Lunar seismograms are distinctly different from their terrestrial counterparts. The Apollo lunar seismometers recorded moonquakes without distinct P- or S-wave arrivals; instead waves arrive as a diffuse coda that decays over several hours making the identification of body waves difficult. The unusual character of the lunar seismic wavefield is generally tied to properties of the megaregolith: it consists of highly fractured and broken crustal rock, the result of extensive bombardment of the Moon. The megaregolith extends several kilometers into the lunar crust, possibly into the mantle in some regions, and is covered by a thin coating of fine-scale dust. These materials possess very low seismic velocities that strongly scatter the seismic wavefield at high frequencies. Directly modeling the effects of the megaregolith to simulate an accurate lunar seismic wavefield is a challenging computational problem, owing to the inherent 3-D nature of the problem and the high frequencies (>1 Hz) required. Here we focus on modeling the long duration coda, studying the effects of the low velocities found in the megaregolith. We produce synthetic seismograms using 1-D slowness integration methodologies, GEMINI and reflectivity, and a 3-D Cartesian finite difference code, Wave Propagation Program, to study the effect of thin layers of low velocity on the surface of a planet. These codes allow us generate seismograms with dominant frequencies of ~1 Hz. For background lunar seismic structure we explore several models, including the recent model of Weber et al., Science, 2011. We also investigate variations in megaregolithic thickness, velocity, attenuation, and seismogram frequency content. Our results are compared to the Apollo seismic dataset, using both a cross correlation technique and integrated envelope approach to investigate coda decay. We find our new high frequency results strongly support the hypothesis that the long duration of the lunar seismic codas is generated by the presence of the low velocity megaregolith, and that the diffuse arrivals are a combination of scattered energy and multiple reverberations within this layer. The 3-D modeling indicates the extreme surface topography of the Moon adds only a small contribution to scattering effects, though local geology may play a larger role. We also study the effects of the megaregolith on core reflected and converted phases and other body waves. Our analysis indicates detection of core interacting arrivals with a polarization filter technique is robust and lends the possibility of detecting other body waves from the Moon. These predictive techniques are powerful tools for understanding the character of a planetary seismic wavefield. Modeling the effects of subsurface oceans, impact modified surfaces, and other highly fractured materials will provide advance details, such as frequency content and sensitivity, shadow zones, and other useful constraints for designing science goals for instrumentation deployed in new missions.

Listening to a sound representing ground motion is valuable to understand an earthquake intuitively compared with only seeing a waveform. In this paper, we propose a new method to make a sound of earthquake, in which several rules different from existing methods are used. In our new method, a sound of earthquake is generated by modifying the frequency information of generating function based on the theory of symmetric Fourier analysis. Applying the method to the JMA Kobe seismogram in 1995 South Hyogo Prefecture Earthquake and predicted waveform at Sannomaru, Nagoya, in future Tokai and Tonankai earthquake, three features of the sound generated by this method are confirmed: the sound has same duration time as the seismogram, high sound is heard when the seismogram has high frequency, and loud sound is heard when the seismogram has large amplitude.   

An introductory study of the inverse seismic problem is performed. The complex cepstrum of a seismogram generated by the convolution of three factors, the Seggern-Blandford source function of an explosion, the Futterman mantle transfer function, and the SRO seismometer transfer function, is used. For a given Q and yield, a synthetic seismogram is computed. Arbitrary values of Q and yield are introduced, and a search is conducted to find that pair of values that minimized the cepstral difference between the original and arbitrary seismograms. The original values are accurately recovered. Spectral and amplitude characteristics of the various factors are presented. Possible application to the problem of studying a medium intervening between a source and receiver is discussed. 25 figures, 1 table.

Material on reflection seismology emphasizing petroleum exploration while also including applications related to coal exploration, uranium exploration and geothermal prospects is presented. The physical concepts dealing with surface-wave generation and dispersion, migration of seismic reflections, synthetic seismograms and Vibroseis sources are discussed.

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)

SUMMARY We have developed a near real-time system for the simulation of global earthquakes. Prompted by a trigger from the Global Centroid Moment Tensor (CMT) Project, the system automatically calculates normal-mode synthetic seismograms for the Preliminary Reference Earth Model, and spectral-element synthetic seismograms for 3-D mantle model S362ANI in combination with crustal model Crust2.0. The 1-D and 3-D synthetics for more than 1800 seismographic stations operated by members of the international Federation of Digital Seismograph Networks are made available via the internet (global.shakemovie.princeton.edu) and the Incorporated Research Institutions for Seismology Data Management Center (IRIS; iris.edu). The record length of the synthetics is 100 min for CMT events with magnitudes les...

Correlations between physical properties and seismic reflection data are useful to determine the geological nature of seismic reflections and the lateral extent of geological strata. The difference in resolution between well logs and seismic data is a major hurdle faced by seismic interpreters when tying both data sets. In general, log data have a resolution of at least two orders of magnitude greater than seismic data. Smoothing physical property logs improves correlation at the seismic scale. Three different approaches were used and compared to smooth a density log: binomial filtering, seismic wavelet filtering and discrete wavelet transform (DWT) filtering. Regression plots between the density logs and the acoustic impedance show that the data smoothed with the DWT is the only method that preserves the original relationship between the raw density data and the acoustic impedance. Smoothed logs were then used to generate synthetic seismograms that were tied to seismic data at the borehole site. Best ties were achieved using the synthetic seismogram computed with the density log processed with the DWT. The good performance of the DWT is explained by its adaptive multi-scale characteristic which preserved significant local changes of density on the high-resolution data series that were also pictured at the seismic scale. Since synthetic seismograms are generated using smoothed logs, the choice of the smoothing method impacts on the quality of seismic-to-well ties. This ultimately can have economical implications during hydrocarbon exploration or exploitation phases.

Hale and Cohen (1991) developed software to generate two-dimensional computer models of complex geology. Their method uses a triangulation technique designed to support efficient and accurate computation of seismic wavefields for models of the earth`s interior. Subsequently, Hale (1991) used this triangulation approach to perform dynamic ray tracing and create synthetic seismograms based on the method of Gaussian beams. Here, I extend this methodology to allow an increased variety of ray-theoretical experiments. Specifically, the developed program GBmod (Gaussian Beam MODeling) can produce arbitrary multiple sequences and incorporate attenuation and density variations. In addition, I have added an option to perform Fresnel-volume ray tracing (Cerveny and Soares, 1992). Corrections for reflection and transmission losses at interfaces, and for two-and-one-half-dimensional (2.5-D) spreading are included. However, despite these enhancements, difficulties remain in attempts to compute accurate synthetic seismograms if strong lateral velocity inhomogeneities are present. Here, these problems are discussed and, to a certain extent, reduced. I provide example computations of high-frequency seismograms based on the method of Gaussian beams to exhibit the advantages and disadvantages of the proposed modeling method and illustrate new features for both surface and vertical seismic profiling (VSP) acquisition geometries.

We study array seismograms of French nuclear explosions from two Islands in French-Polynesia and use these to constrain the structure in the upper mantle beneath the islands. Seismograms of nuclear explosions on the hot-spot related Fangataufa atoll show discrete, large-amplitude \\textit{P}-coda phases which are not observed in recordings of explosions from Mururoa ~40~km to the north. We are able to locate the source for these \\textit{P}-coda phases beneath the Fangataufa atoll, indicating structural heterogeneities in this oceanic region on very small scale-lengths most likely produced by the Pitcairn hot-spot. Synthetic seismograms for models of the upper mantle beneath Fangataufa require a layer with \\textit{P}-wave velocity elevated by ~10% between depths of 51~km and 85~km with a sharp northern boundary to match these \\textit{P}-coda phases. Few mineralogic scenarios exist that can explain this structure and the properties of this layer imply that extensive enrichment in garnet occurs in this depth range. The garnet-enriched layer is likely of similar origin to the well-known xenolithic ``garnet megacryst'' suite found in kimberlitic regions. We propose a model for the formation of the Fangataufa and Mururoa atolls involving garnet-enriched zones being generated at depth through magmatic processes involving extensive fractional crystallization, beneath the Pitcairn plume-head. Thus, the initiation of hot-spots could produce complex geochemical and structural heterogeneities at depth in the suboceanic mantle on lengthscales of a few tens of km's.

Indonesia has Indonesian Tsunami Early Warning System (Ina-TEWS) since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB) and Mj. If earthquake occurred in Ocean, depth 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purposes of this research are to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor sea, Banda sea, Arafura sea and Pasific ocean. We analyzed at least 330 vertical seismogram recorded by IRIS-DMC network using a direct procedure for rapid assessment of earthquake tsunami potential using simple measures on P-wave vertical seismograms on the velocity records, and the likelihood that the high-frequency, apparent rupture duration, Tdur. Tdur can be related to the critical parameters rupture length (L), depth (z), and shear modulus (?) while Tdur may be related to wide (W), slip (D), z or ?. Our analysis shows that the rupture duration has a stronger influence to generate tsunami than Mw and depth. The rupture duration gives more information on tsunami impact, Mo/?, depth and size than Mw and other currently used discriminants. We show more information which known from the rupture durations. The longer rupture duration, the shallower source of the earthquake. For rupture duration greater than 50 s, the depth less than 50 km, Mw greater than 7, the longer rupture length, because Tdur is proportional L and greater Mo/?. Because Mo/? is proportional L. So, with rupture duration information can be known information of the four parameters. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 4-5 min after an earthquake occurs and thus can aid in effective, accuracy and reliable tsunami early warning for Indonesia region.

Summary An approach to detect afterslips in the source process of giant earthquakes is presented in the normal-mode frequency band (0.3-2.0-mHz). The method is designed to avoid a potential systematic bias problem in the determination of earthquake moment by a typical normal-mode approach. The source of bias is the uncertainties in Q (modal attenuation parameter) which varies by up to about 10-per cent among published studies. A choice of Q values within this range affects amplitudes in synthetic seismograms significantly if a long time-series of about 5-7 d is used for analysis. We present an alternative time-domain approach that can reduce this problem by focusing on a shorter time span with a length of about 1 d. Application of this technique to four recent giant earthquakes is presente...

Shear (S)-wave velocity is a key property of near-surface materials and is the fundamental parameter for many environmental and engineering geophysical studies. Directly acquiring accurate S-wave velocities from a seismic shot gather is usually difficult due to the poor signal-to-noise ratio. The relationship between Rayleigh-wave phase velocity and frequency has been widely utilized to estimate the S-wave velocities in shallow layers using the multichannel analysis of surface waves (MASW) technique. Hence, Rayleigh wave is a main focus of most near-surface seismic studies. Conventional dispersion analysis of Rayleigh waves assumes that the earth is laterally homogeneous and the free surface is horizontally flat, which limits the application of surface-wave methods to only 1D earth models or very smooth 2D models. In this study I extend the analysis of Rayleigh waves to a 2D domain by employing the 2D full elastic wave equation so as to address the lateral heterogeneity problem. I first discuss the accurate simulation of Rayleigh waves through finite-difference method and the boundary absorbing problems in the numerical modeling with a high Poisson's ratio (> 0.4), which is a unique near-surface problem. Then I develop an improved vacuum formulation to generate accurate synthetic seismograms focusing on Rayleigh waves in presence of surface topography and internal discontinuities. With these solutions to forward modeling of Rayleigh waves, I evaluate the influence of surface topography to conventional dispersion analysis in 2D and 3D domains by numerical investigations. At last I examine the feasibility of inverting waveforms of Rayleigh waves for shallow S-wave velocities using a genetic algorithm. Results of the study show that Rayleigh waves can be accurately simulated in near surface using the improved vacuum formulation. Spurious reflections during the numerical modeling can be efficiently suppressed by the simplified multiaxial perfectly matched layers. The conventional MASW method can tolerate gentle topography changes with insignificant errors. Finally, many near-surface features with strong lateral heterogeneity such as dipping interfaces, faults, and tunnels can be imaged by the waveform inversion of Rayleigh waves for shallow S-wave velocities. This thesis consists of four papers that are either published (chapter 1) or in review (chapter 2, 3, and 4) for consideration of publication to peer-refereed journals. Each chapter represents a paper, and therefore inadvertently there will be a certain degree of overlap between chapters (particularly for the introduction parts, where references to many common papers occur).

The crust and uppermost mantle below the large positive gravity anomaly in the central part of the Norwegian-Danish Basin, the Silkeborg Gravity High (SGH), is investigated using controlled source seismic data. A more than 80 km long and ~ 20 km thick intrusion is interpreted. The seismic velocity within the intrusion varies from 6.8 km/s at the top (12 km depth) to 7.2-7.7 km/s at the Moho level (30-31 km depth). The characteristics of the Moho reflectivity vary along the profile. Below the central part of the intrusion, the Moho reflectivity is very weak, due to a small velocity contrast between the lowermost crust (7.7 km/s) and the uppermost mantle (7.9-8.0 km/s). The seismic data show a "ringing" Moho below the western part of the intrusion. The coda trailing the main PmP reflection is about 1.0 s long and is composed of 4-5 wavelets. We demonstrate that this feature may be explained by a layered transition zone between 30 and 35 km depth, where high-velocity layers of mantle affinity (7.9-8.05 km/s) alternate with layers of typical lower crustal velocity (6.7-7.3 km/s). The characteristics of this layering, which causes thePmP coda, are modelled by matching synthetic seismograms to the observed data. Synthetic seismograms, calculated using the reflectivity method for 1D models, constrain the nominal layer thickness to 100-500 m. Waveform modelling in 2D constrains the layered internal structure of the transition zone and the length of the heterogeneous zone along the profile. We interpret the layered crust-mantle transition zone as solidified melts of mantle affinity, which were intruded into the lowermost crust. The layered zone is proposed to be associated with the extensional tectonism that occurred in the area in Late Carboniferous-Early Permian, which also caused the large crustal intrusion. The subsequent cooling may have initiated the formation of the Danish Basin.

The use of paleosols as sequence boundary markers has recently been shown to be one of the most important tools for the interpretation of seismic data in regions of continental Cenozoic basin-fill material. Calcic paleosols and their defined sequence boundaries have been previously mapped on the surface and tied to seismic reflection data, and now can be delineated on well logs. Analyses of sonic and density logs from wells in the Deerlodge Valley, southwestern Montana, has resulted in the identification of several relatively thin, high velocity/high density zones which exist within the Cenozoic basin-fill. Zone thickness varies from 1 to 1.5 meters, and the zones are stacked up to as much as 40 meters. Density changes within the zones up to 0.6 g/cm[sup 3]. Velocity changes up to 1,660 meters/second. Well cutting chips from the high velocity/high density zones exhibit pedogenic features associated with calcic paleosols, such as clastic grains floating in micrite, grains corroded by calcite, and calcified root filaments. The authors generate synthetic seismograms from the sonic and density well logs which they analyze, and tie the seismograms to seismic reflection data using bright reflectors. The bright reflectors are interpreted as sequence boundaries on the seismic data and can be projected to the surface where they are associated with stacked zones of calcic paleosols which mark surface sequence boundaries.

This was the seventh quarter of the contract. During this quarter we (1) continued the large task of processing the seismic data, (2) collected additional geological information to aid in the interpretation, (3) tied the well log data to the seismic via generation of synthetic seismograms, (4) began integrating regional structural information and fracture trends with our observations of structure in the study area, (5) began constructing a velocity model for time-to-depth conversion and subsequent AVO and raytrace modeling experiments, and (6) completed formulation of some theoretical tools for relating fracture density to observed elastic anisotropy. The study area is located at the southern end of the Powder River Basin in Converse County in east-central Wyoming. It is a low permeability fractured site, with both gas and oil present. Reservoirs are highly compartmentalized due to the low permeabilities, and fractures provide the only practical drainage paths for production. The two formations of interest are: The Niobrara: a fractured shale and limey shale to chalk, which is a reservoir rock, but also its own source rock. The Frontier: a tight sandstone lying directly below the Niobrara, brought into contact with it by an unconformity. A basemap is presented with the seismic lines being analyzed for this project plus locations of 13 wells that we are using to supplement the analysis. The arrows point to two wells for which we have constructed synthetic seismograms.

Incorporating new technologies into science education that help students comprehend complex content more efficiently and accurately is valuable to teachers and students. I present a seismology lesson developed for high school and introductory undergraduate Earth science courses that utilizes the new seismic analysis software SeismicCanvas. The lesson follows in the footsteps of previous seismic analysis lessons with the goals of exciting students about seismology and demonstrating the importance of seismology to society; however the new software removes the requirement for command line knowledge. The first part of the lesson introduces students to seismograms and earthquakes. The second part familiarizes students with SeismicCanvas. The third part puts it all together. After processing recent earthquake data downloaded from IRIS, students pick first arrivals. Starting with a homogeneous 1D Earth model, the students compare their picks to modeled picks while intuitively gaining insight into Earth's 1D structure, modeling, and inversion. Finally, I discuss extensions and the future of this lesson, focusing on and utilizing SeismicCanvas so that students comprehend the important underlying principles and physics while not getting stuck at the command line.

We have constructed a 3-D P and S velocity structure of the crust and uppermost mantle of China and surrounding areas using high quality first arrivals extracted from the Annual Bulletin of Chinese Earthquakes (ABCE). We used 345,000 P wave, and 230,000 shear wave arrivals. A preliminary 3-D model has been generated by combining 2400 1-D models (Sun et al., 2004). By applying the tomography method (Zhao et al., 1992), we obtain a detailed 3-D P and S wave velocity model of the crust and uppermost mantle in China with a spatial resolution of 1° × 1° in horizontal direction and 10 km in depth. This method is adaptable to a velocity structure which includes several complex-shaped velocity discontinuities and allows 3-D velocity variations everywhere in the model. Velocity discontinuities represent known geological boundaries such as the Moho and/or a subducting slab boundary, etc. A 3D grid net is set up in the model to express the 3D structure. Velocity perturbations at the grid nodes are taken as unknown parameters. The velocity perturbation at any point in the model is calculated by linearly interpolating the velocity perturbations at the eight grid nodes surrounding that point. To calculate travel times and ray paths accurately and rapidly, an efficient 3D ray-tracing technique is employed to iteratively use the pseudo-bending technique (Um and Thurder, 1987) and Snell's law. Station elevations and the sediment layers are taken into account in the ray tracing. The LSQR algorithm (Paige and Saunders, 1982) with a damping regularization is used to solve the large and sparse system of observation equations. Our tomographic model provides new insights into the geological structure and tectonics of the region, such as the lithological variations and large fault zones across the major geological terrenes. The velocity images of the upper crust represent the surface geological and topographic features accurately. Basins and the Tibetan Plateau are clearly depicted in our model. The crust beneath the Precambrian regions (Tarim Basin, Ordos Basin, Sichuan Basin and western half of Songliao Basin) shows high velocity anomalies. The highest velocity anomaly is beneath the Sichuan Basin. The Bohai Gulf shows both high and low velocity anomalies due to a major Cenozoic rift system through it. P velocities are lower in the lower crust beneath the northern part of the South China Block than that beneath the southern part of the South China Block. The Indochina Block demonstrates low velocities both in the crust and uppermost mantle due to volcanism. The Pn velocities in the Tibet area are higher than those in other areas largely due to thicker crust thickness. Both 3-D travel time and broadband seismogram fits show that our model is well determined and can be applied to determine the source parameters of earthquakes and to generate synthetic travel times.

An efficient modeling technique for transversely isotropic, inhomogeneous media, is developed using a mix of analytical equations and numerical calculations. The analytic equation for the raypath in a factorized transversely isotropic (FTI) media with linear velocity variation, derived by Shearer and Chapman, is used to trace between two points. In addition, I derive an analytical equation for geometrical spreading in FTI media that aids in preserving program efficiency; however, the traveltime is calculated numerically. I then generalize the method to treat general transversely isotropic (TI) media that are not factorized anisotropic inhomogeneous by perturbing the FTI traveltimes, following the perturbation ideas of Cerveny and Filho. A Kirchhoff-summation-based program relying on Trorey`s (1970) diffraction method is used to generate synthetic seismograms for such a medium. For the type of velocity models treated, the program is much more efficient than finite-difference and general ray-trace modeling techniques.

We have created several elastic 2-D models and are currently defining a complex 3D elastic salt model for distribution to the international research community for use in the calibration of AVO, polarization filtering, tomography, multicomponent seismic analysis, converted wave tomography, and seismic attribute analysis. We have also obtained the release of several real 2-D data sets corresponding to the 2-D models to test the robustness of any new techniques. In addition to the synthetic seismograms generated over these models, we will release the model definition of layers and rock properties to the research community so that others may modify them to include features beyond the scope of our current effort, such as gas clouds, fractures, and diagenetic changes. Finally, we expect these models to serve as a test bed for impmving the computational efficiency of elastic mode ling as a goal in itself.

In the applications of multichannel analysis of surface waves (MASW), dispersion curves are usually picked in an energy tracing manner on dispersion images. They are compared with the theoretical dispersion curves based on a horizontally layered earth model during the subsequent inversion for shear-wave velocities. Surface topography can strongly influence energy distribution on a dispersion image. In theory, static correction should be applied to seismic records before generating dispersion images if there are any elevation variations along a two-dimensional (2D) survey line. The out-of-plane noise from side areas of a survey line in three dimensions (3D) can also contaminate the recorded wavefield. We synthesize the seismograms through finite-difference modeling for 12 types of 2D earth ...

Seismic interpretations of crustal anisotropy often appear to be at odds with expectations based on structural geology. We provide a solution to the apparent discrepancy based on petrological data and synthetic seismograms and present results across the continental US. Seismic investigations of crustal anisotropy offer one of the best chances to observe lower crustal flow in situ, and receiver function (converted wave) studies have good horizontal and depth resolution and are less expensive than active source studies, and suffer from less tradeoff than tomographic studies. A puzzling observation in receiver function studies of the continental crust has been a prevalence of observed plunging axis anisotropy in subhorizontal layers interpreted to have accommodated a significant component of simple shear. In contrast, geological field observations and deformation experiments suggest that shear zones develop a significant boundary-parallel foliation (C-planes in S-C mylonite) after only modest amounts of strain accumulation (~gamma <3). The solution may lie in a preferential sensitivity of seismic waves. Receiver functions have ~5 times higher signal amplitudes for plunging compared to horizontal symmetry axis anisotropy. Even a small plunge (10-20 deg off horizontal) leads to a roughly twofold increase of signal amplitude compared to the horizontal symmetry axis case. For an S-C fabric with horizontal C and dipping S planes, the S fabric is well detected even for relatively small and realistic (3% - 6%) amounts of anisotropy. Horizontally aligned mica does not appear anisotropic to body waves, although it can be detected via radial anisotropy with surface waves. Amphibole alignment with a fast symmetry axis parallel to horizontal shear also produces a much weaker signal than in the plunging case. The behavior with backazimuth is also distinct. General S anisotropy and horizontal axis P anisotropy generate two pairs of relatively small amplitude peaks and troughs over the entire backazimuth range (hereinafter A2), while plunging P anisotropy shows a much higher amplitude single peak and trough (termed A1). Published crustal sample P versus S anisotropies range within a factor of 2 of each other, with the majority of samples showing comparable P and S anisotropy. While the A2 signal theoretically provides a robust detector for anisotropy, we suggest that a search for the larger A1 signal is more likely to be successful. We present seismic forward modeling results for petrological crustal deformation fabrics with aligned mica, amphibole, and quartz for different geometries. We also show results from the EarthScope Transportable Array across areas with presumed past or present lower crustal flow. When observed receiver function signal amplitudes are decomposed into A0 (isotropic, 1-D), A1, and A2 components, the A1 component dominates A2 by a factor of ~3 averaged across the entire network. The A1 component also contains information on isotropic dipping interfaces. However, isotropic dip and shallow structure such as sediment reverberations can theoretically be distinguished from deep anisotropic signals by matching the phase of early and late A1 arrivals. We present strategies to isolate the deep crustal fabric signal across the Transportable Array.

Several petrophysical models were constructed in order to evaluate the potential efficiency of AVO analysis based on the example of the Priobskoe Oilfield. Synthetic seismograms of different signal-to-noise ratios were calculated. AVO characteristics, such as the intercept and gradient, were obtained based on the evidence from these seismograms. The conditions under which AVO analysis could be used in further investigations were determined.

Abstract in portuguese Este artigo discute aspectos da aplicação prática da solução de problemas inversos sísmicos, baseados em modelos elásticos 1D de meio. A fim de melhor ajustar os modelos a observações reais, propomos utilizar uma decomposição estrutural, que permite transformar o campo de onda, correspondente a um modelo 3D, ao conjunto de dados, correspondentes a modelos 1D locais, com condições "ideais" de excitação e registro das oscilações sísmicas. Formando novos da (more) dos na forma de "pseudo" sismogramas, que são usados durante a transição no domínio espectral para a construção da solução do problema inverso correspondente. Além disso, a decomposição de formas de ondas correspondentes ao objeto alvo é realizada no domínio espectral. Esta decomposição permite eliminar as variações na forma de onda, associadas a mudanças nas condições de excitação e registro das oscilações sísmicas, bem como com a passagem pela parte superior da seção geológica.Em particular, esta decomposição leva em conta a mudança na forma de onda, devido a diferenças nas características de orientação da fonte real para diferentes ângulos de chegada ao objeto alvo. Abstract in english This article discusses aspects of practical application of the solution to inverse seismic problems based on 1D elastic models of the medium.In order to better fit the 1D models to real observations we propose using a structural decomposition. It allows us to transform the wave field, corresponding to a 3D model, to the wave field, corresponding to a set of local 1D models with "ideal" conditions of seismic oscillations excitation and registration. As a result, a new syst (more) em of observations in the form of "pseudo" seismograms, which are used during the transition into spectral domain for the solution of the corresponding inverse problem, can be available. In addition, the decomposition of waveforms corresponding to the target object is carried out in the spectral domain. This decomposition allows to eliminate variations in the waveform associated with the changes in the conditions of seismic oscillations excitation and registration, as well with the passage through the overlying medium. In particular, it takes into account the change in the waveform due to differences in the radiation patterns of the real source for different angles of arrival to the target object.

The research performed under this contract during the period 1 Oct. 1978 through 31 March 1979 can be divided into three main topics, upper mantle studies, propagational distortions caused by non-planar structure and S wave generation by block movements near explosions. In Section 2, we discuss the upper mantle structure of northwestern Eurasia where long period and short period WWSS seismograms from nuclear explosions in the Soviet Union have been incorporated with published apparent velocity data to derive a compressional wave velocity model for the upper mantle beneath northwest Eurasia. The waveforms were modeled using generalized ray theory and a starting model was perturbed by trial and error until a fit was achieved. The seismograms from 9-13 deg exhibit impulsive first arrivals (Pn), implying a smooth, positive velocity gradient between depths of 60 and 150 km. A consistent pulse arriving about 2 seconds after Pn at the ranges 11 to 17 deg is modeled by positioning a low velocity zone between 150 and 200 km. In Section 3, glorified optics has been used to compare the waveform complications caused by two and three dimensional structures. A scheme is developed to synthesize seismic images, in which the direct rays give a preliminary feature of a structure, while the multiple bounds provide further information for improving and refining the model. In Section 4, we consider the problem of reflection and refraction of purely compressional waves incident on an interface separating identical solid half-spaces in which the condition of continuity of shear displacement at the boundary is generalized to one that allows slippage.

The conformal field theory based on the $g/u(1)^d$ coset construction is treated as the WZNW theory for the affine Lie algebra $\\hat g$ with the constrained $\\hat u(1)^d$ subalgebra.Using a modification of the generalized canonical quantization method generators and primary fields of an extended symmetry algebra are found for arbitrary d.

The attenuation of seismic shear waves in the mantle beneath the eastern Australian and Antarctic plates is analysed using a large data set of multiple ScSn waves, reflected n times at the core-mantle boundary and (n-1) times at the surface. The data are the transverse components of deep earthquakes from the subduction zones north and east of Australia, recorded at stations in Antarctica, Australia, Indonesia, New Caledonia and New Zealand. The data are filtered with narrow bandpass filters at five frequencies in the range 0.013-0.040 Hz. The ScSn+1/ScSn amplitude ratios of successive ScS phases are compared to the ratios computed for synthetic seismograms for the same paths and same focal mechanisms, to eliminate the effects of source radiation and geometric attenuation. The synthetic seismograms are computed from a summation of toroidal modes for the 1-D reference model PREM. The observed to computed spectral ratios appear consistent for similar paths. They reveal that the attenuation is not frequency dependent, that the contribution of scattering to attenuation is low, and that the PREM model is a valuable reference model for the study region at the considered frequencies. An inversion of the data at 0.026 Hz is performed to retrieve the quality factor Q in the upper mantle, in regions defined using a priori constraints inferred from seismic shear velocities. Q-values close to those of PREM are found beneath the Australian and Antarctic cratons, lower values beneath the Eastern Australian Phanerozoic margin, and very low values beneath the oceanic region between Australia and Antarctica, where ridges and a triple junction are present. The Australian-Antarctic Discordance along the South-Indian ridge appears as an exception with a Q-value close to those of stable continents. The highest Q-values are found beneath the subduction zones, a feature which is not apparent in global attenuation models possibly because of its narrow lateral extension, and because it extends at depths larger than those sampled by surface waves. Despite limitations due to the uneven distribution of the ScSn bounce points at the surface and to the difficulty of collecting a large number of high quality data, our approach appears very promising. It is complementary to the more widely used determination of seismic attenuation using surface waves because it provides increased depth coverage, and a broader spectral coverage. It therefore has a considerable potential in future investigations of mantle structure and dynamics.

Seismic energy propagating through vertically and laterally varying structures of the earth's crust and lower lithosphere-uppermost mantle is responsible for the numerous and complex seismic phases observed on short-period seismograms at regional distance ranges (100 to 2000 km). Recent advances in techniques for computing synthetic seismograms make it practical to calculate complete seismograms that realistically model many features of regional phases. A modified reflectivity method program is used to interpret some details of record sections of Nevada Test Site (NTS) underground explosions that were observed 700 to 800 km from the sources.

SeisTool is an interactive graphical tool that allows you to analyse seismograms. It runs under the X window environment. The current version employs an OpenLook graphical user interface. It is designed for convenient display of seismograms and handling of events for routine analysis. It also allows phase picking to be done smoothly. A number of time-series analysis operations have also been implemented. Here, is a brief guide to the operation of SeisTool. The intention of this User`s Guide is not to guide you through SeisTool step by step, (The best way of learning how to use SeisTool is run the program and experiment with it.) but, to present a few basic concepts behind SeisTool to acquaint you with the program. The goal of this prototype is to make analysing seismograms as easy and convenient as browsing a file with a text editor. Think of SeisTool as nothing more than a seismogram data file browser.

Large landslides and avalanches generate seismic waves that can be used to detect, locate, and constrain the dynamic processes active in the slides. We have detected and located several landslide events using the Global Seismographic Network (GSN) as a long-period array. The detected events have equivalent long-period magnitudes of about M=5, while local magnitudes for these events, where available, are 2--3 magnitude units smaller. Two of the largest detected landslides are the 2005 Mount Steller (M=5.2) and the 2007 Mount Steele (M=5.2) events, located in the Pacific Coast Range in southern Alaska and the southern Yukon, respectively. In contrast to the forces active in standard earthquakes, in which seismic waves are generated as a consequence of tectonic stress drop within the Earth, landslides excite seismic waves through the time-varying forces caused by the acceleration and deceleration of a sliding mass interacting with the Earth's surface. Both the Mount Steller and the Mount Steele events involved sliding volumes of tens of millions of cubic meters of debris, vertical drops of around 2000 meters and runouts of more than 5 km. We use seismograms from several local and regional seismometers, including records from the STEEP PASSCAL array at epicentral distances as short as 10 km, to model the sliding process. We parameterize the source as a point force acting on the Earth's surface and obtain its magnitude, strike, and dip as a function of time. We observe the initial, nearly vertical, unloading force as the rock detaches from the solid Earth, a downward impulse as the mass is diverted into a horizontal trajectory at the base of the steep mountain slope, and the horizontal force corresponding to the deceleration phase as friction brings the sliding mass to a halt. Both slides have total durations of approximately 100 seconds. We find good agreement between the force histories inferred from seismograms and simple forward calculations of the dynamics of the sliding mass based on local topography, friction, and conservation of momentum.

This paper tests an approach to predict the range of ground motion hazard at specific sites generated by earthquakes on specific faults. The approach is based upon structural, lithological and rheological descriptions of the fault zones, development of fault rupture scenarios, and computation of synthetic seismograms using empirical Green`s functions. Faults are placed within a regional geomechanical model. The approach is based upon three hypothesis: (1) An exact solution of the representation relation that utilizes empirical Green`s functions enables very accurate computation of ground motions generated by a given rupture; (2) a general description of the rupture is sufficient; and (3) the structural, lithological and Theological characteristics of a fault can be used to constrain, in advance, possible future rupture histories. Ground motion hazard here refers to three-component, full wave train descriptions of displacement, velocity, and acceleration over the frequency band 0.01 to 25 Hz. Corollaries to these hypotheses are that the range of possible fault rupture histories is narrow enough to functionally constrain the range of strong ground motion predictions, and that a discreet set of rupture histories is sufficient to span the infinite combinations possible from a given range of rupture parameters.

Part of the challenge in efforts to improve seismic imaging is to develop software to generate computer models of complex geology. One approach uses a triangulation technique designed to support efficient and accurate computation of seismic wavefields for two-dimensional models of the Earth`s interior. This triangulation approach offers the opportunity to perform dynamic ray tracing and create synthetic seismograms based on the method of Gaussian beams. The Gaussian beam method (GBM), well known to overcome limitations of conventional ray tracing, starts to show artifacts in models of significant complexity due to excessive spreading of the beams. One reason for this spreading is an inappropriate choice of complex beam parameter {epsilon}. This is especially serious because, for complex media, the choice of {epsilon} is extremely difficult. In cases with unacceptable beam spreading, the author finds that restricting the range of extrapolation away from the beam support improves the quality of the generated data. Other situations, such as near-critical transmitted rays, may also cause beam spreading; in this case, it is possible to artificially reduce associated artifacts.

We present group velocity dispersion results from a study of regional fundamental mode Rayleigh and Love waves propagating across India and surrounding regions. Data used in this study comes from broadband stations operated in India by us in addition to data from seismograms in the region whose data is archived at the IRIS Data Management Centre. The large amount of new and available data allows an improved path coverage and accordingly increased lateral resolution than in previous similar global and regional studies. 1D path- averaged dispersion measurements have been made using multiple filter analyis for source-receiver paths and are combined to produce tomographic group velocity maps for periods between 10 and 60 s. Preliminary Rayleigh wave group velocity maps have been produced using ~2500 paths and checkerboard tests indicate an average resolution of 5 degrees with substantially higher resolution achieved over the more densely sampled Himalayan regions. Short period velocity maps correlate well with surface geology resolving low velocity regions (2.0-2.4 km/s) corresponding to the Ganges and Brahmaputra river deltas, the Indo-Gangetic plains, the Katawaz Basin in Pakhistan, the Tarim Basin in China and the Turan Depression. The Tibetan Plateau is well defined as a high velocity region (2.9-3.2 km/s) at 10 s period, but for periods greater than 20 s it becomes a low velocity region which remains a distinct feature at 60 s and is consistent with the increased crustal thickness. The southern Indian shield is characterized by high crustal group velocities (3.0-3.4 km/s) and at short periods of 10 and 15 s it is possible to make some distinction between the Singhbhum, Dharwar and Aravali cratons. Initial Love wave group velocity maps from 500 dispersion measurements show similarly low velocities at short periods across regions with high sedimentation but higher velocities compared to Rayleigh waves across the Indian shield.

We propose a method to obtain effective grid parameters for the finite-difference (FD) method with standard Earth models using analytical ways. In spite of the broad use of the heterogeneous FD formulation for seismic waveform modeling, accurate treatment of material discontinuities inside the grid cells has been a serious problem for many years. One possible way to solve this problem is to introduce effective grid elastic moduli and densities (effective parameters) calculated by the volume harmonic averaging of elastic moduli and volume arithmetic averaging of density in grid cells. This scheme enables us to put a material discontinuity into an arbitrary position in the spatial grids. Most of the methods used for synthetic seismogram calculation today receives the blessing of the standard Earth models, such as the PREM, IASP91, SP6, and AK135, represented as functions of normalized radius. For the FD computation of seismic waveform with such models, we first need accurate treatment of material discontinuities in radius. This study provides a numerical scheme for analytical calculations of the effective parameters for an arbitrary spatial grids in radial direction as to these major four standard Earth models making the best use of their functional features. This scheme can analytically obtain the integral volume averages through partial fraction decompositions (PFDs) and integral formulae. We have developed a FORTRAN subroutine to perform the computations, which is opened to utilization in a large variety of FD schemes ranging from 1-D to 3-D, with conventional- and staggered-grids. In the presentation, we show some numerical examples displaying the accuracy of the FD synthetics simulated with the analytical effective parameters.

A new 1D core-shell strategy is demonstrated for a hydrogen-generation photo-electrochemical cell (PEC). This Si/iodine-doped poly(3,4-ethylenedioxythiophene) (PEDOT) 1D nanocable array shows an encouraging solar-to-chemical energy-conversion efficiency. Coating with iodine-doped PEDOT can effectively enhance the photocatalytic efficiency and stability of SiNW arrays. The PEC model proposed shows a potentially promising structure for H(2) production using solar energy. PMID:22961939

The Foulden Maar, located in Central Otago, New Zealand, is a monogenetic volcanic crater filled with lacustrine sediments. It is part of the latest Oligocene - Early Miocene Waipiata Volcanic Field. The geological structure of the Foulden Maar has been characterised using a combination of geophysical techniques. These include seismic reflection surveys, a gravity survey and magnetic surveys. A new technique for interpretion of maar sediments in reflection profiles has also been incorporated, with generation of a synthetic seismogram from a 184 m core. Seismic surveying has revealed a series of high amplitude reflections between 0.15 and 0.3 s that indicate the presence of debris flow deposits below a bowl shaped accumulation of laminites. Lower reflectivity below 0.3 s is probably caused by the stratified part of the diatreme breccia. Two normal fault structures have also been identified along with a series of antiformal reflections at ~1 s depth which are probably related to a sill structure. The synthetic seismogram had six significant amplitude horizons within it and these were tied with the borehole log to give a detailed re-interpretation of one seismic profile. Gravity surveying revealed a -6.1 mGal oblate residual gravity minimum with a diameter of ~1100 m and data from this survey has been modelled in 2D and 3D. Magnetic surveying has enabled the identification of volcanic features around and within the maar structure with short and long wavelength trends observed in data from ground-based and airborne surveys. A series of short wavelength anomalies have high intensities with a maximum of 1730 nT, and are primarily caused by basaltic dykes and flows around the edge of the structure. Two longer wavelength trends have a much lower magnitude with anomalies between 80 and 250 nT, and these are caused by root structures buried at a depth of >1500 m. Overall, the Foulden Maar probably has a structure that is similar to the generalised model proposed by Lorenz (2003) for a hard rock environment.

We provide an algorithm to find a minimal set of generators for the Rees algebra associated to rational space curves of type 1,1,d-2) in projective 3-space based solely on a $mu$-basis of the curve. We also illustrate the geometry behind the generators via a case study of rational quartic space cu...

Although P2rx7 has been proposed as a type 1 diabetes (T1D) susceptibility gene in NOD mice, its potential pathogenic role has not been directly determined. To test this possibility, we generated a new NOD stock deficient in P2X(7) receptors. T1D development was not altered by P2X(7) ablation. Previous studies found CD38 knockout (KO) NOD mice developed accelerated T1D partly because of a loss of CD4(+) invariant NKT (iNKT) cells and Foxp3(+) regulatory T cells (Tregs). These immunoregulatory T cell populations are highly sensitive to NAD-induced cell death activated by ADP ribosyltransferase-2 (ART2)-mediated ADP ribosylation of P2X(7) receptors. Therefore, we asked whether T1D acceleration was suppressed in a double-KO NOD stock lacking both P2X(7) and CD38 by rescuing CD4(+) iNKT cells and Tregs from NAD-induced cell death. We demonstrated that P2X(7) was required for T1D acceleration induced by CD38 deficiency. The CD38 KO-induced defects in homeostasis of CD4(+) iNKT cells and Tregs were corrected by coablation of P2X(7). T1D acceleration in CD38-deficient NOD mice also requires ART2 expression. If increased ADP ribosylation of P2X(7) in CD38-deficient NOD mice underlies disease acceleration, then a comparable T1D incidence should be induced by coablation of both CD38 and ART2, or CD38 and P2X(7). However, a previously established NOD stock deficient in both CD38 and ART2 expression is T1D resistant. This study demonstrated the presence of a T1D resistance gene closely linked to the ablated Cd38 allele in the previously reported NOD stock also lacking ART2, but not in the newly generated CD38/P2X(7) double-KO line. PMID:21357538

In this study, acceleration time histories of the June 27, 1998 Adana-Ceyhan (Turkey) earthquake, are simulated using a stochastic modeling technique for finite faults proposed by Beresnev and Atkinson (1997). The fault length, width and the depth to the top of the fault for the earthquake are assumed 30 km, 21 km and 15 km, respectively, based on the aftershock distribution. Simulations are made for two common site classes: soil and rock. Their response characteristics are obtained from the site-specific amplification functions estimated for the weak motion seismograms at stations located in the region using spectral ratio methods. The results show that the overall agreement between simulated and observed waveforms and spectra is quite satisfying. However, significant discrepancies exist at certain stations, implying that site amplification functions play an important role in the simulation process. The effects of nonlinearity and basin edge generated surface waves do not clearly dominate on the results. The peak horizontal acceleration contours estimated using the calibrated model are consistent with the observed intensity values and the other evidences of strong ground motions.

By reanalyzing Apollo lunar seismograms using array-processing methods, a recent study suggests that the Moon has a solid inner core and a fluid outer core, much like the Earth. The volume fraction of the lunar inner core is 38%, compared with 4% for the Earth. The pressure at the Moon's core-mantle boundary is 4.8 GPa, and that at the ICB is 5.2 GPa. The partially molten state of the lunar core provides constraints on the thermal and chemical states of the Moon: The temperature at the inner core boundary (ICB) corresponds to the liquidus of the outer core composition, and the mass fraction of the solid core allows us to infer the bulk composition of the core from an estimated thermal profile. Moreover, knowledge on the extent of core solidification can be used to evaluate the role of chemical convection in the origin of early lunar core dynamo. Sulfur is considered an antifreeze component in the lunar core. Here we investigate the melting behavior of the Fe-S system at the pressure conditions of the lunar core, using the multi-anvil apparatus and synchrotron and laboratory-based analytical methods. Our goal is to understand compositionally driven convection in the lunar core and assess its role in generating an internal magnetic field in the early history of the Moon.

Using a 3-D finite difference method with a rotated-staggered-grid (RSG) scheme we generated synthetic seismograms for a reservoir model consisting of three horizontal layers with the middle layer containing parallel, equally spaced fractures. By separating and analyzing the backscattered signals in the FK domain, we can obtain an estimate of the fracture spacing. The fracture spacing is estimated by taking one-half of the reciprocal of the dominant wavenumber of the backscattered energy in data acquired normal to the fractures. FK analysis for fracture spacing estimation was successfully applied to these model results, with particular focus on PS converted waves. The method was then tested on data from the Emilio Field. The estimated fracture spacing from the dominant wavenumber values in time windows at and below the reservoir level is 25-40m. A second approach for fracture spacing estimation is based on the observation that interference of forward and backscattered energy from fractures introduces notches in the frequency spectra of the scattered wavefield for data acquired normal to the fracture strike. The frequency of these notches is related to the spacing of the fractures. This Spectral Notch Method was also applied to the Emilio data, with the resulting range of fracture spacing estimates being 25-50m throughout the field. The dominant spacing fracture spacing estimate is about 30-40 m, which is very similar to the estimates obtained from the FK method.

The rapid detection and characterization of megathrust earthquakes is a difficult task given their large rupture zone and duration. These events produce very strong ground vibrations in the near field that can cause weak motion instruments to clip, and they are also capable of generating large-scale tsunamis. The 2011 M 9 Tohoku-oki earthquake that occurred offshore Japan is one member of a series of great earthquakes for which extended geophysical observations are available. Here, we test an automated scanning algorithm for great earthquakes using continuous very long-period (100-200 s) seismic records from K-NET strong-motion seismograms of the earthquake. By continuously performing the cross-correlation of data and Green's functions (GFs) in a moment tensor analysis, we show that the algorithm automatically detects, locates and determines source parameters including the moment magnitude and mechanism of the great Tohoku-oki earthquake within 8 min of its origin time. The method does not saturate. We also show that quasi-finite-source GFs, which take into account the effects of a finite-source, in a single-point source moment tensor algorithm better fit the data, especially in the near-field. We show that this technique allows the correct characterization of the earthquake using a limited number of stations. This can yield information usable for tsunami early warning.

We examine data used to construct coda magnitude in southern California to estimate the spatial variation of coda Q and its dependence on frequency. Our analysis combined with independent borehole data (Abercrombie, 1995) suggests coda is mainly generated by multiple scattering in the upper few km of the crust where large impedance contrasts occur due to surface layering or fracturing. The ubiquitous observation that coda Q increases with frequency is explained as arising from multiple reverberations in the upper crust. We suggest that the telegraph model that has been successfully used to describe reflection seismogram multiples in the exploration industry may also apply to earthquakes. Under this model the apparent increase of Q with frequency is due to trapping of high frequency energy in the upper crust. This behavior is expected if the associated reflector series has an exponential autocorrelation function, a feature of the telegraph model. At lower frequencies trapping is less efficient. The combined effects give rise to an apparent absorption band that we suppose is superimposed on frequency-independent intrinsic attenuation. Maximum apparent attenuation occurs at wavelengths equal to the dimensions of the regions of upper crust that contain the scattering layers. At lower frequencies trapping is less effective and attenuation decreases as the longer wavelength waves sample the deeper crust and upper mantle where, due to over-burden pressures, acoustic impedance contrasts are less extreme.

We have previously developed an antibiotic-free system for the selection of plant transformants that is based on a gene (OASA1D) for a mutant ? subunit of rice anthranilate synthase. The product of this gene shows a reduced sensitivity to negative feedback regulation by tryptophan. Whereas 5-methyltryptophan (5MT) is lethal for normal plant cells because it causes tryptophan deficiency, expression of OASA1D confers resistance to this tryptophan analog. We used this OASA1D-5MT system for the transformation of Arabidopsis thaliana. An expression vector containing OASA1D under the control of the 35S promoter of cauliflower mosaic virus was introduced into Arabidopsis by Agrobacterium-mediated transformation. Transgenic plants that harbored OASA1D exhibited resistance to 5MT but did not manifest any other differences in growth, morphology, or fertility. The OASA1D-5MT selection system performed as well as the HPT-hygromycin system for the transformation of Arabidopsis. Given the limited number of conventional marker genes currently available, OASA1D should prove to be a useful tool in Arabidopsis transformation, especially for the generation of plants carrying multiple transgenes.   

We develop a general method for constructing curved traversable wormholes in (2+1)-dimensional spacetime, by generating surfaces of revolution around smooth curves. Application of this method to a straight line gives the usual spherically symmetric wormholes. The physics behind (2+1)-d curved traversable wormholes is discussed based on solutions to the Einstein field equations when the tidal force is zero. The Einstein field equations are found to reduce to one equation whereby the mass-energy density varies linearly with the Ricci scalar, which signifies that our (2+1)-d curved traversable wormholes are supported by dust of ordinary and exotic matter without radial tension nor lateral pressure. With this, two examples of (2+1)-d curved traversable wormholes: the helical wormhole and the catenary wormhole, are constructed and we show that there exist geodesics through them supported by non-exotic matter. This general method is applicable to our (3+1)-d spacetime.

The Source Scanning Algorithm (SSA) has been introduced and developed by Hann Kao, Shao-Ju Shan and co-workers since 2004. The basic idea of SSA is simple: Seismograms in a station network can be stacked, using theoretical arrival times in a given (e.g. 3D) structural model and an assumed point source. A set of trial source positions is grid searched, and the most likely positions are those producing the largest correlation (so-called brightness). The method may work fully automatically without any manual or automatic phase picking. It can be used for events with unclear arrivals; as such it is a powerful tool to locate tremors, including their continuous monitoring. Source complexity (multiple events) can be studied and perhaps even the causative fault planes can be identified. Nevertheless, many questions related to the application of the method remain still open. Some of them are as follows: (i) Is the method competitive in comparison with standard location methods of individual events whose phase arrivals are clear? (ii) How accurate must be the structural model in which the theoretical arrival times are calculated? (iii) How to combine data from local and near regional seismic stations? We report preliminary results from a small project designed to critically re-evaluate possibilities and limitations of the SSA method. Our analysis is focused on the Efpalio 2010, Mw~5 earthquake, Corinth Gulf, Greece (Sokos et al., in press), which we previously located by a number of different methods. We use the same source-station configuration as in the real case, but invert synthetic seismograms, calculated for a 1-sec and 0.2-sec source pulse by the discrete-wavenumber method in 1D crustal models. Theoretical travel times are calculated by the ray method, including head waves from all model discontinuities (intra-crustal ones and Moho). Both the double-couple and isotropic sources are considered. We demonstrate the Lat-Lon brightness maps for varying trial source depths, and discuss when and how the retrieved source position is biased, or even the single source is erroneously imaged as a multiple. Artifacts are explained in terms of factors, such as the duration of the considered P-wave group, the frequency content and complexity of the crustal model. We show that in models with only few constant-velocity layers (as routinely used in many location codes) problems arise because the first prominent P-wave groups, whose maximum amplitudes determine the brightness, are modeled by the superposition of the head waves, reflected waves and the direct P wave. We demonstrate a possible use of the initial P-wave group of a very short duration, more suitable for a formal interpretation in terms of the fastest first-arriving wave. Modifications of the method using smooth velocity variation in the crust are discussed because of real crust, in which clear intra-crustal discontinuities might be rare or not well known. Improvements in the depth resolution through a combined P- and S-wave brightness are also presented.

Summary The comparison of seismograms plays a central role in seismology in diverse ways such as relative time-shifts, propagation effects between stations for a common source, and inversion for source or structural studies. Different measures for comparison have been used in the various situations, but all can be linked by the use of the concept of a transfer operator between a reference seismogram and a comparator trace. Transfer operators are implicit in various methods of phase velocity estimation, receiver functions and anisotropy studies, and measures for estimating arrival times and amplitude variations. Such transfer operators have a number of important roles; first they allow a visual assessment of the similarities of seismograms, secondly they provide a useful description of prop...

Computation of Receiver Functions from observed seismograms involves the process of deconvolution which is highly sensitive to the presence of noise. Earthquake waveforms are non-stationary signals that contain colored Gaussian noise. The frequency content of the noise generally overlaps with the frequency content of the original signal and hence it is not possible to simply frequency filter the Gaussian noise. Techniques like the use of optimum filters are not suitable for seismic signals as seismic signals are non-stationary. Previous attempts to improve the signal-to-noise ratio in Receiver Functions involved stacking at the expense of path averaging of the crustal structure. Here we demonstrate that denoising of the seismic signal using the wavelet transform to sparsely represent the data, thresholding the amplitude and reconstructing the signal from remaining coefficients leads to a significant improvement in the signal to noise ratio. Hence it is useful in stabilizing the deconvolution process used to compute Receiver Functions. We have conducted tests on synthetic seismograms by adding different percentages of noise and trying to retrieve the original signal from the noisy traces. Cross-correlation coefficients between the denoised signal and the synthetic trace have been observed to improve over the cross-correlation coefficients between the noisy signal and the synthetic trace. It has been shown that this method of denoising seismograms does not introduce any noticeable distortions in the original signal [Galiana-Merino et al, 2003]. Receiver Function computed from the denoised seismograms showed a better correlation with the Receiver Function computed from synthetic seismograms than the Receiver Function computed from noisy seismograms. The signal-to-noise ratio was observed to have improved significantly. The improved stability of deconvolution due to denoising aided a more robust estimation of Receiver Functions from the retrieved signals. We show that this technique works well on real data without introducing any noticeable artifacts into the data and thus leads to a better Receiver Function estimation.

A hybrid method, coupling a ray tracing method and a finite difference approach, is proposed for modelling T-wave propagation from an underwater source to an on-land seismic station. The long-range hydroacoustic wavefield, estimated in the SOFAR channel by the Maslov approach, shows many triplications of propagation with an increasing number of caustics as the range increases. Ray tracing approaches lead to a straightforward analysis of the SOFAR propagation: we find that the duration and the amplitude of the hydroacoustic T waves generated by a source close to the SOFAR axis may be respectively eight times longer and almost seven times higher than the duration and the amplitude of hydroacoustic T waves generated by a source close to the SOFAR limits. The finite difference modelling handles the complex hydroacoustic-seismi c T-wave conversion on atoll shores with an illustration of seismic T waves recorded during the Midplate experiment in 1989. Two different seismic stations, FGA on the Fangataufa Atoll and DIN on the Mururoa Atoll, both in French Polynesia, have recorded the seismic T waves due to an underwater chemical blast at a distance greater than 900 km. Synthetic seismograms computed by our proposed hybrid method are close enough to the real data for quantitative interpretation. We believe that the input model structure is accurate enough to allow such analysis of the seismic T waves. The numerical simulation shows that the seismic T waves recorded at both stations are mainly composed of P phases and Rayleigh phases. The simulation shows that the seismic T-wave duration is often linked to the source depth, although other factors (the continental slope or the distance between the top of the continental slope and the seismic station) may also affect the signal duration.

In 1995, Best et al. published a formula for the exact bit error probability for Viterbi decoding of the rate R=1/2, memory m=1 (2-state) convolutional encoder with generator matrix G(D)=(1 1+D) when used to communicate over the binary symmetric channel. Their formula was later extended to the rate ...

Decade long research in 1D nanowire field effect transistors (FET) shows although it has ultra-low off-state leakage current and a single device uses a very small area, its drive current generation per device is extremely low. Thus it requires arrays of nanowires to be integrated together to achieve...

We consider ordinary (non penalized) least-squares regression where the regression function is chosen in a randomly generated sub-space GP \\subset S of finite dimension P, where S is a function space of infinite dimension, e.g. L2([0, 1]^d). GP is defined as the span of P random features that are li...

Laser-Supported Detonation (LSD), one type of Laser-Supported Plasma (LSP), is considered as the most important phenomena because it can generate high pressure and high temperature for laser absorption. In this study, I have numerically simulated the 1-D LSD waves propagating through a helium gas, in which Multiply-charged ionization model is considered for describing an accurate ionization process.

Natural-gas hydrates have been encountered beneath the permafrost and considered a drilling hazard by the oil and gas industry for years. Drilling engineers working in Russia, Canada and the USA have documented numerous problems, including drilling kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates as a potential energy source agree that the resource potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained from physical samples taken from actual hydrate-bearing rocks. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The project team drilled and continuously cored the Hot Ice No. 1 well on Anadarko-leased acreage beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and used for determining physical characteristics of hydrates and surrounding rock. After the well was logged, a 3D vertical seismic profile (VSP) was recorded to calibrate the shallow geologic section with seismic data and to investigate techniques to better resolve lateral subsurface variations of potential hydrate-bearing strata. Paulsson Geophysical Services, Inc. deployed their 80 level 3C clamped borehole seismic receiver array in the wellbore to record samples every 25 ft. Seismic vibrators were successively positioned at 1185 different surface positions in a circular pattern around the wellbore. This technique generated a 3D image of the subsurface. Correlations were generated of these seismic data with cores, logging, and other well data. Unfortunately, the Hot Ice No. 1 well did not encounter hydrates in the reservoir sands, although brine-saturated sands containing minor amounts of methane were encountered within the hydrate stability zone (HSZ). Synthetic seismograms created from well log data were in agreement with reflectivity data measured by the 3D VSP survey. Modeled synthetic seismograms indicated a detectable seismic response would be expected in the presence of hydrate-bearing sands. Such a response was detected in the 3D VSP data at locations up-dip to the west of the Hot Ice No. 1 wellbore. Results of this project suggest that the presence of hydrate-bearing strata may not be related as simply to HSZ thickness as previously thought. Geological complications of reservoir facies distribution within fluvial-deltaic environments will require sophisticated detection technologies to assess the locations of recoverable volumes of methane contained in hydrates. High-resolution surface seismic data and more rigorous well log data analysis offer the best near-term potential. The hydrate resource potential is huge, but better tools are needed to accurately assess their location, distribution and economic recoverability.

We propose a new quantitative determination of shear wave velocities for distinct geological units in the Bohemian Massif, Czech Republic (Central Europe). The phase velocities of fundamental Love wave modes are measured along two long profiles (~200 km) crossing three major geological units and one rift-like structure of the studied region. We have developed a modified version of the classical multiple filtering technique for the frequency-time analysis and we apply it to two-station phase velocity estimation. Tests of both the analysis and inversion are provided. Seismograms of three Aegean Sea earthquakes are analyzed. One of the two profiles is further divided into four shorter sub-profiles. The long profiles yield smooth dispersion curves; while the curves of the sub-profiles have complicated shapes. Dispersion curve undulations are interpreted as period-dependent apparent velocity anomalies caused both by different backazimuths of surface wave propagation and by surface wave mode coupling. An appropriate backazimuth of propagation is found for each period, and the dispersion curves are corrected for this true propagation direction. Both the curves for the long and short profiles are inverted for a 1D shear wave velocity model of the crust. Subsurface shear wave velocities are found to be around 2.9 km/s for all four studied sub-profiles. Two of the profiles crossing the older Moldanubian and Teplá-Barrandian units are characterized by higher velocities of 3.8 km/s in the upper crust while for the Saxothuringian unit we find the velocity slightly lower, around 3.6 km/s at the same depths. We obtain an indication of a shear wave low velocity zone above Moho in the Moldanubian and Teplá-Barrandian units. The area of the Eger Rift (Teplá-Barrandian-Saxothuringian unit contact) is significantly different from all other three units. Low upper crust velocities suggest sedimentary and volcanic filling of the rift as well as fluid activity causing the earthquake swarms. Higher velocities in the lower crust together with weak or even missing Moho implies the upper mantle updoming.

I compute short-period, high-resolution surface-wave slowness maps for central Asia using Bayesian tomography. I focus on the region between 69 and 108 degrees east and 29 and 54 degrees north and used seismograms from more than 1100 events. Using multiple-filter and phase-matched filter techniques, I measured the dispersion characteristics of the signals between 6 and 30 seconds period. These Rayleigh-wave group velocity dispersion curves were used to compute high-resolution, half-degree cell size, slowness tomographic maps. Because short periods are primarily sensitive to upper crustal structures, the images display low velocities associated with the Tarim, Junggar, and Qaidam basins. Relatively high velocities are associated with mountainous tectonic features such as the Tian Shan. I validated these maps using dispersion curves from 640 events that were not used to construct the tomographic model. The model predictions show a significant variance reduction at short and intermediate periods (6 to 15 s) with respect to the prior model. My model also shows 15% improvement in surface-wave detection capability with respect to previous 1D models. These high-resolution, short-period tomography maps can help improve regional magnitude estimations for construction of m b : Ms discriminants. Moreover, the short-period surface-wave tomographic results show unprecedented resolution that reveals greater geologic detail than has previously been achieved using surface waves, and which give us insight into the shear-velocity structure of the crust underlying this part of Asia. I also validate an alternative method to the traditional m b - Ms seismic discriminant. This new technique uses a probability of detection model (PXD) to estimate the probability that a surface wave detection came from an underground explosion. I measured noise and signal levels of over 1,300 earthquakes and 26 underground explosions recorded at the broadband, digital station WMQ in western China. The PXD analysis shows a reduction of the false alarm rate from 22% to 17% for this dataset. Using path-dependent attenuation and the previously computed group velocity values, the false alarm rate decreases even more to 15%. I also present a new procedure to accurately make Rayleigh wave amplitude measurements and I compute new surface wave magnitudes, Ms, following the methodology of Marshall and Basham and the methodology of Russell. The new Ms computed following Russel?s formulation proved to be an effective mb - M s discriminant and do not require farther analysis with the probability of detection model. This finding is of great importance to seismologists working on seismic discrimination problems. To end, I implement and apply a method to jointly invert surface-wave group velocities and free-air gravity observations. (Abstract shortened by UMI.)

For developing laser propulsion, it is very important to analyze the mechanism of Laser-Supported Detonation (LSD), because it can generate high pressure and high temperature to be used by laser propulsion can be categorized as one type of hypersonic reacting flows, where exothermicity is supplied not by chemical reaction but by radiation absorption. I have numerically simulated the 1-D and Quasi-1-D LSD waves propagating through an inert gas, which absorbs CO2 gasdynamic laser, using a 2-temperature model. Calculated results show the fundamental properties of the non-equilibrium LSD Waves.

The Source Physics Experiment (SPE) will involve a series of explosions in various geologic and emplacement conditions to validate numerical simulation methods to predict behavior of seismic wave excitation and propagation for nuclear test monitoring. The first SPE's currently underway involve explosions in the Climax Stock (granitic geology) at the Nevada National Security Site (NNSS). Detailed geologic data and published material properties for the major lithologic units of the NNSS and surrounding region were used to build three-dimensional models for seismic wave propagation simulations. The geologic structure near the SPE shot point is quite varied including granitic, carbonate, tuff and alluvium lithologies. We performed preliminary ground motion simulations for a near-source domain covering 8 km x 8 km at the surface centered on the shot point to investigate various source and propagation effects using WPP, LLNL's anelastic seismic wave finite difference code. Simulations indicate that variations in wave propagation properties of the sub-surface will generate strongly path-dependent response once the energy has left the relatively small granitic geology of the near-surface Climax Stock near the SPE shot point. Rough topography to the north and west of SPE shot point causes additional complexity in the signals including energy on the transverse components. Waves propagate much faster through the granitic and carbonate formations and slower through the tuff and alluvium. Synthetic seismograms for a pure explosion source in a 3D geologic structure show large amplitudes on transverse component. For paths to the south sampling the granite, tuff and alluvium lithologies transverse component amplitudes are as high as 50% of that on the vertical and radial components.

Seismic refraction profiles recorded along the eastern Snake River Plain (ESRP) in southeastern Idaho during the 1978 Yellowstone-Snake River Plain cooperative seismic profiling experiment are interpreted to infer the crustal velocity and attenuation (Q-1) structure of the ESRP. Travel-time and synthetic seismogram modeling of a 250 km reversed refraction profile as well as a 100 km detailed profile indicate that the crust of the ESRP is highly anomalous. Approximately 3 to 6 km of volcanic rocks (with some interbedded sediments) overlie an upper-crustal layer (compressional velocity approx. =6.1 km/s) which thins southwestward along the ESRP from a thickness of 10 km near Island Park Caldera to 2 to 3 km beneath the central and southwestern portions of the ESRP. An intermediate-velocity (approx. =6.5 km/s) layer extends from approx. =10 to approx. =20 km depth. a thick (approx. =22 km) lower crust of compressional velocity 6.8 km/s, a total crustall thickness of approx. =42 km, and a P/sub n/ velocity of approx. =7.9 km/s is observed in the ESRP, similar to the western Snake River Plain and the Rocky Mountains Provinces. High attenuation is evident on the amplitude corrected seismic data due to low-Q values in the volcanic rocks (Q/sub p/ = 20 to 200) and throughout the crust (Q/sub p/ = 160 to 300). Based on these characteristics of the crustal structure and volcanic-age progression data, it is suggested that the ESRP has resulted from an intensitive period of intrusion of mantle-derived basaltic magma into the upper crust generating explosive silicic volcanism and associated regional uplift and caldera collapse. This activity began about 15 m.y. ago in southwestern Idaho and has migrated northeast to its present position at Yellowstone. Subsequent cooling of the intruded upper crust results in the 6.5 km/s velocity intermediate layer. Crustal subsidence and periodic basaltic volcanism as represented by the ESRP complete the sequence of crustal evolution.

The objective of this project was to investigate seismic wave scattering effects, and to assess the existence and impact of mild nonlinear contributions to the attenuation of seismic signals, for purposes of monitoring underground nuclear explosions. The authors developed an efficient propagation algorithm, and applied it to the problems of understanding conversion of regional phases, coherence of waveforms measured by seismic arrays, and the accuracy of direct versus scattered phases. Experiments related to mild nonlinear attenuation were also reviewed. This final report consists of preprints of three papers which will be submitted for open publication. In the first paper, the accuracy and efficiency of the phase screen method for elastic waves are assessed by comparing with finite difference calculations of elastic wave propagation in 2-D random media. The phase screen method is a forward propagation algorithm which depends only on local S and P wave velocities. Both methods are used to generate synthetic seismograms for a suite of 2-D random media characterized by exponential and von Karman (self-similar) autocorrelation functions of varying strength and correlation length. In the second paper, phase screen simulations of vector wave propagation in elastic random media are applied to two studies relevant to monitoring underground nuclear explosions. Simulated coherence functions for vector waves are compared to analytic and simulated results also assume the Rytov approximation. In the third paper, experiments which reflect the attenuation of propagating pulses in salt in the moderate strain regime of .001 to .000001, corresponding roughly to ranges of 100 to 10,000 meters from an explosion with yield of 1-kt, are reviewed.

The seismic structure of North Africa is poorly understood due to the relative paucity of stations and seismicity when compared to other continental regions of the world. A better understanding of the velocity structure in this area will allow improved models of travel times and regional phase amplitudes. Such models will improve location and identification capability in this region leading to more effective monitoring of the Comprehensive Nuclear-Test-Ban Treaty. Using regional-to-teleseismic Rayleigh and Love waves that traverse the area we can obtain information about the region's seismic structure by examining phase velocity as a function of period. We utilize earthquakes from the tectonically active regions bounding North Africa (Mediterranean, Red Sea, East African Rift, and Mid-Atlantic Ridge) recorded at broadband seismic stations distributed throughout the region. A two-station method is utilized to determine phase velocity information along the interstation segment of the ray path. The two-station method provides particular advantage in this region as it dramatically increases the number of events available to provide pure North African sampling. Bandpass filters are applied to the seismograms so that peaks and troughs may be correlated. The phase is unwrapped and a difference curve computed. The difference curve is then converted to a phase velocity dispersion curve. Phase velocity curves are constructed in the range of 10 to 120 seconds. Rayleigh and Love waves in this period range are most sensitive to the shear velocity structure of the lithosphere and can be used in combination with additional independent seismic observations (e.g. Pn tomography, surface wave group velocity tomography, receiver functions, etc.) to construct reliable velocity models. We compare velocities computed in this study to those generated from well known models for similar tectonic regions throughout the world in order to better define the tectonic setting of North Africa. Results from this study help constrain the regional tectonics of the area and will also be used to better define the seismic characteristics required to verify the CTBT.

Steam generator level measurement is important factor for plant transient analyses using best estimate thermal hydraulic computer codes since the value of steam generator level is used for steam generator level control system and plant protection system. Because steam generator is in the saturation condition which includes steam and liquid together and is the place that heat exchange occurs from primary side to secondary side, computer codes are hard to calculate steam generator level realistically without appropriate level measurement model. In this paper, we prepare the steam generator models using RETRAN-3D that include geometry models, full range feedwater control system and five types of steam generator level measurement model. Five types of steam generator level measurement model consist of level measurement model using elevation difference in downcomer, 1D level measurement model using fluid mass, 1D level measurement model using fluid volume, 2D level measurement model using power and fluid mass, and 2D level measurement model using power and fluid volume. And we perform the evaluation of the capability of each steam generator level measurement model by simulating the real plant transient condition, the title is 'Reactor Trip by The Failure of The Deaerator Level Control Card of Ulchin Unit 3'. The comparison results between real plant data and RETRAN-3D analyses for each steam generator level measurement model show that 2D level measurement model using power and fluid mass or fluid volume has more realistic prediction capability compared with other level measurement models. (authors)

In this study, forward seismic modelling of four geological models with Hydrocarbon (HC) traps were performed by ray tracing method to produce synthetic seismogram of each model. The idea is to identify the Hydrocarbon Indicators (HCI?s) such as bright spot, flat spot, dim spot and Bottom Simulating...

A method is explained to derive automatically the compressional and the shear-wave velocity from micro seismograms in boreholes. Examples of a vsub(p)-, vsub(s)- and vsub(p)/vsub(s)-log are shown. The determination of the attenuation for compressional waves is discussed.

We apply the Automated Multimode Inversion of surface and S-wave forms to a large global data set, verify the accuracy of the method and assumptions behind it, and compute an Sv-velocity model of the upper mantle (crust–660 km). The model is constrained with ~51 000 seismograms recorded at 368 perma...

One-dimensional (1D) correlated electron systems are good targets for the exploration of photoinduced phase transitions (PIPTs). This is because photocarrier generations and/or charge transfer (CT) excitations by lights can stimulate instabilities inherent to the 1D nature of electronic states through strong electron–electron interactions and electron(spin)–lattice interactions. In this paper, we review the ultrafast dynamics of three typical PIPTs observed in 1D correlated electron systems: 1) a photoinduced transition from a Mott insulator to a metal in a halogen-bridged Ni-chain compound, [Ni(chxn)2Br]Br2 (chxn = cyclohexanediamine); 2) a photoinduced melting of a spin-Peierls phase in an organic CT compound, K-tetracyanoquinodimethane (TCNQ); 3) a photoinduced transition between neutral (N) and ionic (I) states in an organic CT compound, tetrathiafulvalene-p-chloranil (TTF-CA). The primary dynamics of these PIPTs are discussed on the basis of the results of femtosecond pump–probe spectroscopy.   

Brain glucose supplies most of the carbon required for acetyl-coenzyme A (acetyl-CoA) generation (an important step for myelin synthesis) and for neurotransmitter production via further metabolism of acetyl-CoA in the tricarboxylic acid (TCA) cycle. However, it is not known whether reduced brain glucose transporter type I (GLUT-1) activity, the hallmark of the GLUT-1 deficiency (G1D) syndrome, leads to acetyl-CoA, TCA or neurotransmitter depletion. This question is relevant because, in its most common form in man, G1D is associated with cerebral hypomyelination (manifested as microcephaly) and epilepsy, suggestive of acetyl-CoA depletion and neurotransmitter dysfunction, respectively. Yet, brain metabolism in G1D remains underexplored both theoretically and experimentally, partly because c...

Abstract Shape defining hard templates containing arrays of aligned cylindrical nanopores have been exploited as a powerful tool in the synthesis of tubular and solid, rod like one dimensional (1D) nanostructures consisting of inorganic and polymeric materials. Gaining control over the mesoscopic fine structure in the 1D nanostructures thus obtained has remained challenging. However, it is easy to conceive that their properties largely depend on internal features characterized by mesoscopic length scales. The self assembly of block copolymers inside nanopores with hard confining pore walls can be exploited to rationally generate 1D nanostructures with internal self assembled mesoscopic fine structures. These self assembled mesoscopic fine structures can be converted to mesopores, into whic...

During the severe accident, the deposition of the aerosol and gas from the released fission product on the inside of RCS is an important research field in terms of the evaluation of source terms. But the ISP- 46 results showed that the current severe accident codes based on the lumped model over-predicted ({approx}40%) the amount of fission product deposited on the steam generator U-tube by the thermo-phoresis phenomena compared with that (17%) of measured. In order to improve the current model deficiency, 1-D model has been developed considering the distribution of temperature and velocity within the boundary layer near the wall surface. The amount of deposit mass was predicted with this 1-D model. From the calculation results, the 1-D model predicts the amount of FP deposition by the thermo-phoresis phenomena closer than the lumped model does. Also this model can contribute to improve the MELCOR code using the lumped type thermophoresis model.

We develop a general method for constructing curved traversable wormholes in (2+1)-dimensional spacetime, by generating surfaces of revolution around smooth curves. Application of this method to a straight line gives the usual spherically symmetric wormholes. The physics behind (2+1)-d curved traversable wormholes is discussed based on solutions to the Einstein field equations when the tidal force is zero. The Einstein field equations are found to reduce to one equation whereby the mass-energy density varies linearly with the Ricci scalar, which signifies that our (2+1)-d curved traversable wormholes are supported by dust of ordinary and exotic matter without radial tension nor lateral pressure. With this, two examples of (2+1)-d curved traversable wormholes: the helical wormhole and the c...

This report presents the results of the development of a one-dimensional radionuclide transport code, MMT2D (Multicomponent Mass Transport), for the AEGIS Program. Multicomponent Mass Transport is a numerical solution technique that uses the discrete-parcel-random-wald (DPRW) method to directly simulate the migration of radionuclides. MMT1D accounts for: convection;dispersion; sorption-desorption; first-order radioactive decay; and n-membered radioactive decay chains. Comparisons between MMT1D and an analytical solution for a similar problem show that: MMT1D agrees very closely with the analytical solution; MMT1D has no cumulative numerical dispersion like that associated with solution techniques such as finite differences and finite elements; for current AEGIS applications, relatively few parcels are required to produce adequate results; and the power of MMT1D is the flexibility of the code in being able to handle complex problems for which analytical solution cannot be obtained. Multicomponent Mass Transport (MMT1D) codes were developed at Pacific Northwest Laboratory to predict the movement of radiocontaminants in the saturated and unsaturated sediments of the Hanford Site. All MMT models require ground-water flow patterns that have been previously generated by a hydrologic model. This report documents the computer code and operating procedures of a third generation of the MMT series: the MMT differs from previous versions by simulating the mass transport processes in systems with radionuclide decay chains. Although MMT is a one-dimensional code, the user is referred to the documentation of the theoretical and numerical procedures of the three-dimensional MMT-DPRW code for discussion of expediency, verification, and error-sensitivity analysis.

Shoot apical meristems (SAMs) of seed plants are small groups of pluripotent cells responsible for making leaves, stems and flowers. While the primary SAM forms during embryogenesis, new SAMs, called axillary SAMs, develop later on the body of the plant and give rise to branches. In Arabidopsis plants, axillary SAMs develop in close association with the adaxial leaf base at the junction of the leaf and stem (the leaf axil). We describe the phenotype caused by the Arabidopsis phabulosa-1d (phb-1d) mutation. phb-1d is a dominant mutation that causes altered leaf polarity such that adaxial characters develop in place of abaxial leaf characters. The adaxialized leaves fail to develop leaf blades. This supports a recently proposed model in which the juxtaposition of ad- and abaxial cell fates is required for blade outgrowth. In addition to the alteration in leaf polarity, phb-1d mutants develop ectopic SAMs on the undersides of their leaves. Also, the phb-1d mutation weakly suppresses the shoot meristemless (stm) mutant phenotype. These observations indicate an important role for adaxial cell fate in promoting the development of axiallary SAMs and suggest a cyclical model for shoot development: SAMs make leaves which in turn are responsible for generating new SAMs. PMID:9655815

The New Zealand Earthquake of February 21, 2011, Mw 6.1 occurred in the South Island, New Zealand with the epicenter at longitude 172.70°E and latitude 43.58°S, and with depth of 5 km. The Mw 6.1 earthquake occurred on an unknown blind fault involving oblique-thrust faulting, which is 9 km away from southern of the Christchurch, the third largest city of New Zealand, with a striking direction from east toward west (United State Geology Survey, USGS, 2011). The earthquake killed at least 163 people and caused a lot of construction damages in Christchurch city. The Peak Ground Acceleration (PGA) observed at station Heathcote Valley Primary School (HVSC), which is 1 km away from the epicenter, is up to almost 2.0g. The ground-motion observation suggests that the buried earthquake source generates much higher near-fault ground motion. In this study, we have analyzed the earthquake source spectral parameters based on the strong motion observations, and estimated the near-fault ground motion based on the Brune's circular fault model. The results indicate that the larger ground motion may be caused by a higher dynamic stress drop,??d , or effect stress drop named by Brune, in the major source rupture region. In addition, a dynamical composite source model (DCSM) has been developed to simulate the near-fault strong ground motion with associated fault rupture properties from the kinematic point of view. For comparison purpose, we also conducted the broadband ground motion predictions for the station of HVSC; the synthetic seismogram of time histories produced for this station has good agreement with the observations in the waveforms, peak values and frequency contents, which clearly indicate that the higher dynamic stress drop during the fault rupture may play an important role to the anomalous ground-motion amplification. The preliminary simulated result illustrated in at Station HVSC is that the synthetics seismograms have a realistic appearance in the waveform and time duration to the observations, especially for the vertical component. Synthetics Fourier spectra are reasonably similar to the recordings. The simulated PGA values of vertical and S26W components are consistent with the recorded, and for the S64E component, the PGA derived from our simulation is smaller than that from observation. The resultant Fourier spectra both for the synthetic and observation is much similar with each other for three components of acceleration time histories, except for the vertical component, where the derived spectra from synthetic data is smaller than that resultant from observation when the frequency is above 10 Hz. Both theoretical study and numerical simulation indicate that, for the 2011 Mw 6.1, New Zealand Earthquake, the higher dynamic stress drop during the source rupture process could play an important role to the anomalous ground-motion amplification beside to the other site-related seismic effects. The composite source modeling based on the simple Brune's pulse model could approximately provide us a good insight into earthquake source related rupture processes for a moderate-sized earthquake.

Random quasi-phase-matched frequency doubling of fs pulses to the deep UV was obtained in 1D nonlinear photonic crystal (NPC) of strontium tetraborate. Tuning range of generated radiation is from 187.5 to 215 nm. The spectrum of generated radiation consists from series of peaks with the width of order of 1 Å. These peaks are the manifestation of the NPC band structure. Using fs oscillator as the fundamental radiation source, maximum average power of generated radiation is of order 1 ?W, the enhancement factor with respect to monodomain sample being of order of several hundred. The red rotational shift of NPC band structure is experimentally demonstrated.

Daphnia magna were exposed under semistatic conditions (i.e., conditions taking natural degradation into account) to a pesticide mixture consisting of a pyrethroid insecticide (cyfluthrin) and a pre-emergent herbicide (diuron) as well as pesticides individually using a full life cycle exposure (21 days). Subsequently, offspring from the second reproductive brood were used to continue exposure for a second generation. Survival, time to first brood, total number of offspring produced, number of broods produced, growth rate, and population growth rate were recorded for each generation and concentration. Significant differences existed between F0 and F1 D. magna for survival, in which F1 were less sensitive to pesticide mixtures than F0. In addition, F1 D. magna were significantly smaller than...

A three-dimensional, variably-saturated flow and multicomponent biogeochemical reactive transport model of uranium bioremediation was used to generate synthetic data . The 3-D model was based on a field experiment at the U.S. Dept. of Energy Rifle Integrated Field Research Challenge site that used acetate biostimulation of indigenous metal reducing bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. A key assumption in past modeling studies at this site was that a comprehensive reaction network could be developed largely through one-dimensional modeling. Sensitivity analyses and parameter estimation were completed for a 1-D reactive transport model abstracted from the 3-D model to test this assumption, to identify parameters with the greatest potential to contribute to model predictive uncertainty, and to evaluate model structure and data limitations. Results showed that sensitivities of key biogeochemical concentrations varied in space and time, that model nonlinearities and/or parameter interactions have a significant impact on calculated sensitivities, and that the complexity of the model's representation of processes affecting Fe(II) in the system may make it difficult to correctly attribute observed Fe(II) behavior to modeled processes. Non-uniformity of the 3-D simulated groundwater flux and averaging of the 3-D synthetic data for use as calibration targets in the 1-D modeling resulted in systematic errors in the 1-D model parameter estimates and outputs. This occurred despite using the same reaction network for 1-D modeling as used in the data-generating 3-D model. Predictive uncertainty of the 1-D model appeared to be significantly underestimated by linear parameter uncertainty estimates.

We study the thermalization process of charm quarks in hot and dense matter. The diffusion of heavy quarks is calculated via a Langevin equation, both for a static medium as well as a QGP medium generated by a (3+1)D hydrodynamic model. We define two criteria for the thermalization of the heavy quarks, and observe thermalization times that are longer than the lifetime of the QGP phase for reasonable values of the diffusion constant.

We present a new approach of beam homogenizing elements based on a statistical array of concave cylindrical microlens arrays. Those elements are used to diffuse light in only one direction and can be employed together with fly's eye condensers to generate a uniform flat top line for high power coherent light sources. Conception, fabrication and characterization for such 1D diffusers are presented in this paper. PMID:20588560

A perturbation method for computing quick estimates of the echo decay in pulsed spin echo gradient NMR diffusion experiments in the short gradient pulse limit is presented. The perturbation basis involves (relatively few) dipole distributions on the boundaries generating a small perturbation matrix in O(s^2) time, where s denotes the number of boundary elements. Several approximate eigenvalues and eigenfunctions to the diffusion operator are retrieved. The method is applied to 1-D and 2-D systems with Neumann boundary conditions.

For many years there has been a rich accumulation of geologic investigations in the Three Gorges Reservoir (TGR) region of the Yangtze River that provided useful information to hydro-power generation, engineering construction, flood control and geohazard mitigation. However, there has not yet been a complete knowledge base on the TGR region's deep lithospheric structure, whose relationship with seismicity is still largely unknown. The successful completion of the main dam and full water impoundment of the 660-kilometer-long reservoir makes the safety and geohazard mitigation a top concern for the TGR and the entire central China region. To address such concern, we are conducting a study of the lithospheric structure and seismotectonics of the TGR region by mapping the 3D crust-mantle seismic velocity structure of Huangling anticline in the core TGR region. Since 2007 we have been collecting and analyzing seismic and gravity data of the TGR region, and conducting passive surveys of local and teleseismic earthquakes using a mobile array of 60 RefTek125A (TEXAN) seismographs. Our field tests indicate that the records from the TEXAN's are compatible with the records of permanent stations for teleseismic events. Using 5-Hz geophones, the TEXAN recorded reliable first break waveforms of events that are located 2000 km away. The data that we have recorded so far include dozens of small events in the TGR region as well as more than 100 aftershocks of the devastating 2008/05/12 WenChuan earthquake located about 450-600 km from the TGR region. Preliminary analysis of the array seismograms indicated good data quality for M2.5 or greater events that are located more than 60 km away from the stations and for M4.0 or greater events more than 400 km away. The quality and quantity of the data allow us to generate shot profiles from the WenChuan aftershocks and local events in the TGR region. We will present details of the data, analysis process, and preliminary results on the crust-mantle seismic structure and its relations with major faults, seismicity, and near-surface geohazards in the TGR region.

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.

The antibiotic L-155,175, a potent antiparasitic and antifungal compound, has an unusual structure involving 16-membered macrolides that contain a tetrahydropyran ring connected through a three-carbon linker chain. To identify the biosynthetic gene cluster for L-155,175, a genomic DNA library of Streptomyces hygroscopicus ATCC31955 was constructed and screened with a degenerate primer set designed from a conserved region of the ketosynthase (KS) domain. Sequence analysis of a fosmid clone, pEY1D8 (34 kb), revealed multiple open reading frames (ORFs) encoding type I polyketide synthase (PKS). To determine whether the cloned genes are involved in L-155,175 biosynthesis, a deletion mutant (1D8m) was generated by homologous recombination, in which the gene encoding the KS domain was substituted with an apramycin-resistance gene by PCR-targeted Streptomyces gene replacement. LC-MS analysis showed that L-155,175 production was completely abolished in the 1D8m strain, thereby proving that the cloned gene is responsible for L-155,175 biosynthesis. The sequencing of two other fosmid clones (pEY8B10 and pEY1C9) harboring overlapping sequences from pEY1D8 revealed a 60-kb DNA segment encoding six ORFs for type I PKS harboring 12 modules. The domain organization of the PKS modules encoded by PKS exactly matched the structure of L-155,175. This is the first report on the gene cluster involved in the biosynthesis of L-155,175. PMID:22669556

In this paper an MHD generator obtained by two separate channels (G1, G2) is considered. The outlet section of the first channel is connected with the inlet section of the second one by a transition region (D). Each channel has its own saddle shaped magnet. A distribution of the magnetic field on the axis of the channels with different peak values can be produced, and different gas flow conditions for the two channels can be established. The performance of the two channels system is compared with that of a single channel (G0) with a single saddle shaped magnet. A quasi-one-dimensional code (MHD1D) is utilised for the channel design and an integral code (SADDLE) is utilised for the saddle shaped magnet design. Both the MHD1D and the SADDLE codes are based on a design optimization procedure. The design problem of the MHD channel and of the saddle shaped magnet are formulated as non linear, constrained optimization problems which are solved by means of a sequential quadratic programming algorithm. Different solutions for the two channels system are studied. For each solution the mass flow rate through the two channels generator is equal to that of the generator G0. Firstly by means of the codes NMD1D and SADDLE, the design of G1 is performed. By these calculations the stagnation parameters at the inlet section of generator G2 are known, and the design of G2 is done. The generator parameters (electrical power output, compression power, heat losses) and the magnet parameters (superconductor volume, stored energy) are compared with those of the generator G0. A parametric analysis is done in order to find the best configuration for channels G1 and G2. A discussion of the results is presented.

Summary We present a new, S-velocity model of the European upper mantle, constrained by inversions of seismic waveforms from broad-band stations in Europe and surrounding regions. We collected seismograms for the years 1990-2007 from all permanent stations in Europe for which data were available. In addition, we incorporated data from temporary experiments. Automated multimode inversion of surface and S-wave forms was applied to extract structural information from the seismograms, in the form of linear equations with uncorrelated uncertainties. The equations were then solved for seismic velocity perturbations in the crust and mantle with respect to a 3-D reference model with a realistic crust. We present two versions of the model: one for the entire European upper mantle and another, with ...

Self-affine properties have been observed in a large variety of rough profiles and time series from natural data sets. In this work, seismograms used for oil prospecting, which contain information of distinct subsurface features collected by seismic waves reflected or scattered at their interfaces, are taken into consideration. It is expected that any self-affine property, measured by the Hurst exponent H, depends on the depth. For each seismic trace, H is evaluated locally within a moving window, which is chosen narrow enough to reveal space dependency but also wide enough to display scale invariance. With the use of color code diagrams, it is possible to draw two-dimensional diagrams that show the local dependence of H for the analyzed seismogram. The reliability of the method is tested ...

In this paper we present two new procedures for automatic detection and picking of P-wave arrivals. The first involves the application of kurtosis and skewness on the vector magnitude of three component seismograms. Customarily, P-wave arrival detection techniques use vertical component seismogram which is appropriate only for teleseismic events. The inherent weakness of those methods stems from the fact that the energy from P-wave is distributed among horizontal and vertical recording channels. Our procedure, however, uses the vector magnitude which accommodates all components. The results show that this procedure would be useful for detecting/picking of P-arrivals from local and regional earthquakes and man-made explosions. The second procedure introduces a new method called "Ratios in Higher Order Statistics (RHOS)." Unlike commonly used techniques that involve derivatives, this technique employs ratios of adjacent kurtosis and skewness values to improve the accuracy of the detection of the P onset. RHOS c...

In this paper, we report that the ratio of broadband energy (0.01?2 Hz) to high-frequency energy (0.3?2 Hz), E r, estimated from regional seismograms of India, might be a useful parameter in estimating tsunami potential of earthquakes in the Sumatra?Andaman region. E r is expected to be sensitive to the depth as well as to the source characteristics of an earthquake. Since a shallow and slow earthquake has a greater tsunamigenic potential, E r may be a useful diagnostic parameter. We base our analysis on broadband seismograms of the great earthquakes of Sumatra?Andaman (2004, M w ~ 9.2) and Nias (2005, M w 8.6), 41 of their aftershocks, and the earthquakes of north Sumatra (2010, M w 7.8) and Nicobar (2010, M w 7.4) recorded at VISK, a station located on the east coast of India. In the ana...

Extremely high formation fluid pressures and temperatures produced a number of drilling problems and added expense to a recent SE Asia well. Multiple mechanisms have generated the overpressure and control its distribution. 1-D analysis and basin models could not explain the extreme fluid pressures at the crest of the structure drilled. 2-D analysis more accurately modelled the processes involved. Integrating 2-D models with seismic velocity and well log analysis yields the following: (1) Disequilibrium compaction is important throughout the section; (2) Gas generation or chemical compaction contribute to the extreme pressures at the base of the section; (3) Dipping sandstones redistribute overpressure at the base of the section. (author)

The separation of earthquake source signature and propagation effects (Green's function) that encode a seismogram is a challenging problem in seismology. The task of separating these two effects is called blind deconvolution. By considering records of multiple earthquakes at a given station, that share the same Green's function, we can write the linear relationship in the time domain uk(t) ? sj(t) - uj(t) ? sk(t) = 0 where uk is the seismogram for the kth source and sj is the jth unknown source. The symbol ? represents the convolution operator. From two or more seismograms, we obtain a homogeneous linear system where the unknowns are the sources. This system is subject to a scaling constraint to deliver a non-trivial solution and can be solved using the method of Lagrange multipliers, commonly used to tackle optimization under constraints. A number of issues require careful consideration for this problem to be resolved. First, source durations are not known a priori and must be determined. If the source duration is too short, the system becomes over-determined, and if it is too long, the system becomes under-determined. To deal with this problem, we augment our system by introducing the sources durations as unknowns and we solve the combined system (sources and source durations as unknowns) using separation of variables (Golub & Pereyra, 1973). Our solution is derived using the direct inversion to recover the sources and Newton's method to recover source durations. Second, to resolve realistic signals requires solution vectors of dimension ? 104, hence matrix inversion methods have been employed in conjunction with fast matrix multiplication operators based on the Fast Fourier Transform (FFT). This method has been tested using synthetic seismograms created by convolution of random sources with a simplified Green's function and signal to noise levels up to 10% with encouraging results.

Correlation detectors are becoming a standard method for identifying seismic signals from repeating sources. These highly sensitive, source-specific detectors frequently facilitate a reduction in the detection threshold by around an order of magnitude. Detections are typically declared when the value of the correlation coefficient (CC), or a related statistic, exceeds significantly some measure of the variability of values over a longer time window. The performance of correlation detectors is often compromised by the presence of short duration, high-amplitude signals, which influence excessively the value of the CC. We suggest replacing the original seismograms with waveforms in which the value of each sample is replaced by the ratio of that value to a centred moving average of absolute values of the original waveform. These ratio-to-moving-average (RMA) seismograms are relatively featureless over long time intervals, but resemble greatly the original waveforms over short time windows and hence still capture the characteristic seismic fingerprint of a given source. We demonstrate a correlation detection calculation, which fails due to the presence of a high-amplitude signal interfering with part of the correlation window, but which succeeds when RMA seismograms are used due to the diminished influence of the interfering signal. We also demonstrate an example from an aftershock sequence where the CC traces are heavily modulated due to the high dynamic range of the original waveforms. This makes the setting of detection thresholds difficult and results in multiple peaks, which do not correspond to events in the vicinity of the master event. Repeating the calculation using RMA seismograms results in CC traces with a more well-defined detection threshold and most of the spurious detections are lost. The ability to set lower detection thresholds without increasing greatly the number of false alarms facilitates the robust detection of lower magnitude events.

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

We present a novel approach to full waveform tomography based on misfits in the time-frequency domain and adjoint methods. Our focus is on theoretical developments and synthetic inversions for heterogeneities in the Australian upper mantle. The centrepieces of our methodology are envelope and instantaneous phase misfits defined on time-frequency transforms of the seismograms. These misfits allow us to extract the maximum robust information from seismograms for the purpose of high-resolution tomography. We derive Fréchet kernels for different definitions of the envelope and phase misfits using adjoint methods. The Fréchet kernels for instantaneous phase measurements agree with those obtained from waveform cross- correlation only in the special - though unrealistic - case of monochromatic waves. Examples of Fréchet kernels for data collected during the SKIPPY project are computed by means of a recently developed spectral element method. With synthetic inversions we demonstrate that lateral heterogeneities can be determined efficiently by using instantaneous phase measurements of S waves and surface wave trains without explicitly dissecting the seismograms. Special attention is given to the following questions relating to the inversion, i.e., the misfit minimisation algorithm: 1) determination of the optimal step length for gradient methods, 2) acceptance/rejection criteria for the updated models and 3) the pre-conditioning of the steepest descent direction. Finally, we examine the possibility of using enevelope or amplitude measurements and their corresponding Fréchet kernels for seismic waveform tomography.

We determine the source parameters for 2003 (Mw 6.5) Bam, Iran, earthquake using an empirical Green’s function summation approach to model ground motions recorded by two strong motion stations at approximately 45 km epicentral distance. We introduce a genetic algorithm technique to optimize the fit to observed elastic response spectra. The proposed genetic algorithm technique allows us to explore the sensitivity of the results to multiple source parameters, including hypocenter location, focal mechanism (Strike and Dip), P-wave velocity in depth, fault dimension and rupture and healing velocities. We simulated the three components of seismogram at a far station, Mohammad-Abad station, by means of an inversion solution technique and predicted seismograms at another far station, Abaragh, incorporating the estimated model parameters. More agreement of our synthesized seismograms with those of the observed data in comparison with the results of other investigators confirms the reliability of estimated seismological parameters and the applicability of our technique. A series of sensitivity analysis are performed for demonstrating the influence of individual model parameter variation on defined error value. Using the empirical Green’s function summation method, our inferred source parameters provide the basis for predicting main shock shaking and guiding retrofitting efforts at sites, for example, the historical buildings in Arge-Bam site which were damaged during the 2003 Bam earthquake and strong motion data is unavailable.

Bimodal nuclear thermal rocket systems have been shown to reduce the weight and cost of space vehicles to Mars and beyond by utilizing the reactor for power generation in the relatively long duration between burns in an interplanetary trajectory. No information, however, is available regarding engine and reactor-level operation of such bimodal systems. The purpose of this project is to generate engine and reactor models with sufficient fidelity and flexibility to accurately study the component-level effects of operating a propulsion-designed reactor at power generation levels. Previous development of a 1-D reactor and tie tube model found that ignoring heat generation inside of the tie tube leads to under-prediction of the temperature change and over-prediction of pressure change across the tie tube. This paper will present the development and results of a tie tube model that has been extended to account for heat generation, specifically in the moderator layer. This model is based on a 1-D distribution of power in the fuel elements and tie tubes, as a precursor to an eventual neutron-driven reactor model.

Single-photon excitation spectra from the lowest singlet (1)D(2) level of sulfur atoms were recorded with a tunable vacuum ultraviolet (VUV) radiation source generated by frequency tripling in noble gases. The photolysis of CS(2) at 193 nm was used to produce the singlet S((1)D(2)) sulfur atoms that were then excited to neutral superexcited states with the tunable VUV radiation. These superexcited states undergo autoionization into the first ionization continuum state of S(+)((4)S(3/2) (o))+e(-), which is not directly accessible from the S((1)D(2)) state via an allowed transition. The excitation spectra were recorded by monitoring the S(+) signal in a velocity imaging apparatus while scanning the VUV excitation wavelength. Three new lines were observed in the spectra which have not been previously reported. The full widths at half maximum (FWHM) of each of the observed transitions were determined by fitting the profiles of each absorption resonances with the Fano formula. Autoionization lifetimes tau of these singlet superexcited states were obtained from FWHM using the Uncertainty Principle. Abnormal autoionization lifetimes were found for the 3s(2)3p(3)((2)D(o))nd((1)D(2)) and the 3s(2)3p(3)((2)D(o))ns((1)D(2)) Rydberg series, in which tau(5d) and tau(7s) are shorter than tau(4d) and tau(6s), respectively. This is contrary to the well-known scaling law of tau(n*) proportional, variantn(*3), which should be followed within a series unless there exist perturbations from other series or new channels open up to which some members of the series can decay. Possible perturbations from the nearby triplet series are suspected for causing the broadening of the 5d and 7s levels. PMID:15847536

The failure of brittle materials, for example glasses and rock masses, is commonly observed to be discontinuous. It is, however, difficult to simulate these phenomena by use of conventional numerical simulation methods, for example the finite difference method or the finite element method, because of the presence of computational grids or elements artificially introduced before the simulation. It is, therefore, important for research on such discontinuous failures in science and engineering to analyze the phenomena seamlessly. This study deals with the coupled simulation of elastic wave propagation and failure phenomena by use of a moving particle semi-implicit (MPS) method. It is simple to model the objects of analysis because no grid or lattice structure is necessary. In addition, lack of a grid or lattice structure makes it simple to simulate large deformations and failure phenomena at the same time. We first compare analytical and MPS solutions by use of Lamb's problem with different offset distances, material properties, and source frequencies. Our results show that analytical and numerical seismograms are in good agreement with each other for 20 particles in a minimum wavelength. Finally, we focus our attention on the Hopkinson effect as an example of failure induced by elastic wave propagation. In the application of the MPS, the algorithm is basically the same as in the previous calculation except for the introduction of a failure criterion. The failure criterion applied in this study is that particle connectivity must be disconnected when the distance between the particles exceeds a failure threshold. We applied the developed algorithm to a suspended specimen that was modeled as a long bar consisting of thousands of particles. A compressional wave in the bar is generated by an abrupt pressure change on one edge. The compressional wave propagates along the interior of the specimen and is visualized clearly. At the other end of the bar, the spalling of the bar is reproduced numerically, and a broken piece of the bar is formed and falls away from the main body of the bar. Consequently, these results show that the MPS method effectively reproduces wave propagation and failure phenomena at the same time.

Many geophysical studies rely on finding and analysing particular topographic features: the various landforms associated with glaciation, for example, or those that characterise regional tectonics. Typically, these can readily be identified from visual inspection of datasets, but this is a tedious and time-consuming process. However, the development of techniques to perform this assessment automatically is often difficult, since a mathematical description of the feature of interest is required. To identify characteristics of a feature, such as its spatial extent, each characteristic must also have a mathematical description. Where features exhibit significant natural variations, or where their signature in data is marred by noise, performance of conventional algorithms may be poor. One potential avenue lies in the use of neural networks, or other learning algorithms, ideal for complex pattern recognition tasks. Rather than formulating a description of the feature, the user simply provides the algorithm with a training set of hand-classified examples: the problem then becomes one of assessing whether some new example shares the characteristics of this training data. In seismology, this approach is being developed for the identification of high-quality seismic waveforms amidst noisy datasets (e.g. Valentine & Woodhouse, 2010; Valentine & Trampert, in review): can it also be applied to topographic data? To explore this, we attempt to identify the locations of seamounts from gridded bathymetric data (e.g. Smith & Sandwell, 1997). Our approach involves assessing small 'patches' of ocean floor to determine whether they might plausibly contain a seamount, and if so, its location. Since seamounts have been extensively studied, this problem provides an ideal testing ground: in particular, various catalogues exist, compiled using 'traditional' approaches (e.g. Kim & Wessel, 2011). This allows us to straightforwardly generate training datasets, and compare algorithmic performance. In future, we hope to extend the approach to identifying the seamount's 'footprint' and, by isolating it from the underlying seafloor, extracting parameters of interest such as height, radius and volume. Kim, S.-S. & Wessel, P., 2011. New global seamount census from altimetry-derived gravity data, Geophysical Journal International, 186, pp.615-631. Smith, W., and Sandwell, D., 1997. Global seafloor topography from satellite altimetry and ship depth soundings, Science, 277, pp.1957-1962. Valentine, A. & Trampert, J., in review. Data-space reduction, quality assessment and searching of seismograms: Autoencoder networks for waveform data. Valentine, A. & Woodhouse, J., 2010. Approaches to automated data selection for global seismic tomography, Geophysical Journal International, 102, pp.1001-1012.

This work presents an optical up-conversion system with frequency quadrupling for wavelength-division-multiplexing (WDM) communication systems using a dual-parallel Mach-Zehnder modulator without optical filtering. Four-channel 1.25-Gb/s wired fiber-to-the-x (FTTx) and wireless radio-over-fiber (RoF) signals are generated and transmitted simultaneously. Moreover, the decline in receiver sensitivities due to Mach-Zehnder modulator bias drifts is also investigated. Receiver power penalties of the 20-GHz up-converted WDM signals and baseband (BB) FTTx signals are less than 1 dB when bias deviation voltage is less the 20% of the half-wave voltage. After transmission over a 50-km SSMF, the receiver power penalties of both the BB and 20-GHz RF OOK signals are less than 1 dB. Notably, 60-GHz optical up-conversion can be achieved using 15-GHz radio frequency (RF) components and equipment. PMID:19189002

We have performed L-shell spectroscopy and one-dimensional (1-D) imaging of a line focus plasma from a laser-heated Fe polished slab using the tabletop COMET laser system at the Lawrence Livermore National Laboratory. These plasmas are used to generate a Ne-like Fe transient gain x-ray laser that is recorded simultaneously. A spherically-curved crystal spectrometer gives high resolution x-ray spectra of the n = 3-2 and n = 4-2 resonance lines with 1-D spatial resolution along the line focus. Spectra are presented for different laser pulse conditions. In addition, a variety of x-ray imaging techniques are described. We discuss imaging results from a double-slit x-ray camera with a spherically-curved crystal spectrometer. We show a high resolution Fe K-{alpha} spectrum from the x-ray laser target that indicates the presence of hot electrons in the x-ray laser plasma.

We investigate the optical properties of one-dimensional (1D) dimerized Mott insulators using the 1D dimerized extended Hubbard model. Numerical calculations and a perturbative analysis from the decoupled-dimer limit clarify that there are three relevant classes of charge-transfer (CT) states generated by photoexcitation: interdimer CT unbound states, interdimer CT exciton states, and intradimer CT exciton states. This classification is applied to understanding the optical properties of an organic molecular material, 1,3,5-trithia-2,4,6-triazapentalenyl (TTTA), which is known for its photoinduced transition from the dimerized spin-singlet phase to the regular paramagnetic phase. We conclude that the lowest photoexcited state of TTTA is the interdimer CT exciton state and the second lowest state is the intradimer CT exciton state.   

Abstract Both the Goddard Profiling Algorithm (GPROF) and European Centre for Medium-Range Weather Forecasts (ECMWF) one-dimensional + four-dimensional variational analysis (1D+4D-Var) rainfall retrievals are inversion algorithms based on Bayes' theorem. Differences stem primarily from the a priori information. The GPROF uses an observationally generated a priori database whereas ECMWF 1D-Var uses the model forecast first guess (FG) fields. The relative similarity in the two approaches means that comparisons can shed light on the differences that are produced by the a priori information. Case studies have found that differences can be classified into four categories based upon the agreement in the brightness temperatures (Tbs) and in the microphysical properties of cloud water path (CWP) a...

The paper contains the short description of the design process of the axial flow turbines for Small Hydro. The crucial elements of the process are: ARDES programme for 1D inverse problem (containing the statistic information of the well performed hydraulic units, applying the lifting aerofoil theory); determination of universal hill diagram and optimization of the runner blades geometry by utilization of the 3D CFD codes. As the result of design process with utilization of both design steps, the generated runner blades geometry (1D inverse problem) and some computational results of 3D CFD solver have been presented. As the conclusion some crucial remarks of the designed process have been brought forward.

Two new Co(II) complexes, [Co2(H2O)(Bipy)2(Bript)2] n (I) and [Co(H2O)(Phen)(Bript)] ? H2O (II), where H2Bript = 4-bromoisophthalic acid, Bipy = 2,2?-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co2+ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ??? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investig...

Impacts of climatic change on agriculture and adaptation are of key concern of scientific research. However, vast uncertainties exist among global climates model output, emission scenarios, scale transformation and crop model parameterization. In order to reduce these uncertainties, we integrate output results of four IPCC emission scenarios of A1FI, A2, B1 and B2, and five global climatic patterns of HadCM3, PCM, CGCM2, CSIRO2 and ECHAM4 in this study. Based on 20 databases of future climatic change scenarios from the Climatic Research Unit (CRU), the scenario data of the climatic daily median values are generated on research sites with the global mean temperature increase of 1 °C (GMT+1D), 2 °C(GMT+2D) and 3 (GMT+3D). The impact of CO2 fertilization effect on wheat biomass for GMT+1D, ...

Observations of molecular clouds show the existence of starless, dense cores, threaded by magnetic fields. Observed line widths indicate these dense condensates to be embedded in a supersonically turbulent environment. Under these conditions, the generation of magnetic waves is inevitable. In this paper, we study the structure and support of a 1D plane-parallel, self-gravitating slab, as a monochromatic, circularly polarized Alfven wave is injected in its central plane. Dimensional analysis shows that the solution must depend on three dimensionless parameters. To study the nonlinear, turbulent evolution of such a slab, we use 1D high resolution numerical simulations. For a parameter range inspired by molecular cloud observations, we find the following. 1) A single source of energy injection is sufficient to force persistent supersonic turbulence over several hydrostatic scale heights. 2) The time averaged spatial extension of the slab is comparable to the extension of the stationary, analytical WKB solution. ...

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)

The Method of Nearby Problems (MNP), a form of defect correction, is examined as a method for generating exact solutions to partial differential equations and as a discretization error estimator. For generating exact solutions, four-dimensional spline fitting procedures were developed and implemented into a MATLAB code for generating spline fits on structured domains with arbitrary levels of continuity between spline zones. For discretization error estimation, MNP/defect correction only requires a single additional numerical solution on the same grid (as compared to Richardson extrapolation which requires additional numerical solutions on systematically-refined grids). When used for error estimation, it was found that continuity between spline zones was not required. A number of cases were examined including 1D and 2D Burgers equation, the 2D compressible Euler equations, and the 2D incompressible Navier-Stokes equations. The discretization error estimation results compared favorably to Richardson extrapolation and had the advantage of only requiring a single grid to be generated.

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

The accuracy of diffusion reactor codes strongly depends on the quality of the groups constants processing. For many years, the generation of such constants was based on 1-D infinity cell transport calculations. Some developments using collision probability or the method of characteristics allow, nowadays, 2-D assembly group constants calculations. However, these 1-D and 2-D codes how some limitations as , for example, on complex geometries and in the neighborhood of heavy absorbers. On the other hand, since Monte Carlos (MC) codes provide accurate neutro flux distributions, the possibility of using these solutions to provide group constants to full-core reactor diffusion simulators has been recently investigated, especially for the cases in which the geometry and reactor types are beyond the capability of the conventional deterministic lattice codes. The two greatest difficulties on the use of MC codes to group constant generation are the computational costs and the methodological incompatibility between analog MC particle transport simulation and deterministic transport methods based in several approximations. The SERPENT code is a 3-D continuous energy MC transport code with built-in burnup capability that was specially optimized to generate these group constants. In this work, we present the preliminary results of using the SERPENT MC code to generate 3-D two-group diffusion constants for a PWR like assembly. These constants were used in the CITATION diffusion code to investigate the effects of the MC group constants determination on the neutron multiplication factor diffusion estimate. (author)

Analytical solutions to the heat transport equation in porous media have been developed in the past to estimate surface water-groundwater interactions. These solutions, however, are based upon simplifying assumptions that are frequently violated in natural systems. A nonvertical flow field, inherent to most field settings, can violate the one-dimensional (1-D) flow assumption and lead to erroneous velocity estimates. In this study, we have developed a 2-D heat and mass transport finite element-based numerical model for a stream aquifer cross section experiencing flow-through. Synthetic multilevel streambed temperature time series were generated with the model using a sinusoidal temperature boundary. The temperature data was used to quantify the vertical flow velocity with a 1-D analytical solution based on the amplitude decay and phase shift of temperature with depth. Results demonstrate that erroneous vertical components of fluid velocity can be obtained by the 1-D analytical solution when the true vertical velocity approaches zero and the flow regime becomes almost horizontal. The results also illustrate that the amplitude ratio method performs quite poorly on the gaining side of the stream where the only reliable method is phase shift. On the losing side of the stream, both methods can be employed but a better estimation is obtained from the amplitude ratio method. In general, amplitude ratio and phase shift data should be used in conjunction to maximize the information of the system.

A series of four tripodal phosphine oxide ligands, (OPR(2))(2)CHCH(2)POR(2) (1a-1d), and four mixed phosphine-phosphine oxide ligands, (OPR(2))(2)CHCH(2)PR(2) (3a-3d), were synthesized and coordinated to yttrium to produce Y(NO(3))(3)[(OPR(2))(2)CHCH(2)POR(2)] (2a-2d) and Y(NO(3))(3)[(OPR(2))(2)CHCH(2)PR(2)](OPPh(3)) (4a-4d) complexes. The previously reported ligand 1a and unknown phosphine oxide ligands 1b-1d were generated in an unprecedented trisubstitution reaction of bromoacetaldehyde diethyl acetal, while the novel partially reduced ligands 3a-3d were synthesized from 1a-1d according to a known literature protocol for the selective monoreduction of bisphosphine oxides. The neutral yttrium complexes 2a-2d are nine-coordinate and display a tricapped trigonal-prismatic geometry. Complexes 4a-4d are also neutral, nine-coordinate species and have a pendant phosphine functionality, which provides the potential to form bimetallic early-late transition-metal complexes. Additionally, yttrium complexes 2a-2d were activated with base and tested for the ring-opening polymerization of ?-caprolactone, but the results showed that base by itself was significantly more effective than the yttrium species investigated. PMID:22909295

The authors consider the steady-state transport of normally incident pencil beams of radiation in slabs of material. A method has been developed for determining the exact radial moments of 3-D beams of radiation as a function of depth into the slab, by solving systems of 1-D transport equations. They implement these radial moment equations in the ONEBFP discrete ordinates code and simulate energy-dependent, coupled electron-photon beams using CEPXS-generated cross sections. Modified P{sub N} synthetic acceleration is employed to speed up the iterative convergence of the 1-D charged particle calculations. For high-energy photon beams, a hybrid Monte Carlo/discrete ordinates method is examined. They demonstrate the efficiency of the calculations and make comparisons with 3-D Monte Carlo calculations. Thus, by solving 1-D transport equations, they obtain realistic multidimensional information concerning the broadening of electron-photon beams. This information is relevant to fields such as industrial radiography, medical imaging, radiation oncology, particle accelerators, and lasers.

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...

We report detailed angle-dependent studies of the microwave (f=50 to 90 GHz) interlayer magneto-electrodynamics of a single crystal sample of the organic charge-density-wave (CDW) conductor alpha-(BEDT-TTF)2KHg(SCN)4. Recently developed instrumentation enables both magnetic field (B) sweeps for a fixed sample orientation and, for the first time, angle sweeps at fixed f/B. We observe series' of resonant absorptions which we attribute to periodic orbit resonances (POR) - a phenomenon closely related to cyclotron resonance. The angle dependence of the POR indicate that they are associated with the low temperature quasi-one-dimensional (Q1D) Fermi surface (FS) of the title compound; indeed, all of the resonance peaks collapse beautifully onto a single set of f/B versus angle curves, generated using a semiclassical magneto-transport theory for a single Q1D FS. We show that Q1D POR measurements provide one of the most direct methods for determining the Fermi velocity, without any detailed assumptions concerning the...

Decade long research in 1D nanowire field effect transistors (FET) shows although it has ultra-low off-state leakage current and a single device uses a very small area, its drive current generation per device is extremely low. Thus it requires arrays of nanowires to be integrated together to achieve appreciable amount of current necessary for high performance computation causing an area penalty and compromised functionality. Here we show that a FET with a nanotube architecture and core-shell gate stacks is capable of achieving the desirable leakage characteristics of the nanowire FET while generating a much larger drive current with area efficiency. The core-shell gate stacks of silicon nanotube FETs tighten the electrostatic control and enable volume inversion mode operation leading to improved short channel behavior and enhanced performance. Our comparative study is based on semi-classical transport models with quantum confinement effects which offers new opportunity for future generation high performance computation.

This paper presents a sequential heuristic procedure (SHP) for the 1D cutting stock problem with pattern reduction, where a set of items are cut from stock bars of the same length to minimize the bar cost, with a secondary objective being to reduce the pattern count of the cutting plan. The SHP generates the current pattern to produce some items, and continues until all items are fulfilled. The algorithm uses two candidate sets (C-Sets). The first is the set of the candidate items for generating the current pattern. The second is the set of candidate patterns from which the current pattern is selected. The algorithm generates candidate patterns using the candidate items, determines the estimated cutting-plan cost (ECP-cost) of each pattern using a look-ahead strategy, and selects the patte...

Reactive ion etching (RIE) using a CH{sub 4}-H{sub 2} plasma is investigated for the fabrication of a GaN one-dimensional (1D) photonic crystal (PhC) slab. The dominant control parameter for the etch rate and the sidewall profile is the dc bias. The influence of operating pressure, CH{sub 4}/H{sub 2} ratio, and total gas flow rate on the etching characteristics is also presented. An etch rate as high as 85 nm/min and an overcut angle as low as 5 degree sign obtained in this work are among the best values reported for conventional RIE technique. The CH{sub 4}-H{sub 2} process is used to etch 1D PhCs with a lattice parameter ranging from 700 to 350 nm and an air filling factor of 0.30 into a 600-nm-thick GaN/sapphire slab. Sharp peaks corresponding to the resonant modes of the nanopatterned structures are observed in the experimental reflection spectra for all the lattice periods. Furthermore, the good optical quality of the nanostructures is evidenced by a resonantly enhanced second-harmonic generation experiment around 400 nm. A second-harmonic generation enhancement factor as high as 10{sup 5} is obtained, compared with the unpatterned GaN reference slab. These results demonstrate that the CH{sub 4}-H{sub 2} conventional RIE technique is well adapted to the etching of GaN PhC for the fabrication of next generation photonic devices exploiting nonlinear processes.

The assumption that Young's modulus is strain-rate invariant is tested for 6061-T6 aluminium alloy and 1018 steel over 10 decades of strain-rate. For the same billets of material, 3 quasi-static strain-rates are investigated with foil strain gauges at room temperature. The ultrasonic sound speeds are measured and used to calculate the moduli at approximately 104 s-1. Finally, 1D plate impact is used to generate an elastic pre-cursor in the alloys at a strain-rate of approximately 106 s1 from which the longitudinal sound speed may be obtained. It is found that indeed the Young's modulus is strain-rate independent within the experimental accuracy.

The neutral exopolysaccharide produced by Lactobacillus delbrueckii ssp. bulgaricus LBB.B332 in skimmed milk was found to be composed of d-glucose, d-galactose, and l-rhamnose in a molar ratio of 1:2:2. Linkage analysis and 1D/2D NMR (1H and 13C) studies carried out on the native polysaccharide as well as on an oligosaccharide generated by a periodate oxidation protocol, showed the polysaccharide to consist of linear pentasaccharide repeating units with the following structure: -->3-alpha-D-Glcp-(1-->3)-alpha-D-Galp-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-L-Rhap-(1-->2)-alpha-D-Galp-(1-->. PMID:17936738

The title coordination polymer, [Cd(NH2NHCSNH2)(HS)2]n·nH2O, has been obtained by self-assembling from the reaction of a methanol/water (volume ratio, 1/1) solution containing cadmium chloride with equivalent amount of succinic acid and thiosemicarbazide. The X-ray crystal analysis reveals that the cadmium atoms are bridged by HS? ligands and mutual sulfur atoms which contribute to formation of the infinite one-dimensional (1D) inorganic–organic chain in a zig-zag way. The second harmonic generation (SHG) response of the complex is much stronger than that of urea.   

The governing equations taken from the assumption of local equilibrium and the heat transfer rate form of Onsager flux have been compared with those based on classical heat transfer formulation by a simplified one dimensional (1-D) thermoelectric generator (TEG) model. In this paper, the simulation of coupled multi-physics effects in a TEG is realized in a three dimensional (3-D) way, based on the heat transfer formulation, through finite-difference numerical method and PSPICE computational tool. The feature to take the real temperature dependence of the materials properties into account is included in the computation.

In this paper we study a generalization of the Hubbard model by considering spin-spin interactions described by the exchange constant J. An external magnetic field his also taken into account. In the narrowband limit and for the 1D case, we present the exact solution obtained in the framework of the Greenâ??????s function formalism, using the Composite Operator Method. We report the T = 0 phase diagram for both ferro (J > 0) and anti-ferro (J < 0) couplings. The competition of the different energy scales (U, J, and h; being U the local charge interaction) generates a variety of phases and different charge and spin orderings.

The Formula Not Shown -extended Supersymmetric Quantum Mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its Universal Enveloping Superalgebra. Two constructions are possible. For even Formula Not Shown one can identify the 1D Formula Not Shown -extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist-deformed (anti)commutators. The main differences between an abelian twist defined in terms of fermionic operators and an abelian twist defined in terms of bosonic operators are discussed.

The N-extended supersymmetric quantum mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its universal enveloping superalgebra. Two constructions are possible. For even N one can identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist deformed (anti)commutators. The main differences between an abelian twist defined in terms of fermionic operators and an abelian twist defined in terms of bosonic operators are discussed. (author)

Mitochondria are the primary locus for the generation of reactive nitrogen species including peroxynitrite and subsequent protein tyrosine nitration. Protein tyrosine nitration may have important functional and biological consequences such as alteration of enzyme catalytic activity. In the present study, mouse liver mitochondria were incubated with peroxynitrite, and the mitochondrial proteins were separated by 1D and 2D gel electrophoresis. Nitrotyrosinylated proteins were detected with an anti-nitrotyrosine antibody. One of the major proteins nitrated by peroxynitrite was carbamoyl phosphate synthetase 1 (CPS1) as identified by LC-MS protein analysis and Western blotting. The band intensity of nitration normalized to CPS1 was increased in a peroxynitrite concentration-dependent manner. I...

Changes in the coolant core inlet temperature field, as they may be due to heat transfer disturbances in the steam generator, give rise to changes in the power density distribution inside the core. Thereby spatial xenon oscillations may be excited, which, under certain conditions, cause power oscillations between the coolant circuits with periods of about 1 d. The computer code ONYX has been developed to study those and other non-steady long-term processes in the WWER-440 primary circuit due to xenon poisoning.

We propose and experimentally demonstrate the nonlinear Talbot effect from nonlinear photonic crystals. The nonlinear Talbot effect results from self-imaging of the generated periodic intensity pattern at the output surface of the crystal. To illustrate the effect, we experimentally observed second-harmonic Talbot self-imaging from 1D and 2D periodically poled LiTaO(3) crystals. Both integer and fractional nonlinear Talbot effects were investigated. The observation not only conceptually extends the conventional Talbot effect, but also opens the door for a variety of new applications in imaging technologies. PMID:20482176

A 1D photonic crystal structure contains 16 layers, 8 common dielectric layers and 8 layers with nonlinear medium, with an arrangement similar to the 5th generation, Thue?Morse multilayer is presented. The properties of photonics band gap, field distribution and optical multistability are investigated. On the band gap, 5 resonant modes is observed. On the behavior of output intensity versus input intensity around resonant frequencies, the multistability response observed. When the frequency of incident field is close to the resonant frequency, the threshold intensity of multistability is decreased.

The nonlinear properties of quasiperiodic photonic crystals based on Thue-Morse sequence are investigated. The intrinsic asymmetry of these 1D structures for odd generation numbers results in bistability thresholds which are sensitive to propagation direction. Along with resonances of perfect transmission, this feature allows to obtain strongly nonreciprocal propagation and to create an all-optical diode (AOD). The efficiency of two schemes is compared: passive and active when an additional short-term pump signal is applied. The existence of stationary gap solitons for quasiperiodic photonic crystals is shown numerically, and their difference from the Bragg case is emphasized.

SummaryHere we show that yeast strains with reduced target of rapamycin (TOR) signaling have greater overall mitochondrial electron transport chain activity during growth that is efficiently coupled to ATP production. This metabolic alteration increases mitochondrial membrane potential and reactive oxygen species (ROS) production, which we propose supplies an adaptive signal during growth that extends chronological life span (CLS). In strong support of this concept, uncoupling respiration during growth or increasing expression of mitochondrial manganese superoxide dismutase significantly curtails CLS extension in tor1D strains, and treatment of wild-type strains with either rapamycin (to inhibit TORC1) or menadione (to generate mitochondrial ROS) during growth is sufficient to extend CLS. ...

The Bose-Einstein condensate (BEC), confined in a combination of the cigar-shaped trap and axial optical lattice, is studied in the framework of two models described by two versions of the one-dimensional (1D) discrete nonpolynomial Schroedinger equation (NPSE). Both models are derived from the three-dimensional Gross-Pitaevskii equation (3D GPE). To produce 'model 1' (which was derived in recent works), the 3D GPE is first reduced to the 1D continual NPSE, which is subsequently discretized. 'Model 2,' which was not considered before, is derived by first discretizing the 3D GPE, which is followed by the reduction in the dimension. The two models seem very different; in particular, model 1 is represented by a single discrete equation for the 1D wave function, while model 2 includes an additional equation for the transverse width. Nevertheless, numerical analyses show similar behaviors of fundamental unstaggered solitons in both systems, as concerns their existence region and stability limits. Both models admit the collapse of the localized modes, reproducing the fundamental property of the self-attractive BEC confined in tight traps. Thus, we conclude that the fundamental properties of discrete solitons predicted for the strongly trapped self-attracting BEC are reliable, as the two distinct models produce them in a nearly identical form. However, a difference between the models is found too, as strongly pinned (very narrow) discrete solitons, which were previously found in model 1, are not generated by model 2--in fact, in agreement with the continual 1D NPSE, which does not have such solutions either. In that respect, the newly derived model provides for a more accurate approximation for the trapped BEC.

Recent theoretical and experimental results demonstrate a close connection between the super-Tonks-Girardeau (STG) gas and a one-dimensional (1D) hard-sphere Bose (HSB) gas with hard-sphere diameter nearly equal to the 1D scattering length a{sub 1D} of the STG gas, a highly excited gaslike state with nodes only at interparticle separations |x{sub jl}|=x{sub node{approx_equal}}a{sub 1D}. It is shown herein that when the coupling constant g{sub B} in the Lieb-Liniger interaction g{sub B{delta}}(x{sub jl}) is negative and |x{sub 12}|{>=}x{sub node}, the STG and HSB wave functions for N=2 particles are not merely similar, but identical; the only difference between the STG and HSB wave functions is that the STG wave function allows a small penetration into the region |x{sub 12}|2. The STG and HSB wave functions for N=2 are given exactly in terms of a parabolic cylinder function, and for N{>=}2, x{sub node} is given accurately by a simple parabola. The metastability of the STG phase generated by a sudden change of the coupling constant from large positive to large negative values is explained in terms of the very small overlap between the ground state of the Tonks-Girardeau gas and collapsed cluster states.

The rupture speeds obtained by fracture experiments of monolithic brittle materials are usually by far lower than those predicted by theories and inferred from inversions of seismograms: Some seismic inversions even suggest the existence of supershear rupture speeds (i.e., rupture propagating faster than the relevant shear wave). Exceptionally, a few laboratory experiments of dynamic rupture on pre-cut interfaces do indicate that such high rupture speeds can be achieved (e.g. Uenishi et al., BSSA, 1999; Rosakis, Adv. Phys., 2002), but the discrepancies of rupture speeds between theories and experiments (and numerical simulations) cannot always be attributed to the observations that real solids have every kind of defects such as pre-existing discontinuities or microcracks generated during rupture propagation. Moreover, even when we accept the existence of such extraordinary high rupture speeds, the exact mechanism of the transition from sub-Rayleigh to supershear rupture speeds has not been clarified yet, and the question of whether natural earthquake ruptures can propagate at such high speeds is still under active debate (see e.g. Uenishi and Rossmanith, Acta Mech., 2002; Xia et al., Science, 2004). Recent large-scale atomistic simulations show that hyperelasticity, the nonlinear elasticity of large strains, may be able to play a governing role in the dynamics of brittle fracture (Buehler et al., Nature, 2003). This is in contrast to many existing theories of dynamic fracture where the linear elastic behavior of solids is usually assumed. Real solids like the crust, however, have elastic properties that are significantly different at various scales, for both small and large deformations. Here, we experimentally investigate dynamic fracture in hyperelastic materials in order to possibly explain the discrepancies described above. As a first step for further understanding of the effect of hyperelasticity on rupture initiation and propagation, we consider typical hyperelastic media, flat sheets of rubber (100mm high × 200mm wide × 0.1mm thick) and balloons, under static mode I loading conditions with crack- parallel (T-) stresses. The rupture (crack) initiation and propagation process is recorded utilizing a high- speed digital video camera at a frame rate of some microseconds. The results show that the dynamic crack behavior is more sensitive to the static loading conditions in the hyperelastic case than in the linear elastic case: (1) If the static T-stress is relatively small, upon crack initiation, the crack surfaces form an elliptical shape because large deformations are allowed in hyperelastic materials. Then, the crack wriggles and bifurcates, leaving a wavy pattern on the edges of the ruptured fragments; (2) If the magnitude of the static T- stress is comparable to that of the remote mode-I loading stress, the crack propagates surprisingly straight and crack front, forming a very sharp wedge-shape, accelerates from sub-Rayleigh to a constant supershear speed and then captures the shear wave front generated upon rupture initiation. These experimental results suggest - if the hyperelastic constitutive relation can be assumed - cracks may reach supershear speeds even when material heterogeneities do not exist, giving possibly a new hint on the question of whether natural earthquake ruptures can really accelerate to such extraordinary high speeds as have been inferred from seismological inversions. u.ac.jp/~uenishi/

This report outlines a method of using empirical Green's functions in an earthquake simulation program EMPSYN that provides realistic seismograms from potential earthquakes. The theory for using empirical Green's functions is developed, implementation of the theory in EMPSYN is outlined, and an example is presented where EMPSYN is used to synthesize observed records from the 1971 San Fernando earthquake. To provide useful synthetic ground motion data from potential earthquakes, synthetic seismograms should model frequencies from 0.5 to 15.0 Hz, the full wave-train energy distribution, and absolute amplitudes. However, high-frequency arrivals are stochastically dependent upon the inhomogeneous geologic structure and irregular fault rupture. The fault rupture can be modeled, but the stochastic nature of faulting is largely an unknown factor in the earthquake process. The effect of inhomogeneous geology can readily be incorporated into synthetic seismograms by using small earthquakes to obtain empirical Green's functions. Small earthquakes with source corner frequencies higher than the site recording limit f{sub max}, or much higher than the frequency of interest, effectively have impulsive point-fault dislocation sources, and their recordings are used as empirical Green's functions. Since empirical Green's functions are actual recordings at a site, they include the effects on seismic waves from all geologic inhomogeneities and include all recordable frequencies, absolute amplitudes, and all phases. They scale only in amplitude with differences in seismic moment. They can provide nearly the exact integrand to the representation relation. Furthermore, since their source events have spatial extent, they can be summed to simulate fault rupture without loss of information, thereby potentially computing the exact representation relation for an extended source earthquake.

A summary of the development of a novel optical remote sensing (ORS) method that determined fugitive dust emission factors for unique military activities is described for puff and mobile sources. Four field campaigns characterized artillery back blasts as puff sources (M549A1 and M107), and movement of military vehicles (M1A1, M113, Bradley Fighting Vehicle (BFV), M88, M270, M577, and HEMTT) and an airborne helicopter (Bell 210) as mobile sources. The ORS method includes a Micro-Pulse Lidar (MPL) and a reflective target that determines one-dimensional (1-D) light extinction coefficient profiles. The MPL was mounted on a positioner that allows the MPL to automatically scan vertically, which allowed 1-D extinction coefficient profiles to be measured at select angles from horizontal. Two-dimensional (2-D) light extinction coefficient profiles were then determined by interpolating the 1-D extinction profiles measured at select angles. Dust property, in the form of the mass extinction efficiency (MEE), was measured using Open Path- Fourier Transform Infrared Spectrometry (OP-FTIR) and Open Path- Laser Transmissometry (OP-LT) in the first three field campaigns and an OP-LT and DustTrak™ in the fourth field campaign. MEE was used to convert the 2-D light extinction coefficient profiles to 2-D dust mass concentration profiles. Emission factors were determined by integrating the 2-D mass concentration profiles with measured wind vectors. Results from these field campaigns show that: 1) artillery with stronger recoiling forces generates more fugitive dust; 2) the dust emission factors for tracked vehicles are correlated with vehicle momentum; 3) emission factor decreases with increasing speed for airborne helicopters; and 4) wheeled vehicles (HEMTT) generate more fugitive dust than tracked vehicles (M88, M270, M577).

Abstract The GEOsciences Network (GEON, ) is a large scale collaborative cyberinfrastructure project involving information technology and geoscience researchers from multiple institutions. The GEON infrastructure provides portal, middleware, and data resources to facilitate scientific discovery for domain scientists using applications, tools, and services. It consists of both a service oriented Web/Grid framework and application toolkits, using the Web service and portlet programming model to represent applications. Based on those grid environments, we have developed the SYNSEIS (SYNthetic SEISmogram) tool within the GEON infrastructure to support personalized experiments in seismology. In this paper, we present an overview of SYNSEIS from a user point of view, and demonstrate how one can ...

Seismic data from two explosions was processed using the Systems Science and Software MARS (Multiple Arrival Recognition System) seismic event detector in an effort to determine their relative spatial and temporal separation on the basis of seismic data alone. The explosions were less than 1.0 kilometer apart and were separated by less than 0.5 sec in origin times. The seismic data consisted of nine local accelerograms (r < 1.0 km) and four regional (240 through 400 km) seismograms. The MARS processing clearly indicates the presence of multiple explosions, but the restricted frequency range of the data inhibits accurate time picks and hence limits the precision of the event location.

Abstract in english The PrP C prion protein contains 250 amino acids with some variation among species and is expressed in several cell types. PrP C is converted to PrP Sc by a post-translational process in which it acquires amino acid sequences of three-dimensional conformation of beta-sheets. Variations in the prion protein gene were observed among 16 genera of New World primates (Platyrrhini), and resulted in amino acid substitutions when compared with the human sequence. Seven substituti (more) ons not yet described in the literature were found: W -> R at position 31 in Cebuella, T -> A at position 95 in Cacajao and Chiropotes, N-> S at position 100 in Brachyteles, L -> Q at position 130 in Leontopithecus (in the sequence responsible for generating the beta-sheet 1), D -> E at position 144 in Lagothrix (in the sequence responsible for the alpha-helix 1), D-> G at position 147 in Saguinus (also located in the alpha-helix 1 region), and M -> I at position 232 in Alouatta. The phylogenetic trees generated by parsimony, neighbor-joining and Bayesian analyses strongly support the monophyletic status of the platyrrhines, but did not resolve relationships among families. However, the results do corroborate previous findings, which indicate that the three platyrrhine families radiated rapidly from an ancient split.

Botanical dietary supplements and herbal remedies are widely used for health promotion and disease prevention. Due to the high chemical complexity of these natural products, it is essential to develop new analytical strategies to guarantee their quality and consistency. In particular, the precise characterization of multiple botanical markers remains a challenge. This study demonstrates how a combination of computer-aided spectral analysis and 1D quantitative ¹H NMR spectroscopy (qHNMR) generates the analytical foundation for innovative means of simultaneously identifying and quantifying botanical markers in complex mixtures. First, comprehensive ¹H NMR profiles (fingerprints) of selected botanical markers were generated via ¹H iterative full spin analysis (HiFSA) with PERCH. Next, the ¹H fingerprints were used to assign specific ¹H resonances in the NMR spectra of reference materials, enriched fractions, and crude extracts of Ginkgo biloba leaves. These ¹H fingerprints were then used to verify the assignments by 2D NMR. Subsequently, a complete purity and composition assessment by means of 1D qHNMR was conducted. As its major strengths, this tandem approach enables the simultaneous quantification of multiple constituents without the need for identical reference materials, the semiquantitative determination of particular subclasses of components, and the detection of impurities and adulterants. PMID:22332915

The NUMEL suite of programs are the UK reference 1D codes for thermal-hydraulic assessment of the steady-state, static and dynamic stability, and transient responses of steam generators. A large part of NUMEL validation was carried out by comparing the code predictions with the experimental rig data obtained from the Boiler Dynamics Rig (BDR) at MEL. As part of the on-going Quality Assurance (QA) support for NUMEL several series of benchmark tests are underway on the rig, involving the provision of detailed documented records for code validation. The document presents the Reference Dataset for NUMEL dedicated to providing a quantitative representation of the three steam generating tubes that form the BDR test section. Contained in the document are details of the derivation of the dataset from design drawings and specifications of correlation equations incorporated in the NUMEL dataset for heat transfer, dryout, friction factor, two-phase slip ratio and physical properties. The document details Version 1 of the Reference Dataset.

We have experimentally investigated supercontinuum generation in a conventional single-mode fiber pumped with a nanosecond pulse source. The experimental results show that, when pump power increases, the spectral flatness is improved obviously and the spectral broadening only occurs in a red-shifted radiation rather than a blue-shifted radiation. A supercontinuum source is experimentally reported with a flatness of 4.7 dB over 180 nm (ranging from 1555 to >1735 nm) at pump power P R = 5 W and is predicted to have the flatness of less than 1 dB at P R > 8 W. The cascade of stimulated Raman scattering (SRS) together with soliton fission plays the key roles in supercontinuum generation.

We have studied experimentally the efficiency of the harmonics from solid surface plasma by varying the electron density scale length produced during the interaction of a 2.2 ps, 100 mJ, 1054 nm, p-polarized laser pulse with deposited Al targets. Although third harmonic radiation can also be observed when a single beam is used, an approximately 5 ps time difference between the prepulse and the main pulse results in an increase in the harmonic signal by a factor of 2-3, which then decreases after 10 ps. The results for the 4th- and 5th-order harmonic generation are also similar. We have also calculated the electron density scale length by using the one-dimensional (1D) hydrodynamic code HYADES. The calculation results are in good agreement with our experimental results. It is found that it is possible to generate high efficiency harmonics by controlling the density gradient using a double laser pulse.   

Several physically-based models that couple 1D or 2D surface and 3D subsurface flow have recently been developed, but few studies have evaluated the errors directly associated with the different coupling schemes. In this paper we analyze the causes of mass balance error for a conventional and a modified sequential coupling scheme in worst-case scenario simulations of Hortonian runoff generation on a sloping plane catchment. The conventional scheme is noniterative, whereas for the modified scheme the surface-subsurface exchange fluxes are determined via a boundary condition switching procedure that is performed iteratively during resolution of the nonlinear subsurface flow equation. It is shown that the modified scheme generates much lower coupling mass balance errors than the conventional ...

We report on the generation of a stable continuous-wave low-frequency squeezed vacuum field with a squeezing level of $3.8\\pm0.1$ dB at 1064 nm, the wavelength at which laser interferometers for gravitational wave (GW) detection operate, using periodically poled KTiOPO$_4$ (PPKTP) in a sub-threshold optical parametric oscillator. PPKTP has the advantages of higher nonlinearity, smaller intra-crystal and pump-induced seed absorption, user-specified parametric down-conversion temperature, wider temperature tuning range, and lower susceptibility to thermal lensing over alternative nonlinear materials such as MgO doped or periodically poled LiNbO$_3$, and is, therefore, an excellent material for generation of squeezed vacuum fields for application to laser interferometers for GW detection.

Abstract Bead-shaped 1D structures are of great interest due to their unique applications in mesoscopic optics/electronics and their specific ability to collect tiny droplets. Here, a novel method to fabricate aligning bead-shaped nanowire arrays assisted by highly adhesive superhydrophobic surfaces based on a micropillar guiding strategy is presented. Different from previous fabrication techniques, bead-shaped nanowires generated in this method are strictly oriented in a large scale. Rayleigh instability, which occurs at ultralow polymer concentration, can introduce bead-shaped nanowires at the cost of structural strength. Thus, PS spheres are more suitable to serve as bead building blocks to generate firm bead-shaped nanowire arrays. The bead number is tunable by tailoring the polystyren...

Gemlik Gulf is an oval-shaped transtensional basin with a maximum depth of 113 m, located on the middle strand of the North Anatolian Fault (NAF) in the eastern part of the Sea of Marmara (SOM). During the last glacial period until the Holocene marine transgression about 12 ka BP, the sea level was below the Çanakkale (Dardanelles) Strait's bedrock sill depth of -85 m, and the Gemlik Basin became a lake isolated lake from the rest of the Sea of Marmara "Lake" and the global ocean. The high resolution seismic profiles and the multi- beam bathymetric map of the basin show that the basin is characterized by NW-SE trending transtensional oblique faults, delta lobes of the Büyükdere (Kocadere) to the east and an erosional surface below an up to 15 m-thick Holocene mud drape. The Holocene mud drape was studied in up to 9.5 m-long gravity-piston and 0.84 m-long sediment/water interface cores located at -105 to -113 m in the basin's depocentre. The Holocene mud consists mainly of plastic gray green marine clayey mud that includes thick-red brown clay layers and a laminated organic-rich, dark olive green sapropel in the lower part, which was previously dated at 11.6-6.4 14Ckyr (uncalib) BP. Multi-proxy analyses of the Holocene mud drape in the sediment cores were carried out using Multisensor Core Logger, XRF Core Scanner equipped with digital X-Ray radiography, and laser particle size analyzer. Seismic-core correlation was made using seismic data of the chirp profiles at the core locations and the synthetic seismograms generated using the MSCL P-wave velocity and gamma density measurements. The long piston-gravity cores include five 20 to 100 mm-thick "red brown mud layers" in the top 2.5 m of the core. These layers have a sharp basal boundary and gradational upper boundary. The red brown layers consist of 55-75% clay-size material with an average grain size of 3-4 µm, and have relatively a high magnetic susceptibility. They are enriched in K, Fe, Ti and Zr that are the proxy of detrital mineral input, and depleted in Ca, Br, Fe and Mn. Manganese shows a sharp enrichment immediately below the base of the red brown layers. All these features strongly suggest that the red layers represent the distal edges mass flow deposits, possibly sourced from the delta to the east. The distinct Mn enrichments below the base of the red brown layers represent the diagenetic enrichment at the oxic/anoxic boundary near the seafloor, which was later covered by the mass flow deposit. C-14 and radionuclide datings of the mass flow layers and investigation of their possible relation to the past earthquakes are under progress.

The 4 component multi-source/multi-offset VSP (Vertical Seismic Profile) conducted at the Soultz-sous-Forêts EGS (Enhanced Geothermal System) site in 2007 provides records of seismic waves recorded in the fractured granite basement within wells GPK3 and GPK4. Waves generated at 26 surface positions, located at distances between 500m and 5km from the well head in different azimuths, are recorded by 3 component geophones at depths between 5000m and 3000m with a 20m depth interval. The seismic source is a vibrator emitting a 16s long sweep with frequencies varying linearly between 8 and 88 Hz. Two shot locations were simultaneously recorded, one with an upsweep [8 to 88Hz], the other with a downsweep [88 to 8Hz]. Successive correlation with the two sweeps allows retrieving distinct seismograms for each shot from the mixed raw uncorrelated records. Most records show clear downgoing P and S waves. Detecting waves reflected or diffracted by fractures intersecting the wells requires extracting low amplitude upgoing waves from the dominant downgoing wavefield. However, the up to 30° inclination of the well relative to the vertical and the 60 to 90° dips of the fracture zones make the separation of the different waves complex. The wavefield separation of the vertical geophone component is done in the frequency-wavenumber Fourier domain which separates waves according to their apparent velocity across the receiver antenna. Picking of the first arrival times and shifting times allows aligning predominant P wave downgoing wavefield at constant times, or infinite apparent velocity in Fourier domain. Filtering the infinite apparent velocity attenuates all the waves having the same apparent velocity as the first arrivals. A second filtering at the downgoing S waves velocities is then applied, providing two downgoing wavefields, one for the P waves and the other for the S waves. The residuals correspond to the upgoing wavefield. To reduce the reverberations in the upgoing wavefield, we apply a Wiener deconvolution. Faint coherent waves that may originate from fractures are observed in restricted depth intervals. In order to model the arrival times of the extracted reflections/diffractions at the different shot positions, we need a velocity model of the 1400m thick sedimentary cover. P velocities from VSP data of one shot recorded in well GPK4 in sediments and structural information from geological logs and interpreted surface seismic profiles are used to build an initial 3D model with 3 layers separated by dipping plane interfaces. 3D ray tracing is used to compute first arrival times and adjust our model to the data, by modifying the dip of the interfaces. It is then possible to adjust the upgoing waves arrival times to reflections or diffractions on fractures in the reservoir.

The IRIS Education and Outreach (E&O) Program is committed to making significant and lasting contributions to science education, science literacy and the general public's understanding of the Earth, using seismology and the unique resources of the IRIS consortium. The E&O program has activities that span all educational levels from public outreach to K-12 and college education. The activities are designed for a wide range of individual interaction time, from minutes for a museum display to an entire summer for an undergraduate research internship. In general, the longer the interaction time, the smaller the audience. The educational goals for a particular audience, as stated in the E&O Program plan, define whether an activity is focused more on breadth of audience or depth of content. An activity's ability to meet the educational goals of the E&O program is the most important criteria in assessing its value. However, to help determine which activities are most worthy of continued support and to help select new activities to engage in, we have begun estimating the cost of providing each hour of interaction time for an activity. The lower the cost for each person-hour of interaction, the more efficient the activity, assuming maximum effectiveness of each activity. Thus the importance of assessment is magnified, as a more effective activity could cost more per person-hour and still be supported if no equally effective but more efficient activity is viable. As an example of how resources are divided between different activities, two activities that have similar budgets but very different goals, content depth and audience sizes are our museum program and our professional development workshops. The museum program, a partnership between IRIS, the US Geological Survey, and several major museums across the nation, reaches large audiences (up to 16 million people per year) via 1 traveling and 4 permanent exhibits. The exhibits include real-time earthquake location maps and continuous seismograms from multiple global seismograph stations, providing wide exposure to seismology, though for a very limited time per individual. One-day professional development workshops provide content knowledge and classroom activities modeled using inquiry-based instructional practices. Approximately 140 teachers and college faculty attended IRIS-led workshops in the past year. The time spent with a limited number of teachers is leveraged through each teacher's interactions with a much larger number of students. When teacher-student interactions for 1-2 years after attending a workshop are included in the estimation of person-hours of interaction time, the museum and workshop programs generate a similar total interaction with the target audiences. Thus by this simple measure, the two programs are roughly equally efficient uses of E&O program resources, even though the target audiences, level of content depth and number of people engaged are very different. Using this measure, it is possible to assess if the relative cost of different activities matches the relative importance of the goals they are addressing.

The 1909 April 14 Taiwan earthquake caused significant damage in Taipei. Most of the information on this earthquake available until now is from the written reports on its macro-seismic effects and from seismic station bulletins. In view of the importance of this event for assessing the shaking hazard in the present-day Taipei, we collected historical seismograms and station bulletins of this event and investigated them in conjunction with other seismological data. We compared the observed seismograms with those from recent earthquakes in similar tectonic environments to characterize the 1909 earthquake. Despite the inevitably large uncertainties associated with old data, we conclude that the 1909 Taipei earthquake is a relatively deep (50-100 km) intraplate earthquake that occurred within the subducting Philippine Sea Plate beneath Taipei with an estimated MW of 7 ± 0.3. Some intraplate events elsewhere in the world are enriched in high-frequency energy and the resulting ground motions can be very strong. Thus, despite its relatively large depth and a moderately large magnitude, it would be prudent to review the safety of the existing structures in Taipei against large intraplate earthquakes like the 1909 Taipei earthquake.

In the Srednesyrdar'inskiy depression, a very distinct reference reflecting level ''V'' is traced everywhere on the boundary of the Cretaceous and Paleogene. It is represented by a bed of anhydrite among the surrounding sandy-argillaceous deposits. Because of the relatively high V /SUB pl/ =5000-6000 m/sec, /tau/=2.65-2.85 g/sm, the coefficient of wave reflection requires high values (A /SUB pp/ =0.4-0.5). On the seismograms of the position observations from the reference level ''V'' multiple-reflected waves are recorded to have great intensity, dominate on the seismograms and do not make it possible to isolate waves which are reflected from the levels of the Mesozoic and Paleozoic. With the use of constant reference well points of seismic observations (POSPsn, development of ''SerdazNIPIneft'') a study was made of the wave patterns in the inner points of the medium and on the surface. Seismic information was obtained from the Mesozoic and Paleozoic masses and its reality was appraised.

In this study, we calculate the high-frequency attenuation parameter ?, proposed by Anderson and Hough (1984), based on the seismograms recorded by stations, which located in the Taipei basin. The time windows applied to seismograms are suggested to be shear waves that are transformed to spectrum by the Fourier transform technique. When frequency is greater than a specific frequency, the spectral amplitudes decay exponentially with frequency, which can be described as A(f)=A0*exp(-??f), where A(f) is the spectral amplitude, and A0 depends on the earthquake source and epicenter distance, f is the frequency, and the value of ? is independent of frequency, but varied with earthquake magnitude and distance from source, unit in second (Anderson and Hough, 1970; Tsai and Chen, 2000; Castro et al., 2000). As well as the Q(f) around the Taipei basin can be obtained via modeling the spectra of specific sites and removing the source term and site one. The results can be used in the technique of stochastic prediction of ground motion (Boore and Atkinson, 1987; Sokolov et al., 2009).

Partial contents of papers presented include: A Generalized Likelihood Ratio Test in Outlier Detection or Script Matching; Analysis of Regional Bodywave Phases from Earthquakes in West China; Numerical Models of Quarry Blast Sources; Regional Seismic Event Discriminants -- What Works, What Doesn't and Why; Seismic Discrimination of Rockbursts in Mines; Deep Seismic Soundings in Northern Eurasia -- Interpretation of the Murmansk-Kizil Ultra-Long-Range Profile; Non-Linear Attenuation in the Near Source Region -- Characterization of Hysteresis in the Deformationof Rock Joints; Epicentral Azimuth Determination by Mini Array Processing; Source Function Deconvolution of Delay-Fired Explosions and Earthquakes at Regional Distances; Regional Wave Attenuation in Eurasia; Effects of an Irregular Free Surface and Moho on Regional Wave Propagation; Global Seismic Evidence Combination; Generalized Ray/Born Synthesis of Complete Regional Seismograms in Three-Dimensional Crustal Models; An X-Windows Graphics Tool to Compute Synthetic Seismograms for 2-D Models Using Gaussian Beams; Seismic Array Study of the Baikal Rift Zone, Siberia; Numerical Simulation of Nonlinear Attenuation Using an Endochronic Formulation; Applications of Array Spectral Factorization Methods to Regional Seismic Discrimination and Three-Component Processing; A Network-Accessible Geological and Geophysical Database for Eurasia; Multivariate Seismic Calibration for the Novaya Zemlya Test Site;and Ground-Truth Data for Seismic Discrimination Research.

Injection and movement/saturation of carbon dioxide (CO2) in a geological formation will cause changes in seismic velocities. We investigate the capability of coda-wave interferometry technique for estimating CO2-induced seismic velocity changes using time-lapse synthetic vertical seismic profiling (VSP) data and the field VSP datasets acquired for monitoring injected CO2 in a brine aquifer in Texas, USA. Synthetic VSP data are calculated using a finite-difference elastic-wave equation scheme and a layered model based on the elastic Marmousi model. A possible leakage scenario is simulated by introducing seismic velocity changes in a layer above the CO2 injection layer. We find that the leakage can be detected by the detection of a difference in seismograms recorded after the injection compared to those recorded before the injection at an earlier time in the seismogram than would be expected if there was no leakage. The absolute values of estimated mean velocity changes, from both synthetic and field VSP data, increase significantly for receiver positions approaching the top of a CO2 reservoir. Our results from field data suggest that the velocity changes caused by CO2 injection could be more than 10% and are consistent with results from a crosswell tomogram study. This study demonstrates that time-lapse VSP with coda-wave interferometry analysis can reliably and effectively monitor geological carbon sequestration.

Several acutely acting antimigraine drugs, including sumatriptan and other second generation 5-HT1D receptor agonists, have the ability to constrict porcine carotid arteriovenous anastomoses as well as the human isolated coronary artery. These two experimental models seem to serve as indicators, respectively, for the therapeutic and coronary side-effect potential of the compounds. Using these two models, we have now investigated the effects of GMC2021 (3-[2-(dimethylanimo)ethyl]-5-[(trifluoromethyl)sulfonyl]oxy][1 H]indole oxalate, a close analogue of sumatriptan. GMC2021 (30, 100, 300 and 1000 micrograms.kg-1, i.v.) decreased the total carotid blood flow by exclusively decreasing arteriovenous anastomotic blood flow; capillary blood flow to the skin and ears was moderately increased. The mean +/- S.E.M. dose of GMC2021 eliciting a 50% decrease (ED50) in the porcine carotid arteriovenous anastomotic blood flow was found to be 1.1 +/- 0.3 mumol.kg-1 and the highest dose (1000 micrograms.kg-1) produced a 67 +/- 4% reduction. The carotid haemodynamic effects of GMC2021 were reduced by the selective 5-HT1D receptor antagonist, GR127935 (N-[methoxy-3-(4-methyl-1- piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)[1 , 1-biphenyl]-4-carboxamide hydrochloride), which completely antagonizes porcine carotid haemodynamic responses to sumatriptan (ED50: 0.16 mumol.kg-1, i.v.). Compared to sumatriptan (pD2: 6.12 +/- 0.15; Emax: 31.3 +/- 12.3% of contractions to 100 mM K+), GMC2021 was less potent in constricting the human isolated coronary artery (pD2: 5.45 +/- 0.2; Emax: 21.0 +/- 4.8% of contractions to 100 mM K+). The above results suggest that GMC2021 constricts carotid arteriovenous anastomoses partly by a 5-HT1D receptor and partly by another, probably novel, receptor and that GMC2021 should be able to abort migraine headaches in patients, with perhaps a less propensity for coronary side effects. PMID:8891578

Plane-wave responses of vertically heterogeneous structure models (1-D media) are often computed in seismology. For horizontally layered media, they can be calculated by semi-analytical methods such as the propagator matrix method. However, for the gradient velocity or randomly heterogeneous structures, we have to use numerical methods such as the finite-difference method. The conventional codes for the 2-D or 3-D finite-difference method require huge computer memory and long computation time even for calculating plane-wave responses of 1-D media. In this study we propose an efficient procedure to calculate plane-wave responses of arbitrary 1-D media using the finite-difference method. We first derive an elastodynamic equation of plane-wave incidence problem for vertically heterogeneous media by applying the Snell's law to 3-D elastodynamic equation. We then discretize the velocity-stress formulation of the derived elastodynamic equation using a staggered-grid finite-difference scheme of fourth-order accurate in space and second-order accurate in time. We also investigate the implement of the stress-free surface condition for the scheme, and perform a stability check of the total scheme through actual computations using a Fortran code based on it. We computed plane-wave responses of structure model with velocity gradient using the derived finite-difference method. We focused on the PS-converted phase and found a ``offset" phase appearing between the PS-converted phases generated at the top and bottom boundaries of a velocity-gradient layer on the surface responses of a structure model with velocity gradient due to a P-wave incidence. This phase can be emphasized by calculating the receiver function from the radial and vertical waveforms. In this study we also investigate the ``offset" phase attributed to the velocity gradient by numerical computations using the derived finite-difference method.

1. The alpha(1)-adrenergic responses of rat aorta and tail artery have been analysed measuring the contractility and the inositol phosphate (IP) formation induced by noradrenaline. Three antagonists, prazosin, 5-methylurapidil (alpha(1A) selective) and BMY 7378 (alpha(1D) selective) have been used in different experimental procedures. 2. Noradrenaline possesses a greater potency inducing contraction and IP accumulation in aorta (pEC(50)-contraction=7.32+/-0.04; pEC(50)-IPs=6.03+/-0.08) than in the tail artery (pEC(50)-contraction=5.71+/-0.07; pEC(50)-IPs=5.51+/-0.10). Although the maximum contraction was similar in both tissues (E(max)-tail=619.1+/-55.6 mg; E(max)-aorta-698.2+/-40.8 mg), there were marked differences in the ability of these tissues to generate intracellular second messengers the tail artery being more efficient (E(max)-tail=1060+/-147%; E(max)-aorta=108.1+/-16.9%). 3. Concentration response curves of noradrenaline in presence of antagonist together with concentration inhibition curves for antagonists added before (CICb) or after (CICa) noradrenaline-induced maximal response in Ca(2+)-containing or Ca(2+)-free medium have been performed. A comparative analysis of the different procedures as well as the mathematical approaches used in each case to calculate the antagonist potencies, were completed. 4. The CICa was the simplest method to characterize the predominant alpha(1)-adrenoceptor subtype involved in the functional response of a tissue. 5. In aorta, where constitutively active alpha(1D)-adrenoeptors are present, the use of different experimental procedures evidenced a complex equilibrium between alpha(1D)- and alpha(1A)-adrenoceptor subtypes. 6. The appropriate management of LiCl in IP accumulation studies allowed us to reproduce the different experimental procedures performed in contractile experiments giving more technical possibilities to this methodology. PMID:12540527

Type 1 diabetes (T1D) increases the risk of adverse coronary events. Among risk factors, dyslipidemia due to altered hepatic lipoprotein metabolism plays a central role in diabetic atherosclerosis. Nevertheless, the likely alterations in plasma lipid/lipoprotein profile remain unclear, especially in the context of spontaneously developed T1D and atherosclerosis. To address this question, we generated Ins2(+/Akita):apoE(-/-) mouse by cross-breeding Ins2(+/Akita) mouse (which has Ins2 gene mutation, causing pancreatic ?-cell apoptosis and insulin deficiency) with apoE(-/-) mouse. Ins2(+/Akita):apoE(-/-) mice developed T1D spontaneously at 4-5 wk of age. At 25 wk of age and while on a standard chow diet, diabetic Ins2(+/Akita):apoE(-/-) mice exhibited an approximately threefold increase in atherosclerotic plaque in association with an approximatelty twofold increase in plasma non-HDL cholesterol, predominantly in the LDL fraction, compared with nondiabetic controls. To determine factors contributing to the exaggerated hypercholesterolemia, we assessed hepatic VLDL secretion and triglyceride content, expression of hepatic lipoprotein receptors, and plasma apolipoprotein composition. Diabetic Ins2(+/Akita):apoE(-/-) mice exhibited diminished VLDL secretion by ~50%, which was accompanied by blunted Akt phosphorylation in response to insulin infusion and decreased triglyceride content in the liver. Although the expression of hepatic LDL receptor was not affected, there was a significant reduction in the expression of lipolysis-stimulated lipoprotein receptor (LSR) by ~28%. Moreover, there was a marked decrease in plasma apoB-100 with a significant increase in apoB-48 and apoC-III levels. In conclusion, exaggerated hypercholesterolemia and atherosclerosis in spontaneously diabetic Ins2(+/Akita):apoE(-/-) mice may be attributable to impaired lipoprotein clearance in the setting of diminished expression of LSR and altered apolipoprotein composition of lipoproteins. PMID:21447785

While the number of man-made nano superstructures realized by self-assembly is growing in recent years, assemblies of conductive polymer nanocrystals, especially for superlattices, are still a significant challenge, not only because of the simplicity of the shape of the nanocrystal building blocks and their interactions, but also because of the poor control over these parameters in the fabrication of more elaborate nanocrystals. Here, we firstly report a facile and general route to a new generation of 3D layered superlattices of polyaniline doped with CSA (PANI-CSA) and show how PANI crystallize and self-assemble, in a suitable single solution environment. In cyclohexane, 1D amorphous nanofibers transformed to 1D nanorods as building blocks, and then to 2D single-crystal nanosheets with a hexagonal phase, and lastly to 3D ordered layered superlattices with the narrowest polydispersity value (M(w)/M(n) = 1.47). Remarkably, all the instructions for the hierarchical self-assembly are encoded in the layered shape in other non-polar solvents (hexane, octane) and their conductivity in the ?-? stacking direction is improved to about 50 S cm(-1), which is even higher than that of the highest previously reported value (16 S cm(-1)). The method used in this study is greatly expected to be readily scalable to produce superlattices of conductive polymers with high quality and low cost. PMID:22609947

Radiance data obtained from NASA's Advanced Infrared Sounder (AIRS) is used in an attempt to improve the mesoscale prediction of temperature and moisture using one- and four-dimensional variational data assimilation (1D/4D-Var). The joint National Center for Atmospheric Research and Pennsylvania State University fifth-generation mesoscale model (MM5) along with the Stand-alone AIRS Radiative Transfer Algorithm (SARTA) is selected for this project. This work aims to utilize AIRS "clear-channel" radiances to enhance the first-guess analysis regarding the temperature and moisture content as a precursor to improving short-term precipitation forecasts. The adjoint operator for SARTA has been derived and linked to the MM5 adjoint modeling system; a "clear-channel" identification scheme, which is compatible with SARTA, has been developed and verified; and a set of one-dimensional variational data assimilation (1D-Var) experiments have been done in order to determine the impact of AIRS channels on the vertical profiles of temperature and moisture. Lastly, a preliminary 4D-Var experiment is carried out to determine the impact of a limited number of clear-channel AIRS radiances on the prediction of temperature and moisture. An adjoint-sensitivity based forecast verification technique is used to compare the 4D-Var forecast results to a control forecast.

This paper reports an inverse arc-modulated radiation therapy planning technique based on linear models. It is implemented with a two-step procedure. First, fluence maps for 36 fixed-gantry beams are generated using a linear model-based intensity-modulated radiation therapy (IMRT) optimization algorithm. The 2D fluence maps are decomposed into 1D fluence profiles according to each leaf pair position. Second, a mixed integer linear model is used to construct the leaf motions of an arc delivery that reproduce the 1D fluence profile previously derived from the static gantry IMRT optimization. The multi-leaf collimator (MLC) sequence takes into account the starting and ending leaf positions in between the neighbouring apertures, such that the MLC segments of the entire treatment plan are deliverable in a continuous arc. Since both steps in the algorithm use linear models, implementation is simple and straightforward. Details of the algorithm are presented, and its conceptual correctness is verified with clinical cases representing prostate and head-and-neck treatments.

High energy radiography capabilities are essential for many future DNT/HED experiments on NIF. We have been developing bright, high-energy (15-100 keV), high resolution (< 20 {micro}m), 1-D and 2-D radiography solutions for DNT experiments on NIF. In this LDRD, we have made significant progress utilizing high-energy, high-intensity, short-pulse lasers to generate hard K-{alpha} photons. High energy K-{alpha} sources are created by hot electrons interacting in the target fluor material after irradiation by lasers with intensity I{sub L} > 10{sup 17} W/cm{sup 2}. High resolution point projection 1-D and 2-D radiography have been achieved using {mu}-foil and {mu}-wire targets attached to low-Z substrate materials. The {mu}-wire size was 10 x 10 x 300 {micro}m on a 300 x 300 x 5 {micro}m CH substrate creating the point source size equivalent to these micro targets. This unique technique will utilize the NIF short pulse laser (ARC) as a backlighter suitable for the full range of DNT science experiments on NIF.

Most experiments on neutron or heavy-ion cascade-produced irradiation of pure metals and metallic alloys demonstrate unlimited void growth as well as development of the dislocation structure. In contrast, the theory of radiation damage predicts saturation of void swelling at sufficiently high irradiation doses and, accordingly, termination of accumulation of interstitial-type defects. It is shown in the present paper that, under conditions of steady production of one-dimensionally (1-D) mobile clusters of self-interstitial atoms (SIAs) in displacement cascades, any one of the following three conditions can result in indefinite damage accumulation. First, if the fraction of SIAs generated in the clustered form is smaller than some finite value of the order of the dislocation bias factor. Second, if solute, impurity or transmuted atoms form atmospheres around voids and repel the SIA clusters. Third, if spatial correlations between voids and other defects, such as second-phase precipitates and dislocations, exist that provide shadowing of voids from the SIA clusters. The driving force for the development of such correlations is the same as for void lattice formation and is argued to be always present under cascade-damage conditions. It is emphasised that the mean-free path of 1-D migrating SIA clusters is typically at least an order of magnitude longer than the average distance between microstructural defects; hence spatial correlations on the same scale should be taken into consideration. A way of developing a predictive theory is discussed. An interpretation

Four different strategies of pulping and bleaching were carried out to develop alternative mechanistic ecoenvironmental friendly approaches and generated effluent was characterised. Strategy-I included Phanerochaete sp. fungal pretreatment followed by conventional bleaching, whereas in strategy-II, fungal pretreatment was followed by enzyme xylanase aided bleaching. Strategy-III also included xylanase supplement but without prior fungal pretreatment. Chemically driven pulping and bleaching was the IV strategy. Conventional C(D)E(OP)D1D2 sequence of bleaching was used for strategy-I and IV whereas XC(D)E(OP)D1D2 sequence was applied to strategy-I and III. Strategy-II was responsible for 27.5% reduction in Kappa no. whereas the maximum (27.5%) reduction in refining energy was observed with strategy-II. Biobleaching strategies-II and III were helpful in saving 37.3 and 20.3% of elemental chlorine (Cl2) and 30.8 and 23.1% of chlorine dioxide (ClO2) respectively. In comparison to control (strategy-IV), strategy II resulted in maximum pollution load reduction of chemical oxygen demand (COD), biological oxygen demand (BOD), color and adsorbable organic halides (AOX) up to 57, 60, 30 and 43.6%, respectively. PMID:23033684

An easy access to a library of simple organic salts derived from tert-butoxycarbonyl (Boc)-protected L-amino acids and two secondary amines (dicyclohexyl- and dibenzyl amine) are synthesized following a supramolecular synthon rationale to generate a new series of low molecular weight gelators (LMWGs). Out of the 12 salts that we prepared, the nitrobenzene gel of dicyclohexylammonium Boc-glycinate (GLY.1) displayed remarkable load-bearing, moldable and self-healing properties. These remarkable properties displayed by GLY.1 and the inability to display such properties by its dibenzylammonium counterpart (GLY.2) were explained using microscopic and rheological data. Single crystal structures of eight salts displayed the presence of a 1D hydrogen-bonded network (HBN) that is believed to be important in gelation. Powder X-ray diffraction in combination with the single crystal X-ray structure of GLY.1 clearly established the presence of a 1D hydrogen-bonded network in the xerogel of the nitrobenzene gel of GLY.1. The fact that such remarkable properties arising from an easily accessible (salt formation) small molecule are due to supramolecular (non-covalent) interactions is quite intriguing and such easily synthesizable materials may be useful in stress-bearing and other applications. PMID:22628195

The United States generates 110 million t of coal ash annually. Approximately 70 million t of this coal ash is fly ash, of which 27% is recycled and the remaining 73% is landfilled. Disposal of such a huge quantity of ash poses a significant environmental problem. A new cementitious material has been developed, called alkali ash material (AAM), which is used to produce concrete for construction. AAM can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economic advantage. AAM contains 40-95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. AAM concrete has been tested for strength, durability, mechanical properties, and, most importantly, economic viability. AAM concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of ultimate in 1 d), high ultimate strengths (110 MPa or 16,000 psi in 1 d), excellent acid resistance, and freeze-thaw durability. AAM's resistance to chemical attack, such as sulfuric (H2SO4), nitric (HNO3), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. AAM is resistant to freeze-thaw attack based on ASTM C-666 specifications. Potential immediate applications of AAM are blocks, pipe, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products. PMID:12966995

This paper presents the results of a detailed theoretical investigation of the impact of non-LTE effects and of granulation inhomogeneities on the derived iron and oxygen abundances in the metal-poor halo subgiant HD140283. Our analysis is based on both the `classical' one-dimensional (1D) stellar atmosphere models and on the new generation of three-dimensional (3D) hydrodynamical models. We find that the non-LTE effects on the iron abundance derived from Fe {\\sc i} lines are very important, amounting to ${\\sim}0.9$ dex and to ${\\sim}0.6$ dex in the 3D and 1D cases, respectively. On the other hand, we find that non-LTE and 3D effects have to be taken into account for a reliable determination of the iron abundance from weak Fe {\\sc ii} lines, because the significant overexcitation of their upper levels in the granular regions tend to produce emission features. As a result such Fe {\\sc ii} lines are weaker than in LTE and the abundance correction amounts to ${\\sim}0.4$ dex for the 3D case. We derive also the ox...

In this paper, we explicate a method of quantum hydrodynamics (QHD) for the study of the quantum evolution of a system of polarized particles. Although we focused primarily on the two-dimensional (2D) physical systems, the method is valid for three-dimensional (3D) and one-dimensional (1D) systems too. The presented method is based upon the Schrödinger equation. Fundamental QHD equations for charged and neutral particles were derived from the many-particle microscopic Schrödinger equation. The fact that particles possess the electric dipole moment (EDM) was taken into account. The explicated QHD approach was used to study dispersion characteristics of various physical systems. We analyzed dispersion of waves in a two-dimensional ion and hole gas placed into an external electric field, which is orthogonal to the gas plane. Elementary excitations in a system of neutral polarized particles were studied for 1D, 2D, and 3D cases. The polarization dynamics in systems of both neutral and charged particles is shown to cause formation of a new type of waves as well as changes in the dispersion characteristics of already known waves. We also analyzed wave dispersion in 2D exciton systems, in 2D electron-ion plasma, and in 2D electron-hole plasma. Generation of waves in 3D-system neutral particles with EDM by means of the beam of electrons and neutral polarized particles is investigated.

Abstract The reaction of pyridine-2,3-dicarboxylic acid (2,3-pydcH2) with CuI and Ln2O3 under hydrothermal conditions generated a series of new one-, two-, and three-dimensional coordination polymers, namely, {[Cu3Ln2(2,3-pydc)6(H2O)12]12H2O}n [Ln = La(1), Nd(2)], {[Cu3Ln2(2,3-pydc)6(H2O)8]6H2O}n [Ln = Sm(3), Gd(4)], and {[Cu3Ln2(2,3-pydc)6(H2O)10]10H2O}n [Ln = Tb(5), Ho(6), Er(7), Yb(8), Lu(9)]. The results show that compounds 1 and 2 (type I structure) are 1-D Cu-4f rhombic lattice chains that are formed through assembly of two building block units Cu3(pydc)6 and Ln(H2O)6. Compounds 3-4 (type II structure) are 2-D layers that are constructed from building block units [Cu(pydc)2(H2O)2] 2-bridging adjacent 1-D rhombic lattice chains -[(Cu2(pydc)4)-(La(H2O)4)]n-. Complexes 5-9 (type III str...

We conduct a detailed test of a recently developed technique, CAPloc, in recovering source parameters from a few stations against results from a large broadband network. The method uses a library of 1D Green’s functions which are broken into segments and matched to waveform observations with adjustable timing shifts. These shifts can be established by calibration against a distribution of well-located earthquake and assembled in tomographic images for predicting various phase-delays. Synthetics generated from 2D cross-sections through these models indicates that 1D synthetic waveforms are sufficient in modeling but simply shifted in time for hard-rock sites. This simplification allows the source inversion for both mechanism and location to be easily obtained by grid search. We test one-station mechanisms for 160 events against the array for both PAS and GSC which have data since 1960. While one station solutions work well (about 90%), joint solutions produce more reliable and defensible results. Inverting for both mechanism and location also works well except for certain difficult paths that cross deep basins or propagate along mountain ridges.

This study evaluated the elimination of alkalinity need and excess sulfate generation of sulfur-based autotrophic denitrification process by stimulating simultaneous autotrophic and heterotrophic (mixotrophic) denitrification process in a column bioreactor by methanol supplementation. Also, denitrification performances of sulfur-based autotrophic and mixotrophic processes were compared. In autotrophic process, acidity produced by denitrifying sulfur-oxidizing bacteria was neutralized by the external NaHCO(3) supplementation. After stimulating mixotrophic denitrification process, the alkalinity need of the autotrophic process was satisfied by the alkalinity produced by heterotrophic denitrifiers. Decreasing and lastly eliminating the external alkalinity supplementation did not adversely affect the process performance. Complete denitrification of 75 mg L(-1) NO(3)-N under mixotrophic conditions at 4 h hydraulic retention time was achieved without external alkalinity supplementation and with effluent sulfate concentration lower than the drinking water guideline value of 250 mg L(-1). The denitrification rate of mixotrophic process (0.45 g NO(3)-N L(-1) d(-1)) was higher than that of autotrophic one (0.3 g NO(3)-N L(-1) d(-1)). Batch studies showed that the sulfur-based autotrophic nitrate reduction rate increased with increasing initial nitrate concentration and transient accumulation of nitrite was observed. PMID:22682897

The integral test of neutron cross sections for major shielding materials in JENDL-3 has been performed by analyzing various shielding benchmark experiments. For the fission-like neutron source problem, the following experiments are analyzed: (1) ORNL Broomstick experiments for oxygen, iron and sodium, (2) ASPIS deep penetration experiments for iron, (3) ORNL neutron transmission experiments for iron, stainless steel, sodium and graphite, (4) KfK leakage spectrum measurements from iron spheres, (5) RPI angular neutron spectrum measurements in a graphite block. For D-T neutron source problem, the following two experiments are analyzed: (6) LLNL leakage spectrum measurements from spheres of iron and graphite, and (7) JAERI-FNS angular neutron spectrum measurements on beryllium and graphite slabs. Analyses have been performed using the radiation transport codes: ANISN(1D Sn), DIAC(1D Sn), DOT3.5(2D Sn) and MCNP(3D point Monte Carlo). The group cross sections for Sn transport calculations are generated with the code systems PROF-GROUCH-G/B and RADHEAT-V4. The point-wise cross sections for MCNP are produced with NJOY. For comparison, the analyses with JENDL-2 and ENDF/B-IV have been also carried out. The calculations using JENDL-3 show overall agreement with the experimental data as well as those with ENDF/B-IV. Particularly, JENDL-3 gives better results than JENDL-2 and ENDF/B-IV for sodium. It has been concluded that JENDL-3 is very applicable for fission and fusion reactor shielding analyses. (author).

The achievement of high gain with inertial fusion requires the compression of hydrogen isotopes to high density and temperatures. High densities can be achieved most efficiently by isentropic compression. This requires relatively slow pressure pulses on the order of 10-20 nanoseconds; however, the pressure profile must have the appropriate time. We present 1-D numerical simulations that indicate such a pressure profile can be generated by using pulsed power driven z pinches. Although high compression is calculated, the initial temperature is too low for ignition. Ignition could be achieved by heating a small portion of this compressed fuel with a short (-10 ps) high power laser pulse as previously described. Our 1-D calculations indicate that the existing Z-accelerator could provide the driving current (-20 MA) necessary to compress fuel to roughly 1500 times solid density. At this density the required laser energy is approximately 10 kJ. Multidimensional effects such as the Rayleigh-Taylor were not addressed in this brief numerical study. These effects will undoubtedly lower fuel compression for a given chive current. Therefore it is necessary to perform z-pinch driven compression experiments. Finally, we present preliminary experimental data from the Z-accelerator indicating that current can be efficiently delivered to appropriately small loads (- 5 mm radius) and that VISAR can be used measure high pressure during isentropic compression.