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Sample records for boundary transform fault

  1. Undecimated Lifting Wavelet Packet Transform with Boundary Treatment for Machinery Incipient Fault Diagnosis

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    Lixiang Duan

    2016-01-01

    Full Text Available Effective signal processing in fault detection and diagnosis (FDD is an important measure to prevent failure and accidents of machinery. To address the end distortion and frequency aliasing issues in conventional lifting wavelet transform, a Volterra series assisted undecimated lifting wavelet packet transform (ULWPT is investigated for machinery incipient fault diagnosis. Undecimated lifting wavelet packet transform is firstly formulated to eliminate the frequency aliasing issue in traditional lifting wavelet packet transform. Next, Volterra series, as a boundary treatment method, is used to preprocess the signal to suppress the end distortion in undecimated lifting wavelet packet transform. Finally, the decomposed wavelet coefficients are trimmed to the original length as the signal of interest for machinery incipient fault detection. Experimental study on a reciprocating compressor is performed to demonstrate the effectiveness of the presented method. The results show that the presented method outperforms the conventional approach by dramatically enhancing the weak defect feature extraction for reciprocating compressor valve fault diagnosis.

  2. Seismicity of the diffusive Iberian/African plate boundary at the eastern terminus of the Azores-Gibraltar Transform fault

    Science.gov (United States)

    Lange, D.; Grevemeyer, I.; Matias, L. M.

    2014-12-01

    The plate boundary at the eastern terminus of the Azores-Gibraltar transform fault between Africa and Iberia is poorly defined. The deformation in the area is forced by the slow NW-SE convergence of 4 mm/yr between the oceanic domains of Iberia/Eurasia and Africa and is accommodated over a 200 km broad tectonically-active deformation zone. The region, however, is also characterized by large earthquakes, such as the 1969 Mw=7.9 Horseshoe event and the November 1, 1755 Great Lisbon earthquake with an estimated magnitude of Mw~8.5. The exact location of the source of the 1755 Lisbon earthquake is still unknown. Recent work may suggest that the event occurred in the vicinity of the Horseshoe fault, an oblique thrust fault. However, estimates of tsunami arrival times suggested a source near the Gorringe Bank, a ~180 km-long and ~70 km-wide ridge that has a relieve of ~5000 m. Deep Sea Drilling (DSDP) and rock samples indicated that the bank is mainly composed of serpentinized peridotites with gabbroic intrusions, perhaps being created by overthrusting of the Horseshoe Abyssal Plain onto the Tagus Abyssal Plain in NW direction. Further, the Horseshoe Abyssal Plain is marked by the presence of compressive structures with a roughly NE-SW orientation and E-W trending, segmented, crustal-scale, strike slip faults that extend from the Gorringe Bank to the Gibraltar Arc in the eastern Gulf of Cadiz, which were called "South West Iberian Margin" or SWIM faults. The fault system may mark a developing Eurasia-Africa plate boundary. Two local seismic networks were operated in the area. First, a network of 14 ocean-bottom seismometers (OBS) was operated between April and October 2012 in the vicinity of the Horseshoe fault between 10°W to 11°W, and 35°50'N to 36°10'N. From October 2013 to March 2014 a second network of 15 OBS monitored seismicity at the Gorringe Bank. Both networks benefitted from seismic stations operated in Portugal. The first network provided in the order of

  3. Cell boundary fault detection system

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    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2009-05-05

    A method determines a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

  4. Paleoseismic observations of an onshore transform boundary: the Magallanes-Fagnano fault, Tierra del Fuego Argentina

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    C.H. Costa

    2006-12-01

    Full Text Available We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places east of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault `was excavated at the Río San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre- 1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocene(? deposits, but the vertical component of the 1949 events was always less than ~1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along the part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone.

  5. Paleoseismic observations of an onshore transform boundary: The Magallanes-Fagnano fault, Tierra del Fuego, Argentina

    Science.gov (United States)

    Costa, C.H.; Smalley, R.; Schwartz, D.P.; Stenner, Heidi D.; Ellis, M.; Ahumada, E.A.; Velasco, M.S.

    2006-01-01

    We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places cast of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault was excavated at the Ri??o San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre-1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocence(?) deposits, but the vertical component of the 1949 events was always less than ???1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along die part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone. ?? 2006 Revista de la Asociacio??n Geolo??gica Argentina.

  6. Paleoseismic observations of an onshore transform boundary: the Magallanes-Fagnano fault, Tierra del Fuego Argentina

    Directory of Open Access Journals (Sweden)

    C.H. Costa

    2006-12-01

    Full Text Available We present preliminary information on the geomorphologic features and paleoseismic record associated with the ruptures of two Ms 7.8 earthquakes that struck Tierra del Fuego and the southernmost continental margin of South America on December 17, 1949. The fault scarp was surveyed in several places east of Lago Fagnano and a trench across a secondary fault trace of the Magallanes-Fagnano fault `was excavated at the Río San Pablo. The observed deformation in a 9 kyr-old peat bog sequence suggests evidence for two, and possibly three pre- 1949 paleoearthquakes is preserved in the stratigraphy. The scarp reaches heights up to 11 m in late Pleistocene-Holocene(? deposits, but the vertical component of the 1949 events was always less than ~1 m. This observation also argues for the occurrence of previous events during the Quaternary. Along the part of the fault we investigated east of Lago Fagnano, the horizontal component of the 1949 rupture does not exceed 4 m and is likely lower than 0.4 m, which is consistent with the kinematics of a local releasing bend, or at the end of a strike-slip rupture zone.Se presenta información sobre las evidencias geomorfológicas y paleosísmicas observadas al este del lago Fagnano, relacionadas con dos terremotos de Ms 7,8, que ocurrieron en Tierra del Fuego el 17 de diciembre de 1949. Se efectuaron relevamientos en las escarpas observadas en los alrededores de Tolhuin y Estancia La Correntina-Río San Pablo. En este último sitio, se excavó una trinchera en un trazo secundario de la falla Magallanes-Fagnano con el propósito de analizar el registro paleosísmico de esta estructura. Con el apoyo de dataciones radiocarbónicas se reconoció la estratigrafía correspondiente a los últimos 9 ka, interpretándose por lo menos dos eventos sísmicos con rupturas superficiales previos al sismo de 1949 en este trazo de la falla. Se reconocieron escarpas asociadas de hasta 11 m de altura en depósitos atribuibles al

  7. Dead sea transform fault system reviews

    CERN Document Server

    Garfunkel, Zvi; Kagan, Elisa

    2014-01-01

    The Dead Sea transform is an active plate boundary connecting the Red Sea seafloor spreading system to the Arabian-Eurasian continental collision zone. Its geology and geophysics provide a natural laboratory for investigation of the surficial, crustal and mantle processes occurring along transtensional and transpressional transform fault domains on a lithospheric scale and related to continental breakup. There have been many detailed and disciplinary studies of the Dead Sea transform fault zone during the last?20 years and this book brings them together.This book is an updated comprehensive coverage of the knowledge, based on recent studies of the tectonics, structure, geophysics, volcanism, active tectonics, sedimentology and paleo and modern climate of the Dead Sea transform fault zone. It puts together all this new information and knowledge in a coherent fashion.

  8. Continental Transform Boundaries: Tectonic Evolution and Geohazards

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    Michael Steckler

    2012-04-01

    Full Text Available Continental transform boundaries cross heavily populated regions, and they are associated with destructive earthquakes,for example, the North Anatolian Fault (NAFacross Turkey, the Enriquillo-Plantain Garden fault in Haiti,the San Andreas Fault in California, and the El Pilar fault in Venezuela. Transform basins are important because they are typically associated with 3-D fault geometries controlling segmentation—thus, the size and timing of damaging earthquakes—and because sediments record both deformation and earthquakes. Even though transform basins have been extensively studied, their evolution remains controversial because we don’t understand the specifics about coupling of vertical and horizontal motions and about the basins’long-term kinematics. Seismic and tsunami hazard assessments require knowing architecture and kinematics of faultsas well as how the faults are segmented.

  9. Initiation of Ridges and Transform Faults

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    Nyst, M.; Thompson, G. A.; Parsons, T.

    2004-12-01

    No clear consensus has emerged to explain initiation of the strikingly regular pattern of ocean ridges and transform faults. The question is important on the continents also, because a less regular pattern of step-overs on faults such as the San Andreas influences the sources of earthquakes. We explore the question by finite element modeling and a study of observational data on ridges and transforms. We focus on the simplest case, where ridges and transforms seem to self-organize at new plate boundaries as soon as new oceanic (magmatic) crust forms. The South Atlantic supplies a clear example. Continental South America and Africa separated along an irregular break, whose general shape is still preserved in the Mid-Atlantic Ridge. In detail, however, the sea floor magnetic anomalies and satellite gravity show that traces of the ridges and transforms extend to the base of the continental slope, i.e. they formed quickly in the new oceanic crust. The Gulf of California provides another clear example and is notable because of its northward transition into the continental San Andreas fault system. In continental crust, dike segments connected by transform faults provide the clearest analogues of oceanic ridges and transforms. Remarkably, the ridge-transform pattern has been simulated by pulling the crust on molten wax [Oldenburg and Brune, JGR, 80, 1975] and also observed in the crust of a molten lava lake [Duffield, JGR, 77, 1972]. In neither of these models, however, do the spatial and temporal scales permit investigation of the dikes whose repeated emplacement and inflation builds layer 3 of the ocean crust. It is well established that, under a buoyant head of magma, dikes tend to fracture and intrude the crust in planes perpendicular to the least horizontal stress, and they relieve the stress difference as they inflate [e.g. Parsons and Thompson, Science, 253, 1991]. Dikes are commonly used as stress-direction indicators analogous to artificial hydraulic fractures

  10. 珠江口盆地惠州凹陷北部边界断裂复合联接和转换%Complex Linkage and Transformation of Boundary Faults of Northern Huizhou Sag in Pearl River Mouth Basin

    Institute of Scientific and Technical Information of China (English)

    田巍; 何敏; 杨亚娟; 刘海伦; 袁勋; 吴森; 朱定伟; 梅廉夫

    2015-01-01

    study.The results show that the northern boun-ding faults of northern Huizhou sag have an offset geometry in Early Eocene,characterized by along-strike and transverse two-way linkage.The along-strike linkage is a composite connection-transformation of “soft and hard”linkage,forming a relay ramp and transverse folds which restrict the structural evolution within Huizhou sag and the migration of its depocenters and sequences.The transverse linkage means the multiple-stage linkage of the transfer faults in relay ramp,including three stages, namely,isolated normal faulting,synthetic overlapping and hard linkage,which control the migration and distribution of depo-sitional system within the relay ramp.This paper presents a unique case of spatial evolution,complex linkage and transforma-tion model of boundary faults in a rift basin,which can facilitate further studies on the response relationship among the bounda-ry fault,sedimentary sequence,sag evolution and regional dynamics mechanism.

  11. Fault interaction and stresses along broad oceanic transform zone: Tjörnes Fracture Zone, north Iceland

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    Homberg, C.; Bergerat, F.; Angelier, J.; Garcia, S.

    2010-02-01

    Transform motion along oceanic transforms generally occurs along narrow faults zones. Another class of oceanic transforms exists where the plate boundary is quite large (˜100 km) and includes several subparallel faults. Using a 2-D numerical modeling, we simulate the slip distribution and the crustal stress field geometry within such broad oceanic transforms (BOTs). We examine the possible configurations and evolution of such BOTs, where the plate boundary includes one, two, or three faults. Our experiments show that at any time during the development of the plate boundary, the plate motion is not distributed along each of the plate boundary faults but mainly occurs along a single master fault. The finite width of a BOT results from slip transfer through time with locking of early faults, not from a permanent distribution of deformation over a wide area. Because of fault interaction, the stress field geometry within the BOTs is more complex than that along classical oceanic transforms and includes stress deflections close to but also away from the major faults. Application of this modeling to the 100 km wide Tjörnes Fracture Zone (TFZ) in North Iceland, a major BOT of the Mid-Atlantic Ridge that includes three main faults, suggests that the Dalvik Fault and the Husavik-Flatey Fault developed first, the Grismsey Fault being the latest active structure. Since initiation of the TFZ, the Husavik-Flatey Fault accommodated most of the plate motion and probably persists until now as the main plate structure.

  12. Rheology and friction along the Vema transform fault (Central Atlantic) inferred by thermal modeling

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    Cuffaro, Marco; Ligi, Marco

    2016-04-01

    We investigate with 3-D finite element simulations the temperature distribution beneath the Vema transform that offsets the Mid-Atlantic Ridge by ~300 km in the Central Atlantic. The developed thermal model includes the effects of mantle flow beneath a ridge-transform-ridge geometry and the lateral heat conduction across the transform fault, and of the shear heating generated along the fault. Numerical solutions are presented for a 3-D domain, discretized with a non-uniform tetrahedral mesh, where relative plate kinematics is used as boundary condition, providing passive mantle upwelling. Mantle is modelled as a temperature-dependent viscous fluid, and its dynamics can be described by Stokes and advection-conduction heat equations. The results show that shear heating raises significantly the temperature along the transform fault. In order to test model results, we calculated the thermal structure simulating the mantle dynamics beneath an accretionary plate boundary geometry that duplicates the Vema transform fault, assuming the present-day spreading rate and direction of the Mid Atlantic Ridge at 11 °N. Thus, the modelled heat flow at the surface has been compared with 23 heat flow measurements carried out along the Vema Transform valley. Laboratory studies on the frictional stability of olivine aggregates show that the depth extent of oceanic faulting is thermally controlled and limited by the 600 °C isotherm. The depth of isotherms of the thermal model were compared to the depths of earthquakes along transform faults. Slip on oceanic transform faults is primarily aseismic, only 15% of the tectonic offset is accommodated by earthquakes. Despite extensive fault areas, few large earthquakes occur on the fault and few aftershocks follow large events. Rheology constrained by the thermal model combined with geology and seismicity of the Vema Transform fault allows to better understand friction and the spatial distribution of strength along the fault and provides

  13. Transformer fault diagnosis using continuous sparse autoencoder.

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    Wang, Lukun; Zhao, Xiaoying; Pei, Jiangnan; Tang, Gongyou

    2016-01-01

    This paper proposes a novel continuous sparse autoencoder (CSAE) which can be used in unsupervised feature learning. The CSAE adds Gaussian stochastic unit into activation function to extract features of nonlinear data. In this paper, CSAE is applied to solve the problem of transformer fault recognition. Firstly, based on dissolved gas analysis method, IEC three ratios are calculated by the concentrations of dissolved gases. Then IEC three ratios data is normalized to reduce data singularity and improve training speed. Secondly, deep belief network is established by two layers of CSAE and one layer of back propagation (BP) network. Thirdly, CSAE is adopted to unsupervised training and getting features. Then BP network is used for supervised training and getting transformer fault. Finally, the experimental data from IEC TC 10 dataset aims to illustrate the effectiveness of the presented approach. Comparative experiments clearly show that CSAE can extract features from the original data, and achieve a superior correct differentiation rate on transformer fault diagnosis.

  14. Magnetic character of a large continental transform: an aeromagnetic survey of the Dead Sea Fault

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    ten Brink, Uri S.; Rybakov, Michael; Al-Zoubi, Abdallah S.; Rotstein, Yair

    2007-01-01

    New high-resolution airborne magnetic (HRAM) data along a 120-km-long section of the Dead Sea Transform in southern Jordan and Israel shed light on the shallow structure of the fault zone and on the kinematics of the plate boundary. Despite infrequent seismic activity and only intermittent surface exposure, the fault is delineated clearly on a map of the first vertical derivative of the magnetic intensity, indicating that the source of the magnetic anomaly is shallow. The fault is manifested by a 10–20 nT negative anomaly in areas where the fault cuts through magnetic basement and by a

  15. The relationship between oceanic transform fault segmentation, seismicity, and thermal structure

    Science.gov (United States)

    Wolfson-Schwehr, Monica

    analysis is used to model 3-D RTF fault geometry assuming a viscoplastic rheology in order to determine how segmentation affects the underlying thermal structure of the fault. In the models, fault segment length, length and location along fault of the intra-transform spreading center, and slip rate are varied. A new scaling relation is developed for the critical fault offset length (OC) that significantly reduces the thermal area of adjacent fault segments, such that adjacent segments are fully decoupled at ~4 OC . On moderate to fast slipping RTFs, offsets ≥ 5 km are sufficient to significantly reduce the thermal influence between two adjacent transform fault segments. The relationship between fault structure and seismic behavior was directly addressed on the Discovery transform fault, located at 4°S on the East Pacific Rise. One year of microseismicity recorded on an OBS array, and 24 years of Mw ≥ 5.4 earthquakes obtained from the Global Centroid Moment Tensor catalog, were correlated with surface fault structure delineated from high-resolution multibeam bathymetry. Each of the 15 Mw ≥ 5.4 earthquakes was relocated into one of five distinct repeating rupture patches, while microseismicity was found to be reduced within these patches. While the endpoints of these patches appeared to correlate with structural features on the western segment of Discovery, small step-overs in the primary fault trace were not observed at patch boundaries. This indicates that physical segmentation of the fault is not the primary control on the size and location of large earthquakes on Discovery, and that along-strike heterogeneity in fault zone properties must play an important role.

  16. A Fault-Cored Anticline Boundary Element Model Incorporating the Combined Fault Slip and Buckling Mechanisms

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    Wen-Jeng Huang

    2016-02-01

    Full Text Available We develop a folding boundary element model in a medium containing a fault and elastic layers to show that anticlines growing over slipping reverse faults can be significantly amplified by mechanical layering buckling under horizontal shortening. Previous studies suggested that folds over blind reverse faults grow primarily during deformation increments associated with slips on the fault during and immediately after earthquakes. Under this assumption, the potential for earthquakes on blind faults can be determined directly from fold geometry because the amount of slip on the fault can be estimated directly from the fold geometry using the solution for a dislocation in an elastic half-space. Studies that assume folds grown solely by slip on a fault may therefore significantly overestimate fault slip. Our boundary element technique demonstrates that the fold amplitude produced in a medium containing a fault and elastic layers with free slip and subjected to layer-parallel shortening can grow to more than twice the fold amplitude produced in homogeneous media without mechanical layering under the same amount of shortening. In addition, the fold wavelengths produced by the combined fault slip and buckling mechanisms may be narrower than folds produced by fault slip in an elastic half space by a factor of two. We also show that subsurface fold geometry of the Kettleman Hills Anticline in Central California inferred from seismic reflection image is consistent with a model that incorporates layer buckling over a dipping, blind reverse fault and the coseismic uplift pattern produced during a 1985 earthquake centered over the anticline forelimb is predicted by the model.

  17. A Dynamic Integrated Fault Diagnosis Method for Power Transformers

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    Wensheng Gao

    2015-01-01

    Full Text Available In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified.

  18. Towards understanding earthquake nucleation on a severely misoriented plate boundary fault, Alpine Fault, New Zealand

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    Boulton, C. J.; Faulkner, D. R.; Allen, M. J.; Coussens, J.; Menzies, C. D.; Mariani, E.

    2016-12-01

    New Zealand's Alpine Fault has accommodated relative motion between the Australian and Pacific plates for over 23 million years: first as strike-slip fault and then as an oblique transpressional fault. Despite being driven by principal stresses whose orientations have undoubtedly changed with time, the Alpine Fault continues to accommodate 70% of the relative plate boundary motion. Fault outcrop data and seismic reflection data indicate that the central Alpine Fault is consistently oriented 055/45°SE at depths up to 15 km (i.e., throughout the seismogenic zone); focal mechanisms indicate that the stress tensor is oriented σ1=σHmax=0/117°, σ2=σv, and σ3=0/207° (Boese et al. 2013, doi: 10.1016/j.epsl.2013.06.030). At depth, the central Alpine Fault lies at an angle of 51° to σ1. The Mohr-Coulomb failure criterion stipulates that, for incohesive rocks, reactivation of a fault requires sufficient driving stress to overcome frictional resistance to slip. Using a coefficient of friction (μ) of 0.6, as measured for representative Alpine Fault rocks under in situ conditions (Neimeijer et al. 2016, doi:10.1002/2015JB012593), and an estimated stress shape ratio (Φ=(σ2 - σ3)/(σ1 - σ3)=0.5), a 3-D reactivation analysis was performed (Leclère and Fabbri 2013, doi:10.1016/j.jsg.2012.11.004). Results show that the Alpine Fault is severely misoriented for failure, requiring pore fluid pressures greater than the least principal stress to initiate frictional sliding. However, microstructural evidence, including pseudotachylytes and fault gouge injection structures, suggests that earthquakes nucleate and propagate along this major plate boundary fault. By assuming an increase in differential stress of 15 MPa/km, our analysis shows that reactivation may occur with suprahydrostatic pore fluid pressures given a ≥10° counterclockwise rotation of σHmax. Using measured hydraulic data, we estimate the potential for pore fluid overpressure development within the Alpine

  19. A New Method of Improving Transformer Restricted Earth Fault Protection

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    KRSTIVOJEVIC, J. P.

    2014-08-01

    Full Text Available A new method of avoiding malfunctioning of the transformer restricted earth fault (REF protection is presented. Application of the proposed method would eliminate unnecessary operation of REF protection in the cases of faults outside protected zone of a transformer or a magnetizing inrush accompanied by current transformer (CT saturation. On the basis of laboratory measurements and simulations the paper presents a detailed performance assessment of the proposed method which is based on digital phase comparator. The obtained results show that the new method was stable and precise for all tested faults and that its application would allow making a clear and precise difference between an internal fault and: (i external fault or (ii magnetizing inrush. The proposed method would improve performance of REF protection and reduce probability of maloperation due to CT saturation. The new method is robust and characterized by high speed of operation and high reliability and security.

  20. High-Resolution LiDAR Topography of the Plate-Boundary Faults in Northern California

    Science.gov (United States)

    Prentice, C. S.; Phillips, D. A.; Furlong, K. P.; Brown, A.; Crosby, C. J.; Bevis, M.; Shrestha, R.; Sartori, M.; Brocher, T. M.; Brown, J.

    2007-12-01

    GeoEarthScope acquired more than 1500 square km of airborne LiDAR data in northern California, providing high-resolution topographic data of most of the major strike-slip faults in the region. The coverage includes the San Andreas Fault from its northern end near Shelter Cove to near Parkfield, as well as the Rodgers Creek, Maacama, Calaveras, Green Valley, Paicines, and San Gregorio Faults. The Hayward fault was added with funding provided by the US Geological Survey, the City of Berkeley, and the San Francisco Public Utilities Commission. Data coverage is typically one kilometer in width, centered on the fault. In areas of particular fault complexity the swath width was increased to two kilometers, and in selected areas swath width is as wide as five kilometers. A five-km-wide swath was flown perpendicular to the plate boundary immediately south of Cape Mendocino to capture previously unidentified faults and to understand off-fault deformation associated with the transition zone between the transform margin and the Cascadia subduction zone. The data were collected in conjunction with an intensive GPS campaign designed to improve absolute data accuracy and provide quality control. Data processing to classify the LiDAR point data by return type allows users to filter out vegetation and produce high-resolution DEMs of the ground surface beneath forested regions, revealing geomorphic features along and adjacent to the faults. These data will allow more accurate mapping of fault traces in regions where the vegetation canopy has hampered this effort in the past. In addition, the data provide the opportunity to locate potential sites for detailed paleoseismic studies aimed at providing slip rates and event chronologies. The GeoEarthScope LiDAR data will be made available via an interactive data distribution and processing workflow currently under development.

  1. Application of extension method to fault diagnosis of transformer

    Institute of Scientific and Technical Information of China (English)

    DENG Hong-gui; CAO Jian; LUO An; XIA Xiang-yang

    2007-01-01

    A novel extension diagnosis method was proposed for enhancing the diagnosis ability of the conventional dissolved gas analysis. Based on the extension theory a matter-element model was established for qualitatively and quantitatively describing the fault diagnosis problem of power transformers. The degree of relation based on the dependent functions WaS employed to determine then ature and the grade of the faults in a transformer system.And the proposed method was verified with the experimental data.The results show that accuracy rate of the diagnosis method exceeds 90% and two kinds of faults call be detected at the same time.

  2. The fluid budget of a continental plate boundary fault: Quantification from the Alpine Fault, New Zealand

    Science.gov (United States)

    Menzies, Catriona D.; Teagle, Damon A. H.; Niedermann, Samuel; Cox, Simon C.; Craw, Dave; Zimmer, Martin; Cooper, Matthew J.; Erzinger, Jörg

    2016-07-01

    Fluids play a key role in modifying the chemical and physical properties of fault zones, which may prime them for repeated rupture by the generation of high pore fluid pressures and precipitation of commonly weak, secondary minerals. Fluid flow paths, sources and fluxes, and the permeability evolution of fault zones throughout their seismic cycles remain poorly constrained, despite their importance to understanding fault zone behaviour. Here we use geochemical tracers of fluid-rock exchange to determine budgets for meteoric, metamorphic and mantle fluids on a major compressional tectonic plate boundary. The Alpine Fault marks the transpressional Pacific-Australian plate boundary through South Island, New Zealand and appears to fail in regular (329 ± 68 yrs) large earthquakes (Mw ∼ 8) with the most recent event in 1717 AD. Significant convergent motion has formed the Southern Alps and elevated geothermal gradients in the hangingwall, which drive crustal fluid flow. Along the Alpine Fault the Alpine Schist of the Pacific Plate is thrust over radiogenic metasedimentary rocks on the Australian plate. The absence of highly radiogenic (87Sr/86Sr > 0.7200) strontium isotope ratios of hangingwall hot springs and hydrothermal minerals formed at a range of depths in the Alpine Fault damage zone indicates that the fluid flow is restricted to the hangingwall by a cross-fault fluid flow barrier throughout the seismogenic crust. Helium isotope ratios measured in hot springs near to the Alpine Fault (0.15-0.81 RA) indicate the fault is a crustal-scale feature that acts as a conduit for fluids from the mantle. Rock-exchanged oxygen, but meteoric water-like hydrogen isotope signatures of hydrothermal veins indicate that partially rock-exchanged meteoric fluids dominate down to the top of the brittle to ductile transition zone at ∼6 km. Geochemical tracer transport modelling suggests only ∼0.02 to 0.05% of total rainfall west of the Main Divide penetrates to depth, yet this

  3. Research on Transformer Fault Based on Probabilistic Neural Network

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    Li Yingshun

    2015-01-01

    Full Text Available With the development of computer science and technology, and increasingly intelligent industrial production, the application of big data in industry also advances rapidly, and the development of artificial intelligence in the aspect of fault diagnosis is particularly prominent. On the basis of MATLAB platform, this paper constructs a fault diagnosis expert system of artificial intelligence machine based on the probabilistic neural network, and it also carries out a simulation of production process by the use of bionic algorithm. This paper makes a diagnosis of transformer fault by the use of an expert system developed by this paper, and verifies that the probabilistic neural network has a good convergence, fault-tolerant ability and big data handling capability in the fault diagnosis. It is suitable for industrial production, which can provide a reliable mathematical model for the construction of fault diagnosis expert system in the industrial production.

  4. Seismic zonation of the Dead Sea Transform Fault area

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    E. E. Papadimitriou

    2000-06-01

    Full Text Available The Dead Sea Transform Fault constitutes the northwestern boundary of the Arabian plate, accommodating the plate’s lateral movement relative to the African plate. A complete and homogeneous catalogue of historical earthquakes has been compiled and used in the subdivision of the fault area into the following segments: 1 Araba segment, which extends along Wadi Araba and the southernmost part of the Dead Sea (29.5°-31.3°N and trends SSW-NNE with scarce historical and instrumental seismicity; 2 Jordan-valley segment, which extends along the central and northern parts of the Dead Sea and the Jordan valley to the Huleh depression (31.3°-33.1° N and trends S-N with moderate historical seismicity; 3 Beqa’a segment, which extends along the western margin of the Beqa’a valley in Lebanon (33.1°-34.5°N and trends SSW-NNE with strong historical seismicity; 4 El-Ghab segment, which extends along the eastern flank of the coastal mountain range of Syria (34.5°-35.8°N and trends S-N with moderate historical seismicity; 5 Karasu segment, which extends along the Karasu valley in SE Turkey (35.8°-37.3°N and trends SSW-NNE, exhibiting the strongest historical seismicity of the area. Probabilities for the generation of strong (M > 6.0 earthquakes in these segments during the next decade are given, by the application of the regional time and magnitude predictable model.

  5. Earthquake cycle on a transform fault in the Gulf of California, Mexico.

    Science.gov (United States)

    Malservisi, Rocco; Hackl, Matthias; Plattner, Christina; Suarez Vidal, Francisco; Gonzales Garcia, Javier; Amelung, Falk

    2010-05-01

    South of the San Andreas Fault system, ~90% of the North America/Pacific plate motion is accommodated along the Gulf of California. Here the plate boundary deformation is partitioned in deep basins formation, often resulting in production of new oceanic crust, connected by long transform faults. In the central part of the Gulf, one of these transform faults, the Ballenas fault, is localized in the Canal de Ballenas, a ~30 km wide channel between Isla Angel de la Garda and mainland Baja California in an area where full oceanic crust is still not generated. The presence of land on both the sides of this "quasi marine" transform fault give the unique opportunity to perform geodetic studies across its trace. On August 3rd 2009, a series of seismic strike slip events (including a M6.9) happened along this segment of plate boundary allowing a combined study of co- and inter-seismic deformation. Here we present the results from 5 years of EGPS along a transect perpendicular to the plate motion direction at approximately 29 degrees North. These surveys include at least 3 occupations before the seismic event and at least 2 occupations after the earthquake. The analysis of the inter-seismic data shows that ~46 mm/yr of relative motion is accommodated within the Canal de Ballenas. Co-seismic data show displacements up to 25 cm on the two sites closest to the event and a pattern compatible with the finite fault model computed by USGS (although the USGS location of the hypocenter is probably 100 km too much to the East). The geodetically estimated fault location is also compatible with multibeam bathymetry. The data collected after the earthquake show also the possibility to identify postseismic displacement from the campaign data. They also show the possibility that the postseismic behavior of the "marine" side is different from the one of the on land side.

  6. Transform faults and large horizontal displacements of the ocean floor

    Directory of Open Access Journals (Sweden)

    G. RANALLI

    1968-06-01

    Full Text Available The evidence concerning the existence of transform
    faults and the occurrence of sea-floor spreading is reviewed and discussed.
    Available fault-plane solutions indicate that the direction of motion along
    some oceanic fracture zones is opposite to that which would be expected
    in case of transcurrent faults. The support for the sea-floor spreading hypothesis
    comes mainly from magnetic investigations. The problem, however,
    presents formidable dynamic and rheological aspects, and is far from being
    completely solved.

  7. Stacking fault tetrahedra formation in the neighbourhood of grain boundaries

    CERN Document Server

    Samaras, M; Van Swygenhoven, H; Victoria, M

    2003-01-01

    Large scale molecular dynamics computer simulations are performed to study the role of the grain boundary (GB) during the cascade evolution in irradiated nanocrystalline Ni. At all primary knock-on atom (PKA) energies in cascades near GBs, the damage produced after cooling down is vacancy dominated. Truncated stacking fault tetrahedra (TSFTs) are easily formed at 10 keV and higher PKA energies. At the higher energies a complex partial dislocation network forms, consisting of TSFTs. The GB acts as an interstitial sink without undergoing major structural changes.

  8. Battery Fault Detection with Saturating Transformers

    Science.gov (United States)

    Davies, Francis J. (Inventor); Graika, Jason R. (Inventor)

    2013-01-01

    A battery monitoring system utilizes a plurality of transformers interconnected with a battery having a plurality of battery cells. Windings of the transformers are driven with an excitation waveform whereupon signals are responsively detected, which indicate a health of the battery. In one embodiment, excitation windings and sense windings are separately provided for the plurality of transformers such that the excitation waveform is applied to the excitation windings and the signals are detected on the sense windings. In one embodiment, the number of sense windings and/or excitation windings is varied to permit location of underperforming battery cells utilizing a peak voltage detector.

  9. Distinctive diamagnetic fabrics in dolostones evolved at fault cores, the Dead Sea Transform

    Science.gov (United States)

    Braun, D.; Weinberger, R.; Eyal, Y.; Feinstein, S.; Harlavan, Y.; Levi, T.

    2015-08-01

    We resolve the anisotropy of magnetic susceptibility (AMS) axes along fault planes, cores and damage zones in rocks that crop out next to the Dead Sea Transform (DST) plate boundary. We measured 261 samples of mainly diamagnetic dolostones that were collected from 15 stations. To test the possible effect of the iron content on the AMS we analyzed the Fe concentrations of the samples in different rock phases. Dolostones with mean magnetic susceptibility value lower than -4 × 10-6 SI and iron content less than ∼1000 ppm are suitable for diamagnetic AMS-based strain analysis. The dolostones along fault planes display AMS fabrics that significantly deviate from the primary "sedimentary fabric". The characteristics of these fabrics include well-grouped, sub-horizontal, minimum principal AMS axes (k3) and sub-vertical magnetic foliations commonly defined by maximum and intermediate principal AMS axes (k1 and k2 axes, respectively). These fabrics are distinctive along fault planes located tens of kilometers apart, with strikes ranging between NNW-SSE and NNE-SSW and different senses of motion. The obtained magnetic foliations (k1-k2) are sub-parallel (within ∼20°) to the fault planes. Based on rock magnetic and geochemical analyses, we interpret the AMS fabrics as the product of both shape and crystallographic anisotropy of the dolostones. Preferred shape alignment evolves due to mechanical rotation of subordinate particles and rock fragments at the fault core. Preferred crystallographic orientation results from elevated frictional heating (>300 °C) during faulting, which enhances c-axes alignment in the cement-supported dolomite breccia due to crystal-plastic processes. The penetrative deformation within fault zones resulted from the local, fault-related strain field and does not reflect the regional strain field. The analyzed AMS fabrics together with fault-plane kinematics provide valuable information on faulting characteristics in the uppermost crust.

  10. DATA TRANSFORMATION OF FAULT TREE BY USING MATRIX OPERATION

    Institute of Scientific and Technical Information of China (English)

    Cai Jiakun; Chen Jinshui

    2003-01-01

    On the base of study of the correlation of fault tree's main data-minimum cut sets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets, transformation method among main data are found, i.e. the transformation can be realized by the operation of cut sets matrixes. This method provides a new way to reduce "NP" difficulty and simplify FTA.

  11. A Coordinate Transformation for Unsteady Boundary Layer Equations

    Directory of Open Access Journals (Sweden)

    Paul G. A. CIZMAS

    2011-12-01

    Full Text Available This paper presents a new coordinate transformation for unsteady, incompressible boundary layer equations that applies to both laminar and turbulent flows. A generalization of this coordinate transformation is also proposed. The unsteady boundary layer equations are subsequently derived. In addition, the boundary layer equations are derived using a time linearization approach and assuming harmonically varying small disturbances.

  12. First-principles Calculations of Twin-boundary and Stacking-fault Energies in Magnesium

    Science.gov (United States)

    2010-01-01

    The interfacial energies of twin boundaries and stacking faults in metal magnesium have been calculated using first-principles supercell approach...Four types of twin boundaries and two types of stacking faults are investigated, namely, those due to the mirror reflection, the mirror glide and the

  13. Gravity field over the Sea of Galilee: Evidence for a composite basin along a transform fault

    Science.gov (United States)

    Ben-Avraham, Zvi; ten Brink, Uri; Bell, Robin; Reznikov, Margaret

    1996-01-01

    The Sea of Galilee (Lake Kinneret) is located at the northern portion of the Kinneret-Bet Shean basin, in the northern Dead Sea transform. Three hundred kilometers of continuous marine gravity data were collected in the lake and integrated with land gravity data to a distance of more than 20 km around the lake. Analyses of the gravity data resulted in a free-air anomaly map, a variable density Bouguer anomaly map, and a horizontal first derivative map of the Bouguer anomaly. These maps, together with gravity models of profiles across the lake and the area south of it, were used to infer the geometry of the basins in this region and the main faults of the transform system. The Sea of Galilee can be divided into two units. The southern half is a pull-apart that extends to the Kinarot Valley, south of the lake, whereas the northern half was formed by rotational opening and transverse normal faults. The deepest part of the basinal area is located well south of the deepest bathymetric depression. This implies that the northeastern part of the lake, where the bathymetry is the deepest, is a young feature that is actively subsiding now. The pull-apart basin is almost symmetrical in the southern part of the lake and in the Kinarot Valley south of the lake. This suggests that the basin here is bounded by strike-slip faults on both sides. The eastern boundary fault extends to the northern part of the lake, while the western fault does not cross the northern part. The main factor controlling the structural complexity of this area is the interaction of the Dead Sea transform with a subperpendicular fault system and rotated blocks.

  14. Spatio-temporal mapping of plate boundary faults in California using geodetic imaging

    Science.gov (United States)

    Donnellan, Andrea; Arrowsmith, Ramon; DeLong, Stephen B.

    2017-01-01

    The Pacific–North American plate boundary in California is composed of a 400-km-wide network of faults and zones of distributed deformation. Earthquakes, even large ones, can occur along individual or combinations of faults within the larger plate boundary system. While research often focuses on the primary and secondary faults, holistic study of the plate boundary is required to answer several fundamental questions. How do plate boundary motions partition across California faults? How do faults within the plate boundary interact during earthquakes? What fraction of strain accumulation is relieved aseismically and does this provide limits on fault rupture propagation? Geodetic imaging, broadly defined as measurement of crustal deformation and topography of the Earth’s surface, enables assessment of topographic characteristics and the spatio-temporal behavior of the Earth’s crust. We focus here on crustal deformation observed with continuous Global Positioning System (GPS) data and Interferometric Synthetic Aperture Radar (InSAR) from NASA’s airborne UAVSAR platform, and on high-resolution topography acquired from lidar and Structure from Motion (SfM) methods. Combined, these measurements are used to identify active structures, past ruptures, transient motions, and distribution of deformation. The observations inform estimates of the mechanical and geometric properties of faults. We discuss five areas in California as examples of different fault behavior, fault maturity and times within the earthquake cycle: the M6.0 2014 South Napa earthquake rupture, the San Jacinto fault, the creeping and locked Carrizo sections of the San Andreas fault, the Landers rupture in the Eastern California Shear Zone, and the convergence of the Eastern California Shear Zone and San Andreas fault in southern California. These examples indicate that distribution of crustal deformation can be measured using interferometric synthetic aperture radar (InSAR), Global Navigation

  15. Stress fields of the San Andreas and Queen Charlotte transform faults

    Science.gov (United States)

    Kilty, Kevin T.

    1981-08-01

    Analytic solutions to the stress fields resulting from the San Andreas and Queen Charlotte transform faults may be found by applying conformal mappings to the generalized plane stress solution of stresses in a half-plane. The mean stress fields (one-half the trace of the stress tensor) found in this manner show a similarity to the deformation found in western Canada and the western United States. The results refute the hypothesis that Alaska acts as a continental buttress against deformation of the Canadian Cordillera. Moreover, these results imply that the differences in the tectonics of major transform boundaries are caused primarily by differences in lithospheric structure and differences in stress distribution along the plate boundaries.

  16. Software System for Finding the Incipient Faults in Power Transformers

    Directory of Open Access Journals (Sweden)

    Nikolina Petkova

    2015-05-01

    Full Text Available In this paper a new software system for finding of incipient faultsis presented.An experiment is made with real measurement of partial discharge(PD that appeared in power transformer. The software system usesacquisition data to define the real state of this transformer. One of the most important criteria for the power transformer’s state is the presence of partial discharges. The wave propagation caused by partial discharge depends on scheme of the winding and construction of the power equipment. In all cases, the PD source had a specific position so the wave measured from the PD –coupling device had a specific waveform. The waveform is different when PDcoupling device is put on a specific place. The waveform and the time of propagation are criteria for the localization of the source of incipient faults in the volume of power transformer.

  17. Armenia-To Trans-Boundary Fault: AN Example of International Cooperation in the Caucasus

    Science.gov (United States)

    Karakhanyan, A.; Avagyan, A.; Avanesyan, M.; Elashvili, M.; Godoladze, T.; Javakishvili, Z.; Korzhenkov, A.; Philip, S.; Vergino, E. S.

    2012-12-01

    Studies of a trans-boundary active fault that cuts through the border of Armenia to Georgia in the area of the Javakheti volcanic highland have been conducted since 2007. The studies have been implemented based on the ISTC 1418 and NATO SfP 983284 Projects. The Javakheti Fault is oriented to the north-northwest and consists of individual segments displaying clear left-stepping trend. Fault mechanism is represented by right-lateral strike-slip with normal-fault component. The fault formed distinct scarps, deforming young volcanic and glacial sediments. The maximum-size displacements are recorded in the central part of the fault and range up to 150-200 m by normal fault and 700-900 m by right-lateral strike-slip fault. On both flanks, fault scarps have younger appearance, and displacement size there decreases to tens of meters. Fault length is 80 km, suggesting that maximum fault magnitude is estimated at 7.3 according to the Wells and Coppersmith (1994) relation. Many minor earthquakes and a few stronger events (1088, Mw=6.4, 1899 Mw=6.4, 1912, Mw=6.4 and 1925, Mw=5.6) are associated with the fault. In 2011/2012, we conducted paleoseismological and archeoseismological studies of the fault. By two paleoseismological trenches were excavated in the central part of the fault, and on its northern and southern flanks. The trenches enabled recording at least three strong ancient earthquakes. Presently, results of radiocarbon age estimations of those events are expected. The Javakheti Fault may pose considerable seismic hazard for trans-boundary areas of Armenia and Georgia as its northern flank is located at the distance of 15 km from the Baku-Ceyhan pipeline.

  18. Paleoseismic investigations along the Peel Boundary Fault : Geological setting, site selection and trenching results

    NARCIS (Netherlands)

    Berg, M. van den; Vanneste, K.; Dost, B.; Lokhorst, A.; Eijk, M. van; Verbeeck, K.

    2002-01-01

    On the basis of a multidisciplinary approach we have unraveled the palaeo-earthquake history of a trenched section across the Peel Boundary Fault. The area shows at present one of the largest contrasts in relative motion on both sides of the fault on the basis of repeated levelling. The geological

  19. Fault location in underground cables using ANFIS nets and discrete wavelet transform

    Directory of Open Access Journals (Sweden)

    Shimaa Barakat

    2014-12-01

    Full Text Available This paper presents an accurate algorithm for locating faults in a medium voltage underground power cable using a combination of Adaptive Network-Based Fuzzy Inference System (ANFIS and discrete wavelet transform (DWT. The proposed method uses five ANFIS networks and consists of 2 stages, including fault type classification and exact fault location. In the first part, an ANFIS is used to determine the fault type, applying four inputs, i.e., the maximum detailed energy of three phase and zero sequence currents. Other four ANFIS networks are utilized to pinpoint the faults (one for each fault type. Four inputs, i.e., the maximum detailed energy of three phase and zero sequence currents, are used to train the neuro-fuzzy inference systems in order to accurately locate the faults on the cable. The proposed method is evaluated under different fault conditions such as different fault locations, different fault inception angles and different fault resistances.

  20. Resource requirements for a fault-tolerant quantum Fourier transform

    Science.gov (United States)

    Goto, Hayato; Nakamura, Satoshi; Kujiraoka, Mamiko; Ichimura, Kouichi

    2015-03-01

    The quantum Fourier transform (QFT) is a basic subroutine for most quantum algorithms providing an exponential speedup over classical ones. We investigate resource requirements for a fault-tolerant QFT. To implement single-qubit rotations for a QFT in a fault-tolerant manner, we examine three types of approaches: ancilla-free gate synthesis, ancilla-assisted gate synthesis, and state distillation. While the gate synthesis approximates single-qubit rotations with basic quantum operations, the state distillation enables to perform specific single-qubit rotations required for the QFT exactly. It is unknown, however, which approach is better for the QFT. We estimated the resource requirement for a QFT in each case, where the resource is measured by the total number of the π / 8 gates denoted by T, which is called the T count. Contrary to the initial expectation, the total T count for the state distillation is considerably larger than those for the ancilla-free and ancilla-assisted gate synthesis. Thus, we conclude that the ancilla-assisted gate synthesis is the best for a fault-tolerant QFT so far.

  1. A Method for Incipient Fault Diagnosis of Roller Bearings Based on the Wavelet Transform Correlation Filter and Hilbert Transform

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing-hu; QIU Jing; LIU Guan-jun

    2007-01-01

    Noise is the biggest obstacle that makes the incipient fault diagnosis results of roller bearings uncorrected; a new method for diagnosing incipient fault of roller bearings based on the Wavelet Transform Correlation Filter and Hilbert Transform was proposed. First, the weak fault information features are picked up from the roller bearings fault vibration signals by use of a de-noising characteristic of the Wavelet Transform Correlation Filter as the preprocessing of the Hilbert Envelope Analysis. Then, in order to get fault features frequency, de-noised wavelet coefficients of high scales which represent high frequency signal were analyzed by Hilbert Envelope Spectrum Analysis. The simulation signals and diagnosing examples analysis results reveal that the proposed method is more effective than the method of direct wavelet coefficients-Hilbert Transform in de-noising and clarifying roller bearing incipient fault.

  2. Systematic Underestimation of Earthquake Magnitudes from Large Intracontinental Reverse Faults: Historical Ruptures Break Across Segment Boundaries

    Science.gov (United States)

    Rubin, C. M.

    1996-01-01

    Because most large-magnitude earthquakes along reverse faults have such irregular and complicated rupture patterns, reverse-fault segments defined on the basis of geometry alone may not be very useful for estimating sizes of future seismic sources. Most modern large ruptures of historical earthquakes generated by intracontinental reverse faults have involved geometrically complex rupture patterns. Ruptures across surficial discontinuities and complexities such as stepovers and cross-faults are common. Specifically, segment boundaries defined on the basis of discontinuities in surficial fault traces, pronounced changes in the geomorphology along strike, or the intersection of active faults commonly have not proven to be major impediments to rupture. Assuming that the seismic rupture will initiate and terminate at adjacent major geometric irregularities will commonly lead to underestimation of magnitudes of future large earthquakes.

  3. Continuity of subsurface fault structure revealed by gravity anomaly: the eastern boundary fault zone of the Niigata plain, central Japan

    Science.gov (United States)

    Wada, Shigeki; Sawada, Akihiro; Hiramatsu, Yoshihiro; Matsumoto, Nayuta; Okada, Shinsuke; Tanaka, Toshiyuki; Honda, Ryo

    2017-01-01

    We have investigated gravity anomalies around the Niigata plain, which is a sedimentary basin in central Japan bounded by mountains, to examine the continuity of subsurface fault structures of a large fault zone—the eastern boundary fault zone of the Niigata plain (EBFZNP). The features of the Bouguer anomaly and its first horizontal and vertical derivatives clearly illustrate the EBFZNP. The steep first horizontal derivative and the zero isoline of the vertical derivative are clearly recognized along the entire EBFZNP over an area that shows no surface topographic features of an active fault. Two-dimensional density structure analyses also confirm a relationship between the two first derivatives and the subsurface fault structure. Therefore, we conclude that the length of the EBFZNP as an active fault extends to 56 km, which is longer than previously estimated. This length leads to an estimation of a moment magnitude of 7.4 of an expected earthquake from the EBFZNP.[Figure not available: see fulltext.

  4. Large-scale right-slip displacement on the East San Francisco Bay Region fault system, California: Implications for location of late Miocene to Pliocene Pacific plate boundary

    Science.gov (United States)

    McLaughlin, R.J.; Sliter, W.V.; Sorg, D.H.; Russell, P.C.; Sarna-Wojcicki, A. M.

    1996-01-01

    A belt of northwardly younging Neogene and Quaternary volcanic rocks and hydrothermal vein systems, together with a distinctive Cretaceous terrane of the Franciscan Complex (the Permanente terrane), exhibits about 160 to 170 km of cumulative dextral offset across faults of the East San Francisco Bay Region (ESFBR) fault system. The offset hydrothermal veins and volcanic rocks range in age from .01 Ma at the northwest end to about 17.6 Ma at the southeast end. In the fault block between the San Andreas and ESFBR fault systems, where volcanic rocks are scarce, hydrothermal vein system ages clearly indicate that the northward younging thermal overprint affected these rocks beginning about 18 Ma. The age progression of these volcanic rocks and hydrothermal vein systems is consistent with previously proposed models that relate northward propagation of the San Andreas transform to the opening of an asthenospheric window beneath the North American plate margin in the wake of subducting lithosphere. The similarity in the amount of offset of the Permanente terrane across the ESFBR fault system to that derived by restoring continuity in the northward younging age progression of volcanic rocks and hydrothermal veins suggests a model in which 80-110 km of offset are taken up 8 to 6 Ma on a fault aligned with the Bloomfield-Tolay-Franklin-Concord-Sunol-Calaveras faults. An additional 50-70 km of cumulative slip are taken up ??? 6 Ma by the Rogers Creek-Hayward and Concord-Franklin-Sunol-Calaveras faults. An alternative model in which the Permanente terrane is offset about 80 km by pre-Miocene faults does not adequately restore the distribution of 8-12 Ma volcanic rocks and hydrothermal veins to a single northwardly younging age trend. If 80-110 km of slip was taken up by the ESFBR fault system between 8 and 6 Ma, dextral slip rates were 40-55 mm/yr. Such high rates might occur if the ESFBR fault system rather than the San Andreas fault acted as the transform margin at this time

  5. Coefficient of Variation Estimates for the Plate Boundary Fault System of California

    Science.gov (United States)

    Biasi, G. P.; Scharer, K. M.

    2015-12-01

    The number of high-quality paleoseismic records on major strike-slip faults of California has increased in recent years to the point that patterns in earthquake recurrence are emerging. The degree of predictability in time intervals between ground-rupturing earthquakes can be measured by the CoV (coefficient of variation). The CoV approximately normalizes for mean recurrence, and is thus useful to isolate the temporal variability of earthquake records. CoV estimates are themselves uncertain because input dates are actually probability distributions and because paleoseismic records are short and not necessarily representative samples from the underlying recurrence distribution. Radiocarbon dating uncertainty can be incorporated by sampling from event PDFs and compiling sample CoV estimates. Uncertainty due to the brevity of the site event record is larger, and neglect of it can lead to improbable estimates. Long records are now available on the San Andreas and San Jacinto faults in Southern California, and the San Andreas and Hayward faults in northern California. These faults accommodate most of the Pacific-North American relative plate motion in their respective regions. CoV estimates from sites with 8 or more events cluster around 0.63, but are as low as 0.4 for the southern Hayward fault. Sites with fewer events give similar estimates, though with lower resolution. The one prominent outlier, Burro Flats, with a CoV near 1.0, is in a region of severe fault complexity and rapid fault-normal compression. Quasi-periodic recurrence is emerging as a general property for these plate boundary faults. Some individual site records allow that, at low probabilities, recurrence could be random in time. When the ensemble is considered together, however, it is improbable that we would see the observed degree of agreement among boundary fault paleoseismic records; the more likely explanation is that quasi-periodic recurrence is a real property of the boundary fault system.

  6. Distributed Plate Boundary Deformation Across the San Andreas Fault System, Central California

    Science.gov (United States)

    Dyson, M.; Titus, S. J.; Demets, C.; Tikoff, B.

    2007-12-01

    Plate boundaries are now recognized as broad zones of complex deformation as opposed to narrow zones with discrete offsets. When assessing how plate boundary deformation is accommodated, both spatially and temporally, it is therefore crucial to understand the relative contribution of the discrete and distributed components of deformation. The creeping segment of the San Andreas fault is an ideal location to study the distribution of plate boundary deformation for several reasons. First, the geometry of the fault system in central California is relatively simple. Plate motion is dominated by slip along the relatively linear strike-slip San Andreas fault, but also includes lesser slip along the adjacent and parallel Hosgri-San Gregorio and Rinconada faults, as well as within the borderlands between the three fault strands. Second, the aseismic character of the San Andreas fault in this region allows for the application of modern geodetic techniques to assess creep rates along the fault and across the region. Third, geologic structures within the borderlands are relatively well-preserved allowing comparison between modern and ancient rates and styles of deformation. Continuous GPS stations, alignment arrays surveys, and other geodetic methods demonstrate that approximately 5 mm/yr of distributed slip is accumulated (on top of the fault slip rate) across a 70-100 km wide region centered on the San Andreas fault. New campaign GPS data also suggest 2-5 mm/yr of deformation in the borderlands. These rates depend on the magnitude of the coseismic and postseismic corrections that must be made to our GPS time series to compensate for the 2003 San Simeon and 2004 Parkfield earthquakes, which rupture faults outside, but near the edges of our GPS network. The off-fault deformation pattern can be compared to the style of permanent deformation recorded in the geologic record. Fold and thrust belts in the borderlands are better developed in the Tertiary sedimentary rocks west of

  7. Transformation of fault slip modes in laboratory experiments

    Science.gov (United States)

    Martynov, Vasilii; Alexey, Ostapchuk; Markov, Vadim

    2017-04-01

    Slip mode of crust fault can vary because of many reasons. It's well known that fault structure, material of fault gouge, pore fluid et al. in many ways determines slip modes from creep and slow slip events to mega-earthquakes [1-3]. Therefore, the possibility of fault slip transformation due to external action is urgent question. There is popular and developing approach of fluid injection into central part of fault. The phenomenon of earthquakes induced due to pumping of water was investigated on small and large scales [4, 5]. In this work the laboratory experiments were conducted to study the evolution of the experimental fault slip when changing the properties of the interstitial fluid. The scheme of experiments is the classical slider-model set-up, in which the block under the shear force slips along the interface. In our experiments the plexiglas block 8x8x3 cm3 in size was put on the plexiglas base. The contact of the blocks was filled with a thin layer (about 3 mm thick) of a granular material. The normal load varied from 31 to 156 kPa. The shear load was applied through a spring with stiffness 60 kN/m, and the rate of spring deformation was 20 or 5 mcm/s. Two parameters were recorded during experiments: the shear force acting on the upper block (with an accuracy of 1 N) and its displacement relatively the base (with an accuracy of 0.1 μm). The gouge was composed of quartz sand (97.5%) and clay (2.5%). As a moisturizer were used different fluids with viscosity varying from 1 to 103 mPa x s. Different slip modes were simulated during slider-experiments. In our experiments slip mode is the act of instability manifested in an increase of slip velocity and a drop of shear stress acting on a movable block. The amplitude of a shear stress drop and the peak velocity of the upper block were chosen as the characteristics of the slip mode. In the laboratory experiments, slip events of one type can be achieved either as regularly recurring (regular mode) or as random

  8. Removal of stacking-fault tetrahedra by twin boundaries in nanotwinned metals.

    Science.gov (United States)

    Yu, K Y; Bufford, D; Sun, C; Liu, Y; Wang, H; Kirk, M A; Li, M; Zhang, X

    2013-01-01

    Stacking-fault tetrahedra are detrimental defects in neutron- or proton-irradiated structural metals with face-centered cubic structures. Their removal is very challenging and typically requires annealing at very high temperatures, incorporation of interstitials or interaction with mobile dislocations. Here we present an alternative solution to remove stacking-fault tetrahedra discovered during room temperature, in situ Kr ion irradiation of epitaxial nanotwinned Ag with an average twin spacing of ~8 nm. A large number of stacking-fault tetrahedra were removed during their interactions with abundant coherent twin boundaries. Consequently the density of stacking-fault tetrahedra in irradiated nanotwinned Ag was much lower than that in its bulk counterpart. Two fundamental interaction mechanisms were identified, and compared with predictions by molecular dynamics simulations. In situ studies also revealed a new phenomenon: radiation-induced frequent migration of coherent and incoherent twin boundaries. Potential migration mechanisms are discussed.

  9. Fault and graben growth along active magmatic divergent plate boundaries in Iceland and Ethiopia

    KAUST Repository

    Trippanera, D.

    2015-10-08

    Recent studies highlight the importance of annual-scale dike-induced rifting episodes in developing normal faults and graben along the active axis of magmatic divergent plate boundaries (MDPB). However, the longer-term (102-105 years) role of diking on the cumulative surface deformation and evolution of MDPB is not yet well understood. To better understand the longer-term normal faults and graben along the axis of MDPB, we analyze fissure swarms in Iceland and Ethiopia. We first focus on the simplest case of immature fissure swarms, with single dike-fed eruptive fissures; these consist of a <1 km wide graben bordered by normal faults with displacement up to a few meters, consistent with theoretical models and geodetic data. A similar structural pattern is found, with asymmetric and multiple graben, within wider mature fissure swarms, formed by several dike-fed eruptive fissures. We then consider the lateral termination of normal faults along these graben, to detect their upward or downward propagation. Most faults terminate as open fractures on flat surface, suggesting downward fault propagation; this is consistent with recent experiments showing dike-induced normal faults propagating downward from the surface. However, some normal faults also terminate as open fractures on monoclines, which resemble fault propagation folds; this suggests upward propagation of reactivated buried faults, promoted by diking. These results suggest that fault growth and graben development, as well as the longer-term evolution of the axis of MDPB, may be explained only through dike emplacement and that any amagmatic faulting is not necessary.

  10. CONTINUOUS WAVELET TRANSFORM OF TURBULENT BOUNDARY LAYER FLOW

    Institute of Scientific and Technical Information of China (English)

    LIU Ying-zheng; KE Feng; CHEN Han-ping

    2005-01-01

    The spatio-temporal characteristics of the velocity fluctuations in a fully-developed turbulent boundary layer flow was investigated using hotwire. A low-speed wind tunnel was established. The experimental data was extensively analyzed in terms of continuous wavelet transform coefficients and their auto-correlation. The results yielded a potential wealth of information on inherent characteristics of coherent structures embedded in turbulent boundary layer flow. Spatial and temporal variations of the low- and high- frequency motions were revealed.

  11. NEW METHOD FOR WEAK FAULT FEATURE EXTRACTION BASED ON SECOND GENERATION WAVELET TRANSFORM AND ITS APPLICATION

    Institute of Scientific and Technical Information of China (English)

    Duan Chendong; He Zhengjia; Jiang Hongkai

    2004-01-01

    A new time-domain analysis method that uses second generation wavelet transform (SGWT) for weak fault feature extraction is proposed. To extract incipient fault feature, a biorthogonal wavelet with the characteristics of impact is constructed by using SGWT. Processing detail signal of SGWT with a sliding window devised on the basis of rotating operation cycle, and extracting modulus maximum from each window, fault features in time-domain are highlighted. To make further analysis on the reason of the fault, wavelet package transform based on SGWT is used to process vibration data again. Calculating the energy of each frequency-band, the energy distribution features of the signal are attained. Then taking account of the fault features and the energy distribution, the reason of the fault is worked out. An early impact-rub fault caused by axis misalignment and rotor imbalance is successfully detected by using this method in an oil refinery.

  12. The boundary conditions for point transformed electromagnetic invisibility cloaks

    Energy Technology Data Exchange (ETDEWEB)

    Weder, Ricardo [Departamento de Metodos Matematicos y Numericos, Instituto de Investigaciones en Matematicas Aplicadas y en Sistemas, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-726, Mexico DF 01000 (Mexico)], E-mail: weder@servidor.unam.mx

    2008-10-17

    In this paper we study point transformed electromagnetic invisibility cloaks in transformation media that are obtained by transformation from general anisotropic media. We assume that there are several point transformed electromagnetic cloaks located in different points in space. Our results apply in particular to the first-order invisibility cloaks introduced by Pendry et al and to the high-order invisibility cloaks introduced by Hendi et al and by Cai et al. We identify the appropriate cloaking boundary conditions that the solutions of Maxwell equations have to satisfy at the outside, {partial_derivative}K{sub +}, and at the inside, {partial_derivative}K{sub -}, of the boundary of the cloaked object K in the case where the permittivity and the permeability are bounded below and above in K. Namely, that the tangential components of the electric and the magnetic fields have to vanish at {partial_derivative}K{sub +}-which is always true-and that the normal components of the curl of the electric and the magnetic fields have to vanish at {partial_derivative}K{sub -}. These results are proven requiring that energy be conserved. In the case of one spherical cloak with a spherically stratified K and a radial current at {partial_derivative}K we verify by an explicit calculation that our cloaking boundary conditions are satisfied and that cloaking of active devices holds, even if the current is at the boundary of the cloaked object. As we prove our results for media that are obtained by transformation from general anisotropic media, our results apply to the cloaking of objects with passive and active devices contained in general anisotropic media, in particular to objects with passive and active devices contained inside general crystals. Our results suggest a method to enhance cloaking in the approximate transformation media that are used in practice. Namely, to coat the boundary of the cloaked object (the inner boundary of the cloak) with a material that imposes the

  13. Detailed Simulation of Transformer Internal Fault in Power System by Diakoptical Concept

    Directory of Open Access Journals (Sweden)

    KOUHSARI, S. M.

    2010-08-01

    Full Text Available This paper presents a novel method for modeling internal faults in a power transformer. This method uses a distributed computing approach for analysis of internal fault in transient stability (T/S studies of electrical networks using Diakoptics and large change sensitivity (LCS concepts. The combination of these concepts by phase frame model of transformer will be used here to develop an internal fault simulation of transformers. This approach leads to a model which is compatible with commercial phasor-based software packages. Consequently, it enables calculation of fault currents in any branch of the network due to a winding fault of a power transformer. The proposed method is implemented successfully and validated by time domain software and GEC group measurement results.

  14. Mine-hoist fault-condition detection based on the wavelet packet transform and kernel PCA

    Institute of Scientific and Technical Information of China (English)

    XIA Shi-xiong; NIU Qiang; ZHOU Yong; ZHANG Lei

    2008-01-01

    A new algorithm was developed to correctly identify fault conditions and accurately monitor fault development in a mine hoist. The new method is based on the Wavelet Packet Transform (WPT) and kernel PCA (Kernel Principal Component Analysis, KPCA). For non-linear monitoring systems the key to fault detection is the extracting of main features. The wavelet packet transform is a novel technique of signal processing that possesses excellent characteristics of time-frequency localization. It is suitable for analysing time-varying or transient signals. KPCA maps the original input features into a higher dimension feature space through a non-linear mapping. The principal components are then found in the higher dimension feature space. The KPCA transformation was applied to extracting the main nonlinear features from experimental fault feature data after wavelet packet transformation. The results show that the proposed method affords credible fault detection and identification.

  15. Active faulting and transpression tectonics along the plate boundary in North Africa

    OpenAIRE

    Mustapha Meghraoui; Silvia Pondrelli

    2012-01-01

    International audience; We present a synthesis of the active tectonics of the northern Atlas Mountains , and suggest a kinematic model of transpression and block rotation that illustrates the mechanics of this section of the Africa–Eurasia plate boundary. Neotectonic structures and significant shallow seismicity (with Mw >5.0) indicate that coeval E-W-trending, right-lateral faulting and NE-SW, thrust-related folding result from oblique convergence at the plate boundary, which forms a transpr...

  16. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Directory of Open Access Journals (Sweden)

    Hazlee Azil Illias

    Full Text Available It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN and particle swarm optimisation (PSO techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  17. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Science.gov (United States)

    Illias, Hazlee Azil; Chai, Xin Rui; Abu Bakar, Ab Halim; Mokhlis, Hazlie

    2015-01-01

    It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA) has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN) and particle swarm optimisation (PSO) techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  18. Evolving seismogenic plate boundary megathrust and mega-splay faults in subduction zone (Invited)

    Science.gov (United States)

    Kimura, G.; Hamahashi, M.; Fukuchi, R.; Yamaguchi, A.; Kameda, J.; Kitamura, Y.; Hashimoto, Y.; Hamada, Y.; Saito, S.; Kawasaki, R.

    2013-12-01

    Understanding the fault mechanism and its relationship to the sesimo-tsunamigenesis is a key of the scientific targets of subduction zone and therefore NantroSEIZE project of IODP and future new drilling project of International Ocean Discovery Program keeps focusing on that. Mega-splay fault branched from plate boundary megathrust in subduction zone is located around the border between outer and inner wedges and is considered to cause great earthquake and tsunami such as 1960 Alaska earthquake, 1944 and 1946 Nankai-Tonankai earthquakes, and 2004 Sumatra earthquakes. Seismic reflection studies for the mega-splay fault in 2D and 3D in the Nankai forearc present the reflector with negative or positive polarities with various amplitudes and suggest complicated petrophysical properties and condition of the fault and its surroundings. The Nankai mega-splay fault at a depth of ~5km is going to be drilled and cored by NantroSEIZE experiments and is expected for great progress of understanding of the fault mechanics. Before drilling the really targeted seismogenic fault, we are conducting many exercises of geophysical and geological observations. The core-log-seismic integrated exercise for the exhumed mega-splay fault by drilling was operated for the Nobeoka thrust in the Shimanto Belt, Kyushu, Japan. The Nobeoka thrust was once buried in the depth >~10km and suffered maximum temperature >~300 dgree C. As the core recovery is ~99%, perfect correlation between the core and logging data is possible. Thickness of the fault zone is >200 m with a ~50 cm thick central fault core dividing the phyllitic hanging wall and the footwall of broken-melange like cataclasite. A-few-meter-thick discrete damage zones with fault cores are recognized by difference in physical properties and visual deformation textures at several horizons in the fault zone. Host rocks for those damaged zones are completely lithified cataclasites with abundant mineral veins, which record the older and deeper

  19. EMD and Wavelet Transform Based Fault Diagnosis for Wind Turbine Gear Box

    Directory of Open Access Journals (Sweden)

    Qingyu Yang

    2013-01-01

    Full Text Available Wind turbines are mainly located in harsh environment, and the maintenance is therefore very difficult. The wind turbine faults are mostly from the gear box, and the fault signal is generally nonlinear and nonstationary. The traditional fault diagnosis methods such as Fast Fourier transform (FFT and the inverted frequency spectrum identification method based on FFT are not satisfactory in processing this kind of signal. This paper proposes a hybrid fault diagnosis method which combines the empirical mode decomposition (EMD and wavelet transform. The vibration signal is analyzed through wavelet transform, and the aliasing in high-frequency signals is then addressed by conducting EMD to the original signals. The experimental results based on a specific wind turbine gear box demonstrate that this method can diagnose the faults and locate their positions accurately.

  20. Double Fault Detection of Cone-Shaped Redundant IMUs Using Wavelet Transformation and EPSA

    Directory of Open Access Journals (Sweden)

    Wonhee Lee

    2014-02-01

    Full Text Available A model-free hybrid fault diagnosis technique is proposed to improve the performance of single and double fault detection and isolation. This is a model-free hybrid method which combines the extended parity space approach (EPSA with a multi-resolution signal decomposition by using a discrete wavelet transform (DWT. Conventional EPSA can detect and isolate single and double faults. The performance of fault detection and isolation is influenced by the relative size of noise and fault. In this paper; the DWT helps to cancel the high frequency sensor noise. The proposed technique can improve low fault detection and isolation probability by utilizing the EPSA with DWT. To verify the effectiveness of the proposed fault detection method Monte Carlo numerical simulations are performed for a redundant inertial measurement unit (RIMU.

  1. Wavelet Transform and Neural Networks in Fault Diagnosis of a Motor Rotor

    Institute of Scientific and Technical Information of China (English)

    RONG Ming-xing

    2012-01-01

    In the motor fault diagnosis technique, vibration and stator current frequency components of detection are two main means. This article will discuss the signal detection method based on vibration fault. Because the motor vibration signal is a non-stationary random signal, fault signals often contain a lot of time-varying, burst proper- ties of ingredients. The traditional Fourier signal analysis can not effectively extract the motor fault characteristics, but are also likely to be rich in failure information but a weak signal as noise. Therefore, we introduce wavelet packet transforms to extract the fault characteristics of the signal information. Obtained was the result as the neural network input signal, using the L-M neural network optimization method for training, and then used the BP net- work for fault recognition. This paper uses Matlab software to simulate and confirmed the method of motor fault di- agnosis validity and accuracy

  2. The Queen Charlotte Fault, British Columbia: seafloor anatomy of a transform fault and its influence on sediment processes

    Science.gov (United States)

    Barrie, J. Vaughn; Conway, Kim W.; Harris, Peter T.

    2013-08-01

    The Queen Charlotte Fault Zone (QCFZ) off western Canada is the northern equivalent to the San Andreas Fault Zone, the Pacific-North American plate boundary. Geomorphologic expression and surface processes associated with the QCFZ system have been revealed in unprecedented detail by recent seabed mapping surveys. Convergence of the Pacific and North American plates along northern British Columbia is well known, but how the QCFZ accommodates this convergence is still a subject of controversy. The multibeam sonar bathymetry data reveal, for the first time, evidence of a fault valley with small depressions on the upper slope, offshore central Haida Gwaii (Queen Charlotte Islands). The depressions form where strike-slip right-step offsets have realigned the fault due to oblique convergence. Core stratigraphy and radiocarbon dating of sediments within the fault valley and small depressions suggest that these features are recent in origin. In addition, the development of the fault valley and dislocation of submarine canyons control sediment migration from the continental shelf through to the lower slope. This interpretation of the geomorphic expression of major plate tectonic processes along the QCFZ can now be tested with new surveys subsequent to the October 2012 magnitude 7.7 earthquake.

  3. Fault Detection in Complex Distribution Network Based on Hilbert-Huang Transform

    Directory of Open Access Journals (Sweden)

    Zhongjian Kang

    2013-01-01

    Full Text Available Traditional distribution network fault location methods often cannot be effectively applied for the structure of the branch in complex distribution network. A new accurate fault location for the single-phase-ground fault in complex distribution network with structure of the branch based on Hilbert-Huang transform was proposed in this paper. First, the distribution network was modeled. The faults on each branch were simulated. The energy characteristics under the branch in a particular frequency band were identified by HHT. Then these energy characteristics were used to train artificial neural networks (ANN.When the energy characteristics of actual fault are inputted, the trained neural network can output the malfunction branch. When the fault branch was determined, using the online fault feature matching method, combined with the genetic algorithm, the precise determination of the distance to fault location in the fault branch can be completed. With combinations of signal processing-Hilbert-Huang transform, artificial neural network and genetic algorithm, the entirely new method was proposed to deal with the problem of fault location in distribution network in this article. The results showed that the method has a good precision and apply to the small current grounding system.

  4. Calculation of a boundary layer with phase transformations

    Science.gov (United States)

    Dorosh, N. D.; Kharitonov, A. A.

    A method for the analysis of a laminar boundary layer with phase transformations is developed. It is noted that volume gas condensation can occur in the case of flow past a cooled surface, drops becoming aggregated in groups in the process of condensation. The concept of group density and concentration is proposed, and this approach is used to investigate a boundary layer near the stagnation point of a two-dimensional blunt body in a flow of molecular oxygen. Profiles of temperature, stream function, and concentration of liquid-oxygen droplet groups are determined for various values of the condensation rate.

  5. Interaction between transform faults and rift systems: a combined field and experimental approach

    Directory of Open Access Journals (Sweden)

    Alessandro eTibaldi

    2016-04-01

    Full Text Available We present a detailed field structural survey of the area of interaction between the active NW-striking transform Husavik-Flatey Fault (HFF and the N-S Theystareykir Fissure Swarm (TFS, in North Iceland, integrated by analogue scaled models. Field data contribute to a better understanding of how transform faults work, at a much higher detail than classical marine geophysical studies. Analogue experiments are conducted to analyse the fracture patterns resulting from different possible cases where transform faulting accompanies or postpones the rift motions; different tectonic block configurations are also considered. West of the intersection between the transform fault (HFF and the rift zone (TFS, the former splays with a gradual bending giving rise to a leading extensional imbricate fan. The westernmost structure of the rift, the N-S Gudfinnugja Fault (GF, is divided into two segments: the southern segment makes a junction with the HFF and is part of the imbricate fan; north of the junction instead, the northern GF appears right-laterally offset by about 20 m. Southeast of the junction, along the possible prolongation of the HFF across the TFS, the strike of the rift faults rotates in an anticlockwise direction, attaining a NNW-SSE orientation. Moreover, the TFS faults north of the HFF prolongation are fewer and have smaller offsets than those located to the south. Through the comparison between the structural data collected in the field at the HFF-TFS connection zone and a set of scaled experiments, we confirm a prolongation of the HFF through the rift, although here the transform fault has a much lower slip-rate than west of the junction. Our data suggest that transform fault terminations may be more complex than previously known, and propagate across a rift through a modification of the rift pattern.

  6. Series transformer based diode-bridge-type solid state fault current limiter

    Institute of Scientific and Technical Information of China (English)

    Amir HEIDARY; Hamid RADMANESH; Seyed Hamid FATHI; G B GHAREHPETIAN

    2015-01-01

    We propose a novel series transformer based diode-bridge-type solid state fault current limiter (SSFCL). To control the fault current, a series RLC branch is connected to the secondary side of an isolation series transformer. Based on this RLC branch, two current limiting modes are created. In the first mode, R and C are bypassed via a paralleled power electronic switch (insulated-gate bipolar transistor, IGBT) and L remains connected to the secondary side of the transformer as a DC reactor. In the second mode, the series reactor impedance is not enough to limit the fault current. In this case, the fault current can be con-trolled by selecting a proper on-off duration of the parallel IGBT, across the series damping resistor (R) and capacitor, which inserts high impedance into the line to limit the fault current. Then, by controlling the magnitude of the DC reactor current, the fault current is reduced and the voltage of the point of common coupling (PCC) is kept at an acceptable level. In addition, in the new SSFCL, the series RC branch, connected in parallel with the IGBT, serves as a snubber circuit for decreasing the transient recovery voltage (TRV) of the IGBT during on-off states. Therefore, the power quality indices can be improved. The measure-ment results of a built prototype are presented to support the simulation and theoretical studies. The proposed SSFCL can limit the fault current without any delay and successfully smooth the fault current waveform.

  7. New method for online interturn faults detection in power transformer with using probabilistic neural network

    Directory of Open Access Journals (Sweden)

    S. hajiaghasi

    2014-07-01

    Full Text Available In recent years with notice increase reliability in power system and Intelligent Systems and also notice that transformers are one of the main part of the transmission and distribution systems, online monitoring of these equipment in power system are require. In this paper, a new method for online interturn fault detection base on leakage flux in power transformer are propose. When an interturn fault occur the symmetry of flux destruction and leakage flux increase or decrease and for various location and severity of fault leakage flux is different and it can be used for fault detection. In this paper for measure these flux we using search coils that mounted on HV winding. To fault detection and classify we using probabilistic neural network. and for decrease the information volume PCA is used. The simulation results are compare and verified with experimental result and show that this propose method is very good.

  8. FAULT DIAGNOSIS APPROACH FOR ROLLER BEARINGS BASED ON EMPIRICAL MODE DECOMPOSITION METHOD AND HILBERT TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Yu Dejie; Cheng Junsheng; Yang Yu

    2005-01-01

    Based upon empirical mode decomposition (EMD) method and Hilbert spectrum, a method for fault diagnosis of roller bearing is proposed. The orthogonal wavelet bases are used to translate vibration signals of a roller bearing into time-scale representation, then, an envelope signal can be obtained by envelope spectrum analysis of wavelet coefficients of high scales. By applying EMD method and Hilbert transform to the envelope signal, we can get the local Hilbert marginal spectrum from which the faults in a roller bearing can be diagnosed and fault patterns can be identified. Practical vibration signals measured from roller bearings with out-race faults or inner-race faults are analyzed by the proposed method. The results show that the proposed method is superior to the traditional envelope spectrum method in extracting the fault characteristics of roller bearings.

  9. Diagnosis of airgap eccentricity fault in the inverter driven induction motor drives by transformative techniques

    Directory of Open Access Journals (Sweden)

    Khadim Moin Siddiqui

    2016-09-01

    Full Text Available In the present paper, the airgap eccentricity fault of the induction motor has been diagnosed by digital signal processing transformative techniques in the inverter driven induction motor drives. The airgap eccentricity fault has been diagnosed in the transient condition by time domain as well as time-frequency domain techniques with the help of a proposed dynamic simulation model. In the past, many signal processing techniques had been used for various induction motor fault detection purpose such as fast Fourier transform, Hilbert transform, short term Fourier transform, etc. But, all techniques faced some sort of disadvantages. Therefore, in this paper, all shortcomings of the previous used signal processing techniques have been solved by newly wavelet transform's approximation signal. The low frequency approximation signal has been used to diagnose the eccentricity fault in the transient condition. Therefore, early fault diagnosis of the motor is possible and averted the motor before reaching in the ruinous conditions. As a result, the industries may save large revenues and unexpected failure conditions. The obtained results clearly demonstrate that the developed diagnostic technique may reliably separate airgap eccentricity fault in many stages.

  10. A Combined Fault Diagnosis Method for Power Transformer in Big Data Environment

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available The fault diagnosis method based on dissolved gas analysis (DGA is of great significance to detect the potential faults of the transformer and improve the security of the power system. The DGA data of transformer in smart grid have the characteristics of large quantity, multiple types, and low value density. In view of DGA big data’s characteristics, the paper first proposes a new combined fault diagnosis method for transformer, in which a variety of fault diagnosis models are used to make a preliminary diagnosis, and then the support vector machine is used to make the second diagnosis. The method adopts the intelligent complementary and blending thought, which overcomes the shortcomings of single diagnosis model in transformer fault diagnosis, and improves the diagnostic accuracy and the scope of application of the model. Then, the training and deployment strategy of the combined diagnosis model is designed based on Storm and Spark platform, which provides a solution for the transformer fault diagnosis in big data environment.

  11. Ab initio study of antiphase boundaries and stacking faults in L12 and DO22 compounds

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1994-01-01

    We have performed ab initio calculations of the energies of antiphase boundaries as well as complex and superlattice intrinsic stacking faults in nine intermetallic compounds observed in the face-centered-cubic L1(2) and DO22 structures. The calculations were performed by means of a Green's funct......'s function technique based on the linear-muffin-tin-orbitals method within the tight-binding and atomic-sphere approximations....

  12. Geophysical surveys of the Queen Charlotte Fault plate boundary off SE Alaska: Preliminary results

    Science.gov (United States)

    Ten Brink, U. S.; Brothers, D. S.; Andrews, B. D.; Kluesner, J.; Haeussler, P. J.; Miller, N. C.; Watt, J. T.; Dartnell, P.; East, A. E.

    2016-12-01

    Recent multibeam sonar and high-resolution seismic surveys covering the northern 400-km-long segment of Queen Charlotte Fault off SE Alaska, indicate that the entire 50 mm/yr right-lateral Pacific-North America plate motion is currently accommodated by a single fault trace. The trace is remarkably straight rarely interrupted by step-overs, and is often Internal basin stratigraphy indicates possible southward migration of the step-over with time. Slight outward curving of the southern strand may suggest the presence of a deeper barrier there, which could have terminated the northward super-shear rupture of the 2013 M7.5 Craig Earthquake. Whether this possible barrier is related to the intersection of the Aja Fracture Zone with the plate boundary is unclear. No other surficial impediments to rupture were observed along the 315 km trace between this fault step-over and a 20° bend near Icy Point, where the fault extends onshore and becomes highly transpressional. An enigmatic oval depression, 1.5-2 km wide and 500 m deep, south of the step-over and a possible mud volcano north of the step-over, may attest to possible vigorous gas and fluid upwelling along the fault zone.

  13. Net Slip across the Ballenas Transform Fault Measured from Offset Ignimbrite Deposits

    Science.gov (United States)

    Stock, J. M.; Martín, A.; Chapman, A.; López-Martínez, M.

    2008-12-01

    The Ballenas Transform Fault in the Gulf of California separates the Baja California Peninsula (to the W on the Pacific Plate) from Isla Angel de la Guarda (to the E on the North America plate). This active right-lateral fault originated in a Pliocene plate boundary reorganization when part of the rift margin jumped westward into the Baja California peninsula, transferring Isla Angel de la Guarda from the Pacific plate to the North America plate. The net slip along the Ballenas transform fault system is expected to be less than the 250-300 km of post-Miocene opening of the northern Gulf of California basins. Here we constrain the net slip using geological similarities between the west coast of the island and the east coast of Baja California. Reconnaissance geological mapping on Isla Angel de la Guarda reveals the presence of a middle Miocene high-silica rhyolite ignimbrite with an Ar/Ar age of 11.8±0.2 Ma on sanidine. This deposit is preserved in a paleo-low in Cretaceous (?) granitic rocks in the central part of the island. The major and trace element compositions are similar to those of the Tuff of San Felipe, identified in Sonora and Baja California, but not previously recognized on Isla Angel de la Guarda. The deposit from the island exhibits a paleomagnetic remanence vector toward the SW and nearly horizontal, similar to that of the Tuff of San Felipe, and far outside of the expected paleomagnetic remanence direction. The ignimbrite on Isla Angel de la Guarda has an age younger than that previously reported for the Tuff of San Felipe, but within the range of ages from other outcrops of the Tuff of San Felipe in Sonora (Vidal-Solano et al., 2008). We correlate this ignimbrite to a similar unit preserved in isolated locations northwest of Cataviña on the Baja California peninsula, for which paleomagnetic work shows a very similar remanence direction. Using the SE limit of these outcrops against the granitic rocks in both locations yields an estimate of ~130

  14. INVESTIGATION OF MICROPROCESSOR TRANSFORMER CURRENT PROTECTION IN SHORT CIRCUIT FAULT MODES

    Directory of Open Access Journals (Sweden)

    M. S. Loman

    2014-01-01

    Full Text Available The paper presents an investigation on transformer current protection with blocking against magnetizing inrush current in short circuit fault modes. It has been shown that the proposed magnetizing in-rush current blocking algorithm can be implemented in microprocessor current protections of transformers.

  15. Support Vector Machine for Discrimination Between Fault and Magnetizing Inrush Current in Power Transformer

    Directory of Open Access Journals (Sweden)

    V. Malathi

    2007-01-01

    Full Text Available This study presents a novel technique based on Support Vector Machine (SVM for the classification of transient phenomena in power transformer. The SVM is a powerful method for statistical classification of data. The input data to this SVM for training comprises fault current and magnetizing inrush current. SVM classifier produces significant accuracy for classification of transient phenomena in power transformer.

  16. Implementation of Transformer Protection by Intelligent Electronic Device for Different Faults

    Directory of Open Access Journals (Sweden)

    Y V Aruna, Beena S

    2015-01-01

    Full Text Available Protection of power system equipments was traditionally done by using electromagnetic relay, static relays, and numerical relays. At present the microprocessor based relays are replacing the old Electromagnetic relays because of their high level accuracy and fast operation. RET670(Transformer protection relay , an IED (INTELLIGENT ELECTRONIC DEVICE provides fast and selective protection, monitoring, and control of all types of transformer. The configured IED is tested under different fault conditions simulated by using mobile test kit to ensure IED’s reliable operation on site. With preconfigured algorithms, the IED will automatically reconfigure the network in case of a fault, and a service restoration is carried out within milliseconds by giving trip signal to the corresponding Circuit breakers. On receiving the trip signal the circuit breaker operates providing quicker isolation of transformers under the fault condition. This enables to have a complete and an adequate protection to the specified power transformer.

  17. Induction motor rotor fault diagnosis method based on double PQ transformation

    Institute of Scientific and Technical Information of China (English)

    HUANG Jin; NIU Faliang; YANG Jiaqiang

    2007-01-01

    This Paper presents a new rotor fault diagnosis method for induction motors which is based on the double PQ transformation.We construct the PQ transformation matrix with the positive sequence fundamental voltage components and their Hilbert transformation as elements.The active power P and the reactive power Q are obtained through the PO transformation of the stator currents.As both P and Q are constant for a healthy motor,they are represented by a dot on the PQ plane.Whereas the P and Q for a rotor broken bar motor are represented by an ellipse because they comprise an additional frequency component 2sfs (s is the slip and js is the supply frequency).Thus,by distinguishing these two different patterns.the rotor broken bar fault is detected.We use the major radius of the ellipse as the fault indicator and the distance between the point of no-load condition and the center of the ellipse on the PQ plane as its normalization value.We thus arrive at the fault severity factor which is fairly independent of the load level and the inertia value of the induction motors.Experimental results have demonstrated that the proposed method is effective in identifying the rotor-broken-bars fault and at determining the severity of the fault.

  18. Transformer fault diagnosis based on chemical reaction optimization algorithm and relevance vector machine

    Directory of Open Access Journals (Sweden)

    Luo Wei

    2017-01-01

    Full Text Available Power transformer is one of the most important equipment in power system. In order to predict the potential fault of power transformer and identify the fault types correctly, we proposed a transformer fault intelligent diagnosis model based on chemical reaction optimization (CRO algorithm and relevance vector machine(RVM. RVM is a powerful machine learning method, which can solve nonlinear, high-dimensional classification problems with a limited number of samples. CRO algorithm has well global optimization and simple calculation, so it is suitable to solve parameter optimization problems. In this paper, firstly, a multi-layer RVM classification model was built by binary tree recognition strategy. Secondly, CRO algorithm was adopted to optimize the kernel function parameters which could enhance the performance of RVM classifiers. Compared with IEC three-ratio method and the RVM model, the CRO-RVM model not only overcomes the coding defect problem of IEC three-ratio method, but also has higher classification accuracy than the RVM model. Finally, the new method was applied to analyze a transformer fault case, Its predicted result accord well with the real situation. The research provides a practical method for transformer fault intelligent diagnosis and prediction.

  19. Modification of Duval Triangle for Diagnostic Transformer Fault through a Procedure of Dissolved Gases Analysis

    Directory of Open Access Journals (Sweden)

    Sobhy Serry Dessouky

    2016-08-01

        The evaluation is carried out on DGA data obtained from three different groups of transformers. A Matlab program was developed to automate the evaluation of  Duval Triangle graph to numerical modification, Also the fault gases can be generated due to oil decomposing effected by transformer over excitation which increasing thetransformer exciting current lead to rising the temperature inside transformer core beside the other causes.

  20. Thermal Constraints on the Rheology of Segmented Oceanic Transform Fault Systems

    Science.gov (United States)

    Wolfson-Schwehr, M. L.; Boettcher, M. S.; Behn, M. D.

    2012-12-01

    Mid-ocean ridge transform fault (RTF) systems may be comprised of two or more fault segments that are physically offset by an extensional basin or intra-transform spreading center. These intra-transform offsets affect the thermal structure underlying the transform fault and may act as barriers to rupture propagation. The seismogenic zone of RTFs is thermally controlled and limited by the 600°C isotherm, as evidenced by earthquake hypocentral depths and laboratory friction experiments. Observations from a recent ocean bottom seismic study found that RTF earthquakes rarely occur above ~2 km depth. These findings suggest that the seismogenic zone on RTFs likely extends from ~2 km to the 600°C isotherm. Here we utilize finite element analysis to model the thermal structure of a RTF system comprised of two transform fault segments separated by an extensional offset. The mantle is assumed to have a visco-plastic rheology to simulate brittle failure at temperatures bounded by areas of increased microseismicity, which act as barriers to large rupture propagation. Previously, we used well-located earthquakes recorded on a NOAA hydrophone array together with a relative relocation technique to determine the absolute positions for the five rupture patches on Discovery, which host 5.4 ≤ Mw ≤ 6.0 earthquakes. In this study, we combine absolute locations of the largest earthquakes, our detailed analysis of the fault trace of Discovery, and our thermal modeling results to assess how intra-transform offsets on Discovery affect the subsurface thermal structure. Along the 6 km intra-transform spreading center we find the 600°C isotherm is shallower than 2 km, suggesting that the thermal structure of this offset creates a rupture barrier between the adjoining fault segments. By contrast, intra-transform offsets surface trace of each segment only minimally affect the depth of the 600°C isotherm, resulting in a continuous seismogenic zone between the fault segments. This

  1. Current Limiting Performance of Three-Phase Concentric Transformer Type SFCL at Unbalanced Fault Conditions

    OpenAIRE

    Shirai, Yasuyuki; Noda, Syo; Yamabe, Kenta; Hattori, Keisuke; Baba, Jumpei; Nishihara, Taichi; Nitta, Tanzo; Kobayashi, Shinichi; Sato, Kenichi

    2013-01-01

    We have proposed a transformer type SFCL whose primary and secondary superconducting coils have rewound structure. The primary coil is connected to a power line. The secondary one is short-circuited and has fewer turns than the primary coil. For small fault current, only the secondary coil turns to normal state. Inductive component of impedance at the primary terminal mainly appears. For larger fault current, the primary coil also turns to normal state, resistive component additively appears....

  2. DETECTION OF INCIPIENT LOCALIZED GEAR FAULTS IN GEARBOX BY COMPLEX CONTINUOUS WAVELET TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    Han Zhennan; Xiong Shibo; Li Jinbao

    2003-01-01

    As far as the vibration signal processing is concerned, composition of vibration signal resulting from incipient localized faults in gearbox is too weak to be detected by traditional detecting technology available now. The method, which includes two steps: vibration signal from gearbox is first processed by synchronous average sampling technique and then it is analyzed by complex continuous wavelet transform to diagnose gear fault, is introduced. Two different kinds of faults in the gearbox, i.e.shaft eccentricity and initial crack in tooth fillet, are detected and distinguished from each other successfully.

  3. Constraining deformation at the lithosphere-asthenosphere boundary beneath the San Andreas fault with Sp phases

    Science.gov (United States)

    Fischer, K. M.; Ford, H. A.; Lekic, V.

    2013-12-01

    The geometry of deformation in the deep mantle lithosphere beneath strike-slip plate boundaries has been enigmatic, with models ranging from localized shear zones that are deep extensions of individual crustal faults to broad zones of diffuse, distributed shear with widths of hundreds of kilometers. Using seismic phases that convert from shear to compressional motion (Sp) at the base of the lithosphere beneath California, we find evidence for strike-slip deformation in the deepest mantle lithosphere beneath the central San Andreas fault that occurs over a horizontal width of 50 km or less. This study is based on over 135,000 Sp receiver functions from 730 seismic stations, including the Northern and Southern California Seismic Networks and the NSF EarthScope Transportable and Flexible Arrays. Individual Sp receiver functions were calculated using an extended-time multi-taper method and were migrated and stacked according to their three-dimensional conversion point locations using a model for crust (Lowry and Pérez-Gussinyé, 2011) and mantle (Obrebski et al., 2010 and 2011) velocity structure beneath each station and a spline-function representation of the Sp Fresnel zone. Sp conversion points at lithosphere-asthenosphere boundary depths are very dense on both sides of the San Andreas fault, and we interpreted the Sp common conversion point stack only at those nodes with information from more than 300 receiver functions. To the east of the plate boundary, a strong coherent Sp phase, indicative of a decrease in shear-wave velocity with depth, is present in the depth range where tomographic studies image the transition from high velocity lithosphere to low velocity asthenosphere. This phase, interpreted as the seismological lithosphere-asthenosphere boundary, has systematically lower amplitudes on the western side of the plate boundary, indicating that the drop in shear velocity from lithosphere to asthenosphere is either smaller or is distributed over a larger

  4. Entropy-Based Bagging for Fault Prediction of Transformers Using Oil-Dissolved Gas Data

    Directory of Open Access Journals (Sweden)

    Weigen Chen

    2011-08-01

    Full Text Available The development of the smart grid has resulted in new requirements for fault prediction of power transformers. This paper presents an entropy-based Bagging (E-Bagging method for prediction of characteristic parameters related to power transformers faults. A parameter of comprehensive information entropy of sample data is brought forward to improve the resampling process of the E-Bagging method. The generalization ability of the E-Bagging is enhanced significantly by the comprehensive information entropy. A total of sets of 1200 oil-dissolved gas data of transformers are used as examples of fault prediction. The comparisons between the E-Bagging and the traditional Bagging and individual prediction approaches are presented. The results show that the E-Bagging possesses higher accuracy and greater stability of prediction than the traditional Bagging and individual prediction approaches.

  5. The influence of transformers, induction motors and fault resistance regarding propagation voltage sags

    Directory of Open Access Journals (Sweden)

    Jairo Blanco

    2011-07-01

    Full Text Available This article presents an analysis of voltage sag propagation. The ATPDraw tool was selected for simulating the IEEE 34 node test feeder. It takes into account both voltage sags caused by electrical fault network, as well as voltage sag propagation characteristics caused by induction motor starting and transformer energising. The analysis was aimed at assessing the influence of transformer winding connections, the impedance of these transformers, lines and cables, summarising the effects on disturbance magnitude and phase. The study shows that the influence of an induction motor on voltage sag propagation results in increased voltage sag severity. Voltage sags caused by induction motor starting and transformer energising have no zero-sequence component, so they are only affected by type 3 transformers. The influence of fault resistance on voltage sag magnitude and phase characteristics is examined and some aspects of interest in characterising these electromagnetic disturbances is identified.

  6. How does the 2010 El Mayor - Cucapah Earthquake Rupture Connect to the Southern California Plate Boundary Fault System

    Science.gov (United States)

    Donnellan, A.; Ben-Zion, Y.; Arrowsmith, R.

    2016-12-01

    The Pacific - North American plate boundary in southern California is marked by several major strike slip faults. The 2010 M7.2 El Mayor - Cucapah earthquake ruptured 120 km of upper crust in Baja California to the US-Mexico border. The earthquake triggered slip along an extensive network of faults in the Salton Trough from the Mexican border to the southern end of the San Andreas fault. Earthquakes >M5 were triggered in the gap between the Laguna Salada and Elsinore faults at Ocotillo and on the Coyote Creek segment of the San Jacinto fault 20 km northwest of Borrego Springs. UAVSAR observations, collected since October of 2009, measure slip associated with the M5.7 Ocotillo aftershock with deformation continuing into 2014. The Elsinore fault has been remarkably quiet, however, with only M5.0 and M5.2 earthquakes occurring on the Coyote Mountains segment of the fault in 1940 and 1968 respectively. In contrast, the Imperial Valley has been quite active historically with numerous moderate events occurring since 1935. Moderate event activity is increasing along the San Jacinto fault zone (SJFZ), especially the trifurcation area, where 6 of 12 historic earthquakes in this 20 km long fault zone have occurred since 2000. However, no recent deformation has been detected using UAVSAR measurements in this area, including the recent M5.2 June 2016 Borrego earthquake. Does the El Mayor - Cucapah rupture connect to and transfer stress primarily to a single southern California fault or several? What is its role relative to the background plate motion? UAVSAR observations indicate that the southward extension of the Elsinore fault has recently experienced the most localized deformation. Seismicity suggests that the San Jacinto fault is more active than neighboring major faults, and geologic evidence suggests that the Southern San Andreas fault has been the major plate boundary fault in southern California. Topographic data with 3-4 cm resolution using structure from motion from

  7. Faults

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  8. Induced Voltages Ratio-Based Algorithm for Fault Detection, and Faulted Phase and Winding Identification of a Three-Winding Power Transformer

    Directory of Open Access Journals (Sweden)

    Byung Eun Lee

    2014-09-01

    Full Text Available This paper proposes an algorithm for fault detection, faulted phase and winding identification of a three-winding power transformer based on the induced voltages in the electrical power system. The ratio of the induced voltages of the primary-secondary, primary-tertiary and secondary-tertiary windings is the same as the corresponding turns ratio during normal operating conditions, magnetic inrush, and over-excitation. It differs from the turns ratio during an internal fault. For a single phase and a three-phase power transformer with wye-connected windings, the induced voltages of each pair of windings are estimated. For a three-phase power transformer with delta-connected windings, the induced voltage differences are estimated to use the line currents, because the delta winding currents are practically unavailable. Six detectors are suggested for fault detection. An additional three detectors and a rule for faulted phase and winding identification are presented as well. The proposed algorithm can not only detect an internal fault, but also identify the faulted phase and winding of a three-winding power transformer. The various test results with Electromagnetic Transients Program (EMTP-generated data show that the proposed algorithm successfully discriminates internal faults from normal operating conditions including magnetic inrush and over-excitation. This paper concludes by implementing the algorithm into a prototype relay based on a digital signal processor.

  9. Scaling Relations for the Thermal Structure of Segmented Oceanic Transform Faults

    Science.gov (United States)

    Wolfson-Schwehr, M.; Boettcher, M. S.; Behn, M. D.

    2015-12-01

    Mid-ocean ridge-transform faults (RTFs) are a natural laboratory for studying strike-slip earthquake behavior due to their relatively simple geometry, well-constrained slip rates, and quasi-periodic seismic cycles. However, deficiencies in our understanding of the limited size of the largest RTF earthquakes are due, in part, to not considering the effect of short intra-transform spreading centers (ITSCs) on fault thermal structure. We use COMSOL Multiphysics to run a series of 3D finite element simulations of segmented RTFs with visco-plastic rheology. The models test a range of RTF segment lengths (L = 10-150 km), ITSC offset lengths (O = 1-30 km), and spreading rates (V = 2-14 cm/yr). The lithosphere and upper mantle are approximated as steady-state, incompressible flow. Coulomb failure incorporates brittle processes in the lithosphere, and a temperature-dependent flow law for dislocation creep of olivine activates ductile deformation in the mantle. ITSC offsets as small as 2 km affect the thermal structure underlying many segmented RTFs, reducing the area above the 600˚C isotherm, A600, and thus the size of the largest expected earthquakes, Mc. We develop a scaling relation for the critical ITSC offset length, OC, which significantly reduces the thermal affect of adjacent fault segments of length L1 and L2. OC is defined as the ITSC offset that results in an area loss ratio of R = (Aunbroken - Acombined)/Aunbroken - Adecoupled) = 63%, where Aunbroken = C600(L1+L2)1.5V-0.6 is A600 for an RTF of length L1 + L2; Adecoupled = C600(L11.5+L21.5)V-0.6 is the combined A600 of RTFs of lengths L1 and L2, respectively; and Acombined = Aunbroken exp(-O/ OC) + Adecoupled (1-exp(-O/ OC)). C600 is a constant. We use OC and kinematic fault parameters (L1, L2, O, and V) to develop a scaling relation for the approximate seismogenic area, Aseg, for each segment of a RTF system composed of two fault segments. Finally, we estimate the size of Mc on a fault segment based on Aseg. We

  10. A Fault Feature Extraction Method for Rolling Bearing Based on Pulse Adaptive Time-Frequency Transform

    Directory of Open Access Journals (Sweden)

    Jinbao Yao

    2016-01-01

    Full Text Available Shock pulse method is a widely used technique for condition monitoring of rolling bearing. However, it may cause erroneous diagnosis in the presence of strong background noise or other shock sources. Aiming at overcoming the shortcoming, a pulse adaptive time-frequency transform method is proposed to extract the fault features of the damaged rolling bearing. The method arranges the rolling bearing shock pulses extracted by shock pulse method in the order of time and takes the reciprocal of the time interval between the pulse at any moment and the other pulse as all instantaneous frequency components in the moment. And then it visually displays the changing rule of each instantaneous frequency after plane transformation of the instantaneous frequency components, realizes the time-frequency transform of shock pulse sequence through time-frequency domain amplitude relevancy processing, and highlights the fault feature frequencies by effective instantaneous frequency extraction, so as to extract the fault features of the damaged rolling bearing. The results of simulation and application show that the proposed method can suppress the noises well, highlight the fault feature frequencies, and avoid erroneous diagnosis, so it is an effective fault feature extraction method for the rolling bearing with high time-frequency resolution.

  11. Power transformer fault diagnosis model based on rough set theory with fuzzy representation

    Institute of Scientific and Technical Information of China (English)

    Li Minghua; Dong Ming; Yan Zhang

    2007-01-01

    Objective Due to the incompleteness and complexity of fault diagnosis for power transformers, a comprehensive rough-fuzzy scheme for solving fault diagnosis problems is presented. Fuzzy set theory is used both for representation of incipient faults' indications and producing a fuzzy granulation of the feature space. Rough set theory is used to obtain dependency rules that model indicative regions in the granulated feature space. The fuzzy membership functions corresponding to the indicative regions, modelled by rules, are stored as cases. Results Diagnostic conclusions are made using a similarity measure based on these membership functions. Each case involves only a reduced number of relevant features making this scheme suitable for fault diagnosis. Conclusion Superiority of this method in terms of classification accuracy and case generation is demonstrated.

  12. Recurrence Behaviors of Earthquakes along the Kefallinia Transform Fault, Ionian Sea, Greece

    Institute of Scientific and Technical Information of China (English)

    Qi Cheng; Athanassios Ganas; Huang Fuqiong; Chen Yong; George Drakato

    2007-01-01

    We examined the whole strong earthquake recurrence behaviors of two fault zones along the Kefallinia Transform, Ionian Sea, Greece, using seismological data and statistical methods.Our data include 29 events with M > 5.5 for the period 1636 ~ 2003. We found different recurrence behaviors for the Kefallinia Fault Zone (clustering and time-predictable recurrence behaviors) and the Lefkada Fault Zone (near random and non-slip-predictable or non-timepredictable recurrence nature). The different modes may be attributed to: (a) segment interaction along-strike (Kefallinia) by static triggering and (b) the influence of fault systems to the north and east on the recurrence on Lefkada. Within the active periods, earthquake recurrence intervals are distributed in a more dispersed fashion, and can be fitted well by a Weibull distribution. In contrast, the distribution of the quiet periods is relatively less dispersed and difficult to describe by suitable probability functions.

  13. Detection and classification of winding faults in windmill generators using Wavelet Transform and ANN

    Energy Technology Data Exchange (ETDEWEB)

    Gketsis, Zacharias E.; Zervakis, Michalis E.; Stavrakakis, George [Department of Electronics and Computer Engineering, Technical University of Crete, Chania 73100 (Greece)

    2009-11-15

    This paper exploits the Wavelet Transform (WT) analysis along with Artificial Neural Networks (ANN) for the diagnosis of electrical machines winding faults. A novel application is presented exploring the problem of automatically identifying short circuits of windings, which often appear during machine manufacturing and operation. Such faults are usually resulting from electrodynamics forces generated during the flow of large short circuit currents, as well as forces occurring when the machines are transported. The early detection and classification of winding failures is of particular importance, as these kinds of defects can lead to winding damage due to overheating, imbalance, etc. Application results and investigations of windmill generator winding turn-to-turn faults between adjacent winding wires are presented. The ANN approach is proven effective in detecting and classifying faults based on WT features extracted from high frequency measurements of the admittance, current, or voltage responses. (author)

  14. Fault Diagnosis in Transformer Based on Weighted Degree of Grey Slope Incidence of Optimized Entropy

    Directory of Open Access Journals (Sweden)

    Zhang Anping

    2016-01-01

    Full Text Available Dissolved gas analysis (DGA is an important method to find the hidden or incipient insulation faults of oil-immersed power transformer. However, code deficiency exists in the gas ratio methods specified by the IEC standard and complexity of fault diagnosis for power transformer. Hence a new model based on optimized weighted degree of grey slope incidence was put forward. Firstly, the entropy weight is used to determine objective weight of indices; then the model fault types are obtained by weighted degree of grey slope incidence. The combination of entropy weight with grey slope incidence analysis can fully utilize over all information of DGA and give full play to the superiority of grey slope incidence, which overcomes shortcomings of original grey slope incidence analysis. The experimental results also demonstrate that the improved method has higher accuracy compared with three-ratio method and general grey slope incidence analysis method. The diagnosis accuracy is 92.8%.

  15. EXPERIMENTAL INVESTIGATION FOR FAULT DI AGNOSIS BASED ON FFT AND WAVELET TRANSFORM

    Directory of Open Access Journals (Sweden)

    MIHAIL PRICOP

    2016-06-01

    Full Text Available Belts are components of the mechanical systems of rotation commonly used for mechanical power transmission and changes in rotational speeds in the shafts. Various failures of the drive belts (foot shear, tooth wear, hollowed teeth, back cracks are common in rotating machines and can cause economic losses. To increase efficiency, reliability and safety of the machines the use of new fault diagnosis techniques of belts, identification and classification is required. In this paper Fast Fourier Transform (FFT and Wavelet transform complementary methods are used for fault monitoring of drive belts, analyzing in this way the limitations and advantages of using these methods. Experimental investigations for the fault diagnosis of drive belts are made using experimental platform and Bruel & Kjaer equipment for measuring vibration and PULSE and MATLAB software for recorded signal processing. The results were analyzed and presented.

  16. Intelligent Fault Diagnosis in Power Transformer with Using Dissolved Gas Analysis in different Standards by Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Rahmat Houshmand

    2007-09-01

    Full Text Available The power electric transformer fault diagnosis is based on dissolved gas-in-oil analysis (DGA. the conventional fault diagnosis methods, i.e. the ratio methods (Rogers, Dornenburg and IEC and the key gas method, have limitations such as the “no decision” problem. Various artificial intelligence techniques may help solve the problems and present a better solution. In this paper present a fuzzy systems to fault diagnosis in power electric transformer by dissolved we gas analysis.

  17. The October 28, 2012 Mw 7.8 Haida Gwaii underthrusting earthquake and tsunami: Slip partitioning along the Queen Charlotte Fault transpressional plate boundary

    Science.gov (United States)

    Lay, Thorne; Ye, Lingling; Kanamori, Hiroo; Yamazaki, Yoshiki; Cheung, Kwok Fai; Kwong, Kevin; Koper, Keith D.

    2013-08-01

    The Pacific/North American plate boundary is undergoing predominantly right-lateral strike-slip motion along the Queen Charlotte and Fairweather transform faults. The Queen Charlotte Fault (QCF) hosted the largest historical earthquake in Canada, the 1949 MS 8.1 strike-slip earthquake, which ruptured from offshore northern Haida Gwaii several hundred kilometers northwestward. On January 5, 2013 an Mw 7.5 strike-slip faulting event occurred near the northern end of the 1949 rupture zone. Along central and southern Haida Gwaii the relative plate motion has ∼20% oblique convergence across the left-stepping plate boundary. There had been uncertainty in how the compressional component of plate motion is accommodated. The October 28, 2012 Mw 7.8 Haida Gwaii earthquake involved slightly (∼20°) oblique thrust faulting on a shallow (∼18.5°) northeast-dipping fault plane with strike (∼320°) parallel to the QCF, consistent with prior inferences of Pacific Plate underthrusting beneath Haida Gwaii. The rupture extended to shallow depth offshore of Moresby Island beneath a 25-30 km wide terrace of sediments that has accumulated in a wedge seaward of the QCF. The shallow thrusting caused seafloor uplift that generated substantial localized tsunami run-up and a modest far-field tsunami that spread across the northern Pacific, prompting a tsunami warning, beach closure, and coastal evacuation in Hawaii, although ultimately tide gauges showed less than 0.8 m of water level increase. The mainshock rupture appears to have spread with a ∼2.3 km/s rupture velocity over a length of ∼150 km, with slip averaging 3.3 m concentrated beneath the sedimentary wedge. The event was followed by a substantial aftershock sequence, in which almost all of the larger events involve distributed intraplate normal faulting extending ∼50 km oceanward from the QCF. The highly oblique slip partitioning in southern Haida Gwaii is distinctive in that the local plate boundary-parallel motion on

  18. Quaternary tectonic activity in NW Jordan: Insights for a new model of transpression-transtension along the southern Dead Sea Transform Fault

    Science.gov (United States)

    Al-Awabdeh, M.; Pérez-Peña, J. V.; Azañón, J. M.; Booth-Rea, G.; Abed, A.; Atallah, M.; Galve, J. P.

    2016-12-01

    The Dead Sea Transform Fault (DSTF) constitutes the transform plate boundary between the African and Arabian plates. The southern part of this fault has been traditionally divided into two main segments, the Wadi Araba Fault (WAF) and the Jordan Valley Fault (JVF), connected through the Dead Sea continental pull-apart basin. Active tectonic studies in NW Jordan have traditionally focused on these DSTF structures and have neglected other prominent structures in the region, such as the Amman Hallabat Structure (AHS) and Shueib Structure (SHS) fault systems, which have been considered inactive since the Cretaceous. However, some recent studies have suggested a possible local reactivation of the southern parts of these structures. In this work, we carried out a detailed geological study of the NE Dead Sea Basin to analyze the Quaternary activity of the AHS and SHS based on field observations and structural analyses. Our findings have revealed that the AHS and SHS structures present clear Quaternary activity and accommodate a small part of the deformation of the southern DSTF. In the Quaternary, the southwestern part of the AHS has acted as the northernmost continuation of the WAF, whereas the SHS has acted as a transfer fault associated with NW-SE normal faults with low to moderate throws (meters to decameters) that connect this structure to the JVF. These NW-SE normal faults constitute the northeastern border of the Dead Sea depression (Jericho Valley). They produce a topographic front and separate the sediments of the Jordan Valley in the hanging wall from the Mesozoic sedimentary sequence located in the footwall.

  19. Grain Boundary Engineering of a Low Stacking Fault Energy Ni-based Superalloy

    Science.gov (United States)

    McCarley, Joshua; Helmink, Randolph; Goetz, Robert; Tin, Sammy

    2017-04-01

    The effects of thermo-mechanical processing parameters on the resulting microstructure of an experimental Nickel-based superalloy containing 24 wt pct Co were investigated. Hot compression tests were performed at temperatures ranging from 1293 K to 1373 K (1020 to 1100 °C) and strain rates ranging from 0.0005 to 0.1/s. The mechanically deformed samples were also subject to annealing treatments at sub-solvus 1388 K (1115 °C) and super-solvus 1413 K (1140 °C) temperatures. This investigation sought to quantify and subsequently understand the behavior and evolution of both the grain boundary structure and length fraction of Σ3 twin boundaries in the low stacking fault energy superalloy. Over the range of deformation parameters investigated, the corresponding deformation mechanism map revealed that dynamic recrystallization or dynamic recovery was dominant. These conditions largely promoted post-deformation grain refinement and the formation of annealing twins following annealing. Samples deformed at strain rates of 0.0005 and 0.001/s at 1333 K and 1373 K (1060 °C and 1100 °C) exhibited extensive grain boundary sliding/rotation associated with superplastic flow. Upon annealing, deformation conditions that resulted predominately in superplastic flow were found to provide negligible enhancement of twin boundaries and produced little to no post-deformation grain refinement.

  20. Grain Boundary Engineering of a Low Stacking Fault Energy Ni-based Superalloy

    Science.gov (United States)

    McCarley, Joshua; Helmink, Randolph; Goetz, Robert; Tin, Sammy

    2017-02-01

    The effects of thermo-mechanical processing parameters on the resulting microstructure of an experimental Nickel-based superalloy containing 24 wt pct Co were investigated. Hot compression tests were performed at temperatures ranging from 1293 K to 1373 K (1020 to 1100 °C) and strain rates ranging from 0.0005 to 0.1/s. The mechanically deformed samples were also subject to annealing treatments at sub-solvus 1388 K (1115 °C) and super-solvus 1413 K (1140 °C) temperatures. This investigation sought to quantify and subsequently understand the behavior and evolution of both the grain boundary structure and length fraction of Σ3 twin boundaries in the low stacking fault energy superalloy. Over the range of deformation parameters investigated, the corresponding deformation mechanism map revealed that dynamic recrystallization or dynamic recovery was dominant. These conditions largely promoted post-deformation grain refinement and the formation of annealing twins following annealing. Samples deformed at strain rates of 0.0005 and 0.001/s at 1333 K and 1373 K (1060 °C and 1100 °C) exhibited extensive grain boundary sliding/rotation associated with superplastic flow. Upon annealing, deformation conditions that resulted predominately in superplastic flow were found to provide negligible enhancement of twin boundaries and produced little to no post-deformation grain refinement.

  1. Study on relationship between deep and shallow structures along north boundary fault of Yanqing-Fanshan basin

    Institute of Scientific and Technical Information of China (English)

    于贵华; 徐锡伟; 朱艾澜; 马文涛; 刁桂苓; 张四昌; 张先康; 刘保金; 孙振国

    2004-01-01

    Based on the results of surface geology, shallow and deep seismic survey, features of micro-earthquake activity along the north boundary fault of Yanqing-Fanshan sub-basin and their relationship with the surface active faults and the deep-seated crustal structure are analyzed using the recordings from the high-resolution digital seismic network. The focal mechanism solutions of micro-earthquakes, whose locations are precisely determined by the seismic network, have confirmed the structural characteristics to be the rotational planar normal fault and demonstrated the surface traces of the north boundary fault of Yanqing-Fanshan sub-basin. By using the digital recordings of earthquakes with the high resolutions and analyzing the mechanism solutions, our study has revealed the relationship between the geological phenomena in the shallow and deep structures in Yanqing-Huailai basin and the transition features from the brittle to ductile deformation with the crustal depth.

  2. Slip history of the La Cruz fault: Development of a late Miocene transform in response to increased rift obliquity in the northern Gulf of California

    Science.gov (United States)

    Bennett, Scott E. K.; Oskin, Michael E.; Iriondo, Alexander; Kunk, Michael J.

    2016-12-01

    The Gulf of California rift has accommodated oblique divergence of the Pacific and North America plates in northwestern México since Miocene time. Due to its infancy, its rifted margins preserve a rare onshore record of early continental break-up processes and an opportunity to investigate the role of rift obliquity in strain localization. We map rift-related structures and syn-tectonic basins on southern Isla Tiburón, a proximal onshore exposure of the rifted North America margin. We integrate analysis and geochronology of syn-tectonic sedimentary basins and mapping of crosscutting relationships to characterize the style and timing of fault activity. On southern Isla Tiburón, an early phase of extension initiated between 19-17 Ma and 12.2 Ma. Subsequently, these normal faults and related basins were cut by the La Cruz strike-slip fault and buried by deposits of the La Cruz basin, an elongate, fault-controlled trough coextensive with the La Cruz fault. Crosscutting relationships show that the NW-striking La Cruz fault accrued 5 ± 2 km of dextral slip 8-4 Ma. The La Cruz fault and parallel Tiburón transform were kinematically linked to detachment faulting that accommodated latest Miocene to Pliocene oblique opening of the offshore Upper Tiburón pull-apart basin. The onset of strike-slip faulting on Isla Tiburón was synchronous with the 8-6 Ma onset of transform faulting and basin formation along > 1000 km of the reconstructed Pacific-North America plate boundary. This transition coincides with the commencement of a clockwise azimuthal shift in Pacific-North America relative plate motion that increased the obliquity of the Gulf of California rift and formed the Gulf of California shear zone. The record from the proto-Gulf of California illustrates how highly oblique rift geometries, where transform faults are kinematically linked to pull-apart basins, enhance the ability of continental lithosphere to rupture and, ultimately, hasten the formation of new oceanic

  3. Transforming incomplete fault tree to Ishikawa diagram as an alternative method for technology transfer

    Science.gov (United States)

    Batzias, Dimitris F.

    2012-12-01

    Fault Tree Analysis (FTA) can be used for technology transfer when the relevant problem (called 'top even' in FTA) is solved in a technology centre and the results are diffused to interested parties (usually Small Medium Enterprises - SMEs) that have not the proper equipment and the required know-how to solve the problem by their own. Nevertheless, there is a significant drawback in this procedure: the information usually provided by the SMEs to the technology centre, about production conditions and corresponding quality characteristics of the product, and (sometimes) the relevant expertise in the Knowledge Base of this centre may be inadequate to form a complete fault tree. Since such cases are quite frequent in practice, we have developed a methodology for transforming incomplete fault tree to Ishikawa diagram, which is more flexible and less strict in establishing causal chains, because it uses a surface phenomenological level with a limited number of categories of faults. On the other hand, such an Ishikawa diagram can be extended to simulate a fault tree as relevant knowledge increases. An implementation of this transformation, referring to anodization of aluminium, is presented.

  4. Distinctive Features of Faults for Use in Power Transformer Differential Protection

    Directory of Open Access Journals (Sweden)

    Glazyrin V.E.

    2017-04-01

    Full Text Available The aim of the work is to study the change in instantaneous values of the differential current in power transformer differential protection circuits under conditions of magnetizing inrush when the unloaded transformer is energized and under conditions of a fault within the protection zone. Saturation of measuring current transformers during the transient process leads to distortion of signals in their secondary windings, which can cause a long delay in the disconnection of the protected object and the development of an accident in the power system if traditional protective algorithms are used. Taking into account the peculiarities of the change in the instantaneous values of the differential current while developing the protection algorithm makes it possible to recognize faults with maximum speed before the moment of the first saturation of electromagnetic current transformers and thus avoid a delay in the operation of the protection. For quick and correct recognition of a fault within the protection zone authors proposed to monitor the maximum value of the derivative of the differential current and the duration of its monotonous change from the moment of the onset of the transient process. This is because the monitored parameters in the emergency and normal operation of the power transformer can vary significantly. Application of traditional protection algorithms together with proposed methods allows increasing the speed of differential protection response in different operation modes of the power system. Mathematical simulation has been used to study the magnetizing inrush and short circuits within the protection zone.

  5. Active faulting and transpression tectonics along the plate boundary in North Africa

    Directory of Open Access Journals (Sweden)

    Mustapha Meghraoui

    2013-01-01

    Full Text Available We present a synthesis of the active tectonics of the northern Atlas Mountains, and suggest a kinematic model of transpression and block rotation that illustrates the mechanics of this section of the Africa–Eurasia plate boundary. Neotectonic structures and significant shallow seismicity (with Mw >5.0 indicate that coeval E-W-trending, right-lateral faulting and NE-SW, thrust-related folding result from oblique convergence at the plate boundary, which forms a transpressional system. The strain distribution obtained from fault–fold structures and P axes of focal mechanism solutions, and the geodetic (NUVEL-1 and GPS convergence show that the shortening and convergence directions are not coaxial. The transpressional strain is partitioned along the strike and the quantitative description of the displacement field yields a compression-to-transcurrence ratio varying from 33% near Gibraltar, to 50% along the Tunisian Atlas. Shortening directions oriented NNE and NNW for the Pliocene and Quaternary, respectively, and the S shape of the Quaternary anticline axes, are in agreement with the 2.24˚/Myr to 3.9˚/Myr modeled clockwise rotation of the small tectonic blocks and with the paleomagnetic data. The convergence between Africa and Eurasia is absorbed along the Atlas Mountains at the upper crustal level, by means of thrusting above decollement systems, which are controlled by subdued transcurrent faults. The Tell Atlas of northwest Algeria, which has experienced numerous large earthquakes with respect to the other regions, is interpreted as a restraining bend that localizes the strain distribution along the plate boundary.

  6. Automatic fault feature extraction of mechanical anomaly on induction motor bearing using ensemble super-wavelet transform

    Science.gov (United States)

    He, Wangpeng; Zi, Yanyang; Chen, Binqiang; Wu, Feng; He, Zhengjia

    2015-03-01

    Mechanical anomaly is a major failure type of induction motor. It is of great value to detect the resulting fault feature automatically. In this paper, an ensemble super-wavelet transform (ESW) is proposed for investigating vibration features of motor bearing faults. The ESW is put forward based on the combination of tunable Q-factor wavelet transform (TQWT) and Hilbert transform such that fault feature adaptability is enabled. Within ESW, a parametric optimization is performed on the measured signal to obtain a quality TQWT basis that best demonstrate the hidden fault feature. TQWT is introduced as it provides a vast wavelet dictionary with time-frequency localization ability. The parametric optimization is guided according to the maximization of fault feature ratio, which is a new quantitative measure of periodic fault signatures. The fault feature ratio is derived from the digital Hilbert demodulation analysis with an insightful quantitative interpretation. The output of ESW on the measured signal is a selected wavelet scale with indicated fault features. It is verified via numerical simulations that ESW can match the oscillatory behavior of signals without artificially specified. The proposed method is applied to two engineering cases, signals of which were collected from wind turbine and steel temper mill, to verify its effectiveness. The processed results demonstrate that the proposed method is more effective in extracting weak fault features of induction motor bearings compared with Fourier transform, direct Hilbert envelope spectrum, different wavelet transforms and spectral kurtosis.

  7. Feature Extraction Using Discrete Wavelet Transform for Gear Fault Diagnosis of Wind Turbine Gearbox

    Directory of Open Access Journals (Sweden)

    Rusmir Bajric

    2016-01-01

    Full Text Available Vibration diagnosis is one of the most common techniques in condition evaluation of wind turbine equipped with gearbox. On the other side, gearbox is one of the key components of wind turbine drivetrain. Due to the stochastic operation of wind turbines, the gearbox shaft rotating speed changes with high percentage, which limits the application of traditional vibration signal processing techniques, such as fast Fourier transform. This paper investigates a new approach for wind turbine high speed shaft gear fault diagnosis using discrete wavelet transform and time synchronous averaging. First, the vibration signals are decomposed into a series of subbands signals with the use of a multiresolution analytical property of the discrete wavelet transform. Then, 22 condition indicators are extracted from the TSA signal, residual signal, and difference signal. Through the case study analysis, a new approach reveals the most relevant condition indicators based on vibrations that can be used for high speed shaft gear spalling fault diagnosis and their tracking abilities for fault degradation progression. It is also shown that the proposed approach enhances the gearbox fault diagnosis ability in wind turbines. The approach presented in this paper was programmed in Matlab environment using data acquired on a 2 MW wind turbine.

  8. Two-Dimensional Boundary Element Method Application for Surface Deformation Modeling around Lembang and Cimandiri Fault, West Java

    Science.gov (United States)

    Mahya, M. J.; Sanny, T. A.

    2017-04-01

    Lembang and Cimandiri fault are active faults in West Java that thread people near the faults with earthquake and surface deformation risk. To determine the deformation, GPS measurements around Lembang and Cimandiri fault was conducted then the data was processed to get the horizontal velocity at each GPS stations by Graduate Research of Earthquake and Active Tectonics (GREAT) Department of Geodesy and Geomatics Engineering Study Program, ITB. The purpose of this study is to model the displacement distribution as deformation parameter in the area along Lembang and Cimandiri fault using 2-dimensional boundary element method (BEM) using the horizontal velocity that has been corrected by the effect of Sunda plate horizontal movement as the input. The assumptions that used at the modeling stage are the deformation occurs in homogeneous and isotropic medium, and the stresses that acted on faults are in elastostatic condition. The results of modeling show that Lembang fault had left-lateral slip component and divided into two segments. A lineament oriented in southwest-northeast direction is observed near Tangkuban Perahu Mountain separating the eastern and the western segments of Lembang fault. The displacement pattern of Cimandiri fault shows that Cimandiri fault is divided into the eastern segment with right-lateral slip component and the western segment with left-lateral slip component separated by a northwest-southeast oriented lineament at the western part of Gede Pangrango Mountain. The displacement value between Lembang and Cimandiri fault is nearly zero indicating that Lembang and Cimandiri fault are not connected each other and this area is relatively safe for infrastructure development.

  9. Application of Wavelets Transform to Fault Detection in Rotorcraft UAV Sensor Failure

    Institute of Scientific and Technical Information of China (English)

    Jun-tong Qi; Jian-da Han

    2007-01-01

    This paper describes a novel wavelet-based approach to the detection of abrupt fault of Rotorcraft Unmanned Aerial Vehicle (RUAV) sensor system. By use of wavelet transforms that accurately localize the characteristics of a signal both in the time and frequency domains, the occurring instants of abnormal status of a sensor in the output signal can be identified by the multi-scale representation of the signal. Once the instants are detected, the distribution differences of the signal energy on all decomposed wavelet scales of the signal before and after the instants are used to claim and classify the sensor faults.

  10. Active faulting south of the Himalayan Front: Establishing a new plate boundary

    Science.gov (United States)

    Yeats, Robert S.; Thakur, V. C.

    2008-06-01

    New tectonic uplifts south of the Salt Range Thrust and Himalayan Front Thrust (HFT) represent an outward step of the plate boundary from the principal tectonic displacement zone into the Indo-Gangetic Plain. In Pakistan, the Lilla Anticline deforms fine-grained overbank deposits of the Jhelum River floodplain 15 km south of the Salt Range. The anticline is overpressured in Eocambrian non-marine strata. In northwest India south of Dehra Dun, the Piedmont Fault (PF) lies 15 km south of the HFT. Coalescing fans derived from the Himalaya form a piedmont (Old Piedmont Zone) 15-20 km wide east of the Yamuna River. This zone is uplifted as much as 15-20 m near the PF, and bedding is tilted 5-7° northeast. Holocene thermoluminescence-optically-stimulated luminescence dates for sediments in the Old Piedmont Zone suggest that the uplift rate might be as high as several mm/a. The Old Piedmont Zone is traced northwest 200 km and southeast another 200 km to the Nepal border. These structures, analogous to protothrusts in subduction zones, indicate that the Himalayan plate boundary is not a single structure but a series of structures across strike, including reactivated parts of the Main Boundary Thrust north of the range front, the HFT sensu stricto, and stepout structures on the Indo-Gangetic Plain. Displacement rates on all these structures must be added to determine the local India-Himalaya convergence rate.

  11. A novel algorithm for discrimination between inrush current and internal faults in power transformer differential protection based on discrete wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Eldin, A.A. Hossam; Refaey, M.A. [Electrical Engineering Department, Alexandria University, Alexandria (Egypt)

    2011-01-15

    This paper proposes a novel methodology for transformer differential protection, based on wave shape recognition of the discriminating criterion extracted of the instantaneous differential currents. Discrete wavelet transform has been applied to the differential currents due to internal fault and inrush currents. The diagnosis criterion is based on median absolute deviation (MAD) of wavelet coefficients over a specified frequency band. The proposed algorithm is examined using various simulated inrush and internal fault current cases on a power transformer that has been modeled using electromagnetic transients program EMTDC software. Results of evaluation study show that, proposed wavelet based differential protection scheme can discriminate internal faults from inrush currents. (author)

  12. Four-dimensional transform fault processes: progressive evolution of step-overs and bends

    Science.gov (United States)

    Wakabayashi, John; Hengesh, James V.; Sawyer, Thomas L.

    2004-11-01

    Many bends or step-overs along strike-slip faults may evolve by propagation of the strike-slip fault on one side of the structure and progressive shut-off of the strike-slip fault on the other side. In such a process, new transverse structures form, and the bend or step-over region migrates with respect to materials that were once affected by it. This process is the progressive asymmetric development of a strike-slip duplex. Consequences of this type of step-over evolution include: (1) the amount of structural relief in the restraining step-over or bend region is less than expected; (2) pull-apart basin deposits are left outside of the active basin; and (3) local tectonic inversion occurs that is not linked to regional plate boundary kinematic changes. This type of evolution of step-overs and bends may be common along the dextral San Andreas fault system of California; we present evidence at different scales for the evolution of bends and step-overs along this fault system. Examples of pull-apart basin deposits related to migrating releasing (right) bends or step-overs are the Plio-Pleistocene Merced Formation (tens of km along strike), the Pleistocene Olema Creek Formation (several km along strike) along the San Andreas fault in the San Francisco Bay area, and an inverted colluvial graben exposed in a paleoseismic trench across the Miller Creek fault (meters to tens of meters along strike) in the eastern San Francisco Bay area. Examples of migrating restraining bends or step-overs include the transfer of slip from the Calaveras to Hayward fault, and the Greenville to the Concord fault (ten km or more along strike), the offshore San Gregorio fold and thrust belt (40 km along strike), and the progressive transfer of slip from the eastern faults of the San Andreas system to the migrating Mendocino triple junction (over 150 km along strike). Similar 4D evolution may characterize the evolution of other regions in the world, including the Dead Sea pull-apart, the Gulf

  13. Fault diagnostics in power transformer model winding for different alpha values

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2015-09-01

    Full Text Available Transient overvoltages appearing at line terminal of power transformer HV windings can cause failure of winding insulation. The failure can be from winding to ground or between turns or sections of winding. In most of the cases, failure from winding to ground can be detected by changes in the wave shape of surge voltage appearing at line terminal. However, detection of insulation failure between turns may be difficult due to intricacies involved in identifications of faults. In this paper, simulation investigations carried out on a power transformer model winding for identifying faults between turns of winding has been reported. The power transformer HV winding has been represented by 8 sections, 16 sections and 24 sections. Neutral current waveform has been analyzed for same model winding represented by different number of sections. The values of α (‘α’ value is the square root of total ground capacitance to total series capacitance of winding considered for windings are 5, 10 and 20. Standard lightning impulse voltage (1.2/50 μs wave shape have been considered for analysis. Computer simulations have been carried out using software PSPICE version 10.0. Neutral current and frequency response analysis methods have been used for identification of faults within sections of transformer model winding.

  14. Discrimination of Inrush Currents from Faults Current in Power Transformers using Gravitational Search Algorithm (GSA

    Directory of Open Access Journals (Sweden)

    Mohamad Kazem Daryabari

    2011-01-01

    Full Text Available The magnetizing inrush current phenomenon is a large transient condition, which occurs when a transformer is energized. The inrush current magnitude may be as high as ten times of transformer rated current that causes mal-operation of protection systems. Indeed, the similarity between signatures of Inrush current and internal fault condition make this failure. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this project, an Artificial Neural Network (ANN which is trained by two different swarm based algorithms; Gravitational Search Algorithm (GSA and Particle Swarm Optimization (PSO have been used to discriminate inrush current from fault currents in power transformers. GSA works based on gravity laws and in opposite of other swarm based algorithms, particles have identity and PSO is based on behaviors of bird flocking. Proposed approach has two general stages, in first step, obtained data from simulation have been processed and applied to ANN, and then in step two, using training data considered ANN has been trained by GSA & PSO. Proposed method has been compared with one of the common training approach which is called Back Propagation (BP and Results show that proposed method is so quick and can do discrimination very accurate.

  15. Is the Troodos ophiolite (Cyprus) a complete, transform fault-bounded Neotethyan ridge segment?

    Science.gov (United States)

    Morris, Antony; Maffione, Marco

    2016-04-01

    We report new paleomagnetic data from the sheeted dike complex of the Troodos ophiolite (Cyprus) that indicate a hitherto unrecognized oceanic transform fault system marks its northern limit. The style, magnitude and scale of upper crustal fault block rotations in the northwestern Troodos region mirror those observed adjacent to the well-known Southern Troodos Transform Fault Zone along the southern edge of the ophiolite. A pattern of increasing clockwise rotation toward the north, coupled with consistent original dike strikes and inclined net rotation axes across this region, is compatible with distributed deformation adjacent to a dextrally-slipping transform system with a principal displacement zone just to the north of the exposed ophiolite. Combined with existing constraints on the spreading fabric, this implies segmentation of the Troodos ridge system on length scales of ~40 km, and suggests that a coherent strip of Neotethyan lithosphere, bounded by transforms and containing a complete ridge segment, has been uplifted to form the currently exposed Troodos ophiolite. Moreover, the inferred length scale of the ridge segment is consistent with formation at a slow-spreading rate during Tethyan seafloor spreading and with a supra-subduction zone environment, as indicated by geochemical constraints.

  16. Analysis and Simulation of Fault Characteristics of Power Switch Failures in Distribution Electronic Power Transformers

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2013-08-01

    Full Text Available This paper presents research on the voltage and current distortion in the input stage, isolation stage and output stage of Distribution Electronic Power transformer (D-EPT after the open-circuit and short-circuit faults of its power switches. In this paper, the operational principles and the control methods for input stage, isolation stage and output stage of D-EPT, which work as a cascaded H-bridge rectifier, DC-DC converter and inverter, respectively, are introduced. Based on conclusions derived from the performance analysis of D-EPT after the faults, this paper comes up with the effects from its topology design and control scheme on the current and voltage distortion. According to the EPT fault characteristics, since the waveforms of relevant components heavily depend on the location of the faulty switch, it is very easy to locate the exact position of the faulty switch. Finally, the fault characteristics peculiar to D-EPT are analyzed, and further discussed with simulation on the Saber platform, as well as a fault location diagnosis algorithm.

  17. Fast Fourier and discrete wavelet transforms applied to sensorless vector control induction motor for rotor bar faults diagnosis.

    Science.gov (United States)

    Talhaoui, Hicham; Menacer, Arezki; Kessal, Abdelhalim; Kechida, Ridha

    2014-09-01

    This paper presents new techniques to evaluate faults in case of broken rotor bars of induction motors. Procedures are applied with closed-loop control. Electrical and mechanical variables are treated using fast Fourier transform (FFT), and discrete wavelet transform (DWT) at start-up and steady state. The wavelet transform has proven to be an excellent mathematical tool for the detection of the faults particularly broken rotor bars type. As a performance, DWT can provide a local representation of the non-stationary current signals for the healthy machine and with fault. For sensorless control, a Luenberger observer is applied; the estimation rotor speed is analyzed; the effect of the faults in the speed pulsation is compensated; a quadratic current appears and used for fault detection.

  18. A Novel Association Rule Mining with IEC Ratio Based Dissolved Gas Analysis for Fault Diagnosis of Power Transformers

    Directory of Open Access Journals (Sweden)

    Ms. Kanika Shrivastava

    2012-06-01

    Full Text Available Dissolved gas Analysis (DGA is the most importantcomponent of finding fault in large oil filledtransformers. Early detection of incipient faults intransformers reduces costly unplanned outages. Themost sensitive and reliable technique for evaluatingthe core of transformer is dissolved gas analysis. Inthis paper we evaluate different transformercondition on different cases. This paper usesdissolved gas analysis to study the history ofdifferent transformers in service, from whichdissolved combustible gases (DCG in oil are usedas a diagnostic tool for evaluating the condition ofthe transformer. Oil quality and dissolved gassestests are comparatively used for this purpose. In thispaper we present a novel approach which is basedon association rule mining and IEC ratio method.By using data mining concept we can categorizefaults based on single and multiple associations andalso map the percentage of fault. This is an efficientapproach for fault diagnosis of power transformerswhere we can find the fault in all obviousconditions. We use java for programming andcomparative study.

  19. A fault location method using Lamb waves and discrete wavelet transform

    OpenAIRE

    Souza, Pablo Rodrigo de; Nobrega, Eurípedes Guilherme de Oliveira

    2012-01-01

    Non-destructive evaluation methods and signal process techniques are important steps in structural health monitoring systems to assess the structure integrity. This paper presents a method for fault location in aluminum beams based on time of flight of Lamb waves. The dynamic response signal captured from the structure was processed using the discrete wavelet transform. The information accuracy obtained from the processed signal depends on the correct choice of the mother wavelet. The best mo...

  20. [Application of optimized parameters SVM based on photoacoustic spectroscopy method in fault diagnosis of power transformer].

    Science.gov (United States)

    Zhang, Yu-xin; Cheng, Zhi-feng; Xu, Zheng-ping; Bai, Jing

    2015-01-01

    In order to solve the problems such as complex operation, consumption for the carrier gas and long test period in traditional power transformer fault diagnosis approach based on dissolved gas analysis (DGA), this paper proposes a new method which is detecting 5 types of characteristic gas content in transformer oil such as CH4, C2H2, C2H4, C2H6 and H2 based on photoacoustic Spectroscopy and C2H2/C2H4, CH4/H2, C2H4/C2H6 three-ratios data are calculated. The support vector machine model was constructed using cross validation method under five support vector machine functions and four kernel functions, heuristic algorithms were used in parameter optimization for penalty factor c and g, which to establish the best SVM model for the highest fault diagnosis accuracy and the fast computing speed. Particles swarm optimization and genetic algorithm two types of heuristic algorithms were comparative studied in this paper for accuracy and speed in optimization. The simulation result shows that SVM model composed of C-SVC, RBF kernel functions and genetic algorithm obtain 97. 5% accuracy in test sample set and 98. 333 3% accuracy in train sample set, and genetic algorithm was about two times faster than particles swarm optimization in computing speed. The methods described in this paper has many advantages such as simple operation, non-contact measurement, no consumption for the carrier gas, long test period, high stability and sensitivity, the result shows that the methods described in this paper can instead of the traditional transformer fault diagnosis by gas chromatography and meets the actual project needs in transformer fault diagnosis.

  1. Power Transformer Partial Discharge Fault Diagnosis Based on Multidimensional Feature Region

    Directory of Open Access Journals (Sweden)

    Rong Jia

    2016-01-01

    Full Text Available Effectively extracting power transformer partial discharge (PD signals feature is of great significance for monitoring power transformer insulation condition. However, there has been lack of practical and effective extraction methods. For this reason, this paper suggests a novel method for the PD signal feature extraction based on multidimensional feature region. Firstly, in order to better describe differences in each frequency band of fault signals, empirical mode decomposition (EMD and Hilbert-Huang transform (HHT band-pass filter wave for raw signal is carried out. And the component of raw signals on each frequency band can be obtained. Secondly, the sample entropy value and the energy value of each frequency band component are calculated. Using the difference of each frequency band energy and complexity, signals feature region is established by the multidimensional energy parameters and the multidimensional sample entropy parameters to describe PD signals multidimensional feature information. Finally, partial discharge faults are classified by sphere-structured support vector machines algorithm. The result indicates that this method is able to identify and classify different partial discharge faults.

  2. Current limiting behavior in three-phase transformer-type SFCLs using an iron core according to variety of fault

    Science.gov (United States)

    Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang

    To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.

  3. A New Method for Recognition of Arcing Faults in Transmission Lines using Wavelet Transform and Correlation Coefficient

    Directory of Open Access Journals (Sweden)

    Navid Ghaffarzadeh

    2013-03-01

    Full Text Available In this paper a novel method based on discrete wavelet transform and correlation coefficient is presented for distinguishing between arcing and permanent faults. The algorithm includes offline and online processing. In the offline, discrete wavelet transform is used to decompose typical faulted phase voltage waveforms during arcing faults. An index is then defined and computed. The index is based on the normalised energy of detail coefficients at resolution levels 1 to 14. The online processing consists of capturing the faulted phase voltage waveform using a 20 kHz sampling rate, and decomposing it by db4. Finally, arcing faults are distinguished from permanent faults based on correlation coefficient of the computed index of the pre-stored typical arcing faults and a recorded indistinct signal. The effectiveness of the approach has been tested for numerous arcing and permanent fault conditions on a transmission line using the Electromagnetic transient Program (EMTP software tool. The simulation results show the capability of the proposed method in distinguishing between arcing faults from permanent faults.

  4. A Novel Association Rule Mining with IEC Ratio Based Dissolved Gas Analysis for Fault Diagnosis of Power Transformers

    Directory of Open Access Journals (Sweden)

    Kanika Shrivastava

    2012-06-01

    Full Text Available Dissolved gas Analysis (DGA is the most important component of finding fault in large oil filled transformers. Early detection of incipient faults in transformers reduces costly unplanned outages. The most sensitive and reliable technique for evaluating the core of transformer is dissolved gas analysis. In this paper we evaluate different transformer condition on different cases. This paper uses dissolved gas analysis to study the history of different transformers in service, from which dissolved combustible gases (DCG in oil are used as a diagnostic tool for evaluating the condition of the transformer. Oil quality and dissolved gasses tests are comparatively used for this purpose. In this paper we present a novel approach which is based on association rule mining and IEC ratio method. By using data mining concept we can categorize faults based on single and multiple associations and also map the percentage of fault. This is an efficient approach for fault diagnosis of power transformers where we can find the fault in all obvious conditions. We use java for programming and comparative study.

  5. A Poisson-Fault Model for Testing Power Transformers in Service

    Directory of Open Access Journals (Sweden)

    Dengfu Zhao

    2014-01-01

    Full Text Available This paper presents a method for assessing the instant failure rate of a power transformer under different working conditions. The method can be applied to a dataset of a power transformer under periodic inspections and maintenance. We use a Poisson-fault model to describe failures of a power transformer. When investigating a Bayes estimate of the instant failure rate under the model, we find that complexities of a classical method and a Monte Carlo simulation are unacceptable. Through establishing a new filtered estimate of Poisson process observations, we propose a quick algorithm of the Bayes estimate of the instant failure rate. The proposed algorithm is tested by simulation datasets of a power transformer. For these datasets, the proposed estimators of parameters of the model have better performance than other estimators. The simulation results reveal the suggested algorithms are quickest among three candidates.

  6. Incipient fault diagnosis of power transformers using optical spectro-photometric technique

    Science.gov (United States)

    Hussain, K.; Karmakar, Subrata

    2015-06-01

    Power transformers are the vital equipment in the network of power generation, transmission and distribution. Mineral oil in oil-filled transformers plays very important role as far as electrical insulation for the winding and cooling of the transformer is concerned. As transformers are always under the influence of electrical and thermal stresses, incipient faults like partial discharge, sparking and arcing take place. As a result, mineral oil deteriorates there by premature failure of the transformer occurs causing huge losses in terms of revenue and assets. Therefore, the transformer health condition has to be monitored continuously. The Dissolved Gas Analysis (DGA) is being extensively used for this purpose, but it has some drawbacks like it needs carrier gas, regular instrument calibration, etc. To overcome these drawbacks, Ultraviolet (UV) -Visible and Fourier Transform Infrared (FTIR) Spectro-photometric techniques are used as diagnostic tools for investigating the degraded transformer oil affected by electrical, mechanical and thermal stresses. The technique has several advantages over the conventional DGA technique.

  7. Global rates of mantle serpentinization and H2 release at oceanic transform faults

    Science.gov (United States)

    Ruepke, Lars; Hasenclever, Joerg

    2017-04-01

    The cycling of seawater through the ocean floor is the dominant mechanism of biogeochemical exchange between the solid earth and the global ocean. Crustal fluid flow appears to be typically associated with major seafloor structures, and oceanic transform faults (OTF) are one of the most striking yet poorly understood features of the global mid-ocean ridge systems. Fracture zones and transform faults have long been hypothesized to be sites of substantial biogeochemical exchange between the solid Earth and the global ocean. This is particularly interesting with regard to the ocean biome. Deep ocean ecosystems constitute 60% of it but their role in global ocean biogeochemical cycles is much overlooked. There is growing evidence that life is supported by chemosynthesis at hydrothermal vents but also in the crust, and therefore this may be a more abundant process than previously thought. In this context, the serpentine forming interaction between seawater and cold lithospheric mantle rocks is particularly interesting as it is also a mechanism of abiotic hydrogen and methane formation. Interestingly, a quantitative global assessment of mantle serpentinization at oceanic transform faults in the context of the biogeochemical exchange between the seafloor and the global ocean is still largely missing. Here we present the results of a set of 3-D thermo-mechanical model calculations that investigate mantle serpentinization at OTFs for the entire range of globally observed slip rates and fault lengths. These visco-plastic models predict the OTF thermal structure and the location of crustal-scale brittle deformation, which is a prerequisite for mantle serpentinization to occur. The results of these simulations are integrated with information on the global distribution of OTF lengths and slip rates yielding global estimates on mantle serpentinization and associated H2 release. We find that OTFs are potentially sites of intense crustal fluid flow and are in terms of H2 release

  8. Sub-module Short Circuit Fault Diagnosis in Modular Multilevel Converter Based on Wavelet Transform and Adaptive Neuro Fuzzy Inference System

    DEFF Research Database (Denmark)

    Liu, Hui; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    for continuous operation and post-fault maintenance. In this article, a fault diagnosis technique is proposed for the short circuit fault in a modular multi-level converter sub-module using the wavelet transform and adaptive neuro fuzzy inference system. The fault features are extracted from output phase voltage...

  9. Incipient Stator Insulation Fault Detection of Permanent Magnet Synchronous Wind Generators Based on Hilbert–Huang Transformation

    DEFF Research Database (Denmark)

    Wang, Chao; Liu, Xiao; Chen, Zhe

    2014-01-01

    Incipient stator winding fault in permanent magnet synchronous wind generators (PMSWGs) is very difficult to be detected as the fault generated variations in terminal electrical parameters are very weak and chaotic. This paper simulates the incipient stator winding faults at different degree...... of insulation degradation of one turn in the winding of a PMSWG. Cosimulation method by combining finite element model and external circuits is used. Hilbert–Huang transformation is applied to detect the very early stage fault in interturn insulation by analyzing the stator current. Detection results show...

  10. Wavelet transform based on inner product in fault diagnosis of rotating machinery: A review

    Science.gov (United States)

    Chen, Jinglong; Li, Zipeng; Pan, Jun; Chen, Gaige; Zi, Yanyang; Yuan, Jing; Chen, Binqiang; He, Zhengjia

    2016-03-01

    As a significant role in industrial equipment, rotating machinery fault diagnosis (RMFD) always draws lots of attention for guaranteeing product quality and improving economic benefit. But non-stationary vibration signal with a large amount of noise on abnormal condition of weak fault or compound fault in many cases would lead to this task challenging. As one of the most powerful non-stationary signal processing techniques, wavelet transform (WT) has been extensively studied and widely applied in RMFD. Numerous publications about the study and applications of WT for RMFD have been presented to academic journals, technical reports and conference proceedings. Many previous publications admit that WT can be realized by means of inner product principle of signal and wavelet base. This paper verifies the essence on inner product operation of WT by simulation and field experiments. Then the development process of WT based on inner product is concluded and the applications of major developments in RMFD are also summarized. Finally, super wavelet transform as an important prospect of WT based on inner product are presented and discussed. It is expected that this paper can offer an in-depth and comprehensive references for researchers and help them with finding out further research topics.

  11. Late Quaternary sinistral slip rate along the Altyn Tagh fault and its structural transformation model

    Institute of Scientific and Technical Information of China (English)

    XU; Xiwei; P.; Tapponnier; J.; Van; Der; Woerd; F.; J.; Ryer

    2005-01-01

    Based on technical processing of high-resolution SPOT images and aerophotos,detailed mapping of offset landforms in combination with field examination and displacement measurement, and dating of offset geomorphic surfaces by using carbon fourteen (14C), cosmogenic nuclides (10Be+26Al) and thermoluminescence (TL) methods, the Holocene sinistral slip rates on different segments of the Altyn Tagh Fault (ATF) are obtained. The slip rates reach 17.5±2 mm/a on the central and western segments west of Aksay Town, 11±3.5 mm/a on the Subei-Shibaocheng segment, 4.8± 1.0 mm/a on the Sulehe segment and only 2.2± 0.2 mm/a on the Kuantanshan segment, an easternmost segment of the ATF. The sudden change points for loss of sinistral slip rates are located at the Subei, Shibaocheng and Shulehe triple junctions where NW-trending active thrust faults splay from the ATF and propagate southeastward. Slip vector analyses indicate that the loss of the sinistral slip rates from west to east across a triple junction has structurally transformed into local crustal shortening perpendicular to the active thrust faults and strong uplifting of the thrust sheets to form the NW-trending Danghe Nanshan,Daxueshan and Qilianshan Ranges. Therefore, the eastward extrusion of the northern Qinghai-Tibetan Plateau is limited and this is in accord with "the imbricated thrusting transformation-limited extrusion model".

  12. Support vector machine based decision for mechanical fault condition monitoring in induction motor using an advanced Hilbert-Park transform.

    Science.gov (United States)

    Ben Salem, Samira; Bacha, Khmais; Chaari, Abdelkader

    2012-09-01

    In this work we suggest an original fault signature based on an improved combination of Hilbert and Park transforms. Starting from this combination we can create two fault signatures: Hilbert modulus current space vector (HMCSV) and Hilbert phase current space vector (HPCSV). These two fault signatures are subsequently analysed using the classical fast Fourier transform (FFT). The effects of mechanical faults on the HMCSV and HPCSV spectrums are described, and the related frequencies are determined. The magnitudes of spectral components, relative to the studied faults (air-gap eccentricity and outer raceway ball bearing defect), are extracted in order to develop the input vector necessary for learning and testing the support vector machine with an aim of classifying automatically the various states of the induction motor.

  13. Gravity and Magnetic Survey of the Oaxaca-Juarez Terrane Boundary (Oaxaca Fault), Southern Mexico: Evidence for three Half Grabens

    Science.gov (United States)

    Campos-Enriquez, J. O.; Belmonte-Jimenez, S. I.; Ortega-Gutierrez, F.; Keppie-Moorhouse, J. D.; Martinez-Silva, J.; Martinez-Serrano, R.

    2007-05-01

    A geophysical survey of the Oaxaca Fault boundary between the Oaxaca (Oaxaquia) (Zapoteco) and Juarez (Cuicateco) terranes along the Etla and Zaachila valleys area, southern Mexico shows a series of NW-SE Bouguer and magnetic anomalies with stronger gradients towards the east. The basement from the Oaxaca terrane has a high density (2.8 gr/cm3 ) and magnetic susceptibility of up to 0.0051 cgs units, which contrast with the Juarez basement that has a lower density (2.67 gr/cm3) and a higher magnetic susceptibility (values ranging between 0.0025 to 0.0045 cgs units). The magnetic susceptibility is similar south of the Donaji fault. Interpretation of six combined gravity and magnetic NE-SW profiles perpendicular to the valleys indicates the presence of a composite depression comprising three N-S sub-basins with the Etla and Zachila sub-basins located at the northern and southern portions, respectively, separated by a third sub-basin relatively displaced westwards. They are bounded on the east by the steeply W-dipping Oaxaca master fault, and on the west by the gently E-dipping Huitzo-Zimatlan fault. Two interpretations are suggested for the southward continuation of the Oaxaca Fault: 1) it continues southwards at depth with the same strike. Together the Bouguer and total field magnetic anomalies suggest that the Oaxaca fault is continuous from Etla via Oaxaca City and Ocotlán de Morelos probably to Miahuatlán de Porfirio Díaz, and 2) it continues with the same strike but is displaced eastwards ~20 km along a sinistral transfer fault, which forms the northern boundary of the Zaachila sub-basin.

  14. The Garzon fault: active southwestern boundary of the Caribbean plate in Colombia

    Science.gov (United States)

    Chorowicz, J.; Chotin, P.; Guillande, R.

    1996-03-01

    We propose active right-lateral strike-slip motion on the Garzon fault zone of the Neiva basin, Colombia, based on the identification of two active right-stepping releasing bend basins along the fault using stereoscopic analysis of 1/250000 SPOT images. The Garzon fault connects the Bocono-Pamplona-Guaicaramo fault zones of Venezuela and Colombia with the Romeral, Dolores and Guayaquil faults of Colombia. Together these faults form a continuous, active right-lateral fault between accreted terranes in northwestern South America and a more stable South America plate. We infer 5-km right-lateral offset of the Garzon fault based on the width of the Algeciras releasing bend basin.

  15. Oceanic Transform Fault-Zone Geomorphology in the Gulf of California from High-Resolution Bathymetric Data

    Science.gov (United States)

    Hilley, G. E.; Aron, F.; Baden, C. W.; Castillo, C. M.; Johnstone, S. A.; Nevitt, J. M.; McHargue, T.; Paull, C. K.; Sare, R.; Shumaker, L.; Young, H.

    2015-12-01

    We use high-resolution, deep-water bathymetry to examine the structure of, and offset along, transform faults in the Gulf of California. These data provide detailed observations of fault-zone geomorphology of an active transform fault hosted in an area transitioning from continental to oceanic crust. Bathymetric data were collected by an autonomous underwater vehicle deployed by the Monterey Bay Aquarium Research Institute in 2012. Dense ocean-bottom point clouds allowed construction of an ~1-m-resolution digital terrain model, which provides comparable spatial resolution to early airborne laser swath mapping surveys. The data reveal a set of complex, multi-stranded fault zones, whose morphologies suggest a temporal migration of deformation between individual strands contained within an up to 1 km wide zone, similar to complex fault zones observed within continental crust in subaerial environments. Individual fault strands show restraining steps that create positive relief along the ocean floor in their vicinity. Although the depositional nature of these deep-water systems makes identification of offset features challenging, we found a series of offset fans along a fault strand with consistent right-lateral offsets of 17-21 m. These are likely multi-event offsets, given the length of the transform segments and magnitudes of historically recorded earthquakes in the region. The consistency of these multi-event offsets suggests that an external process predating the displacement of the fans, such as seismic shaking due to large earthquakes, may be responsible for the synchroneity of these features. Our study demonstrates that the fault-zone geomorphology of oceanic transform faults in the Gulf of California bears resemblance to that of terrestrial strike-slip faults hosted in continental crust, and that high-resolution, deep water bathymetry can provide information about the earthquake history of these environments.

  16. Dynamic triggering and earthquake swarms on East Pacific Rise transform faults

    Science.gov (United States)

    Cattania, Camilla; McGuire, Jeffrey J.; Collins, John A.

    2017-01-01

    While dynamic earthquake triggering has been reported in several continental settings, offshore observations are rare. Oceanic transform faults share properties with continental geothermal areas known for dynamic triggering: high geothermal gradients, high seismicity rates, and frequent swarms. We study dynamic triggering along the East Pacific Rise by analyzing 1 year of seismicity recorded by Ocean Bottom Seismographs. By comparing the response to teleseismic waves from global earthquakes, we find triggering to be most sensitive to changes in normal stress and to preferentially occur above 0.25 kPa. The clearest example of triggering occurs on the Quebrada and Gofar faults after the Mw8.0 Wenchuan earthquake. On Gofar, triggered seismicity occurs between the rupture areas of large earthquakes, within a zone characterized by aseismic slip, abundant microseismicity, frequent swarms, and low Vp. We infer that lithological properties inhibiting rupture propagation, such as high porosity and fluid content, also favor dynamic triggering.

  17. Investigations on Incipient Fault Diagnosis of Power Transformer Using Neural Networks and Adaptive Neurofuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Nandkumar Wagh

    2014-01-01

    Full Text Available Continuity of power supply is of utmost importance to the consumers and is only possible by coordination and reliable operation of power system components. Power transformer is such a prime equipment of the transmission and distribution system and needs to be continuously monitored for its well-being. Since ratio methods cannot provide correct diagnosis due to the borderline problems and the probability of existence of multiple faults, artificial intelligence could be the best approach. Dissolved gas analysis (DGA interpretation may provide an insight into the developing incipient faults and is adopted as the preliminary diagnosis tool. In the proposed work, a comparison of the diagnosis ability of backpropagation (BP, radial basis function (RBF neural network, and adaptive neurofuzzy inference system (ANFIS has been investigated and the diagnosis results in terms of error measure, accuracy, network training time, and number of iterations are presented.

  18. En echelon knolls in the Nosappu Fracture Zone, NW Pacific: A possible leaky transform fault zone

    Science.gov (United States)

    Ogawa, Y.; Hirano, N.; Shipboard Scientific Party Kr03-07, .

    2003-12-01

    During JAMSTEC R/V KAIREI cruise KR03-07, we mapped significant en echelon arrays of knolls and ridges on the NNW-trending Nosappu Fracture Zone between Hokkaido and Shatsky Rise, NW Pacific. This fracture zone has been known to be irregular, including a deep-sea channel, the Nakwe Channel, enigmatic for inside the wide oceanic plate. Considering the previously recognized magnetic lineament dislocation, the fracture zone has long (more than 150 km) left-lateral strike-slip component as a ridge-ridge transform fault zone between the Izanagi and Pacific plates during Early Cretaceous. Detail multi-narrowbeam mapping around 37 N latitude, 150 E longitude (covering 78 km x 137 km), indicated many small knolls and ridges that form en echelon arrangement. Some are boomerang, sock or E-letter in shape. The two dominant directions of ridges are recognized, one is parallel to the fracture zone and the other is in left-handed en echelon fashion. Besides these ridges, there are other types of ridges or conical knolls lower than 500 m in relief; one is a group of rather large knolls extending to NE, roughly perpendicular to the fracture zone direction, and the other is independent small knolls, summing up to five or six in number. Another expression of a depression zone was recognized with a moderate angle to the fracture zone in a crank fashion. This may correspond to the so-called _gNakwe Channel_h which has been wrongly mistaken. Such en echelon arrays are involved in a 50 km wide NNW-SSE zone, which is sharply demarcated by fault scarps. These characteristics in the fracture zone area and associated knolls suggest that this part of the Nosappu Fracture Zone might have developed in a fault interaction area which has a left-lateral component of leaky transform faulting close to the spreading ridge.

  19. Crustal structure of the Eurasia-Africa plate boundary across the Gloria Fault, North Atlantic Ocean

    Science.gov (United States)

    Batista, Luis; Hübscher, Christian; Terrinha, Pedro; Matias, Luis; Afilhado, Alexandra; Lüdmann, Thomas

    2017-05-01

    The oceanic crustal and uppermost lithospheric mantle structure across the Gloria Fault (GF) transcurrent plate boundary between Africa and Eurasia in the Northeast Atlantic is investigated based on seismic reflection, seismic refraction and wide-angle reflection data. This experiment used 18 ocean bottom stations along an N-S 150 km long traverse together with acquisition of a multichannel seismic reflection profile. Modeling of P and S seismic waves and gravimetric anomalies allowed estimation of P- and S-wave velocities, density, Poisson's ratio and discussion of a compositional model. A five-layer model is proposed in which layers 1-3 correspond to normal sediments through typical oceanic crust layers 2 and 3. Layer 5 yielded mantle velocities above 7.9 km s-1. Layer 4 with 4 km of thickness has Vp velocities between 7.1 and 7.4 km s-1 and is clearly separated from typical oceanic crust and mantle layers. Comparison with natural analogues and published lab measurements suggest that layer 4 can be a mix of lithologies that comply with the estimated P and S velocities and computed Poisson's ratio and densities, such as, olivine cumulates, peridotite, gabbro and hydrated mantle. We favour the tectonic process that produces secondary porosity from which results serpentinization due to sea water circulation in fractures. Structural and seismic stratigraphic interpretation of the reflection profile shows that Neogene to recent tectonic deformation on this segment of the plate boundary concentrated on the southern side of the GF, that is, the Africa plate.

  20. Boundary Issues and Transformation Possibilities in the HBSE Curriculum.

    Science.gov (United States)

    Levande, Diane I.

    1987-01-01

    "Add and stir" approaches to curriculum revision can result in contradictory and fragmented human behavior in the social environment (HBSE) content; therefore, transformative approaches are advocated. Curriculum transformation experiences described in the feminist literature are explored for applicability to social work. (Author/MH)

  1. Numerical Methods for the Analysis of Power Transformer Tank Deformation and Rupture Due to Internal Arcing Faults.

    Science.gov (United States)

    Yan, Chenguang; Hao, Zhiguo; Zhang, Song; Zhang, Baohui; Zheng, Tao

    2015-01-01

    Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers.

  2. Numerical Methods for the Analysis of Power Transformer Tank Deformation and Rupture Due to Internal Arcing Faults.

    Directory of Open Access Journals (Sweden)

    Chenguang Yan

    Full Text Available Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers.

  3. Comparison of the quench and fault current limiting characteristics of the flux-coupling type SFCL with single and three-phase transformer

    Science.gov (United States)

    Jung, Byung Ik; Cho, Yong Sun; Park, Hyoung Min; Chung, Dong Chul; Choi, Hyo Sang

    2013-01-01

    The South Korean power grid has a network structure for the flexible operation of the system. The continuously increasing power demand necessitated the increase of power facilities, which decreased the impedance in the power system. As a result, the size of the fault current in the event of a system fault increased. As this increased fault current size is threatening the breaking capacity of the circuit breaker, the main protective device, a solution to this problem is needed. The superconducting fault current limiter (SFCL) has been designed to address this problem. SFCL supports the stable operation of the circuit breaker through its excellent fault-current-limiting operation [1-5]. In this paper, the quench and fault current limiting characteristics of the flux-coupling-type SFCL with one three-phase transformer were compared with those of the same SFCL type but with three single-phase transformers. In the case of the three-phase transformers, both the superconducting elements of the fault and sound phases were quenched, whereas in the case of the single-phase transformer, only that of the fault phase was quenched. For the fault current limiting rate, both cases showed similar rates for the single line-to-ground fault, but for the three-wire earth fault, the fault current limiting rate of the single-phase transformer was over 90% whereas that of the three-phase transformer was about 60%. It appears that when the three-phase transformer was used, the limiting rate decreased because the fluxes by the fault current of each phase were linked in one core. When the power loads of the superconducting elements were compared by fault type, the initial (half-cycle) load was great when the single-phase transformer was applied, whereas for the three-phase transformer, its power load was slightly lower at the initial stage but became greater after the half fault cycle.

  4. Use of Fourier Transformation for Detection of Faults in Underground Power Cables

    Institute of Scientific and Technical Information of China (English)

    Abhishek Pandey; Nicolas H. Younan

    2011-01-01

    An analysis of underground power cables is performed using Fourier analysis with the objective of detecting fault and average life of the cables. Three types of cables are used in this experiment: a normal cable, a shorted cable, and a cable with holes. The impedance in each case is computed and Fourier transformation is applied so that the re- suiting impedance magnitude and impedance phase can be examined in the frequency domain. Various windowing tech- niques are applied to the experimental data to eliminate any interference. Fourier analysis is then applied to the imped- ance data calculated from both the sending end voltage and differential voltage. This analysis reveals differences in the frequency response of the three different types of a cable and can eventually be used as a measure for fault detection. Preliminary results reveal the differences in the frequency response. Accordingly, Fourier type methods can be effectively used as low cost and viable solutions to identify and detect faults in underground cables.

  5. Verification of Transformer Restricted Earth Fault Protection by using the Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    KRSTIVOJEVIC, J. P.

    2015-08-01

    Full Text Available The results of a comprehensive investigation of the influence of current transformer (CT saturation on restricted earth fault (REF protection during power transformer magnetization inrush are presented. Since the inrush current during switch-on of unloaded power transformer is stochastic, its values are obtained by: (i laboratory measurements and (ii calculations based on the input data obtained by the Monte Carlo (MC simulation. To make a detailed assessment of the current transformer performance the uncertain input data for the CT model were obtained by applying the MC method. In this way, different levels of remanent flux in CT core are taken into consideration. By the generated CT secondary currents, the algorithm for REF protection based on phase comparison in time domain is tested. On the basis of the obtained results, a method of adjustment of the triggering threshold in order to ensure safe operation during transients, and thereby improve the algorithm security, has been proposed. The obtained results indicate that power transformer REF protection would be enhanced by using the proposed adjustment of triggering threshold in the algorithm which is based on phase comparison in time domain.

  6. Identification of Magnetizing Inrush and Internal Short-Circuit Fault Current in V/x-Type Traction Transformer

    Directory of Open Access Journals (Sweden)

    Y. H. Li

    2013-01-01

    Full Text Available This paper deals with the fault diagnosis methodology for the V/x-type traction transformer in railway passenger-dedicated lines. A kind of the protection methodology to combine empirical mode decomposition (EMD, energy weight, and information entropy is proposed. This method can sensitively reflect the dynamic information changes of traction transformer differential current, so it can not only effectively identify internal short-circuit fault current from magnetizing inrush but also better identify fault current accompanied with magnetizing inrush. In this method, the differential current is decomposed by EMD and the energy weight of each intrinsic mode function (IMF is calculated, and the feature vector of the fault pattern recognition is obtained by constructing IMF energy entropy. The field-measured data illustrate that the new method not only has the advantages of high sensitivity, faster identification speed, and clear concept but also is available for the diagnosis of the complicated dynamic system.

  7. Adaptive Redundant Lifting Wavelet Transform Based on Fitting for Fault Feature Extraction of Roller Bearings

    Directory of Open Access Journals (Sweden)

    Huaqing Wang

    2012-03-01

    Full Text Available A least square method based on data fitting is proposed to construct a new lifting wavelet, together with the nonlinear idea and redundant algorithm, the adaptive redundant lifting transform based on fitting is firstly stated in this paper. By variable combination selections of basis function, sample number and dimension of basis function, a total of nine wavelets with different characteristics are constructed, which are respectively adopted to perform redundant lifting wavelet transforms on low-frequency approximate signals at each layer. Then the normalized lP norms of the new node-signal obtained through decomposition are calculated to adaptively determine the optimal wavelet for the decomposed approximate signal. Next, the original signal is taken for subsection power spectrum analysis to choose the node-signal for single branch reconstruction and demodulation. Experiment signals and engineering signals are respectively used to verify the above method and the results show that bearing faults can be diagnosed more effectively by the method presented here than by both spectrum analysis and demodulation analysis. Meanwhile, compared with the symmetrical wavelets constructed with Lagrange interpolation algorithm, the asymmetrical wavelets constructed based on data fitting are more suitable in feature extraction of fault signal of roller bearings.

  8. Improved probabilistic neural networks with self-adaptive strategies for transformer fault diagnosis problem

    Directory of Open Access Journals (Sweden)

    Jiao-Hong Yi

    2016-01-01

    Full Text Available Probabilistic neural network has successfully solved all kinds of engineering problems in various fields since it is proposed. In probabilistic neural network, Spread has great influence on its performance, and probabilistic neural network will generate bad prediction results if it is improperly selected. It is difficult to select the optimal manually. In this article, a variant of probabilistic neural network with self-adaptive strategy, called self-adaptive probabilistic neural network, is proposed. In self-adaptive probabilistic neural network, Spread can be self-adaptively adjusted and selected and then the best selected Spread is used to guide the self-adaptive probabilistic neural network train and test. In addition, two simplified strategies are incorporated into the proposed self-adaptive probabilistic neural network with the aim of further improving its performance and then two versions of simplified self-adaptive probabilistic neural network (simplified self-adaptive probabilistic neural networks 1 and 2 are proposed. The variants of self-adaptive probabilistic neural networks are further applied to solve the transformer fault diagnosis problem. By comparing them with basic probabilistic neural network, and the traditional back propagation, extreme learning machine, general regression neural network, and self-adaptive extreme learning machine, the results have experimentally proven that self-adaptive probabilistic neural networks have a more accurate prediction and better generalization performance when addressing the transformer fault diagnosis problem.

  9. The Alarcón Rise: detail mapping and preliminary results on the geometry, distribution and kinematics of faults and fissures on a ridge-transform system

    Science.gov (United States)

    Spelz, R. M.; Fletcher, J. M.; Nieves-Cardoso, C.; Santa Rosa-del Rio, M.; Caress, D. W.; Clague, D. A.; Paduan, J. B.; Martin, J. F.; Guardado-France, R.

    2012-12-01

    The Alarcón Rise, the northernmost segment of the East Pacific Rise before it enters the Gulf of California, is the oldest and perhaps most active spreading ridge-transform system along the oblique-divergent Pacific-North America plate boundary in the southern Gulf of California. Magnetic anomalies along the main ridge axis, which stretches for nearly 50 km long in a NE-SW (034o) direction, suggest that spreading with new oceanic crust was fully established ca. 2.5 Ma, and that its modern configuration as the main plate boundary initiated ca. 2 Ma (Umhoefer, P.J. et al., 2007 Basin Research). High resolution (1m lateral/0.2m vertical) bathymetry data and direct observations of the entire ridge segment, collected and performed by MBARI's autonomous underwater vehicle (AUV) and ROV dives, respectively, during the 2012 Expedition to the Gulf of California, have revealed the presence of an intense array of fault-scarps and fissures displacing numerous neovolcanic landforms such as huge lava domes and smaller cones, pillow mounds and large sheet flows along the entire ridge. The relative age of the surface ruptures is wide-ranging. At some places the fractures appear to be relatively recent, as evident by the apparent young age of the fractured flows, based on having few sessile organisms and/or relatively thin sediment cover. In contrast, fractures and fault-scarps elsewhere are observed to have been partially or totally overrun by lava flows, suggesting their preexistence and relatively older age. The ridge parallel faults and fissures change orientation dramatically as they approach and wrap around the bordering Pescadero and Tamayo fracture zones, which limit the northern and southern flanks of the rise, respectively, giving the ridge a sigmoidal geometry with a Z-shaped symmetry. Moreover, the presence of an en echelon volcanic fissure system near the southern end of the ridge, measuring several kilometers long and oriented somewhat obliquely (~15o clockwise) to

  10. A plate boundary earthquake record from a wetland adjacent to the Alpine fault in New Zealand refines hazard estimates

    Science.gov (United States)

    Cochran, U. A.; Clark, K. J.; Howarth, J. D.; Biasi, G. P.; Langridge, R. M.; Villamor, P.; Berryman, K. R.; Vandergoes, M. J.

    2017-04-01

    Discovery and investigation of millennial-scale geological records of past large earthquakes improve understanding of earthquake frequency, recurrence behaviour, and likelihood of future rupture of major active faults. Here we present a ∼2000 year-long, seven-event earthquake record from John O'Groats wetland adjacent to the Alpine fault in New Zealand, one of the most active strike-slip faults in the world. We linked this record with the 7000 year-long, 22-event earthquake record from Hokuri Creek (20 km along strike to the north) to refine estimates of earthquake frequency and recurrence behaviour for the South Westland section of the plate boundary fault. Eight cores from John O'Groats wetland revealed a sequence that alternated between organic-dominated and clastic-dominated sediment packages. Transitions from a thick organic unit to a thick clastic unit that were sharp, involved a significant change in depositional environment, and were basin-wide, were interpreted as evidence of past surface-rupturing earthquakes. Radiocarbon dates of short-lived organic fractions either side of these transitions were modelled to provide estimates for earthquake ages. Of the seven events recognised at the John O'Groats site, three post-date the most recent event at Hokuri Creek, two match events at Hokuri Creek, and two events at John O'Groats occurred in a long interval during which the Hokuri Creek site may not have been recording earthquakes clearly. The preferred John O'Groats-Hokuri Creek earthquake record consists of 27 events since ∼6000 BC for which we calculate a mean recurrence interval of 291 ± 23 years, shorter than previously estimated for the South Westland section of the fault and shorter than the current interseismic period. The revised 50-year conditional probability of a surface-rupturing earthquake on this fault section is 29%. The coefficient of variation is estimated at 0.41. We suggest the low recurrence variability is likely to be a feature of

  11. Iterative generalized synchrosqueezing transform for fault diagnosis of wind turbine planetary gearbox under nonstationary conditions

    Science.gov (United States)

    Feng, Zhipeng; Chen, Xiaowang; Liang, Ming

    2015-02-01

    The synchrosqueezing transform can effectively improve the readability of time-frequency representation of mono-component and constant frequency signals. However, for multi-component and time-variant frequency signals, it still suffers from time-frequency blurs. In order to address this issue, the synchrosqueezing transform is improved using iterative generalized demodulation. Firstly, the complex nonstationary signal is decomposed into mono-components of constant frequency by iterative generalized demodulation. Then, the instantaneous frequency of each mono-component is accurately estimated via the synchrosqueezing transform, by exploiting its merit of enhanced time-frequency resolution. Finally, the time-frequency representation of the original signal is obtained by superposing the time-frequency representations of all the mono-components with restored instantaneous frequency. This proposed method generalizes the synchrosqueezing transform to multi-component and time-variant frequency signals, and it has fine time-frequency resolution and is free of cross-term interferences. The proposed method was validated using both numerically simulated and lab experimental vibration signals of planetary gearboxes under nonstationary conditions. The time-variant planetary gearbox characteristic frequencies were effectively identified, and the gear faults were correctly diagnosed.

  12. Tectonic role of margin-parallel and margin-transverse faults during oblique subduction in the Southern Volcanic Zone of the Andes: Insights from Boundary Element Modeling

    Science.gov (United States)

    Stanton-Yonge, A.; Griffith, W. A.; Cembrano, J.; St. Julien, R.; Iturrieta, P.

    2016-09-01

    Obliquely convergent subduction margins develop trench-parallel faults shaping the regional architecture of orogenic belts and partitioning intraplate deformation. However, transverse faults also are common along most orogenic belts and have been largely neglected in slip partitioning analysis. Here we constrain the sense of slip and slip rates of differently oriented faults to assess whether and how transverse faults accommodate plate-margin slip arising from oblique subduction. We implement a forward 3-D boundary element method model of subduction at the Chilean margin evaluating the elastic response of intra-arc faults during different stages of the Andean subduction seismic cycle (SSC). Our model results show that the margin-parallel, NNE striking Liquiñe-Ofqui Fault System accommodates dextral-reverse slip during the interseismic period of the SSC, with oblique slip rates ranging between 1 and 7 mm/yr. NW striking faults exhibit sinistral-reverse slip during the interseismic phase of the SSC, displaying a maximum oblique slip of 1.4 mm/yr. ENE striking faults display dextral strike slip, with a slip rate of 0.85 mm/yr. During the SSC coseismic phase, all modeled faults switch their kinematics: NE striking fault become sinistral, whereas NW striking faults are normal dextral. Because coseismic tensile stress changes on NW faults reach 0.6 MPa at 10-15 km depth, it is likely that they can serve as transient magma pathways during this phase of the SSC. Our model challenges the existing paradigm wherein only margin-parallel faults account for slip partitioning: transverse faults are also capable of accommodating a significant amount of plate-boundary slip arising from oblique convergence.

  13. Generalized stepwise demodulation transform and synchrosqueezing for time-frequency analysis and bearing fault diagnosis

    Science.gov (United States)

    Shi, Juanjuan; Liang, Ming; Necsulescu, Dan-Sorin; Guan, Yunpeng

    2016-04-01

    The energy concentration level is an important indicator for time-frequency analysis (TFA). Weak energy concentration would result in time-frequency representation (TFR) diffusion and thus leading to ambiguous results or even misleading signal analysis results, particularly for nonstationary multicomponent signals. To improve the energy concentration level, this paper proposes a generalized stepwise demodulation transform (GSDT). The rationale of the proposed method is that (1) the generalized demodulation (GD) can map the original signal into an analytic signal with constant instantaneous frequency (IF) and improve the energy concentration level on time-frequency plane, and (2) focusing on a short window around the time instant of interest, a backward demodulation operation can recover the original frequency at the time instant without affecting the improved energy concentration level. By repeating the backward demodulation at every time instant of interest, the TFR of the entire signal can be attained with enhanced energy concentration level. With the GSDT, an iterative GSDT (IGSDT) is developed to analyze multicomponent signal that is subjected to different modulating sources for their constituent components. The IGSDT iteratively demodulates each constituent component to attain its TFR and the TFR of the whole signal is derived from superposing all the resulting TFRs of constituent components. The cross-term free and more energy concentrated TFR of the signal is, therefore, obtained, and the diffusion in the TFR can be reduced. The GSDT-based synchrosqueezing transform is also elaborated to further enhance the GSDT(IGSDT) yielded TFR. The effectiveness of the proposed method in TFA is tested using both simulated monocomponent and multicomponent signals. The application of the proposed method to bearing fault detection is explored. Bearing condition and fault pattern can be revealed by the proposed method resulting TFR. The main advantages of the proposed method

  14. Evidence for ground-rupturing earthquakes on the Northern Wadi Araba fault at the archaeological site of Qasr Tilah, Dead Sea Transform fault system, Jordan

    Science.gov (United States)

    Haynes, Jeremy M.; Niemi, Tina M.; Atallah, Mohammad

    2006-10-01

    The archaeological site of Qasr Tilah, in the Wadi Araba, Jordan is located on the northern Wadi Araba fault segment of the Dead Sea Transform. The site contains a Roman-period fort, a late Byzantine Early Umayyad birkeh (water reservoir) and aqueduct, and agricultural fields. The birkeh and aqueduct are left-laterally offset by coseismic slip across the northern Wadi Araba fault. Using paleoseismic and archaeological evidence collected from a trench excavated across the fault zone, we identified evidence for four ground-rupturing earthquakes. Radiocarbon dating from key stratigraphic horizons and relative dating using potsherds constrains the dates of the four earthquakes from the sixth to the nineteenth centuries. Individual earthquakes were dated to the seventh, ninth and eleventh centuries. The fault strand that slipped during the most recent event (MRE) extends to just below the modern ground surface and juxtaposes alluvial-fan sediments that lack in datable material with the modern ground surface, thus preventing us from dating the MRE except to constrain the event to post-eleventh century. These data suggest that the historical earthquakes of 634 or 659/660, 873, 1068, and 1546 probably ruptured this fault segment.

  15. The buried southern continuation of the Oaxaca-Juarez terrane boundary and Oaxaca Fault, southern Mexico: Magnetotelluric constraints

    Science.gov (United States)

    Campos-Enriquez, J. O.; Corbo-Camargo, F.; Arzate-Flores, J.; Keppie, J. D.; Arango-Galván, C.; Unsworth, M.; Belmonte-Jiménez, S. I.

    2013-04-01

    Thirty magnetotelluric soundings were made along two NW-SE profiles to the north and south of Oaxaca City in southern Mexico. The profiles crossed the N-S Oaxaca Fault and the Oaxaca-Juarez terrane boundary defined by the Juarez mylonitic complex. Dimensionality analysis of the MT data showed that the subsurface resistivity structure is 2D or 3D. The Oaxaca and correlative Guichicovi terranes consist of ca. 1-1.4 Ga granulitic continental crust overlain by Phanerozoic sedimentary rocks, characterized by high and low resistivities, respectively. The Juarez terrane consists of oceanic Mesozoic metavolcanic and metasedimentary rocks, characterized by a low to medium resistivity layer, that is approximately 10 km thick. The Oaxaca Fault is a Cenozoic aged, normal fault that reactivated the dextral and thrust Juarez mylonitic complex north of Oaxaca City: its location south of Oaxaca City is uncertain. In the southern profile, the MT data show a ca. 20-50 km wide, west-dipping, relatively low resistivity zone material that extends through the entire crust. This is inferred to be the Juarez terrane bounded on either side by the ca. 1-1.4 Ga granulites. The Oaxaca Fault is imaged only by a major electrical resistivity discontinuity (low to the west, high to the east) along both the western border of the Juarez mylonitic complex (northern profile) and the San Miguel de la Cal mountains (southern profile) suggesting continuity.

  16. Novel indices for broken rotor bars fault diagnosis in induction motors using wavelet transform

    Science.gov (United States)

    Ebrahimi, Bashir Mahdi; Faiz, Jawad; Lotfi-fard, S.; Pillay, P.

    2012-07-01

    This paper introduces novel indices for broken rotor bars diagnosis in three-phase induction motors based on wavelet coefficients of stator current in a specific frequency band. These indices enable to diagnose occurrence and determine number of broken bars in different loads precisely. Besides thanks to the suitability of wavelet transform in transient conditions, it is possible to detect the fault during the start-up of the motor. This is important in the case of start-up of large induction motors with long starting time and also motors with frequent start-up. Furthermore, broken rotor bars in induction motor are detected using spectra analysis of the stator current. It is also shown that rise of number of broken bars and load levels increases amplitude of the particular side-band components of the stator currents in the faulty case. An induction motor with 1, 2, 3 and 4 broken bars at the rated load and the motor with 4 broken bars at no-load, 33%, 66%, 100% and 133% rated load are investigated. Time stepping finite element method is used for modeling broken rotor bars faults in induction motors. In this modeling, effects of the stator winding distribution, stator and rotor slots, geometrical and physical characteristics of different parts of the motor and non-linearity of the core materials are taken into account. The simulation results are are verified by the experimental results.

  17. Research of converter transformer fault diagnosis based on improved PSO-BP algorithm

    Science.gov (United States)

    Long, Qi; Guo, Shuyong; Li, Qing; Sun, Yong; Li, Yi; Fan, Youping

    2017-09-01

    To overcome those disadvantages that BP (Back Propagation) neural network and conventional Particle Swarm Optimization (PSO) converge at the global best particle repeatedly in early stage and is easy trapped in local optima and with low diagnosis accuracy when being applied in converter transformer fault diagnosis, we come up with the improved PSO-BP neural network to improve the accuracy rate. This algorithm improves the inertia weight Equation by using the attenuation strategy based on concave function to avoid the premature convergence of PSO algorithm and Time-Varying Acceleration Coefficient (TVAC) strategy was adopted to balance the local search and global search ability. At last the simulation results prove that the proposed approach has a better ability in optimizing BP neural network in terms of network output error, global searching performance and diagnosis accuracy.

  18. Recent movements along the Main Boundary Thrust of the Himalayas: Normal faulting in an over-critical thrust wedge?

    Science.gov (United States)

    Mugnier, Jean-Louis; Huyghe, Pascale; Chalaron, Edouard; Mascle, Georges

    1994-11-01

    The Main Boundary Thrust (MBT) is one of the major Himalayan thrusts occurring during the Cainozoic, and it is presently incorporated within the Himalayan thrust wedge (Lesser and Outer Himalayas) displaced above the Indian lithosphere. Nonetheless the MBT shows recent normal displacement along most of its length. We suggest that the orientation of the major principal stress within the Himalayan thrust wedge deviates significantly from the horizontal and when this deviation exceeds the dip of the vectors normal to back-tilted thrusts, the normal component of displacement may act along these faults. Steep north-dipping segments of the MBT therefore show a normal component of displacement if a geometrical definition is used, but they are faults in a compressional regime where the major principal stress axis has deviated from the horizontal. Micro-structural data recorded along the Surkhet-Ghorahi segment of the MBT are consistent with a strong deviation of the state of stress. The presence of such peculiar normal faulting along the MBT is used to calibrate the mechanical characteristics of the belt considered as a Coulomb wedge. The following characteristics are suggested: (a) very poor strength contrast between basal decollement and rocks in the wedge body, (b) a high pore fluid pressure ratio (probably close to 0.8-0.9) and a higher fluid pressure ratio (close to 1.0) along the active normal faults if a high internal friction angle (close to the Byerlee value) is considered. The strong deviation in principal stress direction may have recently increased, due to a taper of the Himalayan wedge exceeding the stability boundary and may be controlled by erosion and isostatic uplift rebound of the Himalayan range.

  19. Incipient Gearbox Fault Diagnosis Based on the Reverse State Transformation of the Chaotic Duffing Oscillator and Sampling Integral Technology

    Directory of Open Access Journals (Sweden)

    Li Jie

    2015-01-01

    Full Text Available Incipient fault for a gearbox diagnosis is difficult because the signals with low signal-to-noise ratio (SNR are corrupted with background noise. A method based on chaos theory and sampling integral technology will be presented to detect the incipient fault of gearbox according to the characters of the gearbox vibration signals. Sampling integral technology was used to improve the tracking ability of fault signals with lower SNR. The small changes in the sidebands of meshing frequency can be detected by the transformation of chaotic phase diagram and its Hu moment invariants, and on this basis the incipient faults can be diagnosed. The results based on gearboxes experiment justify the effectiveness of the method.

  20. Solution Transformations and Their Effects on the Systems with Open Boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    JU Guo-Xing; ZHAO Xian-Lin

    2002-01-01

    The solution transformations and properties of the R-matrices for two-component systems uner these transformations are analyzed in details.Not all transformed R-matrices can be put into the Skalyanin's formalism.For those R-matrices with all required properties,the effects of solution transformations to the six- and eight-vertex systems with open boundary conditions are discussed.These effects can be one of the following types: The Hamiltonian is invariant or transposition-invariant or made in a similarity transformation,or its coupling coefficients are multiplied by an overall factor,or the spin of the system is rotated around the z axis or/and reflected with respect to some plane.In these cases,the transformed systems remain to be integrable.

  1. Constraints on fault slip rates of the southern California plate boundary from GPS velocity and stress inversions

    Science.gov (United States)

    Becker, T.W.; Hardebeck, J.L.; Anderson, G.

    2005-01-01

    We use Global Positioning System (GPS) velocities and stress orientations inferred from seismicity to invert for the distribution of slip on faults in the southern California plate-boundary region. Of particular interest is how long-term slip rates are partitioned between the Indio segment of the San Andreas fault (SAF), the San Jacinto fault (SJF) and the San Bernardino segment of the SAE We use two new sets of constraints to address this problem. The first is geodetic velocities from the Southern California Earthquake Center's (SCEC) Crustal Motion Map (version 3 by Shen et al.), which includes significantly more data than previous models. The second is a regional model of stress-field orientations at seismogenic depths, as determined from earthquake focal mechanisms. While GPS data have been used in similar studies before, this is the first application of stress-field observations to this problem. We construct a simplified model of the southern California fault system, and estimate the interseismic surface velocities using a backslip approach with purely elastic strain accumulation, following Meade et al. In addition, we model the stress orientations at seismogenic depths, assuming that crustal stress results from the loading of active faults. The geodetically derived stressing rates are found to be aligned with the stress orientations from seismicity. We therefore proceed to invert simultaneously GPS and stress observations for slip rates of the faults in our network. We find that the regional patterns of crustal deformation as imaged by both data sets can be explained by our model, and that joint inversions lead to better constrained slip rates. In our preferred model, the SJF accommodates ???15 mm yr-1 and the Indio segment of the SAF ???23 mm yr-1 of right-lateral motion, accompanied by a low slip rate on the San Bernardino segment of the SAF 'Anomalous' fault segments such as around the 1992 Mw = 7.3 Landers surface rupture can be detected. There, observed

  2. Breakdown of Shape Memory Effect in Bent Cu-Al-Ni Nanopillars: When Twin Boundaries Become Stacking Faults.

    Science.gov (United States)

    Liu, Lifeng; Ding, Xiangdong; Sun, Jun; Li, Suzhi; Salje, Ekhard K H

    2016-01-13

    Bent Cu-Al-Ni nanopillars (diameters 90-750 nm) show a shape memory effect, SME, for diameters D > 300 nm. The SME and the associated twinning are located in a small deformed section of the nanopillar. Thick nanopillars (D > 300 nm) transform to austenite under heating, including the deformed region. Thin nanopillars (D < 130 nm) do not twin but generate highly disordered sequences of stacking faults in the deformed region. No SME occurs and heating converts only the undeformed regions into austenite. The defect-rich, deformed region remains in the martensite phase even after prolonged heating in the stability field of austenite. A complex mixture of twins and stacking faults was found for diameters 130 nm < D < 300 nm. The size effect of the SME in Cu-Al-Ni nanopillars consists of an approximately linear reduction of the SME between 300 and 130 nm when the SME completely vanishes for smaller diameters.

  3. Fault feature extraction of gearbox by using overcomplete rational dilation discrete wavelet transform on signals measured from vibration sensors

    Science.gov (United States)

    Chen, Binqiang; Zhang, Zhousuo; Sun, Chuang; Li, Bing; Zi, Yanyang; He, Zhengjia

    2012-11-01

    Gearbox fault diagnosis is very important for preventing catastrophic accidents. Vibration signals of gearboxes measured by sensors are useful and dependable as they carry key information related to the mechanical faults in gearboxes. Effective signal processing techniques are in necessary demands to extract the fault features contained in the collected gearbox vibration signals. Overcomplete rational dilation discrete wavelet transform (ORDWT) enjoys attractive properties such as better shift-invariance, adjustable time-frequency distributions and flexible wavelet atoms of tunable oscillation in comparison with classical dyadic wavelet transform (DWT). Due to these advantages, ORDWT is presented as a versatile tool that can be adapted to analysis of gearbox fault features of different types, especially in analyzing the non-stationary and transient characteristics of the signals. Aiming to extract the various types of fault features confronted in gearbox fault diagnosis, a fault feature extraction technique based on ORDWT is proposed in this paper. In the routine of the proposed technique, ORDWT is used as the pre-processing decomposition tool, and a corresponding post-processing method is combined with ORDWT to extract the fault feature of a specific type. For extracting periodical impulses in the signal, an impulse matching algorithm is presented. In this algorithm, ORDWT bases of varied time-frequency distributions and varied oscillatory natures are adopted, moreover an improved signal impulsiveness measure derived from kurtosis is developed for choosing optimal ORDWT bases that perfectly match the hidden periodical impulses. For demodulation purpose, an improved instantaneous time-frequency spectrum (ITFS), based on the combination of ORDWT and Hilbert transform, is presented. For signal denoising applications, ORDWT is enhanced by neighboring coefficient shrinkage strategy as well as subband selection step to reveal the buried transient vibration contents. The

  4. New Bathymetry Reveals Detailed History of Transform Fault Segmentation at the Clarion Fracture Zone

    Science.gov (United States)

    Morrow, T. A.; Kim, S. S.; Mittelstaedt, E. L.; Olive, J. A. L.; Howell, S. M.

    2016-12-01

    Between 150°W and 135°W, the Clarion Fracture Zone (FZ) coalesces from six discrete FZ traces to a single FZ over a period of 30 million years, coinciding with a change in plate motion that placed the associated transform fault (TF) in compression. Although FZ observations suggest segmented TFs may unify to a single TF as a response to tectonic compression, little is known about the timing of this process, as well as how it may alter lithosphere structure. Using new bathymetry and gravity data from the Clarion FZ, we investigate this process through interpreted structural maps of the seafloor, numerical simulations of a segmented FZ, and modeling of gravitational anomalies. From 3154 mapped volcanic ridges and faults, we observe temporally correlated changes in intra-transform spreading center (ITSC) fabrics and plate motions that suggest that ITSC fabrics further from the center of the FZ responded to compressional changes in plate motion sooner (up to 5 million years) than ITSC fabrics located near the center of the FZ. Using the 2D finite-difference, visco-elastic-plastic code SiStER, we simulate the tectonic evolution of a differentially cooling lithosphere broken by several FZs and subject to compression or extension. We vary parameters such as the number of initial ITSC segments (0-4) and the rate of compression or extension (0-4.5 mm/year). In some model cases, we also vary the strength of the initial FZ offset by introducing small, low-viscosity weaknesses in the modeled lithosphere at the FZ. Gravity anomalies are calculated from the simulated lithospheric structure by using Talwani's 2D polygon algorithm. We then compare model predicted and existing satellite-derived gravity anomalies over the segmented Clarion FZ to constrain the relative timing of compressional changes along individual transform segment traces and structural changes within the FZ. Our observations suggest that compression and extension are not uniformly distributed across a segmented

  5. Transformational leadership climate : Performance linkages, mechanisms, and boundary conditions at the organizational level

    NARCIS (Netherlands)

    Menges, J.; Walter, F.; Vogel, B.; Bruch, H.

    2011-01-01

    Transformational leadership (TFL) climate describes the degree to which leaders throughout an organization engage in TFL behaviors. In this study, we investigate performance linkages, mechanisms, and boundary conditions of TFL climate at the organizational level of analysis. In a sample of 158

  6. Transformational leadership climate : Performance linkages, mechanisms, and boundary conditions at the organizational level

    NARCIS (Netherlands)

    Menges, J.; Walter, F.; Vogel, B.; Bruch, H.

    2011-01-01

    Transformational leadership (TFL) climate describes the degree to which leaders throughout an organization engage in TFL behaviors. In this study, we investigate performance linkages, mechanisms, and boundary conditions of TFL climate at the organizational level of analysis. In a sample of 158 indep

  7. Transformational leadership climate : Performance linkages, mechanisms, and boundary conditions at the organizational level

    NARCIS (Netherlands)

    Menges, J.; Walter, F.; Vogel, B.; Bruch, H.

    2011-01-01

    Transformational leadership (TFL) climate describes the degree to which leaders throughout an organization engage in TFL behaviors. In this study, we investigate performance linkages, mechanisms, and boundary conditions of TFL climate at the organizational level of analysis. In a sample of 158 indep

  8. A New Estimate for Total Offset on the Southern San Andreas Fault: Implications for Cumulative Plate Boundary Shear in the Northern Gulf of California

    Science.gov (United States)

    Darin, M. H.; Dorsey, R. J.

    2012-12-01

    Development of a consistent and balanced tectonic reconstruction for the late Cenozoic San Andreas fault (SAF) in southern California has been hindered for decades by incompatible estimates of total dextral offset based on different geologic cross-fault markers. The older estimate of 240-270 km is based on offset fluvial conglomerates of the middle Miocene Mint Canyon and Caliente Formations west of the SAF from their presumed source area in the northern Chocolate Mountains NE of the SAF (Ehlig et al., 1975; Ehlert, 2003). The second widely cited offset marker is a distinctive Triassic megaporphyritic monzogranite that has been offset 160 ± 10 km between Liebre Mountain west of the SAF and the San Bernadino Mountains (Matti and Morton, 1993). In this analysis we use existing paleocurrent data and late Miocene clockwise rotation in the eastern Transverse Ranges (ETR) to re-assess the orientation of the piercing line used in the 240 km-correlation, and present a palinspastic reconstruction that satisfies all existing geologic constraints. Our reconstruction of the Mint Canyon piercing line reduces the original estimate of 240-270 km to 195 ± 15 km of cumulative right-lateral slip on the southern SAF (sensu stricto), which is consistent with other published estimates of 185 ± 20 km based on correlative basement terranes in the Salton Trough region. Our estimate of ~195 km is consistent with the lower estimate of ~160 km on the Mojave segment because transform-parallel extension along the southwestern boundary of the ETR during transrotation produces ~25-40 km of displacement that does not affect offset markers of the Liebre/San Bernadino correlation located northwest of the ETR rotating domain. Reconciliation of these disparate estimates places an important new constraint on the total plate boundary shear that is likely accommodated in the adjacent northern Gulf of California. Global plate circuit models require ~650 km of cumulative Pacific-North America (PAC

  9. Remote Identification and Characterization of Fault Scarps Along the Pacific-North American Plate Boundary Using Airborne Laser Swath Mapping (ALSM) Data and Wavelet Analysis

    Science.gov (United States)

    Sanquini, A.; Hilley, G. E.; Prentice, C. S.

    2012-12-01

    Remote, automatic identification of the location, relative geomorphic age and orientation of possible fault scarps is explored and evaluated by applying wavelet analysis to high-resolution Airborne Laser Swath Mapping (ALSM) topographic data. This methodology compares a scarp model to digital elevation models (DEMs) created from ALSM data collected by the National Center for Airborne Laser Mapping along major faults in California. Fault scarp degradation is modeled using a diffusive transport rule. This modeled topographic form is used to create a wavelet based on the profile curvature of a scarp that is elongated in the out-of-profile dimension and rotated into a wide variety of orientations. This is convolved with the surface curvature computed from the ALSM DEM to isolate areas where the actual topography best conforms to the template. We present results from swaths constructed along active plate-boundary faults, including the Maacama and Rodgers Creek faults, the Calaveras and Paicines faults, the Green Valley fault, the Eastern California Shear Zone, and major sections of the San Andreas fault. In general, we find that this methodology performs well in automatically identifying previously mapped faults and it hints at the existence of faults that are not mapped. The method also identifies scarp forms that are clearly not created by faults, such as those along linear man-made structures and thus is not a fully automated solution. Future work includes quantification of false positive and negative rates of features identified as fault scarps in areas where the fault geometry has been mapped in the field, as well as the creation and application of a methodology that can identify scarps that are produced by multiple offset events.

  10. Early fault feature extraction of rolling bearing based on ICD and tunable Q-factor wavelet transform

    Science.gov (United States)

    Li, Yongbo; Liang, Xihui; Xu, Minqiang; Huang, Wenhu

    2017-03-01

    When a fault occurs on bearings, the measured bearing fault signals contain both high Q-factor oscillation component and low Q-factor periodic impact component. TQWT is the improvement of the traditional single Q-factor wavelet transform, which is very suitable for separating the low Q-factor component from the high Q-factor component. However, the accuracy of its decomposition heavily depended on the selection of Q-factors. There is no reported simple but effective method to select the Q-factors with enough accuracy. This study aims to develop a strategy to diagnostic the early fault of rolling bearings. In this paper, a characteristic frequency ratio (CFR) is used to optimize Q-factors of TQWT (OTQWT). However, directly application of OTQWT is difficult to extract fault signatures at early stage due to the weak fault symptoms and strong noise. A strategy of combination of intrinsic characteristic-scale decomposition (ICD) and TQWT is proposed. ICD owns significant advantages on computation efficiency and alleviation of mode mixing. The effectiveness of the proposed strategy is tested with both simulated and experimental vibration signals. Meanwhile, comparisons are conducted between the proposed method and other methods like: envelope demodulation and EEMD-TQWT. Results show that the proposed method has superior performance in extracting fault features of defective bearings at an early stage.

  11. New constraints on seismic anisotropy along the Dead Sea transform fault

    Science.gov (United States)

    Kaviani, A.; Rumpker, G.; Asch, G.

    2009-12-01

    We study seismic anisotropy along the Dead Sea Transform fault (DST) by shear-wave splitting analysis of SKS and SKKS waveforms recorded at a dense network of broad-band and short-period stations of the DESIRE experiment. The DST accommodates the relative motion between Africa and Arabia through a sinistral strike-slip motion. The Dead Sea is a pull-apart basin formed along the DST as a result of stepwise fault-normal displacement. The DESIRE array of stations cover this portion of the DST. We measured the splitting parameters (delay times between the fast and slow components of the shear wave and fast polarization direction) in different period bands. We observed consistent fast polarization directions varying from N14W to N19E at different stations and delay times ranging between 1.0 and 2.5 s. Our preliminary examination reveals that the splitting parameters do not exhibit significant frequency dependence. However, we observe variations in the splitting parameters (mostly delay times) along an E-W profile crossing the DST, with smaller delay times in the middle of the profile, within the surface exposure of the DST shear zone, and with two lobes of relatively large delay times on both sides of the central region. The fast polarization directions along this profile change from a dominant NNW trend in the western side of the DST to a general N-S orientation in the central part and a dominant NNE trend to the east. Waveform modeling is required to infer the lateral and depth variations of the strength and orientation of anisotropy in the crust and upper mantle from these observations. We will also complement our results with the data from the DESERT experiment to provide an overall pattern of seismic anisotropy and structural fabric beneath the DST and surrounding regions from the north of the Dead Sea down to the Red sea.

  12. A combined method for triplex pump fault diagnosis based on wavelet transform, fuzzy logic and neuro-networks

    Science.gov (United States)

    Kong, Fansen; Chen, Ruheng

    2004-01-01

    A new combined method based on wavelet transformation, fuzzy logic and neuro-networks is proposed for fault diagnosis of a triplex. The failure characteristics of the fluid- and dynamic-end can be divided into wavelet transform in different scales at the same time (in: Jun Zhu et al. (Eds.), Proceedings of an International Conference on Condition Monitoring. National Defense Industry Press, Beijing, 1997, pp. 271-275). Therefore, the characteristic variables can be constructed making use of the coefficients of Edgeworth asymptotic spectrum expansion formula and fuzzified to train the neuro-network to identify the faults of fluid- and dynamic-end of triplex pump in fuzzy domain. Tests indicate that the information of wavelet transformation in scale 2 is related to the meshing state of the gear and the information in scales 4 and 5 is related to the running state of fluid-end. Good agreement between analytical and experimental results has been obtained.

  13. Bearing Fault Diagnosis Using a Novel Classifier Ensemble Based on Lifting Wavelet Packet Transforms and Sample Entropy

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2016-01-01

    Full Text Available In order to improve the fault detection accuracy for rolling bearings, an automated fault diagnosis system is presented based on lifting wavelet packet transform (LWPT, sample entropy (SampEn, and classifier ensemble. Bearing vibration signals are firstly decomposed into different frequency subbands through a three-level LWPT, resulting in a total of 8 frequency-band signals throughout the third layers of the LWPT decomposition tree. The SampEns of all the 8 components are then calculated as feature vectors. Such a feature extraction paradigm is expected to depict complexity, irregularity, and nonstationarity of bearing vibrations. Moreover, a novel classifier ensemble is proposed to alleviate the effect of initial parameters on the performance of member classifiers and to improve classification effectiveness. Experiments were conducted on electric motor bearings considering various set of fault categories and fault severity levels. Experimental results demonstrate the proposed diagnosis system can effectively improve bearing fault recognition accuracy and stability in comparison with diagnosis methods based on a single classifier.

  14. Discrete wavelet transform-based fault diagnosis for driving system of pipeline detection robot arm

    Institute of Scientific and Technical Information of China (English)

    Deng Huiyu; Wang Xinli; Ma Peisun

    2005-01-01

    A real-time wavelet multi-resolution analysis (MRA)-based fault detection algorithm is proposed. The first stage detailed MRA signals extracted from the original signals were used as the criteria for fault detection. By measuring sharp variations in the detailed MRA signals, faults in the motor driving system of pipeline detection robot arm could be detected. The fault type was then identified by comparison of the three-phase MRA sharp variations. The effects of the faults were examined. The simulation results show that this algorithm is effective and robust, it is promising for fault detection in a robot's joint driving system. The method is simple, rapid and it can operate in real time.

  15. Inverse scattering transform for the derivative nonlinear Schrödinger equation with nonvanishing boundary conditions.

    Science.gov (United States)

    Chen, Xiang-Jun; Lam, Wa Kun

    2004-06-01

    An inverse scattering transform for the derivative nonlinear Schrödinger equation with nonvanishing boundary conditions is derived by introducing an affine parameter to avoid constructing Riemann sheets. A one-soliton solution simpler than that in the literature is obtained, which is a breather and degenerates to a bright or dark soliton as the discrete eigenvalue becomes purely imaginary. The solution is mapped to that of the modified nonlinear Schrödinger equation by a gaugelike transformation, predicting some sub-picosecond solitons in optical fibers.

  16. An iterative method for controlling reactive power flow in boundary transformers

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, Angel L.; Martinez, Jose L.; Riquelme, Jesus; Romero, Esther [Department of Electrical Engineering, University of Seville (Spain)

    2011-02-15

    This paper presents an operational tool designed to help the system operator to control the reactive power flow in transmission-subtransmission boundary transformers. The main objective is to determine the minimum number of control actions necessary to ensure that reactive power flows in transmission/subtransmission transformers remain within limits. The proposed iterative procedure combines the use of a linear programming problem and a load flow tool. The linear programming assumes a linear behaviour between dependent and control variables around an operating point, modelled with sensitivities. Experimental results regarding IEEE systems are provided comparing the performance of the proposed approach with that of a conventional optimal power flow. (author)

  17. Influence of inherited features on the boundaries and fault patterns of the Transtensional Gulf of California to Walker Lane/Basin and Range

    Science.gov (United States)

    Umhoefer, P. J.

    2012-12-01

    The Basin and Range (BR) includes a continuous belt from the Gulf of California extensional province of Mexico through Southwestern USA to the Walker Lane and northern BR. This includes the core extensional to transtensional belt that lies east of the Pacific - North America (PAC-NAM) plate boundary. Much of the BR is the result of the westward to northwestward motion of the Baja California and Sierra Nevada microplates away from North America during PAC-NAM motion. These microplates are parts of the Cretaceous batholith and the eastern edge of the batholiths define the western edge of the BR. The transtensional faulting of eastern Baja California and Walker Lane are remarkably similar and show down-to-the-east normal faults along the batholith boundary. To the east are linked normal and strike-slip faults, the latter striking from parallel to relative motion of the microplates to nearly parallel to the batholith boundary. The Walker Lane boundary has domains of strain partitioning and other domains with northwesterly regional shear and no partitioning. Why certain areas are partitioned is not known, but secondary inherited structures may play a role. The eastern edge of the BR is dominated by the Sierra Madre Occidental and the Colorado Plateau and is more variable in faulting patterns because the boundary is more variable in shape, the previous geologic history is more complex, and most extension occurred just before and in the early stage of PAC-NAM motion. The Sierra Madre is likely underlain by a large batholith formed during caldera eruptions in the Oligocene; this batholith roughly parallels the Cretaceous batholith on the Baja California microplate and the SE BR is dominated by early extensional faults. The southern and western edges of the Colorado Plateau form the eastern boundary of the BR in the north with mainly ENE-directed core complexes in pre-17-15 Ma PAC-NAM history. Extension near Las Vegas 17 - ~10 Ma was westward and the inherited NE

  18. WAVELET TRANSFORM METHOD FOR DERIVING ATMOSPHERIC BOUNDARY LAYER HEIGHT FROM LIDAR SIGNALS

    OpenAIRE

    RAJITHA PALETI; Y. Bhavani Kumar; T. Krishna Chaitanya

    2013-01-01

    Wavelet method of determining the atmospheric boundary layer (ABL) height from lidar signals is presented in this paper. The wavelet covariance transform (WCT) method employed determines the significant gradient in the measured lidar signals. Using this method, the accuracy of ABL height detection enhances with increased dilation length. The developed wavelet algorithm is coded in MATLAB software and has a provision to alter the dilation length in real-time for a given translation estimate.

  19. Laplace Transform Methods for a Free Boundary Problem of Time-Fractional Partial Differential Equation System

    Directory of Open Access Journals (Sweden)

    Zhiqiang Zhou

    2017-01-01

    Full Text Available We study the pricing of the American options with fractal transmission system under two-state regime switching models. This pricing problem can be formulated as a free boundary problem of time-fractional partial differential equation (FPDE system. Firstly, applying Laplace transform to the governing FPDEs with respect to the time variable results in second-order ordinary differential equations (ODEs with two free boundaries. Then, the solutions of ODEs are expressed in an explicit form. Consequently the early exercise boundaries and the values for the American option are recovered using the Gaver-Stehfest formula. Numerical comparisons of the methods with the finite difference methods are carried out to verify the efficiency of the methods.

  20. Free-boundary high-beta tokamaks. II. Mathematical intermezzo: Hilbert transforms and conformal mapping

    Science.gov (United States)

    Goedbloed, J. P.

    1982-11-01

    Mathematical techniques are described that facilitate the reduction of the stability problem of a toroidal free-boundary high-β tokamak equilibrium with skin currents to one that is basically one-dimensional. This includes the conformal mapping of the simply connected plasma region onto a circular disk and the conformal mapping of the doubly connected vacuum region onto an annulus by means of the Theodorsen and Garrick nonlinear integral equations. Henrici's method of constructing the discretized Hilbert transforms for periodic functions on the boundaries of these domains provides both the basis for constructing the mappings and the tool for the study of the perturbations. The methods are applied to problems of two-dimensional potential flow with a discontinuity of which the stability of sharp-boundary high-β tokamaks is just a special case.

  1. Seismic heating signatures in the Japan Trench subduction plate-boundary fault zone: evidence from a preliminary rock magnetic `geothermometer'

    Science.gov (United States)

    Yang, Tao; Dekkers, Mark J.; Zhang, Bo

    2016-04-01

    Frictional heating during earthquake rupture reveals important information on earthquake mechanisms and energy dissipation. The amount of annealing varies widely and is, as yet, poorly constrained. Here we use magnetic susceptibility versus temperature measurements during cycling to increasingly elevated temperatures to constrain the maximum temperature a slip zone has experienced. The case study comprises sheared clay cored from the Japan Trench subduction plate-boundary fault zone (décollement), which accommodated the large slip of the 2011 Mw 9.0 Tohoku-oki earthquake. The décollement was cored during the Integrated Ocean Drilling Program (IODP) Expedition 343, the Japan Trench Fast Drilling Project (JFAST). Heating signatures with estimated maximum temperatures ranging from ˜300 to over 500 °C are determined close to the multiple slip surfaces within the décollement. Since it is impossible to tie a specific slip surface to a certain earthquake, thermal evidence for the cumulative effect of several earthquakes is unveiled. This as yet preliminary rock magnetic `geothermometer' would be a useful tool to detect seismic heating along faults that experienced medium temperature rise, a range which is difficult to assess with other approaches.

  2. Searching for Active Faults in the Western Eurasia-Nubia plate boundary

    Science.gov (United States)

    Antunes, Veronica; Custodio, Susana; Arroucau, Pierre; Carrilho, Fernando

    2016-04-01

    The repeated occurrence of large magnitude earthquakes in southwest Iberia in historical and instrumental times suggests the presence of active faults in the region. However, the region undergoes slow deformation, which results in low rates of seismic activity, and the location, dimension and geometry of active structures remains unsettled. We recently developed a new algorithm for earthquake location in 3D complex media with laterally varying interface depths, which allowed us to relocate 2363 events that occurred from 2007 to 2013. The method takes as inputs P- and S-wave catalog arrival times obtained from the Portuguese Meteorological Institute (IPMA, Instituto Portugues do Mar e da Atmosfera), for a study area defined by 8.5°W < lon < 5°W and 36° < lat < 37.5°. After relocation, we obtain a lineation of events in the Guadalquivir bank region, in the northern Gulf of Cadiz. The lineation defines a low-angle northward-dipping plane rooted at the base of the crust, which could indicate the presence of a major fault. We provide seismological evidence for the existence of this seemingly active structure based on earthquake relocations, focal mechanisms and waveform similarity between neighboring events.

  3. A Novel Characteristic Frequency Bands Extraction Method for Automatic Bearing Fault Diagnosis Based on Hilbert Huang Transform

    Directory of Open Access Journals (Sweden)

    Xiao Yu

    2015-11-01

    Full Text Available Because roller element bearings (REBs failures cause unexpected machinery breakdowns, their fault diagnosis has attracted considerable research attention. Established fault feature extraction methods focus on statistical characteristics of the vibration signal, which is an approach that loses sight of the continuous waveform features. Considering this weakness, this article proposes a novel feature extraction method for frequency bands, named Window Marginal Spectrum Clustering (WMSC to select salient features from the marginal spectrum of vibration signals by Hilbert–Huang Transform (HHT. In WMSC, a sliding window is used to divide an entire HHT marginal spectrum (HMS into window spectrums, following which Rand Index (RI criterion of clustering method is used to evaluate each window. The windows returning higher RI values are selected to construct characteristic frequency bands (CFBs. Next, a hybrid REBs fault diagnosis is constructed, termed by its elements, HHT-WMSC-SVM (support vector machines. The effectiveness of HHT-WMSC-SVM is validated by running series of experiments on REBs defect datasets from the Bearing Data Center of Case Western Reserve University (CWRU. The said test results evidence three major advantages of the novel method. First, the fault classification accuracy of the HHT-WMSC-SVM model is higher than that of HHT-SVM and ST-SVM, which is a method that combines statistical characteristics with SVM. Second, with Gauss white noise added to the original REBs defect dataset, the HHT-WMSC-SVM model maintains high classification accuracy, while the classification accuracy of ST-SVM and HHT-SVM models are significantly reduced. Third, fault classification accuracy by HHT-WMSC-SVM can exceed 95% under a Pmin range of 500–800 and a m range of 50–300 for REBs defect dataset, adding Gauss white noise at Signal Noise Ratio (SNR = 5. Experimental results indicate that the proposed WMSC method yields a high REBs fault

  4. Fault Detection and Location by Static Switches in Microgrids Using Wavelet Transform and Adaptive Network-Based Fuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2014-04-01

    Full Text Available Microgrids are a highly efficient means of embedding distributed generation sources in a power system. However, if a fault occurs inside or outside the microgrid, the microgrid should be immediately disconnected from the main grid using a static switch installed at the secondary side of the main transformer near the point of common coupling (PCC. The static switch should have a reliable module implemented in a chip to detect/locate the fault and activate the breaker to open the circuit immediately. This paper proposes a novel approach to design this module in a static switch using the discrete wavelet transform (DWT and adaptive network-based fuzzy inference system (ANFIS. The wavelet coefficient of the fault voltage and the inference results of ANFIS with the wavelet energy of the fault current at the secondary side of the main transformer determine the control action (open or close of a static switch. The ANFIS identifies the faulty zones inside or outside the microgrid. The proposed method is applied to the first outdoor microgrid test bed in Taiwan, with a generation capacity of 360.5 kW. This microgrid test bed is studied using the real-time simulator eMegaSim developed by Opal-RT Technology Inc. (Montreal, QC, Canada. The proposed method based on DWT and ANFIS is implemented in a field programmable gate array (FPGA by using the Xilinx System Generator. Simulation results reveal that the proposed method is efficient and applicable in the real-time control environment of a power system.

  5. Four-Dimensional Transform Fault Processes: Evolution of Step-Overs and Bends at Different Scales

    Science.gov (United States)

    Wakabayashi, J.; Hengesh, J. V.; Sawyer, T. L.

    2002-12-01

    Many bends or step-overs along strike-slip faults may evolve by propagation of the strike-slip fault on one side of the structure and progressive shut off of the strike-slip fault on the other side. In such a process, new transverse structures form, old ones become inactive, and the bend or step-over region migrates with respect to materials that were once affected by it. This process is the progressive asymmetric development of a strike-slip duplex. Consequences of this type of step-over evolution include the following: 1. the amount of vertical structural relief in restraining step-over or bend regions is less than expected (apatite fission track ages associated with these step-over regions predate the strike-slip faulting); 2. pull-apart basin deposits are left outside of the active basin and commonly subjected to contractional deformation and uplift; and 3. local basin inversion occurs that is not linked to regional plate motion changes. This type of evolution of step-overs and bends may be common along the dextral San Andreas fault system of California. Examples of pull-apart basin deposits related to migrating releasing () bends or step-overs are the Plio-Pleistocene Merced Formation (tens of km along strike), the Pleistocene Olema Creek Formation (several km along strike) along the San Andreas fault in the San Francisco Bay area, and an inverted colluvial graben exposed in a paleoseismic trench across the Miller Creek fault (meters to tens of meters along strike) in the eastern San Francisco Bay area. Examples of migrating restraining bends or step-overs include the transfer of slip from the Calaveras to Hayward fault in the Mission Peak area, and the Greenville to the Concord fault at Mount Diablo (10 km or more along strike), the offshore San Gregorio fold and thrust belt (40 km along strike), and the progressive transfer of slip from the eastern faults of the San Andreas system to the migrating Mendocino triple junction (over 150 km along strike). Another

  6. Investigating the deformation of upper crustal faults at the N-Chilean convergent plate boundary at different scales using high-resolution topography datasets and creepmeter measurements

    Science.gov (United States)

    Ewiak, O.; Victor, P.; Ziegenhagen, T.; Oncken, O.

    2012-04-01

    The Chilean convergent plate boundary is one of the tectonically most active regions on earth and prone to large megathrust earthquakes as e. g. the 2010 Mw 8.8 Maule earthquake which ruptured a mature seismic gap in south-central Chile. In northern Chile historical data suggests the existence of a seismic gap between Arica and Mejillones Peninsula (MP), which has not ruptured since 1877. Further south, the 1995 Mw 8.0 Antofagasta earthquake ruptured the subduction interface between MP and Taltal. In this study we investigate the deformation at four active upper plate faults (dip-slip and strike-slip) located above the coupling zone of the subduction interface. The target faults (Mejillones Fault - MF, Salar del Carmen Fault - SCF, Cerro Fortuna Fault - CFF, Chomache Fault - CF) are situated in forearc segments, which are in different stages of the megathrust seismic cycle. The main question of this study is how strain is accumulated in the overriding plate, what is the response of the target faults to the megathrust seismic cycle and what are the mechanisms / processes involved. The hyper arid conditions of the Atacama desert and the extremely low erosion rates enable us to investigate geomorphic markers, e .g. fault scarps and knickpoints, which serve as a record for upper crustal deformation and fault activity about ten thousands years into the past. Fault scarp data has been acquired with Differential-GPS by measuring high-resolution topographic profiles perpendicular to the fault scarps and along incised gullies. The topographic data show clear variations between the target faults which possibly result from their position within the forearc. The surveyed faults, e. g. the SCF, exhibit clear along strike variations in the morphology of surface ruptures attributed to seismic events and can be subdivided into individual segments. The data allows us to distinguish single, composite and multiple fault scarps and thus to detect differences in fault growth initiated

  7. Hevea Leaves Boundary Identification based on Morphological Transformation and Edge Detection Features

    Directory of Open Access Journals (Sweden)

    Sule Tekkesinoglu

    2014-03-01

    Full Text Available The goal of this study is to present a concept to identify overlapping rubber tree (Hevea brasiliensis-scientific name leaf boundaries. Basically rubber tree leaves show similarity to each other and they may contain similar information such as color, texture or shape of leaves. In fact rubber tree leaves are naturally in class of palmate leaves, it means that numbers of leaves are joining at their base. So it reflects the information of the position of the leaves whether the leaves are overlapped or separated. Therefore, this unique feature could be used to distinguish particular leaves from others clone to identify the type of trees. This study addresses the problem of identifying the overlapped leaves with complex background. The morphological transformation is often applied in order to obtain the foreground object and the background location as well. However, it does not yield satisfactory results in order to get boundaries information. This study, presents on improved approach to identify boundary of rubber tree leaves based on morphological operation and edge detection methods. The outcome of this fused algorithm exhibits promising results for identifying the leaf boundaries of rubber trees.

  8. Recursion-transform method for computing resistance of the complex resistor network with three arbitrary boundaries.

    Science.gov (United States)

    Tan, Zhi-Zhong

    2015-05-01

    We develop a general recursion-transform (R-T) method for a two-dimensional resistor network with a zero resistor boundary. As applications of the R-T method, we consider a significant example to illuminate the usefulness for calculating resistance of a rectangular m×n resistor network with a null resistor and three arbitrary boundaries, a problem never solved before, since Green's function techniques and Laplacian matrix approaches are invalid in this case. Looking for the exact calculation of the resistance of a binary resistor network is important but difficult in the case of an arbitrary boundary since the boundary is like a wall or trap which affects the behavior of finite network. In this paper we obtain several general formulas of resistance between any two nodes in a nonregular m×n resistor network in both finite and infinite cases. In particular, 12 special cases are given by reducing one of the general formulas to understand its applications and meanings, and an integral identity is found when we compare the equivalent resistance of two different structures of the same problem in a resistor network.

  9. Induction motor broken rotor bar fault location detection through envelope analysis of start-up current using Hilbert transform

    Science.gov (United States)

    Abd-el-Malek, Mina; Abdelsalam, Ahmed K.; Hassan, Ola E.

    2017-09-01

    Robustness, low running cost and reduced maintenance lead Induction Motors (IMs) to pioneerly penetrate the industrial drive system fields. Broken rotor bars (BRBs) can be considered as an important fault that needs to be early assessed to minimize the maintenance cost and labor time. The majority of recent BRBs' fault diagnostic techniques focus on differentiating between healthy and faulty rotor cage. In this paper, a new technique is proposed for detecting the location of the broken bar in the rotor. The proposed technique relies on monitoring certain statistical parameters estimated from the analysis of the start-up stator current envelope. The envelope of the signal is obtained using Hilbert Transformation (HT). The proposed technique offers non-invasive, fast computational and accurate location diagnostic process. Various simulation scenarios are presented that validate the effectiveness of the proposed technique.

  10. Seamless Integration of Global Dirichlet-to-Neumann Boundary Condition and Spectral Elements for Transformation Electromagnetics

    CERN Document Server

    Yang, Zhiguo; Rong, Zhijian; Wang, Bo; Zhang, Baile

    2015-01-01

    In this paper, we present an efficient spectral-element method (SEM) for solving general two-dimensional Helmholtz equations in anisotropic media, with particular applications in accurate simulation of polygonal invisibility cloaks, concentrators and circular rotators arisen from the field of transformation electromagnetics (TE). In practice, we adopt a transparent boundary condition (TBC) characterized by the Dirichlet-to-Neumann (DtN) map to reduce wave propagation in an unbounded domain to a bounded domain. We then introduce a semi-analytic technique to integrate the global TBC with local curvilinear elements seamlessly, which is accomplished by using a novel elemental mapping and analytic formulas for evaluating global Fourier coefficients on spectral-element grids exactly. From the perspective of TE, an invisibility cloak is devised by a singular coordinate transformation of Maxwell's equations that leads to anisotropic materials coating the cloaked region to render any object inside invisible to observe...

  11. Continuation, south of Oaxaca City (southern Mexico) of the Oaxaca-Juarez terrane boundary and of the Oaxaca Fault. Based in MT, gravity and magnetic studies

    Science.gov (United States)

    Campos-Enriquez, J. O.; Corbo, F.; Arzate-Flores, J.; Belmonte-Jimenez, S.; Arango-Galván, C.

    2010-12-01

    The Oaxaca Fault represents Tertiary extensional reactivation of the Juarez shear zone constituting the boundary-suture between the Oaxaca and Juarez terranes (southern Mexico). South of Oaxaca City, the fault trace disappears and there are not clear evidences for its southward continuation at depth. The crust in southern México has been studied through seismic refraction, and seismological and magnetotelluric (MT) studies. The refraction studies did not image the Oaxaca Fault. However, previous regional MT studies suggest that the Oaxaca-Juarez terrane boundary lies to the east of the Zaachila and Mitla sub-basins, which implies sinistral displacement along the Donaji Fault. Campos-Enriquez et al. (2009) established the shallow structure of the Oaxaca-Juarez terrane boundary based in detailed gravity and magnetic studies. This study enabled: 1) to establish the shallow structure of the composite depression comprising three N-S sub-basins: the northern Etla and southern Zaachila sub-basins separated by the Atzompa sub-basin. According to the Oaxaca-Juarez terrane boundary is displaced sinistrally ca. 20 km along the E-W Donají Fault, which defines the northern boundary of the Zaachila sub-basin. At the same time,, the Oaxaca Fault may either continue unbroken southwards along the western margin of a horst in the Zaachila sub-basin or be offset along with the terrane boundary. This model implies that originally the suture was continuous south of the Donaji Fault. A constraint for the accreation of the Oaxaca and Juarez terranes. Thirty MT soundings were done in the area of the Central Valleys, Oaxaca City (southern Mexico). In particular we wanted to image the possible southward continuation of the Oaxaca Fault. 22 Mt sounding are located along two NE-SW profiles to the northern and to the south of the City of Oaxaca. To the north of Oaxaca City, the electrical resistivity distribution obtained show a clear discontinuity across the superficial trace of the Oaxaca

  12. Traditional transformations and transmedial affirmations: Blurring the boundaries of Sherlockian fan practices

    Directory of Open Access Journals (Sweden)

    Ashley D. Polasek

    2017-03-01

    Full Text Available The modes of discourse employed by fans of Sherlock Holmes represent both affirmational and transformational impulses. As the fan community has grown and diversified, tensions have arisen between Sherlockians who prefer to utilize traditional frameworks dating back to the early practices of the Baker Street Irregulars in the 1930s and '40s and those who operate primarily in virtual spaces and utilize 21st-century digital platforms as frameworks for their discourse. Because the demographics of affirmational fans tend to align with those of fans preferring traditional frameworks, and conversely, the demographics of transformational fans tend to align with those of fans preferring transmedial frameworks, the styles of engagement often become conflated with the impulses driving the discourse itself. By first examining these tensions and then utilizing case studies that illustrate the four combinations of frameworks and modes of discourse—traditional-affirmational, transmedial-affirmational, traditional-transformational, and transmedial-transformational—I seek to complicate the boundaries that appear to divide the larger Sherlock Holmes fan community. I will demonstrate that the twin fannish impulses to affirm the text and transform it have operated not at odds but in parallel throughout the history of the fandom.

  13. Refined Views of Strike-slip Fault Zones, Seismicity, and State of Stress Associated With the Pacific-North America Plate Boundary in Southern California

    Science.gov (United States)

    Hauksson, E.; Nicholson, C.; Shaw, J. H.; Plesch, A.; Shearer, P. M.; Sandwell, D. T.; Yang, W.

    2013-12-01

    The mostly strike-slip plate boundary in southern California is expressed as a system of late Quaternary faults or principal slip zones (PSZs), with numerous adjacent smaller slip surfaces. It is complex, even after large cumulative displacements, and consists of major fault systems with multi-stranded, non-planar fault geometry, including some in close proximity to each other. There are also secondary cross faults and low-angle detachments that interact with the PSZs accommodating main plate boundary motion. The loading of plate-tectonic strain causes the largest earthquakes along PSZs, moderate-sized events in their immediate vicinity, and small earthquakes across the whole region. We apply relocated earthquake and refined focal mechanism (1981-2013) catalogs, as well as other geophysical datasets to provide refined views of the 3D fault geometry of these active fault systems. To determine properties of individual fault zones, we measure the Euclidian distance from every hypocenter to the nearest PSZ. In addition, we assign crustal geophysical parameters such as heat flow value and shear or dilatation strain rates to each epicenter. We investigate seismogenic thickness and fault zone width as well as earthquake source processes. We find that the seismicity rate is a function of location, with the rate dying off exponentially with distance from the PSZ. About 80% of small earthquakes are located within 5 km of a PSZ. For small earthquakes, stress drops increase in size with distance away from the PSZs. The magnitude distribution near the PSZs suggests that large earthquakes are more common close to PSZs, and they are more likely to occur at greater depth than small earthquakes. In contrast, small quakes can occur at any geographical location. An optimal combination of heat flow and strain rate is required to concentrate the strain along rheologically weak fault zones, which accommodate the crustal deformation processes, causing seismicity. The regional trend of

  14. A NONLINEAR TRANSFORMATION AND A BOUNDARY-INITIAL VALUE PROBLEM FOR ACLASS OF NONLINEAR CONVECTION-DIFFUSION EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With the aid of a nonlinear transformation, a class of nonlinear convectiondiffusion PDE in one space dimension is converted into a linear one, the unique solution of a nonlinear boundary-initial value problem for the nonlinear PDE can be exactly expressed by the nonlinear transformation, and several illustrative examples are given

  15. Are quartz LPOs predictably oriented with respect to the shear zone boundary?: A test from the Alpine Fault mylonites, New Zealand

    Science.gov (United States)

    Little, Timothy A.; Prior, David J.; Toy, Virginia G.

    2016-03-01

    The Alpine fault self-exhumes its own ductile shear zone roots and has a known slip kinematics. Within ˜1 km of the fault, the mylonitic foliation is subparallel to the boundary of the amphibolite-facies ductile shear zone in which it formed. Using EBSD, we analyzed quartz Lattice Preferred Orientations [LPOs) of mylonites along a central part of the Alpine Fault. All LPOs feature a strongest girdle of [c]-axes that is forward-inclined ˜28 ± 4° away from the pole to the fault. A maximum of axes is inclined at the same angle relative the fault. The [c]-axis girdle is perpendicular to extensional (C') shear bands and the maximum is parallel to their slip direction. [c]-axis girdles do not form perpendicular to the SZB. Schmid factor analysis suggests that σ1 was arranged at 60-80° to the Alpine Fault. These observations indicate ductile transpression in the shear zone. The inclined arrangement of [c]-axis girdles, axes, and C' planes relative to the fault can be explained by their alignment relative to planes of maximum shear-strain-rate in a general shear zone, a significant new insight regarding shear zones and how LPO fabrics may generally develop within them. For the Alpine mylonite zone, our data imply a kinematic vorticity number (Wk) of ˜0.7 to ˜0.85. Inversions of seismic focal mechanisms in the brittle crust of the Southern Alps indicate that σ1 is oriented ˜60° to the Alpine Fault; that shear bands form at ˜30° to this direction, and that σ2 and σ3 flip positions between the brittle and ductile parts of the crust.

  16. Fault kinematics of the Magallanes-Fagnano fault system, southern Chile; an example of diffuse strain and sinistral transtension along a continental transform margin

    Science.gov (United States)

    Betka, Paul; Klepeis, Keith; Mosher, Sharon

    2016-04-01

    A system of left-lateral faults that separates the South American and Scotia plates, known as the Magallanes-Fagnano fault system, defines the modern tectonic setting of the southernmost Andes and is superimposed on the Late Cretaceous - Paleogene Patagonian fold-thrust belt. Fault kinematic data and crosscutting relationships from populations of thrust, strike-slip and normal faults from Peninsula Brunswick adjacent to the Magallanes-Fagnano fault system, presented herein, show kinematic and temporal relationships between thrust faults and sets of younger strike-slip and normal faults. Thrust fault kinematics are homogeneous in the study area and record subhorizontal northeast-directed shortening. Strike-slip faults record east-northeast-directed horizontal shortening, west-northwest-directed horizontal extension and form Riedel and P-shear geometries compatible with left-lateral slip on the main splay of the Magallanes-Fagnano fault system. Normal faults record north-south trending extension that is compatible with the strike-slip faults. The study area occurs in a releasing step-over between overlapping segments of the Magallanes-Fagnano fault system, which localized on antecedent sutures between basement terranes with differing geological origin. Results are consistent with regional tectonic models that suggest sinistral shearing and transtension in the southernmost Andes was contemporaneous with the onset of seafloor spreading in the Western Scotia Sea during the Early Miocene.

  17. An integral-free expression for short-term changes in fault stability due to pore pressure induced when a point load is placed on the pervious boundary of a porous elastic half space containing a fault

    Indian Academy of Sciences (India)

    Ramesh Chander; S K Tomar

    2014-10-01

    A concentrated load with step-function time behaviour is placed normal to the planar, pervious boundary of a porous elastic half space (PEHS) with compressible constituents. A planar fault exists in the PEHS in such a way that the poroelastic behaviour of the medium is unhindered. We derive an approximate but integral-free expression for CFSCPP, i.e., changes in fault stability due to changes in pore pressure, at a point not too far off the line along which the load acts. But, in the interest of simplicity, the main discussion is focussed on a consideration of CFSCPP at a point located on the fault at depth directly beneath the load. It is convenient to introduce dimensionless time directly proportional to real time . The constant of proportionality is 4c/z2, where is hydraulic diffusivity. The derived approximate expression gives results with an accuracy of greater than 99% for limited values of after the load is imposed. We learn from the derived expression that, for a given , fault stability undergoes an initial sudden decrease commensurate with the undrained pore pressure induced in the PEHS. This is followed by a more gradual decrease in fault stability with increasing until a minimum is reached. The real time to minimum fault stability increases with . The magnitude of CFSCPP decreases with as −2 for a given in the permissible range. The derived expression and the inferences based on it should be useful during earth science investigations of the possible hazards due to reactivation of a pre-existing shallow fault when a civil engineering project involving imposition of a heavy load on the earth’s surface is to be executed nearby. They should be useful also for investigations if a shallow earthquake occurs near such a project soon after its execution.

  18. Second mode unstable disturbance measurement of hypersonic boundary layer on cone by wavelet transform

    Institute of Scientific and Technical Information of China (English)

    Jian Han; Nan Jiang; Yan Tian

    2011-01-01

    Experimental investigation of hypersonic boundary layer instability on a cone is performed at Mach number 6 in a hypersonic wind tunnel. Time series signals of instantaneous fluctuating surface-thermal-flux are measured by Pt-thin-film thermocouple temperature sensors mounted at 28 stations on the cone surface in the streamwise direction to investigate the development of the unstable disturbance.Wavelet transform is employed as a mathematical tool to obtain the multi-scale characteristics of fluctuating surfacethermal-flux both in the temporal and spectrum space. The conditional sampling algorithm using wavelet coefficient as an index is put forward to extract the unstable disturbance waveform from the fluctuating surface-thermal-flux signals.The generic waveform for the second mode unstable disturbance is obtained by a phase-averaging technique. The development of the unstable disturbance in the streamwise direction is assessed both in the temporal and spectrum space.Our study shows that the local unstable disturbance detection method based on wavelet transformation offers an alternative powerful tool in studying the hypersonic unstable mode of laminar-turbulent transition. It is demonstrated that, at hypersonic speeds, the dominant flow instability is the second mode, which governs the course of laminar-turbulent transition of sharp cone boundary layer.

  19. Transformation of aerosol in Planetary Boundary Layer over the Baltic Sea

    Science.gov (United States)

    Makuch, Przemyslaw; Petelski, Tomasz; Piskozub, Jacek; Jankowski, Andrzej; Zieliński, Tymon; Rozwadowska, Anna; Markuszewski, Piotr; Zawadzka, Olga

    2013-04-01

    Aerosols are one of the most important components of the atmosphere. The content and composition of aerosols in the atmosphere depends on their origin. In maritime areas transformation of aerosols in the atmosphere may occur. This depends on many factors, such as wind speed and direction, humidity and emission from the sea surface. The transformation of aerosols in the Planetary Boundary Layer over the Baltic Sea is replacing other sources of aerosols to aerosols composed of sea salt. When the air passing over the Baltic aerosol optical thickness (AOT) initially decreases and then increases in strong winds due to increase of the marine aerosol content in the layer. This type of change can be followed with use of many numerical experiments performed on the model of the transformation of aerosols in the Planetary Boundary Layer. This model consists of two parts, dynamic and optical. The dynamic part is based on the repeated numerical solution of the equation of diffusion for different particle size and optical properties. The result of the dynamic part provides vertical profiles of aerosol size distributions. Optical module to calculate the relative cross sections for the weakening used Mie single process. We compare data from numerical experiments with data from in situ experiments and with data from MODIS (Moderate Resolution Imaging Spectroradiometer) on board of Terra and Aqua satellite. From the resulting comparisons received correlations are in order as 0.789 and 0.862. What indicates a good correlation between the data from numerical experiment and in situ data or MODIS data. Acknowledgements: The support for this study was provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBałtyk founded by European Union through European Regional Development Fund contract No. POIG 01.01.02-22-011/09

  20. Acoustic emission partial discharge detection technique applied to fault diagnosis: Case studies of generator transformers

    Directory of Open Access Journals (Sweden)

    Shanker Tangella Bhavani

    2016-01-01

    Full Text Available In power transformers, locating the partial discharge (PD source is as important as identifying it. Acoustic Emission (AE sensing offers a good solution for both PD detection and PD source location identification. In this paper the principle of the AE technique, along with in-situ findings of the online acoustic emission signals captured from partial discharges on a number of Generator Transformers (GT, is discussed. Of the two cases discussed, the first deals with Acoustic Emission Partial Discharge (AEPD tests on two identical transformers, and the second deals with the AEPD measurement of a transformer carried out on different occasions (years. These transformers are from a hydropower station and a thermal power station in India. Tests conducted in identical transformers give the provision for comparing AE signal amplitudes from the two transformers. These case studies also help in comprehending the efficacy of integrating Dissolved Gas is (DGA data with AEPD test results in detecting and locating the PD source.

  1. Rough set and radial basis function neural network based insulation data mining fault diagnosis for power transformer

    Institute of Scientific and Technical Information of China (English)

    DONG Li-xin; XIAO Deng-ming Xiao; LIU Yi-lu

    2007-01-01

    Rough set (RS) and radial basis function neural network (RBFNN) based insulation data mining fault diagnosis for power transformer is proposed. On the one hand rough set is used as front of RBFNN to simplify the input of RBFNN and mine the rules. The mined rules whose "confidence" and "support" is higher than requirement are used to offer fault diagnosis service for power transformer directly. On the other hand the mining samples corresponding to the mined rule, whose "confidence and support" is lower than requirement,are used to be training samples set of RBFNN and these samples are clustered by rough set. The center of each clustering set is used to be center of radial basis function, i.e. , as the hidden layer neuron. The RBFNN is structured with above base, which is used to diagnose the case that can not be diagnosed by mined simplified valuable rules based on rough set. The advantages and effectiveness of this method are verified by testing.

  2. A robust algorithm based on a failure-sensitive matrix for fault diagnosis of power systems: an application on power transformers

    OpenAIRE

    2015-01-01

    In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transforme...

  3. Tectonic isolation of the Levant basin offshore Galilee-Lebanon effects of the Dead Sea fault plate boundary on the Levant continental margin, eastern Mediterranean

    Science.gov (United States)

    Schattner, U.; Ben-Avraham, Z.; Lazar, M.; Hüebscher, C.

    2006-11-01

    The continental margin of the central Levant, offshore northern Israel and southern Lebanon is characterized by a sharp continental-oceanic crustal transition, exhibited on the bathymetry as a steep continental slope. At the base of the slope a narrow zone of faulting deforms the upper Messinian-recent sedimentary sequence. Further into the basin no major deformations are observed. However, onland a restraining bend along the Dead Sea fault plate boundary results in the formation of the Lebanon and anti-Lebanon mountain ranges, which exhibit a large positive isostatic anomaly not compensated at depth. All these geologic features follow a NNE-SSW trend. A dense network of multi-channel and single-channel seismic profiles, covering 5000 km of ship-track offshore northern Israel and southern Lebanon, was analyzed for the purpose of characterizing the continental margin. Additional seismic surveys covering the area between the Levant margin and the Cyprean arc were examined. Data were then incorporated with magnetic, gravity and earthquake measurements to reveal the deep crustal structure of the area and integrated with bathymetry data to describe the behavior of the young sedimentary basin fill. Results indicate that the Levant basin, offshore northern Israel and southern Lebanon (up to Beirut) is more-or-less unaffected by the intense tectonic deformation occurring onland. The transition between the deformed area onland and the undeformed Levant basin occurs along the base of the continental slope. Along the base, the upper Messinian-recent sedimentary sequence is cut by two sets of faults: shallow growth faults resulting from salt tectonics and high angle faults, marking the surface expression of a deeper crustal discontinuity - the marine extension of the Carmel fault zone. The central Levant continental margin is being reactivated by transpressional faulting of the marine continuation of the Carmel fault, at the base of the continental slope. This fault system

  4. Periodic Boundary Conditions for Finite-Differentiation-Method Fast-Fourier-Transform Micromagnetics

    Institute of Scientific and Technical Information of China (English)

    Jiang-Nan Li; Dan Wei

    2017-01-01

    We describe an accurate periodic boundary condition (PBC) called the symmetric PBC in the calculation of the magnetostatic interaction field in the finite-differentiation-method fast-Fourier-transform (FDM-FFT) micromagnetics.The micromagnetic cells in the regular mesh used by the FDM-FFT method are finite-sized elements,but not geometrical points.Therefore,the key PBC operations for FDM-FFT methods are splitting and relocating the micromagnetic cell surfaces to stay symmetrically inside the box of half-total sizes with respect to the origin.The properties of the demagnetizing matrix of the split micromagnetic cells are discussed,and the sum rules of demagnetizing matrix are fulfilled by the symmetric PBC.

  5. Solving Heat Conduction Problems in Movable Boundary Domains under Intensive Physical-Chemical Transformation Conditions

    Directory of Open Access Journals (Sweden)

    Garashchenko A.N.

    2016-01-01

    Full Text Available Results of solving problems of simulating temperature fields in domains with movable boundaries of characteristic zones of intensive physical-chemical and thermomechanical transformations to be realized in materials upon high-temperature heating have been presented. Intumescent fire-protective coatings based on organic and mineral materials are the object of study. Features of numerical realization of input equation systems taking into account, in particular, a dynamics of considerable increase and subsequent decrease of the intumescent layer thickness have been considered. Example calculations for structures of metal and wood protected with various coatings are given. Results of calculating two-dimensional temperature fields in polymer composite square-shaped structures with internal cruciform load-bearing elements have been presented. The intumescent coating is arranged on the external surface of a structure. The solution of the above-listed problems is of important significance to provide fire protection of different-purpose structures and products.

  6. Surface layer similarity in the nocturnal boundary layer: the application of Hilbert-Huang transform

    Directory of Open Access Journals (Sweden)

    J. Hong

    2009-10-01

    Full Text Available Turbulence statistics such as flux-variance relationship is critical information in measuring and modeling carbon, water, energy, and momentum exchanges at the biosphere-atmosphere interface. Using a recently proposed mathematical technique, the Hilbert-Huang transform (HHT, this study highlights its possibility to quantify impacts of non-turbulent flows on turbulence statistics in the stable surface layer. The HHT is suitable for the analysis of non-stationary and intermittent data and thus very useful for better understanding of the interplay of the surface layer similarity with complex nocturnal environment. Our analysis showed that the HHT can successfully sift non-turbulent components and be used as a tool to estimate the relationships between turbulence statistics and atmospheric stability in complex environment such as nocturnal stable boundary layer.

  7. Surface layer similarity in the nocturnal boundary layer: the application of Hilbert-Huang transform

    Directory of Open Access Journals (Sweden)

    J. Hong

    2010-04-01

    Full Text Available Turbulence statistics such as flux-variance relationship are critical information in measuring and modeling ecosystem exchanges of carbon, water, energy, and momentum at the biosphere-atmosphere interface. Using a recently proposed mathematical technique, the Hilbert-Huang transform (HHT, this study highlights its possibility to quantify impacts of non-turbulent flows on turbulence statistics in the stable surface layer. The HHT is suitable for the analysis of non-stationary and intermittent data and thus very useful for better understanding the interplay of the surface layer similarity with complex nocturnal environment. Our analysis showed that the HHT can successfully sift non-turbulent components and be used as a tool to estimate the relationships between turbulence statistics and atmospheric stability in complex environments such as nocturnal stable boundary layer.

  8. Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System

    Science.gov (United States)

    Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal

    2017-10-01

    Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

  9. Transformation and Deposition of Sulphur and Nitrogen Compounds in the Marine Boundary Layer

    Energy Technology Data Exchange (ETDEWEB)

    Hertel, O.

    1995-10-01

    In this thesis the author performs a model study of the transformation and deposition of sulphur and nitrogen compounds in the marine boundary layer, including source-receptor relationships. The central part of the study is the development and testing of a variable scale trajectory model for Europe, with special emphasis on modelling the concentrations of gases and aerosols in the marine atmosphere and the deposition to sea. A one-dimensional version of the model was developed to model the chemical degradation of dimethyl sulphide (DMS) in the marine boundary layer. Although the model reproduces the observed levels of DMS and methane sulphonic acid (MSA) well, the calculated DMS concentration is not always in phase with observed levels, probably because of a local coastal emission that is correlated with the shifting tide. Another version of the trajectory model, Atmospheric Chemistry and Deposition model (ACDEP), was developed to study the deposition of nitrogen compounds to the Danish sea waters. This model uses a new numerical scheme, the Eulerian Backward Iterative method. The model is able to reproduce observations of air concentrations and wet deposition fairly well; data for dry deposition were not available. The model was also used for calculation of deposition of nitrogen compounds to the Kattegat. Finally, a sensitivity study was performed on the model. 175 refs., 87 figs., 32 tabs.

  10. Comprehensive two-dimensional river ice model based on boundary-fitted coordinate transformation method

    Directory of Open Access Journals (Sweden)

    Ze-yu MAO

    2014-01-01

    Full Text Available River ice is a natural phenomenon in cold regions, influenced by meteorology, geomorphology, and hydraulic conditions. River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes, and they are also influenced by weather and hydrologic conditions. Because natural rivers are serpentine, with bends, narrows, and straight reaches, the commonly-used one-dimensional river ice models and two-dimensional models based on the rectangular Cartesian coordinates are incapable of simulating the physical phenomena accurately. In order to accurately simulate the complicated river geometry and overcome the difficulties of numerical simulation resulting from both complex boundaries and differences between length and width scales, a two-dimensional river ice numerical model based on a boundary-fitted coordinate transformation method was developed. The presented model considers the influence of the frazil ice accumulation under ice cover and the shape of the leading edge of ice cover during the freezing process. The model is capable of determining the velocity field, the distribution of water temperature, the concentration distribution of frazil ice, the transport of floating ice, the progression, stability, and thawing of ice cover, and the transport, accumulation, and erosion of ice under ice cover. A MacCormack scheme was used to solve the equations numerically. The model was validated with field observations from the Hequ Reach of the Yellow River. Comparison of simulation results with field data indicates that the model is capable of simulating the river ice process with high accuracy.

  11. Detection of intermittent resistive faults in electronic systems based on the mixed-signal boundary-scan standard

    NARCIS (Netherlands)

    Kerkhoff, Hans G.; Ebrahimi, Hassan

    2015-01-01

    In avionics, like glide computers, the problem of No Faults Found (NFF) is a very serious and extremely costly affair. The rare occurrences and short bursts of these faults are the most difficult ones to detect and diagnose in the testing arena. Several techniques are now being developed in ICs by u

  12. Power transformer fault diagnosis model based on rough set theory with fuzzy representation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Inthis paper,rough-fuzzy hybridizationis usedfor synthetic fault diagnosis of power transfor mers.Each diagnostic method s result is represented by itsfuzzy membership with respect to three credible de-gree sets as:Low,Middle,orHigh,thereby gen-erating a fuzzy granulation of the feature space thatcontains granules with otherwiseill-defined bounda-ries.Discernibility of the granulated objects inter ms of attributes is thencomputedinthe for mof adiscernibility matrix.Using rough set theory,anumber of decision...

  13. Detection of weak transient signals based on wavelet packet transform and manifold learning for rolling element bearing fault diagnosis

    Science.gov (United States)

    Wang, Yi; Xu, Guanghua; Liang, Lin; Jiang, Kuosheng

    2015-03-01

    The kurtogram-based methods have been proved powerful and practical to detect and characterize transient components in a signal. The basic idea of the kurtogram-based methods is to use the kurtosis as a measure to discover the presence of transient impulse components and to indicate the frequency band where these occur. However, the performance of the kurtogram-based methods is poor due to the low signal-to-noise ratio. As the weak transient signal with a wide spread frequency band can be easily masked by noise. Besides, selecting signal just in one frequency band will leave out some transient features. Aiming at these shortcomings, different frequency bands signal fusion is adopted in this paper. Considering that manifold learning aims at discovering the nonlinear intrinsic structure which embedded in high dimensional data, this paper proposes a waveform feature manifold (WFM) method to extract the weak signature from waveform feature space which obtained by binary wavelet packet transform. Minimum permutation entropy is used to select the optimal parameter in a manifold learning algorithm. A simulated bearing fault signal and two real bearing fault signals are used to validate the improved performance of the proposed method through the comparison with the kurtogram-based methods. The results show that the proposed method outperforms the kurtogram-based methods and is effective in weak signature extraction.

  14. An improved fault detection classification and location scheme based on wavelet transform and artificial neural network for six phase transmission line using single end data only.

    Science.gov (United States)

    Koley, Ebha; Verma, Khushaboo; Ghosh, Subhojit

    2015-01-01

    Restrictions on right of way and increasing power demand has boosted development of six phase transmission. It offers a viable alternative for transmitting more power, without major modification in existing structure of three phase double circuit transmission system. Inspite of the advantages, low acceptance of six phase system is attributed to the unavailability of a proper protection scheme. The complexity arising from large number of possible faults in six phase lines makes the protection quite challenging. The proposed work presents a hybrid wavelet transform and modular artificial neural network based fault detector, classifier and locator for six phase lines using single end data only. The standard deviation of the approximate coefficients of voltage and current signals obtained using discrete wavelet transform are applied as input to the modular artificial neural network for fault classification and location. The proposed scheme has been tested for all 120 types of shunt faults with variation in location, fault resistance, fault inception angles. The variation in power system parameters viz. short circuit capacity of the source and its X/R ratio, voltage, frequency and CT saturation has also been investigated. The result confirms the effectiveness and reliability of the proposed protection scheme which makes it ideal for real time implementation.

  15. Metamorphism, argon depletion, heat flow and stress on the Alpine fault

    Science.gov (United States)

    Scholz, C. H.; Beavan, J.; Hanks, T. C.

    1978-01-01

    The Alpine fault of New Zealand is a major continental transform fault which was uplifted on its southeast side 4 to 11 km within the last 5 m.y. This uplift has exposed the Haast schists, which were metamorphosed from the adjacent Torlesse graywackes. The Haast schists increase in metamorphic grade from prehnite-pumpellyite facies 9-12 km from the fault through the chlorite and biotite zones of the greenschist facies to the garnet-oligoclase zone amphibolite facies within 4 km of the fault. These metamorphic zone boundaries are subparallel to the fault for 350 km along the strike. The K-Ar and Rb-Sr ages of the schists increase with distance from the fault: from 4 m.y. within 3 km of the fault to approximately 110 m.y. 20 km from the fault. Field relations show that the source of heat that produced the argon depletion aureole was the fault itself.

  16. The EarthScope Plate Boundary Observatory (PBO) Facility: Innovations, Transformations, and Impact

    Science.gov (United States)

    Jackson, M. E.; Mencin, D.; Feaux, K.

    2013-12-01

    The word 'transformation' is not used lightly in science. However, the transformative nature of the EarthScope Plate Boundary Observatory facility on the science community is large and measurable. The impact of the creation, execution and delivery of the PBO resulted in radical changes in the way the geodesy community views permanent, continuously operating (and often) real-time GPS and strain networks, open data policies, and the ability for consortium based facilities, such as UNAVCO, to manage and deliver on large National Science Foundation investments. Our presentation will explore these innovations and transformations from the community, facility, and science perspectives. In the genesis of the EarthScope proposal there was a distinct shift away from the PBO being managed and constructed by prominent PI's within the community to a vesting of the responsibility and authority in UNAVCO to execute on behalf of the entire community. This tipping away from individual PI concerns towards a communal behavior allowed the construction of a facility based on broad input from, and equal access for, any member of the geodesy community. The open and transparent nature of EarthScope, including the open data policy for both facility and PI derived data was truly transformative. One of the key tenants of the PBO was strict adherence to not redesigning unless absolutely necessary. For example PBO monumentation and data processing practices were adopted wholesale from the SCIGN project, while the station selection, project management, permitting practices, data downloading, metadata, and, data communications were refactored for optimum use for the broader geodesy community and to scale with the large geography that confronted PBO. The PBO strainmeter network, one of the largest in the world, started by looking at the procedures of 30 years of heterogeneous installations around the word then crafted, created, and amalgamated new drilling, grouting, installation, and data

  17. The San Andreas fault in the San Francisco Bay region, California: Structure and kinematics of a Young plate boundary

    Science.gov (United States)

    Jachens, R.C.; Zoback, M.L.

    1999-01-01

    Recently acquired high-resolution aeromagnetic data delineate offset and/or truncated magnetic rock bodies of the Franciscan Complex that define the location and structure of, and total offset across, the San Andreas fault in the San Francisco Bay region. Two distinctive magnetic anomalies caused by ultramafic rocks and metabasalts east of, and truncated at, the San Andreas fault have clear counterparts west of the fault that indicate a total right-lateral offset of only 22 km on the Peninsula segment, the active strand that ruptured in 1906. The location of the Peninsula segment is well defined magnetically on the northern peninsula where it goes offshore, and can be traced along strike an additional ~6 km to the northwest. Just offshore from Lake Merced, the inferred fault trace steps right (northeast) 3 km onto a nearly parallel strand that can be traced magnetically northwest more than 20 km as the linear northeast edge of a magnetic block bounded by the San Andreas fault, the Pilarcitos fault, and the San Gregorio-Hosgri fault zone. This right-stepping strand, the Golden Gate segment, joins the eastern mapped trace of the San Andreas fault at Bolinas Lagoon and projects back onshore to the southeast near Lake Merced. Inversion of detailed gravity data on the San Francisco Peninsula reveals a 3 km wide basin situated between the two strands of the San Andreas fault, floored by Franciscan basement and filled with Plio-Quaternary sedimentary deposits of the Merced and Colma formations. The basin, ~1 km deep at the coast, narrows and becomes thinner to the southeast along the fault over a distance of ~12 km. The length, width, and location of the basin between the two strands are consistent with a pull-apart basin formed behind the right step in the right-lateral strike-slip San Andreas fault system and currently moving southeast with the North American plate. Slight nonparallelism of the two strands bounding the basin (implying a small component of convergence

  18. An Improvement of the Differential Transformation Method and Its Application for Boundary Layer Flow of a Nanofluid

    Directory of Open Access Journals (Sweden)

    Abdelhalim Ebaid

    2013-01-01

    Full Text Available The main feature of the boundary layer flow problems of nanofluids or classical fluids is the inclusion of the boundary conditions at infinity. Such boundary conditions cause difficulties for any of the series methods when applied to solve such a kind of problems. In order to solve these difficulties, the authors usually resort to either Padé approximants or the commercial numerical codes. However, an intensive work is needed to perform the calculations using Padé technique. Due to the importance of the nanofluids flow as a growing field of research and the difficulties caused by using Padé approximants to solve such problems, a suggestion is proposed in this paper to map the semi-infinite domain into a finite one by the help of a transformation. Accordingly, the differential equations governing the fluid flow are transformed into singular differential equations with classical boundary conditions which can be directly solved by using the differential transformation method. The numerical results obtained by using the proposed technique are compared with the available exact solutions, where excellent accuracy is found. The main advantage of the present technique is the complete avoidance of using Padé approximants to treat the infinity boundary conditions.

  19. Transformer Protection by Using FL Based Artificial Intelligent Buchholz Relay against Incipient Faults

    Directory of Open Access Journals (Sweden)

    SOUMYADEEP SAMONTO

    2016-03-01

    Full Text Available Switchgear and Protection are the two vital terminology of Electrical power system. Normally the components of any switchgear needs better protection schemes to be set for a composite power system. Many explorers worked on artificial intelligent breaker but an indulgence of fuzzy theory is nevertheless very absent in case of buchholz relay. Here in this paper discussion has been drawn in favor of the Artificial Intelligent Buchholz (AIB relay where inputs are level of transformer oil and rate of oil rising due to over current. To fit with the transformer tank it is needed to measure level of transformer oil and the rate at which volume increasing. The constructional feature of a rate of rise pressure relay is taken into account in this work along with the working principle of a buchholz relay. The change in the inputs will give a crisp output to change the contacts state from normally closed to normally open by tripping via alarm circuit indeed like the basic buchholz relay does. The entire concept has been developed under MATLAB environment using Mamdani based Fuzzy Inference System. Experimental output data validates the implementation of Transformer Protection by Using Fuzzy Logic Based Artificial Intelligent Buchholz Relay.

  20. An integral transform approach for a mixed boundary problem involving a flowing partially penetrating well with infinitesimal well skin

    Science.gov (United States)

    Chang, Chien-Chieh; Chen, Chia-Shyun

    2002-06-01

    A flowing partially penetrating well with infinitesimal well skin is a mixed boundary because a Cauchy condition is prescribed along the screen length and a Neumann condition of no flux is stipulated over the remaining unscreened part. An analytical approach based on the integral transform technique is developed to determine the Laplace domain solution for such a mixed boundary problem in a confined aquifer of finite thickness. First, the mixed boundary is changed into a homogeneous Neumann boundary by substituting the Cauchy condition with a Neumann condition in terms of well bore flux that varies along the screen length and is time dependent. Despite the well bore flux being unknown a priori, the modified model containing this homogeneous Neumann boundary can be solved with the Laplace and the finite Fourier cosine transforms. To determine well bore flux, screen length is discretized into a finite number of segments, to which the Cauchy condition is reinstated. This reinstatement also restores the relation between the original model and the solutions obtained. For a given time, the numerical inversion of the Laplace domain solution yields the drawdown distributions, well bore flux, and the well discharge. This analytical approach provides an alternative for dealing with the mixed boundary problems, especially when aquifer thickness is assumed to be finite.

  1. Pd-Doped SnO2-Based Sensor Detecting Characteristic Fault Hydrocarbon Gases in Transformer Oil

    Directory of Open Access Journals (Sweden)

    Weigen Chen

    2013-01-01

    Full Text Available Methane (CH4, ethane (C2H6, ethylene (C2H4, and acetylene (C2C2 are important fault characteristic hydrocarbon gases dissolved in power transformer oil. Online monitoring these gaseous components and their generation rates can present the operational state of power transformer timely and effectively. Gas sensing technology is the most sticky and tricky point in online monitoring system. In this paper, pure and Pd-doped SnO2 nanoparticles were synthesized by hydrothermal method and characterized by X-ray powder diffraction, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The gas sensors were fabricated by side-heated preparation, and their gas sensing properties against CH4, C2H6, C2H4, and C2H2 were measured. Pd doping increases the electric conductance of the prepared SnO2 sensors and improves their gas sensing performances to hydrocarbon gases. In addition based on the frontier molecular orbital theory, the highest occupied molecular orbital energy and the lowest unoccupied molecular orbital energy were calculated. Calculation results demonstrate that C2H4 has the highest occupied molecular orbital energy among CH4, C2H6, C2H4, and C2H2, which promotes charge transfer in gas sensing process, and SnO2 surfaces capture a relatively larger amount of electric charge from adsorbed C2H4.

  2. Grain boundary transformations during isothermal exposure of powder metallurgy nickel base superalloys for turbine disc applications

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.J.; Rae, C.M.F.; Tin, S.

    2005-01-15

    Nickel base superalloys are used for high pressure turbine discs, because they are capable of sustained operation under high mechanical loading at elevated temperatures. In service, turbine discs operate at high temperatures (approaching 700 deg C at the disc rim), which can lead to various microstructural changes and influence the resulting structural integrity of the component. In the alloys studied in the present work, the development of the topologically close packed phase (TCP) {sigma} has been characterised for various time and temperature combinations. The formation of {sigma} is particularly important for these alloys, as it is known to have a dramatic effect on fatigue crack growth owing to grain boundary embrittlement. In the present study, various techniques have been used to quantify the amount of {sigma} phase present for given times and temperatures, similar to those seen during operation. Both qualitative microscopy and quantitative X-ray diffraction have been conducted to establish the time-temperature-transformation relationship for {sigma} formation in two experimental turbine disc alloys. Both of the alloys studied here exhibit a low susceptibility to {sigma} formation compared with conventional alloys such as Udimet 720Li and RR1000. (Author)

  3. Constraining the shear zone along the Dead Sea transform fault in the crust and upper mantle using seismic anisotropy

    Science.gov (United States)

    Kaviani, Ayoub; Rümpker, Georg; Asch, Günter; Desire Group

    2010-05-01

    We study seismic anisotropy along the Dead Sea Transform fault (DST) by shear-wave splitting analysis of SKS and SKKS waveforms recorded at a dense network of broad-band and short-period stations of the DESIRE experiment. The DST accommodates the relative motion between Africa and Arabia through a sinistral strike-slip motion. The Dead Sea is a pull-apart basin formed along the DST as a result of stepwise fault-normal displacement. The DESIRE array of stations cover this portion of the DST. We measured the splitting parameters (delay times between the fast and slow components of the shear wave and fast polarization direction) in different period bands. We observed consistent fast polarization directions varying from N14W to N19E at different stations and delay times ranging between 1.0 and 2.5 s. Our preliminary examination reveals that the splitting parameters do not exhibit significant frequency dependence. However, we observe variations in the splitting parameters (mostly delay times) along an E-W profile crossing the DST, with smaller delay times in the middle of the profile, within the surface exposure of the DST shear zone, and with two lobes of relatively large delay times on both sides of the central region. The fast polarization directions along this profile change from a dominant NNW trend in the western side of the DST to a general N-S orientation in the central part and a dominant NNE trend to the east. Waveform modeling is required to infer the lateral and depth variations of the strength and orientation of anisotropy in the crust and upper mantle from these observations. We will also complement our results with the data from the DESERT experiment to provide an overall pattern of seismic anisotropy and structural fabric beneath the DST and surrounding regions from the north of the Dead Sea down to the Red sea.

  4. Effect of strain-weakening on Oligocene-Miocene self-organization of the Australian-Pacific plate boundary fault in southern New Zealand: Insights from numerical modelling

    Science.gov (United States)

    Feng, Xiaojun; Jessell, Mark Walter; Amponsah, Prince Ofori; Martin, Roland; Ganne, Jérôme; Liu, Daqing; Batt, Geoffrey E.

    2016-10-01

    Tectonic inheritance acquired from past geological events can control the formation of new plate boundaries. The aim of this paper is to explore the role of inherited NE and NW trending fabrics and their rheological influence on the propagation of Oligocene-Miocene strike-slip faulting that matured to become the Australian-Pacific plate boundary fault in southern New Zealand. Strain weakening plays a significant role in controlling the formation, growth and evolution of strain localization. In this study, three-dimensional thermo-mechanical models have been used to explore the effect of strain weakening on the Oligocene-Miocene self-organization of strain localization. Strain weakening is simulated through decreasing either the coefficient of friction of upper crust, its cohesion, or the rheological viscosity contrast between the inherited structures and their surrounding wall rocks. Viscosity contrast is obtained by varying the viscosity of inherited structures. Softening coefficient (α) is a measure of strain weakening. Our experiments robustly demonstrate that a primary boundary shear zone becomes mature quicker when softening coefficients are increased. Deformation is focused along narrow high-strain shear zones in the centre of the model when the softening coefficients are high, whereas the strain is more diffuse with many shear zones spread over the model and possibly some high-strain shear zones focused near one border at lower softening coefficients. Varying the viscosity contrast has less effect on the distribution of maximum finite strain. Under simple-shear boundary conditions, NW trending inherited structures make a major contribution to forming early zones of highly focused strain, up to a shear strain of about γ = 3.7. During this process, most NE-trending structures move and rotate passively, accommodate less strain, or even be abandoned through time.

  5. Pleistocene slip rates on the Boconó fault along the North Andean Block plate boundary, Venezuela

    Science.gov (United States)

    Pousse-Beltran, Lea; Vassallo, Riccardo; Audemard, Franck; Jouanne, François; Carcaillet, Julien; Pathier, Erwan; Volat, Matthieu

    2017-07-01

    The Boconó fault is a strike-slip fault lying between the North Andean Block and the South American plate which has triggered at least five Mw > 7 historical earthquakes in Venezuela. The North Andean Block is currently moving toward NNE with respect to a stable South American plate. This relative displacement at 12 mm yr-1 in Venezuela (within the Maracaibo Block) was measured by geodesy, but until now the distribution and rates of Quaternary deformation have remained partially unclear. We used two alluvial fans offset by the Boconó fault (Yaracuy Valley) to quantify slip rates, by combining 10Be cosmogenic dating with measurements of tectonic displacements on high-resolution satellite images (Pleiades). Based upon a fan dated at >79 ka and offset by 1350-1580 m and a second fan dated at 120-273 ka and offset by 1236-1500 m, we obtained two Pleistocene rates of 5.0-11.2 and <20.0 mm yr-1, consistent with the regional geodesy. This indicates that the Boconó fault in the Yaracuy Valley accommodates 40 to 100% of the deformation between the South American plate and the Maracaibo Block. As no aseismic deformation was shown by interferometric synthetic aperture radar analysis, we assume that the fault is locked since the 1812 event. This implies that there is a slip deficit in the Yaracuy Valley since the last earthquake ranging from 1 to 4 m, corresponding to a Mw 7-7.6 earthquake. This magnitude is comparable to the 1812 earthquake and to other historical events along the Boconó fault.

  6. Transformer Fault Diagnosis Based on Support Vector Machines%基于支持向量机的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    刘义艳; 陈晨; 亢旭红; 巨永锋

    2011-01-01

    Due to lack of typical damage samples in the transformer fault diagnosis, a new fault diagnosis method based on support vector machines (SVMs) is presented. According to the method, the five characteristic gases dissolved in transformer oil are extracted by the K-means clustering (KMC) method as feature vectors, which are input into multi-classified SVMs for training, and then the SVMs diagnosis model is established to implement fault samples classification. The results of experiment and analysis show that with KMC algorithm, the diagnosis information are concentrated and the great time consumption in parameter determination is remitted effectively. The presented method can detect the faults in transformer with a high correct judgment rate and can reach the purpose of automation diagnosis for transformer faults under the condition of few samples.%针对变压器故障诊断中缺少实际典型故障样本的问题,提出了支持向量机(SVMs)变压器故障诊断方法.该方法采用K均值聚类(KMC)对变压器油中5种特征气体样本进行预选取作为特征向量,输入到多分类支持向量机中进行训练,建立SVMs诊断模型,实现对故障样本的诊断分类.实例分析表明,KMC算法浓缩了故障信息,有效地解决了确定模型参数时耗时巨大的问题.该方法在有限样本情况下,能够达到较高的故障正判率,满足变压器故障自动诊断的目的.

  7. Zoogeography of the San Andreas Fault system: Great Pacific Fracture Zones correspond with spatially concordant phylogeographic boundaries in western North America.

    Science.gov (United States)

    Gottscho, Andrew D

    2016-02-01

    The purpose of this article is to provide an ultimate tectonic explanation for several well-studied zoogeographic boundaries along the west coast of North America, specifically, along the boundary of the North American and Pacific plates (the San Andreas Fault system). By reviewing 177 references from the plate tectonics and zoogeography literature, I demonstrate that four Great Pacific Fracture Zones (GPFZs) in the Pacific plate correspond with distributional limits and spatially concordant phylogeographic breaks for a wide variety of marine and terrestrial animals, including invertebrates, fish, amphibians, reptiles, birds, and mammals. These boundaries are: (1) Cape Mendocino and the North Coast Divide, (2) Point Conception and the Transverse Ranges, (3) Punta Eugenia and the Vizcaíno Desert, and (4) Cabo Corrientes and the Sierra Transvolcanica. However, discussion of the GPFZs is mostly absent from the zoogeography and phylogeography literature likely due to a disconnect between biologists and geologists. I argue that the four zoogeographic boundaries reviewed here ultimately originated via the same geological process (triple junction evolution). Finally, I suggest how a comparative phylogeographic approach can be used to test the hypothesis presented here.

  8. The Ionian and Alfeo-Etna fault zones : New segments of an evolving plate boundary in the central Mediterranean Sea?

    NARCIS (Netherlands)

    Polonia, A.; Torelli, L.; Artoni, A.; Carlini, M.; Faccenna, C.; Ferranti, L.; Gasperini, L.; Govers, R.; Klaeschen, D.; Monaco, C.; Neri, G.; Nijholt, N.; Orecchio, B.; Wortel, R.

    2016-01-01

    The Calabrian Arc is a narrow subduction-rollback system resulting from Africa/Eurasia plate convergence. While crustal shortening is taken up in the accretionary wedge, transtensive deformation accounts for margin segmentation along transverse lithospheric faults. One of these structures is the NNW

  9. Fault inference and boundary recognition based on near-bottom magnetic data in the Longqi hydrothermal field

    Science.gov (United States)

    Tao, Chunhui; Wu, Tao; Liu, Cai; Li, Huaiming; Zhang, Jinhui

    2017-06-01

    Near-bottom magnetic prospecting, which provides useful information to study shallow geological structures, is an efficient method for investigating active and inactive hydrothermal fields and researching the structure of hydrothermal systems. We collected near-bottom magnetic data in the Longqi hydrothermal area on the Southwest Indian Ridge using the Autonomous Benthic Explorer in 2007 and set up a processing system for magnetic data calibration. By removing the influence of terrain on magnetic anomalies and using the intensity of the spatial differential vector (ISDV) method, we inferred the presence of an N-S-trending fault and estimated its crush zone to be about 120 m wide and >2 km long along the known hydrothermal vents. This inferred fault is consistent with the precise topography mapped during the ABE 201 dive. The fault may be connected to a known detachment fault and form part of a hydrothermal channel. We delineated the hydrothermal alteration zone using the ISDV method and conclude that demagnetization was induced by hydrothermal alteration.

  10. The Ionian and Alfeo-Etna fault zones : New segments of an evolving plate boundary in the central Mediterranean Sea?

    NARCIS (Netherlands)

    Polonia, A.; Torelli, L.; Artoni, A.; Carlini, M.; Faccenna, C.; Ferranti, L.; Gasperini, L.; Govers, R.|info:eu-repo/dai/nl/108173836; Klaeschen, D.; Monaco, C.; Neri, G.; Nijholt, N.; Orecchio, B.; Wortel, R.|info:eu-repo/dai/nl/068439202

    2016-01-01

    The Calabrian Arc is a narrow subduction-rollback system resulting from Africa/Eurasia plate convergence. While crustal shortening is taken up in the accretionary wedge, transtensive deformation accounts for margin segmentation along transverse lithospheric faults. One of these structures is the NNW

  11. Interphase boundary structure and transformation mechanism in diffusional phase transformations; Kakusan hentai ni okeru iso kaimen kozo to hentai kiko

    Energy Technology Data Exchange (ETDEWEB)

    Furuhara, T.; Maki, T. [Kyoto University, Kyoto (Japan)

    1997-05-20

    This paper discusses a lattice changing mechanism in diffusional phase transformations (atom diffusion rate determination) based on observations through a high-resolution electron microscope. If a parent phase and a generated phase have different crystal structures, change in lamination occurs as a result of a step generated on a terrace with good consistency moving in the horizontal direction. In addition, it has been thought that removal of atoms occurs due to random diffusion jump in a riser or a kink which has a locally inconsistent structure, and no surface undulations will occur. On the other hand, growth interfaces are consistent in martensite transformation, and atomic correspondence is univocal in the parent phase and the generated phase. Also in diffusion transformation accompanying distribution of displacement type elements, the surface undulations will appear as in the case of the martensite transformation. This fact suggests that, also in the diffusional transformation, not only the terrace interface, but also the riser or kink interface having been thought inconsistent conventionally are all consistent or semi-consistent as in the martensite transformation. It also suggests that lattice correspondence exists between the parent phase and the generated phase. 30 refs., 16 figs., 1 tab.

  12. Assessment Method for the Reliability of Power Transformer Based on Fault-tree Analysis%基于粒子群优化支持向量机的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    费胜巍; 苗玉彬; 刘成良

    2009-01-01

    Accurate assessment of system reliability with limited or insufficient statistical data is difficult. At present, to assess the reliability of the transformers primarily depend on the statistics data, and the result of the assessment does not accurately reflect the reliability of a transformer. Fault tree is a powerful tool for depicting the logical relationships between the faults system. However, for a sophisticated reliability system, like power transformer,fault analysis is hard or infeasible because of the complexities of the equipment configuration and its faults. This paper presents a method which overcomes the drawbacks of traditional fault-tree analysis (FTA) by using FTA based on fault probability and equivalent calculation of each failure mode. Based on the further analysis of typical failure modes and influences of power transformer, the fault-tree of transformer is set up by using FTA techniques and the assessment method for the reliability of transformer is put forward, combined with the index of the importance and the method of improved analytic hierarchy process(IAHP). The assessment examples show the method can deduct the failure modes of transformer clearly, meanwhile, find out the weaknesses in time during the operation and get better assessment results. The method is helpful for the reliability analysis of a sophisticated system.

  13. Stacking faults and phase transformations study in ball milled Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Louidi, S., E-mail: louidisof@yahoo.fr [Laboratoire de Magnetisme et de Spectroscopie des Solides (LM2S), Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba (Algeria); Departement des Sciences de la Matiere, Faculte des Sciences, Universite 20 Aout de Skikda (Algeria); Bentayeb, F.-Z.; Tebib, W. [Laboratoire de Magnetisme et de Spectroscopie des Solides (LM2S), Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba (Algeria); Sunol, J.J.; Escoda, L. [Dep. Fisica, Universitat Girona, Campus Montilivi, 17071 Girona (Spain); Mercier, A.M. [Laboratoire des Fluorures, UMR CNRS 6010, Universite du Maine, F-72085 Le Mans Cedex 9 (France)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer We investigate the induced phase transformations fcc {r_reversible} hcp in Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys during milling. Black-Right-Pointing-Pointer The investigation is carried out by the Rietveld refinement of the XRD patterns. Black-Right-Pointing-Pointer The structural parameters of different phases are determined. Black-Right-Pointing-Pointer Ball milling induces fcc {yields} hcp and hcp {yields} fcc phase transformations in the first and the last stage of milling, respectively Black-Right-Pointing-Pointer The induced phase transformations are correlated with the stacking faults accumulation in fcc and hcp structures. - Abstract: The structural evolution and the phase transformations occurred during milling process of Co{sub 100-x}Cr{sub x} (x = 0, 20, 50) alloys are investigated by X-ray diffraction. Microstructural parameters such as the crystallites size, the microstrains, the stacking faults, the dislocation density and the phase fraction were determined from the Rietveld refinement of the X-ray diffraction patterns. The results show the formation of nanostructured alloys which depend on the initial composition of the mixture. In addition, X-ray diffraction indicates that the ball milling induces the fcc to hcp phase transformation in the first stage of milling and the reverse hcp to fcc phase transformation at the end of milling. On the basis of Warren's model, these allotropic transformations were explained by the presence of dislocations and the accumulation of stacking faults in the hcp and the fcc structures.

  14. Inverse scattering transform for the defocusing nonlinear Schrödinger equation with fully asymmetric non-zero boundary conditions

    Science.gov (United States)

    Biondini, Gino; Fagerstrom, Emily; Prinari, Barbara

    2016-10-01

    We formulate the inverse scattering transform (IST) for the defocusing nonlinear Schrödinger (NLS) equation with fully asymmetric non-zero boundary conditions (i.e., when the limiting values of the solution at space infinities have different non-zero moduli). The theory is formulated without making use of Riemann surfaces, and instead by dealing explicitly with the branched nature of the eigenvalues of the associated scattering problem. For the direct problem, we give explicit single-valued definitions of the Jost eigenfunctions and scattering coefficients over the whole complex plane, and we characterize their discontinuous behavior across the branch cut arising from the square root behavior of the corresponding eigenvalues. We pose the inverse problem as a Riemann-Hilbert Problem on an open contour, and we reduce the problem to a standard set of linear integral equations. Finally, for comparison purposes, we present the single-sheet, branch cut formulation of the inverse scattering transform for the initial value problem with symmetric (equimodular) non-zero boundary conditions, as well as for the initial value problem with one-sided non-zero boundary conditions, and we also briefly describe the formulation of the inverse scattering transform when a different choice is made for the location of the branch cuts.

  15. Fault Diagnosis of Transformer Based on D-S Evidence Theory%基于D-S证据理论的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    王日彬; 佘彩绮; 刘新东; 周锦龙

    2012-01-01

    Because the relationship between fault symptom and failure cause of power transformer is complex and the fault of transformer is not always diagnosed accurately by using single method, a new fault diagnosis method by combining grey association entropy method and weighted K-NN algorithm is proposed based on the D-S Evidence Theory in this paper. On the basis of the dissolved gases analysis (DGA), the basic credit assignment function of evidence theory is built by grey association entropy algorithm and weighted K-NN algorithm. Then, more reliable evidence information is generated by using of evidence combination rule. In the end, the fault of transformer is diagnosed according to the maximum basic credit value. The example of fault diagnosis of transformer testifies the feasibility and effectiveness of proposed algorithm, which can accurately diagnose the transformer fault.%针对电力变压器故障征兆与原因之间错综复杂的关系,以及单一变压器故障诊断算法精度有限的问题,本文提出一种在D-S证据理论的基础上,结合灰关联熵法和加权K邻近算法的变压器故障诊断新方法.该算法以油中溶解气体分析方法(Dissolved Gases Analysis,简称DGA)为基础,通过灰关联熵法和加权K邻近算法构建证据理论的基本可信度赋值函数,然后利用证据组合规则产生更为可靠的证据信息;最后根据基本可信数最大值确定变压器故障类型.变压器故障诊断实例结果表明该算法能够准确判断出变压器的故障类型,证明了该算法的可行性和有效性.

  16. A Long-term Slip Model for the San Ramón Fault, Santiago de Chile, from Tectonically Reconcilable Boundary Conditions

    Science.gov (United States)

    Aron, F.; Estay, N.; Cembrano, J. M.; Yanez, G. A.

    2016-12-01

    We constructed a 3D Boundary Elements model simulating subduction of the Nazca plate underneath South America, from 29° to 38° S, to compute long-term surface deformation and slip rates on crustal faults imbedded in the upper-plate wedge of the Andean orogen. We tested our model on the San Ramón Fault (SRF), a major E-dipping, thrust structure limiting the western front of the Main Cordillera with surface expression along the entire, 40 km long, extension of the Santiago de Chile basin. Long-lived thrusting has produced more than 2 km of differential uplift of the mountains. Given its proximity to the country's largest city, this potentially seismogenic fault —dormant during historic times— has drawn increasing public attention. We used earthquake hypocenters captured over a one-year seismic deployment, 2D resistivity profiles, and published geologic cross-sections to determine the geometry of the SRF. The base of the lithosphere and plate interface surfaces were defined based on average Andean values and the Slab1.0 model. The simulation reproduces plate convergence and mechanic decoupling of the lithospheric plates across the subduction seismic cycle using mixed boundary conditions. Relative plate motion is achieved prescribing uniform, far-field horizontal displacement over the depth extension of both the oceanic and continental lithospheric plates. Long-term deformation is carried out in two steps. First, the modeled surfaces are allowed to slip freely emulating continuous slip on the subduction megathrust; subsequently, zero displacement is prescribed on the locking zone of the megathrust down to 40 km depth, while keeping the rest of the surfaces traction free, mimicking interseismic conditions. Long-term slip rate fields obtained for the SRF range between 0.1 and 1% the plate convergence rate, with maximum values near the surface. Interestingly, at an estimated 76-77 mm/yr relative plate motion velocity, those rates agree well with what has been

  17. The Intersection between the Gloria Transform Fault and the Tore-Madeira Rise in the NE Atlantic: New Tectonic Insights from Analog Modeling Results

    Science.gov (United States)

    Rosas, F. M.; Tomas, R.; Duarte, J. C.; Schellart, W. P.; Terrinha, P.

    2014-12-01

    The intersection between the Gloria Fault (GF) and the Tore-Madeira rise (TMR) in NE Atlantic marks a transition from a discrete to a diffuse nature along a critical segment of the Eurasia/Africa plate boundary. To the West of such intersection, approximately since the Azores triple junction, this plate boundary is mostly characterized by a set of closely aligned and continuous strike-slip faults that make up the narrow active dextral transcurrent system of the GF (with high magnitude M>7 historical earthquakes). While intersecting the TMR the closely E-W trending trace of the GF system is slightly deflected (changing to WNW-ESE), and splays into several fault branches that often coincide with aligned (TMR related?) active volcanic plugs. The segment of the plate boundary between the TMR and the Gorringe Bank (further to the East) corresponds to a more complex (less discrete) tectonic configuration, within which the tectonic connection between the Gloria Fault and another major dextral transcurrent system (the so called SWIM system) occurs. This SWIM fault system has been described to extend even further to the East (almost until the Straits of Gibraltar) across the Gulf of Cadiz domain. In this domain the relative movement between the Eurasian and the African plates is thought to be accommodated through a diffuse manner, involving large scale strain partition between a dextral transcurrent fault-system (the SWIM system), and a set of active west-directed én-échelon major thrusts extending to the North along the SW Iberian margin. We present new analog modeling results, in which we employed different experimental settings to address (namely) the following main questions (as a first step to gain new insight on the tectonic evolution of the TRM-GF critical intersection area): Could the observed morphotectonic configuration of such intersection be simply caused by a bathymetric anomaly determined by a postulated thickened oceanic crust, or is it more compatible with

  18. Special Case Analysis of A Large Transformer Oil Dielectric Loss Fault%大型变压器油介损超标现场特例分析

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    The fault analysis and special solution to a transformer oil dielectric loss were given .Then some ignored reasons for oil dielectric loss were presented in the prodution of transformers .%  介绍了大型变压器油介质损耗因数(简称介损)超标的故障及典型处理方法,以及变压器生产制造过程中容易忽视的可能导致介损超标的一些细节因素。

  19. Spatial and temporal variations in creep rate along the El Pilar fault at the Caribbean-South American plate boundary (Venezuela), from InSAR

    Science.gov (United States)

    Pousse Beltran, Léa.; Pathier, Erwan; Jouanne, François; Vassallo, Riccardo; Reinoza, Carlos; Audemard, Franck; Doin, Marie Pierre; Volat, Matthieu

    2016-11-01

    In eastern Venezuela, the Caribbean-South American plate boundary follows the El Pilar fault system. Previous studies based on three GPS campaigns (2003-2005-2013) demonstrated that the El Pilar fault accommodates the whole relative displacement between the two tectonic plates (20 mm/yr) and proposed that 50-60% of the slip is aseismic. In order to quantify the possible variations of the aseismic creep in time and space, we conducted an interferometric synthetic aperture radar (InSAR) time series analysis, using the (NSBAS) New Small BAseline Subset method, on 18 images from the Advanced Land Observing Satellite (ALOS-1) satellite spanning the 2007-2011 period. During this 3.5 year period, InSAR observations show that aseismic slip decreases eastward along the fault: the creep rate of the western segment reaches 25.3 ± 9.4 mm/yr on average, compared to 13.4 ± 6.9 mm/yr on average for the eastern segment. This is interpreted, through slip distribution models, as being related to coupled and uncoupled areas between the surface and 20 km in depth. InSAR observations also show significant temporal creep rate variations (accelerations) during the considered time span along the western segment. The transient behavior of the creep is not consistent with typical postseismic afterslip following the 1997 Ms 6.8 earthquake. The creep is thus interpreted as persistent aseismic slip during an interseismic period, which has a pulse- or transient-like behavior.

  20. Analysis of geometry of volcanoes and faults in Terceira Island (Azores): Evidence for reactivation tectonics at the EUR/AFR plate boundary in the Azores triple junction

    Science.gov (United States)

    Navarro, A.; Lourenço, N.; Chorowicz, J.; Miranda, J. M.; Catalão, J.

    2009-02-01

    The late Pliocene to Quaternary (5 Ma) volcanism in the central and eastern Azores Archipelago is related to the Eurasia/Africa divergence, but a clear deformation pattern has not yet been established at this location. This work focuses on the contribution of Synthetic Aperture Radar (SAR) scenes and Digital Elevation Models (DEM), complemented with geophysical, geodetic and morpho-structural data, to establish the geometric relationships between volcanic edifices and tectonic structures in the central and eastern Azores Archipelago. Bathymetric data were also used to extend field observations to the significant submarine area of the Azores plateau. Strikes of extension fractures, directly observed or inferred from elongated volcanic vents or linear volcanic clusters in Terceira Island, indicate that volcanism is mainly controlled by regional extension as given by NUVEL-1A plate motion model. Additionally, other directions were also detected for extension fractures around the Santa Barbara volcano (defining a radial pattern) and in the central part of the island (exhibiting an S-shape pattern). Although most of the volcanic vents are controlled by extension fractures, some seem to be controlled by faulting, such as the case of the ones rooted in releasing bends along strike-slip or oblique-slip faults in the central part of the island. Concerning the Azores plateau, most of the structures have directions that do not directly fit with present-day direction of relative motion (˜ N70°) between Eurasia and Africa. Directions ranging from N110° to N125°, found mainly along the Terceira rift, are interpreted as ancient transform directions, reactivating as transtensional fault zones due to the present-day plate motion. N-S directions are also visible in the plateau, being interpreted as former middle-oceanic rift faults reactivated as left-lateral fault zones. These results contrast with the volcanic expression in other hotspot dominated oceanic islands such as the

  1. Geochronology Constraints on Transformation Age from Ductile to Brittle Deformation of the Shangma Fault and Its Tectonic Significance, Dabieshan, Central China

    Institute of Scientific and Technical Information of China (English)

    Wang Guocan; Wang Pu; Liu Chao; Wang An; Ye Runqing

    2008-01-01

    By a detailed investigation of geometry and kinematics of the Shangma (商麻) fault in Dabieshan (大别山),three different crust levels of extension movement have been recognized in sequence from the deep to the shallow:① low-angle ductile detachment shearing with top to the NW; ② low-angle normal fault with top to the NW or NWW in brittle or brittle-ductile transition domain; ③high-angle brittle normal fault with top to the W or NWW. Two samples were chosen for zircon U-Pb age dating to constrain the activity age of the Shangma fault. A bedding intrusive granitoid pegmatite vein that is parallel to the foliation of the low-angle ductile detachment shear zone of the country rock exhibits a lotus-joint type of boudinage deformation,showing syn-tectonic emplacing at the end of the ductile deformation period and deformation in the brittle-ductile transition domain. The zircon U-Pb dating of this granitoid pegmatite vein gives an age of (125.9±4.2) Ma,which expresses the extension in the brittle-ductile transition domain of the Shangma fault. The other sample,which is collected from a granite pluton cutting the foliation of the low-angle ductile detachment shear zone, gives a zircon U-Pb age of (118.8±4.1) Ma,constraining the end of the ductile detachment shearing. Then the transformation age from ductile to brittle deformation can be constrained between 126-119 Ma.Combined with the previous researches,the formation of the Luotian (罗田) dome,which is located to the east of the Shangma fault,can beconstrained during 150-126 Ma. This study gives a new time constraint to the evolution of the Dabie orogenic belt.

  2. Caltepec fault zone: An Early Permian dextral transpressional boundary between the Proterozoic Oaxacan and Paleozoic Acatlán complexes, southern Mexico, and regional tectonic implications

    Science.gov (United States)

    Elías-Herrera, Mariano; Ortega-Gutiérrez, Fernando

    2002-06-01

    The tectonic boundary between the Grenville-age Oaxacan and Paleozoic Acatlán crystalline complexes in southern Mexico, named the Caltepec fault zone (CFZ), is characterized for the first time as a dextral transpressional, NNW trending and ENE dipping ductile fault zone of Early Permian age. The complexes are welded by a syntectonic magmatic epidote-bearing granite along the entire length of the CFZ. From east to west, the 2-6 km wide CFZ consists of disrupted and retrograded banded gneisses of the Oaxacan complex, quartz-feldspar mylonite, and the syntectonic magmatic epidote-bearing Cozahuico granite (CZG) with huge xenoliths (up to several kilometers long and up to 600 m wide) of the Proterozoic gneisses, thrust westward over metasedimentary tectonites of the Acatlán complex. The CZG shows magmatic fabrics that represent a transition to solid-state deformation characterized by subvertical foliation, subhorizontal NNE and SSE dipping mineral stretching lineation and dextral kinematics. The megaxenoliths underwent partial melting developing banded migmatites with layers of epidote-bearing granitic neosome. The parallelism of fabrics in these anatexitic rocks and in the enclosing deformed granite suggests that ductile deformation, migmatization of xenolithic gneisses, and granite emplacement along the CFZ were coeval. The neosome yielded a U-Pb zircon concordant age of 275.6 +/- 1 Ma probably dating the peak of the tectonothermal event. We interpret the CFZ as a major terrane boundary accommodating transpressional interaction between the Acatlán and Oaxaquia blocks, which were amalgamated in an oblique convergent setting by Early Permian time, as the leading edge of Gondwana impinged onto the southern margin of Laurentia along the Marathon-Ouachita suture to form Pangea.

  3. Space-time domain solutions of the wave equation by a non-singular boundary integral method and Fourier transform.

    Science.gov (United States)

    Klaseboer, Evert; Sepehrirahnama, Shahrokh; Chan, Derek Y C

    2017-08-01

    The general space-time evolution of the scattering of an incident acoustic plane wave pulse by an arbitrary configuration of targets is treated by employing a recently developed non-singular boundary integral method to solve the Helmholtz equation in the frequency domain from which the space-time solution of the wave equation is obtained using the fast Fourier transform. The non-singular boundary integral solution can enforce the radiation boundary condition at infinity exactly and can account for multiple scattering effects at all spacings between scatterers without adverse effects on the numerical precision. More generally, the absence of singular kernels in the non-singular integral equation confers high numerical stability and precision for smaller numbers of degrees of freedom. The use of fast Fourier transform to obtain the time dependence is not constrained to discrete time steps and is particularly efficient for studying the response to different incident pulses by the same configuration of scatterers. The precision that can be attained using a smaller number of Fourier components is also quantified.

  4. A Novel Method for Inverter Faults Detection and Diagnosis in PMSM Drives of HEVs based on Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    AKTAS, M.

    2012-11-01

    Full Text Available The paper proposes a novel method, based on wavelet decomposition, for detection and diagnosis of faults (switch short-circuits and switch open-circuits in the driving systems with Field Oriented Controlled Permanent Magnet Synchro?nous Motors (PMSM of Hybrid Electric Vehicles. The fault behaviour of the analyzed system was simulated by Matlab/SIMULINK R2010a. The stator currents during transients were analysed up to the sixth level detail wavelet decomposition by Symlet2 wavelet. The results prove that the proposed fault diagnosis system have very good capabilities.

  5. 基于BP神经网络的变压器内部故障保护%Internal fault protection based on BP neural network transformer

    Institute of Scientific and Technical Information of China (English)

    苏美玲; 邹晓松; 何杰

    2016-01-01

    本文研究了基于BP神经网络方法的变压器内部故障保护。运用MATLAB/SUMILINK对变压器励磁涌流、励磁涌流与故障电流的差异进行了数字仿真。利用MATLAB的人工神经网络工具箱,建立了BP神经网络模型,对励磁涌流和故障电流的样本进行训练及测试并对训练好的网络进行验证。表明BP神经网络可以较为正确地区分励磁涌流和故障电流,用于变压器内部故障保护。%This paper discussed a transformer protection based on Back- Propagation Network .Digital simulation were made on the inrush current of the transformer and on the comparison between the inrush current and the fault current of the transformer. Back- Propagation Network model was set up by using the MATLAB artificial neural network toolbox. The results show that the Back- Propagation Network almost can correctly distinguish between excitation inrush current and the fault current of the transformer.

  6. Bearing fault diagnosis under variable rotational speed via the joint application of windowed fractal dimension transform and generalized demodulation: A method free from prefiltering and resampling

    Science.gov (United States)

    Shi, Juanjuan; Liang, Ming; Guan, Yunpeng

    2016-02-01

    The conventional way for bearing fault diagnosis under variable rotational speed generally includes prefiltering, resampling based on shaft rotating frequency and order spectrum analysis. However, its application is confined by three major obstacles: a) knowledge-demanding parameter determination required by prefiltering, b) unavailable shaft rotating frequency for resampling as it is coupled with instantaneous fault characteristic frequency (IFCF) by a fault characteristic coefficient (FCC) which cannot be decided without knowing what fault actually exists, and c) complicated and error-prone resampling process. As such, we propose a new method to address these problems. The proposed method free from prefiltering and resampling mainly contains the following steps: a) extracting envelope by windowed fractal dimension (FD) transform, requiring no prefiltering, b) with the envelope signal, performing short time Fourier transform (STFT) to get a clear time frequency representation (TFR), from which the IFCF and the basic demodulator for generalized demodulation (GD) can be obtained, c) applying the generalized demodulation to the envelope signal with the current demodulator, converting the trajectory of the current time-frequency component into a linear path parallel to the time axis, d) frequency analyzing the demodulated signal, followed by searching the amplitude of the constant frequency where the linear path is situated. Updating demodulator via multiplying the basic demodulator by different real numbers (i.e., coefficient λ) and repeating the steps (c)-(d), the resampling-free order spectrum is then obtained. Based on the resulting spectrum, the final diagnosis decision can be made. The proposed method for its implementation on the example of simulated data is presented. Finally, experimental data are employed to validate the effectiveness of the proposed technique.

  7. Conservation Laws, Hodograph Transformation and Boundary Value Problems of Plane Plasticity

    Directory of Open Access Journals (Sweden)

    Sergey I. Senashov

    2012-10-01

    Full Text Available For the hyperbolic system of quasilinear first-order partial differential equations, linearizable by hodograph transformation, the conservation laws are used to solve the Cauchy problem. The equivalence of the initial problem for quasilinear system and the problem for conservation laws system permits to construct the characteristic lines in domains, where Jacobian of hodograph transformations is equal to zero. Moreover, the conservation laws give all solutions of the linearized system. Some examples from the gas dynamics and theory of plasticity are considered.

  8. FLUID BOUNDARY ELEMENT METHOD AND ORTHOGONAL TRANSFORM OF DOUBLE COMPLEX VARIABLES

    Institute of Scientific and Technical Information of China (English)

    罗义银

    2003-01-01

    A concept of orthogonal double function and its complex variables space was putforward. Its corresponding operation rules, the concept of analytic function and conformaltransform are established. And using this concept discussed its foreground for application offluid boundary element method. In results, this concept and special marks may be toenlarge the plane complex into three-dimensional space, and then extensive application maybe obtained in physics and mathematics.

  9. Martensitic transformation of pure iron at a grain boundary: Atomistic evidence for a two-step Kurdjumov-Sachs-Pitsch pathway

    Science.gov (United States)

    Meiser, Jerome; Urbassek, Herbert M.

    2016-08-01

    Using classical molecular dynamics simulations and the Meyer-Entel interaction potential, we study the martensitic transformation pathway in a pure iron bi-crystal containing a symmetric tilt grain boundary. Upon cooling the system from the austenitic phase, the transformation starts with the nucleation of the martensitic phase near the grain boundary in a plate-like arrangement. The Kurdjumov-Sachs orientation relations are fulfilled at the plates. During further cooling, the plates expand and merge. In contrast to the orientation relation in the plate structure, the complete transformation proceeds via the Pitsch pathway.

  10. Fast Domain Partitioning Method for dynamic boundary integral equations applicable to non-planar faults dipping in 3-D elastic half-space

    Science.gov (United States)

    Ando, Ryosuke

    2016-11-01

    The elastodynamic boundary integral equation method (BIEM) in real space and in the temporal domain is an accurate semi-analytical tool to investigate the earthquake rupture dynamics on non-planar faults. However, its heavy computational demand for a historic integral generally increases with a time complexity of O(MN3)for the number of time steps N and elements M due to volume integration in the causality cone. In this study, we introduce an efficient BIEM, termed the `Fast Domain Partitioning Method' (FDPM), which enables us to reduce the computation time to the order of the surface integral, O(MN2), without degrading the accuracy. The memory requirement is also reduced to O(M2) from O(M2N). FDPM uses the physical nature of Green's function for stress to partition the causality cone into the domains of the P and S wave fronts, the domain in-between the P and S wave fronts, and the domain of the static equilibrium, where the latter two domains exhibit simpler dependences on time and/or space. The scalability of this method is demonstrated on the large-scale parallel computing environments of distributed memory systems. It is also shown that FDPM enables an efficient use of memory storage, which makes it possible to reduce computation times to a previously unprecedented level. We thus present FDPM as a powerful tool to break through the current fundamental difficulties in running dynamic simulations of coseismic ruptures and earthquake cycles under realistic conditions of fault geometries.

  11. Scaling group transformation for MHD boundary layer flow over permeable stretching sheet in presence of slip flow with Newtonian heating effects

    Institute of Scientific and Technical Information of China (English)

    A A AFIFY; M J UDDIN; M FERDOWS

    2014-01-01

    Taking into account the slip flow effects, Newtonian heating, and thermal radiation, two-dimensional magnetohydrodynamic (MHD) flows and heat transfer past a permeable stretching sheet are investigated numerically. We use one parameter group transformation to develop similarity transformation. By using the similarity transfor-mation, we transform the governing boundary layer equations along with the boundary conditions into ordinary differential equations with relevant boundary conditions. The ob-tained ordinary differential equations are solved with the fourth-fifth order Runge-Kutta-Fehlberg method using MAPLE 13. The present paper is compared with a published one. Good agreement is obtained. Numerical results for dimensionless velocity, temperature distributions, skin friction factor, and heat transfer rates are discussed for various values of controlling parameters.

  12. DIAGNOSIS OF INSIDIOUS FAULT INSIDE POWER TRANSFORMER%变压器内部潜伏性故障的诊断方法

    Institute of Scientific and Technical Information of China (English)

    倪健

    2001-01-01

    Some common-used methods and measuring instruments by gas chromatography are described in this paper for the fault diagnosis inside transformer. The feature and the demerit of gas chromatography are stated.%介绍了用于判断变压器内部故障的几种常用的气相色谱分析法及其常用测试仪器,指出了气相色谱法的特点和不足。

  13. Precarious rock and overturned transformer evidence for ground shaking in the Ms 7.7 Kern County earthquake: An analog for disastrous shaking from a major thrust fault in the Los Angeles basin

    Science.gov (United States)

    Brune, J.N.; Anooshehpoor, A.; Shi, B.; Zheng, Yen

    2004-01-01

    Precariously balanced rocks and overturned transformers in the vicinity of the White Wolf fault provide constraints on ground motion during the 1952 Ms 7.7 Kern County earthquake, a possible analog for an anticipated large earthquake in the Los Angeles basin (Shaw et al., 2002; Dolan et al., 2003). On the northeast part of the fault preliminary estimates of ground motion on the footwall give peak accelerations considerably lower than predicted by standard regression curves. On the other hand, on the hanging-wall, there is evidence of intense ground shattering and lack of precarious rocks, consistent with the intense hanging-wall accelerations suggested by foam-rubber modeling, numerical modeling, and observations from previous thrust fault earthquakes. There is clear evidence of the effects of rupture directivity in ground motions on the hanging-wall side of the fault (from both precarious rocks and numerical simulations). On the southwest part of the fault, which is covered by sediments, the thrust fault did not reach the surface ("blind" thrust). Overturned and damaged transformers indicate significant transfer of energy from the hanging wall to the footwall, an effect that may not be as effective when the rupture reaches the surface (is not "blind"). Transformers near the up-dip projection of the fault tip have been damaged or overturned on both the hanging-wall and footwall sides of the fault. The transfer of energy is confirmed in a numerical lattice model and could play an important role in a similar situation in Los Angeles. We suggest that the results of this study can provide important information for estimating the effects of a large thrust fault rupture in the Los Angeles basin, specially given the fact that there is so little instrumental data from large thrust fault earthquakes.

  14. Global strike-slip faults: Bounds from plate tectonics

    Science.gov (United States)

    Gordon, R. G.; Argus, D. F.

    2006-12-01

    According to the tenets of plate tectonics, a transform fault is a strike-slip fault along which neither convergence nor divergence occurs. Analysis of global plate motion data indicates that the only true transform faults are the strike-slip faults that offset segments of mid-ocean ridges. Thus, many of Earth's major strike-slip fault systems are not true transform faults as they accommodate large components of oblique convergence or oblique divergence. This is particularly true for several important ocean-continent systems such as the San Andreas, the strike-slip systems bounding the northern and southern Caribbean plate, the Alpine fault system of New Zealand, the Anatolian fault system, and the Azores-Gibraltar-Alboran sea system. These strike-slip systems are commonly sites of large scale mountain building and basin formation. Here we examine the far-field constraints on the motions of the plates bounding several of these strike-slip systems using both conventional plate motion circuits and results from global positioning system and other space geodetic data. We pay particular attention to the San Andreas fault system in central and northern California, where the San Andreas system is part of the boundary between the Sierran microplate and the Pacific plate. Most of the fault system accommodates obliquely convergent motion, giving rise to the California Coast Range, but in the northern San Francisco Bay Area it is obliquely divergent, producing San Pablo Bay and a gap in the Coast Range that permits the Sierran watershed to drain to the Pacific through the Golden Gate.

  15. A Novel Method of Fault Diagnosis for Rolling Bearing Based on Dual Tree Complex Wavelet Packet Transform and Improved Multiscale Permutation Entropy

    Directory of Open Access Journals (Sweden)

    Guiji Tang

    2016-01-01

    Full Text Available A novel method of fault diagnosis for rolling bearing, which combines the dual tree complex wavelet packet transform (DTCWPT, the improved multiscale permutation entropy (IMPE, and the linear local tangent space alignment (LLTSA with the extreme learning machine (ELM, is put forward in this paper. In this method, in order to effectively discover the underlying feature information, DTCWPT, which has the attractive properties as nearly shift invariance and reduced aliasing, is firstly utilized to decompose the original signal into a set of subband signals. Then, IMPE, which is designed to reduce the variability of entropy measures, is applied to characterize the properties of each obtained subband signal at different scales. Furthermore, the feature vectors are constructed by combining IMPE of each subband signal. After the feature vectors construction, LLTSA is employed to compress the high dimensional vectors of the training and the testing samples into the low dimensional vectors with better distinguishability. Finally, the ELM classifier is used to automatically accomplish the condition identification with the low dimensional feature vectors. The experimental data analysis results validate the effectiveness of the presented diagnosis method and demonstrate that this method can be applied to distinguish the different fault types and fault degrees of rolling bearings.

  16. Transformer Winding Common Fault and Processing Method Analysis%变压器绕组常见故障及处理方法探析

    Institute of Scientific and Technical Information of China (English)

    段成琳

    2012-01-01

      The power system transformer is very main a equipment, transformer in good operating safety of power grid has a very important significance. Although transformer the operation reliability of rising, but its winding trigger fault or frequent. Transformer winding in the event of failure will cause transformer decommissioning, at the same time for the safety of power grid operation and production brings the serious influence.%  电力系统中变压器是非常主要的一次设备,变压器的良好运行对电网安全具有非常重要的意义。虽然变压器运行的可靠性不断提升,但其绕组引发的故障还是频繁发生。变压器绕组如果发生故障将引起变压器的停运,同时对电网的安全运行和生产带来严重影响。

  17. 基于小波变换的电力电缆故障测距研究%Research of Power Cable Fault Location Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    廖晓辉; 梁恒娜; 丁倩

    2013-01-01

    With wide application of power cable in transmission and distribution systems,the demand for cable fault location accuracy is improved.In order to locate cable fault accurately,the wavelet transform is applied in detecting the traveling wave signal of power cable.According to the principle of singularity detection of signals,the traveling wave starting pulse and reflection pulse time point is determined by searching modulus maximum,and then locating by single terminal traveling wave method for the online fault location.The experimen tal results show that the traveling wave singularity point can be detected by using localized time-frequencycharacteristic of wavelet transform,thereby the accurate time of pulse arrival is obtained.This method is not affected by fault type and the range error is small,which can achieve a higher fault location accuracy.%随着电力电缆的广泛应用,对电缆故障测距的精确度要求也日益提高.为了实现电缆故障的精确定位,引入小波变换的方法对电缆故障行波信号进行检测和分析,根据信号的奇异性检测原理,采用搜索模极大值的方法确定行波信号起始脉冲和反射脉冲时间点,应用单端行波在线故障测距方法进行测距,实验结果表明,利用小波变换的时频局部化特性可有效聚焦到电缆行波信号的奇异点,从而得到精确的脉冲到达时刻.该方法不受电缆故障类型的影响,测距误差小,可获得较高的故障定位精度.

  18. Mobilities and dislocation energies of planar faults in an ordered A3B (D019) structure

    Indian Academy of Sciences (India)

    A K Singh; R Sankarasubramanian; T K Nandy

    2013-08-01

    Present work describes the stability of possible planar faults of the A3B (D019) phase with an axial ratio less than the ideal. Mobilities and dislocation energies of various planar faults viz. antiphase boundaries (APBs), superlattice intrinsic stacking faults (SISFs) and complex stacking faults (CSFs) have been computed using complex fourth-order tensor transformations and hard sphere model. Displacements normal to the slip planes for various slip systems (vertical shift) have been used to calculate mobility of dislocations. The energy of the planar faults in Ti3Al intermetallic is calculated using some simplifying assumptions. Based on the mobility and energy, stability of planar faults has been explained. These results are compared with single crystal ordered Ti3Al alloy having D019 structure.

  19. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    A. Petzold

    2007-10-01

    Full Text Available Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B{&}W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aerosol transformation studies in the plume of a large container ship in the English Channel using the DLR aircraft Falcon 20 E-5. Observations from emission studies and plume studies combined with a Gaussian plume dispersion model yield a consistent picture of particle transformation processes from emission to atmospheric processing during plume expansion. Particulate matter emission indices obtained from plume measurements are 8.8±1.0×1015(kg fuel−1 by number for non-volatile particles and 174±43 mg (kg fuel−1 by mass for Black Carbon (BC. Values determined for test rig conditions between 85 and 110% engine load are of similar magnitude. For the total particle number including volatile compounds no emission index can be derived since the volatile aerosol fraction is subject to rapid transformation processes in the plume. Ship exhaust particles occur in the size range Dp<0.3 μm, showing a bi-modal structure. The combustion particle mode is centred at modal diameters of 0.05 μm for raw emissions to 0.10 μm at a plume age of 1 h. The smaller-sized volatile particle mode is centred at Dp≤0.02 μm. From the decay of ship exhaust particle number concentrations in an expanding plume, a maximum plume life time of approx. 24 h is estimated for a well-mixed marine boundary layer.

  20. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    A. Petzold

    2008-05-01

    Full Text Available Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B&W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aerosol transformation studies in the plume of a large container ship in the English Channel using the DLR aircraft Falcon 20 E-5. Observations from emission studies and plume studies combined with a Gaussian plume dispersion model yield a consistent picture of particle transformation processes from emission to atmospheric processing during plume expansion. Particulate matter emission indices obtained from plume measurements are 8.8±1.0×1015(kg fuel−1 by number for non-volatile particles and 174±43 mg (kg fuel−1 by mass for Black Carbon (BC. Values determined for test rig conditions between 85 and 110% engine load are of similar magnitude. For the total particle number including volatile compounds no emission index can be derived since the volatile aerosol fraction is subject to rapid transformation processes in the plume. Ship exhaust particles occur in the size range Dp<0.3 μm, showing a bi-modal structure. The combustion particle mode is centred at modal diameters of 0.05 μm for raw emissions to 0.10 μm at a plume age of 1 h. The smaller-sized volatile particle mode is centred at Dp≤0.02 μm. From the decay of ship exhaust particle number concentrations in an expanding plume, a maximum plume life time of approx. 24 h is estimated for a well-mixed marine boundary layer.

  1. Research of Magnetizing Inrush Current and Fault Current Identification Based on Wavelet Transform in Transformer Protection%基于小波变换的变压器励磁涌流和故障电流识别研究

    Institute of Scientific and Technical Information of China (English)

    张晓; 张建文; 潘磊落

    2012-01-01

    变压器差动保护是变压器的重要保护之一,在变压器差动保护中,励磁涌流的准确识别是保护可靠动作的保证,也是变压器保护的难点之一.本文利用Matlab/Simulink建立模型进行仿真,得到了励磁涌流与内部故障电流的波形.通过快速傅里叶变换对其进行分析,总结了励磁涌流的波形特点;对其进行小波分解,发现两者小波分解后第三尺度的细节信号有较大不同,并得到了用于区分两者的判据,可用于变压器差动保护中励磁涌流的识别.%Differential protection is one of important protective schemes for transformers, accurate identification of magnetizing inrush current is the guarantee for reliable action, and it is also one of hard problems in transformers differential protection. The waveforms of magnetizing inrush current and fault current are obtained by modeling and simulating in Matlab/Simulink. Utilizing FFT, the waveform features of magnetizing inrush current are analyzed; and the level 3 detailed signal of magnetizing inrush current and fault current are detected different by wavelet transform. A wavelet transform method is proposed to recognize magnetizing inrush current and can be used in transformers differential protection.

  2. Decentralisation, Participation and Boundaries of Transformation: Forest Rights Act, Wayanad, India

    Directory of Open Access Journals (Sweden)

    Sudheesh R. Chemmencheri

    2013-05-01

    Full Text Available Participation and decentralisation have been shown to yield democratic outcomes in terms of efficiency, accountability and transparency through citizen engagement and devolution of powers. It has been a matter of debate whether they also benefit marginalised communities like the indigenous peoples. This paper analyzes the implications of decentralised governance in a tribal zone in India using the case of the Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights Act 2006 − the Forest Rights Act. The effects of the Act are studied in the district of Wayanad, Kerala, through the theoretical framework of transformative decentralisation and spatial politics of participation. The key objectives of the Act − securing tenure and access to Minor Forest Produce − have achieved limited success in Wayanad as a result of a narrowly construed ideas of people’s participation. While the process prescribed by the Forest Rights Act has the potential to create new spaces for participation, most of these spaces remain closed in Wayanad. The absence of a larger vision and a radical motive to engage with the underlying patterns of domination and subordination in society has confined the process of decentralisation to its technocratic essentials, raising questions on the extent to which the Act can pave the way for transformation.

  3. The Mw6.5 earthquake of 17 November 2015 in Lefkada Island and the seismotectonics in the Cephalonia Transform Fault (Ionian Sea, Greece)

    Science.gov (United States)

    Papadopoulos, Gerassimos A.; Agalos, Apostolos; Bocchini, Gian Maria; Chousianitis, Konstantinos; Karastathis, Vassilis; Triantafyllou, Ioanna; Kontoes, Charis; Papoutsis, Ioannis; Svigkas, Nikos; Koukouvelas, Ioannis; Zygouri, Vasiliki; Tselentis, Akis

    2016-04-01

    inversion method, which is capable of estimating the distributions of both the spatial slip and rise time on the ruptured fault, was applied using the Harvard CMT focal mechanism solution. The above velocity model was used to create the subfault synthetics. It was found that the earthquake had a not very complex source time function with nearly 78 cm maximum slip with source duration of ~13 s. Most of the slip is concentrated on a 14 km x 7 km fault rupture. The rupture propagated from the mainshock focal depth of 12 km upwards and southwards. Taking into account together the Cephalonia Jan.-Febr. 2014 seismic sequence and the Lefkada 2015 sequence, the overall seismotectonic picture is that the northern (Lefkada) branch of the Cephalonia Transform Fault (CTF) continues towards SW intersecting western Cephalonia. Also, it is likely that the 2015 earthquake fits the characteristic earthquake model suggested for the area after the 2003 Lefkada earthquake by considering also the historical seismicity of the area. This research is a contribution to the EU-FP7 ITN research project ZIP (Zooming In between Plates, grant agreement no: 604713, 2013.

  4. Geology and geochemistry of the Bingdaban ophiolitic mélange in the boundary fault zone on the northern Central Tianshan Belt, and its tectonic implications

    Institute of Scientific and Technical Information of China (English)

    DONG YunPeng; ZHANG GuoWei; ZHOU DingWu; LUO JinHai; ZHANG ChengLi; XIA LinQi; XU XueYi; LI XiangMin

    2007-01-01

    The properties and tectonic significance of the fault bound zone on the northern margin of the Central Tianshan belt are key issues to understand the tectonic framework and evolutionary history of the Tianshan Orogenic Belt. Based on the geological and geochemical studies in the Tianshan orogenic belt, it is suggested that the ophiolitic slices found in the Bingdaban area represent the remaining oceanic crust of the Early Paleozoic ocean between the Hazakstan and Zhungaer blocks. Mainly composed of basalts, gabbros and diabases, the ophiolites were overthrust onto the boundary fault between the Northern Tianshan and Central Tianshan belts. The major element geochemistry is characterized by high TiO2 (1.50%-2.25%) and MgO (6.64%-9.35%), low K2O (0.06%-0.41%) and P2O5 (0.1%-0.2%), and Na2O>K2O as well. Low ∑REE and depletion in LREE indicate that the original magma was derived from a depleted mantle source. Compared with a primitive mantle, the geochemistry of the basalts from the Bingdaban area is featureded by depletion in Th, U, Nb, La, Ce and Pr, and unfractionated in HFS elements. The ratios of Zr/Nb, Nb/La, Hf/Ta, Th/Yb and Hf/Th are similar to those of the typical N-MORB. It can be interpreted that the basalts in the Bingdaban area were derived from a depleted mantle source, and formed in a matured mid-oceanic ridge setting during the matured evolutionary stage of the Northern Tianshan ocean. In comparison with the basalts, the diabases from the Bingdaban area show higher contents of Al2O3, (REE and HFS elements as well as unfractionated incompatible elements except Cs, Rb and Ba, and about 10 times the values of the primitive mantle. Thus, the diabases are thought to be derived from a primitive mantle and similar to the typical E-MORB. The diabases also have slight Nb depletion accompanying no apparent Th enrichment compared with N-MORB. From studies of the regional geology and all above evidence, it can be suggested that the diabases from the Bingdaban

  5. Geology and geochemistry of the Bingdaban ophiolitic mélange in the boundary fault zone on the northern Central Tianshan Belt,and its tectonic implications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The properties and tectonic significance of the fault bound zone on the northern margin of the Central Tianshan belt are key issues to understand the tectonic framework and evolutionary history of the Tianshan Orogenic Belt. Based on the geological and geochemical studies in the Tianshan orogenic belt, it is suggested that the ophiolitic slices found in the Bingdaban area represent the remaining oceanic crust of the Early Paleozoic ocean between the Hazakstan and Zhungaer blocks. Mainly com-posed of basalts, gabbros and diabases, the ophiolites were overthrust onto the boundary fault be-tween the Northern Tianshan and Central Tianshan belts. The major element geochemistry is charac-terized by high TiO2 (1.50%-2.25%) and MgO (6.64%-9.35%), low K2O (0.06%-0.41%) and P2O5 (0.1%-0.2%), and Na2O>K2O as well. Low ΣREE and depletion in LREE indicate that the original magma was derived from a depleted mantle source. Compared with a primitive mantle, the geochemistry of the basalts from the Bingdaban area is featureded by depletion in Th, U, Nb, La, Ce and Pr, and unfrac-tionated in HFS elements. The ratios of Zr/Nb, Nb/La, Hf/Ta, Th/Yb and Hf/Th are similar to those of the typical N-MORB. It can be interpreted that the basalts in the Bingdaban area were derived from a de-pleted mantle source, and formed in a matured mid-oceanic ridge setting during the matured evolu-tionary stage of the Northern Tianshan ocean. In comparison with the basalts, the diabases from the Bingdaban area show higher contents of Al2O3, ∑REE and HFS elements as well as unfractionated incompatible elements except Cs, Rb and Ba, and about 10 times the values of the primitive mantle. Thus, the diabases are thought to be derived from a primitive mantle and similar to the typical E-MORB. The diabases also have slight Nb depletion accompanying no apparent Th enrichment compared with N-MORB. From studies of the regional geology and all above evidence, it can be suggested that the diabases from the

  6. Possible Interactions between the 2012 Mw 7.8 Haida Gwaii Subduction Earthquake and the Transform Queen Charlotte Fault

    Science.gov (United States)

    Hobbs, T. E.; Cassidy, J. F.; Dosso, S. E.

    2014-12-01

    This paper examines the effect of the October 2012 Mw 7.8 Haida Gwaii earthquake on aftershock nodal planes and the neighboring Queen Charlotte Fault (QCF) through Coulomb modeling and directivity analysis. The Haida Gwaii earthquake was the largest thrust event recorded in this region and ruptured an area of ~150 by 40 km on a gently NE-dipping fault off the west coast of Moresby Island, British Columbia. It is particularly interesting as it is located just to the west of the QCF, the predominantly right-lateral strike-slip fault separating the Pacific and North American plates. The QCF was the site of the largest recorded earthquake in Canada: the 1949 Ms 8.1 strike-slip earthquake whose rupture extended as far south as this 2012 event and roughly as far north as an Mw7.5 strike slip event at Craig, Alaska, which occurred just two months later in January 2013. The 75 km long portion of the QCF south of the 1949 rupture has not had a large (M ≥ 7) earthquake in over 116 years, representing a significant seismic gap. Coulomb stress transfer analysis is performed using finite fault models which incorporate seismic and geodetic data. Static stress changes are projected onto aftershock nodal planes and the QCF, including an inferred southern seismic gap. We find up to 86% of aftershocks are consistent with triggering, and as high as 96% for normal faulting events. The QCF experiences static stress changes greater than the empirically-determined threshold for triggering, with positive stress changes predicted for roughly half of the seismic gap region. Added stress from the mainshock and a lack of post-mainshock events make this seismic gap a likely location for future earthquakes. Empirical Green's function and directivity analyses are also performed to constrain rupture kinematics of the mainshock using systematic azimuthal variations in relative source time functions. Results indicate rupture progressed mainly to the northwest within 15o of the direction of the

  7. Structural Characteristics and Origin of Boundary Fault Belts of the Gaoyou Sag in the Subei Basin%苏北盆地高邮凹陷边界断裂带构造特征及成因

    Institute of Scientific and Technical Information of China (English)

    王玺; 陈清华; 朱文斌; 马婷婷; 王晓蕾; 刘寅

    2013-01-01

    真武、吴堡断裂带是高邮凹陷的边界断裂带,具有复杂的结构和演化特征.通过三维地震资料解释以及断层平均活动速率的计算,分析了两断裂带在晚白垩世-新生代时期的几何学和运动学特征,将两断裂带作为一个整体,建立了凹陷边界主断裂发育的时空关系,对比探讨了两断裂带内各级断层的发育顺序和模式,并探讨了断层发育的成因.研究表明:一级断裂真①、吴①断层形成于泰州组沉积时期,阜四段沉积时期达到活动顶峰.二级断裂真②、吴②断层形成于阜四段沉积时期,戴南组沉积时期达到活动的顶峰.二级断裂主要形成于一级断裂沿走向的转折处,其延伸方向受控于区域早期NW-SE向伸展应力以及曲折边界条件;两断裂带内部断层发育模式有很大不同,认为其分别形成于伸展机制与斜滑机制下,与区域后期EW向挤压导致的郯庐断裂带右旋走滑作用有关.%As the boundary of the Gaoyou Sag, the Zhenwu and Wubao Fault Belts show complicated geometry and e-volution history. Based on 3D seismic interpretation and calculation of mean fault active rate, we analyze the geometric and kinematic characteristics of the two fault belts during Late Cretaceous-Quaternary and establish the temporal-spatial relationship of development of the main faults as a whole. We also investigate the development patterns and the formation processes of the two fault belts respectively. Our results show that the main boundary faults of the Gaoyou Sag were formed during the deposition of the Funing and Dainan Formations and might have been related to the NW-trending subduction of the paleo-Pacific Plate, which caused the NW-SE trending regional extension in East China. In particular, the trends and the formation patterns of the Zhen②Wu② and Ji3 Faults are related to the boundary conditions. We also infer that the Zhenwu and Wubao Fault Belts are formed through different

  8. Abrupt strike-slip fault to subduction transition: The Alpine Fault-Puysegur Trench connection, New Zealand

    Science.gov (United States)

    Lebrun, Jean-FréDéRic; Lamarche, Geoffroy; Collot, Jean-Yves; Delteil, Jean

    2000-08-01

    Swath bathymetry and other geophysical data collected over the Fiordland Margin, southwest of New Zealand are used to investigate the mechanism of transform-subduction transition between the Alpine Fault and the Puysegur Trench, two segments of the Pacific-Australian plate boundary. In this region the Cenozoic Southeast Tasman Basin, which obliquely underthrusts Fiordland at the Puysegur Trench, is separated from the Cretaceous Tasman Basin by the Resolution Ridge System, a major lithospheric discontinuity of the downgoing plate. Interpretation of seafloor morphology shows that the Alpine Fault extends offshore along the Fiordland coast and splits into West and East Branches. The West Branch cuts obliquely across the margin and connects sharply to the Puysegur subduction front at the northeastern tip of the Resolution Ridge System. Earthquake and seismic reflection data indicate that the West Branch is genetically controlled by downgoing plate structures associated with the Resolution Ridge System. Hence the West Branch is interpreted as the surface trace of the plate boundary segment extending between the Alpine Fault and the Puysegur Trench. We conclude that the development of the strike-slip segment of the plate boundary and its sharp transition to the Puysegur subduction are controlled by inherited structures of the Australian plate. Furthermore, according to geophysical data presented here, a tearing of the downgoing plate can be interpreted beneath the West Branch. A review of geophysical data along the region of the Alpine Fault-Hikurangi Trough, northeast New Zealand, shows a progressive transform-subduction transition that is accommodated by motion partitioning between the subduction interface and strike-slip faults. This transition is accounted for by an interplate coupling that progressively increases toward the Alpine Fault in relation with a gradual thickening of the downgoing crust. The comparison between the Fiordland and the Hikurangi strike

  9. The mechanics of gravity-driven faulting

    OpenAIRE

    L. Barrows; V. Barrows

    2010-01-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic reb...

  10. Seismicity as a key to Understanding the Dead Sea Transform Fault - Results From a Temporary Dense Seismic Network in the Southern Dead Sea Basin

    Science.gov (United States)

    Braeuer, B.; Weber, M. H.; Asch, G.; Haberland, C. A.; Hofstetter, A.; El-Kelani, R.; Darwish, Y.

    2009-12-01

    Knowledge of the seismicity distribution gives a great contribution to understand the processes at transform faults. The analysis of the regional network catalog (Begin & Steinitz, 2005) could not produce a clear image of the distribution of the seismicity. Furthermore, the seismic energy release over the 20 years suggests a continuous decrease of the seismic activity. Therefore, a very dense (station distance 2 - 5km) local seismological network was operated in the southern Dead Sea area within the framework of the international project DESIRE (Dead Sea Integrated Research Project). During its operation time more than 500 local events were registered, which is about five times more than previously estimated. These events give a detailed picture of the distribution of seismicity. The mainly microseismic activity is generally concentrated on the eastern and western faults limiting the Dead Sea basin (DSB). Most of the seismic events occurred in the uppermost 15 km, while the overall depth limit was at 30km. One of the dominant features observed in the dataset was a cluster of 115 earthquakes, occurring in February 2007. For precise relative locations of the events in the cluster Double-Difference location HypoDD (Waldhauser 2001) procedure was applied. We observe a vertical distribution of the events in the cluster. Very shallow events are found in the center of the study area. They are related to activity of the Lisan salt dome beneath that area. Furthermore, the local events were used to refine the picture of the P- and S- wave velocity distribution.

  11. Subsurface imaging in a sector of Cerro Prieto transform fault near to pull-apart basin, Mexicali Valley, Baja California, Mexico, based on crooked lines 2D seismic reflection.

    Science.gov (United States)

    Mares-Agüero, M. A.; González-Escobar, M.; Arregui, S.

    2016-12-01

    In the transition zone between San Andres continental transformation system and the coupled transform faults system and rifting of Gulf of California is located the Cerro Prieto pull-apart basin delimitated by Imperial fault (northeast) and Cerro Prieto fault (CPF) (southwest), this last, is the limit west of Cerro Prieto geothermic field (CPGF). Crooked lines 2D seismic reflection, covering a portion near the intersection of CPF and CPGF are processed and interpreted. The seismic data were obtained in the early 80's by Petróleos Mexicanos (PEMEX). By decades, technical and investigation works in Cerro Prieto geothermic field and its vicinity had mapped faults at several depths but do not stablish a clear limit where this faults and CPF interact due the complex hydrothermal effects imaging the subsurface. The profiles showing the presence of a zone of uplift effect due to CPF. Considering the proximity of the profiles to CPF, it is surprising almost total absence of faults. A strong reflector around 2 km of depth, it is present in all profiles. This seismic reflector is considered a layer of shale, result of the correlation with a well located in the same region.

  12. 功率谱逆变换对数在齿轮箱故障诊断中的应用%Application of Logarithm of Fourier Inverse Transform of Signal Power Spectrum in Gearbox Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    According to the nature and characteristic of frequency spectrum analysis ,this paper puts forward applying frequency spectrum analysis method to gearbox fault diagnosis ,for improving the signal-to-noise ratio in fault diagnosis .The feasibility of using the logarithm of Fourier inverse transform of signal power spectrum in gear box fault diagnosis is verified , and the characteristics of gear box fault are obtained .%  根据频谱分析的性质和特点,提出在故障诊断中提高信噪比的频谱分析方法。将功率谱傅里叶逆变换对数应用在齿轮箱故障诊断中,并分析了齿轮箱的故障特征。

  13. 变压器几种常见故障产生原因和其处理方法解析%Several Common Causes of Transformer Fault and Its Processing Method Analysis

    Institute of Scientific and Technical Information of China (English)

    宋加波

    2015-01-01

    The factors affected by the transformer structure, process, operation mode, transformer failure often occurs in the process of operation, which have a great impact on normal operation of transformer. Through the analysis and the causes of common faults of transformer in operation, put forward the corresponding fault processing method.%受变压器结构、工艺、运维方式等因素的影响,变压器在运行过程中经常发生故障,这对变压器的正常运行有很大的影响。通过分析变压器运行中的常见故障及其产生原因,提出了相应的故障处理方法。

  14. TRANSFORMATION

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  15. Transformation

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....

  16. Transformation

    DEFF Research Database (Denmark)

    Peters, Terri

    2011-01-01

    Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi.......Artiklen diskuterer ordet "transformation" med udgangspunkt i dels hvorledes ordet bruges i arkitektfaglig terminologi og dels med fokus på ordets potentielle indhold og egnethed i samme teminologi....

  17. Crystallography and morphology of antiphase boundary-like structure induced by martensitic transformation in Ti–Pd–Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, M., E-mail: matsuda@alpha.msre.kumamoto-u.ac.jp [Department of Materials Science and Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Nishimura, S.; Tsurekawa, S.; Takashima, K. [Department of Materials Science and Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Mitsuhara, M.; Nishida, M. [Department of Engineering Sciences for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2015-01-05

    Highlights: • The APB-like structure are observed in both 9R and B19 martensite of Ti–Pd–Fe alloy. • Atomic displacement on APB-like structure reflects the microdomain by pre-martensite. • The density of APB-like contrasts are affected by Fe content in Ti–Pd–Fe alloy. - Abstract: The antiphase boundary (APB)-like structure of both 9R and B19 martensites in the Ti–Pd–Fe alloy was investigated by means of transmission electron microscopy. Some APB-like structures with curved and wide contrasts along the (0 0 1){sub 9R} basal plane are observed in 9R martensitic plates. The atomic displacement on the APB-like structure reflects the atomic movement stemming from the microdomains formed as a pre-martensitic transformation. The displacement vector of the APB-like structure in the B19 martensite can be expressed as R = 〈1/3 0 −1/2〉{sub B19}. The density of APB-like contrasts increases by the substitution of Fe for Pd in Ti–Pd–Fe alloy.

  18. Identification of Transient and Permanent Faults

    Institute of Scientific and Technical Information of China (English)

    李幼仪; 董新洲; 孙元章

    2003-01-01

    A new algorithm was developed for arcing fault detection based on high-frequency current transients analyzed with wavelet transforms to avoid automatic reclosing on permanent faults. The characteristics of arc currents during transient faults were investigated. The current curves of transient and permanent faults are quite similar since current variation from the fault arc is much less than the voltage variation. However, the fault current details are quite different because of the arc extinguishing and reigniting. Dyadic wavelet transforms were used to identify the current variation since wavelet transform has time-frequency localization ability. Many electric magnetic transient program (EMTP) simulations have verified the feasibility of the algorithm.

  19. TRANSMISSION LINE FAULT ANALYSIS USING WAVELET THEORY

    Directory of Open Access Journals (Sweden)

    Ravindra Malkar

    2012-06-01

    Full Text Available This paper describes a Wavelet transform technique to analyze power system disturbance such as transmission line faults with Biorthogonal and Haar wavelets. In this work, wavelet transform based approach,which is used to detect transmission line faults, is proposed. The coefficient of discrete approximation of the dyadic wavelet transform with different wavelets are used to be an index for transmission line fault detection and faulted – phase selection and select which wavelet is suitable for this application. MATLAB/Simulation is used to generate fault signals. Simulation results reveal that the performance of the proposed fault detection indicator is promising and easy to implement for computer relaying application.

  20. Geodetic estimates of fault slip rates in the San Francisco Bay area

    Science.gov (United States)

    Savage, J. C.; Svarc, J. L.; Prescott, W. H.

    1999-03-01

    Bourne et al. [1998] have suggested that the interseismic velocity profile at the surface across a transform plate boundary is a replica of the secular velocity profile at depth in the plastosphere. On the other hand, in the viscoelastic coupling model the shape of the interseismic surface velocity profile is a consequence of plastosphere relaxation following the previous rupture of the faults that make up the plate boundary and is not directly related to the secular flow in the plastosphere. The two models appear to be incompatible. If the plate boundary is composed of several subparallel faults and the interseismic surface velocity profile across the boundary known, each model predicts the secular slip rates on the faults which make up the boundary. As suggested by Bourne et al., the models can then be tested by comparing the predicted secular slip rates to those estimated from long-term offsets inferred from geology. Here we apply that test to the secular slip rates predicted for the principal faults (San Andreas, San Gregorio, Hayward, Calaveras, Rodgers Creek, Green Valley and Greenville faults) in the San Andreas fault system in the San Francisco Bay area. The estimates from the two models generally agree with one another and to a lesser extent with the geologic estimate. Because the viscoelastic coupling model has been equally successful in estimating secular slip rates on the various fault strands at a diffuse plate boundary, the success of the model of Bourne et at. [1998] in doing the same thing should not be taken as proof that the interseismic velocity profile across the plate boundary at the surface is a replica of the velocity profile at depth in the plastosphere.

  1. Analysis and Treatment of Abnormal Chromatographic Result Fault in 220kV Main Transformer%一台220kV主变色谱异常故障的分析及处理

    Institute of Scientific and Technical Information of China (English)

    孔祥凤; 李进

    2012-01-01

    The abnormal chromatographic result in 220kV main transformer is analyzed. The fault position is diagnosed based on electric test results.%对220kV主变色谱异常结果进行了分析,结合电气试验对故障的位置进行了判断。

  2. TRANSFORMER

    Science.gov (United States)

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  3. 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, U.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.

  4. Effect of lateral boundary perturbations on the breeding method and the local ensemble transform Kalman filter for mesoscale ensemble prediction

    Directory of Open Access Journals (Sweden)

    Kazuo Saito

    2012-01-01

    Full Text Available The effect of lateral boundary perturbations (LBPs on the mesoscale breeding (MBD method and the local ensemble transform Kalman filter (LETKF as the initial perturbations generators for mesoscale ensemble prediction systems (EPSs was examined. A LBPs method using the Japan Meteorological Agency's (JMA's operational one-week global ensemble prediction was developed and applied to the mesoscale EPS of the Meteorological Research Institute for the World Weather Research Programme, Beijing 2008 Olympics Research and Development Project. The amplitude of the LBPs was adjusted based on the ensemble spread statistics considering the difference of the forecast times of the JMA's one-week EPS and the associated breeding/ensemble Kalman filter (EnKF cycles. LBPs in the ensemble forecast increase the ensemble spread and improve the accuracy of the ensemble mean forecast. In the MBD method, if LBPs were introduced in its breeding cycles, the growth rate of the generated bred vectors is increased, and the ensemble spread and the root mean square errors (RMSEs of the ensemble mean are further improved in the ensemble forecast. With LBPs in the breeding cycles, positional correspondences to the meteorological disturbances and the orthogonality of the bred vectors are improved. Brier Skill Scores (BSSs also showed a remarkable effect of LBPs in the breeding cycles. LBPs showed a similar effect with the LETKF. If LBPs were introduced in the EnKF data assimilation cycles, the ensemble spread, ensemble mean accuracy, and BSSs for precipitation were improved, although the relative advantage of LETKF as the initial perturbations generator against MDB was not necessarily clear. LBPs in the EnKF cycles contribute not to the orthogonalisation but to prevent the underestimation of the forecast error near the lateral boundary.The accuracy of the LETKF analyses was compared with that of the mesoscale 4D-VAR analyses. With LBPs in the LETKF cycles, the RMSEs of the

  5. Coalbed methane reservoir boundaries and sealing mechanism

    Institute of Scientific and Technical Information of China (English)

    SU Xianbo; LIN Xiaoying; LIU Shaobo; SONG Yan

    2005-01-01

    It is important to investigate the coalbed methane reservoir boundaries for the classification, exploration, and development of the coalbed methane reservoir.Based on the investigation of the typical coalbed methane reservoirs in the world, the boundaries can be divided into four types: hydrodynamic boundary, air altered boundary,permeability boundary, and fault boundary. Hydrodynamic and air altered boundaries are ubiquitous boundaries for every coalbed methane reservoir. The four types of the fault sealing mechanism in the petroleum geological investigation (diagen- esis, clay smear, juxtaposition and cataclasis) are applied to the fault boundary of the coalbed methane reservoir. The sealing mechanism of the open fault boundary is the same with that of the hydrodynamic sealing boundary.The sealing mechanism of the permeability boundary is firstly classified into capillary pressure sealing and hydrocarbon concentration sealing. There are different controlling boundaries in coalbed methane reservoirs that are in different geological backgrounds. Therefore, the coalbed methane reservoir is diversiform.

  6. Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform

    Science.gov (United States)

    Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

    2005-01-01

    Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

  7. Classification of fault diagnosis in a gear wheel by used probabilistic neural network, fast Fourier transform and principal component analysis

    Directory of Open Access Journals (Sweden)

    Piotr CZECH

    2007-01-01

    Full Text Available This paper presents the results of an experimental application of artificial neural network as a classifier of the degree of cracking of a tooth root in a gear wheel. The neural classifier was based on the artificial neural network of Probabilistic Neural Network type (PNN. The input data for the classifier was in a form of matrix composedof statistical measures, obtained from fast Fourier transform (FFT and principal component analysis (PCA. The identified model of toothed gear transmission, operating in a circulating power system, served for generation of the teaching and testing set applied for the experiment.

  8. Fault creep and strain partitioning in Trinidad-Tobago: Geodetic measurements, models, and origin of creep

    Science.gov (United States)

    Geirsson, Halldór; Weber, John; La Femina, Peter; Latchman, Joan L.; Robertson, Richard; Higgins, Machel; Miller, Keith; Churches, Chris; Shaw, Kenton

    2017-04-01

    We studied active faults in Trinidad and Tobago in the Caribbean-South American (CA-SA) transform plate boundary zone using episodic GPS (eGPS) data from 19 sites and continuous GPS (cGPS) data from 8 sites, then modeling these data using a series of simple screw dislocation models. Our best-fit model for interseismic fault slip requires: 12-15 mm/yr of right-lateral movement and very shallow locking (0.2 ± 0.2 km; essentially creep) across the Central Range Fault (CRF); 3.4 +0.3/-0.2 mm/yr across the Soldado Fault in south Trinidad, and 3.5 +0.3/-0.2 mm/yr of dextral shear on fault(s) between Trinidad and Tobago. The upper-crustal faults in Trinidad show very little seismicity (1954-current from local network) and do not appear to have generated significant historic earthquakes. However, paleoseismic studies indicate that the CRF ruptured between 2710 and 500 yr. B.P. and thus it was recently capable of storing elastic strain. Together, these data suggest spatial and/or temporal fault segmentation on the CRF. The CRF marks a physical boundary between rocks associated with thermogenically generated petroleum and overpressured fluids in south and central Trinidad, from rocks containing only biogenic gas to the north, and a long string of active mud volcanoes align with the trace of the Soldado Fault along Trinidad's south coast. Fluid (oil and gas) overpressure may thus cause the CRF fault creep that we observe and the lack of seismicity, as an alternative or addition to weak mineral phases on the fault.

  9. A High shear stress segment along the San Andreas Fault: Inferences based on near-field stress direction and stress magnitude observations in the Carrizo Plain Area

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, D. A., [Department of Geology and Geophysics, University of Adelaide (Australia); Younker, L.W. [Lawrence Livermore National Lab., CA (United States)

    1997-01-30

    Nearly 200 new in-situ determinations of stress directions and stress magnitudes near the Carrizo plain segment of the San Andreas fault indicate a marked change in stress state occurring within 20 km of this principal transform plate boundary. A natural consequence of this stress transition is that if the observed near-field ``fault-oblique`` stress directions are representative of the fault stress state, the Mohr-Coulomb shear stresses resolved on San Andreas sub-parallel planes are substantially greater than previously inferred based on fault-normal compression. Although the directional stress data and near-hydrostatic pore pressures, which exist within 15 km of the fault, support a high shear stress environment near the fault, appealing to elevated pore pressures in the fault zone (Byerlee-Rice Model) merely enhances the likelihood of shear failure. These near-field stress observations raise important questions regarding what previous stress observations have actually been measuring. The ``fault-normal`` stress direction measured out to 70 km from the fault can be interpreted as representing a comparable depth average shear strength of the principal plate boundary. Stress measurements closer to the fault reflect a shallower depth-average representation of the fault zone shear strength. If this is true, only stress observations at fault distances comparable to the seismogenic depth will be representative of the fault zone shear strength. This is consistent with results from dislocation monitoring where there is pronounced shear stress accumulation out to 20 km of the fault as a result of aseismic slip within the lower crust loading the upper locked section. Beyond about 20 km, the shear stress resolved on San Andreas fault-parallel planes becomes negligible. 65 refs., 15 figs.

  10. Age determination and development of experimental methods for quaternary fault and formation

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Kim, Jeong Min; Lee, S. H.; Han, J. H.; Shin, H. S.; Cheong, Y. J. [Korea Basic Science Institute, Daejeon (Korea, Republic of); Lee, H. S. [Pukyong National Univ., Busan (Korea, Republic of); Hong, D. G. [Kangwon National Univ., Gangneung (Korea, Republic of)

    2006-02-15

    Correlation of palaeo-shoreline elevations indicates that the MQt{sub 4} terrace in Suryum site has formed during MIS 5e, which is supported by stratigraphically concordant OSL ages for NQt{sub 3} terrace sediments in Yonghan area. Sedimentological features of the trench site of the Eupcheon fault suggest multiple fault movements during the Late Quaternary. All of these observations imply that uplift rate in the middle part of the coast has been much larger than that in the northern part during 125 ka {approx} 80 ka, requiring the revision of conventional view that the Korean peninsula is tectonically very stable. The ESR data suggest that the Ilkwang fault zone has been formed by the initial surface fault activity at 2-3 Ma and reactivated at least 4 times at 1.2-1.3 Ma, 1 Ma, 0.6 Ma and 0.5 Ma, with part of adjacent NNE and NE trending faults. The Eupcheon fault has been reactivated along the boundary between fault breccia originated from Cretaceous sedimentary rocks and Tertiary lithic tuff at around 2 Ma, 1.3 Ma, and 1 Ma. It has been reactivation again along the boundary between Cretaceous sandstone and fault breccia at 0.8 Ma, and between fault breccia and Tertiary lithic tuff at 0.6 Ma. During the late Quaternary after MIS 5e, the Eupcheon fault reactivated along the boundary between fault gouges, cutting Quaternary marine terrace deposits. The ESR data for the Eupcheon fault, however, should be carefully reexamined because it is probable that the samples contain clay components of weathering, not cataclastic origin. A weathering profile developed in the Suryum site was disturbed by tectonic movement that appears to be a simple one-time reverse faulting event based on field observations. A comparative analysis of the mineralogy, micromorphology, and chemistry of the weathering profile and fault gouge, however, reveals that both the microfissures in the deformed weathering profile and larger void spaces along the fault plane were filled with multi

  11. Combinational Diagnosis for Transformer Faults Based on Multi-models%基于多模型的变压器故障组合诊断研究

    Institute of Scientific and Technical Information of China (English)

    赵文清; 李庆良; 王德文

    2013-01-01

    Diagnose of power transformer fault is important for normal operation of power system, consequently, combining multiple Bayes classification algorithms, we proposed an assembled model on the basis of support vector machine. During the diagnosis process, firstly, 12 key relative attributes of dissolved gases were selected as inputs of the diagnosis model, and sample data set was obtained after data preprocessing on the attributes. Secondly, according to 13 fault types, the sample data set was diagnosed using a model group formed by several single diagnosis methods, such as naive Bayes model, belief network augmented naive Bayes, semi-naive Bayesian model, and tree augmented naive Bayes model. Thirdly, the diagnosis results were set to be the input of a support vector machine diagnosis model, and then a changeable weights combination diagnosis model was obtained. Furthermore, the procedure and parameters of the proposed combinational diagnosis were discussed in detail. According to comparison with other diagnosis methods, the proposed combinational fault diagnosis model has higher diagnosis accuracy than single model and other common combinational models. Moreover, two practical examples on dissolved gas data of transformers prove the validity and show that this model is effective. Therefore, the proposed model can be adopted in practical projects.%变压器故障诊断是保证整个电力系统正常运行的重要部分,为此提出了一个基于支持向量机并与多种贝叶斯分类算法相结合的组合诊断模型.诊断过程中,首先通过相关统计分析,选择典型油中气体的12个相关属性值作为模型的输入参数,并对其进行数据预处理,生成一次样本.其次,按照变压器常见的13种故障类型,利用多个单一诊断方法如朴素贝叶斯模型、半朴素贝叶斯模型、增强的朴素贝叶斯模型和贝叶斯网络增强模型构成诊断模型群,对一次样本数据进行诊断.最后,把贝叶斯诊断

  12. A method of online monitoring of transformer fault%变压器故障在线监测的一种方法

    Institute of Scientific and Technical Information of China (English)

    林伟哲; 周伟波

    2015-01-01

    变压器油中气体在线监测技术是以油中溶解气体为监测对象,应用该技术可及时掌握变压器的运行状况,发现和跟踪存在的潜伏性故障。配合计算机系统对故障进行诊断,可以避免部分灾难性事故,实现状态检修、降低维护成本、提高自动化程度,提高变电站运行管理水平。使用开源软件开发了在线监测软件,该软件具有模块化及安全、灵活的数据库操作和跨平台特性,经实验检验达到了设计的目标。%The monitoring technology of gas in oil in the transformer takes the dissolved gases in oil as the monitoring object. The operating condition of the transformer can be monitored timely to discover and track the presence of latent failures. Some catastrophic accident can be prevented with the computer system fault diagnosis, realizing condition-based maintenance, reducing maintenance costs and increasing the degree of automation and improving operational management of the substation. Online monitoring softwareis developed using the open source software, which is modular, has secure, flexible database operations and cross-platform features.The experiment showed that it can satisfy the design goal.

  13. Earthquake cycle on the Ballenas Fault, Central Gulf of California, MX

    Science.gov (United States)

    Malservisi, R.; Plattner, C.; Hackl, M.; Gonzalez-Garcia, J. J.; Suarez Vidal, F.; Amelung, F.; Dixon, T. H.

    2009-12-01

    South of the San Andreas Fault system, ~90% of the North America/Pacific plate motion is accommodate along the Gulf of California. Here the plate boundary deformation is partitioned in deep basins, often resulting in formation of new oceanic crust, connected by long transform faults. In the central part of the Gulf, one of these transform fault, the Ballenas fault, is localized in the Canales de Ballenas, a ~30 km wide channel between Isla Angel de la Garda and mainland Baja California. The presence of land on both the sides of this marine transform fault give the unique opportunity to perform geodetic study across its trace. On August 3rd 2009, a series of seismic strike slip events (including a M6.9) happened along this segment of plate boundary allowing a combined study of co- and inter- seismic deformation. Here we present the results from 5 years of EGPS along two transects perpendicular to the plate motion direction at 29 and 28 degrees North. These surveys include at least 3 occupations before the seismic event and at least 1 occupation after the earthquake. The analysis of the inter-seismic data shows that ~46 mm/yr is accommodated within the Canales de Ballenas. Co-seismic data are being collected at the time of the deadline for this abstract and will be presented at the meeting in combination with InSar signal.

  14. 基于静态小波变换的T型输电线路行波测距方法%Travelling Wave Fault Location for Three-Terminal Transmission ~Line Based on Static Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    张永健; 胥杰; 孙嘉

    2012-01-01

    In view of the defect in existing travelling wave fault location algorithm that this algorithm is easily affected by wave velocity, a new method for travelling wave fault location of three-terminal transmission line is proposed. Using Clarke's transform the phase currents are turned into independent mode currents, then static wavelet transform (SWT) is applied to mode currents to determine the moments at which travelling wave surges arrive the bus terminals. Firstly the memberships are defined by three initial moments at which the first wave front arrives T-connected buses, and based on the memberships the criterion for distinguishing faulty branch is given. To implement fault location of three-terminal transmission line, based on existing fault location formula for two-terminal transmission line the fault location formula for three-terminal transmission line is derived. Three possible fault conditions near the T-connected node are researched, and a three-time fault location method is put forward to resolve the fault location for the faults occurred near the T-connected node. Comparing with existing fault location methods, due to time-invariance of SWT, making full use of the data measured at three terminals of the three-terminal transmission line and that the wave velocity does not appear in the derived fault location formula, the proposed method can provide more accurate fault location results. Results of simulation using ATP/EMTP show that the proposed fault location method for three-terminal transmission line is simple, reliable and not affected by such factors as transition resistance and fault types and so on.%针对现有T型输电线路行波测距算法易受行波波速影响的不足,提出一种新的T型输电线路行波测距方法。采用Clarke变换将相电流转换为独立的模电流,对模电流进行静态小波变换(staticwavelettransform,SwT)处理,实现各行波浪涌到达各母线端时刻的标定。首先利用

  15. Fault Estimation

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...... problems can be solved by standard optimization tech-niques. The proposed methods include: (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; (2) FE for systems with parametric faults, and (3) FE for a class of nonlinear systems.......This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis...

  16. Investigating fault coupling: Creep and microseismicity on the Hayward fault

    Science.gov (United States)

    Evans, E. L.; Loveless, J. P.; Meade, B. J.; Burgmann, R.

    2009-12-01

    We seek to quantify the relationship between interseismic slip activity and microseismicity along the Hayward fault in the eastern San Francisco Bay Area. During the interseismic regime the Hayward fault is known to exhibit variable degrees of locking both along strike and down-dip. Background microseismicity on and near the fault has been suggested to provide independent information about the rates of interseismic creep and the boundaries of creeping regions. In particular, repeating earthquakes within the fault zone have been suggested as a proxy for fault creep rates. To investigate this relationship, we invert GPS data for microplate rotations, fault slip rates, and fault coupling using a block model that spans western United States and includes the San Andreas, Hayward, Calaveras, Rogers Creek, and Green Valley faults in the greater Bay area. The tectonic context provided by the regional scale model ensures that the slip budget across Bay Area faults is consistent with large scale tectonic motions and kinematically connected to the central San Andreas fault. We image the spatial distribution of interseismic slip on a triangulated mesh of the Hayward fault and compare the distribution of interseismic fault coupling with the number of earthquakes and the moment rate of all on-fault seismicity. We quantitatively test the hypothesis that microseismicity might define the transitions between locked and creeping regions. The calculated correlations are tested against a null hypothesis that microseismicity is randomly distributed. We further extend this investigation to the step over region between the Hayward and Calaveras faults to illuminate the interactions between linking faults.

  17. 基于系统辨识的阻抗匹配平衡变压器故障诊断%Fault Diagnosis of Impedance Matching Balance Transformer Based on System Identification

    Institute of Scientific and Technical Information of China (English)

    李龙; 余楚中; 王鹏飞

    2011-01-01

    Impedance matching balance transformer is tion substation transformer. In order to solve the puzzle often used as the main electrified railway tracthat could not accurately identify the failure in internal or external impedance matching transformer by traditional fauh diagnosis method, based on that the winding resistance and short circuit reactance value have not been changed in normal opera- tion for impedance matching balance transformer or external fault, the paper proposed an identification algorithm of recursive least square parameter estimation on line to distinguish the fault. The curve of experimental simulation demonstrated that it could effectively distinguish to be internal failure or external fault. The research result shows its feasibility to distinguish two sorts of different faults.%阻抗匹配平衡变压器常被用作电气化铁道牵引变电所的主变压器。为解决传统故障诊断方式难以准确鉴别该变压器内外故障,基于正常运行或发生外部故障时绕组电阻和短路电抗值不产生变化,而当出现内部故障时将产生变化的问题,提出了利用最小二乘参数估计递推算法在线辨识其变化以鉴别内外故障。实验仿真曲线证实了采用该算法能有效区分其内外故障,研究结果验证了用该方法鉴别2种不同类型故障的可行性。

  18. Evolution of the Rodgers Creek–Maacama right-lateral fault system and associated basins east of the northward-migrating Mendocino Triple Junction, northern California

    Science.gov (United States)

    McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Wagner, David L.; Fleck, Robert J.; Langenheim, V.E.; Jachens, Robert C.; Clahan, Kevin; Allen, James R.

    2012-01-01

    The Rodgers Creek–Maacama fault system in the northern California Coast Ranges (United States) takes up substantial right-lateral motion within the wide transform boundary between the Pacific and North American plates, over a slab window that has opened northward beneath the Coast Ranges. The fault system evolved in several right steps and splays preceded and accompanied by extension, volcanism, and strike-slip basin development. Fault and basin geometries have changed with time, in places with younger basins and faults overprinting older structures. Along-strike and successional changes in fault and basin geometry at the southern end of the fault system probably are adjustments to frequent fault zone reorganizations in response to Mendocino Triple Junction migration and northward transit of a major releasing bend in the northern San Andreas fault. The earliest Rodgers Creek fault zone displacement is interpreted to have occurred ca. 7 Ma along extensional basin-forming faults that splayed northwest from a west-northwest proto-Hayward fault zone, opening a transtensional basin west of Santa Rosa. After ca. 5 Ma, the early transtensional basin was compressed and extensional faults were reactivated as thrusts that uplifted the northeast side of the basin. After ca. 2.78 Ma, the Rodgers Creek fault zone again splayed from the earlier extensional and thrust faults to steeper dipping faults with more north-northwest orientations. In conjunction with the changes in orientation and slip mode, the Rodgers Creek fault zone dextral slip rate increased from ∼2–4 mm/yr 7–3 Ma, to 5–8 mm/yr after 3 Ma. The Maacama fault zone is shown from several data sets to have initiated ca. 3.2 Ma and has slipped right-laterally at ∼5–8 mm/yr since its initiation. The initial Maacama fault zone splayed northeastward from the south end of the Rodgers Creek fault zone, accompanied by the opening of several strike-slip basins, some of which were later uplifted and compressed

  19. Apparent stress, fault maturity and seismic hazard for normal-fault earthquakes at subduction zones

    Science.gov (United States)

    Choy, G.L.; Kirby, S.H.

    2004-01-01

    The behavior of apparent stress for normal-fault earthquakes at subduction zones is derived by examining the apparent stress (?? a = ??Es/Mo, where E s is radiated energy and Mo is seismic moment) of all globally distributed shallow (depth, ?? 1 MPa) are also generally intraslab, but occur where the lithosphere has just begun subduction beneath the overriding plate. They usually occur in cold slabs near trenches where the direction of plate motion across the trench is oblique to the trench axis, or where there are local contortions or geometrical complexities of the plate boundary. Lower ??a (tectonic regime suggests that the level of ?? a is related to fault maturity. Lower stress drops are needed to rupture mature faults such as those found at plate interfaces that have been smoothed by large cumulative displacements (from hundreds to thousands of kilometres). In contrast, immature faults, such as those on which intraslab-normal-fault earthquakes generally occur, are found in cold and intact lithosphere in which total fault displacement has been much less (from hundreds of metres to a few kilometres). Also, faults on which high ??a oceanic strike-slip earthquakes occur are predominantly intraplate or at evolving ends of transforms. At subduction zones, earthquakes occurring on immature faults are likely to be more hazardous as they tend to generate higher amounts of radiated energy per unit of moment than earthquakes occurring on mature faults. We have identified earthquake pairs in which an interplate-thrust and an intraslab-normal earthquake occurred remarkably close in space and time. The intraslab-normal member of each pair radiated anomalously high amounts of energy compared to its thrust-fault counterpart. These intraslab earthquakes probably ruptured intact slab mantle and are dramatic examples in which Mc (an energy magnitude) is shown to be a far better estimate of the potential for earthquake damage than Mw. This discovery may help explain why loss of

  20. Technology for Boundaries

    DEFF Research Database (Denmark)

    Bødker, Susanne; Kristensen, Jannie Friis; Nielsen, Christina

    2003-01-01

    This paper presents a study of an organisation, which is undergoing a process transforming organisational and technological boundaries. In particular, we shall look at three kinds of boundaries: the work to maintain and change the boundary between the organisation and its customers; boundaries.......After analysing the history and the current boundary work, the paper will propose new technological support for boundary work. In particular the paper will suggest means of supporting boundaries when these are productive and for changing boundaries when this seems more appropriate. In total, flexible technologies...... seem a core issue when dealing with technology for boundaries....

  1. Research on System of Power Transformer Fault Diagnosis Based on WSN and Data Fusion Technology%基于WSN和数据融合技术的电力变压器故障诊断系统的研究

    Institute of Scientific and Technical Information of China (English)

    邵开丽; 王鸿运

    2012-01-01

    The article discusses a method of power transformer fault diagnosis based on data fusion and extension theory, for this method a power transformer fault diagnosis system is constructed and developed by the application of wireless sensor network technology and VS. NET platform. The system applies WSN technology in wireless data acquisition of gases dissolved in power transformer oil, and can achieve real time data transmission. At the same time information fusion technology which is used to optimize the data, not only can reduce network energy consumption and ensure the accurate and objective data. For the coding rules of gas ratio method currently existed is incomplete and single, the extension method, combining quantitative and qualitative, it can make transformer fault diagnosis more refinement. Especially, the visual system can achieve the acquisition, displaying, analysis, storage and playback of gas parameters, and can be used in real-time analyzing and automatic diagnosis of transformer fault. The system of power transformer fault diagnosis can not only resolve the problem of the real-time and remote monitoring of operating personnel , but also greatly improve the performance of the transformer fault diagnosis. It provides a new direction for transformer online monitoring and fault diagnosis technology.%探讨一种基于数据融合和可拓理论的电力变压器故障诊断方法,基于此方法,应用无线传感器网络技术和.NET开发平台构建和开发出一套电力变压器故障诊断系统.该系统将WSN技术用于电力变压器油中溶解气体的无线数据采集,实现变压器油中溶解气体的实时数据采集和传送;同时运用信息融合技术对数据进行优化处理,既可以降低网络能耗又保证了数据的准确和客观;在变压器进行故障诊断时,针对现有电力变压器故障诊断的气体比值法存在的编码规则不完整、诊断故障类型单一等缺陷,使用可拓诊断方法,定

  2. Analysis of the Action of the Fault Protection Action of Multiple Main Transformers in the Circuit Fault%一起线路故障引起多台主变间隙保护动作跳闸事故的分析

    Institute of Scientific and Technical Information of China (English)

    赵亨奎

    2015-01-01

    In order to limit the short-circuit current, and to ensure that the size and distribution of the zero sequence current in the system is not affected by the operation mode of the system, when the single-phase grounding fault and the neutral point is lost, the neutral point of the transformer will be zero sequence voltage or zero sequence current. In this paper, we analyze the causes of the protection action of the main transformer gap protection action caused by the fault of the main transformer and the protection of the ground fault.%为了限制短路电流,并保证系统中零序电流的大小和分布不受系统运行方式变化的影响,当电网发生单相接地故障且失去中性点时,不接地的变压器中性点将出现零序电压或零序电流.针对一起线路接地故障造成的主变间隙保护动作跳闸事故,分析了该间隙保护动作的原因,并对间隙保护相关的整定和配合的问题进行了探究.

  3. A Pore Fluid Study in the Transform Fault System of Western Haiti: Investigating Geochemical Processes and Hydrologic Pathways of the Fluids

    Science.gov (United States)

    Battani, A.; Monnin, C.; Ruffine, L.; Ellouz, N.; Leroy, S. D.

    2014-12-01

    The area of Western Haiti is located between the Enriquillo-Plantain Garden Fault (EPGF) and Ciabao-Oriente Septentrional fault systems. It has been investigated during the Haiti-SIS cruise (November-December 2012) by heat flow measurements and coring. These two strike-slip fault systems accommodate the relative motion between the Caribbean and North American plates. An aftershock study of the MW= 7, 12 January 2010 earthquake indicated that this event originated along the EPGF fault, while the septentrional fault has not been ruptured for about a century. We focused coring operations on specific zones; faults, basin margins, ridge, deep basins delimated using structural/sedimentological surface data. The objective of the pore-fluid study was to determine both the pathways of the fluids and their origin in relation with the fault activity. A total of 14 Kullenberg cores were collected for fluid sampling and sedimentological analyses. Overall, 99 pore fluids were extracted, using Rhizon® samplers. Major and minor dissolved elements were analyzed. The resulting dataset allows us to identify several diagenetic processes occurring within the upper section of the sedimentary column. For the fault-crossing zones, the vertical chloride and sulphate profiles where the dissolved-element concentrations are close to that of normal seawater suggest seawater downward flow (infiltration). There the faults would then act as recharge zones for fluid circulation. On the opposite, for cores recovered in the basins, dissolved element profiles exhibit variable shapes with sulfate concentration decreasing with depth (indicating organic matter oxydation or anaerobic oxidation of methane) These results will be combined with those from the emerged segment of the EPGF (that can be observed on land in Haiti) in order to have a picture of the hydrologic regime of the fault system, its capacity to act as a recharge zone and conversely to supply deep-seated fluids to the surface (discharge

  4. The Formation of Crystal Defects in a Fe-Mn-Si Alloy Under Cyclic Martensitic Transformations.

    Science.gov (United States)

    Bondar, Vladimir I; Danilchenko, Vitaliy E; Iakovlev, Viktor E

    2016-12-01

    Formation of crystalline defects due to cyclic martensitic transformations (CMT) in the iron-manganese Fe-18 wt.% Mn-2 wt.% Si alloy was investigated using X-ray diffractometry. Conditions for accumulation of fragment sub-boundaries with low-angle misorientations and chaotic stacking faults in crystal lattice of austenite and ε-martensite were analyzed.

  5. Transforming the representation of the boundary layer and low clouds for high-resolution regional climate modeling: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hsin-Yuan; Hall, Alex

    2013-07-24

    Stratocumulus and shallow cumulus clouds in subtropical oceanic regions (e.g., Southeast Pacific) cover thousands of square kilometers and play a key role in regulating global climate (e.g., Klein and Hartmann, 1993). Numerical modeling is an essential tool to study these clouds in regional and global systems, but the current generation of climate and weather models has difficulties in representing them in a realistic way (e.g., Siebesma et al., 2004; Stevens et al., 2007; Teixeira et al., 2011). While numerical models resolve the large-scale flow, subgrid-scale parameterizations are needed to estimate small-scale properties (e.g. boundary layer turbulence and convection, clouds, radiation), which have significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. To represent the contribution of these fine-scale processes to the resolved scale, climate models use various parameterizations, which are the main pieces in the model that contribute to the low clouds dynamics and therefore are the major sources of errors or approximations in their representation. In this project, we aim to 1) improve our understanding of the physical processes in thermal circulation and cloud formation, 2) examine the performance and sensitivity of various parameterizations in the regional weather model (Weather Research and Forecasting model; WRF), and 3) develop, implement, and evaluate the advanced boundary layer parameterization in the regional model to better represent stratocumulus, shallow cumulus, and their transition. Thus, this project includes three major corresponding studies. We find that the mean diurnal cycle is sensitive to model domain in ways that reveal the existence of different contributions originating from the Southeast Pacific land-masses. The experiments suggest that diurnal variations in circulations and thermal structures over this region are influenced by convection over the Peruvian sector of the Andes cordillera, while

  6. Diagnosis of an Overheat and Oil-leakage Fault of 10 kV Main Side Transformer Bushing%一起10 kV侧主变套管过热及漏油故障的诊断

    Institute of Scientific and Technical Information of China (English)

    赵晓东; 张登宇

    2014-01-01

    The infrared diagnostic technology, which can be used rapidly and in real time to realize the on-line monitoring and diagnosis of most power equipment faults, can early detect equipment defects for taking measures in advance to prevent the power outages caused by equipment malfunction, so, it is one of the effective measures of making the state inspection of power equipment under the charged condition. This paper introduces an overheat and oil-leakage fault of 10 kV main side transformer bushing that was found in time through infrared diagnostic technology. The expanding of the equipment fault was avoided through the diagnosis and analysis on the equipment fault.%红外诊断技术能快速实时地在线监测和诊断电力设备的大多数故障,能及早发现设备缺陷,以提前采取措施,防止设备出现故障造成停电,是电力设备带电条件下进行状态检测的有效手段之一。介绍了一例通过红外诊断技术及时发现的主变10 kV套管过热故障,通过对该故障的诊断分析,避免了设备故障的扩大。

  7. Hadamard Transforms

    CERN Document Server

    Agaian, Sos; Egiazarian, Karen; Astola, Jaakko

    2011-01-01

    The Hadamard matrix and Hadamard transform are fundamental problem-solving tools in a wide spectrum of scientific disciplines and technologies, such as communication systems, signal and image processing (signal representation, coding, filtering, recognition, and watermarking), digital logic (Boolean function analysis and synthesis), and fault-tolerant system design. Hadamard Transforms intends to bring together different topics concerning current developments in Hadamard matrices, transforms, and their applications. Each chapter begins with the basics of the theory, progresses to more advanced

  8. Active Fault Research (1996); Katsudanso kenkyu (1996)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-25

    This is a general collection of papers dealing with the research of active faults. In Japan, since very heavy damage was produced by the Hyogoken-Nambu earthquake of January, 1955, discussion of active faults has promptly grown very active. In relation to the said earthquake, detailed maps of earthquake faults that emerged in the same, trench investigations of the Awajishima surface fault rupture related to the same, and the circumstances of the southern and northern ends of the Nojima earthquake fault are reported. Discussion is made about the re-examination of precaution faults and the possibility of the presence of C-class active faults, dealing with the entirety of Japan. Itemized discussion covers the fossil liquefaction observed on the campus of Hokkaido University, fault outcrop at the geological boundary west of Hanamaki and at the western edge of the Kitakami lowland, morphology at the Median Tectonic Line active fault system Iyo fault, fault outcrop discovered at the Iwakuni active fault system Otake fault, and the Kokura Higashi fault and the topography surrounding it (northern part of Kyushu) are introduced. Furthermore, there are reports on the F1 fault and neotectonics in the Tan-Lu fracture zone in the Linyi area, Shandong Province, eastern part of China.

  9. 基于小波变换的鼠笼式异步电动机故障诊断%Research on Squirrel-cage Asynchronous Motor Fault Diagnosis Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    成函

    2015-01-01

    Wavelet Transform has a good localization capability in the time domain and frequency domain , especially being sensitive to the mutation point of the signal . Due to the multiresolution properties , it can be close to the spectrum , and has outstanding effect on Extraction of fault signal . This paper discussed wavelet analysis and its application in fault diagnosis , and verified the accuracy of the detection method of wavelet transform in squirrel-cage asynchronous motor fault .%小波变换在时域和频域都具有良好的局部化能力,尤其是对信号的突变点很敏感,其多分辨率性质可逼近细化频谱,对故障信号提取有突出的作用。本文通过算例论述了小波分析在故障诊断中的研究和应用,验证了小波变换方法检测鼠笼式异步电动机故障的准确性。

  10. 基于量子遗传改进支持向量机理论的变压器故障诊断%The Fault Diagnosis of Transformers with Support Vector Machine Theory Improved by Quantum Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    于虹; 孙鹏

    2011-01-01

    提出了基于量子遗传改进支持向量机理论的变压器故障诊断方法.该算法首先利用粗糙集技术时变压器知识进行属性约简,通过属性表获得变压器故障的最简决策表以作为支持向量机的输入,并利用量子遗传算法获得支持向量机的最优参数设置.实验结果表明,该诊断方法分类性能良好、可靠性高且有效可行.%A new fault diagnosis method is proposed for transformers, which is based on support vector machine theory improved by quantum genetic algorithm. Firstly. The algorithm is as follows: to do attribute reduction to the transformers knowledge with the technologies of rough set, to get the simple decision table for faults and imput the table into the support vector machine, and to achieve the optimum parameters setting of the support vector machine with the quantum genetic algorithm. The experimental results demonstrate that the proposed method works well in the fault classification and is reliable, effective and feasible.

  11. 基于随机森林的变压器故障检测方法的研究∗%Fault Diagnosis for Transformer Based on Random Forests

    Institute of Scientific and Technical Information of China (English)

    陶栋琦; 薄翠梅; 易辉

    2015-01-01

    To study the fault diagnosis of power system,safe and stable operation of the transformer is of great signif-icance. The content of the various characteristics of gases dissolved in transformer oil setting-up for the decision-making analysis is the important methods for the detection of transformer. In view of the single decision tree classifi-cation,its effect is poor,poor in anti-interference ability. The method of using random forests is put forward for fault classification,and a combined classifier model is set up by the combination of classifiers,high precision,strong sta-bility and not fitted,so that the occurrence of fault can be more timely and effectively diagnosed,the normal opera-tion of the transformer can be ensured.%研究变压器的故障检测对电力系统安全稳定运行具有重大意义,对油中溶解的各特征气体含量建立决策器进行分析是变压器故障检测的重要方法,针对单棵决策树的分类效果不良,抗干扰能力差,提出了利用随机森林的方法建立组合分类器模型进行故障分类,该组合分类器精确度高、稳定性强且不会出现过拟合现象,从而使发生的故障能得到更及时有效的诊断,进一步保障变压器的正常运行。

  12. Recognition of Active Faults and Stress Field

    Science.gov (United States)

    Azuma, T.

    2012-12-01

    Around the plate-boundary region, the directions of maximum and minimum stress related to the plate motion is one of the key for the recognition of active faults. For example, it is typical idea that there are many N-S trading reverse faults, NE-SW and NW-SE trending strike slip faults and less normal faults (only near volcanoes) in Japan, where the compressional stress with E-W direction is dominant caused by the motion of the subduction of the Pacific Plate beneath the North American Plate. After the 2011 Tohoku earthquake (Mj 9.0), however, many earthquakes with the mechanism of the normal fault type occurred in the coastal region of the northern-east Japan. On 11th April 2011, the Fukushima Hamadori Earthquake (Mj 7.0) occurred accompanying surface faults along two faults, the Idosawa fault and the Yunotake fault, that recognized as active faults by the Research Group for Active Fault of Japan (1980, 1991). It impacted on active fault study by the reason of not only the appearance of two traces of significant surface faults with maximum displacement up to 2.1 m, but also the reactivation of the normal faults under the E-W compressional stress field. When we identify the active faults, it is one of the key whether the direction of slip on the fault consists with the stress field in that area or not. And there is a technique to recognized whether the fault is active or not by using the data of the direction of stress in the field and the geometry of the fault plane. Though it is useful for the fault in the rock without overlain Quaternary deposits, we should care that the active faults may react caused by the temporal stress condition after the generation of large earthquakes.

  13. Methods of evaluating segmentation characteristics and segmentation of major faults

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kie Hwa; Chang, Tae Woo; Kyung, Jai Bok [Seoul National Univ., Seoul (Korea, Republic of)] (and others)

    2000-03-15

    Seismological, geological, and geophysical studies were made for reasonable segmentation of the Ulsan fault and the results are as follows. One- and two- dimensional electrical surveys revealed clearly the fault fracture zone enlarges systematically northward and southward from the vicinity of Mohwa-ri, indicating Mohwa-ri is at the seismic segment boundary. Field Geological survey and microscope observation of fault gouge indicates that the Quaternary faults in the area are reactivated products of the preexisting faults. Trench survey of the Chonbuk fault Galgok-ri revealed thrust faults and cumulative vertical displacement due to faulting during the late Quaternary with about 1.1-1.9 m displacement per event; the latest event occurred from 14000 to 25000 yrs. BP. The seismic survey showed the basement surface os cut by numerous reverse faults and indicated the possibility that the boundary between Kyeongsangbukdo and Kyeongsannamdo may be segment boundary.

  14. Microstructural features of fault gouges from Tianjingshan-Xiangshan fault zone and their geological implications

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Detailed observation of the microstructural features of 11 fault gouge and 3 fault breccia samples collected from Tianjingshan-Xiangshan fault zone has revealed that fault gouge can be classified into 3 types: flow banded granular gouge, foliated gouge and massive gouge. The determination of the shape preferred orientation (SPO) of survivor grains in fault gouges indicates that the foliated gouge displays a profound SPO inclined to the shear zone boundary, similar to the P-foliation; flow banded granular gouge displays a SPO parallel to the shear zone boundary, while massive fault gouge and fault breccia display a random SPO. All these fault gouges fall in different fields of shear rate ternary diagram.

  15. Imaging of subsurface faults using refraction migration with fault flooding

    Science.gov (United States)

    Metwally, Ahmed; Hanafy, Sherif; Guo, Bowen; Kosmicki, Maximillian

    2017-08-01

    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except that it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  16. Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

    KAUST Repository

    Metwally, Ahmed

    2017-05-31

    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  17. A step forward in understanding step-overs: the case of the Dead Sea Fault in northern Israel

    Science.gov (United States)

    Dembo, Neta; Granot, Roi; Hamiel, Yariv

    2017-04-01

    The rotational deformation field around step-overs between segments of strike-slip faults is poorly resolved. Vertical-axis paleomagnetic rotations can be used to characterize the deformation field, and together with mechanical modeling, can provide constraints on the characteristics of the adjacent fault segments. The northern Dead Sea Fault, a major segmented sinistral transform fault that straddles the boundary between the Arabian Plate and Sinai Subplate, offers an appropriate tectonic setting for our detailed mechanical and paleomagnetic investigation. We examine the paleomagnetic vertical-axis rotations of Neogene-Pleistocene basalt outcrops surrounding a right step-over between two prominent segments of the fault: the Jordan Gorge section and the Hula East Boundary Fault. Results from 20 new paleomagnetic sites reveal significant (>20˚) counterclockwise rotations within the step-over and small clockwise rotations in the vicinity. Sites located further (>2.5 km) away from the step-over generally experience negligible to minor rotations. Finally, we construct a mechanical model guided by the observed rotational field that allows us to characterize the structural, mechanical and kinematic behavior of the Dead Sea Fault in northern Israel.

  18. Application of Improved Wavelet Neural Network in Fault Diagnosis of Transformer%改进的小波神经网络在变压器故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    李晓静; 李杰

    2013-01-01

    为提高变压器油溶解气体分析法的故障诊断能力,以变压器油溶解气体作为研究对象,提出了加动量批处理小波神经网络算法.选取200组油溶解气体含量作为故障识别样本,通过多输入/多输出模式小波神经网络模型的构造,对训练过程和仿真结果进行对比分析.实验结果表明,改进的小波神经网络算法故障检测符合率高达95%,较传统的检测算法提升十几个百分点,从而极大的提高了故障诊断效率,实用性较好.%In order to improve the ability of fault diagnosis for analyzing the dissolved gases in transformer oil,a increased momentum batch wavelet neural network (WNN)algorithm was presented taking dissolved gases in transformer oil as the research objects.After the faults are recognized from 200 practical gas data,comparison and analysis are carried out in training process and simulation results with multiple-input/multiple-output-mode WNN model structure.Experimental results show that the improved algorithm fault detecting coincidence rate reaches as high as 95 %,up to a dozen percentage points than traditional detection algorithm,greatly improving the efficiency of fault diagnosis.The algorithm has better usability.

  19. Application of Dynamic Weighted Fuzzy Clustering Algorithm to Fault Diagnosis of Transformer%动态加权模糊聚类在变压器故障诊断中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘太洪; 赵永雷

    2016-01-01

    为提高变压器故障诊断准确率,提出了一种基于遗传算法的动态加权模糊C均值聚类算法。该算法使用把聚类中心作为染色体的浮点数的编码方式,染色体长度可变,不同的长度对应于不同的故障聚类数;并使用权值区别不同样本点对故障划分的影响程度。将该算法应用于电力变压器油中溶解气体分析(DGA)数据分析,实现了变压器的故障诊断。经过大量实例分析,并将结果与其他算法进行对比,表明该算法具有较高的诊断精度。%ABSTRACT:In order to improve the correct rate of fault diagnosis of transformer, this paper investigates a dynamic weighted fuzzy c-means clustering algorithm based on genetic algorithm. The algorithm adopts a kind of cluster-center-based floating point encoding mode, in which the variable length chromosomes express cluster prototypes and different length of chromosomes corresponding to different numbers of cluster prototypes;besides,The algorithm utilizes the weights to express the relative degree of the importance of various data in fault partitioning. The algorithm is applied to DGA data analysis, which can accomplish fault diagnosis of the transformer. Examples analysis and comparison results show that the preci-sion of fault diagnosis can be evidently improved.

  20. Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013

    Science.gov (United States)

    Castro, Raúl R.; Stock, Joann M.; Hauksson, Egill; Clayton, Robert W.

    2016-07-01

    We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike-slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39°). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_{P} = 48.1 ± 1.1 f^{0.88 ± 0.04} and Q_{S} = 135.4 ± 1.1 f^{0.58 ± 0.03} and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027-2042, 2014) for the south-central GoC. The stress drop estimates, obtained using the ω2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except

  1. Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013

    Science.gov (United States)

    Castro, Raúl R.; Stock, Joann M.; Hauksson, Egill; Clayton, Robert W.

    2017-06-01

    We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 ( M w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike-slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39°). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_{{P}} = 48.1 ± 1.1 f^{0.88 ± 0.04} and Q_{{S}} = 135.4 ± 1.1 f^{0.58 ± 0.03} and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027-2042, 2014) for the south-central GoC. The stress drop estimates, obtained using the ω2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification

  2. 基于小波神经网络和D-S证据理论的电力变压器故障诊断研究%Study on Power Transformers Fault Diagnosis Based on Wavelet Neural Network and D-S Evidence Theory

    Institute of Scientific and Technical Information of China (English)

    梁流铭; 陈伟根; 岳彦峰

    2008-01-01

    Transformer faults are quite complicated phenomena and can occur due to a variety of reasons. There have been several methods for transformer fault synthetic diagnosis, but each of them has its own limitations in real fault diagnosis applications. In order to overcome those shortcomings in the existing methods, a new transformer fault diagnosis method based on a wavelet neural network optimized by adaptive genetic algorithm (AGA) and an improved D-S evidence theory fusion technique is proposed in this paper. The proposed method combines the oil chromatogram data and the off-line electrical test data of transformers to carry out fault diagnosis. Based on the fusion mechanism of D-S evidence theory, the comprehensive reliability of evidence is constructed by considering the evidence importance, the outputs of the neural network and the expert experience. The new method increases the objectivity of the basic probability assignment (BPA) and reduces the basic probability assigned for uncertain and unimportant information. The case study results of using the proposed method show that it has a good performance of fault diagnosis for transformers.

  3. InSAR time-series constraints on inter-seismic strain accumulation and creep distribution along North Anatolian and Chaman Faults

    Science.gov (United States)

    Havazli, E.; Fattahi, H.; Amelung, F.

    2013-12-01

    In many aspects, the San Andreas and the North Anatolian fault zones show many similarities. They are similarly right-lateral, strike-slip faults, at the same time, are transforms. However, they vary in the maximum amount of lateral displacement and show different topographic features. The maximum offset is nearly 300 km along the San Andreas Fault whereas it is approximately 85-90 km along the North Anatolian Fault. In recent years, interseismic crustal velocities and strains have been determined for North Anatolian Fault Zone through repeated measurements using the Global Positioning System and satellite radar interferometry. The Chaman Fault in Pakistan and Afghanistan is the only major fault along the western India-Eurasia plate boundary zone and probably accommodates the entire relative plate motion of 30-35 mm/yr. Recent GPS and InSAR studies on the Chaman fault yield slip rates of 18 × 1 mm/yr. The inconsistency in geologic, geodetic and seismic slip rates along the Chaman Fault need investigations to better understand the geodynamic responses of the Indo-Asia collision along its western boundary. We use InSAR time-series analysis using archived and new SAR imagery to constrain strain accumulation across the North Anatolian Fault and Chaman Faults. We expect a relative accuracy of InSAR measurements better than 1 mm/yr over 100 km, made possible by recent advances in flattening residual, orbital error and atmospheric correction strategies [Fattahi & Amelung, 2013]. After validation of the technique in Southern San Andreas Fault, using GPS observations, we apply the same InSAR time-series approach to constrain strain accumulation across the North Anatolian and Chaman Faults. We will use the InSAR data to establish the first-order fault properties of the Chaman and North Anatolian Faults (creep distribution, locking depth) using analytical two-dimensional elastic strain accumulation models along different transects across the faults. Our preliminary results

  4. Precambrian crustal evolution and Cretaceous–Palaeogene faulting in West Greenland: Magnetic anomalies and metamorphic boundaries in the southern Nagssugtoqidian orogen, West Greenland

    Directory of Open Access Journals (Sweden)

    Korstgård, John A.

    2006-12-01

    Full Text Available Within the southern Nagssugtoqidian orogen in West Greenland metamorphic terrains of both Archaean and Palaeoproterozoic ages occur with metamorphic grade varying from low amphibolites facies to granulite facies. The determination of the relative ages of the different metamorphic terrains is greatly aided by the intrusion of the 2 Ga Kangâmiut dyke swarm along a NNE trend. In Archaean areas dykes cross-cut gneiss structures, and the host gneisses are in amphibolite to granulite facies. Along Itilleq strong shearing in an E–W-oriented zone caused retrogression of surrounding gneisses to low amphibolite facies. Within this Itivdleq shear zone Kangâmiut dykes follow the E–W shear fabrics giving the impression that dykes were reoriented by the shearing. However, the dykes remain largely undeformed and unmetamorphosed, indicating that the shear zone was established prior to dyke emplacement and that the orientation of the dykes here was governed by the shear fabric. Metamorphism and deformation north of Itilleq involve both dykes and host gneisses, and the metamorphic grade is amphibolite facies increasing to granulite facies at the northern boundary of the southern Nagssugtoqidian orogen. Here a zone of strong deformation, the Ikertôq thrust zone, coincides roughly with the amphibolite–granulite facies transition. Total magnetic field intensity anomalies from aeromagnetic data coincide spectacularly with metamorphic boundaries and reflect changes in content of the magnetic minerals at facies transitions. Even the nature of facies transitions is apparent. Static metamorphic boundaries are gradual whereas dynamic boundaries along deformation zones are abrupt.

  5. 2010-2014 Seismic activity images the activated fault system in the Pollino area, at the Appennines-Calabrian arc boundary region

    OpenAIRE

    De Gori, P.; Margheriti, L.; Lucente, F. P.; Govoni, A.; Moretti, M.; Pastori, M.; Marchetti, A.; R. Di Giovanbattista; Anselmi, M.; Luca, P.; Nardi, A.; N. Piana Agostinetti; LA TORRE, D.; D. Piccinini; Passarelli, L

    2014-01-01

    The main goal of this study is to increase the understanding of the physical mechanisms behind the ongoing seismic activity in the Pollino area and its influence on the seismic hazard of the Apennines-Calabrian arc boundary region. The study area, near the Pollino massif, is located at the northernmost edge of the Calabrian Arc, which is the last oceanic subduction segment along the Africa-Eurasian plate. The subduction results from the sinking of the Ionian oceanic plate beneath the Calabria...

  6. 基于多分类相关向量机的变压器故障诊断新方法%New transformer fault diagnosis method based on multi-class relevance vector machine

    Institute of Scientific and Technical Information of China (English)

    尹金良; 朱永利; 俞国勤

    2013-01-01

    The transformer fault diagnosis is naturally a multi-classification problem with few sample data and a lot of uncertainties. Among the existing transformer fault diagnosis methods, a large number of sample data and amount of computation are needed for Bayesian Network (BN), and the adjustment of the coefficient is difficult for support vector machine (SVM). So a new method of transformer fault diagnosis based on multi-class relevance vector machine (M-RVM) is proposed. The method takes ratios of feature gases as inputs and Fast Type-II ML and expectation maximization (EM) are adopted. Diagnostic outputs are probability for each fault category and fault type with the highest probability is taken as diagnosis result. Experimental results show that the diagnosis speed is sufficient for project needs and M-RVM shows higher diagnosis accuracy compared with BN and SVM.%  变压器故障诊断本质为多分类问题,具有故障样本数据少,故障不确定因素多的特点。现有变压器故障诊断方法中,贝叶斯网络(BN)需要大量样本数据且计算量大,支持向量机(SVM)存在规则化系数确定困难的局限。针对此现状,提出基于多分类相关向量机(M-RVM)的变压器故障诊断新方法。该方法以变压器溶解气体含量比值作为M-RVM模型的输入,采用快速type-II 最大似然(Fast Type-II ML)和最大期望估计(EM)的方法进行模型推断,诊断输出为各故障类别的概率,以概率最大的故障类别作为诊断结果。实例分析表明该方法诊断速度较快,能满足工程需要,同基于BN和SVM的变压器故障诊断方法相比,具有较高的诊断正确率。

  7. Transformer Fault Diagnosis Based on C-SVC and Cross-validation Algorithm%基于支持向量机和交叉验证的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    张艳; 吴玲

    2012-01-01

    为及时监测变压器潜伏性故障和准确诊断故障,提出基于优化惩罚因子C参数的支持向量机算法(C-SVC:C-support vector classification)和交叉验证算法相结合的变压器故障诊断方法.该方法利用变压器在故障时产生的氢气、甲烷、乙烷、乙烯、乙炔的体积分数数据建立训练集和测试集.在训练集中,该方法能自动优化出(寻找最佳)支持向量机的核函数的参数γ和惩罚因子C,利用优化的参数对训练集进行训练,可得到最佳的支持向量机模型,并用该模型对测试集进行分类,从而诊断出变压器的故障类型.变压器故障诊断实例分析结果证明,该方法可行,有效,且具有较高的故障诊断准确率.%A novel method for power transformer fault diagnosis based on the C-SVC (support vector classification with the optimized penalty parameter C) and cross-validation algorithm is presented, which can monitor and detect latent transformer faults timely and accurately. The training and testing sets of the C-SVC algorithm are built upon the data about the dissolved gases including hydrogen, methyl hydride, ethane, aethylenum and acetylene produced from transformer faults. Through the optimizing process of the penalty parameter and kernel function parameter y in the training set, the optimal support vector machine model can be gotten, with which the classification of data in the testing set can be conducted to determine fault features. The method has been validated by many practical examples to be feasible and efficient with high fault diagnosis accuracy.

  8. 基于双树复小波变换的轴承故障诊断研究%Research on Bearing Fault Diagnosis Based on Dual--tree Complex Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    艾树峰

    2011-01-01

    提出了一种基于双树复小波变换解调技术的轴承故障诊断新方法。该方法利用双树复小波变换具有近似平移不变性、避免频率混叠和有效降噪的优点,首先对轴承故障振动信号进行双树复小波分解和重构,将振动信号分解成实部和虚部,然后计算振动信号的双树复小波幅值包络和包络谱。齿轮箱轴承故障振动实验信号的分析表明,该方法能在强噪声环境下准确提取轴承故障产生的周期性瞬态冲击信号,能有效消除频率混叠现象和强噪声的影响,能有效识别轴承内圈和外圈故障。%A novel method of bearing fault diagnosis based on demodulation technique of DTCWT. It is demonstrated that the proposed dual-tree complex wavelet transform has better shift invariance, reduced frequency aliasing effect and de-noising ability. The bearing fault vibration signals were firstly decomposed and recostructed using dual-tree complex wavelet transform. Then the real and i maginary parts were obtained and the vibration signals were amplitude demodulated. In the end, the amplitude envelope and wavelet envelope spectrum were computed. Therefore, the characteristics of the bearing faults can be recognized according to the wavelet envelope spectrum. The experimental resuits show that fault diagnosis based on dual-tree complex wavelet transform can diagnose bearing faults effectively under strong noise conditions and reduce spectral aliasing.

  9. The Arctic Ocean in summer: A quasi-synoptic inverse estimate of boundary fluxes and water mass transformation

    OpenAIRE

    Tsubouchi, T; S. Bacon; Garabato, A.C. Naveira; Aksenov, Y.; Laxon, S. W.; Fahrbach, E.; Beszczynska-Möller, A.; Hansen, E.; Lee, Craig M.; Ingvaldsen, Randi

    2012-01-01

    The first quasi-synoptic estimates of Arctic Ocean and sea ice net fluxes of volume, heat and freshwater are calculated by application of an inverse model to data around the ocean boundary. Hydrographic measurements from four gateways to the Arctic (Bering, Davis, and Fram Straits and the Barents Sea Opening) completely enclose the ocean, and were made within the same 32-day period in summer 2005. The inverse model is formulated as a set of full-depth and density-layer-specific volume and sal...

  10. 输变电设备监测装置运行故障及可用性分析%Monitoring Device Fault and Availability Analysis of Electric Transmission and Transformation Equipment

    Institute of Scientific and Technical Information of China (English)

    王永奇

    2016-01-01

    In allusion to the current situation of lower availability ratio of electric transmission and transformation equipment online monitor-ing device at present, introduction was made to the practical application of monitoring device. This paper analyzed the fault causes of electric transmission and transformation equipment generated in the respects of communications, power supply, sensors and workstations, and presented fault handling measures, so as to improve the availability of electric transmission and transformation equipment online monitoring device.%针对目前输变电设备在线监测装置可用率较低的现状,介绍了监测装置的实际应用情况,分析了输变电设备在线监测装置在通信、供电电源、传感器及工作站等方面故障产生的原因,并提出了相应的处理措施,以提高输变电设备监测装置的可用率。

  11. 基于HPSO-WNN的牵引变压器故障诊断算法研究%Research on Traction Transformer Faults Diagnosis Algorithm Based on HPSO-WNN

    Institute of Scientific and Technical Information of China (English)

    付强; 陈特放; 朱佼佼

    2012-01-01

    为全面有效地诊断电力机车牵引变压器故障,提出一种基于混合粒子群算法的正交小波神经网络(HP SO-WNN)方法,对牵引变压器进行综合测试和诊断.将色谱数据和电气试验数据作为正交小波神经网络的输 入量,网络隐藏层采用具有正交性的小波函数db4作为基函数,利用混合粒子群算法获得正交小波神经网络的初 始值并优化网络参数.试验结果证明,本文提出的HPSO-WNN确实可有效提高牵引变压器故障诊断速度和准 确度.%In order to diagnose traction transformer faults more effectively and in an all-round way, this paper proposed the method of the orthogonal wavelet neural network based on the hybrid particle swarm optimization algorithm (HPSO-WNN) to be applied in comprehensive tests and diagnoses of electric locomotive traction transformer faults. The chromatographic data and electrical test data worked as the inputs of the orthogonal wavelet neural network, the network's hidden layer used the orthogonal dh4 function as the basis function, and the hybrid particle swarm algorithm was used to obtain the initial values of the orthogonal wavelet neural network and to optimize the network parameters. The test results show that the proposed HPSO-WNN does effectively improve the traction transformer fault diagnosis speed and accuracy.

  12. Simulation research on hydraulic transformer system fault of 300 MN die forging hydraulic press%300MN模锻液压机液压变压系统故障仿真研究

    Institute of Scientific and Technical Information of China (English)

    刘石梅; 谭建平; 陈晖

    2011-01-01

    In order to analyze the fault of hydraulic transformer which failed to work in long-stroke pressurizing because of its too long return time, a simulation model about hydraulic transformer system of 300 MN forging hydraulic press was established based on AMESim software. The influence of opening height of drain valves and pressure of liquidfilled tank on the return time of hydraulic transformer was simulated quantitatively. The condition, which would result in fault, was obtained and used to analyze the actual fault. The result shows that the fault can be eliminated through reducing the space between the cam plunger and drain valve stem by 4. 6 mm.Keywords: die forging hydraulic press; hydraulic transformer; simulationDesign and manufacture of multi-transfer hydraulic press with resistant-bias loading and synchronization mechanismAbstract: Multi-transfer hydraulic press, a kind of hydraulic equipment with the compact structure and high-efficiency,is widely used in sheet metal shaping and forming operations in the developed countries. To the problem appeared in multi-transfer hydraulic press, such as the wide table, serious bias loading and high-precision forming etc., a four-column multi-transfer hydraulic press developed for the forming of auto parts and components was designed and introduced. Through the research and analysis to the mainframe structure style and closed loop electric-hydraulic control system, the stationary motion performances as well as the integrated performances of equipment were improved and the resistant-bias loading capacity was enhanced in order to meet the high accuracy and compaction requirements.%针对300 MN模锻液压机实际生产中存在的变压器回程时间过长而无法长行程加压故障,基于AMESim软件建立了变压系统的仿真模型并进行了故障仿真,定量地得到了变压器操纵分配器排水阀开启度与充液罐压力对回程时间的影响规律.推导出变压器发生无法长行程加压故

  13. 基于双树复小波包变换的滚动轴承故障诊断%Fault diagnosis of rolling bearing based on dual-tree complex wavelet packet transform

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 孟志鹏; 陆明

    2013-01-01

    The operation states of rolling bearings which are the most common and important parts in the mechanical equipment, will affect the whole machine operation condition directly. Due to the working environment of rolling, bearing is complicated, the fault vibration signal of rolling bearing is usually non-stationary, and the strong noise interference is contained in the vibration signal at the same time. So it is important to eliminate the noise interference and extract fault feature information effectively for the rolling bearing. Dual-tree complex wavelet packet transform is a new method of signal processing. Dual-tree complex wavelet packet transform has many good characteristics, for example, approximate shift invariance, good directional selectivity、perfect reconstruction, limited data redundancy, efficient computational efficiency and so on. The high frequency part of dual-tree complex wavelet transform that is not decomposed, is further decomposed by dual-tree complex wavelet packet transform, so as to improve the whole frequency band signal frequency resolution and reduce the loss of information. In view of the above situation, a new fault diagnosis method is proposed based on dual-tree complex wavelet packet transform and threshold de-noising. Firstly, the non-stationary fault signal is decomposed into several different frequency band components through dual-tree complex wavelet packet decomposition. Secondly, Kurtosis and the cross-correlation coefficient of each component are obtained and compared. Due to the kurtosis reflecting the signal variations, if the kurtosis value is bigger, the degree of the change of signal is bigger too. The correlation coefficient can reflect the proximity between the component and the original signal at the same time, the correlation coefficient is bigger, the more similar with the original signal. Finally, the components that have a bigger value are chosen to be de-noised by a soft threshold and reconstructed by dual

  14. Present-day strain partitioning and strain transfer across the Fairweather and Denali Faults in SW Yukon - SE Alaska

    Science.gov (United States)

    Mazzotti, S.; Marechal, A.; Elliott, J.; Freymueller, J. T.; Schmidt, M.

    2012-12-01

    In SW Yukon - SE Alaska, the present-day Pacific - North America relative motion is highly oblique to the main plate boundary, resulting in strong strain partitioning tectonics that link the Aleutian subduction to the west to Queen-Charlotte transform to the south. This transition region is also the site of present-day orogeny and accretion of the allochthonous Yakutat Terrane to the Northern Cordillera. We present results from new campaign and permanent GPS stations deployed in SW Yukon, combined with STEEP data from SE Alaska, straddling the Fairweather and Denali Faults. GPS data are processed with the NRCan PPP software to derive long-term velocities and are corrected for transient effects primarily due to Glacial Isostatic Adjustment to recent ice mass loss. In the southern region (from Yakutat, AK to Whitehorse, YK), our preferred model gives slip rates of 49.9 +/- 2.6 mm/a on the Fairweather Fault and 1.1 +/- 1.0 mm/a on the Denali Fault; i.e., over 95% the Pacific - North America strike-slip motion is accommodated on the main plate-boundary fault. However, the fault-normal component is strongly partitioned, with ~25% of the Pacific - North America convergence transferred inland, into the Yukon and Northern Cordillera. This strain transfer could explain the seismicity observed in the Mackenzie Mountains 500 - 800 km from the coast. In the northern region (from Yakutat, AK to Beaver Creek, YK), the Pacific - North America convergence is strongly partitioned, with less than ~60% accommodated on the Chugach-St. Elias Fault and the residual motion distributed between the Pamplona thrust zone to the south (~15%) and internal shortening of the St. Elias Mountains to the north (~25%), where few faults and little seismicity are observed. The new GPS data also helps address the activity and slip rate of a potential "Connector Fault" that would link the Fairweather and Totschunda Faults, bypassing the Denali Fault in SW Yukon.

  15. 珠海发电厂01启备变内部故障定位分析%Fault Location Analysis of No. 1 Standby Transformer of Zhuhai Power Plant

    Institute of Scientific and Technical Information of China (English)

    孔永科

    2014-01-01

    针对启备变在受电过程中发生的故障,从故障录波图形着手,采用频谱分析的方法,判断出了故障发生的原因,准确而及时地定位了故障点,为事故抢修和及时送电争取了时间,提高了电厂厂用电系统供电的可靠性。%Aiming at the fault occurred in the charging process of the standby transformer,starting from the fault recorder graphics,and by the method of frequency spectrum analysis,this paper found the reason for the failure, timely and accurately located the fault point. This saves time for emergency repair and timely transmission,and im-proves the reliability of power system of power plant.

  16. Tectonic history of the north portion of the San Andreas fault system, California, inferred from gravity and magnetic anomalies

    Science.gov (United States)

    Griscom, A.; Jachens, R.C.

    1989-01-01

    Geologic and geophysical data for the San Andreas fault system north of San Francisco suggest that the eastern boundary of the Pacific plate migrated eastward from its presumed original position at the base of the continental slope to its present position along the San Andreas transform fault by means of a series of eastward jumps of the Mendocino triple junction. These eastward jumps total a distance of about 150 km since 29 Ma. Correlation of right-laterally displaced gravity and magnetic anomalies that now have components at San Francisco and on the shelf north of Point Arena indicates that the presently active strand of the San Andreas fault north of the San Francisco peninsula formed recently at about 5 Ma when the triple junction jumped eastward a minimum of 100 km to its present location at the north end of the San Andreas fault. -from Authors

  17. Study on Spiral Bevel Gear Fault Diagnosis based on Artificial Neural Networks and Wavelet Transform Technique%基于小波神经网络弧齿锥齿轮故障诊断及实验研究

    Institute of Scientific and Technical Information of China (English)

    扶碧波; 方宗德; 沈云波

    2011-01-01

    提出了一种离散小波变换结合神经网络的故障状态识别方法,运用信号特征提取机理对航空用弧齿锥齿轮故障诊断及状态识别进行了研究.建立了孤齿锥齿轮传动系统振动测试试验台,对正常结构和故障结构的齿轮传动进行了试验测试,通过小波阈值去除掉齿轮箱的振动数据信号系统噪声的影响;采用离散小波变换提取信号的能量特征,利用带有反馈算法的神经网络对齿轮系统的故障状态进行了分类识别.结果表明,该方法齿轮故障识别结果的有效率可达100%,为齿轮系统的故障分析提供了一种有效途径.%A fault diagnosis method of discrete wavelet transform and neural networks is proposed, by using signal feature extraction mechanism,aviation spiral bevel gear fault diagnosis and state recognition is studied. A test rig of spiral bevel gear system vibration testing is built, the testing of normal and defective gear transmission is carried out. The influence of noise on gearbox vibration data signal system is removed through the wavelet threshold. By using discrete wavelet transform, the signal energy features is extracted, gear system fault state classification recognition is carried out by using neural networks with feedback algorithm. The results show that the gear fault recognition result effective rate is to 100% . An effective way for gear system fault analysis is provided.

  18. Scaling Group Transformation for MHD Boundary Layer Slip Flow of a Nanofluid over a Convectively Heated Stretching Sheet with Heat Generation

    Directory of Open Access Journals (Sweden)

    Md. Jashim Uddin

    2012-01-01

    Full Text Available Steady viscous incompressible MHD laminar boundary layer slip flow of an electrically conducting nanofluid over a convectively heated permeable moving linearly stretching sheet has been investigated numerically. The effects of Brownian motion, thermophoresis, magnetic field, and heat generation/absorption are included in the nanofluid model. The similarity transformations for the governing equations are developed. The effects of the pertinent parameters, Lewis number, magnetic field, Brownian motion, heat generation, thermophoretic, momentum slip and Biot number on the flow field, temperature, skin friction factor, heat transfer rate, and nanoparticle, volume fraction rate are displayed in both graphical and tabular forms. Comparisons of analytical (for special cases and numerical solutions with the existing results in the literature are made and is found a close agreement, that supports the validity of the present analysis and the accuracy of our numerical computations. Results for the reduced Nusselt and Sherwood numbers are provided in tabular and graphical forms for various values of the flow controlling parameters which govern the momentum, energy, and the nanoparticle volume fraction transport in the MHD boundary layer.

  19. Convolutional-recursive network based current transformer infrared fault image diagnosis%基于卷积递归网络的电流互感器红外故障图像诊断

    Institute of Scientific and Technical Information of China (English)

    林颖; 郭志红; 陈玉峰

    2015-01-01

    Increasing unstructured data of big data in electric system puts forward a new challenge to traditional manual processing mode. As a typical kind of unstructured data, the infrared image is very important for the research of big data in electric system. In order to automatically processing massive infrared fault images, this paper presents a convolutional recursive network based current transformer infrared fault image diagnosis method. The infrared fault images are first segmented by super pixel segmentation method and then we take advantage of the hue information to extract the temperature anomaly area; secondly, a two-level joint convolution recursive neural network is adopted, the fault device position can be identified by training a large number of samples; finally, the fault information is confirmed according to the location information of fault classification. The experimental results show that, this algorithm has better robustness, higher accuracy, and can improve the efficiency of infrared diagnosis, which is also the foundation for the feature representation of unstructured data.%电力大数据中日益增多的非结构化数据为以人工诊断为主的传统处理方式提出了新的挑战。红外故障图像作为一种典型的非结构化数据,对于电力大数据的研究有着至关重要的作用。为了达到自动处理海量红外故障图像的目的,提出了一种基于卷积递归网络的电流互感器红外故障图像诊断方法。对红外故障图像首先进行超像素分割并利用其色度信息提取温度异常区域;然后采用两级联合卷积-递归神经网络,对大量样本信息进行训练学习来指导设备故障部位识别;最后依据部位信息对故障进行分类。实验结果表明,该算法鲁棒性较强,准确性较高,有效地提高了红外检测效率,为非结构化数据的特征提取分析提供了坚实的基础。

  20. Negligible sulfur isotope fractionation during partial melting: Evidence from Garrett transform fault basalts, implications for the late-veneer and the hadean matte

    Science.gov (United States)

    Labidi, J.; Cartigny, P.

    2016-10-01

    We report the quadruple sulfur isotope compositions, sulfur contents and speciation major and trace elements (including copper and chlorine abundances) of eleven basalts collected in the Garrett transform fault. We combine these data to discuss the absence of S isotopic fractionation along both partial melting and low-pressure fractional crystallization. The variations of K2O/TiO2 and La/SmN-ratios (respectively between 0.017 and 0.067, and between 0.31 and 0.59) suggest a range of depletion in Garrett lavas that includes ultra depleted samples (K2O/TiO2 8%) are ∼80 ppm, indistinguishable from MORBs. This requires their mantle sources, variably depleted in incompatible element, to host residual sulfide buffering the Cu content of all erupted melts. We calculate a minimum S content for the source of ultra-depleted Garrett lavas of 100 ± 40ppmS, i.e. roughly a factor of 2 below the MORB mantle source. After exclusion of a single sample with Cl/K ratio >0.1 that likely experienced hydrothermal sulfide assimilation, Garrett ITLs display homogeneous δ34 S, Δ33 S and Δ36 S values with averages of - 0.68 ± 0.08 ‰, + 0.010 ± 0.005 ‰ and - 0.04 ± 0.04 ‰, respectively (all 1σ, n = 10). The δ34 S values display no relationship with either K2O/TiO2 variations or extent sulfide fractionation. From these observations, we derive a 34S/32S fractionation factor between exsolved sulfides and sulfide dissolved in silicate melts of 1.0000 ± 0.0003. The S isotopic fractionation during partial melting can thus be considered as negligible, and both MORBs and ITLs record the 34S/32S ratio of their mantle source. The concept of sulfide melts segregating from the mantle, sinking and being added to the core during planetary differentiation was termed the 'Hadean Matte'. The segregation of sulfides from the mantle to the core during planetary differentiation could account for various geochemical features of the Earth's mantle. Based on S isotopic mass balance, we derive a

  1. The Fault Location for Power System Traveling Wave With Wavelet Transform%小波变换奇异性在电力系统行波故障测距中的应用

    Institute of Scientific and Technical Information of China (English)

    王先明; 陶时伟; 陶冶; 蔡德礼

    2001-01-01

    输电线路行波双端故障测距具有很高的精度,但需要高速A/D采集、大量的数据存储、复杂的行波波头辨识,对近距离故障测量存在困难。提出利用小波变换的时频分析特性,结合行波传输的特点,对行波信号利用小波变换提取故障时行波的故障信息。利用GPS作为同步时钟,测量波头到达测量端的时刻,构成输电线路的行波测量网络,通过调度通信进行故障测距,可以提高测距的可靠性和精度。%The double-end fault location for transmission lines with high precision requires data collection with high speed A/D element,data storage in large quantities and complex identification of the traveling wave crest,so it is difficult to measure a fault in a short distance.This paper shows that the information of fault in the traveling wave signal can be found by the time-frequency analysis characteristics of the wavelet transform and the characteristics of the traveling wave transmission.The time that wave crest reaches the measured-end can be measured by using GPS as a synchronized clock.A network for measuring traveling wave can be formed through dispatch and communications to improve reliability and precision of the fault location.

  2. 基于坐标变换的永磁同步电机电流传感器容错控制∗%Current Sensor Fault Detection and Isolation Technique for Permanent Magnet Synchronous Motor Based on Axes Transformation

    Institute of Scientific and Technical Information of China (English)

    马雷; 陈宇航; 张云峰

    2016-01-01

    研究了在永磁同步电机矢量控制系统之下,电流传感器的故障诊断及容错控制。针对目前双电流传感器的矢量控制系统中可能出现的软故障,提出一种基于定子坐标变换的故障诊断及容错方法,通过控制器输出的电流值与实际反馈的电流值相比较,来判断故障类型并选择相应的容错方案。仿真结果表明:该方法能准确判断出一相或两相电流传感器故障,并选择相应的实际电流计算值来完成电流闭环控制,具有较高的可行性。%A technique for fault detection and isolation to make the traditional vector control of PMSM system drive fault tolerant against one or two phase current sensor soft failure were presented. Comparison between the output current value and the feedback value, the proposed current axes transformation were expected to determine the fault type and select the appropriate fault tolerance scheme. The simulation results showed that the control system could accurately judge the one or two phase current sensor faulty and select the corresponding current calculation value to complete the current closed-loop control, with a high feasibility.

  3. Research of Water Pump Fault Diagnosis System Based on Wavelet Transform and TMS320F2812%基于小波变换和TMS320F2812的水泵故障诊断系统研究

    Institute of Scientific and Technical Information of China (English)

    卢艳宏; 冯源

    2012-01-01

    For water pumps and uther rotating machinery, the running status of water pump equipment can be more comprehensive judged through the acquisition and analysis of water pump vibration signal. So the collection of vibration signal is the key part of equipment status monitoring and fault diagnosis. The water pump fault diagnosis system is designed in the paper based on wavelet transform and DSP, and the system can realise acquisition of the water pump vibration signal. In order to improve ratio of the vibration signal to noise, and get relatively pure vibration signal, the vibration signal which is collected is eliminated noise by the wavelet diagnosis technology. We do research on water pump fault diagnosis which exemplified by the water pump unit normal operation, overheating winding, imbalance, serious lopsided, pedestal looseness and so on, and fault set parametersamax smax , Tamax , Tsmax and amin , smir , Tamin , Tsmm arc 1. 1500, 0. 1600, 46.9787, 446. 5000 and 0. 9000, 0.0700, 40.9825, 410. 6000 respectively . The experimental results show that the system can effectively find the fault, distinguish fault type and identify degreeof fault, a kind of effective method is provided for water pump unit fault diagnosis, and has the certain instruction significance for other similar mechanical fault diagnosis.%对于水泵等旋转机械来说,通过采集水泵振动信号并进行分析,能够较全面地判断出水泵设备运行状态,因此,振动信号的采集就成为设备状态监测与故障诊断的关键部分;设计了一套基于小波变换和DSP的水泵故障诊断系统,该系统可以实现对水泵振动信号的实时采集;为了提高振动信号的信噪比,得到较为纯净的振动信号,采用小波消噪的技术对采集的振动信号进行消噪处理;并且以水泵机组正常运行和发生绕组过热、轻度不平衡、严重不平衡、支座松动等故障为例进行诊断实验,并且故障集参数am(s)x·smax

  4. The May 29 2008 earthquake aftershock sequence within the South Iceland Seismic Zone: Fault locations and source parameters of aftershocks

    Science.gov (United States)

    Brandsdottir, B.; Parsons, M.; White, R. S.; Gudmundsson, O.; Drew, J.

    2010-12-01

    The mid-Atlantic plate boundary breaks up into a series of segments across Iceland. The South Iceland Seismic Zone (SISZ) is a complex transform zone where left-lateral E-W shear between the Reykjanes Peninsula Rift Zone and the Eastern Volcanic Zone is accommodated by bookshelf faulting along N-S lateral strike-slip faults. The SISZ is also a transient feature, migrating sideways in response to the southward propagation of the Eastern Volcanic Zone. Sequences of large earthquakes (M > 6) lasting from days to years and affecting most of the seismic zone have occurred repeatedly in historical time (last 1100 years), separated by intervals of relative quiescence lasting decades to more than a century. On May 29 2008, a Mw 6.1 earthquake struck the western part of the South Iceland Seismic Zone, followed within seconds by a slightly smaller event on a second fault ~5 km further west. Aftershocks, detected by a temporal array of 11 seismometers and three permanent Icelandic Meteorological Office stations were located using an automated Coalescence Microseismic Mapping technique. The epicenters delineate two major and several smaller N-S faults as well as an E-W zone of activity stretching further west into the Reykjanes Peninsula Rift Zone. Fault plane solutions show both right lateral and oblique strike slip mechanisms along the two major N-S faults. The aftershocks deepen from 3-5 km in the north to 8-9 km in the south, suggesting that the main faults dip southwards. The faulting is interpreted to be driven by the local stress due to transform motion between two parallel segments of the divergent plate boundary crossing Iceland.

  5. 相关向量机及其在变压器故障诊断中的应用%Relevance vector machine and its application in transformer fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    尹金良; 朱永利; 俞国勤

    2012-01-01

    分析并用典型数据分类算例验证相关向量机(RVM)在分类性能方面优于支持向量机(SVM),在此基础上以标准化的变压器主要特征气体含量为输入量,采用二叉树的分类方法建立基于RVM的变压器故障诊断模型.实例分析表明,同基于SVM的故障诊断方法相比,该方法可以取得与其相当甚至更优的故障诊断正确率,相关向量个数明显少于支持向量个数,诊断速度显著提高.%Analysis and typical data classification examples validate the classification performance of RVM (Relevance Vector Machine) is better than that of SVM (Support Vector Machine). A transformer fault diagnosis method based on RVM is put forward, which takes the normalized contents of transformer feature gases as inputs and adopts the binary tree classification means. Experimental results show that, compared with the fault diagnosis method based on SVM,it gets comparable or better diagnostic accuracy with less vector amount and faster diagnosis speed.

  6. 变压器励磁涌流和内部故障识别新判据%A New Criterion for Identification of Transformer Inrush Current and Internal Fault

    Institute of Scientific and Technical Information of China (English)

    李艺文

    2011-01-01

    Aiming at the identification of inrush current and internal fault, which is the key issue of transformer differential protection, and adopting the ampitudes and attenuation factors of the fundamental wave and second harmonic in the original signal with Prony algorithm, a new criterion based on Id2/Id1 and a2l a1 is established in this paper. When the inrush current occurs, Id2 /Id1 = 0.617 > 0.15 , a2 /a1 = 1.67 2. This result is obtained through analysis on the simulation data of transformer inrush current and internal fault from calculations with PSCAD / EMTDC software. The proposed criterion can significantly improve the sensitivity for identification of the inrush current and internal fault.%针对励磁涌流和内部故障识别这个变压器差动保护关键问题,利用Prony算法求取原信号中基波和二次谐波的幅值和衰减因数,建立了一种新判据:二次谐波与基波幅值之比(Id2/Id1)及衰减系数之比(a2/a1).当励磁涌流时,Id2/Id1>0.15,a2/a12.这一结果是通过分析基于PSCAD/EMTDC建立的变压器发生励磁涌流和内部故障时的仿真图得到的.所建议的识别励磁涌流和内部故障的新判据具有高的灵敏度.

  7. Intercomparison of terrain-following coordinate transformation and immersed boundary methods in large-eddy simulation of wind fields over complex terrain

    Science.gov (United States)

    Fang, Jiannong; Porté-Agel, Fernando

    2016-09-01

    Accurate modeling of complex terrain, especially steep terrain, in the simulation of wind fields remains a challenge. It is well known that the terrain-following coordinate transformation method (TFCT) generally used in atmospheric flow simulations is restricted to non-steep terrain with slope angles less than 45 degrees. Due to the advantage of keeping the basic computational grids and numerical schemes unchanged, the immersed boundary method (IBM) has been widely implemented in various numerical codes to handle arbitrary domain geometry including steep terrain. However, IBM could introduce considerable implementation errors in wall modeling through various interpolations because an immersed boundary is generally not co-located with a grid line. In this paper, we perform an intercomparison of TFCT and IBM in large-eddy simulation of a turbulent wind field over a three-dimensional (3D) hill for the purpose of evaluating the implementation errors in IBM. The slopes of the three-dimensional hill are not steep and, therefore, TFCT can be applied. Since TFCT is free from interpolation-induced implementation errors in wall modeling, its results can serve as a reference for the evaluation so that the influence of errors from wall models themselves can be excluded. For TFCT, a new algorithm for solving the pressure Poisson equation in the transformed coordinate system is proposed and first validated for a laminar flow over periodic two-dimensional hills by comparing with a benchmark solution. For the turbulent flow over the 3D hill, the wind-tunnel measurements used for validation contain both vertical and horizontal profiles of mean velocities and variances, thus allowing an in-depth comparison of the numerical models. In this case, TFCT is expected to be preferable to IBM. This is confirmed by the presented results of comparison. It is shown that the implementation errors in IBM lead to large discrepancies between the results obtained by TFCT and IBM near the surface

  8. Scaling group transformation for MHD boundary-layer flow of a nanofluid past a vertical stretching surface in the presence of suction/injection

    Energy Technology Data Exchange (ETDEWEB)

    Kandasamy, R., E-mail: future990@gmail.com [Computational Fluid Dynamics, FSSW, Universiti Tun Hussein Onn Malaysia (Malaysia); Loganathan, P.; Arasu, P. Puvi [Department of Mathematics, Anna University, Tamil Nadu (India)

    2011-06-15

    Highlights: > A nanofluid is a new class of heat transfer fluids that contain a base fluid and nanoparticles. > The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. > In nanofluid systems, thermophoresis particle deposition in the presence of magnetic field with Brownian motion has a substantial effect on the flow field. - Abstract: The problem of laminar fluid flow which results from the stretching of a vertical surface with variable stream conditions in a nanofluid has been investigated numerically. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis in the presence of magnetic field. The symmetry groups admitted by the corresponding boundary value problem are obtained by using a special form of Lie group transformations viz. scaling group of transformations. An exact solution is obtained for translation symmetry and numerical solutions for scaling symmetry. This solution depends on a Lewis number, magnetic field, Brownian motion parameter and thermophoretic parameter. The conclusion is drawn that the flow field and temperature and nanoparticle volume fraction profiles are significantly influenced by these parameters.

  9. Extending the boundaries of mechanical properties of Ti-Nb low-carbon steel via combination of ultrafast cooling and deformation during austenite-to-ferrite transformation

    Science.gov (United States)

    Deng, Xiangtao; Fu, Tianliang; Wang, Zhaodong; Liu, Guohuai; Wang, Guodong; Misra, R. D. K.

    2017-01-01

    We underscore here a novel approach to extend the boundaries of mechanical properties of Ti-Nb low-carbon steel via combination of ultrafast cooling and deformation during austenite-to-ferrite transformation. The proposed approach yields a refined microstructure and high density nano-sized precipitates, with consequent increase in strength. Steels subjected to ultra-fast cooling during austenite-to-ferrite transformation led to 145 MPa increase in yield strength, while the small deformation after ultra-fast cooling process led to increase in strength of 275 MPa. The ultra-fast cooling refined the ferrite and pearlite constituents and enabled uniform dispersion, while the deformation after ultra-fast cooling promoted precipitation and broke the lamellar pearlite to spherical cementite and long thin strips of FexC. The contribution of nano-sized precipitates to yield strength was estimated to be 247.9 MPa and 358.3 MPa for ultrafast cooling and deformation plus ultrafast cooling processes. The nano precipitates carbides were identified to be (Ti, Nb)C and had a NaCl-type crystal structure, and obeyed the Baker-Nutting orientation relationship with the ferrite matrix.

  10. Fault diagnosis

    Science.gov (United States)

    Abbott, Kathy

    1990-01-01

    The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to

  11. Improved DFIG Capability during Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    , the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility.......In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...

  12. Active fault traces along Bhuj Fault and Katrol Hill Fault, and trenching survey at Wandhay, Kachchh, Gujarat, India

    Indian Academy of Sciences (India)

    Michio Morino; Javed N Malik; Prashant Mishra; Chandrashekhar Bhuiyan; Fumio Kaneko

    2008-06-01

    Several new active fault traces were identified along Katrol Hill Fault (KHF).A new fault (named as Bhuj Fault,BF)that extends into the Bhuj Plain was also identified.These fault traces were identified based on satellite photo interpretation and field survey.Trenches were excavated to identify the paleoseismic events,pattern of faulting and the nature of deformation.New active fault traces were recognized about 1 km north of the topographic boundary between the Katrol Hill and the plain area.The fault exposure along the left bank of Khari River with 10 m wide shear zone in the Mesozoic rocks and showing displacement of the overlying Quaternary deposits is indicative of continued tectonic activity along the ancient fault.The E-W trending active fault traces along the KHF in the western part changes to NE-SW or ENE-WSW near Wandhay village. Trenching survey across a low scarp near Wandhay village reveals three major fault strands F1, F2,and F3.These fault strands displaced the older terrace deposits comprising Sand,Silt and Gravel units along with overlying younger deposits from units 1 to 5 made of gravel,sand and silt. Stratigraphic relationship indicates at least three large magnitude earthquakes along KHF during Late Holocene or recent historic past.

  13. Measurements of Sea Salt Aerosols in the Marine Boundary Layer and Free Troposphere: Vertical Transport and Chemical Transformation

    Science.gov (United States)

    Hudson, P. K.; Murphy, D. M.; Cziczo, D. J.; Thomson, D. S.

    2002-12-01

    During the Intercontinental Transport and Chemical Transformation (ITCT) mission (Monterey, CA, spring 2002) nearly 400,000 positive and negative mass spectra of single atmospheric aerosols were acquired using the PALMS (Particle Analysis by Laser Mass Spectrometry) instrument. The primary focus of the mission was to investigate the composition of air masses along the western coast of the United States. Of particular interest to the mission was to study the influence of anthropogenic emissions from Asia on aerosol composition. To accomplish these goals, the WP-3 aircraft, equipped with a suite of instruments including PALMS, covered a large spatial area flying from 0 - 8000 m altitude covering most of the western coastline from Canada to southern California including flights over the San Francisco and Los Angeles metropolitan areas. The in situ measurements of single particle aerosol mass spectra by PALMS allow for good spatial and vertical resolution of the aerosol composition. By observing the changes in aerosol composition as a function of altitude, the vertical transport of sea salt aerosols over marine and urban environments is examined. Using measurements of other chemical tracers along with the aerosol composition, the chemical processing of these aerosols during transport both vertically and inland can be discerned. These results add insight into the transport and chemical evolution of sea salt aerosol.

  14. A new method of identifying inrush and internal faults of power transformer based on H-S transform%基于双曲S变换的变压器励磁涌流和内部故障识别新方法

    Institute of Scientific and Technical Information of China (English)

    焦尚彬; 黄璜; 赵黎明; 张青

    2011-01-01

    A new method to identify inrush and internal fault of transformer based on hyperbolic S-transform (HST) is discussed. This paper uses the S transform (ST) which has excellent characteristics of time-frequency skills and time-frequency resolution and adopts the Hyperbolic window function. The signals of inrush current and fault current are transformed to phase space by using HST to extract the feature > the time-frequency contours are obtained. It is found that the time-frequency contours in case of inrush are different from that in case of internal faults. By calculating the energy after H-S transform and the ratio of energy level 1-9 and level 1 we found that ratio 6 is the threshold between inrush and fault current. The simulation result and dynamic test show that H-S transform can reflect the signal's time-frequency localization clearly, can identify inrush current, and it has strong capability in noise reduction, and is easy to separate signal from noise in ST domain.%提出了一种基于双曲S变换识别励磁涌流和变压器内部故障的新方法.利用S变换具有优秀时频呈现能力和时频分辨率的特点,采用双曲窗函数,把励磁涌流和故障电流信号变换到相空间进行特征提取,从经过变换以后得到的时频等值线图可以发现二者具有明显不同的特征.通过计算H-S变换后的能量以及1-9层能量与1层能量的比值,发现比值6是区别励磁涌流和故障电流的阈值.仿真分析结果和动模试验均表明:H-S变换可以更清楚地反映信号的时频局部化特性,能准确识别励磁涌流;并且具有较好的抗干扰能力,在变换域易于信号和噪声的分离.

  15. 基于小波变换的变压器励磁涌流和内部故障电流的识别研究%Research of Magnetizing Inrush Current and Internal Fault Current Identification Basedon Wavelet Transform in Transformer Protection

    Institute of Scientific and Technical Information of China (English)

    王俊俊; 曹龙汉; 姜昆

    2015-01-01

    在变压器差动保护中,励磁涌流的准确识别是保护可靠动作的保证,也是变压器保护的难点之一。提出一种准确可靠的基于小波变换的变压器励磁涌流和内部故障电流识别新方法。采用Matlab/Simulink建立模型进行仿真,得到了励磁涌流与内部故障电流的波形图,利用db2小波进行4尺度小波变换,将高频分量在第4尺度上的2个初始峰值比作为励磁涌流和内部故障电流识别的判据。大量实验表明,此判据能有效识别变压器差动保护中的励磁涌流和故障电流。%In differential protection of transformer, the accurate identification of magnetizing inrush current is a guarantee of reliable action, which also is difficult point in the protection of transformer. This paper proposes a new accurate and reliable method of transformer magnetizing inrush current and internal fault current based on wavelet transform. We get the oscillograms of magnetizing inrush current and internal fault current by Matlab/Simulink modeling simulation, in which we make use of the db2 4-scale wavelet transform and treat the 4th dimension of two initial peak values as the identify basis of magnetizing inrush current and internal fault current in high frequency components. Experiments show that this criterion can effectively recognize the magnetizing inrush current and internal fault current in differential protection of transformer.

  16. 气体色谱分析在变压器故障判断中的应用%The Applying of Gas Chromatography Analysis in Transformer Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    黄仰凯

    2013-01-01

      运用气体色谱分析法对一起变压器内部绕组引线短路事故进行试验分析,结合变压器抽芯检查,验证采用气体色谱分析法判断变压器内部故障性质的准确性,提出气体色谱分析在变压器故障判断中的重要性,工程施工中必须重视大型变压器投运前后变压器油的气体色谱分析试验。%The paper analyzes transformer winding short-circuit using gas chromatography analysis. It has proved the reliability of gas chromatography analysis with transformer core pulling. And offers the importance of gas chromatography analysis in transformer fault diagnosis. In engineering construction , we must attach great importance to gas chromatography analysis of transformer-oil in the beginning of runing and the end.

  17. Deep Fault Drilling Project—Alpine Fault, New Zealand

    Directory of Open Access Journals (Sweden)

    Rupert Sutherland

    2009-09-01

    Full Text Available The Alpine Fault, South Island, New Zealand, constitutes a globally significant natural laboratory for research into how active plate-bounding continental faults work and, in particular, how rocks exposed at the surface today relate to deep-seated processes of tectonic deformation, seismogenesis, and mineralization. The along-strike homogeneity of the hanging wall, rapid rate of dextral-reverse slip on an inclined fault plane, and relatively shallow depths to mechanical and chemical transitions make the Alpine Fault and the broader South Island plate boundary an important international site for multi-disciplinary research and a realistic target for an ambitious long-term program of scientific drilling investigations.

  18. Architecture of small-scale fault zones in the context of the Leinetalgraben Fault System

    Science.gov (United States)

    Reyer, Dorothea; Philipp, Sonja L.

    2010-05-01

    Understanding fault zone properties in different geological settings is important to better assess the development and propagation of faults. In addition this allows better evaluation and permeability estimates of potential fault-related geothermal reservoirs. The Leinetalgraben fault system provides an outcrop analogue for many fault zones in the subsurface of the North German Basin. The Leinetalgraben is a N-S-trending graben structure, initiated in the Jurassic, in the south of Lower Saxony and as such part of the North German Basin. The fault system was reactivated and inverted during Alpine compression in the Tertiary. This complex geological situation was further affected by halotectonics. Therefore we can find different types of fault zones, that is normal, reverse, strike-slip an oblique-slip faults, surrounding the major Leinetalgraben boundary faults. Here we present first results of structural geological field studies on the geometry and architecture of fault zones in the Leinetalgraben Fault System in outcrop-scale. We measured the orientations and displacements of 17 m-scale fault zones in limestone (Muschelkalk) outcrops, the thicknesses of their fault cores and damage zones, as well as the fracture densities and geometric parameters of the fracture systems therein. We also analysed the effects of rock heterogeneities, particularly stiffness variations between layers (mechanical layering) on the propagation of natural fractures and fault zones. The analysed fault zones predominantly show similar orientations as the major fault zones they surround. Other faults are conjugate or perpendicular to the major fault zones. The direction of predominant joint strike corresponds to the orientation of the fault zones in the majority of cases. The mechanical layering of the limestone and marlstone stratification obviously has great effects on fracture propagation. Already thin layers (mm- to cm-scale) of low stiffness - here marl - seem to suffice to change the

  19. 鹰潭变电站变压器有载分接开关故障诊断研究%Study on Fault Diagnosis of Transformer On-load Tap Changer Based on Vibration signal

    Institute of Scientific and Technical Information of China (English)

    吴昊; 徐红英

    2015-01-01

    提出了一种基于小波-高低频包络谱能量提取振动信号特征并进行有载分接开关故障诊断的新方法。首先应用小波变换对振动信号进行降噪处理,然后与希尔伯特变换结合,提取振动信号的低频和高频包络,最后对包络信号进行谱分析和能量特征提取。通过实验证明,此方法可以有效地判别分接开关的状态类型,为变压器有载分接开关的状态监测与故障诊断提供了一种新的研究。%In this paper, a new method based on wavelet-envelop spectrum energy for vibration signals characteristics and making fault diagnosis of transformer on-load tap changers is presented. Firstly, the vibration signals are de-noising by wavelet analysis method. Then the envelope of low frequency and high frequency signals are extracted by wavelet analysis combined with Hilbert transformation. Lastly, the spectral analysis and energy characteristics extracted for envelope signals are completed. Through the analyzing result of the testing signal, the conclusion can be obtained this method is can effectively determine the status of the OLTC, as a new study in the fault diagnosis of the transformer on-load tap changer.

  20. Tsunamis and splay fault dynamics

    Science.gov (United States)

    Wendt, J.; Oglesby, D.D.; Geist, E.L.

    2009-01-01

    The geometry of a fault system can have significant effects on tsunami generation, but most tsunami models to date have not investigated the dynamic processes that determine which path rupture will take in a complex fault system. To gain insight into this problem, we use the 3D finite element method to model the dynamics of a plate boundary/splay fault system. We use the resulting ground deformation as a time-dependent boundary condition for a 2D shallow-water hydrodynamic tsunami calculation. We find that if me stress distribution is homogeneous, rupture remains on the plate boundary thrust. When a barrier is introduced along the strike of the plate boundary thrust, rupture propagates to the splay faults, and produces a significantly larger tsunami man in the homogeneous case. The results have implications for the dynamics of megathrust earthquakes, and also suggest mat dynamic earthquake modeling may be a useful tool in tsunami researcn. Copyright 2009 by the American Geophysical Union.

  1. Transformer Oil Dissolved Gas Research and Fault Diagnosis%变压器油中溶解气体研究和故障判断

    Institute of Scientific and Technical Information of China (English)

    贺天宇

    2014-01-01

    The transformer system failure or abnormal, transformer oil decomposition change more obvious. With transformer oil dissolved gas as the research object, and as a basis to judge a transformer failure, in order to protect the reliability of transformer operation.%变压器系统发生故障或出现异常时,变压器油液的分解变化更为明显。以变压器油液中的溶解气体为研究对象,并以此作为变压器发生故障的判断依据,从而保障变压器运行的可靠性。

  2. New mapping and structural constraints on the Queen Charlotte-Fairweather Fault system, southeast Alaska

    Science.gov (United States)

    Levoir, M. A.; Roland, E. C.; Gulick, S. P.; Haeussler, P. J.; Christeson, G. L.; Van Avendonk, H. J.

    2013-12-01

    The dextral Queen Charlotte-Fairweather Fault lies along the western margin of Canada and southeastern Alaska, a transform plate boundary accommodating motion between the North American and Pacific Plates. The Fairweather Fault is the northern extension of the Queen Charlotte Fault and has numerous and complex splays, including the Chichagof-Baranof Fault, the Peril Strait Fault, the Chatham Strait Fault, and the Icy Point-Lituya Bay Fault. Except for a few small areas, these fault systems have not been mapped in detail. We present updated geometries and fault maps of the entirety of the strike-slip system using seismic reflection and bathymetric data, including a 2004 seismic reflection survey (EW0408), 2005 United Nations Commission on Law of the Sea multibeam bathymetry, and legacy data from the U.S. Geological Survey (USGS) and the National Geophysical Data Center. This work is highly relevant for earthquake hazard research and mitigation in southeast Alaska. Several large (> Mw 7.0) earthquakes have occurred along this margin in the last century, impacting communities of southeastern Alaska and western Canada. Two large, recent events include 1) a Mw 7.7 earthquake that took place on 28 October 2012 near the Haida Gwaii Islands offshore of western Canada, and 2) a Mw 7.5 event which occurred on 05 January 2013, 330 km to the northwest and offshore of Craig, Alaska. Interestingly, the Haida Gwaii earthquake ruptured as a thrust event and the Craig earthquake ruptured with a near-vertical dextral strike-slip mechanism. Since a change in Pacific Plate motion around 4 million years ago, the southern Queen Charlotte Fault system has been obliquely converging at a rate of 20 mm/year, with the boundary accommodating about 80 km of perpendicular motion over that time. This convergence explains the Haida Gwaii thrust earthquake, but leaves questions about the along-strike fault structure. Two opposing end-member theories suggest convergence is accommodated by either: 1

  3. MANIFESTATION OF FAULT ZONES IN GEOPHYSICAL FIELDS

    Directory of Open Access Journals (Sweden)

    A. A. Spivak

    2015-09-01

    Full Text Available Geophysical fields influenced by tectonics faults were observed, and instrumental observation results are analysed in the article. It is shown that fault zones are characterized by geophysical fields that are more variable than those in midmost segments of crustal blocks, more intense responses to weak external impacts such as lunar and solar tides and atmospheric pressure variations, and intensive relaxation. Transformation of energy between geophysical fields varying in origin takes place mainly in the fault zones.

  4. 基于故障分量的牵引变压器和应涌流识别方法%An algorith m based on the fault component to identify traction transformer sympathetic inrush

    Institute of Scientific and Technical Information of China (English)

    谭明; 罗建; 余高旺; 祝海明

    2012-01-01

    Sympathetic inrush may cause mal-operation of traction transformer differential protection, so it is necessary to study the method of identifying sympathetic inrush. The emergence mechanism of sympathetic inrush is analyzed firstly, and then it is pointed out that the long time effect of non-periodic components of sympathetic inrush causes current transformer locally saturated and produces the differential current by changing the preach variable characteristics of current transformer, which leads to the mal-operation of differential protection. There is time difference between differential current and the non-periodic fluctuation of excitation voltage fault component caused by initial inrush. Then, combined with the characteristics which are mentioned above, an algorithm of identifying the sympathetic inrush based on the time differential method of fault component is put forward. Lastly, a dynamic model test is made in the case of the traction transformer's common V/V connection model. The algorithm is easy to realize and the dynamic model test verifies its validity and practicability.%和应涌流可能引起牵引变压器差动保护误动,因此有必要对和应涌流的识别方法进行研究.首先对和应涌流的产生机理进行深入剖析,指出和应涌流中的非周期分量长时间的作用导致电流互感器(Current Transformer,CT)局部暂态饱和引起其两侧的传变特性发生变化产生差流而导致误动.然后,结合变压器的起始涌流引起励磁电压故障分量出现非周期波动与差流出现时刻之间存在一定的时间差的特点,提出基于故障分量的时差法来识别和应涌流的方法.最后以牵引变压器中常见的V/V接线方式为例,通过动模实验对所提出的算法进行仿真验证.该算法原理简单且易于实现,仿真结果表明了算法的有效性和实用性.

  5. Implications of Fault Curvature for Slip Distributions, Opening, and Damage

    Science.gov (United States)

    Ritz, E.; Pollard, D. D.; Griffith, W. A.

    2010-12-01

    In his seminal 1905 paper on the dynamics of faulting, E.M. Anderson idealized faults as planar structures. Although the theory of fault mechanics has developed from this idealization, abundant evidence from geological and geophysical investigations shows that fault surfaces exhibit geometric irregularities on many scales. Understanding the mechanical behavior of non-planar fault surfaces is a fundamental problem for scientists working on the brittle deformation of Earth’s crust and is of practical importance to disciplines such as rock mechanics, geotechnical engineering, and earthquake science. Geologic observations of exhumed meter-scale strike-slip faults in the Bear Creek drainage, Sierra Nevada, CA, provide insights into the relationship between non-planar fault geometry and frictional slip at depth. These faults have smoothly curving surface expressions which may be approximated as sinusoidal curves. We numerically investigate both the natural fault geometries and model sinusoidal faults. Earlier models for the stress and deformation near a sinusoidal fault assume boundary conditions and fault characteristics that are not observed in nature. The 2D displacement discontinuity boundary element method is combined with a complementarity algorithm to model quasi-static slip on non-planar faults, and the resulting deformation of the nearby rock. This numerical technique can provide an accurate solution for any boundary value problem regarding crack-like features in an otherwise homogeneous and isotropic elastic material. Both field and numerical investigations indicate that non-planar fault geometry perturbs the along-fault slip form the distribution predicted for planar faults. In addition, both field observations and numerical modeling show that sliding along curved faults at depth may lead to localized fault opening, affecting local permeability and fluid migration.

  6. 负荷端变压器和接地过渡阻抗对短路故障仿真的影响%Influence of load-side transformers and grounding impedance on short-circuit fault simulation

    Institute of Scientific and Technical Information of China (English)

    夏成军; 黄冬燕; 代文良; 邱桂华

    2011-01-01

    Combining with C-phase short-circuit fault case of a regional power grid and taking advantage of electrical wiring diagram and action sequence of protection device in this fault, this paper firstly models PSCAD/EMTDC to calculate the error between simulation outputs and the actual system response, and then analyzes the main error sources. To determine whether and how the simplified model will impact on the simulation results, component models on zero sequence current path and their parameters are adjusted to reduce the error and make the simulation result more realistic from two aspects of load-side transformers and grounding resistance, providing reference basis to increase the validity of short-circuit fault simulation based on PSCAD/EMTDC and to guide scientific modeling.%在结合某地区电网C相短路故障实例,根据电网电气接线图及该事故中继电保护装置的动作时序在PSCAD/EMTDC中初步建立仿真模型,计算仿真值与现场实测数据的误差,并分析主要误差来源.围绕建模过程中对模型的简化处理是否会对仿真结果造成影响以及影响的程度如何这一问题,着重从负荷端变压器和接地过渡阻抗两个角度出发,通过修正零序电流通路上的元件模型及其参数,减小了误差,使仿真结果逼近实测值,为进一步研究影响仿真准确度的因素打下基础.

  7. 油色谱分析在变压器状态监测中的应用研究%Application of Oil Chromatographic Analysis to Transformer Fault Diagnosis

    Institute of Scientific and Technical Information of China (English)

    李晨

    2012-01-01

      电力变压器发生潜在性故障时,绝缘油会分解产生烃类气体,采用油色谱法分析这些烃类气体,可诊断出电压器中存在的潜伏性故障信息,保证设备可靠运行;首先分析了油色谱分析的原理,然后设计了变压器油色谱在线监测系统,最后测试表明利用油色谱技术对变压器故障进行分析诊断的有效性和正确性。%  Hydrocarbon gas will be generated by the decomposition of the Insulating oil when there is a potential failure in pow⁃er transformers,the potential failure is diagnosed by using Oil Chromatographic Analysis to Hydrocarbon gas,firstly,this paper analyses the principle of Oil chromatographic,and it designs the on-line transformer oil chromatography monitoring system,in the end, the experiment shows the Validity and correctness of using the use of oil chromatographic techniques to Diagnosis the Transformer Fault.

  8. 3D Geometry of Active Shortening, Uplift and Subsidence West of the Alpine Fault (South Island, New Zealand)

    Science.gov (United States)

    Ghisetti, F.; Sibson, R. H.; Hamling, I. J.

    2014-12-01

    The Alpine Fault is the principal component of the transform boundary between the Australian and Pacific plates across the South Island of New Zealand, linking the opposite dipping Hikurangi and Puysegur subduction zones. In the northern South Island, the transition from the subducted W-dipping Pacific slab of the Hikurangi margin to the intra-continental transform margin is defined by earthquake foci from 350 to 100 km deep. West of the Alpine Fault the Australian crust above the slab has been incorporated into the collisional plate boundary and uplifted in a compressional belt up to 100 km wide. Retro-deformation and back-stripping of 10 regional transects utilising surface geology, seismic reflection lines and exploration wells define the progressive deformation of the Australian crust since 35 Ma along the collisional margin. The reconstructed geometry of faulted basement blocks is tied to localisation and evolution of overlying sedimentary basins, coeval with displacement on the Alpine Fault. Amounts of shortening, uplift and subsidence and fault activity are heterogeneous in space and time across the margin, and are controlled by compressional reactivation of inherited high-angle, N-S Paleogene normal faults oblique to the margin. However, significant differences also occur along the strike of the collisional margin, with major contrasts in uplift and subsidence north and south of lat. 41°.7, i.e. the region overlying the southern termination of the Hikurangi slab. These differences are highlighted by present day hydrographic anomalies in the Buller region, and by the pattern of filtered topography at > 75 km wavelength. Our data show that the 3D geometry of the Australian plate cannot be entirely attributed to inherited crustal heterogeneity of a flexured "retro-foreland" domain in the footwall of the Alpine Fault, and suggest the need of deeper dynamic interaction between the Pacific and Australian lithosphere along the subduction-collision margin.

  9. Fault diagnosis of radar filter based on wavelet transform and neural network%基于小波变换和神经网络的雷达滤波器故障诊断

    Institute of Scientific and Technical Information of China (English)

    王翔文; 李志华

    2016-01-01

    由于模拟电路的非线性、容差性及元器件参数的连续可变性等特点的存在,传统的模拟电路故障诊断手段在实际运用中已经很难得到令人满意的结果。本文将小波变换与神经网络结合,对特征提取进行优化,以雷达滤波电路为研究对象,在考虑容差性的情况下对电路进行故障诊断,体现出小波神经网络在诊断正确性及时效性上所具有的优势。%With the consideration of actual analog circuit has some characteristics, such as nonlinear-ity, tolerance and the continuous variability of parameters on component, it is difficult to achieve expected results for traditional technology of analog circuit fault diagnosis in particular engineering. In this paper, wavelet transform and neural network are combined to optimization the feature extraction. Taking into account the tolerance, we researched fault diagnosis of radar filter. The result shows that wavelet neural network method reflects its adventages from both diagnosis correctness and timeliness.

  10. Contemporary fault mechanics in southern Alaska

    Science.gov (United States)

    Kalbas, James L.; Freed, Andrew M.; Ridgway, Kenneth D.

    Thin-shell finite-element models, constrained by a limited set of geologic slip rates, provide a tool for evaluating the organization of contemporary faulting in southeastern Alaska. The primary structural features considered in our analysis are the Denali, Duke River, Totschunda, Fairweather, Queen Charlotte, and Transition faults. The combination of fault configurations and rheological properties that best explains observed geologic slip rates predicts that the Fairweather and Totschunda faults are joined by an inferred southeast-trending strike-slip fault that crosses the St. Elias Mountains. From a regional perspective, this structure, which our models suggest slips at a rate of ˜8 mm/a, transfers shear from the Queen Charlotte fault in southeastern Alaska and British Columbia northward to the Denali fault in central Alaska. This result supports previous hypotheses that the Fairweather-Totschunda connecting fault constitutes a newly established northward extension of the Queen Charlotte-Fairweather transform system and helps accommodate right-lateral motion (˜49 mm/a) of the Pacific plate and Yakutat microplate relative to stable North America. Model results also imply that the Transition fault separating the Yakutat microplate from the Pacific plate is favorably oriented to accommodate significant thrusting (23 mm/a). Rapid dip-slip displacement on the Transition fault does not, however, draw shear off of the Queen Charlotte-Fairweather transform fault system. Our new modeling results suggest that the Totschunda fault, the proposed Fairweather-Totschunda connecting fault, and the Fairweather fault may represent the youngest stage of southwestward migration of the active strike-slip deformation front in the long-term evolution of this convergent margin.

  11. Cenozoic geodynamics of the Ross Sea region, Antarctica: Crustal extension, intraplate strike-slip faulting, and tectonic inheritance

    Science.gov (United States)

    Salvini, Francesco; Brancolini, Giuliano; Busetti, Martina; Storti, Fabrizio; Mazzarini, Francesco; Coren, Franco

    1997-11-01

    An integrated study of onshore and offshore geology of the Ross Sea region (namely, Victoria Land, north of Ross Island, and the Ross Sea, Antarctica) has revealed a complex, post-Eocene tectonic framework. Regional NW-SE right-lateral, strike-slip faults are the outstanding feature of this framework and overprint an older Mesozoic extensional event, responsible for formation of N-S basins in the Ross Sea. The Cenozoic framework includes kinematic deformation and reactivation along the NW-SE faults, including formation of pull-apart basins, both positive and negative flower structures, and push-up ridges. N-S extensional faults are well developed between NW-SE faults and indicate E-W extension during the Cenozoic, produced by the NW-SE right-lateral strike-slip motion together with regional crustal extension. NNW-SSE compression, induced by the right-lateral, strike-slip kinematics, is indicated by locally inverted NE-SW faults and basins. The evolution, geometry, and location of the Rennick Graben and the Lanterman Range fit well into this model. Variations in the deformational style across the region can be linked to corresponding variations in the bulk crustal rheology, from brittle behavior in the west, to ductile deformation (at subseismic-scale resolution) near the Eastern Basin. A semibrittle region that favors N-S clustering of Cenozoic magmatic activity lies in between. In this region, Cenozoic volcanoes develop at the intersections of the NW-SE and the major N-S faults. The NW-SE faults cut almost continually from the Ross Sea to East Antarctica through lithospheric sectors with different rheology and thickness. At least two of the NW-SE faults correspond to older Paleozoic terrane boundaries in northern Victoria Land. The NW-SE faults link in the Southern Ocean with major transform faults related to the plate motions of Australia, New Zealand, and Antarctica.

  12. There Transformer Fault-oriented Security Research Technology Transfer Capacity Load%有载调容变压器故障导向安全技术研究

    Institute of Scientific and Technical Information of China (English)

    罗伟彬; 范伟波

    2014-01-01

    In view of the current load capacity of transformer operation tone lack of adequate security measures, will users of electrical equipment and electrical safety threat, and product applications, adversely affect the promotion of practical problems were the fault-oriented security technology research, specifically from security, advanced, practical point of view are discussed.%针对目前有载调容变压器运行中缺乏足够的安全保护措施,会对用户用电设备和用电安全造成威胁,并对产品的应用、推广产生不良影响的现实问题,进行了故障导向安全技术的研究,具体从安全性、先进性、实用性角度进行了探讨。

  13. 采用改进人工鱼群优化粗糙集算法的变压器故障诊断%Transformer Fault Diagnosis Using Improved Artificial Fish Swarm with Rough Set Algorithm

    Institute of Scientific and Technical Information of China (English)

    陈小青; 刘觉民; 黄英伟; 付波

    2012-01-01

    传统的人工智能方法对变压器大量的不完备故障信息不能有效地分析,或在故障数据的离散化过程中由于区间分割不当而无法正确诊断故障甚至误诊。为此,提出了一种基于改进人工鱼群优化粗糙集的变压器故障诊断方法。该方法首先将变压器溶解气体分析(DGA)的值作为条件属性,将故障类型作为决策属性,建立故障决策表,利用鱼群的聚群寻优行为对决策表中的连续属性数据进行离散化;然后采用粗糙集理论对离散化后的决策表进行约简,建立故障诊断规则决策表,大大简化了决策表属性约简的难度,使诊断变得更加简便。最后通过实例验证表明:该方法能够有效地对样本进行离散和约简,与传统方法相比,提高了故障诊断的正确率。%Facing a large number of incomplete fault data, the traditional artificial intelligence methods cannot effectively and timely analyze or accurately diagnosed because of the ill-conditioned problem caused by inefficient discretization approaches. We presented a method based on rough set theory integrated with improved artificial fish swarm algorithm {AFSA} for fault diagnosis of transformer. Firstly, the values of dissolved gas analysis {DGA) in oil were taken as conditional attributes and the type faults were taken as decision attributes. Various relations between fault and symptom were connected, and decision table was established. Then, the improved artificial fish swarm algorithm was used to discrete continuous attribute, and the rough set theory was used to reduce the decision table. Finally, the simplified decision rules were got, which greatly simplified the difficulty of diagnosis. The experimental results indicate that the method increases the diagnosis accuracy compared with the traditional algorithm.

  14. GENERAL FAULT ADMITTANCE METHOD LINETO- LINE-TO-LINE UNSYMMETRICAL FAULT

    Directory of Open Access Journals (Sweden)

    J. D. SAKALA

    2015-09-01

    Full Text Available Line-to-line-to-line unsymmetrical faults either involving or not involving ground are in the classical fault analysis approach difficult to analyse. This is because the classical solution requires use of the knowledge of connection of symmetrical component sequence networks for various common faults. In this approach, the phase fault constraints are converted into symmetrical sequence constraints and the sequence networks connected in a way that satisfies the constraints. The symmetrical component constraints for an unsymmetrical three-phase fault not involving ground do not lend themselves easy to the connection of the sequence networks. The exception is that, because the phase currents at the fault summate to zero, the zero sequence current is zero and therefore the zero sequence network is not connected. The connection of the positive and negative sequence networks is difficult to deduce when the fault is unsymmetrical. A classical solution is therefore difficult to find. In contrast, a solution by the general method of fault admittance matrix does not require prior knowledge of how the sequence networks are connected. It is therefore more versatile than the classical methods. The paper presents a procedure for solving a three-phase unsymmetrical fault, with different fault impedances, hence fault admittances in each phase. A computer program based on the general fault admittance method is developed and used to analyse an unsymmetrical three-phase fault on a simple power system with a delta-earthed-star connected transformer.

  15. Analysis of Distribution Transformer DC Resistance Fault Test and Prevention Measures%配电变压器直流电阻故障测试分析与防范措施

    Institute of Scientific and Technical Information of China (English)

    王观友

    2015-01-01

    配电变压器在电力系统中占据极其重要的地位,一旦烧坏或发生故障必然会影响工农业生产和人们的正常生活。可以通过对配电变压器直流电阻故障测试的方式,分析其变化情况,来判断配电变压器是否完好。此外,还可通过比较分析故障状况下的直流电阻值判定实际故障原因,及时排除和修复故障,恢复正常供电,提高供电可靠性。文章以某供电局的一台配变烧损后进行直流电阻测试为例,从测试数据分析,寻找故障原因并提出相应的防范措施,以供参考。%Distribution transformer plays a very important position in power system,once it burns out or fail will defi-nitely affect industrial and agricultural production and people's lives.You can use the distribution transformer DC resistance fault testing method,and analysis of changes,to determine whether the distribution transformers in good condition.In ad-dition,through comparative analysis of DC resistance value under fault conditions to found the actual cause of the failure,e-liminate and repair the failure,to improve the reliability of the power supply.In this article,taking DC resistance testing of a burned out distribution transformation in some power supply bureau as an example,from the test data analysis,find the failure reasons and propose appropriate measures for reference.

  16. An Improved Wavelet Network with Application to the Fault Diagnosis of Oil-immersed Transformer%改进小波网络在油浸式变压器故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    方健; 彭辉; 李自品; 舒乃秋

    2011-01-01

    小波网络是近年来神经网络研究中的一个新分支,是结合小波变换理论与神经网络的思想构造的一种新的神经网络模型.笔者构造的前馈小波神经网络是将小波分析与BP神经网络融合,以Gauss小波及其伸缩平移系作为隐含层小波基函数并且对小波神经网络做了一些改进.选择了300组油中溶解气体含量作为前馈小波神经网络训练及故障识别的样本,并对仿真结果进行分析.实验结果显示:文中构造的小波神经网络适合变压器故障诊断,其性能优于改良IEC法,传统BP神经网络法和基于主成分分析法的BP神经网络.该方法已经运用在实际的变压器故障诊断项目中.%This paper constructs a feed-forward wavelet network by combining the wavelet analysis with BP neural network. The wavelet network takes Gauss wavelet and its telescopic translation system as the hidden layer of the wavelet basic function, and the wavelet neural network is improved. 300 measured content data of dissolved gas in oil are selected as the samples for training the feed-forward wavelet network and faults recognition, and the simulation results are compared and analyzed. Experimental results demonstrate that the proposed improved wavelet network adapts to transformer fault diagnosis with better performance than the IEC, BPNN and the BP neural network based on principal component analysis. This method has been used in the actual transformer fault diagnosis project.

  17. Active Faulting and Quaternary Landforms Deformation Related to the Nain Fault

    Directory of Open Access Journals (Sweden)

    Abolghasem Gourabi

    2011-01-01

    Full Text Available Problem statement: Landforms developed across terrain defining boundary the Nain fault have imprints of recent tectonic activity in the west region of Central Iran. Depositional landforms such as alluvial fans bear signatures of later phases of tectonic activity in the form of faulting of alluvial fan deposits and development of fault traces and scarps within 100 km long and a NW-SE-trending zone, 1000-2000 m wide. Approach: We are addressing the neotectonic landforms based on detailed field work carried out in the Nain exposed active fault segments which brought forward some outstanding morphtectonic evidence of quaternary tectonically activities. Tectonic geomorphology applied to the Nain fault suggests recent subsurface activity along the Nain fault and an interconnecting faulting network of roughly NW-SE-trending, right-lateral, strike-slip segments and mostly NW-SE-oriented, transtensional to normal faults. Results: Evidence for recent activity is provided by faulted Pleistocene-Holocene deposits, fresh scarps in Late Quaternary deposits, 8-15 m lateral offsets locally affecting the drainage pattern of the area, ground creeping, aligning of series of spring faults, deflected streams and fault trace over recent alluvial fans. The existences of strike-slip faults system in the Nain area can be implications for seismic hazard. Conclusion: Motion along these structures suggests, in fact, that cumulative displacements include normal, transtensional and strike-slip components. Based on all evidence of active tectonics, earthquake risk and occurrence area is significant.

  18. Analysis and Treatment of Moist Insulation Fault in 110kV Oil-Immersed Power Transformer%110kV油浸式电力变压器绝缘受潮故障原因分析及处理

    Institute of Scientific and Technical Information of China (English)

    罗军川

    2012-01-01

    The reason of a moist insulation fault in 110kV oil-immersed power transformer is analyzed. The drying treatment of the transformer is discussed.%对一起110kV油浸式电力变压器绝缘受潮故障的原因进行了分析,并叙述了变压器干燥处理过程。

  19. 3D simulation of near-fault strong ground motion:comparison between surface rupture fault and buried fault

    Institute of Scientific and Technical Information of China (English)

    Liu Qifang; Yuan Yifan; Jin Xing

    2007-01-01

    In this paper,near-fault strong ground motions caused by a surface rupture fault(SRF)and a buried fault(BF) are numerically simulated and compared by using a time-space-decoupled,explicit finite element method combined with a multi-transmitting formula(MTF) of an artificial boundary.Prior to the comparison,verification of the explicit element method and the MTF is conducted.The comparison results show that the final dislocation of the SRF is larger than the BF for the same stress drop on the fault plane.The maximum final dislocation occurs on the fault upper line for the SRF;however,for the BF,the maximum final dislocation is located on the fault central part.Meanwhile,the PGA,PGV and PGD of long period ground motions(≤1 Hz)generated by the SRF are much higher than those of the BF in the near-fault region.The peak value of the velocity pulse generated by the SRF is also higher than the BF.Furthermore,it is found that in a very narrow region along the fault trace,ground motions caused by the SRF are much higher than by the BF.These results may explain why SRFs almost always cause heavy damage in near-fault regions compared to buried faults.

  20. Geometry and earthquake potential of the shoreline fault, central California

    Science.gov (United States)

    Hardebeck, Jeanne L.

    2013-01-01

    The Shoreline fault is a vertical strike‐slip fault running along the coastline near San Luis Obispo, California. Much is unknown about the Shoreline fault, including its slip rate and the details of its geometry. Here, I study the geometry of the Shoreline fault at seismogenic depth, as well as the adjacent section of the offshore Hosgri fault, using seismicity relocations and earthquake focal mechanisms. The Optimal Anisotropic Dynamic Clustering (OADC) algorithm (Ouillon et al., 2008) is used to objectively identify the simplest planar fault geometry that fits all of the earthquakes to within their location uncertainty. The OADC results show that the Shoreline fault is a single continuous structure that connects to the Hosgri fault. Discontinuities smaller than about 1 km may be undetected, but would be too small to be barriers to earthquake rupture. The Hosgri fault dips steeply to the east, while the Shoreline fault is essentially vertical, so the Hosgri fault dips towards and under the Shoreline fault as the two faults approach their intersection. The focal mechanisms generally agree with pure right‐lateral strike‐slip on the OADC planes, but suggest a non‐planar Hosgri fault or another structure underlying the northern Shoreline fault. The Shoreline fault most likely transfers strike‐slip motion between the Hosgri fault and other faults of the Pacific–North America plate boundary system to the east. A hypothetical earthquake rupturing the entire known length of the Shoreline fault would have a moment magnitude of 6.4–6.8. A hypothetical earthquake rupturing the Shoreline fault and the section of the Hosgri fault north of the Hosgri–Shoreline junction would have a moment magnitude of 7.2–7.5.

  1. Application of Laplace transform for determination of albedo type boundary conditions for neutronic calculations; Aplicacao da transformada de Laplace para determinacao de condicoes de contorno tipo albedo para calculos neutronicos

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Claudio Zen

    2008-07-01

    In this dissertation we use the Laplace transform to derive expressions for nonstandard albedo boundary conditions for one and two non-multiplying regions at the ends of one dimensional domains. In practice, the fuel regions of reactor cores are surrounded by reflector regions that reduce neutron leakage. In order to exclude the reflector regions from the calculations, we introduce a reflection coefficient or albedo. We use the present albedo boundary conditions to solve numerically slab-geometry monoenergetic and multigroup diffusion equations using the conventional finite difference method. Numerical results are generated for fixed source and eigenvalue diffusion problems in slab geometry(author)

  2. Aseismic Slip Observed on the Faults in Mexicali Valley, Baja California, Mexico.

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Suarez, F.; Nava, F.; Farfan, F.; Cossio Battani, G. D.; Guzman, M.

    2007-05-01

    The Mexicali Valley, which is part of the Salton Trough, is located within an active tectonic region, in the boundary between the Pacific and North American plates; a region featuring a wide zone of transform faults associated with San Andreas fault system, and a zone of distributed deformation in the pull-apart center of Cerro Prieto. Since 1996, geotechnical instruments have operated in the Valley, for continuous recording of deformation phenomena. To date, the network includes three crackmeters, eight tiltmeters, and seven piezometers installed in the shallow aquifer; all instruments have sampling intervals in the 1 to 20 minutes range. The mainly vertical displacement at Saltillo fault (known before as southernmost part of Imperial fault) has been measured on a continuous basis since February 1996 by a crackmeter installed in Ejido Saltillo (Glowacka 1996; Nava and Glowacka, 1999). In 1998 a tiltmeter was installed on the fault and a second crackmeter , in a horizontal direction, about 60° from the fault strike, was installed about 1 km south of ES. Another crackmeter in the vertical plane crossing Morelia fault and a 3D Witness on the Cerro Prieto fault were installed in 2004. In 2003 seven digital water level meters were installed at depths up to 500 meters in the local piezometric wells, with the purpose of recording aquifer level changes. The observed deformation rates measured on the Saltillo fault are 6 cm/yr and 2 cm/yr for the vertical and horizontal components, respectively and occurs in steps (creep events), separated by months of quiescence, and large events account for 70 percent of the vertical displacement. Aseismic creep events have amplitudes of 1-3 cm and durations of 1-3 days. Much less precise measurements from the Cerro Prieto fault show vertical deformation on the fault with velocity around 3.1 cm/yr , and the rate does not depend on the local seismicity. Horizontal rates change slightly with the presence of seismicity when very small

  3. Tectonics of the Nazca-Antarctic plate boundary

    Science.gov (United States)

    Anderson-Fontana, Sandra; Larson, Roger L.; Engeln, Joseph F.; Lundgren, Paul; Stein, Seth

    1987-01-01

    A new bathymetric chart of part of the Chile transform system is constructed, based mainly on an R/V Endeavor survey from 100 deg W to its intersection with the East Ridge of the Juan Fernandez microplate. A generally continuous lineated trend can be followed through the entire region, with the transform valley being relatively narrow and well-defined from 109 deg W to approximately 104 deg 30 min W. The fracture zone then widens to the east, with at least two probable en echelon offsets to the south at 104 deg and 102 deg W. Six new strike-slip mechanisms along the Chile Transform and one normal fault mechanism near the northern end of the Chile Rise, inverted together with other plate-motion data from the eastern portion of the boundary, produce a new best-fit Euler pole for the Nazca-Antarctic plate pair, providing tighter constraints on the relative plate motions.

  4. Tectonics of the Nazca-Antarctic plate boundary

    Science.gov (United States)

    Anderson-Fontana, Sandra; Larson, Roger L.; Engeln, Joseph F.; Lundgren, Paul; Stein, Seth

    1987-01-01

    A new bathymetric chart of part of the Chile transform system is constructed, based mainly on an R/V Endeavor survey from 100 deg W to its intersection with the East Ridge of the Juan Fernandez microplate. A generally continuous lineated trend can be followed through the entire region, with the transform valley being relatively narrow and well-defined from 109 deg W to approximately 104 deg 30 min W. The fracture zone then widens to the east, with at least two probable en echelon offsets to the south at 104 deg and 102 deg W. Six new strike-slip mechanisms along the Chile Transform and one normal fault mechanism near the northern end of the Chile Rise, inverted together with other plate-motion data from the eastern portion of the boundary, produce a new best-fit Euler pole for the Nazca-Antarctic plate pair, providing tighter constraints on the relative plate motions.

  5. Facies composition and scaling relationships of extensional faults in carbonates

    Science.gov (United States)

    Bastesen, Eivind; Braathen, Alvar

    2010-05-01

    :1000. In general the complete dataset shows a positive correlation between thickness (T) of fault cores and the displacement (D) on faults. For increasing displacement relationships, the D/T relationship is not constant. The D/T relationship is generally higher for small faults than for larger faults, which implies that comparisons between small and large fault with respect to this parameter should be handled with care. Fault envelope composition, as reflected by the relative proportions of different fault facies in the core, varies with displacement. In small scale faults (0-1 m displacement), secondary calcite layers and fault gouge dominate, whereas shale dominated fault rocks (shale smear) and carbonate dominated fault rocks (breccias) constitute minor components. Shale dominated fault rocks are restricted to shale-rich protoliths, and fault breccias to break-down of lenses formed near fault jogs. In medium scale faults (1-10m), fault rocks form the dominating facies, whereas the amount of secondary calcite layers decreases due to transformation into breccias. Further, in shale rich carbonates the fault cores consist of composite facies associations. In major faults (10-300 m displacement) fault rock layers and lenses dominate the fault cores. A common observation in large scale faults is a distinct layering of different fault rocks, shale smearing of major shale layers and massive secondary calcite layers along slip surfaces. Fault core heterogeneity in carbonates is ascribed to the distribution of fault facies, such as fault rocks, secondary calcite layers and shale smear. In a broader sense, facies distribution and thickness are controlled by displacement, protolith and tectonic environment. The heterogeneous properties and the varied distribution observed in this study may be valuable in forecasting fault seal characteristics of carbonate reservoirs.

  6. Improved wavelet analysis for induction motors mixed-fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hanlei; ZHOU Jiemin; LI Gang

    2007-01-01

    Eccentricity is one of the frequent faults of induction motors,and it may cause rub between the rotor and the stator.Early detection of significant rub from pure eccentricity can prolong the lifespan of induction motors.This paper is devoted to such mixed-fault diagnosis:eccentricity plus rub fault.The continuous wavelet transform(CWT)is employed to analyze vibration signals obtained from the motor body.An improved continuous wavelet trartsform was proposed to alleviate the frequency aliasing.Experimental results show that the proposed method can effectively distinguish two types of faults,single-fault of eccentricity and mixed-fault of eccentricity plus rub.

  7. An Aspect-Oriented Approach to Assessing Fault Tolerance

    Science.gov (United States)

    2014-10-01

    misconfiguration, and so forth. The Hadoop File System [8] includes a fault injection framework built using AspectJ similar to that which we describe in...this paper. The main differences between our framework and Hadoop fault injectors is that the Hadoop fault injector only supports probabilistic...Transformation and Net-Centric Systems Conference, Orlando, Florida, April 2009. [8] “ Hadoop fault injection, http://hadoop.apache.org/hdfs/docs/r0.21.0

  8. Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments

    Science.gov (United States)

    Stankiewicz, J.; Munoz, G.; Ritter, O.; Bedrosian, P.A.; Ryberg, T.; Weckmann, U.; Weber, M.

    2011-01-01

    In the framework of the DEad SEa Rift Transect (DESERT) project a 150 km magnetotelluric profile consisting of 154 sites was carried out across the Dead Sea Transform. The resistivity model presented shows conductive structures in the western section of the study area terminating abruptly at the Arava Fault. For a more detailed analysis we performed a joint interpretation of the resistivity model with a P wave velocity model from a partially coincident seismic experiment. The technique used is a statistical correlation of resistivity and velocity values in parameter space. Regions of high probability of a coexisting pair of values for the two parameters are mapped back into the spatial domain, illustrating the geographical location of lithological classes. In this study, four regions of enhanced probability have been identified, and are remapped as four lithological classes. This technique confirms the Arava Fault marks the boundary of a highly conductive lithological class down to a depth of ???3 km. That the fault acts as an impermeable barrier to fluid flow is unusual for large fault zone, which often exhibit a fault zone characterized by high conductivity and low seismic velocity. At greater depths it is possible to resolve the Precambrian basement into two classes characterized by vastly different resistivity values but similar seismic velocities. The boundary between these classes is approximately coincident with the Al Quweira Fault, with higher resistivities observed east of the fault. This is interpreted as evidence for the original deformation along the DST originally taking place at the Al Quweira Fault, before being shifted to the Arava Fault. Copyright 2011 by the American Geophysical Union.

  9. Structural evolution of the La Trocha fault zone: Oblique collision and strike-slip basins in the Cuban Orogen

    Science.gov (United States)

    Cruz-Orosa, Israel; Sã Bat, Francesc; Ramos, Emilio; Rivero, LluíS.; VáZquez-Taset, Yaniel M.

    2012-10-01

    The La Trocha fault zone acted as a major left-lateral transfer zone and is bounded by the La Trocha (LTF), Zaza-Tuinicú (ZTF), Cristales (CTF) and Taguasco (TGF) faults. These faults were consistent with the clockwise rotation of convergence and shortening in central Cuba. From the Paleocene to the Early Eocene (65-48 Ma), a SSW-NNE shortening produced transtension in the LTF and transpression in the ZTF. Subsequently, during the Middle Eocene (48-37 Ma), shortening shifted to a SW-NE direction, resulting in the normal component of the LTF and transpression in the ZTF and CTF. Since the Late Eocene (37 Ma), central Cuba has been welded to the North American Plate. The post-welding deformation gave rise to transtension of the LTF and TGF. This deformation is consistent with a WSW-ENE shortening and reflects activity in the transform boundary of the Cayman Trough. Both the normal and thrust displacements of these previous faults are corroborated by structural data whereas left-lateral displacement is deduced from the concordance between oblique collision and structural features. Plate-kinematics and the structural evolution of the La Trocha fault zone indicate that the related Central Basin is a strike-slip polygenetic basin and that the formation of this system (i.e., fault zone - strike-slip basin) was a consequence of the Paleogene oblique collision between the Caribbean Volcanic Arc and the Bahamas Borderland (North American plate).

  10. Lost in Iceland? Fracture Zone Complications Along the Mid-Atlantic Plate Boundary

    Science.gov (United States)

    Brandsdóttir, B.; Einarsson, P.; Detrick, R. S.; Mayer, L.; Calder, B.; Driscoll, N.; Richter, B.

    2003-12-01

    The mid-Atlantic plate boundary breaks up into a series of segments across Iceland. Two transform zones, the South Iceland Seismic Zone (SISZ) and the Tjörnes Fracture Zone (TFZ) separate the on land rift zones from the Reykjanes Ridge (RR), and the Kolbeinsey Ridge (KR), offshore N-Iceland. Both are markedly different from fracture zones elsewhere along the plate boundary. The 80 km E-W and 10--15 km N-S SISZ is made up of more than 20 N-S aligned, right-lateral, strike-slip faults whereas the TFZ consists of a broad zone of deformation, roughly 150 km E-W and 75 km N-S. The over-all left-lateral transform motion within the SISZ is accommodated by bookshelf faulting whereas the right-lateral transform motion within the TFZ is incorporated within two WNW-trending seismic zones, spaced ˜40 km apart, the Grímsey Seismic Zone (GSZ) and the Húsavík-Flatey fault (HFF). Recently collected EM300 and RESON8101 multibeam bathymetric data along with CHIRP subbottom data has unveiled some tectonic details within the TFZ. The GSZ runs along the offshore extension of the Northern Volcanic Rift Zone (NVRZ) and is made up of four left-stepping, en-echelon, NS-striking rift segments akin to those on land. Large GSZ earthquakes seem to be associated with lateral strike-slip faulting along ESE-striking fault planes. Fissure swarms transecting the offshore volcanic systems have also been subjected to right-lateral transformation along the spreading direction. As the Reykjanes Peninsula, the on land extension of the RR, the GSZ bears the characteristics of an oblique rift zone. The plate boundary segments connecting to the RR and KR are thus symmetrical with respect to the plate separation vector (105° ) and orientation of individual volcanic systems. The HFF has an overall strike of N65° W and can be traced continuously along its 75--80 km length, between the Theistareykir volcanic system within the NVRZ, across the central TFZ-graben, the Skjálfandi bay, and into the largest

  11. 基于灰色理论的电力变压器故障预测%Predication of Power Transformer Faults Based on Gray Theory

    Institute of Scientific and Technical Information of China (English)

    郝宁波; 廖海斌

    2011-01-01

    文章提出了一种基于综合灰色模型的电力变压器油中溶解气体浓度预测的方法,进而预测电力变压器的故障.首先对非等间隔时间序列进行等间隔处理,然后对序列进行级比检验,对于级比检验不合格的序列进行弱化处理,使用GM(1,1)得到预测序列,检验预测序列精度,对精度未满足要求的序列使用残差 GM(1,1)进行残差修正,通过预测某超高压公司电力变压器的油中溶解气体的历史数据,证明了该预测模型具有较强的实用性.%This paper presents a method based on a synthesis gray model to predict the power transformer oil dissolved gas concentrations, then predict the failure of power transformer. First, do equal-space processing to the non-equal-space time series, then carries on level compare examination to the sequence, carries on attenuated processing regarding to the unqualified sequence, after qualified we use GM(l, 1) to obtain the forecast sequence, then exam the forecast sequence's precision, to the sequence that not satisfied the request to the precision, we use residual GM(1,1) to revise residual. Through the forecast of a ultrahigh voltage company's power transformer's oil dissolved gas's historical data, we find this forecast model has strong usability.

  12. Machine Fault Signature Analysis

    Directory of Open Access Journals (Sweden)

    Pratesh Jayaswal

    2008-01-01

    Full Text Available The objective of this paper is to present recent developments in the field of machine fault signature analysis with particular regard to vibration analysis. The different types of faults that can be identified from the vibration signature analysis are, for example, gear fault, rolling contact bearing fault, journal bearing fault, flexible coupling faults, and electrical machine fault. It is not the intention of the authors to attempt to provide a detailed coverage of all the faults while detailed consideration is given to the subject of the rolling element bearing fault signature analysis.

  13. 纵横交叉算法与模糊聚类相结合的变压器故障诊断%Fault diagnosis method of transformer based on crisscross optimization algorithm and fuzzy clustering

    Institute of Scientific and Technical Information of China (English)

    孟安波; 卢海明; 郭壮志

    2016-01-01

    Optimized the FCM clustering by the proposed CSO ( CSO-FCM) is introduced to diagnose the fault of transformer in order to conquer the shortages of FCM clustering.The combination of dissolved gas analysis and FCM clustering is effective on improving the accuracy rate of power transformer fault diagnosis, but the result of FCM cluste-ring is unstable and easy getting stuck in a local optimum.The CSO algorithm includes horizon cross as well as verti-cal cross, whose combining can enhance the global convergent ability while the introduction of competitive mechanism drives the potential solutions approximate the global optima in an accelerating fashion without sacrificing the conver-gence speed.This novel method effectively compensates the demerits of single intelligent algorithm, which not only has the ability to dispose the unstable information of fuzzy theory, also has an advantage of global convergence of CSO. Simulation and case analysis indicate that, compared with the traditional FCM clustering, the CSO-FCM clustering can obtain high performance clustering center and effectively raise the accuracy and diagnosis speed of power transformer fault diagnosis.%针对FCM(模糊C-均值聚类)在变压器故障诊断中的不足,提出采用纵横交叉算法优化FCM ( CSO-FCM)聚类来进行故障诊断。溶解气体分析与FCM相结合,能有效提高变压器故障诊断的准确率,但FCM存在聚类结果不稳定和容易陷入局部最优等问题。而纵横交叉算法是一种基于种群的随机搜索算法,在算法中首次提出了维局部最优概念和纵横交叉双搜索思想。实验证明,相比其它主流群智能优化算法,CSO算法在解决维数灾问题和收敛精度问题方面取得了较大突破,能有效克服局部最优的问题。新诊断模型有效弥补了单一诊断法的不足,拥有全局收敛性强和处理模糊信息的能力。实例分析表明,该方法与传统FCM相比,能获得

  14. 大型走滑断裂对青藏高原地体构架的改造%The transformation of the terrain structures of the Tibet Plateau through large-scale strike-slip faults

    Institute of Scientific and Technical Information of China (English)

    许志琴; 李海兵; 唐哲民; 戚学祥; 李化启; 蔡志慧

    2011-01-01

    show an early ductile strike-slip shearing in the deep crust, followed by the transformation of ductile to ductile/brittle to brittle deformations during uplift process. However, in northern Tibet, it is shown as the reactivation of old strike-slip shear zones or suture zones such as the Altyn Tagh, Karakax shear zones and the East Kunlun suture zone, as well as the occurrence of the new brittle fault ( e. G. The Haiyuan fault). In this paper, we will explain the characteristics of large-scale strike-slip faults formed during different geological periods and their roles on terrain amalgamation and collision orogeny within the Tibetan plateau, including " strike-slip" type folded orogeny, " transpression" type orogeny, "compression" type basin and range system, as well as relative displacement and lateral extrusion of terrains.

  15. Analytical solutions of three-dimensional groundwater flow to a well in a leaky sloping fault-zone aquifer

    Science.gov (United States)

    Zhao, Yuqing; Zhang, You-Kuan; Liang, Xiuyu

    2016-08-01

    A semi-analytical solution was presented for groundwater flow due to pumping in a leaky sloping fault-zone aquifer surrounded by permeable matrices. The flow in the aquifer was descried by a three-dimensional flow equation, and the flow in the upper and lower matrix blocks are described by a one-dimensional flow equation. A first-order free-water surface equation at the outcrop of the fault-zone aquifer was used to describe the water table condition. The Laplace domain solution was derived using Laplace transform and finite Fourier transform techniques and the semi-analytical solutions in the real time domain were evaluated using the numerical inverse Laplace transform method. The solution was in excellent agreement with Theis solution combined with superposition principle as well as the solution of Huang et al. (2014). It was found that the drawdown increases as the sloping angle of the aquifer increases in early time and the impact of the angle is insignificant after pumping for a long time. The free-water surface boundary as additional source recharges the fault aquifer and significantly affect the drawdown at later time. The surrounding permeable matrices have a strong influence on drawdown but this influence can be neglected when the ratio of the specific storage and the ratio of the hydraulic conductivity of the matrices to those of the fault aquifer are less than 0.001.

  16. The Energetics of Gravity Driven Faulting

    Science.gov (United States)

    Barrows, L.

    2007-12-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In displacement-bounded faulting, locked-in elastic strain energy is transformed into seismic waves plus work done in the fault zone. Elastic rebound is an example of displacement-bounded faulting. In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into seismic waves plus work done in the fault zone and half goes into an increase in locked-in elastic strain. In displacement-bounded faulting the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault. Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the topography and internal stress-causing density variations is equally split between the seismic waves plus work done in the fault zone and the increase in locked-in elastic strain. The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on the fault. They must exist if gravity participates in the energetics of the faulting process. From the perspective of gravitational tectonics, the gravity collapse mechanism is direct and simple. The related mechanics are a little more

  17. Influence of fault asymmetric dislocation on the gravity changes

    Directory of Open Access Journals (Sweden)

    Duan Hurong

    2014-08-01

    Full Text Available A fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth’s crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, energy release associated with rapid movement on active faults is the cause of most earthquakes. The relationship between unevenness dislocation and gravity changes was studied on the theoretical thought of differential fault. Simulated observation values were adopted to deduce the gravity changes with the model of asymmetric fault and the model of Okada, respectively. The characteristic of unevennes fault momentum distribution is from two end points to middle by 0 according to a certain continuous functional increase. However, the fault momentum distribution in the fault length range is a constant when the Okada model is adopted. Numerical simulation experiments for the activities of the strike-slip fault, dip-slip fault and extension fault were carried out, respectively, to find that both the gravity contours and the gravity variation values are consistent when either of the two models is adopted. The apparent difference lies in that the values at the end points are 17. 97% for the strike-slip fault, 25. 58% for the dip-slip fault, and 24. 73% for the extension fault.

  18. Online fault location on crossbonded AC cables in underground transmission systems

    DEFF Research Database (Denmark)

    F. Jensen, Christian; Bak, Claus Leth; Gudmundsdottir, Unnur Stella

    2014-01-01

    system are identified. The fault locator system uses the Wavelet Transform both to create reliable triggers in the units and to estimate the fault location based on time domain signals obtained in the substations by two fault locator units. Field measurements of faults artificially created on a section...

  19. Guaranteed Cost Fault-Tolerant Control for Networked Control Systems with Sensor Faults

    Directory of Open Access Journals (Sweden)

    Qixin Zhu

    2015-01-01

    Full Text Available For the large scale and complicated structure of networked control systems, time-varying sensor faults could inevitably occur when the system works in a poor environment. Guaranteed cost fault-tolerant controller for the new networked control systems with time-varying sensor faults is designed in this paper. Based on time delay of the network transmission environment, the networked control systems with sensor faults are modeled as a discrete-time system with uncertain parameters. And the model of networked control systems is related to the boundary values of the sensor faults. Moreover, using Lyapunov stability theory and linear matrix inequalities (LMI approach, the guaranteed cost fault-tolerant controller is verified to render such networked control systems asymptotically stable. Finally, simulations are included to demonstrate the theoretical results.

  20. Extraction of weak PcP phases using the slant-stacklet transform - II: constraints on lateral variations of structure near the core-mantle boundary

    Science.gov (United States)

    Ventosa, Sergi; Romanowicz, Barbara

    2015-11-01

    Resolving the topography of the core-mantle boundary (CMB) and the structure and composition of the D″ region is key to improving our understanding of the interaction between the Earth's mantle and core. Observations of traveltimes and amplitudes of short-period teleseismic body waves sensitive to lowermost mantle provide essential constraints on the properties of this region. Major challenges are low signal-to-noise ratio of the target phases and interference with other mantle phases. In a previous paper (Part I), we introduced the slant-stacklet transform to enhance the signal of the core-reflected (PcP) phase and to isolate it from stronger signals in the coda of the P wave. Then we minimized a linear misfit between P and PcP waveforms to improve the quality of PcP-P traveltime difference measurements as compared to standard cross-correlation methods. This method significantly increases the quantity and the quality of PcP-P traveltime observations available for the modelling of structure near the CMB. Here we illustrate our approach in a series of regional studies of the CMB and D″ using PcP-P observations with unprecedented resolution from high-quality dense arrays located in North America and Japan for events with magnitude Mw>5.4 and distances up to 80°. In this process, we carefully analyse various sources of errors and show that mantle heterogeneity is the most significant. We find and correct bias due to mantle heterogeneities that is as large as 1 s in traveltime, comparable to the largest lateral PcP-P traveltime variations observed. We illustrate the importance of accurate mantle corrections and the need for higher resolution mantle models for future studies. After optimal mantle corrections, the main signal left is relatively long wavelength in the regions sampled, except at the border of the Pacific large-low shear velocity province (LLSVP). We detect the northwest border of the Pacific LLSVP in the western Pacific from array observations in

  1. Sandbox Modeling of the Fault-increment Pattern in Extensional Basins

    Institute of Scientific and Technical Information of China (English)

    Geng Changbo; Tong Hengmao; He Yudan; Wei Chunguang

    2007-01-01

    Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins.Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins.In the process of extensional deformation,the increase in the number and length of faults was episodic,and every 'episode' experienced three periods,strain-accumulation period,quick fault-increment period and strain-adjustment period.The more complex the shape of the boundary fault,the higher the strain increment each 'episode' experienced.Different extensional modes resulted in different fault-increment patterns.The horizontal detachment extensional mode has the 'linear' style of fault-increment pattern,while the extensional mode controlled by a listric fault has the 'stepwise' style of fault-increment pattern,and the extensional mode controlled by a ramp-flat boundary fault has the 'stepwise-linear' style of fault-increment pattern.These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.

  2. Fault system polarity: A matter of chance?

    Science.gov (United States)

    Schöpfer, Martin; Childs, Conrad; Manzocchi, Tom; Walsh, John; Nicol, Andy; Grasemann, Bernhard

    2015-04-01

    Many normal fault systems and, on a smaller scale, fracture boudinage exhibit asymmetry so that one fault dip direction dominates. The fraction of throw (or heave) accommodated by faults with the same dip direction in relation to the total fault system throw (or heave) is a quantitative measure of fault system asymmetry and termed 'polarity'. It is a common belief that the formation of domino and shear band boudinage with a monoclinic symmetry requires a component of layer parallel shearing, whereas torn boudins reflect coaxial flow. Moreover, domains of parallel faults are frequently used to infer the presence of a common décollement. Here we show, using Distinct Element Method (DEM) models in which rock is represented by an assemblage of bonded circular particles, that asymmetric fault systems can emerge under symmetric boundary conditions. The pre-requisite for the development of domains of parallel faults is however that the medium surrounding the brittle layer has a very low strength. We demonstrate that, if the 'competence' contrast between the brittle layer and the surrounding material ('jacket', or 'matrix') is high, the fault dip directions and hence fault system polarity can be explained using a random process. The results imply that domains of parallel faults are, for the conditions and properties used in our models, in fact a matter of chance. Our models suggest that domino and shear band boudinage can be an unreliable shear-sense indicator. Moreover, the presence of a décollement should not be inferred on the basis of a domain of parallel faults only.

  3. Investigation of a marine magnetic polarity reversal boundary in cross section at the northern boundary of the Kane Megamullion, Mid-Atlantic Ridge, 23°40'N

    Science.gov (United States)

    Xu, Min; Tivey, M. A.

    2016-05-01

    Near-bottom magnetic field measurements made by the submersible Nautile during the 1992 Kanaut Expedition define the cross-sectional geometry of magnetic polarity reversal boundaries and the vertical variation of crustal magnetization in lower oceanic crust exposed along the Kane Transform Fault (TF) at the northern boundary of the Kane Megamullion (KMM). The KMM exposes lower crust and upper mantle rocks on a low-angle normal fault that was active between 3.3 Ma and 2.1 Ma. The geometry of the polarity boundaries is estimated from an inversion of the submarine magnetic data for crustal magnetization. In general, the polarity boundaries dip away from the ridge axis along the Kane TF scarp, with a west dipping angle of ~45° in the shallow (isotherms and isochrons. We also test the effects of the rotation of this isotherm structure and/or footwall rotation and find that the magnetic polarity boundary geometry is not sensitive to these directional changes.

  4. Active faulting on the Wallula fault zone within the Olympic-Wallowa lineament, Washington State, USA

    Science.gov (United States)

    Sherrod, Brian; Blakely, Richard J.; Lasher, John P.; Lamb, Andrew P.; Mahan, Shannon; Foit, Franklin F.; Barnett, Elizabeth

    2016-01-01

    The Wallula fault zone is an integral feature of the Olympic-Wallowa lineament, an ∼500-km-long topographic lineament oblique to the Cascadia plate boundary, extending from Vancouver Island, British Columbia, to Walla Walla, Washington. The structure and past earthquake activity of the Wallula fault zone are important because of nearby infrastructure, and also because the fault zone defines part of the Olympic-Wallowa lineament in south-central Washington and suggests that the Olympic-Wallowa lineament may have a structural origin. We used aeromagnetic and ground magnetic data to locate the trace of the Wallula fault zone in the subsurface and map a quarry exposure of the Wallula fault zone near Finley, Washington, to investigate past earthquakes along the fault. We mapped three main packages of rocks and unconsolidated sediments in an ∼10-m-high quarry exposure. Our mapping suggests at least three late Pleistocene earthquakes with surface rupture, and an episode of liquefaction in the Holocene along the Wallula fault zone. Faint striae on the master fault surface are subhorizontal and suggest reverse dextral oblique motion for these earthquakes, consistent with dextral offset on the Wallula fault zone inferred from offset aeromagnetic anomalies associated with ca. 8.5 Ma basalt dikes. Magnetic surveys show that the Wallula fault actually lies 350 m to the southwest of the trace shown on published maps, passes directly through deformed late Pleistocene or younger deposits exposed at Finley quarry, and extends uninterrupted over 120 km.

  5. Identification of Lembang fault, West-Java Indonesia by using controlled source audio-magnetotelluric (CSAMT)

    Science.gov (United States)

    Sanny, Teuku A.

    2017-07-01

    The objective of this study is to determine boundary and how to know surrounding area between Lembang Fault and Cimandiri fault. For the detailed study we used three methodologies: (1). Surface deformation modeling by using Boundary Element method and (2) Controlled Source Audiomagneto Telluric (CSAMT). Based on the study by using surface deformation by using Boundary Element Methods (BEM), the direction Lembang fault has a dominant displacement in east direction. The eastward displacement at the nothern fault block is smaller than the eastward displacement at the southern fault block which indicates that each fault block move in left direction relative to each other. From this study we know that Lembang fault in this area has left lateral strike slip component. The western part of the Lembang fault move in west direction different from the eastern part that moves in east direction. Stress distribution map of Lembang fault shows difference between the eastern and western segments of Lembang fault. Displacement distribution map along x-direction and y-direction of Lembang fault shows a linement oriented in northeast-southwest direction right on Tangkuban Perahu Mountain. Displacement pattern of Cimandiri fault indicates that the Cimandiri fault is devided into two segment. Eastern segment has left lateral strike slip component while the western segment has right lateral strike slip component. Based on the displacement distribution map along y-direction, a linement oriented in northwest-southeast direction is observed at the western segment of the Cimandiri fault. The displacement along x-direction and y-direction between the Lembang and Cimandiri fault is nearly equal to zero indicating that the Lembang fault and Cimandiri Fault are not connected to each others. Based on refraction seismic tomography that we know the characteristic of Cimandiri fault as normal fault. Based on CSAMT method th e lembang fault is normal fault that different of dip which formed as

  6. 抽水蓄能机组背靠背启动中跳闸技术改造方案%Transformation on the Fault Trip during Back-to-back Starting of Pumped-storage Power Station

    Institute of Scientific and Technical Information of China (English)

    常永亮; 张兵海; 王勇; 何忠华

    2011-01-01

    针对抽水蓄能机组在背靠背拖动过程中若发生电气或机械故障跳闸,当跳开拖动机组和被拖动机组的灭磁开关的时间差过大时,会在启动回路中产生很大的短路电流,引起继电保护误动作,严重时会损毁启动回路的电气设备,提出一种抽水蓄能机组背靠背跳闸技术改造方案,通过在机组保护系统中添加“跳相邻机组单元”接点,与“跳本机组”接点同时动作,达到同时跳开拖动和被拖动机组灭磁开关的目的.技术改造后的试验证明了方案的正确性和有效性.%When the trip is occurred during the back-to-back starting of pumped-storage units as electrical or mechanical faults and there is a larger time difference between the field breaking switches, the large short -circuit current will be generated in the starting circuits and leads to the malfunction of relay protection, even to damage the electrical equipments of starting circuit in a severe condition. A trip transformation was presented for the back-to-back starting of pumped-storage units, in which, the contact of "Breaking adjacent unit" was added in protection system and will be simultaneously operated with the contact of "Breaking local unit" to meet the requirements on breaking the units on the same time. The tests show that the transformation program is effective.

  7. An Evidential Reasoning Approach to Transformer Fault Diagnosis%基于证据推理的电力变压器故障诊断策略

    Institute of Scientific and Technical Information of China (English)

    董明; 严璋; 杨莉; M.D.Judd

    2006-01-01

    Methods used to assess the insulation status of power transformers before they deteriorate to a critical state include dissolved gas analysis (DGA), partial discharge (PD)detection and transfer function techniques, etc. All of these approaches require experience in order to correctly interpret the observations. Artificial Intelligence (AI) is increasingly used to improve interpretation of the individual data sets. However, a satisfactory diagnosis may not be obtained if only one technique is used. For example, the exact location of PD cannot be predicted if only DGA is performed. However, using diverse methods may result in different diagnosis solutions, a problem that is addressed through the introduction of a fuzzy information infusion model. An inference scheme is proposed that yields consistent conclusions and manages the inherent uncertainty in the various methods. With the aid of information fusion, a framework is established that allows different diagnostic tools to be combined in a systematic way. The application of information fusion technique for insulation diagnostics of transformer is effective by means of examples.%在变压器绝缘劣化之前,可以进行油中溶解气体分析、局部放电检测、传递函数测量等试验方法对其状态进行评估.所有这些试验现象需要很多实际经验才能正确解释.因此人工智能技术逐渐被应用于提高单一试验数据的分析中.但是,仅使用一种方法,可能难以得到满意的诊断结果,如油中溶解气体分析是不能准确对局部放电进行定位.然而,应用不同的方法可能产生各异的诊断结果,因此文中引入模糊信息融合系统来解决此问题,提出了产生一致性结论和处理不同方法中不确定性的证据推理策略.并在信息融合的帮助下,建立了有机组合多种诊断方法系统框架.通过实例证明,基于信息融合的变压器绝缘故障诊断方法是有效的.

  8. Transformational Leadership and Knowledge Team Performance:The Mediating Roles of Team Boundary Management%变革型领导与知识型团队绩效:边界管理的中介作用

    Institute of Scientific and Technical Information of China (English)

    石冠峰; 杨高峰

    2015-01-01

    From the perspective of inward-facing and outward-facing boundary management, the study examines the effect of team leader′s transformational leadership on team performance by focusing on the mediating role of team bounda-ry management based on the data collected from 121 knowledge teams in the high-tech enterprise. The results indicate that transformational leadership is positively related to task performance and collaborative satisfaction, as well as inward-facing and outward-facing team boundary have positive influence on task performance and collaborative satisfaction, in-ward-facing and outward-facing team boundary partially mediate the association of transformational leadership with task performance and collaborative satisfaction. In order to boost team performance, leaders should not only cultivate transfor-mational leadership style for themselves, but also encourage employees to carry out team boundary management activities.%基于内向、外向边界管理视角,本文以高新技术企业的121个知识型团队为对象,探讨变革型领导对团队绩效的影响机理,并分析了边界管理在两者间所起的中介作用。结果表明变革型领导正向影响任务绩效和合作满意度,内向、外向边界管理均正向影响任务绩效和合作满意度,内向、外向边界管理在变革型领导与任务绩效和合作满意度之间起部分中介作用。因此,管理者既要塑造变革型领导风格,又要鼓励员工开展边界管理活动,以提升团队绩效。

  9. Fault current limiters using superconductors

    Science.gov (United States)

    Norris, W. T.; Power, A.

    Fault current limiters on power systems are to reduce damage by heating and electromechanical forces, to alleviate duty on switchgear used to clear the fault, and to mitigate disturbance to unfaulted parts of the system. A basic scheme involves a super-resistor which is a superconductor being driven to high resistance when fault current flows either when current is high during a cycle of a.c. or, if the temperature of the superconductive material rises, for the full cycle. Current may be commuted from superconductor to an impedance in parallel, thus reducing the energy dispersed at low temperature and saving refrigeration. In a super-shorted transformer the ambient temperature primary carries the power system current; the superconductive secondary goes to a resistive condition when excessive currents flow in the primary. A super-transformer has the advantage of not needing current leads from high temperature to low temperature; it behaves as a parallel super-resistor and inductor. The supertransductor with a superconductive d.c. bias winding is large and has small effect on the rate of fall of current at current zero; it does little to alleviate duty on switchgear but does reduce heating and electromechanical forces. It is fully active after a fault has been cleared. Other schemes depend on rapid recooling of the superconductor to achieve this.

  10. Application of fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.

    2007-11-30

    This report presents the results of a study commissioned by the Department for Business, Enterprise and Industry (BERR; formerly the Department of Trade and Industry) into the application of fault current limiters in the UK. The study reviewed the current state of fault current limiter (FCL) technology and regulatory position in relation to all types of current limiters. It identified significant research and development work with respect to medium voltage FCLs and a move to high voltage. Appropriate FCL technologies being developed include: solid state breakers; superconducting FCLs (including superconducting transformers); magnetic FCLs; and active network controllers. Commercialisation of these products depends on successful field tests and experience, plus material development in the case of high temperature superconducting FCL technologies. The report describes FCL techniques, the current state of FCL technologies, practical applications and future outlook for FCL technologies, distribution fault level analysis and an outline methodology for assessing the materiality of the fault level problem. A roadmap is presented that provides an 'action agenda' to advance the fault level issues associated with low carbon networks.

  11. Anatomy of the Dead Sea transform: Does it reflect continuous changes in plate motion?

    Science.gov (United States)

    ten Brink, U.S.; Rybakov, M.; Al-Zoubi, A. S.; Hassouneh, M.; Frieslander, U.; Batayneh, A.T.; Goldschmidt, V.; Daoud, M.N.; Rotstein, Y.; Hall, J.K.

    1999-01-01

    A new gravity map of the southern half of the Dead Sea transform offers the first regional view of the anatomy of this plate boundary. Interpreted together with auxiliary seismic and well data, the map reveals a string of subsurface basins of widely varying size, shape, and depth along the plate boundary and relatively short (25-55 km) and discontinuous fault segments. We argue that this structure is a result of continuous small changes in relative plate motion. However, several segments must have ruptured simultaneously to produce the inferred maximum magnitude of historical earthquakes.

  12. Fault Line Selection Method Considering Grounding Fault Angle for Distribution Network

    Institute of Scientific and Technical Information of China (English)

    Li Si-bo; Zhao Yu-lin; Li Ji-chang; Sui Tao

    2015-01-01

    In the distribution network system with its neutral point grounding via arc suppression coil, when single-phase grounding fault occurred near zero-crossing point of the phase voltage, the inaccuracy of the line selection always existed in existing methods. According to the characteristics that transient current was different between the fault feeder and other faultless feeders, wavelet transformation was performed on data of the transient current within a power frequency cycle after the fault occurred. Based on different fault angles, wavelet energy in corresponding frequency band was chosen to compare. The result was that wavelet energy in fault feeder was the largest of all, and it was larger than sum of those in other faultless feeders, when the bus broke down, the disparity between each wavelet energy was not significant. Fault line could be selected out by the criterion above. The results of MATLAB/simulink simulation experiment indicated that this method had anti-interference capacity and was feasible.

  13. FAULT IDENTIFICATION IN HETEROGENEOUS NETWORKS USING TIME SERIES ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    孙钦东; 张德运; 孙朝晖

    2004-01-01

    Fault management is crucial to provide quality of service grantees for the future networks, and fault identification is an essential part of it. A novel fault identification algorithm is proposed in this paper, which focuses on the anomaly detection of network traffic. Since the fault identification has been achieved using statistical information in management information base, the algorithm is compatible with the existing simple network management protocol framework. The network traffic time series is verified to be non-stationary. By fitting the adaptive autoregressive model, the series is transformed into a multidimensional vector. The training samples and identifiers are acquired from the network simulation. A k-nearest neighbor classifier identifies the system faults after being trained. The experiment results are consistent with the given fault scenarios, which prove the accuracy of the algorithm. The identification errors are discussed to illustrate that the novel fault identification algorithm is adaptive in the fault scenarios with network traffic change.

  14. East-west faults due to planetary contraction

    CERN Document Server

    Beuthe, Mikael

    2010-01-01

    Contraction, expansion and despinning have been common in the past evolution of Solar System bodies. These processes deform the lithosphere until it breaks along faults. The type and orientation of faults are usually determined under the assumption of a constant lithospheric thickness, but lithospheric thinning can occur at the equator or at the poles due either to latitudinal variation in solar insolation or to localized tidal dissipation. Using thin elastic shells with variable thickness, I show that the equatorial thinning of the lithosphere transforms the homogeneous and isotropic fault pattern caused by contraction/expansion into a pattern of faults striking east-west, preferably formed in the equatorial region. By contrast, lithospheric thickness variations only weakly affect the despinning faulting pattern consisting of equatorial strike-slip faults and polar normal faults. If contraction is added to despinning, the despinning pattern first shifts to thrust faults striking north-south and then to thrus...

  15. Fault Location Based on Synchronized Measurements: A Comprehensive Survey

    Directory of Open Access Journals (Sweden)

    A. H. Al-Mohammed

    2014-01-01

    Full Text Available This paper presents a comprehensive survey on transmission and distribution fault location algorithms that utilize synchronized measurements. Algorithms based on two-end synchronized measurements and fault location algorithms on three-terminal and multiterminal lines are reviewed. Series capacitors equipped with metal oxide varistors (MOVs, when set on a transmission line, create certain problems for line fault locators and, therefore, fault location on series-compensated lines is discussed. The paper reports the work carried out on adaptive fault location algorithms aiming at achieving better fault location accuracy. Work associated with fault location on power system networks, although limited, is also summarized. Additionally, the nonstandard high-frequency-related fault location techniques based on wavelet transform are discussed. Finally, the paper highlights the area for future research.

  16. Characterization of slow slip rate faults in humid areas: Cimandiri fault zone, Indonesia

    Science.gov (United States)

    Marliyani, G. I.; Arrowsmith, J. R.; Whipple, K. X.

    2016-12-01

    In areas where regional tectonic strain is accommodated by broad zones of short and low slip rate faults, geomorphic and paleoseismic characterization of faults is difficult because of poor surface expression and long earthquake recurrence intervals. In humid areas, faults can be buried by thick sediments or soils; their geomorphic expression subdued and sometimes undetectable until the next earthquake. In Java, active faults are diffused, and their characterization is challenging. Among them is the ENE striking Cimandiri fault zone. Cumulative displacement produces prominent ENE oriented ranges with the southeast side moving relatively upward and to the northeast. The fault zone is expressed in the bedrock by numerous NE, west, and NW trending thrust- and strike-slip faults and folds. However, it is unclear which of these structures are active. We performed a morphometric analysis of the fault zone using 30 m resolution Shuttle Radar Topography Mission digital elevation model. We constructed longitudinal profiles of 601 bedrock rivers along the upthrown ranges along the fault zone, calculated the normalized channel steepness index, identified knickpoints and use their distribution to infer relative magnitudes of rock uplift and locate boundaries that may indicate active fault traces. We compare the rock uplift distribution to surface displacement predicted by elastic dislocation model to determine the plausible fault kinematics. The active Cimandiri fault zone consists of six segments with predominant sense of reverse motion. Our analysis reveals considerable geometric complexity, strongly suggesting segmentation of the fault, and thus smaller maximum earthquakes, consistent with the limited historical record of upper plate earthquakes in Java.

  17. APPLICATION OF FUZZY SET THEORY IN FAULT TREE ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based on the fuzzy set theory and the expand principle, using fuzzy number as the boundary condition of fault tree analysis, a new method of analyzing fuzzy fault probability of the top event is developed. Fuzzy importance analysis of the basic event is proposed as well. A practical example is given. This method is a new way to solve the obscure problems of fault tree analysis and has great value in engineering practice.

  18. Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah

    Science.gov (United States)

    Davatzes, N.C.; Eichhubl, P.; Aydin, A.

    2005-01-01

    Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying mechanical controls for their occurrence along the Moab normal fault in southeastern Utah through the use of structural mapping and numerical elastic boundary element modeling. We found that deformation bands occur everywhere along the fault, but with increased density in contractional relays. Joints and sheared joints only occur at intersections and extensional relays. In all locations , joints consistently overprint deformation bands. Localization of joints and sheared joints in extensional relays suggests that their distribution is controlled by local variations in stress state that are due to mechanical interaction between the fault segments. This interpretation is consistent with elastic boundary element models that predict a local reduction in mean stress and least compressive principal stress at intersections and extensional relays. The transition from deformation band to joint formation along these sections of the fault system likely resulted from the combined effects of changes in remote tectonic loading, burial depth, fluid pressure, and rock properties. In the case of the Moab fault, we conclude that the structural heterogeneity in the fault zone is systematically related to the geometric evolution of the fault, the local state of stress associated with fault slip , and the remote loading history. Because the type and distribution of structures affect fault permeability and strength, our results predict systematic variations in these parameters with fault evolution. ?? 2004 Geological Society of America.

  19. Saturating time-delay transformer for overcurrent protection

    Science.gov (United States)

    Praeg, Walter F.

    1977-01-01

    Electrical loads connected to d-c supplies are protected from damage by overcurrent in the case of a load fault by connecting in series with the load a saturating transformer that detects a load fault and limits the fault current to a safe level for a period long enough to correct the fault or else disconnect the power supply.

  20. Saturating time-delay transformer for overcurrent protection. [Patent application

    Science.gov (United States)

    Praeg, W.F.

    1975-12-18

    Electrical loads connected to dc supplies are protected from damage by overcurrent in the case of a load fault by connecting in series with the load a saturating transformer that detects a load fault and limits the fault current to a safe level for a period long enough to correct the fault or else disconnect the power supply.

  1. Earthquakes in the Orozco transform zone: seismicity, source mechanisms, and tectonics

    Science.gov (United States)

    Trehu, Anne M.; Solomon, Sean C.

    1983-01-01

    As part of the Rivera Ocean Seismic Experiment, a network of ocean bottom seismometers and hydrophones was deployed in order to determine the seismic characteristics of the Orozco transform fault in the central eastern Pacific. We present hypocentral locations and source mechanisms for 70 earthquakes recorded by this network. All epicenters are within the transform region of the Orozco Fracture Zone and clearly delineate the active plate boundary. About half of the epicenters define a narrow line of activity parallel to the spreading direction and situated along a deep topographic trough that forms the northern boundary of the transform zone (region 1). Most focal depths for these events are very shallow, within 4 km of the seafloor; several well-determined focal depths, however, are as great as 7 km. No shallowing of seismic activity is observed as the rise-transform intersection is approached; to the contrary, the deepest events are within 10 km of the intersection. First motion polarities for most of the earthquakes in region 1 are compatible with right-lateral strike slip faulting along a nearly vertical plane, striking parallel to the spreading direction. Another zone of activity is observed in the central part of the transform (region 2). The apparent horizontal and vertical distribution of activity in this region is more scattered than in the first, and the first motion radiation patterns of these events do not appear to be compatible with any known fault mechanism. Pronounced lateral variations in crustal velocity structure are indicated for the transform region from refraction data and measurements of wave propagation directions. The effect of this lateral heterogeneity on hypocenters and fault plane solutions is evaluated by tracing rays through a three-dimensional velocity grid. While findings for events in region 1 are not significantly affected, in region 2, epicentral mislocations of up to 10 km and azimuthal deflections of up to 45° may result from

  2. Calculation of turbulent boundary layers with heat transfer and pressure gradient utilizing a compressibility transformation. Part 2: Constant property turbulent boundary layer flow with simultaneous mass transfer and pressure gradient

    Science.gov (United States)

    Boccio, J.; Economos, C.

    1972-01-01

    An analysis of the incompressible turbulent boundary layer, developing under the combined effects of mass transfer and pressure gradient, is presented in this paper. A strip-integral method is employed whereby two of the three governing equations are obtained by integrating the combined momentum and continuity equation to 50 percent and 100 percent, respectively, of the boundary-layer height. The latter equation is the usual momentum-integral equation; the former equation requires specification of shear. Accordingly, Clauser's equilibrium eddy-viscosity law is assumed valid at this point. The third and final equation is obtained by specifying that Stevenson's velocity profiles apply throughout the domain of interest, from which a skin-friction law can be derived. Comparisons of the numerical results with the experiments of McQuaid, which include combined effects of variable pressure gradient and mass transfer, show good agreement.

  3. Locating Very-Low-Frequency Earthquakes in the San Andreas Fault.

    Science.gov (United States)

    Peña-Castro, A. F.; Harrington, R. M.; Cochran, E. S.

    2016-12-01

    The portion of tectonic fault where rheological properties transtition from brittle to ductile hosts a variety of seismic signals suggesting a range of slip velocities. In subduction zones, the two dominantly observed seismic signals include very-low frequency earthquakes ( VLFEs), and low-frequency earthquakes (LFEs) or tectonic tremor. Tremor and LFE are also commonly observed in transform faults, however, VLFEs have been reported dominantly in subduction zone environments. Here we show some of the first known observations of VLFEs occurring on a plate boundary transform fault, the San Andreas Fault (SAF) between the Cholame-Parkfield segment in California. We detect VLFEs using both permanent and temporary stations in 2010-2011 within approximately 70 km of Cholame, California. We search continous waveforms filtered from 0.02-0.05 Hz, and remove time windows containing teleseismic events and local earthquakes, as identified in the global Centroid Moment Tensor (CMT) and the Northern California Seismic Network (NCSN) catalog. We estimate the VLFE locations by converting the signal into envelopes, and cross-correlating them for phase-picking, similar to procedures used for locating tectonic tremor. We first perform epicentral location using a grid search method and estimate a hypocenter location using Hypoinverse and a shear-wave velocity model when the epicenter is located close to the SAF trace. We account for the velocity contrast across the fault using separate 1D velocity models for stations on each side. Estimated hypocentral VLFE depths are similar to tremor catalog depths ( 15-30 km). Only a few VLFEs produced robust hypocentral locations, presumably due to the difficulty in picking accurate phase arrivals with such a low-frequency signal. However, for events for which no location could be obtained, the moveout of phase arrivals across the stations were similar in character, suggesting that other observed VLFEs occurred in close proximity.

  4. Evidence for 830 years of seismic quiescence from palaeoseismology, archaeoseismology and historical seismicity along the Dead Sea fault in Syria

    Science.gov (United States)

    Meghraoui, Mustapha; Gomez, Francisco; Sbeinati, Reda; Van der Woerd, Jerome; Mouty, Michel; Darkal, Abdul Nasser; Radwan, Youssef; Layyous, Ihsan; Al Najjar, Haithem; Darawcheh, Ryad; Hijazi, Fouad; Al-Ghazzi, Riad; Barazangi, Muawia

    2003-05-01

    The long historical record of earthquakes, the physical effects on ancient building structures and the palaeoseismology provide a unique opportunity for an interdisciplinary tectonic analysis along a major plate boundary and a realistic evaluation of the seismic hazard assessment in the Middle East. We demonstrate with micro-topographic surveys and trenching that the Dead Sea fault (DSF) offsets left-laterally by 13.6±0.2 m a repeatedly fractured ancient Roman aqueduct (older than AD 70 and younger than AD 30). Carbon-14 dating of faulted young alluvial deposits documents the occurrence of three large earthquakes in the past 2000 years between AD 100 and 750, between AD 700 and 1030 and between AD 990 and 1210. Our study provides the timing of late Holocene earthquakes and constrains the 6.9±0.1 mm/yr slip rate of the Dead Sea transform fault in northwestern Syria along the Missyaf segment. The antepenultimate and most recent faulting events may be correlated with the AD 115 and AD 1170 large earthquakes for which we estimate Mw=7.3-7.5. The ˜830 yr of seismic quiescence along the Missyaf fault segment implies that a large earthquake is overdue and may result in a major catastrophe to the population centres of Syria and Lebanon.

  5. NON -IDEAL IRIS BOUNDARY LOCALIZATION ALGORITHM BASED ON COMBINATION OF HOUGH TRANSFORM AND NONLINEAR ENHANCEMENT%Hough 变换与非线性增强结合的非理想虹膜边界定位算法

    Institute of Scientific and Technical Information of China (English)

    万洪林; 于海涛; 杨济民

    2014-01-01

    边界定位是非理想虹膜识别的关键问题之一。非理想虹膜由于经常存在纹理过强、睫毛和眼睑遮挡、虹膜巩膜对比度较差、瞳孔位置偏移等问题,这使其边界尤其是外边界定位容易出现偏差。针对上述问题,笔者提出了一种基于非线性图像增强的非理想虹膜边界定位方法。在内边界定位中,该方法首先使用混合高斯模型得到瞳孔粗略位置,然后使用弦长均衡策略搜索虹膜内边界及其中心;在外边界定位中,首先对虹膜图像进行非线性灰度变换,再利用边缘检测和改进的 Hough 变换定位虹膜外边界。实验结果表明:本算法与经典方法相比可大大提高非理想虹膜分割的准确率。%Iris boundary localization is one of the key issues of an iris recognition system.For non -ideal iris images,frequently -occurred strong texture,eyelashes or eyelids occlusion,low contrast between iris and sclera, and pupil deviation,etc,will lead inaccuracy localization of iris boundaries,particularly the outer one.We investigate this issue and propose the boundaries localization for non -ideal iris images based on the nonlinear image enhancement.In the process of inner localization,we firstly employ EM algorithm to segment pupil approximately,then use the string -equilibrium technique to search iris center and the inner boundary.In outer boundary localization,we transform nonlinearly the iris intensity,and adopt edge detector and improved Hough transform to find outer boundary.The experimental results depict that our algorithm improves the non -ideal iris localization accuracy compared to the classical algorithms.

  6. InSAR observations of strain accumulation and fault creep along the Chaman Fault system, Pakistan and Afghanistan

    Science.gov (United States)

    Fattahi, Heresh; Amelung, Falk

    2016-08-01

    We use 2004-2011 Envisat synthetic aperture radar imagery and InSAR time series methods to estimate the contemporary rates of strain accumulation in the Chaman Fault system in Pakistan and Afghanistan. At 29 N we find long-term slip rates of 16 ± 2.3 mm/yr for the Ghazaband Fault and of 8 ± 3.1 mm/yr for the Chaman Fault. This makes the Ghazaband Fault one of the most hazardous faults of the plate boundary zone. We further identify a 340 km long segment displaying aseismic surface creep along the Chaman Fault, with maximum surface creep rate of 8.1 ± 2 mm/yr. The observation that the Chaman Fault accommodates only 30% of the relative plate motion between India and Eurasia implies that the remainder is accommodated south and east of the Katawaz block microplate.

  7. Offshore observations of aftershocks following the January 5th 2013 Mw 7.5 Queen Charlotte-Fairweather fault earthquake, southeast Alaska

    Science.gov (United States)

    Roland, E. C.; Gulick, S. P.; Levoir, M. A.; Haeussler, P. J.

    2013-12-01

    We present initial results from a rapid-response ocean bottom seismometer (OBS) deployment that recorded aftershock activity on the Queen Charlotte-Fairweather (QC-F) fault following the Mw 7.5 earthquake on January 5th 2013 near Craig, Alaska. This earthquake was the second of two Mw > 7 events on this fault system in a 3 month time period; the Craig earthquake followed a Mw 7.8 thrust event that occurred in October 2012, west of Haida Gwaii, British Columbia. Although the QC-F is a major plate boundary fault, little is known about the regional fault structure, interseismic coupling, and rheological controls on the depth distribution of seismic slip along the continent-ocean transform. The majority of the QC-F fault system extends offshore western British Columbia and southeast Alaska, making it difficult to characterize earthquakes and fault deformation with land-based seismic and geodetic instruments. This experiment is the first ever offshore seismometer deployment to record earthquake activity along this northern segment of the QC-F system, and was set in motion with help from the US Coast Guard, who provided a vessel and crew to deploy and recover the OBS array on short notice. The seismic array utilized 6 GeoPro short period OBS from the University of Texas Institute for Geophysics, which recorded approximately 3 weeks of aftershock activity in April-May of 2013. Combining high-quality local OBS recordings with land-based seismic observations from Alaska Earthquake Information Center (AEIC) stations to the east, we present more precise aftershock locations and depths that help to better characterize fault zone architecture along the northern section of the QC-F. Although moment tensor solutions indicate that the January 5th mainshock sustained slip consistent with Pacific-North America plate motions, aftershock focal mechanisms indicate some interaction with neighboring faults, such as the Chatham Straight fault. This new OBS dataset will also help to

  8. Kumano Seismogenic Zone Imaging and Splay Fault Property

    Science.gov (United States)

    Kuramoto, S.; Okano, T.; Hashimoto, T.; Tanaka, H.; Taira, A.

    2003-12-01

    by upper one and covered by slope sediments that are not deformed. This phenomenon is confirmed by surface observations by submersibles and deep-towed camera surveys. Recent MCS survey of the JAMSTEC revealed extremely clear image of plate boundary faults between the subducting Philippine Sea plate and the Eurasian plate in the Kumano area. One of the prominent features of plate boundary at near proposed up-dip limit of seismogenic zone is the highly reflective (positive polarity) splay faults. The new data will be presented and discussed the property.

  9. Large seismic faults in the Hellenic arc

    Directory of Open Access Journals (Sweden)

    B. S. Papazachos

    1996-06-01

    Full Text Available Using information concerning reliable fault plane solutions, spatial distribution of strong earthquakes (Ms³ 6.0 as well as sea bottom and coastal topography, properties of the seismic faults (orientation, dimension, type of faulting were determined in seven shallow (h < 40 km seismogenic regions along the convex part of thc Hellenic arc (Hellenic trench and in four seismogenic regions of intermediate depth earthquakes (h = 40-100 km along the concave part of this arc. Except for the northwesternmost part of the Hellenic trench, where the strike-slip Cephalonia transform fault dominates, all other faults along this trench are low angle thrust faults. III thc western part of the trench (Zante-west Crete faults strike NW-SE and dip NE, while in its eastern part (east Crete-Rhodos faults strike WNW-ESE and dip NNE. Such system of faulting can be attributed to an overthrust of the Aegean lithosphere on the eastern Mediterranean lithosphere. The longest of these faults (L = 300 km is that which produced the largest known shallow earthquake in the Mediterranean area (21 July 365, Ms = 8.3 which is located near the southwestern coast of Crete. The second longest such fault (L = l 70 km is that which produced a large earthquake (December 1303, Ms = 8.0 in the easternmost part of the trench (east of Rhodos island. Both earthquakes were associated with gigantic tsunamis which caused extensive damage in the coast of many Eastern Mediterranean countries. Seismic faults of the intermediate depth earthquakes in the shallow part of the Benioff zone (h = 40- 100 km are of strike-slip type, with a thrust component. The orientations of these faults vary along the concave part of the arc in accordance with a subduction of remnants of all old lithospheric slab from the convex side (Mediterranean to the concave side (Aegean of thc Hellenic arc. The longest of these faults (L = 220 km is that which produced the largest known intermediate depth earthquake in the

  10. The Carboneras Fault Zone (SE Spain): Constraints on Fault Zone Properties and Geometry from Controlled-Source-Generated Guided Seismic Waves

    Science.gov (United States)

    Rietbrock, A.; Haberland, C. A.; Faulkner, D. R.; Nippress, S.; Rutter, E. H.; Kelly, C. M.; Teixido, T.

    2014-12-01

    We combine geophysical data, field-geological mapping and lab measurements to study the Carboneras fault zone (CFZ) in SE Spain. The CFZ is part of the Trans-Alborán Shear Zone which constitutes part of the diffuse plate boundary between Africa and Iberia. The CFZ is inferred to behave as a stretching transform fault with˜40 km left-lateral offset. It was active principally between 12 - 6 Ma BP, and has been exhumed from ca. 1 - 2 km depth. The relatively recent movement history and the semi-arid terrain lead to excellent exposure.The phyllosilicate-rich fault gougeis excellently preserved. In 2010 we conducted a controlled source seismic experiment at the CFZ in which explosive sources in boreholes (two groups of 3 explosions) were placed in two strands of the fault zone. The signals were observed with dense linear seismic arrays crossing the CFZ at 3.5km and 8.3km distance, respectively. The recordings show clear high-energy P-phases at receivers and from sources located at or near the fault zone. We interpret these phases as P-waves trapped in the low-velocity layer (waveguide) formed by the damage zone of the fault(s). With waveform modeling (using an analytical solution assuming a straight waveguide embedded in two quarter spaces and a line source at depth) we derive basic models well-explaining the observations. Lab-measurements of the different rocks constrain the possible models. Additionally, we employed extensive three-dimensional finite-difference (3D-FD) modeling with more realistic (curved and anastomosing) waveguide geometries. It seems that the studied segments of the CFZ form effective waveguides for seismic waves with connectivity over several kilometers. The derived seismic models together with lab measurements of the seismic velocities indicate that the average fault zone core widths are in the order of 15 to 25m which is in good agreement with surface geological mapping.

  11. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...... of the nominal feedback con-troller....

  12. Transformations in Kinship, Land Rights and Social Boundaries among the Wampar in Papua New Guinea and the Generative Agency of Children of Interethnic Marriages

    Science.gov (United States)

    Schworer, Doris Bacalzo

    2012-01-01

    Among the Wampar in Papua New Guinea, children are active participants in the dynamics of kinship and identity construction. This article explores the transformative capabilities of children of interethnic marriages, particularly those with non-Wampar fathers. It examines children's notions of belonging and rights through their practices and…

  13. 渤海湾盆地临清坳陷东部边界断裂——兰聊断层几何学、形成演化与成因机制%Geometry, formation evolution and mechanism of Lanliao fault:The boundary of eastern Linqing depression ,Bohaiwan Gulf

    Institute of Scientific and Technical Information of China (English)

    王明健; 何登发; 李文涛; 鲁人齐; 桂宝玲

    2011-01-01

    We interpreted the seismic data detailed by using drilling, logging, layering and seismic data combined with the regional geological setting and the results of previous studies on eastern Linqing depression. Based on the results of seismic interpretation we analyzed the geometry characteristics, evolutionary process and the formation kinetics backround of Lanliao fault which is the eastern boundary of Linqing depression. The research results can be described as follows; Lanliao fault is a listric normal fault which is steep in the shallow layer and low in the deep layer and detach in the basement; Lanliao fault is characterized by multiperiodic activity and the fault nature varied in different structural stage; Lanliao fault can be divided into two parts and their active time is different that the southern part began to develop in J3-K1 while the northern part in Ek-Es4; the formation and evolution of Lanliao fault is mainly controlled by the reciprocal movement of Huabei plate and its surrounding plates; the Yizenaiqi plate and Pacific plate underthrusted to the Eurasian plate which led to delamination of lithosphere and mantle up welling; the horizontal stress produced by mantle upwelling is the key reason for the formation and evolution of Lanliao fault.%充分利用钻井、测井、分层和地震资料,并结合区域地质背景和前人研究成果对临清坳陷东部地区地震资料进行了详细解释,以此为基础对临清坳陷东部边界—兰聊断层的几何学特征、形成演化及其形成的动力学背景进行了深入分析.研究认为:兰聊断层为—上陡下缓的铲式正断层,在基底发生滑脱;兰聊断层具有多期活动的特征,不同构造阶段断层性质不同;兰聊断层活动具有分段性,南段从J3-K1开始活动,而北段则是从Ek-Es4开始活动;兰聊断层的形成演化主要受华北板块与其周围板块的相互运动所控制,其中伊泽奈岐板块和太平洋板块向欧亚板块俯

  14. Phase Transformations and Earthquakes

    Science.gov (United States)

    Green, H. W.

    2011-12-01

    Phase transformations have been cited as responsible for, or at least involved in, "deep" earthquakes for many decades (although the concept of "deep" has varied). In 1945, PW Bridgman laid out in detail the string of events/conditions that would have to be achieved for a solid/solid transformation to lead to a faulting instability, although he expressed pessimism that the full set of requirements would be simultaneously achieved in nature. Raleigh and Paterson (1965) demonstrated faulting during dehydration of serpentine under stress and suggested dehydration embrittlement as the cause of intermediate depth earthquakes. Griggs and Baker (1969) produced a thermal runaway model of a shear zone under constant stress, culminating in melting, and proposed such a runaway as the origin of deep earthquakes. The discovery of Plate Tectonics in the late 1960s established the conditions (subduction) under which Bridgman's requirements for earthquake runaway in a polymorphic transformation could be possible in nature and Green and Burnley (1989) found that instability during the transformation of metastable olivine to spinel. Recent seismic correlation of intermediate-depth-earthquake hypocenters with predicted conditions of dehydration of antigorite serpentine and discovery of metastable olivine in 4 subduction zones, suggests strongly that dehydration embrittlement and transformation-induced faulting are the underlying mechanisms of intermediate and deep earthquakes, respectively. The results of recent high-speed friction experiments and analysis of natural fault zones suggest that it is likely that similar processes occur commonly during many shallow earthquakes after initiation by frictional failure.

  15. Analysis of the effects of asymmetric faults in three-phase superconducting inductive fault current limiters

    Science.gov (United States)

    Ferreira, R.; Pina, J. M.; Vilhena, N.; Arsénio, P.; Pronto, A. G.; Martins, J.

    2014-05-01

    Inductive fault current limiters of magnetic shielding type can be described in terms of the excursion in the plane defined by flux linked with primary and line current, and this methodology has been previously applied to single-phase devices. Practical applications, however, require three-phase limiters, which, for the sake of compactness, may be built by three legged cores, instead of three single phase units. This has the advantage of using well established methods of power transformers industry, but the performance of the devices depends on the type of fault, e.g. phase to ground or phase to phase. For instance, in a three legged core, a phase to ground fault affects healthy phases, and these are the most frequent faults in distribution grids, where such systems are envisaged. The effects of asymmetric faults are analysed in this paper, by means of measured excursions in the linked flux-current plane.

  16. Boundary issues

    Science.gov (United States)

    Townsend, Alan R.; Porder, Stephen

    2011-03-01

    A 2008 Transformation of the nitrogen cycle: Recent trends, questions, and potential solutions Science 320 889-92 Handoh I C and Lenton T M 2003 Periodic mid-Cretaceous oceanic anoxic events linked by oscillations of the phosphorus and oxygen biogeochemical cycles global Biogeochemical Cycles 17 1092 MacDonald G K, Bennett E M, Potter P A and Ramankutty N 2011 Agronomic phosphorus imbalances across the world_s croplands Proc. Natl Acad. Sci. 108 3086-91 Malthus T 1798 An Essay on the Principle of Population (available at http://www.gutenberg.org/browse/authors/m\\#a1411 Smil V 2000 Phosphorus in the environment: Natural flows and human interferences Annu. Rev. Energy Environ. 25 53-88 Rockström J et al 2009 A safe operating space for humanity Nature 461 472-5 Sanchez P A and Swaminathan M S 2005 Cutting world hunger in half Science 307 357-9 Schlesinger W H 2009 Planetary boundaries: Thresholds risk prolonged degradation Nature Reports Climate Change doi:10.1038/climate.2009.93 Smith V H and Schindler D W 2009 Eutrophication science: where do we go from here? Trends in Ecology and Evolution 24 201-7 Van Kauenbergh S J 2010 World Phosphate Rock Reserves and Resources (Muscle Shoals, AL: International Fertilizer Development Center) Vitousek P M, Naylor R, Crews T, David M B, Drinkwater L E, Holland E, Johnes P J, Katzenberger J, Martinelli L A, Matson P A, Nziguheba G, Ojima D, Palm C A, Robertson G P, Sanchez P A, Townsend A R, Zhang F S 2009 Nutrient Imbalances in Agricultural Development Science 324 1519-20

  17. A Practical approach for fault component network for Current and Voltage Phasor Diagram in Power Electronic Environment

    Directory of Open Access Journals (Sweden)

    Mr. Ashish Choubey

    2011-09-01

    Full Text Available In many large-scale power plants, the structure of its auxiliary power system is complex, and the coordination of its relay protections is difficult. To enhance power supply reliability for the user terminals in the case of the distribution system to avoid interference by the fault again, rapidly complete the automatic identification, positioning, automatic fault isolation, network reconfiguration until the resumption of supply of non-fault section, a microprocessor-based relay protection device has developed. As the fault component theory is widely used in microcomputer protection, and fault component exists in the network of fault component, it is necessary to build up the fault component network when short circuit fault emerging and to draw the current and voltage component phasor diagram at fault point. We proposed a special phase sequence component based on the boundary condition. We analysis the velocity according to the relationship between analysis formula and phasor diagram and current in fault component boundary conditions and sequence voltage and current in boundary conditions. The negative and zero sequence component current and voltage at fault point are the same as fault component. The positive sequence component current and voltage at fault point are different from the fault component. So we consider the positive sequences according to that sequences we analyze the fault point

  18. A Practical approach for fault component network for Current and Voltage Phasor Diagram in Power Electronic Environment

    Directory of Open Access Journals (Sweden)

    Ashish Choubey

    2011-12-01

    Full Text Available In many large-scale power plants, the structure of its auxiliary power system is complex, and the coordination of its relay protections is difficult. To enhance power supply reliability for the user terminals in the case of the distribution system to avoid interference by the fault again, rapidly complete the automatic identification, positioning, automatic fault isolation, network reconfiguration until the resumption of supply of non-fault section, a microprocessor-based relay protection device has developed. As the fault component theory is widely used in microcomputer protection, and fault component exists in the network of fault component, it is necessary to build up the fault component network when short circuit fault emerging and to draw the current and voltage component phasor diagram at fault point. We proposed a special phase sequence component based on the boundary condition. We analysis the velocity according to the relationship between analysis formula and phasor diagram and current in fault component boundary conditions and sequence voltage and current in boundary conditions. The negative and zero sequence component current and voltage at fault point are the same as fault component. The positive sequence component current and voltage at fault point are different from the fault component. So we consider the positive sequences according to that sequences we analyze the fault point.

  19. The relationship of near-surface active faulting to megathrust splay fault geometry in Prince William Sound, Alaska

    Science.gov (United States)

    Finn, S.; Liberty, L. M.; Haeussler, P. J.; Northrup, C.; Pratt, T. L.

    2010-12-01

    We interpret regionally extensive, active faults beneath Prince William Sound (PWS), Alaska, to be structurally linked to deeper megathrust splay faults, such as the one that ruptured in the 1964 M9.2 earthquake. Western PWS in particular is unique; the locations of active faulting offer insights into the transition at the southern terminus of the previously subducted Yakutat slab to Pacific plate subduction. Newly acquired high-resolution, marine seismic data show three seismic facies related to Holocene and older Quaternary to Tertiary strata. These sediments are cut by numerous high angle normal faults in the hanging wall of megathrust splay. Crustal-scale seismic reflection profiles show splay faults emerging from 20 km depth between the Yakutat block and North American crust and surfacing as the Hanning Bay and Patton Bay faults. A distinct boundary coinciding beneath the Hinchinbrook Entrance causes a systematic fault trend change from N30E in southwestern PWS to N70E in northeastern PWS. The fault trend change underneath Hinchinbrook Entrance may occur gradually or abruptly and there is evidence for similar deformation near the Montague Strait Entrance. Landward of surface expressions of the splay fault, we observe subsidence, faulting, and landslides that record deformation associated with the 1964 and older megathrust earthquakes. Surface exposures of Tertiary rocks throughout PWS along with new apatite-helium dates suggest long-term and regional uplift with localized, fault-controlled subsidence.

  20. Active faulting in apparently stable peninsular India: Rift inversion and a Holocene-age great earthquake on the Tapti Fault

    Science.gov (United States)

    Copley, Alex; Mitra, Supriyo; Sloan, R. Alastair; Gaonkar, Sharad; Reynolds, Kirsty

    2014-08-01

    We present observations of active faulting within peninsular India, far from the surrounding plate boundaries. Offset alluvial fan surfaces indicate one or more magnitude 7.6-8.4 thrust-faulting earthquakes on the Tapti Fault (Maharashtra, western India) during the Holocene. The high ratio of fault displacement to length on the alluvial fan offsets implies high stress-drop faulting, as has been observed elsewhere in the peninsula. The along-strike extent of the fan offsets is similar to the thickness of the seismogenic layer, suggesting a roughly equidimensional fault rupture. The subsiding footwall of the fault is likely to have been responsible for altering the continental-scale drainage pattern in central India and creating the large west flowing catchment of the Tapti river. A preexisting sedimentary basin in the uplifting hanging wall implies that the Tapti Fault was active as a normal fault during the Mesozoic and has been reactivated as a thrust, highlighting the role of preexisting structures in determining the rheology and deformation of the lithosphere. The slip sense of faults and earthquakes in India suggests that deformation south of the Ganges foreland basin is driven by the compressive force transmitted between India and the Tibetan Plateau. The along-strike continuation of faulting to the east of the Holocene ruptures we have studied represents a significant seismic hazard in central India.

  1. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    1999-01-01

    The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...

  2. Iowa Bedrock Faults

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This fault coverage locates and identifies all currently known/interpreted fault zones in Iowa, that demonstrate offset of geologic units in exposure or subsurface...

  3. null Faults, null Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  4. Research on Power Cable Fault Location Based on Traveling Wave Method and Wavelet Transform%基于小波变换和行波法的电缆故障测距方法研究

    Institute of Scientific and Technical Information of China (English)

    于泽; 费明

    2011-01-01

    To find out the singularity of the high coefficients of fault signal, the method of searching modulus maxima is adopted and realized the precise rangefinder fault. Through the simulation platform of MATLAB, the power cable fault system simulation model is established and obtaind the cable faults fluctuations in the end. The relative error of different locations of the different faults simulation data is less than 4% , that shows that this method is feasible and accuracy.. At the same time a kind range finder formula is put forward and developed that doesn' t include wave velocity v. That makes the calculation of the fault distance to dispense the affect from wave velocity theoretically.%采用搜索模极大值的方法,进而实现故障的精确测距.通过MATLAB仿真平台,建立了电力电缆故障系统的仿真模型,得出电缆故障波形图.不同位置的不同故障的仿真数据相对误差均小于4%,验证了该方法的可行性和准确性.同时提出并推导一种不包含波速v的测距公式,使得在计算故障距离从理论上摆脱了波速对测距结果的影响.

  5. Formal Validation of Fault Management Design Solutions

    Science.gov (United States)

    Gibson, Corrina; Karban, Robert; Andolfato, Luigi; Day, John

    2013-01-01

    The work presented in this paper describes an approach used to develop SysML modeling patterns to express the behavior of fault protection, test the model's logic by performing fault injection simulations, and verify the fault protection system's logical design via model checking. A representative example, using a subset of the fault protection design for the Soil Moisture Active-Passive (SMAP) system, was modeled with SysML State Machines and JavaScript as Action Language. The SysML model captures interactions between relevant system components and system behavior abstractions (mode managers, error monitors, fault protection engine, and devices/switches). Development of a method to implement verifiable and lightweight executable fault protection models enables future missions to have access to larger fault test domains and verifiable design patterns. A tool-chain to transform the SysML model to jpf-Statechart compliant Java code and then verify the generated code via model checking was established. Conclusions and lessons learned from this work are also described, as well as potential avenues for further research and development.

  6. The mechanics of gravity-driven faulting

    Science.gov (United States)

    Barrows, L.; Barrows, V.

    2010-04-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic rebound the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault. Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. Mechanical analysis has shown the intensity of the gravitational tectonic stress that is associated with the regional topography and lateral density variations that actually exist is comparable with the stress drops that are commonly associated with tectonic earthquakes; both are in the range of tens of bar to several hundred bar. The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the stress-causing topography and lateral density variations is equally split between the earthquake and the increase in locked-in elastic strain. The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on the fault. They must exist if gravity

  7. The mechanics of gravity-driven faulting

    Directory of Open Access Journals (Sweden)

    L. Barrows

    2010-04-01

    Full Text Available Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone. In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic rebound the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault.

    Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. Mechanical analysis has shown the intensity of the gravitational tectonic stress that is associated with the regional topography and lateral density variations that actually exist is comparable with the stress drops that are commonly associated with tectonic earthquakes; both are in the range of tens of bar to several hundred bar.

    The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the stress-causing topography and lateral density variations is equally split between the earthquake and the increase in locked-in elastic strain.

    The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on

  8. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  9. Fault tolerant computing systems

    CERN Document Server

    Randell, B

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection, damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (15 refs).

  10. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S. A.

    was to avoid a total close-down in case of the most likely faults. The second was a fault tolerant attitude control system for a micro satellite where the operation of the system is mission critical. The purpose was to avoid hazardous effects from faults and maintain operation if possible. A method...

  11. The electrical resistivity signature of a fault controlling gold mineralization and the implications for Mesozoic mineralization: a case study from the Jiaojia Fault, eastern China

    Science.gov (United States)

    Zhang, Kun; Lü, Qingtian; Yan, Jiayong; Hu, Hao; Fu, GuangMing

    2017-07-01

    We use 3D audio magnetotelluric method to the south segment of Jiaojia fault belt, and obtain the 3D electrical model of this area. Regional geophysical data were combined in an analysis of strata and major structural distribution in the study area, and included the southern segment of the Jiaojia fault zone transformed into two fault assemblages. Together with the previous studies of the ore-controlling action of the Jiaojia fault belt and deposit characteristics, the two faults are considered to be favorable metallogenic provinces, because some important features coupled with them, such as the subordinate fault intersection zone and several fault assemblages in one fault zone. It was also suggested the control action of later fault with reversed downthrows to the ore distribution. These studies have enabled us to predict the presence of two likely target regions of mineralization, and are prospecting breakthrough in the southern section of Jiaojia in the Shandong Peninsula, China.

  12. The boundary l

    Directory of Open Access Journals (Sweden)

    Muhammad Naseer

    2014-09-01

    Full Text Available The present problem is the steady boundary layer flow and heat transfer of a hyperbolic tangent fluid flowing over a vertical exponentially stretching cylinder in its axial direction. After applying usual boundary layer with a suitable similarity transformation to the given partial differential equations and the boundary conditions, a system of coupled nonlinear ordinary differential equations is obtained. This system of ordinary differential equations subject to the boundary conditions is solved with the help of Runge–Kutta–Fehlberg method. The effects of the involved parameters such as Reynolds numbers, Prandtl numbers, Weissenberg numbers and the natural convection parameter are presented through the graphs. The associated physical properties on the flow and heat transfer characteristics that is the skin friction coefficient and Nusselt numbers are presented for different parameters.

  13. Finite BMS transformations

    Energy Technology Data Exchange (ETDEWEB)

    Barnich, Glenn [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes,Campus Plaine C.P. 231, B-1050 Bruxelles (Belgium); Troessaert, Cédric [Centro de Estudios Científicos (CECs),Arturo Prat 514, Valdivia (Chile)

    2016-03-24

    The action of finite BMS and Weyl transformations on the gravitational data at null infinity is worked out in three and four dimensions in the case of an arbitrary conformal factor for the boundary metric induced on Scri.

  14. Systematic Fault Tolerant Control Based on Adaptive Thau Observer Estimation for Quadrotor Uavs

    Directory of Open Access Journals (Sweden)

    Cen Zhaohui

    2015-03-01

    Full Text Available A systematic fault tolerant control (FTC scheme based on fault estimation for a quadrotor actuator, which integrates normal control, active and passive FTC and fault parking is proposed in this paper. Firstly, an adaptive Thau observer (ATO is presented to estimate the quadrotor rotor fault magnitudes, and then faults with different magnitudes and time-varying natures are rated into corresponding fault severity levels based on the pre-defined fault-tolerant boundaries. Secondly, a systematic FTC strategy which can coordinate various FTC methods is designed to compensate for failures depending on the fault types and severity levels. Unlike former stand-alone passive FTC or active FTC, our proposed FTC scheme can compensate for faults in a way of condition-based maintenance (CBM, and especially consider the fatal failures that traditional FTC techniques cannot accommodate to avoid the crashing of UAVs. Finally, various simulations are carried out to show the performance and effectiveness of the proposed method.

  15. Evolution of the Puente Hills Thrust Fault

    Science.gov (United States)

    Bergen, K. J.; Shaw, J. H.; Dolan, J. F.

    2013-12-01

    This study aims to assess the evolution of the blind Puente Hills thrust fault system (PHT) by determining its age of initiation, lateral propagation history, and changes in slip rate over time. The PHT presents one of the largest seismic hazards in the United States, given its location beneath downtown Los Angeles. The PHT is comprised of three fault segments: the Los Angeles (LA), Santa Fe Springs (SFS), and Coyote Hills (CH). The LA and SFS segments are characterized by growth stratigraphy where folds formed by uplift on the fault segments have been continually buried by sediment from the Los Angeles and San Gabriel rivers. The CH segment has developed topography and is characterized by onlapping growth stratigraphy. This depositional setting gives us the unique opportunity to measure uplift on the LA and SFS fault segments, and minimum uplift on the CH fault segment, as the difference in sediment thicknesses across the buried folds. We utilize depth converted oil industry seismic reflection data to image the fold geometries. Identifying time-correlative stratigraphic markers for slip rate determination in the basin has been a problem for researchers in the past, however, as the faunal assemblages observed in wells are time-transgressive by nature. To overcome this, we utilize the sequence stratigraphic model and well picks of Ponti et al. (2007) as a basis for mapping time-correlative sequence boundaries throughout our industry seismic reflection data from the present to the Pleistocene. From the Pleistocene to Miocene we identify additional sequence boundaries in our seismic reflection data from imaged sequence geometries and by correlating industry well formation tops. The sequence and formation top picks are then used to build 3-dimensional surfaces in the modeling program Gocad. From these surfaces we measure the change in thicknesses across the folds to obtain uplift rates between each sequence boundary. Our results show three distinct phases of

  16. Strong paleoearthquakes along the Talas-Fergana Fault, Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    A.M. Korzhenkov

    2014-02-01

    Full Text Available The Talas-Fergana Fault, the largest strike-slip structure in Centred. Asia, forms an obliquely oriented boundary between the northeastern and southwestern parts of the Tianshan mountain belt. The fault underwent active right-lateral strike-slip during the Paleozoic, with right-lateral movements being rejuvenated in the Late Cenozoic. Tectonic movements along the intracontinental strike-slip faults contribute to absorb part of the regional crustal shortening linked to the India-Eurasia collision; knowledge of strike-slip motions along the Talas-Fergana Fault are necessary for a complete assessment of the active deformation of the Tianshan orogen. To improve our understanding of the intracontinental deformation of the Tianshan mountain belt and the occurrence of strong earthquakes along the whole length of the Talas-Fergana Fault, we identify features of relief arising during strong paleoearthquakes along the Talas-Fergana Fault, fault segmentation, the length of seismogenic ruptures, and the energy and age of ancient catastrophes. We show that during neotectonic time the fault developed as a dextral strike-slip fault, with possible dextral displacements spreading to secondary fault planes north of the main fault trace. We determine rates of Holocene and Late Pleistocene dextral movements, and our radiocarbon dating indicates tens of strong earthquakes occurring along the fault zone during arid interval of 15800 years. The reoccurrence of strong earthquakes along the Talas-Fergana Fault zone during the second half of the Holocene is about 300 years. The next strong earthquake along the fault will most probably occur along its southeastern chain during the next several decades. Seismotectonic deformation parameters indicate that M > 7 earthquakes with oscillation intensity I > IX have occurred.

  17. Information Based Fault Diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2008-01-01

    Fault detection and isolation, (FDI) of parametric faults in dynamic systems will be considered in this paper. An active fault diagnosis (AFD) approach is applied. The fault diagnosis will be investigated with respect to different information levels from the external inputs to the systems....... These inputs are disturbance inputs, reference inputs and auxilary inputs. The diagnosis of the system is derived by an evaluation of the signature from the inputs in the residual outputs. The changes of the signatures form the external inputs are used for detection and isolation of the parametric faults....

  18. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

    Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

  19. The January 2010 Haiti mainshock-aftershock sequence: Positive feedback between faults in strain-partitioned transpression

    Science.gov (United States)

    Seeber, L.; Waldhauser, F.; Diehl, T.; Hjorleifsdottir, V.; Nettles, M.

    2010-12-01

    The Caribbean and North American plates converge ENE across the broad plate boundary in western Hispaniola. This motion is partitioned between a pair of parallel sinistral ~E-W striking transform faults and a set of NW-SE striking thrust-folds. The January 2010 M7.0 earthquake sequence in Haiti activated both these structural elements, shifting from mostly sinistral during the mainshock to pure thrusting in the aftershocks. Teleseismic waveforms of the mainshock point to a rupture on a WSW-striking segment of the Enriquillo-Plaintain Garden Fault (EPGF), dipping steeply north and mostly sinistral with a reverse component. Structural and coseismic surface deformation and lack of surface rupture, have lead to different interpretations. Which faults were activated in the sequence remains controversial. We greatly improved hypocenter resolution for the mainshock and 56 aftershocks (Mw 4.2-5.9) that occurred within two months by applying a teleseismic double-difference algorithm to the NEIC phase arrival times. Relative location uncertainties at the 90% confidence level are, on average, 1.9 km laterally and 1.3 km vertically. Aftershocks form two clusters, the smaller one near and east of the mainshock epicenter and the larger one about 30 km to the west and beyond. The gap between them is approximately the inferred main-rupture length. Focal mechanisms in both clusters exhibit nearly pure thrusting with planes striking from W to NW, except for one similar to and near the mainshock. Absolute location uncertainties, however, remain large so that the correlation between hypocenters and faults is interpretative. We place the relocated epicentres so that the two clusters correlate with restraining portions of the EPGF and the mainshock epicenter is on the fault trace, near the NEIC epicenter and well within the range of possible absolute locations. In agreement with more recent earthquake locations from local seismic stations and with the expected placement of thrust

  20. Earthquake fault superhighways

    Science.gov (United States)

    Robinson, D. P.; Das, S.; Searle, M. P.

    2010-10-01

    Motivated by the observation that the rare earthquakes which propagated for significant distances at supershear speeds occurred on very long straight segments of faults, we examine every known major active strike-slip fault system on land worldwide and identify those with long (> 100 km) straight portions capable not only of sustained supershear rup