Corrosion and Rupture of Steam Generator Tubings in PWRs

International Nuclear Information System (INIS)

Hwang, Seong Sik; Kim, Hong Pyo

2007-08-01

This report is intended to provide corrosion engineers in the filed of nuclear energy with information on the corrosion and rupture behavior of steam generator tubing in PWRs. Various types of corrosion in PWR steam generator tubing have been reported all around the world, and countermeasures such as the addition of corrosion inhibitors, a water chemistry control, a tube plugging and sleeving have been applied. Steam generators equipped with alloy 600 tubing, which are not so resistant to a stress corrosion cracking (SCC), have generally been replaced with new steam generators made of alloy 690 TT (Thermally treated). Pull tube examination results which were performed of KAERI are summarized. The tubes were affected by a pitting, SCC, and a denting. Nondestructive examination method for the tubes and repair techniques are also reviewed. In addition, the regulatory guidance of some countries are reviewed. As a part of a tube integrity project in Korea, some results on a tube rupture and leak behaviors for axial cracks are also mentioned

Uncertainty analysis for probabilistic steam generators tube rupture in LBB applications

Energy Technology Data Exchange (ETDEWEB)

Durbec, V.; Pitner, P.; Pages, D. [Electricite de France, 78 - Chatou (France). Research and Development Div.; Riffard, T. [Electricite de France, 69 - Villeurbanne (France). Engineering and Construction Div.; Flesch, B. [Electricite de France, 92 - Paris la Defense (France). Generation and Transmission Div.

1997-10-01

Steam Generators (SG) of Pressurized Water Reactors have experienced world wide various types of tube degradations, mainly from stress corrosion cracking; because of this damage, primary-secondary leakage or tube rupture can occur. Safety against the risk of tube rupture is achieved through a combination of periodic in-service inspections (eddy current testing), surveillance of leaks during operation (leak before break concept) and tube plugging. In order to optimize the tube bundle SG maintenance, Electricite de France has developed a specific software named COMPROMIS. The model, based on probabilistic fracture mechanics makes it possible to quantify the influence of in service inspections and maintenance work on the risk of a SG Tube Rupture (SGTR), taking all significant parameters into account as random variables (initial defect size distribution, reliability of non-destructive examinations, crack initiation and propagation, critical sizes, leak before risk of break, etc...). This paper focuses on the leak rate calculation module and presents a sensitivity study of the influence of the leak before break on the conditional failure probability. (author) 8 refs.

Uncertainty analysis for probabilistic steam generators tube rupture in LBB applications

International Nuclear Information System (INIS)

Durbec, V.; Pitner, P.; Pages, D.; Riffard, T.; Flesch, B.

1997-10-01

Steam Generators (SG) of Pressurized Water Reactors have experienced world wide various types of tube degradations, mainly from stress corrosion cracking; because of this damage, primary-secondary leakage or tube rupture can occur. Safety against the risk of tube rupture is achieved through a combination of periodic in-service inspections (eddy current testing), surveillance of leaks during operation (leak before break concept) and tube plugging. In order to optimize the tube bundle SG maintenance, Electricite de France has developed a specific software named COMPROMIS. The model, based on probabilistic fracture mechanics makes it possible to quantify the influence of in service inspections and maintenance work on the risk of a SG Tube Rupture (SGTR), taking all significant parameters into account as random variables (initial defect size distribution, reliability of non-destructive examinations, crack initiation and propagation, critical sizes, leak before risk of break, etc...). This paper focuses on the leak rate calculation module and presents a sensitivity study of the influence of the leak before break on the conditional failure probability. (author)

Influence of steam generator tube ruptures during semiscale loss-of-coolant experiments

International Nuclear Information System (INIS)

Cozzuol, J.M.; Larson, T.K.

1978-01-01

Tests which simulated rupture of steam generator tubes during loss-of-coolant experiments in a PWR type system have been conducted in the Semiscale Mod-1 system. Analysis of test data indicates that high rod cladding temperatures occured only for a band of tube ruptures (between 12 and 20 tubes) and that the peak cladding temperatures attained within this band were strongly dependent on the magnitude of the tube rupture flow rates. Maximum cladding temperature of about 1255 K was observed for tests which simulated tube ruptures within this narrow band. (author)

Evaluation of tube rupture simulation test (TRUST-1) for FBR steam generators

Energy Technology Data Exchange (ETDEWEB)

Hayashida, Yoshihiko; Hamada, Hirotsugu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1996-06-01

The intermediate water leak in an FBR Steam Generator (SG) causes a high temperature and corrosive sodium-water reaction jet. In such cases, it is necessary to evaluate the wastage and overheating rupture behavior of heat transfer tubes. Especially, in the large SG that aims at high temperature of sodium and high temperature/pressure of water, the establishment of the rational evaluation method is important. In this paper, as a basic experiment to make clear the phenomenon of overheating rupture, tests and analysis of Tube Rupture Simulation Test-1 (TRUST-1) were conducted. TRUST-1 simulates the overheating rupture of the tube made of Mod.9Cr-1Mo steel by nitrogen gas pressurization and quick induction heating. The result of TRUST-1 are as follows: (1) The breaking strength predicted by the internal pressure is larger than the tensile strength of the tube material. (2) The margin of the breaking strength from the tensile strength of the tube material has a tendency of decreasing with the heating rate, especially in the lower temperature region. (3) Using an theoretical formula that is deduced from the steady creep model and appropriate experimental coefficients that are determined by the test data, the breaking strength can be reasonably evaluated. (author)

Experience and modeling of radioactivity transport following steam generator tube rupture

International Nuclear Information System (INIS)

Hopenfeld, J.

1985-01-01

A review of the capabilities of the CITADEL computer code as well as plant experience to project radioactivity releases following a steam generator tube rupture in pressurized-water reactors shows that certain experimental data are needed for reliable offsite dose predictions. This article defines five parameters that are the key for such predictions and discusses the functional dependence of these parameters on various operational variables. The above parameters can be used in conjuction with CITADEL or they can be inserted in the appropriate equations, which then can be programmed conveniently as a subroutine in thermal-hydraulic system codes. A joint Westinghouse Electric Corporation, Electric Power Research Institute, and Nuclear Regulatory Commission program aimed at obtaining the five parameters empirically is described

Dynamic rupture models of subduction zone earthquakes with off-fault plasticity

Science.gov (United States)

Wollherr, S.; van Zelst, I.; Gabriel, A. A.; van Dinther, Y.; Madden, E. H.; Ulrich, T.

2017-12-01

Modeling tsunami-genesis based on purely elastic seafloor displacement typically underpredicts tsunami sizes. Dynamic rupture simulations allow to analyse whether plastic energy dissipation is a missing rheological component by capturing the complex interplay of the rupture front, emitted seismic waves and the free surface in the accretionary prism. Strike-slip models with off-fault plasticity suggest decreasing rupture speed and extensive plastic yielding mainly at shallow depths. For simplified subduction geometries inelastic deformation on the verge of Coulomb failure may enhance vertical displacement, which in turn favors the generation of large tsunamis (Ma, 2012). However, constraining appropriate initial conditions in terms of fault geometry, initial fault stress and strength remains challenging. Here, we present dynamic rupture models of subduction zones constrained by long-term seismo-thermo-mechanical modeling (STM) without any a priori assumption of regions of failure. The STM model provides self-consistent slab geometries, as well as stress and strength initial conditions which evolve in response to tectonic stresses, temperature, gravity, plasticity and pressure (van Dinther et al. 2013). Coseismic slip and coupled seismic wave propagation is modelled using the software package SeisSol (www.seissol.org), suited for complex fault zone structures and topography/bathymetry. SeisSol allows for local time-stepping, which drastically reduces the time-to-solution (Uphoff et al., 2017). This is particularly important in large-scale scenarios resolving small-scale features, such as the shallow angle between the megathrust fault and the free surface. Our dynamic rupture model uses a Drucker-Prager plastic yield criterion and accounts for thermal pressurization around the fault mimicking the effect of pore pressure changes due to frictional heating. We first analyze the influence of this rheology on rupture dynamics and tsunamigenic properties, i.e. seafloor

Dynamic rupture modeling of the M7.2 2010 El Mayor-Cucapah earthquake: Comparison with a geodetic model

Science.gov (United States)

Kyriakopoulos, Christos; Oglesby, David D.; Funning, Gareth J.; Ryan, Kenneth

2017-01-01

The 2010 Mw 7.2 El Mayor-Cucapah earthquake is the largest event recorded in the broader Southern California-Baja California region in the last 18 years. Here we try to analyze primary features of this type of event by using dynamic rupture simulations based on a multifault interface and later compare our results with space geodetic models. Our results show that starting from homogeneous prestress conditions, slip heterogeneity can be achieved as a result of variable dip angle along strike and the modulation imposed by step over segments. We also considered effects from a topographic free surface and find that although this does not produce significant first-order effects for this earthquake, even a low topographic dome such as the Cucapah range can affect the rupture front pattern and fault slip rate. Finally, we inverted available interferometric synthetic aperture radar data, using the same geometry as the dynamic rupture model, and retrieved the space geodetic slip distribution that serves to constrain the dynamic rupture models. The one to one comparison of the final fault slip pattern generated with dynamic rupture models and the space geodetic inversion show good agreement. Our results lead us to the following conclusion: in a possible multifault rupture scenario, and if we have first-order geometry constraints, dynamic rupture models can be very efficient in predicting large-scale slip heterogeneities that are important for the correct assessment of seismic hazard and the magnitude of future events. Our work contributes to understanding the complex nature of multifault systems.

Realistic analysis of steam generator tube rupture accident in Angra-1 reactor

International Nuclear Information System (INIS)

Fontes, S.W.F.

1989-01-01

This paper presents the analysis of different scenarios for a Steam Generator Tube Rupture accident (SGTR) in Angra-1 NPP. The results and conclusions will be used as support in the preparation of the emergency situation programs for the plant. For the analysis a SGTR simulation was performed with RETRAN-02 code. The results indicated that the core integrity and the plant itself will not affect by small ruptures in SG tubes. For large ruptures the analysis demonstrated that the accident may have harmful consequences if the operator do not actuate effectively since the initial moments of the accidents. (author) [pt

Computing broadband accelerograms using kinematic rupture modeling

International Nuclear Information System (INIS)

Ruiz Paredes, J.A.

2007-05-01

In order to make the broadband kinematic rupture modeling more realistic with respect to dynamic modeling, physical constraints are added to the rupture parameters. To improve the slip velocity function (SVF) modeling, an evolution of the k -2 source model is proposed, which consists to decompose the slip as a sum of sub-events by band of k. This model yields to SVF close to the solution proposed by Kostrov for a crack, while preserving the spectral characteristics of the radiated wave field, i.e. a w 2 model with spectral amplitudes at high frequency scaled to the coefficient of directivity C d . To better control the directivity effects, a composite source description is combined with a scaling law defining the extent of the nucleation area for each sub-event. The resulting model allows to reduce the apparent coefficient of directivity to a fraction of C d , as well as to reproduce the standard deviation of the new empirical attenuation relationships proposed for Japan. To make source models more realistic, a variable rupture velocity in agreement with the physics of the rupture must be considered. The followed approach that is based on an analytical relation between the fracture energy, the slip and the rupture velocity, leads to higher values of the peak ground acceleration in the vicinity of the fault. Finally, to better account for the interaction of the wave field with the geological medium, a semi-empirical methodology is developed combining a composite source model with empirical Green functions, and is applied to the Yamaguchi, M w 5.9 earthquake. The modeled synthetics reproduce satisfactorily well the observed main characteristics of ground motions. (author)

Rupture Complexity Promoted by Damaged Fault Zones in Earthquake Cycle Models

Science.gov (United States)

Idini, B.; Ampuero, J. P.

2017-12-01

Pulse-like ruptures tend to be more sensitive to stress heterogeneity than crack-like ones. For instance, a stress-barrier can more easily stop the propagation of a pulse than that of a crack. While crack-like ruptures tend to homogenize the stress field within their rupture area, pulse-like ruptures develop heterogeneous stress fields. This feature of pulse-like ruptures can potentially lead to complex seismicity with a wide range of magnitudes akin to the Gutenberg-Richter law. Previous models required a friction law with severe velocity-weakening to develop pulses and complex seismicity. Recent dynamic rupture simulations show that the presence of a damaged zone around a fault can induce pulse-like rupture, even under a simple slip-weakening friction law, although the mechanism depends strongly on initial stress conditions. Here we aim at testing if fault zone damage is a sufficient ingredient to generate complex seismicity. In particular, we investigate the effects of damaged fault zones on the emergence and sustainability of pulse-like ruptures throughout multiple earthquake cycles, regardless of initial conditions. We consider a fault bisecting a homogeneous low-rigidity layer (the damaged zone) embedded in an intact medium. We conduct a series of earthquake cycle simulations to investigate the effects of two fault zone properties: damage level D and thickness H. The simulations are based on classical rate-and-state friction, the quasi-dynamic approximation and the software QDYN (https://github.com/ydluo/qdyn). Selected fully-dynamic simulations are also performed with a spectral element method. Our numerical results show the development of complex rupture patterns in some damaged fault configurations, including events of different sizes, as well as pulse-like, multi-pulse and hybrid pulse-crack ruptures. We further apply elasto-static theory to assess how D and H affect ruptures with constant stress drop, in particular the flatness of their slip profile

Development of tube rupture evaluation code for FBR steam generator (II). Modification of heat transfer model in sodium side

International Nuclear Information System (INIS)

Hamada, H.; Kurihara, A.

2003-05-01

The thermal effect of sodium-water reaction jet on neighboring heat transfer tubes was examined to rationally evaluate the structural integrity of the tube for overheating rupture under a water leak in an FBR steam generator. Then, the development of new heat transfer model and the application analysis were carried out. Main results in this paper are as follows. (1) The evaluation method of heat flux and heat transfer coefficient (HTC) on the tube exposed to reaction jet was developed. By using the method, it was confirmed that the heat flux could be realistically evaluated in comparison with the previous method. (2) The HTC between reaction jet and the tube was theoretically examined in the two-phase flow model, and new heat transfer model considering the effect of fluid temperature and cover gas pressure was developed. By applying the model, a tentative experimental correlation was conservatively obtained by using SWAT-1R test data. (3) The new model was incorporated to the Tube Rupture Evaluation Code (TRUE), and the conservatism of the model was confirmed by using sodium-water reaction data such as the SWAT-3 tests. (4) In the application analysis of the PFR large leak event, there was no significant difference of calculation results between the new model and previous one; the importance of depressurization in the tube was confirmed. (5) In the application analysis of the Monju evaporator, it was confirmed that the calculation result in the previous model would be more conservative than that in the new one and that the maximum cumulative damage of 25% could be reduced in the new model. (author)

Investigation of a steam generator tube rupture sequence using VICTORIA

International Nuclear Information System (INIS)

Bixler, N.E.; Erickson, C.M.; Schaperow, J.H.

1995-01-01

VICTORIA-92 is a mechanistic computer code for analyzing fission product behavior within the reactor coolant system (RCS) during a severe reactor accident. It provides detailed predictions of the release of radionuclides and nonradioactive materials from the core and transport of these materials within the RCS. The modeling accounts for the chemical and aerosol processes that affect radionuclide behavior. Coupling of detailed chemistry and aerosol packages is a unique feature of VICTORIA; it allows exploration of phenomena involving deposition, revaporization, and re-entrainment that cannot be resolved with other codes. The purpose of this work is to determine the attenuation of fission products in the RCS and on the secondary side of the steam generator in an accident initiated by a steam generator tube rupture (SGTR). As a class, bypass sequences have been identified in NUREG-1150 as being risk dominant for the Surry and Sequoyah pressurized water reactor (PWR) plants

Validation of statistical models for creep rupture by parametric analysis

Energy Technology Data Exchange (ETDEWEB)

Bolton, J., E-mail: john.bolton@uwclub.net [65, Fisher Ave., Rugby, Warks CV22 5HW (United Kingdom)

2012-01-15

Statistical analysis is an efficient method for the optimisation of any candidate mathematical model of creep rupture data, and for the comparative ranking of competing models. However, when a series of candidate models has been examined and the best of the series has been identified, there is no statistical criterion to determine whether a yet more accurate model might be devised. Hence there remains some uncertainty that the best of any series examined is sufficiently accurate to be considered reliable as a basis for extrapolation. This paper proposes that models should be validated primarily by parametric graphical comparison to rupture data and rupture gradient data. It proposes that no mathematical model should be considered reliable for extrapolation unless the visible divergence between model and data is so small as to leave no apparent scope for further reduction. This study is based on the data for a 12% Cr alloy steel used in BS PD6605:1998 to exemplify its recommended statistical analysis procedure. The models considered in this paper include a) a relatively simple model, b) the PD6605 recommended model and c) a more accurate model of somewhat greater complexity. - Highlights: Black-Right-Pointing-Pointer The paper discusses the validation of creep rupture models derived from statistical analysis. Black-Right-Pointing-Pointer It demonstrates that models can be satisfactorily validated by a visual-graphic comparison of models to data. Black-Right-Pointing-Pointer The method proposed utilises test data both as conventional rupture stress and as rupture stress gradient. Black-Right-Pointing-Pointer The approach is shown to be more reliable than a well-established and widely used method (BS PD6605).

Intentional back flow effects on ruptured steam generator cooldown during a SGTR event for KSNP

International Nuclear Information System (INIS)

Kim, C.W.; Park, S.J.; Choi, C.J.; Seo, J.T.

2004-01-01

For an optimum recovery from a steam generator tube rupture (SGTR) event, the operators are directed to isolate the steam generator (SG) with ruptured tube as early as possible to minimize the radioactive material release. However, the reactor coolant system (RCS) cooldown and depressurization to the shutdown cooling system (SCS) operation conditions using the intact SG only are hard to achieve unless the ruptured SG is properly cooled since the ruptured SG, which is isolated by operator, remains at high temperature even though the RCS has been cooled down. The effects of intentional back flow from the SG secondary side to the RCS through the ruptured U-tube on the the ruptured SG cooldown were evaluated for the pressurized light water reactor, especially for the Korean standard nuclear power plant (KSNP). In order to evaluate the back flow effect, a series of analyses was conducted using the RELAP5/MOD3 computer code. For the first stage of the analysis, the cooldown process by natural circulation in the SG secondary side was simulated for the initial conditions of the ruptured SG cooldown. In the next analysis stage, two methods of the ruptured SG cooldown by using back flow after RCS cooldown were evaluated. One utilizes the steam condensation on the uncovered U-tube surface, and the other is a SG drain and fill. In the former method, SG tubes are exposed to the steam space by draining SG secondary water into the RCS in order to condense the steam directly onto the uncovered tubes. This method showed that the steam condensation decreased SG secondary pressure and temperature rapidly, demonstrating its effectiveness for cooling. However, this process has a limited applicability if the rupture is located at the lower region. The latter method, draining by back flow and filling using the feedwater system was also found to be effective in ruptured SG cooldown and depressurization even if the rupture occurred at the top of the U-tube. It is concluded that the

CITADEL: a computer code for the analysis of iodine behavior in steam generator tube rupture accidents

International Nuclear Information System (INIS)

1982-04-01

The computer code CITADEL was written to analyze iodine behavior during steam generator tube rupture accidents. The code models the transport and deposition of iodine from its point of escape at the steam generator primary break until its release to the environment. This report provides a brief description of the code including its input requirements and the nature and form of its output. A user's guide describing the manner in which the input data are required to be set up to run the code is also provided

Radioactivity transport following steam generator tube rupture

International Nuclear Information System (INIS)

Hopenfeld, J.

1985-03-01

A review of the capabilities of the CITADEL computer code as well as plant experience to project radioactivity releases following a steam generator tube rupture in PWR's shows that certain experimental data are needed for reliable off-site dose predictions. This article defines five parameters which are the key for such predictions and discusses the functional dependence of these parameters on various operational variables. The above parameters can be used in conjunction with CITADEL or they can be inserted in the appropriate equations which then conveniently can be programmed as a subroutine in thermal-hydraulic system codes. A joint Westinghouse, Electric Power Research Institute and Nuclear Regulatory Commission Program aimed at obtaining the five parameters empirically is described

Comparative Analyses on OPR1000 Steam Generator Tube Rupture Event Emergency Operational Guideline

International Nuclear Information System (INIS)

Lee, Sang Won; Bae, Yeon Kyoung; Kim, Hyeong Teak

2006-01-01

The Steam Generator Tube Rupture (SGTR) event is one of the important scenarios in respect to the radiation release to the environment. When the SGTR occurs, containment integrity is not effective because of the direct bypass of containment via the ruptured steam generator to the MSSV and MSADV. To prevent this path, the Emergency Operational Guideline of OPR1000 indicates the use of Turbine Bypass Valves (TBVs) as an effective means to depressurize the main steam line and prevent the lifting of MSSV. However, the TBVs are not operable when the offsite power is not available (LOOP). In this situation, the RCS cool-down is achieved by opening the both intact and ruptured SG MSADV. But this action causes the large amount of radiation release to the environment. To minimize the radiation release to the environment, KSNP EOG adopts the improved strategy when the SGTR concurrently with LOOP is occurred. However, these procedures show some duplicated procedure and branch line that might confusing the operator for optimal recovery action. So, in this paper, the comparative analysis on SGTR and SGTR with LOOP is performed and optimized procedure is proposed

Standards for Documenting Finite‐Fault Earthquake Rupture Models

KAUST Repository

Mai, Paul Martin

2016-04-06

In this article, we propose standards for documenting and disseminating finite‐fault earthquake rupture models, and related data and metadata. A comprehensive documentation of the rupture models, a detailed description of the data processing steps, and facilitating the access to the actual data that went into the earthquake source inversion are required to promote follow‐up research and to ensure interoperability, transparency, and reproducibility of the published slip‐inversion solutions. We suggest a formatting scheme that describes the kinematic rupture process in an unambiguous way to support subsequent research. We also provide guidelines on how to document the data, metadata, and data processing. The proposed standards and formats represent a first step to establishing best practices for comprehensively documenting input and output of finite‐fault earthquake source studies.

Standards for Documenting Finite‐Fault Earthquake Rupture Models

KAUST Repository

Mai, Paul Martin; Shearer, Peter; Ampuero, Jean‐Paul; Lay, Thorne

2016-01-01

In this article, we propose standards for documenting and disseminating finite‐fault earthquake rupture models, and related data and metadata. A comprehensive documentation of the rupture models, a detailed description of the data processing steps, and facilitating the access to the actual data that went into the earthquake source inversion are required to promote follow‐up research and to ensure interoperability, transparency, and reproducibility of the published slip‐inversion solutions. We suggest a formatting scheme that describes the kinematic rupture process in an unambiguous way to support subsequent research. We also provide guidelines on how to document the data, metadata, and data processing. The proposed standards and formats represent a first step to establishing best practices for comprehensively documenting input and output of finite‐fault earthquake source studies.

Reliability assessment of creep rupture life for Gr. 91 steel

International Nuclear Information System (INIS)

Kim, Woo-Gon; Park, Jae-Young; Kim, Seon-Jin; Jang, Jinsung

2013-01-01

Highlights: • Statistical analysis of a number of creep rupture data based on Z parameter. • Determination of the constant C in LM parameter and long-term creep life prediction. • Generation of random variables for Z s and Z cr by Monte-Carlo simulation in a SCRI model. • Examples for design application were reasonably drawn from the viewpoints of reliability. - Abstract: This paper presents reliability assessment of the long-term creep life of Gr. 91 steel, which is a major structural material for high temperature structural components of Generation-IV reactor systems. A number of creep rupture data for Gr. 91 steel were collected through literature surveys, and the long-term creep life was predicted by Larson–Miller parameter. A “Z parameter” method was used to describe the magnitude of the deviation of the creep rupture data to a master curve. A “Service Condition-creep Rupture property Interference (SCRI) model” based on the Z parameter was used to simultaneously consider the scattering of the creep rupture data of materials and the fluctuations of service conditions in reliability assessment. A statistical analysis of the creep rupture data was conducted by the Z parameter. To carry out the SCRI model, a number of random variables for Z s describing service conditions and Z cr describing the dispersion of the creep rupture data were generated using a Monte-Carlo simulation technique. As examples for application, the creep rupture life under a certain service conditions of Gr. 91 steel was reasonably drawn from the viewpoints of reliability

Potential steam generator tube rupture in the presence of severe accident thermal challenge and tube flaws due to foreign object wear

International Nuclear Information System (INIS)

Liao, Y.; Guentay, S.

2009-01-01

This study develops a methodology to assess the probability for the degraded PWR steam generator to rupture first in the reactor coolant pressure boundary, under severe accident conditions with counter-current natural circulating high temperature gas in the hot leg and SG tubes. The considered SG tube flaws are caused by foreign object wear, which in recent years has emerged as a major inservice degradation mechanism for the new generation tubing materials. The first step develops the statistical distributions for the flaw frequency, size, and the flaw location with respect to the tube length and the tube's tubesheet position, based on data of hundreds of flaws reported in numerous SG inservice inspection reports. The next step performs thermal-hydraulic analysis using the MELCOR code and recent CFD findings to predict the thermal challenge to the degraded tubes and the tube-to-tube difference in thermal response at the SG entrance. The final step applies the creep rupture models in the Monte Carlo random walk to test the potential for the degraded SG to rupture before the surge line. The mean and range of the SG tube rupture probability can be applied to estimate large early release frequency in probabilistic safety assessment.

The effect of the number of condensed phases modeled on aerosol behavior during an induced steam generator tube rupture sequence

International Nuclear Information System (INIS)

Bixler, N.E.; Schaperow, J.H.

1998-06-01

VICTORIA is a mechanistic computer code designed to analyze fission product behavior within a nuclear reactor coolant system (RCS) during a severe accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS. A recently completed independent peer review of VICTORIA, while confirming the overall adequacy of the code, recommended a number of modeling improvements. One of these recommendations, to model three rather than a single condensed phase, is the focus of the work reported here. The recommendation has been implemented as an option so that either a single or three condensed phases can be treated. Both options have been employed in the study of fission product behavior during an induced steam generator tube rupture sequence. Differences in deposition patterns and mechanisms predicted using these two options are discussed

Modelling ground rupture due to groundwater withdrawal: applications to test cases in China and Mexico

Science.gov (United States)

Franceschini, A.; Teatini, P.; Janna, C.; Ferronato, M.; Gambolati, G.; Ye, S.; Carreón-Freyre, D.

2015-11-01

The stress variation induced by aquifer overdraft in sedimentary basins with shallow bedrock may cause rupture in the form of pre-existing fault activation or earth fissure generation. The process is causing major detrimental effects on a many areas in China and Mexico. Ruptures yield discontinuity in both displacement and stress field that classic continuous finite element (FE) models cannot address. Interface finite elements (IE), typically used in contact mechanics, may be of great help and are implemented herein to simulate the fault geomechanical behaviour. Two main approaches, i.e. Penalty and Lagrangian, are developed to enforce the contact condition on the element interface. The incorporation of IE incorporation into a three-dimensional (3-D) FE geomechanical simulator shows that the Lagrangian approach is numerically more robust and stable than the Penalty, thus providing more reliable solutions. Furthermore, the use of a Newton-Raphson scheme to deal with the non-linear elasto-plastic fault behaviour allows for quadratic convergence. The FE - IE model is applied to investigate the likely ground rupture in realistic 3-D geologic settings. The case studies are representative of the City of Wuxi in the Jiangsu Province (China), and of the City of Queretaro, Mexico, where significant land subsidence has been accompanied by the generation of several earth fissures jeopardizing the stability and integrity of the overland structures and infrastructure.

Creep rupture behavior of unidirectional advanced composites

Science.gov (United States)

Yeow, Y. T.

1980-01-01

A 'material modeling' methodology for predicting the creep rupture behavior of unidirectional advanced composites is proposed. In this approach the parameters (obtained from short-term tests) required to make the predictions are the three principal creep compliance master curves and their corresponding quasi-static strengths tested at room temperature (22 C). Using these parameters in conjunction with a failure criterion, creep rupture envelopes can be generated for any combination of in-plane loading conditions and ambient temperature. The analysis was validated experimentally for one composite system, the T300/934 graphite-epoxy system. This was done by performing short-term creep tests (to generate the principal creep compliance master curves with the time-temperature superposition principle) and relatively long-term creep rupture tensile tests of off-axis specimens at 180 C. Good to reasonable agreement between experimental and analytical results is observed.

Rupture of the atherosclerotic plaque: does a good animal model exist?

NARCIS (Netherlands)

Cullen, Paul; Baetta, Roberta; Bellosta, Stefano; Bernini, Franco; Chinetti, Giulia; Cignarella, Andrea; von Eckardstein, Arnold; Exley, Andrew; Goddard, Martin; Hofker, Marten; Hurt-Camejo, Eva; Kanters, Edwin; Kovanen, Petri; Lorkowski, Stefan; McPheat, William; Pentikäinen, Markku; Rauterberg, Jürgen; Ritchie, Andrew; Staels, Bart; Weitkamp, Benedikt; de Winther, Menno

2003-01-01

By its very nature, rupture of the atherosclerotic plaque is difficult to study directly in humans. A good animal model would help us not only to understand how rupture occurs but also to design and test treatments to prevent it from happening. However, several difficulties surround existing models

Steam generator secondary pH during a steam generator tube rupture

International Nuclear Information System (INIS)

Adams, J.P.; Peterson, E.S.

1991-12-01

The Nuclear Regulatory Commission requires utilizes to determine the response of a pressurized water reactor to a steam generator tube rupture (SGTR) as part of the safety analysis for the plant. The SGTR analysis includes assumptions regarding the partitioning of iodine between liquid and vapor in steam generator secondary. Experimental studies have determined that the partitioning of iodine in water is very sensitive to the pH. Based on this experimental evidence, the NRC requested the INEL to perform an analytical assessment of secondary coolant system (SCS) pH during an SGTR. Design basis thermal and hydraulic calculations were used together with industry standard chemistry guidelines to determine the SCS chemical concentrations during an SGTR. These were used as input to the Facility for Analysis of Chemical Thermodynamics computer system to calculate the equilibrium pH in the SCS at various discrete time during an SGTR. The results of this analysis indicate that the SCS pH decreases from the initial value of 8.8 to approximately 6.5 by the end of the transient, independent of PWR design

Preliminary evaluation of steam generator tube rupture (SGTR) accident in lead cooled reactor

International Nuclear Information System (INIS)

Frano, R. Lo; Forasassi, G.

2009-01-01

In this paper some contributions are provided to the development of a European Lead-cooled System, known as the ELSY project (within EU-6 Framework Project); that will constitute a possible reference system for a large lead-cooled reactor of GEN IV. Steam generator (SG) tubing of this system type might be subject to a variety of degradation processes, such as cracking, wall thinning and potential leakage or rupture, eventually leading to the failure of one or more SG tubes that constitute a steam generator tube rupture (SGTR) accident with possible consequences for the safety of the primary systems. It is therefore of interest for the designer to know how the SG itself, as well as the vessel and internals structures, behave under impulsive loading conditions (in form of a rapid and strong increase of pressure) that can arise as consequences of the interaction between the primary and secondary coolants (lead-water interaction). The analysed initiator event, as already mentioned, is a large break (up to a double ended guillotine break) of one (or more) SG cooling tubes that may become severe enough to determine dangerous effects on the interested structures. In order to better simulate and perform the mentioned postulated SGTR accident sequence analyses, an appropriate numerical model with the available computing resources (FEM codes) was set up at the DIMNP of Pisa University. That model was used to evaluate the effects of the propagation of the blast pressure waves inside the SG structures, taking into account also the sloshing phenomenon that could be induced by the lead primary coolant motions. Therefore the SGTR effects study may be considered as a transient and non linear problem the solution of which provides the 'time histories' of hydrodynamic pressures and stresses on the reactor pressure vessel and internals walls. (author)

Modeling fault rupture hazard for the proposed repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Coppersmith, K.J.; Youngs, R.R.

1992-01-01

In this paper as part of the Electric Power Research Institute's High Level Waste program, the authors have developed a preliminary probabilistic model for assessing the hazard of fault rupture to the proposed high level waste repository at Yucca Mountain. The model is composed of two parts: the earthquake occurrence model that describes the three-dimensional geometry of earthquake sources and the earthquake recurrence characteristics for all sources in the site vicinity; and the rupture model that describes the probability of coseismic fault rupture of various lengths and amounts of displacement within the repository horizon 350 m below the surface. The latter uses empirical data from normal-faulting earthquakes to relate the rupture dimensions and fault displacement amounts to the magnitude of the earthquake. using a simulation procedure, we allow for earthquake occurrence on all of the earthquake sources in the site vicinity, model the location and displacement due to primary faults, and model the occurrence of secondary faulting in conjunction with primary faulting

Analysis of induced steam generator tube rupture using MAAP 4.0

International Nuclear Information System (INIS)

Kenton, M.; Epstein, M.; Henry, R.E.; Paik, C.; Fuller, E.

1996-01-01

The nuclear industry has initiated a program of Steam Generator Degradation Specific Management (SGDSM) to cope with the various types of corrosion that have been observed in pressurized water reactor (PWR) steam generators. In parallel, the U.S. Nuclear Regulatory Commission is promulgating revised rules on steam generator tube integrity. To support these efforts, the Electric Power Research Institute has sponsored calculations with the MAAP 4 code. The principal objective of these calculations is to estimate the peak temperatures experienced by the steam generator tubes during high-pressure severe accidents. These results are used to evaluate the potential for degraded tubes to leak or rupture. Attention was focused on station blackout (SBO) accidents with loss of turbine-driven auxiliary feedwater because these generally result in the greatest threat to the tubes

Application of probabilistic fracture mechanics to estimate the risk of rupture of PWR steam generator tubes

International Nuclear Information System (INIS)

Pitner, P.; Riffard, T.; Granger, B.

1992-01-01

This paper describes the COMPROMIS code developed by Electricite de France (EDF) to optimize the tube bundle maintenance of steam generators. The model, based on probabilistic fracture mechanics, makes it possible to quantify the influence of in-service inspections and maintenance work on the risk of an SG tube rupture, taking all significant parameters into account as random variables (initial defect size distribution, reliability of non-destructive detection and sizing, crack initiation and propagation, critical sizes, leak before risk of break, etc.). (authors). 5 refs., 8 figs., 3 tabs

Code Assessment of SPACE 2.19 using LSTF Steam Generator Tube Rupture Test

Energy Technology Data Exchange (ETDEWEB)

Kim, Minhee; Kim, Seyun [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

The SPACE is a best estimated two-phase three-field thermal-hydraulic analysis code used to analyze the safety and performance of pressurized water reactors. As a result of the development, the 2.19 version of the code was released through the successive various verification and validation works. The present work is on the line of expanding the work by Kim et al. In this study, results produced by the SPACE 2.19 code were compared with the experimental data from JAERI's LSTF Test Run LSTF SB-SG-06 experiment simulating a Steam Generator Tube Rupture (SGTR) transient. In order to identify the predictability of SPACE 2.19, the LSTF steam generator tube rupture test was simulated. To evaluate the computed results, LSTF SB-SG-06 test data simulating the SGTR and the RELAP5/ MOD3.1 are used. The calculation results indicate that the SPACE 2.19 code predicted well the sequence of events and the major phenomena during the transient, such as the asymmetric loop behavior, reactor coolant system cooldown and heat transfer by natural circulation, the primary and secondary system depressurization by the pressurizer auxiliary spray and the steam dump using the intact loop steam generator relief valve.

Modeling 3D Dynamic Rupture on Arbitrarily-Shaped faults by Boundary-Conforming Finite Difference Method

Science.gov (United States)

Zhu, D.; Zhu, H.; Luo, Y.; Chen, X.

2008-12-01

We use a new finite difference method (FDM) and the slip-weakening law to model the rupture dynamics of a non-planar fault embedded in a 3-D elastic media with free surface. The new FDM, based on boundary- conforming grid, sets up the mapping equations between the curvilinear coordinate and the Cartesian coordinate and transforms irregular physical space to regular computational space; it also employs a higher- order non-staggered DRP/opt MacCormack scheme which is of low dispersion and low dissipation so that the high accuracy and stability of our rupture modeling are guaranteed. Compared with the previous methods, not only we can compute the spontaneous rupture of an arbitrarily shaped fault, but also can model the influence of the surface topography on the rupture process of earthquake. In order to verify the feasibility of this method, we compared our results and other previous results, and found out they matched perfectly. Thanks to the boundary-conforming FDM, problems such as dynamic rupture with arbitrary dip, strike and rake over an arbitrary curved plane can be handled; and supershear or subshear rupture can be simulated with different parameters such as the initial stresses and the critical slip displacement Dc. Besides, our rupture modeling is economical to be implemented owing to its high efficiency and does not suffer from displacement leakage. With the help of inversion data of rupture by field observations, this method is convenient to model rupture processes and seismograms of natural earthquakes.

Hybrid broadband Ground Motion simulation based on a dynamic rupture model of the 2011 Mw 9.0 Tohoku earthquake.

Science.gov (United States)

Galvez, P.; Somerville, P.; Bayless, J.; Dalguer, L. A.

2015-12-01

The rupture process of the 2011 Tohoku earthquake exhibits depth-dependent variations in the frequency content of seismic radiation from the plate interface. This depth-varying rupture property has also been observed in other subduction zones (Lay et al, 2012). During the Tohoku earthquake, the shallow region radiated coherent low frequency seismic waves whereas the deeper region radiated high frequency waves. Several kinematic inversions (Suzuki et al, 2011; Lee et al, 2011; Bletery et al, 2014; Minson et al, 2014) detected seismic waves below 0.1 Hz coming from the shallow depths that produced slip larger than 40-50 meters close to the trench. Using empirical green functions, Asano & Iwata (2012), Kurahashi and Irikura (2011) and others detected regions of strong ground motion radiation at frequencies up to 10Hz located mainly at the bottom of the plate interface. A recent dynamic model that embodies this depth-dependent radiation using physical models has been developed by Galvez et al (2014, 2015). In this model the rupture process is modeled using a linear weakening friction law with slip reactivation on the shallow region of the plate interface (Galvez et al, 2015). This model reproduces the multiple seismic wave fronts recorded on the Kik-net seismic network along the Japanese coast up to 0.1 Hz as well as the GPS displacements. In the deep region, the rupture sequence is consistent with the sequence of the strong ground motion generation areas (SMGAs) that radiate high frequency ground motion at the bottom of the plate interface (Kurahashi and Irikura, 2013). It remains challenging to perform ground motions fully coupled with a dynamic rupture up to 10 Hz for a megathrust event. Therefore, to generate high frequency ground motions, we make use of the stochastic approach of Graves and Pitarka (2010) but add to the source spectrum the slip rate function of the dynamic model. In this hybrid-dynamic approach, the slip rate function is windowed with Gaussian

Dynamic rupture models of earthquakes on the Bartlett Springs Fault, Northern California

Science.gov (United States)

Lozos, Julian C.; Harris, Ruth A.; Murray, Jessica R.; Lienkaemper, James J.

2015-01-01

The Bartlett Springs Fault (BSF), the easternmost branch of the northern San Andreas Fault system, creeps along much of its length. Geodetic data for the BSF are sparse, and surface creep rates are generally poorly constrained. The two existing geodetic slip rate inversions resolve at least one locked patch within the creeping zones. We use the 3-D finite element code FaultMod to conduct dynamic rupture models based on both geodetic inversions, in order to determine the ability of rupture to propagate into the creeping regions, as well as to assess possible magnitudes for BSF ruptures. For both sets of models, we find that the distribution of aseismic creep limits the extent of coseismic rupture, due to the contrast in frictional properties between the locked and creeping regions.

Predicting creep rupture from early strain data

International Nuclear Information System (INIS)

Holmstroem, Stefan; Auerkari, Pertti

2009-01-01

To extend creep life modelling from classical rupture modelling, a robust and effective parametric strain model has been developed. The model can reproduce with good accuracy all parts of the creep curve, economically utilising the available rupture models. The resulting combined model can also be used to predict rupture from the available strain data, and to further improve the rupture models. The methodology can utilise unfailed specimen data for life assessment at lower stress levels than what is possible from rupture data alone. Master curves for creep strain and rupture have been produced for oxygen-free phosphorus-doped (OFP) copper with a maximum testing time of 51,000 h. Values of time to specific strain at given stress (40-165 MPa) and temperature (125-350 deg. C) were fitted to the models in the strain range of 0.1-38%. With typical inhomogeneous multi-batch creep data, the combined strain and rupture modelling involves the steps of investigation of the data quality, extraction of elastic and creep strain response, rupture modelling, data set balancing and creep strain modelling. Finally, the master curves for strain and rupture are tested and validated for overall fitting efficiency. With the Wilshire equation as the basis for the rupture model, the strain model applies classical parametric principles with an Arrhenius type of thermal activation and a power law type of stress dependence for the strain rate. The strain model also assumes that the processes of primary and secondary creep can be reasonably correlated. The rupture model represents a clear improvement over previous models in the range of the test data. The creep strain information from interrupted and running tests were assessed together with the rupture data investigating the possibility of rupture model improvement towards lower stress levels by inverse utilisation of the combined rupture based strain model. The developed creep strain model together with the improved rupture model is

Steam-generator-tube-rupture transients for pressurized-water reactors

International Nuclear Information System (INIS)

Dobranich, D.; Henninger, R.J.; DeMuth, N.S.

1982-01-01

Steam generator tube ruptures with and without concurrent main-steam-line break are investigated for pressurized water reactors supplied by the major US vendors. The goal of these analyses is to provide thermodynamic and flow conditions for the determination of iodine transport to the environment and to provide an evaluation of the adequacy of the plant safety systems and operating procedures for controlling these transients. The automatic safety systems of the plant were found to be adequate for the mitigation of these transients. Emergency injection system flows equilibrated with the leakage flows and prevented core uncovery. Sufficient time was afforded by the plant safety systems for the operators to identify the problem and to take appropriate measures

Risk assessment of severe accident-induced steam generator tube rupture

International Nuclear Information System (INIS)

1998-03-01

This report describes the basis, results, and related risk implications of an analysis performed by an ad hoc working group of the U.S. Nuclear Regulatory Commission (NRC) to assess the containment bypass potential attributable to steam generator tube rupture (SGTR) induced by severe accident conditions. The SGTR Severe Accident Working Group, comprised of staff members from the NRC's Offices of Nuclear Reactor Regulation (NRR) and Nuclear Regulatory Research (RES), undertook the analysis beginning in December 1995 to support a proposed steam generator integrity rule. The work drew upon previous risk and thermal-hydraulic analyses of core damage sequences, with a focus on the Surry plant as a representative example. This analysis yielded new results, however, derived by predicting thermal-hydraulic conditions of selected severe accident scenarios using the SCDAP/RELAP5 computer code, flawed tube failure modeling, and tube failure probability estimates. These results, in terms of containment bypass probability, form the basis for the findings presented in this report. The representative calculation using Surry plant data indicates that some existing plants could be vulnerable to containment bypass resulting from tube failure during severe accidents. To specifically identify the population of plants that may pose a significant bypass risk would require more definitive analysis considering uncertainties in some assumptions and plant- and design-specific variables. 46 refs., 62 figs., 37 tabs

Microvessel rupture induced by high-intensity therapeutic ultrasound-a study of parameter sensitivity in a simple in vivo model.

Science.gov (United States)

Kim, Yeonho; Nabili, Marjan; Acharya, Priyanka; Lopez, Asis; Myers, Matthew R

2017-01-01

Safety analyses of transcranial therapeutic ultrasound procedures require knowledge of the dependence of the rupture probability and rupture time upon sonication parameters. As previous vessel-rupture studies have concentrated on a specific set of exposure conditions, there is a need for more comprehensive parametric studies. Probability of rupture and rupture times were measured by exposing the large blood vessel of a live earthworm to high-intensity focused ultrasound pulse trains of various characteristics. Pressures generated by the ultrasound transducers were estimated through numerical solutions to the KZK (Khokhlov-Zabolotskaya-Kuznetsov) equation. Three ultrasound frequencies (1.1, 2.5, and 3.3 MHz) were considered, as were three pulse repetition frequencies (1, 3, and 10 Hz), and two duty factors (0.0001, 0.001). The pressures produced ranged from 4 to 18 MPa. Exposures of up to 10 min in duration were employed. Trials were repeated an average of 11 times. No trends as a function of pulse repetition rate were identifiable, for either probability of rupture or rupture time. Rupture time was found to be a strong function of duty factor at the lower pressures; at 1.1 MHz the rupture time was an order of magnitude lower for the 0.001 duty factor than the 0.0001. At moderate pressures, the difference between the duty factors was less, and there was essentially no difference between duty factors at the highest pressure. Probability of rupture was not found to be a strong function of duty factor. Rupture thresholds were about 4 MPa for the 1.1 MHz frequency, 7 MPa at 3.3 MHz, and 11 MPa for the 2.5 MHz, though the pressure value at 2.5 MHz frequency will likely be reduced when steep-angle corrections are accounted for in the KZK model used to estimate pressures. Mechanical index provided a better collapse of the data (less separation of the curves pertaining to the different frequencies) than peak negative pressure, for both probability of rupture and

Retrieving rupture history using waveform inversions in time sequence

Science.gov (United States)

Yi, L.; Xu, C.; Zhang, X.

2017-12-01

The rupture history of large earthquakes is generally regenerated using the waveform inversion through utilizing seismological waveform records. In the waveform inversion, based on the superposition principle, the rupture process is linearly parameterized. After discretizing the fault plane into sub-faults, the local source time function of each sub-fault is usually parameterized using the multi-time window method, e.g., mutual overlapped triangular functions. Then the forward waveform of each sub-fault is synthesized through convoluting the source time function with its Green function. According to the superposition principle, these forward waveforms generated from the fault plane are summarized in the recorded waveforms after aligning the arrival times. Then the slip history is retrieved using the waveform inversion method after the superposing of all forward waveforms for each correspond seismological waveform records. Apart from the isolation of these forward waveforms generated from each sub-fault, we also realize that these waveforms are gradually and sequentially superimposed in the recorded waveforms. Thus we proposed a idea that the rupture model is possibly detachable in sequent rupture times. According to the constrained waveform length method emphasized in our previous work, the length of inverted waveforms used in the waveform inversion is objectively constrained by the rupture velocity and rise time. And one essential prior condition is the predetermined fault plane that limits the duration of rupture time, which means the waveform inversion is restricted in a pre-set rupture duration time. Therefore, we proposed a strategy to inverse the rupture process sequentially using the progressively shift rupture times as the rupture front expanding in the fault plane. And we have designed a simulation inversion to test the feasibility of the method. Our test result shows the prospect of this idea that requiring furthermore investigation.

A minimal rupture cascade model for living cell plasticity

Science.gov (United States)

Polizzi, Stefano; Laperrousaz, Bastien; Perez-Reche, Francisco J.; Nicolini, Franck E.; Maguer Satta, Véronique; Arneodo, Alain; Argoul, Françoise

2018-05-01

Under physiological and pathological conditions, cells experience large forces and deformations that often exceed the linear viscoelastic regime. Here we drive CD34+ cells isolated from healthy and leukemic bone marrows in the highly nonlinear elasto-plastic regime, by poking their perinuclear region with a sharp AFM cantilever tip. We use the wavelet transform mathematical microscope to identify singular events in the force-indentation curves induced by local rupture events in the cytoskeleton (CSK). We distinguish two types of rupture events, brittle failures likely corresponding to irreversible ruptures in a stiff and highly cross-linked CSK and ductile failures resulting from dynamic cross-linker unbindings during plastic deformation without loss of CSK integrity. We propose a stochastic multiplicative cascade model of mechanical ruptures that reproduces quantitatively the experimental distributions of the energy released during these events, and provides some mathematical and mechanistic understanding of the robustness of the log-normal statistics observed in both brittle and ductile situations. We also show that brittle failures are relatively more prominent in leukemia than in healthy cells suggesting their greater fragility.

Identification of earthquakes that generate tsunamis in Java and Nusa Tenggara using rupture duration analysis

Energy Technology Data Exchange (ETDEWEB)

Pribadi, S., E-mail: sugengpribadimsc@gmail.com [Tsunami Warning Information Division, Indonesian Meteorological Climatological and Geophysical Agency (BMKG), Jalan Angkasa I No. 2, Jakarta13920 and Graduate Student of Earth Sciences, Faculty of Earth Sciences and Technology, Bandung Institute of T (Indonesia); Puspito, N. T.; Yudistira, T.; Afnimar,; Ibrahim, G. [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Bandung Institute of Technology (ITB), Jalan Ganesha 10, Bandung 40132 (Indonesia); Laksono, B. I. [Database Maintenance Division, Indonesian Meteorological Climatological and Geophysical Agency (BMKG), Jalan Angkasa I No.2, Jakarta 13920 (Indonesia); Adnan, Z. [Database Maintenance Division, Indonesian Meteorological Climatological and Geophysical Agency (BMKG), Jalan Angkasa I No. 2, Jakarta 13920 and Graduate Student of Earth Sciences, Faculty of Earth Sciences and Technology, Bandung Institute of Technol (Indonesia)

2014-09-25

Java and Nusa Tenggara are the tectonically active of Sunda arc. This study discuss the rupture duration as a manifestation of the power of earthquake-generated tsunami. We use the teleseismic (30° - 90°) body waves with high-frequency energy Seismometer is from IRIS network as amount 206 broadband units. We applied the Butterworth high bandpass (1 - 2 Hz) filtered. The arrival and travel times started from wave phase of P - PP which based on Jeffrey Bullens table with TauP program. The results are that the June 2, 1994 Banyuwangi and the July 17, 2006 Pangandaran earthquakes identified as tsunami earthquakes with long rupture duration (To > 100 second), medium magnitude (7.6 < Mw < 7.9) and located near the trench. The others are 4 tsunamigenic earthquakes and 3 inland earthquakes with short rupture duration start from To > 50 second which depend on its magnitude. Those events are located far from the trench.

The Inclusion of Arbitrary Load Histories in the Strength Decay Model for Stress Rupture

Science.gov (United States)

Reeder, James R.

2014-01-01

Stress rupture is a failure mechanism where failures can occur after a period of time, even though the material has seen no increase in load. Carbon/epoxy composite materials have demonstrated the stress rupture failure mechanism. In a previous work, a model was proposed for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures based on strength degradation. However, the original model was limited to constant load periods (holds) at constant load. The model was expanded in this paper to address arbitrary loading histories and specifically the inclusions of ramp loadings up to holds and back down. The broadening of the model allows for failures on loading to be treated as any other failure that may occur during testing instead of having to be treated as a special case. The inclusion of ramps can also influence the length of the "safe period" following proof loading that was previously predicted by the model. No stress rupture failures are predicted in a safe period because time is required for strength to decay from above the proof level to the lower level of loading. Although the model can predict failures during the ramp periods, no closed-form solution for the failure times could be derived. Therefore, two suggested solution techniques were proposed. Finally, the model was used to design an experiment that could detect the difference between the strength decay model and a commonly used model for stress rupture. Although these types of models are necessary to help guide experiments for stress rupture, only experimental evidence will determine how well the model may predict actual material response. If the model can be shown to be accurate, current proof loading requirements may result in predicted safe periods as long as 10(13) years. COPVs design requirements for stress rupture may then be relaxed, allowing more efficient designs, while still maintaining an acceptable level of safety.

Globe Rupture

Directory of Open Access Journals (Sweden)

Reid Honda

2017-07-01

Full Text Available History of present illness: A 46-year-old male presented to the emergency department (ED with severe left eye pain and decreased vision after tripping and striking the left side of his head on the corner of his wooden nightstand. The patient arrived as an inter-facility transfer for a suspected globe rupture with a protective eye covering in place; thus, further physical examination of the eye was not performed by the emergency physician in order to avoid further leakage of aqueous humor. Significant findings: The patient’s computed tomography (CT head demonstrated a deformed left globe, concerning for ruptured globe. The patient had hyperdense material in the posterior segment (see green arrow, consistent with vitreous hemorrhage. CT findings that are consistent with globe rupture may include a collapsed globe, intraocular air, or foreign bodies. Discussion: A globe rupture is a full-thickness defect in the cornea, sclera, or both.1 It is an ophthalmologic emergency. Globe ruptures are almost always secondary to direct perforation via a penetrating mechanism; however, it can occur due to blunt injury if the force generated creates sufficient intraocular pressure to tear the sclera.2 Globes most commonly rupture at the insertions of the intraocular muscles or at the limbus. They are associated with a high rate of concomitant orbital floor fractures.2,3 Possible physical examination findings include a shallow anterior chamber on slit-lamp exam, hyphema, and an irregular “teardrop” pupil. Additionally, a positive Seidel sign, which is performed by instilling fluorescein in the eye and then examining for a dark stream of aqueous humor, is indicative of a globe rupture.4 CT is often used to assess for globe rupture; finds of a foreign body, intraocular air, abnormal contour or volume of the globe, or disruption of the sclera suggest globe rupture.2 The sensitivity of CT scan for diagnosis of globe rupture is only 75%; thus, high clinical

Rupture Dynamics and Scaling Behavior of Hydraulically Stimulated Micro-Earthquakes in a Shale Reservoir

Science.gov (United States)

Viegas, G. F.; Urbancic, T.; Baig, A. M.

2014-12-01

In hydraulic fracturing completion programs fluids are injected under pressure into fractured rock formations to open escape pathways for trapped hydrocarbons along pre-existing and newly generated fractures. To characterize the failure process, we estimate static and dynamic source and rupture parameters, such as dynamic and static stress drop, radiated energy, seismic efficiency, failure modes, failure plane orientations and dimensions, and rupture velocity to investigate the rupture dynamics and scaling relations of micro-earthquakes induced during a hydraulic fracturing shale completion program in NE British Columbia, Canada. The relationships between the different parameters combined with the in-situ stress field and rock properties provide valuable information on the rupture process giving insights into the generation and development of the fracture network. Approximately 30,000 micro-earthquakes were recorded using three multi-sensor arrays of high frequency geophones temporarily placed close to the treatment area at reservoir depth (~2km). On average the events have low radiated energy, low dynamic stress and low seismic efficiency, consistent with the obtained slow rupture velocities. Events fail in overshoot mode (slip weakening failure model), with fluids lubricating faults and decreasing friction resistance. Events occurring in deeper formations tend to have faster rupture velocities and are more efficient in radiating energy. Variations in rupture velocity tend to correlate with variation in depth, fault azimuth and elapsed time, reflecting a dominance of the local stress field over other factors. Several regions with different characteristic failure modes are identifiable based on coherent stress drop, seismic efficiency, rupture velocities and fracture orientations. Variations of source parameters with rock rheology and hydro-fracture fluids are also observed. Our results suggest that the spatial and temporal distribution of events with similar

Earthquake cycle modeling of multi-segmented faults: dynamic rupture and ground motion simulation of the 1992 Mw 7.3 Landers earthquake.

Science.gov (United States)

Petukhin, A.; Galvez, P.; Somerville, P.; Ampuero, J. P.

2017-12-01

We perform earthquake cycle simulations to study the characteristics of source scaling relations and strong ground motions and in multi-segmented fault ruptures. For earthquake cycle modeling, a quasi-dynamic solver (QDYN, Luo et al, 2016) is used to nucleate events and the fully dynamic solver (SPECFEM3D, Galvez et al., 2014, 2016) is used to simulate earthquake ruptures. The Mw 7.3 Landers earthquake has been chosen as a target earthquake to validate our methodology. The SCEC fault geometry for the three-segmented Landers rupture is included and extended at both ends to a total length of 200 km. We followed the 2-D spatial correlated Dc distributions based on Hillers et. al. (2007) that associates Dc distribution with different degrees of fault maturity. The fault maturity is related to the variability of Dc on a microscopic scale. Large variations of Dc represents immature faults and lower variations of Dc represents mature faults. Moreover we impose a taper (a-b) at the fault edges and limit the fault depth to 15 km. Using these settings, earthquake cycle simulations are performed to nucleate seismic events on different sections of the fault, and dynamic rupture modeling is used to propagate the ruptures. The fault segmentation brings complexity into the rupture process. For instance, the change of strike between fault segments enhances strong variations of stress. In fact, Oglesby and Mai (2012) show the normal stress varies from positive (clamping) to negative (unclamping) between fault segments, which leads to favorable or unfavorable conditions for rupture growth. To replicate these complexities and the effect of fault segmentation in the rupture process, we perform earthquake cycles with dynamic rupture modeling and generate events similar to the Mw 7.3 Landers earthquake. We extract the asperities of these events and analyze the scaling relations between rupture area, average slip and combined area of asperities versus moment magnitude. Finally, the

Experiment data report for Semiscale Mod-1 test S-28-3 (steam generator tube rupture test)

International Nuclear Information System (INIS)

Gillins, R.L.; Sackett, K.E.

1977-10-01

Recorded test data are presented for Test S-28-3 of the Semiscale Mod-1 steam generator tube rupture test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-28-3 was conducted from initial conditions of 15621 kPa and 555 K to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the broken loop cold leg piping. During the test, cooling water was injected into the cold leg of the intact and broken loops to simulate emergency core coolant injection in a PWR. Twelve steam generator tube ruptures were simulated by a controlled injection from a heated accumulator into the intact loop hot leg

Experiment data report for semiscale Mod-1 test S-28-2 (steam generator tube rupture test)

International Nuclear Information System (INIS)

Patton, M.L.; Sackett, K.E.

1977-10-01

Recorded test data are presented for Test S-28-2 of the Semiscale Mod-1 steam generator tube rupture test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-28-2 was conducted from initial conditions of 15 936 kPa and 558 K to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the broken loop cold leg piping. During the test, cooling water was injected into the cold leg of the intact and broken loops to simulate emergency core coolant injection in a PWR. For Test S-28-2, accumulator injection into the intact loop hot leg was provided to simulate simulate the rupture of six steam generator tubes

Experiment data report for semiscale Mod-1 test S-28-4 (steam generator tube rupture test)

International Nuclear Information System (INIS)

Esparza, V.; Sackett, K.E.

1977-10-01

Recorded test data are presented for Test S-28-4 of the Semiscale Mod-1 steam generator tube rupture test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-28-4 was conducted from initial conditions of 15 646 kPa and 557 K to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the broken loop cold leg piping. During the test, cooling water was injected into the cold leg of the intact and broken loops to simulate emergency core coolant injection in a PWR. Thirty steam generator tube ruptures were simulated by a controlled injection from a heated accumulator into the intact loop hot leg

Five Tubes Rupture at Cold Side of Steam Generator Simulation Test Report Using the ATLAS

International Nuclear Information System (INIS)

Kang, Kyoung Ho; Park, Hyun Sik; Cho, Seok

2010-12-01

In this study, a postulated SGTR event of the APR1400 was experimentally investigated with the ATLAS. In order to simulate a double-ended rupture of five U-tubes in the APR1400, the SGTR-CL-02 test was performed with the ATLAS. The main objectives of this test were not only to provide a physical insight into the system response of the APR1400 during the SGTR but also to produce integral effect experimental data to validate the safety analysis code. In the present report, major thermal-hydraulic phenomena such as the system pressures, the collapsed water levels, and the break flow rate were presented and discussed. Compared to the case of a single U-tube rupture test, opening frequency of the MSSVs in the intact steam generator (SG-2) was highly reduced after 500 seconds in the present SGTR-CL-02 test. Large discharge of the primary inventory resulted in rapid depressurization of the primary system and consequently early injection of the SIP. Supply of cold ECC water by the SIPs reduced the energy transfer to the secondary side compared with the single U-tube rupture case. Less heat transfer to the secondary side had more influence on the secondary pressure of the affected steam generator than the break flow. This integral effect test data will be used to evaluate the prediction capability of existing safety analysis codes of the MARS and the RELAP5 as well as the SPACE code

Five Tubes Rupture at Hot Side of Steam Generator Simulation Test Report Using the ATLAS

International Nuclear Information System (INIS)

Kang, Kyoung Ho; Park, Hyun Sik; Cho Seok

2010-12-01

In this study, a postulated SGTR event of the APR1400 was experimentally investigated with the ATLAS. In order to simulate a double-ended rupture of five U-tubes in the APR1400, the SGTR-HL-05 test was performed with the ATLAS. The main objectives of this test were not only to provide a physical insight into the system response of the APR1400 during the SGTR but also to produce integral effect experimental data to validate the SPACE code. In the present report, major thermal-hydraulic phenomena such as the system pressures, the collapsed water levels, and the break flow rate were presented and discussed. On the contrary to the case of a single U-tube rupture test, the MSSV of the intact steam generator was not opened any more after 1500 seconds in the present SGTR-HL-05 test. Large discharge of the primary inventory resulted in rapid depressurization of the primary system and consequently early injection of the SIP. Supply of cold ECC water by the SIPs reduced the energy transfer to the secondary side compared with the single U-tube rupture case. Less heat transfer to the secondary side had more influence on the secondary pressure of the affected steam generator than the break flow. This integral effect test data will be used to evaluate the prediction capability of existing safety analysis codes of the MARS and the RELAP5 as well as the SPACE code

Development of a computer model to predict aortic rupture due to impact loading.

Science.gov (United States)

Shah, C S; Yang, K H; Hardy, W; Wang, H K; King, A I

2001-11-01

Aortic injuries during blunt thoracic impacts can lead to life threatening hemorrhagic shock and potential exsanguination. Experimental approaches designed to study the mechanism of aortic rupture such as the testing of cadavers is not only expensive and time consuming, but has also been relatively unsuccessful. The objective of this study was to develop a computer model and to use it to predict modes of loading that are most likely to produce aortic ruptures. Previously, a 3D finite element model of the human thorax was developed and validated against data obtained from lateral pendulum tests. The model included a detailed description of the heart, lungs, rib cage, sternum, spine, diaphragm, major blood vessels and intercostal muscles. However, the aorta was modeled as a hollow tube using shell elements with no fluid within, and its material properties were assumed to be linear and isotropic. In this study fluid elements representing blood have been incorporated into the model in order to simulate pressure changes inside the aorta due to impact. The current model was globally validated against experimental data published in the literature for both frontal and lateral pendulum impact tests. Simulations of the validated model for thoracic impacts from a number of directions indicate that the ligamentum arteriosum, subclavian artery, parietal pleura and pressure changes within the aorta are factors that could influence aortic rupture. The model suggests that a right-sided impact to the chest is potentially more hazardous with respect to aortic rupture than any other impact direction simulated in this study. The aortic isthmus was the most likely site of aortic rupture regardless of impact direction. The reader is cautioned that this model could only be validated on a global scale. Validation of the kinematics and dynamics of the aorta at the local level could not be done due to a lack of experimental data. It is hoped that this model will be used to design

Real-Time Detection of Rupture Development: Earthquake Early Warning Using P Waves From Growing Ruptures

Science.gov (United States)

Kodera, Yuki

2018-01-01

Large earthquakes with long rupture durations emit P wave energy throughout the rupture period. Incorporating late-onset P waves into earthquake early warning (EEW) algorithms could contribute to robust predictions of strong ground motion. Here I describe a technique to detect in real time P waves from growing ruptures to improve the timeliness of an EEW algorithm based on seismic wavefield estimation. The proposed P wave detector, which employs a simple polarization analysis, successfully detected P waves from strong motion generation areas of the 2011 Mw 9.0 Tohoku-oki earthquake rupture. An analysis using 23 large (M ≥ 7) events from Japan confirmed that seismic intensity predictions based on the P wave detector significantly increased lead times without appreciably decreasing the prediction accuracy. P waves from growing ruptures, being one of the fastest carriers of information on ongoing rupture development, have the potential to improve the performance of EEW systems.

Diagnosis of Complex Pulley Ruptures Using Ultrasound in Cadaver Models.

Science.gov (United States)

Schöffl, Isabelle; Hugel, Arnica; Schöffl, Volker; Rascher, Wolfgang; Jüngert, Jörg

2017-03-01

Pulley ruptures are common in climbing athletes. The purposes of this study were to determine the specific positioning of each pulley with regards to the joint, and to evaluate the ultrasound diagnostics of various pulley rupture combinations. For this, 34 cadaver fingers were analyzed via ultrasound, the results of which were compared to anatomic measurements. Different pulley ruptures were then simulated and evaluated using ultrasound in standardized dynamic forced flexion. Visualization of the A2 and A4 pulleys was achieved 100% of the time, while the A3 pulley was visible in 74% of cases. Similarly, injuries to the A2 and A4 pulleys were readily observable, while A3 pulley injuries were more challenging to identify (sensitivity of 0.2 for singular A3 pulley, 0.5 for A2/A4 pulley and 0.33 for A3/A4 pulley ruptures). Receiver operating characteristic analysis was used to evaluate the optimal tendon-bone distance for pulley rupture diagnosis, a threshold which was determined to be 1.9 mm for A2 pulley ruptures and 1.85 for A4 pulley ruptures. This study was the first to carry out a cadaver ultrasound examination of a wide variety of pulley ruptures. Ultrasound is a highly accurate tool for visualizing the A2 and A4 pulleys in a cadaver model. This method of pathology diagnosis was determined to be suitable for injuries to the A2 and A4 pulleys, but inadequate for A3 pulley injuries. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

A support-operator method for 3-D rupture dynamics

Science.gov (United States)

Ely, Geoffrey P.; Day, Steven M.; Minster, Jean-Bernard

2009-06-01

We present a numerical method to simulate spontaneous shear crack propagation within a heterogeneous, 3-D, viscoelastic medium. Wave motions are computed on a logically rectangular hexahedral mesh, using the generalized finite-difference method of Support Operators (SOM). This approach enables modelling of non-planar surfaces and non-planar fault ruptures. Our implementation, the Support Operator Rupture Dynamics (SORD) code, is highly scalable, enabling large-scale, multiprocessors calculations. The fault surface is modelled by coupled double nodes, where rupture occurs as dictated by the local stress conditions and a frictional failure law. The method successfully performs test problems developed for the Southern California Earthquake Center (SCEC)/U.S. Geological Survey (USGS) dynamic earthquake rupture code validation exercise, showing good agreement with semi-analytical boundary integral method results. We undertake further dynamic rupture tests to quantify numerical errors introduced by shear deformations to the hexahedral mesh. We generate a family of meshes distorted by simple shearing, in the along-strike direction, up to a maximum of 73°. For SCEC/USGS validation problem number 3, grid-induced errors increase with mesh shear angle, with the logarithm of error approximately proportional to angle over the range tested. At 73°, rms misfits are about 10 per cent for peak slip rate, and 0.5 per cent for both rupture time and total slip, indicating that the method (which, up to now, we have applied mainly to near-vertical strike-slip faulting) is also capable of handling geometries appropriate to low-angle surface-rupturing thrust earthquakes. Additionally, we demonstrate non-planar rupture effects, by modifying the test geometry to include, respectively, cylindrical curvature and sharp kinks.

Development of rupture discs for the FBTR

International Nuclear Information System (INIS)

Chetal, S.C.; Raju, C.; Anandkumar, V.; Seetharaman, V.; Rajan, K.K.

1984-01-01

Rupture discs are required as a safety device for protecting the secondary sodium circuit and its components against high pressure surges due to accidental water steam leaks in sodium heated steam generator and the consequent sodium water reaction. For identical reasons, rupture discs are also required on the vessels used for decontamination of sodium components. Reverse buckling knife blade concept with austenitic stainless steel disc has been developed for the rupture disc assemblies required for Fast Breeder Test Reactor (FBTR). Hydroforming process without any die has been used for disc fabrication. One rupture disc assembly required for steam generator is undergoing sodium endurance test and has accumulated 4,500 hours. The present status of development work as demonstrated by room temperature experimental results as well as the scope for future work are discussed. (author)

Mathematical modeling and numerical simulation of unilateral dynamic rupture propagation along very-long reverse faults

Science.gov (United States)

Hirano, S.

2017-12-01

For some great earthquakes, dynamic rupture propagates unilaterally along a horizontal direction of very-long reverse faults (e.g., the Mw9.1 Sumatra earthquake in 2004, the Mw8.0 Wenchuan earthquake in 2008, and the Mw8.8 Maule earthquake in 2010, etc.). It seems that barriers or creeping sections may not lay along the opposite region of the co-seismically ruptured direction. In fact, in the case of Sumatra, the Mw8.6 earthquake occurred in the opposite region only three months after the mainshock. Mechanism of unilateral mode-II rupture along a material interface has been investigated theoretically and numerically. For mode-II rupture propagating along a material interface, an analytical solution implies that co-seismic stress perturbation depends on the rupture direction (Weertman, 1980 JGR; Hirano & Yamashita, 2016 BSSA), and numerical modeling of plastic yielding contributes to simulating the unilateral rupture (DeDonteny et al., 2011 JGR). However, mode-III rupture may dominate for the very-long reverse faults, and it can be shown that stress perturbation due to mode-III rupture does not depend on the rupture direction. Hence, an effect of the material interface is insufficient to understand the mechanism of unilateral rupture along the very-long reverse faults. In this study, I consider a two-dimensional bimaterial system with interfacial dynamic mode-III rupture under an obliquely pre-stressed configuration (i.e., the maximum shear direction of the background stress is inclined from the interfacial fault). First, I derived an analytical solution of regularized elastic stress field around a steady-state interfacial slip pulse using the method of Rice et al. (2005 BSSA). Then I found that the total stress, which is the sum of the background stress and co-seismic stress perturbation, depends on the rupture direction even in the mode-III case. Second, I executed a finite difference numerical simulation with a plastic yielding model of Andrews (1978 JGR; 2005

Quantifying variability in earthquake rupture models using multidimensional scaling: application to the 2011 Tohoku earthquake

KAUST Repository

Razafindrakoto, Hoby

2015-04-22

Finite-fault earthquake source inversion is an ill-posed inverse problem leading to non-unique solutions. In addition, various fault parametrizations and input data may have been used by different researchers for the same earthquake. Such variability leads to large intra-event variability in the inferred rupture models. One way to understand this problem is to develop robust metrics to quantify model variability. We propose a Multi Dimensional Scaling (MDS) approach to compare rupture models quantitatively. We consider normalized squared and grey-scale metrics that reflect the variability in the location, intensity and geometry of the source parameters. We test the approach on two-dimensional random fields generated using a von Kármán autocorrelation function and varying its spectral parameters. The spread of points in the MDS solution indicates different levels of model variability. We observe that the normalized squared metric is insensitive to variability of spectral parameters, whereas the grey-scale metric is sensitive to small-scale changes in geometry. From this benchmark, we formulate a similarity scale to rank the rupture models. As case studies, we examine inverted models from the Source Inversion Validation (SIV) exercise and published models of the 2011 Mw 9.0 Tohoku earthquake, allowing us to test our approach for a case with a known reference model and one with an unknown true solution. The normalized squared and grey-scale metrics are respectively sensitive to the overall intensity and the extension of the three classes of slip (very large, large, and low). Additionally, we observe that a three-dimensional MDS configuration is preferable for models with large variability. We also find that the models for the Tohoku earthquake derived from tsunami data and their corresponding predictions cluster with a systematic deviation from other models. We demonstrate the stability of the MDS point-cloud using a number of realizations and jackknife tests, for

Quantifying variability in earthquake rupture models using multidimensional scaling: application to the 2011 Tohoku earthquake

KAUST Repository

Razafindrakoto, Hoby; Mai, Paul Martin; Genton, Marc G.; Zhang, Ling; Thingbaijam, Kiran Kumar

2015-01-01

Finite-fault earthquake source inversion is an ill-posed inverse problem leading to non-unique solutions. In addition, various fault parametrizations and input data may have been used by different researchers for the same earthquake. Such variability leads to large intra-event variability in the inferred rupture models. One way to understand this problem is to develop robust metrics to quantify model variability. We propose a Multi Dimensional Scaling (MDS) approach to compare rupture models quantitatively. We consider normalized squared and grey-scale metrics that reflect the variability in the location, intensity and geometry of the source parameters. We test the approach on two-dimensional random fields generated using a von Kármán autocorrelation function and varying its spectral parameters. The spread of points in the MDS solution indicates different levels of model variability. We observe that the normalized squared metric is insensitive to variability of spectral parameters, whereas the grey-scale metric is sensitive to small-scale changes in geometry. From this benchmark, we formulate a similarity scale to rank the rupture models. As case studies, we examine inverted models from the Source Inversion Validation (SIV) exercise and published models of the 2011 Mw 9.0 Tohoku earthquake, allowing us to test our approach for a case with a known reference model and one with an unknown true solution. The normalized squared and grey-scale metrics are respectively sensitive to the overall intensity and the extension of the three classes of slip (very large, large, and low). Additionally, we observe that a three-dimensional MDS configuration is preferable for models with large variability. We also find that the models for the Tohoku earthquake derived from tsunami data and their corresponding predictions cluster with a systematic deviation from other models. We demonstrate the stability of the MDS point-cloud using a number of realizations and jackknife tests, for

Identification of earthquakes that generate tsunamis in Java and Nusa Tenggara using rupture duration analysis

International Nuclear Information System (INIS)

Pribadi, S.; Puspito, N. T.; Yudistira, T.; Afnimar,; Ibrahim, G.; Laksono, B. I.; Adnan, Z.

2014-01-01

Java and Nusa Tenggara are the tectonically active of Sunda arc. This study discuss the rupture duration as a manifestation of the power of earthquake-generated tsunami. We use the teleseismic (30° - 90°) body waves with high-frequency energy Seismometer is from IRIS network as amount 206 broadband units. We applied the Butterworth high bandpass (1 - 2 Hz) filtered. The arrival and travel times started from wave phase of P - PP which based on Jeffrey Bullens table with TauP program. The results are that the June 2, 1994 Banyuwangi and the July 17, 2006 Pangandaran earthquakes identified as tsunami earthquakes with long rupture duration (To > 100 second), medium magnitude (7.6 50 second which depend on its magnitude. Those events are located far from the trench

Experiment data report for Semiscale Mod-1 Test S-28-1 (steam generator tube rupture test series)

International Nuclear Information System (INIS)

Collins, B.L.; Coppin, C.E.; Sackett, K.E.

1977-10-01

Recorded test data are presented for Test S-28-1 of the Semiscale Mod-1 steam generator tube rupture test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-28-1 was conducted from initial conditions of 15 767 kPa and 557 K to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the broken loop cold leg piping. During the test, cooling water was injected into the cold leg of the intact and broken loops to simulate emergency core coolant injection in a PWR. Sixty steam generator tube ruptures were simulated by a controlled injection from a heated accumulator into the intact loop hot leg

Simulation of the behaviour of a servo actuated check valve upon rupture of the feedwater pipe

International Nuclear Information System (INIS)

Lucas, A.M. de; Perezagua, R.L.; Rosa, B. de la; Sanz, J.

1995-01-01

The steam generator replacement programme at Almaraz NPP, provides for the installation of a replacement damped non-return valve for the feedwater system. the function of this valve is to protect the steam generator in the event of a rupture in the feedwater pipe. Sudden closure of the check valve, against the flow and following rupture of the feedwater pipe, causes overpressure in the valve which is transmitted to the steam generator nozzle. It is therefore necessary to know this when designing the internal systems of the steam generator. Using the RELAP5/MODE3 code, it has been possible to simulate the dynamic behaviour of a check valve upon rupture of a feedwater pipe postulated outside the containment. The calculation model has been applied to different types of check valve. (Author)

Evaluation of Seismic Rupture Models for the 2011 Tohoku-Oki Earthquake Using Tsunami Simulation

Directory of Open Access Journals (Sweden)

Ming-Da Chiou

2013-01-01

Full Text Available Developing a realistic, three-dimensional rupture model of the large offshore earthquake is difficult to accomplish directly through band-limited ground-motion observations. A potential indirect method is using a tsunami simulation to verify the rupture model in reverse because the initial conditions of the associated tsunamis are caused by a coseismic seafloor displacement correlating to the rupture pattern along the main faulting. In this study, five well-developed rupture models for the 2011 Tohoku-Oki earthquake were adopted to evaluate differences in simulated tsunamis and various rupture asperities. The leading wave of the simulated tsunamis triggered by the seafloor displacement in Yamazaki et al. (2011 model resulted in the smallest root-mean-squared difference (~0.082 m on average from the records of the eight DART (Deep-ocean Assessment and Reporting of Tsunamis stations. This indicates that the main seismic rupture during the 2011 Tohoku earthquake should occur in a large shallow slip in a narrow range adjacent to the Japan trench. This study also quantified the influences of ocean stratification and tides which are normally overlooked in tsunami simulations. The discrepancy between the simulations with and without stratification was less than 5% of the first peak wave height at the eight DART stations. The simulations, run with and without the presence of tides, resulted in a ~1% discrepancy in the height of the leading wave. Because simulations accounting for tides and stratification are time-consuming and their influences are negligible, particularly in the first tsunami wave, the two factors can be ignored in a tsunami prediction for practical purposes.

Complementary roles of platelets and coagulation in thrombus formation on plaques acutely ruptured by targeted ultrasound treatment: a novel intravital model.

Science.gov (United States)

Kuijpers, M J E; Gilio, K; Reitsma, S; Nergiz-Unal, R; Prinzen, L; Heeneman, S; Lutgens, E; van Zandvoort, M A M J; Nieswandt, B; Egbrink, M G A Oude; Heemskerk, J W M

2009-01-01

Atherothrombosis is a major cause of cardiovascular events. However, animal models to study this process are scarce. We describe the first murine model of acute thrombus formation upon plaque rupture to study atherothrombosis by intravital fluorescence microscopy. Localized rupture of an atherosclerotic plaque in a carotid artery from Apoe(-/-) mice was induced in vivo using ultrasound. Rupture of the plaque and formation of localized thrombi were verified by two-photon laser scanning microscopy (TPLSM) in isolated arteries, and by immunohistochemistry. The thrombotic reaction was quantified by intravital fluorescence microscopy. Inspection of the ultrasound-treated plaques by histochemistry and TPLSM demonstrated local damage, collagen exposure, luminal thrombus formation as well as intra-plaque intrusion of erythrocytes and fibrin. Ultrasound treatment of healthy carotid arteries resulted in endothelial damage and limited platelet adhesion. Real-time intravital fluorescence microscopy demonstrated rapid platelet deposition on plaques and formation of a single thrombus that remained subocclusive. The thrombotic process was antagonized by thrombin inhibition, or by blocking of collagen or adenosine diphosphate receptor pathways. Multiple thrombi were formed in 70% of mice lacking CD40L. Targeted rupture of murine plaques results in collagen exposure and non-occlusive thrombus formation. The thrombotic process relies on platelet activation as well as on thrombin generation and coagulation, and is sensitive to established and novel antithrombotic medication. This model provides new possibilities to study atherothrombosis in vivo.

Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

Science.gov (United States)

Polzer, Stanislav; Gasser, T Christian

2015-12-06

A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. © 2015 The Author(s).

ARTIST: a cooperative safety project to study fission product retention in a ruptured steam generator

International Nuclear Information System (INIS)

Guentay, S.; Dehbi, A.; Suckow, D.; Birchley, J.

2001-01-01

Sequences such as a steam generator tube rupture (SGTR) with stuck-open relief valve represent a significant public risk by virtue of the open path for release of radioactivity. The release may be lessened by deposition of fission products on the steam generator (SG) tubes and other structures or by scrubbing in the secondary coolant. The absence of empirical data, the complexity of the geometry and controlling processes, however, make the retention difficult to quantify and credit for it is typically not taken in risk assessments. The ARTIST experimental program to be conducted at Paul Scherrer Institut, Switzerland, will simulate the flow and retention of aerosol-borne fission products in the SG secondary, and thus provide a unique database to support safety assessments and analytical models. The project, foreseen in seven phases, will study phenomena at the separate effect and integral levels, and also address accident management (AM) issues. The prescribed values of the controlling parameters (aerosol size, aerosol type, gas flow velocity, residence time, etc) cover the range expected in severe and design basis accident scenarios. (authors)

Rupture, waves and earthquakes.

Science.gov (United States)

Uenishi, Koji

2017-01-01

Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

Steam generator tube rupture risk impact on design and operation of French PWR plants

International Nuclear Information System (INIS)

Depond, G.; Sureau, H.

1984-01-01

The experience of steam generator tube leaks incidents in PWR plants has resulted in an increase of EDF analysis leading to improvements in design and post-accidental operation for new projects and operating plants. The accident consequences are minimized for each of the NSSS three barriers: first barrier: safeguard systems design and operating procedures relying upon core safety allow to maintain a low level of primary radioactivity, second barrier: steam generator design and periodic inspection allow to reduce tube ruptures risks and third barrier: atmospheric releases are reduced as a result of optimal recovery procedures, detection improvements and atmospheric steam valves design improvements. (orig.)

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

Science.gov (United States)

McDermott, Daniel J.; Schrader, Kenneth J.; Schulz, Terry L.

1994-01-01

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

Formation of a cavitation cluster in the vicinity of a quasi-empty rupture

Science.gov (United States)

Bol'shakova, E. S.; Kedrinskiy, V. K.

2017-09-01

The presentation deals with one of the experimental and numerical models of a quasi-empty rupture in the magma melt. This rupture is formed in the liquid layer of a distilled cavitating fluid under shock loading within the framework of the problem formulation with a small electromagnetic hydrodynamic shock tube. It is demonstrated that the rupture is shaped as a spherical segment, which retains its topology during the entire process of its evolution and collapsing. The dynamic behavior of the quasi-empty rupture is analyzed, and the growth of cavitating nuclei in the form of the boundary layer near the entire rupture interface is found. It is shown that rupture implosion is accompanied by the transformation of the bubble boundary layer to a cavitating cluster, which takes the form of a ring-shaped vortex floating upward to the free surface of the liquid layer. A p-κ mathematical model is formulated, and calculations are performed to investigate the implosion of a quasi-empty spherical cavity in the cavitating liquid, generation of a shock wave by this cavity, and dynamics of the bubble density growth in the cavitating cluster by five orders of magnitude.

CFD modeling of a boiler's tubes rupture

International Nuclear Information System (INIS)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi

2006-01-01

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320 MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-ε turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9 MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8 MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections

Conditional Probabilities of Large Earthquake Sequences in California from the Physics-based Rupture Simulator RSQSim

Science.gov (United States)

Gilchrist, J. J.; Jordan, T. H.; Shaw, B. E.; Milner, K. R.; Richards-Dinger, K. B.; Dieterich, J. H.

2017-12-01

Within the SCEC Collaboratory for Interseismic Simulation and Modeling (CISM), we are developing physics-based forecasting models for earthquake ruptures in California. We employ the 3D boundary element code RSQSim (Rate-State Earthquake Simulator of Dieterich & Richards-Dinger, 2010) to generate synthetic catalogs with tens of millions of events that span up to a million years each. This code models rupture nucleation by rate- and state-dependent friction and Coulomb stress transfer in complex, fully interacting fault systems. The Uniform California Earthquake Rupture Forecast Version 3 (UCERF3) fault and deformation models are used to specify the fault geometry and long-term slip rates. We have employed the Blue Waters supercomputer to generate long catalogs of simulated California seismicity from which we calculate the forecasting statistics for large events. We have performed probabilistic seismic hazard analysis with RSQSim catalogs that were calibrated with system-wide parameters and found a remarkably good agreement with UCERF3 (Milner et al., this meeting). We build on this analysis, comparing the conditional probabilities of sequences of large events from RSQSim and UCERF3. In making these comparisons, we consider the epistemic uncertainties associated with the RSQSim parameters (e.g., rate- and state-frictional parameters), as well as the effects of model-tuning (e.g., adjusting the RSQSim parameters to match UCERF3 recurrence rates). The comparisons illustrate how physics-based rupture simulators might assist forecasters in understanding the short-term hazards of large aftershocks and multi-event sequences associated with complex, multi-fault ruptures.

Analytical and experimental studies of mechanical consequences of a steam generator tube rupture

International Nuclear Information System (INIS)

Duc, B.; Sudreau, F.; Rassineux, B.

1995-01-01

Concerning to steam generator tubes support mechanical loadings due to the impact f the ruptured one, Electricite de France, with the support of Commissariat a l'Energie. Atomique, has undertaken a large study in order to evaluate the consequences of such loadings. This paper first presents the results of the tests performed on AQUITAINE 2 facility (CEA Cadarache research center) for nominal, faulted and boiler effect conditions. Those results are then compared with numerical dynamic elastoplastic analyses performed with CASTEM 2000 code (CEA system). (author). 1 ref., 14 figs

Global molecular changes in a tibial compression induced ACL rupture model of post-traumatic osteoarthritis.

Science.gov (United States)

Chang, Jiun C; Sebastian, Aimy; Murugesh, Deepa K; Hatsell, Sarah; Economides, Aris N; Christiansen, Blaine A; Loots, Gabriela G

2017-03-01

Joint injury causes post-traumatic osteoarthritis (PTOA). About ∼50% of patients rupturing their anterior cruciate ligament (ACL) will develop PTOA within 1-2 decades of the injury, yet the mechanisms responsible for the development of PTOA after joint injury are not well understood. In this study, we examined whole joint gene expression by RNA sequencing (RNAseq) at 1 day, 1-, 6-, and 12 weeks post injury, in a non-invasive tibial compression (TC) overload mouse model of PTOA that mimics ACL rupture in humans. We identified 1446 genes differentially regulated between injured and contralateral joints. This includes known regulators of osteoarthritis such as MMP3, FN1, and COMP, and several new genes including Suco, Sorcs2, and Medag. We also identified 18 long noncoding RNAs that are differentially expressed in the injured joints. By comparing our data to gene expression data generated using the surgical destabilization of the medial meniscus (DMM) PTOA model, we identified several common genes and shared mechanisms. Our study highlights several differences between these two models and suggests that the TC model may be a more rapidly progressing model of PTOA. This study provides the first account of gene expression changes associated with PTOA development and progression in a TC model. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. J Orthop Res 35:474-485, 2017. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc.

Global molecular changes in a tibial compression induced ACL rupture model of post‐traumatic osteoarthritis

Science.gov (United States)

Chang, Jiun C.; Sebastian, Aimy; Murugesh, Deepa K.; Hatsell, Sarah; Economides, Aris N.; Christiansen, Blaine A.

2016-01-01

ABSTRACT Joint injury causes post‐traumatic osteoarthritis (PTOA). About ∼50% of patients rupturing their anterior cruciate ligament (ACL) will develop PTOA within 1–2 decades of the injury, yet the mechanisms responsible for the development of PTOA after joint injury are not well understood. In this study, we examined whole joint gene expression by RNA sequencing (RNAseq) at 1 day, 1‐, 6‐, and 12 weeks post injury, in a non‐invasive tibial compression (TC) overload mouse model of PTOA that mimics ACL rupture in humans. We identified 1446 genes differentially regulated between injured and contralateral joints. This includes known regulators of osteoarthritis such as MMP3, FN1, and COMP, and several new genes including Suco, Sorcs2, and Medag. We also identified 18 long noncoding RNAs that are differentially expressed in the injured joints. By comparing our data to gene expression data generated using the surgical destabilization of the medial meniscus (DMM) PTOA model, we identified several common genes and shared mechanisms. Our study highlights several differences between these two models and suggests that the TC model may be a more rapidly progressing model of PTOA. This study provides the first account of gene expression changes associated with PTOA development and progression in a TC model. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. J Orthop Res 35:474–485, 2017. PMID:27088242

Rupture Dynamics and Seismic Radiation on Rough Faults for Simulation-Based PSHA

Science.gov (United States)

Mai, P. M.; Galis, M.; Thingbaijam, K. K. S.; Vyas, J. C.; Dunham, E. M.

2017-12-01

Simulation-based ground-motion predictions may augment PSHA studies in data-poor regions or provide additional shaking estimations, incl. seismic waveforms, for critical facilities. Validation and calibration of such simulation approaches, based on observations and GMPE's, is important for engineering applications, while seismologists push to include the precise physics of the earthquake rupture process and seismic wave propagation in 3D heterogeneous Earth. Geological faults comprise both large-scale segmentation and small-scale roughness that determine the dynamics of the earthquake rupture process and its radiated seismic wavefield. We investigate how different parameterizations of fractal fault roughness affect the rupture evolution and resulting near-fault ground motions. Rupture incoherence induced by fault roughness generates realistic ω-2 decay for high-frequency displacement amplitude spectra. Waveform characteristics and GMPE-based comparisons corroborate that these rough-fault rupture simulations generate realistic synthetic seismogram for subsequent engineering application. Since dynamic rupture simulations are computationally expensive, we develop kinematic approximations that emulate the observed dynamics. Simplifying the rough-fault geometry, we find that perturbations in local moment tensor orientation are important, while perturbations in local source location are not. Thus, a planar fault can be assumed if the local strike, dip, and rake are maintained. The dynamic rake angle variations are anti-correlated with local dip angles. Based on a dynamically consistent Yoffe source-time function, we show that the seismic wavefield of the approximated kinematic rupture well reproduces the seismic radiation of the full dynamic source process. Our findings provide an innovative pseudo-dynamic source characterization that captures fault roughness effects on rupture dynamics. Including the correlations between kinematic source parameters, we present a new

A Retrospective Analysis of Ruptured Breast Implants

Directory of Open Access Journals (Sweden)

Woo Yeol Baek

2014-11-01

Full Text Available BackgroundRupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants.MethodsWe performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone, duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management.ResultsForty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case, microfat graft (2 case, removal only (14 case, and follow-up loss (17 case.ConclusionsSaline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs.

Irregularities in Early Seismic Rupture Propagation for Large Events in a Crustal Earthquake Model

Science.gov (United States)

Lapusta, N.; Rice, J. R.; Rice, J. R.

2001-12-01

We study early seismic propagation of model earthquakes in a 2-D model of a vertical strike-slip fault with depth-variable rate and state friction properties. Our model earthquakes are obtained in fully dynamic simulations of sequences of instabilities on a fault subjected to realistically slow tectonic loading (Lapusta et al., JGR, 2000). This work is motivated by results of Ellsworth and Beroza (Science, 1995), who observe that for many earthquakes, far-field velocity seismograms during initial stages of dynamic rupture propagation have irregular fluctuations which constitute a "seismic nucleation phase". In our simulations, we find that such irregularities in velocity seismograms can be caused by two factors: (1) rupture propagation over regions of stress concentrations and (2) partial arrest of rupture in neighboring creeping regions. As rupture approaches a region of stress concentration, it sees increasing background stress and its moment acceleration (to which velocity seismographs in the far field are proportional) increases. After the peak in stress concentration, the rupture sees decreasing background stress and moment acceleration decreases. Hence a fluctuation in moment acceleration is created. If rupture starts sufficiently far from a creeping region, then partial arrest of rupture in the creeping region causes a decrease in moment acceleration. As the other parts of rupture continue to develop, moment acceleration then starts to grow again, and a fluctuation again results. Other factors may cause the irregularities in moment acceleration, e.g., phenomena such as branching and/or intermittent rupture propagation (Poliakov et al., submitted to JGR, 2001) which we have not studied here. Regions of stress concentration are created in our model by arrest of previous smaller events as well as by interactions with creeping regions. One such region is deep in the fault zone, and is caused by the temperature-induced transition from seismogenic to creeping

Fission product retention during faults involving steam generator tube rupture

International Nuclear Information System (INIS)

Rodliffe, R.S.

1983-08-01

In some PWR fault conditions, such as stuck open safety relief valve in the secondary circuit or main steam line break, the release of fission products to the atmosphere may be increased by the leakage of primary coolant into the secondary circuit following steam generator tube rupture. The release may be reduced by retention either within the primary circuit or within the affected steam generator unit (SGU). The mechanisms leading to retention are reviewed and quantified where possible. The parameters on which any analysis will be most critically dependent are identified. Fission product iodine and caesium may be retained in the secondary side of a SGU either by partition to retained water or by droplet deposition on surfaces and subsequent evaporation to dryness. Two extreme simplifications are considered: SGU 'dry', i.e. the secondary side is steam filled, and SGU 'wet', i.e. the tube bundle is covered with water. Consideration is given to: the distribution of fission products between gaseous and aerosol forms; mechanisms for droplet formation, deposition and resuspension; fission product retention during droplet or film evaporation primary coolant mixing and droplet scrubbing in a wet SGU; and the performance of moisture separators and steam driers. (author)

Critique of the Ford-Andresen film rupture model for aqueous stress corrosion cracking

International Nuclear Information System (INIS)

Hall, M.M.

2009-01-01

The Ford-Andresen film rupture model for aqueous stress corrosion cracking has obtained a prominent position in the nuclear reactor industry. The model is said to have superior predictive capabilities because it is derived from a fundamental understanding of the film rupture-repassivation mechanism of crack advance. However, a critical review shows that there are conceptual and mathematical problems with the Ford-Andresen model development; there are inconsistencies among the stated and implied assumptions, the crack tip current density expression lacks the necessary dependence on crack tip strain rate and the fundamental proportionality that exists between crack tip strain rate and crack growth rate is overlooked and omitted from the model development. Consequently, the Ford-Andresen model must be considered neither phenomenologically nor fundamentally supported.

A Critique of a Phenomenological Fiber Breakage Model for Stress Rupture of Composite Materials

Science.gov (United States)

Reeder, James R.

2010-01-01

Stress rupture is not a critical failure mode for most composite structures, but there are a few applications where it can be critical. One application where stress rupture can be a critical design issue is in Composite Overwrapped Pressure Vessels (COPV's), where the composite material is highly and uniformly loaded for long periods of time and where very high reliability is required. COPV's are normally required to be proof loaded before being put into service to insure strength, but it is feared that the proof load may cause damage that reduces the stress rupture reliability. Recently, a fiber breakage model was proposed specifically to estimate a reduced reliability due to proof loading. The fiber breakage model attempts to model physics believed to occur at the microscopic scale, but validation of the model has not occurred. In this paper, the fiber breakage model is re-derived while highlighting assumptions that were made during the derivation. Some of the assumptions are examined to assess their effect on the final predicted reliability.

Analysis of steam generator tube rupture as a severe accident using MELCOR 1.8.4

International Nuclear Information System (INIS)

Yang Hongrun; Hidaka, Akihide; Sugimoto, Jun

1999-03-01

This report presents the results from the MELCOR 1.8.4 calculations for Steam Generator Tube Rupture (SGTR) with stuck open of all the safety valves in faulted SG as a severe accident. The calculations are based on Surry nuclear power plant. After performed using the once-through primary system model alone by 1.0x10 5 s, the calculations were conducted with both of the once-through and the hot leg countercurrent natural circulation models. The results, including event sequences, processes and progressions of core degradation, radionuclides release from core and reactor cavity, and source terms to the environment are described in detail. It is concluded that the availability of High Pressure Safety Injection (HPSI) can significantly delay the progression of core heat-up and approximately 7% of cesium iodide (CsI) can be released to the environment directly through the stuck open safety valve. Comparisons between the results from the two models are also given in this report. The present analyses also showed that during SGTR accident, the hot leg countercurrent natural circulation flow cannot be established well and therefore it has little effect on the mitigation of the core degradation. (author)

Pseudodynamic Source Characterization for Strike-Slip Faulting Including Stress Heterogeneity and Super-Shear Ruptures

KAUST Repository

Mena, B.

2012-08-08

Reliable ground‐motion prediction for future earthquakes depends on the ability to simulate realistic earthquake source models. Though dynamic rupture calculations have recently become more popular, they are still computationally demanding. An alternative is to invoke the framework of pseudodynamic (PD) source characterizations that use simple relationships between kinematic and dynamic source parameters to build physically self‐consistent kinematic models. Based on the PD approach of Guatteri et al. (2004), we propose new relationships for PD models for moderate‐to‐large strike‐slip earthquakes that include local supershear rupture speed due to stress heterogeneities. We conduct dynamic rupture simulations using stochastic initial stress distributions to generate a suite of source models in the magnitude Mw 6–8. This set of models shows that local supershear rupture speed prevails for all earthquake sizes, and that the local rise‐time distribution is not controlled by the overall fault geometry, but rather by local stress changes on the faults. Based on these findings, we derive a new set of relations for the proposed PD source characterization that accounts for earthquake size, buried and surface ruptures, and includes local rise‐time variations and supershear rupture speed. By applying the proposed PD source characterization to several well‐recorded past earthquakes, we verify that significant improvements in fitting synthetic ground motion to observed ones is achieved when comparing our new approach with the model of Guatteri et al. (2004). The proposed PD methodology can be implemented into ground‐motion simulation tools for more physically reliable prediction of shaking in future earthquakes.

ANALISIS KEJADIAN STEAM GENERATOR TUBE RUPTURE (SGTR BERDASARKAN SKENARIO MIHAMA UNIT 2

Directory of Open Access Journals (Sweden)

Andi Sofrany Ekariansyah

2015-03-01

Full Text Available Pada tanggal 9 Februari 1991, terjadi kecelakaan putusnya pipa pemanas pembangkit uap (Steam Generator Tube Rupture/SGTR pada PLTN Mihama Unit 2. Dari kejadian tersebut, diperoleh catatan sekuensi kecelakaan berupa aktuasi sistem proteksi dan fitur keselamatan terekayasa dalam memitigasi kebocoran dari sistem primer ke sistem sekunder. Urutan sekuensi tersebut kemudian diterapkan pada PWR standar Jepang untuk disimulasikan menggunakan program perhitungan RELAP5/SCDAP/Mod3.2. Tujuannya untuk mengevaluasi konsekuensi yang terjadi bila kecelakaan tersebut terjadi pada PWR standar Jepang. Parameter yang dibandingkan adalah laju alir kebocoran, perubahan tekanan primer dan sekunder dan perubahan level di dalam pressurizer. Hasil simulasi menunjukkan perbedaan lama waktu kejadian SGTR hingga berhentinya kebocoran yang berlangsung lebih pendek pada PWR standar Jepang. Selain itu jumlah pendingin primer yang bocor dan jumlah uap yang terlepas dari MSRV tercatat lebih besar daripada PWR Mihama unit 2. Karakter aliran kebocoran, fluktuasi tekanan primer, dan level pressurizer sedikit berbeda pada tahap-tahap awal kejadian, namun relatif sama pada tahap akhir ketika aliran kebocoran dapat dihentikan. Hasil simulasi juga menunjukkan perlunya tindakan operator secara manual yang ditunjukkan dari isolasi sistem air umpan bantu (AFW pada pembangkit uap yang bocor, aktuasi katup pelepas uap (MSRV pada pembangkit uap yang utuh dan aktuasi auxiliary spray dan power operated relief valve (PORV pada pressurizer untuk mengantisipasi kejadian sebagai bagian dari prosedur operasi darurat. Kata kunci: SGTR, PWR Mihama Unit 2, PWR standar Jepang   On February 9,1991, a Steam Generator Tube Rupture (SGTR took place at the Mihama Unit No. 2. From that event, the accident sequence representing the actuation of protection system and engineered safety feature to mitigate the leak from primary system to secondary system is recorded. That sequence is then applied on the

Coincident steam generator tube rupture and stuck-open safety relief valve carryover tests: MB-2 steam generator transient response test program

International Nuclear Information System (INIS)

Garbett, K.; Mendler, O.J.; Gardner, G.C.; Garnsey, R.; Young, M.Y.

1987-03-01

In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. In addition to the release of fission products from the bulk steam generator water by moisture carryover, there exists the possibility that some primary coolant may be released without having first mixed with the bulk water - a process called primary coolant bypassing. The MB-2 Phase II test program was designed specifically to identify the processes for droplet carryover during SGTR faults and to provide data of sufficient accuracy for use in developing physical models and computer codes to describe activity release. The test program consisted of sixteen separate tests designed to cover a range of steady-state and transient fault conditions. These included a full SGTR/SORV transient simulation, two SGTR overfill tests, ten steady-state SGTR tests at water levels ranging from very low levels in the bundle up to those when the dryer was flooded, and three moisture carryover tests without SGTR. In these tests the influence of break location and the effect of bypassing the dryer were also studied. In a final test the behavior with respect to aerosol particles in a dry steam generator, appropriate to a severe accident fault, was investigated

Early Ankle Mobilization Promotes Healing in a Rabbit Model of Achilles Tendon Rupture.

Science.gov (United States)

Jielile, Jiasharete; Asilehan, Batiza; Wupuer, Aikeremu; Qianman, Bayixiati; Jialihasi, Ayidaer; Tangkejie, Wulanbai; Maimaitiaili, Abudouheilil; Shawutali, Nuerai; Badelhan, Aynaz; Niyazebieke, Hadelebieke; Aizezi, Adili; Aisaiding, Amuding; Bakyt, Yerzat; Aibek, Rakimbaiev; Wuerliebieke, Jianati

2016-01-01

The use of early mobilization of the ankle joint without orthosis in the treatment of Achilles tendon rupture has been advocated as the optimal management. The goal of this study was to compare outcomes in a postoperative rabbit model of Achilles tendon rupture between early mobilization and immobilized animals using a differential proteomics approach. In total, 135 rabbits were randomized into the control group (n=15), the postoperative cast immobilization (PCI) group (n=60), and the early mobilization (EM) group (n=60). A rupture of the Achilles tendon was created in each animal model and repaired microsurgically, and tendon samples were removed at 3, 7, 14, and 21 days postoperatively. Proteins were separated using 2-dimensional polyacrylamide gel electrophoresis and identified using peptide mass fingerprinting, tandem mass spectrometry, NCBI database searches, and bioinformatics analyses. A series of differentially expressed proteins were identified between groups, some of which may play an important role in Achilles tendon healing. Notable candidate proteins that were upregulated in the EM group were identified, such as CRMP-2, galactokinase 1, tropomyosin-4, and transthyretin. The healing of ruptured Achilles tendons appears to be affected at the level of protein expression with the use of early mobilization. The classic postoperative treatment of Achilles tendon rupture with an orthosis ignored the self-protecting instinct of humans. With a novel operative technique, the repaired tendon can persist the load that comes from traction in knee and ankle joint functional movement. In addition, kinesitherapy provided an excellent experimental outcome via a mechanobiological mechanism. Copyright 2016, SLACK Incorporated.

Morphological parameters associated with ruptured posterior communicating aneurysms.

Science.gov (United States)

Ho, Allen; Lin, Ning; Charoenvimolphan, Nareerat; Stanley, Mary; Frerichs, Kai U; Day, Arthur L; Du, Rose

2014-01-01

The rupture risk of unruptured intracranial aneurysms is known to be dependent on the size of the aneurysm. However, the association of morphological characteristics with ruptured aneurysms has not been established in a systematic and location specific manner for the most common aneurysm locations. We evaluated posterior communicating artery (PCoA) aneurysms for morphological parameters associated with aneurysm rupture in that location. CT angiograms were evaluated to generate 3-D models of the aneurysms and surrounding vasculature. Univariate and multivariate analyses were performed to evaluate morphological parameters including aneurysm volume, aspect ratio, size ratio, distance to ICA bifurcation, aneurysm angle, vessel angles, flow angles, and vessel-to-vessel angles. From 2005-2012, 148 PCoA aneurysms were treated in a single institution. Preoperative CTAs from 63 patients (40 ruptured, 23 unruptured) were available and analyzed. Multivariate logistic regression revealed that smaller volume (p = 0.011), larger aneurysm neck diameter (0.048), and shorter ICA bifurcation to aneurysm distance (p = 0.005) were the most strongly associated with aneurysm rupture after adjusting for all other clinical and morphological variables. Multivariate subgroup analysis for patients with visualized PCoA demonstrated that larger neck diameter (p = 0.018) and shorter ICA bifurcation to aneurysm distance (p = 0.011) were significantly associated with rupture. Intracerebral hemorrhage was associated with smaller volume, larger maximum height, and smaller aneurysm angle, in addition to lateral projection, male sex, and lack of hypertension. We found that shorter ICA bifurcation to aneurysm distance is significantly associated with PCoA aneurysm rupture. This is a new physically intuitive parameter that can be measured easily and therefore be readily applied in clinical practice to aid in the evaluation of patients with PCoA aneurysms.

Intrinsic, Transitional, and Extrinsic Morphological Factors Associated With Rupture of Intracranial Aneurysms.

Science.gov (United States)

Ho, Allen L; Lin, Ning; Frerichs, Kai U; Du, Rose

2015-09-01

As diagnosis and treatment of unruptured intracranial aneurysms continues to increase, management principles remain largely based on size. This is despite mounting evidence that aneurysm location and other morphologic variables could play a role in predicting overall risk of rupture. Morphological parameters can be divided into 3 main groups, those that are intrinsic to the aneurysm, those that are extrinsic to the aneurysm, and those that involve both the aneurysm and surrounding vasculature (transitional). We present an evaluation of intrinsic, transitional, and extrinsic factors and their association with ruptured aneurysms. Using preoperative computed tomographic angiography, we generated 3-dimensional models of aneurysms and their surrounding vasculature with Slicer software. Using univariate and multivariate analyses, we examined the association of intrinsic, transitional, and extrinsic aspects of aneurysm morphology with rupture. Between 2005 and 2013, 227 cerebral aneurysms in 4 locations were evaluated/treated at a single institution, and computed tomographic angiographies of 218 patients (97 unruptured and 130 ruptured) were analyzed. Ruptured aneurysms analyzed were associated with clinical factors of absence of multiple aneurysms and history of no prior rupture, and morphologic factors of greater aspect ratio. On multivariate analysis, aneurysm rupture remained associated with history of no prior rupture, greater flow angle, greater daughter-daughter vessel angle, and smaller parent-daughter vessel angle. By studying the morphology of aneurysms and their surrounding vasculature, we identified several parameters associated with ruptured aneurysms that include intrinsic, transitional, and extrinsic factors of cerebral aneurysms and their surrounding vasculature.

Rupture Dynamics and Ground Motion from Earthquakes in Heterogeneous Media

Science.gov (United States)

Bydlon, S.; Dunham, E. M.; Kozdon, J. E.

2012-12-01

Heterogeneities in the material properties of Earth's crust scatter propagating seismic waves. The effects of scattered waves are reflected in the seismic coda and depend on the relative strength of the heterogeneities, spatial arrangement, and distance from source to receiver. In the vicinity of the fault, scattered waves influence the rupture process by introducing fluctuations in the stresses driving propagating ruptures. Further variability in the rupture process is introduced by naturally occurring geometric complexity of fault surfaces, and the stress changes that accompany slip on rough surfaces. We have begun a modeling effort to better understand the origin of complexity in the earthquake source process, and to quantify the relative importance of source complexity and scattering along the propagation path in causing incoherence of high frequency ground motion. To do this we extended our two-dimensional high order finite difference rupture dynamics code to accommodate material heterogeneities. We generate synthetic heterogeneous media using Von Karman correlation functions and their associated power spectral density functions. We then nucleate ruptures on either flat or rough faults, which obey strongly rate-weakening friction laws. Preliminary results for flat faults with uniform frictional properties and initial stresses indicate that off-fault material heterogeneity alone can lead to a complex rupture process. Our simulations reveal the excitation of high frequency bursts of waves, which radiate energy away from the propagating rupture. The average rupture velocity is thus reduced relative to its value in simulations employing homogeneous material properties. In the coming months, we aim to more fully explore parameter space by varying the correlation length, Hurst exponent, and amplitude of medium heterogeneities, as well as the statistical properties characterizing fault roughness.

Indigenous development of rupture discs for FBTR (Paper No. 028)

International Nuclear Information System (INIS)

Chetal, S.C.; Raju, Chander; Anandkumar, V.; Seetharaman, V.

1987-02-01

Rupture discs are required as a safety device for protecting the secondary sodium circuit and its components against high pressure surges due to accidental water-steam leaks in sodium heated steam generator and the consequent sodium water reaction. For identical reasons, rupture discs are also required on the vessels used for decontamination of sodium components. As an import substitution of the costly items for the FBTR Project, development of the rupture disc assemblies has been in progress at Indira Gandhi Centre for Atomic Research, Kalpakkam. Reverse buckling knife blade concept with stainless steel disc has been taken up for development. Hydroforming process without any die has been selected for disc fabrication. One rupture disc assembly required for steam generator has been tested in sodium satisfactorily. (author). 4 tables, 5 figs

In-reactor creep rupture of 20% cold-worked AISI 316 stainless steel

International Nuclear Information System (INIS)

Lovell, A.J.; Chin, B.A.; Gilbert, E.R.

1981-01-01

Results of an experiment designed to measure in-reactor stress-to-rupture properties of 20% cold-worked AISI 316 stainless steel are reported. The in-reactor rupture data are compared with postirradiation and unirradiated test results. In-reactor rupture lives were found to exceed rupture predictions of postirradiation tests. This longer in-reactor rupture life is attributed to dynamic point defect generation which is absent during postirradiation testing. The in-reactor stress-to-rupture properties are shown to be equal to or greater than the unirradiated material stress-to-rupture properties for times up to 7000 h. (author)

Fluid-Structure Interaction Analysis of Ruptured Mitral Chordae Tendineae.

Science.gov (United States)

Toma, Milan; Bloodworth, Charles H; Pierce, Eric L; Einstein, Daniel R; Cochran, Richard P; Yoganathan, Ajit P; Kunzelman, Karyn S

2017-03-01

The chordal structure is a part of mitral valve geometry that has been commonly neglected or simplified in computational modeling due to its complexity. However, these simplifications cannot be used when investigating the roles of individual chordae tendineae in mitral valve closure. For the first time, advancements in imaging, computational techniques, and hardware technology make it possible to create models of the mitral valve without simplifications to its complex geometry, and to quickly run validated computer simulations that more realistically capture its function. Such simulations can then be used for a detailed analysis of chordae-related diseases. In this work, a comprehensive model of a subject-specific mitral valve with detailed chordal structure is used to analyze the distinct role played by individual chordae in closure of the mitral valve leaflets. Mitral closure was simulated for 51 possible chordal rupture points. Resultant regurgitant orifice area and strain change in the chordae at the papillary muscle tips were then calculated to examine the role of each ruptured chorda in the mitral valve closure. For certain subclassifications of chordae, regurgitant orifice area was found to trend positively with ruptured chordal diameter, and strain changes correlated negatively with regurgitant orifice area. Further advancements in clinical imaging modalities, coupled with the next generation of computational techniques will enable more physiologically realistic simulations.

The 2016-2017 Central Italy Seismic Sequence: Source Complexity Inferred from Rupture Models.

Science.gov (United States)

Scognamiglio, L.; Tinti, E.; Casarotti, E.; Pucci, S.; Villani, F.; Cocco, M.; Magnoni, F.; Michelini, A.

2017-12-01

The Apennines have been struck by several seismic sequences in recent years, showing evidence of the activation of multiple segments of normal fault systems in a variable and, relatively short, time span, as in the case of the 1980 Irpinia earthquake (three shocks in 40 s), the 1997 Umbria-Marche sequence (four main shocks in 18 days) and the 2009 L'Aquila earthquake having three segments activated within a few weeks. The 2016-2017 central Apennines seismic sequence begin on August 24th with a MW 6.0 earthquake, which strike the region between Amatrice and Accumoli causing 299 fatalities. This earthquake ruptures a nearly 20 km long normal fault and shows a quite heterogeneous slip distribution. On October 26th, another main shock (MW 5.9) occurs near Visso extending the activated seismogenic area toward the NW. It is a double event rupturing contiguous patches on the fault segment of the normal fault system. Four days after the second main shock, on October 30th, a third earthquake (MW 6.5) occurs near Norcia, roughly midway between Accumoli and Visso. In this work we have inverted strong motion waveforms and GPS data to retrieve the source model of the MW 6.5 event with the aim of interpreting the rupture process in the framework of this complex sequence of moderate magnitude earthquakes. We noted that some preliminary attempts to model the slip distribution of the October 30th main shock using a single fault plane oriented along the Apennines did not provide convincing fits to the observed waveforms. In addition, the deformation pattern inferred from satellite observations suggested the activation of a multi-fault structure, that is coherent to the complexity and the extension of the geological surface deformation. We investigated the role of multi-fault ruptures and we found that this event revealed an extraordinary complexity of the rupture geometry and evolution: the coseismic rupture propagated almost simultaneously on a normal fault and on a blind fault

Rupture model based on non-associated plasticity

Science.gov (United States)

Pradeau, Adrien; Yoon, Jeong Whan; Thuillier, Sandrine; Lou, Yanshan; Zhang, Shunying

2018-05-01

This research work is about modeling the mechanical behavior of metallic sheets of AA6016 up to rupture using non-associated flow rule. Experiments were performed at room temperature in uniaxial tension and simple shear in different directions according to the rolling direction and an additional hydraulic bulge test. The anisotropy of the material is described by a Yld2000-2d yield surface [1], calibrated by stress ratios, and a plastic potential represented by Hill1948 [2], calibrated using Lankford coefficients. That way, the former is able to reproduce the yield stresses in different directions and the latter is able to reproduce the deformations in different directions as well [3], [4]. Indeed, the non-associated flow rule allows for the direction of the plastic flow not to be necessarily normal to the yield surface. Concerning the rupture, the macroscopic ductile fracture criterion DF2014 was used [5]. It indirectly uses the three invariants of the stress tensor by using the three following parameters: the stress triaxiality η, the Lode parameter L and the equivalent plastic strain to fracture ∈f-p . In order to be consistent with the plastic model and to add more flexibility to the p criterion, the equivalent stress σ ¯ and the equivalent strain to fracture ∈f-p have been substituted respectively as Yld2000-2d and Hill1948 in the DF2014 fracture criterion. The parameters for the fracture criterion were obtained by optimization and the fracture locus can be plotted in the (η ,L ,∈-p) space. The damage indicator D is then numerically predicted with respect of average strain values. A good correlation with the experimental results is obtained.

Double rupture disc experience

International Nuclear Information System (INIS)

1979-01-01

Result of these observations, comparisons and evaluations can be summarized in the following list of concerns regarding the use of double rupture discs coupled to the liquid space of a steam generator that is subjected to a large leak sodium water reaction event. Single rupture disc show delayed collapse characteristics in LLTR Series I and double disc assemblies are presumed to be more complex with additional delay before opening to give pressure relief. Delayed failure increases pressures in the IHTS and must be adequately covered by design requirements. With CRBR design, the first disc may fail only partially reducing the loading on the second disc with the result that relief performance may not meet requirements

Probability of a steam generator tube rupture due to the presence of axial through wall cracks

International Nuclear Information System (INIS)

Mavko, B.; Cizelj, L.

1991-01-01

Using the Leak-Before-Break (LBB) approach to define tube plugging criteria a possibility to operate with through wall crack(s) in steam generator tubes may be considered. This fact may imply an increase in tube rupture probability. Improved examination techniques (in addition to the 100% tube examination) have been developed and introduced to counterbalance the associated risk. However no estimates of the amount of total increase or decrease of risk due to the introduction of LBB have been made. A scheme to predict this change of risk is proposed in the paper, based on probabilistic fracture mechanics analysis of axial cracks combined with available data of steam generator tube nondestructive examination reliability. (author)

Multi-Fault Rupture Scenarios in the Brawley Seismic Zone

Science.gov (United States)

Kyriakopoulos, C.; Oglesby, D. D.; Rockwell, T. K.; Meltzner, A. J.; Barall, M.

2017-12-01

Dynamic rupture complexity is strongly affected by both the geometric configuration of a network of faults and pre-stress conditions. Between those two, the geometric configuration is more likely to be anticipated prior to an event. An important factor in the unpredictability of the final rupture pattern of a group of faults is the time-dependent interaction between them. Dynamic rupture models provide a means to investigate this otherwise inscrutable processes. The Brawley Seismic Zone in Southern California is an area in which this approach might be important for inferring potential earthquake sizes and rupture patterns. Dynamic modeling can illuminate how the main faults in this area, the Southern San Andreas (SSAF) and Imperial faults, might interact with the intersecting cross faults, and how the cross faults may modulate rupture on the main faults. We perform 3D finite element modeling of potential earthquakes in this zone assuming an extended array of faults (Figure). Our results include a wide range of ruptures and fault behaviors depending on assumptions about nucleation location, geometric setup, pre-stress conditions, and locking depth. For example, in the majority of our models the cross faults do not strongly participate in the rupture process, giving the impression that they are not typically an aid or an obstacle to the rupture propagation. However, in some cases, particularly when rupture proceeds slowly on the main faults, the cross faults indeed can participate with significant slip, and can even cause rupture termination on one of the main faults. Furthermore, in a complex network of faults we should not preclude the possibility of a large event nucleating on a smaller fault (e.g. a cross fault) and eventually promoting rupture on the main structure. Recent examples include the 2010 Mw 7.1 Darfield (New Zealand) and Mw 7.2 El Mayor-Cucapah (Mexico) earthquakes, where rupture started on a smaller adjacent segment and later cascaded into a larger

Safety design guide for pipe rupture protection for CANDU 9

International Nuclear Information System (INIS)

Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young; A. C. D. Wright

1996-03-01

This safety design guide for pipe rupture protection identifies high-energy systems in which pipe ruptures must be postulated to occur, as well as systems that must be protected from the dynamic effects of such ruptures. Dynamic effects considered in this SDG consist of pipe whip (including missiles generated by pipe ruptures, if any) and jet impingement, Requirements for protection against the dynamic effects of a postulated pipe rupture and method of protection of essential structures, systems and components are specified for these effects. The change status for the regulatory requirements, code and standards should be traced and this safety design guide shall be updated accordingly. 2 tabs., 5 refs. (Author) .new

CATHENA simulations of steam generator tube rupture

International Nuclear Information System (INIS)

Abdul-Razzak, A.; Lin, M.R.; Wright, A.C.D.

1997-01-01

The CATHENA thermalhydraulic computer code was used to simulate various scenarios following a CANDU 9 steam generator tube rupture (SGTR) event. The analysis included cases with class IV power and emergency core cooling system (ECCS) available and other cases with subsequent loss of class IV power (LCIVP) or impairment of ECCS injection. Two main approaches were followed in the analysis of each case. In the first approach, D 2 O feed was credited to provide conservative data for input to radionuclide release and dose calculations. Also operator actions are credited. The other approach is designed to give conservative predictions with respect to the acceptance criteria of fuel and fuel channel integrity and to prove that in case of such event, the operator will have enough time to mitigate the consequences. This is done by not crediting makeup for the inventory loss and relying on the automatic operation of safety systems. The analysis of the cases of the first approach provided the required data for radionuclide release and dose calculations and gave a good insight into the required sequence of operator timely actions to mitigate the consequences of such event. On the other hand, the cases of the second approach confirmed compliance with regulatory requirements for pressure tube and fuel integrity. The runs with ECCS available, showed the ECCS injection is effective in filling and cooling the core and that regulatory requirement's for fuel and channel integrity are met. In the event of ECCS impairment, the earliest indication of late fuel heat-up is late enough to provide the operator with an adequate time to act in mitigating the consequences of this event. (author)

Induced seismicity provides insight into why earthquake ruptures stop

KAUST Repository

Galis, Martin

2017-12-21

Injection-induced earthquakes pose a serious seismic hazard but also offer an opportunity to gain insight into earthquake physics. Currently used models relating the maximum magnitude of injection-induced earthquakes to injection parameters do not incorporate rupture physics. We develop theoretical estimates, validated by simulations, of the size of ruptures induced by localized pore-pressure perturbations and propagating on prestressed faults. Our model accounts for ruptures growing beyond the perturbed area and distinguishes self-arrested from runaway ruptures. We develop a theoretical scaling relation between the largest magnitude of self-arrested earthquakes and the injected volume and find it consistent with observed maximum magnitudes of injection-induced earthquakes over a broad range of injected volumes, suggesting that, although runaway ruptures are possible, most injection-induced events so far have been self-arrested ruptures.

Radioactivity release vs probability for a steam generator tube rupture accident

International Nuclear Information System (INIS)

Buslik, A.J.; Hall, R.E.

1978-01-01

A calculation of the probability of obtaining various radioactivity releases from a steam generator tube rupture (SGTR) is presented. The only radioactive isotopes considered are Iodine-131 and Xe-133. The particular accident path considered consists of a double-ended guillotine SGTR followed by loss of offsite power (LOSP). If there is no loss of offsite power, and no system fault other than the SGTR, it is judged that the consequences will be minimal, since the amount of iodine released through the condenser air ejector is expected to be quite small; this is a consequence of the fact that the concentration of iodine in the vapor released from the condenser air ejector is very small compared to that dissolved in the condensate water. In addition, in some plants the condenser air ejector flow is automatically diverted to containment or a high-activity alarm. The analysis presented here is for a typical Westinghouse PWR such as described in RESAR-3S

Salient Features of the 2015 Gorkha, Nepal Earthquake in Relation to Earthquake Cycle and Dynamic Rupture Models

Science.gov (United States)

Ampuero, J. P.; Meng, L.; Hough, S. E.; Martin, S. S.; Asimaki, D.

2015-12-01

Two salient features of the 2015 Gorkha, Nepal, earthquake provide new opportunities to evaluate models of earthquake cycle and dynamic rupture. The Gorkha earthquake broke only partially across the seismogenic depth of the Main Himalayan Thrust: its slip was confined in a narrow depth range near the bottom of the locked zone. As indicated by the belt of background seismicity and decades of geodetic monitoring, this is an area of stress concentration induced by deep fault creep. Previous conceptual models attribute such intermediate-size events to rheological segmentation along-dip, including a fault segment with intermediate rheology in between the stable and unstable slip segments. We will present results from earthquake cycle models that, in contrast, highlight the role of stress loading concentration, rather than frictional segmentation. These models produce "super-cycles" comprising recurrent characteristic events interspersed by deep, smaller non-characteristic events of overall increasing magnitude. Because the non-characteristic events are an intrinsic component of the earthquake super-cycle, the notion of Coulomb triggering or time-advance of the "big one" is ill-defined. The high-frequency (HF) ground motions produced in Kathmandu by the Gorkha earthquake were weaker than expected for such a magnitude and such close distance to the rupture, as attested by strong motion recordings and by macroseismic data. Static slip reached close to Kathmandu but had a long rise time, consistent with control by the along-dip extent of the rupture. Moreover, the HF (1 Hz) radiation sources, imaged by teleseismic back-projection of multiple dense arrays calibrated by aftershock data, was deep and far from Kathmandu. We argue that HF rupture imaging provided a better predictor of shaking intensity than finite source inversion. The deep location of HF radiation can be attributed to rupture over heterogeneous initial stresses left by the background seismic activity

Slip heterogeneity, body-wave spectra, and directivity of earthquake ruptures

OpenAIRE

Bernard, P.; Herrero, A.

1994-01-01

We present a broadband kinematic model based on a self-similar k-square distribution of the coseismic slip, with an instantaneous rise-time and a constant rupture velocity. The phase of the slip spectrum at high wave number is random. This model generates an ?-squared body-wave radiation, and a particular directivity factor C2d scaling the amplitude of the body-wave spectra, where Cd is the standard directivity factor. Considering the source models with a propagating pulse and a finite rise-t...

RELAP5 model to simulate the thermal-hydraulic effects of grid spacers and cladding rupture during reflood

Energy Technology Data Exchange (ETDEWEB)

Nithianandan, C.K.; Klingenfus, J.A.; Reilly, S.S. [B& W Nuclear Technologies, Lynchburg, VA (United States)

1995-09-01

Droplet breakup at spacer grids and a cladding swelled and ruptured locations plays an important role in the cooling of nuclear fuel rods during the reflooding period of a loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). During the reflood phase, a spacer grid affects the thermal-hydraulic system behavior through increased turbulence, droplet breakup due to impact on grid straps, grid rewetting, and liquid holdup due to grid form losses. Recently, models to simulate spacer grid effects and blockage and rupture effects on system thermal hydraulics were added to the B&W Nuclear Technologies (BWNT) version of the RELAP5/MOD2 computer code. Several FLECHT-SEASET forced reflood tests, CCTF Tests C1-19 and C2-6, SCTF Test S3-15, and G2 Test 561 were simulated using RELAP5/MOD2-B&W to verify the applicability of the model at the cladding swelled and rupture locations. The results demonstrate the importance of modeling the thermal-hydraulic effects due to grids, and clad swelling and rupture to correctly predict the clad temperature response during the reflood phase of large break LOCA. The RELAP5 models and the test results are described in this paper.

CFD modeling of a boiler's tubes rupture

Energy Technology Data Exchange (ETDEWEB)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi [Chemical Engineering Department, Faculty of Engineering, Razi University, Kermanshah (Iran)

2006-12-15

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-{epsilon} turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections. (author)

Size ratio correlates with intracranial aneurysm rupture status: a prospective study.

Science.gov (United States)

Rahman, Maryam; Smietana, Janel; Hauck, Erik; Hoh, Brian; Hopkins, Nick; Siddiqui, Adnan; Levy, Elad I; Meng, Hui; Mocco, J

2010-05-01

The prediction of intracranial aneurysm (IA) rupture risk has generated significant controversy. The findings of the International Study of Unruptured Intracranial Aneurysms (ISUIA) that small anterior circulation aneurysms (IAs are small. These discrepancies have led to the search for better aneurysm parameters to predict rupture. We previously reported that size ratio (SR), IA size divided by parent vessel diameter, correlated strongly with IA rupture status (ruptured versus unruptured). These data were all collected retrospectively off 3-dimensional angiographic images. Therefore, we performed a blinded prospective collection and evaluation of SR data from 2-dimensional angiographic images for a consecutive series of patients with ruptured and unruptured IAs. We prospectively enrolled 40 consecutive patients presenting to a single institution with either ruptured IA or for first-time evaluation of an incidental IA. Blinded technologists acquired all measurements from 2-dimensional angiographic images. Aneurysm rupture status, location, IA maximum size, and parent vessel diameter were documented. The SR was calculated by dividing the aneurysm size (mm) by the average parent vessel size (mm). A 2-tailed Mann-Whitney test was performed to assess statistical significance between ruptured and unruptured groups. Fisher exact test was used to compare medical comorbidities between the ruptured and unruptured groups. Significant differences between the 2 groups were subsequently tested with logistic regression. SE and probability values are reported. Forty consecutive patients with 24 unruptured and 16 ruptured aneurysms met the inclusion criteria. No significant differences were found in age, gender, smoking status, or medical comorbidities between ruptured and unruptured groups. The average maximum size of the unruptured IAs (6.18 + or - 0.60 mm) was significantly smaller compared with the ruptured IAs (7.91 + or - 0.47 mm; P=0.03), and the unruptured group had

Steam generator tube failures

International Nuclear Information System (INIS)

MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

1996-04-01

A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service

Toward tsunami early warning system in Indonesia by using rapid rupture durations estimation

International Nuclear Information System (INIS)

Madlazim

2012-01-01

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

Rupture Propagation through the Big Bend of the San Andreas Fault: A Dynamic Modeling Case Study of the Great Earthquake of 1857

Science.gov (United States)

Lozos, J.

2017-12-01

The great San Andreas Fault (SAF) earthquake of 9 January 1857, estimated at M7.9, was one of California's largest historic earthquakes. Its 360 km rupture trace follows the Carrizo and Mojave segments of the SAF, including the 30° compressional Big Bend in the fault. If 1857 were a characteristic rupture, the hazard implications for southern California would be dire, especially given the inferred 150 year recurrence interval for this section of the fault. However, recent paleoseismic studies in this region suggest that 1857-type events occur less frequently than single-segment Carrizo or Mojave ruptures, and that the hinge of the Big Bend is a barrier to through-going rupture. Here, I use 3D dynamic rupture modeling to attempt to reproduce the rupture length and surface slip distribution of the 1857 earthquake, to determine which physical conditions allow rupture to negotiate the Big Bend of the SAF. These models incorporate the nonplanar geometry of the SAF, an observation-based heterogeneous regional velocity structure (SCEC CVM), and a regional stress field from seismicity literature. Under regional stress conditions, I am unable to produce model events that both match the observed surface slip on the Carrizo and Mojave segments of the SAF and include rupture through the hinge of the Big Bend. I suggest that accumulated stresses at the bend hinge from multiple smaller Carrizo or Mojave ruptures may be required to allow rupture through the bend — a concept consistent with paleoseismic observations. This study may contribute to understanding the cyclicity of hazard associated with the southern-central SAF.

Analysis of Communication between Main Control Room Operators in Decision-making Process in Steam Generator Tube Rupture Accident

International Nuclear Information System (INIS)

Petkov, M.; Petkov, G.

2006-01-01

The paper presents an investigation results for Main Control Room operators' reliability by Performance Evaluation of Teamwork method, based on FSS-1000 training archives in KNPP in case of Steam Generator Tube Rupture accident. The advantages of operators' teamwork are shown: a) group decision-making vs. individual one: b) positive influence of crew initiated communication consisting of orders and reports that are required by instruction. (authors)

Analysis of the dynamic response of a double rupture disc assembly to simulated sodium-water reaction pressure pulses

International Nuclear Information System (INIS)

Leonard, J.R.

1980-03-01

A series of double rupture disc experiments were conducted in 1979 to evaluate the dynamic response characteristics of this pressure relief apparatus. The tests were performed in a facility with water simulating sodium and rising pressure pulses representative of the pressure increase resulting from a water/steam leak from a steam generator into sodium in the intermediate heat transport system of a breeder reactor power plant. Maximum source pressures ranged in magnitude from 50 psi to 800 psi. Dynamic response characteristics of each of the two rupture discs were similar to those observed in larger scale sodium-water experiments conducted in the Series I and Series II Large Leak Test Program at the Energy Technology Engineering Center. The SRI double rupture disc dynamic behavior was found to be consistent and amendable to modelling in the TRANSWRAP II computer code. A series of correlations which represent rupture disc buckling parameters were developed for use in the TRANSWRAP II code. The semi-empirical modeling of the rupture discs in the TRANSWRAP II code showed very good agreement with the experimental results

ARTIST: An International Project Investigating Aerosol Retention in a Ruptured Steam Generator

International Nuclear Information System (INIS)

Guentay, S.; Dehbi, A.; Suckow, D.; Birchley, J.

2002-01-01

Steam generator tube ruptures (SGTR) with a concurrent stuck open safety relief valve are counted among the risk dominant accident sequences because of the potential for radioactive products to bypass the containment. Owing to the absence of relevant empirical data and the complexity of the geometry and controlling processes, the aerosol removal in the steam generator (SG) tubes and in the secondary side is not well understood. Therefore, little or no credit is usually taken for aerosol retention due to natural processes in the various components of a SG. To help reduce the uncertainties associated with fission product release following an SGTR sequence, the Paul Scherrer Institut has initiated an international experimental project to be performed in the ARTIST (AeRosol Trapping In a Steam generaTor) facility in the time period from 2002 to 2007. The ARTIST test section is a scaled model of a real SG, and is comprised of a 264-tube bundle with a maximum height of 3.8 m, as well as one full-size droplet separator and one full-size steam dryer. The ARTIST facility is capable of producing soluble and insoluble aerosols and entrain them at sonic gas flow rates (up to 0.25 kg/s, thus matching comparable values predicted by the codes. In addition, aerosols can be generated at prototypical concentrations (up to 5 g/m 3 ) and sizes (0.2-5 mm AMMD). State of the art instrumentation is used (Low-pressure impactors, photometers, on-line particle sizer, online droplet sizer, etc.). The ARTIST project will simulate the flow and retention of aerosol-borne fission products in the SG, and provide a unique database to support safety assessments and analytical models. The project is foreseen in seven phases: 1) Aerosol retention in the tube under dry secondary side conditions, 2) Aerosol retention in the near field close to break under dry conditions, 3) Aerosol retention in the bundle far field under dry conditions, 4) Aerosol retention in the separator and dryer under dry

Rupture of primigravid uterus and recurrent rupture

Directory of Open Access Journals (Sweden)

Nahreen Akhtar

2016-08-01

Full Text Available Uterine rupture is a deadly obstetrical emergency endangering the life of both mother and fetus. In Bangladesh, majority of deliveries arc attended by unskilled traditional birth attendant and maternal mortality is still quite high. It is rare Ln developed country but unfortunately it is common in a developing country like Bangladesh. We report a case history of a patient age 32yrs from Daudkandi, Comilla admitted with H/0 previous two rupture uterus and repair with no living issue. We did caesarean section at her 31+ weeks of pregnancy when she developed Jabour pain. A baby of 1.4 kg was delivered. During cesarean section, focal rupture was noted in previous scar of rupture. Unfortunately the baby expired in neonatal ICU after 36 hours.

TOWARD INDONESIAN TSUNAMI EARLY WARNING SYSTEM BY USING RAPID RUPTURE DURATIONS CALCULATION

Directory of Open Access Journals (Sweden)

M. Adlazim

2011-01-01

Full Text Available Indonesia has an Indonesian Tsunami Early Warning System (Ina-TEWS since 2008. The Ina-TEWS has used automatic processing on hypocenter; Mwp, Mw (mB and Mj. If earthquake occurred in Ocean, depth 7, then Ina-TEWS announce early warning that the earthquake can generate tsunami. However, the announcement of the Ina-TEWS is still not accuracy. Purpose of this study is to estimate earthquake rupture duration of large Indonesia earthquakes that occurred in Indian Ocean, Java, Timor Sea, Banda Sea, Arafura Sea and Pacific Ocean using a direct procedure and software developed Lomax and Michelini for rapid assessment of earthquake tsunami potential by deriving two simple measures from vertical component broadband P-wave velocity record. The first is the high-frequency apparent rupture duration, Tdur which may be related to can be related to the critical parameters rupture length (L, depth (z, and shear modulus (μ. The second is a confirmation of the earlier finding by Lomax and Michelini, namely that the rupture duration has a stronger influence to generate tsunami than Mw and Depth. We analyzed at least 510 vertical seismogram recorded by GEOFON-IA and IRIS-DMC networks. Our analysis shows that the seismic potency, LWD, which is more obviously related to capability to generate a tsunami than former. The larger Tdur the larger is the seismic potency LWD because Tdur is proportional to L/vr (with vr – rupture velocity. We also suggest that tsunami potential is not directly related to the faulting type of source and for events that have rupture duration greater than 50 s, the earthquakes generated tsunami. With available real-time seismogram data, rapid calculation, rupture duration discriminant can be completed within 3 to 8 min after the P-onset.

Complementary roles of platelets and coagulation in thrombus formation on plaques acutely ruptured by targeted ultrasound treatment: a novel intravital model

NARCIS (Netherlands)

Kuijpers, M. J. E.; Gilio, K.; Reitsma, S.; Nergiz-Unal, R.; Prinzen, L.; Heeneman, S.; Lutgens, E.; van Zandvoort, M. A. M. J.; Nieswandt, B.; Egbrink, M. G. A. Oude; Heemskerk, J. W. M.

2009-01-01

Atherothrombosis is a major cause of cardiovascular events. However, animal models to study this process are scarce. We describe the first murine model of acute thrombus formation upon plaque rupture to study atherothrombosis by intravital fluorescence microscopy. Localized rupture of an

Component external leakage and rupture frequency estimates

International Nuclear Information System (INIS)

Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

1991-11-01

In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results

Physics of Earthquake Rupture Propagation

Science.gov (United States)

Xu, Shiqing; Fukuyama, Eiichi; Sagy, Amir; Doan, Mai-Linh

2018-05-01

A comprehensive understanding of earthquake rupture propagation requires the study of not only the sudden release of elastic strain energy during co-seismic slip, but also of other processes that operate at a variety of spatiotemporal scales. For example, the accumulation of the elastic strain energy usually takes decades to hundreds of years, and rupture propagation and termination modify the bulk properties of the surrounding medium that can influence the behavior of future earthquakes. To share recent findings in the multiscale investigation of earthquake rupture propagation, we held a session entitled "Physics of Earthquake Rupture Propagation" during the 2016 American Geophysical Union (AGU) Fall Meeting in San Francisco. The session included 46 poster and 32 oral presentations, reporting observations of natural earthquakes, numerical and experimental simulations of earthquake ruptures, and studies of earthquake fault friction. These presentations and discussions during and after the session suggested a need to document more formally the research findings, particularly new observations and views different from conventional ones, complexities in fault zone properties and loading conditions, the diversity of fault slip modes and their interactions, the evaluation of observational and model uncertainties, and comparison between empirical and physics-based models. Therefore, we organize this Special Issue (SI) of Tectonophysics under the same title as our AGU session, hoping to inspire future investigations. Eighteen articles (marked with "this issue") are included in this SI and grouped into the following six categories.

Shared and Distinct Rupture Discriminants of Small and Large Intracranial Aneurysms.

Science.gov (United States)

Varble, Nicole; Tutino, Vincent M; Yu, Jihnhee; Sonig, Ashish; Siddiqui, Adnan H; Davies, Jason M; Meng, Hui

2018-04-01

Many ruptured intracranial aneurysms (IAs) are small. Clinical presentations suggest that small and large IAs could have different phenotypes. It is unknown if small and large IAs have different characteristics that discriminate rupture. We analyzed morphological, hemodynamic, and clinical parameters of 413 retrospectively collected IAs (training cohort; 102 ruptured IAs). Hierarchal cluster analysis was performed to determine a size cutoff to dichotomize the IA population into small and large IAs. We applied multivariate logistic regression to build rupture discrimination models for small IAs, large IAs, and an aggregation of all IAs. We validated the ability of these 3 models to predict rupture status in a second, independently collected cohort of 129 IAs (testing cohort; 14 ruptured IAs). Hierarchal cluster analysis in the training cohort confirmed that small and large IAs are best separated at 5 mm based on morphological and hemodynamic features (area under the curve=0.81). For small IAs (IAs (area under the curve=0.84; 95% confidence interval, 0.78-0.88), whereas for large IAs (≥5 mm), the model included undulation index, low wall shear stress, previous subarachnoid hemorrhage, and IA location (area under the curve=0.87; 95% confidence interval, 0.82-0.93). The model for the aggregated training cohort retained all the parameters in the size-dichotomized models. Results in the testing cohort showed that the size-dichotomized rupture discrimination model had higher sensitivity (64% versus 29%) and accuracy (77% versus 74%), marginally higher area under the curve (0.75; 95% confidence interval, 0.61-0.88 versus 0.67; 95% confidence interval, 0.52-0.82), and similar specificity (78% versus 80%) compared with the aggregate-based model. Small (IAs have different hemodynamic and clinical, but not morphological, rupture discriminants. Size-dichotomized rupture discrimination models performed better than the aggregate model. © 2018 American Heart Association, Inc.

Microstructural Evolution and Creep-Rupture Behavior of Fusion Welds Involving Alloys for Advanced Ultrasupercritical Power Generation

Science.gov (United States)

Bechetti, Daniel H., Jr.

Projections for large increases in the global demand for electric power produced by the burning of fossil fuels, in combination with growing environmental concerns surrounding these fuel sources, have sparked initiatives in the United States, Europe, and Asia aimed at developing a new generation of coal fired power plant, termed Advanced Ultrasupercritical (A-USC). These plants are slated to operate at higher steam temperatures and pressures than current generation plants, and in so doing will offer increased process cycle efficiency and reduced greenhouse gas emissions. Several gamma' precipitation strengthened Ni-based superalloys have been identified as candidates for the hottest sections of these plants, but the microstructural instability and poor creep behavior (compared to wrought products) of fusion welds involving these alloys present significant hurdles to their implementation and a gap in knowledge that must be addressed. In this work, creep testing and in-depth microstructural characterization have been used to provide insight into the long-term performance of these alloys. First, an investigation of the weld metal microstructural evolution as it relates to creep strength reductions in A-USC alloys INCONELRTM 740, NIMONICRTM 263 (INCONEL and NIMONIC are registered trademarks of Special Metals Corporation), and HaynesRTM 282RTM (Haynes and 282 are registered trademarks of Haynes International) was performed. gamma'-precipitate free zones were identified in two of these three alloys, and their development was linked to the evolution of phases that precipitate at the expense of gamma'. Alloy 282 was shown to avoid precipitate free zone formation because the precipitates that form during long term aging in this alloy are poor in the gamma'-forming elements. Next, the microstructural evolution of INCONELRTM 740H (a compositional variant of alloy 740) during creep was investigated. Gleeble-based interrupted creep and creep-rupture testing was used to

A Combined Experimental and Numerical Modeling Study of the Deformation and Rupture of Axisymmetric Liquid Bridges under Coaxial Stretching.

Science.gov (United States)

Zhuang, Jinda; Ju, Y Sungtaek

2015-09-22

The deformation and rupture of axisymmetric liquid bridges being stretched between two fully wetted coaxial disks are studied experimentally and theoretically. We numerically solve the time-dependent Navier-Stokes equations while tracking the deformation of the liquid-air interface using the arbitrary Lagrangian-Eulerian (ALE) moving mesh method to fully account for the effects of inertia and viscous forces on bridge dynamics. The effects of the stretching velocity, liquid properties, and liquid volume on the dynamics of liquid bridges are systematically investigated to provide direct experimental validation of our numerical model for stretching velocities as high as 3 m/s. The Ohnesorge number (Oh) of liquid bridges is a primary factor governing the dynamics of liquid bridge rupture, especially the dependence of the rupture distance on the stretching velocity. The rupture distance generally increases with the stretching velocity, far in excess of the static stability limit. For bridges with low Ohnesorge numbers, however, the rupture distance stay nearly constant or decreases with the stretching velocity within certain velocity windows due to the relative rupture position switching and the thread shape change. Our work provides an experimentally validated modeling approach and experimental data to help establish foundation for systematic further studies and applications of liquid bridges.

Investigating the Physics Behind VLFEs and LFEs: Analysis Based on Dynamic Rupture Models with Ductile-like Friction

Science.gov (United States)

Wu, B.; Oglesby, D. D.; Ghosh, A.; LI, B.

2017-12-01

Very low frequency earthquakes (VLFE) and low frequency earthquakes (LFE) are two main types of seismic signal that are observed during slow earthquakes. These phenomena differ from standard ("fast") earthquakes in many ways. In contrast to seismic signals generated by standard earthquakes, these two types of signal lack energy at higher frequencies, and have very low stress drops of around 10 kPa. In addition, the Moment-Duration scaling relationship shown by VLFEs and LFEs is linear(M T) instead of M T^3 for regular earthquakes. However, if investigated separately over a small range magnitudes and durations, the scaling relationship for each is somewhat closer to M T^3, not M T. The physical mechanism of VLFEs and LFEs is still not clear, although some models have explored this issue [e.g., Gomberg, 2016b]. Here we investigate the behavior of dynamic rupture models with a ductile-like viscous frictional property [Ando et al., 2010; Nakata et al., 2011; Ando et al., 2012] on a single patch. In the model's framework, VLFE source patches are characterized by a high viscous damping term η and a larger area( 25km^2), while sources that approach LFE properties have a low viscous damping term η and smaller patch area(<0.5km^2). Using both analytical and numerical analyses, we show how and why this model may help to explain current observations. This model supports the idea that VLFEs and LFEs are distinct events, possibly rupturing distinct patches with their own stress dynamics [Hutchison and Ghosh, 2016]. The model also makes predictions that can be tested in future observational experiments.

Dynamic Models of Earthquake Rupture along branch faults of the Eastern San Gorgonio Pass Region in CA using Complex Fault Structure

Science.gov (United States)

Douilly, R.; Oglesby, D. D.; Cooke, M. L.; Beyer, J. L.

2017-12-01

Compilation of geomorphic and paleoseismic data have illustrated that the right-lateral Coachella segment of the southern San Andreas Fault is past its average recurrence time period. On its western edge, this fault segment is split into two branches: the Mission Creek strand, and the Banning fault strand, of the San Andreas. Depending on how rupture propagates through this region, there is the possibility of a through-going rupture that could lead to the channeling of damaging seismic energy into the Los Angeles Basin. The fault structures and rupture scenarios on these two strands are potentially very different, so it is important to determine which strand is a more likely rupture path, and under which circumstances rupture will take either one. In this study, we focus on the effect of different assumptions about fault geometry and stress pattern on the rupture process to test those scenarios and thus investigate the most likely path of a rupture that starts on the Coachella segment. We consider two types of fault geometry based on the SCEC Community Fault Model and create a 3D finite element mesh. These two meshes are then incorporated into the finite element method code FaultMod to compute a physical model for the rupture dynamics. We use the slip-weakening friction law, and we consider different assumptions of background stress such as constant tractions, regional stress regimes of different orientations, heterogeneous off-fault stresses and the results of long-term stressing rates from quasi-static crustal deformation models that consider time since last event on each fault segment. Both the constant and regional stress distribution show that it is more likely for the rupture to branch from the Coachella segment to the Mission Creek compared to the Banning fault segment. For the regional stress distribution, we encounter cases of super-shear rupture for one type of fault geometry and sub-shear rupture for the other one. The fault connectivity at this branch

Dynamic Rupture Benchmarking of the ADER-DG Method

Science.gov (United States)

Gabriel, Alice; Pelties, Christian

2013-04-01

We will verify the arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) method in various test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite (Harris et al. 2009). The ADER-DG scheme is able to solve the spontaneous rupture problem with high-order accuracy in space and time on three-dimensional unstructured tetrahedral meshes. Strong mesh coarsening or refinement at areas of interest can be applied to keep the computational costs feasible. Moreover, the method does not generate spurious high-frequency contributions in the slip rate spectra and therefore does not require any artificial damping as demonstrated in previous presentations and publications (Pelties et al. 2010 and 2012). We will show that the mentioned features hold also for more advanced setups as e.g. a branching fault system, heterogeneous background stresses and bimaterial faults. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies. References: Harris, R.A., M. Barall, R. Archuleta, B. Aagaard, J.-P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, E. Dunham, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton, The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, vol. 80, no. 1, pages 119-126, 2009 Pelties, C., J. de la Puente, and M. Kaeser, Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method, AGU 2010 Fall Meeting, abstract #S21C-2068 Pelties, C., J. de la Puente, J.-P. Ampuero, G. Brietzke, and M. Kaeser, Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, JGR. - Solid Earth, VOL. 117, B02309, 2012

Towards continuum models of lateral rupture propagation in a segmented megathrust

Science.gov (United States)

Pranger, C. C.; van Dinther, Y.; Le Pourhiet, L.; May, D.; Gerya, T.

2015-12-01

At subduction megathrusts, propagation of large ruptures may be confined between the up-dip and down-dip limits of the seismogenic zone. This opens a primary role for lateral rupture dimensions to control the magnitude and severity of megathrust earthquakes. The goal of this study is to improve our understanding of the ways in which the inherent variability of the subduction interface may influence the degree of interseismic locking, and the propensity of a rupture to propagate over regions of variable slip potential. We focus in particular on the roughness of the incoming seafloor, which we expect to be of primary importance. The global absence of a historic record sufficiently long to base risk assessment on, makes us rely on numerical modelling as a way to extend our understanding of the spatio-temporal occurrence of earthquakes. However, the complex interaction of the subduction stress environment, the variability of the subduction interface, and the structure and deformation of the crustal wedge has made it very difficult to construct comprehensive numerical models of megathrust segmentation. We intend to develop and exploit the power of a plastic 3D continuum representation of the subduction megathrust, as well as off-megathrust faulting to model the long-term tectonic build-up of stresses, and their sudden seismic release. The sheer size of the 3D problem, and the time scales covering those of tectonics as well as seismology, force us to explore efficient and accurate physical and numerical techniques. So far, we have focused our efforts on developing a staggered grid finite difference code that makes use of the PETSc library for massively parallel computing. The code incorporates a newly developed automatic discretization algorithm, which enables it to handle a wide variety of equations with relative ease. What remains now is combining the physics that act on the different spatial and temporal scales. To this end we explore new constitutive models that

Calculation of craters resulting from impact rupture of rock mass using pulse hydrodynamic problem formulation

Science.gov (United States)

Gorodilov, LV; Rasputina, TB

2018-03-01

A liquid–solid hydrodynamic model is used to determine shapes and sizes of craters generated by impact rupture of rocks. Near the impact location, rock is modeled by an ideal incompressible liquid, in the distance—by an absolute solid. The calculated data are compared with the experimental results obtained under impact treatment of marble by a wedge-shaped tool.

Simulating Earthquake Rupture and Off-Fault Fracture Response: Application to the Safety Assessment of the Swedish Nuclear Waste Repository

KAUST Repository

Falth, B.

2014-12-09

To assess the long-term safety of a deep repository of spent nuclear fuel, upper bound estimates of seismically induced secondary fracture shear displacements are needed. For this purpose, we analyze a model including an earthquake fault, which is surrounded by a number of smaller discontinuities representing fractures on which secondary displacements may be induced. Initial stresses are applied and a rupture is initiated at a predefined hypocenter and propagated at a specified rupture speed. During rupture we monitor shear displacements taking place on the nearby fracture planes in response to static as well as dynamic effects. As a numerical tool, we use the 3Dimensional Distinct Element Code (3DEC) because it has the capability to handle numerous discontinuities with different orientations and at different locations simultaneously. In tests performed to benchmark the capability of our method to generate and propagate seismic waves, 3DEC generates results in good agreement with results from both Stokes solution and the Compsyn code package. In a preliminary application of our method to the nuclear waste repository site at Forsmark, southern Sweden, we assume end-glacial stress conditions and rupture on a shallow, gently dipping, highly prestressed fault with low residual strength. The rupture generates nearly complete stress drop and an M-w 5.6 event on the 12 km(2) rupture area. Of the 1584 secondary fractures (150 m radius), with a wide range of orientations and locations relative to the fault, a majority move less than 5 mm. The maximum shear displacement is some tens of millimeters at 200 m fault-fracture distance.

Break size effect on the transient thermal-hydraulic behavior during the steam generator tube rupture accident

International Nuclear Information System (INIS)

Kang, K.H.; Park, H.S.; Cho, S.; Choi, N.H.; Chu, I.C.; Yun, B.J.; Kim, K.D.; Kim, Y.S.; Baek, W.P.; Choi, K.Y.

2011-01-01

In order to simulate the SGTR accident of the APR1400, integral effect tests were performed by simulating a double-ended rupture of a single and five U-tubes. Following the reactor trip, the primary system pressure decreased and the secondary system pressure increased until the MSSVs was opened to reduce the secondary system pressure. Break area affected the timings of the major events observed in the tests. Less heat transfer to the secondary side caused by earlier actuation of the safety injection pumps had more influence on the secondary pressure of the affected steam generator than the break flow. (author)

Influence of hemodynamic factors on rupture of intracranial aneurysms: patient-specific 3D mirror aneurysms model computational fluid dynamics simulation.

Science.gov (United States)

Lu, G; Huang, L; Zhang, X L; Wang, S Z; Hong, Y; Hu, Z; Geng, D Y

2011-08-01

Hemodynamics factors play an important role in the rupture of cerebral aneurysms. The purpose of this study was to evaluate the impact of hemodynamic factors on the rupture of the MANs with 3D reconstruction model CFD simulation. RDSA was performed in 9 pairs of intracranial MANs. Each pair was divided into ruptured and unruptured groups. The hemodynamic factors of the aneurysms and their parent arteries were compared. There was a significant difference in the WSS at peak systole between the regions of the aneurysms and their parent arteries in the ruptured group (ie, 6.49 ± 3.48 Pa versus 8.78 ± 3.57 Pa, P =.015) but not in the unruptured group (ie, 9.80 ± 4.12 Pa versus 10.17 ± 7.48 Pa, P =.678). The proportion of the low WSS area to the whole area of the aneurysms was 12.20 ± 18.08% in the ruptured group and 3.96 ± 6.91% in the unruptured group; the difference between the 2 groups was statistically significant (P =.015). The OSI was 0.0879 ± 0.0764 in the ruptured group, which was significantly higher than that of the unruptured group (ie, 0.0183 ± 0.0191, P =.008). MANs may be a useful disease model to investigate possible causes linked to ruptured aneurysms. The ruptured aneurysms manifested lower WSS compared with their parent arteries, a higher proportion of the low WSS area to the whole area of aneurysm, and higher OSI compared with the unruptured aneurysms.

Characterize kinematic rupture history of large earthquakes with Multiple Haskell sources

Science.gov (United States)

Jia, Z.; Zhan, Z.

2017-12-01

Earthquakes are often regarded as continuous rupture along a single fault, but the occurrence of complex large events involving multiple faults and dynamic triggering challenges this view. Such rupture complexities cause difficulties in existing finite fault inversion algorithms, because they rely on specific parameterizations and regularizations to obtain physically meaningful solutions. Furthermore, it is difficult to assess reliability and uncertainty of obtained rupture models. Here we develop a Multi-Haskell Source (MHS) method to estimate rupture process of large earthquakes as a series of sub-events of varying location, timing and directivity. Each sub-event is characterized by a Haskell rupture model with uniform dislocation and constant unilateral rupture velocity. This flexible yet simple source parameterization allows us to constrain first-order rupture complexity of large earthquakes robustly. Additionally, relatively few parameters in the inverse problem yields improved uncertainty analysis based on Markov chain Monte Carlo sampling in a Bayesian framework. Synthetic tests and application of MHS method on real earthquakes show that our method can capture major features of large earthquake rupture process, and provide information for more detailed rupture history analysis.

Mechanical testing of newly developed biomaterial designed for intra-articular reinforcement of partially ruptured cranial cruciate ligament: ex vivo pig model

Directory of Open Access Journals (Sweden)

Petra Fedorová

2014-01-01

Full Text Available The study deals with mechanical testing of newly developed material polyethylene terephtalate coated with polycaprolactone nanofibers in combination with biodagradable Hexalon ACL/PCL screws as a new possibility of intra-articular reinforcement of partially ruptured cranial cruciate ligament. Four groups of ex vivo models of pig stifle joints were prepared and tested: a model with intact CCL (group 1, a model with partial CCL rupture (group 2, a model with CCL rupture stabilized with 7 mm Mersilene® strip (group 3, and a model with CCL rupture stabilized with 5 mm PET/PCL biomaterial strip (group 4. The models were loaded in the standing angle of 100° and the maximum load (N and the shift (mm were monitored. The mean maximum peak power and the shift were 1266.0 ± 146.9 N and 13.7 ± 2.5 mm for group 1, and 1164.7 ± 228.2 N and 1 6.8 ± 3.3 mm for group 2, respectively. In all cases after reaching the maximum load, a tibial fracture occurred but never a CCL rupture. In groups 3 and 4, the initial fixation failure occurred in the mean values of 375.7 ± 81.5 and 360.4 ± 52.0 N, respectively, and with a bigger shift of 52.3 ± 11.9 mm and 39.4 ± 14.6 mm, respectively, compared to group 1. A critical point of failure was the anchoring in the bone. It can be concluded that the PET/PCL substitute in the ex vivo model has mechanically comparable properties with the clinically used Mersilene®, and based on its proven ability to carry stem cells it could be appropriate for partially ruptured CCL protection.

Rupture disc

International Nuclear Information System (INIS)

Newton, R.G.

1977-01-01

The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough

Large-leak sodium-water reaction analysis for steam generators

International Nuclear Information System (INIS)

Sakano, K.; Shindo, Y.; Hori, M.

1975-01-01

The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

Large-leak sodium-water reaction analysis for steam generators

Energy Technology Data Exchange (ETDEWEB)

Sakano, K; Shindo, Y; Hori, M

1975-07-01

The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

Complementary Ruptures of Surface Ruptures and Deep Asperity during the 2014 Northern Nagano, Japan, Earthquake (MW 6.3)

Science.gov (United States)

Asano, K.; Iwata, T.; Kubo, H.

2015-12-01

A thrust earthquake of MW 6.3 occurred along the northern part of the Itoigawa-Shizuoka Tectonic Line (ISTL) in the northern Nagano prefecture, central Japan, on November 22, 2014. This event was reported to be related to an active fault, the Kamishiro fault belonging to the ISTL (e.g., HERP, 2014). The surface rupture is observed along the Kamishiro fault (e.g., Lin et al., 2015; Okada et al., 2015). We estimated the kinematic source rupture process of this earthquake through the multiple time-window linear waveform inversion method (Hartzell and Heaton, 1983). We used velocity waveforms in 0.05-1 Hz from 12 strong motion stations of K-NET, KiK-net (NIED), JMA, and Nagano prefecture (SK-net, ERI). In order to enhance the reliability in Green's functions, we assumed one-dimensional velocity structure models different for the different stations, which were extracted from the nation-wide three-dimensional velocity structure model, Japan Integrated Velocity Structure Model (JIVSM, Koketsu et al., 2012). Considering the spatial distribution of aftershocks (Sakai et al., 2015) and surface ruptures, the assumed fault model consisted of two dip-bending fault segments with different dip angles between the northern and southern segments. The total length and width of the fault plane is 20 km and 13 km, relatively, and the fault model is divided into 260 subfaults of 1 km × 1 km in space and six smoothed ramp functions in time. An asperity or large slip area with a peak slip of 1.9 m was estimated in the lower plane of the northern segment in the approximate depth range of 4 to 8 km. The depth extent of this asperity is consistent with the seismogenic zone revealed by past studies (e.g., Panayotopoulos et al., 2014). In contrast, the slip in the southern segment is relatively concentrated in the shallow portion of the segment where the surface ruptures were found along the Kamishiro fault. The overall spatial rupture pattern of the source fault, in which the deep asperity

Shigella subverts the host recycling compartment to rupture its vacuole.

Science.gov (United States)

Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

2014-10-08

Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. Copyright © 2014 Elsevier Inc. All rights reserved.

Simulation of a main steam line break with steam generator tube rupture using trace

Energy Technology Data Exchange (ETDEWEB)

Gallardo, S.; Querol, A.; Verdu, G. [Departamento de Ingenieria Quimica Y Nuclear, Universitat Politecnica de Valencia, Camino de Vera s/n, 46022, Valencia (Spain)

2012-07-01

A simulation of the OECD/NEA ROSA-2 Project Test 5 was made with the thermal-hydraulic code TRACE5. Test 5 performed in the Large Scale Test Facility (LSTF) reproduced a Main Steam Line Break (MSLB) with a Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR). The result of these simultaneous breaks is a depressurization in the secondary and primary system in loop B because both systems are connected through the SGTR. Good approximation was obtained between TRACE5 results and experimental data. TRACE5 reproduces qualitatively the phenomena that occur in this transient: primary pressure falls after the break, stagnation of the pressure after the opening of the relief valve of the intact steam generator, the pressure falls after the two openings of the PORV and the recovery of the liquid level in the pressurizer after each closure of the PORV. Furthermore, a sensitivity analysis has been performed to know the effect of varying the High Pressure Injection (HPI) flow rate in both loops on the system pressures evolution. (authors)

Application of dynamic probabilistic safety assessment approach for accident sequence precursor analysis: Case study for steam generator tube rupture

Energy Technology Data Exchange (ETDEWEB)

Lee, Han Sul; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Kim, Tae Wan [Incheon National University, Incheon (Korea, Republic of)

2017-03-15

The purpose of this research is to introduce the technical standard of accident sequence precursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safety assessment (D-PSA) approach. The D-PSA approach can aid in the determination of high-risk/low-frequency accident scenarios from all potential scenarios. It can also be used to investigate the dynamic interaction between the physical state and the actions of the operator in an accident situation for risk quantification. This approach lends significant potential for safety analysis. Furthermore, the D-PSA approach provides a more realistic risk assessment by minimizing assumptions used in the conventional PSA model so-called the static-PSA model, which are relatively static in comparison. We performed risk quantification of a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET) methodology, which is the most widely used methodology in D-PSA. The risk quantification results of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendations for using D-PSA are described in order to provide a technical perspective.

Application of dynamic probabilistic safety assessment approach for accident sequence precursor analysis: Case study for steam generator tube rupture

International Nuclear Information System (INIS)

Lee, Han Sul; Heo, Gyun Young; Kim, Tae Wan

2017-01-01

The purpose of this research is to introduce the technical standard of accident sequence precursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safety assessment (D-PSA) approach. The D-PSA approach can aid in the determination of high-risk/low-frequency accident scenarios from all potential scenarios. It can also be used to investigate the dynamic interaction between the physical state and the actions of the operator in an accident situation for risk quantification. This approach lends significant potential for safety analysis. Furthermore, the D-PSA approach provides a more realistic risk assessment by minimizing assumptions used in the conventional PSA model so-called the static-PSA model, which are relatively static in comparison. We performed risk quantification of a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET) methodology, which is the most widely used methodology in D-PSA. The risk quantification results of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendations for using D-PSA are described in order to provide a technical perspective

Analysis of Fan Waves in a Laboratory Model Simulating the Propagation of Shear Ruptures in Rocks

Science.gov (United States)

Tarasov, B. G.; Sadovskii, V. M.; Sadovskaya, O. V.

2017-12-01

The fan-shaped mechanism of rotational motion transmission in a system of elastically bonded slabs on flat surface, simulating the propagation of shear ruptures in super brittle rocks, is analyzed. Such ruptures appear in the Earth's crust at seismogenic depths. They propagate due to the nucleation of oblique tensile microcracks, leading to the formation of a fan domino-structure in the rupture head. A laboratory physical model was created which demonstrates the process of fan-structure wave propagation. Equations of the dynamics of rotational motion of slabs as a mechanical system with a finite number of degrees of freedom are obtained. Based on the Merson method of solving the Cauchy problem for systems of ordinary differential equations, the computational algorithm taking into account contact interaction of slabs is developed. Within the framework of a simplified mathematical model of dynamic behavior of a fan-shaped system in the approximation of a continuous medium, the approximate estimates of the length of a fan depending on the velocity of its motion are obtained. It is shown that in the absence of friction a fan can move with any velocity that does not exceed the critical value, which depends on the size, the moment of inertia of slabs, the initial angle and the elasticity coefficient of bonds. In the presence of friction a fan stops. On the basis of discrete and continuous models, the main qualitative features of the behavior of a fan-structure moving under the action of applied tangential forces, whose values in a laboratory physical model are regulated by a change in the inclination angle of the rupture plane, are analyzed. Comparison of computations and laboratory measurements and observations shows good correspondence between the results.

Creep-rupture correlations for type 304 stainless steel heat 9T2796

International Nuclear Information System (INIS)

Swindeman, R.W.

1975-01-01

Creep-rupture data are presented for a reference heat of type 304 stainless steel tested at temperatures between 482 and 816 0 C (900-1500 0 F) and for times to 10,000 hr. The ability of several popular time-temperature parameters to correlate the rupture data is examined, and it shows that the Orr-Sherby-Dorn parameter provides a slightly better fit to the data than the Larson-Miller, Manson-Haferd, and Manson-Succop parameters. An alternative model is developed, based on the Barrett-Ardell-Sherby parameter, which makes use of modulus-compensated true stresses. These stresses are approximated on the basis of the strain about halfway through the test. Although the parameter does not fit the data quite as well as the Orr-Sherby-Dorn parameter, the activation energy associated with the parameter approaches the value expected for solute element diffusion in stainless steel. In the very high-stress region the master curve generated by the parameter is used to examine the interface between the results of tensile tests, described in terms of the Voce equation, and the creep-rupture tests. The tensile data can be correlated with the Barrett-Ardel-Sherby parameter when the tensile testing conditions are such that rupture is initiated by grain boundary failures

Dynamic fracture network around faults: implications for earthquake ruptures, ground motion and energy budget

Science.gov (United States)

Okubo, K.; Bhat, H. S.; Rougier, E.; Lei, Z.; Knight, E. E.; Klinger, Y.

2017-12-01

Numerous studies have suggested that spontaneous earthquake ruptures can dynamically induce failure in secondary fracture network, regarded as damage zone around faults. The feedbacks of such fracture network play a crucial role in earthquake rupture, its radiated wave field and the total energy budget. A novel numerical modeling tool based on the combined finite-discrete element method (FDEM), which accounts for the main rupture propagation and nucleation/propagation of secondary cracks, was used to quantify the evolution of the fracture network and evaluate its effects on the main rupture and its associated radiation. The simulations were performed with the FDEM-based software tool, Hybrid Optimization Software Suite (HOSSedu) developed by Los Alamos National Laboratory. We first modeled an earthquake rupture on a planar strike-slip fault surrounded by a brittle medium where secondary cracks can be nucleated/activated by the earthquake rupture. We show that the secondary cracks are dynamically generated dominantly on the extensional side of the fault, mainly behind the rupture front, and it forms an intricate network of fractures in the damage zone. The rupture velocity thereby significantly decreases, by 10 to 20 percent, while the supershear transition length increases in comparison to the one with purely elastic medium. It is also observed that the high-frequency component (10 to 100 Hz) of the near-field ground acceleration is enhanced by the dynamically activated fracture network, consistent with field observations. We then conducted the case study in depth with various sets of initial stress state, and friction properties, to investigate the evolution of damage zone. We show that the width of damage zone decreases in depth, forming "flower-like" structure as the characteristic slip distance in linear slip-weakening law, or the fracture energy on the fault, is kept constant with depth. Finally, we compared the fracture energy on the fault to the energy

A global search inversion for earthquake kinematic rupture history: Application to the 2000 western Tottori, Japan earthquake

Science.gov (United States)

Piatanesi, A.; Cirella, A.; Spudich, P.; Cocco, M.

2007-01-01

We present a two-stage nonlinear technique to invert strong motions records and geodetic data to retrieve the rupture history of an earthquake on a finite fault. To account for the actual rupture complexity, the fault parameters are spatially variable peak slip velocity, slip direction, rupture time and risetime. The unknown parameters are given at the nodes of the subfaults, whereas the parameters within a subfault are allowed to vary through a bilinear interpolation of the nodal values. The forward modeling is performed with a discrete wave number technique, whose Green's functions include the complete response of the vertically varying Earth structure. During the first stage, an algorithm based on the heat-bath simulated annealing generates an ensemble of models that efficiently sample the good data-fitting regions of parameter space. In the second stage (appraisal), the algorithm performs a statistical analysis of the model ensemble and computes a weighted mean model and its standard deviation. This technique, rather than simply looking at the best model, extracts the most stable features of the earthquake rupture that are consistent with the data and gives an estimate of the variability of each model parameter. We present some synthetic tests to show the effectiveness of the method and its robustness to uncertainty of the adopted crustal model. Finally, we apply this inverse technique to the well recorded 2000 western Tottori, Japan, earthquake (Mw 6.6); we confirm that the rupture process is characterized by large slip (3-4 m) at very shallow depths but, differently from previous studies, we imaged a new slip patch (2-2.5 m) located deeper, between 14 and 18 km depth. Copyright 2007 by the American Geophysical Union.

The transition of dynamic rupture styles in elastic media under velocity-weakening friction

KAUST Repository

Gabriel, A.-A.

2012-09-01

Although kinematic earthquake source inversions show dominantly pulse-like subshear rupture behavior, seismological observations, laboratory experiments and theoretical models indicate that earthquakes can operate with different rupture styles: either as pulses or cracks, that propagate at subshear or supershear speeds. The determination of rupture style and speed has important implications for ground motions and may inform about the state of stress and strength of active fault zones. We conduct 2D in-plane dynamic rupture simulations with a spectral element method to investigate the diversity of rupture styles on faults governed by velocity-and-state-dependent friction with dramatic velocity-weakening at high slip rate. Our rupture models are governed by uniform initial stresses, and are artificially initiated. We identify the conditions that lead to different rupture styles by investigating the transitions between decaying, steady state and growing pulses, cracks, sub-shear and super-shear ruptures as a function of background stress, nucleation size and characteristic velocity at the onset of severe weakening. Our models show that small changes of background stress or nucleation size may lead to dramatic changes of rupture style. We characterize the asymptotic properties of steady state and self-similar pulses as a function of background stress. We show that an earthquake may not be restricted to a single rupture style, but that complex rupture patterns may emerge that consist of multiple rupture fronts, possibly involving different styles and back-propagating fronts. We also demonstrate the possibility of a super-shear transition for pulse-like ruptures. Finally, we draw connections between our findings and recent seismological observations.

The transition of dynamic rupture styles in elastic media under velocity-weakening friction

KAUST Repository

Gabriel, A.-A.; Ampuero, J.-P.; Dalguer, L. A.; Mai, Paul Martin

2012-01-01

Although kinematic earthquake source inversions show dominantly pulse-like subshear rupture behavior, seismological observations, laboratory experiments and theoretical models indicate that earthquakes can operate with different rupture styles: either as pulses or cracks, that propagate at subshear or supershear speeds. The determination of rupture style and speed has important implications for ground motions and may inform about the state of stress and strength of active fault zones. We conduct 2D in-plane dynamic rupture simulations with a spectral element method to investigate the diversity of rupture styles on faults governed by velocity-and-state-dependent friction with dramatic velocity-weakening at high slip rate. Our rupture models are governed by uniform initial stresses, and are artificially initiated. We identify the conditions that lead to different rupture styles by investigating the transitions between decaying, steady state and growing pulses, cracks, sub-shear and super-shear ruptures as a function of background stress, nucleation size and characteristic velocity at the onset of severe weakening. Our models show that small changes of background stress or nucleation size may lead to dramatic changes of rupture style. We characterize the asymptotic properties of steady state and self-similar pulses as a function of background stress. We show that an earthquake may not be restricted to a single rupture style, but that complex rupture patterns may emerge that consist of multiple rupture fronts, possibly involving different styles and back-propagating fronts. We also demonstrate the possibility of a super-shear transition for pulse-like ruptures. Finally, we draw connections between our findings and recent seismological observations.

Estimation of time to rupture in a fire using 6FIRE, a lumped parameter UF6 cylinder transient heat transfer/stress analysis model

International Nuclear Information System (INIS)

Williams, W.R.; Anderson, J.C.

1995-01-01

The transportation of UF 6 is subject to regulations requiring the evaluation of packaging under a sequence of hypothetical accident conditions including exposure to a 30-min 800 degree C (1475 degree F) fire [10 CFR 71.73(c)(3)]. An issue of continuing interest is whether bare cylinders can withstand such a fire without rupturing. To address this issue, a lumped parameter heat transfer/stress analysis model (6FIRE) has been developed to simulate heating to the point of rupture of a cylinder containing UF 6 when it is exposed to a fire. The model is described, then estimates of time to rupture are presented for various cylinder types, fire temperatures, and fill conditions. An assessment of the quantity of UF 6 released from containment after rupture is also presented. Further documentation of the model is referenced

Ruptured eardrum

Science.gov (United States)

... eardrum ruptures. After the rupture, you may have: Drainage from the ear (drainage may be clear, pus, or bloody) Ear noise/ ... doctor to see the eardrum. Audiology testing can measure how much hearing has been lost. Treatment You ...

Metrics for comparing dynamic earthquake rupture simulations

Science.gov (United States)

Barall, Michael; Harris, Ruth A.

2014-01-01

Earthquakes are complex events that involve a myriad of interactions among multiple geologic features and processes. One of the tools that is available to assist with their study is computer simulation, particularly dynamic rupture simulation. A dynamic rupture simulation is a numerical model of the physical processes that occur during an earthquake. Starting with the fault geometry, friction constitutive law, initial stress conditions, and assumptions about the condition and response of the near‐fault rocks, a dynamic earthquake rupture simulation calculates the evolution of fault slip and stress over time as part of the elastodynamic numerical solution (Ⓔ see the simulation description in the electronic supplement to this article). The complexity of the computations in a dynamic rupture simulation make it challenging to verify that the computer code is operating as intended, because there are no exact analytic solutions against which these codes’ results can be directly compared. One approach for checking if dynamic rupture computer codes are working satisfactorily is to compare each code’s results with the results of other dynamic rupture codes running the same earthquake simulation benchmark. To perform such a comparison consistently, it is necessary to have quantitative metrics. In this paper, we present a new method for quantitatively comparing the results of dynamic earthquake rupture computer simulation codes.

Analysis of steam-generator tube-rupture events combined with auxiliary-feedwater control-system failure for Three Mile Island-Unit 1 and Zion-Unit 1 pressurized water reactors

International Nuclear Information System (INIS)

Nassersharif, B.

1986-01-01

A steam-generator tube-rupture (SGTR) event combined with loss of all offsite alternating-current power and failure of the auxiliary-feedwater (AFW) control system has been investigated for the Three Mile Island-Unit 1 (TMI-1) and Zion-Unit 1 (Zion-1) pressurized water reactors. The Transient Reactor Analysis Code was used to simulate the accident sequence for each plant. The objectives of the study were to predict the plant transient response with respect to tube-rupture flow termination, extent of steam generator overfill, and thermal-hydraulic conditions in the steam lines. Two transient cases were calculated: (1) a TMI-1 SGTR and runaway-AFW transient, and (2) a Zion-1 SGTR and runaway-AFW transient. Operator actions terminated the tube-rupture flow by 1342 s (22.4 min) and 1440 s (24.0 min) for TMI-1 and Zion-1, respectively, but AFW injection was continued. The damaged steam generator (DSG) overfilled by 1273 s (21.2 min) for the TMI-1 calculation and by 1604 s (26.7 min) for the Zion-1 calculation. The DSG steam lines were completely filled by 1500 s (25 min) and 2000 s (33.3 min) for TMI-1 and Zion-1, respectively. The maximum subcooling in the steam lines was approx.63 K (approx.113 0 F) for TMI-1 and approx.44 K (approx.80 0 F) for Zion-1

Surface rupture and vertical deformation associated with 20 May 2016 M6 Petermann Ranges earthquake, Northern Territory, Australia

Science.gov (United States)

Gold, Ryan; Clark, Dan; King, Tamarah; Quigley, Mark

2017-04-01

Surface-rupturing earthquakes in stable continental regions (SCRs) occur infrequently, though when they occur in heavily populated regions the damage and loss of life can be severe (e.g., 2001 Bhuj earthquake). Quantifying the surface-rupture characteristics of these low-probability events is therefore important, both to improve understanding of the on- and off-fault deformation field near the rupture trace and to provide additional constraints on earthquake magnitude to rupture length and displacement, which are critical inputs for seismic hazard calculations. This investigation focuses on the 24 August 2016 M6.0 Petermann Ranges earthquake, Northern Territory, Australia. We use 0.3-0.5 m high-resolution optical Worldview satellite imagery to map the trace of the surface rupture associated with the earthquake. From our mapping, we are able to trace the rupture over a length of 20 km, trending NW, and exhibiting apparent north-side-up motion. To quantify the magnitude of vertical surface deformation, we use stereo Worldview images processed using NASA Ames Stereo Pipeline software to generate pre- and post-earthquake digital terrain models with a spatial resolution of 1.5 to 2 m. The surface scarp is apparent in much of the post-event digital terrain model. Initial efforts to difference the pre- and post-event digital terrain models yield noisy results, though we detect vertical deformation of 0.2 to 0.6 m over length scales of 100 m to 1 km from the mapped trace of the rupture. Ongoing efforts to remove ramps and perform spatial smoothing will improve our understanding of the extent and pattern of vertical deformation. Additionally, we will compare our results with InSAR and field measurements obtained following the earthquake.

Heterogeneous slip and rupture models of the San Andreas fault zone based upon three-dimensional earthquake tomography

Energy Technology Data Exchange (ETDEWEB)

Foxall, William [Univ. of California, Berkeley, CA (United States)

1992-11-01

Crystal fault zones exhibit spatially heterogeneous slip behavior at all scales, slip being partitioned between stable frictional sliding, or fault creep, and unstable earthquake rupture. An understanding the mechanisms underlying slip segmentation is fundamental to research into fault dynamics and the physics of earthquake generation. This thesis investigates the influence that large-scale along-strike heterogeneity in fault zone lithology has on slip segmentation. Large-scale transitions from the stable block sliding of the Central 4D Creeping Section of the San Andreas, fault to the locked 1906 and 1857 earthquake segments takes place along the Loma Prieta and Parkfield sections of the fault, respectively, the transitions being accomplished in part by the generation of earthquakes in the magnitude range 6 (Parkfield) to 7 (Loma Prieta). Information on sub-surface lithology interpreted from the Loma Prieta and Parkfield three-dimensional crustal velocity models computed by Michelini (1991) is integrated with information on slip behavior provided by the distributions of earthquakes located using, the three-dimensional models and by surface creep data to study the relationships between large-scale lithological heterogeneity and slip segmentation along these two sections of the fault zone.

On the constitutive criteria for the fault: influence of size and tensile cracks generation during rupture

International Nuclear Information System (INIS)

Riera, J.D.; Miguel, L.F.F.; Gudiel, L.A.D.

2005-01-01

In recent studies the authors consider the possibility of occurrence of tensile crack generation near the free surface during faulting. The main assumption is that the dynamic tensile stress created during the shear rupture process would be dominant over the background stress near the free-surface. The proposed model was able to simulate the mechanism of cracks developed as a flower like-structure surrounding the shear fault in the vicinity of the free surface and explain some aspects of the fracture zones found after the 2000 Tottori earthquake. The applicability of various constitutive laws for the fault employed in numerical analysis of the near source motion, such as the slip-weakening, velocity-weakening or rate- and state-dependent friction laws, were also recently discussed by the authors in connection with results of laboratory experiments on friction. In this paper, the most important conclusions of the studies outlined above are summarized by way of introduction to the numerical modeling of the region adjacent to the fault surface, which includes material nonhomogeneities as well as the possibility of generation of new tensile cracks. In the presence of fracture, both factors exert important influence on the macro constitutive laws for the fault, which relate the static (mean normal and shear stresses) with kinetic (displacements) variables, as well as with their time derivatives. By means of simulation, it is shown that the coefficients in the equation that relate the relevant variables depend on size, that is, they vary with the contact area over which stresses, displacements and velocities are averaged. Any variability in Young's modulus or mass density of the surround rock may however be neglected, the only significant random fields being those that describe friction at the interface and the specific fracture energy. (authors)

Inflammation and intracranial aneurysms: mechanisms of initiation, growth, and rupture

Directory of Open Access Journals (Sweden)

Peter S Amenta

2015-06-01

Full Text Available Outcomes following aneurysmal subarachnoid hemorrhage remain poor in many patients, despite advances in microsurgical and endovascular management. Consequently, considerable effort has been placed in determining the mechanisms of aneurysm formation, growth, and rupture. Various environmental and genetic factors are implicated as key components in the aneurysm pathogenesis. Currently, sufficient evidence exists to incriminate the inflammatory response as the common pathway leading to aneurysm generation and rupture. Central to this model is the interaction between the vessel wall and inflammatory cells. Dysfunction of the endothelium and vascular smooth muscle cells (VSMCs promotes a chronic pathological inflammatory response that progressively weakens the vessel wall. We review the literature pertaining to the cellular and chemical mechanisms of inflammation that contribute to aneurysm development. Hemodynamic stress and alterations in blood flow are discussed regarding their role in promoting chronic inflammation. Endothelial cell and VSMC dysfunction are examined concerning vascular remodeling. The contribution of inflammatory cytokines, especially tumor necrosis factor-α is illustrated. Inflammatory cell infiltration, particularly macrophage-mediated deterioration of vascular integrity, is reviewed. We discuss the inflammation as a means to determine aneurysms at greatest risk of rupture. Finally, future therapeutic implications of pharmacologic modulation of the inflammation are discussed.

Simulation of a loss of coolant accident with rupture in the steam generator hot collector

International Nuclear Information System (INIS)

1991-03-01

The Central Research Institute for Physics of the Hungarian Academy of Sciences designed and constructed the PMK-NVH test facility, a scaled down model of the WWER-440 Paks nuclear power plant. Hungary made the PMK-NVH facility available to the IAEA. The IAEA, having identified the need for experimental data due to the difficulties of building integral test facilities and the high costs of these experiments, has accepted the offer of the Hungarian Academy of Sciences and has organized three standard problem exercises. In these exercises, experimental data from the simulation of loss of coolant accidents were compared with analytical predictions of the behaviour of the facility, calculated with computer codes. The third standard problem exercise involved a test, in which the rupture was simulated to occur at the top of the hot collector of the steam generator, therefore creating a leak from primary to secondary side. Both hydroaccumulators and high pressure injection were allowed to actuate as prescribed in the actual plant. Eighteen organizations from 15 Member States took part in the exercise presenting pre-test and some post-test analyses which were discussed in a final meeting in Vienna in August, 1990. This document presents a complete overview of the third standard problem exercise, including description of the facility, the experiment, the codes and models used by the participants and a detailed intercomparison of calculated and experimental results. It is recognized that code assessment is a long process which involves many interrelated steps; therefore, no general conclusion or optimum code or best model was reached. However, the exercise was recognized as an important contributor to code validation. 42 refs, figs and tabs

Uniform California earthquake rupture forecast, version 3 (UCERF3): the time-independent model

Science.gov (United States)

Field, Edward H.; Biasi, Glenn P.; Bird, Peter; Dawson, Timothy E.; Felzer, Karen R.; Jackson, David D.; Johnson, Kaj M.; Jordan, Thomas H.; Madden, Christopher; Michael, Andrew J.; Milner, Kevin R.; Page, Morgan T.; Parsons, Thomas; Powers, Peter M.; Shaw, Bruce E.; Thatcher, Wayne R.; Weldon, Ray J.; Zeng, Yuehua; ,

2013-01-01

In this report we present the time-independent component of the Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3), which provides authoritative estimates of the magnitude, location, and time-averaged frequency of potentially damaging earthquakes in California. The primary achievements have been to relax fault segmentation assumptions and to include multifault ruptures, both limitations of the previous model (UCERF2). The rates of all earthquakes are solved for simultaneously, and from a broader range of data, using a system-level "grand inversion" that is both conceptually simple and extensible. The inverse problem is large and underdetermined, so a range of models is sampled using an efficient simulated annealing algorithm. The approach is more derivative than prescriptive (for example, magnitude-frequency distributions are no longer assumed), so new analysis tools were developed for exploring solutions. Epistemic uncertainties were also accounted for using 1,440 alternative logic tree branches, necessitating access to supercomputers. The most influential uncertainties include alternative deformation models (fault slip rates), a new smoothed seismicity algorithm, alternative values for the total rate of M≥5 events, and different scaling relationships, virtually all of which are new. As a notable first, three deformation models are based on kinematically consistent inversions of geodetic and geologic data, also providing slip-rate constraints on faults previously excluded because of lack of geologic data. The grand inversion constitutes a system-level framework for testing hypotheses and balancing the influence of different experts. For example, we demonstrate serious challenges with the Gutenberg-Richter hypothesis for individual faults. UCERF3 is still an approximation of the system, however, and the range of models is limited (for example, constrained to stay close to UCERF2). Nevertheless, UCERF3 removes the apparent UCERF2 overprediction of

Three-dimensional dynamic rupture simulation with a high-order discontinuous Galerkin method on unstructured tetrahedral meshes

KAUST Repository

Pelties, Christian

2012-02-18

Accurate and efficient numerical methods to simulate dynamic earthquake rupture and wave propagation in complex media and complex fault geometries are needed to address fundamental questions in earthquake dynamics, to integrate seismic and geodetic data into emerging approaches for dynamic source inversion, and to generate realistic physics-based earthquake scenarios for hazard assessment. Modeling of spontaneous earthquake rupture and seismic wave propagation by a high-order discontinuous Galerkin (DG) method combined with an arbitrarily high-order derivatives (ADER) time integration method was introduced in two dimensions by de la Puente et al. (2009). The ADER-DG method enables high accuracy in space and time and discretization by unstructured meshes. Here we extend this method to three-dimensional dynamic rupture problems. The high geometrical flexibility provided by the usage of tetrahedral elements and the lack of spurious mesh reflections in the ADER-DG method allows the refinement of the mesh close to the fault to model the rupture dynamics adequately while concentrating computational resources only where needed. Moreover, ADER-DG does not generate spurious high-frequency perturbations on the fault and hence does not require artificial Kelvin-Voigt damping. We verify our three-dimensional implementation by comparing results of the SCEC TPV3 test problem with two well-established numerical methods, finite differences, and spectral boundary integral. Furthermore, a convergence study is presented to demonstrate the systematic consistency of the method. To illustrate the capabilities of the high-order accurate ADER-DG scheme on unstructured meshes, we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes curved faults, fault branches, and surface topography. Copyright 2012 by the American Geophysical Union.

A two-fluid two-phase model for thermal-hydraulic analysis of a U-tube steam generator

International Nuclear Information System (INIS)

Hung, Huanjen; Chieng, Chingchang; Pei, Baushei; Wang, Songfeng

1993-01-01

The Advanced Thermal-Hydraulic Analysis Code for Nuclear Steam Generators (ATHANS) was developed on the basis of the THERMIT-UTSG computer code for U-tube steam generators. The main features of the ATHANS model are as follows: (a) the equations are solved in cylindrical coordinates, (b) the number and the arrangement of the control volumes inside the steam generator can be chosen by the user, (c) the virtual mass effect is incorporated, and (d) the conjugate gradient squared method is employed to accelerate and improve the numerical convergence. The performance of the model is successfully validated by comparison with the test data from a Westinghouse model F steam generator at the Maanshan nuclear power plant. Better agreement with the test data can be obtained by a finer grid system using a cylindrical coordinate system and the virtual mass effect. With these advanced features, ATHANS provides the basic framework for further studies on the problems of steam generators, such as analyses of secondary-side corrosion and tube ruptures

Slow rupture of frictional interfaces

Science.gov (United States)

Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

2012-02-01

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

Global catalog of earthquake rupture velocities shows anticorrelation between stress drop and rupture velocity

Science.gov (United States)

Chounet, Agnès; Vallée, Martin; Causse, Mathieu; Courboulex, Françoise

2018-05-01

Application of the SCARDEC method provides the apparent source time functions together with seismic moment, depth, and focal mechanism, for most of the recent earthquakes with magnitude larger than 5.6-6. Using this large dataset, we have developed a method to systematically invert for the rupture direction and average rupture velocity Vr, when unilateral rupture propagation dominates. The approach is applied to all the shallow (z earthquakes of the catalog over the 1992-2015 time period. After a careful validation process, rupture properties for a catalog of 96 earthquakes are obtained. The subsequent analysis of this catalog provides several insights about the seismic rupture process. We first report that up-dip ruptures are more abundant than down-dip ruptures for shallow subduction interface earthquakes, which can be understood as a consequence of the material contrast between the slab and the overriding crust. Rupture velocities, which are searched without any a-priori up to the maximal P wave velocity (6000-8000 m/s), are found between 1200 m/s and 4500 m/s. This observation indicates that no earthquakes propagate over long distances with rupture velocity approaching the P wave velocity. Among the 23 ruptures faster than 3100 m/s, we observe both documented supershear ruptures (e.g. the 2001 Kunlun earthquake), and undocumented ruptures that very likely include a supershear phase. We also find that the correlation of Vr with the source duration scaled to the seismic moment (Ts) is very weak. This directly implies that both Ts and Vr are anticorrelated with the stress drop Δσ. This result has implications for the assessment of the peak ground acceleration (PGA) variability. As shown by Causse and Song (2015), an anticorrelation between Δσ and Vr significantly reduces the predicted PGA variability, and brings it closer to the observed variability.

A Modified Split Hopkinson Pressure Bar Approach for Mimicking Dynamic Oscillatory Stress Fluctuations During Earthquake Rupture

Science.gov (United States)

Braunagel, M. J.; Griffith, W. A.

2017-12-01

Past experimental work has demonstrated that rock failure at high strain rates occurs by fragmentation rather than discrete fracture and is accompanied by a dramatic increase in rock strength. However, these observations are difficult to reconcile with the assertion that pulverized rocks in fault zones are the product of impulsive stresses during the passage of earthquake ruptures, as the distance from the principal slip zones of some pulverized rock is too great to exceed fragmentation transition. One potential explanation to this paradox that has been suggested is that repeated loading over the course of multiple earthquake ruptures may gradually reduce the pulverization threshold, in terms of both strain rate and strength. We propose that oscillatory loading during a single earthquake rupture may further lower these pulverization thresholds, and that traditional dynamic experimental approaches, such as the Split Hopkinson Pressure Bar (SHPB) wherein load is applied as a single, smooth, sinusoidal compressive wave, may not reflect natural loading conditions. To investigate the effects of oscillatory compressive loading expected during earthquake rupture propagation, we develop a controlled cyclic loading model on a SHPB apparatus utilizing two striker bars connected by an elastic spring. Unlike traditional SHPB experiments that utilize a gas gun to fire a projectile bar and generate a single compressive wave on impact with the incident bar, our modified striker bar assembly oscillates while moving down the gun barrel and generates two separate compressive pulses separated by a lag time. By modeling the modified assembly as a mass-spring-mass assembly accelerating due to the force of the released gas, we can predict the compression time of the spring upon impact and therefore the time delay between the generation of the first and second compressive waves. This allows us to predictably control load cycles with durations of only a few hundred microseconds. Initial

Effect of cold works on creep-rupture life of type 316LN stainless steel

International Nuclear Information System (INIS)

Kim, W. G.; Han, C. H.; Ryu, W. S.

2003-01-01

Effect of cold works on creep-rupture life of the cold-worked type 316LN stainless steels, which are fabricated with the various reductions ; 0%(solution annealing), 20%, 30%, 40%, and 50%, was investigated. The creep-rupture time increased gradually up to 30% reduction, but it decreased inversely over 30% reduction. The longest rupture time exhibited at cold-worked reduction of 30%. The reason for this is that fine carbide precipitates are uniformly generated in grain boundary and the dislocations are pinned in the precipitates and the dislocations are sustained for a long time at high temperature. However, it is assumed that the higher cold-work reductions over 30% lead to excessive generation of deformation faults. The SEM fractrographs of the cold-worked specimens showed dense fracture micrographs, and they did not show intergranular structures in creep fracture mode. From this result, it is believed that the cold-worked specimens were superior in creep-rupture time to solution annealed ones

Earthquake scaling laws for rupture geometry and slip heterogeneity

Science.gov (United States)

Thingbaijam, Kiran K. S.; Mai, P. Martin; Goda, Katsuichiro

2016-04-01

We analyze an extensive compilation of finite-fault rupture models to investigate earthquake scaling of source geometry and slip heterogeneity to derive new relationships for seismic and tsunami hazard assessment. Our dataset comprises 158 earthquakes with a total of 316 rupture models selected from the SRCMOD database (http://equake-rc.info/srcmod). We find that fault-length does not saturate with earthquake magnitude, while fault-width reveals inhibited growth due to the finite seismogenic thickness. For strike-slip earthquakes, fault-length grows more rapidly with increasing magnitude compared to events of other faulting types. Interestingly, our derived relationship falls between the L-model and W-model end-members. In contrast, both reverse and normal dip-slip events are more consistent with self-similar scaling of fault-length. However, fault-width scaling relationships for large strike-slip and normal dip-slip events, occurring on steeply dipping faults (δ~90° for strike-slip faults, and δ~60° for normal faults), deviate from self-similarity. Although reverse dip-slip events in general show self-similar scaling, the restricted growth of down-dip fault extent (with upper limit of ~200 km) can be seen for mega-thrust subduction events (M~9.0). Despite this fact, for a given earthquake magnitude, subduction reverse dip-slip events occupy relatively larger rupture area, compared to shallow crustal events. In addition, we characterize slip heterogeneity in terms of its probability distribution and spatial correlation structure to develop a complete stochastic random-field characterization of earthquake slip. We find that truncated exponential law best describes the probability distribution of slip, with observable scale parameters determined by the average and maximum slip. Applying Box-Cox transformation to slip distributions (to create quasi-normal distributed data) supports cube-root transformation, which also implies distinctive non-Gaussian slip

Seismic Hazard of the Uttarakhand Himalaya, India, from Deterministic Modeling of Possible Rupture Planes in the Area

Directory of Open Access Journals (Sweden)

Anand Joshi

2013-01-01

Full Text Available This paper presents use of semiempirical method for seismic hazard zonation. The seismotectonically important region of Uttarakhand Himalaya has been considered in this work. Ruptures along the lineaments in the area identified from tectonic map are modeled deterministically using semi empirical approach given by Midorikawa (1993. This approach makes use of attenuation relation of peak ground acceleration for simulating strong ground motion at any site. Strong motion data collected over a span of three years in this region have been used to develop attenuation relation of peak ground acceleration of limited magnitude and distance applicability. The developed attenuation relation is used in the semi empirical method to predict peak ground acceleration from the modeled rupture planes in the area. A set of values of peak ground acceleration from possible ruptures in the area at the point of investigation is further used to compute probability of exceedance of peak ground acceleration of values 100 and 200 gals. The prepared map shows that regions like Tehri, Chamoli, Almora, Srinagar, Devprayag, Bageshwar, and Pauri fall in a zone of 10% probability of exceedence of peak ground acceleration of value 200 gals.

Pipe rupture and steam/water hammer design loads for dynamic analysis of piping systems

International Nuclear Information System (INIS)

Strong, B.R. Jr.; Baschiere, R.J.

1978-01-01

The design of restraints and protection devices for nuclear Class I and Class II piping systems must consider severe pipe rupture and steam/water hammer loadings. Limited stress margins require that an accurate prediction of these loads be obtained with a minimum of conservatism in the loads. Methods are available currently for such fluid transient load development, but each method is severely restricted as to the complexity and/or the range of fluid state excursions which can be simulated. This paper presents a general technique for generation of pipe rupture and steam/water hammer design loads for dynamic analysis of nuclear piping systems which does not have the limitations of existing methods. Blowdown thrust loadings and unbalanced piping acceleration loads for restraint design of all nuclear piping systems may be found using this method. The technique allows the effects of two-phase distributed friction, liquid flashing and condensation, and the surrounding thermal and mechanical equipment to be modeled. A new form of the fluid momentum equation is presented which incorporates computer generated fluid acceleration histories by inclusion of a geometry integral termed the 'force equivalent area' (FEA). The FEA values permit the coupling of versatile thermal-hydraulic programs to piping dynamics programs. Typical applications of the method to pipe rupture problems are presented and the resultant load histories compared with existing techniques. (Auth.)

Method of experimental and theoretical modeling for multiple pressure tube rupture for RBMK reactor

International Nuclear Information System (INIS)

Medvedeva, N.Y.; Goldstein, R.V.; Burrows, J.A.

2001-01-01

The rupture of single RBMK reactor channels has occurred at a number of stations with a variety of initiating events. It is assumed in RBMK Safety Cases that the force of the escaping fluid will not cause neighbouring channels to break. This assumption has not been justified. A chain reaction of tube breaks could over-pressurise the reactor cavity leading to catastrophic failure of the containment. To validate the claims of the RBMK Safety Cases the Electrogorsk Research and Engineering Centre, in participation with experts from the Institute of Mechanics of RAS, has developed the method of interacting multiscale physical and mathematical modelling for coupled thermophysical, hydrogasodynamic processes and deformation and break processes causing and (or) accompanying potential failures, design and beyond the design RBMK reactor accidents. To realise the method the set of rigs, physical and mathematical models and specialized computer codes are under creation. This article sets out an experimental philosophy and programme for achieving this objective to solve the problem of credibility or non-credibility for multiple fuel channel rupture in RBMK.(author)

Common and uncommon CT findings in rupture and impending rupture of abdominal aortic aneurysms

International Nuclear Information System (INIS)

Ahmed, M.Z.; Ling, L.; Ettles, D.F.

2013-01-01

The rapid imaging evaluation and diagnosis of rupture and impending rupture of an abdominal aortic aneurysm (AAA) is imperative. This article describes the imaging findings of rupture, impending rupture, and other abdominal aortic abnormalities. It is important not to overlook AAA as the consequences can be life threatening. All patients who had open or endovascular repair of AAA rupture over 6 years (2008–2012) were identified from our departmental database. The computed tomography (CT) images of 99 patients were reviewed for relevant findings. The mean age of the patients was 65 years and 85% were male

3D Dynamic Rupture Simulations along Dipping Faults, with a focus on the Wasatch Fault Zone, Utah

Science.gov (United States)

Withers, K.; Moschetti, M. P.

2017-12-01

We study dynamic rupture and ground motion from dip-slip faults in regions that have high-seismic hazard, such as the Wasatch fault zone, Utah. Previous numerical simulations have modeled deterministic ground motion along segments of this fault in the heavily populated regions near Salt Lake City but were restricted to low frequencies ( 1 Hz). We seek to better understand the rupture process and assess broadband ground motions and variability from the Wasatch Fault Zone by extending deterministic ground motion prediction to higher frequencies (up to 5 Hz). We perform simulations along a dipping normal fault (40 x 20 km along strike and width, respectively) with characteristics derived from geologic observations to generate a suite of ruptures > Mw 6.5. This approach utilizes dynamic simulations (fully physics-based models, where the initial stress drop and friction law are imposed) using a summation by parts (SBP) method. The simulations include rough-fault topography following a self-similar fractal distribution (over length scales from 100 m to the size of the fault) in addition to off-fault plasticity. Energy losses from heat and other mechanisms, modeled as anelastic attenuation, are also included, as well as free-surface topography, which can significantly affect ground motion patterns. We compare the effect of material structure and both rate and state and slip-weakening friction laws have on rupture propagation. The simulations show reduced slip and moment release in the near surface with the inclusion of plasticity, better agreeing with observations of shallow slip deficit. Long-wavelength fault geometry imparts a non-uniform stress distribution along both dip and strike, influencing the preferred rupture direction and hypocenter location, potentially important for seismic hazard estimation.

Searching for evidence of a preferred rupture direction in small earthquakes at Parkfield

Science.gov (United States)

Kane, D. L.; Shearer, P. M.; Allmann, B.; Vernon, F. L.

2009-12-01

Theoretical modeling of strike-slip ruptures along a bimaterial interface suggests that the interface will have a preferred rupture direction and will produce asymmetric ground motion (Shi and Ben-Zion, 2006). This could have widespread implications for earthquake source physics and for hazard analysis on mature faults because larger ground motions would be expected in the direction of rupture propagation. Studies have shown that many large global earthquakes exhibit unilateral rupture, but a consistently preferred rupture direction along faults has not been observed. Some researchers have argued that the bimaterial interface model does not apply to natural faults, noting that the rupture of the M 6 2004 Parkfield earthquake propagated in the opposite direction from previous M 6 earthquakes along that section of the San Andreas Fault (Harris and Day, 2005). We analyze earthquake spectra from the Parkfield area to look for evidence of consistent rupture directivity along the San Andreas Fault. We separate the earthquakes into spatially defined clusters and quantify the differences in high-frequency energy among earthquakes recorded at each station. Propagation path effects are minimized in this analysis because we compare earthquakes located within a small volume and recorded by the same stations. By considering a number of potential end-member models, we seek to determine if a preferred rupture direction is present among small earthquakes at Parkfield.

Morphological characteristics associated with rupture risk of multiple intracranial aneurysms.

Science.gov (United States)

Wang, Guang-Xian; Liu, Lan-Lan; Wen, Li; Cao, Yun-Xing; Pei, Yu-Chun; Zhang, Dong

2017-10-01

To identify the morphological parameters that are related to intracranial aneurysms (IAs) rupture using a case-control model. A total of 107 patients with multiple IAs and aneurysmal subarachnoid hemorrhage between August 2011 and February 2017 were enrolled in this study. Characteristics of IAs location, shape, neck width, perpendicular height, depth, maximum size, flow angle, parent vessel diameter (PVD), aspect ratio (AR) and size ratio (SR) were evaluated using CT angiography. Multiple logistic regression analysis was used to identify the independent risk factors associated with IAs rupture. Receiver operating characteristic curve analysis was performed on the final model, and the optimal thresholds were obtained. IAs located in the internal carotid artery (ICA) was associated with a negative risk of rupture, whereas AR, SR1 (height/PVD) and SR2 (depth/PVD) were associated with increased risk of rupture. When SR was calculated differently, the odds ratio values of these factors were also different. The receiver operating characteristic curve showed that AR, SR1 and SR2 had cut-off values of 1.01, 1.48 and 1.40, respectively. SR3 (maximum size/PVD) was not associated with IAs rupture. IAs located in the ICA are associated with a negative risk of rupture, while high AR (>1.01), SR1 (>1.48) or SR2 (>1.40) are risk factors for multiple IAs rupture. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Resolution of alliance ruptures: The special case of animal-assisted psychotherapy.

Science.gov (United States)

Zilcha-Mano, Sigal

2017-01-01

Many therapists regard alliance ruptures as one of the greatest challenges therapists face in the therapy room. Alliance ruptures has been previously defined as breakdowns in the process of negotiation of treatment tasks and goals and a deterioration in the affective bond between patient and therapist. Alliance ruptures have been found to predict premature termination of treatment and poor treatment outcomes. But ruptures can also present important opportunities for gaining insight and awareness and for facilitating therapeutic change. A process of rupture resolution may lead to beneficial outcomes and serve as a corrective emotional experience. The article describes unique processes of alliance rupture resolution inherent in animal-assisted psychotherapy (AAP). Building on Safran and Muran's model and on clinical examples, the article describes strategies for identifying ruptures in AAP and techniques for repairing them to facilitate a corrective experience in treatment. Implications for clinical practice and future research are discussed.

Single Tube Rupture at Cold Side of Steam Generator Simulation Test Report Using the ATLAS

International Nuclear Information System (INIS)

Kang, Kyoung Ho; Park, Hyun Sik; Cho, Seok

2010-12-01

In this study, a postulated SGTR event of the APR1400 was experimentally investigated with the ATLAS. In order to simulate a double-ended rupture of a single U-tube in the APR1400, the SGTR-CL-01 test was performed with the ATLAS. The main objectives of this test were not only to provide a physical insight into the system response of the APR1400 during the SGTR but also to produce integral effect experimental data to validate the safety analysis code. In the present report, major thermal-hydraulic phenomena such as the system pressures, the collapsed water levels, and the break flow rate were presented and discussed. Following the reactor trip induced by high steam generator level (HSGL) signal, the primary system pressure decreased and the secondary system pressure increased until the MSSVs was opened. The MSSVs repeated on and off status depending on the secondary system pressure during the whole test period. Due to the break flow, the collapsed water level of the affected steam generator showed milder decrease than that of the intact steam generator. This integral effect test data will be used to evaluate the prediction capability of existing safety analysis codes of the MARS and the RELAP5 as well as the SPACE code. Furthermore, this data can be utilized to identify any code deficiency for a SGTR simulation, especially for DVI-adapted plants

The diagnosis of breast implant rupture

DEFF Research Database (Denmark)

Hölmich, Lisbet R; Vejborg, Ilse; Conrad, Carsten

2005-01-01

participated in either one or two study MRI examinations, aiming at determining the prevalence and incidence of silent implant rupture, respectively, and who subsequently underwent explantation. Implant rupture status was determined by four independent readers and a consensus diagnosis of either rupture...... were in fact ruptured at surgery. Thirty-four of the 43 intact implants were described as intact at surgery. When categorising possible ruptures as ruptures, there were one false positive and nine false negative rupture diagnoses at MRI yielding an accuracy of 92%, a sensitivity of 89...

Dynamic rupture simulation of the 2017 Mw 7.8 Kaikoura (New Zealand) earthquake: Is spontaneous multi-fault rupture expected?

Science.gov (United States)

Ando, R.; Kaneko, Y.

2017-12-01

The coseismic rupture of the 2016 Kaikoura earthquake propagated over the distance of 150 km along the NE-SW striking fault system in the northern South Island of New Zealand. The analysis of In-SAR, GPS and field observations (Hamling et al., 2017) revealed that the most of the rupture occurred along the previously mapped active faults, involving more than seven major fault segments. These fault segments, mostly dipping to northwest, are distributed in a quite complex manner, manifested by fault branching and step-over structures. Back-projection rupture imaging shows that the rupture appears to jump between three sub-parallel fault segments in sequence from the south to north (Kaiser et al., 2017). The rupture seems to be terminated on the Needles fault in Cook Strait. One of the main questions is whether this multi-fault rupture can be naturally explained with the physical basis. In order to understand the conditions responsible for the complex rupture process, we conduct fully dynamic rupture simulations that account for 3-D non-planar fault geometry embedded in an elastic half-space. The fault geometry is constrained by previous In-SAR observations and geological inferences. The regional stress field is constrained by the result of stress tensor inversion based on focal mechanisms (Balfour et al., 2005). The fault is governed by a relatively simple, slip-weakening friction law. For simplicity, the frictional parameters are uniformly distributed as there is no direct estimate of them except for a shallow portion of the Kekerengu fault (Kaneko et al., 2017). Our simulations show that the rupture can indeed propagate through the complex fault system once it is nucleated at the southernmost segment. The simulated slip distribution is quite heterogeneous, reflecting the nature of non-planar fault geometry, fault branching and step-over structures. We find that optimally oriented faults exhibit larger slip, which is consistent with the slip model of Hamling et al

Evaluation of PWR response to main-steamline break with concurrent steam-generator tube rupture and small-break LOCA

International Nuclear Information System (INIS)

Laaksonen, J.T.; Sheron, B.W.

1982-12-01

In 1980, the NRC staff raised a potential safety issue involving a coincident steamline break, steam generator tube rupture, and small-break loss-of-coolant accident (LOCA). The bases for this concern were that the system response, primarily the maintenance of core cooling, was unanalyzed and the adequacy of the present guidance to operators to respond to combination LOCAs was unknown. This report discusses the staff evaluations performed to assess the system response and the adequacy of the present emergency operator guidelines. In all of the analyzed cases the primary coolant shrinkage, caused by overcooling, and the simultaneous loss of coolant can be compensated by the high pressure emergency core cooling system. The core remains covered with liquid, and the primary coolant remains subcooled, except in the vessel upper head. If the steamline break is outside the containment and cannot be isolated, the radiological consequences could be more severe than in any accident currently analyzed in a typical plant Final Safety Evaluation Report (FSAR). To decrease the risk of elevated offsite releases, an early diagnosis of the tube rupture has to be ensured. This can be done by upgrading operator instructions. The appropriate mitigating actions are in the existing instructions

Splenic rupture following idiopathic rupture of the urinary bladder presenting as acute abdomen

Directory of Open Access Journals (Sweden)

Jurisic D

2007-01-01

Full Text Available Idiopathic rupture of the urinary bladder is an uncommon condition and represents less than 1% of all bladder rupture cases. In most of the cases the main etiological factor was heavy alcohol ingestion. A combined injury of the spleen and bladder is a very rare condition that is almost often associated with trauma and foreign bodies. In this paper we present the extremely rare clinical course of acute abdomen caused by a combined spontaneous intraperitoneal injury; spontaneous rupture of the urinary bladder and spleen. According to our opinion, spontaneous bladder rupture caused by bladder distension due to alcohol ingestion led to urinary ascites and abdominal distension. Finally, repeated minor abdominal blunt trauma during everyday life, to a moderately distended abdomen caused a spontaneous splenic rupture in the patient with abnormal coagulation studies.

Slip reactivation model for the 2011 Mw9 Tohoku earthquake: Dynamic rupture, sea floor displacements and tsunami simulations.

Science.gov (United States)

Galvez, P.; Dalguer, L. A.; Rahnema, K.; Bader, M.

2014-12-01

The 2011 Mw9 Tohoku earthquake has been recorded with a vast GPS and seismic network given unprecedented chance to seismologists to unveil complex rupture processes in a mega-thrust event. In fact more than one thousand near field strong-motion stations across Japan (K-Net and Kik-Net) revealed complex ground motion patterns attributed to the source effects, allowing to capture detailed information of the rupture process. The seismic stations surrounding the Miyagi regions (MYGH013) show two clear distinct waveforms separated by 40 seconds. This observation is consistent with the kinematic source model obtained from the inversion of strong motion data performed by Lee's et al (2011). In this model two rupture fronts separated by 40 seconds emanate close to the hypocenter and propagate towards the trench. This feature is clearly observed by stacking the slip-rate snapshots on fault points aligned in the EW direction passing through the hypocenter (Gabriel et al, 2012), suggesting slip reactivation during the main event. A repeating slip on large earthquakes may occur due to frictional melting and thermal fluid pressurization effects. Kanamori & Heaton (2002) argued that during faulting of large earthquakes the temperature rises high enough creating melting and further reduction of friction coefficient. We created a 3D dynamic rupture model to reproduce this slip reactivation pattern using SPECFEM3D (Galvez et al, 2014) based on a slip-weakening friction with sudden two sequential stress drops . Our model starts like a M7-8 earthquake breaking dimly the trench, then after 40 seconds a second rupture emerges close to the trench producing additional slip capable to fully break the trench and transforming the earthquake into a megathrust event. The resulting sea floor displacements are in agreement with 1Hz GPS displacements (GEONET). The seismograms agree roughly with seismic records along the coast of Japan.The simulated sea floor displacement reaches 8-10 meters of

Spontaneous rupture of ovarian cystadenocarcinoma: pre- and post-rupture computed tomography evaluation

Energy Technology Data Exchange (ETDEWEB)

Salvadori, Priscila Silveira; Atzingen, Augusto Castelli von; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina; Bomfim, Lucas Novais [Universidade Tiradentes (UNIT), Maceio, AL, (Brazil)

2015-09-15

Epithelial ovarian tumors are the most common malignant ovarian neoplasms and, in most cases, eventual rupture of such tumors is associated with a surgical procedure. The authors report the case of a 54-year-old woman who presented with spontaneous rupture of ovarian cystadenocarcinoma documented by computed tomography, both before and after the event. In such cases, a post-rupture staging tends to be less favorable, compromising the prognosis. (author)

A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

Directory of Open Access Journals (Sweden)

Wei Yee Leong

2013-07-01

Full Text Available Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. Conclusion: The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient. Keywords: Quadriceps tendon rupture; Achilles tendon rupture; Bilateral.

Distance and Azimuthal Dependence of Ground‐Motion Variability for Unilateral Strike‐Slip Ruptures

KAUST Repository

Vyas, Jagdish Chandra; Mai, Paul Martin; Galis, Martin

2016-01-01

We investigate near‐field ground‐motion variability by computing the seismic wavefield for five kinematic unilateral‐rupture models of the 1992 Mw 7.3 Landers earthquake, eight simplified unilateral‐rupture models based on the Landers event, and a

Why Did the Fault Rupture of the 2008 Wenchuan Earthquake Propagate Predominately Northeastwards?

Science.gov (United States)

Zhu, S.; Yuan, J.

2017-12-01

The rupture processes of the 2008 Wenchuan earthquake are much complex. The rupture propagated northeastward a large distance as long as 300 km, but rupture length is short in the southwest direction. Although a great deal of attention has been paid to why the rupture propagated preponderantly northeastward in the 2008 Wenchuan earthquake, the physical mechanism remains unclear. By means of finite element model, in which bimaterial contrast across the Longmen Shan fault is taken into account, nucleation process is initiated at the center of the fault, ruptures then spread out outward spontaneously in both directions. The simulated results show that the different materials between both sides of the fault lead to tensile changes of normal stresses on the fault, which enhance the propagation of the ruptures in northeastward direction. We found that bimaterial mechanism is important for earthquake ruptures, and mode II rupture evolves with propagation distance along a bimaterial interface to a unilateral wrinkle-like Weertman pulse in the direction of slip on the more compliant side of the fault, namely in the positive direction (i.e, the northeast direction in the study). The Weertman pulse can be self-amplified, self-sustained and self-healing, which gives rise to little frictional energy and long propagation distance. This may be the reason why the Wenchuan earthquake is a unilateral fault rupture and a high seismic magnitude. In addition, the modelling results suggest that the rupture distance is much smaller if the material in the model is homogeneous, in which no huge earthquakes can occur like the 2008 Wenchan event. This research was jointly supported by the National Natural Science Foundation of China (41574041), Beijing Natural Science Foundation (8152034), and by Basic Research Project (ZDJ2017-08).

Hepatic rupture in preeclampsia

International Nuclear Information System (INIS)

Winer-Muram, H.T.; Muram, D.; Salazar, J.; Massie, J.D.

1985-01-01

The diagnosis of hepatic rupture in patients with pregnancy-induced hypertension (preeclampsia and eclampsia) is rarely made preoperatively. Diagnostic imaging can be utilized in some patients to confirm the preoperative diagnosis. Since hematoma formation precedes hepatic rupture, then, when diagnostic modalities such as sonography and computed tomography identify patients with hematomas, these patients are at risk of rupture, and should be hospitalized until the hematomas resolve

Pressurization rate effect on ligament rupture and burst pressures of cracked steam generator tubes

International Nuclear Information System (INIS)

Majumdar, S.; Kasza, K.

2009-01-01

The question of whether ligament rupture pressure or unstable burst pressure may vary significantly with pressurization rate at room temperature arose from the results of pressure tests by industry on tubes with machined part-throughwall notches. Slow (quasi-static) and fast 14 MPa/s (2000 psi/s) pressurization rate tests on specimens with nominally the same notch geometry appeared to show a significant effect of the rate of pressurization on the unstable burst pressure. Unfortunately, the slow and fast loading rate tests were conducted following two different test procedures, which could confound the results. The current series of tests were conducted on a variety of specimen geometries using a consistent test procedure to better establish the effect of pressurization rate on ligament rupture and burst pressures. (author)

Pressurization rate effect on ligament rupture and burst pressures of cracked steam generator tubes

Energy Technology Data Exchange (ETDEWEB)

Majumdar, S.; Kasza, K. [Argonne National Laboratory, Nuclear Energy Division, Lemont, Illinois (United States)

2009-07-01

The question of whether ligament rupture pressure or unstable burst pressure may vary significantly with pressurization rate at room temperature arose from the results of pressure tests by industry on tubes with machined part-throughwall notches. Slow (quasi-static) and fast 14 MPa/s (2000 psi/s) pressurization rate tests on specimens with nominally the same notch geometry appeared to show a significant effect of the rate of pressurization on the unstable burst pressure. Unfortunately, the slow and fast loading rate tests were conducted following two different test procedures, which could confound the results. The current series of tests were conducted on a variety of specimen geometries using a consistent test procedure to better establish the effect of pressurization rate on ligament rupture and burst pressures. (author)

Dynamic mortar finite element method for modeling of shear rupture on frictional rough surfaces

Science.gov (United States)

Tal, Yuval; Hager, Bradford H.

2017-09-01

This paper presents a mortar-based finite element formulation for modeling the dynamics of shear rupture on rough interfaces governed by slip-weakening and rate and state (RS) friction laws, focusing on the dynamics of earthquakes. The method utilizes the dual Lagrange multipliers and the primal-dual active set strategy concepts, together with a consistent discretization and linearization of the contact forces and constraints, and the friction laws to obtain a semi-smooth Newton method. The discretization of the RS friction law involves a procedure to condense out the state variables, thus eliminating the addition of another set of unknowns into the system. Several numerical examples of shear rupture on frictional rough interfaces demonstrate the efficiency of the method and examine the effects of the different time discretization schemes on the convergence, energy conservation, and the time evolution of shear traction and slip rate.

Investigation on Stress-Rupture Behavior of a Chopped-Glass-Fiber Composite for Automotive Durability Design Criteria

Energy Technology Data Exchange (ETDEWEB)

Ren, W

2001-08-24

Practical and inexpensive testing methods were developed to investigate stress-rupture properties of a polymeric composite with chopped glass fiber reinforcement for automotive applications. The material was tested in representative automotive environments to generate experimental data. The results indicate that environments have substantial effects on the stress-rupture behavior. The data were analyzed and developed into stress-rupture design criteria to address one of the durability aspects of the material for automotive structural applications.

Source properties of dynamic rupture pulses with off-fault plasticity

KAUST Repository

Gabriel, A.-A.

2013-08-01

Large dynamic stresses near earthquake rupture fronts may induce an inelastic response of the surrounding materials, leading to increased energy absorption that may affect dynamic rupture. We systematically investigate the effects of off-fault plastic energy dissipation in 2-D in-plane dynamic rupture simulations under velocity-and-state-dependent friction with severe weakening at high slip velocity. We find that plasticity does not alter the nature of the transitions between different rupture styles (decaying versus growing, pulse-like versus crack-like, and subshear versus supershear ruptures) but increases their required background stress and nucleation size. We systematically quantify the effect of amplitude and orientation of background shear stresses on the asymptotic properties of self-similar pulse-like ruptures: peak slip rate, rupture speed, healing front speed, slip gradient, and the relative contribution of plastic strain to seismic moment. Peak slip velocity and rupture speed remain bounded. From fracture mechanics arguments, we derive a nonlinear relation between their limiting values, appropriate also for crack-like and supershear ruptures. At low background stress, plasticity turns self-similar pulses into steady state pulses, for which plastic strain contributes significantly to the seismic moment. We find that the closeness to failure of the background stress state is an adequate predictor of rupture speed for relatively slow events. Our proposed relations between state of stress and earthquake source properties in the presence of off-fault plasticity may contribute to the improved interpretation of earthquake observations and to pseudodynamic source modeling for ground motion prediction.

Surface rupturing earthquakes repeated in the 300 years along the ISTL active fault system, central Japan

Science.gov (United States)

Katsube, Aya; Kondo, Hisao; Kurosawa, Hideki

2017-06-01

Surface rupturing earthquakes produced by intraplate active faults generally have long recurrence intervals of a few thousands to tens of thousands of years. We here report the first evidence for an extremely short recurrence interval of 300 years for surface rupturing earthquakes on an intraplate system in Japan. The Kamishiro fault of the Itoigawa-Shizuoka Tectonic Line (ISTL) active fault system generated a Mw 6.2 earthquake in 2014. A paleoseismic trench excavation across the 2014 surface rupture showed the evidence for the 2014 event and two prior paleoearthquakes. The slip of the penultimate earthquake was similar to that of 2014 earthquake, and its timing was constrained to be after A.D. 1645. Judging from the timing, the damaged area, and the amount of slip, the penultimate earthquake most probably corresponds to a historical earthquake in A.D. 1714. The recurrence interval of the two most recent earthquakes is thus extremely short compared with intervals on other active faults known globally. Furthermore, the slip repetition during the last three earthquakes is in accordance with the time-predictable recurrence model rather than the characteristic earthquake model. In addition, the spatial extent of the 2014 surface rupture accords with the distribution of a serpentinite block, suggesting that the relatively low coefficient of friction may account for the unusually frequent earthquakes. These findings would affect long-term forecast of earthquake probability and seismic hazard assessment on active faults.

Apoptosis of rabbit retinal cell after eyeball rupture.

Science.gov (United States)

Tian, Xue-Min; Zhu, Yu

2013-04-13

To establish rabbit eyeball rupture model by air gun in order to observe and analyze the early injury condition and reasons of retinal cell after eyeball rupture. Forty eight healthy rabbits were randomly divided into control group and 1, 3, 6, 12 and 24 h after injury groups. After anesthesia, the rabbit eyeball rupture model was established by air gun. Then the early pathological changes of rabbit retina were observed, and apoptotic index (AI), oncosis index (OI), the relationship between the expression amounts of apoptosis-related genes and AI were analyzed. Obvious pathological lesion appeared in retina 6 h after injury. Irreversible damage occurred 12-24 h after injury. The results of AI and OI indicated that the OI peak appeared 6 h after injury and then gradually declined, while the AI increased with the prolongation of time, and the AI was higher than OI in 12 h after injury. Immunohistochemical results indicated that there was no obvious bcl-2 protein expression change. Compared with the control group and the 3, 6, 12 and 24 h after the injury groups, the expressions of p53 and Caspase-3 were significantly improved and peaked at 12 h (Peyeball rupture. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Three-Dimensional Dynamic Rupture in Brittle Solids and the Volumetric Strain Criterion

Science.gov (United States)

Uenishi, K.; Yamachi, H.

2017-12-01

As pointed out by Uenishi (2016 AGU Fall Meeting), source dynamics of ordinary earthquakes is often studied in the framework of 3D rupture in brittle solids but our knowledge of mechanics of actual 3D rupture is limited. Typically, criteria derived from 1D frictional observations of sliding materials or post-failure behavior of solids are applied in seismic simulations, and although mode-I cracks are frequently encountered in earthquake-induced ground failures, rupture in tension is in most cases ignored. Even when it is included in analyses, the classical maximum principal tensile stress rupture criterion is repeatedly used. Our recent basic experiments of dynamic rupture of spherical or cylindrical monolithic brittle solids by applying high-voltage electric discharge impulses or impact loads have indicated generation of surprisingly simple and often flat rupture surfaces in 3D specimens even without the initial existence of planes of weakness. However, at the same time, the snapshots taken by a high-speed digital video camera have shown rather complicated histories of rupture development in these 3D solid materials, which seem to be difficult to be explained by, for example, the maximum principal stress criterion. Instead, a (tensile) volumetric strain criterion where the volumetric strain (dilatation or the first invariant of the strain tensor) is a decisive parameter for rupture seems more effective in computationally reproducing the multi-directionally propagating waves and rupture. In this study, we try to show the connection between this volumetric strain criterion and other classical rupture criteria or physical parameters employed in continuum mechanics, and indicate that the criterion has, to some degree, physical meanings. First, we mathematically illustrate that the criterion is equivalent to a criterion based on the mean normal stress, a crucial parameter in plasticity. Then, we mention the relation between the volumetric strain criterion and the

Relap5/Mod3.1 analysis of main steam header rupture in VVER- 440/213 NPP

Energy Technology Data Exchange (ETDEWEB)

Kral, P. [Nuclear Research Inst. Rez (Switzerland)

1995-12-31

The presentation is focused on two main topics. First the applied modelling of PGV-4 steam generator for RELAP5 code are described. The results of steady-state calculation under reference conditions are compared against measured data. The problem of longitudinal subdivision of SG tubes is analysed and evaluated. Secondly, a best-estimate analysis of main steam header (MSH) rupture accident in WWER-440/213 NPP is presented. The low reliability of initiation of ESFAS signal `MSH Rupture` leads in this accident to big loss of secondary coolant, full depressurization of main steam system, extremely fast cool-down of both secondary and primary system, opening of PRZ SV-bypass valve with later liquid outflow, potential reaching of secondary criticality by failure of HPIS. 7 refs.

Relap5/Mod3.1 analysis of main steam header rupture in VVER- 440/213 NPP

Energy Technology Data Exchange (ETDEWEB)

Kral, P [Nuclear Research Inst. Rez (Switzerland)

1996-12-31

The presentation is focused on two main topics. First the applied modelling of PGV-4 steam generator for RELAP5 code are described. The results of steady-state calculation under reference conditions are compared against measured data. The problem of longitudinal subdivision of SG tubes is analysed and evaluated. Secondly, a best-estimate analysis of main steam header (MSH) rupture accident in WWER-440/213 NPP is presented. The low reliability of initiation of ESFAS signal `MSH Rupture` leads in this accident to big loss of secondary coolant, full depressurization of main steam system, extremely fast cool-down of both secondary and primary system, opening of PRZ SV-bypass valve with later liquid outflow, potential reaching of secondary criticality by failure of HPIS. 7 refs.

Relap5/Mod3.1 analysis of main steam header rupture in VVER- 440/213 NPP

International Nuclear Information System (INIS)

Kral, P.

1995-01-01

The presentation is focused on two main topics. First the applied modelling of PGV-4 steam generator for RELAP5 code are described. The results of steady-state calculation under reference conditions are compared against measured data. The problem of longitudinal subdivision of SG tubes is analysed and evaluated. Secondly, a best-estimate analysis of main steam header (MSH) rupture accident in WWER-440/213 NPP is presented. The low reliability of initiation of ESFAS signal 'MSH Rupture' leads in this accident to big loss of secondary coolant, full depressurization of main steam system, extremely fast cool-down of both secondary and primary system, opening of PRZ SV-bypass valve with later liquid outflow, potential reaching of secondary criticality by failure of HPIS

High-Speed Observations of Dynamic Fracture Propagation in Solids and Their Implications in Earthquake Rupture Dynamics

Science.gov (United States)

Uenishi, Koji

2016-04-01

This contribution outlines our experimental observations of seismicity-related fast fracture (rupture) propagation in solids utilising high-speed analog and digital photography (maximum frame rate 1,000,000 frames per second) over the last two decades. Dynamic fracture may be triggered or initiated in the monolithic or layered seismic models by detonation of micro explosives, a projectile launched by a gun, laser pulses and electric discharge impulses, etc. First, we have investigated strike-slip rupture along planes of weakness in transparent photoelastic (birefringent) materials at a laboratory scale and shown (at that time) extraordinarily fast rupture propagation in a bi-material system and its possible effect on the generation of large strong motion in the limited narrow areas in the Kobe region on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake (Uenishi Ph.D. thesis 1997, Uenishi et al. BSSA 1999). In this series of experiments, we have also modelled shallow dip-slip earthquakes and indicated a possible origin of the asymmetric ground motion in the hanging and foot-walls. In the photoelastic photographs, we have found the unique dynamic wave interaction and generation of specific shear and interface waves numerically predicted by Uenishi and Madariaga (Eos 2005), and considered as a case study the seismic motion associated with the 2014 Nagano-ken Hokubu (Kamishiro Fault), Japan, dip-slip earthquake (Uenishi EFA 2015). Second, we have experimentally shown that even in a monolithic material, rupture speed may exceed the local shear wave speed if we employ hyperelasically behaving materials like natural rubber (balloons) (Uenishi Eos 2006, Uenishi ICF 2009, Uenishi Trans. JSME A 2012) but fracture in typical monolithic thin fluid films (e.g. soap bubbles, which may be treated as a solid material) propagates at an ordinary subsonic (sub-Rayleigh) speed (Uenishi et al. SSJ 2006). More recent investigation handling three-dimensional rupture propagation

Detailed evaluation of RCS boundary rupture during high-pressure severe accident sequences

International Nuclear Information System (INIS)

Park, Rae-Joon; Hong, Seong-Wan

2011-01-01

A depressurization possibility of the reactor coolant system (RCS) before a reactor vessel rupture during a high-pressure severe accident sequence has been evaluated for the consideration of direct containment heating (DCH) and containment bypass. A total loss of feed water (TLOFW) and a station blackout (SBO) of the advanced power reactor 1400 (APR 1400) has been evaluated from an initiating event to a creep rupture of the RCS boundary by using the SCDAP/RELAP5 computer code. In addition, intentional depressurization of the RCS using power-operated safety relief valves (POSRVs) has been evaluated. The SCDAPRELAP5 results have shown that the pressurizer surge line broke before the reactor vessel rupture failure, but a containment bypass did not occur because steam generator U tubes did not break. The intentional depressurization of the RCS using POSRV was effective for the DCH prevention at a reactor vessel rupture. (author)

Endometriosis-related spontaneous diaphragmatic rupture.

Science.gov (United States)

Triponez, Frédéric; Alifano, Marco; Bobbio, Antonio; Regnard, Jean-François

2010-10-01

Non-traumatic, spontaneous diaphragmatic rupture is a rare event whose pathophysiology is not known. We report the case of endometriosis-related spontaneous rupture of the right diaphragm with intrathoracic herniation of the liver, gallbladder and colon. We hypothesize that the invasiveness of endometriotic tissue caused diaphragm fragility, which finally lead to its complete rupture without traumatic event. The treatment consisted of a classical management of diaphragmatic rupture, with excision of the endometriotic nodule followed by medical ovarian suppression for six months.

Tensile and Creep-Rupture Evaluation of a New Heat of Haynes Alloy 25

International Nuclear Information System (INIS)

Shingledecker, J.P.; Glanton, D.B.; Martin, R.L.; Sparks, B.L.; Swindeman, R.W.

2007-01-01

From 1999 to 2006, a program was undertaken within the Materials Science and Technology Division, formerly the Metals and Ceramics Division, of Oak Ridge National Laboratory to characterize the tensile and creep-rupture properties of a newly produced heat of Haynes alloy 25 (L-605). Tensile properties from room temperature to 1100 C were evaluated for base material and welded joints aged up to 12,000 hours at 675 C. Creep and creep-rupture tests were conducted on base metal and cross-weldments from 650 to 950 C. Pressurized tubular creep tests were conducted to evaluate multiaxial creep-rupture response of the material. Over 800,000 hours of creep test data were generated during the test program with the longest rupture tests extending beyond 38,000 hours, and the longest creep-rate experiments exceeding 40,000 hours

Analysis of 30 breast implant rupture cases.

Science.gov (United States)

Tark, Kwan Chul; Jeong, Hii Sun; Roh, Tae Suk; Choi, Jong Woo

2005-01-01

Breast implants used for augmentation mammoplasty or breast reconstruction could rupture from various causes such as trauma or spontaneous failure. The objectives of this study were to investigate the relationships between the causes of implant rupture and the degree of capsular contracture, and then to evaluate the relative efficacies of specific signs on magnetic resonance imaging (MRI) known to be beneficial for diagnosing the rupture. A retrospective review identified patients with prosthetic implant rupture or impending rupture treated by the senior author. The 30 cases of implant rupture available for review were classified into two groups: intracapsular and extracapsular ruptures. The 30 cases of breast implant ruptures were analyzed with respect to the clinical symptoms and signs, the causes of rupture, the degree of capsular contracture, and therapeutic plans. Among the 30 cases, 14 patients who had undergone MRI during the diagnostic period were analyzed with respect to the relationships between MRI readings and operative findings. Spontaneous rupture of membranes was most common (80%), followed by failure because of trauma (7%) and valve or implant base (4%). The symptoms during implant rupture were contour deformity, palpated mass-like lesions, pain, and focal inflammation. According to the analysis of specific MRI signs, the sensitivity and specificity of the linguine sign were 87% and 100%, respectively, for intracapsular rupture. For extracapsular rupture, the sensitivity and specificity of the linguine sign were, respectively, 67% and 75%. The sensitivity and specificity of the rat-tail sign and tear drop sign were 14% and 50%, respectively. Breast implant rupture was correlated with the degree of capsular contracture in our study. Among the various specific MRI signs used in diagnosing the rupture, the linguine sign was reliable and had a high sensitivity and specificity, especially in cases of intracapsular rupture. On the other hand, the rat

Creep and rupture of an ODS alloy with high stress rupture ductility. [Oxide Dispersion Strengthened

Science.gov (United States)

Mcalarney, M. E.; Arsons, R. M.; Howson, T. E.; Tien, J. K.; Baranow, S.

1982-01-01

The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma-prime precipitates, was studied at 760 and 1093 C. At both temperatures, the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed including crystallographic fracture at intermediate temperatures and tearing or necking almost to a chisel point at higher temperatures. While the rupture ductility was high, the creep strength of the alloy was low relative to conventional gamma prime strengthened superalloys in the intermediate temperature range and to ODS alloys in the higher temperature range. These findings are discussed with respect to the alloy composition; the strengthening oxide phases, which are inhomogeneously dispersed; the grain morphology, which is coarse and elongated and exhibits many included grains; and the second phase inclusion particles occurring at grain boundaries and in the matrix. The creep properties, in particular the high stress dependencies and high creep activation energies measured, are discussed with respect to the resisting stress model of creep in particle strengthened alloys.

Investigation on Stress-Rupture Behavior of a Chopped-Glass-Fiber Composite for Automotive Durability Design Criteria; FINAL

International Nuclear Information System (INIS)

Ren, W

2001-01-01

Practical and inexpensive testing methods were developed to investigate stress-rupture properties of a polymeric composite with chopped glass fiber reinforcement for automotive applications. The material was tested in representative automotive environments to generate experimental data. The results indicate that environments have substantial effects on the stress-rupture behavior. The data were analyzed and developed into stress-rupture design criteria to address one of the durability aspects of the material for automotive structural applications

Analytical evaluation of the environment effect on creep rupture strength

International Nuclear Information System (INIS)

Tamura, Manabu; Ogawa, Yutaka; Kurata, Yuji; Kondo, Tatsuo

1982-04-01

An analytical approach was made in evaluating semi-quantitatively the effect of environment on rupture strength of materials. In the analysis the zone formed in the material by reaction with the environment was assumed to bear the applied load as one of the strength members. In calculations a law of mixtures of creep strength and the linear damage rule were applied. In the modeling of the load bearing by the composite structure of the environment-affected and intact zones, both parallel and series models were considered to formulate the equations. The equation for the parallel-loaded model was properly adopted in explaining semi-quantitatively the case of Incoloy alloy 800 crept in air, which was strengthened with the layer formed by nitrization. The equation for the serially loaded model was more successfully adopted to the evaluation of the rupture strength of dissimilar weld joints. The latter was also considered to be potentially adoptable to the problems of the effect of specimen size and shape on rupture strength, which had been often taken into account in evaluating the environment effect. For application of the developed method, examination was made to the possible decrease in rupture strength of Hastelloy alloy XR in long term tests by the formation of Cr depleted zone due to oxidation in HTGR impure helium, and the results were compared with the values obtained by experiments. (author)

Rupture of Achilles Tendon : Usefulness of Ultrasonography

International Nuclear Information System (INIS)

Kim, Nam Hyeon; Ki, Won Woo; Yoon, Kwon Ha; Kim, Song Mun; Shin, Myeong Jin; Kwon, Soon Tae

1996-01-01

To differentiate a complete rupture of Achilles tendon from an incomplete one which is important because its treatment is quite different. And it is necessary to know the exact site of the rupture preoperatively. Fifteen cases of fourteen patients which were diagnosed as Achilles tendon rupture by ultrasonography and surgery were reviewed. We compared sonographic rupture site with surgical findings. Ultrasonographic criteria for differentiation of complete and incomplete rupture was defined as follows : the discreteness, which means the proximal intervening hypoechogenicity to the interface echogenicity of distal margin of ruptured tendon : the slant sign, which represents the interface of ruptured distal margin which was seen over the 3/4 of the thickness of the tendon without intervening low echogeneicity : the invagination sign, which means the echogenic invagination from Kager triangle into posterior aspect of Achilles tendon over the half thickness of the tendon. The sites of complete tendon rupture were exactly corresponded to surgical finding in four cases of ten complete ruptures. And the discrepancy between sonographic and surgical findings in the site of complete rupture was 1.2 ± 0.4 cm in six cases. Three of ten complete ruptures showed the discreteness sign, all of ten showed the slant sign and two of ten showed the invagination sign. It is helpful to differentiate a complete from incomplete rupture of the Achilles tendon and to localize the site of the complete rupture with the ultrasonographic evaluation

Particle deposition modeling in the secondary side of a steam generator bundle model

Energy Technology Data Exchange (ETDEWEB)

Mukin, Roman, E-mail: roman.mukin@psi.ch; Dehbi, Abdel, E-mail: abdel.dehbi@psi.ch

2016-04-01

A steam generator (SG) tube rupture (SGTR) model is studied in this paper. This model based on a experimental facility called Aerosol Trapping In a Steam Generator (ARTIST), which is a model of a scaled steam generator tube bundle consisting of 270 tubes and a guillotine tube to address aerosol deposition phenomena on two different scales: near the tube break, where the gas velocities and turbulence are very intensive, and far away from the break, where the flow velocities are three orders of magnitude lower. Owing to complexity of the flow, 3D simulations with highly resolved computational mesh near the break were done. First, the flow inside an isolated tube with a guillotine tube break has been studied in the framework of Reynolds Averaged Navier Stokes (RANS) approach. The next part is devoted to the simulation of an inclined gas jet entering the SG tube bundle via the guillotine tube breach with more advanced CFD tools. In particular, Detached Eddy Simulation (DES) and RANS are applied to tackle the wide range of flow scales. Flow field velocity comparison showed that DES results are reproducing wavy structure of the flow field in far field from the break observed in experiment. Particle transport and deposition is modelled by Lagrangian continuous random walk (CRW) model, which has been developed and validated previously. It is found that the DES combined with the CRW to supply fluctuating velocity components predicts deposition rates that are generally within the scatter of the measured data. Monodisperse, spherical SiO{sub 2} particles with AMMD = 1.4 μm were used as aerosol particles in simulations. To be economically feasible, the computations were made with the open source CFD code OpenFOAM. Comparison of the calculated flow with the experimental axial velocity distribution data at different vertical levels has been performed.

New considerations on variability of creep rupture data and life prediction

International Nuclear Information System (INIS)

Kim, Seon Jin; Jeong, Won Taek; Kong, Yu Sik

2009-01-01

This paper deals with the variability analysis of short term creep rupture test data based on the previous creep rupture tests and the possibility of the creep life prediction. From creep tests performed by constant uniaxial stresses at 600, 650 and 700 .deg. C elevated temperature, in order to investigate the variability of short-term creep rupture data, the creep curves were analyzed for normalized creep strain divided by initial strain. There are some variability in thee creep rupture data. And, the difference between general creep curves and normalized creep curves were obtained. The effects of the creep rupture time and state steady creep rate on the Weibull distribution parameters were investigated. There were good relation between normal Weibull parameters and normalized Weibull parameters. Finally, the predicted creep life were compared with the Monkman-Grant model.

New Considerations on Variability of Creep Rupture Data and Life Prediction

International Nuclear Information System (INIS)

Jung, Won Taek; Kong, Yu Sik; Kim, Seon Jin

2009-01-01

This paper deals with the variability analysis of short term creep rupture test data based on the previous creep rupture tests and the possibility of the creep life prediction. From creep tests performed by constant uniaxial stresses at 600, 650 and 700 .deg. C elevated temperature, in order to investigate the variability of short-term creep rupture data, the creep curves were analyzed for normalized creep strain divided by initial strain. There are some variability in the creep rupture data. And, the difference between general creep curves and normalized creep curves were obtained. The effects of the creep rupture time (RT) and steady state creep rate (SSCR) on the Weibull distribution parameters were investigated. There were good relation between normal Weibull parameters and normalized Weibull parameters. Finally, the predicted creep life were compared with the Monkman-Grant model

Rupture of the Pitáycachi Fault in the 1887 Mw 7.5 Sonora, Mexico earthquake (southern Basin-and-Range Province): Rupture kinematics and epicenter inferred from rupture branching patterns

Science.gov (United States)

Suter, Max

2015-01-01

During the 3 May 1887 Mw 7.5 Sonora earthquake (surface rupture end-to-end length: 101.8 km), an array of three north-south striking Basin-and-Range Province faults (from north to south Pitáycachi, Teras, and Otates) slipped sequentially along the western margin of the Sierra Madre Occidental Plateau. This detailed field survey of the 1887 earthquake rupture zone along the Pitáycachi fault includes mapping the rupture scarp and measurements of surface deformation. The surface rupture has an endpoint-to-endpoint length of ≥41.0 km, dips 70°W, and is characterized by normal left-lateral extension. The maximum surface offset is 487 cm and the mean offset 260 cm. The rupture trace shows a complex pattern of second-order segmentation. However, this segmentation is not expressed in the 1887 along-rupture surface offset profile, which indicates that the secondary segments are linked at depth into a single coherent fault surface. The Pitáycachi surface rupture shows a well-developed bipolar branching pattern suggesting that the rupture originated in its central part, where the polarity of the rupture bifurcations changes. Most likely the rupture first propagated bilaterally along the Pitáycachi fault. The southern rupture front likely jumped across a step over to the Teras fault and from there across a major relay zone to the Otates fault. Branching probably resulted from the lateral propagation of the rupture after breaching the seismogenic part of the crust, given that the much shorter ruptures of the Otates and Teras segments did not develop branches.

Pulse-Like Rupture Induced by Three-Dimensional Fault Zone Flower Structures

KAUST Repository

Pelties, Christian

2014-07-04

© 2014, Springer Basel. Faults are often embedded in low-velocity fault zones (LVFZ) caused by material damage. Previous 2D dynamic rupture simulations (Huang and Ampuero, 2011; Huang et al., 2014) showed that if the wave velocity contrast between the LVFZ and the country rock is strong enough, ruptures can behave as pulses, i.e. with local slip duration (rise time) much shorter than whole rupture duration. Local slip arrest (healing) is generated by waves reflected from the LVFZ–country rock interface. This effect is robust against a wide range of fault zone widths, absence of frictional healing, variation of initial stress conditions, attenuation, and off-fault plasticity. These numerical studies covered two-dimensional problems with fault-parallel fault zone structures. Here, we extend previous work to 3D and geometries that are more typical of natural fault zones, including complexities such as flower structures with depth-dependent velocity and thickness, and limited fault zone depth extent. This investigation requires high resolution and flexible mesh generation, which are enabled here by the high-order accurate arbitrary high-order derivatives discontinuous Galerkin method with an unstructured tetrahedral element discretization (Peltieset al., 2012). We show that the healing mechanism induced by waves reflected in the LVFZ also operates efficiently in such three-dimensional fault zone structures and that, in addition, a new healing mechanism is induced by unloading waves generated when the rupture reaches the surface. The first mechanism leads to very short rise time controlled by the LVFZ width to wave speed ratio. The second mechanism leads to generally longer, depth-increasing rise times, is also conditioned by the existence of an LVFZ, and persists at some depth below the bottom of the LVFZ. Our simulations show that the generation of slip pulses by these two mechanisms is robust to the depth extent of the LVFZ and to the position of the hypocenter

Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

Science.gov (United States)

Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

2017-09-01

Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

Use of regional mechanical properties of abdominal aortic aneurysms to advance finite element modeling of rupture risk.

Science.gov (United States)

Tierney, Áine P; Callanan, Anthony; McGloughlin, Timothy M

2012-02-01

To investigate the use of regional variations in the mechanical properties of abdominal aortic aneurysms (AAA) in finite element (FE) modeling of AAA rupture risk, which has heretofore assumed homogeneous mechanical tissue properties. Electrocardiogram-gated computed tomography scans from 3 male patients with known infrarenal AAA were used to characterize the behavior of the aneurysm in 4 different segments (posterior, anterior, and left and right lateral) at maximum diameter and above the infrarenal aorta. The elasticity of the aneurysm (circumferential cyclic strain, compliance, and the Hudetz incremental modulus) was calculated for each segment and the aneurysm as a whole. The FE analysis inclusive of prestress (pre-existing tensile stress) produced a detailed stress pattern on each of the aneurysm models under pressure loading. The 4 largest areas of stress in each region were considered in conjunction with the local regional properties of the segment to define a specific regional prestress rupture index (RPRI). In terms of elasticity, there were average reductions of 68% in circumferential cyclic strain and 63% in compliance, with a >5-fold increase in incremental modulus, between the healthy and the aneurysmal aorta for each patient. There were also regional variations in all elastic properties in each individual patient. The average difference in total stress inclusive of prestress was 59%, 67%, and 15%, respectively, for the 3 patients. Comparing the strain from FE models with the CT scans revealed an average difference in strain of 1.55% for the segmented models and 3.61% for the homogeneous models, which suggests that the segmented models more accurately reflect in vivo behavior. RPRI values were calculated for each segment for all patients. A greater understanding of the local material properties and their use in FE models is essential for greater accuracy in rupture prediction. Quantifying the regional behavior will yield insight into the changes in

Analysing The Thermalhydraulic Parameters Of VVER-1000 Reactor For The Accident Of Steam Generator Tube Rupture

International Nuclear Information System (INIS)

Luu Nam Hai; Truong Cong Thang

2011-01-01

To ensure the safety operation of nuclear power plant (NPP), a lot of postulated accident scenarios were considered and analysed. This research chose and analysed the accident of steam generator tube rupture (SGTR) under the actual plant conditions by using the simulation program PCTRAN. The SGTR accident is happen when the NPP is under operation with the steady state condition (power of 3000 MWth, primary pressure of 157 bar and secondary pressure of 63 bar). The accident is initiated by creating a break with equivalent diameter of 100 mm in the area of lower row heat exchanging tubes. The result of analysis is compared with the calculation of the Shariz University, Iran using the thermal hydraulics code RELAP5/mod3.2 and the report in the PSAR data of VVER-1000. This comparison shows that it is possible for using PCTRAN to analyse accidents of VVER-1000 reactor. (author)

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms.

Directory of Open Access Journals (Sweden)

Nan Lv

Full Text Available The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA aneurysms.In 129 PCoA aneurysms (85 ruptured, 44 unruptured, clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms.While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR, size ratio (SR, dome-to-neck ratio (DN, inflow angle (IA, normalized wall shear stress (NWSS and percentage of low wall shear stress area (LSA were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p < 0.001 and LSA (OR = 1.393, p = 0.041.Hemodynamics and morphology were related to rupture status of intracranial aneurysms. Higher IA and LSA were identified as discriminators for rupture status of PCoA aneurysms.

The extrapolation of creep rupture data by PD6605 - An independent case study

Energy Technology Data Exchange (ETDEWEB)

Bolton, J., E-mail: john.bolton@uwclub.net [65 Fisher Avenue, Rugby, Warks CV22 5HW (United Kingdom)

2011-04-15

The worked example presented in BSI document PD6605-1:1998, to illustrate the selection, validation and extrapolation of a creep rupture model using statistical analysis, was independently examined. Alternative rupture models were formulated and analysed by the same statistical methods, and were shown to represent the test data more accurately than the original model. Median rupture lives extrapolated from the original and alternative models were found to diverge widely under some conditions of practical interest. The tests prescribed in PD6605 and employed to validate the original model were applied to the better of the alternative models. But the tests were unable to discriminate between the two, demonstrating that these tests fail to ensure reliability in extrapolation. The difficulties of determining when a model is sufficiently reliable for use in extrapolation are discussed and some proposals are made.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms

OpenAIRE

Lv, Nan; Wang, Chi; Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

Background and Purpose The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. Materials and Methods In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemo...

Severe accident analysis of a steam generator tube rupture accident using MAAP-CANDU to support level 2 PSA for the Point Lepreau Generating Station Refurbishment Project

Energy Technology Data Exchange (ETDEWEB)

Petoukhov, S.M.; Brown, M.J. [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

2015-07-01

A Level 2 Probabilistic Safety Assessment was performed for the Point Lepreau Generating Station. The MAAP-CANDU code was used to simulate the progression of postulated severe core damage accidents and fission product releases. This paper discusses the results for the reference case of the Steam Generator Tube Rupture initiating event. The reference case, dictated by the Level 2 Probabilistic Safety Assessment, was extreme and assumed most safety-related plant systems were not available: all steam generator feedwater; the emergency water supply; the moderator, shield and shutdown cooling systems; and all stages of emergency core cooling. The reference case also did not credit any post Fukushima lessons or any emergency mitigating equipment. The reference simulation predicted severe core damage beginning at 3.7 h, containment failure at 6.4 h, moderator boil off by 8.2 h, and calandria vessel failure at 42 h. A total release of 5.3% of the initial inventory of radioactive isotopes of Cs, Rb and I was predicted by the end of the simulation (139 h). Almost all noble gas fission products were released to the environment, primarily after the containment failure. No hydrogen/carbon monoxide burning was predicted. (author)

Directly Estimating Earthquake Rupture Area using Second Moments to Reduce the Uncertainty in Stress Drop

Science.gov (United States)

McGuire, Jeffrey J.; Kaneko, Yoshihiro

2018-06-01

The key kinematic earthquake source parameters: rupture velocity, duration and area, shed light on earthquake dynamics, provide direct constraints on stress-drop, and have implications for seismic hazard. However, for moderate and small earthquakes, these parameters are usually poorly constrained due to limitations of the standard analysis methods. Numerical experiments by Kaneko and Shearer [2014,2015] demonstrated that standard spectral fitting techniques can lead to roughly 1 order of magnitude variation in stress-drop estimates that do not reflect the actual rupture properties even for simple crack models. We utilize these models to explore an alternative approach where we estimate the rupture area directly. For the suite of models, the area averaged static stress drop is nearly constant for models with the same underlying friction law, yet corner frequency based stress-drop estimates vary by a factor of 5-10 even for noise free data. Alternatively, we simulated inversions for the rupture area as parameterized by the second moments of the slip distribution. A natural estimate for the rupture area derived from the second moments is A=πLcWc, where Lc and Wc are the characteristic rupture length and width. This definition yields estimates of stress drop that vary by only 10% between the models but are slightly larger than the true area-averaged values. We simulate inversions for the second moments for the various models and find that the area can be estimated well when there are at least 15 available measurements of apparent duration at a variety of take-off angles. The improvement compared to azimuthally-averaged corner-frequency based approaches results from the second moments accounting for directivity and removing the assumption of a circular rupture area, both of which bias the standard approach. We also develop a new method that determines the minimum and maximum values of rupture area that are consistent with a particular dataset at the 95% confidence

Bond rupture between colloidal particles with a depletion interaction

Energy Technology Data Exchange (ETDEWEB)

Whitaker, Kathryn A.; Furst, Eric M., E-mail: furst@udel.edu [Department of Chemical and Biomolecular Engineering and Center for Molecular and Engineering Thermodynamics, University of Delaware, Newark, Delaware 19716 (United States)

2016-05-15

The force required to break the bonds of a depletion gel is measured by dynamically loading pairs of colloidal particles suspended in a solution of a nonadsorbing polymer. Sterically stabilized poly(methyl methacrylate) colloids that are 2.7 μm diameter are brought into contact in a solvent mixture of cyclohexane-cyclohexyl bromide and polystyrene polymer depletant. The particle pairs are subject to a tensile load at a constant loading rate over many approach-retraction cycles. The stochastic nature of the thermal rupture events results in a distribution of bond rupture forces with an average magnitude and variance that increases with increasing depletant concentration. The measured force distribution is described by the flux of particle pairs sampling the energy barrier of the bond interaction potential based on the Asakura–Oosawa depletion model. A transition state model demonstrates the significance of lubrication hydrodynamic interactions and the effect of the applied loading rate on the rupture force of bonds in a depletion gel.

Morphological and Hemodynamic Discriminators for Rupture Status in Posterior Communicating Artery Aneurysms.

Science.gov (United States)

Lv, Nan; Wang, Chi; Karmonik, Christof; Fang, Yibin; Xu, Jinyu; Yu, Ying; Cao, Wei; Liu, Jianmin; Huang, Qinghai

2016-01-01

The conflicting findings of previous morphological and hemodynamic studies on intracranial aneurysm rupture may be caused by the relatively small sample sizes and the variation in location of the patient-specific aneurysm models. We aimed to determine the discriminators for aneurysm rupture status by focusing on only posterior communicating artery (PCoA) aneurysms. In 129 PCoA aneurysms (85 ruptured, 44 unruptured), clinical, morphological and hemodynamic characteristics were compared between the ruptured and unruptured cases. Multivariate logistic regression analysis was performed to determine the discriminators for rupture status of PCoA aneurysms. While univariate analyses showed that the size of aneurysm dome, aspect ratio (AR), size ratio (SR), dome-to-neck ratio (DN), inflow angle (IA), normalized wall shear stress (NWSS) and percentage of low wall shear stress area (LSA) were significantly associated with PCoA aneurysm rupture status. With multivariate analyses, significance was only retained for higher IA (OR = 1.539, p PCoA aneurysms.

Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

Science.gov (United States)

Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

2007-01-01

Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

The Computational Fluid Dynamics Rupture Challenge 2013--Phase II: Variability of Hemodynamic Simulations in Two Intracranial Aneurysms.

Science.gov (United States)

Berg, Philipp; Roloff, Christoph; Beuing, Oliver; Voss, Samuel; Sugiyama, Shin-Ichiro; Aristokleous, Nicolas; Anayiotos, Andreas S; Ashton, Neil; Revell, Alistair; Bressloff, Neil W; Brown, Alistair G; Chung, Bong Jae; Cebral, Juan R; Copelli, Gabriele; Fu, Wenyu; Qiao, Aike; Geers, Arjan J; Hodis, Simona; Dragomir-Daescu, Dan; Nordahl, Emily; Bora Suzen, Yildirim; Owais Khan, Muhammad; Valen-Sendstad, Kristian; Kono, Kenichi; Menon, Prahlad G; Albal, Priti G; Mierka, Otto; Münster, Raphael; Morales, Hernán G; Bonnefous, Odile; Osman, Jan; Goubergrits, Leonid; Pallares, Jordi; Cito, Salvatore; Passalacqua, Alberto; Piskin, Senol; Pekkan, Kerem; Ramalho, Susana; Marques, Nelson; Sanchi, Stéphane; Schumacher, Kristopher R; Sturgeon, Jess; Švihlová, Helena; Hron, Jaroslav; Usera, Gabriel; Mendina, Mariana; Xiang, Jianping; Meng, Hui; Steinman, David A; Janiga, Gábor

2015-12-01

prescribed. In order to compare the computational results of one representative group with experimental results, steady-flow measurements using particle image velocimetry (PIV) were carried out in a silicone model of one of the provided aneurysms. Approximately 80% of the participating groups generated similar results. Both velocity and pressure computations were in good agreement with each other for cycle-averaged and peak-systolic predictions. Most apparent "outliers" (results that stand out of the collective) were observed to have underestimated velocity levels compared to the majority of solutions, but nevertheless identified comparable flow structures. In only two cases, the results deviate by over 35% from the mean solution of all the participants. Results of steady CFD simulations of the representative group and PIV experiments were in good agreement. The study demonstrated that while a range of numerical schemes, mesh resolution, and solvers was used, similar flow predictions were observed in the majority of cases. To further validate the computational results, it is suggested that time-dependent measurements should be conducted in the future. However, it is recognized that this study does not include the biological aspects of the aneurysm, which needs to be considered to be able to more precisely identify the specific rupture risk of an intracranial aneurysm.

Forecasting the Rupture Directivity of Large Earthquakes: Centroid Bias of the Conditional Hypocenter Distribution

Science.gov (United States)

Donovan, J.; Jordan, T. H.

2012-12-01

Forecasting the rupture directivity of large earthquakes is an important problem in probabilistic seismic hazard analysis (PSHA), because directivity is known to strongly influence ground motions. We describe how rupture directivity can be forecast in terms of the "conditional hypocenter distribution" or CHD, defined to be the probability distribution of a hypocenter given the spatial distribution of moment release (fault slip). The simplest CHD is a uniform distribution, in which the hypocenter probability density equals the moment-release probability density. For rupture models in which the rupture velocity and rise time depend only on the local slip, the CHD completely specifies the distribution of the directivity parameter D, defined in terms of the degree-two polynomial moments of the source space-time function. This parameter, which is zero for a bilateral rupture and unity for a unilateral rupture, can be estimated from finite-source models or by the direct inversion of seismograms (McGuire et al., 2002). We compile D-values from published studies of 65 large earthquakes and show that these data are statistically inconsistent with the uniform CHD advocated by McGuire et al. (2002). Instead, the data indicate a "centroid biased" CHD, in which the expected distance between the hypocenter and the hypocentroid is less than that of a uniform CHD. In other words, the observed directivities appear to be closer to bilateral than predicted by this simple model. We discuss the implications of these results for rupture dynamics and fault-zone heterogeneities. We also explore their PSHA implications by modifying the CyberShake simulation-based hazard model for the Los Angeles region, which assumed a uniform CHD (Graves et al., 2011).

Depth varying rupture properties during the 2015 Mw 7.8 Gorkha (Nepal) earthquake

Science.gov (United States)

Yue, Han; Simons, Mark; Duputel, Zacharie; Jiang, Junle; Fielding, Eric; Liang, Cunren; Owen, Susan; Moore, Angelyn; Riel, Bryan; Ampuero, Jean Paul; Samsonov, Sergey V.

2017-09-01

On April 25th 2015, the Mw 7.8 Gorkha (Nepal) earthquake ruptured a portion of the Main Himalayan Thrust underlying Kathmandu and surrounding regions. We develop kinematic slip models of the Gorkha earthquake using both a regularized multi-time-window (MTW) approach and an unsmoothed Bayesian formulation, constrained by static and high rate GPS observations, synthetic aperture radar (SAR) offset images, interferometric SAR (InSAR), and teleseismic body wave records. These models indicate that Kathmandu is located near the updip limit of fault slip and approximately 20 km south of the centroid of fault slip. Fault slip propagated unilaterally along-strike in an ESE direction for approximately 140 km with a 60 km cross-strike extent. The deeper portions of the fault are characterized by a larger ratio of high frequency (0.03-0.2 Hz) to low frequency slip than the shallower portions. From both the MTW and Bayesian results, we can resolve depth variations in slip characteristics, with higher slip roughness, higher rupture velocity, longer rise time and higher complexity of subfault source time functions in the deeper extents of the rupture. The depth varying nature of rupture characteristics suggests that the up-dip portions are characterized by relatively continuous rupture, while the down-dip portions may be better characterized by a cascaded rupture. The rupture behavior and the tectonic setting indicate that the earthquake may have ruptured both fully seismically locked and a deeper transitional portions of the collision interface, analogous to what has been seen in major subduction zone earthquakes.

MRI of tibialis anterior tendon rupture

International Nuclear Information System (INIS)

Gallo, Robert A.; DeMeo, Patrick J.; Kolman, Brett H.; Daffner, Richard H.; Sciulli, Robert L.; Roberts, Catherine C.

2004-01-01

Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58-67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of the tendon, and excess fluid in the tendon sheath. One patient demonstrated a partial tear showing an attenuated tendon with increased surrounding fluid. Although rupture of the tibialis anterior tendon is a rarely reported entity, MRI is a useful modality in the definitive detection and characterization of tibialis anterior tendon ruptures. (orig.)

Monte Carlo simulation of liquid bridge rupture: Application to lung physiology

Science.gov (United States)

Alencar, Adriano M.; Wolfe, Elie; Buldyrev, Sergey V.

2006-08-01

In the course of certain lung diseases, the surface properties and the amount of fluids coating the airways changes and liquid bridges may form in the small airways blocking the flow of air, impairing gas exchange. During inhalation, these liquid bridges may rupture due to mechanical instability and emit a discrete sound event called pulmonary crackle, which can be heard using a simple stethoscope. We hypothesize that this sound is a result of the acoustical release of energy that had been stored in the surface of liquid bridges prior to its rupture. We develop a lattice gas model capable of describing these phenomena. As a step toward modeling this process, we address a simpler but related problem, that of a liquid bridge between two planar surfaces. This problem has been analytically solved and we use this solution as a validation of the lattice gas model of the liquid bridge rupture. Specifically, we determine the surface free energy and critical stability conditions in a system containing a liquid bridge of volume Ω formed between two parallel planes, separated by a distance 2h , with a contact angle Θ using both Monte Carlo simulation of a lattice gas model and variational calculus based on minimization of the surface area with the volume and the contact angle constraints. In order to simulate systems with different contact angles, we vary the parameters between the constitutive elements of the lattice gas. We numerically and analytically determine the phase diagram of the system as a function of the dimensionless parameters hΩ-1/3 and Θ . The regions of this phase diagram correspond to the mechanical stability and thermodynamical stability of the liquid bridge. We also determine the conditions for the symmetrical versus asymmetrical rupture of the bridge. We numerically and analytically compute the release of free energy during rupture. The simulation results are in agreement with the analytical solution. Furthermore, we discuss the results in connection

A spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3‐ETAS): Toward an operational earthquake forecast

Science.gov (United States)

Field, Edward; Milner, Kevin R.; Hardebeck, Jeanne L.; Page, Morgan T.; van der Elst, Nicholas; Jordan, Thomas H.; Michael, Andrew J.; Shaw, Bruce E.; Werner, Maximillan J.

2017-01-01

We, the ongoing Working Group on California Earthquake Probabilities, present a spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3), with the goal being to represent aftershocks, induced seismicity, and otherwise triggered events as a potential basis for operational earthquake forecasting (OEF). Specifically, we add an epidemic‐type aftershock sequence (ETAS) component to the previously published time‐independent and long‐term time‐dependent forecasts. This combined model, referred to as UCERF3‐ETAS, collectively represents a relaxation of segmentation assumptions, the inclusion of multifault ruptures, an elastic‐rebound model for fault‐based ruptures, and a state‐of‐the‐art spatiotemporal clustering component. It also represents an attempt to merge fault‐based forecasts with statistical seismology models, such that information on fault proximity, activity rate, and time since last event are considered in OEF. We describe several unanticipated challenges that were encountered, including a need for elastic rebound and characteristic magnitude–frequency distributions (MFDs) on faults, both of which are required to get realistic triggering behavior. UCERF3‐ETAS produces synthetic catalogs of M≥2.5 events, conditioned on any prior M≥2.5 events that are input to the model. We evaluate results with respect to both long‐term (1000 year) simulations as well as for 10‐year time periods following a variety of hypothetical scenario mainshocks. Although the results are very plausible, they are not always consistent with the simple notion that triggering probabilities should be greater if a mainshock is located near a fault. Important factors include whether the MFD near faults includes a significant characteristic earthquake component, as well as whether large triggered events can nucleate from within the rupture zone of the mainshock. Because UCERF3‐ETAS has many sources of uncertainty, as

Slow rupture of frictional interfaces

OpenAIRE

Sinai, Yohai Bar; Brener, Efim A.; Bouchbinder, Eran

2011-01-01

The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not comple...

Determine Earthquake Rupture Directivity Using Taiwan TSMIP Strong Motion Waveforms

Science.gov (United States)

Chang, Kaiwen; Chi, Wu-Cheng; Lai, Ying-Ju; Gung, YuanCheng

2013-04-01

Inverting seismic waveforms for the finite fault source parameters is important for studying the physics of earthquake rupture processes. It is also significant to image seismogenic structures in urban areas. Here we analyze the finite-source process and test for the causative fault plane using the accelerograms recorded by the Taiwan Strong-Motion Instrumentation Program (TSMIP) stations. The point source parameters for the mainshock and aftershocks were first obtained by complete waveform moment tensor inversions. We then use the seismograms generated by the aftershocks as empirical Green's functions (EGFs) to retrieve the apparent source time functions (ASTFs) of near-field stations using projected Landweber deconvolution approach. The method for identifying the fault plane relies on the spatial patterns of the apparent source time function durations which depend on the angle between rupture direction and the take-off angle and azimuth of the ray. These derived duration patterns then are compared with the theoretical patterns, which are functions of the following parameters, including focal depth, epicentral distance, average crustal 1D velocity, fault plane attitude, and rupture direction on the fault plane. As a result, the ASTFs derived from EGFs can be used to infer the ruptured fault plane and the rupture direction. Finally we used part of the catalogs to study important seismogenic structures in the area near Chiayi, Taiwan, where a damaging earthquake has occurred about a century ago. The preliminary results show a strike-slip earthquake on 22 October 1999 (Mw 5.6) has ruptured unilaterally toward SSW on a sub-vertical fault. The procedure developed from this study can be applied to other strong motion waveforms recorded from other earthquakes to better understand their kinematic source parameters.

Amplification of tsunami heights by delayed rupture of great earthquakes along the Nankai trough

Science.gov (United States)

Imai, K.; Satake, K.; Furumura, T.

2010-04-01

We investigated the effect of delayed rupture of great earthquakes along the Nankai trough on tsunami heights on the Japanese coast. As the tsunami source, we used a model of the 1707 Hoei earthquake, which consists of four segments: Tokai, Tonankai, and two Nankai segments. We first searched for the worst case, in terms of coastal tsunami heights, of rupture delay time on each segment, on the basis of superposition principle for the linear long wave theory. When the rupture starts on the Tonankai segment, followed by rupture on the Tokai segment 21 min later, as well as the eastern and western Nankai segments 15 and 28 min later, respectively, the average coastal tsunami height becomes the largest. To quantify the tsunami amplification, we compared the coastal tsunami heights from the delayed rupture with those from the simultaneous rupture model. Along the coasts of the sea of Hyu'uga and in the Bungo Channel, the tsunami heights become significantly amplified (>1.4 times larger) relative to the simultaneous rupture. Along the coasts of Tosa Bay and in the Kii Channel, the tsunami heights become amplified about 1.2 times. Along the coasts of the sea of Kumano and Ise Bay, and the western Enshu coast, the tsunami heights become slightly smaller for the delayed rupture. Along the eastern Enshu coast, the coast of Suruga Bay, and the west coast of Sagami Bay, the tsunami heights become amplified about 1.1 times.

Earthquake rupture process recreated from a natural fault surface

Science.gov (United States)

Parsons, Thomas E.; Minasian, Diane L.

2015-01-01

What exactly happens on the rupture surface as an earthquake nucleates, spreads, and stops? We cannot observe this directly, and models depend on assumptions about physical conditions and geometry at depth. We thus measure a natural fault surface and use its 3D coordinates to construct a replica at 0.1 m resolution to obviate geometry uncertainty. We can recreate stick-slip behavior on the resulting finite element model that depends solely on observed fault geometry. We clamp the fault together and apply steady state tectonic stress until seismic slip initiates and terminates. Our recreated M~1 earthquake initiates at contact points where there are steep surface gradients because infinitesimal lateral displacements reduce clamping stress most efficiently there. Unclamping enables accelerating slip to spread across the surface, but the fault soon jams up because its uneven, anisotropic shape begins to juxtapose new high-relief sticking points. These contacts would ultimately need to be sheared off or strongly deformed before another similar earthquake could occur. Our model shows that an important role is played by fault-wall geometry, though we do not include effects of varying fluid pressure or exotic rheologies on the fault surfaces. We extrapolate our results to large fault systems using observed self-similarity properties, and suggest that larger ruptures might begin and end in a similar way, though the scale of geometrical variation in fault shape that can arrest a rupture necessarily scales with magnitude. In other words, fault segmentation may be a magnitude dependent phenomenon and could vary with each subsequent rupture.

Rupture Dynamics along Thrust Dipping Fault: Inertia Effects due to Free Surface Wave Interactions

Science.gov (United States)

Vilotte, J. P.; Scala, A.; Festa, G.

2017-12-01

We numerically investigate the dynamic interaction between free surface and up-dip, in-plane rupture propagation along thrust faults, under linear slip-weakening friction. With reference to shallow along-dip rupture propagation during large subduction earthquakes, we consider here low dip-angle fault configurations with fixed strength excess and depth-increasing initial stress. In this configuration, the rupture undergoes a break of symmetry with slip-induced normal stress perturbations triggered by the interaction with reflected waves from the free surface. We found that both body-waves - behind the crack front - and surface waves - at the crack front - can trigger inertial effects. When waves interact with the rupture before this latter reaches its asymptotic speed, the rupture can accelerate toward the asymptotic speed faster than in the unbounded symmetric case, as a result of these inertial effects. Moreover, wave interaction at the crack front also affects the slip rate generating large ground motion on the hanging wall. Imposing the same initial normal stress, frictional strength and stress drop while varying the static friction coefficient we found that the break of symmetry makes the rupture dynamics dependent on the absolute value of friction. The higher the friction the stronger the inertial effect both in terms of rupture acceleration and slip amount. When the contact condition allows the fault interface to open close to the free surface, the length of the opening zone is shown to depend on the propagation length, the initial normal stress and the static friction coefficient. These new results are shown to agree with analytical results of rupture propagation in bounded media, and open new perspectives for understanding the shallow rupture of large subduction earthquakes and tsunami sources.

Computational simulation of the creep-rupture process in filamentary composite materials

Science.gov (United States)

Slattery, Kerry T.; Hackett, Robert M.

1991-01-01

A computational simulation of the internal damage accumulation which causes the creep-rupture phenomenon in filamentary composite materials is developed. The creep-rupture process involves complex interactions between several damage mechanisms. A statistically-based computational simulation using a time-differencing approach is employed to model these progressive interactions. The finite element method is used to calculate the internal stresses. The fibers are modeled as a series of bar elements which are connected transversely by matrix elements. Flaws are distributed randomly throughout the elements in the model. Load is applied, and the properties of the individual elements are updated at the end of each time step as a function of the stress history. The simulation is continued until failure occurs. Several cases, with different initial flaw dispersions, are run to establish a statistical distribution of the time-to-failure. The calculations are performed on a supercomputer. The simulation results compare favorably with the results of creep-rupture experiments conducted at the Lawrence Livermore National Laboratory.

Using finite-difference waveform modeling to better understand rupture kinematics and path effects in ground motion modeling: an induced seismicity case study at the Groningen Gas field

Science.gov (United States)

Zurek, B.; Burnett, W. A.; deMartin, B.

2017-12-01

Ground motion models (GMMs) have historically been used as input in the development of probabilistic seismic hazard analysis (PSHA) and as an engineering tool to assess risk in building design. Generally these equations are developed from empirical analysis of observations that come from fairly complete catalogs of seismic events. One of the challenges when doing a PSHA analysis in a region where earthquakes are anthropogenically induced is that the catalog of observations is not complete enough to come up with a set of equations to cover all expected outcomes. For example, PSHA analysis at the Groningen gas field, an area of known induced seismicity, requires estimates of ground motions from tremors up to a maximum magnitude of 6.5 ML. Of the roughly 1300 recordable earthquakes the maximum observed magnitude to date has been 3.6ML. This paper is part of a broader study where we use a deterministic finite-difference wave-form modeling tool to compliment the traditional development of GMMs. Of particular interest is the sensitivity of the GMM's to uncertainty in the rupture process and how this scales to larger magnitude events that have not been observed. A kinematic fault rupture model is introduced to our waveform simulations to test the sensitivity of the GMMs to variability in the fault rupture process that is physically consistent with observations. These tests will aid in constraining the degree of variability in modeled ground motions due to a realistic range of fault parameters and properties. From this study it is our conclusion that in order to properly capture the uncertainty of the GMMs with magnitude up-scaling one needs to address the impact of uncertainty in the near field (risk. Further, by investigating and constraining the range of fault rupture scenarios and earthquake magnitudes on ground motion models, hazard and risk analysis in regions with incomplete earthquake catalogs, such as the Groningen gas field, can be better understood.

Pseudodynamic Source Characterization for Strike-Slip Faulting Including Stress Heterogeneity and Super-Shear Ruptures

KAUST Repository

Mena, B.; Dalguer, L. A.; Mai, Paul Martin

2012-01-01

. (2004), we propose new relationships for PD models for moderate‐to‐large strike‐slip earthquakes that include local supershear rupture speed due to stress heterogeneities. We conduct dynamic rupture simulations using stochastic initial stress

Aortic ruptures in seat belt wearers.

Science.gov (United States)

Arajärvi, E; Santavirta, S; Tolonen, J

1989-09-01

Several investigations have indicated that rupture of the thoracic aorta is one of the leading causes of immediate death in victims of road traffic accidents. In Finland in 1983, 92% of front-seat passengers were seat belt wearers on highways and 82% in build-up areas. The mechanisms of rupture of the aorta have been intensively investigated, but the relationship between seat belt wearing and injury mechanisms leading to aortic rupture is still largely unknown. This study comprises 4169 fatally injured victims investigated by the Boards of Traffic Accident Investigation of Insurance Companies during the period 1972 to 1985. Chest injuries were recorded as the main cause of death in 1121 (26.9%) victims, 207 (5.0%) of those victims having worn a seat belt. Aortic ruptures were found at autopsy in 98 victims and the exact information of the location of the aortic tears was available in 68. For a control group, we analyzed 72 randomly chosen unbelted victims who had a fatal aortic rupture in similar accidents. The location of the aortic rupture in unbelted victims was more often in the ascending aorta, especially in drivers, whereas in seat belt wearers the distal descending aorta was statistically more often ruptured, especially in right-front passengers (p less than 0.05). The steering wheel predominated statistically as the part of the car estimated to have caused the injury in unbelted victims (37/72), and some interior part of the car was the most common cause of fatal thoracic impacts in seat belt wearers (48/68) (p less than 0.001). The mechanism of rupture of the aorta in the classic site just distal to the subclavian artery seems to be rapid deceleration, although complex body movements are also responsible in side impact collisions. The main mechanism leading to rupture of the ascending aorta seems to be severe blow to the bony thorax. This also often causes associated thoracic injuries, such as heart rupture and sternal fracture. Injuries in the ascending

Ruptured cornual pregnancy

International Nuclear Information System (INIS)

Hussain, M.; Yasmeen, H.; Noorani, K.

2003-01-01

A case of ruptured cornual pregnancy is presented here. The patient presented with history of 30 weeks gestational amenorrhoea and pain in the lower abdomen and epigastrium for the last seven days. Ultrasound revealed a 29 weeks abdominal pregnancy with blood in the pelvic cavity. On laparotomy; there was a ruptured right cornual pregnancy, treated cornual resection and uterine repair. An alive male baby of one kg weight was delivered from the resected cornua of the uterus. (author)

Empirical Relationships Among Magnitude and Surface Rupture Characteristics of Strike-Slip Faults: Effect of Fault (System) Geometry and Observation Location, Dervided From Numerical Modeling

Science.gov (United States)

Zielke, O.; Arrowsmith, J.

2007-12-01

In order to determine the magnitude of pre-historic earthquakes, surface rupture length, average and maximum surface displacement are utilized, assuming that an earthquake of a specific size will cause surface features of correlated size. The well known Wells and Coppersmith (1994) paper and other studies defined empirical relationships between these and other parameters, based on historic events with independently known magnitude and rupture characteristics. However, these relationships show relatively large standard deviations and they are based only on a small number of events. To improve these first-order empirical relationships, the observation location relative to the rupture extent within the regional tectonic framework should be accounted for. This however cannot be done based on natural seismicity because of the limited size of datasets on large earthquakes. We have developed the numerical model FIMozFric, based on derivations by Okada (1992) to create synthetic seismic records for a given fault or fault system under the influence of either slip- or stress boundary conditions. Our model features A) the introduction of an upper and lower aseismic zone, B) a simple Coulomb friction law, C) bulk parameters simulating fault heterogeneity, and D) a fault interaction algorithm handling the large number of fault patches (typically 5,000-10,000). The joint implementation of these features produces well behaved synthetic seismic catalogs and realistic relationships among magnitude and surface rupture characteristics which are well within the error of the results by Wells and Coppersmith (1994). Furthermore, we use the synthetic seismic records to show that the relationships between magntiude and rupture characteristics are a function of the observation location within the regional tectonic framework. The model presented here can to provide paleoseismologists with a tool to improve magnitude estimates from surface rupture characteristics, by incorporating the

Creep and creep-rupture behavior of Alloy 718

International Nuclear Information System (INIS)

Brinkman, C.R.; Booker, M.K.; Ding, J.L.

1991-01-01

Data obtained from creep and creep-rupture tests conducted on 18 heats of Alloy 718 were used to formulate models for predicting high temperature time dependent behavior of this alloy. Creep tests were conducted on specimens taken from a number of commercial product forms including plate, bar, and forgoing material that had been procured and heat treated in accordance with ASTM specifications B-670 or B-637. Data were obtained over the temperature range of 427 to 760 degree C ad at test times to about 87,000 h. Comparisons are given between experimental data and the analytical models. The analytical models for creep-rupture included one based on lot-centering regression analysis and two based on the Minimum Commitment Method. A ''master'' curve approach was used to develop and equation for estimating creep deformation up to the onset of tertiary creep. 11 refs., 13 figs

Triple Achilles Tendon Rupture: Case Report.

Science.gov (United States)

Saxena, Amol; Hofer, Deann

We present a case report with 1-year follow-up data of a 57-year-old male soccer referee who had sustained an acute triple Achilles tendon rupture injury during a game. His triple Achilles tendon rupture consisted of a rupture of the proximal watershed region, a rupture of the main body (mid-watershed area), and an avulsion-type rupture of insertional calcific tendinosis. The patient was treated surgically with primary repair of the tendon, including tenodesis with anchors. Postoperative treatment included non-weightbearing for 4 weeks and protected weightbearing until 10 weeks postoperative, followed by formal physical therapy, which incorporated an "antigravity" treadmill. The patient was able to return to full activity after 26 weeks, including running and refereeing, without limitations. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Electrowetting on dielectric: experimental and model study of oil conductivity on rupture voltage

Science.gov (United States)

Zhao, Qing; Tang, Biao; Dong, Baoqin; Li, Hui; Zhou, Rui; Guo, Yuanyuan; Dou, Yingying; Deng, Yong; Groenewold, Jan; Henzen, Alexander Victor; Zhou, Guofu

2018-05-01

Electrowetting on dielectric devices uses a conducting (water) and insulating (oil) liquid phase in conjunction on a dielectric layer. In these devices, the wetting properties of the liquid phases can be manipulated by applying an electric field. The electric field can rupture the initially flat oil film and promotes further dewetting of the oil. Here, we investigate a problem in the operation of electrowetting on dielectric caused by a finite conductivity of the oil. In particular, we find that the voltage at which the oil film ruptures is sensitive to the application of relatively low DC voltages prior to switching. Here, we systematically investigate this dependence using controlled driving schemes. The mechanism behind these history effects point to charge transport processes in the dielectric and the oil, which can be modeled and characterized by a decay time. To quantify the effects the typical response timescales have been measured with a high-speed video camera. The results have been reproduced in simulations. In addition, a simplified yet accurate equivalent circuit model is developed to analyze larger data sets more conveniently. The experimental data support the hypothesis that each pixel can be characterized by a single decay time. We studied an ensemble of pixels and found that they showed a rather broad distribution of decay times with an average value of about 440 ms. This decay time can be interpreted as a discharge timescale of the oil, not to be confused with discharge of the entire system which is generally much faster (<1 ms). Through the equivalent circuit model, we also found that variations in the fluoropolymer (FP) conductivity cannot explain the distribution of decay times, while variations in oil conductivity can.

Rupture disc opening property for using pipe rupture test in JAERI

International Nuclear Information System (INIS)

Kato, Rokuro

1983-03-01

In the Mechanical Strength and Structure Lab of JAERI there are being performed pipe break tests which are a postulated instantaneous guillotine break of the primary coolant piping in nuclear power plants. The test being performed are pipe whip tests and jet discharging tests. The bursting of the rupture disc is initiated by an electrical arc and is concluded by the internal pressure. Because the time characteristics during the opening of the rupture disc affects the dynamic thrust force of the pipe, it is necessary to measure these time characteristics. However, it is difficult to measure the conditions during this continuous opening because at the same time of the opening the high temperature and high pressure water is flashing. Therefore, the rupture disc opening was postulated on the measuring of the effective opening characteristics with electric contraction terminals which were attached to the inner surface of the test pipe downstream of the rupture disc and were extended toward the pipe centerline in a ring whose area is about 60 % of the area of the pipe flow sectional area. The measurement voltage was recorded when the data recorder was started in sequence with the electrical arc release from a trigger signal. As a result, it is evident that under high temperature and high pressure water the effective opening time is delayed by a few milliseconds. (author)

Rupture of the tuberosity of the tibia

International Nuclear Information System (INIS)

Schild, H.; Schwarzkopf, W.

1981-01-01

Ruptures of the tuberosity of the tibia occur particularly in male adolescents, although on the whole they represent a rare type of injury. The article discusses classification into different types according to Watson-Jones as well as exemplary models, traumatology, clinic and therapy. (orig.) [de

Assessment of RELAP5/MOD3.1 with the LSTF SB-SG-06 experiment simulating a steam generator tube rupture transient

International Nuclear Information System (INIS)

Seul, K.W.; Bang, Y.S.; Lee, S.; Kim, H.J.

1996-09-01

The objective of the present work is to identify the predictability of RELAP5/MOD3.1 regarding thermal-hydraulic behavior during a steam generator tube rupture (SGTR). To evaluate the computed results, LSTF SB-SG-06 test data simulating the SGTR that occurred at the Mihama Unit 2 in 1991 are used. Also, some sensitivity studies of the code change in RELAP5, the break simulation model, and the break valve discharge coefficient are performed. The calculation results indicate that the RELAP5/MOD3.1 code predicted well the sequence of events and the major phenomena during the transient, such as the asymmetric loop behavior, reactor coolant system (RCS) cooldown and heat transfer by natural circulation, the primary and secondary system depressurization by the pressurizer auxiliary spray and the steam dump using the intact loop steam generator (SG) relief valve, and so on. However, there are some differences from the experimental data in the number of the relief valve cycling in the affected SG, and the flow regime of the hot leg with the pressurizer, and the break flow rates. Finally, the calculation also indicates that the coolant in the core could remain in a subcooled state as a result of the heat transfer caused by the natural circulation flow even if the reactor coolant pumps (RCPs) turned off and that the affected SG could be properly isolated to minimize the radiological release after the SGTR

Assessment of RELAP5/MOD3.1 with the LSTF SB-SG-06 experiment simulating a steam generator tube rupture transient

Energy Technology Data Exchange (ETDEWEB)

Seul, K.W.; Bang, Y.S.; Lee, S.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)

1996-09-01

The objective of the present work is to identify the predictability of RELAP5/MOD3.1 regarding thermal-hydraulic behavior during a steam generator tube rupture (SGTR). To evaluate the computed results, LSTF SB-SG-06 test data simulating the SGTR that occurred at the Mihama Unit 2 in 1991 are used. Also, some sensitivity studies of the code change in RELAP5, the break simulation model, and the break valve discharge coefficient are performed. The calculation results indicate that the RELAP5/MOD3.1 code predicted well the sequence of events and the major phenomena during the transient, such as the asymmetric loop behavior, reactor coolant system (RCS) cooldown and heat transfer by natural circulation, the primary and secondary system depressurization by the pressurizer auxiliary spray and the steam dump using the intact loop steam generator (SG) relief valve, and so on. However, there are some differences from the experimental data in the number of the relief valve cycling in the affected SG, and the flow regime of the hot leg with the pressurizer, and the break flow rates. Finally, the calculation also indicates that the coolant in the core could remain in a subcooled state as a result of the heat transfer caused by the natural circulation flow even if the reactor coolant pumps (RCPs) turned off and that the affected SG could be properly isolated to minimize the radiological release after the SGTR.

Splenic rupture masquerading ruptured ectopic pregnancy | Kigbu ...

African Journals Online (AJOL)

The classical triad of presentation of delayed menses, irregular vaginal bleeding and abdominal pain may not be encountered at all! Overwhelming features of abdominal pain, amenorrhea, pallor, abdominal tenderness, shifting dullness with positive pregnancy test gave a clinical diagnosis of ruptured ectopic pregnancy.

MRI findings of achilles tendon rupture

International Nuclear Information System (INIS)

Zhang Xuezhe

2009-01-01

Objective: To evaluate the MRI findings of achilles tendon rupture. Methods: The MRI data of 7 patients with achilles tendon rupture were retrospectively analysed. All 7 patients were male with the age ranging from 34 to 71 years. Routine MR scanning was performed in axial and sagittal planes, including T 1 WI, T 2 WI and a fat suppression MRI (SPIR). Results: Among 7 patients, complete achilles tendon rupture was seen in 6 cases, partial achilles tendon rupture 1 case. The site of tendon disruption were 2.6-11.0 cm( mean 5.4 cm) proximal to the insertion in the calcaneus. The MRI findings of a partial or complete rupture of the achilles tendon included enlarged and thickened achilles tendon (7 cases), wavy lax achilles tendon (2 cases), discontinuity of some or all of its fibers and intratendinous regions of increased signal intensity (7 cases). In the cases of complete tendon rupture, the size of the tendinous gap varied from 3.0-8.0 mm, which was filled with blood and appeared as edema of increase signal intensity on T 2 WI and SPIR. In all 7 patients, MR scanning showed medium signal intensity (7 cases) on T 1 WI, or medium signal intensity (1 cases), medium-high signal intensity (3 cases ), high signal intensity (3 cases) on T 2 WI, and medium-high signal intensity (2 cases), high signal intensity (5 cases) on fat suppression MRI. The preachilles fat pad showed obscure in 6 cases of complete achilles tendon rupture. Conclusion: MRI is an excellent method for revealing achilles tendon rupture and confirming the diagnosis. (authors)

Acute Associations Between Outdoor Temperature and Premature Rupture of Membranes.

Science.gov (United States)

Ha, Sandie; Liu, Danping; Zhu, Yeyi; Sherman, Seth; Mendola, Pauline

2018-03-01

Extreme ambient temperatures have been linked to preterm birth. Preterm premature rupture of membranes is a common precursor to preterm birth but is rarely studied in relation to temperature. We linked 15,381 singleton pregnancies with premature rupture of membranes from a nationwide US obstetrics cohort (2002-2008) to local temperature. Case-crossover analyses compared daily temperature during the week preceding delivery and the day of delivery to 2 control periods, before and after the case period. Conditional logistic regression models calculated the odds ratio (OR) and 95% confidence intervals (CIs) of preterm and term premature rupture of membranes for a 1°C increase in temperature during the warm (May-September) and cold (October-April) season separately after adjusting for humidity, barometric pressure, ozone, and particulate matter. During the warm season, 1°C increase during the week before delivery was associated with a 5% (95% CI, 3%, 6%) increased preterm premature rupture of membranes risk, and a 4% (95% CI, 3%, 5%) increased term premature rupture of membranes risk. During the cold season, 1°C increase was associated with a 2% decreased risk for both preterm (95% CI, 1%, 3%) and term premature rupture of membranes (95% CI, 1%, 3%). The day-specific associations for the week before delivery were similar, but somewhat stronger for days closer to delivery. Relatively small ambient temperature changes were associated with the risk of both preterm and term premature of membranes. Given the adverse consequences of premature rupture of membranes and concerns over global climate change, these findings merit further investigation. See video abstract at, http://links.lww.com/EDE/B312.

3-D dynamic rupture simulations of the 2016 Kumamoto, Japan, earthquake

Science.gov (United States)

Urata, Yumi; Yoshida, Keisuke; Fukuyama, Eiichi; Kubo, Hisahiko

2017-11-01

Using 3-D dynamic rupture simulations, we investigated the 2016 Mw7.1 Kumamoto, Japan, earthquake to elucidate why and how the rupture of the main shock propagated successfully, assuming a complicated fault geometry estimated on the basis of the distributions of the aftershocks. The Mw7.1 main shock occurred along the Futagawa and Hinagu faults. Within 28 h before the main shock, three M6-class foreshocks occurred. Their hypocenters were located along the Hinagu and Futagawa faults, and their focal mechanisms were similar to that of the main shock. Therefore, an extensive stress shadow should have been generated on the fault plane of the main shock. First, we estimated the geometry of the fault planes of the three foreshocks as well as that of the main shock based on the temporal evolution of the relocated aftershock hypocenters. We then evaluated the static stress changes on the main shock fault plane that were due to the occurrence of the three foreshocks, assuming elliptical cracks with constant stress drops on the estimated fault planes. The obtained static stress change distribution indicated that Coulomb failure stress change (ΔCFS) was positive just below the hypocenter of the main shock, while the ΔCFS in the shallow region above the hypocenter was negative. Therefore, these foreshocks could encourage the initiation of the main shock rupture and could hinder the propagation of the rupture toward the shallow region. Finally, we conducted 3-D dynamic rupture simulations of the main shock using the initial stress distribution, which was the sum of the static stress changes caused by these foreshocks and the regional stress field. Assuming a slip-weakening law with uniform friction parameters, we computed 3-D dynamic rupture by varying the friction parameters and the values of the principal stresses. We obtained feasible parameter ranges that could reproduce the characteristic features of the main shock rupture revealed by seismic waveform analyses. We also

3-D Spontaneous Rupture Simulations of the 2016 Kumamoto, Japan, Earthquake

Science.gov (United States)

Urata, Yumi; Yoshida, Keisuke; Fukuyama, Eiichi

2017-04-01

We investigated the M7.3 Kumamoto, Japan, earthquake to illuminate why and how the rupture of the main shock propagated successfully by 3-D dynamic rupture simulations, assuming a complicated fault geometry estimated based on the distributions of aftershocks. The M7.3 main shock occurred along the Futagawa and Hinagu faults. A few days before, three M6-class foreshocks occurred. Their hypocenters were located along by the Hinagu and Futagawa faults and their focal mechanisms were similar to those of the main shock; therefore, an extensive stress shadow can have been generated on the fault plane of the main shock. First, we estimated the geometry of the fault planes of the three foreshocks as well as that of the main shock based on the temporal evolution of relocated aftershock hypocenters. Then, we evaluated static stress changes on the main shock fault plane due to the occurrence of the three foreshocks assuming elliptical cracks with constant stress drops on the estimated fault planes. The obtained static stress change distribution indicated that the hypocenter of the main shock is located on the region with positive Coulomb failure stress change (ΔCFS) while ΔCFS in the shallow region above the hypocenter was negative. Therefore, these foreshocks could encourage the initiation of the main shock rupture and could hinder the rupture propagating toward the shallow region. Finally, we conducted 3-D dynamic rupture simulations of the main shock using the initial stress distribution, which was the sum of the static stress changes by these foreshocks and the regional stress field. Assuming a slip-weakening law with uniform friction parameters, we conducted 3-D dynamic rupture simulations by varying the friction parameters and the values of the principal stresses. We obtained feasible parameter ranges to reproduce the rupture propagation of the main shock consistent with those revealed by seismic waveform analyses. We also demonstrated that the free surface encouraged

Long-term results after repair of ruptured and non-ruptured abdominal aortic aneurysm

Directory of Open Access Journals (Sweden)

Kuzmanović Ilija B.

2004-01-01

Full Text Available INTRODUCTION Abdominal aortic aneurysm can be repaired by elective procedure while asymptomatic, or immediately when it is complicated - mostly due to rupture. Treating abdominal aneurysm electively, before it becomes urgent, has medical and economical reason. Today, the first month mortality after elective operations of the abdominal aorta aneurysm is less than 3%; on the other hand, significant mortality (25%-70% has been recorded in patients operated immediately because of rupture of the abdominal aneurysm. In addition, the costs of elective surgical treatment are significantly lower. OBJECTIVE The objective of this study is to compare long-term survival of patients that underwent elective or immediate repair of abdominal aortic aneurysm (due to rupture, and to find out the factors influencing the long-term survival of these patients. MATERIAL AND METHODS Through retrospective review of prospectively collected data of the Institute for Cardiovascular Diseases of Clinical Center of Serbia, Belgrade, 56 patients that had elective surgery and 35 patients that underwent urgent operation due to rupture of abdominal aneurysm were followed up. Only the patients that survived 30 postoperative days were included in this review, and were followed up (ranging from 2 to 126 months. Electively operated patients were followed during 58.82 months on the average (range 7 to 122, and urgently operated were followed over 52.26 months (range 2 to 126. There was no significant difference of the length of postoperative follow-up between these two groups. RESULTS During this period, out of electively operated and immediately operated patients, 27 and 22 cases died, respectively. There was no significant difference (p>0,05a of long-term survival between these two groups. Obesity and early postoperative complications significantly decreased long-term survival of both electively and immediately operated patients. Graft infection, ventral hernia, aneurysm of

Slip reactivation during the 2011 Tohoku earthquake: Dynamic rupture and ground motion simulations

Science.gov (United States)

Galvez, P.; Dalguer, L. A.

2013-12-01

The 2011 Mw9 Tohoku earthquake generated such as vast geophysical data that allows studying with an unprecedented resolution the spatial-temporal evolution of the rupture process of a mega thrust event. Joint source inversion of teleseismic, near-source strong motion and coseismic geodetic data , e.g [Lee et. al, 2011], reveal an evidence of slip reactivation process at areas of very large slip. The slip of snapshots of this source model shows that after about 40 seconds the big patch above to the hypocenter experienced an additional push of the slip (reactivation) towards the trench. These two possible repeating slip exhibited by source inversions can create two waveform envelops well distinguished in the ground motion pattern. In fact seismograms of the KiK-Net Japanese network contained this pattern. For instance a seismic station around Miyagi (MYGH10) has two main wavefronts separated between them by 40 seconds. A possible physical mechanism to explain the slip reactivation could be a thermal pressurization process occurring in the fault zone. In fact, Kanamori & Heaton, (2000) proposed that for large earthquakes frictional melting and fluid pressurization can play a key role of the rupture dynamics of giant earthquakes. If fluid exists in a fault zone, an increase of temperature can rise up the pore pressure enough to significantly reduce the frictional strength. Therefore, during a large earthquake the areas of big slip persuading strong thermal pressurization may result in a second drop of the frictional strength after reaching a certain value of slip. Following this principle, we adopt for slip weakening friction law and prescribe a certain maximum slip after which the friction coefficient linearly drops down again. The implementation of this friction law has been done in the latest unstructured spectral element code SPECFEM3D, Peter et. al. (2012). The non-planar subduction interface has been taken into account and place on it a big asperity patch inside

Ground Motion Synthetics For Spontaneous Versus Prescribed Rupture On A 45(o) Thrust Fault

Science.gov (United States)

Gottschämmer, E.; Olsen, K. B.

We have compared prescribed (kinematic) and spontaneous dynamic rupture propaga- tion on a 45(o) dipping thrust fault buried up to 5 km in a half-space model, as well as ground motions on the free surface for frequencies less than 1 Hz. The computa- tions are carried out using a 3D finite-difference method with rate-and-state friction on a planar, 20 km by 20 km fault. We use a slip-weakening distance of 15 cm and a slip- velocity weakening distance of 9.2 cm/s, similar to those for the dynamic study for the 1994 M6.7 Northridge earthquake by Nielsen and Olsen (2000) which generated satis- factory fits to selected strong motion data in the San Fernando Valley. The prescribed rupture propagation was designed to mimic that of the dynamic simulation at depth in order to isolate the dynamic free-surface effects. In this way, the results reflect the dy- namic (normal-stress) interaction with the free surface for various depths of burial of the fault. We find that the moment, peak slip and peak sliprate for the rupture breaking the surface are increased by up to 60%, 80%, and 10%, respectively, compared to the values for the scenario buried 5 km. The inclusion of these effects increases the peak displacements and velocities above the fault by factors up 3.4 and 2.9 including the increase in moment due to normal-stress effects at the free surface, and up to 2.1 and 2.0 when scaled to a Northridge-size event with surface rupture. Similar differences were found by Aagaard et al. (2001). Significant dynamic effects on the ground mo- tions include earlier arrival times caused by super-shear rupture velocities (break-out phases), in agreement with the dynamic finite-element simulations by Oglesby et al. (1998, 2000). The presence of shallow low-velocity layers tend to increase the rup- ture time and the sliprate. In particular, they promote earlier transitions to super-shear velocities and decrease the rupture velocity within the layers. Our results suggest that dynamic

Spatiotemporal complexity of 2-D rupture nucleation process observed by direct monitoring during large-scale biaxial rock friction experiments

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Fukuyama, Eiichi; Tsuchida, Kotoyo; Kawakata, Hironori; Yamashita, Futoshi; Mizoguchi, Kazuo; Xu, Shiqing

2018-05-01

We were able to successfully capture rupture nucleation processes on a 2-D fault surface during large-scale biaxial friction experiments using metagabbro rock specimens. Several rupture nucleation patterns have been detected by a strain gauge array embedded inside the rock specimens as well as by that installed along the edge walls of the fault. In most cases, the unstable rupture started just after the rupture front touched both ends of the rock specimen (i.e., when rupture front extended to the entire width of the fault). In some cases, rupture initiated at multiple locations and the rupture fronts coalesced to generate unstable ruptures, which could only be detected from the observation inside the rock specimen. Therefore, we need to carefully examine the 2-D nucleation process of the rupture especially when analyzing the data measured only outside the rock specimen. At least the measurements should be done at both sides of the fault to identify the asymmetric rupture propagation on the fault surface, although this is not perfect yet. In the present experiment, we observed three typical types of the 2-D rupture propagation patterns, two of which were initiated at a single location either close to the fault edge or inside the fault. This initiation could be accelerated by the free surface effect at the fault edge. The third one was initiated at multiple locations and had a rupture coalescence at the middle of the fault. These geometrically complicated rupture initiation patterns are important for understanding the earthquake nucleation process in nature.

Liver Hydatid Cyst with Transdiaphragmatic Rupture and Lung Hydatid Cyst Ruptured into Bronchi and Pleural Space

International Nuclear Information System (INIS)

Arıbaş, Bilgin Kadri; Dingil, Gürbüz; Köroğlu, Mert; Üngül, Ümit; Zaralı, Aliye Ceylan

2011-01-01

The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone–iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

[Simultaneous Traumatic Rupture of Patellar Ligament and Contralateral Rupture of Quadriceps Femoris Muscle].

Science.gov (United States)

Hladký, V; Havlas, V

2017-01-01

Our paper presents a unique case of a 64-year-old patient after a fall, treated with oral antidiabetic drugs for type II diabetes mellitus. Following a series of examinations, a bilateral injury was diagnosed - patellar ligament tear on the right side and rupture of quadriceps femoris muscle on the left side. It is a rare injury, complicated by simultaneous involvement of both knee joints. The used therapy consisted of a bilateral surgery followed by gradual verticalisation, first with the support of a walking frame and later with the use of forearm crutches. During the final examination, the patient demonstrated full flexion at both knees, while an extension deficit of approx. 5 degrees was still present on the left side. The right knee X-ray showed a proper position of the patella after the removal of temporary tension band wire. Although the clinical results of operative treatment of both the patellar ligament rupture and rupture of quadriceps femoris muscle are in most cases good, early operative treatment, proper technique and post-operative rehabilitation are a prerequisite for success. Key words: knee injuries, patellar ligament, quadriceps muscle, rupture.

Tsunami simulations of mega-thrust earthquakes in the Nankai–Tonankai Trough (Japan) based on stochastic rupture scenarios

KAUST Repository

Goda, Katsuichiro

2017-02-23

In this study, earthquake rupture models for future mega-thrust earthquakes in the Nankai–Tonankai subduction zone are developed by incorporating the main characteristics of inverted source models of the 2011 Tohoku earthquake. These scenario ruptures also account for key features of the national tsunami source model for the Nankai–Tonankai earthquake by the Central Disaster Management Council of the Japanese Government. The source models capture a wide range of realistic slip distributions and kinematic rupture processes, reflecting the current best understanding of what may happen due to a future mega-earthquake in the Nankai–Tonankai Trough, and therefore are useful for conducting probabilistic tsunami hazard and risk analysis. A large suite of scenario rupture models is then used to investigate the variability of tsunami effects in coastal areas, such as offshore tsunami wave heights and onshore inundation depths, due to realistic variations in source characteristics. Such investigations are particularly valuable for tsunami hazard mapping and evacuation planning in municipalities along the Nankai–Tonankai coast.

The relative impact of sizing errors on steam generator tube failure probability

International Nuclear Information System (INIS)

Cizelj, L.; Dvorsek, T.

1998-01-01

The Outside Diameter Stress Corrosion Cracking (ODSCC) at tube support plates is currently the major degradation mechanism affecting the steam generator tubes made of Inconel 600. This caused development and licensing of degradation specific maintenance approaches, which addressed two main failure modes of the degraded piping: tube rupture; and excessive leakage through degraded tubes. A methodology aiming at assessing the efficiency of a given set of possible maintenance approaches has already been proposed by the authors. It pointed out better performance of the degradation specific over generic approaches in (1) lower probability of single and multiple steam generator tube rupture (SGTR), (2) lower estimated accidental leak rates and (3) less tubes plugged. A sensitivity analysis was also performed pointing out the relative contributions of uncertain input parameters to the tube rupture probabilities. The dominant contribution was assigned to the uncertainties inherent to the regression models used to correlate the defect size and tube burst pressure. The uncertainties, which can be estimated from the in-service inspections, are further analysed in this paper. The defect growth was found to have significant and to some extent unrealistic impact on the probability of single tube rupture. Since the defect growth estimates were based on the past inspection records they strongly depend on the sizing errors. Therefore, an attempt was made to filter out the sizing errors and to arrive at more realistic estimates of the defect growth. The impact of different assumptions regarding sizing errors on the tube rupture probability was studied using a realistic numerical example. The data used is obtained from a series of inspection results from Krsko NPP with 2 Westinghouse D-4 steam generators. The results obtained are considered useful in safety assessment and maintenance of affected steam generators. (author)

The PSI Artist Project: Aerosol Retention and Accident Management Issues Following a Steam Generator Tube Rupture

International Nuclear Information System (INIS)

Guntay, Salih; Dehbi, Abdel; Suckow, Detlef; Birchley, Jon

2002-01-01

Steam generator tube rupture (SGTR) incidents, such as those, which occurred in various operating pressurized, water reactors in the past, are serious operational concerns and remain among the most risk-dominant events. Although considerable efforts have been spent to understand tube degradation processes, develop improved modes of operation, and take preventative and corrective measures, SGTR incidents cannot be completely ruled out. Under certain conditions, high releases of radionuclides to the environment are possible during design basis accidents (DBA) and severe accidents. The severe accident codes' models for aerosol retention in the secondary side of a steam generator (SG) have not been assessed against any experimental data, which means that the uncertainties in the source term following an un-isolated SGTR concurrent with a severe accident are not currently quantified. The accident management (AM) procedures aim at avoiding or minimizing the release of fission products from the SG. The enhanced retention of activity within the SG defines the effectiveness of the accident management actions for the specific hardware characteristics and accident conditions of concern. A sound database on aerosol retention due to natural processes in the SG is not available, nor is an assessment of the effect of management actions on these processes. Hence, the effectiveness of the AM in SGTR events is not presently known. To help reduce uncertainties relating to SGTR issues, an experimental project, ARTIST (Aerosol Trapping In a Steam generator), has been initiated at the Paul Scherrer Institut to address aerosol and droplet retention in the various parts of the SG. The test section is comprised of a scaled-down tube bundle, a full-size separator and a full-size dryer unit. The project will study phenomena at the separate effect and integral levels and address AM issues in seven distinct phases: Aerosol retention in 1) the broken tube under dry secondary side conditions, 2

Untreated silicone breast implant rupture

DEFF Research Database (Denmark)

Hölmich, Lisbet R; Vejborg, Ilse M; Conrad, Carsten

2004-01-01

Implant rupture is a well-known complication of breast implant surgery that can pass unnoticed by both patient and physician. To date, no prospective study has addressed the possible health implications of silicone breast implant rupture. The aim of the present study was to evaluate whether untre...

Traumatic rupture of an intracranial dermoid cyst

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Raksha Ramlakhan, BMedSc, MBBCh

2015-01-01

Full Text Available Intracranial dermoid cysts are congenital tumors of ectodermal origin. Rupture of these cysts can occur spontaneously, but rupture in association with trauma is reported infrequently. The diagnosis of rupture is made by the presence of lipid (cholesterol droplets in the subarachnoid spaces and ventricles. Nonenhanced CT of the head demonstrates multiple foci of low attenuation that correspond with hyperintense signal on T1-weighted MRI. We present a case of an adult patient with rupture of an intracranial dermoid cyst, precipitated by minor trauma.

Arthroscintigraphy in suspected rotator cuff rupture

International Nuclear Information System (INIS)

Gratz, S.; Behr, T.; Becker, W.; Koester, G.; Vosshenrich, R.; Grabbe, E.

1998-01-01

Aim: In order to evaluate the diagnostic efficiency of arthroscintigraphy in suspected rotator cuff ruptures this new imaging procedure was performed 20 times in 17 patients with clinical signs of a rotator cuff lesion. The scintigraphic results were compared with sonography (n=20), contrast arthrography (n=20) and arthroscopy (n=10) of the shoulder joint. Methods: After performing a standard bone scintigraphy with intravenous application of 300 MBq 99m-Tc-methylene diphosphonate (MDP) for landmarking of the shoulder region arthroscintigraphy was performed after an intraarticular injection of 99m-Tc microcolloid (ALBU-RES 400 μCi/5 ml). The application was performed either in direct combination with contrast arthrography (n=10) or ultrasound conducted mixed with a local anesthetic (n=10). Findings at arthroscopical surgery (n=10) were used as the gold standard. Results: In case of complete rotator cuff rupture (n=5), arthroscintigraphy and radiographic arthrography were identical in 5/5. In one patient with advanced degenerative alterations of the shoulder joint radiographic arthrography incorrectly showed a complete rupture which was not seen by arthroscintigraphy and endoscopy. In 3 patients with incomplete rupture, 2/3 results were consistant. A difference was seen in one patient with a rotator cuff, that has been already revised in the past and that suffered of capsulitis and calcification. Conclusion: Arthroscinitgraphy is a sensitive technique for detection of rotator cuff ruptures. Because of the lower viscosity of the active compound, small ruptures can be easily detected, offering additional value over radiographic arthrography and ultrasound, especially for evaluation of incomplete cuff ruptures. (orig.) [de

Creep-rupture behavior of candidate Stirling engine iron supperalloys in high-pressure hydrogen. Volume 2: Hydrogen creep-rupture behavior

Science.gov (United States)

Bhattacharyya, S.; Peterman, W.; Hales, C.

1984-01-01

The creep rupture behavior of nine iron base and one cobalt base candidate Stirling engine alloys is evaluated. Rupture life, minimum creep rate, and time to 1% strain data are analyzed. The 3500 h rupture life stress and stress to obtain 1% strain in 3500 h are also estimated.

Use of generalized regression models for the analysis of stress-rupture data

International Nuclear Information System (INIS)

Booker, M.K.

1978-01-01

The design of components for operation in an elevated-temperature environment often requires a detailed consideration of the creep and creep-rupture properties of the construction materials involved. Techniques for the analysis and extrapolation of creep data have been widely discussed. The paper presents a generalized regression approach to the analysis of such data. This approach has been applied to multiple heat data sets for types 304 and 316 austenitic stainless steel, ferritic 2 1 / 4 Cr-1 Mo steel, and the high-nickel austenitic alloy 800H. Analyses of data for single heats of several materials are also presented. All results appear good. The techniques presented represent a simple yet flexible and powerful means for the analysis and extrapolation of creep and creep-rupture data

Comparison between smaller ruptured intracranial aneurysm and larger un-ruptured intracranial aneurysm: gene expression profile analysis.

Science.gov (United States)

Li, Hao; Li, Haowen; Yue, Haiyan; Wang, Wen; Yu, Lanbing; ShuoWang; Cao, Yong; Zhao, Jizong

2017-07-01

As it grows in size, an intracranial aneurysm (IA) is prone to rupture. In this study, we compared two extreme groups of IAs, ruptured IAs (RIAs) smaller than 10 mm and un-ruptured IAs (UIAs) larger than 10 mm, to investigate the genes involved in the facilitation and prevention of IA rupture. The aneurismal walls of 6 smaller saccular RIAs (size smaller than 10 mm), 6 larger saccular UIAs (size larger than 10 mm) and 12 paired control arteries were obtained during surgery. The transcription profiles of these samples were studied by microarray analysis. RT-qPCR was used to confirm the expression of the genes of interest. In addition, functional group analysis of the differentially expressed genes was performed. Between smaller RIAs and larger UIAs, 101 genes and 179 genes were significantly over-expressed, respectively. In addition, functional group analysis demonstrated that the up-regulated genes in smaller RIAs mainly participated in the cellular response to metal ions and inorganic substances, while most of the up-regulated genes in larger UIAs were involved in inflammation and extracellular matrix (ECM) organization. Moreover, compared with control arteries, inflammation was up-regulated and muscle-related biological processes were down-regulated in both smaller RIAs and larger UIAs. The genes involved in the cellular response to metal ions and inorganic substances may facilitate the rupture of IAs. In addition, the healing process, involving inflammation and ECM organization, may protect IAs from rupture.

Ruptured gastroepiploic artery aneurysm: A case report

Directory of Open Access Journals (Sweden)

Ahmad S. Ashrafi

Full Text Available Introduction: Gastroepiploic artery aneurysms are extremely rare, with few reported cases in the literature. The risk of rupture however, is high and thus warrants attention. Presentation of case: Here we present a rare case of a women who presented to the emergency department in shock and was found to have a ruptured gastroepiploic artery aneurysm during surgical exploration. Suture ligation of the aneurysm was completed. Discussion: Although rare, gastroepiploic artery aneurysms have up to a 90% rate of rupture and therefore require intervention. A laparoscopic approach has been described however, in cases where rupture has occurred, urgent laparotomy and control of hemorrhage is needed. Conclusion: We describe a rare case of a ruptured gastroepiploic aneurysm that was successfully managed with urgent laparotomy and aneurysmal resection. Keywords: Gastroepiploic, Aneurysm, Hemorrhage, Case report

Two-Dimensional Physical and CFD Modelling of Large Gas Bubble Behaviour in Bath Smelting Furnaces

Directory of Open Access Journals (Sweden)

Yuhua Pan

2010-09-01

Full Text Available The behaviour of large gas bubbles in a liquid bath and the mechanisms of splash generation due to gas bubble rupture in high-intensity bath smelting furnaces were investigated by means of physical and mathematical (CFD modelling techniques. In the physical modelling work, a two-dimensional Perspex model of the pilot plant furnace at CSIRO Process Science and Engineering was established in the laboratory. An aqueous glycerol solution was used to simulate liquid slag. Air was injected via a submerged lance into the liquid bath and the bubble behaviour and the resultant splashing phenomena were observed and recorded with a high-speed video camera. In the mathematical modelling work, a two-dimensional CFD model was developed to simulate the free surface flows due to motion and deformation of large gas bubbles in the liquid bath and rupture of the bubbles at the bath free surface. It was concluded from these modelling investigations that the splashes generated in high-intensity bath smelting furnaces are mainly caused by the rupture of fast rising large gas bubbles. The acceleration of the bubbles into the preceding bubbles and the rupture of the coalescent bubbles at the bath surface contribute significantly to splash generation.

Comparing slow and fast rupture in laboratory experiments

Science.gov (United States)

Aben, F. M.; Brantut, N.; David, E.; Mitchell, T. M.

2017-12-01

During the brittle failure of rock, elastically stored energy is converted into a localized fracture plane and surrounding fracture damage, seismic radiation, and thermal energy. However, the partitioning of energy might vary with the rate of elastic energy release during failure. Here, we present the results of controlled (slow) and dynamic (fast) rupture experiments on dry Lanhélin granite and Westerly granite samples, performed under triaxial stress conditions at confining pressures of 50 and 100 MPa. During the tests, we measured sample shortening, axial load and local strains (with 2 pairs of strain gauges glued directly onto the sample). In addition, acoustic emissions (AEs) and changes in seismic velocities were monitored. The AE rate was used as an indicator to manually control the axial load on the sample to stabilize rupture in the quasi-static failure experiments. For the dynamic rupture experiments a constant strain rate of 10-5 s-1 was applied until sample failure. A third experiment, labeled semi-controlled rupture, involved controlled rupture up to a point where the rupture became unstable and the remaining elastic energy was released dynamically. All experiments were concluded after a macroscopic fracture had developed across the whole sample and frictional sliding commenced. Post-mortem samples were epoxied, cut and polished to reveal the macroscopic fracture and the surrounding damage zone. The samples failed with average rupture velocities varying from 5x10-6 m/s up to >> 0.1 m/s. The analyses of AE locations on the slow ruptures reveal that within Westerly granite samples - with a smaller grain size - fracture planes are disbanded in favor of other planes when a geometrical irregularity is encountered. For the coarser grained Lanhélin granite a single fracture plane is always formed, although irregularities are recognized as well. The semi-controlled experiments show that for both rock types the rupture can become unstable in response to these

Ruptured Spleen

Science.gov (United States)

... be caused by various underlying problems, such as mononucleosis and other infections, liver disease, and blood cancers. ... cause a ruptured spleen. For instance, people with mononucleosis — a viral infection that can cause an enlarged ...

Period-dependent source rupture behavior of the 2011 Tohoku earthquake estimated by multi period-band Bayesian waveform inversion

Science.gov (United States)

Kubo, H.; Asano, K.; Iwata, T.; Aoi, S.

2014-12-01

Previous studies for the period-dependent source characteristics of the 2011 Tohoku earthquake (e.g., Koper et al., 2011; Lay et al., 2012) were based on the short and long period source models using different method. Kubo et al. (2013) obtained source models of the 2011 Tohoku earthquake using multi period-bands waveform data by a common inversion method and discussed its period-dependent source characteristics. In this study, to achieve more in detail spatiotemporal source rupture behavior of this event, we introduce a new fault surface model having finer sub-fault size and estimate the source models in multi period-bands using a Bayesian inversion method combined with a multi-time-window method. Three components of velocity waveforms at 25 stations of K-NET, KiK-net, and F-net of NIED are used in this analysis. The target period band is 10-100 s. We divide this period band into three period bands (10-25 s, 25-50 s, and 50-100 s) and estimate a kinematic source model in each period band using a Bayesian inversion method with MCMC sampling (e.g., Fukuda & Johnson, 2008; Minson et al., 2013, 2014). The parameterization of spatiotemporal slip distribution follows the multi-time-window method (Hartzell & Heaton, 1983). The Green's functions are calculated by the 3D FDM (GMS; Aoi & Fujiwara, 1999) using a 3D velocity structure model (JIVSM; Koketsu et al., 2012). The assumed fault surface model is based on the Pacific plate boundary of JIVSM and is divided into 384 subfaults of about 16 * 16 km^2. The estimated source models in multi period-bands show the following source image: (1) First deep rupture off Miyagi at 0-60 s toward down-dip mostly radiating relatively short period (10-25 s) seismic waves. (2) Shallow rupture off Miyagi at 45-90 s toward up-dip with long duration radiating long period (50-100 s) seismic wave. (3) Second deep rupture off Miyagi at 60-105 s toward down-dip radiating longer period seismic waves then that of the first deep rupture. (4) Deep

Misdiagnosed Chest Pain: Spontaneous Esophageal Rupture

Science.gov (United States)

Inci, Sinan; Gundogdu, Fuat; Gungor, Hasan; Arslan, Sakir; Turkyilmaz, Atila; Eroglu, Atila

2013-01-01

Chest pain is one of themost common complaints expressed by patients presenting to the emergency department, and any initial evaluation should always consider life-threatening causes. Esophageal rupture is a serious condition with a highmortality rate. If diagnosed, successful therapy depends on the size of the rupture and the time elapsed between rupture and diagnosis.We report on a 41-year-old woman who presented to the emergency department complaining of left-sided chest pain for two hours. PMID:27122690

Sensitivity analyses on in-vessel hydrogen generation for KNGR

International Nuclear Information System (INIS)

Kim, See Darl; Park, S.Y.; Park, S.H.; Park, J.H.

2001-03-01

Sensitivity analyses for the in-vessel hydrogen generation, using the MELCOR program, are described in this report for the Korean Next Generation Reactor. The typical accident sequences of a station blackout and a large LOCA scenario are selected. A lower head failure model, a Zircaloy oxidation reaction model and a B 4 C reaction model are considered for the sensitivity parameters. As for the base case, 1273.15K for a failure temperature of the penetrations or the lower head, an Urbanic-Heidrich correlation for the Zircaloy oxidation reaction model and the B 4 C reaction model are used. Case 1 used 1650K as the failure temperature for the penetrations and Case 2 considered creep rupture instead of penetration failure. Case 3 used a MATPRO-EG and G correlation for the Zircaloy oxidation reaction model and Case 4 turned off the B 4 C reaction model. The results of the studies are summarized below : (1) When the penetration failure temperature is higher, or the creep rupture failure model is considered, the amount of hydrogen increases for two sequences. (2) When the MATPRO-EG and G correlation for a Zircaloy oxidation reaction is considered, the amount of hydrogen is less than the Urbanic-Heidrich correlation (Base case) for both scenarios. (3) When the B 4 C reaction model turns off, the amount of hydrogen decreases for two sequences

Acute Iliac Artery Rupture: Endovascular Treatment

International Nuclear Information System (INIS)

Chatziioannou, A.; Mourikis, D.; Katsimilis, J.; Skiadas, V.; Koutoulidis, V.; Katsenis, K.; Vlahos, L.

2007-01-01

The authors present 7 patients who suffered iliac artery rupture over a 2 year period. In 5 patients, the rupture was iatrogenic: 4 cases were secondary to balloon angioplasty for iliac artery stenosis and 1 occurred during coronary angioplasty. In the last 2 patients, the rupture was secondary to iliac artery mycotic aneurysm. Direct placement of a stent-graft was performed in all cases, which was dilated until extravasation was controlled. Placement of the stent-graft was successful in all the cases, without any complications. The techniques used, results, and mid-term follow-up are presented. In conclusion, endovascular placement of a stent-graft is a quick, minimally invasive, efficient, and safe method for emergency treatment of acute iliac artery rupture, with satisfactory short- and mid-term results

CT diagnosis of ruptured abdominal aortic aneurysm

International Nuclear Information System (INIS)

Sacknoff, R.; Novelline, R.A.; Wittenberg, J.; Waltman, A.C.; De Luca, S.A.; Rhea, J.T.; Lawrason, J.N.

1986-01-01

Ruptured abdominal aortic aneurysm (AAA) is a life-threatening condition requiring immediate diagnosis and surgery. In a series of 23 consecutive patients scanned by CT for suspected ruptured AAA, CT proved 100% accurate. In seven patients with surgically or pathologically proved ruptured AAA, CT demonstrated a similar distribution of hemorrhage into the perirenal space and to a lesser degree into the anterior and posterior pararenal spaces. The 16 true-negative examinations included ten in patients with unruptured AAA and six in patients with other diseases. The authors conclude that patients in stable condition with suspected ruptured AAA should be examined by CT

Spontaneous rupture of adrenal metastasis from hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Lim, Chae Hun; Kim, Hyun Jin; Park, Soo Youn; Hwang, Seong Su; Choi, Hyun Joo [St. Vincent Hospital, Suwon (Korea, Republic of)

2007-03-15

Rupture of adrenal tumor from various primary origins is a rather rare event. We report here on a ruptured adrenal metastasis from hepatocellular carcinoma, and this ruptured metastasis was observed at the time of the initial diagnosis.

Hepatic Rupture Induced by Spontaneous Intrahepatic Hematoma

Directory of Open Access Journals (Sweden)

Jin-bao Zhou

2018-01-01

Full Text Available The etiology of hepatic rupture is usually secondary to trauma, and hepatic rupture induced by spontaneous intrahepatic hematoma is clinically rare. We describe here a 61-year-old female patient who was transferred to our hospital with hepatic rupture induced by spontaneous intrahepatic hematoma. The patient had no history of trauma and had a history of systemic lupus erythematosus for five years, taking a daily dose of 5 mg prednisone for treatment. The patients experienced durative blunt acute right upper abdominal pain one day after satiation, which aggravated in two hours, accompanied by dizziness and sweating. Preoperative diagnosis was rupture of the liver mass. Laparotomy revealed 2500 mL fluid consisting of a mixture of blood and clot in the peritoneal cavity. A 3.5 cm × 2.5 cm rupture was discovered on the hepatic caudate lobe near the vena cava with active arterial bleeding, and a 5  × 6 cm hematoma was reached on the right posterior lobe of the liver. Abdominal computed tomography (CT and laparotomy revealed spontaneous rupture of intrahepatic hematoma with hemorrhagic shock. The patient was successfully managed by suturing the rupture of the hepatic caudate lobe and clearing part of the hematoma. The postoperative course was uneventful, and the patient was discharged after two weeks of hospitalization.

Physical therapy in the conservative treatment for anterior cruciate ligament rupture followed by contralateral rupture: case report

OpenAIRE

Almeida, Gabriel Peixoto Leão; Arruda, Gilvan de Oliveira; Marques, Amélia Pasqual

2014-01-01

Although the surgical reconstruction be the obvious indication for the anterior cruciate ligament (ACL) lesion, there is no consensus on whether the results of surgery are superior to those obtained with nonsurgical management. The objective of this report was to describe a case of nonsurgical treatment for ACL rupture followed by a contralateral rupture. A 28-year-old female practitioner of muay-thai and handball suffered a non-contact ACL rupture in the left knee, and three months after the...

Experimental evaluation of emergency operating procedures on multiple steam generator tube rupture in INER integral system test facility

International Nuclear Information System (INIS)

Liu, T.J.; Lin, Y.M.; Lee, C.H.; Chang, C.Y.; Hong, W.T.

1997-01-01

The multiple steam generator tube rupture (SGTR) scenario in Westinghouse type pressurized water reactor (PWR) has been investigated at the Institute of Nuclear Energy Research (INER) Integral System Test (IIST) facility. This reduced-height and reduced-pressure test facility was designed to simulate the main features of Maanshan nuclear power plant. The SGTR test scenario assumes the double-ended break of one-, two- and six- tubes without other failures. The major operator actions follow the related symptom-oriented Emergency Operating Procedure (EOP) on the reference plant. This study focuses on the investigation of thermal-hydraulics phenomena and the adequacy of associated EOP to limit primary-to-secondary leakage. Through this study, it is found that the adequacy of current EOP in minimizing the radioactivity release demands early substantial operator involvement, especially in the multi-tubes break events. Also, the detailed mechanism of the main thermal-hydraulic phenomena during the SGTR transient are explored. (author)

Use of ICD-10 codes to monitor uterine rupture

DEFF Research Database (Denmark)

Thisted, Dorthe L A; Mortensen, Laust Hvas; Hvidman, Lone

2014-01-01

OBJECTIVES: Uterine rupture is a rare but severe complication in pregnancies after a previous cesarean section. In Denmark, the monitoring of uterine rupture is based on reporting of relevant diagnostic codes to the Danish Medical Birth Registry (MBR). The aim of our study was to examine the vali......OBJECTIVES: Uterine rupture is a rare but severe complication in pregnancies after a previous cesarean section. In Denmark, the monitoring of uterine rupture is based on reporting of relevant diagnostic codes to the Danish Medical Birth Registry (MBR). The aim of our study was to examine...... uterine ruptures, the sensitivity and specificity of the codes for uterine rupture were 83.8% and 99.1%, respectively. CONCLUSION: During the study period the monitoring of uterine rupture in the MBR was inadequate....

Evaluating the Possibility of a joint San Andreas-Imperial Fault Rupture in the Salton Trough Region

Science.gov (United States)

Kyriakopoulos, C.; Oglesby, D. D.; Meltzner, A. J.; Rockwell, T. K.

2016-12-01

A geodynamic investigation of possible earthquakes in a given region requires both field data and numerical simulations. In particular, the investigation of past earthquakes is also a fundamental part of understanding the earthquake potential of the Salton Trough region. Geological records from paleoseismic trenches inform us of past ruptures (length, magnitude, timing), while dynamic rupture models allow us to evaluate numerically the mechanics of such earthquakes. The two most recent events (Mw 6.4 1940 and Mw 6.9 1979) on the Imperial fault (IF) both ruptured up to the northern end of the mapped fault, giving the impression that rupture doesn't propagate further north. This result is supported by small displacements, 20 cm, measured at the Dogwood site near the end of the mapped rupture in each event. However, 3D paleoseismic data from the same site corresponding to the most recent pre-1940 event (1710 CE) and 5th (1635 CE) and 6th events back revealed up to 1.5 m of slip in those events. Since we expect the surface displacement to decrease toward the termination of a rupture, we postulate that in these earlier cases the rupture propagated further north than in 1940 or 1979. Furthermore, paleoseismic data from the Coachella site (Philibosian et al., 2011) on the San Andreas fault (SAF) indicates slip events ca. 1710 CE and 1588-1662 CE. In other words, the timing of two large paleoseismic displacements on the IF cannot be distinguished from the timing of the two most recent events on the southern SAF, leaving a question: is it possible to have through-going rupture in the Salton Trough? We investigate this question through 3D dynamic finite element rupture modeling. In our work, we considered two scenarios: rupture initiated on the IF propagating northward, and rupture initiated on the SAF propagating southward. Initial results show that, in the first case, rupture propagates north of the mapped northern terminus of the IF only under certain pre

Traumatic Fundal Rupture of unscarred Uterus in a Primigravida ...

African Journals Online (AJOL)

Background: Uterine rupture is an infrequent but life threatening obstetric emergency. Rupture of previously scarred uterus is often encountered especially in multiparous women, but the traumatic rupture of an unscarred primigravid uterus as presented here is a relatively rare event. We report a case of rupture of an ...

Bacteria Localization and Chorion Thinning among Preterm Premature Rupture of Membranes

Science.gov (United States)

Fortner, Kimberly B.; Grotegut, Chad A.; Ransom, Carla E.; Bentley, Rex C.; Feng, Liping; Lan, Lan; Heine, R. Phillips; Seed, Patrick C.; Murtha, Amy P.

2014-01-01

Objective Bacterial colonization of the fetal membranes and its role in pathogenesis of membrane rupture is poorly understood. Prior retrospective work revealed chorion layer thinning in preterm premature rupture of membranes (PPROM) subjects. Our objective was to prospectively examine fetal membrane chorion thinning and to correlate to bacterial presence in PPROM, preterm, and term subjects. Study Design Paired membrane samples (membrane rupture and membrane distant) were prospectively collected from: PPROM = 14, preterm labor (PTL = 8), preterm no labor (PTNL = 8), term labor (TL = 10), and term no labor (TNL = 8), subjects. Sections were probed with cytokeratin to identify fetal trophoblast layer of the chorion using immunohistochemistry. Fluorescence in situ hybridization was performed using broad range 16 s ribosomal RNA probe. Images were evaluated, chorion and choriodecidua were measured, and bacterial fluorescence scored. Chorion thinning and bacterial presence were compared among and between groups using Student's t-test, linear mixed effect model, and Poisson regression model (SAS Cary, NC). Results In all groups, the fetal chorion cellular layer was thinner at rupture compared to distant site (147.2 vs. 253.7 µm, prupture site compared to distant sites. In PPROM fetal chorion, we demonstrated pronounced global thinning. Although cause or consequence is uncertain, bacterial presence is greatest and inversely correlated with chorion thinning among PPROM subjects. PMID:24421883

Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness

Directory of Open Access Journals (Sweden)

S. Voß

2016-01-01

Full Text Available Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches—when averaged over the complete aneurysm sac—are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

Parameterization experiments performed via synthetic mass movements prototypes generated by 3D slope stability simulator

Science.gov (United States)

Colangelo, Antonio C.

2010-05-01

The central purpose of this work is to perform a reverse procedure in the mass movement conventional parameterization approach. The idea is to generate a number of synthetic mass movements by means of the "slope stability simulator" (Colangelo, 2007), and compeer their morphological and physical properties with "real" conditions of effective mass movements. This device is an integrated part of "relief unity emulator" (rue), that permits generate synthetic mass movements in a synthetic slope environment. The "rue" was build upon fundamental geomorphological concepts. These devices operate with an integrated set of mechanical, geomorphic and hydrological models. The "slope stability simulator" device (sss) permits to perform a detailed slope stability analysis in a theoretical three dimensional space, by means of evaluation the spatial behavior of critical depths, gradients and saturation levels in the "potential rupture surfaces" inferred along a set of slope profiles, that compounds a synthetic slope unity. It's a meta-stable 4-dimensional object generated by means of "rue", that represents a sequence evolution of a generator profile applied here, was adapted the infinite slope model for slope. Any slope profiles were sliced by means of finite element solution like in Bishop method. For the synthetic slope systems generated, we assume that the potential rupture surface occurs at soil-regolith or soil-rock boundary in slope material. Sixteen variables were included in the "rue-sss" device that operates in an integrated manner. For each cell, the factor of safety was calculated considering the value of shear strength (cohesion and friction) of material, soil-regolith boundary depth, soil moisture level content, potential rupture surface gradient, slope surface gradient, top of subsurface flow gradient, apparent soil bulk density and vegetation surcharge. The slope soil was considered as cohesive material. The 16 variables incorporated in the models were analyzed for

NORA-2, a model for creep deformation and rupture of zircaloy at high temperatures

International Nuclear Information System (INIS)

Raff, S.; Meyder, R.

1983-01-01

A model has been developed to describe Zircaloy cladding behaviour under LOCA and small leak conditions within specified temperature range and strain rates. The deformation model consists of a strain rate equation with two components representing strain rate controlled contributions from different deformation mechanisms. Transition from one mechanism to the other produces the strain rate dependence of the stress exponent of steady state creep. During transient creep the change of creep mechanisms produces a flow softening behaviour which induces unstable creep. Together with a strain hardening model, the strain history can be described for low and high strain values. The influence of oxidation is taken into account by modelling hardening due to solid solution of oxygen, cracking of the brittle oxide and oxygen stabilised α-phase layers, and by an oxidation-induced creep component in steam atmosphere. The rupture criterion is based on a strain fraction rule whose variables are temperature, strain rate or applied stress, and oxygen content. (author)

Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

Science.gov (United States)

Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E; Walker, Eric A

2015-08-01

Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition.

Acute Pectoralis Major Rupture Captured on Video

Directory of Open Access Journals (Sweden)

Alejandro Ordas Bayon

2016-01-01

Full Text Available Pectoralis major (PM ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture.

The UCERF3 grand inversion: Solving for the long‐term rate of ruptures in a fault system

Science.gov (United States)

Page, Morgan T.; Field, Edward H.; Milner, Kevin; Powers, Peter M.

2014-01-01

We present implementation details, testing, and results from a new inversion‐based methodology, known colloquially as the “grand inversion,” developed for the Uniform California Earthquake Rupture Forecast (UCERF3). We employ a parallel simulated annealing algorithm to solve for the long‐term rate of all ruptures that extend through the seismogenic thickness on major mapped faults in California while simultaneously satisfying available slip‐rate, paleoseismic event‐rate, and magnitude‐distribution constraints. The inversion methodology enables the relaxation of fault segmentation and allows for the incorporation of multifault ruptures, which are needed to remove magnitude‐distribution misfits that were present in the previous model, UCERF2. The grand inversion is more objective than past methodologies, as it eliminates the need to prescriptively assign rupture rates. It also provides a means to easily update the model as new data become available. In addition to UCERF3 model results, we present verification of the grand inversion, including sensitivity tests, tuning of equation set weights, convergence metrics, and a synthetic test. These tests demonstrate that while individual rupture rates are poorly resolved by the data, integrated quantities such as magnitude–frequency distributions and, most importantly, hazard metrics, are much more robust.

ACL Rupture in Collegiate Wrestler

Directory of Open Access Journals (Sweden)

Lindsay A. Palmer

2016-05-01

Full Text Available Objective: To educate others on unique Anterior Cruciate Ligament tears and percentage of usage of the ACL in normal daily function. Background: Patient is an eighteen year old male participating in wrestling and football at the time of the injury. Patient now only participates in wrestling. No previous knee or chronic injuries were reported prior to this injury. Patient was playing football during the time of injury. The patient stated that he planted his foot down and was tackled at the same time when the injury occurred. The patient felt his knee twist and buckle. Patient complained of clicking inside the knee and had minimal swelling. He also complained of it being difficult to bear weight at the time. The patient did not seek further treatment until two months after the injury occurred when he received an MRI. His MRI showed a positive finding for an Anterior Cruciate Ligament rupture. His previous Athletic Trainer could not find a positive diagnosis for the patient prior to the MRI. Differential Diagnosis: Possible meniscal or ACL injury. Treatment: Doctors officially diagnosed the injury as a complete rupture of the ACL. The patient did not receive surgery immediately. Doctors have stated that he only uses about 50% of his ACL on a daily basis compared to a normal person who uses about 95% of their ACL daily. Because of this, the patient played on his rupture for seven months before receiving surgery. He played a whole season of high school football and a whole season of wrestling his senior year with the ACL ruptured. The patient only used a brace for better comfort during the seven months. The patient then received reconstructive surgery to repair the rupture. A hamstring tendon graft was used to repair the ruptured ACL. Because a tendon was taken from the hamstring, patient experienced a tight ACL and hamstring of the left leg post-surgery. The patient participated in Physical Therapy for five months to strengthen and stretch the new

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

Science.gov (United States)

Seybold, C. A.; Harms, D. S.; Grossman, R. B.

2009-01-01

Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

Detailed Mapping of Historical and Preinstrumental Earthquake Ruptures in Central Asia Using Multi-Scale, Multi-Platform Photogrammetry

Science.gov (United States)

Elliott, A. J.; Walker, R. T.; Parsons, B.; Ren, Z.; Ainscoe, E. A.; Abdrakhmatov, K.; Mackenzie, D.; Arrowsmith, R.; Gruetzner, C.

2016-12-01

In regions of the planet with long historical records, known past seismic events can be attributed to specific fault sources through the identification and measurement of single-event scarps in high-resolution imagery and topography. The level of detail captured by modern remote sensing is now sufficient to map and measure complete earthquake ruptures that were originally only sparsely mapped or overlooked entirely. We can thus extend the record of mapped earthquake surface ruptures into the preinstrumental period and capture the wealth of information preserved in the numerous historical earthquake ruptures throughout regions like Central Asia. We investigate two major late 19th and early 20th century earthquakes that are well located macroseismically but whose fault sources had proved enigmatic in the absence of detailed imagery and topography. We use high-resolution topographic models derived from photogrammetry of satellite, low-altitude, and ground-based optical imagery to map and measure the coseismic scarps of the 1889 M8.3 Chilik, Kazakhstan and 1932 M7.6 Changma, China earthquakes. Measurement of the scarps on the combined imagery and topography reveals the extent and slip distribution of coseismic rupture in each of these events, showing both earthquakes involved multiple faults with variable kinematics. We use a 1-m elevation model of the Changma fault derived from Pleiades satellite imagery to map the changing kinematics of the 1932 rupture along strike. For the 1889 Chilik earthquake we use 1.5-m SPOT-6 satellite imagery to produce a regional elevation model of the fault ruptures, from which we identify three distinct, intersecting fault systems that each have >20 km of fresh, single-event scarps. Along sections of each of these faults we construct high resolution (330 points per sq m) elevation models using quadcopter- and helikite-mounted cameras. From the detailed topography we measure single-event oblique offsets of 6-10 m, consistent with the large

A case for historic joint rupture of the San Andreas and San Jacinto faults.

Science.gov (United States)

Lozos, Julian C

2016-03-01

The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior.

A case for historic joint rupture of the San Andreas and San Jacinto faults

Science.gov (United States)

Lozos, Julian C.

2016-01-01

The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior. PMID:27034977

Rupture model of the 2015 M7.2 Sarez, Central Pamir, earthquake and the importance of strike-slip faulting in the Pamir interior

Science.gov (United States)

Metzger, S.; Schurr, B.; Schoene, T.; Zhang, Y.; Sudhaus, H.

2016-12-01

The Pamir mountain range, located in the Northwest of the India-Asia collision zone, accommodates approximately one third of the northward advance of the Indian continent at this longitude (i.e. 34 mm/yr) mostly by shortening at its northern thrust system. Geodetic and seismic data sets reveal here a narrow zone of high deformation and M7+ earthquakes of mostly thrust type with some dextral strike-slip faulting observed, too. The Pamir interior shows sinistral strike-slip and normal faulting indicating north-south compression and east-west extension. In this tectonic setting the two largest instrumentally recorded earthquakes, the M7+ 1911 and 2015 earthquake events in the central Pamir occurred with left-lateral shear along a NE-SW rupture plane. We present the co-seismic deformation field of the 2015 earthquake observed by Radar satellite interferometry (InSAR), SAR amplitude offsets and high-rate Global Positioning System (GPS). The InSAR and offset results reveal that the earthquake created a 50 km long surface rupture with maximum left-lateral offsets of more than two meters on a yet unmapped fault trace of the Sarez Karakul Fault System (SKFS). We further derive a distributed slip-model including a thorough model parameter uncertainty study. Using a two-step approach to first find the optimal rupture geometry and then invert for slip on discrete patches, we show that a data-driven patch resolution produces yields a better representation of the near-surface slip and an increased slip precision than a uniform patch approach without increasing the number of parameters and thus calculation time. Our best-fit model yields a sub-vertical fault plane with a strike of N39.5 degrees and a rupture area of 80 x 40 km2 with a maximum slip of 2 meters in the upper 10 km of the crust near the surface rupture. The 1911 and 2015 earthquakes demonstrate the importance of sinistral strike-slip faulting on the SKFS, contributing both to shear between the western and eastern

Rupture tests with reactor pressure vessel head models

International Nuclear Information System (INIS)

Talja, H.; Keinaenen, H.; Hosio, E.; Pankakoski, P.H.; Rahka, K.

2003-01-01

In the LISSAC project (LImit Strains in Severe ACcidents), partly funded by the EC Nuclear Fission and Safety Programme within the 5th Framework programme, an extensive experimental and computational research programme is conducted to study the stress state and size dependence of ultimate failure strains. The results are aimed especially to make the assessment of severe accident cases more realistic. For the experiments in the LISSAC project a block of material of the German Biblis C reactor pressure vessel was available. As part of the project, eight reactor pressure vessel head models from this material (22 NiMoCr 3 7) were tested up to rupture at VTT. The specimens were provided by Forschungszentrum Karlsruhe (FzK). These tests were performed under quasistatic pressure load at room temperature. Two specimens sizes were tested and in half of the tests the specimens contain holes describing the control rod penetrations of an actual reactor pressure vessel head. These specimens were equipped with an aluminium liner. All six tests with the smaller specimen size were conducted successfully. In the test with the large specimen with holes, the behaviour of the aluminium liner material proved to differ from those of the smaller ones. As a consequence the experiment ended at the failure of the liner. The specimen without holes yielded results that were in very good agreement with those from the small specimens. (author)

Linguine sign in musculoskeletal imaging: calf silicone implant rupture

International Nuclear Information System (INIS)

Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E.; Walker, Eric A.

2015-01-01

Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition. (orig.)

Linguine sign in musculoskeletal imaging: calf silicone implant rupture

Energy Technology Data Exchange (ETDEWEB)

Duryea, Dennis; Petscavage-Thomas, Jonelle [Milton S. Hershey Medical Center, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Frauenhoffer, Elizabeth E. [Milton S. Hershey Medical Center, Department of Pathology, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Walker, Eric A. [Milton S. Hershey Medical Center, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA (United States); Uniformed Services University of the Health Sciences, Department of Radiology and Nuclear Medicine, Bethesda, MD, 20814 (United States)

2015-08-15

Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition. (orig.)

How material contrast around subduction faults may control coseismic slip and rupture dynamics: tsunami applications for the case study of Tohoku

Science.gov (United States)

Scala, Antonio; Murphy, Shane; Romano, Fabrizio; Lorito, Stefano; Festa, Gaetano; Volpe, Manuela; Piatanesi, Alessio

2017-04-01

Recent megathrust tsunamigenic events, e.g. Maule 2010 (M8.8) and Tohoku 2011 (M9.0), generated huge tsunami waves as a consequence of high slip in the shallow part of the respective subduction zone. Other events, (e.g. the recent Mentawai 2010, M7.8, or the historical Meiji 1896, M8.2), referred to as tsunami earthquakes, produced unexpectedly large tsunami waves, probably due to large slip at shallow depth over longer rupture durations compared to deeper thrust events. Subduction zone earthquakes originate and propagate along bimaterial interfaces separating materials having different elastic properties, e.g. continental and oceanic crust, a stiffer deep mantle wedge, shallow compliant accretionary prism etc. Bimaterial interfaces have been showed, through observations (seismological and laboratory) and theoretical studies, to affect the rupture: introducing a preferred rupture direction as well as asymmetric rupture velocities and shear stress redistributions. Such features are predominantly due to the break of symmetry between the two sides of the interface in turn ascribable to the complex coupling between the frictional interfacial sliding and the slip-induced normal stress perturbations. In order to examine the influence of material contrast on a fault plane on the seismic source and tsunami waves, we modelled a Tohoku-like subduction zone to perform a large number of 2D along-dip rupture dynamics simulations in the framework of linear slip weakening both for homogeneous and bimaterial fault. In this latter model, the rupture acts as the interface between the subducting oceanic crust and the overriding layers (accretionary prism, continental crust and mantle wedge), varying the position of the shear stress asperity acting as nucleation patch. Initial results reveal that ruptures in homogeneous media produce earthquakes with large slip at depth compared to the case where bi-material interface is included. However the opposite occurs for events nucleating at

Uterine rupture without previous caesarean delivery

DEFF Research Database (Denmark)

Thisted, Dorthe L. A.; H. Mortensen, Laust; Krebs, Lone

2015-01-01

to uterine rupture when adjusted for parity, epidural analgesia and augmentation by oxytocin. CONCLUSION: Although uterine rupture is rare, its association with epidural analgesia and augmentation of labour with oxytocin in multipara should be considered. Thus, vigilance should be exercised when labour...

Coiling of ruptured pericallosal artery aneurysms.

NARCIS (Netherlands)

Menovsky, T.; Rooij, W.J.J. van; Sluzewski, M.; Wijnalda, D.

2002-01-01

OBJECTIVE: To assess the technical feasibility of treating ruptured pericallosal artery aneurysms with detachable coils and to evaluate the anatomic and clinical results. METHODS: Over a period of 27 months, 12 patients with a ruptured pericallosal artery aneurysm were treated with detachable

[Effects of posterior tibial slope on non-contact anterior cruciate ligament rupture and stability of anterior cruciate ligament rupture knee].

Science.gov (United States)

Yue, De-bo; E, Sen; Wang, Bai-liang; Wang, Wei-guo; Guo, Wan-shou; Zhang, Qi-dong

2013-05-07

To retrospectively explore the correlation between anterior cruciate ligament (ACL)-ruptured knees, stability of ACL-rupture knee and posterior tibial slope (PTS). From January 2008 to October 2012, 150 knees with ACL rupture underwent arthroscopic surgery for ACL reconstruction. A control group was established for subjects undergoing arthroscopic surgery without ACL rupture during the same period. PTS was measured on a digitalized lateral radiograph. Lachman and mechanized pivot shift tests were performed for assessing the stability of knee. There was significant difference (P = 0.007) in PTS angle between the patients with ACL rupture (9.5 ± 2.2 degrees) and the control group (6.6 ± 1.8 degrees). Only among females, increased slope of tibial plateau had effect on the Lachman test. There was a higher positive rate of pivot shift test in patients of increased posterior slope in the ACL rupture group. Increased posterior tibial slope (>6.6) appears to contribute to non-contact ACL injuries in females. And the changes of tibial slope have no effect upon the Lachman test. However, large changes in tibial slope affect pivot shift.

Spontaneous Splenic Rupture in Melanoma

Directory of Open Access Journals (Sweden)

Hadi Mirfazaelian

2014-01-01

Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

Experimental evidence that thrust earthquake ruptures might open faults.

Science.gov (United States)

Gabuchian, Vahe; Rosakis, Ares J; Bhat, Harsha S; Madariaga, Raúl; Kanamori, Hiroo

2017-05-18

Many of Earth's great earthquakes occur on thrust faults. These earthquakes predominantly occur within subduction zones, such as the 2011 moment magnitude 9.0 eathquake in Tohoku-Oki, Japan, or along large collision zones, such as the 1999 moment magnitude 7.7 earthquake in Chi-Chi, Taiwan. Notably, these two earthquakes had a maximum slip that was very close to the surface. This contributed to the destructive tsunami that occurred during the Tohoku-Oki event and to the large amount of structural damage caused by the Chi-Chi event. The mechanism that results in such large slip near the surface is poorly understood as shallow parts of thrust faults are considered to be frictionally stable. Here we use earthquake rupture experiments to reveal the existence of a torquing mechanism of thrust fault ruptures near the free surface that causes them to unclamp and slip large distances. Complementary numerical modelling of the experiments confirms that the hanging-wall wedge undergoes pronounced rotation in one direction as the earthquake rupture approaches the free surface, and this torque is released as soon as the rupture breaks the free surface, resulting in the unclamping and violent 'flapping' of the hanging-wall wedge. Our results imply that the shallow extent of the seismogenic zone of a subducting interface is not fixed and can extend up to the trench during great earthquakes through a torquing mechanism.

Endovascular therapeutic strategies in ruptured intracranial aneurysms

International Nuclear Information System (INIS)

Machi, Paolo; Lobotesis, Kyriakos; Vendrell, Jean Francoise; Riquelme, Carlos; Eker, Omer; Costalat, Vincent; Bonafe, Alain

2013-01-01

The aim of the present study was to evaluate endovascular techniques used currently which were not available at the time of ISAT inclusion period, such as balloon remodelling and flow-divertion, in order to assess whether these new technologies have improved the endovascular approach outcomes. We present a review of articles, published in major journals, with the aim to evaluate the efficacy and the safety of coiling with balloon remodelling for the treatment of ruptured aneurysms in comparison to coiling performed without such coadjutant techniques. Furthermore, we reviewed publications reporting on the treatment of ruptured aneurysms in the acute phase with the one of the most recent technologies available nowadays: the flow diverting stent. Looking at the recent literature the results regarding ruptured aneurysms treated with balloon assisted coiling (BAC) have shown an improvement in terms of anatomical results and morbi-mortality rates. Case series of ruptured middle cerebral artery (MCA) aneurysms treated by EVT report results similar to those obtained by surgical clipping. Several articles recently report encouraging results in treating ruptured dissecting and blister aneurysms with flow diverters. Questions regarding the best treatment available for ruptured aneurysms are yet to be answered. Hence there is a need for a subsequent trial aiming to answer these unresolved issues

RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

Directory of Open Access Journals (Sweden)

Maria URSACHI (BOLOTA

2016-12-01

Full Text Available The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amniotic sac (PRAS is defined as rupture of membranes before the onset of labor. Premature rupture of the fetal membrane, which occurs before 37 weeks of gestation, usually, refers to preterm premature rupture of membranes. Despite advances in the care period, premature rupture of membranes and premature rupture of membranes preterm continue to be regarded as serious obstetric complications. On the term 8% - 10% of pregnant women have premature rupture of membranes; these women are at increased risk of intrauterine infections, where the interval between membrane rupture and expulsion is rolled-over. Premature rupture of membranes preterm occurs in approximately 1% of all pregnancies and is associated with 30% -40% of preterm births. Thus, it is important to identify the cause of pre-term birth (after less than 37 completed weeks of "gestation" and its complications, including respiratory distress syndrome, neonatal infection and intraventricular hemorrhage. Objectives: the development of the protocol of the clinical trial on patients with impending preterm birth, study clinical and statistical on the socio-demographic characteristics of patients with imminent preterm birth; clinical condition of patients and selection of cases that could benefit from the application of interventional therapy; preclinical investigation (biological and imaging of patients with imminent preterm birth; the modality therapy; clinical investigation of the effectiveness of short

Fault Gauge Numerical Simulation : Dynamic Rupture Propagation and Local Energy Partitioning

Science.gov (United States)

Mollon, G.

2017-12-01

In this communication, we present dynamic simulations of the local (centimetric) behaviour of a fault filled with a granular gauge submitted to dynamic rupture. The numerical tool (Fig. 1) combines classical Discrete Element Modelling (albeit with the ability to deal with arbitrary grain shapes) for the simualtion of the gauge, and continuous modelling for the simulation of the acoustic waves emission and propagation. In a first part, the model is applied to the simulation of steady-state shearing of the fault under remote displacement boudary conditions, in order to observe the shear accomodation at the interface (R1 cracks, localization, wear, etc.). It also makes it possible to fit to desired values the Rate and State Friction properties of the granular gauge by adapting the contact laws between grains. Such simulations provide quantitative insight in the steady-state energy partitionning between fracture, friction and acoustic emissions as a function of the shear rate. In a second part, the model is submitted to dynamic rupture. For that purpose, the fault is elastically preloaded just below rupture, and a displacement pulse is applied at one end of the sample (and on only one side of the fault). This allows to observe the propagation of the instability along the fault and the interplay between this propagation and the local granular phenomena. Energy partitionning is then observed both in space and time.

National Rates of Uterine Rupture are not Associated with Rates of Previous Caesarean Delivery

DEFF Research Database (Denmark)

Colmorn, Lotte B.; Langhoff-Roos, Jens; Jakobsson, Maija

2017-01-01

% of all Nordic deliveries. Information on the comparison population was retrieved from the national medical birth registers. Incidence rate ratios by previous caesarean delivery and intended mode of delivery after caesarean were modelled using Poisson regression. RESULTS: The incidence of uterine rupture......BACKGROUND: Previous caesarean delivery and intended mode of delivery after caesarean are well-known individual risk factors for uterine rupture. We examined if different national rates of uterine rupture are associated with differences in national rates of previous caesarean delivery and intended...... was 7.8/10 000 in Finland and 4.6/10 000 in Denmark. Rates of caesarean (21.3%) and previous caesarean deliveries (11.5%) were highest in Denmark, while the rate of intended vaginal delivery after caesarean was highest in Finland (72%). National rates of uterine rupture were not associated...

Numerical simulation of faulting in the Sunda Trench shows that seamounts may generate megathrust earthquakes

Science.gov (United States)

Jiao, L.; Chan, C. H.; Tapponnier, P.

2017-12-01

The role of seamounts in generating earthquakes has been debated, with some studies suggesting that seamounts could be truncated to generate megathrust events, while other studies indicate that the maximum size of megathrust earthquakes could be reduced as subducting seamounts could lead to segmentation. The debate is highly relevant for the seamounts discovered along the Mentawai patch of the Sunda Trench, where previous studies have suggested that a megathrust earthquake will likely occur within decades. In order to model the dynamic behavior of the Mentawai patch, we simulated forearc faulting caused by seamount subducting using the Discrete Element Method. Our models show that rupture behavior in the subduction system is dominated by stiffness of the overriding plate. When stiffness is low, a seamount can be a barrier to rupture propagation, resulting in several smaller (M≤8.0) events. If, however, stiffness is high, a seamount can cause a megathrust earthquake (M8 class). In addition, we show that a splay fault in the subduction environment could only develop when a seamount is present, and a larger offset along a splay fault is expected when stiffness of the overriding plate is higher. Our dynamic models are not only consistent with previous findings from seismic profiles and earthquake activities, but the models also better constrain the rupture behavior of the Mentawai patch, thus contributing to subsequent seismic hazard assessment.

Computed tomography diagnosis of hepatocellular carcinoma rupture haemorrhage

International Nuclear Information System (INIS)

Zhi Weike; Jiang Bin; Liu Jinquan; Li Sixia; Zhu Zhichang

2004-01-01

Objective: To evaluate the diagnostic value of hepatocellular carcinoma rupture hemorrhage using Computed Tomography. Methods: Six cases diagnosed hepatocellular carcinoma rupture hemorrhage were analyzed by morphic and histologic method and investigated the key point of scan in diagnosis. Result: The correct rate of hepatocellular carcinoma rupture hemorrhage by Computed Tomography is above 83 percent, it characteristic representation is strip and would high-density shadow after enhancement. Conclusion: The characteristic representation of hepatocellular carcinoma rupture hemorrhage is attain by Computed Tomography, which provides effective operation evidences for clinical operation. (authors)

Fault Rupture Model of the 2016 Gyeongju, South Korea, Earthquake and Its Implication for the Underground Fault System

Science.gov (United States)

Uchide, Takahiko; Song, Seok Goo

2018-03-01

The 2016 Gyeongju earthquake (ML 5.8) was the largest instrumentally recorded inland event in South Korea. It occurred in the southeast of the Korean Peninsula and was preceded by a large ML 5.1 foreshock. The aftershock seismicity data indicate that these earthquakes occurred on two closely collocated parallel faults that are oblique to the surface trace of the Yangsan fault. We investigate the rupture properties of these earthquakes using finite-fault slip inversion analyses. The obtained models indicate that the ruptures propagated NNE-ward and SSW-ward for the main shock and the large foreshock, respectively. This indicates that these earthquakes occurred on right-step faults and were initiated around a fault jog. The stress drops were up to 62 and 43 MPa for the main shock and the largest foreshock, respectively. These high stress drops imply high strength excess, which may be overcome by the stress concentration around the fault jog.

Risk factors affecting chronic rupture of the plantar fascia.

Science.gov (United States)

Lee, Ho Seong; Choi, Young Rak; Kim, Sang Woo; Lee, Jin Yong; Seo, Jeong Ho; Jeong, Jae Jung

2014-03-01

Prior to 1994, plantar fascia ruptures were considered as an acute injury that occurred primarily in athletes. However, plantar fascia ruptures have recently been reported in the setting of preexisting plantar fasciitis. We analyzed risk factors causing plantar fascia rupture in the presence of preexisting plantar fasciitis. We retrospectively reviewed 286 patients with plantar fasciitis who were referred from private clinics between March 2004 and February 2008. Patients were divided into those with or without a plantar fascia rupture. There were 35 patients in the rupture group and 251 in the nonrupture group. The clinical characteristics and risk factors for plantar fascia rupture were compared between the 2 groups. We compared age, gender, the affected site, visual analog scale pain score, previous treatment regimen, body mass index, degree of ankle dorsiflexion, the use of steroid injections, the extent of activity, calcaneal pitch angle, the presence of a calcaneal spur, and heel alignment between the 2 groups. Of the assessed risk factors, only steroid injection was associated with the occurrence of a plantar fascia rupture. Among the 35 patients with a rupture, 33 had received steroid injections. The odds ratio of steroid injection was 33. Steroid injections for plantar fasciitis should be cautiously administered because of the higher risk for plantar fascia rupture. Level III, retrospective comparative study.

Cognitive frames in psychology: demarcations and ruptures.

Science.gov (United States)

Yurevich, Andrey V

2009-06-01

As there seems to be a recurrent feeling of crisis in psychology, its present state is analyzed in this article. The author believes that in addition to the traditional manifestations that have dogged psychology since it emerged as an independent science some new features of the crisis have emerged. Three fundamental "ruptures" are identified: the "horizontal" rupture between various schools and trends, the "vertical" rupture between natural science and humanitarian psychology, and the "diagonal" rupture between academic research and applied practice of psychology. These manifestations of the crisis of psychology have recently been compounded by the crisis of its rationalistic foundations. This situation is described in terms of the cognitive systems in psychology which include meta-theories, paradigms, sociodigms and metadigms.

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

Science.gov (United States)

Rolf, Christer G; Fu, Sai-Chuen; Hopkins, Chelsea; Luan, Ju; Ip, Margaret; Yung, Shu-Hang; Friman, Göran; Qin, Ling; Chan, Kai-Ming

2017-07-01

The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria. Bacteria are present in ruptured ATs but not in healthy tendons. Cross-sectional study; Level of evidence, 3. Patients with spontaneous AT ruptures and patients undergoing anterior cruciate ligament (ACL) reconstruction were recruited for this study. During AT surgical repair, excised tendinopathic tissue was collected, and healthy tendon samples were obtained as controls from hamstring tendon grafts used in ACL reconstruction. Half of every sample was reserved for DNA extraction and the other half for histology. Polymerase chain reaction (PCR) was conducted using 16S rRNA gene universal primers, and the PCR products were sequenced for the identification of bacterial species. A histological examination was performed to compare tendinopathic changes in the case and control samples. Five of 20 AT rupture samples were positive for the presence of bacterial DNA, while none of the 23 hamstring tendon samples were positive. Sterile operating and experimental conditions and tests on samples, controlling for harvesting and processing procedures, ruled out the chance of postoperative bacterial contamination. The species identified predominantly belonged to the Staphylococcus genus. AT rupture samples exhibited histopathological features characteristic of tendinopathy, and most healthy hamstring tendon samples displayed normal tendon features. There were no apparent differences in histopathology between the bacterial DNA-positive and bacterial DNA-negative AT rupture samples. The authors have demonstrated the presence of bacterial DNA in ruptured AT samples. It may suggest the potential involvement of bacteria

Challenging Friesian horse diseases : aortic rupture and megaesophagus

NARCIS (Netherlands)

Ploeg, M.

2015-01-01

Aortic rupture is quite rare in Warmblood horses and is best known as an acute and fatal rupture of the aortic root in older breeding stallions. It has now become clear that aortic rupture, which is diagnosed around an age of 4 years, is more frequent in the Friesian breed than in others. The high

Spontaneous rupture of the esophagus associated with intramural rupture caused by ingestion of weeding medicine (Lasso)

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Keon; Park, Heung Il; Kwun, Chung Sik [Chun Nam University College of Medicine, Kwangju (Korea, Republic of)

1975-06-15

This is a report of a case of spontaneous rupture of the esophagus associated with intramural rupture caused by ingestion of weeding medicine for the purpose of suicide in a 27 year old Korean male whose chief complaints were dyspnea, epigastric pain, swallowing disturbance, and hoarseness for 3 days prior to admission. A review of literature is submitted.

Ruptured rectal duplication with urogenital abnormality: Unusual presentation.

Science.gov (United States)

Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

2015-01-01

Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

Bilateral spontaneous rupture of flexor digitorum profundus tendons.

LENUS (Irish Health Repository)

O'Sullivan, S T

2012-02-03

Spontaneous tendon rupture is an unusual condition usually associated with underlying disease processes such as rheumatoid arthritis, chronic renal failure or bony abnormalities of the hand. We report a case of spontaneous, non-concurrent bilateral rupture of flexor profundus tendons in an otherwise healthy individual. Treatment was successful and consisted of a two-stage reconstruction of the ruptured tendon.

Analysis of multiple-tube ruptures in both steam generators for the Three Mile Island-1 pressurized water reactor

International Nuclear Information System (INIS)

Nassersharif, B.

1985-01-01

The operator guidelines were followed for both transients described. Both transients resulted in SG overfill and the tube-rupture flow did not terminate in either transient. The following statements can be deducted from the results of the calculations: the tube-rupture flow could not be stopped for either case during 2600 s (43 min) of transient time; each accident scenario resulted in SG overfill; both SGs overfilled by 1600 s (27 min) and 1800 s (30 min) for Cases 1 and 2, respectively; conditions for isolation of the SGs were not reached; and core subcooling was not lost in either case but the upper head was voided in Case 2. Comparison of the cooldown rates in the two cases after 1200 s (20 min) shows that these rates are equal (i.e., restart of the RCPs did not change the primary-system cooldown rate). However, in Case 2, a steam bubble was formed in the upper head, which did not disappear during the simulated time. One of the immediate actions in the guidelines was to fill both SGs to 95% level. This step was almost unnecessary because the tube-rupture flow was large enough that the 15.4 - mK/s (100 - 0 F h) cooldown-rate limit was exceeded and AFW could not be injected. Also, the guidelines did not address the SG overfill issue

Rupture of esophagus by compressed air.

Science.gov (United States)

Wu, Jie; Tan, Yuyong; Huo, Jirong

2016-11-01

Currently, beverages containing compressed air such as cola and champagne are widely used in our daily life. Improper ways to unscrew the bottle, usually by teeth, could lead to an injury, even a rupture of the esophagus. This letter to editor describes a case of esophageal rupture caused by compressed air.

The roentgenographic findings of achilles tendon rupture

Energy Technology Data Exchange (ETDEWEB)

Seouk, Kang Hyo; Keun, Rho Yong [Shilla General Hospital, Seoul (Korea, Republic of)

1999-03-01

To evaluate the diagnostic value of a lateral view of the ankles in Achilles tendon rupture. We performed a retrospective analysis of the roentgenographic findings of 15 patients with surgically proven Achilles tendon rupture. Four groups of 15 patients(normal, ankle sprain, medial lateral malleolar fracture, and calcaneal fracture) were analysed as reference groups. Plain radiographs were reviewed with regard to Kager's triangle, Arner's sign, Toygar's angle, ill defined radiolucent shadow through the Achilles tendon, sharpness of the anterior margin of Achilles tendon, and meniscoid smooth margin of the posterior skin surface of the ankle. Kager's triangle was deformed and disappeared after rupture of the Achilles tendon in nine patients(60%) with operative verification of the rupture, six patients(40%) had a positive Arner's sign, while none had a diminished Toygars angle. In 13 patients(87%) with a ruptured Achilles tendon, the thickness of this was nonuniform compared with the reference group. The anterior margin of the Achilles tendon became serrated and indistinct in 14 patients(93%) in whom this was ruptured. An abnormal ill defined radiolucent shadow through the Achilles tendon was noted in nine patient(60%), and nonparallelism between the anterior margin of the Achilles tendon and posterior skin surface of the ankle was detected in 11 patients(73%). The posterior skin surface of the ankle had a nodular surface margin in 13 patients(87%). A deformed Kager's triangle and Achilles tendon, and an abnormal ill defined radiolucent shadow through the Achilles tendon in a lateral view of the ankles are important findings for the diagnesis of in diagnosing achilles tendon rupture.

The roentgenographic findings of achilles tendon rupture

International Nuclear Information System (INIS)

Seouk, Kang Hyo; Keun, Rho Yong

1999-01-01

To evaluate the diagnostic value of a lateral view of the ankles in Achilles tendon rupture. We performed a retrospective analysis of the roentgenographic findings of 15 patients with surgically proven Achilles tendon rupture. Four groups of 15 patients(normal, ankle sprain, medial lateral malleolar fracture, and calcaneal fracture) were analysed as reference groups. Plain radiographs were reviewed with regard to Kager's triangle, Arner's sign, Toygar's angle, ill defined radiolucent shadow through the Achilles tendon, sharpness of the anterior margin of Achilles tendon, and meniscoid smooth margin of the posterior skin surface of the ankle. Kager's triangle was deformed and disappeared after rupture of the Achilles tendon in nine patients(60%) with operative verification of the rupture, six patients(40%) had a positive Arner's sign, while none had a diminished Toygars angle. In 13 patients(87%) with a ruptured Achilles tendon, the thickness of this was nonuniform compared with the reference group. The anterior margin of the Achilles tendon became serrated and indistinct in 14 patients(93%) in whom this was ruptured. An abnormal ill defined radiolucent shadow through the Achilles tendon was noted in nine patient(60%), and nonparallelism between the anterior margin of the Achilles tendon and posterior skin surface of the ankle was detected in 11 patients(73%). The posterior skin surface of the ankle had a nodular surface margin in 13 patients(87%). A deformed Kager's triangle and Achilles tendon, and an abnormal ill defined radiolucent shadow through the Achilles tendon in a lateral view of the ankles are important findings for the diagnesis of in diagnosing achilles tendon rupture

Release of UF6 from a ruptured model 48Y cylinder at Sequoyah Fuels Corporation Facility: lessons-learned report

International Nuclear Information System (INIS)

1986-08-01

The uranium hexafluoride (UF 6 ) release of January 4, 1986, at the Sequoyah Fuels Corporation facility has been reviewed by a NRC Lessons-Learned Group. A Model 48Y cylinder containing UF 6 ruptured upon being heated after it was grossly overfilled. The UF 6 released upon rupture of the cylinder reacted with airborne moisture to produce hydrofluoric acid (HF) and uranyl fluoride (UO 2 F 2 ). One individual died from exposure to airborne HF and several others were injured. There were no significant immediate effects from exposure to uranyl fluoride. This supplement report contains NRC's response to the recommendations made in NUREG-1198 by the Lessons Learned Group. In developing a response to each of the recommendations, the staff considered actions that should be taken: (1) for the restart of the Sequoyah Fuels Facility; (2) to make near-term improvement; and (3) to improve the regulatory framework

Cyclic creep-rupture behavior of three high-temperature alloys.

Science.gov (United States)

Halford, G. R.

1972-01-01

Study of some important characteristics of the cyclic creep-rupture curves for the titanium alloy 6Al-2Sn-4Zr-2Mo at 900 and 1100 F (755 and 865 K), the cobalt-base alloy L-605 at 1180 F (910 K), and for two hardness levels of 316 stainless steel at 1300 F (980 K). The cyclic creep-rupture curve relates tensile stress and tensile time-to-rupture for strain-limited cyclic loading and has been found to be independent of the total strain range and the level of compressive stress employed in the cyclic creep-rupture tests. The cyclic creep-rupture curve was always found to be above and to the right of the conventional (constant load) monotonic creep-rupture curve by factors ranging from 2 to 10 in time-to-rupture. This factor tends to be greatest when the creep ductility is large. Cyclic creep acceleration was observed in every cyclic creep-rupture test conducted. The phenomenon was most pronounced at the highest stress levels and when the tensile and compressive stresses were completely reversed. In general, creep rates were found to be lower in compression than in tension for equal true stresses. The differences, however, were strongly material-dependent.

Treatment strategy for ruptured abdominal aortic aneurysms.

Science.gov (United States)

Davidovic, L

2014-07-01

Rupture is the most serious and lethal complication of the abdominal aortic aneurysm. Despite all improvements during the past 50 years, ruptured abdominal aortic aneurysms are still associated with very high mortality. Namely, including patients who die before reaching the hospital, the mortality rate due to abdominal aortic aneurysm rupture is 90%. On the other hand, during the last twenty years, the number of abdominal aortic aneurysms significantly increased. One of the reasons is the fact that in majority of countries the general population is older nowadays. Due to this, the number of degenerative AAA is increasing. This is also the case for patients with abdominal aortic aneurysm rupture. Age must not be the reason of a treatment refusal. Optimal therapeutic option ought to be found. The following article is based on literature analysis including current guidelines but also on my Clinics significant experience. Furthermore, this article show cases options for vascular medicine in undeveloped countries that can not apply endovascular procedures at a sufficient level and to a sufficient extent. At this moment the following is evident. Thirty-day-mortality after repair of ruptured abdominal aortic aneurysms is significantly lower in high-volume hospitals. Due to different reasons all ruptured abdominal aortic aneurysms are not suitable for EVAR. Open repair of ruptured abdominal aortic aneurysm should be performed by experienced open vascular surgeons. This could also be said for the treatment of endovascular complications that require open surgical conversion. There is no ideal procedure for the treatment of AAA. Each has its own advantages and disadvantages, its own limits and complications, as well as indications and contraindications. Future reductions in mortality of ruptured abdominal aortic aneurysms will depend on implementation of population-based screening; on strategies to prevent postoperative organ injury and also on new medical technology

Rupture of the urinary bladder after minimal trauma

International Nuclear Information System (INIS)

Myrseth, L.E.; Johansen, T.E.B.

1991-01-01

Rupture of the urinary bladder is a rare injury most often encountered after severe trauma and in conjunction with injuries to other organ systems. It may occur, however, without concomitant injury and also after minimal trauma. This diagnosis must be suspected in a patient with abdominal pain who is unable to void or who presents hematuria. The diagnosis is made by means of a retrograde cystogram using 350-400 ml contrast medium and supplemented by a drainage film. Intrapertioneal ruptures should be treated surgically by closure in layers, and drainage. Patients with extraperitoneal ruptures can safely be treated with simple catheter drainage until the rupture has healed, usually within 10-20 days. The authors report three cases of bladder rupture after minimal trauma and describe the state of the art of diagnosis and treatment of these injuries. 15 refs., 3 figs

Computed tomography features and predictive findings of ruptured gastrointestinal stromal tumours

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Sil; Kim, Hyun Jin; Park, Seong Ho; Lee, Jong Seok; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Songpa-Gu, Seoul (Korea, Republic of)

2017-06-15

To evaluate the CT features of ruptured GISTs and factors that might be predictive of rupture through comparison with CTs taken prior to rupture and CTs of non-ruptured GIST. Forty-nine patients with ruptured GIST and forty-nine patients with non-ruptured GIST matched by age, gender and location were included. Clinical data including pharmacotherapy were reviewed. The imaging features were analyzed. Prior CT obtained before rupture were evaluated. The most common location of ruptured GIST was small bowel with mean size of 12.1 cm. Ruptured GIST commonly showed wall defects, >40 % eccentric necrosis, lobulated shaped, air density in mass, pneumoperitoneum, peritonitis, hemoperitoneum and ascites (p < 0.001-0.030). Twenty-seven of 30 patients with follow up imaging received targeted therapy. During follow-up, thickness of the tumour wall decreased. Increase in size and progression of necrosis were common during targeted therapy (p = 0.017). Newly developed ascites, peritonitis and hemoperitoneum was more common (p < 0.001-0.036). Ruptured GISTs commonly demonstrate large size, >40 % eccentric necrosis, wall defects and lobulated shape. The progression of necrosis with increase in size and decreased wall thickness during targeted therapy may increase the risk of rupture. Rupture should be considered when newly developed peritonitis, hemoperitoneum, or ascites are noted during the follow-up. (orig.)

The hemodynamics in intracranial aneurysm ruptured region with active contrast leakage during computed tomography angiography

Science.gov (United States)

Li, Ming-Lung; Wang, Yi-Chou; Liou, Tong-Miin; Lin, Chao-An

2014-10-01

Precise locations of rupture region under contrast agent leakage of five ruptured cerebral artery aneurysms during computed tomography angiography, which is to our knowledge for the first time, were successfully identified among 101 patients. These, together with numerical simulations based on the reconstructed aneurysmal models, were used to analyze hemodynamic parameters of aneurysms under different cardiac cyclic flow rates. For side wall type aneurysms, different inlet flow rates have mild influences on the shear stresses distributions. On the other hand, for branch type aneurysms, the predicted wall shear stress (WSS) correlates strongly with the increase of inlet vessel velocity. The mean and time averaged WSSes at rupture regions are found to be lower than those over the surface of the aneurysms. Also, the levels of the oscillatory shear index (OSI) are higher than the reported threshold value, supporting the assertion that high OSI correlates with rupture of the aneurysm. However, the present results also indicate that OSI level at the rupture region is relatively lower.

Extreme of random field over rectangle with application to concrete rupture stresses

DEFF Research Database (Denmark)

Ditlevsen, Ove Dalager

2000-01-01

to time consuming simulation procedures. This paperrevives a conceptually simple approach that gives surprisingly good results in particular for wide band typesof random processes and fields. The closed form formulas obtained for smooth Gaussian fieldsover rectangles contain size effects both with respect...... to the area of the rectangle and the side lengths of therectangle. Published rupture stress data for plain concrete beams illustrate the applicability of the derivedclosed form extreme value distributions as models for distributions of rupture stresses related to weakest linkmechanisms....

Evaluation of a main steam line break with induced, multiple tube ruptures: A comparison of NUREG 1477 (Draft) and transient methodologies Palo Verde Nuclear Generating Station

Energy Technology Data Exchange (ETDEWEB)

Parrish, K.R.

1995-09-01

This paper presents the approach taken to analyze the radiological consequences of a postulated main steam line break event, with one or more tube ruptures, for the Palo Verde Nuclear Generating Station. The analysis was required to support the restart of PVNGS Unit 2 following the steam generator tube rupture event on March 14, 1993 and to justify continued operation of Units 1 and 3. During the post-event evaluation, the NRC expressed concern that Unit 2 could have been operating with degraded tubes and that similar conditions could exist in Units 1 and 3. The NRC therefore directed that a safety assessment be performed to evaluate a worst case scenario in which a non-isolable main steam line break occurs inducing one or more tube failures in the faulted steam generator. This assessment was to use the generic approach described in NUREG 1477, Voltage-Based Interim Plugging Criteria for Steam Generator Tubes - Task Group Report. An analysis based on the NUREG approach was performed but produced unacceptable results for off-site and control room thyroid doses. The NUREG methodology, however, does not account for plant thermal-hydraulic transient effects, system performance, or operator actions which could be credited to mitigate dose consequences. To deal with these issues, a more detailed analysis methodology was developed using a modified version of the Combustion Engineering Plant Analysis Code, which examines the dose consequences for a main steam line break transient with induced tube failures for a spectrum equivalent to 1 to 4 double ended guillotine U-tube breaks. By incorporating transient plant system responses and operator actions, the analysis demonstrates that the off-site and control room does consequences for a MSLBGTR can be reduced to acceptable limits. This analysis, in combination with other corrective and recovery actions, provided sufficient justification for continued operation of PVNGS Units 1 and 3, and for the subsequent restart of Unit 2.

Evaluation of a main steam line break with induced, multiple tube ruptures: A comparison of NUREG 1477 (Draft) and transient methodologies Palo Verde Nuclear Generating Station

International Nuclear Information System (INIS)

Parrish, K.R.

1995-01-01

This paper presents the approach taken to analyze the radiological consequences of a postulated main steam line break event, with one or more tube ruptures, for the Palo Verde Nuclear Generating Station. The analysis was required to support the restart of PVNGS Unit 2 following the steam generator tube rupture event on March 14, 1993 and to justify continued operation of Units 1 and 3. During the post-event evaluation, the NRC expressed concern that Unit 2 could have been operating with degraded tubes and that similar conditions could exist in Units 1 and 3. The NRC therefore directed that a safety assessment be performed to evaluate a worst case scenario in which a non-isolable main steam line break occurs inducing one or more tube failures in the faulted steam generator. This assessment was to use the generic approach described in NUREG 1477, Voltage-Based Interim Plugging Criteria for Steam Generator Tubes - Task Group Report. An analysis based on the NUREG approach was performed but produced unacceptable results for off-site and control room thyroid doses. The NUREG methodology, however, does not account for plant thermal-hydraulic transient effects, system performance, or operator actions which could be credited to mitigate dose consequences. To deal with these issues, a more detailed analysis methodology was developed using a modified version of the Combustion Engineering Plant Analysis Code, which examines the dose consequences for a main steam line break transient with induced tube failures for a spectrum equivalent to 1 to 4 double ended guillotine U-tube breaks. By incorporating transient plant system responses and operator actions, the analysis demonstrates that the off-site and control room does consequences for a MSLBGTR can be reduced to acceptable limits. This analysis, in combination with other corrective and recovery actions, provided sufficient justification for continued operation of PVNGS Units 1 and 3, and for the subsequent restart of Unit 2

Bladder And Uterine Rupture At Vaginal Birth After Cesarean Section

African Journals Online (AJOL)

Rupture of the uterus is still a major obstetric problem in developing countries. The urinary bladder is often affected especially when a lower segment Caesarean scar ruptures. We present a case of bladder rupture associated with uterine rupture in a patient who was attempting vaginal delivery after two previous Caesarean ...

Radionuclide diagnosis of splenic rupture in infectious mononucleosis

International Nuclear Information System (INIS)

Vezina, W.C.; Nicholson, R.L.; Cohen, P.; Chamberlain, M.J.

1984-01-01

Spontaneous splenic rupture is a rare but serious complication of infectious mononucleosis. Although radionuclide spleen imaging is a well accepted method for diagnosis of traumatic rupture, interpretation can be difficult in the setting of mononucleosis, as tears may be ill-defined and diagnosis hampered by inhomogeneous splenic uptake. Four proven cases of spontaneous rupture are presented, three of which illustrate these diagnostic problems

Ruptured rectal duplication with urogenital abnormality: Unusual presentation

Directory of Open Access Journals (Sweden)

Shailesh Solanki

2015-01-01

Full Text Available Rectal duplication (RD accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD.

Aortic rupture complicating a fracture of an ankylosed thoracic spine. A case report.

Science.gov (United States)

Savolaine, E R; Ebraheim, N A; Stitgen, S; Jackson, W T

1991-11-01

A 34-year-old man was injured in a motorcycle accident and suffered both aortic rupture and thoracic spinal fracture, complicated by an underlying undetected ankylosing spondylitis. The latter disease can affect the integrity of vascular and spinal structure. Aortography is recommended as a high priority for the patient in an unstable cardiovascular condition requiring a definitive diagnosis. Aortic rupture and thoracic spine fracture may occur from high energy deceleration trauma. Motor vehicle passenger and pedestrian injuries are most commonly involved, although airline accidents and high falls also generate some cases. Mediastinal widening, displacement of esophagus and trachea, apical dissection of blood, and, especially, paravertebral pleural space widening are common to both injuries. Whereas most mediastinal hematomas are nonaortic in origin, a combined injury must be considered because clinical features may also overlap. These include hypotension (hypovolemic or spinal shock), paraplegia, and severe back pain. In light of the high mortality and time constraints associated with aortic rupture, immediate diagnostic resolution is necessary for appropriate management and priority of investigation.

Spontaneous distal rupture of the plantar fascia.

Science.gov (United States)

Gitto, Salvatore; Draghi, Ferdinando

2018-07-01

Spontaneous ruptures of the plantar fascia are uncommon injuries. They typically occur at its calcaneal insertion and usually represent a complication of plantar fasciitis and local treatment with steroid injections. In contrast, distal ruptures commonly result from traumatic injuries. We describe the case of a spontaneous distal rupture of the plantar fascia in a 48-year-old woman with a low level of physical activity and no history of direct injury to the foot, plantar fasciitis, or steroid injections. © 2017 Wiley Periodicals, Inc.

Ruptured Uterus At Afikpo, Southeast Nigeria. | Eze | Ebonyi Medical ...

African Journals Online (AJOL)

Context: Ruptured uterus is an obstetric catastrophe associated with high maternal and perinatal mortality. Objectives: To determine the incidence, causes, management and fetomaternal outcomes of ruptured uterus in Afikpo, Southeast Nigeria. Methods: Delivery records, theatre registers and case notes of all ruptured ...

Location of Ruptured Bullae in Secondary Spontaneous Pneumothorax

Directory of Open Access Journals (Sweden)

Jinseok Choi

2017-12-01

Full Text Available Background: The surgical treatment of secondary spontaneous pneumothorax (SSP can be complicated by fragile lung parenchyma. The preoperative prediction of air leakage could help prevent intraoperative lung in-jury during manipulation of the lung. Common sites of bulla development and ruptured bullae were inves-tigated based on computed tomography (CT and intraoperative findings. Methods: The study enrolled 208 patients with SSP who underwent air leak control through video-assisted thoracoscopic surgery (VATS. We retrospectively reviewed the sites of bulla development on preoperative CT and the rupture sites during VATS. Results: Of the 135 cases of right-sided SSP, the most common rupture site was the apical segment (31.9%, followed by the azygoesophageal recess (27.4%. Of the 75 cases on the left side, the most com-mon rupture site was the apical segment (24.0%, followed by the anterior basal segment (17.3%. Conclusion: The azygoesophageal recess and parenchyma along the cardiac border were common sites of bul-la development and rupture. Studies of respiratory lung motion to measure the pleural pressure at the lung surface could help to determine the relationship between cardiogenic and diaphragmatic movement and bulla formation or rupture.

Detection of thrombosis and plaque rupture in atherosclerotic rabbit model by using 3.0 T MR imaging

International Nuclear Information System (INIS)

Ma Xiaohai; Zhang Zhaoqi; Zhao Lei; Zhao Quanming; Shang Jianfeng; Feng Tingting; Zeng Conghe

2011-01-01

Objective: To explore the imaging of the thrombosis after pharmacological triggering of plaque rupture in atherosclerotic rabbit model by using 3.0 T high-resolution magnetic resonance imaging. Methods: Twenty male New Zealand white rabbits were divided into an experimental group (n=16) and a control group (n=4). The aortic wall injuries were induced by an intravascular balloon in experimental group rabbits after high cholesterol diet. The pharmacological triggering with Russell's viper venom and histamine was performed after 3 months of establishment of model. All of the animals underwent pre-trigger and post-trigger MR examinations including 3D time of fight (3D TOF), T 1 WI, T 2 WI and post contrast T 1 WI. Euthanasia was performed in all rabbits and gross anatomy and histological specimen of aorta were obtained. Comparing the location and length of the thrombus between MRI images and histopathology was used Pearson test. Comparing the calculated indexes of abdominal aorta between rabbits with and without thrombosis was used AVONA test and LSD-t test. Results: After triggering, 8 in 14 survived rabbits developed thrombosis in experimental group, meanwhile, no thrombus was found in control group. The accuracy of multi-sequences MRI for detecting of thrombus was 87.1% (27/31). MRI data correlated with the histopathology regarding thrombus length (r=0.85, P 2 vs. (8.93±5.36) mm 2 , P<0.01]. Conclusion: MRI is useful tool to determine the thrombosis and plaque rupture in atherosclerotic rabbit model. (authors)

Metallurgical analysis of high pressure gas pipelines rupture

International Nuclear Information System (INIS)

Hasan, F.; Ahmed, F.

2007-01-01

On 6 July 2004, two parallel-running gas pipelines (18-inch and 24-inch diameters), in the main transmission network of SNGPL (a gas company in Pakistan) were ruptured. The ruptures occurred in the early hours of the morning about 8 miles downstream of the compressor station AC-4. The ruptures were indicated by the increased gas flow at the outlet of AC-4 (1), first at about 0648 hours and then again about 20 minutes later. The gas escaping from the ruptured lines had caught fire, and the flames had also 'affected' a third parallel-running pipeline of 30-inch diameter, lying next to the 24-inch line. The metallurgical examination of the two ruptured lines showed that the 24-inch line was ruptured with the help of an explosive device that had been placed on the underside of the pipe. An examination of the 18-inch line showed that this pipe had failed as a result of the heating of the pipe-wall, presumably, by the flame emanating from the 24-inch line. These two observations clearly suggested that the 24-inch line was the first to rupture (by explosives), and the fire following this rupture had heated the 18-inch pipe to a temperature where its yield strength was unable to support the inside gas pressure. The 20 minutes time interval between the two ruptures was obviously the time taken by the 18 inch pipe to be heated upto the level where it started to yield. The 30-inch line lying next to the 24-inch line was affected to the extent that its coating had been burnt-off over a length of about 40-50 feet. However, the pipe did not exhibit any signs of deshaping or deformation what-so-ever. A replica metallographic examination indicated that the microstructure of the pipe was not measurably affected by the heat. It was thus decided not to replace the affected part of the 30-inch pipe, but only to re-coat this affected portion. (author)

On the unit rupture work of metals and alloys

International Nuclear Information System (INIS)

Verkhoturov, A.D.; Kovalenko, V.S.; Dyatel, V.P.

1980-01-01

Studied is the effect of the nature of the treated material treatment regimes on their unit rupture work at laser treatment in the regime of quasistationary evaporation. It is shown that the unit rupture work changes its values depending on the treatment regimes, coincidences between experimental and calculation values of unit rupture work are not being observed, especially for refractory metals of the 6th group and for solid alloys. Established are optimum regimes for determination of stable values of unit rupture work

Neighbor Rupture Degree of Some Middle Graphs

Directory of Open Access Journals (Sweden)

Gökşen BACAK-TURAN

2017-12-01

Full Text Available Networks have an important place in our daily lives. Internet networks, electricity networks, water networks, transportation networks, social networks and biological networks are some of the networks we run into every aspects of our lives. A network consists of centers connected by links. A network is represented when centers and connections modelled by vertices and edges, respectively. In consequence of the failure of some centers or connection lines, measurement of the resistance of the network until the communication interrupted is called vulnerability of the network. In this study, neighbor rupture degree which is a parameter that explores the vulnerability values of the resulting graphs due to the failure of some centers of a communication network and its neighboring centers becoming nonfunctional were applied to some middle graphs and neighbor rupture degree of the $M(C_{n},$ $M(P_{n},$ $M(K_{1,n},$ $M(W_{n},$ $M(P_{n}\\times K_{2}$ and $M(C_{n}\\times K_{2}$ have been found.

A fast prediction of plant behaviour in the steam generator tube rupture accident at Mihama unit 2 using a similar case

International Nuclear Information System (INIS)

Gofuku, Akio; Tanaka, Yutaka; Numoto, Atsushi; Yoshikawa, Hidekazu.

1996-01-01

It is important to predict fast and accurately future trend of behaviour of a nuclear power plant in an emergency situation. The case-based reasoning is a strong tool for this purpose because it solves a problem by effectively using past similar cases. This study investigates the applicability of the case-based reasoning as a fast prediction technique of plant behaviour. This paper discusses a prediction of initial plant behaviour in the steam generator tube rupture accident happened at the Mihama nuclear power plant unit 2 by using the behaviour data of an accident of the same type happened at Prairie Island nuclear power plant unit 1. The prediction results coincide well with the reported plant behaviour although there are several important differences in the detailed plant specifications and operator actions between the two SGTR accidents. (author)

Treatment Alternative for Irreparable Rotator Cuff Ruptures ...

African Journals Online (AJOL)

2016-09-03

Sep 3, 2016 ... and such ruptures also lead to a pseudo-paralysis.[1,2]. Pain during daily ... 2) repairable rotator cuff rupture, as determined on MRI and during arthroscopy ..... functioning and lead to cosmetic deformities.[4]. Arthroplasty is a ...

Achilles Tendon Rupture

Science.gov (United States)

... is a strong fibrous cord that connects the muscles in the back of your calf to your heel bone. If you overstretch your Achilles tendon, it can tear (rupture) completely or just partially. If your Achilles ...

Incidence of plantar fascia ruptures following corticosteroid injection.

Science.gov (United States)

Kim, Chul; Cashdollar, Michael R; Mendicino, Robert W; Catanzariti, Alan R; Fuge, LaDonna

2010-12-01

Plantar fasciitis is commonly treated with corticosteroid injections to decrease pain and inflammation. Therapeutic benefits often vary in terms of efficacy and duration. Rupture of the plantar fascia has been reported as a possible complication following corticosteroid injection. A retrospective chart review of 120 patients who received corticosteroid injection for plantar fasciitis was performed at the authors' institution to determine the incidence of plantar fascia rupture. The plantar fascia rupture was diagnosed clinically and confirmed with magnetic resonance imaging. Various factors were analyzed, including the number of injections, interval between injections, body mass index (BMI), and activity level. Four patients (2.4%) consequently experienced plantar fascia rupture following an average of 2.67 injections. The average BMI of these patients was 38.6 kg/m². The authors conclude that corticosteroid injection therapy appears to be a safe and effective form of nonoperative treatment with minimal complications and a relatively low incident of plantar fascia rupture.

Discussion on amount of water ingress mass in steam generator heat-exchange tube rupture accident of high- temperature gas-cooled reactor

International Nuclear Information System (INIS)

Wang Yan; Zheng Yanhua; Shi Lei; Li Fu; Sun Ximing

2009-01-01

The steam generator heat-exchange tube rupture (SGTR) accident which will result in the water ingress to the primary circuit of reactor is an important and particular accident for high-temperature gas-cooled reactor (HTGR). The analysis of the water ingress accident is significant for verifying the inherent safety characteristics of HTGR. The amount of water ingress mass is one of the decisive factors for the seriousness of the accident consequence. The 250 MW Pebble-bed Modular High-Temperature Gas-cooled Reactor (HTR-PM) designed by Institute of Nuclear and New Energy Technology of Tsinghua University was selected as an example of analysis. The analysis results show that the amount of water ingress mass is not only affected directly with the broken position and the broken area of the tubes, but also related with the diameter of draining piping and restrictor, draining control valve, action setting of emptier system. With reasonable parameters chosen, the water in steam generator could be drained effectively, so it will prevent the primary circuit of reactor from water ingress in large quantity and reduce the radioactive isotopes ingress to the secondary circuit. (authors)

Auxiliary Deep Generative Models

DEFF Research Database (Denmark)

Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

2016-01-01

Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... the generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

Micromechanical properties and collagen composition of ruptured human achilles tendon

DEFF Research Database (Denmark)

Hansen, Philip; Kovanen, Vuokko; Hölmich, Per

2013-01-01

The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive.......The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive....

Vortex dynamics in ruptured and unruptured intracranial aneurysms

Science.gov (United States)

Trylesinski, Gabriel

Intracranial aneurysms (IAs) are a potentially devastating pathological dilation of brain arteries that affect 1.5-5 % of the population. Causing around 500 000 deaths per year worldwide, their detection and treatment to prevent rupture is critical. Multiple recent studies have tried to find a hemodynamics predictor of aneurysm rupture, but concluded with distinct opposite trends using Wall Shear Stress (WSS) based parameters in different clinical datasets. Nevertheless, several research groups tend to converge for now on the fact that the flow patterns and flow dynamics of the ruptured aneurysms are complex and unstable. Following this idea, we investigated the vortex properties of both unruptured and ruptured cerebral aneurysms. A brief comparison of two Eulerian vortex visualization methods (Q-criterion and lambda 2 method) showed that these approaches gave similar results in our complex aneurysm geometries. We were then able to apply either one of them to a large dataset of 74 patient specific cases of intracranial aneurysms. Those real cases were obtained by 3D angiography, numerical reconstruction of the geometry, and then pulsatile CFD simulation before post-processing with the mentioned vortex visualization tools. First we tested the two Eulerian methods on a few cases to verify their implementation we made as well as compare them with each other. After that, the Q-criterion was selected as method of choice for its more obvious physical meaning (it shows the balance between two characteristics of the flow, its swirling and deformation). Using iso-surfaces of Q, we started by categorizing the patient-specific aneurysms based on the gross topology of the aneurysmal vortices. This approach being unfruitful, we found a new vortex-based characteristic property of ruptured aneurysms to stratify the rupture risk of IAs that we called the Wall-Kissing Vortices, or WKV. We observed that most ruptured aneurysms had a large amount of WKV, which appears to agree with

Simultaneous bilateral patellar tendon rupture ?

OpenAIRE

Moura, Diogo Lino; Marques, Jos? Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

2016-01-01

Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a s...

Definitive diagnosis of breast implant rupture using magnetic resonance imaging.

Science.gov (United States)

Ahn, C Y; Shaw, W W; Narayanan, K; Gorczyca, D P; Sinha, S; Debruhl, N D; Bassett, L W

1993-09-01

Breast implant rupture is an important complication of augmented and reconstructed breasts. Although several techniques such as mammography, xeromammography, ultrasound, thermography, and computed tomographic (CT) scanning have been proven to be useful to detect implant rupture, they have several disadvantages and lack specificity. In the current study, we have established magnetic resonance imaging (MRI) as a definitive, reliable, and reproducible technique to diagnose both intracapsular and extracapsular ruptures. The study was conducted in 100 symptomatic patients. Our imaging parameters were able to identify ruptures in implants with silicone shells. All the ruptures showed the presence of wavy lines, free-floating silicone shell within the gel ("free-floating loose-thread sign" or "linguine sign"). We had a 3.75 percent incidence of false-positive and false-negative results. The sensitivity for detection of silicone implant rupture was 76 percent, with a specificity of 97 percent. In addition, we also were able to identify the artifacts that may interfere with the definitive diagnosis of implant rupture.

Solving the dynamic rupture problem with different numerical approaches and constitutive laws

Science.gov (United States)

Bizzarri, A.; Cocco, M.; Andrews, D.J.; Boschi, Enzo

2001-01-01

We study the dynamic initiation, propagation and arrest of a 2-D in-plane shear rupture by solving the elastodynamic equation by using both a boundary integral equation method and a finite difference approach. For both methods we adopt different constitutive laws: a slip-weakening (SW) law, with constant weakening rate, and rate- and state-dependent friction laws (Dieterich-Ruina). Our numerical procedures allow the use of heterogeneous distributions of constitutive parameters along the fault for both formulations. We first compare the two solution methods with an SW law, emphasizing the required stability conditions to achieve a good resolution of the cohesive zone and to avoid artificial complexity in the solutions. Our modelling results show that the two methods provide very similar time histories of dynamic source parameters. We point out that, if a careful control of resolution and stability is performed, the two methods yield identical solutions. We have also compared the rupture evolution resulting from an SW and a rate- and state-dependent friction law. This comparison shows that despite the different constitutive formulations, a similar behaviour is simulated during the rupture propagation and arrest. We also observe a crack tip bifurcation and a jump in rupture velocity (approaching the P-wave speed) with the Dieterich-Ruina (DR) law. The rupture arrest at a barrier (high strength zone) and the barrier-healing mechanism are also reproduced by this law. However, this constitutive formulation allows the simulation of a more general and complex variety of rupture behaviours. By assuming different heterogeneous distributions of the initial constitutive parameters, we are able to model a barrier-healing as well as a self-healing process. This result suggests that if the heterogeneity of the constitutive parameters is taken into account, the different healing mechanisms can be simulated. We also study the nucleation phase duration Tn, defined as the time

Frequency, predisposing factors and fetomaternal outcome in uterine rupture

International Nuclear Information System (INIS)

Malik, H.S.

2006-01-01

To determine the frequency and to analyze the predisposing factors, maternal and fetal outcome of uterine rupture. All cases of ruptured uterus, who were either admitted with or who developed this complication in the hospital, were included in the study. Demographic data, details regarding the most probable predisposing factor, type of rupture, the management and maternal and fetal outcome were taken into consideration for analysis.During three years, total number of deliveries was 18668, and there were 103 cases of uterine rupture (0.55%).Out of these, only 13 (12.62%) patients were booked. Most of the patients presented between the ages of 26-30 years (42.71%). Majority of ruptures occurred in para 2-4 (44.66%). Fifty five cases (53.39%) had a previous caesarean section scar. In 68 (66.01%) cases, the tear was located in lower uterine segment. In 93 (90.29%) cases, anterior uterine wall was involved. Rupture was complete in 79 (76.69%)cases. Repair of uterus was done in 79 (76.69%) cases. Hysterectomy was performed in 24 (23.30%) cases. There were 8 (7.76% or 77.66/1000) maternal deaths and 85 (81.73% or 825 / 1000) perinatal deaths.This study confirms high frequency of such serious preventable obstetrical problem which can lead to high fetomaternal mortality. Rupture of caesarean section scar was the most common cause of uterine rupture found in this series. (author)

Rupture process of the 2016 Mw 7.8 Ecuador earthquake from joint inversion of InSAR data and teleseismic P waveforms

Science.gov (United States)

Yi, Lei; Xu, Caijun; Wen, Yangmao; Zhang, Xu; Jiang, Guoyan

2018-01-01

The 2016 Ecuador earthquake ruptured the Ecuador-Colombia subduction interface where several historic megathrust earthquakes had occurred. In order to determine a detailed rupture model, Interferometric Synthetic Aperture Radar (InSAR) images and teleseismic data sets were objectively weighted by using a modified Akaika's Bayesian Information Criterion (ABIC) method to jointly invert for the rupture process of the earthquake. In modeling the rupture process, a constrained waveform length method, unlike the traditional subjective selected waveform length method, was used since the lengths of inverted waveforms were strictly constrained by the rupture velocity and rise time (the slip duration time). The optimal rupture velocity and rise time of the earthquake were estimated from grid search, which were determined to be 2.0 km/s and 20 s, respectively. The inverted model shows that the event is dominated by thrust movement and the released moment is 5.75 × 1020 Nm (Mw 7.77). The slip distribution extends southward along the Ecuador coast line in an elongated stripe at a depth between 10 and 25 km. The slip model is composed of two asperities and slipped over 4 m. The source time function is approximate 80 s that separated into two segments corresponding to the two asperities. The small magnitude of the slip occurred in the updip section of the fault plane resulted in small tsunami waves that were verified by observations near the coast. We suggest a possible situation that the rupture zone of the 2016 earthquake is likely not overlapped with that of the 1942 earthquake.

Development of leak-rupture criteria for axially through-wall cracked pipelines

Energy Technology Data Exchange (ETDEWEB)

Zhu, X.K.; Leis, B.N. [Battelle Memorial Inst., Columbus, OH (United States)

2009-07-01

In this study, J-integral based fracture mechanics were used to characterize the fracture behaviour of a pipeline from crack initiation and stable growth to tearing instability. The aim of the study was to develop an effective leak-rupture criterion for pipelines with axial through-wall cracks (TWC). The J driving force for cracked plates and pipes was estimated using a plastic influence function method. The EPRI estimation scheme and R6 method were used to obtain a general estimate of the J-integral of the pipe. The failure pressures of a TWC pipe at fracture initiation and instability were then modelled in order to define a leak-rupture boundary. Fracture initiation and instability analyses for the TWC pipeline were illustrated. Results of the study showed that the method can be used to improve the accuracy of J driving force estimation and the leak-rupture criterion for pipeline applications. 20 refs., 5 figs.

Experimental and numerical studies of the effect of plasticity mechanisms on the brittle rupture by cleavage in low alloy steels; Etudes experimentale et numerique de l'effet des mecanismes de plasticite sur la rupture fragile par clivage dans les aciers faiblement allies

Energy Technology Data Exchange (ETDEWEB)

Libert, M

2007-09-15

It is indispensable to guarantee the integrity of PWR reactor vessels during an accidental running: in this context, the understanding and the modelling of the mechanisms of brittle rupture of steels are decisive elements of the complicated estimation of the service life of reactor vessels. The models of local approach of rupture by cleavage are one of the main tools of anticipation of the tensile strength of low alloy steels. In this work, the effect of the stresses heterogeneities in a local criteria of initiation of cleavage has been taken into account. The results of the microstructure calculations are used for proposing a statistical description of the local stresses distribution evolution. This statistical approach allows to propose a local approach model of the rupture depending both of the mechanical heterogeneities and of the sizes distributions of the defects. The behaviour of the material and its evolution are characterized at the microscopic and macroscopic scales in the temperature range [25 C, -196 C]. Simple tensile tests, velocity and temperature rises tests and toughness tests have been carried out. A micro-mechanical behaviour model describing the plastic behaviour below the transition temperature T{sub a} has been proposed. The behaviour law is based on the deformation mechanisms described in bibliography and identified by an inverse method from mechanical tests. The TEM observations and the characterization of the behaviour thermally activated allow to determine several parameters of the model. Simulations are carried out in order to model the main stress distributions {sigma}{sub 1} in two bainite microstructures corresponding to the elementary volume of the local approach of the rupture. The temperature and the triaxiality effects on the evolutions of the heterogeneities is characterized. A distribution function describing the distribution of the local values of {sigma}{sub 1} in terms of the main and equivalent mean stresses {sigma}{sub 1

Experimental and numerical studies of the effect of plasticity mechanisms on the brittle rupture by cleavage in low alloy steels; Etudes experimentale et numerique de l'effet des mecanismes de plasticite sur la rupture fragile par clivage dans les aciers faiblement allies

Energy Technology Data Exchange (ETDEWEB)

Libert, M

2007-09-15

It is indispensable to guarantee the integrity of PWR reactor vessels during an accidental running: in this context, the understanding and the modelling of the mechanisms of brittle rupture of steels are decisive elements of the complicated estimation of the service life of reactor vessels. The models of local approach of rupture by cleavage are one of the main tools of anticipation of the tensile strength of low alloy steels. In this work, the effect of the stresses heterogeneities in a local criteria of initiation of cleavage has been taken into account. The results of the microstructure calculations are used for proposing a statistical description of the local stresses distribution evolution. This statistical approach allows to propose a local approach model of the rupture depending both of the mechanical heterogeneities and of the sizes distributions of the defects. The behaviour of the material and its evolution are characterized at the microscopic and macroscopic scales in the temperature range [25 C, -196 C]. Simple tensile tests, velocity and temperature rises tests and toughness tests have been carried out. A micro-mechanical behaviour model describing the plastic behaviour below the transition temperature T{sub a} has been proposed. The behaviour law is based on the deformation mechanisms described in bibliography and identified by an inverse method from mechanical tests. The TEM observations and the characterization of the behaviour thermally activated allow to determine several parameters of the model. Simulations are carried out in order to model the main stress distributions {sigma}{sub 1} in two bainite microstructures corresponding to the elementary volume of the local approach of the rupture. The temperature and the triaxiality effects on the evolutions of the heterogeneities is characterized. A distribution function describing the distribution of the local values of {sigma}{sub 1} in terms of the main and equivalent mean stresses {sigma}{sub 1

Bacteria localization and chorion thinning among preterm premature rupture of membranes.

Directory of Open Access Journals (Sweden)

Kimberly B Fortner

Full Text Available OBJECTIVE: Bacterial colonization of the fetal membranes and its role in pathogenesis of membrane rupture is poorly understood. Prior retrospective work revealed chorion layer thinning in preterm premature rupture of membranes (PPROM subjects. Our objective was to prospectively examine fetal membrane chorion thinning and to correlate to bacterial presence in PPROM, preterm, and term subjects. STUDY DESIGN: Paired membrane samples (membrane rupture and membrane distant were prospectively collected from: PPROM = 14, preterm labor (PTL = 8, preterm no labor (PTNL = 8, term labor (TL = 10, and term no labor (TNL = 8, subjects. Sections were probed with cytokeratin to identify fetal trophoblast layer of the chorion using immunohistochemistry. Fluorescence in situ hybridization was performed using broad range 16 s ribosomal RNA probe. Images were evaluated, chorion and choriodecidua were measured, and bacterial fluorescence scored. Chorion thinning and bacterial presence were compared among and between groups using Student's t-test, linear mixed effect model, and Poisson regression model (SAS Cary, NC. RESULTS: In all groups, the fetal chorion cellular layer was thinner at rupture compared to distant site (147.2 vs. 253.7 µm, p<0.0001. Further, chorion thinning was greatest among PPROM subjects compared to all other groups combined, regardless of site sampled [PPROM(114.9 vs. PTL(246.0 vs. PTNL(200.8 vs. TL(217.9 vs. TNL(246.5]. Bacteria counts were highest among PPROM subjects compared to all other groups regardless of site sampled or histologic infection [PPROM(31 vs. PTL(9 vs. PTNL(7 vs. TL(7 vs. TNL(6]. Among all subjects at both sites, bacterial counts were inversely correlated with chorion thinning, even excluding histologic chorioamnionitis (p<0.0001 and p = 0.05. CONCLUSIONS: Fetal chorion was uniformly thinner at rupture site compared to distant sites. In PPROM fetal chorion, we demonstrated pronounced global thinning

Rupture of steam lines between blocks D and G

International Nuclear Information System (INIS)

1999-01-01

Analysis of steam lines rupture between blocks D and G of Ignalina NPP was performed. Model for evaluation of thermo hydrodynamic parameters was developed. Structural analysis of the shaft building was done as well. State of the art codes such as RELAP5, ALGOR, NEPTUNE were used in these calculations

Misdiagnosed Uterine Rupture of an Advanced Cornual Pregnancy

Directory of Open Access Journals (Sweden)

Christian Linus Hastrup Sant

2012-01-01

Full Text Available Cornual pregnancy is a diagnostic and therapeutic challenge with potential severe consequences if uterine rupture occurs with following massive intraabdominal bleeding. We report a case of a misdiagnosed ruptured cornual pregnancy occurring at 21 weeks of gestation. Ultrasound examination and computer tomography revealed no sign of abnormal pregnancy. The correct diagnosis was first made at emergency laparotomy. Uterine rupture should be considered in pregnant women presenting with abdominal pain and haemodynamic instability.

Misdiagnosed uterine rupture of an advanced cornual pregnancy

DEFF Research Database (Denmark)

Sant, Christian Linus Hastrup; Andersen, Poul Erik

2012-01-01

Cornual pregnancy is a diagnostic and therapeutic challenge with potential severe consequences if uterine rupture occurs with following massive intraabdominal bleeding. We report a case of a misdiagnosed ruptured cornual pregnancy occurring at 21 weeks of gestation. Ultrasound examination...... and computer tomography revealed no sign of abnormal pregnancy. The correct diagnosis was first made at emergency laparotomy. Uterine rupture should be considered in pregnant women presenting with abdominal pain and haemodynamic instability....

Spontaneous rupture of choledochal cyst: case report

International Nuclear Information System (INIS)

Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young

2002-01-01

Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued

Spontaneous rupture of choledochal cyst: case report

Energy Technology Data Exchange (ETDEWEB)

Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

2002-11-01

Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

Ultrasonogram of tubal pregnancy: Unruptured or ruptured?

International Nuclear Information System (INIS)

Lee, Hee Jung; Kim, Jung Sik; Lee, Sung Moon; Kim, Hong; Woo, Seong Ku; Yeun, Seong Do; Lee, Doo Ryong

1993-01-01

To evaluate the usefulness of ultrasonography in the differentiation of the unruptured ones, we performed prospective ultrasonographic study in 56 patients with tubal pregnancy and subsequently correlated with the surgical (45 cases) and laparoscopic (11 cases) findings. The criterion for unruptured tubal pregnancy was the visualization of extra uterine gestational sac or a mass that was separated from the ipsilateral ovary. All cases were confirmed surgically or laparoscopically within 48 hours after sonographic examination. Forty five (80%)cases were proved as unruptured, tubal pregnancy, while 11 (20%) as ruptured one. Extra uterine gestational sac was seen in 31/45 (69%) in unruptured group and 2/11 (18%) in ruptured group. A mass separated from the ipsilateral ovary was seen in 7 unruptured tubal pregnancies and 2 ruptured pregnancies. A mass that was not separated from the ipsilateral ovary was seen in 13 cases. Seven of these were ruptured pregnancies, while 6 were unrupture dones. Using our criteria, the unruptured tubal pregnancy was diagnosed with a sensitivity of 84%, a specificity of 64%, an accuracy of 80%, a positive predictive value of 90% and a negative predictive value of 50%. We conclude that ultrasonography is useful in the differentiation of the unruptured tubal pregnancy from the ruptured one

W-phase estimation of first-order rupture distribution for megathrust earthquakes

Science.gov (United States)

Benavente, Roberto; Cummins, Phil; Dettmer, Jan

2014-05-01

Estimating the rupture pattern for large earthquakes during the first hour after the origin time can be crucial for rapid impact assessment and tsunami warning. However, the estimation of coseismic slip distribution models generally involves complex methodologies that are difficult to implement rapidly. Further, while model parameter uncertainty can be crucial for meaningful estimation, they are often ignored. In this work we develop a finite fault inversion for megathrust earthquakes which rapidly generates good first order estimates and uncertainties of spatial slip distributions. The algorithm uses W-phase waveforms and a linear automated regularization approach to invert for rupture models of some recent megathrust earthquakes. The W phase is a long period (100-1000 s) wave which arrives together with the P wave. Because it is fast, has small amplitude and a long-period character, the W phase is regularly used to estimate point source moment tensors by the NEIC and PTWC, among others, within an hour of earthquake occurrence. We use W-phase waveforms processed in a manner similar to that used for such point-source solutions. The inversion makes use of 3 component W-phase records retrieved from the Global Seismic Network. The inverse problem is formulated by a multiple time window method, resulting in a linear over-parametrized problem. The over-parametrization is addressed by Tikhonov regularization and regularization parameters are chosen according to the discrepancy principle by grid search. Noise on the data is addressed by estimating the data covariance matrix from data residuals. The matrix is obtained by starting with an a priori covariance matrix and then iteratively updating the matrix based on the residual errors of consecutive inversions. Then, a covariance matrix for the parameters is computed using a Bayesian approach. The application of this approach to recent megathrust earthquakes produces models which capture the most significant features of

Radiologic findings of small bowel rupture due to blunt abdominal trauma

International Nuclear Information System (INIS)

Ha, Hyeon Kweun; Bahk, Yong Whee

1987-01-01

Bowel rupture due to blunt abdominal trauma is no longer rare, and is among the most challenging problems that confront the physicians and radiologists. It is frequently difficult to diagnose because the symptoms may be trivial during the early stage and masked by more obvious, but less lethal injuries. It is well known that the roentgen examination of the abdomen is also of little value to exclude bowel rupture because of infrequency of positive findings and free gas. The plain films of 23 cases of jejunal rupture and 8 cases of ileal rupture were evaluated to sort and diagnostic features of small bowel rupture caused by blunt abdominal trauma. 1. Free intraperitoneal gas was noted in 6 cases of jejunal rupture (26%) and 1 case of ileal rupture (13%), and definite radiological evidence of free intraperitoneal fluid was present in 16 cases of patients (52%). 2. The contour change of bowel loops such as tapering or indentation were seen in 11 cases of patients (36%), and local opacity along the mesenteric root axis was demonstrated in 19 cases of patients (61%). 3. Paralytic ileus was localized to LUQ in jejunal rupture and to mid-abdomen in ileal rupture, and gastric and transverse-colon distension with gas was noticeable especially in jejunal rupture

Tsunami inundation variability from stochastic rupture scenarios: Application to multiple inversions of the 2011 Tohoku, Japan earthquake

KAUST Repository

Mori, Nobuhito

2017-06-28

We develop a framework for assessing the sensitivity and variability of tsunami inundation characteristics for stochastic physics-based scenarios of mega-thrust subduction earthquakes. The method is applied to the 2011 Tohoku, Japan earthquake, and tested against observed inundation maps at several locations along the Tohoku coast, using 11 different, previously published, rupture models for this devastating tsunamgenic earthquake. The earthquake rupture models differ in fault dimension (length and width), geometry (dip, strike and top-edge depth), as well as asperity characteristics (slip heterogeneity on the fault plane). The resulting source variability allows exploring a wide range of tsunami scenarios for an Mw9 mega-thrust subduction earthquake in the Tohoku region to conduct thorough sensitivity analyses and to quantify the inundation variability. The numerical results indicate a strong influence of the reference source models on inundation variability, and demonstrate significant sensitivity of inundation to the details of the rupture realization. Therefore, relying on a single particular earthquake rupture model as a representative case when varying earthquake source characteristics may lead to under-representation of the variability of potential scenarios. Moreover, the proposed framework facilitates the rigorous development of critical scenarios for tsunami hazard and risk assessments, which are particularly useful for tsunami hazard mapping and disaster preparedness planning.

Spontaneous rupture of vaginal enterocele

DEFF Research Database (Denmark)

Svendsen, J H; Galatius, H; Hansen, P K

1985-01-01

Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission.......Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission....

Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace

Science.gov (United States)

Scharer, Katherine M.; Weldon, Ray; Streig, Ashley; Fumal, Thomas

2014-01-01

Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized earthquakes exert a strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) on the southern San Andreas Fault (SSAF), but an outstanding question is whether the 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturing earthquakes on the Big Bend of the SSAF restrict the pattern of possible ruptures on the 1857 stretch of the fault. In conjunction with existing sites, we show that over the last ~650 years, at least 75% of the surface ruptures are shorter than the 1857 earthquake, with estimated rupture lengths of 100 to <300 km. These results suggest that the 1857 rupture was unusual, perhaps leading to the long open interval, and that a return to pre-1857 behavior would increase the rate of M7.3–M7.7 earthquakes.

Semi-Supervised Generation with Cluster-aware Generative Models

DEFF Research Database (Denmark)

Maaløe, Lars; Fraccaro, Marco; Winther, Ole

2017-01-01

Deep generative models trained with large amounts of unlabelled data have proven to be powerful within the domain of unsupervised learning. Many real life data sets contain a small amount of labelled data points, that are typically disregarded when training generative models. We propose the Clust...... a log-likelihood of −79.38 nats on permutation invariant MNIST, while also achieving competitive semi-supervised classification accuracies. The model can also be trained fully unsupervised, and still improve the log-likelihood performance with respect to related methods.......Deep generative models trained with large amounts of unlabelled data have proven to be powerful within the domain of unsupervised learning. Many real life data sets contain a small amount of labelled data points, that are typically disregarded when training generative models. We propose the Cluster...

Isolated gallbladder rupture following blunt abdominal injury

African Journals Online (AJOL)

2015-05-26

May 26, 2015 ... Kaohsiung Medical University, Kaohsiung, Taiwan. Abstract. Isolated traumatic gallbladder rupture subsequent to blunt abdominal injury is rare. Most literatures on the subjects consist of case reports. We reported a rare case of isolated gallbladder rupture and discussed the possible predisposing factors to ...

Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

African Journals Online (AJOL)

Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

General model for Pc-based simulation of PWR and BWR plant components

Energy Technology Data Exchange (ETDEWEB)

Ratemi, W M; Abomustafa, A M [Faculty of enginnering, alfateh univerity Tripoli, (Libyan Arab Jamahiriya)

1995-10-01

In this paper, we present a basic mathematical model derived from physical principles to suit the simulation of PWR-components such as pressurizer, intact steam generator, ruptured steam generator, and the reactor component of a BWR-plant. In our development, we produced an NMMS-package for nuclear modular modelling simulation. Such package is installed on a personal computer and it is designed to be user friendly through color graphics windows interfacing. The package works under three environments, namely, pre-processor, simulation, and post-processor. Our analysis of results using cross graphing technique for steam generator tube rupture (SGTR) accident, yielded a new proposal for on-line monitoring of control strategy of SGTR-accident for nuclear or conventional power plant. 4 figs.

Plantar fascia rupture in a professional soccer player.

Science.gov (United States)

Suzue, Naoto; Iwame, Toshiyuki; Kato, Kenji; Takao, Shoichiro; Tateishi, Tomohiko; Takeda, Yoshitsugu; Hamada, Daisuke; Goto, Tomohiro; Takata, Yoichiro; Matsuura, Tetsuya; Sairyo, Koichi

2014-01-01

We report the case of a 29-year-old male professional soccer player who presented with symptoms of plantar fasciitis. His symptoms occurred with no remarkable triggers and gradually worsened despite conservative treatments including taping, use of insoles, and physical therapy. Local corticosteroid injection was given twice as a further intervention, but his plantar fascia partially ruptured 49 days after the second injection. He was treated conservatively with platelet-rich plasma, and magnetic resonance imaging showed regenerative change of the ruptured fascia. Five months after the rupture, he returned to his original level of training. If professional athletes find it difficult to refrain from athletic activity, as in the present case, the risk of rupture due to corticosteroid injection should not be overlooked.

Creep Rupture Life Prediction Based on Analysis of Large Creep Deformation

Directory of Open Access Journals (Sweden)

YE Wenming

2016-08-01

Full Text Available A creep rupture life prediction method for high temperature component was proposed. The method was based on a true stress-strain elastoplastic creep constitutive model and the large deformation finite element analysis method. This method firstly used the high-temperature tensile stress-strain curve expressed by true stress and strain and the creep curve to build materials' elastoplastic and creep constitutive model respectively, then used the large deformation finite element method to calculate the deformation response of high temperature component under a given load curve, finally the creep rupture life was determined according to the change trend of the responsive curve.The method was verified by durable test of TC11 titanium alloy notched specimens under 500 ℃, and was compared with the three creep rupture life prediction methods based on the small deformation analysis. Results show that the proposed method can accurately predict the high temperature creep response and long-term life of TC11 notched specimens, and the accuracy is better than that of the methods based on the average effective stress of notch ligament, the bone point stress and the fracture strain of the key point, which are all based on small deformation finite element analysis.

Ruptured submitral aneurysm

Directory of Open Access Journals (Sweden)

V. Shukla

2016-09-01

Full Text Available Submitral aneurysm is a rare entity, with around few hundred cases reported till date. Presentation can be varied. We describe here a case of submitral aneurysm in a young male with rupture into the left atrium cavity.

Study on pivot-point vibration of molecular bond-rupture events by quartz crystal microbalance for biomedical diagnostics

Directory of Open Access Journals (Sweden)

Yuan YJ

2012-01-01

Full Text Available Yong J Yuan, Renjie JiaLaboratory of Biosensing and MicroMechatronics, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan, People's Republic of ChinaAbstract: Bond-rupture scanning for biomedical diagnostics is examined using quartz crystal microbalance (QCM experiments and microparticle mechanics modeling calculations. Specific and nonspecific interactions between a microparticle and its binding QCM surface can be distinguished by gradually increasing the amplitude of driving voltage applied to QCM and monitoring its frequency changes. This research proposes a mechanical model of interactions between biological molecules and a QCM substrate surface. The mechanical force required to break a biotin–streptavidin bond was calculated through a one-pivot-point bottom-up vibration model. The bond-rupture force increases with an increase of the microparticle radius, the QCM resonant frequency, and the amplitude of driving voltage applied to the QCM. The significance of the research on biological molecular bond rupture is extremely important in characterizing microbial (such as cells and virus specificity, due to the force magnitude needed to break bonds using a transducer.Keywords: bond rupture, mechanical force, biomolecular binding energy spectra, quartz crystal microbalance (QCM

Traumatic rupture of the diaphragm: CT findings

International Nuclear Information System (INIS)

Cho, Sung Tae; Kim, Sung Jin; Cha, Sang Hoon; Park, Kil Sun; Kim, Jin Hee; Yim, Se Hwan

1995-01-01

The aim of this study was to assess the clinical utility of the known CT signs of the traumatic rupture of the diaphragm. CT scans and chest radiographs were retrospectively reviewed in 13 patients who had diaphragmatic rupture confirmed by surgery. On chest radiographs the elevation of the diaphragm was evaluated. On CT, 1) discontinuity of the diaphragm, 2) lack of depiction of the diaphragm surrounding the herniated intraabdominal organs (absent diaphragm sign), and 3) fat seen lateral to the diaphragm (fat sign) were evaluated. Chest radiographs showed the elevation of the diaphragm in 11 patients (85%). CT scan showed absent diaphragm sign in 11 patients (85%), discontinuity of the diaphragm in 8 (62%), and fat sign in 7 (54%). All of 12 patients who had the left diaphragmatic rupture had one or more of the above findings. Discontinuity of the diaphragm, absent diaphragm sign, and fat sign may be helpful CT findings in the diagnosis of the traumatic rupture of the left diaphragm

Traumatic Gallbladder Rupture Treated by Laparoscopic Cholecystectomy

Science.gov (United States)

Egawa, Noriyuki; Ueda, Junji; Hiraki, Masatsugu; Ide, Takao; Inoue, Satoshi; Sakamoto, Yuichiro; Noshiro, Hirokazu

2016-01-01

Abstract Gallbladder rupture due to blunt abdominal injury is rare. There are few reports of traumatic gallbladder injury, and it is commonly associated with other concomitant visceral injuries. Therefore, it is difficult to diagnose traumatic gallbladder rupture preoperatively when it is caused by blunt abdominal injury. We report a patient who underwent laparoscopic cholecystectomy after an exact preoperative diagnosis of traumatic gallbladder rupture. A 43-year-old man was admitted to our hospital due to blunt abdominal trauma. The day after admission, abdominal pain and ascites increased and a muscular defense sign appeared. Percutaneous drainage of the ascites was performed, and the aspirated fluid was bloody and almost pure bile. He was diagnosed with gallbladder rupture by the cholangiography using the endoscopic retrograde cholangiopancreatography technique. Laparoscopic cholecystectomy was performed safely, and he promptly recovered. If accumulated fluids contain bile, endoscopic cholangiography is useful not only to diagnose gallbladder injury but also to determine the therapeutic strategy. PMID:27462188

Traumatic Gallbladder Rupture Treated by Laparoscopic Cholecystectomy

Directory of Open Access Journals (Sweden)

Noriyuki Egawa

2016-05-01

Full Text Available Gallbladder rupture due to blunt abdominal injury is rare. There are few reports of traumatic gallbladder injury, and it is commonly associated with other concomitant visceral injuries. Therefore, it is difficult to diagnose traumatic gallbladder rupture preoperatively when it is caused by blunt abdominal injury. We report a patient who underwent laparoscopic cholecystectomy after an exact preoperative diagnosis of traumatic gallbladder rupture. A 43-year-old man was admitted to our hospital due to blunt abdominal trauma. The day after admission, abdominal pain and ascites increased and a muscular defense sign appeared. Percutaneous drainage of the ascites was performed, and the aspirated fluid was bloody and almost pure bile. He was diagnosed with gallbladder rupture by the cholangiography using the endoscopic retrograde cholangiopancreatography technique. Laparoscopic cholecystectomy was performed safely, and he promptly recovered. If accumulated fluids contain bile, endoscopic cholangiography is useful not only to diagnose gallbladder injury but also to determine the therapeutic strategy.

MRI in flexor tendon rupture after collagenase injection

International Nuclear Information System (INIS)

Khurana, Shruti; Wadhwa, Vibhor; Chhabra, Avneesh; Amirlak, Bardia

2017-01-01

Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture. (orig.)

MRI in flexor tendon rupture after collagenase injection

Energy Technology Data Exchange (ETDEWEB)

Khurana, Shruti [Lady Hardinge Medical College, New Delhi (India); Wadhwa, Vibhor [University of Arkansas for Medical Sciences, Little Rock, AR (United States); Chhabra, Avneesh [UT Southwestern Medical Center, Dallas, TX (United States); Johns Hopkins University, Baltimore, MD (United States); Amirlak, Bardia [UT Southwestern Medical Center, Dallas, TX (United States)

2017-02-15

Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture. (orig.)

Source rupture process of the 2016 Kaikoura, New Zealand earthquake estimated from the kinematic waveform inversion of strong-motion data

Science.gov (United States)

Zheng, Ao; Wang, Mingfeng; Yu, Xiangwei; Zhang, Wenbo

2018-03-01

On 2016 November 13, an Mw 7.8 earthquake occurred in the northeast of the South Island of New Zealand near Kaikoura. The earthquake caused severe damages and great impacts on local nature and society. Referring to the tectonic environment and defined active faults, the field investigation and geodetic evidence reveal that at least 12 fault sections ruptured in the earthquake, and the focal mechanism is one of the most complicated in historical earthquakes. On account of the complexity of the source rupture, we propose a multisegment fault model based on the distribution of surface ruptures and active tectonics. We derive the source rupture process of the earthquake using the kinematic waveform inversion method with the multisegment fault model from strong-motion data of 21 stations (0.05-0.35 Hz). The inversion result suggests the rupture initiates in the epicentral area near the Humps fault, and then propagates northeastward along several faults, until the offshore Needles fault. The Mw 7.8 event is a mixture of right-lateral strike and reverse slip, and the maximum slip is approximately 19 m. The synthetic waveforms reproduce the characteristics of the observed ones well. In addition, we synthesize the coseismic offsets distribution of the ruptured region from the slips of upper subfaults in the fault model, which is roughly consistent with the surface breaks observed in the field survey.

NRC concerns about steam generator tube U-bend failures

International Nuclear Information System (INIS)

Dillon, R.L.

1981-01-01

This paper concerns itself with genralized NRC regulatory policy regarding SGT failures and staff reports and opinions which may tend to influence the developing policy specific to U-bend failures. The most significant analysis at hand in predicting NRC policy on SGT U-bend failures is Marsh's Evaluation of Steam Generator Tube Rupture Events. Marsh sets out to describe and analyze the five steam generator tube ruptures that are known to NRC. All have occurred in the period 1975 to 1980

CT classification and clinical significance of rupture globe

International Nuclear Information System (INIS)

Diao Jinzhong; Zhang Guixiang

1998-01-01

Purpose: To discuss CT appearances of the rupture globe, and CT classifications and their clinical significance. Materials and methods: Forty-nine rupture globes were verified; 79% patents were scanned within 24 hours. Axial plane scanning were done with 3 mm slice and 256 x 256 matrix. Bone and soft tissue conditions were adjusted to analyse the bone and globe structures. Results: CT showed that globe circle rupture in one point of 32%, two points of 20%, and multiple points of 28%. Thickening of globe circle was as follows: 5 mm in 10 globes, 6 mm in 24, and 7 mm in 9.20% injured globes were enlarged and 32% were contracted. 14 anterior chambers deepened more than 4 mm. 83% rupture globes also had intraglobe hemorrhage and 48% foreign bodies. 28% injured globes had exophthalmus, and 75% had injured parasinuses or orbits, or brain trauma. Conclusion: The authors classified the rupture globe into three types. Type III showed unrepaired that should ablate the injured globes, whereas type I and II had to repair and to debride

Ruptured Massa Intermedia Secondary to Hydrocephalus.

Science.gov (United States)

El Damaty, Ahmed; Langner, Soenke; Schroeder, Henry W S

2017-01-01

We report a case of ruptured massa intermedia (MI) as a sequela of hydrocephalus. A single case report is presented describing the sequelae of tumor bed hematoma after a posterior fossa hemangioblastoma resection in which the patient bled 3 days after surgery, resulting in secondary hydrocephalus and subsequently dilatation of the third ventricle, which resulted in rupture of the MI. The patient was managed on emergency basis with an external ventricular drain then endoscopically with a third ventriculostomy and clot extraction. Absent MI is not uncommon in hydrocephalic patients, and it is assumed to be the result of rupture from acute dilatation of the third ventricle. Our case report proves this assumption and documents the presence and absence of the MI before and after developing hydrocephalus. Copyright © 2016 Elsevier Inc. All rights reserved.

A comparison of pre-dropout and temporary rupture sessions in psychotherapy.

Science.gov (United States)

Gülüm, I Volkan; Soygüt, Gonca; Safran, Jeremy D

2016-11-15

Although numerous studies have investigated the relationship between the therapeutic alliance and dropout, most have focused on the relationship between alliance quality and psychotherapy outcomes. To compare sessions with therapeutic alliance ruptures and two sessions prior to treatment dropout (pre-dropout) in terms of rupture subtypes, psychotherapists' behavior, attitudes, and session content. We implemented quantitative methods to select the sessions and qualitative methods to analyze them. We analyzed 16 temporary rupture sessions from 12 therapist-patient dyads and 16 pre-dropout sessions from 8 different therapist-patient dyads. The sessions originate from clinical psychology Master's or Doctoral students under supervision in either cognitive behavioral or schema therapy. Pre-dropout sessions were considered unrepaired rupture sessions while rupture sessions were subsequently repaired. Results revealed apparent differences and similarities between the session types in positive and negative psychotherapist behaviors, content intensity, and the type and frequency of ruptures. We explored three new rupture subtypes: attributing positive developments to other sources, indirect speech, and sarcastic hostility. A striking implication is that the frequency of positive and negative psychotherapist behaviors, ruptures, and session content is more likely to decrease in the pre-dropout sessions than in the temporary rupture sessions.

Non‑bleeding Spontaneous Rupture of Hepatocellular Carcinoma

African Journals Online (AJOL)

split easily when the vascular load increases from hypertension or minor trauma is another hypothesis for of HCC ruptures.[6]. Abdominal pain is the only independent factor relating to rupture of HCC.[7] Doppler ultrasound and computer tomography (CT) scan are useful to exclude of hemoperitoneum and evaluation.

Fault Branching and Long-Term Earthquake Rupture Scenario for Strike-Slip Earthquake

Science.gov (United States)

Klinger, Y.; CHOI, J. H.; Vallage, A.

2017-12-01

Careful examination of surface rupture for large continental strike-slip earthquakes reveals that for the majority of earthquakes, at least one major branch is involved in the rupture pattern. Often, branching might be either related to the location of the epicenter or located toward the end of the rupture, and possibly related to the stopping of the rupture. In this work, we examine large continental earthquakes that show significant branches at different scales and for which ground surface rupture has been mapped in great details. In each case, rupture conditions are described, including dynamic parameters, past earthquakes history, and regional stress orientation, to see if the dynamic stress field would a priori favor branching. In one case we show that rupture propagation and branching are directly impacted by preexisting geological structures. These structures serve as pathways for the rupture attempting to propagate out of its shear plane. At larger scale, we show that in some cases, rupturing a branch might be systematic, hampering possibilities for the development of a larger seismic rupture. Long-term geomorphology hints at the existence of a strong asperity in the zone where the rupture branched off the main fault. There, no evidence of throughgoing rupture could be seen along the main fault, while the branch is well connected to the main fault. This set of observations suggests that for specific configurations, some rupture scenarios involving systematic branching are more likely than others.

Does permanent extensional deformation in lower forearc slopes indicate shallow plate-boundary rupture?

Science.gov (United States)

Geersen, J.; Ranero, C. R.; Kopp, H.; Behrmann, J. H.; Lange, D.; Klaucke, I.; Barrientos, S.; Diaz-Naveas, J.; Barckhausen, U.; Reichert, C.

2018-05-01

Seismic rupture of the shallow plate-boundary can result in large tsunamis with tragic socio-economic consequences, as exemplified by the 2011 Tohoku-Oki earthquake. To better understand the processes involved in shallow earthquake rupture in seismic gaps (where megathrust earthquakes are expected), and investigate the tsunami hazard, it is important to assess whether the region experienced shallow earthquake rupture in the past. However, there are currently no established methods to elucidate whether a margin segment has repeatedly experienced shallow earthquake rupture, with the exception of mechanical studies on subducted fault-rocks. Here we combine new swath bathymetric data, unpublished seismic reflection images, and inter-seismic seismicity to evaluate if the pattern of permanent deformation in the marine forearc of the Northern Chile seismic gap allows inferences on past earthquake behavior. While the tectonic configuration of the middle and upper slope remains similar over hundreds of kilometers along the North Chilean margin, we document permanent extensional deformation of the lower slope localized to the region 20.8°S-22°S. Critical taper analyses, the comparison of permanent deformation to inter-seismic seismicity and plate-coupling models, as well as recent observations from other subduction-zones, including the area that ruptured during the 2011 Tohoku-Oki earthquake, suggest that the normal faults at the lower slope may have resulted from shallow, possibly near-trench breaking earthquake ruptures in the past. In the adjacent margin segments, the 1995 Antofagasta, 2007 Tocopilla, and 2014 Iquique earthquakes were limited to the middle and upper-slope and the terrestrial forearc, and so are upper-plate normal faults. Our findings suggest a seismo-tectonic segmentation of the North Chilean margin that seems to be stable over multiple earthquake cycles. If our interpretations are correct, they indicate a high tsunami hazard posed by the yet un-ruptured

Pancreatic Pseudocyst Ruptured due to Acute Intracystic Hemorrhage

Directory of Open Access Journals (Sweden)

Kunishige Okamura

2017-12-01

Full Text Available Rupture of pancreatic pseudocyst is one of the rare complications and usually results in high mortality. The present case was a rupture of pancreatic pseudocyst that could be treated by surgical intervention. A 74-year-old man developed abdominal pain, vomiting, and diarrhea, and he was diagnosed with cholecystitis and pneumonia. Three days later, acute pancreatitis occurred and computed tomography (CT showed slight hemorrhage in the cyst of the pancreatic tail. After another 10 days, CT showed pancreatic cyst ruptured due to intracystic hemorrhage. Endoscopic retrograde cholangiopancreatography revealed leakage of contrast agent from pancreatic tail cyst to enclosed abdominal cavity. His left hypochondrial pain was increasing, and CT showed rupture of the cyst of the pancreatic tail into the peritoneal cavity was increased in 10 days. CT showed also two left renal tumors. Therefore we performed distal pancreatectomy with concomitant resection of transverse colon and left kidney. We histopathologically diagnosed pancreatic pseudocyst ruptured due to intracystic hemorrhage and renal cell carcinoma. Despite postoperative paralytic ileus and fluid collection at pancreatic stump, they improved by conservative management and he could be discharged on postoperative day 29. He has achieved relapse-free survival for 6 months postoperatively. The mortality of pancreatic pseudocyst rupture is very high if some effective medical interventions cannot be performed. It should be necessary to plan appropriate treatment strategy depending on each patient.

Distance and Azimuthal Dependence of Ground‐Motion Variability for Unilateral Strike‐Slip Ruptures

KAUST Repository

Vyas, Jagdish Chandra

2016-06-21

We investigate near‐field ground‐motion variability by computing the seismic wavefield for five kinematic unilateral‐rupture models of the 1992 Mw 7.3 Landers earthquake, eight simplified unilateral‐rupture models based on the Landers event, and a large Mw 7.8 ShakeOut scenario. We include the geometrical fault complexity and consider different 1D velocity–density profiles for the Landers simulations and a 3D heterogeneous Earth structure for the ShakeOut scenario. For the Landers earthquake, the computed waveforms are validated using strong‐motion recordings. We analyze the simulated ground‐motion data set in terms of distance and azimuth dependence of peak ground velocity (PGV). Our simulations reveal that intraevent ground‐motion variability Graphic is higher in close distances to the fault (<20  km) and decreases with increasing distance following a power law. This finding is in stark contrast to constant sigma‐values used in empirical ground‐motion prediction equations. The physical explanation of a large near‐field Graphic is the presence of strong directivity and rupture complexity. High values of Graphic occur in the rupture‐propagation direction, but small values occur in the direction perpendicular to it. We observe that the power‐law decay of Graphic is primarily controlled by slip heterogeneity. In addition, Graphic, as function of azimuth, is sensitive to variations in both rupture speed and slip heterogeneity. The azimuth dependence of the ground‐motion mean μln(PGV) is well described by a Cauchy–Lorentz function that provides a novel empirical quantification to model the spatial dependency of ground motion. Online Material: Figures of slip distributions, residuals to ground‐motion prediction equations (GMPEs), distance and azimuthal dependence, and directivity predictor of ground‐motion variability for different source models.

Eccentric pressurized tube for measuring creep rupture

International Nuclear Information System (INIS)

Schwab, P.R.

1981-01-01

Creep rupture is a long term failure mode in structural materials that occurs at high temperatures and moderate stress levels. The deterioration of the material preceding rupture, termed creep damage, manifests itself in the formation of small cavities on grain boundaries. To measure creep damage, sometimes uniaxial tests are performed, sometimes density measurements are made, and sometimes the grain boundary cavities are measured by microscopy techniques. The purpose of the present research is to explore a new method of measuring creep rupture, which involves measuring the curvature of eccentric pressurized tubes. Theoretical investigations as well as the design, construction, and operation of an experimental apparatus are included in this research

Crystal plastic earthquakes in dolostones: from slow to fast ruptures.

Science.gov (United States)

Passelegue, F. X.; Aubry, J.; Nicolas, A.; Fondriest, M.; Schubnel, A.; Di Toro, G.

2017-12-01

Dolostone is the most dominant lithology of the seismogenic upper crust around the Mediterranean Sea. Understanding the internal mechanisms controlling fault friction is crucial for understanding seismicity along active faults. Displacement in such fault zones is frequently highlighted by highly reflective (mirror-like) slip surfaces, created by thin films of nanogranular fault rock. Using saw-cut dolostone samples coming from natural fault zones, we conducted stick-slip experiments under triaxial loading conditions at 30, 60 and 90 MPa confining pressure and temperature ranging from 30 to 100 degrees C. At 30 and 65 degrees C, only slow rupture was observed and the experimental fault exhibits frictional behaviour, i.e. a dependence of normal stress on peak shear stress. At 65 degrees C, a strengthening behaviour is observed after the main rupture, leading to a succession of slow rupture. At 100 degrees C, the macroscopic behaviour of the fault becomes ductile, and no dependence of pressure on the peak shear stress is observed. In addition, the increase of the confining pressure up to 60 and 90 MPa allow the transition from slow to fast rupture, highlighted by the records of acoustic activity and by dynamic stress drop occurring in a few tens of microseconds. Using strain gages located along the fault surface and acoustic transducers, we were able to measure the rupture velocities during slow and fast rupture. Slow ruptures propagated around 0.1 m/s, in agreement with natural observations. Fast ruptures propagated up to supershear velocities, i.e. faster than the shear wave speed (>3500 m/s). A complete study of the microstructures was realized before and after ruptures. Slow ruptures lead to the production of mirror-like surface driven by the production of nanograins due to dislocation processes. Fast ruptures induce the production of amorphous material along the fault surface, which may come from decarbonation and melting processes. We demonstrate that the

[Achilles tendon rupture].

Science.gov (United States)

Thermann, H; Hüfner, T; Tscherne, H

2000-03-01

The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques.

FlexibleSUSY-A spectrum generator generator for supersymmetric models

Science.gov (United States)

Athron, Peter; Park, Jae-hyeon; Stöckinger, Dominik; Voigt, Alexander

2015-05-01

We introduce FlexibleSUSY, a Mathematica and C++ package, which generates a fast, precise C++ spectrum generator for any SUSY model specified by the user. The generated code is designed with both speed and modularity in mind, making it easy to adapt and extend with new features. The model is specified by supplying the superpotential, gauge structure and particle content in a SARAH model file; specific boundary conditions e.g. at the GUT, weak or intermediate scales are defined in a separate FlexibleSUSY model file. From these model files, FlexibleSUSY generates C++ code for self-energies, tadpole corrections, renormalization group equations (RGEs) and electroweak symmetry breaking (EWSB) conditions and combines them with numerical routines for solving the RGEs and EWSB conditions simultaneously. The resulting spectrum generator is then able to solve for the spectrum of the model, including loop-corrected pole masses, consistent with user specified boundary conditions. The modular structure of the generated code allows for individual components to be replaced with an alternative if available. FlexibleSUSY has been carefully designed to grow as alternative solvers and calculators are added. Predefined models include the MSSM, NMSSM, E6SSM, USSM, R-symmetric models and models with right-handed neutrinos.

Long-term outcomes of percutaneous lumbar facet synovial cyst rupture

Energy Technology Data Exchange (ETDEWEB)

Huang, Ambrose J.; Bos, Stijn A.; Torriani, Martin; Simeone, F.J.; Chang, Connie Y.; Pomerantz, Stuart R.; Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States)

2017-01-15

To evaluate the therapeutic value, safety, and long-term clinical outcomes of percutaneous lumbar facet synovial cyst (LFSC) rupture. Our study was institutional review board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant. The study group comprised 71 patients (44 women, mean age: 65 ± 17 years) who underwent CT- or fluoroscopy-guided percutaneous LFSC rupture. The technical success of LFSC rupture, the long-term clinical outcome, including repeat procedures or surgery, and imaging findings on MRI and CT were recorded. Seventy-nine LFSC ruptures were performed in 71 patients. CT guidance was used in 57 cases and fluoroscopy guidance in 22 cases. LFSC rupture was technically successful in 58 out of 79 cases (73 %). Mean injection volume for cyst rupture was 3.6 ± 2.2 mL and a combination of steroid and anesthetic was injected in all cases. Over a mean follow-up time of 44 months, 12 % of patients underwent repeat cyst rupture, and 46 % eventually underwent surgery, whereas the majority of patients (55 %) experienced symptomatic relief and did not undergo surgery. There was no significant association between a successful outcome and age, sex, level, or size of LFSC (p > 0.1). LFSCs with T2 hypointensity were more likely to require surgery (p = 0.02). There was one complication, a bacterial skin infection that completely resolved following antibiotic therapy. Percutaneous LFSC rupture is an effective and safe nonsurgical treatment option for LFSC. More than half of treated patients were able to avoid subsequent surgery. Therefore, percutaneous LFSC rupture should be considered before surgical intervention. (orig.)