Energy Technology Data Exchange (ETDEWEB)
Rodrigues, Bruno de O.; Oliveira, Sergio A.M. de [Universidade Estadual do Norte Fluminense (UENF), Macae, RJ (Brazil). Lab. de Engenharia e Exploracao do Petroleo (LENEP)
2004-07-01
For a processing and an interpretation of correct seismic data, it is necessary to recognize and to know as the factors act that influence in the propagation of the seismic waves, as the attenuation and the dispersion, constituting in the biggest practical impediment for the use of seismic for targets the big depths, limiting the resolution of the method. However these phenomena little are taken in consideration in the analysis of the data, thus the necessity of its bigger agreement, because if attenuation and dispersion they confuse the application of the seismic, if convenient understood and measures, can be valuable sources of information about the constitution of the rocks. Therefore, in this work the effect of the attenuation and dispersion in the data of reflection seismic had been simulated on a program, in Mat-Lab. Being able to generate 1-D seismograms, in the domain of the time, considering the normal incidence of plain wave in a package of plain, horizontal and isotropic layers, taking in account the physical attributes of the way, being able to simulate the effects of ghost and of multiples of free surface, if considering the source in the water. (author)
Frankel, A.
2009-01-01
Broadband (0.1-20 Hz) synthetic seismograms for finite-fault sources were produced for a model where stress drop is constant with seismic moment to see if they can match the magnitude dependence and distance decay of response spectral amplitudes found in the Next Generation Attenuation (NGA) relations recently developed from strong-motion data of crustal earthquakes in tectonically active regions. The broadband synthetics were constructed for earthquakes of M 5.5, 6.5, and 7.5 by combining deterministic synthetics for plane-layered models at low frequencies with stochastic synthetics at high frequencies. The stochastic portion used a source model where the Brune stress drop of 100 bars is constant with seismic moment. The deterministic synthetics were calculated using an average slip velocity, and hence, dynamic stress drop, on the fault that is uniform with magnitude. One novel aspect of this procedure is that the transition frequency between the deterministic and stochastic portions varied with magnitude, so that the transition frequency is inversely related to the rise time of slip on the fault. The spectral accelerations at 0.2, 1.0, and 3.0 sec periods from the synthetics generally agreed with those from the set of NGA relations for M 5.5-7.5 for distances of 2-100 km. At distances of 100-200 km some of the NGA relations for 0.2 sec spectral acceleration were substantially larger than the values of the synthetics for M 7.5 and M 6.5 earthquakes because these relations do not have a term accounting for Q. At 3 and 5 sec periods, the synthetics for M 7.5 earthquakes generally had larger spectral accelerations than the NGA relations, although there was large scatter in the results from the synthetics. The synthetics showed a sag in response spectra at close-in distances for M 5.5 between 0.3 and 0.7 sec that is not predicted from the NGA relations.
Michael Wysession
Teacher will demonstrate the SeisMac program. Shake the laptop in the three different directions, showing how the different directions are recorded on the three different components. Adjust both the vertical and horizontal scales to show how the same motions can be represented differently. Setting the vertical scales on -1 to +1, tilt the laptop 90 deg in each of the three directions to demonstrate that the seismograms are records of acceleration (accelerograms). When the laptop is oriented normally, the baseline of the vertical component is 1 g and the two horizontal components have baselines of 0 g. However, when the laptop is tilted the vertical component goes to 0 g and one of the horizontal components will go to 1 g. Teacher will present real 3-component seismograms for actual data, and discuss the major seismic phases (P, S, Love, Rayleigh), showing the components they arrive on: P is primarily on vertical, S is primarily on radial and transverse, Love is primarily on the transverse, and the Rayleigh wave is primarily on both vertical and radial components. Students will take turns shaking the seismometer to try to directly replicate the actual seismograms. If two sets of seismograms are used, the teacher can talk about the differences between seismograms at stations that are nearer or further from the seismometer. Has minimal/no quantitative component Addresses student misconceptions
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.
Efficient computation of NACT seismograms
Zheng, Z.; Romanowicz, B. A.
2009-12-01
We present a modification to the NACT formalism (Li and Romanowicz, 1995) for computing synthetic seismograms and sensitivity kernels in global seismology. In the NACT theory, the perturbed seismogram consists of an along-branch coupling term, which is computed under the well-known PAVA approximation (e.g. Woodhouse and Dziewonski, 1984), and an across-branch coupling term, which is computed under the linear Born approximation. In the classical formalism, the Born part is obtained by a double summation over all pairs of coupling modes, where the numerical cost grows as (number of sources * number of receivers) * (corner frequency)^4. Here, however, by adapting the approach of Capdeville (2005), we are able to separate the computation into two single summations, which are responsible for the “source to scatterer” and the “scatterer to receiver” contributions, respectively. As a result, the numerical cost of the new scheme grows as (number of sources + number of receivers) * (corner frequency)^2. Moreover, by expanding eigen functions on a wavelet basis, a compression factor of at least 3 (larger at lower frequency) is achieved, leading to a factor of ~10 saving in disk storage. Numerical experiments show that the synthetic seismograms computed from the new approach agree well with those from the classical mode coupling method. The new formalism is significantly more efficient when approaching higher frequencies and in cases of large numbers of sources and receivers, while the across-branch mode coupling feature is still preserved, though not explicitly.
Instaseis: instant global seismograms based on a broadband waveform database
van Driel, M.; Krischer, L.; Stähler, S. C.; Hosseini, K.; Nissen-Meyer, T.
2015-06-01
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 spherically symmetric models of Earth as well as other planets. 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 target="_blank">www.instaseis.net .
Carbon Nanotubes for the Generation and Imaging of Interacting 1D States of Matter
Waissman, Jonah
Low-dimensional systems in condensed matter physics exhibit a rich array of correlated electronic phases. One-dimensional systems stand out in this regard. Electrons cannot avoid each other in 1D, enhancing the effects of interactions. The resulting correlations leave distinct spatial imprints on the electronic density that can be imaged with scanning probes. Disorder, however, can destroy these delicate interacting states by breaking up the electron liquid into localized pieces. Thus, to generate fragile interacting quantum states, one requires an extremely clean system in which disorder does not overcome interactions, as well as a high degree of tunability to design potential landscapes. Furthermore, to directly measure the resulting spatial correlations, one requires an exceptionally sensitive scanning probe, but the most sensitive probes presently available are also invasive, perturbing the system and screening electron-electron interactions. In this thesis, we show how carbon nanotubes allow us to create pristine 1D electronic systems with unparalleled tunability. By realizing a new approach to device fabrication based on deterministic nano-assembly, we create devices of high complexity and low disorder by selectively attaching nanotubes of chosen bandgaps and cleanliness onto devices with large numbers of local gates. Using precision nano-assembly, we also demonstrate devices with multiple nanotubes placed at pre-determined locations. We then demonstrate the use of these devices as scanning charge detectors with the ability to image electrostatic potentials and to spatially resolve charging in a second nanotube device. By placing two such nanotube devices perpendicular to each other and bringing the two nanotubes into close proximity to each other, while distancing metal electrodes using our precise control over device geometry, we can use these devices as highly sensitive, high-resolution charge detectors that are also non-invasive. The capability to make tunable, pristine 1D electron systems and sensitive, non-invasive charge detectors could enable novel experiments with engineered interacting quantum states and direct access to their spatial correlations.
Time Scale Calculus - a new perspectives for synthetic seismogram calculations
Waskiewicz, Kamil; Debski, Wojciech
2013-04-01
Synthetic, numerically generated seismograms are one of the key factors of any interpretation of recorded seismic data. At the early stage of development, calculation of full seismic waveforms was impossible due to a limited computational resource so we were forced to used only some selected characteristics of seismic waves relatively easy for numerical calculations like first arrival times, maximum amplitude, approximate source spectra, to name a few. Continues development of computational resources as well as progress in numerical techniques has opened possibilities of generation the full, 3-component seismograms incorporating many physically important elements like wave attenuation, anisotropy or randomness of the media. Although achieved results are impressive we still need new numerical methods to tackle existing problems with the synthetic seismogram generation. In this contribution we present a novel approach to discretization of the wave equation which brings together continues and discrete numerical analysis of the seismic waves. The foundations of this new technique, called Time Scale Calculus, have been formulated by Hilger in late eighties and is very dynamically developing. The Time scale calculus, due to its universality seems to have a great potential when practical applications are considered. Thus we have decided to bring the Time Scale calculus concept closer to geophysical, or more precisely to seismological applications. This presentation is intend as a basic introduction to the time scales calculus considered from seismological point of view. We shortly present and discuss the possibility of using the Time Scales (TS) technique for solving the simplest acoustic 2D wave equation keeping in mind its particular applications for mining induced seismicity.
International Nuclear Information System (INIS)
As a part of programme of seismic detection of underground nuclear explosions, step by step variations in the amplitude spectra and waveforms of P wave signal, as it propagates from source to receiver region, are investigated. Influences on the amplitude spectra and waveforms of teleseismic p waves due to : (1) variation in the shape of reduced displacement potential, (2) variation of mantle Q values, (3) change in depth, (4) various yields, (5) spalling, and (6) variation of crustal structure at source as well as at receiver are studied. The results show that for a yield of 85 kilotons, the time structure of seismograms is nearly same for four types of reduced displacement potentials considered here. The duration of waveforms is affected both by crustal structure at source as well as due to spalling. In general, effect of receiver crust on seismograms is found to be minor. Synthesized and observed P wave seismograms for Longshot, Milrow and Cannikin underground nuclear explosions are computed at various seismometer array stations of the UKAEA. Computed seismograms compare well with the recorded ones. It is seen that: (1) overburden P wave velocity inferred from seismograms is less as compared to its value obtained from on-site measurements, and (2) the source function, the source crust transfer function, the mantle transfer function and the spalling function are the most important factors that influence shaping of spectra and seismograms. (M.G.B.)
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.
Donchenko, Sergey S.; Odinokov, Sergey B.; Bobrinev, Vladimir I.; Betin, Alexandr Y.; Zlokazov, Evgenie Y.
2015-05-01
Computer holographic synthesis allows to significantly simplify the recording scheme of microholograms in holographic memory system as the classic high precision holographic setup based on two-beam interference is removed by simple scale reduction projection scheme. Application of computer generated 1D-Fourier holograms provides the possibility of selective reconstruction of the multiplexed holograms with different orientation of data lines by corresponding rotation of anamorphic objective (cylindrical lens), used in the read-out systems. Two configurations of read-out optical scheme were investigated by our team: full-page scheme and line-by-line scheme. In the present article we report the specificities of these schemes and consider their advantages and disadvantages. The results of experimental modeling of both read-out configurations are also presented.
Kore, Anilkumar R; Yang, Bo; Srinivasan, Balasubramanian
2015-09-01
Concise, facile, and efficient synthesis of 1-(?-D-galactopyranosyl)thymine-6'-O-triphosphate, a potential probe that can generate reactive dialdehyde for DNA-enzyme cross-linking applications, was described starting from O,O'-bis(trimethylsilyl)thymine. Stannic chloride promoted glycosylation of 1,2,3,4,6-penta-O-acetyl-?-D-galactopyranose with O,O'-bis(trimethylsilyl)thymine, resulting in the formation of 1-(2,3,4,6-O-tetraacetyl-?-D-galactopyranosyl)thymine in 91% yield. Acetyl deprotection using methanolic ammonia afforded 1-(?-D-galactopyranosyl)thymine in 98% yield. The modified one-pot methodology was used to convert 1-(?-D-galactopyranosyl)thymine into 1-(?-D-galactopyranosyl)thymine-6'-O-triphosphate in 72% yield, which involves the formation of 1-(?-D-galactopyranosyl)thymine dichlorophosphoridate using POCl3 as the reagent at the monophosphorylation step followed by reaction with tributylammonium pyrophosphate and hydrolysis of resulting cyclic intermediate. PMID:26252629
A Comparison of Different-Mode Fields Generated from Grounded-Wire Source Based on the 1D Model
Zhou, Nan-Nan; Xue, Guo-qiang; Li, Hai; Younis, M.; Hou, Dong-yang; Zhong, Hua-sen; Chen, Wei-ying; Cui, Jiang-wei
2015-05-01
Abstracts Traditional TEM study mainly focuses on the generation and application of the TE field using a loop or grounded-wire source; but in recent decades, lots of efforts have been made for implementation of the TM field and even the integration of the TE field with the TM one into anomaly detection in the subsurface. However, no applicable principles have been proposed for selecting the optimal electromagnetic field for various subsurface targets. The transient electromagnetic (TEM) fields generated from grounded-wire source consist of the TE-mode response (current-carrying wire), the TE-TM mode response (grounding ends) and the combined TEM-mode response (current-carrying wire and grounding ends). This study performs a comparison of TE/TE-TM/TEM fields by generating them from grounded-wire source and testing their distribution characteristics, detection depth, and sensitivity to anomalies, using both synthetic 1D model and two field surveys in China. The comparisons demonstrate that, the detection depth of the TE-TM field is smaller than those of both the TE and combined TEM fields. Meanwhile, for electric field, the TE-TM response provides a better detection than the TEM one, but with an uneven distribution. Therefore, the TE-TM electric field requires well-designed arrangements of receiving positions when applied to real projects. For the magnetic field, the TEM response has the best detection capability compared to the TE and TE-TM ones, but is least sensitive to layer thickness and resistivity, especially for an embedded layer with low resistivity.
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.
CAV_KO: a Simple 1-D Langrangian Hydrocode for MS EXCEL™ with Automatic Generation of X-T Diagrams
Tsembelis, K.; Ramsden, B.; Proud, W. G.; Borg, J.
2007-12-01
Hydrocodes are widely used to predict or simulate highly dynamic and transient events such as blast and impact. Codes such as GRIM, CTH or AUTODYN are well developed and involve complex numerical methods and in many cases require a large computing infrastructure. In this paper we present a simple 1-D Langrangian hydrocode developed at the University of Cambridge, called CAV_KO written in Visual Basic. The motivation being to produce a code which, while being relatively simple, is useful for both experimental planning and teaching. The code has been adapted from the original KO code written in FORTRAN by J. Borg, which, in turn, is based on the algorithm developed by Wilkins [1]. The developed GUI within MS Excel™ and the automatic generation of x-t diagrams allow CAV_KO to be a useful tool for quick calculations of plate impact events and teaching purposes. The VB code is licensed under the GNU General Public License and a MS Excel™ spreadsheet containing the code can be downloaded from www.shockphysics.com together with a copy of the user guide.
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.
Jiang, Lei; Zhang, Chuanwei
2015-05-01
Majorana fermion appears near the topological phase boundary. In 2D, Majorana fermions are proposed when vortices, which stand for topological defects, are formed in topological superfluids only with Rashba spin-orbit coupling. Majorana fermions are not easily achievable in 2D cold atom systems. In our work, we show, by imprinting 1D local potentials in a finite 2D system, we can realize a 1D topological chain on demand even in originally non-topological 2D systems. A pair of zero-energy Majorana fermions can be stable in this system and exists at the ends of the topological chain. We also demonstrate the possibility to arrange an array of Majorana fermions by separating topological chains with non-topological ones. Compared with strictly 1D systems, quantum fluctuations are strongly suppressed in such high dimensional optical lattices. Because all requirements of our model are within the reach of current experiments, our proposed scheme may provide an experimental feasible platform for observing Majorana states in 2D ultra-cold atom optical lattices. We acknowledge supports from ARO, AFOSR and NSF.
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.
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
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.
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.
Fully digital 1-D, 2-D and 3-D multiscroll chaos as hardware pseudo random number generators
Mansingka, Abhinav S.
2012-10-07
This paper introduces the first fully digital implementation of 1-D, 2-D and 3-D multiscroll chaos using the sawtooth nonlinearity in a 3rd order ODE with the Euler approximation. Systems indicate chaotic behaviour through phase space boundedness and positive Lyapunov exponent. Low-significance bits form a PRNG and pass all tests in the NIST SP. 800-22 suite without post-processing. Real-time control of the number of scrolls allows distinct output streams with 2-D and 3-D multiscroll chaos enabling greater controllability. The proposed PRNGs are experimentally verified on a Xilinx Virtex 4 FPGA with logic utilization less than 1.25%, throughput up to 5.25 Gbits/s and up to 512 distinct output streams with low cross-correlation.
GPS-seismograms reveal amplified shaking in California's San Joaquin Delta region
Johanson, I. A.
2014-12-01
The March 10, 2014, the Mw6.8 Ferndale earthquake occurred off the coast of Northern California, near the Mendocino Triple Junction. Aftershocks suggest a northeast striking fault plane for the strike-slip earthquake, oriented such that the California coast is roughly perpendicular to the rupture plane. Consequently, large amplitude Love waves were observed at seismic stations and continuous GPS stations throughout Northern California. While GPS is less sensitive then broadband instruments, in Northern California their station density is much higher, potentially providing valuable detail. A total of 269 GPS stations that have high-rate (1 sps) data available were used to generate GPS-seismograms. These include stations from the Bay Area Regional Deformation (BARD) network, the Plate Boundary Observatory (PBO, operated by UNAVCO), and the USGS, Menlo Park. The Track software package was used to generate relative displacements between pairs of stations, determined using Delaunay triangulation. This network-based approach allows for higher precision than absolute positioning, because common noise sources, in particular atmospheric noise, are cancelled out. A simple least-squares network adjustment with a stable centroid constraint is performed to transform the mesh of relative motions into absolute motions at individual GPS stations. This approach to generating GPS-seismograms is validated by the good agreement between time series records at 16 BARD stations that are co-located with broadband seismometers from the Berkeley Digital Seismic Network (BDSN). While the distribution of peak dynamic displacements is dominated in long periods by the radiation pattern, at shorter periods other patterns become visible. In particular, stations in the San Joaquin Delta (SJD) region show higher peak dynamic displacements than those in surrounding areas, as well as longer duration shaking. SJD stations also have higher dynamic displacements on the radial component than surrounding areas, implying that energy has been scattered into the radial direction within the SJD.
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 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.
International Nuclear Information System (INIS)
A Faraday ideally segmented (the absence of the Hall electric current Ix=0) MHD generator channel, with a weakly ionized plasma as a working fluid, is considered. The magnetic field is applied along the z axis and the working fluid flows along the x axis. The stationary state of the flow and the stationary electric current are considered. The new quasi-one-dimensional (Q1D) electrodynamical part of a model is developed. The main assumption (besides jz = 0, Ez = 0) taken in the whole working fluid flow, is jx = 0. It means that the bending of the electric current pattern in the working fluid, due to the nonmassive electrodes and the presence of the magnetic field, is not explicitly considered. In the frame of the assumption taken, the legitimacy regarding the equation of conservation of charges: div rvec j = 0 suggests that the straight electric current pattern in the model should be narrow. In other words, it suggests replacing of a rather complicated electric current pattern in a working fluid by an artificially straight and narrow one in the modeling, promising that it would still be possible to describe the global channel parameters - its electrical output, the influence of the shape and the size of the channel on the generator performance etc
Maiti, T.; Eaton, D. W. S.; Liu, Q.; Sales de Andrade, E.
2014-12-01
Our study is based on the receiver-function (RF) analysis of a hypothetical regional geological model that extends from oceanic to thick cratonic lithosphere. RF techniques are used to study the interior of Earth. Teleseismic P waves are followed by a series of scattered waves, which occur due to P-to-S converted phases. The sequence of these scattered waves on a time series can be represented by receiver function (RF) for the station and may vary with the incidence angle and azimuth of the incoming P-wave. Here we use iterative deconvolution method to study receiver functions, which provides RF estimates with low noise levels. This method is based on least-squares minimization of the difference between the observed horizontal seismogram and a predicted signal generated by the convolution of an iterative spike train with the vertical-component of seismogram. The study is based on a hypothetical model (800x800x400km) on a mesh with 10 km grid spacing that is smoothly embedded within a standard global Earth model. Physical properties of the regional model match with prescribed surface heat-flow and geoid boundary conditions computed using an approach based on thermodynamics, mineral physics, and solid-Earth geophysics. The model also incorporates seismic anisotropy in the mantle beneath the hypothetical continent. A three dimensional model is computed that approximates the mantle flow around the hypothetical continental lithospheric keel. The anisotropy is computed from the flow model and is incorporated to the model. Synthetic seismograms are computed using SPECFEM3D_GLOBE, which provides full wave-equation modelling of seismic wave propagation incorporating material properties such as anisotropy, attenuation and fluid-solid interfaces. To ensure a realistic (non-ideal) azimuthal distribution, the event locations are based on a subset of a ten-year global catalog from 2001 to 2010 within the magnitude range from 6.0 to 7.0.
Telesca, Luciano; Chamoli, Ashutosh; Lovallo, Michele; Stabile, Tony Alfredo
2015-07-01
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.
Advanced criteria of seismic zoning and synthetic seismograms
International Nuclear Information System (INIS)
A brief revision of the traditional deterministic and probabilistic methods of first order seismic zonation, outlining their limits and possibilities, indicates that they can only lead to a kind of ''post-event'' zonation, which has a limited local validity. The strong influence of laterial heterogeneities and of source properties on the spatial distribution of Peak Ground Acceleration (PGA) and of the Total Energy of ground motion (W), indicates that the traditional methods require a deep revision. The method we have developed and applied to a first-order seismic zoning of the whole Italian territory and to the microzoning of specific objects, being based on the computation of synthetic seismograms, makes it possible and necessary to take source and propagation effects into account, fully utilizing the large amount of geological and geotechnical data, already available. Even though it falls in the domain of deterministic approaches, the method is very suitable for inclusion in the definition of new integrated procedures which combine probabilistic and deterministic approaches and allow us to minimize the present drawbacks which characterise the two methods when they are considered separately. If the seismotectonic regime is well known, a very important practical aspect of our deterministic approach is the immediate capability to direct the rescue intervention of the Civil Defence where the greatest damage is expected, by drawing post-event synthetic isoseismals for the source regions. Detailed modelling of ground motion for realistic two-dimensional media is a low-cost but very powerful tool for the prevention aspects of Civil Defence since it allows the computation of realistic seismic input for important structures based on the definition of a wide set of possible scenarios, which can be immediately used in the design of new seismo-resistant constructions and in the reinforcement of existing structures. (author). 65 refs, 14 figs
Usability of ocean-bottom seismograms for broadband waveform tomography
Eibl, Eva P. S.; Sigloch, Karin
2013-04-01
Recordings made by broadband seismometers on the ocean-bottom are generally noisier than recordings of land stations using the same sensor type. The primary reason is that oceanic recordings are more affected by microseismic noise, which originates in the oceans. A similar drawback applies to data from stations on oceanic islands. The frequency band between 0.05 Hz and 0.2 Hz is most affected by microseismic noise -- unfortunately a large overlap with the band that is most useful in highly-resolving body-wave tomography when using land stations. On the other hand, waveform inversion methods, unlike traditional ray theory, do not necessarily depend on the availability of clean, pulse-like broadband signals across the entire frequency range. For example in finite-frequency tomography, the method of our choice, modelling procedures permit the exclusion of unusable frequency bands on a case-by-case basis. Hence we investigate to what extent seismograms from the ocean-bottom and from island stations can be used for broadband waveform inversion of teleseismic P-waves, as compared to continental land stations. We have re-analyzed data from one of the largest onshore-offshore, broadband, long-term seismological experiment to date: the Hawaiian PLUME project (Wolfe et al. 2009, Laske 2009). The data quality was studied in eight overlapping frequency bands (dominant periods between 30.0 s and 2.7 s), for year-long records from 62 ocean-bottom stations (January 2005 - June 2007), complemented by seismograms from 74 regional island stations and 236 continental stations from four different networks on the Pacific-rim, recorded in the same time frame. P-wave seismograms from 103 earthquakes of moment magnitude 6.2 and above, recorded at epicentral distances of 32° to 85° to Hawaii were assessed in this study. The quality of the recorded data was evaluated by calculating the cross-correlation coefficient between the first 1.5 dominant periods of real and predicted waveforms, in eight frequency passbands and on the broadband waveform, after careful correction for source parameters and source time function (Sigloch and Nolet 2006). As expected, permanent continental stations were quieter than permanent island stations in the Pacific, (independent of frequency band), and island stations were quieter than ocean-bottom stations. Relative data quality for both types of oceanic stations is lowest for dominant periods between 11s and 3 s. We present statistics for the fraction of usable data, as a function of station type, frequency band, and sensor type. In the lowest frequency band 55%, 71% and 90% of the data recorded by the PLUME stations, island stations and land stations, respectively, can be used for seismic tomography. These values drop with increasing frequency, to a minimum of 12% for the island stations, 8% for OBS stations and 33% for the land stations. We also compare data quality by OBS sensor type (Nanometrics T-40, Nanometrics T-240, Güralp CMG-3T). We find that frequency bands around 2.7 s and between 20.0 to 30.0 s have low noise levels but have not been used for tomography by the project PIs. A multiple-frequency waveform inversion including these additional bands and wave paths, as well as a larger number of earthquakes (101 versus 97 and 59 used in the original studies by Wolfe et al. 2009 and Wolfe et al. 2011) should be able to improve the resolution of the velocity structure in the upper and lower mantle beneath the Hawaiian hotspot. References: Laske, G., Collins, J. A., Wolfe, C. J., Solomon, S. C., Detrick, R. S., Orcutt, J. A., Bercovici, D., Hauri, E. H. (2009). Probing the Hawaiian hotspot with new broadband ocean bottom instruments. Eos Trans. AGU, 90(41), 362-363. Sigloch, K., & Nolet, G. (2006). Measuring finite-frequency body-wave amplitudes and traveltimes. Geophysical Journal International, 167(1), 271-287, doi:10.1111/j.1365-246X.2006.03116.x Wolfe, C.J, Solomon, S.C., Laske G., Collins, J.A., Detrick, R.S., Orcutt, J.A., Bercovici, D., and Hauri, E.H. (2009) Mantle shear-wave velocity structure bene
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.
Energy Technology Data Exchange (ETDEWEB)
Luiz, M. [Universidad Nacional de La Patagonia, San Juan Bosco (Argentina); Soltermann, A. T.; Biasutti, A.; Garcia, N. A. [Universidad Nacional de Rio Cuarto, Rio Cuarto (Argentina)
1996-01-01
Anaerobic photo-oxidation of a series of dihydroxynapthalenes (DHN)was studied.It was found that the interaction of O{sub 2}({sup 1d}elta{sup {sub g}}) yielded a quenching rate constant, the range depending on solvent polarity, pH, and substitution pattern of the DHN. The mechanism of the interaction appeared to be mediated by an encounter complex with a considerable charge transfer component, similar to the photo-oxidative kinetic behavior of simple substituted phenols and dihydroxybenzenes. DHN were found to be highly reactive towards O{sub 2}({sup 1d}elta{sup {sub g}}) when the hydroxy groups are ionized. Various tests indicated that DHN are good candidates for an environmental O{sub 2}({sup 1d}elta{sub g})-mediated photo-oxidation. 27 refs., graphs.
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.
Qiu, Zehua; Chi, Shunliang; Wang, Zhenming; Carpenter, Seth; Tang, Lei; Guo, Yanping; Yang, Guang
2015-06-01
At a sampling rate of 100 samples per second, the YRY-4 four-gauge borehole strainmeters (FGBS) are capable of recording transient strains caused by seismic waves such as P and S waves or strain seismograms. At such a high sampling rate, data from the YRY-4 strainmeters demonstrate fairly satisfactory self-consistency. The strain tensor seismograms demonstrate the senses of motion of P waves, that is, the type of seismic wave travels in the direction of the maximum normal strain change. The observed strain patterns of S waves significantly differ from those of P waves and should contain information about the source mechanism. Spectrum analysis shows that the strain seismograms are consistent with conventional broadband seismograms from the same site.
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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
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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.
Fontes, L. R.; Isopi, M.; Newman, C. M.; Stein, D. L.
2001-01-01
We derive exact expressions for a number of aging functions that are scaling limits of non-equilibrium correlations, R(tw,tw+t) as tw --> infinity with t/tw --> theta, in the 1D homogenous q-state Potts model for all q with T=0 dynamics following a quench from infinite temperature. One such quantity is (the two-point, two-time correlation function) when n/sqrt(tw) --> z. Exact, closed-form expressions are also obtained when one or more interludes of infinite temperature dyn...
Capdeville, Y.; Gung, Y.; Romanowicz, B.
2002-12-01
The spectral element method (SEM) has recently been adapted successfully for global spherical earth wave propagation applications. Its advantage is that it provides a way to compute exact seismograms in a 3D earth, without restrictions on the size or wavelength of lateral heterogeneity at any depth, and can handle diffraction and other interactions with major structural boundaries. Its disadvantage is that it is computationally heavy. In order to partly address this drawback, a coupled SEM/normal mode method was developed (Capdeville et al., 2000). This enables us to more efficiently compute bodywave seismograms to realistically short periods (10s or less). In particular, the coupled SEM/normal mode method is a powerful tool to test the validity of some analytical approximations that are currently used in global waveform tomography, and that are considerably faster computationally. Here, we focus on several approximations based on normal mode perturbation theory: the classical "path-average approximation" (PAVA) introduced by Woodhouse and Dziewonski (1984) and well suited for fundamental mode surface waves (1D sensitivity kernels); the non-linear asymptotic coupling theory (NACT), which introduces coupling between mode branches and 2D kernels in the vertical plane containing the source and the receiver (Li and Tanimoto, 1993; Li and Romanowicz, 1995); an extension of NACT which includes out of plane focusing terms computed asymptotically (e.g. Romanowicz, 1987) and introduces 3D kernels; we also consider first order perturbation theory without asymptotic approximations, such as developed for example by Dahlen et al. (2000). We present the results of comparisons of realistic seismograms for different models of heterogeneity, varying the strength and sharpness of the heterogeneity and its location in depth in the mantle. We discuss the consequences of different levels of approximations on our ability to resolve 3D heterogeneity in the earth's mantle.
Gonzalez-Orduno, A.; Fucugauchi, J. U.; Monreal, M.; Perez-Cruz, G.; Salas de León, D. A.
2013-05-01
The seismic reflection method has been successfully applied worldwide to investigate subsurface conditions to support important business decisions in the oil industry. When applied in the marine environment, useful reflection information is limited to events on and below the sea floor; Information from the water column, if any, is disregarded. Seismic oceanography is emerging as a new technique that utilize the reflection information within the water column to infer thermal-density contrasts associated with oceanographic processes, such as cyclonic-anticyclonic eddies, ascending-descending water flows, and water flows related to rapid topographic changes on the sea floor. A seismic investigation to infer such oceanographic changes in one sector of the Campeche Canyon is in progress as a research matter at the Instituto de Ciencias del Mar y Limnologia from the University of Mexico (UNAM). First steps of the investigation consisted of creating synthetic seismograms based on oceanographic information (temperature and density) derived from direct observation on a series of close spaced depth points along vertical profiles. Details of the selected algorithms used for the transformation of the oceanographic data to acoustic impedances data sets and further construction of synthetic seismograms on each site and their representation as synthetic seismic sections, are presented in this work, as well as the road ahead in the investigation.
Brüstle, A.; Friederich, W.; Meier, T.; Gross, C.
2014-10-01
Historic analogue seismograms of the large 1956 Amorgos twin earthquakes which occurred in the volcanic arc of the Hellenic subduction zone (HSZ) were collected, digitized and reanalyzed to obtain refined estimates of their depth and focal mechanism. In total, 80 records of the events from 29 European stations were collected and, if possible, digitized. In addition, bulletins were searched for instrument parameters required to calculate transfer functions for instrument correction. A grid search based on matching the digitized historic waveforms to complete synthetic seismograms was then carried out to infer optimal estimates for depth and focal mechanism. Owing to incomplete or unreliable information on instrument parameters and frequently occurring technical problems during recording, such as writing needles jumping off mechanical recording systems, much less seismograms than collected proved suitable for waveform matching. For the first earthquake, only seven seismograms from three different stations at Stuttgart (STU), Göttingen (GTT) and Copenhagen (COP) could be used. Nevertheless, the waveform matching grid search yields two stable misfit minima for source depths of 25 and 50 km. Compatible fault plane solutions are either of normal faulting or thrusting type. A separate analysis of 42 impulsive first-motion polarities taken from the International Seismological Summary (ISS bulletin) excludes the thrusting mechanism and clearly favors a normal faulting solution with at least one of the potential fault planes striking in SW-NE direction. This finding is consistent with the local structure and microseismic activity of the Santorini-Amorgos graben. Since crustal thickness in the Amorgos area is generally less than 30 km, a source depth of 25 km appears to be more realistic. The second earthquake exhibits a conspicuously high ratio of body wave to surface wave amplitudes suggesting an intermediate-depth event located in the Hellenic Wadati-Benioff zone. This hypothesis is supported by a focal mechanism analysis based on first-motion polarities, which indicates a mechanism very different from that of the first event. A waveform matching grid search done to support the intermediate-depth hypothesis proved not to be fruitful because the body wave phases are overlain by strong surface wave coda of the first event inhibiting a waveform match. However, body to surface wave amplitude ratios of a modern intermediate-depth event with an epicenter close to the island of Milos observed at stations of the German Regional Seismic Network (GRSN) exhibit a pattern similar to the one observed for the second event with high values in a frequency band between 0.05 Hz and 0.3 Hz. In contrast, a shallow event with an epicenter in western Crete and nearly identical source mechanism and magnitude, shows very low ratios of body and surface wave amplitude up to 0.17 Hz and higher ratios only beyond that frequency. Based on this comparison with a modern event, we estimate the source depth of the second event to be greater than 100 km. The proximity in time and space of the two events suggests a triggering of the second, potentially deep event by the shallow first one.
Directory of Open Access Journals (Sweden)
Bagus Jaya Santosa
2005-11-01
Full Text Available In this research the S speed structure is investigated by seismogram analysis of Washington's earthquake, C022801L using data of TUC station, Tucson, Arizona, U.S.A. The seismogram comparison between the observed and the synthetic seismogram is conducted in time domain and three components simultaneously. The initially input for the calculation of synthetic seismogram is earth model of PREMAN and CMT solution from the earthquake. A low-pass Butterworth filter with corner frequency of 20 mHz is convolved to observed and synthetic seismogram. Waveform comparison shows a real deviation when travel time and waveform of some wave phase are compared, namely on S wave, surface wave of Love and Rayleigh and wave ScS and ScS-2. This research shows, how sensitive the waveform is to the earth model, better than the method of travel time or the dispersion analysis. Research hereinafter is addressed to finish the found discrepancies at S wave, surface wave of Love and Rayleigh and ScS and ScS-2 wave, in observation station TUC. To obtain the seismogram fitting, correction for S speed structure in earth model is needed, that are changes of earth crust thickness, the speed model of ? in upper mantle covering the speed gradient of ?h and value of zeroeth order coefficient for the ?h and ?v, for accomplishing the discrepancies at surface wave of Love and Rayleigh. Further correction on S speed is conducted to accomplish the deviation at S wave at earth layering systems from Upper Mantle up to a 630 km depth. Mean while for the ScS and ScS-2 wave phase the correction is carried out on S speed in the earth layers up to CMB. Fitting Seismogram is obtained at waveform of various wave phases that is S wave, surface wave of Love and Rayleigh and ScS, ScS-2 wave, either on travel time or especially also at oscillation number in Love wave. This result indicates that the anisotropy is occurred not only in upper mantle but till deeper earth layers, till CMB.
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Perez-Alvarez, R.; Garcia-Moliner, F. [University ' Jaume I' , Castellon de la Plana (Spain)]. E-mails: perez@exp.uji.es; garmol@ext.uji.es; Trallero-Herrero, C. [University ' Jaume I' , Castellon de la Plana (Spain)
2001-07-01
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)
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.
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Vadim A. An
2015-06-01
This second dataset consists of more than 3700 waveforms (digital seismograms from almost 500 nuclear explosions in Eurasia, many of them recorded at regional distances. It is important as a training set for the development and evaluation of seismological methods of discriminating between earthquakes and underground explosions, and can be used for assessment of three-dimensional models of the Earth’s interior structure.
Instaseis: Instant Global Broadband Synthetic Seismograms Based on a Waveform Database
van Driel, Martin; Stähler, Simon; Krischer, Lion; Hutko, Alex; Hosseini, Kasra; Nissen-Meyer, Tarje
2015-04-01
Spherical models for planetary bodies represent a common characterization of bulk global material properties, often satisfying up to 90% of recorded data. Our new methodology combines accurate seismic wave propagation with symmetry properties of radiation patterns, reciprocity, and high-order interpolation to deliver a comprehensive waveform database from which arbitrary source-receiver configurations and high-frequency record sections for a given model can be extracted within seconds. The database thus acts as a once-and-for-all solution to wave propagation in spherically symmetric models. This not only frees users from re-running wave propagation codes, but opens doors to new applications in which vast numbers of parameter alterations are desired such as modifications in source properties (moment tensor, source-time function, location), filtering, or background models, e.g. in a framework for probabilistic uncertainty assessment. Using reciprocity, two simulations with the global wave-propagation solver, AxiSEM (Nissen-Meyer et al. 2014, www.axisem.info), suffice to generate a complete database of Green's functions: one as a "source" for the vertical, and one for both horizontal components. Storage of the propagating spatio-temporal displacement field at all distances (0-180 degrees) and depths (0-700km for earthquakes) on the actual basis of the spectral-element mesh ensures the same accuracy as for the numerical wave propagation solution upon posteriori interpolation. The ease of computation (10K CPU hours) and tolerable storage requirements (a few TB for 1Hz waveforms) implies that multiple such databases may be computed for several models at high resolution (1Hz for global-Earth synthetics), e.g. continental versus oceanic crust, anisotropic versus isotropic, or various lower-mantle models. Further applications include the efficient generation of reference synthetics for global tomography, wavefields for hybrid 1D-3D methods, and responses to finite-fault sources. Instaseis offers a user friendly interface written in Python and directly integrates with ObsPy, it includes a GUI and can run as Client/Server via HTTP, such that the databases can be accessed and shared via internet without the necessity to download large volumes of data. A first example of such a database is being developed and stored at the IRIS DMC (Seattle), to deliver on-demand customizable synthetics.
A comparison of two methods for earthquake source inversion using strong motion seismograms
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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.
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.
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
Hosseini, M.; Pezeshk, S.; Pujol, J. M.
2012-12-01
The use of Rayleigh waves phase velocity dispersion curves for the determination of shallow shear-wave velocity profiles is widespread in the context of geotechnical, earthquake engineering, and seismic hazard applications because it is a low-cost technique. A significant problem with this technique, however, is its intrinsic non-uniqueness, and although this problem is widely recognized, there have not been systematic efforts to develop approaches to reduce the pervasive uncertainty that affects the velocity profiles determined by the inversion. To minimize the lack of uniqueness different methodologies can be combined together. Genetic algorithms (GA) can be used to maximize the probability of finding the global optimum. Furthermore, considering higher modes of propagation will help reducing the non-uniqueness problem. Here, we present one approach based on the use of synthetic seismograms, which has been tested successfully with synthetic data designed to resemble actual data. For example, two completely different velocity models produce essentially the same dispersion curves for the fundamental mode and the first three higher modes, which mean that there is no objective way to discriminate between the two models. On the other hand, the corresponding synthetic traces have significant differences, which allow choosing the appropriate velocity model. The goal of this study is to apply the synthetic seismogram technique to data collected with method of multi-channel analysis of surface waves (MASW). We use simulated tests to assess the usefulness and the limitations of this technique. We use a target velocity profile with an assumed water level for calculation of synthetic experimental dispersion curve, which is used in the inversion process. The inversion process results in several different inverted velocity profiles with theoretical dispersion curves similar to the target dispersion curve. Applying the synthetic seismogram technique, it is possible to robustly find the inverted velocity of the target profile.
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Bagus Jaya Santosa
2008-03-01
Full Text Available The S wave velocity structure at subduction zone under Sumatra-Java was investigated through seismogram analysis in time domain and three Cartesian’s components simultaneously. The main data set was the comparison between the measured seismogram and the synthetic one, not the travel time data. The synthetic seismogram was calculated with the GEMINI method. The seismogram comparison shows that the global earth mantle of PREMAN gives deviating synthetic seismogram and has later arrival times than the measured one. The gradient bh in the upper mantle is altered to positive from its negative slope as in the PREMAN model, and positive corrections are added to the zero order of polynomial’s coefficients in all earth mantle layers. The excellent fitting, as well as travel time or waveform, were obtained on the surface waves of Love and Rayleigh, the S and SS mantle and repetitive depth waves. The additional positive corrections were also confirmed by a well fitting on the repetitive depth waves. This result expresses that part of the earth mantle that due to tectonic processes has positive anomaly on S wave velocity and vertical anisotropy in all of the earth mantle layers.
Lee, E. J.; Chen, P.; Jordan, T. H.; Maechling, P. J.; Denolle, M.; Beroza, G. C.
2014-12-01
We have constructed a high-resolution model for the Southern California crust, CVM-S4.26, by inverting more than half-a-million waveform-misfit measurements from about 38,000 earthquake seismograms and 12,000 ambient-noise correlagrams. The inversion was initiated with the Southern California Earthquake Center's Community Velocity Model, CVM-S4, and seismograms were simulated using K. Olsen's staggered-grid finite-difference code, AWP-ODC, which was highly optimized for massively parallel computation on supercomputers by Y. Cui et al. We navigated the tomography through 26 iterations, alternating the inversion sequences between the adjoint-wavefield (AW) method and the more rapidly converging, but more data-intensive, scattering-integral (SI) method. Earthquake source errors were reduced at various stages of the tomographic navigation by inverting the waveform data for the earthquake centroid-moment tensors. All inversions were done on the Mira supercomputer of the Argonne Leadership Computing Facility. The resulting model, CVM-S4.26, is consistent with independent observations, such as high-resolution 2D refraction surveys and Bouguer gravity data. Many of the high-contrast features of CVM-S4.26 conform to known fault structures and other geological constraints not applied in the inversions. We have conducted several other validation experiments, including checking the model against a large number (>28,000) of seismograms not used in the inversions. We illustrate this consistency with the excellent fits at low frequencies (? 0.2 Hz) to three-component seismograms recorded throughout Southern California from the 17 Mar 2014 Encino (MW4.4) and 29 Mar 2014 La Habra (MW5.1) earthquakes, and we show these fits to be much better than those obtained by two community velocity models in current use, CVM-S4 and CVM-H11.9. We conclude by describing some of the novel features of the CVM-S4.26 model, which include unusual velocity reversals in some regions of the mid-crust.
O. Kulhánek; A. Ayele
2000-01-01
Source parameters for three majo earthquakes in the East African rift are re-computed from historical seismograms and bulletins. The main shock and the largest foreshock of the August 25, 1906 earthquake sequence in the main Ethiopian rift are re-located on the eastern shoulder of the rift segment.The magnitude of the main shock is estimated to be 6.5 (Mw) from spectral analysis. The December 13, 1910 earthquake in the Rukwa rift (Western Tanzania) indicated a significant strike-slip componen...
IMPROVEMENTS OF RIVER MODELING 1D DATA PREPARATION
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ION-MARIAN MOISOIU
2012-11-01
Full Text Available Improvements of river modeling 1D data preparation. The importance of hydrographical networks data and the need for detailed studies do generate an increase of projects in this specialized area and a diversification of river mathematical modeling software. River mathematical modeling can be done in two ways, namely; the "2D mode" and the “1D mode”. The “2D mode” is where a digital terrain model of a full hydrographical basin must be produced and "1D mode" is where only cross sections, long sections and structures elevations needs to be presented in a graphical environment and in a specific formats for the mathematical modeling software. This paper will show the principle of a custom built GIS, specially created to help the preparation of 1D river modeling data. The benefits are; elimination of human errors, automated processing, increasing productivity, flexible output and cost reduction.
International Nuclear Information System (INIS)
Signal phase values are crucial in seismic data interpretation to enhance the analysis of amplitudes, bright spots, dim spots etc. Phase values can be zeroed in a section to enhance signal comparison which can be related to velocities and other petro-physical properties. Homomorphic signal processing and deconvolution both require exact phase value estimates. Consequently, in-depth investigations are necessary to solve problems of phase estimation in various wave propagation situations. Meanwhile, phase values are often measured modulo-2 called principal values and the amount of phase estimation in various wave propagation situations. Meanwhile, values are often measured modulo-2 called principal values and the amount of phase information is independent of any integer multiple of 2 added to the principal value phase. However, to be useful for linear processing, this principal value phase has to be unwrapped. This will result in a continuous function, the 2 discontinuities being eliminated, or at least reduced. Operations like deconvolution and homomorphic signal processing require unwrapped phase values. Phase unwrapping is applied to pre-stack data for the computation of PVA phase variation with angle of incidence attribute used to improve processing and interpretation.Conventional 1D phase unwrapping algorithms integrate the wrapped phase difference between two contiguous points. This was later improved to use adaptive integration of phase differences. Alternatively, phase difference ambiguity due to sparse sampling can be overcome by taking samples at progressively closer intervals. These methods are often inadequate due to problems of aliasing caused by rapid phase value variations. We develop a 1D phase unwrapping technique using the amplitude of a complex trace and discrete Fourier transforms. This technique is simple, very reliable and less sensitive to aliasing. It exploits the periodicity of Fourier transform to unwind wrapped phase values. We demonstrate this technique using synthetic and real data
Intermittency and clustering in the 1-D lattice gas model
International Nuclear Information System (INIS)
We construct generating functions of the scaled factorial moments of the distribution of the particles and links (two neighbouring particles) in the 1-D statistical system for variable bin size. The results show intermittent-like behaviour. We compare the intermittency signal for particles and links and discuss a possible influence of the clustering in hadronization on the size of fluctuations. (orig.)
1D copper nanostructures: progress, challenges and opportunities.
Bhanushali, Sushrut; Ghosh, Prakash; Ganesh, Anuradda; Cheng, Wenlong
2015-03-18
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
Hasbrouck, W.P.
1983-01-01
Processing of data taken with the U.S. Geological Survey's coal-seismic system is done with a desktop, stand-alone computer. Programs for this computer are written in the extended BASIC language used by the Tektronix 4051 Graphic System. This report presents computer programs to perform X-square/T-square analyses and to plot normal moveout lines on a seismogram overlay.
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O. Kulhánek
2000-06-01
Full Text Available Source parameters for three majo earthquakes in the East African rift are re-computed from historical seismograms and bulletins. The main shock and the largest foreshock of the August 25, 1906 earthquake sequence in the main Ethiopian rift are re-located on the eastern shoulder of the rift segment.The magnitude of the main shock is estimated to be 6.5 (Mw from spectral analysis. The December 13, 1910 earthquake in the Rukwa rift (Western Tanzania indicated a significant strike-slip component from teleseismcs body-waveform inversion for fault mechanism and seismic moment. The January 6, 1928 earthquake in the Gregory rift (Kenya showed a multiple rupture process and unusually long duration for a size of 6.6(Mw. The May 20, 1990 earthquake in Southern Sudan, mentioned merely for the sake of comparison, is the largest of all instrumentally recorded events in the East African rift system. Despite the fact that the mode of deformation in the continental rift is predominantly of extensional nature, the three largest earthquakes known to occur in the circum-Tanzanian craton have shallow focal depths and significant strike-slip component in their fault mechanisms. This and similar works will enrich the database for seismic hazard assessment in East Africa.
Fabrication and Characterization of 1-D diffusing elements
Bitterli, R.; Kim, M. -S.; Scharf, T.; Herzig, H.P.
2009-01-01
Certain high power laser applications require thin homogeneous laser lines. In this paper we describe the concept, fabrication and characterization of a 1-D diffuser that generates such a line. The device is based on an array of concave cylinder lenses with a statistically distributed width and a fix radius of curvature. The fabrication is based on isotropic wet etching of fused silica. Measurement results are compared to simulation which show good agreement.
Allstadt, Kate
2013-09-01
methods can substantially improve the characterization of the dynamics of large and rapid landslides. Such landslides often generate strong long-period seismic waves due to the large-scale acceleration of the entire landslide mass, which, according to theory, can be approximated as a single-force mechanism at long wavelengths. I apply this theory and invert the long-period seismic waves generated by the 48.5 Mm3 August 2010 Mount Meager rockslide-debris flow in British Columbia. Using data from five broadband seismic stations 70 to 276 km from the source, I obtain a time series of forces the landslide exerted on the Earth, with peak forces of 1.0 × 1011 N. The direction and amplitude of the forces can be used to determine the timing and occurrence of events and subevents. Using this result, in combination with other field and geospatial evidence, I calculate an average horizontal acceleration of the rockslide of 0.39 m/s2 and an average apparent coefficient of basal friction of 0.38 ± 0.02, which suggests elevated basal fluid pressures. The direction and timing of the strongest forces are consistent with the centripetal acceleration of the debris flow around corners in its path. I use this correlation to estimate speeds, which peak at 92 m/s. This study demonstrates that the time series recording of forces exerted by a large and rapid landslide derived remotely from seismic records can be used to tie post-slide evidence to what actually occurred during the event and can serve to validate numerical models and theoretical methods.
Girard, Caroline; Raveu, Nathalie; Perrussel, Ronan; Li, Jia; Lanteri, Stéphane
2012-01-01
The hybridization between two numerical methods, the 1D Wave Concept Iterative Procedure (WCIP) and the 2D Finite Element Method (FEM), is introduced. Preliminary numerical results are also presented.
Reflected Phases Apparent in Local Event Seismograms at Uturuncu Volcano, Bolivia
Farrell, A. K.; McNutt, S. R.
2014-12-01
Uturuncu volcano is located in the central Andes at 22.27° S, 67.18° W. Despite 270,000 years of volcanic dormancy, a satellite geodetic InSAR survey by Pritchard and Simons (2002) shows an inflation rate of 1.5-2 cm/yr over an area with a width of 70 km (Pritchard and Simons, 2002). The source was modeled, using a Mogi source, to 15-17 km deep located ~3 km to the southwest of Uturuncu's summit. Current studies have found a source area of decreased density with respect to the crust and with a Vp/Vs ratio of > 1.9, with a depth matching that derived from the deformation signature [Potro et al., 2013; M.E. West, H. McFarlin, D. Christensen written comm.] Determining the size, geographic location, source depth, and source shape of deformation at Uturuncu volcano is important because this can indicate either (or a combination of) injection of magma from depth into the system, melting of crustal rock from a previous injection, or the build-up of pressure in a hydrothermal system (Pritchard and Simons, 2002). We are using phases arriving between the P and S phases to constrain some of the deformation source parameters. These result from the interaction of seismic waves with the attenuating source, believed to be local thickening of the regional shallow crustal magma body. Analysis of 200 local events spanning the period of PLUTONS seismic network operation (April 2010 to October 2012) reveals that 55 of these events show at least one station with a phase arrival between the P and S phases. If this trend holds as expected during analysis of the other 377 shallow local events, then 25.7% of the local events will generate an anomalous phase. No observable differences in the frequency of phase occurrence have been noted with time; however, the locations of earthquakes generating this phase strongly cluster (39 of 55) within a 10 km radius of the volcano, skewed to the south and west. There is the possibility of a NE-SW trend between the earthquake epicenter and the locations of the stations showing phases, suggesting anisotropy of the phase source body.
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.
PALLAS-1D(V3): variable-dimension version of PALLAS-1D(VII)
International Nuclear Information System (INIS)
The PALLAS-1D(V3) program is a variable-dimension version of the PALLAS-1D(VII) code, which is the revised version of the PALLAS-PL, SP-Br code. The PALLAS-1D(VII) code could treat transport of both neutrons and gamma rays, in particular of secondary photons including the bremsstrahlung and annihilation photons. This document gives a full description of input and output data for PALLAS-1D(V3) code, also with the input description of several sample problems. (author)
Girard, Caroline; Raveu, Nathalie; Lanteri, Stéphane; Perrussel, Ronan
2012-01-01
An hybridization between two numerical methods, the 1d Wave Concept Iterative Procedure (WCIP) and the 2d Finite Element Method (FEM), is developed. Using two examples, comparisons are provided between the new hybrid method and an analytic solution, when available, or the WCIP alone.
1-D equations of radiation hydrodynamics
International Nuclear Information System (INIS)
The radiation transfer equation is derived in the comoving frame, in curvilinear coordinates, to first order in u/c, no symmetry being assumed. This equation is then specialized to 1-D, and its moments are calculated for the limiting case of Thomson scattering. The equations of radiation hydrodynamics are also given
First Observation of Upsilon(1D) States
Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; McGee, S; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Sun, W M; Weinstein, A J; Mahapatra, R; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G T; Vogel, H; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, David G; Drell, P S; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Mistry, N B; Nordberg, E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Thayer, J G; Urner, D; Viehhauser, G; Warburton, A; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stöck, H; Yelton, J; Brandenburg, G; Kim, D Y J; Wilson, R; Benslama, K; Eisenstein, B I; Ernst, J; Gollin, G D; Hans, R M; Karliner, I; Lowrey, N; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Ammar, R; Besson, D; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Li, S Z; Poling, R A; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ahmed, S; Alam, M S; Jian, L; Saleem, M; Wappler, F; Eckhart, E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pedlar, T K; Thayer, J B; Von Törne, E; Wilksen, T; Zoeller, M M; Muramatsu, H; Richichi, S J; Severini, H; Skubic, P L; Dytman, S A; Müller, J A; Nam, S; Savinov, V; Chen, S; Hinson, J W; Lee, J; Miller, D H; Pavlunin, V; Shibata, E I; Shipsey, I P J; Cronin-Hennessy, D; Lyon, A L; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Maravin, Y; Stroynowski, R; Artuso, M; Boulahouache, C; Bukin, K; Dambasuren, E; Khroustalev, K; Mountain, R; Nandakumar, R; Skwarnicki, T; Stone, S; Wang, J C; Mahmood, A H
2002-01-01
The CLEO III experiment has recently accumulated a large statistics sample of 4.73 x 10^6 Upsilon(3S) decays. We present the first evidence for the production of the triplet Upsilon(1D) states in the four-photon cascade, Upslion(3S) -> gamma chi_b(2P), chi_b(2P) -> gamma Upsilon(1D), Upsilon(1D) -> gamma chi_b(1P), chi_b(1P) -> gamma Upsilon(1S), followed by the Upsilon(1S) annihilation to e+ e- or mu+ mu-. The signal has a significance of 9.7 standard deviations. The measured product branching ratio for these five decays, (3.3 +- 0.6 +- 0.5) x 10^{-5}, is consistent with the theoretical estimates. We see a 6.8 standard deviation signal for a state with a mass of 10162.2 +- 1.6 MeV/c^2, consistent with the Upsilon(1D_2) assignment. We also present improved measurements of the Upsilon(3S) -> pi0 pi0 Upsilon(1S) branching ratio and the associated di-pion mass distribution.
Retrocochlear function of the peripheral deafness gene Cacna1d.
Satheesh, Somisetty V; Kunert, Katrin; Rüttiger, Lukas; Zuccotti, Annalisa; Schönig, Kai; Friauf, Eckhard; Knipper, Marlies; Bartsch, Dusan; Nothwang, Hans Gerd
2012-09-01
Hearing impairment represents the most common sensory deficit in humans. Genetic mutations contribute significantly to this disorder. Mostly, only malfunction of the ear is considered. Here, we assessed the role of the peripheral deafness gene Cacna1d, encoding the L-type channel Ca(v)1.3, in downstream processing of acoustic information. To this end, we generated a mouse conditional Cacna1d-eGFP(flex) allele. Upon pairing with Egr2::Cre mice, Ca(v)1.3 was ablated in the auditory brainstem, leaving the inner ear intact. Structural assessment of the superior olivary complex (SOC), an essential auditory brainstem center, revealed a dramatic volume reduction (43-47%) of major nuclei in young adult Egr2::Cre;Cacna1d-eGFP(flex) mice. This volume decline was mainly caused by a reduced cell number (decline by 46-56%). Abnormal formation of the lateral superior olive was already present at P4, demonstrating an essential perinatal role of Ca(v)1.3 in the SOC. Measurements of auditory brainstem responses demonstrated a decreased amplitude in the auditory nerve between 50 and 75 dB stimulation in Egr2::Cre;Cacna1d-eGFP(flex) knockout mice and increased amplitudes in central auditory processing centers. Immunohistochemical studies linked the amplitude changes in the central auditory system to reduced expression of K(v)1.2. No changes were observed for K(v)1.1, KCC2, a determinant of inhibitory neurotransmission, and choline acetyltransferase, a marker of efferent olivocochlear neurons. Together, these analyses identify a crucial retrocochlear role of Ca(v)1.3 and demonstrate that mutations in deafness genes can affect sensory cells and neurons alike. As a corollary, hearing aids have to address central auditory processing deficits as well. PMID:22678062
Entanglement teleportation through 1D Heisenberg chain
International Nuclear Information System (INIS)
Information transmission of two qubits through two independent 1D Heisenberg chains as a quantum channel is analyzed. It is found that the entanglement of two spin-12 quantum systems is decreased during teleportation via the thermal mixed state in 1D Heisenberg chain. The entanglement teleportation will be realized if the minimal entanglement of the thermal mixed state is provided in such quantum channel. High average fidelity of teleportation with values larger than 2/3 is obtained when the temperature T is very low. The mutual information I of the quantum channel declines with the increase of the temperature and the external magnetic field. The entanglement quality of input signal states cannot enhance mutual information of the quantum channel
YORP torques with 1D thermal model
Breiter, Slawomir; Czekaj, Maria
2010-01-01
A numerical model of the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect for objects defined in terms of a triangular mesh is described. The algorithm requires that each surface triangle can be handled independently, which implies the use of a 1D thermal model. Insolation of each triangle is determined by an optimized ray-triangle intersection search. Surface temperature is modeled with a spectral approach; imposing a quasi-periodic solution we replace heat conduction equation by the Helmholtz equation. Nonlinear boundary conditions are handled by an iterative, FFT based solver. The results resolve the question of the YORP effect in rotation rate independence on conductivity within the nonlinear 1D thermal model regardless of the accuracy issues and homogeneity assumptions. A seasonal YORP effect in attitude is revealed for objects moving on elliptic orbits when a nonlinear thermal model is used.
Wave Propagation in 1-D Spiral geometry
Chatterjee, Deep; Nayak, Rajesh K.
2014-01-01
In this article, we investigate the wave equation in spiral geometry and study the modes of vibrations of a one-dimensional (1-D) string in spiral shape. Here we show that the problem of wave propagation along a spiral can be reduced to Bessel differential equation and hence, very closely related to the problem of radial waves of two-dimensional (2-D) vibrating membrane in circular geometry.
Preparation of 1D nanostructures using biomolecules
Energy Technology Data Exchange (ETDEWEB)
Pruneanu, Stela; Olenic, Liliana; Kacso, Irina [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Tudoran, Lucian Barbu [Babes-Bolyai University, Electron Microscopy Center, 1 Mihail Kogalniceanu, 400006 Cluj-Napoca (Romania); Al-Said, Said A Farha; Hassanien, Reda; Houlton, Andrew; Horrocks, Benjamin R, E-mail: stela.pruneanu@itim-cj.r [School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)
2009-08-01
In this paper we have shown that one-dimensional (1D) particle arrays can be obtained using biomolecules, like DNA or amino-acids. Nano-arrays of silver and gold were prepared in a single-step synthesis, by exploiting the binding abilities of {lambda}-DNA and L-Arginine. The morphology and optical properties of these nanostructures were investigated using AFM, TEM and UV-Vis absorption spectroscopy.
Spin flop in 1D quantum antiferromagnets
International Nuclear Information System (INIS)
We review the numerical diagonalization study on the spin flop in 1D higher-S quantum spin chains in the presence of the coupling or single-ion anisotropy. The result suggested that the transition can be second-order for the system which is mapped onto the S=1/2 XXZ chain. A new result for the S=1/2 spin ladder is also presented. (author)
Superfluidity of the 1D Bose gas
Carusotto, Iacopo; Castin, Yvan
2003-01-01
We have investigated the superfluid properties of a ring of weakly interacting and degenerate 1D Bose gas at thermal equilibrium with a rotating vessel. The conventional definition of superfluidity predicts that the gas has a significant superfluid fraction only in the Bose condensed regime. In the opposite regime, it is found that a superfluid behaviour can still be identified when the probability distribution of the total momentum of the gas has a multi-peaked structure, r...
Universal nature of collective plasmonic excitations in finite 1D carbon-based nanostructures
Polizzi, Eric; Yngvesson, Sigfrid K.
2015-08-01
We provide evidence of the plasmon resonances in a number of representative 1D finite carbon-based nanostructures using first-principle computational electronic spectroscopy studies. Our special purpose real-space/real-time all-electron time-dependent density-functional theory simulator can perform excited-states calculations to obtain correct frequencies for known optical transitions, and capture various nanoscopic effects including collective plasmon excitations. The presence of 1D plasmons is universally predicted by the various numerical experiments, which also demonstrate a phenomenon of resonance splitting. For the metallic carbon nanotubes under study, the plasmons are expected to be related to the Tomonaga–Luttinger plasmons of infinitely long 1D structures. In-depth quantitative understanding of such resonances which have not been clearly identified in experiments so far, would be invaluable for future generations of nano-photonic and nano-electronic devices that employ 1D conductors.
Universal nature of collective plasmonic excitations in finite 1D carbon-based nanostructures.
Polizzi, Eric; Yngvesson, Sigfrid K
2015-08-14
We provide evidence of the plasmon resonances in a number of representative 1D finite carbon-based nanostructures using first-principle computational electronic spectroscopy studies. Our special purpose real-space/real-time all-electron time-dependent density-functional theory simulator can perform excited-states calculations to obtain correct frequencies for known optical transitions, and capture various nanoscopic effects including collective plasmon excitations. The presence of 1D plasmons is universally predicted by the various numerical experiments, which also demonstrate a phenomenon of resonance splitting. For the metallic carbon nanotubes under study, the plasmons are expected to be related to the Tomonaga-Luttinger plasmons of infinitely long 1D structures. In-depth quantitative understanding of such resonances which have not been clearly identified in experiments so far, would be invaluable for future generations of nano-photonic and nano-electronic devices that employ 1D conductors. PMID:26202877
Quantized conductance through reconfigurable 1D channels
Lu, Shicheng; Annadi, Anil; Cheng, Guanglei; Tomczyk, Michelle; Huang, Mengchen; Lee, Hyungwoo; Ryu, Sangwoo; Eom, Chang-Beom; Irvin, Patrick; Levy, Jeremy
2015-03-01
In recent years, a high mobility two-dimensional electron gas LaAlO3/SrTiO3 (LAO/STO) system has become a model system to investigate various exotic ground states of condensed matter physics. This system can co-host superconductivity, magnetism, and strong spin-orbit coupling at 2D interfaces which led to predictions of exotic phenomena such as unconventional superconductivity, helical/chiral modes, and Majorana phases in these interfaces. In order to explore these exotic phases high quality 1D devices are desirable. We demonstrate the realization of a gate tunable quantum point contact (QPC) structure embedded in a LAO/STO nanowire created using conductive AFM lithography. We observe integer quantized conductance in the units of e2 / h at high magnetic fields (B = 9 Tesla, T = 50 mK),a signature of the existence of 1D quantum channels. Significantly, we observe quantized conduction for nanowires as long as 1 ?m, implying that transport is ballistic along the magnetic-field induced chiral edge states in these devices. We gratefully acknowledge financial support from the following agencies and Grants: AFOSR (FA9550-10-1-0524 and FA9550-12-1-0268), NSF (DMR-1124131 and DMR-1104191). AFOSR FA9550-12-1-0342 (CBE) and DMR-1234096 (CBE).
A 1-D dusty plasma photonic crystal
Energy Technology Data Exchange (ETDEWEB)
Mitu, M. L.; Tico?, C. M. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Toader, D.; Banu, N.; Scurtu, A. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania); Department of Physics, University of Bucharest, 077125 Bucharest (Romania)
2013-09-21
It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 ?m to about 1350 ?m, depending on the rf power fed into the discharge.
A 1-D dusty plasma photonic crystal
Mitu, M. L.; Toader, D.; Banu, N.; Scurtu, A.; Tico?, C. M.
2013-09-01
It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 ?m to about 1350 ?m, depending on the rf power fed into the discharge.
A 1-D dusty plasma photonic crystal
International Nuclear Information System (INIS)
It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 ?m to about 1350 ?m, depending on the rf power fed into the discharge
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.
1D-1D Coulomb Drag Signature of a Luttinger Liquid
Laroche, D.; Gervais, G.; Lilly, M. P.; Reno, J. L.
2013-01-01
We report Coulomb drag measurements between vertically-integrated quantum wires separated by a barrier only 15 nm wide. The temperature dependence of the drag resistance is measured in the true one-dimensional (1D) regime where both wires have less than one 1D subband occupied. As a function of temperature, an upturn in the drag resistance is observed in three distinct devices at a temperature $T^* \\sim 1.6$ K. This crossover in Coulomb drag behaviour is consistent with Tomo...
1D-VAR Retrieval Using Superchannels
Liu, Xu; Zhou, Daniel; Larar, Allen; Smith, William L.; Schluessel, Peter; Mango, Stephen; SaintGermain, Karen
2008-01-01
Since modern ultra-spectral remote sensors have thousands of channels, it is difficult to include all of them in a 1D-var retrieval system. We will describe a physical inversion algorithm, which includes all available channels for the atmospheric temperature, moisture, cloud, and surface parameter retrievals. Both the forward model and the inversion algorithm compress the channel radiances into super channels. These super channels are obtained by projecting the radiance spectra onto a set of pre-calculated eigenvectors. The forward model provides both super channel properties and jacobian in EOF space directly. For ultra-spectral sensors such as Infrared Atmospheric Sounding Interferometer (IASI) and the NPOESS Airborne Sounder Testbed Interferometer (NAST), a compression ratio of more than 80 can be achieved, leading to a significant reduction in computations involved in an inversion process. Results will be shown applying the algorithm to real IASI and NAST data.
Haw, Magnus; Bellan, Paul
2015-04-01
A fast (100 MHz) 1D coded aperture visible light camera has been developed as a prototype for imaging plasma experiments in the EUV/X-ray bands. The system uses printed patterns on transparency sheets as the masked aperture and an 80 channel photodiode array (9 V reverse bias) as the detector. In the low signal limit, the system has demonstrated 40-fold increase in throughput and a signal-to-noise gain of ?7 over that of a pinhole camera of equivalent parameters. In its present iteration, the camera can only image visible light; however, the only modifications needed to make the system EUV/X-ray sensitive are to acquire appropriate EUV/X-ray photodiodes and to machine a metal masked aperture.
T = 0 phase diagram of 1D extended anisotropic spin- 1/2 Heisenberg model
International Nuclear Information System (INIS)
For the 1D spin-1/2 Heisenberg model with ferromagnetic nearest-neighbor interaction and antiferromagnetic next-nearest neighbor one we present the phase diagram at T = 0 as obtained by DMRG analysis. The interplay of interactions generates two massless and two massive phases in the range of parameters considered. We discuss the properties of the correlations in these phases.
1-D hybrid code for FRM dynamics
International Nuclear Information System (INIS)
A 1-D radial hybrid code has been written to study the start-up of the FRM via neutral-beam injection. This code, named FROST (Field Reversed One-dimensional STart-up), models the plasma as azimuthal symmetric with no axial dependence. A multi-group method in energy and canonical angular momentum describes the large-orbit ions from the beam. This method is designed to be more efficient than those employing particle tracking, since the characteristic timescale of the simulation is the ion slowing down time, rather than the much shorter cyclotron period. A time-differentiated Grad-Shafranov equation couples the ion current to massless fluid equations describing electrons and low energy ions. Flux coordinates are used in this fluid model, in preference to an Eulerian framework, so that coupling of plasma at the two different radii of a closed flux surface may be treated with ease. Since a fluid treatment for electrons is invalid near a field null, a separate model for the electron current has been included for this region, a unique feature. Results of simulation of injection into a 2XIIB-like plasma are discussed. Electron currents are found to retard, but not prevent reversal of the magnetic field at the plasma center
'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.
Basarir, N.; Meral Ozel, N.
2014-12-01
Marmara Region has witnessed many devastating earthquakes where some of them caused tsunami. 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, 16:58, M=6.3 Cinarcik earthquakes. The aim of this study is to contribute to the seismotectonics of this region by examining the 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 from displacement spectra of the digitized seismic waveforms. 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 ISS bulletins for the 1935 and 1963 earthquakes. 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.
On the computation of long period seismograms in a 3-D earth using normal mode based approximations
Romanowicz, Barbara A.; Panning, Mark P.; Gung, Yuancheng; Capdeville, Yann
2008-11-01
Tomographic inversions for large-scale structure of the earth's mantle involve a forward modelling step of wave propagation through 3-D heterogeneity. Until now, most investigators have worked in the framework of the simplest theoretical assumptions, namely the infinite frequency `ray theory' in the case of body wave traveltime inversions, or the `path-average' approximation (PAVA) to normal mode perturbation theory, in the case of surface waves and long-period waveforms. As interest is shifting to mapping shorter wavelength structures, the need for a more accurate theoretical account of the interaction of seismic waves with mantle heterogeneity, coupled with improvements in path coverage, has been realized. Here we discuss different levels of approximations used in the context of normal mode perturbation theory, when modelling time domain seismic waveforms. We compare the performance of asymptotic approximations, which collapse the effects of 3-D structure onto the great circle vertical plane: the 1-D PAVA and a 2-D approximation called non-linear asymptotic coupling theory (NACT), which both are zeroth order asymptotic approximations. We then discuss how off-vertical plane effects can be introduced using higher order asymptotics. These computationally efficient approximations are compared to the linear Born formalism (BORN), which computes scattering integrals over the entire surface of the sphere. We point out some limitations of this linear formalism in the case of spatially extended anomalies, and show how that can be remedied through the introduction of a non-linear term (NBORN). All these approximations are referenced to a precise 3-D numerical computation afforded by the spectral element method. We discuss simple geometries, and explore a range of sizes of anomalies compared to the wavelength of the seismic waves considered, thus illustrating the range of validity and limitations of the various approximations considered.
Energy Technology Data Exchange (ETDEWEB)
Yang, X.
1998-04-01
Large scale (up to 5 kt) chemical blasts are routinely conducted by mining and quarry industries around the world to remove overburden or to fragment rocks. Because of their ability to trigger the future International Monitoring System (IMS) of the Comprehensive Test Ban Treaty (CTBT), these blasts are monitored and studied by verification seismologists for the purpose of discriminating them from possible clandestine nuclear tests. One important component of these studies is the modeling of ground motions from these blasts with theoretical and empirical source models. The modeling exercises provide physical bases to regional discriminants and help to explain the observed signal characteristics. The program MineSeis has been developed to implement the synthetic seismogram modeling of multi-shot blast sources with the linear superposition of single shot sources. Single shot sources used in the modeling are the spherical explosion plus spall model mentioned here. Mueller and Murphy`s (1971) model is used as the spherical explosion model. A modification of Anandakrishnan et al.`s (1997) spall model is developed for the spall component. The program is implemented with the MATLAB{reg_sign} Graphical User Interface (GUI), providing the user with easy, interactive control of the calculation.
Resistance of CD1d?/? Mice to Ultraviolet-Induced Skin Cancer Is Associated with Increased Apoptosis
Matsumura, Yasuhiro; Moodycliffe, Angus M.; Nghiem, Dat X.; Ullrich, Stephen E.; Ananthaswamy, Honnavara N
2004-01-01
Inhibition of p53-induced epidermal apoptosis, generation of p53 mutations, and suppressor T cells are the critical events responsible for the induction and development of UV-induced skin cancers. Recently, we demonstrated that CD1d knockout mice were resistant to UV-induced immunosuppression, prompting us to further address the role of CD1d in regulating UV carcinogenesis. We, therefore, investigated the response of wild-type (WT) and CD1d?/? mice to UV carcinogenesis. We found that although...
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.
First Observation of a Upsilon(1D) State
Bonvicini, G; Dubrovin, M; Bornheim, A; Lipeles, E; Pappas, S P; Shapiro, A; Weinstein, A J; Briere, R A; Chen, G P; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Adam, N E; Alexander, J P; Berkelman, K; Boisvert, V; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Galik, R S; Gibbons, L; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Magerkurth, A; Mahlke-Krüger, H; Meyer, T O; Patterson, J R; Pedlar, T K; Peterson, D; Pivarski, J; Riley, D; Rosner, J L; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Sun, W M; Thayer, J G; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Potlia, V; Stöck, H; Yelton, J; Eisenstein, B I; Gollin, G D; Karliner, I; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Besson, D; Gao, K Y; Gong, D T; Kubota, Y; Li, S Z; Poling, R A; Scott, A W; Smith, A; Stepaniak, C J; Urheim, J; Metreveli, Z V; Seth, K K; Tomaradze, A G; Zweber, P; Ernst, J; Arms, K; Eckhart, E; Gan, K K; Gwon, C; Severini, H; Skubic, P L; Asner, D M; Dytman, S A; Mehrabyan, S S; Müller, J A; Nam, S; Savinov, V; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cummings, J P; Danko, I; Napolitano, J; Cronin-Hennessy, D; Park, C S; Park, W; Thayer, J B; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Haynes, J; Menaa, N; Mountain, R; Muramatsu, H; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, Kevin; Mahmood, A H; Csorna, S E
2004-01-01
We present the first evidence for the production of Upsilon(1D) states in the four-photon cascade, Upsilon(3S)-->gamma chib(2P), chib(2P)-->gamma Upsilon(1D), Upsilon(1D)-->gamma chib(1P), chib(1P)-->gamma Upsilon(1S), followed by the Upsilon(1S) annihilation into e+e- or mu+mu-. The signal has a significance of 10.2 standard deviations. The measured product branching ratio for these five decays, (2.5+-0.5+-0.5)x10^(-5), is consistent with the theoretical estimates. The data are dominated by the production of one Upsilon(1D) state consistent with the J=2 assignment. Its mass is determined to be (10161.1+-0.6+-1.6) MeV, which is consistent with the predictions from potential models and lattice QCD calculations. We also searched for Upsilon(3S)-->gammachib(2P), chib(2P)-->gammaUpsilon(1D), followed by either Upsilon(1D)-->eta Upsilon(1S) or Upsilon(1D)-->pi+pi- Upsilon(1S). We find no evidence for such decays and set upper limits on the product branching ratios.
Lifescience Database Archive (English)
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T1D in College (Type 1 Diabetes)
... Top 10 Tips for Eating Healthy in College Activism in College: How to Raise Funds and Awareness About T1D Alcohol and Type 1 Diabetes College Scholarships Available for Students with Type 1 Diabetes The Diabetes Scholars Foundation ...
T1D in School (Type 1 Diabetes)
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Malek, Jiri; Brokesova, Johana; Kolinsky, Petr
2015-04-01
We compare two independent methods of determining phase velocity of body and surface waves. The first method is based on matching the waveforms of relevant acceleration and rotation rate components derived from a small-aperture seismic array (ADR method). The second method utilizes time delays of corresponding wave phases across the small-aperture array, whereas the sufficient accuracy is reached thanks to focusing on times at which the ground velocity passes through zero value (ZPD method). Both methods are illustrated on the Jan Mayen Island earthquake of Mw 6.8 of August 30, 2012, 13:43:23 UTC as recorded in a small array installed in the vicinity of the underground gas storage Pribram-Haje, the Czech Republic. The array consists of 7 broadband stations with flat frequency response between 0.03 to 30 Hz (sensors Guralp CMG-40T). The area of the network is approximately 14 km2. The array is located about 2740 km from the epicenter of the Jan Mayen Island earthquake. Seismic rotation rate components have been calculated by the ADR method, where the applicability of the method was checked by comparing the real array records with those calculated using the first-order Taylor's expansion around central station. The acceleration seismograms have been obtained by performing the time derivative of the corresponding components in the frequency domain. The prevailing frequency of the rotational rate components is 0.08 Hz, while that of the translational components about 0.06 Hz. Very good waveform match is observed both for the transverse acceleration and vertical-axis rotational rate components as well as for the vertical acceleration and translational-axis rotational rate components. For the S-wave group, the velocity derived matching the relevant acceleration and rotational rate components is 5.87 km/s while the velocity estimated from the time delays across the array (ZPD) is 5.74 km/s; in both cases the values correspond to an apparent phase velocity along the surface. For the main surface wave group, amplitude ratios lead to phase velocity of 3.46 km/s which agrees well with the value 3.47 km/s determined using the ZPD method. When using a suitable multiple filtering, both methods allows to determine dispersion of surface-wave phase velocity.
Design, implementation and analysis of fully digital 1-D controllable multiscroll chaos
Mansingka, Abhinav S.
2011-12-01
This paper introduces the fully digital implementation of a 1-D multiscroll chaos generator based on a staircase nonlinearity in the 3rd-order jerk system using the Euler approximation. For the first time, digital design is exploited to provide real-time controllability of (i) number of scrolls, (ii) position in 1-D space, (iii) Euler step size and (iv) system parameter. The effect of variations in these fields on the maximum Lyapunov exponent (MLE) is analyzed. The system is implemented using Verilog HDL and synthesized on an Xilinx Virtex 4 FPGA, exhibiting area utilization less than 3.5% and high performance with experimentally verified throughput up to 3.33 Gbits/s. This fully digital system enables applications in modulation schemes and chaos-based cryptosystems without analog to digital conversion. © 2011 IEEE.
Pitch-based pattern splitting for 1D layout
Nakayama, Ryo; Ishii, Hiroyuki; Mikami, Koji; Tsujita, Koichiro; Yaegashi, Hidetami; Oyama, Kenichi; Smayling, Michael C.; Axelrad, Valery
2015-07-01
The pattern splitting algorithm for 1D Gridded-Design-Rules layout (1D layout) for sub-10 nm node logic devices is shown. It is performed with integer linear programming (ILP) based on the conflict graph created from a grid map for each designated pitch. The relation between the number of times for patterning and the minimum pitch is shown systematically with a sample pattern of contact layer for each node. From the result, the number of times for patterning for 1D layout is fewer than that for conventional 2D layout. Moreover, an experimental result including SMO and total integrated process with hole repair technique is presented with the sample pattern of contact layer whose pattern density is relatively high among critical layers (fin, gate, local interconnect, contact, and metal).
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).
1D EM Modeling for Onshore Hydrocarbon Detection using MATLAB
Directory of Open Access Journals (Sweden)
N.H.H.M. Hanif
2011-01-01
Full Text Available Controlled Source Electromagnetic (CSEM is a new technique used for hydrocarbons detection. This study focuses on One dimension (1D modeling of hydrocarbon detection for onshore application using the principles of electromagnetic (EM waves propagation. The transmitted frequency which is 0.25 Hz was used to characterize the hydrocarbon at 500 m, 1000 m and 1500 m. Electric fields detected by the receivers at 500, 1000 and 1500 m were 22.85, 20.4 and 17.1 V m-1, respectively which was determined by using 1D simulation. This non-seismic 1D modeling may provide alternative solution for hydrocarbon (HC detection for oil and gas industry.
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.
A computationally efficient steady-state electrode-level and 1D + 1D cell-level fuel cell model
Bao, Cheng; Bessler, Wolfgang G.
2012-07-01
Computational efficiency is highly important for upscaling detailed electrode-level and cell-level models to the system level required for the design and control of fuel cells. We present a computationally efficient 1D + 1D fuel cell model based on a combination of analytical and numerical approaches. On the electrode level, we develop approximate analytical solutions for the 1D current/potential distribution via a hybrid algorithm of power-law approach and perturbation method. Compared to the conventional perturbation method, this work keeps the intrinsic nonlinearity of electrochemical kinetics, while providing clearer physical meaning than some purely mathematical methods like the Adomian decomposition method. By integrating the resulting overpotential profile into mass transfer models, concentration overpotentials are obtained and the thermodynamic framework is then used for analyzing the H2/CO electrochemical co-oxidation kinetics. A novel expression is also presented to interconvert volume- and area-specific exchange current densities. On the cell level, a linear relationship between local current density and solid temperature is further developed for efficient 1D + 1D thermal along-the-channel numerical simulations without requiring computational iterations. Both the electrode-level and cell-level macroscopic fuel cell models are validated against full numerical solutions available in the open literatures over a wide range of operating conditions. With the hybrid analytical/numerical approximation in two dimensions, the computational framework is predicted to be sufficiently efficient for real-time simulations.
International Nuclear Information System (INIS)
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
Numerical simulation of Ge solar cells using D-AMPS-1D code
International Nuclear Information System (INIS)
A solar cell is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. When light with photon energies greater than the band gap is absorbed by a semiconductor material, free electrons and free holes are generated by optical excitation in the material. The main characteristic of a photovoltaic device is the presence of internal electric field able to separate the free electrons and holes so they can pass out of the material to the external circuit before they recombine. Numerical simulation of photovoltaic devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. The electrical transport and the optical behavior of the solar cells discussed in this work were studied with the simulation code D-AMPS-1D. This software is an updated version of the one-dimensional (1D) simulation program Analysis of Microelectronic and Photonic Devices (AMPS) that was initially developed at The Penn State University, USA. Structures such as homojunctions, heterojunctions, multijunctions, etc., resulting from stacking layers of different materials can be studied by appropriately selecting characteristic parameters. In this work, examples of cells simulation made with D-AMPS-1D are shown. Particularly, results of Ge photovoltaic devices are presented. The role of the InGaP buffer on the device was studied. Moreover, a comparison of the simulated electrical parameters with experimental results was performed.
Towards a complete classification of 1D gapped quantum phases in interacting spin systems
Chen, Xie; Wen, Xiao-Gang
2011-01-01
Quantum phases with different orders exist with or without breaking the symmetry of the system. Recently, a classification of gapped quantum phases which do not break time reversal, parity or on-site unitary symmetry has been given for 1D spin systems in [X. Chen, Z.-C. Gu, and X.-G. Wen, Phys. Rev. B 83, 035107 (2011); arXiv:1008.3745]. It was found that, such symmetry protected topological (SPT) phases are labeled by the projective representations of the symmetry group which can be viewed as a symmetry fractionalization. In this paper, we extend the classification of 1D gapped phases by considering SPT phases with combined time reversal, parity, and/or on-site unitary symmetries and also considering the possibility of symmetry breaking. In this way, we obtain a complete classification of gapped quantum phases in 1D spin systems. We find that in general, symmetry fractionalization, symmetry breaking and long range entanglement(present in 2 or higher dimensions) represent three main mechanisms to generate a v...
Numerical simulation of Ge solar cells using D-AMPS-1D code
Barrera, Marcela; Rubinelli, Francisco; Rey-Stolle, Ignacio; Plá, Juan
2012-08-01
A solar cell is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. When light with photon energies greater than the band gap is absorbed by a semiconductor material, free electrons and free holes are generated by optical excitation in the material. The main characteristic of a photovoltaic device is the presence of internal electric field able to separate the free electrons and holes so they can pass out of the material to the external circuit before they recombine. Numerical simulation of photovoltaic devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. The electrical transport and the optical behavior of the solar cells discussed in this work were studied with the simulation code D-AMPS-1D. This software is an updated version of the one-dimensional (1D) simulation program Analysis of Microelectronic and Photonic Devices (AMPS) that was initially developed at The Penn State University, USA. Structures such as homojunctions, heterojunctions, multijunctions, etc., resulting from stacking layers of different materials can be studied by appropriately selecting characteristic parameters. In this work, examples of cells simulation made with D-AMPS-1D are shown. Particularly, results of Ge photovoltaic devices are presented. The role of the InGaP buffer on the device was studied. Moreover, a comparison of the simulated electrical parameters with experimental results was performed.
Numerical simulation of Ge solar cells using D-AMPS-1D code
Energy Technology Data Exchange (ETDEWEB)
Barrera, Marcela, E-mail: barrera@tandar.cnea.gov.ar [Comision Nacional de Energia Atomica, Avenida General Paz 1499, San Martin 1650, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Rubinelli, Francisco [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC)-CONICET, Gueemes 3450, Santa Fe 3000 (Argentina); Rey-Stolle, Ignacio [Instituto de Energia Solar, Universidad Politecnica de Madrid, Avenida Complutense 30, Madrid 28040 (Spain); Pla, Juan [Comision Nacional de Energia Atomica, Avenida General Paz 1499, San Martin 1650, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)
2012-08-15
A solar cell is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. When light with photon energies greater than the band gap is absorbed by a semiconductor material, free electrons and free holes are generated by optical excitation in the material. The main characteristic of a photovoltaic device is the presence of internal electric field able to separate the free electrons and holes so they can pass out of the material to the external circuit before they recombine. Numerical simulation of photovoltaic devices plays a crucial role in their design, performance prediction, and comprehension of the fundamental phenomena ruling their operation. The electrical transport and the optical behavior of the solar cells discussed in this work were studied with the simulation code D-AMPS-1D. This software is an updated version of the one-dimensional (1D) simulation program Analysis of Microelectronic and Photonic Devices (AMPS) that was initially developed at The Penn State University, USA. Structures such as homojunctions, heterojunctions, multijunctions, etc., resulting from stacking layers of different materials can be studied by appropriately selecting characteristic parameters. In this work, examples of cells simulation made with D-AMPS-1D are shown. Particularly, results of Ge photovoltaic devices are presented. The role of the InGaP buffer on the device was studied. Moreover, a comparison of the simulated electrical parameters with experimental results was performed.
Steady 1D Stationary Currents of Spherical Gas Layer
Ivanov, Mikhail I
2012-01-01
Spherical layer of ideal gas is considered. The layer is in the sphere's gravity field. Existence possibility of steady 1D stationary currents of this layer is studied. This problem simulates zonal winds taking place in the atmospheres of some planets such as Venus, Titan, Jupiter and Saturn.
ADVANCED CONCEPTS: 1D theory of laser plasma wake
Zhu, Xiong-Wei; Gao, Jie; He, An; Li, Da-Zhang
2009-06-01
In this paper, we get the 1D approximate analytical solution of the plasma electrostatic wake driven by the laser, and get the modified oscillating frequency of this wake. Finally we analyze the longitudinal beam dynamics in this electrostatic wake, and find that the high order terms don't change the topology of the longitudinal phase space.
1D hyperspectral images of a light emitting diodes array
Urzica (Iordache), I.; Damian, V.; Logofatu, P. C.; Apostol, D.; Vasile, T.; Udrea, C.
2015-02-01
The paper present our first steps to realize a hyperspectral imaging system. Preliminary experiments in the domain have as purpose to test the capability of a monochromator with a 2D linear CCD camera, to create hyperspectral images. Using a Sciencetech 9055 model monochromator with a Hamamatsu CCD, we have analyzed an array of three LEDs of various colors, obtaining 1D hyperspectral images.
Testing the Early Mars H2-CO2 Greenhouse Hypothesis with a 1-D Photochemical Model
Batalha, Natasha; Domagal-Goldman, Shawn D.; Ramirez, Ramses; Kasting, James
2015-01-01
A recent study by Ramirez et al. (2014) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of water. Such warm temperatures appear necessary to generate the rainfall (or snowfall) amounts required to carve the ancient martian valleys. Here, we use our best estimates for early martian outgassing rates, along with a 1-D photochemical mode...
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...
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; 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.
The RabGAP TBC1D1 plays a central role in exercise-regulated glucose metabolism in skeletal muscle.
Stöckli, Jacqueline; Meoli, Christopher C; Hoffman, Nolan J; Fazakerley, Daniel J; Pant, Himani; Cleasby, Mark E; Ma, Xiuquan; Kleinert, Maximilian; Brandon, Amanda E; Lopez, Jamie A; Cooney, Gregory J; James, David E
2015-06-01
Insulin and exercise stimulate glucose uptake into skeletal muscle via different pathways. Both stimuli converge on the translocation of the glucose transporter GLUT4 from intracellular vesicles to the cell surface. Two Rab guanosine triphosphatases-activating proteins (GAPs) have been implicated in this process: AS160 for insulin stimulation and its homolog, TBC1D1, are suggested to regulate exercise-mediated glucose uptake into muscle. TBC1D1 has also been implicated in obesity in humans and mice. We investigated the role of TBC1D1 in glucose metabolism by generating TBC1D1(-/-) mice and analyzing body weight, insulin action, and exercise. TBC1D1(-/-) mice showed normal glucose and insulin tolerance, with no difference in body weight compared with wild-type littermates. GLUT4 protein levels were reduced by ?40% in white TBC1D1(-/-) muscle, and TBC1D1(-/-) mice showed impaired exercise endurance together with impaired exercise-mediated 2-deoxyglucose uptake into white but not red muscles. These findings indicate that the RabGAP TBC1D1 plays a key role in regulating GLUT4 protein levels and in exercise-mediated glucose uptake in nonoxidative muscle fibers. PMID:25576050
The RabGAP TBC1D1 plays a central role in exercise-regulated glucose metabolism in skeletal muscle
DEFF Research Database (Denmark)
Stöckli, Jacqueline; Meoli, Christopher C
2015-01-01
Insulin and exercise stimulate glucose uptake into skeletal muscle via different pathways. Both stimuli converge on the translocation of the glucose transporter GLUT4 from intracellular vesicles to the cell surface. Two Rab guanosine triphosphatases-activating proteins (GAPs) have been implicated in this process: AS160 for insulin stimulation and its homolog, TBC1D1, are suggested to regulate exercise-mediated glucose uptake into muscle. TBC1D1 has also been implicated in obesity in humans and mice. We investigated the role of TBC1D1 in glucose metabolism by generating TBC1D1(-/-) mice and analyzing body weight, insulin action, and exercise. TBC1D1(-/-) mice showed normal glucose and insulin tolerance, with no difference in body weight compared with wild-type littermates. GLUT4 protein levels were reduced by ?40% in white TBC1D1(-/-) muscle, and TBC1D1(-/-) mice showed impaired exercise endurance together with impaired exercise-mediated 2-deoxyglucose uptake into white but not red muscles. These findings indicate that the RabGAP TBC1D1 plays a key role in regulating GLUT4 protein levels and in exercise-mediated glucose uptake in nonoxidative muscle fibers.
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.
Electromagnetic absorption of quasi-1D Majorana nanowires
Osca, Javier; Serra, Llorenç
2015-01-01
We calculate the electromagnetic absorption cross section of long and narrow nanowires, in the so-called quasi-1D limit. We consider only two transverse bands and compute the dipole absorption cross section taking into account quasiparticle transitions from negative to positive energy eigenstates of the Bogoliubov-de Gennes Hamiltonian. The presence of the zero energy (Majorana) state manifests in the different absorption spectra for $x$ (parallel) and $y$ (transverse) polar...
Towards a reasoned 1-D river model calibration
Vidal, J.P.; Moisan, S.; Faure, J.B.; Dartus, D.
2005-01-01
Le calage de modèle reste une étape critique de la modélisation numérique. Après de nombreuses tentatives d`automatisation de cette tâche dans différentes domaines liés à l`eau, des questions se posent encore sur la nécessité de caler des modèles à base physique. Cet article propose aux utilisateurs de codes de calcul en hydraulique un cadre pour réaliser cette tâche selon un « code de bonnes pratiques ». Ce cadre comporte une formalisation des objets manipulés en hydraulique fluviale 1-D ain...
Overview remarks on homogeneous N = 1, d = 11 supergravity cosmologies
International Nuclear Information System (INIS)
The dynamics of the full class of homogeneous N = 1, d = 11 supergravity world models is investigated. By using the classification of Lie algebras of Lie groups which act simply transitively on 6- and 7-dimensional compact spaces some conclusions are drawn concerning the non-existence of the chaotic regime near the singularity. This is illustrated with some new solutions having a richer structure of the microspace. The significance of known solutions is briefly discussed. 25 refs., 1 fig., 1 tab. (author)
Spatial stochastic resonance in 1D Ising systems
Neda, Z; Ravasz, E; Lakdawala, P; Gade, P M
1999-01-01
The 1D Ising model is analytically studied in a spatially periodic and oscillatory external magnetic field using the transfer-matrix method. For low enough magnetic field intensities the correlation between the external magnetic field and the response in magnetization presents a maximum for a given temperature. The phenomenon can be interpreted as a resonance phenomenon induced by the stochastic heatbath. This novel "spatial stochastic resonance" has a different origin from the classical stochastic resonance phenomenon.
Spatial stochastic resonance in 1D Ising systems
Neda, Z.; Rusz, A.; Ravasz, E.; Lakdawala, P.; Gade, P. M.
1999-01-01
The 1D Ising model is analytically studied in a spatially periodic and oscillatory external magnetic field using the transfer-matrix method. For low enough magnetic field intensities the correlation between the external magnetic field and the response in magnetization presents a maximum for a given temperature. The phenomenon can be interpreted as a resonance phenomenon induced by the stochastic heatbath. This novel "spatial stochastic resonance" has a different origin from ...
Electronic properties of the 1D Frenkel-Kontorova model
Tong, Peiqing; Li, Baowen; Hu, Bambi
2002-01-01
The energy spectra and quantum diffusion of an electron in a 1D incommensurate Frenkel-Kontorova (FK) model are studied numerically. We found that the spectral and dynamical properties of electron display quite different behaviors in invariance circle regime and in Cantorus regime. In the former case, it is similar to that of the Harper model, whereas in the latter case, it is similar to that of the Fibonacci model. The relationship between spectral and transport properties ...
Quantitative 1D saturation profiles on chalk by NMR.
DEFF Research Database (Denmark)
Olsen, Dan; Topp, Simon
1996-01-01
Quantitative one-dimensional saturation profiles showing the distribution of water and oil in chalk core samples are calculated from NMR measurements utilizing a 1D CSI spectroscopy pulse sequence. Saturation profiles may be acquired under conditions of fluid flow through the sample. Results reveal that strong saturation gradients exist in chalk core samples after core floods, due to capillary effects. The method is useful in analysis of corefloods, e.g., for determination of capillary pressure functions
Blind Detection of Severely Blurred 1D Barcode
Dridi, Noura; Delignon, Yves; Sawaya, Wadih; Septier, François
2010-01-01
In this paper, we present a joint blind channel estimation and symbol detection for decoding a blurred and noisy 1D barcode captured image. From an information transmission point of view, we show that the channel impulse response, the noise power and the symbols can be efficiently estimated by taking into account the signal structure such as the cyclostationary property of the hidden Markov process to estimate. Based on the Expectation-Maximisation method, we show that the new algorithm offer...
Waves in a 1D electrorheological dusty plasma lattice
Rosenberg, M.
2015-08-01
The behavior of waves in a one-dimensional (1D) dusty plasma lattice where the dust interacts via Yukawa and electric dipole interactions is discussed theoretically. This study is motivated by recent reports on electrorheological dusty plasmas (e.g. Ivlev et al. 2008 Phys. Rev. Lett. 100, 095003) where the dipole interaction arises due to an external uniaxial AC electric field that distorts the Debye sphere surrounding each grain. Application to possible dusty plasma experimental parameters is discussed.
International Nuclear Information System (INIS)
Typically, a Pressure Control Valve (PCV) system is constructed with 3 to 4 PCV lines in order to prepare for both a future demand increase and a continuous supply of power after an emergency shutdown of the operating line. However, some operation failure cases that do not follow the original design concepts of a PCV system have been reported in the field. In this study, an accurate 1-D PCV system numerical model was built and a 1-D compressible flow theory was introduced for analytic valve modeling to find solutions for this problem. Several numerical analyses were successfully performed to examine the generation and propagation characteristics of the transient pressure and to clarify the relationships between the transient pressure or surge wave and each factor or parameter relating to fluid dynamics behavior in a PCV system. The relationship between the transient pressure and other factors, such as the size of pipe and header linked after a PCV, the pipe size of the added components linked after the header, and the generation time of the transient pressure and influence of the Slam Shut Valve were investigated in detail. Finally, in order to reduce the strength of the transient pressure and to delay its propagation, this study demonstrates the benefit both of enlargement of the pipe linked to the component added after the PCV system, and the installation of a dissipation component between the operation line and the other lines
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)
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)
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.
Guo, Kangzhu; Ou, Haijiang; Grycewicz, Thomas; Joshi, Abhay; Wang, Xinde; Thomas, Gordon; Wang, Haimin; Greene, Richard; Misra, Durga; Liu, Sheng; Liu, Zhiwei; Zhen, Jianjun; Wang, Xiaodong; Li, Baoqing; Xiao, Zhixiong; Ciampa, Nicholas A.; Opyrchal, Jan; Opyrchal, Halina; Chin, Ken K.
2004-08-01
A 1D IR lock-in focal plane array (FPA) for extremely weak signal imaging has been demonstrated. The experimental system consists of an object with modulated image signal, a high speed InGaAs linear photodetector array as receiver, a CMOS lock-in linear array read-out circuit, and a focal plane array test system. The system can detect extremely weak signals immersed in strong background. Preliminary test shows that under room temperature each of the pixels in the 1D lock-in FPA can read out modulated signal 5 orders smaller than the background. The InGaAs detector array response is from 0.8 ?m to 1.6 ?m (peak at 1.2 ?m). The lock-in array read-out circuit uses a correlated multi-cycle integrator, which can operate in several modes such as gated integration, and phase-sensitive integration with background subtraction. The 1D lock-in FPA works as a pixel to pixel lock-in amplifier, wherein very small signals may be extracted from a much strong background if the frequency of the illuminating source (usually IR light sources) is known. Simulation results are also reported. Experimental results based on an IR illuminating source are demonstrated.
Karabash, Illya M.
2011-01-01
The paper is devoted to optimization of resonances associated with 1-D wave equations in inhomogeneous media. The medium's structure is represented by a nonnegative function B. The problem is to design for a given $\\alpha \\in \\R$ a medium that generates a resonance on the line $\\alpha + \\i \\R$ with a minimal possible modulus of the imaginary part. We consider an admissible family of mediums that arises in a problem of optimal design for photonic crystals. This admissible fam...
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.
Nonultralocal Quantum Algebra and 1D Anyonic Quantum Integrable Models
International Nuclear Information System (INIS)
Applying braided Yang-Baxter equation quantum integrable and Bethe ansatz, solvable 1D anyon lattice and field models are constructed. Along with known models we discover novel lattice anyon and q-anyon models as well as nonlinear Schoedinger equation (NLS) and the derivative NLS anyon quantum field models, N-particle sectors of which yield the well-known anyon gases, interacting through ? and derivative ? function potentials. As a byproduct we discover a new anyon quantum group Hopf algebra with unusual braided multiplication. (author)
Nanofluidic sustainable energy conversion using a 1D nanofluidic network.
Kim, Sang Hui; Kwak, Seungmin; Han, Sung Il; Chun, Dong Won; Lee, Kyu Hyoung; Kim, Jinseok; Lee, Jeong Hoon
2014-05-01
We propose a 1-dimensional (1D) nanofluidic energy conversion device by implementing a surface-patterned Nafion membrane for the direct energy conversion of the pressure to electrical power. By implementing a -200-nm-thick nano-bridge with a 5-nm pore size between two microfluidic channels, we acquired an effective streaming potential of 307 mV and output power of 94 pW with 0.1 mM KCI under pressure difference of 45 MPa. The experimental results show both the effects of applied pressure differences and buffer concentrations on the effective streaming potential, and are consistent with the analytical prediction. PMID:24734635
Spatial coherence of polaritons in a 1D channel
International Nuclear Information System (INIS)
We analyze time evolution of spatial coherence of a polariton ensemble in a quantum wire (1D channel) under constant uniform resonant pumping. Using the theoretical approach based on the Lindblad equation for a one-particle density matrix, which takes into account the polariton-phonon and excitonexciton interactions, we study the behavior of the first-order coherence function g1 for various pump intensities and temperatures in the range of 1–20 K. Bistability and hysteresis in the dependence of the first-order coherence function on the pump intensity is demonstrated.
TOF-2: a large 1D channel thorium organic framework.
Ok, KM; Sung, J; Hu, G.; Jacobs, RM; O'Hare, D.
2008-01-01
A new neutral 1D channel thorium organic framework material (TOF-2) has been synthesized under hydrothermal conditions. TOF-2 exhibits a hexagonal channel structure consisting of eight-coordinate ThO6F2 polyhedra and 1,3,5-benzentricarboxylate ligands. The channels run along the c-axis and are approximately 13 A in diameter. The single-crystal X-ray structure suggests that the amount of void space is 41%. The structure is stable to ca. 400 degrees C. Gas adsorption measurements show deferenti...
Effects of periodic gate potentials on quasi-1 D excitons
International Nuclear Information System (INIS)
Optical properties of Quasi-1D excitons in a Ga As-Al Ga As quantum well and confined by lateral field effect induced superlattice potentials are investigated. A variational approach is used to calculate the binding energies Eex and absorption coefficient ?ex of these excitonic transitions as functions of the applied voltage and period of the induced superlattice potential. A competition between confinement and Coulomb attraction produce strong oscillations on Eex and ?ex which should be observed experimentally. (author). 8 refs., 1 fig
Effects of periodic gate potentials on quasi-1 D excitons
Energy Technology Data Exchange (ETDEWEB)
Cocoletzi, Gregorio H. [Universidad Autonoma de Puebla (Mexico). Inst. de Fisica; Ulloa, Sergio E. [Ohio Univ., Athens, OH (United States). Dept. of Physics and Astronomy
1996-03-01
Optical properties of Quasi-1D excitons in a Ga As-Al Ga As quantum well and confined by lateral field effect induced superlattice potentials are investigated. A variational approach is used to calculate the binding energies E{sub ex} and absorption coefficient {alpha}{sub ex} of these excitonic transitions as functions of the applied voltage and period of the induced superlattice potential. A competition between confinement and Coulomb attraction produce strong oscillations on E{sub ex} and {alpha}{sub ex} which should be observed experimentally. (author). 8 refs., 1 fig.
Magnetic polarons in doped 1D antiferromagnetic chain
I. González; De Castro, J.; Baldomir, D.; Sboychakov, A. O.; Rakhmanov, A.L.; K. I. Kugel
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...
1D EM Modeling for Onshore Hydrocarbon Detection using MATLAB
N.H.H.M. Hanif; Shafie, A; S. Brahim; H. Daud; M. Kashif; M.N Akhtar; N.B. Yahya; H.M. Zaid; A.A.B. Zorkepli
2011-01-01
Controlled Source Electromagnetic (CSEM) is a new technique used for hydrocarbons detection. This study focuses on One dimension (1D) modeling of hydrocarbon detection for onshore application using the principles of electromagnetic (EM) waves propagation. The transmitted frequency which is 0.25 Hz was used to characterize the hydrocarbon at 500 m, 1000 m and 1500 m. Electric fields detected by the receivers at 500, 1000 and 1500 m were 22.85, 20.4 and 17.1 V m-1, respectively which was determ...
Spin structure function of deuteron g1 d from COMPASS
International Nuclear Information System (INIS)
New results on the longitudinal inclusive spin asymmetry A1 d in the range 122 and 0.0041 d which we use to evaluate the scale-invariant flavor-singlet axial charge a0. The contribution of the measured region is evaluated by a QCD fit of the world data. The data were obtained by the COMPASS experiment at CERN using a 160GeV polarized muon beam scattered off a large double-cell polarized 6LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region x<0.03. (orig.)
A 1D Ising model for ripple formation
International Nuclear Information System (INIS)
A 1D Ising model is shown to reproduce qualitatively the dynamics of ripple formation. The saltation effect is imposed using a Kawasaki dynamics and a pair interaction over some distance l. Within this model, the ripple state turns out to be metastable, in agreement with cellular automata simulations as well as recent underwater experiments. A dynamical phase diagram is obtained. A mean-field solution of the problem is given in terms of the ripple size. A mapping is then performed onto a 2D l x ? static problem. (author)
A Diamagnetic Trap with 1D Camelback Potential
Gunawan, Oki
2014-01-01
The ability to trap matter is of great importance in experimental physics since it allows isolation and measurement of intrinsic properties of the trapped matter. We present a study of a three dimensional (3D) trap for a diamagnetic rod in a pair of diametric cylindrical magnets. This system yields a fascinating 1D camelback potential along the longitudinal axis which is one of the elementary model potentials of interest in physics. This potential can be tailored by controlling the magnet length/radius aspect ratio. We developed theoretical models and verify them with experiments using graphite rods. We show that, in general, a camelback field or potential profile exists in between a pair of parallel linear dipole distribution. By exploiting this potential, we demonstrate a unique and simple technique to determine the magnetic susceptibility of the rod. This system could be further utilized as a platform for custom-designed 1D potential, a highly sensitive force-distance transducer or a trap for semiconductor...
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.
A simple quasi-1D model of Fibonacci anyons
Aasen, David; Mong, Roger; Clarke, David; Alicea, Jason; Fendley, Paul
2015-03-01
There exists various ways of understanding the topological properties of Ising anyons--from simple free-fermion toy models to formal topological quantum field theory. For other types of anyons simple toy models rarely exist; their properties have to be obtained using formal self-consistency relations. We explore a family of gapped 1D local bosonic models that in a certain limit become trivial to solve and provide an intuitive picture for Fibonacci anyons. One can interpret this model as a quasi-1D wire that forms the building block of a 2D topological phase with Fibonacci anyons. With this interpretation all topological properties of the Fibonacci anyons become manifest including ground state degeneracy and braid relations. We conjecture that the structure of the model is protected by an emergent symmetry analogous to fermion parity. 1) NSF Grant DMR-1341822 2) Institute for Quantum Information and Matter, an NSF physics frontier center with support from the Moore Foundation. 3) NSERC-PGSD.
Modeling atrazine transport in soil columns with HYDRUS-1D
Directory of Open Access Journals (Sweden)
John Leju CELESTINO LADU
2011-09-01
Full Text Available Both physical and chemical processes affect the fate and transport of herbicides. It is useful to simulate these processes with computer programs to predict solute movement. Simulations were run with HYDRUS-1D to identify the sorption and degradation parameters of atrazine through calibration from the breakthrough curves (BTCs. Data from undisturbed and disturbed soil column experiments were compared and analyzed using the dual-porosity model. The study results show that the values of dispersivity are slightly lower in disturbed columns, suggesting that the more heterogeneous the structure is, the higher the dispersivity. Sorption parameters also show slight variability, which is attributed to the differences in soil properties, experimental conditions and methods, or other ecological factors. For both of the columns, the degradation rates were similar. Potassium bromide was used as a conservative non-reactive tracer to characterize the water movement in columns. Atrazine BTCs exhibited significant tailing and asymmetry, indicating non-equilibrium sorption during solute transport. The dual-porosity model was verified to best fit the BTCs of the column experiments. Greater or lesser concentration of atrazine spreading to the bottom of the columns indicated risk of groundwater contamination. Overall, HYDRUS-1D successfully simulated the atrazine transport in soil columns.
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.
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.
Effective-range signatures in quasi-1D matter waves: sound velocity and solitons
Sgarlata, F.; Mazzarella, G.; Salasnich, L.
2015-06-01
We investigate ultracold and dilute bosonic atoms under strong transverse harmonic confinement using a 1D modified Gross–Pitaevskii equation (1D MGPE), which accounts for the energy dependence of the two-body scattering amplitude within an effective-range expansion. We study sound waves and solitons of the quasi-1D system, comparing the 1D MGPE results with the 1D GPE ones. We find that when the finite-size nature of the interaction is taken into account, the speed of sound and the density profiles of both dark and bright solitons show relevant quantitative changes with respect to predictions given by the standard 1D GPE.
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.
DEFF Research Database (Denmark)
Treebak, Jonas T; 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 phospho-sites that (1) did not respond to exercise or postprandial increase in insulin (TBC1D4: S666), (2) responded to insulin only (TBC1D4: S318), (3) responded to exercise only (TBC1D1: S237, S660, S700; TBC1D4: S588, S751), and (4) responded to both insulin and exercise (TBC1D1: T596; TBC1D4: S341, T642, S704). In the insulin-stimulated leg, Akt phosphorylation of both T308 and S473 correlated significantly with multiple sites on both TBC1D1 (T596) and TBC1D4 (S318, S341, S704). Interestingly, in the exercised leg in the fasted state TBC1D1 phosphorylation (S237, T596) correlated significantly with the activity of the ?2/?2/?3 AMPK trimer, whereas TBC1D4 phosphorylation (S341, S704) correlated with the activity of the ?2/?2/?1 AMPK trimer. Our data show differential phosphorylation of TBC1D1 and TBC1D4 in response to physiological stimuli in human skeletal muscle and support the idea that Akt and AMPK are upstream kinases. TBC1D1 phosphorylation signatures were comparable between in vitro contracted mouse skeletal muscle and exercised human muscle, and we show that AMPK regulated phosphorylation of these sites in mouse muscle. Contraction and exercise elicited a different phosphorylation pattern of TBC1D4 in mouse compared with human muscle, and although different circumstances in our experimental setup may contribute to this difference, the observation exemplifies that transferring findings between species is problematic.
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.
Effective theory of Black Holes in the 1/D expansion
Emparan, Roberto; Suzuki, Ryotaku; Tanabe, Kentaro; Tanaka, Takahiro
2015-01-01
The gravitational field of a black hole is strongly localized near its horizon when the number of dimensions D is very large. In this limit, we can effectively replace the black hole with a surface in a background geometry (eg Minkowski or Anti-deSitter space). The Einstein equations determine the effective equations that this 'black hole surface' (or membrane) must satisfy. We obtain them up to next-to-leading order in 1/D for static black holes of the Einstein-(A)dS theory. To leading order, and also to next order in Minkowski backgrounds, the equations of the effective theory are the same as soap-film equations, possibly up to a redshift factor. In particular, the Schwarzschild black hole is recovered as a spherical soap bubble. Less trivially, we find solutions for 'black droplets', ie black holes localized at the boundary of AdS, and for non-uniform black strings.
Quasi-1D excitons in lateral induced superlattices.
Cocoletzi, Gregorio H.; Hernández de La Luz, Alvaro D.; Ulloa, Sergio E.
1998-03-01
Effects of electrostatic-potential-induced lateral superlattices on the optical properties of quasi-1D excitons in GaAs-AlGaAs quantum wells are investigated. Variational estimations are presented, in the tight binding limit, of minibands, binding energies E_ex and absorption coefficients ?_ex of the ground state and first excited state of heavy-hole excitonic transitions as functions of the applied electrostatic potentials and the period of induced superlattices. The limit of small periods and high electrostatic potential produces strong confinement, and consequently, this polarizes the excitons, resembling a type II superlattice where electrons and holes are spatially separated in different potential wells. The variations of the period induce strongh oscillations on E_ex and ?_ex as a result of a competition between quantum structural confinement and Coulomb interactions.
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
1-D array of perforated diode neutron detectors
International Nuclear Information System (INIS)
Performance of a 4 cm long 64-pixel perforated diode neutron detector array is compared with an identical array of thin-film coated diodes. The perforated neutron detector design has been adapted to a 1-D pixel array capable of 120 ?m spatial resolution and counting efficiency greater than 12%. Deep vertical trenches filled with 6LiF provide outstanding improvement in efficiency over thin-film coated diode designs limited to only 4.5%. This work marks the final step towards the construction of a much larger array consisting of 1024 pixels spanning 10 cm. The larger detector array will be constructed with a sub-array of 64-pixel sensors, and will be used for small-angle neutron scattering experiments at the Spallation Neutron Source of Oak Ridge National Laboratory.
Microlens Masses from 1-D Parallaxes and Heliocentric Proper Motions
Gould, Andrew
2014-01-01
One-dimensional (1-D) microlens parallaxes can be combined with heliocentric lens-source relative proper motion measurements to derive the lens mass and distance, as suggested by Ghosh et al. (2004). Here I present the first mathematical anlysis of this procedure, which I show can be represented as a quadratic equation. Hence, it is formally subject to a two-fold degeneracy. I show that this degeneracy can be broken in many cases using the relatively crude 2-D parallax information that is often available for microlensing events. I also develop an explicit formula for the region of parameter space where it is more difficult to break this degeneracy. Although no mass/distance measurements have yet been made using this technique, it is likely to become quite common over the next decade.
Effective theory of black holes in the 1/D expansion
Emparan, Roberto; Shiromizu, Tetsuya; Suzuki, Ryotaku; Tanabe, Kentaro; Tanaka, Takahiro
2015-06-01
The gravitational field of a black hole is strongly localized near its horizon when the number of dimensions D is very large. In this limit, we can effectively replace the black hole with a surface in a background geometry (e.g. Minkowski or Anti-deSitter space). The Einstein equations determine the effective equations that this `black hole surface' (or membrane) must satisfy. We obtain them up to next-to-leading order in 1/ D for static black holes of the Einstein-(A)dS theory. To leading order, and also to next order in Minkowski backgrounds, the equations of the effective theory are the same as soap-film equations, possibly up to a redshift factor. In particular, the Schwarzschild black hole is recovered as a spherical soap bubble. Less trivially, we find solutions for `black droplets', i.e. black holes localized at the boundary of AdS, and for non-uniform black strings.
1 D Simulation of Capacitively Coupled Water Vapor Plasma
Kechidi, Ziane; A. H. Belbachir Team; M. Announ Collaboration; W. W. Graham Collaboration
2015-03-01
The results of a 1D simulation of a capacitively coupled water vapor discharge is reported. The simulated plasma consists of two electrodes separated by gap distance of 1 mm operating at 13.56 MHz with 26 species and 62 dominant reaction channels. The input parameters under which the plasma can be created is explored and space and time profiles of the electron densities are presented. The model finds that plasma ignition cannot be obtained in the present configuration and at pressures of greater than 0.1 atmosphere. The model has also be used to demonstrate the impact of rotational and vibrational excitation of water molecules in suppressing electrical breakdown. Phd student and Assistant professor
Havlickova, E; Subba, F; Coster, D; Wischmeier, M; Fishpool, G
2013-01-01
A 1D code modelling SOL transport parallel to the magnetic field (SOLF1D) is benchmarked with 2D simulations of MAST-U SOL performed via the SOLPS code for two different collisionalities. Based on this comparison, SOLF1D is then used to model the effects of divertor leg stretching in 1D, in support of the planned Super-X divertor on MAST. The aim is to separate magnetic flux expansion from volumetric power losses due to recycling neutrals by stretching the divertor leg either vertically or radially.
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.
Scandalously Parallelizable Mesh Generation
Bortz, David; Christlieb, Andrew
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 u...
1D and 3D resistivity inversions for geotechnical investigation
International Nuclear Information System (INIS)
The resistivity method is frequently used in the investigation of the shallow parts of the earth. Interpretation of such data is usually done assuming a layered earth. However, a more complete imaging can be obtained if 3D models are used. Thirty-five vertical electrical soundings (VES) were carried out in a regular mesh at the northwestern part of Greater Cairo in order to characterize different geological units and to study their quality for building foundations. Models obtained from 1D inversion of each VES, together with borehole information, were used for construction of eight geoelectrical sections which exhibit the main geoelectrical characteristics of the geological units present in the area. The 3D inversion of the data indicated a complex subsurface electrical resistivity distribution conditioned by lithology, water content and tectonic structures. The results indicate that the subsurface consists of different geologic units such as gravel and sand, sand, clay and limestone. The main results are related to the characterization of the clay formations in the north of the survey area, which is revealed by low-resistivity values (600 ? m) depicted in the central part of the study zone
A 1-D hybrid code for FRM dynamics
International Nuclear Information System (INIS)
A 1-D radial hybrid code has been written to study the start-up of the FRM via neutral-beam injection. This code, named FROST (Field Reversed One-dimensional STart-up), models the plasma as azimuthal symmetric with no axial dependence. A multi-group method in energy and canonical angular momentum describes the large-orbit ions from the beam. This method is designed to be more efficient than those employing particle tracking, since the characteristic timescale of the simulation is the ion slowing down time, rather than the much shorter cyclotron period. A time-differentiated Grad-Shafranov equation couples the ion current to massless fluid equations describing electrons and low energy ions. Flux coordinates are used in this fluid model, in preference to an Eulerian framework, so that coupling of plasma at the two different radii of a closed flux surface may be treated with ease. Since a fluid treatment for electrons is invalid near a field null, a separate model for the electron current has been included for this region, a unique feature. Results of simulation of injection into a 2XIIB-like plasma is discussed. Electron currents are found to retard, but not prevent reversal of the magnetic field at the plasma center
Nanowires and 1D arrays fabrication: An overview
International Nuclear Information System (INIS)
Since the discovery of M41S materials family in 1992, some special features like aligned pores perpendicularly to the substrate surface and long range order, have been looked for with great interest for many applications of these kind of nanomaterials. The growth of thin films displaying meso- and nano-porous structures have attracted the attention of many research groups in the last decade and, with that aim several techniques such as: MBE, CVD, AFM, ion beam lithography, etc., have been used. On the other hand, a lot of down-top techniques, particularly those in which, self-assembly processes play a relevant role in the growth mechanisms of that nanostructures have been reported. Among them, electrochemical techniques constitute one of the most used to fabricate highly ordered nanostructures to be used as templates for replicating other nanostructured materials and for growing functionalized material arrays. In this paper, a brief overview on the nanofabrication techniques is done mainly of those related with the nanowires and, in general, 1D nanostructures fabrication. In addition, we show some results on ordered and disordered nanoporous anodic alumina membranes (AAM) and anodic titania membranes (ATM), respectively. Besides some functionalized systems based on these membranes used as templates are presented such as, magnetic nanowire arrays, biosensors, and carbon nanotubes. The potentiality of these systems for applications on diverse field, such as, nanoelectronic, magneto-optic, biotechnology and optoelectronic is demonstrated
Control and imaging of O(1D2) precession
Wu, Shiou-Min; Radenovic, Dragana ?.; van der Zande, Wim J.; Groenenboom, Gerrit C.; Parker, David H.; Vallance, Claire; Zare, Richard N.
2011-01-01
Larmor precession of a quantum mechanical angular momentum vector about an applied magnetic field forms the basis for a range of magnetic resonance techniques, including nuclear magnetic resonance spectroscopy and magnetic resonance imaging. We have used a polarized laser pump-probe scheme with velocity-map imaging detection to visualize, for the first time, the precessional motion of a quantum mechanical angular momentum vector. Photodissociation of O2 at 157 nm provides a clean source of fast-moving O(1D2) atoms, with their electronic angular momentum vector strongly aligned perpendicular to the recoil direction. In the presence of an external magnetic field, the distribution of atomic angular momenta precesses about the field direction, and polarization-sensitive images of the atomic scattering distribution recorded as a function of field strength yield ‘time-lapse-photography’ style movies of the precessional motion. We present movies recorded in various experimental geometries, and discuss potential consequences and applications in atmospheric chemistry and reaction dynamics.
Three-field modeling for MARS 1-D code
International Nuclear Information System (INIS)
In this study, the three-field modeling of the two-phase mixture is developed. The finite difference equations for the three-field equations thereafter are devised. The solution scheme has been implemented into the MARS 1-D code. The three-field formulations adopted are similar to those for MARS 3-D module, in a sense that the mass and momentum are treated separately for the entrained liquid and continuous liquid. As in the MARS-3D module, the entrained liquid and continuous liquid are combined into one for the energy equation, assuming thermal equilibrium between the two. All the non-linear terms are linearized to arrange the finite difference equation set into a linear matrix form with respect to the unknown arguments. The problems chosen for the assessment of the newly added entrained field consist of basic conceptual tests. Among the tests are gas-only test, liquid-only test, gas-only with supplied entrained liquid test, Edwards pipe problem, and GE level swell problem. The conceptual tests performed confirm the sound integrity of the three-field solver
Simplified 1D modelling of the HGA test
International Nuclear Information System (INIS)
Document available in extended abstract form only. The HGA test is located in the Mont Terri Rock Laboratory (Switzerland). It consists of a horizontal borehole of 1.00 m of diameter and 13.00 m of length excavated in the ultra-low permeable Opalinus clay. During the tunnel drilling, the Opalinus clay near the tunnel wall was damaged, giving rise to an EDZ (Excavation Damaged Zone) around the tunnel. A steel liner was placed along the 6.00 m close to the tunnel mouth in order to guarantee the stability. The last 4.00 m at the tunnel end were backfilled with gravel. Along the remaining 3.00 m, an inflatable rubber packer of 1.00 m in diameter, was installed and inflated, thereby compressing the EDZ that was created during the tunnel excavation. The test section was filled with de-aired water and care was taken in order to eliminate the air from this tunnel section. Subsequently, a series of water and gas injection tests were carried out with varying mega-packer pressure, whereby water or gas was injected into the test section and, due to the very low permeability of the intact Opalinus clay, forced to flow back along the EDZ. In order to model the water and gas flow through the EDZ, we have followed a two-track approach. On the one hand, a 2D axisymmetric numerical model using code-bright has been made. On the other hand, a 1D analytical-numerical model has been developed and implemented in an Excel spreadsheet, whereby the field equations defined on a 1D geometrical domain are numerically solved using the finite element method. The 1D model has been used in order to calibrate the 2D axisymmetric model. Both the Opalinus clay and the EDZ will be considered to be porous media, with an incompressible solid phase (clay), an incompressible liquid phase (water and air) and a gas phase (water and air). The properties of the liquid phase will be assumed to be independent of the concentration of dissolved air and the gas phase will be assumed to be a mixture of dry air and water vapour, both assumed to be ideal gases, such that Dalton's law holds. Exchanges of both species water and species air between the liquid phase and the gas phase will be allowed, but it will be assumed that they are always in equilibrium, defined by the psychrometric and Henry's laws. It will be assumed that motions are slow so that terms involving accelerations and products of velocities may be neglected. Motion of the liquid phase and of the gas phase will be described by generalisations of Darcy's laws appropriate to unsaturated porous media and motion of the species water and the species air in the liquid phase and in the gas phase will be described by Fick's laws. In the Opalinus clay the intrinsic permeability will be assumed to be constant, but in the EDZ it will be assumed that it depends on the volumetric deformation of the solid skeleton via an aperture-based cubic law. A generalised form of Terzaghi's effective stress principle will be assumed to hold both in saturated and in unsaturated conditions. The constitutive laws for generalised effective stress both the Opalinus clay and the EDZ will be assumed to be given by isotropic linear elasticity. A water retention curve will govern the degree of saturation of the porous medium and, in particular, the transition between saturated and unsaturated states. Finally, it will be assumed that temperature remains constant everywhere. By combining the balance equations, the equilibrium restrictions and the constitutive relations, we get the field equations, that with suitable initial and boundary conditions allow to determine the unknown functions of the space position and time. In the considered case of the HGA test, we have considered simplifying assumptions that greatly reduce the complexity of the field equations. Mechanical assumptions: (1) there is axisymmetry about the tunnel axis; (2) there are no volume forces; and (3) slices z = const move independently and in plane strain. Hydraulic assumptions: (1) there is axisymmetry about the tunnel axis; and (2) there are no volume forces. Furthermore, on
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...
Anti-tumor Potential of Type-I NKT cells against CD1d-positive and CD1d-negative Tumors in Humans
Metelitsa, Leonid S.
2010-01-01
V?24-invariant Natural Killer T cells (NKTs) are strictly CD1d-restricted, and CD1d expression has been found in several types of leukemia and lymphoma as well as in brain tumors suggesting that these malignancies could be targeted for direct NKT-cell cytotoxicity. Several studies have revealed strong positive associations between the numbers of tumor-infiltrating or circulating NKTs with improved disease outcome in patients with diverse types of CD1d-negative solid tumors. The mechanism by w...
Multiparticle systems in ? -Poincaré inspired by (2 +1 )D gravity
Kowalski-Glikman, Jerzy; Rosati, Giacomo
2015-04-01
Inspired by a Chern-Simons description of 2 +1 -dimensional gravity coupled to point particles we propose a new Lagrangian of a multiparticle system living in ? -Minkowski/? -Poincaré spacetime. We derive the dynamics of interacting particles with ? -momentum space, alternative to the one proposed in the "principle of relative locality" literature. The model that we obtain takes account of the nonlocal topological interactions between the particles, so that the effective multiparticle action is not a sum of their free actions. In this construction the locality of particle processes is naturally implemented, even for distant observers. In particular a particle process is characterized by a local deformed energy-momentum conservation law. The spacetime transformations are generated by total charges/generators for the composite particle system, and leave unaffected the locality of individual particle processes.
Radiative lifetime measurement of the 3 1S, 3 1D, 4 1D, 4 1F, and 5 1F excited states of helium
International Nuclear Information System (INIS)
The lifetimes of the 3 1S, 3 1D, 4 1D, 4 1F, and 5 1F states of He have been determined experimentally to be 54.5 +- 0.8, 16.7 +- 0.8, 36.4 +- 1.2, 67 +- 10, and 142 +- 20 nesc, respectively. The measurements were made at several incident electron energies using a pulsed-electron time-delayed-coincidence technique
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.
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.
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 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.
Directory of Open Access Journals (Sweden)
S. R. Freitas
2010-01-01
Full Text Available Vegetation fires emit hot gases and particles which are rapidly transported upward by the positive buoyancy generated by the combustion process. In general, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. In this paper, we revisit the parameterization of the vertical transport of hot gases and particles emitted from vegetation fires, described in Freitas et al. (2007, to include the effects of environmental wind on transport and dilution of the smoke plume at its scale. This process is quantitatively represented by introducing an additional entrainment term to account for organized inflow of a mass of cooler and drier ambient air into the plume and its drag by momentum transfer. An extended set of equations including the horizontal motion of the plume and the additional increase of the plume radius is solved to simulate the time evolution of the plume rise and the smoke injection height. One-dimensional (1-D model results are presented for two deforestation fires in the Amazon basin with sizes of 10 and 50 ha under calm and windy atmospheric environments. The results are compared to corresponding simulations generated by the complex non-hydrostatic three-dimensional (3-D Active Tracer High resolution Atmospheric Model (ATHAM. We show that the 1-D model results compare well with the full 3-D simulations. The 1-D model may thus be used in field situations where extensive computing facilities are not available, especially under conditions for which several optional cases must be studied.
Testing the Early Mars H2-CO2 Greenhouse Hypothesis with a 1-D Photochemical Model
Batalha, Natasha; Ramirez, Ramses; Kasting, James
2015-01-01
A recent study by Ramirez et al. (2014) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of water. Such warm temperatures appear necessary to generate the rainfall (or snowfall) amounts required to carve the ancient martian valleys. Here, we use our best estimates for early martian outgassing rates, along with a 1-D photochemical model, to assess the conversion efficiency of CO, CH4, and H2S to CO2, SO2, and H2. Our outgassing estimates assume that Mars was actively recycling volatiles between its crust and interior, as Earth does today. H2 production from serpentinization and deposition of banded iron-formations is also considered. Under these assumptions, maintaining an H2 concentration of ~1-2% by volume is achievable, but reaching 5% H2 requires additional H2 sources or a slowing of the hydrogen escape rate below the diffusion limit. If the early martian atmosphere...
Hyperbranched quasi-1D nanostructures for solid-state dye-sensitized solar cells.
Passoni, Luca; Ghods, Farbod; Docampo, Pablo; Abrusci, Agnese; Martí-Rujas, Javier; Ghidelli, Matteo; Divitini, Giorgio; Ducati, Caterina; Binda, Maddalena; Guarnera, Simone; Li Bassi, Andrea; Casari, Carlo Spartaco; Snaith, Henry J; Petrozza, Annamaria; Di Fonzo, Fabio
2013-11-26
In this work we demonstrate hyperbranched nanostructures, grown by pulsed laser deposition, composed of one-dimensional anatase single crystals assembled in arrays of high aspect ratio hierarchical mesostructures. The proposed growth mechanism relies on a two-step process: self-assembly from the gas phase of amorphous TiO2 clusters in a forest of tree-shaped hierarchical mesostructures with high aspect ratio; oriented crystallization of the branches upon thermal treatment. Structural and morphological characteristics can be optimized to achieve both high specific surface area for optimal dye uptake and broadband light scattering thanks to the microscopic feature size. Solid-state dye sensitized solar cells fabricated with arrays of hyperbranched TiO2 nanostructures on FTO-glass sensitized with D102 dye showed a significant 66% increase in efficiency with respect to a reference mesoporous photoanode and reached a maximum efficiency of 3.96% (among the highest reported for this system). This result was achieved mainly thanks to an increase in photogenerated current directly resulting from improved light harvesting efficiency of the hierarchical photoanode. The proposed photoanode overcomes typical limitations of 1D TiO2 nanostructures applied to ss-DSC and emerges as a promising foundation for next-generation high-efficiency solid-state devices comprosed of dyes, polymers, or quantum dots as sensitizers. PMID:24180577
KAM tori in 1D random discrete nonlinear Schrödinger model?
Johansson, M.; Kopidakis, G.; Aubry, S.
2010-09-01
We suggest that KAM theory could be extended for certain infinite-dimensional systems with purely discrete linear spectrum. We provide empirical arguments for the existence of square summable infinite-dimensional invariant tori in the random discrete nonlinear Schrödinger equation, appearing with a finite probability for a given initial condition with sufficiently small norm. Numerical support for the existence of a fat Cantor set of initial conditions generating almost periodic oscillations is obtained by analyzing i) sets of recurrent trajectories over successively larger time scales, and ii) finite-time Lyapunov exponents. The norm region where such KAM-like tori may exist shrinks to zero when the disorder strength goes to zero and the localization length diverges.
Influence of lipid rafts on CD1d presentation by dendritic cells
DEFF Research Database (Denmark)
Peng, Wei; Martaresche, Cecile
2011-01-01
Our main objective was to analyze the role of lipid rafts in the activation of Valpha-14(-) and Valpha-14(+) T hybridomas by dendritic cells. We showed that activation of Valpha-14(+) hybridomas by dendritic cells or other CD1d-expressing cells was altered by disruption of lipid rafts with the cholesterol chelator MbetaCD. However, CD1d presentation to autoreactive Valpha-14(-) anti-CD1d hybridomas which do not require the endocytic pathway was not altered. Using partitioning of membrane fractions with Brij98 at 37 degrees C, we confirmed that CD1d was enriched in subcellular fractions corresponding to lipid rafts and we describe that alpha-GalCer enhanced CD1d amount in the low density detergent insoluble fraction. We conclude that the membrane environment of CD1d can influence antigen presentation mainly when the endocytic pathway is required. Flow cytometry analysis can provide additional information on lipid rafts in plasma membranes and allows a dynamics follow-up of lipid rafts partitioning. Using this method, we showed that CD1d plasma membrane expression was sensitive to low concentrations of detergent. This may suggest either that CD1d is associated with lipid rafts mainly in intracellular membranes or that its association with the lipid rafts in the plasma membrane is weak.
Neodymium 1D systems: targeting new sources for field-induced slow magnetization relaxation.
Jassal, Amanpreet Kaur; Aliaga-Alcalde, Núria; Corbella, Montserrat; Aravena, Daniel; Ruiz, Eliseo; Hundal, Geeta
2015-09-01
Two non-isostructural homometallic 1D neodymium species displaying field-induced slow magnetization relaxations are presented together with theoretical studies. It is established that both systems are better described as organized 1D single molecule magnets (SMMs). Studies show great potential of Nd(III) ions to provide homometallic chains with slow magnetic relaxation. PMID:26299199
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.
Novel inhibitors targeting PPM1D phosphatase potently suppress cancer cell proliferation.
Ogasawara, Sari; Kiyota, Yuhei; Chuman, Yoshiro; Kowata, Ayano; Yoshimura, Fumihiko; Tanino, Keiji; Kamada, Rui; Sakaguchi, Kazuyasu
2015-10-01
Protein phosphatase magnesium-dependent 1? (PPM1D, Wip1) is a p53 inducible serine/threonine phosphatase. PPM1D is a promising target protein in cancer therapy since overexpression, missense mutations, truncating mutations, and gene amplification of PPM1D are reported in many tumors, including breast cancer and neuroblastoma. Herein, we report that a specific inhibitor, SL-176 that can be readily synthesized in 10 steps, significantly inhibits proliferation of a breast cancer cell line overexpressing PPM1D and induces G2/M arrest and apoptosis. SL-176 decreases PPM1D enzyme activity potently and specifically in vitro. These results demonstrate that SL-176 could be a useful lead compound in the development of effective anti-cancer agents. PMID:26358280
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.
1D compressible flow with temperature dependent transport coefficients
Jenssen, Helge Kristian
2009-01-01
We establish existence of global-in-time weak solutions to the one dimensional, compressible Navier-Stokes system for a viscous and heat conducting ideal polytropic gas (pressure $p=K\\theta/\\tau$, internal energy $e=c_v \\theta$), when the viscosity $\\mu$ is constant and the heat conductivity $\\kappa$ depends on the temperature $\\theta$ according to $\\kappa(\\theta) = \\bar \\kappa \\theta^\\beta$, with $0\\leq\\beta<{3/2}$. This choice of degenerate transport coefficients is motivated by the kinetic theory of gasses. Approximate solutions are generated by a semi-discrete finite element scheme. We first formulate sufficient conditions that guarantee convergence to a weak solution. The convergence proof relies on weak compactness and convexity, and it applies to the more general constitutive relations $\\mu(\\theta) = \\bar \\mu \\theta^\\alpha$, $\\kappa(\\theta) = \\bar \\kappa \\theta^\\beta$, with $\\alpha\\geq 0$, $0 \\leq \\beta < 2$ ($\\bar \\mu, \\bar \\kappa$ constants). We then verify the sufficient conditions in the case...
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)
DOE2.1D. Building Energy Consumption Analysis
Energy Technology Data Exchange (ETDEWEB)
Buhl, W.F. [Lawrence Berkeley National Lab., CA (United States)
1981-05-01
DOE2 is a set of programs for the analysis of energy consumption in buildings. Programs are included to calculate the heating and cooling loads for each space (zone) in the building for each hour of a year (LOADS), to simulate the operation and response of the equipment and systems that control temperature and humidity and distribute heating and cooling to the space (SYSTEMS), to model primary energy conversion equipment that uses fuel (e.g. oil, gas, or sun) to provide the required heating, cooling, and electricity (PLANT), and to compute the life-cycle cost for building operation based on economic parameters (ECONOMICS). A user-oriented building description language (BDL) facilitates the description of the building geometry, central plant equipment, HVAC systems, occupancy, equipment, and lighting schedules, and the selection of other problem parameters. In addition to the LSPE programs (LOADS, SYSTEMS, PLANT, and ECONOMICS), the system includes the BDL processor, two report generators, a weather data processor, and UPDATE, a code maintenance program. Standard output reports are produced by the RPTGEN program. Only the weather data for Chicago, which are required for execution of the sample problems, are included.
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
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.
Phosphine-free synthesis from 1D Pb(OH)Cl nanowires to 0D and 1D PbSe nanocrystals.
Shen, Huaibin; Li, Jinjie; Shang, Hangying; Niu, Jinzhong; Xu, Weiwei; Wang, Hongzhe; Guo, Fang; Li, Lin Song
2013-10-23
In this paper, we report a new phosphine-free, low-cost, low-temperature colloidal method of controlled synthesis of PbSe nanocrystals in both zero-dimension (0D) and one-dimension (1D). Different from the widely used "hot injection" method and "nonprecursor injection" method, the novelty of this new method is that it does not require a nucleation process. Instead, high-quality presynthesized 1D Pb(OH)Cl nanowires (?80 to ?160 nm in diameter) can be directly used as a Pb precursor and reacted with a Se precursor to form monodisperse dot-shaped 0D cubic PbSe and 1D orthorhombic PbSe nanowires. 0D cubic PbSe nanocrystals begin to form at elevated temperatures after the Se precursor is added to react with Pb(OH)Cl nanowires. By prolonging the reaction time for 3 h, good self-assembled 0D cubic PbSe nanocrystals can be synthesized with an average diameter of about 15 nm. Furthermore, such method has been demonstrated to synthsize high-quality 1D PbSe nanowires successfully with temperature as low as 110 °C. 1D PbSe nanowires possess a mean diameter of 15-24 nm with the shortest and longest length from 600 nm to 5 ?m. The only sharp and strong peak, which is consistent with characteristic peaks of orthorhombic PbSe, indicates that the nanowires' elongation axis is in the [111] direction, and 0D cubic PbSe nanocrystals change to 1D orthorhombic PbSe nanowires completely. PMID:24066872
POLARISATION OF THE S - PHASE OF SEISMOGRAMS
Directory of Open Access Journals (Sweden)
R. STONELEY
1951-06-01
Full Text Available In earthquakes recorded at moderate distances it lias been ohservedthat S phase appears first as SII, folloived some 10 to 14 seconds laterby SV. The object of tliis paper is to try to decide ichether doublérefraction is likely to be the explanation of tliis jìlwnomenon.A simpie model to consider ivould be a « transversely isotropie »material, symmetrical about the radiai direction. Formulae for thevelocities of SII and SV waves are available; tliese velocities dependon the angle that the ray makes ivi t li the norma!. It is unlikely thatthe Eartli could be as markedly anisotropie as the minerai beryl, whichis transversely isotropie; aceordingly, this material, of ivhich the fi veclastic constants are knoivn is taken as an extreme example, andthe velocities of SH and SV for different angles of incidence are« scaled down » so as to match the velocity of distortional ivaves ingranite. It is then possible to calcitiate the difference in the timo takenby ivaves from one point of the surface of the Earth to anotlier pointon the surface according as the S wave in the surface layer is of SHor SV type.
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 scores plot subpopulation cluster resolution.
Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids.
Sandusky, Peter; Appiah-Amponsah, Emmanuel; Raftery, Daniel
2011-04-01
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. PMID:21516384
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.
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.
Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R.; Mans, Dorus A.; Huber, Celine; Boldt, Karsten; Patel, Mitali; van Reeuwijk, Jeroen; Plaza, Jean-Marc; van Beersum, Sylvia E. C.; Yap, Zhi Min; Letteboer, Stef J. F.; Taylor, S. Paige; Herridge, Warren; Johnson, Colin A.; Scambler, Peter J.; Ueffing, Marius; Kayserili, Hulya; Krakow, Deborah; King, Stephen M.; Beales, Philip L.; Al-Gazali, Lihadh; Wicking, Carol; Cormier-Daire, Valerie; Roepman, Ronald; Mitchison, Hannah M.; Witman, George B.; Al-Turki, Saeed; Anderson, Carl; Anney, Richard; Antony, Dinu; Asimit, Jennifer; Ayub, Mohammad; Barrett, Jeff; Barroso, Inês; Bentham, Jamie; Bhattacharya, Shoumo; Blackwood, Douglas; Bobrow, Martin; Bochukova, Elena; Bolton, Patrick; Boustred, Chris; Breen, Gerome; Brion, Marie-Jo; Brown, Andrew; Calissano, Mattia; Carss, Keren; Chatterjee, Krishna; Chen, Lu; Cirak, Sebhattin; Clapham, Peter; Clement, Gail; Coates, Guy; Collier, David; Cosgrove, Catherine; Cox, Tony; Craddock, Nick; Crooks, Lucy; Curran, Sarah; Daly, Allan; Danecek, Petr; Smith, George Davey; Day-Williams, Aaron; Day, Ian; Durbin, Richard; Edkins, Sarah; Ellis, Peter; Evans, David; Farooqi, I. Sadaf; Fatemifar, Ghazaleh; Fitzpatrick, David; Flicek, Paul; Floyd, Jamie; Foley, A. Reghan; Franklin, Chris; Futema, Marta; Gallagher, Louise; Gaunt, Tom; Geschwind, Daniel; Greenwood, Celia; Grozeva, Detelina; Guo, Xiaosen; Gurling, Hugh; Hart, Deborah; Hendricks, Audrey; Holmans, Peter; Huang, Jie; Humphries, Steve E.; Hurles, Matt; Hysi, Pirro; Jackson, David; Jamshidi, Yalda; Jewell, David; Chris, Joyce; Kaye, Jane; Keane, Thomas; Kemp, John; Kennedy, Karen; Kent, Alastair; Kolb-Kokocinski, Anja; Lachance, Genevieve; Langford, Cordelia; Lee, Irene; Li, Rui; Li, Yingrui; Ryan, Liu; Lönnqvist, Jouko; Lopes, Margarida; MacArthur, Daniel G.; Massimo, Mangino; Marchini, Jonathan; Maslen, John; McCarthy, Shane; McGuffin, Peter; McIntosh, Andrew; McKechanie, Andrew; McQuillin, Andrew; Memari, Yasin; Metrustry, Sarah; Min, Josine; Moayyeri, Alireza; Morris, James; Muddyman, Dawn; Muntoni, Francesco; Northstone, Kate; O'Donovan, Michael; O'Rahilly, Stephen; Onoufriadis, Alexandros; Oualkacha, Karim; Owen, Michael; Palotie, Aarno; Panoutsopoulou, Kalliope; Parker, Victoria; Parr, Jeremy; Paternoster, Lavinia; Paunio, Tiina; Payne, Felicity; Perry, John; Pietilainen, Olli; Plagnol, Vincent; Quail, Michael A.; Quaye, Lydia; Raymond, Lucy; Rehnström, Karola; Brent Richards, J.; Ring, Sue; Ritchie, Graham R S; Savage, David B.; Schoenmakers, Nadia; Semple, Robert K.; Serra, Eva; Shihab, Hashem; Shin, So-Youn; Skuse, David; Small, Kerrin; Smee, Carol; Soler, Artigas María; Soranzo, Nicole; Southam, Lorraine; Spector, Tim; St Pourcain, Beate; St. Clair, David; Stalker, Jim; Surdulescu, Gabriela; Suvisaari, Jaana; Tachmazidou, Ioanna; Tian, Jing; Timpson, Nic; Tobin, Martin; Valdes, Ana; van Kogelenberg, Margriet; Vijayarangakannan, Parthiban; Wain, Louise; Walter, Klaudia; Wang, Jun; Ward, Kirsten; Wheeler, Ellie; Whittall, Ros; Williams, Hywel; Williamson, Kathy; Wilson, Scott G.; Wong, Kim; Whyte, Tamieka; ChangJiang, Xu; Zeggini, Eleftheria; Zhang, Feng; Zheng, Hou-Feng
2015-01-01
The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. We thus define TCTEX1D2 as an integral component of the evolutionarily conserved retrograde IFT machinery. In complex with several IFT dynein light chains, it is required for correct vertebrate skeletal formation but may be functionally redundant under certain conditions. PMID:26044572
GaAs solar cell photoresponse modeling using PC-1D V2.1
Huber, D. A.; Olsen, L. C.; Dunham, G.; Addis, F. W.
1991-01-01
Photoresponse data of high efficiency GaAs solar cells were analyzed using PC-1D V2.1. The approach required to use PC-1D for photoresponse data analysis, and the physical insights gained from performing the analysis are discussed. In particular, the effect of Al(x)Ga(1-x)As heteroface quality was modeled. Photoresponse or spectral quantum efficiency is an important tool in characterizing material quality and predicting cell performance. The strength of the photoresponse measurement lies in the ability to precisely fit the experimental data with a physical model. PC-1D provides a flexible platform for calculations based on these physical models.
Comet Halley O(1D) and H2O production rates
Magee-Sauer, K.; Scherb, F.; Roesler, F. L.; Harlander, J.
1990-01-01
Ground-based dual-etalon Fabry-Perot spectrometer observations have been made of Comet Halley's forbidden O I 6300 A emission. The 0.2 A resolution of the spectral scans was sufficient to resolve the O I forbidden line emissions from both nearby cometary NH2 and telluric emissions. On the basis of these measurements, the production rate Q of O(1D) was determined; it is then found, by taking into account the photodissociation of H2O and OH as sources of O(1D), that the ratio of H2O/O(1D) production rates is of the order of 6.
Decreased sensitivity of 5-HT(1D) receptors in melancholic depression.
Whale, R; Clifford, EM; Bhagwagar, Z; Cowen, PJ
2001-01-01
BACKGROUND: Brain serotonin (5-HT) function is abnormal in major depression, but the involvement of different 5-HT receptor subtypes has been little studied. The availability of selective ligands now makes it possible to test the sensitivity of 5-HT(1D) receptors in patients with depression. AIMS: The aim of the study was to use the 5-HT(1D) receptor agonist, zolmitriptan, to test the sensitivity of 5-HT(1D) receptors in patients with depression before and after treatment with selective serot...
[Dmt1, d-1-Nal3]morphiceptin, a novel opioid peptide analog with high analgesic activity.
Fichna, Jakub; do-Rego, Jean-Claude; Chung, Nga N; Costentin, Jean; Schiller, Peter W; Janecka, Anna
2008-04-01
The morphiceptin-derived peptide [Dmt1, d-1-Nal3]morphiceptin, labeled mu-opioid receptor (MOP) with very high affinity and selectivity in the receptor binding assays. In the mouse hot plate test, [Dmt1, d-1-Nal3]morphiceptin given intracerebroventricularly (i.c.v.) produced profound supraspinal analgesia, being approximately 100-fold more potent than the endogenous MOP receptor ligand, endomorphin-2. The antinociceptive effect of this new analog lasted up to 120min. Thus, [Dmt1, d-1-Nal3]morphiceptin is an interesting and extraordinarily potent analgesic, raising the possibility of novel approaches in the design of clinically useful drugs for pain treatment. PMID:18234394
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.)
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.
Gorelova, Natalia; Seamans, Jeremy K
2015-01-01
The persistent Na(+) current (I(Nap)) 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 I(Nap), the results have been contradictory largely because of difficulties in measuring I(Nap) 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 I(Nap), we demonstrate conclusively that D1/D5 receptor activation can increase the I(Nap) 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 I Nap is normally generated. PMID:25729354
1D Chemical Modeling of coupled snow-atmosphere chemistry at Dome C Antarctica
Gil, Jaime E.; Thomas, Jennie; von Glasgow, Roland; Bekki, Slimane; Kukui, Alexandre; Frey, Markus; Jourdain, Bruno; Kerbrat, Michel; Genthon, Christophe; Preuknert, Susanne; Legrand, Michel
2013-04-01
High levels of nitrogen oxides NOx (NOx=NO+NO2) generated by the photolysis of nitrate present in surface snow profoundly impact atmospheric composition and oxidizing capacity in the Antarctic boundary layer. In particular, NOx emissions from sunlit snow increase OH values by effectively recycling HO2 to OH. In order to better characterize this chemistry the OPALE campaign was conducted in December 2011/January 2012 at Dome C, Antarctica (altitude of 3,233 meters, 75 ° S, 123 ° E). The campaign included boundary layer profiling, measurements of the physical properties of snow, as well as a comprehensive suite of atmospheric chemistry measurements (including NOx, HONO, OH and RO2, H2O2, CH2O, O3). We present results using the 1-D coupled snow-boundary layer model MISTRA-SNOW in combination with observations made during the measurement campaign to understand this chemistry. The model includes both chemistry at the surface of snow grains (aqueous chemistry), in firn air (gas phase chemistry), and gas/aerosol chemistry in the boundary layer. Model predictions of NOx mixing ratios using a model sensitivity analysis approach are presented. The model was initialized using measured snow properties, including temperature, density, and snow grain size. In addition, the model dynamics are driven using the measured surface temperature at Dome C. To calculate the rate of snowpack ventilation, measured wind speeds during the campaign were used. The model was run varying the amount of nitrate and bromide available for reaction at the surface of snow grains and results are compared to measurements made in the atmospheric boundary from 2-4 January 2012. We test the hypothesis that very low concentrations of bromine may alter the ratio of NO/NO2. We also investigate the influence of NOx emissions from snow, and bromine (if present), on OH concentrations in the boundary layer on the Antarctic plateau.
Testing the early Mars H2-CO2 greenhouse hypothesis with a 1-D photochemical model
Batalha, Natasha; Domagal-Goldman, Shawn D.; Ramirez, Ramses; Kasting, James F.
2015-09-01
A recent study by Ramirez et al. (Ramirez, R.M. et al. [2014]. Nat. Geosci. 7(1), 59-63.) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of water. Such warm temperatures appear necessary to generate the rainfall (or snowfall) amounts required to carve the ancient martian valleys. Here, we use our best estimates for early martian outgassing rates, along with a 1-D photochemical model, to assess the conversion efficiency of CO, CH4, and H2S to CO2, SO2, and H2. Our outgassing estimates assume that Mars was actively recycling volatiles between its crust and interior, as Earth does today. H2 production from serpentinization and deposition of banded iron-formations is also considered. Under these assumptions, maintaining an H2 concentration of ˜1-2% by volume is achievable, but reaching 5% H2 requires additional H2 sources or a slowing of the hydrogen escape rate below the diffusion limit. If the early martian atmosphere was indeed H2-rich, we might be able to see evidence of this in the rock record. The hypothesis proposed here is consistent with new data from the Curiosity Rover, which show evidence for a long-lived lake in Gale Crater near Mt. Sharp. It is also consistent with measured oxygen fugacities of martian meteorites, which show evidence for progressive mantle oxidation over time.
The relation of scan range and reflection shape in single-crystal 1D profile measurement
International Nuclear Information System (INIS)
Changes in shape of 1D profiles of small-single-crystal Bragg reflections have been examined in terms of the shapes of the components which, convoluted together, generate the profile. In most practical cases, operational features require truncation of the angular scan range of measurement and the conventional linear formula for scan range, ?=a+bxtan ?, is then not strictly valid. A more appropriate relationship involves a combination of root mean square (RMS) and linear (LIN) forms, ?=[(p')2+(q'xtan ?2]1/2 + (p''+q''xtan ?) where p' is associated with the leading and trailing edges of the distribution of the combined ?-invariant components and p'' with its plateau width while q' is associated with the leading and trailing edges of the distribution of the wavelength component and q'' with the separation of its outer peaks if there are more than one. For operational purposes, this relationship can be substituted with adequate precision by ?=[c2+(dxtan ?)2]1/2, but the parameters c and d do not then have a simple relationship to the ?-invariant and ?-variant components. Use of a conventional linear formula when a RMS one is the relevant one can mean that, in the lower ? range, the estimate of integrated intensity will be too high and, in the higher ? range, it will be too low, so that, with increasing ?, a positive then a negative systematic error is introduced and not merely a negative error not merely a negative error as the conventional interpretation of truncation holds. The conclusions of the present analysis are tested against experimental data where the conventional treatment for truncation failed. For the estimation of integrated intensity, and hence of structure factors, which are consistent over the operational range of ?, a RMS formula for the scan range is advisable. (orig.)
Complex Zeros of Eigenfunctions of 1D Schr\\"odinger Operators
Hezari, Hamid
2007-01-01
In this article we study the semi-classical distribution of complex zeros of the eigenfunctions of the 1D Schr\\"odinger operators for the class of polynomial potentials of even degree, when an energy level E is fixed.
Non-uniform black strings and the critical dimension in the $1/D$ expansion
Suzuki, Ryotaku
2015-01-01
Non-uniform black strings (NUBS) are studied by the large $D$ effective theory approach. By solving the near-horizon geometry in the $1/D$ expansion, we obtain the effective equation for the deformed horizon up to the next-to-next-to-leading order (NNLO) in $1/D$. We also solve the far-zone geometry by the Newtonian approximation. Matching the near and far zones, the thermodynamic variables are computed in the $1/D$ expansion. As the result, the large $D$ analysis gives a critical dimension $D_*\\simeq13.5$ at which the translation-symmetry-breaking phase transition changes between first and second order. This value of $D_*$ agrees perfectly, within the precision of the $1/D$ expansion, with the result previously obtained by E. Sorkin through the numerical resolution. We also compare our NNLO results for the thermodynamics of NUBS to earlier numerical calculations, and find good agreement within the expected precision.
Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R.; Mans, Dorus A.; Huber, Celine; Boldt, Karsten; Patel, Mitali; Reeuwijk, Jeroen van; Plaza, Jean-Marc; van Beersum, Sylvia E. C.; Yap, Zhi Min; Letteboer, Stef J. F.; Taylor, S. Paige; Herridge, Warren; Johnson, Colin A.
2015-01-01
The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. W...
Quantum Cable as transport spectroscopy of 1D DOS of cylindrical quantum wires
Z. Y. Zeng; Xiang, Y; L. D. Zhang
2001-01-01
We considered the proposed Quantum Cable as a kind of transport spectroscopy of one-dimensional (1D) density of states (DOS) of cylindrical quantum wires. By simultaneously detecting the direct current through the cylindrical quantum wire and the leaked tunneling current into the neighboring wire at desired temperatures, one can obtain detailed information about 1D DOS and subband structure of cylindrical quantum wires.
Standard 1D solar atmosphere as initial condition for MHD simulations and switch-on effects
Bourdin, Philippe-A.
2015-01-01
Many applications in Solar physics need a 1D atmospheric model as initial condition or as reference for inversions of observational data. The VAL atmospheric models are based on observations and are widely used since decades. Complementary to that, the FAL models implement radiative hydrodynamics and showed the shortcomings of the VAL models since almost equally long time. In this work, we present a new 1D layered atmosphere that spans not only from the photosphere to the tr...
Decreased sensitivity of 5-HT1D receptors in chronic tension-type headache
BENEDETTI, Fabrizio; PINESSI, Lorenzo; VALFRE', Walter; ISAIA, Giovanni Carlo; POLLO, Antonella; LIMONE, Paolo Piero; Rainero, Innocenzo
2002-01-01
OBJECTIVE: To assess the sensitivity of 5-HT1D receptors in chronic tension-type headache using sumatriptan as a pharmacological probe. BACKGROUND: Previous studies have suggested involvement of serotonergic systems in chronic tension-type headache (CTTH), but relevant experimental data are limited. Sumatriptan, a 5-HT1B/1D receptor agonist, stimulates the release of growth hormone (GH) and inhibits the release of ACTH, cortisol, and prolactin. These effects may be used to explore the functio...
Zolmitriptan-induced growth hormone release in humans: mediation by 5-HT1D receptors?
Whale, R; Bhagwagar, Z; Cowen, PJ
1999-01-01
RATIONALE: Effective neuroendocrine probes of 5-HT1B and 5-HT1D receptor function may facilitate investigation of the role of these receptor subtypes in the pathophysiology of depression and the mode of action of antidepressant medication. OBJECTIVE: To investigate the neuroendocrine profile of the 5-HT1B/1D receptor agonist, zolmitriptan, in healthy volunteers. METHODS: Twelve subjects entered a double-blind, placebo-controlled, cross-over design study of zolmitriptan (5 mg orally). Blood sa...
Probing the function of 5-HT(1B/1D) receptors in psychiatric patients
Whale, R; Cowen, PJ
1998-01-01
Pharmacological challenge tests provide a method of assessing the functional responsiveness of serotonin (5-HT) receptor subtypes in the human brain. A number of selective agonist ligands for the 5-HT(1B/1D) receptor are available for human use; however, these compounds do not distinguish between 5-HT(1B) and 5-HT(1D) receptors, which is somewhat of a disadvantage. Acute administration of sumatriptan, rizatriptan, and zolmitriptan all increase plasma growth hormone in healthy subjects, possib...
1D model for the dynamics and expansion of elongated Bose-Einstein condensates
Massignan, Pietro; Modugno, Michele
2002-01-01
We present a 1D effective model for the evolution of a cigar-shaped Bose-Einstein condensate in time dependent potentials whose radial component is harmonic. We apply this model to investigate the dynamics and expansion of condensates in 1D optical lattices, by comparing our predictions with recent experimental data and theoretical results. We also discuss negative-mass effects which could be probed during the expansion of a condensate moving in an optical lattice.
Transparent Conducting Electrodes based on 1D and 2D Ag Nanogratings for Organic Photovoltaics
Zeng, Beibei; Kafafi, Zakya H.; Bartoli, Filbert J.
2014-01-01
The optical and electrical properties of optically-thin one-dimensional (1D) Ag nanogratings and two-dimensional (2D) Ag nanogrids are studied, and their use as transparent electrodes in organic photovoltaics are explored. A large broadband and polarization-insensitive optical absorption enhancement in the organic light-harvesting layers is theoretically and numerically demonstrated using either single-layer 2D Ag nanogrids or two perpendicular 1D Ag nanogratings, and is att...
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)
International Nuclear Information System (INIS)
Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO2-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO2-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO2-nanoproducts with different morphologies through a simple process and from a low cost precursor.
Evaluation of genetic susceptibility of common variants in CACNA1D with schizophrenia in Han Chinese
Guan, Fanglin; Li, Lu; Qiao, Chuchu; Chen, Gang; Yan, Tinglin; Li, Tao; Zhang, Tianxiao; Liu, Xinshe
2015-01-01
The heritability of schizophrenia (SCZ) has been estimated to be as high as 80%, suggesting that genetic factors may play an important role in the etiology of SCZ. Cav1.2 encoded by CACNA1C and Cav1.3 encoded by CACNA1D are dominant calcium channel-forming subunits of L-type Voltage-dependent Ca2+ channels, expressed in many types of neurons. The CACNA1C has been consistently found to be a risk gene for SCZ, but it is unknown for CACNA1D. To investigate the association of CACNA1D with SCZ, we designed a two-stage case-control study, including a testing set with 1117 cases and 1815 controls and a validation set with 1430 cases and 4295 controls in Han Chinese. A total of selected 97 tag single nucleotide polymorphisms (SNPs) in CACNA1D were genotyped, and single-SNP association, imputation analysis and gender-specific association analyses were performed in the two independent datasets. None was found to associate with SCZ. Further genotype and haplotype association analyses indicated a similar pattern in the two-stage study. Our findings suggested CACNA1D might not be a risk gene for SCZ in Han Chinese population, which add to the current state of knowledge regarding the susceptibility of CACNA1D to SCZ. PMID:26255836
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.
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
Wang, Shengjie; Cai, Qingwei; Du, Mingxuan; Xue, Junyi; Xu, Hai
2015-09-10
Artificial synthesis of silica under benign conditions is usually achieved by using cationic organic matrices as templates while the anionic analogues have not received enough consideration, albeit they are also functioning in biosilica formation. In this work, we report the design and self-assembly of an anionic peptide amphiphile (I3E) and the use of its self-assemblies as templates to synthesize 1D silica nanostructures with tunable sizes. We show that short I3E readily formed long nanofibrils in aqueous solution via a hierarchical self-assembly process. By using APTES and TEOS as silica precursors, we found that the I3E nanofibrils templated the production of silica nanotubes with a wide size distribution, in which the silica size regulation was achieved by tuning the interactions among the peptide template and silicon species. These results clearly illustrate a facile method for generating silica nanomaterials based on anionic matrices. PMID:26301578
Deconvolution of Complex 1D NMR Spectra Using Objective Model Selection
Hughes, Travis S.; Wilson, Henry D.; de Vera, Ian Mitchelle S.; Kojetin, Douglas J.
2015-01-01
Fluorine (19F) NMR has emerged as a useful tool for characterization of slow dynamics in 19F-labeled proteins. One-dimensional (1D) 19F NMR spectra of proteins can be broad, irregular and complex, due to exchange of probe nuclei between distinct electrostatic environments; and therefore cannot be deconvoluted and analyzed in an objective way using currently available software. We have developed a Python-based deconvolution program, decon1d, which uses Bayesian information criteria (BIC) to objectively determine which model (number of peaks) would most likely produce the experimentally obtained data. The method also allows for fitting of intermediate exchange spectra, which is not supported by current software in the absence of a specific kinetic model. In current methods, determination of the deconvolution model best supported by the data is done manually through comparison of residual error values, which can be time consuming and requires model selection by the user. In contrast, the BIC method used by decond1d provides a quantitative method for model comparison that penalizes for model complexity helping to prevent over-fitting of the data and allows identification of the most parsimonious model. The decon1d program is freely available as a downloadable Python script at the project website (https://github.com/hughests/decon1d/). PMID:26241959
CD1d-restricted antigen presentation by V?9V?2-T cells requires trogocytosis.
Schneiders, Famke L; Prodöhl, Jan; Ruben, Jurjen M; O'Toole, Tom; Scheper, Rik J; Bonneville, Marc; Scotet, Emmanuel; Verheul, Henk M W; de Gruijl, Tanja D; van der Vliet, Hans J
2014-08-01
CD1d-restricted invariant natural killer T cells (iNKT) constitute an important immunoregulatory T-cell subset that can be activated by the synthetic glycolipid ?-galactosylceramide (?-GalCer) and play a dominant role in antitumor immunity. Clinical trials with ?-GalCer-pulsed monocyte-derived dendritic cells (moDC) have shown anecdotal antitumor activity in advanced cancer. It was reported that phosphoantigen (pAg)-activated V?9V?2-T cells can acquire characteristics of professional antigen-presenting cells (APC). Considering the clinical immunotherapeutic applications, V?9V?2-T APC can offer important advantages over moDC, potentially constituting an attractive novel APC platform. Here, we demonstrate that V?9V?2-T APC can present antigens to iNKT. However, this does not result from de novo synthesis of CD1d by V?9V?2-T, but critically depends on trogocytosis of CD1d-containing membrane fragments from pAg-expressing cells. CD1d-expressing V?9V?2-T cells were able to activate iNKT in a CD1d-restricted and ?-GalCer-dependent fashion. Although ?-GalCer-loaded moDC outperformed V?9V?2-T APC on a per cell basis, V?9V?2-T APC possess unique features with respect to clinical immunotherapeutic application that make them an interesting platform for consideration in future clinical trials. PMID:24934445
Designing Heterogeneous 1D Nanostructure Arrays Based on AAO Templates for Energy Applications.
Wen, Liaoyong; Wang, Zhijie; Mi, Yan; Xu, Rui; Yu, Shu-Hong; Lei, Yong
2015-07-01
In order to fulfill the multiple requirements for energy production, storage, and utilization in the future, the conventional planar configuration of current energy conversion/storage devices has to be reformed, since technological evolution has promoted the efficiency of the corresponding devices to be close to the theoretical values. One promising strategy is to construct multifunctional 1D nanostructure arrays to replace their planar counterparts for device fabrication, ascribing to the significant superiorities of such 1D nanostructure arrays. In the last three decades, technologies based on anodic aluminium oxide (AAO) templates have turned out to be valuable meaning for the realization of 1D nanostructures and have attracted tremendous interest. In this review, recent progress in energy-related devices equipped with heterogeneous 1D nanostructure arrays that fabricated through the assistance of AAO templates is highlighted. Particular emphasis is given on how to develop efficient devices via optimizing the componential and morphological parameters of the 1D nanostructure arrays. Finally, aspects relevant to the further improvement of device performance are discussed. PMID:25914151
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.
Microstates of D1-D5(-P) black holes, as interacting D-branes
Morita, Takeshi; Shiba, Shotaro
2015-07-01
In our previous study (Morita et al., 2014 [1]), 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.
Microstates of D1–D5(-P black holes, as interacting D-branes
Directory of Open Access Journals (Sweden)
Takeshi Morita
2015-07-01
Full Text Available In our previous study (Morita et al., 2014 [1], 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.
Transparent Conducting Electrodes based on 1D and 2D Ag Nanogratings for Organic Photovoltaics
Zeng, Beibei; Bartoli, Filbert J
2014-01-01
The optical and electrical properties of optically-thin one-dimensional (1D) Ag nanogratings and two-dimensional (2D) Ag nanogrids are studied, and their use as transparent electrodes in organic photovoltaics are explored. A large broadband and polarization-insensitive optical absorption enhancement in the organic light-harvesting layers is theoretically and numerically demonstrated using either single-layer 2D Ag nanogrids or two perpendicular 1D Ag nanogratings, and is attributed to the excitation of surface plasmon resonances and plasmonic cavity modes. Total photon absorption enhancements of 150% and 200% are achieved for the optimized single-layer 2D Ag nanogrids and double (top and bottom) perpendicular 1D Ag nanogratings, respectively.
Standard 1D solar atmosphere as initial condition for MHD simulations and switch-on effects
Bourdin, Philippe-A
2015-01-01
Many applications in Solar physics need a 1D atmospheric model as initial condition or as reference for inversions of observational data. The VAL atmospheric models are based on observations and are widely used since decades. Complementary to that, the FAL models implement radiative hydrodynamics and showed the shortcomings of the VAL models since almost equally long time. In this work, we present a new 1D layered atmosphere that spans not only from the photosphere to the transition region, but from the solar interior up to far in the corona. We also discuss typical mistakes that are done when switching on simulations based on such an initial condition and show how the initial condition can be equilibrated so that a simulation can start smoothly. The 1D atmosphere we present here served well as initial condition for HD and MHD simulations and should also be considered as reference data for solving inverse problems.
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.
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 ...
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.
Thermodynamics of Large N Gauge Theories with Chemical Potentials in a 1/D Expansion
Morita, Takeshi
2010-01-01
In order to understand thermodynamical properties of N D-branes with chemical potentials associated with R-symmetry charges, we study a one dimensional large N gauge theory (bosonic BFSS type model) as a first step. This model is obtained through a dimensional reduction of a 1+D dimensional SU(N) Yang-Mills theory and we use a 1/D expansion to investigate the phase structure. We find three phases in the \\mu-T plane. We also show that all the adjoint scalars condense at large...
Review of fringe pattern phase recovery using the 1-D and 2-D continuous wavelet transforms
Watkins, Lionel R.
2012-08-01
The mathematical theory underlying the one- and two-dimensional continuous wavelet transforms (CWT) is briefly reviewed. The phase or instantaneous frequency of fringe patterns with spatial or temporal carriers can be recovered from the wavelet ridge, a path that follows the maximum modulus of the CWT. The relative merits of these two approaches, termed the phase and gradient methods, respectively, are discussed. Common 1-D wavelets are listed and their broad scope of applicability is indicated. Popular 2-D isotropic and directional wavelets are given and the advantages of 2-D wavelet methods over 1-D are discussed.
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.
Magnetic Excitations in the Quasi-1D Ising-like Antiferromagnet TlCoCl$_3$
Oosawa, A; Kato, T; Kakurai, K
2005-01-01
Neutron inelastic scattering measurements have been performed in order to investigate the magnetic excitations in the quasi-1D Ising-like antiferromagnet TlCoCl$_3$. We observed the magnetic excitation, which corresponds to the spin-wave excitation continuum corresponding to the domain-wall pair excitation in the 1D Ising-like antiferromagnet. According to the Ishimura-Shiba theory, we analyzed the observed spin-wave excitation, and the exchange constant $2J$ and the anistropy $\\epsilon$ were estimated as 14.7 meV and 0.14 in TlCoCl$_3$, respectively.
Comet Austin (1989c1) O(1D) and H2O production rates
Schultz, D.; Li, G. S. H.; Scherb, F.; Roesler, F. L.
1992-01-01
The dual-etalon Fabry-Perot spectrometer of Kitt Peak's McMath solar telescope has been used to conduct Comet Austin observations with spectral scan resolutions of 0.21 A; this sufficed for resolution of cometary forbidden O I 6300 A emissions from nearby NH2, as well as telluric emissions of the same type. For these data, an O(1D) production rate is obtained which is noted to be nearly model-independent. The H2O production rate is determined by taking into account the photodissociation of H2O and OH as sources of O(1D).
Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays
Kuo, Shou-Yi; Lin, Hsin-I
2014-01-01
Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol–gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimenta...
Excitation content of spectral functions in the 1D t-J model
International Nuclear Information System (INIS)
The excitation content of spectral functions of the 1D t-J model with nearest neighbor (n.n.) interactions is obtained from the Bethe-Ansatz solution at the supersymmetric point and compared with quantum Monte Carlo (QMC) simulations based on the hybrid-loop algorithm. We consider the one-particle spectrum as well as the dynamical spin and charge structure factors. The connection to the 1D supersymmetric t-J model with 1/r2 interaction will be explained
Superdescendants of the D1D5 CFT and their dual 3-charge geometries
Giusto, StefanoDipartimento di Fisica ed Astronomia “Galileo Galilei”, Università di Padova, Via Marzolo 8, 35131, Padova, Italy; Russo, Rodolfo
2014-01-01
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...
Epitaxial 1D electron transport layers for high-performance perovskite solar cells
Han, Gill Sang; Chung, Hyun Suk; Kim, Dong Hoe; Kim, Byeong Jo; Lee, Jin-Wook; Park, Nam-Gyu; Cho, In Sun; Lee, Jung-Kun; Lee, Sangwook; Jung, Hyun Suk
2015-09-01
We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport.We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport. Electronic supplementary information (ESI) available: Histograms of the parameters, UV-vis absorption spectrum and the cross-sectional FE-SEM image of the TiO2 NP based mp-ETL cell, TiO2/SnO2 NWs based 1D-ETL perovskite solar cells and exposure FTO at grown SnO2 NWs on FTO substrate. See DOI: 10.1039/c5nr03476k
Directory of Open Access Journals (Sweden)
Kowit Boonrawd
2015-04-01
Full Text Available A coupling of a 1-D flood routing model and quasi 2-D floodplain inundation model is applied for mapping spacetime flood extent. The routing model is formulated based on a non-linear storage-discharge relationship which is converted from an observed and synthetic rating curve. To draw the rating curve, required parameters for each reaches are estimated from hydraulic properties, floodplain geometry and vegetation and building cover of compound channels. The shape of the floodplain is defined by using fitting exercise based on the reverse approach between past and simulated inundation flood extent, to solve the current problem of inadequate topographic input data for floodplain. Mapping of daily flood can be generated relying on flat water levels. The quasi 2-D raster model is tested and applied to generate more realistic water surface and is used to estimate flood extent. The model is applied to the floodplains of Chiang Mai, north of Thailand and used to estimate a time series of hourly flood maps. Extending from daily to hourly flood extent, mapping development provides more details of flood inundation extent and depth.
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.
Scientific Electronic Library Online (English)
W., Wang; H., Zhu; H., Zhang; L., Zhang; Q., Ding; H., Jiang.
2014-12-01
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.
Minimal representations of supersymmetry and 1D N-extended ?-models
International Nuclear Information System (INIS)
We discuss 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. Their knowledge allows to construct one-dimensional sigma-models with extended off-shell supersymmetries without using superfields (author)
Well-posedness of 1-D compressible Euler-Poisson equations with physical vacuum
Gu, Xumin
2011-01-01
This paper is concerned with the 1-D compressible Euler-Poisson equations with moving physical vacuum boundary condition. It is usually used to describe the motion of a self-gravitating inviscid gaseous star. The local well-posedness of classical solutions is established in the case of the adiabatic index $1<\\gamma<3$.
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)
Formation of 1D adsorbed water structures on CaO(001)
Zhao, Xunhua; Bhattacharya, Saswata; Ghiringhelli, Luca M.; Levchenko, Sergey V.; Scheffler, Matthias
2015-03-01
Understanding the interaction of water with oxide surfaces is of fundamental importance for basic and engineering sciences. Recently, a spontaneous formation of one-dimensional (1D) adsorbed water structures have been observed on CaO(001). Interestingly, at other alkaline earth metal oxides, in particular MgO(001) and SrO(001), such structures have not been found experimentally. We calculate the relative stability of adsorbed water structures on the three oxides using density-functional theory combined with the ab initio atomistic thermodynamics. Low-energy structures at different coverages are obtained with a first-principles genetic algorithm. Finite-temperature vibrational spectra are calculated using ab initio molecular dynamics. We find a range of (T, p) conditions where 1D structures are thermodynamically stable on CaO(001). The orientation and vibrational spectra of the 1D structures are in agreement with the experiments. The formation of the 1D structures is found to be actuated by a symmetry breaking in the adsorbed water tetramer, as well as by a balance between water-water and water-substrate interactions, determined by the lattice constant of the oxide.
1-D and 2D-NMR assignments of nigricin from Iris imbricata
Directory of Open Access Journals (Sweden)
Seyed Abdul Majid Ayatollahi
2005-01-01
Full Text Available Ethanolic crude extract of I. imbricata Lindl. (Iridaceae was subjected to column chromatography on silica gel with varying portions of MeOH: CHCl3. Nigicin (irisolone was isolated and its identification carried out by IR, UV, MS, 1-D and 2-D NMR spectroscopy
1-D and 2D-NMR assignments of nigricin from Iris imbricata
Seyed Abdul Majid Ayatollahi; Mahmood Reza Moein; Farzad Kobarfard; Shama Nasim; Muhammad Iqbal Choudhary
2005-01-01
Ethanolic crude extract of I. imbricata Lindl. (Iridaceae) was subjected to column chromatography on silica gel with varying portions of MeOH: CHCl3. Nigicin (irisolone) was isolated and its identification carried out by IR, UV, MS, 1-D and 2-D NMR spectroscopy
Solvent-free porous framework resulted from 3D entanglement of 1D zigzag coordination polymer
Kole, Goutam Kumar Umar
2010-01-01
A solvent-free porous metal organic framework is constructed by the 3D entanglement of 1D zigzag coordination polymeric chains. The role of solvents and the effect of reaction conditions on such unique entanglement are addressed. © 2010 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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)
Models of Late-Type Disk Galaxies: 1-D Versus 2-D
Mineikis, Tadas
2015-01-01
We investigate the effects of stochasticity on the observed galaxy parameters by comparing our stochastic star formation two-dimensional (2-D) galaxy evolution models with the commonly used one-dimensional (1-D) models with smooth star formation. The 2-D stochastic models predict high variability of the star formation rate and the surface photometric parameters across the galactic disks and in time.
Glucose sensor using periodic nanostructured hybrid 1D Au/ZnO arrays
International Nuclear Information System (INIS)
Hybrid 1D nanostructured Au/ZnO arrays were created by heat treatment of a spin-coated zinc acetate-PVA-Au(III) layer on surface relief grating and functioned as an electrochemical and optical D(+)-glucose sensor due to electrochemical oxidation between hybrid nanostructures and D(+)-glucose. The morphology and chemical composition of 1D Au/ZnO hybrid arrays were characterized by means of AFM, SEM, EDAX, and XPS. Electrochemical and optical sensitivities by the addition of D(+)-glucoses on 1D Au/ZnO arrays were investigated using Cyclic voltammetry and UV–vis-NIR spectra in the medical concentration ranges of 0.5, 2.0, and 8.0 mM. - Highlights: ? Zinc acetate-PVA-Au(III) composites were prepared by simply mixing zinc acetate-PVA and gold(III) chloride trihydrate. ? Hybrid 1D nanostructured Au/ZnO arrays were easily fabricated using surface relief gratings without additional process steps. ? Redox and optical sensor to detect D(+)-glucoses.
Dilepton production in high energy heavy ion collisions with 3+1D relativistic viscous hydrodynamics
International Nuclear Information System (INIS)
We present a first calculation of the dilepton yield and elliptic flow done with 3+1D viscous hydrodynamical simulations of relativistic heavy ion collisions at the top RHIC energy. A comparison with recent experimental data from the STAR collaboration is made
MODELLING TRANSIENT VARIABLY SATURATED FLOW UNDER NATURAL CONDITIONS USING HYDRUS-1D
The Hydrus-1D software package (Simunek et al., 1998), based on the Richards equation, was used to study variably saturated flow and deep drainage in an old abandoned terraced area under grass. The field site was located in the Vallcebre research catchment of the Eastern Pyrenees in North-Eastern Sp...
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.
Phase structure of (2+1)d strongly coupled lattice gauge theories
Strouthos, C G
2003-01-01
We study the chiral phase transition in (2+1)d strongly coupled U(N) lattice gauge theories with staggered fermions. We show with high precision simulations performed directly in the chiral limit that these models undergo a Berezinski-Kosterlitz-Thouless (BKT) transition. We also show that this universality class is unaffected even in the large N limit.
Electron localization in 1D conductors due to the phonon scattering
Gogolin, A. A.
1983-09-01
Electron localization in 1D conductors due to scattering by dispersionless optical phonons at low temperatures has been studied by applying the Berezinsky diagram technique. The large localization length lloc, much longer than the mean free path l, has been found. The low frequency optical absorption is described by the law: Re ?( ?) ˜ ?2 |ln 3?|.
A new EEG measure using the 1D cluster variation method
Maren, Alianna J.; Szu, Harold H.
2015-05-01
A new information measure, drawing on the 1-D Cluster Variation Method (CVM), describes local pattern distributions (nearest-neighbor and next-nearest neighbor) in a binary 1-D vector in terms of a single interaction enthalpy parameter h for the specific case where the fractions of elements in each of two states are the same (x1=x2=0.5). An example application of this method would be for EEG interpretation in Brain-Computer Interfaces (BCIs), especially in the frontier of invariant biometrics based on distinctive and invariant individual responses to stimuli containing an image of a person with whom there is a strong affiliative response (e.g., to a person's grandmother). This measure is obtained by mapping EEG observed configuration variables (z1, z2, z3 for next-nearest neighbor triplets) to h using the analytic function giving h in terms of these variables at equilibrium. This mapping results in a small phase space region of resulting h values, which characterizes local pattern distributions in the source data. The 1-D vector with equal fractions of units in each of the two states can be obtained using the method for transforming natural images into a binarized equi-probability ensemble (Saremi & Sejnowski, 2014; Stephens et al., 2013). An intrinsically 2-D data configuration can be mapped to 1-D using the 1-D Peano-Hilbert space-filling curve, which has demonstrated a 20 dB lower baseline using the method compared with other approaches (cf. SPIE ICA etc. by Hsu & Szu, 2014). This CVM-based method has multiple potential applications; one near-term one is optimizing classification of the EEG signals from a COTS 1-D BCI baseball hat. This can result in a convenient 3-D lab-tethered EEG, configured in a 1-D CVM equiprobable binary vector, and potentially useful for Smartphone wireless display. Longer-range applications include interpreting neural assembly activations via high-density implanted soft, cellular-scale electrodes.
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.
TBC1D5 and the AP2 complex regulate ATG9 trafficking and initiation of autophagy.
Popovic, Doris; Dikic, Ivan
2014-04-01
The RabGAP protein TBC1D5 controls cellular endomembrane trafficking processes and binds the retromer subunit VPS29 and the ubiquitin-like protein ATG8 (LC3). Here, we describe that TBC1D5 also associates with ATG9 and the active ULK1 complex during autophagy. Moreover, ATG9 and TBC1D5 interact with clathrin and the AP2 complex. Depletion of TBC1D5 leads to missorting of ATG9 to late endosomes upon activation of autophagy, whereas inhibition of clathrin-mediated endocytosis or AP2 depletion alters ATG9 trafficking and its association with TBC1D5. Taken together, our data show that TBC1D5 and the AP2 complex are important novel regulators of the rerouting of ATG9-containing vesicular carriers toward sites of autophagosome formation. PMID:24603492
Andersson, P.; Valldor-Blücher, J.; Andersson Sundén, E.; Sjöstrand, H.; Jacobsson-Svärd, S.
2014-08-01
The FANTOM system is a tabletop sized fast-neutron radiography and tomography system newly developed at the Applied Nuclear Physics Division of Uppsala University. The main purpose of the system is to provide time-averaged steam-and-water distribution measurement capability inside the metallic structures of two-phase test loops for light water reactor thermal-hydraulic studies using a portable fusion neutron generator. The FANTOM system provides a set of 1D neutron transmission data, which may be inserted into tomographic reconstruction algorithms to achieve a 2D mapping of the steam-and-water distribution. In this paper, the selected design of FANTOM is described and motivated. The detector concept is based on plastic scintillator elements, separated for spatial resolution. Analysis of pulse heights on an event-to-event basis is used for energy discrimination. Although the concept allows for close stacking of a large number of detector elements, this demonstrator is equipped with only three elements in the detector and one additional element for monitoring the yield from the neutron generator. The first measured projections on test objects of known configurations are presented. These were collected using a Sodern Genie 16 neutron generator with an isotropic yield of about 1E8 neutrons per second, and allowed for characterization of the instrument's capabilities. At an energy threshold of 10 MeV, the detector offered a count rate of about 500 cps per detector element. The performance in terms of spatial resolution was validated by fitting a Gaussian Line Spread Function to the experimental data, a procedure that revealed a spatial unsharpness in good agreement with the predicted FWHM of 0.5 mm.
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
TBC1D5 and the AP2 complex regulate ATG9 trafficking and initiation of autophagy
Popovic, D.; Dikic, I
2014-01-01
The RabGAP protein TBC1D5 controls cellular endomembrane trafficking processes and binds the retromer subunit VPS29 and the ubiquitin-like protein ATG8 (LC3). Here, we describe that TBC1D5 also associates with ATG9 and the active ULK1 complex during autophagy. Moreover, ATG9 and TBC1D5 interact with clathrin and the AP2 complex. Depletion of TBC1D5 leads to missorting of ATG9 to late endosomes upon activation of autophagy, whereas inhibition of clathrin-mediated endocytosis or AP2 depletion a...
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.
International Nuclear Information System (INIS)
Copper iodide one-dimensional nanocrystals within single walled carbon nanotubes (1D CuI@SWCNTs), i.e. meta-nanotubes [1], were investigated by high resolution electron microscopy (HRTEM). In meta-nanotubes of diameter Dm = 1.3-1.4 nm produced by arc-discharge (AD) method close-packed hexagonal or deformed cubic 1D crystal anion sublattices were observed with cations in octahedral or tetrahedral positions. These two sublattices reversibly transform to one another. In catalysed chemical vapour deposition (CCVD) meta-nanotubes of diameters Dm = 1.5-2.0 nm cubic anion sublattices are formed. For diameters ?2.0 nm three-dimensional (3D) crystallization is observed
Hyperfine structures of the nd 1D(n = 3 - 8) states of 3He I
International Nuclear Information System (INIS)
We have used the beam-foil quantum beat method to measure the hyperfine structure separations F = 3/2 - 5/2 of the 1snd 1D states (n = 3 - 8) of 3He I. We observed the single frequency modulated decay curves of the 1s2p 1P - 1snd 1D transitions for times after excitation up to 50 ns, corresponding to 4 to 5 modulation periods. The frequencies obtained (with a precision of 2 to 5%) are compared with other experiments and theory. The frequencies are determined mainly by the singlet-triplet energy separations and mixing factors for the He I D-states. The results agree with the same parameters obtained from other recent level-crossing measurements in strong magnetic field mixing of the singlet-triplet states
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.
Quantization of coupled 1D vector modes in integrated photonic waveguides
International Nuclear Information System (INIS)
A quantum mechanical analysis of the guided light in integrated photonics waveguides is presented. The analysis is made starting from one-dimensional (1D) guided vector modes by taking into account the modal orthonormalization property on a cross section of an optical waveguide, the vector structure of the guided optical modes and the reversal-time symmetry in order to quantize the 1D vector modes and to derive the quantum momentum operator and the Heisenberg equations. The results provide a quantum-consistent formulation of the linear and nonlinear quantum light propagations as a function of forward and backward creation and annihilation operators in integrated photonics. As an illustration, an application to an integrated nonlinear directional coupler is given, that is, both the nonlinear momentum and the Heisenberg equations of the nonlinear coupler are derived
A 1D model for the description of mixing-controlled reacting diesel sprays
Energy Technology Data Exchange (ETDEWEB)
Desantesa, J.M.; Pastor, J.V.; Garcia-Oliver, J.M.; Pastor, J.M. [CMT - Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022, Valencia (Spain)
2009-01-15
The paper reports an investigation on the transient evolution of diesel flames in terms of fuel-air mixing, spray penetration and combustion rate. A one-dimensional (1D) spray model, which was previously validated for inert diesel sprays, is extended to reacting conditions. The main assumptions of the model are the mixing-controlled hypothesis and the validity of self-similarity for conservative properties. Validation is achieved by comparing model predictions with both CFD gas jet simulations and experimental diesel spray measurements. The 1D model provides valuable insight into the evolution of the flow within the spray (momentum and mass fluxes, tip penetration, etc.) when shifting from inert to reacting conditions. Results show that the transient diesel flame evolution is mainly governed by two combustion-induced effects, namely the reduction in local density and the increase in flame radial width. (author)
Collective mode damping and viscosity in a 1D unitary Fermi gas
Punk, M
2006-01-01
We calculate the damping of the Bogoliubov-Anderson mode in a one-dimensional two-component attractive Fermi gas for arbitrary coupling strength within a quantum hydrodynamic approach. Using the Bethe-Ansatz solution of the 1D BCS-BEC crossover problem, we derive analytic results for the viscosity covering the full range from a Luther-Emery liquid of weakly bound pairs to a Lieb-Liniger gas of strongly bound bosonic dimers. At the unitarity point, the system is a Tonks-Girardeau gas with a universal constant $\\alpha_{\\zeta}=0.38$ in the viscosity $\\zeta=\\alpha_{\\zeta}\\hbar n$ for T=0. For the trapped case, we calculate the Q-factor of the breathing mode and show that the damping provides a sensitive measure of temperature in 1D Fermi gases.
All the supersymmetric solutions of N = 1, d = 5 ungauged supergravity
International Nuclear Information System (INIS)
We classify the supersymmetric solutions of ungauged N = 1 d = 5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstroem black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N = 2, d = 4 solutions. Our formulae allows the uplifting of certain N = 2, d = 4 black holes to N = 1, d = 5 black holes on KK monopoles or to pp-waves propagating along black strings
All the supersymmetric solutions of N=1,d=5 ungauged supergravity
Bellorin, J; Ortín, T
2007-01-01
We classify the supersymmetric solutions of ungauged N=1 d=5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstrom black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N=2,d=4 solutions. Our formulae allows the uplifting of certain N=2,d=4 black holes to N=1,d=5 black holes on KK monopoles or to pp-waves propagating along black strings.
Slice imaging of nitric acid photodissociation: The O(1D) + HONO channel
International Nuclear Information System (INIS)
We report an imaging study of nitric acid (HNO3) photodissociation near 204 nm with detection of O(1D), one of the major decomposition products in this region. The images show structure reflecting the vibrational distribution of the HONO coproduct and significant angular anisotropy that varies with recoil speed. The images also show substantial alignment of the O(1D) orbital, which is analyzed using an approximate treatment that reveals that the polarization is dominated by incoherent, high order contributions. The results offer additional insight into the dynamics of the dissociation of nitric acid through the S3 (2 1A') excited state, resolving an inconsistency in previously reported angular distributions, and pointing the way to future studies of the angular momentum polarization.
A finite element solver and energy stable coupling for 3D and 1D fluid models
Dobroserdova, Tatiana K
2013-01-01
The paper develops a solver based on conforming finite element method (FEM) for a 3D--1D coupled incompressible flow problem. New coupling conditions are introduced to ensure a suitable bound for the cumulative energy of the model. We study the stability and the accuracy of the discretization method and the performance of some state-of-the-art linear algebraic solvers for such flow configurations. Motivated by the simulation of the flow over inferior vena cava (IVC) filter, we consider the coupling of a 1D fluid model and a 3D fluid model posed in a domain with anisotropic inclusions. The relevance of our approach to realistic cardiovascular simulations is demonstrated by computing a blood flow over a model IVC filter.
Adiabatic evolution of 1D shape resonances: an artificial interface conditions approach.
Faraj, Ali; Mantile, Andrea; Nier, Francis
2011-01-01
Artificial interface conditions parametrized by a complex number $\\theta_{0}$ are introduced for 1D-Schr\\"odinger operators. When this complex parameter equals the parameter $\\theta\\in i\\R$ of the complex deformation which unveils the shape resonances, the Hamiltonian becomes dissipative. This makes possible an adiabatic theory for the time evolution of resonant states for arbitrarily large time scales. The effect of the artificial interface conditions on the important stati...
On variational data assimilation for 1D and 2D fluvial hydraulics
Gejadze, Igor; Honnorat, Marc; Le Dimet, François-Xavier; Monnier, Jerome
2006-01-01
We address two problems related to variational data assimilation (VDA) as applied to river hydraulics (1D and 2D shallow water models). First, we seek to estimate accurately some parameters such as the inflow discharge, manning coefficients, the topography and/or the initial state. We develop a method which allow to assimilate lagrangian data (trajectory particles at the surface e.g. extracted from video images). Second, we develop a joint data assimilation - coupling method. We seek to coupl...
Evidence for BCS diquark condensation in the 3+1d lattice NJL model
International Nuclear Information System (INIS)
We present results of numerical simulations of the 3+1d Nambu-Jona-Lasinio model with a non-zero baryon chemical potential ?, with particular emphasis on the superfluid diquark condensate and associated susceptibilities. The results, when extrapolated to the zero diquark source limit, are consistent with the existence of a non-zero BCS condensate at high baryon density. The nature of the infinite volume and zero temperature limits are discussed
Synthesis, Characterization, and Application of 1-D Cerium Oxide Nanomaterials: A Review
Kuen-Song Lin; Sujan Chowdhury
2010-01-01
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 constructivel...
Lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns
Dong, Pinliang
2009-10-01
Spatial scale plays an important role in many fields. As a scale-dependent measure for spatial heterogeneity, lacunarity describes the distribution of gaps within a set at multiple scales. In Earth science, environmental science, and ecology, lacunarity has been increasingly used for multiscale modeling of spatial patterns. This paper presents the development and implementation of a geographic information system (GIS) software extension for lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns. Depending on the application requirement, lacunarity analysis can be performed in two modes: global mode or local mode. The extension works for: (1) binary (1-bit) and grey-scale datasets in any raster format supported by ArcGIS and (2) 1D, 2D, and 3D point datasets as shapefiles or geodatabase feature classes. For more effective measurement of lacunarity for different patterns or processes in raster datasets, the extension allows users to define an area of interest (AOI) in four different ways, including using a polygon in an existing feature layer. Additionally, directionality can be taken into account when grey-scale datasets are used for local lacunarity analysis. The methodology and graphical user interface (GUI) are described. The application of the extension is demonstrated using both simulated and real datasets, including Brodatz texture images, a Spaceborne Imaging Radar (SIR-C) image, simulated 1D points on a drainage network, and 3D random and clustered point patterns. The options of lacunarity analysis and the effects of polyline arrangement on lacunarity of 1D points are also discussed. Results from sample data suggest that the lacunarity analysis extension can be used for efficient modeling of spatial patterns at multiple scales.
1D numerical approach to model the flow over a piano key weir (PKW)
Erpicum, Sébastien; Machiels, Olivier; Archambeau, Pierre; Dewals, Benjamin(*); Pirotton, Michel
2010-01-01
Piano Key Weir (PKW) is a new type of weir showing appealing hydraulic capacities, in particular for low heads. However, its complex geometry, with a large set of parameters, makes difficult the understanding of the flow features and consequently the definition of an optimal design. In this paper, we investigate how a 1D numerical approach can predict the flow over a PKW and thus help in identifying the most relevant geometric parameters. After a detailed description of the numerical model, a...
Neutron scattering study of magnetic Fe1+d Te thin films grown under tensile stress
Demirdi?, S.; Su, Y.; Nemkowski, K.; Wang, R.; Huang, Z. X.; Cao, L. X.
2015-10-01
Polarized neutron scattering reveals the presence of magnetic order in Fe1+dTe/MgO (0.04 ? d ? 0.1) grown under tensile stress. Neutron diffraction data shows the magnetic ordering with propagation vector (-0.5 0 -0.5) and the transition temperature is found TN ? 67 K from the temperature dependent measurement. In addition possible understanding of the strain effect on the lattice parameters of FeTe is discussed based on the present neutron data.
Random phase approximation for the 1D anti-ferromagnetic Heisenberg model
International Nuclear Information System (INIS)
The Hartree-Fock random phase approximation (HF-RPA) approach is applied to the one-dimensional (1D) anti-ferromagnetic Heisenberg model in the Jordan-Wigner representation. Somewhat contrary to expectation, this leads to reasonable results for spectral functions and sum rules in the symmetry-unbroken phase. In a preliminary application of self-consistent RPA to finite-size chains, strongly improved results are obtained
Quantum Integrable 1D anyonic Models: Construction through Braided Yang-Baxter Equation
Directory of Open Access Journals (Sweden)
Anjan Kundu
2010-10-01
Full Text Available Applying braided Yang-Baxter equation quantum integrable and Bethe ansatz solvable 1D anyonic lattice and field models are constructed. Along with known models we discover novel lattice anyonic and q-anyonic models as well as nonlinear Schrödinger equation (NLS and the derivative NLS quantum field models involving anyonic operators, N-particle sectors of which yield the well known anyon gases, interacting through ? and derivative ?-function potentials.
Raman scattering on DWCNT filled with 1D CdSe nanowire
Directory of Open Access Journals (Sweden)
E. Belandria
2007-01-01
Full Text Available Se estudio el espectro Raman no polarizado a temperatura ambiente de los modos radiales y tangenciales de nanotubos de carbono de doble pared rellenos del semiconductor CdSe nanocristalino 1D, excitado con 514.5 nm. En la region de bajo numero de onda observamos varios ´ fonones que corresponden a los modos radiales de los tubos internos y externos, los fonones opticos confinados LO y TO y fonones ´ opticos ´ superficiales del nanoalambre de CdSe.
Folding a 2-D powder diffraction image into a 1-D scan: a new procedure
Cervellino, Antonio; Giannini, Cinzia; Guagliardi, Antonietta; Ladisa, Massimo
2006-01-01
A new procedure aiming at folding a powder diffraction 2-D into a 1-D scan is presented. The technique consists of three steps: tracking the beam centre by means of a Simulated Annealing (SA) of the diffraction rings along the same axis, detector tilt and rotation determination by a Hankel Lanczos Singular Value Decomposition (HLSVD) and intensity integration by an adaptive binning algorithm. The X-ray powder diffraction (XRPD) intensity profile of the standard NIST Si 640c ...
Soliton phase near antiferromagnetic quantum critical point in Q1D conductors
Gor'Kov, L.P.; Grigoriev, P.D.
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...
Holographic description of non-supersymmetric orbifolded D1-D5-P solutions
Chakrabarty, Bidisha; Turton, David; Virmani, Amitabh(Institute of Physics, Sachivalaya Marg, Bhubaneswar, Odisha, 751005, India)
2015-01-01
Non-supersymmetric black hole microstates are of great interest in the context of the black hole information paradox. We identify the holographic description of the general class of non-supersymmetric orbifolded D1-D5-P supergravity solutions found by Jejjala, Madden, Ross and Titchener. This class includes both completely smooth solutions and solutions with conical defects, and in the near-decoupling limit these solutions describe degrees of freedom in the cap region. The C...
Nakamura, Takashi; Kuroi, Moeka; Harashima, Hideyoshi
2015-08-01
Alpha-galactosylceramide (GC), a lipid antigen present on CD1d molecules, is a unique adjuvant that enables a strong antitumor effect to be induced via activation of natural killer T cells. We previously reported that a liposomal formulation of GC significantly enhanced GC presentation via CD1d and antitumor immunity. However, the influence of the intracellular fate of liposomes controlled by the lipid composition on GC presentation using GC-loaded liposomes (GC-Lip) remains unclear. In this study, we prepared a GC-Lip formulation by incorporating dioleoyl-phosphatidylethanolamine (DOPE)/cholesterol, egg phosphatidylcholine (EPC)/cholesterol, and distearoyl phosphocholine (DSPC)/cholesterol, and investigated the relationship between the intracellular trafficking of GC-Lip and GC presentation in antigen-presenting cells. When GC-Lip was prepared using DOPE, a fusogenic lipid, the endosomal escape of liposomes was enhanced, resulting in a decrease in GC presentation of CD1d, compared to the EPC based GC-Lip (EPC/GC-Lip). The stability of liposomes in endosomes/lysosomes had no influence on GC presentation. The DSPC based GC-Lip (DSPC/GC-Lip) induced GC presentation without any detectable degradation in liposomal structure, although the EPC/GC-Lip induced GC presentation with degradation of liposomal structure. The efficiency of GC presentation between EPC/GC-Lip and DSPC/GC-Lip was comparable. These GC presentations that were independent of the degradation of liposomes were dominated by saposins, sphingolipid activator proteins. Our findings reveal that GC presentation on CD1d from the fluid liposomes involves the action of saposins, regardless of whether liposome degradation occurs. This insight can be of use in terms of developing GC-Lip formulation for efficient GC presentation. PMID:26107189
Li-diffusion and lattice relaxation in the 1-d superionic-conductor beta-eucryptite
International Nuclear Information System (INIS)
The 1-d Li+ conductor ?-eucryptite (LiAlSiO4) was studied by quasi-elastic neutron measurements. From the coherent scattering it can be shown that correlations between the Li+ ions are extremely important up to the highest investigated temperatures (T0C). The diffusion of individual ions was studied by incoherent scattering. For the Li+ a jump diffusion along c with mainly a jump-distance of c/3 was confirmed. (Auth.)
Characterization of all the supersymmetric solutions of gauged N = 1, D 5 supergravity
International Nuclear Information System (INIS)
We find a complete characterization of all the supersymmetric solutions of non-Abelian gauged N = 1, d = 5 supergravity coupled to vector multiplets and hypermultiplets: the generic forms of the metrics as functions of the scalars and vector fields plus the equations that all these must satisfy. These equations are now a complicated non-linear system and there it seems impossible to produce an algorithm to construct systematically all supersymmetric solutions
Characterization of all the supersymmetric solutions of gauged N=1,d=5 supergravity
Bellorin, Jorge
2007-01-01
We find a complete characterization of all the supersymmetric solutions of non-Abelian gauged N=1,d=5 supergravity coupled to vector multiplets and hypermultiplets: the generic forms of the metrics as functions of the scalars and vector fields plus the equations that all these must satisfy. These equations are now a complicated non-linear system and there it seems impossible to produce an algorithm to construct systematically all supersymmetric solutions.
Characterization of all the supersymmetric solutions of gauged N=1,d=5 supergravity
Bellorín Romero, Jorge Alejandro; Ortín Miguel, Tomás
2007-01-01
We find a complete characterization of all the supersymmetric solutions of non-Abelian gauged N = 1, d = 5 supergravity coupled to vector multiplets and hypermultiplets: the generic forms of the metrics as functions of the scalars and vector fields plus the equations that all these must satisfy. These equations are now a complicated non-linear system and there it seems impossible to produce an algorithm to construct systematically all supersymmetric solutions.
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
Insulin stimulation regulates AS160 and TBC1D1 phosphorylation sites in human skeletal muscle
DEFF Research Database (Denmark)
Middelbeek, R J W; Chambers, M A
2013-01-01
Individuals with obesity and type 2 diabetes (T2D) are typically insulin resistant, exhibiting impaired skeletal muscle glucose uptake. Animal and cell culture experiments have shown that site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 and TBC1D1 is critical for GLUT4 translocation facilitating glucose uptake, but their regulation in human skeletal muscle is not well understood.
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.
Inverse problem for the discrete 1D Schr\\"odinger operator with small periodic potentials
Korotyaev, Evgeny; Kutsenko, Anton
2005-01-01
Consider the discrete 1D Schr\\"odinger operator on $\\Z$ with an odd $2k$ periodic potential $q$. For small potentials we show that the mapping: $q\\to $ heights of vertical slits on the quasi-momentum domain (similar to the Marchenko-Ostrovski maping for the Hill operator) is a local isomorphism and the isospectral set consists of $2^k$ distinct potentials. Finally, the asymptotics of the spectrum are determined as $q\\to 0$.
International Nuclear Information System (INIS)
Wh study phase coherent transport in a single channel system using the scattering matrix approach. It is show that the Friedel sum rule and the time-reversal symmetry result in the generic appearance of transmission zeros in quasi-1d systems. The transmission zeros naturally lead to abrupt phase changes (without any intrinsic energy scale) and in-phase resonances, thus providing insights to recent experiments on phase coherent transport through a quantum dot
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.
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...
International Nuclear Information System (INIS)
Is described, of very general way, the principal cycles and technologies for the thermoelectric generation. It is made special reference to power cycles that employ steam as work fluid, to those of internal combustion, as well as to the combined (heat and power, steam and power) and the principal alternatives of cogeneration. As a means of general illustration comparative tables of thermoelectric generation costs for different thermal generation plans are presented
Karim Bagha
2011-01-01
Generative semantics is (or perhaps was) a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of the program are a matter of some controversy and have been extensively debated. Generative semanticists took Chomsky's concept of deep structure an...
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.
Characterisation of J(O1D) at Cape Grim 2000-2005
Wilson, S. R.
2015-07-01
Estimates of the rate of production of excited oxygen atoms due to the photolysis of ozone (J(O1D)) have been derived from radiation measurements carried out at Cape Grim, Tasmania (40.6° S, 144.7° E). The individual measurements have a total uncertainty of 16 % (1?). These estimates agree well with model estimates of clear-sky photolysis rates. Observations spanning 2000-2005 have been used to quantify the impact of season, clouds and ozone column amount. The annual cycle of J(O1D) has been investigated via monthly means. These means show an interannual variation (monthly standard deviation) of 9 %, but in midsummer and midwinter this reduces to 3-5 %. Variations in solar zenith angle and total column ozone explain 86 % of the observed variability in the measured photolysis rates. The impact of total column ozone, expressed as a radiation amplification factor (RAF), is found to be ~ 1.53, in agreement with model estimates. This ozone dependence explains 20 % of the variation observed at medium solar zenith angles (30-50°). The impact of clouds results in a median reduction of 30 % in J(O1D) for the same solar zenith angle range. Including estimates of cloudiness derived from long-wave radiation measurements resulted in a statistically significant fit to observations, but the quality of the fit did not increase significantly as measured by the adjusted R2.
Neutronic analysis of the 1D and 1E banks reflux detection system
Energy Technology Data Exchange (ETDEWEB)
Blanchard, A.
1999-12-21
Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely, the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal {sup 235}U concentration levels to reflux levels remain satisfactory detectable.
Effects of sex and age on chicken TBC1D1 gene mRNA expression.
Peng, Y D; Xu, H Y; Ye, F; Lan, X; Peng, X; Rustempaši?, A; Yin, H D; Zhao, X L; Liu, Y P; Zhu, Q; Wang, Y
2015-01-01
The objective of this study was to investigate the effects of sex and slaughter age of chickens on fatty acid composition and TBC1D1 gene expression in 4 different tissues: breast muscle, thigh muscle, abdominal fat, and subcutaneous fat. Sixty Erlang mountainous chickens (hybrid SD02 x SD03) were raised under the same conditions and slaughtered at 8, 10, and 13 weeks of age. The results showed that the sex of the animal significantly affected the content of arachidic acid (C20:0), sinapic (C22:1), linoleic (C18:2n-6), eicosapentaenoic (C20:5n-3), and docosahexaenoic acids (C22:6n-3), whereas other fatty acid contents were not affected. Age had a significant effect on most monounsaturated fatty acids, except for octadecenoic acid (C18:1). TBC1D1 mRNA was abundant in all tissues at all 3 ages of slaughter. Cocks exhibited higher TBC1D1 mRNA levels than hens in the thigh muscle and abdominal fat at 10 and 13 weeks, respectively. PMID:26214451
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.
Effects of randomness on the critical temperature in quasi-1D and quasi-2D superconductors
Energy Technology Data Exchange (ETDEWEB)
Nakhmedov, Enver [Institut fuer Theoretische Physik, Universitaet Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany); Institute of Physics, Azerbaijan National Academy of Sciences, H. Cavid str. 33, AZ1143 Baku (Azerbaijan); Alekperov, Oktay [Institute of Physics, Azerbaijan National Academy of Sciences, H. Cavid str. 33, AZ1143 Baku (Azerbaijan); Oppermann, Reinhold [Institut fuer Theoretische Physik, Universitaet Wuerzburg, Am Hubland, D-97074 Wuerzburg (Germany)
2013-07-01
Effects of non-magnetic disorder on the critical temperature T{sub c} and on diamagnetism of quasi-1D and quasi-2D superconductors (SCs) are reported. The organic SCs are modeled as superconducting wires or layers connecting each others through the Josephson coupling. The Josephson energy is considered to be random parameter with Gaussian distribution. The phase of the order parameter is averaged over thermodynamic fluctuations as well as over disorder by employing the replica method. We show that the randomness destroys phase coherence between wires in quasi-1D SCs and that T{sub c} vanishes discontinuously at a critical disorder-strength. Nevertheless the disorder of arbitrary high strength in quasi-2D organic SCs can not destroy completely the superconducting phase. The interplay between disorder and quantum phase fluctuations is shown to result in quantum critical behavior at T=0 in quasi-1D SCs, which manifests itself as a superconducting-normal metal phase transition of first-order at a critical disorder strength. The parallel and transverse components of the penetration-depth are evaluated. They diverge at different critical temperatures, which correspond to pair-breaking and phase-coherence breaking respectively. Our theory agrees well with the experimental measurements.
Supersymmetric Configurations In The Rotating D1-d5 System Andpp-waves
Maoz, L
2003-01-01
Two families of supersymmetric configurations are considered. One is the 1/4 supersymmetric D1–D5 system with angular momentum, and the other is a family of pp-waves of type IIB string theory with some supersymmetry. In the first part of the thesis some configurations of the D1–D5 system are examined which give conical singularities in AdS 3 as their near horizon limit. It is shown that they can be made non-singular by adding angular momentum to the brane system. The smooth asymptotically flat solutions constructed this way are used to obtain global AdS 3 as the near horizon geometry. Using the relation of the D1–D5 system to the oscillating string, a large family of supergravity solutions is constructed which describe BPS excitations on AdS3 × S 3 with angular momentum on S3. These solutions take into account the full back reaction on the metric, and can be viewed as Kaluza-Klein monopole “supertubes”, which are completely non- singular geometries. ...
Energy Technology Data Exchange (ETDEWEB)
Ness, E.
1999-09-02
Distributed generation, locating electricity generators close to the point of consumption, provides some unique benefits to power companies and customers that are not available from centralized electricity generation. Photovoltaic (PV) technology is well suited to distributed applications and can, especially in concert with other distributed resources, provide a very close match to the customer demand for electricity, at a significantly lower cost than the alternatives. In addition to augmenting power from central-station generating plants, incorporating PV systems enables electric utilities to optimize the utilization of existing transmission and distribution.
Development of a supersonic O(3P/sub J/), O(1D2) atomic oxygen nozzle beam source
International Nuclear Information System (INIS)
A high pressure, radio frequency discharge nozzle beam source has been developed for the production of very intense (> or =1018 atoms sr-1 s-1) supersonic beams of oxygen atoms. An efficient impedance matching scheme has been devised for coupling the radio frequency power to oxygen--rare gas mixtures as a function of gas pressure, temperature, and composition. Techniques for localizing the discharge directly behind the orifice of a specially designed quartz nozzle have also been developed. The above combine to yield a beam source which reliably produces a high degree of molecular dissociation in oxygen--rare gas mixtures at pressures up to 350 Torr. Atomic oxygen mean translational energies from 0.14--0.50 eV have been achieved using the seeded beams technique with Mach numbers up to 10 being realized. When helium is used as the carrier gas both O(3P/sub J/) and O(1D2) atoms are present in the beam, while only ground state atoms appear to be present in argon seeded mixtures. This paper describes the design, construction, and operation of this beam source and provides a characterization of the atomic oxygen beams it has reproducibly generated in our laboratory
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)
A 2D/1D coupling neutron transport method based on the matrix MOC and NEM methods
Energy Technology Data Exchange (ETDEWEB)
Zhang, H.; Zheng, Y.; Wu, H.; Cao, L. [School of Nuclear Science and Technology, Xi' an Jiaotong University, No. 28, Xianning West Road, Xi' an, Shaanxi 710049 (China)
2013-07-01
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)
Karabash, Illya M
2011-01-01
The paper is devoted to optimization of quasi-normal eigenvalues of a spectral problem associated with a 1-D wave equation in an inhomogeneous medium. The wave equation is equipped with a radiation boundary condition, and so the set of quasi-normal eigenvalues lies in $\\C_+$. The problem is to design for a given $\\alpha \\in \\R$ the structure of the inhomogeneous medium such that it generates a quasi-normal eigenvalue on the line $\\alpha + \\i \\R$ with a minimal possible imaginary part. We consider the problem for three admissible families of structures. Two of these families have a natural mechanical interpretation as classes of Krein strings with total mass and static moment constraints. For these two classes we find optimal quasi-normal eigenvalues explicitly. The third class of admissible structures is connected with the problem of optimal design for photonic crystals. For this class, the paper gives a wider statement of the optimization problem, proves existence of optimal structures, and study their prope...
Generation Of Flood Inundation Model – General Approach And Methodology
Marina Mazlan,; Mohd Adib Mohammed Razi
2014-01-01
This paper presents in general the approach, methodology and applied practice for the generation of flood inundation model. The generation of the model cover on: (1) data availability, (2) methodology, (3) flood modeling using the one-dimensional (1D) and two-dimensional (2D) hydrodynamic model, and (4) generation of flood inundation modelof integration of hydrodynamic model and flood mapping approach. The Sembrong River hydrodynamic model, Sembrong River flood mapping, and Ko...
MAST-1D, a Model to Route Sediment and Tracers in Channel-Floodplain Complexes
Viparelli, E.; Lauer, J. W.; Belmont, P.
2014-12-01
Sediment exchange between the channel and floodplain can occur via meander migration, overbank deposition or erosion, and channel widening or narrowing. Depending on channel and floodplain history, floodplains can act either as sources or sinks of bed material and/or wash load. The Morphodynamics And Sediment Tracers in 1D program (MAST-1D) is a numerical model built to describe grain size specific transport of sediment and tracers and the long-term - i.e. decadal and longer - evolution of channel floodplain complexes. MAST-1D differs from other 1D numerical models because it allows for 1) uneven exchange of sediment and tracers between the river channel and the floodplain, 2) temporal changes in channel geometry, bed elevation and floodplain thickness, which result in changes in the channel hydraulic capacity, and 3) temporal changes of size distribution and tracer content in the floodplain, in the load and in the underlying substrate. Under conditions of constant base level, water and sediment supply, the main assumptions in the model result in the system evolving asymptotically toward a steady state wherein channel bed erosion is balanced by channel bed deposition. When at this condition, the amount of sediment deposited on the floodplain through point bar deposition and overbank sedimentation is balanced by the erosion of sediment from the floodplain through lateral migration. However, imbalances in floodplain storage can persist for many years even when the channel bed elevation and size distribution are near steady state. The MAST-1D program is applied to study the long term response of a sand bed river, an 80 km long reach of the Minnesota River between Mankato and Jordan, Minnesota, to changes in flow regime and the sediment load due to the development of intensive agriculture in the watershed. The simulations are performed in successive phases, the model is first set up so that under the best estimates available for pre-agriculture conditions, channel floodplain exchange is even. Changes in flow regime, sediment load, and grain size of sediment load are then applied to represent agricultural development of the basin. The model is first validated against field data. It is then applied to investigate how the channel-floodplain response changes for different grain size distributions of the sediment load.
Position error in profiles retrieved from MIPAS observations with a 1-D algorithm
Directory of Open Access Journals (Sweden)
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.
Quantum electrodynamics with 1D arti cial atoms : from Purcell enhancement to single-photon
DEFF Research Database (Denmark)
Javadi, Alisa
2015-01-01
A 1D atom, a single quantum emitter coupled to a single optical mode, exhibits rich quantum electrodynamic (QED) e_ects and is thought to be the key ingredient for many applications in quantuminformation processing. Single quantum dots (QD) in photonic-crystal waveguides (PCW) constitute a robust platform for realizing a 1D atom, and are the subject of theoretical and experimental investigations in this thesis. We use _nite element method in 3D to calculate the local density of states (LDOS) in photonic-crystal membranes. The detailed spatial maps show strong inhibition of LDOS in the bandgap of the PhC, as large as 160 times. The method is extended to PCWs using a set of active boundary conditions. The extended method allows separating the contribution to the LDOS from the propagating mode and the radiation continuum. The detailed spatial maps of the LDOS show that for a broad spectral range, the contribution from the radiation continuum is much less than the contribution from the guided mode. The coupling e_ciency between an embedded emitter and the PCW is shown to be higher than 90% for a wide range of dipole positions, frequencies and orientaitions, which quali_es the system as a candidate for a 1D atom. One of the signatures and functions of a 1D atom is the nonlinear optical response at the single-photon level. A PCW chip is designed to experimentally study the transmission spectrum of an embedded QD. The transmission spectrum is shown to be modi_ed by 30% around the resonance of the QD. The power dependence of the transmission shows a nonlinearity with a critical power of 1:9 nW, which corresponds to an average number of 0.8 photons per lifetime of the emitter at the position of the QD. The autocorrelation function of the transmitted _eld shows bunching of the transmitted photons as expected from the theory. The value of g(2)(0) is around 1.08. The results con_rm the observation of an on-chip giant optical nonlinearity and the 1D atom behavior. Another direction in this thesis has been to investigate the e_ect of Anderson localization on the electrodynamics of QDs in PCWs. A large data set of the statistics of Purcell-enhancement of QDs in Anderson-localized cavities is presented. The average Purcell-enhancement of 4.5 times, with a peak value of 12 is observed for QDs randomly positioned in Anderson-localized modes of a PCW.
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 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.
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)
Galactose-modified iNKT cell agonists stabilized by an induced fit of CD1d prevent tumour metastasis
Aspeslagh, Sandrine; Li, Yali; Yu, Esther Dawen; Pauwels, Nora; Trappeniers, Matthias; Girardi, Enrico; Decruy, Tine; Van Beneden, Katrien; Venken, Koen; Drennan, Michael; Leybaert, Luc; Wang, Jing; Franck, Richard W.; Van Calenbergh, Serge; Zajonc, Dirk M.
2011-01-01
Invariant natural killer T (iNKT) cells are activated by lipid derivatives presented by the non-classical MHC I molecule CD1d. Galactose-modified glycolipids enhance the affinity of glycolipids for CD1d, leading to sustained iNKT cell responses and tumour protection in vivo.
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.
Coupled 1D-3D hydrodynamic modelling, with application to the Pearl River Delta
Twigt, Daniel J.; de Goede, Erik D.; Zijl, Firmijn; Schwanenberg, Dirk; Chiu, Alex Y. W.
2009-12-01
Within the hydrodynamic modelling community, it is common practice to apply different modelling systems for coastal waters and river systems. Whereas for coastal waters 3D finite difference or finite element grids are commonly used, river systems are generally modelled using 1D networks. Each of these systems is tailored towards specific applications. Three-dimensional coastal water models are designed to model the horizontal and vertical variability in coastal waters and are less well suited for representing the complex geometry and cross-sectional areas of river networks. On the other hand, 1D river network models are designed to accurately represent complex river network geometries and complex structures like weirs, barrages and dams. A disadvantage, however, is that they are unable to resolve complex spatial flow variability. In real life, however, coastal oceans and rivers interact. In deltaic estuaries, both tidal intrusion of seawater into the upstream river network and river discharge into open waters play a role. This is frequently approached by modelling the systems independently, with off-line coupling of the lateral boundary forcing. This implies that the river and the coastal model run sequentially, providing lateral discharge (1D) and water level (3D) forcing to each other without the possibility of direct feedback or interaction between these processes. An additional disadvantage is that due to the time aggregation usually applied to exchanged quantities, mass conservation is difficult to ensure. In this paper, we propose an approach that couples a 3D hydrodynamic modelling system for coastal waters (Delft3D) with a 1D modelling system for river hydraulics (SOBEK) online. This implies that contrary to off-line coupling, the hydrodynamic quantities are exchanged between the 1D and 3D domains during runtime to resolve the real-time exchange and interaction between the coastal waters and river network. This allows for accurate and mass conserving modelling of complex coastal waters and river network systems, whilst the advantages of both systems are maintained and used in an optimal and computationally efficient way. The coupled 1D-3D system is used to model the flows in the Pearl River Delta (Guangdong, China), which are determined by the interaction of the upstream network of the Pearl River and the open waters of the South China Sea. The highly complex upstream river network is modelled in 1D, simulating river discharges for the dry and wet monsoon periods. The 3D coastal model simulates the flow due to the external (ocean) periodic tidal forcing, the salinity distribution for both dry and wet seasons, as well as residual water levels (sea level anomalies) originating from the South China Sea. The model is calibrated and its performance extensively assessed against field measurements, resulting in a mean root mean square (RMS) error of below 6% for water levels over the entire Pearl River Delta. The model also represents both the discharge distribution over the river network and salinity transport processes with good accuracy, resolving the discharge distribution over the main branches of the river network within 5% of reported annual mean values and RMS errors for salinity in the range of 2 ppt (dry season) to 5 ppt (wet season).
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.)
Directory of Open Access Journals (Sweden)
Karim Bagha
2011-08-01
Full Text Available Generative semantics is (or perhaps was a research program within linguistics, initiated by the work of George Lakoff, John R. Ross, Paul Postal and later McCawley. The approach developed out of transformational generative grammar in the mid 1960s, but stood largely in opposition to work by Noam Chomsky and his students. The nature and genesis of the program are a matter of some controversy and have been extensively debated. Generative semanticists took Chomsky's concept of deep structure and ran with it, assuming (contrary to later work by Chomsky and Ray Jackendoff that deep structures were the sole input to semantic interpretation. This assumption, combined with a tendency to consider a wider rang of empirical evidence than Chomskyan linguists, lead generative semanticists to develop considerably more abstract and complex theories of deep structure than those advocated by Chomsky and his students. Throughout the late 1960s and 1970s, there were heated debates between generative semanticists and more orthodox Chomskyans. The generative semanticists lost the debate, in so far as their research program ground to a halt by the 1980s. However, this was in part because the interests of key generative semanticists such as George Lakoff had gradually shifted away from the narrow study of syntax and semantics. A number of ideas from later work in generative semantics have been incorporated into cognitive linguistics (and indeed into main stream Chomskyan linguistics, often without citation
Scientific Electronic Library Online (English)
Julieta, Cabrera; Alcides, López; Ricardo, Vílchez; Hugo, Alarcón; Juan, Rodríguez.
2014-10-01
Full Text Available Estructuras unidimensionales (1D) mesoporosas tipo nanotubos/nanobarras de TiO2 fueron sintetizadas por el método hidrotermal en medio alcalino, empleando como material de inicio nanopartículas de TiO2 obtenidas por el proceso Sol Gel (SG-TiO2). Imágenes obtenidas por Microscopía Electrónica de Barr [...] ido por Emisión de Campo (MEB-EC) y Microscopía Electrónica de Transmisión de Alta Resolución (MET-AR) mostraron la formación de nanoestructuras tipo tubo de 8 nm de diámetro y tamaños mayores a 400 nm de largo luego del tratamiento hidrotermal de 18 y 24 horas; éstas nanoestructuras se conservaron luego del proceso de intercambio iónico con ácido clorhídrico (HCl). Luego de la calcinación, se convirtieron a estructuras tipo barras de TiO2 anatasa como lo muestran los resultados obtenidos por Difracción de Rayos X (DRX). La conversión de nanopartículas a nanotubos y posteriormente a estructuras tipo barras fue también confirmada por la variación en el área superficial BET de alrededor de 201, a 269 y 97 m²/g, respectivamente. Las isotermas de adsorción-desorción revelaron curvas de histéresis típicas de materiales mesoporosos. Estas cualidades resultan atractivas en aplicaciones tales como remoción de contaminantes en agua. Abstract in english Mesoporous one dimensional nanostructures (1D) such as nanotubes/nanorods of TiO2 were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles obtained by Sol Gel process (SG-TiO2). The electronic microscopy images revealed the nanotubes formation of approximately 8 nm in diameter and m [...] ore than around 400 nm long after hydrothermal treatment of 18 h and 24 h. These tube-like structures were maintained after acid treatment but after annealing at 400 °C during 2 hours these turn into rod-like structures of crystalline TiO2 corresponding to anatase phase as revealed the diffraction patterns obtained by X-Ray Diffraction (XRD). The conversion of nanoparticles into nanotubes and afterward into rodlike shape was also confirmed by the variations in the BET surface area from 201, 269 and 97 m²/g around, respectively. The adsorption-desorption isotherms also revealed hysteresis loop typical of mesoporous materials. These qualities are attractive to use these materials for the treatment of pollutants in water, for example.
Arroyo-Torres, B; Chiavassa, A; Scholz, M; Freytag, B; Marcaide, J M; Hauschildt, P H; Wood, P R; Abellan, F J
2015-01-01
We present the atmospheric structure and the fundamental parameters of three red supergiants, 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. We carried out spectro-interferometric observations of 3 RSGs in the near-infrared K-band with the VLTI/AMBER instrument at medium spectral resolution. To comprehend the extended atmospheres, we compared our observational results to predictions by available hydrostatic PHOENIX, available 3-D convection, and new 1-D self-excited pulsation models of RSGs. Our near-infrared flux spectra 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 ...
Nested 1D-2D approach for urban surface flood modeling
Murla, Damian; Willems, Patrick
2015-04-01
Floods in urban areas as a consequence of sewer capacity exceedance receive increased attention because of trends in urbanization (increased population density and impermeability of the surface) and climate change. Despite the strong recent developments in numerical modeling of water systems, urban surface flood modeling is still a major challenge. Whereas very advanced and accurate flood modeling systems are in place and operation by many river authorities in support of flood management along rivers, this is not yet the case in urban water management. Reasons include the small scale of the urban inundation processes, the need to have very high resolution topographical information available, and the huge computational demands. Urban drainage related inundation modeling requires a 1D full hydrodynamic model of the sewer network to be coupled with a 2D surface flood model. To reduce the computational times, 0D (flood cones), 1D/quasi-2D surface flood modeling approaches have been developed and applied in some case studies. In this research, a nested 1D/2D hydraulic model has been developed for an urban catchment at the city of Gent (Belgium), linking the underground sewer (minor system) with the overland surface (major system). For the overland surface flood modelling, comparison was made of 0D, 1D/quasi-2D and full 2D approaches. The approaches are advanced by considering nested 1D-2D approaches, including infiltration in the green city areas, and allowing the effects of surface storm water storage to be simulated. An optimal nested combination of three different mesh resolutions was identified; based on a compromise between precision and simulation time for further real-time flood forecasting, warning and control applications. Main streets as mesh zones together with buildings as void regions constitute one of these mesh resolution (3.75m2 - 15m2); they have been included since they channel most of the flood water from the manholes and they improve the accuracy of interactions within the 1D sewer network. Other areas that recorded flooding outside the main streets have been also included with the second mesh resolution for an accurate determination of flood maps (12.5m2 - 50m2). Permeable areas have been identified and used as infiltration zones using the Horton infiltration model. A mesh sensitivity analysis has been performed for the low flood risk areas for a proper model optimization. As outcome of that analysis, the third mesh resolution has been chosen (75m2 - 300m2). Performance tests have been applied for several synthetic design storms as well as historical storm events displaying satisfactory results upon comparing the flood mapping outcomes produced by the different approaches. Accounting for the infiltration in the green city spaces reduces the flood extents in the range 39% - 68%, while the average reduction in flood volume equals 86%. Acknowledgement: Funding for this research was provided by the Interreg IVB NWE programme (project RainGain) and the Belgian Science Policy Office (project PLURISK). The high resolution topographical information data were obtained from the geographical information service AGIV; the original full hydrodynamic sewer network model from the service company Farys, and the InfoWorks licence from Innovyze.
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
Vabbina, Phani Kiran; Kaushik, Ajeet; Pokhrel, Nimesh; Bhansali, Shekhar; Pala, Nezih
2015-01-15
We report on label free, highly sensitive and selective electrochemical immunosensors based on one-dimensional 1D ZnO nanorods (ZnO-NRs) and two-dimensional 2D ZnO nanoflakes (ZnO-NFs) which were synthesized on Au-coated substrates using simple one step sonochemical approach. Selective detection of cortisol using cyclic voltammetry (CV) is achieved by immobilizing anti-cortisol antibody (Anti-C(ab)) on the ZnO nanostructures (NSs). 1D ZnO-NRs and 2D ZnO-NFs provide unique sensing advantages over bulk materials. While 1D-NSs boast a high surface area to volume ratio, 2D-NSs with large area in polarized (0001) plane and high surface charge density could promote higher Anti-C(ab) loading and thus better sensing performance. Beside large surface area, ZnO-NSs also exhibit higher chemical stability, high catalytic activity, and biocompatibility. TEM studies showed that both ZnO-NSs are single crystalline oriented in (0001) plane. The measured sensing parameters are in the physiological range with a sensitivity of 11.86 µA/M exhibited by ZnO-NRs and 7.74 µA/M by ZnO-NFs with the lowest detection limit of 1 pM which is 100 times better than conventional enzyme-linked immunosorbant immunoassay (ELISA). ZnO-NSs based cortisol immunosensors were tested on human saliva samples and the performance were validated with conventional (ELISA) method which exhibits a remarkable correlation. The developed sensors can be integrated with microfluidic system and miniaturized potentiostat for point-of-care cortisol detection and such developed protocol can be used in personalized health monitoring/diagnostic. PMID:25064820
Klimeck, Gerhard
2001-03-01
The quantum mechanical functionality of commercially pursued heterostructure devices such as resonant tunneling diodes (RTDs), quantum well infrared photodetectors, and quantum well lasers are enabled by material variations on an atomic scale. The creation of these heterostructure devices is realized in a vast design space of material compositions, layer thicknesses and doping profiles. The full experimental exploration of this design space is unfeasible and a reliable design tool is needed. The Nanoelectronic Modeling tool (NEMO) is one of the first commercial grade attempts for such a modeling tool. NEMO was developed as a general-purpose quantum mechanics-based 1-D device design and analysis tool from 1993-97 by the Central Research Laboratory of Texas Instruments (later Raytheon Systems). NEMO enables(R. Lake, G. Klimeck, R. C. Bowen, and D. Jovanovic, J. Appl. Phys. 81), 7845 (1997). the fundamentally sound inclusion of the required(G. Klimeck et al.), in the 1997 55th Annual Device Research Conference Digest, (IEEE, NJ, 1997), p. 92^,(R. C. Bowen et al.), J. Appl. Phys 81, 3207 (1997). physics: bandstructure, scattering, and charge self-consistency based on the non-equilibrium Green function approach. A new class of devices which require full 3-D quantum mechanics based models is starting to emerge: quantum dots, or in general semiconductor based deca-nano devices. We are currently building a 3-D modeling tool based on NEMO to include the important physics to understand electronic stated in such superscaled structures. This presentation will overview various facets of the NEMO 1-D tool such electron transport physics in RTDs, numerical technology, software engineering and graphical user interface. The lessons learned from that work are now entering the NEMO 3-D development and first results using the NEMO 3-D prototype will be shown. More information about the publically available NEMO 1-D executables can be found at http://hpc.jpl.nasa.gov/ PEP/gekco/nemo
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.
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)
Uncalibrated 1D Projective Camera and 3D Affine Reconstruction of Lines
Quan, Long
1997-01-01
We describe a linear algorithm to recover 3D affine shape/motion from line correspondences over three views with uncalibrated affine cameras. The key idea is the introduction of a one-dimensional projective camera. This converts the 3D affine reconstruction of "lines" into 2D projective reconstruction of "points". Using the full tensorial representation of three uncalibrated 1D views, we prove that the 3D affine reconstruction of lines from minimal data is unique up to a re-ordering of the vi...
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.
A deconstruction lattice description of the D1/D5 brane world-volume gauge theory
Joel Giedt
2006-01-01
In this article, I generalize the deconstruction lattice formulation of Endres and Kaplan [hep-lat/0604012] to two-dimensional super-QCD with eight supercharges, denoted (4,4), and bifundamental matter. I specialize to a particularly interesting (4,4) gauge theory, with gauge group U(N_c) \\times U(N_f), and U(N_f) weakly gauged. It describes the infrared limit of the D1/D5 brane system, which has been studied extensively as an example of the AdS_3/CFT_2 correspondence. The c...
Reactive scattering of O(1D)+HD: Product speed and angle distributions
International Nuclear Information System (INIS)
The reaction dynamics of O(1D)+HD ? OH+D and OD+H was investigated at a collision energy of 4.55 kcal/mole in a crossed-beam apparatus. The speed and angle distributions of H(D) products were interrogated using Doppler-shift measurements in a (1+1) REMPI (resonantly enhanced multiphoton ionization) detection scheme. Both product channels exhibited marked forward--backward asymmetry in the angular distributions and the translational energy release to the OD+H channel was substantially larger, about 1.4 on the average, than that to the OH+D product. copyright 1995 American Institute of Physics
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.
Complete classification of 1D gapped quantum phases in interacting spin systems
Chen, Xie; Gu, Zheng-Cheng; Wen, Xiao-Gang
2011-01-01
Quantum phases with different orders exist with or without breaking the symmetry of the system. Recently, a classification of gapped quantum phases which do not break time reversal, parity or on-site unitary symmetry has been given for 1D spin systems in [X. Chen, Z.-C. Gu, and X.-G. Wen, Phys. Rev. B \\textbf{83}, 035107 (2011); arXiv:1008.3745]. It was found that, such symmetry protected topological (SPT) phases are labeled by the projective representations of the symmetry ...
Magnetothermoelectric effects in Fe{1+d}Te{1-x}Se{x}
Matusiak, Marcin; Pomjakushina, Ekaterina; Conder, Kazimierz
2012-01-01
We report resistivity as well as the Hall, Seebeck and Nernst coefficients data for Fe{1+d}Te{1-x}Se{x} single crystals with x = 0, 0.38, and 0.40. In the parent compound Fe{1.04}Te we observe at Tn = 61 K a sudden change of all quantities studied, which can be ascribed to the Fermi surface reconstruction due to onset of the antiferromagnetic order. Two very closely doped samples: Fe{1.01}Te{0.62}Se{0.38} (Se38) and Fe{1.01}Te{0.60}Se{0.40} (Se40) are superconductors with Tc...
D1/D5 system and Wilson Loops in (Non-)commutative Gauge Theories
TAKAHASHI, HIDENORI; Nakajima, Tadahito; SUZUKI, Kenji
2002-01-01
We study the behavior of the Wilson loop in the (5+1)-dimensional supersymmetric Yang-Mills theory with the presence of the solitonic object. Using the dual string description of the Yang-Mills theory that is given by the D1/D5 system, we estimate the Wilson loops both in the temporal and spatial cases. For the case of the temporal loop, we obtain the velocity dependent potential. For the spatial loop, we find that the area law is emerged due to the effect of the D1-branes. ...
Prediction of car cabin environment by means of 1D and 3D cabin model
Fišer, J.; Pokorný, J.; Jícha, M.
2012-04-01
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 tools are demonstrated on the example of the car cabin and the results from simulations are compared with the results from the real car cabin climate chamber measurements.
Prediction of car cabin environment by means of 1D and 3D cabin model
Directory of Open Access Journals (Sweden)
Jícha M.
2012-04-01
Full Text Available 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 tools are demonstrated on the example of the car cabin and the results from simulations are compared with the results from the real car cabin climate chamber measurements.
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.
B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction
Shin, Jung Hoon; Park, Se-Ho
2013-01-01
CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a d...
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.
Anti-cytokine therapies in T1D : Concepts and strategies
DEFF Research Database (Denmark)
Nepom, Gerald T; Ehlers, Mario
2013-01-01
Therapeutic targeting of proinflammatory cytokines is clinically beneficial in several autoimmune disorders. Several of these cytokines are directly implicated in the pathogenesis of type 1 diabetes, suggesting opportunities for design of clinical trials in type 1 diabetes that incorporate selective cytokine blockade as a component of preventative or interventional immunotherapy. The rationale and status of inhibitory therapy directed against IL-1, TNF, IL-12, IL-23, and IL-6 are discussed, towards a goal of using cytokine inhibition as a therapeutic platform to establish an in vivo milieu suitable for modulating the immune response in T1D.
Symmetries of star products and metric universalities in 1D quadri-modal maps
International Nuclear Information System (INIS)
Star products in symbolic dynamics of 1D quadri-modal maps are presented, the complexity of substitution rules is discussed besides their inherent cyclic and dual properties. Feigenbaum's metric universalities in bifurcations of period-n-tupling sequences are calculated by the new numerical method of the word-lifting technique for quadri-modal maps. It is known that symmetries of dynamic behavior are pretty different between even-modal maps and odd-modal maps, the former has central symmetric property in phase space. This paper provide a complete example to obtain star products of even-modal maps
An elementary derivation of first and last return times of 1D random walks
Kostinski, Sarah
2015-01-01
Random walks, and in particular, their first passage times, are ubiquitous in nature. Using direct enumeration of paths, we find the first return time distribution of a 1D random walker, which is a heavy-tailed distribution with infinite mean. Using the same method we find the last return time distribution, which follows the arcsine law. Both results have a broad range of applications in physics and other disciplines. The derivation presented here is readily accessible to physics undergraduates, and provides an elementary introduction into random walks and their intriguing properties.
Neutralizing monoclonal antibody against enterovirus-70 reacts with viral proteins 1C and 1D.
Wiley, J A; Brodeur, B R; Dimock, K D; Sattar, S A
1990-01-01
A library of murine monoclonal antibodies against the prototype Enterovirus-70 (EV-70) strain, J670/71, was made for the purpose of studying the immunologically reactive determinants of the virus. Each of the monoclonal antibodies reacted with several other strains of Enterovirus-70 when tested by immunofluorescence. However, none of these monoclonal antibodies reacted with any other picornavirus tested. It was found that all of the monoclonal antibodies precipitated EV-70 viral proteins 1C and 1D in radio-immunoprecipitation assays. However, only one of these monoclonal antibodies, an IgG3 kappa, was capable of neutralizing the virus. PMID:1694428
Collective mode damping and viscosity in a 1D unitary Fermi gas
Punk, M.; Zwerger, W.
2006-01-01
We calculate the damping of the Bogoliubov-Anderson mode in a one-dimensional two-component attractive Fermi gas for arbitrary coupling strength within a quantum hydrodynamic approach. Using the Bethe-Ansatz solution of the 1D BCS-BEC crossover problem, we derive analytic results for the viscosity covering the full range from a Luther-Emery liquid of weakly bound pairs to a Lieb-Liniger gas of strongly bound bosonic dimers. At the unitarity point, the system is a Tonks-Girar...
All the supersymmetric solutions of N=1,d=5 ungauged supergravity
Bellorín Romero, Jorge Alejandro; Meessen, Patrick; Ortín Miguel, Tomás
2006-01-01
We classify the supersymmetric solutions of ungauged N = 1 d = 5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordström black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be r...
Light-induced crystallization of cold atoms in a 1D optical trap.
Grießer, Tobias; Ritsch, Helmut
2013-08-01
Collective off-resonant scattering of coherent light by a cold gas induces long-range interactions via interference of light scattered by different particles. In a 1D configuration, these interactions grow particularly strong by coupling the particles via an optical nanofiber. Above a threshold pump laser intensity, we predict a phase transition from a homogeneous density to a self-sustained crystalline order. In the dispersive regime, we determine the critical condition for the onset of order as well as the forms of gas density and electric field patterns above threshold. Surprisingly, there can coexist multiple ordered states with distinct appearances. PMID:23952420
Gas Sensing Performances of Copper Oxide Films and Quasi 1-D Nanoarchitectures
Barreca, D.; Comini, E.; Gasparotto, A.; Maccato, C.; Sberveglieri, G.; Tondello, E.
2009-05-01
Supported copper oxide nanosystems were synthesized by Chemical Vapor Deposition (CVD) on Al2O3 substrates. A progressive evolution from polycrystalline Cu2O nanodeposits to CuO samples with an entangled quasi 1-D morphology occurred upon increasing the growth temperature from 350 to 550° C. Gas sensing performances in the detection of Volatile Organic Compounds (VOCs; e.g. CH3COCH3, CH3CH2OH) revealed appreciable responses even at moderate temperatures, with characteristics directly dependent on the system composition and nano-organization.
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.
Refractive index sensor based on a 1D photonic crystal in a microfluidic channel
Mogensen, Klaus B.; Kutter, Jörg P.; Niels Asger Mortensen; Pedro S. Nunes
2010-01-01
A refractive index sensor has been fabricated in silicon oxynitride by standard UV lithography and dry etching processes. The refractive index sensor consists of a 1D photonic crystal (PhC) embedded in a microfluidic channel addressed by fiber-terminated planar waveguides. Experimental demonstrations performed with several ethanol solutions ranging from a purity of 96.00% (n = 1.36356) to 95.04% (n = 1.36377) yielded a sensitivity (??/?n) of 836 nm/RIU and a limit of detection (LOD) of 6 x 10...
International Nuclear Information System (INIS)
We investigate the effect of next-nearest-neighbor hopping on topological quantum phase transitions (QPTs) that are characterized by the number of Majorana zero modes in one-dimensional (1D) p-wave superconducting systems. We also numerically analyze the scaling behavior and the universality of the Berry phase (BP) of the ground state close to the critical point. For critical line (I), the derivative of the ground-state BP is nonanalytic at the phase boundaries. For the phase boundary (II), a noncontractible BP of the ground state itself is also a witness of quantum phase transition. (letter)
Design for manufacturability from 1D to 4D for 90-22 nm technology nodes
Balasinski, Artur
2013-01-01
This book explains integrated circuit design for manufacturability (DfM) at the product level (packaging, applications) and applies engineering DfM principles to the latest standards of product development at 22 nm technology nodes.Â It is a valuable guide for layout designers, packaging engineers and quality engineers, covering DfM development from 1D to 4D, involving IC design flow setup, best practices, links to manufacturing and product definition, for process technologies down to 22 nm node, and product families including memories, logic, system-on-chip and system-in-package.
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
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...
Lysophospholipid presentation by CD1d and recognition by a human Natural Killer T-cell receptor
Energy Technology Data Exchange (ETDEWEB)
López-Sagaseta, Jacinto; Sibener, Leah V.; Kung, Jennifer E.; Gumperz, Jenny; Adams, Erin J. (UC); (UW-MED)
2014-10-02
Invariant Natural Killer T (iNKT) cells use highly restricted {alpha}{beta} T cell receptors (TCRs) to probe the repertoire of lipids presented by CD1d molecules. Here, we describe our studies of lysophosphatidylcholine (LPC) presentation by human CD1d and its recognition by a native, LPC-specific iNKT TCR. Human CD1d presenting LPC adopts an altered conformation from that of CD1d presenting glycolipid antigens, with a shifted {alpha}1 helix resulting in an open A pocket. Binding of the iNKT TCR requires a 7-{angstrom} displacement of the LPC headgroup but stabilizes the CD1d-LPC complex in a closed conformation. The iNKT TCR CDR loop footprint on CD1d-LPC is anchored by the conserved positioning of the CDR3{alpha} loop, whereas the remaining CDR loops are shifted, due in part to amino-acid differences in the CDR3{beta} and J{beta} segment used by this iNKT TCR. These findings provide insight into how lysophospholipids are presented by human CD1d molecules and how this complex is recognized by some, but not all, human iNKT cells.
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.
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)
Fuel temperature estimation of MATRA code for SPERT-1D plate fuel during RIA
International Nuclear Information System (INIS)
In transient analysis, heat flux is not directly given but derived from heat conduction in fuel using heat source supplied by neutronics. The conduction in MATRA code computes internal temperature distributions within heat conducting material and the surface heat fluxes to adjacent fluid channels. In conduction, orthogonal collocation is employed to an approximate polynomial solution with residuals method. Typical subchannel codes developed to design the commercial LWR are mainly performed to validate on the rod type with ceramic fuel. On the contrary, there are few validations on the plate type with metal fuel. SPERT-1D test with a metal fuel of plate type generally used in the was to measure the fuel centerline and surface temperature during power transients by RIA. Validations of the plate type fuel temperature calculation of MATRA code are performed to compare the SPERT-1D test results using equal heat transfer coefficient model. Fuel model of MATRA code was estimated to compare the fuel centerline and surface temperature with the transient experimental results. For the sake of estimating a pool boiling using subchannel code, equal heat transfer coefficient model was developed. The main idea of the model substitutes the pool boiling condition to the equal forced convection heat transfer coefficient neglecting the detail flow condition
Unveiling the Role of CNTs on the Phase Formation of 1D Ferroelectrics
Mahajan, Amit
2015-05-21
Carbon nanotubes (CNTs) have the potential to act as templates or bottom electrodes for three dimension (3D) capacitor arrays, which utilise one dimension (1D) ferroelectric nanostructures to increase memory size and density. However, growing a ferroelectric on the surface of CNTs is non-trivial. Here, we demonstrate that multi-walled (MW) CNTs decrease the time and temperature for formation of lead zirconium titanate Pb(Zr1-xTix)O3 (PZT) by ~100 ºC commensurate with a decrease in activation energy from 68±15 kJ/mol to 27±2 kJ/mol. As a consequence, monophasic PZT was obtained at 575 ºC for MWCNTs/PZT whereas for pure PZT traces of pyrochlore were still present at 650 ºC, where PZT phase formed due to homogeneous nucleation. The piezoelectric nature of MWCNT/PZT synthesised at 500 ºC for 1 h was proved. Although further work is required to prove the concept of 3D capacitor arrays, our result suggests that it is feasible to utilise MWCNTs as templates/electrodes for the formation of 1D PZT nano ferroelectrics.
Analytical solutions for quantum walks on 1D chain with different shift operators
International Nuclear Information System (INIS)
In this paper, we study the discrete-time quantum walks on 1D Chain with the moving and swapping shift operators. We derive analytical solutions for the eigenvalues and eigenstates of the evolution operator U-hat using the Chebyshev polynomial technique, and calculate the long-time averaged probabilities for the two different shift operators respectively. It is found that the probability distributions for the moving and swapping shift operators display completely different characteristics. For the moving shift operator, the probability distribution exhibits high symmetry where the probabilities at mirror positions are equal. The probabilities are inversely proportional to the system size N and approach to zero as N??. On the contrary, for the swapping shift operator, the probability distribution is not symmetric, the probability distribution approaches to a power-law stationary distribution as N?? under certain coin parameter condition. We show that such power-law stationary distribution is determined by the eigenstates of the eigenvalues ±1 and calculate the intrinsic probability for different starting positions. Our findings suggest that the eigenstates corresponding to eigenvalues ±1 play an important role for the swapping shift operator. - Highlights: • QWs on 1D chain with the moving and swapping operators are studied for the first time. • We derive analytical results for the probability distribution for the two operators. •We compare the dynamics of QWs with two different shift operators. • We find the particular eigenvalues ±1 play an important role for the dynamics. • We use the Chebyshev technique to treat the problem
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...
Quasinormal modes of (anti-)de Sitter black holes in the 1 /D expansion
Emparan, Roberto; Suzuki, Ryotaku; Tanabe, Kentaro
2015-04-01
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 mode.
Bogoliubov coefficients for the twist operator in the D1D5 CFT
Carson, Zaq; Mathur, Samir D.; Turton, David
2014-12-01
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 call the 'continuum limit'. The method uses Bogoliubov coefficients to compute the effect of the twist operator in this limit. For bosonic fields, we use the method to reproduce recent results describing the effect of the twist operator when it links together CFT copies with windings M and N, producing a copy of winding M + N. We also comment on possible generalizations of our results. The methods developed here may help in understanding the twist interaction at higher orders. This in turn should provide insight into the thermalization process in the D1D5 CFT, which gives a holographic description of black hole formation.
A woven 2D touchpad sensor and a 1D slide sensor using soft capacitor fibers
International Nuclear Information System (INIS)
Recently reported soft conductive-polymer-based capacitor fibers are used to build a fully woven 2D touchpad sensor and a 1D slide sensor. An individual capacitor fiber features a swiss-roll like structure having two dielectric and two conductive polymer films rolled together in a classic multilayer capacitor configuration. The soft fibers of sub-1 mm outer diameter are fabricated using a fiber drawing procedure from a macroscopic polymeric preform. An individual capacitor fiber is then demonstrated to act as a distributed sensor that allows the touch position to be determined by measuring the fiber’s AC response. In other words, a single fiber acts as a 1D slide sensor. Furthermore, we develop an electrical ladder network model to predict the distributed sensor properties of an individual fiber and show that this model describes the experimental measurements very well. Finally, a two-dimensional touchpad sensor is presented. The sensor is built by weaving a one-dimensional array of capacitor fibers in parallel to each other. The performance of the touchpad sensor is then characterized. (paper)
Analytical solutions for quantum walks on 1D chain with different shift operators
Energy Technology Data Exchange (ETDEWEB)
Xu, Xin-Ping, E-mail: xuxp@mail.ihep.ac.cn [School of Physical Science and Technology, Soochow University, Suzhou 215006 (China); Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Zhang, Xiao-Kun [School of Physical Science and Technology, Soochow University, Suzhou 215006 (China); Ide, Yusuke [Department of Information Systems Creation, Faculty of Engineering, Kanagawa University, Yokohama, Kanagawa 221-8686 (Japan); Konno, Norio [Department of Applied Mathematics, Faculty of Engineering, Yokohama National University, Hodogaya, Yokohama 240-8501 (Japan)
2014-05-15
In this paper, we study the discrete-time quantum walks on 1D Chain with the moving and swapping shift operators. We derive analytical solutions for the eigenvalues and eigenstates of the evolution operator U{sup -hat} using the Chebyshev polynomial technique, and calculate the long-time averaged probabilities for the two different shift operators respectively. It is found that the probability distributions for the moving and swapping shift operators display completely different characteristics. For the moving shift operator, the probability distribution exhibits high symmetry where the probabilities at mirror positions are equal. The probabilities are inversely proportional to the system size N and approach to zero as N??. On the contrary, for the swapping shift operator, the probability distribution is not symmetric, the probability distribution approaches to a power-law stationary distribution as N?? under certain coin parameter condition. We show that such power-law stationary distribution is determined by the eigenstates of the eigenvalues ±1 and calculate the intrinsic probability for different starting positions. Our findings suggest that the eigenstates corresponding to eigenvalues ±1 play an important role for the swapping shift operator. - Highlights: • QWs on 1D chain with the moving and swapping operators are studied for the first time. • We derive analytical results for the probability distribution for the two operators. •We compare the dynamics of QWs with two different shift operators. • We find the particular eigenvalues ±1 play an important role for the dynamics. • We use the Chebyshev technique to treat the problem.
Synthesis of 1D regular arrays of gold nanoparticles and modeling of their optical properties.
Dmitruk, N; Barlas, T; Dmytruk, A; Korovin, A; Romanyuk, V
2008-02-01
Self-organized formation of uniform coating of semiconductor substrate by metal nanoparticles offers a convenient and efficient access to large-scale arrays of uniform metal-semiconductor nanostructures. We used a cheap and facile method of photoinduced chemical gold deposition from an aqueous or alcohol gold salt solution onto semiconductor surface (GaAs, InP). By controlling of both the solution composition and the deposition conditions, gold particles of 10-50 nm in diameter were obtained and the gold covering degree of the semiconductor surface was varied in a wide range. Morphology of the nano/micro structures formed was characterized by atomic force microscopy and scanned electron microscopy with local element analysis. The investigations show that the semiconductor surface patterning can be used for the selective deposition of gold nanoparticles, because they are located predominantly at the tops of the microrelief. We have used specially textured by the anisotropic chemical etching microrelief surfaces of semiconductor single crystal as templates and have obtained nanoparticle arrays in the shape of 1D systems of near parallel quasiperiodical wires. For the periodic 1D array of metal nanowires built into the air-semiconductor interface the spectral and angular dependencies of the transmittance/reflectance of the polarized light have been obtained theoretically using differential formalism. These dependencies demonstrate non-monotonic behaviour at surface plasmon polariton excitation conditions and show possibility of designing functional subwavelength devices. PMID:18464371
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.
A mass-conservative finite volume predictor-corrector solution of the 1D Richards' equation
Lai, Wencong; Ogden, Fred L.
2015-04-01
Numerical solution of the Richards' equation (RE) in variably saturated soils continues to be a challenge due to its highly non-linear behavior. This is particularly true as soils approach saturation and the behavior of the fundamental partial differential equation changes from elliptic to parabolic. In this paper, a finite volume predictor-corrector method with adaptive time-stepping was developed to solve the 1D vertical RE. The numerical method was mass-conservative and non-iterative. In the predictor step, the pressure head-based form of the RE was solved using the cell-centered finite volume method and the pressure head was updated. In the corrector step, the soil water content was calculated by solving the mixed form RE. Five different schemes to evaluate the inter-cell hydraulic conductivity were investigated. The robustness and accuracy of the numerical model were demonstrated through simulation of experimental tests, including free drainage, field infiltration into wet and dry soils, and laboratory infiltration with falling water table. Numerical results were compared against laboratory measurements, simulation results from the Hydrus-1D program, or analytical solution when available. Results showed that the developed scheme is robust and accurate in simulating variably saturated flows with various boundary conditions. The arithmetic mean and Szymkiewicz's mean of inter-cell hydraulic conductivity performed better than other methods especially in the case of infiltration into very dry soil.
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
Controlled switching of surface waves in 1D photonic crystals by a thin nonlinear cap layer
Hajian, H.; Soltani-Vala, A.; Kalafi, M.
2010-12-01
In this paper, we investigate the electromagnetic surface waves localized at the interface of the homogeneous dielectric medium and a semi-infinite one-dimensional photonic crystal (1D PC), theoretically. The semi-infinite 1D PC is made of alternative layers of left-handed (LH) and right-handed (RH) materials in the presence of a thin nonlinear cap layer. We consider magnetic permeability and electric permittivity of LH layers being dispersive and non-dispersive. We used an analytical direct matching procedure within the Kronig-Penny model to analyze the dispersion behavior of surface waves with controllable localization. It is shown that the thin nonlinear cap layer acts as a tool to change the backward surface waves to forward ones and vice versa and it plays an important role on the localization of them. Also we show that when the LH layers are chosen dispersive, negative dispersion of surface waves are obtained in a wide range of radiation angle and frequency, and we propose an approach to calculate the applied electric field intensity that leads to switching of surface waves from backward to forward and creating a surface mode with maximum localization.
A world-line framework for 1D Topological Conformal sigma-models
Baulieu, L; Toppan, F
2015-01-01
We use world-line methods for pseudo-supersymmetry to construct $sl(2|1)$-invariant actions for the $(2,2,0)$ chiral and ($1,2,1)$ real supermultiplets of the twisted $D$-module representations of the $sl(2|1)$ superalgebra. The derived one-dimensional topological conformal $\\sigma$-models are invariant under nilpotent operators. The actions are constructed for both parabolic and hyperbolic/trigonometric realizations (with extra potential terms in the latter case). The scaling dimension $\\lambda$ of the supermultiplets defines a coupling constant, $2\\lambda+1$, the free theories being recovered at $\\lambda=-\\frac{1}{2}$. We also present, generalizing previous works, the $D$-module representations of one-dimensional superconformal algebras induced by ${\\cal N}=(p,q)$ pseudo-supersymmetry acting on $(k,n,n-k)$ supermultiplets. Besides $sl(2|1)$, we obtain the superalgebras $A(1,1)$, $D(2,1;\\alpha)$, $D(3,1)$, $D(4,1)$, $A(2,1)$ from $(p,q)= (1,1), (2,2), (3,3), (4,4), (5,1)$, at given $k,n$ and critical values ...
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.
Quasi-1D physics in metal-organic frameworks: MIL-47(V from first principles
Directory of Open Access Journals (Sweden)
Danny E. P. Vanpoucke
2014-10-01
Full Text Available 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.
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.
Ordered 1-D and 2-D InAs/InP quantum dot arrays at telecom wavelength
International Nuclear Information System (INIS)
Lateral one-dimensional (1-D) and two-dimensional (2-D) InAs/InP quantum dot (QD) arrangements are created by the concept of self-organized anisotropic strain engineering of InAs/InGaAsP superlattice (SL) templates on InP (100) and (311)B substrates by chemical-beam epitaxy (CBE). The SL templates comprise several-periods of an InAs QD layer plus a thin cap layer, post-growth annealing, and a separation layer. QDs order on top of the templates due to local strain recognition. Distinct preferential In adatom surface migration during annealing and substrate miscut lead to linear QD arrays along [001] for InP (100) substrates and a periodic square lattice aligned ±450 off [-233] for InP (311)B substrates. Optimization of the growth parameters balances In desorption and leads to well-separated and highly uniform QD arrays. Importantly, strong photoluminescence (PL) of defect-free InAs QD arrays is observed with the wavelength tuned into the 1.55-?im telecom region at room temperature through the insertion of GaAs interlayer beneath the QDs. Finally, the concept of self-organized anisotropic strain engineering for QD ordering is extended for formation of more complex architectures by combining it with step-engineering on shallow- and deep-patterned substrates. On the sidewall areas, the steps generated by the artificial patterns play the major role in determination of the In adatom surface migration during annealing, altering the QD arrays direction away from [001] on stripe-patterned InP (100) substrates. On the contrary, the sidewalls on patterned InP (311)B are faceted, not affecting the orientation of the 2-D InAs QD arrays.
Ordered 1-D and 2-D InAs/InP quantum dot arrays at telecom wavelength
Energy Technology Data Exchange (ETDEWEB)
Sritirawisarn, N; Otten, F W M van; Noetzel, R, E-mail: n.sritirawisarn@tue.n [COBRA Research Institute on Communication Technology, Eindhoven University of Technology, 5600MB Eindhoven (Netherlands)
2010-09-01
Lateral one-dimensional (1-D) and two-dimensional (2-D) InAs/InP quantum dot (QD) arrangements are created by the concept of self-organized anisotropic strain engineering of InAs/InGaAsP superlattice (SL) templates on InP (100) and (311)B substrates by chemical-beam epitaxy (CBE). The SL templates comprise several-periods of an InAs QD layer plus a thin cap layer, post-growth annealing, and a separation layer. QDs order on top of the templates due to local strain recognition. Distinct preferential In adatom surface migration during annealing and substrate miscut lead to linear QD arrays along [001] for InP (100) substrates and a periodic square lattice aligned {+-}45{sup 0} off [-233] for InP (311)B substrates. Optimization of the growth parameters balances In desorption and leads to well-separated and highly uniform QD arrays. Importantly, strong photoluminescence (PL) of defect-free InAs QD arrays is observed with the wavelength tuned into the 1.55-{mu}im telecom region at room temperature through the insertion of GaAs interlayer beneath the QDs. Finally, the concept of self-organized anisotropic strain engineering for QD ordering is extended for formation of more complex architectures by combining it with step-engineering on shallow- and deep-patterned substrates. On the sidewall areas, the steps generated by the artificial patterns play the major role in determination of the In adatom surface migration during annealing, altering the QD arrays direction away from [001] on stripe-patterned InP (100) substrates. On the contrary, the sidewalls on patterned InP (311)B are faceted, not affecting the orientation of the 2-D InAs QD arrays.
2011-08-10
...DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [TD 9475] RIN 1545-BF83 Corporate Reorganizations; Distributions Under Sections 368(a)(1)(D) and 354(b)(1)(B); Correction AGENCY:...
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 verb...
Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods
Ali, A. Md; Solomatine, D. P.; Di Baldassarre, G.
2015-01-01
Topographic data, such as digital elevation models (DEMs), are essential input in flood inundation modelling. DEMs can be derived from several sources either through remote sensing techniques (spaceborne or airborne imagery) or from traditional methods (ground survey). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle Radar Topography Mission (SRTM), the light detection and ranging (lidar), and topographic contour maps are some of the most commonly used sources of data for DEMs. These DEMs are characterized by different precision and accuracy. On the one hand, the spatial resolution of low-cost DEMs from satellite imagery, such as ASTER and SRTM, is rather coarse (around 30 to 90 m). On the other hand, the lidar technique is able to produce high-resolution DEMs (at around 1 m), but at a much higher cost. Lastly, contour mapping based on ground survey is time consuming, particularly for higher scales, and may not be possible for some remote areas. The use of these different sources of DEM obviously affects the results of flood inundation models. This paper shows and compares a number of 1-D hydraulic models developed using HEC-RAS as model code and the aforementioned sources of DEM as geometric input. To test model selection, the outcomes of the 1-D models were also compared, in terms of flood water levels, to the results of 2-D models (LISFLOOD-FP). The study was carried out on a reach of the Johor River, in Malaysia. The effect of the different sources of DEMs (and different resolutions) was investigated by considering the performance of the hydraulic models in simulating flood water levels as well as inundation maps. The outcomes of our study show that the use of different DEMs has serious implications to the results of hydraulic models. The outcomes also indicate that the loss of model accuracy due to re-sampling the highest resolution DEM (i.e. lidar 1 m) to lower resolution is much less than the loss of model accuracy due to the use of low-cost DEM that have not only a lower resolution, but also a lower quality. Lastly, to better explore the sensitivity of the 1-D hydraulic models to different DEMs, we performed an uncertainty analysis based on the GLUE methodology.
Reymond, Philippe; Perren, Fabienne; Lazeyras, François; Stergiopulos, Nikos
2012-10-11
One-dimensional models of the systemic arterial tree are useful tools for studying wave propagation phenomena, however, their formulation for frictional losses is approximate and often based on solutions for developed flow in straight non-tapered arterial segments. Thus, losses due to bifurcations, tortuosity, non-planarity and complex geometry effects cannot be accounted for in 1-D models. This may lead to errors in the estimation of mean pressure. To evaluate these errors, we simulated steady flow in a patient specific model of the entire systemic circulation using a standard CFD code with Newtonian and non-Newtonian blood properties and compared the pressure evolution along three principal and representative arterial pathlines with the prediction of mean pressure, as given by the 1-D model. Pressure drop computed from aortic root up to iliac bifurcation and to distal brachial is less than 1 mmHg and 1-D model predictions agree well with the 3-D model. In smaller vessels like the precerebral and cerebral arteries, the losses are higher (mean pressure drop over 10 mmHg from mean aortic pressure) and are consistently underestimated by the 1-D model. Complex flow patterns resulting from tortuosity, non-planarity and branching yield shear stresses, which are higher than the ones predicted by the 1-D model. In consequence, the 1-D model overestimates mean pressure in peripheral arteries and especially in the cerebral circulation. PMID:22884968
Heindl, Claudia; Peresypkina, Eugenia V; Virovets, Alexander V; Komarov, Vladislav Yu; Scheer, Manfred
2015-06-14
The potential of K[P3C2R2] (R = (t)Bu, Mes) as building blocks in metallo-supramolecular chemistry was investigated and self-assembly processes with Cu(i) halides resulted in the formation of a large variety of unprecedented one-, two- and even three-dimensional aggregates. The 3D networks showed an interesting topological similarity to allotropes of carbon: diamond and the theoretically proposed polybenzene. Furthermore, the negative charge of the phospholyl ligand favoured the generation of cationic CuaXb (a > b, X = Cl, Br, I) assemblies, a challenging area within the well-studied coordination chemistry of CuX units. In addition, the 1D strands were also characterized in solution, revealing the presence of oligomeric units. PMID:25960365
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Potts, J. R.; Harris, S.; Giuggioli, L.
2011-12-01
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 propagator 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 propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed.
An anti-symmetric exclusion process for two particles on an infinite 1D lattice
Energy Technology Data Exchange (ETDEWEB)
Potts, J R; Giuggioli, L [Bristol Centre for Complexity Sciences, University of Bristol, Bristol (United Kingdom); Harris, S, E-mail: jonathan.potts.08@bris.ac.uk [School of Biological Sciences, University of Bristol, Bristol (United Kingdom)
2011-12-02
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 propagator 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 propagator is found and is shown to solve a Fokker-Planck equation for two biased, mutually exclusive Brownian particles with equal and opposite drift velocity. Connections to territorial dynamics in animal populations are discussed. (paper)
Survey of Multi-Material Closure Models in 1D Lagrangian Hydrodynamics
Energy Technology Data Exchange (ETDEWEB)
Maeng, Jungyeoul Brad [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hyde, David Andrew Bulloch [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-07-28
Accurately treating the coupled sub-cell thermodynamics of computational cells containing multiple materials is an inevitable problem in hydrodynamics simulations, whether due to initial configurations or evolutions of the materials and computational mesh. When solving the hydrodynamics equations within a multi-material cell, we make the assumption of a single velocity field for the entire computational domain, which necessitates the addition of a closure model to attempt to resolve the behavior of the multi-material cells’ constituents. In conjunction with a 1D Lagrangian hydrodynamics code, we present a variety of both the popular as well as more recently proposed multi-material closure models and survey their performances across a spectrum of examples. We consider standard verification tests as well as practical examples using combinations of fluid, solid, and composite constituents within multi-material mixtures. Our survey provides insights into the advantages and disadvantages of various multi-material closure models in different problem configurations.
Marica, Aurora
2014-01-01
This work describes the propagation properties of the so-called symmetric interior penalty discontinuous Galerkin (SIPG) approximations of the 1-d wave equation. This is done by means of linear approximations on uniform meshes. First, a careful Fourier analysis is constructed, highlighting the coexistence of two Fourier spectral branches or spectral diagrams (physical and spurious) related to the two components of the numerical solution (averages and jumps). Efficient filtering mechanisms are also developed by means of techniques previously proved to be appropriate for classical schemes like finite differences or P1-classical finite elements. In particular, the work presents a proof that the uniform observability property is recovered uniformly by considering initial data with null jumps and averages given by a bi-grid filtering algorithm. Finally, the book explains how these results can be extended to other more sophisticated conforming and non-conforming finite element methods, in particular to quad...
Improvement of the axial diffusion solver of DeCART employing 1-D transport solution
International Nuclear Information System (INIS)
Instead of the 3-D transport equation, DeCART solves a transverse leakage coupled radial transport and axial diffusion equations to obtain an approximate 3-D transport solution. In this paper, two of the approximations contained in DeCART related with diffusion constants and cell homogenization are exmained, and practical improvement schemes are suggested. To overcome the diffusion approximation used in the axial direction, a current conservation scheme based on the axial 1-D transport solution is introduced. To overcome the cell homogenization effect, a plane height refinement scheme is employed near the axial core/reflector boundary where homogenization constants vary significantly in the axial direction within the plane. These schemes are evaluated by solving the 3-D VENUS-2 MOX core benchmark. The current conservation and plane height refinement schemes bring about 280 pcm and 100 pcm improvement in k-eff, respectively, and about 390 pcm in total, but trivial effects in the power distribution
Reduction formula for fermion loops and density correlations of the 1D Fermi gas
Neumayr, A; Neumayr, Arne; Metzner, Walter
1999-01-01
Fermion N-loops with an arbitrary number of density vertices N > d+1 in d spatial dimensions can be expressed as a linear combination of (d+1)-loops with coefficients that are rational functions of external momentum and energy variables. A theorem on symmetrized products then implies that divergencies of single loops for low energy and small momenta cancel each other when loops with permuted external variables are summed. We apply these results to the one-dimensional Fermi gas, where an explicit formula for arbitrary N-loops can be derived. The symmetrized N-loop, which describes the dynamical N-point density correlations of the 1D Fermi gas, does not diverge for low energies and small momenta. We derive the precise scaling behavior of the symmetrized N-loop in various important infrared limits.
Refractive Index Sensor Based on a 1D Photonic Crystal in a Microfluidic Channel
Directory of Open Access Journals (Sweden)
Klaus B. Mogensen
2010-03-01
Full Text Available A refractive index sensor has been fabricated in silicon oxynitride by standard UV lithography and dry etching processes. The refractive index sensor consists of a 1D photonic crystal (PhC embedded in a microfluidic channel addressed by fiber-terminated planar waveguides. Experimental demonstrations performed with several ethanol solutions ranging from a purity of 96.00% (n = 1.36356 to 95.04% (n = 1.36377 yielded a sensitivity (??/?n of 836 nm/RIU and a limit of detection (LOD of 6 x 10-5 RIU, which is, however, still one order of magnitude higher than the theoretical lower limit of the limit of detection 1.3 x 10–6 RIU.
1D3V PIC simulation of propagation of relativistic electron beam in an inhomogeneous plasma
Shukla, Chandrashekhar; Patel, Kartik
2015-01-01
A recent experimental observation has shown efficient transport of Mega Ampere of electron currents through aligned carbon nanotube arrays [Phys. Rev Letts. 108, 235005 (2012)]. The result was subsequently interpreted on the basis of suppression of the filamentation instability in an inhomogeneous plasma [Phys. Plasmas 21, 012108 (2014)]. This inhomogeneity forms as a result of the ionization of the carbon nanotubes. In the present work a full 1D3V Particle-in-Cell (PIC) simulations have been carried out for the propagation of relativistic electron beams (REB) through an inhomogeneous background plasma. The suppression of the filamentation instability, responsible for beam divergence, is shown. The simulation also confirms that in the nonlinear regime too the REB propagation is better when it propagates through a plasma whose density is inhomogeneous transverse to the beam. The role of inhomogeneity scale length, its amplitude and the transverse beam temperature etc., in the suppression of the instability is ...
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).
Pressure Sensor via Optical Detection Based on a 1D Spin Transition Coordination Polymer
Directory of Open Access Journals (Sweden)
C?t?lin M. Jureschi
2015-01-01
Full Text Available We have investigated the suitability of using the 1D spin crossover coordination polymer [Fe(4-(2’-hydroxyethyl-1,2,4-triazole3]I2?H2O, known to crossover around room temperature, as a pressure sensor via optical detection using various contact pressures up to 250 MPa. A dramatic persistent colour change is observed. The experimental data, obtained by calorimetric and Mössbauer measurements, have been used for a theoretical analysis, in the framework of the Ising-like model, of the thermal and pressure induced spin state switching. The pressure (P-temperature (T phase diagram calculated for this compound has been used to obtain the P-T bistability region.
Quantum simulation of 2D topological physics in a 1D array of optical cavities.
Luo, Xi-Wang; Zhou, Xingxiang; Li, Chuan-Feng; Xu, Jin-Shi; Guo, Guang-Can; Zhou, Zheng-Wei
2015-01-01
Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration. PMID:26145177
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.
Verification and comparison of four numerical schemes for a 1D viscoelastic blood flow model
Wang, Xiaofei; Lagrée, Pierre-Yves
2013-01-01
In this paper, we present four numerical schemes for a 1D viscoelastic blood flow model. In the case with a small nonlinearity (small amplitude of wave), asymptotic analysis predicts several behaviours of the wave: propagation in a uniform tube, attenuation of the amplitude due to the skin friction, diffusion due to the viscosity of the wall, and reflection and transmission at a branching point. These predictions are compared very favorably with all of the numerical solutions. The schemes are also tested in case with a larger nonlinearity. Finally, we apply all of the schemes on a relatively realistic arterial system with 55 arteries. The schemes are compared in four aspects: the spatial and temporal convergence speed, the ability to capture shock phenomena, the computation speed and the complexity of the implementation. The suitable conditions for the application of the various schemes are discussed.
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
Sixth Order Multiple Coarse Grid Computation for Solving 1D Partial Differential Equation
Directory of Open Access Journals (Sweden)
Yin Wang
2014-11-01
Full Text Available We present a new method using multiple coarse grid computation technique to solve one dimensional (1D partialdifferential equation (PDE. Our method is based on a fourth order discretization scheme on two scale grids andthe Richardson extrapolation. For a particular implementation, we use multiple coarse grid computation to computethe fourth order solutions on the fine grid and all the coarse grids. Since every fine grid point has a correspondingcoarse grid point with fourth order solution, the Richardson extrapolation procedure is applied for every fine gridpoint to increase the order of solution accuracy from fourth order to sixth order. We compare the maximum absoluteerror and the order of solution accuracy for our new method, the standard fourth order compact (FOC scheme andWang-Zhang’s sixth order multiscale multigrid method. Two convection-diffusion problems are solved numericallyto validate our proposed method.
Holographic description of non-supersymmetric orbifolded D1-D5-P solutions
Chakrabarty, Bidisha; Virmani, Amitabh
2015-01-01
Non-supersymmetric black hole microstates are of great interest in the context of the black hole information paradox. We identify the holographic description of the general class of non-supersymmetric orbifolded D1-D5-P supergravity solutions found by Jejjala, Madden, Ross and Titchener. This class includes both completely smooth solutions and solutions with conical defects, and in the near-decoupling limit these solutions describe degrees of freedom in the cap region. The CFT description involves a general class of states obtained by fractional spectral flow in both left-moving and right-moving sectors, generalizing previous work which studied special cases in this class. We compute the massless scalar emission spectrum and emission rates in both gravity and CFT and find perfect agreement, thereby providing strong evidence for our proposed identification. We also investigate the physics of ergoregion emission as pair creation for these orbifolded solutions. Our results represent the largest class of non-supe...
A consistent approach for deriving a 1D constitutive equation for shape memory alloys
International Nuclear Information System (INIS)
One of the first 1D constitutive equations for shape memory alloys (SMA) was presented by Brinson; it became the basis for later works, typically. In Brinson's equation, several proposed functions are considered in order to simplify the model and obtain the constitutive equation for SMA. In a recent paper, Buravalla and Khandelwal have shown certain anomalies in Brinson's model and have tried to present a modified model which unlike Brinson's model satisfies the compatibility condition. However, their formulation, besides being lengthy, lacks clarity and in particular does not address proper expressions for transformation tensors. In the present work, Brinson's constitutive equation is derived from fundamental relations using a simple, clear-cut and straightforward approach. Without any extra and unnecessary assumption the modified transformation tensors are derived from original definitions. The new expressions are compared with those of Brinson and the consistency of the model is confirmed. (technical note)
Engineering and manipulating Majorana bound states in 1D quantum wires
International Nuclear Information System (INIS)
Recently, the interest in topological quantum computing has grown due to the appearance of promising platforms for realizing the long sought Majorana bound states. Among the proposals that appear suitable for engineering the Majorana bound states, the most prominent involves a 1D semiconducting quantum wire in proximity to a bulk s-wave superconductor, where in addition a Zeeman magnetic field is applied. In this work, we investigate the possibility of performing qubit operations via the adiabatic variation of certain internal parameters without using any external gates or network of wires. The crucial feature of our model is the combination and interplay of phases for the magnetic field and the superconducting order parameter. In an appropriate junction setup, we explore the possible phase configurations that could lead to a Majorana bound state exchange.
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...
A new subgenotype 2.1d isolates of classical swine fever virus in China, 2014.
Zhang, Hongliang; Leng, Chaoliang; Feng, Liping; Zhai, Hongyue; Chen, Jiazeng; Liu, Chunxiao; Bai, Yun; Ye, Chao; Peng, Jinmei; An, Tongqing; Kan, Yunchao; Cai, Xuehui; Tian, Zhijun; Tong, Guangzhi
2015-08-01
The lapinized attenuated vaccine against classical swine fever (CSF) has been used in China for over half a century and has generally prevented large-scale outbreaks in recent years. However, since late 2014, a large number of new cases of CSF were detected in many immunized pig farms in China. Several of these CSV viruses were isolated and characterized. Phylogenetic and genomic sequence analyses indicate that these new isolates, as well as some reference isolates, form a new subgenotype named 2.1d, and share several consistent molecular characteristics. Since these new isolates emerged in disparate geographic regions within 5months, this suggests that these isolates may be widespread. Given that current vaccines do not appear to provide effective protection against this new subgenotype, further investigation of these strains is urgently needed. PMID:26031602
Quantum simulation of 2D topological physics in a 1D array of optical cavities
Luo, Xi-Wang; Zhou, Xingxiang; Li, Chuan-Feng; Xu, Jin-Shi; Guo, Guang-Can; Zhou, Zheng-Wei
2015-07-01
Orbital angular momentum of light is a fundamental optical degree of freedom characterized by unlimited number of available angular momentum states. Although this unique property has proved invaluable in diverse recent studies ranging from optical communication to quantum information, it has not been considered useful or even relevant for simulating nontrivial physics problems such as topological phenomena. Contrary to this misconception, we demonstrate the incredible value of orbital angular momentum of light for quantum simulation by showing theoretically how it allows to study a variety of important 2D topological physics in a 1D array of optical cavities. This application for orbital angular momentum of light not only reduces required physical resources but also increases feasible scale of simulation, and thus makes it possible to investigate important topics such as edge-state transport and topological phase transition in a small simulator ready for immediate experimental exploration.
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)
Asymptotically stable solutions of 1-D space-time kinetics in the presence of delayed neutrons
International Nuclear Information System (INIS)
The non-linear 1-D reactor kinetics equations in the presence of delayed neutrons with Newtonian feedback have been solved analytically for a slab homogeneous reactor for a step input of reactivity using a perturbation theory expansion. The asymptotic limit of the fundamental mode has been found to be the same with and without the inclusion of delayed neutrons in the analysis. However, the rate at which the limit is approached is many order slower in the presence of delayed neutrons than in their absence. The threshold values of initial power for the occurrence of oscillations are also found to be higher in the presence of delayed neutrons for the three types of reference reactors considered. (author)
Asymptotically stable solutions of 1-D space-time kinetics in the presence of delayed neutrons
Energy Technology Data Exchange (ETDEWEB)
Gupta, H.P.; Trasi, M.S.
1984-01-01
The non-linear 1-D reactor kinetics equations in the presence of delayed neutrons with Newtonian feedback have been solved analytically for a slab homogeneous reactor for a step input of reactivity using a perturbation theory expansion. The asymptotic limit of the fundamental mode has been found to be the same with and without the inclusion of delayed neutrons in the analysis. However, the rate at which the limit is approached is many order slower in the presence of delayed neutrons than in their absence. The threshold values of initial power for the occurrence of oscillations are also found to be higher in the presence of delayed neutrons for the three types of reference reactors considered.
Toward a consistent use of overshooting parametrizations in 1D stellar evolution codes
Viallet, Maxime; Prat, Vincent; Arnett, David
2015-01-01
Several parametrizations for overshooting in 1D stellar evolution calculations coexist in the literature. These parametrizations are used somewhat arbitrarily in stellar evolution codes, based on what works best for a given problem, or even for historical reasons related to the development of each code. We bring attention to the fact that these different parametrizations correspond to different physical regimes of overshooting, depending whether the effects of radiation are dominant, marginal, or negligible. Our analysis is based on previously published theoretical results, as well as multidimensional hydrodynamical simulations of stellar convection where the interaction between the convective region and a stably-stratified region is observed. Although the underlying hydrodynamical processes are the same, the outcome of the overshooting process is profoundly affected by radiative effects. Using a simple picture of the scales involved in the overshooting process, we show how three regimes are obtained, dependi...
Jakas, Mario M
2011-01-01
The Rayleigh-Modal method is used to calculate the electromagnetic field within the grooves of a perfectly conducting, rectangular-shaped 1D diffraction grating. An \\emph{enhancement coefficient} ($\\eta$) is introduced in order to quantify such an energy concentration. Accordingly, $\\eta >$1 means that the amount of electromagnetic energy present within the grooves is larger than that one will have, over the same volume, if the diffraction grating is replaced by a perfectly reflecting mirror. The results in this paper show that $\\eta$ can be as large as several decades at certain, often narrow, ranges of wavelengths. However, it reduces to approximately 20% under sunlight illumination. In this latter case, such values are achieved when the \\textit{optical spacing} between the grooves $dn$ is greater than 500 nm, where $d$ is the groove spacing and $n$ is the refractive index of the substance within the grooves. For $dn$ smaller than 500 nm the enhancement coefficient turns negligibly small.
Development of input structure software for MARS 1D-3D graphic user interface
International Nuclear Information System (INIS)
A user-friendly Input Software for MARS 1D-3D GUI called MARA (MARS Adjunct Reactor Assembler) has been developed. Extension of the current MARA to the overall input system for MARS will result in an integrated commercial GUI comparable to those for computational analysis codes ANSYS, ABAQUS, FLUENT and CFX. MARA will help accelerate marketing of MARS and other potential system analysis codes to developing countries in Southeast Asia planning to put nuclear power in their electrical grids. MARS code and associated developmental technology are in the process of being disseminated to twenty-two organizations spanning the industry, academia and laboratories across the country. MARA will find its way to practical applications in a variety of engineering problems
Quantum propagation and confinement in 1D systems using the transfer-matrix method
International Nuclear Information System (INIS)
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. (paper)
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.
Canonical quantization of nonlocal theories related to bosonization in 2 + 1D
International Nuclear Information System (INIS)
We present a canonical formulation for theories whose actions contain non-integer powers of the d'Alembertian operator and which were recently shown to play a central role in 2 + 1D bosonization. We show that these theories possess an infinite number of constraints and use the Dirac method in order to obtain the classical brackets. The casual and classical Green functions are obtained and their meaning in terms of field expectation values is discussed. The Wightman functions are introduced and shown to lead to the microcausality principle. A mode expansion for the field is obtained. This permits the reobtention of the Wightman functions as vacuum expectation values of products of the basic fields. Creation and annihilation operators are naturally introduced but, as shown, they are not related to definite mass particle states. This is also confirmed by the spectral decomposition of the Wightman functions. (author). 16 refs, 1 fig
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.
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...
Staggered grid leap-frog scheme for the (2+1)D Dirac equation
Hammer, René
2013-01-01
A numerical scheme utilizing a grid which is staggered in both space and time is proposed for the numerical solution of the (2+1)D Dirac equation in presence of an external electromagnetic potential. It preserves the linear dispersion relation of the free Weyl equation for wave vectors aligned with the grid and facilitates the implementation of open (absorbing) boundary conditions via an imaginary potential term. This explicit scheme has second order accuracy in space and time. A functional for the norm is derived and shown to be conserved. Stability conditions are derived. Several numerical examples, ranging from generic to specific to textured topological insulator surfaces, demonstrate the properties of the scheme which can handle general electromagnetic potential landscapes.
General behavior for the condensation of an interacting Bose gas in an 1D optical lattice
Energy Technology Data Exchange (ETDEWEB)
Hassan, Ahmed S., E-mail: ahmedhassan117@yahoo.co [Department of Physics, Faculty of Science, El Minia University, El Minia (Egypt)
2010-09-01
The general behavior of the condensation of an interacting Bose gas in a combined 3D magnetic potential with 1D optical potential is theoretically investigated. A simple analytical procedure based on a piecewise density of states is used to calculate the condensate fraction and the critical temperature for this system. The calculated results showed that the condensation in this system can be founded in three different quantum phases. Transition between them are identified by the condensate fraction behavior as a function of lattice depth and the reduced temperature. I have presented results over a wide parameter regime appropriate to current experiments at NIST and ENS. The calculated results are in a good agreement with the experimental measured data of Spielman et al. (2008).
Statistics of scattered photons from a driven three-level emitter in 1D open space
Energy Technology Data Exchange (ETDEWEB)
Roy, Dibyendu [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bondyopadhaya, Nilanjan [Integrated Science Education and Research Centre, Visva-Bharati University, Santiniketan (India)
2014-01-07
We derive the statistics of scattered photons from a - or ladder-type three-level emitter (3LE) embedded in a 1D open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency (EIT) which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as strength of the control beam is ramped up from zero to a higher value where the ATS appears.
Refractive index sensor based on a 1D photonic crystal in a microfluidic channel
DEFF Research Database (Denmark)
Rodrigues de Sousa Nunes, Pedro André; Mortensen, Asger
2010-01-01
A refractive index sensor has been fabricated in silicon oxynitride by standard UV lithography and dry etching processes. The refractive index sensor consists of a 1D photonic crystal (PhC) embedded in a microfluidic channel addressed by fiber-terminated planar waveguides. Experimental demonstrations performed with several ethanol solutions ranging from a purity of 96.00% (n = 1.36356) to 95.04% (n = 1.36377) yielded a sensitivity (??/?n) of 836 nm/RIU and a limit of detection (LOD) of 6 x 10-5 RIU, which is, however, still one order of magnitude higher than the theoretical lower limit of the limit of detection 1.3 x 10–6 RIU.
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...
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.
Bosonization, cocycles, and the D1-D5 CFT on the covering surface
Burrington, Benjamin A; Zadeh, Ida G
2015-01-01
We consider the D1-D5 CFT near the orbifold point, specifically the computation of correlators involving twist sector fields using covering surface techniques. As is well known, certain twists introduce spin fields on the cover. Here we consider the bosonization of fermions to facilitate computations involving the spin fields. We find a set of cocycle operators that satisfy constraints coming from various $SU(2)$ symmetries, including the $SU(2)_L\\times SU(2)_R$ R-symmetry. Using these cocycles, we consider the correlator of four spin fields on the cover, and show that it is invariant under all of the $SU(2)$ symmetries of the theory. We consider the mutual locality of operators, and compute several three-point functions. These computations lead us to a notion of radial ordering on the cover that is inherited from the original computation before lifting. Further, we note that summing over orbifold images sets certain branch-cut ambiguous correlators to zero.
Magnet Free Generators - 3rd Generation Wind Turbine Generators
DEFF Research Database (Denmark)
Jensen, Bogi Bech; Mijatovic, Nenad
2013-01-01
This paper presents an introduction to superconducting wind turbine generators, which are often referred to as 3rd generation wind turbine generators. Advantages and challenges of superconducting generators are presented with particular focus on possible weight and efficiency improvements. A comparison of the rare earth usage in different topologies of permanent magnet generators and superconducting generators is also presented.
Community interactive webtool to retrieve Greenland glacier data for 1-D geometry
Perrette, Mahé
2015-04-01
Marine-terminating, outlet glaciers are challenging to include in conventional Greenland-wide ice sheet models because of the large variation in scale between model grid size (typically 10 km) and outlet glacier width (typically 1-5km), making it a subgrid scale feature. A possible approach to tackle this problem is to use one-dimensional flowline models for the individual glaciers (e.g. Nick et al., 2013, Nature; Enderlin et al 2013a,b, The Cryosphere). Here we present a python- and javascript- based webtool to prepare data required to feed in or validate a flowline model. It is designed primarily to outline the glacier geometry and returns relevant data averaged over cross-sections. The tool currently allows to: visualize 2-D ice sheet data (zoom/pan), quickly switch between datasets (e.g. ice thickness, bedrock elevation, surface velocity) interpolated / transformed on a common grid. draw flowlines from user-input seeds on the map, calculated from a vector field of surface velocity, as an helpful guide for point 3 interactively draw glacier outline (side and middle lines) on top of the data mesh the outlined glacier domain in the horizontal plane extract relevant data into a 1-D longitudinal profile download the result as a netCDF file The project is hosted on github to encourage collaboration, under the open-source MIT Licence. The server-side is written in python (open-source) using the web-framework flask, and the client-side (javascript) makes use of the d3 library for interactive figures. For now it only works locally in a web browser (start server: "python runserver.py"). Data need to be downloaded separately from the original sources. See the README file in the project for information how to use it. Github projects: https://github.com/perrette/webglacier1d (main) https://github.com/perrette/dimarray (dependency)
Signal-noise separation based on self-similarity testing in 1D-timeseries data
Bourdin, Philippe A.
2015-08-01
The continuous improvement of the resolution delivered by modern instrumentation is a cost-intensive part of any new space- or ground-based observatory. Typically, scientists later reduce the resolution of the obtained raw-data, for example in the spatial, spectral, or temporal domain, in order to suppress the effects of noise in the measurements. In practice, only simple methods are used that just smear out the noise, instead of trying to remove it, so that the noise can nomore be seen. In high-precision 1D-timeseries data, this usually results in an unwanted quality-loss and corruption of power spectra at selected frequency ranges. Novel methods exist that are based on non-local averaging, which would conserve much of the initial resolution, but these methods are so far focusing on 2D or 3D data. We present here a method specialized for 1D-timeseries, e.g. as obtained by magnetic field measurements from the recently launched MMS satellites. To identify the noise, we use a self-similarity testing and non-local averaging method in order to separate different types of noise and signals, like the instrument noise, non-correlated fluctuations in the signal from heliospheric sources, and correlated fluctuations such as harmonic waves or shock fronts. In power spectra of test data, we are able to restore significant parts of a previously know signal from a noisy measurement. This method also works for high frequencies, where the background noise may have a larger contribution to the spectral power than the signal itself. We offer an easy-to-use software tools set, which enables scientists to use this novel technique on their own noisy data. This allows to use the maximum possible capacity of the instrumental hardware and helps to enhance the quality of the obtained scientific results.
Characterization and thermal stability of cobalt-modified 1-D nanostructured trititanates
International Nuclear Information System (INIS)
One-dimensional (1-D) nanostructured sodium trititanates were obtained via alkali hydrothermal method and modified with cobalt via ion exchange at different Co concentrations. The resulting cobalt-modified trititanate nanostructures (Co-TTNS) were characterized by TGA, XRD, TEM/SAED, DRS-UV-Vis and N2 adsorption techniques. Their general chemical formula was estimated as NaxCoy/2H2-x-yTi3O7.nH2O and they maintained the same nanostructured and multilayered nature of the sodium precursor, with the growth direction of nanowires and nanotubes along [010]. As a consequence of the Co2+ incorporation replacing sodium between trititanate layers, two new diffraction lines became prominent and the interlayer distance was reduced with respect to that of the precursor sodium trititanate. Surface area was slightly increased with cobalt intake whereas pore size distribution was hardly affected. Besides, Co2+ incorporation in trititanate crystal structure also resulted in enhanced visible light photon absorption as indicated by a strong band-gap narrowing. Morphological and structural thermal transformations of Co-TTNS started nearly 400 deg. C in air and the final products after calcination at 800 deg. C were found to be composed of TiO2-rutile, CoTiO3 and a bronze-like phase with general formula Na2xTi1-xCoxO2. - GraphCoxO2. - Graphical abstract: Co2+ incorporation in 1D-trititanate crystal nanostructure (Co-TTNS) causes reduction in interlayer distance by comparison with its sodium precursor (Na-TTNS) and leads to enhanced visible light photon absorption efficiency due to a strong band-gap narrowing
Influence of Surface Waves on Plasma High Harmonic Generation
der Brügge, Daniel an; Kumar, Naveen; Pukhov, Alexander; Rödel, Christian
2011-01-01
The influence of surface plasma waves (SPW) on high harmonic generation (HHG) from the interaction of intense lasers with overdense plasma is analyzed. It is shown, that the surface waves lead to the emission of harmonics away from the optical axis. These off-axis harmonics violate the parity selection rules found from 1D models. Further, our investigations in the highly relativistic regime point towards the existence of a new SPW generation process.
Donchev, Todor I. (Urbana, IL); Petrov, Ivan G. (Champaign, IL)
2011-05-31
Described herein is an apparatus and a method for producing atom clusters based on a gas discharge within a hollow cathode. The hollow cathode includes one or more walls. The one or more walls define a sputtering chamber within the hollow cathode and include a material to be sputtered. A hollow anode is positioned at an end of the sputtering chamber, and atom clusters are formed when a gas discharge is generated between the hollow anode and the hollow cathode.
Nunn, Scott; Larkin, DJ; Singh, Alvin; Ferguson, Karen
2013-01-01
Generation Rent is a special public storytelling night and panel discussion that will close a year of affordable housing reporting by the Tyee Solutions Society, supported with grant funding from the Real Estate Foundation of BC. ?The night will feature a set of short, image-driven presentations by local renters about what they value about their homes. Presenters will also share what challenges they experience as renters in Vancouver. Following the renters' presentations, panelists will ...
Frog2: Efficient 3D conformation ensemble generator for small compounds
Miteva, Maria A; Guyon, Frederic; Tufféry, Pierre
2010-01-01
Frog is a web tool dedicated to small compound 3D generation. Here we present the new version, Frog2, which allows the generation of conformation ensembles of small molecules starting from either 1D, 2D or 3D description of the compounds. From a compound description in one of the SMILES, SDF or mol2 formats, the server will return an ensemble of diverse conformers generated using a two stage Monte Carlo approach in the dihedral space. When starting from 1D or 2D description of compounds, Frog...
Directory of Open Access Journals (Sweden)
Deininger Martina
2013-01-01
Full Text Available Numerical simulations of complete hydraulic systems (e.g. diesel injectors can, due to high computational costs, currently not be done entirely in three dimensions. Our aim is to substitute the 3D solver by a corresponding 1D method in some parts of the system and develop a solver coupling with suitable interface models. Firstly, we investigate an interface model for non-cavitating flow passing the interface. A flux-coupling with a thin interface approach is considered and the jump in dimensions at the interface is transferred to an additional variable ?, which switches between the 3D and the 1D domain. As shown in two testcases, the error introduced in the vicinity of the interface is quite small. Two numerical flux formulations for the flux over the 3D-1D interface are compared and the Roe-type flux formulation is recommended. Secondly, extending the first method to cavitating flows passing the interface, we divide the density equation in two equations - one for liquid and one for vapor phase of the two-phase fluid - and couple the two equations by source terms depending on the free enthalpy. We propose two interface models for coupling 3D and 1D compressible density-based Euler methods that have potential for considering the entire (non- cavitating hydraulic system behaviour by a 1D method in combination with an embedded detailed 3D simulation at much lower computational costs than the pure 3D simulation.
Organization and expression of the Co1D-CA23 plasmid genes associated with colicin synthesis
International Nuclear Information System (INIS)
The authors have investigated the organization and regulation of the functioning of colicin genes, the immunity protein, and lysis protein of the colicinogenic plasmid Co1D-CA23. In addition they have analyzed the polypeptides synthesized in minicells carrying plasmid Co1D, its Th5 mutants, and the recombinant plasmids obtained on cloning of the EcoRV fragments of Co1D on vector BR325. They have determined the position of the promoter of the colicin gene and the direction of its transcription. Furthermore they were able to show that the gene determining cell immunity to colicin D is transcribed independently of the colicin gene from its own SOS-independent promoter. Treatment of the cells carrying plasmid Co1D with mitomycin C leads to the induction of synthesis of not only colicin but also of a protein with a molecular weight of 10 kdalton, causing under these conditions the death and lysis of the cells. Together with colicin, this protein is detected in the culture liquid on lysis of the cells. Plasmid mutations impairing the synthesis of the lysis protein inhibit the release of colicin into the medium. They have shown that the genes of colicin and the lysis protein are arranged into one operon, the lysis gene being transcribed after the colicin gene. They have proposed a genetic map for plasmid Co1D-CA23
Organization and expression of the Co1D-CA23 plasmid genes associated with colicin synthesis
Energy Technology Data Exchange (ETDEWEB)
Pshennikova, E.S.; Lipasova, V.A.; Kolot, M.N.; Khmel' , I.A.
1986-11-01
The authors have investigated the organization and regulation of the functioning of colicin genes, the immunity protein, and lysis protein of the colicinogenic plasmid Co1D-CA23. In addition they have analyzed the polypeptides synthesized in minicells carrying plasmid Co1D, its Th5 mutants, and the recombinant plasmids obtained on cloning of the EcoRV fragments of Co1D on vector BR325. They have determined the position of the promoter of the colicin gene and the direction of its transcription. Furthermore they were able to show that the gene determining cell immunity to colicin D is transcribed independently of the colicin gene from its own SOS-independent promoter. Treatment of the cells carrying plasmid Co1D with mitomycin C leads to the induction of synthesis of not only colicin but also of a protein with a molecular weight of 10 kdalton, causing under these conditions the death and lysis of the cells. Together with colicin, this protein is detected in the culture liquid on lysis of the cells. Plasmid mutations impairing the synthesis of the lysis protein inhibit the release of colicin into the medium. They have shown that the genes of colicin and the lysis protein are arranged into one operon, the lysis gene being transcribed after the colicin gene. They have proposed a genetic map for plasmid Co1D-CA23.
Wang, Hao; Wang, Baoyuan; Yu, Jichao; Hu, Yunxia; Xia, Chen; Zhang, Jun; Liu, Rong
2015-03-01
The single-crystalline TiO2 nanorod arrays with rutile phase have attracted much attention in the dye sensitized solar cells (DSSCs) applications because of their superior chemical stability, better electron transport properties, higher refractive index and low production cost. However, it suffers from a low surface area as compared with TiO2 nanoparticle films. In order to enlarge the surface area of TiO2 nanorod arrays, the 1D nanorods/3D nanotubes sample was synthesized using a facile two-step hydrothermal process involving hydrothermal growth 1D/3D nanorods and followed by post-etching treatment. In such bi-layer structure, the oriented TiO2 nanorods layer could provide direct pathway for fast electron transportation, and the 3D nanotubes layer offers a higher surface area for dye loading, therefore, the 1D nanorods/3D nanotubes photoanode exhibited faster electron transport and higher surface area than either 1D or 3D nanostructures alone, and an highest efficiency of 7.68% was achieved for the DSSCs based on 1D nanorods/3D nanotubes photoanode with further TiCl4 treatment.
A common Greenlandic TBC1D4 variant confers muscle insulin resistance and type 2 diabetes
DEFF Research Database (Denmark)
Moltke, Ida; Grarup, Niels
2014-01-01
The Greenlandic population, a small and historically isolated founder population comprising about 57,000 inhabitants, has experienced a dramatic increase in type 2 diabetes (T2D) prevalence during the past 25 years. Motivated by this, we performed association mapping of T2D-related quantitative traits in up to 2,575 Greenlandic individuals without known diabetes. Using array-based genotyping and exome sequencing, we discovered a nonsense p.Arg684Ter variant (in which arginine is replaced by a termination codon) in the gene TBC1D4 with an allele frequency of 17%. Here we show that homozygous carriers of this variant have markedly higher concentrations of plasma glucose (? = 3.8?mmol?l(-1), P = 2.5?×?10(-35)) and serum insulin (? = 165?pmol?l(-1), P = 1.5?×?10(-20)) 2 hours after an oral glucose load compared with individuals with other genotypes (both non-carriers and heterozygous carriers). Furthermore, homozygous carriers have marginally lower concentrations of fasting plasma glucose (? = -0.18 mmol?l(-1), P= 1.1?×?10(-6)) and fasting serum insulin (? = -8.3?pmol?l(-1), P = 0.0014), and their T2D risk is markedly increased (odds ratio (OR) = 10.3, P = 1.6?×?10(-24)). Heterozygous carriers have a moderately higher plasma glucose concentration 2 hours after an oral glucose load than non-carriers (? = 0.43?mmol?l(-1), P = 5.3?×?10(-5)). Analyses of skeletal muscle biopsies showed lower messenger RNA and protein levels of the long isoform of TBC1D4, and lower muscle protein levels of the glucose transporter GLUT4, with increasing number of p.Arg684Ter alleles. These findings are concomitant with a severely decreased insulin-stimulated glucose uptake in muscle, leading to postprandial hyperglycaemia, impaired glucose tolerance and T2D. The observed effect sizes are several times larger than any previous findings in large-scale genome-wide association studies of these traits and constitute further proof of the value of conducting genetic association studies outside the traditional setting of large homogeneous populations.
International Nuclear Information System (INIS)
Two new Dawson-based phosphotungstates (H2en)0.5H[Cu(en)2(H2O)]2{[Cu(en)2](?1-P2W17CuO61)}.8H2O (1) (en=ethylenediamine) and [4,4'-H2bpy]2{[Cu(4,4'-bpy)3][Cu(4,4'-bpy)4(H2O)2]2[Cu(4,4'-bpy)] [?-P2W18O62]2}.6H2O (2) (4,4'-bpy=4,4'-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the triclinic space group P-1 with a=11.7626(17), b=13.246(2), c=29.350(5) A, ?=87.355(5), ?=79.583(5), ?=66.993(3)o, V=4138.3(11) A3, Z=2, GOF=1.089, R1=0.0563 and wR2=0.1505, whereas 2 belongs to the orthorhombic space group Iba2 with a=22.277(8), b=47.04(2), c=22.153(8) A, V=23215(17) A3, Z=4, GOF=1.051, R1=0.0627 and wR2=0.1477. 1 consists of a 1-D linear chain structure constructed from monocopperII-substituted Dawson polyoxoanions, while 2 represents the first 2-D sheet-like structure with a (4,4)-connected topological net built up from plenary Dawson-type polyoxoanions and CuII-4,4'-bpy complex cations in polyoxometalate chemistry. - Graphical abstract: Two Dawson-based phosphotungstates (H2en)0.5H[Cu(en)2(H2O)]2{[Cu(en)2](?1-P2W17CuO61)}.8H2O (1) and [4,4'-H2bpy]2{[Cu(4,4'-bpy)3] [Cu(4,4'-bpy)4(H2O)2]2[Cu(4,4'-bpy)][?-P2W18O62]2}.6H2O (2) have been hydrothermally synthesized and structurally characterized. 1 consists of a 1-D linear chain structure constructed from monocopper-substituted Dawson polyoxoanions, while 2 represents the first 2-D sheet-like structure with a (4,4)-connected topological net built up from saturated Dawson-type polyoxoanions and CuII-4,4'-bpy complex cations in polyoxometalate chemistry.
International Nuclear Information System (INIS)
In the second half of twentieth century, nuclear power became an industrial reality. Now the operating 433 power plants, the 37 plants under construction, near 9000 years/reactor with only one serious accident with emission of radioactive material to the environment (Chernobyl) show the maturity of this technology. Today nuclear power contribute a 17% to the global generation and an increase of 75 % of the demand of electricity is estimated for 2020 while this demand is expected to triplicate by 2050. How this requirement can be satisfied? All the indicators seems to demonstrate that nuclear power will be the solution because of the shortage of other sources, the increase of the prices of the non renewable fuels and the scarce contribution of the renewable ones. In addition, the climatic changes produced by the greenhouse effect make even more attractive nuclear power. The situation of Argentina is analyzed and compared with other countries. The convenience of an increase of nuclear power contribution to the total national generation seems clear and the conclusion of the construction of the Atucha II nuclear power plant is recommended
Grusche, Sascha
2014-01-01
Spatial-light-modulator (SLM)-based tunable sources have complex setups. A simpler setup, comprising an SLM-projector and a dispersive element, synthesizes light as effectively, based on a Superposition of Newtonian Spectra (SNS). As a generalization of SNS, two-dimensional (2-D) grayscale videos are spectrally encoded on a one-dimensional (1-D), translucent screen, and viewed through another dispersive element. This Projected-Image Circumlineascopy (PICS) produces semitransparent, rainbow-coloured, virtual 2-D videos that face every viewer anywhere around the 1-D screen. They are invariant under reflection of the 1-D screen in mirrors parallel to it. SNS bandwidth and PICS image geometry are calculated using geometric optics and Dispersion Diagrams.
A disordered 1D quantum N-particle system in an environment under the influence of an external field
Energy Technology Data Exchange (ETDEWEB)
Gevorkyan, A S; Gevorkyan, A A [Institute for Informatics and Automation Problems, NAS of Armenia, 1 P Sevak, 0014 Yerevan (Armenia); Oganesyan, K B; Sargsyan, G O; Saakyan, N V, E-mail: bsk@yerphi.a [Yerevan Physics Institute, Alikhanian Brothers 2, Yerevan, RA (Armenia)
2010-09-01
We consider a 1D quantum disordered N-particle system (N-PS) in an external field with relaxation in media. Mathematically, the problem is formulated within the limits of the stochastic differential equation of type Langevin-Schroedinger. Using the Langevin-Schroedinger equation, we found the 2D Fokker-Plank equation that describes the quantum distribution (QD) depending on the energy of nonperturbed 1D N-PS and from the parameters of the external field. The properties of QD are investigated in detail. It is shown that the average value of interaction potentials between the 1D disordered N-PS and the external field has an ultraviolet divergence that is solved by dimensional renormalization.
Numerical solution of the 1D kinetics equations using a cubic reduced nodal scheme
International Nuclear Information System (INIS)
In this work a finite differences technique centered in mesh based on a cubic reduced nodal scheme type finite element to solve the equations of the kinetics 1 D that include the equations corresponding to the concentrations of precursors of delayed neutrons is described. The technique of finite elements used is that of Galerkin where so much the neutron flux as the concentrations of precursors its are spatially approached by means of a three grade polynomial. The matrices of rigidity and of mass that arise during this discretization process are numerically evaluated using the open quadrature non standard of Newton-Cotes and that of Radau respectively. The purpose of the application of these quadratures is the one of to eliminate in the global matrices the couplings among the values of the flow in points of the discretization with the consequent advantages as for the reduction of the order of the matrix associated to the discreet problem that is to solve. As for the time dependent part the classical integration scheme known as ? scheme is applied. After carrying out the one reordering of unknown and equations it arrives to a reduced system that it can be solved but quickly. With the McKin compute program developed its were solved three benchmark problems and those results are shown for the relative powers. (Author)
El-Sheikh, S. M.; Rabah, M. A.
2014-11-01
Calcium chromate 1D-nanorods have been synthesized from tannery waste solution. The solution was filtered to get rid of insoluble matters followed by addition of ammonia to precipitate calcium and chromium as hydroxide gel. The gel was heated within the temperature range 300-600 °C. At 300 °C amorphous phase of calcium chromate was formed. At 400 °C compounds of CaCrO4, Cr2O3, CaCO3 and minor amount of Mg2CO3(OH)2(H2O)3 (Artinite) were detected. At 500 °C, CaCrO4 compound was the major product together with traces of Cr2O3, CaCO3 and MgO. At 600 °C, a crystalline compound of CaCrO4 was formed. Nanorods of calcium chromate structured during heating associated with the crystal growth. Properties of heated products are evaluated with the help of XRD, TEM and FT-IR measurements. Optical properties of the obtained calcium chromate were estimated. A thermodynamic model of the involved reactions is suggested to explore the findings.
Spin-modulated quasi-1D antiferromagnet LiCuVO_4
Büttgen, N; Svistov, L E; Prozorova, L A; Prokofiev, A; Assmus, W
2007-01-01
We report on magnetic resonance studies within the magnetically ordered phase of the quasi-1D antiferromagnet LiCuVO_4. Our studies reveal a spin reorientational transition at a magnetic field H_c1 ~ 25 kOe applied within the crystallographical (ab)-plane in addition to the recently observed one at H_c2 \\~75 kOe [ M.G. Banks et al., cond-mat/0608554 (2006)]. Spectra of the antiferromagnetic resonance (AFMR) along low-frequency branches can be described in the frame of a macroscopic theory of exchange-rigid planar magnetic structures. These data allow to obtain the anisotropy of the exchange interaction together with a constant of the uniaxial anisotropy. Spectra of 7Li nuclear magnetic resonance (NMR) show that, within the magnetically ordered phase of LiCuVO_4 in the low-field range H H_c2 ~ 75 kOe, our NMR spectra simulations show that the magnetically ordered structure exhibits a modulation of the spin projections along the direction of the applied magnetic field H.
Simple-current algebra constructions of 2+1D topological orders
Schoutens, Kareljan
2015-01-01
The possible self-consistent (non-)abelian statistics in 2+1D are classified by modular tensor categories. Using a simplified theory based on fusion coefficients N^{ij}_k and spins s_i, a list of simple (non-)abelian statistics, with rank up to N=7, was produced. However, this list might contain fake entries that do not correspond to valid (non-)abelian statistics, and even valid (non-)abelian statistics might not be realizable by bosonic systems. In this paper, we use simple-current algebra to address this issue. We explicitly construct many-body wave functions, trying to realize the entries in the list (i.e. realize their fusion N^{ij}_k and spins s_i). We find that all entries can be obtained by simple-current algebra plus conjugation under time reversal symmetry. This supports the conjecture that simple-current algebra is a general approach that allows us to produce all (non-)abelian statistics. It also suggests that the simplified theory based on (N^{ij}_k, s_i) is a classifying theory at least for simpl...
VasanthiPillay, V.; Vijayalakshmi, K.
2012-06-01
Low temperature synthesis of Aluminum nitride (AlN) powders through NH4Cl assisted nitridation have been studied by microwave technique. The effect of processing time on the synthesis of AlN powders has been investigated. The optimum processing time was determined to be 120 min at 630 W, 200 °C. The powders were characterized by X-ray diffraction method (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray analyzer (EDS), Fourier transform infrared spectrometer (FTIR) and Impedance analyzer. XRD results revealed that the product has wurtzite phase of AlN. SEM micrographs show a 1D nanorod of AlN with a granular morphology. FTIR spectra exhibit A1 (TO) and E1 (LO) modes of wurtzite AlN. Dielectric properties of the powders were investigated by means of C-V and C-f and ?'-f characteristics. The reported results indicate a reasonable quality of the obtained AlN powders with high dielectric constant, suitable for application in the fabrication of specific electronic devices.
Directory of Open Access Journals (Sweden)
Valérian Guelpa
2014-03-01
Full Text Available 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 high range-to-resolution ratio. The paper presents the measurement principle as well as the processing algorithms (source files are provided as supplementary materials. The theoretical and experimental performances are also discussed. The processing time is around 3 µs for a line of 780 pixels, which means that the measurement rate is mostly limited by the image acquisition frame rate. A 3-? repeatability of 5 nm is experimentally demonstrated which has to be compared with the 168 µm measurement range.
Disorder-induced mutation of quasi-normal modes in 1D open systems
Bliokh, Yury; Nori, Franco
2014-01-01
We study the relation between quasi-normal modes (QNMs) and transmission resonances (TRs) in one-dimensional (1D) disordered systems. We show for the first time that while each maximum in the transmission coefficient is always related to a QNM, the reverse statement is not necessarily correct. There exists an intermediate state, at which only a part of the QNMs are localized and these QNMs provide a resonant transmission. The rest of the solutions of the eigenvalue problem (denoted as strange quasi-modes) are never found in regular open cavities and resonators, and arise exclusively due to random scatterings. Although these strange QNMs belong to a discrete spectrum, they are not localized and not associated with any anomalies in the transmission. The ratio of the number of the normal QNMs to the total number of QNMs is independent of the type of disorder, and slightly deviates from the constant $\\sqrt{2/5}$ in rather large ranges of the strength of a single scattering and the length of the random sample.
1D Modeling of Catalyzed Monopropellant H2O2 Decomposition in Microchannels
Zhou, Xu; Hitt, Darren
2003-11-01
The modeling of the chemical decomposition of hydrogen-peroxide monopropellant flow in a catalytic microchannel is described. This process can be used to provide a micro-propulsion mechanism required for miniaturized satellites (“nanosats”). Based on the largely gaseous nature of the flow and microchannel geometries, a 1D reacting flow model is assumed. The decomposition is modeled by first-order kinetics and a temperature-dependent Arrhenius law; the latter is justified for typical catalysts. Simulations are performed for realistic operating parameters designed to provide thrust levels of 100-500 micro-N. The outcome is a prediction of a critical catalyst chamber length required for complete decomposition; this is shown to depend upon the Damkohler number, Zeldovich number and the non-dimensional heat release rate of the monopropellant. A “thermal detonation” behavior is observed whereby the decomposition process goes to completion instantaneously. Inclusion of heat loss through microchannel walls can significantly increase critical decomposition length and reduce the available energy for the micropropulsion.
Magnetothermoelectric effects in Fe1+dTe1-xSex
International Nuclear Information System (INIS)
We report resistivity as well as the Hall, Seebeck and Nernst coefficients data for Fe1+dTe1-xSex single crystals with x = 0, 0.38, and 0.40. In the parent compound Fe1.04Te we observe at TN = 61 K a sudden change of all quantities studied, which can be described to the Fermi surface reconstruction due to onset of the antiferromagnetic order. Two very closely doped samples: Fe1.01Te0.62Se0.38 (Se38) and Fe1.01Te0.60Se0.40 (Se40) are superconductors with Tc = 13.4 K and 13.9 K, respectively. There are no evident magnetic transitions in either Se38 or Se40. Properties of these two single crystals are almost identical at high temperatures, but start to diverge below T ? 80 K. Perhaps we see the onset of scattering that might be a related to changes in short range magnetic correlations caused by selenium doping.
Cake porosity analysis using 1D-3D fractal dimensions in coagulation-microfiltration of NOM.
Raspati, G S; Leiknes, T O
2015-03-01
Fouling during coagulation-ceramic microfiltration of natural organic matter was investigated. Two process configurations (inline coagulation (IC) and tank coagulation (TC)) and two process conditions (types of coagulants-aluminum-based PAX and iron-based PIX-and G-values) were studied. The rate of irreversible fouling corresponding to the increase of initial transmembrane pressure after backwash of IC-PAX was lowest followed by TC-PAX and TC-PIX, while the performance of IC-PIX was found worst. The 1D and 2D fractal analysis revealed that flocs from IC were morphologically different from those of TC, leading to different filtration characteristics. The 3D fractal analysis revealed two groups of morphologically similar flocs: one led to successful filtration experiments, whereas the other led to unsuccessful ones. Cake porosity was found dependent on the floc morphology. Thus, such an approach was found complementary with fouling analysis by means of a membrane fouling model and minimization of fouling phenomenon was achieved by combining the two approaches. PMID:25768221
Exact quantum dynamics of yrast states in the finite 1D Bose gas
International Nuclear Information System (INIS)
We demonstrate that the quantum dynamics of yrast states in the one-dimensional (1D) Bose gas gives an illustrative example to equilibration of an isolated quantum many-body system. We first formulate the energy spectrum of yrast states in terms of the dressed energy by applying the method of finite-size corrections. We then review the exact time evolution of quantum states constructed from yrast states shown by the Bethe ansatz. In time evolution the density profile of an initially localized quantum state constructed from yrast states collapses into a flat profile in the case of a large particle number such as N = 1000, while recurrence of the localized state occurs in the case of a small particle number such as N = 20. We suggest that the dynamical relaxation behavior for the large N case is consistent with the viewpoint of typicality for generic quantum states: the expectation values of local operators evaluated in most of quantum states are very close to those of the micro-canonical ensemble.
Winkler boundary conditions for three-point bending tests on 1D nanomaterials
International Nuclear Information System (INIS)
Bending tests with atomic force microscopes (AFM) is a common method for elasticity measurements on 1D nanomaterials. Interpretation of the force and deflection data is necessary to determine the Young's modulus of the tested material and has been done assuming either of two classic boundary conditions that represent two extreme possibilities for the rigidity of the sample-anchor interface. The elasticity results from the two boundary conditions differ by a factor of four. Furthermore, both boundary conditions ignore the effects of deflections in the anchors themselves. The Winkler model for beams on elastic foundations is developed here for three-point bending tests to provide a more realistic representation. Equations for computing sample elasticity are derived from two sets of boundary conditions for the Winkler model. Application of this model to interpret the measurement of mechanical stiffness of a silica nanowire at multiple points in a three-point bending is discussed. With the correct choice of boundary conditions, the Winkler model gives a better fit for the observed stiffness profile than the classical beam models while providing a result that differs from both by a factor of two and is comparable to the bulk elasticity.
Variable-range hopping in 2D quasi-1D electronic systems
International Nuclear Information System (INIS)
A semi-phenomenological theory of variable-range hopping (VRH) is developed for two-dimensional (2D) quasi-one-dimensional (quasi-1D) systems such as arrays of quantum wires in the Wigner crystal regime. The theory follows the phenomenology of Efros, Mott and Shklovskii allied with microscopic arguments. We first derive the Coulomb gap in the single-particle density of states, g(?), where ? is the energy of the charge excitation. We then derive the main exponential dependence of the electron conductivity in the linear (L), i.e. ?(T) ? exp [-(TL/T)?L], and current in the non-linear (NL), i.e. j(E) ? [-(ENL/E)?NL], response regimes (E is the applied electric field). Due to the strong anisotropy of the system and its peculiar dielectric properties we show that unusual, with respect to known results, Coulomb gaps open followed by unusual VRH laws, i.e. with respect to the disorder-dependence of TL and ENL and the values of ?L and ?NL. (author)
Robust 1D inversion and analysis of helicopter electromagnetic (HEM) data
DEFF Research Database (Denmark)
TØlbØll, R.J.; Christensen, N.B.
2006-01-01
Ground-based electrical and electromagnetic methods are used systematically for quantitative hydrogeologic investigations in Denmark. In recent years, a desire for faster and more cost-efficient methods has led to growing interest in the possibility of using airborne systems, and in 2001 a number of test flights were performed using a frequency-domain, helicopter-borne electromagnetic (HEM) system. We perform a theoretical examination of the resolution capabilities of the applied system. Quantitative model parameter analyses show that the system only weakly resolves conductive, near-surface layers but can resolve layer boundary to a depth of more than 100 m. Modeling experiments also show that the effect of altimeter errors on the inversion results is serious. We suggest a new interpretation scheme for HEM data founded solely on full nonlinear 1D inversion and providing layered-earth models supported by datamisfit parameters and a quantitative model-parameter analysis. The backbone of the scheme is the removal of cultural coupling effects followed by a multilayer inversion that in turn provides reliable starting models for a subsequent few-layer inversion. A new procedure for correlation in the model space ensures model sections with slow lateral variations in resistivity, normally assumed in sedimentary environments. A field example from a Danish survey demonstrates that the interpretation scheme can produce satisfactory results within the limitations of the system.
Modeling a 1-D bremsstrahlung and neutron imaging array for use on Sandia's Z machine
International Nuclear Information System (INIS)
Inertial confinement fusion is being studied on the Z facility at Sandia National Laboratories. Z is a large z-pinch machine which can provide 20 MA of current to z-pinch loads producing ?1.8 MJ of soft x-rays in less than 10 ns. Within the pinch region, decelerated electrons produce a strong source of bremsstrahlung radiation which varies from shot to shot. Additionally, a variety of ICF targets produce fusion neutrons whose intensity and distribution depend on the temperature and density of the target compression in the pinch. This paper describes the computer modeling behind the shielding design of a simple time-resolved, 1-D imaging array which can provide a time history of both the bremsstrahlung and neutron production as a function of height within the target region. It is demonstrated that by building an array of scintillator fibers separated by long, thin tungsten collimator plates, a spatial resolution of 0.254 mm at the target can be achieved. The corresponding channel-to-channel discrimination for such a design is shown to be better than 1000::1 for <4 MeV photons and 100::1 for 2.45 MeV neutrons. By coupling scintillator fibers to a fiber-optic streak camera system, the signal can also be given as a function of time with a temporal resolution of about 1.2 ns
Architectural control of urea in supramolecular 1D strontium vanadium oxide chains.
Schwarz, Benjamin; Streb, Carsten
2015-03-01
A facile bottom-up approach for the controlled self-assembly of infinite strontium vanadium oxide chains is presented. Two novel one-dimensional strontium-linked polyoxovanadate chains have been isolated by linkage of decavanadate clusters with strontium(ii) ions. To control the architecture dimensions, urea was used as a critical control parameter which allowed tuning of the intra- and intermolecular spacings within the crystal lattice. Using N,N-dimethyl formamide (DMF) and urea as stabilizing ligands, a supramolecular structure, {[Sr(dmf)3(CON2H4)2][Sr(dmf)2(CON2H4)2][H2V10O28]} (1) was obtained where cluster linkage is achieved through urea-bridged strontium dimers. In the absence of urea, a purely strontium-linked supramolecular architecture, {[Sr(dmf)4]2[H2V10O28]} (2), is formed. The chain architectures were characterized by single crystal X-ray diffraction, elemental analysis, UV-Vis and FT-IR spectroscopy. In order to learn about the assembly and dis-assembly of 1D architectures ESI-mass-spectrometry was performed. The results show how simple organic ligands may be used to engineer the crystal lattice and illustrate that further work is needed to understand the exact mode of action of the urea ligands. PMID:25622560
Estimation of future groundwater recharge using climatic analogues and Hydrus-1D
Directory of Open Access Journals (Sweden)
B. Leterme
2012-01-01
Full Text Available The impact of climate change on groundwater recharge is simulated using climatic analogue stations, i.e. stations presently under climatic conditions corresponding to a given climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimating groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richard's based soil water balance model Hydrus-1D and meteorological time series from analogue stations. Water balance calculations showed that transition from a temperate oceanic to a warmer subtropical climate without rainfall seasonality is expected to yield a decrease in groundwater recharge (?12% for the chosen representative analogue station of Gijon, Northern Spain. Based on a time series of 24 yr of daily climate data, the long-term average annual recharge decreased from 314 to 276 mm, although total rainfall was higher (947 mm in the warmer climate compared to the current temperate climate (899 mm. This is due to a higher soil evaporation (233 mm versus 206 mm and higher plant transpiration (350 versus 285 mm under the warmer climate.
Border collision bifurcation curves and their classification in a family of 1D discontinuous maps
International Nuclear Information System (INIS)
Highlights: ? We analyze a family of 1D piecewise linear discontinuous map in canonical form. ? BCB curves are analytically obtained. ? We identify period adding and period increment schemes. - Abstract: In this paper we consider a one-dimensional piecewise linear discontinuous map in canonical form, which may be used in several physical and engineering applications as well as to model some simple financial markets. We classify three different kinds of possible dynamic behaviors associated with the stable cycles. One regime (i) is the same existing in the continuous case and it is characterized by periodicity regions following the period increment by 1 rule. The second one (ii) is the regime characterized by periodicity regions of period increment higher than 1 (we shall see examples with 2 and 3), and by bistability. The third one (iii) is characterized by infinitely many periodicity regions of stable cycles, which follow the period adding structure, and multistability cannot exist. The analytical equations of the border collision bifurcation curves bounding the regions of existence of stable cycles are determined by using a new approach.
Non-supersymmetric D1/D5, F/NS5 and closed string tachyon condensation
International Nuclear Information System (INIS)
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' (BON) by continuously changing some parameters characterizing the solutions from one set of values to another. We show, by a time symmetric general bubble initial data analysis, that the final bubbles in these cases are static and stable and the interpolations can be physically interpreted as closed string tachyon condensation. As special cases, we recover the transition of two charge black F-string to BON, considered by Horowitz, and also the transition from AdS3 black hole to global AdS3.
Modeling Soil Salt and Nitrogen Transport under Different Fertigation Practices with Hydrus-1D
Directory of Open Access Journals (Sweden)
Zeng Wen-zhi
2013-05-01
Full Text Available 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 ammonium nitrogen while reducing the differences of their distributions in soil profile. In addition, when the initial urea application was in a small amount (10 g, the nitrate nitrogen concentration increased with soil depth while decreased with irrigation intensity after irrigation. Furthermore, both ammonium and nitrate nitrogen content of soil profile rose with increasing initial urea application amount, which played a more important role in the changes of soil ammonium (0~100 cm and nitrate (0~80 cm nitrogen content than irrigation intensity.
Preparation and luminescent properties of 1D Lu2O2S:Eu3+ nanorods
Wang, Guowei; Zou, Haifeng; Zhang, Bowen; Sun, Yidi; Huo, Qisheng; Xu, Xuechun; Zhou, Bing
2015-07-01
Highly crystalline and uniform Lu2O2S:Eu3+ nanorods have been successfully synthesized through a facile solvothermal method followed by a subsequent calcination process for the first time. X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and photoluminescence (PL) spectrum were utilized to characterize the samples. X-ray diffraction results demonstrate that all the diffraction peaks of the samples annealed at 600 °C can be well indexed to the pure hexagonal phase of Lu2O2S. From SEM and TEM it can be seen that Lu2O2S:Eu3+ nanorods are uniform rod-like nanostructures with a mean diameter of 22 nm and length of 500 nm. The effect of annealing temperature on the crystallinity and luminescent properties was investigated in detail. Furthermore, the obtained 1D Lu2O2S:Eu3+ nanorods exhibit strong red (Eu3+, 5D0 ? 7F2) luminescence under ultraviolet (UV) excitation.
1D Crossover, universality and finite-size scaling of the specific heat
Mooney, K. P.; Kimball, M. O.; Gasparini, F. M.
2009-02-01
We report measurements of the specific heat of 3He-4He mixtures near the superfluid transition when confined to channels of 1 /tm square cross section. These data test the universality of finite-size scaling as function of 3He concentration for 1D crossover. The analysis of these data requires that data measured at fixed concentration be converted to a specific heat at constant chemical potential difference phi = ?3 - ?4. This is carried out according to a procedure performed for planar mixtures by Kimball and Gasparini. We find that, in the most self-consistent analysis of the data, the mixtures define a separate scaling locus from that of pure 4He, both above and below T?. An analysis whereby the exponent a is forced to have the same universal value—as opposed to the best-fit value—yields a good collapse of all the data. This is achieved, however, at a cost of self-consistency. These results mirror very closely those obtained for finite-size scaling of confined planar mixtures, i.e. for 2D crossover.
1D Crossover, universality and finite-size scaling of the specific heat
International Nuclear Information System (INIS)
We report measurements of the specific heat of 3He-4He mixtures near the superfluid transition when confined to channels of 1 /tm square cross section. These data test the universality of finite-size scaling as function of 3He concentration for 1D crossover. The analysis of these data requires that data measured at fixed concentration be converted to a specific heat at constant chemical potential difference ? = ?3 - ?4. This is carried out according to a procedure performed for planar mixtures by Kimball and Gasparini. We find that, in the most self-consistent analysis of the data, the mixtures define a separate scaling locus from that of pure 4He, both above and below T?. An analysis whereby the exponent a is forced to have the same universal value-as opposed to the best-fit value-yields a good collapse of all the data. This is achieved, however, at a cost of self-consistency. These results mirror very closely those obtained for finite-size scaling of confined planar mixtures, i.e. for 2D crossover.
Disorder-induced phase transitions in a quasi 1-D Majorana wire
Rieder, Maria-Theresa; Brouwer, Piet W.; Adagideli, Inanc
2015-03-01
In a strictly 1D spinless p-wave superconductor, disorder is known to induce a phase transition between a topologically nontrivial phase and a trivial insulating phase when the mean free path l becomes of the order of the superconducting coherence length ?. We show that, in constrast, a multichannel spinless p-wave superconductor goes through a series of phase transitions alternating between topologically trivial and nontrivial phases upon increasing the disorder strength. The number of phase transitions equals the channel number N and each phase transition is accompanied by a Dyson singularity in the density of states ? (?) ~?-1| ln? | - 3 . The observed behavior is the result of an effective chiral symmetry allowing us to analytically investigate the phase boundaries and the density of states. The latter displays a power-law singularity ? (?) ~? | ? | - 1 for small energies ? away from the critical points. Using the concept of ``superuniversality,'' we relate the exponent ? to the wire's transport properties at zero energy and, hence, to the mean free path and the superconducting coherence length.
Room temperature hysteretic spin transition in 1D iron(II) coordination polymers
International Nuclear Information System (INIS)
The 1D spin transition compound [Fe(L1)3](ClO4)2 (1) with L1 ethyl-4H-1,2,4-triazol-4-yl-acetate, a novel neutral bidentate ligand, has been synthesised. The temperature dependence of the high-spin molar fraction derived from 57Fe Mossbauer spectroscopy reveals an exceptionally abrupt single step transition between low-spin and high-spin states with a hysteresis loop of width 5 K (Tcu = 298 K and Tc? = 293 K). This spin transition operating around room temperature presents striking reversible thermochromism from white at 295 K to pink at ice temperature, behaving as an optical alert towards temperature variations. This first order phase transition was additionally followed by differential scanning calorimetry in good agreement with Moessbauer spectroscopy data. The spin transition properties of a freshly prepared sample of 1, dried under a N2(g) stream which was formulated as [Fe(L1)3](ClO4)2·MeOH (2), are shifted below room temperature (T1/2u = 273 K and T1/2? 263 K), thus showing a remarkable influence of solvent inclusion on the spin state of these chain compounds.
A High-Throughput Enzyme-Coupled Assay for SAMHD1 dNTPase.
Seamon, Kyle J; Stivers, James T
2015-07-01
Sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1) is a recently discovered enzyme that plays a central role in nucleotide metabolism and innate immunity. SAMHD1 has deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase activity that depletes the dNTP substrates required for DNA synthesis in cells. The involvement of SAMHD1 in biological processes as varied as viral restriction, endogenous retroelement control, cancer, and modulation of anticancer/antiviral nucleoside drug efficacy makes it a valuable target for the development of small-molecule inhibitors. We report a high-throughput colorimetric assay for SAMHD1 dNTP hydrolase activity that takes advantage of Escherichia coli inorganic pyrophosphatase to convert PPPi to 3 Pi. The assay was validated by screening a library of 2653 clinically used compounds. Fifteen primary hits were obtained (0.57% hit rate); 80% of these were confirmed in a direct secondary assay for dNTP hydrolysis. The zinc salt of the antibiotic cephalosporin C was a potent inhibitor of SAMHD1 with an IC50 of 1.1 ± 0.1 µM, and this inhibition was largely attributable to the presence of zinc. The assay also screened a targeted library of nucleosides and their analogs, revealing that the antiviral drug acycloguanosine (acyclovir) is an inhibitor possessing excellent properties for future fragment-based drug development efforts. PMID:25755265
Application of HYDRUS 1D model for assessment of phenol-soil adsorption dynamics.
Pal, Supriya; Mukherjee, Somnath; Ghosh, Sudipta
2014-04-01
Laboratory-scale batch, vertical, and horizontal column experiments were conducted to investigate the attenuative capacity of a fine-grained clayey soil of local origin in the surrounding of a steel plant wastewater discharge site in West Bengal, India, for removal of phenol. Linear, Langmuir, and Freundlich isotherm plots from batch experimental data revealed that Freundlich isotherm model was reasonably fitted (R (2) = 0.94). The breakthrough column experiments were also carried out with different soil bed heights (5, 10, and 15 cm) under uniform flow to study the hydraulic movements of phenol by evaluating time concentration flow behavior using bromide as a tracer. The horizontal migration test was also conducted in the laboratory using adsorptive phenol and nonreactive bromide tracer to explore the movement of solute in a horizontal distance. The hydrodynamic dispersion coefficients (D) in the vertical and horizontal directions in the soil were estimated using nonlinear least-square parameter optimization method in CXTFIT model. In addition, the equilibrium convection dispersion model in HYDRUS 1D was also examined to simulate the fate and transport of phenol in vertical and horizontal directions using Freundlich isotherm constants and estimated hydrodynamic parameters as input in the model. The model efficacy and validation were examined through statistical parameters such as the coefficient of determination (R (2)), root mean square error and design of index (d). PMID:24407784
Steady-state propagation speed of rupture fronts along 1D frictional interfaces
Amundsen, David Skålid; Thøgersen, Kjetil; Katzav, Eytan; Malthe-Sørenssen, Anders; Scheibert, Julien
2015-01-01
The rupture of dry frictional interfaces occurs through the propagation of fronts breaking the contacts at the interface. Recent experiments have shown that the velocities of these rupture fronts range from quasi-static velocities proportional to the external loading rate to velocities larger than the shear wave speed. The way system parameters influence front speed is still poorly understood. Here we study steady-state rupture propagation in a 1D spring-block model of an extended frictional interface, for various friction laws. With the classical Amontons--Coulomb friction law, we derive a closed-form expression for the steady-state rupture velocity as a function of the interfacial shear stress just prior to rupture. We then consider an additional shear stiffness of the interface and show that the softer the interface, the slower the rupture fronts. We provide an approximate closed form expression for this effect. We finally show that adding a bulk viscosity on the relative motion of blocks accelerates stead...
Dynamic and steady state 1-D model of mediated electron transfer in a porous enzymatic electrode.
Do, T Q N; Varni?i?, M; Flassig, R J; Vidakovi?-Koch, T; Sundmacher, K
2015-12-01
A 1-D mathematical model of a porous enzymatic electrode exhibiting the mediated electron transfer (MET) mechanism has been developed. As a model system, glucose oxidation catalyzed by immobilized glucose oxidase (GOx) in the presence of a co-immobilized tetrathiafulvalene (TTF) mediator in the porous electrode matrix has been selected. The balance equations for potential fields in the electron- and ion-conducting phases as well as concentration field have been formulated, solved numerically and validated experimentally under steady state conditions. The relevant kinetic parameters of the lumped reaction kinetics have been obtained by global optimization. The confidence intervals (CIs) of each parameter have been extracted from the respective likelihood. The parameter study has shown that the parameters related to mediator consumption/regeneration steps can be responsible for the shift of the reaction onset potential. Additionally, the model has shown that diffusion of the oxidized mediator out of the catalyst layer (CL) plays a significant role only at more positive potentials and low glucose concentrations. Only concentration profiles in different layers influence the electrode performance while other state fields like potential distributions in different phases have no impact on the performance. The concentration profiles reveal that all electrodes work through; the observed limiting currents are diffusion-reaction limiting. The normalized electrode activity decreases with an increase of enzyme loading. According to the model, the reason for this observation is glucose depletion along the CL at higher enzyme loadings. Comparison with experiments advices a decrease of enzyme utilization at higher enzyme loadings. PMID:26257008
Label-free optical detection of bacteria on a 1-D photonic crystal of porous silicon
Wu, Chia-Chen; Alvarez, Sara D.; Rang, Camilla U.; Chao, Lin; Sailor, Michael J.
2009-02-01
The construction of a specific, label-free, bacteria biosensor using porous silicon 1-D photonic crystals will be described. Bacteria resident on the surface of porous silicon act as scattering centers for light resonant with the photonic crystal; the diffusely scattered light possesses the optical spectrum of the underlying photonic crystal. Using a spectrometer fitted to a light microscope, the bacteria are imaged without using exogenous dyes or labels and are quantified by measuring the intensity of scattered light. In order to selectively bind and identify bacteria using porous Si, we use surface modifications to reduce nonspecific binding to the surface and to engineer bacteria specificity onto the surface. Bovine serum albumin (BSA) was adsorbed to the porous Si surface to reduce nonspecific binding of bacteria. The coatings were then chemically activated to immobilize polyclonal antibodies specific to Escherichia coli. Two E. coli strains were used in our study, E. coli DH5? and non-pathogenic enterohemorrhagic Escherichia coli (EHEC) strain. The nonpathogenic Vibrio cholerae O1 strain was used to test for antibody specificity. Successful attachment of antibodies was measured using fluorescence microscopy and the scattering method was used to test for bacteria binding specificity.
International Nuclear Information System (INIS)
The authors applied 1D homonuclear Hartmann-Hahn (1D-HOHAHA) and difference NOE experiments to determine the chemical structure of Forssman's antigen, a glycolipid purified from sheep red blood cells. The subspectra corresponding to the individual sugar components were extracted from overlapping proton resonances by selective excitation of the anomeric proton resonances, so that unambiguous assignments of the sugar proton resonances were accomplished. Then, difference NOE experiments were performed to determine the linkage of the sugar units. The present procedure was found to be useful for the structure determination of glycoconjugates and also reduces the amount of samples and machine time. 8 refs.; 3 figs
Dash, Satya; Sano, Hiroyuki; Rochford, Justin J; Semple, Robert K.; Yeo, Giles; Hyden, Caroline S. S.; Soos, Maria A.; Clark, James; Rodin, Andrew; Langenberg, Claudia; Druet, Celine; Fawcett, Katherine A.; Tung, Y C Loraine; Wareham, Nicolas J.; Barroso, Inês
2009-01-01
Tre-2, BUB2, CDC16, 1 domain family member 4 (TBC1D4) (AS160) is a Rab-GTPase activating protein implicated in insulin-stimulated glucose transporter 4 (GLUT4) translocation in adipocytes and myotubes. To determine whether loss-of-function mutations in TBC1D4 might impair GLUT4 translocation and cause insulin resistance in humans, we screened the coding regions of this gene in 156 severely insulin-resistant patients. A female presenting at age 11 years with acanthosis nigricans and extreme po...
Tonks-Girardeau and Super Tonks-Girardeau States of a Trapped 1D Spinor Bose Gas
Girardeau, M. D.
2010-01-01
A harmonically trapped ultracold 1D spin-1 Bose gas with strongly repulsive or attractive 1D even-wave interactions induced by a 3D Feshbach resonance is studied. The exact ground state, a hybrid of Tonks-Girardeau (TG) and ideal Fermi gases, is constructed in the TG limit of infinite even-wave repulsion by a spinor Fermi-Bose mapping to a spinless ideal Fermi gas. It is then shown that in the limit of infinite even-wave attraction this same state remains an exact many-body ...
DEFF Research Database (Denmark)
Breinbjerg, Olav; Yaghjian, Arthur D.
2014-01-01
For an infinite 1D periodic structure with unit cells consisting of two planar slabs of magnetodielectric materials, the electric field – as well as magnetic field, electric flux density, magnetic flux density, polarization, and magnetization – can be expressed as infinite series of Floquet-Bloch space harmonics. We discuss how space harmonic permittivity and permeability can be expressed in seemingly different though equivalent forms, and we investigate these parameters of the zeroeth order space harmonic for a particular 1D periodic structure that is based on a previously reported 3D periodic structure with unit cells containing a magneto-dielectric sphere.
DEFF Research Database (Denmark)
Jensen, Jakob SØndergaard
2010-01-01
Results are presented for optimal layout of materials in the spatial and temporal domains for a 1D structure subjected to transient wave propagation. A general optimization procedure is outlined including derivation of design sensitivities for the case when the mass density and stiffness vary in time. The outlined optimization procedure is exemplified on a 1D wave propagation problem in which a single gaussian pulse is compressed when propagating through the optimized structure. Special emphasis is put on the use of a time-discontinuous Galerkin integration scheme that facilitates analysis of a system with a time-varying mass matrix.
Bagnara, Davide; Ibatici, Adalberto; Corselli, Mirko; Sessarego, Nadia; Tenca, Claudya; De Santanna, Amleto; Mazzarello, Andrea; Daga, Antonio; Corvò, Renzo; De Rossi, Giulio; Frassoni, Francesco; Ciccone, Ermanno; Fais, Franco
2009-01-01
Therapy of tumors by injection of T cells is gaining attention, although technical problems remain. This pre-clinical study investigates the potential of NKT cells, readily expanded in vitro and having a relatively wide specificity, determined by target expression of CD1d. This is attractive for lymphoid tumors and the data show attack on a xenograft in vivo in the presence of the CD1d-binding alpha-galactosylceramide. While clinical application is not immediate, the model allows useful disse...
Comparison of 1D and 2D CSR Models with Application to the FERMI(at)ELETTRA Bunch Compressors
International Nuclear Information System (INIS)
We compare our 2D mean field (Vlasov-Maxwell) treatment of coherent synchrotron radiation (CSR) effects with 1D approximations of the CSR force which are commonly implemented in CSR codes. In our model we track particles in 4D phase space and calculate 2D forces (1). The major cost in our calculation is the computation of the 2D force. To speed up the computation and improve 1D models we also investigate approximations to our exact 2D force. As an application, we present numerical results for the Fermi(at)Elettra first bunch compressor with the configuration described in (1).
Comparison of 1D and 2D CSR Models with Application to the FERMI@ELETTRA Bunch Compressors
Energy Technology Data Exchange (ETDEWEB)
Bassi, G.; Ellison, J.A.; Heinemann, K.
2011-03-28
We compare our 2D mean field (Vlasov-Maxwell) treatment of coherent synchrotron radiation (CSR) effects with 1D approximations of the CSR force which are commonly implemented in CSR codes. In our model we track particles in 4D phase space and calculate 2D forces [1]. The major cost in our calculation is the computation of the 2D force. To speed up the computation and improve 1D models we also investigate approximations to our exact 2D force. As an application, we present numerical results for the Fermi{at}Elettra first bunch compressor with the configuration described in [1].
Liu, L.; Sletten, R. S.; Hallet, B.; Waddington, E. D.; Wood, S. E.
2013-12-01
An ancient massive ice body buried under several decimeters of debris in Beacon Valley, Antarctica is believed to be over one million years old, making it older than any known glacier or ice cap. It is fundamentally important as a reservoir of water, proxy for climatic information, and an expression of the periglacial landscape. It is also one of Earth's closest analog for widespread, near-surface ice found in Martian soils and ice-cored landforms. We are interested in understanding controls on how long this ice may persist since our physical model of sublimation suggests it should not be stable. In these models, the soil temperatures and the gradient are important because it determines the direction and magnitude of the vapor flux, and thus sublimation rates. To better understand the heat transfer processes and constrain the rates of processes governing ground ice stability, a model of the thermal behavior of the permafrost is applied to Beacon Valley, Antarctica. It calculates soil temperatures based on a 1-D thermal diffusion equation using a fully implicit finite volume method (FVM). This model is constrained by soil physical properties and boundary conditions of in-situ ground surface temperature measurements (with an average of -23.6oC, a maximum of 20.5oC and a minimum of -54.3oC) and ice-core temperature record at ~30 m. Model results are compared to in-situ temperature measurements at depths of 0.10 m, 0.20 m, 0.30 m, and 0.45 m to assess the model's ability to reproduce the temperature profile for given thermal properties of the debris cover and ice. The model's sensitivity to the thermal diffusivity of the permafrost and the overlaying debris is also examined. Furthermore, we incorporate the role of ice condensation/sublimation which is calculated using our vapor diffusion model in the 1-D thermal diffusion model to assess potential latent heat effects that in turn affect ground ice sublimation rates. In general, the model simulates the ground thermal regime well. Detailed temperature comparison suggests that the 1-D thermal diffusion model results closely approximate the measured temperature at all depths with the average square root of the mean squared error (SRMSE) of 0.15oC; a linear correlation between modeled and measured temperatures yields an average R2 value of 0.9997. Prominent seasonal temperature variations diminish with depth, and it equilibrates to mean annual temperature at about 21.5 m depth. The amount of heat generated/consumed by ice condensation/sublimation is insufficient to significantly impact the thermal regime.
Fast Generation of Sparse Random Kernel Graphs
2015-01-01
The development of kernel-based inhomogeneous random graphs has provided models that are flexible enough to capture many observed characteristics of real networks, and that are also mathematically tractable. We specify a class of inhomogeneous random graph models, called random kernel graphs, that produces sparse graphs with tunable graph properties, and we develop an efficient generation algorithm to sample random instances from this model. As real-world networks are usually large, it is essential that the run-time of generation algorithms scales better than quadratically in the number of vertices n. We show that for many practical kernels our algorithm runs in time at most 𝒪(n(logn)2). As a practical example we show how to generate samples of power-law degree distribution graphs with tunable assortativity. PMID:26356296
Anderson, E. J.; Phanikumar, M. S.
2010-12-01
In recent years there is an increased interest in solute transport processes in large rivers given their role in delivering nutrients, bacteria and sediment to coastal regions (e.g., rivers in the US Midwest contributing to the Gulf of Mexico hypoxia). While small to medium rivers received a lot of attention in the past few decades, especially from the point of hyporheic exchange and nutrient uptake, relatively few studies have focused on solute transport in large rivers, especially on the dynamics of surface storage zones. Here we report the results of a large-scale tracer study on the St. Clair River, a large international river (discharge ~ 5000 cms) straddling the border between the U.S and Canada that serves as the outflow for Lake Huron. We first describe a fully three-dimensional hydrodynamic model and a 3D particle transport model of the St. Clair River based on FVCOM (Finite Volume Coastal Ocean Model). We then use the 3D particle transport model to generate breakthrough data for evaluating the surface storage dynamics in the river using several classes of one-dimensional solute transport models. In particular, we evaluate the ability of the 1D models to describe both the magnitude and the timing of the peaks. The one-dimensional models examined include multi-rate transient storage (MRTS) models in which the storage zones are arranged either in series or in parallel as well as models based on time and space fractional derivatives. Results indicate that for the 1D models to describe data adequately, the timing of solute pulses which corresponds to various in-channel features such as sand bars or islands should be taken into account.
Scientific Electronic Library Online (English)
Claudia Carolina, Sánchez Parra; Mauricio, Rojas López; Lina M, Yassin; Gloria María, Vásquez Duque.
2013-12-01
Full Text Available Resumen Introducción: Los linfocitos B (LB) se consideran el centro de la desregulación inmune en pacientes con lupus eritematoso sistémico (LES), principalmente, por su producción de autoanticuerpos. Recientemente, se demostró la existencia de LB, incluidos en los B transicionales, con capacidad re [...] guladora (Breg) y fenotipo CD19+CD24hiCD38hi. En humanos se demostró la importancia de CD80 y CD86 en su función reguladora. El papel de CD1d aún no ha sido evaluado. Objetivo: Evaluar la frecuencia de LB maduros, memoria y transicionales, en controles y pacientes con LES, además de la expresión de CD1d y correlacionarla con la actividad de la enfermedad medida por SLEDAI (Systemic Lupus Erythematosus Disease Activity Index). Materiales y métodos: Se evaluó por citometría de flujo la frecuencia de subpoblaciones de LB basados en la expresión de CD19, CD24 y CD38, además de CD1d, en controles con otras enfermedades autoinmunes (OEA), individuos sanos y pacientes con LES, y se correlacionó con SLEDAI. Resultados: Se evidenció una disminución significativa en el porcentaje de LB de memoria en pacientes LES y OEA, sin alteraciones en las subpoblaciones de LB maduros y transicionales. La expresión de CD1d no evidenció diferencias significativas en ninguna de las subpoblaciones ni se correlacionó con SLEDAI. Conclusión: La disminución de la subpoblación de memoria fue previamente descrita en LES y se ha asociado a algunos tipos de tratamiento. Aunque CD1d se ha asociado a la función de Breg en murinos, no hubo diferencias significativas en su expresión en las subpoblaciones y queda por clarificar su papel en la función de las Breg humanas. Abstract in english Abstract Introduction: B lymphocytes are considered the center of immune dysregulation in Systemic Lupus Erythematosus (SLE). It has recently been demonstrated that there is a B cell with regulatory capacities (Breg) included in transitional B lymphocytes with the phenotype CD19+CD24hiCD38hi. The im [...] portance of CD80 and CD86 in the regulatory function of the Bregs has been demonstrated in humans, but the role of CD1d has not been evaluated. Objective: To evaluate the frequency of mature, memory and transitional B cells in SLE patients and controls, the expression of CD1d among these cells, and its correlation with the activity of the disease measured using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Materials and methods: The frequency of the B cell subsets was evaluated by flow cytometry based on the expression of CD19, CD24 and CD38, as well as CD1d in these cells in SLE patients and controls, and were correlated with the activity of the disease measured using the SLEDAI. Results: A significant reduction in the percentage of memory B cells was observed in SLE patients and other autoimmune conditions, with no changes in the mature or transitional B cell subsets. Similarly, no significant differences were observed in the expression of CD1d in any of the subsets, nor was there any correlation with the SLEDAI. Conclusion: The reduction of the memory subset has been previously described in SLE, and has been associated with some types of treatment. The expression of CD1d in all the subsets was observed, but its role in the regulatory function of the CD19+CD24hiCD38hi cells is still not clear.
Pauwels, P J; Palmier, C; Wurch, T; Colpaert, F C
1996-01-01
This study was undertaken to investigate the pharmacology of human serotonin (5-HT)1D receptor sites by measuring two functional cellular responses, inhibition of forskolin-stimulated cAMP formation and promotion of cell growth, using transfected rat C6-glial cell lines and a broad series of 5-HT receptor agonists. Stable and separate transfection of a pcDNA3 or pRcRSV plasmid, each containing a cloned human 5-HT1D receptor gene, in rat C6-glial cells was confirmed with RT-PCR of 5-HT1D receptor mRNA and radioligand binding with [3H] 5-carboxamidotryptamine (5-CT) and [3H] sumatriptan. The 5-HT1D receptor density was 350 and 1050 fmol/mg protein for the C6-glial/pcDNA3/5-HT1D and C6-glial/pRcRSV/5-HT1D cell line, and forskolin (100 microM)-induced cAMP formation was inhibited by 45 and 78% in the presence of 1 microM 5-HT, respectively. A comparison of the intrinsic agonist activities for sixteen 5-HT receptor ligands with their corresponding binding affinities for the human 5-HT1D receptor site showed similar results for both cell lines with the exception of the partial agonist m-trifluoro-phenyl-piperazine (TFMPP). Three classes of compounds were observed: 1) efficacious agonists, such as 5-CT, 5-methoxytryptamine, 5-HT, sumatriptan, bufotenine, 5-methoxy-3(1,2,3,6-tetrahydro-4-pyridinyl)1H-indole (RU 24,969), tryptamine and 8-hydroxy-2(di-n-propilamino)tetralin (8-OH-DPAT), with agonist potency close to their binding affinity; 2) the partial agonists metergoline, 7-trifluoromethyl-4(4-methyl-1-piperazinyl)-pyrolo-(1,2-a) quinoxaline (CGS 12066B), 1-naphthylpiperazine and 2'-methyl-4-(5-methyl-[1,2,4]oxadiazol-3-yl)-biphenyl-4-carboxylic acid [4-methoxy-3-(4-methylpiperazin-1-yl)-phenyl]-amide (GR 127,935) with marked intrinsic agonist activity but at concentrations higher than their binding affinity; and 3) the silent antagonists ritanserin, ketanserin and methiothepin, apparently free of intrinsic agonist activity, with antagonist potency close to their binding affinity. The cAMP data were further supported by the observed promotion of cell growth by stimulation of both transfected cell lines with sumatriptan under serum-free conditions; half-maximal stimulation was obtained at 4.4 nM (C6-glial/pcDNA3/5-HT1D) fully in agreement with its EC50-value (5.7 nM) for inhibition of cAMP formation. This growth promoting effect was antagonised by 1 microM methiothepin and not observed in pcDNA3-plasmid-transfected and non-transfected C6-glial cells. A comparative study with a C6-glial/pcDNA3/5-HT1B cell line expressing a similar amount of cloned human 5-HT1B receptors (Bmax: 360 fmol/mg protein) showed almost no intrinsic agonist activity for metergoline, 1-naphtylpiperazine and GR 127,935. Together with the 5-HT1D receptor binding selectivity and antagonist activity of ketanserin and ritanserin, the findings define important pharmacological differences between cloned human 5-HT1D and 5-HT1B receptor sites. PMID:8717154
A first report on meteor-generated seismic signals as detected by the SANSN
Scientific Electronic Library Online (English)
Frederick, Roelofse; Ian, Saunders.
Full Text Available A bright meteor with an apparent magnitude of -18 was seen over large parts of southern Africa at ~23:00 South African Standard Time on 21 November 2009. Here we discuss the eye-witness accounts related to the meteor as well as the seismic signals generated by the meteor's passage through the atmosp [...] here as detected by the Mussina seismograph station forming part of the South African National Seismograph Network. Two signals were identified on the seismogram; the first arrival is interpreted as a precursor coupled seismic wave and the second, which arrived ~138 s after the first, as a directly coupled airwave. The meteor is thought to have entered the atmosphere close to Mussina shortly before 22:55.06 local time, from where it proceeded in a westerly to northwesterly direction with an elevation angle not exceeding 43°. Our results presented here dispel the beliefs of many observers who thought that the meteor must have made landfall very close to their localities. In addition, this contribution documents the first instance of meteor-related seismic signals recorded by the South African National Seismograph Network.
A 1-D radiative conductive model to study the SOIR/VEx thermal profiles
Mahieux, Arnaud; Erwin, Justin T.; Chamberlain, Sarah; Robert, Séverine; Carine Vandaele, Ann; Wilquet, Valérie; Thomas, Ian; Yelle, Roger V.; Bertaux, Jean-Loup
2015-04-01
SOIR is an infrared spectrometer on board Venus Express that probes the Venus terminator region since 2006. The measurements are taken on the morning and evening sides of the terminator, covering all latitudes from the North Pole to the South Pole. Its wavelength range - 2.2 to 4.3 ?m - allows a detailed chemical inventory of the Venus atmosphere [1-5], such as CO2, CO, H2O, HCl, HF, SO2 and aerosols. CO2 is detected from 70 km up to 165 km, CO from 70 km to 140 km, and the minor species typically below 110 km down to 70 km. Number density profiles of these species are computed from the measured spectra. Temperature profiles are obtained while computing the spectral inversion of the CO2 spectra combined with the hydrostatic law [6]. These temperature measurements show a striking permanent temperature minimum (at 125 km) and a weaker temperature maximum (over 100-115 km). The time variability of the CO2 density profiles spans over two orders of magnitude, and a clear trend is seen with latitude. The temperature variations are also important, of the order of 35 K for a given pressure level, but the latitude variation are small. Miss-RT, a 1D radiative transfer model has been developed to reproduce the SOIR terminator profiles, derived from the Mars thermosphere code presented in [7]. This model has been expanded to better account for the CO2, CO, and O non-LTE radiative heating and cooling processes which have to be considered in the dense atmosphere of Venus. Radiative cooling by minor species detected by SOIR (e.g. HCl, SO2, and H2O) are found to be small in comparison to the 15 ?m CO2 cooling. Aerosol cooling in the 60-90km altitude range may be important to the thermal balance. There is a good agreement between the 1D model temperature profile and the mean SOIR temperature profile. Further we can suggest parameters that can be adjusted to improve the agreement between the model and measurements. The remaining differences can be attributed to the atmosphere dynamics at the terminator. 1. Bertaux, J.L., et al., A warm layer in Venus' cryosphere and high altitude measurements of HF, HCl, H2O and HDO. Nature, 2007. 450(29 November): p. 646-649, doi:10.1038/nature05974. 2. Vandaele, A.C., et al., Carbon monoxide short term variability observed on Venus with SOIR/VEX. Planet. Space Sci., 2014. (in press). 3. Mahieux, A., et al., Venus mesospheric sulfur dioxide measurement retrieved from SOIR on board Venus Express. Planet. Space Sci., 2014. (in press). 4. Mahieux, A., et al., Hydrogen Halides measurements in the Venus upper atmosphere retrieved from SOIR on board Venus Express. Planet. Space Sci., 2014. (in press). 5. Wilquet, V., et al., Optical extinction due to aerosols in the upper haze of Venus: Four years of SOIR/VEX observations from 2006 to 2010. Icarus, 2012. 217(2): p. 875-881. 6. Mahieux, A., et al., Update of the Venus density and temperature profiles at high altitude measured by SOIR on board Venus Express. Planet. Space Sci., 2014. (submitted). 7. Yelle, R., et al., Perturbation of the Mars Atmosphere by the Near-Collision with Comet C/2013 A1 (Siding Spring). Icarus, 2014. 237: p. 202-210.
Spin transport through a 1D Mott-Hubbard insulator of finite length
Ponomarenko, V. V.
2014-01-01
We study low-energy spin and charge transport through a 1D Mott-Hubbard insulator of finite length L attached to Fermi liquid reservoirs, which, in the presence of spin accumulation, are characterized by different electrochemical potentials for electrons of opposite spin polarizations. At temperatures less than T_L \\equiv v_c/L (vc: charge velocity in the wire) and under the assumption that the Hubbard gap 2M is large enough, M > TL, we calculate the average currents (charge and spin) and their zero-frequency correlators. The average spin (charge) current depends only on the difference (sum) of the spin-dependent voltages 2V_s\\ (2V_c) and even a weak electron backscattering of low rate \\Gamma_s \\ll T_L leads to the spin current suppression at |V_s| smaller than \\Gamma=\\text{const}\\times \\sqrt{T_L M}\\exp\\{-2M/T_L\\}+\\Gamma_s . The spin current recovers its free mode behavior at spin voltage or temperature larger than ?. Suppression of the spin-charge correlator suggesting the appearance of spin-charge separation needs both |V_{s,c}| to be larger than ?. In the absence of the average charge current at V_c=0 its shot noise is proportional to the average spin backscattered current defined by Vs and can be used to measure the spin accumulation in the reservoirs. The relation of these results to Kondo dot transport in the Toulouse limit is also clarified.
Box model and 1D longitudinal model of flow and transport in Bosten Lake, China
Li, Ning; Kinzelbach, Wolfgang; Li, WenPeng; Dong, XinGuang
2015-05-01
Bosten Lake in the southeast of Yanqi Catchment, China, supports the downstream agricultural and natural environments. Over the last few decades the intensive agricultural activities in Yanqi Catchment resulted in decreased lake levels and deteriorated lake water quality. A two-box model is constructed to understand the evolution of lake level and salinity between 1958 and 2008. The two-box model of the lake indicates that the evaporation does have the same trend as the observed lake area and the annual average evaporation agrees with the value obtained from the Penman-Monteith approach. To achieve a correct salt balance, the ratio of outflow concentration and average lake concentration has to be around 0.7. This is due to the incomplete mixing of the lake caused by short-circuiting between tributary inflow and the main outflow via the pump stations abstracting water from the lake. This short-circuiting is investigated in more detail by a 1D numerical flow and transport model of the lake calibrated with observations of lake level and lake concentrations. The distributed model reproduces the correct time-varying outflow concentration. It is used for the assessment of two basic management options: increasing river discharge (by water saving irrigation, reduction of phreatic evaporation or reduction of agricultural area) and diverting saline drainage water to the desert. Increasing river discharge to the lake by 20% reduces the east basin salt concentration by 0.55 kg/m3, while capturing all the drainage water and discharging it to depressions instead of the lake reduces the east basin salt concentration by 0.63 kg/m3. A combination of increasing river inflow and decreasing drainage salt flux is sufficient to bring future lake TDS below the required 1 kg/m3, to keep a lake level that sustains the lake ecosystem, and to supply more water for downstream development and ecosystem rehabilitation.
Finite element modeling and experimental characterization of crosstalk in 1-D CMUT arrays.
Bayram, Baris; Kupnik, Mario; Yaralioglu, Goksen G; Oralkan, Omer; Ergun, Arif Sanli; Lin, Der-Song; Wong, Serena H; Khuri-Yakub, Butrus T
2007-02-01
Crosstalk is the coupling of energy between the elements of an ultrasonic transducer array. This coupling degrades the performance of transducers in applications such as medical imaging and therapeutics. In this paper, we present an experimental demonstration of guided interface waves in capacitive micromachined ultrasonic transducers (CMUTs). We compare the experimental results to finite element calculations using a commercial package (LS-DYNA) for a 1-D CMUT array operating in the conventional and collapsed modes. An element in the middle of the array was excited with a unipolar voltage pulse, and the displacements were measured using a laser interferometer along the center line of the array elements immersed in soybean oil. We repeated the measurements for an identical CMUT array covered with a 4.5-microm polydimethylsiloxane (PDMS) layer. The main crosstalk mechanism is the dispersive guided modes propagating in the fluid-solid interface. Although the transmitter element had a center frequency of 5.8 MHz with a 130% fractional bandwidth in the conventional operation, the dispersive guided mode was observed with the maximum amplitude at a frequency of 2.1 MHz, and had a cut-off frequency of 4 MHz. In the collapsed operation, the dispersive guided mode was observed with the maximum amplitude at a frequency of 4.0 MHz, and had a cut-off frequency of 10 MHz. Crosstalk level was lower in the collapsed operation (-39 dB) than in the conventional operation (-24.4 dB). The coverage of the PDMS did not significantly affect the crosstalk level, but reduced the phase velocity for both operation modes. Lamb wave modes, A0 and S0, were also observed with crosstalk levels of -40 dB and -65 dB, respectively. We observed excellent agreement between the finite element and the experimental results. PMID:17328339