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.
Stacking Global Seismograms Revisited
Shearer, P. M.; Buehler, J. S.; Denolle, M.; Fan, W.; Ma, Z.; Mancinelli, N. J.; Matoza, R. S.; Wang, W.; Wang, Y.; Zhan, Z.
2014-12-01
Over 20 years ago, stacks of global seismograms produced direct images of the global seismic wavefield highlighting the visibility, frequency content, and polarity of known seismic phases, and also identified a host of new phases associated with reflections and phase conversions from upper-mantle discontinuities. Two different stacking methods proved particularly useful: (1) STA/LTA-filtered stacks that describe the local signal-to-noise characteristics of the major seismic phases. These serve to image the entire wavefield in a uniform way for educational purposes and to show which phases are observed most clearly as a guide to future research. These stacks also resolve SH versus SV timing differences consistent with radial anisotropy. (2) Reference-phase stacks that preserve the polarity, amplitude, and timing of traces with respect to a specified target phase. These show a large number of top-side and bottom-side reflections and phase conversions from the 410- and 660-km discontinuities that create weak phases with a characteristic "railroad track" appearance both preceding and following many of the main seismic phases. Reference-phase stacking can also be used to produce coherent surface-wave stacks at very long periods, which directly show the dispersive character of the surface waves. Here we revisit and update these stacks by exploiting the vastly increased data now available from the IRIS DMC to produce greatly improved wavefield images. We present several examples of the different stacking approaches and point out their various features, including promising targets for future research.
1D Hybrid Simulations of Ion Cyclotron Waves Generation by Mass Loading at Io
Cowee, M. M.; Russell, C. T.; Strangeway, R. J.
2007-05-01
Ion cyclotron waves were detected by the Galileo spacecraft as it flew by the Jovian moon, Io, in 1995-2002. These waves are generated by populations of newborn sulfur monoxide and sulfur dioxide ions mass loaded from Io's atmosphere. Because the wave amplitudes are proportional to the number of ions generating them, the observed waves can be used to estimate the mass loading rate at Io. Using a 1D hybrid technique (kinetic ions, fluid electrons), we simulate the addition of newborn molecular sulfur ions to an Io torus-like plasma and examine the generated waves. The generated waves are narrowly peaked just below the newborn ion gyrofrequency and show little change over time for a uniform mass loading rate. Typically, the newborn ions lose ~30% of their initial energy as they scatter on the self-generated waves. Some of this energy is lost by transferring it other ion components in the plasma and some resides in the ion cyclotron waves. This disagrees with previous estimates of mass loading rates at Io assumed that the newborn ions would lose 50% of their initial energy to wave growth. Because the ions lose less energy than this, more ions are necessary in order to generate the observed wave amplitudes, so the previous mass loading rate estimates are too low.
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 www.instaseis.net .
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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.
A 1-D/2-D model for an exterior HVAC rectangular duct with a steady solar heat flux generation
Energy Technology Data Exchange (ETDEWEB)
Dehra, H. [American Institute Industry Forum on Energy, Montreal, PQ (Canada)
2006-07-01
A thermal analysis of an exterior Heating, Ventilation and Air-Conditioning (HVAC) rectangular duct commonly installed in building envelopes was presented. A 1-D/2-D model was proposed to analyze the duct, which was installed between a metallic exterior wall exposed to a steady heat flux generation from solar heat gain and a well-insulated back panel. A numerical grid was constructed with 2 adjoining stacks of slices of control volumes of surface and air nodes. An explicit matrix solution was used by constructing a U-matrix with conductive, convective, radiative, and heat transport conductances, and a heat source Q-matrix. Temperature predictions with initial boundary conditions of mass flow rate, solar intensity, sink and source temperatures were presented. Results indicated that the model was more accurate than traditional thermal models for cases where sections of conjugate heat exchange occur, as well as for situations where stack effects due to thermal buoyancy necessitate 2-D nodal analysis for distant composite nodes. A comparison between the proposed model and a traditional 1-D model was then conducted. It was concluded that the temperature solutions obtained from a traditional 1-D model for the given example over-predicted by an average value of 5, 13 and 22 per cent for the outer wall, inner wall and air respectively. 10 refs., 1 tab., 4 figs.
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.
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.
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.
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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
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.
Direct-seismogram inversion for receiver-side structure with uncertain source-time functions
Dettmer, Jan; Dosso, Stan E.; Bodin, Thomas; Stip?evi?, Josip; Cummins, Phil R.
2015-11-01
This paper presents direct-seismogram inversion (DSI) for receiver-side structure which treats the source signal incident from below (the effective source-time function-STF) as a vector of unknown parameters in a Bayesian framework. As a result, the DSI method developed here does not require deconvolution by observed seismogram components as typically applied in receiver-function inversion and avoids the problematic issue of choosing subjective tuning parameters in this deconvolution. This results in more meaningful inversion results and uncertainty estimation compared to classic receiver-function inversion. A rigorous derivation is presented of the likelihood function required for unbiased inversion results. The STF is efficiently inferred by a maximum-likelihood closed-form expression that does not require deconvolution by noisy waveforms. Rather, deconvolution is only by predicted impulse responses for the unknown environment (considered to be a 1-D, horizontally stratified medium). For a given realization of the parameter vector which describes the medium below the station, data predictions are computed as the convolution of the impulse response and the maximum-likelihood source estimate for that medium. Therefore, the assumption of a Gaussian pulse with specified parameters, typical for the prediction of receiver functions, is not required. Directly inverting seismogram components has important consequences for the noise on the data. Since the signal processing does not require filtering and deconvolution, data errors are less correlated and more straightforward to model than those for receiver functions. This results in better inversion results (parameter values and uncertainties), since assumptions made in the derivation of the likelihood function are more likely to be met by the inversion process. The DSI method is demonstrated for simulated waveforms and then applied to data for station Hyderabad on the Indian craton. The measured data are inverted with both the new DSI and traditional receiver-function inversion. All inversions are carried out for a trans-dimensional model that treats the number of layers in the model as unknown. Results for DSI are consistent with previous studies for the same location. The DSI has clear advantages in trans-dimensional inversion. Uncertainty estimates appear more realistic (larger) in both model complexity (number of layers) and in terms of seismic velocity profiles. Receiver-function inversion results in more complex profiles (highly-layered structure) and suggests unreasonably small uncertainties. This effect is likely also significant when the parametrization is considered to be fixed but exacerbated for the trans-dimensional model: If hierarchical errors are poorly estimated, trans-dimensional models overestimate the structure which produces unfavourable results for the receiver-function inversion.
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.
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.
Fast estimation of local magnitudes from non-standard Wood-Anderson, short period, seismograms
González, J J; J. Carlos; Acosta, J.(University of Mississippi, Oxford, U.S.A.); J. Frez; R. García-Arthur; F. A.Nava
2003-01-01
We propose a method for fast estimation of local magnitudes from seismograms (analog or digital) different from the standard Wood-Anderson ones. The method provides a justification of the widely used methods for approximate evaluation of magnitudes from analog seismograms. The method is illustrated through an application to local microseismic data from Baja California, Mexico.
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.
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.
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
Ray synthetic seismograms: a useful tool in the International Data Center environment
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P. Firbas
1994-06-01
Full Text Available In this paper some of the results of a feasibility study on ray synthetic seismograms usage are reported. A computational method, ways of composing synthetic traces, an application of the source wavelet and the radiation pattern and integration of such an approach into the Center for Seismic Studies (CSS revision 3.0 structure are outlined. Further on, results obtained for model examples, nuclear explosions, and earthquakes are presented. Conclusions of the undertaken feasibility study help to understand that ray synthetic seismograms represent a very fast tool (results in ?no time? and simultaneously represent a complex tool with all needed features. The ray synthetic seismograms can be implemented in various ways: to be computed automatically and used within the Intelligent Monitoring System, to be computed automatically and provided to the analyst, to provide a database of master events, to be computed interactively by an analyst during routine daily analysis.
Source mechanisms and near-source wave propagation from broadband seismograms
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J. Perrot
1994-06-01
Full Text Available Recording seismic events at teleseismic distances with broadband and high dynamic range instruments provides new high-quality data that allow us to interpret in more detail the complexity of seismic rupture as well as the heterogeneous structure of the medium surrounding the source where waves are initially propagating. Wave propagation analysis is performed by ray tracing in a local cartesian coordinate system near the source and in a global spherical coordinate system when waves enter the mantle. Seismograms are constructed at each station for a propagation in a 2.5-D medium. Many phases can be included and separately analyzed; this is one of the major advantages of ray tracing compared to other wave propagation techniques. We have studied four earthquakes, the 1988 Spitak Armenia Earthquake (Ms = 6.9, the 1990 Iran earthquake (Ms = 7.7, the 1990 romanian earthquake (Ms = 5.8 and the 1992 Erzincan, Turkey earthquake (Ms = 6.8. These earthquakes exhibit in different ways the complexity of the rupture and the signature of the medium surrounding the source. The use of velocity seismograms, the time derivative of displacement, increases the difficulty of the fit between synthetic seismograms and real seismograms but provides clear evidence for a need of careful time delay estimations of the different converted phases. We find that understanding of the seismic rupture as well as the influence of the medium surrounding the source for teleseismically recorded earthquakes requires a multi-stop procedure: starting with ground displacement seismograms, one is able to give a first description of the rupture as well as of the first-order influence of the medium. Then, considering the ground velocity seismograms makes the fit more difficult to obtain but increases our sensitivity to the rupture process and early converted phases. With increasing number of worldwide broadband stations, a complex rupture description is possible independently of field observations, which can be used to check the adequacy of such complicated models.
Class Room Exercises Using JMA-59-Type Seismograms for Earthquake Study at High-School Level
Okamoto, Y.; Furuta, S.; Hirota, N.
2013-12-01
The JMA-59-type electromagnetic seismograph was the standard seismograph for routine observations by the Japan Meteorological Agency (JMA) from the 1960's to the 1990's. Some features of those seismograms include 1) displacement wave records (electrically integrated from a velocity output by a moving-coil-type sensor), 2) ink records on paper (analog recording with time marks), 3) continuous drum recording for 12 h, and 4) lengthy operation time over several decades. However, the digital revolution in recording systems during the 1990's made these analog features obsolete, and their abundant and bulky paper-based records were stacked and sometimes disregarded in the library of every observatory. Interestingly, from an educational aspect, the disadvantages of these old-fashioned systems become highly advantageous for educational or outreach purposes. The updated digital instrument is essentially a 'black-box,' not revealing its internal mechanisms and being too fast for observing its signal processes. While the old seismometers and recording systems have been disposed of long since, stacks of analog seismograms continue to languish in observatories' back rooms. In our study, we develop some classroom exercises for studying earthquakes at the mid- to high-school level using these analog seismograms. These exercises include 1) reading the features of seismic records, 2) measuring the S-P time, 3) converting the hypocentral distance from Omori's distance formula, 4) locating the epicenter/hypocenter using the S-P times of surrounding stations, and 5) estimating earthquake magnitude using the Tsuboi's magnitude formula. For this calculation we developed a 'nomogram'--a graphical paper calculator created using a Python-based freeware tool named 'PyNomo.' We tested many seismograms and established the following rules: 1) shallow earthquakes are appropriate for using the Tsuboi's magnitude formula; 2) there is no saturation at peak amplitude; 3) seismograms make it easy to read S-P time and maximum amplitude; 4) they also make it is easy to locate an earthquake's hypocenter. For advanced study, particularly of the source mechanisms of earthquakes, P-wave arrival phases are typically determined from wave records. In this exercise, we use displacement-based records for use by students for recognizing these arrival phases directly rather than by using velocity or acceleration records. Following are some advantages of using these JMA-59-type seismograms: 1) displacement records are easy to compare with real ground motion; 2) ink records can help young students visualize the analog images of a legacy seismograph; 3) scale dimensions such as amplitude of 100 times and time scale of 1 mm/s are easy to explain while using these seismograms as an exercise resource. We confirmed the availability of our exercises by cooperation with our high-school students. We will offer some practical examples at the conference. Keywords: JMA-59 type seismograph, seismograms, hypocenter location, magnitude estimation, educational tool, classroom exercise, high-school
Directory of Open Access Journals (Sweden)
Bagus Jaya Santosa
2008-11-01
Full Text Available The seismogram comparison between the measured and synthetics seismogram has been carried out in observation station of UGM, where the seismograms are excited by earthquakes that occurred at North Sumatra, Sumbawa, Sunda Strait, around North Celebes and PNG. The ray paths from earthquake's hypocenter to UGM give opportunity to understand the earth structure alongside the front area of subduction zone. The calculation of synthetic seismogram needs input in the form of earth model, the Centroid Moment Tensor (CMT solution of the earthquake and location of observation station, as well as the relevant date file response of the observation station. Waveform comparison and fitting at surface wave indicate that speed's anomalies in the lithosphere have negative character in front area of subducted zone, but become positive for northern area of subduction zone. By paying attention to waveform of Love surface wave, it is obtained, that this waveform are sensitive to the change of earth crust thickness, while Rayleigh waveform is not sensitive. Heterogeneity is not only occurred in the lithosphere, but also in deeper earth layers, until Core Mantle Boundary (CMB. Different corrections are needed to make the fitting at S secondary wave, but also at depth wave and its repetitions. The result of this research shows that the research area, which is located in the front of subduction zone has anomalies at S speed of at deeper earth layers which than the lithosphere. The earth structure as the result of this research differs from the other seismological results, where they used the methods, which are based on inversion of arrival time data of body wave and dispersion analysis on surface wave.
Simulation of seismograms in a 2-D viscoelastic Earth by pseudospectral methods
Energy Technology Data Exchange (ETDEWEB)
Carcione, Jose M [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste (Italy); Helle, Hans B [Norsk Hydro a.s., 0 and E Research Centre, Bergen (Norway); Seriani, Geza [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste (Italy); Plasencia Linares, Milton P [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, La Plata (Argentina)
2005-04-15
Using an improved global pseudospectral modeling algorithm we synthesize seismograms generated by oceanic and continental earthquakes. Attention is given to attenuation, to explicit modeling of boundary conditions at the ocean-bottom interface, simulation of the Rayleigh window and interface-wave propagation. The algorithm is based on Fourier and Chebyshev differential operators and a domain-decomposition technique - one grid for the fluid and another grid for the solid. Wave propagation in the oceanic and continent crusts and mantle is modeled by using a viscoelastic stress-strain relation based on memory variables. The main physical phenomena associated with an ocean-crust system are modeled, including Scholte waves, leaking Rayleigh waves, dispersive modes, and the Rayleigh-window phenomenon due to a minimum in the reflection coefficient of the ocean bottom, which has not been simulated with direct methods. In particular, we model Rayleigh modes (mainly the M11 mode), and coupled Rayleigh-Scholte waves, for which the dispersion relation is solved in simple cases. Also, we model the effects of random. [Spanish] El algoritmo de modulacion seudoespectral es mejorado y aplicado a la simulacion de sismogramas generados por sismos oceanicos y continentales, como atencion a la atenuacion y a la modelacion explicita de condiciones a la frontera en el fondo oceanico y a la simulacion de la ventana de Rayleigh y la propagacion en interfases. El algoritmo se basa en los operadores diferenciales de Fourier y de Chebyshev con una tecnica de decomposicion de dominios, una malla para el fluido y otra para el solido. Para la propagacion se usa una relacion de esfuerzo-deformacion basada en variables de memoria. Entre los fenomenos modelados se incluyen las ondas de Scholte, las ondas evanescentes de Rayleigh y los modos dispersivos, asi como la ventana de Rayleigh, un minimo del coeficiente de reflexion en el fondo oceanico que nunca ha sido simulado con metodos directos. Hemos modelado los modos de Rayleigh (principalmente M11) y las ondas acopladas Rayleigh-Scholte, resolviendo la relacion de dispersion para casos simples. Se modelo tambien efectos de inhomogeneidades aleatorias en la corteza y manto mediante una funcion de autocovarianza tipo von Karman que simula los efectos de dispersion de ondas. El programa bidimensional permite una variacion material general y una caracterizacion completa y exacta de la respuesta para sismos oceanicos y continentales. Se desarrolla un ejemplo para un sismograma originado en la region del Atlantico Sur.
Fontes, L R; 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 dynamics occur. Our derivations express the scaling limit via coalescing Brownian paths and a ``Brownian space-time spanning tree,'' which also yields other aging functions, such as the persistence probability of no spin flip at 0 between tw and tw+t.
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.
Coal-seismic, desktop computer programs in BASIC; Part 7, Display and compute shear-pair seismograms
Hasbrouck, W.P.
1983-01-01
Processing of geophysical data taken with the U.S. Geological Survey's coal-seismic system is done with a desk-top, stand-alone computer. Programs for this computer are written in the extended BASIC language utilized by the Tektronix 4051 Graphic System. This report discusses and presents five computer pro grams used to display and compute shear-pair seismograms.
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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.
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.
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.
Ferrari, G.; Pino, N. A.
2003-04-01
The study of the great earthquakes and the analysis of their tectonic significance are very important elements in the evaluation of seismic potential, seismic hazard and risk. The analysis of the seismograms of historical earthquakes plays a crucial role in understanding the patterns of deformation energy release, the characteristics of propagation and interaction of the seismic waves with the inhabited areas, in the areas affected by these events. The recovery and reproduction of historical seismograms and the indispensable information contained therein, on the instruments that recorded them and their related characteristics, often become difficult and laborious operations that deprive research of a disproportionate amount of human and economic resources in relation to the objective complexity of the matter. These difficulties have so far much reduced the number of study cases and have been a disincentive to researchers interested in dealing with this important research strand. In order to overcome these difficulties the EUROSEISMOS has been started up (http://80.117.141.2/Es_web); this is a project for collaboration between researchers and research bodies having a long tradition of seismic monitoring, with the following main objectives: 1) the recovery, with the reproduction at the SISMOS centre of the INGV, of the seismograms of the most important historical earthquakes (1895 1980) in the Euro-Mediterranean area in the 20th century; 2) benchmarking of experiences on the processing of seismographic historical data; 3) creation of a permanent workgroup on these aspects. So far 29 researchers belonging to 26 countries from Finland to Algeria, and from Georgia to Portugal, have joined the project. The approximately 300 earthquakes of primary interest for the researchers involved have been collected in a catalogue, and early in 2003 the first reproductions of seismograms were started.
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.
Study of East Kazakh explosions and propagation in Central Asia using regional Chinese seismograms
International Nuclear Information System (INIS)
Seismograms recorded at the Urumchi Station in northwestern China from eleven Asian events including seven presumed East Kazakh nuclear explosions were analyzed. Group velocity dispersion curves of Rayleigh waves were measured at short periods on paths through basin and fold belt terrains. At 10 sec period, the velocities on paths over sedimentary basins are 25% slower than velocities on paths over fold belts. We interpret those differences in velocities to be due to the great thicknesses of sedimentary deposits in basin terrains. Epicentral locations were estimated using differential travel times between P/sub n/ and L/sub g/ and particle motions of Rayleigh waves measured on a single three-component record. For a 1000 km path, the location errors (one standad deviation) are about +-125 km in azimuth and +-30 km in distance. In addition, systematic errors due to structural effects on surface-wave paths and on velocities of regional phases are shown to seriously bias location estimates of several events. We applied a differential phase method to Rayleigh waves from the East Kazakh explosions and found that signals of all events are in-phase with signals from the reference event on 10/12/80. Thus, there is no evidence for phase reversals or shifts at the Urumchi station in the frequency band where signal to noise ratio is good and where assumptions of the method are valid. Seismic moments of explosions were estimated using models of explosion sources with associated tectonic release. Observed amplitude spectra of Rayleigh waves were richer in high frequencies than predicted by the model. This could be a source effect related to source medium excitation (i.e., Green's functions) or a path effect caused by energy focussing and/or amplifications. We discuss the potential bias in the estimates of moment due to assumptions/limitations. 24 references, 16 figures, 6 tables
Development of earthquake early warning system using real time signal of broadband seismogram
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.
Directory of Open Access Journals (Sweden)
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.
Twardzik, C; Madariaga, R; S. Das; Custódio, S.
2012-01-01
We explore a recently developed procedure for kinematic inversion based on an elliptical subfault approximation. In this method, the slip is modelled by a small set of elliptical patches, each ellipse having a Gaussian distribution of slip. We invert near-field strong ground motion for the 2004 September 28 M w 6.0 Parkfield, California, earthquake. The data set consists of 10 digital three-component 18-s long displacement seismograms. The best model gives a moment of 1.21 × 10 18 N m, with s...
Sarker, Swagotom
The creation of an n-n heterojunction between TiO2 nanotubes (T_NT) and CdTe nanocrystals (which mostly exist as p-type) is crucial for realizing the benefits of efficient directional charge transport in a photoanode of 1D/0D architecture. The presented one-pot solvothermal approach leverages temperature control to achieve linker-free spatial distribution of CdTe nanocrystals (NCs) on T_NT resulting in highly efficient optical and photoelectrochemical responses. As a result of this positive outcome, a comparative study between the solvothermal approach and the linker mediated approach was performed on water oxidation with CdS NC decorated T_NT. Solvothermally synthesized T_NT/CdS photoelectrode presents ˜600% higher value of short-circuit current density (Isc) than that of the plain T_NT (0.95 mA/cm2); in addition, it demonstrates 4.20-fold increased applied-bias-to photoconversion efficiency (ABPE) in comparison with the lone T_NT (0.77%). However, linker mediated T_NT/MPA-CdS photoelectrode exhibits relatively lower value of I sc (2.51 mA/cm2) and ABPE (1.79 %).
Partitioned Waveform Inversion, From Tens to Millions of Seismograms: A Journey of Discovery
Lebedev, S.; Schaeffer, A. J.
2014-12-01
In a landmark paper a quarter of a century ago, Nolet (1990) applied his newly developed method, Partitioned Waveform Inversion (PWI), to data from a new broadband array in Europe, the Network of Autonomously Recording Seismographs (NARS). The deployment of NARS was followed by deployments of numerous other arrays, resulting in an explosive growth in the amount of broadband data worldwide. The PWI method, in turn, has proven to be extremely effective in utilizing the growing data volumes. Over the last 20+ years, it has yielded a steady stream of discoveries on the Earth's structure and dynamics. PWI extracts information on Earth structure from both surface and body waves within full seismic waveforms, putting this information in the form of linear equations with uncorrelated uncertainties. Early on, PWI has been applied successfully at the continental scale for upper-mantle tomography, at the regional scale for Moho-depth mapping, and even at the local scale for imaging shallow marine sediments. Automated multimode inversion developed on the basis of PWI has taken the method to global applications, and today it has been applied to millions of seismograms (all broadband data available from international data centers). Waveform tomography stemming from the work of Nolet (1990) now reveals the global structure and anisotropy of the upper mantle in great detail. It provides regional resolution (at the scale of tectonic units) in many regions that are well-sampled by the data. Beneath Tibet, for example, complex subduction of the cold, high-velocity Indian lithosphere is imaged in detail in the upper mantle, while azimuthal anisotropy resolved within the crust shows the flow that accommodates the India-Asia lithospheric convergence. At greater depths, in the mantle transition zone, a belt of high-velocity anomalies reveals subducted lithospheric fragments along the entire Tethys convergence zone. Globally, waveform tomography enables us to examine the heterogeneity of the lithosphere and underlying mantle from different perspectives: multimode surface-wave dispersion, shear-velocity tomography, and tectonic regionalization. Nolet, G., 1990. Partitioned waveform inversion and two-dimensional structure under the Network of Autonomously Recording Seismographs, J.Geophys. Res. 95, 8499-8512.
Two extensions of 1D Toda hierarchy
International Nuclear Information System (INIS)
The extended Toda hierarchy of Carlet, Dubrovin and Zhang is reconsidered in light of a 2 + 1D extension of the 1D Toda hierarchy constructed by Ogawa. These two extensions of the 1D Toda hierarchy turn out to have a very similar structure, and the former may be thought of as a kind of dimensional reduction of the latter. In particular, this explains an origin of the mysterious structure of the bilinear formalism proposed by Milanov.
International Nuclear Information System (INIS)
Seismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100-120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques. In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the 20. century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) - both of which are the strongest ever recorded instrumentally in their respective countries - and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismo-genic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Appennines. (author)
Batllo-Ortiz, J.; Custodio, S.; Macia, R.; Teves-Costa, P.
2012-12-01
The seismicity rate in the contact of the Nubian and Euro-Asiatic plates along the Azores-Gibraltar region can be considered moderate. Nevertheless, large earthquakes do occur, as is well known from historical records. The sensibility of seismographic networks to earthquakes with oceanic origin has been extremely low until recent times. Oceanic M5 earthquakes have not been consistently recorded up to the second third of the XX century, precluding a proper knowledge of seismicity rates and other parameters of interest for earthquake hazard. Nevertheless, information for some events does exist, most of which remains to be properly studied. In this paper we analyze historical data for the 11th July, 1915 earthquake, which occurred offshore and was felt over the whole mainland Portugal. This event is one of the largest occurred during the instrumental period in the region of diffuse seismicity around the Gorringe bank. However it has been little studied, probably because it did not cause serious damage. The 11th July, 1915 earthquake is of great interest due to its size, estimated on the order of M6, and to its unique location with respect to the regions of large earthquakes in the Atlantic. In this paper, we present source parameters for this earthquake based on the analysis of the available contemporary seismograms and related documents. After throughout collection and selection, 23 seismograms obtained at 11 different European stations were digitized and processed. The event was relocated and its magnitude recalculated. Its focal mechanism has also been studied through waveform modeling and first motion polarity. We present the results of this analysis, compare the source of the 1915 earthquake with that of present earthquakes in the same region, and interpret the new results in light of the regional seismicity and seismo-tectonics.
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.
75 FR 11072 - Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines
2010-03-10
...Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines AGENCY: Federal Aviation Administration...Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. That AD requires initial and repetitive...Arriel 1D, 1D1, and 1S1 turboshaft engines that do not incorporate mod TU 347....
Quasi-1D parahydrogen in nanopores
Omiyinka, Tokunbo
2015-01-01
The low temperature physics of parahydrogen (ph2) confined in cylindrical channels of diameter of the order of 1 nm is studied theoretically by Quantum Monte Carlo simulations. On varying the attractive strength of the wall of the cylindrical pore, as well as its diameter, the equilibrium phase evolves from a single quasi-1D channel along the axis, to a concentric cylindrical shell. It is found that the quasi-1D system retains a strong propensity to crystallization, even though on weakly attractive substrates quantum fluctuations reduce somewhat such a tendency compared to the purely 1D system. No evidence of a topologically protected superfluid phase (in the Luttinger sense) is observed. Implications on the possible existence of a bulk superfluid phase of parahydrogen are discussed
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.
International Nuclear Information System (INIS)
In search of a new source discriminant based on the characteristics of PP signal, a study has been made by special further processing of Gauribidanur array (GBA) seismograms of underground explosions at Nevada Test Site (NTS) in Southern Nevada and of tectonic earthquakes in five provinces in the Western United States (US), both class of events being situated in the far teleseismic distance range (120deg
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.
DESIGN PACKAGE 1D SYSTEM SAFETY ANALYSIS
Energy Technology Data Exchange (ETDEWEB)
L.R. Eisler
1995-02-02
The purpose of this analysis is to systematically identify and evaluate hazards related to the Yucca Mountain Project Exploratory Studies Facility (ESF) Design Package 1D, Surface Facilities, (for a list of design items included in the package 1D system safety analysis see section 3). This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach was used since a radiological System Safety analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the Design Package 1D structures/systems/components in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the structure/system/component (S/S/C) design, (2) add safety devices and capabilities to the designs that reduce risk, (3) provide devices that detect and warn personnel of hazardous conditions, and (4) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions. The scope of this analysis is limited to the Design Package 1D structures/systems/components (S/S/Cs) during normal operations excluding hazards occurring during maintenance and ''off normal'' operations.
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
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.
A large 1D retroreflective autostereoscopic display
Smithwick, Quinn Y. J.; Ranieri, Nicola
2015-03-01
We aim to produce a wide field-of view large autostereoscopic display for multiple viewers based on a 1D retroreflective screen and overheard microprojectors. The 1D retroreflective screen consists of retroreflector, anisotropic diffuser, and embedded fiber-optic array with optical sensors. Microprojectors modified with wide angle converter lenses are mounted unobtrusively over each viewing location. Each projector's structured lighting is detected by the screen's sensor array for calibration. Pin-cushion distortion correction, rectification and cross-talk reduction are implemented for proper stereo fusion. We examine common viewing scenarios of single viewer autostereoscopic projection, multiprojector automultiscopic projection, side by side multiviewer common and independent autostereoscopic projection, and frontback autostereoscopic projection.
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
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...
International Nuclear Information System (INIS)
While waiting for the increment of strong motion data, especially for earthquake prone areas outside the United States and Japan, a very useful approach to perform immediate site specific seismic hazard assessment is the development and use of modelling tools. They are based, on one hand, on the theoretical knowledge of the physics of the seismic source and of wave propagation and, on the other hand, on the exploitation of the relatively rich database, already available, that can be used for the definition of the source and structural models. With these input data we model the ground motion using the mode-coupling approach for sharply varying laterally heterogeneous anelastic media, i.e. computing the coupling coefficients for the modes transmitted and reflected at the vertical interface, between two quarter spaces in welded contact. The formalism can be readily applied to any laterally heterogeneous structure by using a custom series of layered anelastic structures in welded contact at vertical interfaces. The case of seismic wave propagation in smooth varying laterally heterogeneous layered media, is solved with an approximation, equivalent to WKBJ method. The theoretical formulation that combines both WKBJ and the coupling coefficients approaches, is implemented in a computer program package. The computer code we have developed allows us to calculate synthetic seismograms for a wide range of laterally inhomogeneous layered anelastic media. As a case study we use an earthquake which occurred on December 16, 1999 (mb=4.8) beneath the Bartlett sea trough, south of Santiago de Cuba city, that was recorded by an accelerometer (SMA-100) placed in Rio Carpintero (RCC) station, at an epicentral distance of about 30 Km. The path travelled by the waves corresponds to a complex structure from undersea source to inland seismic station. A good fit between the observed transverse component (SH-waves) of acceleration and the corresponding synthetic signal is obtained for a seismic moment of M0-7,1.1022. (author)
Venkat Ramachandran; Christian S. Gargour; Ravi P. Ramachandran
2007-01-01
A method for the generation of discrete-domain two-dimensional (2-D) transfer functions possessing variable magnitude and contour characteristics is presented in this paper. The proposed method is based upon a configuration constituted by two 1-D filters in cascade and a feedback loop. Each of these 1-D filter is designed to have a monotonic magnitude frequency response. This is obtained by performing one or several integrations, either with respect to ? or ?2, of the denominator of a magnitu...
International Nuclear Information System (INIS)
Radiative instabilities that can develop in plasmas subjected to external heating and radiative cooling are of great importance in edge plasmas of tokamaks and stellarators. They will be analyzed in this paper on the basis of the 1d heat conduction equation. Bifurcation and time evolution of temperature profiles along magnetic field lines between two target plates have been reported. The simple model functions used there are applied here together with methods proved to be useful in nonlinear theories of dynamical systems in order to investigate stable, unstable and chaotic solutions of the 1d heat conduction equation. We consider the model of a radiative plasma with periodically (period ?) injected impurities. In order to show the basic mechanism we discuss at first the time-dependent problem which leads to an equation that can be integrated piecewise exactly analogous to the equation of motion for the periodically kicked rotator. Solution and Lyapunov stability analysis of that one-dimensional radiative map show the existence of stable and unstable solutions. Calculating attractors and Lyapunov exponents in dependence of parameters like power input or period ? shows the appearance of periodical solutions followed by period doubling and finally resulting in chaos in the radiative plasma. Second, we consider 1d and time-dependent problems by calculating profiles and attractors. Enhancing the period ? starting from ? = 0 (stationary problem) rediscovers the known routes to chaos in spatial extension like period doubling or intermittence. (orig.)
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).
The Role of O(1D) in the Oxidation of Si(100)
International Nuclear Information System (INIS)
Oxidation of silicon with neutral atomic oxygen species generated in a rare gas plasma has recently been shown to produce high-quality thin oxides. It has been speculated that atomic oxygen in the first excited state, O(1D), is a dominant reactive species in the oxidation mechanism. In this study, we investigate the role of O(1D) in silicon oxidation in the absence of other oxidizing species. The O(1D) is generated by laser-induced photodissociation of N2O at 193 nm. We find that, at 400?C, O(1D) is effective in the initial stages of oxidation, but the oxide growth rate falls dramatically past 1.5 nm. Oxide films thicker than 2 nm were unachievable regardless of oxidation time or N2O partial pressure (0.5-90 mTorr), indicating O(1D) cannot be a dominant reactive species in thicker oxidation mechanisms. We suggest that quenching of O(1D) to O(3P) (ground state) during diffusion through thicker oxides results in drastically slower oxidation kinetics. In contrast, oxidation with a vacuum ultraviolet (VUV) excimer lamp operating at 172 nm resulted in oxide thicknesses up to 4 nm. Thus, other species produced in plasmas and excimer lamps, such as molecular and atomic ions, photons, and free and conduction band electrons, play a dominant role in the rapid oxidation mechanism of thicker oxides (> 2 nm)
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.
Blood flow quantification using 1D CFD parameter identification
Brosig, Richard; Kowarschik, Markus; Maday, Peter; Katouzian, Amin; Demirci, Stefanie; Navab, Nassir
2014-03-01
Patient-specific measurements of cerebral blood flow provide valuable diagnostic information concerning cerebrovascular diseases rather than visually driven qualitative evaluation. In this paper, we present a quantitative method to estimate blood flow parameters with high temporal resolution from digital subtraction angiography (DSA) image sequences. Using a 3D DSA dataset and a 2D+t DSA sequence, the proposed algorithm employs a 1D Computational Fluid Dynamics (CFD) model for estimation of time-dependent flow values along a cerebral vessel, combined with an additional Advection Diffusion Equation (ADE) for contrast agent propagation. The CFD system, followed by the ADE, is solved with a finite volume approximation, which ensures the conservation of mass. Instead of defining a new imaging protocol to obtain relevant data, our cost function optimizes the bolus arrival time (BAT) of the contrast agent in 2D+t DSA sequences. The visual determination of BAT is common clinical practice and can be easily derived from and be compared to values, generated by a 1D-CFD simulation. Using this strategy, we ensure that our proposed method fits best to clinical practice and does not require any changes to the medical work flow. Synthetic experiments show that the recovered flow estimates match the ground truth values with less than 12% error in the mean flow rates.
String Matching and 1d Lattice Gases
Mungan, M
2004-01-01
In a recent paper, Bilge et al. (q-bio.GN/0409023) have derived a set of recursion relations for the probability of encountering (matching) a given binary string of length $l$ at least once in a random string of length $k$. Using the method introduced in Mungan et al. (q-bio.MN/0406049), we obtain a closed form solution for the matching probability in the general case where the letters of the string are derived from an alphabet of $r$ letters. We show that the problem of determining string matching probabilities can be recast into a problem of calculating the partition function of a 1d lattice gas with interacting particles. We extract the large $k$ behavior of the matching probability and also calculate the probability that a given string is matched precisely $n$ times. The case of allowing imperfect matches is also considered.
Enhanced Friedel oscillations in attractively interacting 1D Fermi gases
McKenney, J R; Porter, W J; Drut, J E
2015-01-01
Many-fermion systems bound by hard walls display non-trivial density profiles characterized by so-called Friedel oscillations. In non-interacting systems, the characteristic scale of the oscillations is $2 k^{}_F$, where $k^{}_F$ is the Fermi momentum, while repulsive interactions tend to generate Wigner-crystal oscillations at $4 k^{}_F$. We take a closer look at interacting systems in the presence of strong pairing correlations, such as those realized experimentally with ultracold atoms. We use ab initio lattice Monte Carlo methods to study the density profiles of few- to many-fermion systems in 1D, in the presence of hard-wall boundary conditions and attractive interactions. Additionally, we compute the ground-state energy and the momentum distribution.
Axial turbomachine modelling with a 1D axisymmetric approach
International Nuclear Information System (INIS)
This work concerns the design and safety analysis of direct cycle gas cooled reactor. The estimation of compressor and turbine performances in transient operations is of high importance for the designer. The first goal of this study is to provide a description of compressor behaviour in unstable conditions with a better understanding than the models based on performance maps ('traditional' 0D approach). A supplementary objective is to provide a coherent description of the turbine behaviour. The turbomachine modelling approach consists in the solution of 1D axisymmetric Navier-Stokes equations on an axial grid inside the turbomachine: mass, axial momentum, circumferential momentum and total-enthalpy balances are written. Blade forces are taken into account by using compressor or turbine blade cascade steady correlations. A particular effort has been developed to generate or test correlations in low mass flow and negative mass flow regimes, based on experimental data. The model is tested on open literature cases of the gas turbine aircraft community. For compressor and turbine, steady situations are fairly described, especially for medium and high mass flow rate. The dynamic behaviour of compressor is also quite well described, even in unstable operation (surge): qualitative tendencies (role of plenum volume and role of throttle) and some quantitative characteristics (frequency) are in a good agreement with experimental data. The application to transient simulations of gas cooled nuclear reactors is concentrated on the hypothetical 10 in. break accident. The results point out the importance of the location of the pipe rupture in a hypothetical break event. In some detailed cases, compressor surge and back flow through the circuit can occur. In order to be used in a design phase, a simplified model of surge has also been developed. This simplified model is applied to the gas fast reactor (GFR) and compared quite favourably with 1D axisymmetric simulation results
(F1, D1, D3) Bound State, Its Scaling Limits and SL(2,Z) Duality
Cai, R G; Cai, Rong-Gen; Ohta, Nobuyoshi
2000-01-01
We investigate the properties of the bound state (F1, D1, D3) in IIB supergravity in three different scaling limits and the $SL(2, Z)$ transformation of the resulting theories. In the simple decoupling limit with finite electric and magnetic components of NS $B$ field, the worldvolume theory is the ${\\cal N}$=4 SYM and the supergravity dual is still the $AdS_5 \\times S^5$. In the large magnetic field limit with finite electric field, the theory is the noncommutative super Yang-Mills (NCSYM), and the supergravity dual is the same as that without the electric background. We show how to take the decoupling limit of the closed string for the critical electric background and finite magnetic field, and that the resulting theory is the noncommutative open string (NCOS) with both space-time and space-space noncommutativity. It is shown that under the $SL(2, Z)$ transformation, the SYM becomes itself with different coupling constant, the NCSYM is mapped into the NCOS, but the NCOS in general transforms into another NC...
Hemi-omnidirectional lasing from a cholesteric liquid crystal layer on a 1D photonic crystal film
International Nuclear Information System (INIS)
We herein report on a hybrid photonic band gap (PBG) system, which was fabricated using a cholesteric liquid crystal (CLC) layer on a 1-dimensional (1D) photonic crystal (PC) film, i.e., hybrid 'CLC/1D PC'. The CLC layer is made of nematic liquid crystal monomers embedded in polymeric helical CLC networks, thereby exhibiting a field-induced reorientational undulation of the helical axis. It is shown that intensity-controllable circularly polarized laser emissions may be generated at the wavelength of the high-energy band edge mode of the CLC layer in the dye-doped 'CLC/1D PC' PBG structure. The handedness of the lasing light corresponds to the handedness of the CLC layer used. Moreover, the direction of propagation of laser emissions could be manipulated from uni- to hemi-omnidirectional for the hybrid 'CLC/1D PC' PBG structure by applying an electric field.
Lifescience Database Archive (English)
Full Text Available 1D6R ?? Soybean Glycine max (L.) Merrill Bowman-Birk Type Proteinase Inhibitor Precursor Glyci ... Warkentin, G.Wenzl, P.Flecker Crystal Structure Of Cancer ... Chemopreventive Bowman-Birk Inhibitor In Ternary C ...
1D Nanostructures: Controlled Fabrication and Energy Applications
Energy Technology Data Exchange (ETDEWEB)
Hu, Michael Z. [ORNL
2013-01-01
Jian Wei, Xuchun Song, Chunli Yang, and Michael Z. Hu, 1D Nanostructures: Controlled Fabrication and Energy Applications, Journal of Nanomaterials, published special issue (http://www.hindawi.com/journals/jnm/si/197254/) (2013).
Probing 1D super-strongly correlated dipolar quantum gases
Citro, Roberta; De Palo, Stefania; Orignac, Edmond; Pedri, Paolo; Chiofalo, Maria-Luisa
2009-01-01
One-dimensional (1D) dipolar quantum gases are characterized by a very special condition where super-strong correlations occur to significantly affect the static and dynamical low-energy behavior. This behavior is accurately described by the Luttinger Liquid theory with parameter K< 1. Dipolar Bose gases are routinely tudied in laboratory with Chromium atoms. On the other hand, 1D realizations with molecular quantum gases can be at reach of current experimental expertises, allowing to explore...
Quasi-1D graphene superlattices formed on high index surfaces
Lin, Chenfang; Huang, Xiangqian; Ke, Fen; Jin, Chenhao; Tong, Nai; Yin, Xiuli; Gan, Lin; Guo, Xuefeng; Zhao, Ruguang; Yang, Weisheng; Wang, Enge; Hu, Zonghai
2014-01-01
We report preparation of large area quasi-1D monolayer graphene superlattices on a prototypical high index surface Cu(410)-O and characterization by Raman spectroscopy, Auger electron spectroscopy (AES), low energy electron diffraction (LEED), scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The periodically stepped substrate gives a 1D modulation to graphene, forming a superlattice of the same super-periodicity. Consequently the moire pattern i...
A new 1D-multigroup-discrete ordinates algorithm for neutron transport
International Nuclear Information System (INIS)
A variation of the multigroup SN method, called the MultiGroup Converged SM (MGCSN) method has been constructed to generate benchmark quality solutions to the 1D multigroup transport equation. The method is woven around two convergence accelerators that accelerate the convergence of sequences to their limits. The Romberh acceleration is well known to accelerate convergence of a discretized numerical scheme to a low discretization error. The Wynn-epsilon scheme is a Pade' approximant for a specially constructed series that has a desired limit. Romberg acceleration is applied to the 1D transport equation to reduce the spatial error; while, the Wynn-epsilon acceleration converges the solution in quadrature order. The MGCSN method is presented in detail and demonstrated for fixed source problems; however, its application to critical system is also demonstrated. (author)
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.
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.
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).
𝒩-Structures Applied to Closed Ideals in BCH-Algebras
Directory of Open Access Journals (Sweden)
Mehmet Ali Öztürk
2010-01-01
Full Text Available The notions of 𝒩-subalgebras and 𝒩-closed ideals in BCH-algebras are introduced, and the relation between 𝒩-subalgebras and 𝒩-closed ideals is considered. Characterizations of 𝒩-subalgebras and 𝒩-closed ideals are provided. Using special subsets, 𝒩-subalgebras and 𝒩-closed ideals are constructed. A condition for an 𝒩-subalgebra to be an 𝒩-closed ideal is discussed. Given an 𝒩-structure, the greatest 𝒩-closed ideal which is contained in the 𝒩-structure is established.
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.
Nonreciprocity of edge modes in 1D magnonic crystal
International Nuclear Information System (INIS)
Spin waves propagation in 1D magnonic crystals is investigated theoretically. Mathematical model based on plane wave expansion method is applied to different types of magnonic crystals, namely bi-component magnonic crystal with symmetric/asymmetric boundaries and ferromagnetic film with periodically corrugated top surface. It is shown that edge modes in magnonic crystals may exhibit nonreciprocal behaviour at much lower frequencies than in homogeneous films. - Highlights: • Magnetostatic surface spin waves in 1D magnonic crystals were studied theoretically. • Mathematical model is based on plane wave method. • Mathematical model was applied to different types of magnonic crystals. • Stop band formation and nonreciprocity were obtained
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.
Simulation of Organic Solar Cells Using AMPS-1D Program
Samah. G. Babiker; Yong Shuai
2012-01-01
The analysis of microelectronic and photonic structure in one dimension program [AMPS-1D] program has been successfully used to study inorganic solar cells. In this work the program has been used to optimize the performance of the organic solar cells. The cells considered consist of poly(2-methoxy-5-(3,7- dimethyloctyloxy)-1,4-phenylenevinylene) [MDMO-PPV
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.
Lifescience Database Archive (English)
Full Text Available 1D8U ?? Rice Oryza sativa L. Non-Symbiotic Hemoglobin 1 Name=Hb1; Synonyms=Glb1a; Oryza Sativa ... rgrove, E.A.Brucker, B.Stec, G.Sarath, R.Arredondo-Peter , R.V.Klucas, J.S.Olson, G.N.Phillips Jr. Crystal S ...
Scattering approach to classical quasi-1D transport
Kogan, Eugene
1996-01-01
General dynamical transport of classical particles in disordered quasi-1D samples is viewed in the framework of scattering approach. Simple equation for the transfer-matrix is obtained within this unified picture. In the case of diffusive transport the solution of this equation exactly coincides with the solution of diffusion equation.
P10-S A Novel Protein Database Search Algorithm for 1D and 2D LC-MS Data
G. Li; Golick, D.; Dyson, B.; Silva, J. C.; Liu, H.; Vissers, J.P.C.; Gebler, J. C.; Gorenstein, M. V.; Geromanos, S. J.
2007-01-01
A novel, “Ion Accounting” algorithm has been developed for protein identification using time-resolved, LC-MSE data from 1D and 2D LC-MS experiments. The data from a 1D LC-MS analysis generate a series of precursor-product tables that are initially queried against a protein database using the “Ion Accounting” algorithm. Hereby each precursor and product is associated with only single peptide identification. The database search is a hierarchal process containing three modules. With the first mo...
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.
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.
Phase-sensitive detection of Bragg scattering at 1D optical lattices
Slama, S; Deh, B; Ludewig, A; Zimmermann, C; Courteille, P W; Courteille, Ph.W.
2004-01-01
We report on the observation of Bragg scattering at 1D atomic lattices. Cold atoms are confined by optical dipole forces at the antinodes of a standing wave generated by the two counter-propagating modes of a laser-driven high-finesse ring cavity. By heterodyning the Bragg-scattered light with a reference beam, we obtain detailed information on phase shifts imparted by the Bragg scattering process. Being deep in the Lamb-Dicke regime, the scattered light is not broadened by the motion of individual atoms. In contrast, we have detected signatures of global translatory motion of the atomic grating.
Hidden nonlinear su(22) superunitary symmetry of N=2 superextended 1D Dirac delta potential problem
Correa, Francisco; Plyushchay, Mikhail S
2008-01-01
We show that the N=2 superextended 1D quantum Dirac delta potential problem is characterized by the hidden nonlinear su(22) superunitary symmetry. The supersymmetry admits three distinct Z_2-gradings, that results in a separation of 16 integrals of motion into different sets of 8 bosonic and 8 fermionic operators generating two 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 by Gershun and Tkach for investigation of spontaneous supersymmetry breaking.
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.
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...
Second order effect of twist deformation in the D1D5 CFT
Carson, Zaq; Mathur, Samir D
2015-01-01
Thermalization in the D1D5 CFT should occur via interactions caused by the twist operator, which deforms the theory off its free orbifold point. Earlier studies investigating this deformation at first order did not show any definite evidence of thermalization. In this paper we study the deformation to second order, where we do expect to see the effects that should give thermalization. We compute the effect of two twist operators on an initial vacuum state, which generates a squeezed state analogous to the case for a single twist. We obtain expressions for the Bogoliubov coefficients in this 2-twist case.
Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses
Indian Academy of Sciences (India)
K D Rathod; P K Singh; Vasant Natarajan
2014-09-01
We demonstrate the 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° with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate the selective deflection of the bosonic isotope 174Yb and the fermionic isotope 171Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.
Exciton formation and annihilation during 1D impact excitation of carbon nanotubes.
Marty, L; Adam, E; Albert, L; Doyon, R; Ménard, D; Martel, R
2006-04-01
Near-infrared electroluminescence was recorded from unipolar single-wall carbon nanotube field-effect transistors at high drain-source voltages. High resolution spectra reveal resonant light emission originating from the radiative relaxation of excitons rather than heat dissipation. The electroluminescence is induced by only one carrier type and ascribed to 1D impact excitation. An emission quenching is also observed at high field and attributed to an exciton-exciton annihilation process and free carrier generation. The excitons' binding energy in the order of 270 meV for 1.4 nm SWNTs is inferred from the spectral features. PMID:16712017
Ultrahigh sensitivity of Au/1D ?-Fe2O3 to acetone and the sensing mechanism.
Gunawan, Poernomo; Mei, Lin; Teo, Jaclyn; Ma, Jianmin; Highfield, James; Li, Qiuhong; Zhong, Ziyi
2012-10-01
Hematite (?-Fe(2)O(3)) is a nontoxic, stable, versatile material that is widely used in catalysis and sensors. Its functionality in sensing organic molecules such as acetone is of great interest because it can result in potential medical applications. In this report, microwave irradiation is applied in the preparation of one-dimensional (1D) ?-FeOOH, thereby simplifying our previous hydrothermal method and reducing the reaction time to just a few minutes. Upon calcination, the sample was converted to porous ?-Fe(2)O(3) nanorods, which were then decorated homogeneously by fine Au particles, yielding Au/1D ?-Fe(2)O(3) at nominally 3 wt % Au. After calcination, the sample was tested as a potential sensor for acetone in the parts per million range and compared to a similarly loaded Pt sample and the pure 1D ?-Fe(2)O(3) support. Gold addition results in a much enhanced response whereas Pt confers little or no improvement. From tests on acetone in the 1-100 ppm range in humid air, Au/1D ?-Fe(2)O(3) has a fast response, short recovery time, and an almost linear response to the acetone concentration. The optimum working temperature was found to be 270 °C, which was judged to be a compromise between the thermal activation of lattice oxygen in hematite and the propensity for acetone adsorption. The surface reaction was investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and a possible sensing mechanism is proposed. The presence of Au nanoparticles is believed to promote the dissociation of molecular oxygen better in replenishing O vacancies, thereby increasing the instantaneous supply of lattice oxygen to the oxidation of acetone (to H(2)O and CO(2)), which proceeds through an adsorbed acetate intermediate. This work contributes to the development of next-generation sensors, which offer ultrahigh detection capabilities for organic molecules. PMID:22950638
Kaiglová, Jana; Langhammer, Jakub; Ji?inec, Petr; Janský, Bohumír; Chalupová, Dagmar
2015-03-01
This article used various hydrodynamic and sediment transport models to analyze the potential and the limits of different channel schematizations. The main aim was to select and evaluate the most suitable simulation method for fine-grained sediment remobilization assessment. Three types of channel schematization were selected to study the flow potential for remobilizing fine-grained sediment in artificially modified channels. Schematization with a 1D cross-sectional horizontal plan, a 1D+ approach, splitting the riverbed into different functional zones, and full 2D mesh, adopted in MIKE by the DHI modeling suite, was applied to the study. For the case study, a 55-km stretch of the Bílina River, in the Czech Republic, Central Europe, which has been heavily polluted by the chemical and coal mining industry since the mid-twentieth century, was selected. Long-term exposure to direct emissions of toxic pollutants including heavy metals and persistent organic pollutants (POPs) resulted in deposits of pollutants in fine-grained sediments in the riverbed. Simulations, based on three hydrodynamic model schematizations, proved that for events not exceeding the extent of the riverbed profile, the 1D schematization can provide comparable results to a 2D model. The 1D+ schematization can improve accuracy while keeping the benefits of high-speed simulation and low requirements of input DEM data, but the method's suitability is limited by the channel properties. PMID:25687259
Bengoechea, Rocio; Pittman, Sara K; Tuck, Elizabeth P; True, Heather L; Weihl, Conrad C
2015-12-01
Limb-girdle muscular dystrophy type 1D (LGMD1D) is caused by dominantly inherited missense mutations in DNAJB6, an Hsp40 co-chaperone. LGMD1D muscle has rimmed vacuoles and inclusion bodies containing DNAJB6, Z-disc proteins and TDP-43. DNAJB6 is expressed as two isoforms; DNAJB6a and DNAJB6b. Both isoforms contain LGMD1D mutant residues and are expressed in human muscle. To identify which mutant isoform confers disease pathogenesis and generate a mouse model of LGMD1D, we evaluated DNAJB6 expression and localization in skeletal muscle as well as generating DNAJB6 isoform specific expressing transgenic mice. DNAJB6a localized to myonuclei while DNAJB6b was sarcoplasmic. LGMD1D mutations in DNAJB6a or DNAJB6b did not alter this localization in mouse muscle. Transgenic mice expressing the LGMD1D mutant, F93L, in DNAJB6b under a muscle-specific promoter became weak, had early lethality and developed muscle pathology consistent with myopathy after 2 months; whereas mice expressing the same F93L mutation in DNAJB6a or overexpressing DNAJB6a or DNAJB6b wild-type transgenes remained unaffected after 1 year. DNAJB6b localized to the Z-disc and DNAJB6b-F93L expressing mouse muscle had myofibrillar disorganization and desmin inclusions. Consistent with DNAJB6 dysfunction, keratin 8/18, a DNAJB6 client also accumulated in DNAJB6b-F93L expressing mouse muscle. The RNA-binding proteins hnRNPA1 and hnRNPA2/B1 accumulated and co-localized with DNAJB6 at sarcoplasmic stress granules suggesting that these proteins maybe novel DNAJB6b clients. Similarly, hnRNPA1 and hnRNPA2/B1 formed sarcoplasmic aggregates in patients with LGMD1D. Our data support that LGMD1D mutations in DNAJB6 disrupt its sarcoplasmic function suggesting a role for DNAJB6b in Z-disc organization and stress granule kinetics. PMID:26362252
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.
Sandia reactor kinetics codes: SAK and PK1D
International Nuclear Information System (INIS)
The Sandia Kinetics code (SAK) is a one-dimensional coupled thermal-neutronics transient analysis code for use in simulation of reactor transients. The time-dependent cross section routines allow arbitrary time-dependent changes in material properties. The one-dimensional heat transfer routines are for cylindrical geometry and allow arbitrary mesh structure, temperature-dependent thermal properties, radiation treatment, and coolant flow and heat-transfer properties at the surface of a fuel element. The Point Kinetics 1 Dimensional Heat Transfer Code (PK1D) solves the point kinetics equations and has essentially the same heat-transfer treatment as SAK. PK1D can address extended reactor transients with minimal computer execution time
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.
Quantitative 1D saturation profiles on chalk by NMR
DEFF Research Database (Denmark)
Olsen, Dan; Topp, Simon; Stensgaard, Anders; Nørgaard, Jens Vinther; Reffstrup, Jens
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 ...
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.
Dimer impurity effect on the 1D density of states
International Nuclear Information System (INIS)
We study the effect of a dimer impurity on the local density of states (LDOS) associated with 1D tight binding Hamiltonian. Theoretical analysis is carried out by studying the resulting three-term recursion relation corresponding to the tridiagonal representation of the system Hamiltonian. We found a closed form expression for the perturbed LDOS in terms of the unperturbed one with a pre-factor that carries information on both location and potential strength of the dimer impurity.
Dimer impurity effect on the 1D density of states
Energy Technology Data Exchange (ETDEWEB)
Bahlouli, H., E-mail: bahlouli@kfupm.edu.s [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al Zahrani, A. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); El Aaoud, E. [Physics Department, University of Hail (Saudi Arabia); Al-Marzoug, S.M. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)
2010-11-01
We study the effect of a dimer impurity on the local density of states (LDOS) associated with 1D tight binding Hamiltonian. Theoretical analysis is carried out by studying the resulting three-term recursion relation corresponding to the tridiagonal representation of the system Hamiltonian. We found a closed form expression for the perturbed LDOS in terms of the unperturbed one with a pre-factor that carries information on both location and potential strength of the dimer impurity.
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 ...
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...
Pressure Fronts in 1D Damped Nonlinear Lattices
Aubry, S.; Proville, L.
2009-01-01
The propagation of pressure fronts (impact solutions) in 1D chains of atoms coupled by anharmonic potentials between nearest neighbor and submitted to damping forces preserving uniform motion, is investigated. Travelling fronts between two regions at different uniform pressures are found numerically and well approximate analytically. It is proven that there are three analytical relations between the impact velocity, the compression, the front velocity and the energy dissipat...
1D Cahn-Hilliard equation for modulated phase systems
Energy Technology Data Exchange (ETDEWEB)
Villain-Guillot, Simon, E-mail: simon.villain-guillot@u-bordeaux1.f [Centre de Physique Moleculaire Optique et Hertzienne, Universite Bordeaux I, 351 cours de la Liberation 33405 Talence Cedex (France)
2010-05-21
Formation of modulated phase patterns can be modelized by a modified Cahn-Hilliard equation which includes a non-local term preventing the formation of macroscopic domains. Using stationary solutions of the original Cahn-Hilliard equation as analytical ansatzs, we compute the thermodynamically stable period of a 1D modulated phase pattern. We find that the period scales like the power -1/3 of the strength of the long-range interaction.
Lidia B?aszczyk; Barbara Apolinarska; Micha? Kwiatek; Halina Wi?niewska; Monika Langner; Boles?aw P. Salmanowicz
2013-01-01
Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat) genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8). Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) confirmed the 1D/1A chromosome substitution. The presence or...
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)
Investigation of reflood models by coupling REFLA-1D and multi-loop system model
International Nuclear Information System (INIS)
A system analysis code REFLA-1DS was developed by coupling reflood analysis code REFLA-1D and a multi-loop primary system model. The reflood models in the code were investigated for the development of the integral system analysis code. The REFLA-1D, which was developed with the small scale reflood experiment at JAERI, consists of one-dimensional core model and a primary system model with a constant loop resistance. The multi-loop primary system model was developed with the Cylindrical Core Test Facility of JAERI's large scale reflood tests. The components modeled in the code are the upper plenum, the steam generator, the coolant pump, the ECC injection port, the downcomer and the broken cold leg nozzle. The coupling between the two models in REFLA-1DS is accomplished by applying the equivalent flow resistance calculated with the multiloop model to the REFLA-1D. The characteristics of the code is its simplicity of the system model and the solution method which enables the fast running and the easy reflood analysis for the further model development. A fairly good agreement was obtained with the results of the Cylindrical Core Test Facility for the calculated water levels in the downcomer, the core and the upper plenum. A qualitatively good agreement was obtained concerning the parametric effects of the system pressure, the ECC flow rate and the initial clad temperature. Needs for further code improvements of the models, however, were pointed out. These include the problem concerning the generation rate of the steam and water droplets in the core in an early period, the effect of the flow oscillation on the core cooling, the heat release from the downcomer wall, and the stable system calculation. (author)
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
Directory of Open Access Journals (Sweden)
Venkat Ramachandran
2007-09-01
Full Text Available A method for the generation of discrete-domain two-dimensional (2-D transfer functions possessing variable magnitude and contour characteristics is presented in this paper. The proposed method is based upon a configuration constituted by two 1-D filters in cascade and a feedback loop. Each of these 1-D filter is designed to have a monotonic magnitude frequency response. This is obtained by performing one or several integrations, either with respect to ? or ?2, of the denominator of a magnitude Butterworth low-pass frequency response and obtaining the corresponding modified transfer function. The variable characteristics in each domain are obtained by changing a multiplier either in the forward path or in the feedback path of the proposed general configuration. The use of a generalized bilinear transformation (GBT on the transfer functions obtained by the above mentioned method permits the generation of a large number of different characteristics. A certain number of these characteristics is examined in some detail. Illustrative examples are provided.
Coupling of Nod1D and HOTCHANNEL: static case; Acoplamiento de Nod1D y HOTCHANNEL: caso estatico
Energy Technology Data Exchange (ETDEWEB)
Gomez T, A.M. [IPN-ESFM, 07738 Mexico D.F. (Mexico); Ovando C, R. [IIE-Gcia. de Energia Nuclear, Cuernavaca, Morelos (Mexico)]. e-mail: rovando@iie.org.mx
2003-07-01
In this work the joining of the programs Nod1D and HOTCHANNEL, developed in the National Polytechnic Institute (IPN) and in the Electrical Research Institute (IIE) respectively is described. The first one allows to study the neutronic of a nuclear reactor and the second one allows to carry out the analysis of hot channel of a Boiling Water Reactor (BWR). Nod1 D is a program that it solves by nodal methods type finite element those diffusion equations in multigroup, and it is the static part of Nod Kin that it solves the diffusion equation in their time dependent part. For another side HOTCHANNEL is based on a mathematical model constituted by four conservation equations (two of mass conservation, one of motion quantity and one of energy), which are solved applying one discretization in implicit finite differences. Both programs have been verified in independent form using diverse test problems. In this work the modifications that were necessary to carry out to both for obtaining a coupled program that it provides the axial distribution of the neutron flux, the power, the burnup and the void fraction, among others parameters as much as neutronic as thermal hydraulics are described. Those are also mentioned limitations, advantages and disadvantages of the final product to which has been designated Nod1 D-HotChn. Diverse results for the Cycle 1 of the Laguna Verde Unit 1 reactor of the Nucleo electric central comparing them with those obtained directly with the CoreMasterPresto code are provided. (Author)
1D nonnegative Schrodinger operators with point interactions
Yu. G. Kovalev
2013-01-01
Let $Y$ be an infinite discrete set of points in $dR$,satisfying the condition $inf{|y-y'|,; y,y'in Y, y'ey}>0.$ In the paper we prove that the systems${delta(x-y)}_{yin Y}, ;{delta'(x-y)}_{yin Y},{delta(x-y),;delta'(x-y)}_{yin Y}$ {form Riesz} bases in the corresponding closed linear spans in the Sobolev spaces $W_2^{-1}(dR)$ and $W_2^{-2}(dR)$. As an application, we prove the transversalness of the Friedrichs and Kreui n nonnegative selfadjoint extensions of the nonnegative symmetric operat...
Extended electronic states in disordered 1-d lattices an example
Sil, S; Moitra, R K
1993-01-01
We discuss a very simple model of a 1-d disordered lattice, in which {\\em all} the electronic eigenstates are extended. The nature of these states is examined from several viewpoints, and it is found that the eigenfunctions are not Bloch functions although they extend throughout the chain. Some typical wavefunctions are plotted. This problem originated in our earlier study of extended states in the quasiperiodic copper-mean lattice [ Sil, Karmakar, Moitra and Chakrabarti, Phys. Rev. B (1993) ]. In the present investigation extended states are found to arise from a different kind of correlation than that of the well-known dimer-type.
Spectral function of the 1D Hubbard model
International Nuclear Information System (INIS)
For the one-dimensional (1D) Hubbard model, we extended the bosonization technique, away from half filling, in such a way that a general formula is obtained for the zero temperature equal-time single-particle Green function with validity over the whole doping range. With our method, we can calculate, for the first time, the one-body Green function and thus, the spectral function in both the Tomonaga-Luttinger and Luther-Emery universality classes. The method also gives a tool to determine the coefficients of the correlation functions which cannot be determined with previously used methods. ((orig.))
1D models for condensation induced water hammer in pipelines
International Nuclear Information System (INIS)
Condensation induced water hammer (CIWH) are caused by contact of steam and subcooled water. Thus, modeling the direct contact condensation is a crucial step towards the simulation of condensation induced water hammer with 1D pressure surge codes. Therefore, also the TUeV NORD SysTec GmbH and Co. KG inhouse pressure surge code DYVRO has been equipped with a new contact condensation model. The validation of DYVRO against an experiment dealing with CIWH is presented in this contribution. (orig.)
Interaction-induced conducting-nonconducting transition of ultra-cold atoms in 1D optical lattices
Chien, Chih-Chun; Gruss, Daniel; Di Ventra, Massimiliano; Zwolak, Michael
2012-01-01
The study of time-dependent, many-body transport phenomena is increasingly within reach of ultra-cold atom experiments. We show that the introduction of spatially inhomogeneous interactions, e.g., generated by optically-controlled collisions, induce negative differential conductance in the transport of atoms in 1D optical lattices. Specifically, we simulate the dynamics of interacting fermionic atoms via a micro-canonical transport formalism within both mean-field and a high...
The photo-induced reaction of digermane with the Si(100)(2 × 1):D surface
Isobe, Chiharu; Cho, Hee-Chuen; Crowell, John E.
1993-09-01
Photo-induced surface reactions brought about by photolysis of adsorbed digermane on the Si(100)(2 × 1):D surface have been investigated under ultrahigh vacuum conditions using Auger electron spectroscopy and temperature programmed desorption. On the monodeuterated Si(100)(2 × 1):D surface, no spontaneous thermal reaction of digermane is observed, due to the termination of the dangling bonds with D atoms. Molecular Ge 2H 6, weakly adsorbed on Si(100)(2 × 1):D at 120 K, dissociates upon UV irradiation, leading to the incorporation of Ge atoms and the adsorption of H atoms on the surface. The appearance of a new low temperature ? desorption state for hydrogen (deuterium) desorption near 580 K is further evidence for Ge deposition and the photo-induced decomposition of physi-adsorbed Ge 2H 6. The observation of ?-HD and ?-D 2 desorption indicates that the photoreaction intermediate inserts into the surface Si-D bond to produce a Ge-D bond. Studies of the thermal reaction of Ge 2H 6 with partially deuterated (? D < 1.0) Si(100) surfaces model the chemistry expected for a germyl radical intermediate, and illustrate that the germyl radical does not give rise to the observed surface photochemistry. The enhanced production of Ge trihydride (deuteride) species with increasing UV exposure, as measured by the GeH xD 4- x desorption yield, coupled with the observation of Ge-D bond formation, reveals that the photo-induced Ge 2H 6 surface reaction is dominated by an insertion reaction into surface hydride (deuteride) bonds by the photo-generated species germylene.
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 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...
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.
Engineered atom-light interactions in 1D photonic crystals
Martin, Michael J.; Hung, Chen-Lung; Yu, Su-Peng; Goban, Akihisa; Muniz, Juan A.; Hood, Jonathan D.; Norte, Richard; McClung, Andrew C.; Meenehan, Sean M.; Cohen, Justin D.; Lee, Jae Hoon; Peng, Lucas; Painter, Oskar; Kimble, H. Jeff
2014-05-01
Nano- and microscale optical systems offer efficient and scalable quantum interfaces through enhanced atom-field coupling in both resonators and continuous waveguides. Beyond these conventional topologies, new opportunities emerge from the integration of ultracold atomic systems with nanoscale photonic crystals. One-dimensional photonic crystal waveguides can be engineered for both stable trapping configurations and strong atom-photon interactions, enabling novel cavity QED and quantum many-body systems, as well as distributed quantum networks. We present the experimental realization of such a nanophotonic quantum interface based on a nanoscale photonic crystal waveguide, demonstrating a fractional waveguide coupling of ?1 D /?' of 0 . 32 +/- 0 . 08 , where ?1 D (?') is the atomic emission rate into the guided (all other) mode(s). We also discuss progress towards intra-waveguide trapping of ultracold Cs. This work was supported by the IQIM, an NSF Physics Frontiers Center with support from the Moore Foundation, the DARPA ORCHID program, the AFOSR QuMPASS MURI, the DoD NSSEFF program, NSF, and the Kavli Nanoscience Institute (KNI) at Caltech.
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.
Crossed molecular beams study of O({sup 1}D) reactions with H{sub 2} molecules
Energy Technology Data Exchange (ETDEWEB)
Miau, T.T.
1995-05-01
Reaction dynamics of O({sup 1}D) atoms with H{sub 2} molecules was reinvestigated using the crossed molecular beams technique with pulsed beams. The O({sup 1}D) beam was generated by photodissociating O{sub 3} molecules at 248 nm. Time-of-flight spectra and the laboratory angular distribution of the OH products were measured. The derived OH product center-of-mass flux-velocity contour diagram shows more backward scattered intensity with respect to the O({sup 1}D) beam. In contrast to previous studies which show that the insertion mechanism is the dominant process, our results indicate that the contribution from the collinear approach of the O({sup 1}D) atom to the H{sub 2} molecule on the first excited state potential energy surface is significant and the energy barrier for the collinear approach is therefore minimal. Despite the increased time resolution in this experiment, no vibrational structure in the OH product time-of-flight spectra was resolved. This is in agreement with LIF studies, which have shown that the rotational distributions of the OH products in all vibrational states are broad and highly inverted.
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.
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 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 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.
PALLAS-1D(VII), Direct Integration of Transport Equation in 1-D Planar and Spherical Geometry
International Nuclear Information System (INIS)
1 - Description of program or function: PALLAS-1D(VII) solves the steady state Boltzmann transport equation in one dimensional plan and spherical geometries for fixed source problems. It can also solve the transport of secondary gamma rays such as Bremsstrahlung and annihilation photons. 2 - Method of solution: The method of direct integration of the transport equation is used, in which the equation is integrated along the flight path of radiation in the direction of motion at each discrete ordinate direction. Anisotropic scattering is treated precisely using differential scattering cross sections for elastic scattering; however, isotropic scattering in the laboratory system is assumed in inelastic scattering of neutron. No iteration and convergence techniques are used for obtaining the flux. Energy dependence is treated by the multigroup approximation. 3 - Restrictions on the complexity of the problem: PALLAS-1D(VII) has been written in the fixed dimensioning, which restricts the numbers of energy meshes, material regions, nuclides, angular meshes, spatial meshes to be input
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.
Magnetism in 1D Cobalt-Cyclopentadienyl Sandwich Molecular Wire
Allmaier, Hannes; Morari, C.; Chioncel, L.; Arrigoni, E.; Beiuseanu, F.; Lichtenstein, A.; Katsnelson, M.
2009-03-01
A challenge for technological applications at the nanometer scale is to find magnetic materials with reduced dimensionality. Recent theoretical studies have predicted ferromagnetic and half-metallic behavior for the 1D-organometallic benzen vanadium wire. Here we discuss a variety of magnetic orderings such as anti-ferromagnetic and ferrimagnetic half-metallicity in the cobaltocen Co2(C5H5)2 nanowire. We performed DFT-calculations to optimize its geometry and used the NMTO downfolding technique to construct the real-space low energy Hamiltonian. To describe electronic correlations beyond the mean-field, we used the developed Variational Cluster Approach. Our preliminary results show that non-quasiparticle states appear in the half-metallic gap, which reduce considerably the spin polarization of such a wire. Ab-initio electron transport calculations are in progress to establish the role of cobaltocen nanowire as part of a future spin filter.
Neutral excitations in quasi-1D strongly correlated electron systems
International Nuclear Information System (INIS)
Novel neutral spin-0 excitation for quasi-1D systems with one electron per site are obtained within a localized scheme. Our ground state wave-function is defined by a variational localized - site cluster - expanded ansatz and these excitations are naturally built upon it. All computations are easily carried out by a transfer matrix technique that enables explicit inclusion of electron - correlation effects and, at the same time, provides a quasi - particle band - theoretic picture of these excitations. This treatment is applied, in particular, to a polyphene strip. At k=0 the energy gap corresponds to a dipole-allowed transition in the visible region, our result compares fairly well with observed decreasing transitions for finite polyphene strips. (author). 14 refs, 1 fig
Evidence against dopamine D1/D2 receptor heteromers.
Frederick, A L; Yano, H; Trifilieff, P; Vishwasrao, H D; Biezonski, D; Mészáros, J; Urizar, E; Sibley, D R; Kellendonk, C; Sonntag, K C; Graham, D L; Colbran, R J; Stanwood, G D; Javitch, J A
2015-11-01
Hetero-oligomers of G-protein-coupled receptors have become the subject of intense investigation, because their purported potential to manifest signaling and pharmacological properties that differ from the component receptors makes them highly attractive for the development of more selective pharmacological treatments. In particular, dopamine D1 and D2 receptors have been proposed to form hetero-oligomers that couple to G?q proteins, and SKF83959 has been proposed to act as a biased agonist that selectively engages these receptor complexes to activate G?q and thus phospholipase C. D1/D2 heteromers have been proposed as relevant to the pathophysiology and treatment of depression and schizophrenia. We used in vitro bioluminescence resonance energy transfer, ex vivo analyses of receptor localization and proximity in brain slices, and behavioral assays in mice to characterize signaling from these putative dimers/oligomers. We were unable to detect G?q or G?11 protein coupling to homomers or heteromers of D1 or D2 receptors using a variety of biosensors. SKF83959-induced locomotor and grooming behaviors were eliminated in D1 receptor knockout (KO) mice, verifying a key role for D1-like receptor activation. In contrast, SKF83959-induced motor responses were intact in D2 receptor and G?q KO mice, as well as in knock-in mice expressing a mutant Ala(286)-CaMKII? that cannot autophosphorylate to become active. Moreover, we found that, in the shell of the nucleus accumbens, even in neurons in which D1 and D2 receptor promoters are both active, the receptor proteins are segregated and do not form complexes. These data are not compatible with SKF83959 signaling through G?q or through a D1/D2 heteromer and challenge the existence of such a signaling complex in the adult animals that we used for our studies. PMID:25560761
DEFF Research Database (Denmark)
Treebak, Jonas Thue; Pehmøller, Christian; Kristensen, Jonas Møller; Kjøbsted, Rasmus; Birk, Jesper Bratz; Schjerling, Peter; Richter, Erik; Goodyear, Laurie J; Wojtaszewski, Jørgen
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), t...
Comparing plasma fluid models of different order for 1D streamer ionization fronts
Markosyan, Aram H.; Teunissen, Jannis; Dujko, Saša; Ebert, Ute
2015-12-01
We evaluate the performance of three plasma fluid models: the first order reaction-drift-diffusion model based on the local field approximation; the second order reaction-drift-diffusion model based on the local energy approximation and a recently developed high order fluid model by Dujko et al (2013 J. Phys. D 46 475202) We first review the fluid models: we briefly discuss their derivation, their underlying assumptions and the type of transport data they require. Then we compare these models to a particle-in-cell/Monte Carlo (PIC/MC) code, using a 1D test problem. The tests are performed in neon and nitrogen at standard temperature and pressure, over a wide range of reduced electric fields. For the fluid models, transport data generated by a multi-term Boltzmann solver are used. We analyze the observed differences in the model predictions and address some of the practical aspects when using these plasma fluid models.
A first-principles study on quasi-1D alkali metal chains within zeolite channels
Li, Zhenyu; Yang, Jinlong; Hou, J. G.; Zhu, Qingshi
2004-05-01
We report first-principles studies on systems formed by alkali metal (Na, K, or Rb) added to zeolite ITQ-4. Geometric and electronic structures of the quasi-1D chains of intercalated alkali metal atoms at experimental loading (4 metal atoms per 32 Si) are studied. Clear differences between different kinds of alkali metal are found, with a general trend of decreased ionization and less metallic character for the lighter alkali metals. Within the zeolite channels, it is possible to form insulated and metallic alkali metal chains by doping Na or Rb. Agreeing with experiments, only Rb here is found to be a good candidate to generate inorganic electride. We also predict that a large quantity of Na can be doped into the zeolite channel, while no more than 4 Rb per 16 Si can be doped.
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.
Uno, Yasuhiro; Uehara, Shotaro; Yamazaki, Hiroshi
2011-01-01
The cytochrome P450 (CYP) 1 family consists of the CYP1A, CYP1B, CYP1C, and CYP1D subfamilies. In humans, CYP1A1, CYP1A2, and CYP1B1 are expressed and encode functional enzymes, whereas CYP1D1P (formerly known as CYP1A8P) is present as a pseudogene as a result of five nonsense mutations in exon 2 and exon 7 of the putative coding region. We previously identified CYP1D1 in macaques and found that it was expressed and functional in liver. Moreover, the nonsense mutations in exon 2 and exon 7 were not found in the 20 cynomolgus macaques and 10 rhesus macaques analyzed in that previous study. These results raised the possibility that CYP1D1 is a functional gene in macaques; however, the possibility that nonsense mutations are present in other exons cannot be excluded. In this study, we sought to identify genetic variants of CYP1D1 in 63 cynomolgus macaques and 30 rhesus macaques; we did not find nonsense mutations in any coding exon of the animals analyzed. Moreover, 15 of the 63 cynomolgus macaques were analyzed by quantitative polymerase chain reaction, confirming hepatic expression of CYP1D1 in all 15 animals. These results suggest that CYP1D1 is most likely functional in cynomolgus macaques and rhesus macaques. PMID:21844658
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...
DEFF Research Database (Denmark)
Brorsson, C.; Hansen, Niclas Tue
2009-01-01
To develop novel methods for identifying new genes that contribute to the risk of developing type 1 diabetes within the Major Histocompatibility Complex (MHC) region on chromosome 6, independently of the known linkage disequilibrium (LD) between human leucocyte antigen (HLA)-DRB1, -DQA1, -DQB1 genes. We have developed a novel method that combines single nucleotide polymorphism (SNP) genotyping data with protein-protein interaction (ppi) networks to identify disease-associated network modules enriched for proteins encoded from the MHC region. Approximately 2500 SNPs located in the 4 Mb MHC region were analysed in 1000 affected offspring trios generated by the Type 1 Diabetes Genetics Consortium (T1DGC). The most associated SNP in each gene was chosen and genes were mapped to ppi networks for identification of interaction partners. The association testing and resulting interacting protein modules were statistically evaluated using permutation. A total of 151 genes could be mapped to nodes within the protein interaction network and their interaction partners were identified. Five protein interaction modules reached statistical significance using this approach. The identified proteins are well known in the pathogenesis of T1D, but the modules also contain additional candidates that have been implicated in beta-cell development and diabetic complications. The extensive LD within the MHC region makes it important to develop new methods for analysing genotyping data for identification of additional risk genes for T1D. Combining genetic data with knowledge about functional pathways provides new insight into mechanisms underlying T1D.
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.
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.
From Domain Wall to Overlap in 2+1d
Hands, Simon
2015-01-01
The equivalence of domain wall and overlap fermion formulations is demonstrated for lattice gauge theories in 2+1 spacetime dimensions with parity-invariant mass terms. Even though the domain wall approach distinguishes propagation along a third direction with projectors ${1\\over2}(1\\pm\\gamma_3)$, the truncated overlap operator obtained for finite wall separation $L_s$ is invariant under interchange of $\\gamma_3$ and $\\gamma_5$. In the limit $L_s\\to\\infty$ the resulting Ginsparg-Wilson relations recover the expected U($2N_f$) global symmetry up to O($a$) corrections. Finally it is shown that finite-$L_s$ corrections to bilinear condensates associated with dynamical mass generation are characterised by whether even powers of the symmetry-breaking mass are present; such terms are absent for antihermitian bilinears such as $i\\bar\\psi\\gamma_3\\psi$, markedly improving the approach to the large-$L_s$ limit.
1D Schroedinger equation with open boundaries for pumping potentials
Energy Technology Data Exchange (ETDEWEB)
Rohling, Niklas; Grossmann, Frank [Institut fuer Theoretische Physik, Technische Universitaet Dresden, D-01062 Dresden (Germany)
2011-07-01
In order to generate a non-vanishing average current within the time-periodic Schroedinger equation the potential has to break parity and generalized parity. We therefore firstly consider the following potentials with position-dependence only in a central region and a non-static bias: a harmonically driven sawtooth potential (a) and a step-like potential (b). Secondly, we study a dipole field in the central region (c). The cases (b) and (c) contain driving by the fundamental and the second harmonic, so-called harmonic mixing. To calculate the current, we use Floquet scattering theory as well as an open boundary wavefunction. In case (c) we optimize the relative amplitude ratio between the fundamental and the second harmonic leading to a maximum in the pumping current.
Surface roughened 1-D Au host nanorods for visible light induced photocatalyst
International Nuclear Information System (INIS)
Highlights: • Surface roughened 1-D Au host nanorods for visible light induced photocatalyst are tried. • A nanofilm of hematite coated on high conducting and vertically aligned smooth Au nanorods or nanoporous Au nanorods is prepared. • We report an effect of surface morphology of Au nanorods on the photoactivity of hematite/gold nanorod arrays prepared by the electrodeposition method. -- Abstract: Visible light induced photocatalytic degradation of rhodamine B and hydrogen generation from solar water splitting by hematite (?-Fe2O3) coated gold (Au) nanorods have been investigated, in which two types of ?-Fe2O3/Au nanorods with different Au surfaces were synthesized and then carefully compared. Vertically aligned smooth Au nanorod and porous Au nanorod arrays were prepared by the electro-deposition method using anodized aluminum oxide templates, followed by deposition of hematite onto nanoporous Au nanorods and smooth Au nanorods to synthesize core/shell like nanostructure. The as-prepared samples were characterized by Field Emission Scanning Electron Microscopy, X-ray Diffraction, and X-ray Photoelectron Spectroscopy. Also, their photocatalytic activities were investigated by photo-degradation of rhodamine B, photocurrent–voltage, and incident photon to current conversion efficiency measurements under AM 1.5G light irradiation. Hematite (?-Fe2O3) coated porous Au nanorods showed better photocatalytic activities than ?-Fe2O3 coated smooth Au nanorods, showing faster dye degradation rate, higher photocurrent density and better photon harvesting
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
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...
The role of river flow and tidal asymmetry on 1-D estuarine morphodynamics
Guo, L.; Wegen, M.; Roelvink, J. A.; He, Q.
2014-11-01
Numerous research efforts have been devoted to understanding estuarine morphodynamics under tidal forcing. However, the impact of river discharge on estuarine morphodynamics is insufficiently examined. Inspired by the Yangtze Estuary, this work explores the morphodynamic impact of river discharge in a 560 km long tidal basin based on a 1-D model (Delft3D). The model considers total load sediment transport and employs a morphodynamic updating scheme to achieve long-term morphodynamic evolution. We analyze the role of Stokes drift, tidal asymmetry, and river discharge in generating tidal residual sediment transport. Model results suggest that morphodynamic equilibrium is approached within millennia by vanishing spatial gradients of tidal residual sediment transport. We find that the interaction between ebb-directed Stokes return flow/river flow with tides is an important mechanism that flushes river-supplied sediment seaward. Increasing river discharge does not induce continuously eroded or accreted equilibrium bed profiles because of the balance between riverine sediment supply and sediment flushing to the sea. An intermediate threshold river discharge can be defined which leads to a deepest equilibrium bed profile. As a result, the shape (concavity or convexity) of the equilibrium bed profiles will adapt with the magnitude of river discharge. Overall, this study reveals the significant role of river discharge in controlling estuarine morphodynamics by supplying sediment and reinforcing ebb-directed residual sediment transport.
Improving Selectivity of 1D Bragg Resonator Using Coupling of Propagating and Trapped Waves
Ginzburg, N S; Peskov, Nikolay Yu; Sergeev, A S
2004-01-01
A novel 1D Bragg resonator based on coupling propagated and locked (quasi cut-off) modes should be tested in a JINR- IAP FEM-oscillator to improve selectivity over the transverse mode index. In this scheme the electron beam interacts with only propagating wave, and the latter is coupled with a quasi cut-off mode. This coupling can be realized by either helical or azimuthally-symmetric corrugation. The quasi cut-off mode provides the feedback in the system leading to the absolute instability and the self-excitation of the whole system while efficiency in the steady-state regime of generation is almost completely determined by the propagating mode, synchronous to the beam. Analytical consideration and numerical simulation show that the efficiency of such an FEM can be rather high. The main advantage of this scheme is provision of higher selectivity over the transverse mode index than traditional scheme of Bragg FEL that encourage increasing operating frequency for fixed transverse size of the interaction space.
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
2015-09-28
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.
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.
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
Ishii, Hiroshi; Asai, Yasuhiro
2015-12-01
Although precursory signs of an earthquake can occur before the event, it is difficult to observe such signs with precision, especially on earth's surface where artificial noise and other factors complicate signal detection. One possible solution to this problem is to install monitoring instruments into the deep bedrock where earthquakes are likely to begin. When evaluating earthquake occurrence, it is necessary to elucidate the processes of stress accumulation in a medium and then release as a fault (crack) is generated, and to do so, the stress must be observed continuously. However, continuous observations of stress have not been implemented yet for earthquake monitoring programs. Strain is a secondary physical quantity whose variation varies depending on the elastic coefficient of the medium, and it can yield potentially valuable information as well. This article describes the development of a borehole stress meter that is capable of recording both continuous stress and strain at a depth of about 1 km. Specifically, this paper introduces the design principles of the stress meter as well as its actual structure. It also describes a newly developed calibration procedure and the results obtained to date for stress and strain studies of deep boreholes at three locations in Japan. To show examples of the observations, records of stress seismic waveforms generated by the 2011 Tohoku earthquake ( M 9.0) are presented. The results demonstrate that the stress meter data have sufficient precision and reliability.
Tctex1d2 Is a Negative Regulator of GLUT4 Translocation and Glucose Uptake.
Shimoda, Yoko; Okada, Shuichi; Yamada, Eijiro; Pessin, Jeffrey E; Yamada, Masanobu
2015-10-01
Tctex1d2 (Tctex1 domain containing 2) is an open reading frame that encodes for a functionally unknown protein that contains a Tctex1 domain found in dynein light chain family members. Examination of gene expression during adipogenesis demonstrated a marked increase in Tctex1d2 protein expression that was essentially undetectable in preadipocytes and markedly induced during 3T3-L1 adipocyte differentiation. Tctex1d2 overexpression significantly inhibited insulin-stimulated glucose transporter 4 (GLUT4) translocation and 2-deoxyglucose uptake. In contrast, Tctex1d2 knockdown significantly increased insulin-stimulated GLUT4 translocation and 2-deoxyglucose uptake. However, acute insulin stimulation (up to 30 min) in 3T3-L1 adipocytes with overexpression or knockdown of Tctex1d2 had no effect on Akt phosphorylation, a critical signal transduction target required for GLUT4 translocation. Although overexpression of Tctex1d2 had no significant effect on GLUT4 internalization, Tctex1d2 was found to associate with syntaxin 4 in an insulin-dependent manner and inhibit Doc2b binding to syntaxin 4. In addition, glucose-dependent insulinotropic polypeptide rescued the Tctex1d2 inhibition of insulin-stimulated GLUT4 translocation by suppressing the Tctex1d2-syntaxin 4 interaction and increasing Doc2b-Synatxin4 interactions. Taking these results together, we hypothesized that Tctex1d2 is a novel syntaxin 4 binding protein that functions as a negative regulator of GLUT4 plasma membrane translocation through inhibition of the Doc2b-syntaxin 4 interaction. PMID:26200093
Control oriented 1D electrochemical model of lithium ion battery
International Nuclear Information System (INIS)
Lithium ion (Li-ion) batteries provide high energy and power density energy storage for diverse applications ranging from cell phones to hybrid electric vehicles (HEVs). For efficient and reliable systems integration, low order dynamic battery models are needed. This paper introduces a general method to generate numerically a fully observable/controllable state variable model from electrochemical kinetic, species and charge partial differential equations that govern the discharge/charge behavior of a Li-ion battery. Validated against a 313th order nonlinear CFD model of a 6 Ah HEV cell, a 12th order state variable model predicts terminal voltage to within 1% for pulse and constant current profiles at rates up to 50 C. The state equation is constructed in modal form with constant negative real eigenvalues distributed in frequency space from 0 to 10 Hz. Open circuit potential, electrode surface concentration/reaction distribution coupling and electrolyte concentration/ionic conductivity nonlinearities are explicitly approximated in the model output equation on a local, electrode-averaged and distributed basis, respectively. The balanced realization controllability/observability gramian indicates that the fast electrode surface concentration dynamics are more observable/controllable than the electrode bulk concentration dynamics (i.e. state of charge)
Comparison of 1D and 2D modelling with soil erosion model SMODERP
Kavka, Petr; Weyskrabova, Lenka; Zajicek, Jan
2013-04-01
The contribution presents a comparison of a runoff simulated by profile method (1D) and spatially distributed method (2D). Simulation model SMODERP is used for calculation and prediction of soil erosion and surface runoff from agricultural land. SMODERP is physically based model that includes the processes of infiltration (Phillips equation), surface runoff (kinematic wave based equation), surface retention, surface roughness and vegetation impact on runoff. 1D model was developed in past, new 2D model was developed in last two years. The model is being developed at the Department of Irrigation, Drainage and Landscape Engineering, Civil Engineering Faculty, CTU in Prague. 2D model was developed as a tool for widespread GIS software ArcGIS. The physical relations were implemented through Python script. This script uses ArcGIS system tools for raster and vectors treatment of the inputs. Flow direction is calculated by Steepest Descent algorithm in the preliminary version of 2D model. More advanced multiple flow algorithm is planned in the next version. Spatially distributed models enable to estimate not only surface runoff but also flow in the rills. Surface runoff is described in the model by kinematic wave equation. Equation uses Manning roughness coefficient for surface runoff. Parameters for five different soil textures were calibrated on the set of forty measurements performed on the laboratory rainfall simulator. For modelling of the rills a specific sub model was created. This sub model uses Manning formula for flow estimation. Numerical stability of the model is solved by Courant criterion. Spatial scale is fixed. Time step is dynamically changed depending on how flow is generated and developed. SMODERP is meant to be used not only for the research purposes, but mainly for the engineering practice. We also present how the input data can be obtained based on available resources (soil maps and data, land use, terrain models, field research, etc.) and how can the model be used in the assessments of soil erosion risk and in designing of erosion control measures. The research has been supported by the research grants SGS SGS11/148/OHK1/3T/11 "Experimental Research on Rainfall-runoff and Erosion Processes" and by Project No. TA02020647 " Atlas EROZE - a modern tool for soil erosion assessment".
International Nuclear Information System (INIS)
Organic anion transporting polypeptides (rodent Oatp; human OATP) mediate cellular uptake of numerous organic compounds including xenobiotic toxins into mammalian hepatocytes. In the little skate Leucoraja erinacea a liver-specific Oatp (Oatp1d1, also called sOatp) has been identified and suggested to represent an evolutionarily ancient precursor of the mammalian liver OATP1B1 (human), Oatp1b2 (rat), and OATP1B3 (human). The present study tested whether Oatp1d1 shares functional transport activity of the xenobiotic oligopeptide toxins phalloidin and microcystin with the mammalian liver Oatps/OATPs. The phalloidin analogue [3H]-demethylphalloin was taken up into skate hepatocytes with high affinity (Km ? 0.4 ?M), and uptake could be inhibited by phalloidin and a variety of typical Oatp/OATP substrates such as bromosulfophthalein, bile salts, estrone-3-sulfate, cyclosporine A and high concentrations of microcystin-LR (Ki ? 150 ?M). When expressed in Xenopus laevis oocytes Oatp1d1 increased uptake of demethylphalloin (Km ? 2.2 ?M) and microcystin-LR (Km ? 27 ?M) 2- to 3-fold over water-injected oocytes, whereas the alternative skate liver organic anion transporter, the dimeric Ost?/?, exhibited no phalloidin and only minor microcystin-LR transport. Also, the closest mammalian Oatp1d1 orthologue, the human brain and testis OATP1C1, did not show any phalloidin transport activity. These results demonstrate that the evolutionarily ancient Oatp1d1 is able to mediate uptake of cyclic oligopeptide toxins into skate liver. The findings support the notion that Oatp1d1 is a precursor of the liver-specific mammalian Oatps/OATPs and that its transport properties are closely associated with certain forms of toxic liver injury such as for example protein phosphatase inhibition by the water-borne toxin microcystin
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.
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.
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
Energy Technology Data Exchange (ETDEWEB)
Sandusky, Peter [Eckerd College, Department of Chemistry (United States); Appiah-Amponsah, Emmanuel; Raftery, Daniel, E-mail: raftery@purdue.edu [Purdue University, Department of Chemistry (United States)
2011-04-15
One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.
The FC-1D: The profitable alternative Flying Circus Commercial Aviation Group
Meza, Victor J.; Alvarez, Jaime; Harrington, Brook; Lujan, Michael A.; Mitlyng, David; Saroughian, Andy; Silva, Alex; Teale, Tim
1994-01-01
The FC-1D was designed as an advanced solution for a low cost commercial transport meeting or exceeding all of the 1993/1994 AIAA/Lockheed request for proposal requirements. The driving philosophy behind the design of the FC-1D was the reduction of airline direct operating costs. Every effort was made during the design process to have the customer in mind. The Flying Circus Commercial Aviation Group targeted reductions in drag, fuel consumption, manufacturing costs, and maintenance costs. Flying Circus emphasized cost reduction throughout the entire design program. Drag reduction was achieved by implementation of the aft nacelle wing configuration to reduce cruise drag and increase cruise speeds. To reduce induced drag, rather than increasing the wing span of the FC-1D, spiroids were included in the efficient wing design. Profile and friction drag are reduced by using riblets in place of paint around the fuselage and empennage of the FC-1D. Choosing a single aisle configuration enabled the Flying Circus to optimize the fuselage diameter. Thus, reducing fuselage drag while gaining high structural efficiency. To further reduce fuel consumption a weight reduction program was conducted through the use of composite materials. An additional quality of the FC-1D is its design for low cost manufacturing and assembly. As a result of this design attribute, the FC-1D will have fewer parts which reduces weight as well as maintenance and assembly costs. The FC-1D is affordable and effective, the apex of commercial transport design.
Nuclear Oxidation of a Major Peroxidation DNA Adduct, M1dG, in the Genome.
Wauchope, Orrette R; Beavers, William N; Galligan, James J; Mitchener, Michelle M; Kingsley, Philip J; Marnett, Lawrence J
2015-12-21
Chronic inflammation results in increased production of reactive oxygen species (ROS), which can oxidize cellular molecules including lipids and DNA. Our laboratory has shown that 3-(2-deoxy-?-d-erythro-pentofuranosyl)pyrimido[1,2-?]purin-10(3H)-one (M1dG) is the most abundant DNA adduct formed from the lipid peroxidation product, malondialdehyde, or the DNA peroxidation product, base propenal. M1dG is mutagenic in bacterial and mammalian cells and is repaired via the nucleotide excision repair system. Here, we report that M1dG levels in intact DNA were increased from basal levels of 1 adduct per 10(8) nucleotides to 2 adducts per 10(6) nucleotides following adenine propenal treatment of RKO, HEK293, or HepG2 cells. We also found that M1dG in genomic DNA was oxidized in a time-dependent fashion to a single product, 6-oxo-M1dG (to ?5 adducts per 10(7) nucleotides), and that this oxidation correlated with a decline in M1dG levels. Investigations in RAW264.7 macrophages indicate the presence of high basal levels of M1dG (1 adduct per 10(6) nucleotides) and the endogenous formation of 6-oxo-M1dG. This is the first report of the production of 6-oxo-M1dG in genomic DNA in intact cells, and it has significant implications for understanding the role of inflammation in DNA damage, mutagenesis, and repair. PMID:26469224
Synthesis and Electron Field-Emission of 1-D Carbon-Related Nanostructured Materials
Shih, Han C.
2002-10-01
Carbon nanotubes, a new stable form of carbon that was first identified in 1991 [1], are fullerene-related structures which consist of graphitic cylinders closed at either end with caps containing pentagonal rings. Although carbon nanotube structures are closely related to graphite, the curvature, symmetry and small size induce marked deviations from the graphitic behavior. Various methods have been used to produce carbon nanotubes, e.g., arc-discharge, laser-vaporization, catalytic chemical vapor deposition, but too many impurities also be produced, such as fullerenes, carbon nanoparticles and amorphous carbons. The microwave plasma enhanced chemical vapor deposition (MPECVD) system has been used to grow carbon nanotubes in this work and other 1-D carbon-related nanostructured materials was synthesized by the electron cyclotron resonance (ECR) plasma system. Plasma is generated by microwave excitation at 2.45 GHz by a magnetron passes through a waveguide and fed perpendicularly through a quartz dome into an 875 G magnetic field generated by the coils surrounding the resonance volume that creates the ECR condition. The deposition chamber was pumped down to the base pressure of 6.7X10-4 Pa (5X10-6 Torr) with a turbomolecular pump for ECR-plasma and subatmospheric pressures for MPECVD by a rotary mechanical pump. Well-aligned carbon-related nanostructures have been synthesized in nanoporous alumina or silicon with a uniform diameter of 30-100 nm by microwave excited plasma of CH_4, C_2H_2, N_2, H2 and Ar precursors. Nickel nanowires not only serve as catalysts to decompose hydrocarbons to form nanostructures but also function as an electrical conductor for other advanced applications. A negative dc bias is always applied to the substrate to promote the flow of ion fluxes through the nanochannels of the template materials that facilitate the physical adsorption and subsequent chemical absorption in the formation of carbon- and carbon-nitride nanotubes[2]. The electron field emission characteristics of the 1-D carbon-related nanostructures were measured by the conventional diode method at an ambient pressure of 1.3X10-3 Pa (10-5 Torr). The films (1X1-cm^2) were separated from the anode by ITO (indium tin oxide) coated glass, where a glass fiber spacer was maintained at 150 ?m from the cathode. The current density and electric field characteristics were measured using a Keithley 237 electrometer. A range of onset electron emission field from 3.5 to 1.5 V/?m and an emission current density up to 1 mA/cm^2 at 3V/?m have been achieved in this study, apparently superior to other carbon-based electron field emitters[3]. The results were reproducible over a period of weeks and the nanotubes did not degrade physically when exposing to a humid air of RH 90using the Fowler-Nordheim model, I=aV^2 exp (-b?_e^3/2/V) , where a and b are constants. The turn-on voltage was estimated as the voltage deviating from ln(I/V^2)-1/V curve. The effective work function (?_e=?/?) of the arrayed carbon nanotubes was calculated from the slope of the Fowler-Nordheim plot, where the value of ?, the field enhancement factor, was found to be 1517. This value increased to 3357 when nitrogen was doped, but decreased to 974 when boron was doped. The incorporation of nitrogen or boron into the carbon network apparently changes the original nanostructure and the chemical bonding. The structural and compositional modification by the incorporation of nitrogen, boron, or hydrogen into the 1-D carbon-related nanostructured materials were analyzed by FTIR , XPS , Raman spectroscopy , and FE-SEM . Various forms in connection with 1-D nanostructured materials applicable to the NEMS , e.g. , nanowelding of nanotubes[4], tubes on tube , open-end nanotubes and coils of nanofiber and nanotubes have been produced in this research depending on the plasma chemistry, catalytic effect and the design of template. [1]. S. Iijima, Nature 354, 56 (1991). [2]. S. L. Sung, S. H. Tsai, C. H. Tseng, X. W. Liu, and H. C. Shih, Appl. Phys. Lett. 74, 197 (1999). [3]. S. H. Tsai,
Grinberg, L; Cheever, E; Anor, T; Madsen, J R; Karniadakis, G E
2011-01-01
We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models with rigid walls show good agreement in massflow distribution at tens of arterial junctions and also in pressure drop along the arteries. The 3D simulations with the rigid walls predict higher amplitude of the flowrate and pressure temporal oscillations than the 1D simulations with compliant walls at various segments even for small time-variations in the arterial cross-sectional areas. Sensitivity of the flow and pressure with respect to variation in the elasticity parameters is investigated with the 1D model. PMID:20661645
Non-uniform black strings and the critical dimension in the 1/D expansion
Suzuki, Ryotaku; Tanabe, Kentaro
2015-10-01
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 * ? 13 .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.
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.
Derivative expansion and the induced Chern-Simons term in N=1, d=3 superspace
Gama, F S; Petrov, A Yu
2015-01-01
In this paper we apply a supersymmetric generalization of the method of derivative expansion to compute the induced non-Abelian Chern-Simons term in $\\mathcal{N}=1$, $d=3$ superspace, for an arbitrary gauge group.
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 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.)
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.
Mott-insulator phases of non-locally coupled 1D dipolar Bose gases
Arguelles, A.; Santos, L
2006-01-01
We analyze the Mott-insulator phases of dipolar bosonic gases placed in neighboring but unconnected 1D traps. Whereas for short-range interactions the 1D systems are independent, the non-local dipole-dipole interaction induces a direct Mott-insulator to pair-superfluid transition which significantly modifies the boundaries of the lowest Mott-insulator phases. The lowest boundary of the lowest Mott regions becomes progressively constant as a function of the hopping rate, even...
1-D Systolic Arrays Design of LMS Adaptive (FIR) Digital Filtering
Ali H. Mahdi; Bakir A. R. Al-Hashemy; Riyadh A.H. AL-Helali
2010-01-01
This paper extends the 1-D systolic array approach with a method of systematic linear design of systolic algorithms. Past methods for mapping the Least-Mean-Square (LMS) Adaptive Finite-Impulse-Response (FIR) filter onto parallel and pipelined architectures either introduce delays in the coefficients updates or have excessive hardware requirements. In this article, we describe an efficient 1-D systolic array for the LMS adaptive FIR filter that produces the same output and error signals as pr...
Momentum conservation implies anomalous energy transport in 1d classical lattices
Prosen, Tomaz; Campbell, David K.
1999-01-01
Under quite general conditions, we prove that for classical many-body lattice Hamiltonians in one dimension (1D) total momentum conservation implies anomalous conductivity in the sense of the divergence of the Kubo expression for the coefficient of thermal conductivity, $\\kappa$. Our results provide rigorous confirmation and explanation of many of the existing ``surprising'' numerical studies of anomalous conductivity in 1D classical lattices, including the celebrated Fermi-...
Energy Technology Data Exchange (ETDEWEB)
Marinkovic, Bojan A., E-mail: bojan@puc-rio.br [Departamento de Engenharia de Materiais, Pontificia Universidade Catolica de Rio de Janeiro-PUC-Rio, Rua Marques de Sao Vicente 225, Gavea, RJ (Brazil); Fredholm, Yann C. [Nanogavea-Nanotecnologia Sustentavel Ltda, Av. Padre Leonel Franca 150, Gavea, RJ (Brazil); Morgado, Edisson [PETROBRAS S.A./CENPES, Research and Development Centre, Av. Horacio Macedo, 950, Cidade Universitaria, 21941-915, Rio de Janeiro, RJ (Brazil); Jardim, Paula M.; Rizzo, Fernando [Departamento de Engenharia de Materiais, Pontificia Universidade Catolica de Rio de Janeiro-PUC-Rio, Rua Marques de Sao Vicente 225, Gavea, RJ (Brazil)
2010-10-15
Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO{sub 2}-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO{sub 2}-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO{sub 2}-nanoproducts with different morphologies through a simple process and from a low cost precursor.
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...
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...
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.
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)
Vizoso, Miguel; Ferreira, Humberto J; Lopez-Serra, Paula; Carmona, F Javier; Martínez-Cardús, Anna; Girotti, Maria Romina; Villanueva, Alberto; Guil, Sonia; Moutinho, Catia; Liz, Julia; Portela, Anna; Heyn, Holger; Moran, Sebastian; Vidal, August; Martinez-Iniesta, Maria; Manzano, Jose L; Fernandez-Figueras, Maria Teresa; Elez, Elena; Muñoz-Couselo, Eva; Botella-Estrada, Rafael; Berrocal, Alfonso; Pontén, Fredrik; Oord, Joost van den; Gallagher, William M; Frederick, Dennie T; Flaherty, Keith T; McDermott, Ultan; Lorigan, Paul; Marais, Richard; Esteller, Manel
2015-07-01
Metastasis is responsible for most cancer-related deaths, and, among common tumor types, melanoma is one with great potential to metastasize. Here we study the contribution of epigenetic changes to the dissemination process by analyzing the changes that occur at the DNA methylation level between primary cancer cells and metastases. We found a hypomethylation event that reactivates a cryptic transcript of the Rab GTPase activating protein TBC1D16 (TBC1D16-47 kDa; referred to hereafter as TBC1D16-47KD) to be a characteristic feature of the metastatic cascade. This short isoform of TBC1D16 exacerbates melanoma growth and metastasis both in vitro and in vivo. By combining immunoprecipitation and mass spectrometry, we identified RAB5C as a new TBC1D16 target and showed that it regulates EGFR in melanoma cells. We also found that epigenetic reactivation of TBC1D16-47KD is associated with poor clinical outcome in melanoma, while conferring greater sensitivity to BRAF and MEK inhibitors. PMID:26030178
Slade, Angela T; Lensink, Cornelis; Falshaw, Andrew; Clark, George R; Wright, L James
2014-12-01
The monophosphinite ligands, 1D-1,2;5,6-di-O-cyclopentylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P1), 1D-1,2;5,6-di-O-isopropylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P2), 1D-1,2;5,6-di-O-cyclohexylidene-3-O-methyl-4-O-diphenylphosphino-chiro-inositol (D-P3), and 1D-1,2;5,6-di-O-cyclopentylidene-3-O-ethyl-4-O-diphenylphosphino-chiro-inositol (D-P4), can be conveniently prepared from the chiral natural products 1D-pinitol or 1D-chiro-inositol. On treatment of toluene solutions of RuCl2(PPh3)3 with two mole equivalents of the ligands D-PY (Y = 1-4) the complexes RuCl2(D-P1)2 (1), RuCl2(D-P2)2 (4), RuCl2(D-P3)2 (5), or RuCl2(D-P4)2 (6), respectively, are formed. Similarly, treatment of OsCl2(PPh3)3 with D-P1 gives OsCl2(D-P1)2 (7). The single crystal X-ray structure determination of 1 reveals that each D-P1 ligand coordinates to ruthenium through phosphorus and the oxygen atom of the methoxyl group. Treatment of 1 with excess LiBr or LiI results in metathesis of the chloride ligands and RuBr2(D-P1)2 (2) or RuI2(D-P1)2 (3), respectively, are formed. Exposure of a solution of 1 to carbon monoxide results in the very rapid formation of RuCl2(CO)2(D-P1)2 (8), thereby demonstrating the ease with which the oxygen donors are displaced from the metal and hence the hemilabile nature of the two bidentate D-P1 ligands in 1. Preliminary studies indicate that 1-7 act as catalysts for the asymmetric hydrogenation reactions of acetophenone and 3-quinuclidinone to give the corresponding alcohols in generally high conversions but low enantiomeric excesses. PMID:25315464
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
Benchmarks and models for 1-D radiation transport in stochastic participating media
Energy Technology Data Exchange (ETDEWEB)
Miller, D S
2000-08-21
Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material temperature. Benchmark values and variances for time evolution of the ensemble average of material temperature energy density and radiation transmission are computed via a Monte Carlo type method. These benchmarks are used as a basis for comparison with three other approximate methods of solution. One of these approximate methods is simple atomic mix. The second approximate model is an adaptation of what is commonly called the Levermore-Pomraning model and which is referred to here as the standard model. It is shown that recasting the temperature coupling as a type of effective scattering can be useful in formulating the third approximate model, an adaptation of a model due to Su and Pomraning which attempts to account for the effects of scattering in a stochastic context. This last adaptation shows consistent improvement over both the atomic mix and standard models when used in the 1-D slab geometry but shows limited improvement in the 1-D spherical geometry. Benchmark values are also computed for radiation transmission from the 1-D sphere without material heating present. This is to evaluate the performance of the standard model on this geometry--something which has never been done before. All of the various tests demonstrate the importance of stochastic structure on the solution. Also demonstrated are the range of usefulness and limitations of a simple atomic mix formulation.
Directory of Open Access Journals (Sweden)
Lidia B?aszczyk
2013-07-01
Full Text Available Three sets of hexaploid introgressive triticale lines, with Triticum monococcum ssp. monococcum (cultivated einkorn wheat genes and a bread wheat chromosome 1D substituted for chromosome 1A, and one set of secondary triticale lines were evaluated for grain and flour physicochemical and dough rheological characteristics in two generations (F7 and F8. Genomic in situ hybridization (GISH and fluorescence in situ hybridization (FISH confirmed the 1D/1A chromosome substitution. The presence or absence of einkorn high-molecular-weight (HMW glutenin subunits and the wheat Glu-D1d locus encoding the 5 + 10 subunits was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE, capillary zone electrophoresis, and allele-specific molecular markers. Significant differences were found among physicochemical properties (with the exception of the Hagberg falling number of all introgressive Triticale/T. monococcum lines and the secondary triticale lines. The wheat 1D/1A chromosome substitution also affected these properties. The results showed that in all introgressive triticale lines, the protein and gluten content, Zeleny sedimentation value, and water absorption capacity, were increased. The rheological parameters estimated using micro-farinograph, reomixer, and Kieffer dough extensibility systems also showed an appreciable increase in dough-mixing properties, maximum resistance to extension (Rmax, and dough extensibility. Introgressive Triticale/T. monococcum lines with 5 + 10 subunits have particularly favorable rheological parameters. The results obtained in this study suggest that the cultivated einkorn genome Am, in the context of hexaploid secondary triticale lines and with a wheat 1D/1A substitution, has the potential to improve gluten polymer interactions and be a valuable genetic resource for triticale quality improvement.
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.)
An analytical formulation for the 1D energy spectra in equilibrium wall-bounded turbulence
Tang, Yifeng; Akhavan, Rayhaneh
2010-11-01
While a number of analytical formulations exist for the inertial and dissipation range 3D energy spectra in homogeneous, isotropic turbulence, none of these formulations can be directly applied to the near-wall region of equilibrium wall-bounded flows due to the strong anisotropy of the turbulence structure in the near-wall region. In homogeneous, isotropic turbulence, the 1D spectrum is related to the 3D spectrum through E^1D(k/kd)/(?5?)^14 = 2k/kd^?E^3D(k)/(?5?)^14dkk = 2k/kd^?AKk-53F(k)dkk, where AK is the Kolmogorov constant, F(k) is the dissipation range correction to the Kolmogorov spectrum, ? is the volume-averaged rate of dissipation, and kd= (?/3?)^14 is the Kolmogorov wavenumber. It is shown that an analytical formulation for the inertial and dissipation range 1D energy spectra in equilibrium wall-bounded turbulence can be obtained from E^1D(k?/kd,?)/(??5?)^14 = 2k?/kd,?^?AKk-53F(k)dkk, where ??(z) = denotes the contribution of the gradients in the ?-direction to the total dissipation at wall-normal location z, denotes an ensemble average, and kd,?= (??/3?)^14. The validity of the proposed formulation is demonstrated using 1D spectra obtained from DNS databases of turbulent channel flow with 180
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
VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm
Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Santos, Fernando Acácio Monteiro dos; Almeida, Emerson Rodrigo
2015-01-01
Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Paraná sedimentary basin (Bebedouro and Pirassununga cities), both located in São Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies.
Saturn Ring Seismology: Interpreting the Seismogram
Marley, Mark Scott
2013-01-01
Marley (1990) and Marley and Porco (1993) proposed that f-mode oscillations of Saturn could excite resonant density and bending waves in the inner C-ring. They hypothesized that certain wave features discovered by Rosen et al. (1991) that were not associated with known satellite resonances could be the result of such resonant interactions with the planetary oscillation modes. They also predicted that if this was the case the waves would be found to be density (and not bending) waves by Cassini and predicted the azimuthal wave number of the C-ring waves m. Employing Cassini VIMS stellar occultation data Hedman and Nicholson (2013) have now confirmed the predictions and demonstrated that at least some of the C-ring features identified by Rosen et al. are indeed likely caused by resonant oscillation modes of Saturn. Given this context we have taken a fresh look at the Saturn ring seismology. First we propose that an apparent bending wave denoted 'j' by Rosen may be a second order outer vertical resonance with the l=3, m=2 f-mode of Saturn and discuss the locations of other plausible second order resonances in the rings. Since only a handful of ring resonances have been identified, measuring even one or two additional planetary mode frequencies would substantially assist the process of inverting mode frequencies to constrain Saturn interior's structure. Using the available mode frequencies, modern inversion technique employed in stellar seismology, and a recent set of Saturn interior models we provide an initial estimation of what available mode frequencies are telling us about the interior structure of the planet. Since the f-modes are confined relatively closely to the planetary surface, most of the observed modes probe only the outermost layers of the planet that are already comparatively well understood. However the l = 2 mode does probe relatively deeply into the planet and we will discuss the potential the measurement of this mode frequency has for placing new constraints on the interior structure.
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.
[3H]-5-carboxamidotryptamine labels 5-HT1D binding sites in bovine substantia nigra.
Nowak, H. P.; Mahle, C. D.; Yocca, F. D.
1993-01-01
1. [3H]-5-hydroxytryptamine (5-HT) has been shown to radiolabel at least five types of 5-HT binding sites in mammalian brain tissue, 5-HT1A, 5-HT1C, 5-HT1D and 5-HT1D and 5-HT1E (Frazer et al., 1990). Selective masking of 5-HT1A and 5-HT1C receptors, has uncovered binding sites which display both high (5-HT1D) and low (5-HT1E) affinity for 5-carboxamidotryptamine (5-CT). By utilizing [3H]-5-CT we have eliminated a portion of the complex binding (5-HT1E) seen when [3H]-5-HT is used as a radiol...
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.
Targeted disruption of CD1d prevents NKT cell development in pigs.
Yang, Guan; Artiaga, Bianca L; Hackmann, Timothy J; Samuel, Melissa S; Walters, Eric M; Salek-Ardakani, Shahram; Driver, John P
2015-06-01
Studies in mice genetically lacking natural killer T (NKT) cells show that these lymphocytes make important contributions to both innate and adaptive immune responses. However, the usefulness of murine models to study human NKT cells is limited by the many differences between mice and humans, including that their NKT cell frequencies, subsets, and distribution are dissimilar. A more suitable model may be swine that share many metabolic, physiological, and growth characteristics with humans and are also similar for NKT cells. Thus, we analyzed genetically modified pigs made deficient for CD1d that is required for the development of Type I invariant NKT (iNKT) cells that express a semi-invariant T-cell receptor (TCR) and Type II NKT cells that use variable TCRs. Peripheral blood analyzed by flow cytometry and interferon-? enzyme-linked immuno spot assays demonstrated that CD1d-knockout pigs completely lack iNKT cells, while other leukocyte populations remain intact. CD1d and NKT cells have been shown to be involved in shaping the composition of the commensal microbiota in mice. Therefore, we also compared the fecal microbiota profile between pigs expressing and lacking NKT cells. However, no differences were found between pigs lacking or expressing CD1d. Our results are the first to show that knocking-out CD1d prevents the development of NKT cells in a non-rodent species. CD1d-deficient pigs should offer a useful model to more accurately determine the contribution of NKT cells for human immune responses. They also have potential for understanding how NKT cells impact the health of commercial swine. PMID:25930071
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.
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...
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...
1D-FFLO state in the absence of time-reversal symmetry breaking
Datta, Trinanjan
2008-01-01
A novel route to a one-dimensional Fulde-Ferrell-Larkin-Ovchinnikov (1D-FFLO) state in the absence of broken time-reversal symmetry is proposed in this paper. At present such a state may be encouraged in a clean AlAs quantum wire. Using the AlAs quantum wire as an example it is shown using bosonization and the renormalization group approach that the 1D-FFLO state can arise due to a combination of Coulomb interactions and the unique bandstructure arrangement of the AlAs quant...
Single File Diffusion enhancement in a fluctuating modulated 1D channel
Coupier, G; Guthmann, C; Coupier, Gwennou; Jean, Michel Saint; Guthmann, Claudine
2006-01-01
We show that the diffusion of a single file of particles moving in a fluctuating modulated 1D channel is enhanced with respect to the one in a bald pipe. This effect, induced by the fluctuations of the modulation, is favored by the incommensurability between the channel potential modulation and the moving file periodicity. This phenomenon could be of importance in order to optimize the critical current in superconductors, in particular in the case where mobile vortices move in 1D channels designed by adapted patterns of pinning sites.
Strongly inhibited transport of a 1D Bose gas in a lattice
Fertig, C D; Huckans, J H; Rolston, S L; Phillips, W D; Porto, J V
2004-01-01
We report the observation of strongly damped dipole oscillations of a quantum degenerate 1D atomic Bose gas in a combined harmonic and optical lattice potential. Damping is significant for very shallow axial lattices (0.25 photon recoil energies), and increases dramatically with increasing lattice depth, such that the gas becomes nearly immobile for times an order of magnitude longer than the single-particle tunneling time. Surprisingly, we see no broadening of the atomic quasimomentum distribution after damped motion. Recent theoretical work suggests that quantum fluctuations can strongly damp dipole oscillations of 1D atomic Bose gas, providing a possible explanation for our observations.
Guo, Wenjian; Dong, Aishu; Xing, Chao; Lin, Xiaoji; Pan, Xiahui; Lin, Ying; Zhu, Baoling; He, Muqing; Yao, Rong-Xing
2014-08-01
The antitumor effect of natural killer T cells has been reported in several studies analyzing the expression of CD1d on antigen-presenting cells (APCs). Therefore, the present study questioned whether APCs may be abnormal in the peripheral blood (PB) of acute leukemia (AL) patients, particularly the levels of CD1d. To improve the understanding of the role of CD1d on APCs, the levels of CD1d on monocytes were analyzed in healthy controls, AL patients and AL patients with complete remission (CR). In addition, the correlation between the number of CD3(+)CD56(+) T lymphocytes and levels of CD1d on monocytes was analyzed. Flow cytometry was used to determine the levels of CD1d on monocytes and lymphocytes. A significant decrease was observed in the levels of CD1d on monocytes in the PB of acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients compared with the healthy controls. Simultaneously, significantly different levels of CD1d on monocytes were identified between the CR-AML and the CR-ALL patients; the levels of CD1d on monocytes remained low in the CR-AML patients, while the levels of CD1d on monocytes recovered in the CR-ALL patients. A significantly negative correlation was observed between the number of CD3(+)CD56(+) T lymphocytes and the levels of CD1d on monocytes in AL patients. However, a significantly positive correlation was identified between the cytotoxicity of the CD3(+)CD56(+) T lymphocytes and the levels of CD1d on monocytes. These results suggested that the significantly low levels of CD1d on monocytes may contribute to AML and ALL progression. In addition, a significant correlation was observed between the levels of CD1d on monocytes and the number/cytotoxicity of CD3(+)CD56(+) T lymphocytes in AML and ALL patients. PMID:25009659
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
Probing the dispersion properties of 1D nanophotonic waveguides with far-field Fourier optics
DEFF Research Database (Denmark)
Le Thomas, N.; Jágerská, J.; Houdré, R.; Kotlyar, M.V.; O'Faolain, L.; Beggs, D.M.; O'Brien, D.; Krauss, T.F.; Bolten, J.; Moormann, C.; Wahlbrink, T.; Cyroký, J.; Waldow, M.; Först, M.; Frandsen, Lars Hagedorn; Fage-Pedersen, Jacob; Lavrinenko, Andrei; Borel, Peter Ingo
2008-01-01
We present an advanced Fourier space imaging technique to probe guided light in nanophotonic structures with an effective numerical aperture of 2.5. This superresolution technique allows us to successfully investigate the dispersive properties of 1D nanowaveguides such as photonic crystal W1 waveguides, photonic wire, slot waveguides and couplers.
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)
1D Schr\\"odinger operator with periodic plus compactly supported potentials
Korotyaev, Evgeny
2009-01-01
We consider the 1D Schr\\"odinger operator $Hy=-y''+(p+q)y$ with a periodic potential $p$ plus compactly supported potential $q$ on the real line. The spectrum of $H$ consists of an absolutely continuous part plus a finite number of simple eigenvalues in each spectral gap $\\g_n\
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.
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.
Local entanglement and quantum phase transition in 1D transverse field Ising model
Su, Shi-Quan; Song, Jun-Liang; Gu, Shi-Jian
2006-01-01
In this paper, we study the entanglement between two-neighboring sites and the rest of the system in a simple quantum phase transition of 1D transverse field Ising model. We find that the entanglement shows interesting scaling and singular behavior around the critical point, and then can be use as a convenient marker for the transition point.
HYDRUS-1D Modeling of an Irrigated Agricultural Plot with Application to Aquifer Recharge Estimation
A variety of methods are available for estimating aquifer recharge in semi-arid regions, each with advantages and disadvantages. We are investigating a procedure for estimating recharge in an irrigated basin. The method involves computing irrigation return flows based on HYDRUS-1D modeling of root z...
Pharmacological challenge with a serotonin 1D agonist in alcohol dependence
Pienaar Willie; Maritz J Stefan; Hugo Charmaine J; Vythilingum Bavanisha; Stein Dan J
2005-01-01
Abstract Background Both animal and clinical studies have implicated serotonergic dysfunction in the pathogenesis of alcohol abuse and dependence. However the exact mechanisms involved remain unknown. Theoretically, low serotonin promotes alcohol seeking behavior. Sumatriptan is a serotonin1D agonist. It is postulated that sumatriptan's agonism at this terminal autoreceptor increases negative feedback, creating a net effect of decreased serotonergic neurotransmission. Administration of sumatr...
Comparison between 3D and 1D simulations of a regenerative blower for fuel cell applications
International Nuclear Information System (INIS)
Highlights: ? A hydrogen recirculation blower for automotive fuel cells applications is studied. ? A 3D CFD analysis has been carried out to better understand the internal flows of the machine. ? The CFD results are compared to a 1D model set up by the authors in previous works. ? The main hypotheses put forward for the theoretical 1D model are compatible with the 3D analysis. - Abstract: A 3D Computational Fluid Dynamics (CFD) analysis has been carried out to better understand the internal fluid dynamics of a regenerative blower used for hydrogen recirculation in a Proton Exchange Membrane (PEM), Fuel Cell (FC) utilized for automotive applications. The obtained results are used to highlight the motion of the fluid in the vanes and in the side channel of the machine and to verify the main hypotheses put forward concerning the theoretical 1D model set up by the authors in previous works on the basis of the momentum exchange theory. Finally, the CFD analysis has been used to point out the effect of the slope of the vanes on the performance of the regenerative blower, and the results have been compared with those obtained using of the 1D model.
Quantum group random walks in strongly correlated 2+1 D spin systems
International Nuclear Information System (INIS)
We consider the temporal evolution of strong correlated degrees of freedom in 2+1 D spin systems using the Wilson operator eigenvalues as variables. It is shown that the quantum-group diffusion equation at deformation parameter q being the k-th root of unity has the polynomial solution of degree k. (author). 20 refs, 1 tab
On a 1D transport equation with nonlocal velocity and supercritical dissipation
Do, Tam
2013-01-01
We study a 1D transport equation with nonlocal velocity. First, we prove eventual regularization of the viscous regularization when dissipation is in the supercritical range with non-negative initial data. Next, we will prove global regularity for solutions when dissipation is slightly supercritical. Both results utilize a nonlocal maximum principle.
Quantized 1D- and 2D optical molasses: Laser cooling and spectrum of resonance fluorescene
International Nuclear Information System (INIS)
We present results for laser cooling of optical molasses and the spectrum of resonance fluorescene based on a fully quantum mechanical treatment of the atomic center-of-mass motion for 1D and 2D laser configurations. Our calculations based on recently developed wave function simulations of the quantum master equation for laser cooling
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.
Fresnel Lenses fabricated by femtosecond laser micromachining on Polymer 1D Photonic Crystal
Directory of Open Access Journals (Sweden)
Guduru Surya S.K.
2013-11-01
Full Text Available We report the fabrication of micro Fresnel lenses by femtosecond laser surface ablation on polymer 1D photonic crystals. This device is designed to focus the transmitted wavelength of the photonic crystal and filter the wavelengths corresponding to the photonic band gap region. Integration of such devices in a wavelength selective light harvesting and filtering microchip can be achieved.
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.
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.
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.
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.
Mattarollo, Stephen R; Yong, Michelle; Tan, Lieven; Frazer, Ian H.; Leggatt, Graham R
2010-01-01
NKT cells are key regulators of autoimmunity, tumor immune surveillance, and the immune response to pathogens. The role of NKT cells in regulating adaptive immunity to cutaneous Ags is largely unknown. This study explores the role of CD1d-restricted NKT cells in cross-priming of CD8 effector T cells to OVA expressed in epithelial keratinocytes (K5mOVA transgenic mouse). In a skin grafting model, we show that NKT cells enhance the rejection of K5mOVA skin grafts by promoting generation of OVA-...
Wen, Kechun; He, Weidong
2015-09-01
One-dimensional (1D) nanocrystals, such as nanorods and nanowires, have received extensive attention in the nanomaterials field due to their large surface areas and 1D confined transport properties. Oriented attachment (OA) is now recognized as a major growth mechanism for efficiently synthesizing 1D nanocrystals. Recently, atomic layer deposition (ALD) has been modified to be a powerful vapor-phase technique with which to synthesize 1D OA nanorods/nanowires with high efficiency and quality by increasing the temperature and purging time. In this invited mini-review, we look into the advantages of OA and high-temperature ALD, and investigate the potential of employing the OA growth mechanism for the synthesis of 1D nanocrystals via modified ALD, aiming to provide guidance to researchers in the fields of both OA and ALD for efficient synthesis of 1D nanocrystals.
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
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.
International Nuclear Information System (INIS)
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
Minimum 1D P- and S- Velocity Models for Montenegro and Vicinity
Vucic, Ljiljana; Kissling, Edi; Spakman, Wim; Glavatovic, Branislav
2015-04-01
The territory of Montenegro and its vicinity are characterized by high-seismicity rate and very complex tectonics. Namely, southern Adria microplate subducts beneath Eurasia, forming the Dinarides fold-and-thrust belt which spreads through whole Montenegro and the western Balkans. Present-day lithosphere structure of the Adria-Dinarides collision zone in general is not constrained very well and, consequently, there is a lack of three-dimensional (3D) velocity models in this region. For these reasons, high resolution 3D tomography modeling of this area is considered to be of great importance. As part of preparatory phase for conducting a 3D local earthquake tomography study, a substantial amount of waveform data was collected, from all surroundings national seismic networks including 130 seismic stations from 11 countries. The data set comprises waveforms from 1452 earthquakes in the region recorded during time period 1990 - 2014. The collected data were obtained in different formats and the data base was harmonized by converting and integrating all data to miniseed format. The potential resolution of collected data for seismic tomography purpose was analyzed by ray density testing, using specially developed software for this specific purpose. The result is expressed as the number of rays between selected group of earthquake hypocenters and seismic stations, penetrating through the 3D model of the Earth crust and it documents the great potential of the data set for 3D seismic tomography. As a prerequisite to 3D tomography and for consistent high-precision earthquake locations, a minimum 1D velocity model has been calculated. The data set of around 400 earthquakes was selected from the main database and consistent wave onsets picking was performed, including seismic phase interpretation and its quality assessment. This highly consistent travel time data set is used for calculation of 1D velocity models for the region under study. The minimum 1D models were derived through the iterative inversion procedure using VELEST software. Comparison of the results between previous routinely processed seismic data at the studied area and the earthquake relocation results by applying the new 1D models, shows a significant improvement in quality of hypocenter parameters of all earthquakes used in the experiment. Since a minimum 1D model represents a solution to the coupled hypocenter-velocity problem, the resulting velocity information will be used as a suitable velocity model for further routine earthquake location in the region, and also as the appropriate initial reference model for 3D tomography modeling, applying the full seismic database. Keywords: minimum 1D model, seismic tomography, Velest, Montenegro
GUO, WENJIAN; DONG, AISHU; Xing, Chao; Lin, Xiaoji; PAN, XIAHUI; Lin, Ying; ZHU, BAOLING; HE, MUQING; YAO, RONG-XING
2014-01-01
The antitumor effect of natural killer T cells has been reported in several studies analyzing the expression of CD1d on antigen-presenting cells (APCs). Therefore, the present study questioned whether APCs may be abnormal in the peripheral blood (PB) of acute leukemia (AL) patients, particularly the levels of CD1d. To improve the understanding of the role of CD1d on APCs, the levels of CD1d on monocytes were analyzed in healthy controls, AL patients and AL patients with complete remission (CR...
Energy Technology Data Exchange (ETDEWEB)
West, W.P.; Evans, T.E.; Brooks, N.H. [General Atomics, San Diego, CA (United States)] [and others
1996-10-01
NEWT1D, a one dimensional multifluid model of the scrape-off layer and divertor plasma, has been used to model the plasma including the distribution of carbon ionization states in the SOL and divertor of ELMing H-mode at two injected power levels in DIII-D. Comparison of the code predictions to the measured divertor and scrape-off layer (SOL) plasma density and temperature shows good agreement. Comparison of the predicted line emissions to the spectroscopic data suggests that physically sputtered carbon from the strike point is not transported up the flux tube; a distributed source of carbon a few centimeters up the flux tube is required to achieve reasonable agreement.
Energy Technology Data Exchange (ETDEWEB)
Pino, N.A. [Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Via Diocleziano 328, 80124 Napoli (Italy)
2011-06-15
Seismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100-120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques. In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the 20. century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) - both of which are the strongest ever recorded instrumentally in their respective countries - and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismo-genic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Appennines. (author)
ZnO 1-D nanostructures: Low temperature synthesis and characterizations
Indian Academy of Sciences (India)
Apurba Dev; S Chaudhuri; B N Dev
2008-06-01
ZnO is one of the most important semiconductors having a wide variety of applications in photonic, field emission and sensing devices. In addition, it exhibits a wide variety of morphologies in the nano regime that can be grown by tuning the growth habit of the ZnO crystal. Among various nanostructures, oriented 1-D nanoforms are particularly important for applications such as UV laser, sensors, UV LED, field emission displays, piezoelectric nanogenerator etc. We have developed a soft chemical approach to fabricate well-aligned arrays of various 1-D nanoforms like nanonails, nanowires and nanorods. The microstructural and photoluminescence properties of all the structures were investigated and tuned by varying the synthesis parameters. Field emission study from the aligned nanorod arrays exhibited high current density and a low turn-on field. These arrays also exhibited very strong UV emission and week defect emission. These structures can be utilized to fabricate efficient UV LEDs.
Quantitative Multiscale Analysis using Different Wavelets in 1D Voice Signal and 2D Image
Shakhakarmi, Niraj
2012-01-01
Mutiscale analysis represents multiresolution scrutiny of a signal to improve its signal quality. Multiresolution analysis of 1D voice signal and 2D image is conducted using DCT, FFT and different wavelets such as Haar, Deubachies, Morlet, Cauchy, Shannon, Biorthogonal, Symmlet and Coiflet deploying the cascaded filter banks based decomposition and reconstruction. The outstanding quantitative analysis of the specified wavelets is done to investigate the signal quality, mean square error, entropy and peak-to-peak SNR at multiscale stage-4 for both 1D voice signal and 2D image. In addition, the 2D image compression performance is significantly found 93.00% in DB-4, 93.68% in bior-4.4, 93.18% in Sym-4 and 92.20% in Coif-2 during the multiscale analysis.
Energy Technology Data Exchange (ETDEWEB)
Sabtaji, Agung, E-mail: sabtaji.agung@gmail.com, E-mail: agung.sabtaji@bmkg.go.id [Study Program of Earth Sciences, Faculty of Earth Sciencies and Technology, Institute of Technology Bandung, Bandung 40132 (Indonesia); Indonesia’s Agency for Meteorological, Climatological and Geophysics Region V, Jayapura 1572 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Bandung 40132 (Indonesia)
2015-04-24
West Papua region has fairly high of seismicity activities due to tectonic setting and many inland faults. In addition, the region has a unique and complex tectonic conditions and this situation lead to high potency of seismic hazard in the region. The precise earthquake hypocenter location is very important, which could provide high quality of earthquake parameter information and the subsurface structure in this region to the society. We conducted 1-D P-wave velocity using earthquake data catalog from BMKG for April, 2009 up to March, 2014 around West Papua region. The obtained 1-D seismic velocity then was used as input for improving hypocenter location using double-difference method. The relocated hypocenter location shows fairly clearly the pattern of intraslab earthquake beneath New Guinea Trench (NGT). The relocated hypocenters related to the inland fault are also observed more focus in location around the fault.
International Nuclear Information System (INIS)
During first rise to power in Power Water Reactor, fuel pellets crack because of thermal expansion. The phenomena of pellet cracking and fragments relocation have a major influence on rod behaviour and especially on the cladding behaviour in the case of pellet-cladding interaction. This article presents the modeling used to take into account the fragmented state of the pellet in the EDF fuel rod thermo-mechanical code, CYRANO3reg. The aim is to simulate more realistic stress and strain fields in the pellet. The investigated method consists in adding parameters in the 1D finite elements calculations in order to integrate the multi-dimensional fragmentation effects in the axisymmetrical 1D code CYRANO3reg. These parameters modify the material behaviour by describing the fuel as an anisotropic damaged material. The modeling accounts for the opening and closing of radial pellet cracks. It has been implemented in the code for elastic and viscoplastic fuel behaviours
The two canonical conjugate pairs at the horizon of a D1D5 black hole
Hadad, Merav
2015-01-01
The Euclidian opening angle at the $r-t_E$ surface, $\\Theta_{r-t_E}$ at the horizon of a black hole is canonically conjugate to the black hole entropy. We prove that for a $D1D5$ black hole there exists in addition to this pair, another canonical pair: the opening angle at the $r-y$ surface, $\\Theta_{r-y}$ and a Wald like term $S_{Wr-y}$. This leads to an uncertainty at $\\Theta_{r-y}$ which suggests that the surface $r-y$ is actually a superposition of surfaces with different conical singularities. This corresponds to the same type of singularities obtained by string theory excitations of a $D1D5$ black hole.
A method to simulate inhomogeneously irradiated objects with a superposition of 1D models
Guenther, H M; 10.1051/0004-6361/201014824
2011-01-01
In close binary systems the atmosphere of one or both components can be significantly influenced by irradiation from the companion. Often the irradiated atmosphere is simulated with a single-temperature approximation for the entire half-sphere. We present a scheme to take the varying irradiation angle into account by combining several separate 1D models. This is independent of the actual code which provides the separate stellar spectra. We calculate the projected area of zones with given irradiation angle and use this geometrical factor to scale separate 1D models. As an example we calculate two different irradiation scenarios with the PHOENIX code. The scheme to calculate the projected area is applicable independent of the physical mechanism that forms these zones. In the case of irradiation by a primary with T=125000 K, the secondary forms ions at different ionisation states for different irradiation angles. No single irradiation angle exists which provides an accurate description of the spectrum. We show a...
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.
Static sign language recognition using 1D descriptors and neural networks
Solís, José F.; Toxqui, Carina; Padilla, Alfonso; Santiago, César
2012-10-01
A frame work for static sign language recognition using descriptors which represents 2D images in 1D data and artificial neural networks is presented in this work. The 1D descriptors were computed by two methods, first one consists in a correlation rotational operator.1 and second is based on contour analysis of hand shape. One of the main problems in sign language recognition is segmentation; most of papers report a special color in gloves or background for hand shape analysis. In order to avoid the use of gloves or special clothing, a thermal imaging camera was used to capture images. Static signs were picked up from 1 to 9 digits of American Sign Language, a multilayer perceptron reached 100% recognition with cross-validation.
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
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)
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.
Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation
Energy Technology Data Exchange (ETDEWEB)
Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica
2015-12-22
Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.
Rotating condensed-boson gases in a 1D lattice at finite temperature
International Nuclear Information System (INIS)
In this paper, we study the thermodynamic properties of a rotating boson gases in a one-dimensional (1D) optical lattice at finite temperature. Our system is formed by loading three-dimensional boson-clouds into 1D optical lattice and subjected to rotate with angular velocity ? about the z-axis (rotating condensate in a quasi-two-dimensional trap). We employ the semiclassical approximation to calculate the condensate fraction, critical temperature and the heat capacity of the system. The calculated results show that the rotating condensates in a quasi-two-dimensional have interesting properties which are absent in both three or pure two-dimensional systems. Our results can be extended to investigate the current experiments of rotating Bose–Einstein condensation produced or transferred in one-dimensional optical lattices
Observation of Reduced Three-Body Recombination in a Fermionized 1D Bose Gas
Tolra, B L; Huckans, J H; Phillips, W D; Rolston, S L; Porto, J V
2003-01-01
We investigate correlation properties of a one-dimensional interacting Bose gas by loading a magnetically trapped 87-Rb Bose-Einstein condensate into a deep two-dimensional optical lattice. We measure the three-body recombination rate for both the BEC in the magnetic trap and the BEC loaded into the optical lattice. The recombination rate coefficient is a factor of seven smaller in the lattice, which we interpret as a reduction in the local three-body correlation function in the 1D case. This is a signature of correlation intermediate between that of the uncorrelated phase coherent 1D mean-field regime and the strongly correlated Tonks-Girardeau regime.
Formulações semi-discretas para a equação 1D de Burgers
Scientific Electronic Library Online (English)
C.A., Ladeia; N.M.L., Romeiro; P.L., Natti; E.R., Cirilo.
2013-12-01
Full Text Available Neste trabalho fizemos comparações entre formulações semi-discretas para a obtenção de soluções numéricas para a equação 1D de Burgers. As formulações consistem em discretizar o domínio temporal via métodos implícitos multi-estágios de segunda e quarta ordem: aproximantes de Padé R11 e R22; e o domí [...] nio espacial via métodos de elementos finitos: mínimos quadrados (MEFMQ), Galerkin (MEFG) e Streamline-Upwind Petrov-Galerkin (SUPG). Conhecendo as soluções analíticas da equação 1D de Burgues, para diferentes condições iniciais e de fronteira, foram realizadas análises dos erros numéricos a partir das normas L2 e L?. Verificamos que o método com o aproximante de Padé R22 adicionado as formulações MEFMQ, MEFG e SUPG, aumentou a região de convergência das soluções numéricas e apresentou maior precisão quando comparado as soluções obtidas por meio do aproximante de Padé R11. Constatamos que o método R22 amenizou as oscilações das soluções numéricas associadas as formulações MEFG e SUPG. Abstract in english In this work we compare semi-discrete formulations to obtain numericalsolutions for the 1D Burgers equation. The formulations consist in the discretization ofthe time-domain via multi-stage methods of second and fourth order: R11 and R22 Padé approximants, and of the spatial-domain via finite elemen [...] t methods: least-squares (MEFMQ), Galerkin (MEFG) and Streamline-Upwind Petrov-Galerkin (SUPG). Knowing the analytical solutions of the 1D Burgues equation, for different initial and boundary conditions, analyzes were performed for numerical errors from L2 and L? norm. We found that the R22 Padé approximants, added to the MEFMQ, MEFG, and SUPG formulations, increased the region of convergence of the numerical solutions, and showed greater accuracy when compared to the solutions obtained by the R11 Padé approximants. We note that the R22 Padé approximants softened the oscillations of the numerical solutions associated to the MEFG and SUPG formulations.
Modeling Soil Salt and Nitrogen Transport under Different Fertigation Practices with Hydrus-1D
Zeng Wen-zhi; Huang Jie-sheng; Wu Jing-wei; Xu Chi
2013-01-01
In this study the effects of different fertigation practices on salt and nitrogen dynamics were analyzed in the Hetao District, China by using the Hydrus-1D model. The results indicated that the soil electrical conductivity increased gradually with depth after irrigation and the electrical conductivity of 0~60 cm depth changed faster than that of 60~100 cm depth. However, the soil ammonium nitrogen concentration decreased with depth and high irrigation intensity could promote the increase of ...
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.
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.
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
Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry.
Araneo, Rodolfo; Lovat, Giampiero; Burghignoli, Paolo; Falconi, Christian
2012-09-01
The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices. PMID:22544730
Prediction of car cabin environment by means of 1D and 3D cabin model
Jícha M.; Pokorný J.; Fišer J.
2012-01-01
Thermal comfort and also reduction of energy requirements of air-conditioning system in vehicle cabins are currently very intensively investigated and up-to-date issues. The article deals with two approaches of modelling of car cabin environment; the first model was created in simulation language Modelica (typical 1D approach without cabin geometry) and the second one was created in specialized software Theseus-FE (3D approach with cabin geometry). Performance and capabilities of this t...
A facile route for 3D aerogels from nanostructured 1D and 2D materials
Sung Mi Jung; Hyun Young Jung; Mildred S. Dresselhaus; Yung Joon Jung; Jing Kong
2012-01-01
Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the tra...
Diffusive Public Goods and Coexistence of Cooperators and Cheaters on a 1D Lattice
Scheuring, István
2014-01-01
Many populations of cells cooperate through the production of extracellular materials. These materials (enzymes, siderophores) spread by diffusion and can be applied by both the cooperator and cheater (non-producer) cells. In this paper the problem of coexistence of cooperator and cheater cells is studied on a 1D lattice where cooperator cells produce a diffusive material which is beneficial to the individuals according to the local concentration of this public good. The reproduction success ...
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.
Finite difference approximation of control via the potential in a 1-D Schrodinger equation
Directory of Open Access Journals (Sweden)
K. Kime
2000-04-01
Full Text Available We consider the problem of steering given initial data to given terminal data via a time-dependent potential, the control, in a 1-D Schrodinger equation. We determine a condition for existence of a transferring potential within our approximation. Using Maple, we give equations for the control and also examples in which the potential is restricted to be centralized and to be a step potential.
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...
Monte Carlo simulation for radiation transport: collision density in a 1-D slab
Z. U. Koreshi; S. Siddiq
2010-01-01
Monte Carlo (MC) simulation has been abundantly used for simulation of radiation transport (thermal, neutron, charged-particle etc) in matter. In thermal radiation, for example, surface radiosities and subsequent heat fluxes have been accurately determined in configurations which are difficult for deterministic formulations. In this paper, we consider estimation of the collision density in a 1-D slab and compare with the exact solution. The accuracy of the simulation results is discussed and ...
Equilibrium and off-equilibrium trap-size scaling in 1D ultracold bosonic gases
Campostrini, Massimo; Vicari, Ettore
2010-01-01
We study some aspects of equilibrium and off equilibrium quantum dynamics of dilute bosonic gases in the presence of a trapping potential. We consider systems with a fixed number of particles N and study their scaling behavior with increasing the trap size. We focus on one-dimensional (1D) bosonic systems, such as gases described by the Lieb-Liniger model and its Tonks-Girardeau limit of impenetrable bosons, and gases constrained in optical lattices as described by the Bose-...
Modeling and simulation of concrete carbonation in 1-d using two-point flux approximation
Røe, Tineke
2013-01-01
In this master's thesis we will model concrete carbonation using mass conservation equations and Darcy's law. We then get a set of coupled partial differential equations. We also have a ordinary differential equation modeling porosity change. These equations are discretized using two-point flux approximation for 1-d in space, and Euler implicit in time. We have a nonlinear pressure equation which is linearized using Newton method. We run simulations, and the results are compared to a const...
Yao, Ruiwen; Xiang, Zhihai
2014-01-01
In contrast to traditional Navier equations, a more comprehensive formulation of one dimensional (1D) elastic wave equations is proposed for inhomogeneous media by using the coordinate transformation method. These modified equations are form-invariant and can retain time synchronization under spatial coordinate transformation, which are equivalent requirements from the principle of relativity. A numerical example is conducted to compare the distributions of wave speed calcul...
Probing the quantum state of a 1D Bose gas using off-resonant light scattering
Sykes, A. G.; Ballagh, R J
2011-01-01
We present a theoretical treatment of coherent light scattering from an interacting 1D Bose gas at finite temperatures. We show how this can provide a nondestructive measurement of the atomic system states. The equilibrium states are determined by the temperature and interaction strength, and are characterized by the spatial density-density correlation function. We show how this correlation function is encoded in the angular distribution of the fluctuations of the scattered ...
Scattering coefficients and gray-body factor for 1D BEC acoustic black holes: exact results
Fabbri, Alessandro; Anderson, Paul R
2015-01-01
A complete set of exact analytic solutions to the mode equation are found in the region exterior to the acoustic horizon for a class of 1D Bose-Einstein condensate (BEC) acoustic black holes. From these, analytic expressions for the scattering coefficients and gray-body factor are obtained. The results are used to verify previous predictions regarding the behaviors of the scattering coefficients and gray-body factor in the low frequency limit.
TBC1D14 regulates autophagosome formation via Rab11- and ULK1-positive recycling endosomes
Longatti, A; Lamb, CA; M Razi; Yoshimura, S.; Barr, FA; Tooze, SA
2012-01-01
Autophagy is a bulk degradation process characterized by the formation of double membrane vesicles called autophagosomes. The exact molecular mechanism of autophagosome formation and the origin of the autophagosomal membrane remain unclear. We screened 38 human Tre-2/Bub2/Cdc16 domain-containing Rab guanosine triphosphatase-activating proteins (GAPs) and identified 11 negative regulators of starvation-induced autophagy. One of these putative RabGAPs, TBC1D14, colocalizes and interacts with th...
From GPE to KPZ: finite temperature dynamical structure factor of the 1D Bose gas
Kulkarni, Manas; Lamacraft, Austen
2012-01-01
We study the finite temperature dynamical structure factor $S(k,\\omega)$ of a 1D Bose gas using numerical simulations of the Gross--Pitaevskii equation appropriate to a weakly interacting system. The lineshape of the phonon peaks in $S(k,\\omega)$ has a width $\\propto |k|^{3/2}$ at low wavevectors. This anomalous width arises from resonant three-phonon interactions, and reveals a remarkable connection to the Kardar--Parisi--Zhang universality class of dynamical critical pheno...
Partial Internal Control Recovery on 1-D Klein-Gordon Systems
Iwan Pranoto
2010-01-01
In this exposition, a technique to recover internal control on a distributed parameter system is reported. The system is described by 1-D Klein-Gordon partial differential equation with a time-varying parameter. We would like to recover the internal control applied to the system if we know some limited information about the output. We use a method called sentinel method to recover the internal control. It involves some construction of a linear functional, and we show that this construction re...
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.
Recessive TBC1D24 Mutations Are Frequent in Moroccan Non-Syndromic Hearing Loss Pedigrees
Bakhchane, Amina; Charif, Majida; Salime, Sara; Boulouiz, Redouane; Nahili, Halima; Roky, Rachida
2015-01-01
Mutations in the TBC1D24 gene are responsible for four neurological presentations: infantile epileptic encephalopathy, infantile myoclonic epilepsy, DOORS (deafness, onychodystrophy, osteodystrophy, mental retardation and seizures) and NSHL (non-syndromic hearing loss). For the latter, two recessive (DFNB86) and one dominant (DFNA65) mutations have so far been identified in consanguineous Pakistani and European/Chinese families, respectively. Here we report the results of a genetic study performed on a large Moroccan cohort of deaf patients that identified three families with compound heterozygote mutations in TBC1D24. Four novel mutations were identified, among which, one c.641G>A (p.Arg214His) was present in the three families, and has a frequency of 2% in control Moroccan population with normal hearing, suggesting that it acts as an hypomorphic variant leading to restricted deafness when combined with another recessive severe mutation. Altogether, our results show that mutations in TBC1D24 gene are a frequent cause (>2%) of NSHL in Morocco, and that due to its possible compound heterozygote recessive transmission, this gene should be further considered and screened in other deaf cohorts. PMID:26371875
Study of 1D stranged-charm meson family using HQET
Gupta, Pallavi
2015-01-01
Recently LHCb predicted spin 1 and spin 3 states D* s1(2860) and D* s3(2860) which are studied through their strong decays, and are assigned to fit the 13D1and 13D3 states in the charm spectroscopy. In this paper,using the heavy quark effective theory, we state that assigning D*s1(2860) as the mixing of 13D1 - 23S1 states, is rather a better justification to its observed experimental values than a pure state. We study its decay modes variation with hadronic coupling constant gxh and the mixing angle . We appoint spin 3 state D* s3(2860) as the missing 1D 3- JP state, and also study its decay channel behavior with coupling constant gyh. To appreciate the above results, we check the variation of decay modes for their spin partners states i.e. 1D2 and 1D'2 with their masses and strong coupling constant i.e. gxh and gyh. Our calculation using HQET approach give mixing angle between the 13D1 - 23S1 state for D* s1(2860) to lie in the range (-1.6 radians < theta < -1.2 radians). Our calculation for coupling c...
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.
A two-layer $\\alpha\\omega$ dynamo model, and its implications for 1-D dynamos
Roald, C B
1999-01-01
I will discuss an attempt at representing an interface dynamo in a simplified, essentially 1D framework. The operation of the dynamo is broken up into two 1D layers, one containing the $\\alpha$ effect and the other containing the $\\omega$ effect, and these two layers are allowed to communicate with each other by the simplest possible representation of diffusion, an analogue of Newton's law of cooling. Dynamical back-reaction of the magnetic field on them with diagrams I computed for a comparable purely 1D model. The bifurcation structure shows remarkable similarity, but a couple of subtle changes imply dramatically different physical behaviour for the model. In particular, the solar-like dynamo mode found in the 1-layer model is not stable in the 2-layer version; instead there is an (apparent) homoclinic bifurcation and a sequence of periodic, quasiperiodic, and chaotic modes. I argue that the fragility of these models makes them effectively useless as predictors or interpreters of more complex dynamos.
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
International Nuclear Information System (INIS)
Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely, the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal 235U concentration levels to reflux levels remain satisfactory detectable
Transient dynamic and modeling parameter sensitivity analysis of 1D solid oxide fuel cell model
International Nuclear Information System (INIS)
Highlights: • A multiphysics, 1D, dynamic SOFC model is developed. • The presented model is validated experimentally in eight different operating conditions. • Electrochemical and thermal dynamic transient time expressions are given in explicit forms. • Parameter sensitivity is discussed for different semi-empirical parameters in the model. - Abstract: In this paper, a multiphysics solid oxide fuel cell (SOFC) dynamic model is developed by using a one dimensional (1D) modeling approach. The dynamic effects of double layer capacitance on the electrochemical domain and the dynamic effect of thermal capacity on thermal domain are thoroughly considered. The 1D approach allows the model to predict the non-uniform distributions of current density, gas pressure and temperature in SOFC during its operation. The developed model has been experimentally validated, under different conditions of temperature and gas pressure. Based on the proposed model, the explicit time constant expressions for different dynamic phenomena in SOFC have been given and discussed in detail. A parameters sensitivity study has also been performed and discussed by using statistical Multi Parameter Sensitivity Analysis (MPSA) method, in order to investigate the impact of parameters on the modeling accuracy
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.
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...
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)
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)
International Nuclear Information System (INIS)
We present results from an experimental characterization of fast electron transport in high density plasmas created by 1D shock wave compression. The K? fluorescence from a Cu layer embedded in Al or CH foil targets is measured. We use long laser pulses (LP) with 180 J, 1.5 ns, 0.53?m to compress the foils by shock wave propagation to 2-3 times their solid density and heat them to ? 4eV (close to the Fermi temperature). A counter-propagating high-intensity short laser pulse (SP), with 40 J, 1 ps, 57x1019 Wcm-2, generates intense currents of fast electrons which propagate through the deep regions of the target just before shock breakthrough. The results are compared to the uncompressed, solid density case (without the LP beam). The complete set of measurements is compared to numerical results, including a 2D hydrodynamic description of the compression and pre-pulse effects, 2D PIC simulations of the SP beam interaction and both hybrid and PIC simulations of the electron transport in the target depth and sheaths. In the case of the non-compressed targets we need to take fast electron refluxing into account to reproduce the experimental results. By exploring the domain of warm temperatures, we identify a regime for the incident fast electron current density, 1010 12 Acm-2, for which the collective mechanisms of electron transport differs appreciably between solid density and compressed matter.
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.
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.
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.
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 ...
Lee, Kyungyong
2009-01-01
Let $I$ be the ideal generated by alternating polynomials in two sets of $n$ variables. Haiman proved that the $q,t$-Catalan number is the Hilbert series of the graded vector space $M(=\\bigoplus_{d_1,d_2}M_{d_1,d_2})$ spanned by a minimal set of generators for $I$. In this paper we give simple upper bounds on $\\text{dim}M_{d_1, d_2}$ in terms of partition numbers, and find all bi-degrees $(d_1,d_2)$ such that $\\dim M_{d_1, d_2}$ achieve the upper bounds. For such bi-degrees, we also find explicit bases for $M_{d_1, d_2}$. The main idea is to define and study a nontrivial linear map from $M$ to a polynomial ring $\\C[\\rho_1, \\rho_2,...]$.
Uno, Yasuhiro; Uehara, Shotaro; Murayama, Norie; Yamazaki, Hiroshi
2011-02-01
Cytochrome P450 (P450 or CYP) 1 family consists of the CYP1A, CYP1B, CYP1C, and CYP1D subfamilies. In the human genome, CYP1A1, CYP1A2, and CYP1B1 are expressed and encode functional enzymes, whereas CYP1D1P (formerly known as CYP1A8P) is present as a pseudogene due to five nonsense mutations in the putative coding region. In this study, we identified CYP1D1 cDNA, highly identical (nearly 95%) to human CYP1D1P sequence, in cynomolgus monkey, a species frequently used in drug metabolism studies due to its evolutionary closeness to human. The amino acid sequence deduced from cynomolgus monkey CYP1D1 cDNA shared the high sequence identity (91%) with human CYP1D1P (postulated from the gene sequence), and the highest sequence identity (44-45%) with CYP1A1 and CYP1A2 among cynomolgus monkey P450s. CYP1D1 mRNA was most abundantly expressed in liver, followed by kidney, and jejunum. The hepatic expression level of CYP1D1 mRNA was comparable to that of CYP1A1 mRNA and much higher than that of CYP1A2 mRNA. CYP1D1 was barely detectable in immunoblots of cynomolgus monkey liver. Cynomolgus monkey CYP1D1 mRNA was induced in primary hepatocytes with omeprazole. Cynomolgus monkey CYP1D1 protein heterologously expressed in Escherichia coli catalyzed ethoxyresorufin O-deethylation and caffeine 8-hydroxylation, which CYP1As also catalyze. Finally, no nonsense mutations, corresponding to those found in human CYP1D1P, were found in the 20 cynomolgus monkeys and 10 rhesus monkeys used in this study. These results suggest that CYP1D1 plays a role as a functional, drug-metabolizing enzyme in cynomolgus monkey liver. PMID:21070747
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.
Group-decoupled multi-group pin power reconstruction utilizing nodal solution 1D flux profiles
International Nuclear Information System (INIS)
Highlights: • A direct fitting multi-group pin power reconstruction method is developed. • The 1D nodal solution flux profiles are used as the condition. • The least square fit problem is analytically solved. • A slowing down source improvement method is applied. • The method shows good accuracy for even challenging problems. - Abstract: A group-decoupled direct fitting method is developed for multi-group pin power reconstruction, which avoids both the complication of obtaining 2D analytic multi-group flux solution and any group-coupled iteration. A unique feature of the method is that in addition to nodal volume and surface average fluxes and corner fluxes, transversely-integrated 1D nodal solution flux profiles are also used as the condition to determine the 2D intra-nodal flux distribution. For each energy group, a two-dimensional expansion with a nine-term polynomial and eight hyperbolic functions is used to perform a constrained least square fit to the 1D intra-nodal flux solution profiles. The constraints are on the conservation of nodal volume and surface average fluxes and corner fluxes. Instead of solving the constrained least square fit problem numerically, we solve it analytically by fully utilizing the symmetry property of the expansion functions. Each of the 17 unknown expansion coefficients is expressed in terms of nodal volume and surface average fluxes, corner fluxes and transversely-integrated flux values. To determine the unknown corner fluxes, a set of linear algebraic equations involving corner fluxes is established via using the current conservation condition on all corners. Moreover, an optional slowing down source improvement method is also developed to further enhance the accuracy of the reconstructed flux distribution if needed. Two test examples are shown with very good results. One is a four-group BWR mini-core problem with all control blades inserted and the other is the seven-group OECD NEA MOX benchmark, C5G7
1D-3D registration for intra-operative nuclear imaging in radio-guided surgery.
Vetter, Christoph; Lasser, Tobias; Okur, Asli; Navab, Nassir
2015-02-01
3D functional nuclear imaging modalities like SPECT or PET provide valuable information, as small structures can be marked with radioactive tracers to be localized before surgery. This positional information is valuable during surgery as well, for example when locating potentially cancerous lymph nodes in the case of breast cancer. However, the volumetric information provided by pre-operative SPECT scans loses validity quickly due to posture changes and manipulation of the soft tissue during surgery. During the intervention, the surgeon has to rely on the acoustic feedback provided by handheld gamma-detectors in order to localize the marked structures. In this paper, we present a method that allows updating the pre-operative image with a very limited number of tracked readings. A previously acquired 3D functional volume serves as prior knowledge and a limited number of new 1D detector readings is used in order to update the prior knowledge. This update is performed by a 1D-3D registration algorithm that registers the volume to the detector readings. This enables the rapid update of the visual guidance provided to the surgeon during a radio-guided surgery without slowing down the surgical workflow. We evaluate the performance of this approach using Monte-Carlo simulations, phantom experiments and patient data, resulting in a positional error of less than 8 mm which is acceptable for surgery. The 1D-3D registration is also compared to a volumetric reconstruction using the tracked detector measurements without taking prior information into account, and achieves a comparable accuracy with significantly less measurements. PMID:25343756
1-D and 2-D electrophoresis protein profiles of the scorpion venom from Brotheas amazonicus
Energy Technology Data Exchange (ETDEWEB)
Higa, A.M.; Noronha, M.D.N. [Universidade do Estado do Amazonas (UEA), Manaus, AM (Brazil). Rede Proteomica do Amazonas (Proteam). Lab. de Genomica e Proteomica; Rocha-Oliveira, F.; Lopez-Lozano, J.L.L. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Pos-Graduacao em Biotecnologia
2008-07-01
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 {approx} 60, 70 and 80 kDa were detected in gel acidic region with pI {approx} 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 {approx} 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 {approx} 7 kDa, suggesting scorpion neurotoxins. In gel basic region only 14 kDa proteins were observed with pI {approx} 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. amazonicus venom suggest scorpion neurotoxins. Purification and molecular characterization of these toxins are in course.
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. amazonicus venom suggest scorpion neurotoxins. Purification and molecular characterization of these toxins are in course
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.
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. ...
Exponentially long Equilibration times in a 1-D Collisional Model of a classical gas
DEFF Research Database (Denmark)
Hjorth, Poul; Benettin, G.
1999-01-01
Around the year 1900, J.H. Jeans suggested that the `abnormal' specific heats observed in diatomic gases, specifically the lack of contribution to the heat capacity from the internal vibrational degrees of freedom, in apparent violation of the equipartition theorem, might be caused by the large separation between the time scale for the vibration and the time scale associated with a typical binary collision in the gas. We consider here a simple 1-D model, and show how, when these time scales are ...
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.
1D burnup calculation of fusion-fission hybrid energy reactor
International Nuclear Information System (INIS)
Fusion-fission hybrid energy reactor is driven by Tokamak fusion source for energy production. Its subcritical zone uses the natural uranium as fuel and water as coolant. The neutron multiplication constant keff, energy multiplication factor M and tritium breeding ratio TBR of the 1D hybrid energy reactor model were calculated by transport burnup code MCORGS. The neutron spectrum and nuclear density changing as a function of time show the characteristics of the hybrid energy reactors, which differs from the hybrid reactor for breed nuclear fuel and for spent fuel transmutation. The definition and results may be a reference to the other conceptual analysis. (authors)
Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry
Energy Technology Data Exchange (ETDEWEB)
Araneo, Rodolfo; Lovat, Giampiero [DIAEE-Electrical Engineering Division, ' ' Sapienza' ' University of Rome, Via Eudossiana 18, 00184, Rome (Italy); Burghignoli, Paolo [Department of Information Engineering, Electronics and Telecommunications, ' ' Sapienza' ' University of Rome, Via Eudossiana 18, 00184, Rome (Italy); Falconi, Christian [Department of Electronic Engineering, University of Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); CNR IDASC, Via Fosso del Cavaliere, 100, 00133 Rome (Italy)
2012-09-04
The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Seiberg-Witten Map for Superfields on Canonically Deformed N=1, d=4 Superspace
Mikulovicz, D
2004-01-01
In this paper we construct Seiberg-Witten maps for superfields on canonically deformed N=1, d=4 Minkowski and Euclidean superspace. On Minkowski superspace we show that the Seiberg-Witten map is not compatible with locality, (anti)chirality and supersymmetry at the same time. On Euclidean superspace we show that there exists a local, chiral and supersymmetric Seiberg-Witten map for chiral superfields if we take the noncommutativity parameter to be selfdual, and a local, antichiral and supersymmetric Seiberg-Witten map for antichiral superfields if we take the noncommutativity parameter to be antiselfdual, respectively.
Interweaving 3D network with double helical tubes filled by 1D coordination polymer chains.
Yang, E; Zhang, Jian; Li, Zhao-Ji; Gao, Song; Kang, Yao; Chen, Yu-Biao; Wen, Yi-Hang; Yao, Yuan-Gen
2004-10-18
The hydrothermal reaction of mellitic acid, 4,4'-bipydine, and Cu(CH(3)COO)(2).H(2)O gave rise to a novel 3D supramolecular architecture interpenetrated by three types of coordination polymer motifs. Two independent [[Cu(2)(mellitate)(4,4'-bpy)(H(2)O)(2)](2)(-)] 3D polymers incorporating helical substructures were interwoven into a 3D network with double-stranded helical tubes that host 1D linear polymers [Cu(4,4'-bpy)(H(2)O)(4)](2+)](n). PMID:15476343
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.
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.
Quantum Monte Carlo study of a 1D phase-fluctuating condensate
Gils, C; Vernier, A; Hebert, F; Batrouni, G G; Troyer, M
2007-01-01
We study numerically the low temperature behaviour of a 1D Bose gas trapped in an optical lattice. For a sufficient number of particles and weak repulsive interactions, we find a clear regime of temperatures where density fluctuations are negligible but phase fluctuations are considerable, i.e., a quasicondensate. In the weakly interacting limit, our results are in very good agreement with those obtained using a mean-field approximation. In coupling regimes beyond the validity of mean-field approaches, a phase-fluctuating condensate also appears, but the phase-correlation properties are qualitatively different. It is shown that quantum depletion plays an important role.
Controlled switching of intrinsic localized modes in a 1-D antiferromagnet
Wrubel, J P; Sievers, A J
2005-01-01
Nearly steady-state locked intrinsic localized modes (ILMs) in the quasi-1d antiferromagnet (C2H5NH3)2CuCl4 are detected via four-wave mixing emission or the uniform mode absorption. Exploiting the long-time stability of these locked ILMs, repeatable nonlinear switching is observed by varying the sample temperature, and localized modes with various amplitudes are created by modulation of the microwave driver power. This steady-state ILM locking technique could be used to produce energy localization in other atomic lattices.
Monochromatic Neutron Tomography Using 1-D PSD Detector at Low Flux Research Reactor
International Nuclear Information System (INIS)
This paper describes the monochromatic neutron tomography experiment using the 1-D Position Sensitive Neutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work was performed using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principal main aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nm monochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters and features to characterize the system
S-Matrix for Magnons in the D1-D5 System
International Nuclear Information System (INIS)
We show that integrability and symmetries of the near horizon geometry of the D1-D5 system determine the S-matrix for the scattering of magnons in this system completely up to a phase. Using semi-classical methods we evaluate the phase to the leading and to the one-loop approximation in the strong coupling expansion. We then show that the phase obeys the unitarity constraint implied by the crossing relations to the one-loop order. We also verify that the dispersion relation obeyed by these magnons is one-loop exact at strong coupling which is consistent with their BPS nature. (author)
Probing the Quantum State of a 1D Bose Gas Using Off-Resonant Light Scattering
International Nuclear Information System (INIS)
We present a theoretical treatment of coherent light scattering from an interacting 1D Bose gas at finite temperatures. We show how this can provide a nondestructive measurement of the atomic system states. The equilibrium states are determined by the temperature and interaction strength, and are characterized by the spatial density-density correlation function. We show how this correlation function is encoded in the angular distribution of the fluctuations of the scattered light intensity, thus providing a sensitive, quantitative probe of the density-density correlation function and therefore the quantum state of the gas.
Probing the Quantum State of a 1D Bose Gas Using Off-Resonant Light Scattering
Sykes, A. G.; Ballagh, R. J.
2011-12-01
We present a theoretical treatment of coherent light scattering from an interacting 1D Bose gas at finite temperatures. We show how this can provide a nondestructive measurement of the atomic system states. The equilibrium states are determined by the temperature and interaction strength, and are characterized by the spatial density-density correlation function. We show how this correlation function is encoded in the angular distribution of the fluctuations of the scattered light intensity, thus providing a sensitive, quantitative probe of the density-density correlation function and therefore the quantum state of the gas.
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.
Long Distance Transport of Ultracold Atoms using a 1D optical lattice
Schmid, Stefan; Thalhammer, Gregor; Winkler, Klaus; Lang, Florian; Denschlag, Johannes Hecker
2006-01-01
We study the horizontal transport of ultracold atoms over macroscopic distances of up to 20 cm with a moving 1D optical lattice. By using an optical Bessel beam to form the optical lattice, we can achieve nearly homogeneous trapping conditions over the full transport length, which is crucial in order to hold the atoms against gravity for such a wide range. Fast transport velocities of up to 6 m/s (corresponding to about 1100 photon recoils) and accelerations of up to 2600 m/...
Classification of the phases of 1D spin chains with commuting Hamiltonians
Beigi, Salman
2011-01-01
We consider the class of spin Hamiltonians on a 1D chain with periodic boundary conditions that are (i) translational invariant, (ii) commuting and (iii) scale invariant, where by the latter we mean that the ground state degeneracy is independent of the system size. We correspond a directed graph to a Hamiltonian of this form and show that the structure of its ground space can be read from the cycles of the graph. We show that the ground state degeneracy is the only paramete...
Momentum-carrying waves on D1-D5 microstate geometries
Energy Technology Data Exchange (ETDEWEB)
Mathur, Samir D., E-mail: mathur@mps.ohio-state.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Turton, David, E-mail: turton.7@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)
2012-09-21
If one attempts to add momentum-carrying waves to a black string then the solution develops a singularity at the horizon; this is a manifestation of the 'no hair theorem' for black objects. However individual microstates of a black string do not have a horizon, and so the above theorem does not apply. We construct a perturbation that adds momentum to a family of microstates of the extremal D1-D5 string. This perturbation is analogous to the 'singleton' mode localized at the boundary of AdS; to leading order it is pure gauge in the AdS interior of the geometry.
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.
Equilibrium and Kinetics Water Confined in Carbon Nanotube as 1D Lattice Gas
Zhou, X; Iwamoto, M; Zhou, Xin; Li, Cheng-Quan; Iwamoto, Mitsumasa
2002-01-01
A simple 1D lattice gas model is presented, which very well describes the equilibrium and kinetic behaviors of water confined in a thin carbon nanotube found in an atomistic molecular dynamics(MD) simulation {[} Nature {\\bf 414}, 188 (2001) {]}. The model parameters are corresponding to various physical interactions and can be calculated or estimated in statistic mechanics. The roles of every interaction in the water filling, emptying and transporting processes are clearly understood. Our results indicate that the physical picture of the single-file kinetics is very simple.
International Nuclear Information System (INIS)
We use an estimator of quantum criticality based on the entanglement entropy to discuss the ground state properties of the 1D anisotropic Kondo necklace model. We found that the T=0 phase diagram of the model is described by a critical line separating an antiferromagnetic phase from a Kondo singlet state. Moreover we calculate the conformal anomaly on the critical line and obtain that c tends to 0.5 as the thermodynamic limit is reached. Hence we conclude that these transitions belong to Ising universality class being, therefore, second order transitions instead of infinite order as claimed before.
1-D transport model for analysis of expanding radius and full bore startup of tokamak plasmas
International Nuclear Information System (INIS)
This report describes the physics models and numerical algorithms that have been used in the WHIST one-dimensional (1-D) transport code to study expanding radius vs full bore startup scenarios for tokamak plasmas. The phase of the tokamak discharge that is modeled is the time segment following plasma breakdown (and initial current channel formation) up to ignition. The code has been applied to the Oak Ridge National Laboratory (ORNL) The Next Step (TNS) reference design. The various physics models are presented, and references are made to benchmarking calculations when they exist
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; Kutter, Jörg Peter; Mogensen, Klaus Bo
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 ...
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.
Identification of Regions Critical for the Integrity of the TSC1-TSC2-TBC1D7 Complex
Santiago Lima, Arthur Jorge; Hoogeveen-Westerveld, Marianne; Nakashima, Akio; Maat-Kievit, Anneke; van den Ouweland, Ans; Halley, Dicky; Kikkawa, Ushio; Nellist, Mark
2014-01-01
The TSC1-TSC2-TBC1D7 complex is an important negative regulator of the mechanistic target of rapamycin complex 1 that controls cell growth in response to environmental cues. Inactivating TSC1 and TSC2 mutations cause tuberous sclerosis complex (TSC), an autosomal dominant disorder characterised by the occurrence of benign tumours in various organs and tissues, notably the brain, skin and kidneys. TBC1D7 mutations have not been reported in TSC patients but homozygous inactivation of TBC1D7 cau...
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.
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.
Direct Observation of Chiral Topological Solitons in 1D Charge-Density Waves
Kim, Tae-Hwan; Cheon, Sangmo; Lee, Sung-Hoon; Yeom, Han Woong
2015-03-01
Macroscopic and classical solitons are easily and ubiquitously found, from tsunami to blood pressure pulses, but those in microscopic scale are hard to observe. While the existence of such topological solitons were predicted theoretically and evidenced indirectly by the transport and infrared spectroscopy measurements, the direct observation has been hampered by their high mobility and small dimension. In this talk, we show direct observation of topological solitons in the quasi-1D charge-density wave (CDW) ground state of indium atomic wires, which are consisting of interacting double Peierls chains. Such solitons exhibit a characteristic spatial variation of the CDW amplitudes as expected from the electronic structure. Furthermore, these solitons have an exotic hidden topology originated by topologically different 4-fold degenerate CDW ground states. Their exotic topology leads to the chirality of 1D topological solitons through interaction between two solitons in the double Peierls chains. Detailed scanning tunneling microscopy and spectroscopy reveal their chiral nature at the atomic scale. This work paves the avenue toward the microscopic exploitation of the peculiar properties of nanoscale chiral solitons.
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.
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.
Assessment of improved root growth representation in a 1-D, field scale crop model
Miltin Mboh, Cho; Gaiser, Thomas; Ewert, Frank
2015-04-01
Many 1-D, field scale crop models over-simplify root growth. The over-simplification of this "hidden half" of the crop may have significant consequences on simulated root water and nutrient uptake with a corresponding reflection on the simulated crop yields. Poor representation of root growth in crop models may therefore constitute a major source of uncertainty propagation. In this study we assess the effect of an improved representation of root growth in a model solution of the model framework SIMPLACE (Scientific Impact assessment and Modeling PLatform for Advanced Crop and Ecosystem management) compared to conventional 1-D approaches. The LINTUL5 crop growth model is coupled to the Hillflow soil water balance model within the SIMPLACE modeling framework (Gaiser et al, 2013). Root water uptake scenarios in the soil hydrological simulator Hillflow (Bronstert, 1995) together with an improved representation of root growth is compared to scenarios for which root growth is simplified. The improvement of root growth is achieved by integrating root growth solutions from R-SWMS (Javaux et al., 2008) into the SIMPLACE model solution. R-SWMS is a three dimensional model for simultaneous modeling of root growth, soil water fluxes and solute transport and uptake. These scenarios are tested by comparing how well the simulated water contents match with the observed soil water dynamics. The impacts of the scenarios on above ground biomass and wheat grain are assessed
Evaluation of 2 1-D cloud models for the analysis of VAS soundings
Emmitt, G. D.
1984-01-01
Evaluation of the satellite Visual Infrared Spin Scan Radiometer Atmospheric Sounder (VISSR) has begun to document several of its critical shortcomings as far as numerical cloud models are concerned: excessive smoothing of thermal inversions; imprecise measurement of boundary layer moisture; and tendency to exaggerate atmospheric stability. The sensitivity of 1-D cloud models to their required inputs is stressed with special attention to those parameters obtained from atmospheric soundings taken by the VAS or rawinsonde. In addition to performing model experiments using temperature and moisture profiles having the general characteristics of VAS soundings, standard input sensitivity tests were made and 1-D model performance was compared with observations and the results of a 2-D model experiment using AVE/VAS data (Atmospheric Variability Experiment). Although very encouraging, the results are not sufficient to make any specific conclusions. In general, the VAS soundings are likely to be inadequate to provide the cloud base (and subcloud layer) information needed for inputs to current cumulus models. Above cloud base, the tendency to exaggerate the stability of the atmosphere requires solution before meaningful model experiments are run.
Comparison of 1D, 2D and 3D quench onset simulations
International Nuclear Information System (INIS)
Measured and simulated minimum quench energies (MQE) for short samples are doubtful when estimating disturbance tolerance of an impregnated superconducting magnet. If measurements are performed at liquid cryogen, the cooling provided by the cryogen causes MQE to be high. At a conduction-cooled system, the transverse heat conduction is neglected causing low MQE. Even though these conditions can be artificially brought closer to the ones in an impregnated magnet, it is difficult to estimate by short-sample measurement the MQE of a superconducting coil. These similar difficulties are present at simulations. On the other hand, 1D and 2D measurements and simulations can be used, e.g., to compare wires or consider effect of insulation layer thickness, but according to the results only in a rough quantitative way. In this paper, we compare MQE and normal zone propagation velocity simulations of an MgB2 wire with 1D, 2D and 3D finite element method models to focus on the different results given by the models employing different dimensions.
Quasi-1D physics in metal-organic frameworks: MIL-47(V) from first principles.
Vanpoucke, Danny E P; Jaeken, Jan W; De Baerdemacker, Stijn; Lejaeghere, Kurt; Van Speybroeck, Veronique
2014-01-01
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 Å(3). The transition pressure of the pressure-induced large-pore-to-narrow-pore phase transition is calculated to be 82 MPa and 124 MPa for systems with ferromagnetic and antiferromagnetic chains, respectively. For a mixed system, the transition pressure is found to be a weighted average of the ferromagnetic and antiferromagnetic transition pressures. Mapping DFT energies onto a simple-spin Hamiltonian shows both the intra- and inter-chain coupling to be antiferromagnetic, with the latter coupling constant being two orders of magnitude smaller than the former, suggesting the MIL-47(V) to present quasi-1D behavior. The electronic structure of the different spin configurations is investigated and it shows that the band gap position varies strongly with the spin configuration. The valence and conduction bands show a clear V d-character. In addition, these bands are flat in directions orthogonal to VO6 chains, while showing dispersion along the the direction of the VO6 chains, similar as for other quasi-1D materials. PMID:25383285
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.
Diffusive public goods and coexistence of cooperators and cheaters on a 1D lattice.
Scheuring, István
2014-01-01
Many populations of cells cooperate through the production of extracellular materials. These materials (enzymes, siderophores) spread by diffusion and can be applied by both the cooperator and cheater (non-producer) cells. In this paper the problem of coexistence of cooperator and cheater cells is studied on a 1D lattice where cooperator cells produce a diffusive material which is beneficial to the individuals according to the local concentration of this public good. The reproduction success of a cell increases linearly with the benefit in the first model version and increases non-linearly (saturates) in the second version. Two types of update rules are considered; either the cooperative cell stops producing material before death (death-production-birth, DpB) or it produces the common material before it is selected to die (production-death-birth, pDB). The empty space is occupied by its neighbors according to their replication rates. By using analytical and numerical methods I have shown that coexistence of the cooperator and cheater cells is possible although atypical in the linear version of this 1D model if either DpB or pDB update rule is assumed. While coexistence is impossible in the non-linear model with pDB update rule, it is one of the typical behaviors in case of the non-linear model with DpB update rule. PMID:25025985
Pharmacological challenge with a serotonin 1D agonist in alcohol dependence
Directory of Open Access Journals (Sweden)
Pienaar Willie
2005-08-01
Full Text Available Abstract Background Both animal and clinical studies have implicated serotonergic dysfunction in the pathogenesis of alcohol abuse and dependence. However the exact mechanisms involved remain unknown. Theoretically, low serotonin promotes alcohol seeking behavior. Sumatriptan is a serotonin1D agonist. It is postulated that sumatriptan's agonism at this terminal autoreceptor increases negative feedback, creating a net effect of decreased serotonergic neurotransmission. Administration of sumatriptan should therefore produce a craving for alcohol and the desire to drink. Methods Fifteen patients with alcohol dependence who had undergone detoxification were recruited. Sumatriptan (100 mg and placebo was administered in cross-over fashion on 2 separate days 72 hours apart. Both patients and raters were blind to all treatments. Patients were assessed on the following scales at -30, 0, 30, 90, 150 and 210 minutes: A 6-item scale designed to rate the patient's intention to drink; The Sensation Scale; a 13-item affect analog scale designed to rate the pattern and extent of emotional changes; and an 8-item scale designed to rate the patient's craving for alcohol Results No significant differences were found between the placebo and sumatriptan groups and no significant cross over effects were found. Conclusion The general lack of efficacy of sumatriptan in producing alcohol-like symptoms or a desire to drink alcohol may suggest that the 5HT1D receptor plays little role in the pathophysiology of alcoholism.
(7)Li in situ 1D NMR imaging of a lithium ion battery.
Klamor, S; Zick, K; Oerther, T; Schappacher, F M; Winter, M; Brunklaus, G
2015-02-14
The spatial distribution of charge carriers in lithium ion batteries during current flow is of fundamental interest for a detailed understanding of transport properties and the development of strategies for future improvements of the electrolyte-electrode interface behaviour. In this work we explored the potential of (7)Li 1D in situ NMR imaging for the identification of concentration gradients under constant current load in a battery cell. An electrochemical cell based on PTFE body and a stack of glass microfiber discs that are soaked with a technically relevant electrolyte suitable for high-temperature application and squeezed between a Li metal and a nano-Si-graphite composite electrode was assembled to acquire (7)Li 1D in situ NMR profiles with an improved NMR pulse sequence as function of time and state of charge, thereby visualizing the course of ion concentration during charge and discharge. Surface localized changes of Li concentration were attributed to processes such as solid electrolyte interphase formation or full lithiation of the composite electrode. The method allows the extraction of lithium ion transport properties. PMID:25578436
In2-XO3-Y 1D perpendicular nanostructure arrays as ultraviolet detector
Goswami, Tamal; Mondal, Aniruddha; Singh, Pankaj; Choudhuri, Bijit
2015-10-01
The 1D perpendicular In2-xO3-y nanostructure arrays have been synthesized by using glancing angle deposition (GLAD) technique. A low deposition rate of 0.5 A°/S produced highly porous structure. The characteristics of junction defects and photocurrent were measured to verify the detector performance. The junction capacitance and charge retention due to presence of trap states in the device decreased with an increase in frequency. The high value of Dit˜ 5.5 × 1017 cm-2 eV-1 was calculated for the device. The detector processes low ideality factor of ˜2.04 at 300 K. The maximum photo responsivity of ˜15 A/W and internal gain of ˜47 were measured for the 1D In2-xO3-y based detector at ˜380 nm in UV region. The device shows very high current density ˜20 A/cm2 (-2 V, 300 K) under dark, which deflects to 32 A/cm2 due to illumination. Under white light on/off switching irradiation, the device operates with rise time of 1.9 s and decay time of 2.3 s. Therefore In2-xO3-y nanostructure arrays can be used as sensitive UV light detector.
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)
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
1-D Air-snowpack modeling of atmospheric nitrous acid at South Pole during ANTCI 2003
Directory of Open Access Journals (Sweden)
W. Liao
2008-12-01
Full Text Available A 1-D air-snowpack model of HONO has been developed and constrained by observed chemistry and meteorology data. The 1-D model includes molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate and interstitial air HONO photolysis. Photolysis of nitrate is important as a dominant HONO source inside the snowpack, however, the observed HONO emission from the snowpack was triggered mainly by the equilibrium between quasi liquid layer nitrite and firn air HONO deep down the snow surface (i.e. 30 cm below snow surface. The high concentration of HONO in the firn air is subsequently transported above the snowpack by diffusion and windpumping. The model uncertainties come mainly from lack of measurements and the interpretation of the QLL properties based on the bulk snow measurements. One critical factor is the ionic strength of QLL nitrite, which is estimated here by the bulk snow pH, nitrite concentration, and QLL to bulk snow volume ratio.
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.
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...
The eigenvalue equation for a 1-D Hamilton function in deformation quantization
International Nuclear Information System (INIS)
The eigenvalue equation has been found for a Hamilton function in a form independent of the choice of a potential. This Letter proposes a modified Fedosov construction on a flat symplectic manifold. Necessary and sufficient conditions for solutions of an eigenvalue equation to be Wigner functions of pure states are presented. The 1-D harmonic oscillator eigenvalue equation in the coordinates time and energy is solved. A perturbation theory based on the variables time and energy is elaborated. -- Highlights: ? We propose a method of solution of the ?-genvalue equation for a 1-D Hamiltonian by the change of coordinates (q,p)?(time,energy). ? A covariant form of the ?-genvalue equation for Hamiltonian is presented. ? Continuity of a Wigner function of a pure state with respect to q and p has been proved. ? Three criteria for an arbitrary function to be a Wigner function of a pure state are presented and proved. ? A perturbation theory based on the variables time and energy is elaborated.
CD1d- and MR1-Restricted T Cells in Sepsis.
Szabo, Peter A; Anantha, Ram V; Shaler, Christopher R; McCormick, John K; Haeryfar, S M Mansour
2015-01-01
Dysregulated immune responses to infection, such as those encountered in sepsis, can be catastrophic. Sepsis is typically triggered by an overwhelming systemic response to an infectious agent(s) and is associated with high morbidity and mortality even under optimal critical care. Recent studies have implicated unconventional, innate-like T lymphocytes, including CD1d- and MR1-restricted T cells as effectors and/or regulators of inflammatory responses during sepsis. These cell types are typified by invariant natural killer T (iNKT) cells, variant NKT (vNKT) cells, and mucosa-associated invariant T (MAIT) cells. iNKT and vNKT cells are CD1d-restricted, lipid-reactive cells with remarkable immunoregulatory properties. MAIT cells participate in antimicrobial defense, and are restricted by major histocompatibility complex-related protein 1 (MR1), which displays microbe-derived vitamin B metabolites. Importantly, NKT and MAIT cells are rapid and potent producers of immunomodulatory cytokines. Therefore, they may be considered attractive targets during the early hyperinflammatory phase of sepsis when immediate interventions are urgently needed, and also in later phases when adjuvant immunotherapies could potentially reverse the dangerous state of immunosuppression. We will highlight recent findings that point to the significance or the therapeutic potentials of NKT and MAIT cells in sepsis and will also discuss what lies ahead in research in this area. PMID:26322041
Bogoliubov coefficients for the twist operator in the D1D5 CFT
International Nuclear Information System (INIS)
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
Testing a 1-D Analytical Salt Intrusion Model and the Predictive Equation in Malaysian Estuaries
Gisen, Jacqueline Isabella; Savenije, Hubert H. G.
2013-04-01
Little is known about the salt intrusion behaviour in Malaysian estuaries. Study on this topic sometimes requires large amounts of data especially if a 2-D or 3-D numerical models are used for analysis. In poor data environments, 1-D analytical models are more appropriate. For this reason, a fully analytical 1-D salt intrusion model, based on the theory of Savenije in 2005, was tested in three Malaysian estuaries (Bernam, Selangor and Muar) because it is simple and requires minimal data. In order to achieve that, site surveys were conducted in these estuaries during the dry season (June-August) at spring tide by moving boat technique. Data of cross-sections, water levels and salinity were collected, and then analysed with the salt intrusion model. This paper demonstrates a good fit between the simulated and observed salinity distribution for all three estuaries. Additionally, the calibrated Van der Burgh's coefficient K, Dispersion coefficient D0, and salt intrusion length L, for the estuaries also displayed a reasonable correlations with those calculated from the predictive equations. This indicates that not only is the salt intrusion model valid for the case studies in Malaysia but also the predictive model. Furthermore, the results from this study describe the current state of the estuaries with which the Malaysian water authority in Malaysia can make decisions on limiting water abstraction or dredging. Keywords: salt intrusion, Malaysian estuaries, discharge, predictive model, dispersion
Performance studies on high pressure 1-D position sensitive neutron detectors
Indian Academy of Sciences (India)
S S Desai; A M Shaikh
2008-11-01
The powder diffractometer and Hi-Q diffractometer at Dhruva reactor make use of five identical 1-D position sensitive detectors (PSDs) to scan scattering angles in the range 3° to 140°. In order to improve the overall throughput of these spectrometers, it is planned to install a bank of 15 high-efficiency and high-resolution PSDs arranged in three layers with five PSDs in each layer. With each high pressure PSD (3He 10 bar + Kr 2 bar) showing the efficiency gain of 1.8 at 1.2 Å, detector bank is expected to show overall gain of 5.5 times the present detection efficiency and reduction in data collection time by equivalent factor. The 1-D PSDs are developed in batches of five, and are characterized so that all PSDs operate at uniform parameters such as position resolution, uniformity of efficiency and linearity of response. Position spectrum indicates the differential position resolution to be $\\sim 1$ mm and integral position resolution to be 3–4 mm. Broadening of position spectrum at the extreme end of sensitive length of PSD is analysed using fine shift of the beam. Dependence of position resolution and dynamic range of output pulse on the input impedance of pre-amplifier is also presented.
Wysocka-?o?opa, Monika; Winkler, Krzysztof
2015-12-01
Composites of polypyrrole and one-dimensional iridium complex crystals [(C2H5)4N]0.55[IrCl2(CO)2] were prepared by in situ two-step electrodeposition. Initially, iridium complex crystals were formed during [IrCl2(CO)2]- complex oxidation. Next, pyrrole was electropolymerized on the surface of the iridium needles. The morphology of the composite was investigated by scanning and transmission electron microscopy. At positive potentials, the iridium complex crystals and the polypyrrole were oxidized. In aprotic solvents, oxidation of the iridium complex crystals resulted in their dissolution. In water containing tetra(n-butyl)ammonium chlorides, the 1-D iridium complex crystals were reversibly oxidized. The product of the iridium complex oxidation remained on the electrode surface in crystalline form. The iridium complex needles significantly influenced the redox properties of the polymer. The polypyrrole involved electrode processes become more reversible in presence of crystals of iridium complex. The current of polypyrrole oxidation was higher compared to that of pure polypyrrole and the capacitance properties of the polymer were significantly enhanced. A specific capacitance as high as 590 F g-1 was obtained for a composite of polypyrrole and 1-D crystals of the iridium complex in water containing tetra(n-butyl)ammonium chloride. This value is approximately twice as high as the capacitance of the pure polymer deposited onto the electrode surface.
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...
1989-01-01
When Enerpro, Inc. president, Frank J. Bourbeau, attempted to file a patent on a system for synchronizing a wind generator to the electric utility grid, he discovered Marshall Space Flight Center's Frank Nola's power factor controller. Bourbeau advanced the technology and received a NASA license and a patent for his Auto Synchronous Controller (ASC). The ASC reduces generator "inrush current," which occurs when large generators are abruptly brought on line. It controls voltage so the generator is smoothly connected to the utility grid when it reaches its synchronous speed, protecting the components from inrush current damage. Generator efficiency is also increased in light winds by applying lower than rated voltage. Wind energy is utilized to drive turbines to generate electricity for utility companies.
Ds1*(2860) and Ds3*(2860): candidates for 1D charmed-strange mesons
International Nuclear Information System (INIS)
Newly observed two charmed-strange resonances, Ds1*(2860) and Ds3*(2860), are investigated by calculating their Okubo-Zweig-Iizuka-allowed strong decays, which shows that they are suitable candidates for the 13D1 and 13D3 states in the charmed-strange meson family. Our study also predicts other main decay modes of Ds1*(2860) and Ds3*(2860), which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of Ds1*(2860) and Ds3*(2860), i.e., 1D(2-) and 1D'(2-), are predicted in this work, which are still missing at present. The experimental search for the missing 1D(2-) and 1D'(2-) charmed-strange mesons is an intriguing and challenging task for further experiments. (orig.)
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.
Non-linear bond-operator theory and 1/d expansion for coupled-dimer magnets I: Paramagnetic phase
Joshi, Darshan G.; Coester, Kris; Schmidt, Kai P.; Vojta, Matthias
2014-01-01
For coupled-dimer Heisenberg magnets, a paradigm of magnetic quantum phase transitions, we develop a systematic expansion in 1/d, the inverse number of space dimensions. The expansion employs a formulation of the bond-operator technique and is based on the observation that a suitably chosen product-state wavefunction yields exact zero-temperature expectation values of local observables in the d->infty limit, with corrections vanishing as 1/d. We demonstrate the approach for ...
Gangjee, Aleem; Zhao, Ying; Michael A. Ihnat; Jessica E. Thorpe; Bailey-Downs, Lora C.; Kisliuk, Roy L.
2012-01-01
We designed, synthesized and evaluated thirteen novel tricyclic indeno[2,1-d]pyrimidines as RTK inhibitors. These analogues were synthesized via a Dieckmann condensation of 1,2-phenylenediacetonitrile followed by cyclocondensation with guanidine carbonate to afford the 2-amino-3,9-dihydro-indeno[2,1-d]pyrimidin-4-one. Sulfonation of the 4-position followed by displacement with appropriately substituted anilines afforded the target compounds. These compounds were potent inhibitors of platelet-...
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.
King, Margaret
The first section of this paper deals with the attempts within the framework of transformational grammar to make semantics a systematic part of linguistic description, and outlines the characteristics of the generative semantics position. The second section takes a critical look at generative semantics in its later manifestations, and makes a case…
Generating functions for generating trees
Banderier, C; Gardy, D; Bousquet-Mélou, M; Denise, A; Gouyou-Beauchamps, D; Banderier, Cyril; Flajolet, Philippe; Gardy, Daniele; Bousquet-Melou, Mireille; Denise, Alain; Gouyou-Beauchamps, Dominique
2002-01-01
Certain families of combinatorial objects admit recursive descriptions in terms of generating trees: each node of the tree corresponds to an object, and the branch leading to the node encodes the choices made in the construction of the object. Generating trees lead to a fast computation of enumeration sequences (sometimes, to explicit formulae as well) and provide efficient random generation algorithms. We investigate the links between the structural properties of the rewriting rules defining such trees and the rationality, algebraicity, or transcendence of the corresponding generating function.
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...
Statistics of scattered photons from a driven three-level emitter in 1D open space
International Nuclear Information System (INIS)
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.
Transferable Integrated Optical SU8 Devices: From Micronic Waveguides to 1D-Nanostructures
Directory of Open Access Journals (Sweden)
Nolwenn Huby
2015-04-01
Full Text Available We report on optical components for integrated optics applications at the micro- and nanoscale. Versatile shapes and dimensions are achievable due to the liquid phase processability of SU8 resist. On the one hand, by adjusting the UV-lithography process, waveguiding structures are patterned and released from their original substrate. They can be replaced on any other substrate and also immerged in liquid wherein they still show off efficient light confinement. On the other hand, filled and hollow 1D-nanostructures are achievable by the wetting template method. By exploiting the large range of available SU8 viscosities, nanowires of diameter ranging between 50 nm and 240 nm, as well as nanotubes of controllable wall thickness are presented. Optical injection, propagation, and coupling in such nanostructures are relevant for highly integrated devices.
Duality in 2+1D Quantum Elasticity: superconductivity and Quantum Nematic Order
Zaanen, J; Mukhin, S I
2004-01-01
The generalization of the Nelson-Halperin-Young theory of 2D melting to the dynamical 2+1D quantum case is presented. The bosonic quantum crystal dualizes in superfluids or superconductors exhibiting nematic liquid crystalline orders, corresponding with bose condensates of dislocations exhibiting a dual shear Meissner-Higgs mechanism. The topologically ordered nematic phase suggested by Lammert, Toner and Rokshar finds a simple interpretation in this framework. The ordered nematic is a true quantum phase: the dynamical glide principle interferes with the effect that the phonon spectrum of the crystal re-emerges in the direction orthogonal to the director. Novel insights follow from the duality on the fundamental nature of superfluidity and superconductivity. The superfluid can be viewed as an elastic medium having lost its rigidity against shear stresses. Upon dualizing the electrically charged crystal the electromagnetic Meissner phase is recovered, showing peculiar screening current oscillations when the sh...
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.
Facile hydrothermal route to the controlled synthesis of -Fe2O3 1-D nanostructures
Indian Academy of Sciences (India)
Lixia Yang; Ying Liang; Hou Chen; Lingyan Kong; Wei Jiang
2008-12-01
Single-crystalline -Fe2O3 1-D nanostructures can be obtained via a facile one-step hydrothermal synthetic route. It was found that the introduction of SnCl4 played a key role in determining the composition and morphology of -Fe2O3. The addition of SnCl4 favours the formation of Fe2O3 rather than FeOOH, and the morphology can be tuned from nanorod to double-shuttle as the increase of SnCl4 concentration. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and selectedarea electron diffraction (SAED). This simple method does not need any seed, catalyst, or template, thus is promising for large-scale and low-cost production.
Specific heat of an S=1 quasi-1D bond alternating antiferromagnet in a magnetic field
International Nuclear Information System (INIS)
We report the results of specific heat measurements in a magnetic field on single crystal samples of the S=1 quasi-1D bond alternating antiferromagnet Ni(C9H24N4)NO2(ClO4). The compound has the singlet ground state with an excitation energy gap and the gap closes by application of magnetic field (Hc). We observed a sharp peak corresponding to the long-range ordering above Hc both parallel and perpendicular to the chain at low temperatures. The temperature-magnetic field phase diagram is discussed in comparison with those of the Haldane system Ni(C5H14N2)2N3(PF6)
Specific heat of an S=1 quasi-1D bond alternating antiferromagnet in a magnetic field
Energy Technology Data Exchange (ETDEWEB)
Tateiwa, Naoyuki; Hagiwara, Masayuki; Aruga-Katori, Hiroko; Kobayashi, T.C
2003-05-01
We report the results of specific heat measurements in a magnetic field on single crystal samples of the S=1 quasi-1D bond alternating antiferromagnet Ni(C{sub 9}H{sub 24}N{sub 4})NO{sub 2}(ClO{sub 4}). The compound has the singlet ground state with an excitation energy gap and the gap closes by application of magnetic field (H{sub c}). We observed a sharp peak corresponding to the long-range ordering above H{sub c} both parallel and perpendicular to the chain at low temperatures. The temperature-magnetic field phase diagram is discussed in comparison with those of the Haldane system Ni(C{sub 5}H{sub 14}N{sub 2}){sub 2}N{sub 3}(PF{sub 6})
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)
Light transport behaviours in quasi-1D disordered waveguides composed of random photonic lattices
Xu, Yuchen; Lin, Yujun; Zhu, Heyuan
2015-01-01
We present a numerical study on the light transport properties which are modulated by the disorder strength in quasi-one-dimensional disordered waveguide which consists of periodically arranged scatterers with random dielectric constant. The transport mean free path is found to stay inversely proportional to the square of the relative fluctuation of the dielectric constant as in the 1D and 2D cases but with . The transport properties of light through a sample with a fixed size can be modulated from ballistic to localized regime as well, and a generalized scaling function is defined to determine the light transport status in such a sample. The calculation of the diffusion coefficient and the energy density profile of the most transmitted eigenchannel clearly exhibits the transition of transport behaviour from diffusion to localization.
Fluid friction and wall viscosity of the 1D blood flow model
Wang, Xiao-Fei; Matsukawa, Mami; Ghigo, Arthur; Lagrée, Pierre-Yves; Fullana, Jose-Maria
2015-01-01
We study the behavior of the pulse waves of water into a flexible tube for application to blood flow simulations. In pulse waves both fluid friction and wall viscosity are damping factors, and difficult to evaluate separately. In this paper, the coefficients of fluid friction and wall viscosity are estimated by fitting a nonlinear 1D flow model to experimental data. In the experimental setup, a distensible tube is connected to a piston pump at one end and closed at another end. The pressure and wall displacements are measured simultaneously. A good agreement between model predictions and experiments was achieved. For amplitude decrease, the effect of wall viscosity on the pulse wave has been shown as important as that of fluid viscosity.
Quantum phase transition of light in a 1-D photon-hopping-controllable resonator array
Wu, Chun-Wang; Deng, Zhi-Jiao; Dai, Hong-Yi; Chen, Ping-Xing; Li, Cheng-Zu
2011-01-01
We give a concrete experimental scheme for engineering the insulator-superfluid transition of light in a one-dimensional (1-D) array of coupled superconducting stripline resonators. In our proposed architecture, the on-site interaction and the photon hopping rate can be tuned independently by adjusting the transition frequencies of the charge qubits inside the resonators and at the resonator junctions, respectively, which permits us to systematically study the quantum phase transition of light in a complete parameter space. By combining the techniques of photon-number-dependent qubit transition and fast read-out of the qubit state using a separate low-Q resonator mode, the statistical property of the excitations in each resonator can be obtained with a high efficiency. An analysis of the various decoherence sources and disorders shows that our scheme can serve as a guide to coming experiments involving a small number of coupled resonators.
Ground state of the quasi-1D correlated electronic system BaVS{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Foury-Leylekian, Pascale, E-mail: pascale.foury@u-psud.fr [Laboratoire de Physique des Solides, UMR 8502, CNRS, Universite Paris-Sud, F- 91405, Orsay Cedex (France); Leininger, Philippe [Max-Planck-Insitut furFestkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany); Ilakovac, Vita [LCP-MR, Universite Pierre et Marie Curie, UMR 7614, CNRS, F-75321 Paris, France and Universite Cergy-Pontoise, F-95031, Cergy-Pontoise (France); Joly, Yves [Institut Neel, CNRS-UJF, BP 166, F-38042 Grenoble Cedex 9 (France); Bernu, Sylvain; Fagot, Sebastien; Pouget, Jean-Paul [Laboratoire de Physique des Solides, UMR 8502, CNRS, Universite Paris-Sud, F- 91405, Orsay Cedex (France)
2012-06-01
In this paper we review the salient features of the different instabilities exhibited by the quasi-1D system BaVS{sub 3} and show that there is a subtle interplay between the different phases stabilized. The analysis of the Peierls instability shows that the mobile dz Superscript-Two electrons are more localized than calculated because of their strong correlation with the localized e(t{sub 2g}) electrons. The complex AF magnetic structure of BaVS{sub 3} incorporates the magnetization of the e(t{sub 2g}) electrons with the Peierls pairing of the dz Superscript-Two electrons into magnetic singlets. Finally, we propose that the zig-zag disorder remaining after an incomplete orthorhombic phase transition could change the sign of the magnetic coupling and thus help to stabilize the canted ferromagnetism observed in non stoichiometric BaVS{sub 3-{delta}} and Sr and Ba substituted compounds.
Ground state of the quasi-1D correlated electronic system BaVS3
International Nuclear Information System (INIS)
In this paper we review the salient features of the different instabilities exhibited by the quasi-1D system BaVS3 and show that there is a subtle interplay between the different phases stabilized. The analysis of the Peierls instability shows that the mobile dz² electrons are more localized than calculated because of their strong correlation with the localized e(t2g) electrons. The complex AF magnetic structure of BaVS3 incorporates the magnetization of the e(t2g) electrons with the Peierls pairing of the dz² electrons into magnetic singlets. Finally, we propose that the zig-zag disorder remaining after an incomplete orthorhombic phase transition could change the sign of the magnetic coupling and thus help to stabilize the canted ferromagnetism observed in non stoichiometric BaVS3?? and Sr and Ba substituted compounds.
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
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.
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...
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
Continuous 1D-Metallic Microfibers Web for Flexible Organic Solar Cells.
Hong, Kihyon; Ham, Juyoung; Kim, Byoung-Joon; Park, Jae Yong; Lim, Dong Chan; Lee, Joo Yul; Lee, Jong-Lam
2015-12-16
We report the use of a continuous 1D-metallic microfibers web (MFW) as transparent electrode for organic solar cells (OSCs). The MFW electrode can be produced with a process that involves simple electrospinning and wet etching of metal thin film. Au MFW exhibits a maximum optical transmittance of 90.8% (at 15 ?/sq of the sheet resistance) and excellent mechanical flexibility. The MFW structure has an average width in the range from 4 to 6 ?m and a junction-free structure, resulting in very smooth surface roughness. The OSCs with Au MFW electrode exhibited a higher power conversion efficiency (PCE) of 3.50% than the device with an indium tin oxide electrode (PCE = 3.20%). The optical modeling calculation showed that the Au MFW electrode induced light scattering and improved the light absorption in the active layer, resulting in an improved PCE in the OSCs. PMID:26580701
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.
Liu, Jian-Jun; Guan, Ying-Fang; Chen, Yong; Lin, Mei-Jin; Huang, Chang-Cang; Dai, Wen-Xin
2015-10-21
Lone pair-? interaction is an important but less studied binding force. Generally, it is too weak to influence the physical properties of supramolecular systems. Herein we reported the first example exhibiting the impact of lone pair-? interactions on photochromic properties of naphthalene diimide based coordination networks. In three isostructural 1-D networks, [(DPNDI)ZnX2] (DPNDI = N,N-di(4-pyridyl)-1,4,5,8-naphthalene diimide, X = Cl for 1, X = Br for 2 and X = I for 3), they exhibit different electron-transfer photochromic behaviors due to different lone pair-? interactions between the capped halogen atoms and electron-deficient DPNDI moieties. Specifically, 1 and 2 but not 3 are photochromic, which is attributed to a stronger lone pair-? interaction in 3 than those in 1 and 2. This study anticipates breaking a new path for designing novel photochromic materials through such unnoticeable supramolecular interactions. PMID:26388114
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.
The Response Matrix Discrete Ordinates Solution to the 1D Radiative Transfer Equation
Ganapol, B D
2014-01-01
The discrete ordinates method (DOM) of solution to the 1D radiative transfer equation has been an effective method of solution for nearly 70 years. During that time, the method has experienced numerous improvements as numerical and computational techniques have become more powerful and efficient. Here, we again consider the analytical solution to the discrete radiative transfer equation in a homogeneous medium by proposing a new, and consistent, form of solution that improves upon previous forms. Aided by a Wynn-epsilon convergence acceleration, its numerical evaluation can achieve extreme accuracy as demonstrated by comparison with published benchmarks. Finally, we readily extend the solution to a heterogeneous medium through the star product formulation producing a novel benchmark for closed form Henyey-Greenstein scattering as an example.
Application Of Hough Transform And Sub-Pixel Edge Detection In 1-D Barcode Scanning
Directory of Open Access Journals (Sweden)
HARSH KAPADIA, ALPESH PATEL
2013-06-01
Full Text Available This paper predominantly emphases on two algorithms Hough Transform and the Sub-Pixel Edge Detection and their application on 1-Dimensional barcode scanning. The system is meant to verify Barcode on-line. It primarily focuses on two aspects of barcode verification. One is two detect the angle if barcode is skewed in the image and correct the same. The other is to detect the edges of a barcode in real time blurred image using sub-pixel edge detection. First of all we have explained the basic theory of 1-D barcode that was used i.e. EAN-13. Then the Hough Transform and Sub-Pixel Edge Detection are explained in detail. After that I have explained the need of both the algorithm in barcode verification. The paper also embraces MATLAB implementation steps of the system including both this algorithms with results.
Ampilogov, Dmitrii
2015-01-01
We consider a boundary problem for 1D electrodynamics modeling of a pulse propagation in a metamaterial medium. We build and apply projecting operators to a Maxwell system in time domain that allows to split the linear propagation problem to directed waves for a material relations with general dispersion. Matrix elements of the projectors act as convolution integral operators. For a weak nonlinearity we generalize the linear results still for arbitrary dispersion and derive the system of interacting right/left waves with combined (hybrid) amplitudes. The result is specified for the popular metamaterial model with Drude formula for both permittivity and permeability coefficients. We also discuss and investigate stationary solutions of the system related to some boundary regimes.
Computing 1-D atomic densities in macromolecular simulations: The density profile tool for VMD
Giorgino, Toni
2014-01-01
Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment with the ability to interactively compute and visualize 1-D projections of various density functions of molecular models. We describe how the plugin is used to perform computations both via a graphical interface and programmatically. Results are presented for realistic examples, all-atom bilayer models, showing how mass and electron densities readily provide measurements such as membrane thickness, location of structural elements, and how they compare to X-ray diffraction experiments.
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). Theoretical Div. and Center for Nonlinear Studies; Bondyopadhaya, Nilanjan [Visva-Bharati University, Santiniketan (India). Integrated Science Education and Research Centre
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.
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.
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.
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)
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 ...
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...
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.
Computing 1-D atomic densities in macromolecular simulations: the Density Profile Tool for VMD
Giorgino, Toni
2013-01-01
Molecular dynamics simulations have a prominent role in biophysics and drug discovery due to the atomistic information they provide on the structure, energetics and dynamics of biomolecules. Specialized software packages are required to analyze simulated trajectories, either interactively or via scripts, to derive quantities of interest and provide insight for further experiments. This paper presents the Density Profile Tool, a package that enhances the Visual Molecular Dynamics environment with the ability to interactively compute and visualize 1-D projections of various density functions of molecular models. We describe how the plugin is used to perform computations both via a graphical interface and programmatically. Results are presented for realistic examples, all-atom bilayer models, showing how mass and electron densities readily provide measurements such as membrane thickness, location of structural elements, and how they compare to X-ray diffraction experiments.
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.
Exact solutions for correlation functions in some 1+1 D field theories with boundary
Freed, D E
1995-01-01
We consider 1+1 D theories which are free everywhere except for cosine and magnetic interactions on the boundary. These theories arise in dissipative quantum systems, open string theory, and, in special cases, tunneling in quantum Hall systems. These boundary systems satisfy an approximate SL(2,Z) symmetry as a function of flux per unit cell and dissipation. At special multicritical points, they also satisfy a set of reparametrization Ward identities and have homogeneous, piecewise-linear correlation functions in momentum space. In this paper, we use these symmetries to find exact solutions for some of the correlation functions. We also comment on the form of the correlation functions in general, and verify that the SL(2,Z) duality transformation between different critical points is satisfied exactly in all cases where the full solution is known.
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.
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...
Classification of the phases of 1D spin chains with commuting Hamiltonians
International Nuclear Information System (INIS)
We consider the class of spin Hamiltonians on a 1D chain with periodic boundary conditions that are (i) translational invariant, (ii) commuting and (iii) scale invariant, where by the latter we mean that the ground state degeneracy is independent of the system size. We correspond a directed graph to a Hamiltonian of this form and show that the structure of its ground space can be read from the cycles of the graph. We show that the ground state degeneracy is the only parameter that distinguishes the phases of these Hamiltonians. Our main tool in this paper is the idea of Bravyi and Vyalyi (2005 Quantum Inform. Comput. 5 187–215) in using the representation theory of finite-dimensional C*-algebras to study commuting Hamiltonians. (paper)
Efficient transparent thin dye solar cells based on highly porous 1D photonic crystals
Energy Technology Data Exchange (ETDEWEB)
Colodrero, Silvia; Lopez-Lopez, Carmen; Miguez, Hernan [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Centro de Investigaciones Cientificas Isla de la Cartuja, C/Americo Vespucio 49, 41092 Sevilla (Spain); Forneli, Amparo; Pelleja, Laia [Institute of Chemical Research of Catalonia (ICIQ) Avda., Paisos Catalans 16, 43007 Tarragona (Spain); Palomares, Emilio [Institute of Chemical Research of Catalonia (ICIQ) Avda., Paisos Catalans 16, 43007 Tarragona (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA), Avda. Lluis Companys 23, 08010 Barcelona (Spain)
2012-03-21
A working electrode design based on a highly porous 1D photonic crystal structure that opens the path towards high photocurrents in thin, transparent, dye-sensitized solar cells is presented. By enlarging the average pore size with respect to previous photonic crystal designs, the new working electrode not only increases the device photocurrent, as predicted by theoretical models, but also allows the observation of an unprecedented boost of the cell photovoltage, which can be attributed to structural modifications caused during the integration of the photonic crystal. These synergic effects yield conversion efficiencies of around 3.5% by using just 2 {mu}m thick electrodes, with enhancements between 100% and 150% with respect to reference cells of the same thickness. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
A 1-D evolutionary model for icy satellites, applied to Enceladus
Prialnik, Uri Malamud Dina
2015-01-01
We develop a long-term 1-D evolution model for icy satellites that couples multiple processes: water migration and differentiation, geochemical reactions and silicate phase transitions, compaction by self-gravity, and ablation. The model further considers the following energy sources and sinks: tidal heating, radiogenic heating, geochemical energy released by serpentinization or absorbed by mineral dehydration, gravitational energy and insolation, and heat transport by conduction, convection, and advection. We apply the model to Enceladus, by guessing the initial conditions that would render a structure compatible with present-day observations, assuming the initial structure to have been homogeneous. Assuming the satellite has been losing water continually along its evolution, we postulate that it was formed as a more massive, more icy and more porous satellite, and gradually transformed into its present day state due to sustained long-term tidal heating. We consider several initial compositions and evolution...
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.
Quark-hadron duality in spin structure functions g1p and g1d
International Nuclear Information System (INIS)
New measurements of the spin structure functions of the proton and deuteron g1p(x,Q2) and g1d(x,Q2) in the nucleon resonance region are compared with extrapolations of target-mass-corrected next-to-leading-order (NLO) QCD fits to higher energy data. Averaged over the entire resonance region (W2 dependence for Q2>1.7 GeV2/c2. This ''global'' duality appears to result from cancellations among the prominent ''local'' resonance regions: in particular strong ?3/2 contributions in the ?(1232) region appear to be compensated by strong ?1/2 contributions in the resonance region centered on 1.5 GeV. These results are encouraging for the extension of NLO QCD fits to lower W and Q2 than have been used previously
Stochastic and Deterministic Vector Chromatography of Suspended Particles in 1D-Periodic Potentials
Bernate, Jorge A
2011-01-01
We present a comprehensive description of vector chromatography that includes deterministic and stochastic transport in 1D-periodic free-energy landscapes, with both energetic and entropic contributions, and highlights the parameters governing the deflection angle, i.e. the Peclet number and the partition ratio. We also investigate the dependence of the deflection angle on the shape of the free-energy landscape by varying the width of the linear transitions in an otherwise dichotomous potential. Finally, we present experimental results obtained in a microfluidic system in which gravity drives the suspended particles and, in combination with a bottom surface patterned with shallow rectangular grooves, creates a periodic landscape of (potential) energy barriers. The experiments validate the model and demonstrate that a simple, passive microdevice can lead to vector separation of colloidal particles based on both size and density.
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.
Ceschin, Johanna; Saint-Marc, Christelle; Laporte, Jean; Labriet, Adrien; Philippe, Chloé; Moenner, Michel; Daignan-Fornier, Bertrand; Pinson, Benoît
2014-06-13
5-Aminoimidazole-4-carboxamide-1-?-d-ribofuranoside (AICAr) is the precursor of the active monophosphate form (AICAR), a small molecule with potent anti-proliferative and low energy mimetic properties. The molecular bases for AICAR toxicity at the cellular level are poorly understood. Here, we report the isolation and characterization of several yeast AICAr-hypersensitive mutants. Identification of the cognate genes allowed us to establish that thiamine transporters Thi7 and Thi72 can efficiently take up AICAr under conditions where they are overexpressed. We establish that, under standard growth conditions, Nrt1, the nicotinamide riboside carrier, is the major AICAr transporter in yeast. A study of AICAR accumulation in human cells revealed substantial disparities among cell lines and confirmed that AICAr enters cells via purine nucleoside transporters. Together, our results point to significant differences between yeast and human cells for both AICAr uptake and AICAR accumulation. PMID:24778186
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
Analytical solutions for some defect problems in 1D hexagonal and 2D octagonal quasicrystals
Indian Academy of Sciences (India)
X Wang; E Pan
2008-05-01
We study some typical defect problems in one-dimensional (1D) hexagonal and two-dimensional (2D) octagonal quasicrystals. The first part of this investigation addresses in detail a uniformly moving screw dislocation in a 1D hexagonal piezoelectric quasicrystal with point group $6mm$. A general solution is derived in terms of two functions $\\varphi_{1}$, $\\varphi_{2}$, which satisfy wave equations, and another harmonic function $\\varphi_{3}$. Elementary expressions for the phonon and phason displacements, strains, stresses, electric potential, electric fields and electric displacements induced by the moving screw dislocation are then arrived at by employing the obtained general solution. The derived solution is verified by comparison with existing solutions. Also obtained in this part of the investigation is the total energy of the moving screw dislocation. The second part of this investigation is devoted to the study of the interaction of a straight dislocation with a semi-infinite crack in an octagonal quasicrystal. Here the crack penetrates through the solid along the period direction and the dislocation line is parallel to the period direction. We first derive a general solution in terms of four analytic functions for plane strain problem in octagonal quasicrystals by means of differential operator theory and the complex variable method. All the phonon and phason displacements and stresses can be expressed in terms of the four analytic functions. Then we derive the exact solution for a straight dislocation near a semi-infinite crack in an octagonal quasicrystal, and also present the phonon and phason stress intensity factors induced by the straight dislocation and remote loads.
A 1-D evolutionary model for icy satellites, applied to Enceladus
Prialnik, Dina; Malamud, Uri
2015-11-01
A 1-D long-term evolution code for icy satellites is presented, which couples multiple processes: water migration, geochemical reactions, water and silicate phase transitions, crystallization, compaction by self-gravity, and ablation. The code takes into account various energy sources: tidal heating, radiogenic heating, geochemical energy released by serpentinization or absorbed by mineral dehydration, gravitational energy, and insolation. It includes heat transport by conduction, convection, and advection.The code is applied to Enceladus, by guessing the initial conditions that would render a structure compatible with present-day observations, and adopting a homogeneous initial structure. Assuming that the satellite has been losing water continually along its evolution, it follows that it was formed as a more massive, more ice-rich and more porous object, and gradually transformed into its present day state, due to sustained tidal heating. Several initial compositions and evolution scenarios are considered, and the evolution is simulated for the age of the Solar System. The results corresponding to the present configuration are confronted with the available observational constraints. The present configuration is shown to be differentiated into a pure icy mantle, several tens of km thick, overlying a rocky core, composed of dehydrated rock in the central part and hydrated rock in the outer part. Such a differentiated structure is obtained not only for Enceladus, but for other medium size ice-rich bodies as well.Predictions for Enceladus are a higher rock/ice mass ratio than previously assumed, and a thinner ice mantle, compatible with recent estimates based on gravity field measurements. Although, obviously, the 1-D model cannot be used to explain local phenomena, it sheds light on the internal structure invoked in explanations of localized features and activities.
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.
Optimal modeling of 1D azimuth correlations in the context of Bayesian inference
De Kock, Michiel B.; Eggers, Hans C.; Trainor, Thomas A.
2015-09-01
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 two-dimensional (2D) angular correlations onto a 1D azimuth from three centrality classes of 200-GeV Au-Au collisions. We consider several data models typical of current model choices, including Fourier series (FS) and a Gaussian plus various combinations of individual cosine components. We evaluate model performance with BI methods and with power-spectrum analysis. We find that FS-only models are rejected in all cases by Bayesian analysis, which always prefers a Gaussian. A cylindrical quadrupole cos(2 ? ) is required in some cases but rejected for 0%-5%-central Au-Au collisions. Given a Gaussian centered at the azimuth origin, "higher harmonics" cos(m ? ) for m >2 are rejected. A model consisting of Gaussian +dipole cos(? )+quadrupole cos(2 ? ) provides good 1D data descriptions in all cases.
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)
International Nuclear Information System (INIS)
The principle of the direct conversion of thermal energy supplied by a heat source (burner) into electrical energy by means of thermocouples is outlined. Semiconductor thermocouples can be used to manufacture burner-generated thermoelectric generators with a total yield of about 3% and nominal power ranging from a few watts to several hundred watts. Owing to the transistorization of electrical equipment they offer autonomous energy sources of great reliability, able to run without supervision or maintenance for 10 to 12 months. Generators of this type developed in France by Thompson/CSF are described. They are used to supply Hertzian beam relay stations or television rediffusion
Experimental and computational study of the gas-phase reaction of O(1D) Atoms with VF5.
Rakhymzhan, Asylkhan A; Chichinin, Alexey I; Kiselev, Vitaly G; Gritsan, Nina P
2013-02-01
The reactions of O((1)D) atoms with VF(5) at room temperature have been studied by time-resolved laser magnetic resonance at the buffer gas (SF(6)) pressure of 6 Torr. The O((1)D) atoms were produced by the photodissociation of ozone using an excimer laser (KrF, 248 nm). By monitoring the kinetics of FO radical formation, the bimolecular rate constant of O((1)D) consumption in collisions with VF(5) has been determined to be k(VF(5)) = (7.5 ± 2.2) × 10(-11) cm(3) s(-1). The branching ratio for the channel producing FO radicals (k(8a)) has been found to be k(8a)/k(VF(5)) = 0.11 ± 0.02. Quantum chemical calculations at the CCSD(T)/CBS level of theory give evidence that the reactions of O((1)D) with VF(5) proceed via the VF(4)OF intermediate. The enthalpy of the reaction leading to this intermediate formation was calculated to be -245.8 kJ/mol. In qualitative agreement with the experimental results, the reaction channel O((1)D) + VF(5) ? FO + VF(4) (8a) turned out to be 72.9 kJ/mol energetically more favorable than the channel O((1)D) + VF(5) ? F + OVF(4) (8b). The dissociation enthalpy of the OVF(4) radical was calculated to be very low (18.1 kJ/mol); hence, the decay of OVF(4) to F + OVF(3) should proceed very fast. The molecular channel O((1)D) + VF(5) ? F(2) + VF(3)O, though being most favorable thermodynamically, is kinetically unimportant. PMID:23317310
International Nuclear Information System (INIS)
The generation of gases in wastes is a widespread and well-known phenomenon for conventional, as well as radioactive, wastes. At conventional landfills, the gases, if formed in sufficient amounts, may even be collected and used as an energy source. Gas generation in radioactive wastes under final disposal conditions is unavoidable and stems from the nature of certain major components of the wastes. Since the amount and types of gases have been identified as potential safety concerns for a repository in deep geologic formations (e.g. explosive and toxicity hazards and interactions with movement of groundwater), major efforts have been made to characterise the gas generating processes and their generation potential. The state of the art reached has been compiled in a recent status report. This paper summarises the results. Therefore, evaluated literature sources are not repeated here, but are extensively documented in the status report. (author)
Watson, Noshua
2002-01-01
Young adults in Generation X are facing financial problems. Because of their college and credit card debt, many in worse financial shape than anyone since the Depression and have little or no retirement savings. (JOW)
International Nuclear Information System (INIS)
A plasma generator comprises a metallic tube of small diameter inside which can circulate a gas such as argon at a small flow rate, which is discharged at the front end of the tube. The tube is coupled with an energizing structure which can comprise a frequency generator supplying electromagnetic microwaves, via a coaxial connection, a coupling structure allowing the transfer of the energy of the generator to the front portion of the metallic tube. In the absence of a gas current in the tube, the front portion radiates the energy transmitted to it in the manner of an antenna. When a gas is discharged at the end of the tube, said energy allows maintaining a plasma in front of the latter. This plasma generator device is usable in many applications, such as a blowtorch a light source or torch usable in spectrography, a plasma motor or an ion source
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.
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.
The Role of the Impedivity in the Magnetotelluric Response of 1D and 2D Structures
Esposito, Roberta; Giulia Di Giuseppe, Maria; Troiano, Antonio; Patella, Domenico; Mariano Castelo Branco, Raimundo
2014-05-01
The influence of the resistivity dispersion on the magnetotelluric (MT) response is analyzed. MT uses the natural electromagnetic (EM) field to determine the electrical resistivity of the subsoil and retrieve the geometry of lithospheric structures, revealing the presence of bodies as metallic deposits, hydrocarbons reservoirs, geothermal fluids. The frequency range of the EM field used varies from 10-4 to 104 Hz. If the soil is polarizable, the dispersion of the resistivity, whose characteristic frequency interval is between 10-2 and 102 Hz, may affect MT responses. Resistivity dispersion is a known phenomenology, which constitutes the basis of the Induced Polarization (IP) prospecting method. In the frequency domain (FD), the dispersion consists in a variation of the resistivity parameter as the frequency of the exciting current is changed. The dispersive resistivity, called impedivity, is a complex function of the frequency. At vanishing frequency, however, the impedivity is real and coincides with the classical resistivity parameter used in DC geoelectrical methods. A real asymptote is also approached as the frequency tends to infinity. The complex physical and chemical fluid-metal-rock interactions may produce induced polarization effects, which are related to the dispersion in rocks. This is manifested on the MT response, creating a distortion on the experimental curves. Disregarding the distortion effect may lead to misleading interpretation of the surveyed structures. We show the results from simulation of the MT responses, when dispersion is assumed to characterize the electrical properties of a region of the explored half-space. Initially, a 1D-layered earth is considered, with intermediate layer assumed to be dispersive. The influence of the dispersion amplitude on the shape of the MT responses is evaluated. The dispersion alters the shape of the curves in a way that, without any external constraints, may make the interpretation of the curves quite ambiguous. Successively, a 2D case is considered, consisting in a magma chamber at a depth of 1 km, buried into a soil. The synthetic responses were performed considering both the non-dispersive and the dispersive case and the differences of the modelled MT curves are compared. As for the 1D case, the dispersion alters the resistivity values, particularly at the boundary of the buried body, leading to an ambiguous interpretation. MT data alone are not sufficient to distinguish polarization effects or can induce to see dispersion where is not present. An approach to solve this problem consists of the combined interpretation of DC geoelectrical and MT data collected at the same site. Review of real cases is also shown.
Classical 1D maps, quantum graphs and ensembles of unitary matrices
Pakonski, Prot; Zyczkowski, Karol; Kus, Marek
2000-01-01
We study a certain class of classical one dimensional piecewise linear maps. For these systems we introduce an infinite family of Markov partitions into equal cells. The symbolic dynamics generated by these systems is described by bistochastic (doubly stochastic) matrices. We analyze the structure of graphs generated from the corresponding symbolic dynamics. We demonstrate that the spectra of quantized graphs corresponding to the regular classical systems have locally Poisso...
DEFF Research Database (Denmark)
Pehmøller, Christian; Treebak, Jonas Thue; Birk, Jesper Bratz; Chen, Shuai; Mackintosh, Carol; Hardie, D. Grahame; Richter, Erik; Wojtaszewski, Jørgen
2009-01-01
TBC1D1 is a Rab-GTPase-activating protein (GAP) known to be phosphorylated in response to insulin, growth factors, pharmacological agonists that activate 5'-AMP-activated protein kinase (AMPK), and muscle contraction. Silencing TBC1D1 in L6 muscle cells by siRNA increases insulin-stimulated GLUT4 translocation, and overexpression of TBC1D1 in 3T3-L1 adipocytes with low endogenous TBC1D1 expression inhibits insulin-stimulated GLUT4 translocation, suggesting a role of TBC1D1 in regulating GLUT4 tr...
Modification of 1D Ballistic Transport using an Atomic Force Microscope
Crook, R; Simmons, M Y; Ritchie, D A
1999-01-01
We have used the scanning charged tip of an Atomic Force Microscope (AFM) to produce images of the conductance variation of a quantised 1D ballistic channel. The channel was formed using electron beam defined 700 nm wide split gate surface electrodes over a high mobility GaAs/AlGaAs heterostructure with a two dimensional electron gas (2DEG) 98 nm beneath the surface. We operate the AFM at 1.5 K and 4.2 K in magnetic fields up to 2 T to observe several phenomena. With a dc voltage on the AFM tip we have produced conduction images of the tip potential perturbation, as the channel is a sensitive probe of the electrostatic potential. We have also performed gate sweeps with the tip at a series of points across the width of the channel. The observed structure in transconductance corresponds to the theoretical electron density for the first three sub-bands. When certain gates were biased near pinch off, stable two level switching was observed in the images. We were able to control the state of the switch with the ga...
Results and limits in the 1-D analytical modeling for the asymmetric DG SOI MOSFET
Directory of Open Access Journals (Sweden)
O. Cobianu
2008-05-01
Full Text Available This paper presents the results and the limits of 1-D analytical modeling of electrostatic potential in the low-doped p type silicon body of the asymmetric n-channel DG SOI MOSFET, where the contribution to the asymmetry comes only from p- and n-type doping of polysilicon used as the gate electrodes. Solving Poisson's equation with boundary conditions based on the continuity of normal electrical displacement at interfaces and the presence of a minimum electrostatic potential by using the Matlab code we have obtained a minimum potential with a slow variation in the central zone of silicon with the value pinned around 0.46 V, where the applied V_{GS} voltage varies from 0.45 V to 0.95 V. The paper states clearly the validity domain of the analytical solution and the important effect of the localization of the minimum electrostatic potential value on the potential variation at interfaces as a function of the applied V_{GS} voltage.
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)
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.
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...
On the Accuracy of the Non-Classical Transport Equation in 1-D Random Periodic Media
Vasques, Richard
2014-01-01
We present a first numerical investigation of the accuracy of the recently proposed {\\em non-classical transport equation}. This equation contains an extra independent variable (the path-length $s$), and models particle transport taking place in random media in which a particle's distance-to-collision is {\\em not} exponentially distributed. To solve the non-classical equation, one needs to know the $s$-dependent ensemble-averaged total cross section $\\Sigma_t(s)$, or its corresponding path-length distribution function $p(s)$. We consider a 1-D spatially periodic system consisting of alternating solid and void layers, randomly placed in the infinite line. In this preliminary work, we assume transport in rod geometry: particles can move only in the directions $\\mu=\\pm 1$. We obtain an analytical expression for $p(s)$, and use this result to compute the corresponding $\\Sigma_t(s)$. Then, we proceed to solve the non-classical equation for different test problems. To assess the accuracy of these solutions, we prod...
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
Batch Conversion of 1-D FITS Spectra to Common Graphical Display Files
MacConnell, Darrell J.; Patterson, A. P.; Wing, R. F.; Costa, E.; Jedrzejewski, R. I.
2008-09-01
Authors DJM, RFW, and EC have accumulated about 1000 spectra of cool stars from CTIO, ESO, and LCO over the interval 1985 to 1994 and processed them with the standard IRAF tasks into FITS files of normalized intensity vs. wavelength. With the growth of the Web as a means of exchanging and preserving scientific information, we desired to put the spectra into a Web-readable format. We have searched without success sites such as the Goddard FITS Image Viewer page, http://fits.gsfc.nasa.gov/fits_viewer.html, for a program to convert a large number of 1-d stellar spectra from FITS format into common formats such as PDF, PS, or PNG. Author APP has written a Python script to do this using the PyFITS module and plotting routines from Pylab. The program determines the wavelength calibration using header keywords and creates PNG plots with a legend read from a CSV file that may contain the star name, position, spectral type, etc. It could readily be adapted to perform almost any kind of simple batch processing of astronomical data. The program may be obtained from the first author (jack@stsci.edu). Support for DJM from the research program for CSC astronomers at STScI is gratefully acknowledged. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy Inc. under NASA contract NAS 5-26555.
1-D transport modelling of ZT-40M: Report on activity at LANL in Summer 1988
International Nuclear Information System (INIS)
The object of this work was to obtain transport coefficients that could match experimental behavior of I/sub z/, T/sub e/, n/sub e/ and n/sub i/, while ensuring that F and ? are in general agreement with experiment. It is stressed that the resulting transport coefficients have no predictive value. The code used is a 1-D transport code which contains a dynamo model that conserves helicity. Ion heating is introduced using various models. In this exercise only 1 data set is matched. The results show that anomalous ohmic heating of 25% to 33% Spitzer resistivity is sufficient to hold T/sub i/ ? T/sub e/. For all cases it was found that ? was approximately 1.46 while F was about -0.07. Both time dependent and radial profiles are studied. Reversal is enforced through a boundary condition on Bz at the wall. The field diffusion times are slow compared to transport times. The magnitude of F and ? decrease marginally implying that the dynamo model is creating toroidal flux. 11 figs
Simulating Helium abundances in the Martian upper atmosphere using 1-D and 3-D models
Bell, Jared M.; Bougher, S. W.; Mahaffy, Paul; Elrod, Meredith
2015-11-01
Chemically inert species, such as Helium, serve as an excellent tracer for the interplay between turbulent eddy diffusive processes and molecular diffusive processes. Using species such as Helium, we can effectively constrain the altitude of the homopause—or the transition from the well-mixed lower atmosphere to the mass-separation characteristic of the upper atmosphere. In this study, we will use the Mars Global Ionosphere-Thermosphere Model (M-GITM) to examine the impacts of altering the turbulent diffusion coefficient (eddy diffusion coefficient) on the simulated abundances of Helium. Using data obtained by the Neutral Gas and Ion Mass Spectrometer (NGIMS) onboard the Mars Atmosphere and Volatile Evolution (MAVEN) mission as a benchmark, we can examine what possible values for eddy diffusion in the thermosphere are most likely present in Mars’s upper atmosphere—in other words, we can assess where the mean homopause altitude is most likely located during the MAVEN mission. Furthermore, we will compare and contrast the results obtained when using a strictly classical, 1-D treatment of the problem with a more complete coupled, global 3-D treatment of the Martian atmosphere.
The Hanle Effect in 1D, 2D and 3D
Sainz, R Manso
1999-01-01
This paper addresses the problem of scattering line polarization and the Hanle effect in one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) media for the case of a two-level model atom without lower-level polarization and assuming complete frequency redistribution. The theoretical framework chosen for its formulation is the QED theory of Landi Degl'Innocenti (1983), which specifies the excitation state of the atoms in terms of the irreducible tensor components of the atomic density matrix. The self-consistent values of these density-matrix elements is to be determined by solving jointly the kinetic and radiative transfer equations for the Stokes parameters. We show how to achieve this by generalizing to Non-LTE polarization transfer the Jacobi-based ALI method of Olson et al. (1986) and the iterative schemes based on Gauss-Seidel iteration of Trujillo Bueno and Fabiani Bendicho (1995). These methods essentially maintain the simplicity of the Lambda-iteration method, but their convergence ra...
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.
Start-up predictions using PC1D, a personal-computer-based neutronics code
Energy Technology Data Exchange (ETDEWEB)
Sarafian, P.G.; Alsop, B.H.
1990-01-01
The determination of accurately estimated critical rod positions (ECP) is required for safe start-ups after plant shutdowns. Typical procedures employ point-core reactivity balance models to do such estimates. The point-core models generally are accurate enough for quasi-equilibrium conditions. These conditions exist when a plant operates near steady-state power level and rod position for a prolonged period of time prior to shutdown. Shutdowns from nonsteady conditions, however, result in transients in the spatial distribution of fission products such as xenon and samarium. Severe xenon transients could cause point-core model ECPs to deviate appreciably from plant critical conditions. These reactivity deviations can reach a significant fraction of the plant operating license limits. A dimensional neutronics model can be used for ECP calculations in large reactor cores with better accuracy than point-core models. The PC1D axial neutronics code was developed for this application for both steady-state and transient xenon conditions. Pacific Gas and Electric (PG and E) has utilized this code for the last two cycles of operation of two reactors. This paper describes the code and PG and E's experience using it for ECPs.
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
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...
Start-up predictions using PC1D, a personal-computer-based neutronics code
International Nuclear Information System (INIS)
The determination of accurately estimated critical rod positions (ECP) is required for safe start-ups after plant shutdowns. Typical procedures employ point-core reactivity balance models to do such estimates. The point-core models generally are accurate enough for quasi-equilibrium conditions. These conditions exist when a plant operates near steady-state power level and rod position for a prolonged period of time prior to shutdown. Shutdowns from nonsteady conditions, however, result in transients in the spatial distribution of fission products such as xenon and samarium. Severe xenon transients could cause point-core model ECPs to deviate appreciably from plant critical conditions. These reactivity deviations can reach a significant fraction of the plant operating license limits. A dimensional neutronics model can be used for ECP calculations in large reactor cores with better accuracy than point-core models. The PC1D axial neutronics code was developed for this application for both steady-state and transient xenon conditions. Pacific Gas and Electric (PG and E) has utilized this code for the last two cycles of operation of two reactors. This paper describes the code and PG and E's experience using it for ECPs
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
A tiny gas-sensor system based on 1D photonic crystal
Bouzidi, A.; Bria, D.; Akjouj, A.; Pennec, Y.; Djafari-Rouhani, B.
2015-12-01
We present a gas monitoring system for detecting the gas concentration in ambient air. This sensor is based on a 1D photonic crystal formed by alternating layers of magnesium fluoride (MgF2) and silicon (Si) with an empty layer in the middle. The lamellar cavity (defect layer) will be filled with polluted air that has a refractive index close to that of pure air, varying between n 0??=??1.00 to n 0??=??1.01. The transmission spectrum of this sensor is calculated by the Green function approach. The numerical results show that the transmission peak, which appears in the gap, is caused by the infiltration of impure air into the empty middle layer. This transmission peak can be used for detection purposes in real-time environmental monitoring. The peak frequency is sensitive to the air-gas mixture, and a variation in the refractive index as small as ?n??=??10?5 can be detected. A sensitivity, ??/?n, of 700?nm per refractive index unit (RIU) is achieved with this sensor.
1-D-ice flow modelling at EPICA Dome C and Dome Fuji, East Antarctica
Directory of Open Access Journals (Sweden)
F. Parrenin
2007-06-01
Full Text Available One-dimensional (1-D ice flow models are used to construct the age scales at the Dome C and Dome Fuji drilling sites (East Antarctica. The poorly constrained glaciological parameters at each site are recovered by fitting independent age markers identified within each core. We reconstruct past accumulation rates, that are larger than those modelled using the classical vapour saturation pressure relationship during glacial periods by up to a factor 1.5. During the Early Holocene, changes in reconstructed accumulation are not linearly related to changes in ice isotopic composition. A simple model of past elevation changes is developed and shows an amplitude variation of 110–120 m at both sites. We suggest that there is basal melting at Dome C (0.56±0.19 mm/yr. The reconstructed velocity profile is highly non-linear at both sites, which suggests complex ice flow effects. This induces a non-linear thinning function in both drilling sites, which is also characterized by bumps corresponding to variations in ice thickness with time.
Specifications of ZnO growth for heterostructure solar cell and PC1D based simulations
Hussain, Babar; Ebong, Abasifreke
2015-01-01
This data article is related to our recently published article (Hussain et al., in press [1]) where we have proposed a new solar cell model based on n-ZnO as front layer and p-Si as rear region. The ZnO layer will act as an active n-layer as well as antireflection (AR) coating saving considerable processing cost. There are several reports presenting use of ZnO as window/antireflection coating in solar cells (Mansoor et al., 2015; Haq et al., 2014; Hussain et al., 2014; Matsui et al., 2014; Ding et al., 2014 [2], [3], [4], [5], [6]) but, here, we provide data specifically related to simultaneous use of ZnO as n-layer and AR coating. Apart from the information we already published, we provide additional data related to growth of ZnO (with and without Ga incorporation) layers using MOCVD. The data related to PC1D based simulation of internal and external quantum efficiencies with and without antireflection effects of ZnO as well as the effects of doping level in p-Si on current–voltage characteristics have been provided. PMID:26587557
Theoretical limits of the multistacked 1D and 2D microstructured inorganic solar cells
Yengel, Emre; Karaagac, Hakan; VJ, Logeeswaran; Islam, M. Saif
2015-09-01
Recent studies in monocrystalline semiconductor solar cells are focused on mechanically stacking multiple cells from different materials to increase the power conversion efficiency. Although, the results show promising increase in the device performance, the cost remains as the main drawback. In this study, we calculated the theoretical limits of multistacked 1D and 2D microstructered inorganic monocrstalline solar cells. This system is studied for Si and Ge material pair. The results show promising improvements in the surface reflection due to enhanced light trapping caused by photon-microstructures interactions. The theoretical results are also supported with surface reflection and angular dependent power conversion efficiency measurements of 2D axial microwall solar cells. We address the challenge of cost reduction by proposing to use our recently reported mass-manufacturable fracture-transfer- printing method which enables the use of a monocrystalline substrate wafer for repeated fabrication of devices by consuming only few microns of materials in each layer of devices. We calculated thickness dependent power conversion efficiencies of multistacked Si/Ge microstructured solar cells and found the power conversion efficiency to saturate at 26% with a combined device thickness of 30 ?m. Besides having benefits of fabricating low-cost, light weight, flexible, semi-transparent, and highly efficient devices, the proposed fabrication method is applicable for other III-V materials and compounds to further increase the power conversion efficiency above 35% range.
1D Tight-Binding Models Render Quantum First Passage Time "Speakable"
Ranjith, V.; Kumar, N.
2015-12-01
The calculation of First Passage Time (moreover, even its probability density in time) has so far been generally viewed as an ill-posed problem in the domain of quantum mechanics. The reasons can be summarily seen in the fact that the quantum probabilities in general do not satisfy the Kolmogorov sum rule: the probabilities for entering and non-entering of Feynman paths into a given region of space-time do not in general add up to unity, much owing to the interference of alternative paths. In the present work, it is pointed out that a special case exists (within quantum framework), in which, by design, there exists one and only one available path (i.e., door-way) to mediate the (first) passage -no alternative path to interfere with. Further, it is identified that a popular family of quantum systems - namely the 1d tight binding Hamiltonian systems - falls under this special category. For these model quantum systems, the first passage time distributions are obtained analytically by suitably applying a method originally devised for classical (stochastic) mechanics (by Schroedinger in 1915). This result is interesting especially given the fact that the tight binding models are extensively used in describing everyday phenomena in condense matter physics.
Growth of intermetallic compounds in the Au–In system: Experimental study and 1-D modelling
International Nuclear Information System (INIS)
The gold–indium system is of primary interest for bonding processes such as solid–liquid interdiffusion bonding. In order to optimize the manufacturing parameters, it is essential to know which intermetallic compounds (IMCs) are formed when solid Au and liquid In are brought into close contact with each other, and what are their growth kinetics. For this purpose, we fabricated diffusion couples above and below the melting point of In (for T=250 and 150 °C respectively). Three IMCs, identified as AuIn2, AuIn and Au7In3, are always observed in the reaction zone, even after short times. AuIn2 is the thickest and fastest growing layer and AuIn is only present as a thin layer. Whereas AuIn2 and AuIn exhibit an equiaxed structure, Au7In3 is found to grow as columnar grains. The diffusion coefficients in each phase were determined by means of a 1-D finite difference modelling of In diffusion. The values are consistent and can be used to predict the growth rate as a function of temperature and time, i.e. to simulate a whole bonding process with finite thicknesses
Efficient 3D/1D self-consistent integral-equation analysis of ICRH antennae
International Nuclear Information System (INIS)
This work presents a comprehensive account of the theory and implementation of a method for the self-consistent numerical analysis of plasma-facing ion-cyclotron resonance heating (ICRH) antenna arrays. The method is based on the integral-equation formulation of the boundary-value problem, solved via a weighted-residual scheme. The antenna geometry (including Faraday shield bars and a recess box) is fairly general and three-dimensional (3D), and the plasma is in the one-dimensional (1D) 'slab' approximation; finite-Larmor radius effects, as well as plasma density and temperature gradients, are considered. Feeding via the voltages in the access coaxial lines is self consistently accounted throughout and the impedance or scattering matrix of the antenna array obtained therefrom. The problem is formulated in both the dual space (physical) and spectral (wavenumber) domains, which allows the extraction and simple handling of the terms that slow the convergence in the spectral domain usually employed. This paper includes validation tests of the developed code against measured data, both in vacuo and in the presence of plasma. An example of application to a complex geometry is also given. (author)
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
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.
Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D
Directory of Open Access Journals (Sweden)
B. Leterme
2012-08-01
Full Text Available The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future 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 estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from ?42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain, considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from ?69% to ?14% compared to the present-day climate.
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.
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.
Rational design of D-A1-D-A2 conjugated polymers with superior spectral coverage.
Hedström, Svante; Tao, Qiang; Wang, Ergang; Persson, Petter
2015-10-28
The spectral coverage of a light-harvesting polymer largely determines the maximum achievable photocurrent in organic photovoltaics, and therefore constitutes a crucial parameter for improving their performance. The D-A1-D-A2 copolymer motif is a new and promising design strategy for extending the absorption range by incorporating two acceptor units with complementary photoresponses. The fundamental factors that promote an extended absorption are here determined for three prototype D-A1-D-A2 systems through a combination of experimental and computational methods. Systematic quantum chemical calculations are then used to reveal the intrinsic optical properties of ten further D-A1-D-A2 polymer candidates. These investigated polymers are all predicted to exhibit intense primary absorption peaks at 615-954 nm, corresponding to charge-transfer (CT) transitions to the stronger acceptor, as well as secondary absorption features at 444-647 nm that originate from CT transitions to the weaker acceptors. Realization of D-A1-D-A2 polymers with superior spectral coverage is thereby found to depend critically on the spatial and energetic separation between the two distinct acceptor LUMOs. Two promising D-A1-D-A2 copolymer candidates were finally selected for further theoretical and experimental study, and demonstrate superior light-harvesting properties in terms of significantly extended spectral coverage. This demonstrates great potential for enhanced light-harvesting in D-A1-D-A2 polymers via multiple absorption features compared to traditional D-A polymers. PMID:26394002
Multiple tissue-specific isoforms of sulfatide activate CD1d-restricted type II NKT cells
DEFF Research Database (Denmark)
Blomqvist, Maria; Rhost, Sara; Teneberg, Susann; Löfbom, Linda; Østerbye, Thomas; Brigl, Manfred; Månsson, Jan-Eric; Cardell, Susanna L
2009-01-01
The glycosphingolipid sulfatide (SO(3)-3Galbeta1Cer) is a demonstrated ligand for a subset of CD1d-restricted NKT cells, which could regulate experimental autoimmune encephalomyelitis, a murine model for multiple sclerosis, as well as tumor immunity and experimental hepatitis. Native sulfatide is a mixture of sulfatide isoforms, i.e. sulfatide molecules with different long-chain bases and fatty acid chain lengths and saturation. Here, we demonstrate that sulfatide-specific CD1d-restricted murine...
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.
Feng, Yuquan; Li, Min; Fan, Huitao; Huang, Qunzeng; Qiu, Dongfang; Shi, Hengzhen
2015-01-21
A novel open-framework copper borophosphate, Na5KCu3[B9P6O33(OH)3]·H2O (), has been synthesised by a boric acid flux method. Its structure can be viewed as a 3-D open framework constructed by the connection of Cu(II)O6 octahedra and 1-D (4,4)-connected borophosphate anionic structures composed of trigonal-planar BO2(OH) groups, tetrahedral BO4 and PO4 groups. The compound not only features a novel borophosphate anionic partial structure containing 1-D 12-MR channels, but also exhibits ferromagnetic interactions and high catalytic activity for the oxidative degradation of chitosan. PMID:25437261
International Nuclear Information System (INIS)
The object of the invention is to reduce the risks of solids in the steam generator being deposited where they might lead to corrosion. Diagrams and full details are given. A steam generator is described for use in generating steam by indirect heat exchange between a primary fluid and water, the generator comprising a bundle of U-tubes extending between primary fluid inlet and outlet headers and located within a shell or casing, wherein a perforated blow-down tube is provided adjacent to the top of at least the primary fluid outlet header, preferably each header. Through the blow-down tube a continuous purge of water can be removed to create fluid flow over the top surface of the headers and so flush deposited solids to the blow-down tubes where they will be ejected. The blow-down tubes can also provide an intermittent wash for the top surfaces of the headers. Various other aspects of the invention further prevent or reduce the dangerous deposition of solids. (UK)
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.
Directory of Open Access Journals (Sweden)
Janda Jan-Oliver
2012-04-01
Full Text Available Abstract Background One aim of the in silico characterization of proteins is to identify all residue-positions, which are crucial for function or structure. Several sequence-based algorithms exist, which predict functionally important sites. However, with respect to sequence information, many functionally and structurally important sites are hard to distinguish and consequently a large number of incorrectly predicted functional sites have to be expected. This is why we were interested to design a new classifier that differentiates between functionally and structurally important sites and to assess its performance on representative datasets. Results We have implemented CLIPS-1D, which predicts a role in catalysis, ligand-binding, or protein structure for residue-positions in a mutually exclusive manner. By analyzing a multiple sequence alignment, the algorithm scores conservation as well as abundance of residues at individual sites and their local neighborhood and categorizes by means of a multiclass support vector machine. A cross-validation confirmed that residue-positions involved in catalysis were identified with state-of-the-art quality; the mean MCC-value was 0.34. For structurally important sites, prediction quality was considerably higher (mean MCC = 0.67. For ligand-binding sites, prediction quality was lower (mean MCC = 0.12, because binding sites and structurally important residue-positions share conservation and abundance values, which makes their separation difficult. We show that classification success varies for residues in a class-specific manner. This is why our algorithm computes residue-specific p-values, which allow for the statistical assessment of each individual prediction. CLIPS-1D is available as a Web service at http://www-bioinf.uni-regensburg.de/. Conclusions CLIPS-1D is a classifier, whose prediction quality has been determined separately for catalytic sites, ligand-binding sites, and structurally important sites. It generates hypotheses about residue-positions important for a set of homologous proteins and focuses on conservation and abundance signals. Thus, the algorithm can be applied in cases where function cannot be transferred from well-characterized proteins by means of sequence comparison.
Duality in 2 + 1D quantum elasticity: superconductivity and quantum nematic order
International Nuclear Information System (INIS)
Superfluidity and superconductivity are traditionally understood in terms of an adiabatic continuation from the Bose-gas limit. Here we demonstrate that at least in a 2 + 1D Bose system, superfluidity can arise in a strict quantum field-theoretic setting. Taking the theory of quantum elasticity (describing phonons) as a literal quantum field theory with a bosonic statistic, superfluidity and superconductivity (in the EM charged case) emerge automatically when the shear rigidity of the elastic state is destroyed by the proliferation of topological defects (quantum dislocations). Off-diagonal long range order in terms of the field operators of the constituent particles is not required. This is one of the outcomes of the broader pursuit presented in this paper. In essence, it amounts to the generalization of the well known theory of crystal melting in two dimensions by Nelson et al. [Phys. Rev. B 19 (1979) 2457; Phys. Rev. B 19 (1979) 1855], to the dynamical theory of bosonic states exhibiting quantum liquid-crystalline orders in 2 + 1 dimensions. We strongly rest on the field-theoretic formalism developed by Kleinert [Gauge fields in Condensed Matter, vol. II: Stresses and Defects, Differential Geometry, Crystal Defects, World Scientific, Singapore, 1989] for classical melting in 3D. Within this framework, the disordered states correspond to Bose condensates of the topological excitations, coupled to gauge fields describing the capacity of the elastic medium to propagate stresses. Our focus is primarily on the nematic states, corresponding with condensates of dislocations, under the topological condition that disclinations remain massive. The dislocations carry Burgers vectors as topological charges. Conventional nematic order, i.e., the breaking of space-rotations, corresponds in this field-theoretic duality framework with an ordering of the Burgers vectors. However, we also demonstrate that the Burgers vectors can quantum disorder despite the massive character of the disclinations. We identify the physical nature of the 'Coulomb nematic' suggested by Lammert et al. [Phys. Rev. Lett. 70 (1993) 1650; Phys. Rev. E 52 (1995) 1778] on gauge-theoretical grounds. The 2 + 1D quantum liquid crystals differ in fundamental regards from their 3D classical counterparts due to the presence of a dynamical constraint. This constraint is the glide principle, well known from metallurgy, which states that dislocations can only propagate in the direction of their Burgers vector. In the present framework this principle plays a central role. This constraint is necessary to decouple compression rigidity from the dislocation condensate. The shear rigidity is not protected, and as a result the shear modes acquire a Higgs mass in the dual condensate. This is the way the dictum that translational symmetry breaking goes hand in hand with shear rigidity emerges in the field theory. However, because of the glide principle compression stays massless, and the fluids are characterized by an isolated massless compression mode and are therefore superfluids. Glide also causes the shear Higgs mass to vanish at orientations perpendicular to the director in the ordered nematic, and the resulting state can be viewed as a quantum smectic of a novel kind. Our most spectacular result is a new hydrodynamical way of understanding the conventional electromagnetic Meissner state (superconducting state). Generalizing to the electromagnetically charged elastic medium ('Wigner Crystal') we find that the Higgs mass of the shear gauge fields, becoming finite in the nematic quantum fluids, automatically causes a Higgs mass in the electromagnetic sector by a novel mechanism
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.
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.
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.
Nonlinear analysis of flexural wave propagation through 1D waveguides with a breathing crack
Joglekar, D. M.; Mitra, M.
2015-05-01
An analytical-numerical approach is presented to investigate the flexural wave propagation through a slender semi-infinite beam with a breathing edge-crack. A Fourier transform based spectral finite element method is employed in an iterative manner to analyze the nonlinear response of the cracked beam subjected to a transverse tone burst excitation. Results obtained using the spectral finite element method are corroborated using 1D finite element analysis that involves the formulation and solution of a linear complementarity problem at every time step. In both the methods, an equivalent rotational spring is used to model the local flexibility caused by an open crack and the respective damaged beam element is formulated. The effect of crack-breathing is accounted for by an intermittent contact force acting at the nodes of the damaged beam element. A parallel study involving the open crack model is performed in the same setting to facilitate a comparison between the open and the breathing crack model. An illustrative case study reveals clearly the existence of higher order harmonics originating from the crack-breathing phenomenon which are absent if the crack is assumed to remain open throughout. A thorough investigation of the wrap-around effect associated with spectral finite element method reveals that the relative strengths of the higher order harmonics are not influenced by the wrap-around effect. A brief parametric study involving the variation of crack depth is presented at the end which suggests that the magnitudes of the higher harmonic peaks increase with increasing levels of crack severity. The present study can be potentially useful in the efforts geared toward the development of damage detection/localization strategies based on the nonlinear wave-damage interaction.
M-theory solutions invariant under D(2,1; ?) + D(2,1;?)
International Nuclear Information System (INIS)
We simplify and extend the construction of half-BPS solutions to 11-dimensional supergravity, with isometry superalgebra D(2,1;?) + D(2,1;?). Their space-time has the form AdS3 x S3 x S3 warped over a Riemann surface ?. It describes near-horizon geometries of M2 branes ending on, or intersecting with, M5 branes along a common string. The general solution to the BPS equations is specified by a reduced set of data (?, h, G), where ? is the real parameter of the isometry superalgebra, and h and G are functions on ? whose differential equations and regularity conditions depend only on the sign of ?. The magnitude of ? enters only through the map of h,G onto the supergravity fields, thereby promoting all solutions into families parametrized by vertical stroke ? vertical stroke. By analyzing the regularity conditions for the supergravity fields, we prove two general theorems: (i) that the only solution with a 2-dimensional CFT dual is AdS3 x S3 x S3 x R 2, modulo discrete identifications of the flat R 2, and (ii) that solutions with ? 4/Z2 or AdS7' regions; highly-curved M5-branes; and a coordinate singularity called the ''cap''. By putting these ''Lego'' pieces together we recover all known global regular solutions with the above symmetry, including the self-dual strings on M5 for ? 0, but now promoted to families parametrized by vertical stroke ? vertical stroke. We also construct exactly new regular solutions which are asymptotic to AdS4/Z2 for ? 0 solutions with highly curved M5-brane regions, which are the formal continuation of the self-dual string solutions across the decompactification point at ? = 0. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
MAGNETIC CORE SHELL STRUCTURES: from 0D to 1D assembling.
Ficai, Denisa; Ficai, Anton; Dinu, Elena; Oprea, Ovidiu; Sonmez, Maria; Keler, Memduh Kagan; Sahin, Yesim Muge; Ekren, Nazmi; Inan, Ahmet Talat; Daglilar, Sibel; Gunduz, Oguzhan
2015-01-01
Material research and development studies are focused on different techniques of bringing out nanomaterials with desired characteristics and properties. From the point of view of materials development, nowadays scientists are strongly focused on obtaining materials with predefined characteristics and properties. The morphology control seems to be a determinant factor and increasing attention is devoted to this aspect. At this moment it is possible to engineer the material's features by using different methods and materials combination for both medical and industrial applications. In the applications of chemistry and synthesis, biology, mechanics, optics solar cells and microelectronics tailoring the adjustable parameters of stoichiometry, chemical structure, shape and segregation are evaluated and opens new fields. Because of the magnetic features of nanoparticles and durable particle size, less than 100 nm, this study is aiming to describe their uses in practical applications. That's why the whole hydrodynamic magnetic core shell topic will be reviewed on this paper. Additionally, the properties acting in general sight in solid-state physics are utilized for material selection and for defining issue connecting the core, shell structure and their producing properties. Here, in the study of core/shell nanoparticle various physical and chemical synthesis routes and the effect of electrospun method are briefly discussed. Starting from a real void of the scientific literature, the existent data related to the 1D magnetic electrospun materials are reviewed. The perspectives in the medical, environmental or energetic sector is great and bring some real advantages related to the 0D core@shell structures because both mechanical and biological properties are dependent on the morphology of the materials. PMID:26377653
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
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...
International Nuclear Information System (INIS)
One-dimensional Sn-3.5Ag alloy nanosolders have been successfully fabricated by a dc electrodeposition technique into nanoporous templates, and their soldering quality has been demonstrated in nanoscale electrical welding for the first time, which indicates that they can easily form remarkably reliable conductive joints. The electrical measurement shows that individual 1D Sn-3.5Ag nanosolders have a resistivity of 28.9 ??·cm. The morphology, crystal structure and chemistry of these nanosolders have been characterized at the nanoscale. It is found that individual 1D Sn-3.5Ag alloy nanosolders have a continuous morphology and smooth surface. XPS confirms the presence of tin and silver with a mass ratio of 96.54:3.46, and EDX elemental mappings clearly reveal that the Sn and Ag elements have a uniform distribution. Coveragent beam electron diffractions verify that the crystal phases of individual 1D Sn-3.5Ag alloy nanosolders consist of matrix ?-Sn and the intermetallic compound Ag3Sn. The reflow experiments reveal that the eutectic composition of the 1D Sn-Ag alloy nanowire is shifted to the Sn rich corner. This work may contribute one of the most important tin-based alloy nanosolders for future nanoscale welding techniques, which are believed to have broad applications in nanotechnology and the future nano-industry. (paper)
On the regularity of the flow map associated with the 1D cubic periodic Half-Wave equation
Georgiev, V.(University of West Bohemia, Pilsen, Czech Republic); Tzvetkov, N; Visciglia, N.
2015-01-01
We prove that the solution map associated with the $1D$ half-wave cubic equation in the periodic setting cannot be uniformly continuous on bounded sets of the periodic Sobolev spaces $H^s$ with $s\\in (1/4, 1/2)$
Ok, Jong G.; Panday, Ashwin; Lee, Taehwa; Jay Guo, L.
2014-11-01
We present a versatile and simple methodology for continuous and scalable 2D micro/nano-structure fabrication via sequential 1D patterning strokes enabled by dynamic nano-inscribing (DNI) and vibrational indentation patterning (VIP) as well as a `single-stroke' 2D patterning using a DNI tool in VIP.
Directory of Open Access Journals (Sweden)
Zuzana Ho?ejší
2014-04-01
Full Text Available The R2TP cochaperone complex plays a critical role in the assembly of multisubunit machines, including small nucleolar ribonucleoproteins (snoRNPs, RNA polymerase II, and the mTORC1 and SMG1 kinase complexes, but the molecular basis of substrate recognition remains unclear. Here, we describe a phosphopeptide binding domain (PIH-N in the PIH1D1 subunit of the R2TP complex that preferentially binds to highly acidic phosphorylated proteins. A cocrystal structure of a PIH-N domain/TEL2 phosphopeptide complex reveals a highly specific phosphopeptide recognition mechanism in which Lys57 and 64 in PIH1D1, along with a conserved DpSDD phosphopeptide motif within TEL2, are essential and sufficient for binding. Proteomic analysis of PIH1D1 interactors identified R2TP complex substrates that are recruited by the PIH-N domain in a sequence-specific and phosphorylation-dependent manner suggestive of a common mechanism of substrate recognition. We propose that protein complexes assembled by the R2TP complex are defined by phosphorylation of a specific motif and recognition by the PIH1D1 subunit.
Rancan, Marzio; Armelao, Lidia
2015-08-21
DMSO promotes dimensional variability driving the formation of Cu-bpy architectures such as a 3D nanoporous network (1) and a 1D chiral polymer (2) self-assembled from achiral building blocks. The same solvent rules a reversible conversion between 1 and 2. PMID:26165598
Energy Technology Data Exchange (ETDEWEB)
Drury, J.; Di Costanzo, L; Penning, T; Christianson, D
2009-01-01
The {Delta}{sup 4}-3-ketosteroid functionality is present in nearly all steroid hormones apart from estrogens. The first step in functionalization of the A-ring is mediated in humans by steroid 5{alpha}- or 5{beta}-reductase. Finasteride is a mechanism-based inactivator of 5{alpha}-reductase type 2 with subnanomolar affinity and is widely used as a therapeutic for the treatment of benign prostatic hyperplasia. It is also used for androgen deprivation in hormone-dependent prostate carcinoma, and it has been examined as a chemopreventive agent in prostate cancer. The effect of finasteride on steroid 5{beta}-reductase (AKR1D1) has not been previously reported. We show that finasteride competitively inhibits AKR1D1 with low micromolar affinity but does not act as a mechanism-based inactivator. The structure of the AKR1D1 {center_dot} NADP{sup +} {center_dot} finasteride complex determined at 1.7 {angstrom} resolution shows that it is not possible for NADPH to reduce the {Delta}{sup 1-2}-ene of finasteride because the cofactor and steroid are not proximal to each other. The C3-ketone of finasteride accepts hydrogen bonds from the catalytic residues Tyr-58 and Glu-120 in the active site of AKR1D1, providing an explanation for the competitive inhibition observed. This is the first reported structure of finasteride bound to an enzyme involved in steroid hormone metabolism.
International Nuclear Information System (INIS)
The generator column is arranged in a hollow space in the centre with lead shielding. The column has an inlet opening for the inlet of eluant and an outlet opening for the eluate charged with Technetium 99, for example. To increase the degree of separation the column consists of at least two concentric sections of the column which fit into one another. The individual sections of the column are annular. (DG)
Srinivasan-Rao, Triveni (Shoreham, NY)
2002-01-01
A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.
International Nuclear Information System (INIS)
The patent is concerned with the even distribution of steam over the liquid separator in steam raising units with U-tubes standing on a tube plate. The efficiency or use of the separator is improved by the even distribution over the boiler cross-section. This is achieved by the installation of a guide surface between the space filled with U-tubes and the separator(s). This guide surface, consisting of a fixed part and a part which can be rotated about a horizontal axis, extends nearly over the whole width of the space filled with U-tubes. The guide surface, which is slightly inclined to the vertical, lies with its axis parallel to an imaginary separating surface between the cold and warm legs of the U-tubes, but displaced towards the hot side. In this way the larger quantity of steam generated on the hot side of the U-tubes and the smaller quantity of steam generated on the colder side of the U-tubes are evenly distributed to the separator surface. In consequence, apart from better use of the separator or apart from the possibility of going to smaller dimensions, the pressure loss before the separator is reduced by the guide surface, with better stability of steam generation. (TK)
DEFF Research Database (Denmark)
PehmØller, Christian; Treebak, Jonas Thue
2009-01-01
TBC1D1 is a Rab-GTPase-activating protein (GAP) known to be phosphorylated in response to insulin, growth factors, pharmacological agonists that activate 5'-AMP-activated protein kinase (AMPK), and muscle contraction. Silencing TBC1D1 in L6 muscle cells by siRNA increases insulin-stimulated GLUT4 translocation, and overexpression of TBC1D1 in 3T3-L1 adipocytes with low endogenous TBC1D1 expression inhibits insulin-stimulated GLUT4 translocation, suggesting a role of TBC1D1 in regulating GLUT4 translocation. Aiming to unravel the regulation of TBC1D1 during contraction and the potential role of AMPK in intact skeletal muscle, we used EDL muscles from wild-type (WT) and AMPK kinase dead (KD) mice. We explored the site-specific phosphorylation of TBC1D1 Ser(237) and Thr(596) and their relation to 14-3-3 binding, a proposed mechanism for regulation of GAP function of TBC1D1. We show that muscle contraction increases 14-3-3 binding to TBC1D1 as well as phosphorylation of Ser(237) and Thr(596) in an AMPK-dependent manner. AMPK activation by AICAR induced similar Ser(237) and Thr(596) phosphorylation of, and 14-3-3 binding to, TBC1D1 as muscle contraction. Insulin did not increase Ser(237) phosphorylation or 14-3-3 binding to TBC1D1. However, insulin increased Thr(596) phosphorylation, and intriguingly this response was fully abolished in the AMPK KD mice. Thus, TBC1D1 is differentially regulated in response to insulin and contraction. This study provides genetic evidence to support an important role for AMPK in regulating TBC1D1 in response to both of these physiological stimuli.
Subpoblaciones de linfocitos B y su expresión de CD1d en pacientes con lupus eritematoso sistémico
Directory of Open Access Journals (Sweden)
Claudia Carolina Sánchez Parra
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 reguladora (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.
Effects of GWAS-associated genetic variants on lncRNAs within IBD and T1D candidate loci
DEFF Research Database (Denmark)
Mirza, Aashiq H; Kaur, Simranjeet
2014-01-01
Long non-coding RNAs are a new class of non-coding RNAs that are at the crosshairs in many human diseases such as cancers, cardiovascular disorders, inflammatory and autoimmune disease like Inflammatory Bowel Disease (IBD) and Type 1 Diabetes (T1D). Nearly 90% of the phenotype-associated single-nucleotide polymorphisms (SNPs) identified by genome-wide association studies (GWAS) lie outside of the protein coding regions, and map to the non-coding intervals. However, the relationship between phenotype-associated loci and the non-coding regions including the long non-coding RNAs (lncRNAs) is poorly understood. Here, we systemically identified all annotated IBD and T1D loci-associated lncRNAs, and mapped nominally significant GWAS/ImmunoChip SNPs for IBD and T1D within these lncRNAs. Additionally, we identified tissue-specific cis-eQTLs, and strong linkage disequilibrium (LD) signals associated with these SNPs. We explored sequence and structure based attributes of these lncRNAs, and also predicted the structuraleffects of mapped SNPs within them. We also identified lncRNAs in IBD and T1D that are under recent positive selection. Our analysis identified putative lncRNA secondary structure-disruptive SNPs within and in close proximity (+/-5 kb flanking regions) of IBD and T1D loci-associated candidate genes, suggesting that these RNA conformation-altering polymorphisms might be associated with diseased-phenotype. Disruption of lncRNA secondary structure due to presence of GWAS SNPs provides valuable information that could be potentially useful for future structure-function studies on lncRNAs.
Implementation of a 1D k-? model for studying the vertical mixing in Comau fjord, Chile
Sepulveda, O.; De La Fuente, A.; Bouffard, D.; Meruane, C.
2014-12-01
Comau fjord,located in southern Chile (42º22' S, 72º25' W), is a narrow and deep semi-enclosed basin of 68 km-long, 4 km-width and a maximum depth of 500 m. The fjord has a semi-diurnal tidal regime dominated by the M2 component, with maximum oscillations that reach 7,5 m. The stratification and mixing in the Comau fjord was examined in a field campaign during January 2014, using temperature and conductivity sensors and a down-looking ADCP. A very shallow salinity-controlled stratification was detected with a very strong and sharp density change at about 8 m-depth. Furthermore, a surface current of magnitude 5 cm·s-1 due to river discharge was measured and found to interact with both the tide and the wind forcing. A description of the fjord's hydrodynamic was performed using a general 1D vertical k-? model, in which the stratification was forced by exchanges of energy and momentum with the atmosphere. In addition, the river currents and the effects of tidal influence were incorporated through adding terms in the momentum equation that account for non-linear interaction between current and tide, and a periodic barotropic pressure gradient due to the tide. A decomposition in vertical modes were carried out to analyze the velocity data and the results of the model, which showed that the energy is concentrated in the first barotropic mode, in agreement with the fact that the aspect ratio of stratification h1/(h1+h2) is close to 0. Field data and numerical simulations suggest that the energy injected to the system by external forcings is dissipated in the surface region as a consequence of the strong stratification, which acts as a buffer of the energy transfer, controlling the vertical mixing. The model implemented calculates the vertical dissipation rate of turbulent kinetic energy, allowing the estimation of turbulent diffusion parameter, thus connecting the system's hydrodynamics response with the vertical transport of water quality parameters of the system.
M-theory solutions invariant under D(2,1; ?) + D(2,1;?)
Energy Technology Data Exchange (ETDEWEB)
Bachas, C. [Laboratoire de Physique Theorique de l' Ecole Normale Superieure Unite mixte (UMR 8549) du CNRS et de l' ENS, Paris (France); D' Hoker, E. [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); Estes, J. [Blackett Laboratory, Imperial College, London (United Kingdom); Krym, D. [Physics Department, New York City College of Technology, The City University of New York, Brooklyn, NY (United States)
2014-03-06
We simplify and extend the construction of half-BPS solutions to 11-dimensional supergravity, with isometry superalgebra D(2,1;?) + D(2,1;?). Their space-time has the form AdS{sub 3} x S{sup 3} x S{sup 3} warped over a Riemann surface ?. It describes near-horizon geometries of M2 branes ending on, or intersecting with, M5 branes along a common string. The general solution to the BPS equations is specified by a reduced set of data (?, h, G), where ? is the real parameter of the isometry superalgebra, and h and G are functions on ? whose differential equations and regularity conditions depend only on the sign of ?. The magnitude of ? enters only through the map of h,G onto the supergravity fields, thereby promoting all solutions into families parametrized by vertical stroke ? vertical stroke. By analyzing the regularity conditions for the supergravity fields, we prove two general theorems: (i) that the only solution with a 2-dimensional CFT dual is AdS{sub 3} x S{sup 3} x S{sup 3} x R {sup 2}, modulo discrete identifications of the flat R {sup 2}, and (ii) that solutions with ? < 0 cannot have more than one asymptotic higher-dimensional AdS region. We classify the allowed singularities of h and G near the boundary of ?, and identify four local solutions: asymptotic AdS{sub 4}/Z{sub 2} or AdS{sub 7}' regions; highly-curved M5-branes; and a coordinate singularity called the ''cap''. By putting these ''Lego'' pieces together we recover all known global regular solutions with the above symmetry, including the self-dual strings on M5 for ? <0, and the Janus solution for ? > 0, but now promoted to families parametrized by vertical stroke ? vertical stroke. We also construct exactly new regular solutions which are asymptotic to AdS{sub 4}/Z{sub 2} for ? < 0, and conjecture that they are a different superconformal limit of the self-dual string. Finally, we construct exactly ? > 0 solutions with highly curved M5-brane regions, which are the formal continuation of the self-dual string solutions across the decompactification point at ? = 0. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Chiral sound waves from a gauge theory of 1D generalized statistics
Rabello, Silvio J. Benetton
1996-01-01
A topological gauge field theory in one spatial dimension is studied, with the gauge fields as generators of two commuting U(1) Ka\\u{c}-Moody algebras. Coupling of these gauge fields to nonrelativistic bosonic matter fields, produces a statistical transmutation of the later, as in the Chern-Simons theory in two dimensions. The sound waves of the model are investigated and proven to be chiral bosonic excitations, with the same spectrum as the density fluctuations of the Lutti...
EQUIVA, Few-Group Diffusion Parameter for PWR Reflector Region by 1-D Transport Calculation
International Nuclear Information System (INIS)
1 - Description of program or function: EQUIVA-1 generates few-group equivalent diffusion theory parameters for pressurized water (PWR) reflector regions from the results of simple one-dimensional (slab) multigroup transport calculations. The one-dimensional 'normalized generalized equivalence theory' (NGET) method is used for this purpose. Equivalent parameters can be generated for any number of condensed energy groups and for different material regions, such as for the explicit baffle and water reflector of the radial reflector of a PWR, or for the homogenized baffle/reflector. EQUIVA-2 generates environment-insensitive equivalent diffusion theory parameters for pressurized water (PWR) reflector regions from the results of simple one-dimensional (slab) multigroup transport calculations. The one-dimensional reflector models have been implemented, namely the few-group NGET-RM method and the two-group KOEBKE-RM method. Equivalent parameters can be generated for one homogenized region only, although this region itself may be constituted by any number of component regions. 2 - Method of solution: EQUIVA-1: Analytic functions of non-symmetric real matrices are computed by means of a spectral analysis method. EQUIVA-2: Analytic functions of non-symmetric real matrices are computed by means of a spectral analysis method. Component region slab response matrices are combined using rigorous addition rules to obtain a global response matrix for a single region/node. 3 - Restrictions on the complexity of the problem: EQUIVA-1.1 is a variably dimensioned code and there is no restriction on the number of energy groups, etc. The size of the problem is restricted only by the computer core storage available. EQUIVA-2.0 is a variably dimensioned code and there is no restriction on the number of energy groups, etc. The size of the problem is restricted only by the computer core storage available
International Nuclear Information System (INIS)
The flow conditions in a steam generator for a PWR, where the primary medium is passed through a U-tube bundle, are to be improved without increasing the flow resistance by providing a channel, narrowing towards the tube sheet, in the tube lane formed by the tube bundle. By this a forced afflux of feedwater, and also a better cooling of the tube sheet will be achieved. With the aid of a flow restrictor the distribution of the feedwater may be controlled. Datails of the design are described. (UWI)
International Nuclear Information System (INIS)
The invention pertains to a steam generator, especially for pressurized-water reactors (PWR), with two U-bundles of tubes, the shanks of which are facing each other, and the tube plates of which are connected by common inlet and outlet chambers for the primary medium passing the tubes of the U-bundle of tubes, whereby separate zones are provided for preheating, evaporation and superheating of a secondary medium and whereby a trap is lined up before the superheater zone. (orig./TK)
Jenkins, Nick; Crossley, Peter
2000-01-01
The use of combined heat and power (CHP) plants and renewable energy sources reduces the amount of greenhouse gases released into the atmosphere and helps to alleviate the consequent climate change. The policies of many governments suggest that the proportion of electrical energy produced by these sources will increase dramatically over the next two decades. Unlike traditional generating units, these new types of power plant are usually 'embedded' in the distribution system or 'dispersed' around the network. As a result, conventional design and operating practices are no longer applicable; for
Novel hollow mesoporous 1D TiO2 nanofibers as photovoltaic and photocatalytic materials
Zhang, Xiang; Thavasi, Velmurugan; Mhaisalkar, S. G.; Ramakrishna, Seeram
2012-02-01
Hollow mesoporous one dimensional (1D) TiO2 nanofibers are successfully prepared by co-axial electrospinning of a titanium tetraisopropoxide (TTIP) solution with two immiscible polymers; polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP) using a core-shell spinneret, followed by annealing at 450 °C. The annealed mesoporous TiO2 nanofibers are found to having a hollow structure with an average diameter of 130 nm. Measurements using the Brunauer-Emmett-Teller (BET) method reveal that hollow mesoporous TiO2 nanofibers possess a high surface area of 118 m2 g-1 with two types of mesopores; 3.2 nm and 5.4 nm that resulted from gaseous removal of PEO and PVP respectively during annealing. With hollow mesoporous TiO2 nanofibers as the photoelectrode in dye sensitized solar cells (DSSC), the solar-to-current conversion efficiency (?) and short circuit current (Jsc) are measured as 5.6% and 10.38 mA cm-2 respectively, which are higher than those of DSSC made using regular TiO2 nanofibers under identical conditions (? = 4.2%, Jsc = 8.99 mA cm-2). The improvement in the conversion efficiency is mainly attributed to the higher surface area and mesoporous TiO2 nanostructure. It facilitates the adsorption of more dye molecules and also promotes the incident photon to electron conversion. Hollow mesoporous TiO2 nanofibers with close packing of grains and crystals intergrown with each other demonstrate faster electron diffusion, and longer electron recombination time than regular TiO2 nanofibers as well as P25 nanoparticles. The surface effect of hollow mesoporous TiO2 nanofibers as a photocatalyst for the degradation of rhodamine dye was also investigated. The kinetic study shows that the hollow mesoporous surface of the TiO2 nanofibers influenced its interactions with the dye, and resulted in an increased catalytic activity over P25 TiO2 nanocatalysts.Hollow mesoporous one dimensional (1D) TiO2 nanofibers are successfully prepared by co-axial electrospinning of a titanium tetraisopropoxide (TTIP) solution with two immiscible polymers; polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP) using a core-shell spinneret, followed by annealing at 450 °C. The annealed mesoporous TiO2 nanofibers are found to having a hollow structure with an average diameter of 130 nm. Measurements using the Brunauer-Emmett-Teller (BET) method reveal that hollow mesoporous TiO2 nanofibers possess a high surface area of 118 m2 g-1 with two types of mesopores; 3.2 nm and 5.4 nm that resulted from gaseous removal of PEO and PVP respectively during annealing. With hollow mesoporous TiO2 nanofibers as the photoelectrode in dye sensitized solar cells (DSSC), the solar-to-current conversion efficiency (?) and short circuit current (Jsc) are measured as 5.6% and 10.38 mA cm-2 respectively, which are higher than those of DSSC made using regular TiO2 nanofibers under identical conditions (? = 4.2%, Jsc = 8.99 mA cm-2). The improvement in the conversion efficiency is mainly attributed to the higher surface area and mesoporous TiO2 nanostructure. It facilitates the adsorption of more dye molecules and also promotes the incident photon to electron conversion. Hollow mesoporous TiO2 nanofibers with close packing of grains and crystals intergrown with each other demonstrate faster electron diffusion, and longer electron recombination time than regular TiO2 nanofibers as well as P25 nanoparticles. The surface effect of hollow mesoporous TiO2 nanofibers as a photocatalyst for the degradation of rhodamine dye was also investigated. The kinetic study shows that the hollow mesoporous surface of the TiO2 nanofibers influenced its interactions with the dye, and resulted in an increased catalytic activity over P25 TiO2 nanocatalysts. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11251e
Measurement of the Deuteron Spin Structure Function g1d(x) for 1 (GeV/c)2 2 2
International Nuclear Information System (INIS)
New measurements are reported on the deuteron spin structure function g1d. These results were obtained from deep inelastic scattering of 48.3 GeV electrons on polarized deuterons in the kinematic range 0.01 2 2. These are the first high dose electron scattering data obtained using lithium deuteride (6Li2H) as the target material. Extrapolations of the data were performed to obtain moments of g1d, including ?1d, and the net quark polarization ? ?
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
Scientific Electronic Library Online (English)
Roque E. da C. de, Pinho; Jarbas H. de, Miranda.
2014-10-01
Full Text Available A preocupação com o destino de produtos químicos e água, aplicados ao solo, tem motivado vários pesquisadores a desenvolverem e aplicarem modelos teóricos, a fim de descrever os processos físicos envolvidos no transporte desses produtos no perfil do solo. Nesse sentido, esta pesquisa teve como objet [...] ivo aplicar o modelo HYDRUS-1D, bem como avaliar sua performance, em simulações do deslocamento do potássio e água (umidade do solo), em colunas segmentadas, preenchidas com dois tipos de solos tropicais, em condições não saturadas (Latossolo Vermelho- - Amarelo e Nitossolo Vermelho). Os parâmetros de transporte do potássio foram obtidos por meio de curvas de distribuição de efluentes (Breakthrough Curves (BTC)). O desempenho do modelo foi avaliado com base nos seguintes parâmetros estatísticos: erro máximo, erro absoluto médio, raiz quadrada do erro médio normalizado, coeficiente de massa residual, coeficiente de determinação, eficiência e índice de concordância de Willmott. Diante dos resultados obtidos, pôde-se concluir que o modelo HYDRUS-1D foi eficiente nas simulações de deslocamento do potássio e da água, em relação aos dois materiais de solo estudados. Abstract in english The need to better understand and predict the fate and transport of water and various dissolved contaminants in tropical soils has motivated the development of theoretical models describing the basic physical and biogeochemical processes involved. This research aimed to evaluate the performance of t [...] he HYDRUS-1D software package to simulate water and potassium movement in segmented columns filled with two tropical soil types, a red-yellow Latosol (LVA) and a Nitosol (NV), during unsaturated flow conditions. The potassium transport parameters were estimated from observed solute breakthrough curves. Model performance was evaluated using several statistical criteria: maximum error, mean absolute error, root mean square standard error, coefficient of residual mass, coefficient of determination, efficiency and the Willmott agreement index. Results showed that the HYDRUS-1D model was very efficient in simulating the movement of water and potassium in the two soils.
DEFF Research Database (Denmark)
Goldstone, J.V.; Jönsson, M.E.; Behrendt, Lars; Woodin, B.R.; Jenny, M.J.; Nelson, D.R.; Stegeman, J.J.
2009-01-01
Enzymes in the cytochrome P450 1 family oxidize many common environmental toxicants. We identified a new CYP1, termed CYP1D1, in zebrafish. Phylogenetically, CYP1D1 is paralogous to CYP1A and the two share 45% amino acid identity and similar gene structure. In adult zebrafish, CYP1D1 is most highly expressed in liver and is relatively highly expressed in brain. CYP1D1 transcript levels were higher at 9 h post-fertilization than at later developmental times. Treatment of zebrafish with potent ary...
PT phase transition in a (2+1)-d relativistic system
Mandal, Bhabani Prasad; Ali, Kawsar; Ghatak, Ananya
2015-01-01
We study a massless Dirac particle with PT symmetric non-Hermitian Rashba interaction in the background of Dirac oscillator potential to show the PT phase transition in a (2+1) dimensional relativistic system analytically. PT phase transition occurs when strength of the (i) imaginary Rashba interaction or (ii) transverse magnetic field exceed their respective critical values. Small mass gap in the spectrum, consistent with other approaches is generated as long as the system is in the unbroken phase. Relativistic Landau levels are constructed explicitly for such a system.
Viscous shear heating instabilities in a 1-D viscoelastic shear zone
Homburg, J. M.; Coon, E. T.; Spiegelman, M.; Kelemen, P. B.; Hirth, G.
2010-12-01
Viscous shear instabilities may provide a possible mechanism for some intermediate depth earthquakes where high confining pressure makes it difficult to achieve frictional failure. While many studies have explored the feedback between temperature-dependent strain rate and strain-rate dependent shear heating (e.g. Braeck and Podladchikov, 2007), most have used thermal anomalies to initiate a shear instability or have imposed a low viscosity region in their model domain (John et al., 2009). By contrast, Kelemen and Hirth (2007) relied on an initial grain size contrast between a predetermined fine-grained shear zone and coarse grained host rock to initiate an instability. This choice is supported by observations of numerous fine grained ductile shear zones in shallow mantle massifs as well as the possibility that annealed fine grained fault gouge, formed at oceanic transforms, subduction related thrusts and ‘outer rise’ faults, could be carried below the brittle/ductile transition by subduction. Improving upon the work of Kelemen and Hirth (2007), we have developed a 1-D numerical model that describes the behavior of a Maxwell viscoelastic body with the rheology of dry olivine being driven at a constant velocity at its boundary. We include diffusion and dislocation creep, dislocation accommodated grain boundary sliding, and low-temperature plasticity (Peierls mechanism). Initial results suggest that including low-temperature plasticity inhibits the ability of the system to undergo an instability, similar to the results of Kameyama et al. (1999). This is due to increased deformation in the background allowing more shear heating to take place, and thus softening the system prior to reaching the peak stress. However if the applied strain rate is high enough (e.g. greater than 0.5 x 10-11 s-1 for a domain size of 2 km, an 8 m wide shear zone, a background grain size of 1 mm, a shear zone grain size of 150 ?m, and an initial temperature of 650°C) dramatic instabilities can occur. The instability is enhanced by the development of a self-localizing thermal perturbation in the fine grained zone that is narrower than the original width of the fine-grained zone. To examine the effect of melting, we include a parameterization of partially molten rock viscosity as a function of temperature assuming a simple relationship between melt fraction and temperature. At T > ~1400°C, all other deformation mechanisms are deactivated but shear heating continues, allowing for continued temperature evolution. In addition a strain rate cap proportional to the shear wave velocity in olivine has been imposed, reflecting the maximum rate that changes in stress can be communicated through the system. While Kelemen and Hirth (2007) allowed for grain size evolution, this has not yet been implemented in our model. Adding grain size evolution as an additional strain softening mechanism would probably allow instabilities to develop at more geologically reasonable applied strain rates. In addition to discussing the stability of the olivine only system, we will explore grain size evolution during system evolution and evaluate the consequences that the grain size evolution and lithology have on the stability of the system.
Energy Technology Data Exchange (ETDEWEB)
Langham, G.
1997-09-01
In March next year the contracts to supply coal to United Kingdom power stations - contracts which the coal producers inherited with privatisation in December 1994 - come to an end. The power stations are by far the biggest consumers of UK coal - 75% of total production goes to the generators - and, as nationalised industries, traditionally provided a guaranteed market for coal. Now the producers and consumers are in the private sector and new deals currently being struck are tending to give the coal companies a less secure future. The article gives comments on the future of industry from the Coal Authority, the Coalfield Communities Campaign and other industry associations and coal mining companies. 9 photos.
Energy Technology Data Exchange (ETDEWEB)
Wang, Zhong L; Fan, Fengru; Lin, Long; Zhu, Guang; Pan, Caofeng; Zhou, Yusheng
2015-11-03
A generator includes a thin first contact charging layer and a thin second contact charging layer. The thin first contact charging layer includes a first material that has a first rating on a triboelectric series. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer includes a second material that has a second rating on a triboelectric series that is more negative than the first rating. The thin first contact charging layer has a first side with a first conductive electrode applied thereto and an opposite second side. The thin second contact charging layer is disposed adjacent to the first contact charging layer so that the second side of the second contact charging layer is in contact with the second side of the first contact charging layer.
Algorithmic Scalability of Constrained Parallel Conservative Discrete Event Simulations in 1-D
Kolakowska, Alice; Novotny, Mark; Korniss, Gyorgy
2002-08-01
We consider the parallel simulation of asynchronous systems employing processing elements that are arranged on a ring and that communicate only among nearest neighbors. Each processor has its own local simulated time. A processor is allowed to update its local time if it is guaranteed not to violate causality. Otherwise, it remains idle. At each simultaneously performed parallel update step, the utilization is defined as the fraction of non-idling processors and the simulated time horizon (STH) is defined as the set of local times generated at all sites. In the limit of large systems utilization scales with the system size; however, the width of the STH (i.e., measurement phase of the algorithm) diverges (Korniss et al, PRL 84). In this presentation, we introduce a technique of a moving window, which modifies the algorithm by imposing a global constraint on the times generated at sites locally. Our studies indicate that discrete event simulations with the constraint of a moving window are scalable. This result may find numerous applications in modeling the evolution of general spatially extended interacting systems, including dynamic Monte Carlo studies. This work is supported in part by NSF grant DMR-0113049.
1D study of radiation-dominated implosion of a cylindrical tungsten plasma column
Basko, M M; Murakami, M; Novikov, V G; Grushin, A S
2011-01-01
Spectral properties of the x-ray pulses, generated by perfectly uniform cylindrical implosions of tungsten plasma with parameters typical of wire array z-pinches, are investigated under the simplifying assumption that the final stage of the kinetic-to-radiant energy conversion is not affected by the magnetic field. The x-ray emission is shown to be generated within a narrow (sub-micron) radiation-dominated stagnation shock front with a "supercritical" amplitude. The structure of the stagnation shock is investigated by using two independent radiation-hydrodynamics codes, and by constructing an approximate analytical model. The x-ray spectra are calculated for two values of the plasma column mass, 0.3 mg/cm and 6 mg/cm, with a newly developed two-dimensional radiation-hydrodynamics code RALEF-2D. The hard component of the spectrum (with a blackbody-fit temperature of 0.5-0.6 keV for the 6-mg/cm mass) originates from a narrow peak of the electron temperature inside the stagnation shock. The softer main component...
Gao, Junjie; Xie, Long; Zhang, Hao; Yu, Jidong; Wang, Ganghua; Liu, Gaomin; Gu, Yanqin; He, Hongliang; Bai, Jingsong
2015-11-01
The effects of hydrostatic and one-dimensional (1D) compression pressure on the phase transition of perovskite ferroelectric crystal were comparably investigated via the measurement of polarization P r with respect to applied pressure and the Landau-Devonshire (LD) phenomenological approach. The results showed that hydrostatic pressure can induce ferroelectric-to-paraelectric phase transition, while 1D compression can stablize the ferroelectric phase. This phenomenon was very different from the phase transitions of metal crystals, such as iron. In the framework of LD phenomenological theory, this phenomenon is believed to be associated with the strong anisotropy and electromechanical coupling which exists in ferroelectrics under high pressure. On the other hand, the piezoelectric stress coefficient e 31 and piezoelectric strain coefficient d h for PIN-PMN-PT crystal were obtained as??-2.9 C m-2 and 80 pC N-1, respectively.
Design and Implementation of 4T, 3T and 3T1D DRAM Cell Design on 32 NM Technology
Directory of Open Access Journals (Sweden)
Prateek Asthana
2014-08-01
Full Text Available n this paper average power consumption, write acce ss time, read access time and retention time of dra m cell designs have been analyzed for the nano-meter scale memories. Many modern day processors use dram cell for on chip data and program memory stora ge. The major power in dram is the off state leakag e current. Improving on the power efficiency of a dra m cell is critical for the improvement in average p ower consumption of the overall system. 3T dram cell, 4T dram and 3T1D DRAM cells are designed with the schematic design technique and their average power consumption are compared using TANNER EDA tool .average power consumption, write access time, read access time and retention time of 4T, 3T dram and 3T1D DRAM cell are simulated and compared on 32 nm technology.
Kong, Jie; Qiao, Ke; Sabo, Hannah; Matthews, Lorin; Hyde, Truell
2013-10-01
When confined in a glass box placed on the lower powered electrode of a GEC rf reference cell, dust particles immersed in plasma can form vertically aligned 1D chains. Both the formation and subsequent structural changes within this vertically aligned dust chain are controlled by the rf power, since the rf power effects the ionization rate in the cell, the screening parameter and the charge on the dust particles. In this study, oscillations of a 1D vertically aligned dust particle chain are employed to investigate the dust charge and screening length through measurement of the resonance frequency. It will be shown that the relationship between the sloshing and breathing frequencies indicates that the ion streaming effect plays an important role in vertical oscillations and must be included in any structural analysis of the system.
1D iron(II) spin crossover complexes with 1,2,4-triazol-4-yl-propanoic acid
International Nuclear Information System (INIS)
A series of 1D coordination polymers [Fe(patrz)3]X2·solv, (patrz = 1,2,4-triazol-4-yl-propanoic acid; X = BF4-, ClO4-, Cl???, NO3-bar and solv = MeOH or H2O) were precipitated from methanol. Their spin crossover properties were studied by temperature dependent SQUID magnetometry and 57Fe Mössbauer spectroscopy, both for solvated and desolvated complexes. Compounds show gradual incomplete spin crossover with distinct thermochromism, in particular [Fe(patrz)3](BF4)2·MeOH, for which only 27% of FeII ions are switched to the low-spin state at 77 K, as determined by a detailed 57Fe Mössbauer study. Other prominent features of this work are the interesting self assembly of 1D chain with exclusively triazole coordination from patrz ligand despite its ditopic nature and a hysteretic room temperature spin crossover in [Fe(patrz)3]Cl2.
Design and Implementation of 4T, 3T and 3T1D DRAM Cell Design on 32 NM Technology
Directory of Open Access Journals (Sweden)
Prateek Asthana
2014-08-01
Full Text Available In this paper average power consumption, write access time, read access time and retention time of dram cell designs have been analyzed for the nano-meter scale memories. Many modern day processors use dram cell for on chip data and program memory storage. The major power in dram is the off state leakage current. Improving on the power efficiency of a dram cell is critical for the improvement in average power consumption of the overall system. 3T dram cell, 4T dram and 3T1D DRAM cells are designed with the schematic design technique and their average power consumption are compared using TANNER EDA tool .average power consumption, write access time, read access time and retention time of 4T, 3T dram and 3T1D DRAM cell are simulated and compared on 32 nm technology.