites crossing Sumatran Fault on Aceh and Seulimeum segments. Two components of electric and magnetic fields were recorded during 10 hours in average with the frequency range from 320 Hz to 0,01 Hz. Analysis of the pseudosection of phase and apparent resistivity exhibit vertical low phase flanked on the west and east by high phase describing the existence of resistivity contras in this region. Having rotated the data to N45°E direction, interpretation of the result has been performed using three different methods of 1D MT modeling i.e. Bostick inversion, 1D MT inversion of TM data, and 1D MT inversion of the impedance determinant. By comparison, we concluded that the use of TM data only and the impedance determinant in 1D inversion yield the more reliable resistivity structure of the fault compare to other methods. Based on this result, it has been shown clearly that Sumatra Fault is characterized by vertical contras resistivity indicating the existence of Aceh and Seulimeum faults which has a good agreement with the geological data.
D1/D2 Domain of Large-Subunit Ribosomal DNA for Differentiation of Orpinomyces spp.?
Dagar, Sumit S.; Kumar, Sanjay; Mudgil, Priti; Singh, Rameshwar; Puniya, Anil K.
2011-01-01
This study presents the suitability of D1/D2 domain of large-subunit (LSU) ribosomal DNA (rDNA) for differentiation of Orpinomyces joyonii and Orpinomyces intercalaris based on PCR-restriction fragment length polymorphism (RFLP). A variation of G/T in O. intercalaris created an additional restriction site for AluI, which was used as an RFLP marker. The results demonstrate adequate heterogeneity in the LSU rDNA for species-level differentiation.
Neutronics/thermal-hydraulics coupled axial 1D model for SCWR core static analysis
International Nuclear Information System (INIS)
In order to study the issue of stability that may exist in SCWR core caused by fluid flow and neutronics/TH coupling, a simplified axial 1D single channel model is developed to do neutronics/thermal-hydraulics coupled SCWR core analysis. The United States SCWR reference core design is studied and results obtained are found to be comparable to the reference ones. Further transient studies on SCWR stability are carrying on based on this static model. (authors)
Multi-particle processes in $\\kappa$-Poincar\\'e inspired by 2+1D gravity
Kowalski-glikman, Jerzy; Rosati, Giacomo
2014-01-01
Inspired by a Chern-Simons description of 2+1D gravity coupled to point particles we propose a new Lagrangian of a multiparticle system living in $\\kappa$-Minkowski/$\\kappa$-Poincar\\'e spacetime. We derive the dynamics of interacting particles with $\\kappa$-momentum space, alternative to the one proposed in the "principle of relative locality" literature. In this construction the locality of particle processes is naturally implemented, even for distant observers. In particul...
Stochastic and Deterministic Vector Chromatography of Suspended Particles in 1D-Periodic Potentials
Bernate, Jorge A.; Drazer, German
2011-01-01
We present a comprehensive description of vector chromatography that includes deterministic and stochastic transport in 1D-periodic free-energy landscapes, with both energetic and entropic contributions, and highlights the parameters governing the deflection angle, i.e. the Peclet number and the partition ratio. We also investigate the dependence of the deflection angle on the shape of the free-energy landscape by varying the width of the linear transitions in an otherwise d...
Line shape of the non-thermal 6300 A O/1D/ emission
Schmitt, G. A.; Abreu, V. J.; Hays, P. B.
1982-01-01
The two-population model of Schmitt, Abreu and Hays (1981) is used to calculate the line shape of the atomic oxygen metastable state, nonthermal O(1D) 6300 A emission, in order to simulate observations made from a space platform at different zenith angles and altitudes. The Addition theorem, for spherical harmonics of a Legendre polynomial expansion of the nonthermal population distribution function, is used to obtain nonthermal line shapes observed at zenith angles other than the local vertical one.
Pitchfork-Hopf bifurcations in 1D neural field models with transmission delays
Dijkstra, K.; Gils, S. A. van; Janssens, S. G.; Kuznetsov, Yu. A.; Visser, S.
2015-03-01
Recently, local bifurcation theory for delayed neural fields was developed. In this paper, we show how symmetry arguments and residue calculus can be used to simplify the computation of the spectrum in special cases and the evaluation of the normal form coefficients, respectively. This is done hand in hand with an extensive study of two pitchfork-Hopf bifurcations for a 1D neural field model with 'Wizard hat' type connectivity.
Zero finite-temperature charge stiffness within the half-filled 1D Hubbard model
International Nuclear Information System (INIS)
Even though the one-dimensional (1D) Hubbard model is solvable by the Bethe ansatz, at half-filling its finite-temperature T>0 transport properties remain poorly understood. In this paper we combine that solution with symmetry to show that within that prominent T=0 1D insulator the charge stiffness D(T) vanishes for T>0 and finite values of the on-site repulsion U in the thermodynamic limit. This result is exact and clarifies a long-standing open problem. It rules out that at half-filling the model is an ideal conductor in the thermodynamic limit. Whether at finite T and U>0 it is an ideal insulator or a normal resistor remains an open question. That at half-filling the charge stiffness is finite at U=0 and vanishes for U>0 is found to result from a general transition from a conductor to an insulator or resistor occurring at U=Uc=0 for all finite temperatures T>0. (At T=0 such a transition is the quantum metal to Mott–Hubbard-insulator transition.) The interplay of the ?-spin SU(2) symmetry with the hidden U(1) symmetry beyond SO(4) is found to play a central role in the unusual finite-temperature charge transport properties of the 1D half-filled Hubbard model. -- Highlights: •The charge stiffness of the half-filled 1D Hubbard model is evaluated. •Its value is controlled by the model symmetry operator algebras. •We find that there is no charge ballistic transport at finite temperatures T>0. •The hidden U(1) symmetry controls the U=0 phase transition for T>0
Modeling Soil Salt and Nitrogen Transport under Different Fertigation Practices with Hydrus-1D
Zeng Wen-zhi; Huang Jie-sheng; Wu Jing-wei; Xu Chi
2013-01-01
In this study the effects of different fertigation practices on salt and nitrogen dynamics were analyzed in the Hetao District, China by using the Hydrus-1D model. The results indicated that the soil electrical conductivity increased gradually with depth after irrigation and the electrical conductivity of 0~60 cm depth changed faster than that of 60~100 cm depth. However, the soil ammonium nitrogen concentration decreased with depth and high irrigation intensity could promote the increase of ...
Spectral Flow of the Non-Supersymmetric Microstates of the D1-D5-KK System
Al-Alawi, Jassem H
2009-01-01
We show that a realisation of spectral flow as a coordinate transformation for asymptotically four-dimensional solutions can be extended to the non-supersymmetric case. We apply this transformation to smooth geometries describing microstates of the D1-D5-KK monopole system in type IIB supergravity compactified on a six-torus, and obtain solutions with an additional momentum charge. We study the supersymmetric and near-core limits of this construction.
MNM1D: A Numerical Code for Colloid Transport in Porous Media: Implementation and Validation
Directory of Open Access Journals (Sweden)
Tiziana Tosco
2009-01-01
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.
A Note on D1-D5 Entropy and Geometric Quantization
Krishnan, Chethan
2015-01-01
We quantize the space of 2-charge fuzzballs in IIB supergravity on $K3$. The resulting entropy precisely matches the D1-D5 black hole entropy, including a specific numerical coefficient. A partial match (ie., a smaller coefficient) was found by Rychkov a decade ago using the Lunin-Mathur subclass of solutions - we use a simple observation to generalize his approach to the full moduli space of $K3$ fuzzballs, filling a small gap in the literature.
(2+1)D surface solitons in virtue of the cooperation of nonlocal and local nonlinearities.
Kang, H Z; Zhang, T H; Wang, B H; Lou, C B; Zhu, B G; Ma, H H; Liu, S M; Tian, J G; Xu, J J
2009-11-01
We introduce a type of (2+1)D surface soliton in virtue of the cooperation of nonlocal and local nonlinearities. Furthermore, taking advantage of diffusion and drift nonlinearity this type of surface soliton is demonstrated theoretically and experimentally in a storintium barium nitrate crystal. The dynamics behavior of the excitation and propagation of this type of surface soliton are studied using the beam-propagation method and the nonlinear equation of light rays. PMID:19881573
A facile route for 3D aerogels from nanostructured 1D and 2D materials
Sung Mi Jung; Hyun Young Jung; Dresselhaus, Mildred S.; Yung Joon Jung; Jing Kong
2012-01-01
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...
Scaling of localization length of a quasi 1D system with longitudinal boundary roughness
International Nuclear Information System (INIS)
We introduce irregularities on one of the longitudinal boundaries of a quasi 1D strip which has no bulk disorder. We calculate the localization length of such a system within the scope of tight-binding formalism and see how it behaves with the roughness introduced on the boundary and with the strip-width. We find that localization length scales with a composite one parameter. (author). 6 refs, 4 figs
1D Cahn-Hilliard dynamics: Ostwald ripening and application to modulated phase systems
International Nuclear Information System (INIS)
We use a family of stationary solution of the Cahn-Hilliard dynamics in order to describe the coalescence during a first order phase transition. With this analytical ansatz, we compute the characteristic time for one step of period doubling in Langer's self similar scenario for Ostwald ripening. As an application, the same ansatz is also used to compute the thermodynamically stable period of a 1D modulated phase pattern, described by a Cahn-Hilliard dynamics with long range interaction terms
EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP
Energy Technology Data Exchange (ETDEWEB)
B. D. Ganapol; D. W. Nigg
2008-09-01
In the mid 80’s, a four-group/two-region, entirely analytical 1D nodal benchmark appeared. It was readily acknowledged that this special case was as far as one could go in terms of group number and still achieve an analytical solution. In this work, we show that by decomposing the solution to the multigroup diffusion equation into homogeneous and particular solutions, extension to any number of groups is a relatively straightforward exercise using the mathematics of linear algebra.
International Nuclear Information System (INIS)
The ''Generalized Riemann Problem'' (GRP) method is applied to 1-D compressible flows with material interfaces and variable cross section. The resulting scheme is second-order and used a ''mixed-type'' grid, where cell boundaries can be either Lagrangian or Eulerian. In fact, using the analytic resolution of discontinuities at cell boundaries, provided by the GRP solution, one can extend the scheme presented here to include any adaptive mesh
Ground-state spin structure of strongly interacting disordered 1D Hubbard model
International Nuclear Information System (INIS)
We study the influence of on-site disorder on the magnetic properties of the ground state of the infinite-U one-dimensional (1D) Hubbard model. We find that the ground state is not ferromagnetic. This is analysed in terms of the algebraic structure of the spin dependence of the Hamiltonian. A simple explanation is derived for the 1/N periodicity in the persistent current for this model. (author)
A Fulling-Kuchment theorem for the 1D harmonic oscillator
Guillemin, Victor
2011-01-01
We prove that there exists a pair of "non-isospectral" 1D semiclassical Schr\\"odinger operators whose spectra agree modulo h^\\infty. In particular, all their semiclassical trace invariants are the same. Our proof is based on an idea of Fulling-Kuchment and Hadamard's variational formula applied to suitable perturbations of the harmonic oscillator. Keywords: Inverse spectral problems, semiclassical Schr\\"odinger operators, trace invariants, Hadamard's variational formula, harmonic oscillator, Penrose mushroom, Sturm-Liouville theory.
Prediction of car cabin environment by means of 1D and 3D cabin model
Jícha M.; Pokorný J.; Fišer J.
2012-01-01
Thermal comfort and also reduction of energy requirements of air-conditioning system in vehicle cabins are currently very intensively investigated and up-to-date issues. The article deals with two approaches of modelling of car cabin environment; the first model was created in simulation language Modelica (typical 1D approach without cabin geometry) and the second one was created in specialized software Theseus-FE (3D approach with cabin geometry). Performance and capabilities of this t...
Valérian Guelpa; Laurent, Guillaume J.; Patrick Sandoz; July Galeano Zea; Cédric Clévy
2014-01-01
This paper presents a visual measurement method able to sense 1D rigid body displacements with very high resolutions, large ranges and high processing rates. Sub-pixelic resolution is obtained thanks to a structured pattern placed on the target. The pattern is made of twin periodic grids with slightly different periods. The periodic frames are suited for Fourier-like phase calculations—leading to high resolution—while the period difference allows the removal of phase ambiguity and thus a ...
Analysis of lumped parameter models for blood flow simulations and their relation with 1D models
Quarteroni, Alfio; Milisic, Vuk
2004-01-01
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...
High-Resolution Radiation Hybrid Map of Wheat Chromosome 1D
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
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...
Periodic Solutions of the 1D Vlasov-Maxwell System with Boundary Conditions
Bostan, Mihai
1998-01-01
We study the 1D Vlasov-Maxwell system with time periodic boundary conditions in its classical and relativistic form. For small data we prove existence of weak periodic solutions. It is necessary to impose non vanishing conditions for the incoming velocities in order to control the life-time of particles in the domain. In order to preserve the periodicity, another condition of vanishing the time average of the incoming current is imposed.
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)
FROM 1D TO 3D FERRIMAGNETS IN THE EDTA FAMILY
Coronado, E.; Sapin A, F.; Go?mez-romero, P.; Beltra?n, D.; Burriel, R.; Carlin, R.
1988-01-01
The results of increasing the dimensionality of a 1-d ferrimagnet to 2 and 3-d are discussed with reference to a novel 3-dimensional ordered phase based on the EDTA ligand (MtM (M'EDTA)2 .4H2O). Low temperature magnetic susceptibility data for (MtMM') = (ZnNiNi), (CoNiNi) and (CoCoCo) are discussed on the basis of the magnetic sublattices involved.
Scotogenic Z2 or U(1)D model of neutrino mass with ?(27) symmetry
Ma, Ernest; Natale, Alexander
2014-06-01
The scotogenic model of radiative neutrino mass with Z2 or U(1)D dark matter is shown to accommodate ?(27) symmetry naturally. The resulting neutrino mass matrix is identical to either of two forms, one proposed in 2006, the other in 2008. These two structures are studied in the context of present neutrino data, with predictions of CP violation and neutrinoless double beta decay.
Duality in N=1, D=10 Superspace and Supergravity with Tree Level Superstring Corrections
Saulina, N. A.; Terentiev, M. V.; Zyablyuk, K. N.
1995-01-01
The equations of motion (e.m.'s) of the N=1, D=10 anomaly free supergravity, obtained in the framework of the superspace approach, are analyzed. The formal equivalence of the usual and dual supergravities is discussed at the level of e.m.'s. The great simplicity of the dual formulation is established. The possibillity of the lagrangian formulation of the dual supergravity is pointed out. The bosonic part of the lagrangian is constructed including anomaly compensating superst...
A new method for determining dipole-dipole energy in 1D and 2D systems
Naumov, I I; Naumov, Ivan I.; Fu, Huaxiang
2005-01-01
An alternative method for computing dipole-dipole interaction energy in systems of 1D and 2D periodicity like nanowires, nanotubes and thin films is presented. The approach is based on the use of periodic Green's functions that satisfy Laplace's equation and are analytically determined. The method, when combined with short-ranged interaction as in effective Hamiltonian, is suitable for studying finite-temperature properties of low-dimensional ferroelectric systems.
Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons
Energy Technology Data Exchange (ETDEWEB)
Zhou, Lihui, E-mail: lhzhou@ecust.edu.cn; Zhang, Fang; Li, Jinxia
2014-02-15
One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO{sub 2} ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose solution under N{sub 2} flow at different temperatures. The phase transformation process of hydrogen titanate ribbons was investigated by in-situ X-ray diffraction at various temperatures. Besides, one-dimensional carbon-modified TiO{sub 2} ribbons calcined at different temperatures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption isotherms, diffuse reflectance ultraviolet–visible spectroscopy, and so on. Carbon-modified TiO{sub 2} ribbons showed one-dimensional ribbon crystal structure and various crystal phases of TiO{sub 2}. After being modified with carbon, a layer of uniform carbon film was coated on the surface of TiO{sub 2} ribbons, which improved their adsorption capacity for methyl orange as a model organic pollutant. One-dimensional carbon-modified TiO{sub 2} ribbons also exhibited enhanced visible-light absorbance with the increase of calcination temperatures. - Highlights: • The synthesis of 1D carbon-modified TiO{sub 2} ribbons. • The phase transformation of 1D carbon-modified TiO{sub 2} ribbons. • 1D carbon-modified TiO{sub 2} exhibites enhanced visible-light absorbance.
Tunable evolutions of wave modes and bandgaps in quasi-1D cylindrical phononic crystals
Meidani, Mehrashk; Kim, Eunho; Li, Feng; Yang, Jinkyu; Ngo, Duc
2015-01-01
We investigate the tunable characteristics of mechanical waves propagating in quasi-1D phononic crystals composed of horizontally stacked short cylinders at various contact angles and offsets. According to the Hertzian contact theory, elastic compression of laterally-touching cylindrical bodies exhibits a various range of contact stiffness depending on their alignment angles. In this study, we first assemble cylindrical particles in various combinations of inclination angles and systematically examine their forming mechanisms of frequency bandgaps. We also investigate the effect of the rattling motions of cylindrical particles by introducing asymmetric center-of-mass offsets with respect to their contact points. We find that the frequency responses of these quasi-1D phononic crystals evolve into multiple band structures as we employ higher deviations of contact angles and offsets. We calculate the dispersive behavior of propagating waves using a discrete particle model for simple zero-offset cases, while we use a finite element method for simulating the rattling motions of particles under non-zero offsets. We report branching behavior of frequency band structures and the evolution of their vibration modes as we manipulate the contact angles and offsets of the phononic crystals. This study implies that we can leverage the versatile wave filtering characteristics of quasi-1D phononic crystals to construct tunable wave filtering devices for engineering applications.
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)
Transient dynamic and modeling parameter sensitivity analysis of 1D solid oxide fuel cell model
International Nuclear Information System (INIS)
Highlights: • A multiphysics, 1D, dynamic SOFC model is developed. • The presented model is validated experimentally in eight different operating conditions. • Electrochemical and thermal dynamic transient time expressions are given in explicit forms. • Parameter sensitivity is discussed for different semi-empirical parameters in the model. - Abstract: In this paper, a multiphysics solid oxide fuel cell (SOFC) dynamic model is developed by using a one dimensional (1D) modeling approach. The dynamic effects of double layer capacitance on the electrochemical domain and the dynamic effect of thermal capacity on thermal domain are thoroughly considered. The 1D approach allows the model to predict the non-uniform distributions of current density, gas pressure and temperature in SOFC during its operation. The developed model has been experimentally validated, under different conditions of temperature and gas pressure. Based on the proposed model, the explicit time constant expressions for different dynamic phenomena in SOFC have been given and discussed in detail. A parameters sensitivity study has also been performed and discussed by using statistical Multi Parameter Sensitivity Analysis (MPSA) method, in order to investigate the impact of parameters on the modeling accuracy
A radiation hybrid map of chromosome 1D reveals synteny conservation at a wheat speciation locus.
Michalak de Jimenez, Monika K; Bassi, Filippo M; Ghavami, Farhad; Simons, Kristin; Dizon, Rissa; Seetan, Raed I; Alnemer, Loai M; Denton, Anne M; Do?ramac?, Münevver; Šimková, Hana; Doležel, Jaroslav; Seth, Kiran; Luo, Ming-Cheng; Dvorak, Jan; Gu, Yong Qiang; Kianian, Shahryar F
2013-03-01
The species cytoplasm specific (scs) genes affect nuclear-cytoplasmic interactions in interspecific hybrids. A radiation hybrid (RH) mapping population of 188 individuals was employed to refine the location of the scs (ae) locus on Triticum aestivum chromosome 1D. "Wheat Zapper," a comparative genomics tool, was used to predict synteny between wheat chromosome 1D, Oryza sativa, Brachypodium distachyon, and Sorghum bicolor. A total of 57 markers were developed based on synteny or literature and genotyped to produce a RH map spanning 205.2 cR. A test-cross methodology was devised for phenotyping of RH progenies, and through forward genetic, the scs (ae) locus was pinpointed to a 1.1 Mb-segment containing eight genes. Further, the high resolution provided by RH mapping, combined with chromosome-wise synteny analysis, located the ancestral point of fusion between the telomeric and centromeric repeats of two paleochromosomes that originated chromosome 1D. Also, it indicated that the centromere of this chromosome is likely the result of a neocentromerization event, rather than the conservation of an ancestral centromere as previously believed. Interestingly, location of scs locus in the vicinity of paleofusion is not associated with the expected disruption of synteny, but rather with a good degree of conservation across grass species. Indeed, these observations advocate the evolutionary importance of this locus as suggested by "Maan's scs hypothesis." PMID:23479086
Neutronic analysis of the 1D and 1E banks reflux detection system
International Nuclear Information System (INIS)
Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely, the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal 235U concentration levels to reflux levels remain satisfactory detectable
Multicomponent Geochemical Transport Modeling Using Hydrus-1D and HP1
Simunek, Jirka; Jacques, Diederik; van Genuchten, Martinus Th.; Mallants, Dirk
2006-12-01
The transport of reactive contaminants in the subsurface is generally affected by a large number of nonlinear and often interactive physical, chemical, and biological processes. Simulating these processes requires a comprehensive reactive transport code that couples the physical processes of water flow and advective-dispersive transport with a range of biogeochemical processes. Two recently developed coupled geochemical models that are both based on the HYDRUS-1D software package for variably saturated flow and transport are summarized in this paper. One model resulted from coupling HYDRUS1D with the UNSATCHEM module. While restricted to major ion chemistry, this program enables quantitative predictions of such problems as analyzing the effects of salinity on plant growth and the amount of water and amendments required to reclaim salt-affected soil profiles. The second model, HP1, resulted from coupling HYDRUS-1D with the PHREEQC biogeochemical code. The latter program accounts for a wide range of instantaneous or kinetic chemical and biological reactions, including complexation, cation exchange, surface complexation, precipitation dissolution and/or redox reactions. The versatility of HP1 is illustrated in this paper by means of two examples: the leaching of toxic trace elements and the transport of the explosive TNT and its degradation products.
Formaggia, Luca; Lamponi, Daniele; Tuveri, Massimiliano; Veneziani, Alessandro
2006-10-01
The investigations on the pressure wave propagation along the arterial network and its relationships with vascular physiopathologies can be supported nowadays by numerical simulations. One dimensional (1D) mathematical models, based on systems of two partial differential equations for each arterial segment suitably matched at bifurcations, can be simulated with low computational costs and provide useful insights into the role of wave reflections. Some recent works have indeed moved in this direction. The specific contribution of the present paper is to illustrate a 1D numerical model numerically coupled with a model for the heart action. Typically, the action of the heart on the arterial system is modelled as a boundary condition at the entrance of the aorta. However, the left ventricle (LV) and the vascular network are a strongly coupled single mechanical system. This coupling can be relevant in the numerical description of pressure waves propagation, particularly when dealing with pathological situations. In this work, we propose a simple lumped parameter model for the heart and show how it can be coupled numerically with a 1D model for the arteries. Numerical results actually confirm the relevant impact of the heart-arteries coupling in realistic simulations. PMID:17132614
Self-assembly of functional molecules into 1D crystalline nanostructures.
Guo, Yanbing; Xu, Liang; Liu, Huibiao; Li, Yongjun; Che, Chi-Ming; Li, Yuliang
2015-02-01
Self-assembled functional nanoarchitectures are employed as important nanoscale building blocks for advanced materials and smart miniature devices to fulfill the increasing needs of high materials usage efficiency, low energy consumption, and high-performance devices. One-dimensional (1D) crystalline nanostructures, especially molecule-composed crystalline nanostructures, attract significant attention due to their fascinating infusion structure and functionality which enables the easy tailoring of organic molecules with excellent carrier mobility and crystal stability. In this review, we discuss the recent progress of 1D crystalline self-assembled nanostructures of functional molecules, which include both a small molecule-derived and a polymer-based crystalline nanostructure. The basic principles of the molecular structure design and the process engineering of 1D crystalline nanostructures are also discussed. The molecular building blocks, self-assembly structures, and their applications in optical, electrical, and photoelectrical devices are overviewed and we give a brief outlook on crucial issues that need to be addressed in future research endeavors. PMID:25523368
Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons
International Nuclear Information System (INIS)
One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO2 ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose solution under N2 flow at different temperatures. The phase transformation process of hydrogen titanate ribbons was investigated by in-situ X-ray diffraction at various temperatures. Besides, one-dimensional carbon-modified TiO2 ribbons calcined at different temperatures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption isotherms, diffuse reflectance ultraviolet–visible spectroscopy, and so on. Carbon-modified TiO2 ribbons showed one-dimensional ribbon crystal structure and various crystal phases of TiO2. After being modified with carbon, a layer of uniform carbon film was coated on the surface of TiO2 ribbons, which improved their adsorption capacity for methyl orange as a model organic pollutant. One-dimensional carbon-modified TiO2 ribbons also exhibited enhanced visible-light absorbance with the increase of calcination temperatures. - Highlights: • The synthesis of 1D carbon-modified TiO2 ribbons. • The phase transformation of 1D carbon-modified TiO2 ribbons. • 1D carbon-modified TiO2 exhibites enhanced visible-light absorbance
Wang, Juven
2014-01-01
String and particle excitations are examined in a class of 3+1D topological order described by a discrete gauge theory with a gauge group $G$ and a 4-cocycle twist $\\omega_4 \\in \\mathcal{H}^4(G,\\mathbb{R}/\\mathbb{Z})$ of $G$'s cohomology group. We demonstrate the topological spin and the spin-statistics relation for the closed strings, and their multi-string braiding. The 3+1D twisted gauge theory can be characterized by a representation of SL$(3,\\mathbb{Z})$ modular transformation, which we find its generators $\\mathsf{S}^{xyz}$ and $\\mathsf{T}^{xy}$ in terms of the gauge group $G$ and the 4-cocycle $\\omega_4$. As we compactify one of the 3D's direction $z$ into a compact circle inserted with a gauge flux $b$, we can use the generators of SL$(2,\\mathbb{Z})$ subgroup of SL$(3,\\mathbb{Z})$, $\\mathsf{S}^{xy}$ and $\\mathsf{T}^{xy}$, to study the dimension reduction of the 3D topological order $\\mathcal{C}^{3\\text{D}}$ to a direct sum of degenerate states of 2D topological orders $\\mathcal{C}_b^{2\\text{D}}$ in di...
Kinetics and dynamics on the formation of S2(X3?g–,a1?g) in the S(1D) + OCS reaction.
Yamashita, Jun; Fujihara, Keigo; Takahashi, Osamu; Kohguchi, Hiroshi; Yamasaki, Katsuyoshi
2014-10-01
The reaction of electronically excited sulfur S((1)D) with OCS has exothermic channels generating S(2) in two electronic states X(3)?(g)– and a(1)?(g). The a(1)?(g) state is correlated directly to the reactants via the spin-allowed singlet surface; the X(3)?(g)– state, on the other hand, is a product of the spin-forbidden channel. There has been no report on kinetic evidence for the simultaneous generation of the two electronic states, although the two electronic states have been detected so far. The previous studies showed that little energy was released into rotation or vibration of the S(2) products despite large heats of reactions (228 and 175 kJ mol(-1) for generation of X(3)?(g)– and a(1)?(g), respectively). In the present study, S((1)D) was generated by the photolysis of OCS at 248 nm in a buffer He at 298 K, and the resulting two electronic states of S(2) (X(3)?(g)– and a(1)?(g)) were detected with dispersed laser-induced fluorescence (LIF) via the B(3)?(u)(-)–X(3)?(g)– and f(1)?(u)-a(1)?(g) transitions, respectively. Not only excitation but also dispersed fluorescence spectra made it possible to find a single rotational line of the vibrational level of interest. The time-resolved LIF intensities of the initial growth of the X(3)?(g)– and a(1)?(g) states showed identical OCS pressure dependences, giving the overall rate coefficient of the S(1D) + OCS reaction to be [3.2 ± 0.2(2?)] × 10(-10) cm3 molecule(-1) s(-1). The simultaneous generation of the two electronic states indicates that the intersystem crossing plays a role in opening the spin-forbidden channel. As for the reaction dynamics, vibrational levels up to v = 19 of X(3)?(g)– and 11 of a(1)?(g) have been detected, which is distinctly different from the previous studies. The reaction mechanism has been discussed on the basis of the potential energies reported so far. PMID:25188832
Michaeli, Walter; Berdel, Klaus; Osterbrink, Oliver
2009-06-01
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.
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)
Pre-test parameter sensitivity analysis for the KNGR DVI performance test using a 1-D module of MARS
Energy Technology Data Exchange (ETDEWEB)
Bae, Kyoo Hwan; Chung, Y. J.; Kim, H. C.; Bae, Y. Y.; Park, J. K
2001-06-01
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.
d?1 ? d?25 and constrained KP hierarchy from BRST invariance in the c?3 topological algebra
Gato-Rivera, B.; Semikhatov, A. M.
1993-05-01
The BRST invariance condition in a highest-weight representation of the topological (? twisted N=2) algebra captures the ‘invariant’ content of two-dimensional gravity coupled to matter. The topological algebra allows reductions to either the DDK-dressed matter or the ‘Kontsevich-Miwa’-dressed matter related to Virasoro-constrained KP hierarchy. The standard DDK formulation is recovered by splitting the topological generators into c=-26 reparametrization ghosts + matter + ‘Liouville,’ while a similar splitting involving c=-2 ghosts gives rise to the matter dressed in exactly the way required in order that the theory be equivalent to Virasoro constraints on the KP hierarchy. The two dressings of matter with the ‘Liouville’ differ also by their ‘ghost numbers,’ which is similar to the existence of representatives of BRST cohomologies with different ghost numbers. The topological central charge c?3 provides a two-fold covering of the allowed region d?1 ? d?25 of the matter central charge d via d=(c+1)(c+6)/(c-3). The ‘Liouville’ field is identified as the ghost-free part of the topological U(1) current. The construction thus allows one to establish a direct relation (presumably an equivalence) between the Virasoro-constrained KP hierarchies, minimal models, and the BRST invariance condition for highest-weight states of the topological algebra.
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.
Position error in profiles retrieved from MIPAS observations with a 1-D algorithm
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M. Carlotti
2012-09-01
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.
Development of 1D Particle-in-Cell Code and Simulation of Plasma-Wall Interactions
Rose, Laura P.
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.
International Nuclear Information System (INIS)
A radioisotope generator is described in which it is possible to interupt the elution process at any desired time, i.e. before the electron flacon is full. The interuption is performed in such a way that sterile air is simultaneously admitted into the generator, into both the column and the elution flacon. (Th.P.)
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)
Error estimates for 1D asymptotic models in coaxial cables with non-homogeneous cross-section
Imperiale, Se?bastien; Patrick, Joly
2012-01-01
This paper is the first contribution towards the rigorous justification of asymptotic 1D models for the time-domain simulation of the propagation of elec- tromagnetic waves in coaxial cables. Our general objective is to derive error esti- mates between the "exact" solution of the full 3D model and the "approximate" solution of the 1D model known as the Telegraphist's equation.
Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals
Energy Technology Data Exchange (ETDEWEB)
K.R. Maskaly
2005-06-01
Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with increasing RMS roughness. Again, the homogenization approximation is able to predict these results. The problem of surface scratches on 1D photonic crystals is also addressed. Although the reflectivity decreases are lower in this study, up to a 15% change in reflectivity is observed in certain scratched photonic crystal structures. However, this reflectivity change can be significantly decreased by adding a low index protective coating to the surface of the photonic crystal. Again, application of homogenization theory to these structures confirms its predictive power for this type of imperfection as well. Additionally, the problem of a circular pores in 2D photonic crystals is investigated, showing that almost a 50% change in reflectivity can occur for some structures. Furthermore, this study reveals trends that are consistent with the 1D simulations: parameter changes that increase the absolute reflectivity of the photonic crystal will also increase its tolerance to structural imperfections. Finally, experimental reflectance spectra from roughened 1D photonic crystals are compared to the results predicted computationally in this thesis. Both the computed and experimental spectra correlate favorably, validating the findings presented herein.
Hsi-Ping, Liu
1990-01-01
Impulse responses including near-field terms have been obtained in closed form for the zero-offset vertical seismic profiles generated by a horizontal point force acting on the surface of an elastic half-space. The method is based on the correspondence principle. Through transformation of variables, the Fourier transform of the elastic impulse response is put in a form such that the Fourier transform of the corresponding anelastic impulse response can be expressed as elementary functions and their definite integrals involving distance angular frequency, phase velocities, and attenuation factors. These results are used for accurate calculation of shear-wave arrival rise times of synthetic seismograms needed for data interpretation of anelastic-attenuation measurements in near-surface sediment. -Author
International Nuclear Information System (INIS)
A pressurized-water coolant nuclear reactor steam generator has a vertical housing for the steam generating water and contains an upstanding heat exchanger to which the pressurized-water coolant passes and which is radially surrounded by a guide jacket supporting a water separator on its top. By thermosiphon action the steam generating water flows upward through and around the heat exchanger within the guide chamber to the latter's top from which it flows radially outwardly and downwardly through a down draft space formed between the outside of the jacket and the housing. (Official Gazette)
International Nuclear Information System (INIS)
Radionuclide generators offer good possibilities for the production of short lived radioisotopes gamma, positron, alpha, beta or beta/gamma emitters. Several such systems, like 99 Mo/ 99m Tc or 81 Rb/ 81m Kr, as well as the generators for the production of positron emitters 68 Ga or 82 Rb, are already in routine production. It can be expected that in the near future the alpha emitters 212,213 Bi and beta/gamma emitting 188 Re will be obtained by using appropriate generator systems. New approaches in the production of radioisotopes and the separation of daughter in the generator are needed. Also new molecule carriers for their transport to the target organ or tissue should be developed (author)
Cole, T.
1985-01-01
Small modular alkali metal thermoelectric generator with no moving parts directly converts heat to electrical energy with efficiency of 20 to 40 percent. Unit uses closed regenerative electrochemical concentration cell based on sodium-ion conductor beta alumina.
NMR 1D-imaging of water infiltration into meso-porous matrices
International Nuclear Information System (INIS)
It is shown that coupling nuclear magnetic resonance (NMR) 1D-imaging with the measure of NMR relaxation times and self-diffusion coefficients can be a very powerful approach to investigate fluid infiltration into porous media. Such an experimental design was used to study the very slow seeping of pure water into hydrophobic materials. We consider here three model samples of nuclear waste conditioning matrices which consist in a dispersion of NaNO3 (highly soluble) and/or BaSO4 (poorly soluble) salt grains embedded in a bitumen matrix. Beyond studying the moisture progression according to the sample depth, we analyze the water NMR relaxation times and self-diffusion coefficients along its 1D-concentration profile to obtain spatially resolved information on the solution properties and on the porous structure at different scales. It is also shown that, when the relaxation or self-diffusion properties are multimodal, the 1D-profile of each water population is recovered. Three main levels of information were disclosed along the depth-profiles. They concern (i) the water uptake kinetics, (ii) the salinity and the molecular dynamics of the infiltrated solutions and (iii) the microstructure of the water-filled porosities: open networks coexisting with closed pores. All these findings were fully validated and enriched by NMR cryo-poro-metry experiments and by performing environmental scanning electronic microscopy observations. Surprisingly, results cleay observations. Surprisingly, results clearly show that insoluble salts enhance the water progression and thereby increase the capability of the material to uptake water. (authors)
Assessment and improvement of the 2D/1D method stability in DeCART
International Nuclear Information System (INIS)
As part of ongoing work with Consortium for Advanced Simulation of Light Water Reactors (CASL), the 2D/1D code, DeCART, has demonstrated some of the advantages of the 2D/1D method with respect to realistic, full-core analysis, particularly over explicit 3D transport methods, which generally have higher memory and computation requirements. The 2D/1D method performs 2D-radial transport sweeps coupled with ID-axial diffusion calculations to provide a full 3D simulation. DeCART employs the 2D method of characteristics for the radial sweeps and ID one-node nodal diffusion for the axial sweeps, coupling the two methods with transverse leakages to ensure a more consistent representation of the transport equation. It has been observed that refinement of the axial plane thickness leads to instabilities in the calculation scheme. This work assesses the sources of these instabilities and the approaches to improve them, especially with respect to negative scattering cross sections and the tightness of the 2D-radial/ID-axial coupling schemes. Fourier analyses show that the existing iteration scheme is not unconditionally stable, suggesting a tighter coupling scheme is required. For this reason 3D-CMFD has been implemented, among other developments, to ensure more stable calculation. A matrix of test cases has been used to assess the convergence, with the primary parameter being the axial plane thickness, which has been refined down to 1 cm. These cases demonstrate the issues observed and how the modification improve the stability. However, it is apparent that more work is necessary to ensure unconditional stability. (authors)
Nonthermal O(1S) and O(1D) populations in cometary atmospheres
Hubert, B. A.; Bisikalo, D. V.; Shematovich, V. I.; Gerard, J. M.; Decock, A.; Manfroid, J.; Hutsemekers, D.; Jehin, E.
2013-12-01
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.
1-D and 2-D electrophoresis protein profiles of the scorpion venom from Brotheas amazonicus
International Nuclear Information System (INIS)
Full text: Introduction: Scorpions venoms show specific neurotoxins to insect or mammals. These toxins are very important molecular tools to development of news drugs or bioinsecticides. Brotheas amazonicus scorpion is an endemic specie in Amazonian Rain Forest, but your venom do not show toxicity in humans. Information about biological specific activity on insect of this venom is not known yet. Objectives: Molecular protein toxins profiles of the venom from Brotheas amazonicus scorpion by 1-D and 2-D electrophoresis methods to detected toxins with potential biotech applications. Results: Several spots 'families' with ? 60, 70 and 80 kDa were detected in gel acidic region with pI ? 4,5 - 6 range, in the same region 1-D zimography showed proteolytic activity on gelatin and fibrinogen and proteolytic activity was inhibited by PMSF, suggesting scorpion serine proteinases. 50 kDa proteins were detected with pI ? 6,5 - 7 range. In 23 - 50 kDa gel acid region were observed some proteins. In 23 - 14 kDa gel acidic region were detected proteins with pI 4 - 7 range. 1-D Tris-tricine gel showed proteins with ? 7 kDa, suggesting scorpion neurotoxins. In gel basic region only 14 kDa proteins were observed with pI ? 9 - 10 range. Conclusion: Molecular profile of the scorpion venom from B. amazonicus showed proteins with high and low molecular masses, mainly with acidic pI. Proteolytic activity suggest serine proteinases with high molecular masses and 7 kDa proteins in B. masses and 7 kDa proteins in B. amazonicus venom suggest scorpion neurotoxins. Purification and molecular characterization of these toxins are in course
1D-3D registration for intra-operative nuclear imaging in radio-guided surgery.
Vetter, Christoph; Lasser, Tobias; Okur, Asli; Navab, Nassir
2015-02-01
3D functional nuclear imaging modalities like SPECT or PET provide valuable information, as small structures can be marked with radioactive tracers to be localized before surgery. This positional information is valuable during surgery as well, for example when locating potentially cancerous lymph nodes in the case of breast cancer. However, the volumetric information provided by pre-operative SPECT scans loses validity quickly due to posture changes and manipulation of the soft tissue during surgery. During the intervention, the surgeon has to rely on the acoustic feedback provided by handheld gamma-detectors in order to localize the marked structures. In this paper, we present a method that allows updating the pre-operative image with a very limited number of tracked readings. A previously acquired 3D functional volume serves as prior knowledge and a limited number of new 1D detector readings is used in order to update the prior knowledge. This update is performed by a 1D-3D registration algorithm that registers the volume to the detector readings. This enables the rapid update of the visual guidance provided to the surgeon during a radio-guided surgery without slowing down the surgical workflow. We evaluate the performance of this approach using Monte-Carlo simulations, phantom experiments and patient data, resulting in a positional error of less than 8 mm which is acceptable for surgery. The 1D-3D registration is also compared to a volumetric reconstruction using the tracked detector measurements without taking prior information into account, and achieves a comparable accuracy with significantly less measurements. PMID:25343756
Bierwisch, Manfred
2009-01-01
Generative Grammar is the label of the most influential research program in linguistics and related fields in the second half of the 20. century. Initiated by a short book, Noam Chomsky's Syntactic Structures (1957), it became one of the driving forces among the disciplines jointly called the cognitive sciences. The term generative grammar refers to an explicit, formal characterization of the (largely implicit) knowledge determining the formal aspect of all kinds of language behavior. The pro...
Synthesis of 1D Bragg gratings by a layer-aggregation method.
Capmany, José; Muriel, Miguel A; Sales, Salvador
2007-08-15
We present what we believe to be a novel method for the synthesis of complex 1D (fiber and waveguide) Bragg gratings, which is based on an impedance reconstruction layer aggregation technique. The main advantage brought by the method is the possibility of synthesizing structures containing defects or discontinuities of the size of the local period, a feature that is not possible with prior reported methods. In addition, this enhanced spatial resolution allows the synthesis of very strong fiber Bragg grating devices providing convergent solutions. The method directly renders the refractive index profile n(z) as it does not rely on the coupled-mode theory. PMID:17700769
Bogoliubov coefficients for the twist operator in the D1D5 CFT
Carson, Zaq; Mathur, Samir D.; Turton, David
2014-01-01
The D1D5 CFT is a holographic dual of a near-extremal black hole in string theory. The interaction in this theory involves a twist operator which joins together different copies of a free CFT. Given a large number of D1 and D5 branes, the effective length of the circle on which the CFT lives is very large. We develop a technique to study the effect of the twist operator in the limit where the wavelengths of excitations are short compared to this effective length, which we ca...
Statistical mechanics of a one-component fluid of charged hard rods in 1D
International Nuclear Information System (INIS)
The statistical mechanics of a classical one component system of charged hard rods in a neutralizing background is investigated in 1D stressing on the effects of the hard core interactions over the thermodynamic and the structure of the system. The crystalline status of the system at all temperatures and densities and the absence of phase transitions is shown by extending previous results of Baxter and Kunz on the one-component plasma of point particles. Explicit expressions for the thermodynamic functions and the one-particle correlation function are given in the limits of small and strong couplings. (author)
Wave Mechanics of Two Hard Core Quantum Particles in 1-D Box
Jain, Yatendra S.
2006-01-01
The wave mechanics of two impenetrable hard core particles in 1-D box is analyzed. Each particle in the box behaves like an independent entity represented by a {\\it macro-orbital} (a kind of pair waveform). While the expectation value of their interaction, $$, vanishes for every state of two particles, the expectation value of their relative separation, $$, satisfies $ \\ge \\lambda/2$ (or $q \\ge \\pi/d$, with $2d = L$ being the size of the box). The particles in their ground s...
1-D transport model for analysis of expanding radius and full bore startup of tokamak plasmas
International Nuclear Information System (INIS)
This report describes the physics models and numerical algorithms that have been used in the WHIST one-dimensional (1-D) transport code to study expanding radius vs full bore startup scenarios for tokamak plasmas. The phase of the tokamak discharge that is modeled is the time segment following plasma breakdown (and initial current channel formation) up to ignition. The code has been applied to the Oak Ridge National Laboratory (ORNL) The Next Step (TNS) reference design. The various physics models are presented, and references are made to benchmarking calculations when they exist
Statistical error analysis of transport calculations by a 1-D semianalytical method
International Nuclear Information System (INIS)
The known methods of performing uncertainty analysis by sensitivity studies are considered to be unsatisfying in some aspects. Apart from the limited availability and reliability of the covariance data, sensitivity studies are regarded as rather expensive. To reduce the latter a semianalytical method has been developed for solving the 1-dimensional linear Boltzmann equations on the basis of the well known spherical harmonics approximation. In the literature known round off errors can be avoided at least for P3 approximations and typical reactor configurations. Further approximations are not yet examined. The considerations concentrate on the formulation of analytical 1-D solutions as the application to statistical error calculations are straight forward. (author)
Review of Zero-D and 1-D Models of Blood Flow in the Cardiovascular System
Directory of Open Access Journals (Sweden)
Hose Rodney
2011-04-01
Full Text Available Abstract Background Zero-dimensional (lumped parameter and one dimensional models, based on simplified representations of the components of the cardiovascular system, can contribute strongly to our understanding of circulatory physiology. Zero-D models provide a concise way to evaluate the haemodynamic interactions among the cardiovascular organs, whilst one-D (distributed parameter models add the facility to represent efficiently the effects of pulse wave transmission in the arterial network at greatly reduced computational expense compared to higher dimensional computational fluid dynamics studies. There is extensive literature on both types of models. Method and Results The purpose of this review article is to summarise published 0D and 1D models of the cardiovascular system, to explore their limitations and range of application, and to provide an indication of the physiological phenomena that can be included in these representations. The review on 0D models collects together in one place a description of the range of models that have been used to describe the various characteristics of cardiovascular response, together with the factors that influence it. Such models generally feature the major components of the system, such as the heart, the heart valves and the vasculature. The models are categorised in terms of the features of the system that they are able to represent, their complexity and range of application: representations of effects including pressure-dependent vessel properties, interaction between the heart chambers, neuro-regulation and auto-regulation are explored. The examination on 1D models covers various methods for the assembly, discretisation and solution of the governing equations, in conjunction with a report of the definition and treatment of boundary conditions. Increasingly, 0D and 1D models are used in multi-scale models, in which their primary role is to provide boundary conditions for sophisticate, and often patient-specific, 2D and 3D models, and this application is also addressed. As an example of 0D cardiovascular modelling, a small selection of simple models have been represented in the CellML mark-up language and uploaded to the CellML model repository http://models.cellml.org/. They are freely available to the research and education communities. Conclusion Each published cardiovascular model has merit for particular applications. This review categorises 0D and 1D models, highlights their advantages and disadvantages, and thus provides guidance on the selection of models to assist various cardiovascular modelling studies. It also identifies directions for further development, as well as current challenges in the wider use of these models including service to represent boundary conditions for local 3D models and translation to clinical application.
Multi-particle processes in $\\kappa$-Poincar\\'e inspired by 2+1D gravity
Kowalski-Glikman, Jerzy
2014-01-01
Inspired by a Chern-Simons description of 2+1D gravity coupled to point particles we propose a new Lagrangian of a multiparticle system living in $\\kappa$-Minkowski/$\\kappa$-Poincar\\'e spacetime. We derive the dynamics of interacting particles with $\\kappa$-momentum space, alternative to the one proposed in the "principle of relative locality" literature. In this construction the locality of particle processes is naturally implemented, even for distant observers. In particular each particle process is characterized by a local deformed energy-momentum conservation law. On the other hand, the relation between non-causally-connected events still reflects the effects of deformed kinematics and relativity of locality.
Exponentially-convergent Monte Carlo for the 1-D transport equation
International Nuclear Information System (INIS)
We define a new exponentially-convergent Monte Carlo method for solving the one-speed 1-D slab-geometry transport equation. This method is based upon the use of a linear discontinuous finite-element trial space in space and direction to represent the transport solution. A space-direction h-adaptive algorithm is employed to restore exponential convergence after stagnation occurs due to inadequate trial-space resolution. This methods uses jumps in the solution at cell interfaces as an error indicator. Computational results are presented demonstrating the efficacy of the new approach. (authors)
S-Matrix for Magnons in the D1-D5 System
International Nuclear Information System (INIS)
We show that integrability and symmetries of the near horizon geometry of the D1-D5 system determine the S-matrix for the scattering of magnons in this system completely up to a phase. Using semi-classical methods we evaluate the phase to the leading and to the one-loop approximation in the strong coupling expansion. We then show that the phase obeys the unitarity constraint implied by the crossing relations to the one-loop order. We also verify that the dispersion relation obeyed by these magnons is one-loop exact at strong coupling which is consistent with their BPS nature. (author)
Semileptonic B Decays into Excited Charmed Mesons ($D_1$, $D^*_2$) in HQEFT
Wang, W. Y.; Wu, Y. L.
2000-01-01
Exclusive semileptonic B decays into excited charmed mesons ($D_1$, $D^*_2$) are studied up to the order of $1/m_Q$ in the framework of the heavy quark effective field theory (HQEFT), which contains the contributions of both particles and antiparticles. Two wave functions $\\eta^b_0$ and $\\eta^c_0$, which characterize the contributions from the kinematic operator at the order of $1/m_Q$, are calculated by using QCD sum rule approach in HQEFT. Zero recoil values of other two w...
International Nuclear Information System (INIS)
Using the interface response theory, we investigate the band structure and transmission of quasi-1D comb-like photonic waveguides with side branches composed of negative index materials. Numerical results exhibit the existence of discrete modes in band structure. These discrete modes are corresponding to narrow transmission bands which separated by large forbidden band in the transmission spectrum. Meanwhile it is shown that the narrow transmission bands become narrower with the increase of the number of side branches. The above properties are still maintained when the negative index materials are dispersive and lossy
Results and limits in the 1-D analytical modeling for the asymmetric DG SOI MOSFET
Cobianu, O.; Glesner, M.
2008-01-01
This paper presents the results and the limits of 1-D analytical modeling of electrostatic potential in the low-doped p type silicon body of the asymmetric n-channel DG SOI MOSFET, where the contribution to the asymmetry comes only from p- and n-type doping of polysilicon used as the gate electrodes. Solving Poisson's equation with boundary conditions based on the continuity of normal electrical displacement at interfaces and the presence of a minimum electrostatic potential by using the...
A novel 1D ? 2D interdigitated framework directed by hydrogen bonds
Yang, Jin-Xia; Zhang, Xin; Cheng, Jian-Kai; Yao, Yuan-Gen
2011-04-01
A novel Zn(?I) complex, [Zn(L1)(bpe)] ( 1) (H 2L1 = 5-(benzyloxy) isophthalic acid, bpe = 1,2-bis(4-pyridyl)ethane) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, IR and X-ray powder diffraction (PXRD). Compoud 1 features a one-dimensional (1D) open-ended tubular framework. These adjacent tubular frameworks are interdigitated into a two-dimensional (2D) supramolecular framework directed by hydrogen bonds. Moreover, this compound exhibits intense blue photoluminescence at room temperature.
Are there really phase transitions in 1-d heat conduction models?
Yang, Lei; Grassberger, Peter
2003-01-01
Recently, it has been claimed (O. V. Gendelman and A. V. Savin, Phys. Rev. Lett. {\\bf 84}, 2381 (2000); A.V.Savin and O.V.Gendelman, arXiv: cond-mat/0204631 (2002)) that two nonlinear classical 1-d lattice models show transitions, at finite temperatures, where the heat conduction changes from being finite to being infinite. These are the well known Frenkel-Kontorova (FK) model and a model for coupled rotators. For the FK model we give strong theoretical arguments why such a ...
Microfocusing transfocator for 1D and 2D compound refractive lenses.
Zozulya, A V; Bondarenko, S; Schavkan, A; Westermeier, F; Grübel, G; Sprung, M
2012-08-13
An x-ray transfocator design for the combined use of 1D and 2D compound refractive lenses is described. The device includes stacks of beryllium parabolic lenses with different radii of curvature and provides microfocused x-ray beams in the 4-20 keV photon energy range. The transfocator has been implemented at the P10 Coherence Beamline of the PETRA III synchrotron at DESY, Hamburg. Results of transfocator performance and applications for coherent x-ray scattering experiments are presented. PMID:23038536
Formulações semi-discretas para a equação 1D de Burgers
Scientific Electronic Library Online (English)
C.A., Ladeia; N.M.L., Romeiro; P.L., Natti; E.R., Cirilo.
2013-12-01
Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Neste trabalho fizemos comparações entre formulações semi-discretas para a obtenção de soluções numéricas para a equação 1D de Burgers. As formulações consistem em discretizar o domínio temporal via métodos implícitos multi-estágios de segunda e quarta ordem: aproximantes de Padé R11 e R22; e o domí [...] nio espacial via métodos de elementos finitos: mínimos quadrados (MEFMQ), Galerkin (MEFG) e Streamline-Upwind Petrov-Galerkin (SUPG). Conhecendo as soluções analíticas da equação 1D de Burgues, para diferentes condições iniciais e de fronteira, foram realizadas análises dos erros numéricos a partir das normas L2 e L?. Verificamos que o método com o aproximante de Padé R22 adicionado as formulações MEFMQ, MEFG e SUPG, aumentou a região de convergência das soluções numéricas e apresentou maior precisão quando comparado as soluções obtidas por meio do aproximante de Padé R11. Constatamos que o método R22 amenizou as oscilações das soluções numéricas associadas as formulações MEFG e SUPG. Abstract in english In this work we compare semi-discrete formulations to obtain numericalsolutions for the 1D Burgers equation. The formulations consist in the discretization ofthe time-domain via multi-stage methods of second and fourth order: R11 and R22 Padé approximants, and of the spatial-domain via finite elemen [...] t methods: least-squares (MEFMQ), Galerkin (MEFG) and Streamline-Upwind Petrov-Galerkin (SUPG). Knowing the analytical solutions of the 1D Burgues equation, for different initial and boundary conditions, analyzes were performed for numerical errors from L2 and L? norm. We found that the R22 Padé approximants, added to the MEFMQ, MEFG, and SUPG formulations, increased the region of convergence of the numerical solutions, and showed greater accuracy when compared to the solutions obtained by the R11 Padé approximants. We note that the R22 Padé approximants softened the oscillations of the numerical solutions associated to the MEFG and SUPG formulations.
A novel 3-D color histogram equalization method with uniform 1-D gray scale histogram.
Han, Ji-Hee; Yang, Sejung; Lee, Byung-Uk
2011-02-01
The majority of color histogram equalization methods do not yield uniform histogram in gray scale. After converting a color histogram equalized image into gray scale, the contrast of the converted image is worse than that of an 1-D gray scale histogram equalized image. We propose a novel 3-D color histogram equalization method that produces uniform distribution in gray scale histogram by defining a new cumulative probability density function in 3-D color space. Test results with natural and synthetic images are presented to compare and analyze various color histogram equalization algorithms based upon 3-D color histograms. We also present theoretical analysis for nonideal performance of existing methods. PMID:20801744
Spoof plasmon resonance with 1D periodic grooves for terahertz refractive index sensing
Zhang, Yusheng; Hong, Zhi; Han, Zhanghua
2015-04-01
We analyze the use of spoof plasmon resonance due to the excitation of spoof surface plasmons in a 1D array of rectangular grooves for terahertz refractive index sensing in an Otto configuration. The dependence of the resonant angle on the change of the refractive index is numerically investigated and a high angular sensitivity about S=320°/RIU is demonstrated, which leads to a high resolution of 3×10-7 RIU assuming 1×10-4 degree for angular resolution. We further show that by using a slanted geometry an even higher sensitivity up to 452°/RIU can be achieved. These results provide a novel method for terahertz refractive index sensing.
Electron impact excitation to the 3 1D state of magnesium from the ground state
International Nuclear Information System (INIS)
We calculate differential cross sections and Stokes parameters using the R-matrix method with 24, 32 and 38 target states for the transition from the 3s2 1S state to the 3s3d 1D state in magnesium by electron impact. Results at incident electron energies of 10 and 20 eV are obtained and compared with available experimental and theoretical results. Except at near forward-scattering angles at 10 eV, overall good agreement is found with measurements for the differential cross sections. (author)
Stark broadening of halogen atom lines from (1D)np levels
International Nuclear Information System (INIS)
We report results of a study of the Stark broadening of halogen atom lines from (1D)np levels. Wall stabilized arc is used as a plasma source. Electron densities 2.2-3.2x1022 m-3 are determined from the width of H? line and electron temperature 9300-10000 K from plasma composition data. The agreement with the results of simple semiclassical calculations is within the limits of the estimated errors of both experiment and theory. An explanation for the large discrepancy between theory and experiment detected for three BrI lines is offered. (orig.)
Monochromatic Neutron Tomography Using 1-D PSD Detector at Low Flux Research Reactor
International Nuclear Information System (INIS)
This paper describes the monochromatic neutron tomography experiment using the 1-D Position Sensitive Neutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work was performed using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principal main aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nm monochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters and features to characterize the system
Local source tomography for Vrancea (Romania) region: minimum 1D model
International Nuclear Information System (INIS)
The Vrancea zone is characterized by a narrow, vertical focal volume of intense and persistent seismicity in the depth range of 60-220 km. The processes associated with the Vrancea earthquakes outline a final stage of continental subduction with plate detachment, still far from being understood. Our main purpose is to perform local earthquake tomography to image crustal structures in Vrancea and adjacent regions as initial reference model in 3 D tomography. The study includes updating of the existing catalogues of seismic parameter data, calculation of a minimum 1D model and correlation with the existing controlled-source data. The model is determined by a trial-and-error process, with internal non-linear (iterative) inversion procedure (program VELEST). The average velocity model parameters are obtained by minimizing the standard deviations of the travel time residuals. The P-wave travel times for 500 well-locatable events are used, merging travel time data recorded by two separate independent seismic networks: the Romanian telemetered network (17 vertical-component S-13 seismometers) and the digital accelerometers network (30 three-component K2 instruments) installed in 1996 within the joint Romanian-German cooperation programme CRC 461. Since the two networks largely overlap geographically, we calculate a common minimum 1D model that guarantees a uniform location quality and uniform phase identification for the two networks. Absolute mislocation errors for the comb. Absolute mislocation errors for the combined networks using the minimum 1D model are calculated using quarry blast data obtained during the VRANCEA99 refraction experiment deployed in 1999 in Romania as a contribution to the CRC 461 programme. The resulted minimum 1D model and station corrections are used to relocate all the considered events and to improve the consistency in the phase identification. The station corrections obtained are correlated with the lateral velocity variations in the surface geology of the region. This paper is a preliminary contribution to the future seismic tomography study in the framework of the CALIXTO'99 project. (authors)
Binding and excitation energies of Lennard-Jones clusters in the 1/d-method
International Nuclear Information System (INIS)
We present simple estimates of the binding energies of clusters of rare-gas atoms and excitation energies of low-lying states in trimers, which are obtained by writing formally the Schroedinger equation in d dimensions and expanding its solution in powers of 1/d. Comparison with Monte Carlo calculations for Lennard-Jones clusters (Nen, Arn, Krn, Xen, n=3-7 and 13) shows good agreement, and suggests that our formulae may be used to estimate the energy of rare-gas atoms interacting through realistic potentials. (author). 24 refs, 1 fig., 2 tabs
Delocalization of Weakly Interacting Bosons in a 1D Quasiperiodic Potential
Michal, V. P.; Altshuler, B. L.; Shlyapnikov, G. V.
2014-07-01
We consider weakly interacting bosons in a 1D quasiperiodic potential (Aubry-Azbel-Harper model) in the regime where all single-particle states are localized. We show that the interparticle interaction may lead to the many-body delocalization and we obtain the finite-temperature phase diagram. Counterintuitively, in a wide range of parameters the delocalization requires stronger coupling as the temperature increases. This means that the system of bosons can undergo a transition from a fluid to insulator (glass) state under heating.
Yao, Ruiwen
2014-01-01
In contrast to traditional Navier equations, a more comprehensive formulation of one dimensional (1D) elastic wave equations is proposed for inhomogeneous media by using the coordinate transformation method. These modified equations are form-invariant and can retain time synchronization under spatial coordinate transformation, which are equivalent requirements from the principle of relativity. A numerical example is conducted to compare the distributions of wave speed calculated by the modified equations and Navier equations. It demonstrates that Navier equations are good approximations of the modified equations only when the wave frequency is sufficiently high.
Review of Zero-D and 1-D Models of Blood Flow in the Cardiovascular System
2011-01-01
Background Zero-dimensional (lumped parameter) and one dimensional models, based on simplified representations of the components of the cardiovascular system, can contribute strongly to our understanding of circulatory physiology. Zero-D models provide a concise way to evaluate the haemodynamic interactions among the cardiovascular organs, whilst one-D (distributed parameter) models add the facility to represent efficiently the effects of pulse wave transmission in the arterial network at greatly reduced computational expense compared to higher dimensional computational fluid dynamics studies. There is extensive literature on both types of models. Method and Results The purpose of this review article is to summarise published 0D and 1D models of the cardiovascular system, to explore their limitations and range of application, and to provide an indication of the physiological phenomena that can be included in these representations. The review on 0D models collects together in one place a description of the range of models that have been used to describe the various characteristics of cardiovascular response, together with the factors that influence it. Such models generally feature the major components of the system, such as the heart, the heart valves and the vasculature. The models are categorised in terms of the features of the system that they are able to represent, their complexity and range of application: representations of effects including pressure-dependent vessel properties, interaction between the heart chambers, neuro-regulation and auto-regulation are explored. The examination on 1D models covers various methods for the assembly, discretisation and solution of the governing equations, in conjunction with a report of the definition and treatment of boundary conditions. Increasingly, 0D and 1D models are used in multi-scale models, in which their primary role is to provide boundary conditions for sophisticate, and often patient-specific, 2D and 3D models, and this application is also addressed. As an example of 0D cardiovascular modelling, a small selection of simple models have been represented in the CellML mark-up language and uploaded to the CellML model repository http://models.cellml.org/. They are freely available to the research and education communities. Conclusion Each published cardiovascular model has merit for particular applications. This review categorises 0D and 1D models, highlights their advantages and disadvantages, and thus provides guidance on the selection of models to assist various cardiovascular modelling studies. It also identifies directions for further development, as well as current challenges in the wider use of these models including service to represent boundary conditions for local 3D models and translation to clinical application. PMID:21521508
Spin-waves in the pseudo 1-d ferromagnet RbFeCl3
International Nuclear Information System (INIS)
We have measured by means of neutron inelastic scattering the spin-wave dispersion in the pseudo 1-d ferromagnet RbFeCl3 at T=1.5 K. The observed dispersion in the hexagonal plane is found to disagree both with the planar triangular magnetic structure and with the small interchain exchange previously assumed. A new model with conical structure (theta=540) and Spin Hamiltonian parameters J=4.2 K J'=-1.2 K D*=8 K is proposed
Multiresolution image representation using combined 2-D and 1-D directional filter banks.
Tanaka, Yuichi; Ikehara, Masaaki; Nguyen, Truong Q
2009-02-01
In this paper, effective multiresolution image representations using a combination of 2-D filter bank (FB) and directional wavelet transform (WT) are presented. The proposed methods yield simple implementation and low computation costs compared to previous 1-D and 2-D FB combinations or adaptive directional WT methods. Furthermore, they are nonredundant transforms and realize quad-tree like multiresolution representations. In applications on nonlinear approximation, image coding, and denoising, the proposed filter banks show visual quality improvements and have higher PSNR than the conventional separable WT or the contourlet. PMID:19095538
Delocalization of weakly interacting bosons in a 1D quasiperiodic potential.
Michal, V P; Altshuler, B L; Shlyapnikov, G V
2014-07-25
We consider weakly interacting bosons in a 1D quasiperiodic potential (Aubry-Azbel-Harper model) in the regime where all single-particle states are localized. We show that the interparticle interaction may lead to the many-body delocalization and we obtain the finite-temperature phase diagram. Counterintuitively, in a wide range of parameters the delocalization requires stronger coupling as the temperature increases. This means that the system of bosons can undergo a transition from a fluid to insulator (glass) state under heating. PMID:25105630
Soliton phase near antiferromagnetic quantum critical point in Q1D conductors
Gorkov, L P
2005-01-01
In the frameworks of a nesting model for Q1D organic conductor at the antiferromagnetic (SDW) quantum critical point the first-order transition separates metallic state from the soliton phase having the periodic domain structure. The low temperature phase diagram also displays the 2nd-order transition line between the soliton and the uniformly gapped SDW phases. The results agree with the phase diagram of (TMTSF)$_2$PF$_6$ near critical pressure [T. Vuletic et al., Eur. Phys. J. B 25, 319 (2002)]. Detection of the 2nd-order transition line is discussed. We comment on superconductivity at lowest temperature.
Non-supersymmetric D1/D5, F/NS5 and closed string tachyon condensation
Lu, J. X.; Roy, Shibaji; Wang, Zhao-long; Wu, Rong-jun
2009-01-01
We construct the intersecting non-supersymmetric (non-susy) D1/D5 solution of type IIB string theory. While, as usual, the solution is charged under an electric two-form and an electric six-form gauge field, it also contains a non-susy chargeless (non-BPS) D0-brane. The S-dual of this solution is the non-susy F/NS5 solution. We show how these solutions nicely interpolate between the corresponding black (or non-extremal) solutions and the Kaluza-Klein (KK) "bubble of nothing"...
Thermal impedance at the interface of contacting bodies: 1-D examples solved by semi-derivatives
Directory of Open Access Journals (Sweden)
Hristov Jordan
2012-01-01
Full Text Available Simple 1-D semi-infinite heat conduction problems enable to demonstrate the potential of the fractional calculus in determination of transient thermal impedances of two bodies with different initial temperatures contacting at the interface ( x = 0 at t = 0 . The approach is purely analytic and uses only semi-derivatives (half-time and semi-integrals in the Riemann-Liouville sense. The example solved clearly reveals that the fractional calculus is more effective in calculation the thermal resistances than the entire domain solutions.
GNSS meteorology for severe weather - 1D, 2D and 3D solution
Rohm, Witold; Manning, Toby; Yuan, Yubin; Biadeglgne, Bertukan; Choy, Sue Lynn; Zhang, Kefei
2013-04-01
The variability of water vapour (WV) is strongly correlated with the formation, course and dissipation of the mesoscale convective storm systems, due to the large latent heat transfers in the evaporation/condensation process. Contrary to its importance WV space and time distribution remains under sampled in both domains, especially in sparsely populated countries such as Australia. GPS meteorology currently is a very important data source for meteorology, climatology and forecasting, due to the relatively dense network of receivers, operating in the unified reference frame. Point observations of troposphere delay (1D), integrated water vapour (1D), as well as maps of these parameters (2D) are highly sensitive to building up of high amount of water vapour in the troposphere, as well as storm passage. The Kalman filter based GNSS tomography is an emerging method of reconstructing dynamically changing wet refractivity fields (3D). All types of ground based GNSS products has solid scientific foundations and are routinely estimated by major GNSS processing centres with high accuracy and low latency (ie. EGVAP AC). The forthcoming challenge of for the analyse of GNSS meteorology estimates (1D, 2D and 3D) is developing a quantifiable method to predict as well as identify location, size and severity of mesoscale convective storm system. In the course of this research several spatial and temporal filter and indicators have been developed to aid in early detection, prediction and monitoring of severe weather events using all types of GNSS meteorology by-products estimates (1D, 2D and 3D). This research presents a case study based on the analysis of an extreme convective super cell storm in the Victorian region during March 2010 using GPS tomography. Integrated Perceptible Water readings collected from MOBS stations confirmed high time resolution as well as sensitivity to incoming severe weather. Another, special measure of Refractive Index adopted for GPS tomography wet refractivity profiles, shows excessive values as a response to supercell thunderstorm formation. Finally a 2D cross section mapping the lifecycle of this severe weather event concludes a correlation between the highly dynamic spatial and temporal changes of wet refractivity modelled using 4D GPS tomography with precipitation intensities measured using weather radars.
Relativistic mean-field theory study of proton halos in the 2s1d shell
International Nuclear Information System (INIS)
The properties of proton-rich nuclei in the 2s1d shell are investigated using the relativistic mean-field theory with the new TM2 and NL-SH interactions, which have been fitted carefully to the asymmetry energy, and therefore are well suited for studies of nuclei far off stability. The results of the calculations predict that there are one-proton halos in 26,27,28P and two-proton halos in 27,28,29S. (author)
Synthesis, Characterization, and Application of 1-D Cerium Oxide Nanomaterials: A Review
Directory of Open Access Journals (Sweden)
Kuen-Song Lin
2010-09-01
Full Text Available The present work provides a comprehensive overview of the recent progress of research work toward developing new one dimensional (1-D ceria (CeO2 nanomaterials. The review has been classified into three parts: the preparation procedures with identification of the existing different dimensional ceria nanomaterials, the formation mechanisms, and an analysis of their applications. From literature survey, it is inaugurated that the fundamental structures of the ceria nanomaterials constructively dominate their properties and applications. In addition, this work will also provide a perspective on the future technical trends for the development of different dimensional CeO2 nanomaterials.
KAM Tori for 1D Nonlinear Wave Equations with Periodic Boundary Conditions
Chierchia, Luigi; You, Jaingong
1999-01-01
In this paper, one-dimensional (1D) nonlinear wave equations $u_{tt} -u_{xx}+V(x)u =f(u)$, with periodic boundary conditions are considered; V is a periodic smooth or analytic function and the nonlinearity f is an analytic function vanishing together with its derivative at u=0. It is proved that for ``most'' potentials V(x), the above equation admits small-amplitude periodic or quasi-periodic solutions corresponding to finite dimensional invariant tori for an associated infi...
SO_0(1,d+1) Racah coefficients: Type I representations
Krasnov, Kirill; Louko, Jorma
2005-01-01
We use AdS/CFT inspired methods to study the Racah coefficients for type I representations of the Lorentz group SO_0(1,d+1) with d>1. For such representations (a multiple of) the Racah coefficient can be represented as an integral of a product of 6 bulk-to-bulk propagators over 4 copies of the hyperbolic space H_{d+1}. To compute the integrals we represent the bulk-to-bulk propagators in terms of bulk-to-boundary ones. The bulk integrals can be computed explicitly, and the b...
Simulation of Tunnel Junction in Cascade Solar Cell (GaAs/Ge Using AMPS-1D
Directory of Open Access Journals (Sweden)
Benmoussa Dennai
2014-11-01
Full Text Available The development of the tunnel junction interconnect was key the first two-terminal monolithic, multi-junction solar cell development. This paper describes simulation for the tunnel junction (GaAs between top cell (GaAs and bottom cell (Ge. This solar cell cascade was simulated when using one dimensional simulation program called analysis of microelectronic and photonic structures (AMPS-1D. In the simulation, the thickness of the tunnel junction layer was varied from 10 to 50 nm. By varying thickness of tunnel junction layer the simulated device performance was demonstrate in the form of current-voltage(I-V characteristics and quantum efficiency (QE.
Local correlations in the 1D Bose gas from a scaling limit of the XXZ chain
International Nuclear Information System (INIS)
We consider the K-body local correlations in the (repulsive) 1D Bose gas for general K, both at finite size and in the thermodynamic limit. Concerning the latter we develop a multiple integral formula which applies for arbitrary states of the system with a smooth distribution of Bethe roots, including the ground state and finite-temperature Gibbs states. In the cases K ? 4 we perform the explicit factorization of the multiple integral. In the case of K = 3 we obtain the recent result of Kormos et al, whereas our formula for K = 4 is new. Numerical results are presented as well
Seven--Superform Gauge Fields in N=1, D=10 Supergravity and Duality
Lechner, Kurt; Tonin, Mario
1995-01-01
We present a formulation of $N=1,D=10$ Supergravity--Super--Maxwell theory in superspace in which the graviphoton can be described by a 2--form $B_2$ or a 6--form $B_6$, the photon by a 1--form $A_1$ or a 7--form $A_7$ and the dilaton by a scalar $\\varphi$ or an 8--form $\\varphi_8$, the supercurvatures of these fields being related by duality. Duality interchanges Bianchi identities and equations of motion for each of the three couples of fields. This construction envisages ...
Evaluation of EMG signals Compression by JPEG 2000 called 1D
Directory of Open Access Journals (Sweden)
Ntsama Eloundou Pascal
2013-02-01
Full Text Available In this paper, we are conducting an evaluation the compression of electromyographic signals (EMG through of standard modified JPEG 2000 called 1D. We illustrate that; this method can also be used to compress EMG signals. The technique consists of cutting the signal into small segments or micro vectors. The EMG signal compression through this method aims at solving the problems of transmission and optimizes storage. A comparison of the results obtained with those of the literature shows a net improvement. The results obtained on real signals are presented in terms of the objective criteria ofevaluating performance.
Masala, Speranza; Zedda, Maria Antonietta; Cossu, Davide; Ripoli, Carlo; Palermo, Mario; Sechi, Leonardo A
2013-01-01
Our group has recently demonstrated that Mycobacterium avium subspecies paratuberculosis (MAP) infection significantly associates with T1D in Sardinian adult patients. Due to the potential role played by MAP in T1D pathogenesis, it is relevant to better characterize the prevalence of anti-MAP antibodies (Abs) in the Sardinian population, studying newly diagnosed T1D children. Therefore, we investigated the seroreactivity against epitopes derived from the ZnT8 autoantigen involved in children at T1D onset and their homologous sequences of the MAP3865c protein. Moreover, sera from all individuals were tested for the presence of Abs against: the corresponding ZnT8 C-terminal region, the MAP specific protein MptD, the T1D autoantigen GAD65 and the T1D unrelated Acetylcholine Receptor. The novel MAP3865c281-287 epitope emerges here as the major C-terminal epitope recognized. Intriguingly ZnT8186-194 immunodominant peptide was cross-reactive with the homologous sequences MAP3865c133-141, strengthening the hypothesis that MAP could be an environmental trigger of T1D through a molecular mimicry mechanism. All eight epitopes were recognized by circulating Abs in T1D children in comparison to healthy controls, suggesting that these Abs could be biomarkers of T1D. It would be relevant to investigate larger cohorts of children, followed over time, to elucidate whether Ab titers against these MAP/Znt8 epitopes wane after diagnosis. PMID:23696819
Scientific Electronic Library Online (English)
Salvatore, De Vincenzo.
2013-06-01
Full Text Available Apresentamos cálculos formais em 1D das derivadas com respeito ao tempo dos valores médios dos operadores da posição (x) e do momento linear (p) na representação de coordenadas. Chamamos esses cálculos formais porque não nos preocupamos com o tipo apropriado de funções sobre as quais devem atuar os [...] operadores (auto-adjuntos) envolvidos e alguns de seus produtos. Ao longo do artigo, examinamos e discutimos em detalhe as condições em que dois pares de relações que envolvem essas derivadas (que foram previamente publicadas) podem ser formalmente equivalentes. Mostramos que os termos de fronteira presentes em d{x}/dt e d{x}/dt podem ser escritos de modo que eles só dependem dos valores a tomados pela densidade de probabilidade, sua derivada espacial, a densidade de corrente de probabilidade e do potencial externo V = V(x).. Também mostramos que d(p)/dté igual a -dv /dx=(FQ)mais um termo de fronteira ((Fq = aQ/ax)é a força quântica e Q é o potencial quântico de Bohm). Verificamos que (fQ)é obtido simplesmente através do cálculo de uma certa quantidade em cada extremidade do intervalo contendo a partcula e subtraindo os dois resultados. Em alguns casos particulares essa quantidade é justamente proporcional ao integrando da assim chamada informação de Fisher. Notamos que (fQ )tem um papel significativo em situações em que a partcula é confinada a uma região, mesmo se V é zero dentro dessa região. Abstract in english We present formal 1D calculations of the time derivatives of the mean values of the position (x) and momentum (p) operators in the coordinate representation. We call these calculations formal because we do not care for the appropriate class of functions on which the involved (self-adjoint) operators [...] and some of its products must act. Throughout the paper, we examine and discuss in detail the conditions under which two pairs of relations involving these derivatives (which have been previously published) can be formally equivalent. We show that the boundary terms present in d{x}/dt and d{x}/dt can be written so that they only depend on the values taken there by the probability density, its spatial derivative, the probability current density and the external potential V= V9 (x) V = V(x). We also show that d(p)/dt is equal to -dv /dx=(FQ) plus a boundary term (Fq = aQ/ax)is the quantum force and Q is the Bohm's quantum potential). We verify that (fq) is simply obtained by evaluating a certain quantity on each end of the interval containing the particle and by subtracting the two results. That quantity is precisely proportional to the integrand of the so-called Fisher information in some particular cases. We have noted that fQ has a significant role in situations in which the particle is confined to a region, even if V is zero inside that region.
Cline, Susan D.; Lodeiro, M. Fernanda; Marnett, Lawrence J.; Cameron, Craig E.; Arnold, Jamie J.
2010-01-01
The biological aldehydes, malondialdehyde and base propenal, react with DNA to form a prevalent guanine adduct, M1dG. The exocyclic ring of M1dG opens to the acyclic N2-OPdG structure when paired with C but remains closed in single-stranded DNA or when mispaired with T. M1dG is a target of nucleotide excision repair (NER); however, NER is absent in mitochondria. An in vitro transcription system with purified human mitochondrial RNA polymerase (POLRMT) and transcription factors, mtTFA and mtTF...
Pharmacological challenge with a serotonin 1D agonist in alcohol dependence
Directory of Open Access Journals (Sweden)
Pienaar Willie
2005-08-01
Full Text Available 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. Administration of sumatriptan should therefore produce a craving for alcohol and the desire to drink. Methods Fifteen patients with alcohol dependence who had undergone detoxification were recruited. Sumatriptan (100 mg and placebo was administered in cross-over fashion on 2 separate days 72 hours apart. Both patients and raters were blind to all treatments. Patients were assessed on the following scales at -30, 0, 30, 90, 150 and 210 minutes: A 6-item scale designed to rate the patient's intention to drink; The Sensation Scale; a 13-item affect analog scale designed to rate the pattern and extent of emotional changes; and an 8-item scale designed to rate the patient's craving for alcohol Results No significant differences were found between the placebo and sumatriptan groups and no significant cross over effects were found. Conclusion The general lack of efficacy of sumatriptan in producing alcohol-like symptoms or a desire to drink alcohol may suggest that the 5HT1D receptor plays little role in the pathophysiology of alcoholism.
Can low-frequency breathers exist in a quasi-1D crystal?
Savin, A V; Manevitch, L I
2004-01-01
We investigate a quasi-1D crystal: 2D system of coupled linear chains of particles with strong intra-chain and weak inter-chain interactions. Nonlinear dynamics of one of these chains when the rest of them are fixed is reduced to the well known Frenkel-Kontorova (FK) model. Its continuum limit, sine-Gordon (sG) equation, predicts two types of soliton solutions: topological solitons and breathers. It is known that the quasi-1D topological solitons exist also in a 2D system of coupled chains and even in a 3D model of a polymer crystal. Numerical simulation shows that the breathers inherent to the FK model do not exist in the system of chains. The effect changes scenario of kink-antikink collision at small velocities: it always results only in intensive phonon radiation while kink-antikink recombination in the FK model results in long-living low-frequency sG breather creation. The reason of the difference is that the model of coupled chains catches 'acoustic' part of phonon spectrum of a crystal while the FK mod...
Quantum dynamics of O(1D)+D2 reaction: isotope and vibrational excitation effects
International Nuclear Information System (INIS)
The effect of initial vibrational excitation of the D2 molecule on the quantum dynamics of the O(1D)+D2 reaction is investigated as a function of collision energy. The potential energy surface of Dobbyn and Knowles (1997 Mol. Phys. 91 1107) and a time-independent quantum mechanical method based on hyperspherical coordinates have been adopted for the dynamics calculations. Results for elastic, inelastic, and reactive scattering over collision energies ranging from the ultracold to thermal regimes are reported for total angular momentum quantum number J = 0. Calculations show that the collisional outcome of the O(1D)+D2 reaction is not strongly influenced by the initial vibrational excitation of the D2 molecule similar to its H2 counterpart. A J-shifting approximation is used to calculate the initial state selected reactive rate coefficients over the temperature range T = 1 ? 500 K. The reactive rate coefficients for D2(v = 0) are found to be in excellent agreement with available experimental results. The temperature dependence of the kinetic isotope effect is also investigated and its value at room temperature is found to be in good agreement with available theoretical and experimental results. (paper)
Modelling magnetic exchange springs in 1D, 2D, and 3D
Bowden, G. J.; Martin, K. N.; Rainford, B. D.; de Groot, P. A. J.
2008-01-01
1D models of magnetic multilayers, with alternating hard and soft layers, are extended to 2D and 3D, and presented within a common framework of nearest neighbour interactions. Using 2D calculations, it is shown that the properties of magnetic exchange springs can be changed significantly by patterning the hard pinning layers. But, in certain cases the bending field BB is not significantly altered, even when half the pinning layer is removed. 3D calculations are used to probe the effects of defects on the properties of magnetic exchange springs, using epitaxial DyFe2/YFe2 superlattices as an example. It is shown that point defects such as Fe vacancies have little effect on the bending field transition. This is in marked contrast to the 1D model, where an Fe vacancy cuts the magnetic exchange spring into two. Finally, it is demonstrated that significant changes in the properties of magnetic exchange springs can be engineered, by placing rare-earth ions in the centre of the soft YFe2 springs. A new phenomenon, exchange spring collapse, is predicted.
Interfaces Supporting Surface Gap Soliton Ground States in the 1D Nonlinear Schroedinger Equation
Dohnal, Tomas; Plum, Michael; Reichel, Wolfgang
2012-01-01
We consider the problem of verifying the existence of $H^1$ ground states of the 1D nonlinear Schr\\"odinger equation for an interface of two periodic structures: $$-u" +V(x)u -\\lambda u = \\Gamma(x) |u|^{p-1}u \\ {on} \\R$$ with $V(x) = V_1(x), \\Gamma(x)=\\Gamma_1(x)$ for $x\\geq 0$ and $V(x) = V_2(x), \\Gamma(x)=\\Gamma_2(x)$ for $x1$. The article [T. Dohnal, M. Plum and W. Reichel, "Surface Gap Soliton Ground States for the Nonlinear Schr\\"odinger Equation," \\textit{Comm. Math. Phys.} \\textbf{308}, 511-542 (2011)] provides in the 1D case an existence criterion in the form of an integral inequality involving the linear potentials $V_{1},V_2$ and the Bloch waves of the operators $-\\tfrac{d^2}{dx^2}+V_{1,2}-\\lambda$. We choose here the classes of piecewise constant and piecewise linear potentials $V_{1,2}$ and check this criterion for a set of parameter values. In the piecewise constant case the Bloch waves are calculated explicitly and in the piecewise linear case verified enclosures of the Bloch waves are computed ...
Electrophoresis gel image processing and analysis using the KODAK 1D software.
Pizzonia, J
2001-06-01
The present article reports on the performance of the KODAK 1D Image Analysis Software for the acquisition of information from electrophoresis experiments and highlights the utility of several mathematical functions for subsequent image processing, analysis, and presentation. Digital images of Coomassie-stained polyacrylamide protein gels containing molecular weight standards and ethidium bromide stained agarose gels containing DNA mass standards are acquired using the KODAK Electrophoresis Documentation and Analysis System 290 (EDAS 290). The KODAK 1D software is used to optimize lane and band identification using features such as isomolecular weight lines. Mathematical functions for mass standard representation are presented, and two methods for estimation of unknown band mass are compared. Given the progressive transition of electrophoresis data acquisition and daily reporting in peer-reviewed journals to digital formats ranging from 8-bit systems such as EDAS 290 to more expensive 16-bit systems, the utility of algorithms such as Gaussian modeling, which can correct geometric aberrations such as clipping due to signal saturation common at lower bit depth levels, is discussed. Finally, image-processing tools that can facilitate image preparation for presentation are demonstrated. PMID:11414225
A New 2D-Transport, 1D-Diffusion Approximation of the Boltzmann Transport equation
Energy Technology Data Exchange (ETDEWEB)
Larsen, Edward
2013-06-17
The work performed in this project consisted of the derivation, implementation, and testing of a new, computationally advantageous approximation to the 3D Boltz- mann transport equation. The solution of the Boltzmann equation is the neutron flux in nuclear reactor cores and shields, but solving this equation is difficult and costly. The new “2D/1D” approximation takes advantage of a special geometric feature of typical 3D reactors to approximate the neutron transport physics in a specific (ax- ial) direction, but not in the other two (radial) directions. The resulting equation is much less expensive to solve computationally, and its solutions are expected to be sufficiently accurate for many practical problems. In this project we formulated the new equation, discretized it using standard methods, developed a stable itera- tion scheme for solving the equation, implemented the new numerical scheme in the MPACT code, and tested the method on several realistic problems. All the hoped- for features of this new approximation were seen. For large, difficult problems, the resulting 2D/1D solution is highly accurate, and is calculated about 100 times faster than a 3D discrete ordinates simulation.
Group decoupled multi-group pin power reconstruction utilizing nodal solution 1D flux profiles - 122
International Nuclear Information System (INIS)
A group decoupled direct fitting method is developed for multi-group pin power reconstruction, which avoids either the complication of constructing 2D analytic multi-group flux solution or any group coupled iteration. In addition to nodal volume and surface average fluxes and corner fluxes, transversely integrated 1D nodal solution flux profiles are also used. For each energy group, a two-dimensional expansion in nine polynomials and eight hyperbolic functions is used to perform a constrained least squared fit to the 1D intra-nodal flux solution profiles. The constraints are on the conservation of nodal volume and surface average fluxes and corner fluxes. The corner fluxes are determined thru the condition of corner currents conservation. An optional slowing down source improvement method is also developed to further enhance the solution if needed. Two test examples are shown with very good results. One problem is a four-group BWR mini-core with all control blades inserted and the other problem is the OECD seven-group MOX benchmark, C5G7. (authors)
International Nuclear Information System (INIS)
1-Silacyclobutane-1-d1 has been prepared and its infrared spectra have been analyzed. Several ring-puckering transitions have been observed in the far-infrared region and sum and difference bands have been observed in the Si-H stretching region. A ring-puckering potential function which simultaneously fits the data for the D0, d1, and d2 isotopic forms has been determined. Calculation of the wave functions for the d1 molecule shows that each of the lowest two very nearly degenergy states (nu = 0 and nu = 1) corresponds to only one distinct molecular conformation. Similarly, the nearly degenerate nu = 2 and nu = 3 states are primarily restricted to specific conformations. Doublets observed for the Si-H and Si-D stretching bands, corresponding to stretches from equitorial or axial positions, confirm these calculations. Model calculations on related systems demonstrate that both a sufficiently large barrier height and an asymmetry of the kinetic energy expansions are necessary for the conformational separation according to vibrational states. Although the reduced masses of the two conformers of 1-silacyclobutane-1-d1 differ by only 0.20%, this is enough to produce the observed conformational discrimination
Efficient Fast Multiplication Free Integer Transformation for the 1-D DCT of the H.265 Standard
Directory of Open Access Journals (Sweden)
Maher Rizkalla
2010-08-01
Full Text Available In this paper, efficient one-dimensional (1-D fast integer transform algorithms of the DCT matrix for the H.265 stan-dard is proposed. Based on the symmetric property of the integer transform matrix and the matrix operations, which denote the row/column permutations and the matrix decompositions, along with using the dyadic symmetry modification on the standard matrix, the efficient fast 1-D integer transform algorithms are developed. Therefore, the computational complexities of the proposed fast integer transform are smaller than those of the direct method. In addition to computational complexity reduction one of the proposed algorithms provides transformation quality improvement, while the other provides more computational complexity reduction while maintaining almost the same transformation quality. With lower complexity and better transformation quality, the first proposed fast algorithm is suitable to accelerate the quality-demanding video coding computations. On the other hand, with the significant lower complexity, the second proposed fast algorithm is suitable to accelerate the video coding computations.
Quasi-1D physics in metal-organic frameworks: MIL-47(V) from first principles
Jaeken, Jan W; De Baerdemacker, Stijn; Lejaeghere, Kurt; Van Speybroeck, Veronique
2014-01-01
Summary The geometric and electronic structure of the MIL-47(V) metal-organic framework (MOF) is investigated by using ab initio density functional theory (DFT) calculations. Special focus is placed on the relation between the spin configuration and the properties of the MOF. The ground state is found to be antiferromagnetic, with an equilibrium volume of 1554.70 Å3. The transition pressure of the pressure-induced large-pore-to-narrow-pore phase transition is calculated to be 82 MPa and 124 MPa for systems with ferromagnetic and antiferromagnetic chains, respectively. For a mixed system, the transition pressure is found to be a weighted average of the ferromagnetic and antiferromagnetic transition pressures. Mapping DFT energies onto a simple-spin Hamiltonian shows both the intra- and inter-chain coupling to be antiferromagnetic, with the latter coupling constant being two orders of magnitude smaller than the former, suggesting the MIL-47(V) to present quasi-1D behavior. The electronic structure of the different spin configurations is investigated and it shows that the band gap position varies strongly with the spin configuration. The valence and conduction bands show a clear V d-character. In addition, these bands are flat in directions orthogonal to VO6 chains, while showing dispersion along the the direction of the VO6 chains, similar as for other quasi-1D materials. PMID:25383285
The eigenvalue equation for a 1-D Hamilton function in deformation quantization
International Nuclear Information System (INIS)
The eigenvalue equation has been found for a Hamilton function in a form independent of the choice of a potential. This Letter proposes a modified Fedosov construction on a flat symplectic manifold. Necessary and sufficient conditions for solutions of an eigenvalue equation to be Wigner functions of pure states are presented. The 1-D harmonic oscillator eigenvalue equation in the coordinates time and energy is solved. A perturbation theory based on the variables time and energy is elaborated. -- Highlights: ? We propose a method of solution of the ?-genvalue equation for a 1-D Hamiltonian by the change of coordinates (q,p)?(time,energy). ? A covariant form of the ?-genvalue equation for Hamiltonian is presented. ? Continuity of a Wigner function of a pure state with respect to q and p has been proved. ? Three criteria for an arbitrary function to be a Wigner function of a pure state are presented and proved. ? A perturbation theory based on the variables time and energy is elaborated.
(7)Li in situ 1D NMR imaging of a lithium ion battery.
Klamor, S; Zick, K; Oerther, T; Schappacher, F M; Winter, M; Brunklaus, G
2015-01-28
The spatial distribution of charge carriers in lithium ion batteries during current flow is of fundamental interest for a detailed understanding of transport properties and the development of strategies for future improvements of the electrolyte-electrode interface behaviour. In this work we explored the potential of (7)Li 1D in situ NMR imaging for the identification of concentration gradients under constant current load in a battery cell. An electrochemical cell based on PTFE body and a stack of glass microfiber discs that are soaked with a technically relevant electrolyte suitable for high-temperature application and squeezed between a Li metal and a nano-Si-graphite composite electrode was assembled to acquire (7)Li 1D in situ NMR profiles with an improved NMR pulse sequence as function of time and state of charge, thereby visualizing the course of ion concentration during charge and discharge. Surface localized changes of Li concentration were attributed to processes such as solid electrolyte interphase formation or full lithiation of the composite electrode. The method allows the extraction of lithium ion transport properties. PMID:25578436
1D self-assembly of chemisorbed thymine on Cu(110) driven by dispersion forces
Temprano, I.; Thomas, G.; Haq, S.; Dyer, M. S.; Latter, E. G.; Darling, G. R.; Uvdal, P.; Raval, R.
2015-03-01
Adsorption of thymine on a defined Cu(110) surface was studied using reflection-absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and scanning tunnelling microscopy (STM). In addition, density functional theory (DFT) calculations were undertaken in order to further understand the energetics of adsorption and self-assembly. The combination of RAIRS, TPD, and DFT results indicates that an upright, three-point-bonded adsorption configuration is adopted by the deprotonated thymine at room temperature. DFT calculations show that the upright configuration adopted by individual molecules arises as a direct result of strong O-Cu and N-Cu bonds between the molecule and the surface. STM data reveal that this upright thymine motif self-assembles into 1D chains, which are surprisingly oriented along the open-packed [001] direction of the metal surface and orthogonal to the alignment of the functional groups that are normally implicated in H-bonding interactions. DFT modelling of this system reveals that the molecular organisation is actually driven by dispersion interactions, which cause a slight tilt of the molecule and provide the major driving force for assembly into dimers and 1D chains. The relative orientations and distances of neighbouring molecules are amenable for ?-? stacking, suggesting that this is an important contributor in the self-assembly process.
Quasinormal modes of (Anti-)de Sitter black holes in the 1/D expansion
Emparan, Roberto; Tanabe, Kentaro
2015-01-01
We use the inverse-dimensional expansion to compute analytically the frequencies of a set of quasinormal modes of static black holes of Einstein-(Anti-)de Sitter gravity, including the cases of spherical, planar or hyperbolic horizons. The modes we study are decoupled modes localized in the near-horizon region, which are the ones that capture physics peculiar to each black hole (such as their instabilities), and which in large black holes contain hydrodynamic behavior. Our results also give the unstable Gregory-Laflamme frequencies of Ricci-flat black branes to two orders higher in 1/D than previous calculations. We discuss the limits on the accuracy of these results due to the asymptotic but not convergent character of the 1/D expansion, which is due to the violation of the decoupling condition at finite D. Finally, we compare the frequencies for AdS black branes to calculations in the hydrodynamic expansion in powers of the momentum k. Our results extend up to k^9 for the sound mode and to k^8 for the shear...
Calibration of Axisymmetric and Quasi-1D Solvers for High Enthalpy Nozzles
Papadopoulos, P. E.; Gochberg, L. A.; Tokarcik-Polsky, S.; Venkatapathy, E.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)
1994-01-01
The proposed paper will present a numerical investigation of the flow characteristics and boundary layer development in the nozzles of high enthalpy shock tunnel facilities used for hypersonic propulsion testing. The computed flow will be validated against existing experimental data. Pitot pressure data obtained at the entrance of the test cabin will be used to validate the numerical simulations. It is necessary to accurately model the facility nozzles in order to characterize the test article flow conditions. Initially the axisymmetric nozzle flow will be computed using a Navier Stokes solver for a range of reservoir conditions. The calculated solutions will be compared and calibrated against available experimental data from the DLR HEG piston-driven shock tunnel and the 16-inch shock tunnel at NASA Ames Research Center. The Reynolds number is assumed to be high enough at the throat that the boundary layer flow is assumed turbulent at this point downstream. The real gas affects will be examined. In high Mach number facilities the boundary layer is thick. Attempts will be made to correlate the boundary layer displacement thickness. The displacement thickness correlation will be used to calibrate the quasi-1D codes NENZF and LSENS in order to provide fast and efficient tools of characterizing the facility nozzles. The calibrated quasi-1D codes will be implemented to study the effects of chemistry and the flow condition variations at the test section due to small variations in the driver gas conditions.
Bischoff, Joerg
2010-01-01
The diffraction computation of crossed gratings is very slow compared with that of line-space gratings of the same size when using a modal method such as rigorous coupled wave analysis (RCWA) or the Chandezon coordinate transformation method. It is well known that the main bottleneck in terms of computation speed is the solution of an eigenproblem for each RCWA slice or interface in the case of the C-method. Even if the crossed grating contains layers that are periodic only in one direction, usually the full 2D problem has to be solved for this layer in order to connect it to the full system solution. In this paper, a computation schema is presented that takes advantage of the 1D periodicity of layers inside a 2D multilayer grating. This results in a considerable acceleration of the formulation and solution of the eigenproblem for these layers. With this new computation schema the total time required for 1D layers in a 2D layer stack can be greatly reduced. PMID:20035311
NOKIN1D: one-dimensional neutron kinetics based on a nodal collocation method
Verdú, G.; Ginestar, D.; Miró, R.; Jambrina, A.; Barrachina, T.; Soler, Amparo; Concejal, Alberto
2014-06-01
The TRAC-BF1 one-dimensional kinetic model is a formulation of the neutron diffusion equation in the two energy groups' approximation, based on the analytical nodal method (ANM). The advantage compared with a zero-dimensional kinetic model is that the axial power profile may vary with time due to thermal-hydraulic parameter changes and/or actions of the control systems but at has the disadvantages that in unusual situations it fails to converge. The nodal collocation method developed for the neutron diffusion equation and applied to the kinetics resolution of TRAC-BF1 thermal-hydraulics, is an adaptation of the traditional collocation methods for the discretization of partial differential equations, based on the development of the solution as a linear combination of analytical functions. It has chosen to use a nodal collocation method based on a development of Legendre polynomials of neutron fluxes in each cell. The qualification is carried out by the analysis of the turbine trip transient from the NEA benchmark in Peach Bottom NPP using both the original 1D kinetics implemented in TRAC-BF1 and the 1D nodal collocation method.
Fernandes, Ana Clara; Uytterhoeven, Valerie; Kuenen, Sabine; Wang, Yu-Chun; Slabbaert, Jan R; Swerts, Jef; Kasprowicz, Jaroslaw; Aerts, Stein; Verstreken, Patrik
2014-11-24
Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans. PMID:25422373
IDENT 1D - a novel software tool for an easy identification of material constitutive parameters
International Nuclear Information System (INIS)
Non-linear finite element computations make use of very sophisticated constitutive equations for the description of materials behaviour. The first difficulty encountered by potential users is the gap existing between raw material characterisation on uniaxial specimens and the knowledge of the required equation's parameters. There are very few softwares for this particular task. IDENT 1D is a special software developed under Matlab language in our laboratory, which is able to provide a complete optimised parameters set for implemented models. The originality of IDENT 1D is that no initial estimation of the material parameters is requested of the user. Two main examples are described in this article: the LEMAITRE AND CHABOCHE (1990) creep law coupled with damage and a non unified cyclic law proposed by CONTESTI AND CAILLETAUD (1989) with a separation of plastic and viscous strain terms which is called DDI model. For both laws, the identification method is completely described. Each method is then applied to a set of experimental data. In both cases, the results of the parameters identification show a very good agreement with experimental data. (orig.)
Ident 1D - a novel software tool for an easy identification of material constitutive parameters
International Nuclear Information System (INIS)
Non-linear finite element computations make use of very sophisticated constitutive equations for description of materials behaviour. The first difficulty encountered by potential users is the gap existing between raw material characterisation on uniaxial specimens and the knowledge of the required equation's parameters. There are very few software for this particular task. IDENT 1D is a special software developed under Matlab language in our laboratory, which is able to provide a complete optimised parameters set for implemented models. The originality of IDENT 1D is that no initial estimation of the material parameters is requested of the user. Two main examples are described in this article: the Lemaitre and Chaboche creep law coupled with damage and a non unified cyclic law proposed by Contesti and Cailletaud with a separation of plastic and viscous strain terms which is called DDI model. For both laws, the identification method is completely described. Each method is then applied to a set of experimental data. In both cases, the results of the parameters identification show a very good agreement with experimental data. (authors)
Scale-Invariant Local Descriptor for Event Recognition in 1D Sensor Signals
Xie, Jierui
2011-01-01
In this paper, we introduce a shape-based, time-scale invariant feature descriptor for 1-D sensor signals. The time-scale invariance of the feature allows us to use feature from one training event to describe events of the same semantic class which may take place over varying time scales such as walking slow and walking fast. Therefore it requires less training set. The descriptor takes advantage of the invariant location detection in the scale space theory and employs a high level shape encoding scheme to capture invariant local features of events. Based on this descriptor, a scale-invariant classifier with "R" metric (SIC-R) is designed to recognize multi-scale events of human activities. The R metric combines the number of matches of keypoint in scale space with the Dynamic Time Warping score. SICR is tested on various types of 1-D sensors data from passive infrared, accelerometer and seismic sensors with more than 90% classification accuracy.
Analysis of a 1D incompressible two-fluid model including artificial diffusion
Holmas, H.; Sira, T.; Nordsveen, M.; Langtangen, H. P.; Schulkes, R.
2008-08-01
This article examines a 1D incompressible two-fluid model including artificial tensor diffusion. The aim is to obtain a formulation that provides convergent numerical solutions for all flow conditions within the stratified and the stratified wavy flow regime. With appropriate simplifications, the two-fluid model reduces to one momentum balance, one mass conservation and two algebraic equations. It has previously been established that a formulation that is well posed in possessing exclusively real characteristics can be obtained by including an axial diffusion term in the momentum balance. In this article, however, we demonstrate that this is not sufficient to obtain a system suitable for numerical simulations. Although the unbounded growth rates of the standard two-fluid model are eliminated, linear stability theory predicts that infinitesimal wavelengths still experience finite growth. This entails that grid refinement always will result in new unstable wavelengths being resolved. On the other hand, if artificial axial diffusion is added to both the mass and the momentum equations as suggested here, a cut-off wavelength is established below which all wavelengths are stable. Thus, a numerically converging model is formed, which retains the long-wavelength properties of the standard two-fluid model. The conclusions of the mathematical analysis are substantiated by numerical simulations of 1D gravity waves.
Energy Technology Data Exchange (ETDEWEB)
Boisbouvier, Jerome; Bryce, David L.; O' Neil-Cabello, Erin [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (United States); Nikonowicz, Edward P. [Rice University, Department of Biochemistry and Cell Biology (United States); Bax, Ad [Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (United States)], E-mail: bax@nih.gov
2004-11-15
New methods are described for accurate measurement of multiple residual dipolar couplings in nucleic acid bases. The methods use TROSY-type pulse sequences for optimizing resolution and sensitivity, and rely on the E.COSY principle to measure the relatively small two-bond {sup 2}D{sub CH} couplings at high precision. Measurements are demonstrated for a 24-nt stem-loop RNA sequence, uniformly enriched in {sup 13}C, and aligned in Pf1. The recently described pseudo-3D method is used to provide homonuclear {sup 1}H-{sup 1}H decoupling, which minimizes cross-correlation effects and optimizes resolution. Up to seven {sup 1}H-{sup 13}C and {sup 13}C-{sup 13}C couplings are measured for pyrimidines (U and C), including {sup 1}D{sub C5H5}, {sup 1}D{sub C6H6}, {sup 2}D{sub C5H6}, {sup 2}D{sub C6H5}, {sup 1}D{sub C5C4}, {sup 1}D{sub C5C6}, and {sup 2}D{sub C4H5}. For adenine, four base couplings ({sup 1}D{sub C2H2}, {sup 1}D{sub C8H8}, {sup 1}D{sub C4C5}, and {sup 1}D{sub C5C6}) are readily measured whereas for guanine only three couplings are accessible at high relative accuracy ({sup 1}D{sub C8H8}, {sup 1}D{sub C4C5}, and {sup 1}D{sub C5C6}). Only three dipolar couplings are linearly independent in planar structures such as nucleic acid bases, permitting cross validation of the data and evaluation of their accuracies. For the vast majority of dipolar couplings, the error is found to be less than {+-}3% of their possible range, indicating that the measurement accuracy is not limiting when using these couplings as restraints in structure calculations. Reported isotropic values of the one- and two-bond J couplings cluster very tightly for each type of nucleotide.
The JPL Benchmarking Suite for Scalar and Vector 1D Radiative Transfer in Scattering Atmospheres
Davis, A. B.; Kalashnikova, O. V.; Diner, D. J.; Garay, M. J.; Lo, M. W.; Martonchik, J. V.; Natraj, V.; Sanghavi, S.; Seidel, F. C.; West, R. A.; Xu, F.; Zhai, P.; Kokhanovsky, A. A.
2012-12-01
Future aerosol/cloud remote sensing missions by NASA, ESA, JAXA and others will have stringent accuracy requirements for cloud and aerosol property retrievals in order to meet their science goals, themselves driven by demands for improved global and regional climate modeling as well as air quality monitoring. At the core of physics-based retrieval algorithms is a forward radiative transfer model (RTM) that determines the ultimate limitations of the retrieval scheme by making assumptions about atmospheric structure and particle microphysics, hence optics. One such assumption is that the atmosphere is strictly uniform in the horizontal plane, i.e., a "1D" RTM is used. Cloud remote sensing is particularly vulnerable to this assumption, and the resulting forward model error is associated with "3D RT" effects. Other such assumptions relevant to aerosol remote sensing are that it is often assumed to be confined to the boundary layer (e.g., 0-2 km) when in reality the particulates can be lofted, or that they are spherical when in reality they can take many shapes. These qualitative issues of forward RTM fidelity with respect to nature are preceded by quantitative questions about numerical accuracy and precision as well as computational efficiency, including whether or not the RTM is linearized (provides Jacobians as well as radiances, as required for optimization-based retrievals). A rationalized 1D RTM benchmarking framework has been developed at JPL to guide investments in forward model development that will lead to the best combinations of accuracy/precision, efficiency and fidelity from a programmatic perspective. The present focus is on aerosols. A small number of particle types have been carefully selected to be both representative of what is in nature and computationally challenging to accommodate in a typical 1D RTM implemented in code. Thus realistic particles with smooth and forward-peaked phase functions are present, spherical or not, with or without variability in the backscattering region, with or without absorption. A few different surface types were also selected: Lambertian or not; if non-Lambertian, polarizing or not. Finally, the aerosols can be in the boundary layer (0-2 km) or lofted (3-5 km); either way, they are assumed to be uniform within their layer but mixed continuously with an exponential background of Rayleigh scattering with optical depths that exceed the aerosol's or not. The golden standard is a new Monte Carlo 1D RTM, either vector or scalar (i.e., polarized or not), with guarantied accuracy, controlled precision and high fidelity. It has flexible output, and can thus be customized for a specific instrument or instrument concept. It makes no claim of efficiency but, in sharp contrast with its deterministic counterparts, there is no strict need for any kind of discretization in angular or spatial quadratures; nor is there any need for forward peak truncation procedures when the scattering particles have large size parameters and efficiency is of the essence. We will present results that document the performance of a wide variety of deterministic 1D RTMs used at JPL, and one guest RTM from Bremen (SCIATRAN) that has been used in a recent benchmarking exercise with a much more limited scope. Plans to release the benchmarking data and Monte Carlo code to the broader remote sensing community will be discussed.
International Nuclear Information System (INIS)
The status of radionuclide generators for chemical research and applications related to the life sciences and biomedical research are reviewed. Emphasis is placed upon convenient, efficient and rapid separation of short-lived daughter radionuclides in a chemical form suitable for use without further chemical manipulation. The focus is on the production of the parent, the radiochemistry associated with processing the parent and daughter, the selection and the characteristic separation methods, and yields. Quality control considerations are briefly noted. The scope of this review includes selected references to applications of radionuclide generators in radiopharmaceutical chemistry, and the life sciences, particularly in diagnostic and therapeutic medicine. The 99Mo-sup(99m)Tc generator was excluded. 202 references are cited. (orig.)
3D velocity mapping: dynamics of the reaction O(1D)+N2O?2NO photoinitiated in the (N2O)2 dimer
International Nuclear Information System (INIS)
3D velocity mapping allows state specific characterization of full three dimensional velocity distributions of reaction products following resonance-enhanced multi-photon ionization (REMPI). 3D resolution is achieved by using a time-of-flight (TOF) spectrometer equipped with a two-dimensional delay line behind a micro channel plate stack which simultaneously returns impact position and time of the selected reaction product. Inserting an Einzel lens into the TOF spectrometer allows to map the product velocity and to get rid of image distortion due to the unavoidable length of the ionization laser focus. The technique has been used to investigate the reaction of O(1D) with N2O in the (N2O)2 dimer. O(1D) is generated by photodissociation of N2O using an ArF excimer laser. The reaction yields two NO molecules which are subsequently ionized via a (1+1)-REMPI process by a dye laser. We have measured selected quantum state specific 3D velocity distributions of the NO product as well as spectra for several vibrational states (v ? 7) of the electronic ground state X(2??). The rotational temperature is low, in agreement with earlier investigations of the cluster reaction, but in striking contrast to the free collision
Scandalously Parallelizable Mesh Generation
Bortz, David
2011-01-01
We propose a novel approach which employs random sampling to generate an accurate non-uniform mesh for numerically solving Partial Differential Equation Boundary Value Problems (PDE-BVP's). From a uniform probability distribution U over a 1D domain, we sample M discretizations of size N where M>>N. The statistical moments of the solutions to a given BVP on each of the M ultra-sparse meshes provide insight into identifying highly accurate non-uniform meshes. Essentially, we use the pointwise mean and variance of the coarse-grid solutions to construct a mapping Q(x) from uniformly to non-uniformly spaced mesh-points. The error convergence properties of the approximate solution to the PDE-BVP on the non-uniform mesh are superior to a uniform mesh for a certain class of BVP's. In particular, the method works well for BVP's with locally non-smooth solutions. We present a framework for studying the sampled sparse-mesh solutions and provide numerical evidence for the utility of this approach as applied to a set of e...
Navon, M. I.; Stefanescu, R.; Fuelberg, H. E.; Marchand, M.
2012-12-01
NASA's launch of the GOES-R Lightning Mapper (GLM) in 2015 will provide continuous, full disc, high resolution total lightning (IC + CG) data. The data will be available at a horizontal resolution of approximately 9 km. Compared to other types of data, the assimilation of lightning data into operational numerical models has received relatively little attention. Previous efforts of lightning assimilation mostly have employed nudging. This paper will describe the implementation of 1D+3D/4D Var assimilation schemes of existing ground-based WTLN (Worldwide Total Lightning Network) lightning observations using non-linear observation operators in the incremental WRFDA system. To mimic the expected output of GLM, the WTLN data were used to generate lightning super-observations characterized by flash rates/81 km2/20 min. A major difficulty associated with variational approaches is the complexity of the observation operator that defines the model equivalent of lightning. We use Convective Available Potential Energy (CAPE) as a proxy between lightning data and model variables. This operator is highly nonlinear. Marecal and Mahfouf (2003) have shown that nonlinearities can prevent direct assimilation of rainfall rates in the ECMWF 4D-VAR (using the incremental formulation proposed by Courtier et al. (1994)) from being successful. Using data from the 2011 Tuscaloosa, AL tornado outbreak, we have proved that the direct assimilation of lightning data into the WRF 3D/4D - Var systems is limited due to this incremental approach. Severe threshold limits must be imposed on the innovation vectors to obtain an improved analysis. We have implemented 1D+3D/4D Var schemes to assimilate lightning observations into the WRF model. Their use avoids innovation vector constrains from preventing the inclusion of a greater number of lightning observations Their use also minimizes the problem that nonlinearities in the moist convective scheme can introduce discontinuities in the cost function between inner and outer loops of the incremental 3-D/4-D VAR minimization. The first part of this paper will describe the methodology and performance analysis of the 1D-Var retrieval scheme that adjusts the WRF temperature profiles closer to an observed value as in Mahfouf et al. (2005). The second part will show the positive impact of these 1D-Var pseudo - temperature observations on both model 3D/4D-Var WRF analyses and short-range forecasts for three cases - the Tuscaloosa tornado outbreak (April 27, 2011) with intense but localized lightning, a second severe storm outbreak with more widespread but less intense lightning (June 27, 2011), and a northeaster containing much less lightning.
International Nuclear Information System (INIS)
This invention relates to methods and apparatus for expelling occluded gases from permanently magnetizable materials, and more particularly, to a neutron generator in which one of the electrodes in the ion source also produces a permanent magnetic field, and the like
International Nuclear Information System (INIS)
The object of the invention is to reduce the risks of solids in the steam generator being deposited where they might lead to corrosion. Diagrams and full details are given. A steam generator is described for use in generating steam by indirect heat exchange between a primary fluid and water, the generator comprising a bundle of U-tubes extending between primary fluid inlet and outlet headers and located within a shell or casing, wherein a perforated blow-down tube is provided adjacent to the top of at least the primary fluid outlet header, preferably each header. Through the blow-down tube a continuous purge of water can be removed to create fluid flow over the top surface of the headers and so flush deposited solids to the blow-down tubes where they will be ejected. The blow-down tubes can also provide an intermittent wash for the top surfaces of the headers. Various other aspects of the invention further prevent or reduce the dangerous deposition of solids. (UK)
Le, Yuan; Glaser, Kevin; Romano, Anthony; Manduca, Armando; Lai, Jinping; Roberts, Lewis R.; Primak, Svetlana; Ehman, Richard; Felmlee, Joel P.
2006-05-01
A new method is evaluated for using 1D MR elastography to monitor focused ultrasound surgery (FUS) treatment in real time. A MRI compatible ultrasound system was used and 29 pieces of ex vivo porcine tissue and 2 nude mice breast tumor xenoplant were evaluated for the change of shear wave displacement measured at the focus of pulsed ultrasound. This study shows the potential of 1D MR elastography to be used for FUS treatment monitoring.
Potential role of TBC1D4 in enhanced post-exercise insulin action in human skeletal muscle
DEFF Research Database (Denmark)
Treebak, Jonas Thue; FrØsig, Christian
2009-01-01
AIMS/HYPOTHESIS: TBC1 domain family, member 4 (TBC1D4; also known as AS160) is a cellular signalling intermediate to glucose transport regulated by insulin-dependent and -independent mechanisms. Skeletal muscle insulin sensitivity is increased after acute exercise by an unknown mechanism that does not involve modulation at proximal insulin signalling intermediates. We hypothesised that signalling through TBC1D4 is involved in this effect of exercise as it is a common signalling element for insulin and exercise. METHODS: Insulin-regulated glucose metabolism was evaluated in 12 healthy moderately trained young men 4 h after one-legged exercise at basal and during a euglycaemic-hyperinsulinaemic clamp. Vastus lateralis biopsies were taken before and immediately after the clamp. RESULTS: Insulin stimulation increased glucose uptake in both legs, with greater effects (~80%, p < 0.01) in the previously exercised leg. TBC1D4 phosphorylation, assessed using the phospho-AKT (protein kinase B)substrate antibody and phospho- and site-specific antibodies targeting six phosphorylation sites on TBC1D4, increased at similar degrees to insulin stimulation in the previously exercised and rested legs (p < 0.01). However, TBC1D4 phosphorylation on Ser-318, Ser-341, Ser-588 and Ser-751 was higher in the previously exercised leg, both in the absence and in the presence of insulin (p < 0.01; Ser-588, p = 0.09; observed power = 0.39). 14-3-3 binding capacity for TBC1D4 increased equally (p < 0.01) in both legs during insulin stimulation. CONCLUSION/INTERPRETATION: We provide evidence for site-specific phosphorylation of TBC1D4 in human skeletal muscle in response to physiological hyperinsulinaemia. The data support the idea that TBC1D4 is a nexus for insulin- and exercise-responsive signals that may mediate increased insulin action after exercise.
Genome Sequence of Bovine Viral Diarrhea Virus Strain 10JJ-SKR, Belonging to Genotype 1d
Joo, Soo-kyung; Lim, Seong-in; Jeoung, Hye-young; Song, Jae-young; Oem, Jae-ku; Mun, Seong-hwan; An, Dong-jun
2013-01-01
Here, we report the complete genome sequence of a bovine viral diarrhea virus (BVDV) belonging to genotype 1d, strain 10JJ-SKR, which was isolated from cattle. The complete genome is 12,267 nucleotides (nt) in length, with a single large open reading frame. This is the first report of a BVDV belonging to genotype 1d and will enable further study of the molecular and epidemiological characteristics of this virus.
Genome Sequence of Bovine Viral Diarrhea Virus Strain 10JJ-SKR, Belonging to Genotype 1d
Joo, Soo-Kyung; Lim, Seong-In; Jeoung, Hye-Young; Song, Jae-Young; Oem, Jae-Ku; Mun, Seong-Hwan
2013-01-01
Here, we report the complete genome sequence of a bovine viral diarrhea virus (BVDV) belonging to genotype 1d, strain 10JJ-SKR, which was isolated from cattle. The complete genome is 12,267 nucleotides (nt) in length, with a single large open reading frame. This is the first report of a BVDV belonging to genotype 1d and will enable further study of the molecular and epidemiological characteristics of this virus. PMID:23929474
Ahn, Andrew H; Basbaum, Allan I
2006-08-01
The anti-migraine action of "triptan" drugs involves the activation of serotonin subtype 1D (5-HT1D) receptors expressed on "pain-responsive" trigeminal primary afferents. In the central terminals of these nociceptors, the receptor is concentrated on peptidergic dense core vesicles (DCVs) and is notably absent from the plasma membrane. Based on this arrangement, we hypothesized that in the resting state the receptor is not available for binding by a triptan, but that noxious stimulation of these afferents could trigger vesicular release of DCVs, thus externalizing the receptor. Here we report that within 5 min of an acute mechanical stimulus to the hindpaw of the rat, there is a significant increase of 5-HT1D-immunoreactivity (IR) in the ipsilateral dorsal horn of the spinal cord. We suggest that these rapid immunohistochemical changes reflect redistribution of sequestered receptor to the plasma membrane, where it is more readily detected. We also observed divergent changes in 5-HT1D-IR in inflammatory and nerve-injury models of persistent pain, occurring at least in part through the regulation of 5-HT1D-receptor gene expression. Finally, we found that 5-HT1D-IR is unchanged in the spinal cord dorsal horn of mice with a deletion of the gene encoding the neuropeptide substance P. This result differs from that reported for the partial differential-opioid receptor, which is also sorted to DCVs, but is greatly reduced in preprotachykinin mutant mice. We suggest that a "pain"-triggered regulation of 5-HT1D-receptor expression underlies the effectiveness of triptans for the treatment of migraine. Moreover, the widespread expression of 5-HT1D receptor in somatic nociceptive afferents suggests that triptans could, in certain circumstances, treat pain in nontrigeminal regions of the body. PMID:16899728
Tonoli, Cajsa; Heyman, Elsa; Buyse, Luk; Roelands, Bart; Piacentini, Maria Francesca; Bailey, Stephen; Pattyn, Nathalie; Berthoin, Serge; Meeusen, Romain
2015-01-01
Exercise is known to have beneficial effects on cognitive function. This effect is greatly favored by an exercise-induced increase in neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1), especially with high-intensity exercises (HIE). As a complication of type 1 diabetes (T1D), a cognitive decline may occur, mostly ascribed to hypoglycaemia and chronic hyperglycaemia. Therefore, the purpose of this study was to examine the effects of acute HIE on cognitive function and neurotrophins in T1D and matched controls. Ten trained T1D (8 males, 2 females) participants and their matched (by age, sex, fitness level) controls were evaluated on 2 occasions after familiarization: a maximal test to exhaustion and an HIE bout (10 intervals of 60 s at 90% of their maximal wattage followed by 60 s at 50 W). Cognitive tests and analyses of serum BDNF, IGF-1, and free insulin were performed before and after HIE and following 30 min of recovery. At baseline, cognitive performance was better in the controls compared with the T1D participants (p cognitive performance were detected. BDNF levels were significantly higher and IGF-1 levels were significantly lower in T1D compared with the control group (p < 0.05) at all time points. Exercise increased BDNF and IGF-1 levels in a comparable percentage in both groups (p < 0.05). In conclusion, although resting levels of serum BDNF and IGF-1 were altered by T1D, comparable increasing effects on BDNF and IGF-1 in T1D and healthy participants were found. Therefore, regularly repeating acute HIE could be a promising strategy for brain health in T1D. PMID:25525862
The medicinal chemistry of aryl triflates : as applied to 5-HT1A and 5-HT1D receptor ligands
Barf, Tjeerd Andries
1996-01-01
The medical chemistry of aryl triflates. As applied to 5-HT1d receptor ligands. Korte beschrijving: Het onderzoek in dit proefschrift beschrijft de synthese en de farmacologische evaluatie van nieuwe 5-HT1a en 5-HT1D receptor liganden, met potentiële therapeutische toepassingen in bovengenoemde afwijkingen. De structuur-affiniteit relaties (SAFIR) en structuur-activiteit relaties (SAR) staan centraal maar er wordt ook aandacht besteed aan de biologische beschikbaarheid van de nieuwe ver...
Cline, Susan D; Lodeiro, M Fernanda; Marnett, Lawrence J; Cameron, Craig E; Arnold, Jamie J
2010-11-01
The biological aldehydes, malondialdehyde and base propenal, react with DNA to form a prevalent guanine adduct, M(1)dG. The exocyclic ring of M(1)dG opens to the acyclic N(2)-OPdG structure when paired with C but remains closed in single-stranded DNA or when mispaired with T. M(1)dG is a target of nucleotide excision repair (NER); however, NER is absent in mitochondria. An in vitro transcription system with purified human mitochondrial RNA polymerase (POLRMT) and transcription factors, mtTFA and mtTFB2, was used to determine the effect of M(1)dG on POLRMT elongation. DNA templates contained a single adduct opposite either C or T downstream of either the light-strand (LSP) or heavy-strand (HSP1) promoter for POLRMT. M(1)dG in the transcribed strand arrested 60-90% POLRMT elongation complexes with greater arrest by the adduct when opposite T. POLRMT was more sensitive to N(2)-OPdG and M(1)dG after initiation at LSP, which suggests promoter-specific differences in the function of POLRMT complexes. A closed-ring analog of M(1)dG, PdG, blocked ?95% of transcripts originating from either promoter regardless of base pairing, and the transcripts remained associated with POLRMT complexes after stalling at the adduct. This work suggests that persistent M(1)dG adducts in mitochondrial DNA hinder the transcription of mitochondrial genes. PMID:20671026
Enjin, Anders; Lea?o, Katarina E.; Mikulovic, Sanja; Le Merre, Pierre; Tourtellotte, Warren G.; Kullander, Klas
2012-01-01
Gamma motor neurons (MNs), the efferent component of the fusimotor system, regulate muscle spindle sensitivity. Muscle spindle sensory feedback is required for proprioception that includes sensing the relative position of neighboring body parts and appropriately adjust the employed strength in a movement. The lack of a single and specific genetic marker has long hampered functional and developmental studies of gamma MNs. Here we show that the serotonin receptor 1d (5-ht1d) is specifically exp...
Universal scheme of minimal reduction of usual and dual N=1,D=10 supergravity to the Minkowsky space
Zyablyuk, K. N.
1996-01-01
The reduction from N=1, D=10 to N=4, D=4 supergravity with the Yang-Mills matter is considered. For this purpose a set of constraints is imposed in order to exclude six additional abelian matter multiplets and conserve the supersymmetry. We consider both the cases of usual and dual N=1, D=10 supergravity using the superspace approach. Also the effective potential of the deriving theory is written.
1D and 2D photonic crystal nanocavities for semiconductor cavity QED
Richards, Benjamin C.
The topic of this dissertation is photonic crystal nanocavities for semiconductor cavity quantum electrodynamics. For the purposes of this study, these nanocavities may be one dimensional (1D) or two dimensional (2D) in design. The 2D devices are active and contain embedded InAs quantum dots (QDs), whereas the 1D devices are passive and contain no active emitters. The 2D photonic crystal nanocavities are fabricated in a slab of GaAs with a single layer of InAs QDs embedded in the slab. When a cavity mode substantially overlaps the QD ensemble, the dots affect the linewidths of the observed modes, leading to broadening of the linewidth at low excitation powers due to absorption and narrowing of the linewidths at high excitation powers due to gain when the QD ensemble absorption is saturated. We observe lasing from a few QDs in such a nanocavity. A technique is discussed with allows us to tune the resonance wavelength of a nanocavity by condensation of an inert gas onto the sample, which is held at cryogenic temperatures. The structural quality at the interfaces of epitaxially grown semiconductor heterostructures is investigated, and a growth instability is discovered which leads to roughness on the bottom of the GaAs slabs. Adjustment of MBE growth parameters leads to the elimination of this roughness, and the result is higher nanocavity quality factors. A number of methods for optimizing the fabrication of nanocavities is presented, which lead to higher quality factors. It is shown that some fundamental limiting factor, not yet fully understood, is preventing high quality factors at wavelengths shorter than 950 nm. Silicon 1D devices without active emitters are investigated by means of a tapered microfiber loop, and high quality factors are observed. This measurement technique is compared to a cross-polarized resonant scattering method. The quality factors observed in the silicon nanocavities are higher than those observed in GaAs, consistent with our observation that quality factors are in general higher at longer wavelengths.
1D coordination polymers with polychalcogenides as linkers between metal atoms
Energy Technology Data Exchange (ETDEWEB)
Kysliak, Oleksandr; Beck, Johannes, E-mail: j.beck@uni-bonn.de
2013-07-15
The reactions of zinc metal with elemental selenium and selenium/sulfur mixtures in liquid ammonia or methylamine under solvothermal conditions in closed glass ampoules at 50 °C lead within some days specifically to [Zn(NH{sub 3}){sub 2}Se{sub 4}]{sub n} (1), [Zn(MeNH{sub 2}){sub 2}Se{sub 4}]{sub n} (2), [Zn(NH{sub 3}){sub 2}Se{sub 2.23}S{sub 1.77}]{sub n} (3). From MnCl{sub 2}, Rb{sub 2}Se and excess Se in n-butylamine [Mn({sup n}BuNH{sub 2}){sub 4}Se{sub 6}]{sub n} (4) is obtained after prolonged reaction time at ambient temperature. The compounds are sensitive towards air and loss of NH{sub 3} or the amine ligands. The crystal structures were determined by single crystal diffraction at low temperatures. As a common structural feature, all compounds represent 1D coordination polymers with polychalcogenide chains as linkers between the metal atoms and consist of infinite [M–Ch{sub m}–]{sub n} chains (M=Zn, Mn; Ch{sub m}=Se{sub 4}, (S/Se){sub 4}, Se{sub 6}). The Zn central atoms in 1–3 have tetrahedral coordination with two amine ligands, the Mn atoms in 4 have octahedral coordination with four amine ligands and cis position of the two Se atoms. Raman spectra of 1–3 show the stretching mode vibrations of the Ch{sub 4} groups. The observation of S–S, S–Se, and Se–Se vibration bands in the spectrum of 3 indicates the presence of mixed S/Se polyanions. An optical band gap of 1.86(5) eV was determined for 2 by diffuse reflectance spectroscopy. - Graphical abstract: The reaction of Zn and Se in liquid methylamine yields dark red [Zn(NH{sub 2}CH{sub 3})Se{sub 4}], a 1D coordination polymer consisting of helical Zn–Se{sub 4}–Zn– chains. - Highlights: • A series of 1D coordination polymers consisting of metal amine complexes concatenated by polychalcogenide ions is presented. • Syntheses were performed as solvothermal reactions in liquid ammonia, liquid methylamine and n-butylamine. • Crystal structures are dominated by helices [M–Ch{sub m}]{sub n}. • Raman spectra show the presence of mixed S/Se polyanions.
1D coordination polymers with polychalcogenides as linkers between metal atoms
International Nuclear Information System (INIS)
The reactions of zinc metal with elemental selenium and selenium/sulfur mixtures in liquid ammonia or methylamine under solvothermal conditions in closed glass ampoules at 50 °C lead within some days specifically to [Zn(NH3)2Se4]n (1), [Zn(MeNH2)2Se4]n (2), [Zn(NH3)2Se2.23S1.77]n (3). From MnCl2, Rb2Se and excess Se in n-butylamine [Mn(nBuNH2)4Se6]n (4) is obtained after prolonged reaction time at ambient temperature. The compounds are sensitive towards air and loss of NH3 or the amine ligands. The crystal structures were determined by single crystal diffraction at low temperatures. As a common structural feature, all compounds represent 1D coordination polymers with polychalcogenide chains as linkers between the metal atoms and consist of infinite [M–Chm–]n chains (M=Zn, Mn; Chm=Se4, (S/Se)4, Se6). The Zn central atoms in 1–3 have tetrahedral coordination with two amine ligands, the Mn atoms in 4 have octahedral coordination with four amine ligands and cis position of the two Se atoms. Raman spectra of 1–3 show the stretching mode vibrations of the Ch4 groups. The observation of S–S, S–Se, and Se–Se vibration bands in the spectrum of 3 indicates the presence of mixed S/Se polyanions. An optical band gap of 1.86(5) eV was determined for 2 by diffuse reflectance spectroscopy. - Graphical abstract: The reaction of Zn and Se in liquid methylamine yields dark red [Zn(NH2CH3)Se4], a 1D coordination polymer consisting of helical Zn–Se4–Zn– chains. - Highlights: • A series of 1D coordination polymers consisting of metal amine complexes concatenated by polychalcogenide ions is presented. • Syntheses were performed as solvothermal reactions in liquid ammonia, liquid methylamine and n-butylamine. • Crystal structures are dominated by helices [M–Chm]n. • Raman spectra show the presence of mixed S/Se polyanions
Computing 1-D atomic densities in macromolecular simulations: the Density Profile Tool for VMD
Giorgino, Toni
2013-01-01
Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment with the ability to interactively compute and visualize 1-D projections of various density functions of molecular models. We describe how the plugin is used to perform computations both via a graphical interface and programmatically. Results are presented for realistic examples, all-atom bilayer models, showing how mass and electron densities readily provide measurements such as membrane thickness, location of structural elements, and how they compare to X-ray diffraction experiments.
Amplification effects on the transmission and reflexion phases in 1D periodic systems
International Nuclear Information System (INIS)
We investigate the localization recently observed for locally non-hermitian Hamiltonians by studying the effect of the amplification on the scaling behavior of the transmission and reflection phases in 1D periodic chains of ?-potentials. The amplification here is represented by an imaginary term added to the on-site potential. It is found that both phases of the transmission and reflection amplitudes are strongly affected by the amplification term. In particular, the phases in the region of amplification become independent of the length scale while they oscillate strongly near the maximum transmission (or reflection). The interference effects on the phase in passive systems are used to interpret those observed in the presence of amplification. The phases of the transmission and reflection are found to oscillate in passive systems with increasing periods in the allowed band for the transmission phase while for the reflection phase, its initial value is always less than ?/2 in this band. (author)
Miniband lasing in a 1D dual-periodic photonic crystal
International Nuclear Information System (INIS)
In this letter, we demonstrate miniband lasing in a 1D dual-periodic photonic crystal (PC). The lasing efficiency is dramatically enhanced by about eight times and meanwhile the threshold is decreased to about 1/6 of that of the band-edge lasing in a single-periodic PC. This high optical conversion efficiency can be attributed to the extremely flat dispersion and large mode volume of the miniband induced by dual-periodicity. Numerical studies are presented to explain the mechanism of the spontaneous emission enhancement induced by the miniband, which are in good accord with our experiments. This finding may provide potential applications to low-threshold lasers and the semiconductor laser community. (letter)
1D inversion and analysis of marine controlled-source EM data
DEFF Research Database (Denmark)
Christensen, N.B.; Dodds, Kevin
2006-01-01
Marine Controlled-source electromagnetic data are now routinely collected over promising oil and gas prospects identified by seismic investigations. They allow an identification of resistive layers at depth, thereby pointing to possible oil and gas bearing sediments, where conductive salt water has been displaced by resistive oil or gas. We present preliminary results from an investigation of the applicability of one-dimensional inversion of the data. A noise model for the data set is developed and inversion is carried out with multi-layer models and 4-layer models. For the data set in question, the 1D model sections display a resistive layer at a depth of ~800 m below the sea bottom. While the thickness and resistivity of the layer are not well determined, the product of the two, the resistance, is well determined. This parameter indicates the total amount of possible hydrocarbons.
1D accretion discs around eccentric planets: observable near-infrared variability
Dunhill, Alex
2014-01-01
I present the results of 1D models of circumplanetary discs around planets on eccentric orbits. I use a classical viscous heating model to calculate emission fluxes at the wavelengths targeted by the NIRCam instrument on JWST, and compare the variability of this signal with the published NIRCam sensitivity specifications. This variability is theoretically detectable by JWST for a sufficiently viscous disc ($\\alpha \\sim 10^{-2}$) around a sufficiently eccentric planet ($e \\sim 0.1-0.2$) and if the circumplanetary disc accretes material from its parent disc at a rate $\\dot{M} \\gtrsim 10^{-7}\\, \\mathrm{M}_{\\odot}\\,\\mathrm{yr}^{-1}$. I discuss the limitations of the models used, and the implications of the result for probing the effectiveness of disc interactions for growing a planet's orbital eccentricity.
A singular perturbation approach to the steady-state 1D Poisson-Nernst-Planck modeling
Kosi?ska, I D; Schmid, G; Hänggi, P; Kostur, M
2008-01-01
The reduced 1D Poisson-Nernst-Planck (PNP) model of artificial nanopores in the presence of a permanent charge on the channel wall is studied. More specifically, we consider the limit where the channel length exceed much the Debye screening length and channel's charge is sufficiently small. Ion transport is described by the nonequillibrium steady-state solution of the PNP system within a singular perturbation treatment. The quantities, $1/\\lambda$ -- the ratio of the Debye length to a characteristic length scale and $\\epsilon$ -- the scaled intrinsic charge density, serve as the singular and the regular perturbation parameters, respectively. The role of the boundary conditions is discussed. A comparison between numerics and the analytical results of the singular perturbation theory is presented.
Improvement of core mass balance calculation in REFLA-1D/MODE1
International Nuclear Information System (INIS)
A computer code REFLA-1D/MODE1, which is used for an analysis of the reflood phase of LOCA, has been improved to eliminate unrealistic oscillations of the core mass balance calculation. In the improved core mass balance calculation, the void fraction at the quench front is evaluated and used explicitly in order to evaluate more precisely the mass balance above the quench front. The improvement eliminated the unrealistic oscillations of the core mass balance calculation without making any significant changes in the rest of the calculated results. Therefore, this improvement has increased the validity of the calculated results of that code. This is an important point especially for the system calculations. (author)
Optimal modeling of 1D azimuth correlations in the context of Bayesian inference
De Kock, Michiel B; Trainor, Thomas A
2015-01-01
Analysis and interpretation of spectrum and correlation data from high-energy nuclear collisions is currently controversial because two opposing physics narratives derive contradictory implications from the same data-one narrative claiming collision dynamics is dominated by dijet production and projectile-nucleon fragmentation, the other claiming collision dynamics is dominated by a dense, flowing QCD medium. Opposing interpretations seem to be supported by alternative data models, and current model-comparison schemes are unable to distinguish between them. There is clearly need for a convincing new methodology to break the deadlock. In this study we introduce Bayesian Inference (BI) methods applied to angular correlation data as a basis to evaluate competing data models. For simplicity the data considered are projections of 2D angular correlations onto 1D azimuth from three centrality classes of 200 GeV Au-Au collisions. We consider several data models typical of current model choices, including Fourier seri...
Recursive Estimation of Gauss-Markov Random Fields Indexed over 1-D Space
Vats, Divyanshu
2009-01-01
This paper presents optimal recursive estimators for vector valued Gauss-Markov random \\emph{fields} taking values in $\\R^M$ and indexed by (intervals of) $\\R$ or $\\Z$. These 1-D fields are often called reciprocal processes. They correspond to two point boundary value fields, i.e., they have boundary conditions given at the end points of the indexing interval. To obtain the recursive estimators, we derive two classes of recursive representations for reciprocal processes. The first class transforms the Gaussian reciprocal process into a Gauss-Markov \\emph{process}, from which we derive forward and backwards recursive representations. The second representation folds the index set and transforms the original \\emph{field} taking values in $\\R^M$ into a Markov \\emph{process} taking values in $\\R^{2M}$. The folding corresponds to recursing the reciprocal process from the boundary points and telescoping inwards. From these recursive representations, Kalman filters and recursive smoothers are promptly derived.
TAU: A 1D radiative transfer code for transmission spectroscopy of extrasolar planet atmospheres
Hollis, M D J; Tinetti, G
2013-01-01
The TAU code is a 1D line-by-line radiative transfer code, which is generally applicable for modelling transmission spectra of close-in extrasolar planets. The inputs are the assumed pressure-temperature profile of the planetary atmosphere, the continuum absorption coefficients and the absorption cross-sections for the trace molecular absorbers present in the model, as well as the fundamental system parameters taken from the published literature. The program then calculates the optical path through the planetary atmosphere of the radiation from the host star, and quantifies the absorption due to the modelled composition in a transmission spectrum of transit depth as a function of wavelength. The code is written in C++, parallelised using OpenMP, and is available for public download and use from http://www.ucl.ac.uk/exoplanets/.
Quantum propagation and confinement in 1D systems using the transfer-matrix method
Pujol, Olivier; Carles, Robert; Pérez, José-Philippe
2014-05-01
The aim of this article is to provide some Matlab scripts to the teaching community in quantum physics. The scripts are based on the transfer-matrix formalism and offer a very efficient and versatile tool to solve problems of a physical object (electron, proton, neutron, etc) with one-dimensional (1D) stationary potential energy. Resonant tunnelling through a multiple-barrier or confinement in wells of various shapes is particularly analysed. The results are quantitatively discussed with semiconductor heterostructures, harmonic and anharmonic molecular vibrations, or neutrons in a gravity field. Scripts and other examples (hydrogen-like ions and transmission by a smooth variation of potential energy) are available freely at http://www-loa.univ-lille1.fr/˜pujol in three languages: English, French and Spanish.
Monitoring heat-induced changes in soft tissues with 1D transient elastography
Benech, Nicolás; Negreira, Carlos A.
2010-03-01
In this paper 1D transient elastography was employed in fresh bovine skeletal muscle samples to assess the shear elastic modulus ? while the tissue was locally heated by means of an electrical resistance. The investigation is based on the study of the time shift of the shear wave propagation produced by the local temperature variation. The experiments show that the thermal expansion contribution to the time shift is negligible when compared with the shear wave speed variation. In such a case, the quantification of ? as a function of temperature becomes possible. Repeated experiments in different samples lead to a reproducible behavior of ? as a function of temperature. Irreversible elasticity changes are produced when the temperature exceeds a certain critical value Tc. The proposed method allows estimating this value as well as the spatial extension of the resulting thermal lesion. This point is important when considering applications in monitoring focused ultrasound surgery (FUS) because the surrounding normal tissue should remain unaffected.
Simulation of CIGS Thin Film Solar Cells Using AMPS-1D
Directory of Open Access Journals (Sweden)
J.R. Ray
2011-01-01
Full Text Available The solar cell structure based on copper indium gallium diselenide (CIGS as the absorber layer, cadmium sulfide (CdS as a buffer layer un-doped (i and Aluminium (Al doped zinc oxide (ZnO as a window layer was simulated using the one dimensional simulation program called analysis of microelectronic and photonic structures (AMPS-1D. In the simulation, the thickness of CIGS layer was varied from 300 to 3000 nm. The rest of layer’s thicknesses were kept constant, viz. 60 nm for CdS, and 80 nm and 500 nm for i- and Al-ZnO, respectively. By varying thickness of CIGS layer the simulated device performance was demonstrate in the form of current-voltage (I-V characteristics and quantum efficiency (QE.
International Nuclear Information System (INIS)
The quantum dynamics problem for a 1D chain consisting of 2N + 1 sites (N ? 1) with the interaction of nearest neighbors and an impurity site at the middle differing in energy and in coupling constant from the sites of the remaining chain is solved analytically. The initial excitation of the impurity is accompanied by the propagation of excitation over the chain sites and with the emergence of Loschmidt echo (partial restoration of the impurity site population) in the recurrence cycles with a period proportional to N. The echo consists of the main (most intense) component modulated by damped oscillations. The intensity of oscillations increases with increasing cycle number and matrix element C of the interaction of the impurity site n = 0 with sites n = ±1 (0 2 fragments and predicts the possibility of a nondissipaticts the possibility of a nondissipative energy transfer between reaction centers associated with such chains.
Harmonic Oscillator in a 1D or 2D Cavity with General Perfectly Reflecting Walls
Al-Hashimi, M H
2012-01-01
We investigate the simple harmonic oscillator in a 1-d box, and the 2-d isotropic harmonic oscillator problem in a circular cavity with perfectly reflecting boundary conditions. The energy spectrum has been calculated as a function of the self-adjoint extension parameter. For sufficiently negative values of the self-adjoint extension parameter, there are bound states localized at the wall of the box or the cavity that resonate with the standard bound states of the simple harmonic oscillator or the isotropic oscillator. A free particle in a circular cavity has been studied for the sake of comparison. This work represents an application of the recent generalization of the Heisenberg uncertainty relation related to the theory of self-adjoint extensions in a finite volume.
1D accretion discs around eccentric planets: observable near-infrared variability
Dunhill, A. C.
2015-03-01
I present the results of 1D models of circumplanetary discs around planets on eccentric orbits. I use a classical viscous heating model to calculate emission fluxes at the wavelengths targeted by the NIRCam instrument on JWST, and compare the variability of this signal with the published NIRCam sensitivity specifications. This variability is theoretically detectable by JWST for a sufficiently viscous disc (? ˜ 10-2) around a sufficiently eccentric planet (e ˜ 0.1-0.2) and if the circumplanetary disc accretes material from its parent disc at a rate dot{M} ? 10^{-7} M_{?} yr-1. I discuss the limitations of the models used, and the implications of the result for probing the effectiveness of disc interactions for growing a planet's orbital eccentricity.
D1/D5 moduli in SCFT and gauge theory, and Hawking radiation
International Nuclear Information System (INIS)
We construct marginal operators of the orbifold SCFT corresponding to all twenty near-horizon moduli in supergravity, including operators involving twist fields which correspond to the blowing up modes. We identify the operators with the supergravity moduli in a 1-1 fashion by inventing a global SO(4) algebra in the SCFT. We analyze the gauge dynamics of the D1/D5 system relevant to the splitting (Q1, Q5) ? (Q'1, Q'5 ) + (Q''1, Q''5) with the help of a linear sigma model. We show in supergravity as well as in SCFT that tile absorption cross-section for minimal scalars is the same all over the near-horizon moduli space. (author)
Controlling Quasibound States in 1D Continuum Through Electromagnetic Induced Transparency Mechanism
Gong, Z R; Zhou, Lan; Sun, C P
2008-01-01
We study the coherent scattering process of a single photon confined in an one-dimensional (1D) coupled cavity-array, where a $\\Lambda$-type three-level atom is placed inside one of the cavities in the array and behaves as a functional quantum node (FQN). We show that, through the electromagnetic induced transparency (EIT) mechanism, the $\\Lambda$-type FQN bears complete control over the reflection and transmission of the incident photon along the cavity-array. We also demonstrate the emergence of a quasibound state of the single photon inside a secondary cavity constructed by two distant FQN's as two end mirrors, from which we are motivated to design an all-optical single photon storage device of quantum coherence.
Directory of Open Access Journals (Sweden)
K. R. Santhi
2008-01-01
Full Text Available Digital filters have found their way into many products from every day consumer items such as mobile phones to advanced maritime and military communications and avionics systems. Design of digital filters faces two fundamental problems, their stability and synthesis. Recursive filters have more stability problems than nonrecursive filters. Stability of a filter can be determined by the location of the zero valued region of the denominator polynomial of its transfer function. Stability of recursive filters has been studied by many researchers for the past three decades. Several theorems on stability testing and stabilizing recursive digital filters have been already proposed. We present a new approach to test the stability problem of the one-dimensional (1-D recursive digital filters using Lagrange Multipliers. This method not only tests the stability of recursive digital filters, but also provides the stable version of the filter's transfer function if found to be unstable.
Anomalous kinetics and transport from 1D self--consistent mode--coupling theory
Delfini, L; Livi, R; Politi, A; Delfini, Luca; Lepri, Stefano; Livi, Roberto; Politi, Antonio
2006-01-01
We study the dynamics of long-wavelength fluctuations in one-dimensional (1D) many-particle systems as described by self-consistent mode-coupling theory. The corresponding nonlinear integro-differential equations for the relevant correlators are solved analytically and checked numerically. In particular, we find that the memory functions exhibit a power-law decay accompanied by relatively fast oscillations. Furthermore, the scaling behaviour and, correspondingly, the universality class depends on the order of the leading nonlinear term. In the cubic case, both viscosity and thermal conductivity diverge in the thermodynamic limit. In the quartic case, a faster decay of the memory functions leads to a finite viscosity, while thermal conductivity exhibits an even faster divergence. Finally, our analysis puts on a more firm basis the previously conjectured connection between anomalous heat conductivity and anomalous diffusion.
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Potts, Jonathan R; Giuggioli, Luca
2011-01-01
A system of two biased, mutually exclusive random walkers on an infinite 1D lattice is studied whereby the intrinsic bias of one particle is equal and opposite to that of the other. The propogator for this system is solved exactly and expressions for the mean displacement and mean square displacement (MSD) are found. Depending on the nature of the intrinsic bias, the system's behaviour displays two regimes, characterised by (i) the particles moving towards each other and (ii) away from each other, both qualitatively different from the case of no bias. The continuous-space limit of the propogator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity.
International Nuclear Information System (INIS)
MOL1D is a FORTRAN subroutine package for the method of lines solution for systems of initial-boundary-value partial differential equations in one space dimension. Using the package, a programer with limited experience in numerical analysis can accurately solve linear and nonlinear hyperbolic equations with or without discontinuities, linear and nonlinear parabolic equations (including those arising in reaction-diffusion equations), and elliptic boundary-value problems when posed as the stable time-independent solution of a parabolic equation. Systems are handled as easily as single equations, and a wide variety of boundary conditions can be accommodated, including most that arise in applications. The major advantage of the package is that initial-value problems can be solved accurately with a minimum of programing effort and with moderate computer cost. 4 figures, 1 table
1D GAS-DYNAMIC SIMULATION OF SHOCK-WAVE PROCESSES VIA INTERNET
International Nuclear Information System (INIS)
We present a Web-interface for 1D simulation of different shock-wave experiments. The choosing of initial parameters, the modeling itself and output data treatment can be made directly via the Internet. The interface is based upon the expert system on shock-wave data and equations of state and contains both the Eulerian and Lagrangian Godunov hydrocodes. The availability of equations of state for a broad set of substances makes this system a useful tool for planning and interpretation of shock-wave experiments. As an example of simulation with the system, results of modeling of multistep shock loading of potassium between polytetrafluoroethylene and stainless steel plates are presented in comparison with experimental data from Shakhray et al.(2005).
Stochastic and Deterministic Vector Chromatography of Suspended Particles in 1D-Periodic Potentials
Bernate, Jorge A
2011-01-01
We present a comprehensive description of vector chromatography that includes deterministic and stochastic transport in 1D-periodic free-energy landscapes, with both energetic and entropic contributions, and highlights the parameters governing the deflection angle, i.e. the Peclet number and the partition ratio. We also investigate the dependence of the deflection angle on the shape of the free-energy landscape by varying the width of the linear transitions in an otherwise dichotomous potential. Finally, we present experimental results obtained in a microfluidic system in which gravity drives the suspended particles and, in combination with a bottom surface patterned with shallow rectangular grooves, creates a periodic landscape of (potential) energy barriers. The experiments validate the model and demonstrate that a simple, passive microdevice can lead to vector separation of colloidal particles based on both size and density.
Topological excitations and their contribution to quantum criticality in 2+1 D antiferromagnets
Energy Technology Data Exchange (ETDEWEB)
Nazario, Zaira [Department of Physics, Stanford University, Stanford, CA 94305 (United States)]. E-mail: zaira@stanfordalumni.org; Santiago, David I. [Department of Physics, Stanford University, Stanford, CA 94305 (United States); Gravity Probe B Relativity Mission, Stanford, CA 94305 (United States)
2007-01-22
It has been proposed that there are new degrees of freedom intrinsic to quantum critical points that contribute to quantum critical physics. We study 2+1 D antiferromagnets in order to explore possible new quantum critical physics arising from nontrivial topological effects. We show that skyrmion excitations are stable at criticality and have nonzero probability at arbitrarily low temperatures. To include quantum critical skyrmion effects, we find a class of exact solutions composed of skyrmion and antiskyrmion superpositions, which we call topolons. We include the topolons in the partition function and renormalize by integrating out small size topolons and short wavelength spin waves. We obtain a correlation length critical exponent {nu}=0.9297 and anomalous dimension {eta}=0.3381.
Allègre, Vincent; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal; 10.1111/j.1365-246X.2012.05371.x
2012-01-01
The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme is then detailed for the Poisson's equation. Then, computed streaming potentials (SPs) are compared to recently published SP measurements carried out during drainage experiment in a sand column. We show that the apparent measurement of DV / DP for the dipoles can provide the SP coefficient in these conditions. Two tests have been performed using existing models for the SP coefficient and a third one using a new relation. The results show that existing models of unsaturated SP coefficients C(Sw) provide poor results in term...
Statistical, Collective and Critical Phenomena of Classical 1D Disordered Wigner Lattices
Akhanjee, S; Akhanjee, Shimul; Rudnick, Joseph
2006-01-01
We explore various aspects of classical 1D Wigner solids in the presence of disorder at T=0. In terms of the structural properties, the probability density of particle spacings is examined analytically within a weak disorder approximation and compared to numerical calculations for two different realizations of disorder: a system of particles with spatially random charge strengths and a system of like charges interacting with an external random potential. We find that the statistical configuration of the charges is sensitive to the specific type of quenched random distribution. We also discuss the multifractile character of the eigenmodes, the compressibility of the electrons, and the AC conductivity, in the context of a recently discovered Anderson transition of the random potential system.
A 1D Optomechanical crystal with a complete phononic band gap
Gomis-Bresco, J; Oudich, M; El-Jallal, S; Griol, A; Puerto, D; Chavez, E; Pennec, Y; Djafari-Rouhani, B; Alzina, F; Martínez, A; Torres, C M Sotomayor
2014-01-01
Recent years have witnessed the boom of cavity optomechanics, which exploits the confinement and coupling of optical waves and mechanical vibrations at the nanoscale. Amongst the different physical implementations,optomechanical (OM) crystals built on semiconductor slabs are particularly interesting since they enable the integration and manipulation of multiple OM elements in a single chip and provide GHz phonons suitable for coherent phonon manipulation. Different demonstrations of coupling of infrared photons and GHz phonons in cavities created by inserting defects on OM crystals have been performed. However, the considered structures do not show a complete phononic bandgap at the frequencies of interest, which in principle should allow longer dephasing time, since acoustic leakage is minimized. In this work we demonstrate the excitation of acoustic modes in a 1D OM crystal properly designed to display a full phononic bandgap for acoustic modes at about 4 GHz. The confined phonons have an OM coupling rangin...
Examination of the reflood analysis code (REFLA-1D) by PWR-FLECHT data
International Nuclear Information System (INIS)
Performance of the reflood analysis code REFLA-1D for studying the reactor safety during LOCA was examined with PWR-FLECHT experimental data and FLECHT heat transfer correlation. In the reflood phenomena under conditions of flooding velocity 25-2.5 cm/sec and system pressure 4 kg/cm2a, agreement is good between experiment and calculation. Quench time at the midplane of a heater rod under the above conditions predicted within +- 20% of error. In low pressure and in low subcooling test, agreement is not good. And, agreement is not good either in quench velocity at the low elevation. The following were indicated as necessary: 1) calculation of the liquid temperature when the quench front is low, and (2) improvement of the model in the transition flow region. (auth.)