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Sample records for strong low-velocity anomaly

  1. Seismic Travel Time Tomography in Modeling Low Velocity Anomalies between the Boreholes

    Science.gov (United States)

    Octova, A.; Sule, R.

    2018-04-01

    Travel time cross-hole seismic tomography is applied to describing the structure of the subsurface. The sources are placed at one borehole and some receivers are placed in the others. First arrival travel time data that received by each receiver is used as the input data in seismic tomography method. This research is devided into three steps. The first step is reconstructing the synthetic model based on field parameters. Field parameters are divided into 24 receivers and 45 receivers. The second step is applying inversion process for the field data that consists of five pairs bore holes. The last step is testing quality of tomogram with resolution test. Data processing using FAST software produces an explicit shape and resemble the initial model reconstruction of synthetic model with 45 receivers. The tomography processing in field data indicates cavities in several place between the bore holes. Cavities are identified on BH2A-BH1, BH4A-BH2A and BH4A-BH5 with elongated and rounded structure. In resolution tests using a checker-board, anomalies still can be identified up to 2 meter x 2 meter size. Travel time cross-hole seismic tomography analysis proves this mothod is very good to describing subsurface structure and boundary layer. Size and anomalies position can be recognized and interpreted easily.

  2. Relationship Between Low-Velocity S-wave Anomalies, Asthenospheric Dynamics and Basaltic Volcanism in the Intraplate Setting of the Basin and Range, USA

    Science.gov (United States)

    Tibbetts, A. K.; Smith, E. I.; Conrad, C. P.; Lee, C.; Plank, T.; Yang, Y.

    2009-12-01

    Pliocene to Recent intraplate mafic volcanic rocks of the Basin and Range Province mostly formed by asthenospheric melting, as determined from calculated melting temperatures ranging from 1249-1521 degrees C. Here asthenosphere is defined by mantle rheology and temperature and not by geochemistry. The duration of melting in a volcanic field may be related to the size and shape of pockets of low velocity asthenosphere moving under the areas of volcanism. Seismic S-wave velocity profiles constrained by ambient noise and earthquake tomography of the mantle (Yang et al., 2008) show low velocity pockets, which may correspond to higher temperatures and/or higher water contents. The lack of wider scale volcanism in the Basin and Range despite large scale anomalies indicates that the anomalies are not the only cause of melting. The observed smaller scale magmatism can be explained by circulatory flow driven by the small scale structure of the anomalies causing localized melting within the anomalies. By applying an asthenospheric shear flow velocity of 0 cm/yr at the base of the lithosphere and 5 cm/yr east at depth (Silver & Holt 2002, Conrad et al., 2007), the distance the mantle has moved since the time of volcanism can be calculated for basalts of known age. Past positions of low-velocity anomalies in the asthenosphere combined with depths and temperatures of melting calculated using the silica-liquid geobarometer (Lee et al., 2009) were used to determine if a low velocity anomaly existed under an area of volcanism at the depth of melting and time of eruption. The data constraints used for calculating depths and temperatures of melting are dry, MgO > 7.5 wt.%, SiO2 > 44 wt.%, and Fe as 90% Fe2+. Depths and temperatures of melting were calculated for San Francisco in AZ; Amboy, Pisgah, Death Valley, Coso, Big Pine, Cima, Long Valley, in CA; Crater Flat, Lunar Crater, Reveille in NV; and Black Rock, Hurricane, Snow Canyon, UT; and others all of which have known ages. Ages

  3. Thermal infrared anomalies of several strong earthquakes.

    Science.gov (United States)

    Wei, Congxin; Zhang, Yuansheng; Guo, Xiao; Hui, Shaoxing; Qin, Manzhong; Zhang, Ying

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of "time-frequency relative power spectrum." (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

  4. Thermal Infrared Anomalies of Several Strong Earthquakes

    Directory of Open Access Journals (Sweden)

    Congxin Wei

    2013-01-01

    Full Text Available In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1 There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of “time-frequency relative power spectrum.” (2 There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3 Thermal radiation anomalies are closely related to the geological structure. (4 Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

  5. Thermal Infrared Anomalies of Several Strong Earthquakes

    Science.gov (United States)

    Wei, Congxin; Guo, Xiao; Qin, Manzhong

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of “time-frequency relative power spectrum.” (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting. PMID:24222728

  6. Effects of Strong Correlations on the Disorder-Induced Zero Bias Anomaly

    Science.gov (United States)

    Atkinson, William; Song, Yun; Bulut, Sinan; Wortis, Rachel

    2009-03-01

    In conventional metals and semiconductors, density of states anomalies result from the interplay between disorder and interactions. Motivated by a number of experiments that find zero bias anomalies (ZBA) in transition metal oxides, we have performed calculations to determine the effect of strong correlations on the ZBA in disordered interacting systems. We use a self-consistent mean-field theory that incorporates strong correlations and treats spatial fluctuations of the disorder potential exactly. We discuss both the Anderson-Hubbard model and the extended Anderson-Hubbard model. We find that, even for a zero-range interaction, nonlocal self-energy corrections lead to the formation of an Altshuler-Aronov-like ZBA. In the extended Anderson-Hubbard model, Efros-Shklovskii-like physics dominates at large disorder.

  7. Anomalies.

    Science.gov (United States)

    Online-Offline, 1999

    1999-01-01

    This theme issue on anomalies includes Web sites, CD-ROMs and software, videos, books, and additional resources for elementary and junior high school students. Pertinent activities are suggested, and sidebars discuss UFOs, animal anomalies, and anomalies from nature; and resources covering unexplained phenonmenas like crop circles, Easter Island,…

  8. Anomaly disturbances of the magnetic fields before the strong earthquake in Japan on March 11, 2011

    Directory of Open Access Journals (Sweden)

    Masashi Hayakawa

    2012-04-01

    frequency range, the anomalies were not well defined.

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  9. Ultra-low velocity zone heterogeneities at the core-mantle boundary from diffracted PKKPab waves

    Science.gov (United States)

    Ma, Xiaolong; Sun, Xinlei

    2017-08-01

    Diffracted waves around Earth's core could provide important information of the lowermost mantle that other seismic waves may not. We examined PKKPab diffraction waves from 52 earthquakes occurring at the western Pacific region and recorded by USArray to probe the velocity structure along the core-mantle boundary (CMB). These diffracted waves emerge at distances up to 10° past the theoretical cutoff epicentral distance and show comparable amplitudes. We measured the ray parameters of PKKPab diffraction waves by Radon transform analysis that is suitable for large-aperture arrays. These ray parameters show a wide range of values from 4.250 to 4.840 s/deg, suggesting strong lateral heterogeneities in sampling regions at the base of the mantle. We further estimated the P-wave velocity variations by converting these ray parameters and found the CMB regions beneath the northwestern edge of African Anomaly (Ritsma et al. in Science 286:1925-1928, 1999) and southern Sumatra Islands exhibit velocity reductions up to 8.5% relative to PREM. We suggest that these low velocity regions are Ultra-low velocity zones, which may be related to partial melt or iron-enriched solids.[Figure not available: see fulltext.

  10. Breakdown of the Chiral Anomaly in Weyl Semimetals in a Strong Magnetic Field

    Science.gov (United States)

    Kim, Pilkwang; Ryoo, Ji Hoon; Park, Cheol-Hwan

    2017-12-01

    The low-energy quasiparticles of Weyl semimetals are a condensed-matter realization of the Weyl fermions introduced in relativistic field theory. Chiral anomaly, the nonconservation of the chiral charge under parallel electric and magnetic fields, is arguably the most important phenomenon of Weyl semimetals and has been explained as an imbalance between the occupancies of the gapless, zeroth Landau levels with opposite chiralities. This widely accepted picture has served as the basis for subsequent studies. Here we report the breakdown of the chiral anomaly in Weyl semimetals in a strong magnetic field based on ab initio calculations. A sizable energy gap that depends sensitively on the direction of the magnetic field may open up due to the mixing of the zeroth Landau levels associated with the opposite-chirality Weyl points that are away from each other in the Brillouin zone. Our study provides a theoretical framework for understanding a wide range of phenomena closely related to the chiral anomaly in topological semimetals, such as magnetotransport, thermoelectric responses, and plasmons, to name a few.

  11. Upper mantle low velocity heterogeneities beneath NE China revealed by source- and receiver-side converted waves

    Science.gov (United States)

    Guan, Z.; Niu, F.

    2017-12-01

    Common-conversion-point (CCP) stacking of receiver function is a powerful tool in mapping upper mantle heterogeneities. However, reverberations from shallow boundaries with large velocity contrast could contaminate the imaging profiles severely. Applying the refined Slowness Weighted CCP (SWCCP) stacking technique (Guan and Niu, 2017) on NECESSArray data, we eliminated the multiple effects and systematically imaged the upper mantle low velocity heterogeneities in NE China where there exist rich unconsolidated sediments. The SWCCP profiles reveal a 350 km low velocity heterogeneity which is possibly associated with the Changbai Mountain volcanism and interpreted as a negatively buoyant silicate melt lying atop of the 410 km discontinuity. Besides, the imaging results are also suggestive of a sporadic 580-620 km low velocity heterogeneity locating in the easternmost part of NE China with a velocity contrast comparable with the 660-km discontinuity. In addition, between 42º N and 45º N, we also found a double 660-km discontinuity at the two sides of the localized depression in the longitudinal range of 128º E to 131º E. On the other hand, we gathered USArray and Alaska regional array seismic data of deep earthquakes occurring beneath NE China and the surrounding areas and employed stacking technique to study the source side S-to-P conversions. The source-side stacking also showed a strong S-to-P conversion at 600 km deep, consistent with the SWCCP stacks. Meanwhile, we also confirmed the double 660-km discontinuity feature from the source-side conversions. The receiver- and source-side observations provide strong constraints on these low velocity anomalies that may offer insights on the subduction dynamics of the Pacific plate.

  12. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    Science.gov (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  13. Strong post-midnight Equatorial Ionospheric Anomaly and Equatorial spread F Observations during magnetically quiet period

    Science.gov (United States)

    Moldwin, M. B.; Yizengaw, E.; Sahai, Y.

    2008-12-01

    Post sunset equatorial ionospheric irregularities, especially during magnetically active periods, have been a subject of many studies. The most prominent irregularities often observed right after sunset are the resurgence of the equatorial ionospheric anomaly (EIA) and equatorial spread F (ESF). It is well understood and documented that pre-reversal enhancement, due to the ionospheric conductivity gradient at the dusk, is one of the prime triggering mechanisms for the post-sunset irregularities in the equatorial region. However, less attention has been given to the equatorial irregularities (EIA and ESF) that often occur in post-midnight, especially during magnetically quiet periods. It has been suggested that the primary process responsible for the dramatic post-midnight ESF during magnetically active periods is the change in magnitude and direction of the usual equatorial electric field. Earlier studies speculated that during magnetically active post-midnight periods the change in electric field direction from westward to eastward for a short intervals cause an upward E × B drift, resulting in increased h'F and decreased electron densities at the magnetic equator. Individual scans of Jicamarca vertical drift also often observe significant upward drift during post-midnight periods. We present a case of post-midnight strong equatorial ionospheric anomaly during a magnetically quiet (Kp < 3) period using TOPEX altimeter TEC data. Simultaneously, the ionosonde station at S.J. Campos (23.2°S, 45.9°W; dip lat. 17.6°S) observed strong ESF and unusual h'F height rise during post-midnight period, where TOPEX detected strong EIA. At the same time ROCSAT-1 and DMSP satellites also clearly show existence of EIA during post-midnight period at their orbiting altitude. The former satellite also detected post-midnight in situ density irregularities (such as bubbles) at the same time as strong EIA and ESF. The questions here are what triggers these post-midnight equatorial

  14. Thermal anomalies detection before strong earthquakes (M > 6.0 using interquartile, wavelet and Kalman filter methods

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    M. Akhoondzadeh

    2011-04-01

    Full Text Available Thermal anomaly is known as a significant precursor of strong earthquakes, therefore Land Surface Temperature (LST time series have been analyzed in this study to locate relevant anomalous variations prior to the Bam (26 December 2003, Zarand (22 February 2005 and Borujerd (31 March 2006 earthquakes. The duration of the three datasets which are comprised of MODIS LST images is 44, 28 and 46 days for the Bam, Zarand and Borujerd earthquakes, respectively. In order to exclude variations of LST from temperature seasonal effects, Air Temperature (AT data derived from the meteorological stations close to the earthquakes epicenters have been taken into account. The detection of thermal anomalies has been assessed using interquartile, wavelet transform and Kalman filter methods, each presenting its own independent property in anomaly detection. The interquartile method has been used to construct the higher and lower bounds in LST data to detect disturbed states outside the bounds which might be associated with impending earthquakes. The wavelet transform method has been used to locate local maxima within each time series of LST data for identifying earthquake anomalies by a predefined threshold. Also, the prediction property of the Kalman filter has been used in the detection process of prominent LST anomalies. The results concerning the methodology indicate that the interquartile method is capable of detecting the highest intensity anomaly values, the wavelet transform is sensitive to sudden changes, and the Kalman filter method significantly detects the highest unpredictable variations of LST. The three methods detected anomalous occurrences during 1 to 20 days prior to the earthquakes showing close agreement in results found between the different applied methods on LST data in the detection of pre-seismic anomalies. The proposed method for anomaly detection was also applied on regions irrelevant to earthquakes for which no anomaly was detected

  15. Indentation of aluminium foam at low velocity

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    Shi Xiaopeng

    2015-01-01

    Full Text Available The indentation behaviour of aluminium foams at low velocity (10 m/s ∼ 30 m/s was investigated both in experiments and numerical simulation in this paper. A flat-ended indenter was used and the force-displacement history was recorded. The Split Hopkinson Pressure bar was used to obtain the indentation velocity and forces in the dynamic experiments. Because of the low strength of the aluminium foam, PMMA bar was used, and the experimental data were corrected using Bacon's method. The energy absorption characteristics varying with impact velocity were then obtained. It was found that the energy absorption ability of aluminium foam gradually increases in the quasi-static regime and shows a significant increase at ∼10 m/s velocity. Numerical simulation was also conducted to investigate this process. A 3D Voronoi model was used and models with different relative densities were investigated as well as those with different failure strain. The indentation energy increases with both the relative density and failure strain. The analysis of the FE model implies that the significant change in energy absorption ability of aluminium foam in indentation at ∼10 m/s velocity may be caused by plastic wave effect.

  16. Influence of calculation error of total field anomaly in strongly magnetic environments

    Science.gov (United States)

    Yuan, Xiaoyu; Yao, Changli; Zheng, Yuanman; Li, Zelin

    2016-04-01

    An assumption made in many magnetic interpretation techniques is that ΔTact (total field anomaly - the measurement given by total field magnetometers, after we remove the main geomagnetic field, T0) can be approximated mathematically by ΔTpro (the projection of anomalous field vector in the direction of the earth's normal field). In order to meet the demand for high-precision processing of magnetic prospecting, the approximate error E between ΔTact and ΔTpro is studied in this research. Generally speaking, the error E is extremely small when anomalies not greater than about 0.2T0. However, the errorE may be large in highly magnetic environments. This leads to significant effects on subsequent quantitative inference. Therefore, we investigate the error E through numerical experiments of high-susceptibility bodies. A systematic error analysis was made by using a 2-D elliptic cylinder model. Error analysis show that the magnitude of ΔTact is usually larger than that of ΔTpro. This imply that a theoretical anomaly computed without accounting for the error E overestimate the anomaly associated with the body. It is demonstrated through numerical experiments that the error E is obvious and should not be ignored. It is also shown that the curves of ΔTpro and the error E had a certain symmetry when the directions of magnetization and geomagnetic field changed. To be more specific, the Emax (the maximum of the error E) appeared above the center of the magnetic body when the magnetic parameters are determined. Some other characteristics about the error Eare discovered. For instance, the curve of Emax with respect to the latitude was symmetrical on both sides of magnetic equator, and the extremum of the Emax can always be found in the mid-latitudes, and so on. It is also demonstrated that the error Ehas great influence on magnetic processing transformation and inversion results. It is conclude that when the bodies have highly magnetic susceptibilities, the error E can

  17. Strong anomaly, spectral-density sum rules, and broken (U(3) x U(3) symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, S.; Bagchi, B.

    1983-05-01

    We obtain by making use of the anomaly term in the divergence of the flavor-singlet-axial-vector-current new spectral-function sum rules for the pseudoscalar density in a chiral SU()3) x SU(3) x U/sub 3/(1) framework. The positivity conditions on the spectral representations of the pseudoscalar densities lead to a new bound on the quark-condensate term <0Vertical Barq-barqVertical Bar0>< or =-(279 MeV)/sup 3/ (q = u, d, and s) corresponding bare-current-quark values of m/sub u/ = m/sub d/roughly-equal5 MeV and m/sub s/roughly-equal150 MeV.

  18. Global navigation satellite system detection of preseismic ionospheric total electron content anomalies for strong magnitude (Mw>6) Himalayan earthquakes

    Science.gov (United States)

    Sharma, Gopal; Champati ray, Prashant Kumar; Mohanty, Sarada; Gautam, Param Kirti Rao; Kannaujiya, Suresh

    2017-10-01

    Electron content in the ionosphere is very sensitive to temporary disturbances of the Earth's magnetosphere (geomagnetic storm), solar flares, and seismic activities. The Global Navigation Satellite System (GNSS)-based total electron content (TEC) measurement has emerged as an important technique for computations of earthquake precursor signals. We examined the pre-earthquake signatures for eight strong magnitude (Mw>6: 6.1 to 7.8) earthquakes with the aid of GNSS-based TEC measurement in the tectonically active Himalayan region using International GNSS Service (IGS) stations as well as local GNSS-based continuously operating reference stations (CORS). The results indicate very significant ionospheric anomalies in the vertical total electron content (vTEC) a few days before the main shock for all of the events. Geomagnetic activities were also studied during the TEC observation window to ascertain their role in ionospheric perturbations. It was also inferred that TEC variation due to low magnitude events could also be monitored if the epicenter lies closer to the GNSS or IGS station. Therefore, the study has confirmed TEC anomalies before major Himalayan earthquakes, thereby making it imperative to set up a much denser network of IGS/CORS for real-time data analysis and forewarning.

  19. Size-effect of explosive sensitivity under low velocity impact

    Science.gov (United States)

    Ma, Danzhu; Chen, Pengwan; Zhou, Qiang

    2013-06-01

    Low velocity impact may ignite the solid high explosives and cause undesired explosion incidents. The safety of high explosives under low velocity impact is one of the most important problems in handling, manufacture, storage, and transportation procedures. More and more evaluation tests have been developed for low velocity impact scenarios, including, but not limited to the drop hammer impact test, the Susan test, the Spigot test, and the Steven test, with a charge mass varying from tens of milligrams to several kilograms. The effects of specimen size on explosive sensitivity were found in our drop hammer impact test and Steven tests, including the threshold velocity/height and reaction violence. To further analyze the size effects on explosive sensitivity under low velocity impacts, we collected the impact sensitivity data of several PBX explosives in the drop hammer test, the Steven test, the Susan test and the Spigot test. The effective volume of explosive charge and the threshold specific mechanical energy were introduced to investigate the size-effect on the explosive ignition thresholds. The effective volumes of explosive charge in Steven test and Spigot test were obtained by numerical simulation, due to the localization of the impact. The threshold specific mechanical energy is closely related to the effective volume of explosive charge. The results show that, with the increase of effective volume, the specific mechanical energy needed for explosive ignition decreases and trends to reach a constant value. The mechanisms of size effects on explosive sensitivity are also discussed.

  20. Specimen size effect of explosive sensitivity under low velocity impact

    Science.gov (United States)

    Ma, Danzhu; Chen, Pengwan; Dai, Kaida; Zhou, Qiang

    2014-05-01

    Low velocity impact may ignite the solid high explosives and cause undesired explosion incidents. The safety of high explosives under low velocity impact is one of the most important issues in handling, manufacture, storage, and transportation procedures. Various evaluation tests have been developed for low velocity impact scenarios, including, but not limited to the drop hammer test, the Susan test, the Spigot test, and the Steven test, with a charge mass varying from tens of milligrams to several kilograms. The effects of specimen size on explosive sensitivity were found in some impact tests such as drop hammer test and Steven tests, including the threshold velocity/height and reaction violence. To analyse the specimen size effects on explosive sensitivity under low velocity impacts, we collected the impact sensitivity data of several PBX explosives in the drop hammer test, the Steven test, the Susan test and the Spigot test. The effective volume of explosive charge and the critical specific mechanical energy were introduced to investigate the size-effect on the explosive reaction thresholds. The effective volumes of explosive charge in Steven test and Spigot test were obtained by numerical simulation, due to the deformation localization of the impact loading. The critical specific mechanical energy is closely related to the effective volume of explosive charge. The results show that, with the increase of effective volume, the critical mechanical energy needed for explosive ignition decreases and tends to reach a constant value. The mechanisms of size effects on explosive sensitivity are also discussed.

  1. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    Keywords. Ultra high strength concrete; panel; drop weight test; impact analysis; ABAQUS. Abstract. This paper presents the results of an investigation carried out on Ultra High Strength Concrete (UHSC) panels subjected to low velocity projectile impact to assess impact resistance. UHSC panel of size 350 × 350 mm and ...

  2. Waveform anomaly caused by strong attenuation in the crust and upper mantle in the Okinawa Trough region

    Science.gov (United States)

    Padhy, S.; Furumura, T.; Maeda, T.

    2017-12-01

    The Okinawa Trough is a young continental back-arc basin located behind the Ryukyu subduction zone in southwestern Japan, where the Philippine Sea Plate dives beneath the trough, resulting in localized mantle upwelling and crustal thinning of the overriding Eurasian Plate. The attenuation structure of the plates and surrounding mantle in this region associated with such complex tectonic environment are poorly documented. Here we present seismological evidence for these features based on the high-resolution waveform analyses and 3D finite difference method (FDM) simulation. We analyzed regional broadband waveforms recorded by F-net (NIED) of in-slab events (M>4, H>100 km). Using band-passed (0.5-8 Hz), mean-squared envelopes, we parameterized coda-decay in terms of rise-time (time from P-arrival to maximum amplitude in P-coda), decay-time (time from maximum amplitude to theoretical S-arrival), and energy-ratio defined as the ratio of energy in P-coda to that in direct P wave. The following key features are observed. First, there is a striking difference in S-excitation along paths traversing and not traversing the trough: events from SW Japan not crossing the trough show clear S waves, while those occurring in the trough show very weak S waves at a station close to the volcanic front. Second, some trough events exhibit spindle-shaped seismograms with strong P-coda excitation, obscuring the development of S waves, at back-arc stations; these waveforms are characterized by high decay-time (>10s) and high energy-ratio (>>1.0), suggesting strong forward scattering along ray paths. Third, some trough events show weak S-excitation characterized by low decay-time (<5s) and low energy-ratio (<1.0) at fore-arc stations, suggesting high intrinsic absorption. To investigate the mechanism of the observed anomalies, we will conduct FDM simulation for a suite of models comprising the key subduction features like localized mantle-upwelling and crustal thinning expected in the

  3. On a stabilization mechanism for low-velocity detonations

    KAUST Repository

    Sow, Aliou

    2017-03-08

    We use numerical simulations of the reactive Lula equations to analyse the nonlinear stability of steady-state one-dimensional solutions for gaseous detonations in the presence of both momentum and heat losses. Our results point to a possible stabilization mechanism for the low-velocity detonations in such systems. The mechanism stems from the existence of a one-parameter family of solutions found in Semenko el al.

  4. Low velocity impact of 6082-T6 aluminum plates

    Science.gov (United States)

    Mocian, Oana Alexandra; Constantinescu, Dan Mihai; Sandu, Marin; Sorohan, Ştefan

    2018-02-01

    The low velocity domain covers vehicle impacts, ship collisions and even accidentally tool drops. Even though more and more research is needed into these fields, most of the papers concerning impact problems focus on impact at medium and high velocities. Understanding the behavior of structures subjected to low velocity impact is of major importance when referring to impact resistance and damage tolerance. The paper presents an experimental and numerical investigation on the low velocity behavior of 6082-T6 aluminum plates. Impact tests were performed using an Instron Ceast 9340 drop-weight testing machine. In the experimental procedure, square plates were mounted on a circular support, fixed with a pneumatic clamping system and impacted with a hemispherical steel projectile. Specimens were impacted at constant weight and different impact velocities. The effect of different impact energies was investigated. The impact event was then simulated using the nonlinear finite element code LS_DYNA in order to determine the effect of strain rate upon the mechanical behavior of the aluminum plates. Moreover, in order to capture the exact behavior of the material, a special attention has been given to the selection of the correct material model and its parameters, which, in large extent, depend on the observed behavior of the aluminum plate during the test and the actual response of the plate under simulation. The numerical predictions are compared with the experimental observations and the applicability of the numerical model for further researches is analyzed.

  5. Growth anomalies on the coral genera Acropora and Porites are strongly associated with host density and human population size across the Indo-Pacific.

    Directory of Open Access Journals (Sweden)

    Greta S Aeby

    Full Text Available Growth anomalies (GAs are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA (n = 304 surveys and Porites growth anomalies (PGA (n = 602 surveys from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies found on different host genera (Acropora vs. Porites. As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment.

  6. Growth anomalies on the coral genera Acropora and Porites are strongly associated with host density and human population size across the Indo-Pacific.

    Science.gov (United States)

    Aeby, Greta S; Williams, Gareth J; Franklin, Erik C; Haapkyla, Jessica; Harvell, C Drew; Neale, Stephen; Page, Cathie A; Raymundo, Laurie; Vargas-Ángel, Bernardo; Willis, Bette L; Work, Thierry M; Davy, Simon K

    2011-02-18

    Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment.

  7. Soil Properties from Low-Velocity Probe Penetration

    Directory of Open Access Journals (Sweden)

    Jerome B. Johnson

    2008-01-01

    Full Text Available A physical model of low-velocity probe penetration is developed to characterize soil by type, strength, maximum compaction, and initial density using Newton's second law to describe the processes controlling probe momentum loss. The probe loses momentum by causing soil failure (strength, accelerating and compacting soil around the probe (inertia, and through frictional sliding at the probe/soil interface (friction. Probe geometry, mass, and impact velocity influences are incorporated into the model. Model predictions of probe deceleration history and depth of penetration agree well with experiments, without the need for free variables or complex numerical simulations.

  8. Modeling delamination of FRP laminates under low velocity impact

    Science.gov (United States)

    Jiang, Z.; Wen, H. M.; Ren, S. L.

    2017-09-01

    Fiber reinforced plastic laminates (FRP) have been increasingly used in various engineering such as aeronautics, astronautics, transportation, naval architecture and their impact response and failure are a major concern in academic community. A new numerical model is suggested for fiber reinforced plastic composites. The model considers that FRP laminates has been constituted by unidirectional laminated plates with adhesive layers. A modified adhesive layer damage model that considering strain rate effects is incorporated into the ABAQUS / EXPLICIT finite element program by the user-defined material subroutine VUMAT. It transpires that the present model predicted delamination is in good agreement with the experimental results for low velocity impact.

  9. Damage in woven CFRP laminates subjected to low velocity impacts

    International Nuclear Information System (INIS)

    Ullah, H; Abdel-Wahab, A A; Harland, A R; Silberschmidt, V V

    2012-01-01

    Carbon fabric-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution in these materials affects both their in-service properties and performance that can deteriorate with time. These processes need adequate means of analysis and investigation, the major approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in woven composite laminates due to low-velocity dynamic out-of-plane bending. Experimental tests are carried out to characterise the behaviour of such laminates under large-deflection dynamic bending in un-notched specimens in Izod tests using a Resil Impactor. A series of low-velocity impact tests is carried out at various levels of impact energy to assess the energy absorbed and force-time response of CFRP laminates. X-ray micro computed tomography (micro-CT) is used to investigate material damage modes in the impacted specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply delamination and intra-ply delamination, such as tow debonding and fabric fracture, were the prominent damage modes.

  10. Low velocity impact testing and nondestructive evaluation of transparent materials

    International Nuclear Information System (INIS)

    Brennan, R. E.; Green, W. H.

    2011-01-01

    Advanced transparent materials are used in protective systems for enhancing the survivability of ground vehicles, air vehicles, and personnel in applications such as face shields, riot gear, and vehicle windows. Low velocity impact damage can limit visibility and compromise the structural integrity of a transparent system, increasing the likelihood of further damage or penetration from a high velocity impact strike. For this reason, it is critical to determine damage tolerance levels of transparent systems to indicate whether or not a component should be replaced. In this study, transparent laminate systems will be tested by comparing baseline conditions to experimentally controlled damage states. Destructive testing including air gun and sphere impact testing will be used to replicate low velocity impacts in the field. Characterization of the damaged state will include basic visual inspection as well as nondestructive techniques including cross-polarization, x-ray, and ultrasound. The combination of destructive testing and characterization of the resulting damage can help to establish a damage acceptance criterion for materials used in protective systems.

  11. Damage in woven CFRP laminates subjected to low velocity impacts

    Science.gov (United States)

    Ullah, H.; Abdel-Wahab, A. A.; Harland, A. R.; Silberschmidt, V. V.

    2012-08-01

    Carbon fabric-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution in these materials affects both their in-service properties and performance that can deteriorate with time. These processes need adequate means of analysis and investigation, the major approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in woven composite laminates due to low-velocity dynamic out-of-plane bending. Experimental tests are carried out to characterise the behaviour of such laminates under large-deflection dynamic bending in un-notched specimens in Izod tests using a Resil Impactor. A series of low-velocity impact tests is carried out at various levels of impact energy to assess the energy absorbed and force-time response of CFRP laminates. X-ray micro computed tomography (micro-CT) is used to investigate material damage modes in the impacted specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply delamination and intra-ply delamination, such as tow debonding and fabric fracture, were the prominent damage modes.

  12. Superconducting accelerating structures for very low velocity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; /Argonne; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  13. Design of low velocity-spread cusp guns for axis encircling beams

    International Nuclear Information System (INIS)

    Lawson, W.

    1987-01-01

    The design of a novel electron gun suitable for intense beam cyclotron resonance devices is introduced here. An annular Pierce-type gun is used in conjunction with an unbalanced nonadiabatic field reversal and an adiabatic compression region to produce an axis-encircling beam. This beam is ideally suited for interaction with electromagnetic waves that have strong on-axis electric fields (e.g., the TE 0 /sub 11/ mode). Low velocity spreads are achieved by utilizing the beam self-fields in the compression region and by focusing in the Pierce gun

  14. Fatigue Performance of Composite Laminates After Low-velocity Impact

    Directory of Open Access Journals (Sweden)

    LIANG Xiao-lin

    2016-12-01

    Full Text Available Compression-compression fatigue tests were carried out on T300/5405 composite laminates after low-velocity impact, compression performance of the laminates with different impact damages was studied together with its fatigue life and damage propagation under different stress levels, then the effects of impact energy, stress level and damage propagation on fatigue life of laminates were discussed. The results indicate that impact damage can greatly reduce the residual strength of laminates; under low fatigue load levels, the higher impact energy is, the shorter the fatigue life of laminates with impact damage will be; damage propagation undergoes two stages during the fatigue test, namely the steady propagation and the rapid propagation, accounting for 80% and 20% of the overall fatigue life, respectively; damage propagation rate decreases with the reduction of stress level.

  15. Study on low velocity detonation phenomena in Nitromethane

    Directory of Open Access Journals (Sweden)

    A Osada

    2016-04-01

    Full Text Available In detonation of an explosive, there are two forms, high velocity detonation(HVD and low velocity detonation (LVD. For example, it is known that thedetonation velocities of methyl nitrate are 6700m/s in HVD and 2500m/s inLVD. In a liquid explosive, the highest pressure of LVD changes with thetype of explosive and conditions, is a few GPa and has destructive powerequivalent to HVD. It is important also for security to get to know the actualcondition of LVD. Moreover, it is important that the performance ofexplosives is completely understood to control HVD, LVD, and deflagration,and to predict the behavior of the explosive.

  16. Modelling low velocity impact induced damage in composite laminates

    Science.gov (United States)

    Shi, Yu; Soutis, Constantinos

    2017-12-01

    The paper presents recent progress on modelling low velocity impact induced damage in fibre reinforced composite laminates. It is important to understand the mechanisms of barely visible impact damage (BVID) and how it affects structural performance. To reduce labour intensive testing, the development of finite element (FE) techniques for simulating impact damage becomes essential and recent effort by the composites research community is reviewed in this work. The FE predicted damage initiation and propagation can be validated by Non Destructive Techniques (NDT) that gives confidence to the developed numerical damage models. A reliable damage simulation can assist the design process to optimise laminate configurations, reduce weight and improve performance of components and structures used in aircraft construction.

  17. Low Velocity Sphere Impact of a Borosilicate Glass

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, Timothy G [ORNL; Ferber, Mattison K [ORNL; Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL

    2012-05-01

    This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials were used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That

  18. Palliatives for Low Velocity Impact Damage in Composite Laminates

    Directory of Open Access Journals (Sweden)

    Mubarak Ali

    2017-01-01

    Full Text Available Fibre reinforced polymer laminated composites are susceptible to impact damage during manufacture, normal operation, maintenance, and/or other stages of their life cycle. Initiation and growth of such damage lead to dramatic loss in the structural integrity and strength of laminates. This damage is generally difficult to detect and repair. This makes it important to find a preventive solution. There has been abundance of research dealing with the impact damage evolution of composite laminates and methods to mitigate and alleviate the damage initiation and growth. This article presents a comprehensive review of different strategies dealing with development of new composite materials investigated by several research groups that can be used to mitigate the low velocity impact damage in laminated composites. Hybrid composites, composites with tough thermoplastic resins, modified matrices, surface modification of fibres, translaminar reinforcements, and interlaminar modifications such as interleaving, short fibre reinforcement, and particle based interlayer are discussed in this article. A critical evaluation of various techniques capable of enhancing impact performance of laminated composites and future directions in this research field are presented in this article.

  19. Role of Equatorial Anomaly in Earthquake time precursive features: A few strong events over West Pacific zone

    Science.gov (United States)

    Devi, Minakshi; Patgiri, S.; Barbara, A. K.; Oyama, Koh-Ichiro; Ryu, K.; Depuev, V.; Depueva, A.

    2018-03-01

    The earthquake (EQ) time coupling processes between equator-low-mid latitude ionosphere are complex due to inherent dynamical status of each latitudinal zone and qualified geomagnetic roles working in the system. In an attempt to identify such process, the paper presents temporal and latitudinal variations of ionization density (foF2) covering 45°N to 35°S, during a number of earthquake events (M > 5.5). The approaches adopted for extraction of features by the earthquake induced preparatory processes are discussed in the paper through identification of parameters like the 'EQ time modification in density gradient' defined by δ = (foF2 max - foF2 min)/τmm, where τmm - time span (in days) between EQ modified density maximum and minimum, and the Earthquake time Equatorial Anomaly, i.e. EEA, one of the most significant phenomenon which develops even during night time irrespective of epicenter position. Based on the observations, the paper presents the seismic time coupling dynamics through anomaly like manifestations between equator, low and mid latitude ionosphere bringing in the global Total Electron Content (TEC) features as supporting indices.

  20. Initial Examination of Low Velocity Sphere Impact of Glass Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

    2012-06-01

    This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) sphere impact testing of two materials from the lithium aluminosilicate family reinforced with different amounts of ceramic particulate, i.e., glass-ceramic materials, SCHOTT Resistan{trademark}-G1 and SCHOTT Resistan{trademark}-L. Both materials are provided by SCHOTT Glass (Duryea, PA). This work is a follow-up to similar sphere impact studies completed by the authors on PPG's Starphire{reg_sign} soda-lime silicate glass and SCHOTT BOROFLOAT{reg_sign} borosilicate glass. A gas gun or a sphere-drop test setup was used to produce controlled velocity delivery of silicon nitride (Si{sub 3}N{sub 4}) spheres against the glass ceramic tile targets. Minimum impact velocities to initiate fracture in the glass-ceramics were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass

  1. Low-velocity impact cratering experiments in granular slopes

    Science.gov (United States)

    Hayashi, Kosuke; Sumita, Ikuro

    2017-07-01

    Low-velocity impact cratering experiments are conducted in sloped granular targets to study the effect of the slope angle θ on the crater shape and its scales. We use two types of granular matter, sand and glass beads, former of which has a larger friction coefficient μs = tanθr , where θr is the angle of repose. Experiments show that as θ increases, the crater becomes shallower and elongated in the direction of the slope. Furthermore the crater floor steepens in the upslope side and a thick rim forms in the downslope side, thus forming an asymmetric profile. High-speed images show that these features are results of ejecta being dispersed farther towards the downslope side and the subsequent avalanche which buries much of the crater floor. Such asymmetric ejecta dispersal can be explained by combining the Z-model and a ballistic model. Using the topographic maps of the craters, we classify crater shape regimes I-III, which transition with increasing θ : a full-rim crater (I), a broken-rim crater (II), and a depression (III). The critical θ for the regime transitions are larger for sand compared to glass beads, but collapse to close values when we use a normalized slope θ^ = tanθ / tanθr . Similarly we derive θ^-dependences of the scaled crater depth, length, width and their ratios which collapse the results for different targets and impact energies. We compare the crater profiles formed in our experiments with deep craters on asteroid Vesta and find that some of the scaled profiles nearly overlap and many have similar depth / length ratios. This suggests that these Vestan craters may also have formed in the gravity regime and that the formation process can be approximated by a granular flow with a similar effective friction coefficient.

  2. Investigating Ultra-low Velocity Zones beneath the Southwestern Pacific

    Science.gov (United States)

    Carson, S. E.; Hansen, S. E.; Garnero, E.

    2017-12-01

    The core mantle boundary (CMB), where the solid silicate mantle meets the liquid iron-nickel outer core, represents the largest density contrast on our planet, and it has long been recognized that the CMB is associated with significant structural heterogeneities. One CMB structure of particular interest are ultra low-velocity zones (ULVZs), laterally-varying, 5-50 km thick isolated patches seen in some locations just above the CMB that are associated with increased density and reduced seismic wave velocities. These variable characteristics have led to many questions regarding ULVZ origins, but less than 40% of the CMB has been surveyed for the presence of ULVZs given limited seismic coverage of the lowermost mantle. Therefore, investigations that sample the CMB with new geometries are critical to further our understanding of ULVZs and their potential connection to other deep Earth processes. The Transantarctic Mountains Northern Network (TAMNNET), a 15-station seismic array that was recently deployed in Antarctica, provides a unique dataset to further study ULVZ structure with new and unique path geometry. Core-reflected ScP and PcP phases from the TAMNNET dataset particularly well sample the CMB in the vicinity of New Zealand in the southwestern Pacific, providing coverage between an area to the north where ULVZ structure has been previously identified and another region to the south, which shows no ULVZ evidence. By identifying and modeling pre- and post-cursor ScP and PcP energy, we are exploring a new portion of the CMB with a goal of better understanding potential ULVZ origins. Our study area also crosses the southern boundary of the Pacific Large Low Shear Velocity Province (LLSVP); therefore, our investigations may allow us to examine the possible relationship between LLSVPs and ULVZs.

  3. X-ray diffuse scattering study of 2 kF and 4 kF anomalies in strongly irradiated TTF-TCNQ

    OpenAIRE

    Forró, L.; Bouffard, S.; Pouget, J.P.

    1984-01-01

    We report an X-ray diffuse scattering study of the CDW fluctuations in strongly irradiated TTF-TCNQ. The 2 kF and 4 kF CDW become onedimensional for 5.0 mol % of introduced defects, even at the lowest temperature (28 K). At the concentration level of 15 mol % the 2 kF anomaly disappears, while a temperature independent 4 kF distortion is stabilized. These results are compared with those for the alloy TTF0.97TSF0.03TCNQ and for TMTSF-DMTCNQ.

  4. Cracking of laminated glass initiated by low velocity impacts

    Energy Technology Data Exchange (ETDEWEB)

    Coward, David Paul

    2001-07-01

    The work presented in this thesis is concerned with the determination of the relationship between low velocity impacts and the failure by cracking of 420mm square, 6.4 mm thick, three ply, laminated glass. An hydraulic test rig has been constructed which allows tests involving impacts with pre-determined velocities, up to 7 m/s, and deflections, up to 4.6mm, to be conducted upon the glass samples. WeibuIl's approach to describing the failure of brittle materials has been adopted. A Weibull cumulative distribution, which relates the probability of failure to the applied stress, has been generated from the experimental data, and the Weibull modulus or flaw density parameter has been determined to be 3.5. The stress intensity factor, K or fracture toughness value, is an indication of the toughness of a material. Glass, as a brittle material would be expected to have a low fracture toughness. Values for K can be determined experimentally, and as a material characteristic should not vary widely, however the value of 0.46 MPa m{sup 1/2} for the fracture toughness, obtained dynamically in this work, appears to differ from those figures determined by others, using quasi-static loading, of between 0.7 and 0.8 MPa m{sup 1/2}. If the value for K determined during quasi-static loading is applicable to this work, then the length of surface cracks in the glass is calculated to be between 55 and 72 x 10{sup -6} m. The stresses generated during the dynamic loading of glass by an impact can be divided into two distinct elements, the stresses produced by the bending of the glass, Ind the stresses generated during the impact. However, although the resulting stresses can be described separately, they have a combined effect upon the glass. The stress combination factor f, is used to describe how the bending stresses and the impact stresses combine to occasion a micro-crack (which may be found on all exposed glass surfaces) to propagate and cause a fracture in the glass. The value

  5. Asymmetric response of the Atlantic Meridional Ocean Circulation to freshwater anomalies in a strongly-eddying global ocean model

    NARCIS (Netherlands)

    Brunnabend, Sandra Esther|info:eu-repo/dai/nl/371740878; Dijkstra, Henk A.|info:eu-repo/dai/nl/073504467

    2017-01-01

    The Atlantic Meridional Overturning Circulation (AMOC) responds sensitively to density changes in regions of deepwater formation. In this paper, we investigate the nonlinear response of the AMOC to large amplitude freshwater changes around Greenland using a strongly-eddying global ocean model. Due

  6. Simulation and low velocity impact testing on confined explosives

    NARCIS (Netherlands)

    Scholtes, J.H.G.; Verbeek, H.J.

    2010-01-01

    TNO Defence Security and Safety, performs in depth research in energetic material responses to several Insensitive Munitions (IM) stimuli like cook-off, bullet-fragment impact and shaped charge impact. The response of energetic materials to these stimuli depends strongly on the properties of these

  7. Ambient Noise Tomography of Southern California Images Dipping San Andreas-Parallel Structure and Low-Velocity Salton Trough Mantle

    Science.gov (United States)

    Barak, S.; Klemperer, S. L.; Lawrence, J. F.

    2014-12-01

    Ambient noise tomography (ANT) images the entire crust but does not depend on the spatial and temporal distribution of events. Our ANT high-resolution 3D velocity model of southern California uses 849 broadband stations, vastly more than previous studies, and four years of data, 1997-1998, 2007, and 2011, chosen to include our own broadband Salton Seismic Imaging Project, a 40-station transect across the Salton Trough, as well as other campaign stations in both Mexico and the U.S.A., and permanent stations. Our shear-wave model has 0.05° x 0.05° lateral and 1 km vertical blocks. We used the Harvard Community Velocity Model (CVM-H) as the initial model for the inversion. We show significant differences relative to the CVM-H model, especially in the lower crust and upper mantle. We observe prominent low-velocity anomalies in the upper mantle under the Salton Buttes and Cerro Prieto geothermal fields, indicating high-temperatures and possibly partial-melt. Similar low-velocity zones have been previously observed along the Gulf of California. We also observe vertical to gradually dipping lateral velocity contrasts in the lower crust under the southern part of the San Andreas Fault. The east to northeast dip may represent crustal fabric sheared by movement of the Pacific plate under the North American plate prior to the initiation of transform motion.

  8. A Low-velocity Finger from Iceland beneath Southern Scandinavia - the Key to Understanding Neogene Uplift?

    Science.gov (United States)

    Weidle, C.; Maupin, V.

    2007-12-01

    A model of upper mantle S-wave velocity beneath northwestern Europe is presented, based on a tomography of regional surface wave observations. Data from international and, more importantly, regional data archives (including temporary deployments) were used to measure group velocities for both Love and Rayleigh surface waves. The procedure for data selection, group velocity measurements and inversion for group velocity 2-D maps follows closely the one described by Levshin et al. (GJI, 170, 441-459, 2007). Our new set of group velocity maps differs significantly from global reference maps, enhancing many details and amplitudes of group velocity variations in the study region. We then apply a linear inversion scheme to invert for 1-D shear wave velocity profiles which are assembled to a 3-D model. By choosing conservative regularization parameters in the 2-D inversion we ensure the smoothness of the group velocity maps and the resulting 3-D shear wave speed model. To account for the different tectonic regimes in the study region, we compare inversions with 3 different reference models (pure 1-D, 3-D crust / 1-D mantle and pure 3-D) to investigate the sensitivity of the 1-D inversions to inaccuracies in crustal models. We find that all three models are consistent at depths below 90 km and the resulting models deviate only slightly from each other, mostly in amplitudes. We image an intriguing low-velocity anomaly extending from the Iceland plume domain across the north Atlantic beneath southern Scandinavia between 70-150 km depth. Beneath southern Norway, the negative perturbations reach a maximum of up to 13 % w.r.t. ak135 and a shallowing of the anomaly is indicated. This observation could explain the sustained uplift of southern Scandinavia in Neogene times, but the mechanisms are yet undetermined. Furthermore, our upper mantle model reveals good alignment to ancient plate boundaries and first-order crustal fronts around the triple junction of the Baltica

  9. Comparison of different methods for the determination of dynamic characteristics of low velocity anemometers

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Popiolek, Z.

    2004-01-01

    different and insufficient for describing the frequency response of all low velocity thermal anemometers. Therefore the upper frequency, determined in tests with sinusoidal velocity fluctuations, is recommended to be used in indoor climate standards as a single parameter describing the dynamic......Three methods for determining the dynamic characteristics of low velocity thermal anemometers were compared. They were: step-up velocity change and step-down velocity change methods and a method based on sinusoidal type velocity fluctuations. Two low velocity thermal anemometers...... with omnidirectional velocity sensors were tested. The results identify differences in frequency response of low velocity anemometers determined by the three methods. The time constant and the response time determined by the step-up velocity change method and the step-down velocity change method may be substantially...

  10. A Comparison of Quasi-Static Indentation Testing to Low Velocity Impact Testing

    Science.gov (United States)

    Nettles, Alan T.; Douglas, Michael J.

    2001-01-01

    The need for a static test method for modeling low-velocity foreign object impact events to composites would prove to be very beneficial to researchers since much more data can be obtained from a static test than from an impact test. In order to examine if this is feasible, a series of static indentation and low velocity impact tests were carried out and compared. Square specimens of many sizes and thickness were utilized to cover the array of types of low velocity impact events. Laminates with a n/4 stacking sequence were employed since this is by the most common type of engineering laminate. Three distinct flexural rigidities under two different boundary conditions were tested in order to obtain damage due to large deflections, contact stresses and both to examine if the static indentation-impact comparisons are valid under the spectrum of damage modes that can be experienced. Comparisons between static indentation and low velocity impact tests were based on the maximum applied transverse load. The dependent parameters examined included dent depth, back surface crack length, delamination area and to a limited extent, load-deflection behavior. Results showed that no distinct differences could be seen between the static indentation tests and the low velocity impact tests, indicating that static indentation can be used to represent a low velocity impact event.

  11. A Low Velocity Zone along the Chaochou Fault in Southern Taiwan: Seismic Image Revealed by a Linear Seismic Array

    Directory of Open Access Journals (Sweden)

    Hsin-Chieh Pu

    2010-01-01

    Full Text Available The Chaochou fault is one of the major boundary faults in southern Taiwan where strong convergence has taken place between the Eurasian and Philippine Sea plates. The surface fault trace between the Pingtung plain and the Central Range follows a nearly N-S direction and stretches to 80 km in length. In order to examine the subsurface structures along the Chaochou fault, a linear seismic array with 14 short-period stations was deployed across the fault to record seismic data between August and December 2001. Detailed examination of seismic data generated by 10 local earthquakes and recorded by the linear array has shown that the incidence angles of the first P-waves recorded by several seismic stations at the fault zone were significantly larger than those located farther away from the fault zone. This difference might reflect the lateral variation of velocity structures across the Chaochou fault. Further examination of ray-paths of seismic wave propagation indicates that a low-velocity zone along the Chaochou fault is needed to explain the significant change in incidence angles across the fault zone. Although we do not have adequate information to calculate the exact geometry of the fault zone well, the variation in incidence angles across the fault can be explained by the existence of a low-velocity zone that is about 3 km in width on the surface and extends downward to a depth of 5 km. The low-velocity zone along the Chaochou fault might imply that the fault system consists of several splay faults on the hanging wall in the Central Range.

  12. Tracking of Thermal Infrared Anomaly before One Strong Earthquake-In the Case of Ms6.2 Earthquake in Zadoi, Qinghai on October 17th, 2016

    Science.gov (United States)

    Zhang, Xuan; Zhang, Yuansheng; Tian, Xiufeng; Zhang, Qiaoli; Tian, Jie

    2017-10-01

    The detection and tracking process of thermal infrared anomaly before Ms6.2 earthquake in Zadio, Qinghai on October 17th, 2016, are reviewed and analyzed; then the different characteristics of thermal infrared brightness temperature data before this earthquake is described in details. According to these characteristics, the tracking process of thermal anomaly is divided into four stages, respectively identification stage, pre-judgment stage, tracking and approaching stage and verification stage. The anomaly forms and turning signals focused in each stage can provide clear indication information for earthquake pre-judgment; finally, the prediction efficiency and technical issues of this method are illustrated and discussed.

  13. Hot-Wire Calibration at Low Velocities: Revisiting the Vortex Shedding Method

    Directory of Open Access Journals (Sweden)

    Sohrab S. Sattarzadeh

    2013-01-01

    Full Text Available The necessity to calibrate hot-wire probes against a known velocity causes problems at low velocities, due to the inherent inaccuracy of pressure transducers at low differential pressures. The vortex shedding calibration method is in this respect a recommended technique to obtain calibration data at low velocities, due to its simplicity and accuracy. However, it has mainly been applied in a low and narrow Reynolds number range known as the laminar vortex shedding regime. Here, on the other hand, we propose to utilize the irregular vortex shedding regime and show where the probe needs to be placed with respect to the cylinder in order to obtain unambiguous calibration data.

  14. Low velocity collisions of porous planetesimals in the early solar system

    Science.gov (United States)

    de Niem, D.; Kührt, E.; Hviid, S.; Davidsson, B.

    2018-02-01

    The ESA Rosetta mission has shown that Comet 67P/Churuymov-Gerasimenko is bi-lobed, has a high average porosity of around 70%, does not have internal cavities on size scales larger than 10 m, the lobes could have individual sets of onion shell-like layering, and the nucleus surface contains 100 m-scale cylindrical pits. It is currently debated whether these properties are consistent with high-velocity collisional evolution or if they necessarily are surviving signatures of low-velocity primordial accretion. We use an Eulerian hydrocode to study collisions between highly porous bodies of different sizes, material parameters and relative velocities with emphasis on 5-100 m/s to characterize the effects of collisions in terms of deformation, compaction, and heating. We find that accretion of 1 km cometesimals by 3 km nuclei at 13.5 m/s flattens and partially buries the cometesimal with ∼ 1% reduction of the bulk porosity. This structure locally becomes more dense but the global effect of compaction is minor, suggesting that low-velocity accretion does not lead to a 'bunch of grapes' structure with large internal cavities but a more homogeneous interior, consistent with Rosetta findings. The mild local compaction associated with accretion is potentially the origin of the observed nucleus layering. In 2D axially symmetric impacts hit-and-stick collisions of similarly-sized nuclei are possible at velocities up to 30 m/s where deformation becomes severe. The bulk porosity is reduced significantly, even at 30-50 m/s relative velocity. To avoid hit-and-run collisions the impact angle must be less than 35°-45° from the surface normal at 10 m/s, and even smaller at higher velocities. Impact heating is insignificant. We find that the small cross section of the 67P neck may require a ≤ 5 m/s impact, unless the cohesion exceeds 10 kPa. We conclude that bi-lobe nucleus formation is possible at velocities typically discussed in hierarchical growth scenarios. Impacts of a 7 m

  15. A zero-gravity instrument to study low velocity collisions of fragile particles at low temperatures

    NARCIS (Netherlands)

    Salter, D. M.; Heisselmann, D.; Chaparro, G.; van der Wolk, G.; Reissaus, P.; Borst, A. G.; Dawson, R. W.; de Kuyper, E.; Drinkwater, G.; Gebauer, K.; Hutcheon, M.; Linnartz, H.; Molster, F. J.; Stoll, B.; van der Tuijn, P. C.; Fraser, H. J.; Blum, J.

    We discuss the design, operation, and performance of a vacuum setup constructed for use in zero (or reduced) gravity conditions to initiate collisions of fragile millimeter-sized particles at low velocity and temperature. Such particles are typically found in many astronomical settings and in

  16. Lithospheric low-velocity zones associated with a magmatic segment of the Tanzanian Rift, East Africa

    Science.gov (United States)

    Plasman, M.; Tiberi, C.; Ebinger, C.; Gautier, S.; Albaric, J.; Peyrat, S.; Déverchère, J.; Le Gall, B.; Tarits, P.; Roecker, S.; Wambura, F.; Muzuka, A.; Mulibo, G.; Mtelela, K.; Msabi, M.; Kianji, G.; Hautot, S.; Perrot, J.; Gama, R.

    2017-07-01

    Rifting in a cratonic lithosphere is strongly controlled by several interacting processes including crust/mantle rheology, magmatism, inherited structure and stress regime. In order to better understand how these physical parameters interact, a 2 yr long seismological experiment has been carried out in the North Tanzanian Divergence (NTD), at the southern tip of the eastern magmatic branch of the East African rift, where the southward-propagating continental rift is at its earliest stage. We analyse teleseismic data from 38 broad-band stations ca. 25 km spaced and present here results from their receiver function (RF) analysis. The crustal thickness and Vp/Vs ratio are retrieved over a ca. 200 × 200 km2 area encompassing the South Kenya magmatic rift, the NTD and the Ngorongoro-Kilimanjaro transverse volcanic chain. Cratonic nature of the lithosphere is clearly evinced through thick (up to ca. 40 km) homogeneous crust beneath the rift shoulders. Where rifting is present, Moho rises up to 27 km depth and the crust is strongly layered with clear velocity contrasts in the RF signal. The Vp/Vs ratio reaches its highest values (ca. 1.9) beneath volcanic edifices location and thinner crust, advocating for melting within the crust. We also clearly identify two major low-velocity zones (LVZs) within the NTD, one in the lower crust and the second in the upper part of the mantle. The first one starts at 15-18 km depth and correlates well with recent tomographic models. This LVZ does not always coexist with high Vp/Vs ratio, pleading for a supplementary source of velocity decrease, such as temperature or composition. At a greater depth of ca. 60 km, a mid-lithospheric discontinuity roughly mimics the step-like and symmetrically outward-dipping geometry of the Moho but with a more slanting direction (NE-SW) compared to the NS rift. By comparison with synthetic RF, we estimate the associated velocity reduction to be 8-9 per cent. We relate this interface to melt ponding

  17. Growth of L-band scintillation at anomaly crest station in association with strong TEC gradient: A study covering wide solar activity period

    Science.gov (United States)

    Pathak, K.; Devi, M.; Barbara, A. K.; Zahan, Y.

    2018-01-01

    The paper aims at to study the sources associated with growth of L band scintillation over Guwahati, an Appleton anomaly region. Starting with the analysis of diurnal and seasonal characteristic features of scintillation from a minimum sunspot number (Rz) of 10 to a maximum of 140, the paper shows that scintillations are more likely to develop during high solar activity period. It also highlights the explosive increase in occurrence of scintillation from post sunset to pre midnight hours in vernal equinoctial months when the background TEC is 50% more than on a normal day, accompanied by enhanced TEC decay rate. The role of equatorial anomaly effects through EXB drift processes are brought into discussion as possible sources on the growth of small scale irregularities leading to such scintillations.

  18. An Investigation on Low Velocity Impact Response of Multilayer Sandwich Composite Structures

    Science.gov (United States)

    Jedari Salami, S.; Sadighi, M.; Shakeri, M.; Moeinfar, M.

    2013-01-01

    The effects of adding an extra layer within a sandwich panel and two different core types in top and bottom cores on low velocity impact loadings are studied experimentally in this paper. The panel includes polymer composite laminated sheets for faces and the internal laminated sheet called extra layer sheet, and two types of crushable foams are selected as the core material. Low velocity impact tests were carried out by drop hammer testing machine to the clamped multilayer sandwich panels with expanded polypropylene (EPP) and polyurethane rigid (PUR) in the top and bottom cores. Local displacement of the top core, contact force and deflection of the sandwich panel were obtained for different locations of the internal sheet; meanwhile the EPP and PUR were used in the top and bottom cores alternatively. It was found that the core material type has made significant role in improving the sandwich panel's behavior compared with the effect of extra layer location. PMID:24453804

  19. K-shell ionisation cross sections for W, Au and U by low velocity protons

    International Nuclear Information System (INIS)

    Castro Faria, N.V. de; Freire Junior, F.L.; Montenegro, E.C.; Pinho, A.G. de; Silveira, E.F. da.

    1984-01-01

    Proton-induced K-shell ionisation cross section for W, Au and U by low velocity protons were obtained from thick target measurements. For the first time the lowest incident energy reached a value less than 10 times the binding energy of the K-shell electron (less than 9 times in the case of Au). Possible errors are thoroughly examined and a comparison with other available experimental results and theoretical values is presented and discussed. (Author) [pt

  20. Flowfield characterisation in the wake of a low-velocity heated sphere anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Olim, A.M. [Associacao para o Desenvolvimento da Aerodinamica Industrial (ADAI), Coimbra (Portugal); Riethmuller, M.L. [Von Karman Institute for Fluid Dynamics (VKI), St. Genese (Belgium); Gameiro da Silva, M.C. [Departamento de Engenharia Mecanica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra Polo II, Coimbra (Portugal)

    2002-06-01

    Heated sphere anemometers (HSA) are the most widely used instruments for low-velocity measurements in the heating, ventilation and air-conditioning industry. Experiments were conducted to characterise the flowfield around the spherically shaped sensor and upper probe assembly of a HSA. Particle image velocimetry was the main quantitative experimental technique. Measurements of the flowfield around a HSA probe and a 2:1 scaled-up model were performed in a uniform isothermal axisymmetrical jet air flow at Re around 350, based on sensor diameter, for different pitch angle incident flows. Additionally, extensive flow visualisation studies around scaled-up models of the HSA probe were performed. (orig.)

  1. Accuracy limitations for low velocity measurements and draft assessment in rooms

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Popiolek, Zbigniew J.; Silva, M.G.

    2007-01-01

    . In this paper, the combined impact of error sources on the accuracy of mean speed, standard deviation of speed, and turbulence intensity that may occur during measurements with LVTAs is analyzed. The minimum uncertainty that is realistically achievable in practice is identified. The requirements for low......, the definition of realistic requirements in thermal comfort standards as well as validation of CFD predictions is made possible.......-velocity anemometers prescribed in the present standards are critically reviewed and revised New requirements that will decrease the uncertainty of low-velocity measurements are suggested for inclusion in future ventilation standards. The uncertainty in determination of draft discomfort is defined. Thus...

  2. Dome-like low velocity upwelling in D" beneath Alaska imaged with USArray data

    Science.gov (United States)

    Sun, Daoyuan; Miller, Meghan S.; Helmberger, Don

    2015-04-01

    The lowermost mantle region, D", represents one of the most dramatic thermal and compositional layers within our planet. Global tomographic models display relatively fast patches along the circum-Pacific which are generally attributed to slab-related debris. Most seismic observations for the D" boundary layer come from the lower mantle S wave triplication (Scd). However, the most sampled regions are concentrated beneath Central America, where intensive studies, including migration methods and array analysis, have been accomplished. Beneath Central America, the D" can have a step variation of ~100 km, which argues strong lateral temperature variations or possible chemical variations. However, the commonly used ray paths between South American events and seismic stations in North America sample this sharp boundary azimuthally, which is difficult to model. Here, we exploit the USArray waveform data to examine a sharp transition beneath Alaska. From west to east beneath Alaska, we observe three different types of structures in the D" layer: in the western region we observed a strong Scd phase, which requires a sharp δVS = 2% increase; in the middle region there is no clear Scd phase indicating no D" layer; in the eastern region we observe a strong Scd phase requiring a positive gradient δVS. To explain such strong lateral differences in seismic velocity, we propose a chemical variation. We suggest that the western region represents a "normal" lowermost mantle. In contrast, the eastern region has fast velocities, which appears to influenced by the subducted Pacific slab. In the middle region, we interpret an upwelling structure that disrupts the phase boundary. This is based upon observations of a distinct pattern of travel time delays, waveform distortions, and amplitude patterns which reveal a circular anomaly about 5° across which can be modeled synthetically as a dome about 400 km high with a low shear velocity reduction of ~5%. Numerical modeling indicates that

  3. Imaging pockets and conduits of low velocity material beneath the lithosphere of the Atlas Mountains of Morocco: links to volcanism and orogenesis

    Science.gov (United States)

    Miller, M. S.; Sun, D.; O'Driscoll, L.; Holt, A.; Butcher, A.; Becker, T. W.; Diaz Cusi, J.; Thomas, C.

    2014-12-01

    The Atlas Mountains of Morocco have unusually high topography, with no apparent deep crustal root, and regions of localized Cenozoic alkaline volcanism. Previous seismic imaging and geophysical studies have implied a hot mantle upwelling as the source of the volcanism and high elevation, but the existence and physical properties of such an upwelling are debated. Recent temporary deployments of over 100 broadband seismometers that extended across Morocco as part of the PICASSO, Morocco-Münster, and IberArray experiments along with select permanent stations have provided a dataset to image the detailed mantle and lithospheric structure beneath the Atlas. We present results from S receiver functions (SRF), shear wave splitting, waveform modeling, and geodynamic models that help constrain the tectonic evolution of the Atlas and the localized alkaline volcanism. The receiver functions show that the lithosphere is thin (~65 km) beneath the Atlas, but thickens (~105 km) over a very short length scale at the flanks of the mountains and near the Quaternary volcanoes. These changes in lithospheric thickness also correspond to dramatic decreases in delay times inferred from S and SKS splitting observations. SRFs also indicate a broad, low seismic velocity anomaly (~150 km) below the shallow lithosphere that extends along much of the Atlas and beneath the Anti-Atlas and correlates with the location of Pliocene-Quaternary magmatism. Waveform analysis from the linear array across the Middle and High Atlas constrains the position, shape, and physical characteristics of a localized, low velocity conduit that extends up from the uppermost mantle (~200 km). The shape, position and temperature of the imaged low velocity anomaly, offsets in the lithosphere-asthenosphere boundary, and correlation with mantle flow inferred from shear wave splitting suggest that the unusually high topography of the Atlas Mountains is due to active mantle support.

  4. Atomic collision experiments utilizing low-velocity, highly-charged ion beams

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Meron, M.

    1983-01-01

    Intense beams of highly-stripped ions are now routinely produced at low velocities using the Brookhaven dual MP-tandems in a unique four-stage accel/decel mode. This mode of operation combines three stages of acceleration, stripping at high energy, and one stage of deceleration to near-zero velocity. To date, experiments have used 10-100 nA beams of bare and few-electron heavy ions at energies as low as 0.2 MeV/amu, and upgrades of the facility should push the lower limit below 0.1 MeV/amu. Recent experiments, such as measurements of charge transfer and x-ray production for S 6 - 16 + on He and Ar at 6-20 MeV and P(b) measurements for MO x-rays produced in Cl 16 + + Ar collisions at 20, 10 and 5 MeV have demonstrated the usefulness of highly-stripped, low-velocity projectiles. These experiments and a few possibilities for future experiments are discussed

  5. Experimental and Numerical Investigations of Textile Hybrid Composites Subjected to Low Velocity Impact Loadings

    Directory of Open Access Journals (Sweden)

    Gautam S. Chandekar

    2014-01-01

    Full Text Available In the present study experimental and numerical investigations were carried out to predict the low velocity impact response of four symmetric configurations: 10 ply E Glass, 10 ply AS4 Carbon, and two Hybrid combinations with 1 and 2 outer plies of E Glass and 8 and 6 inner plies of Carbon. All numerical investigations were performed using commercial finite element software, LS-DYNA. The test coupons were manufactured using the low cost Heated Vacuum Assisted Resin Transfer Molding (H-VARTM© technique. Low velocity impact testing was carried out using an Instron Dynatup 8250 impact testing machine. Standard 6 × 6 Boeing fixture was used for all impact experiments. Impact experiments were performed over progressive damage, that is, from incipient damage till complete failure of the laminate in six successive impact energy levels for each configuration. The simulation results for the impact loading were compared with the experimental results. For both nonhybrid configurations, it was observed that the simulated results were in good agreement with the experimental results, whereas, for hybrid configurations, the simulated impact response was softer than the experimental response. Maximum impact load carrying capacity was also compared for all four configurations based on their areal density. It was observed that Hybrid262 configuration has superior impact load to areal density ratio.

  6. Fiber optic interrogation systems for hypervelocity and low velocity impact studies

    Science.gov (United States)

    Jackson, D. A.; Cole, M. J.

    2012-03-01

    The aim of this project was to develop non-contact fiber optic based displacement sensors to operate in the harsh environment of a "light gas gun" (LGG), which can "fire" small particles at velocities ranging from 1 km/s-8.4 km/s. The LGG is used extensively for research in aerospace to analyze the effects of high speed impacts on materials. Ideally the measurement should be made close to the center of the impact to minimize corruption of the data from edge effects and survive the impact. We chose to develop a non-contact "pseudo" confocal intensity sensor, which demonstrated resolution comparable with conventional polyvinylidene fluoride (PVDF) sensors combined with high survivability and low cost. A second sensor was developed based on "fiber Bragg gratings" (FBG) to enable a more detailed analysis of the effects of the impact, although requiring contact with the target the low weight and very small contact area of the FBG had minimal effect on the dynamics of the target. The FBG was mounted either on the surface of the target or tangentially between a fixed location. The output signals from the FBG were interrogated in time by a new method. Measurements were made on carbon fiber composite plates in the LGG and on low velocity impact tests. The particle momentum for the low velocity impact tests was chosen to be similar to that of the particles used in the LGG.

  7. Ultrasonic detection of spall damage nucleation under low-velocity repeated impact

    Directory of Open Access Journals (Sweden)

    Watanabe T.

    2012-08-01

    Full Text Available Repeated plate impact testing with impact stress well below the threshold spall-stress (2.6 GPa on medium carbon steel was carried out to the identical target plate by impacting the flyer plate. Occurrence of spall damage under low-velocity repeated impact was evaluated nondestructively with a low frequency scanning acoustic microscope. We observed the spall damage distribution by the B- and C-scan images. In order to initiate the spall damage (voids in a ductile material or cracks in a brittle one the particular value of threshold spall-stress should be exceeded what already belongs to a commonly accepted knowledge. Generally, the spall damage development is dependent on the amplitude and the duration of the stress pulse. If the stress is high and duration is long enough to create tensile failure of material, the voids or cracks nucleate along the spall plane, and consequently, they form macrocracks. Therefore, the spall damage does not create when the first impact stress is less than the threshold spall-stress. However, after the fifth low-velocity repeated impact test, the generation of the spall damage was detected, even if the impact stress (1.1–1.7 GPa was lower than the threshold spall-stress (2.6 GPa.

  8. Low-velocity impact damage of woven fabric composites: Finite element simulation and experimental verification

    International Nuclear Information System (INIS)

    Hassan, M.A.; Naderi, S.; Bushroa, A.R.

    2014-01-01

    Highlights: • Low-velocity impact test on GFRP with different energy levels and thicknesses. • Using force–deflection curve to determine critical energy for penetration threshold. • Reflection of damage processes to different type of diagrams. • Significant influence of Initial energy and thickness on dynamic response of plates. • Good agreements between experimental and FEM models for the force history data. - Abstract: This paper addresses the response of Glass Fiber Reinforced Plastic laminates (GFRPs) under low-velocity impact. Experimental tests were performed according to ASTM: D5628 for different initial impact energy levels ranging from 9.8 J to 29.4 J and specimen thicknesses of 2, 3 and 4 mm. The impact damage process and contact stiffness were studied incrementally until a perforation phase of the layered compounds occurred, in line with a force–deflection diagram and imaging of impacted laminates. The influence that impact parameters such as velocity and initial energy had on deflection and damage of the test specimens was investigated. Finite Element Simulation (FES) was done using MSC. MARC® was additionally carried out to understand the impact mechanism and correlation between these parameters and the induced damage. The simulation and experimental results reached good accord regarding maximum contact force and contact time with insignificant amount of damage

  9. Atomic collision experiments utilizing low-velocity, highly-charged ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, B.M.; Jones, K.W.; Meron, M.

    1982-01-01

    Intense beams of highly-stripped ions are now routinely produced at low velocities using the Brookhaven dual MP-tandens in a unique four-stage accel/decel mode. This mode of operation combines three stages of acceleration, stripping at high energy, and one stage of deceleration to near-zero velocity. To date, experiments have used 10-100 nA beams of bare and few-electron heavy ions at energies as low as 0.2 MeV/amu, and upgrades of the facility should push the lower limit below 0.1 MeV/amu. Recent experiments, such as measurements of charge transfer and x-ray production for S/sup 6-16+/ on He and Ar at 6 to 20 MeV and P(b) measurements for MO x-rays produced in Cl/sup 16 +/ + Ar collisions at 20, 10, and 5 MeV have demonstrated the usefulness of highly-stripped, low-velocity projectiles. These experiments and a few possibilities for future experiments are discussed.

  10. Experimental study of low-velocity impact on foam-filled Kraft paper honeycomb structure

    Science.gov (United States)

    Kadir, N. Abd; Aminanda, Y.; Ibrahim, M. S.; Mokhtar, H.

    2018-01-01

    Low-velocity impact tests of unfilled and foam-filled Kraft paper honeycomb are carried out to investigate the effect of foam, indenter size and location of indentation on maximum or peak force and energy absorption capability. In this study, three indenter sizes (10mm, 12mm, 15mm) and three different locations of indentation (vertical edge, double wall and single wall) were used and compared. The test results show that the foam is given a significant increment of peak force and specific energy absorption to the honeycomb structure subjected to indentation load. The peak force and energy absorption capability also effected by indenter size which due to the contact area of indentation. As for the location of indentation, vertical edge gives highest peak force and energy absorption by the fact that vertical edge is the intersection of three walls of honeycomb cell.

  11. Modified method of perturbed stationary states. II. Semiclassical and low-velocity quantal approximations

    International Nuclear Information System (INIS)

    Green, T.A.

    1978-10-01

    For one-electron heteropolar systems, the wave-theoretic Lagrangian of Paper I 2 is simplified in two distinct approximations. The first is semiclassical; the second is quantal, for velocities below those for which the semiclassical treatment is reliable. For each approximation, unitarity and detailed balancing are discussed. Then, the variational method as described by Demkov is used to determine the coupled equations for the radial functions and the Euler-Lagrange equations for the translational factors which are part of the theory. Specific semiclassical formulae for the translational factors are given in a many-state approximation. Low-velocity quantal formulae are obtained in a one-state approximation. The one-state results of both approximations agree with an earlier determination by Riley. 14 references

  12. A novel VSP method for fault proximity detection using low velocity waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Cao, S.; Greenhalgh, S. (Flinders University of South Australia, Adelaide, SA (Australia). School of Earth Sciences)

    A potentially useful seismic technique for fault detection has been tested by finite-difference modelling of elastic wave propagation in heterogeneous media. It employs a surface-to-borehole vertical seismic profiling (VSP) geometry. Geophones are lowered into the borehole and seismic sources are fired at or near the ground surface. Small disruptions to a low-velocity zone (LVZ) bounded by higher velocity media can be detected by the technique with the analysis of seismic arrival patterns recorded at geophones in a nearby borehole. A disruption in the LVZ will act as a secondary source when an incident wave strikes it. Some of the energy radiated from the secondary source can be captured by the LVZ and will propagate as guided waves. Both offset VSP and walkaway VSP recording geometries are considered for the numerical simulation. In the offset geometry, a spread of geophones is deployed in the borehole around the coal seam while a single source is fired. Both disrupted and continuous LVZ models have been considered for numerical simulations. Explosive sources (P-wave energy only) are used. Synthetic seismograms show that channel waves can be excited by the scattered energy at a LVZ disruption. The maximum amplitude of the channel waves is comparable to those of direct body waves, which clearly indicates that the disruption in the LVZ can act as an efficient source to generate guided waves. In the walkaway VSP geometry, a single geophone is fixed in the LVZ and a spread of sources is fired on the surface away from the borehole. Synthetic seismograms demonstrate that the apex of the channel-wave arrivals pinpoints the location of the disruption of the LVZ for a layered model. Although this technique has parallels with in-seam seismic coal exploration, it does not require that the source be placed within the low-velocity channel. This method is equally applicable to any exploration target which relates to a LVZ. 7 refs., 4 figs.

  13. Numerical and Experimental Low-Velocity Impact Behaivor of Sandwich Plates with Viscoelastic Core

    Directory of Open Access Journals (Sweden)

    Soroush Sadeghnejad

    2016-03-01

    Full Text Available A numerical and experimental low-velocity impact behavior of sandwich plates have been presently studied with regard to the compressibility and viscoelasticity features of their cores. Face sheets were assumed to be anisotropic composites or isotropic aluminum materials and a viscoelastic behavior has been considered for core. The boundary conditions are assumed to be simply supported or rigid. Abaqus, as FEM software, and its python script programming feature, have been used to model the specimens. To model hyper-viscoelastic nonlinear behavior of the core, Ogden hyper-foam elasticity and Prony series approach are manipulated. To solve the numerical problem, dynamic explicit solver option with sufficient solving amplitude has been used. Prony series have been used to model the core time-dependent behavior. In conjunction with a simple indentation experiment, FEM used to formulate a novel method for finding the Prony series coefficients. By performing some low-velocity impact experiments, the impact force and displacement of the composite sandwich plates have been investigated. The results indicate that increasing the structural damping increases the contact time and missing energy and decreases the stored energy of the system. The structures with composite face sheets have a minimum ratio of upper face sheet displacement to lower face sheet displacement in comparison to those with the isotropic face sheets. Impact behavior of isotropic face sheet specimens are more flattened than that of the composite face sheets. In addition, the specific energy stored in the sandwich plates with composite face sheets, on different supports, is greater than that stored in the aluminum face sheets.

  14. Effect of low velocity impact damage on the natural frequency of composite plates

    Science.gov (United States)

    Chok, E. Y. L.; Majid, D. L. A. A.; Harmin, M. Y.

    2017-12-01

    Biodegradable natural fibers have been suggested to replace the hazardous synthetic fibers in many aerospace applications. However, this notion has been limited due to their low mechanical properties, which leads to the idea of hybridizing the two materials. Many aircraft components such as radome, aft body and wing are highly susceptible to low velocity impact damage while in-service. The damages degrade the structural integrity of the components and change their dynamic characteristics. In worst case scenario, the changes can lead to resonance, which is an excessive vibration. This research is conducted to study the dynamic characteristic changes of low velocity impact damaged hybrid composites that is designed for aircraft radome applications. Three materials, which are glass fiber, kenaf fiber and kenaf/glass fiber hybrid composites, have been impacted with 3J, 6J and 9J of energy. Cantilevered and also vertically clamped boundary conditions are used and the natural frequencies are extracted for each of the specimens. The obtained results show that natural frequency decreases with increasing impact level. Cantilevered condition is found to induce lower modes due to the gravitational pull. To eliminate mass and geometrical effects, normalized modes are computed. Among the three materials considered, glass fiber composites have displayed the highest normalized frequency that reflects on its higher stiffness compared to the other two materials. As the damage level is increased, glass fiber composites have shown the highest frequency reduction to a maximum of 35% while kenaf composites have the least frequency reduction in the range of 1 - 18%. Thus, kenaf fiber is taken to be helpful in stalling the damage progression and reducing the effect of damage. This has been proven when the percentage frequency decrement shown by kenaf/glass fiber composite lies between glass fiber and kenaf fiber composites.

  15. Experimental and Numeral Investigation on X-cor Sandwich Structure under Low-velocity Impact

    Directory of Open Access Journals (Sweden)

    ZHU Fei

    2017-04-01

    Full Text Available X-cor sandwich is a new kind of foam sandwich reinforced by Z-pin techniques. Under low velocity impact damage, failure mechanism of X-cor sandwich structure is complex. Failure behavior of X-cor sandwich structure at different energy stages was analyzed, and the effects of the volume fraction of Z-pin implant and the density of the foam core on the failure behavior were also discussed. Z-pin diameter of specimens in low speed impact test was 0.5 mm, and the implantation angle was 22°, and the type of foam and Z-pin implant volume fraction in the experiment was variable .The results show that under 6 J impact energy, the impact energy is mainly absorbed by the panel’s delamination. The sandwich contained Z-pin is beneficial to reduce the delamination area, while the delamination area of blank sample increases by 45.1%. The foam density has little effect on the delamination area. The Z-pin fails under 12 J impact energy. The residual compressive strength ratio increases first and then decreases with the increase of volume fraction of Z-pin. The sample has the highest residual compressive strength ratio when the volume fraction reaches 0.42%. As the foam density increases, the residual compressive strength ratio increases. When the energy reaches 18 J, shear crack appears in the foam core, and the crack absorbs most of the energy. The weaker the foam core, the larger the residual compressive strength ratio is, and the more the volume fraction of Z-pin implanted, the lower the residual compressive strength ratio is. The low velocity impact model is also established by numerical simulation, and the result of impact damage is directly transferred and applied to study the residual strength model; the result obtained is 25%~29% higher than the experimental value.

  16. An experimental study of low velocity impacts into granular material in reduced gravity

    Science.gov (United States)

    Murdoch, Naomi; Avila Martinez, Iris; Sunday, Cecily; Cherrier, Olivier; Zenou, Emanuel; Janin, Tristan; Cadu, Alexandre; Gourinat, Yves; Mimoun, David

    2016-04-01

    The granular nature of asteroid surfaces, in combination with the low surface gravity, makes it difficult to predict lander - surface interactions from existing theoretical models. Nonetheless, an understanding of such interactions is particularly important for the deployment of a lander package. This was demonstrated by the Philae lander, which bounced before coming to rest roughly 1 kilometer away from its intended landing site on the surface of comet 67P/Churyumov-Gerasimenko before coming to rest (Biele et al., 2015). In addition to being important for planning the initial deployment, information about the acceleration profile upon impact is also important in the choice of scientific payloads that want to exploit the initial landing to study the asteroid surface mechanical properties (e.g., Murdoch et al., 2016). Using the ISAE-SUPAERO drop tower, we have performed a series of low-velocity collisions into granular material in low gravity. Reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use an Atwood machine, or a system of pulleys and counterweights. In reducing the effective surface acceleration of the granular material, the confining pressure will be reduced, and the properties of the granular material will become more representative of those on an asteroid's surface. In addition, since both the surface and projectile are falling, the projectile requires a minimum amount of time to catch the surface before the collision begins. This extended free-fall increases the experiment duration, making it easier to use accelerometers and high-speed cameras for data collection. The experiment is built into an existing 5.5 m drop-tower frame and has required the custom design of all components, including the projectile, surface sample container, release mechanism and deceleration system (Sunday et al., 2016

  17. Peculiarities of motion at low velocities. Motion in space and motion in time

    International Nuclear Information System (INIS)

    Zheludev, I.S.

    1982-01-01

    Motion referred to certain space coordinate x and described by space-time relationships of the special theory of relativity, is interpreted as a motion in space. The concept of motion referred to the certain moment of time t, is introduced and called as a motion in time. Space-time relationships for the latter case are followed from the transformations x→t, t→x, v→α (α=1/v, mod(αsub(t))=mod(vsub(s))), c→αsub(max)=1/c 0 , mod(c)=mod(αsub(max)). The invariable characteristic of inertial motion in time is determined by a given equation. The peculiar features of motion in time are found at low velocities (α→αsub(max)). The combined approach is based on both limiting quantities c and αsub(max). If the space coordinate x is measured through motion in space and time t through motion in time (parity frame-reference), all inertial movements have the same velocity, velocity of self-divergence v 0 = √cc 0 . There is no distortion of spatial and temporal scales when the motion is described in the parity frame-reference. The use of different intervals characterizing invariable quantities of inertial motion in space and times makes it possible to understand some problems of cosmological expansion of non-interacting galaxies (Hubble's law v = HR and, the ''low of limited distances'', v = R/t characterizing linear dimension of Universe etc.). (Auth.)

  18. Verification and Validation of Carbon-Fiber Laminate Low Velocity Impact Simulations.

    Energy Technology Data Exchange (ETDEWEB)

    English, Shawn Allen; Nelson, Stacy Michelle; Briggs, Timothy; Brown, Arthur A.

    2014-10-01

    Presented is a model verification and validation effort using low - velocity impact (LVI) of carbon fiber reinforced polymer laminate experiments. A flat cylindrical indenter impacts the laminate with enough energy to produce delamination, matrix cracks and fiber breaks. Included in the experimental efforts are ultrasonic scans of the damage for qualitative validation of the models. However, the primary quantitative metrics of validation are the force time history measured through the instrumented indenter and initial and final velocities. The simulations, whi ch are run on Sandia's Sierra finite element codes , consist of all physics and material parameters of importance as determined by a sensitivity analysis conducted on the LVI simulation. A novel orthotropic damage and failure constitutive model that is cap able of predicting progressive composite damage and failure is described in detail and material properties are measured, estimated from micromechanics or optimized through calibration. A thorough verification and calibration to the accompanying experiment s are presented. Specia l emphasis is given to the four - point bend experiment. For all simulations of interest, the mesh and material behavior is verified through extensive convergence studies. An ensemble of simulations incorporating model parameter unc ertainties is used to predict a response distribution which is then compared to experimental output. The result is a quantifiable confidence in material characterization and model physics when simulating this phenomenon in structures of interest.

  19. On the Behavior of Fiberglass Epoxy Composites under Low Velocity Impact Loading

    Directory of Open Access Journals (Sweden)

    Gautam S. Chandekar

    2010-01-01

    Full Text Available Response of fiberglass epoxy composite laminates under low velocity impact loading is investigated using LS-DYNA®, and the results are compared with experimental analysis performed using an instrumented impact test setup (Instron dynatup 8250. The composite laminates are manufactured using H-VARTM© process with basket weave E-Glass fabrics. Epon 862 is used as a resin system and Epicure-W as a hardening agent. Composite laminates, with 10 layers of fiberglass fabrics, are modeled using 3D solid elements in a mosaic fashion to represent basket weave pattern. Mechanical properties are calculated by using classical micromechanical theory and assigned to the elements using ORTHOTROPIC ELASTIC material model. The damage occurred since increasing impact energy is incorporated using ADVANCED COMPOSITE DAMAGE material model in LS-DYNA®. Good agreements are obtained with the failure damage results in LS-DYNA® and experimental results. Main considerations for comparison are given to the impact load carrying capacity and the amount of impact energy absorbed by the laminates.

  20. Superconducting low-velocity linac for the Argonne positive-ion injector

    International Nuclear Information System (INIS)

    Shepard, K.W.; Markovich, P.K.; Zinkann, G.P.; Clifft, B.; Benaroya, R.

    1989-01-01

    A low-velocity superconducting linac has been developed as part of a positive-ion injector system, which is replacing a 9 MV tandem as the injector for the ATLAS accelerator. The linac consists of an independently phased array of resonators, and is designed to accelerate various ions over a velocity range .008 < v/c < .06. The resonator array is formed of four different types of superconducting interdigital structures. The linac is being constructed in three phases, each of which will cover the full velocity range. Successive phases will increase the total accelerating potential and permit heavier ions to be accelerated. Assembly of the first phase was completed in early 1989. In initial tests with beam, a five-resonator array provided approximately 3.5 MV of accelerating potential and operated without difficulty for several hundred hours. The second phase is scheduled for completion in late 1989, and will increase the accelerating potential to more than 8 MV. 5 refs., 2 figs., 1 tab

  1. Superconducting low-velocity linac for the Argonne positive-ion injector

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Markovich, P.K.; Zinkann, G.P.; Clifft, B.; Benaroya, R.

    1989-01-01

    A low-velocity superconducting linac has been developed as part of a positive-ion injector system, which is replacing a 9 MV tandem as the injector for the ATLAS accelerator. The linac consists of an independently phased array of resonators, and is designed to accelerate various ions over a velocity range .008 < v/c < .06. The resonator array is formed of four different types of superconducting interdigital structures. The linac is being constructed in three phases, each of which will cover the full velocity range. Successive phases will increase the total accelerating potential and permit heavier ions to be accelerated. Assembly of the first phase was completed in early 1989. In initial tests with beam, a five-resonator array provided approximately 3.5 MV of accelerating potential and operated without difficulty for several hundred hours. The second phase is scheduled for completion in late 1989, and will increase the accelerating potential to more than 8 MV. 5 refs., 2 figs., 1 tab.

  2. Low-Velocity Impact Behavior of Sandwich Structures with Additively Manufactured Polymer Lattice Cores

    Science.gov (United States)

    Turner, Andrew J.; Al Rifaie, Mohammed; Mian, Ahsan; Srinivasan, Raghavan

    2018-04-01

    Sandwich panel structures are widely used in aerospace, marine, and automotive applications because of their high flexural stiffness, strength-to-weight ratio, good vibration damping, and low through-thickness thermal conductivity. These structures consist of solid face sheets and low-density cellular core structures, which are traditionally based upon honeycomb folded-sheet topologies. The recent advances in additive manufacturing (AM) or 3D printing process allow lattice core configurations to be designed with improved mechanical properties. In this work, the sandwich core is comprised of lattice truss structures (LTS). Two different LTS designs are 3D-printed using acrylonitrile butadiene styrene (ABS) and are tested under low-velocity impact loads. The absorption energy and the failure mechanisms of lattice cells under such loads are investigated. The differences in energy-absorption capabilities are captured by integrating the load-displacement curve found from the impact response. It is observed that selective placement of vertical support struts in the unit-cell results in an increase in the absorption energy of the sandwich panels.

  3. Measurement of fast-changing low velocities by photonic Doppler velocimetry.

    Science.gov (United States)

    Song, Hongwei; Wu, Xianqian; Huang, Chenguang; Wei, Yangpeng; Wang, Xi

    2012-07-01

    Despite the increasing popularity of photonic Doppler velocimetry (PDV) in shock wave experiments, its capability of capturing low particle velocities while changing rapidly is still questionable. The paper discusses the performance of short time Fourier transform (STFT) and continuous wavelet transform (CWT) in processing fringe signals of fast-changing low velocities measured by PDV. Two typical experiments are carried out to evaluate the performance. In the laser shock peening test, the CWT gives a better interpretation to the free surface velocity history, where the elastic precursor, main plastic wave, and elastic release wave can be clearly identified. The velocities of stress waves, Hugoniot elastic limit, and the amplitude of shock pressure induced by laser can be obtained from the measurement. In the Kolsky-bar based tests, both methods show validity of processing the longitudinal velocity signal of incident bar, whereas CWT improperly interprets the radial velocity of the shocked sample at the beginning period, indicating the sensitiveness of the CWT to the background noise. STFT is relatively robust in extracting waveforms of low signal-to-noise ratio. Data processing method greatly affects the temporal resolution and velocity resolution of a given fringe signal, usually CWT demonstrates a better local temporal resolution and velocity resolution, due to its adaptability to the local frequency, also due to the finer time-frequency product according to the uncertainty principle.

  4. Effect of temperature on composite sandwich structures subjected to low velocity impact. [aircraft construction materials

    Science.gov (United States)

    Sharma, A. V.

    1980-01-01

    The effect of low velocity projectile impact on sandwich-type structural components was investigated. The materials used in the fabrication of the impact surface were graphite-, Kevlar-, and boron-fibers with appropriate epoxy matrices. The testing of the specimens was performed at moderately low- and high-temperatures as well as at room temperature to assess the impact-initiated strength degradation of the laminates. Eleven laminates with different stacking sequences, orientations, and thicknesses were tested. The low energy projectile impact is considered to simulate the damage caused by runway debris, the dropping of the hand tools during servicing, etc., on the secondary aircraft structures fabricated with the composite materials. The results show the preload and the impact energy combinations necessary to cause catastrophic failure in the laminates tested. A set of faired curves indicating the failure thresholds is shown separately for the tension-and compression-loaded laminates. The specific-strengths and -modulii for the various laminates tested are also given.

  5. Heat transfer through the walls of a tube by forced convection with high and low velocity. Study using dimensional analysis

    International Nuclear Information System (INIS)

    Arenas, A.; Madrid, C.N.; Herranz, A.

    1989-01-01

    The heat transfer through the walls of a tube by forced convection was studied using Palacios' dimensional analysis. It was demostrated that different dimensional bases are required for study the high and low velocity fluxes. The results obtained were better than those of the classical dimensional analysis, and were confirmed bay experiment. (Author)

  6. DOWN'S ANOMALY.

    Science.gov (United States)

    PENROSE, L.S.; SMITH, G.F.

    BOTH CLINICAL AND PATHOLOGICAL ASPECTS AND MATHEMATICAL ELABORATIONS OF DOWN'S ANOMALY, KNOWN ALSO AS MONGOLISM, ARE PRESENTED IN THIS REFERENCE MANUAL FOR PROFESSIONAL PERSONNEL. INFORMATION PROVIDED CONCERNS (1) HISTORICAL STUDIES, (2) PHYSICAL SIGNS, (3) BONES AND MUSCLES, (4) MENTAL DEVELOPMENT, (5) DERMATOGLYPHS, (6) HEMATOLOGY, (7)…

  7. Deformation of Lawsonite at High Pressure and High Temperature - Implications for Low Velocity Layers in Subduction Zones

    Science.gov (United States)

    Amiguet, E.; Hilairet, N.; Wang, Y.; Gillet, P.

    2014-12-01

    During subduction, the hydrated oceanic crust undergoes a series of metamorphic reactions and transform gradually to blueschists and eclogite at depths of 20-50 km. Detailed seismic observations of subduction zones suggest a complex layered structure with the presence of a Low Velocity Layer (LVL) related to the oceanic crust [1] persisting to considerable depths (100- 250 km).While the transformation from blueschist to eclogite [2] and the presence of glaucophane up to 90-100 km [3] could explain some of these observations, the presence of LVL at greater depths could be related to the presence of the hydrous mineral lawsonite (CaAl2(Si2O7)(OH)2 H2O). Its stability field extends to 8.5 GPa and 1100K corresponding to depths up to 250 km in cold hydrous part of subducting slabs [4]. Because these regions undergo large and heterogeneous deformation, lawsonite plasticity and crystal preferred orientation (CPOs) may strongly influence the dynamic of subduction zones and the seismic properties. We present a deformation study at high presssure and high temperature on lawsonite. Six samples were deformed at 4-10 GPa and 600K to 1000K using a D-DIA apparatus [5] at 13-BMD at GSECARS beamline, APS, in axial compression up to 30% deformation with strain rates of 3.10-4s-1 to 6.10-6s-1. We measured in-situ lattice strains (a proxy for macroscopic stress), texture and strain using synchrotron radiations and calculated the macroscopic stress using lawsonite elastic properties [6]. Results from lattice strain analysis show a dependence of flow stress with temperature and strain rate. Texture analysis coupled with transmission electron microscopy showed that dislocation creep is the dominant deformation mechanism under our deformation conditions. [1] Abers, Earth and Planetary Science Letters, 176, 323-330, 2000 [2] Helffrich et al., Journal of Geophysical Research, 94, 753-763, 1989 [3] Bezacier et al., Tectonophysics, 494, 201-210, 2010 [4] Schmidt & Poli, Earth and Planetary

  8. Classification of Low Velocity Impactors Using Spiral Sensing of Acousto-Ultrasonic Waves

    Science.gov (United States)

    Agbasi, Chijioke Raphael

    The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from nonlinearity and variability in the AUS signals due to materials, geometry, boundary conditions, wave dispersion, environmental conditions, sensor and hardware calibration etc. It is found that the frequency and speed of the guided wave generated in the plate can be quantized based on the impactor's relationship with the plate (i.e. the wave speed and the impactor's mechanical properties are coupled). In this work, in order to characterize the impact location and mechanical properties of imapctors, nonlinear transient phenomenon is empirically studied to decouple the understanding using the dominant frequency band (DFB) and Lag Index (LI) of the acousto-ultrasonic signals. Next the understanding was correlated with the elastic modulus of the impactor to predict transmitted force histories. The proposed method presented in this thesis is especially applicable for SHM where sensors cannot be widely or randomly distributed. Thus a strategic organization and localization of the sensors is achieved by implementing the geometric configuration of Theodorous Spiral Sensor Cluster (TSSC). The performance of TSSC in characterizing the impactor types are compared with other conventional sensor clusters (e.g. square, circular, random etc.) and it is shown that the TSSC is advantageous over

  9. Low-velocity impact behavior of weft-knitted spacer fabrics reinforced composites based on energy absorption

    Science.gov (United States)

    Hasanalizadeh, F.; Dabiryan, H.; Sadighi, M.

    2017-10-01

    Spacer fabrics are prefered to other types of textile fabrics in energy absorption applications due to existence of pile yarns. The particular geometry of spacer fabrics induce to increase resisting out of plane forces such as impact along their thickness. In order to investigate the low-velocity impact behaviour of composites reinforced with spacer fabric, weft-knitted spacer fabrics with different types of pile orientation and pile length were produced using E-glass yarns. Using produced fabrics and epoxy resin, composites samples were provided by hand lay-up method. Low-velocity impact test was carried out on the prepared samples based on a drop-weight method using spherical steel projectile. The indentation at maximum force was extracted as - comparative criteria used to calculate absorbed energy.The results show that the energy absorption of composites increases by increasing the pile density and pile length.

  10. Analysis of crustal thickness and off-axis low-velocity zones at the Endeavour segment of the Juan de Fuca Ridge

    Science.gov (United States)

    Wells, A. E.; Hooft, E. E.; Toomey, D. R.; Wilcock, W. S.; Weekly, R. T.

    2010-12-01

    is interpreted to have developed when the northwestward migrating Juan de Fuca Ridge overrode the mantle melt anomaly associated with the Heckle seamount chain. We investigate the segment-scale history of melt supply and the presence of off-axis crustal low-velocity zones using data from a multi-scale Endeavour seismic tomography experiment (ETOMO) that took place in September 2009. Seismic data were collected using four-component ocean bottom seismometers at 64 sites and the 6600 in3 airgun array of the R/V Marcus G. Langseth. The study includes 5567 shots covering 90 km along-axis and 50 km across. We examine seismic travel times of Pg and PmP phases as well as amplitude and waveform changes. Preliminary analysis of amplitude and waveform changes indicates that there are several crustal-level low-velocity, high-attenuation regions associated with off-axis ridges and volcanic features. We will determine whether there is enhanced melt supply due to the interaction between the Heckle seamount melting anomaly and the center of the Endeavour segment. We will also test whether volcano-tectonic cycles generate regions of thicker and thinner crust.

  11. Response of explosive HMX to low-velocity impact: modeling by the crystal plasticity finite element method

    Science.gov (United States)

    Ilnitsky, Denis; Inogamov, Nail; Zhakhovsky, Vasily

    2017-12-01

    Crystal plasticity finite element method (CPFEM) is a powerful tool for modeling the various deformation problems, which takes into account the different plasticity mechanisms at microscale of grain sizes and contribution of anisotropic behavior of each grain to macroscopic deformation pattern. Using this method we simulated deformation and plasticity of high explosive HMX produced by relatively low velocity impact. It was found that such plastic deformations of grains cause local heating which is sufficient to induce chemical reactions.

  12. Case report: whiplash-associated disorder from a low-velocity bumper car collision: history, evaluation, and surgery.

    Science.gov (United States)

    Duffy, Michael F; Stuberg, Wayne; DeJong, Stacey; Gold, Kurt V; Nystrom, N Ake

    2004-09-01

    Case report of a patient with a whiplash-associated disorder following a bumper car collision. Imaging studies failed to provide an anatomic explanation for the debilitating symptoms. To report a chronic, debilitating pain syndrome after a low-velocity bumper car collision while using complex range-of-motion data for the diagnosis, prognosis, and surgical indication in whiplash-associated disorder. The controversy of whiplash-associated disorder mainly concerns pathophysiology and collision dynamics. Although many investigations attempt to define a universal lesion or determine a threshold of force that may cause permanent injury, no consensus has been reached. Eight years after a low-velocity collision, the patient underwent surgical excision of multiple painful trigger points in the posterior neck. Computerized motion analysis was used for pre- and postoperative evaluations. Surgical treatment resulted in an increase in total active range of motion by 20%, reduced intake of pain medication, doubled the number of work hours, and generally led to a dramatic improvement in quality of life. This case of whiplash-associated disorder after a low-velocity collision highlights the difficulty in defining threshold of injury in regard to velocity. It also illustrates the value of computerized motion analysis in confirming the diagnosis of whiplash-associated disorder and in the evaluation of prognosis and treatment.

  13. Low-velocity zone and topography as a source of site amplification effect on Tarzana hill, California

    Science.gov (United States)

    Graizer, V.

    2009-01-01

    Tarzana station is located in the foothills of the Santa Monica Mountains in California near the crest of a low (Seism Soc Am 1996;86(1A):66-72], topography of this hill amplifies and polarizes ground motion in the frequency range of 3-5 Hz. Hill acts as a magnifying polarizing glass: It polarizes ground motion in the direction perpendicular to the strike of the hill and also amplifies ground motions that had been also amplified by a low-velocity layer.

  14. Dyonic anomalies

    International Nuclear Information System (INIS)

    Henningson, Mans; Johansson, Erik P.G.

    2005-01-01

    We consider the problem of coupling a dyonic p-brane in d=2p+4 space-time dimensions to a prescribed (p+2)-form field strength. This is particularly subtle when p is odd. For the case p=1, we explicitly construct a coupling functional, which is a sum of two terms: one which is linear in the prescribed field strength, and one which describes the coupling of the brane to its self-field and takes the form of a Wess-Zumino term depending only on the embedding of the brane world-volume into space-time. We then show that this functional is well-defined only modulo a certain anomaly, related to the Euler class of the normal bundle of the brane world-volume

  15. Dynamical properties for the problem of a particle in an electric field of wave packet: Low velocity and relativistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Diego F.M., E-mail: diegofregolente@gmail.com [Institute for Multiscale Simulations, Friedrich-Alexander Universität, D-91052, Erlangen (Germany); Leonel, Edson D., E-mail: edleonel@rc.unesp.br [Departamento de Estatística, Matemática Aplicada e Computação, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Departamento de Física, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, 13506-900, Rio Claro, SP (Brazil)

    2012-11-01

    We study some dynamical properties for the problem of a charged particle in an electric field considering both the low velocity and relativistic cases. The dynamics for both approaches is described in terms of a two-dimensional and nonlinear mapping. The structure of the phase spaces is mixed and we introduce a hole in the chaotic sea to let the particles to escape. By changing the size of the hole we show that the survival probability decays exponentially for both cases. Additionally, we show for the relativistic dynamics, that the introduction of dissipation changes the mixed phase space and attractors appear. We study the parameter space by using the Lyapunov exponent and the average energy over the orbit and show that the system has a very rich structure with infinite family of self-similar shrimp shaped embedded in a chaotic region.

  16. Study on the Characteristics of Wavelet Decomposed Details of Low-Velocity Impact Induced AE Signals in Composite Laminates

    International Nuclear Information System (INIS)

    Bang, Hyung Joon; Kim, Chun Gon

    2009-01-01

    Because the attenuation of AE signal in composite materials is relatively higher than that of metallic materials, it is required to develop a damage assessment technique less affected by the attenuation property of composite materials in order to use AE sensing as a damage detection method. In the signal processing procedure, it is profitable to use the leading wave that arrives first because the leading wave is less influenced by the boundary conditions. Using wavelet transform, we investigated the frequency characteristics of impact induced AE signals focused on the leading wave in advance and chose the key factors to discriminate the damaged condition quantitatively. In this research, we established a damage assessment technique using the sharing percentage of the wavelet detail components of AE signal, and conducted a low-velocity impact test on composite laminates to confirm the feasibility of the proposed signal processing method.

  17. Simulation of Low Velocity Impact Induced Inter- and Intra-Laminar Damage of Composite Beams Based on XFEM

    Science.gov (United States)

    Sun, Wei; Guan, Zhidong; Li, Zengshan

    2017-12-01

    In this paper, the Inter-Fiber Fracture (IFF) criterion of Puck failure theory based on the eXtended Finite Element Method (XFEM) was implemented in ABAQUS code to predict the intra-laminar crack initiation of unidirectional (UD) composite laminate. The transverse crack path in the matrix can be simulated accurately by the presented method. After the crack initiation, the propagation of the crack is simulated by Cohesive Zoom Model (CZM), in which the displacement discontinuities and stress concentration caused by matrix crack is introduced into the finite element (FE) model. Combined with the usage of the enriched element interface, which can be used to simulate the inter-laminar delamination crack, the Low Velocity Impact (LVI) induced damage of UD composite laminate beam with a typical stacking of composite laminates [05/903]S is studied. A complete crack initiation and propagation process was simulated and the numerical results obtained by the XFEM are consistent with the experimental results.

  18. Remarks on global anomalies in RCFT orientifolds

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Matematicas y Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands) and Instituto de Matematicas y Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain) and IMAPP, Radboud Universiteit, Nijmegen (Netherlands)]. E-mail: t58@nikhef.nl

    2006-01-26

    We check the list of supersymmetric standard model orientifold spectra of Dijkstra, Huiszoon and Schellekens for the presence of global anomalies, using probe branes. Absence of global anomalies is found to impose strong constraints, but in nearly all cases they are automatically satisfied by the solutions to the tadpole cancellation conditions.

  19. Chiral anomalies and differential geometry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1983-10-01

    Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)

  20. Circle compactification and 't Hooft anomaly

    Science.gov (United States)

    Tanizaki, Yuya; Misumi, Tatsuhiro; Sakai, Norisuke

    2017-12-01

    Anomaly matching constrains low-energy physics of strongly-coupled field theories, but it is not useful at finite temperature due to contamination from high-energy states. The known exception is an 't Hooft anomaly involving one-form symmetries as in pure SU( N ) Yang-Mills theory at θ = π. Recent development about large- N volume independence, however, gives us a circumstantial evidence that 't Hooft anomalies can also remain under circle compactifications in some theories without one-form symmetries. We develop a systematic procedure for deriving an 't Hooft anomaly of the circle-compactified theory starting from the anomaly of the original uncompactified theory without one-form symmetries, where the twisted boundary condition for the compactified direction plays a pivotal role. As an application, we consider Z_N -twisted C{P}^{N-1} sigma model and massless Z_N -QCD, and compute their anomalies explicitly.

  1. Ignition of steel alloys by impact of low-velocity iron/inert particles in gaseous oxygen

    Science.gov (United States)

    Benz, Frank J.; Mcilroy, Kenneth; Williams, Ralph E.

    1988-01-01

    The ignition of carbon steel and 316 and 304 stainless steels caused by the impact of low-velocity particles (a standard mixture consisting of 2 g of iron and 3 g of inert materials) in gaseous oxygen was investigated using NASA/White Sands Test Facility for the ignition test, and a subsonic particle impact chamber to accelerate the particles that were injected into flowing oxygen upstream of the target specimen. It was found that the oxygen velocities required to ignite the three alloys were the same as that required to ignite the particle mixture. Ignition occurred at oxygen velocities greater than 45 m/sec at 20 to 24 MPa and was found to be independent of pressure between 2 and 30 MPa. Comparison of the present results and the past results from Wegener (1964) with the Compressed Gas Association (CGA) oxygen velocity limits for safe operations indicates that the CGA limits may be excessively conservative at high pressures and too liberal at low pressures.

  2. Pervasive seismic low-velocity zones within stagnant plates in the mantle transition zone: Thermal or compositional origin?

    Science.gov (United States)

    Tauzin, B.; Kim, S.; Kennett, B. L. N.

    2017-11-01

    We exploit conversions between P and S waves for large-scale, high-resolution imaging of the mantle transition zone beneath Northwest Pacific and the margin of Eastern Asia. We find pervasive reflectivity concentrated in two bands with apparent wave-speed reduction of -2% to -4% about 50 km thick at the top of the transition zone and 100 km thick at the bottom. This negative reflectivity associated with the scattered-waves at depth is interpreted jointly with larger-scale mantle tomographic images, and is shown to delineate the stagnant portions of the subducted Pacific plate in the transition zone, with largely positive shear-wave velocity contrasts. The upper reflectivity zone connects to broad low-velocity regions below major intra-plate volcanoes, whereas the lower zone coincides locally with the occurrence of deep-focus earthquakes along the East Asia margin. Similar reflectivity is found in Pacific Northwest of the USA. We demonstrate that the thermal signature of plates alone is not sufficient to explain such features. Alternative explanations for these reflective zones include kinetic effects on olivine phase transitions (meta-stability), compositional heterogeneities within and above stagnant plates, complex wave-propagation effects in the heterogeneous slab structure, or a combination of such factors. We speculate that part of the negative reflectivity is the signature of compositional heterogeneities, as revealed by numerous other studies of seismic scattering throughout the mantle, and that such features could be widespread across the globe.

  3. A novel facility for reduced-gravity testing: A setup for studying low-velocity collisions into granular surfaces

    Science.gov (United States)

    Sunday, C.; Murdoch, N.; Cherrier, O.; Morales Serrano, S.; Valeria Nardi, C.; Janin, T.; Avila Martinez, I.; Gourinat, Y.; Mimoun, D.

    2016-08-01

    This work presents an experimental design for studying low-velocity collisions into granular surfaces in low-gravity. In the experiment apparatus, reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use of an Atwood machine, or a system of pulleys and counterweights. The starting height of the surface container and the initial separation distance between the projectile and surface are variable and chosen to accommodate collision velocities up to 20 cm/s and effective accelerations of ˜0.1 to 1.0 m/s2. Accelerometers, placed on the surface container and inside the projectile, provide acceleration data, while high-speed cameras capture the collision and act as secondary data sources. The experiment is built into an existing 5.5 m drop tower frame and requires the custom design of all components, including the projectile, surface sample container, release mechanism, and deceleration system. Data from calibration tests verify the efficiency of the experiment's deceleration system and provide a quantitative understanding of the performance of the Atwood system.

  4. A novel facility for reduced-gravity testing: A setup for studying low-velocity collisions into granular surfaces.

    Science.gov (United States)

    Sunday, C; Murdoch, N; Cherrier, O; Morales Serrano, S; Valeria Nardi, C; Janin, T; Avila Martinez, I; Gourinat, Y; Mimoun, D

    2016-08-01

    This work presents an experimental design for studying low-velocity collisions into granular surfaces in low-gravity. In the experiment apparatus, reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use of an Atwood machine, or a system of pulleys and counterweights. The starting height of the surface container and the initial separation distance between the projectile and surface are variable and chosen to accommodate collision velocities up to 20 cm/s and effective accelerations of ∼0.1 to 1.0 m/s(2). Accelerometers, placed on the surface container and inside the projectile, provide acceleration data, while high-speed cameras capture the collision and act as secondary data sources. The experiment is built into an existing 5.5 m drop tower frame and requires the custom design of all components, including the projectile, surface sample container, release mechanism, and deceleration system. Data from calibration tests verify the efficiency of the experiment's deceleration system and provide a quantitative understanding of the performance of the Atwood system.

  5. Development of CHF correlation “MG-NV” for low pressure and low velocity conditions applied to PWR safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yumura, T.; Yodo, T.; Makino, Y.; Suemura, T. [Mitsubishi Heavy Industries, LTD., Kobe, Hyogo (Japan)

    2011-07-01

    The Critical Heat Flux (CHF) is one of the important parameters in the safety analysis of Pressurized Water Reactor (PWR). If the CHF is reached, an abrupt drop occurs in the heat transfer between the fuel rod cladding and the reactor coolant, which may induce a large temperature excursion of fuel cladding and a subsequent fuel failure. Therefore, accurate prediction of CHF is required in order to assure a sufficient safety margin in the PWR core. Mitsubishi Heavy Industries, ltd (MHI) is developing a new series of CHF correlations which covers various fuel designs and wide range of fluid conditions with sufficient reliability. In this paper, a new CHF correlation, MG-NV (Mitsubishi Generalized correlation for Non-Vane grid spacers) is presented. This correlation is one of the basic components of the new correlation series and was developed to cover low pressure and low velocity conditions where the rod bundle CHF data are limited. The CHF correlation was developed based on open CHF database and provides conservative but more reliable rod bundle CHF predictions compared with the conventional CHF correlations used in safety analyses at low pressure condition, such as Main Steam Line Break event. (author)

  6. Learning about Poland Anomaly

    Science.gov (United States)

    ... these symptoms occur on one side of the body (unilateral). Also, it is important to note that Poland anomaly does not typically affect intelligence. Top of page What causes Poland anomaly? The ...

  7. Vascular Anomalies in Pediatrics.

    Science.gov (United States)

    Foley, Lisa S; Kulungowski, Ann M

    2015-08-01

    A standardized classification system allows improvements in diagnostic accuracy. Multidisciplinary vascular anomaly centers combine medical, surgical, radiologic, and pathologic expertise. This collaborative approach tailors treatment and management of vascular anomalies for affected individuals.

  8. Magnetic hyperfine anomalies

    International Nuclear Information System (INIS)

    Buettgenbach, S.

    1984-01-01

    This study is concerned with the measurement and interpretation of magnetic hyperfine anomalies in electronic and muonic atoms, i.e. effects of the distribution of nuclear magnetization on the magnetic dipole hyperfine interaction. After a summary of the relevant theory and a review of experimental techniques, hyperfine anomaly results are discussed in terms of various nuclear models. The use of the anomaly for yielding information about the origin of magnetic hyperfine interactions is outlined. Experimental and theoretical hyperfine anomalies are tabulated. (Auth.)

  9. Tracheobronchial Branching Anomalies

    International Nuclear Information System (INIS)

    Hong, Min Ji; Kim, Young Tong; Jou, Sung Shick; Park, A Young

    2010-01-01

    There are various congenital anomalies with respect to the number, length, diameter, and location of tracheobronchial branching patterns. The tracheobronchial anomalies are classified into two groups. The first one, anomalies of division, includes tracheal bronchus, cardiac bronchus, tracheal diverticulum, pulmonary isomerism, and minor variations. The second one, dysmorphic lung, includes lung agenesis-hypoplasia complex and lobar agenesis-aplasia complex

  10. Tracheobronchial Branching Anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Min Ji; Kim, Young Tong; Jou, Sung Shick [Soonchunhyang University, Cheonan Hospital, Cheonan (Korea, Republic of); Park, A Young [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)

    2010-04-15

    There are various congenital anomalies with respect to the number, length, diameter, and location of tracheobronchial branching patterns. The tracheobronchial anomalies are classified into two groups. The first one, anomalies of division, includes tracheal bronchus, cardiac bronchus, tracheal diverticulum, pulmonary isomerism, and minor variations. The second one, dysmorphic lung, includes lung agenesis-hypoplasia complex and lobar agenesis-aplasia complex

  11. Anomalies of nuclear criticality

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, E.D.

    1979-06-01

    During the development of nuclear energy, a number of apparent anomalies have become evident in nuclear criticality. Some of these have appeared in the open literature and some have not. Yet, a naive extrapolation or application of existing data, without knowledge of the anomalies, could lead to potentially serious consequences. This report discusses several of these anomalies.

  12. Low Velocity Seismic Waves Produced by Stick-Slip Processes During the Drainage of Two Supraglacial Lakes in Greenland

    Science.gov (United States)

    Kenyon, P. M.; Orantes, E. J.; Grynewize, S.; Tedesco, M.

    2016-12-01

    The drainage of supraglacial lakes over the Greenland ice sheet has been shown to have a significant impact on ice dynamics and subglacial hydrology. As supraglacial lakes drain, they produce seismic waves that can be detected on both local and regional scales. Studying such waves and the originating phenomena has the potential to advance our understanding of the subglacial processes involved. Here we present the results of an analysis of high frequency seismic waves generated during the drainage of two supraglacial lakes in southwestern Greenland. The two lakes drained by contrasting mechanisms. One (Lake Half Moon) drained slowly by overflow into an existing moulin. Here GPS data, recorded during the drainage, show an increase in ice sheet velocity that begins well before the time of maximum lake depth. The other lake (Lake Ponting) drained suddenly by hydrofracture through the lake bed. In this case, the GPS data show an increase in velocity that is essentially simultaneous with the maximum lake depth. In both cases, vertical component seismograms were obtained from the Greenland Ice Sheet Monitoring Network (GLISN) for several hours before and after the lake drainage. Arrival times were picked manually, using the criterion that an arrival must have a minimum amplitude of twice the noise level. The arrivals were then plotted on graphs of time versus distance from the lake in question. Several linear trends are visible on each graph. The velocities calculated from the slopes of these trends are unexpectedly low. We suggest that one explanation for this might be that the waves are traveling in a layer of till at the base of the ice sheet, that forms a low velocity channel. When compared with GPS and lake depth data, the origin times of the waves coincide with the velocity increase in both cases. Therefore, we conclude that the waves are being generated by stick-slip processes involving the slippage of the ice sheet on an underlying layer of till.

  13. The focusing effect of P-wave in the Moon's and Earth's low-velocity core. Analytical solution

    Science.gov (United States)

    Fatyanov, A. G.; Burmin, V. Yu

    2018-04-01

    The important aspect in the study of the structure of the interiors of planets is the question of the presence and state of core inside them. While for the Earth this task was solved long ago, the question of whether the core of the Moon is in a liquid or solid state up to the present is debatable up to present. If the core of the Moon is liquid, then the velocity of longitudinal waves in it should be lower than in the surrounding mantle. If the core is solid, then most likely, the velocity of longitudinal waves in it is higher than in the mantle. Numerical calculations of the wave field allow us to identify the criteria for drawing conclusions about the state of the lunar core. In this paper we consider the problem of constructing an analytical solution for wave fields in a layered sphere of arbitrary radius. A stable analytic solution is obtained for the wave fields of longitudinal waves in a three-layer sphere. Calculations of the total wave fields and rays for simplified models of the Earth and the Moon with real parameters are presented. The analytical solution and the ray pattern showed that the low-velocity cores of the Earth and the Moon possess the properties of a collecting lens. This leads to the emergence of a wave field focusing area. As a result, focused waves of considerable amplitude appear on the surface of the Earth and the Moon. In the Earth case, they appear before the first PKP-wave arrival. These are so-called "precursors", which continue in the subsequent arrivals of waves. At the same time, for the simplified model of the Earth, the maximum amplitude growth is observed in the 147-degree region. For the Moon model, the maximum amplitude growth is around 180°.

  14. Comparing damage from low-velocity impact and quasi-static indentation in automotive carbon/epoxy and glass/polyamide-6 laminates

    NARCIS (Netherlands)

    Spronk, S.W.F.; Kersemans, M.; Gilabert, F. A.; Sevenois, R.D.B.; Garoz, D.; Kassapoglou, C.; Van Paepegem, W.

    2018-01-01

    The results of a low-velocity impact programme on both carbon/epoxy and glass/polyamide-6 composite laminates are compared to the results of quasi-static indentation. Cross-ply and quasi-isotropic stacking sequences are impacted and quasi-static indentation tests are performed up to the same

  15. Crack wave propagation along fracture with an induced low-velocity layer; Teisokudo no chika kiretsu zone wo denpasuru kiretsuha no bunsan tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Nagano, K. [Muroran Institute of Technology, Hokkaido (Japan)

    1997-10-22

    A study has been performed on underground cracks working as a geothermy reservoir layer, with respect to characteristics of elastic waves propagating with their energy concentrated on a boundary between rocks around the cracks and fluid in the underground cracks, or `crack waves`. The study has modeled a multi-crack reservoir layer according to the three-layer structure of the fluid layer and low-velocity solid layers around the former layer, whereas crack waves propagating therein were discussed for their dispersion characteristics. As a result of discussions, a guideline to the crack wave measurement at actual fields was put together as follows: because the low-velocity layer affects the dispersion characteristics of the crack waves, the structure and characteristics of the multi-crack reservoir layer may possibly be evaluated by measuring the velocity of the crack waves; evaluating the low-velocity layers requires proper selection of frequency of the crack wave to be measured; for example, at the Higashi Hachimantai field, a crack wave of several hundred hertz must be analyzed; and thickness of the low-velocity layers around main cracks, which can be estimated from the velocity of the crack wave is two meters at the greatest. 6 refs., 3 figs., 2 tabs.

  16. An impactor origin for lunar magnetic anomalies.

    Science.gov (United States)

    Wieczorek, Mark A; Weiss, Benjamin P; Stewart, Sarah T

    2012-03-09

    The Moon possesses strong magnetic anomalies that are enigmatic given the weak magnetism of lunar rocks. We show that the most prominent grouping of anomalies can be explained by highly magnetic extralunar materials from the projectile that formed the largest and oldest impact crater on the Moon: the South Pole-Aitken basin. The distribution of projectile materials from a model oblique impact coincides with the distribution of magnetic anomalies surrounding this basin, and the magnetic properties of these materials can account for the intensity of the observed anomalies if they were magnetized in a core dynamo field. Distal ejecta from this event can explain the origin of isolated magnetic anomalies far from this basin.

  17. Congenital optic nerve anomalies.

    Science.gov (United States)

    Martín-Begué, N; Saint-Gerons, M

    2016-12-01

    To update the current knowledge about congenital optic disc anomalies. A comprehensive literature search was performed in the major biomedical databases. Patients with these anomalies usually have poor vision in infancy. Refractive errors are common, and serous retinal detachment may develop in some of these anomalies. It is critically important to clinically differentiate between these congenital optic disc anomalies, as central nervous system malformations are common in some, whereas others may be associated with systemic anomalies. Congenital optic disc anomalies are a heterogeneous group of pathologies with characteristic fundus appearance and systemic associations. We should always try to make a correct diagnosis, in order to ask for specific tests, as well as to provide an adequate follow-up. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Anomaly-free models for flavour anomalies

    Science.gov (United States)

    Ellis, John; Fairbairn, Malcolm; Tunney, Patrick

    2018-03-01

    We explore the constraints imposed by the cancellation of triangle anomalies on models in which the flavour anomalies reported by LHCb and other experiments are due to an extra U(1)^' gauge boson Z^' . We assume universal and rational U(1)^' charges for the first two generations of left-handed quarks and of right-handed up-type quarks but allow different charges for their third-generation counterparts. If the right-handed charges vanish, cancellation of the triangle anomalies requires all the quark U(1)^' charges to vanish, if there are either no exotic fermions or there is only one Standard Model singlet dark matter (DM) fermion. There are non-trivial anomaly-free models with more than one such `dark' fermion, or with a single DM fermion if right-handed up-type quarks have non-zero U(1)^' charges. In some of the latter models the U(1)^' couplings of the first- and second-generation quarks all vanish, weakening the LHC Z^' constraint, and in some other models the DM particle has purely axial couplings, weakening the direct DM scattering constraint. We also consider models in which anomalies are cancelled via extra vector-like leptons, showing how the prospective LHC Z^' constraint may be weakened because the Z^' → μ ^+ μ ^- branching ratio is suppressed relative to other decay modes.

  19. Corrigendum to "Extracting Low-Velocity Concentric and Eccentric Dynamic Muscle Properties from Isometric Contraction Experiments" Mathematical Biosciences 278 (2016) 77-93.

    Science.gov (United States)

    Rockenfeller, R; Günther, M

    2017-09-01

    We provide corrections to our paper "Extracting Low-Velocity Concentric and Eccentric Dynamic Muscle Properties from Isometric Contraction Experiments, Mathematical Biosciences 278 (2016), p. 77-93", where we used an erroneous form of Hatze's activation dynamics. The statements of the paper still hold true in general, even though the numerical values of Tables 1, 2, and 3 slightly vary. The authors would like to apologize for any inconvenience caused. Copyright © 2017. Published by Elsevier Inc.

  20. Dental Anomalies: An Update

    Directory of Open Access Journals (Sweden)

    Fatemeh Jahanimoghadam

    2016-01-01

    Full Text Available Dental anomalies are usual congenital malformation that can happen either as isolated findings or as a part of a syndrome. Developmental anomalies influencing the morphology exists in both deciduous and permanent dentition and shows different forms such as gemination, fusion, concrescence, dilaceration, dens evaginatus (DE, enamel pearls, taurodontism or peg-shaped laterals. All These anomalies have clinical significance concerning aesthetics, malocclusion and more necessary preparing of the development of dental decays and oral diseases. Through a search in PubMed, Google, Scopus and Medline, a total of eighty original research papers during 1928-2016 were found with the keywords such as dental anomaly, syndrome, tooth and hypodontia. One hundred review titles were identified, eighty reviews were retrieved that were finally included as being relevant and of sufficient quality. In this review, dental anomalies including gemination, fusion, concrescence, dilaceration, dens invaginatus, DE, taurodontism, enamel pearls, fluorosis, peg-shaped laterals, dentinal dysplasia, regional odontodysplasia and hypodontia are discussed. Diagnosing dental abnormality needs a thorough evaluation of the patient, involving a medical, dental, familial and clinical history. Clinical examination and radiographic evaluation and in some of the cases, specific laboratory tests are also needed. Developmental dental anomalies require careful examination and treatment planning. Where one anomaly is present, clinicians should suspect that other anomalies may also be present. Moreover, careful clinical and radiographical examination is required. Furthermore, more complex cases need multidisciplinary planning and treatment.

  1. Anomalies on orbifolds

    Energy Technology Data Exchange (ETDEWEB)

    Arkani-Hamed, Nima; Cohen, Andrew G.; Georgi, Howard

    2001-03-16

    We discuss the form of the chiral anomaly on an S1/Z2 orbifold with chiral boundary conditions. We find that the 4-divergence of the higher-dimensional current evaluated at a given point in the extra dimension is proportional to the probability of finding the chiral zero mode there. Nevertheless the anomaly, appropriately defined as the five dimensional divergence of the current, lives entirely on the orbifold fixed planes and is independent of the shape of the zero mode. Therefore long distance four dimensional anomaly cancellation ensures the consistency of the higher dimensional orbifold theory.

  2. Theoretically Optimal Distributed Anomaly Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel general framework for distributed anomaly detection with theoretical performance guarantees is proposed. Our algorithmic approach combines existing anomaly...

  3. Magnetotransport phenomena related to the chiral anomaly in Weyl semimetals

    Science.gov (United States)

    Spivak, B. Z.; Andreev, A. V.

    2016-02-01

    We present a theory of magnetotransport phenomena related to the chiral anomaly in Weyl semimetals. We show that conductivity, thermal conductivity, thermoelectric, and the sound absorption coefficients exhibit strong and anisotropic magnetic field dependencies. We also discuss properties of magnetoplasmons and magnetopolaritons, whose existences are entirely determined by the chiral anomaly. Finally, we discuss the conditions of applicability of the quasiclassical description of electron transport phenomena related to the chiral anomaly.

  4. Anomaly Detection in Sequences

    Data.gov (United States)

    National Aeronautics and Space Administration — We present a set of novel algorithms which we call sequenceMiner, that detect and characterize anomalies in large sets of high-dimensional symbol sequences that...

  5. Skyrmions and anomalies

    International Nuclear Information System (INIS)

    Rho, M.

    1987-02-01

    The author summarizes the works presented at the meeting on skyrmions and anomalies. He divides the principal issues of this workshop into five categories: QCD effective lagrangians, chiral bags and the Cheshire cat principle, strangeness problem, phenomenology, mathematical structure

  6. Congenital laryngeal anomalies,

    OpenAIRE

    Rutter, Michael J.

    2014-01-01

    Introduction: It is essential for clinicians to understand issues relevant to the airway management of infants and to be cognizant of the fact that infants with congenital laryngeal anomalies are at particular risk for an unstable airway. Objectives: To familiarize clinicians with issues relevant to the airway management of infants and to present a succinct description of the diagnosis and management of an array of congenital laryngeal anomalies. Methods: Revision article, in which the ma...

  7. Fivebrane gravitational anomalies

    International Nuclear Information System (INIS)

    Becker, Katrin; Becker, Melanie

    2000-01-01

    Freed, Harvey, Minasian and Moore (FHMM) have proposed a mechanism to cancel the gravitational anomaly of the M-theory fivebrane coming from diffeomorphisms acting on the normal bundle. This procedure is based on a modification of the conventional M-theory Chern-Simons term. We apply the FHMM mechanism in the ten-dimensional type IIA theory. We then analyze the relation to the anomaly cancellation mechanism for the type IIA fivebrane proposed by Witten

  8. Origin of conductivity anomalies in the asthenosphere

    Science.gov (United States)

    Yoshino, T.; Zhang, B.

    2013-12-01

    Electrical conductivity anomalies with anisotropy parallel to the plate motion have been observed beneath the oceanic lithosphere by electromagnetic studies (e.g., Evans et al., 2005; Baba et al., 2010; Naif et al., 2013). Electrical conductivity of the oceanic asthenosphere at ~100 km depth is very high, about 10-2 to 10-1 S/m. This zone is also known in seismology as the low velocity zone. Since Karato (1990) first suggested that electrical conductivity is sensitive to water content in NAMs, softening of asthenosphere has been regarded as a good indicator for constraining the distribution of water. There are two difficulties to explain the observed conductivity features in the asthenosphere. Recent publications on electrical conductivity of hydrous olivine suggested that olivine with the maximum soluble H2O content at the top of the asthenosphere has much lower conductivity less than 0.1 S/m (e.g., Yoshino et al., 2006; 2009a; Poe et al., 2010; Du Frane and Tyburczy, 2012; Yang, 2012), which is a typical value of conductivity anomaly observed in the oceanic mantle. Partial melting has been considered as an attractive agent for substantially raising the conductivity in this region (Shankland and Waff, 1977), because basaltic melt has greater electrical conductivity (> 100.5 S/m) and high wetting properties. However, dry mantle peridotite cannot reach the solidus temperature at depth 100 km. Volatile components can dramatically reduce melting temperature, even if its amount is very small. Recent studies on conductivity measurement of volatile-bearing melt suggest that conductivity of melt dramatically increases with increasing volatile components (H2O: Ni et al., 2010a, b; CO2: Gaillard et al., 2008; Yoshino et al., 2010; 2012a). Because incipient melt includes higher amount of volatile components, conductivity enhancement by the partial melt is very effective at temperatures just above that of the volatile-bearing peridotite solidus. In this study, the electrical

  9. The Holographic Weyl anomaly

    CERN Document Server

    Henningson, M; Henningson, Mans; Skenderis, Kostas

    1998-01-01

    We calculate the Weyl anomaly for conformal field theories that can be described via the adS/CFT correspondence. This entails regularizing the gravitational part of the corresponding supergravity action in a manner consistent with general covariance. Up to a constant, the anomaly only depends on the dimension d of the manifold on which the conformal field theory is defined. We present concrete expressions for the anomaly in the physically relevant cases d = 2, 4 and 6. In d = 2 we find for the central charge c = 3 l/ 2 G_N in agreement with considerations based on the asymptotic symmetry algebra of adS_3. In d = 4 the anomaly agrees precisely with that of the corresponding N = 4 superconformal SU(N) gauge theory. The result in d = 6 provides new information for the (0, 2) theory, since its Weyl anomaly has not been computed previously. The anomaly in this case grows as N^3, where N is the number of coincident M5 branes, and it vanishes for a Ricci-flat background.

  10. QCD anomalies in hadronic weak decays

    International Nuclear Information System (INIS)

    Gerard, J.-M.; Trine, S.

    2004-01-01

    We consider the flavor-changing operators associated with the strong axial and trace anomalies. Their short-distance generation through penguinlike diagrams is obtained within the QCD external field formalism. Standard-model operator evolution exhibits a suppression of anomalous effects in K and B hadronic weak decays. A genuine set of dimension-eight ΔS=1 operators is also displayed

  11. Notepad-like triboelectric generator for efficiently harvesting low-velocity motion energy by interconversion between kinetic energy and elastic potential energy.

    Science.gov (United States)

    Liu, Guanlin; Leng, Qiang; Lian, Jiawei; Guo, Hengyu; Yi, Xi; Hu, Chenguo

    2015-01-21

    Great attention has been paid to nanogenerators that harvest energy from ambient environments lately. In order to give considerable output current, most nanogenerators require high-velocity motion that in most cases can hardly be provided in our daily life. Here we report a notepad-like triboelectric generator (NTEG), which uses simple notepad-like structure to generate elastic deformation so as to turn a low-velocity kinetic energy into high-velocity kinetic energy through the conversion of elastic potential energy. Therefore, the NTEG can achieve high current output under low-velocity motion, which completely distinguishes it from tribogenerators previously reported. The factors that may affect the output performance are explored, including the number of slices, active length of slice, press speed, and vertical displacement. In addition, the working mechanism is systematically studied, indicating that the efficiency of the generator can be greatly enhanced by interconversion between kinetic energy and elastic potential energy. The short-circuit current, the open-circuit voltage, and power density are 205 μA and 470 V and 9.86 W/m(2), respectively, which is powerful enough to light up hundreds of light-emitting diodes (LEDs) and charge a commercial capacitor. Besides, NTEGs have been successfully applied to a self-powered door monitor.

  12. Analytical and Mathematical Modeling and Optimization of Fiber Metal Laminates (FMLs subjected to low-velocity impact via combined response surface regression and zero-One programming

    Directory of Open Access Journals (Sweden)

    Faramarz Ashenai Ghasemi

    Full Text Available This paper presents analytical and mathematical modeling and optimization of the dynamic behavior of the fiber metal laminates (FMLs subjected to low-velocity impact. The deflection to thickness (w/h ratio has been identified through the governing equations of the plate that are solved using the first-order shear deformation theory as well as the Fourier series method. With the help of a two degrees-of-freedom system, consisting of springs-masses, and the Choi's linearized Hertzian contact model the interaction between the impactor and the plate is modeled. Thirty-one experiments are conducted on samples of different layer sequences and volume fractions of Al plies in the composite Structures. A reliable fitness function in the form of a strict linear mathematical function constructed. Using an ordinary least square method, response regression coefficients estimated and a zero-one programming technique proposed to optimize the FML plate behavior subjected to any technological or cost restrictions. The results indicated that FML plate behavior is highly affected by layer sequences and volume fractions of Al plies. The results also showed that, embedding Al plies at outer layers of the structure significantly results in a better response of the structure under low-velocity impact, instead of embedding them in the middle or middle and outer layers of the structure.

  13. Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

    Science.gov (United States)

    Zhao, Xia; Yang, Guang

    2017-01-01

    The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

  14. Strong tracking adaptive Kalman filters for underwater vehicle dead reckoning

    Science.gov (United States)

    Xiao, Kun; Fang, Shao-Ji; Pang, Yong-Jie

    2007-06-01

    To impove underwater vehicle dead reckoning, a developed strong tracking adaptive kalman filter is proposed. The filter is improved with an additional adaptive factor and an estimator of measurement noise covariance. Since the magnitude of fading factor is changed adaptively, the tracking ability of the filter is still enhanced in low velocity condition of underwater vehicles. The results of simulation tests prove the presented filter effective.

  15. Low Risk Anomalies?

    DEFF Research Database (Denmark)

    Schneider, Paul; Wagner, Christian; Zechner, Josef

    This paper shows that stocks' CAPM alphas are negatively related to CAPM betas if investors demand compensation for negative skewness. Thus, high (low) beta stocks appear to underperform (outperform). This apparent anomaly merely reflects compensation for residual coskewness ignored by the CAPM...

  16. Venus - Ishtar gravity anomaly

    Science.gov (United States)

    Sjogren, W. L.; Bills, B. G.; Mottinger, N. A.

    1984-01-01

    The gravity anomaly associated with Ishtar Terra on Venus is characterized, comparing line-of-sight acceleration profiles derived by differentiating Pioneer Venus Orbiter Doppler residual profiles with an Airy-compensated topographic model. The results are presented in graphs and maps, confirming the preliminary findings of Phillips et al. (1979). The isostatic compensation depth is found to be 150 + or - 30 km.

  17. Bolivian Bouguer Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Bouguer anomaly grid for the country of Bolivia.Number of columns is 550 and number of rows is 900. The order of the data is from the lower left to the...

  18. Anomaly Busters II

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The anomaly busters had struck on the first day of the Kyoto meeting with Yoji Totsuka of Tokyo speaking on baryon number nonjjonservation and 'related topics'. The unstable proton is a vital test of grand unified pictures pulling together the electroweak and quark/gluon forces in a single field theory

  19. The reactor antineutrino anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Haser, Julia; Buck, Christian; Lindner, Manfred [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    2016-07-01

    Major discoveries were made in the past few years in the field of neutrino flavour oscillation. Nuclear reactors produce a clean and intense flux of electron antineutrinos and are thus an essential neutrino source for the determination of oscillation parameters. Most currently the reactor antineutrino experiments Double Chooz, Daya Bay and RENO have accomplished to measure θ{sub 13}, the smallest of the three-flavour mixing angles. In the course of these experiments two anomalies emerged: (1) the reanalysis of the reactor predictions revealed a deficit in experimentally observed antineutrino flux, known as the ''reactor antineutrino anomaly''. (2) The high precision of the latest generation of neutrino experiments resolved a spectral shape distortion relative to the expected energy spectra. Both puzzles are yet to be solved and triggered new experimental as well as theoretical studies, with the search for light sterile neutrinos as most popular explanation for the flux anomaly. This talk outlines the two reactor antineutrino anomalies. Discussing possible explanations for their occurrence, recent and upcoming efforts to solve the reactor puzzles are highlighted.

  20. Echocardiography in Ebstein's anomaly

    NARCIS (Netherlands)

    W.J. Gussenhoven (Wilhelmina Johanna)

    1984-01-01

    textabstractIn this thesis the value of echocardiography is evaluated for the diagnosis of Ebstein's anomaly of the tricuspid valve. This congenital heart defect, first described in 1866 by Wilhelm Ebstein, is characterized by an apical displacement of the septal and inferior tricuspid valve

  1. Dealing with Ebstein's anomaly

    NARCIS (Netherlands)

    Geerdink, L.M.; Kapusta, L.

    2014-01-01

    Ebstein's anomaly is a complex congenital disorder of the tricuspid valve. Presentation in neonatal life and (early) childhood is common. Disease severity and clinical features vary widely and require a patient-tailored treatment. In this review, we describe the natural history of children and

  2. Assessing Asset Pricing Anomalies

    NARCIS (Netherlands)

    W.A. de Groot (Wilma)

    2017-01-01

    markdownabstractOne of the most important challenges in the field of asset pricing is to understand anomalies: empirical patterns in asset returns that cannot be explained by standard asset pricing models. Currently, there is no consensus in the academic literature on the underlying causes of

  3. Algebra of anomalies

    International Nuclear Information System (INIS)

    Talon, M.

    1987-01-01

    The algebraic set up for anomalies, a la Stora, is reviewed. Then a brief account is provided of the work of M. Dubois Violette, M. Talon, C. Viallet, in which the general algebraic solution to the consistency conditions is described. 34 references

  4. Low-velocity impact-induced delamination detection by use of the S{sub 0} guided wave mode in cross-ply composite plates: a numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Khazar; Ha, Sung Kyu [Hanyang University, Ansan (Korea, Republic of)

    2014-02-15

    Finite element method based numerical simulations are performed to identify low-velocity impact-induced asymmetrically-located delamination in the [0/90{sub 3}]{sub S} and [0/90]{sub 2S} composite plates, respectively, using a fundamental symmetric guided wave mode (S{sub 0}). The wave attenuation effect due to the viscoelasticity of the composite material is modeled by calculating the Lamb wave attenuation constants and using the Rayleigh proportional damping model. The estimated sizes and locations of the delamination in both plates were in good agreement with the experimental measurements. Moreover, the analysis of wave structure of the impacted plates shows that when the S{sub 0} mode propagates through the damaged region, the delamination mouth opens up due to the presence of standing waves, which are generated as a consequence of multiple reflections of trapped waves with the delamination boundaries.

  5. Low velocity floor level displacement ventilation systems: Technology assessment. Sistemi di distribuzione dell'aria a pavimento a bassa velocita': Vecchie e nuove conoscenze

    Energy Technology Data Exchange (ETDEWEB)

    Borjesson, J.A.; Bertomeu, L.; Marchetti, F.

    1992-12-01

    Although the concept of floor level air displacement ventilation is not in fact truly innovative given that it has already been tried during the 1980's, this paper shows that the combination of the advantageous natural cooling air circulation dynamics inherent in this method, combined with modern air diffusion equipment, offers interesting opportunities for energy conservation. The thermodynamics/air flow analysis indicates that from 20 to 40% energy savings can be obtained, in addition to reduced ventilation system operating times, with the effective application of low velocity floor level displacement air distribution systems as compared with conventional ventilation systems using the air mixing concept. It is shown how this innovative air cooling/recirculation technique is particularly suitable for conditions characterized by high air infiltration, high heating load and low indoor air pollution.

  6. The Pioneer Anomaly

    Directory of Open Access Journals (Sweden)

    Viktor T. Toth

    2010-09-01

    Full Text Available Radio-metric Doppler tracking data received from the Pioneer 10 and 11 spacecraft from heliocentric distances of 20-70 AU has consistently indicated the presence of a small, anomalous, blue-shifted frequency drift uniformly changing with a rate of ~6 × 10–9 Hz/s. Ultimately, the drift was interpreted as a constant sunward deceleration of each particular spacecraft at the level of aP = (8.74 ± 1.33 × 10–10 m/s2. This apparent violation of the Newton's gravitational inverse square law has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. In this review, we summarize the current knowledge of the physical properties of the anomaly and the conditions that led to its detection and characterization. We review various mechanisms proposed to explain the anomaly and discuss the current state of efforts to determine its nature. A comprehensive new investigation of the anomalous behavior of the two Pioneers has begun recently. The new efforts rely on the much-extended set of radio-metric Doppler data for both spacecraft in conjunction with the newly available complete record of their telemetry files and a large archive of original project documentation. As the new study is yet to report its findings, this review provides the necessary background for the new results to appear in the near future. In particular, we provide a significant amount of information on the design, operations and behavior of the two Pioneers during their entire missions, including descriptions of various data formats and techniques used for their navigation and radio-science data analysis. As most of this information was recovered relatively recently, it was not used in the previous studies of the Pioneer anomaly, but it is critical for the new investigation.

  7. Ferret Workflow Anomaly Detection System

    National Research Council Canada - National Science Library

    Smith, Timothy J; Bryant, Stephany

    2005-01-01

    The Ferret workflow anomaly detection system project 2003-2004 has provided validation and anomaly detection in accredited workflows in secure knowledge management systems through the use of continuous, automated audits...

  8. Genetics Home Reference: Peters anomaly

    Science.gov (United States)

    ... navigation Home Page Search Home Health Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Share: Email Facebook Twitter Home Health Conditions Peters anomaly Peters anomaly Printable PDF Open All Close All ...

  9. Penile Anomalies in Adolescence

    Directory of Open Access Journals (Sweden)

    Dan Wood

    2011-01-01

    Full Text Available This article considers the impact and outcomes of both treatment and underlying condition of penile anomalies in adolescent males. Major congenital anomalies (such as exstrophy/epispadias are discussed, including the psychological outcomes, common problems (such as corporal asymmetry, chordee, and scarring in this group, and surgical assessment for potential surgical candidates. The emergence of new surgical techniques continues to improve outcomes and potentially raises patient expectations. The importance of balanced discussion in conditions such as micropenis, including multidisciplinary support for patients, is important in order to achieve appropriate treatment decisions. Topical treatments may be of value, but in extreme cases, phalloplasty is a valuable option for patients to consider. In buried penis, the importance of careful assessment and, for the majority, a delay in surgery until puberty has completed is emphasised. In hypospadias patients, the variety of surgical procedures has complicated assessment of outcomes. It appears that true surgical success may be difficult to measure as many men who have had earlier operations are not reassessed in either puberty or adult life. There is also a brief discussion of acquired penile anomalies, including causation and treatment of lymphoedema, penile fracture/trauma, and priapism.

  10. 't Hooft anomaly matching for discrete symmetries

    International Nuclear Information System (INIS)

    Csaki, C.; Murayama, Hitoshi; Lawrence Berkeley National Lab., CA

    1998-05-01

    The authors show how to extend the 't Hooft anomaly matching conditions to discrete symmetries. They check these discrete anomally matching conditions on several proposed low-energy spectra of certain strongly interacting gauge theories. The excluded examples include the proposed chirally symmetric vacuum of pure N = 1 supersymmetric yang-Mills theories, certain non-supersymmetric confining theories and some self-dual N = 1 supersymmetric theories based on exceptional groups

  11. Tau anomaly and vectorlike families

    International Nuclear Information System (INIS)

    Babu, K.S.; Pati, J.C.; Zhang, X.

    1992-01-01

    The implications of a recently indicated increase in τ lifetime are discussed. It is stressed that the available experimental constraints (from δρ,ε 3 , and N ν , etc.) are satisfied most naturally if the indicated τ anomaly is attributed to the mixing of the τ family with a heavy vectorlike family Q L, R ' with masses ∼200 GeV to 2 TeV, which is a doublet of SU(2) R and singlet of SU(2) L , rather than with a heavy fourth family with standard chiral couplings. L↔R symmetry would imply that Q L, R ' is accompanied by the parity-conjugate family Q L, R which is a doublet of SU(2) L and singlet of SU(2) R . Two such vectorlike families, together with an increase in τ τ , are, in fact, crucial predictions of a recently proposed supersymmetric composite model that possesses many attractive features, in particular, explanations of the origin of diverse scales and family replication. In the context of such a model, it is noted that 3 an increase in τ τ due to mixing involving vectorlike families will necessarily imply a correlated decrease in neutrino counting N ν from the CERN e + e- collider LEP from 3. Such a decrease in N ν would be absent, however, if the τ anomaly is attributed to a mixing involving a standard fourth family with chiral couplings. Because of the seesaw nature of the mass matrix of the three chiral and two vectorlike families, that arises naturally in the model, departures from universality in the first two families as well as in bar bb and τ + τ - channels (linked to down flavors) are strongly suppressed, in accord with observations

  12. Hyades CN anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.A.; Twarog, B.A.

    1983-05-01

    Recent uvby photometric work indicating possible CN variation among main-sequence stars in the Hyades is tested. Comparison of Reticon spectra of normal stars of similar temperature to five anomalous CN candidates in the Hyades demonstrates that there is no significant difference between the spectra of the program and comparison stars for four of the anomalous CN candidates in the wavelength region of CN 4216. The observed spectral discrepancy for the fifth program star appears to be the result of an incorrect temperature index as compared to previous observations of the same star. The source of the photometric anomaly remains unexplained.

  13. Prediction of load threshold of fibre-reinforced laminated composite panels subjected to low velocity drop-weight impact using efficient data filtering techniques

    Directory of Open Access Journals (Sweden)

    Umar Farooq

    2015-01-01

    Full Text Available This work is concerned with physical testing of carbon fibrous laminated composite panels with low velocity drop-weight impacts from flat and round nose impactors. Eight, sixteen, and twenty-four ply panels were considered. Non-destructive damage inspections of tested specimens were conducted to approximate impact-induced damage. Recorded data were correlated to load–time, load–deflection, and energy–time history plots to interpret impact induced damage. Data filtering techniques were also applied to the noisy data that unavoidably generate due to limitations of testing and logging systems. Built-in, statistical, and numerical filters effectively predicted load thresholds for eight and sixteen ply laminates. However, flat nose impact of twenty-four ply laminates produced clipped data that can only be de-noised involving oscillatory algorithms. Data filtering and extrapolation of such data have received rare attention in the literature that needs to be investigated. The present work demonstrated filtering and extrapolation of the clipped data using Fast Fourier Convolution algorithm to predict load thresholds. Selected results were compared to the damage zones identified with C-scan and acceptable agreements have been observed. Based on the results it is proposed that use of advanced data filtering and analysis methods to data collected by the available resources has effectively enhanced data interpretations without resorting to additional resources. The methodology could be useful for efficient and reliable data analysis and impact-induced damage prediction of similar cases’ data.

  14. Seismic imaging of deep low-velocity zone beneath the Dead Sea basin and transform fault: Implications for strain localization and crustal rigidity

    Science.gov (United States)

    ten Brink, Uri S.; Al-Zoubi, A. S.; Flores, C.H.; Rotstein, Y.; Qabbani, I.; Harder, S.H.; Keller, Gordon R.

    2006-01-01

    New seismic observations from the Dead Sea basin (DSB), a large pull-apart basin along the Dead Sea transform (DST) plate boundary, show a low velocity zone extending to a depth of 18 km under the basin. The lower crust and Moho are not perturbed. These observations are incompatible with the current view of mid-crustal strength at low temperatures and with support of the basin's negative load by a rigid elastic plate. Strain softening in the middle crust is invoked to explain the isostatic compensation and the rapid subsidence of the basin during the Pleistocene. Whether the deformation is influenced by the presence of fluids and by a long history of seismic activity on the DST, and what the exact softening mechanism is, remain open questions. The uplift surrounding the DST also appears to be an upper crustal phenomenon but its relationship to a mid-crustal strength minimum is less clear. The shear deformation associated with the transform plate boundary motion appears, on the other hand, to cut throughout the entire crust. Copyright 2006 by the American Geophysical Union.

  15. NEW GUN CAPABILITY WITH INTERCHANGABLE BARRELS TO INVESTIGATE LOW VELOCITY IMPACT REGIMES AT THE LAWRENCE LIVERMORE NATIONAL LABORATORY HIGH EXPLOSIVES APPLICATIONS FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Vandersall, K S; Behn, A; Gresshoff, M; Jr., L F; Chiao, P I

    2009-09-16

    A new gas gun capability is being activated at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). The single stage light gas (dry air, nitrogen, or helium) gun has interchangeable barrels ranging from 25.4 mm to 76.2 mm in diameter with 1.8 meters in length and is being fabricated by Physics Applications, Inc. Because it is being used for safety studies involving explosives, the gun is planned for operation inside a large enclosed firing tank, with typical velocities planned in the range of 10-300 m/s. Three applications planned for this gun include: low velocity impact of detonator or detonator/booster assemblies with various projectile shapes, the Steven Impact test that involves impact initiation of a cased explosive target, and the Taylor impact test using a cylindrical explosive sample impacted onto a rigid anvil for fracture studies of energetic materials. A highlight of the gun features, outline on work in progress for implementing this capability, and discussion of the planned areas of research will be included.

  16. On the Interplay Between Adhesion Strength and Tensile Properties of Thermal Spray Coated Laminates—Part II: Low-Velocity Thermal Spray Coatings

    Science.gov (United States)

    Luo, Xiaotao; Smith, Gregory M.; Sampath, Sanjay

    2018-02-01

    In this two-part study, uniaxial tensile testing was used to evaluate coating/substrate bonding and compared with traditional ASTM C633 bond pull test results for thermal spray (TS) coated steel laminates. In Part I, the rationale, methodology, and applicability of the test to high-velocity TS coatings were demonstrated. In this Part II, the method was investigated for low-velocity TS processes (air plasma spray and arc spray) on equivalent materials. Ni and Ni-5wt.%Al coatings were deposited on steel substrates with three different roughness levels and tested using both uniaxial tensile and ASTM C633 methods. The results indicate the uniaxial tensile approach provides useful information about the nature of the coating/substrate bonding and goes beyond the traditional bond pull test in providing insightful information on the load sharing processes across the interface. Additionally, this proposed methodology alleviates some of the longstanding shortcomings and potentially reduces error associated with the traditional ASTM C633 test. The mechanisms governing the load transfer between the substrate and the coating were investigated, and the influence of Al in the coating material evaluated.

  17. Study of Impact Damage in PVA-ECC Beam under Low-Velocity Impact Loading Using Piezoceramic Transducers and PVDF Thin-Film Transducers.

    Science.gov (United States)

    Qi, Baoxin; Kong, Qingzhao; Qian, Hui; Patil, Devendra; Lim, Ing; Li, Mo; Liu, Dong; Song, Gangbing

    2018-02-24

    Compared to conventional concrete, polyvinyl alcohol fiber reinforced engineering cementitious composite (PVA-ECC) offers high-strength, ductility, formability, and excellent fatigue resistance. However, impact-induced structural damage is a major concern and has not been previously characterized in PVA-ECC structures. We investigate the damage of PVA-ECC beams under low-velocity impact loading. A series of ball-drop impact tests were performed at different drop weights and heights to simulate various impact energies. The impact results of PVA-ECC beams were compared with mortar beams. A combination of polyvinylidene fluoride (PVDF) thin-film sensors and piezoceramic-based smart aggregate were used for impact monitoring, which included impact initiation and crack evolution. Short-time Fourier transform (STFT) of the signal received by PVDF thin-film sensors was performed to identify impact events, while active-sensing approach was utilized to detect impact-induced crack evolution by the attenuation of a propagated guided wave. Wavelet packet-based energy analysis was performed to quantify failure development under repeated impact tests.

  18. An application of liquid sublayer dryout mechanism to the prediction of critical heat flux under low pressure and low velocity conditions in round tubes

    International Nuclear Information System (INIS)

    Lee, Kwang-Won; Yang, Jae-Young; Baik, Se-Jin

    1997-01-01

    Based on several experimental evidences for nucleate boiling in annular film and the existence of residual liquid film flow rate at the critical heat flux (CHF) location, the liquid sublayer dryout (LSD) mechanism under annular film is firstly introduced to evaluate the CHF data at low pressure and low velocity (LPLV) conditions, which would not be predicted by a normal annular film dryout (AFD) model. In this study, the CHF occurrence due to annular film separation or breaking down is phenomenologically modelled by applying the LSD mechanism to this situation. In this LSD mechanism, the liquid sublayer thickness, the incoming liquid velocity to the liquid sublayer, and the axial distance from the onset of annular flow to the CHF location are used as the phenomena-controlling parameters. From the model validation on the 1406 CHF data points ranging over P = 0.1 - 2 MPa, G = 4 - 499 kg/m 2 s, L/D = 4 - 402, most of CHF data (more than 1000 points) are predicted within ±30% error bounds by the LSD mechanism. However, some calculation results that critical qualities are less than 0.4 are considerably overestimated by this mechanism. These overpredictions seem to be caused by inadequate CHF mechanism classification criteria and an insufficient consideration of the flow instability effect on CHF. Further studies for a new classification criterion screening the CHF data affected by flow instabilities and a new bubble detachment model for LPLV conditions are needed to improve the model accuracy. (author)

  19. Relationships among neurological functioning, intelligence quotients, and physical anomalies.

    Science.gov (United States)

    Marcus, J; Hans, S L; Byhouwer, B; Norem, J

    1985-01-01

    The relationships among IQ, neurological signs, and minor physical anomalies--all measures of central nervous system status--were assessed in the index and control children of the study. The strongest correlation was found between neurological functioning and IQ; the relationship between anomalies and neurological functioning was less strong; and no relationship was found between anomalies and IQ. Consistently, the most poorly functioning children tended to be offspring of schizophrenic patients (index cases), although the same children did not always perform poorly on all tests. What emerges is a set of clusters of individuals with varying combinations of functional/developmental problems.

  20. Pregnancy outcome and Ebstein's anomaly.

    OpenAIRE

    Donnelly, J E; Brown, J M; Radford, D J

    1991-01-01

    BACKGROUND--Ebstein's anomaly is an uncommon congenital cardiac abnormality that may be associated with cyanosis and arrhythmias. For those female patients with the anomaly who survive to adult life there is little information available about pregnancy, maternal complications, and fetal outcome. This study was designed to address this issue so that these patients can receive appropriate advice and management. METHODS AND RESULTS--Forty two pregnancies in 12 women with Ebstein's anomaly were s...

  1. Anomalies in Economics and Finance

    OpenAIRE

    Christopher L. Gilbert

    2010-01-01

    The term “anomaly” played a crucial role in Thomas Kuhn’s characterization of scientific progress. For Kuhn, an anomaly is a puzzle which challenges an accepted paradigm. Puzzles only achieve anomalous status once an alternative paradigm becomes available which allows explanation of the puzzle. Anomalies were introduced into the finance literature by Michael Jensen but more as resolvable puzzles than Kuhnian anomalies. They entered economics via Richard Thaler who saw behavioural economics as...

  2. Congenital Anomalies among Live Births

    OpenAIRE

    Vivian Rosa Vázquez Martínez; Cristobal Jorge Torres González; Alina Luisa Díaz Dueñas; Grisel Torres Vázquez; Dariel Diaz Díaz; Rafael de la Rosa López

    2014-01-01

    Background: congenital anomalies contribute significantly to mortality during early stages of life; they are the leading cause of infant death in developed countries.Objective: to determine the characteristics of congenital anomalies among live births. Methods: a descriptive study was conducted in the province of Cienfuegos in 2012. Thirty-seven women who had live-born neonates with congenital anomalies were studied. The variables analyzed were: parental age, skin color, order of birth, famil...

  3. Seismic Velocity Anomalies beneath Tatun Volcano Group, Northern Taiwan

    Science.gov (United States)

    Lin, Tzu-yu; Lin, Cheng-Horng; Yang, Tsanyao Frank; Chang, Li-Chin

    2015-04-01

    Volcanic eruption has been a natural disaster for human society. Taiwan is located in the Pacific Ring of Fire. Although there is no obvious phenomenon of volcanic activity in Taiwan, some volcanoes need to be monitored, especially the Tatun Volcano Group (TVG), which exhibits very active hydrothermal activity, is located on the tip of southwestern Ryukyu arc. TVG is about 15 km north to Taipei, capital of Taiwan, and is nearby two nuclear power plants along the northern coast of Taiwan. If TVG erupts, there must be a serious impact and damage to Taiwan. Since TVG is located within the Yangmingshan National Park, any artificial seismic source is not allowed to estimate possible eruption site and the degree of volcanic disaster. Instead, we use natural seismic waves generated by earthquakes to image the possible velocity anomaly of magma chamber and/or hydrothermal system beneath TVG. We systematically compare the differences of arrival times generated by some local earthquakes and recorded at 42 seismic stations in 2014 for finding any low-velocity zone within the crust. The results show that the arrival times always appeared significant delay at some particular seismic stations, such as Chi-Hsin-Shan (CHS), Siao-You-Keng (SYK) and some other stations at TVG, no matter where the earthquakes occurred. It implies that possible low-velocity zones, which could be the location of magma chamber and/or active hydrothermal system, exist beneath the CHS and SYK areas. This feature is generally consistent with the clustered micro-earthquakes in the shallow crust beneath the CHS area in the last decade.

  4. CHAMP Magnetic Anomalies of the Antarctic Crust

    Science.gov (United States)

    Kim, Hyung Rae; Gaya-Pique, Luis R.; vonFrese, Ralph R. B.; Taylor, Patrick T.; Kim, Jeong Woo

    2003-01-01

    Regional magnetic signals of the crust are strongly masked by the core field and its secular variations components and hence difficult to isolate in the satellite measurements. In particular, the un-modeled effects of the strong auroral external fields and the complicated- behavior of the core field near the geomagnetic poles conspire to greatly reduce the crustal magnetic signal-to-noise ratio in the polar regions relative to the rest of the Earth. We can, however, use spectral correlation theory to filter the static lithospheric and core field components from the dynamic external field effects. To help isolate regional lithospheric from core field components, the correlations between CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations can also be exploited.. Employing these procedures, we processed the CHAMP magnetic observations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Orsted and noisier Magsat observations, the CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intracrustal magnetic features and crustal thickness variations of the Antarctic.

  5. Low velocity impact response of carbon fiber laminates fabricated by pulsed infusion: A review of damage investigation and semi-empirical models validation

    Science.gov (United States)

    Antonucci, V.; Caputo, F.; Ferraro, P.; Langella, A.; Lopresto, V.; Pagliarulo, V.; Ricciardi, M. R.; Riccio, A.; Toscano, C.

    2016-02-01

    The research reported in this paper was aimed mainly to investigate the different NDE techniques on specimens made by a new process labeled as "pulsed infusion", very crucial for voids content under critical loading conditions. The impact load, in fact, is critical for composite laminates due to their anisotropy, in particular in extreme temperature conditions due to their brittleness. An additional and very relevant aim was to collect a large number of experimental results to supply useful information for the numerical models needed to simulate the dynamic behavior of composite laminates. At the aim to investigate the response under dynamic loads of laminates fabricated by a new vacuum assisted technology labeled as "pulsed infusion", rectangular carbon fiber composite specimens were subjected to low velocity impact tests. Experimental tests up to complete penetration and at different energy levels, were carried out by a modular falling weight tower. All the parameters related to the phenomenon, like penetration energy, maximum force and indentation depths, were used to validate existing semi-empirical and numerical models. The largely used ultra sound technique (US) was adopted to investigate the delamination together with the thermo graphic technique. The results of the measurements were compared with data obtained on the same specimens by holographic analysis (ESPI). One of the scope was to investigate the crucial internal impact damage and assess the ability of an unconventional ND system (ESPI) in giving right information about non-visual damage generated inside composite laminates subjected to dynamic loads. Moreover, some of the specimens were cut to allow the fractographic analysis. The efficiency of the above mentioned new fabrication technology was studied also comparing the results with measurements from literature on impacted autoclave cured laminates. By the comparison between the results, good agreements were found denoting the efficiency and the

  6. An utilization of liquid sublayer dryout mechanism in predicting critical heat flux under low pressure and low velocity conditions in round tubes

    International Nuclear Information System (INIS)

    Lee, Kwang-Won; Baik, Se-Jin; Ro, Tae-Sun

    2000-01-01

    From a theoretical assessment of extensive critical heat flux (CHF) data under low pressure and low velocity (LPLV) conditions, it was found out that lots of CHF data would not be well predicted by a normal annular film dryout (AFD) mechanism, although their flow patterns were identified as annular-mist flow. To predict these CHF data, a liquid sublayer dryout (LSD) mechanism has been newly utilized in developing the mechanistic CHF model based on each identified CHF mechanism. This mechanism postulates that the CHF occurrence is caused by dryout of the thin liquid sublayer resulting from the annular film separation or breaking down due to nucleate boiling in annular film or hydrodynamic fluctuation. In principle, this mechanism well supports the experimental evidence of residual film flow rate at the CHF location, which can not be explained by the AFD mechanism. For a comparative assessment of each mechanism, the CHF model based on the LSD mechanism is developed together with that based on the AFD mechanism. The validation of these models is performed on the 1406 CHF data points ranging over P=0.1-2 MPa, G=4-499 kg m -2 s -1 , L/D=4-402. This model validation shows that 1055 and 231 CHF data are predicted within ±30 error bound by the LSD mechanism and the AFD mechanism, respectively. However, some CHF data whose critical qualities are <0.4 or whose tube length-to-diameter ratios are <70 are considerably overestimated by the CHF model based on the LSD mechanism. These overestimations seem to be caused by an inadequate CHF mechanism classification and an insufficient consideration of the flow instability effect on CHF. Further studies for a new classification criterion screening the CHF data affected by flow instabilities as well as a new bubble detachment model for LPLV conditions, are needed to improve the model accuracy.

  7. [Developmental venous anomaly (DVA)].

    Science.gov (United States)

    Zimmer, A; Hagen, T; Ahlhelm, F; Viera, J; Reith, W; Schulte-Altedorneburg, G

    2007-10-01

    As congenital anatomic variants of venous drainage, developmental venous anomalies (DVA) represent up to 60% of all cerebral vascular malformations. The prior term "venous angioma" is a misnomer implicating an abnormal vascular structure with an increased bleeding risk. They are often found incidentally and are hardly ever symptomatic. Their morphologic characteristics are dilated vessels in the white matter, which converge on a greater collector vein, forming the typical caput medusae. They drain into the superficial or deep venous system. The frequent association with other, potentially bleeding-prone vascular malformations is clinically relevant, in particular cavernous angioma, which might require therapeutic action. Therefore, coincident vascular lesions need to be actively sought by appropriate additional imaging techniques.

  8. Water radon anomaly fields

    Energy Technology Data Exchange (ETDEWEB)

    Yin, H.

    1980-01-01

    A striking aspect of water radon levels in relation to earthquakes is that before the Tangshan quake there was a remarkable synchronicity of behavior of many wells within 200 km of Tangshan. However, for many wells anomalous values persisted after the earthquake, particularly outside the immediate region of the quake. It is clear that radon may be produced by various processes; some candidates are pressure, shear, vibration, temperature and pressure, mixing of water-bearing strata, breakdown of mineral crystal structure, and the like, although it is not clear which of these are primary. It seems that a possible explanation of the persistence of the anomaly in the case of Tangshan may be that the earthquake released strain in the vicinity of Tangshan but increased it further along the geological structures involved, thus producing a continued radon buildup.

  9. Strongly nonlinear wave dynamics in a chain of polymer coated beads

    OpenAIRE

    Daraio, C.; Nesterenko, V. F.

    2006-01-01

    Strongly nonlinear phononic crystals were assembled from a chain of Parylene-C coated steel spheres in a polytetrafluoroethylene (PTFE) holder. This system exhibits strongly nonlinear properties and extends the range of materials supporting "sonic vacuum" type behavior. The combination of a high density core and a soft (low elastic modulus) coating ensures a relatively low velocity of wave propagation. The beads contact interaction caused by the deformation of the Parylene coating can be desc...

  10. Axial anomaly at finite temperature

    International Nuclear Information System (INIS)

    Chaturvedi, S.; Gupte, Neelima; Srinivasan, V.

    1985-01-01

    The Jackiw-Bardeen-Adler anomaly for QED 4 and QED 2 are calculated at finite temperature. It is found that the anomaly is independent of temperature. Ishikawa's method [1984, Phys. Rev. Lett. vol. 53 1615] for calculating the quantised Hall effect is extended to finite temperature. (author)

  11. Anomaly Structure of Regularized Supergravity

    Science.gov (United States)

    Butter, Daniel; Gaillard, Mary K.

    2015-01-01

    On-shell Pauli-Villars regularization of the one-loop divergences of supergravity theories is used to study the anomaly structure of supergravity and the cancellation of field theory anomalies under a U (1 ) gauge transformation and under the T -duality group of modular transformations in effective supergravity theories with three Kähler moduli Ti obtained from orbifold compactification of the weakly coupled heterotic string. This procedure requires constraints on the chiral matter representations of the gauge group that are consistent with known results from orbifold compactifications. Pauli-Villars (PV) regulator fields allow for the cancellation of all quadratic and logarithmic divergences, as well as most linear divergences. If all linear divergences were canceled, the theory would be anomaly free, with noninvariance of the action arising only from Pauli-Villars masses. However there are linear divergences associated with nonrenormalizable gravitino/gaugino interactions that cannot be canceled by PV fields. The resulting chiral anomaly forms a supermultiplet with the corresponding conformal anomaly, provided the ultraviolet cutoff has the appropriate field dependence, in which case total derivative terms, such as Gauss-Bonnet, do not drop out from the effective action. The anomalies can be partially canceled by the four-dimensional version of the Green-Schwarz mechanism, but additional counterterms, and/or a more elaborate set of Pauli-Villars fields and couplings, are needed to cancel the full anomaly, including D -term contributions to the conformal anomaly that are nonlinear in the parameters of the anomalous transformations.

  12. CRANIOVERTEBRAL JUNCTION ANOMALIES SEEN AT ...

    African Journals Online (AJOL)

    hi-tech

    2000-03-03

    Mar 3, 2000 ... anomalies that give rise to symptoms in this area are basilar impression, occipitalisation of the atlas, odontoid process abnormalities and atlanto-axial dislocation. Neuromeningeal anomalies in this region include Arnold-. Chiari malformation, syringomyelia and basal arachnoiditis. The clinical presentation ...

  13. What is a Timing Anomaly?

    DEFF Research Database (Denmark)

    Cassez, Franck; Hansen, Rene Rydhof; Olesen, Mads Chr.

    2012-01-01

    difficult. We examine previous definitions of timing anomalies, and identify examples where they do not align with common observations. We then provide a definition for consistently slower hardware traces that can be used to define timing anomalies and aligns with common observations....

  14. Hepatic and postrenal segment anomalies of inferior vena cava

    International Nuclear Information System (INIS)

    Choe, Yeon Hyeon; Park, Jae Hyung; Yeon, Kyung Mo; Han, Man Chung

    1986-01-01

    Postrenal segment anomalies of inferior vena cava such as bilateral inferior vena cava and left-sided inferior vena cava can simulate lymphadenopathy on CT scan and these anomalous veins need consideration in retroperitoneal operations such as procedures for prevention of venous embolism, splenorenal shunt operation and aortic prosthetic replacement. Retrocaval ureter is a rare cause of obstructive uropathy or medical deviation of ureter. We analyzed 16 cases of postrenal segment anomalies diagnosed by CT, vena cavography, retrograde pyelography and ultrasonography including six rare positional anomalies at hepatic segment of inferior vena cava diagnosed by cardiac angiography. The results were as follows. 1. Postrenal segment anomalies were 6 cases of bilateral IVC, 8 cases of left-sided IVC and 2 cases of retrocaval ureters. On CT scan, 3 cases of bilateral IVC and 4 cases of left-sided IVC were accompanied by malignant tumors, but caval veins could be discriminated from enlarged nodes because of continuous tubular nature of vein on consecutive sections with homogeneous strong enhancement. Two cases of retrocaval ureters showed hydroureteronephrosis due to ureteral compression by IVC. 2. Hepatic segment anomalies were 6 cases. Five cases of IVC on left side of vertebra crossed midline at live to enter right-sided right atrium and one case of IVC on right side crossed midline to enter left-sided right atrium. Four cases of complex cardiac anomalies, 4 cases of annapolis and 2 cases of situs ambiguous were associated with these anomalies.

  15. Impacts of the IOD-associated temperature and salinity anomalies on the intermittent equatorial undercurrent anomalies

    Science.gov (United States)

    Li, Junde; Liang, Chujin; Tang, Youmin; Liu, Xiaohui; Lian, Tao; Shen, Zheqi; Li, Xiaojing

    2017-11-01

    The study of Equatorial Undercurrent (EUC) has attracted a broad attention in recent years due to its strong response and feedback to the Indian Ocean Dipole. In this paper, we first produce a high-quality simulation of three-dimensional temperature, salinity and zonal current simulation from 1982 to 2014, using a high-resolution ocean general circulation model. On this basis, with two sensitivity experiments, we investigate the role of temperature and salinity anomalies in driving and enhancing the EUC during the positive IOD events by examining the variation of the EUC seasonal cycle and diagnosing the zonal momentum budget along the equatorial Indian Ocean. Our results show that during January-March, the EUC can appear along the entire equatorial Indian Ocean in all years, but during August-November, the EUC can appear and reach the eastern Indian Ocean only during the positive IOD events. The zonal momentum budget analysis indicates that the pressure gradient force contributes most to the variation of the eastward acceleration of zonal currents in the subsurface. During the positive IOD events, strong negative subsurface temperature anomalies exist in the eastern Indian Ocean, with negative surface salinity anomalies in the central and eastern Indian Ocean, resulting in a large pressure gradient force to drive EUC during the August-November. Further, the results of two sensitivity experiments indicate that the temperature anomalies significantly impact the pressure gradient force, playing a leading role in driving the EUC, while the surface salinity anomalies can secondarily help to intensify the eastward EUC through increasing the zonal density gradient in the eastern Indian Ocean and impacting the vertical momentum advection in the subsurface.

  16. Dispersion Energy Analysis of Rayleigh and Love Waves in the Presence of Low-Velocity Layers in Near-Surface Seismic Surveys

    Science.gov (United States)

    Mi, Binbin; Xia, Jianghai; Shen, Chao; Wang, Limin

    2017-10-01

    High-frequency surface-wave analysis methods have been effectively and widely used to determine near-surface shear (S) wave velocity. To image the dispersion energy and identify different dispersive modes of surface waves accurately is one of key steps of using surface-wave methods. We analyzed the dispersion energy characteristics of Rayleigh and Love waves in near-surface layered models based on numerical simulations. It has been found that if there is a low-velocity layer (LVL) in the half-space, the dispersion energy of Rayleigh or Love waves is discontinuous and ``jumping'' appears from the fundamental mode to higher modes on dispersive images. We introduce the guided waves generated in an LVL (LVL-guided waves, a trapped wave mode) to clarify the complexity of the dispersion energy. We confirm the LVL-guided waves by analyzing the snapshots of SH and P-SV wavefield and comparing the dispersive energy with theoretical values of phase velocities. Results demonstrate that LVL-guided waves possess energy on dispersive images, which can interfere with the normal dispersion energy of Rayleigh or Love waves. Each mode of LVL-guided waves having lack of energy at the free surface in some high frequency range causes the discontinuity of dispersive energy on dispersive images, which is because shorter wavelengths (generally with lower phase velocities and higher frequencies) of LVL-guided waves cannot penetrate to the free surface. If the S wave velocity of the LVL is higher than that of the surface layer, the energy of LVL-guided waves only contaminates higher mode energy of surface waves and there is no interlacement with the fundamental mode of surface waves, while if the S wave velocity of the LVL is lower than that of the surface layer, the energy of LVL-guided waves may interlace with the fundamental mode of surface waves. Both of the interlacements with the fundamental mode or higher mode energy may cause misidentification for the dispersion curves of surface

  17. Dispersion Energy Analysis of Rayleigh and Love Waves in the Presence of Low-Velocity Layers in Near-Surface Seismic Surveys

    Science.gov (United States)

    Mi, Binbin; Xia, Jianghai; Shen, Chao; Wang, Limin

    2018-03-01

    High-frequency surface-wave analysis methods have been effectively and widely used to determine near-surface shear (S) wave velocity. To image the dispersion energy and identify different dispersive modes of surface waves accurately is one of key steps of using surface-wave methods. We analyzed the dispersion energy characteristics of Rayleigh and Love waves in near-surface layered models based on numerical simulations. It has been found that if there is a low-velocity layer (LVL) in the half-space, the dispersion energy of Rayleigh or Love waves is discontinuous and ``jumping'' appears from the fundamental mode to higher modes on dispersive images. We introduce the guided waves generated in an LVL (LVL-guided waves, a trapped wave mode) to clarify the complexity of the dispersion energy. We confirm the LVL-guided waves by analyzing the snapshots of SH and P-SV wavefield and comparing the dispersive energy with theoretical values of phase velocities. Results demonstrate that LVL-guided waves possess energy on dispersive images, which can interfere with the normal dispersion energy of Rayleigh or Love waves. Each mode of LVL-guided waves having lack of energy at the free surface in some high frequency range causes the discontinuity of dispersive energy on dispersive images, which is because shorter wavelengths (generally with lower phase velocities and higher frequencies) of LVL-guided waves cannot penetrate to the free surface. If the S wave velocity of the LVL is higher than that of the surface layer, the energy of LVL-guided waves only contaminates higher mode energy of surface waves and there is no interlacement with the fundamental mode of surface waves, while if the S wave velocity of the LVL is lower than that of the surface layer, the energy of LVL-guided waves may interlace with the fundamental mode of surface waves. Both of the interlacements with the fundamental mode or higher mode energy may cause misidentification for the dispersion curves of surface

  18. Gravity anomalies without geomagnetic disturbances interfere with pigeon homing--a GPS tracking study.

    Science.gov (United States)

    Blaser, Nicole; Guskov, Sergei I; Entin, Vladimir A; Wolfer, David P; Kanevskyi, Valeryi A; Lipp, Hans-Peter

    2014-11-15

    The gravity vector theory postulates that birds determine their position to set a home course by comparing the memorized gravity vector at the home loft with the local gravity vector at the release site, and that they should adjust their flight course to the gravity anomalies encountered. As gravity anomalies are often intermingled with geomagnetic anomalies, we released experienced pigeons from the center of a strong circular gravity anomaly (25 km diameter) not associated with magnetic anomalies and from a geophysical control site, equidistant from the home loft (91 km). After crossing the border zone of the anomaly--expected to be most critical for pigeon navigation--they dispersed significantly more than control birds, except for those having met a gravity anomaly en route. These data increase the credibility of the gravity vector hypothesis. © 2014. Published by The Company of Biologists Ltd.

  19. Coronary Artery Anomalies in Animals.

    Science.gov (United States)

    Scansen, Brian A

    2017-04-12

    Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

  20. Reliability of CHAMP Anomaly Continuations

    Science.gov (United States)

    vonFrese, Ralph R. B.; Kim, Hyung Rae; Taylor, Patrick T.; Asgharzadeh, Mohammad F.

    2003-01-01

    CHAMP is recording state-of-the-art magnetic and gravity field observations at altitudes ranging over roughly 300 - 550 km. However, anomaly continuation is severely limited by the non-uniqueness of the process and satellite anomaly errors. Indeed, our numerical anomaly simulations from satellite to airborne altitudes show that effective downward continuations of the CHAMP data are restricted to within approximately 50 km of the observation altitudes while upward continuations can be effective over a somewhat larger altitude range. The great unreliability of downward continuation requires that the satellite geopotential observations must be analyzed at satellite altitudes if the anomaly details are to be exploited most fully. Given current anomaly error levels, joint inversion of satellite and near- surface anomalies is the best approach for implementing satellite geopotential observations for subsurface studies. We demonstrate the power of this approach using a crustal model constrained by joint inversions of near-surface and satellite magnetic and gravity observations for Maude Rise, Antarctica, in the southwestern Indian Ocean. Our modeling suggests that the dominant satellite altitude magnetic anomalies are produced by crustal thickness variations and remanent magnetization of the normal polarity Cretaceous Quiet Zone.

  1. Gravitational anomaly and transport phenomena.

    Science.gov (United States)

    Landsteiner, Karl; Megías, Eugenio; Pena-Benitez, Francisco

    2011-07-08

    Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficient. The gravitational anomaly gives rise to an anomalous vortical effect even for an uncharged fluid.

  2. Quantum topology and global anomalies

    CERN Document Server

    Baadhio, R A

    1996-01-01

    Anomalies are ubiquitous features in quantum field theories. They can ruin the consistency of such theories and put significant restrictions on their viability, especially in dimensions higher than four. Global gauge and gravitational anomalies are to date, one of the scant powerful and probing tools available to physicists in the pursuit of uniqueness.This monograph is one of the very few that specializes in the study of global anomalies in quantum field theories. A discussion of various issues associated to three dimensional physics - the Chern-Simons-Witten theories - widen the scope of thi

  3. Anomalies in Flavour physics

    CERN Document Server

    Chrzaszcz, Marcin Jakub

    2015-01-01

    LHCb is measuring more and more deviations in electroweak penguin measurements, both in the angular observables (like P5') and the branching fractions. Furthermore, there are strong hints of lepton universality breaking in semileptonic decays. This talk aims to present the results of these measurements and the implications for new physics. A result of a global fit will be presented.

  4. Obstetric consequences of uterovaginal anomalies

    International Nuclear Information System (INIS)

    Rock, J.A.; Schlaff, W.D.

    1985-01-01

    This review discusses the diagnosis and classification of utero-vaginal anomalies as well as obstetric considerations in their management. Diagnosis is usually made by hysterosalpingography antepartum. Ultrasonography is also recommended. 40 references, 10 figures, 9 tables

  5. Dimensional reduction in anomaly mediation

    Science.gov (United States)

    Boyda, Ed; Murayama, Hitoshi; Pierce, Aaron

    2002-04-01

    We offer a guide to dimensional reduction in theories with anomaly-mediated supersymmetry breaking. Evanescent operators proportional to ɛ arise in the bare Lagrangian when it is reduced from d=4 to d=4-2ɛ dimensions. In the course of a detailed diagrammatic calculation, we show that inclusion of these operators is crucial. The evanescent operators conspire to drive the supersymmetry-breaking parameters along anomaly-mediation trajectories across heavy particle thresholds, guaranteeing the ultraviolet insensitivity.

  6. Gravitational anomaly and transport phenomena

    OpenAIRE

    Landsteiner, Karl

    2011-01-01

    Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficie...

  7. Sharing AIS Related Anomalies (SARA)

    Science.gov (United States)

    2016-03-01

    misconfiguration and intentional misuse. These unintended behaviours generate an abundance of anomalies that the security community has an interest in monitoring...to end-user needs and thus be adopted by them. This section is organised as follows : • Section 2.1 describes the strategy used to identify potential...intrinsic and behavioural . Anomalies tagged and reported by TimeCaster can be found in the patent claim (see [13]) and can be augmented. 2.3.7 exactEarth

  8. The use of Compton scattering in detecting anomaly in soil-possible use in pyromaterial detection

    Science.gov (United States)

    Abedin, Ahmad Firdaus Zainal; Ibrahim, Noorddin; Zabidi, Noriza Ahmad; Demon, Siti Zulaikha Ngah

    2016-01-01

    The Compton scattering is able to determine the signature of land mine detection based on dependency of density anomaly and energy change of scattered photons. In this study, 4.43 MeV gamma of the Am-Be source was used to perform Compton scattering. Two detectors were placed between source with distance of 8 cm and radius of 1.9 cm. Detectors of thallium-doped sodium iodide NaI(TI) was used for detecting gamma ray. There are 9 anomalies used in this simulation. The physical of anomaly is in cylinder form with radius of 10 cm and 8.9 cm height. The anomaly is buried 5 cm deep in the bed soil measured 80 cm radius and 53.5 cm height. Monte Carlo methods indicated the scattering of photons is directly proportional to density of anomalies. The difference between detector response with anomaly and without anomaly namely contrast ratio values are in a linear relationship with density of anomalies. Anomalies of air, wood and water give positive contrast ratio values whereas explosive, sand, concrete, graphite, limestone and polyethylene give negative contrast ratio values. Overall, the contrast ratio values are greater than 2 % for all anomalies. The strong contrast ratios result a good detection capability and distinction between anomalies.

  9. Space weather and space anomalies

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2005-11-01

    Full Text Available A large database of anomalies, registered by 220 satellites in different orbits over the period 1971-1994 has been compiled. For the first time, data from 49 Russian Kosmos satellites have been included in a statistical analysis. The database also contains a large set of daily and hourly space weather parameters. A series of statistical analyses made it possible to quantify, for different satellite orbits, space weather conditions on the days characterized by anomaly occurrences. In particular, very intense fluxes (>1000 pfu at energy >10 MeV of solar protons are linked to anomalies registered by satellites in high-altitude (>15000 km, near-polar (inclination >55° orbits typical for navigation satellites, such as those used in the GPS network, NAVSTAR, etc. (the rate of anomalies increases by a factor ~20, and to a much smaller extent to anomalies in geostationary orbits, (they increase by a factor ~4. Direct and indirect connections between anomaly occurrence and geomagnetic perturbations are also discussed.

  10. Multiple-Instance Learning for Anomaly Detection in Digital Mammography.

    Science.gov (United States)

    Quellec, Gwenole; Lamard, Mathieu; Cozic, Michel; Coatrieux, Gouenou; Cazuguel, Guy

    2016-07-01

    This paper describes a computer-aided detection and diagnosis system for breast cancer, the most common form of cancer among women, using mammography. The system relies on the Multiple-Instance Learning (MIL) paradigm, which has proven useful for medical decision support in previous works from our team. In the proposed framework, breasts are first partitioned adaptively into regions. Then, features derived from the detection of lesions (masses and microcalcifications) as well as textural features, are extracted from each region and combined in order to classify mammography examinations as "normal" or "abnormal". Whenever an abnormal examination record is detected, the regions that induced that automated diagnosis can be highlighted. Two strategies are evaluated to define this anomaly detector. In a first scenario, manual segmentations of lesions are used to train an SVM that assigns an anomaly index to each region; local anomaly indices are then combined into a global anomaly index. In a second scenario, the local and global anomaly detectors are trained simultaneously, without manual segmentations, using various MIL algorithms (DD, APR, mi-SVM, MI-SVM and MILBoost). Experiments on the DDSM dataset show that the second approach, which is only weakly-supervised, surprisingly outperforms the first approach, even though it is strongly-supervised. This suggests that anomaly detectors can be advantageously trained on large medical image archives, without the need for manual segmentation.

  11. Pre-seismic anomalies from optical satellite observations: a review

    Science.gov (United States)

    Jiao, Zhong-Hu; Zhao, Jing; Shan, Xinjian

    2018-04-01

    Detecting various anomalies using optical satellite data prior to strong earthquakes is key to understanding and forecasting earthquake activities because of its recognition of thermal-radiation-related phenomena in seismic preparation phases. Data from satellite observations serve as a powerful tool in monitoring earthquake preparation areas at a global scale and in a nearly real-time manner. Over the past several decades, many new different data sources have been utilized in this field, and progressive anomaly detection approaches have been developed. This paper reviews the progress and development of pre-seismic anomaly detection technology in this decade. First, precursor parameters, including parameters from the top of the atmosphere, in the atmosphere, and on the Earth's surface, are stated and discussed. Second, different anomaly detection methods, which are used to extract anomalous signals that probably indicate future seismic events, are presented. Finally, certain critical problems with the current research are highlighted, and new developing trends and perspectives for future work are discussed. The development of Earth observation satellites and anomaly detection algorithms can enrich available information sources, provide advanced tools for multilevel earthquake monitoring, and improve short- and medium-term forecasting, which play a large and growing role in pre-seismic anomaly detection research.

  12. Spontaneous breaking of conformal invariance and trace anomaly matching

    International Nuclear Information System (INIS)

    Schwimmer, A.; Theisen, S.

    2011-01-01

    We argue that when conformal symmetry is spontaneously broken the trace anomalies in the broken and unbroken phases are matched. This puts strong constraints on the various couplings of the dilaton. Using the uniqueness of the effective action for the Goldstone supermultiplet for broken N=1 superconformal symmetry the dilaton effective action is calculated.

  13. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jung Kyu; Cho, Jeong Yeon; Lee, Young Ho; Kim, Ei Jeong; Chun, Yi Kyeong [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    Focal musculoskeletal anomalies are various and may be an isolated finding or may be found in conjunction with numerous associations, including genetic syndromes, Karyotype abnormals, central nervous system anomalies and other general musculoskeletal disorders. Early prenatal diagnosis of these focal musculoskeletal anomalies nor only affects prenatal care and postnatal outcome but also helps in approaching other numerous associated anomalies.

  14. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    International Nuclear Information System (INIS)

    Ryu, Jung Kyu; Cho, Jeong Yeon; Lee, Young Ho; Kim, Ei Jeong; Chun, Yi Kyeong

    2002-01-01

    Focal musculoskeletal anomalies are various and may be an isolated finding or may be found in conjunction with numerous associations, including genetic syndromes, Karyotype abnormals, central nervous system anomalies and other general musculoskeletal disorders. Early prenatal diagnosis of these focal musculoskeletal anomalies nor only affects prenatal care and postnatal outcome but also helps in approaching other numerous associated anomalies.

  15. Anomalie de developpement sexuel : Un cas de ...

    African Journals Online (AJOL)

    Mots clés : Pseudohermaphrodisme masculin, anomalie de développement sexuel XY, caryotype, sexe social. Anomaly of sexual development: a case of masculine pseudohermaphrodism or anomaly of development sexual XY. The anomalies of the sexual development must be detected to the birth where they constitute ...

  16. Coronary Artery Anomalies in Animals

    Directory of Open Access Journals (Sweden)

    Brian A. Scansen

    2017-04-01

    Full Text Available Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

  17. MAGSAT anomaly map and continental drift

    Science.gov (United States)

    Lemouel, J. L. (Principal Investigator); Galdeano, A.; Ducruix, J.

    1981-01-01

    Anomaly maps of high quality are needed to display unambiguously the so called long wave length anomalies. The anomalies were analyzed in terms of continental drift and the nature of their sources is discussed. The map presented confirms the thinness of the oceanic magnetized layer. Continental magnetic anomalies are characterized by elongated structures generally of east-west trend. Paleomagnetic reconstruction shows that the anomalies found in India, Australia, and Antarctic exhibit a fair consistency with the African anomalies. It is also shown that anomalies are locked under the continents and have a fixed geometry.

  18. A combined analysis of basaltic melting and shear wave velocity anomalies to constrain dynamic support of western North America

    Science.gov (United States)

    Klöcking, Marthe; White, Nicky; Maclennan, John; Fitton, Godfrey

    2017-04-01

    The region of western North America that encompasses the Basin and Range Province, the Snake River Plain and the Colorado Plateau is about 2 km higher than cratonic North America. This topographic difference broadly coincides with variations in lithospheric thickness (i.e. Mexico, and inverse modeling of regional drainage networks together suggest that this regional uplift occurred during Cenozoic time in at least two discrete phases. Earthquake tomographic models have imaged low velocity material beneath the bulk of western North America, including a ring-shaped anomaly encompassing the Colorado Plateau itself. Basaltic magmatism coincides with these low velocity zones and indicates an overall increase in melt volume at 40 Ma, as well as an abrupt change from lithospheric to asthenospheric signatures at 5 Ma. To investigate the quantitative relationship between seismic velocity anomalies and basaltic magmatism, we have analyzed >260 samples from volcanic centers throughout western North America for major, trace and rare earth elements using ICP-MS and XRF techniques. For asthenospheric samples, we observe a correlation between slow shear wave velocity anomalies and basaltic geochemistry. Using a combination of petrologic observations, forward and inverse modeling of major and rare earth elements, and shear wave velocity anomalies from tomographic models, we determine depth of melting and melt fraction. We explore the possibility that volatiles, anomalous source composition and/or temperature can give rise to basaltic magmatism and regional uplift. We then calculate mantle temperatures from shear wave velocity profiles beneath each volcanic field. In this way, we exploit a variety of approaches to constrain lithospheric thickness and mantle potential temperature. Our combined geochemical and geophysical results yield excess temperatures of 50-80 °C beneath a 60 km thin lithospheric plate. A dynamic topographic model of progressive lithospheric erosion over

  19. Signal anomaly detection and characterization

    International Nuclear Information System (INIS)

    Morgenstern, V.M.; Upadhyaya, B.R.; Gloeckler, O.

    1988-08-01

    As part of a comprehensive signal validation system, we have developed a signal anomaly detector, without specifically establishing the cause of the anomaly. A signal recorded from process instrumentation is said to have an anomaly, if during steady-state operation, the deviation in the level of the signal, its root-mean-square (RMS) value, or its statistical distribution changes by a preset value. This deviation could be an unacceptable increase or a decrease in the quantity being monitored. An anomaly in a signal may be characterized by wideband or single-frequency noise, bias error, pulse-type error, nonsymmetric behavior, or a change in the signal bandwidth. Various signatures can be easily computed from data samples and compared against specified threshold values. We want to point out that in real processes, pulses can appear with different time widths, and at different rates of change of the signal. Thus, in characterizing an anomaly as a pulse-type, the fastest pulse width is constrained by the signal sampling interval. For example, if a signal is sampled at 100 Hz, we will not be able to detect pulses occurring at kHz rates. Discussion with utility and Combustion Engineering personnel indicated that it is not practical to detect pulses having a narrow time width. 9 refs., 11 figs., 8 tabs

  20. Radiologic analysis of congenital limb anomalies

    International Nuclear Information System (INIS)

    Chung, Hong Jun; Kim, Ok Hwa; Shinn, Kyung Sub; Kim, Nam Ae

    1994-01-01

    Congenital limb anomalies are manifested in various degree of severity and complexity bearing conclusion for description and nomenclature of each anomaly. We retrospectively analyzed the roentgenograms of congenital limb anomalies for the purpose of further understanding of the radiologic manifestations based on the embryonal defect and also to find the incidence of each anomaly. Total number of the patients was 89 with 137 anomalies. Recently the uniform system of classification for congenital anomalies of the upper limb was adopted by International Federation of Societies for Surgery of the Hand (IFSSH), which were categorized as 7 classifications. We used the IFSSH classification with some modification as 5 classifications; failure of formation of parts, failure of differentiation of parts, duplications, overgrowth and undergrowth. The patients with upper limb anomalies were 65 out of 89(73%), lower limb were 21(24%), and both upper and lower limb anomalies were 3(4%). Failure of formation was seen in 18%, failure of differentiation 39%, duplications 39%, overgrowth 8%, and undergrowth in 12%. Thirty-five patients had more than one anomaly, and 14 patients had intergroup anomalies. The upper limb anomalies were more common than lower limb. Among the anomalies, failure of differentiation and duplications were the most common types of congenital limb anomalies. Patients with failure of formation, failure of differentiation, and undergrowth had intergroup association of anomalies, but duplication and overgrowth tended to be isolated anomalies

  1. String corrections to circular Wilson loop and anomalies

    Science.gov (United States)

    Cagnazzo, Alessandra; Medina-Rincon, Daniel; Zarembo, Konstantin

    2018-02-01

    We study string quantum corrections to the ratio of latitude and circular Wilson loops in N = 4 super-Yang-Mills theory at strong coupling. Conformal gauge for the corresponding minimal surface in AdS5 × S 5 is singular and we show that an IR anomaly associated with the divergence in the conformal factor removes previously reported discrepancy with the exact field-theory result. We also carefully check conformal anomaly cancellation and recalculate fluctuation determinants by directly evaluting phaseshifts for all the fluctuation modes.

  2. WFC3 IR subarray anomaly

    Science.gov (United States)

    Bushouse, Howard

    2009-07-01

    Certain combinations of WFC3 IR subarray size and sample sequence yield images that show a sharp change in background level that exactly bi-sects each detector amplifier quadrant. The change in level has an amplitude of a few DN per pixel. The cause of this anomaly and its apparent correlation with subarray size and sample sequence is not understood. Given the 4 available subarray sizes and 11 available readout sample sequences, there are a total of 44 possible subarray mode readout combinations. To date, 14 of those combinations have been used on-orbit in either calibration and GO programs. Of those, 3 combinations show the anomaly. This program will obtain IR dark exposures in the remaining 30 readout combinations that have not yet been explored. This will add to our knowledge of which combinations show the anomaly and will therefore help us to understand its origin.

  3. Graph anomalies in cyber communications

    Energy Technology Data Exchange (ETDEWEB)

    Vander Wiel, Scott A [Los Alamos National Laboratory; Storlie, Curtis B [Los Alamos National Laboratory; Sandine, Gary [Los Alamos National Laboratory; Hagberg, Aric A [Los Alamos National Laboratory; Fisk, Michael [Los Alamos National Laboratory

    2011-01-11

    Enterprises monitor cyber traffic for viruses, intruders and stolen information. Detection methods look for known signatures of malicious traffic or search for anomalies with respect to a nominal reference model. Traditional anomaly detection focuses on aggregate traffic at central nodes or on user-level monitoring. More recently, however, traffic is being viewed more holistically as a dynamic communication graph. Attention to the graph nature of the traffic has expanded the types of anomalies that are being sought. We give an overview of several cyber data streams collected at Los Alamos National Laboratory and discuss current work in modeling the graph dynamics of traffic over the network. We consider global properties and local properties within the communication graph. A method for monitoring relative entropy on multiple correlated properties is discussed in detail.

  4. Multiple Visceral and Peritoneal Anomalies

    Directory of Open Access Journals (Sweden)

    Gayathri Prabhu S

    2016-07-01

    Full Text Available Visceral and peritoneal anomalies are frequently encountered during cadaveric dissections and surgical procedures of abdomen. A thorough knowledge of the same is required for the success of diagnostic, surgical and radiological procedures of abdomen. We report multiple peritoneal and visceral anomalies noted during dissection classes for medical undergraduates. The anomalies were found in an adult male cadaver aged approximately 70 years. The right iliac fossa was empty due to the sub-hepatic position of caecum and appendix. The sigmoid colon formed an inverted “U” shaped loop above the sacral promontory in the median position. It entered the pelvis from the right side and descended along the lateral wall of the pelvis. The sigmoid mesocolon was attached obliquely to the posterior abdominal wall, just above the sacral promontory. Further there was a cysto-colic fold of peritoneum extending from the right colic flexure. We discuss the clinical significance of the variations.

  5. Review on possible gravitational anomalies

    International Nuclear Information System (INIS)

    Amador, Xavier E

    2005-01-01

    This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15)

  6. Sequential auctions and price anomalies

    Directory of Open Access Journals (Sweden)

    Trifunović Dejan

    2014-01-01

    Full Text Available In sequential auctions objects are sold one by one in separate auctions. These sequential auctions might be organized as sequential first-price, second-price, or English auctions. We will derive equilibrium bidding strategies for these auctions. Theoretical models suggest that prices in sequential auctions with private values or with randomly assigned heterogeneous objects should have no trend. However, empirical research contradicts this result and prices exhibit a declining or increasing trend, which is called declining and increasing price anomaly. We will present a review of these empirical results, as well as different theoretical explanations for these anomalies.

  7. arXiv Anomaly-Free Models for Flavour Anomalies

    CERN Document Server

    Ellis, John; Tunney, Patrick

    We explore the constraints imposed by the cancellation of triangle anomalies on models in which the flavour anomalies reported by LHCb and other experiments are due to an extra U(1)' gauge boson Z'. We assume universal and rational U(1)' charges for the first two generations of left-handed quarks and of right-handed up-type quarks but allow different charges for their third-generation counterparts. If the right-handed charges vanish, cancellation of the triangle anomalies requires all the quark U(1)' charges to vanish, if there are either no exotic fermions or there is only one Standard Model singlet dark matter (DM) fermion. There are non-trivial anomaly-free models with more than one such `dark' fermion, or with a single DM fermion if right-handed up-type quarks have non-zero U(1)' charges. In some of the latter models the U(1)' couplings of the first- and second-generation quarks all vanish, weakening the LHC Z' constraint, and in some other models the DM particle has purely axial couplings, weakening the ...

  8. Anomaly Detection in Gas Turbine Fuel Systems Using a Sequential Symbolic Method

    Directory of Open Access Journals (Sweden)

    Fei Li

    2017-05-01

    Full Text Available Anomaly detection plays a significant role in helping gas turbines run reliably and economically. Considering the collective anomalous data and both sensitivity and robustness of the anomaly detection model, a sequential symbolic anomaly detection method is proposed and applied to the gas turbine fuel system. A structural Finite State Machine is used to evaluate posterior probabilities of observing symbolic sequences and the most probable state sequences they may locate. Hence an estimation-based model and a decoding-based model are used to identify anomalies in two different ways. Experimental results indicate that both models have both ideal performance overall, but the estimation-based model has a strong robustness ability, whereas the decoding-based model has a strong accuracy ability, particularly in a certain range of sequence lengths. Therefore, the proposed method can facilitate well existing symbolic dynamic analysis- based anomaly detection methods, especially in the gas turbine domain.

  9. Ferromagnetic Spin Coupling as the Origin of 0.7 Anomaly in Quantum Point Contacts

    OpenAIRE

    Aryanpour, K.; Han, J. E.

    2008-01-01

    We study one-dimensional itinerant electron models with ferromagnetic coupling to investigate the origin of 0.7 anomaly in quantum point contacts. Linear conductance calculations from the quantum Monte Carlo technique for spin interactions of different spatial range suggest that $0.7(2e^{2}/h)$ anomaly results from a strong interaction of low-density conduction electrons to ferromagnetic fluctuations formed across the potential barrier. The conductance plateau appears due to the strong incohe...

  10. Theory of hyperfine anomalies in muonic atoms

    International Nuclear Information System (INIS)

    Freeman, A.J.; Desclaux, J.P.

    1984-01-01

    Negative muon spin precession experiments have found giant hyperfine anomalies in muonic atoms ranging from a few percent up to 36%. In order to understand these results, the authors present Breit interaction calculations based on atomic self-consistent unrestricted Dirac-Fock solutions which explicitly include all electrons and the negative muon. The Breit interaction results (including the relativistic correction for the bound muon g-factor), vary from near zero for μ - O/N to -5% for μ - Pd/Rh; this latter is much larger than the calculated muonic or nuclear Bohr-Weisskopf anomalies and much smaller than the 36% measured value. For μ - Ni/Co the authors find a calculated range of results (depending on assumed electronic configurations) of -2.3 to -2.7% in excellent agreement with recent measurements. This excellent agreement in μ - Ni/Co provides strong support for the earlier suggestions that the discrepancy in the case of μ - Pd/Rh is due to experimental factors. (Auth.)

  11. The prevalence of congenital anomalies in Europe

    DEFF Research Database (Denmark)

    Dolk, Helen; Loane, Maria; Garne, Ester

    2010-01-01

    EUROCAT (European Surveillance of Congenital Anomalies) is the network of population-based registers of congenital anomaly in Europe, with a common protocol and data quality review, covering 1.5 million annual births in 22 countries. EUROCAT recorded a total prevalence of major congenital anomalies...... anomalies overwhelmingly concern children surviving the early neonatal period, who have important medical, social or educational needs. The prevalence of chromosomal anomalies was 3.6 per 1,000 births, contributing 28% of stillbirths/fetal deaths from 20 weeks gestation with congenital anomaly, and 48...

  12. Anomaly detection in diurnal data

    NARCIS (Netherlands)

    Mata, F.; Zuraniewski, P.W.; Mandjes, M.; Mellia, M.

    2014-01-01

    In this paper we present methodological advances in anomaly detection tailored to discover abnormal traffic patterns under the presence of seasonal trends in data. In our setup we impose specific assumptions on the traffic type and nature; our study features VoIP call counts, for which several

  13. Descendants of the Chiral Anomaly

    OpenAIRE

    Jackiw, R.

    2000-01-01

    Chern-Simons terms are well-known descendants of chiral anomalies, when the latter are presented as total derivatives. Here I explain that also Chern-Simons terms, when defined on a 3-manifold, may be expressed as total derivatives.

  14. Neutrino anomaly and -nucleus interactions

    Indian Academy of Sciences (India)

    The neutrino anomaly generally refers to the solar neutrino problem where the observed number of electron type neutrinos from the sun was found to be considerably smaller than the number predicted in standard model of particle interactions [1–2]. Similar depletion of muon type neutrinos is found in the flux of atmospheric ...

  15. Gaugino-assisted anomaly mediation

    International Nuclear Information System (INIS)

    Kribs, Graham D.

    2001-01-01

    I present a model of supersymmetry breaking mediated through a small extra dimension. Standard model matter multiplets and a supersymmetry-breaking (or 'hidden') sector are confined to opposite four-dimensional boundaries while gauge multiplets live in the bulk. The hidden sector does not contain a singlet and the dominant contribution to gaugino masses is via anomaly-mediated supersymmetry breaking. Scalar masses get contributions from both anomaly mediation and a tiny hard breaking of supersymmetry by operators on the hidden-sector boundary. These operators contribute to scalar masses at one loop and in most of parameter space, their contribution dominates. Thus it is easy to make all squared scalar masses positive. As no additional fields or symmetries are required below the Planck scale, this is among the simplest working models of anomaly mediation. The gaugino spectrum is left untouched and the phenomenology of the model is roughly similar to anomaly mediated supersymmetry breaking with a universal scalar mass added. Finally, the main differences in the spectrum between this model and other approaches are identified. This talk is based on work [1] done in collaboration with David E. Kaplan

  16. Algebraic study of chiral anomalies

    Indian Academy of Sciences (India)

    2012-06-14

    Jun 14, 2012 ... Abstract. The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles ... Editor's Note: †Reproduced with kind permission from Springer Science+Business Media: Algebraic study of chiral anoma- ..... We shall see in the sequel several examples in which this ambiguity helps.

  17. Kohn Anomaly and Phase Stability in Group VB Transition Metals

    Directory of Open Access Journals (Sweden)

    Alexander Landa

    2018-03-01

    Full Text Available In the periodic table, only a few pure metals exhibit lattice or magnetic instabilities associated with Fermi surface nesting, the classical examples being α-U and Cr. Whereas α-U displays a strong Kohn anomaly in the phonon spectrum that ultimately leads to the formation of charge density waves (CDWs, Cr is known for its nesting-induced spin density waves (SDWs. Recently, it has become clear that a pronounced Kohn anomaly and the corresponding softening in the elastic constants is also the key factor that controls structural transformations and mechanical properties in compressed group VB metals—materials with relatively high superconducting critical temperatures. This article reviews the current understanding of the structural and mechanical behavior of these metals under pressure with an introduction to the concept of the Kohn anomaly and how it is related to the important concept of Peierls instability. We review both experimental and theoretical results showing different manifestations of the Kohn anomaly in the transverse acoustic phonon mode TA (ξ00 in V, Nb, and Ta. Specifically, in V the anomaly triggers a structural transition to a rhombohedral phase, whereas in Nb and Ta it leads to an anomalous reduction in yield strength.

  18. Observation of an impact-parameter window in low-velocity ionizing collisions of Ne+ on Ne proceeding through quasimolecular states

    International Nuclear Information System (INIS)

    Abdallah, M.A.; Cocke, C.L.; Stoeckli, M.; Wolff, W.; Wolf, H.E.

    1998-01-01

    Target ionization in collisions of singly charged Ne + ions with Ne has been investigated at projectile velocities from 0.25 to 0.55 a.u. using electron and recoil momentum imaging techniques. The momentum distributions of the ejected electrons were found to carry a distinct signature strongly suggesting that ionization is taking place by successive promotions through molecular orbitals. The observed recoil transverse momentum distributions are donut-shaped, indicating that single ionization is confined to a well-defined impact-parameter window. copyright 1998 The American Physical Society

  19. A Generalized Version of a Low Velocity Impact between a Rigid Sphere and a Transversely Isotropic Strain-Hardening Plate Supported by a Rigid Substrate Using the Concept of Noninteger Derivatives

    Directory of Open Access Journals (Sweden)

    Abdon Atangana

    2013-01-01

    Full Text Available A low velocity impact between a rigid sphere and transversely isotropic strain-hardening plate supported by a rigid substrate is generalized to the concept of noninteger derivatives order. A brief history of fractional derivatives order is presented. The fractional derivatives order adopted is in Caputo sense. The new equation is solved via the analytical technique, the Homotopy decomposition method (HDM. The technique is described and the numerical simulations are presented. Since it is very important to accurately predict the contact force and its time history, the three stages of the indentation process, including (1 the elastic indentation, (2 the plastic indentation, and (3 the elastic unloading stages, are investigated.

  20. Mesotron Decays and the Role of Anomalies

    OpenAIRE

    Bardeen, William A.

    2007-01-01

    Puzzles associated with Yukawa's mesotron theory of nuclear interactions led to the discovery of "anomalies" in quantum field theory. I will discuss some of the remarkable consequences of these anomalies in the physics of elementary particles.

  1. Mesozoic anomalies in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.; Nair, R.R.; Sarma, K.V.L.N.S.; Ramprasad, T.; Krishna, K.S.; Subrahmanyam, V.; D'Cruz, M.; Subrahmanyam, C.; Paul, J.; Subrahmanyam, A.S.; Sekhar, D.V.C.

    The analysis of 8200 line km of total magnetic intensity data in the Bay of Bengal, northeastern Indian Ocean, revealed the presence of approximately N30~'E-trending seafloor spreading type magnetic anomalies. These anomalies resemble the Mesozoic...

  2. Needs for reactivity anomaly monitoring in CRBRP

    International Nuclear Information System (INIS)

    Bullock, J.B.

    1975-01-01

    Two general classifications of reactivity anomalies are defined and explicit design criteria and operational philosophy for an anomaly monitoring system for the Clinch River Breeder Reactor are presented. (JWR)

  3. Geophysical Anomalies and Earthquake Prediction

    Science.gov (United States)

    Jackson, D. D.

    2008-12-01

    Finding anomalies is easy. Predicting earthquakes convincingly from such anomalies is far from easy. Why? Why have so many beautiful geophysical abnormalities not led to successful prediction strategies? What is earthquake prediction? By my definition it is convincing information that an earthquake of specified size is temporarily much more likely than usual in a specific region for a specified time interval. We know a lot about normal earthquake behavior, including locations where earthquake rates are higher than elsewhere, with estimable rates and size distributions. We know that earthquakes have power law size distributions over large areas, that they cluster in time and space, and that aftershocks follow with power-law dependence on time. These relationships justify prudent protective measures and scientific investigation. Earthquake prediction would justify exceptional temporary measures well beyond those normal prudent actions. Convincing earthquake prediction would result from methods that have demonstrated many successes with few false alarms. Predicting earthquakes convincingly is difficult for several profound reasons. First, earthquakes start in tiny volumes at inaccessible depth. The power law size dependence means that tiny unobservable ones are frequent almost everywhere and occasionally grow to larger size. Thus prediction of important earthquakes is not about nucleation, but about identifying the conditions for growth. Second, earthquakes are complex. They derive their energy from stress, which is perniciously hard to estimate or model because it is nearly singular at the margins of cracks and faults. Physical properties vary from place to place, so the preparatory processes certainly vary as well. Thus establishing the needed track record for validation is very difficult, especially for large events with immense interval times in any one location. Third, the anomalies are generally complex as well. Electromagnetic anomalies in particular require

  4. Limb body wall complex: A rare anomaly

    Directory of Open Access Journals (Sweden)

    Panduranga Chikkannaiah

    2013-01-01

    Full Text Available We present autopsy findings of a case of limb body wall complex (LBWC. The fetus had encephalocele, genitourinary agenesis, skeletal anomalies and body wall defects. The rare finding in our case is the occurrence of both cranial and urogenital anomalies. The presence of complex anomalies in this fetus, supports embryonal dysplasia theory of pathogenesis for LBWC.

  5. Fetal renal anomalies : diagnosis, management, and outcome

    NARCIS (Netherlands)

    Damen-Elias, Henrica Antonia Maria

    2004-01-01

    In two to three percent of fetuses structural anomalies can be found with prenatal ultrasound investigation. Anomalies of the urinary tract account for 15 to 20% of these anomalies with a detection rate of approximately of 90%. In Chapter 2, 3 and 4 we present reference curves for size and growth

  6. Holographic entanglement entropy and gravitational anomalies

    NARCIS (Netherlands)

    Castro, A.; Detournay, S.; Iqbal, N.; Perlmutter, E.

    2014-01-01

    We study entanglement entropy in two-dimensional conformal field theories with a gravitational anomaly. In theories with gravity duals, this anomaly is holographically represented by a gravitational Chern-Simons term in the bulk action. We show that the anomaly broadens the Ryu-Takayanagi minimal

  7. Modeling 3-D density distribution in the upper mantle beneath the Yellowstone from inversion of geoid anomaly data

    Science.gov (United States)

    Moreno Chaves, C. M.; Ussami, N.

    2011-12-01

    We developed a simple three-dimensional scheme to invert geoid anomalies, aiming to map density variations in the lower crust and the upper mantle. Using a flat-Earth approximation, the model space is represented by a finite set of rectangular prisms. The linear inversion algorithm is based on Tikhonov regularization and the convergence of the solution is controlled by the Levenberg-Marquardt method. Our linear inversion algorithm does not require an initial density model, allowing it to be used where geological constraints on density are not available. To analyze the quality of the model density obtained by the inversion algorithm, we used the resolution and the covariance matrices. In order to study the thermal and the composition state beneath the Yellowstone and to test our algorithm inversion, geoid anomalies were inverted and modeled. Yellowstone exhibits a high geoid anomaly (~13 m), with a topographic swell of about 500 km wide. Residual geoid anomalies were obtained using the EGM2008 [Pavlis et al., 2008] geopotential model expanded up to degree 2160 after removing the long-wavelength component (degree 10). Lower crust and mantle-related geoid anomalies with -80 m amplitude were obtained after removing crustal effects (topographic masses, sediments and crustal thickness variations). The center of the negative geoid anomaly coincides geographically with the low velocity body (Yuan and Dueker [2005] and Waite et al. [2006]) in the upper mantle and with a depression of 12 km of the 410 km discontinuity detected by Fee and Dueker [2004]. Our results show that the lower crust and the upper mantle of the Yellowstone have a predominantly negative density contrast (-10 to -75 kg/m3) relative to the surrounding mantle. The mass deficiency mapped beneath the Yellowstone suggests the mantle to be hotter (-200 to -300 °C) and buoyant to isostatically sustain the high topography of this province (> 3000 m above sea level). The density model shows that the negative

  8. Holomorphic anomaly and quantum mechanics

    Science.gov (United States)

    Codesido, Santiago; Mariño, Marcos

    2018-02-01

    We show that the all-orders WKB periods of one-dimensional quantum mechanical oscillators are governed by the refined holomorphic anomaly equations of topological string theory. We analyze in detail the double-well potential and the cubic and quartic oscillators, and we calculate the WKB expansion of their quantum free energies by using the direct integration of the anomaly equations. We reproduce in this way all known results about the quantum periods of these models, which we express in terms of modular forms on the WKB curve. As an application of our results, we study the large order behavior of the WKB expansion in the case of the double well, which displays the double factorial growth typical of string theory.

  9. Parity anomaly in four dimensions

    Science.gov (United States)

    Kurkov, M.; Vassilevich, D.

    2017-07-01

    In an analogy to the odd-dimensional case we define the parity anomaly as the part of the one-loop effective action for fermions associated with spectral asymmetry of the Dirac operator. This quantity is computed directly on four-dimensional manifolds with a boundary and related to the Chern-Simons current on the boundary. Despite a quite unusual Chern-Simons level obtained, the action is gauge invariant and passes all consistency checks.

  10. Anomaly mediation in superstring theory

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, Joseph P. [Rudolf Peierls Center for Theoretical Physics, Oxford (United Kingdom); Balliol College, Oxford (United Kingdom); Goodsell, Mark [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Palti, Eran [Centre de Physique Theoretique, Ecole Polytechnique, CNRS, Palaiseau (France)

    2010-08-15

    We study anomaly mediated supersymmetry breaking in type IIB string theory and use our results to test the supergravity formula for anomaly mediated gaugino masses. We compute 1-loop gaugino masses for models of D3-branes on orbifold singularities with 3-form fluxes by calculating the annulus correlator of 3-form flux and two gauginos in the zero momentum limit. Consistent with supergravity expectations we find both anomalous and running contributions to 1-loop gaugino masses. For background Neveu-Schwarz H-flux we find an exact match with the supergravity formula. For Ramond-Ramond flux there is an off-shell ambiguity that precludes a full matching. The anomaly mediated gaugino masses, while determined by the infrared spectrum, arise from an explicit sum over UV open string winding modes. We also calculate brane-to-brane tree-level gravity mediated gaugino masses and show that there are two contributions coming from the dilaton and from the twisted modes, which are suppressed by the full T{sup 6} volume and the untwisted T{sup 2} volume respectively. (orig.)

  11. Conjecture on the physical implications of the scale anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Christopher T.; /Fermilab

    2005-10-01

    Murray Gell-Mann, after co-inventing QCD, recognized the interplay of the scale anomaly, the renormalization group, and the origin of the strong scale, {Lambda}{sub QCD}. I tell a story, then elaborate this concept, and for the sake of discussion, propose a conjecture that the physical world is scale invariant in the classical, {h_bar}, limit. This principle has implications for the dimensionality of space-time, the cosmological constant, the weak scale, and Planck scale.

  12. Conjecture on the physical implications of the scale anomaly

    International Nuclear Information System (INIS)

    Hill, Christopher T.; Fermilab

    2005-01-01

    Murray Gell-Mann, after co-inventing QCD, recognized the interplay of the scale anomaly, the renormalization group, and the origin of the strong scale, Λ QCD . I tell a story, then elaborate this concept, and for the sake of discussion, propose a conjecture that the physical world is scale invariant in the classical, ℎ → 0, limit. This principle has implications for the dimensionality of space-time, the cosmological constant, the weak scale, and Planck scale

  13. Algorithms for Anomaly Detection - Lecture 1

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The concept of statistical anomalies, or outliers, has fascinated experimentalists since the earliest attempts to interpret data. We want to know why some data points don’t seem to belong with the others: perhaps we want to eliminate spurious or unrepresentative data from our model. Or, the anomalies themselves may be what we are interested in: an outlier could represent the symptom of a disease, an attack on a computer network, a scientific discovery, or even an unfaithful partner. We start with some general considerations, such as the relationship between clustering and anomaly detection, the choice between supervised and unsupervised methods, and the difference between global and local anomalies. Then we will survey the most representative anomaly detection algorithms, highlighting what kind of data each approach is best suited to, and discussing their limitations. We will finish with a discussion of the difficulties of anomaly detection in high-dimensional data and some new directions for anomaly detec...

  14. Algorithms for Anomaly Detection - Lecture 2

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The concept of statistical anomalies, or outliers, has fascinated experimentalists since the earliest attempts to interpret data. We want to know why some data points don’t seem to belong with the others: perhaps we want to eliminate spurious or unrepresentative data from our model. Or, the anomalies themselves may be what we are interested in: an outlier could represent the symptom of a disease, an attack on a computer network, a scientific discovery, or even an unfaithful partner. We start with some general considerations, such as the relationship between clustering and anomaly detection, the choice between supervised and unsupervised methods, and the difference between global and local anomalies. Then we will survey the most representative anomaly detection algorithms, highlighting what kind of data each approach is best suited to, and discussing their limitations. We will finish with a discussion of the difficulties of anomaly detection in high-dimensional data and some new directions for anomaly detec...

  15. Coronary anomalies: what the radiologist should know

    Directory of Open Access Journals (Sweden)

    Priscilla Ornellas Neves

    2015-08-01

    Full Text Available AbstractCoronary anomalies comprise a diverse group of malformations, some of them asymptomatic with a benign course, and the others related to symptoms as chest pain and sudden death. Such anomalies may be classified as follows: 1 anomalies of origination and course; 2 anomalies of intrinsic coronary arterial anatomy; 3 anomalies of coronary termination. The origin and the proximal course of anomalous coronary arteries are the main prognostic factors, and interarterial course or a coronary artery is considered to be malignant due its association with increased risk of sudden death. Coronary computed tomography angiography has become the reference method for such an assessment as it detects not only anomalies in origination of these arteries, but also its course in relation to other mediastinal structures, which plays a relevant role in the definition of the therapeutic management. Finally, it is essential for radiologists to recognize and characterize such anomalies.

  16. Seasonality of congenital anomalies in Europe

    DEFF Research Database (Denmark)

    Luteijn, Johannes Michiel; Dolk, Helen; Addor, Marie-Claude

    2014-01-01

    seasonality of 65,764 nonchromosomal and 12,682 chromosomal congenital anomalies covering 3.3 million births. Analysis was performed by estimated month of conception. Analyses were performed for 86 congenital anomaly subgroups, including a combined subgroup of congenital anomalies previously associated......%), congenital hydronephrosis (July, 12%), urinary defects (July, 5%), and situs inversus (December, 36%), but not for nonchromosomal anomalies combined, chromosomal anomalies combined, or other anomalies analyzed. CONCLUSION: We have confirmed previously described seasonality for congenital cataract and hip......BACKGROUND: This study describes seasonality of congenital anomalies in Europe to provide a baseline against which to assess the impact of specific time varying exposures such as the H1N1 pandemic influenza, and to provide a comprehensive and recent picture of seasonality and its possible relation...

  17. Major congenital anomalies in a Danish region

    DEFF Research Database (Denmark)

    Garne, Ester; Hansen, Anne Vinkel; Birkelund, Anne Sofie

    2014-01-01

    congenital anomaly, 13.9% had a chromosomal anomaly and 7.7% were multiple congenital anomalies. The combined foetal and infant mortality in the study area was 11.6 per 1,000 births. 19% (2.2 per 1,000) of these deaths were foetuses and infants with major congenital anomalies. Combined foetal and infant......INTRODUCTION: This study describes the prevalence of congenital anomalies and changes over time in birth outcome, mortality and chronic maternal diseases. MATERIAL AND METHODS: This study was based on population data from the EUROCAT registry covering the Funen County, Denmark, 1995......-2008. The registry covers live births, foetal deaths with a gestational age (GA) of 20 weeks or more, and terminations of pregnancy due to congenital anomalies (TOPFA). RESULTS: The overall prevalence of congenital anomalies was 2.70% (95% confidence interval: 2.58-2.80). The majority of cases had an isolated...

  18. Coronary anomalies: what the radiologist should know*

    Science.gov (United States)

    Neves, Priscilla Ornellas; Andrade, Joalbo; Monção, Henry

    2015-01-01

    Coronary anomalies comprise a diverse group of malformations, some of them asymptomatic with a benign course, and the others related to symptoms as chest pain and sudden death. Such anomalies may be classified as follows: 1) anomalies of origination and course; 2) anomalies of intrinsic coronary arterial anatomy; 3) anomalies of coronary termination. The origin and the proximal course of anomalous coronary arteries are the main prognostic factors, and interarterial course or a coronary artery is considered to be malignant due its association with increased risk of sudden death. Coronary computed tomography angiography has become the reference method for such an assessment as it detects not only anomalies in origination of these arteries, but also its course in relation to other mediastinal structures, which plays a relevant role in the definition of the therapeutic management. Finally, it is essential for radiologists to recognize and characterize such anomalies. PMID:26379322

  19. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  20. Response of African humid tropical forests to recent rainfall anomalies.

    Science.gov (United States)

    Asefi-Najafabady, Salvi; Saatchi, Sassan

    2013-01-01

    During the last decade, strong negative rainfall anomalies resulting from increased sea surface temperature in the tropical Atlantic have caused extensive droughts in rainforests of western Amazonia, exerting persistent effects on the forest canopy. In contrast, there have been no significant impacts on rainforests of West and Central Africa during the same period, despite large-scale droughts and rainfall anomalies during the same period. Using a combination of rainfall observations from meteorological stations from the Climate Research Unit (CRU; 1950-2009) and satellite observations of the Tropical Rainfall Measuring Mission (TRMM; 1998-2010), we show that West and Central Africa experienced strong negative water deficit (WD) anomalies over the last decade, particularly in 2005, 2006 and 2007. These anomalies were a continuation of an increasing drying trend in the region that started in the 1970s. We monitored the response of forests to extreme rainfall anomalies of the past decade by analysing the microwave scatterometer data from QuickSCAT (1999-2009) sensitive to variations in canopy water content and structure. Unlike in Amazonia, we found no significant impacts of extreme WD events on forests of Central Africa, suggesting potential adaptability of these forests to short-term severe droughts. Only forests near the savanna boundary in West Africa and in fragmented landscapes of the northern Congo Basin responded to extreme droughts with widespread canopy disturbance that lasted only during the period of WD. Time-series analyses of CRU and TRMM data show most regions in Central and West Africa experience seasonal or decadal extreme WDs (less than -600 mm). We hypothesize that the long-term historical extreme WDs with gradual drying trends in the 1970s have increased the adaptability of humid tropical forests in Africa to droughts.

  1. Analogue forecasting of New Zealand climate anomalies

    Science.gov (United States)

    Mullan, A. Brett; Thompson, Craig S.

    2006-03-01

    An analogue forecast scheme is described for multifield prediction of monthly and seasonal New Zealand climate anomalies on the basis of the methodology of Livezey and Barnston ([1988]) for US seasonal temperatures. The method is applied to predicting terciles of temperature and precipitation for six regions of New Zealand. Empirical orthogonal function analysis is used to reduce sea surface temperature and sea-level pressure predictors down to a set of five independent indices, which incorporate variations due to El Niño-Southern Oscillation, Indian Ocean sea temperatures and a wave 3 pattern in the Southern Hemisphere westerlies. A full bootstrap cross-validation procedure is carried out, along with Monte Carlo tests, to assess the skill of the method on independent data and to determine the significance of the results. Significant skill is found for seasonal temperature forecasts for the summer and winter seasons; there is less success in predicting monthly temperatures or rainfall at either timescale. Considerable care is required to constrain the climate state vector, from which analogues are defined, and to constrain the search procedure itself, in order to produce results that are stable with respect to small parameter changes in the model. For the New Zealand region, 5 to 7 is found to be the optimum number of closest analogues, and the inclusion of anti-analogues improves the predictions, at least in the seasonal case. Skill in predicting regional temperature and rainfall is shown to be related to a combination of skill in predicting sea-level pressure patterns and to how strongly these patterns project onto temperature and rainfall anomalies.

  2. Magnetic Anomaly Amplitudes on the Gakkel Ridge: Indicators of Ridge Variability

    Science.gov (United States)

    Childers, V. A.; Lawver, L. A.; Brozena, J. M.

    2002-12-01

    For most of its length, the Gakkel Ridge in the Arctic Ocean's Eurasia Basin is characterized by a discontinuous magnetic signature with regions of missing or low-amplitude central anomalies punctuated by short, high-amplitude segments. The ridge segment in between the Morris Jesup Rise and the Yermak Plateau has an unusually large amplitude central magnetic anomaly that is more than four times the amplitude of the flanking anomalies. This ridge segment is straight, without large offsets, for about 150 km. The difference in character between the central anomaly in this segment and the rest of Gakkel Ridge is striking. The western half of the Gakkel Ridge and the Eurasia Basin were surveyed in 1998-99 by a Naval Research Laboratory aerogeophysical campaign that measured magnetics, gravity, and sea-surface topography. The new magnetic data densify the historical US Navy aeromagnetic data and improve the resolution of the magnetic anomaly field in this region. This new field highlights the variability of the Gakkel Ridge over time, showing regions of strong anomalies that are continuous along strike and anomalies that fade away or become discontinuous. In particular, anomalies 15y to 21o show regions of high amplitudes on both sides of the ridge for varying distances along strike. We suggest that these high-amplitude segments were formed at times when the Gakkel Ridge at this location had a high-amplitude central magnetic anomaly like the present day high-amplitude segment or the shorter ones distributed along the ridge. The higher central anomaly amplitudes may be associated with variations in geochemistry and/or melt delivery along the ridge. Recent dredging of zero-aged crust along the Gakkel Ridge showed a good but not perfect correlation of high-amplitude central anomalies and basalt recovery (P. Michael, personal communication). This magnetic data set in conjunction with future dredging provides an opportunity to constrain past ridge variability.

  3. Congenital anomalies in Primorsky region.

    Science.gov (United States)

    Kiku, P; Voronin, S; Golokhvast, K

    2015-01-01

    According to WHO hereditary diseases and congenital malformations contribute significantly to the health of population. Thus, the problems of epidemiology, clinical presentation, diagnosis and treatment of congenital abnormalities are of interest for many researchers [2]. In addition, the dynamic accounting for the incidence of congenital malformations and hereditary diseases allows the researchers to assess the ecological situation in the region [1]. The occurrence of congenital anomalies in the world varies; it depends heavily on how carefully the data is collected [4]. Multifactorial or polygenic diseases develop under the influence of environmental factors in the presence of defective genes. They can constitute up to 90% of all chronic pathology [2-5]. To determine the incidence of congenital anomalies under the influence of environmental factors. The study used the methodology of system evaluation of congenital anomalies incidence in Primorsky region, depending on bio-climatic and environmental conditions. The authors used health statistics for the period from 2000 to 2014, F.12 class for congenital abnormalities in adolescents and children that were compared in geographical and temporal aspects with environmental factors of 33 settlements in Primorsky region. The environment is represented by nature and climate (6 factor modules) and sanitation (7 factor modules) blocks of factors. When formalizing the information database of the environment a specially developed 10-point assessment scale was used. Statistical processing of the information was carried out using Pearson's chi-squared test and multiple regression method from SSPS application program package. The study found that over the 15-year period the level of congenital abnormalities in children increased by 27.5% and in adolescents - by 35.1%, and in 2014 it amounted to 1687.6 and 839.3 per 100 000 people, respectively. The predictive model shows a steady further growth of this pathology. The incidence

  4. ISHM Anomaly Lexicon for Rocket Test

    Science.gov (United States)

    Schmalzel, John L.; Buchanan, Aubri; Hensarling, Paula L.; Morris, Jonathan; Turowski, Mark; Figueroa, Jorge F.

    2007-01-01

    Integrated Systems Health Management (ISHM) is a comprehensive capability. An ISHM system must detect anomalies, identify causes of such anomalies, predict future anomalies, help identify consequences of anomalies for example, suggested mitigation steps. The system should also provide users with appropriate navigation tools to facilitate the flow of information into and out of the ISHM system. Central to the ability of the ISHM to detect anomalies is a clearly defined catalog of anomalies. Further, this lexicon of anomalies must be organized in ways that make it accessible to a suite of tools used to manage the data, information and knowledge (DIaK) associated with a system. In particular, it is critical to ensure that there is optimal mapping between target anomalies and the algorithms associated with their detection. During the early development of our ISHM architecture and approach, it became clear that a lexicon of anomalies would be important to the development of critical anomaly detection algorithms. In our work in the rocket engine test environment at John C. Stennis Space Center, we have access to a repository of discrepancy reports (DRs) that are generated in response to squawks identified during post-test data analysis. The DR is the tool used to document anomalies and the methods used to resolve the issue. These DRs have been generated for many different tests and for all test stands. The result is that they represent a comprehensive summary of the anomalies associated with rocket engine testing. Fig. 1 illustrates some of the data that can be extracted from a DR. Such information includes affected transducer channels, narrative description of the observed anomaly, and the steps used to correct the problem. The primary goal of the anomaly lexicon development efforts we have undertaken is to create a lexicon that could be used in support of an associated health assessment database system (HADS) co-development effort. There are a number of significant

  5. Infective causes of congenital anomalies

    OpenAIRE

    Garcia, Aparecida Gomes Pinto

    1981-01-01

    Revisão sumária das causas infecciosas das anomalias congênitas englobando as malformações, que correspondem a estruturas anormais orgânicas ou tissulares decorrentes de erros primários de morfogenese embrionaria e deformações, que se instalam no período fetal da vida intrauterina, correspondentes a alterações de forma e estrutura de órgãos primitivamente bem constituidos.Review of the infective causes of Congenital Anomalies, including Malformations, which arise during the embryonic period a...

  6. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jung-Kyu; Cho, Jeong-Yeon; Choi, Jong-Sun [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2003-12-15

    Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies, lsolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in counseling parents about the postnatal effects of numerous possible associated anomalies. We have encountered 50 cases involving focal musculoskeletal anomalies, including total limb dysplasia [radial ray abnormality (n=3), mesomelic dysplasia (n=1)]; anomalies of the hand [polydactyly (n=8), syndactyly (n=3), ectrodactyly (n=1), clinodactyly (n=6), clenched hand (n=5)]; anomalies of the foot [clubfoot (n=10), rockerbottom foot (n=5), sandal gap deformity (n=1), curly toe (n=2)]; amniotic band syndrome (n=3); and anomalies of the focal spine [block vertebra (n=1), hemivertebra (n=1)]. Among these 50 cases, five [polydactyly (n=1), syndactyly (n=2) and curly toe (n=2) were confirmed by postnatal physical evaluation, two (focal spine anomalies) were diagnosed after postnatal radiologic examination, and the remaining 43 were proven at autopsy. For each condition, we describe the prenatal sonographic findings, and include a brief review.

  7. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    International Nuclear Information System (INIS)

    Ryu, Jung-Kyu; Cho, Jeong-Yeon; Choi, Jong-Sun

    2003-01-01

    Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies, lsolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in counseling parents about the postnatal effects of numerous possible associated anomalies. We have encountered 50 cases involving focal musculoskeletal anomalies, including total limb dysplasia [radial ray abnormality (n=3), mesomelic dysplasia (n=1)]; anomalies of the hand [polydactyly (n=8), syndactyly (n=3), ectrodactyly (n=1), clinodactyly (n=6), clenched hand (n=5)]; anomalies of the foot [clubfoot (n=10), rockerbottom foot (n=5), sandal gap deformity (n=1), curly toe (n=2)]; amniotic band syndrome (n=3); and anomalies of the focal spine [block vertebra (n=1), hemivertebra (n=1)]. Among these 50 cases, five [polydactyly (n=1), syndactyly (n=2) and curly toe (n=2) were confirmed by postnatal physical evaluation, two (focal spine anomalies) were diagnosed after postnatal radiologic examination, and the remaining 43 were proven at autopsy. For each condition, we describe the prenatal sonographic findings, and include a brief review

  8. Altered orientation and flight paths of pigeons reared on gravity anomalies: a GPS tracking study.

    Directory of Open Access Journals (Sweden)

    Nicole Blaser

    Full Text Available The mechanisms of pigeon homing are still not understood, in particular how they determine their position at unfamiliar locations. The "gravity vector" theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However, the gravity vector is tilted by different densities in the earth crust leading to gravity anomalies. We predicted that pigeons reared on different gravity anomalies would show different initial orientation and also show changes in their flight path when crossing a gravity anomaly. We reared one group of pigeons in a strong gravity anomaly with a north-to-south gravity gradient, and the other group of pigeons in a normal area but on a spot with a strong local anomaly with a west-to-east gravity gradient. After training over shorter distances, pigeons were released from a gravitationally and geomagnetically normal site 50 km north in the same direction for both home lofts. As expected by the theory, the two groups of pigeons showed divergent initial orientation. In addition, some of the GPS-tracked pigeons also showed changes in their flight paths when crossing gravity anomalies. We conclude that even small local gravity anomalies at the birth place of pigeons may have the potential to bias the map sense of pigeons, while reactivity to gravity gradients during flight was variable and appeared to depend on individual navigational strategies and frequency of position updates.

  9. Titanium isotopic anomalies in meteorites

    International Nuclear Information System (INIS)

    Niemeyer, S.; Lugmair, G.W.

    1984-01-01

    High-precision analyses of Ti are reported for samples from a variety of meteorite classes. The expanded data base for Allende inclusions still shows Ti isotope anomalies in every inclusion. All the coarse-grained inclusions give quite similar patterns, but fine-grained inclusions show more variable, and sometimes larger, anomalies. One inclusion, 3675A, was analyzed because others identified it as a possible 'FUN' inclusion due to its mass-fractionated Mg. This designation is supported by the significantly more complex Ti isotopic pattern for 3675A compared to all our other Allende inclusions. Available data fail to suggest that any particular Allende mineral phase, including a chromite-carbon fraction from an acid residue, is especially rich in anomalous Ti. We also find anomalous Ti in a bulk sample of a C1 chondrite and in matrix separates from C2 chondrites. The excesses of 50 Ti are smaller than for Allende inclusions, and subtle differences in Ti isotopic patterns tentatively suggest that parent materials for C1-C2 matrix and Allende inclusions are not directly related. Analyses of chondrules from unequilibrated ordinary chondrites did not yield clear evidence for anomalous Ti, but some 'larger than usual' deficits at 50/46 give encouragement for future work in this direction. (author)

  10. A study of dental anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sook; Kim, Jae Duck [Dept. of Oral Radiology, College of Dentistry, Chosun University, Kwangju (Korea, Republic of)

    1993-08-15

    The purpose of this study was to find out the prevalence of dental anomalies in 600 normal persons (male:363, female:237) at age 14 to 39 years, through history taking, oral examination, and radiographic observations of subjects. The obtained results were as follows: 1. The prevalence of individual dental anomalies were as follows; Congenitally missing teeth 7%; supernumerary teeth 1.33%; ectopic eruption 8.50%; transposition 0.33%; rotation 23.67%; microdontia 11.16% (peg lateral is 5.33%; third molar 5.83%); prolonged retention of deciduous teeth 1.33%; crowding 49.83%; and spacing 15.17%. 2. Alterations in numbers of teeth : The most frequently missing teeth were mandibular lateral incisors, followed by mandibular second premolars and maxillary second premolars. In numbers of congenitally missing teeth per person, 52.38% had one missing tooth and 30.95% had two missing teeth. In supernumerary teeth, there was higher rate in male than in female. Most supernumerary teeth were mesiodens of median area in maxilla and the eruption pattern of that teeth generally was unerupted state. 3. In transposition, exchange of position of teeth involved the canine and first premolar. 4. Congenital missing rate of permanent successors in prolonged retention of deciduous teeth was 69.23%. 5. Crowding and spacing had respectively higher rate in mandible and in maxilla.

  11. Axial anomalies of Lifshitz fermions

    CERN Document Server

    Bakas, Ioannis

    2011-01-01

    We compute the axial anomaly of a Lifshitz fermion theory with anisotropic scaling z=3 which is minimally coupled to geometry in 3+1 space-time dimensions. We find that the result is identical to the relativistic case using path integral methods. An independent verification is provided by showing with spectral methods that the eta-invariant of the Dirac and Lifshitz fermion operators in three dimensions are equal. Thus, by the integrated form of the anomaly, the index of the Dirac operator still accounts for the possible breakdown of chiral symmetry in non-relativistic theories of gravity. We apply this framework to the recently constructed gravitational instanton backgrounds of Horava-Lifshitz theory and find that the index is non-zero provided that the space-time foliation admits leaves with harmonic spinors. Using Hitchin's construction of harmonic spinors on Berger spheres, we obtain explicit results for the index of the fermion operator on all such gravitational instanton backgrounds with SU(2)xU(1) isom...

  12. A study of dental anomalies

    International Nuclear Information System (INIS)

    Yang, Sook; Kim, Jae Duck

    1993-01-01

    The purpose of this study was to find out the prevalence of dental anomalies in 600 normal persons (male:363, female:237) at age 14 to 39 years, through history taking, oral examination, and radiographic observations of subjects. The obtained results were as follows: 1. The prevalence of individual dental anomalies were as follows; Congenitally missing teeth 7%; supernumerary teeth 1.33%; ectopic eruption 8.50%; transposition 0.33%; rotation 23.67%; microdontia 11.16% (peg lateral is 5.33%; third molar 5.83%); prolonged retention of deciduous teeth 1.33%; crowding 49.83%; and spacing 15.17%. 2. Alterations in numbers of teeth : The most frequently missing teeth were mandibular lateral incisors, followed by mandibular second premolars and maxillary second premolars. In numbers of congenitally missing teeth per person, 52.38% had one missing tooth and 30.95% had two missing teeth. In supernumerary teeth, there was higher rate in male than in female. Most supernumerary teeth were mesiodens of median area in maxilla and the eruption pattern of that teeth generally was unerupted state. 3. In transposition, exchange of position of teeth involved the canine and first premolar. 4. Congenital missing rate of permanent successors in prolonged retention of deciduous teeth was 69.23%. 5. Crowding and spacing had respectively higher rate in mandible and in maxilla.

  13. Global anomalies in chiral lattice gauge theories

    International Nuclear Information System (INIS)

    Baer, O.

    2000-07-01

    We study global anomalies in a new approach to chiral gauge theories on the lattice, which is based on the Ginsparg-Wilson relation. In this approach, global anomalies make it impossible to define consistently a fermionic measure for the functional integral. We show that a global anomaly occurs in an SU(2) theory if the fundamental representation is used for the fermion fields. The generalization to higher representations is also discussed. In addition we establish a close relation between global anomalies and the spectral flow of the Dirac operator and employ it in a numerical computation to prove the existence of the global SU(2) anomaly in a different way. This method is inspired by an earlier work of Witten who first discovered this type of anomalies in continuum field theory. (orig.)

  14. The "Parity" Anomaly On An Unorientable Manifold

    OpenAIRE

    Witten, Edward

    2016-01-01

    The "parity" anomaly -- more accurately described as an anomaly in time-reversal or reflection symmetry -- arises in certain theories of fermions coupled to gauge fields and/or gravity in a spacetime of odd dimension. This anomaly has traditionally been studied on orientable manifolds only, but recent developments involving topological superconductors have made it clear that one can get more information by asking what happens on an unorientable manifold. In this paper, we give a full descript...

  15. Monitoring of congenital anomalies in Latvia.

    Science.gov (United States)

    Irisa Zilie; ViIIeruša, Anita; Gissler, Mika

    2014-09-01

    This study provides a description and analysis of characteristics of the monitoring system for congenital anomalies at birth and prevalence trends in Latvia using retrospective analysis of congenital anomalies at birth with cross-sectional data on prevalence (national data from Latvia, 2000-2010). There are three main monitoring systems on congenital anomalies among newborns and infants: the Medical Birth Register with data on live births with one or more congenital anomalies at birth, the Register on Congenital Anomalies with genetically approved cases for live births and the National Causes of Death Register with data on stillbirths. Methodological problems were analysed by calculating different prevalence rates. The main outcome measures are as follows: prevalence rate, live birth prevalence rate, major congenital anomalies live birth prevalence rate, and stillbirth rate. The live birth period prevalence was 319.7/10,000 live births, and the majoir congenital anomalies live birth prevalence was 211.4/10,000. The period total prevalence rate of births was.323.7/10,000 live births and stillbirths. The stillbirth rate due to congenital anomalies was 6.1/10,000 live and stillbirths. The live birth prevalence with congenital anomalies decreased slightly from the year 2000 tothe year 2010. The present system of congenital anomaly registration requires improvements for better completeness. Latvia should use the experience.of Nordic countries and introduce a mother's and children's identification number to the Medical Birth Register. It would be helpful to link the information from hospitals and perinatal centres together to validate the congenital anomaly diagnoses of newborns after their discharge from the maternity unit. The monitoring system should also include information on pregnancies with congenital anomalies which do not end in birth, especially terminations of pregnancy.

  16. Associated anomalies in cases with esophageal atresia.

    Science.gov (United States)

    Stoll, Claude; Alembik, Yves; Dott, Beatrice; Roth, Marie-Paule

    2017-08-01

    Esophageal atresia (EA) is a common type of congenital anomaly. The etiology of esophageal atresia is unclear and its pathogenesis is controversial. Infants with esophageal atresia often have other non-EA associated congenital anomalies. The purpose of this investigation was to assess the prevalence and the types of these associated anomalies in a defined population. The associated anomalies in cases with EA were collected in all livebirths, stillbirths, and terminations of pregnancy during 29 years in 387,067 consecutive births in the area covered by our population-based registry of congenital malformations. Of the 116 cases with esophageal atresia, representing a prevalence of 2.99 per 10,000, 54 (46.6%) had associated anomalies. There were 9 (7.8%) cases with chromosomal abnormalities including 6 trisomies 18, and 20 (17.2%) nonchromosomal recognized dysmorphic conditions including 12 cases with VACTERL association and 2 cases with CHARGE syndrome. Twenty five (21.6%) of the cases had multiple congenital anomalies (MCA). Anomalies in the cardiovascular, the digestive, the urogenital, the musculoskeletal, and the central nervous systems were the most common other anomalies. The anomalies associated with esophageal atresia could be classified into a recognizable malformation syndrome or pattern in 29 out of 54 cases (53.7%). This study included special strengths: each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for anomalies was continued until 2 years of age. In conclusion the overall prevalence of associated anomalies, which was close to one in two cases, emphasizes the need for a thorough investigation of cases with EA. A routine screening for other anomalies may be considered in infants and in fetuses with EA. © 2017 Wiley Periodicals, Inc.

  17. Network anomaly detection a machine learning perspective

    CERN Document Server

    Bhattacharyya, Dhruba Kumar

    2013-01-01

    With the rapid rise in the ubiquity and sophistication of Internet technology and the accompanying growth in the number of network attacks, network intrusion detection has become increasingly important. Anomaly-based network intrusion detection refers to finding exceptional or nonconforming patterns in network traffic data compared to normal behavior. Finding these anomalies has extensive applications in areas such as cyber security, credit card and insurance fraud detection, and military surveillance for enemy activities. Network Anomaly Detection: A Machine Learning Perspective presents mach

  18. On Newton-Cartan trace anomalies

    International Nuclear Information System (INIS)

    Auzzi, Roberto; Baiguera, Stefano; Nardelli, Giuseppe

    2016-01-01

    We classify the trace anomaly for parity-invariant non-relativistic Schrödinger theories in 2+1 dimensions coupled to background Newton-Cartan gravity. The general anomaly structure looks very different from the one in the z=2 Lifshitz theories. The type A content of the anomaly is remarkably identical to that of the relativistic 3+1 dimensional case, suggesting the conjecture that an a-theorem should exist also in the Newton-Cartan context.

  19. Anomaly Detection from Hyperspectral Remote Sensing Imagery

    Directory of Open Access Journals (Sweden)

    Qiandong Guo

    2016-12-01

    Full Text Available Hyperspectral remote sensing imagery contains much more information in the spectral domain than does multispectral imagery. The consecutive and abundant spectral signals provide a great potential for classification and anomaly detection. In this study, two real hyperspectral data sets were used for anomaly detection. One data set was an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS data covering the post-attack World Trade Center (WTC and anomalies are fire spots. The other data set called SpecTIR contained fabric panels as anomalies compared to their background. Existing anomaly detection algorithms including the Reed–Xiaoli detector (RXD, the blocked adaptive computation efficient outlier nominator (BACON, the random selection based anomaly detector (RSAD, the weighted-RXD (W-RXD, and the probabilistic anomaly detector (PAD are reviewed here. The RXD generally sets strict assumptions to the background, which cannot be met in many scenarios, while BACON, RSAD, and W-RXD employ strategies to optimize the estimation of background information. The PAD firstly estimates both background information and anomaly information and then uses the information to conduct anomaly detection. Here, the BACON, RSAD, W-RXD, and PAD outperformed the RXD in terms of detection accuracy, and W-RXD and PAD required less time than BACON and RSAD.

  20. Tectonically Induced Anomalies Without Large Earthquake Occurrences

    Science.gov (United States)

    Shi, Zheming; Wang, Guangcai; Liu, Chenglong; Che, Yongtai

    2017-06-01

    In this study, we documented a case involving large-scale macroscopic anomalies in the Xichang area, southwestern Sichuan Province, China, from May to June of 2002, after which no major earthquake occurred. During our field survey in 2002, we found that the timing of the high-frequency occurrence of groundwater anomalies was in good agreement with those of animal anomalies. Spatially, the groundwater and animal anomalies were distributed along the Anninghe-Zemuhe fault zone. Furthermore, the groundwater level was elevated in the northwest part of the Zemuhe fault and depressed in the southeast part of the Zemuhe fault zone, with a border somewhere between Puge and Ningnan Counties. Combined with microscopic groundwater, geodetic and seismic activity data, we infer that the anomalies in the Xichang area were the result of increasing tectonic activity in the Sichuan-Yunnan block. In addition, groundwater data may be used as a good indicator of tectonic activity. This case tells us that there is no direct relationship between an earthquake and these anomalies. In most cases, the vast majority of the anomalies, including microscopic and macroscopic anomalies, are caused by tectonic activity. That is, these anomalies could occur under the effects of tectonic activity, but they do not necessarily relate to the occurrence of earthquakes.

  1. MRI of central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Izawa, M.; Oikawa, A.; Matoba, A.

    1987-05-01

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions.

  2. Spreading rate dependence of gravity anomalies along oceanic transform faults.

    Science.gov (United States)

    Gregg, Patricia M; Lin, Jian; Behn, Mark D; Montési, Laurent G J

    2007-07-12

    Mid-ocean ridge morphology and crustal accretion are known to depend on the spreading rate of the ridge. Slow-spreading mid-ocean-ridge segments exhibit significant crustal thinning towards transform and non-transform offsets, which is thought to arise from a three-dimensional process of buoyant mantle upwelling and melt migration focused beneath the centres of ridge segments. In contrast, fast-spreading mid-ocean ridges are characterized by smaller, segment-scale variations in crustal thickness, which reflect more uniform mantle upwelling beneath the ridge axis. Here we present a systematic study of the residual mantle Bouguer gravity anomaly of 19 oceanic transform faults that reveals a strong correlation between gravity signature and spreading rate. Previous studies have shown that slow-slipping transform faults are marked by more positive gravity anomalies than their adjacent ridge segments, but our analysis reveals that intermediate and fast-slipping transform faults exhibit more negative gravity anomalies than their adjacent ridge segments. This finding indicates that there is a mass deficit at intermediate- and fast-slipping transform faults, which could reflect increased rock porosity, serpentinization of mantle peridotite, and/or crustal thickening. The most negative anomalies correspond to topographic highs flanking the transform faults, rather than to transform troughs (where deformation is probably focused and porosity and alteration are expected to be greatest), indicating that crustal thickening could be an important contributor to the negative gravity anomalies observed. This finding in turn suggests that three-dimensional magma accretion may occur near intermediate- and fast-slipping transform faults.

  3. Low velocity impact analysis with NASTRAN

    Science.gov (United States)

    Trowbridge, D. A.; Grady, J. E.; Aiello, R. A.

    1991-01-01

    A nonlinear elastic force-displacement relationship is used to calculate the transient impact force and local deformation at the point of contact between impactor and target. The nonlinear analysis and transfer function capabilities of NASTRAN are used to define a finite element model that behaves globally linearly elastic, and locally nonlinear elastic to model the local contact behavior. Results are presented for two different structures: a uniform cylindrical rod impacted longitudinally; and an orthotropic plate impacted transversely. Calculated impact force and transient structural response of the targets are shown to compare well with results measured in experimental tests.

  4. Aorta Ascending Aneurysm Analysis Using CFD Models towards Possible Anomalies

    Directory of Open Access Journals (Sweden)

    Mariana Simão

    2017-06-01

    Full Text Available Computational fluid dynamics (CFD can be seen as complementary tool alongside the visualization capabilities of cardiovascular magnetic resonance (CMR and computed tomography (CT imaging for decision-making. In this research CT images of three cases (i.e., a healthy heart pilot project and two patients with complex aortic disease are used to validate and analyse the corresponding computational results. Three 3D domains of the thoracic aorta were tested under hemodynamic conditions. Under normal conditions, the flow inside the thoracic aorta is more streamlined. In the presence of ascending aortic aneurysm, large areas of blue separation zones (i.e., low velocities are identified, as well as an internal geometry deformation of the aortic wall, respectively. This flow separation is characterized by the reversal of flow and sudden drop of the wall shear stress (WSS in the aorta. Moreover, the aortic aneurysm simulations adversely affect the flow by increasing the pressure drop and flow inefficiency, due to the anatomical configuration of the ascending aorta. Altered hemodynamics led to a vortex formation and locally reversed the flow that eventually induced a low flow velocity and oscillating WSS in the thoracic aorta. Significant changes in the hemodynamic characteristics affect the normal blood circulation with strong turbulence occurrence, damaging the aortic wall, leading ultimately to the need of surgical intervention to avoid fatal events.

  5. GRAVITY ANOMALIES OF THE MOON

    Directory of Open Access Journals (Sweden)

    S. G. Pugacheva

    2015-01-01

    Full Text Available The source of gravity anomalies of the Moon are large mascons with a high mass concentration at a depth of volcanic plains and lunar Maria. New data on the gravitational field of the Moon were obtained from two Grail spacecrafts. The article presents the data of physical and mechanical properties of the surface soil layer of the lunar Maria and gives an assessment of the chemical composition of the soil. There have been calculated heterogeneity parameters of the surface macro-relief of the lunar Maria: albedo, soil density, average grain diameter of the particles forming the surface layer and the volume fraction occupied by particles. It can be assumed that mascons include rich KREEP rocks with a high content of thorium and iron oxide. Formation of mascons is connected with intensive development of basaltic volcanism on the Moon in the early periods of its existence.

  6. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  7. Hydrogeophysical exploration of three-dimensional salinity anomalies with the time-domain electromagnetic method (TDEM)

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Christiansen, Lars

    2010-01-01

    Delta is presented. Evaporative salt enrichment causes a strong salinity anomaly under the island. We show that the TDEM field data cannot be interpreted in terms of standard one-dimensional layered-earth TDEM models, because of the strongly three-dimensional nature of the salinity anomaly. Three......The time-domain electromagnetic method (TDEM) is widely used in groundwater exploration and geological mapping applications. TDEM measures subsurface electrical conductivity, which is strongly correlated with groundwater salinity. TDEM offers a cheap and non-invasive option for mapping saltwater...... intrusion and groundwater salinization. Traditionally, TDEM data is interpreted using one-dimensional layered-earth models of the subsurface. However, most saltwater intrusion and groundwater salinization phenomena are characterized by three-dimensional anomalies. To fully exploit the information content...

  8. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  9. Hawking radiation of black rings from anomalies

    International Nuclear Information System (INIS)

    Chen Bin; He Wei

    2008-01-01

    We derive Hawking radiation of five-dimensional black rings from gauge and gravitational anomalies using the method proposed by Robinson and Wilczek. We find, as in the black hole case, that the problem could reduce to a (1+1)-dimensional field theory and the anomalies result in correct Hawking temperature for neutral, dipole and charged black rings

  10. Praenatalt diagnosticeret hydronefrose og andre urologiske anomalier

    DEFF Research Database (Denmark)

    Cortes, Dina; Jørgensen, Troels Munch; Rittig, Søren

    2006-01-01

    By renal ultrasound examination, urological anomalies may be demonstrated in 1-2% of fetuses and in about 0.5% of newborns. Boys have about twice the frequency of girls. Surgical treatment is indicated in about one fourth of these urological anomalies. If all pregnant women in Denmark were to hav...

  11. Anomalies of Nuclear Criticality, Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, E. D.; Prichard, Andrew W.; Durst, Bonita E.; Erickson, David; Puigh, Raymond J.

    2010-02-19

    This report is revision 6 of the Anomalies of Nuclear Criticality. This report is required reading for the training of criticality professionals in many organizations both nationally and internationally. This report describes many different classes of nuclear criticality anomalies that are different than expected.

  12. Socio-occupational status and congenital anomalies

    DEFF Research Database (Denmark)

    Varela, María M Morales-Suárez; Nohr, Ellen Aagaard; Llopis-González, Agustin

    2009-01-01

    The aim of this study is to investigate the association between socio-occupational status and the frequency of major congenital anomalies in offspring.......The aim of this study is to investigate the association between socio-occupational status and the frequency of major congenital anomalies in offspring....

  13. Improved prenatal detection of chromosomal anomalies

    DEFF Research Database (Denmark)

    Frøslev-Friis, Christina; Hjort-Pedersen, Karina; Henriques, Carsten U

    2011-01-01

    Prenatal screening for karyotype anomalies takes place in most European countries. In Denmark, the screening method was changed in 2005. The aim of this study was to study the trends in prevalence and prenatal detection rates of chromosome anomalies and Down syndrome (DS) over a 22-year period....

  14. Interpretation of Aeromagnetic Anomalies over Abeokuta, Southwest ...

    African Journals Online (AJOL)

    ADOWIE PERE

    of the bodies producing the magnetic anomaly. ∑. 1. Where. L = length of the cross—section of the anomaly n = harmonic number of the partial wave. N = number of data point real path partial amplitude imaginary path of FFT. RESULTS AND DISCUSSION. Table 1 summarizes depths values of various anomalous sources.

  15. Vibrational anomalies and marginal stability of glasses

    KAUST Repository

    Marruzzo, Alessia

    2013-01-01

    The experimentally measured vibrational spectrum of glasses strongly deviates from that expected in Debye\\'s elasticity theory: The density of states deviates from Debye\\'s ω2 law ("boson peak"), the sound velocity shows a negative dispersion in the boson-peak frequency regime, and there is a strong increase in the sound attenuation near the boson-peak frequency. A generalized elasticity theory is presented, based on the model assumption that the shear modulus of the disordered medium fluctuates randomly in space. The fluctuations are assumed to be uncorrelated and have a certain distribution (Gaussian or otherwise). Using field-theoretical techniques one is able to derive mean-field theories for the vibrational spectrum of a disordered system. The theory based on a Gaussian distribution uses a self-consistent Born approximation (SCBA),while the theory for non-Gaussian distributions is based on a coherent-potential approximation (CPA). Both approximate theories appear to be saddle-point approximations of effective replica field theories. The theory gives a satisfactory explanation of the vibrational anomalies in glasses. Excellent agreement of the SCBA theory with simulation data on a soft-sphere glass is reached. Since the SCBA is based on a Gaussian distribution of local shear moduli, including negative values, this theory describes a shear instability as a function of the variance of shear fluctuations. In the vicinity of this instability, a fractal frequency dependence of the density of states and the sound attenuation ∝ ω1+a is predicted with a ≲ 1/2. Such a frequency dependence is indeed observed both in simulations and in experimental data. We argue that the observed frequency dependence stems from marginally stable regions in a glass and discuss these findings in terms of rigidity percolation. © 2013 EDP Sciences and Springer.

  16. Deep Sources: New constraints on the tectonic origin of the Klyuchevskoy Group upper mantle anomaly

    Science.gov (United States)

    Bourke, J. R.; Nikulin, A.; Levin, V. L.

    2017-12-01

    Volcanoes of the Klyuchevskoy Group (KG) form one of the most active volcanic clusters on the planet, yet its position relative to the subducting Pacific Plate seems to be in violation of the understood principles of the flux-induced arc volcanism. Positioned at 170km above the accepted subduction contact, the KG is seemingly outside the maximum fluid flux release zone of 100km, as observed across global subduction zone environments. Past geophysical studies indicate presence of a planar seismic anomaly 110km below the KG, and it has been noted that the KG lavas exhibit anomalous geochemical signatures, possibly associated with two separate melt generation regions. This interpretation was largely based on receiver function analysis of seismic data recorded by 3 stations of the Partnership in International Research and Education (PIRE) network, done prior to this data becoming publically available. We present results of receiver function and a teleseismic, regional, and local source shear wave splitting study, focused on datasets obtained by the full PIRE network of 12 stations, as well as a hybrid summation of all stations. We present our findings in the form of depth migrated receiver function images convolved with a three-dimensional model of the subduction zone and shear-wave splitting measurements. Our results vastly increase the resolution of the previously identified upper mantle anomaly, further constraining its geometry both vertically and laterally. We complement our observations with a forward modeling effort aimed at assessing the geological nature of the anomaly. Specifically, we test three scenarios that were previously invoked to explain the presence of the low-velocity anomaly in the upper mantle below the KG: a 3D flow of mantle material around the corner of the subducting Pacific Plate, a sinking paleoslab left behind as a result of subduction rollback, and a plume of sediments from the subducting plate. We show that presence of remnant paleoslab

  17. Epididymal anomalies associated with patent processus vaginalis in hydrocele and cryptorchidism.

    Science.gov (United States)

    Han, Chang Hee; Kang, Sung Hak

    2002-01-01

    The epididymal anomalies and patent processus vaginalis are frequently seen in patients with cryptorchidism or hydrocele. We performed a prospective study on the relationship between the epididymal anomalies and the patency of the processus vaginalis in boys with hydrocele (190 cases) or cryptorchidism (89 cases) who were treated from August 1997 to February 2000 (mean age, 51 months; range, 12 to 152 months). The epididymal anomalies were observed with an overall frequency of 48%. Closed, partially closed, and open processus vaginalis were associated with an epididymal anomaly in 14, 38, and 65% of cases, respectively. The epididymal anomalies were more common in association with undescended (61%) than with descended (43%) testes without statistical significance (p=0.415). Incomplete attachment of the caput epididymis was the most common anomaly (35%), followed by detachment of caput and cauda epididymis (31%), cauda epididymis (24%), and long looping epididymis (10%). These data showed that the epididymal anomalies were strongly associated with the patency of the processus vaginalis irrespective of testicular descent (p<0.001), and they provide further evidence for the hypothesis that a common stimulus, possibly androgens, may be required for the epididymal development and obliteration of the processus vaginalis. PMID:12378019

  18. Sea surface temperature anomalies in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.

    temperature anomalies for the above regions respectively. An analysis has shown that most of the short duration anomalies (i.e., anomalies with periods less than 4 months) are driven by the surface heat fluxes. The medium duration anomalies (i.e., anomalies...

  19. Regional magnetic anomaly constraints on continental rifting

    Science.gov (United States)

    Vonfrese, R. R. B.; Hinze, W. J.; Olivier, R.; Bentley, C. R.

    1985-01-01

    Radially polarized MAGSAT anomalies of North and South America, Europe, Africa, India, Australia and Antarctica demonstrate remarkably detailed correlation of regional magnetic lithospheric sources across rifted margins when plotted on a reconstruction of Pangea. These major magnetic features apparently preserve their integrity until a superimposed metamorphoric event alters the magnitude and pattern of the anomalies. The longevity of continental scale magnetic anomalies contrasts markedly with that of regional gravity anomalies which tend to reflect predominantly isostatic adjustments associated with neo-tectonism. First observed as a result of NASA's magnetic satellite programs, these anomalies provide new and fundamental constraints on the geologic evolution and dynamics of the continents and oceans. Accordingly, satellite magnetic observations provide a further tool for investigating continental drift to compliment other lines of evidence in paleoclimatology, paleontology, paleomagnetism, and studies of the radiometric ages and geometric fit of the continents.

  20. Intracranial developmental venous anomaly: is it asymptomatic?

    Science.gov (United States)

    Puente, A Bolívar; de Asís Bravo Rodríguez, F; Bravo Rey, I; Romero, E Roldán

    2018-03-16

    Intracranial developmental venous anomalies are the most common vascular malformation. In the immense majority of cases, these anomalies are asymptomatic and discovered incidentally, and they are considered benign. Very exceptionally, however, they can cause neurological symptoms. In this article, we present three cases of patients with developmental venous anomalies that presented with different symptoms owing to complications derived from altered venous drainage. These anomalies were located in the left insula, right temporal lobe, and cerebellum. The exceptionality of the cases presented as well as of the images associated, which show the mechanism through which the symptoms developed, lies in the low incidence of symptomatic developmental venous anomalies reported in the literature. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. KIDNEY ANOMALIES: HORSE SHOE KIDNEY

    Directory of Open Access Journals (Sweden)

    Hemalatha

    2015-03-01

    Full Text Available INTRODUCTION : Horse Shoe Kidney was first recognized during an autopsy by De Carpi in 1521. This anomaly consists of two distinct renal masses lying vertically on either side of the midline and connected at their respective lower poles by a parenchymatous or fibrous isthmus that crosses the mid pl ane of the body. This isthmus lies at the level of 4th lumbar vertebra just beneath the origin of inferior mesenteric artery in about 40% of cases. Fusion of upper poles instead of the lower poles results in a n inverted horse Shoe Kidney which constitute 5 - 10% of ail Horse - Shoe kidneys , (i.e. in 95% of HSK , fusion is at lower poles. HSK is found more commonly in males by a 2 : 1 margin. AIM OF STUDY : An attempt has been made to know the various anomalies . The study has been taken up with the fond hope of helping the clinician , sonologist , and surgeons during their routine work. To apply this knowledge to the incoming post graduates in their research works. EMBRIOLOGICAL BASIS & KDNEY : The abnormality originates between 4th and 6th weeks of gestation , after the ureteral bud has entered the renal blastema. Boyden (1931 postulated that at the 14mm stage (4.5 weeks the developing metanephric masses lie close to one another , any disturbance in their relationship may result in joining at their inferior poles. A slight alteration in the position of the umbilical or common iliac artery could change the orientation of migrating kidneys thus leading to contact and fusion. In 1941 Dees (Nation 1945 , Bell 1946 , Gleen 1959 , Campbell 1970 described horse - shoe kidney di sease occurrence in 0.25% of the population or about 1 in 400. OBSERVATION : In the present study 176 specimens of kidneys were studied out of which 40 were fetal specimens and the rest were adult specimens consisting of both cadaveric and sonograms. The ad ult specimens from cadavers were 76 and 60 from sonograms. MATERIAL & METHODS : Abdomen is opened ; superficial viscera and

  2. Anomaly Detection in Dynamic Networks

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, Melissa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-14

    Anomaly detection in dynamic communication networks has many important security applications. These networks can be extremely large and so detecting any changes in their structure can be computationally challenging; hence, computationally fast, parallelisable methods for monitoring the network are paramount. For this reason the methods presented here use independent node and edge based models to detect locally anomalous substructures within communication networks. As a first stage, the aim is to detect changes in the data streams arising from node or edge communications. Throughout the thesis simple, conjugate Bayesian models for counting processes are used to model these data streams. A second stage of analysis can then be performed on a much reduced subset of the network comprising nodes and edges which have been identified as potentially anomalous in the first stage. The first method assumes communications in a network arise from an inhomogeneous Poisson process with piecewise constant intensity. Anomaly detection is then treated as a changepoint problem on the intensities. The changepoint model is extended to incorporate seasonal behavior inherent in communication networks. This seasonal behavior is also viewed as a changepoint problem acting on a piecewise constant Poisson process. In a static time frame, inference is made on this extended model via a Gibbs sampling strategy. In a sequential time frame, where the data arrive as a stream, a novel, fast Sequential Monte Carlo (SMC) algorithm is introduced to sample from the sequence of posterior distributions of the change points over time. A second method is considered for monitoring communications in a large scale computer network. The usage patterns in these types of networks are very bursty in nature and don’t fit a Poisson process model. For tractable inference, discrete time models are considered, where the data are aggregated into discrete time periods and probability models are fitted to the

  3. Ferromagnetic spin coupling as the origin of 0.7 anomaly in quantum point contacts.

    Science.gov (United States)

    Aryanpour, K; Han, J E

    2009-02-06

    We study one-dimensional itinerant electron models with ferromagnetic coupling to investigate the origin of the 0.7 anomaly in quantum point contacts. Linear conductance calculations from the quantum Monte Carlo technique for spin interactions of different spatial range suggest that 0.7(2e;{2}/h) anomaly results from a strong interaction of low-density conduction electrons to ferromagnetic fluctuations formed across the potential barrier. The conductance plateau appears due to the strong incoherent scattering at high temperature when the electron traversal time matches the time scale of dynamic ferromagnetic excitations.

  4. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  5. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  6. Development of the experimental procedure to examine the response of carbon fiber-reinforced polymer composites subjected to a high-intensity pulsed electric field and low-velocity impact.

    Science.gov (United States)

    Hart, Robert J; Zhupanska, Olesya I

    2016-01-01

    A new fully automated experimental setup has been developed to study the response of carbon fiber reinforced polymer (CFRP) composites subjected to a high-intensity pulsed electric field and low-velocity impact. The experimental setup allows for real-time measurements of the pulsed electric current, voltage, impact load, and displacements on the CFRP composite specimens. The setup includes a new custom-built current pulse generator that utilizes a bank of capacitor modules capable of producing a 20 ms current pulse with an amplitude of up to 2500 A. The setup enabled application of the pulsed current and impact load and successfully achieved coordination between the peak of the current pulse and the peak of the impact load. A series of electrical, impact, and coordinated electrical-impact characterization tests were performed on 32-ply IM7/977-3 unidirectional CFRP composites to assess their ability to withstand application of a pulsed electric current and determine the effects of the pulsed current on the impact response. Experimental results revealed that the electrical resistance of CFRP composites decreased with an increase in the electric current magnitude. It was also found that the electrified CFRP specimens withstood higher average impact loads compared to the non-electrified specimens.

  7. Development of the experimental procedure to examine the response of carbon fiber-reinforced polymer composites subjected to a high-intensity pulsed electric field and low-velocity impact

    Science.gov (United States)

    Hart, Robert J.; Zhupanska, Olesya I.

    2016-01-01

    A new fully automated experimental setup has been developed to study the response of carbon fiber reinforced polymer (CFRP) composites subjected to a high-intensity pulsed electric field and low-velocity impact. The experimental setup allows for real-time measurements of the pulsed electric current, voltage, impact load, and displacements on the CFRP composite specimens. The setup includes a new custom-built current pulse generator that utilizes a bank of capacitor modules capable of producing a 20 ms current pulse with an amplitude of up to 2500 A. The setup enabled application of the pulsed current and impact load and successfully achieved coordination between the peak of the current pulse and the peak of the impact load. A series of electrical, impact, and coordinated electrical-impact characterization tests were performed on 32-ply IM7/977-3 unidirectional CFRP composites to assess their ability to withstand application of a pulsed electric current and determine the effects of the pulsed current on the impact response. Experimental results revealed that the electrical resistance of CFRP composites decreased with an increase in the electric current magnitude. It was also found that the electrified CFRP specimens withstood higher average impact loads compared to the non-electrified specimens.

  8. Data Mining for Anomaly Detection

    Science.gov (United States)

    Biswas, Gautam; Mack, Daniel; Mylaraswamy, Dinkar; Bharadwaj, Raj

    2013-01-01

    The Vehicle Integrated Prognostics Reasoner (VIPR) program describes methods for enhanced diagnostics as well as a prognostic extension to current state of art Aircraft Diagnostic and Maintenance System (ADMS). VIPR introduced a new anomaly detection function for discovering previously undetected and undocumented situations, where there are clear deviations from nominal behavior. Once a baseline (nominal model of operations) is established, the detection and analysis is split between on-aircraft outlier generation and off-aircraft expert analysis to characterize and classify events that may not have been anticipated by individual system providers. Offline expert analysis is supported by data curation and data mining algorithms that can be applied in the contexts of supervised learning methods and unsupervised learning. In this report, we discuss efficient methods to implement the Kolmogorov complexity measure using compression algorithms, and run a systematic empirical analysis to determine the best compression measure. Our experiments established that the combination of the DZIP compression algorithm and CiDM distance measure provides the best results for capturing relevant properties of time series data encountered in aircraft operations. This combination was used as the basis for developing an unsupervised learning algorithm to define "nominal" flight segments using historical flight segments.

  9. Collie Eye Anomaly in Switzerland.

    Science.gov (United States)

    Walser-Reinhardt, L; Hässig, M; Spiess, B

    2009-12-01

    In this retrospective study, the results of 3'527 eye examinations in 6 different breeds affected with Collie Eye Anomaly (CEA) over a period of 8 years (1999 - 2007) are described. CEA was divided into three main ophthalmoscopic features, a) choroidal hypoplasia (CRH), b) CRH and coloboma and c) coloboma alone. Of the 101 Smooth Collies 8.9 % showed signs of CRH, whereas 36.9 % of Rough Collies were affected with CRH, 2.8 % with CRH and coloboma and 0.38 % with coloboma alone. Choroidal hypoplasia was present in 13.1 %, CRH and coloboma in 1.8 % and coloboma alone in 0.2 % of the Shetland Sheepdogs. Only one Australian Shepherd dog had CRH, while 0.7 % of the Border Collies were affected with CRH. None of the Nova Scotia Duck Tolling Retrievers were affected with CEA. There were no statistically significant differences in the occurrence of CEA between males and females, nor was there any relation between coat colors. Significant differences could be shown between dogs younger or older than 8 weeks at first examination. CEA was more often diagnosed in dogs younger than 8 weeks within the Rough Collie and Shetland Sheepdog.

  10. Anomalies, Unitarity and Quantum Irreversibility

    CERN Document Server

    Anselmi, D

    1999-01-01

    The trace anomaly in external gravity is the sum of three terms at criticality: the square of the Weyl tensor, the Euler density and Box R, with coefficients, properly normalized, called c, a and a', the latter being ambiguously defined by an additive constant. Unitarity and positivity properties of the induced actions allow us to show that the total RG flows of a and a' are equal and therefore the a'-ambiguity can be consistently removed through the identification a'=a. The picture that emerges clarifies several long-standing issues. The interplay between unitarity and renormalization implies that the flux of the renormalization group is irreversible. A monotonically decreasing a-function interpolating between the appropriate values is naturally provided by a'. The total a-flow is expressed non-perturbatively as the invariant (i.e. scheme-independent) area of the graph of the beta function between the fixed points. We test this prediction to the fourth loop order in perturbation theory, in QCD with Nf ~< ...

  11. Effect of geomagnetic storm conditions on the equatorial ionization anomaly and equatorial temperature anomaly

    Science.gov (United States)

    Bharti, Gaurav; Bag, T.; Sunil Krishna, M. V.

    2018-03-01

    The effect of the geomagnetic storm on the equatorial ionization anomaly (EIA) and equatorial temperature anomaly (ETA) has been studied using the atomic oxygen dayglow emissions at 577.7 nm (OI 557.7 nm) and 732.0 nm (OII 732.0 nm). For the purpose of this study, four intense geomagnetic storms during the ascending phase of solar cycle 24 have been considered. This study is primarily based on the results obtained using photochemical models with necessary inputs from theoretical studies and experimental observations. The latest reaction rate coefficients, quantum yields and the corresponding cross-sections have also been incorporated in these models. The volume emission rate of airglow emissions has been calculated using the neutral densities from NRLMSISE-00 and charged densities from IRI-2012 model. The modeled volume emission rate (VER) for OI 557.7 nm shows a positive correlation with the Dst index at 150 km and negative correlation with Dst at 250 and 280 km altitudes. Latitudinal profile of the greenline emission rate at different altitudes show a distinct behaviour similar to what has been observed in EIA with crests on either sides of the equator. The EIA crests are found to show poleward movement in the higher altitude regions. The volume emission rate of 732.0 nm emission shows a strong enhancement during the main phase of the storm. The changes observed in the airglow emission rates are explained with the help of variations induced in neutral densities and parameters related to EIA and ETA. The latitudinal variation of 732.0 nm emission rate is correlated to the variability in EIA during the storm period.

  12. Axial anomaly and magnetism of nuclear and quark matter

    Science.gov (United States)

    Son, D. T.; Stephanov, M. A.

    2008-01-01

    We consider the response of the QCD ground state at finite baryon density to a strong magnetic field B. We point out the dominant role played by the coupling of neutral Goldstone bosons, such as π0, to the magnetic field via the axial triangle anomaly. We show that, in vacuum, above a value of B˜mπ2/e, a metastable object appears—the π0 domain wall. Because of the axial anomaly, the wall carries a baryon number surface density proportional to B. As a result, for B≳1019G a stack of parallel π0 domain walls is energetically more favorable than nuclear matter at the same density. Similarly, at higher densities, somewhat weaker magnetic fields of order B≳1017 1018G transform the color-superconducting ground state of QCD into new phases containing stacks of axial isoscalar (η or η') domain walls. We also show that a quark-matter state known as “Goldstone current state,” in which a gradient of a Goldstone field is spontaneously generated, is ferromagnetic due to the axial anomaly. We estimate the size of the fields created by such a state in a typical neutron star to be of order 1014 1015G.

  13. Phonon anomalies in trilayer high-Tc cuprate superconductors

    International Nuclear Information System (INIS)

    Dubroka, Adam; Munzar, Dominik

    2004-01-01

    We present an extension of the model proposed recently to account for dramatic chAes below T c (anomalies) of some c-axis polarized infrared-active phonons in bilayer cuprate superconductors, that applies to trilayer high-T c compounds. We discuss several types of phonon anomalies that can occur in these systems and demonstrate that our model is capable of explaining the spectral chAes occurring upon entering the superconducting state in the trilayer compound Tl 2 Ba 2 Ca 2 Cu 3 O 10 . The low-temperature spectra of this compound obtained by Zetterer and coworkers display an additional broad absorption band, similar to the one observed in underdoped YBa 2 Cu 3 O 7-δ and Bi 2 Sr 2 CaCu 2 O 8 . In addition, three phonon modes are strongly anomalous. We attribute the absorption band to the transverse Josephson plasma resonance, similar to that of the bilayer compounds. The phonon anomalies are shown to result from a modification of the local fields induced by the formation of the resonance. The spectral chAes in Tl 2 Ba 2 Ca 2 Cu 3 O 10 are compared with those occurring in Bi 2 Sr 2 Ca 2 Cu 3 O 10 , reported recently by Boris and coworkers

  14. Congenital basis of posterior fossa anomalies

    Science.gov (United States)

    Cotes, Claudia; Bonfante, Eliana; Lazor, Jillian; Jadhav, Siddharth; Caldas, Maria; Swischuk, Leonard

    2015-01-01

    The classification of posterior fossa congenital anomalies has been a controversial topic. Advances in genetics and imaging have allowed a better understanding of the embryologic development of these abnormalities. A new classification schema correlates the embryologic, morphologic, and genetic bases of these anomalies in order to better distinguish and describe them. Although they provide a better understanding of the clinical aspects and genetics of these disorders, it is crucial for the radiologist to be able to diagnose the congenital posterior fossa anomalies based on their morphology, since neuroimaging is usually the initial step when these disorders are suspected. We divide the most common posterior fossa congenital anomalies into two groups: 1) hindbrain malformations, including diseases with cerebellar or vermian agenesis, aplasia or hypoplasia and cystic posterior fossa anomalies; and 2) cranial vault malformations. In addition, we will review the embryologic development of the posterior fossa and, from the perspective of embryonic development, will describe the imaging appearance of congenital posterior fossa anomalies. Knowledge of the developmental bases of these malformations facilitates detection of the morphological changes identified on imaging, allowing accurate differentiation and diagnosis of congenital posterior fossa anomalies. PMID:26246090

  15. MR imaging of paediatric uterovaginal anomalies

    International Nuclear Information System (INIS)

    Lang, I.M.; Babyn, P.; Oliver, G.D.

    1999-01-01

    Background. Transabdominal ultrasound (US) has not proved completely reliable in Muellerian duct anomalies. One study has shown it useful in obstructed uterovaginal anomalies. We are unaware of a study that has used endovaginal ultrasound in children to investigate uterovaginal anomalies. Magnetic resonance imaging (MRI) is now gaining wide acceptance in imaging congenital abnormalities of the genital tract. Objective. To identify the problems and potential pitfalls of using MRI to evaluate the female genital tract in paediatric patients. Materials and methods. A retrospective review of the MRI scans of 19 patients, aged 3 months to 19 years (mean 14 years), with uterovaginal anomalies. Results. The uterovaginal anomalies were categorised into three groups: (1) congenital absence of the Muellerian ducts, or the Mayer-Rokitansky-Kuster-Hauser syndrome (n = 7), (2) disorders of vertical fusion (n = 2) and (3) disorders of lateral fusion (n = 10). Conclusions. MRI is a reliable method for evaluating paediatric uterovaginal anomalies, but should be analysed in conjunction with other imaging modalities (US and genitography). Previous surgery makes interpretation more difficult and, if possible, MRI should be carried out prior to any surgery. An accurate MRI examination can be extremely helpful prior to surgery and it is important for the radiologist to have knowledge of how these complex anomalies are managed and what pitfalls to avoid. (orig.)

  16. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  17. Occurrence and Detectability of Thermal Anomalies on Europa

    Science.gov (United States)

    Hayne, Paul O.; Christensen, Philip R.; Spencer, John R.; Abramov, Oleg; Howett, Carly; Mellon, Michael; Nimmo, Francis; Piqueux, Sylvain; Rathbun, Julie A.

    2017-10-01

    Endogenic activity is likely on Europa, given its young surface age of and ongoing tidal heating by Jupiter. Temperature is a fundamental signature of activity, as witnessed on Enceladus, where plumes emanate from vents with strongly elevated temperatures. Recent observations suggest the presence of similar water plumes at Europa. Even if plumes are uncommon, resurfacing may produce elevated surface temperatures, perhaps due to near-surface liquid water. Detecting endogenic activity on Europa is one of the primary mission objectives of NASA’s planned Europa Clipper flyby mission.Here, we use a probabilistic model to assess the likelihood of detectable thermal anomalies on the surface of Europa. The Europa Thermal Emission Imaging System (E-THEMIS) investigation is designed to characterize Europa’s thermal behavior and identify any thermal anomalies due to recent or ongoing activity. We define “detectability” on the basis of expected E-THEMIS measurements, which include multi-spectral infrared emission, both day and night.Thermal anomalies on Europa may take a variety of forms, depending on the resurfacing style, frequency, and duration of events: 1) subsurface melting due to hot spots, 2) shear heating on faults, and 3) eruptions of liquid water or warm ice on the surface. We use numerical and analytical models to estimate temperatures for these features. Once activity ceases, lifetimes of thermal anomalies are estimated to be 100 - 1000 yr. On average, Europa’s 10 - 100 Myr surface age implies a resurfacing rate of ~3 - 30 km2/yr. The typical size of resurfacing features determines their frequency of occurrence. For example, if ~100 km2 chaos features dominate recent resurfacing, we expect one event every few years to decades. Smaller features, such as double-ridges, may be active much more frequently. We model each feature type as a statistically independent event, with probabilities weighted by their observed coverage of Europa’s surface. Our results

  18. Analysis of renal anomalies in VACTERL association.

    Science.gov (United States)

    Cunningham, Bridget K; Khromykh, Alina; Martinez, Ariel F; Carney, Tyler; Hadley, Donald W; Solomon, Benjamin D

    2014-10-01

    VACTERL association refers to a combination of congenital anomalies that can include: vertebral anomalies, anal atresia, cardiac malformations, tracheo-esophageal fistula with esophageal atresia, renal anomalies (typically structural renal anomalies), and limb anomalies. We conducted a description of a case series to characterize renal findings in a cohort of patients with VACTERL association. Out of the overall cohort, 48 patients (with at least three component features of VACTERL and who had abdominal ultrasound performed) met criteria for analysis. Four other patients were additionally analyzed separately, with the hypothesis that subtle renal system anomalies may occur in patients who would not otherwise meet criteria for VACTERL association. Thirty-three (69%) of the 48 patients had a clinical manifestation affecting the renal system. The most common renal manifestation (RM) was vesicoureteral reflux (VUR) in addition to a structural defect (present in 27%), followed by unilateral renal agenesis (24%), and then dysplastic/multicystic kidneys or duplicated collected system (18% for each). Twenty-two (88%) of the 25 patients with a structural RM had an associated anorectal malformation. Individuals with either isolated lower anatomic anomalies, or both upper and lower anatomic anomalies were not statistically more likely to have a structural renal defect than those with isolated upper anatomic anomalies (p = 0.22, p = 0.284, respectively). Given the high prevalence of isolated VUR in our cohort, we recommend a screening VCUG or other imaging modality be obtained to evaluate for VUR if initial renal ultrasound shows evidence of obstruction or renal scarring, as well as ongoing evaluation of renal health. © 2014 Wiley Periodicals, Inc.

  19. Gravity anomalies and crustal structure of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Krishna, K.S.; Murthy, I.V.R.; Sarma, K.V.L.N.S.; Desa, M.; Ramana, M.V.; KameshRaju, K.A.

    of Oceanography (NIO), Goa, India. The study con¢rmed strong negative gravity anomalies associated with the 85‡E Ridge, but its structure and density cannot explain them. The Bengal Fan is typical in many ways prompting repeated geological and geophysical in... and Planetary Science Letters 192 (2001) 447^456448 Moore [4] as a subsurface basement rise along the 85‡E longitude, is buried under deep sediment cover of 3^5 km thickness. While the Ninetyeast Ridge is decisively con¢rmed to be an emplace- ment...

  20. B-decay anomalies in Pati-Salam SU(4)

    Science.gov (United States)

    Barbieri, Riccardo; Tesi, Andrea

    2018-03-01

    Attempts to incorporate in a coherent picture the B-decay anomalies presumably observed in b→ c and b→ s semi-leptonic decays have to face the absence of signals in other related experiments, both at low and at high energies. By extending and making more precise the content of Barbieri et al. (Eur Phys J C 77(1):8, 2017), we describe one such attempt based on the Pati-Salam SU(4) group, that unifies colour and the B- L charge, in the context of a new strongly interacting sector, equally responsible for producing a pseudo-Goldstone Higgs boson.

  1. Minimal quantization of two-dimensional models with chiral anomalies

    International Nuclear Information System (INIS)

    Ilieva, N.

    1987-01-01

    Two-dimensional gauge models with chiral anomalies - ''left-handed'' QED and the chiral Schwinger model, are quantized consistently in the frames of the minimal quantization method. The choice of the cone time as a physical time for system of quantization is motivated. The well-known mass spectrum is found but with a fixed value of the regularization parameter a=2. Such a unique solution is obtained due to the strong requirement of consistency of the minimal quantization that reflects in the physically motivated choice of the time axis

  2. Simple recipe for holographic Weyl anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Bugini, F. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción,Casilla 160-C, Concepción (Chile); Diaz, D.E. [Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andres Bello,Autopista Concepción-Talcahuano 7100, Talcahuano (Chile)

    2017-04-20

    We propose a recipe — arguably the simplest — to compute the holographic type-B Weyl anomaly for general higher-derivative gravity in asymptotically AdS spacetimes. In 5 and 7 dimensions we identify a suitable basis of curvature invariants that allows to read off easily, without any further computation, the Weyl anomaly coefficients of the dual CFT. We tabulate the contributions from quadratic, cubic and quartic purely algebraic curvature invariants and also from terms involving derivatives of the curvature. We provide few examples, where the anomaly coefficients have been obtained by other means, to illustrate the effectiveness of our prescription.

  3. Praenatalt diagnosticeret hydronefrose og andre urologiske anomalier

    DEFF Research Database (Denmark)

    Cortes, Dina; Jørgensen, Troels Munch; Rittig, Søren

    2006-01-01

    By renal ultrasound examination, urological anomalies may be demonstrated in 1-2% of fetuses and in about 0.5% of newborns. Boys have about twice the frequency of girls. Surgical treatment is indicated in about one fourth of these urological anomalies. If all pregnant women in Denmark were to have...... fetal ultrasound examination of the kidneys and the urinary tract, about 70 children would be born each year with a prenatally diagnosed urological anomaly for which surgical procedure is or will be indicated. This paper provides Danish guidelines for prenatal diagnosis, follow-up and intervention...

  4. Hybrid anomaly-gravity mediation with flavor

    International Nuclear Information System (INIS)

    Gross, Christian

    2011-01-01

    We study models with contributions of similar size to the soft masses from anomaly-and gravity mediation, thereby curing the tachyonic slepton problem of anomaly mediation. A possible origin of this hybrid setup in a 5-dimensional brane world is briefly discussed. The absence of excessive flavor violation is explained by alignment. The gravitino can be heavy enough so that the gravitino problem of supersymmetric theories with leptogenesis is avoided. The model has a characteristic signature: It predicts the distinctive gaugino mass pattern of anomaly mediation and, at the same time, O(1) slepton mass splittings.

  5. Using EVT for Geological Anomaly Design and Its Application in Identifying Anomalies in Mining Areas

    Directory of Open Access Journals (Sweden)

    Feilong Qin

    2016-01-01

    Full Text Available A geological anomaly is the basis of mineral deposit prediction. Through the study of the knowledge and characteristics of geological anomalies, the category of extreme value theory (EVT to which a geological anomaly belongs can be determined. Associating the principle of the EVT and ensuring the methods of the shape parameter and scale parameter for the generalized Pareto distribution (GPD, the methods to select the threshold of the GPD can be studied. This paper designs a new algorithm called the EVT model of geological anomaly. These study data on Cu and Au originate from 26 exploration lines of the Jiguanzui Cu-Au mining area in Hubei, China. The proposed EVT model of the geological anomaly is applied to identify anomalies in the Jiguanzui Cu-Au mining area. The results show that the model can effectively identify the geological anomaly region of Cu and Au. The anomaly region of Cu and Au is consistent with the range of ore bodies of actual engineering exploration. Therefore, the EVT model of the geological anomaly can effectively identify anomalies, and it has a high indicating function with respect to ore prospecting.

  6. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  7. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  8. Deconstruction and reconstruction of an anomaly

    Czech Academy of Sciences Publication Activity Database

    Engelmann, Dirk; Strobel, M.

    2012-01-01

    Roč. 76, č. 2 (2012), s. 678-689 ISSN 0899-8256 Institutional support: RVO:67985998 Keywords : anomalies * false consensus * information processing Subject RIV: AH - Economics Impact factor: 1.000, year: 2012

  9. Quantum anomalies in nodal line semimetals

    Science.gov (United States)

    Burkov, A. A.

    2018-04-01

    Topological semimetals are a new class of condensed matter systems with nontrivial electronic structure topology. Their unusual observable properties may often be understood in terms of quantum anomalies. In particular, Weyl and Dirac semimetals, which have point band-touching nodes, are characterized by the chiral anomaly, which leads to the Fermi arc surface states, anomalous Hall effect, negative longitudinal magnetoresistance, and planar Hall effect. In this paper, we explore analogous phenomena in nodal line semimetals. We demonstrate that such semimetals realize a three-dimensional analog of the parity anomaly, which is a known property of two-dimensional Dirac semimetals arising, for example, on the surface of a three-dimensional topological insulator. We relate one of the characteristic properties of nodal line semimetals, namely, the drumhead surface states, to this anomaly, and derive the field theory, which encodes the corresponding anomalous response.

  10. Mexico Terrain Corrected Free Air Anomalies (97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' gravity anomaly grid for Mexico, North-Central America and the Western Caribbean Sea is NOT the input data set used in the development of the MEXICO97 model....

  11. SEG US Bouguer Gravity Anomaly Grid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SEG gravity data are the product of the ad hoc Gravity Anomaly Map (GAM) Committee, sponsored by the Society of Exploration Geophysicists (SEG) and the U.S....

  12. Comparison of Unsupervised Anomaly Detection Methods

    Data.gov (United States)

    National Aeronautics and Space Administration — Several different unsupervised anomaly detection algorithms have been applied to Space Shuttle Main Engine (SSME) data to serve the purpose of developing a...

  13. Major congenital anomalies in a Danish region

    DEFF Research Database (Denmark)

    Garne, Ester; Hansen, Anne Vinkel; Birkelund, Anne Sofie

    2014-01-01

    : diabetes, epilepsy, mental disorder, thyroid disease, asthma, or inflammatory bowel disease. Medication for these conditions accounted for 46% of maternal drug use. CONCLUSION: Maternal morbidity and use of potentially teratogenic medication have increased among congenital anomaly cases. Foetal and infant...

  14. Ionospheric Anomaly before Kyushu|Japan Earthquake

    Directory of Open Access Journals (Sweden)

    YANG Li

    2017-05-01

    Full Text Available GIM data released by IGS is used in the article and a new method of combining the Sliding Time Window Method and the Ionospheric TEC correlation analysis method of adjacent grid points is proposed to study the relationship between pre-earthquake ionospheric anomalies and earthquake. By analyzing the abnormal change of TEC in the 5 grid points around the seismic region, the abnormal change of ionospheric TEC is found before the earthquake and the correlation between the TEC sequences of lattice points is significantly affected by earthquake. Based on the analysis of the spatial distribution of TEC anomaly, anomalies of 6 h, 12 h and 6 h were found near the epicenter three days before the earthquake. Finally, ionospheric tomographic technology is used to do tomographic inversion on electron density. And the distribution of the electron density in the ionospheric anomaly is further analyzed.

  15. Magnetic anomalies in Central Bengal fan

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Lakshminarayana, S.; Sarma, K.V.L.N.S.

    Total magnetic field anomalies recorded over the Central Bengal Fan are analysed and the depths to the magnetic basement are computed using the analytical signal and the Werner deconvolution methods. To the west and east of 85 degrees E...

  16. Quantum machine learning for quantum anomaly detection

    Science.gov (United States)

    Liu, Nana; Rebentrost, Patrick

    2018-04-01

    Anomaly detection is used for identifying data that deviate from "normal" data patterns. Its usage on classical data finds diverse applications in many important areas such as finance, fraud detection, medical diagnoses, data cleaning, and surveillance. With the advent of quantum technologies, anomaly detection of quantum data, in the form of quantum states, may become an important component of quantum applications. Machine-learning algorithms are playing pivotal roles in anomaly detection using classical data. Two widely used algorithms are the kernel principal component analysis and the one-class support vector machine. We find corresponding quantum algorithms to detect anomalies in quantum states. We show that these two quantum algorithms can be performed using resources that are logarithmic in the dimensionality of quantum states. For pure quantum states, these resources can also be logarithmic in the number of quantum states used for training the machine-learning algorithm. This makes these algorithms potentially applicable to big quantum data applications.

  17. Conventional Chromosome Analysis of Fetuses with Central Nervous System Anomalies and Associated Anomalies: Is Anything Changed?

    Directory of Open Access Journals (Sweden)

    Emre Ekmekci

    2018-02-01

    Full Text Available Central nervous system (CNS abnormalities are often isolated but can accompany various genetic syndromes. In this study, we evaluated conventional karyotype results and associated findings of fetuses that were diagnosed with CNS abnormalities. Cases included in the study were diagnosed with fetal CNS anomalies and underwent conventional karyotyping. Conventional karyotype results of subjects were compared with karyotype results of fetal karyotyped patients as a result of maternal anxiety in a two-year period. In this period, 69 patients were diagnosed with fetal CNS anomalies and 64 of them underwent invasive fetal karyotyping. Of these, 32 patients had isolated CNS anomalies, while 32 were associated with other anomalies. There was no significant difference between karyotype results when compared with the control group (p = 0.76. Apart from some specific anomalies, the aneuploidy rate does not significantly differ between fetuses with CNS anomalies and the control group. Advanced genetic evaluation may provide additional diagnostic benefits, especially for this group.

  18. Conventional Chromosome Analysis of Fetuses with Central Nervous System Anomalies and Associated Anomalies: Is Anything Changed?

    Science.gov (United States)

    Ekmekci, Emre; Demirel, Emine; Gencdal, Servet

    2018-02-06

    Central nervous system (CNS) abnormalities are often isolated but can accompany various genetic syndromes. In this study, we evaluated conventional karyotype results and associated findings of fetuses that were diagnosed with CNS abnormalities. Cases included in the study were diagnosed with fetal CNS anomalies and underwent conventional karyotyping. Conventional karyotype results of subjects were compared with karyotype results of fetal karyotyped patients as a result of maternal anxiety in a two-year period. In this period, 69 patients were diagnosed with fetal CNS anomalies and 64 of them underwent invasive fetal karyotyping. Of these, 32 patients had isolated CNS anomalies, while 32 were associated with other anomalies. There was no significant difference between karyotype results when compared with the control group ( p = 0.76). Apart from some specific anomalies, the aneuploidy rate does not significantly differ between fetuses with CNS anomalies and the control group. Advanced genetic evaluation may provide additional diagnostic benefits, especially for this group.

  19. Understanding water's anomalies with locally favored structures

    OpenAIRE

    Russo, John; Tanaka, Hajime

    2013-01-01

    Water is a complex structured liquid of hydrogen-bonded molecules that displays a surprising array of unusual properties, also known as water anomalies, the most famous being the density maximum at about $4^\\circ$C. The origin of these anomalies is still a matter of debate, and so far a quantitative description of water's phase behavior starting from the molecular arrangements is still missing. Here we provide a simple physical description from microscopic data obtained through computer simul...

  20. Anomalies hematologiques au cours des accidents vasculaires ...

    African Journals Online (AJOL)

    Introduction: En Côte d'Ivoire, les accidents vasculaires cérébraux (AVC) sont de plus en plus fréquents. Les anomalies biochimiques sont décrites au cours de ces pathologies. Cependant une composante hématologique est de plus en plus évoquée. L'objectif de cette étude a été de rapporter les anomalies ...

  1. An exceptional combination of congenital coronary anomalies.

    Science.gov (United States)

    Kharrat, Ilyes; El-Fassy, Eric; Amabile, Nicolas

    2012-01-01

    We present a case of congenital coronary artery anomalies combining the absence of the circumflex artery, ectopic origins of left anterior descending and diagonal arteries and abnormal courses of these vessels. These rare anomalies were detected during an elective coronary angiography in a patient with stable angina that was related to significant stenosis of the posterolateral and middle right coronary artery. A computed tomography scanner with three-dimensional reconstructions confirmed the anatomy. Copyright © 2011 Wiley Periodicals, Inc.

  2. Hybrid anomaly-gravity mediation with flavor

    OpenAIRE

    Gross, Christian

    2011-01-01

    We study models with contributions of similar size to the soft masses from anomaly- and gravity mediation, thereby curing the tachyonic slepton problem of anomaly mediation. A possible origin of this hybrid setup in a 5-dimensional brane world is briefly discussed. The absence of excessive flavor violation is explained by alignment. The gravitino can be heavy enough so that the gravitino problem of supersymmetric theories with leptogenesis is avoided. The model has a characteristic signature:...

  3. Medical imaging for congenital anomalies of the lung. Focused on tracheobronchial and parenchymal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Kohda, Ehiichi; Shiraga, Nobuyuki; Higuchi, Mutsumi; Ishibashi, Ryouchi [Tachikawa Hospital, Tokyo (Japan)

    2003-02-01

    This is a review of medical imaging studies for congenital anomalies of the lung focused on tracheobronchial and parenchymal anomalies. It is important to know the findings of these developmental anomalies, because they are frequently manifested as infectious diseases or mass. Documented details are pulmonary agenesis, aplasia, pulmonary hypoplasia, tracheal agenesis, bridging bronchus, tracheal bronchus, congenital tracheal stenosis, bronchial atresia, bronchobiliary fistula, bronchogenic cyst, bronchopulmonary sequestration, congenital cystic adenomatoid malformation, and pulmonary lymphangiectasia. (author)

  4. High salinity anomalies south of Oahu, Hawaii

    Science.gov (United States)

    Pearson, K.; Carter, G. S.

    2013-12-01

    Patches of higher salinity water were observed, using Seaglider data, in the upper 50m of the water-column between Oahu and Penguin Bank. These anomalies occur approximately once a month, and are visible in the glider data for an average of 3 days. Anomalies have abrupt transitions occurring over mere hours. Salinity within the patches can reach values in excess of 35.2 psu, 0.3 higher than the average profile for the region. The salinity signature associated with the anomalies corresponds to Subtropical surface water, found north of the Hawaiian island chain. The high salinity water is trapped by the thermocline in the mixed layer. Seasonal variations of the anomaly depth are directly related to the seasonal variations of mixed layer depth. These patches of high salinity coincide with the presence of eddies. Using sea surface height as an indicator, we found that eddy-eddy interaction and eddy-island interaction dictate the advection of upwelled waters into the region. Infrequently, we observe corresponding temperature anomalies. The larger the distance between the center of the eddy and the glider, the less visible the temperature anomaly. Positive (negative) values indicate salinity above (below) the mean profile.

  5. Coronary artery anomalies in Turner Syndrome.

    Science.gov (United States)

    Viuff, Mette H; Trolle, Christian; Wen, Jan; Jensen, Jesper M; Nørgaard, Bjarne L; Gutmark, Ephraim J; Gutmark-Little, Iris; Mortensen, Kristian H; Gravholt, Claus Højbjerg; Andersen, Niels H

    Congenital heart disease, primarily involving the left-sided structures, is often seen in patients with Turner Syndrome. Moreover, a few case reports have indicated that coronary anomalies may be more prevalent in Turner Syndrome than in the normal population. We therefore set out to systematically investigate coronary arterial anatomy by computed tomographic coronary angiography (coronary CTA) in Turner Syndrome patients. Fifty consecutive women with Turner Syndrome (mean age 47 years [17-71]) underwent coronary CTA. Patients were compared with 25 gender-matched controls. Coronary anomaly was more frequent in patients with Turner Syndrome than in healthy controls [20% vs. 4% (p = 0.043)]. Nine out of ten abnormal cases had an anomalous left coronary artery anatomy (absent left main trunk, n = 7; circumflex artery originating from the right aortic sinus, n = 2). One case had a tubular origin of the right coronary artery above the aortic sinus. There was no correlation between the presence of coronary arterial anomalies and karyotype, bicuspid aortic valve, or other congenital heart defects. Coronary anomalies are highly prevalent in Turner Syndrome. The left coronary artery is predominantly affected, with an absent left main coronary artery being the most common anomaly. No hemodynamically relevant coronary anomalies were found. Copyright © 2016 Society of Cardiovascular Computed Tomography. All rights reserved.

  6. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  7. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  8. Clustering and Recurring Anomaly Identification: Recurring Anomaly Detection System (ReADS)

    Science.gov (United States)

    McIntosh, Dawn

    2006-01-01

    This viewgraph presentation reviews the Recurring Anomaly Detection System (ReADS). The Recurring Anomaly Detection System is a tool to analyze text reports, such as aviation reports and maintenance records: (1) Text clustering algorithms group large quantities of reports and documents; Reduces human error and fatigue (2) Identifies interconnected reports; Automates the discovery of possible recurring anomalies; (3) Provides a visualization of the clusters and recurring anomalies We have illustrated our techniques on data from Shuttle and ISS discrepancy reports, as well as ASRS data. ReADS has been integrated with a secure online search

  9. An Optimized Method to Detect BDS Satellites' Orbit Maneuvering and Anomalies in Real-Time.

    Science.gov (United States)

    Huang, Guanwen; Qin, Zhiwei; Zhang, Qin; Wang, Le; Yan, Xingyuan; Wang, Xiaolei

    2018-02-28

    The orbital maneuvers of Global Navigation Satellite System (GNSS) Constellations will decrease the performance and accuracy of positioning, navigation, and timing (PNT). Because satellites in the Chinese BeiDou Navigation Satellite System (BDS) are in Geostationary Orbit (GEO) and Inclined Geosynchronous Orbit (IGSO), maneuvers occur more frequently. Also, the precise start moment of the BDS satellites' orbit maneuvering cannot be obtained by common users. This paper presented an improved real-time detecting method for BDS satellites' orbit maneuvering and anomalies with higher timeliness and higher accuracy. The main contributions to this improvement are as follows: (1) instead of the previous two-steps method, a new one-step method with higher accuracy is proposed to determine the start moment and the pseudo random noise code (PRN) of the satellite orbit maneuvering in that time; (2) BDS Medium Earth Orbit (MEO) orbital maneuvers are firstly detected according to the proposed selection strategy for the stations; and (3) the classified non-maneuvering anomalies are detected by a new median robust method using the weak anomaly detection factor and the strong anomaly detection factor. The data from the Multi-GNSS Experiment (MGEX) in 2017 was used for experimental analysis. The experimental results and analysis showed that the start moment of orbital maneuvers and the period of non-maneuver anomalies can be determined more accurately in real-time. When orbital maneuvers and anomalies occur, the proposed method improved the data utilization for 91 and 95 min in 2017.

  10. Estimating Antarctic near-surface magnetic anomalies from Oersted and CHAMP satellite magnetometer observations

    Science.gov (United States)

    von Frese, R. R.; Kim, H.; Gaya-Pique, L. R.; Taylor, P. T.; Golynsky, A. V.; Kim, J.

    2004-12-01

    Significant improvement in predicting near-surface magnetic anomalies can result from the highly accurate magnetic observations of the CHAMP satellite that is orbiting at about 400 km altitude. In general, regional magnetic signals of the crust are strongly masked by the core field and its secular variations due to wavelength coupling in the spherical harmonic representation and thus are difficult to isolate in the satellite measurements. However, efforts to isolate the regional lithospheric from core field components can exploit the correlations between the CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations. In addition, we can use spectral correlation theory to filter the static lithospheric field components from the dynamic external field effects. Employing these procedures, we processed the CHAMP magnetic observations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Oersted and noisier Magsat observations, CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intra-crustal magnetic features and crustal thickness variations of the Antarctic. Moreover, these results greatly facilitate predicting magnetic anomalies in the regional coverage gaps of the ADMAP compilation of Antarctic magnetic anomalies from shipborne, airborne and ground surveys. Our analysis suggests that considerable new insights on the magnetic properties of the lithosphere may be revealed by a further order-of-magnitude improvement in the accuracy of the magnetometer measurements at minimum orbital altitude.

  11. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  12. On the impact of an offshore bathymetric anomaly on surf zone rip channels

    NARCIS (Netherlands)

    Castelle, B.; Marieu, V.; Coco, G.; Bonneton, P.; Bruneau, N.; Ruessink, B.G.

    We use a nonlinear morphodynamic model to demonstrate that the presence of a single persistent offshore bathymetric anomaly strongly affects the formation, nonlinear evolution and saturation of surf zone rip channels. In the case of an offshore bump or trough and waves with oblique incidence, a

  13. Effects of a child with a craniofacial anomaly on stability of the parental relationship.

    Science.gov (United States)

    St John, Dane; Pai, Lori; Belfer, Myron L; Mulliken, John B

    2003-09-01

    The purpose of this study was to determine rates of divorce in parents of children with various types of craniofacial anomalies and to analyze possible confounding factors. A 29-question survey was sent to parents of all children evaluated in the Craniofacial Centre between 1992 and 1997. Parents were questioned regarding pre- and postnatal marital stability, whether the child's facial anomaly contributed to divorce, and involvement in the child's welfare. Using deformational posterior plagiocephaly as a control group, rates of divorce vs. non-divorce were compared for craniofacial anomalies, categorized as asymmetric (hemifacial microsomia, unilateral coronal synostosis, cleft lip, cleft lip/palate) or symmetric (syndromic-craniosynostosis, orbital hypertelorism, Treacher Collins syndrome). Major anomalies (hemifacial microsomia, craniosynostosis, orbital hypertelorism, Treacher Collins syndrome) were also compared to minor anomalies (cleft lip, cleft lip/palate). Surveys were sent to both parents in 412 families; 403 surveys were returned; and the results were evaluated in 275 families (67%). Frequency analysis demonstrated an overall divorce rate of 6.8% and 4.9% separation. Anomalies associated with the highest rate of divorce were hemifacial microsomia (24.0%), syndromic craniosynostosis (12.2%), and cleft lip/palate (6.8%). 79% of non-divorced couples reported a strong prenatal relationship, whereas 59% of divorced couples reported a problematic relationship. Following birth of the affected child, 47% of non-divorced couples responded that the bonds became stronger and 41% of divorced couples thought the relationship worsened. Two-sided Fisher exact test comparing control vs. all other anomalies showed significance (p=.030) for rates of divorce. Separation of anomalies into asymmetric vs. symmetric and major vs. minor categories demonstrated no significant difference in divorce rate (p>.05). The mother was more likely to become a child's primary caregiver

  14. Gravity and geothermal anomalies in Borno Basin, Nigeria ...

    African Journals Online (AJOL)

    Some prominent geothermal anomalies are found occurring in association with gravity anomalies in the Borno basin. Similar gravity anomalies also occur in the Benue and Niger (Nupe) basins. Both the geothermal and gravity anomalies of Borno basin are trending NW-SE similar to the Niger (Nupe) basin, while the Benue ...

  15. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  16. Explanation of the nature of stripe magnetic anomalies without inversions

    Science.gov (United States)

    Melikhov, Vjacheslav; Lygin, Ivan; Sokolova, Tatiana

    2014-05-01

    Several scientists of different branches express doubts on the validity of the Earth's geomagnetic field inversions hypothesis [Vine F.J., Matthews D.H, 1963]. Presently a lot of information allows to link the appearance of stripe magnetic anomalies of both signs with the spreading fracture structure (horizontal segmentation of intrusions and sills, breaks in the strong crust, vertical movements of blocks), remagnetization near the borders of the blocks, hydrothermal activity. Non-inversion mechanism of origin of linear stripe magnetic anomalies in the oceans could be explained as follows. Ascending asthenospheric flows have been enrich with volatile components, become thinner, pressure on the walls of the lithospheric plates grows and part them. When it approaches the surface: - horizontal tensile pressure grows, - lithostatic pressure in the vertical column of rocks decreases, - crust strong upper layer flakes away and begins to move horizontally. It is important that thin magmatic and magnetic layers (further layers) of the newly formed strong upper crust move away from the ridge axis. The structure of such layers forms by horizontal stresses and so consist of the hills and depressions sequences or updiped and downdiped blocks heaped each other. This layer is the main source of the magnetic field and cannot be approximated by a horizontal homogeneous plate as it proved before. In the mid-ocean ridges (MOR) the folding periods of layer depend on its thickness and rigidity and horizontal velocity of spreading. The higher velocity - the longer periods of roughness are and contrary. Same pattern is observed for the stripe magnetic anomalies distribution. The magnetic field of the MOR forms there due to young lava flows which get thermoremanent magnetization according the current direction of geomagnetic field. Partial destruction of the relief, overlaying and creation of the new shapes occur when new magma penetrates the moved magnetic layer. The process entails

  17. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  18. Dental Anomalies in a Brazilian Cleft Population.

    Science.gov (United States)

    Sá, Jamile; Mariano, Lorena C; Canguçu, Daiane; Coutinho, Thaynara S L; Hoshi, Ryuichi; Medrado, Alena Peixoto; Martelli-Junior, Hercílio; Coletta, Ricardo D; Reis, Silvia R A

    2016-11-01

      The aim of this study was to radiographically investigate the prevalence of dental anomalies outside the cleft area in a group of Brazilian patients with nonsyndromic cleft lip and/or palate (NSCL/P).   A retrospective analysis of 207 panoramic radiographs of patients with NSCL/P aged 12 to 45 years without history of tooth extraction and orthodontic treatment was performed.   Dental anomalies were found in 75.4% of the patients, and tooth agenesis (29.2%) and supernumerary tooth (2.6%) were the most common anomalies. The risk of agenesis was higher among the individuals with cleft palate (CP) compared with individuals with cleft lip (CL) and cleft lip and palate (CLP) (agenesis: CP versus CL: odds ratio 6.27, 95% confidence interval 2.21-17.8, P = .0003; CP versus CLP: odds ratio 2.94; 95% confidence interval 1.27-6.81, P = .01). The frequency of dental agenesis was higher in patients with unilateral complete CLP (agenesis: P agenesis: P = .0013), complete CP (agenesis: P agenesis: P dental agenesis (P dental anomalies in patients with NSCL/P was higher than that reported in overall population. This study found preferential associations between dental anomalies and specific extensions of NSCL/P, suggesting that dental agenesis and ectopic tooth may be part of oral cleft subphenotypes.

  19. [Vascular anomalies in the neonatal period].

    Science.gov (United States)

    Bejarano, M; Vicario, F; Soria, A; Parri, F J; Albert, A

    2017-07-20

    Vascular anomalies in the neonatal period are a diagnostic challenge for the lack of evident signs, symptoms and follow-up, and the convenience of restricting aggressive diagnostic tests. The aim of this work is to review the characteristics of neonatal cases presented to our Vascular Anomalies Unit in the last 5 years. All cases of suspected vascular anomaly presented to our unit before 1 month of age between 2010 and 2015 were reviewed, diagnostic tests and treatments carried out with chronology were analyzed. Presumptive diagnosis and final diagnosis (when available) were compared. Fifteen vascular tumors were found, 2 with visceral involvement: 6 infantile hemangiomas (IH), 3 NICH, 4 RICH, 1 tufted hemangioma, 1 unspecified liver vascular tumor, 3 venous malformations (2 equivocal MRI and a hyperkeratotic venous malformation), 4 lymphatic malformations, 3 of them macrocystic, and 2 vascular lesions that were diagnosed of fibrosarcoma and sclerema neonatorum and they were not vascular anomalies. Only 3 patients with macrocystic lymphatic malformations had prenatal diagnosis. Accurate diagnosis of vascular anomalies during the first month of life is difficult, even with MRI. Only in a few cases early treatment is needed, so it is worth taking time to follow-up. Different types of treatment (observation, propranolol, biopsy, laser, embolization, and resection) will depend on the condition to be treated. A continuous observation can avoid unnecessary procedures and risks.

  20. HYPERSPECTRAL ANOMALY DETECTION IN URBAN SCENARIOS

    Directory of Open Access Journals (Sweden)

    J. G. Rejas Ayuga

    2016-06-01

    Full Text Available We have studied the spectral features of reflectance and emissivity in the pattern recognition of urban materials in several single hyperspectral scenes through a comparative analysis of anomaly detection methods and their relationship with city surfaces with the aim to improve information extraction processes. Spectral ranges of the visible-near infrared (VNIR, shortwave infrared (SWIR and thermal infrared (TIR from hyperspectral data cubes of AHS sensor and HyMAP and MASTER of two cities, Alcalá de Henares (Spain and San José (Costa Rica respectively, have been used. In this research it is assumed no prior knowledge of the targets, thus, the pixels are automatically separated according to their spectral information, significantly differentiated with respect to a background, either globally for the full scene, or locally by image segmentation. Several experiments on urban scenarios and semi-urban have been designed, analyzing the behaviour of the standard RX anomaly detector and different methods based on subspace, image projection and segmentation-based anomaly detection methods. A new technique for anomaly detection in hyperspectral data called DATB (Detector of Anomalies from Thermal Background based on dimensionality reduction by projecting targets with unknown spectral signatures to a background calculated from thermal spectrum wavelengths is presented. First results and their consequences in non-supervised classification and extraction information processes are discussed.

  1. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  2. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  3. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  4. Origin of the Eastern Galicia Magnetic Anomaly (NW Spain). Implications for the Origin of Magnetic Anomalies in the Central Iberian Arc

    Science.gov (United States)

    Ayarza, P.; Martinez-Catalan, J. R.; Villalain, J. J.; Alvarez Lobato, F.; Martin Paramio, M.; Rodriguez Gómez, S.; Sanz López, M.

    2015-12-01

    The aeromagnetic map of Iberia features outstanding anomalies that have been key to define the Central Iberian Arc, a late-orogenic orocline in the western part of the Variscan belt. The most studied of them is the EGMA (Eastern Galicia Magnetic Anomaly), which follows the Lugo-Sanabria extensional dome and is probably associated with it. Among the existing models of this anomaly, those relating it with magnetite-rich inhomogeneous granites and migmatites formed during late-Variscan extension seem to be more plausible ones. However, this and other interpretations involving deep-seated mafic/ultramafic bodies lack resolution as they are based on the aeromagnetic dataset. New ground magnetic data have been acquired in the northern part of the Xistral Tectonic Window, at the core of the Lugo dome where its deepest rocks crop out. The resulting maps show that the anomaly ranges ~1000 nT (vs. 190 nT on the aeromagnetic map) and that the most important maxima lie on top of extensional detachments located on high-grade metasediments or inhomogeneous granites. 2D forward modeling indicates that the magnetization is carried by upper Neoproterozoic and early Cambrian metasediments, partially melted during late-Variscan high-T and low-P metamorphic event linked to the extensional collapse. Furthermore, the anomaly maxima are spatially related with detachments, where the metasediments were strongly sheared. Therefore, the P-T, redox and fluid pressure conditions necessary for the formation of magnetite seem related with the extensional process and the dynamics of its structures. Many magnetic anomalies of the Central Iberian Arc lie on top of Variscan extensional domes and accordingly may have a similar origin. Special attention is paid to the Gredos Magnetic Anomaly, coincident with the batholith of the same name. Preliminary magnetic mapping and modeling indicate that the anomaly is previous to the intrusion of the Jurassic Alentejo-Plasencia dyke and to the tardi

  5. Classification automatique d'anomalies du trafic

    OpenAIRE

    Owezarski, Philippe; Fernandes, Guilherme

    2009-01-01

    National audience; La détection d'anomalies dans le trafic réseau et leur caractérisation est un sujet d'importance depuis de nombreuses années. Une gestion efficace de grands réseaux dépend clairement de la capacité à identifier et limiter l'effet de ces anomalies. En particulier, les anomalies causées par une attaque de déni de service par inondation ont un très fort impact sur la qualité de service des réseaux, même lorsque les liens sont largement surdimensionnés et pas saturés par ces at...

  6. Gauge Anomalies and Neutrino Seesaw Models

    CERN Document Server

    Neves Cebola, Luis Manuel

    Despite the success of the Standard Model concerning theoretical predictions, there are several experimental results that cannot be explained and there are reasons to believe that there exists new physics beyond it. Neutrino oscillations, and hence their masses, are examples of this. Experimentally it is known that neutrinos masses are quite small, when compared to all Standard Model particle masses. Among the theoretical possibilities to explain these tiny masses, the seesaw mechanism is a simple and well-motivated framework. In its minimal version, heavy particles are introduced that decouple from the theory in the early universe. To build consistent theories, classical symmetries need to be preserved at quantum level, so that there are no anomalies. The cancellation of these anomalies leads to constraints in the parameters of the theory. One attractive solution is to realize the anomaly cancellation through the modication of the gauge symmetry. In this thesis we present a short review of some features of t...

  7. Detecting data anomalies methods in distributed systems

    Science.gov (United States)

    Mosiej, Lukasz

    2009-06-01

    Distributed systems became most popular systems in big companies. Nowadays many telecommunications companies want to hold large volumes of data about all customers. Obviously, those data cannot be stored in single database because of many technical difficulties, such as data access efficiency, security reasons, etc. On the other hand there is no need to hold all data in one place, because companies already have dedicated systems to perform specific tasks. In the distributed systems there is a redundancy of data and each system holds only interesting data in appropriate form. Data updated in one system should be also updated in the rest of systems, which hold that data. There are technical problems to update those data in all systems in transactional way. This article is about data anomalies in distributed systems. Avail data anomalies detection methods are shown. Furthermore, a new initial concept of new data anomalies detection methods is described on the last section.

  8. Anomaly-based Network Intrusion Detection Methods

    Directory of Open Access Journals (Sweden)

    Pavel Nevlud

    2013-01-01

    Full Text Available The article deals with detection of network anomalies. Network anomalies include everything that is quite different from the normal operation. For detection of anomalies were used machine learning systems. Machine learning can be considered as a support or a limited type of artificial intelligence. A machine learning system usually starts with some knowledge and a corresponding knowledge organization so that it can interpret, analyse, and test the knowledge acquired. There are several machine learning techniques available. We tested Decision tree learning and Bayesian networks. The open source data-mining framework WEKA was the tool we used for testing the classify, cluster, association algorithms and for visualization of our results. The WEKA is a collection of machine learning algorithms for data mining tasks.

  9. Associated congenital anomalies among cases with Down syndrome.

    Science.gov (United States)

    Stoll, Claude; Dott, Beatrice; Alembik, Yves; Roth, Marie-Paule

    2015-12-01

    Down syndrome (DS) is the most common congenital anomaly widely studied for at least 150 years. However, the type and the frequency of congenital anomalies associated with DS are still controversial. Despite prenatal diagnosis and elective termination of pregnancy for fetal anomalies, in Europe, from 2008 to 2012 the live birth prevalence of DS per 10,000 was 10. 2. The objectives of this study were to examine the major congenital anomalies occurring in infants and fetuses with Down syndrome. The material for this study came from 402,532 consecutive pregnancies of known outcome registered by our registry of congenital anomalies between 1979 and 2008. Four hundred sixty seven (64%) out of the 728 cases with DS registered had at least one major associated congenital anomaly. The most common associated anomalies were cardiac anomalies, 323 cases (44%), followed by digestive system anomalies, 42 cases (6%), musculoskeletal system anomalies, 35 cases (5%), urinary system anomalies, 28 cases (4%), respiratory system anomalies, 13 cases (2%), and other system anomalies, 26 cases (3.6%). Among the cases with DS with congenital heart defects, the most common cardiac anomaly was atrioventricular septal defect (30%) followed by atrial septum defect (25%), ventricular septal defect (22%), patent ductus arteriosus (5%), coarctation of aorta (5%), and tetralogy of Fallot (3%). Among the cases with DS with a digestive system anomaly recorded, duodenal atresia (67%), Hirschsprung disease (14%), and tracheo-esophageal atresia (10%) were the most common. Fourteen (2%) of the cases with DS had an obstructive anomaly of the renal pelvis, including hydronephrosis. The other most common anomalies associated with cases with DS were syndactyly, club foot, polydactyly, limb reduction, cataract, hydrocephaly, cleft palate, hypospadias and diaphragmatic hernia. Many studies to assess the anomalies associated with DS have reported various results. There is no agreement in the literature as to

  10. [Megadolichobasilar anomaly causing acute deafness with vertigo].

    Science.gov (United States)

    Unkelbach, M H; Radeloff, A; Bink, A; Gstöttner, W; Ziemann, U

    2008-01-01

    Megadolichobasilar anomaly, a dilatant arteriopathy of the basilar artery attributable to chronic arterial hypertension, can cause cranial nerve compression syndromes of the cerebellopontine angle or infarcts of the vertebrobasilar circulation. In this paper, we report on a patient with known megadolichobasilar anomaly and a partially thrombosed fusiform aneurysm of the basilar artery, who presented with acute-onset vertigo and subsequent deafness due to thromboembolic occlusion of the labyrinthine artery. Because of the vascular origin of the patient's symptoms, his vertigo disappeared over time while the deafness persisted.

  11. Comparing corrective actions with anomaly resolution

    International Nuclear Information System (INIS)

    Smith, B.W.; Harms, N.L.

    1986-01-01

    Quality control and assurance are essential to any system to safeguard nuclear materials. Formalization of quality assurance activities for safeguards under the name of quality assurance has begun at several organizations. The approach to quality assurance for safeguards differs from quality assurance for facilities and hardware both in the definition and use of the product, which is information. Anomaly resolution is comparable to corrective actions in quality assurance of a hardware product, but is also part of the product of safeguards and, therefore, has its own quality assurance. This paper reviews corrective actions as compared to anomaly resolution

  12. Congenital anomalies of the neonatal head

    International Nuclear Information System (INIS)

    Benson, C.B.; Teele, R.L.; Dobkin, G.R.; Fine, C.; Bundy, A.L.; Doubilet, P.M.

    1987-01-01

    US is a noninvasive modality that has proved highly valuable in the assessment of congenital intracranial anomalies in the neonate. The patterns of malformation must be familiar to those who obtain and interpret neonatal cranial sonograms. The authors present a variety of cases of congenital anomalies studied with US, including agenesis of the corpus callosum, Dandy-Walker malformation, occipital enecphalocele, congenital hydrocephalus, vein of Galen aneurysm, hydranencephaly, holoprosencephaly, absence of the septum pellucidum, schizencephaly, and hypoplastic cerebellum. Correlation with other radiographic modalities and pathologic follow-up, available in a majority of cases, is included

  13. Radioactive anomaly discrimination from spectral ratios

    Science.gov (United States)

    Maniscalco, James; Sjoden, Glenn; Chapman, Mac Clements

    2013-08-20

    A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

  14. Human exposure to environmental contaminants and congenital anomalies: a critical review.

    Science.gov (United States)

    Foster, Warren G; Evans, Jane A; Little, Julian; Arbour, Laura; Moore, Aideen; Sauve, Reg; Andrés León, Juan; Luo, Wei

    2017-01-01

    Congenital anomalies are an important cause of infant mortality and disability. Developmental exposure to environmental contaminants is thought to increase the risk for congenital anomalies. Herein, we describe a critical review of the literature conducted between February and March 2014 yielding 3057 references from which 97 unique relevant articles published from 2003 through 2014 were evaluated. Common congenital anomalies including hypospadias, cryptorchidism, anogenital distance (AGD), congenital heart defects and oral clefts were well represented in the literature whereas other outcomes such as neural tube defects, limb deficiency defects and gastroschisis were rarely described. While definitions used for congenital anomalies and methods of ascertainment were usually consistent across studies, inconsistencies were frequently found in grouping of different congenital heart defects. Despite strong links between some congenital anomalies and parental occupation, these studies are unable to provide clear insight into the specific chemicals responsible owing to lack of direct measures of exposure. In comparison, data are mixed for contaminant exposures at concentrations representative of results from contemporary biomonitoring studies. Of the environmental contaminants studied, the association between phthalate exposures and developmental abnormalities of the male reproductive tract received the greatest attention. Important limitations of the literature studied relate to adequacy of sample size, absence of or weaknesses in exposure assessment methodologies, failure to account for biological plausibility and grouping of congenital anomalies with divergent mechanisms. We conclude that the literature is inadequate at this time to support a conclusion that exposure to environmental contaminants are or are not associated with increased risks for congenital anomalies in the general population.

  15. Atmospheric forcing of sea ice anomalies in the Ross Sea Polynya region

    Science.gov (United States)

    Dale, Ethan; McDonald, Adrian; Rack, Wolfgang

    2016-04-01

    Despite warming trends in global temperatures, sea ice extent in the southern hemisphere has shown an increasing trend over recent decades. Wind-driven sea ice export from coastal polynyas is an important source of sea ice production. Areas of major polynyas in the Ross Sea, the region with largest increase in sea ice extent, have been suggested to produce the vast amount of the sea ice in the region. We investigate the impacts of strong wind events on polynyas and the subsequent sea ice production. We utilize Bootstrap sea ice concentration (SIC) measurements derived from satellite based, Special Sensor Microwave Imager (SSM/I) brightness temperature images. These are compared with surface wind measurements made by automatic weather stations of the University of Wisconsin-Madison Antarctic Meteorology Program. Our analysis focusses on the winter period defined as 1st April to 1st November in this study. Wind data was used to classify each day into characteristic regimes based on the change of wind speed. For each regime, a composite of SIC anomaly was formed for the Ross Sea region. We found that persistent weak winds near the edge of the Ross Ice Shelf are generally associated with positive SIC anomalies in the Ross Sea polynya area (RSP). Conversely we found negative SIC anomalies in this area during persistent strong winds. By analyzing sea ice motion vectors derived from SSM/I brightness temperatures, we find significant sea ice motion anomalies throughout the Ross Sea during strong wind events. These anomalies persist for several days after the strong wing event. Strong, negative correlations are found between SIC within the RSP and wind speed indicating that strong winds cause significant advection of sea ice in the RSP. This rapid decrease in SIC is followed by a more gradual recovery in SIC. This increase occurs on a time scale greater than the average persistence of strong wind events and the resulting Sea ice motion anomalies, highlighting the production

  16. Peters anomaly in association with multiple midline anomalies and a familial chromosome 4 inversion.

    Science.gov (United States)

    Neilan, Edward; Pikman, Yana; Kimonis, Virginia E

    2006-06-01

    We describe the clinical presentation of a boy with Peters anomaly and a cataract of the left eye in association with multiple midline defects. His extraocular developmental abnormalities include cleft lip and palate, cardiac anomalies, an atretic cranial meningocele, as well as malformation of the left ear with chronic otitis media. Genetic analysis revealed a balanced paracentric inversion of chromosome 4, inv(4)(q12q13.3), also present in his asymptomatic father and siblings. His normal stature and cognitive development distinguish this case from the Peters Plus syndrome. The presence of a cranial meningocele represents a new association with Peters anomaly.

  17. Interpretation of Ground Temperature Anomalies in Hydrothermal Discharge Areas

    Science.gov (United States)

    Price, Adam N.; Lindsey, Cary R.; Fairley, Jerry P.

    2017-12-01

    Researchers have long noted the potential for shallow hydrothermal fluids to perturb near-surface temperatures. Several investigators have made qualitative or semiquantitative use of elevated surface temperatures; for example, in snowfall calorimetry, or for tracing subsurface flow paths. However, a quantitative framework connecting surface temperature observations with conditions in the subsurface is currently lacking. Here, we model an area of shallow subsurface flow at Burgdorf Hot Springs, a rustic commercial resort in the Payette National Forest, north of McCall, ID, USA. We calibrate the model using shallow (0.2 m depth) ground temperature measurements and overburden thickness estimates from seismic refraction studies. The calibrated model predicts negligible loss of heat energy from the laterally migrating fluids at the Burgdorf site, in spite of the fact that thermal anomalies are observed in the unconsolidated near-surface alluvium. Although elevated near-surface ground temperatures are commonly assumed to result from locally high heat flux, this conflicts with the small apparent heat loss during lateral flow inferred at the Burgdorf site. We hypothesize an alternative explanation for near-surface temperature anomalies that is only weakly dependent on heat flux, and more strongly controlled by the Biot number, a dimensionless parameter that compares the rate at which convection carries heat away from the land surface to the rate at which it is supplied by conduction to the interface.

  18. The inflationary origin of the Cold Spot anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Bueno Sánchez, Juan C., E-mail: juan.c.bueno@correounivalle.edu.co [Departamento de Física, Universidad del Valle, A.A. 25360, Santiago de Cali (Colombia); Centro de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Antonio Nariño, Cra 3 Este # 47A-15, Bogotá D.C. 110231 (Colombia); Escuela de Física, Universidad Industrial de Santander, Ciudad Universitaria, Bucaramanga 680002 (Colombia); Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, 28040, Madrid (Spain)

    2014-12-12

    Single-field inflation, arguably the simplest and most compelling paradigm for the origin of our Universe, is strongly supported by the recent results of the Planck satellite and the BICEP2 experiment. The results from Planck, however, also confirm the presence of a number of anomalies in the Cosmic Microwave Background (CMB), whose origin becomes problematic in single-field inflation. Among the most prominent and well-tested of these anomalies is the Cold Spot, which constitutes the only significant deviation from Gaussianity in the CMB. Planck's non-detection of primordial non-Gaussianity on smaller scales thus suggests the existence of a physical mechanism whereby significant non-Gaussianity is generated on large angular scales only. In this Letter, we address this question by developing a localized version of the inhomogeneous reheating scenario, which postulates the existence of a scalar field able to modify the decay of the inflaton on localized spatial regions only. We demonstrate that if the Cold Spot is due to an overdensity in the last scattering surface, the localization mechanism offers a feasible explanation for it, thus providing a physical mechanism for the generation of localized non-Gaussianity in the CMB. If, on the contrary, the Cold Spot is caused by a newly discovered supervoid (as recently claimed), we argue that the localization mechanism, while managing to enhance underdensities, may well shed light on the rarity of the discovered supervoid.

  19. Mid-latitude ionospheric scintillation anomaly in the Far East

    Directory of Open Access Journals (Sweden)

    L. A. Hajkowicz

    2003-02-01

    Full Text Available A long-term (over 3 years study has been undertaken to obtain a comprehensive evaluation of VHF ionospheric scintillation morphology in East Asia (at Kokobunji in Japan, using amplitude records from Transit satellites. It is now evident that summer day and night scintillation enhancement in this mid-latitude region is a long-term evidence of a well-known Asian ionospheric disturbance anomaly. The scintillation activity is particularly strong during summer nights (21:00–24:00 LT and on occasion, all satellite passes recorded on consecutive days are associated with pronounced scintillation activity. A second sub-maximum is observed in the summer pre-noon period (09:00–12:00 LT. The scintillation regions extend latitudinally for a distance of 400–600 km in the F-region and 100–200 km in the E-region, mostly equatorwards of Kokobunji. For comparison similar scintillation data obtained for one year at the same longitudinal sector but in southern mid-latitudes (Brisbane in Australia were compared with the simultaneous northern scintillation data. The scintillation activity at Brisbane was much less pronounced in the southern summer but was of the same low level during other seasons as that for Kokobunji. This consistent scintillation anomaly, as yet, has not been included in the global scintillation models, which are essential for radio-satellite communications.Key words. Ionosphere (mid-latitude ionosphere; ionospheric irregularities

  20. Mid-latitude ionospheric scintillation anomaly in the Far East

    Directory of Open Access Journals (Sweden)

    L. A. Hajkowicz

    Full Text Available A long-term (over 3 years study has been undertaken to obtain a comprehensive evaluation of VHF ionospheric scintillation morphology in East Asia (at Kokobunji in Japan, using amplitude records from Transit satellites. It is now evident that summer day and night scintillation enhancement in this mid-latitude region is a long-term evidence of a well-known Asian ionospheric disturbance anomaly. The scintillation activity is particularly strong during summer nights (21:00–24:00 LT and on occasion, all satellite passes recorded on consecutive days are associated with pronounced scintillation activity. A second sub-maximum is observed in the summer pre-noon period (09:00–12:00 LT. The scintillation regions extend latitudinally for a distance of 400–600 km in the F-region and 100–200 km in the E-region, mostly equatorwards of Kokobunji. For comparison similar scintillation data obtained for one year at the same longitudinal sector but in southern mid-latitudes (Brisbane in Australia were compared with the simultaneous northern scintillation data. The scintillation activity at Brisbane was much less pronounced in the southern summer but was of the same low level during other seasons as that for Kokobunji. This consistent scintillation anomaly, as yet, has not been included in the global scintillation models, which are essential for radio-satellite communications.

    Key words. Ionosphere (mid-latitude ionosphere; ionospheric irregularities

  1. The "parity" anomaly on an unorientable manifold

    Science.gov (United States)

    Witten, Edward

    2016-11-01

    The "parity" anomaly—more accurately described as an anomaly in time-reversal or reflection symmetry—arises in certain theories of fermions coupled to gauge fields and/or gravity in a spacetime of odd dimension. This anomaly has traditionally been studied on orientable manifolds only, but recent developments involving topological superconductors have made it clear that one can get more information by asking what happens on an unorientable manifold. In this paper, we give a full description of the "parity" anomaly for fermions coupled to gauge fields and gravity in 2 +1 dimensions on a possibly unorientable spacetime. We consider an application to topological superconductors and another application to M theory. The application to topological superconductors involves using knowledge of the "parity" anomaly as an ingredient in constructing gapped boundary states of these systems and in particular in gapping the boundary of a ν =16 system in a topologically trivial fashion. The application to M theory involves showing the consistency of the path integral of an M theory membrane on a possibly unorientable worldvolume. In the past, this has been done only in the orientable case.

  2. Radiographic studies on morphological anomalies in artificially ...

    African Journals Online (AJOL)

    Radiographic examination revealed anomalies such as hypoplasia and hyperplasia of fins, supernumeracry and agenesis of fins, fin cleft, and fusion of fins, scoliosis and kyphosis. The phenotypic lateral body curvatures and stump body trait were basically due to varying degrees and positions of scoliosis and thus, ...

  3. Calcium isotopic anomalies in the Allende meteorite

    International Nuclear Information System (INIS)

    Lee, T.; Papanastassiou, D.A.; Wasserburg, G.J.

    1978-01-01

    We report isotopic anomalies in Ca which were found in two Ca-Al-rich inclusions of the Allende meteorite. These inclusions previously had been shown to contain special anomalies for Mg and O which were attributed to fractionation and unknown nuclear effects. The Ca data, when corrected for mass fractionation by using 40 Ca/ 44 Ca as a standard, show nonlinear isotopic effects in 48 Ca of +13.5 per mil and in 42 Ca of +1.7 per mil for one sample. The second sample shows a 48 Ca depletion of -2.9 per mil, but all other isotopes are normal. Samples with large excesses in 26 Mg show no Ca anomalies. The effects demonstrate that isotopic anomalies exist for higher-atomic-number refractory elements in solar-system materials and do not appear to be readily explainable by a simple model. The correlation of O, Mg, and Ca results on the same inclusions requires the addition and preservation in the solar system of components from idverse nucleosynthetic sources. Observed anomalous Mg and Ca compositions for coexisting mineral phases are uniform within each inclusion, and require initial isotopic homogeneity within an inclusion but the preservation of wide variations between inclusions. Assuming formation of these inclusions by condensation from a gaseous part of the solar nebula, this implies isotopic heterogeneity on a scale of 10-10 2 km within the nebula

  4. Critical point anomalies include expansion shock waves

    NARCIS (Netherlands)

    Nannen, N.R.; Guardone, A.; Colonna, P.

    2014-01-01

    From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the

  5. Conformal transformation, gauge fields and trace anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Alves, M.S.; Barcelos-Neto, J.

    1988-02-01

    In a recent work, Padmanabhan (1985 Class. Quant. Grav. 2 4105) showed an interesting way of constructing a general conformally invariant scalar theory by introducing a conformal gauge field. We comment on the extrapolation of this idea to the fermionic field and study the trace anomaly for the scalar case by using the path integral formalism.

  6. Anomalies in radiation decays of charmed mesons

    International Nuclear Information System (INIS)

    Kalinovskij, Yu.L.; Pervushin, V.N.; Sarikov, N.A.

    1986-01-01

    The amplitudes of the charmed meson decays D→0 - +0 - +γ and F→0 - +0 - +γ are calculated in the framework of the SU(4)xSU(4)-chiral Lagrangians with account for anomalies. It is shown that in this approach no E1-transition exists

  7. Analyzing Spatiotemporal Anomalies through Interactive Visualization

    Directory of Open Access Journals (Sweden)

    Tao Zhang

    2014-06-01

    Full Text Available As we move into the big data era, data grows not just in size, but also in complexity, containing a rich set of attributes, including location and time information, such as data from mobile devices (e.g., smart phones, natural disasters (e.g., earthquake and hurricane, epidemic spread, etc. We are motivated by the rising challenge and build a visualization tool for exploring generic spatiotemporal data, i.e., records containing time location information and numeric attribute values. Since the values often evolve over time and across geographic regions, we are particularly interested in detecting and analyzing the anomalous changes over time/space. Our analytic tool is based on geographic information system and is combined with spatiotemporal data mining algorithms, as well as various data visualization techniques, such as anomaly grids and anomaly bars superimposed on the map. We study how effective the tool may guide users to find potential anomalies through demonstrating and evaluating over publicly available spatiotemporal datasets. The tool for spatiotemporal anomaly analysis and visualization is useful in many domains, such as security investigation and monitoring, situation awareness, etc.

  8. Drug safety in pregnancy - monitoring congenital anomalies

    NARCIS (Netherlands)

    Morgan, Margery; De Jong-Van Den Berg, Lolkje T. W.; Jordan, Sue

    Aim This paper outlines research into the causes of congenital anomalies, and introduces a pan-European study. The potential roles of nurses and midwives in this area are illustrated by a case report. Background Since the thalidomide disaster, use of drugs in pregnancy has been carefully monitored

  9. Psychoeducational Implications of Sex Chromosome Anomalies

    Science.gov (United States)

    Wodrich, David L.; Tarbox, Jennifer

    2008-01-01

    Numerous anomalies involving the sex chromosomes (X or Y) have been documented and their impact on development, learning, and behavior studied. This article reviews three of these disorders, Turner syndrome, Klinefelter syndrome, and Lesch-Nyhan disease. Each of these three is associated with one or more selective impairments or behavioral…

  10. Supercurrent anomalies in 4d SCFTs

    Science.gov (United States)

    Papadimitriou, Ioannis

    2017-07-01

    We use holographic renormalization of minimal N=2 gauged supergravity in order to derive the general form of the quantum Ward identities for 3d N=2 and 4d N=1 superconformal theories on general curved backgrounds, including an arbitrary fermionic source for the supercurrent. The Ward identities for 4d N=1 theories contain both bosonic and fermionic global anomalies, which we determine explicitly up to quadratic order in the supercurrent source. The Ward identities we derive apply to any superconformal theory, independently of whether it admits a holographic dual, except for the specific values of the a and c anomaly coefficients, which are equal due to our starting point of a two-derivative bulk supergravity theory. We show that the fermionic anomalies lead to an anomalous transformation of the supercurrent under rigid supersymmetry on backgrounds admitting Killing spinors, even if all superconformal anomalies are numerically zero on such backgrounds. The anomalous transformation of the supercurrent under rigid supersymmetry leads to an obstruction to the Q-exactness of the stress tensor in supersymmetric vacua, and may have implications for the applicability of localization techniques. We use this obstruction to the Q-exactness of the stress tensor, together with the Ward identities, in order to determine the general form of the stress tensor and R-current one-point functions in supersymmetric vacua, which allows us to obtain general expressions for the supersymmetric Casimir charges and partition function.

  11. Frequency Characteristics of Geomagnetic Induction Anomalies in ...

    Indian Academy of Sciences (India)

    19

    Res., 98, 15967–15985. Gombos A. M et al 1995 The tectonic evolution of western India and its impacts on hydrocarbon occurrences; on overview; Sediment.Geol.,96, 119-129. Ingham M. R., Bhingam D. K. and Gough D.I 1983 Magnetovariational study of a geothermal anomaly; Geophys. J. R. Astron. Soc., 72, 597-618.

  12. Detection of cardiovascular anomalies: Hybrid systems approach

    KAUST Repository

    Ledezma, Fernando

    2012-06-06

    In this paper, we propose a hybrid interpretation of the cardiovascular system. Based on a model proposed by Simaan et al. (2009), we study the problem of detecting cardiovascular anomalies that can be caused by variations in some physiological parameters, using an observerbased approach. We present the first numerical results obtained. © 2012 IFAC.

  13. Congenital spine anomalies: the closed spinal dysraphisms

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Erin Simon [University of Pennsylvania, Department of Radiology, The Children' s Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA (United States); Rossi, Andrea [G. Gaslini Children' s Hospital, Department of Radiology, Genoa (Italy)

    2015-09-15

    The term congenital spinal anomalies encompasses a wide variety of dysmorphology that occurs during early development. Familiarity with current terminology and a practical, clinico-radiologic classification system allows the radiologist to have a more complete understanding of malformations of the spine and improves accuracy of diagnosis when these entities are encountered in practice. (orig.)

  14. Possible Waardenburg syndrome with gastrointestinal anomalies.

    OpenAIRE

    Nutman, J; Steinherz, R; Sivan, Y; Goodman, R M

    1986-01-01

    We describe a patient with possible Waardenburg syndrome associated with anal atresia and oesophageal atresia with tracheooesophageal fistula. Three other published cases with atretic gastrointestinal anomalies associated with the Waardenburg syndrome are reviewed. We conclude that the association between atretic lesions of the gastrointestinal tract and the Waardenburg syndrome may be a significant one.

  15. Possible Waardenburg syndrome with gastrointestinal anomalies.

    Science.gov (United States)

    Nutman, J; Steinherz, R; Sivan, Y; Goodman, R M

    1986-01-01

    We describe a patient with possible Waardenburg syndrome associated with anal atresia and oesophageal atresia with tracheooesophageal fistula. Three other published cases with atretic gastrointestinal anomalies associated with the Waardenburg syndrome are reviewed. We conclude that the association between atretic lesions of the gastrointestinal tract and the Waardenburg syndrome may be a significant one. Images PMID:3712396

  16. An Unsupervised Deep Hyperspectral Anomaly Detector.

    Science.gov (United States)

    Ma, Ning; Peng, Yu; Wang, Shaojun; Leong, Philip H W

    2018-02-26

    Hyperspectral image (HSI) based detection has attracted considerable attention recently in agriculture, environmental protection and military applications as different wavelengths of light can be advantageously used to discriminate different types of objects. Unfortunately, estimating the background distribution and the detection of interesting local objects is not straightforward, and anomaly detectors may give false alarms. In this paper, a Deep Belief Network (DBN) based anomaly detector is proposed. The high-level features and reconstruction errors are learned through the network in a manner which is not affected by previous background distribution assumption. To reduce contamination by local anomalies, adaptive weights are constructed from reconstruction errors and statistical information. By using the code image which is generated during the inference of DBN and modified by adaptively updated weights, a local Euclidean distance between under test pixels and their neighboring pixels is used to determine the anomaly targets. Experimental results on synthetic and recorded HSI datasets show the performance of proposed method outperforms the classic global Reed-Xiaoli detector (RXD), local RX detector (LRXD) and the-state-of-the-art Collaborative Representation detector (CRD).

  17. Congenital sixth nerve palsy with associated anomalies

    Directory of Open Access Journals (Sweden)

    Nirupama Kasturi

    2017-01-01

    Full Text Available Congenital abduction deficit is most likely due to Duane's retraction syndrome as congenital abducens nerve palsy is very rare. We report two cases of infantile abduction deficit due to sixth nerve palsy associated with other anomalies to highlight the importance of including neuroimaging in the evaluation of an infant presenting with a limitation of abduction.

  18. Congenital sixth nerve palsy with associated anomalies.

    Science.gov (United States)

    Kasturi, Nirupama

    2017-10-01

    Congenital abduction deficit is most likely due to Duane's retraction syndrome as congenital abducens nerve palsy is very rare. We report two cases of infantile abduction deficit due to sixth nerve palsy associated with other anomalies to highlight the importance of including neuroimaging in the evaluation of an infant presenting with a limitation of abduction.

  19. Vascular anomalies and retroperitoneal lymphadenectomy (RLA).

    Science.gov (United States)

    Fehér, M; Bedri, I; Böszörményi, G; Villányi, K

    1988-01-01

    In the past 7 years a total of 90 RLAs were performed in patients with testicular tumour and the vascular anomaly of the retroperitoneum was diagnosed in 10 cases. Attention is called to these vascular disorders which render the performance of lymph dissection difficult but can never influence the question of operability.

  20. Anomaly Detection using the "Isolation Forest" algorithm

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Anomaly detection can provide clues about an outlying minority class in your data: hackers in a set of network events, fraudsters in a set of credit card transactions, or exotic particles in a set of high-energy collisions. In this talk, we analyze a real dataset of breast tissue biopsies, with malignant results forming the minority class. The "Isolation Forest" algorithm finds anomalies by deliberately “overfitting” models that memorize each data point. Since outliers have more empty space around them, they take fewer steps to memorize. Intuitively, a house in the country can be identified simply as “that house out by the farm”, while a house in the city needs a longer description like “that house in Brooklyn, near Prospect Park, on Union Street, between the firehouse and the library, not far from the French restaurant”. We first use anomaly detection to find outliers in the biopsy data, then apply traditional predictive modeling to discover rules that separate anomalies from normal data...

  1. Oxygen isotopic anomaly and solar nebular photochemistry

    International Nuclear Information System (INIS)

    Kitamura, Y.; Shimizu, M.

    1983-01-01

    At the cool periphery of the solar nebula, oxygen could photochemically be formed from water. The mixing of 17 O and 18 O enriched by the self-shielding effect of 16 O 2 to the dust grain melted by the shock waves there would explain the oxygen isotopic anomaly in the high-temperature mineral of the carbonaceous meteorites. (Auth.)

  2. Experimental and phenomenological status of neutrino anomalies

    Indian Academy of Sciences (India)

    The current status of neutrino anomalies is summarized; the KamLAND experiment is described and the recent results of KamLAND presented. Author Affiliations. Sandip Pakvasa1. Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96822, USA. Pramana – Journal of Physics. Current Issue : Vol.

  3. Anomaly observed in the Pamir experiment

    International Nuclear Information System (INIS)

    Kempa, Ya.; Malinovski, Ya.

    2001-01-01

    Emulsion cloud chambers used in the Pamir experiment during many years differed both in area and in design. It enabled to analyze spatial nad angular parameters of the recorded particles in chambers of different designs. Paper contains the detected anomalies and their preliminary interpretation [ru

  4. Do retractile testes have anatomical anomalies?

    Directory of Open Access Journals (Sweden)

    Kleber M. Anderson

    Full Text Available ABSTRACT Objectives: To assess the incidence of anatomical anomalies in patients with retractile testis. Materials and Methods: We studied prospectively 20 patients (28 testes with truly retractile testis and compared them with 25 human fetuses (50 testes with testis in scrotal position. We analyzed the relations among the testis, epididymis and patency of the processus vaginalis (PV. To analyze the relations between the testis and epididymis, we used a previous classification according to epididymis attachment to the testis and the presence of epididymis atresia. To analyze the structure of the PV, we considered two situations: obliteration of the PV and patency of the PV. We used the Chi-square test for contingency analysis of the populations under study (p <0.05. Results: The fetuses ranged in age from 26 to 35 weeks post-conception (WPC and the 20 patients with retractile testis ranged in ages from 1 to 12 years (average of 5.8. Of the 50 fetal testes, we observed complete patency of the PV in 2 cases (4% and epididymal anomalies (EAs in 1 testis (2%. Of the 28 retractile testes, we observed patency of the PV in 6 cases (21.4% and EA in 4 (14.28%. When we compared the incidence of EAs and PV patency we observed a significantly higher prevalence of these anomalies in retractile testes (p=0.0116. Conclusions: Retractile testis is not a normal variant with a significant risk of patent processus vaginalis and epididymal anomalies.

  5. An Unsupervised Deep Hyperspectral Anomaly Detector

    Directory of Open Access Journals (Sweden)

    Ning Ma

    2018-02-01

    Full Text Available Hyperspectral image (HSI based detection has attracted considerable attention recently in agriculture, environmental protection and military applications as different wavelengths of light can be advantageously used to discriminate different types of objects. Unfortunately, estimating the background distribution and the detection of interesting local objects is not straightforward, and anomaly detectors may give false alarms. In this paper, a Deep Belief Network (DBN based anomaly detector is proposed. The high-level features and reconstruction errors are learned through the network in a manner which is not affected by previous background distribution assumption. To reduce contamination by local anomalies, adaptive weights are constructed from reconstruction errors and statistical information. By using the code image which is generated during the inference of DBN and modified by adaptively updated weights, a local Euclidean distance between under test pixels and their neighboring pixels is used to determine the anomaly targets. Experimental results on synthetic and recorded HSI datasets show the performance of proposed method outperforms the classic global Reed-Xiaoli detector (RXD, local RX detector (LRXD and the-state-of-the-art Collaborative Representation detector (CRD.

  6. PROBLEMA ANOMALI DALAM INITIAL PUBLIC OFFERING (IPO

    Directory of Open Access Journals (Sweden)

    Sautma Ronni Basana

    2003-01-01

    Full Text Available This study on Initial Public Offerings (IPO showed that IPO stocks on average were underpriced, underperformed in the long run aftermarket and the Hot and Cold market cycle was present. These phenomenom can be explained by among others, the following: Asymetric Information, Winner's Curse, Traditional-Ibbotson, and Signalling Equilibrium Phenomenom. However, all of these can't give a satisfactory explanation because they were based on the price which existed on the secondary market (Underpriced Theory. The Withdrawn IPO (WIPO theory tried to explain the IPO anomaly differently so that the IPO anomaly could be explained clearly. Abstract in Bahasa Indonesia : Studi tentang Penawaran Saham Perdana (IPO menunjukkan saham-saham IPO secara rata-rata mengalami Underpriced, kinerja jangka panjang yang jelek dan adanya siklus pasar "Hot" dan "Cold". Ada beberapa penjelasan terhadap fenomena tersebut, antara lain: Informasi Asimetri, WinnerCurse, Tradisional-Ibbotson, Signaling Equilibrium Phenomenom tetapi semuanya belum memuaskan karena berdasarkan pada basis harga yang ada di pasar sekunder (Teori Underpriced. Teori Withdrawn IPO (WIPO mencoba menjelaskan fenomena anomali IPO dengan cara yang berbeda sehingga fenomena anomali IPO dapat dijelaskan secara tuntas. Kata kunci: Penawaran Saham Perdana (IPO, Underpriced, Withdrawn IPO (WIPO.

  7. Trace anomaly and counterterms in designer gravity

    Energy Technology Data Exchange (ETDEWEB)

    Anabalón, Andrés [Departamento de Ciencias, Facultad de Artes Liberalesand Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Av. Padre Hurtado 750, Viña del Mar (Chile); Astefanesei, Dumitru [Instituto de Física, Pontificia Universidad Católica de Valparaíso,Casilla 4059, Valparaíso (Chile); Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,14476 Golm (Germany); Choque, David [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,14476 Golm (Germany); Universidad Técnica Federico Santa María,Av. España 1680, Valparaíso (Chile); Martínez, Cristián [Centro de Estudios Científicos (CECs),Av. Arturo Prat 514, Valdivia (Chile)

    2016-03-17

    We construct concrete counterterms of the Balasubramanian-Kraus type for Einstein-scalar theories with designer gravity boundary conditions in AdS{sub 4}, so that the total action is finite on-shell and satisfy a well defined variational principle. We focus on scalar fields with the conformal mass m{sup 2}=−2l{sup −2} and show that the holographic mass matches the Hamiltonian mass for any boundary conditions. We compute the trace anomaly of the dual field theory in the generic case, as well as when there exist logarithmic branches of non-linear origin. As expected, the anomaly vanishes for the boundary conditions that are AdS invariant. When the anomaly does not vanish, the dual stress tensor describes a thermal gas with an equation of state related to the boundary conditions of the scalar field. In the case of a vanishing anomaly, we recover the dual theory of a massless thermal gas. As an application of the formalism, we consider a general family of exact hairy black hole solutions that, for some particular values of the parameters in the moduli potential, contains solutions of four-dimensional gauged N=8 supergravity and its ω-deformation. Using the AdS/CFT duality dictionary, they correspond to triple trace deformations of the dual field theory.

  8. Path Integrals and Anomalies in Curved Space

    Energy Technology Data Exchange (ETDEWEB)

    Louko, Jorma [University of Nottingham (United Kingdom)

    2007-04-07

    Bastianelli and van Nieuwenhuizen's monograph 'Path Integrals and Anomalies in Curved Space' collects in one volume the results of the authors' 15-year research programme on anomalies that arise in Feynman diagrams of quantum field theories on curved manifolds. The programme was spurred by the path-integral techniques introduced in Alvarez-Gaume and Witten's renowned 1983 paper on gravitational anomalies which, together with the anomaly cancellation paper by Green and Schwarz, led to the string theory explosion of the 1980s. The authors have produced a tour de force, giving a comprehensive and pedagogical exposition of material that is central to current research. The first part of the book develops from scratch a formalism for defining and evaluating quantum mechanical path integrals in nonlinear sigma models, using time slicing regularization, mode regularization and dimensional regularization. The second part applies this formalism to quantum fields of spin 0, 1/2, 1 and 3/2 and to self-dual antisymmetric tensor fields. The book concludes with a discussion of gravitational anomalies in 10-dimensional supergravities, for both classical and exceptional gauge groups. The target audience is researchers and graduate students in curved spacetime quantum field theory and string theory, and the aims, style and pedagogical level have been chosen with this audience in mind. Path integrals are treated as calculational tools, and the notation and terminology are throughout tailored to calculational convenience, rather than to mathematical rigour. The style is closer to that of an exceedingly thorough and self-contained review article than to that of a textbook. As the authors mention, the first part of the book can be used as an introduction to path integrals in quantum mechanics, although in a classroom setting perhaps more likely as supplementary reading than a primary class text. Readers outside the core audience, including this reviewer, will

  9. Lithospheric anisotropy on the Kerguelen hotspot track inferred from Rayleigh wave polarisation anomalies

    Science.gov (United States)

    Pettersen, Øyvind; Maupin, Valérie

    2002-04-01

    Rayleigh waves recorded at the Geoscope station PAF on the Kerguelen Isles in the Indian Ocean, show strong polarisation anomalies in the period range 20-50 s, as demonstrated by dispersion analysis of 3-component recordings. The largest and most consistent anomalies are observed for events located in the southern part of the Java Trench. At 25 s the Rayleigh waves present transverse components with an amplitude of up to 55 per cent of the amplitude of the longitudinal components. The particle motion in the horizontal plane is largely elliptical. By comparison, very few and mostly small polarisation anomalies are detected at the nearby Geoscope stations AIS and CRZF on the Amsterdam and Crozet Isles, respectively. Wave path deviations from the epicentre-receiver great circle, as calculated in tomographic models of the Indian Ocean, cannot explain the polarisation anomalies. Using a multiple-scattering scheme for modelling surface waves in 3-D heterogeneous and anisotropic structures, we show that wavefield distortion due to the geometrical structure of the Kerguelen Plateau in the vicinity of the station cannot explain the anomalies either, but that anisotropy can. We infer the presence of an anisotropic structure in the lithosphere to the north of the Kerguelen Isles, containing 40 per cent oriented pyrolite, with fast axis tilting downwards in a north-north-east direction. The anisotropy may be caused by deformation of the lithosphere related to the Kerguelen hotspot.

  10. Anomaly manifestation of Lieb-Schultz-Mattis theorem and topological phases

    Science.gov (United States)

    Cho, Gil Young; Hsieh, Chang-Tse; Ryu, Shinsei

    2017-11-01

    The Lieb-Schultz-Mattis (LSM) theorem dictates that emergent low-energy states from a lattice model cannot be a trivial symmetric insulator if the filling per unit cell is not integral and if the lattice translation symmetry and particle number conservation are strictly imposed. In this paper, we compare the one-dimensional gapless states enforced by the LSM theorem and the boundaries of one-higher dimensional strong symmetry-protected topological (SPT) phases from the perspective of quantum anomalies. We first note that they can both be described by the same low-energy effective field theory with the same effective symmetry realizations on low-energy modes, wherein non-on-site lattice translation symmetry is encoded as if it were an internal symmetry. In spite of the identical form of the low-energy effective field theories, we show that the quantum anomalies of the theories play different roles in the two systems. In particular, we find that the chiral anomaly is equivalent to the LSM theorem, whereas there is another anomaly that is not related to the LSM theorem but is intrinsic to the SPT states. As an application, we extend the conventional LSM theorem to multiple-charge multiple-species problems and construct several exotic symmetric insulators. We also find that the (3+1)d chiral anomaly provides only the perturbative stability of the gaplessness local in the parameter space.

  11. Relationships between Tropical Rainfall Events and Regional Annual Rainfall Anomalies

    Science.gov (United States)

    Painter, C.; Varble, A.; Zipser, E. J.

    2016-12-01

    Regional annual precipitation anomalies strongly impact the health of regional ecosystems, water resources, agriculture, and the probability of flood and drought conditions. Individual event characteristics, including rain rate, areal coverage, and stratiform fraction are also crucial in considering large-scale impacts on these resources. Therefore, forecasting individual event characteristics is important and could potentially be improved through correlation with longer and better predicted timescale environmental variables such as annual rainfall. This study examines twelve years of retrieved rainfall characteristics from the Tropical Rainfall Measuring Mission (TRMM) satellite at a 5° x 5° resolution between 35°N and 35°S, as a function of annual rainfall anomaly derived from Global Precipitation Climatology Project data. Rainfall event characteristics are derived at a system scale from the University of Utah TRMM Precipitation Features database and at a 5-km pixel scale from TRMM 2A25 products. For each 5° x 5° grid box and year, relationships between these characteristics and annual rainfall anomaly are derived. Additionally, years are separated into wet and dry groups for each grid box and are compared versus one another. Convective and stratiform rain rates, along with system area and volumetric rainfall, generally increase during wetter years, and this increase is most prominent over oceans. This is in agreement with recent studies suggesting that convective systems become larger and rainier when regional annual rainfall increases or when the climate warms. Over some land regions, on the other hand, system rain rate, volumetric rainfall, and area actually decrease as annual rainfall increases. Therefore, land and ocean regions generally exhibit different relationships. In agreement with recent studies of extreme rainfall in a changing climate, the largest and rainiest systems increase in relative size and intensity compared to average systems, and do

  12. [Clinical symptoms and signs in Kimmerle anomaly].

    Science.gov (United States)

    Split, Wojciech; Sawrasewicz-Rybak, Małgorzata

    2002-01-01

    The aim of the study was to consider Kimmerle anomaly (ponticulus posterior of the atlas) as an anatomic variant, which can cause a set of clinical symptoms and signs. A hundred and eight patients, 58 females and 50 males at the age of 18-59 years (M. 36.9 years, SD = 9.6) with radiologically verified Kimmerle anomaly were examined. A control group comprised 40 healthy subjects at the similar age range. The diagnosis of headaches was based on the criteria proposed by the IHS. A character of headaches, their localization, frequency, duration, number of days with headaches per year, circumstances associated with their onset and concomitant symptoms were evaluated. All the patients were subjected to electrophysiological studies (ENG, EEG and VEP). The results were statistically analyzed using a SPSS/PC+ computer system. It was revealed that clinical symptoms and signs in Kimmerle anomaly occurred most frequently in the third and fourth decade of life (65% of cases). These were most often tension-type headaches (50% of cases with headaches), vascular headaches (26% of cases) and neuralgia (24% of cases). Intensity of headaches was high. Headaches were accompanied by other complaints like vertigo (59% of cases) and in one third of cases--nausea. About 10% of patients also suffered from vomiting, paresthesia, dizziness, short periods of loss of consciousness. Sporadically--tinitus, drop attack, and vegetative symptoms. In cases without pain the most frequent signs were short periods of loss of consciousness, dizziness, and also nausea and dizziness. The EEG examination revealed pathology in 40% of patients with Kimmerle anomaly. The ENG examination in more than 33% of anomaly cases showed injury in the central part of vestibular system. Improper answers were reported in about 75% of the patients during the VEP examination.

  13. Prevalence of dental anomalies in a Mexican population

    Directory of Open Access Journals (Sweden)

    Jose Ruben Herrera-Atoche

    2014-12-01

    Full Text Available Background: Data on dental anomaly prevalence is instrumental to diagnosis and treatment in different populations. A retrospective study was done to determine dental anomaly prevalence and associations in a group of orthodontic patients in a Mexican population. Methods: Number, shape, eruption and structural dental anomalies were assessed from the records of 670 subjects. Prevalence, distribution, and associations between the different anomalies were calculated. Chi-squared and Fisher’s exact tests (p<0.05 were used to identify significant differences by sex, and to establish associations among the studied anomalies. Results: Twenty-eight percent of the sample exhibited at least one dental anomaly. Statistical analysis identified no differences by gender. The most common anomaly was impacted teeth (13.58%, followed by microdontic upper lateral incisors (6.26%. These two anomalies also had the highest number of significant associations with other anomalies. Conclusions: The dental anomalies prevalence documented here differ from those reported in the literature for other populations in the world. Dental anomalies are normally associated with each other and occur in groups linked to ethnic origin. The present results indicate the presence of differing suites of anomalies between the studied Mexican population and other populations in the world. This variation highlights the need for further research on dental anomalies in Latin America to aid in their diagnosis and treatment.

  14. Pure duplication of the distal long arm of chromosome 15 with ebstein anomaly and clavicular anomaly.

    Science.gov (United States)

    O'Connor, Rachel; Al-Murrani, Amel; Aftimos, Salim; Asquith, Philip; Mazzaschi, Roberto; Eyrolle-Guignot, Dominique; George, Alice M; Love, Donald R

    2011-01-01

    This report is of a patient with pure trisomy of 15q24-qter who presents with the rare Ebstein anomaly and a previously unreported skeletal anomaly. Chromosome microarray analysis allowed high-resolution identification of the extent of the trisomy and provided a means of achieving higher-resolution breakpoint data. The phenotypic expression of unbalanced chromosomal regions is a complex phenomenon, and fine mapping of the involved region, as described here, is only a first step on the path to its full understanding. Overexpression of the LINGO-1 and CSPG4 genes has been implicated in developmental delay seen in other patients with trisomy of 15q24-qter, but our patient is currently too young to ascertain developmental progress. The genetic underpinning of Ebstein anomaly and the skeletal anomaly reported here is unclear based on our high-resolution dosage mapping.

  15. Pure Duplication of the Distal Long Arm of Chromosome 15 with Ebstein Anomaly and Clavicular Anomaly

    Directory of Open Access Journals (Sweden)

    Rachel O'Connor

    2011-01-01

    Full Text Available This report is of a patient with pure trisomy of 15q24-qter who presents with the rare Ebstein anomaly and a previously unreported skeletal anomaly. Chromosome microarray analysis allowed high-resolution identification of the extent of the trisomy and provided a means of achieving higher-resolution breakpoint data. The phenotypic expression of unbalanced chromosomal regions is a complex phenomenon, and fine mapping of the involved region, as described here, is only a first step on the path to its full understanding. Overexpression of the LINGO-1 and CSPG4 genes has been implicated in developmental delay seen in other patients with trisomy of 15q24-qter, but our patient is currently too young to ascertain developmental progress. The genetic underpinning of Ebstein anomaly and the skeletal anomaly reported here is unclear based on our high-resolution dosage mapping.

  16. Pure Duplication of the Distal Long Arm of Chromosome 15 with Ebstein Anomaly and Clavicular Anomaly

    OpenAIRE

    O'Connor, Rachel; Al-Murrani, Amel; Aftimos, Salim; Asquith, Philip; Mazzaschi, Roberto; Eyrolle-Guignot, Dominique; George, Alice M.; Love, Donald R.

    2011-01-01

    This report is of a patient with pure trisomy of 15q24-qter who presents with the rare Ebstein anomaly and a previously unreported skeletal anomaly. Chromosome microarray analysis allowed high-resolution identification of the extent of the trisomy and provided a means of achieving higher-resolution breakpoint data. The phenotypic expression of unbalanced chromosomal regions is a complex phenomenon, and fine mapping of the involved region, as described here, is only a first step on the path to...

  17. B decay anomalies and dark matter from vectorlike confinement

    Science.gov (United States)

    Cline, James M.

    2018-01-01

    Lepton flavor universality violating B →K ℓℓ and K*ℓℓ decays tentatively observed by LHCb can be explained by leptoquark exchange. We explore a simple model for the B anomalies with a composite leptoquark from new strong dynamics at the TeV scale, a confining SU(NH C) hypercolor interaction. The new matter fields, fundamentals under SU (NH C) , are heavy vectorlike fermions Ψ , S , and an inert scalar doublet ϕ . Ψ is colored under QCD while S is neutral, and the hyperbaryon SN is an asymmetric dark matter candidate. The model is tightly constrained by meson-antimeson oscillations, lepton flavor violation, and LHC searches for resonant production of the exotic bound states. The dark matter may be detectable through its magnetic dipole moment. If mS is sufficiently small, composite leptoquarks and heavy lepton partners can be pair-produced at an observable level at LHC.

  18. Non-perturbative supersymmetry anomaly in supersymmetric QCD

    International Nuclear Information System (INIS)

    Shamir, Y.

    1991-03-01

    The zero modes of the Dirac operator in an instanton and other topologically non-trivial backgrounds are unstable in a large class of massless or partially massless supersymmetric gauge theories. We show that under a generic perturbation of the scalar fields all zero modes become resonances, and discuss the ensuing breakdown of conventional perturbation theory. As a result, despite of the presence of massless fermions, the field theoretic tunneling amplitude is not suppressed. In massless supersymmetric QCD with N c ≤ N f the effective potential is found to be negative and monotonically increasing in the weak coupling regime for scalar VEVs which lie on the perturbatively flat directions. Consequently, massless supersymmetric QCD with N c ≤ N f exhibits a non-perturbative supersymmetry anomaly and exists in a strongly interacting phase which closely resembles ordinary QCD. The same conclusions apply if small masses are added to the lagrangian and the massless limit is smooth. (author). 21 refs, 5 figs

  19. Heat capacity anomalies in Fe8 single crystal

    Science.gov (United States)

    Fominaya, F.; Gandit, P.; Gaudin, G.; Chaussy, J.; Sessoli, R.; Sangregorio, C.

    1999-05-01

    A preliminary heat capacity study of Fe8 molecules as a function of applied magnetic field, temperature and measuring frequency is presented. The heat capacity versus temperature curve shows in zero field several peaks between 2 and 3 K. The anomalies shift to a lower temperature when a magnetic field is applied. With increasing field the peaks are smeared. No frequency dependence could be established in the measured range of ω =217-4440 Hz. We have also performed heat capacity measurements as a function of magnetic field at fixed temperature. Between 2 and 3 K a pattern of well developed peaks at discrete magnetic field values is observed. The pattern strongly changes in the small temperature range between 2.3 and 2.5 K.

  20. Mass hierarchies from anomalies: A peek behind the Planck curtain

    International Nuclear Information System (INIS)

    Ramond, P.

    1996-01-01

    The masses of quarks and leptons suggest a strong hierarchical structure. We argue that their patterns can be reproduced through the introduction of a new Abelian symmetry. The data suggest that this symmetry is anomalous. We suggest that the cancellation of its anomalies occurs through the Green-Schwarz mechanism. An important check of this idea is that it links the Weinberg angle to a mass ration of the elementary fermions. The Green-Schwarz mechanism occurs naturally in many superstring compactifications, and produces a small parameter, which we use to determine the quark mass hierarchy. We show that hierarchy and mixings among the chiral fermions is a consequence of the Green-Schwarz mechanism. We present several models where this idea is realized. 16 refs., 2 tabs

  1. CONGENITAL ANOMALIES OF THE KIDNEYS AND URINARY TRACT IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Matjaž Kopač

    2015-03-01

    Full Text Available Congenital anomalies of the kidney and urinary tract are the commonest congenital anomalies in children, often detected prenatally with ultrasound. This method is useful for assesing the degree of dilatation of the collecting system, structure of the kidney parenchyma, amount of amniotic fluid and urinary bladder. Hydronephrosis is the most common among them. Anomalies can be bilateral or unilateral and different defects may coexist in an individual child. Anomalies of other organs and organ systems are often associated with anomalies of the kidneys and urinary tract, described in numerous syndromes. Congenital anomalies of the kidney and urinary tract can be divided in anomalies of the renal parencyma development, renal embryonic migration and position, cystic kidney diseases and anomalies of the urinary tract (collecting system of the kidneys, ureters, urinary bladder and urethra. They are the commonest cause of end-stage renal disease in children.

  2. Path Integrals and Anomalies in Curved Space

    International Nuclear Information System (INIS)

    Louko, Jorma

    2007-01-01

    Bastianelli and van Nieuwenhuizen's monograph 'Path Integrals and Anomalies in Curved Space' collects in one volume the results of the authors' 15-year research programme on anomalies that arise in Feynman diagrams of quantum field theories on curved manifolds. The programme was spurred by the path-integral techniques introduced in Alvarez-Gaume and Witten's renowned 1983 paper on gravitational anomalies which, together with the anomaly cancellation paper by Green and Schwarz, led to the string theory explosion of the 1980s. The authors have produced a tour de force, giving a comprehensive and pedagogical exposition of material that is central to current research. The first part of the book develops from scratch a formalism for defining and evaluating quantum mechanical path integrals in nonlinear sigma models, using time slicing regularization, mode regularization and dimensional regularization. The second part applies this formalism to quantum fields of spin 0, 1/2, 1 and 3/2 and to self-dual antisymmetric tensor fields. The book concludes with a discussion of gravitational anomalies in 10-dimensional supergravities, for both classical and exceptional gauge groups. The target audience is researchers and graduate students in curved spacetime quantum field theory and string theory, and the aims, style and pedagogical level have been chosen with this audience in mind. Path integrals are treated as calculational tools, and the notation and terminology are throughout tailored to calculational convenience, rather than to mathematical rigour. The style is closer to that of an exceedingly thorough and self-contained review article than to that of a textbook. As the authors mention, the first part of the book can be used as an introduction to path integrals in quantum mechanics, although in a classroom setting perhaps more likely as supplementary reading than a primary class text. Readers outside the core audience, including this reviewer, will gain from the book a

  3. Radiological evaluation congenital gastrointestinal tract anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Hee; Kim, Ock [Hanil Hospital, Seoul (Korea, Republic of); Jang, Jung Wha [Seoul Nationl Hospital, Seoul (Korea, Republic of)

    1983-06-15

    With the improvements, during recent years, in the control of the infections and nutritional diseases the subject of congenital malformation becomes of increasing importance. The radiologic signs are crucial for prompt diagnosis of anomalies of alimentary tract and with early identification of resulting complication, surgical therapy is usually life-saving. 30 cases of congenital anomalies of alimentary tract in infants were reviewed in respect of age, sex, incidence and radiological findings. The results are summarized as follows; 1, The most common lesion was hypertrophic pyloric stenosis, followed by congenital megacolon and anorectal anomaly, tracheoesophageal fistula, intestinal atresia. 2. Male outnumbered female in most congenital anomalies of alimentary tract. 25 cases were under the age of 1 month. 3. Common symptoms of upper gastrointestinal tract obstruction are vomiting and abdominal distension. In the obstruction of lower gastrointestinal tract, abdominal distension and failure of meconium passage were noted. 4. Roentgenologic findings were as follows, a. Chest A-P and lateral view: In tracheoesophageal fistula, saccular dilatation of upper esophagus and displacement of trachea anterolaterally were the most common finding. b. Simple abdomen: Obstructive pattern of proximal portion of duodenum shows in 11 cases, of distal bowel shows in 16 cases. Duodenal atresia showed 'double bubble' sign, hypertrophic pyloric stenosis showed marked gastric distension, paucity of air in small bowel and increases gastric peristalsis were the most common findings. Hirschsprung's disease showed absenced of rectal gas almostly. The variable length between blind hindgut to anus was seen in anorectal anomalies. c. Esophagogram: Blind sac of upper esophagus was seen at the 4th thoracic spinal level and displacement of trachea anterolaterally. 1 case of tracheoesophageal fistula had an intact esophageal lumen. d. Upper G-I series: In hypertrophic pyloric

  4. Radiological evaluation congenital gastrointestinal tract anomalies

    International Nuclear Information System (INIS)

    Cho, Young Hee; Kim, Ock; Jang, Jung Wha

    1983-01-01

    With the improvements, during recent years, in the control of the infections and nutritional diseases the subject of congenital malformation becomes of increasing importance. The radiologic signs are crucial for prompt diagnosis of anomalies of alimentary tract and with early identification of resulting complication, surgical therapy is usually life-saving. 30 cases of congenital anomalies of alimentary tract in infants were reviewed in respect of age, sex, incidence and radiological findings. The results are summarized as follows; 1, The most common lesion was hypertrophic pyloric stenosis, followed by congenital megacolon and anorectal anomaly, tracheoesophageal fistula, intestinal atresia. 2. Male outnumbered female in most congenital anomalies of alimentary tract. 25 cases were under the age of 1 month. 3. Common symptoms of upper gastrointestinal tract obstruction are vomiting and abdominal distension. In the obstruction of lower gastrointestinal tract, abdominal distension and failure of meconium passage were noted. 4. Roentgenologic findings were as follows, a. Chest A-P and lateral view: In tracheoesophageal fistula, saccular dilatation of upper esophagus and displacement of trachea anterolaterally were the most common finding. b. Simple abdomen: Obstructive pattern of proximal portion of duodenum shows in 11 cases, of distal bowel shows in 16 cases. Duodenal atresia showed 'double bubble' sign, hypertrophic pyloric stenosis showed marked gastric distension, paucity of air in small bowel and increases gastric peristalsis were the most common findings. Hirschsprung's disease showed absenced of rectal gas almostly. The variable length between blind hindgut to anus was seen in anorectal anomalies. c. Esophagogram: Blind sac of upper esophagus was seen at the 4th thoracic spinal level and displacement of trachea anterolaterally. 1 case of tracheoesophageal fistula had an intact esophageal lumen. d. Upper G-I series: In hypertrophic pyloric stenosis, delayed

  5. Electric propulsion reliability: Statistical analysis of on-orbit anomalies and comparative analysis of electric versus chemical propulsion failure rates

    Science.gov (United States)

    Saleh, Joseph Homer; Geng, Fan; Ku, Michelle; Walker, Mitchell L. R.

    2017-10-01

    With a few hundred spacecraft launched to date with electric propulsion (EP), it is possible to conduct an epidemiological study of EP's on orbit reliability. The first objective of the present work was to undertake such a study and analyze EP's track record of on orbit anomalies and failures by different covariates. The second objective was to provide a comparative analysis of EP's failure rates with those of chemical propulsion. Satellite operators, manufacturers, and insurers will make reliability- and risk-informed decisions regarding the adoption and promotion of EP on board spacecraft. This work provides evidence-based support for such decisions. After a thorough data collection, 162 EP-equipped satellites launched between January 1997 and December 2015 were included in our dataset for analysis. Several statistical analyses were conducted, at the aggregate level and then with the data stratified by severity of the anomaly, by orbit type, and by EP technology. Mean Time To Anomaly (MTTA) and the distribution of the time to (minor/major) anomaly were investigated, as well as anomaly rates. The important findings in this work include the following: (1) Post-2005, EP's reliability has outperformed that of chemical propulsion; (2) Hall thrusters have robustly outperformed chemical propulsion, and they maintain a small but shrinking reliability advantage over gridded ion engines. Other results were also provided, for example the differentials in MTTA of minor and major anomalies for gridded ion engines and Hall thrusters. It was shown that: (3) Hall thrusters exhibit minor anomalies very early on orbit, which might be indicative of infant anomalies, and thus would benefit from better ground testing and acceptance procedures; (4) Strong evidence exists that EP anomalies (onset and likelihood) and orbit type are dependent, a dependence likely mediated by either the space environment or differences in thrusters duty cycles; (5) Gridded ion thrusters exhibit both

  6. Convection anomalies associated with warm eddy at the coastal area

    Science.gov (United States)

    Shi, R.; Wang, D.

    2017-12-01

    A possible correlation between a warm eddy and thunderstorms and convective precipitations are investigated at the coastal area in the northwestern South China Sea. Compared to the climatological mean in August from 2006 to 2013, an extreme enhancement of thunderstorm activities and precipitation rate are identified at the southern offshore area of Hainan island in August 2010 when a strong and long-live warm eddy was observed near the coastline at the same time. The 3 hourly satellite data (TRMM) indicate that the nocturnal convections is strong offshore and that could be responsible for the extreme positive anomalies of thunderstorms and rainfall in August 2010. The TRMM data also show a small reduction of thunderstorm activities and rainfall on the island in the afternoon. Meanwhile, the Weather Research and Forecasting (WRF) model was applied to simulate the change of rainfall in August 2010. The WRF simulation of rainfall rate is comparable with the observation results while there is some difference in the spatial distribution. The WRF simulation successfully captured the strong offshore rainfall and the diurnal variation of rainfall in August 2010. The WRF simulation indicated that the different convergence induced by sea/land breeze could be one essential reason for the adjustment of thunderstorms and rainfall in 2010. The substantial connection between sea/land breeze and upper layer heat content modified by the warm eddy is still on ongoing and will be reported in the future work.

  7. Minor Physical Anomalies, Footprints, and Behavior: Was the Buddha Right?

    Science.gov (United States)

    Draper, Thomas W.; Munoz, Milagros M.

    1982-01-01

    A relationship between an anomaly of the footprint suggested by ancient Abhidhamma meditations and Minor Physical Anomalies Scale was observed in children. The footprint anomalies correlated with the activity levels of children in the same way as the scores on the scale and consistently with prior research using the scale. (Author/RD)

  8. Spectrum of congenital anomalies in pregnancies with pregestational diabetes

    NARCIS (Netherlands)

    Garne, Ester; Loane, Maria; Dolk, Helen; Barisic, Ingeborg; Addor, Marie-Claude; Arriola, Larraitz; Bakker, Marian; Calzolari, Elisa; Dias, Carlos Matias; Doray, Berenice; Gatt, Miriam; Melve, Kari Klyungsoyr; Nelen, Vera; O'Mahony, Mary; Pierini, Anna; Randrianaivo-Ranjatoelina, Hanitra; Rankin, Judith; Rissmann, Anke; Tucker, David; Verellun-Dumoulin, Christine; Wiesel, Awi

    BACKGROUND Maternal pregestational diabetes is a well-known risk factor for congenital anomalies. This study analyses the spectrum of congenital anomalies associated with maternal diabetes using data from a large European database for the population-based surveillance of congenital anomalies.

  9. Prediction of gravity anomalies for geophysical exploration | Idowu ...

    African Journals Online (AJOL)

    Where the density of the available gravity anomalies is not enough, for a particular purpose of geophysical exploration, more gravity stations can be established within the surveyed area and the gravity anomalies observed for these stations. In some cases, where observations of gravity anomalies are not possible due, ...

  10. High Type Imperforate Anus Without Associated Anomalies in a ...

    African Journals Online (AJOL)

    Background: The High type imperforate anus is usually associated with congenital anomaly in the other systems or organs. It is rare to have the above type without accompanying anomalies. Aim: To report a case of high imperforate anus without associated anomalies of the other systems or organs in a Nigerian child who ...

  11. Lithologic boundaries from gravity and magnetic anomalies over ...

    Indian Academy of Sciences (India)

    67

    shows the same trend as that of Bouguer gravity anomaly and total magnetic intensity anomaly map indicating towards a shallow sources. The magnetic map in general ..... keeping the ERT results in consideration we have chosen the upward continuation at 150 m as regional anomaly both for gravity and magnetic studies.

  12. Spectrum of congenital anomalies in pregnancies with pregestational diabetes

    DEFF Research Database (Denmark)

    Garne, Ester; Loane, Maria; Dolk, Helen

    2012-01-01

    Maternal pregestational diabetes is a well-known risk factor for congenital anomalies. This study analyses the spectrum of congenital anomalies associated with maternal diabetes using data from a large European database for the population-based surveillance of congenital anomalies....

  13. Calendar anomalies in the Russian stock market

    Directory of Open Access Journals (Sweden)

    Guglielmo Maria Caporale

    2017-03-01

    Full Text Available This research note investigates whether or not calendar anomalies (such as the January, day-of-the-week and turn-of-the-month effects characterize the Russian stock market, which could be interpreted as evidence against market efficiency. Specifically, OLS, GARCH, EGARCH and TGARCH models are estimated using daily data for the MICEX market index over the period Sept. 1997–Apr. 2016. The empirical results show the importance of taking into account transactions costs (proxied by the bid-ask spreads: once these are incorporated into the analysis, calendar anomalies disappear, and therefore, there is no evidence of exploitable profit opportunities based on them that would be inconsistent with market efficiency.

  14. International Space Station (ISS) Anomalies Trending Study

    Science.gov (United States)

    Beil, Robert J.; Brady, Timothy K.; Foster, Delmar C.; Graber, Robert R.; Malin, Jane T.; Thornesbery, Carroll G.; Throop, David R.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) set out to utilize data mining and trending techniques to review the anomaly history of the International Space Station (ISS) and provide tools for discipline experts not involved with the ISS Program to search anomaly data to aid in identification of areas that may warrant further investigation. Additionally, the assessment team aimed to develop an approach and skillset for integrating data sets, with the intent of providing an enriched data set for discipline experts to investigate that is easier to navigate, particularly in light of ISS aging and the plan to extend its life into the late 2020s. This report contains the outcome of the NESC Assessment.

  15. Helical CT of congenital ossicular anomalies

    International Nuclear Information System (INIS)

    Osada, Hisato; Machida, Kikuo; Honda, Norinari

    2001-01-01

    Since January 1996 to December 2000, 26 cases of congenital ossicular anomaly could be diagnosed with helical CT. All cases were unilateral. In 8 patients with malformation of the external ear, CT showed malleoincudal fixation (n=5), malleoincudal fixation and deformed incuts long process (n=1), deformed incus long process (n=1), and partial fusion of malleus neck and incus long process (n=1). In 18 patients with normal external ear, CT showed defect of the incus long process (n=5), defect of both the incus long process and stapes superstructure (n=8, 2 patients with congenital cholesteatoma, 1 with hypoplastic oval window), defect of the stapes superstructure (n=2, 1 patient with oval window absence), defect of the malleus manubrium (n=1), ossification of the stampede's tendon (n=1), and monopod stapes (n=1). Helical CT can evaluate the auditory ossicular chain in detail and is useful for diagnosing congenital ossicular anomaly. (author)

  16. MR imaging evaluation of congenital spine anomalies

    International Nuclear Information System (INIS)

    Bury, E.A.; Zimmerman, R.A.; Grossman, R.I.; Goldberg, H.I.; Bilaniuk, L.T.; Hackney, D.B.

    1987-01-01

    Over a 2-year period, 135 patients between the ages of 1 week and 18 years were examined with MR imaging for possible congenital anomalies of the spine and spinal cord. Tethered cords with various other associated pathologies such as lipomas and myelomeningoceles were found in 36 patients. The remaining abnormal examinations consisted of syrinxes, Chiari malformations, diastematomyelia, and conus masses. In 55 patients the studies were interpreted as normal. Of these, three were subsequently shown by surgery of myelography to be abnormal. The first had a thickened filum with a small epidermoid, the second a thickened filum, and the third, with only sagittal images, a diastematomyelia. Children presenting with symptoms highly suspicious for congenital abnormalities but with a normal MR study in multiple planes may still require further evaluation with myelography. Multiplanar MR examination in most instances will be a sufficient evaluation for congenital anomalies

  17. Congenital anomalies after assisted reproductive technology

    DEFF Research Database (Denmark)

    Pinborg, Anja; Henningsen, Anna-Karina Aaris; Malchau, Sara Sofie

    2013-01-01

    Worldwide, more than 5 million children have been born after assisted reproductive technology (ART), and in many developed countries ART infants represent more than 1% of the birth cohorts. It is well known that ART children are at increased risk of congenital malformations even after adjustment...... for known confounders such as maternal age. The proportion of ART children is not negligible, and knowledge about the causes of the higher risk of congenital malformations is crucial to develop prevention strategies to reduce the future risk in ART children. The aim of this review is to summarize...... the literature on the association between ART and congenital anomalies with respect to subfertility, fertility treatment other than ART, and different ART methods including intracytoplasmic sperm injection, blastocyst culture, and cryotechniques. Trends over time in ART and congenital anomalies will also...

  18. Network Anomaly Detection Based on Wavelet Analysis

    Directory of Open Access Journals (Sweden)

    Ali A. Ghorbani

    2008-11-01

    Full Text Available Signal processing techniques have been applied recently for analyzing and detecting network anomalies due to their potential to find novel or unknown intrusions. In this paper, we propose a new network signal modelling technique for detecting network anomalies, combining the wavelet approximation and system identification theory. In order to characterize network traffic behaviors, we present fifteen features and use them as the input signals in our system. We then evaluate our approach with the 1999 DARPA intrusion detection dataset and conduct a comprehensive analysis of the intrusions in the dataset. Evaluation results show that the approach achieves high-detection rates in terms of both attack instances and attack types. Furthermore, we conduct a full day's evaluation in a real large-scale WiFi ISP network where five attack types are successfully detected from over 30 millions flows.

  19. Focal pachygyria with unusual vascular anomaly.

    Science.gov (United States)

    Watanabe, M; Tanaka, R; Takeda, N; Ikuta, F; Oyanagi, K

    1990-01-01

    A case of focal pachygyria with an unusual vascular anomaly is reported. Preoperative magnetic resonance imaging demonstrated few and broad gyri, and an abnormally thickened cortex of the right frontal lobe. In addition, T2-weighted imaging showed a high intensity lesion beneath the thickened cortex. In the pachygyric cortex, the peripheral portions of the arteries were tortuous and irregularly dilated, and prominent deep medullary veins were found draining into the subependymal veins. Histological examination revealed a decreased number of neurons with no tendency towards lamination, and degenerative changes with gliosis in the white matter. These findings suggest that the etiology of this anomaly may be gradual perfusion failure restricted to the territory of the anomalous vessels through the period of neuronal migration to the post-migratory, perinatal stage.

  20. [Ebstein's anomaly associated with interventricular communication].

    Science.gov (United States)

    da Silveira, W L; Leite, A F; Fernandes, R L; de Oliveira, V G; de Mesquita, A O; Melo, J C; Machado, W A; da Silva, M A

    1993-06-01

    Twelve-year-old patient, with congestive heart failure and mild, caused by Ebstein's anomaly with interventricular septal defect, was studied and submitted to surgical correction which consisted in covering the interventricular defect with a path of bovine pericardium and substituting for the tricuspid valve with a biological prosthesis (porcine). After surgical correction, the patient was submitted to strict clinical and laboratorial (echocardiogram and cardiac catheterization) evaluation which presented excellent adjustment of the cardiac antriums, with improvement of myocardial function index. The problems related to the diagnosis of the association of the Ebstein's anomaly with interventricular septal defect can be solved with a well done semiology, helped by accurate laboratorial procedures like echodopplercardiogram and cardiac catheterization. The total surgical correction can be achieved with results and, with this fact, change the natural development of the disease.

  1. Dental anomaly patterns associated with tooth agenesis.

    Science.gov (United States)

    Choi, Su Ji; Lee, Je Woo; Song, Ji Hyun

    2017-04-01

    The objective of this study is to evaluate the relationship between tooth agenesis and the occurrence of other dental anomalies in children and adolescents. Panoramic radiographs of 195 subjects with tooth agenesis, except for the third molar, were retrospectively examined and compared with a non-agenesis control group of 600 subjects. Their ages ranged from 7 to 15 years. Panoramic and periapical radiographs were used to analyze the presence of other associated dental anomalies. The occurrences of these anomalies were compared with those in the non-agenesis group. Subjects with tooth agenesis showed a significantly higher prevalence of a small maxillary lateral incisor (17.7%), distoangulation of the mandibular second premolar (6.5%), delayed development of a permanent tooth (10.8%), and hypo-occlusion of a primary molar (11.8%). In contrast, the prevalence of a supernumerary tooth was higher in the control group, and no difference was observed in the prevalence of ectopic eruption of a first molar. According to the agenesis area, microdontia of the maxillary lateral incisors occurred more often in patients with anterior or premolar agenesis than in the molar agenesis groups. Distoangulation of the mandibular second premolars, delayed tooth development, and hypo-occlusion of the primary molars were associated with premolar tooth agenesis. A small maxillary lateral incisor, distoangulation of the mandibular second premolar, delayed development of a permanent tooth, and hypo-occlusion of a primary molar were frequently associated with tooth agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies.

  2. Adaptive Anomaly Detection using Isolation Forest

    Science.gov (United States)

    2009-12-20

    5) Personnel Supported The grant is used to support a research assistant James Tan Swee Chuan, part-time for a period of 10 months. (6...Information Technology Faculty: Information Technology 1 Mass: A New Ranking Measure for Anomaly Detection Kai Ming Ting, James Tan Swee Chuan...processing and computer vision, Whistler (2002). [6] P. Domingos and G. Hulten, Mining high-speed data streams, Proceedings of the Sixth ACM SIGKDD

  3. Tree-ring anomalies in Toona ciliata

    OpenAIRE

    Heinrich, Ingo; Banks, John Charles Gripper

    2006-01-01

    New increment core samples of Toona ciliata collected in the Australian tropics and subtropics compared to already existing material from the Upper Kangaroo Valley, near Sydney exhibit distinct differences in tree-ring structures. This necessitated a closer examination of the wood anatomy, possible false rings and the species’ crossdating capacity in northeast Australia. During tree-ring analysis two growth anomalies (extensive zones of narrow and indistinct rings) and three types of false ri...

  4. Fusion and normalization to enhance anomaly detection

    Science.gov (United States)

    Mayer, R.; Atkinson, G.; Antoniades, J.; Baumback, M.; Chester, D.; Edwards, J.; Goldstein, A.; Haas, D.; Henderson, S.; Liu, L.

    2009-05-01

    This study examines normalizing the imagery and the optimization metrics to enhance anomaly and change detection, respectively. The RX algorithm, the standard anomaly detector for hyperspectral imagery, more successfully extracts bright rather than dark man-made objects when applied to visible hyperspectral imagery. However, normalizing the imagery prior to applying the anomaly detector can help detect some of the problematic dark objects, but can also miss some bright objects. This study jointly fuses images of RX applied to normalized and unnormalized imagery and has a single decision surface. The technique was tested using imagery of commercial vehicles in urban environment gathered by a hyperspectral visible/near IR sensor mounted in an airborne platform. Combining detections first requires converting the detector output to a target probability. The observed anomaly detections were fitted with a linear combination of chi square distributions and these weights were used to help compute the target probability. Receiver Operator Characteristic (ROC) quantitatively assessed the target detection performance. The target detection performance is highly variable depending on the relative number of candidate bright and dark targets and false alarms and controlled in this study by using vegetation and street line masks. The joint Boolean OR and AND operations also generate variable performance depending on the scene. The joint SUM operation provides a reasonable compromise between OR and AND operations and has good target detection performance. In addition, new transforms based on normalizing correlation coefficient and least squares generate new transforms related to canonical correlation analysis (CCA) and a normalized image regression (NIR). Transforms based on CCA and NIR performed better than the standard approaches. Only RX detection of the unnormalized of the difference imagery in change detection provides adequate change detection performance.

  5. Anomaly extraction from the path integral

    International Nuclear Information System (INIS)

    Christos, G.A.

    1983-01-01

    Fujikawa's recently proposed derivation of the anomaly from the path integral is examined. It is attempted to give a better understanding of his work. In particular, evasions of his result are discussed; for example it is shown how chiral U(1) axial invariance can be maintained by employing a gauge variant regularization prescription. A brief connection with the point-splitting method is also made. (orig.)

  6. Walls, anomalies, and deconfinement in quantum antiferromagnets

    Science.gov (United States)

    Komargodski, Zohar; Sulejmanpasic, Tin; Ünsal, Mithat

    2018-02-01

    We consider the Abelian-Higgs model in 2 +1 dimensions with instanton-monopole defects. This model is closely related to the phases of quantum antiferromagnets. In the presence of Z2 preserving monopole operators, there are two confining ground states in the monopole phase, corresponding to the valence bond solid (VBS) phase of quantum magnets. We show that the domain wall carries a 't Hooft anomaly in this case. The anomaly can be saturated by, e.g., charge-conjugation breaking on the wall or by the domain wall theory becoming gapless (a gapless model that saturates the anomaly is S U (2) 1 WZW). Either way the fundamental scalar particles (i.e., spinons) which are confined in the bulk are deconfined on the domain wall. This Z2 phase can be realized either with spin-1/2 on a rectangular lattice or spin-1 on a square lattice. In both cases the domain wall contains spin-1/2 particles (which are absent in the bulk). We discuss the possible relation to recent lattice simulations of domain walls in VBS. We further generalize the discussion to Abrikosov-Nielsen-Olsen (ANO) vortices in a dual superconductor of the Abelian-Higgs model in 3 +1 dimensions and to the easy-plane limit of antiferromagnets. In the latter case the wall can undergo a variant of the BKT transition (consistent with the anomalies) while the bulk is still gapped. The same is true for the easy-axis limit of antiferromagnets. We also touch upon some analogies to Yang-Mills theory.

  7. Coronary Anomalies: Left Main Coronary Artery Aneurysm

    OpenAIRE

    Varda, Rajsekhar; Chitimilla, Santosh Kumar; Lalani, Aslam

    2012-01-01

    Coronary artery aneurysm is one of the rarest anomalies that we see in our medical practice and they are mostly associated with obstructive lesions due to atherosclerotic changes. Management of these aneurysm patients (conservative or surgical repair) usually depends on obstructive lesions and associated symptoms. We are presenting a case of left main aneurysm measuring around 1 4 × 2 8  mm with other obstructive leisons. It was treated with surgical repair in view of obstructive lesions and ...

  8. Coronary Anomalies: Left Main Coronary Artery Aneurysm

    Directory of Open Access Journals (Sweden)

    Rajsekhar Varda

    2012-01-01

    Full Text Available Coronary artery aneurysm is one of the rarest anomalies that we see in our medical practice and they are mostly associated with obstructive lesions due to atherosclerotic changes. Management of these aneurysm patients (conservative or surgical repair usually depends on obstructive lesions and associated symptoms. We are presenting a case of left main aneurysm measuring around 14×28 mm with other obstructive leisons. It was treated with surgical repair in view of obstructive lesions and symptoms.

  9. Standard Model Effective Potential from Trace Anomalies

    Directory of Open Access Journals (Sweden)

    Renata Jora

    2018-01-01

    Full Text Available By analogy with the low energy QCD effective linear sigma model, we construct a standard model effective potential based entirely on the requirement that the tree level and quantum level trace anomalies must be satisfied. We discuss a particular realization of this potential in connection with the Higgs boson mass and Higgs boson effective couplings to two photons and two gluons. We find that this kind of potential may describe well the known phenomenology of the Higgs boson.

  10. Unsuspected urological anomalies in asymptomatic cryptorchid boys

    Energy Technology Data Exchange (ETDEWEB)

    Pappis, C.H.; Argianas, S.A.; Bousgas, D.; Athanasiades, E.

    1988-01-01

    In a period of 6 years 144 asymptomatic boys with cryptorchidism, of mean age 7 +- SD 3.5 years, underwent orchiopexy. None of these boys referred to a history of a known urological anomaly, urinary tract infection haematuria, palpable mass in the renal region, bladder extrophy, epispadias, hypospadias or anorectal malformation. On the third day after orchiopexy an intravenous pyelography was done in every boy following testicular protection against irradiation. Ultrasonic investigation was not available at that time. There were minor urological abnormalities in 36 (25%) boys and major ones in 8 (5.5%) boys. A major anomaly is defined as one resulting in significant loss of renal substance (one case of single kidney and three cases of unilateral renal hypoplasia), or requiring surgical correction for conservation of the renal substance (one case of ureterocele, two cases of pelviureteric stenosis and one case of vesicoureteric stenosis with ipsilateral hydronephrosis). The unsuspected major urological abnormalities are usually ipsilateral to the more undescended testis. They may be associated with a hernia and are more frequent in bilateral cryptorchidism. In conclusion we encourage the routine use of IVP, or ultrasonic investigation or dynamic renal scanning (99/sup mTc/-DTPA), if it is possible, in all patients undergoing orchiopexy for the detection of an unsuspected major renal anomaly.

  11. Venous Thromboembolism in Pediatric Vascular Anomalies

    Directory of Open Access Journals (Sweden)

    Taizo A. Nakano

    2017-07-01

    Full Text Available The presence of a vascular anomaly suggests that capillaries, veins, arteries, and/or lymphatic vessels have demonstrated abnormal development and growth. Often dilated and misshaped, these vessels augment normal flow of blood and lymphatic fluids that increases the overall risk to develop intralesional thrombosis. Abnormal endothelial and lymphoendothelial cells activate hemostasis and hyperfibrinolytic pathways through poorly understood mechanisms, which contribute to the development of localized intravascular coagulopathy. Vascular malformations, tumors, and complex combined syndromes demonstrate varying degrees of prothrombotic activity and consumptive coagulopathy depending on the vessels involved and the pattern and extent of abnormal growth. The clinical impact of venous thromboembolism in pediatric vascular anomalies varies from painful syndromes that disrupt quality of life to life-threatening embolic disease. There remains little literature on the study, evaluation, and treatment of thrombosis in pediatric vascular anomalies. However, there have been great advances in our ability to image complex lesions, to surgically and interventionally augment disease, and to provide enhanced supportive care including patient education, compression therapy, and strategic use of anticoagulation.

  12. Uranium Groundwater Anomalies and Active Normal Faulting

    International Nuclear Information System (INIS)

    Plastino, Wolfango; Panza, Giuliano Francesco; Doglioni, Carlo

    2010-08-01

    The ability to predict earthquakes is one of the greatest challenges for Earth Sciences. Radon has been suggested as one possible precursor, and its groundwater anomalies associated with earthquakes and water-rock interactions were proposed in several seismogenic areas worldwide as due to possible transport of radon through microfractures, or due to crustal gas fluxes along active faults. However, the use of radon as a possible earthquake's precursor is not clearly linked to crustal deformation. Here we show that uranium groundwater anomalies, which were observed in cataclastic rocks crossing the underground Gran Sasso National Laboratory, can be used as a possible precursor of earthquakes in domains where continental lithosphere is subducted. Measurements evidence clear, sharp anomalies from July, 2008 to the end of March, 2009, related to a preparation phase of the seismic swarm, which occurred near L'Aquila, Italy, from October, 2008 to April, 2009. On April 6th, 2009 an earthquake (M w =6.3) occurred at 01:33 UT in the same area, with normal faulting on a NW-SE oriented structure about 15 km long, dipping toward SW. In the framework of the geophysical and geochemical models of the area, these measurements indicate that uranium may be used as a possible strain meter in extensional tectonic settings similar to those where the L'Aquila earthquake occurred. (author)

  13. Congenital anomalies and proximity to landfill sites.

    LENUS (Irish Health Repository)

    Boyle, E

    2004-01-01

    The occurrence of congenital anomalies in proximity to municipal landfill sites in the Eastern Region (counties Dublin, Kildare, Wicklow) was examined by small area (district electoral division), distance and clustering tendancies in relation to 83 landfills, five of which were major sites. The study included 2136 cases of congenital anomaly, 37,487 births and 1423 controls between 1986 and 1990. For the more populous areas of the region 50% of the population lived within 2-3 km of a landfill and within 4-5 km for more rural areas. In the area-level analysis, the standardised prevalence ratios, empirical and full Bayesian modelling, and Kulldorff\\'s spatial scan statistic found no association between the residential area of cases and location of landfills. In the case control analysis, the mean distance of cases and controls from the nearest landfill was similar. The odds ratios of cases compared to controls for increasing distances from all landfills and major landfills showed no significant difference from the baseline value of 1. The kernel and K methods showed no tendency of cases to cluster in relationship to landfills. In conclusion, congenital anomalies were not found to occur more commonly in proximity to municipal landfills.

  14. Power coefficient anomaly in Joyo, (2)

    International Nuclear Information System (INIS)

    Ishikawa, Makoto; Yamashita, Yoshioki; Sasaki, Makoto; Nara, Yoshihiko.

    1981-12-01

    In this report, the presumption about the mechanism having caused the power coefficient anomaly in Joyo during the 75 MW power-raising test in 1979 is described. After the previous report, the new information about the results of the post-irradiation examination and the analysis of the power coefficient of Joyo were able to be obtained. From these information, the mechanism of causing the anomaly was presumed as follows. In 50 MW operation, the fuel burnup reached about 10,000 MWD/ton at the end of second cycle, and produced fission gas was almost retained in fuel pellets. When the power was raised from 50 MW to 75 MW for the first time, the fission gas began to be released when 50 MW was somewhat exceeded. The fission gas release caused the temperature rise and cracking of fuel pellets, and elongated fuel stack length abruptly. These phenomena induced to enlarge the fuel expansion reactivity effect and Doppler reactivity effect, and caused the anomalous behavior of power coefficient. After reaching 75 MW, the fuel stack length did not respond normally to reactor power change, and the magnitude of power coefficient became smaller. The reactivity was lost considerably from the core after the anomaly. (Kako, I.)

  15. Flavorful hybrid anomaly-gravity mediation

    International Nuclear Information System (INIS)

    Gross, Christian; Hiller, Gudrun

    2011-01-01

    We consider supersymmetric models where anomaly and gravity mediation give comparable contributions to the soft terms and discuss how this can be realized in a five-dimensional brane world. The gaugino mass pattern of anomaly mediation is preserved in such a hybrid setup. The flavorful gravity-mediated contribution cures the tachyonic slepton problem of anomaly mediation. The supersymmetric flavor puzzle is solved by alignment. We explicitly show how a working flavor-tachyon link can be realized with Abelian flavor symmetries and give the characteristic signatures of the framework, including O(1) slepton mass splittings between different generations and between doublets and singlets. This provides opportunities for same flavor dilepton edge measurements with missing energy at the Large Hadron Collider (LHC). Rare lepton decay rates could be close to their current experimental limit. Compared to pure gravity mediation, the hybrid model is advantageous because it features a heavy gravitino which can avoid the cosmological gravitino problem of gravity-mediated models combined with leptogenesis.

  16. Thermal Expansion Anomaly Regulated by Entropy

    Science.gov (United States)

    Liu, Zi-Kui; Wang, Yi; Shang, Shunli

    2014-11-01

    Thermal expansion, defined as the temperature dependence of volume under constant pressure, is a common phenomenon in nature and originates from anharmonic lattice dynamics. However, it has been poorly understood how thermal expansion can show anomalies such as colossal positive, zero, or negative thermal expansion (CPTE, ZTE, or NTE), especially in quantitative terms. Here we show that changes in configurational entropy due to metastable micro(scopic)states can lead to quantitative prediction of these anomalies. We integrate the Maxwell relation, statistic mechanics, and first-principles calculations to demonstrate that when the entropy is increased by pressure, NTE occurs such as in Invar alloy (Fe3Pt, for example), silicon, ice, and water, and when the entropy is decreased dramatically by pressure, CPTE is expected such as in anti-Invar cerium, ice and water. Our findings provide a theoretic framework to understand and predict a broad range of anomalies in nature in addition to thermal expansion, which may include gigantic electrocaloric and electromechanical responses, anomalously reduced thermal conductivity, and spin distributions.

  17. The relationship between precipitation anomalies and satellite-derived vegetation activity in Central Asia

    Science.gov (United States)

    Gessner, Ursula; Naeimi, Vahid; Klein, Igor; Kuenzer, Claudia; Klein, Doris; Dech, Stefan

    2013-11-01

    In Central Asia, water is a particularly scarce and valuable good. In many ecosystems of this region, the vegetation development during the growing season is dependent on water provided by rainfall. With climate change, alterations of the seasonal distribution of precipitation patterns and a higher frequency of extreme events are expected. Vegetation dynamics are likely to respond to these changes and thus ecosystem services will be affected. However, there is still a lack in understanding the response of vegetation to precipitation anomalies, especially for dryland regions such as Central Asia. This study aims to contribute to an improved understanding of vegetation sensitivity to precipitation anomalies and corresponding temporal reaction patterns at regional scale. The presented analyses are based on time-series of Normalized Difference Vegetation Index (NDVI) and gridded precipitation datasets (GPCC Full Data Reanalysis) for the years 1982-2006. Time-series correlation analyses show that vegetation development is sensitive to precipitation anomalies for nearly 80% of the Central Asian land surface. Results indicate a particularly strong sensitivity of vegetation in areas with 100-400 mm of annual rainfall. Temporal rainfall-NDVI response patterns show a temporal lag between precipitation anomalies and vegetation activity of 1-3 months. The reaction of vegetation was found to be strongest for precipitation anomalies integrated over periods of 2-4 months. The observed delayed response of vegetation to precipitation anomalies reveals potential for drought prediction in Central Asia. The spatial patterns of vegetation reactions are discussed with focus on the role of precipitation amount and seasonality, land use and land cover.

  18. CT diagnosis of congenital anomalies of the central nervous system

    International Nuclear Information System (INIS)

    Mori, Koreaki

    1980-01-01

    In the diagnosis of central nervous system congenital anomalies, understanding of embryology of the central nervous system and pathophysiology of each anomaly are essential. It is important for clinical approach to central nervous system congenital anomalies to evaluate the size of the head and tention of the anterior fontanelle. Accurate diagnosis of congenital anomalies depends on a correlation of CT findings to clinical pictures. Clinical diagnosis of congenital anomalies should include prediction of treatability and prognosis, in addition to recognition of a disease. (author)

  19. Bias dependent subband edges and the 0.7 conductance anomaly

    DEFF Research Database (Denmark)

    Kristensen, Anders; Bruus, Henrik

    2002-01-01

    The 0.7 (2e(2)/h) conductance anomaly is studied in strongly confined, etched GaAs/GaAlAs quantum point contacts by measuring the differential conductance G as a function of source-drain bias V-sd and gate-source bias V-gs as well as a function of temperature. In the V-gs - V-sd plane we use...

  20. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  1. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  2. Impending ionospheric anomaly preceding the Iquique Mw8.2 earthquake in Chile on 2014 April 1

    Science.gov (United States)

    Guo, Jinyun; Li, Wang; Yu, Hongjuan; Liu, Zhimin; Zhao, Chunmei; Kong, Qiaoli

    2015-12-01

    To investigate the coupling relationship between great earthquake and ionosphere, the GPS-derived total electron contents (TECs) by the Center for Orbit Determination in Europe and the foF2 data from the Space Weather Prediction Center were used to analyse the impending ionospheric anomalies before the Iquique Mw8.2 earthquake in Chile on 2014 April 1. Eliminating effects of the solar and geomagnetic activities on ionosphere by the sliding interquartile range with the 27-day window, the TEC analysis results represent that there were negative anomalies occurred on 15th day prior to the earthquake, and positive anomalies appeared in 5th day before the earthquake. The foF2 analysis results of ionosonde stations Jicamarca, Concepcion and Ramey show that the foF2 increased by 40, 50 and 45 per cent, respectively, on 5th day before the earthquake. The TEC anomalous distribution indicates that there was a widely TEC decrement over the epicentre with the duration of 6 hr on 15th day before the earthquake. On 5th day before the earthquake, the TEC over the epicentre increased with the amplitude of 15 TECu, and the duration exceeded 6 hr. The anomalies occurred on the side away from the equator. All TEC anomalies in these days were within the bounds of equatorial anomaly zone where should be the focal area to monitor ionospheric anomaly before strong earthquakes. The relationship between ionospheric anomalies and geomagnetic activity was detected by the cross wavelet analysis, which implied that the foF2 was not affected by the magnetic activities on 15th day and 5th day prior to the earthquake, but the TECs were partially affected by anomalous magnetic activity during some periods of 5th day prior to the earthquake.

  3. Cerium anomaly at microscale in fossils.

    Science.gov (United States)

    Gueriau, Pierre; Mocuta, Cristian; Bertrand, Loïc

    2015-09-01

    Patterns in rare earth element (REE) concentrations are essential instruments to assess geochemical processes in Earth and environmental sciences. Excursions in the "cerium anomaly" are widely used to inform on past redox conditions in sediments. This proxy resources to the specificity of cerium to adopt both the +III and +IV oxidation states, while most rare earths are purely trivalent and share very similar reactivity and transport properties. In practical terms, the level of cerium anomaly is established through elemental point quantification and profiling. All these models rely on a supposed homogeneity of the cerium oxidation state within the samples. However, this has never been demonstrated, whereas the cerium concentration can significantly vary within a sample, as shown for fossils, which would vastly complicate interpretation of REE patterns. Here, we report direct micrometric mapping of Ce speciation through synchrotron X-ray absorption spectroscopy and production of local rare earth patterns in paleontological fossil tissues through X-ray fluorescence mapping. The sensitivity of the approach is demonstrated on well-preserved fishes and crustaceans from the Late Cretaceous (ca. 95 million years (Myr) old). The presence of Ce under the +IV form within the fossil tissues is attributed to slightly oxidative local conditions of burial and agrees well with the limited negative cerium anomaly observed in REE patterns. The [Ce(IV)]/[Ce(tot)] ratio appears remarkably stable at the microscale within each fossil and is similar between fossils from the locality. Speciation maps were obtained from an original combination of synchrotron microbeam X-ray fluorescence, absorption spectroscopy, and diffraction, together with light and electron microscopy. This work also highlights the need for more systematic studies of cerium geochemistry at the microscale in paleontological contexts, in particular across fossil histologies.

  4. RADIOLOGICAL EVALUATION OF CRANIOVERTEBRAL JUNCTION ANOMALIES

    Directory of Open Access Journals (Sweden)

    Joji Reddy

    2015-08-01

    Full Text Available INTRODUCTION: Detailed discussions of the CVJ are conspicuously absent in many standard textbooks and chapters addressing the skull or cervical spine, since it lies in between these regions . CVJ anomalies are common in India subcontinent. OBJECTIVES : To outline the normal anatomy and various abnormalities of craniovertebral junction. To evaluate the most common developmental and acquired craniovertebral junction abnormalities . CRANIOMETRY AND DIAGNOSIS: Radiological evaluation of CVJ requir es identification of only a few anatomic structures. Over the years multiple lines , planes and angles have been described for assessment of CVJ relationship , initially with radiography and later with polytomography. Two lines have remained particularly use ful for evaluation of CVJ relationship with virtually any imaging modality: the chamberlain`s line and weckenheim ’ s clivus base line . Two angles also continue to be useful: the welcher basal angle and atlanto occipital joint axis angle. PATIENTS AND METHOD S: The prospective study of craniovertebral junction anomalies was carried out at Kurnool medical college , Governament general hospital Kurnool from NOV 2012 to AUG 2014. The patients are subjected to clinical evaluation and radiological evaluation. OBSERV ATIONS AND RESULTS : In our study there is male predominance with male to female ratio of 2:1 . Majority of patients are in the age group of 11 - 40 (73.26%. The commonest symptom seen is weakness of extremities ( 70% with associated numbness (50%. On clinica l examination pyramidal tract involvement noticed in 70% of cases. Basilar invagination is the most common followed by Atlantoocoipital assimilation (40% and AAD (30% . CONCLUSION : Computed tomography and magnetic resonance imaging are invalvable adjuncts to the plain radiographs in the evaluation of the craniovertebral junction anomalies. Chamberlain’s line and McGregor line are the most commonly applied craniometric measurements

  5. Can the flyby anomaly be attributed to earth-bound dark matter?

    International Nuclear Information System (INIS)

    Adler, Stephen L.

    2009-01-01

    We make preliminary estimates to assess whether the recently reported flyby anomaly can be attributed to dark matter interactions. We consider both elastic and exothermic inelastic scattering from dark matter constituents; for isotropic dark matter velocity distributions, the former decrease, while the latter increase, the final flyby velocity. The fact that the observed flyby velocity anomaly shows examples with both positive and negative signs, requires the dominance of different dark matter scattering processes along different flyby trajectories. The magnitude of the observed anomalies requires dark matter densities many orders of magnitude greater than the galactic halo density. Such a large density could result from an accumulation cascade, in which the solar system-bound dark matter density is much higher than the galactic halo density, and the earth-bound density is much higher than the solar system-bound density. We discuss a number of strong constraints on the hypothesis of a dark matter explanation for the flyby anomaly. These require dark matter to be non-self-annihilating, with the dark matter scattering cross section on nucleons much larger, and the dark matter mass much lighter, than usually assumed.

  6. Supersymmetry, quantum gauge anomalies and generalized Chern-Simons terms in chiral gauge theory

    International Nuclear Information System (INIS)

    Schmidt, Torsten

    2009-01-01

    The purpose of this thesis is to investigate the interplay of anomaly cancellation and generalized Chern-Simons terms in four-dimensional chiral gauge theory. We start with a detailed discussion of generalized Chern-Simons terms with the canellation of anomalies via the Green-Schwarz mechanism. With this at hand, we investigate the situation in general N=1 supersymmetric field theories with generalized Chern-Simons terms. Two simple consistency conditions are shown to encode strong constraints on the allowed anomalies for different types of gauge groups. In one major part of this thesis we are going to display to what extent one has to modify the existing formalism in order to allow for the cancellation of quantum gauge anomalies via the Green-Schwarz mechanism. At the end of this thesis we comment on a puzzle in the literature on supersymmetric field theories with massive tensor fields. The potential contains a term that does not arise from eliminating an auxiliary field. We clarify the origin of this term and display the relation to standard D-term potential. In an appendix it is explicitly shown how these low energy effective actions might be connected to the formulation of four-dimensional gauge theories discussed at earlier stages of this thesis. (orig.)

  7. Basal encephalocele in an adult patient presenting with minor anomalies: a case report

    Science.gov (United States)

    2014-01-01

    Introduction Basal encephalocele is rare in adults. Congenital and acquired cases have been reported with regard to the developmental mechanism, and the pathology has not been elucidated in detail. Case presentation We encountered an adult with basal encephalocele strongly suggesting congenital development because of the presence of minor anomalies: strabismus and ocular hypertelorism. The disease manifested as persistent spontaneous cerebrospinal fluid rhinorrhea and repeated meningitis in a 66-year-old Japanese man. On computed tomography, brain tissue protruded through a part of the ethmoid bone of his right anterior skull base, and it was diagnosed as transethmoidal-type basal encephalocele. Regarding his facial form, the distance between his bilateral eyeballs was large compared to his facial width, and his canthal index (defined as inner to outer inter canthal ratio × 100) was calculated as 38.5, based on which it was judged as ocular hypertelorism. In addition, his right eyeball showed strabismus. A right frontotemporal craniotomy was performed for spontaneous cerebrospinal fluid rhinorrhea, and the defective dura mater region was patched with temporal fascia. Conclusions Mild minor anomalies that require no treatment are overlooked in adults, but the presence of several anomalies increases the possibility of congenital disease. Therefore, it may be necessary to examine minor anomalies in cases of adult basal encephalocele when considering the possibility that the disease may be congenital. PMID:24468320

  8. HPNAIDM: The High-Performance Network Anomaly/Intrusion Detection and Mitigation System

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan [Northwesten University

    2013-12-05

    Identifying traffic anomalies and attacks rapidly and accurately is critical for large network operators. With the rapid growth of network bandwidth, such as the next generation DOE UltraScience Network, and fast emergence of new attacks/virus/worms, existing network intrusion detection systems (IDS) are insufficient because they: • Are mostly host-based and not scalable to high-performance networks; • Are mostly signature-based and unable to adaptively recognize flow-level unknown attacks; • Cannot differentiate malicious events from the unintentional anomalies. To address these challenges, we proposed and developed a new paradigm called high-performance network anomaly/intrustion detection and mitigation (HPNAIDM) system. The new paradigm is significantly different from existing IDSes with the following features (research thrusts). • Online traffic recording and analysis on high-speed networks; • Online adaptive flow-level anomaly/intrusion detection and mitigation; • Integrated approach for false positive reduction. Our research prototype and evaluation demonstrate that the HPNAIDM system is highly effective and economically feasible. Beyond satisfying the pre-set goals, we even exceed that significantly (see more details in the next section). Overall, our project harvested 23 publications (2 book chapters, 6 journal papers and 15 peer-reviewed conference/workshop papers). Besides, we built a website for technique dissemination, which hosts two system prototype release to the research community. We also filed a patent application and developed strong international and domestic collaborations which span both academia and industry.

  9. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.

    1995-01-01

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  10. Strong-back safety latch

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  11. Tropical Forest Backscatter Anomaly Evident in SeaWinds Scatterometer Morning Overpass Data During 2005 Drought in Amazonia

    Science.gov (United States)

    Frolking, S. E.; Milliman, T.; Palace, M. W.; Wisser, D.; Lammers, R. B.; Fahnestock, M. A.

    2010-12-01

    A severe drought occurred in many portions of Amazonia in the dry season (June-September) of 2005. We analyzed ten years (7/99-10/09) of SeaWinds active microwave Ku-band backscatter data collected over the Amazon Basin, developing a monthly climatology and monthly anomalies from that climatology in an effort to detect landscape responses to this drought. We compared these to seasonal accumulating water deficit anomalies generated using Tropical Rainfall Monitoring Mission (TRMM) precipitation data (1999-2009) and 100 mm/mo evapotranspirative demand as a water deficit threshold. There was significant interannual variability in monthly mean backscatter only for ascending (early morning) overpass data, and little interannual variability in monthly mean backscatter for descending (late afternoon) overpass data. Strong negative anomalies in both ascending-overpass backscatter and accumulating water deficit developed during July-October 2005, centered on the southwestern Amazon Basin (Acre and western Amazonas states in Brazil; Madre de Dios state in Peru; Pando state in Bolivia). During the 2005 drought, there was a strong spatial correlation between morning overpass backscatter anomalies and water deficit anomalies. We hypothesize that as the drought persisted over several months, the forest canopy was increasingly unable to recover full leaf moisture content over night, and the early morning overpass backscatter data became anomalously low. This is the first reporting of tropical wet forest seasonal drought detection by active microwave scatterometry.

  12. Imaging evaluation of fetal vascular anomalies

    International Nuclear Information System (INIS)

    Calvo-Garcia, Maria A.; Kline-Fath, Beth M.; Koch, Bernadette L.; Laor, Tal; Adams, Denise M.; Gupta, Anita; Lim, Foong-Yen

    2015-01-01

    Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification. (orig.)

  13. Structure and Transport Anomalies in Soft Colloids

    KAUST Repository

    Srivastava, Samanvaya

    2013-04-01

    Anomalous trends in nanoparticle correlation and motion are reported in soft nanoparticle suspensions using static and dynamic x-ray scattering measurements. Contrary to normal expectations, we find that particle-particle correlations decrease and particle dynamics become faster as volume fraction rises above a critical particle loading associated with overlap. Our observations bear many similarities to the cascade of structural and transport anomalies reported for complex, network forming molecular fluids such as water, and are argued to share similar physical origins. © 2013 American Physical Society.

  14. Residual generator for cardiovascular anomalies detection

    KAUST Repository

    Belkhatir, Zehor

    2014-06-01

    This paper discusses the possibility of using observer-based approaches for cardiovascular anomalies detection and isolation. We consider a lumped parameter model of the cardiovascular system that can be written in a form of nonlinear state-space representation. We show that residuals that are sensitive to variations in some cardiovascular parameters and to abnormal opening and closure of the valves, can be generated. Since the whole state is not easily available for measurement, we propose to associate the residual generator to a robust extended kalman filter. Numerical results performed on synthetic data are provided.

  15. Mouse models for understanding human developmental anomalies

    International Nuclear Information System (INIS)

    Generoso, W.M.

    1989-01-01

    The mouse experimental system presents an opportunity for studying the nature of the underlying mutagenic damage and the molecular pathogenesis of this class of anomalies by virtue of the accessibility of the zygote and its descendant blastomeres. Such studies could contribute to the understanding of the etiology of certain sporadic but common human malformations. The vulnerability of the zygotes to mutagens as demonstrated in the studies described in this report should be a major consideration in chemical safety evaluation. It raises questions regarding the danger to human zygotes when the mother is exposed to drugs and environmental chemicals

  16. Atomki anomaly and the Secluded Dark Sector

    OpenAIRE

    Yamamoto Yasuhiro

    2018-01-01

    The Atomiki anomaly can be interpreted as a new light vector boson. If such a new particle exists, it could be a mediator between the Standard Model sector and the dark sector including the dark matter. We discussed some simple effective models with these particles. In the models, the secluded dark matter models are good candidates to satisfy the thermal relic abundance. In particular, we found that the dark matter self-interaction can be large enough to solve the small scale structure puzzle...

  17. Mouse models for understanding human developmental anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Generoso, W.M.

    1989-01-01

    The mouse experimental system presents an opportunity for studying the nature of the underlying mutagenic damage and the molecular pathogenesis of this class of anomalies by virtue of the accessibility of the zygote and its descendant blastomeres. Such studies could contribute to the understanding of the etiology of certain sporadic but common human malformations. The vulnerability of the zygotes to mutagens as demonstrated in the studies described in this report should be a major consideration in chemical safety evaluation. It raises questions regarding the danger to human zygotes when the mother is exposed to drugs and environmental chemicals.

  18. Anomalies in chiral W--gravity

    International Nuclear Information System (INIS)

    Carvalho, Marcelo; Vilar, Luiz Claudio Queiroz; Sorella, S.P.

    1994-01-01

    W-algebras are an extension of the Virasoro algebra. They describe the commutation relations between the components of the stress-energy tensor (T ++ ,T -- ) and the currents (W ++++... , W ----... ) of higher spin. Among the various W-algebras considered in the recent literature, the so-called W 3 -algebra plays a rather special role, due to the fact that it has a simple field theory realization. The corresponding field model, known as W 3 -gravity, yields a generalization of the usual bosonic string action. In this work, anomalies in chiral W--gravity are studied

  19. Imaging evaluation of fetal vascular anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Calvo-Garcia, Maria A.; Kline-Fath, Beth M.; Koch, Bernadette L.; Laor, Tal [MLC 5031 Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Adams, Denise M. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics and Hemangioma and Vascular Malformation Center, Cincinnati, OH (United States); Gupta, Anita [Cincinnati Children' s Hospital Medical Center, Department of Pathology, Cincinnati, OH (United States); Lim, Foong-Yen [Cincinnati Children' s Hospital Medical Center, Pediatric Surgery and Fetal Center of Cincinnati, Cincinnati, OH (United States)

    2015-08-15

    Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification. (orig.)

  20. Atmospheric Methane Growth Anomalies, 2007 - Present

    Science.gov (United States)

    Lowry, D.; Dlugokencky, E. J.; Fisher, R. E.; Nisbet, E. G.; Lanoiselle, M.; France, J.

    2012-12-01

    Several marked growth anomalies in atmospheric methane have occurred since 2007. In particular there has been sustained growth in methane in the Southern Hemisphere. This southern growth anomaly is among the larger excursions in the global methane record so far occurring in the 21st century, yet in contrast to Arctic emission, it has had little attention. The increase in methane began in 2007 and continued through early-2012. In the zonal average from the Equator to 30°S, annual increases reached 7.9 ppb/yr in 2007, remained at 7.0 ppb/yr in 2008, fell to around 2.5 ppb/yr in 2009, then increased to 7.9 ppb/yr in 2010. To consider one specific site, recent data from Ascension Island (which samples South Atlantic air almost exclusively) suggests growth of ~11 ppb/yr from July 2010 to July 2011 (winter to winter) falling to 8 ppb/yr over Jan 2011 - Jan 2012 (summer to summer). Isotopic data for 2011 show 13C enrichments and depletions that may suggest inputs from tropical / subtropical fire and wetland sources, respectively. Despite the size of the southern anomaly, there has been virtually no discussion of its causes. Several possibilities exist: some or all may have occurred: 1) that methane emission from southern wetland (late wet season) and fire (dry season) sources increased sharply during this period; 2) that the southern OH methane sink has decreased; 3) that changes in atmospheric circulation patterns have increased inter-hemispheric transport. It is possible that a major factor was high La Nina rainfall in key areas draining into wetlands in southern tropical Africa and Latin America. Tropical methane sources emit roughly 200 Tg methane annually to the atmosphere, nearly two-fifths of the global budget. Thus changes in tropical sources, if sustained on this scale, can have global significance. However the observational network generally is so sparse in the tropics that identifying causes of methane growth events is more akin to guesswork than evidence

  1. Magnetic resonance imaging of Muellerian duct anomalies in children

    International Nuclear Information System (INIS)

    Li, Yi; Phelps, Andrew; Zapala, Matthew A.; MacKenzie, John D.; MacKenzie, Tippi C.; Courtier, Jesse

    2016-01-01

    Muellerian duct anomalies encompass a wide variety of disorders resulting from abnormalities in the embryological development of the Muellerian ducts. In the prepubertal pediatric population, Muellerian duct anomalies are often incidental findings on studies obtained for other reasons. The onset of menses can prompt more clinical symptoms. Proper characterization of Muellerian duct anomalies is important because these anomalies can affect the development of gynecological disorders as well as fertility. Muellerian duct anomalies also carry a high association with other congenital anomalies, particularly renal abnormalities. MRI is widely considered the best modality for assessing Muellerian duct anomalies; it provides multiplanar capability, clear anatomical detail and tissue characterization without ionizing radiation. MRI allows for careful description of Muellerian duct anomalies, often leading to classification into the most widely accepted classification system for Muellerian duct anomalies. This system, developed by the American Society of Reproductive Medicine, includes seven subtypes: uterine agenesis/hypoplasia, unicornuate, didelphys, bicornuate, septate, arcuate, and diethylstilbestrol (DES) drug-related uterus. In cases of complex anomalies that defy classification, MRI allows detailed depiction of all components of the anatomical abnormality, allowing for proper management and surgical planning. (orig.)

  2. Radon anomalies in ground water before earthquakes in Tokyo

    International Nuclear Information System (INIS)

    Saito, Masaaki

    1992-01-01

    Radon contents in ground waters in Tokyo have been measured since 1976. The correlation between earthquake and radon anomaly will be evaluated easily, when both earthquakes and radon anomalies are a few. In addition, the high reliability of the correlation will be obtained, if an earthquake and an anomaly occur at almost same time. The six earthquakes occurred in 1976∼1990 were chosen based on the magnitude (≥6.0) and the epicentral distance (<100 km). Radon anomalies shortly before the six earthquakes were investigated at the stations where few anomalies have been detected. Anomalies which can be considered to relate with earthquakes appeared near around the dates of the Ibaraki-Chiba (1985) and the Yamanashi-Kanagawa (1983) earthquakes. The anomalies appeared in 6 d before ∼4 d after the earthquakes, and no other anomalies had appeared in over 600 d before the earthquakes. Then it is presumed that these anomalies would be earthquake precursors. The anomalies were found at the stations distributed in 50∼70 km epicentral distances and on the compress quadrants of the earthquake mechanism. (author)

  3. Annual temperature anomaly trends correlate with coral reef trajectory across the Pacific

    Science.gov (United States)

    Riegl, B. M.; Wieters, E.; Bruckner, A.; Purkis, S.

    2013-05-01

    The future survival of coral reefs depends on the envelope of critical climatic conditions determining the severity of impacts on the ecosystem. While coral health is strongly determined by extreme heat events, that lead to bleaching and often death, chronic "heat loading" may also disadvantage corals by making them more susceptible to, for example, diseases. On the other hand, it has been shown that coral living in hotter areas have higher bleaching thresholds and may be affected by less mortality at extreme events. This level at which heat anomalies lead to coral mortality varies widely across oceans, from ~31 deg C across the Caribbean to ~32 deg C in the Great Barrier Reef to 37.5 deg C in the Persian/Arabian Gulf. Thus, there clearly exists local adaptation and the extremes required to kill reefs strongly vary among regions. This could be be interpreted as suggesting that as long as bleaching temperatures are not reached, increased overall heat content expressed by a positive annual thermal anomaly, might actually foster coral resilience. Is there evidence for or against such an argument? Bleaching events have been occurring worldwide with variable recurrence and variable subsequent recovery. Despite demonstrated adaptation to higher-than-usual mean summer temperatures, reefs in the Arabian Gulf and the Red Sea are on a declining trajectory. This coincides with consistent warming in the region. Mean annual anomalies of ocean temperature (since 1870) and atmospheric temperatures (since 1950) increase throughout the region. Since 1994 (Red Sea) and 1998 (southern Arabian Gulf) all mean annual anomalies have been positive and this period has coincided with repeated, severe bleaching events. In the Eastern Pacific (Galapagos and Easter Island), the trend of mean annual temperature anomalies has been declining and coral cover has been increasing. Thus, trends in coral cover and mean annual anomaly are negatively correlated in both regions. Despite strong impacts

  4. Hydrogeophysical exploration of three-dimensional salinity anomalies with the time-domain electromagnetic method (TDEM)

    Science.gov (United States)

    Bauer-Gottwein, Peter; Gondwe, Bibi N.; Christiansen, Lars; Herckenrath, Daan; Kgotlhang, Lesego; Zimmermann, Stephanie

    2010-01-01

    SummaryThe time-domain electromagnetic method (TDEM) is widely used in groundwater exploration and geological mapping applications. TDEM measures subsurface electrical conductivity, which is strongly correlated with groundwater salinity. TDEM offers a cheap and non-invasive option for mapping saltwater intrusion and groundwater salinization. Traditionally, TDEM data is interpreted using one-dimensional layered-earth models of the subsurface. However, most saltwater intrusion and groundwater salinization phenomena are characterized by three-dimensional anomalies. To fully exploit the information content of TDEM data in this context, three-dimensional modeling of the TDEM response is required. We present a finite-element solution for three-dimensional forward modeling of TDEM responses from arbitrary subsurface electrical conductivity distributions. The solution is benchmarked against standard layered-earth models and previously published three-dimensional forward TDEM modeling results. Concentration outputs from a groundwater flow and salinity transport model are converted to subsurface electrical conductivity using standard petrophysical relationships. TDEM responses over the resulting subsurface electrical conductivity distribution are generated using the three-dimensional TDEM forward model. The parameters of the hydrodynamic model are constrained by matching observed and simulated TDEM responses. As an application example, a field dataset of ground-based TDEM data from an island in the Okavango Delta is presented. Evaporative salt enrichment causes a strong salinity anomaly under the island. We show that the TDEM field data cannot be interpreted in terms of standard one-dimensional layered-earth TDEM models, because of the strongly three-dimensional nature of the salinity anomaly. Three-dimensional interpretation of the field data allows for detailed and consistent mapping of this anomaly and makes better use of the information contained in the TDEM field

  5. Analysis of genitourinary anomalies in patients with VACTERL (Vertebral anomalies, Anal atresia, Cardiac malformations, Tracheo-Esophageal fistula, Renal anomalies, Limb abnormalities) association.

    Science.gov (United States)

    Solomon, Benjamin D; Raam, Manu S; Pineda-Alvarez, Daniel E

    2011-06-01

    The goal of this study was to describe a novel pattern of genitourinary (GU) anomalies in VACTERL association,which involves congenital anomalies affecting the vertebrae,anus, heart, trachea and esophagus, kidneys, and limbs.We collected clinical data on 105 patients diagnosed with VACTERL association and analyzed a subset of 89 patients who met more stringent inclusion criteria. Twenty-one percent of patients have GU anomalies, which are more severe (but not more frequent) in females. Anomalies were noted in patients without malformations affecting the renal, lower vertebral, or lower gastrointestinal systems. There should be a high index of suspicion for the presence of GU anomalies even in patients who do not have spatially similar malformations.

  6. Titanium: light, strong, and white

    Science.gov (United States)

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  7. Thermal Radiation Anomalies Associated with Major Earthquakes

    Science.gov (United States)

    Ouzounov, Dimitar; Pulinets, Sergey; Kafatos, Menas C.; Taylor, Patrick

    2017-01-01

    Recent developments of remote sensing methods for Earth satellite data analysis contribute to our understanding of earthquake related thermal anomalies. It was realized that the thermal heat fluxes over areas of earthquake preparation is a result of air ionization by radon (and other gases) and consequent water vapor condensation on newly formed ions. Latent heat (LH) is released as a result of this process and leads to the formation of local thermal radiation anomalies (TRA) known as OLR (outgoing Longwave radiation, Ouzounov et al, 2007). We compare the LH energy, obtained by integrating surface latent heat flux (SLHF) over the area and time with released energies associated with these events. Extended studies of the TRA using the data from the most recent major earthquakes allowed establishing the main morphological features. It was also established that the TRA are the part of more complex chain of the short-term pre-earthquake generation, which is explained within the framework of a lithosphere-atmosphere coupling processes.

  8. Effective Tolman temperature induced by trace anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Eune, Myungseok [Sangmyung University, Department of Civil Engineering, Cheonan (Korea, Republic of); Gim, Yongwan [Sogang University, Department of Physics, Seoul (Korea, Republic of); Sogang University, Research Institute for Basic Science, Seoul (Korea, Republic of); Kim, Wontae [Sogang University, Department of Physics, Seoul (Korea, Republic of)

    2017-04-15

    Despite the finiteness of stress tensor for a scalar field on the four-dimensional Schwarzschild black hole in the Israel-Hartle-Hawking vacuum, the Tolman temperature in thermal equilibrium is certainly divergent on the horizon due to the infinite blue-shift of the Hawking temperature. The origin of this conflict is due to the fact that the conventional Tolman temperature was based on the assumption of a traceless stress tensor, which is, however, incompatible with the presence of the trace anomaly responsible for the Hawking radiation. Here, we present an effective Tolman temperature which is compatible with the presence of the trace anomaly by using the modified Stefan-Boltzmann law. Eventually, the effective Tolman temperature turns out to be finite everywhere outside the horizon, and so an infinite blue-shift of the Hawking temperature at the event horizon does not appear any more. In particular, it is vanishing on the horizon, so that the equivalence principle is exactly recovered at the horizon. (orig.)

  9. Effective Tolman temperature induced by trace anomaly

    International Nuclear Information System (INIS)

    Eune, Myungseok; Gim, Yongwan; Kim, Wontae

    2017-01-01

    Despite the finiteness of stress tensor for a scalar field on the four-dimensional Schwarzschild black hole in the Israel-Hartle-Hawking vacuum, the Tolman temperature in thermal equilibrium is certainly divergent on the horizon due to the infinite blue-shift of the Hawking temperature. The origin of this conflict is due to the fact that the conventional Tolman temperature was based on the assumption of a traceless stress tensor, which is, however, incompatible with the presence of the trace anomaly responsible for the Hawking radiation. Here, we present an effective Tolman temperature which is compatible with the presence of the trace anomaly by using the modified Stefan-Boltzmann law. Eventually, the effective Tolman temperature turns out to be finite everywhere outside the horizon, and so an infinite blue-shift of the Hawking temperature at the event horizon does not appear any more. In particular, it is vanishing on the horizon, so that the equivalence principle is exactly recovered at the horizon. (orig.)

  10. Axial gravity, massless fermions and trace anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Bonora, L. [International School for Advanced Studies (SISSA), Trieste (Italy); KEK, Tsukuba (Japan). KEK Theory Center; INFN, Sezione di Trieste (Italy); Cvitan, M.; Giaccari, S.; Stemberga, T. [Zagreb Univ. (Croatia). Dept. of Physics; Prester, P.D. [Rijeka Univ. (Croatia). Dept. of Physics; Pereira, A.D. [UERJ-Univ. Estadual do Rio de Janeiro (Brazil). Dept. de Fisica Teorica; UFF-Univ. Federal Fluminense, Niteroi (Brazil). Inst. de Fisica

    2017-08-15

    This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms and using dimensional regularization, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones. (orig.)

  11. Cochleovestibular anomalies in children with cholesteatoma.

    Science.gov (United States)

    Propst, Evan J; Blaser, Susan; Trimble, Keith; James, Adrian; Friedberg, Jacob; Papsin, Blake C

    2008-03-01

    To describe the cochleovestibular apparatus on computed tomography (CT) imaging in patients with cholesteatoma. We asked whether cochleovestibular anomalies coexist in individuals with cholesteatoma. Randomized, controlled, prospective measurement. A database search yielded 145 children with cholesteatoma: 31 met inclusion criteria by not having sensorineural hearing loss, not having an associated syndrome, and having digitally stored temporal bone CT imaging available. Prospective measurement of 31 individuals (62 ears) with unilateral cholesteatoma and 32 normally hearing nonsyndromic controls (64 ears) was performed by a neuroradiologist blinded to the study objective. Twenty-six temporal bone aspects on axial imaging were evaluated (16 measurement, 10 calculated from measurement). The cholesteatoma group had a larger endolymphatic fossa and vestibular aqueduct, and there was a trend for the lateral semicircular canal vestibule to be smaller as compared with controls. Subgroup analysis revealed a gradient in prevalence of these findings being most common in the congenital cholesteatoma group, intermediate in the acquired cholesteatoma group, and least common in controls. There were no differences in measurements between ears with cholesteatoma and contralateral disease-free temporal bones. Children with cholesteatoma have abnormal vestibular anatomy. The gradient in prevalence of these findings may suggest a relationship between congenital and acquired cholesteatoma. These may include a generalized temporal bone anomaly that predisposes to cholesteatoma formation, or a third variable such as genetic mutation may predispose to both anomalous cochleovestibular formation and cholesteatoma.

  12. [Laparoscopic management of symptomatic urachal anomalies].

    Science.gov (United States)

    Sánchez-Ismayel, Alexis; Cruz-González, Germán; Sánchez, Renata; Sánchez-Salas, Rodolfo; Rodríguez, Omaira; Sanabria, Erasmo; Sotelo, Rene; Sánchez-Salas, Rafael E

    2009-03-01

    Acquired urachal anomalies are a rare pathology. Gold-standard treatment for this clinical situation remains the resection of the urachus in its entire tract with or without partial resection of the bladder. Our aim is to up-date authors's experience in the minimally invasive surgical treatment of acquired urachal disease. From 2001 to 2007, 14 patients were operated for acquired urachal disease at our institution. A three portal technique previously described by the authors was employed. The diagnosis of acquired uracal disease was confirmed in all cases and the resection of the urachus in its entire tract performed in cephalocaudal direction onto the bladder. Operative and demographic data was prospectively collected and analysis retrospectively performed. Mean operative time was 63 minutes (45,110), minimal blood loss, and no conversions to open surgery or perioperative complications were verified. The majority of the patients were discharged in the first 24 hours. At a follow-up of 22 months no recurrences of urachal pathology recurrences have been verified. Laparoscopy plays a significant role in the management of symptomatic urachus anomalies. It allows objective confirmation of clinical diagnosis and adequate resection of the urachus in a safe and efficient fashion, while providing the well-known advantages of minimally acces surgery. Preoperative evaluation work-up has minimal impact of therapeutical decision.

  13. Ebstein's Anomaly: Anatomo-echocardiographic correlation

    Directory of Open Access Journals (Sweden)

    Keirns Candace

    2007-11-01

    Full Text Available Abstract Objective The aim of this investigation is to demonstrate that in Ebstein's Anomaly (EA the right ventricle (RV is affected in its three portions and to establish an anatomoechocardiographic correlation between the anatomic features and the equivalent echocardiographic images. Methods Thirty hearts with EA were studied. The alterations of each portions of the RV were described. Fifty adult patients with this anomaly were studied by echocardiography. Results Anatomy: All hearts had atrial situs solitus, 27 had concordant atrioventricular connection and 3 discordant, of these 2 had transposition of the great arteries (TGA and one double outlet right ventricle (DORV. The degree of tricuspid valve (TV displacement showed a spectrum from I to III. The inlet of the RV was markedly thin in 27. The trabecular portion had multiples muscular bands in all. The outlet portion was dilated in 20 and stenotic in 5. In 25 atrial septal defects were found. Echocardiography: All patients had atrial situs solitus, 42 with concordant atrioventricular connection and 8 with discordant, of these last patients 5 had TGA and 3 DORV. The degree of TV displacement varied from I to III. The inlet of RV was markedly thin in 42. The trabecular portion had muscular bands in 45. The outlet portion was dilated in 31 and stenotic in 11. In 30 atrial septal defects were found. Conclusion The EA affects the whole RV and the anatomoechocardiographic correlation provides an appropriate understanding of echocardiographic images in terms of a precise diagnosis, therapeutic decisions and prognosis.

  14. Bronchial arteries: anatomy, function, hypertrophy, and anomalies.

    Science.gov (United States)

    Walker, Christopher M; Rosado-de-Christenson, Melissa L; Martínez-Jiménez, Santiago; Kunin, Jeffrey R; Wible, Brandt C

    2015-01-01

    The two main sources of blood supply to the lungs and their supporting structures are the pulmonary and bronchial arteries. The bronchial arteries account for 1% of the cardiac output but can be recruited to provide additional systemic circulation to the lungs in various acquired and congenital thoracic disorders. An understanding of bronchial artery anatomy and function is important in the identification of bronchial artery dilatation and anomalies and the formulation of an appropriate differential diagnosis. Visualization of dilated bronchial arteries at imaging should alert the radiologist to obstructive disorders that affect the pulmonary circulation and prompt the exclusion of diseases that produce or are associated with pulmonary artery obstruction, including chronic infectious and/or inflammatory processes, chronic thromboembolic disease, and congenital anomalies of the thorax (eg, proximal interruption of the pulmonary artery). Conotruncal abnormalities, such as pulmonary atresia with ventricular septal defect, are associated with systemic pulmonary supply provided by aortic branches known as major aortopulmonary collaterals, which originate in the region of the bronchial arteries. Bronchial artery malformation is a rare left-to-right or left-to-left shunt characterized by an anomalous connection between a bronchial artery and a pulmonary artery or a pulmonary vein, respectively. Bronchial artery interventions can be used successfully in the treatment of hemoptysis, with a low risk of adverse events. Multidetector computed tomography helps provide a vascular road map for the interventional radiologist before bronchial artery embolization. RSNA, 2015

  15. Axions and the strong CP problem in M theory

    International Nuclear Information System (INIS)

    Choi, K.

    1997-01-01

    We examine the possibility that the strong CP problem is solved by string-theoretic axions in the strong-coupling limit of the E 8 xE 8 ' heterotic string theory (M theory). We first discuss some generic features of gauge kinetic functions in compactified M theory, and examine in detail the axion potential induced by the explicit breakings other than the QCD anomaly of the nonlinear U(1) PQ symmetries of string-theoretic axions. It is argued based on supersymmetry and discrete gauge symmetries that if the compactification radius is large enough, there can be a U(1) PQ symmetry whose breaking other than the QCD anomaly, whatever its microscopic origin is, is suppressed enough for the axion mechanism to work. Phenomenological viability of such a large radius crucially depends upon the quantized coefficients in gauge kinetic functions. We note that the large radius required for the axion mechanism is viable only in a limited class of models. For instance, for compactifications on a smooth Calabi-Yau manifold with a vanishing E 8 ' field strength, it is viable only when the quantized flux of the antisymmetric tensor field in M theory has a minimal nonzero value. It is also stressed that this large compactification radius allows the QCD axion in M theory to be cosmologically viable in the presence of a late time entropy production. copyright 1997 The American Physical Society

  16. Analysis on Space Environment from the Anomalies of Geosynchronous Satellites

    Directory of Open Access Journals (Sweden)

    Jaejin Lee

    2009-12-01

    Full Text Available While it is well known that space environment can produce spacecraft anomaly, defining space environment effects for each anomalies is difficult. This is caused by the fact that spacecraft anomaly shows various symptoms and reproducing it is impossible. In this study, we try to find the conditions of when spacecraft failures happen more frequently and give satellite operators useful information. Especially, our study focuses on the geosynchronous satellites which cost is high and required high reliability. We used satellite anomaly data given by Satellite News Digest which is internet newspaper providing space industry news. In our analysis, 88 anomaly cases occurred from 1997 to 2008 shows bad corelation with Kp index. Satellite malfunctions were likely to happen in spring and fall and in local time from midnight to dawn. In addition, we found the probability of anomaly increase when high energy electron flux is high. This is more clearly appeared in solar minimum than maximum period.

  17. [Occlusal anomalies in the deciduous and mixed bites].

    Science.gov (United States)

    Legovic, M; Mady, L

    1998-01-01

    In 311 examines (177 boys and 134 girls) with primary dentition and 535 examinees (285 boys and 250 girls) with mixed dentition in Istria--Croatia, the frequency of orthodontic and occlusive anomalies in regard of space plane and premature extraction of c, m1 and m2 are investigated. The orthodontic anomalies are defected in 46.95%, premature loss in 11.25% and occlusive anomalies in 40.85% of examinees with primary dentition, while in mixed dentition the 58.69% of examinees have orthodontic anomaly, the 17.20% premature loss and the 48.97% of examinees have occlusal anomaly. In both phases of dentition the most frequent are occlusive anomalies in the following planes: sagittal, vertical and sagittal-vertical.

  18. Maternal uniparental disomy of chromosome 16 and body stalk anomaly.

    Science.gov (United States)

    Chan, Y; Silverman, N; Jackson, L; Wapner, R; Wallerstein, R

    2000-10-02

    We report on a fetus with placental trisomy 16, maternal uniparental disomy (UPD), and body stalk anomaly. Body stalk anomaly is a rare, fatal developmental abnormality consisting of a defective abdominal wall with abdominal organs in a sac outside the abdominal cavity covered by amnion adherent to the placenta with absence or severe shortness of the umbilical cord. Trisomy 16 was identified in the placenta in all cells. Amniocentesis was karyotypically normal. Parental origin studies showed maternal UPD for chromosome 16 in post-termination fetal tissue. The cause of the body stalk anomaly is not clearly defined. There are no other reports of placental karyotype or UPD investigations with body stalk anomaly. To our knowledge, this is the first report of placental trisomy 16, UPD in fetus, and body stalk anomaly, suggesting placental insufficiency or imprinting effects as cause of this anomaly. Am. J. Med. Genet. 94:284-286, 2000. Copyright 2000 Wiley-Liss, Inc.

  19. Prevalence and Distribution of Developmental Dental Anomalies in Pediatric Patients

    Directory of Open Access Journals (Sweden)

    Merve Erkmen Almaz

    2017-08-01

    Full Text Available Objective: The objective of this study was to evaluate the prevalence of dental anomalies in paediatric patients attending the Department of Paediatric Dentistry, Kırıkkale University Faculty of Dentistry. Materials and Methods: The study consisted a sample of 9173 patients, aged between 0-15 years, referred to our clinic between 1 August 2011-1 August 2012. The patients were examined clinically and radiographically in terms of the number, size, shape, structure and color anomalies. Results: One hundred sixty six children (1.8% were found to have developmental dental anomalies. The most frequently observed anomalies were congenitally missing teeth (0.52% and supernumerary teeth (0.27%. Anomalies such as dens invaginatus (0.03%, dentinogenesis imperfecta (0.02% and dilaceration (0.02% were encountered more rarely. Conclusion: Early diagnosis and determination of the prevalence of dental anomalies in children is important in the treatment planning.

  20. Major congenital anomalies in babies born with Down syndrome

    DEFF Research Database (Denmark)

    Morris, Joan K; Garne, Ester; Wellesley, Diana

    2014-01-01

    Previous studies have shown that over 40% of babies with Down syndrome have a major cardiac anomaly and are more likely to have other major congenital anomalies. Since 2000, many countries in Europe have introduced national antenatal screening programs for Down syndrome. This study aimed...... to determine if the introduction of these screening programs and the subsequent termination of prenatally detected pregnancies were associated with any decline in the prevalence of additional anomalies in babies born with Down syndrome. The study sample consisted of 7,044 live births and fetal deaths with Down...... syndrome registered in 28 European population-based congenital anomaly registries covering seven million births during 2000-2010. Overall, 43.6% (95% CI: 42.4-44.7%) of births with Down syndrome had a cardiac anomaly and 15.0% (14.2-15.8%) had a non-cardiac anomaly. Female babies with Down syndrome were...

  1. Symmetric scaling properties in global surface air temperature anomalies

    Science.gov (United States)

    Varotsos, Costas A.; Efstathiou, Maria N.

    2015-08-01

    We have recently suggested "long-term memory" or internal long-range correlation within the time-series of land-surface air temperature (LSAT) anomalies in both hemispheres. For example, an increasing trend in the LSAT anomalies is followed by another one at a different time in a power-law fashion. However, our previous research was mainly focused on the overall long-term persistence, while in the present study, the upward and downward scaling dynamics of the LSAT anomalies are analysed, separately. Our results show that no significant fluctuation differences were found between the increments and decrements in LSAT anomalies, over the whole Earth and over each hemisphere, individually. On the contrary, the combination of land-surface air and sea-surface water temperature anomalies seemed to cause a departure from symmetry and the increments in the land and sea surface temperature anomalies appear to be more persistent than the decrements.

  2. On Certain Conceptual Anomalies in Einstein's Theory of Relativity

    OpenAIRE

    Crothers S. J.

    2008-01-01

    There are a number of conceptual anomalies occurring in the Standard exposition of Einstein’s Theory of Relativity. These anomalies relate to issues in both mathematics and in physics and penetrate to the very heart of Einstein’s theory. This paper reveals and amplifies a few such anomalies, including the fact that Einstein’s field equations for the so-called static vacuum configuration, R = 0 , violates his Principle of Equiv- alence, and is therefore ...

  3. Anomaly Detection and Visualization of School Electricity Consumption Data

    OpenAIRE

    Cui, Wenqiang; Wang, Hao

    2017-01-01

    Anomaly detection has been widely used in a variety of research and application domains, such as network intrusion detection, insurance/credit card fraud detection, health-care informatics, industrial damage detection, image processing and novel topic detection in text mining. In this paper, we focus on remote facilities management that identifies anomalous events in buildings by detecting anomalies in building energy data. We have investigated five models to detect anomalies in the school el...

  4. A sign on CT that predicts a hazardous ureteral anomaly

    Directory of Open Access Journals (Sweden)

    E.S. Allam

    2016-01-01

    Conclusion: Anterior deviation of the ureter in its mid-course appears to predict inguinoscrotal herniation of the ureter. This finding is a sensitive predictor and should raise concern for this anomaly in the appropriate clinical setting. It is not entirely specific as morbid obesity and congenital anomalies may result in a similar imaging appearance. We believe that this association has not been reported previously. Awareness of this anomaly can have significant operative implications.

  5. Anomaly cancellation condition in abelian lattice gauge theories

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi

    1999-11-01

    We analyze the general solution of the Wess-Zumino consistency condition in abelian lattice gauge theories, without taking the classical continuum limit. We find that, if the anomaly density is a local pseudo-scalar field on the lattice, the non-trivial anomaly is always proportional to the anomaly coefficient in the continuum theory. The possible extension of this result to non-abelian theories is briefly discussed. (author)

  6. Anomaly detection based on zero appearances in subspaces

    OpenAIRE

    Pang, Guansong

    2017-01-01

    Anomaly detection is regarded as one of the most important tasks in data mining due to its wide application in various domains, such as finance, information security, healthcare and earth science. With advancements in data collection techniques, the volume and dimensionality of anomaly detection data sets increase explosively, and diverse attribute types occur within these data sets. Also, in many data sets, anomalies can be detected in some attributes only, while other attributes are irrelev...

  7. Modulation of ENSO evolution by strong tropical volcanic eruptions

    Science.gov (United States)

    Wang, Tao; Guo, Dong; Gao, Yongqi; Wang, Huijun; Zheng, Fei; Zhu, Yali; Miao, Jiapeng; Hu, Yongyun

    2017-11-01

    The simulated responses of the El Niño-Southern Oscillation (ENSO) to volcanic forcings are controversial, and some mechanisms of these responses are not clear. We investigate the impacts of volcanic forcing on the ENSO using a long-term simulation covering 1400-1999 as simulated by the Bergen Climate Model (BCM) and a group of simulations performed with the Community Atmosphere Model version 4.0 (CAM4) and the BCM's ocean component Miami Isopycanic Coordinated Ocean Model (MICOM). The analysis of the long-term BCM simulation indicates that ENSO has a negative-positive-negative response to strong tropical volcanic eruptions (SVEs), which corresponds to the different stages of volcanic forcing. In the initial forcing stage, a brief and weak La Niña-like response is caused by the cooling along the west coast of the South American continent and associated enhancement of the trade winds. In the peak forcing stage, westerly wind anomalies are excited by both reduced east-west sea level pressure gradients and weakened and equatorward shifted tropical convergence zones. These westerly wind anomalies extend to the equatorial eastern Pacific, leading to an El Niño-like response. At the same time, easterly wind anomalies west of 120°E and strong cooling effects can promote a discharged thermocline state and excite an upwelling Kelvin wave in the western Pacific. In the declining forcing stage, forced by the recovered trade winds, the upwelling Kelvin wave propagates eastward and reaches the equatorial eastern Pacific. Through the Bjerknes feedback, a strong and temporally extended La Niña-like response forms. Additional CAM4 simulations suggest a more important role of the surface cooling over the Maritime Continent and surrounding ocean in shaping the westerly wind anomalies over the equatorial central-eastern Pacific and the easterly wind anomalies west of 120° E, which are key to causing the El Niño-like responses and subsequent La Niña-like responses

  8. Recent developments in the path integral approach to anomalies

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo.

    1986-08-01

    After a brief summary of the path integral approach to anomalous identities, some of the recent developments in this approach are discussed. The topics discussed include (i) Construction of the effective action by means of the covariant current, (ii) Gauss law constraint in anomalous gauge theories, (iii) Path integral approach to anomalies in superconformal transformations, (iv) Conformal and ghost number anomalies in string theory in analogy with the instanton calculation, (v) Covariant local Lorentz anomaly and its connection with the mathematical construction of the consistent anomaly. (author)

  9. Congenital anomalies of the coronary sinus: A pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Eun; Kwon, Se Hwan; Oh, Joo Hyeong [Dept. of Radiology, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

    2013-07-15

    Congenital anomalies involving the coronary sinus (CS) tend to receive relatively little attention because they rarely cause clinical symptoms or disturbances of cardiac function. However, as imaging modalities have been developed over time, the detailed anatomy of the heart, including CS anomalies, can now be evaluated more precisely. The purpose of this pictorial review is to illustrate multi-detector computed tomography findings of various congenital anomalies of the CS. The cardiac venous system and its embryologic development are also described in detail to familiarize radiologists with various congenital anomalies of the CS.

  10. Unsupervised Anomaly Detection for Liquid-Fueled Rocket Prop...

    Data.gov (United States)

    National Aeronautics and Space Administration — Title: Unsupervised Anomaly Detection for Liquid-Fueled Rocket Propulsion Health Monitoring. Abstract: This article describes the results of applying four...

  11. Physical Modeling for Anomaly Diagnostics and Prognostics, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop developed an innovative, model-driven anomaly diagnostic and fault characterization system for electromechanical actuator (EMA) systems to mitigate...

  12. FOETAL ULTRASOUND - NEUROECTODERMAL ANOMALIES IN RURAL PREGNANT WOMEN

    Directory of Open Access Journals (Sweden)

    Mala Venkata

    2016-06-01

    Full Text Available BACKGROUND A prospective clinical study to know the various types of congenital Neuroectodermal Anomalies on obstetric Ultrasound, in rural pregnant women. To reduce the maternal morbidity and mortality by early detection of these Congenital Neuroectodermal Anomalies. To calculate the incidence and prevalence of different types of Congenital Neuroectodermal Anomalies, in these rural pregnant women. To assist the obstetrician in taking decisions regarding the termination or continuation of the pregnancy in relation to the type of malformation and its prognosis. METHODS A prospective clinical study of Congenital Neuroectodermal Anomalies in 22,000 rural pregnant women coming to the Santhiram Medical College, Radiology Department for a routine obstetric scan. 44 cases of neuroectodermal anomalies were detected out of the 22000 cases, within an incidence of 2 per 1000 cases. Approximately 1 in every 500 cases showed an anomaly. RESULTS The most common lesions detected were hydrocephalus, and spina bifida followed by anencephaly. Association of these lesions with consanguinity, previous history of similar anomaly and intake of iron and folic acid tablets was noted. CONCLUSION Ultrasound is an excellent modality for the diagnosis and characterisation of the neuroectodermal anomalies. Its multiplanar imaging property along with real time image visualisation make it an excellent tool for the diagnosis and characterisation of these anomalies

  13. Physical Modeling for Anomaly Diagnostics and Prognostics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop developed an innovative, model-driven anomaly diagnostic and fault characterization system for electromechanical actuator (EMA) systems to mitigate...

  14. Sparticle spectrum and constraints in anomaly mediated supersymmetry breaking models

    International Nuclear Information System (INIS)

    Huitu, K.; Laamanen, J.; Pandita, P.N.

    2002-01-01

    We study in detail the particle spectrum in anomaly mediated supersymmetry breaking models in which supersymmetry breaking terms are induced by the super-Weyl anomaly. We investigate the minimal anomaly mediated supersymmetry breaking models, gaugino assisted supersymmetry breaking models, as well as models with additional residual nondecoupling D-term contributions due to an extra U(1) gauge symmetry at a high energy scale. We derive sum rules for the sparticle masses in these models which can help in differentiating between them. We also obtain the sparticle spectrum numerically, and compare and contrast the results so obtained for the different types of anomaly mediated supersymmetry breaking models

  15. Magnetic anomalies in the Cosmonauts Sea, off East Antarctica

    Science.gov (United States)

    Nogi, Y.; Hanyu, T.; Fujii, M.

    2017-12-01

    Identification of magnetic anomaly lineations and fracture zone trends in the Southern Indian Ocean, are vital to understanding the breakup of Gondwana. However, the magnetic spreading anomalies and fracture zones are not clear in the Southern Indian Ocean. Magnetic anomaly lineations in the Cosmonauts Sea, off East Antarctica, are key to elucidation of separation between Sri Lanka/India and Antarctica. No obvious magnetic anomaly lineations are observed from a Japanese/German aerogeophysical survey in the Cosmonauts Sea, and this area is considered to be created by seafloor spreading during the Cretaceous Normal Superchron. Vector magnetic anomaly measurements have been conducted on board the Icebreaker Shirase mainly to understand the process of Gondwana fragmentation in the Indian Ocean. Magnetic boundary strikes are derived from vector magnetic anomalies obtained in the Cosmonauts Sea. NE-SW trending magnetic boundary strikes are mainly observed along the several NW-SE oriented observation lines with magnetic anomaly amplitudes of about 200 nT. These NE-SW trending magnetic boundary strikes possibly indicate M-series magnetic anomalies that can not be detected from the aerogeophysical survey with nearly N-S observation lines. We will discuss the magnetic spreading anomalies and breakup process between Sri Lanka/India and Antarctica in the Cosmonauts Sea.

  16. Prevalence of congenital anomalies in newborns with congenital heart disease diagnosis

    International Nuclear Information System (INIS)

    Egbe, Alexander; Lee, Simon; Ho, Deborah; Uppu, Santosh; Srivastava, Shubhika

    2014-01-01

    There is a known association between congenital heart disease (CHD) and other congenital anomalies (CA). These associations have been altered by changes in prenatal factors in recent time. We reviewed the largest database of inpatient hospitalization information and analyzed the current association between common CHD diagnoses and other congenital anomalies. Case-control study design. We reviewed the Nationwide Inpatient Sample (NIS) database from 1998 to 2008 and identified all live births with CHD diagnosis (case) and live births without CHD diagnosis (control). We compared prevalence of associated congenital anomalies between the case and control groups. Our cohort consisted of 97,154 and 12,078,482 subjects in the case and control groups, respectively. In the CHD population, prevalence of non-syndromic congenital anomaly (NSCA), genetic syndrome (GS), and overall extra-cardiac congenital anomaly (CA) were 11.4, 2.2, and 13.6%, respectively. In the control group, prevalence of NSCA, GS, and CA were 6.7, 0.3, and 7.0%, respectively. NSCA (odds ratio (OR): 1.88, confidence interval (CI): 1.73-1.94), GS (OR 2.52, CI 2.44-2.61), and overall CA (OR: 2.01, CI: 1.97-2.14) were strongly associated with CHD. Prevalence of GS and multiple organ-system CA decreased significantly over the study period. This is the largest and most comprehensive population-based study evaluating association between CHD and extra-cardiac malformation (ECM) in newborns. There was significant decrease in prevalence of GS and multiple CA over the study period

  17. An overview on preseismic anomalies in LF radio signals revealed in Italy by wavelet analysis

    Directory of Open Access Journals (Sweden)

    A. Ermini

    2008-06-01

    Full Text Available Since 1996, the electric field strength of the two broadcasting stations MCO (f=216 kHz, southeast France and CZE (f=270 kHz, Czech Republic has been sampled every ten minutes by a receiver (AS located in central Italy. Here, we review the results obtained by a detailed analysis applied to the data recorded from February 1996 up to December 2004. At first, the daytime and nighttime data were extracted and then, in the daytime data, the data collected in winter were separated from those collected in summer. On the second step the wavelet transform was applied. The results of this analysis are radio anomalies detected as earthquake precursors both for MCO and CZE data. In particular, regarding the MCO data, the main result was the appearance of a very clear anomaly during May-August 1998, at daytime and at nighttime. Such an anomaly can be considered as a precursor of a seismic sequence started on August 15, 1998 with 17 earthquakes (M=2.2-4.6 on the Reatini mountains, a seismogenic zone located 30 km far from the AS receiver along the path MCO-AS. As concerns with the CZE data, the first result was obtained from the summer daytime data and it was the appearance of a very clear anomaly during August-September 1997, that can be considered a precursor of the two earthquakes with magnitude M=5.6 and M=5.9 that occurred on September 26 in the Umbria-Marche region (Central Italy. The second result was the appearance of an anomaly during February-March 1998, at daytime and at nighttime, that can be related to the preparatory phase of the strong (M=5.1-6.0 Slovenia seismic sequence that occurred in a zone lying in the middle of the CZE-AS path.

  18. The Lagrangian structure of ozone mini-holes and potential vorticity anomalies in the Northern Hemisphere

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    P. M. James

    Full Text Available An ozone mini-hole is a synoptic-scale area of strongly reduced column total ozone, which undergoes a growth-decay cycle in association with baroclinic weather systems. The tracks of mini-hole events recorded during the TOMS observation period over the Northern Hemisphere provide a database for building anomaly fields of various meteorological parameters, following each mini-hole center in a Lagrangian sense. The resulting fields provide, for the first time, a complete mean Lagrangian picture of the three-dimensional structure of typical ozone mini-holes in the Northern Hemisphere. Mini-holes are shown to be associated with anomalous warm anticyclonic flow in the upper troposphere and cold cyclonic anomalies in the middle stratosphere. Ascending air columns occur upstream and descent downstream of the mini-hole centers. Band-pass filtering is used to reveal the transient synoptic nature of mini-holes embedded within larger scale circulation anomalies. Significant correlations between ozone and Ertel’s potential vorticity on isentropes (IPV both near the tropopause and in the middle stratosphere are shown and then utilized by reconstructing the Lagrangian analysis to follow local IPV anomalies instead of ozone minima. By using IPV as a proxy for ozone, the geopotential anomaly dipolar structure in the vertical characteristic of mini-holes is shown to result from a superposition of two largely independent dynamical components, stratospheric and tropospheric, typically operating on different time scales. Hence, ozone mini-holes may be viewed primarily as phenomena of coincidence.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; synoptic-scale meteorology

  19. The Lagrangian structure of ozone mini-holes and potential vorticity anomalies in the Northern Hemisphere

    Directory of Open Access Journals (Sweden)

    P. M. James

    2002-06-01

    Full Text Available An ozone mini-hole is a synoptic-scale area of strongly reduced column total ozone, which undergoes a growth-decay cycle in association with baroclinic weather systems. The tracks of mini-hole events recorded during the TOMS observation period over the Northern Hemisphere provide a database for building anomaly fields of various meteorological parameters, following each mini-hole center in a Lagrangian sense. The resulting fields provide, for the first time, a complete mean Lagrangian picture of the three-dimensional structure of typical ozone mini-holes in the Northern Hemisphere. Mini-holes are shown to be associated with anomalous warm anticyclonic flow in the upper troposphere and cold cyclonic anomalies in the middle stratosphere. Ascending air columns occur upstream and descent downstream of the mini-hole centers. Band-pass filtering is used to reveal the transient synoptic nature of mini-holes embedded within larger scale circulation anomalies. Significant correlations between ozone and Ertel’s potential vorticity on isentropes (IPV both near the tropopause and in the middle stratosphere are shown and then utilized by reconstructing the Lagrangian analysis to follow local IPV anomalies instead of ozone minima. By using IPV as a proxy for ozone, the geopotential anomaly dipolar structure in the vertical characteristic of mini-holes is shown to result from a superposition of two largely independent dynamical components, stratospheric and tropospheric, typically operating on different time scales. Hence, ozone mini-holes may be viewed primarily as phenomena of coincidence.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; synoptic-scale meteorology

  20. Incidence of Congenital Heart Diseases Anomalies in Newborns with Oral Clefts, Zahedan, Iran

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    Noor Mohammad Noori

    2016-09-01

    Full Text Available Background Oral cleft is the most common orofacial congenital anomaly among live births. This anomaly at birth is one of the main causes of children disability and mortality.  Congenital heart disease (CHD is one of the most common anomalies in oral clefts.  This study aimed to assess the incidence of congenital heart diseases anomalies in newborns with oral clefts. Materials and Methods This study performed on 48,692 live born to estimate incidence of oral clefts from 1 st December 2013 to 31 th November 2015 from three general hospitals in Zahedan, The capital city of the Sistan & Baluchestan  province, Iran. All oral cleft patients were under echocardiography to diagnosis the incidence of CHD as associated anomaly. The collected data were processed using SPSS-16. Results The results of the analysis showed that the incidence of cleft lip was higher in boys than girls, while the cleft palate was higher in girls. Lip/palate cleft was higher for boys.  Oral clefts patients accounted of 102 (0.2% with incidence rate of 2.095 per 1000 lives. Of 102 patients 19 (18.62%, 39(35.24% and 44(43.14% were oral lip, oral palate and both respectively. The incidence of CHD in patients with oral clefts was 26.5%, while the incidences for cleft lip, cleft palate and both were 15.79%, 20.51%, and 36.36% respectively. Conclusion From the study concluded that the rate of CHD among children with oral clefts was high compared with the healthy children.  Strongly is suggested the echocardiography for these patients to have early diagnostic of CHD to manage any life-threatening.