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Sample records for sas seismic attenuation

  1. Anatomy of the TAMA SAS seismic attenuation system

    CERN Document Server

    Marka, S; Ando, M; Bertolini, A; Cella, G; DeSalvo, R; Fukushima, M; Iida, Y; Jacquier, F; Kawamura, S; Nishi, Y; Numata, K; Sannibale, V; Somiya, K; Takahashi, R; Tariq, H; Tsubono, K; Ugas, J; Viboud, N; Wang Chen Yang; Yamamoto, H; Yoda, T

    2002-01-01

    The TAMA SAS seismic attenuation system was developed to provide the extremely high level of seismic isolation required by the next generation of interferometric gravitational wave detectors to achieve the desired sensitivity at low frequencies. Our aim was to provide good performance at frequencies above approx 10 Hz, while utilizing only passive subsystems in the sensitive frequency band of the TAMA interferometric gravitational wave detectors. The only active feedback is relegated below 6 Hz and it is used to damp the rigid body resonances of the attenuation chain. Simulations, based on subsystem performance characterizations, indicate that the system can achieve rms mirror residual motion measured in a few tens of nanometres. We will give a brief overview of the subsystems and point out some of the characterization results, supporting our claims of achieved performance. SAS is a passive, UHV compatible and low cost system. It is likely that extremely sensitive experiments in other fields will also profit ...

  2. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  3. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-10-01

    In this report we will show the fundamental concepts of two different methods to compute seismic energy absorption. The first methods gives and absolute value of Q and is based on computation with minimum phase operators. The second method gives a relative energy loss compared to a background trend. This method is a rapid, qualitative indicator of anomalous absorption and can be combined with other attributes such as band limited acoustic impedance to indicate areas of likely gas saturation.

  4. Mechanisms of geometrical seismic attenuation

    Directory of Open Access Journals (Sweden)

    Igor B. Morozov

    2011-07-01

    Full Text Available In several recent reports, we have explained the frequency dependence of the apparent seismic quality-factor (Q observed in many studies according to the effects of geometrical attenuation, which was defined as the zero-frequency limit of the temporal attenuation coefficient. In particular, geometrical attenuation was found to be positive for most waves traveling within the lithosphere. Here, we present three theoretical models that illustrate the origin of this geometrical attenuation, and we investigate the causes of its preferential positive values. In addition, we discuss the physical basis and limitations of both the conventional and new attenuation models. For waves in media with slowly varying properties, geometrical attenuation is caused by variations in the wavefront curvature, which can be both positive (for defocusing and negative (for focusing. In media with velocity/density contrasts, incoherent reflectivity leads to geometrical-attenuation coefficients which are proportional to the mean squared reflectivity and are always positive. For «coherent» reflectivity, the geometrical attenuation is approximately zero, and the attenuation process can be described according to the concept of «scattering Q». However, the true meaning of this parameter is in describing the mean reflectivity within the medium, and not that of the traditional resonator quality factor known in mechanics. The general conclusion from these models is that non-zero and often positive levels of geometrical attenuation are common in realistic, heterogeneous media, both observationally and theoretically. When transformed into the conventional Q-factor form, this positive geometrical attenuation leads to Q values that quickly increase with frequency. These predictions show that the positive frequency-dependent Q observed in many datasets might represent artifacts of the transformations of the attenuation coefficients into Q.

  1. Seismic wave attenuation and velocity dispersion in UAE carbonates

    Science.gov (United States)

    Ogunsami, Abdulwaheed Remi

    Interpreting the seismic property of fluids in hydrocarbon reservoirs at low frequency scale has been a cherished goal of petroleum geophysics research for decades. Lately, there has been tremendous interest in understanding attenuation as a result of fluid flow in porous media. Although interesting, the emerging experimental and theoretical information still remain ambiguous and are practically not utilized for reasons not too obscure. Attenuation is frequency dependent and hard to measure in the laboratory at low frequency. This thesis describes and reports the results of an experimental study of low frequency attenuation and velocity dispersion on a selected carbonate reservoir samples in the United Arab Emirates (UAE). For the low frequency measurements, stress-strain method was used to measure the moduli from which the velocity is derived. Attenuation was measured as the phase difference between the applied stress and the strain. For the ultrasonic component, the pulse propagation method was employed. To study the fluid effect especially at reservoir in situ conditions, the measurements were made dry and saturated with liquid butane and brine at differential pressures of up to 5000 psi with pore pressure held constant at 500 psi. Similarly to what has been documented in the literatures for sandstone, attenuation of the bulk compressibility mode dominates the losses in these dry and somewhat partially saturated carbonate samples with butane and brine. Overall, the observed attenuation cannot be simply said to be frequency dependent within this low seismic band. While attenuation seems to be practically constant in the low frequency band for sample 3H, such conclusion cannot be made for sample 7H. For the velocities, significant dispersion is observed and Gassmann generally fails to match the measured velocities. Only the squirt model fairly fits the velocities, but not at all pressures. Although the observed dispersion is larger than Biot's prediction, the fact

  2. Forward- vs. Inverse Problems in Modeling Seismic Attenuation

    Science.gov (United States)

    Morozov, I. B.

    2015-12-01

    Seismic attenuation is an important property of wave propagation used in numerous applications. However, the attenuation is also a complex phenomenon, and it is important to differentiate between its two typical uses: 1) in forward problems, to model the amplitudes and spectral contents of waves required for hazard assessment and geotechnical engineering, and 2) in inverse problems, to determine the physical properties of the subsurface. In the forward-problem sense, the attenuation is successfully characterized in terms of empirical parameters of geometric spreading, radiation patterns, scattering amplitudes, t-star, alpha, kappa, or Q. Arguably, the predicted energy losses can be correct even if the underlying attenuation model is phenomenological and not sufficiently based on physics. An example of such phenomenological model is the viscoelasticity based on the correspondence principle and the Q-factor assigned to the material. By contrast, when used to invert for in situ material properties, models addressing the specific physics are required. In many studies (including in this session), a Q-factor is interpreted as a property of a point within the subsurface; however this property is only phenomenological and may be physically insufficient or inconsistent. For example, the bulk or shear Q at the same point can be different when evaluated from different wave modes. The cases of frequency-dependent Q are particularly prone of ambiguities such as trade-off with the assumed background geometric spreading. To rigorously characterize the in situ material properties responsible for seismic-wave attenuation, it is insufficient to only focus on the seismic energy loss. Mechanical models of the material need to be considered. Such models can be constructed by using Lagrangian mechanics. These models should likely contain no Q but will be based on parameters of microstructure such as heterogeneity, fractures, or fluids. I illustrate several such models based on viscosity

  3. 3-D seismic velocity and attenuation structures in the geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Nugraha, Andri Dian [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia); Syahputra, Ahmad [Geophyisical Engineering, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia); Fatkhan,; Sule, Rachmat [Applied Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jalan Ganesha No. 10 Bandung, 40132 (Indonesia)

    2013-09-09

    We conducted delay time tomography to determine 3-D seismic velocity structures (Vp, Vs, and Vp/Vs ratio) using micro-seismic events in the geothermal field. The P-and S-wave arrival times of these micro-seismic events have been used as input for the tomographic inversion. Our preliminary seismic velocity results show that the subsurface condition of geothermal field can be fairly delineated the characteristic of reservoir. We then extended our understanding of the subsurface physical properties through determining of attenuation structures (Qp, Qs, and Qs/Qp ratio) using micro-seismic waveform. We combined seismic velocities and attenuation structures to get much better interpretation of the reservoir characteristic. Our preliminary attanuation structures results show reservoir characterization can be more clearly by using the 3-D attenuation model of Qp, Qs, and Qs/Qp ratio combined with 3-D seismic velocity model of Vp, Vs, and Vp/Vs ratio.

  4. 3-D seismic velocity and attenuation structures in the geothermal field

    Science.gov (United States)

    Nugraha, Andri Dian; Syahputra, Ahmad; Fatkhan, Sule, Rachmat

    2013-09-01

    We conducted delay time tomography to determine 3-D seismic velocity structures (Vp, Vs, and Vp/Vs ratio) using micro-seismic events in the geothermal field. The P-and S-wave arrival times of these micro-seismic events have been used as input for the tomographic inversion. Our preliminary seismic velocity results show that the subsurface condition of geothermal field can be fairly delineated the characteristic of reservoir. We then extended our understanding of the subsurface physical properties through determining of attenuation structures (Qp, Qs, and Qs/Qp ratio) using micro-seismic waveform. We combined seismic velocities and attenuation structures to get much better interpretation of the reservoir characteristic. Our preliminary attanuation structures results show reservoir characterization can be more clearly by using the 3-D attenuation model of Qp, Qs, and Qs/Qp ratio combined with 3-D seismic velocity model of Vp, Vs, and Vp/Vs ratio.

  5. High-Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region

    Science.gov (United States)

    2010-03-20

    bottom). complicated tectonics . Lg appears to propagate well in the Arabian plate but is dramatically attenuated in the Lesser Caucasus. This may be...AFRL-RV-HA-TR-2010-1022 High-Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region Robert J. Mellors...Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region 5a. CONTRACT NUMBER FA8718-07-C-0007 5b. GRANT NUMBER 5c

  6. Seismic attenuation due to wave-induced flow

    Energy Technology Data Exchange (ETDEWEB)

    Pride, S.R.; Berryman, J.G.; Harris, J.M.

    2003-10-09

    Analytical expressions for three P-wave attenuation mechanisms in sedimentary rocks are given a unified theoretical framework. Two of the models concern wave-induced flow due to heterogeneity in the elastic moduli at mesoscopic scales (scales greater than grain sizes but smaller than wavelengths). In the first model, the heterogeneity is due to lithological variations (e.g., mixtures of sands and clays) with a single fluid saturating all the pores. In the second model, a single uniform lithology is saturated in mesoscopic ''patches'' by two immiscible fluids (e.g., air and water). In the third model, the heterogeneity is at ''microscopic'' grain scales (broken grain contacts and/or micro-cracks in the grains) and the associated fluid response corresponds to ''squirt flow''. The model of squirt flow derived here reduces to proper limits as any of the fluid bulk modulus, crack porosity, and/or frequency is reduced to zero. It is shown that squirt flow is incapable of explaining the measured level of loss (10{sup -2} < Q{sup -1} < 10{sup -1}) within the seismic band of frequencies (1 to 10{sup 4} Hz); however, either of the two mesoscopic scale models easily produce enough attenuation to explain the field data.

  7. Geophysical imaging of subsurface structures in volcanic area by seismic attenuation profiling

    Science.gov (United States)

    Tsuru, Tetsuro; No, Tetsuo; Fujie, Gou

    2017-01-01

    Geophysical imaging by using attenuation property of multichannel seismic reflection data was tested to map spatial variation of physical properties of rocks in a volcanic area. The study area is located around Miyakejima volcanic island, where an intensive earthquake swarm was observed associated with 2000 Miyakejima eruption. Seismic reflection survey was conducted five months after the swarm initiation in order to clarify crustal structure around the hypocenters of the swarm activity. However, the resulting seismic reflection profiles were unable to provide significant information of deep structures around the hypocenters. The authors newly applied a seismic attribute method that focused seismic attenuation instead of reflectivity to the volcanic area, and designed this paper to assess the applicability of this method to subsurface structural studies in poorly reflective volcanic areas. Resulting seismic attenuation profiles successfully figured out attenuation structures around the Miyakejima volcanic island. Interestingly, a remarkable high-attenuation zone was detected between Miyakejima and Kozushima islands, being well correlated with the hypocenter distribution of the earthquake swarm in 2000. The high-attenuation zone is interpreted as a fractured area that was developed by magma activity responsible for the earthquake swarms that have been repeatedly occurring there. The present study can be one example showing the applicability of seismic attenuation profiling in a volcanic area. [Figure not available: see fulltext. Caption: .

  8. Attenuation of high-frequency seismic waves in northeast India

    Science.gov (United States)

    Padhy, Simanchal; Subhadra, N.

    2010-04-01

    We studied attenuation of S and coda waves, their frequency and lapse time dependencies in northeast India in the frequency range of 1-24 Hz. We adopted theories of both single and multiple scattering to bandpass-filtered seismograms to fit coda envelopes to estimate Q for coda waves (QC) and Q for S-waves (QS) at five central frequencies of 1.5, 3, 6, 12 and 24 Hz. The selected data set consists of 182 seismograms recorded at ten seismic stations within epicentral distance of 22-300 km in the local magnitude range of 2.5-5.2. We found that with the increase in lapse time window from 40 to 60 s, Q0 (QC at 1 Hz) increases from 213 to 278, while the frequency dependent coefficient n decreases from 0.89 to 0.79. Both QC and QS increase with frequency. The average value of QS obtained by using coda normalization method for NE India has the power law form of (96.8 +/- 21.5)f(1.03+/-0.04) in 1-24 Hz. We adopted energy flux model (EFM) and diffusion model for the multiple scattered wave energy in three-dimensions. The results show that the contribution of multiple scattering dominates for longer lapse time close to or larger than mean free time of about 60 s. The estimates of QC are overestimated at longer lapse time by neglecting the effects of multiple scattering. Some discrepancies have been observed between the theoretical predictions and the observations, the difference could be due to the approximation of the uniform medium especially at large hypocentral distances. Increase in QC with lapse time can be explained as the result of the depth dependent attenuation properties and multiple scattering effect.

  9. Simultaneous seismic random noise attenuation and signal preservation by optimal spatiotemporal TFPF

    Science.gov (United States)

    Lin, Hongbo; Li, Yue; Ma, Haitao; Xu, Liping

    2016-05-01

    The time-frequency peak filtering (TFPF) algorithm has been successfully applied to seismic random noise attenuation. However, the time-frequency peak filtering with fixed-type spatiotemporal filtering trajectories fails to preserve reflected signals in seismic events which have complex geometric structure. An optimal spatiotemporal TFPF (OST-TFPF) is proposed here combining the Shapiro-Francia (S-F) statistic to reduce random noise and preserve seismic signals simultaneously. In the novel algorithm, the S-F statistic is first calculated for seismic data to detect seismic events based on the fact that the non-Gaussian seismic signals lead to smaller values of the S-F statistic comparing to seismic random noise which is general Gaussian. Then, optimal spatiotemporal filtering trajectory can be constructed based on the S-F statistic to coincide with the shape of each event. Finally, the optimal spatiotemporal TFPF de-noises seismic data along the optimal trajectories. Since the resampled signals along the trajectories matching the geometric structures of seismic events become more linear compared to signals in time, the OST-TFPF gives better signal estimation while attenuating random noise. Synthetic and field data examples demonstrate that the optimal spatiotemporal TFPF is effective in the denoising and signal-preserving of the seismic data with low signal-to-noise ratio. Moreover, the OST-TFPF also obtains good performance in preservation of seismic event with complex geometric structure.

  10. Reassigned time-frequency peak filtering for seismic random noise attenuation

    Science.gov (United States)

    Lin, H.; Li, Y.; Ma, H.

    2012-12-01

    Seismic noise attenuation for the aim of improving signal-to-noise ratio (S/N) plays an important role in seismic data processing for detailed description of oil and gas reservoirs. In particular, strong seismic random noise, which is unpredictable and incoherent in space and time, always degrades the qualities of seismic exploration and much more difficult to be suppressed than coherent noise, since only its statistical properties can be used. It is a common problem in random noise attenuation to keep the signal with minimized distortion. Multi-direction, multi-scale and time-varying methods can be considered as appropriate for tracking the signal characteristics varying in time. In particular, time-frequency based methods might better recover the local characteristics of the non-stationary seismic signal, which is important to produce a satisfactory random noise attenuation result. Time-frequency peak filtering(TFPF), which has already proved to be a powerful tool for Gaussian random noise attenuation in linear signal, can be alternative tool for seismic random noise attenuation. Indeed, seismic noise sometimes may have an asymmetric Wigner-Ville spectrum(WVS) and the seismic signal is nonlinear in time, which might induce amplitude attenuation and residual random noise in the results. This work reports the preliminary results from an improved TFPF method planned to obtain more accurate estimation of the seismic signal by increasing the signal concentration of the time-frequency distribution(TFD) during TFPF. At the beginning the improved reassignment TFPF(RTFPF) encoded the seismic trace as an instantaneous frequency (IF) of the analytic signal generated by frequency modulation. After that the smooth pseudo Wigner-Ville distribution(SPWVD) of the coded analytic signal was computed. The separate frequency window of the SPWVD helps to smooth away the random oscillations introduced by the WVS of seismic noise and nonlinear signal component in the pseudo Wigner

  11. Rock mass structure analysis based on seismic velocity and attenuation images

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Seismic traveltime, amplitude and pulse-width can be used to reconstruct seismic velocity and attenuation coefficient images for a rock mass. This study discusses the appearance differences of velocity and attenuation coefficient in the ore vein and rock mass in the images. The location of the rock vein and the characteristic of the rock mass are discussed according to the difference responses of velocity and attenuation from the ore vein and mixed rock vein, fracture and rock body. The effect and limitation of the seismic tomography method for investigating ore body and rock mass is suggested on the basis of a field test result. The special observation method in this study gives a good reference for obtaining full position and directional observation in seismic tomography.

  12. Seismic damage in historic town centres and attenuation criteria

    Directory of Open Access Journals (Sweden)

    A. Giuffrè

    1995-06-01

    Full Text Available The structural significance of the damage scenarios characteristic of VIII and IX degrees on the MKS macroseismic scale is discussed with reference to the seismic behaviour of the buildings which make up the urban fabric of a historic town or city. In an VIII degree scenario, damage is limited to structurally precarious situations, while a IX degree scenario involves seismic damage to external walls. Mechanical interpretation of these scenarios provides the basis for intervention strategies sufficiently well defined as to constitute a guide for seismic damage prevention programmes. VIII degree damage is prevented by identifying precarious situations. while IX degree damage requires systematic action. A proposal is put forward for the clarification of seismic regulations and the usefulness of evaluating future earthquakes in macroseismic terms with reference to the safety requirements of new buildings is discussed.

  13. Shear wave velocity, seismic attenuation, and thermal structure of the continental upper mantle

    Science.gov (United States)

    Artemieva, I.M.; Billien, M.; Leveque, J.-J.; Mooney, W.D.

    2004-01-01

    Seismic velocity and attenuation anomalies in the mantle are commonly interpreted in terms of temperature variations on the basis of laboratory studies of elastic and anelastic properties of rocks. In order to evaluate the relative contributions of thermal and non-thermal effects on anomalies of attenuation of seismic shear waves, QS-1, and seismic velocity, VS, we compare global maps of the thermal structure of the continental upper mantle with global QS-1 and Vs maps as determined from Rayleigh waves at periods between 40 and 150 S. We limit the comparison to three continental mantle depths (50, 100 and 150 km), where model resolution is relatively high. The available data set does not indicate that, at a global scale, seismic anomalies in the upper mantle are controlled solely by temperature variations. Continental maps have correlation coefficients of temperatures: most cratonic regions show high VS and QS and low T, while most active regions have seismic and thermal anomalies of the opposite sign. The strongest inverse correlation is found at a depth of 100 km, where the attenuation model is best resolved. Significantly, at this depth, the contours of near-zero QS anomalies approximately correspond to the 1000 ??C isotherm, in agreement with laboratory measurements that show a pronounced increase in seismic attenuation in upper mantle rocks at 1000-1100 ??C. East-west profiles of VS, QS and T where continental data coverage is best (50??N latitude for North America and 60??N latitude for Eurasia) further demonstrate that temperature plays a dominant, but non-unique, role in determining the value of lithospheric VS and QS. At 100 km depth, where the resolution of seismic models is the highest, we compare observed seismic VS and QS with theoretical VST and QST values, respectively, that are calculated solely from temperature anomalies and constrained by experimental data on temperature dependencies of velocity and attenuation. This comparison shows that

  14. P- and S-wave seismic attenuation for deep natural gas exploration and development

    Energy Technology Data Exchange (ETDEWEB)

    Walls, Joel [Rock Solid Images, Houston, TX (United States); Uden, Richard [Rock Solid Images, Houston, TX (United States); Singleton, Scott [Rock Solid Images, Houston, TX (United States); Shu, Rone [Rock Solid Images, Houston, TX (United States); Mavko, Gary [Stanford Univ., CA (United States)

    2005-04-12

    Using current methods, oil and gas in the subsurface cannot be reliably predicted from seismic data. This causes domestic oil and gas fields to go undiscovered and unexploited, thereby increasing the need to import energy.The general objective of this study was to demonstrate a simple and effective methodology for estimating reservoir properties (gas saturation in particular, but also including lithology, net to gross ratios, and porosity) from seismic attenuation and other attributes using P- and S-waves. Phase I specific technical objectives: Develop Empirical or Theoretical Rock Physics Relations for Qp and Qs; Create P-wave and S-wave Synthetic Seismic Modeling Algorithms with Q; and, Compute P-wave and S-wave Q Attributes from Multi-component Seismic Data. All objectives defined in the Phase I proposal were accomplished. During the course of this project, a new class of seismic analysis was developed based on compressional and shear wave inelastic rock properties (attenuation). This method provides a better link between seismic data and the presence of hydrocarbons. The technique employs both P and S-wave data to better discriminate between attenuation due to hydrocarbons versus energy loss due to other factors such as scattering and geometric spreading. It was demonstrated that P and S attenuation can be computed from well log data and used to generate synthetic seismograms. Rock physics models for P and S attenuation were tested on a well from the Gulf of Mexico. The P- and S-wave Q attributes were computed on multi-component 2D seismic data intersecting this well. These methods generated reasonable results, and most importantly, the Q attributes indicated gas saturation.

  15. Crustal Seismic Attenuation in Germany Measured with Acoustic Radiative Transfer Theory

    Science.gov (United States)

    Gaebler, Peter J.; Eulenfeld, Tom; Wegler, Ulrich

    2017-04-01

    This work is carried out in the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty a verification regime was introduced to detect, locate and characterize nuclear explosion testings. The study of seismology can provide essential information in the form of broadband waveform recordings for the identification and verification of these critical events. A profound knowledge of the Earth's subsurface between source and receiver is required for a detailed description of the seismic wave field. In addition to underground parameters such as seismic velocity or anisotropy, information about seismic attenuation values of the medium are required. Goal of this study is the creation of a comprehensive model of crustal seismic attenuation in Germany and adjacent areas. Over 20 years of earthquake data from the German Central Seismological Observatory data archive is used to estimate the spatial dependent distribution of seismic intrinsic and scattering attenuation of S-waves for frequencies between 0.5 and 20 Hz. The attenuation models are estimated by fitting synthetic seismogram envelopes calculated with acoustic radiative transfer theory to observed seismogram envelopes. This theory describes the propagation of seismic S-energy under the assumption of multiple isotropic scattering, the crustal structure of the scattering medium is hereby represented by a half-space model. We present preliminary results of the spatial distribution of intrinsic attenuation represented by the absorption path length, as well as of scattering attenuation in terms of the mean free path and compare the outcomes to results from previous studies. Furthermore catalog magnitudes are compared to moment magnitudes estimated during the inversion process. Additionally site amplification factors of the stations are presented.

  16. Seismic attenuation of the inner core: Viscoelastic or stratigraphic?

    Science.gov (United States)

    Cormier, V.F.; Xu, L.; Choy, G.L.

    1998-01-01

    Broadband velocity waveforms of PKIKP in the distance range 150??to 180??are inverted for inner core attenuation. A mean Q?? of 244 is determined at 1 Hz from 8 polar and 9 equatorial paths. The scatter in measured Q-1 exceeds individual error estimates, suggesting significant variation in attenuation with path. These results are interpreted by (1) viscoelasticity, in which the relaxation spectrum has a low-frequency corner near or slightly above the frequency band of short-period body waves, and by (2) stratigraphic (scattering) attenuation, in which attenuation and pulse broadening are caused by the interference of scattered multiples in a velocity structure having rapid fluctuations along a PKIKP path. In the scattering interpretation, PKIKP attenuation is only weakly affected by the intrinsic shear attenuation measured in the free-oscillation band. Instead, its frequency dependence, path variations, and fluctuations are all explained by scattering attenuation in a heterogeneous fabric resulting from solidification texturing of intrinsically anisotropic iron. The requisite fabric may consist of either single or ordered groups of crystals with P velocity differences of at least 5% and as much as 12% between two crystallographic axes at scale lengths of 0.5 to 2 km in the direction parallel to the axis of rotation and longer in the cylindrically radial direction, perpendicular to the axis of rotation.Broadband velocity waveforms of PKIKP in the distance range 150?? to 180?? are inverted for inner core attenuation. A mean Q?? of 244 is determined at 1 Hz from 8 polar and 9 equatorial paths. The scatter in the measured Q-1 exceeds individual error estimates, indicating significant variation in attenuation with path. The results are interpreted by viscoelasticity and stratigraphic (scattering) attenuation.

  17. Estimation of compressional seismic wave attenuation of carbonate rocks in Abu Dhabi, United Arab Emirates

    Science.gov (United States)

    Bouchaala, Fateh; Ali, Mohammed Y.; Farid, Asam

    2014-07-01

    The subsurface geology of Abu Dhabi in the United Arab Emirates is primarily composed of carbonate rocks. Such media are known to be highly heterogeneous. Very few studies have attempted to estimate attenuation in carbonate rocks. In Abu Dhabi no attenuation profile has been published. This study provides the first seismic wave attenuation profiles in Abu Dhabi using dense array of VSP data. We estimated three attenuation profiles: the apparent, the scattering, and the intrinsic attenuations. The apparent attenuation profile was computed using amplitude decay and spectral-ratio methods. The scattering attenuation profile was estimated using a generalized reflection-transmission matrix forward model. It is usually estimated from the sonic log, but to be more consistent with the apparent attenuation, we succeeded in this paper to estimate it from the VSP data. We subtracted the scattering attenuation from the apparent attenuation to deduce the intrinsic attenuation. The results of the study indicate that the scattering attenuation is significant compared to the published studies that are mainly based on clastic rocks. The high scattering attenuation can reach up to 0.02. It can be explained by the strong heterogeneity of the carbonate rocks. This study demonstrates that the Simsima and Rus Formations have considerable scattering and intrinsic attenuations. These formations are considered aquifers in Abu Dhabi; we therefore interpreted this high intrinsic attenuation zones to be due to the heterogeneity and to the fluids contained in these formations. The Umm-Er-Radhuma Formation is a more homogenous formation with limited aquifer potential. Hence, scattering and intrinsic attenuations of the Umm-Er-Radhuma Formation are low.

  18. Seismic attenuation in partially saturated Berea sandstone submitted to a range of confining pressures

    Science.gov (United States)

    Chapman, Samuel; Tisato, Nicola; Quintal, Beatriz; Holliger, Klaus

    2016-03-01

    Using the forced oscillation method, we measure the extensional-mode attenuation and Young's modulus of a Berea sandstone sample at seismic frequencies (0.5-50 Hz) for varying levels of water saturation (~0-100%) and confining pressures (2-25 MPa). Attenuation is negligible for dry conditions and saturation levels <80%. For saturation levels between ~91% and ~100%, attenuation is significant and frequency dependent in the form of distinct bell-shaped curves having their maxima between 1 and 20 Hz. Increasing saturation causes an increase of the overall attenuation magnitude and a shift of its peak to lower frequencies. On the other hand, increasing the confining pressure causes a reduction in the attenuation magnitude and a shift of its peak to higher frequencies. For saturation levels above ~98%, the fluid pressure increases with increasing confining pressure. When the fluid pressure is high enough to ensure full water saturation of the sample, attenuation becomes negligible. A second series of comparable experiments reproduces these results satisfactorily. Based on a qualitative analysis of the data, the frequency-dependent attenuation meets the theoretical predictions of mesoscopic wave-induced fluid flow (WIFF) in response to a heterogeneous water distribution in the pore space, so-called patchy saturation. These results show that mesoscopic WIFF can be an important source of seismic attenuation at reservoir conditions.

  19. Seismic attenuation tomography in frequency domain and its application to engineering

    Institute of Scientific and Technical Information of China (English)

    赵永贵[1; 李勤[2; 郭鸿[3; 靳洪晓[4; 王超凡[5

    2000-01-01

    Seismic tomography is a new geophysical technique being developed to meet the needs of mining and engineering projects. Attenuation tomography, as one kind of seismic tomography technique, is a powerful prospecting tool for determining structure defaults such as fault, broken zone, and hidden voids, but it has been little discussed up to now. Its principle and applications are presented in detail. Attenuation tomography technology includes the following main points. First, on the basis of spectrum analysis to each seismic record, geometric correction is conducted, then common source parameters are introduced into common shot records in order to keep absorption effect of the geological media separate from source spectrum influence. Finally, an equation set is obtained which consists of absorption coefficients, common source parameters and energy field data observed. This technique can be employed together with velocity tomography to provide more evidence for engineering and geological diagnosis. Its appl

  20. Seismic attenuation tomography in frequency domain and its application to engineering

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Seismic tomography is a new geophysical technique being developed to meet the needs of mining and engineering projects. Attenuation tomography, as one kind of seismic tomography technique, is a powerful prospecting tool for determining structure defaults such as fault, broken zone, and hidden voids, but it has been little discussed up to now. Its principle and applications are presented in detail. Attenuation tomography technology includes the following main points. First, on the basis of spectrum analysis to each seismic record, geometric correction is conducted, then common source parameters are introduced into common shot records in order to keep absorption effect of the geological media separate from source spectrum influence. Finally, an equation set is obtained which consists of absorption coefficients, common source parameters and energy field data observed. This technique can be employed together with velocity tomography to provide more evidence for engineering and geological diagnosis. Its applications to exploration of mineral and engineering have led to satisfactory results.

  1. Estimation of seismic attenuation in carbonate rocks using three different methods: Application on VSP data from Abu Dhabi oilfield

    Science.gov (United States)

    Bouchaala, F.; Ali, M. Y.; Matsushima, J.

    2016-06-01

    In this study a relationship between the seismic wavelength and the scale of heterogeneity in the propagating medium has been examined. The relationship estimates the size of heterogeneity that significantly affects the wave propagation at a specific frequency, and enables a decrease in the calculation time of wave scattering estimation. The relationship was applied in analyzing synthetic and Vertical Seismic Profiling (VSP) data obtained from an onshore oilfield in the Emirate of Abu Dhabi, United Arab Emirates. Prior to estimation of the attenuation, a robust processing workflow was applied to both synthetic and recorded data to increase the Signal-to-Noise Ratio (SNR). Two conventional methods of spectral ratio and centroid frequency shift methods were applied to estimate the attenuation from the extracted seismic waveforms in addition to a new method based on seismic interferometry. The attenuation profiles derived from the three approaches demonstrated similar variation, however the interferometry method resulted in greater depth resolution, differences in attenuation magnitude. Furthermore, the attenuation profiles revealed significant contribution of scattering on seismic wave attenuation. The results obtained from the seismic interferometry method revealed estimated scattering attenuation ranges from 0 to 0.1 and estimated intrinsic attenuation can reach 0.2. The subsurface of the studied zones is known to be highly porous and permeable, which suggest that the mechanism of the intrinsic attenuation is probably the interactions between pore fluids and solids.

  2. Fast dictionary learning for noise attenuation of multidimensional seismic data

    Science.gov (United States)

    Chen, Yangkang

    2017-04-01

    The K-SVD algorithm has been successfully utilized for adaptively learning the sparse dictionary in 2-D seismic denoising. Because of the high computational cost of many singular value decompositions (SVDs) in the K-SVD algorithm, it is not applicable in practical situations, especially in 3-D or 5-D problems. In this paper, I extend the dictionary learning based denoising approach from 2-D to 3-D. To address the computational efficiency problem in K-SVD, I propose a fast dictionary learning approach based on the sequential generalized K-means (SGK) algorithm for denoising multidimensional seismic data. The SGK algorithm updates each dictionary atom by taking an arithmetic average of several training signals instead of calculating an SVD as used in K-SVD algorithm. I summarize the sparse dictionary learning algorithm using K-SVD, and introduce SGK algorithm together with its detailed mathematical implications. 3-D synthetic, 2-D and 3-D field data examples are used to demonstrate the performance of both K-SVD and SGK algorithms. It has been shown that SGK algorithm can significantly increase the computational efficiency while only slightly degrading the denoising performance.

  3. Fast dictionary learning for noise attenuation of multidimensional seismic data

    Science.gov (United States)

    Chen, Yangkang

    2017-01-01

    The K-SVD algorithm has been successfully utilized for adaptively learning the sparse dictionary in 2D seismic denoising. Because of the high computational cost of many SVDs in the K-SVD algorithm, it is not applicable in practical situations, especially in 3D or 5D problems. In this paper, I extend the dictionary learning based denoising approach from 2D to 3D. To address the computational efficiency problem in K-SVD, I propose a fast dictionary learning approach based on the sequential generalized K-means (SGK) algorithm for denoising multidimensional seismic data. The SGK algorithm updates each dictionary atom by taking an arithmetic average of several training signals instead of calculating a SVD as used in K-SVD algorithm. I summarize the sparse dictionary learning algorithm using K-SVD, and introduce SGK algorithm together with its detailed mathematical implications. 3D synthetic, 2D and 3D field data examples are used to demonstrate the performance of both K-SVD and SGK algorithms. It has been shown that SGK algorithm can significantly increase the computational efficiency while only slightly degrading the denoising performance.

  4. Separating the effects of intrinsic and scattering seismic attenuation in Southern Taiwan

    Science.gov (United States)

    Chi, Tsung-Chih; Ou, Gwo-Bin; Huang, Bor-Shouh

    2016-04-01

    During seismic waves propagate in the medium, the energy will disperse because of geological complexity. In general, the traveling energy can be involved in the conversion of elastic energy to anelastic processes (intrinsic absorption) and the scattering from heterogeneities (scattering attenuation) in the lithosphere. Shown in seismic waves at high frequencies degree of coda content will display the geological structure characteristics in the region. To estimate the energy redistribution in the propagation pool is an important problem in seismology and in engineering. In this study, we use the energy flux model developed by Frankel and Wennerberg (1987) to separate the effects of intrinsic and scattering attenuation. The analyzed seismic coda waves begin at least twice the direct S-wave travel time form the local events recorded by the Taiwan Strong Motion Network in southern Taiwan. The data are filted with center frequencies at 1.0 Hz, 3.0 Hz, 5.0 Hz and 10.0 Hz by using the Butterworth filter. We hope the result can help us better understand the physical mechanisms of seismic attenuation in the lithosphere and explain the high-frequency seismograms.

  5. Imaging fluid-related subduction processes beneath Central Java (Indonesia) using seismic attenuation tomography

    Science.gov (United States)

    Bohm, Mirjam; Haberland, Christian; Asch, Günter

    2013-04-01

    We use local earthquake data observed by the amphibious, temporary seismic MERAMEX array to derive spatial variations of seismic attenuation (Qp) in the crust and upper mantle beneath Central Java. The path-averaged attenuation values (t∗) of a high quality subset of 84 local earthquakes were calculated by a spectral inversion technique. These 1929 t∗-values inverted by a least-squares tomographic inversion yield the 3D distribution of the specific attenuation (Qp). Analysis of the model resolution matrix and synthetic recovery tests were used to investigate the confidence of the Qp-model. We notice a prominent zone of increased attenuation beneath and north of the modern volcanic arc at depths down to 15 km. Most of this anomaly seems to be related to the Eocene-Miocene Kendeng Basin (mainly in the eastern part of the study area). Enhanced attenuation is also found in the upper crust in the direct vicinity of recent volcanoes pointing towards zones of partial melts, presence of fluids and increased temperatures in the middle to upper crust. The middle and lower crust seems not to be associated with strong heating and the presence of melts throughout the arc. Enhanced attenuation above the subducting slab beneath the marine forearc seems to be due to the presence of fluids.

  6. Seismic coherent and random noise attenuation using the undecimated discrete wavelet transform method with WDGA technique

    Science.gov (United States)

    Goudarzi, Alireza; Riahi, Mohammad Ali

    2012-12-01

    One of the most crucial challenges in seismic data processing is the reduction of the noise in the data or improving the signal-to-noise ratio. In this study, the 1D undecimated discrete wavelet transform (UDWT) has been acquired to attenuate random noise and ground roll. Wavelet domain ground roll analysis (WDGA) is applied to find the ground roll energy in the wavelet domain. The WDGA will be a substitute method for thresholding in seismic data processing. To compare the effectiveness of the WDGA method, we apply the 1D double density discrete wavelet transform (DDDWT) using soft thresholding in the random noise reduction and ground roll attenuation processes. Seismic signals intersect with ground roll in the time and frequency domains. Random noise and ground roll have many undesirable effects on pre-stack seismic data, and result in an inaccurate velocity analysis for NMO correction. In this paper, the UDWT by using the WDGA technique and DDDWT (using the soft thresholding technique) and the regular Fourier based method as f-k transform will be used and compared for seismic denoising.

  7. Lateral variation of seismic attenuation in Sikkim Himalaya

    Science.gov (United States)

    Thirunavukarasu, Ajaay; Kumar, Ajay; Mitra, Supriyo

    2017-01-01

    We use data from local earthquakes (mb ≥ 3.0) recorded by the Sikkim broad-band seismograph network to study the frequency-dependent attenuation of the crust and uppermost mantle. These events have been relocated using body wave phase data from local and regional seismograms. The decay of coda amplitudes at a range of central frequencies (1 to 12 Hz) has been measured for 74 earthquake-receiver pairs. These measurements are combined to estimate the frequency-dependent coda Q of the form Q( f) = Q0 f η. The estimated Q0 values range from 80 to 200, with an average of 123 ± 29; and η ranges from 0.92 to 1.04, with an average of 0.98 ± 0.04. To study the lateral variation of Q0 and η, we regionalized the measured Q values by combining all the earthquake-receiver path measurements through a back projection algorithm. We consider a single back-scatter model for the coda waves with elliptical sampling and parametrize the sampled area using 0.2° square grids. A nine-point spatial smoothening (similar to spatial Gaussian filter) is applied to stabilize the inversion. This is done at every frequency to observe the spatial variation of Q( f) and subsequently combined to obtain η variations. Results of our study reveal that the Sikkim Himalaya is characterized by low Q0 (80-100) compared to the foreland basin to its south (150-200) and the Nepal Himalaya to its west (140-160). The low Q and high η in Sikkim Himalaya is attributed to extrinsic scattering attenuation from structural heterogeneity and active faults within the crust, and intrinsic attenuation due to anelasticity in the hotter lithosphere beneath the actively deforming mountain belt. Similar low Q and high η values had also been observed in northwest and Garhwal-Kumaun Himalaya.

  8. Detailed Study of Seismic Wave Attenuation in Carbonate Rocks: Application on Abu Dhabi Oil Fields

    Science.gov (United States)

    Bouchaala, F.; Ali, M. Y.; Matsushima, J.

    2015-12-01

    Seismic wave attenuation is a promising attribute for the petroleum exploration, thanks to its high sensitivity to physical properties of subsurface. It can be used to enhance the seismic imaging and improve the geophysical interpretation which is crucial for reservoir characterization. However getting an accurate attenuation profile is not an easy task, this is due to complex mechanism of this parameter, although that many studies were carried out to understand it. The degree of difficulty increases for the media composed of carbonate rocks, known to be highly heterogeneous and with complex lithology. That is why few attenuation studies were done successfully in carbonate rocks. The main objectives of this study are, Getting an accurate and high resolution attenuation profiles from several oil fields. The resolution is very important target for us, because many reservoirs in Abu Dhabi oil fields are tight.Separation between different modes of wave attenuation (scattering and intrinsic attenuations).Correlation between the attenuation profiles and other logs (Porosity, resistivity, oil saturation…), in order to establish a relationship which can be used to detect the reservoir properties from the attenuation profiles.Comparison of attenuation estimated from VSP and sonic waveforms. Provide spatial distribution of attenuation in Abu Dhabi oil fields.To reach these objectives we implemented a robust processing flow and new methodology to estimate the attenuation from the downgoing waves of the compressional VSP data and waveforms acquired from several wells drilled in Abu Dhabi. The subsurface geology of this area is primarily composed of carbonate rocks and it is known to be highly fractured which complicates more the situation, then we separated successfully the intrinsic attenuation from the scattering. The results show that the scattering is significant and cannot be ignored. We found also a very interesting correlation between the attenuation profiles and the

  9. Propagation simulation and attenuation law analysis of seismic wave in elastoplastic tunnel rock medium

    Institute of Scientific and Technical Information of China (English)

    ZHAO Tong-bin; LI Jian-gong; XIAO Ya-xun; CHENG Guo-qiang

    2007-01-01

    The energy caused by the dynamic impact in mining engineering forth release and spread by the way of seismic waves, monitoring is an effective way for forecasting mine dynamical disasters, such as rockburst and coal and gas outburst. Three-dimensional dynamic model was built to simulate the propagating progress of seismic waves in the elastoplastic tunnel rock and analyzed the propagating law of perturbation acceleration around tunnel, based on the finite element dynamic analysis software ANSYS/LS-DYNA.The simulation results indicate that: (1) The propagation attenuation of seismic wave is a negative index relationship; (2) The acceleration amplitude of seismic wave decays rapidly in near-field and decays slowly in far-field; (3) When the perturbation is generated in the dead ahead of tunnel, the acceleration of seismic wave become smaller and smaller away from the roadway-rib;(4) The elastic and plastic stress state of tunnel rock is also an important factor for propagation process of wave, the energy of seismic wave is mainly consumed for geometric spreading and plastic deformation in propagation in the elastoplastic medium model.

  10. Seismic Wave Attenuation in Fractured Reservoir: Application on Abu Dhabi Oil Fields.

    Science.gov (United States)

    Bouchaala, F.; Ali, M.; Matsushima, J.

    2016-12-01

    There is a close link between fractures network and fluids circulation so information about nature and geometry of fractures in the reservoir zone is benificial for the petroleum industry. However the immaturity of the methodology and the complication of fractures network in some reservoirs like those of Abu Dhabi oil fields, make getting such information challenging. Since several studies showed the close link between physical properties of the subsurface and seismic wave attenuation (eg. Müller et al. 2010), we use this parameter in this study to assess its potentiality on fractures detection and characterization, even though its use is not common for reservoir characterization and even less for fractures characterization. To get an accurate attenuation profiles, we use a robust methods recently developed to estimate accurately attenuation from Vertical Seismic Profiling (VSP) (Matsushima et al. 2016) and sonic waveforms (Suziki and Matsushima 2013) in the reservoir zones. The data were acquired from many wells located in offshore and onshore oil fields of Abu Dhabi region. The subsurface of this region is mainly composed of carbonate rocks, such media are known to be highly heterogeneous. Scattering and intrinsic attenuation profiles were compared to interpreted fractures by using Formation Micro-imager (FMI). The comparison shows a correlation between these two parameters and fractures characteristic, such as their density and dipping. We also performed Alford rotation on dipole data to estimate the attenuation from fast and slow shear waveforms. The anisotropy is proportional to the dispersion of the points plotted from the ratio between the intrinsic attenuation of fast and slow shear over the depth, from the line (Qslow /Qfast=1), which corresponds to the isotropic case. We noticed that the zones with low fractures density display less dispersion than those of high density. Even though our results show potentiality of the attenuation for fractured

  11. The attenuation of seismic intensity in the Etna region and comparison with other Italian volcanic districts

    Directory of Open Access Journals (Sweden)

    T. Tuvè

    2006-06-01

    Full Text Available A detailed analysis of the intensity attenuation in the Etna and other Italian volcanic districts, was performed using the most recent and complete intensity datasets. Attenuation laws were derived through empirical models fitting ?I (the difference between epicentral I0 and site Ix intensities average values versus hypocentral site distances by the least-square method. The huge amount of data available for the Etna area allowed us to elaborate bi-linear and logarithmic attenuation models, also taking source effects into account. Furthermore, the coefficients of the Grandori formulation have been re-calculated to verify the ones previously defined for seismic hazard purposes. Among the tested relationships, the logarithmic one is simple and fairly stable, so it was also adopted for the other volcanic Italian areas. The analysis showed different attenuation trends: on the one hand, Etna and Ischia show the highest decay of intensity (?I=4 in the first 20 km; on the contrary, the Aeolian Islands and Albani Hills present a slight intensity attenuation (?I=2 at 20 km from the hypocentre; finally, Vesuvius seems to have an intermediate behaviour between the two groups. The proposed regionalization gives a significantly better image of near-field damage in volcanic regions and is easily applicable to probabilistic seismic hazard analyses.

  12. Variation of Seismic Coda Wave Attenuation in the Garhwal Region, Northwestern Himalaya

    Science.gov (United States)

    Tripathi, Jayant N.; Singh, Priyamvada; Sharma, Mukat L.

    2012-01-01

    Seismic coda wave attenuation ( Q_{text{c}}^{ - 1} ) characteristics in the Garhwal region, northwestern Himalaya is studied using 113 short-period, vertical component seismic observations from local events with hypocentral distance less than 250 km and magnitude range between 1.0 to 4.0. They are located mainly in the vicinity of the Main Boundary Thrust (MBT) and the Main Central Thrust (MCT), which are well-defined tectonic discontinuities in the Himalayas. Coda wave attenuation ( Q_{text{c}}^{ - 1} ) is estimated using the single isotropic scattering method at central frequencies 1.5, 3, 5, 7, 9, 12, 16, 20, 24 and 28 Hz using several starting lapse times and coda window lengths for the analysis. Results show that the ( Q_{text{c}}^{ - 1} ) values are frequency dependent in the considered frequency range, and they fit the frequency power law ( Q_{text{c}}^{ - 1} left( f right) = Q0^{ - 1} f^{ - n} ). The Q 0 ( Q c at 1 Hz) estimates vary from about 50 for a 10 s lapse time and 10 s window length, to about 350 for a 60 s lapse time and 60 s window length combination. The exponent of the frequency dependence law, n ranges from 1.2 to 0.7; however, it is greater than 0.8, in general, which correlates well with the values obtained in other seismically and tectonically active and highly heterogeneous regions. The attenuation in the Garhwal region is found to be lower than the Q {c/-1} values obtained for other seismically active regions of the world; however, it is comparable to other regions of India. The spatial variation of coda attenuation indicates that the level of heterogeneity decreases with increasing depth. The variation of coda attenuation has been estimated for different lapse time and window length combinations to observe the effect with depth and it indicates that the upper lithosphere is more active seismically as compared to the lower lithosphere and the heterogeneity decreases with increasing depth.

  13. High-resolution seismic attenuation structures beneath Hokkaido corner, northeastern Japan

    Science.gov (United States)

    Kita, S.; Nakajima, J.; Okada, T.; Hasegawa, A.; Katsumata, K.; Asano, Y.; Uchida, N.

    2013-12-01

    1. Introduction In the Hokkaido corner, the Kuril fore-arc sliver collides with the northeastern Japan arc. Using data from the nationwide Kiban seismic network and a temporary seismic network, Kita et al. [2012] determined high-resolution 3D seismic velocity structure beneath this area for deeper understanding of the collision process of two fore-arcs. The results show that a broad low-V zone (crust material) anomalously descends into the mantle wedge at depths of 30-90 km in the west of the Hidaka main thrust. On the other hand, several high-velocity zones having velocities of mantle materials are distributed in the crust at depths of 10-35 km. These high-velocity zones are inclined eastward, being nearly parallel to each other. Two of the western boundaries of these high-V zones correspond to the fault planes of the 1970 Mj 6.7 Hidaka and the 1982 Mj 7.1 Urakawa-oki earthquakes, respectively. In this study, we merged waveform data from the Kiban-network and from a dense temporary seismic network [Katsumata et al., 2002], and estimated the seismic attenuation structure to compare with the seismic velocity images of Kita et al. [2012]. 2. Data and method We estimated corner frequency for each earthquake by the spectral ratio method using the coda waves [e.g. Mayeda et al., 2007]. Then, we simultaneously determined values of t* and the amplitude level at lower frequencies from the observed spectra after correcting for the source spectrum. Seismic attenuation (Q-1 value) structure was obtained, inverting t* values with the tomographic code of Zhao et al. [1992]. We adopted the geometry of the Pacific plate which was precisely estimated by Kita et al. [2010b]. The study region covers an area of 41-45N, 140.5-146E, and a depth range of 0-200 km. We obtained 131,958 t* from 6,186 events (M>2.5) that occurred during the period from Aug. 1999 to Dec. 2012. The number of stations used is 353. Horizontal and vertical grid nodes were set with spacing of 0.10-0.3 degree and

  14. Viscoelastic characteristics of low-frequency seismic wave attenuation in porous media

    Institute of Scientific and Technical Information of China (English)

    Ling Yun; Han Li-Guo; Zhang Yi-Ming

    2014-01-01

    Mesoscopic fluid flow is the major cause of wave attenuation and velocity dispersion at seismic frequencies in porous rocks. The Johnson model provides solutions for the frequency-dependent quality factor and phase velocity in partially saturated porous media with pore patches of arbitrary shapes. We use the Johnson model to derive approximations for the quality factor Q at the high and low frequency limit, and obtain the approximate equation for Qmin based on geophysical and geometric parameters. A more accurate equation for Qmin is obtained after correcting for the linear errors between the exact and approximate Q values. The complexity of the pore patch shape affects the maximum attenuation of Qmin and the transition frequency ftr;furthermore, the effect on ftr is stronger than that on Qmin. Numerical solutions to Biot’s equation are computationally intensive; thus, we build an equivalent viscoelastic model on the basis of the Zener model, which well approximates the wave attenuation and dispersion in porous rocks in the seismic band.

  15. SAS essentials mastering SAS for data analytics

    CERN Document Server

    Elliott, Alan C

    2015-01-01

    A step-by-step introduction to using SAS® statistical software as a foundational approach to data analysis and interpretation Presenting a straightforward introduction from the ground up, SAS® Essentials: Mastering SAS for Data Analytics, Second Edition illustrates SAS using hands-on learning techniques and numerous real-world examples. Keeping different experience levels in mind, the highly-qualified author team has developed the book over 20 years of teaching introductory SAS courses. Divided into two sections, the first part of the book provides an introduction to data manipulation, st

  16. A data-dependent Fourier filter based on image segmentation for random seismic noise attenuation

    Science.gov (United States)

    Zhou, JiaXiong; Lu, Wenkai; He, Jianwei; Liu, Bing; Ren, Tin

    2015-03-01

    In this paper, we propose a data-dependent Fourier filter (DDFF) based on image segmentation for random seismic noise attenuation. In the proposed method, the original seismic data is divided into some overlapped small blocks. For each block, a local Fourier filter is designed automatically in two steps. At first, a binary mask is obtained by segmenting the Fourier amplitude spectra (FAS) of this block. The histogram of the FAS is used to get the threshold for the FAS segmentation. Secondly, an average filter is applied on the binary mask to get the tapered Fourier filter. In the proposed method, the DDFFs for all blocks are compact and time-space variant. After all blocks are processed, they are merged together to form the filtered result. We illustrate our method by a 2D synthetic seismic data, and give a comparison with the coherent event extraction method in Fourier domain. At last, a real 3D seismic data example demonstrates that the proposed method obtains some promising results.

  17. Effects of fracture contact areas on seismic attenuation due to wave-induced fluid flow

    Science.gov (United States)

    Germán Rubino, J.; Müller, Tobias M.; Milani, Marco; Holliger, Klaus

    2014-05-01

    Wave-induced fluid flow (WIFF) between fractures and the embedding matrix is considered to be a predominant seismic attenuation mechanism in fractured rocks. That is, due to the strong compressibility contrast between fractures and embedding matrix, seismic waves induce strong fluid pressure gradients, followed by local fluid flow between such regions, which in turn produces significant energy dissipation. Natural fractures can be conceptualized as two surfaces in partial contact, containing very soft and highly permeable material in the inner region. It is known that the characteristics of the fracture contact areas control the mechanical properties of the rock sample, since as the contact area increases, the fracture becomes stiffer. Correspondingly, the detailed characteristics of the contact area of fractures are expected to play a major role in WIFF-related attenuation. To study this topic, we consider a simple model consisting of a horizontal fracture located at the center of a porous rock sample and represented by a number of rectangular cracks of constant height separated by contact areas. The cracks are modelled as highly compliant, porous, and permeable heterogeneities, which are hydraulically connected to the background material. We include a number of rectangular regions of background material separating the cracks, which represent the presence of contact areas of the fracture. In order to estimate the WIFF effects, we apply numerical oscillatory relaxation tests based on the quasi-static poro-elastic equations. The equivalent undrained, complex plane-wave modulus, which allows to estimate seismic attenuation and velocity dispersion for the vertical direction of propagation, is expressed in terms of the imposed displacement and the resulting average vertical stress at the top boundary. In order to explore the effects of the presence of fracture contact areas on WIFF effects, we perform an exhaustive sensitivity analysis considering different

  18. Trade-off of Elastic Structure and Q in Interpretations of Seismic Attenuation

    Science.gov (United States)

    Deng, Wubing; Morozov, Igor B.

    2017-06-01

    The quality factor Q is an important phenomenological parameter measured from seismic or laboratory seismic data and representing wave-energy dissipation rate. However, depending on the types of measurements and models or assumptions about the elastic structure, several types of Qs exist, such as intrinsic and scattering Qs, coda Q, and apparent Qs observed from wavefield fluctuations. We consider three general types of elastic structures that are commonly encountered in seismology: (1) shapes and dimensions of rock specimens in laboratory studies, (2) geometric spreading or scattering in body-, surface- and coda-wave studies, and (3) reflectivity on fine layering in reflection seismic studies. For each of these types, the measured Q strongly trades off with the (inherently limited) knowledge about the respective elastic structure. For the third of the above types, the trade-off is examined quantitatively in this paper. For a layered sequence of reflectors (e.g., an oil or gas reservoir or a hydrothermal zone), reflection amplitudes and phases vary with frequency, which is analogous to a reflection from a contrast in attenuation. We demonstrate a quantitative equivalence between phase-shifted reflections from anelastic zones and reflections from elastic layering. Reflections from the top of an elastic layer followed by weaker reflections from its bottom can appear as resulting from a low Q within or above this layer. This apparent Q can be frequency-independent or -dependent, according to the pattern of thin layering. Due to the layering, the interpreted Q can be positive or negative, and it can depend on source-receiver offsets. Therefore, estimating Q values from frequency-dependent or phase-shifted reflection amplitudes always requires additional geologic or rock-physics constraints, such as sparseness and/or randomness of reflectors, the absence of attenuation in certain layers, or specific physical mechanisms of attenuation. Similar conclusions about the

  19. Physical mechanism of seismic attenuation in a two-phase medium%双相介质中地震波衰减的物理机制

    Institute of Scientific and Technical Information of China (English)

    李子顺

    2008-01-01

    High-frequency seismic attenuation is conventionally attributed to anelastic absorption. In this paper, I present three studies on high-frequency seismic attenuation and propose that the physical mechanism results from the interference of elastic microscopic multiple scattering waves. First, I propose a new theory on wave propagation in a two-phase medium which is based on the concept that the basic unit for wave propagation is a nano-mass point. As a result of the elasticity variations of pore fluid and rock framework, micro multiple scattering waves would emerge at the wavelength of the seismic waves passing through the two-phase medium and their interference and overlap would generate high-frequency seismic attenuation. Second, I present a study of the frequency response of seismic transmitted waves by modeling thin-layers with thicknesses no larger than pore diameters. Results indicate that high-frequency seismic waves attenuate slightly in a near-surface water zone but decay significantly in a near-surface gas zone. Third, I analyze the seismic attenuation characteristics in near-surface water and gas zones using dual-well shots in the Songliao Basin, and demonstrate that the high-frequency seismic waves attenuate slightly in water zones but in gas zones the 160-1600 Hz propagating waves decay significantly. The seismic attenuation characteristics from field observations coincide with the modeling results. Conclusions drawn from these studies theoretically support seismic attenuation recovery.

  20. Grain size evolution in the mantle and its effect on geodynamics, seismic velocities and attenuation

    Science.gov (United States)

    Dannberg, Juliane; Eilon, Zach; Gassmoeller, Rene; Moulik, Pritwiraj; Myhill, Robert; Faul, Ulrich; Asimow, Paul

    2015-04-01

    Dynamic models of Earth's convecting mantle usually implement flow laws with constant grain size, stress-independent viscosity and a limited treatment of variations associated with changes in mineral assemblage. These simplifications greatly reduce computational requirements but preclude effects such as shear localisation and transient changes in rheology associated with phase transitions, which have the potential to fundamentally change flow patterns in the mantle. Here we use the finite-element code ASPECT (Bangerth et al., 2013) to model grain size evolution and the interplay between grain size, stress and strain rate in the convecting mantle. We include the simultaneous and competing effects of dynamic recrystallisation resulting from work done by dislocation creep, grain growth in multiphase assemblages and recrystallisation at phase transitions. Grain size variations also affect seismic properties of mantle materials. We use several published formulations to relate intrinsic variables (P, T, and grain size) from our numerical models to seismic velocity (Vs) and attenuation (Q). Our calculations use thermodynamically self-consistent anharmonic elastic moduli determined for the mineral assemblages in the mantle using HeFESTo (Stixrude and Lithgow-Bertelloni, 2013). We investigate the effect of realistically heterogeneous grain sizes by computing body wave travel times, ray paths, and attenuation (t*) at different frequencies. We highlight the frequency-dependent sensitivity of seismic waves to grain size, which is important when interpreting Vs and Q observations in terms of mineral assemblage and temperature. Our models show that rapid metamorphic reactions in mantle upwellings and downwellings lead to high lateral viscosity contrasts, as a result of gradual grain size evolution. Positive feedback between grain size reduction and viscosity reduction results in shear localisation. As a result, the edges of thermal plumes have smaller grain sizes and lower

  1. SAS for dummies

    CERN Document Server

    McDaniel, Stephen

    2010-01-01

    The fun and easy way to learn to use this leading business intelligence tool Written by an author team who is directly involved with SAS, this easy-to-follow guide is fully updated for the latest release of SAS and covers just what you need to put this popular software to work in your business. SAS allows any business or enterprise to improve data delivery, analysis, reporting, movement across a company, data mining, forecasting, statistical analysis, and more. SAS For Dummies, 2nd Edition  gives you the necessary background on what SAS can do for you and explains how to use the Enterprise Gui

  2. Nyheder i SAS

    DEFF Research Database (Denmark)

    Milhøj, Anders

    2016-01-01

    I sommeren 2015 blev Analytical Produts opgraderet version 14.1, men stadig til Base SAS, version 9.4 sendt på markedet. Denne opdatering til nu Analytical Products 14.1 indeholder opdateringer af de analytiske programpakker indenfor statistik, økonometri, operationsanalyse etc. Disse opdateringer...... er nu løsrevet fra samtidige opdateringer af det samlede SAS-program. Desuden er den gratis SAS-applikation SAS-U opdateret; især er det bemærkelsesværdigt at der via SAS-U nu også stilles procedurer til rådighed for avancerede ikke-modelbaserede tidsrækkeanalyser....

  3. Matrixregning med SAS

    DEFF Research Database (Denmark)

    Andersen, Aage T.; Feilberg, Michael; Milhøj, Anders

    IML i SAS anvendes til matrixberegninger som en integreret del af SAS pakken. Den anvendes typisk til matrixberegninger i tilknytning til andre SAS applikationer, fx kan matricer let dannes ud fra datasæt i SAS. Desuden indeholder IML en række videregående matematiske og statistiske subroutiner......, der ikke findes andre steder i SAS.I bogen gennemgås matrixregning svarende til et indledende matematikkursus ved en højere læreanstalt. Den teoretiske gennemgang understøttes og demonstreres konsekvent med IML programmering, så fokus er på praktiske anvendelser af matricer....

  4. The Influence of Water on Seismic Wave Attenuation in the Upper Mantle

    Science.gov (United States)

    David, E. C.; Jackson, I.; Faul, U.; Berry, A.

    2014-12-01

    Trace amounts of water, present as protons structurally bound in olivine crystal defects, are inferred to significantly enhance the low-strain solid-state viscoelastic relaxation responsible for attenuation and dispersion of seismic waves in the upper mantle. This inferrence is supported by recent observation of water weakening at moderate compressive strains in synthetic, water-undersaturated aggregates (Faul et al., in preparation). In these fine-grained olivine polycrystals of Fo90 composition, doped with 0.02wt% TiO2, "water" is incorporated in the remarkably stable Ti-clinohumite defect. Such synthetic olivine specimens reproduce the infrared spectra of natural mantle olivines (Berry et al., 2005), and present the advantage of being melt-free and of low dislocation density. The water contents in such synthetic polycrystalline olivine aggregates, which can be quantitatively measured by Fourier Transform Infrared Spectroscopy (FTIR), range up to 90 ppm, and are thus representative of water-undersaturated conditions in the upper mantle. We will report here the outcome of torsional-oscillation tests,in which attenuation and shear modulus were measured at seismic frequencies (mHz-Hz) and various temperatures up to 1300C on Pt-encapsulated, Ti-doped olivine specimens, enclosed within a mild-steel jacket.

  5. Anatomy of a caldera: seismic velocity and attenuation models of the Campi Flegrei (Italy).

    Science.gov (United States)

    Calò, Marco; Tramelli, Anna

    2017-04-01

    Campi Flegrei is an active Caldera marked by strong vertical deformations of the soil called bradyseisms. The mechanisms proposed to explain this phenomenon are essentially three i) the presence of a shallow magmatic chamber that pushes the lid and consequently producing periodic variation of the soil level, ii) a thermic expansion of the geothermal aquifer due to the periodic increase of heat flux coming from a near magmatic chamber or deep fluids or iii) a combination of both phenomena. To solve the paradox, several models have been proposed to describe the nature and the geometry of the bodies responsible of the bradyseisms. Seismological tools allowed a rough description of the main features in terms of seismic velocities and attenuation parameters and till now were not able to resolve the smallest structures (<1.5-2km) located at shallow depth (0-4 km) and believed to be responsible of the soil deformations. Here we show Vp, Vp/Vs and Qp models carried out by applying an enhanced seismic tomography method combining the double difference approach (Zhang and Thurber, 2003) and the Weighted Average Method (Calò et al., 2009, Calò et al., 2011, 2013). The data used are the earthquakes recorded during the largest bradyseism crisis of the 80's. Our method allowed to image seismic velocity and attenuation structures with linear dimension of 0.5-1.2km, resulting in an improvement of the resolving power at least two times of the other published models (e.g. Priolo et al., 2012). The joint interpretation of seismic velocities and attenuation models allowed to discern small anomalous bodies at shallow depth (0.5-2.0 km) marked by relatively low Vp, high Vp/Vs ratio and low Qp values explainable with the presence of shallow geothermal water saturated reservoir from regions with low Vp, low Vp/Vs and low Qp possibly related to the gas saturated part of the reservoir. At deeper depth (2-3.5 km) bodies with high Vp and Vp/Vs and low Qp can be associated with magmatic

  6. Seismic Attenuation in the Parkfield area of the San Andreas Fault

    Science.gov (United States)

    Kelly, C. M.; Rietbrock, A.; Faulkner, D. R.

    2010-12-01

    Fault zone structure and rock properties at depth within the Parkfield area of San Andreas Fault are investigated through a seismic attenuation study. Attenuation is sensitive to the degree of fracturing, water saturation and other rock properties. The Parkfield area is of interest as it marks the boundary between the creeping area of the San Andreas Fault and an area which ruptured seismically in 1966 and again in 2004. It is also the area of the SAFOD drilling project. Previous studies of this area have suggested a complex picture of fault strands linking at depth and small bodies of high-velocity material (e.g. Li et al. 1997, Michael & Eberhart-Philips 1991). Various temporary and local seismic networks have been installed in the region and data from the PASO, PASO TRES and HRSN networks are used in this study. PASO data runs from 2001-2002 at sampling rate of 100sps. The PASO TRES data spans the time period 2004-2006 at 200sps. The HRSN network has been running since March 2001 to present with sampling at 250sps. Attenuation parameters (e.g. Q-values) are established using the spectral ratios technique. A window of 1.28 seconds around each event arrival is extracted together with a window of the same length within the noise directly preceding. Instrument corrected frequency spectra from both the event and the noise are smoothed in a logarithmically-scaled smoothing function. Only frequencies with a signal/noise ratio of 3 or above are used. The ratio between frequency spectra from event arrivals and synthetic frequency spectra of known seismic parameters is determined. A gridsearch method is used to fit the event corner frequency, searching within a range of corner frequencies implied from the reported event magnitude and assuming a stress drop of between 0.1 and 10MPa. A Brune source model is assumed (gamma=2, n=1) for the source spectra (Brune 1970). When the correct corner frequency is fitted, there should be a linear relationship between frequency and the

  7. A seismic attenuation zone below Popocatépetl volcano inferred from coda waves of local earthquakes

    OpenAIRE

    D. A. Novelo-Casanova; A. Martínez-Bringas

    2005-01-01

    Using a single scattering model, weighted averages of the quality factor Qc were estimated at 6 Hz for coda wave windows 25s after S-wave arrival at depths ranging from 2 to 10 km and magnitudes between 2 and 3. Considering Qc -1 as intrinsic attenuation, we find a zone of seismic wave attenuation between 6 and 8 km depth attributed to the presence of magma and partial melting of rock.

  8. SAS and Sata SSDs

    Science.gov (United States)

    Yasarapu, S.

    This chapter focuses on the different types of solid state drives. The chapter details the differences between consumer and enterprise solid state drives and also details the differences between SAS and SATA solid state drive and what lies ahead for SATA and SAS protocols for SSDs.

  9. Constraining attenuation with ambient noise correlations of reservoir scale seismic data

    Science.gov (United States)

    Weemstra, C.; Goertz, A.; Boschi, L.

    2011-12-01

    can then be applied to our data. We shall nevertheless evaluate the uniformity of the noise source distribution and attempt to obtain stable cross spectra at all available azimuths. This would allow us to evaluate lateral variations in scattering and intrinsic attenuation. At this scale, this represents a significant step forward in the application of the seismic ambient noise method.

  10. Attenuation of seismic waves and the universal rheological model of the Earth's mantle

    Science.gov (United States)

    Birger, B. I.

    2007-08-01

    Analysis of results of laboratory studies on creep of mantle rocks, data on seismic wave attenuation in the mantle, and rheological micromechanisms shows that the universal, i.e., relevant to all time scales, rheological model of the mantle can be represented as four rheological elements connected in series. These elements account for elasticity, diffusion rheology, high temperature dislocation rheology, and low temperature dislocation rheology. The diffusion rheology element is described in terms of a Newtonian viscous fluid. The high temperature dislocation rheology element is described by the rheological model previously proposed by the author. This model is a combination of a power-law non-Newtonian fluid model for stationary flows and the linear hereditary Andrade model for flows associated with small strains. The low temperature dislocation rheology element is described by the linear hereditary Lomnitz model.

  11. Numerical investigation of the hydro-mechanical contribution to seismic attenuation in damaged rocks

    Science.gov (United States)

    Pollmann, Nele; Jänicke, Ralf; Renner, Jörg; Steeb, Holger

    2016-04-01

    The investigation of hydro-mechanical processes, in particular the modeling of seismic waves in fractured porous media, is essential for the physical interpretation of data obtained from seismic exploration. Here, we specifically investigate attenuation processes in fluid-saturated porous rock containing fracture networks to identify effective hydro-mechanical properties by numerical simulation. The main purpose of this work is the characterization of the overall hydro-mechanical properties by computational homogenization. We determine an effective Skempton coefficient by investigating the fluid pressure and the solid displacement of the skeleton saturated by compressible fluids. Fracture networks are stochastically generated to mimic geological in-situ situations. The fractures are approximated as ellipses with aspect ratios up to 1/100, i.e. they constitute thin and long hydraulic conduits with high permeabilities. Simulations are designed on the material scale with and without conservation of fluid mass in the control volume. Using computational homogenization approaches, we define an effective Skempton coefficient. A range of fracture networks with different characteristic properties is studied for different varieties of fractures. On the material scale we find strongly heterogeneous pressure propagation in the fracture network and the surrounding rock, respectively. The pressure diffusion is much faster in the fracture network than in the matrix, rendering the macroscopic hydro-mechanical behavior strongly time dependent. The effective Skempton coefficient converges to an ensemble-specific instantaneous value and to 1 for long-time studies. The ultimate objective of our study is to evaluate whether constraints on the structure of fracture networks can be deduced from observations of attenuation and its frequency dependence.

  12. Quantifying Regional Body Wave Attenuation in a Seismic Prone Zone of Northeast India

    Science.gov (United States)

    Bora, Nilutpal; Biswas, Rajib

    2017-03-01

    We evaluated the body wave attenuation parameter in Kopili region of northeast India. Using the modified algorithm of coda normalization method, we delineated frequency-dependent attenuation for both P and S waves. Taking more than 300 seismograms as input, we comprehensively studied microearthquake spectra in the frequency range of 1.5-12 Hz. The estimated values of {Q}_{P}^{-1} and {Q}_{S}^{-1} show strong frequency dependence. Based on this, we formulated empirical relationships corresponding to {Q}_{P}^{-1} and {Q}_{S}^{-1} for the study region. The relationships emerge to be {Q}_{P}^{-1} = ( {23.8 ± 6} ) × 10^{-3} {f}^{{( {-1.2 ± 0.008} )}} and {Q}_{S}^{-1} = ( {10.2 ± 2} ) × 10^{-3} {f}^{{( {-1.3 ± 0.02} )}} , respectively. The ratio {Q}_{P}^{-1} /{Q}_{S}^{-1} is found to be larger than unity for the entire frequency band which implies profound seismic activity and macroscale heterogeneity prevailing in the region. The study may act as the building block towards determination of source parameter and hazard-related studies in the region.

  13. Apparent Attenuation and Dispersion Arising in Seismic Body-Wave Velocity Retrieval

    Science.gov (United States)

    Wirgin, Armand

    2016-07-01

    The fact that seismologists often make measurements, using natural seismic solicitations, of properties of the Earth on rather large scales (laterally and in terms of depth) has led to interrogations as to whether attenuation of body waves is dispersive and even significant. The present study, whose aim is to clarify these complicated issues, via a controlled thought measurement, concerns the retrieval of a single, real body wave velocity of a simple geophysical configuration (involving two homogeneous, isotropic, non-dissipative media, one occupying the layer, the other the substratum), from its simulated response to pulsed plane wave probe radiation. This inverse problem is solved, at all frequencies within the bandwidth of the pulse. Due to discordance between the models associated with the assumed and trial responses, the imaginary part of the retrieved velocity turns out to be non-nil even when both the layer and substratum are non-lossy, and, in fact, to be all the greater, the larger is the discordance. The reason for this cannot be due to intrinsic attenuation, scattering, or geometrical spreading since these phenomena are absent in the chosen thought experiment, but rather to uncertainty in the measurement model.

  14. Data analysis using SAS

    CERN Document Server

    Peng, Chao-Ying Joanne

    2008-01-01

    "Peng provides an excellent overview of data analysis using the powerful statistical software package SAS. This book is quite appropriate as a self-placed tutorial for researchers, as well as a textbook or supplemental workbook for data analysis courses such as statistics or research methods. Peng provides detailed coverage of SAS capabilities using step-by-step procedures and includes numerous comprehensive graphics and figures, as well as SAS printouts. Readers do not need a background in computer science or programming. Includes numerous examples in education, health sciences, and business.

  15. Refining the 3D seismic velocity and attenuation models for Katmai National Park, Alaska

    Science.gov (United States)

    Murphy, R. A.; Thurber, C. H.; Prejean, S. G.

    2009-12-01

    We invert data from approximately 4,000 local earthquakes occurring between September 2004 and August 2009 to determine the 3D P-wave velocity and P-wave attenuation structures in the Katmai volcanic region. Arrival information and waveforms for the study come from the Alaska Volcano Observatory’s permanent network of 20 seismometers in the area, which are predominantly single-component, short period instruments. The absolute and relative arrival times are used in a double-difference seismic tomography inversion to solve for an improved velocity model for the main volcanic centers. We use the resulting 3D velocity model to relocate all catalog earthquakes in Katmai between January 1996 and August 2009. Inversions for the quality factor Q are completed using a spectral decay approach to determine source parameters, t*, and site response with a nonlinear inversion. Using the final 3D velocity model to define the ray paths, t* values are then inverted to determine frequency-independent Q models. The final models developed through these inversions reveal a low velocity and low Q zone from the surface to ~7 km depth centered on the volcanic axis and extending ~25 km between Martin and Katmai volcanoes. The relocated hypocenters provide insight into the geometry of seismogenic structures in the area, revealing clustering of events into four distinct zones associated with Martin, Mageik, Trident, and Katmai. While the Martin, Mageik, and Katmai clusters are all at 3-4 km depth, the Trident cluster is slightly deeper at 4-6 km. Many new features are apparent within these clusters, including a strand of earthquakes trending NE-SW between the main Martin and Mageik clusters. Smaller linear features are also visible in the Katmai cluster along with a small migrating swarm which occurred NW of the Katmai caldera during mid-2006. Data from an array of 11 three-component broadband instruments currently deployed in the area between Mageik volcano and Katmai caldera will be

  16. SAS for dummies

    CERN Document Server

    McDaniel, Stephen

    2010-01-01

    The fun and easy way to learn to use this leading business intelligence tool Written by an author team who is directly involved with SAS, this easy-to-follow guide is fully updated for the latest release of SAS and covers just what you need to put this popular software to work in your business. SAS allows any business or enterprise to improve data delivery, analysis, reporting, movement across a company, data mining, forecasting, statistical analysis, and more. SAS For Dummies, 2nd Edition  gives you the necessary background on what SAS can do for you and explains how to use the Enterprise Guide. SAS provides statistical and data analysis tools to help you deal with all kinds of data: operational, financial, performance, and more Places special emphasis on Enterprise Guide and other analytical tools, covering all commonly used features Covers all commonly used features and shows you the practical applications you can put to work in your business Explores how to get various types of data into the software and...

  17. An energy-based approach to estimate seismic attenuation due to wave-induced fluid flow in heterogeneous poroelastic media

    Science.gov (United States)

    Solazzi, Santiago G.; Rubino, J. Germán; Müller, Tobias M.; Milani, Marco; Guarracino, Luis; Holliger, Klaus

    2016-11-01

    Wave-induced fluid flow (WIFF) due to the presence of mesoscopic heterogeneities is considered as one of the main seismic attenuation mechanisms in the shallower parts of the Earth's crust. For this reason, several models have been developed to quantify seismic attenuation in the presence of heterogeneities of varying complexity, ranging from periodically layered media to rocks containing fractures and highly irregular distributions of fluid patches. Most of these models are based on Biot's theory of poroelasticity and make use of the assumption that the upscaled counterpart of a heterogeneous poroelastic medium can be represented by a homogeneous viscoelastic solid. Under this dynamic-equivalent viscoelastic medium (DEVM) assumption, attenuation is quantified in terms of the ratio of the imaginary and real parts of a frequency-dependent, complex-valued viscoelastic modulus. Laboratory measurements on fluid-saturated rock samples also rely on this DEVM assumption when inferring attenuation from the phase shift between the applied stress and the resulting strain. However, whether it is correct to use an effective viscoelastic medium to represent the attenuation arising from WIFF at mesoscopic scales in heterogeneous poroelastic media remains largely unexplored. In this work, we present an alternative approach to estimate seismic attenuation due to WIFF. It is fully rooted in the framework of poroelasticity and is based on the quantification of the dissipated power and stored strain energy resulting from numerical oscillatory relaxation tests. We employ this methodology to compare different definitions of the inverse quality factor for a set of pertinent scenarios, including patchy saturation and fractured rocks. This numerical analysis allows us to verify the correctness of the DEVM assumption in the presence of different kinds of heterogeneities. The proposed methodology has the key advantage of providing the local contributions of energy dissipation to the overall

  18. Seismicity and Attenuation Correlation Analysis in the Bucaramanga Nest (Colombia). A Test for the Brittle-Ductile Interaction Hypothesis

    Science.gov (United States)

    Tarela, E.; Pujades, L. G.; Ugalde, A.

    2008-12-01

    Technical advances are nowadays starting to provide data sets covering large enough time windows and allowing studying the time evolution of several seismic parameters with some perspective. We study here, at a local scale, the following items: 1) the time evolution of two of these parameters, the seismicity and the coda-wave-attenuation, 2) their relationship in order to test the brittle-ductile interaction hypothesis of the lithosphere-asthenosphere complex system, and 3) its possible use as a mid-term predictor. Seismicity represents the brittle zone stress state, while the one of the ductile zone is characterized by the attenuation of coda waves, which here is measured through coda-Q quality factor. According to the model, the time series will present a similar variation rate during the calm period of the cycle. About two years before a major earthquake takes place in the region, the stress state of both the brittle and the ductile parts of the lithosphere-asthenosphere system would change and the correlation between the two parameters would break down because of this uncoupling. So, a correlation analysis of the two time series would lead to a mid- term prediction. The method is applied in a region with a complex and deep seismicity; this is, the Nest of Bucaramanga (Colombia). The seismic catalogue and waveforms for the attenuation analysis are obtained from Ingeominas; the catalogue includes 13629 events with local magnitude ML>3, fulfilling the magnitude completeness conditions. The seismic attenuation data are obtained from waveforms that have been selected between more than 17000 short period vertical seismograms, recorded at Barichara station, which is located right over the seismic nest. Over 3600 of these waveforms fulfil the magnitude completeness conditions, happened at hypocentral distances smaller than 150km and give coda Q fitting values with correlation coefficients r2≥0.7 So, for the time evolution we were able to average over 50 values of Q0

  19. Sidste nyt fra SAS

    DEFF Research Database (Denmark)

    Milhøj, Anders

    2014-01-01

    I juli 2013 blev version 9.4 af SAS sendt på markedet. Denne release indeholdt ikke mange nye faciliteter indenfor statistik, økonometri, operationsanalyse etc, men alligevel er der vigtige aspekter at forholde sig til. Ved årsskiftet 2013/2014 er der siden kommet en opdatering af de analytiske...... programpakker for statistik, økonometri, operationsanalyse etc uden en samtidig opdatering af det samlede SAS-program. Denne opdatering kaldes Analytical Products 13.1 og er en væsentlig opdatering fra version 12, der i første version kom i august 2012....

  20. Nyheder i SAS

    DEFF Research Database (Denmark)

    Milhøj, Anders

    2015-01-01

    I juli 2013 blev version 9.4 af SAS sendt på markedet. Denne release indeholdt ikke i sig selv mange nye faciliteter indenfor statistik, økonometri, operations-analyse etc, men alligevel er der vigtige aspekter at forholde sig til. Ved årsskiftet 2013/2014 kom opdateringen Analytical Products 13.......1 af de analytiske programpakker for statistik, økonometri, operationsanalyse etc uden en samtidig opdatering af det samlede SAS-program. Denne opdatering er siden fulgt op med en yderligere opdatering 13.2 i august 2014....

  1. Seismic wave attenuation and dispersion due to wave-induced fluid flow in rocks with strong permeability fluctuations.

    Science.gov (United States)

    Germán Rubino, J; Monachesi, Leonardo B; Müller, Tobias M; Guarracino, Luis; Holliger, Klaus

    2013-12-01

    Oscillatory fluid movements in heterogeneous porous rocks induced by seismic waves cause dissipation of wave field energy. The resulting seismic signature depends not only on the rock compressibility distribution, but also on a statistically averaged permeability. This so-called equivalent seismic permeability does not, however, coincide with the respective equivalent flow permeability. While this issue has been analyzed for one-dimensional (1D) media, the corresponding two-dimensional (2D) and three-dimensional (3D) cases remain unexplored. In this work, this topic is analyzed for 2D random medium realizations having strong permeability fluctuations. With this objective, oscillatory compressibility simulations based on the quasi-static poroelasticity equations are performed. Numerical analysis shows that strong permeability fluctuations diminish the magnitude of attenuation and velocity dispersion due to fluid flow, while the frequency range where these effects are significant gets broader. By comparing the acoustic responses obtained using different permeability averages, it is also shown that at very low frequencies the equivalent seismic permeability is similar to the equivalent flow permeability, while for very high frequencies this parameter approaches the arithmetic average of the permeability field. These seemingly generic findings have potentially important implications with regard to the estimation of equivalent flow permeability from seismic data.

  2. Change in Seismic Attenuation of the Nojima Fault Zone Measured Using Spectral Ratios from Borehole Seismometers

    Science.gov (United States)

    Kano, Y.; Tadokoro, K.; Nishigami, K.; Mori, J.

    2006-12-01

    We measured the seismic attenuation of the rock mass surrounding the Nojima fault, Japan, by estimating the P-wave quality factor, Qp, using spectral ratios derived from a multi-depth (800 m and 1800 m) seismometer array. We detected an increase of Qp in 2003-2006 compared to 1999-2000. Following the 1995 Kobe earthquake, the project "Fault Zone Probe" drilled three boreholes to depths of 500 m, 800 m, 1800 m, in Toshima, along the southern part of the Nojima fault. The 1800-m borehole was reported to reach the fault surface. One seismometer (TOS1) was installed at the bottom of the 800-m borehole in 1996 and another (TOS2) at the bottom of 1800-m borehole in 1997. The sampling rate of the seismometers is 100 Hz. The slope of the spectral ratios for the two stations plotted on a linear-log plot is -π t^{*}, where t^{*} is the travel time divided by the Qp for the path difference between the stations. For the estimation of Qp, we used events recorded by both TOS1 and TOS2 for periods of 1999-2000 and 2003-2006. To improve the signal-to-noise ratio of the spectral ratios, we first calculated spectra ratios between TOS1 and TOS2 for each event and averaged the values over the earthquakes for each period. We used the events that occurred within 10 km from TOS2, and the numbers of events are 74 for 1999-2000 and 105 for 2003-2006. Magnitudes of the events range from M0.5 to M3.1. The average value of Qp for 1999-2000 increased significantly compared to 2003-2006. The attenuation of rock mass surrounding the fault in 2003-2006 is smaller than that in 1999-2000, which suggests that the fault zone became stiffer after the earthquake. At the Nojima fault, permeability measured by repeated pumping tests decreased with time from the Kobe earthquake, infering the closure of cracks and a fault healing process occurred The increase of Qp is another piece of evidence for the healing process of the Nojima fault zone. u.ac.jp/~kano/

  3. The Use of Ultrasonic Seismic Wave Attenuation (Q) for Better Subsurface Imaging, Energy Exploration, and Tracking of Sequestrated Carbon Dioxide

    Science.gov (United States)

    Delaney, D.; Purcell, C. C.; Mur, A. J.; Haljasmaa, I.; Soong, Y.; Harbert, W.

    2012-12-01

    Parameters related to seismic and ultrasonic elastic waves traveling through a porous rock material with compliant pores, cracks and isometric pores are subject to variations which are dependent on the physical properties of the rock such as density, porosity, permeability, frame work moduli, fluid moduli, micro structural variation, and effective pressure. Our goal is to understand these variations through experiments completed using Berea sandstone, rhyolites, coal, and carbonate samples. Understanding these lithologies are relevant to enhanced oil recovery, enhanced geothermal, and CO2 storage activities. Working in the COREFLOW laboratory at the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) we performed several experiments on these rock types with various different pore filling fluids, effective pressures, and temperatures. We measured P, S1 and S2 ultrasonic velocities using an New England Research (NER) Autolab 1500 device and calculated the lame parameters (Bulk modulus (K), Young's modulus (E), Lamè's first parameter (λ), Shear modulus (G), Poisson's ratio ( ), P-wave modulus (M)). Using an aluminum reference core and the P, S1, and S2 ultrasonic waveform data collected, we employed the spectral ratio method to estimate Q. This method uses the ratio of the amplitude-frequency spectrum (obtained via fast Fourier Transform and processed using Matlab) of the rock core compared with the amplitude-frequency spectrum of the aluminum reference core to calculate the quality factor (Q). The quality factor is a dimensionless value that represents the attenuation of a seismic wave as it travels through a rock. Seismic attenuation is dependent on wave velocity, the path length or time the wave is in the rock, and of course the physical properties of the rock through which the wave travels. Effective pressures used in our experiments varied between 0.01 MPa and 50 MPa and temperatures varied between 21 C to 80 C which

  4. Measurements of seismic wave attenuation for frequencies between 0.1 and 100 Hz in a Paterson Rig

    Science.gov (United States)

    Madonna, C.; Tisato, N.; Delle Piane, C.; Saenger, E. H.

    2012-04-01

    The study of wave attenuation in partially saturated porous rocks over a broad frequency range provides valuable information about reservoir fluid systems, which are inherently composed of multiple phase fluid. Following an original idea initiated by Luigi, we designed and set up a specific instrument, the Seismic Wave Attenuation Module (SWAM), to experimentally measure the bulk attenuation on partially saturated rocks at frequencies between 0.01 and 100 Hz, using natural rock samples under in situ conditions. We present its bench-top calibration, a series of data collected from different kind of rocks at different confing pressure and the numerical simulations, supporting the obtained results. We employ the sub-resonance test. Assuming that the rock behaves as a linear time invariant (LTI) system, the attenuation factor 1/Q (Q is the quality factor) is equal to the tangent of the phase shift between the stress and the strain signal. The new attenuation measurement equipment is calibrated in a gas apparatus (Paterson rig) using aluminum as elastic standard and Plexiglas as a viscoelastic standard. Measurements were performed on 25.4 mm diameter, 60 mm long samples. Berea sandstone samples with 20% porosity, and ~500 mD permeability have been measured at different saturation conditions. Attenuation measurements show dependence upon saturation. Moreover, measurements on two well-characterized shale samples have been performed. The two shales have significantly different quality factors; which result to be dependent on both the saturation state of the samples and the propagation direction of the oscillatory signal with respect to the sedimentary bedding. The attenuation coefficient parallel to bedding is less than that vertical to bedding. Thanks to Luigi's initiative and inspiration two generations of his Ph.D. students are now able to jointly present these new challenging experimental results.

  5. Scattering and anelastic attenuation of seismic energy in Northeast India using the multiple lapse time window analysis

    Science.gov (United States)

    Padhy, S.

    2010-12-01

    We investigated the intrinsic dissipation and scattering properties of the lithosphere beneath the northeast India by using the seismic waves recorded by a network of ten broadband stations in the region with hypocentral distances ranging from 31 to 200 km. First, we determined coda Q from the amplitude decay rate of the S-wave coda envelopes in five frequency bands from 1.5 to 24 Hz based on single scattering theory and QS by means of the coda normalization method. Assuming a frequency dependent power-law of the form , we found a low Q0 (Q0 India is seismically active and heterogeneous. Then we applied the multiple lapse time window (MLTW) analysis in the hypothesis of velocity and scattering coefficients constant with depth. We calculated the variation of integrated spectral energy with hypocentral distance for three consecutive lapse time windows (0-15, 15-30, 30-45 sec), starting from the onset of the S-wave arrival. The spectral energies over an octave bandwidth with central frequencies at 1.5, 3, 6, 12 and 24 Hz were calculated to obtain the frequency dependence of attenuation parameters. The results show that intrinsic absorption dominates over scattering in the attenuation process at high frequencies. However, in the hypothesis of uniform medium, the estimates of scattering attenuations obtained by MLTW analysis are overestimated. So the present results are correct to a first order approximation. To obtain more reliable and unbiased estimates of the attenuation parameters and their frequency dependences by considering the probable influence of crustal-mantel heterogeneities, we analyze the events by using the depth dependent MLTW method.

  6. Is it possible to infer the frequency-dependent seismic attenuation of fractured materials from high-strain creep tests?

    Science.gov (United States)

    mallet, celine; quintal, beatriz; caspari, eva; holliger, klaus

    2016-04-01

    The seismic and hydraulic characterization of fractured rocks is an important objective for reservoir development in general and the production of geothermal energy in particular. The attenuation of seismic waves in saturated fractured media is governed by local displacements of the fluid relative to the solid induced by the compressions and extensions associated with the passing wavefield. This phenomenon is generally referred to as wave-induced fluid flow (WIFF). Recent evidence suggests that this energy dissipation mechanism is sensitive to the interconnectivity of the fractures, which offers the perspective of linking seismic observations to the hydraulic properties of fractured rocks. Here, we consider the results of laboratory experiments, which are referred to as creep tests. Such tests consist of applying a constant stress to a water-saturated thermally cracked glass sample and recording the resulting strain response as a function of time. The primary advantages of the considered material are (i) that the fracture network is well documented and (ii) that the homogeneous and non-porous glass matrix limits WIFF to the fracture network. Due to the high stress levels as well as other technical issues, creep tests are not commonly used for laboratory-based measurements of energy dissipation. Therefore, an objective of this study is to explore whether and to what extent such data can be interpreted in terms of the seismic attenuation characteristics of the probed samples, as this might open access to a vast reservoir of corresponding data, notably for cracked materials. Transforming the observed time-dependent stress-strain relation into the Fourier domain, allows us to infer the corresponding frequency-dependent attenuation characteristics, which we then seek to interpret through numerical simulations based on Biot's quasi-static poroelastic equations. The 2D geometry of the fracture network considered in these simulations is derived from a scanning electron

  7. A controlled source seismic attenuation study of the crust beneath Mount St. Helens with a dense array

    Science.gov (United States)

    Hupp, K.; Schmandt, B.; Kiser, E.; Hansen, S. M.; Levander, A.

    2016-12-01

    Crustal properties beneath Mount St. Helens are investigated using attenuation measurements from an array of 904 cable-free seismographs, referred to as nodes, located within 15 km of the summit crater. Measurements of P wave attenuation were made using 23 controlled explosion sources located 0 - 80 km outside the node array, which provides a well-balanced distribution of source-receiver azimuths and distances. The 500-1000 kg explosive sources were observed regionally, and all explosions produced P waves recorded with signal-to-noise power ratios of >3 dB for >90% of the node array. We estimate relative variations in the path-integrated attenuation parameter, t*, using 2 - 25 Hz spectral ratios of individual node spectra relative to the array median spectrum for each explosion source. For small source-receiver distances (>100). An exception to the previously mentioned trends is that for distances <30 km a ring of 150 nodes closest to the summit crater surrounding the base of the volcanic edifice yield low relative t* estimates ( -0.1s) and high mean envelope amplitudes at all frequencies from 2-25 Hz. The anomalous amplification of these "inner ring" recordings for small offsets could arise from very low impedance in the shallow crust beneath the edifice possibly enhanced by resonance within the edifice. Longer offset measurements will be used for 3D relative attenuation (dQ-1) tomography. We hypothesize that high attenuation (low Q) volumes may be observed at 5-15 km beneath Mount St. Helens where recent controlled source velocity tomography indicates high Vp/Vs. Adding attenuation constraints to recent seismic velocity results will aid estimating properties such as the melt fraction in the upper crustal magma reservoir.

  8. Accurate and efficient modeling of global seismic wave propagation for an attenuative Earth model including the center

    Science.gov (United States)

    Toyokuni, Genti; Takenaka, Hiroshi

    2012-06-01

    We propose a method for modeling global seismic wave propagation through an attenuative Earth model including the center. This method enables accurate and efficient computations since it is based on the 2.5-D approach, which solves wave equations only on a 2-D cross section of the whole Earth and can correctly model 3-D geometrical spreading. We extend a numerical scheme for the elastic waves in spherical coordinates using the finite-difference method (FDM), to solve the viscoelastodynamic equation. For computation of realistic seismic wave propagation, incorporation of anelastic attenuation is crucial. Since the nature of Earth material is both elastic solid and viscous fluid, we should solve stress-strain relations of viscoelastic material, including attenuative structures. These relations represent the stress as a convolution integral in time, which has had difficulty treating viscoelasticity in time-domain computation such as the FDM. However, we now have a method using so-called memory variables, invented in the 1980s, followed by improvements in Cartesian coordinates. Arbitrary values of the quality factor (Q) can be incorporated into the wave equation via an array of Zener bodies. We also introduce the multi-domain, an FD grid of several layers with different grid spacings, into our FDM scheme. This allows wider lateral grid spacings with depth, so as not to perturb the FD stability criterion around the Earth center. In addition, we propose a technique to avoid the singularity problem of the wave equation in spherical coordinates at the Earth center. We develop a scheme to calculate wavefield variables on this point, based on linear interpolation for the velocity-stress, staggered-grid FDM. This scheme is validated through a comparison of synthetic seismograms with those obtained by the Direct Solution Method for a spherically symmetric Earth model, showing excellent accuracy for our FDM scheme. As a numerical example, we apply the method to simulate seismic

  9. Structure-oriented singular value decomposition for random noise attenuation of seismic data

    Science.gov (United States)

    Gan, Shuwei; Chen, Yangkang; Zu, Shaohuan; Qu, Shan; Zhong, Wei

    2015-04-01

    Singular value decomposition (SVD) can be used both globally and locally to remove random noise in order to improve the signal-to-noise ratio (SNR) of seismic data. However, it can only be applied to seismic data with simple structure such that there is only one dip component in each processing window. We introduce a novel denoising approach that utilizes a structure-oriented SVD, and this approach can enhance seismic reflections with continuous slopes. We create a third dimension for a 2D seismic profile by using the plane-wave prediction operator to predict each trace from its neighbour traces and apply SVD along this dimension. The added dimension is equivalent to flattening the seismic reflections within a neighbouring window. The third dimension is then averaged to decrease the dimension. We use two synthetic examples with different complexities and one field data example to demonstrate the performance of the proposed structure-oriented SVD. Compared with global and local SVDs, and f-x deconvolution, the structure-oriented SVD can obtain much clearer reflections and preserve more useful energy.

  10. SASWeave: Literate Programming Using SAS

    Directory of Open Access Journals (Sweden)

    Russell V. Lenth

    2007-05-01

    Full Text Available SASweave is a collection of scripts that allow one to embed SAS code into a LATEX document, and automatically incorporate the results as well. SASweave is patterned after Sweave, which does the same thing for code written in R. In fact, a document may contain both SAS and R code. Besides the convenience of being able to easily incorporate SAS examples in a document, SASweave facilitates the concept of “literate programming”: having code, documentation, and results packaged together. Among other things, this helps to ensure that the SAS output in the document is in concordance with the code.

  11. Anisotropy of Earth's inner core intrinsic attenuation from seismic normal mode models

    NARCIS (Netherlands)

    Mäkinen, Anna M.; Deuss, Arwen; Redfern, Simon A T

    2014-01-01

    The Earth's inner core, the slowly growing sphere of solid iron alloy at the centre of our planet, is known to exhibit seismic anisotropy. Both normal mode and body wave studies have established that, when the global average is taken, compressional waves propagate faster in the North-South direction

  12. Anisotropy of Earth's inner core intrinsic attenuation from seismic normal mode models

    NARCIS (Netherlands)

    Mäkinen, Anna M.; Deuss, Arwen; Redfern, Simon A T

    2014-01-01

    The Earth's inner core, the slowly growing sphere of solid iron alloy at the centre of our planet, is known to exhibit seismic anisotropy. Both normal mode and body wave studies have established that, when the global average is taken, compressional waves propagate faster in the North-South direction

  13. SASWeave: Literate Programming Using SAS

    DEFF Research Database (Denmark)

    Lenth, Russell V; Højsgaard, Søren

    2007-01-01

    the convenience of being able to easily incorporate SAS examples in a document, SASweave facilitates the concept of "literate programming": having code, documentation, and results packaged together. Among other things, this helps to ensure that the SAS output in the document is in concordance with the code...

  14. SASWeave: Literate Programming Using SAS

    DEFF Research Database (Denmark)

    Lenth, Russell V; Højsgaard, Søren

    2007-01-01

    SASweave is a collection of scripts that allow one to embed SAS code into a LATEX document, and automatically incorporate the results as well. SASweave is patterned after Sweave, which does the same thing for code written in R. In fact, a document may contain both SAS and R code. Besides the conv...

  15. The influence of the Goos-Hänchen effect on seismic data processing and AVO in attenuating media

    Science.gov (United States)

    Wang, Zhiyong

    2015-11-01

    The Goos-Hänchen (GH) effect induced by the total reflection of an incident beam of P-wave from a low-impedance medium to a high-impedance medium at near- and post-critical angles was theoretically simulated and discussed. For both PP- and PSV-waves, there may be large GH shifts (GHS) and penetration depths (PD) for both lossless and attenuating media. As the Q-factor increases, or the frequency of the seismic wave decreases, the GH effect is increased. However, in attenuating media, there may be non-zero GHS and PD at all non-zero incident angles, not just post-critical angles. GHS may be either positive or negative, while PD is positive only. Compared to the Q-factor in the incident medium, the Q-factor in the transmission medium may play a more dominant role in the determination of reflection coefficients, GHS, and PD. The GH-induced normal moveout (NMO) discrepancy of the PSV-wave may be larger than that of the PP-wave. Due to the GH effect, there may be an angle discrepancy (at fixed offset) between the GH-modified incident angle and the traditional incident angle. In addition, the GH effect at a given offset may produce two or three reflected waves, from different incident angles. These results suggest that, within their assumptions, the GH effect may lead to errors in NMO estimates and the vertical location of the reflector. Furthermore, there may be errors in offsets, incident angles, and reflection amplitudes, in the analyses of the amplitude variation with offset (AVO). These GH effects might be more important for seismic data at fixed offsets and shallow layers, and for sonic log data, which might fall into the post-critical angle regime. Therefore, there may be a necessity to take into account the GH effect in the interpretation of wide-angle reflection data in NMO and AVO analyses.

  16. Analysis of dispersion and attenuation of surface waves in poroelastic media in the exploration-seismic frequency band

    Science.gov (United States)

    Zhang, Y.; Xu, Y.; Xia, J.

    2011-01-01

    We analyse dispersion and attenuation of surface waves at free surfaces of possible vacuum/poroelastic media: permeable-'open pore', impermeable-'closed pore' and partially permeable boundaries, which have not been previously reported in detail by researchers, under different surface-permeable, viscous-damping, elastic and fluid-flowing conditions. Our discussion is focused on their characteristics in the exploration-seismic frequency band (a few through 200 Hz) for near-surface applications. We find two surface-wave modes exist, R1 waves for all conditions, and R2 waves for closed-pore and partially permeable conditions. For R1 waves, velocities disperse most under partially permeable conditions and least under the open-pore condition. High-coupling damping coefficients move the main dispersion frequency range to high frequencies. There is an f1 frequency dependence as a constant-Q model for attenuation at high frequencies. R1 waves for the open pore are most sensitive to elastic modulus variation, but least sensitive to tortuosities variation. R1 waves for partially permeable surface radiate as non-physical waves (Im(k) Geophysical Journal International ?? 2011 RAS.

  17. Applied medical statistics using SAS

    CERN Document Server

    Der, Geoff

    2012-01-01

    ""Each chapter in the book is well laid out, contains examples with SAS code, and ends with a concise summary. The chapters in the book contain the right level of information to use SAS to apply different statistical methods. … a good overview of how to apply in SAS 9.3 the many possible statistical analysis methods.""-Caroline Kennedy, Takeda Development Centre Europe Ltd., Statistical Methods for Medical Research, 2015""… a well-organized and thorough exploration of broad coverage in medical statistics. The book is an excellent reference of statistical methods

  18. Frequency dependent attenuation of seismic waves for Delhi and surrounding area, India

    Directory of Open Access Journals (Sweden)

    Babita Sharma

    2015-06-01

    Full Text Available The attenuation properties of Delhi & surrounding region have been investigated using 62 local earthquakes recorded at nine stations. The frequency dependent quality factors Qa (using P-waves and Qb (using S-waves have been determined using the coda normalization method. Quality factor of coda-waves (Qc has been estimated using the single backscattering model in the frequency range from 1.5 Hz to 9 Hz. Wennerberg formulation has been used to estimate Qi (intrinsic attenuation parameter and Qs (scattering attenuation parameter for the region. The values Qa, Qb, Qc, Qi and Qs estimated are frequency dependent in the range of 1.5Hz-9Hz. Frequency dependent relations are estimated as Qa=52f1.03, Qb=98f1.07 and Qc=158f0.97. Qc estimates lie in between the values of Qi and Qs but closer to Qi at all central frequencies. Comparison between Qi and Qs shows that intrinsic absorption is predominant over scattering for Delhi and surrounding region. 

  19. Nye grafiske muligheder i SAS

    DEFF Research Database (Denmark)

    Milhøj, Anders

    2009-01-01

    Den vigtigste i SAS version 9.2 indenfor grafik er mulighederne for at producere dokumentationsgrafik i mange statistiske procedurer. Det drejer sig især om grafikker til modelkontrol, fx. residualdiagrammer, influensplot, normalfraktildiagrammer for residualerne etc.......Den vigtigste i SAS version 9.2 indenfor grafik er mulighederne for at producere dokumentationsgrafik i mange statistiske procedurer. Det drejer sig især om grafikker til modelkontrol, fx. residualdiagrammer, influensplot, normalfraktildiagrammer for residualerne etc....

  20. New data on seismic wave attenuation in the lithosphere and upper mantle of the northeastern flank of the Baikal rift system

    Science.gov (United States)

    Dobrynina, A. A.; Sankov, V. A.; Chechelnitsky, V. V.

    2016-05-01

    The investigation data on seismic wave attenuation in the lithosphere and upper mantle of the northeastern flank of the Baikal rift system obtained with a seismic coda envelope and sliding window are considered. Eleven local districts were described by one-dimensional attenuation models characterized by alternation of high and low attenuation layers, which are consistent with the results obtained previously by Yu.F. Kopnichev for the southwestern flank of the Baikal rift system [9]. The subcrust of the lithosphere contains a thin layer with high attenuation of seismic waves likely related to higher heterogeneity (fragmentation) and occurrence of fluids. The lithosphere basement depth varies from 100-120 km in the west within the Baikal folded area to 120-140 km in the east within the Siberian Platform. It is concluded that there are two asthenosphere layers. Based on specific features of the lithosphere and upper mantle structure, it can be assumed that they were subject to gradual modification involving fluidization processes and partial melting in the Late Cenozoic extension under the influence of distant tectogenesis sources.

  1. Attenuation of short period seismic waves at Etna as compared to other volcanic areas

    Science.gov (United States)

    Del Pezzo, E.; Gresta, S.; Patané, G.; Patané, D.; Scarcella, G.

    1987-11-01

    Coda Q for Etna volcano is frequency dependent and the Q frequency pattern and the numerical values ranging from about 100 at 1 Hz to about 300 at 18 Hz are similar to the values obtained for other volcanoes: Campi Flegrei, Aeolian Islands and Hawaii. Moreover the frequency pattern and the numerical values of coda quality factor, for most of the seismically active zones of Italy are very different from those of the volcanic zones. Several studies of the location of magma chambers show the presence of magma pockets beneath Lipari and Vulcano Islands of the Aeolian archipelago and an anomalous low velocity body beneath Etna. These evidences suggest that a possible interpretation of the characteristic frequency pattern of Q on volcanic areas is that the presence of magma can modify the scattering environment and consequently the coda Q estimates.

  2. Determination of combined effect of amplification and attenuation of soft rock site using digital seismic data

    Institute of Scientific and Technical Information of China (English)

    姜慧; 高孟潭; 俞言祥; 赵翠萍

    2004-01-01

    In the paper, for thc application of stochastic simulation of ground motion, we put forward a method to determine"the combined effect of amplification and attenuation" (combined effect for short) of soft rock site by using digitalseismic data of moderate and small earthquakes. Our approach aims at solving the problem of the combined effectof soft rock site, which is difficult to determine in most regions of China because fewer measures were done forS-wave velocity structure. Thc combined effect of soft rock site can be determined by using the approach recommended by us. An example is given to discuss the practical application of the method.

  3. The Influence of Water on Seismic Wave Speeds and Attenuation in the Upper Mantle: an update from the Laboratory

    Science.gov (United States)

    Cline, C. J., II; David, E. C.; Jackson, I.; Faul, U.; Berry, A.

    2015-12-01

    A fine-grained synthetic olivine (Fo90) polycrystal, doped with ~0.04 wt. % TiO2, has been prepared with ~70 wt. ppm H2O accommodated in the remarkably stable Ti-clinohumite defect typical of natural olivines from the Earth's generally water-undersaturated upper mantle (Berry et al., 2005). A precision-ground specimen of this material, sleeved in Pt tubing within a mild-steel jacket, was tested in torsional forced oscillation at seismic frequencies (mHz-Hz) and temperatures to 1200 °C, under 200 MPa confining pressure. The shear modulus was observed to decrease systematically with increasing oscillation period and temperature, accompanied by monotonically increasing dissipation, which are characteristic of absorption band or high-temperature-background behaviour. In a previous preliminary report, the new data were compared with the model of Jackson and Faul (Phys. Earth Planet. Interiors, 2010) for a suite of essentially anhydrous Ti-free olivine polycrystals, evaluated at the 25 μm grain size of the hydrous titaniferous olivine specimen, showing that the latter is vastly more dissipative than its anhydrous equivalent (by an order of magnitude at 1200 °C) and correspondingly lower in shear modulus. The results of additional experiments now better constrain the mechanical behaviour of the enclosing Pt sleeve and allow direct comparison with data for an anhydrous titaniferous olivine of comparable grain size. The latest results confirm a very strong influence of water on seismic wave attenuation, even under the water-undersaturated conditions expected to prevail in the Earth's upper mantle.

  4. SAS FORMATS: USES AND ABUSES

    Science.gov (United States)

    SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying it. Formats can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As ...

  5. Seismic attenuation structure associated with episodic tremor and slip zone beneath Shikoku and the Kii peninsula, southwestern Japan, in the Nankai subduction zone

    Science.gov (United States)

    Kita, Saeko; Matsubara, Makoto

    2016-03-01

    The three-dimensional seismic attenuation structure (frequency-independent Q) beneath southwestern Japan was analyzed using t* estimated by applying the S coda wave spectral ratio method to the waveform data from a dense permanent seismic network. The seismic attenuation (Qp-1) structure is clearly imaged for the region beneath Shikoku, the Kii peninsula, and eastern Kyushu at depths down to approximately 50 km. At depths of 5 to 35 km, the seismic attenuation structure changes at the Median tectonic line and other geological boundaries beneath Shikoku and the southwestern Kii peninsula. High-Qp zones within the lower crust of the overlying plate are found just above the slip regions at the centers of the long-term slow-slip events (SSEs) beneath the Bungo and Kii channels and central Shikoku. Beneath central Shikoku, within the overlying plate, a high-Qp zone bounded by low-Qp zones is located from the land surface to the plate interface of the subducting plate. The high-Qp zone and low-Qp zones correspond to high-Vp and low-Vp zones of previous study, respectively. The boundaries of the high- and low-Qp zones are consistent with the segment boundaries of tremors (segment boundaries of short-term SSEs). These results indicated that the locations of the long- and short-term SSEs could be limited by the inhomogeneous distribution of the materials and/or condition of the overlying plate, which is formed due to geological and geographical process. The heterogeneity of materials and/or condition within the fore-arc crust possibly makes an effect on inhomogeneous rheological strength distribution on the interface.

  6. Strong S-wave attenuation and actively degassing magma beneath Taal volcano, Philippines, inferred from source location analysis using high-frequency seismic amplitudes

    Science.gov (United States)

    Kumagai, H.; Lacson, R. _Jr., Jr.; Maeda, Y.; Figueroa, M. S., II; Yamashina, T.

    2014-12-01

    Taal volcano, Philippines, is one of the world's most dangerous volcanoes given its history of explosive eruptions and its close proximity to populated areas. A key feature of these eruptions is that the eruption vents were not limited to Main Crater but occurred on the flanks of Volcano Island. This complex eruption history and the fact that thousands of people inhabit the island, which has been declared a permanent danger zone, together imply an enormous potential for disasters. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) constantly monitors Taal, and international collaborations have conducted seismic, geodetic, electromagnetic, and geochemical studies to investigate the volcano's magma system. Realtime broadband seismic, GPS, and magnetic networks were deployed in 2010 to improve monitoring capabilities and to better understand the volcano. The seismic network has recorded volcano-tectonic (VT) events beneath Volcano Island. We located these VT events based on high-frequency seismic amplitudes, and found that some events showed considerable discrepancies between the amplitude source locations and hypocenters determined by using onset arrival times. Our analysis of the source location discrepancies points to the existence of a region of strong S-wave attenuation near the ground surface beneath the east flank of Volcano Island. This region is beneath the active fumarolic area and above sources of pressure contributing inflation and deflation, and it coincides with a region of high electrical conductivity. The high-attenuation region matches that inferred from an active-seismic survey conducted at Taal in 1993. Our results, synthesized with previous results, suggest that this region represents actively degassing magma near the surface, and imply a high risk of future eruptions on the east flank of Volcano Island.

  7. Improved Lg attenuations maps in the central U.S.-Rocky Mountain transition zone: New insight from induced seismicity in Oklahoma, Kansas, and the Raton Basin

    Science.gov (United States)

    AbdelHameid, D.; Levandowski, W. B.; Boyd, O. S.; McNamara, D. E.

    2016-12-01

    Regional-scale differences in seismic attenuation exist across the continental United States, and it is well established that attenuation of Lg-phase waves is greater west of the Rocky Mountains than east of the Rocky Mountains. Yet there is less clarity in defining the transition in attenuation, as few near-field strong motion observations have been available in the central United States. A recent abundance of induced earthquakes in Oklahoma, southern Kansas, and the Raton Basin have provided unprecedented coverage. Utilizing Lg-phase waves recorded at regional distances (200-1500 km) at 300 seismic stations from Oklahoma to central Nevada, we compute the path-averaged apparent Q, source terms, and local amplification factors at one-octave frequency bands centered at 0.75, 1.0, 3.0, 6.0, and 12.0 Hz. Amplification correlates better with km-scale topographic relief than local slope on the Great Plains and Gulf Coast, and is generally greater east of the Rocky Mountain Front than west. We do not observe any difference between magnitude-source term scaling for induced events and for natural seismicity, suggesting that either source term is not a proxy for stress drop or that the stress drops of induced events are not lower than for natural events. Subsequently subdividing the study area into distinct physiographic regions, we quantify the average path-averaged Q in the Basin and Range, Colorado Plateau, Rocky Mountains, Gulf Coast, and Great Plains. As in previous work, we find roughly 50-100% greater Q in the Plains and Plateau than in the Rockies and Basin and Range. Preliminary 2-D tomography delineates a sharp (100-200 km-wide) boundary between adjacent Q-provinces. Our refined Q(f) model supplements the attenuation component of the USGS National Crustal Model and provides improved ground motion characterization in the USGS National Seismic Hazard map, particularly in the central United States in which shaking from induced seismicity is of increasing concern.

  8. The 2001 Mw7.7 Bhuj, India Earthquake and Eastern North American Ground-Motion Attenuation Relations: Seismic Hazard Implications

    Science.gov (United States)

    Cramer, C. H.; Bhattacharya, S. N.; Kumar, A.

    2002-12-01

    It has been suggested that the Mw7.7 2001 Bhuj, India earthquake occurred in a stable continental region with ground-motion attenuation properties similar to eastern North America (ENA). No strong motion recordings for M7 or greater earthquakes have been recorded in ENA, so, if the two regions share similar properties, then observations from the Bhuj earthquake provide important information for hazard assessments in ENA as well as India. This thesis can be tested using seismic data for the Bhuj mainshock. The Indian Meteorological Department recorded accelerograph and broadband seismograph data at distances of 500 to 1800 km. Accelerograph and engineering seismoscope data were recorded at distances of 40 to 1100 km by the Department of Earthquake Engineering at the Indian Institute of Technology, Roorkee. We have processed the accelerograph and broadband data for response spectral accelerations and corrected them to a common NEHRP site class using Joyner and Boore (2000) site factors. The geologic conditions at each recording site were determined using the geologic map of India and categorized as Quaternary sediments, Tertiary sediments, or hard rock. Comparisons were then made to available ENA ground-motion attenuation relations. For peak ground acceleration (PGA) and 1.0 s spectral acceleration (Sa), the geologically-corrected Bhuj data generally fall among the ENA ground-motion attenuation relations. The Bhuj mainshock ground-motion data agree with the collective predictions of the ENA relations given the random uncertainty in ground-motion measurements of a factor of two or more plus the ground-motion attenuation relation modeling uncertainty. From an engineering perspective, this comparison supports the thesis that seismic-wave attenuation in stable continental India is similar to eastern North America.

  9. SAS4 and SAS5 are locus-specific regulators of silencing in Saccharomyces cerevisiae.

    OpenAIRE

    Xu, E. Y; S. Kim; Rivier, D H

    1999-01-01

    Sir2p, Sir3p, Sir4p, and the core histones form a repressive chromatin structure that silences transcription in the regions near telomeres and at the HML and HMR cryptic mating-type loci in Saccharomyces cerevisiae. Null alleles of SAS4 and SAS5 suppress silencing defects at HMR; therefore, SAS4 and SAS5 are negative regulators of silencing at HMR. This study revealed that SAS4 and SAS5 contribute to silencing at HML and the telomeres, indicating that SAS4 and SAS5 are positive regulators of ...

  10. Frequency-dependent seismic coda-attenuation imaging of volcanic geomorphology: from debris flows at Mount St. Helens volcano to cross-faulting at Campi Flegrei caldera.

    Science.gov (United States)

    De Siena, Luca; Gabrielli, Simona; Spagnolo, Matteo

    2017-04-01

    The stochastic loss of energy measured using the later portion of seismic recordings (coda) can be used to image and monitor geomorphology in volcanoes, once appropriate sensitivity kernels for the application of attenuation tomography have been developed. The use of this advanced seismic method with GIS/InSAR techniques is an unexplored field, which is receiving increasing attention in volcano-seismology. By using this integrated approach we can image structure and monitor dynamics of the debris flow that followed the 1980 explosive eruption of Mount St. Helens (US) volcano at resolution similar to that of remote sensing data, and depths of Italy, the results provide a novel perspective on the links between deep fluid migration and surface structures. The implications of the proposed approach on volcano monitoring are evident.

  11. Constraints on grain size and stable iron phases in the uppermost Inner Core from multiple scattering modeling of seismic velocity and attenuation

    CERN Document Server

    Calvet, Marie

    2008-01-01

    We propose to model the uppermost inner core as an aggregate of randomly oriented anisotropic ``patches''. A patch is defined as an assemblage of a possibly large number of crystals with identically oriented crystallographic axes. This simple model accounts for the observed velocity isotropy of short period body waves, and offers a reasonable physical interpretation for the scatterers detected at the top of the inner core. From rigorous multiple scattering modeling of seismic wave propagation through the aggregate, we obtain strong constraints on both the size and the elastic constants of iron patches. We perform a systematic search for iron models compatible with measured seismic velocities and attenuations. An iron model is characterized by its symmetry (cubic or hexagonal), elastic constants, and patch size. Independent of the crystal symmetry, we infer a most likely size of patch of the order of 400 m. Recent {\\it bcc} iron models from the literature are in very good agreement with the most probable elast...

  12. Joint Interpretation of Multi-parameter Tomographic Models (e.g., Seismic P and S Velocity, Anisotropy, Attenuation): A Neural Network Approach

    Science.gov (United States)

    Bauer, K.

    2008-12-01

    Seismic tomography can provide a set of models which represent different properties of the same target region. A typical example is the development of coincident P and S velocity cross sections from travel time tomography. Other applications may include additional determination of attenuation and anisotropy. Self-organizing maps (SOM) are powerful neural network techniques to classify and interpret multi-attribute data sets. The coincident tomographic images are translated to a set of data vectors in order to train a Kohonen layer. The total gradient of the model vectors is determined for the trained SOM and a watershed segmentation algorithm is used to visualize and map the lithological clusters with well-defined seismic signatures. The principal working flow is demonstrated for a synthetic data set. Further examples include P and S velocity tomography across a sub-volcanic ring complex in Namibia, and combination of velocity, anisotropy, and attenuation tomography to characterize gas hydrate bearing sediments in the Mackenzie Delta, NW Canada.

  13. What's new in SAS 9.3

    DEFF Research Database (Denmark)

    Milhøj, Anders

    2012-01-01

    I foråret 2010 blev den ny SAS version SAS 9.22 lanceret som en opdatering af SAS 9.2, med væsentlige nye muligheder for netop statistik. Her i sommeren 2011 blev version 9.3 så lanceret med endnu flere nyskabelser i både generel performance og specielt indenfor statistik, økonometri og...

  14. Conducting Meta-Analysis Using SAS

    CERN Document Server

    Arthur, Winfried; Huffcutt, Allen I; Arthur, Winfred

    2001-01-01

    Conducting Meta-Analysis Using SAS reviews the meta-analysis statistical procedure and shows the reader how to conduct one using SAS. It presents and illustrates the use of the PROC MEANS procedure in SAS to perform the data computations called for by the two most commonly used meta-analytic procedures, the Hunter & Schmidt and Glassian approaches. This book serves as both an operational guide and user's manual by describing and explaining the meta-analysis procedures and then presenting the appropriate SAS program code for computing the pertinent statistics. The practical, step-by-step instru

  15. A model for strong attenuation and dispersion of seismic P-waves in a partially saturated fractured reservoir

    Institute of Scientific and Technical Information of China (English)

    BRAJANOVSKI; Miroslav; MüLLER; Tobias; M; PARRA; Jorge; O

    2010-01-01

    In this work we interpret the data showing unusually strong velocity dispersion of P-waves (up to 30%) and attenuation in a relatively narrow frequency range. The cross-hole and VSP data were measured in a reservoir, which is in the porous zone of the Silurian Kankakee Limestone Formation formed by vertical fractures within a porous matrix saturated by oil, and gas patches. Such a medium exhibits significant attenuation due to wave-induced fluid flow across the interfaces between different types of inclusions (fractures, fluid patches) and background. Other models of intrinsic attenuation (in particular squirt flow models) cannot explain the amount of observed dispersion when using realistic rock properties. In order to interpret data in a satisfactory way we develop a superposition model for fractured porous rocks accounting also for the patchy saturation effect.

  16. SAS : kosheljok ili proshtshai, Estonian Air!

    Index Scriptorium Estoniae

    2008-01-01

    Lennukompanii SAS saatis Eesti valitsusele kirja, milles teatab, et on nõus raskustesse sattunud Estonian Airile lisainvesteeringuid tegema ainult siis, kui valitsus müüb SAS-ile oma osaluse. Ettevõtjate, parlamendiliige Marko Mihkelsoni ja ministrite arvamusi

  17. A SAS IML Macro for Loglinear Smoothing

    Science.gov (United States)

    Moses, Tim; von Davier, Alina

    2011-01-01

    Polynomial loglinear models for one-, two-, and higher-way contingency tables have important applications to measurement and assessment. They are essentially regarded as a smoothing technique, which is commonly referred to as loglinear smoothing. A SAS IML (SAS Institute, 2002a) macro was created to implement loglinear smoothing according to…

  18. An attenuation study in Southern Italy using local and regional earthquakes recorded by seismic network of Basilicata

    Directory of Open Access Journals (Sweden)

    M. Mucciarelli

    2004-06-01

    Full Text Available We determined a set of empirical functions that describe the spectral amplitude decay of S-waves with distance in Southern Italy. We analyzed 32 earthquakes with magnitudes ML 2.0-5.4 and hypocentral distances ranging between 12 and 216 km. We obtained attenuation functions for 14 frequencies(1.0< f<20.0 Hz. We compared these functions with average non-parametric attenuation functions reported by Castro et al. (1999 for different regions of Italy, and we observe that at low frequencies (f<5.0 Hz the spectral amplitudes from earthquakes in Southern Italy decay faster than the average. However, at high frequencies ( f > 5.0 Hz, the spectral amplitudes are above the average. At higher frequencies ( f > 10 Hz, the attenuation functions obtained for Southern Italy are slightly above the standard deviation of the average attenuation functions. It is possible that in this frequency range (10-20 Hz site effects may influence the amplitude decay. In order to quantify the attenuation of the S-waves, we estimated the quality factor Q modeling the empirical attenuation functions using the following parametric form: A( f , r=10/r b·e- pfR/Q ß; where 1.6 = f = 10.0 Hz is the frequency band with minimum effect of instrument and site response, r = 120 km is the distance range where the rate of decay of the spectral amplitudes is approximately constant, R=(r-10 and ß=3.2 km/s. We found that the exponent b=1.0±0.2 in the frequency band analyzed and Q shows a frequency dependence that can be approximated by the function Q=32.1 f 1.7.

  19. The SAS-3 delayed command system

    Science.gov (United States)

    Hoffman, E. J.

    1975-01-01

    To meet the requirements arising from the increased complexity of the power, attitude control and telemetry systems, a full redundant high-performance control section with delayed command capability was designed for the Small Astronomy Satellite-3 (SAS-3). The relay command system of SAS-3 is characterized by 56 bystate relay commands, with capability for handling up to 64 commands in future versions. The 'short' data command service of SAS-1 and SAS-2 consisting of shifting 24-bit words to two users was expanded to five users and augmented with a 'long load' data command service (up to 4080 bits) used to program the telemetry system and the delayed command subsystem. The inclusion of a delayed command service ensures a program of up to 30 relay or short data commands to be loaded for execution at designated times. The design and system operation of the SAS-3 command section are analyzed, with special attention given to the delayed command subsystem.

  20. The SAS-3 programmable telemetry system

    Science.gov (United States)

    Peterson, M. R.

    1975-01-01

    Basic concept, system design and operation principles of the telemetry system developed for the Small Astronomy Satellite-3 (SAS-3) are analyzed. The concept of programmable format selected for the SAS-3 represents an optical combination of the fixed format system of SAS-1 and SAS-2, and the adaptive format concept. The programmable telemetry system permits a very wide range of changes in the data sampling order by a ground control station, depending on the experimental requirements, so that the maximal amount of useful data can be returned from orbit. The programmable system also allows the data format to differ from one spacecraft to another without changing hardware. Attention is given to the command requirements and redundancy of the SAS-3 telemetry system.

  1. L'atténuation intrinsèque des ondes sismiques. Troisième partie : Mécanismes régissant l'atténuation. Intrinsic Attenuation of Seismic Waves. Part Three: Mechanisms Governing Attenuation

    Directory of Open Access Journals (Sweden)

    Bourbie T.

    2006-11-01

    Full Text Available Les mécanismes qui régissent l'atténuation sont très complexes et encore mal compris actuellement. Certains mécanismes ont pu être éliminés comme le phénomène de frottement grain à grain du fait des amplitudes de déformation usuelles en sismique. Il. semble que les mécanismes responsables soient différents dans le cas de roches sèches (aux conditions de laboratoire et dans le cas de roches plus ou moins saturées. Dans le cas de roches sèchesl'atténuation semble provenir à la fois d'un hystérésis microcapillaire et d'une rupture des liaisons hydrogènes entre les hydroxyles de la surface et les molécules d'eau. Dans le cas de roches saturées, les candidats les plus probables au phénomène d'atténuation sont les mécanismes de Biot et de squirt flow . Le mécanisme de Biot est la possibilité d'avoir des mouvements différentiels globaux (ou plutôt moyennés à l'échelle de l'échantillon entre la matière solide et le fluide. Le squirt flowconsiste en un phénomène de relaxation visqueuse dont l'excitateur est extérieur : le liquide à l'intérieur de la cavité poreuse jaillit sous l'effet d'une pression de pore locale. The mechanisms governing attenuation are highly complex and still poorly understood at present. Some mechanisms have been eliminated, such as the grain-to-grain friction, due to the usual deformation amplitudes in seismic exploration. The mechanisms responsible for attenuation seem to be different for dry rocks (under laboratory conditions and more or less saturated rocks. For dryrocks, attenuation seems to come from both a microcapillary hysteresis and a break of the hydrogen bonds between the surface hydroxyls and water molecules. For saturated rocks, the most probable causes of attenuation are Biot mechanisms and squirt flow. The Biot mechanism Is the possibility of having overall differential movements (or rather averaged ones on the scale of the sample between the solid matrix and the fluid

  2. Extending and Enhancing SAS (Static Analysis Suite)

    CERN Document Server

    Ho, David

    2016-01-01

    The Static Analysis Suite (SAS) is an open-source software package used to perform static analysis on C and C++ code, helping to ensure safety, readability and maintainability. In this Summer Student project, SAS was enhanced to improve ease of use and user customisation. A straightforward method of integrating static analysis into a project at compilation time was provided using the automated build tool CMake. The process of adding checkers to the suite was streamlined and simplied by developing an automatic code generator. To make SAS more suitable for continuous integration, a reporting mechanism summarising results was added. This suitability has been demonstrated by inclusion of SAS in the Future Circular Collider Software nightly build system. Scalability of the improved package was demonstrated by using the tool to analyse the ROOT code base.

  3. Key Performance Indicators for SAS Flights

    OpenAIRE

    Arhall, Johanna; Cox, Emmie

    2013-01-01

    Revenue management is a thoroughly researched field of study and it is widely used in several different industries. The Revenue Management Department at the airline SAS (Scandinavian Airline System) serves to maximise the profit of the company’s flights. At their disposal they have a number of tools, which use KPIs (Key Performance Indicators) as a measurement. The KPIs are used in prognosis to determine future initiatives, and to analyse and verify results. SAS does not know if the KPIs they...

  4. SAS doctors career progression survey 2013.

    Science.gov (United States)

    Oroz, Carlos; Sands, Lorna R; Lee, John

    2016-03-01

    We conducted a national survey of Staff, Associate Specialists and Specialty (SAS) doctors working in sexual health clinics in the UK in 2013 in order to explore their career progression. The aim of the survey was to assess SAS doctors' experience in passing through the thresholds and to gather information about the adherence by SAS doctors and employers to the terms and conditions of service laid out by the new 2008 contract. Out of 185 responders, whom the authors estimate comprise 34% of the total workforce, 159 were on the new contract. Of those, most SAS doctors were women (84%), the majority (67%) worked less than nine programmed activities per week; only a few had intentions to join the consultant grade (15%), and a considerable minority (26%) were older than 54 years of age and likely to retire in the next ten years. The survey showed that most participating SAS doctors had undergone appraisal in the previous 15 months (90%), most had a job planning discussion (83%) with their employer and most had some allocated time for supporting professional activities (86%). However, a significant minority had no appraisal (10%), no job planning discussion (17%) and had no allocated supporting professional activities (14%), which allows time for career development in the specialty. Most SAS doctors, who had the opportunity, had progressed through the thresholds automatically (88%); some experienced difficulties in passing (8%) and only a few did not pass (4%). SAS doctors must ensure that they work together with their employer in order to improve adherence to the terms and conditions of service of the contract, which allow for career progression and benefit both the individual doctors and ultimately service provision.

  5. The SAS-3 X-ray observatory

    Science.gov (United States)

    Mayer, W. F.

    1975-01-01

    The experiment section of the Small Astronomy Satellite-3 (SAS-3) launched in May 1975 is an X-ray observatory intended to determine the location of bright X-ray sources to an accuracy of 15 arc-seconds; to study a selected set of sources over a wide energy range, from 0.1 to 55 keV, while performing very specific measurements of the spectra and time variability of known X-ray sources; and to monitor the sky continuously for X-ray novae, flares, and unexpected phenomena. The improvements in SAS-3 spacecraft include a clock accurate to 1 part in 10 billion, rotatable solar panels, a programmable data format, and improved nutation damper, a delayed command system, improved magnetic trim and azimuth control systems. These improvements enable SAS-3 to perform three-axis stabilized observations of any point on the celestial sphere at any time of the year. The description of the experiment section and the SAS-3 operation is followed by a synopsis of scientific results obtained from the observations of X-ray sources, such as Vela X-1 (supposed to be an accreting neutron star), a transient source of hard X-ray (less than 36 min in duration) detected by SAS-3, the Crab Nebula pulsar, the Perseus cluster of galaxies, and the Vela supernova remnant.

  6. Attenuation of Lg waves in the New Madrid seismic zone of the central United States using the coda normalization method

    Science.gov (United States)

    Nazemi, Nima; Pezeshk, Shahram; Sedaghati, Farhad

    2017-08-01

    Unique properties of coda waves are employed to evaluate the frequency dependent quality factor of Lg waves using the coda normalization method in the New Madrid seismic zone of the central United States. Instrument and site responses are eliminated and source functions are isolated to construct the inversion problem. For this purpose, we used 121 seismograms from 37 events with moment magnitudes, M, ranging from 2.5 to 5.2 and hypocentral distances from 120 to 440 km recorded by 11 broadband stations. A singular value decomposition (SVD) algorithm is used to extract Q values from the data, while the geometric spreading exponent is assumed to be a constant. Inversion results are then fitted with a power law equation from 3 to 12 Hz to derive the frequency dependent quality factor function. The final results of the analysis are QVLg (f) = (410 ± 38) f0.49 ± 0.05 for the vertical component and QHLg (f) = (390 ± 26) f0.56 ± 0.04 for the horizontal component, where the term after ± sign represents one standard error. For stations within the Mississippi embayment with an average sediment depth of 1 km around the Memphis metropolitan area, estimation of quality factor using the coda normalization method is not well-constrained at low frequencies (f < 3 Hz). There may be several reasons contributing to this issue, such as low frequency surface wave contamination, site effects, or even a change in coda wave scattering regime which can exacerbate the scatter of the data.

  7. 岩石中波传播速度频散与衰减%Velocity dispersion and attenuation of seismic wave propagation in rocks

    Institute of Scientific and Technical Information of China (English)

    王海洋; 孙赞东; Mark CHAPMAN

    2012-01-01

    速度频散与衰减是地震岩石物理领域一个前沿性问题,它不仅是开展频率域储层及流体预测的关键理论基础,同时也是解决不同地球物理测量方法(地面地震、VSP、测井、超声波岩心观测等)之间数据匹配困难的重要手段.笔者在阐述速度频散和衰减现象基本特征的基础上,详细回顾了Biot模型、喷射流模型、BISQ模型、双孔模型、裂缝-孔隙微结构模型和斑块饱和模型等6种主要速度频散与衰减理论模型的研究进程、原理和限制性,利用示意图直观地描述了这些模型的机制,并给出了它们各自的高低频极限、特征频率和适用条件.同时系统回顾并分析了国内外半个多世纪来速度频散与衰减实验测量技术的发展进程和应用现状,并在实验测量数据的基础上给出了自己对地球物理测量手段、岩石物理模型与频率相关性方面的思考和认识,即有必要将单频带的岩石物理模型拓展到全频带,并基于此将不同频带地球物理手段的测量数据联系起来,实现在同一尺度下的综合应用.%A velocity dispersion and attenuation phenomenon is a frontier subject in seismic rock physics. It is not only a key theoretical fundament for reservoir and fluid prediction in the frequency domain but also a crucial technique to solve the data-matching problem of different geophysical measurements, such as surface seismic method, vertical seismic profiling (VSP), well logging, laboratory ultrasonic core observation etc. Based on elaborating characteristics of this phenomenon, we reviewed in detail the progress in development, principles and limitations of six typical velocity dispersion and attenuation models including Biot, Squirt-flow, Biot-Squirt (BISQ), double-porosity, crack-pore microstructure and patchy saturation models, visually depicted mechanisms of these models u-sing schematic diagrams, and at the same time deduced their respective high- and

  8. SAS-2 galactic gamma ray results, 1

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Lamb, R. C.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1976-01-01

    Continuing analysis of the data from the SAS-2 high energy gamma-ray experiment has produced an improved picture of the sky at photon energies above 35 MeV. On a large scale, the diffuse emission from the galactic plane is the dominant feature observed by SAS-2. This galactic plane emission is most intense between galactic longitude 310 and 45 deg, corresponding to a region within 7kpc of the galactic center. Within the high-intensity region, SAS-2 observes peaks around galactic longitudes 315 deg, 330 deg, 345 deg, 0 deg, and 35 deg. These peaks appear to be correlated with such galactic features and components as molecular hydrogen, atomic hydrogen, magnetic fields, cosmic ray concentrations, and photon fields.

  9. Statistical hypothesis testing with SAS and R

    CERN Document Server

    Taeger, Dirk

    2014-01-01

    A comprehensive guide to statistical hypothesis testing with examples in SAS and R When analyzing datasets the following questions often arise:Is there a short hand procedure for a statistical test available in SAS or R?If so, how do I use it?If not, how do I program the test myself? This book answers these questions and provides an overview of the most commonstatistical test problems in a comprehensive way, making it easy to find and performan appropriate statistical test. A general summary of statistical test theory is presented, along with a basicdescription for each test, including the

  10. SAS 3 survey of the soft X-ray background

    Science.gov (United States)

    Marshall, F. J.; Clark, G. W.

    1984-01-01

    The results of a survey of the soft X-ray sky in the C band (0.10-0.28keV) are reported. The observations were carried out using two independent flow proportional counters on board the SAS 3 X-ray satellite which had a total angular resolution of 2.9 deg FWHM, and a total exposure of 2.2 x 10 to the 4th per sq cm s sr. It is found that C band counting rates were generally inversely correlated with the column density of the neutral hydrogen on all angular scales down to the lowest angular resolution of the detectors. In the region 90-180 deg l and 0-10 deg b, the relation between C-band rates and the column densities of neutral hydrogen was fitted with a residual rms deviation of less than 13 percent by a two-component numerical model of the X-ray background. For the apparent attenuation column density a value of 2.7 x 10 to the 20th per sq cm was obtained. On the basis of a computer simulation of the SAS 3 data, it is shown that the observed clumping of interstellar matter was consistent with the magnitude of spatial fluctuations in the C-band map. When the background rates were subtracted from the survey map, the subsequent map showed foreground emission and absorption features with improved sensitivity and clarity. A series of computer-generated maps incorporating the SAS 3 data is given in an appendix.

  11. SAS wave experiment on board Magion 4

    Directory of Open Access Journals (Sweden)

    J. Błęcki

    Full Text Available A short description of the SAS (subsatellite analyser of spectra wave experiment on board the Magion-4 subsatellite is given. We present first measurements of the magnetic-field fluctuations in the frequency range 32–2000 Hz obtained in the magnetotail during the disturbed period at the magnetopause and in the polar cusp.

  12. Beijing, the SAS Gateway to China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Scandinavian Airlines has launched the direct route from Stockholm to Beijing.China's Foreign Trade had an interview with Mr. Lars Lindgren,CEO of Scandinavian Airlines International (SAS).He pointed out that they expect to see that all across Scandinavia will be opened to China,and before long Beijing will become Scandinavian Airlines' gateway to China. The follows are the interview.

  13. Hydro-seismic-acoustical monitoring of submarine earthquakes preparation: observations and analysis

    Directory of Open Access Journals (Sweden)

    E. V. Sasorova

    2008-01-01

    Full Text Available The results of laboratory experiments on rock sample destruction and the observation data obtained from several series of the hydro-acoustic observations in which the researchers succeeded to register the signals in the critical stage of the earthquake (EQ preparation were compared. According to theoretical research (Alekseev et al., 2001 two distinct dilatant zones occur in the EQ preparation stage. The first one is located around the source and the second one represents the near-surface dilatant zone. Only high-frequency seismic-acoustic signals (SAS radiated from the near-surface dilatant zone do not attenuate completely on the passage through a solid medium. Parameters of the SAS such as the source depth under the ocean floor, frequency maximum and the signal power level were estimated. It was shown that the critical stage of the EQ preparation continues several tens hours and this process has a hierarchical nature. At first the micro-ruptures are formed over a large area. Then the high frequency radiation begins to decrease, the SAS emission area begins to shrink and the micro-earthquakes occur in the area surrounding the epicenter. The obtained results are in close agreement with the theoretical conception about the evolution of the SAS in the surface dilatant zone and with the results of laboratory experiments.

  14. The SAS-3 power and thermal systems

    Science.gov (United States)

    Sullivan, R. M.; Hogrefe, A. F.; Brenza, P. T.

    1975-01-01

    Solar array configurations of the SAS-3 are described: a configuration with two sets of coplanar panels in the horizontal and two others in the vertical position, and two other configurations with either four horizontal or four vertical sets of panels. The nickel-cadmium battery of the power subsystem is described in detail, with emphasis on voltage limits and charge-discharge characteristics. The characteristic of 'solar-only' operation in the case of damage to the battery is discussed. The thermal subsystem of SAS-3 is considered, with discussions of thermal design criteria and the thermal environment. Temperature is controlled by using internal thermal louvers that regulate the rate at which the heat load from electronic equipment is transmitted to the outer surface for dumping to space.

  15. Fitting polytomous Rasch models in SAS

    DEFF Research Database (Denmark)

    Christensen, Karl Bang

    2006-01-01

    The item parameters of a polytomous Rasch model can be estimated using marginal and conditional approaches. This paper describes how this can be done in SAS (V8.2) for three item parameter estimation procedures: marginal maximum likelihood estimation, conditional maximum likelihood estimation......, and pairwise conditional estimation. The use of the procedures for extensions of the Rasch model is also discussed. The accuracy of the methods are evaluated using a simulation study....

  16. Design and analysis of experiments with SAS

    CERN Document Server

    Lawson, John

    2010-01-01

    IntroductionStatistics and Data Collection Beginnings of Statistically Planned Experiments Definitions and Preliminaries Purposes of Experimental Design Types of Experimental Designs Planning Experiments Performing the Experiments Use of SAS SoftwareCompletely Randomized Designs with One Factor Introduction Replication and Randomization A Historical Example Linear Model for Completely Randomized Design (CRD) Verifying Assumptions of the Linear Model Analysis Strategies When Assumptions Are Violated Determining the Number of Replicates Comparison of Treatments after the F-TestFactorial Designs

  17. Colombian Safe Guide S.A.S

    OpenAIRE

    2012-01-01

    Colombian Safe Guide S.A.S. es una compañía de servicios de asesoramiento y acompañamiento a los visitantes extranjeros que vienen a la ciudad de Bogotá. Funciona a través de una página web, que facilitan a sus clientes la obtención de todos los servicios necesarios durante su estadía, en un solo lugar. El principal objetivo es proporcionar nuevas alternativas de servicios de asesoramiento, capitalizando la compañía bajo el cumplimiento del objetivo y cuota del mercado propuesta por la compañ...

  18. The SAS-3 attitude control system

    Science.gov (United States)

    Mobley, F. F.; Konigsberg, R.; Fountain, G. H.

    1975-01-01

    SAS-3 uses a reaction wheel to provide torque to control the spin rate. If the wheel speed becomes too great or too small, it must be restored to its nominal rate by momentum dumping which is done by magnetic torquing against the earth's magnetic field by the satellite's magnetic coils. A small rate-integrating gyro is used to sense the spin rate so that closed loop control of the spin rate can be achieved. These various systems are described in detail including the reaction wheel system, the gyro system, along with control modes (spin rate control and the star lock mode).

  19. SAS-Expander and Its Realization%SAS-Expander及其实现

    Institute of Scientific and Technical Information of China (English)

    王宇

    2009-01-01

    SAS(Serial Attached SCSI)即串行SCSI技术,是一种磁盘连接技术.而Expander本质上就是SAS交换机,可以将多个SAS连接到有限数量的主机端口上.这里主要介绍了通过MAX-IM公司的VSC7154实现SAS-Expander磁盘阵列柜.此阵列柜机构部件依据SBB规范实现.

  20. Direct binding of SAS-6 to ZYG-1 recruits SAS-6 to the mother centriole for cartwheel assembly.

    Science.gov (United States)

    Lettman, Molly M; Wong, Yao Liang; Viscardi, Valeria; Niessen, Sherry; Chen, Sheng-Hong; Shiau, Andrew K; Zhou, Huilin; Desai, Arshad; Oegema, Karen

    2013-05-13

    Assembly of SAS-6 dimers to form the centriolar cartwheel requires the ZYG-1/Plk4 kinase. Here, we show that ZYG-1 recruits SAS-6 to the mother centriole independently of its kinase activity; kinase activity is subsequently required for cartwheel assembly. We identify a direct interaction between ZYG-1 and the SAS-6 coiled coil that explains its kinase activity-independent function in SAS-6 recruitment. Perturbing this interaction, or the interaction between an adjacent segment of the SAS-6 coiled coil and SAS-5, prevented SAS-6 recruitment and cartwheel assembly. SAS-6 mutants with alanine substitutions in a previously described ZYG-1 target site or in 37 other residues, either phosphorylated by ZYG-1 in vitro or conserved in closely related nematodes, all supported cartwheel assembly. We propose that ZYG-1 binding to the SAS-6 coiled coil recruits the SAS-6-SAS-5 complex to the mother centriole, where a ZYG-1 kinase activity-dependent step, whose target is unlikely to be SAS-6, triggers cartwheel assembly.

  1. Composites reinforcement by rods: a SAS study

    Energy Technology Data Exchange (ETDEWEB)

    Urban, V. [ESRF, BP220, 38043 Grenoble Cedex (France); Botti, A.; Pyckhout-Hintzen, W.; Richter, D. [IFF-Forschungszentrum Juelich, 52425 Juelich (Germany); Straube, E. [University of Halle, FB Physik, 06099 Halle (Germany)

    2002-07-01

    The mechanical properties of composites are governed by size, shape and dispersion degree of so-called reinforcing particles. Polymeric fillers based on thermodynamically driven microphase separation of block copolymers offer the opportunity to study a model system of controlled rod-like filler particles. We chose a triblock copolymer (PBPSPB) and carried out SAS measurements with both X-rays and neutrons, in order to characterize separately the hard phase and the cross-linked PB matrix. The properties of the material depend strongly on the way that stress is carried and transferred between the soft matrix and the hard fibers. The failure of the strain-amplification concept and the change of topological contributions to the free energy and scattering factor have to be addressed. In this respect the composite shows a similarity to a two-network system, i.e. interpenetrating rubber and rod-like filler networks. (orig.)

  2. Composites reinforcement by rods a SAS study

    CERN Document Server

    Urban, V; Pyckhout-Hintzen, W; Richter, D; Straube, E

    2002-01-01

    The mechanical properties of composites are governed by size, shape and dispersion degree of so-called reinforcing particles. Polymeric fillers based on thermodynamically driven microphase separation of block copolymers offer the opportunity to study a model system of controlled rod-like filler particles. We chose a triblock copolymer (PBPSPB) and carried out SAS measurements with both X-rays and neutrons, in order to characterize separately the hard phase and the cross-linked PB matrix. The properties of the material depend strongly on the way that stress is carried and transferred between the soft matrix and the hard fibers. The failure of the strain-amplification concept and the change of topological contributions to the free energy and scattering factor have to be addressed. In this respect the composite shows a similarity to a two-network system, i.e. interpenetrating rubber and rod-like filler networks. (orig.)

  3. Regression modeling methods, theory, and computation with SAS

    CERN Document Server

    Panik, Michael

    2009-01-01

    Regression Modeling: Methods, Theory, and Computation with SAS provides an introduction to a diverse assortment of regression techniques using SAS to solve a wide variety of regression problems. The author fully documents the SAS programs and thoroughly explains the output produced by the programs.The text presents the popular ordinary least squares (OLS) approach before introducing many alternative regression methods. It covers nonparametric regression, logistic regression (including Poisson regression), Bayesian regression, robust regression, fuzzy regression, random coefficients regression,

  4. SAS and R data management, statistical analysis, and graphics

    CERN Document Server

    Kleinman, Ken

    2014-01-01

    An Up-to-Date, All-in-One Resource for Using SAS and R to Perform Frequent TasksThe first edition of this popular guide provided a path between SAS and R using an easy-to-understand, dictionary-like approach. Retaining the same accessible format, SAS and R: Data Management, Statistical Analysis, and Graphics, Second Edition explains how to easily perform an analytical task in both SAS and R, without having to navigate through the extensive, idiosyncratic, and sometimes unwieldy software documentation. The book covers many common tasks, such as data management, descriptive summaries, inferentia

  5. Adaptive beamforming for low frequency SAS imagery and bathymetry

    NARCIS (Netherlands)

    Hayes, M.P.; Hunter, A.J.

    2012-01-01

    Synthetic aperture side-scan sonar (SAS) is a mature technology for high-resolution sea floor imaging [1]. Interferometric synthetic aperture sonars (InSAS) use additional hydrophones in a vertical array for bathymetric mapping [2]. This has created high-resolution bathymetry in deep water environme

  6. Adaptive beamforming for low frequency SAS imagery and bathymetry

    NARCIS (Netherlands)

    Hayes, M.P.; Hunter, A.J.

    2012-01-01

    Synthetic aperture side-scan sonar (SAS) is a mature technology for high-resolution sea floor imaging [1]. Interferometric synthetic aperture sonars (InSAS) use additional hydrophones in a vertical array for bathymetric mapping [2]. This has created high-resolution bathymetry in deep water

  7. Hotelli Radisson SAS mantra : jah, ma saan! / Kai Vare

    Index Scriptorium Estoniae

    Vare, Kai, 1968-

    2004-01-01

    Radisson SAS hotell Tallinnas on kliendirahulolu-uuringute järgi keti hotellide seas esimeste hulgas. Hotelli direktor Kaido Ojaperv ja müügijuht Ann-Kai Tõrs Radisson SAS-i standarditest, kliendi sajaprotsendilise rahulolu tagamise põhimõtetest, personali valikust, koolitusest. Kommenteerib Sandra Dimitrovich

  8. A Review of Seismicity in 2008

    Institute of Scientific and Technical Information of China (English)

    Li Gang; Liu Jie; Yu Surong

    2009-01-01

    @@ 1 SURVEY OF GLOBE SEISMICITY IN 2008 A total of 19 strong earthquakes with Ms≥7.0 occurred in the world in 2008 according to the Chinese Seismic Station Network (Table 1 ). The strongest earthquake was the Wenchuan earthquake with Ms8.0 on May 12,2008 (Fig.1). Earthquake frequency was apparently lower and the energy release remarkably attenuated in 2008, compared to seismicity in 2007. The characteristics of seismicity are as follows:

  9. SAS-6 coiled-coil structure and interaction with SAS-5 suggest a regulatory mechanism in C. elegans centriole assembly.

    Science.gov (United States)

    Qiao, Renping; Cabral, Gabriela; Lettman, Molly M; Dammermann, Alexander; Dong, Gang

    2012-11-14

    The centriole is a conserved microtubule-based organelle essential for both centrosome formation and cilium biogenesis. Five conserved proteins for centriole duplication have been identified. Two of them, SAS-5 and SAS-6, physically interact with each other and are codependent for their targeting to procentrioles. However, it remains unclear how these two proteins interact at the molecular level. Here, we demonstrate that the short SAS-5 C-terminal domain (residues 390-404) specifically binds to a narrow central region (residues 275-288) of the SAS-6 coiled coil. This was supported by the crystal structure of the SAS-6 coiled-coil domain (CCD), which, together with mutagenesis studies, indicated that the association is mediated by synergistic hydrophobic and electrostatic interactions. The crystal structure also shows a periodic charge pattern along the SAS-6 CCD, which gives rise to an anti-parallel tetramer. Overall, our findings establish the molecular basis of the specific interaction between SAS-5 and SAS-6, and suggest that both proteins individually adopt an oligomeric conformation that is disrupted upon the formation of the hetero-complex to facilitate the correct assembly of the nine-fold symmetric centriole.

  10. SAS and R data management, statistical analysis, and graphics

    CERN Document Server

    Kleinman, Ken

    2009-01-01

    An All-in-One Resource for Using SAS and R to Carry out Common TasksProvides a path between languages that is easier than reading complete documentationSAS and R: Data Management, Statistical Analysis, and Graphics presents an easy way to learn how to perform an analytical task in both SAS and R, without having to navigate through the extensive, idiosyncratic, and sometimes unwieldy software documentation. The book covers many common tasks, such as data management, descriptive summaries, inferential procedures, regression analysis, and the creation of graphics, along with more complex applicat

  11. Substrate Activity Screening (SAS) and Related Approaches in Medicinal Chemistry.

    Science.gov (United States)

    Gladysz, Rafaela; Lambeir, Anne-Marie; Joossens, Jurgen; Augustyns, Koen; Van der Veken, Pieter

    2016-03-04

    Substrate activity screening (SAS) was presented a decade ago by Ellman and co-workers as a straightforward methodology for the identification of fragment-sized building blocks for enzyme inhibitors. Ever since, SAS and variations derived from it have been successfully applied to the discovery of inhibitors of various families of enzymatically active drug targets. This review covers key achievements and challenges of SAS and related methodologies, including the modified substrate activity screening (MSAS) approach. Special attention is given to the kinetic and thermodynamic aspects of these methodologies, as a thorough understanding thereof is crucial for successfully transforming the identified fragment-sized hits into potent inhibitors.

  12. Usual Dietary Intakes: SAS Macros for the NCI Method

    Science.gov (United States)

    SAS macros are currently available to facilitate modeling of a single dietary component, whether consumed daily or episodically; ratios of two dietary components that are consumed nearly every day; multiple dietary components, whether consumed daily or episodically.

  13. Breast Cancer Risk Assessment SAS Macro (Gail Model)

    Science.gov (United States)

    A SAS macro (commonly referred to as the Gail Model) that projects absolute risk of invasive breast cancer according to NCI’s Breast Cancer Risk Assessment Tool (BCRAT) algorithm for specified race/ethnic groups and age intervals.

  14. Islandlased tahavad SAS-i Skandinaavia turult kukutada / Mikk Salu

    Index Scriptorium Estoniae

    Salu, Mikk, 1975-

    2006-01-01

    Islandlastele kuuluv investeerimisfirma FL Grupp koondab lennufirmasid, et haarata liidrirolli Põhjala lennunduses. Lisad: Island; Islandi rikkaim mees; Uus põlvkond. Diagrammid: Islandi lennuärimehed versus SAS

  15. Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland

    KAUST Repository

    Bethmann, Falko

    2012-08-01

    We investigate attenuation (Q−1) of sediments of 2.5–3.5km thickness underneath the city of Basel, Switzerland. We use recordings of 195 induced events that were obtained during and after the stimulation of a reservoir for a Deep Heat Mining Project in 2006 and 2007. The data set is ideally suited to estimate Q as all events are confined to a small source volume and were recorded by a dense surface network as well as six borehole sensors at various depths. The deepest borehole sensor is positioned at a depth of 2.7km inside the crystalline basement at a mean hypocentral distance of 1.8km. This allows us to measure Q for frequencies between 10 and 130 Hz. We apply two different methods to estimate Q. First, we use a standard spectral ratio technique to obtain Q, and as a second measure we estimate Q in the time domain, by convolving signals recorded by the deepest sensor with a Q operator and then comparing the convolved signals to recordings at the shallower stations. Both methods deliver comparable values for Q. We also observe similar attenuation for P- and S- waves (QP∼QS). As expected, Q increases with depth, but with values around 30–50, it is low even for the consolidated Permian and Mesozoic sediments between 500 and 2700 m.

  16. Structure of the SAS-6 cartwheel hub from Leishmania major.

    Science.gov (United States)

    van Breugel, Mark; Wilcken, Rainer; McLaughlin, Stephen H; Rutherford, Trevor J; Johnson, Christopher M

    2014-01-01

    Centrioles are cylindrical cell organelles with a ninefold symmetric peripheral microtubule array that is essential to template cilia and flagella. They are built around a central cartwheel assembly that is organized through homo-oligomerization of the centriolar protein SAS-6, but whether SAS-6 self-assembly can dictate cartwheel and thereby centriole symmetry is unclear. Here we show that Leishmania major SAS-6 crystallizes as a 9-fold symmetric cartwheel and provide the X-ray structure of this assembly at a resolution of 3.5 Å. We furthermore demonstrate that oligomerization of Leishmania SAS-6 can be inhibited by a small molecule in vitro and provide indications for its binding site. Our results firmly establish that SAS-6 can impose cartwheel symmetry on its own and indicate how this process might occur mechanistically in vivo. Importantly, our data also provide a proof-of-principle that inhibition of SAS-6 oligomerization by small molecules is feasible. DOI: http://dx.doi.org/10.7554/eLife.01812.001.

  17. Q value of anelastic S-wave attenuation in Yunnan region

    Institute of Scientific and Technical Information of China (English)

    SU You-jin; LIU Jie; ZHENG Si-hua; LIU Li-fang; FU Hong; XU Yan

    2006-01-01

    @@ The study of seismic attenuation property is a major subject in seismology. Seismic waves recorded by seismic stations (seismographs) contain source effect, seismic wave propagation effect, site response of seismic stations and instrumental response. The path effect of seismic wave propagation, site response of seismic stations and instrumental response must be taken out in the study of source property with seismic data. The path effect of seismic wave propagation (seismic attenuation) involves an important influential factor, the anelastic attenuation of medium, which is measured with quality factor Q, apart from geometric attenuation with the distance. As a basic physical parameter of the Earth medium, Q value is essential for quantitative study of earthquakes and source property (e.g. determination of source parameters), which is widely used in earthquake source physics and engineering seismology.

  18. Seismic internal multiple attenuation based on constructing virtual events%基于构建虚同相轴压制地震层间多次波

    Institute of Scientific and Technical Information of China (English)

    吴静; 吴志强; 胡天跃; 何玉华; 王璞; 闫桂京; 李琳

    2013-01-01

    基于构建虚同相轴来估计层间多次波的方法是克希霍夫积分表示定理的一个延伸发展.本文通过构建虚地震同相轴巧妙地将散射点从地下移到了表面,利用表面的散射点来预测层间多次波.由于预测与实际地震记录中的层间多次波振幅存在偏差,采用了多道的L1范数匹配算法来实现真振幅的多次波压制.对简单模型和南黄海地质模型的数据处理实例验证了本文研究方法的正确性和有效性.%The method of estimating internal multiple based on constructing virtual events is an extended result of Kirchhoff integral representation theorem. In this paper, the downward reflection point is shifted from subsurface to free surface skillfully by constructing virtual events, and then the internal multiple can be predicted simply by using surface scattering points without subsurface information. After estimation of multiple, a multi-channel L1 norm matching method is used to implement true amplitude multiple subtraction. In addition, the examples of seismic data processing results of a simple model and a South Yellow Sea geological model verify the accuracy and effectiveness of the method developed in this paper.

  19. A SAS Package for Logistic Two-Phase Studies

    Directory of Open Access Journals (Sweden)

    Walter Schill

    2014-04-01

    Full Text Available Two-phase designs, in which for a large study a dichotomous outcome and partial or proxy information on risk factors is available, whereas precise or complete measurements on covariates have been obtained only in a stratified sub-sample, extend the standard case-control design and have been proven useful in practice. The application of two-phase designs, however, seems to be hampered by the lack of appropriate, easy-to-use software. This paper introduces sas-twophase-package, a collection of SAS-macros, to fulfill this task. sas-twophase-package implements weighted likelihood, pseudo likelihood and semi- parametric maximum likelihood estimation via the EM algorithm and via profile likelihood in two-phase settings with dichotomous outcome and a given stratification.

  20. Social Anxiety Scale for Adolescents (SAS-A) Short Form.

    Science.gov (United States)

    Nelemans, Stefanie A; Meeus, Wim H J; Branje, Susan J T; Van Leeuwen, Karla; Colpin, Hilde; Verschueren, Karine; Goossens, Luc

    2017-01-01

    In this study, we examined the longitudinal measurement invariance of a 12-item short version of the Social Anxiety Scale for Adolescents (SAS-A) in two 4-year longitudinal community samples ( Nsample 1 = 815, Mage T1 = 13.38 years; Nsample 2 = 551, Mage T1 = 14.82 years). Using confirmatory factor analyses, we found strict longitudinal measurement invariance for the three-factor structure of the SAS-A across adolescence, across samples, and across gender. Some developmental changes in social anxiety were found from early to mid-adolescence, as well as gender differences across adolescence. These findings suggest that the short version of the SAS-A is a developmentally appropriate instrument that can be used effectively to examine adolescent social anxiety development.

  1. SAS-2 galactic gamma-ray results. 1: Diffuse emission

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Lamb, R. C.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    Continuing analysis of the data from the SAS-2 high energy gamma ray experiment has produced an improved picture of the sky at photon energies above 35 MeV. On a large scale, the diffuse emission from the galactic plane is the dominant feature observed by SAS-2. This galactic plane emission is most intense between galactic longitudes 310 deg and 45 deg, corresponding to a region within 7 kpc of the galactic center. Within the high-intensity region, SAS-2 observes peaks around galactic longitudes 315, 330, 345, 0, and 35 deg. These peaks appear to be correlated with galactic features and components such as molecular hydrogen, atomic hydrogen, magnetic fields, cosmic-ray concentrations, and photon fields.

  2. Development and validation of a smartphone addiction scale (SAS.

    Directory of Open Access Journals (Sweden)

    Min Kwon

    Full Text Available OBJECTIVE: The aim of this study was to develop a self-diagnostic scale that could distinguish smartphone addicts based on the Korean self-diagnostic program for Internet addiction (K-scale and the smartphone's own features. In addition, the reliability and validity of the smartphone addiction scale (SAS was demonstrated. METHODS: A total of 197 participants were selected from Nov. 2011 to Jan. 2012 to accomplish a set of questionnaires, including SAS, K-scale, modified Kimberly Young Internet addiction test (Y-scale, visual analogue scale (VAS, and substance dependence and abuse diagnosis of DSM-IV. There were 64 males and 133 females, with ages ranging from 18 to 53 years (M = 26.06; SD = 5.96. Factor analysis, internal-consistency test, t-test, ANOVA, and correlation analysis were conducted to verify the reliability and validity of SAS. RESULTS: Based on the factor analysis results, the subscale "disturbance of reality testing" was removed, and six factors were left. The internal consistency and concurrent validity of SAS were verified (Cronbach's alpha = 0.967. SAS and its subscales were significantly correlated with K-scale and Y-scale. The VAS of each factor also showed a significant correlation with each subscale. In addition, differences were found in the job (p<0.05, education (p<0.05, and self-reported smartphone addiction scores (p<0.001 in SAS. CONCLUSIONS: This study developed the first scale of the smartphone addiction aspect of the diagnostic manual. This scale was proven to be relatively reliable and valid.

  3. Want independent validation and assurance? Ask for a SAS-70.

    Science.gov (United States)

    Boutin, Christopher C

    2008-08-01

    The AICPA's Statement on Auditing Standards No.70, Service Organizations addresses CPA audits of service providers conducted to verify that a provider has adequate controls over its operations. Hospitals should request a SAS-70, the report produced by such an audit, from all of their third-party service providers. SAS-70s can be issued for a specific date or for a six-month period, and they typically consist of three sections: a CPA opinion, a description of controls, and information about the design of the controls.

  4. Observations of A0620-00 by SAS-3

    Science.gov (United States)

    Bradt, H.; Matilsky, T.

    1976-01-01

    The transient X-ray source A0620-00 was observed by the SAS-3 group with the SAS-3 X-ray observatory. At maximum X-ray luminosity limits of 2% were placed on periodic variations from 0.2 ms - 2,000 sec. A precise position was obtained with the rotating modulation collimator. This led directly to radio and optical identification by groups at the NRAO, Arecibo, and McGraw Hill Observatories. The low energy (0.15-0.9 keV) system was pointed at the source, and a spectrum was derived. Hardness ratios are presented, as well as detailed light curves.

  5. Traitement des données par le logiciel SAS: introduction au module de base

    OpenAIRE

    Carletti, Isabelle; Prevot, Hugues

    2006-01-01

    Cette note constitue une introduction au module de base SAS. Après un bref aperçu de l'environnement de travail SAS et des principes du langage SAS, les étapes DATA et PROC d'un programme SAS sont exposées en plus en détails.

  6. SAS Radisson esitab Tallinnale väljakutse / Tõnis Arnover

    Index Scriptorium Estoniae

    Arnover, Tõnis, 1952-

    2000-01-01

    Tallinna Radisson SAS hotelli juht T. Bodin on kindel, et suudab pakkuda tipphotellile kohast teenindus. Vt. samas Mägus, Feliks. Hinnasõda hotellide vahel jääb ära. Ilmunud ka: Delovõje Vedomosti 1. nov. lk. 20-21

  7. Tubulin nucleotide status controls Sas-4-dependent pericentriolar material recruitment.

    Science.gov (United States)

    Gopalakrishnan, Jayachandran; Chim, Yiu-Cheung Frederick; Ha, Andrew; Basiri, Marcus L; Lerit, Dorothy A; Rusan, Nasser M; Avidor-Reiss, Tomer

    2012-08-01

    Regulated centrosome biogenesis is required for accurate cell division and for maintaining genome integrity. Centrosomes consist of a centriole pair surrounded by a protein network known as pericentriolar material (PCM). PCM assembly is a tightly regulated, critical step that determines the size and capability of centrosomes. Here, we report a role for tubulin in regulating PCM recruitment through the conserved centrosomal protein Sas-4. Tubulin directly binds to Sas-4; together they are components of cytoplasmic complexes of centrosomal proteins. A Sas-4 mutant, which cannot bind tubulin, enhances centrosomal protein complex formation and has abnormally large centrosomes with excessive activity. These results suggest that tubulin negatively regulates PCM recruitment. Whereas tubulin-GTP prevents Sas-4 from forming protein complexes, tubulin-GDP promotes it. Thus, the regulation of PCM recruitment by tubulin depends on its GTP/GDP-bound state. These results identify a role for tubulin in regulating PCM recruitment independent of its well-known role as a building block of microtubules. On the basis of its guanine-bound state, tubulin can act as a molecular switch in PCM recruitment.

  8. Using SAS PROC MCMC for Item Response Theory Models

    Science.gov (United States)

    Ames, Allison J.; Samonte, Kelli

    2015-01-01

    Interest in using Bayesian methods for estimating item response theory models has grown at a remarkable rate in recent years. This attentiveness to Bayesian estimation has also inspired a growth in available software such as WinBUGS, R packages, BMIRT, MPLUS, and SAS PROC MCMC. This article intends to provide an accessible overview of Bayesian…

  9. A SAS Interface for Bayesian Analysis with WinBUGS

    Science.gov (United States)

    Zhang, Zhiyong; McArdle, John J.; Wang, Lijuan; Hamagami, Fumiaki

    2008-01-01

    Bayesian methods are becoming very popular despite some practical difficulties in implementation. To assist in the practical application of Bayesian methods, we show how to implement Bayesian analysis with WinBUGS as part of a standard set of SAS routines. This implementation procedure is first illustrated by fitting a multiple regression model…

  10. A SAS/IML algorithm for an exact permutation test

    Directory of Open Access Journals (Sweden)

    Neuhäuser, Markus

    2009-03-01

    Full Text Available An algorithm written in SAS/IML is presented that can perform an exact permutation test for a two-sample comparison. All possible permutations are considered. The Baumgartner-Weiß-Schindler statistic is exemplarily used as the test statistic for the permutation test.

  11. Delineation of seismic source zones based on seismicity parameters and probabilistic evaluation of seismic hazard using logic tree approach

    Indian Academy of Sciences (India)

    K S Vipin; T G Sitharam

    2013-06-01

    The delineation of seismic source zones plays an important role in the evaluation of seismic hazard. In most of the studies the seismic source delineation is done based on geological features. In the present study, an attempt has been made to delineate seismic source zones in the study area (south India) based on the seismicity parameters. Seismicity parameters and the maximum probable earthquake for these source zones were evaluated and were used in the hazard evaluation. The probabilistic evaluation of seismic hazard for south India was carried out using a logic tree approach. Two different types of seismic sources, linear and areal, were considered in the present study to model the seismic sources in the region more precisely. In order to properly account for the attenuation characteristics of the region, three different attenuation relations were used with different weightage factors. Seismic hazard evaluation was done for the probability of exceedance (PE) of 10% and 2% in 50 years. The spatial variation of rock level peak horizontal acceleration (PHA) and spectral acceleration (Sa) values corresponding to return periods of 475 and 2500 years for the entire study area are presented in this work. The peak ground acceleration (PGA) values at ground surface level were estimated based on different NEHRP site classes by considering local site effects.

  12. SAS- Semantic Annotation Service for Geoscience resources on the web

    Science.gov (United States)

    Elag, M.; Kumar, P.; Marini, L.; Li, R.; Jiang, P.

    2015-12-01

    There is a growing need for increased integration across the data and model resources that are disseminated on the web to advance their reuse across different earth science applications. Meaningful reuse of resources requires semantic metadata to realize the semantic web vision for allowing pragmatic linkage and integration among resources. Semantic metadata associates standard metadata with resources to turn them into semantically-enabled resources on the web. However, the lack of a common standardized metadata framework as well as the uncoordinated use of metadata fields across different geo-information systems, has led to a situation in which standards and related Standard Names abound. To address this need, we have designed SAS to provide a bridge between the core ontologies required to annotate resources and information systems in order to enable queries and analysis over annotation from a single environment (web). SAS is one of the services that are provided by the Geosematnic framework, which is a decentralized semantic framework to support the integration between models and data and allow semantically heterogeneous to interact with minimum human intervention. Here we present the design of SAS and demonstrate its application for annotating data and models. First we describe how predicates and their attributes are extracted from standards and ingested in the knowledge-base of the Geosemantic framework. Then we illustrate the application of SAS in annotating data managed by SEAD and annotating simulation models that have web interface. SAS is a step in a broader approach to raise the quality of geoscience data and models that are published on the web and allow users to better search, access, and use of the existing resources based on standard vocabularies that are encoded and published using semantic technologies.

  13. Procedures for computing site seismicity

    Science.gov (United States)

    Ferritto, John

    1994-02-01

    This report was prepared as part of the Navy's Seismic Hazard Mitigation Program. The Navy has numerous bases located in seismically active regions throughout the world. Safe effective design of waterfront structures requires determining expected earthquake ground motion. The Navy's problem is further complicated by the presence of soft saturated marginal soils that can significantly amplify the levels of seismic shaking as evidenced in the 1989 Loma Prieta earthquake. The Naval Facilities Engineering Command's seismic design manual, NAVFAC P355.l, requires a probabilistic assessment of ground motion for design of essential structures. This report presents the basis for the Navy's Seismic Hazard Analysis procedure that was developed and is intended to be used with the Seismic Hazard Analysis computer program and user's manual. This report also presents data on geology and seismology to establish the background for the seismic hazard model developed. The procedure uses the historical epicenter data base and available geologic data, together with source models, recurrence models, and attenuation relationships to compute the probability distribution of site acceleration and an appropriate spectra. This report discusses the developed stochastic model for seismic hazard evaluation and the associated research.

  14. Near-Surface Attenuation and Velocity Structures in Taiwan from Wellhead and Borehole Recordings Comparisons

    National Research Council Canada - National Science Library

    Wang, Yu-Ju; Ma, Kuo-Fong; Wu, Shao-Kai; Hsu, Hsuan-Jui; Hsiao, Wen-Chi

    2016-01-01

    By analyzing the data from 28 seismic borehole stations deployed by the Central Weather Bureau Seismic Network throughout Taiwan from 2007 to 2014, we estimated the near-surface velocity (Vp and Vs) and attenuation (Qp and Qs...

  15. A SAS-6-like protein suggests that the Toxoplasma conoid complex evolved from flagellar components.

    Science.gov (United States)

    de Leon, Jessica Cruz; Scheumann, Nicole; Beatty, Wandy; Beck, Josh R; Tran, Johnson Q; Yau, Candace; Bradley, Peter J; Gull, Keith; Wickstead, Bill; Morrissette, Naomi S

    2013-07-01

    SAS-6 is required for centriole biogenesis in diverse eukaryotes. Here, we describe a novel family of SAS-6-like (SAS6L) proteins that share an N-terminal domain with SAS-6 but lack coiled-coil tails. SAS6L proteins are found in a subset of eukaryotes that contain SAS-6, including diverse protozoa and green algae. In the apicomplexan parasite Toxoplasma gondii, SAS-6 localizes to the centriole but SAS6L is found above the conoid, an enigmatic tubulin-containing structure found at the apex of a subset of alveolate organisms. Loss of SAS6L causes reduced fitness in Toxoplasma. The Trypanosoma brucei homolog of SAS6L localizes to the basal-plate region, the site in the axoneme where the central-pair microtubules are nucleated. When endogenous SAS6L is overexpressed in Toxoplasma tachyzoites or Trypanosoma trypomastigotes, it forms prominent filaments that extend through the cell cytoplasm, indicating that it retains a capacity to form higher-order structures despite lacking a coiled-coil domain. We conclude that although SAS6L proteins share a conserved domain with SAS-6, they are a functionally distinct family that predates the last common ancestor of eukaryotes. Moreover, the distinct localization of the SAS6L protein in Trypanosoma and Toxoplasma adds weight to the hypothesis that the conoid complex evolved from flagellar components.

  16. CTTITEM: SAS macro and SPSS syntax for classical item analysis.

    Science.gov (United States)

    Lei, Pui-Wa; Wu, Qiong

    2007-08-01

    This article describes the functions of a SAS macro and an SPSS syntax that produce common statistics for conventional item analysis including Cronbach's alpha, item difficulty index (p-value or item mean), and item discrimination indices (D-index, point biserial and biserial correlations for dichotomous items and item-total correlation for polytomous items). These programs represent an improvement over the existing SAS and SPSS item analysis routines in terms of completeness and user-friendliness. To promote routine evaluations of item qualities in instrument development of any scale, the programs are available at no charge for interested users. The program codes along with a brief user's manual that contains instructions and examples are downloadable from suen.ed.psu.edu/-pwlei/plei.htm.

  17. SAS/QC在统计质量管理中的功能与应用

    Institute of Scientific and Technical Information of China (English)

    钟英莲

    2008-01-01

    在统计教学与实践中,对SAS系统的开发应用较多的是SAS/BASE、SAS/STAT、SAS/ETS等软件,而对于SAS/QC软件的开发应用尚属少见。本文将概括性地介绍SAS/QC软件在质量管理中的功能和作用,通过案例介绍SAS/QC在质量控制中的具体应用。

  18. Genome sequencing and annotation of Proteus sp. SAS71

    Directory of Open Access Journals (Sweden)

    Samy Selim

    2015-12-01

    Full Text Available We report draft genome sequence of Proteus sp. strain SAS71, isolated from water spring in Aljouf region, Saudi Arabia. The draft genome size is 3,037,704 bp with a G + C content of 39.3% and contains 6 rRNA sequence (single copies of 5S, 16S & 23S rRNA. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. LDIU00000000.

  19. Combination of functional MRI with SAS and MRA

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Masayuki; Takeshita, Shinichirou; Kutsuna, Munenori; Akimitsu, Tomohide; Arita, Kazunori; Kurisu, Kaoru [Hiroshima Univ. (Japan). School of Medicine

    1999-02-01

    For presurgical diagnosis of brain surface, combination of functional MRI (fMRI) with the MR angiography was examined. This method could visualize brain bay, convolution and vein as index of surface. Five normal adults (male, mean age: 28-year-old) and 7 patients with brain tumor on the main locus to surface (male: 4, female: 3, mean age: 52.3-year-old) were studied. fMRI was performed by SPGR method (TR 70, TE 40, flip angle 60, one slice, thickness 10 mm, FOV 20 cm, matrix 128 x 128). The brain surface was visualized by SAS (surface anatomy scanning). SAS was performed by FSE method (TR 6000, TE 200, echo train 16, thickness 20 mm, slice 3, NEX 2). Cortical veins near superior sagittal sinus were visualized by MRA with 2D-TOF method (TR 50, TE 20, flip angle 60, thickness 2 mm, slice 28, NEX 1). These images were superimposed and functional image of peripheral sensorimotor region was evaluated anatomically. In normal adults, high signal was visualized at another side of near sensorimotor region at 8 of 10 sides. All high signal area of fMRI agreed with cortical vein near sensorimotor region that was visualized by MRA. In patients with brain tumor, signal was visualized at another side of sensorimotor region of tumor without 2 cases with palsy. In another side of tumor, signal of fMRI was visualized in 5 of 7 cases. The tumor was visualized as opposite low signal field in SAS. Locational relation between tumor and brain surface and brain function was visualized distinctly by combination of MRA, SAS and MRA. This method could become useful for presurgical diagnosis. (K.H.)

  20. Quality assurance management plan (QAPP) special analytical support (SAS)

    Energy Technology Data Exchange (ETDEWEB)

    LOCKREM, L.L.

    1999-05-20

    It is the policy of Special Analytical Support (SAS) that the analytical aspects of all environmental data generated and processed in the laboratory, subject to the Environmental Protection Agency (EPA), U.S. Department of Energy or other project specific requirements, be of known and acceptable quality. It is the intention of this QAPP to establish and assure that an effective quality controlled management system is maintained in order to meet the quality requirements of the intended use(s) of the data.

  1. Implementing the Law of Sines to solve SAS triangles

    CERN Document Server

    Zelator, Konstantine

    2010-01-01

    By "solving a triangle", one refers to determining the three sidelengths and the three angles, based on given information.Depending on the specific information, one or more triangles may satisfy the requirements of the given information.In the SAS case, two of sidelengths are given, as well as the angle contained by the two sides.According to Euclidean Geometry, such a triangle must be unique. In reference [1], and pretty much in standard trigonometry and precalculus texts,the Law of Cosines is employed in solving a SAS triangle. In this work we use an alternative approach by using the Law of Cosines.In Section 2, we list some basic trigonometric identities and in Section 3 we prove a lemma which is used in Section4. In Section4, we demonstrate the use of the Law of Sines in solving an SAS triangle. In Section 5 we offer three examples in detail; the last one being more general in nature.

  2. SPSS and SAS programming for the testing of mediation models.

    Science.gov (United States)

    Dudley, William N; Benuzillo, Jose G; Carrico, Mineh S

    2004-01-01

    Mediation modeling can explain the nature of the relation among three or more variables. In addition, it can be used to show how a variable mediates the relation between levels of intervention and outcome. The Sobel test, developed in 1990, provides a statistical method for determining the influence of a mediator on an intervention or outcome. Although interactive Web-based and stand-alone methods exist for computing the Sobel test, SPSS and SAS programs that automatically run the required regression analyses and computations increase the accessibility of mediation modeling to nursing researchers. To illustrate the utility of the Sobel test and to make this programming available to the Nursing Research audience in both SAS and SPSS. The history, logic, and technical aspects of mediation testing are introduced. The syntax files sobel.sps and sobel.sas, created to automate the computation of the regression analysis and test statistic, are available from the corresponding author. The reported programming allows the user to complete mediation testing with the user's own data in a single-step fashion. A technical manual included with the programming provides instruction on program use and interpretation of the output. Mediation modeling is a useful tool for describing the relation between three or more variables. Programming and manuals for using this model are made available.

  3. Attenuation of Seismic Waves at Regional Distances

    Science.gov (United States)

    1984-11-27

    States (SALMON, GASBUOG, RULISON and RIO BLANCA) and in the French Sahara ( SAPHIR and RUBIS). The hard-rook ITS calibration curve, when applied to these...so that two of the explosions, SAPHIR and RUBIS, had measure- able Lg-wave amplitudes. Figure 4 gives an example of Lg waves of SAPHIR recorded at...for RUBIS and SAPHIR . Station HLW is in Egypt, and SDB in Angola. Both shots were in granite. For the Nevada explosions SHOAL and PILEDRIVER, also in

  4. Final Report: Seismic Hazard Assessment at the PGDP

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhinmeng [KY Geological Survey, Univ of KY

    2007-06-01

    Selecting a level of seismic hazard at the Paducah Gaseous Diffusion Plant for policy considerations and engineering design is not an easy task because it not only depends on seismic hazard, but also on seismic risk and other related environmental, social, and economic issues. Seismic hazard is the main focus. There is no question that there are seismic hazards at the Paducah Gaseous Diffusion Plant because of its proximity to several known seismic zones, particularly the New Madrid Seismic Zone. The issues in estimating seismic hazard are (1) the methods being used and (2) difficulty in characterizing the uncertainties of seismic sources, earthquake occurrence frequencies, and ground-motion attenuation relationships. This report summarizes how input data were derived, which methodologies were used, and what the hazard estimates at the Paducah Gaseous Diffusion Plant are.

  5. Usual Dietary Intakes: SAS Macros for Fitting Multivariate Measurement Error Models & Estimating Multivariate Usual Intake Distributions

    Science.gov (United States)

    The following SAS macros can be used to create a multivariate usual intake distribution for multiple dietary components that are consumed nearly every day or episodically. A SAS macro for performing balanced repeated replication (BRR) variance estimation is also included.

  6. SAS-macros for estimation and prediction in an model of the electricity consumption

    DEFF Research Database (Denmark)

    1998-01-01

    SAS-macros for estimation and prediction in an model of the electricity consumption'' is a large collection of SAS-macros for handling a model of the electricity consumption in the Eastern Denmark. The macros are installed at Elkraft, Ballerup.......SAS-macros for estimation and prediction in an model of the electricity consumption'' is a large collection of SAS-macros for handling a model of the electricity consumption in the Eastern Denmark. The macros are installed at Elkraft, Ballerup....

  7. A Tool that Uses the SAS (registered trademark) PRX Functions to Fix Delimited Text Files

    Science.gov (United States)

    2015-07-07

    Article 3. DATES COVERED (From – To) Dec 2014 – Apr 2015 4. TITLE AND SUBTITLE A Tool that Uses the SAS® PRX Functions to Fix Delimited Text Files 5a...Guide® project that uses the SAS PRX functions to import, fix, and export a delimited text file. This fixed file can then be easily imported and...sas, perl, prx , prx functions, sas enterprise guide, sas eg, prxmatch, prxchange 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR

  8. The SAS Education Value-Added Assessment System (SAS[R] EVAAS[R]) in the Houston Independent School District (HISD): Intended and Unintended Consequences

    Science.gov (United States)

    Amrein-Beardsley, Audrey; Collins, Clarin

    2012-01-01

    The SAS Educational Value-Added Assessment System (SAS[R] EVAAS[R]) is the most widely used value-added system in the country. It is also self-proclaimed as "the most robust and reliable" system available, with its greatest benefit to help educators improve their teaching practices. This study critically examined the effects of SAS[R] EVAAS[R] as…

  9. 面向对象的SAS/AF程序设计语言的研究%Research on Object-Oriented Programming with SAS/AF Language

    Institute of Scientific and Technical Information of China (English)

    陈宇术

    2001-01-01

    This paper aims at introducing object-oriented program language using SAS/AF with the concepts of OOA and OOD.And it also discusses how to achieve these concepts in SAS/AF language.%本文结合面向对象分析(OOA)与面向对象设计(OOD)介绍了面向对象的SAS/AF程序语言及探讨了面向对象的理念在SAS/AF中的实现。

  10. Olev Schults : SAS vajab Estonian Airi rahvusliku lennufirmana / Olev Schults ; interv. Andres Reimer

    Index Scriptorium Estoniae

    Schults, Olev

    2008-01-01

    Estonian Airi nõukogu esimees vastab küsimustele, kas SAS arendas Läti airBalticut Estonian SAS-i arvel, mis mõte on rahvuslikul lennukompaniil, kui riik ei tohi seda finantseerida, kuidas mõjutab investorite meeleolu SAS-i Eestis tabanud poliitikute kriitika tulv

  11. %HPGLIMMIX: A High-Performance SAS Macro for GLMM Estimation

    Directory of Open Access Journals (Sweden)

    Liang Xie

    2014-06-01

    Full Text Available Generalized linear mixed models (GLMMs comprise a class of widely used statistical tools for data analysis with fixed and random effects when the response variable has a conditional distribution in the exponential family. GLMM analysis also has a close relationship with actuarial credibility theory. While readily available programs such as the GLIMMIX procedure in SAS and the lme4 package in R are powerful tools for using this class of models, these progarms are not able to handle models with thousands of levels of fixed and random effects. By using sparse-matrix and other high performance techniques, procedures such as HPMIXED in SAS can easily fit models with thousands of factor levels, but only for normally distributed response variables. In this paper, we present the %HPGLIMMIX SAS macro that fits GLMMs with large number of sparsely populated design matrices using the doubly-iterative linearization (pseudo-likelihood method, in which the sparse-matrix-based HPMIXED is used for the inner iterations with the pseudo-variable constructed from the inverse-link function and the chosen model. Although the macro does not have the full functionality of the GLIMMIX procedure, time and memory savings can be large with the new macro. In applications in which design matrices contain many zeros and there are hundreds or thousands of factor levels, models can be fitted without exhausting computer memory, and 90% or better reduction in running time can be observed. Examples with a Poisson, binomial, and gamma conditional distribution are presented to demonstrate the usage and efficiency of this macro.

  12. Categorical Data Analysis With Sas and Spss Applications

    CERN Document Server

    Lawal, H Bayo

    2003-01-01

    This book covers the fundamental aspects of categorical data analysis with an emphasis on how to implement the models used in the book using SAS and SPSS. This is accomplished through the frequent use of examples, with relevant codes and instructions, that are closely related to the problems in the text. Concepts are explained in detail so that students can reproduce similar results on their own. Beginning with chapter two, exercises at the end of each chapter further strengthen students' understanding of the concepts by requiring them to apply some of the ideas expressed in the text in a more

  13. Identify S.A.S. -Plan de empresa

    OpenAIRE

    2012-01-01

    IDENTIFY S.A.S. – Soluciones en Tecnología, tiene como objetivos desarrollar un plan de empresa para suplir una de las necesidades, que en la actualidad cobra importancia en los centros hospitalarios y que contribuye al control y detección automática de personas y activos y control de temperatura enn activos dedicados al almacenamiento de medicamentos e insumos, permitiendo el manejo de la información en tiempo real; teniendo presente la normatividad que las rige, la seguridad que les propor...

  14. Plan de empresa SZ Gastroconsulting S.A.S.

    OpenAIRE

    Zuloaga Galofre, David; Serrano Zuleta, Juanita

    2015-01-01

    SZ GastroConsulting S.A.S. es una empresa colombiana que prestará servicios de consultoría al sector de restaurantes. El core del negocio estará orientado a incrementar la rotación de clientes y la facturación de los restaurantes. De forma complementaria, se adoptarán prácticas tecnológicas, aprovechando el entorno actual donde los comensales inician su experiencia de consumo antes de ir al restaurante, y la finalizan días después de vivirla. La compañía será dirigida por los socios y consult...

  15. Plan de Negocios Qualitas S.A.S.

    OpenAIRE

    Verutti Bonilla, María Cecilia; Ávila González, Gloria Inés; Ortiz Alvarado, Francisco Javier

    2012-01-01

    Qualitas S.A.S. Health & Consulting (del latín: “calidad”), nace un equipo multidisciplinario de profesionales de crear una empresa de consultoría especializada en salud en Popayán, como apoyo a los Prestadores de Servicios de Salud, en aspectos relacionados con los requisitos que deben cumplir ante las normas del Sistema Obligatorio de Garantía de la Calidad en Salud que reglamentan la atención de calidad en los servicios de salud en Colombia, teniendo como meta la excelencia. Objetivos: R...

  16. Seismic Creep

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden erupture associated with an earthquake. It is a usually slow deformation...

  17. Seismic seiches

    Science.gov (United States)

    McGarr, Arthur; Gupta, Harsh K.

    2011-01-01

    Seismic seiche is a term first used by Kvale (1955) to discuss oscillations of lake levels in Norway and England caused by the Assam earthquake of August 15, 1950. This definition has since been generalized to apply to standing waves set up in closed, or partially closed, bodies of water including rivers, shipping channels, lakes, swimming pools and tanks due to the passage of seismic waves from an earthquake.

  18. Seismologic study of Los Humeros geothermal field, Puebla, Mexico. Part II: Seismic tomography by attenuation of coda waves (Qc-1) of local earthquakes; Estudio sismologico del campo geotermico de Los Humeros, Puebla, Mexico. Parte II: Tomografia sismica por atenuacion a partir de ondas de coda (Qc-1) de sismos locales

    Energy Technology Data Exchange (ETDEWEB)

    Antayhua, Yanet; Lermo, Javier [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, D.F (Mexico); Carlos, Vargas [Departamento de Geociencias, Universidad Nacional de Colombia (Colombia)]. E-mail: jles@pumas.iingen.unam.mx

    2008-07-15

    In the Los Humeros geothermal field, Puebla, seismic tomography has been studied using the attenuation of coda waves (Qc{sup -1}). Ninety-five local earthquakes (Md{<=}3.6) have been used with depths up to 4.0 km registered in the seismic network stations from December 1997 to December 2004. A simple backscattering model was used, filtered in four ranks of frequencies (2, 4, 6, and 8 Hz) and one window of 5 seconds. For the 3D-representation, we used an approximation based on first-order scattering of ellipsoids. The results show that values of Qc for the used frequencies have a frequency dependency shown in the equation: Qc=24{+-}12f{sup 0.86}{+-}{sup 0.06}, where the low values of Qc were observed in the zone of higher seismic and tectonic activity and in the location of injection and production wells. The high values are located in the periphery of the geothermal field. The distribution of the Qc{sup -1} attenuation in 3D and 2D shows the anomalies of high-seismic attenuation are located in the north, south, and southwestern ends of the zone presently under operation, at depths greater than 2.5 km. [Spanish] Para realizar la tomografia sismica por atenuacion de ondas de coda (Qc{sup -1}) en el campo geotermico de Los Humeros, Puebla, se han utilizado 95 sismos locales (Md{<=}3.6) con profundidades hasta 4.0 km, registrados en las estaciones de su red sismica, durante el periodo de diciembre 1997 a diciembre 2004. Se utilizo el modelo de retrodispersion simple, filtrados en cuatro rangos de frecuencias (2, 4, 6, y 8 Hz) y una ventana de 5 segundos. Para la representacion en 3D, se utilizo una aproximacion basada en elipsoides que representan dispersion de primer orden. Los resultados muestran que los valores de Qc para las frecuencias utilizadas tienen una dependencia con la frecuencia de la forma: Qc=24{+-}12f{sup 0.86}{+-}{sup 0.06}, donde los valores bajos de Qc fueron observados en la zona de mayor actividad sismica y en la ubicacion de pozos inyectores y

  19. Polymer encapsulation of amoxicillin microparticles by SAS process.

    Science.gov (United States)

    Montes, A; Baldauf, E; Gordillo, M D; Pereyra, C M; Martínez de la Ossa, E J

    2014-01-01

    Encapsulation of amoxicillin (AMC) with ethyl cellulose (EC) by a supercritical antisolvent process (SAS) was investigated. AMC microparticles obtained previously by an SAS process were used as host particles and EC, a biodegradable polymer used for the controlled release of drugs, was chosen as the coating material. In this work, a suspension of AMC microparticles in a solution of ethyl cellulose in dichloromethane (DCM) was sprayed through a nozzle into supercritical CO2. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and HPLC analyses were carried out. The effects of AMC:EC ratio, the initial polymer concentration of the solution, temperature and pressure on the encapsulation process were investigated. Although all the experiments led to powder precipitation, the AMC encapsulation was achieved in only half of the cases, particularly when the lower drug:polymer ratios were assayed. In general, it was observed that the percentages of AMC present in the precipitates were higher on increasing the AMC:EC ratio. In these cases composites rather than encapsulates were obtained. The in vitro release profiles of the resulting materials were evaluated in order to ascertain whether composites can be used as encapsulated systems for drug delivery systems.

  20. Recent high energy gamma-ray results from SAS-2

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Ogelman, H. B.; Ozel, M. E.; Tumer, T.; Lamb, R. C.

    1977-01-01

    Recent developments in gamma-ray astronomy due to the results from SAS-2 have focused on two areas. First, the emission from the plane of the Galaxy is the dominant feature in the gamma-ray sky. The galactic latitude and longitude distributions are consistent with the concept that the high-energy radiation originates from cosmic rays interacting with interstellar matter, and the measurements support a galactic origin for cosmic rays. Second, searches of the SAS-2 data for emission from localized sources have shown three strong discrete gamma-ray sources: the Crab nebula and PSR 0531 + 21, the Vela supernova remnant and PSR 0833-45, and a source near galactic coordinates 193 deg longitude, +3 deg latitude, which does not appear to be associated with other known celestial objects. Evidence has also been found for pulsed gamma-ray emission from two other radio pulsars, PSR 1818-04 and PSR 1747-46. A localized source near longitudes 76-80 deg may be associated with the X-ray source Cyg X-3.

  1. The Caenorhabditis elegans protein SAS-5 forms large oligomeric assemblies critical for centriole formation.

    Science.gov (United States)

    Rogala, Kacper B; Dynes, Nicola J; Hatzopoulos, Georgios N; Yan, Jun; Pong, Sheng Kai; Robinson, Carol V; Deane, Charlotte M; Gönczy, Pierre; Vakonakis, Ioannis

    2015-05-29

    Centrioles are microtubule-based organelles crucial for cell division, sensing and motility. In Caenorhabditis elegans, the onset of centriole formation requires notably the proteins SAS-5 and SAS-6, which have functional equivalents across eukaryotic evolution. Whereas the molecular architecture of SAS-6 and its role in initiating centriole formation are well understood, the mechanisms by which SAS-5 and its relatives function is unclear. Here, we combine biophysical and structural analysis to uncover the architecture of SAS-5 and examine its functional implications in vivo. Our work reveals that two distinct self-associating domains are necessary to form higher-order oligomers of SAS-5: a trimeric coiled coil and a novel globular dimeric Implico domain. Disruption of either domain leads to centriole duplication failure in worm embryos, indicating that large SAS-5 assemblies are necessary for function in vivo.

  2. Imaging Rayleigh wave attenuation with USArray

    Science.gov (United States)

    Bao, Xueyang; Dalton, Colleen A.; Jin, Ge; Gaherty, James B.; Shen, Yang

    2016-07-01

    The EarthScope USArray provides an opportunity to obtain detailed images of the continental upper mantle at an unprecedented scale. The majority of mantle models derived from USArray data to date contain spatial variations in seismic-wave speed; however, in many cases these data sets do not by themselves allow a non-unique interpretation. Joint interpretation of seismic attenuation and velocity models can improve upon the interpretations based only on velocity and provide important constraints on the temperature, composition, melt content, and volatile content of the mantle. The surface wave amplitudes that constrain upper-mantle attenuation are sensitive to factors in addition to attenuation, including the earthquake source excitation, focusing and defocusing by elastic structure, and local site amplification. Because of the difficulty of isolating attenuation from these other factors, little is known about the attenuation structure of the North American upper mantle. In this study, Rayleigh wave traveltime and amplitude in the period range 25-100 s are measured using an interstation cross-correlation technique, which takes advantage of waveform similarity at nearby stations. Several estimates of Rayleigh wave attenuation and site amplification are generated at each period, using different approaches to separate the effects of attenuation and local site amplification on amplitude. It is assumed that focusing and defocusing effects can be described by the Laplacian of the traveltime field. All approaches identify the same large-scale patterns in attenuation, including areas where the attenuation values are likely contaminated by unmodelled focusing and defocusing effects. Regionally averaged attenuation maps are constructed after removal of the contaminated attenuation values, and the variations in intrinsic shear attenuation that are suggested by these Rayleigh wave attenuation maps are explored.

  3. Updated Colombian Seismic Hazard Map

    Science.gov (United States)

    Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

    2013-05-01

    The Colombian seismic hazard map used by the National Building Code (NSR-98) in effect until 2009 was developed in 1996. Since then, the National Seismological Network of Colombia has improved in both coverage and technology providing fifteen years of additional seismic records. These improvements have allowed a better understanding of the regional geology and tectonics which in addition to the seismic activity in Colombia with destructive effects has motivated the interest and the need to develop a new seismic hazard assessment in this country. Taking advantage of new instrumental information sources such as new broad band stations of the National Seismological Network, new historical seismicity data, standardized global databases availability, and in general, of advances in models and techniques, a new Colombian seismic hazard map was developed. A PSHA model was applied. The use of the PSHA model is because it incorporates the effects of all seismic sources that may affect a particular site solving the uncertainties caused by the parameters and assumptions defined in this kind of studies. First, the seismic sources geometry and a complete and homogeneous seismic catalog were defined; the parameters of seismic rate of each one of the seismic sources occurrence were calculated establishing a national seismotectonic model. Several of attenuation-distance relationships were selected depending on the type of seismicity considered. The seismic hazard was estimated using the CRISIS2007 software created by the Engineering Institute of the Universidad Nacional Autónoma de México -UNAM (National Autonomous University of Mexico). A uniformly spaced grid each 0.1° was used to calculate the peak ground acceleration (PGA) and response spectral values at 0.1, 0.2, 0.3, 0.5, 0.75, 1, 1.5, 2, 2.5 and 3.0 seconds with return periods of 75, 225, 475, 975 and 2475 years. For each site, a uniform hazard spectrum and exceedance rate curves were calculated. With the results, it is

  4. SPSS and SAS programs for generalizability theory analyses.

    Science.gov (United States)

    Mushquash, Christopher; O'Connor, Brian P

    2006-08-01

    The identification and reduction of measurement errors is a major challenge in psychological testing. Most investigators rely solely on classical test theory for assessing reliability, whereas most experts have long recommended using generalizability theory instead. One reason for the common neglect of generalizability theory is the absence of analytic facilities for this purpose in popular statistical software packages. This article provides a brief introduction to generalizability theory, describes easy to use SPSS, SAS, and MATLAB programs for conducting the recommended analyses, and provides an illustrative example, using data (N = 329) for the Rosenberg Self-Esteem Scale. Program output includes variance components, relative and absolute errors and generalizability coefficients, coefficients for D studies, and graphs of D study results.

  5. Modeling binary correlated responses using SAS, SPSS and R

    CERN Document Server

    Wilson, Jeffrey R

    2015-01-01

    Statistical tools to analyze correlated binary data are spread out in the existing literature. This book makes these tools accessible to practitioners in a single volume. Chapters cover recently developed statistical tools and statistical packages that are tailored to analyzing correlated binary data. The authors showcase both traditional and new methods for application to health-related research. Data and computer programs will be publicly available in order for readers to replicate model development, but learning a new statistical language is not necessary with this book. The inclusion of code for R, SAS, and SPSS allows for easy implementation by readers. For readers interested in learning more about the languages, though, there are short tutorials in the appendix. Accompanying data sets are available for download through the book s website. Data analysis presented in each chapter will provide step-by-step instructions so these new methods can be readily applied to projects.  Researchers and graduate stu...

  6. Non-linear Growth Models in Mplus and SAS.

    Science.gov (United States)

    Grimm, Kevin J; Ram, Nilam

    2009-10-01

    Non-linear growth curves or growth curves that follow a specified non-linear function in time enable researchers to model complex developmental patterns with parameters that are easily interpretable. In this paper we describe how a variety of sigmoid curves can be fit using the Mplus structural modeling program and the non-linear mixed-effects modeling procedure NLMIXED in SAS. Using longitudinal achievement data collected as part of a study examining the effects of preschool instruction on academic gain we illustrate the procedures for fitting growth models of logistic, Gompertz, and Richards functions. Brief notes regarding the practical benefits, limitations, and choices faced in the fitting and estimation of such models are included.

  7. %ERA: A SAS Macro for Extended Redundancy Analysis

    Directory of Open Access Journals (Sweden)

    Pietro Giorgio Lovaglio

    2016-10-01

    Full Text Available A new approach to structural equation modeling based on so-called extended redundancy analysis has been recently proposed in the literature, enhanced with the added characteristic of generalizing redundancy analysis and reduced-rank regression models for more than two blocks. In this approach, the relationships between the observed exogenous variables and the observed endogenous variables are moderated by the presence of unobservable composites that were estimated as linear combinations of exogenous variables, permitting a great flexibility to specify and fit a variety of structural relationships. In this paper, we propose the SAS macro %ERA to specify and fit structural relationships in the extended redundancy analysis (ERA framework. Two examples (simulation and real data are provided in order to reproduce results appearing in the original article where ERA was proposed.

  8. SAS-2 galactic gamma ray results. 2. Localized sources

    Science.gov (United States)

    Hartman, R. C.; Fichtel, C. E.; Kniffen, D. A.; Lamb, R. C.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1976-01-01

    Gamma-ray emission was detected from the radio pulsars PSR1818-04 and PSR1747-46, in addition to the previously reported gamma-ray emission from the Crab and Vela pulsars. Since the Crab pulsar is the only one observed in the optical and X-ray bands, these gamma-ray observations suggest a uniquely gamma-ray phenomenon occurring in a fraction of the radio pulsars. Using distance estimates it is found that PSR1818-04 has a gamma-ray luminosity comparable to that of the Crab pulsar, while the luminosities of PSR1747-46 and the Vela pulsar are approximately an order of magnitude lower. This survey of SAS-2 data for pulsar correlations has also yielded upper limits to gamma-ray luminosity for 71 other radio pulsars.

  9. Centriolar CPAP/SAS-4 Imparts Slow Processive Microtubule Growth.

    Science.gov (United States)

    Sharma, Ashwani; Aher, Amol; Dynes, Nicola J; Frey, Daniel; Katrukha, Eugene A; Jaussi, Rolf; Grigoriev, Ilya; Croisier, Marie; Kammerer, Richard A; Akhmanova, Anna; Gönczy, Pierre; Steinmetz, Michel O

    2016-05-23

    Centrioles are fundamental and evolutionarily conserved microtubule-based organelles whose assembly is characterized by microtubule growth rates that are orders of magnitude slower than those of cytoplasmic microtubules. Several centriolar proteins can interact with tubulin or microtubules, but how they ensure the exceptionally slow growth of centriolar microtubules has remained mysterious. Here, we bring together crystallographic, biophysical, and reconstitution assays to demonstrate that the human centriolar protein CPAP (SAS-4 in worms and flies) binds and "caps" microtubule plus ends by associating with a site of β-tubulin engaged in longitudinal tubulin-tubulin interactions. Strikingly, we uncover that CPAP activity dampens microtubule growth and stabilizes microtubules by inhibiting catastrophes and promoting rescues. We further establish that the capping function of CPAP is important to limit growth of centriolar microtubules in cells. Our results suggest that CPAP acts as a molecular lid that ensures slow assembly of centriolar microtubules and, thereby, contributes to organelle length control.

  10. SAS program for quantitative stratigraphic correlation by principal components

    Science.gov (United States)

    Hohn, M.E.

    1985-01-01

    A SAS program is presented which constructs a composite section of stratigraphic events through principal components analysis. The variables in the analysis are stratigraphic sections and the observational units are range limits of taxa. The program standardizes data in each section, extracts eigenvectors, estimates missing range limits, and computes the composite section from scores of events on the first principal component. Provided is an option of several types of diagnostic plots; these help one to determine conservative range limits or unrealistic estimates of missing values. Inspection of the graphs and eigenvalues allow one to evaluate goodness of fit between the composite and measured data. The program is extended easily to the creation of a rank-order composite. ?? 1985.

  11. Seismic Studies

    Energy Technology Data Exchange (ETDEWEB)

    R. Quittmeyer

    2006-09-25

    This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

  12. Phosphorylation of SAS-6 by ZYG-1 is critical for centriole formation in C. elegans embryos.

    Science.gov (United States)

    Kitagawa, Daiju; Busso, Coralie; Flückiger, Isabelle; Gönczy, Pierre

    2009-12-01

    Despite being essential for proper cell division, the mechanisms governing centrosome duplication are incompletely understood and represent an important open question in cell biology. Formation of a new centriole next to each existing one is critical for centrosome duplication. In Caenorhabditis elegans embryos, the proteins SPD-2, ZYG-1, SAS-6, SAS-5, and SAS-4 are essential for centriole formation, but the mechanisms underlying their requirement remain unclear. Here, we demonstrate that the kinase ZYG-1 phosphorylates the coiled-coil protein SAS-6 at serine 123 in vitro. Importantly, we show that this phosphorylation event is crucial for centriole formation in vivo. Furthermore, we establish that such phosphorylation ensures the maintenance of SAS-6 at the emerging centriole. Overall, our findings establish that phosphorylation of the evolutionarily conserved protein SAS-6 is critical for centriole formation and thus for faithful cell division.

  13. LSI推出首批半高SAS RAID适配器

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    LSI Logic公司近日宣布推出首批半高(low—profile,LP)SAS RAID存储适配器。新的MegaRAID SAS 8308ELP和SAS8344ELP是具有8个SAS端口的PCI Express接口适配器,应用于需要使用3GbpsSAS和/或SATAⅡ驱动器的服务器和工作站环境。

  14. Seismic Symphonies

    Science.gov (United States)

    Strinna, Elisa; Ferrari, Graziano

    2015-04-01

    The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of seismic records. In this case seismic frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation system that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the seismic records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's Seismic Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of seismic history of the Earth. A bridge between art and science. Seismic Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and

  15. Validity of Simpson-Angus Scale (SAS in a naturalistic schizophrenia population

    Directory of Open Access Journals (Sweden)

    Tuisku Katinka

    2005-03-01

    Full Text Available Abstract Background Simpson-Angus Scale (SAS is an established instrument for neuroleptic-induced parkinsonism (NIP, but its statistical properties have been studied insufficiently. Some shortcomings concerning its content have been suggested as well. According to a recent report, the widely used SAS mean score cut-off value 0.3 of for NIP detection may be too low. Our aim was to evaluate SAS against DSM-IV diagnostic criteria for NIP and objective motor assessment (actometry. Methods Ninety-nine chronic institutionalised schizophrenia patients were evaluated during the same interview by standardised actometric recording and SAS. The diagnosis of NIP was based on DSM-IV criteria. Internal consistency measured by Cronbach's α, convergence to actometry and the capacity for NIP case detection were assessed. Results Cronbach's α for the scale was 0.79. SAS discriminated between DSM-IV NIP and non-NIP patients. The actometric findings did not correlate with SAS. ROC-analysis yielded a good case detection power for SAS mean score. The optimal threshold value of SAS mean score was between 0.65 and 0.95, i.e. clearly higher than previously suggested threshold value. Conclusion We conclude that SAS seems a reliable and valid instrument. The previously commonly used cut-off mean score of 0.3 has been too low resulting in low specificity, and we suggest a new cut-off value of 0.65, whereby specificity could be doubled without loosing sensitivity.

  16. 关于SAS-Weblogic的数据挖掘模型的应用分析

    Institute of Scientific and Technical Information of China (English)

    周清松

    2015-01-01

    本文在对SAS-Weblogic的数据挖掘模型和应用进行应用分析时,首先分析了SAS-Weblogic的数据挖掘模型,最后基于实例分析了SAS-Weblogic的数据挖掘模型的具体应用。SAS-Weblogic数据挖掘模型不仅仅解决了一般数据量的设计要求,结合ARIMA模型同样对于大数据量的设计要求也能得到有效的解决。

  17. Observations of low energy gamma-ray bursts with SAS-2

    Science.gov (United States)

    Oegelman, H.; Fichtel, C. E.; Kniffen, D. A.

    1975-01-01

    The present paper reports on the low-energy gamma-ray bursts observed by the plastic scintillator anticoincidence dome of the Small Astronomy Satellite-2 (SAS-2) gamma-ray telescope. SAS-2 detected two events observed by other satellites and discovered one which was subsequently confirmed by other satellite observations. Two events seen by other satellites were not detected by SAS-2, probably due to earth occultation. The event detection threshold for SAS-2 was almost two orders of magnitude lower than that of the Vela satellites.

  18. A SAS/IML program using the Kalman filter for estimating state space models.

    Science.gov (United States)

    Gu, Fei; Yung, Yiu-Fai

    2013-03-01

    To help disseminate the knowledge and software implementation of a state space model (SSM), this article provides a SAS/IML (SAS Institute, 2010) program for estimating the parameters of general linear Gaussian SSMs using the Kalman filter algorithm. In order to use this program, the user should have SAS installed on a computer and have a valid license for SAS/IML. Since the code is completely open, it is expected that this program can be used not only by applied researchers, but also by quantitative methodologists who are interested in improving their methods and promoting SSM as a research instrument.

  19. PP2A phosphatase acts upon SAS-5 to ensure centriole formation in C. elegans embryos.

    Science.gov (United States)

    Kitagawa, Daiju; Flückiger, Isabelle; Polanowska, Jolanta; Keller, Debora; Reboul, Jérôme; Gönczy, Pierre

    2011-04-19

    Centrosome duplication occurs once per cell cycle and ensures that the two resulting centrosomes assemble a bipolar mitotic spindle. Centriole formation is fundamental for centrosome duplication. In Caenorhabditis elegans, the evolutionarily conserved proteins SPD-2, ZYG-1, SAS-6, SAS-5, and SAS-4 are essential for centriole formation, but how they function is not fully understood. Here, we demonstrate that Protein Phosphatase 2A (PP2A) is also critical for centriole formation in C. elegans embryos. We find that PP2A subunits genetically and physically interact with the SAS-5/SAS-6 complex. Furthermore, we show that PP2A-mediated dephosphorylation promotes centriolar targeting of SAS-5 and ensures SAS-6 delivery to the site of centriole assembly. We find that PP2A is similarly needed for the presence of HsSAS-6 at centrioles and for centriole formation in human cells. These findings lead us to propose that PP2A-mediated loading of SAS-6 proteins is critical at the onset of centriole formation.

  20. The Seismic Alert System of Mexico and their automatic Alert Signals broadcast improvements

    Science.gov (United States)

    Espinosa Aranda, J.; Cuellar Martinez, A.; Garcia, A.; Ibarrola, G.; Islas, R.; Maldonado, S.

    2009-12-01

    The Mexican Seismic Alert System (SASMEX), is integrated by the Seismic Alert System of Mexico City (SAS), in continuous operation since 1991, and the Seismic Alert System of Oaxaca City (SASO) that started its service in 2003. The SAS generates automatic broadcast of Public and Preventive Alert Signals to the cities of Mexico, Toluca, Acapulco and Chilpancingo, and SASO by now only to Oaxaca City. Two types of SASMEX Seismic Alert Signal ranges were determinated in accordance with each local Civil Protection Authorities: Public Alert if they expect strong earthquake effects and Preventive Alert Signal, for moderated once. SAS has 12 field sensor stations covering partial segment of the Guerrero coast, and the SASO has 35 field sensor stations operating in the coast, central and north of the Oaxaca, covering the seismic danger territory. Since 1993, the SAS is pioneer in the automatic public alert broadcast services, thanks to the support of the Asociación de Radiodifusores del Valle de México, A.C. (ARVM). Historically in Mexico City, due to their great distance to the coast of Guerrero, the SAS has been issued its Alert Signals with an opportunity average of 60 seconds. In Oaxaca City the SASO gives 30 seconds time opportunity, if the earthquake detected is occurring in the Oaxaca coast region, or less time, if the seismic event hits near of this town. Also the SASO has been supported since its implementation for local commercial radio stations. Today the SAS and SASO have been generated respectively 13 and 3 Public Alert signals, also 63 and 5 Preventive Alerts ones. Nevertheless, the final effectiveness of the SASMEX Alert Signal services is sensible to the particular conditions of the user in risk, they must have their radio receiver or TV set turned on, also they must know what to do if the seismic warning is issued, other way they do not have opportunity to react reducing their vulnerability, mainly at night. These reason justify the support of the

  1. SAS molecular tests Salmonella detection kit. Performance tested method 021202.

    Science.gov (United States)

    Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L

    2014-01-01

    The SAS Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli 0157. Thus, after a short 6-7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.

  2. Circinus X-1 - X-ray observations with SAS 3

    Science.gov (United States)

    Dower, R. G.; Bradt, H. V.; Morgan, E. H.

    1982-01-01

    Eight observations of Cir X-1 with SAS 3, each lasting 1-6 days, have yielded a variety of new phenomena, viz., a luminous state of steady emission, rapid large-intensity dips, an extremely rapid X-ray transition, and bright flares. Through searches for periodic X-ray pulsations were carried out on data trains of duration up to 6 days; upper limits for pulsations with periods greater than 250 microsec range down to 0.3%. Aperiodic variability with characteristic times of 0.4-1.0 sec was observed but is not well characterized by a simple shot noise model. No millisecond bursts were observed during 40,000 sec in three separate observations. Spectral parameters derived before and after several X-ray transitions indicate that the transitions are not due to absorption of X-rays by intervening gas. Models previously proposed for the Cir X-1 system do not easily provide explanations for all the complex phenomena reported herein.

  3. SAS-2 galactic gamma-ray results. 2: Localized sources

    Science.gov (United States)

    Hartman, R. C.; Fichtel, C. E.; Kniffen, D. A.; Lamb, R. C.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. E.; Tuemer, T.

    1977-01-01

    Gamma ray emission was detected from the radio pulsars PSR 1818-04 and PSR 1747-46, in addition to the previously reported gamma ray emission from the Crab and Vela pulsars. Because the Crab pulsar is the only one observed in the optical and X-ray bands, these gamma ray observations suggest a uniquely gamma ray phenomenon occurring in a fraction of the radio pulsars. PSR 1818-04 has a gamma ray luminosity comparable to that of the Crab pulsar, whereas the luminosities of PSR 1747-46 and the Vela pulsar are approximately an order of magnitude lower. SAS-2 data for pulsar correlations yielded upper limits to gamma ray luminosity for 71 other radio pulsars. For five of the closest pulsars, upper limits for gamma ray luminosity are found to be at least three orders of magnitude lower than that of the Crab pulsar. Gamma ray enhancement near the Milky Way satellite galaxy and the galactic plane in the Cygnus region is also discussed.

  4. Random noise attenuation using an improved anisotropic total variation regularization

    Science.gov (United States)

    Gemechu, Diriba; Yuan, Huan; Ma, Jianwei

    2017-09-01

    In seismic data processing, attenuation of random noise from the observed data is the basic step which improves the signal-to-noise ratio (SNR) of seismic data. In this paper, we proposed an anisotropic total bounded variation regularization approach to attenuate noise. An improved constraint convex optimization model is formulated for this approach and then the split Bregman algorithm is used to solve the optimization model. Generalized cross validation (GCV) technique is used to estimate the regularization parameter. Synthetic and real seismic data are considered to show the out performance of the proposed method in terms of event-preserving denoising, in comparison with FX deconvolution, shearlet hard thresholding, and anisotropic total variation methods. The numerical results indicate that the proposed method effectively attenuates random noise by preserving the structure and important features of seismic data.

  5. Large scale mechanical metamaterials as seismic shields

    Science.gov (United States)

    Miniaci, Marco; Krushynska, Anastasiia; Bosia, Federico; Pugno, Nicola M.

    2016-08-01

    Earthquakes represent one of the most catastrophic natural events affecting mankind. At present, a universally accepted risk mitigation strategy for seismic events remains to be proposed. Most approaches are based on vibration isolation of structures rather than on the remote shielding of incoming waves. In this work, we propose a novel approach to the problem and discuss the feasibility of a passive isolation strategy for seismic waves based on large-scale mechanical metamaterials, including for the first time numerical analysis of both surface and guided waves, soil dissipation effects, and adopting a full 3D simulations. The study focuses on realistic structures that can be effective in frequency ranges of interest for seismic waves, and optimal design criteria are provided, exploring different metamaterial configurations, combining phononic crystals and locally resonant structures and different ranges of mechanical properties. Dispersion analysis and full-scale 3D transient wave transmission simulations are carried out on finite size systems to assess the seismic wave amplitude attenuation in realistic conditions. Results reveal that both surface and bulk seismic waves can be considerably attenuated, making this strategy viable for the protection of civil structures against seismic risk. The proposed remote shielding approach could open up new perspectives in the field of seismology and in related areas of low-frequency vibration damping or blast protection.

  6. A study on seismicity and seismic hazard for Karnataka State

    Indian Academy of Sciences (India)

    T G Sitharam; Naveen James; K S Vipin; K Ganesha Raj

    2012-04-01

    This paper presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the present work, historical and instrumental seismicity data for Karnataka (within 300 km from Karnataka political boundary) were compiled and hazard analysis was done based on this data. Geographically, Karnataka forms a part of peninsular India which is tectonically identified as an intraplate region of Indian plate. Due to the convergent movement of the Indian plate with the Eurasian plate, movements are occurring along major intraplate faults resulting in seismic activity of the region and hence the hazard assessment of this region is very important. Apart from referring to seismotectonic atlas for identifying faults and fractures, major lineaments in the study area were also mapped using satellite data. The earthquake events reported by various national and international agencies were collected until 2009. Declustering of earthquake events was done to remove foreshocks and aftershocks. Seismic hazard analysis was done for the state of Karnataka using both deterministic and probabilistic approaches incorporating logic tree methodology. The peak ground acceleration (PGA) at rock level was evaluated for the entire state considering a grid size of 0.05° × 0.05°. The attenuation relations proposed for stable continental shield region were used in evaluating the seismic hazard with appropriate weightage factors. Response spectra at rock level for important Tier II cities and Bangalore were evaluated. The contour maps showing the spatial variation of PGA values at bedrock are presented in this work.

  7. Using SAS/IntrNet for Evaluating Web-Based Courses.

    Science.gov (United States)

    Yu, Chong-ho; Jannasch-Pennell, Angel; Digangi, Sam; Wasson, Barnaby

    1998-01-01

    Describes the use of SAS/IntrNet, a Web service rather than a Web server, to evaluate and enhance university level Web-based courses. IntrNet provides the ability to create both static and dynamic Web pages, using Web publishing tools to convert SAS output to hypertext markup language for the creation of static Web pages. (Author/LRW)

  8. Using SAS/IntrNet for Evaluating Web-Based Courses.

    Science.gov (United States)

    Yu, Chong-ho; Jannasch-Pennell, Angel; Digangi, Sam; Wasson, Barnaby

    1998-01-01

    Describes the use of SAS/IntrNet, a Web service rather than a Web server, to evaluate and enhance university level Web-based courses. IntrNet provides the ability to create both static and dynamic Web pages, using Web publishing tools to convert SAS output to hypertext markup language for the creation of static Web pages. (Author/LRW)

  9. SAS üritab panna riiki lennufirma aktsiaid müüma / Lemmi Kann

    Index Scriptorium Estoniae

    Kann, Lemmi

    2007-01-01

    SAS-i eesmärgiks on saada enamusosalus nii Estonian Airis kui ka airBalticus, et seeläbi oma positsioone Baltimaades kinnistada. Diagramm: Estonian Airi majandusnäitajad ja omanikud. Vt. samas: SAS on Estonian Airi jahtinud kaua. Kommenteerib Raivo Vare

  10. SAS tahab Estonian Airi liita lätlaste firmaga airBaltic / Andres Eilart

    Index Scriptorium Estoniae

    Eilart, Andres

    2007-01-01

    SAS plaanib Estonian Airi ja Läti firma airBalticu liitmisega luua uue lennufirma. Autori hinnangul viitavad Estonian Airi laienemisplaanidele kriipsu peale tõmbamine ja SAS-i investeeringud airBalticusse sellele, et ühendamise käigus "neelab" Läti firma Estonian Airi

  11. Social Anxiety Scale for Adolescents (SAS-A): Measuring Social Anxiety among Finnish Adolescents

    Science.gov (United States)

    Ranta, Klaus; Junttila, Niina; Laakkonen, Eero; Uhmavaara, Anni; La Greca, Annette M.; Niemi, Paivi M.

    2012-01-01

    The aim of this study was to investigate symptoms of social anxiety and the psychometric properties of the "Social Anxiety Scale for Adolescents" (SAS-A) among Finnish adolescents, 13-16 years of age. Study 1 (n = 867) examined the distribution of SAS-A scores according to gender and age, and the internal consistency and factor structure…

  12. [Standardization of the Greek version of Zung's Self-rating Anxiety Scale (SAS)].

    Science.gov (United States)

    Samakouri, M; Bouhos, G; Kadoglou, M; Giantzelidou, A; Tsolaki, K; Livaditis, M

    2012-01-01

    Self-rating Anxiety Scale (SAS), introduced by Zung, has been widely used in research and in clinical practice for the detection of anxiety. The present study aims at standardizing the Greek version of SAS. SAS consists of 20 items rated on a 1-4 likert type scale. The total SAS score may vary from 20 (no anxiety at all) to 80 (severe anxiety). Two hundred and fifty four participants (114 male and 140 female), psychiatric patients, physically ill and general population individuals, aged 45.40±11.35 years, completed the following: (a) a demographic characteristics' questionnaire, (b) the SAS Greek version, (c) the Spielberg's Modified Greek State-Trait Anxiety Scale (STAI-Gr.-X) and (d) the Zung Depression Rating Scale (ZDRS). Seventy six participants answered the SAS twice within a 12th-day median period of time. The following parameters were calculated: (a) internal consistency of the SAS in terms of Cronbach's α co-efficient, (b) its test-retest reliability in terms of the Intraclass Correlation Coefficient (ICC) and (c) its concurrent and convergent validities through its score's Spearman's rho correlations with both the state and trait subscales of STAI-Gr X and the ZDRS. In addition, in order to evaluate SAS' discriminant validity, the scale's scores of the three groups of participants (psychiatric patients, physically ill and general population individuals) were compared among each other, in terms of Kruskall Wallis and Mann Whitney U tests. SAS Cronbach's alpha equals 0.897 while ICC regarding its test-retest reliability equals 0.913. Spearman's rho concerning validity: (a) when SAS is compared to STAI-Gr.-X (state), equals it 0.767, (b) when SAS is compared to STAI-Gr. X (trait), it equals 0.802 and (c) when SAS is compared to ZDRS, it equals 0.835. The mentally ill scored significantly higher in SAS compared to both the healthy and the general population. In conclusion, the SAS Greek version presents very satisfactory psychometric properties regarding

  13. SAS-1 is a C2 domain protein critical for centriole integrity in C. elegans.

    Science.gov (United States)

    von Tobel, Lukas; Mikeladze-Dvali, Tamara; Delattre, Marie; Balestra, Fernando R; Blanchoud, Simon; Finger, Susanne; Knott, Graham; Müller-Reichert, Thomas; Gönczy, Pierre

    2014-11-01

    Centrioles are microtubule-based organelles important for the formation of cilia, flagella and centrosomes. Despite progress in understanding the underlying assembly mechanisms, how centriole integrity is ensured is incompletely understood, including in sperm cells, where such integrity is particularly critical. We identified C. elegans sas-1 in a genetic screen as a locus required for bipolar spindle assembly in the early embryo. Our analysis reveals that sperm-derived sas-1 mutant centrioles lose their integrity shortly after fertilization, and that a related defect occurs when maternal sas-1 function is lacking. We establish that sas-1 encodes a C2 domain containing protein that localizes to centrioles in C. elegans, and which can bind and stabilize microtubules when expressed in human cells. Moreover, we uncover that SAS-1 is related to C2CD3, a protein required for complete centriole formation in human cells and affected in a type of oral-facial-digital (OFD) syndrome.

  14. SAS-1 is a C2 domain protein critical for centriole integrity in C. elegans.

    Directory of Open Access Journals (Sweden)

    Lukas von Tobel

    2014-11-01

    Full Text Available Centrioles are microtubule-based organelles important for the formation of cilia, flagella and centrosomes. Despite progress in understanding the underlying assembly mechanisms, how centriole integrity is ensured is incompletely understood, including in sperm cells, where such integrity is particularly critical. We identified C. elegans sas-1 in a genetic screen as a locus required for bipolar spindle assembly in the early embryo. Our analysis reveals that sperm-derived sas-1 mutant centrioles lose their integrity shortly after fertilization, and that a related defect occurs when maternal sas-1 function is lacking. We establish that sas-1 encodes a C2 domain containing protein that localizes to centrioles in C. elegans, and which can bind and stabilize microtubules when expressed in human cells. Moreover, we uncover that SAS-1 is related to C2CD3, a protein required for complete centriole formation in human cells and affected in a type of oral-facial-digital (OFD syndrome.

  15. USGS National Seismic Hazard Maps

    Science.gov (United States)

    Frankel, A.D.; Mueller, C.S.; Barnhard, T.P.; Leyendecker, E.V.; Wesson, R.L.; Harmsen, S.C.; Klein, F.W.; Perkins, D.M.; Dickman, N.C.; Hanson, S.L.; Hopper, M.G.

    2000-01-01

    The U.S. Geological Survey (USGS) recently completed new probabilistic seismic hazard maps for the United States, including Alaska and Hawaii. These hazard maps form the basis of the probabilistic component of the design maps used in the 1997 edition of the NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, prepared by the Building Seismic Safety Council arid published by FEMA. The hazard maps depict peak horizontal ground acceleration and spectral response at 0.2, 0.3, and 1.0 sec periods, with 10%, 5%, and 2% probabilities of exceedance in 50 years, corresponding to return times of about 500, 1000, and 2500 years, respectively. In this paper we outline the methodology used to construct the hazard maps. There are three basic components to the maps. First, we use spatially smoothed historic seismicity as one portion of the hazard calculation. In this model, we apply the general observation that moderate and large earthquakes tend to occur near areas of previous small or moderate events, with some notable exceptions. Second, we consider large background source zones based on broad geologic criteria to quantify hazard in areas with little or no historic seismicity, but with the potential for generating large events. Third, we include the hazard from specific fault sources. We use about 450 faults in the western United States (WUS) and derive recurrence times from either geologic slip rates or the dating of pre-historic earthquakes from trenching of faults or other paleoseismic methods. Recurrence estimates for large earthquakes in New Madrid and Charleston, South Carolina, were taken from recent paleoliquefaction studies. We used logic trees to incorporate different seismicity models, fault recurrence models, Cascadia great earthquake scenarios, and ground-motion attenuation relations. We present disaggregation plots showing the contribution to hazard at four cities from potential earthquakes with various magnitudes and

  16. First report of sasX-positive methicillin-resistant Staphylococcus aureus in Japan.

    Science.gov (United States)

    Nakaminami, Hidemasa; Ito, Teruyo; Han, Xiao; Ito, Ayumu; Matsuo, Miki; Uehara, Yuki; Baba, Tadashi; Hiramatsu, Keiichi; Noguchi, Norihisa

    2017-09-01

    SasX is a known virulence factor of Staphylococcus aureus involved in colonisation and immune evasion of the bacterium. The sasX gene, which is located on the ϕSPβ prophage, is frequently found in the sequence type (ST) 239 S. aureus lineage, which is the predominant healthcare-associated clone in Asian countries. In Japan, ST239 clones have rarely been identified, and sasX-positive strains have not been reported to date. Here, we report the first identification of 18 sasX-positive methicillin-resistant S. aureus (MRSA) strains in Japanese hospitals between 2009 and 2011. All sasX-positive isolates belonged to an ST239-staphylococcal cassette chromosome mec type III (ST239-III) lineage. However, we were unable to identify additional sasX-positive MRSA strains from 2012 to 2016, indicating that the small epidemic of sasX-positive isolates observed in this study was temporary. The sequence surrounding sasX in the strain TOHH628 lacked 51 genes that encode phage packaging and structural proteins, and no bacteriophage was induced by mitomycin C. Additionally, in the TOHH628 strain, the region (64.6 kb) containing sasX showed high identity to the ϕSPβ-like element (71.3 kb) of the Taiwanese MRSA strain Z172. The data strongly suggest that the present sasX-positive isolates found in Japanese hospitals were transmitted incidentally from other countries. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Seismic risk perception test

    Science.gov (United States)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro

    2013-04-01

    The perception of risks involves the process of collecting, selecting and interpreting signals about uncertain impacts of events, activities or technologies. In the natural sciences the term risk seems to be clearly defined, it means the probability distribution of adverse effects, but the everyday use of risk has different connotations (Renn, 2008). The two terms, hazards and risks, are often used interchangeably by the public. Knowledge, experience, values, attitudes and feelings all influence the thinking and judgement of people about the seriousness and acceptability of risks. Within the social sciences however the terminology of 'risk perception' has become the conventional standard (Slovic, 1987). The mental models and other psychological mechanisms which people use to judge risks (such as cognitive heuristics and risk images) are internalized through social and cultural learning and constantly moderated (reinforced, modified, amplified or attenuated) by media reports, peer influences and other communication processes (Morgan et al., 2001). Yet, a theory of risk perception that offers an integrative, as well as empirically valid, approach to understanding and explaining risk perception is still missing". To understand the perception of risk is necessary to consider several areas: social, psychological, cultural, and their interactions. Among the various research in an international context on the perception of natural hazards, it seemed promising the approach with the method of semantic differential (Osgood, C.E., Suci, G., & Tannenbaum, P. 1957, The measurement of meaning. Urbana, IL: University of Illinois Press). The test on seismic risk perception has been constructed by the method of the semantic differential. To compare opposite adjectives or terms has been used a Likert's scale to seven point. The test consists of an informative part and six sections respectively dedicated to: hazard; vulnerability (home and workplace); exposed value (with reference to

  18. Zinc-dependent mechanical properties of Staphylococcus aureus biofilm-forming surface protein SasG.

    Science.gov (United States)

    Formosa-Dague, Cécile; Speziale, Pietro; Foster, Timothy J; Geoghegan, Joan A; Dufrêne, Yves F

    2016-01-12

    Staphylococcus aureus surface protein SasG promotes cell-cell adhesion during the accumulation phase of biofilm formation, but the molecular basis of this interaction remains poorly understood. Here, we unravel the mechanical properties of SasG on the surface of living bacteria, that is, in its native cellular environment. Nanoscale multiparametric imaging of living bacteria reveals that Zn(2+) strongly increases cell wall rigidity and activates the adhesive function of SasG. Single-cell force measurements show that SasG mediates cell-cell adhesion via specific Zn(2+)-dependent homophilic bonds between β-sheet-rich G5-E domains on neighboring cells. The force required to unfold individual domains is remarkably strong, up to ∼500 pN, thus explaining how SasG can withstand physiological shear forces. We also observe that SasG forms homophilic bonds with the structurally related accumulation-associated protein of Staphylococcus epidermidis, suggesting the possibility of multispecies biofilms during host colonization and infection. Collectively, our findings support a model in which zinc plays a dual role in activating cell-cell adhesion: adsorption of zinc ions to the bacterial cell surface increases cell wall cohesion and favors the projection of elongated SasG proteins away from the cell surface, thereby enabling zinc-dependent homophilic bonds between opposing cells. This work demonstrates an unexpected relationship between mechanics and adhesion in a staphylococcal surface protein, which may represent a general mechanism among bacterial pathogens for activating cell association.

  19. SAS-6 assembly templated by the lumen of cartwheel-less centrioles precedes centriole duplication.

    Science.gov (United States)

    Fong, Chii Shyang; Kim, Minhee; Yang, T Tony; Liao, Jung-Chi; Tsou, Meng-Fu Bryan

    2014-07-28

    Centrioles are 9-fold symmetric structures duplicating once per cell cycle. Duplication involves self-oligomerization of the centriolar protein SAS-6, but how the 9-fold symmetry is invariantly established remains unclear. Here, we found that SAS-6 assembly can be shaped by preexisting (or mother) centrioles. During S phase, SAS-6 molecules are first recruited to the proximal lumen of the mother centriole, adopting a cartwheel-like organization through interactions with the luminal wall, rather than via their self-oligomerization activity. The removal or release of luminal SAS-6 requires Plk4 and the cartwheel protein STIL. Abolishing either the recruitment or the removal of luminal SAS-6 hinders SAS-6 (or centriole) assembly at the outside wall of mother centrioles. After duplication, the lumen of engaged mother centrioles becomes inaccessible to SAS-6, correlating with a block for reduplication. These results lead to a proposed model that centrioles may duplicate via a template-based process to preserve their geometry and copy number.

  20. Self-assembling SAS-6 multimer is a core centriole building block.

    Science.gov (United States)

    Gopalakrishnan, Jayachandran; Guichard, Paul; Smith, Andrew H; Schwarz, Heinz; Agard, David A; Marco, Sergio; Avidor-Reiss, Tomer

    2010-03-19

    Centrioles are conserved microtubule-based organelles with 9-fold symmetry that are essential for cilia and mitotic spindle formation. A conserved structure at the onset of centriole assembly is a "cartwheel" with 9-fold radial symmetry and a central tubule in its core. It remains unclear how the cartwheel is formed. The conserved centriole protein, SAS-6, is a cartwheel component that functions early in centriole formation. Here, combining biochemistry and electron microscopy, we characterize SAS-6 and show that it self-assembles into stable tetramers, which serve as building blocks for the central tubule. These results suggest that SAS-6 self-assembly may be an initial step in the formation of the cartwheel that provides the 9-fold symmetry. Electron microscopy of centrosomes identified 25-nm central tubules with repeating subunits and show that SAS-6 concentrates at the core of the cartwheel. Recombinant and native SAS-6 self-oligomerizes into tetramers with approximately 6-nm subunits, and these tetramers are components of the centrosome, suggesting that tetramers are the building blocks of the central tubule. This is further supported by the observation that elevated levels of SAS-6 in Drosophila cells resulted in higher order structures resembling central tubule morphology. Finally, in the presence of embryonic extract, SAS-6 tetramers assembled into high density complexes, providing a starting point for the eventual in vitro reconstruction of centrioles.

  1. SEISMIC GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091465 Cai Xuelin(College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China);Cao Jiamin Preliminary Study on the 3-D Crust Structure for the Longmen Lithosphere and the Genesis of the Huge Wenchuan Earthquake,Sichuan Province,China(Journal of Chengdu University of Technology,ISSN1671-9727,CN51-1634/N,35(4),2008,p.357-365,8 illus.,39 refs.)Key words:deep-seated structures,large earthquakes,Longmenshan Fracture ZoneBased on a structural analysis of many seismic sounding profiles,there are two fault systems in Longmen collisional orogenic belt,Sichuan Province,China.They are both different obviously and correlative closely.One is shallow fault system composed mainly of brittle shear zones in surface crust,and the other is deep fault system composed mainly of crust-mantle ductile shear zones cutting Moho discontinuity.Based on the result of researching geological structure and seismic sounding profiles,

  2. Seismic hazard estimation based on the distributed seismicity in northern China

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; SHI Bao-ping; SUN Liang

    2008-01-01

    In this paper, we have proposed an alternative seismic hazard modeling by using distributed seismicites. The distributed seismicity model does not need delineation of seismic source zones, and simplify the methodology of probabilistic seismic hazard analysis. Based on the devastating earthquake catalogue, we established three seismi- city model, derived the distribution of a-value in northern China by using Gaussian smoothing function, and cal- culated peak ground acceleration distributions for this area with 2%, 5% and 10% probability of exceedance in a 50-year period by using three attenuation models, respectively. In general, the peak ground motion distribution patterns are consistent with current seismic hazard map of China, but in some specific seismic zones which in- clude Shanxi Province and Shijiazhuang areas, our results indicated a little bit higher peak ground motions and zonation characters which are in agreement with seismicity distribution patterns in these areas. The hazard curves have been developed for Beijing, Tianjin, Taiyuan, Tangshan, and Ji'nan, the metropolitan cities in the northern China. The results showed that Tangshan, Taiyuan, Beijing has a higher seismic hazard than that of other cities mentioned above.

  3. An adaptive noise attenuation method for edge and amplitude preservation

    Institute of Scientific and Technical Information of China (English)

    Cai Han-Peng; He Zhen-Hua; Li Ya-Lin; He Guang-Ming; Zou Wen; Zhang Dong-Jun; Liu Pu

    2014-01-01

    Noise intensity distributed in seismic data varies with different frequencies or frequency bands; thus, noise attenuation on the full-frequency band affects the dynamic properties of the seismic reflection signal and the subsequent seismic data interpretation, reservoir description, hydrocarbon detection, etc. Hence, we propose an adaptive noise attenuation method for edge and amplitude preservation, wherein the wavelet packet transform is used to decompose the full-band seismic signal into multiband data and then process these data using nonlinear anisotropic dip-oriented edge-preservingfi ltering. In the fi ltering, the calculated diffusion tensor from the structure tensor can be exploited to establish the direction of smoothing. In addition, the fault confidence measure and discontinuity operator can be used to preserve the structural and stratigraphic discontinuities and edges, and the decorrelation criteria can be used to establish the number of iterations. These parameters can minimize the intervention and subjectivity of the interpreter, and simplify the application of the proposed method. We applied the proposed method to synthetic and real 3D marine seismic data. We found that the proposed method could be used to attenuate noise in seismic data while preserving the effective discontinuity information and amplitude characteristics in seismic refl ection waves, providing high-quality data for interpretation and analysis such as high-resolution processing, attribute analysis, and inversion.

  4. [Generating person-years and calculating SMR using SAS: a simple program for exact calculations].

    Science.gov (United States)

    Marchand, J-L

    2010-10-01

    The computation of standardized incidence/mortality ratios or Poisson regression requires the calculation of person-years generated in a cohort. Softwares can do that, but SAS users still need to program this step themselves. Various algorithms were published previously, but they do not perform exact calculations: the present paper describes a simple program, which creates exact person-years, and computes SMRs. This program provides a referenced tool to perform this analysis in a cohort, with SAS or another language (the algorithm used can be easily adapted). Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  5. SAS paneb Estonian Airi kiirmüüki / Gert D. Hankewitz

    Index Scriptorium Estoniae

    Hankewitz, Gert D.

    2009-01-01

    Majandusraskustes lennufirma SAS kavatseb loobuda osalustest kõigis lennufirmades, mis ei sobi kokku nende uue tegevuskavaga. Majandus- ja kommunikatsiooniminister Juhan Parts arvab, et riik peaks leidma Estonian Airile kodumaised partnerid

  6. Physicochemical properties and oral bioavailability of ursolic acid nanoparticles using supercritical anti-solvent (SAS) process.

    Science.gov (United States)

    Yang, Lei; Sun, Zhen; Zu, Yuangang; Zhao, Chunjian; Sun, Xiaowei; Zhang, Zhonghua; Zhang, Lin

    2012-05-01

    The objective of the study was to prepare ursolic acid (UA) nanoparticles using the supercritical anti-solvent (SAS) process and evaluate its physicochemical properties and oral bioavailability. The effects of four process variables, pressure, temperature, drug concentration and drug solution flow rate, on drug particle formation during SAS process, were investigated. Particles with mean particle size ranging from 139.2±19.7 to 1039.8±65.2nm were obtained by varying the process parameters. The UA was characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, specific surface area, dissolution test and bioavailability test. It was concluded that physicochemical properties and bioavailability of crystalline UA could be improved by physical modification, such as particle size reduction and generation of amorphous state using SAS process. Further, SAS process was a powerful methodology for improving the physicochemical properties and bioavailability of UA.

  7. SAS ihub hammast Estonian Airile / Lauri Linnamäe, Meeli Vilukas

    Index Scriptorium Estoniae

    Linnamäe, Lauri

    2007-01-01

    Skandinaavia lennukompanii SAS soovib suurendada osalust Estonian Airis ja Läti airBalticus, soovides luua Baltimaade tugevaima lennufirma. Peaminister Andrus Ansipi sõnul on Eesti kaalunud oma osaluse müüki Estonian Airis. Lisa: Omanikering

  8. Reactivity and fate of secondary alkane sulfonates (SAS) in marine sediments.

    Science.gov (United States)

    Baena-Nogueras, Rosa María; Rojas-Ojeda, Patricia; Sanz, José Luis; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2014-06-01

    This research is focused on secondary alkane sulfonates (SAS), anionic surfactants widely used in household applications that access aquatic environments mainly via sewage discharges. We studied their sorption capacity and anaerobic degradation in marine sediments, providing the first data available on this topic. SAS partition coefficients increased towards those homologues having longer alkyl chains (from up to 141 L kg(-1) for C14 to up to 1753 L kg(-1) for C17), which were those less susceptible to undergo biodegradation. Overall, SAS removal percentages reached up to 98% after 166 days of incubation using anoxic sediments. The degradation pathway consisted on the formation of sulfocarboxylic acids after an initial fumarate attack of the alkyl chain and successive β-oxidations. This is the first study showing that SAS can be degraded in absence of oxygen, so this new information should be taken into account for future environmental risk assessments on these chemicals.

  9. Quantitative Seismic Amplitude Analysis

    OpenAIRE

    Dey, A. K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Currently, the seismic value chain paradigm is in a feed-forward mode. Modern seismic data now have the potential to yield the best images in terms of spatial resolution, amplitude accuracy, and incre...

  10. SAS 2 observation of pulsed high-energy gamma radiation from Geminga

    Science.gov (United States)

    Mattox, J. R.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.

    1992-01-01

    Following the detection of pulsed X-rays and gamma rays from Geminga, the 1972-1973 SAS 2 data which first revealed this source have been reanalyzed. The 237 ms periodicity is visible in those observations. The phase of the SAS 2 periodicity is consistent with that of COS B suggesting that the gamma-ray data allow an accounting for every revolution of the Geminga pulsar between 1972 and 1982.

  11. Comparative assessment of SAS and DES turbulence modeling for massively separated flows

    Science.gov (United States)

    Zheng, Weilin; Yan, Chao; Liu, Hongkang; Luo, Dahai

    2016-02-01

    Numerical studies of the flow past a circular cylinder at Reynolds number 1.4× 105 and NACA0021 airfoil at the angle of attack 60° have been carried out by scale-adaptive simulation (SAS) and detached eddy simulation (DES), in comparison with the existing experimental data. The new version of the model developed by Egorov and Menter is assessed, and advantages and disadvantages of the SAS simulation are analyzed in detail to provide guidance for industrial application in the future. Moreover, the mechanism of the scale-adaptive characteristics in separated regions is discussed, which is obscure in previous analyses. It is concluded that: the mean flow properties satisfactorily agree with the experimental results for the SAS simulation, although the prediction of the second order turbulent statistics in the near wake region is just reasonable. The SAS model can produce a larger magnitude of the turbulent kinetic energy in the recirculation bubble, and, consequently, a smaller recirculation region and a more rapid recovery of the mean velocity outside the recirculation region than the DES approach with the same grid resolution. The vortex shedding is slightly less irregular with the SAS model than with the DES approach, probably due to the higher dissipation of the SAS simulation under the condition of the coarse mesh.

  12. SAS-6 engineering reveals interdependence between cartwheel and microtubules in determining centriole architecture.

    Science.gov (United States)

    Hilbert, Manuel; Noga, Akira; Frey, Daniel; Hamel, Virginie; Guichard, Paul; Kraatz, Sebastian H W; Pfreundschuh, Moritz; Hosner, Sarah; Flückiger, Isabelle; Jaussi, Rolf; Wieser, Mara M; Thieltges, Katherine M; Deupi, Xavier; Müller, Daniel J; Kammerer, Richard A; Gönczy, Pierre; Hirono, Masafumi; Steinmetz, Michel O

    2016-04-01

    Centrioles are critical for the formation of centrosomes, cilia and flagella in eukaryotes. They are thought to assemble around a nine-fold symmetric cartwheel structure established by SAS-6 proteins. Here, we have engineered Chlamydomonas reinhardtii SAS-6-based oligomers with symmetries ranging from five- to ten-fold. Expression of a SAS-6 mutant that forms six-fold symmetric cartwheel structures in vitro resulted in cartwheels and centrioles with eight- or nine-fold symmetries in vivo. In combination with Bld10 mutants that weaken cartwheel-microtubule interactions, this SAS-6 mutant produced six- to eight-fold symmetric cartwheels. Concurrently, the microtubule wall maintained eight- and nine-fold symmetries. Expressing SAS-6 with analogous mutations in human cells resulted in nine-fold symmetric centrioles that exhibited impaired length and organization. Together, our data suggest that the self-assembly properties of SAS-6 instruct cartwheel symmetry, and lead us to propose a model in which the cartwheel and the microtubule wall assemble in an interdependent manner to establish the native architecture of centrioles.

  13. Preparation and pharmaceutical characterization of amorphous cefdinir using spray-drying and SAS-process.

    Science.gov (United States)

    Park, Junsung; Park, Hee Jun; Cho, Wonkyung; Cha, Kwang-Ho; Kang, Young-Shin; Hwang, Sung-Joo

    2010-08-30

    The aim of this study was to investigate the effects of micronization and amorphorization of cefdinir on solubility and dissolution rate. The amorphous samples were prepared by spray-drying (SD) and supercritical anti-solvent (SAS) process, respectively and their amorphous natures were confirmed by DSC, PXRD and FT-IR. Thermal gravimetric analysis was performed by TGA. SEM was used to investigate the morphology of particles and the processed particle had a spherical shape, while the unprocessed crystalline particle had a needle-like shape. The mean particle size and specific surface area were measured by dynamic light scattering (DLS) and BET, respectively. The DLS result showed that the SAS-processed particle was the smallest, followed by SD and the unprocessed cefdinir. The BET result was the same as DLS result in that the SAS-processed particle had the largest surface area. Therefore, the processed cefdinir, especially the SAS-processed particle, appeared to have enhanced apparent solubility, improved intrinsic dissolution rate and better drug release when compared with SD-processed and unprocessed crystalline cefdinir due not only to its amorphous nature, but also its reduced particle size. Conclusions were that the solubility and dissolution rate of crystalline cefdinir could be improved by physically modifying the particles using SD and SAS-process. Furthermore, SAS-process was a powerful methodology for improving the solubility and dissolution rate of cefdinir.

  14. Different Effects of Startling Acoustic Stimuli (SAS) on TMS-Induced Responses at Rest and during Sustained Voluntary Contraction.

    Science.gov (United States)

    Chen, Yen-Ting; Li, Shengai; Zhou, Ping; Li, Sheng

    2016-01-01

    Previous studies have shown that a habituated startling acoustic stimulus (SAS) can cause a transient suppression of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) during light muscle contraction. However, it is still unknown whether this phenomenon persists when at rest or during a sustained voluntary contraction task. Therefore, the purpose of this study was to determine whether a conditioning SAS has different effects. TMS was delivered to the hot spot for the left biceps on 11 subjects at rest both with and without a conditioning SAS. Of the 11subjects, 9 also had TMS delivered during isometric flexion of the left elbow, also with and without a conditioning SAS. TMS-induced MEPs, TMS-induced force, and silent periods were used to determine the effect of conditioning SAS. Consistent with previous findings, TMS-induced MEPs were smaller with a conditioning SAS (0.49 ± 0.37 mV) as compared without the SAS (0.69 ± 0.52 mV) at rest. However, a conditioning SAS during the voluntary contraction tasks resulted in a significant shortening of the MEP silent period (187.22 ± 22.99 ms with SAS vs. 200.56 ± 29.71 ms without SAS) without any changes in the amplitude of the MEP (1.37 ± 0.9 mV with SAS V.S. 1.32 ± 0.92 mV without SAS) or the TMS-induced force (3.11 ± 2.03 N-m with SAS V.S. 3.62 ± 1.33 N-m without SAS). Our results provide novel evidence that a conditioning SAS has different effects on the excitability of the motor cortex when at rest or during sustained voluntary contractions.

  15. STUDY ON INELASTIC ATTENUATION AND SITE RESPONSE OF EACH STATION IN NINGXIA AREA BY USING WAVEFORM DATA FROM DIGITAL SEISMIC STATION NETWORK%利用数字地震波资料研究宁夏地区介质非弹性衰减和场地响应

    Institute of Scientific and Technical Information of China (English)

    许英才; 许文俊; 李鸿庭; 陈继锋

    2011-01-01

    268 pieces of digital oscillograms of 32 seismic events of form ML.2.6 to ML4.9 recorded at 20 seismologic stations located on Ningxia region and its adjacent areas occurred from May, 2009 to Oct. , 2010 were studied and the relation of inelastic attenuation Q value with media frequency in the crust of this area, the site responses of 20 stations were calculated with the genetic algorithm. The results indicate that the frequency-dependent relation of inelastic attenuation value Q in the studied area is estimated as: Q(f) = 337.67f0.4554. The Q value is close to the regional result in Shanxi and Zhejiang. It probably indicate that the geological tectonic activity is in a normal level.%利用宁夏及邻区的数字地震波资料,选取2009-05-2010-10月M_L2.6以上的20个台站32次地震事件的268条波形记录,用遗传算法反演了宁夏及邻区介质非弹性衰减系数和台站场地相应.反演得到:宁夏地区介质非弹性衰减Q值与频率的关系为Q(f)=337.67f0.4554.其Q值和山西及浙江地区的结果最相近,可能预示着该区地质构造活动处于一个正常的活动水平.

  16. Seismic spatial wavefield gradient and rotational rate measurements as new observables in land seismic exploration

    Science.gov (United States)

    Schmelzbach, Cedric; Sollberger, David; Van Renterghem, Cédéric; Häusler, Mauro; Robertsson, Johan; Greenhalgh, Stewart

    2016-04-01

    Traditionally, land-seismic data acquisition is conducted using vertical-component sensors. A more complete representation of the seismic wavefield can be obtained by employing multicomponent sensors recording the full vector wavefield. If groups of multicomponent sensors are deployed, then spatial seismic wavefield gradients and rotational rates can be estimated by differencing the outputs of closely spaced sensors. Such data capture all six degrees of freedom of a rigid body (three components of translation and three components of rotation), and hence allow an even more complete representation of the seismic wavefield compared to single station triaxial data. Seismic gradient and rotation data open up new possibilities to process land-seismic data. Potential benefits and applications of wavefield gradient data include local slowness estimation, improved arrival identification, wavefield separation and noise suppression. Using synthetic and field data, we explored the reliability and sensitivity of various multicomponent sensor layouts to estimate seismic wavefield gradients and rotational rates. Due to the wavelength and incidence-angle dependence of sensor-group reception patterns as a function of the number of sensors, station spacing and layout, one has to counterbalance the impacts of truncation errors, random noise attenuation, and sensitivity to perturbations such as amplitude variations and positioning errors when searching for optimum receiver configurations. Field experiments with special rotational rate sensors were used to verify array-based rotational-rate estimates. Seismic wavefield gradient estimates and inferred wavefield attributes such as instantaneous slowness enable improved arrival identification, e.g. wave type and path. Under favorable conditions, seismic-wavefield gradient attributes can be extracted from conventional vertical-component data and used to, for example, enhance the identification of shear waves. A further promising

  17. Seismic monitoring at the Geysers Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Romero, A.E. Jr.; Kirkpatrick, A.; Majer, E.L.; Peterson, J.E. Jr.

    1994-09-01

    This report summarizes the efforts of LBL to utilize MEQ data in reservoir definition as well as in evaluating its performance. Results of the study indicate that the velocity and attenuation variations correlate with the known geology of the field. At the NW Geysers, high velocity anomalies correspond to metagraywacke and greenstone units while low velocity anomalies seem to be associated with Franciscan melanges. Low Vp/Vs and high attenuation delineate the steam reservoir suggesting undersaturation of the reservoir rocks. Ongoing monitoring of Vp/Vs may be useful in tracking the expansion of the steam zone with time. Spatial and temporal patterns of seismicity exhibit compelling correlation with geothermal exploitation. Clusters of MEQs occur beneath active injection wells and appear to shift with changing injection activities. High resolution MEQ locations hold promise for inferring fluid flow paths, especially in tracking injectate. This study has demonstrated that continuous seismic monitoring may be useful as an active reservoir management tool.

  18. Studies on seismic waves

    Institute of Scientific and Technical Information of China (English)

    张海明; 陈晓非

    2003-01-01

    The development of seismic wave study in China in the past four years is reviewed. The discussion is divided into several aspects, including seismic wave propagation in laterally homogeneous media, laterally heterogeneous media, anisotropic and porous media, surface wave and seismic wave inversion, and seismic wave study in prospecting and logging problems. Important projects in the current studies on seismic wave is suggested as the development of high efficient numerical methods, and applying them to the studies of excitation and propagation of seismic waves in complex media and strong ground motion, which will form a foundation for refined earthquake hazard analysis and prediction.

  19. Conserved TCP domain of Sas-4/CPAP is essential for pericentriolar material tethering during centrosome biogenesis.

    Science.gov (United States)

    Zheng, Xiangdong; Gooi, Li Ming; Wason, Arpit; Gabriel, Elke; Mehrjardi, Narges Zare; Yang, Qian; Zhang, Xingrun; Debec, Alain; Basiri, Marcus L; Avidor-Reiss, Tomer; Pozniakovsky, Andrei; Poser, Ina; Saric, Tomo; Hyman, Anthony A; Li, Haitao; Gopalakrishnan, Jay

    2014-01-21

    Pericentriolar material (PCM) recruitment to centrioles forms a key step in centrosome biogenesis. Deregulation of this process leads to centrosome aberrations causing disorders, one of which is autosomal recessive primary microcephaly (MCPH), a neurodevelopmental disorder where brain size is reduced. During PCM recruitment, the conserved centrosomal protein Sas-4/CPAP/MCPH6, known to play a role in centriole formation, acts as a scaffold for cytoplasmic PCM complexes to bind and then tethers them to centrioles to form functional centrosomes. To understand Sas-4's tethering role, we determined the crystal structure of its T complex protein 10 (TCP) domain displaying a solvent-exposed single-layer of β-sheets fold. This unique feature of the TCP domain suggests that it could provide an "extended surface-like" platform to tether the Sas-4-PCM scaffold to a centriole. Functional studies in Drosophila, human cells, and human induced pluripotent stem cell-derived neural progenitor cells were used to test this hypothesis, where point mutations within the 9-10th β-strands (β9-10 mutants including a MCPH-associated mutation) perturbed PCM tethering while allowing Sas-4/CPAP to scaffold cytoplasmic PCM complexes. Specifically, the Sas-4 β9-10 mutants displayed perturbed interactions with Ana2, a centrosome duplication factor, and Bld-10, a centriole microtubule-binding protein, suggesting a role for the β9-10 surface in mediating protein-protein interactions for efficient Sas-4-PCM scaffold centriole tethering. Hence, we provide possible insights into how centrosomal protein defects result in human MCPH and how Sas-4 proteins act as a vehicle to tether PCM complexes to centrioles independent of its well-known role in centriole duplication.

  20. Study of Attenuation Characteristics,Site Response and Seismic Source Parameters of the Pubugou Reservoir Region%瀑布沟水库库区介质衰减、台站响应和震源参数研究

    Institute of Scientific and Technical Information of China (English)

    乔慧珍; 张永久

    2014-01-01

    利用数字地震台网2007年1月到2011年12月记录到的瀑布沟水库及邻区地震波形资料,采用 Atkinson 方法计算了库区介质品质因子;并利用 Moya 方法计算了台站场地响应;在获得介质品质因子和台站场地响应的基础上联合反演计算了瀑布沟库区67次构造地震和208次爆破地震的震源波谱参数,同时讨论了它们的时空特征。结果表明:瀑布沟库区 Q 值与频率的关系为 Q (f )=47.1*f 0%On the basis of digital seismograms recorded by the Pubugou reservoir digital seismic network,we obtained the nonelastic coefficient of Pubugou reservoir area by using the method proposed by Atkinson.The site response of each station was obtained by using the Moya method. The frequency-dependent Q (f )at the reservoir area is estimated as Q (f )=47.1 *f 0 .92 ;the site response of each station is approximately 1.0,showing little amplification.On the basis of the Q (f )and the site responses,we detected approximately 67 tectonic earthquakes and 208 source pa-rameters of blasting shocks by using the Atkinson inversion method.The results show obvious differences in the source parameters of the tectonic earthquakes and blast shocks.The parameters near the reservoir dam area and Hanyuan County were lower because of the blasting vibration.

  1. Atmospheric-Seismic Effect of Chelyabinsk Meteoroid

    Science.gov (United States)

    Chernogor, L. F.

    2017-06-01

    Purpose: The parameters of the shock-wave source in the atmosphere and seismic oscillations that this source caused are investigated Design/methodology/approach: The atmospheric and seismic processes caused by the passage and explosion of Chelyabinsk meteoroid on February 15, 2013 have been modelled. The model results are compared with the observation results obtained at several seismic stations. Findings: The shock-wave impact duration is shown to be equal to approximately 97 s, and the time delays of the shockwave at the sites of destruction relative to its generation time at altitudes of 23÷53 km are shown to be equal to 77÷295 s in the distance range interval of 23÷84 km. The length of the area destructed by the shock with the access pressure of no less than 0.7 kPa is determined to be equal to 125÷130 km, and its width to 16÷60 km at various parts of the meteoroid path. The regression relation between the duration of the seismic signal and the length of the seismic wave path has been determined. The characteristic scale time of seismic source impact is equal to approximately 40 s. In the 20÷50 -s period range of seismic oscillations, the dependence of the group speed on period is established. The attenuation depth of seismic waves is estimated to be approximately 10÷20 Mm in the frequency range of 0.25÷3.0 Hz, and the Earth’s crust speed to 5.7÷7.0 μm/s. Conclusions: The model and estimation results are in good agreement with the observations.

  2. Monitoring temporal changes of seismic properties

    Directory of Open Access Journals (Sweden)

    Yosuke eAoki

    2015-07-01

    Full Text Available Temporal changes of seismic properties, such as velocity, attenuation, anisotropy, and scattering properties, have been inferred by active methods for decades and more recently by passive methods. In particular, passive methods are capable of monitoring seismic properties because they do not require earthquakes but rely on continuously excited signals in the ocean, for example. A collection of continuous monitoring of seismic velocities has revealed that the susceptibility of velocity changes to stress perturbations are highly variable. These variations can be translated to variability of third-order elastic moduli, elastic moduli arising by considering finite deformation. The third-order elastic moduli are shown by theoretical studies to be a good indicator of granular properties of rocks and, in general, as to how fluids interact with solid rocks. Advancement of theoretical and observational studies will gain more insights into the nature of third-order elastic moduli, which will eventually become yet another parameters to characterize the properties of rocks.

  3. SEISMIC MODELING ENGINES PHASE 1 FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    BRUCE P. MARION

    2006-02-09

    Seismic modeling is a core component of petroleum exploration and production today. Potential applications include modeling the influence of dip on anisotropic migration; source/receiver placement in deviated-well three-dimensional surveys for vertical seismic profiling (VSP); and the generation of realistic data sets for testing contractor-supplied migration algorithms or for interpreting AVO (amplitude variation with offset) responses. This project was designed to extend the use of a finite-difference modeling package, developed at Lawrence Berkeley Laboratories, to the advanced applications needed by industry. The approach included a realistic, easy-to-use 2-D modeling package for the desktop of the practicing geophysicist. The feasibility of providing a wide-ranging set of seismic modeling engines was fully demonstrated in Phase I. The technical focus was on adding variable gridding in both the horizontal and vertical directions, incorporating attenuation, improving absorbing boundary conditions and adding the optional coefficient finite difference methods.

  4. New Shortwave Array Spectroradiometer-Hemispheric (SAS-He): Hyperspectral Design and Initial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kassianov, Evgueni I.; Flynn, Connor J M.; Barnard, James C.; Ermold, Brian D.; Berg, Larry K.

    2016-10-31

    Aerosol optical depth (AOD) derived from hyperspectral measurements can serve as an invaluable input for simultaneous retrievals of particle size distributions and major trace gases. The required hyperspectral measurements are provided by a new ground-based radiometer, the so-called Shortwave Array Spectroradiometer-Hemispheric (SAS-He), recently developed with support from the Department of Energy (DOE) Office Atmospheric Radiation Measurement (ARM) Program. The SAS-He has wide spectral coverage (350-1700nm) and high spectral resolution: about 2.4 nm and 6 nm within 350-1000 nm and 970-1700 nm spectral ranges, respectively. To illustrate an initial performance of the SAS-He, we take advantage of integrated dataset collected during the ARM-supported Two-Column Aerosol Project (TCAP) over the US coastal region (Cape Cod, Massachusetts). This dataset includes AODs derived using data from Aerosol Robotic Network (AERONET) sunphotometer and Multi-Filter Rotating Shadowband Radiometer (MFRSR). We demonstrate that, on average, the SAS-He AODs closely match the MFRSR and AERONET AODs in the ultraviolet and visible spectral ranges for this area with highly variable AOD. Also, we discuss corrections of SAS-He total optical depth for gas absorption in the near-infrared spectral range and their operational implementation.

  5. SAS/IntrNet功能简介及初步应用

    Institute of Scientific and Technical Information of China (English)

    杨舒静; 刘沛

    2014-01-01

    目的 介绍统计分析软件(statistical analysis system,SAS)网络化模块(SAS/IntrNet)的基本功能并应用于医学实际.方法 应用SAS/IntrNet远程调用SAS程序进行在线分析,从客户端获取参数通过网络传递给服务器端的SAS程序进行分析,并反馈结果给客户端.结果 利用SAS/IntrNet程序处理流程和相关配置文件,成功地实现了在线膳食暴露评估分析实例,使得用户可以在不安装SAS软件的情况下方便地通过网页进行在线SAS统计分析.结论 利用SAS/IntrNet模块实现SAS网络化应用,可使不甚了解SAS编程的使用者通过友好的访问界面即可实现SAS的在线统计分析,大大提高了SAS系统信息共享的能力.

  6. Centriolar SAS-7 acts upstream of SPD-2 to regulate centriole assembly and pericentriolar material formation.

    Science.gov (United States)

    Sugioka, Kenji; Hamill, Danielle R; Lowry, Joshua B; McNeely, Marie E; Enrick, Molly; Richter, Alyssa C; Kiebler, Lauren E; Priess, James R; Bowerman, Bruce

    2017-01-16

    The centriole/basal body is a eukaryotic organelle that plays essential roles in cell division and signaling. Among five known core centriole proteins, SPD-2/Cep192 is the first recruited to the site of daughter centriole formation and regulates the centriolar localization of the other components in C. elegans and in humans. However, the molecular basis for SPD-2 centriolar localization remains unknown. Here we describe a new centriole component, the coiled-coil protein SAS-7, as a regulator of centriole duplication, assembly and elongation. We also show that SAS-7 binds SPD-2 and regulates SPD-2 centriolar recruitment, while SAS-7 centriolar localization is SPD-2-independent. Furthermore, pericentriolar material (PCM) formation is abnormal in sas-7 mutants, and the PCM-dependent induction of cell polarity that defines the anterior-posterior body axis frequently fails. We conclude that SAS-7 functions at the earliest step in centriole duplication yet identified and plays important roles in the orchestration of centriole and PCM assembly.

  7. Determination and occurrence of secondary alkane sulfonates (SAS) in aquatic environments.

    Science.gov (United States)

    Baena-Nogueras, Rosa María; González-Mazo, Eduardo; Lara-Martín, Pablo A

    2013-05-01

    A new methodology has been developed for the determination of secondary alkane sulfonates (SAS), an anionic surfactant, in environmental matrices. Sediment and sludge samples were extracted using pressurized liquid extraction and sonication, whereas wastewater and surface water samples were processed using solid-phase extraction. Extraction recoveries were acceptable for both aqueous (78-120%) and solid samples (83-100%). Determination of SAS was carried out by high or ultra performance liquid chromatography - mass spectrometry using ion trap and time-of-flight detectors. The methodology was applied to samples from Guadalete River (SW Spain), where SAS concentrations below 1 μg L(-1) were measured in surface water, and from 72 to 9737 μg kg(-1) in sediments. Differential partitioning was observed for SAS homologues as those having a longer hydrocarbon chain which preferentially sorbed onto particulate matter. A preliminary environmental risk assessment also showed that SAS measured levels were not harmful to the aquatic community in the sampling area.

  8. Sas-4 provides a scaffold for cytoplasmic complexes and tethers them in a centrosome.

    Science.gov (United States)

    Gopalakrishnan, Jayachandran; Mennella, Vito; Blachon, Stephanie; Zhai, Bo; Smith, Andrew H; Megraw, Timothy L; Nicastro, Daniela; Gygi, Steven P; Agard, David A; Avidor-Reiss, Tomer

    2011-06-21

    Centrosomes are conserved organelles that are essential for accurate cell division and cilium formation. A centrosome consists of a pair of centrioles surrounded by a protein network of pericentriolar material (PCM) that is essential for the centrosome's function. In this study, we show that Sas-4 provides a scaffold for cytoplasmic complexes (named S-CAP), which include CNN, Asl and D-PLP, proteins that are all found in the centrosomes at the vicinity of the centriole. When Sas-4 is absent, nascent procentrioles are unstable and lack PCM, and functional centrosomes are not generated. When Sas-4 is mutated, so that it cannot form S-CAP complexes, centrosomes are present but with dramatically reduced levels of PCM. Finally, purified S-CAP complexes or recombinant Sas-4 can bind centrosomes stripped of PCM, whereas recombinant CNN or Asl cannot. In summary, PCM assembly begins in the cytosol where Sas-4 provides a scaffold for pre-assembled cytoplasmic complexes before tethering of the complexes in a centrosome.

  9. SAS-Pro: simultaneous residue assignment and structure superposition for protein structure alignment.

    Science.gov (United States)

    Shah, Shweta B; Sahinidis, Nikolaos V

    2012-01-01

    Protein structure alignment is the problem of determining an assignment between the amino-acid residues of two given proteins in a way that maximizes a measure of similarity between the two superimposed protein structures. By identifying geometric similarities, structure alignment algorithms provide critical insights into protein functional similarities. Existing structure alignment tools adopt a two-stage approach to structure alignment by decoupling and iterating between the assignment evaluation and structure superposition problems. We introduce a novel approach, SAS-Pro, which addresses the assignment evaluation and structure superposition simultaneously by formulating the alignment problem as a single bilevel optimization problem. The new formulation does not require the sequentiality constraints, thus generalizing the scope of the alignment methodology to include non-sequential protein alignments. We employ derivative-free optimization methodologies for searching for the global optimum of the highly nonlinear and non-differentiable RMSD function encountered in the proposed model. Alignments obtained with SAS-Pro have better RMSD values and larger lengths than those obtained from other alignment tools. For non-sequential alignment problems, SAS-Pro leads to alignments with high degree of similarity with known reference alignments. The source code of SAS-Pro is available for download at http://eudoxus.cheme.cmu.edu/saspro/SAS-Pro.html.

  10. New Shortwave Array Spectroradiometer-Hemispheric (SAS-He): hyperspectral design and initial applications

    Science.gov (United States)

    Kassianov, Evgueni; Flynn, Connor; Barnard, James; Ermold, Brian; Berg, Larry

    2016-10-01

    Aerosol optical depth (AOD) derived from hyperspectral measurements can serve as an invaluable input for simultaneous retrievals of particle size distributions and major trace gases. The required hyperspectral measurements are provided by a new ground-based radiometer, the so-called Shortwave Array Spectroradiometer-Hemispheric (SAS-He), recently developed with support from the Department of Energy (DOE) Office Atmospheric Radiation Measurement (ARM) Program. The SAS-He has wide spectral coverage (350-1700nm) and high spectral resolution: about 2.4 nm and 6 nm within 350-1000 nm and 970-1700 nm spectral ranges, respectively. To illustrate an initial performance of the SAS-He, we take advantage of integrated dataset collected during the ARM-supported Two-Column Aerosol Project (TCAP) over the US coastal region (Cape Cod, Massachusetts). This dataset includes AODs derived using data from Aerosol Robotic Network (AERONET) sunphotometer and Multi-Filter Rotating Shadowband Radiometer (MFRSR). We demonstrate that, on average, the SAS-He AODs closely match the MFRSR and AERONET AODs in the ultraviolet and visible spectral ranges for this area with highly variable AOD. Also, we discuss corrections of SAS-He total optical depth for gas absorption in the near-infrared spectral range and their operational implementation

  11. Spanish Validation of the School Anxiety Scale-Teacher Report (SAS-TR).

    Science.gov (United States)

    Orgilés, Mireia; Fernández-Martínez, Iván; Lera-Miguel, Sara; Marzo, Juan Carlos; Medrano, Laura; Espada, José Pedro

    2016-11-04

    This study aimed to examine the factorial structure and psychometric properties of the School Anxiety Scale-Teacher Report (SAS-TR) in a community sample of 315 Spanish children aged 5 to 12 years. Thirty-seven teachers from eleven schools completed the SAS-TR and the Strengths and Difficulties Questionnaire (SDQ) for each child. Confirmatory factor analysis supported the original two-factor structure, but a better fit model was obtained after removing four items. The scale was found to have high internal consistency (α = 0.91) and satisfactory test-retest reliability (ICC = 0.87) for the Spanish sample. Convergent validity was supported by positive significant correlations between the SAS-TR and the Emotional Symptoms subscale of the SDQ. Lower correlations between the SAS-TR and the SDQ Conduct Problems subscale supported the divergent validity. Overall, the findings suggest that the Spanish version of the SAS-TR is a reliable and valid instrument for teachers to assess anxiety in Spanish children.

  12. 基于SAS/IntrNet的预测系统实现%Implementation of Forecasting System Based on SAS/IntrNet

    Institute of Scientific and Technical Information of China (English)

    谢红

    2008-01-01

    SAS是一个使用广泛的大型模块化的应用软件系统,具有强大的数据分析和管理能力.文章以预测系统的实现为例,介绍如何使用SAS/IntrNet组件,实现SAS和J2EEWEB技术的结合.

  13. The SAS-5 N-terminal domain is a tetramer, with implications for centriole assembly in C. elegans.

    Science.gov (United States)

    Shimanovskaya, Ekaterina; Qiao, Renping; Lesigang, Johannes; Dong, Gang

    2013-07-01

    The centriole is a conserved microtubule-based organelle essential for both centrosome formation and cilium biogenesis. It has a unique 9-fold symmetry and its assembly is governed by at least five component proteins (SPD-2, ZYG-1, SAS-5, SAS-6 and SAS-4), which are recruited in a hierarchical order. Recently published structural studies of the SAS-6 N-terminal domain have greatly advanced our understanding of the mechanisms of centriole assembly. However, it remains unclear how the weak interaction between the SAS-6 N-terminal head groups could drive the assembly of a closed ring-like structure, and what determines the stacking of multiple rings on top one another in centriole duplication. We recently reported that SAS-5 binds specifically to a very narrow region of the SAS-6 central coiled coil through its C-terminal domain (CTD, residues 391-404). Here, we further demonstrate by both static light scattering and small angle X-ray scattering that the SAS-5 N-terminal domain (NTD, residues 1-260) forms a tetramer. Specifically, we found that the tetramer is formed by SAS-5 residues 82-260, whereas residues 1-81 are intrinsically disordered. Taking these results together, we propose a working model for SAS-5-mediated assembly of the multi-layered central tube structure.

  14. The damping of seismic waves and its determination from reflection seismograms

    Science.gov (United States)

    Engelhard, L.

    1979-01-01

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

  15. Quantitative Seismic Amplitude Analysis

    NARCIS (Netherlands)

    Dey, A.K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes.

  16. Quantitative Seismic Amplitude Analysis

    NARCIS (Netherlands)

    Dey, A.K.

    2011-01-01

    The Seismic Value Chain quantifies the cyclic interaction between seismic acquisition, imaging and reservoir characterization. Modern seismic innovation to address the global imbalance in hydrocarbon supply and demand requires such cyclic interaction of both feed-forward and feed-back processes. Cur

  17. Robotization in Seismic Acquisition

    NARCIS (Netherlands)

    Blacquière, G.; Berkhout, A.J.

    2013-01-01

    The amount of sources and detectors in the seismic method follows "Moore’s Law of seismic data acquisition", i.e., it increases approximately by a factor of 10 every 10 years. Therefore automation is unavoidable, leading to robotization of seismic data acquisition. Recently, we introduced a new

  18. Smoothing point data into maps using SAS/GRAPH (trade name) software. Forest Service research note

    Energy Technology Data Exchange (ETDEWEB)

    Chojnacky, D.C.; Rubey, M.E.

    1996-01-01

    Point of plot data are commonly available for mapping forest landscapes. Because such data are sampled, mapping a complete coverage usually requires some type of interpolation between plots. SAS/GRAPH software includes the G3GRID procedure for interpolating or smoothing this type of data to map with G3D or GCONTOUR procedures. However, the smoothing process in G3GRID is not easily controlled, nor can it be used to display missing data within rectangular grid maps. These shortcomings motivated development of SAS code that prepares point data for display in mapping units. This code links well with the rest of the SAS system to allow for powerful, easily controlled data analysis within mapping units. Examples are given for mapping forest vegetation with the GMAP procedure.

  19. The Artful Use of SAS/OR Software for Solving Integer Linear Programming with Many Solutions%巧用SAS/OR软件求解多解整数线性规划

    Institute of Scientific and Technical Information of China (English)

    邹祥福

    2004-01-01

    通过实例讲解如何巧用SAS/OR软件求解多解整数线性规划问题的多个解,弥补了用SAS/OR软件仅能得出多解整数线性规划一个解的缺点,使SAS/OR软件有了更广阔的应用.

  20. Comparing fibre channel, serial attached SCSI (SAS) and serial ATA (SATA)

    OpenAIRE

    Lam, Hin Wing Allen

    2009-01-01

    Serial Attached SCSI (SAS), Serial ATA (SATA) and Fibre Channel (FC) are the main storage interconnect technologies at present. FC is the main interconnect in Storage Area Network (SAN) with a well-known high performance and strong foundation of SCSI. SATA is the most cost-effective and high capacity in the hard drive market. On the other hand, SAS is just picking-up the momentum in both storage and hard drive areas and positions itself as a potential player. All three of these technologies h...

  1. Univariate and multivariate general linear models theory and applications with SAS

    CERN Document Server

    Kim, Kevin

    2006-01-01

    Reviewing the theory of the general linear model (GLM) using a general framework, Univariate and Multivariate General Linear Models: Theory and Applications with SAS, Second Edition presents analyses of simple and complex models, both univariate and multivariate, that employ data sets from a variety of disciplines, such as the social and behavioral sciences.With revised examples that include options available using SAS 9.0, this expanded edition divides theory from applications within each chapter. Following an overview of the GLM, the book introduces unrestricted GLMs to analyze multiple regr

  2. Median and quantile tests under complex survey design using SAS and R.

    Science.gov (United States)

    Pan, Yi; Caudill, Samuel P; Li, Ruosha; Caldwell, Kathleen L

    2014-11-01

    Techniques for conducting hypothesis testing on the median and other quantiles of two or more subgroups under complex survey design are limited. In this paper, we introduce programs in both SAS and R to perform such a test. A detailed illustration of the computations, macro variable definitions, input and output for the SAS and R programs are also included in the text. Urinary iodine data from National Health and Nutrition Examination Survey (NHANES) are used as examples for comparing medians between females and males as well as comparing the 75th percentiles among three salt consumption groups.

  3. A SAS-macro for estimation of the cumulative incidence using Poisson regression

    DEFF Research Database (Denmark)

    Waltoft, Berit Lindum

    2009-01-01

    the hazard rates, and the hazard rates are often estimated by the Cox regression. This procedure may not be suitable for large studies due to limited computer resources. Instead one uses Poisson regression, which approximates the Cox regression. Rosthøj et al. presented a SAS-macro for the estimation...... of the cumulative incidences based on the Cox regression. I present the functional form of the probabilities and variances when using piecewise constant hazard rates and a SAS-macro for the estimation using Poisson regression. The use of the macro is demonstrated through examples and compared to the macro presented...

  4. Testing the Short and Screener versions of the Social Adjustment Scale-Self-report (SAS-SR).

    Science.gov (United States)

    Gameroff, Marc J; Wickramaratne, Priya; Weissman, Myrna M

    2012-03-01

    The 54-item Social Adjustment Scale-Self-report (SAS-SR) is a measure of social functioning used in research studies and clinical practice. Two shortened versions were recently developed: the 24-item SAS-SR: Short and the 14-item SAS-SR: Screener. We briefly describe the development of the shortened scales and then assess their reliability and validity in comparison to the full SAS-SR in new analyses from two separate samples of convenience from a family study and from a primary care clinic. Compared to the full SAS-SR, the shortened scales performed well, exhibiting high correlations with full SAS-SR scores (r values between 0.81 and 0.95); significant correlations with health-related quality of life as measured by the Short Form 36 Health Survey; the ability to distinguish subjects with major depression versus other psychiatric disorders versus no mental disorders; and sensitivity to change in clinical status as measured longitudinally with the Symptom Checklist-90 and Global Assessment Scale. The SAS-SR: Short and SAS-SR: Screener retained the areas assessed by the full SAS-SR with fewer items in each area, and appear to be promising replacements for the full scale when a shorter administration time is desired and detailed information on performance in different areas is not required. Further work is needed to test the validity of the shortened measures.

  5. SAS-4 Protein in Trypanosoma brucei Controls Life Cycle Transitions by Modulating the Length of the Flagellum Attachment Zone Filament.

    Science.gov (United States)

    Hu, Huiqing; Zhou, Qing; Li, Ziyin

    2015-12-18

    The evolutionarily conserved centriole/basal body protein SAS-4 regulates centriole duplication in metazoa and basal body duplication in flagellated and ciliated organisms. Here, we report that the SAS-4 homolog in the flagellated protozoan Trypanosoma brucei, TbSAS-4, plays an unusual role in controlling life cycle transitions by regulating the length of the flagellum attachment zone (FAZ) filament, a specialized cytoskeletal structure required for flagellum adhesion and cell morphogenesis. TbSAS-4 is concentrated at the distal tip of the FAZ filament, and depletion of TbSAS-4 in the trypomastigote form disrupts the elongation of the new FAZ filament, generating cells with a shorter FAZ associated with a longer unattached flagellum and repositioned kinetoplast and basal body, reminiscent of epimastigote-like morphology. Further, we show that TbSAS-4 associates with six additional FAZ tip proteins, and depletion of TbSAS-4 disrupts the enrichment of these FAZ tip proteins at the new FAZ tip, suggesting a role of TbSAS-4 in maintaining the integrity of this FAZ tip protein complex. Together, these results uncover a novel function of TbSAS-4 in regulating the length of the FAZ filament to control basal body positioning and life cycle transitions in T. brucei.

  6. The Centriole Cartwheel Protein SAS-6 in Trypanosoma brucei Is Required for Probasal Body Biogenesis and Flagellum Assembly.

    Science.gov (United States)

    Hu, Huiqing; Liu, Yi; Zhou, Qing; Siegel, Sara; Li, Ziyin

    2015-09-01

    The centriole in eukaryotes functions as the cell's microtubule-organizing center (MTOC) to nucleate spindle assembly, and its biogenesis requires an evolutionarily conserved protein, SAS-6, which assembles the centriole cartwheel. Trypanosoma brucei, an early branching protozoan, possesses the basal body as its MTOC to nucleate flagellum biogenesis. However, little is known about the components of the basal body and their roles in basal body biogenesis and flagellum assembly. Here, we report that the T. brucei SAS-6 homolog, TbSAS-6, is localized to the mature basal body and the probasal body throughout the cell cycle. RNA interference (RNAi) of TbSAS-6 inhibited probasal body biogenesis, compromised flagellum assembly, and caused cytokinesis arrest. Surprisingly, overexpression of TbSAS-6 in T. brucei also impaired probasal body duplication and flagellum assembly, contrary to SAS-6 overexpression in humans, which produces supernumerary centrioles. Furthermore, we showed that depletion of T. brucei Polo-like kinase, TbPLK, or inhibition of TbPLK activity did not abolish TbSAS-6 localization to the basal body, in contrast to the essential role of Polo-like kinase in recruiting SAS-6 to centrioles in animals. Altogether, these results identified the essential role of TbSAS-6 in probasal body biogenesis and flagellum assembly and suggest the presence of a TbPLK-independent pathway governing basal body duplication in T. brucei.

  7. The Seismic Alert System of Mexico (SASMEX): Performance and Evolution

    Science.gov (United States)

    Espinosa Aranda, J.

    2013-05-01

    Originally the Seismic Alert System of Mexico (SASMEX) was proposed to integrate the Seismic Alert System of Mexico City (SAS), operating since 1991, with the Seismic Alert System of Oaxaca City (SASO), in services since 2003. And today, after the intense big earthquake activity observed in our world during 2010 and 2011, local governments of Mexico City, Oaxaca Estate, and the Mexican Ministry of the Interior have been promoting the expansion of this technological EEW development. Until 2012 SASMEX better coverage includes 48 new field seismic sensors (FS) deployed over the seismic region of Jalisco, Colima, Michoacan and Puebla, with someone enhancements over Guerrero and Oaxaca, to reach 97 FS. During 2013, 35 new FS has been proposed to SASMEX enhancements covering the Chiapas and Veracruz seismic regions. The SASMEX, with the support of the Mexico Valley Broadcasters Association (ARVM) since 1993, automatically issue Public and Preventive earthquake early warning signals in the Cities of Mexico, Toluca, Acapulco, Chilpancingo, and Oaxaca. The seismic warning range in each case is seated in accordance with local Civil Protection Authorities: Public Alert, if they expect strong earthquake effects, and Preventive Alert one, the effect could be moderated. Now the SASMEX warning time opportunity could be different to the 60 sec. average typically generated when SAS warned earthquake effects coming from Guerrero to Mexico City valley. Mexican EEW issued today reach: 16 Public and 62 Preventive Alert in Mexico City; 25 Public and 19 Preventive Alerts in Oaxaca City; also 14 Public and 4 Preventive Alerts in Acapulco; 14 Public and 5 Preventive Alerts in Chilpancingo. The earthquakes events registered by SASMEX FS until now reach 3448. With the support of private and Federal telecommunications infrastructure like, TELMEX, Federal Electric Commission, and the Mexican Security Ministry, it was developed a redundant communication system with pads to link the different

  8. Lg Attenuation Characteristic of Gujarat Region (Western India)

    Science.gov (United States)

    Jaiswal, Namrata; Singh, Chandrani

    2016-04-01

    We estimate the Lg attenuation characteristics of the Gujarat Region in Western India by using a reliable two-station method. This region comes under the V, IV and III seismicity zone. So, in India this is the seismic active region other than Himalayas, which shows high seismicity. Lg is typically the most prominent short-period seismic phase on high frequency seismogram observed over the continental paths from regional to teleseimic distance. We use data from 15 earthquakes with magnitude > 5 mb and focal depth Lg Q (Q0) values between many pairs of stations. Finally, 5 events with 70 high-quality inter-station paths were selected from 117 possible pairs of stations that are (1) aligned approximately with the source and (2) separated enough to permit the use of the standard two-station method for Lg Q measurement. Spatial variations in Q0 have been noticed across the Gujarat region. Low Q0 ( 300) value. These observations are consistent with the results of the body wave attenuation structure reported for the region. The variations in the attenuation characteristics may be caused due to both the intrinsic and scattering contributions caused by thermal effects, sedimentary layer thickness as well as heterogeneities present below the study region. Our results are found to be comparable with the previous studies of the attenuation characteristics of the Gujarat region.

  9. SAS võib omapoolse panusena kustutada osa Estonian Airi laenust / Gert D. Hankewitz

    Index Scriptorium Estoniae

    Hankewitz, Gert D.

    2011-01-01

    Lennufirma SAS investorsuhete asepresidendi Sture Stoleni sõnul ei ole tõenäoline, et nende firma maksaks mingit raha Estonian Airi kapitali, küll aga ei saa välistada võimalust, et võidakse kustutada osa antud laenust

  10. Essentials of Excel, Excel VBA, SAS and Minitab for statistical and financial analyses

    CERN Document Server

    Lee, Cheng-Few; Chang, Jow-Ran; Tai, Tzu

    2016-01-01

    This introductory textbook for business statistics teaches statistical analysis and research methods via business case studies and financial data using Excel, MINITAB, and SAS. Every chapter in this textbook engages the reader with data of individual stock, stock indices, options, and futures. One studies and uses statistics to learn how to study, analyze, and understand a data set of particular interest. Some of the more popular statistical programs that have been developed to use statistical and computational methods to analyze data sets are SAS, SPSS, and MINITAB. Of those, we look at MINITAB and SAS in this textbook. One of the main reasons to use MINITAB is that it is the easiest to use among the popular statistical programs. We look at SAS because it is the leading statistical package used in industry. We also utilize the much less costly and ubiquitous Microsoft Excel to do statistical analysis, as the benefits of Excel have become widely recognized in the academic world and its analytical capabilities...

  11. A new SAS program for behavioral analysis of Electrical Penetration Graph (EPG) data

    Science.gov (United States)

    A new program is introduced that uses SAS software to duplicate output of descriptive statistics from the Sarria Excel workbook for EPG waveform analysis. Not only are publishable means and standard errors or deviations output, the user also is guided through four relatively simple sub-programs for ...

  12. Measuring Statistics Anxiety: Cross-Country Validity of the Statistical Anxiety Scale (SAS)

    Science.gov (United States)

    Chiesi, Francesca; Primi, Caterina; Carmona, Jose

    2011-01-01

    The aim of the research was to test the psychometric properties of the Italian version of the Vigil-Colet et al.'s Statistical Anxiety Scale (SAS), taking into account evidences based on (a) internal structure (factorial structure and cross-country invariance) and (b) relationships to other variables (the statistics anxiety's nomological network).…

  13. Kuue riigi tudengid mängivad Radisson SAS hotelli juhatust / Agne Narusk

    Index Scriptorium Estoniae

    Narusk, Agne

    2003-01-01

    90 soome, eesti, ungari, prantsusmaa, hollandi ja belgia tudengit kehastuvad Radisson SAS hotellide rahvusvahelise juhatuse liikmeteks ja esitavad kujuteldavale aktsionäride üldkoosolekule nägemuse uutest võimalikest hotellidest. Hotelliülesanded koostas Eesti Kõrgema Kommertskooli (EBS) ettevõtluse õppetooli lektor Elena Pruvli

  14. SAS pani Estonian Airi aktsiad müüki / Riina Kallas, Tuuli Aug

    Index Scriptorium Estoniae

    Kallas, Riina

    2009-01-01

    SAS müüb enamusosaluse Estonian Airis ja veel kuues tütarfirmas, majandus- ja kommunikatsiooniminister Juhan Parts näeb Estonian Airi uue osanikuna mõnda Eesti investorit. Endise Estonian Airi presidendi Erki Urva arvamus

  15. SAS-2 high-energy gamma-ray observations of the Vela pulsar. II

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Ogelman, H. B.

    1977-01-01

    Analysis of additional data from SAS-2 experiment and improvements in the orbit-attitude data and analysis procedures have produced revised values for the flux from the Vela gamma-ray source. The pulsar phase plot shows two peaks, neither of which is in phase with the single radio pulse.

  16. Numerical support of laboratory experiments: Attenuation and velocity estimations

    Science.gov (United States)

    Saenger, Erik; Madonna, Claudio; Frehner, Marcel; Almqvist, Bjarne

    2014-02-01

    We show that numerical support of laboratory experiments can significantly increase the understanding and simplify the interpretation of the obtained laboratory results. First we perform simulations of the Seismic Wave Attenuation Module to measure seismic attenuation of reservoir rocks. Our findings confirm the accuracy of this system. However, precision can be further improved by optimizing the sensor positions. Second, we model wave propagation for an ultrasonic pulse transmission experiment used to determine pressure- and temperature-dependent seismic velocities in the rock. Multiple waves are identified in our computer experiment, including bar waves. The metal jacket that houses the sample assembly needs to be taken into account for a proper estimation of the ultrasonic velocities. This influence is frequency-dependent.

  17. Error bars for the global seismic Q profile

    NARCIS (Netherlands)

    Resovsky, Joseph; Trampert, Jeannot; Hilst, R.D. van der

    2006-01-01

    The radial attenuation profile of the Earth is needed to account for dispersion effects when interpreting seismic velocities and can provide important constraints on composition. To date, most radial Q models have been produced using traditional damped inversions of free oscillation and surface wave

  18. Angola Seismicity MAP

    Science.gov (United States)

    Neto, F. A. P.; Franca, G.

    2014-12-01

    The purpose of this job was to study and document the Angola natural seismicity, establishment of the first database seismic data to facilitate consultation and search for information on seismic activity in the country. The study was conducted based on query reports produced by National Institute of Meteorology and Geophysics (INAMET) 1968 to 2014 with emphasis to the work presented by Moreira (1968), that defined six seismogenic zones from macro seismic data, with highlighting is Zone of Sá da Bandeira (Lubango)-Chibemba-Oncócua-Iona. This is the most important of Angola seismic zone, covering the epicentral Quihita and Iona regions, geologically characterized by transcontinental structure tectono-magmatic activation of the Mesozoic with the installation of a wide variety of intrusive rocks of ultrabasic-alkaline composition, basic and alkaline, kimberlites and carbonatites, strongly marked by intense tectonism, presenting with several faults and fractures (locally called corredor de Lucapa). The earthquake of May 9, 1948 reached intensity VI on the Mercalli-Sieberg scale (MCS) in the locality of Quihita, and seismic active of Iona January 15, 1964, the main shock hit the grade VI-VII. Although not having significant seismicity rate can not be neglected, the other five zone are: Cassongue-Ganda-Massano de Amorim; Lola-Quilengues-Caluquembe; Gago Coutinho-zone; Cuima-Cachingues-Cambândua; The Upper Zambezi zone. We also analyzed technical reports on the seismicity of the middle Kwanza produced by Hidroproekt (GAMEK) region as well as international seismic bulletins of the International Seismological Centre (ISC), United States Geological Survey (USGS), and these data served for instrumental location of the epicenters. All compiled information made possible the creation of the First datbase of seismic data for Angola, preparing the map of seismicity with the reconfirmation of the main seismic zones defined by Moreira (1968) and the identification of a new seismic

  19. Clinical SAS programming in India: A study of industry needs versus wants

    Directory of Open Access Journals (Sweden)

    Nithiyanandhan Ananthakrishnan

    2014-01-01

    Full Text Available Background: The clinical SAS (www.sas.com programming industry, in India, has seen a rapid growth in the last decade and the trend seems set to continue, for the next couple of years, due to cost advantage and the availability of skilled labor. On one side the industry needs are focused on less execution time, high margins, segmented tasks and the delivery of high quality output with minimal oversight. On the other side, due to the increased demand for skilled resources, the wants of the programmers have taken a different shift toward diversifying exposure, unsustainable wage inflation due to multiple opportunities and generally high expectations around career progression. If the industry needs are not going to match with programmers want, or vice versa, then there is the possibility that the current year on year growth may start to slow or even go into decline. Aim: This paper is intended to identify the gap between wants and need and puts forwards some suggestions, for both sides, in ways to change the equation to benefit all. Settings and Design: Questionnaire on similar themes created to survey managers and programmers working in clinical SAS programming industry and was surveyed online to collect their perspectives. Their views are compared for each theme and presented as results. Materials and Methods: Two surveys were created in www.surveymonkey.com. Management: https://www.surveymonkey.com/s/SAS_India_managment_needvswant_survey. Programmer: https://www.surveymonkey.com/s/SAS_India_programmer_needvswant_survey. Statistical Analysis Used: Bar chart and pie chart used on data collect to show segmentation of data. Results and Conclusions: In conclusion, it seeks to highlight the future industry direction and the skillset that existing programmers need to have, in order to sustain the momentum and remain competitive, to contribute to the future pipeline and the development of the profession in India.

  20. The SAS4A/SASSYS-1 Safety Analysis Code System, Version 5

    Energy Technology Data Exchange (ETDEWEB)

    Fanning, T. H. [Argonne National Lab. (ANL), Argonne, IL (United States); Brunett, A. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Sumner, T. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-01

    The SAS4A/SASSYS-1 computer code is developed by Argonne National Laboratory for thermal, hydraulic, and neutronic analysis of power and flow transients in liquidmetal- cooled nuclear reactors (LMRs). SAS4A was developed to analyze severe core disruption accidents with coolant boiling and fuel melting and relocation, initiated by a very low probability coincidence of an accident precursor and failure of one or more safety systems. SASSYS-1, originally developed to address loss-of-decay-heat-removal accidents, has evolved into a tool for margin assessment in design basis accident (DBA) analysis and for consequence assessment in beyond-design-basis accident (BDBA) analysis. SAS4A contains detailed, mechanistic models of transient thermal, hydraulic, neutronic, and mechanical phenomena to describe the response of the reactor core, its coolant, fuel elements, and structural members to accident conditions. The core channel models in SAS4A provide the capability to analyze the initial phase of core disruptive accidents, through coolant heat-up and boiling, fuel element failure, and fuel melting and relocation. Originally developed to analyze oxide fuel clad with stainless steel, the models in SAS4A have been extended and specialized to metallic fuel with advanced alloy cladding. SASSYS-1 provides the capability to perform a detailed thermal/hydraulic simulation of the primary and secondary sodium coolant circuits and the balance-ofplant steam/water circuit. These sodium and steam circuit models include component models for heat exchangers, pumps, valves, turbines, and condensers, and thermal/hydraulic models of pipes and plena. SASSYS-1 also contains a plant protection and control system modeling capability, which provides digital representations of reactor, pump, and valve controllers and their response to input signal changes.

  1. Improving Seismic Image with Advanced Processing Techniques

    Directory of Open Access Journals (Sweden)

    Mericy Lastra Cunill

    2012-07-01

    Full Text Available Taking Taking into account the need to improve the seismic image in the central area of Cuba, specifically in the area of the Venegas sector, located in the Cuban Folded Belt, the seismic data acquired by Cuba Petróleo (CUPET in the year 2007 was reprocessed according to the experience accumulated during the previous processing carried out in the same year, and the new geologic knowledge on the area. This was done with the objective of improving the results. The processing applied previously was analyzed by reprocessing the primary data with new focuses and procedures, among them are the following: the attenuation of the superficial wave with a filter in the Radon domain in its lineal variant, the change of the primary statics corrections of elevation by those of refraction, the study of velocity with the selection automatic biespectral of high density, the study of the anisotropy, the attenuation of the random noise, and the pre stack time and depth migration. As a result of this reprocessing, a structure that was not identified in the seismic sections of the previous processing was located at the top of a Continental Margin sediment located to the north of the sector that increased the potentialities of finding hydrocarbons in quantities of economic importance thus diminishing the risk of drilling in the sector Venegas.

  2. Attenuation tomography in the rupture area of the 2010 M8.8 Maule, Chile, earthquake

    Science.gov (United States)

    Heather-Smith, Helen; Rietbrock, Andreas

    2016-04-01

    In recent years several seismological studies have developed a detailed image of the megathrust interface between the subducting Nazca plate and and the overriding South American plate in the rupture area of the 2010 M8.8 Maule, Chile, earthquake. Hicks et al. (2014) have published a high resolution 3D seismic tomography model and characterised the different regimes acting along the interface based on their seismic properties. A more detailed study by Moreno et al. (2014) showed that the seismic Vp/Vs ratio and inter-seismic locking determined from GPS measurements are correlated. Together these observations open up the possibility to map the rupture potential of possible future earthquakes, although the underlying processes are yet not fully understood and a more in depth analysis of other physical properties is needed. 3D seismic attenuation structure as well as seismic stress-drop distribution based on the aftershock seismicity are providing independent data sets to better constrain the physical processes acting along the subduction zone interface. As seismic attenuation is particularly sensitive to fluid saturation it opens up the possibility to study more directly the influence of fluids on aftershock activity as compared to standard velocity tomography studies. Based on our event catalogue of approximately 30,000 aftershocks we are currently selecting the most appropriate data set for the staggered 3D attenuation tomography. The inverted attenuation model will then be used to calculate seismic stress drop values for the complete aftershock catalogue. We will present our preliminary 3D attenuation model together with our stress drop estimates and compare our finding to the 3D velocity structure and slip distribution.

  3. Coupling the System Analysis Module with SAS4A/SASSYS-1

    Energy Technology Data Exchange (ETDEWEB)

    Fanning, T. H. [Argonne National Lab. (ANL), Argonne, IL (United States); Hu, R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-30

    SAS4A/SASSYS-1 is a simulation tool used to perform deterministic analysis of anticipated events as well as design basis and beyond design basis accidents for advanced reactors, with an emphasis on sodium fast reactors. SAS4A/SASSYS-1 has been under development and in active use for nearly forty-five years, and is currently maintained by the U.S. Department of Energy under the Office of Advanced Reactor Technology. Although SAS4A/SASSYS-1 contains a very capable primary and intermediate system modeling component, PRIMAR-4, it also has some shortcomings: outdated data management and code structure makes extension of the PRIMAR-4 module somewhat difficult. The user input format for PRIMAR-4 also limits the number of volumes and segments that can be used to describe a given system. The System Analysis Module (SAM) is a fairly new code development effort being carried out under the U.S. DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. SAM is being developed with advanced physical models, numerical methods, and software engineering practices; however, it is currently somewhat limited in the system components and phenomena that can be represented. For example, component models for electromagnetic pumps and multi-layer stratified volumes have not yet been developed. Nor is there support for a balance of plant model. Similarly, system-level phenomena such as control-rod driveline expansion and vessel elongation are not represented. This report documents fiscal year 2016 work that was carried out to couple the transient safety analysis capabilities of SAS4A/SASSYS-1 with the system modeling capabilities of SAM under the joint support of the ART and NEAMS programs. The coupling effort was successful and is demonstrated by evaluating an unprotected loss of flow transient for the Advanced Burner Test Reactor (ABTR) design. There are differences between the stand-alone SAS4A/SASSYS-1 simulations and the coupled SAS/SAM simulations, but these are mainly

  4. Investigations concerning seismic response control of self-anchored suspension bridge with MR dampers

    Institute of Scientific and Technical Information of China (English)

    Menggang YANG; Zhengqing CHEN; Jianhua HU

    2008-01-01

    To mitigate the seismic response of selfanchored suspension bridges, equations of motion governing the coupled system of bridge- magneto-rheological (MR) dampers subject to seismic excitation are formulated by employing the phenomenological model of MR dampers. A corresponding computer program is developed and employed for studying the seismic response control of a self-anchored suspension bridge with a main span of 350 m. The effect of variable current and number of dampers on seismic response control is investigated. The numerical results indicate the longitudinal displacement of the tower top and bridge girder decrease with the increase in input current and number of MR dampers attached longitudinally at the tower-girder connections, and the internal forces of the tower are effectively attenuated as well. It appears that small electronic current (0.5 A in this study) may sufficiently attenuate the seismic responses for practical engineering applications.

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT-A AND A ENVIRONMENTAL SEALS, INC., SEAL ASSIST SYSTEM (SAS) PHASE II REPORT

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of Seal Assist System (SAS) for natural gas reciprocating compressor rod packing manufactured by A&A Environmental Seals, Inc. The SAS uses a secondary containment gland to collect natural g...

  6. Houston, We Have a Problem: Teachers Find No Value in the SAS Education Value-Added Assessment System (EVAAS®)

    Science.gov (United States)

    Collins, Clarin

    2014-01-01

    This study examined the SAS Education Value-Added Assessment System (EVAAS®) in practice, as perceived and experienced by teachers in the Southwest School District (SSD). To evaluate teacher effectiveness, SSD is using SAS EVAAS® for high-stakes consequences more than any other district or state in the country. A mixed-method design including a…

  7. Simplified seismic risk analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pellissetti, Manuel; Klapp, Ulrich [AREVA NP GmbH, Erlangen (Germany)

    2011-07-01

    Within the context of probabilistic safety analysis (PSA) for nuclear power plants (NPP's), seismic risk assessment has the purpose to demonstrate that the contribution of seismic events to overall risk is not excessive. The most suitable vehicle for seismic risk assessment is a full scope seismic PSA (SPSA), in which the frequency of core damage due to seismic events is estimated. An alternative method is represented by seismic margin assessment (SMA), which aims at showing sufficient margin between the site-specific safe shutdown earthquake (SSE) and the actual capacity of the plant. Both methods are based on system analysis (fault-trees and event-trees) and hence require fragility estimates for safety relevant systems, structures and components (SSC's). If the seismic conditions at a specific site of a plant are not very demanding, then it is reasonable to expect that the risk due to seismic events is low. In such cases, the cost-benefit ratio for performing a full scale, site-specific SPSA or SMA will be excessive, considering the ultimate objective of seismic risk analysis. Rather, it will be more rational to rely on a less comprehensive analysis, used as a basis for demonstrating that the risk due to seismic events is not excessive. The present paper addresses such a simplified approach to seismic risk assessment which is used in AREVA to: - estimate seismic risk in early design stages, - identify needs to extend the design basis, - define a reasonable level of seismic risk analysis Starting from a conservative estimate of the overall plant capacity, in terms of the HCLPF (High Confidence of Low Probability of Failure), and utilizing a generic value for the variability, the seismic risk is estimated by convolution of the hazard and the fragility curve. Critical importance is attached to the selection of the plant capacity in terms of the HCLPF, without performing extensive fragility calculations of seismically relevant SSC's. A suitable basis

  8. Attenuation tomography in West Bohemia/Vogtland

    Science.gov (United States)

    Mousavi, Sima; Haberland, Christian; Bauer, Klaus; Hejrani, Babak; Korn, Michael

    2017-01-01

    We present a three-dimensional (3-D) P-wave attenuation (Qp) model for the geodynamically active swarm earthquake area of West Bohemia/Vogtland in the Czech/German border region. Path-averaged attenuation t* is calculated from amplitude spectra of time windows around the P-wave arrivals of local earthquakes. Average t/t* value or Qp for stations close to Nový Kostel are very low (focal zone (increases up to 500 within 80 km distance). The SIMUL2000 tomography scheme is used to invert the t* for P-wave attenuation perturbation. Analysis of resolution shows that our model is well-resolved in the vicinity of earthquake swarm hypocenters. The prominent features of the model are located around Nový Kostel focal zone and its northern vicinity. Beneath Nový Kostel a vertically stretched (down to depth of 11 km) and a highly attenuating body is observed. We believe that this is due to fracturing and high density of cracks inside the weak earthquake swarm zone in conjunction with presence of free gas/fluid. Further north of Nový Kostel two highly attenuating bodies are imaged which could represent fluid channels toward the surface. The eastern anomaly shows a good correlation with the fluid accumulation area which was suggested in 9HR seismic profile.

  9. Probabilistic Seismic Hazard Assessment of Babol, Iran

    Directory of Open Access Journals (Sweden)

    Gholamreza Abdollahzadeh

    2011-01-01

    Full Text Available This paper presents a probabilistic seismic hazard assessment of Babol, one of big cities in north of Iran. Many destructive earthquakes happened in Iran in the last centuries. It comes from historical references that at least many times; Babol has been destroyed by catastrophic earthquakes. In this paper, the peak horizontal ground acceleration over the bedrock (PGA is calculated by a probabilistic seismic hazard assessment (PSHA. For this reason, at first, a collected catalogue, containing both historical and instrumental events that occurred in a radius of 200 km of Babol city and covering the period from 874 to 2004 have been gathered. Then, seismic sources are modeled and recur¬rence relationship is established. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters (SP by Kijko method. The calculations were performed using the logic tree method and four weighted attenuation relationships Ghodrati, 0.35, Khademi, 0.25, Ambraseys and Simpson, 0.2, and Sarma and Srbulov, 0.2. Seismic hazard assessment is then carried out for 8 horizontal by 7 vertical lines grid points using SEISRISK III. Finally, two seismic hazard maps of the studied area based on Peak Horizontal Ground Acceleration (PGA over bedrock for 2 and 10% probability of ex¬ceedance in one life cycles of 50 year are presented. These calculations have been performed by the Poisson distribution of two hazard levels. The results showed that the PGA ranges from 0.32 to 0.33 g for a return period of 475 years and from 0.507 to 0.527 g for a return period of 2475 years. Since population is very dense in Babol and vulnerability of buildings is high, the risk of future earthquakes will be very significant.

  10. Unsteady Simulations of the Flow in a Channel Flow and a Ventilated Room Using the SST-SAS Model

    DEFF Research Database (Denmark)

    Davidson, Lars; Nielsen, Peter V.

    -SAS model is evaluated for two flows: developing channel flow and the flow in a three-dimensional ventilated room. Unsteady inlet boundary conditions are prescribed in both cases by superimposing isotropic synthetic fluctuations on a steady inlet boundary velocity profile.......The SAS model (Scale Adapted Simulation) was invented by Menter and his co-workers. The idea behind the SST-SAS model is to add an additional production term - the SAS term - in the w equation which is sensitive to resolved (i.e. unsteady) fluctuations. In regions where the flow is on the limit...... of going unsteady, the object of the SAS term is to increase w. The result is that k and vt are reduced so that the dissipating (damping) effect of the turbulent viscosity on the resolved fluctuations is reduced, thereby promoting the momentum equations to switch from steady to unsteady mode. The SST...

  11. SAS macro programs for geographically weighted generalized linear modeling with spatial point data: applications to health research.

    Science.gov (United States)

    Chen, Vivian Yi-Ju; Yang, Tse-Chuan

    2012-08-01

    An increasing interest in exploring spatial non-stationarity has generated several specialized analytic software programs; however, few of these programs can be integrated natively into a well-developed statistical environment such as SAS. We not only developed a set of SAS macro programs to fill this gap, but also expanded the geographically weighted generalized linear modeling (GWGLM) by integrating the strengths of SAS into the GWGLM framework. Three features distinguish our work. First, the macro programs of this study provide more kernel weighting functions than the existing programs. Second, with our codes the users are able to better specify the bandwidth selection process compared to the capabilities of existing programs. Third, the development of the macro programs is fully embedded in the SAS environment, providing great potential for future exploration of complicated spatially varying coefficient models in other disciplines. We provided three empirical examples to illustrate the use of the SAS macro programs and demonstrated the advantages explained above.

  12. Caenorhabditis elegans centriolar protein SAS-6 forms a spiral that is consistent with imparting a ninefold symmetry.

    Science.gov (United States)

    Hilbert, Manuel; Erat, Michèle C; Hachet, Virginie; Guichard, Paul; Blank, Iris D; Flückiger, Isabelle; Slater, Leanne; Lowe, Edward D; Hatzopoulos, Georgios N; Steinmetz, Michel O; Gönczy, Pierre; Vakonakis, Ioannis

    2013-07-09

    Centrioles are evolutionary conserved organelles that give rise to cilia and flagella as well as centrosomes. Centrioles display a characteristic ninefold symmetry imposed by the spindle assembly abnormal protein 6 (SAS-6) family. SAS-6 from Chlamydomonas reinhardtii and Danio rerio was shown to form ninefold symmetric, ring-shaped oligomers in vitro that were similar to the cartwheels observed in vivo during early steps of centriole assembly in most species. Here, we report crystallographic and EM analyses showing that, instead, Caenorhabotis elegans SAS-6 self-assembles into a spiral arrangement. Remarkably, we find that this spiral arrangement is also consistent with ninefold symmetry, suggesting that two distinct SAS-6 oligomerization architectures can direct the same output symmetry. Sequence analysis suggests that SAS-6 spirals are restricted to specific nematodes. This oligomeric arrangement may provide a structural basis for the presence of a central tube instead of a cartwheel during centriole assembly in these species.

  13. Seismic methods for resource exploration in enhanced geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, Roland; Majer, Ernest L.

    2002-06-12

    A finite-difference modeling study of seismic wave propagation was conducted to determine how to best investigate subsurface faults and fracture zones in geothermal areas. The numerical model was created based on results from a previous seismic reflection experiment. A suite of fault models was investigated including blind faults and faults with surface expressions. The seismic data suggest that blind faults can be detected by a sudden attenuation of seismic wave amplitudes, as long the fault is located below the receiver array. Additionally, a conversion from P- to S-waves indicates the reflection and refraction of the P-waves while propagating across the fault. The drop in amplitudes and the excitation of S-waves can be used to estimate the location of the fault at depth. The accuracy of the numerical modeling depends on the availability of a priori in situ information (velocity and density) from borehole experiments in the geothermal area.

  14. Probabilistic seismic hazard maps for the North Balkan region

    Directory of Open Access Journals (Sweden)

    R. M. W. Musson

    1999-06-01

    Full Text Available A set of seismic hazard maps, expressed as horizontal peak ground acceleration, have been computed for a large area of Central and Eastern Europe covering the North Balkan area (Former Yugoslavia, Hungary, Romania. These are based on: a a compound earthquake catalogue for the region; b a seismic source model of 50 zones compiled on the basis of tectonic divisions and seismicity, and c a probabilistic methodology using stochastic (Monte Carlo modelling. It is found that the highest hazard in the region comes from intermediate focus earthquakes occurring in the Vrancea seismic zone; here the hazard exceeds 0.4 g at return periods of 475 years. Special account has been taken of the directional nature of attenuation from this source.

  15. Photonic Crystal Fiber Attenuator

    Institute of Scientific and Technical Information of China (English)

    Joo; Beom; Eom; Hokyung; Kim; Jinchae; Kim; Un-Chul; Paek; Byeong; Ha; Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  16. Seismic Catalogue and Seismic Network in Haiti

    Science.gov (United States)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.

    2013-05-01

    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  17. Deep Mantle Seismic Modeling and Imaging

    Science.gov (United States)

    Lay, Thorne; Garnero, Edward J.

    2011-05-01

    Detailed seismic modeling and imaging of Earth's deep interior is providing key information about lower-mantle structures and processes, including heat flow across the core-mantle boundary, the configuration of mantle upwellings and downwellings, phase equilibria and transport properties of deep mantle materials, and mechanisms of core-mantle coupling. Multichannel seismic wave analysis methods that provide the highest-resolution deep mantle structural information include network waveform modeling and stacking, array processing, and 3D migrations of P- and S-wave seismograms. These methods detect and identify weak signals from structures that cannot be resolved by global seismic tomography. Some methods are adapted from oil exploration seismology, but all are constrained by the source and receiver distributions, long travel paths, and strong attenuation experienced by seismic waves that penetrate to the deep mantle. Large- and small-scale structures, with velocity variations ranging from a fraction of a percent to tens of percent, have been detected and are guiding geophysicists to new perspectives of thermochemical mantle convection and evolution.

  18. Aerosol Optical Depth Value-Added Product for the SAS-He Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Ermold, B [Pacific Northwest National Laboratory; Flynn, CJ [Pacific Northwest National Laboratory; Barnard, J [University of Nevada Reno

    2013-11-27

    The Shortwave Array Spectroradiometer – Hemispheric (SAS-He) is a ground-based, shadowband instrument that measures the direct and diffuse solar irradiance. In this regard, the instrument is similar to the Multi-Filter Rotating Shadowband Radiometer (MFRSR) – an instrument that has been in the ARM suite of instruments for more than 15 years. However, the two instruments differ significantly in wavelength resolution and range. In particular, the MFRSR only observes the spectrum in six discrete wavelength channels of about 10 nm width from 415 to 940 nm. The SAS-He, in contrast, incorporates two fiber-coupled grating spectrometers: a Si CCD spectrometer with over 2000 pixels covering the range from 325-1040 nm with ~ 2.5 nm resolution ,and an InGaAs array spectrometer with 256 pixels covering the wavelength range from 960-1700 nm with ~ 6 nm resolution.

  19. SPSS and SAS programs for comparing Pearson correlations and OLS regression coefficients.

    Science.gov (United States)

    Weaver, Bruce; Wuensch, Karl L

    2013-09-01

    Several procedures that use summary data to test hypotheses about Pearson correlations and ordinary least squares regression coefficients have been described in various books and articles. To our knowledge, however, no single resource describes all of the most common tests. Furthermore, many of these tests have not yet been implemented in popular statistical software packages such as SPSS and SAS. In this article, we describe all of the most common tests and provide SPSS and SAS programs to perform them. When they are applicable, our code also computes 100 × (1 - α)% confidence intervals corresponding to the tests. For testing hypotheses about independent regression coefficients, we demonstrate one method that uses summary data and another that uses raw data (i.e., Potthoff analysis). When the raw data are available, the latter method is preferred, because use of summary data entails some loss of precision due to rounding.

  20. POWERLIB: SAS/IML Software for Computing Power in Multivariate Linear Models

    Directory of Open Access Journals (Sweden)

    Jacqueline L. Johnson

    2009-04-01

    Full Text Available The POWERLIB SAS/IML software provides convenient power calculations for a widerange of multivariate linear models with Gaussian errors. The software includes the Box,Geisser-Greenhouse, Huynh-Feldt, and uncorrected tests in the univariate" approach torepeated measures (UNIREP, the Hotelling Lawley Trace, Pillai-Bartlett Trace, andWilks Lambda tests in multivariate" approach (MULTIREP, as well as a limited butuseful range of mixed models. The familiar univariate linear model with Gaussian errorsis an important special case. For estimated covariance, the software provides condencelimits for the resulting estimated power. All power and condence limits values canbe output to a SAS dataset, which can be used to easily produce plots and tables formanuscripts.

  1. PREFACE Proceedings of the XIV International Conference on Small-Angle Scattering, SAS-2009

    Science.gov (United States)

    King, Stephen; Terrill, Nicholas

    2010-10-01

    The XIV International Conference on Small-Angle Scattering, SAS-2009, was held in Oxford UK, 13-18 September 2009, and was jointly organised under the auspices of the International Union of Crystallography Commission on SAS by a team from the Diamond Light Source and the ISIS Pulsed Neutron Source - their first such joint venture - with help from the UK Science and Technology Facilities Council. It was the first time that this long running and successful series of conferences on the application, science and technology of small-angle scattering techniques had been staged in the UK. The UK has a proud heritage in small-angle scattering: as home to one of the world's first SANS instruments (at AERE Harwell), as the site of the world's first 2nd generation X-ray Synchrotron (the SRS at Daresbury with its suite of SAXS beamlines), and latterly as the location of the world's most successful pulsed source SANS instrument. Indeed, 2009 also marked the 25th Anniversary of neutron operations at ISIS and the opening of a Second Target Station. Whilst the SRS ceased operations in 2008, its mantle has been inherited by the Diamond synchrotron. Many delegates took the opportunity to visit both Diamond and ISIS during a conference excursion. Despite the prevailing global economic downturn, we were delighted that 434 delegates from 32 different countries were able to attend SAS-2009; two-thirds were drawn from the UK, Germany, Japan, the USA and France, but there were also sizeable contingents from Australia, Korea, Taiwan and South America. In many ways this geographical spread reflects the present and emerging distribution, respectively, of 3rd generation X-ray synchrotrons and high-flux neutron sources, although the scope of the conference was not solely limited to these probes. Financial support from the IUCr enabled us to grant bursaries to attend SAS-2009 to 12 delegates from emerging countries (Algeria, Argentina, Brazil, India, Nepal, Romania, Russia and the Ukraine). The

  2. SAS 2.0丰收期即将到来?

    Institute of Scientific and Technical Information of China (English)

    袁绍龙

    2009-01-01

    @@ SAS技术诞生8年以来经历了重重考验,现在SAS2.0走入产品化,也意味着苦熬多年的SAS技术即将迎来自己的丰收期. 2001年11月26号,Compaq、IBM、LSI、Maxtor和Seagate联合宣布成立SAS(Serial Attached SCSI,也称串行SCSI)工作组,标志着SAS正式走入存储的舞台.一晃近8年时间过去了,从刚开始的广泛质疑到现在的逐渐接受,SAS技术在这8年中经历了重重考验.

  3. SAS-2 observations of celestial diffuse gamma radiation above 30 MeV

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Hartman, R. C.

    1974-01-01

    The small astronomy satellite, SAS-2, used a 32-deck magnetic core digitized spark chamber to study gamma rays with energies above 30 MeV. Data for four regions of the sky away from the galactic plane were analyzed. These regions show a finite, diffuse flux of gamma rays with a steep energy spectrum, and the flux is uniform over all the regions. Represented by a power law, the differential energy spectrum shows an index of 2.5 + or - 0.4. The steep SAS-2 spectrum and the lower energy data are reasonably consistent with a neutral pion gamma-ray spectrum which was red-shifted (such as that proposed by some cosmological theories). It is concluded that the diffuse celestial gamma ray spectrum observed presents the possibility of cosmological studies and possible evidence for a residual cosmic ray density, and supports the galactic superclusters of matter and antimatter remaining from baryon-symmetric big bang.

  4. The PLK4-STIL-SAS-6 module at the core of centriole duplication.

    Science.gov (United States)

    Arquint, Christian; Nigg, Erich A

    2016-10-15

    Centrioles are microtubule-based core components of centrosomes and cilia. They are duplicated exactly once during S-phase progression. Central to formation of each new (daughter) centriole is the formation of a nine-fold symmetrical cartwheel structure onto which microtubule triplets are deposited. In recent years, a module comprising the protein kinase polo-like kinase 4 (PLK4) and the two proteins STIL and SAS-6 have been shown to stay at the core of centriole duplication. Depletion of any one of these three proteins blocks centriole duplication and, conversely, overexpression causes centriole amplification. In this short review article, we summarize recent insights into how PLK4, STIL and SAS-6 co-operate in space and time to form a new centriole. These advances begin to shed light on the very first steps of centriole biogenesis.

  5. Síndrome de apnea del sueño (SAS Sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Camilo José Borrego Abello

    1994-03-01

    Full Text Available Se describe el síndrome de apnea del sueño (SAS abarcando los aspectos históricos, signos y síntomas, las diversas modalidades (apneas obstructiva, central y mixta, complicaciones, principalmente cardiovasculares y cerebrovasculares y formas de tratamiento. Se hace énfasis en la ayuda diagnóstica del polisomnograma que ha permitido definir como SAS síntomas antes considerados inespecíficos y cuantificar su gravedad. Se describen las diversas medidas terapéuticas, locales y generales, recalcando los beneficios que se obtienen con la aplicación de los aparatos de respiración a presión positiva. Estos permiten tratamientos no invasivos que hacen desaparecer la totalidad de los síntomas y evitan los riesgos incrementados de trastornos cardiovasculares y accidentes laborales o de tránsito. Este grave síndrome afecta a un grupo grande de población por lo que su importancia es indudable.

    Different aspects of the sleep apnea síndrome (SAS are described, including history, clinical manifestations, clinical forms (obstructive, central and mixed, cardiovascular, cerebrovascular and other complications and treatment. With the use of the polysomnogram it has been possible to define non-specific symptoms as due to SAS and to quantitate their seriousness. Different therapeutic approaches are described, both local and systemic, with emphasis on the benefits obtained from the use of positive pressure breathing machines which control every manifestation of the syndrome and avoid the increased cardiovascular risks aswell as work and traffic accidents. This syndrome is important in terms of frequency and of increased death risk.

  6. Simple and flexible SAS and SPSS programs for analyzing lag-sequential categorical data.

    Science.gov (United States)

    O'Connor, B P

    1999-11-01

    This paper describes simple and flexible programs for analyzing lag-sequential categorical data, using SAS and SPSS. The programs read a stream of codes and produce a variety of lag-sequential statistics, including transitional frequencies, expected transitional frequencies, transitional probabilities, adjusted residuals, z values, Yule's Q values, likelihood ratio tests of stationarity across time and homogeneity across groups or segments, transformed kappas for unidirectional dependence, bidirectional dependence, parallel and nonparallel dominance, and significance levels based on both parametric and randomization tests.

  7. Immunomagnetic separation and visual fluorescence detection of Salmonella spp., using AOAC approved SAS Molecular Tests.

    Science.gov (United States)

    Bapanpally, Chandra; Maganty, Gayatri; Khan, Shah; Kasra, Akif; Morey, Amit

    2014-01-01

    The SAS Molecular Tests method for detection of Salmonella spp. in various food matrixes has been certified by the AOAC Research Institute and designated Performance Tested Method No. 021202. The current method modification includes the optional immunomagnetic separation (IMS) to enrich the bacteria as well as optional visual fluorescence readout without the use of a turbidimeter. The modifications were validated against the U.S. Department of Agriculture/ Food Safety and Inspection Service Microbiology Laboratory Guidebook (MLG) and the U.S. Food and Drug Administration Bacteriological Analytical Manual (BAM) reference methods. Food matrixes (chicken carcass rinse, beef trim, and spinach) were inoculated with low levels of Salmonella spp. (0.2-2 CFU/test portion) to generate fractional positives (5-15) in 20 inoculated samples. Samples were enriched with SAS Enrichment medium and incubated at 42 +/- 1 degree C. Enrichments were tested directly and subjected to anti-Salmonella IMS prior to the SAS Molecular Tests. Results were determined via visual fluorescence and via turbidity using a turbidimeter. All replicates were confirmed using the MLG or BAM reference method procedures, regardless of presumptive result. The SAS Molecular Tests Salmonella Detection modified methods were determined to be equivalent to the reference methods for the detection of Salmonella in chicken carcass rinse, beef trim, and fresh spinach. The inclusion of IMS in the modified method improved the detection rate of Salmonella in chicken carcass rinses and spinach. The optional use of visual fluorescent reagent and heat block either with IMS or without IMS produced results that were comparable to the results obtained from using a real-time turbidimeter.

  8. Learning SAS’s Perl Regular Expression Matching the Easy Way: By Doing

    Science.gov (United States)

    2015-01-12

    Regular Expression ( PRX ) functions were added in SAS9. The key to learning how to use them is learning PRX metacharacter behavior within a PRX match. The...more you practice PRX matching, the more proficient you become. Ideally, practice would involve a method for repeating the matching process so as to...regex_learning_tool allows both beginner and expert to efficiently practice PRX matching by selecting and processing only the match records that the user is interested

  9. Poisson回归模型的SAS GENMOD实现方法

    Institute of Scientific and Technical Information of China (English)

    孟小平

    2000-01-01

    通过实例演示了Poisson回归模型的SAS程序实现方法,采用SAS GENMOD过程进行Poisson回归分析,结果齐全、应用灵活,为服从Poisson分布的队列、随访等频数资料提供了有力的分析工具.

  10. Recent results of X-ray observations from OSO-7 and SAS-3

    Science.gov (United States)

    Clark, G. W.

    1978-01-01

    Recent observations bearing on the nature of compact X-ray sources obtained from the MIT instruments aboard OSO-7 and SAS-3 are discussed. Results on the X-ray sky survey, new ultralow-energy X-ray sources, X-ray sources in globular clusters, slow X-ray pulsars, and variability and position of compact X-ray sources in Cen A are discussed. Descriptions of the satellite-borne X-ray instruments are provided.

  11. SAS-3 observations of an X-ray flare from Cygnus X-1

    Science.gov (United States)

    Canizares, C. R.; Bradt, H.; Buff, J.; Laufer, B.

    1976-01-01

    Preliminary results are presented for the SAS-3 observation of an X-ray flare from Cygnus X-1. The 1.5 to 6 keV intensity rose by a factor of four and exhibited variability on several time scales from seconds to hours. The 6 to 15 keV intensity showed less activity. The event is similar to that observed by ANS and Ariel 5, but lasted less than two weeks.

  12. SAS统计分析软件模块揽要%Profiles on Modules of SAS

    Institute of Scientific and Technical Information of China (English)

    黄伟; 黄瑜

    2008-01-01

    SAS(Statistics Analysis System)是20世纪60年代初美国SAS公司研发的统计分析软件.SAS与SPSS及BMDP并称为国际上最有知名度的三大统计软件,如今,在我国社会科学乃至自然科学领域已得到了广泛应用.

  13. The ligand Sas and its receptor PTP10D drive tumour-suppressive cell competition.

    Science.gov (United States)

    Yamamoto, Masatoshi; Ohsawa, Shizue; Kunimasa, Kei; Igaki, Tatsushi

    2017-02-09

    Normal epithelial cells often exert anti-tumour effects against nearby oncogenic cells. In the Drosophila imaginal epithelium, clones of oncogenic cells with loss-of-function mutations in the apico-basal polarity genes scribble or discs large are actively eliminated by cell competition when surrounded by wild-type cells. Although c-Jun N-terminal kinase (JNK) signalling plays a crucial role in this cell elimination, the initial event, which occurs at the interface between normal cells and polarity-deficient cells, has not previously been identified. Here, through a genetic screen in Drosophila, we identify the ligand Sas and the receptor-type tyrosine phosphatase PTP10D as the cell-surface ligand-receptor system that drives tumour-suppressive cell competition. At the interface between the wild-type 'winner' and the polarity-deficient 'loser' clones, winner cells relocalize Sas to the lateral cell surface, whereas loser cells relocalize PTP10D there. This leads to the trans-activation of Sas-PTP10D signalling in loser cells, which restrains EGFR signalling and thereby enables elevated JNK signalling in loser cells, triggering cell elimination. In the absence of Sas-PTP10D, elevated EGFR signalling in loser cells switches the role of JNK from pro-apoptotic to pro-proliferative by inactivating the Hippo pathway, thereby driving the overgrowth of polarity-deficient cells. These findings uncover the mechanism by which normal epithelial cells recognize oncogenic polarity-deficient neighbours to drive cell competition.

  14. Solubilization of the poorly water soluble drug, telmisartan, using supercritical anti-solvent (SAS) process.

    Science.gov (United States)

    Park, Junsung; Cho, Wonkyung; Cha, Kwang-Ho; Ahn, Junhyun; Han, Kang; Hwang, Sung-Joo

    2013-01-30

    Telmisartan is a biopharmaceutical classification system (BCS) class II drug that has extremely low water solubility but is freely soluble in highly alkalized solutions. Few organic solvents can dissolve telmisartan. This solubility problem is the main obstacle achieving the desired bioavailability. Because of its unique characteristics, the supercritical anti-solvent (SAS) process was used to BCS class II drug in a variety of ways including micronization, amorphization and solid dispersion. Solid dispersions were prepared using hydroxypropylmethylcellulose/polyvinylpyrrolidone (HPMC/PVP) at 1:0.5, 1:1, and 1:2 weight ratios of drug to polymer, and pure telmisartan was also treated using the SAS process. Processed samples were characterized for morphology, particle size, crystallinity, solubility, dissolution rate and polymorphic stability. After the SAS process, all samples were converted to the amorphous form and were confirmed to be hundreds nm in size. Solubility and dissolution rate were increased compared to the raw material. Solubility tended to increase with increases in the amount of polymer used. However, unlike the solubility results, the dissolution rate decreased with increases in polymer concentration due to gel layer formation of the polymer. Processed pure telmisartan showed the best drug release even though it had lower solubility compared to other solid dispersions; however, because there were no stabilizers in processed pure telmisartan, it recrystallized after 1 month under severe conditions, while the other solid dispersion samples remained amorphous form. We conclude that after controlling the formulation of solid dispersion, the SAS process could be a promising approach for improving the solubility and dissolution rate of telmisartan.

  15. Imaging seismic reflections

    NARCIS (Netherlands)

    Op 't Root, Timotheus Johannes Petrus Maria

    2011-01-01

    The goal of reflection seismic imaging is making images of the Earth subsurface using surface measurements of reflected seismic waves. Besides the position and orientation of subsurface reflecting interfaces it is a challenge to recover the size or amplitude of the discontinuities. We investigate tw

  16. Tracer attenuation in groundwater

    Science.gov (United States)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  17. Cosmic radiation and airline pilots. Exposure patterns of Norwegian SAS-pilots 1960 to 1994

    Energy Technology Data Exchange (ETDEWEB)

    Tveten, U.

    1997-02-01

    The work which is presented in this report is part of a Norwegian epidemiological project, carried out in cooperation between Institutt for Energiteknikk (IFE), the Norwegian Cancer Registry (NCR) and the Norwegian Radiation Protection Authority (NRPA). The project has been partially financed by the Norwegian Research Council. Originating from the Norwegian project, a number of similar projects have been started or are in the planning stage in a number of European countries. The present report lays the ground for estimation of individual exposure histories to cosmic radiation of pilots employed by the Scandinavian Airline System (SAS). The results presented in this report (radiation doserates for the different types of aircraft in the different years) will, in a later stage of the project, be utilized to estimate the individual radiation exposure histories. The major sources of information used as basis for this work is the collection of old SAS time tables found in the SAS Museum at Fornebu Airport in Oslo, and information provided by members of the Pilots Associations.

  18. Adaptation and Validation of the Sexual Assertiveness Scale (SAS) in a Sample of Male Drug Users.

    Science.gov (United States)

    Vallejo-Medina, Pablo; Sierra, Juan Carlos

    2015-04-21

    The aim of the present study was to adapt and validate the Sexual Assertiveness Scale (SAS) in a sample of male drug users. A sample of 326 male drug users and 322 non-clinical males was selected by cluster sampling and convenience sampling, respectively. Results showed that the scale had good psychometric properties and adequate internal consistency reliability (Initiation = .66, Refusal = .74 and STD-P = .79). An evaluation of the invariance showed strong factor equivalence between both samples. A high and moderate effect of Differential Item Functioning was only found in items 1 and 14 (∆R 2 Nagelkerke = .076 and .037, respectively). We strongly recommend not using item 1 if the goal is to compare the scores of both groups, otherwise the comparison will be biased. Correlations obtained between the CSFQ-14 and the safe sex ratio and the SAS subscales were significant (CI = 95%) and indicated good concurrent validity. Scores of male drug users were similar to those of non-clinical males. Therefore, the adaptation of the SAS to drug users provides enough guarantees for reliable and valid use in both clinical practice and research, although care should be taken with item 1.

  19. Living Together v. Living Well Together: A Normative Examination of the SAS Case

    Directory of Open Access Journals (Sweden)

    Lori G. Beaman

    2016-04-01

    Full Text Available The European Court of Human Rights decision in SAS from France illustrates how a policy and national mantra that ostensibly aims to enhance inclusiveness, ‘living together’, is legally deployed in a manner that may have the opposite effect. In essence, despite acknowledging the sincerity of SAS’s religious practice of wearing the niqab, and her agency in making the decision to do so, the Court focuses on radicalism and women’s oppression amongst Muslims. Taking the notion of living together as the beginning point, the paper explores the normative assumptions underlying this notion as illustrated in the judgment of the Court. An alternative approach, drawing on the work of Derrida for the notion of ‘living well together’ will be proposed and its implications for social inclusion explicated. The paper’s aim is to move beyond the specific example of SAS and France to argue that the SAS pattern of identifying particular values as ‘national values’, the deployment of those values through law, policy and public discourse, and their exclusionary effects is playing out in a number of Western democracies, including Canada, the country with which the author is most familiar. Because of this widespread dissemination of values and their framing as representative of who ‘we’ are, there is a pressing need to consider the potentially alienating effects of a specific manifestation of ‘living together’ and an alternative model of ‘living well together’.

  20. Embedding SAS approach into conjugate gradient algorithms for asymmetric 3D elasticity problems

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Chu; Warsi, N.A. [Clark Atlanta Univ., GA (United States); Sameh, A. [Univ. of Minnesota, Minneapolis, MN (United States)

    1996-12-31

    In this paper, we present two strategies to embed the SAS (symmetric-and-antisymmetric) scheme into conjugate gradient (CG) algorithms to make solving 3D elasticity problems, with or without global reflexive symmetry, more efficient. The SAS approach is physically a domain decomposition scheme that takes advantage of reflexive symmetry of discretized physical problems, and algebraically a matrix transformation method that exploits special reflexivity properties of the matrix resulting from discretization. In addition to offering large-grain parallelism, which is valuable in a multiprocessing environment, the SAS scheme also has the potential for reducing arithmetic operations in the numerical solution of a reasonably wide class of scientific and engineering problems. This approach can be applied directly to problems that have global reflexive symmetry, yielding smaller and independent subproblems to solve, or indirectly to problems with partial symmetry, resulting in loosely coupled subproblems. The decomposition is achieved by separating the reflexive subspace from the antireflexive one, possessed by a special class of matrices A, A {element_of} C{sup n x n} that satisfy the relation A = PAP where P is a reflection matrix (symmetric signed permutation matrix).

  1. [Perioperative management in children with sleep apnea syndrome (SAS) undergoing adenoidotonsillectomy].

    Science.gov (United States)

    Mizuno, Ju; Nemoto, Mikiko; Sato, Tomoko; Yokoyama, Takeshi; Hanaoka, Kazuo

    2013-02-01

    We should take care of the occurrences of apnea and hypopnea after emergence from general anesthesia in the children with sleep apnea syndrome (SAS) due to an increase in sensitivity to opioid agonists given for previous recurrent hypoxia. Preoperative assessment for SAS with apnea hypopnea index (AHI), oxygen desaturation index (ODI), and minimum artery oxygen saturation by pulse oxymetry (lowest SpO2) obtained from polysomnography (PSG) test could help to predict the postoperative respiratory depression. In perioperative management in the children with SAS who are candidates for adenotonsillectomy, the dose of opioid agonists during anesthesia maintenance for purpose of postoperative analgesia and sedation should be reduced; postoperative respiratory and circulatory management with monitoring of respiratory movement of the thoracoabdominal part, and electrographic (ECG) and SpO2 monitoring should be continued intensively under long-term oxygen administration; and airway management, nasal continuous positive airway pressure (nCPAP), and artificial ventilation should be prepared for the occurrence of postoperative respiratory depression.

  2. PSHREG: a SAS macro for proportional and nonproportional subdistribution hazards regression.

    Science.gov (United States)

    Kohl, Maria; Plischke, Max; Leffondré, Karen; Heinze, Georg

    2015-02-01

    We present a new SAS macro %pshreg that can be used to fit a proportional subdistribution hazards model for survival data subject to competing risks. Our macro first modifies the input data set appropriately and then applies SAS's standard Cox regression procedure, PROC PHREG, using weights and counting-process style of specifying survival times to the modified data set. The modified data set can also be used to estimate cumulative incidence curves for the event of interest. The application of PROC PHREG has several advantages, e.g., it directly enables the user to apply the Firth correction, which has been proposed as a solution to the problem of undefined (infinite) maximum likelihood estimates in Cox regression, frequently encountered in small sample analyses. Deviation from proportional subdistribution hazards can be detected by both inspecting Schoenfeld-type residuals and testing correlation of these residuals with time, or by including interactions of covariates with functions of time. We illustrate application of these extended methods for competing risk regression using our macro, which is freely available at: http://cemsiis.meduniwien.ac.at/en/kb/science-research/software/statistical-software/pshreg, by means of analysis of a real chronic kidney disease study. We discuss differences in features and capabilities of %pshreg and the recent (January 2014) SAS PROC PHREG implementation of proportional subdistribution hazards modelling.

  3. [Perioperative management of an obese patient complicated with sleep apnea syndrome (SAS) undergoing awake craniotomy].

    Science.gov (United States)

    Komayama, Noriaki; Kamata, Kotoe; Maruyama, Takashi; Nitta, Masayuki; Muragaki, Yoshihiro; Ozaki, Makoto

    2014-10-01

    Both obesity (BMI over 30) and SAS are risks for Supper airway maintenance. We report an obese patient (BMI 33.5) with SAS who underwent awake craniotomy. Weight reduction was instructed 1 month before the operation, and the patient lost enough weight to use intraoperative MRI. Under general anesthesia, surgical pads containing 2% lidocaine with adrenaline were inserted into the nasal cavities. The patient's airway S was secured by i-gel® until dura was opened. A nasal airway was then inserted to confirm the upper airway patency and anesthetics were terminated The patient regained consciousness and started respiration. The i-gel® was removed. The nasal airway was changed to an RAE tracheal tube ; the tube was fixed above the vocal cords under bronchofiberscopic observation. Continuous positive airway pressure (CPAP) via RAE tube was started. Neither coughing nor epistaxis was observed.The RAE tube prevented glossoptosis and did not disturb speech mapping. Emergent endotracheal intubation was easily managed because the tube was close to the glottis. The RAE tube was removed and nasal CP AP was applied overnight Carefully prepared CP AP support via nasal RAE tube was practical in keeping upper airway patency for an obese patient complicated with SAS undergoing awake craniotomy.

  4. 基于SAS-WEBLOGIC的数据挖掘模型及应用%Data mining model and application based on SAS-weblogic

    Institute of Scientific and Technical Information of China (English)

    宋丽红

    2009-01-01

    提出了一种基于SAS-Weblogic的数据挖掘模型,SAS作为数据挖掘语言处于模型的核心,Weblogic作为中间构件,负责SAS数据集联系前端浏览器和后台数据库,起着监控和管理作用.该模型适用于大中型数据挖掘应用,为现代企业提供了一种重要的决策支持系统模型.最后通过实验证明了模型的有效性.

  5. Deterministic seismic hazard macrozonation of India

    Science.gov (United States)

    Kolathayar, Sreevalsa; Sitharam, T. G.; Vipin, K. S.

    2012-10-01

    Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of seismic hazard analysis of India (6°-38°N and 68°-98°E) based on the deterministic approach using latest seismicity data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the seismic sources within a radius of 300 to 400 km. Rock level peak horizontal acceleration (PHA) and spectral accelerations for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.

  6. Deterministic seismic hazard macrozonation of India

    Indian Academy of Sciences (India)

    Sreevalsa Kolathayar; T G Sitharam; K S Vipin

    2012-10-01

    Earthquakes are known to have occurred in Indian subcontinent from ancient times. This paper presents the results of seismic hazard analysis of India (6°–38°N and 68°–98°E) based on the deterministic approach using latest seismicity data (up to 2010). The hazard analysis was done using two different source models (linear sources and point sources) and 12 well recognized attenuation relations considering varied tectonic provinces in the region. The earthquake data obtained from different sources were homogenized and declustered and a total of 27,146 earthquakes of moment magnitude 4 and above were listed in the study area. The sesismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones which are associated with earthquakes of magnitude 4 and above. A new program was developed in MATLAB for smoothing of the point sources. For assessing the seismic hazard, the study area was divided into small grids of size 0.1° × 0.1° (approximately 10 × 10 km), and the hazard parameters were calculated at the center of each of these grid cells by considering all the seismic sources within a radius of 300 to 400 km. Rock level peak horizontal acceleration (PHA) and spectral accelerations for periods 0.1 and 1 s have been calculated for all the grid points with a deterministic approach using a code written in MATLAB. Epistemic uncertainty in hazard definition has been tackled within a logic-tree framework considering two types of sources and three attenuation models for each grid point. The hazard evaluation without logic tree approach also has been done for comparison of the results. The contour maps showing the spatial variation of hazard values are presented in the paper.

  7. SOAR Telescope seismic performance II: seismic mitigation

    Science.gov (United States)

    Elias, Jonathan H.; Muñoz, Freddy; Warner, Michael; Rivera, Rossano; Martínez, Manuel

    2016-07-01

    We describe design modifications to the SOAR telescope intended to reduce the impact of future major earthquakes, based on the facility's experience during recent events, most notably the September 2015 Illapel earthquake. Specific modifications include a redesign of the encoder systems for both azimuth and elevation, seismic trigger for the emergency stop system, and additional protections for the telescope secondary mirror system. The secondary mirror protection may combine measures to reduce amplification of seismic vibration and "fail-safe" components within the assembly. The status of these upgrades is presented.

  8. Micromechanics of Seismic Wave Propagation in Granular Rocks

    Science.gov (United States)

    Nihei, Kurt Toshimi

    1992-09-01

    This thesis investigates the details of seismic wave propagation in granular rocks by examining the micromechanical processes which take place at the grain level. Grain contacts are identified as the primary sites of attenuation in dry and fluid-saturated rocks. In many sedimentary rocks such as sandstones and limestones, the process of diagenesis leaves the grains only partially cemented together. When viewed at the micron scale, grain contacts are non-welded interfaces similar in nature to large scale joints and faults. Using a lumped properties approximation, the macroscopic properties of partially cemented grain contacts are modeled using a displacement-discontinuity boundary condition. This model is used to estimate the magnitude and the frequency dependence of the grain contact scattering attenuation for an idealized grain packing geometry. Ultrasonic P- and S-wave group velocity and attenuation measurements on sintered glass beads, alundum, and Berea sandstones were performed to determine the effects of stress, frequency, and pore fluid properties in granular materials with sintered and partially sintered grain contacts. P - and S-wave attenuation displayed the same overall trends for tests with n-decane, water, silicone oil, and glycerol. The magnitudes of the attenuation coefficients were, in general, higher for S-waves. The experimental measurements reveal that viscosity-dependent attenuation dominates in material with sintered grain contacts. Viscosity-dependent attenuation is also observed in Berea sandstone but only at hydrostatic stresses in excess of 15 MPa where the grain contacts are highly stiffened. Fluid surface chemistry-related attenuation was observed in Berea sandstone loaded uniaxially. These measurements suggest that attenuation in fluid-saturated rocks with partially cemented grain contacts is dependent on both the fluid properties and the state of stress at the grain contacts. A numerical method for simulating seismic wave propagation in

  9. Estimating Bodywave Arrivals and Attenuation from Seismic Noise

    Science.gov (United States)

    2009-09-30

    power) and Figure 3d the standardized site amplification terms from Savage and Helmberger (2004) who used the Pnl ratio of vertical to radial energy...incident Pnl waves, Bull. Seismol. Soc. Am. 94: 357-362. Shearer, P. (1997). Improving local earthquake locations using the LI norm and waveform

  10. Seismic Wave Attenuation and Yield Determination at Regional Distances

    Science.gov (United States)

    1989-05-25

    method uses efficient orthogonal decomposition of matrices with Housholder transformations. Eigenvalues of transformed system are modified according to...Garcia and E. Gimenez (1987). Desarrollo de instrumentacion geofisica para su operacion en condicidnes antarticas, Actas del Segundo Sym- posium Espanol

  11. Characteristics of coda wave attenuation in Yunnan area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The characteristic of seismic coda wave attenuation in Yunnan area in 7 frequency-bands range from 1 Hz to 20 Hz was estimated by using the local earthquake's waveform data recorded from 22 Yunnan digital seismic stations.Coda attenuation Q-c1 of each station was firstly calculated by single scattering method. Then, mean free path Le and seismic albedo Bo of each station were calculated, and scattering attenuation Q-1s and intrinsic attenuation Q-1i were separated from total attenuation Q-1t by multiple lapse time window analysis based on the multiple scattering model in uniform random isotropic scattering medium. The attenuating characteristics in Yunnan show that most value of Le are in 10~30 km, with maximal within 2~6 Hz;Bo are about 0.5 at 1~2 Hz, but less than 0.5at other frequency-bands, which means Q-1i is comparable with Q-1s at 1~2 Hz, and after 1~2 Hz, Q-1i is greater than Q-1s and dominates the attenuation process. Q-1c is close to Q-1i at other frequency bands except 1~2 Hz.Results show that Q-1 especially Qs-1 varies spatially, Q-1 in eastern Yunnan zone is a bit higher than in northwestern Yunnan zone;northwestern Yunnan zone higher than southwestern Yunnan zone. Comparing with other results in global, Qs-1 in Yunnan is lower than the global average value among these results, Q-1i is higher than the global average value, and Q-1t lies the middle among these results.

  12. Regional estimation of Q from seismic coda observations by the Gauribidanur seismic array (southern India)

    Science.gov (United States)

    Tripathi, Jayant Nath; Ugalde, Arantza

    2004-07-01

    Attenuation properties of the lithosphere in southern India are estimated from 1219 vertical-component, short-period observations of microearthquake codas recorded by the Gauribidanur seismic array. The magnitudes of the earthquakes range from 0.3 to 3.7 and have focal depths less than 10 km. Coda-wave attenuation ( Qc-1) is estimated by means of a single isotropic scattering method and a multiple lapse time window analysis based on the hypothesis of multiple isotropic scattering and uniform distribution of scatterers is used to estimate the contribution of intrinsic absorption ( Qi-1) and scattering ( Qs-1) to total attenuation ( Qt-1). All the attenuation parameters are estimated, as a function of frequency for hypocentral distances up to 255 km. Results show a frequency dependent relation of the Qc-1 values in the range 1-10 Hz that fit the power law Q -1(f)=Q 0-1(f/f 0) ηA Q 0-1 value of 0.014 and a decrease of f-1.2 have been found using data from the whole region. On the other hand, scattering attenuation is found to be greater than intrinsic absorption for all the frequency bands. A high value of the seismic albedo (which ranges from 0.68 to 1) is found which indicates that scattering is the dominant effect in the study region. Nevertheless, the attenuation parameters estimated are much lower than the obtained for other regions in the world. On the other hand, the observed energy at 0-15 s from the S-wave arrival time bends significantly downward with decreasing distance. In order to clarify this phenomenon, there is a need to take into account the vertical varying velocity structure in the theoretical model.

  13. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  14. Seismic Barrier Protection of Critical Infrastructure

    Science.gov (United States)

    Haupt, R.; Liberman, V.; Rothschild, M.

    2016-12-01

    Each year, on average a major magnitude-8 earthquake strikes somewhere in the world. In addition, 10,000 earthquake related deaths occur annually, where collapsing buildings claim by far most lives. Moreover, in recent events, industry activity of oil extraction and wastewater reinjection are suspect to cause earthquake swarms that threaten high-value oil pipeline networks, U.S. oil storage reserves, and civilian homes. Earthquake engineering building structural designs and materials have evolved over many years to minimize the destructive effects of seismic surface waves. However, even under the best engineering practices, significant damage and numbers of fatalities can still occur. In this effort, we present a concept and approach to redirect and attenuate the ground motion amplitudes of earthquake surface waves by implementing an engineered subsurface seismic barrier. The barrier is comprised of a borehole array complex that impedes and diverts destructive surface waves (typically 2-10 km wavelengths). Computational 2D and 3D seismic wave propagation models developed at MIT Lincoln Laboratory suggest that the borehole array arrangement is critical to the redirection and self-interference reduction of broadband hazardous seismic waves in the vicinity of the structure to protect. For validity, the computational models are compared with data obtained from large bench-scale physical models that contain scaled borehole arrays and trenches. Small contact shakers generate elastic waves in solid media, while contact tri-axial accelerometer arrays measure the resultant wave fields. Field tests are presently being conducted to examine the seismic power reduction across a subsurface borehole array generated by controlled, far-field seismic sources. The sources include a weight drop and oriented seismic vibrational sources that generate low frequency surface and body waves. The pre-borehole condition at the site is measured first with a tri-axial geophone arrangement. The

  15. Seismic codas on the earth and the moon - A comparison

    Science.gov (United States)

    Dainty, A. M.; Toksoz, M. N.

    1981-01-01

    The seismic codas, representing that part of the seismogram following the arrival of the surface waves or the direct S waves, characteristic of the earth and moon are compared with regard to the implications of coda characteristics for scattering and attenuation. Scattering models based on single S-S scatter theory, in which seismic energy in the coda is assumed to be S waves that have undergone only one scattering without conversion, and on diffusion theory, which assumed that energy in the coda has been scattered many times, are examined, and situations where the single-scattering and multiple-scattering theories are applicable are distinguished by the ratio of attenuation distance to the scattering mean free path. Values of the attenuation distance and the mean free path derived from coda studies for the earth and moon are compared, and it is found that for the frequency range 0.5-10 Hz, diffusion scattering is important in lunar codas, while at frequencies from 1 to 25 Hz single scattering is important in terrestrial codas. It is pointed out that attenuation acts to eliminate scattering paths much longer than the attenuation length. The observed differences between terrestrial and lunar codas are thus attributed to lesser attenuation and greater scattering on the moon.

  16. FORTRAN computer program for seismic risk analysis

    Science.gov (United States)

    McGuire, Robin K.

    1976-01-01

    A program for seismic risk analysis is described which combines generality of application, efficiency and accuracy of operation, and the advantage of small storage requirements. The theoretical basis for the program is first reviewed, and the computational algorithms used to apply this theory are described. The information required for running the program is listed. Published attenuation functions describing the variation with earthquake magnitude and distance of expected values for various ground motion parameters are summarized for reference by the program user. Finally, suggestions for use of the program are made, an example problem is described (along with example problem input and output) and the program is listed.

  17. The Relationship Among Bedrock Seismic Ground Motion Parameters with Different Exceedance Probabilities in the Panxi Area

    Institute of Scientific and Technical Information of China (English)

    Lei Jiancheng

    2003-01-01

    Based on the calculation of the bedrock effective peak acceleration (EPA) zoning map in the Panxi area, the ratios of EPA with exceedance probabilities of 63%, 5%, 3%, 2% and 1% over 50 years to that of 10% in 50 years are 0.302, 1.30, 1.55, 1.76 and 2.14, respectively. The seismic effect will be conservative and safe if taking this zoning map as the earthquake-resistant fortification level and following the relevant rules of the Code for Seismic Design of Buildings (GBJ11-89) to calculate the seismic effect. Furthermore, the main factors that influence the A10/A63 ratios have been found to be the attenuation relationship of seismic ground motion, the division of seismic potential source regions and the seismicity parameters. These achievements are helpful to the spreading and applying of the zoning map.

  18. Signal-to-noise ratio application to seismic marker analysis and fracture detection

    Institute of Scientific and Technical Information of China (English)

    Xu Hui-Qun; and Gui Zhi-Xian

    2014-01-01

    Seismic data with high signal-to-noise ratios (SNRs) are useful in reservoir exploration. To obtain high SNR seismic data, significant effort is required to achieve noise attenuation in seismic data processing, which is costly in materials, and human and financial resources. We introduce a method for improving the SNR of seismic data. The SNR is calculated by using the frequency domain method. Furthermore, we optimize and discuss the critical parameters and calculation procedure. We applied the proposed method on real data and found that the SNR is high in the seismic marker and low in the fracture zone. Consequently, this can be used to extract detailed information about fracture zones that are inferred by structural analysis but not observed in conventional seismic data.

  19. Seismic wave imaging in visco-acoustic media

    Institute of Scientific and Technical Information of China (English)

    WANG Huazhong; ZHANG Libin; MA Zaitian

    2004-01-01

    Realistic representation of the earth may be achieved by combining the mechanical properties of elastic solids and viscousliquids. That is to say, the amplitude will be attenuated withdifferent frequency and the phase will be changed in the seismicdata acquisition. In the seismic data processing, this effect mustbe compensated. In this paper, we put forward a visco-acoustic wavepropagator which is of better calculating stability and tolerablecalculating cost (little more than an acoustic wave propagator).The quite good compensation effect is demonstrated by thenumerical test results with synthetic seismic data and real data.

  20. The Seismic Wavefield

    Science.gov (United States)

    Kennett, B. L. N.

    2002-12-01

    The two volumes of The Seismic Wavefield are a comprehensive guide to the understanding of seismograms in terms of physical propagation processes within the Earth. The focus is on the observation of earthquakes and man-made sources on all scales, for both body waves and surface waves. Volume I provides a general introduction and a development of the theoretical background for seismic waves. Volume II looks at the way in which observed seismograms relate to the propagation processes. Volume II also discusses local and regional seismic events, global wave propagation, and the three-dimensional Earth.

  1. Research on seismic stress triggering

    Institute of Scientific and Technical Information of China (English)

    万永革; 吴忠良; 周公威; 黄静; 秦立新

    2002-01-01

    This paper briefly reviews basic theory of seismic stress triggering. Recent development on seismic stress triggering has been reviewed in the views of seismic static and dynamic stress triggering, application of viscoelastic model in seismic stress triggering, the relation between earthquake triggering and volcanic eruption or explosion, other explanation of earthquake triggering, etc. And some suggestions for further study on seismic stress triggering in near future are given.

  2. Usual Dietary Intakes: SAS Macros for Estimating Ratios of Two Dietary Components that are Consumed Nearly Every Day

    Science.gov (United States)

    The following SAS macros can be used to create a bivariate distribution of usual intake of two dietary components that are consumed nearly every day and to calculate percentiles of the population distribution of the ratio of usual intakes.

  3. Repositioning the substrate activity screening (SAS) approach as a fragment-based method for identification of weak binders.

    Science.gov (United States)

    Gladysz, Rafaela; Cleenewerck, Matthias; Joossens, Jurgen; Lambeir, Anne-Marie; Augustyns, Koen; Van der Veken, Pieter

    2014-10-13

    Fragment-based drug discovery (FBDD) has evolved into an established approach for "hit" identification. Typically, most applications of FBDD depend on specialised cost- and time-intensive biophysical techniques. The substrate activity screening (SAS) approach has been proposed as a relatively cheap and straightforward alternative for identification of fragments for enzyme inhibitors. We have investigated SAS for the discovery of inhibitors of oncology target urokinase (uPA). Although our results support the key hypotheses of SAS, we also encountered a number of unreported limitations. In response, we propose an efficient modified methodology: "MSAS" (modified substrate activity screening). MSAS circumvents the limitations of SAS and broadens its scope by providing additional fragments and more coherent SAR data. As well as presenting and validating MSAS, this study expands existing SAR knowledge for the S1 pocket of uPA and reports new reversible and irreversible uPA inhibitor scaffolds.

  4. De novo centriole formation in human cells is error-prone and does not require SAS-6 self-assembly.

    Science.gov (United States)

    Wang, Won-Jing; Acehan, Devrim; Kao, Chien-Han; Jane, Wann-Neng; Uryu, Kunihiro; Tsou, Meng-Fu Bryan

    2015-11-26

    Vertebrate centrioles normally propagate through duplication, but in the absence of preexisting centrioles, de novo synthesis can occur. Consistently, centriole formation is thought to strictly rely on self-assembly, involving self-oligomerization of the centriolar protein SAS-6. Here, through reconstitution of de novo synthesis in human cells, we surprisingly found that normal looking centrioles capable of duplication and ciliation can arise in the absence of SAS-6 self-oligomerization. Moreover, whereas canonically duplicated centrioles always form correctly, de novo centrioles are prone to structural errors, even in the presence of SAS-6 self-oligomerization. These results indicate that centriole biogenesis does not strictly depend on SAS-6 self-assembly, and may require preexisting centrioles to ensure structural accuracy, fundamentally deviating from the current paradigm.

  5. Validation of SCALE (SAS2H) Isotopic Predictions for BWR Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, O.W.

    1998-01-01

    Thirty spent fuel samples obtained from boiling-water-reactor (BWR) fuel pins have been modeled at Oak Ridge National Laboratory using the SAS2H sequence of the SCALE code system. The SAS2H sequence uses transport methods combined with the depletion and decay capabilities of the ORIGEN-S code to estimate the isotopic composition of fuel as a function of its burnup history. Results of these calculations are compared with chemical assay measurements of spent fuel inventories for each sample. Results show reasonable agreement between measured and predicted isotopic concentrations for important actinides; however, little data are available for most fission products considered to be important for spent fuel concerns (e.g., burnup credit, shielding, source-term calculations, etc.). This work is a follow-up to earlier works that studied the ability to predict spent fuel compositions in pressurized-water-reactor (PWR) fuel pins. Biases and uncertainties associated with BWR isotopic predictions are found to be larger than those of PWR calculations. Such behavior is expected, as the operation of a BWR is significantly more complex than that of a PWR plant, and in general the design of a BWR has a more heterogeneous configuration than that of a PWR. Nevertheless, this work shows that the simple models employed using SAS2H to represent such complexities result in agreement to within 5% (and often less than 1%) or less for most nuclides important for spent fuel applications. On the other hand, however, the set of fuel samples analyzed represent a small subset of the BWR fuel population, and results reported herein may not be representative of the full population of BWR spent fuel.

  6. Validation of SCALE (SAS2H) isotopic predictions for BWR spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, O.W.; DeHart, M.D.

    1998-09-01

    Thirty spent fuel samples obtained from boiling-water-reactor (BWR) fuel pins have been modeled at Oak Ridge National Laboratory using the SAS2H sequence of the SCALE code system. The SAS2H sequence uses transport methods combined with the depletion and decay capabilities of the ORIGEN-S code to estimate the isotopic composition of fuel as a function of its burnup history. Results of these calculations are compared with chemical assay measurements of spent fuel inventories for each sample. Results show reasonable agreement between measured and predicted isotopic concentrations for important actinides; however, little data are available for most fission products considered to be important for spent fuel concerns (e.g., burnup credit, shielding, source-term calculations, etc.). This work is a follow-up to earlier works that studied the ability to predict spent fuel compositions in pressurized-water-reactor (PWR) fuel pins. Biases and uncertainties associated with BWR isotopic predictions are found to be larger than those of PWR calculations. Such behavior is expected, as the operation of a BWR is significantly more complex than that of a PWR plant, and in general the design of a BWR has a more heterogeneous configuration than that of a PWR. Nevertheless, this work shows that the simple models employed using SAS2H to represent such complexities result in agreement to within 5% (and often less than 1%) or less for most nuclides important for spent fuel applications. On the other hand, however, the set of fuel samples analyzed represent a small subset of the BWR fuel population, and results reported herein may not be representative of the full population of BWR spent fuel.

  7. Handling missing data in cluster randomized trials: A demonstration of multiple imputation with PAN through SAS

    Directory of Open Access Journals (Sweden)

    Jiangxiu Zhou

    2014-09-01

    Full Text Available The purpose of this study is to demonstrate a way of dealing with missing data in clustered randomized trials by doing multiple imputation (MI with the PAN package in R through SAS. The procedure for doing MI with PAN through SAS is demonstrated in detail in order for researchers to be able to use this procedure with their own data. An illustration of the technique with empirical data was also included. In this illustration thePAN results were compared with pairwise deletion and three types of MI: (1 Normal Model (NM-MI ignoring the cluster structure; (2 NM-MI with dummy-coded cluster variables (fixed cluster structure; and (3 a hybrid NM-MI which imputes half the time ignoring the cluster structure, and the other half including the dummy-coded cluster variables. The empirical analysis showed that using PAN and the other strategies produced comparable parameter estimates. However, the dummy-coded MI overestimated the intraclass correlation, whereas MI ignoring the cluster structure and the hybrid MI underestimated the intraclass correlation. When compared with PAN, the p-value and standard error for the treatment effect were higher with dummy-coded MI, and lower with MI ignoring the clusterstructure, the hybrid MI approach, and pairwise deletion. Previous studies have shown that NM-MI is not appropriate for handling missing data in clustered randomized trials. This approach, in addition to the pairwise deletion approach, leads to a biased intraclass correlation and faultystatistical conclusions. Imputation in clustered randomized trials should be performed with PAN. We have demonstrated an easy way for using PAN through SAS.

  8. SAS molecular tests Escherichia coli O157 detection kit. Performance tested method 031203.

    Science.gov (United States)

    Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L

    2014-01-01

    The SAS Molecular tests Escherichia coli O157 Detection method, a loop-mediated isothermal amplification method, performed as well as or better than the U.S. Department of Agriculture, Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, bagged mixed lettuce, and fresh spinach. Ground beef (30% fat, 25 g test portion) was validated for 7-8 h enrichment, leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was also shown to be acceptable under conditions of co-enrichment with Salmonella. Thus, after a short co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. The SAS Molecular tests Salmonella Detection Kit was validated using the same test portions as for the SAS Molecular tests E. coli O157 Detection Kit and those results are presented in a separate report. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 50 E. coli 0157 strains, including H7 and non-motile strains, and 30 non-E. coli O157 strains examined. Finally, the method was shown to be robust when variations to DNA extract hold time and DNA volume were varied. The method comparison and robustness data suggest a full 7 h enrichment time should be used for 25 g ground beef test portions.

  9. Human SAS-6 C-Terminus Nucleates and Promotes Microtubule Assembly in Vitro by Binding to Microtubules.

    Science.gov (United States)

    Gupta, Hindol; Badarudeen, Binshad; George, Athira; Thomas, Geethu Emily; Gireesh, K K; Manna, Tapas K

    2015-10-20

    Centrioles are essential components of the animal centrosome and play crucial roles in the formation of cilia and flagella. They are cylindrical structures composed of nine triplet microtubules organized around a central cartwheel. Recent studies have identified spindle assembly abnormal protein SAS-6 as a critical component necessary for formation of the cartwheel. However, the molecular details of how the cartwheel participates in centriolar microtubule assembly have not been clearly understood. In this report, we show that the C-terminal tail (residues 470-657) of human SAS-6, HsSAS-6 C, the region that has been shown to extend toward the centriolar wall where the microtubule triplets are organized, nucleated and induced microtubule polymerization in vitro. The N-terminus (residues 1-166) of HsSAS-6, the domain known to be involved in formation of the central hub of the cartwheel, did not, however, exert any effect on microtubule polymerization. HsSAS-6 C bound to the microtubules and localized along the lengths of the microtubules in vitro. Microtubule pull-down and coimmunoprecipitation (Co-IP) experiments with S-phase synchronized HeLa cell lysates showed that the endogenous HsSAS-6 coprecipitated with the microtubules, and it mediated interaction with tubulin. Isothermal calorimetry titration and size exclusion chromatography showed that HsSAS-6 C bound to the αβ-tubulin dimer in vitro. The results demonstrate that HsSAS-6 possesses an intrinsic microtubule assembly promoting activity and further implicate that its outer exposed C-terminal tail may play critical roles in microtubule assembly and stabilizing microtubule attachment with the centriolar cartwheel.

  10. Reproducibility in Seismic Imaging

    Directory of Open Access Journals (Sweden)

    González-Verdejo O.

    2012-04-01

    Full Text Available Within the field of exploration seismology, there is interest at national level of integrating reproducibility in applied, educational and research activities related to seismic processing and imaging. This reproducibility implies the description and organization of the elements involved in numerical experiments. Thus, a researcher, teacher or student can study, verify, repeat, and modify them independently. In this work, we document and adapt reproducibility in seismic processing and imaging to spread this concept and its benefits, and to encourage the use of open source software in this area within our academic and professional environment. We present an enhanced seismic imaging example, of interest in both academic and professional environments, using Mexican seismic data. As a result of this research, we prove that it is possible to assimilate, adapt and transfer technology at low cost, using open source software and following a reproducible research scheme.

  11. Seismic Fault Preserving Diffusion

    CERN Document Server

    Lavialle, Olivier; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-01-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non linear diffusion filtering leading to a better detection of seismic faults. The non linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  12. Seismic fault preserving diffusion

    Science.gov (United States)

    Lavialle, Olivier; Pop, Sorin; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-02-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non-linear diffusion filtering leading to a better detection of seismic faults. The non-linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  13. BUILDING 341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-15

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  14. Seismicity within the Irpinia Fault System As Monitored By Isnet (Irpinia Seismic Network) and Its Possible Relation with Fluid Storage

    Science.gov (United States)

    Festa, G.; Zollo, A.; Amoroso, O.; Ascione, A.; Colombelli, S.; Elia, L.; Emolo, A.; Martino, C.; Mazzoli, S.; Orefice, A.; Russo, G.

    2014-12-01

    ISNet (http://isnet.fisica.unina.it) is deployed in Southern Apennines along the active fault system responsible for the 1980, M 6.9 Irpinia earthquake. ISNet consists of 32 seismic stations equipped with both strong motion and velocimetric instruments (either broadband or short-period), with the aim of capture a broad set of seismic signals, from ambient noise to strong motion. Real time and near real time procedures run at ISNet with the goal of monitoring the seismicity, check possible space-time anomalies, detect seismic sequences and launch an earthquake early warning in the case of potential significant ground shaking in the area. To understand the role of fluids on the seismicity of the area, we investigated velocity and attenuation models. The former is built from accurate cross-correlation picking and S wave detection based onto polarization analysis. Joint inversion of both P and S arrival times is then based on a linearized multi-scale tomographic approach. Attenuation is instead obtained from inversion of displacement spectra, deconvolving for the source effect. High VP/VS and QS/QP >1 were found within a ~15 km wide rock volume where intense microseismicity is located. This indicates that concentration of seismicity is possibly controlled by high pore fluid pressure. This earthquake reservoir may come from a positive feedback between the seismic pumping that controls the fluid transmission through the fractured damage zone and the low permeability of cross fault barrier, increasing the fluid pore pressure within the fault bounded block. In this picture, sequences mostly occur at the base of this fluid rich layer. They show an anomalous pattern in the earthquake occurrence per magnitude classes; main events evolve with a complex source kinematics, as obtained from backprojection of apparent source time functions, indicating possible directivity effects. In this area sequences might be the key for understanding the transition between the deep

  15. Modelo de franquicia "Wico y Dass Pasteleritos S.A.S"

    OpenAIRE

    2013-01-01

    El modelo de franquicia para la empresa Wico Y Dass Pasteleritos S.A.S. se realizó con base a la investigación en torno al modelo de desarrollo de las franquicias tanto a nivel nacional como internacional, evidenciando en los grandes logros que han obtenido algunas empresas internacionales al aplicar el modelo franquiciario. En Colombia, los tipos de negociación basados en franquicias aún no se encuentran reglamentados por la jurisprudencia colombiana, por lo tanto, fue necesario guia...

  16. Café de la Montaña S.A.S

    OpenAIRE

    2013-01-01

    Crear la empresa Café de la Montaña S.A.S, para la implementación y sostenimiento de 27.500 árboles de café variedad castillo y producir 27.500 Kg de café pergamino seco de alta calidad en la finca La Estrella, vereda Buena Vista, municipio de Campo alegre departamento del Huila. El concepto innovador en este proyecto se encuentra en la implementación de un sistema agroforestal asociado al cultivo de café, además la implementación del modelo becolsub como alternativa para descontaminar los su...

  17. Adaptive Tests of Significance Using Permutations of Residuals with R and SAS

    CERN Document Server

    O'Gorman, Thomas W

    2012-01-01

    Provides the tools needed to successfully perform adaptive tests across a broad range of datasets Adaptive Tests of Significance Using Permutations of Residuals with R and SAS illustrates the power of adaptive tests and showcases their ability to adjust the testing method to suit a particular set of data. The book utilizes state-of-the-art software to demonstrate the practicality and benefits for data analysis in various fields of study. Beginning with an introduction, the book moves on to explore the underlying concepts of adaptive tests, including:Smoothing methods and normalizing transforma

  18. Generation of Synthetic SAS Data for Targets near the Seafloor: Propagation Component

    Science.gov (United States)

    2012-09-30

    ωωϕθω ωω srcijij it imin ti tj jmjn ti ij PFrr BAe rr BAeP ij       −        − =  , (1) where Psrc(ω) is the frequency... application and consists of the source and receiver locations rs and rr and a single image source located at rsi and image receiver at rri. This...range (provide the range meets the far field requirement). IMPACT/ APPLICATIONS The current version of SAS-ST has been used in comparisons with data

  19. %lrasch_mml: A SAS Macro for Marginal Maximum Likelihood Estimation in Longitudinal Polytomous Rasch Models

    Directory of Open Access Journals (Sweden)

    Maja Olsbjerg

    2015-10-01

    Full Text Available Item response theory models are often applied when a number items are used to measure a unidimensional latent variable. Originally proposed and used within educational research, they are also used when focus is on physical functioning or psychological wellbeing. Modern applications often need more general models, typically models for multidimensional latent variables or longitudinal models for repeated measurements. This paper describes a SAS macro that fits two-dimensional polytomous Rasch models using a specification of the model that is sufficiently flexible to accommodate longitudinal Rasch models. The macro estimates item parameters using marginal maximum likelihood estimation. A graphical presentation of item characteristic curves is included.

  20. %lrasch_mml: A SAS Macro for Marginal Maximum Likelihood Estimation in Longitudinal Polytomous Rasch Models

    Directory of Open Access Journals (Sweden)

    Maja Olsbjerg

    2015-10-01

    Full Text Available Item response theory models are often applied when a number items are used to measure a unidimensional latent variable. Originally proposed and used within educational research, they are also used when focus is on physical functioning or psychological wellbeing. Modern applications often need more general models, typically models for multidimensional latent variables or longitudinal models for repeated measurements. This paper describes a SAS macro that fits two-dimensional polytomous Rasch models using a specification of the model that is sufficiently flexible to accommodate longitudinal Rasch models. The macro estimates item parameters using marginal maximum likelihood estimation. A graphical presentation of item characteristic curves is included.

  1. SAS-2 observations of high energy gamma rays from discrete sources

    Science.gov (United States)

    Kniffen, D. A.; Fichtel, C. E.; Hartman, R. C.; Lamb, R. C.; Thompson, D. J.

    1977-01-01

    The SAS-2 identified six localized high energy (greater than 35 MeV) gamma ray sources. Four of these are the radio pulsars, PSR 0531+21, PSR 0833-45, PSR 1818-04, and PSR 1717-46 discovered in a search of 75 radio pulsars. The fact that only one of these is observed in X-rays, and the significant differences in pulse profiles in the gamma ray and radio observations, leads to the speculation that different mechanisms are involved.

  2. Seismic facies; Facies sismicas

    Energy Technology Data Exchange (ETDEWEB)

    Johann, Paulo Roberto Schroeder [PETROBRAS, Rio de Janeiro, RJ (Brazil). Exploracao e Producao Corporativo. Gerencia de Reservas e Reservatorios]. E-mail: johann@petrobras.com.br

    2004-11-01

    The method presented herein describes the seismic facies as representations of curves and vertical matrixes of the lithotypes proportions. The seismic facies are greatly interested in capturing the spatial distributions (3D) of regionalized variables, as for example, lithotypes, sedimentary facies groups and/ or porosity and/or other properties of the reservoirs and integrate them into the 3D geological modeling (Johann, 1997). Thus when interpreted as curves or vertical matrixes of proportions, seismic facies allow us to build a very important tool for structural analysis of regionalized variables. The matrixes have an important application in geostatistical modeling. In addition, this approach provides results about the depth and scale of the wells profiles, that is, seismic data is integrated to the characterization of reservoirs in depth maps and in high resolution maps. The link between the different necessary technical phases involved in the classification of the segments of seismic traces is described herein in groups of predefined traces of two approaches: a) not supervised and b) supervised by the geological knowledge available on the studied reservoir. The multivariate statistical methods used to obtain the maps of the seismic facies units are interesting tools to be used to provide a lithostratigraphic and petrophysical understanding of a petroleum reservoir. In the case studied these seismic facies units are interpreted as representative of the depositional system as a part of the Namorado Turbiditic System, Namorado Field, Campos Basin.Within the scope of PRAVAP 19 (Programa Estrategico de Recuperacao Avancada de Petroleo - Strategic Program of Advanced Petroleum Recovery) some research work on algorithms is underway to select new optimized attributes to apply seismic facies. One example is the extraction of attributes based on the wavelet transformation and on the time-frequency analysis methodology. PRAVAP is also carrying out research work on an

  3. Gypenosides causes DNA damage and inhibits expression of DNA repair genes of human oral cancer SAS cells.

    Science.gov (United States)

    Lu, Kung-Wen; Chen, Jung-Chou; Lai, Tung-Yuan; Yang, Jai-Sing; Weng, Shu-Wen; Ma, Yi-Shih; Tang, Nou-Ying; Lu, Pei-Jung; Weng, Jing-Ru; Chung, Jing-Gung

    2010-01-01

    Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino, a Chinese medical plant. Recently, Gyp has been shown to induce cell cycle arrest and apoptosis in many human cancer cell lines. However, there is no available information to address the effects of Gyp on DNA damage and DNA repair-associated gene expression in human oral cancer cells. Therefore, we investigated whether Gyp induced DNA damage and DNA repair gene expression in human oral cancer SAS cells. The results from flow cytometric assay indicated that Gyp-induced cytotoxic effects led to a decrease in the percentage of viable SAS cells. The results from comet assay revealed that the incubation of SAS cells with Gyp led to a longer DNA migration smear (comet tail) when compared with control and this effect was dose-dependent. The results from real-time PCR analysis indicated that treatment of SAS cells with 180 mug/ml of Gyp for 24 h led to a decrease in 14-3-3sigma, DNA-dependent serine/threonine protein kinase (DNAPK), p53, ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and breast cancer gene 1 (BRCA1) mRNA expression. These observations may explain the cell death caused by Gyp in SAS cells. Taken together, Gyp induced DNA damage and inhibited DNA repair-associated gene expressions in human oral cancer SAS cells in vitro.

  4. Swept Impact Seismic Technique (SIST)

    Science.gov (United States)

    Park, C.B.; Miller, R.D.; Steeples, D.W.; Black, R.A.

    1996-01-01

    A coded seismic technique is developed that can result in a higher signal-to-noise ratio than a conventional single-pulse method does. The technique is cost-effective and time-efficient and therefore well suited for shallow-reflection surveys where high resolution and cost-effectiveness are critical. A low-power impact source transmits a few to several hundred high-frequency broad-band seismic pulses during several seconds of recording time according to a deterministic coding scheme. The coding scheme consists of a time-encoded impact sequence in which the rate of impact (cycles/s) changes linearly with time providing a broad range of impact rates. Impact times used during the decoding process are recorded on one channel of the seismograph. The coding concept combines the vibroseis swept-frequency and the Mini-Sosie random impact concepts. The swept-frequency concept greatly improves the suppression of correlation noise with much fewer impacts than normally used in the Mini-Sosie technique. The impact concept makes the technique simple and efficient in generating high-resolution seismic data especially in the presence of noise. The transfer function of the impact sequence simulates a low-cut filter with the cutoff frequency the same as the lowest impact rate. This property can be used to attenuate low-frequency ground-roll noise without using an analog low-cut filter or a spatial source (or receiver) array as is necessary with a conventional single-pulse method. Because of the discontinuous coding scheme, the decoding process is accomplished by a "shift-and-stacking" method that is much simpler and quicker than cross-correlation. The simplicity of the coding allows the mechanical design of the source to remain simple. Several different types of mechanical systems could be adapted to generate a linear impact sweep. In addition, the simplicity of the coding also allows the technique to be used with conventional acquisition systems, with only minor modifications.

  5. Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2004-10-25

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  6. Seismic hazards in Thailand: a compilation and updated probabilistic analysis

    Science.gov (United States)

    Pailoplee, Santi; Charusiri, Punya

    2016-06-01

    A probabilistic seismic hazard analysis (PSHA) for Thailand was performed and compared to those of previous works. This PSHA was based upon (1) the most up-to-date paleoseismological data (slip rates), (2) the seismic source zones, (3) the seismicity parameters ( a and b values), and (4) the strong ground-motion attenuation models suggested as being suitable models for Thailand. For the PSHA mapping, both the ground shaking and probability of exceedance (POE) were analyzed and mapped using various methods of presentation. In addition, site-specific PSHAs were demonstrated for ten major provinces within Thailand. For instance, a 2 and 10 % POE in the next 50 years of a 0.1-0.4 g and 0.1-0.2 g ground shaking, respectively, was found for western Thailand, defining this area as the most earthquake-prone region evaluated in Thailand. In a comparison between the ten selected specific provinces within Thailand, the Kanchanaburi and Tak provinces had comparatively high seismic hazards, and therefore, effective mitigation plans for these areas should be made. Although Bangkok was defined as being within a low seismic hazard in this PSHA, a further study of seismic wave amplification due to the soft soil beneath Bangkok is required.

  7. Seismic Monitoring System Calibration Using Ground Truth Database

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Winston; Wagner, Robert

    2002-12-22

    Calibration of a seismic monitoring system remains a major issue due to the lack of ground truth information and uncertainties in the regional geological parameters. Rapid and accurate identification of seismic events is currently not feasible due to the absence of a fundamental framework allowing immediate access to ground truth information for many parts of the world. Precise location and high-confidence identification of regional seismic events are the primary objectives of monitoring research in seismology. In the Department of Energy Knowledge Base (KB), ground truth information addresses these objectives and will play a critical role for event relocation and identification using advanced seismic analysis tools. Maintaining the KB with systematic compilation and analysis of comprehensive sets of geophysical data from various parts of the world is vital. The goal of this project is to identify a comprehensive database for China using digital seismic waveform data that are currently unavailable. These data may be analyzed along with ground truth information that becomes available. To date, arrival times for all regional phases are determined on all events above Mb 4.5 that occurred in China in 2000 and 2001. Travel-time models are constructed to compare with existing models. Seismic attenuation models may be constructed to provide better understanding of regional wave propagation in China with spatial resolution that has not previously been obtained.

  8. Spectral-element seismic wave propagation on emerging HPC architectures

    Science.gov (United States)

    Peter, Daniel; Liu, Qiancheng; Komatitsch, Dimitri

    2017-04-01

    Seismic tomography is the most prominent approach to infer physical properties of Earth's internal structures such as compressional- and shear-wave speeds, anisotropy and attenuation. Using seismic signals from ground-motion records, recent advances in full-waveform inversions require increasingly accurate simulations of seismic wave propagation in complex 3D media to provide access to the complete 3D seismic wavefield. However, such numerical simulations are computationally expensive and need high-performance computing (HPC) facilities for further improving the current state of knowledge. During recent years, new multi- and many-core architectures such as graphics processing units (GPUs) have been added to available large HPC systems. GPU-accelerated computing together with advances in multi-core central processing units (CPUs) can greatly accelerate scientific applications. To employ a wide variety of hardware accelerators for seismic wave propagation simulations, we incorporated a code generation tool BOAST into an existing spectral-element code package SPECFEM3D_GLOBE. This allows us to use meta-programming of computational kernels and generate optimized source code for both CUDA and OpenCL languages, running simulations on either CUDA or OpenCL hardware accelerators. We show here benchmark applications of seismic wave propagation on GPUs and CPUs, comparing performances on emerging hardware architectures.

  9. Detection of sasX gene in Staphylococcus aureus and molecular epidemiological characteristics%金黄色葡萄球菌sasX基因的检测及其分子流行特征

    Institute of Scientific and Technical Information of China (English)

    钟一鸣; 丁健生; 刘文恩; 李虹玲; 晏群; 刘清霞

    2016-01-01

    目的:调查医院金黄色葡萄球菌 sasX 基因的携带情况并探究其分子流行特征,为揭示该基因在本地区的流行状况提供依据。方法收集中南大学湘雅医院2012年1-12月临床分离鉴定的金黄色葡萄球菌128株,采用 PCR 检测 sasX 基因,对该基因阳性的菌株采用多重 PCR 检测 SCCmec 分型、PCR 扩增 pvl 毒素基因,并进行多位点序列分型(MLST )和葡萄球菌 A 蛋白序列分析。结果128株金黄色葡萄球菌中共检测出2株 sasX 基因阳性菌株,检出率为1.6%,经头孢西丁鉴定这2株菌株均为耐甲氧西林金黄色葡萄球菌(MRSA),SCCmec Ⅲ分型均为 SCCmec Ⅲ型,pv l 基因均阴性,MLST 分型为 ST239,spa 分型为 t037型。结论首次在湖南地区临床分离的金黄色葡萄球菌中发现存在 sasX 基因,sasX 基因可能是导致医院持续感染的毒力因素之一,应密切关注其流行发展趋势。%OBJECTIVE To investigate the prevalence of sasX gene in Staphylococcus aureus (S .aureus) strains and explore the molecular epidemiological characteristics so as to reveal the prevalence of the gene in this area . METHODS A total of 128 clinical S .aureus isolates were collected from Xiangya Hospital ,Central South Universi-ty from Jan 2012 to Dec 2012 ,then the sasX gene was detected by using PCR ,the SCCmec Ⅲ genotypes were de-tected for the sasX-positive strains with the use of multiple PCR ,the pvl toxin gene was amplified by PCR ,the multilocus sequence typing (MLST) was conducted to determine the sequence types(STs) ,and the staphylococcal protein A sequence typing (spa) of the sasX-positive strains was performed .RESULTS Of the 128 strains of S .au-reus ,2 were detected positive for the sasX gene ,with the detection rate 1 .6% ;both of the 2 strains were identi-fied as methicillin-resistant S .aureus (MRSA) by cefoxitin ,all of the SCCmec Ⅲ genotypes were SCCmec Ⅲ ,and the pvl gene was detected

  10. Seismicity in Northern Germany

    Science.gov (United States)

    Bischoff, Monika; Gestermann, Nicolai; Plenefisch, Thomas; Bönnemann, Christian

    2013-04-01

    Northern Germany is a region of low tectonic activity, where only few and low-magnitude earthquakes occur. The driving tectonic processes are not well-understood up to now. In addition, seismic events during the last decade concentrated at the borders of the natural gas fields. The source depths of these events are shallow and in the depth range of the gas reservoirs. Based on these observations a causal relationship between seismicity near gas fields and the gas production is likely. The strongest of these earthquake had a magnitude of 4.5 and occurred near Rotenburg in 2004. Also smaller seismic events were considerably felt by the public and stimulated the discussion on the underlying processes. The latest seismic event occurred near Langwedel on 22nd November 2012 and had a magnitude of 2.8. Understanding the causes of the seismicity in Northern Germany is crucial for a thorough evaluation. Therefore the Seismological Service of Lower Saxony (NED) was established at the State Office for Mining, Energy and Geology (LBEG) of Lower Saxony in January 2013. Its main task is the monitoring and evaluation of the seismicity in Lower Saxony and adjacent areas. Scientific and technical questions are addressed in close cooperation with the Seismological Central Observatory (SZO) at the Federal Institute for Geosciences and Natural Resources (BGR). The seismological situation of Northern Germany will be presented. Possible causes of seismicity are introduced. Rare seismic events at greater depths are distributed over the whole region and probably are purely tectonic whereas events in the vicinity of natural gas fields are probably related to gas production. Improving the detection threshold of seismic events in Northern Germany is necessary for providing a better statistical basis for further analyses answering these questions. As a first step the existing seismic network will be densified over the next few years. The first borehole station was installed near Rethem by BGR

  11. Seismic base isolation by nonlinear mode localization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [University of Illinois, Department of Civil and Environmental Engineering, Urbana, IL (United States); Washington University, Department of Civil and Environmental Engineering, St. Louis, MO (United States); McFarland, D.M. [University of Illinois, Department of Aerospace Engineering, Urbana, IL (United States); Vakakis, A.F. [National Technical University of Athens, Division of Mechanics (Greece); Bergman, L.A. [University of Illinois, Department of Mechanical and Industrial Engineering, Urbana, IL (United States)

    2005-03-01

    In this paper, the performance of a nonlinear base-isolation system, comprised of a nonlinearly sprung subfoundation tuned in a 1:1 internal resonance to a flexible mode of the linear primary structure to be isolated, is examined. The application of nonlinear localization to seismic isolation distinguishes this study from other base-isolation studies in the literature. Under the condition of third-order smooth stiffness nonlinearity, it is shown that a localized nonlinear normal mode (NNM) is induced in the system, which confines energy to the subfoundation and away from the primary or main structure. This is followed by a numerical analysis wherein the smooth nonlinearity is replaced by clearance nonlinearity, and the system is excited by ground motions representing near-field seismic events. The performance of the nonlinear system is compared with that of the corresponding linear system through simulation, and the sensitivity of the isolation system to several design parameters is analyzed. These simulations confirm the existence of the localized NNM, and show that the introduction of simple clearance nonlinearity significantly reduces the seismic energy transmitted to the main structure, resulting in significant attenuation in the response. (orig.)

  12. Social Anxiety Scale for Adolescents (SAS-A: Psychometric properties in a Spanish-speaking population

    Directory of Open Access Journals (Sweden)

    José Olivares

    2005-01-01

    Full Text Available El objetivo de este estudio instrumental fue estudiar la estructura factorial y propiedades psicométricas de la Escala de Ansiedad Social para Adolescentes (SASA. Participaron 2407 adolescentes (1263 chicos y 1144 chicas, con una edad media de 15 años, alumnos de nueve institutos de la región de Murcia. Los resultados obtenidos apoyan la estructura tri-factorial propuesta por los autores de la escala (FNE, SAD-New, SAD-General. Se encontraron correlaciones interescalas significativas y niveles de consistencia interna elevados para las subescalas, así como respecto de los efectos del sexo en la puntuación SAS-A/Total y en sus subescalas, alcanzando las chicas las puntuaciones más elevadas. Sólo se hallaron diferencias significativas para la edad en la subescala FNE y no se constataron efectos de interacción entre los dos factores. Estos hallazgos parecen avalar el uso de la SAS-A en población adolescente de habla española.

  13. Preparation and Physicochemical Properties of 10-Hydroxycamptothecin (HCPT Nanoparticles by Supercritical Antisolvent (SAS Process

    Directory of Open Access Journals (Sweden)

    Baoyou Zhang

    2011-04-01

    Full Text Available The goal of the present work was to study the feasibility of 10-hydroxycamptothecin (HCPT nanoparticle preparation using supercritical antisolvent (SAS precipitation. The influences of various experimental factors on the mean particle size (MPS of HCPT nanoparticles were investigated. The optimum micronization conditions are determined as follows: HCPT solution concentration 0.5 mg/mL, the flow rate ratio of CO2 and HCPT solution 19.55, precipitation temperature 35 °C and precipitation pressure 20 MPa. Under the optimum conditions, HCPT nanoparticles with a MPS of 180 ± 20.3 nm were obtained. Moreover, the HCPT nanoparticles obtained were characterized by Scanning electron microscopy, Dynamic light scattering, Fourier-transform infrared spectroscopy, High performance liquid chromatography-mass spectrometry, X-ray diffraction and Differential scanning calorimetry analyses. The physicochemical characterization results showed that the SAS process had not induced degradation of HCPT. Finally, the dissolution rates of HCPT nanoparticles were investigated and the results proved that there is a significant increase in dissolution rate compared to unprocessed HCPT.

  14. Krāsas un atmosfēra Edgara Alana Po dzejā

    OpenAIRE

    Kļimova, Kristīna

    2009-01-01

    Bakalaura darba tēma ir krāsas un noskaņa Edgar Allana Po dzejā. Pētījuma uzdevums ir noteikt biežāk lietojamos tēlainās izteiksmes līdzekļus un krāsas Edgara Po dzejā, turklāt identificēt gaisotni un noskaņu šajos darbos. Darba autore ir veikusi pētījumu balstoties uz praktiskām un teorētiskām zināšanām. Teorētiskā daļa iztirzā tāda veida problēmas kā: tēlainās izteiksmes līdzekļu būtību, simbolu un simbolsisko krāsu izmantošana literatūrā, ka arī to nozīmi Edgara Allana Po dzejā, un cit...

  15. MLGA: A SAS Macro to Compute Maximum Likelihood Estimators via Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Francisco Juretig

    2015-08-01

    Full Text Available Nonlinear regression is usually implemented in SAS either by using PROC NLIN or PROC NLMIXED. Apart from the model structure, initial values need to be specified for each parameter. And after some convergence criteria are fulfilled, the second order conditions need to be analyzed. But numerical problems are expected to appear in case the likelihood is nearly discontinuous, has plateaus, multiple maxima, or the initial values are distant from the true parameter estimates. The usual solution consists of using a grid, and then choosing the set of parameters reporting the highest log-likelihood. However, if the amount of parameters or grid points is large, the computational burden will be excessive. Furthermore, there is no guarantee that, as the number of grid points increases, an equal or better set of points will be found. Genetic algorithms can overcome these problems by replicating how nature optimizes its processes. The MLGA macro is presented; it solves a maximum likelihood estimation problem under normality through PROC GA, and the resulting values can later be used as the starting values in SAS nonlinear procedures. As will be demonstrated, this macro can avoid the usual trial and error approach that is needed when convergence problems arise. Finally, it will be shown how this macro can deal with complicated restrictions involving multiple parameters.

  16. Efficiency prediction for a low head bulb turbine with SAS SST and zonal LES turbulence models

    Science.gov (United States)

    Jošt, D.; Škerlavaj, A.

    2014-03-01

    A comparison between results of numerical simulations and measurements for a 3-blade bulb turbine is presented in order to determine an appropriate numerical setup for accurate and reliable simulations of flow in low head turbines. Numerical analysis was done for three angles of runner blades at two values of head. For the smallest blade angle the efficiency was quite accurately predicted, but for the optimal and maximal blade angles steady state analysis entirely failed to predict the efficiency due to underestimated torque on the shaft and incorrect results in the draft tube. Transient simulation with SST did not give satisfactory results, but with SAS and zonal LES models the prediction of efficiency was significantly improved. From the results obtained by SAS and zonal LES the interdependence between turbulence models, vortex structures in the flow, values of eddy viscosity and flow energy losses in the draft tube can be seen. Also the effect of using the bounded central differential scheme instead of the high resolution scheme was evident. To test the effect of grid density, simulations were performed on four grids. While a difference between results obtained on the basic grid and on the fine grid was small, the results obtained on the coarse grids were not satisfactory.

  17. Comparing the importance of prognostic factors in Cox and logistic regression using SAS.

    Science.gov (United States)

    Heinze, Georg; Schemper, Michael

    2003-06-01

    Two SAS macro programs are presented that evaluate the relative importance of prognostic factors in the proportional hazards regression model and in the logistic regression model. The importance of a prognostic factor is quantified by the proportion of variation in the outcome attributable to this factor. For proportional hazards regression, the program %RELIMPCR uses the recently proposed measure V to calculate the proportion of explained variation (PEV). For the logistic model, the R(2) measure based on squared raw residuals is used by the program %RELIMPLR. Both programs are able to compute marginal and partial PEV, to compare PEVs of factors, of groups of factors, and even to compare PEVs of different models. The programs use a bootstrap resampling scheme to test differences of the PEVs of different factors. Confidence limits for P-values are provided. The programs further allow to base the computation of PEV on models with shrinked or bias-corrected parameter estimates. The SAS macros are freely available at www.akh-wien.ac.at/imc/biometrie/relimp

  18. Final SAS-2 gamma ray results on sources in the galactic anticenter region

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Lamb, R. C.

    1976-01-01

    Analysis of SAS-2 high energy Gamma ray data from the direction of the galactic anticenter shows that this region is characterized by: a diffuse emission from the galactic plane which has a maximum along b=0 deg and an enhancement toward negative latitudes associated with Gould's Belt, a strong point source in the direction of the Crab nebula, and a second intense localized source near galactic coordinates 195 deg, +5 deg. Gamma ray emission from the Crab source is dominated by a pulsed flux from PSR 0531+21. The total flux above 100MeV is 3.7 + or - 0.8 million/sq cm s. The source near 195 deg, + 5 deg has a flux above 100 MeV of 4.3 + or - 0.9 million/sq cm s. Its spectrum appears flatter than that of the Crab. The diffuse galactic plane emission at negative lattitudes shows a general correlation with the local matter distribution associated with Gould's Belt. The calculated Gamma ray intensity agrees well with the SAS-2 observations.

  19. Effects of 2D and 3D Error Fields on the SAS Divertor Magnetic Topology

    Science.gov (United States)

    Trevisan, G. L.; Lao, L. L.; Strait, E. J.; Guo, H. Y.; Wu, W.; Evans, T. E.

    2016-10-01

    The successful design of plasma-facing components in fusion experiments is of paramount importance in both the operation of future reactors and in the modification of operating machines. Indeed, the Small Angle Slot (SAS) divertor concept, proposed for application on the DIII-D experiment, combines a small incident angle at the plasma strike point with a progressively opening slot, so as to better control heat flux and erosion in high-performance tokamak plasmas. Uncertainty quantification of the error fields expected around the striking point provides additional useful information in both the design and the modeling phases of the new divertor, in part due to the particular geometric requirement of the striking flux surfaces. The presented work involves both 2D and 3D magnetic error field analysis on the SAS strike point carried out using the EFIT code for 2D equilibrium reconstruction, V3POST for vacuum 3D computations and the OMFIT integrated modeling framework for data analysis. An uncertainty in the magnetic probes' signals is found to propagate non-linearly as an uncertainty in the striking point and angle, which can be quantified through statistical analysis to yield robust estimates. Work supported by contracts DE-FG02-95ER54309 and DE-FC02-04ER54698.

  20. Development and validation of logistic prognostic models by predefined SAS-macros

    Directory of Open Access Journals (Sweden)

    Ziegler, Christoph

    2006-02-01

    Full Text Available In medical decision making about therapies or diagnostic procedures in the treatment of patients the prognoses of the course or of the magnitude of diseases plays a relevant role. Beside of the subjective attitude of the clinician mathematical models can help in providing such prognoses. Such models are mostly multivariate regression models. In the case of a dichotomous outcome the logistic model will be applied as the standard model. In this paper we will describe SAS-macros for the development of such a model, for examination of the prognostic performance, and for model validation. The rational for this developmental approach of a prognostic modelling and the description of the macros can only given briefly in this paper. Much more details are given in. These 14 SAS-macros are a tool for setting up the whole process of deriving a prognostic model. Especially the possibility of validating the model by a standardized software tool gives an opportunity, which is not used in general in published prognostic models. Therefore, this can help to develop new models with good prognostic performance for use in medical applications.

  1. Seismic Hazard analysis of Adjaria Region in Georgia

    Science.gov (United States)

    Jorjiashvili, Nato; Elashvili, Mikheil

    2014-05-01

    distribution [Youngs and Coppersmith, 1985]. Notably, the software can deal with uncertainty in the seismicity input parameters such as maximum magnitude value. CRISIS offers a set of built-in GMPEs, as well as the possibility of defining new ones by providing information in a tabular format. Our study shows that in case of Ajaristkali HPP study area, significant contribution to Seismic Hazard comes from local sources with quite low Mmax values, thus these two attenuation lows give us quite different PGA and SA values.

  2. [Use of the anatomical cemented femoral stem SAS I: mid-term results].

    Science.gov (United States)

    Mikláš, M; Pink, M; Valoušek, T

    2015-01-01

    PURPOSE OF THE STUDY In view of increasing interest in a relationship between the surface of an implant and its behaviour and longevity in total hip arthroplasty (THA), the aim of this study is to present the clinical and radiographic results, as well as complications, of hip replacement surgery using the cemented femoral stem SAS I. MATERIAL AND METHODS A total of 298 cemented femoral stems SAS I were implanted in 275 patients at our department between 1996 and 2005. The patient average age was 72.1 years, with the range from 64 to 92 years. The pre-operative diagnoses were as follows: primary osteoarthritis in 179 (30.1%); post-dysplastic osteoarthritis in 41 (13.7%); femoral neck fracture in 44 (14.8%); avascular necrosis of the femoral head in 23 (7.7%); rheumatoid arthritis in nine (3%) and other causes in two (0.7%) patients. Of the 275 patients who had the surgery, 186 (204 THAs) underwent clinical and X-ray examination at an average follow-up of 11.5 years (range, 8 to 17 years). The clinical results were used to calculate the Harris hip score and radiographic evaluation was based on antero-posterior views. RESULTS The group of 186 assessed patients (204 THAs) comprised 106 women and 80 men, who were on average 85.4 years old on evaluation (range, 72 to 92 years). Of the remaining patients, 62 patients (64 THAs) died from causes unrelated to the surgery and 27 patients (30 THAs) were lost to follow-up. The functional outcome of surgery assessed by the Harris hip score was excellent in 61 (32.8%), good in 94 (50.5%), satisfactory in 26 (14%) and poor in five (2.7%) patients. The 93.1% SAS I stem longevity was recorded in relation to aseptic loosening; reimplantation for this indication was performed in 14 THAs. No revision surgery for failure due to valgus/varus deviations of the stem was carried out. Of the 204 hips, 188 had femoral stems aligned in neutral, 12 (5.9%) in valgus and four (2%) in varus positions. DISCUSSION The anatomical femoral stem SAS I

  3. An acoustic eikonal equation for attenuating orthorhombic media

    KAUST Repository

    Hao, Qi

    2017-04-06

    Attenuating orthorhombic models are often used to describe the azimuthal variation of the seismic wave velocity and amplitude in finely layered hydrocarbon reservoirs with vertical fractures. In addition to the P-wave related medium parameters, shear wave parameters are also present in the complex eikonal equation needed to describe the P-wave complex-valued traveltime in an attenuating orthorhombic medium, which increases the complexity of using the P-wave traveltime to invert for the medium parameters in practice. Here, we use the acoustic assumption to derive an acoustic eikonal equation that approximately governs the complex-valued traveltime of P-waves in an attenuating orthorhombic medium. For a homogeneous attenuating orthorhombic media, we solve the eikonal equation using a combination of the perturbation method and Shanks transform. For a horizontal attenuating orthorhombic layer, both the real and imaginary part of the complex-valued reflection traveltime have nonhyperbolic behaviors in terms of the source-receiver offset. Similar to the roles of normal moveout (NMO) velocity and anellipticity, the attenuation NMO velocity and the attenuation anellipticity characterize the variation of the imaginary part of the complex-valued reflection traveltime around zero source-receiver offset.

  4. Broadband Lg Attenuation Modeling in the Middle East

    Energy Technology Data Exchange (ETDEWEB)

    Pasyanos, M E; Matzel, E M; Walter, W R; Rodgers, A J

    2008-08-21

    We present a broadband tomographic model of Lg attenuation in the Middle East derived from source- and site-corrected amplitudes. Absolute amplitude measurements are made on hand-selected and carefully windowed seismograms for tens of stations and thousands of crustal earthquakes resulting in excellent coverage of the region. A conjugate gradient method is used to tomographically invert the amplitude dataset of over 8000 paths over a 45{sup o} x 40{sup o} region of the Middle East. We solve for Q variation, as well as site and source terms, for a wide range of frequencies ranging from 0.5-10 Hz. We have modified the standard attenuation tomography technique to more explicitly define the earthquake source expression in terms of the seismic moment. This facilitates the use of the model to predict the expected amplitudes of new events, an important consideration for earthquake hazard or explosion monitoring applications. The attenuation results have a strong correlation to tectonics. Shields have low attenuation, while tectonic regions have high attenuation, with the highest attenuation at 1 Hz is found in eastern Turkey. The results also compare favorably to other studies in the region made using Lg propagation efficiency, Lg/Pg amplitude ratios and two-station methods. We tomographically invert the amplitude measurements for each frequency independently. In doing so, it appears the frequency-dependence of attenuation is not compatible with the power law representation of Q(f), an assumption that is often made.

  5. Reduction of uncertainties in probabilistic seismic hazard analysis

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Moon; Choun, Young Sun; Choi, In Kil [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-02-01

    An integrated research for the reduction of conservatism and uncertainties in PSHA in Korea was performed. The research consisted of five technical task areas as follows; Task 1: Earthquake Catalog Development for PSHA. Task 2: Evaluation of Seismicity and Tectonics of the Korea Region. Task 3: Development of a Ground Motion Relationships. Task 4: Improvement of PSHA Modelling Methodology. Task 5: Development of Seismic Source Interpretations for the region of Korea for Inputs to PSHA. A series of tests on an ancient wooden house and an analysis on medium size earthquake in Korea were performed intensively. Signification improvement, especially in the estimation of historical earthquake, ground motion attenuation, and seismic source interpretations, were made through this study. 314 refs., 180 figs., 54 tabs. (Author)

  6. Attenuation of S wave in the crust of Ordos massif

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-gui; CHUO Yong-qing; CHEN Shu-qing; JIN Chun-hua

    2005-01-01

    We presented attenuation characteristics of S waves in the crust of Ordos massif. Using 487 pieces of digital oscillograms of 19 seismic events recorded by 32 seismologic stations located on Ordos massif and its surroundings, we have calculated the parameter of three-segment geometric attenuation and give the relation of inelastic attenuation Q value with frequency in the crust of Ordos massif, site responses of 32 stations, and source parameters of 19 events by the genetic algorithm. The results indicate that Q value (at 1 Hz) of S-wave in the crust of Ordos massif is much larger than that in the geologically active tectonic region. The site responses of the 32 stations in the high-frequency section do not show clear amplification effect except one or two stations, while in the low-frequency section, there is difference among the stations. The logarithmic value of seismic moment and the magnitude ML of 19 seismic events has a very good linear relationship.

  7. Landslide seismic magnitude

    Science.gov (United States)

    Lin, C. H.; Jan, J. C.; Pu, H. C.; Tu, Y.; Chen, C. C.; Wu, Y. M.

    2015-11-01

    Landslides have become one of the most deadly natural disasters on earth, not only due to a significant increase in extreme climate change caused by global warming, but also rapid economic development in topographic relief areas. How to detect landslides using a real-time system has become an important question for reducing possible landslide impacts on human society. However, traditional detection of landslides, either through direct surveys in the field or remote sensing images obtained via aircraft or satellites, is highly time consuming. Here we analyze very long period seismic signals (20-50 s) generated by large landslides such as Typhoon Morakot, which passed though Taiwan in August 2009. In addition to successfully locating 109 large landslides, we define landslide seismic magnitude based on an empirical formula: Lm = log ⁡ (A) + 0.55 log ⁡ (Δ) + 2.44, where A is the maximum displacement (μm) recorded at one seismic station and Δ is its distance (km) from the landslide. We conclude that both the location and seismic magnitude of large landslides can be rapidly estimated from broadband seismic networks for both academic and applied purposes, similar to earthquake monitoring. We suggest a real-time algorithm be set up for routine monitoring of landslides in places where they pose a frequent threat.

  8. A probabilistic seismic hazard map of India and adjoining regions

    Directory of Open Access Journals (Sweden)

    H. K. Gupta

    1999-06-01

    Full Text Available This paper presents the results of an exercise carried out under GSHAP, over India and adjoining regions bound by 0°N-40°N and 65°E-100°E. A working catalogue of main shocks was prepared by merging the local catalogues with the NOAA catalogue, and removing duplicates, aftershocks and earthquakes without any magnitude. Eighty six potential seismic source zones were delineated based on the major tectonic features and seismicity trends. Using the probabilistic hazard assessment approach of McGuire, adopted by GSHAP, the Peak Ground Accelerations (PGA were computed for 10% probability of exceedance in 50 years, at locations defined by a grid of 0.5° x 0.5°. Since no reliable estimates of attenuation values are available for the Indian region, the attenuation relation of Joyner and Boore (1981 was used. The PGA values over the grid points were contoured to obtain a seismic hazard map. The hazard map depicts that a majority of the Northern Indian plate boundary region and the Tibetan plateau region have hazard level of the order of 0.25 g with prominent highs of the order of 0.35-0.4 g in the seismically more active zones like the Burmese arc, Northeastern India and Hindukush region. In the Indian shield, the regional seismic hazard, covering a major area, is of the order of 0.05-0.1 g whereas some areas like Koyna depict hazard to the level of 0.2 g. The present map can be converted into a conventional seismic zoning map having four zones with zone factors of 0.1 g, 0.2 g, 0.3 g and 0.4 g respectively.

  9. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  10. Intensity attenuation in the Pannonian Basin

    Science.gov (United States)

    Győri, Erzsébet; Gráczer, Zoltán; Szanyi, Gyöngyvér

    2015-04-01

    Ground motion prediction equations play a key role in seismic hazard assessment. Earthquake hazard has to be expressed in macroseismic intensities in case of seismic risk estimations where a direct relation to the damage associated with ground shaking is needed. It can be also necessary for shake map generation where the map is used for prompt notification to the public, disaster management officers and insurance companies. Although only few instrumental strong motion data are recorded in the Pannonian Basin, there are numerous historical reports of past earthquakes since the 1763 Komárom earthquake. Knowing the intensity attenuation and comparing them with relations of other areas - where instrumental strong motion data also exist - can help us to choose from the existing instrumental ground motion prediction equations. The aim of this work is to determine an intensity attenuation formula for the inner part of the Pannonian Basin, which can be further used to find an adaptable ground motion prediction equation for the area. The crust below the Pannonian Basin is thin and warm and it is overlain by thick sediments. Thus the attenuation of seismic waves here is different from the attenuation in the Alp-Carpathian mountain belt. Therefore we have collected intensity data only from the inner part of the Pannonian Basin and defined the boundaries of the studied area by the crust thickness of 30 km (Windhoffer et al., 2005). 90 earthquakes from 1763 until 2014 have sufficient number of macroseismic data. Magnitude of the events varies from 3.0 to 6.6. We have used individual intensity points to eliminate the subjectivity of drawing isoseismals, the number of available intensity data is more than 3000. Careful quality control has been made on the dataset. The different types of magnitudes of the used earthquake catalogue have been converted to local and momentum magnitudes using relations determined for the Pannonian Basin. We applied the attenuation formula by Sorensen

  11. Considering potential seismic sources in earthquake hazard assessment for Northern Iran

    Science.gov (United States)

    Abdollahzadeh, Gholamreza; Sazjini, Mohammad; Shahaky, Mohsen; Tajrishi, Fatemeh Zahedi; Khanmohammadi, Leila

    2014-07-01

    Located on the Alpine-Himalayan earthquake belt, Iran is one of the seismically active regions of the world. Northern Iran, south of Caspian Basin, a hazardous subduction zone, is a densely populated and developing area of the country. Historical and instrumental documented seismicity indicates the occurrence of severe earthquakes leading to many deaths and large losses in the region. With growth of seismological and tectonic data, updated seismic hazard assessment is a worthwhile issue in emergency management programs and long-term developing plans in urban and rural areas of this region. In the present study, being armed with up-to-date information required for seismic hazard assessment including geological data and active tectonic setting for thorough investigation of the active and potential seismogenic sources, and historical and instrumental events for compiling the earthquake catalogue, probabilistic seismic hazard assessment is carried out for the region using three recent ground motion prediction equations. The logic tree method is utilized to capture epistemic uncertainty of the seismic hazard assessment in delineation of the seismic sources and selection of attenuation relations. The results are compared to a recent practice in code-prescribed seismic hazard of the region and are discussed in detail to explore their variation in each branch of logic tree approach. Also, seismic hazard maps of peak ground acceleration in rock site for 475- and 2,475-year return periods are provided for the region.

  12. Probabilistic seismic hazard map for Bulgaria as a basis for a new building code

    Directory of Open Access Journals (Sweden)

    S. D. Simeonova

    2006-01-01

    Full Text Available A seismic hazard map proposed as part of a new building code for Bulgaria is presented here on basis of the recommendations in EUROCODE 8. Seismic source zones within an area of about 200 km around Bulgaria were constructed considering seismicity, neotectonic and geological development. The most time consuming work was to establish a homogeneous earthquake catalogue out of different catalogues. The probabilistic seismic hazard assessment in terms of intensities is performed following Cornell (1968 with the program EQRISK (see McGuire, 1976, modified by us for use of intensities. To cope with the irregular isoseismals of the Vrancea intermediate depth earthquakes a special attenuation factor is introduced (Ardeleanu et al., 2005, using detailed macroseismic maps of three major earthquakes. The final seismic hazard is the combination of both contributions, of zones with crustal earthquakes and of the Vrancea intermediate depth earthquakes zone. Calculations are done for recurrence periods of 95, 475 and 10 000 years.

  13. 2D Seismic Data Processing for Straight Lines in the Loess Plateaus in Fuxian of Shanbei

    Institute of Scientific and Technical Information of China (English)

    LiMinjie; ChenYequan; ZhangHai; PangShangming; DengGuozhen

    2005-01-01

    The crooked seismic lines along valleys were irregular previously in Fuxian of Shanbei,showing an irregular branch in plane, and hard to complete close grids. Therefore, it's difficult to conduct reservoir inversion of 2D seismic data. In 2001, Zhongyuan Oilfield Company carried out the study on field acquisition methods and seismic processing technology in Fuxian. Straight lines were passing through plateaus and formed seismic grids by using flexible geometry with variable linear bins.Data processing involved model-inversion based refraction static correction, surface consistent amplitude compensation, deconvolution, and pre-stack noise attenuation. As the result, seismic data with a high fidelity was provided for the subsequent reservoir predictions, small-amplitude structure interpretation and integrative geologic study. Because all lines were jointed to form grids, comprehensive interpretation of reservoir inversion could be finally implemented by using the pseudo logging method to control lines without wells.

  14. Seismic imaging of post-glacial sediments - test study before Spitsbergen expedition

    Science.gov (United States)

    Szalas, Joanna; Grzyb, Jaroslaw; Majdanski, Mariusz

    2017-04-01

    This work presents results of the analysis of reflection seismic data acquired from testing area in central Poland. For this experiment we used total number of 147 vertical component seismic stations (DATA-CUBE and Reftek "Texan") with accelerated weight drop (PEG-40). The profile was 350 metres long. It is a part of pilot study for future research project on Spitsbergen. The purpose of the study is to recognise the characteristics of seismic response of post-glacial sediments in order to design the most adequate survey acquisition parameters and processing sequence for data from Spitsbergen. Multiple tests and comparisons have been performed to obtain the best possible quality of seismic image. In this research we examine the influence of receiver interval size, front mute application and surface wave attenuation attempts. Although seismic imaging is the main technique we are planning to support this analysis with additional data from traveltime tomography, MASW and other a priori information.

  15. Studies on seismic source

    Institute of Scientific and Technical Information of China (English)

    李世愚; 陈运泰

    2003-01-01

    During the period of 1999~2002, the Chinese seismologists made a serious of developments in the study on seismic sources including observations, experiments and theory. In the field of observation, the methods of the accuracy location of earthquake sources, the inversion of seismic moment tensor and the mechanism of earthquake source are improved and developed. A lot of important earthquake events are studied by using these methods. The rupture processes of these events are inverted and investigated combined with the local stress fields and the tectonic moment by using the measurements of surface deformation. In the fields of experiments and theory, many developments are obtained in cause of seismic formation, condition of stress and tectonics, dynamics of earthquake rupture, rock fracture and nucleation of strong earthquakes.

  16. The homo-oligomerisation of both Sas-6 and Ana2 is required for efficient centriole assembly in flies.

    Science.gov (United States)

    Cottee, Matthew A; Muschalik, Nadine; Johnson, Steven; Leveson, Joanna; Raff, Jordan W; Lea, Susan M

    2015-05-23

    Sas-6 and Ana2/STIL proteins are required for centriole duplication and the homo-oligomerisation properties of Sas-6 help establish the ninefold symmetry of the central cartwheel that initiates centriole assembly. Ana2/STIL proteins are poorly conserved, but they all contain a predicted Central Coiled-Coil Domain (CCCD). Here we show that the Drosophila Ana2 CCCD forms a tetramer, and we solve its structure to 0.8 Å, revealing that it adopts an unusual parallel-coil topology. We also solve the structure of the Drosophila Sas-6 N-terminal domain to 2.9 Å revealing that it forms higher-order oligomers through canonical interactions. Point mutations that perturb Sas-6 or Ana2 homo-oligomerisation in vitro strongly perturb centriole assembly in vivo. Thus, efficient centriole duplication in flies requires the homo-oligomerisation of both Sas-6 and Ana2, and the Ana2 CCCD tetramer structure provides important information on how these proteins might cooperate to form a cartwheel structure.

  17. Using Seismic Tomography and Holography Ground Imaging to Investigate Ground Conditions

    Institute of Scientific and Technical Information of China (English)

    Ed Kase; Tim Ross

    2004-01-01

    Unforeseen, variable subsurface ground conditions present the greatest challenge to the heavy construction and civil engineering industry in the design, construction, and maintenance of large projects. A detailed, accurate site investigation will reduce project risk, improve construction performance and safety, prolong the life of the tunnel or structure,and prevent waste in over - design. Presently, site characterization and geotechnical engineering are limited by the inability to adequately describe these subsurface ground conditions.NSA Geotechnical Services has successfully applied seismic tomography and holography ground imaging technologies on tunneling and heavy civil excavations worldwide. Seismic signal waveforms traveling through a complex medium consist of various arrivals from refractions, reflections, scattering, and dispersion. Tomography and holography are proven inversion technologies for estimating location and extent of material property variations causing changes in signal waveforms.ent attenuation rates and velocities. Seismic waves will travel faster through competent material and be generally less attenuated than through broken/fractured ground or voids.encounters an interface between ground zones possessing different seismic properties. Most geologic structures, anomalies,and changes in lithology provide detectable seismic reflections if they are within a reasonable distance of the seismic source.This paper will present various applications of these technologies, illustrating how seismic imaging can provide accurate information regarding ground conditions associated with tunneling projects. With this information, engineers can complete projects safely, within time and budget constraints.

  18. Realization of data analysis system for Internet negotiation based on SAS/IntrNet%基于SAS/IntrNet的网上谈判数据分析系统的实现

    Institute of Scientific and Technical Information of China (English)

    冯玉强; 马兴辉

    2005-01-01

    针对SAS统计分析系统局限于单机应用的现状,提出了SAS与Web服务器相结合的方式来弥补SAS系统在Web环境下应用的不足,介绍了利用SAS/IntrNet实现SAS的Web应用的基本原理,给出了SAS/IntrNet程序处理的一般流程和相关配置文件的详细配置方法,解决了SAS/IntrNet系统实现中的几个关键问题.同时给出这一应用的具体实例--网上谈判数据分析系统的具体实现方法.

  19. Real Time View of the Functions and Services of the Seismic Alert System of Mexico (SASMEX)

    Science.gov (United States)

    Espinosa Aranda, J.; Ibarrola Alvarez, G.; Cuellar Martinez, A.; Inostroza Puk, M.

    2013-05-01

    The Seismic Alert System of Mexico (SASMEX) is integrated since March 2012 by the Seismic Alert System of Mexico City (SAS), in continuous operation since 1991, and the Seismic Alert System of Oaxaca City (SASO) that started its services in 2003. SASMEX consists of 97 field seismic sensor station (FS) type triaxial accelerometer, mostly sponsored by the government of Mexico City and secondly by Oaxaca. The SASMEX covers the Pacific seismic hazard among the coast of Jalisco, Colima, Michoacan, Guerrero and Oaxaca; and the seismic region of Puebla and northern Oaxaca and Guerrero states. This integration lets to warn with better opportunity to the population of Mexico City, Oaxaca Oax., Acapulco Gro., Chilpancingo Gro. and recently Morelia Mich.; cities with a system called EASAS where receives seismic data from FS and emits earthquake early warning signals to the population. The recent sponsorship of Federal Government through the General Coordination of Civil Protection and the National Center for Disaster Prevention, reinforced integration SAS and SASO, and auspiced the development of a Real-Time Monitoring System of functions and services of SASMEX. This work show how is displayed the functions of services of SASMEX through this monitoring system and its possible application by Civil Protection authorities. This monitoring system can indicate the status of FS, the communications system and cities with EASAS. Additionally, when an earthquake occurs and is detected by the SASMEX, the monitoring system shows the messages of FS, whose consist in the characteristics of detection and seismic danger forecasted; in the case of a strong earthquake estimated by more than one FS, the EASAS of each city could automatically issue an Alert Public to its population. The monitoring system allows observing cities with EASAS that activate their alerts, displays a basic earthquake propagation model and how it reaches to other FS. Additionally, the monitoring system shows the

  20. Seismic Disaster Reduction in China

    Institute of Scientific and Technical Information of China (English)

    Ministry of Construction

    2001-01-01

    @@ Great accomplishments have been made in seismic disaster reduction in China's engineering construction and city construction projects during the past decade (1990~2000). A new national map on the division of seismic intensity has been promulgated, and a series of anti-seismic standards and norms have been drafted or revised, which has further improved the country's technical code system on anti-seismic engineering measures.

  1. SA-based concrete seismic stress monitoring: a case study for normal strength concrete

    Science.gov (United States)

    Hou, S.; Zhang, H. B.; Ou, J. P.

    2016-09-01

    The stress history of concrete structures that have survived an earthquake can serve as a critical index to evaluate the health of the structure. There are currently few reliable monitoring methods to assess concrete stress after a seismic event. Piezoelectric-based smart aggregate (SA) provides an innovative experimental approach to monitor stress on concrete. The principle of SA-based concrete seismic stress monitoring is based on the assumption that concrete stress can be reliably predicted by the average output voltages of limited SAs with an acceptable margin of error. In this study, the meso-scale randomness of concrete was evaluated throughout the overall stress range of concrete and the influence of different load paths was considered. Four cylindrical specimens of normal strength concrete were embedded with a total of 24 SAs. The SA output sensitivity curve in the paths of loading-unloading with different amplitudes and monotonic loading up to failure was obtained. Monitoring errors were analyzed during pre- and post-peak stages from the experimental results. This research suggests that SA-based concrete seismic stress monitoring for normal strength concrete is reliable.

  2. B341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-01-02

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3. Based on our evaluation the building does not meet a Life Safety performance level for the BSE- 1E earthquake ground shaking hazard. The BSE-1E is the recommended seismic hazard level for evaluation of existing structures and is based on a 20% probability of exceedence in 50 years.

  3. Induced Seismicity Monitoring System

    Science.gov (United States)

    Taylor, S. R.; Jarpe, S.; Harben, P.

    2014-12-01

    There are many seismological aspects associated with monitoring of permanent storage of carbon dioxide (CO2) in geologic formations. Many of these include monitoring underground gas migration through detailed tomographic studies of rock properties, integrity of the cap rock and micro seismicity with time. These types of studies require expensive deployments of surface and borehole sensors in the vicinity of the CO2 injection wells. Another problem that may exist in CO2 sequestration fields is the potential for damaging induced seismicity associated with fluid injection into the geologic reservoir. Seismic hazard monitoring in CO2 sequestration fields requires a seismic network over a spatially larger region possibly having stations in remote settings. Expensive observatory-grade seismic systems are not necessary for seismic hazard deployments or small-scale tomographic studies. Hazard monitoring requires accurate location of induced seismicity to magnitude levels only slightly less than that which can be felt at the surface (e.g. magnitude 1), and the frequencies of interest for tomographic analysis are ~1 Hz and greater. We have developed a seismo/acoustic smart sensor system that can achieve the goals necessary for induced seismicity monitoring in CO2 sequestration fields. The unit is inexpensive, lightweight, easy to deploy, can operate remotely under harsh conditions and features 9 channels of recording (currently 3C 4.5 Hz geophone, MEMS accelerometer and microphone). An on-board processor allows for satellite transmission of parameter data to a processing center. Continuous or event-detected data is kept on two removable flash SD cards of up to 64+ Gbytes each. If available, data can be transmitted via cell phone modem or picked up via site visits. Low-power consumption allows for autonomous operation using only a 10 watt solar panel and a gel-cell battery. The system has been successfully tested for long-term (> 6 months) remote operations over a wide range

  4. GLUMIP 2.0: SAS/IML Software for Planning Internal Pilots

    Directory of Open Access Journals (Sweden)

    John A. Kairalla

    2008-09-01

    Full Text Available Internal pilot designs involve conducting interim power analysis (without interim data analysis to modify the final sample size. Recently developed techniques have been described to avoid the type~I error rate inflation inherent to unadjusted hypothesis tests, while still providing the advantages of an internal pilot design. We present GLUMIP 2.0, the latest version of our free SAS/IML software for planning internal pilot studies in the general linear univariate model (GLUM framework. The new analytic forms incorporated into the updated software solve many problems inherent to current internal pilot techniques for linear models with Gaussian errors. Hence, the GLUMIP 2.0 software makes it easy to perform exact power analysis for internal pilots under the GLUM framework with independent Gaussian errors and fixed predictors.

  5. Computational procedures for probing interactions in OLS and logistic regression: SPSS and SAS implementations.

    Science.gov (United States)

    Hayes, Andrew F; Matthes, Jörg

    2009-08-01

    Researchers often hypothesize moderated effects, in which the effect of an independent variable on an outcome variable depends on the value of a moderator variable. Such an effect reveals itself statistically as an interaction between the independent and moderator variables in a model of the outcome variable. When an interaction is found, it is important to probe the interaction, for theories and hypotheses often predict not just interaction but a specific pattern of effects of the focal independent variable as a function of the moderator. This article describes the familiar pick-a-point approach and the much less familiar Johnson-Neyman technique for probing interactions in linear models and introduces macros for SPSS and SAS to simplify the computations and facilitate the probing of interactions in ordinary least squares and logistic regression. A script version of the SPSS macro is also available for users who prefer a point-and-click user interface rather than command syntax.

  6. Estimation of the concordance correlation coefficient for repeated measures using SAS and R.

    Science.gov (United States)

    Carrasco, Josep L; Phillips, Brenda R; Puig-Martinez, Josep; King, Tonya S; Chinchilli, Vernon M

    2013-03-01

    The concordance correlation coefficient is one of the most common approaches used to assess agreement among different observers or instruments when the outcome of interest is a continuous variable. A SAS macro and R package are provided here to estimate the concordance correlation coefficient (CCC) where the design of the data involves repeated measurements by subject and observer. The CCC is estimated using U-statistics (UST) and variance components (VC) approaches. Confidence intervals and standard errors are reported along with the point estimate of the CCC. In the case of the VC approach, the linear mixed model output and variance components estimates are also provided. The performance of each function is shown by means of some examples with real data sets.

  7. Valoración de empresa Haceb Whirpool Industrial S.A.S.

    OpenAIRE

    Giraldo Cardona, Juan Camilo

    2015-01-01

    Este trabajo presenta la valoración de la empresa Haceb Whirlpool Industrial S.A.S. -- En la primera sección se describe la situación en estudio a través de la presentación de la empresa, una breve reseña histórica de cada uno de los accionistas, información del mercado de electrodomésticos en Colombia (especialmente la relacionada con el mercado de lavadoras), también se describe qué es un Joint Venture y por último la pertinencia de la valoración para los órganos de dirección -- En la segun...

  8. [Calculating Pearson residual in logistic regressions: a comparison between SPSS and SAS].

    Science.gov (United States)

    Xu, Hao; Zhang, Tao; Li, Xiao-song; Liu, Yuan-yuan

    2015-01-01

    To compare the results of Pearson residual calculations in logistic regression models using SPSS and SAS. We reviewed Pearson residual calculation methods, and used two sets of data to test logistic models constructed by SPSS and STATA. One model contained a small number of covariates compared to the number of observed. The other contained a similar number of covariates as the number of observed. The two software packages produced similar Pearson residual estimates when the models contained a similar number of covariates as the number of observed, but the results differed when the number of observed was much greater than the number of covariates. The two software packages produce different results of Pearson residuals, especially when the models contain a small number of covariates. Further studies are warranted.

  9. Plan estratégico para la empresa A.L Telecomunicaciones S.A.S

    OpenAIRE

    Martínez Ascencio, Nohra Alejandra; Fonseca Torrijos, Camila Andrea

    2016-01-01

    El presente trabajo está constituido por cinco capítulos en los que se desarrolla el plan estratégico para la empresa A.L Telecomunicaciones S.A.S. El primer capítulo expone los antecedentes de la compañía y por qué se hace necesaria la elaboración del plan estratégico para el nuevo negocio de la empresa. En el segundo capítulo se elabora la fundamentación teórica, donde se describe la importancia de la planeación estratégica y el direccionamiento estratégico y los conceptos fundamental...

  10. SAS-2 observations of the high energy gamma radiation from the Vela region

    Science.gov (United States)

    Thompson, D. J.; Bignami, G. F.; Fichtel, C. E.; Kniffen, D. A.

    1974-01-01

    Data from a scan of the galactic plane by the SAS-B high energy gamma ray experiment in the region 250 deg smaller than 12 smaller than 290 deg show a statistically significant excess over the general radiation from the galactic plane for gamma radiation of energy larger than 100 MeV. If the enhanced gamma radiation results from interactions of cosmic rays with galactic matter, as the energy spectrum suggests, it seems reasonable to associate the enhancement with large scale galactic features, such as spiral arm segments in that direction, or with the region surrounding the Vela supernova remnant with which PSR 0833-45 is associated. If the excess is attributed to cosmic rays released from the supernova interacting with the interstellar matter in that region, than on the order of 3 x 10 to the 50th power ergs would have been released by that supernova in the form of cosmic rays.

  11. McSAS: A package for extracting quantitative form-free distributions

    CERN Document Server

    Breßler, Ingo; Thünemann, Andreas

    2014-01-01

    A reliable and user-friendly characterisation of nano-objects in a target material is presented here in the form of a software data analysis package for interpreting small-angle X-ray scattering (SAXS) patterns. When provided with data on absolute scale with reasonable uncertainty estimates, the software outputs (size) distributions in absolute volume fractions complete with uncertainty estimates and minimum evidence limits, and outputs all distribution modes of a user definable range of one or more model parameters. A multitude of models are included, including prolate and oblate nanoparticles, core-shell objects, polymer models (Gaussian chain and Kholodenko worm) and a model for densely packed spheres (using the LMA-PY approximations). The McSAS software can furthermore be integrated as part of an automated reduction and analysis procedure in laboratory instruments or at synchrotron beamlines.

  12. The dental X-ray file of crew members in the Scandinavian Airlines System (SAS).

    Science.gov (United States)

    Keiser-Nielsen, S; Johanson, G; Solheim, T

    1981-11-01

    In 1977, the Scandinavian Airlines System (SAS) established a dental X-ray file of all crew members. Its aim was to have immediately available an adequate set of physical antemortem data useful for identification in case of a fatal crash. Recently, an investigation into the quality and suitability of this material was carried out. The radiographs of 100 Danish, 100 Norwegian, and 100 Swedish pilots were picked at random and evaluated for formal deficiences, technical deficiencies, treatment pattern as useful for identification purposes, and the presence of pathology. The major results of the investigation were that a number of formal and technical deficiencies were disclosed, that the treatment pattern would seem adequate for identification purposes, and that a number of pathological findings were made, several of which had to be considered possible safety risks in the form of barodontalgia.

  13. SAS-2 high-energy gamma-ray observations of the Vela pulsar

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Ogelman, H. B.

    1975-01-01

    The Second Small Astronomy Satellite (SAS-2) high-energy (in excess of 35 MeV) gamma-ray telescope has detected pulsed gamma-ray emission at the radio period from PSR 0833-45, the Vela pulsar, as well as an unpulsed flux from the Vela region. The pulsed emission consists of two peaks following the single radio peak by about 13 ms and 48 ms. The luminosity of the pulsed emission above 100 MeV from Vela is about 0.1 that of the pulsar NP 0532 in the Crab nebula, whereas the pulsed emission from Vela at optical wavelengths is less than 0.0002 that from the Crab. The relatively high intensity of the pulsed gamma-ray emission, and the double peak structure, compared with the single pulse in the radio emission, suggest that the high-energy gamma-ray pulsar emission may be produced under different conditions from those at lower energies.

  14. SAS-2 observations of gamma rays from the galactic plane. [noting longitude and latitude observation

    Science.gov (United States)

    Thompson, D. J.; Bignami, G. F.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.

    1974-01-01

    Preliminary data are given for the SAS-2 high energy galactic gamma ray observation. These data include both latitude and longitude distributions. The longitude distribution shows a high density region. The latitude distributions toward the center and the anti-center are markedly different, the former showing a two-component structure of half-widths of approximately 3 and 6 deg. The energy spectrum in the range 35 to 200 MeV is hard, consistent with cosmic ray interactions with interstellar matter, including neutral pions decay and emission from energetic electron interactions. The data is consistent with an interpretation in terms of the confinement of the cosmic rays in the spiral arms.

  15. Final SAS-2 gamma-ray results on sources in the galactic anticenter region

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Lamb, R. C.

    1977-01-01

    Final results are presented for SAS-2 observations of high-energy gamma-rays from the galactic anticenter region. Three main gamma-ray features are shown to characterize this region: a localized source associated with the Crab Nebula and its pulsar, another localized source near galactic coordinates 195 deg, +5 deg, and a general enhancement of the diffuse background 10 to 15 deg south of the galactic plane, which is associated with the Gould Belt. For the Crab, it is found that the radiation is mostly pulsed, the pulsed fraction increases with energy, and the intensity of the radiation in the main and interpulse peaks is approximately the same. The other localized source, provisionally designated as gamma 195+5, is found to have a harder spectrum than the Crab but no obvious radio counterpart; emission from an external galaxy is ruled out.

  16. SAS-2 gamma-ray observations of PSR 1747-46. [radio pulsar

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Ogelman, H. B.; Lamb, R. C.

    1976-01-01

    Evidence is reported for the observation of gamma-ray emission from the radio pulsar PSR 1747-46 by the gamma-ray telescope aboard SAS 2. The evidence is based on the presence of both an approximately 3-sigma enhancement of gamma rays at the pulsar's location and an approximately 4-sigma peak in the phase plot of 79 gamma-ray events whose phase was calculated from the pulsar's known period. The gamma-ray pulsation is found to appear at a phase lag of about 0.16 from that predicted by the radio observations. The pulsed gamma-ray fluxes above 35 MeV and 100 MeV are estimated, and it is shown that the gamma-ray pulse width is similar to the radio pulse width. It is concluded that PSR 1747-46 is a most likely candidate for pulsed gamma-ray emission.

  17. Real Time Seismic Prediction while Drilling

    Science.gov (United States)

    Schilling, F. R.; Bohlen, T.; Edelmann, T.; Kassel, A.; Heim, A.; Gehring, M.; Lüth, S.; Giese, R.; Jaksch, K.; Rechlin, A.; Kopf, M.; Stahlmann, J.; Gattermann, J.; Bruns, B.

    2009-12-01

    Efficient and safe drilling is a prerequisite to enhance the mobility of people and goods, to improve the traffic as well as utility infrastructure of growing megacities, and to ensure the growing energy demand while building geothermal and in hydroelectric power plants. Construction within the underground is often building within the unknown. An enhanced risk potential for people and the underground building may arise if drilling enters fracture zones, karsts, brittle rocks, mixed solid and soft rocks, caves, or anthropogenic obstacles. Knowing about the material behavior ahead of the drilling allows reducing the risk during drilling and construction operation. In drilling operations direct observations from boreholes can be complemented with geophysical investigations. In this presentation we focus on “real time” seismic prediction while drilling which is seen as a prerequisite while using geophysical methods in modern drilling operations. In solid rocks P- and S-wave velocity, refraction and reflection as well as seismic wave attenuation can be used for the interpretation of structures ahead of the drilling. An Integrated Seismic Imaging System (ISIS) for exploration ahead of a construction is used, where a pneumatic hammer or a magnetostrictive vibration source generate repetitive signals behind the tunneling machine. Tube waves are generated which travel along the tunnel to the working face. There the tube waves are converted to mainly S- but also P-Waves which interact with the formation ahead of the heading face. The reflected or refracted waves travel back to the working front are converted back to tube waves and recorded using three-component geophones which are fit into the tips of anchor rods. In near real time, the ISIS software allows for an integrated 3D imaging and interpretation of the observed data, geological and geotechnical parameters. Fracture zones, heterogeneities, and variations in the rock properties can be revealed during the drilling

  18. Numerical Investigation of Pressure Fluctuation in Centrifugal Pump Volute Based on SAS Model and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Qiaorui Si

    2014-02-01

    Full Text Available This paper presents an investigation of pressure fluctuation of a single-suction volute-type centrifugal pump, particularly volute casing, by using numerical and experimental methods. A new type of hybrid Reynolds-averaged Navier-Stokes/Large Eddy Simulation, referred to as the shear stress transport-scale-adaptive simulation (SAS model, is employed to study the unsteady flow. Statistical analysis method is adopted to show the pressure fluctuation intensity distribution in the volute channel. A test rig for pressure pulsation measurement is built to validate the numerical simulation results using eight transient pressure sensors in the middle section of the volute wall. Results show that the SAS model can accurately predict the inner flow field of centrifugal pumps. Radial force acting on the impeller presents a star distribution related to the blade number. Pressure fluctuation intensity is strongest near the tongue and shows irregular distribution in the pump casing. Pressure fluctuation is distributed symmetrically at the cross-section of the volute casing because the volute can eliminate the rotational movement of the liquid discharged from the impeller. Blade passing frequency and its multiples indicate the dominant frequency of the monitoring points within the volute, and the low-frequency pulsation, particularly in the shaft component, increases when it operates at off-design condition, particularly with a small flow rate. The reason is that the vortex wave is enhanced at the off-design condition, which has an effect on the axle and is presented in the shaft component in the frequency domain.

  19. Integrative Biological Chemistry Program Includes The Use Of Informatics Tools, GIS And SAS Software Applications.

    Science.gov (United States)

    D'Souza, Malcolm J; Kashmar, Richard J; Hurst, Kent; Fiedler, Frank; Gross, Catherine E; Deol, Jasbir K; Wilson, Alora

    Wesley College is a private, primarily undergraduate minority-serving institution located in the historic district of Dover, Delaware (DE). The College recently revised its baccalaureate biological chemistry program requirements to include a one-semester Physical Chemistry for the Life Sciences course and project-based experiential learning courses using instrumentation, data-collection, data-storage, statistical-modeling analysis, visualization, and computational techniques. In this revised curriculum, students begin with a traditional set of biology, chemistry, physics, and mathematics major core-requirements, a geographic information systems (GIS) course, a choice of an instrumental analysis course or a statistical analysis systems (SAS) programming course, and then, students can add major-electives that further add depth and value to their future post-graduate specialty areas. Open-sourced georeferenced census, health and health disparity data were coupled with GIS and SAS tools, in a public health surveillance system project, based on US county zip-codes, to develop use-cases for chronic adult obesity where income, poverty status, health insurance coverage, education, and age were categorical variables. Across the 48 contiguous states, obesity rates are found to be directly proportional to high poverty and inversely proportional to median income and educational achievement. For the State of Delaware, age and educational attainment were found to be limiting obesity risk-factors in its adult population. Furthermore, the 2004-2010 obesity trends showed that for two of the less densely populated Delaware counties; Sussex and Kent, the rates of adult obesity were found to be progressing at much higher proportions when compared to the national average.

  20. NUMERICAL SIMULATION OF ATTENUATION OF LOVE-TYPE CHANNEL WAVESIN VISCOELASTIC MEDIA~

    Institute of Scientific and Technical Information of China (English)

    ChengJiulong; LiLi; LiuTianfang; LiDechun

    1996-01-01

    Proceeding from wave equations, the paper strictly deduced the dispersion relation equation of Love-type channel waves in Standard Linear Solid model. The equation is a complex one with its real part signifying the dispersion characteristics of the channel wave while the imaginary part, the attenuation characteristics. In calculating the attenuation value, the author has set up a mathematical model of a horizontal symmetric sequence (a three layer sequence of rock-coal-rock), given out some physical parameters, and adopted the dichotomy method that is more often used inroot resolving of an equation. The calculation indicates that the influence of nonelastic absorption on the attenuation of the propagation of channel wave varies with thefrequency. In the frequency band of the Airy phase, the attenuation increases steeplike, which is unfavorable for the channel wave seismic prospecting. The study ofchannel wave attenuation has provided a theoretical basis for the compensation of attenuation.

  1. Body Wave Crustal Attenuation Characteristics in the Garhwal Himalaya, India

    Science.gov (United States)

    Negi, Sanjay S.; Paul, Ajay; Joshi, Anand; Kamal

    2015-06-01

    We estimate frequency-dependent attenuation of P and S waves in Garhwal Himalaya using the extended coda normalization method for the central frequencies 1.5, 2, 3, 4, 6, 8, 10, 12, and 16 Hz, with earthquake hypocentral distance ranging from 27 to 200 km. Forty well-located local earthquake waveforms were used to study the seismic attenuation characteristics of the Garhwal Himalaya, India, as recorded by eight stations operated by Wadia Institute of Himalayan Geology, Dehradun, India, from 2007 to 2012. We find frequency-dependent P and S wave quality factors as defined by the relations Q P = 56 ± 8 f 0.91±0.002 and Q S = 151 ± 8 f 0.84±0.002 by fitting a power-law frequency dependence model for the estimated values over the whole region. Both the Q P and Q S values indicate strong attenuation in the crust of Garhwal Himalaya. The ratio of Q S/ Q P > 1 obtained for the entire analyzed frequency range suggests that the scattering loss is due to a random and high degree of heterogeneities in the earth medium, playing an important role in seismic wave attenuation in the Himalayan crust.

  2. Proteomic analysis of cellular response induced by boron neutron capture reaction in human squamous cell carcinoma SAS cells.

    Science.gov (United States)

    Sato, Akira; Itoh, Tasuku; Imamichi, Shoji; Kikuhara, Sota; Fujimori, Hiroaki; Hirai, Takahisa; Saito, Soichiro; Sakurai, Yoshinori; Tanaka, Hiroki; Nakamura, Hiroyuki; Suzuki, Minoru; Murakami, Yasufumi; Baiseitov, Diaz; Berikkhanova, Kulzhan; Zhumadilov, Zhaxybay; Imahori, Yoshio; Itami, Jun; Ono, Koji; Masunaga, Shinichiro; Masutani, Mitsuko

    2015-12-01

    To understand the mechanism of cell death induced by boron neutron capture reaction (BNCR), we performed proteome analyses of human squamous tumor SAS cells after BNCR. Cells were irradiated with thermal neutron beam at KUR after incubation under boronophenylalanine (BPA)(+) and BPA(-) conditions. BNCR mainly induced typical apoptosis in SAS cells 24h post-irradiation. Proteomic analysis in SAS cells suggested that proteins functioning in endoplasmic reticulum, DNA repair, and RNA processing showed dynamic changes at early phase after BNCR and could be involved in the regulation of cellular response to BNCR. We found that the BNCR induces fragments of endoplasmic reticulum-localized lymphoid-restricted protein (LRMP). The fragmentation of LRMP was also observed in the rat tumor graft model 20 hours after BNCT treatment carried out at the National Nuclear Center of the Republic of Kazakhstan. These data suggest that dynamic changes of LRMP could be involved during cellular response to BNCR.

  3. First level seismic microzonation map of Chennai city – a GIS approach

    Directory of Open Access Journals (Sweden)

    G. P. Ganapathy

    2011-02-01

    Full Text Available Chennai city is the fourth largest metropolis in India, is the focus of economic, social and cultural development and it is the capital of the State of Tamil Nadu. The city has a multi-dimensional growth in development of its infrastructures and population. The area of Chennai has experienced moderate earthquakes in the historical past. Also the Bureau of Indian Standard upgraded the seismic status of Chennai from Low Seismic Hazard (Zone II to Moderate Seismic Hazard (Zone III–(BIS: 1893 (2001. In this connection, a first level seismic microzonation map of Chennai city has been produced with a GIS platform using the themes, viz, Peak Ground Acceleration (PGA, Shear wave velocity at 3 m, Geology, Ground water fluctuation and bed rock depth. The near potential seismic sources were identified from the remote-sensing study and seismo-tectonic details from published literatures. The peak ground acceleration for these seismic sources were estimated based on the attenuation relationship and the maximum PGA for Chennai is 0.176 g. The groundwater fluctuation of the city varies from 0–4 m below ground level. The depth to bedrock configuration shows trough and ridges in the bedrock topography all over the city. The seismic microzonation analysis involved grid datasets (the discrete datasets from different themes were converted to grids to compute the final seismic hazard grid through integration and weightage analysis of the source themes. The Chennai city has been classified into three broad zones, viz, High, Moderate and Low Seismic Hazard. The High seismic Hazard concentrated in a few places in the western central part of the city. The moderate hazard areas are oriented in NW-SE direction in the Western part. The southern and eastern part will have low seismic hazard. The result of the study may be used as first-hand information in selecting the appropriate earthquake resistant features in designing the forthcoming new buildings against seismic

  4. First level seismic microzonation map of Chennai city - a GIS approach

    Science.gov (United States)

    Ganapathy, G. P.

    2011-02-01

    Chennai city is the fourth largest metropolis in India, is the focus of economic, social and cultural development and it is the capital of the State of Tamil Nadu. The city has a multi-dimensional growth in development of its infrastructures and population. The area of Chennai has experienced moderate earthquakes in the historical past. Also the Bureau of Indian Standard upgraded the seismic status of Chennai from Low Seismic Hazard (Zone II) to Moderate Seismic Hazard (Zone III)-(BIS: 1893 (2001)). In this connection, a first level seismic microzonation map of Chennai city has been produced with a GIS platform using the themes, viz, Peak Ground Acceleration (PGA), Shear wave velocity at 3 m, Geology, Ground water fluctuation and bed rock depth. The near potential seismic sources were identified from the remote-sensing study and seismo-tectonic details from published literatures. The peak ground acceleration for these seismic sources were estimated based on the attenuation relationship and the maximum PGA for Chennai is 0.176 g. The groundwater fluctuation of the city varies from 0-4 m below ground level. The depth to bedrock configuration shows trough and ridges in the bedrock topography all over the city. The seismic microzonation analysis involved grid datasets (the discrete datasets from different themes were converted to grids) to compute the final seismic hazard grid through integration and weightage analysis of the source themes. The Chennai city has been classified into three broad zones, viz, High, Moderate and Low Seismic Hazard. The High seismic Hazard concentrated in a few places in the western central part of the city. The moderate hazard areas are oriented in NW-SE direction in the Western part. The southern and eastern part will have low seismic hazard. The result of the study may be used as first-hand information in selecting the appropriate earthquake resistant features in designing the forthcoming new buildings against seismic ground motion of the

  5. Physicochemical properties and oral bioavailability of amorphous atorvastatin hemi-calcium using spray-drying and SAS process.

    Science.gov (United States)

    Kim, Jeong-Soo; Kim, Min-Soo; Park, Hee Jun; Jin, Shun-Ji; Lee, Sibeum; Hwang, Sung-Joo

    2008-07-09

    The objective of the study was to prepare amorphous atorvastatin hemi-calcium using spray-drying and supercritical antisolvent (SAS) process and evaluate its physicochemical properties and oral bioavailability. Atorvastatin hemi-calcium trihydrate was transformed to anhydrous amorphous form by spray-drying and SAS process. With the SAS process, the mean particle size and the specific surface area of amorphous atorvastatin were drastically changed to 68.7+/-15.8nm, 120.35+/-1.40m2/g and 95.7+/-12.2nm, 79.78+/-0.93m2/g from an acetone solution and a tetrahydrofuran solution, respectively and appeared to be associated with better performance in apparent solubility, dissolution and pharmacokinetic studies, compared with unprocessed crystalline atorvastatin. Oral AUC0-8h values in SD rats for crystalline and amorphous atorvastatin were as follow: 1121.4+/-212.0ngh/mL for crystalline atorvastatin, 3249.5+/-406.4ngh/mL and 3016.1+/-200.3ngh/mL for amorphous atorvastatin from an acetone solution and a tetrahydrofuran solution with SAS process, 2227.8+/-274.5 and 2099.9+/-339.2ngh/mL for amorphous atorvastatin from acetone and tetrahydrofuran with spray-drying. The AUCs of all amorphous atorvastatin significantly increased (PSAS process exhibits better bioavailability than spray-drying because of particle size reduction with narrow particle size distribution. It was concluded that physicochemical properties and bioavailability of crystalline atorvastatin could be improved by physical modification such as particle size reduction and generation of amorphous state using spray-drying and SAS process. Further, SAS process was a powerful methodology for improving the physicochemical properties and bioavailability of atorvastatin.

  6. Shallow Water Body Data Processing Based on the Seismic Oceanography

    Institute of Scientific and Technical Information of China (English)

    LIU Huaishan; HU Yi; YIN Yanxin; WANG Linfei; TONG Siyou; MA Hai

    2013-01-01

    Physical properties of sea water,such as salinity,temperature,density and acoustic velocity,could be demarcated through degradation of energy caused by water absorption,attenuation and other factors.To overcome the challenging difficulties in the quick monitoring of these physical properties,we have explored the high resolution marine seismic survey to instantly characterize them.Based on the unique wavefield propagating in the sea water,we have developed a new approach to suppress the noise caused by the shallow sea water disturbance and obtain useful information for estimating the sea water structure.This approach improves seismic data with high signal-to-noise ratio and resolution.The seismic reflection imaging can map the sea water structure acoustically.Combined with the knowledge of local water body structure profile over years,the instant model for predicting the sea water properties could be built using the seismic data acquired from the specially designed high precision marine seismic acquisition.This model can also be updated with instant observation and the complete data processing system.The present study has the potential value to many applications,such as 3D sea water monitoring,engineering evaluation,geological disaster assessment and environmental assessment.

  7. Europa's small impactor flux and seismic detection predictions

    Science.gov (United States)

    Tsuji, Daisuke; Teanby, Nicholas A.

    2016-10-01

    Europa is an attractive target for future lander missions due to its dynamic surface and potentially habitable sub-surface environment. Seismology has the potential to provide powerful new constraints on the internal structure using natural sources such as faults or meteorite impacts. Here we predict how many meteorite impacts are likely to be detected using a single seismic station on Europa to inform future mission planning efforts. To this end, we derive: (1) the current small impactor flux on Europa from Jupiter impact rate observations and models; (2) a crater diameter versus impactor energy scaling relation for icy moons by merging previous experiments and simulations; and (3) scaling relations for seismic signal amplitudes as a function of distance from the impact site for a given crater size, based on analogue explosive data obtained on Earth's ice sheets. Finally, seismic amplitudes are compared to predicted noise levels and seismometer performance to determine detection rates. We predict detection of 0.002-20 small local impacts per year based on P-waves travelling directly through the ice crust. Larger regional and global-scale impact events, detected through mantle-refracted waves, are predicted to be extremely rare (10-8-1 detections per year), so are unlikely to be detected by a short duration mission. Estimated ranges include uncertainties from internal seismic attenuation, impactor flux, and seismic amplitude scaling. Internal attenuation is the most significant unknown and produces extreme uncertainties in the mantle-refracted P-wave amplitudes. Our nominal best-guess attenuation model predicts 0.002-5 local direct P detections and 6 × 10-6-0.2 mantle-refracted detections per year. Given that a plausible Europa landed mission will only last around 30 days, we conclude that impacts should not be relied upon for a seismic exploration of Europa. For future seismic exploration, faulting due to stresses in the rigid outer ice shell is likely to be a

  8. Nonstructural seismic restraint guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.M.; Czapinski, R.H.; Firneno, M.J.; Feemster, H.C.; Fornaciari, N.R.; Hillaire, R.G.; Kinzel, R.L.; Kirk, D.; McMahon, T.T.

    1993-08-01

    The Nonstructural Seismic Restraint Guidelines provide general information about how to secure or restrain items (such as material, equipment, furniture, and tools) in order to prevent injury and property, environmental, or programmatic damage during or following an earthquake. All SNL sites may experience earthquakes of magnitude 6.0 or higher on the Richter scale. Therefore, these guidelines are written for all SNL sites.

  9. Understanding induced seismicity

    NARCIS (Netherlands)

    Elsworth, Derek; Spiers, Christopher J.; Niemeijer, Andre R.

    2016-01-01

    Fluid injection–induced seismicity has become increasingly widespread in oil- and gas-producing areas of the United States (1–3) and western Canada. It has shelved deep geothermal energy projects in Switzerland and the United States (4), and its effects are especially acute in Oklahoma, where seismi

  10. Understanding induced seismicity

    NARCIS (Netherlands)

    Elsworth, Derek; Spiers, Christopher J.; Niemeijer, Andre R.

    2016-01-01

    Fluid injection–induced seismicity has become increasingly widespread in oil- and gas-producing areas of the United States (1–3) and western Canada. It has shelved deep geothermal energy projects in Switzerland and the United States (4), and its effects are especially acute in Oklahoma, where

  11. Mobile seismic exploration

    Science.gov (United States)

    Dräbenstedt, A.; Cao, X.; Polom, U.; Pätzold, F.; Zeller, T.; Hecker, P.; Seyfried, V.; Rembe, C.

    2016-06-01

    Laser-Doppler-Vibrometry (LDV) is an established technique to measure vibrations in technical systems with picometer vibration-amplitude resolution. Especially good sensitivity and resolution can be achieved at an infrared wavelength of 1550 nm. High-resolution vibration measurements are possible over more than 100 m distance. This advancement of the LDV technique enables new applications. The detection of seismic waves is an application which has not been investigated so far because seismic waves outside laboratory scales are usually analyzed at low frequencies between approximately 1 Hz and 250 Hz and require velocity resolutions in the range below 1 nm/s/√Hz. Thermal displacements and air turbulence have critical influences to LDV measurements at this low-frequency range leading to noise levels of several 100 nm/√Hz. Commonly seismic waves are measured with highly sensitive inertial sensors (geophones or Micro Electro-Mechanical Sensors (MEMS)). Approaching a laser geophone based on LDV technique is the topic of this paper. We have assembled an actively vibration-isolated optical table in a minivan which provides a hole in its underbody. The laser-beam of an infrared LDV assembled on the optical table impinges the ground below the car through the hole. A reference geophone has detected remaining vibrations on the table. We present the results from the first successful experimental demonstration of contactless detection of seismic waves from a movable vehicle with a LDV as laser geophone.

  12. Mobile seismic exploration

    Energy Technology Data Exchange (ETDEWEB)

    Dräbenstedt, A., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de; Seyfried, V. [Research & Development, Polytec GmbH, Waldbronn (Germany); Cao, X.; Rembe, C., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Institute of Electrical Information Technology, TU Clausthal, Clausthal-Zellerfeld (Germany); Polom, U., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Leibniz Institute of Applied Geophysics, Hannover (Germany); Pätzold, F.; Hecker, P. [Institute of Flight Guidance, TU Braunschweig, Braunschweig (Germany); Zeller, T. [Clausthaler Umwelttechnik Institut CUTEC, Clausthal-Zellerfeld (Germany)

    2016-06-28

    Laser-Doppler-Vibrometry (LDV) is an established technique to measure vibrations in technical systems with picometer vibration-amplitude resolution. Especially good sensitivity and resolution can be achieved at an infrared wavelength of 1550 nm. High-resolution vibration measurements are possible over more than 100 m distance. This advancement of the LDV technique enables new applications. The detection of seismic waves is an application which has not been investigated so far because seismic waves outside laboratory scales are usually analyzed at low frequencies between approximately 1 Hz and 250 Hz and require velocity resolutions in the range below 1 nm/s/√Hz. Thermal displacements and air turbulence have critical influences to LDV measurements at this low-frequency range leading to noise levels of several 100 nm/√Hz. Commonly seismic waves are measured with highly sensitive inertial sensors (geophones or Micro Electro-Mechanical Sensors (MEMS)). Approaching a laser geophone based on LDV technique is the topic of this paper. We have assembled an actively vibration-isolated optical table in a minivan which provides a hole in its underbody. The laser-beam of an infrared LDV assembled on the optical table impinges the ground below the car through the hole. A reference geophone has detected remaining vibrations on the table. We present the results from the first successful experimental demonstration of contactless detection of seismic waves from a movable vehicle with a LDV as laser geophone.

  13. Geophysics and Seismic Hazard Reduction

    Institute of Scientific and Technical Information of China (English)

    YuGuihua; ZhouYuanze; YuSheng

    2003-01-01

    The earthquake is a natural phenomenon, which often brings serious hazard to the human life and material possession. It is a physical process of releasing interior energy of the earth, which is caused by interior and outer forces in special tectonic environment in the earth, especially within the lithosphere. The earthquake only causes casualty and loss in the place where people inhabit. Seismic hazard reduction is composed of four parts as seismic prediction, hazard prevention and seismic engineering, seismic response and seismic rescuing, and rebuilding.

  14. ARP: Automatic rapid processing for the generation of problem dependent SAS2H/ORIGEN-s cross section libraries

    Energy Technology Data Exchange (ETDEWEB)

    Leal, L.C.; Hermann, O.W.; Bowman, S.M.; Parks, C.V.

    1998-04-01

    In this report, a methodology is described which serves as an alternative to the SAS2H path of the SCALE system to generate cross sections for point-depletion calculations with the ORIGEN-S code. ARP, Automatic Rapid Processing, is an algorithm that allows the generation of cross-section libraries suitable to the ORIGEN-S code by interpolation over pregenerated SAS2H libraries. The interpolations are carried out on the following variables: burnup, enrichment, and water density. The adequacy of the methodology is evaluated by comparing measured and computed spent fuel isotopic compositions for PWR and BWR systems.

  15. A leave-one-out cross-validation SAS macro for the identification of markers associated with survival.

    Science.gov (United States)

    Rushing, Christel; Bulusu, Anuradha; Hurwitz, Herbert I; Nixon, Andrew B; Pang, Herbert

    2015-02-01

    A proper internal validation is necessary for the development of a reliable and reproducible prognostic model for external validation. Variable selection is an important step for building prognostic models. However, not many existing approaches couple the ability to specify the number of covariates in the model with a cross-validation algorithm. We describe a user-friendly SAS macro that implements a score selection method and a leave-one-out cross-validation approach. We discuss the method and applications behind this algorithm, as well as details of the SAS macro.

  16. Frequency and distance changes in the apparent P-wave radiation pattern: effects of seismic wave scattering in the crust inferred from dense seismic observations and numerical simulations

    Science.gov (United States)

    Kobayashi, Manabu; Takemura, Shunsuke; Yoshimoto, Kazuo

    2015-09-01

    Frequency and distance changes in the apparent P-wave radiation pattern (0.75-12 Hz) are investigated using velocity seismograms of shallow strike-slip earthquakes occurring in Chugoku region, southwestern Japan. Data from a dense seismic monitoring network revealed that the four-lobe apparent P-wave radiation pattern was gradually distorted with increasing frequency and propagation distance. Observed features suggest that seismic wave scattering due to small-scale velocity heterogeneity in the crust may be a major cause of this distortion. The effects of seismic wave scattering on apparent P-wave radiation pattern were investigated via 3-D finite difference simulation of seismic wave propagation. Our simulations demonstrated that the scattering of seismic waves modified the apparent P-wave radiation pattern from the original four-lobe shape, and that the small-scale velocity heterogeneity, characterized by the von Kármán-type power spectral density function with correlation distance of 1 km, root-mean-square value of 0.03 and decay rate parameter of 0.5, might be adequate for modelling crustal heterogeneity in the target region. It was also found that the scattering attenuation of P wave expected from this heterogeneity is significantly smaller than the apparent P-wave attenuation and S-wave scattering attenuation reported by Multiple Lapse Time Window Analysis of previous studies in Japan. These results might imply that scattering attenuation is not the dominant mechanism of P-wave attenuation in the crust of Chugoku region.

  17. Seismic Prediction While Drilling (SPWD): Seismic exploration ahead of the drill bit using phased array sources

    Science.gov (United States)

    Jaksch, Katrin; Giese, Rüdiger; Kopf, Matthias

    2010-05-01

    maximize the energy of the seismic source in order to reach a sufficient exploration range. The next step for focusing is to use the method of phased array. Dependent of the seismic wave velocities of the surrounding rock, the distance of the actuators to each other and the used frequencies the signal phases for each actuator can be determined. Since one year several measurements with the prototype have been realized under defined conditions at a test site in a mine. The test site consists of a rock block surrounded from three galleries with a dimension of about 100 by 200 meters. For testing the prototype two horizontal boreholes were drilled. They are directed to one of the gallery to get a strong reflector. The quality of the data of the borehole seismics in amplitude and frequency spectra show overall a good signal-to-noise ratio and correlate strongly with the fracture density along the borehole and are associated with a lower signal-to-noise ratio. Additionally, the geophones of the prototype show reflections from ahead and rearward in the seismic data. In particular, the reflections from the gallery ahead are used for the calibration of focusing. The direct seismic wave field indicates distinct compression and shear waves. The analysis of several seismic measurements with a focus on the direct seismic waves shows that the phased array technology explicit can influence the directional characteristics of the radiated seimic waves. The amplitudes of the seismic waves can be enhanced up to three times more in the desired direction and simultaneously be attenuated in the reverse direction. A major step for the directional investigation in boreholes has accomplished. But the focusing of the seismic waves has to be improved to maximize the energy in the desired direction in more measurements by calibrating the initiating seismic signals of the sources. A next step this year is the development of a wireline prototype for application in vertical boreholes with depths not

  18. SAS-4 is recruited to a dynamic structure in newly forming centrioles that is stabilized by the gamma-tubulin-mediated addition of centriolar microtubules.

    Science.gov (United States)

    Dammermann, Alexander; Maddox, Paul S; Desai, Arshad; Oegema, Karen

    2008-02-25

    Centrioles are surrounded by pericentriolar material (PCM), which is proposed to promote new centriole assembly by concentrating gamma-tubulin. Here, we quantitatively monitor new centriole assembly in living Caenorhabditis elegans embryos, focusing on the conserved components SAS-4 and SAS-6. We show that SAS-4 and SAS-6 are coordinately recruited to the site of new centriole assembly and reach their maximum levels during S phase. Centriolar SAS-6 is subsequently reduced by a mechanism intrinsic to the early assembly pathway that does not require progression into mitosis. Centriolar SAS-4 remains in dynamic equilibrium with the cytoplasmic pool until late prophase, when it is stably incorporated in a step that requires gamma-tubulin and microtubule assembly. These results indicate that gamma-tubulin in the PCM stabilizes the nascent daughter centriole by promoting microtubule addition to its outer wall. Such a mechanism may help restrict new centriole assembly to the vicinity of preexisting parent centrioles that recruit PCM.

  19. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  20. Sensitivity of seismic hazard evaluations to uncertainties determined from seismic source characterization

    Science.gov (United States)

    Tavakoli, Behrooz

    The sensitivity and overall uncertainty in peak ground acceleration (PGA)estimates have been calculated for the city of Tabriz, northwestern Iran byusing a specific randomized blocks design. Eight seismic hazard models andparameters with randomly selected uncertainties at two levels have beenconsidered and then a linear model between predicted PGA at a givenprobability level and the uncertainties has been performed. The inputmodels and parameters are those related to the attenuation, magnituderupture-length and recurrence relationships with their uncertainties.Application of this procedure to the studied area indicates that effects ofthe simultaneous variation of all eight input models and parameters on thesensitivity of the seismic hazard can be investigated with a decreasingnumber of computations for all possible combinations at a fixed annualprobability. The results show that the choice of a mathematical model ofthe source mechanism, attenuation relationships and the definition ofseismic parameters are most critical in estimating the sensitivity of seismichazard evaluation, in particular at low levels of probability of exceedance.The overall uncertainty in the expected PGA for an annual probability of0.0021 (10% exceedence in 50 yr) is expressed by a coefficient ofvariation (CV) of about 34% at 68% confidence level for a distance ofabout 5km from the field of the major faults. The CV will decrease withincreasing site-source distance and remains constant, CV = 15%, fordistances larger than 15 km. Finally, treating alternative models on theoverall uncertainty are investigated by additional outliers in input decision.

  1. Planetary Ices Attenuation Properties

    Science.gov (United States)

    McCarthy, Christine; Castillo-Rogez, Julie C.

    In this chapter, we review the topic of energy dissipation in the context of icy satellites experiencing tidal forcing. We describe the physics of mechanical dissipation, also known as attenuation, in polycrystalline ice and discuss the history of laboratory methods used to measure and understand it. Because many factors - such as microstructure, composition and defect state - can influence rheological behavior, we review what is known about the mechanisms responsible for attenuation in ice and what can be inferred from the properties of rocks, metals and ceramics. Since attenuation measured in the laboratory must be carefully scaled to geologic time and to planetary conditions in order to provide realistic extrapolation, we discuss various mechanical models that have been used, with varying degrees of success, to describe attenuation as a function of forcing frequency and temperature. We review the literature in which these models have been used to describe dissipation in the moons of Jupiter and Saturn. Finally, we address gaps in our present knowledge of planetary ice attenuation and provide suggestions for future inquiry.

  2. Design of a Road Friendly SAS System for Heavy-Duty Vehicles Based on a Fuzzy-Hybrid-ADD and GH-Control Strategy

    OpenAIRE

    Jing Zhao; Pak Kin Wong; Zhengchao Xie; Xinbo Ma; Caiyang Wei

    2016-01-01

    Semiactive suspension (SAS) system has been widely used for its outstanding performance in offering competent ride quality, road holding, and handling capacity. However, the road friendliness is also one of the crucial factors that should be attached in the design of the SAS system for heavy-duty vehicles. In this study, a fuzzy controlled hybrid-acceleration driven damper (ADD) and ground hook- (GH-) control strategy is proposed for SAS system of heavy-duty vehicles. Firstly, a quarter-vehic...

  3. Review of seismicity and ground motion studies related to development of seismic design at SRS

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States); Acree, J.R. [Westinghouse Environmental and Geotechnical Services, Inc., Columbia, SC (United States)

    1992-08-01

    The NRC response spectra developed in Reg. Guide 1.60 is being used in the studies related to restarting of the existing Savannah River Site (SRS) reactors. Because it envelopes all the other site specific spectra which have been developed for SRS, it provides significant conservatism in the design and analysis of the reactor systems for ground motions of this value or with these probability levels. This spectral shape is also the shape used for the design of the recently licensed Vogtle Nuclear Station, located south of the Savannah River from the SRS. This report provides a summary of the data base used to develop the design basis earthquake. This includes the seismicity, rates of occurrence, magnitudes, and attenuation relationships. A summary is provided for the studies performed and methodologies used to establish the design basis earthquake for SRS. The ground motion response spectra developed from the various studies are also summarized. The seismic hazard and PGA`s developed for other critical facilities in the region are discussed, and the SRS seismic instrumentation is presented. The programs for resolving outstanding issues are discussed and conclusions are presented.

  4. Seismic Hazard Assessment for a Characteristic Earthquake Scenario: Probabilistic-Deterministic Method

    Science.gov (United States)

    mouloud, Hamidatou

    2016-04-01

    The objective of this paper is to analyze the seismic activity and the statistical treatment of seismicity catalog the Constantine region between 1357 and 2014 with 7007 seismic event. Our research is a contribution to improving the seismic risk management by evaluating the seismic hazard in the North-East Algeria. In the present study, Earthquake hazard maps for the Constantine region are calculated. Probabilistic seismic hazard analysis (PSHA) is classically performed through the Cornell approach by using a uniform earthquake distribution over the source area and a given magnitude range. This study aims at extending the PSHA approach to the case of a characteristic earthquake scenario associated with an active fault. The approach integrates PSHA with a high-frequency deterministic technique for the prediction of peak and spectral ground motion parameters in a characteristic earthquake. The method is based on the site-dependent evaluation of the probability of exceedance for the chosen strong-motion parameter. We proposed five sismotectonique zones. Four steps are necessary: (i) identification of potential sources of future earthquakes, (ii) assessment of their geological, geophysical and geometric, (iii) identification of the attenuation pattern of seismic motion, (iv) calculation of the hazard at a site and finally (v) hazard mapping for a region. In this study, the procedure of the earthquake hazard evaluation recently developed by Kijko and Sellevoll (1992) is used to estimate seismic hazard parameters in the northern part of Algeria.

  5. Regional Analysis of Lg Attenuation: Comparison of 1-D Methods in Northern California and Application to the Yellow Sea/Korean Peninsula

    Science.gov (United States)

    2007-09-01

    2002). Quantitative Seismology . Sausalito, Calififornia: University Science Books. Aki, K. (1980). Attenuation of shear-waves in the lithosphere for... Italy , Geophys. Res. Lett. 34: L10308. Xie, J., R. Gok, J. Ni, and Y. Aoki, (2004). Lateral variations of crustal seismic attenuation along the

  6. Frequency Dependent Attenuation Revisited

    CERN Document Server

    Richard, Kowar; Xavier, Bonnefond

    2009-01-01

    The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power laws and and the thermo-viscous equation. The lack of causality of standard models in the parameter range relevant for photoacoustic imaging requires to derive novel equations. The main ingredients for deriving causal equations are the Kramers-Kronig relation and the mathematical concept of linear system theory. The theoretical results of this work are underpined by numerical experiments.

  7. 3D Attenuation Tomography of the Volcanic Island of Tenerife (Canary Islands)

    Science.gov (United States)

    Prudencio, J.; Ibáñez, J. M.; Del Pezzo, E.; Martí, J.; García-Yeguas, A.; De Siena, L.

    2015-09-01

    This paper shows a new multidisciplinary interpretation approach to the internal structure of Tenerife Island. The central core of this work is the determination of the three-dimensional attenuation structure of the region using P-waves and the coda normalization method. This study has been performed using 45,303 seismograms recorded at 85 seismic stations from an active experiment (air gun shots) conducted in January 2007. The interpretation of these new results is done combining the new images with previous studies performed in the area such as seismic velocity tomography, magnetic structure, magnetotelluric surveys or gravimetric models. Our new 3D images indicate the presence of seismic attenuation contrasts, with areas of high and low seismic attenuation patterns. High seismic attenuation zones are observed both in shallow and in deeper areas. The shallowest area of Las Cañadas caldera complex (1-3 km thick) is dominated by high attenuation behavior, and it is interpreted as the combined effect of sedimentary and volcanoclastic deposits, multifracture systems and the presence of shallow aquifers. At the same time, the deeper analyzed area, more than 8 km below sea level, is dominated by a high attenuation pattern, and it is interpreted as the consequence of the effect of high-temperature rocks in the crustal-mantle boundary. This interpretation is compatible and confirmed by previous models that indicate the presence of underplating magma in this region. On the contrary, some low attenuation bodies and structures have been identified at different depths. A deep low attenuation central body is interpreted as the original central structure associated with the early stage of Tenerife Island. At shallower depths, some low attenuation bodies are compatible with old intermediate magmatic chambers postulated by petrological studies. Finally, in the north of the island (La Orotava valley) we can interpret the low attenuation structure as the headwall of this valley

  8. Revisiting Earth's radial seismic structure using a Bayesian neural network approach

    NARCIS (Netherlands)

    de Wit, R.W.L.

    2015-01-01

    The gross features of seismic observations can be explained by relatively simple spherically symmetric (1-D) models of wave velocities, density and attenuation, which describe the Earth's average(radial) structure. 1-D earth models are often used as a reference for studies on Earth's thermo-chemical

  9. Revisiting Earth's radial seismic structure using a Bayesian neural network approach

    NARCIS (Netherlands)

    de Wit, R.W.L.

    2015-01-01

    The gross features of seismic observations can be explained by relatively simple spherically symmetric (1-D) models of wave velocities, density and attenuation, which describe the Earth's average(radial) structure. 1-D earth models are often used as a reference for studies on Earth's thermo-chemical

  10. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice.

    Science.gov (United States)

    Yang, Yilong; Qian, Mengying; Yi, Shaoqiong; Liu, Shuling; Li, Bing; Yu, Rui; Guo, Qiang; Zhang, Xiaopeng; Yu, Changming; Li, Jianmin; Xu, Junjie; Chen, Wei

    2016-01-01

    Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections.

  11. SAS Code for Calculating Intraclass Correlation Coefficients and Effect Size Benchmarks for Site-Randomized Education Experiments

    Science.gov (United States)

    Brandon, Paul R.; Harrison, George M.; Lawton, Brian E.

    2013-01-01

    When evaluators plan site-randomized experiments, they must conduct the appropriate statistical power analyses. These analyses are most likely to be valid when they are based on data from the jurisdictions in which the studies are to be conducted. In this method note, we provide software code, in the form of a SAS macro, for producing statistical…

  12. Development and validation of the self-acceptance scale for persons with early blindness: the SAS-EB.

    Science.gov (United States)

    Morgado, Fabiane Frota da Rocha; Campana, Angela Nogueira Neves Betanho; Tavares, Maria da Consolação Gomes Cunha Fernandes

    2014-01-01

    Investigations of self-acceptance are critical to understanding the development and maintenance of psychological health. However, valid and reliable instruments for measuring self-acceptance in persons with early blindness have yet to be developed. The current research describes three studies designed to develop and validate the Self-acceptance Scale for Persons with Early Blindness (SAS-EB). In Study 1, we developed the initial item pool. Thirty-three items were generated, based on data from specialized literature and from 2 focus groups. Items were organized in a three-factor structure, theoretically predicted for SAS-EB - (1) body acceptance, (2) self-protection from social stigmas, and (3) feeling and believing in one's capacities. In Study 2, information obtained from a panel of 9 experts and 22 persons with early blindness representing the target population was used to refine the initial item pool, generating a new pool of 27 items. In Study 3, 318 persons with early blindness (141 women and 177 men), between 18 and 60 years of age (M = 37.74 years, SD = 12.37) answered the new pool of 27 items. After the elimination of 9 items using confirmatory factor analysis, we confirmed the theoretical three-factor structure of the SAS-EB. Study 3 also provided support for the scale's internal consistency and construct validity. Finally, the psychometric properties of the SAS-EB, its utility, and its limitations are discussed along with considerations for future research.

  13. An essential role of the basal body protein SAS-6 in Plasmodium male gamete development and malaria transmission.

    Science.gov (United States)

    Marques, Sara R; Ramakrishnan, Chandra; Carzaniga, Raffaella; Blagborough, Andrew M; Delves, Michael J; Talman, Arthur M; Sinden, Robert E

    2015-02-01

    Gametocytes are the sole Plasmodium parasite stages that infect mosquitoes; therefore development of functional gametes is required for malaria transmission. Flagellum assembly of the Plasmodium male gamete differs from that of most other eukaryotes in that it is intracytoplasmic but retains a key conserved feature: axonemes assemble from basal bodies. The centriole/basal body protein SAS-6 normally regulates assembly and duplication of these organelles and its depletion causes severe flagellar/ciliary abnormalities in a diverse array of eukaryotes. Since basal body and flagellum assembly are intimately coupled to male gamete development in Plasmodium, we hypothesized that SAS-6 disruption may cause gametogenesis defects and perturb transmission. We show that Plasmodium berghei sas6 knockouts display severely abnormal male gametogenesis presenting reduced basal body numbers, axonemal assembly defects and abnormal nuclear allocation. The defects in gametogenesis reduce fertilization and render Pbsas6 knockouts less infectious to mosquitoes. Additionally, we show that lack of Pbsas6 blocks transmission from mosquito to vertebrate host, revealing an additional yet undefined role in ookinete to sporulating oocysts transition. These findings underscore the vulnerability of the basal body/SAS-6 to malaria transmission blocking interventions.

  14. Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

    Directory of Open Access Journals (Sweden)

    Brom Aleksander

    2015-10-01

    Full Text Available The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

  15. REGULATION OF SEISMIC LOAD ON BUILDINGS SEISMIC DEVICES

    Directory of Open Access Journals (Sweden)

    Kh. N. Mazhiev

    2013-01-01

    Full Text Available The issues of regulation of seismic loads on structures using kinematic supports of highstrength concrete on the impregnated coarse aggregate and seismic isolation bearings Belleville. The results of experimental studies related to the obtaining of a new coarse aggregate and construction of seismic isolation bearings. Addresses the issues of interaction forces in thehemispherical supports vibration process.

  16. Integrating SAS and GIS software to improve habitat-use estimates from radiotelemetry data

    Science.gov (United States)

    Kenow, K.P.; Wright, R.G.; Samuel, M.D.; Rasmussen, P.W.

    2001-01-01

    Radiotelemetry has been used commonly to remotely determine habitat use by a variety of wildlife species. However, habitat misclassification can occur because the true location of a radiomarked animal can only be estimated. Analytical methods that provide improved estimates of habitat use from radiotelemetry location data using a subsampling approach have been proposed previously. We developed software, based on these methods, to conduct improved habitat-use analyses. A Statistical Analysis System (SAS)-executable file generates a random subsample of points from the error distribution of an estimated animal location and formats the output into ARC/INFO-compatible coordinate and attribute files. An associated ARC/INFO Arc Macro Language (AML) creates a coverage of the random points, determines the habitat type at each random point from an existing habitat coverage, sums the number of subsample points by habitat type for each location, and outputs tile results in ASCII format. The proportion and precision of habitat types used is calculated from the subsample of points generated for each radiotelemetry location. We illustrate the method and software by analysis of radiotelemetry data for a female wild turkey (Meleagris gallopavo).

  17. Acetyltransferase SAS2 and sirtuin SIR2, respectively, control flocculation and biofilm formation in wine yeast.

    Science.gov (United States)

    Rodriguez, María E; Orozco, Helena; Cantoral, Jesús M; Matallana, Emilia; Aranda, Agustín

    2014-09-01

    Cell-to-cell and cell-to-environment interactions of microorganisms are of substantial relevance for their biotechnological use. In the yeast Saccharomyces cerevisiae, flocculation can be an advantage to clarify final liquid products after fermentation, and biofilm formation may be relevant for the encapsulation of strains of interest. The adhesion properties of wine yeast strains can be modified by the genetic manipulation of transcriptional regulatory proteins, such as histone deacetylases, and acetylases. Sirtuin SIR2 is essential for the formation of mat structures, a kind of biofilm that requires the expression of cell-wall protein FLO11 as its deletion reduces FLO11 expression, and adhesion of cells to themselves and to agar in a commercial wine strain. Deletion of acetyltransferase GCN5 leads to a similar phenotype. A naturally flocculant wine yeast strain called P2 was characterized. Its flocculation happens only during grape juice fermentation and is due to the presence of a highly transcribed version of flocculin FLO5, linked to the presence of a δ sequence in the promoter. Deletion of acetyltransferase SAS2 enhances this phenotype and maltose fermentation even more. Therefore, the manipulation of acetylation/deacetylation machinery members is a valid way to alter the interaction of industrial yeast to their environment.

  18. Design of experiment and data analysis by JMP (SAS institute) in analytical method validation.

    Science.gov (United States)

    Ye, C; Liu, J; Ren, F; Okafo, N

    2000-08-15

    Validation of an analytical method through a series of experiments demonstrates that the method is suitable for its intended purpose. Due to multi-parameters to be examined and a large number of experiments involved in validation, it is important to design the experiments scientifically so that appropriate validation parameters can be examined simultaneously to provide a sound, overall knowledge of the capabilities of the analytical method. A statistical method through design of experiment (DOE) was applied to the validation of a HPLC analytical method for the quantitation of a small molecule in drug product in terms of intermediate precision and robustness study. The data were analyzed in JMP (SAS institute) software using analyses of variance method. Confidence intervals for outcomes and control limits for individual parameters were determined. It was demonstrated that the experimental design and statistical analysis used in this study provided an efficient and systematic approach to evaluating intermediate precision and robustness for a HPLC analytical method for small molecule quantitation.

  19. The ZpiM algorithm: a method for interferometric image reconstruction in SAR/SAS.

    Science.gov (United States)

    Dias, José M B; Leitao, José M N

    2002-01-01

    This paper presents an effective algorithm for absolute phase (not simply modulo-2-pi) estimation from incomplete, noisy and modulo-2pi observations in interferometric aperture radar and sonar (InSAR/InSAS). The adopted framework is also representative of other applications such as optical interferometry, magnetic resonance imaging and diffraction tomography. The Bayesian viewpoint is adopted; the observation density is 2-pi-periodic and accounts for the interferometric pair decorrelation and system noise; the a priori probability of the absolute phase is modeled by a compound Gauss-Markov random field (CGMRF) tailored to piecewise smooth absolute phase images. We propose an iterative scheme for the computation of the maximum a posteriori probability (MAP) absolute phase estimate. Each iteration embodies a discrete optimization step (Z-step), implemented by network programming techniques and an iterative conditional modes (ICM) step (pi-step). Accordingly, the algorithm is termed ZpiM, where the letter M stands for maximization. An important contribution of the paper is the simultaneous implementation of phase unwrapping (inference of the 2pi-multiples) and smoothing (denoising of the observations). This improves considerably the accuracy of the absolute phase estimates compared to methods in which the data is low-pass filtered prior to unwrapping. A set of experimental results, comparing the proposed algorithm with alternative methods, illustrates the effectiveness of our approach.

  20. Evaluation of sleep apnea syndrome (SAS) with low field MR fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fukatsu, Hiroshi; Ando, Yoko; Ishigaki, Takeo [Nagoya Univ. (Japan). School of Medicine; Okada, Tamotsu

    1995-02-01

    Eight cases of clinically diagnosed sleep apnea syndrome (SAS) and two normal volunteers were studied with low field MR fluoroscopy in order to monitor the waking and sleeping status of the upper airway. MR fluoroscopy revealed that only the sleeping patients showed occlusions of the upper airway. This technique provided us with useful information about the level, frequency and duration of occlusion in each case. Four of the eight patients demonstrated simple retropalatal occlusion, whereas the other four demonstrated mixed retropalatal and retropalato-retroglossal occlusion. Thus long-time monitoring, which is only possible with MR fluoroscopy, is needed to appreciate the complex nature of the disease. In addition, the comfortable surroundings and low noise level provided by the low field enabled physiological study to be performed without any tranquilizers in most of the patients, which is again only possible with MR fluoroscopy. MR fluoroscopy may become a tool of great clinical value, providing much important information for disease evaluation and treatment selection. (author).

  1. SPSS and SAS procedures for estimating indirect effects in simple mediation models.

    Science.gov (United States)

    Preacher, Kristopher J; Hayes, Andrew F

    2004-11-01

    Researchers often conduct mediation analysis in order to indirectly assess the effect of a proposed cause on some outcome through a proposed mediator. The utility of mediation analysis stems from its ability to go beyond the merely descriptive to a more functional understanding of the relationships among variables. A necessary component of mediation is a statistically and practically significant indirect effect. Although mediation hypotheses are frequently explored in psychological research, formal significance tests of indirect effects are rarely conducted. After a brief overview of mediation, we argue the importance of directly testing the significance of indirect effects and provide SPSS and SAS macros that facilitate estimation of the indirect effect with a normal theory approach and a bootstrap approach to obtaining confidence intervals, as well as the traditional approach advocated by Baron and Kenny (1986). We hope that this discussion and the macros will enhance the frequency of formal mediation tests in the psychology literature. Electronic copies of these macros may be downloaded from the Psychonomic Society's Web archive at www.psychonomic.org/archive/.

  2. [Evaluation of the factorial and metric equivalence of the Sexual Assertiveness Scale (SAS) by sex].

    Science.gov (United States)

    Sierra, Juan Carlos; Santos-Iglesias, Pablo; Vallejo-Medina, Pablo

    2012-05-01

    Sexual assertiveness refers to the ability to initiate sexual activity, refuse unwanted sexual activity, and use contraceptive methods to avoid sexually transmitted diseases, developing healthy sexual behaviors. The Sexual Assertiveness Scale (SAS) assesses these three dimensions. The purpose of this study is to evaluate, using structural equation modeling and differential item functioning, the equivalence of the scale between men and women. Standard scores are also provided. A total of 4,034 participants from 21 Spanish provinces took part in the study. Quota sampling method was used. Results indicate a strict equivalent dimensionality of the Sexual Assertiveness Scale across sexes. One item was flagged by differential item functioning, although it does not affect the scale. Therefore, there is no significant bias in the scale when comparing across sexes. Standard scores show similar Initiation assertiveness scores for men and women, and higher scores on Refusal and Sexually Transmitted Disease Prevention for women. This scale can be used on men and women with sufficient psychometric guarantees.

  3. Cosmic radiation and airline pilots. Exposure patterns of Norwegian pilots flying aircraft not used by SAS

    Energy Technology Data Exchange (ETDEWEB)

    Tveten, U.

    1997-05-01

    The work which is presented in this report is part of a Norwegian epidemiological project, carried out in cooperation between Institutt for Energiteknikk (IFE), the Norwegian Cancer Registry (NCR) and the Norwegian Radiation Protection Authority (NRPA). The project has been partially financed by the Norwegian Research Council. Originating from the Norwegian project, a number of similar projects have been started or are in the planning stage in a number of European countries. The present report lays the ground for estimation of individual exposure histories to cosmic radiation of pilots flying a great diversity of different aircrafts. Aircrafts that appear in the time-tables of the Scandinavian Airline System (SAS) have been treated in an earlier report. The results presented in this report (radiation doserates for the different types of aircrafts in the different years) will, in a later stage of the project be utilized to estimate the individual radiation exposure histories. The major sources of information used as basis for the work in this report is information provided by several active pilots, members of the Pilots Associations, along with calculations performed using US Federal Aviation Administration`s computer code CARI-3N. 2 refs.

  4. SAS-2 observations of the galactic gamma radiation from the Vela region

    Science.gov (United States)

    Thompson, D. J.; Bignami, G. F.; Fichtel, C. E.; Kniffen, D. A.

    1974-01-01

    Data from a scan of the galactic plane by the SAS-2 high energy gamma ray experiment in the region 250 deg l2 290 deg show a statistically-significant excess over the general radiation from the galactic plane for gamma radiation of energy 100 MeV in the region 260 deg l2 270 deg and -7.5 deg b2 0 deg. If the enhanced gamma radiation results from interactions of cosmic rays with galactic matter, as the energy spectrum suggests, it seems reasonable to associate the enhancement with large scale galactic features, such as spiral arm segments in that direction, or with the region surrounding the Vela supernova remnant, with which PSR 0833-45 is associated. If the excess is attributed to cosmic rays released from this supernova interacting with the interstellar matter in that region, then on the order of 3.10 to the 50th power ergs would be released by that supernova in the form of cosmic rays.

  5. Age-related changes in the bone marrow and spleen of SAS/4 mice.

    Science.gov (United States)

    Coggle, J E; Gordon, M Y; Proukakis, C; Bogg, C E

    1975-01-01

    The total number of nucleated cells in the bone marrow of SAS/4 mice increase some twofold between 1 and 24 months of age but when related to body weight remains essentially constant over a wide range of ages. The concentration of CFU-S in femoral marrow is also constant with age and since other bones containing marrow appear, at least in young mice, to have the same CFU-S concentration as the femur it is concluded that the CFU-S compartment size of the whole bone marrow is independent of age when expressed on a body weight basis, In contrast, both the absolute number and the concentration of exogenous CFU-S in the spleen decline markedly in old mice. Smilary there is a decline in the number of endogenous colony-forming cells and the spleens of 24-month-old mice seem virtually devoid of such colonies. Not only were older mice less capable of supporting the growth of endogenous colonies, but their spleens also appear to provide a poorer environment for exogenous colony growth when compared with growth in younger recipient spleens.

  6. SAS 3 observations of two X-ray transient events with precursors

    Science.gov (United States)

    Hoffman, J. A.; Lewin, W. H. G.; Doty, J.; Jernigan, J. G.; Haney, M.; Richardson, J. A.

    1978-01-01

    SAS 3 has observed two unusual fast transient X-ray events from different sources, one lasting about 150 s and one, approximately 1500 s. Both events were preceded by precursor pulses which lasted a few seconds and which rose and fell in less than 0.4 s. The precursors were separated from the 'main' events by several seconds, during which no X-rays were detected. There are similarities between the two main events and X-ray bursts in both their temporal and spectral evolution. The spectra of the main events started out much softer than the spectra of the precursors, became harder as they approached maximum intensity, and softened as they decayed. In the 1500-s event, X-rays with energies greater than 10 keV were delayed by about 80 s compared with 1.5-6-keV X-rays. A blackbody fit to the spectral data of the main event of approximately 1500-s duration gives a maximum temperature of 29 million K and a radius for the emitting region of at least about 9 km (at a distance of 10 kpc); this is similar to the temperature and sizes found for several X-ray burst sources.

  7. Sulfuric acid speleogenesis (SAS) close to the water table: Examples from southern France, Austria, and Sicily

    Science.gov (United States)

    De Waele, Jo; Audra, Philippe; Madonia, Giuliana; Vattano, Marco; Plan, Lukas; D'Angeli, Ilenia M.; Bigot, Jean-Yves; Anoux, Catherine; Nobécourt, Jean-Claude

    2016-01-01

    Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H2S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H2S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or close to the water table but also in subaerial conditions in moisture films and droplets in the cave environment. These caves are generated at or immediately above the water table, where condensation-corrosion processes are dominant, creating a set of characteristic meso- and micromorphologies. Due to their close connection to the base level, these caves can also precisely record past hydrological and geomorphological settings. Certain authigenic cave minerals, produced during the sulfuric acid speleogenesis (SAS) phase, allow determination of the exact timing of speleogenesis. This paper deals with the morphological, geochemical and mineralogical description of four very typical sulfuric acid water table caves in Europe: the Grotte du Chat in the southern French Alps, the Acqua Fitusa Cave in Sicily (Italy), and the Bad Deutsch Altenburg and Kraushöhle caves in Austria.

  8. SAS-2 gamma-ray observations of PSR 1747-46

    Science.gov (United States)

    Thompson, D. J.; Fichtel, C. E.; Kniffen, D. A.; Lamb, R. C.; Oegelman, H. B.

    1976-01-01

    Observations with the SAS-2 high energy ( 35 MeV) gamma-ray telescope show evidence of gamma-ray emission from the radio pulsar PSR 1747-46. When the arrival times of gamma-rays from the region of the pulsar were converted to pulsar phases using the radio period and period derivative, a single peak was found in the phase plot, with a Poisson probability of occurring by chance of .00008. Independently, the time-averaged data for the PSR 1747-46 region show an enhancement over the surrounding region of the sky at the same galactic latitude, with a Poisson probability of chance occurrence of less than .008. The probability that these results are chance is the product of these two probabilities times the number of radio pulsars examined (73). This overall probability is sufficiently small (.00005) to suggest an identification of a new gamma-ray pulsar. In the gamma-ray pulsar plot, the peak falls 0.16 + or - 0.03 period after the radio pulsar peak. This phase shift is, within uncertainties, the same as that observed between the single radio peak and the first of the two gamma-ray peaks seen in the phase plot for PSR-0833-45 (the Vela pulsar).

  9. Stutter seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Gumma, W. H.; Hughes, D. R.; Zimmerman, N. S.

    1980-08-12

    An improved seismic prospecting system comprising the use of a closely spaced sequence of source initiations at essentially the same location to provide shorter objective-level wavelets than are obtainable with a single pulse. In a preferred form, three dynamite charges are detonated in the same or three closely spaced shot holes to generate a downward traveling wavelet having increased high frequency content and reduced content at a peak frequency determined by initial testing.

  10. Principle and Program of Evaluating Diffuse Seismicity

    Institute of Scientific and Technical Information of China (English)

    Chang Xiangdong

    2001-01-01

    Concept and origin of the term "the diffuse seismicity" are illustrated. Some different viewpoints regarding the diffuse seismicity and the influence characteristics on determining seismic design basis of engineering from the seismicity are analyzed. Principle and program for evaluating diffuse seismicity are studied and discussed base on over contents.

  11. The School Anxiety Scale-Teacher Report (SAS-TR: translation and psychometric properties of the Iranian version

    Directory of Open Access Journals (Sweden)

    Hajiamini Zahra

    2012-07-01

    Full Text Available Abstract Background The School Anxiety Scale-Teacher Report (SAS-TR was designed to assess anxiety in children at school. The SAS-TR is a proxy rated measure and could assess social anxiety, generalized anxiety and also gives a total anxiety score. This study aimed to translate and validate the SAS-TR in Iran. Methods The translation and cultural adaptation of the original questionnaire were carried out in accordance with the published guidelines. A sample of students participated in the study. Reliability was estimated using internal consistency and test-retest analysis. Validity was assessed using content validity. The factor structure of the questionnaire was extracted by performing both exploratory and confirmatory factor analyses. Results In all 200 elementary students aged 6 to 10 years were studied. Considering the recommended cut-off values, overall the prevalence of high anxiety condition in elementary students was found to be 21 %. Cronbach's alpha coefficient for the Iranian SAS-TR was 0.92 and intraclass correlation coefficient (ICC was found to be 0.81. The principal component analysis indicated a two-factor structure for the questionnaire (generalized and social anxiety that jointly accounted for 55.3 % of variances observed. The confirmatory factory analysis also indicated a good fit to the data for the two-latent structure of the questionnaire. Conclusion In general the findings suggest that the Iranian version of SAS-TR has satisfactory reliability, and validity for measuring anxiety in 6 to 10 years old children in Iran. It is simple and easy to use and now can be applied in future studies.

  12. Comparison of ArcGIS and SAS Geostatistical Analyst to Estimate Population-Weighted Monthly Temperature for US Counties.

    Science.gov (United States)

    Xiaopeng, Q I; Liang, Wei; Barker, Laurie; Lekiachvili, Akaki; Xingyou, Zhang

    Temperature changes are known to have significant impacts on human health. Accurate estimates of population-weighted average monthly air temperature for US counties are needed to evaluate temperature's association with health behaviours and disease, which are sampled or reported at the county level and measured on a monthly-or 30-day-basis. Most reported temperature estimates were calculated using ArcGIS, relatively few used SAS. We compared the performance of geostatistical models to estimate population-weighted average temperature in each month for counties in 48 states using ArcGIS v9.3 and SAS v 9.2 on a CITGO platform. Monthly average temperature for Jan-Dec 2007 and elevation from 5435 weather stations were used to estimate the temperature at county population centroids. County estimates were produced with elevation as a covariate. Performance of models was assessed by comparing adjusted R(2), mean squared error, root mean squared error, and processing time. Prediction accuracy for split validation was above 90% for 11 months in ArcGIS and all 12 months in SAS. Cokriging in SAS achieved higher prediction accuracy and lower estimation bias as compared to cokriging in ArcGIS. County-level estimates produced by both packages were positively correlated (adjusted R(2) range=0.95 to 0.99); accuracy and precision improved with elevation as a covariate. Both methods from ArcGIS and SAS are reliable for U.S. county-level temperature estimates; However, ArcGIS's merits in spatial data pre-processing and processing time may be important considerations for software selection, especially for multi-year or multi-state projects.

  13. Attenuation relations for horizontal peak ground acceleration and response spectrum in northeastern Tibetan Plateau region

    Institute of Scientific and Technical Information of China (English)

    俞言祥; 汪素云

    2004-01-01

    The seismic intensity attenuation relations in northeastern Tibetan Plateau region are established by a regression analysis on isoseismal data. Then the attenuation relations for horizontal peak ground acceleration and short-period response spectrum for western North America are derived based on the database of HUO Jun-rong and strong motion data from recent earthquakes. The attenuation relations of long-period response spectrum for western North America are developed by analyzing the broadband digital seismic recordings of southern California. By integrating the short-period and long-period attenuation relationships, the attenuation relations for horizontal acceleration response spectrum in the period range of 0.04~6 s for western North America are established. The attenuation equation that accounts for the magnitude saturation and near-field saturation of high frequency ground motion is used. Finally the attenuation relations for horizontal peak ground acceleration and response spectrum for the region of northeastern Tibetan Plateau are developed by using the transforming method.

  14. Probabilistic seismic hazard assessment based on seismic potential of active faults: Example from northern Algeria

    Science.gov (United States)

    Bouhadad, Youcef

    2017-04-01

    Northern Algeria is an interplate area where the African and the Eurasian tectonic plates are converging in the NW-SE direction. Therefore, earthquakes are not distributed randomly but directly related to the activity of active faults. The seismotectonic conditions of occurrence of strong damaging earthquakes in the area are well understood following the numerous detailed studies that followed the El-Asnam October 10th , 1980 earthquake (Ms=7.3) and the Zemmouri May 1st , 2003 (Mw=6.8) earthquake. The potentially active structures consist of active folds or asymmetrical folds underlined by thrust faults. Some of the faults are blind as revealed by the Chenoua 29th , 1989 (Ms=6.0) and the Ain Temouchent 1999 (Ms=5.6) earthquakes. We applied the probabilistic approach to assess seismic hazard in the area of Mostaganem, western Algeria. The following steps are performed (i) Seismic sources are identified on the basis of field geological/geophysical investigations,(ii) Source parameters such as b-values, slip rate and maximum magnitude are assessed for each seismic source, and then given a weight in the framework of a logic tree model, (iii) Attenuation relations which fit Algerian strong motion records are used, (iv) Results are presented as annual frequencies of exceedance versus peak ground acceleration (PGA) as well as maps of hazard for different return periods. Finally, we quantified and discussed the scientific uncertainties related to the state of knowledge and the used alternative models and values. Keywords: seismic hazard- active faults- probabilistic approach- uncertainties-Algeria

  15. Nonstationary sparsity-constrained seismic deconvolution

    Science.gov (United States)

    Sun, Xue-Kai; Sam, Zandong Sun; Xie, Hui-Wen

    2014-12-01

    The Robinson convolution model is mainly restricted by three inappropriate assumptions, i.e., statistically white reflectivity, minimum-phase wavelet, and stationarity. Modern reflectivity inversion methods (e.g., sparsity-constrained deconvolution) generally attempt to suppress the problems associated with the first two assumptions but often ignore that seismic traces are nonstationary signals, which undermines the basic assumption of unchanging wavelet in reflectivity inversion. Through tests on reflectivity series, we confirm the effects of nonstationarity on reflectivity estimation and the loss of significant information, especially in deep layers. To overcome the problems caused by nonstationarity, we propose a nonstationary convolutional model, and then use the attenuation curve in log spectra to detect and correct the influences of nonstationarity. We use Gabor deconvolution to handle nonstationarity and sparsity-constrained deconvolution to separating reflectivity and wavelet. The combination of the two deconvolution methods effectively handles nonstationarity and greatly reduces the problems associated with the unreasonable assumptions regarding reflectivity and wavelet. Using marine seismic data, we show that correcting nonstationarity helps recover subtle reflectivity information and enhances the characterization of details with respect to the geological record.

  16. Establishing seismic design criteria to achieve an acceptable seismic margin

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R.P. [RPK Structural Mechanics Consulting, Inc., Yorba Linda, CA (United States)

    1997-01-01

    In order to develop a risk based seismic design criteria the following four issues must be addressed: (1) What target annual probability of seismic induced unacceptable performance is acceptable? (2). What minimum seismic margin is acceptable? (3) Given the decisions made under Issues 1 and 2, at what annual frequency of exceedance should the Safe Shutdown Earthquake ground motion be defined? (4) What seismic design criteria should be established to reasonably achieve the seismic margin defined under Issue 2? The first issue is purely a policy decision and is not addressed in this paper. Each of the other three issues are addressed. Issues 2 and 3 are integrally tied together so that a very large number of possible combinations of responses to these two issues can be used to achieve the target goal defined under Issue 1. Section 2 lays out a combined approach to these two issues and presents three potentially attractive combined resolutions of these two issues which reasonably achieves the target goal. The remainder of the paper discusses an approach which can be used to develop seismic design criteria aimed at achieving the desired seismic margin defined in resolution of Issue 2. Suggestions for revising existing seismic design criteria to more consistently achieve the desired seismic margin are presented.

  17. Seismic wave propagation in granular media

    Science.gov (United States)

    Tancredi, Gonzalo; López, Francisco; Gallot, Thomas; Ginares, Alejandro; Ortega, Henry; Sanchís, Johnny; Agriela, Adrián; Weatherley, Dion

    2016-10-01

    Asteroids and small bodies of the Solar System are thought to be agglomerates of irregular boulders, therefore cataloged as granular media. It is a consensus that many asteroids might be considered as rubble or gravel piles.Impacts on their surface could produce seismic waves which propagate in the interior of these bodies, thus causing modifications in the internal distribution of rocks and ejections of particles and dust, resulting in a cometary-type comma.We present experimental and numerical results on the study of propagation of impact-induced seismic waves in granular media, with special focus on behavior changes by increasing compression.For the experiment, we use an acrylic box filled with granular materials such as sand, gravel and glass spheres. Pressure inside the box is controlled by a movable side wall and measured with sensors. Impacts are created on the upper face of the box through a hole, ranging from free-falling spheres to gunshots. We put high-speed cameras outside the box to record the impact as well as piezoelectic sensors and accelerometers placed at several depths in the granular material to detect the seismic wave.Numerical simulations are performed with ESyS-Particle, a software that implements the Discrete Element Method. The experimental setting is reproduced in the numerical simulations using both individual spherical particles and agglomerates of spherical particles shaped as irregular boulders, according to rock models obtained with a 3D scanner. The numerical experiments also reproduces the force loading on one of the wall to vary the pressure inside the box.We are interested in the velocity, attenuation and energy transmission of the waves. These quantities are measured in the experiments and in the simulations. We study the dependance of these three parameters with characteristics like: impact speed, properties of the target material and the pressure in the media.These results are relevant to understand the outcomes of impacts in

  18. Seismic basement in Poland

    Science.gov (United States)

    Grad, Marek; Polkowski, Marcin

    2016-06-01

    The area of contact between Precambrian and Phanerozoic Europe in Poland has complicated structure of sedimentary cover and basement. The thinnest sedimentary cover in the Mazury-Belarus anteclize is only 0.3-1 km thick, increases to 7-8 km along the East European Craton margin, and 9-12 km in the Trans-European Suture Zone (TESZ). The Variscan domain is characterized by a 1- to 2-km-thick sedimentary cover, while the Carpathians are characterized by very thick sediments, up to c. 20 km. The map of the basement depth is created by combining data from geological boreholes with a set of regional seismic refraction profiles. These maps do not provide data about the basement depth in the central part of the TESZ and in the Carpathians. Therefore, the data set is supplemented by 32 models from deep seismic sounding profiles and a map of a high-resistivity (low-conductivity) layer from magnetotelluric soundings, identified as a basement. All of these data provide knowledge about the basement depth and of P-wave seismic velocities of the crystalline and consolidated type of basement for the whole area of Poland. Finally, the differentiation of the basement depth and velocity is discussed with respect to geophysical fields and the tectonic division of the area.

  19. Tritium Attenuation by Distillation

    Energy Technology Data Exchange (ETDEWEB)

    Wittman, N.E.

    2001-07-31

    The objective of this study was to determine how a 100 Area distillation system could be used to reduce to a satisfactory low value the tritium content of the dilute moderator produced in the 100 Area stills, and whether such a tritium attenuator would have sufficient capacity to process all this material before it is sent to the 400 Area for reprocessing.

  20. Optical Attenuation Coefficient Meter

    Science.gov (United States)

    2016-06-22

    back scattered light 202. The back scattered light 202 travels to the attenuation meter 10 after scattering by thermodynamic density fluctuations and...invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching . Such