Science.gov

Sample records for transverse rupture strength

  1. Strength of transversely isotropic rocks

    E-print Network

    Pei, Jianyong, 1975-

    2008-01-01

    This thesis proposes a new Anisotropic Matsuoka-Nakai (AMN) criterion to characterize the failure of transversely isotropic rocks under true triaxial stress states. One major obstacle in formulating an anisotropic criterion ...

  2. Stress-rupture strength and microstructural stability of W-HF-C wire reinforced superalloy composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Signorelli, R. A.

    1974-01-01

    W-Hf-C/superalloy composites were found to be potentially useful for turbine blade applications on the basis of stress-rupture strength. The 100-and 1000-hour rupture strengths obtained for 70 volume percent fiber composites tested at 1090 C were 420 and 280 MN/sq m (61,000 and 41,000 psi). The investigation indicated that with better quality fibers, composites having 100- and 1000-hour rupture strengths of 570 and 370 MN/sq m (82,000 and 54,000 psi) may be obtained. Metallographic studies indicated sufficient fiber-matrix compatibility for long time applications at 1090 C for 1000 hours or more.

  3. Characterisation of Laves phase precipitation and its correlation to creep rupture strength of ferritic steels

    SciTech Connect

    Zhu, S.; Yang, M.; Song, X.L.; Tang, S.; Xiang, Z.D.

    2014-12-15

    The Laves phase precipitation process was characterised by means of field emission scanning electron microscopy to demonstrate its effect on creep rupture strength of steels with a fully ferritic matrix. To eliminate the effects of carbide and carbonitride precipitations so that the creep rupture data can be analysed exclusively in relation to the Laves phase precipitation process, an alloy Fe–9Cr–3Co–3W (wt.%) without C and N additions was used for the study. Creep rupture strengths were measured and volume fraction and particle size of Laves phase precipitates in the ruptured specimens were analysed. It was found that the creep rupture strength started to collapse (or decrease more rapidly) long before the Laves phase precipitation reached equilibrium fraction. This was related to the onset of the coarsening of Laves phase particles, which precipitated only on grain boundaries and hence contributed little to precipitation strengthening. Creep deformation had no effect either on the precipitation kinetics or on the growth kinetics of Laves phase particles. - Highlights: • Laves phase precipitation at 650 °C was characterised for Fe–9Cr–3W–3Co alloy. • Laves phase precipitated predominantly on grain boundaries. • Creep deformation had no effect on Laves phase precipitation and growth kinetics. • Creep strength started to collapse long before Laves phase precipitation is ended. • Collapse of creep strength was attributed to the coarsening of Laves phase particles.

  4. Creep rupture strength of activated-TIG welded 316L(N) stainless steel

    NASA Astrophysics Data System (ADS)

    Sakthivel, T.; Vasudevan, M.; Laha, K.; Parameswaran, P.; Chandravathi, K. S.; Mathew, M. D.; Bhaduri, A. K.

    2011-06-01

    316L(N) stainless steel plates were joined using activated-tungsten inert gas (A-TIG) welding and conventional TIG welding process. Creep rupture behavior of 316L(N) base metal, and weld joints made by A-TIG and conventional TIG welding process were investigated at 923 K over a stress range of 160-280 MPa. Creep test results showed that the enhancement in creep rupture strength of weld joint fabricated by A-TIG welding process over conventional TIG welding process. Both the weld joints fractured in the weld metal. Microstructural observation showed lower ?-ferrite content, alignment of columnar grain with ?-ferrite along applied stress direction and less strength disparity between columnar and equiaxed grains of weld metal in A-TIG joint than in MP-TIG joint. These had been attributed to initiate less creep cavitation in weld metal of A-TIG joint leading to improvement in creep rupture strength.

  5. Stress-rupture strength and microstructural stability of tungsten-hafnium-carbon-wire reinforced superalloy composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.; Signorelli, R. A.

    1974-01-01

    Tungsten-hafnium-carbon - superalloy composites were found to be potentially useful for turbine blade applications on the basis of stress-rupture strength. The 100- and 1000-hr rupture strengths calculated for 70 vol. % fiber composites based on test data at 1090C (2000F) were 420 and 280 MN/m2 (61,000 and 41,000 psi, respectively). The investigation indicated that, with better quality fibers, composites having 100- and 1000-hr rupture strengths of 570 and 370 MN/m2 (82,000 and 54,000 psi, respectively), may be obtained. Metallographic studies indicated sufficient fiber-matrix compatibility for 1000 hr or more at 1090C (2000F).

  6. Rupture Strength of Several Nickel-base Alloys in Sheet Form

    NASA Technical Reports Server (NTRS)

    Dance, James H; Clauss, Francis J

    1957-01-01

    The 100-hour rupture strengths of Inconel X, Inconel 700, Incoloy 901, Refractaloy 26, and R-235 at 1200 and 1350 F. in both the annealed and heat-treated conditions were determined. Inconel 700 had the highest rupture strength at both temperatures; Incoloy 901 was second strongest at 1200 F, and R-235 second strongest at 1350 F. With the exception of Incoloy 901, ductility was low. Photomicrographs show that fractures are through the grain boundaries. Results are compared with published data for other sheet alloys and bar stock.

  7. Comparison of the Tensile, Creep, and Rupture Strength Properties of Stoichiometric SiC Fibers

    NASA Technical Reports Server (NTRS)

    Yun, H. M.; DiCarlo, J. A.

    1999-01-01

    Tensile strength, creep strength, and rupture strength properties were measured for the following types of polymer-derived stoichiometric SiC fibers: Hi-Nicalon Type S from Nippon Carbon, Tyranno SA from Ube, and Sylramic from Dow Corning. Also included in this study were an earlier version of the SA fiber plus two recent developmental versions of the Sylramic fiber. The tensile strength measurements were made at room temperature on as-received fibers and on fibers after high-temperature inert exposure. The creep-rupture property data were obtained at 1400 deg C in air as well as, argon. Some fiber types showed strong effects of environment on their strength properties. These results are compared and discussed in terms of underlying mechanisms and implications for ceramic composites.

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

    NASA Technical Reports Server (NTRS)

    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.

  9. Composite Stress Rupture: A New Reliability Model Based on Strength Decay

    NASA Technical Reports Server (NTRS)

    Reeder, James R.

    2012-01-01

    A model is proposed to estimate reliability for stress rupture of composite overwrap pressure vessels (COPVs) and similar composite structures. This new reliability model is generated by assuming a strength degradation (or decay) over time. The model suggests that most of the strength decay occurs late in life. The strength decay model will be shown to predict a response similar to that predicted by a traditional reliability model for stress rupture based on tests at a single stress level. In addition, the model predicts that even though there is strength decay due to proof loading, a significant overall increase in reliability is gained by eliminating any weak vessels, which would fail early. The model predicts that there should be significant periods of safe life following proof loading, because time is required for the strength to decay from the proof stress level to the subsequent loading level. Suggestions for testing the strength decay reliability model have been made. If the strength decay reliability model predictions are shown through testing to be accurate, COPVs may be designed to carry a higher level of stress than is currently allowed, which will enable the production of lighter structures

  10. Influence of Specimen Preparation and Specimen Size on Composite Transverse Tensile Strength and Scatter

    NASA Technical Reports Server (NTRS)

    OBrien, T. Kevin; Chawan, Arun D.; DeMarco, Kevin; Paris, Isabelle

    2001-01-01

    The influence of specimen polishing, configuration, and size on the transverse tension strength of two glass-epoxy materials, and one carbon-epoxy material, loaded in three and four point bending was evaluated. Polishing machined edges, arid/or tension side failure surfaces, was detrimental to specimen strength characterization instead of yielding a higher, more accurate, strength as a result of removing inherent manufacture and handling flaws. Transverse tension strength was typically lower for longer span lengths due to the classical weakest link effect. However, strength was less sensitive to volume changes achieved by increasing specimen width. The Weibull scaling law typically over-predicted changes in transverse tension strengths in three point bend tests and under-predicted changes in transverse tension strengths in four point bend tests. Furthermore, the Weibull slope varied with specimen configuration, volume, and sample size. Hence, this scaling law was not adequate for predicting transverse tension strength of heterogeneous, fiber-reinforced, polymer matrix composites.

  11. Influence of Specimen Preparation and Specimen Size on the Transverse Tensile Strength and Scatter of Glass Epoxy Laminates

    NASA Technical Reports Server (NTRS)

    OBrien, T. Kevin; Chawan, Arun D.; DeMarco, Kevin

    1999-01-01

    The influence of specimen polishing, specimen configuration, and specimen size on the transverse tension strength of two glass epoxy materials loaded in three and four point bending was evaluated. Polishing machined edges, and/or tension side failure surfaces, was detrimental to specimen strength characterization instead of yielding a higher, more accurate, strength as a result of removing inherent manufacture and handling flaws. Transverse tension strength was sensitive to span length due to the classical weakest link effect. However, strength was less sensitive to volume changes achieved by increasing specimen width. The Weibull scaling law over-predicted changes in transverse tension strengths in three point bend tests and under-predicted changes in transverse tension strengths in four point bend tests. Furthermore, the Weibull slope varied with specimen configuration, volume, and sample size. Hence, the utility of this scaling law for predicting transverse tension strength is unclear.

  12. Scale effects on the transverse tensile strength of graphite epoxy composites

    NASA Technical Reports Server (NTRS)

    Obrien, T. Kevin; Salpekar, Satish A.

    1992-01-01

    The influence of material volume on the transverse tensile strength of AS4/3501-6 graphite epoxy composites was investigated. Tensile tests of 90 degree laminates with 3 different widths and 5 different thicknesses were conducted. A finite element analysis was performed to determine the influence of the grip on the stress distribution in the coupons and explain the tendency for the distribution of failure locations to be skewed toward the grip. Specimens were instrumented with strain gages and extensometers to insure good alignment and to measure failure strains. Data indicated that matrix dominated strength properties varied with the volume of material that was stressed, with the strength decreasing as volume increased. Transverse strength data were used in a volumetric scaling law based on Weibull statistics to predict the strength of 90 degree laminates loaded in three point bending. Comparisons were also made between transverse strength measurements and out-of-plane interlaminar tensile strength measurements from curved beam bending tests. The significance of observed scale effects on the use of tests for material screening, quality assurance, and design allowables is discussed.

  13. Effect of low transverse magnetic field on the confinement strength in a quasi-1D wire

    SciTech Connect

    Kumar, Sanjeev; Thomas, K. J.; Smith, L. W.; Farrer, I.; Ritchie, D. A.; Jones, G. A. C.; Griffiths, J.; Pepper, M.

    2013-12-04

    Transport measurements in a quasi-one dimensional (1D) quantum wire are reported in the presence of low transverse magnetic field. Differential conductance shows weak quantised plateaus when the 2D electrons are squeezed electrostatically. Application of a small transverse magnetic field (0.2T) enhances the overall degree of quantisation due to the formation of magneto-electric subbands. The results show the role of magnetic field to fine tune the confinement strength in low density wires when interaction gives rise to double row formation.

  14. In vitro comparison of autoclave polymerization on the transverse strength of denture base resins.

    PubMed

    Durkan, Rukiye; Ozel, Mehmet Birol; Ba?i?, Bora; Usanmaz, Ali

    2008-07-01

    The aim of this study was to determine the effect of autoclave polymerization on the transverse strength of denture base polymers. To this end, 30 rectangular test specimens were fabricated of two heat-polymerized denture base polymers. The test groups were: (I) control, i.e., conventional water bath to polymerize resins by heat at 100 degrees C for 30 minutes; (II) autoclave polymerization at 60 degrees C for 30 minutes followed by 130 degrees C for 10 minutes; and (III) autoclave polymerization at 60 degrees C for 30 minutes followed by 130 degrees C for 20 minutes. The specimens were tested with three-point bending test at a crosshead speed of 5 mm/min. It was revealed that the transverse strength of specimens increased with statistical significance when the autoclave was used for polymerization. PMID:18833780

  15. Effects of Heterogeneities in Strength and Initial Shear Stress on Large Ruptures in a Fast Multi-cycle Earthquake Simulator (RSQSim) and DYNA3D

    NASA Astrophysics Data System (ADS)

    Stevens, J.; Richards-Dinger, K.; Dieterich, J.; Oglesby, D.

    2008-12-01

    RSQSim is a fast earthquake simulator that produces long (~ 106 event and ~ 104 year) synthetic seismicity catalogs in complex fault systems. It treats the interseismic and nucleation phases of the seismic cycle quasi-statically with an approximate version of rate- and state-dependent friction. The ruptures themselves are quasi-dynamic with slip speeds determined by shear impedance considerations. Validation of coseismic final slip (and therefore stress change) distributions is important for the generation of long catalogs because subsequent events in such simulators need to inherit the proper stress fields. Also, the heterogeneous evolved stress states from long simulations in complex fault systems (resulting from complex large ruptures, ongoing smaller seismicity, and stress interactions within the fault system) may be useful as more realistic inputs to dynamic rupture modelling. If the time evolution of ruptures in RSQSim is also realistic, they may be useful as kinematic sources for seismic hazard ground motion calculations. As part of an effort to validate the quasi-dynamic ruptures in RSQSim, we compare rupture propagation on a variable-strength planar fault in RSQSim to that on a similar fault in DYNA3D (a fully dynamic finite element model employing slip-weakening friction) for single, large, artificially nucleated ruptures. Previous work has shown that on homogeneous planar faults the RSQSim results agreed quantitatively very well with those of DYNA3D. For this comparison, our asperity model consists of multiple rectangular zones of increased normal stress of varying size, location, and amplitude. The heterogeneities produce complex ruptures - the rupture front tends to wrap itself around the barriers and create a burst of energy once it propagates across a barrier. Both codes allow rupture propagation over significant zones of negative stress drop in these asperity regions. Rupture durations, average rupture propagation speeds, and overall slip pattern are quite similar with both methods. However, ruptures in DYNA3D propagate more rapidly through the barriers and generate less high-frequency variations of slip than ruptures in RSQSim. The qualitative agreement of these two very different methods is good and may improve with further tuning of quasi-dynamic computational parameters. Using the same heterogeneous strength distribution as in the single-event examples, we use RSQSim to simulate several thousand years of additional seismicity. The effects of the asperities along the fault become much more subtle over multiple earthquake cycles as the shear stress adjusts to the higher normal stress in the asperities. Subsequent large spontaneous events rupture at much more variable and significantly slower velocities through the evolved stress states than through the uniform initial shear stress state of the first, artificially nucleated event. Indeed, the ruptures occasionally nearly come to a halt before continuing. These complex ruptures will produce very different ground motions than the more coherent ruptures seen in ruptures through smoother initial stress states.

  16. Analysis of Ninety Degree Flexure Tests for Characterization of Composite Transverse Tensile Strength

    NASA Technical Reports Server (NTRS)

    OBrien, T. Kevin; Krueger, Ronald

    2001-01-01

    Finite element (FE) analysis was performed on 3-point and 4-point bending test configurations of ninety degree oriented glass-epoxy and graphite-epoxy composite beams to identify deviations from beam theory predictions. Both linear and geometric non-linear analyses were performed using the ABAQUS finite element code. The 3-point and 4-point bending specimens were first modeled with two-dimensional elements. Three-dimensional finite element models were then performed for selected 4-point bending configurations to study the stress distribution across the width of the specimens and compare the results to the stresses computed from two-dimensional plane strain and plane stress analyses and the stresses from beam theory. Stresses for all configurations were analyzed at load levels corresponding to the measured transverse tensile strength of the material.

  17. High-frequency spectral falloff of earthquakes, fractal dimension of complex rupture, b value, and the scaling of strength on faults

    USGS Publications Warehouse

    Frankel, A.

    1991-01-01

    The high-frequency falloff ??-y of earthquake displacement spectra and the b value of aftershock sequences are attributed to the character of spatially varying strength along fault zones. I assume that the high frequency energy of a main shock is produced by a self-similar distribution of subevents, where the number of subevents with radii greater than R is proportional to R-D, D being the fractal dimension. In the model, an earthquake is composed of a hierarchical set of smaller earthquakes. The static stress drop is parameterized to be proportional to R??, and strength is assumed to be proportional to static stress drop. I find that a distribution of subevents with D = 2 and stress drop independent of seismic moment (?? = 0) produces a main shock with an ??-2 falloff, if the subevent areas fill the rupture area of the main shock. By equating subevents to "islands' of high stress of a random, self-similar stress field on a fault, I relate D to the scaling of strength on a fault, such that D = 2 - ??. Thus D = 2 corresponds to constant stress drop scaling (?? = 0) and scale-invariant fault strength. A self-similar model of aftershock rupture zones on a fault is used to determine the relationship between the b value, the size distribution of aftershock rupture zones, and the scaling of strength on a fault. -from Author

  18. Glass rupture disk

    DOEpatents

    Glass, S. Jill (Albuquerque, NM); Nicolaysen, Scott D. (Albuquerque, NM); Beauchamp, Edwin K. (Albuquerque, NM)

    2002-01-01

    A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

  19. Method of Estimating the Long-term Rupture Strength of 11Cr-2W-0.4Mo-1Cu-Nb-V Steel

    NASA Astrophysics Data System (ADS)

    Tamura, Manabu

    2015-05-01

    Long-term rupture data of 11Cr-2W-0.4Mo-1Cu-Nb-V steel were analyzed using an exponential equation for stress regarding time to rupture as a thermal activation process. The fitness was compared with the usually employed method assuming power-law creep. In the exponential method, rupture data are classified into several groups according to the thermal activation process; the activation energy, Q; the activation volume, V; then, the Larson-Miller constant, C, values are calculated, and a regression equation is obtained for each data group. The fitness level of the equation was satisfactorily high for each group. The values of Q, V, and C were unusually small for a data group where an unexpected drop in rupture strength was observed. The critical issue is how to comprehend signs of degradation within the short term. We can observe several signs at a creep time of approximately one-tenth of the times of the degradation events. The small values of Q and V indicate that completely softened regions form and creep locally, which is consistent with previous observations. From both metallurgical considerations and the variations of Q and V, it is suggested that the rate of the unexpected drop in strength is mitigated after further long-term creep.

  20. The effect of woven, chopped and longitudinal glass fibers reinforcement on the transverse strength of a repair resin.

    PubMed

    Uzun, G; Keyf, F

    2001-04-01

    Fracture resistance of prosthesis is an important clinical concern. This property is directly related to transverse strength. Strengthening of prostheses may result from reinforcement with various fiber types. This study evaluated the effect of fiber type on the transverse strength of a commercially available autopolymerizing resin that is used for repairing prosthesis. The resin was reinforced with woven form, chopped form and longitudinal form, and no reinforcement was used. Uniform samples were made from autopolymerizing resin. In total, twenty-four bar-shaped specimens (60 x 10 x 4 mm) were reinforced with glass fibers. Nine specimens were prepared without fiber. A three-point loading test was used to measure transverse strength, maximal deflection, and modulus of elasticity. The Kruskal-Wallis analysis of variance was used to examine differences between the four groups. Although the results of the analysis between these groups showed no statistical significances, the transverse strength, maximal deflection and modulus of elasticity increased more with fiber than without the fiber group. This finding may be of clinical significance. Because the addition of fiber reinforcement enhanced the physical properties of the processed material, specially woven form glass fiber was superior to the other forms. PMID:11336388

  1. The effects of glass fiber reinforcement at different concentrations on the transverse strength, deflection and modulus of elasticity of a provisional fixed partial denture resin.

    PubMed

    Keyf, F; Uzun, G

    2001-10-01

    This study focused on some mechanical properties such as the transverse strength, maximal deflection and modulus of elasticity of a resin reinforced with untreated, chopped form glass fibers at different concentrations. A Teflon mould was used to prepare four groups of specimens. The specimens were prepared with different concentrations of the glass fiber to the mass of the powder/liquid mix (0.5, 1, 1.5%), and a mix without fiber was used as the control group. All the specimens were subjected to transverse testing with a cross-head speed of 5 mm/min. The load to fracture for each specimen with the maximum deflection at the point of loading in a three-point load test was recorded. The transverse strength of 0.5% fiber concentration was 54.45 MPa. The lowest value was 49.67 MPa for the 1% fiber concentration. The highest mean strength was for the specimens reinforced with 0.5% glass fiber. This mean was higher than for the mean of the control "without fiber" specimens. The specimens demonstrated an insignificant decrease in the transverse strength and the maximum deflection when the fiber concentration was increased. The inclusion of 1% glass fiber reduced the transverse strength, although the result was not statistically significant. PMID:11794724

  2. Numerical analysis of stress distribution in Cu-stabilized GdBCO CC tapes during anvil tests for the evaluation of transverse delamination strength

    NASA Astrophysics Data System (ADS)

    Dizon, John Ryan C.; Gorospe, Alking B.; Shin, Hyung-Seop

    2014-05-01

    Rare-earth-Ba-Cu-O (REBCO) based coated conductors (CCs) are now being used for electric device applications. For coil-based applications such as motors, generators and magnets, the CC tape needs to have robust mechanical strength along both the longitudinal and transverse directions. The CC tape in these coils is subjected to transverse tensile stresses during cool-down and operation, which results in delamination within and between constituent layers. In this study, in order to explain the behaviour observed in the evaluation of c-axis delamination strength in Cu-stabilized GdBCO CC tapes by anvil tests, numerical analysis of the mechanical stress distribution within the CC tape has been performed. The upper anvil size was varied in the analysis to understand the effect of anvil size on stress distribution within the multilayered CC tape, which is closely related to the delamination strength, delamination mode and delamination sites that were experimentally observed. The numerical simulation results showed that, when an anvil size covering the whole tape width was used, the REBCO coating film was subjected to the largest stress, which could result in low mechanical delamination and electromechanical delamination strengths. Meanwhile, when smaller-sized anvils were used, the copper stabilizer layer would experience the largest stress among all the constituent layers of the CC tape, which could result in higher mechanical and electromechanical delamination strengths, as well as high scattering of both of these delamination strengths. As a whole, the numerical simulation results could explain the damage evolution observed in CC tapes tested under transverse tensile stress, as well as the transverse tensile stress response of the critical current, Ic.

  3. In-vitro Evaluation of Transverse Strength of Repaired Heat Cured Denture Base Resins without Surface Treatment and with Chemical and Mechanical Surface Treatment

    PubMed Central

    Yadav, Naveen S; Khare, Shilpi; Mishra, Sunil Kumar; Vyas, Rajesh; Mahajan, Harsh; Chitumalla, Rajkiran

    2015-01-01

    Background: Denture repair involves joining two parts of a fractured denture with a denture repair material. Hence, a substantial repairing system for denture base fracture should be there to elude frequent fracture. Materials and Methods: Surface treatment of conventional heat cure denture base resin with different surface treatments (chemical ethyl acetate, and mechanical roughening with bur), with control group formed without surface treatment. Specimens were repaired with auto polymerizing acrylic resin using sprinkle on technique. The testing of the transverse strength of the repaired specimens was evaluated with three-point bending test on universal testing machine. Results: The study revealed that surface chemical treatment with ethyl acetate improved the transverse strength of repaired heat cure denture base when compared with mechanical and control group. A two-way analysis of variance revealed that there was statistically significant difference in mean strengths of the three groups. Conclusion: Surface chemical treatment with ethyl acetate improved the transverse strength of the repaired heat cure denture base when compared with mechanical roughening with bur and group without surface treatment. PMID:26464547

  4. Stress field associated with the rupture of the 1992 Landers, California, earthquake and its implications concerning the fault strength at the onset of the earthquake

    NASA Astrophysics Data System (ADS)

    Bouchon, Michel; Campillo, Michel; Cotton, Fabrice

    1998-09-01

    We investigate the space and time history of the shear stress produced on the fault during the 1992 Landers earthquake. The stress is directly calculated from the tomographic image of slip on the fault derived from near-source strong motion data. The results obtained shed some light on why the earthquake rupture cascaded along a series of previously distinct fault segments to produce the largest earthquake in California in over 40 years. Rupture on the 30 km long northernmost segment of the fault was triggered by a large dynamic increase of the stress field, of the order of 20 to 30 MPa, produced by the rupturing of the adjacent fault segments. Such a large increase was necessary to overcome the static friction on this strand of the fault, unfavorably oriented in today's tectonic stress field. This misorientation eventually led to the arrest of rupture. The same mechanism explains why rupture broke only a small portion of the Johnson Valley fault on which the earthquake originally started, before jumping to an adjacent fault more favorably oriented. We conclude from these results that the dynamic stress field could not sustain and drive the rupture along the strongly misoriented NW-SE strands of the preexisting fault system. Instead, the dynamic stress field produced new fractures favorably oriented in a N-S direction and connecting parts of the old fault system.

  5. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    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…

  6. Intramuscular triceps rupture.

    PubMed

    O'Driscoll, S W

    1992-04-01

    A 25-year-old man who had a complete intramuscular rupture of the long head of the triceps was treated nonoperatively and followed up prospectively for 10 years. The injury occurred after 4 days of white-water kayaking without any direct blow. Strengthening was performed by doing push-ups. Nine years of isokinetic testing revealed that isometric strength was normal, but endurance testing was reduced by 5% to 10%. Ruptures of the muscle belly can occur due to direct trauma or by forced elbow flexion during triceps contraction. From this and the few case reports available it appears that nonoperative treatment is effective and recommended for patients who do not require significant endurance strength in elbow extension. Whether or not the results can be improved by surgical repair is uncertain. PMID:1562935

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

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    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. PMID:26631334

  8. Monte Carlo characterization of skin doses in 6 MV transverse field MRI-linac systems: Effect of field size, surface orientation, magnetic field strength, and exit bolus

    SciTech Connect

    Oborn, B. M.; Metcalfe, P. E.; Butson, M. J.; Rosenfeld, A. B.

    2010-10-15

    Purpose: The main focus of this work is to continue investigations into the Monte Carlo predicted skin doses seen in MRI-guided radiotherapy. In particular, the authors aim to characterize the 70 {mu}m skin doses over a larger range of magnetic field strength and x-ray field size than in the current literature. The effect of surface orientation on both the entry and exit sides is also studied. Finally, the use of exit bolus is also investigated for minimizing the negative effects of the electron return effect (ERE) on the exit skin dose. Methods: High resolution GEANT4 Monte Carlo simulations of a water phantom exposed to a 6 MV x-ray beam (Varian 2100C) have been performed. Transverse magnetic fields of strengths between 0 and 3 T have been applied to a 30x30x20 cm{sup 3} phantom. This phantom is also altered to have variable entry and exit surfaces with respect to the beam central axis and they range from -75 deg. to +75 deg. The exit bolus simulated is a 1 cm thick (water equivalent) slab located on the beam exit side. Results: On the entry side, significant skin doses at the beam central axis are reported for large positive surface angles and strong magnetic fields. However, over the entry surface angle range of -30 deg. to -60 deg., the entry skin dose is comparable to or less than the zero magnetic field skin dose, regardless of magnetic field strength and field size. On the exit side, moderate to high central axis skin dose increases are expected except at large positive surface angles. For exit bolus of 1 cm thickness, the central axis exit skin dose becomes an almost consistent value regardless of magnetic field strength or exit surface angle. This is due to the almost complete absorption of the ERE electrons by the bolus. Conclusions: There is an ideal entry angle range of -30 deg. to -60 deg. where entry skin dose is comparable to or less than the zero magnetic field skin dose. Other than this, the entry skin dose increases are significant, especially at higher magnetic fields. On the exit side there is mostly moderate to high skin dose increases for 0.2-3 T with the only exception being large positive angles. Exit bolus of 1 cm thickness will have a significant impact on lowering such exit skin dose increases that occur as a result of the ERE.

  9. Supersonic Rupture of Rubber

    E-print Network

    M Marder

    2005-04-24

    The rupture of rubber differs from conventional fracture. It is supersonic, and the speed is determined by strain levels ahead of the tip rather than total strain energy as for ordinary cracks. Dissipation plays a very important role in allowing the propagation of ruptures, and the back edges of ruptures must toughen as they contract, or the rupture is unstable. This article presents several levels of theoretical description of this phenomenon: first, a numerical procedure capable of incorporating large extensions, dynamics, and bond rupture; second, a simple continuum model that can be solved analytically, and which reproduces several features of elementary shock physics; and third, an analytically solvable discrete model that accurately reproduces numerical and experimental results, and explains the scaling laws that underly this new failure mode. Predictions for rupture speed compare well with experiment.

  10. Ruptured intracranial dermoid cyst

    PubMed Central

    Barnett, David W.; Snipes, George J.; Layton, Kennith F.; Opatowsky, Michael J.

    2012-01-01

    Rupture of an intracranial dermoid cyst is a rare event with considerable associated morbidity and potential mortality. We present a case of intracranial rupture of a dermoid cystic tumor with consequent dissemination of subarachnoid fat droplets resulting in acute aseptic chemical meningitis. Radiographic findings, operative treatment, and pathologic features are described. PMID:22275778

  11. Surgical Treatment of Distal Biceps Ruptures.

    PubMed

    Stoll, Laura E; Huang, Jerry I

    2016-01-01

    Distal biceps ruptures occur from eccentric loading of a flexed elbow. Patients treated nonoperatively have substantial loss of strength in elbow flexion and forearm supination. Surgical approaches include 1-incision and 2-incision techniques. Advances in surgical technology have facilitated the popularity of single-incision techniques through a small anterior incision. Recently, there is increased focus on the detailed anatomy of the distal biceps insertion and the importance of anatomic repair in restoring forearm supination strength. Excellent outcomes are expected with early repair of the distal biceps, with restoration of strength and endurance to near-normal levels with minimal to no loss of motion. PMID:26614933

  12. Triple cardiac rupture.

    PubMed

    Vazquez, Alejandro; Osa, Ana; Vicente, Rosario; Montero, Jose A

    2014-09-01

    Left ventricular free wall rupture and acute ischaemic mitral regurgitation are nowadays rare, but still potentially lethal mechanical complications after acute myocardial infarction. We report a case of a sequential left ventricular free wall rupture, anterolateral papillary muscle disruption, secondary severe mitral regurgitation and subsequent posteromedial papillary muscle head rupture in a single patient during the same ischaemic episode after myocardial infarction, and their related successful surgical procedures and management until discharge. Prompt bedside diagnosis and emergent consecutive surgical procedures, as well as temporary left ventricular assistance, were crucial in the survival of this patient. PMID:24876216

  13. Ruptured visceral artery aneurysms.

    PubMed

    Chiaradia, M; Novelli, L; Deux, J-F; Tacher, V; Mayer, J; You, K; Djabbari, M; Luciani, A; Rahmouni, A; Kobeiter, H

    2015-01-01

    Visceral artery aneurysms are rare but their estimated mortality due to rupture ranges between 25 and 70%. Treatment of visceral artery aneurysm rupture is usually managed by interventional radiology. Specific embolization techniques depend on the location, affected organ, locoregional arterial anatomy, and interventional radiologist skill. The success rate following treatment by interventional radiology is greater than 90%. The main complication is recanalization of the aneurysm, showing the importance of post-therapeutic monitoring, which should preferably be performed using MR imaging. PMID:26054246

  14. Creep rupture behavior of Stirling engine materials

    NASA Technical Reports Server (NTRS)

    Titran, R. H.; Scheuerman, C. M.; Stephens, J. R.

    1985-01-01

    The automotive Stirling engine, being investigated jointly by the Department of Energy and NASA Lewis as an alternate to the internal combustion engine, uses high-pressure hydrogen as the working fluid. The long-term effects of hydrogen on the high temperature strength properties of materials is relatively unknown. This is especially true for the newly developed low-cost iron base alloy NASAUT 4G-A1. This iron-base alloy when tested in air has creep-rupture strengths in the directionally solidified condition comparable to the cobalt base alloy HS-31. The equiaxed (investment cast) NASAUT 4G-A1 has superior creep-rupture to the equiaxed iron-base alloy XF-818 both in air and 15 MPa hydrogen.

  15. Achilles Tendon Rupture

    PubMed Central

    Wertz, Jess; Galli, Melissa; Borchers, James R.

    2013-01-01

    Context: Achilles tendon (AT) rupture in athletes is increasing in incidence and accounts for one of the most devastating sports injuries because of the threat to alter or end a career. Despite the magnitude of this injury, reliable risk assessment has not been clearly defined, and prevention strategies have been limited. The purpose of this review is to identify potential intrinsic and extrinsic risk factors for AT rupture in aerial and ground athletes stated in the current literature. Evidence Acquisition: A MEDLINE search was conducted on AT rupture, or “injury” and “risk factors” and “athletes” from 1980 to 2011. Emphasis was placed on epidemiology, etiology, and review articles focusing on the risk for lower extremity injury in runners and gymnasts. Thirty articles were reviewed, and 22 were included in this assessment. Results: Aerial and ground athletes share many intrinsic risk factors for AT rupture, including overuse and degeneration of the tendon as well as anatomical variations that mechanically put an athlete at risk. Older athletes, athletes atypical in size for their sport, high tensile loads, leg dominance, and fatigue also may increase risk. Aerial athletes tend to have more extrinsic factors that play a role in this injury due to the varying landing surfaces from heights and technical maneuvers performed at various skill levels. Conclusion: Risk assessment for AT rupture in aerial and ground athletes is multivariable and difficult in terms of developing prevention strategies. Quantitative measures of individual risk factors may help identify major contributors to injury. PMID:24427410

  16. Arterial distensibility in patients with ruptured and unruptured intracranial aneurysms: Is it a predisposing factor for rupture risk?

    PubMed Central

    Dusak, Abdurrahim; Kamasak, Kaan; Goya, Cemil; Adin, Mehmet E.; Elbey, Mehmet A.; Bilici, Aslan

    2013-01-01

    Background A risk factor assessment that reliably predicts whether patients are predisposed to intracranial aneurysm (IA) rupture has yet to be formulated. As such, the clinical management of unruptured IA remains unclear. Our aim was to determine whether impaired arterial distensibility and hypertrophic remodeling might be indicators of risk for IA rupture. Material/Methods The study population (n=49) was selected from consecutive admissions for either unruptured IA (n=23) or ruptured IA (n=26) from January to December 2010. Hemodynamic measures were taken from every patient, including systolic and diastolic blood pressure using a sphygmomanometer. Unruptured IA and ruptured IA characteristics, including aneurysmal shape, size, angle, aspect ratio, and bottleneck factor, were measured and calculated from transverse brain CT angiography images. With ultrasound, the right common carotid artery intima-media thickness was measured, as well as the lumen diameter during systole and diastole. Arterial wall strain, distensibility, stiffness index, and elastic modulus were calculated and compared between patients with unruptured IAs and ruptured IAs. A p-value less than 0.05 was considered statistically significant. Results General demographic data did not differ between patients with unruptured IAs and ruptured IAs. Greater mean intima-media thickness (p=0.013), mean stiffness index (p=0.044), and mean elastic modulus (p=0.026) were observed for patients with ruptured IAs. Moreover, mean strain (p=0.013) and mean distensibility (p=0.024) were decreased in patients with ruptured IAs. Conclusions Patients with ruptured IAs demonstrated decreased arterial distensibility and increased intima-media thickness at the level of the carotid arteries. By measuring these parameters via ultrasound, it may be possible to predict whether patients with existing IAs might rupture and hemorrhage into the subarachnoid space. PMID:23974299

  17. Arachnoid cyst spontaneous rupture.

    PubMed

    Marques, Inês Brás; Vieira Barbosa, José

    2014-01-01

    Arachnoid cysts are benign congenital cerebrospinal fluid collections, usually asymptomatic and diagnosed incidentally in children or adolescents. They may become symptomatic after enlargement or complications, frequently presenting with symptoms of intracranial hypertension. We report an unusual case of progressive refractory headache in an adult patient due to an arachnoid cyst spontaneous rupture. Although clinical improvement occurred with conservative treatment, the subdural hygroma progressively enlarged and surgical treatment was ultimately needed. Spontaneous rupture is a very rare complication of arachnoid cysts. Accumulation of cerebrospinal fluid accumulation in the subdural space causes sustained intracranial hypertension that may be life-threatening and frequently requires surgical treatment. Patients with arachnoid cysts must be informed on their small vulnerability to cyst rupture and be aware that a sudden and severe headache, especially if starting after minor trauma or a Valsalva manoeuvre, always requires medical evaluation. PMID:24581205

  18. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Protection of oxygen equipment from rupture... Equipment Miscellaneous Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient strength to withstand the maximum pressure and temperature,...

  19. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Protection of oxygen equipment from rupture... Equipment Miscellaneous Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient strength to withstand the maximum pressure and temperature,...

  20. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Protection of oxygen equipment from rupture... Equipment Miscellaneous Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient strength to withstand the maximum pressure and temperature,...

  1. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Protection of oxygen equipment from rupture... Equipment Miscellaneous Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient strength to withstand the maximum pressure and temperature,...

  2. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Protection of oxygen equipment from rupture... Equipment Miscellaneous Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient strength to withstand the maximum pressure and temperature,...

  3. Blunt traumatic pericardial rupture.

    PubMed Central

    Levine, A J; Collins, F J

    1995-01-01

    A 28-year-old man presented with left chest, head and limb injuries following a road traffic accident (RTA). Increasing haemodynamic instability necessitated an emergency left thoracotomy at which a complete rupture of the pericardium and herniation of the heart was found. After repair, the patient made an uneventful post-operative recovery. The aetiology, investigation and management of this rare injury is discussed. Images Fig. 1 PMID:7640832

  4. Composite Stress Rupture NDE Research and Development Project (Kevlar[R] and Carbon)

    NASA Technical Reports Server (NTRS)

    Saulsberry, Regor

    2010-01-01

    The objective was to develop and demonstrate nondestructive evaluation (NDE) techniques capable of assessing stress rupture related strength degradation for carbon composite pressure vessels, either in a structural health monitoring (SHM) or periodic inspection mode.

  5. Creep-rupture reliability analysis

    NASA Technical Reports Server (NTRS)

    Peralta-Duran, A.; Wirsching, P. H.

    1984-01-01

    A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

  6. Isolated rupture of the teres major tendon.

    PubMed

    Lester, Jonathan D; Boselli, Karen J; Kim, Paul D; Ahmad, Christopher S

    2010-11-01

    Acute isolated rupture of the teres major is an uncommon injury. This article presents the first report of midterm subjective and objective functional results following nonoperative management of an isolated teres major rupture. A 30-year-old right hand dominant man presented after a waterskiing traction injury to his left upper extremity. On physical examination, the patient had swelling and retraction of the teres major at the lower scapular border, which was accentuated with resisted adduction of the extremity. His teres major attachment at the humerus was not palpable. Magnetic resonance imaging revealed an isolated teres major tendon rupture. The patient was treated non-operatively with a rehabilitation protocol emphasizing rotator cuff, periscapular, and latissimus muscle strengthening. By 3 months postinjury, the patient had returned to all of his usual sporting activities, despite a persistent muscle retraction deformity over the teres major. At 3-year follow-up, the patient had no subjective complaints in the injured extremity and excellent functional outcome scores. A mean 37 kg loss of internal rotation strength (as measured by dynamometer) in the affected extremity with the arm abducted to 90° existed, although this difference was not subjectively appreciable. Although previously published reports have presented various options for the management of teres major injuries, the present case demonstrates that nonoperative treatment can produce excellent midterm subjective results in spite of objective internal rotation weakness. PMID:21053871

  7. [Achilles tendon rupture].

    PubMed

    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. PMID:10798233

  8. Strength enhancement process for prealloyed powder superalloys

    NASA Technical Reports Server (NTRS)

    Waters, W. J.; Freche, J. C.

    1977-01-01

    A technique involving superplastic processing and high pressure autoclaving was applied to a nickel base prealloyed powder alloy. Tensile strengths as high as 2865 MN/sq m at 480 C were obtained with as-superplastically deformed material. Appropriate treatments yielding materials with high temperature tensile and stress rupture strengths were also devised.

  9. Spontaneous rupture on irregular faults

    NASA Astrophysics Data System (ADS)

    Liu, C.

    2014-12-01

    It is now know (e.g. Robinson et al., 2006) that when ruptures propagate around bends, the rupture velocity decrease. In the extreme case, a large bend in the fault can stop the rupture. We develop a 2-D finite difference method to simulate spontaneous dynamic rupture on irregular faults. This method is based on a second order leap-frog finite difference scheme on a uniform mesh of triangles. A relaxation method is used to generate an irregular fault geometry-conforming mesh from the uniform mesh. Through this numerical coordinate mapping, the elastic wave equations are transformed and solved in a curvilinear coordinate system. Extensive numerical experiments using the linear slip-weakening law will be shown to demonstrate the effect of fault geometry on rupture properties. A long term goal is to simulate the strong ground motion near the vicinity of bends, jogs, etc.

  10. Ruptured thought: rupture as a critical attitude to nursing research.

    PubMed

    Beedholm, Kirsten; Lomborg, Kirsten; Frederiksen, Kirsten

    2014-04-01

    In this paper, we introduce the notion of ‘rupture’ from the French philosopher Michel Foucault, whose studies of discourse and governmentality have become prominent within nursing research during the last 25 years. We argue that a rupture perspective can be helpful for identifying and maintaining a critical potential within nursing research. The paper begins by introducing rupture as an inheritance from the French epistemological tradition. It then describes how rupture appears in Foucault's works, as both an overall philosophical approach and as an analytic tool in his historical studies. Two examples of analytical applications of rupture are elaborated. In the first example, rupture has inspired us to make an effort to seek alternatives to mainstream conceptions of the phenomenon under study. In the second example, inspired by Foucault's work on discontinuity, we construct a framework for historical epochs in nursing history. The paper concludes by discussing the potential of the notion of rupture as a response to the methodological concerns regarding the use of Foucault-inspired discourse analysis within nursing research. We agree with the critique of Cheek that the critical potential of discourse analysis is at risk of being undermined by research that tends to convert the approach into a fixed method. PMID:24741691

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

    NASA Astrophysics Data System (ADS)

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

    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.

  12. Spontaneous Iliac Vein Rupture

    PubMed Central

    Kim, Dae Hwan; Park, Hyung Sub; Lee, Taeseung

    2015-01-01

    Spontaneous iliac vein rupture (SIVR) is a rare entity, which usually occurs without a precipitating factor, but can be a life-threatening emergency often requiring an emergency operation. This is a case report of SIVR in a 62-year-old female who presented to the emergency room with left leg swelling. Workup with contrast-enhanced computed tomography revealed a left leg deep vein thrombosis with May-Thurner syndrome and a hematoma in the pelvic cavity without definite evidence of arterial bleeding. She was managed conservatively without surgical intervention, and also underwent inferior vena cava filter insertion and subsequent anticoagulation therapy for pulmonary thromboembolism. This case shows that SIVR can be successfully managed with close monitoring and conservative management, and anticoagulation may be safely applied despite the patient presenting with venous bleeding. PMID:26217647

  13. Steam generator tube rupture study

    E-print Network

    Free, Scott Thomas

    1986-01-01

    This report describes our investigation of steam generator behavior during a postulated tube rupture accident. Our study was performed using the steam generator, thermal-hydraulic analysis code THERMIT-UTSG. The purpose ...

  14. Blood vessel rupture by cavitation.

    PubMed

    Chen, Hong; Brayman, Andrew A; Bailey, Michael R; Matula, Thomas J

    2010-08-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion can cause vessel distention, and bubble collapse can lead to vessel invagination. Liquid jets were also observed to form. Our results suggest that all three mechanisms, vessel distention, invagination and liquid jets, can contribute to vessel rupture. PMID:20680255

  15. Blood vessel rupture by cavitation

    PubMed Central

    Chen, Hong; Brayman, Andrew A.; Bailey, Michael R.

    2011-01-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion can cause vessel distention, and bubble collapse can lead to vessel invagination. Liquid jets were also observed to form. Our results suggest that all three mechanisms, vessel distention, invagination and liquid jets, can contribute to vessel rupture. PMID:20680255

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

    NASA Technical Reports Server (NTRS)

    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.

  17. Evaluation of mechanical properties of high strength concrete for prestressed concrete bridge design 

    E-print Network

    Chompreda, Praveen

    2001-01-01

    tensile strength, modulus of elasticity, and flexural strength (modulus of rupture) at 7, 28, and 56 days. Creep and shrinkage were also monitored. Statistical analyses were conducted to determine the probability distribution, bias factors...

  18. Complex rupture during the 12 January 2010 Haiti earthquake

    USGS Publications Warehouse

    Hayes, G.P.; Briggs, R.W.; Sladen, A.; Fielding, E.J.; Prentice, C.; Hudnut, K.; Mann, P.; Taylor, F.W.; Crone, A.J.; Gold, R.; Ito, T.; Simons, M.

    2010-01-01

    Initially, the devastating Mw 7.0, 12 January 2010 Haiti earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillog-Plantain Garden fault zone. Here, we combine seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process may have involved slip on multiple faults. Primary surface deformation was driven by rupture on blind thrust faults with only minor, deep, lateral slip along or near the main Enriquillog-Plantain Garden fault zone; thus the event only partially relieved centuries of accumulated left-lateral strain on a small part of the plate-boundary system. Together with the predominance of shallow off-fault thrusting, the lack of surface deformation implies that remaining shallow shear strain will be released in future surface-rupturing earthquakes on the Enriquillog-Plantain Garden fault zone, as occurred in inferred Holocene and probable historic events. We suggest that the geological signature of this earthquakeg-broad warping and coastal deformation rather than surface rupture along the main fault zoneg-will not be easily recognized by standard palaeoseismic studies. We conclude that similarly complex earthquakes in tectonic environments that accommodate both translation and convergenceg-such as the San Andreas fault through the Transverse Ranges of Californiag-may be missing from the prehistoric earthquake record. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  19. Complex rupture during the 12 January 2010 Haiti earthquake

    NASA Astrophysics Data System (ADS)

    Hayes, G. P.; Briggs, R. W.; Sladen, A.; Fielding, E. J.; Prentice, C.; Hudnut, K.; Mann, P.; Taylor, F. W.; Crone, A. J.; Gold, R.; Ito, T.; Simons, M.

    2010-11-01

    Initially, the devastating Mw 7.0, 12 January 2010 Haiti earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillo-Plantain Garden fault zone. Here, we combine seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process may have involved slip on multiple faults. Primary surface deformation was driven by rupture on blind thrust faults with only minor, deep, lateral slip along or near the main Enriquillo-Plantain Garden fault zone; thus the event only partially relieved centuries of accumulated left-lateral strain on a small part of the plate-boundary system. Together with the predominance of shallow off-fault thrusting, the lack of surface deformation implies that remaining shallow shear strain will be released in future surface-rupturing earthquakes on the Enriquillo-Plantain Garden fault zone, as occurred in inferred Holocene and probable historic events. We suggest that the geological signature of this earthquake-broad warping and coastal deformation rather than surface rupture along the main fault zone-will not be easily recognized by standard palaeoseismic studies. We conclude that similarly complex earthquakes in tectonic environments that accommodate both translation and convergence-such as the San Andreas fault through the Transverse Ranges of California-may be missing from the prehistoric earthquake record.

  20. Fault Branching and Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Dmowska, R.; Rice, J. R.; Kame, N.

    2002-12-01

    Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing also on the main fault), or rather involved arrest by a barrier on the original fault and jumping [Harris and Day, JGR, 1993] to a neighboring fault on which rupture propagated bilaterally to form what appears as a backward-branched structure. Our studies [Poliakov et al., JGR in press, 2002; Kame et al, EOS, 2002] of stress fields around a dynamically moving mode II crack tip show a clear tendency to branch from the straight path at high rupture speeds, but the stress fields never allow the rupture path to directly turn through highly obtuse angles, and hence that mechanism is unlikely. In contrast, study of fault maps in the vicinity of the Kp to HV fault transition [Sowers et al., 1994], discussed as case (1) above, strongly suggest that the large-angle branching occurred as a jump, which we propose as the likely general mechanism. Implications for the Nakata et al. [1998] aim of inferring rupture directivity from branch geometry is that this will be possible only when rather detailed characterization (by surface geology, seismic relocation, trapped waves) of fault connectivity can be carried out in the vicinity of the branching junction, to ascertain whether direct turning of the rupture path through an angle, or jumping and then propagating bilaterally, were involved in prior events. They have opposite implications for how we would associate past directivity with a (nominally) branched fault geometry.

  1. Creep-rupture tests of internally pressurized Inconel 702 tubes

    NASA Technical Reports Server (NTRS)

    Gumto, K. H.

    1973-01-01

    Seamless Inconel 702 tubes with 0.375-in. outside diameter and 0.025-in. wall thickness were tested to failure at temperatures from 1390 to 1575 F and internal helium pressures from 700 to 1800 psi. Lifetimes ranged from 29 to 1561 hr. The creep-rupture strength of the tubes was about 70 percent lower than that of sheet specimens. Larson-Miller correlations and photomicrographs of some specimens are presented.

  2. Coupling a geodynamic seismic cycling model to rupture dynamic simulations

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; van Dinther, Ylona

    2014-05-01

    The relevance and results of dynamic rupture scenarios are implicitly linked to the geometry and pre-existing stress and strength state on a fault. The absolute stresses stored along faults during interseismic periods, are largely unquantifiable. They are, however, pivotal in defining coseismic rupture styles, near-field ground motion, and macroscopic source properties (Gabriel et al., 2012). Obtaining these in a physically consistent manner requires seismic cycling models, which directly couple long-term deformation processes (over 1000 year periods), the self-consistent development of faults, and the resulting dynamic ruptures. One promising approach to study seismic cycling enables both the generation of spontaneous fault geometries and the development of thermo-mechanically consistent fault stresses. This seismo-thermo-mechanical model has been developed using a methodology similar to that employed to study long-term lithospheric deformation (van Dinther et al., 2013a,b, using I2ELVIS of Gerya and Yuen, 2007). We will innovatively include the absolute stress and strength values along physically consistent evolving non-finite fault zones (regions of strain accumulation) from the geodynamic model into dynamic rupture simulations as an initial condition. The dynamic rupture simulations will be performed using SeisSol, an arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) scheme (Pelties et al., 2012). The dynamic rupture models are able to incorporate the large degree of fault geometry complexity arising in naturally evolving geodynamic models. We focus on subduction zone settings with and without a splay fault. Due to the novelty of the coupling, we first focus on methodological challenges, e.g. the synchronization of both methods regarding the nucleation of events, the localization of fault planes, and the incorporation of similar frictional constitutive relations. We then study the importance of physically consistent fault stress, strength, and geometry input for dynamic rupture propagation in terms of rupture path and dynamics. On the other hand, it will provide the opportunity to compare slow earthquake akin events developing in quasi-static geodynamic model to fully dynamic ruptures in terms of coseismic displacements and stress changes. Gabriel, A.-A. (2012), J.-P. Ampuero, L. A. Dalguer, and P. M. Mai, The transition of dynamic rupture modes in elastic media, J. Geophys. Res., 117(B9), 01480227. Gerya, T., and D. Yuen (2007), Robust characteristics method for modelling multiphase visco-elasto-plastic thermo-mechanical problems, Phys. Earth Planet In., 163(1-4), 83-105. Pelties, C. (2012), J. De la Puente, J.-P. Ampuero, G. B. Brietzke, and M. Käser Three-Dimensional Dynamic Rupture, Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, J. Geophys. Res., 117(B2), B02309. van Dinther, Y. (2013a), T.V. Gerya, L.A. Dalguer, F. Corbi, F. Funiciello, and P.M. Mai, The seismic cycle at subduction thrusts: 2. Dynamic implications of geodynamic simulations validated with laboratory models, J. Geophys. Res., 118(4), 1502-1525. van Dinther, Y. (2013b), T.V. Gerya, L.A. Dalguer, P.M. Mai, G. Morra, and D. Giardini, The seismic cycle at subduction thrusts: insights from seismo-thermo-mechanical models, J. Geophys. Res., 118, 6183-6202.

  3. Abdominal aortic aneurysms. Ultrasonic measurement of the transverse diameter and its prognostic significance in the light of pathological observations.

    PubMed Central

    McGregor, J. C.

    1977-01-01

    The risk of rupture of an abdominal aortic aneurysm is related to size. Pathological observations suggest that there is usually an asymmetric formation of mural thrombus in the aneurysm sac and that rupture occurs more commonly through the lateral walls where there would be less. Ultrasonic estimation of the transverse diameter of an aneurysm offers a useful clinical method of monitoring size and likelihood of rupture. Images Fig. 2 Fig. 3a Fig. 3b Fig. 4 PMID:604987

  4. Spontaneous splenic rupture in pregnancy

    PubMed Central

    Elghanmi, Adil; Mohamed, Jou; Khabouz, Samira

    2015-01-01

    Splenic rupture during pregnancy is a rare and can frequently be a misdiagnosed pathology. This rupture is associated with a high maternal and fetal mortality rate. A 26 years old Moroccan woman para II gravida II presented at the third stage of pregnancy with acute onset of severe abdominal pain. She developed immediately a hypovolemic shock. After both a physical and sonographical exam, it was revealed that it was due to a massive hemoperitoneum. Therefore, an emergent laparotomy and cesarean delivery with abdominal exploration were performed; also, an active bleeding was identified at the splenic hilum consistent with splenic rupture. Through this case report, we want to raise awareness of this surgical emergency that requires immediate recognition because any delay can lead to catastrophic consequences

  5. Spontaneous rupture of a neobladder.

    PubMed

    Martínez Jabaloyas, J M; Vera Donoso, C D; Morera Martínez, J F; Ruiz Cerdá, J L; Beamud Gómez, A; Jiménez Cruz, J F

    1994-01-01

    The spontaneous rupture of neobladder is an extremely rare entity of which there only exists one formerly reported case in the world literature. It is far more common after enterocystoplasty for augmentation (19 reported cases). We describe here the spontaneous rupture of a neobladder 8 months after performing cystectomy and bladder replacement by an enterocystoplasty in order to treat a bladder carcinoma. In this case the patient showed symptoms and signs of acute peritonitis. The diagnosis was carried out using a cystogram and the treatment consisted of a laparotomy with closure of the perforation and drainage of the peritoneal cavity. PMID:8200411

  6. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

  7. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

  8. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

  9. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

  10. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

  11. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  12. Spontaneous rupture of vaginal enterocele.

    PubMed

    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. PMID:4015021

  13. Transverse Force on Quarks in DIS

    E-print Network

    Matthias Burkardt

    2015-10-11

    Generalized Parton Distributions (GPDs) provide information on the distribution of quarks in impact paarmeter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. %The strength of that force can be related to twist-3 PDFs. This force when acting along the whole trajectory of the active quark leads to a transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark Orbital Angular Momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.

  14. Factors influencing maternal survival in ruptured uterus.

    PubMed

    Megafu, U

    1985-12-01

    Ruptured uterus continues to be a common obstetric hazard in under developed countries. The commonest cause is spontaneous rupture from obstructed labor in the multipara. There was not a single rupture in the primipara. Rupture following previous cesarean section scar is also common. The most effective way of management is to correct fluid and blood loss followed by laparotomy and subtotal hysterectomy. This method gave a lower mortality than either repair and sterilization or total hysterectomy. Adequate pre-operative resuscitation and time interval between rupture and operation also influences mortality rate. The experience of the surgeon is another vital factor in determining mortality rate. PMID:2868942

  15. Thrust-type subduction-zone earthquakes and seamount asperites: A physical model for seismic rupture

    SciTech Connect

    Cloos, M. )

    1992-07-01

    A thrust-type subduction-zone earthquake of M{sub W} 7.6 ruptures an area of {approximately}6,000 km{sup 2}, has a seismic slip of {approximately}1 m, and is nucleated by the rupture of an asperity {approximately}25km across. A model for thrust-type subduction-zone seismicity is proposed in which basaltic seamounts jammed against the base of the overriding plate act as strong asperities that rupture by stick-slip faulting. A M{sub W} 7.6 event would correspond to the near-basal rupture of a {approximately}2-km-tall seamount. The base of the seamount is surrounded by a low shear-strength layer composed of subducting sediment that also deforms between seismic events by distributed strain (viscous flow). Planar faults form in this layer as the seismic rupture propagates out of the seamount at speeds of kilometers per second. The faults in the shear zone are disrupted after the event by aseismic, slow viscous flow of the subducting sediment layer. Consequently, the extent of fault rupture varies for different earthquakes nucleated at the same seamount asperity because new fault surfaces form in the surrounding subducting sediment layer during each fast seismic rupture.

  16. Greater fear of re-injury and increased tibial translation in patients who later sustain an ACL graft rupture or a contralateral ACL rupture: a pilot study.

    PubMed

    Tagesson, Sofi; Kvist, Joanna

    2016-01-01

    The aim was to compare fear of re-injury, patient reported function, static and dynamic tibial translation and muscle strength assessed before and 5 weeks after an anterior cruciate ligament (ACL) reconstruction between individuals who sustained a subsequent ACL graft rupture or a contralateral ACL injury within 5 years after the reconstruction, and individuals with no subsequent injury. Nineteen patients were investigated before, and 5 weeks after an ACL reconstruction with a quadruple hamstring tendon graft. At 5 years follow up, 3 patients had sustained an ACL graft rupture and 2 patients had sustained a contralateral ACL rupture. Fear of re-injury, confidence with the knee, patient reported function, activity level, static and dynamic tibial translation and muscle strength were assessed. The re-injured group reported greater fear of re-injury and had greater static tibial translation in both knees before the ACL reconstruction compared to those who did not sustain another ACL injury. There were no other differences between groups. In conclusion, fear of re-injury and static tibial translation before the index ACL reconstruction were greater in patients who later on suffered an ACL graft rupture or a contralateral ACL rupture. These factors may predict a subsequent ACL injury. PMID:25894209

  17. Spontaneous rupture of the ureter

    PubMed Central

    Eken, Alper; Akbas, Tugana; Arpaci, Taner

    2015-01-01

    Spontaneous rupture of the ureter is a very rare condition and usually results from ureteral obstruction by a calculus. Only theoretical mecha­nisms have been proposed and no possible explanation has yet been reported in the literature. Intravenous contrast-enhanced computed tomography is the most informative study with high sensitivity. Treatment should be individualised, and depends on the state of the patient. Minimally invasive endourological procedures with double-J catheter placement and percutaneous drainage offer excellent results. Conservative management with analgesics and antibiotic coverage may be an alternative to surgery. Herein, we present a case of spontaneous rupture of the proximal ureter with no evidence of an underlying pathological condition. PMID:25715862

  18. IMPROVING THE PERFORMANCE CREEP STRENGTH-ENHANCED FERRITIC STEELS

    E-print Network

    Pennycook, Steve

    consistently higher strength than commercial Grade 92 steel. Stress rupture testing of similar specimens, and are increasingly being specified and used for superheater tubing and main steam piping in coal-fired steam boilers significantly reduce creep strength. Also, the size and orientation of the FG- HAZ lead to high triaxial stress

  19. Environmental Durability and Stress Rupture of EBC/CMCs

    NASA Technical Reports Server (NTRS)

    Appleby, Matthew; Morscher, Gregory N.; Zhu, Dongming

    2012-01-01

    This research focuses on the strength and creep performance of SiC fiber-reinforced SiC ceramic matrix composite (CMC) environmental barrier coating (EBC) systems under complex simulated engine environments. Tensile-strength and stress-rupture testing was conducted to illustrate the material properties under isothermal and thermal gradient conditions. To determine material durability, further testing was conducted under exposure to thermal cycling, thermal gradients and simulated combustion environments. Emphasis is placed on experimental techniques as well as implementation of non-destructive evaluation, including modal acoustic emission and electrical resistivity monitoring, to characterize strength degradation and damage mechanisms. Currently, little is known about the behavior of EBC-CMCs under these conditions; consequently, this work will prove invaluable in the development of structural components for use in high temperature applications.

  20. Achilles tendon rupture in badminton.

    PubMed Central

    Kaalund, S; Lass, P; Høgsaa, B; Nøhr, M

    1989-01-01

    The typical badminton player with an Achilles tendon rupture is 36 years old and, despite limbering up, is injured at the rear line in a sudden forward movement. He resumes work within three months and has a slight lack of dorsiflexion in the ankle as the main complication. Most patients resume badminton within one year, but some finish their sports career, mainly due to fear of a new injury. The investigation discusses predisposing factors and prophylactic measures. PMID:2605439

  1. The deterministic nature of earthquake rupture.

    PubMed

    Olson, Erik L; Allen, Richard M

    2005-11-10

    Understanding the earthquake rupture process is central to our understanding of fault systems and earthquake hazards. Multiple hypotheses concerning the nature of fault rupture have been proposed but no unifying theory has emerged. The conceptual hypothesis most commonly cited is the cascade model for fault rupture. In the cascade model, slip initiates on a small fault patch and continues to rupture further across a fault plane as long as the conditions are favourable. Two fundamental implications of this domino-like theory are that small earthquakes begin in the same manner as large earthquakes and that the rupture process is not deterministic--that is, the size of the earthquake cannot be determined until the cessation of rupture. Here we show that the frequency content of radiated seismic energy within the first few seconds of rupture scales with the final magnitude of the event. We infer that the magnitude of an earthquake can therefore be estimated before the rupture is complete. This finding implies that the rupture process is to some degree deterministic and has implications for the physics of the rupture process. PMID:16281033

  2. Transversity: Theory and phenomenology

    SciTech Connect

    D'Alesio, Umberto

    2013-04-15

    The distribution of transversely polarized quarks inside a transversely polarized nucleon, known as transversity, encodes a basic piece of information on the nucleon structure, sharing the same status with the more familiar unpolarized and helicity distributions. I will review its properties and discuss different ways to access it, with highlights and limitations. Recent phenomenological extractions and perspectives are also presented.

  3. Early second trimester uterine scar rupture

    PubMed Central

    Bharatnur, Sunanda; Hebbar, Shripad; G, Shyamala

    2013-01-01

    Spontaneous uterine scar rupture can be lethal in pregnant women. A spontaneous uterine scar rupture in the early mid-trimester is rare and difficult to diagnose. This is a case of a 30-year-old woman (G2P1L1) at 19?weeks of gestation and having undergone a previous caesarean section presented with acute abdomen in shock. Laparotomy revealed a uterine scar rupture, which was resutured after evacuation of products of conception. This case merits that the uterine rupture should be considered as a differential diagnosis in pregnant women presenting with acute abdomen. In this case, although there was uterine rupture in the second trimester and a complete placental separation, fetus was alive which is quite unusual in patients presenting with rupture uterus. PMID:24326433

  4. Method and apparatus for determining tensile strength

    DOEpatents

    Ratigan, Joe L. (Rapid City, SD)

    1984-01-01

    A method and apparatus for determining the statistical distribution of apparent tensile strength of rock, the size effect with respect to tensile strength, as well as apparent deformation modulus of both intact and fractured or jointed rock. The method is carried out by inserting a plug of deformable material, such as rubber, in an opening of a specimen to be tested. The deformable material is loaded by an upper and lower platen until the specimen ruptures, whereafter the tensile strength is calculated based on the parameters of the test specimen and apparatus.

  5. Method and apparatus for determining tensile strength

    DOEpatents

    Ratigan, J.L.

    1982-05-28

    A method and apparatus is described for determining the statistical distribution of apparent tensile strength of rock, the size effect with respect to tensile strength, as well as apparent deformation modulus of both intact and fractured or jointed rock. The method is carried out by inserting a plug of deformable material, such as rubber, in an opening of a specimen to be tested. The deformable material is loaded by an upper and lower platen until the specimen ruptures, whereafter the tensile strength is calculated based on the parameters of the test specimen and apparatus.

  6. Strength Testing.

    ERIC Educational Resources Information Center

    Londeree, Ben R.

    1981-01-01

    Postural deviations resulting from strength and flexibility imbalances include swayback, scoliosis, and rounded shoulders. Screening tests are one method for identifying strength problems. Tests for the evaluation of postural problems are described, and exercises are presented for the strengthening of muscles. (JN)

  7. Nondestructive Evaluation and Monitoring Results from COPV Accelerated Stress Rupture Testing, NASA White Sands Test Facility (WSTF)

    NASA Technical Reports Server (NTRS)

    Saulsberry Regor

    2010-01-01

    Develop and demonstrate NDE techniques for real-time characterization of CPVs and, where possible, identification of NDE capable of assessing stress rupture related strength degradation and/or making vessel life predictions (structural health monitoring or periodic inspection modes). Secondary: Provide the COPV user and materials community with quality carbon/epoxy (C/Ep) COPV stress rupture progression rate data. Aid in modeling, manufacturing, and application of COPVs for NASA spacecraft.

  8. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  9. Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils

    NASA Astrophysics Data System (ADS)

    Osman, H.; Borhana, A.; Tamin, M. N.

    2014-08-01

    Creep rupture properties of austenitic stainless steel foil, 347SS, used in compact recuperators have been evaluated at 700 °C in the stress range of 54-221 MPa to establish the baseline behavior for its extended use. Creep curves of the foil show that the primary creep stage is brief and creep life is dominated by tertiary creep deformation with rupture lives in the range of 10-2000 h. Results are compared with properties of bulk specimens tested at 98 and 162 MPa. Thin foil 347SS specimens were found to have higher creep rates and higher rupture ductility than their bulk specimen counterparts. Power law relationship was obtained between the minimum creep rate and the applied stress with stress exponent value, n = 5.7. The value of the stress exponent is indicative of the rate-controlling deformation mechanism associated with dislocation creep. Nucleation of voids mainly occurred at second-phase particles (chromium-rich M23C6 carbides) that are present in the metal matrix by decohesion of the particle-matrix interface. The improvement in strength is attributed to the precipitation of fine niobium carbides in the matrix that act as obstacles to the movement of dislocations.

  10. Proximal humerus shaft fracture after pectoralis major tendon rupture repair.

    PubMed

    Silverstein, Jeff A; Goldberg, Ben; Wolin, Preston

    2011-06-01

    Surgical repair of a complete pectoralis major tendon rupture at the humeral insertion has superior results compared to nonoperative treatment. To our knowledge, a proximal humerus shaft fracture occurring at the site of the bone trough and cortical drill holes after a pectoralis major tendon rupture repair has not been reported in the literature.A 45-year-old man sustained an acute left pectoralis major tendon rupture at the humeral insertion while performing a bench press maneuver. He underwent acute surgical repair. Approximately 8 weeks postoperatively, the patient fell from a standing height and sustained a proximal humerus shaft fracture through the repair site at the bone trough. Three days after the fracture, the patient underwent open reduction and internal fixation of the proximal humerus shaft fracture and exploration of the pectoralis major tendon repair. The fracture was found to be at the level of the repair site, and the pectoralis major tendon was completely intact to the distal fragment. The fracture healed uneventfully, and the patient regained full motion and strength of his extremity with no limitations.Any type of surgical fixation that creates a hole in the humerus or decreases the cross-sectional area such as a bone trough creates a stress riser. Patients undergoing pectoralis tendon repair that involves violating the humerus with a bone trough or hole have a slight risk of postoperative humerus fracture, especially if sustaining an early traumatic event such as a fall. PMID:21667914

  11. Rupture to the Trench: Dynamic Rupture Simulations of the 11 March 2011 Tohoku Earthquake

    E-print Network

    Dunham, Eric M.

    Rupture to the Trench: Dynamic Rupture Simulations of the 11 March 2011 Tohoku Earthquake on seismic surveys of the Japan Trench. The fault obeys rate-and-state friction with standard logarithmic of the fault driving the rupture through the velocity- strengthening region to the trench. We validate

  12. CREEP STRENGTH OF HIGH CR FERRITIC STEELS DESIGNED USING NEURAL NETWORKS AND PHASE STABILITY CALCULATIONS

    E-print Network

    Cambridge, University of

    in the creep resistance of 9- 12%Cr steels used for boiler header/piping and steam turbine rotor applications time ago (4). The published work predicted excellent stress rupture strength, double or greater than

  13. Delayed spontaneous rupture of an ileocolonic neobladder.

    PubMed

    Thompson, S T; Kursh, E D

    1992-12-01

    A case of delayed spontaneous rupture of an ileocolonic neobladder and subsequent peritonitis 4 years after the initial operation is reported. Many of the features of this case are similar to those noted in recent reports of spontaneous rupture of an augmented bladder and it is postulated that the etiology is the same. PMID:1433631

  14. Myocardial infarction complicated by ventricular septal rupture.

    PubMed

    Sahjian, Michael; Ventriglia, Rich; Bolton, Lauri

    2012-01-01

    Transporting patients with an ST segment elevation myocardial infarction (STEMI) is a fairly common practice for most critical care transport teams. When a STEMI is complicated by ventricular septal rupture, the care can become more challenging, especially if the rupture is not yet diagnosed. This article describes such a transport and reviews the pathophysiology of the process along with treatment options. PMID:22225564

  15. FRP rupture strains in FRP wrapped columns 

    E-print Network

    Li, Shiqing

    2012-06-25

    and bending of the FRP ring at the gap due to change of curvature caused by the relative moment of the two half disks, as the FRP (as a brittle material) ruptures once the maximum strain at one of these locations reaches the FRP rupture strain. A list...

  16. Genetic basis of cranial cruciate ligament rupture (CCLR) in dogs.

    PubMed

    Baird, Arabella Elizabeth Gardiner; Carter, Stuart D; Innes, John F; Ollier, William E; Short, Andrea D

    2014-08-01

    Cranial Cruciate Ligament rupture (CCLR) is one of the most common forms of lameness in dogs and is analogous to rupture of the anterior cruciate ligament in humans, for which it can serve as a model. As there is a strong breed-related predisposition to CCLR in dogs, a study was undertaken to consider putative genetic components in susceptible dog breeds. A candidate gene, single nucleotide polymorphism (SNP) genotyping approach using MALDI-TOF mass spectrometry (Sequenom Ltd) was designed to investigate several CCLR-susceptible dog breeds and identify CCLR-associated genes/gene regions that may confer susceptibility or resistance. A meta-analysis was performed using the breed case/control candidate gene data to identify SNP associations that were common to the whole cohort of susceptible dogs. We identified SNPs in key genes involved in ligament strength, stability and extracellular matrix formation (COL5A1, COL5A2, COL1A1, COL3A1, COL11A1, COL24A1, FBN1, LOX, LTBP2) which were significantly associated with CCLR susceptibility across the dog breeds used in this study. These SNPs could have an involvement in CCLR due to a detrimental effect on ligament structure and strength. This is the first published candidate gene study that has revealed significant genetic associations with canine CCLR. PMID:24684544

  17. Pectoralis major tendon rupture: a biomechanical analysis of repair techniques.

    PubMed

    Hart, Nathan D; Lindsey, Derek P; McAdams, Timothy R

    2011-11-01

    Rupture of the insertion of the pectoralis major muscle to the proximal humerus is becoming a common injury. Repair of these ruptures increases patient satisfaction, strength, and cosmesis, and shortens return to competitive sports. Several repair techniques have been described, but recently many surgeons are using suture anchors. The traditional repair technique uses transosseous sutures, but no study has biomechanically compared the strength of these two repair techniques in human cadavers. Twelve fresh-frozen human shoulder specimens were dissected. The pectoralis major tendon insertion was cut from the bone and repaired using one of the two repair techniques: specimens were randomly assigned to transosseous trough with suture tied over bone versus four suture anchors. The fixation constructs were pulled to failure at 4?mm/s on a materials testing system. The mean ultimate failure load of the transosseous repairs was 611?N and the mean ultimate failure load of the suture anchor repair was 620?N. The mean stiffness of the transosseous repair was 32 and 28?N/mm for the suture anchor group. We found no statistically significant difference between these two repair techniques. PMID:21538507

  18. Cryogenic insulation strength and bond tester

    NASA Technical Reports Server (NTRS)

    Schuerer, P. H.; Ehl, J. H.; Prasthofer, W. P. (inventors)

    1985-01-01

    A method and apparatus for testing the tensile strength and bonding strength of sprayed-on foam insulation attached to metal cryogenic fuel tanks is described. A circular cutter is used to cut the insulation down to the surface of the metal tank to form plugs of the insulation for testing in situ on the tank. The apparatus comprises an electromechanical pulling device powered by a belt battery pack. The pulling device comprises a motor driving a mechanical pulling structure comprising a horizontal shaft connected to two bell cracks which are connected to a central member. When the lower end of member is attached to a fitting, which in turn is bonded to a plug, a pulling force is exerted on the plug sufficient to rupture it. The force necessary to rupture the plug or pull it loose is displayed as a digital read-out.

  19. Spontaneous rupture of the spleen operated in gynecological unit mistaken for ruptured hemorrhagic ovarian cyst: total splenectomy

    PubMed Central

    Eko, Filbert Eko; Fouelifack, Florent Ymele; de Paul, Elanga Vincent

    2014-01-01

    Spontaneous splenic rupture is always neglected when consulting acute abdominal pains in gynecological emergencies. It constitutes about 1% of all splenic ruptures and can be managed by abstention, surgery or embolization. We present the case of a young lady who was diagnosed of spontaneous rupture during surgery that was mistaken for ruptured hemorrhagic ovarian cyst and finally treated by total splenectomy. The pre-operative work up was absolute for a rupturred hemorrhagic cyst and secondariy for a ruptured ectopic gestation. PMID:25918564

  20. Mechanical strength of dental implants.

    PubMed

    Zonfrillo, G; Pratesi, F

    2008-01-01

    A series of mechanical strength tests have been carried out in order to characterize some dental implants. Most specimens tested were of the tapered-joint kind, but for comparison further tests have been carried out on screw-joined implants. The loads applied were similar to those existing in the typical working conditions of the component; however, in order to conform to the ISO standard 14801, loads higher than those achieved in working conditions were applied. The static characterization tests determined the strength of the system, with large deformations preceding rupture. The fatigue tests led to the determination of the fatigue limit of the dental implant, defined conventionally in these cases as the maximum value under which the system has a life of at least 2.106 cycles. The fatigue limit is higher than the stress that the teeth endure during the normal process of mastication, and it confirms the suitable structural design of the device. Failure analysis has shown that the fatigue crack leading to rupture commonly occurs in the section in which the hexagonal insert in the tapered joint begins. PMID:20740454

  1. Intermediate Temperature Stress Rupture of a Woven Hi-Nicalon, BN-Interphase, SiC Matric Composite in Air

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurst, Janet; Brewer, David

    1999-01-01

    Woven Hi-Nicalon (TM) reinforced melt-infiltrated SiC matrix composites were tested under tensile stress-rupture conditions in air at intermediate temperatures. A comprehensive examination of the damage state and the fiber properties at failure was performed. Modal acoustic emission analysis was used to monitor damage during the experiment. Extensive microscopy of the composite fracture surfaces and the individual fiber fracture surfaces was used to determine the mechanisms leading to ultimate failure. The rupture properties of these composites were significantly worse than expected compared to the fiber properties under similar conditions. This was due to the oxidation of the BN interphase. Oxidation occurred through the matrix cracks that intersected the surface or edge of a tensile bar. These oxidation reactions resulted in minor degradation to fiber strength and strong bonding of the fibers to one another at regions of near fiber-to-fiber contact. It was found that two regimes for rupture exist for this material: a high stress regime where rupture occurs at a fast rate and a low stress regime where rupture occurs at a slower rate. For the high stress regime, the matrix damage state consisted of through thickness cracks. The average fracture strength of fibers that were pulled-out (the final fibers to break before ultimate failure) was controlled by the slow-crack growth rupture criterion in the literature for individual Hi-Nicalon (TM) fibers. For the low stress regime, the matrix damage state consisted of microcracks which grew during the rupture test. The average fracture strength of fibers that were pulled-out in this regime was the same as the average fracture strength of individual fibers pulled out in as-produced composites tested at room temperature.

  2. P(t) Dependence of Transverse Flow in Relativistic Heavy-Ion Collisions 

    E-print Network

    Li, Bao-An; Ko, Che Ming; Li, GQ.

    1996-01-01

    The strength of transverse flow is examined as a function of transverse momentum p(t) using a simple, transversely moving thermal model and a more realistic, relativistic transport model. It is shown that the p(t) dependence reveals useful...

  3. Dynamic Interface Rupture in Extremely Heterogeneous Media

    NASA Astrophysics Data System (ADS)

    Uenishi, K.; Tsuji, K.

    2007-12-01

    Fracture experiments of monolithic brittle materials usually show the maximum speed of smooth rupture at some 30 % of the relevant shear wave speed. This experimental maximum rupture speed is by far lower than those predicted by theories and inferred from inversions of seismograms, and some seismic inversions (e.g., the 1979 Imperial Valley, 1992 Landers, 1999 Izmit, 2001 the central Kunlunshan and 2002 Denali earthquakes) even suggest the existence of supershear rupture speeds (i.e., rupture propagating faster than the relevant shear wave). Recently, Uenishi et al. ( SSJ Fall Meeting, 2004, 2005; AGU Fall Meeting, 2006) experimentally investigated dynamic fracture in monolithic hyperelastic materials under static mode-§ loading conditions with relatively high crack-parallel stresses. Using a high-speed digital video camera system, they showed that cracks may propagate supersonically even in homogeneous materials. However, the exact mechanism for rupture nucleation and the transition of a nucleated rupture from sub-Rayleigh to super-shear rupture speed has not been identified yet. In this contribution, we further develop our experimental system and investigate dynamic fracture in extremely heterogeneous media, consisting of thin fluid and solid films: Inside a wire frame (50mm high, 50mm wide), a flat soap film contacts a flat thin solid plastic film (20mm high, 20mm wide), under static tensile loading conditions. The rupture (crack), initiated at a point, propagates subsonically in the linear elastic fluid film (see e.g., Uenishi et al., SSJ Fall Meeting, 2006, for the dynamic rupture in monolithic fluid films). When the circular rupture front reaches the interface, the rupture advances along the interface and then it is "diffracted" at the two corners of the interface. We record the rupture propagation process utilizing our high-speed digital video camera at a frame rate of 20 ?s (20×10-6s). The observed results show that interface rupture propagation may accelerate (or even decelerate) and the dynamic rupture behavior is very sensitive to the geometry of the interface between the two films: (1) When the subsonic rupture front reaches the first rectangular corner, it accelerates around the corner and then advances supersonically along the interface; and (2) when the supersonic interface rupture front approaches the second corner (obtuse with respect to the rupture front in fluid), it bifurcates for a short period (400 ?s): the first branch unexpectedly expands rather straight into the bulk and the second one propagates along the interface at a lower speed; At a later stage, again unexpectedly, the first branched crack decelerates significantly in the bulk and the two cracks eventually merge into a single crack. The overall behavior is - in some sense - similar to that of the oblique shock and Prandtl- Meyer expansion waves in fluid mechanics, and it might give new insights not only into the question of high rupture speeds of natural earthquakes but also into the generation mechanism of tsunamis. u.ac.jp/~uenishi/

  4. Probabilistic simulation of uncertainties in composite uniaxial strengths

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Stock, T. A.

    1990-01-01

    Probabilistic composite micromechanics methods are developed that simulate uncertainties in unidirectional fiber composite strengths. These methods are in the form of computational procedures using composite mechanics with Monte Carlo simulation. The variables for which uncertainties are accounted include constituent strengths and their respective scatter. A graphite/epoxy unidirectional composite (ply) is studied to illustrate the procedure and its effectiveness to formally estimate the probable scatter in the composite uniaxial strengths. The results show that ply longitudinal tensile and compressive, transverse compressive and intralaminar shear strengths are not sensitive to single fiber anomalies (breaks, intergacial disbonds, matrix microcracks); however, the ply transverse tensile strength is.

  5. Metrics for comparing dynamic earthquake rupture simulations

    USGS Publications Warehouse

    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.

  6. Transverse gravity versus observations

    SciTech Connect

    Álvarez, Enrique; Faedo, Antón F.; López-Villarejo, J.J. E-mail: anton.fernandez@uam.es

    2009-07-01

    Theories of gravity invariant under those diffeomorphisms generated by transverse vectors, ?{sub ?}?{sup ?} = 0 are considered. Such theories are dubbed transverse, and differ from General Relativity in that the determinant of the metric, g, is a transverse scalar. We comment on diverse ways in which these models can be constrained using a variety of observations. Generically, an additional scalar degree of freedom mediates the interaction, so the usual constraints on scalar-tensor theories have to be imposed. If the purely gravitational part is Einstein-Hilbert but the matter action is transverse, the models predict that the three a priori different concepts of mass (gravitational active and gravitational passive as well as inertial) are not equivalent anymore. These transverse deviations from General Relativity are therefore tightly constrained, actually correlated with existing bounds on violations of the equivalence principle, local violations of Newton's third law and/or violation of Local Position Invariance.

  7. Transverse freezing of thin liquid films

    NASA Astrophysics Data System (ADS)

    Beerman, Michael

    A pair of coupled non-linear partial differential equations is derived using lubrication theory that govern the morphology of a thin, liquid film of a pure and a binary metal alloy, bounded by the liquid's solid phase and a passive gas phase. The analysis is motivated by the directional freezing of metallic foams, and is a first attempt to model transverse freezing in thin films that form in foam networks, but also applies to thin film layers in general. Both the no-slip crystal-melt and the free melt-gas interfaces are deformable. The governing pair of non-linear differential equations for the most general case incorporate crystal-melt and melt-gas surface tension, latent heat, heat transfer, volume change, molecular interactions, thermocapillary and dilute phase concentration effects. Linear analysis of a uniform film reveals a variety of instabilities. A unique wavenumber is selected at the onset of instability in the case of an applied temperature gradient with vanishing crystal-melt surface tension. This system reproduces the isothermal result for a rigid solid-liquid interface in which a band of wavenumbers is unstable. A new long-wave instability has been identified, for the case with CM surface tension, that is due to the coupling of the interfaces. Numerical solutions of the fully non-linear system provide film evolution and rupture times, and show that, near the critical conditions, rupture can occur by the growth of standing or traveling waves. The numerics also reveals complex non-linear interactions between unstable modes. It is found that for most unstable initial conditions, the crystal-melt interface retreats by melting away from the tip region of the encroaching melt-gas interface due to a rise in heat flux as the film thins near the rupture point.

  8. Fault barriers favor activation of backthrusts near segment ends of megathrust ruptures

    NASA Astrophysics Data System (ADS)

    Xu, S.; Fukuyama, E.; Ben-Zion, Y.; Ampuero, J. P.

    2013-12-01

    Increasing evidence indicates that backthrusts may become active during or after megathrust ruptures in subduction zones, such as in Chile and Sumatra areas (Melnick et al., 2012; Singh et al., 2011). Previous studies on relevant mechanisms mainly focused on the interaction between forethrusts and the megathrust. Here we aim to investigate through dynamic rupture simulations how backthrusts may be activated by megathrust ruptures in subduction zone environment. Assuming a single backthrust branch, our preliminary results show that the activation of backthrust is difficult if the megathrust rupture can easily pass through the fault junction, owing to a quickly established stress shadow zone in the wake of the megathrust rupture front. In contrast, if the megathrust rupture is arrested or delayed around the junction, a resultant backward stress lobe of the type discussed by Xu and Ben-Zion (2013) can load the backthrust over a considerable amount of time and facilitates rupture activation along the backthrust. A number of candidates can serve to arrest or delay megathrust ruptures, such as the velocity-strengthening frictional behavior and off-fault weak materials in the shallow portion of subduction zones, fault bend or ramp, and subducted seamount. Moreover, these features are also found capable of generating backthrusts during the long-term quasi-static process, which provide pre-existing weakness to be reactivated by later dynamic ruptures. Our results agree, from a different point of view, with the study based on the critical taper theory (Cubas et al., 2013) that an increase of friction towards the trench favors the activation of backthrusts near the up-dip limit of megathrust ruptures. The results highlight the role of fault geometric or strength heterogeneities in controlling the strain partitioning on and off the main fault plane. Accordingly, activated backthrusts may be treated as markers that reflect the limits of seismogenic zones, and thus may be used to characterize segmentation of subduction zones. Backthrusts can contribute, like forethrusts, to local tsunami generation, intra-plate seismicity, etc., and should be examined in further detail in future studies.

  9. Tensile and stress-rupture behavior of hafnium carbide dispersed molybdenum and tungsten base alloy wires

    NASA Technical Reports Server (NTRS)

    Yun, Hee Mann; Titran, Robert H.

    1993-01-01

    The tensile strain rate sensitivity and the stress-rupture strength of Mo-base and W-base alloy wires, 380 microns in diameter, were determined over the temperature range from 1200 K to 1600 K. Three molybdenum alloy wires; Mo + 1.1w/o hafnium carbide (MoHfC), Mo + 25w/o W + 1.1w/o hafnium carbide (MoHfC+25W) and Mo + 45w/o W + 1.1w/o hafnium carbide (MoHfC+45W), and a W + 0.4w/o hafnium carbide (WHfC) tungsten alloy wire were evaluated. The tensile strength of all wires studied was found to have a positive strain rate sensitivity. The strain rate dependency increased with increasing temperature and is associated with grain broadening of the initial fibrous structures. The hafnium carbide dispersed W-base and Mo-base alloys have superior tensile and stress-rupture properties than those without HfC. On a density compensated basis the MoHfC wires exhibit superior tensile and stress-rupture strengths to the WHfC wires up to approximately 1400 K. Addition of tungsten in the Mo-alloy wires was found to increase the long-term stress rupture strength at temperatures above 1400 K. Theoretical calculations indicate that the strength and ductility advantage of the HfC dispersed alloy wires is due to the resistance to recrystallization imparted by the dispersoid.

  10. Transverse instability of dunes.

    PubMed

    Parteli, Eric J R; Andrade, José S; Herrmann, Hans J

    2011-10-28

    The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show, by means of numerical simulations, that transverse dunes are unstable with respect to along-axis perturbations in their profile and decay on the bedrock into barchan dunes. Any forcing modulation amplifies exponentially with growth rate determined by the dune turnover time. We estimate the distance covered by a transverse dune before fully decaying into barchans and identify the patterns produced by different types of perturbation. PMID:22107675

  11. Transverse instability of dunes

    E-print Network

    Eric J. R. Parteli; José S. Andrade Jr.; Hans J. Herrmann

    2011-09-22

    The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show numerically and with a linear stability analysis that transverse dunes are unstable with respect to along-axis perturbations in their profile and decay on the bedrock into barchan dunes. Any forcing modulation amplifies exponentially with growth rate determined by the dune turnover time. We estimate the distance covered by a transverse dune before fully decaying into barchans and identify the patterns produced by different types of perturbation.

  12. Transverse Instability of Dunes

    NASA Astrophysics Data System (ADS)

    Parteli, Eric J. R.; Andrade, José S., Jr.; Herrmann, Hans J.

    2011-10-01

    The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show, by means of numerical simulations, that transverse dunes are unstable with respect to along-axis perturbations in their profile and decay on the bedrock into barchan dunes. Any forcing modulation amplifies exponentially with growth rate determined by the dune turnover time. We estimate the distance covered by a transverse dune before fully decaying into barchans and identify the patterns produced by different types of perturbation.

  13. [Left Ventricular Rupture following Mitral Valve Replacement].

    PubMed

    Yamaguchi, Atsushi

    2015-07-01

    Left ventricular rupture is a rare but lethal complication after mitral valve replacement (MVR). Between 1989 and 2014, of 850 patients who underwent MVR, 6 developed left ventricular rupture in Saitama Medical Center, Jichi Medical University. Treasure type I rupture occurred in 5 patients and Miller type III in 1. Four cases developed ventricular rupture right after declamping of the ascending aorta, and the remaining 2 after the transfer to the intensive care unit( ICU). Prompt surgical therapy was achieved for the instant closure of the muscular wall defect under the cardiopulmonary bypass and cardiac arrest, however, leading to the disappointing result of 66.7% of hospital death. It is the most important to relieving the stress of the posterior wall of the left ventricle during mitral surgery by using the modification techniques with the preservation of posterior mitral leaflet and avoiding pre and afterload of the left ventricle right after the MVR. PMID:26197900

  14. Speed of fast and slow rupture fronts along frictional interfaces

    NASA Astrophysics Data System (ADS)

    Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Thøgersen, Kjetil; Scheibert, Julien; Malthe-Sørenssen, Anders

    2015-07-01

    The transition from stick to slip at a dry frictional interface occurs through the breaking of microjunctions between the two contacting surfaces. Typically, interactions between junctions through the bulk lead to rupture fronts propagating from weak and/or highly stressed regions, whose junctions break first. Experiments find rupture fronts ranging from quasistatic fronts, via fronts much slower than elastic wave speeds, to fronts faster than the shear wave speed. The mechanisms behind and selection between these fronts are still imperfectly understood. Here we perform simulations in an elastic two-dimensional spring-block model where the frictional interaction between each interfacial block and the substrate arises from a set of junctions modeled explicitly. We find that material slip speed and rupture front speed are proportional across the full range of front speeds we observe. We revisit a mechanism for slow slip in the model and demonstrate that fast slip and fast fronts have a different, inertial origin. We highlight the long transients in front speed even along homogeneous interfaces, and we study how both the local shear to normal stress ratio and the local strength are involved in the selection of front type and front speed. Last, we introduce an experimentally accessible integrated measure of block slip history, the Gini coefficient, and demonstrate that in the model it is a good predictor of the history-dependent local static friction coefficient of the interface. These results will contribute both to building a physically based classification of the various types of fronts and to identifying the important mechanisms involved in the selection of their propagation speed.

  15. Speed of fast and slow rupture fronts along frictional interfaces.

    PubMed

    Trømborg, Jørgen Kjoshagen; Sveinsson, Henrik Andersen; Thøgersen, Kjetil; Scheibert, Julien; Malthe-Sørenssen, Anders

    2015-07-01

    The transition from stick to slip at a dry frictional interface occurs through the breaking of microjunctions between the two contacting surfaces. Typically, interactions between junctions through the bulk lead to rupture fronts propagating from weak and/or highly stressed regions, whose junctions break first. Experiments find rupture fronts ranging from quasistatic fronts, via fronts much slower than elastic wave speeds, to fronts faster than the shear wave speed. The mechanisms behind and selection between these fronts are still imperfectly understood. Here we perform simulations in an elastic two-dimensional spring-block model where the frictional interaction between each interfacial block and the substrate arises from a set of junctions modeled explicitly. We find that material slip speed and rupture front speed are proportional across the full range of front speeds we observe. We revisit a mechanism for slow slip in the model and demonstrate that fast slip and fast fronts have a different, inertial origin. We highlight the long transients in front speed even along homogeneous interfaces, and we study how both the local shear to normal stress ratio and the local strength are involved in the selection of front type and front speed. Last, we introduce an experimentally accessible integrated measure of block slip history, the Gini coefficient, and demonstrate that in the model it is a good predictor of the history-dependent local static friction coefficient of the interface. These results will contribute both to building a physically based classification of the various types of fronts and to identifying the important mechanisms involved in the selection of their propagation speed. PMID:26274187

  16. Investigation of Stress Rupture Tested Neutron Irradiated Tantalum Alloys

    NASA Astrophysics Data System (ADS)

    Barklay, Chadwick D.; Howe, Jane Y.; Kramer, Daniel P.

    2008-01-01

    Irradiation of metals with high-energy particles produces nano-scale defects that act as obstacles to dislocation glide. This paper presents the effects of low-level neutron radiation on the stress rupture and microstructural properties of two tantalum alloys, Ta-10%W and Ta-8%W-2%Hf (T-111), which have been used to encapsulate radioactive fuel for space Radioisotope Power Systems (RPS). Ta-10%W and T-111 test specimens were exposed to a neutron fluence level (1.2×1015nvt) at temperatures less than <0.2 Tm, which is equivalent to the cumulative fluence associated with the 30-year mission life of a RPS. This fluence level results in an atomic displacement damage of approximately 3.0×10-7 dpa in both alloys. The atomic displacement damage produces an approximate two-order of magnitude increase in the stress rupture time, and a two-order of magnitude reduction in steady state creep rate. These observations are statistically significant at the 0.05 significance level. Transmission electron microscopy of rupture specimens reveals that the interaction of the irradiation produced defects with ao/2<111> screw dislocations results in a five-fold increase in dislocation density and a pronouncement of the ordering of dislocations into mosaic patterns of cellular or subgranular arrangements. The results of this research are significant because they provide a basic understanding of the strength mechanisms in two tantalum alloys (Ta-10%W and T-111) resulting from neutron irradiation at temperatures <0.2 Tm.

  17. Creep-rupture behavior of candidate Stirling engine alloys after long-term aging at 760 deg C in low-pressure hydrogen

    NASA Technical Reports Server (NTRS)

    Titran, R. H.

    1984-01-01

    Nine candidate Stirling automotive engine alloys were aged at 760 C for 3500 hr in low pressure hydrogen or argon to determine the resulting effects on mechanical behavior. Candidate heater head tube alloys were CG-27, W545, 12RN72, INCONEL-718, and HS-188 while candidate cast cylinder-regenerator housing alloys were SA-F11, CRM-6D, XF-818, and HS-31. Aging per se is detrimental to the creep rupture and tensile strengths of the iron base alloys. The presence of hydrogen does not significantly contribute to strength degradation. Based percent highway driving cycle; CG-27 has adequate 3500 hr - 870 C creep rupture strength and SA-Fll, CRM-6D, and XF-818 have adequate 3500 hr - 775 C creep rupture strength.

  18. Effect of rolling on the high temperature tensile and stress-rupture properties of tungsten fiber-superalloy composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.

    1974-01-01

    An investigation was conducted to determine the effects of mechanical working on the 1093 C (2000 F) tensile and stress-rupture strength of tungsten alloy/superalloy composites. Hot pressed composites containing either conventional tungsten lamp filament wire or tungsten-1% ThO2 wire and a nickel base alloy matrix were hot rolled at 1093 C (2000 F). The hot pressed and rolled composite specimens were then tested in tension and stress-rupture at 1093 C (2000 F). Rolling decreased the degree of fiber-matrix reaction as a function of time of exposure at 1093 C (2000 F). The stress-rupture properties of the rolled composites were superior to hot pressed composites containing equivalent diameter fibers. Rolling did not appreciably affect the 1093 C (2000 F) ultimate tensile strength of the composites.

  19. Effect of rolling on the high temperature tensile and stress-rupture properties of tungsten fiber-superalloy composites

    NASA Technical Reports Server (NTRS)

    Petrasek, D. W.

    1974-01-01

    An investigation was conducted to determine the effects of mechanical working on the 1093 C tensile and stress-rupture strength of tungsten alloy/superalloy composites. Hot pressed composites containing either conventional tungsten lamp filament wire or tungsten-1% ThO2 wire and a nickel base alloy matrix were hot rolled at 1093 C. The hot pressed and rolled composite specimens were then tested in tension and stress-rupture at 1093 C. Rolling decreased the degree of fiber-matrix reaction as a function of time of exposure at 1093 C. The stress-rupture properties of the rolled composites were superior to hot pressed composites containing equivalent diameter fibers. Rolling did not appreciably affect the 1093 C ultimate tensile strength of the composites.

  20. Expanding Endovascular Therapy of Very Small Ruptured Aneurysms with the 1.5-mm Coil

    PubMed Central

    Nguyen, Thanh N.; Masoud, Hesham; Tarlov, Nicholas; Holsapple, James; Chin, Lawrence S.; Norbash, Alexander M.

    2015-01-01

    Background Very small ruptured aneurysms (?3 mm) demonstrate a significant risk for procedural rupture with endovascular therapy. Since 2007, 1.5-mm-diameter coils have been available (Micrus, Microvention, and ev3), allowing neurointerventionalists the opportunity to offer patients with very small aneurysms endovascular treatment. In this study, we review the clinical and angiographic outcome of patients with very small ruptured aneurysms treated with the 1.5-mm coil. Methods This is a retrospective cohort study in which we examined consecutive ruptured very small aneurysms treated with coil embolization at a single institution. The longest linear aneurysm was recorded, even if the first coil was sized to a smaller transverse diameter. Very small aneurysms were defined as ?3 mm. Descriptive results are presented. Results From July 2007 to March 2015, 81 aneurysms were treated acutely with coils in 78 patients presenting with subarachnoid hemorrhage. There were 5 patients with 3-mm aneurysms, of which the transverse diameter was ?2 mm in 3 patients. In all 5 patients, a balloon was placed for hemostatic prophylaxis in case of rupture, and a single 1.5-mm coil was inserted for aneurysm treatment without complication. Complete aneurysm occlusion was achieved in 1 patient, residual neck in 2, and residual aneurysm in 2 patients. Aneurysm recanalization was present in 2 patients with an anterior communicating artery aneurysm; a recoiling attempt was unsuccessful in 1 of these 2 patients due to inadvertent displacement and distal coil embolization, but subsequent surgical clipping was successful. Another patient was retreated by surgical clipping for a residual wide-neck carotid terminus aneurysm. One patient died of ventriculitis 3 weeks after presentation; all 4 other patients had an excellent outcome with no rebleed at follow-up (mean 21 months, range 1-62). Conclusion The advent of the 1.5-mm coil may be used in the endovascular treatment of patients with very small ruptured aneurysms, providing a temporary protection to the site of rupture in the acute phase. If necessary, bridging with elective clipping may provide definitive aneurysm treatment. PMID:26600799

  1. Effect of simulated medium-Btu coal gasifier atmospheres on the biaxial stress rupture behavior of four candidate coal gasifier alloys

    SciTech Connect

    Horton, R.M.; Smolik, G.R.

    1982-01-01

    Tests were conducted to determine whether the biaxial stress rupture behavior of four alloys was adversely affected by exposure to four simulated medium-Btu coal gasifier atmospheres. The results of exposures up to approximately 500 h at temperatures between 649 and 982/sup 0/C are presented. Exposure to these atmospheres at temperatures below 900/sup 0/C did not significantly reduce the rupture properties from those measured in air. Only at 982/sup 0/C were the rupture strength and life in the simulated coal gasifier atmospheres lower than those measured in air at atmospheric pressure. Possible reasons for this reduction in strength/life are discussed. The results of detailed examination of specimen ruptures are also presented.

  2. Tensile and creep rupture properties of (16) uncoated and (2) coated engineering alloys at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Fritz, L. J.; Koster, W. P.

    1977-01-01

    Sixteen test materials were supplied by NASA-Lewis Research Center as wrought bar or cast remelt stock. The cast remelt stock was cast into test blanks with two such materials being also evaluated after Jocoat coating was applied. Mechanical properties evaluated included tensile, modulus of elasticity, Poisson's Ratio, creep properties and creep rupture strength. Tests were conducted at temperatures applicable to the service temperature of the various alloys. This range extended from room temperature to 1000 C.

  3. Surgical Strategies for Acutely Ruptured Arteriovenous Malformations.

    PubMed

    Martinez, Jaime L; Macdonald, R Loch

    2015-11-01

    Brain arteriovenous malformations (AVMs) are focal neurovascular lesions consisting of abnormal fistulous connections between the arterial and venous systems with no interposed capillaries. This arrangement creates a high-flow circulatory shunt with hemorrhagic risk and hemodynamic abnormalities. While most AVMs are asymptomatic, they may cause severe neurological complications and death. Each AVM carries an annual rupture risk of 2-4%. Intracranial hemorrhage due to AVM rupture is the most common initial manifestation (up to 70% of presentations), and it carries significant morbidity and mortality. This complication is particularly important in the young and otherwise healthy population, in whom AVMs cause up to one-third of all hemorrhagic strokes. A previous rupture is the single most important independent predictor of future hemorrhage. Current treatment modalities for AVM are microsurgery, endovascular embolization, and radiosurgery. In acutely ruptured AVMs, early microsurgical excision is usually avoided. The standard is to wait at least 4 weeks to allow for patient recovery, hematoma liquefaction, and inflammatory reactions to subside. Exceptions to this rule are small, superficial, low-grade AVMs with elucidated angioarchitecture, for which early simultaneous hematoma evacuation and AVM excision is feasible. Emergent hematoma evacuation with delayed AVM excision (unless, as mentioned, the AVM is low grade) is recommended in patients with a decreased level of consciousness due to intracranial hemorrhage, posterior fossa or temporal lobe hematoma of >30 ml, or hemispheric hematoma of >60 ml. The applicability of endovascular techniques for acutely ruptured AVMs is not clear, but feasible options, until a definitive treatment is determined, include occluding intranidal and distal flow-related aneurysms and 'sealing' any rupture site or focal angioarchitectural weakness when one can be clearly identified and safely accessed. Radiosurgery is not performed in acutely ruptured AVMs because its therapeutic effects occur in a delayed fashion. PMID:26587641

  4. Rupture Process for Hayward Microearthquakes Inferred from Borehole Seismic Recordings

    NASA Astrophysics Data System (ADS)

    Taira, T.; Dreger, D. S.; Nadeau, R. M.

    2014-12-01

    The Hayward fault (HF) in the San Francisco Bay Area, California is one of the major strands of the San Andreas fault system, extending for about 70 km. Crustal deformation along the HF is characterized by a wide variety of fault slip behaviors from aseismic creep to stick-slip earthquake including a Mw ~6.8 earthquake in 1868. We here document the high-resolution imaging of the rupture models for the recent M 3+ HF earthquakes by making use of waveforms from the Hayward Fault Network (HFN). The HFN is an array of borehole seismic instrumentation and provides an unprecedented high-resolution coverage of the earthquake source study for HF earthquakes. Using the finite-source rupture inversion with an empirical Green's function approach, we find a variety of rupture propagations including subevents, directivity, and high stress drop. Our finite-source modeling reveals a complex slip distribution for the 2013 Mw 3.2 Orinda earthquake that is characterized by a patch of slip with a maximum slip of 4 cm concentrated near the hypocenter at about 6.6 km depth, with a large secondary patch of slip (peak slip of 2 cm) centered up-dip and southeast from the hypocenter at a distance of about 400 m away. The two subevents release 43% and 23% of the total seismic moment (6.7 x 1013 N m) and the inferred peak stress drops are 18 MPa and 10 MPa. The 2011 Mw 4.0 Berkeley and 2012 Mw 4.0 El Cerrito earthquakes are marked by high stress drop. The inferred peak and mean stress drops are about 130-165 MPa and 45 MPa, respectively, which suggests that there are locally high levels of the fault strength on the HF. Our finite-source modeling suggests that the radiation efficiency determined for these two earthquakes is very low (< 0.1) and implies that majority of energy is dissipated during the earthquake rupture process.

  5. Effect of stress state on slow rupture propagation in synthetic fault gouges

    NASA Astrophysics Data System (ADS)

    Hirauchi, Ken-ichi; Muto, Jun

    2015-12-01

    Slow slip events (SSEs) in subduction zones are known to proceed so sluggishly that the associated slow ruptures do not generate any detectable radiating seismic waves. Moreover, they propagate at speeds at least four orders of magnitude slower than regular earthquakes. However, the underlying physics of slow slip generation has yet to be understood. Here, we carry out laboratory studies of unstable slip along simulated fault zones of lizardite/chrysotile (liz/ctl) and antigorite (i.e., low- and high-temperature serpentine phases, respectively) and olivine, under varying conditions of normal stress, with the aim of better understanding the influence of stress state on the process of slow rupture along the plate interface. During a single unstable slip, we clearly observe a slow rupture phase that is often followed by an unstable, high-speed rupture. We find that lower fault-zone friction coefficients (? values from 0.7 down to 0.5) lead to increasing degree of the slow rupture mode, and also that the slow rupture velocities ( V r = 0.07 to 5.43 m/s) are largely consistent with those of short-term SSEs observed in nature. Our findings suggest that the generation of SSEs is facilitated by conditions of low normal stress and low fault-zone strength along the plate interface, which may be weakened by metamorphic reactions that result in the production of hydrous phases (e.g., serpentine) and/or the direct involvement of fluid itself, leading to a reduction in effective normal stress.

  6. Results of accelerated postoperative rehabilitation using novel "suture frame" repair of Achilles tendon rupture.

    PubMed

    Talbot, Joseph C; Williams, Gary T; Bismil, Quamar; Shaw, David L; Schilders, Ernest

    2012-01-01

    The management of Achilles tendon rupture is a much-debated subject. In recent years, there has been much interest in early postoperative mobilization. We present the results of our Achilles tendon repair technique and accelerated rehabilitation program. The technique we propose uses the strength of a 1-loop polydioxanone "suture frame" to enable restoration of the tendon length, immediate positioning of the foot in a near-plantigrade position, and an accelerated rehabilitation program. We followed up 15 cases of Achilles tendon rupture treated with this technique. The initial follow-up was a review of case notes and a telephone questionnaire. All patients were subsequently invited for a clinical follow-up visit, and 11 patients (68.75%) attended. No cases of infection or repeat rupture occurred. The return to work (mean 5.6 weeks) and return to sport (mean 4.8 months) were relatively rapid. Regarding overall satisfaction on a scale of 0 to 10, the median was 9 (range 8 to 10). Of the 11 patients who attended the clinical follow-up visit, the mean American Orthopaedic Foot and Ankle Surgery ankle-hindfoot score was 94.5 points (range 83 to 100). The Achilles rupture repair scores (including isokinetic muscle strength) were good or excellent in all but 1 patient, whose result was fair. Of the 11 patients, 10 reported complete satisfaction with their outcome. Our technique with accelerated rehabilitation is safe and effective in the management of acute Achilles tendon rupture. It facilitates an early return to work and recreational sports, with excellent overall patient satisfaction. PMID:22153660

  7. Acute abdomen caused by bladder rupture attributable to neurogenic bladder dysfunction following a stroke: a case report

    PubMed Central

    2011-01-01

    Introduction Spontaneous bladder rupture is a rare and serious event with high mortality. It is not often considered in the patient presenting with peritonitis. This often leads to delays in diagnosis. There are very few case reports of true spontaneous rupture in the literature. This is the first such reported case in which bladder rupture was attributable to neurogenic bladder dysfunction following a stroke. Case presentation We report the case of a 67-year-old Caucasian man who presented with lower abdominal pain and a peritonitic abdomen. He had a long-term urethral catheter because of urinary retention following a previous stroke. He was treated conservatively with antibiotics before a surgical opinion was sought. Exploratory laparotomy confirmed the diagnosis of spontaneous bladder rupture. After repair of the defect, he eventually made a full recovery. Conclusion In this unusual case report, we describe an example of a serious event in which delays in diagnosis may lead to increased morbidity and mortality. To date, no unifying theory explaining why rupture occurs has been postulated. We conducted a thorough literature search to examine the etiological factors in other published cases. These etiological factors either increase intra-vesical pressure or decrease the strength of the bladder wall. We hope that by increasing awareness of these etiological factors, spontaneous bladder rupture may be diagnosed earlier and appropriate therapy started. PMID:21714888

  8. Characteristics of thermally-induced transverse cracks in graphite epoxy composite laminates

    NASA Technical Reports Server (NTRS)

    Adams, D. S.; Bowles, D. E.; Herakovich, C. T.

    1983-01-01

    The characteristics of thermally induced transverse cracks in T300/5208 graphite-epoxy cross-ply and quasi-isotropic laminates were investigated both experimentally and analytically. The formation of transverse cracks and the subsequent crack spacing present during cool down to -250 F (116K) and thermal cycling between 250 and -250 F (116 and 394K) was investigated. The state of stress in the vicinity of a transverse crack and the influence of transverse cracking on the laminate coefficient of thermal expansion (CTE) was predicted using a generalized plane strain finite element analysis and a modified shear lag analysis. A majority of the cross-ply laminates experienced transverse cracking during the initial cool down to -250 F whereas the quasi-isotropic laminates remained uncracked. The in situ transverse strength of the 90 degree layers was more than 1.9 times greater than the transverse strength of the unidirectional 90 degree material for all laminates investigated.

  9. Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

    PubMed

    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. PMID:25577259

  10. Transverse Charge Densities

    E-print Network

    Gerald A. Miller

    2010-02-01

    Electromagnetic form factors have long been used to probe the underlying charge and magnetization densities of hadrons and nuclei. Traditional three-dimensional Fourier transform methods are not rigorously applicable for systems with constituents that move relativistically. The use of the transverse charge density is a new, rigorously defined way to analyze electromagnetic form factors of hadrons.This review is concerned with the following issues: what is a transverse charge density; how is one extracted one from elastic scattering data; the existing results; what is the relationship with other observable quantities; and, future prospects.

  11. Time/Temperature Dependent Tensile Strength of SiC and Al2O3-Based Fibers

    NASA Technical Reports Server (NTRS)

    Yun, Hee Mann; DiCarlo, James A.

    1997-01-01

    In order to understand and model the thermomechanical behavior of fiber-reinforced composites, stress-rupture, fast-fracture, and warm-up rupture studies were conducted on various advanced SiC and Al2O3-based fibers in the,temperature range from 20 to 1400 C in air as well as in inert environments. The measured stress-rupture, fast fracture, and warm-up rupture strengths were correlated into a single master time/temperature-dependent strength plot for each fiber type using thermal activation and slow crack growth theories. It is shown that these plots are useful for comparing and selecting fibers for CMC and MMC reinforcement and that, in comparison to stress rupture tests, the fast-fracture and warm-up tests can be used for rapid generation of these plots.

  12. Scaling in rupture of polymer chains

    E-print Network

    S. Fugmann; I. M. Sokolov

    2008-07-18

    We consider the rupture dynamics of a homopolymer chain pulled at one end at a constant loading rate r. Compared to single bond breaking, the existence of the chain introduces two new aspects into rupture dynamics: the non-Markovian aspect in the barrier crossing and the slow-down of the force propagation to the breakable bond. The relative impact of both these processes is investigated, and the second one was found to be the most important at moderate loading rates. The most probable rupture force is found to decrease with the number of bonds as f_{max} const-(ln(N/r))^(2/3) and finally to approach a saturation value independent on N. All our analytical findings are confirmed by extensive numerical simulations.

  13. On the rupture of DNA molecule

    NASA Astrophysics Data System (ADS)

    Mishra, R. K.; Modi, T.; Giri, D.; Kumar, S.

    2015-05-01

    Using Langevin dynamics simulations, we study effects of the shear force on the rupture of a double stranded DNA molecule. The model studied here contains two single diblock copolymers interacting with each other. The elastic constants of individual segments of diblock copolymer are considered to be different. We showed that the magnitude of the rupture force depends on whether the force is applied at 3' - 3' - ends or 5' - 5' - ends. Distributions of extension in hydrogen bonds and covalent bonds along the chain show the striking differences. Motivated by recent experiments, we have also calculated the variation of rupture force for different chain lengths. Results obtained from simulations have been validated with the analytical calculation based on the ladder model of DNA.

  14. On the rupture of DNA molecule

    E-print Network

    R. K. Mishra; T. Modi; D. Giri; S. Kumar

    2015-07-01

    Using Langevin Dynamic simulations, we study effects of the shear force on the rupture of a double stranded DNA molecule. The model studied here contains two single diblock copolymers interacting with each other. The elastic constants of individual segments of the diblock copolymer are considered to be different. We showed that the magnitude of the rupture force depends on whether the force is applied at $3'-3'-$ends or $5'-5'-$ends. Distributions of extension in hydrogen bonds and covalent bonds along the chain show the striking differences. Motivated by recent experiments, we have also calculated the variation of rupture force for different chain lengths. Results obtained from simulations have been validated with the analytical calculation based on the ladder model of DNA.

  15. Large-Scale Weibull Analysis of H-451 Nuclear- Grade Graphite Specimen Rupture Data

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Walker, Andrew; Baker, Eric H.; Murthy, Pappu L.; Bratton, Robert L.

    2012-01-01

    A Weibull analysis was performed of the strength distribution and size effects for 2000 specimens of H-451 nuclear-grade graphite. The data, generated elsewhere, measured the tensile and four-point-flexure room-temperature rupture strength of specimens excised from a single extruded graphite log. Strength variation was compared with specimen location, size, and orientation relative to the parent body. In our study, data were progressively and extensively pooled into larger data sets to discriminate overall trends from local variations and to investigate the strength distribution. The CARES/Life and WeibPar codes were used to investigate issues regarding the size effect, Weibull parameter consistency, and nonlinear stress-strain response. Overall, the Weibull distribution described the behavior of the pooled data very well. However, the issue regarding the smaller-than-expected size effect remained. This exercise illustrated that a conservative approach using a two-parameter Weibull distribution is best for designing graphite components with low probability of failure for the in-core structures in the proposed Generation IV (Gen IV) high-temperature gas-cooled nuclear reactors. This exercise also demonstrated the continuing need to better understand the mechanisms driving stochastic strength response. Extensive appendixes are provided with this report to show all aspects of the rupture data and analytical results.

  16. Prognostic factors of spontaneously ruptured hepatocellular carcinoma

    PubMed Central

    Han, Xiang-Jun; Su, Hong-Ying; Shao, Hai-Bo; Xu, Ke

    2015-01-01

    AIM: To evaluate the prognostic factors in patients with spontaneously ruptured hepatocellular carcinoma (HCC). METHODS: Seventy-nine patients experiencing spontaneous rupture of HCC between April 2004 and August 2014 were enrolled in this study. The clinical features, treatment modalities and outcomes were reviewed. The statistical methods used in this work included univariate analysis, Kaplan-Meier survival analysis with log-rank tests, and multivariate analysis using a Cox regression hazard model. RESULTS: Of the 79 patients with HCC rupture, 17 (21.5%) underwent surgery, 32 (40.5%) underwent transarterial embolization (TAE), and 30 (38%) received conservative treatment. The median survival time was 125 d, and the mortality rate at 30 d was 27.8%. Multivariate analysis revealed that lesion length (HR = 1.46, P < 0.001), lesion number (HR = 1.37, P = 0.042), treatment before tumor rupture (HR = 4.36, P = 0.019), alanine transaminase levels (HR = 1.0, P = 0.011), bicarbonate levels (HR = 1.18, P < 0.001), age (HR = 0.96, P = 0.026), anti-tumor therapy during the follow-up period (HR = 0.21, P = 0.008), and albumin levels (HR = 0.89, P = 0.010) were independent prognostic factors of survival after HCC rupture. The Barcelona-Clinic Liver Cancer (BCLC) stage was also an important prognostic factor; the median survival times for BCLC stages A, B and C were 251, 175 and 40 d, respectively (P < 0.001). CONCLUSION: Anti-tumor therapy during the follow-up period, without a history of anti-tumor therapy prior to HCC rupture, small tumor length and number, and early BCLC stage are the most crucial predictors associated with satisfactory overall survival. Other factors play only a small role in overall survival. PMID:26139994

  17. Shock wave theory for rupture of rubber

    E-print Network

    M. Marder

    2004-07-09

    This article presents a theory for the rupture of rubber. Unlike conventional cracks, ruptures in rubber travel faster than the speed of sound, and consist in two oblique shocks that meet at a point. Physical features of rubber needed for this phenomenon include Kelvin dissipation and an increase of toughness as rubber retracts. There are three levels of theoretical description: an approximate continuum theory, an exact analytical solution of a slightly simplified discrete problem, and numerical solution of realistic and fully nonlinear equations of motion.

  18. COMPARISON OF CLADDING CREEP RUPTURE MODELS

    SciTech Connect

    P. Macheret

    2000-06-12

    The objective of this calculation is to compare several creep rupture correlations for use in calculating creep strain accrued by the Zircaloy cladding of spent nuclear fuel when it has been emplaced in the repository. These correlations are used to calculate creep strain values that are then compared to a large set of experimentally measured creep strain data, taken from four different research articles, making it possible to determine the best fitting correlation. The scope of the calculation extends to six different creep rupture correlations.

  19. Thoracic Outlet Syndrome Following Breast Implant Rupture

    PubMed Central

    Caplash, Yugesh; Giri, Pratyush; Kearney, Daniel; Wagstaff, Marcus

    2015-01-01

    Summary: We present a patient with bilateral breast implant rupture who developed severe locoregional silicone granulomatous lymphadenopathy. Poly Implant Prothese silicone implants had been used for bilateral breast augmentation 5 years prior. Extracapsular implant rupture and bilateral axillary lymphadenopathy indicated explantation, capsulectomy, and selective lymph node excision. Histology demonstrated silicone lymphadenopathy with no evidence of malignancy. Over the subsequent 12 months, she developed progressive locoregional lymphadenopathy involving bilateral cervical, axillary, and internal mammary groups, resulting in bilateral thoracic outlet syndrome. We report the unusual presentation, progression, and the ultimate surgical management of this patient. PMID:25878942

  20. Spontaneous Achilles tendon rupture in alkaptonuria.

    PubMed

    Alajoulin, Omar A; Alsbou, Mohammed S; Ja'afreh, Somayya O; Kalbouneh, Heba M

    2015-12-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  1. Gastric rupture after bag-mask-ventilation

    PubMed Central

    Bednarz, Stephan; Filipovic, Miodrag; Schoch, Otto; Mauermann, Eckhard

    2015-01-01

    A 42 year old woman underwent bronchoscopy with procedural propofol sedation. During the procedure, the patient suffered respiratory arrest, and bag-mask ventilation was initiated. During forced mask ventilation, abdominal distention occurred. Even after correct placement of an endotracheal and a nasogastric tube, high inspiratory pressures persisted. The abdominal CT scan revealed a high amount of intraperitoneal free air. An emergent laparotomy confirmed a stomach rupture. Immediately after opening of the peritoneal cavity, peak ventilatory pressures decreased. In this case forceful bag-mask ventilation led to air insufflation into the stomach, increasing gastric pressure, and consecutive stomach rupture.

  2. Pectoralis major tendon rupture. Surgical procedures review.

    PubMed Central

    Merolla, Giovanni; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

    2012-01-01

    Summary Pectoralis major (PM) muscle is the powerful dynamic stabiliser of the shoulder that acts as a flexor, adductor and internal rotator. The rupture of the PM tendon is a relatively rare injury that was firstly described in a French boy by Patissier in 1822 and later, in 1861, by Letenneur who reported another similiar case. To date, over 200 cases have been published. In this article we describe the clinical anatomy and the mechanism of injuries of PM and we review the surgical procedures for acute and chronic ruptures. PMID:23738281

  3. Rupture energy of a pendular liquid bridge

    NASA Astrophysics Data System (ADS)

    Pitois, O.; Moucheront, P.; Chateau, X.

    2001-09-01

    We propose a simple expression for the rupture energy of a pendular liquid bridge between two spheres, taking into account capillary and viscous (lubrication) forces. In the case of capillary forces only, the results are in accordance with curve fitting expressions proposed by Simons et al. [2] and Willett et al. [5]. We performed accurate measurements of the force exerted by liquid bridges between two spheres. Experimental results are found to be close to theoretical values. A reasonable agreement is also found in the presence of viscous forces. Finally, for small bridge volumes, the rupture criterion given by Lian et al. [10] is modified, taking into account additional viscous effects.

  4. Mechanical properties of high-strength concrete

    NASA Astrophysics Data System (ADS)

    Mokhtarzadeh, Alireza

    This report summarizes an experimental program conducted to investigate production techniques and mechanical properties of high strength concrete in general and to provide recommendations for using these concretes in manufacturing precast/prestressed bridge girders. Test variables included total amount and composition of cementitious material (portland cement, fly ash, and silica fume), type and brand of cement, type of silica fume (dry densified and slurry), type and brand of high-range water-reducing admixture, type of aggregate, aggregate gradation, maximum aggregate size, and curing. Tests were conducted to determine the effects of these variables on changes in compressive strength and modulus of elasticity over time, splitting tensile strength, modulus of rupture, creep, shrinkage, and absorption potential (as an indirect indicator of permeability). Also investigated were the effects of test parameters such as mold size, mold material, and end condition. Over 6,300 specimens were cast from approximately 140 mixes over a period of 3 years.

  5. Deconstructed transverse mass variables

    NASA Astrophysics Data System (ADS)

    Ismail, Ahmed; Schwienhorst, Reinhard; Virzi, Joseph S.; Walker, Devin G. E.

    2015-04-01

    Traditional searches for R-parity conserving natural supersymmetry (SUSY) require large transverse mass and missing energy cuts to separate the signal from large backgrounds. SUSY models with compressed spectra inherently produce signal events with small amounts of missing energy that are hard to explore. We use this difficulty to motivate the construction of "deconstructed" transverse mass variables which are designed preserve information on both the norm and direction of the missing momentum. We demonstrate the effectiveness of these variables in searches for the pair production of supersymmetric top-quark partners which subsequently decay into a final state with an isolated lepton, jets and missing energy. We show that the use of deconstructed transverse mass variables extends the accessible compressed spectra parameter space beyond the region probed by traditional methods. The parameter space can further be expanded to neutralino masses that are larger than the difference between the stop and top masses. In addition, we also discuss how these variables allow for novel searches of single stop production, in order to directly probe unconstrained stealth stops in the small stop- and neutralino-mass regime. We also demonstrate the utility of these variables for generic gluino and stop searches in all-hadronic final states. Overall, we demonstrate that deconstructed transverse variables are essential to any search wanting to maximize signal separation from the background when the signal has undetected particles in the final state.

  6. [Papillary Muscle Rupture after Repair of Ischemic Left Ventricular Free Wall Rupture; Report of a Case].

    PubMed

    Kurumisawa, Soki; Kaminishi, Yuichirou; Akutsu, Hirohiko; Takazawa, Ippei; Aizawa, Kei; Misawa, Yoshio

    2015-11-01

    A 67-year-old man experienced acute inferior myocardial infarction. Echocardiography and computed tomography showed massive pericardial effusion. He underwent emergency operation for ischemic ventricular free wall rupture. During the operation, an oozing type rupture was found on the inferior wall and the bleeding was completely controlled by applying fibrin glue sheets. On the 5th day after the operation, ventricular tachycardia appeared with hemodynamic deterioration. Echocardiography showed a ruptured posteromedial papillary muscle with massive mitral regurgitation. Intra-aortic balloon pumping was introduced and emergency repair operation was performed. The mitral valve was replaced with a bioprosthetic valve. The postoperative course was uneventful. PMID:26555919

  7. Effect of Overheating on Creep-rupture Properties of S-816 Alloy at 1,500 F

    NASA Technical Reports Server (NTRS)

    Rowe, John P; Freeman, J W

    1957-01-01

    The effects of overheats to temperatures of 1650, 1800, 1900, and 2000 F were evaluated in terms of the changes in creep-rupture characteristics at 1500 F of S-816 alloy under stresses within the range of rupture strengths of the alloy for 100 to 1000 hours. Overheat periods were predominantly of 2-minute duration and were applied cyclically at approximately 5- or 12-hour intervals. The possible damage from overheating was believed to include internal metal structure changes induced by exposure to the higher temperatures and loss of life by creep if stress was present during the overheats.

  8. Effects of Thermal Treatment on Tensile Creep and Stress-Rupture Behavior of Hi-Nicalon SiC Fibers

    NASA Technical Reports Server (NTRS)

    Yun, H. M.; Goldsby, J. C.; Dicarlo, J. A.

    1995-01-01

    Tensile creep and stress-rupture studies were conducted on Hi-Nicalon SiC fibers at 1200 and 1400 C in argon and air. Examined were as-received fibers as well as fibers annealed from 1400 to 1800 C for 1 hour in argon before testing. The creep and rupture results for these annealed fibers were compared to those of the as-received fibers to determine the effects of annealing temperature, test temperature, and test environment. Argon anneals up to 1500 C degrade room temperature strength of Hi-Nicalon fibers, but improve fiber creep resistance in argon or air by as much as 100% with no significant degradation in rupture strength. Argon anneals above 1500 C continue to improve fiber creep resistance when tested in argon, but significantly degrade creep resistance and rupture strength when tested in air. Decrease in creep resistance in air is greater at 1200 C than at 1400 C. Mechanisms are suggested for the observed behavior.

  9. Primary gastric rupture in 47 horses (1995-2011).

    PubMed

    Winfield, Laramie S; Dechant, Julie E

    2015-09-01

    The purpose of this retrospective case-control study was to identify factors associated with primary gastric rupture and to investigate if there were differences between etiologies of primary gastric rupture. Compared to the general colic population, Quarter horses were under-represented and Friesians and draft breeds were over-represented in 47 cases of primary gastric ruptures. Horses with primary gastric rupture typically presented with severe clinical and clinicopathological derangements. There were 24 idiopathic gastric ruptures, 20 gastric impaction associated ruptures, and 3 perforating gastric ulcers. Thoroughbred horses were over-represented in the idiopathic gastric rupture group compared to other breeds and etiologies. This study suggests the presence of important breed predispositions for development of gastric rupture. Further study is necessary to identify if these predispositions are associated with management factors or breed-specific disorders. PMID:26345205

  10. Source rupture process of the 2011 Fukushima-ken Hamadori earthquake: how did the two subparallel faults rupture?

    NASA Astrophysics Data System (ADS)

    Tanaka, Miho; Asano, Kimiyuki; Iwata, Tomotaka; Kubo, Hisahiko

    2014-12-01

    The 2011 Fukushima-ken Hamadori earthquake (MW 6.6) occurred about a month after the 2011 Great Tohoku earthquake (MW 9.0), and it is thought to have been induced by the 2011 Tohoku earthquake. After the 2011 Hamadori earthquake, two subparallel faults (the Itozawa and Yunodake faults) were identified by field surveys. The hypocenter was located nearby the Itozawa fault, and it is probable that the Itozawa fault ruptured before the Yunodake fault rupture. Here, we estimated the source rupture process of the 2011 Hamadori earthquake using a model with two subparallel faults based on strong motion data. The rupture starting point and rupture delay time of the Yunodake fault were determined based on Akaike's Bayesian Information Criterion (ABIC). The results show that the Yunodake fault started to rupture from the northern deep point 4.5 s after the Itozawa fault started to rupture. The estimated slip distribution in the shallow part is consistent with the surface slip distribution identified by field surveys. Time-dependent Coulomb failure function changes (?CFF) were calculated using the stress change from the Itozawa fault rupture in order to evaluate the effect of the rupture on the Yunodake fault. The ?CFF is positive at the rupture starting point of the Yunodake fault 4.5 s after the Itozawa fault started to rupture; therefore, it is concluded that during the 2011 Hamadori earthquake, the Yunodake fault rupture was triggered by the Itozawa fault rupture.

  11. Characteristics of transverse waves in chromospheric mottles

    SciTech Connect

    Kuridze, D.; Mathioudakis, M.; Jess, D. B.; Keenan, F. P.; Verth, G.; Erdélyi, R.; Morton, R. J.; Christian, D. J.

    2013-12-10

    Using data obtained by the high temporal and spatial resolution Rapid Oscillations in the Solar Atmosphere instrument on the Dunn Solar Telescope, we investigate at an unprecedented level of detail transverse oscillations in chromospheric fine structures near the solar disk center. The oscillations are interpreted in terms of propagating and standing magnetohydrodynamic kink waves. Wave characteristics including the maximum transverse velocity amplitude and the phase speed are measured as a function of distance along the structure's length. Solar magnetoseismology is applied to these measured parameters to obtain diagnostic information on key plasma parameters (e.g., magnetic field, density, temperature, flow speed) of these localized waveguides. The magnetic field strength of the mottle along the ?2 Mm length is found to decrease by a factor of 12, while the local plasma density scale height is ?280 ± 80 km.

  12. Traumatic bladder rupture in a paratrooper.

    PubMed

    Ford, David; Palma, James; Robinson, John

    2009-06-01

    A paratrooper presents after a parachuting accident with the inability to urinate. Initial emergency bedside ultrasound, followed by confirmatory abdominal CT, is carried out and demonstrates an intraperitoneal bladder rupture. The patient is taken to the operating room and a 3-layer closure with omental buttressing is carried out. PMID:19585785

  13. Surface Rupture in Northwest Saudi Arabia

    USGS Multimedia Gallery

    Wendy McCausland of the USGS Volcano Disaster Assistance Program and Hani Zahran of the Saudi Geological Survey view the southern end of the surface fault rupture caused by a M5.4 earthquake in the Saudi Arabian desert on May 19, 2009. The ground displacements in the soft sediments of the foreground...

  14. D-Zero Cryostat Supplemental Rupture Disc

    SciTech Connect

    Mulholland, G.T.; /Fermilab

    1987-08-03

    The common relief and rupture disc vent line requires a double disc assembly with vented interspace for accurate disc burst pressures. The first disc must take pump and purge vacuum loading, but be set to operate at 110% of the MAWP, 18.3 psig (ASME code). The available solution is 18.3 psig with a burst tolerance of +/- psig. The interspace should be locally vented by a flow limiting vent valve to decouple the vent line backpressure from the vessel rupture disc. The second disc must take the worst case vent line backpressure, the steady state value found in D-Zero engineering note 3740.000-EN-63 with all three cryostats simultaneously venting at the fire condition into the 4-inch x 6-inch and 6-inch x 8-inch sections. This value is less than 2 psid. The maximum rupture value for the second disc must be less than the minimum rupture value for the first disc less 2 psid i.e. < 16.3.

  15. Spontaneous rupture of liver during pregnancy.

    PubMed

    Mäntymaa, M L; Ekblad, U

    1994-01-01

    Spontaneous rupture of the hepatic capsule and subsequent massive intra-abdominal bleeding is a rare but life-threatening complication of pregnancy, which is often associated with pregnancy-induced hypertension. High maternal and fetal mortality rates have been reported. We describe a case with massive intra-abdominal bleeding. The diagnosis and treatment of this condition are discussed. PMID:8092784

  16. The physics of strain localization in dynamic earthquake rupture simulations

    E-print Network

    Daub,Eric G.

    The physics of strain localization in dynamic earthquake rupture simulations Eric G. Daub) and Jean M. Carlson (UCSB) #12;Goal: improve our understanding of the basic physics of earthquake rupture of Earthquakes Seismologists do not have a complete description of the physics governing earthquake rupture. Why

  17. Intermediate Temperature Strength Degradation in SiC/SiC Composites

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Cawley, James D.; Levine, Stanley (Technical Monitor)

    2001-01-01

    Woven silicon carbide fiber-reinforced, silicon carbide matrix composites are leading candidate materials for an advanced jet engine combustor liner application. Although the use temperature in the hot region for this application is expected to exceed 1200 C, a potential life-limiting concern for this composite system exists at intermediate temperatures (800 +/- 200 C), where significant time-dependent strength degradation has been observed under stress-rupture loading. A number of factors control the degree of stress-rupture strength degradation, the major factor being the nature of the interphase separating the fiber and the matrix. BN interphases are superior to carbon interphases due to the slower oxidation kinetics of BN. A model for the intermediate temperature stress-rupture of SiC/BN/SiC composites is presented based on the observed mechanistic process that leads to strength degradation for the simple case of through-thickness matrix cracks. The approach taken has much in common with that used by Curtin and coworkers, for two different composite systems. The predictions of the model are in good agreement with the rupture data for stress-rupture of both precracked and as-produced composites. Also, three approaches that dramatically improve the intermediate temperature stress-rupture properties are described: Si-doped BN, fiber spreading, and 'outside debonding'.

  18. Creep-rupture behavior of seven iron-base alloys after long term aging at 760 deg in low pressure hydrogen

    NASA Technical Reports Server (NTRS)

    Witzke, W. R.; Stephens, J. R.

    1980-01-01

    Seven candidate iron-base alloys for heater tube application in the Stirling automotive engine were aged for 3500 hours at 760 C in argon and hydrogen. Aging degraded the tensile and creep-rupture properties. The presence of hydrogen during aging caused additional degradiation of the rupture strength in fine grain alloys. Based on current design criteria for the Mod 1 Stirling engine, N-155 and 19-9DL are considered the only alloys in this study with strengths adequate for heater tube service at 760 C.

  19. [Ettore Majoran's transversal epistemology].

    PubMed

    Bontems, Vincent

    2013-01-01

    « Il valore delle leggi statistiche nella fisica e nelle scienze sociali » is Ettore Majorana's only work on science. It offers a critique of classical determinism, establishing an analogy between the laws of quantum mechanics and social science and arguing that both are intrinsically linked to probability. This article first studies this argument from the standpoing of metaphysics, physics, and sociology, and then assesses the significance of this transversal epistemology. PMID:23636783

  20. Lifetimes statistics for single Kevlar 49 aramid filaments in creep-rupture at elevated temperatures

    SciTech Connect

    Wu, H.F.

    1987-01-01

    Kevlar 49 fibrous composites are routinely fabricated to have strengths above 1.5 GPa(200 ksi), but in many applications one would like to sustain such stresses for long time periods, sometimes at elevated temperatures. Thus the temperature dependence of the creep-rupture process in the fibers is of interest. Experimental data are presented for the lifetime of single Kevlar 49 filaments under constant stress at elevated temperatures. The goal of this research was to fully characterize the statistical strength and lifetime behavior of single filaments in order to separate fiber effects from fiber/matrix interactions in the creep-rupture lifetime of Kevlar 49/epoxy composites as described for example in Phoenix and Wu (1983). First we conducted experiments to determine distributions for the strength of filaments from the two distinct spools as a function of temperature. As expected, the data could generally be fitted by a two-parameter Weibull distribution. Lifetime experiments at 80 and 130/sup 0/C were conducted at several stress levels chosen as suitable fractions of the Weibull scale parameter for short-term strength for that temperature. The lifetime data were well modelled by a two-parameter Weibull distribution with large variability.

  1. Upper extremity injuries associated with strength training.

    PubMed

    Haupt, H A

    2001-07-01

    Most injuries sustained during strength training are mild strains that resolve with appropriate rest. More severe injuries include traumatic shoulder dislocations, tendon ruptures of the pectoralis major, biceps, and triceps; stress fractures of the distal clavicle, humerus, radius, and ulna; traumatic fractures of the distal radius and ulna in adolescent weightlifters; and compressive and stretch neuropathies. These more severe injuries are usually the result of improperly performing a strength training exercise. Educating athletes regarding proper strength-training techniques serves to reverse established injury patterns and to prevent these injuries in the first place. Recognizing the association of anabolic steroid use to several of the injury patterns further reinforces the need for medical specialists to counsel athletes against their use. With the increasing use of supplements such as creatine, the incidence and nature of strength-training injuries may change further. Greater emphasis on the competitive performance of younger athletes undoubtedly will generate enthusiasm for strength training at earlier ages in both sexes. The importance of proper supervision of these young athletes by knowledgeable persons will increase. As the popularity of strength training grows, there will be ample opportunity to continue to catalog the injury patterns associated with this activity. PMID:11494836

  2. Reconstruction of a ruptured patellar tendon using ipsilateral semitendinosus and gracilis tendons with preserved distal insertions: two case reports

    PubMed Central

    2013-01-01

    Background Acute patellar tendon ruptures with poor tissue quality. Ruptures that have been neglected are difficult to repair. Several surgical techniques for the repair of the patellar tendon have been reported, however, these techniques remain difficult because of contractures, adhesions, and atrophy of the quadriceps muscle after surgery. Case presentation We report the cases of 2 Japanese patients (Case 1: a 16-year-old male and Case 2: a 43-year-old male) with patellar tendon ruptures who were treated by reconstruction using semitendinosus-gracilis (STG) tendons with preserved distal insertions. Retaining the original insertion of the STG appears to preserve its viability and provide the revascularization necessary to accelerate healing. Both tendons were placed in front of the patella, in a figure-of-eight fashion, providing stability to the patella. Conclusion Both patients recovered near normal strength and stability of the patellar tendon as well as restoration of function after the operation. PMID:24010848

  3. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation.

    PubMed

    Saltzman, Bryan M; Harris, Joshua D; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  4. Proximal coracobrachialis tendon rupture, subscapularis tendon rupture, and medial dislocation of the long head of the biceps tendon in an adult after traumatic anterior shoulder dislocation

    PubMed Central

    Saltzman, Bryan M.; Harris, Joshua D.; Forsythe, Brian

    2015-01-01

    Rupture of the coracobrachialis is a rare entity, in isolation or in combination with other muscular or tendinous structures. When described, it is often a result of direct trauma to the anatomic area resulting in rupture of the muscle belly. The authors present a case of a 57-year-old female who suffered a proximal coracobrachialis tendon rupture from its origin at the coracoid process, with concomitant subscapularis tear and medial dislocation of the long head of biceps tendon after first time traumatic anterior shoulder dislocation. Two weeks after injury, magnetic resonance imaging suggested the diagnosis, which was confirmed during combined arthroscopic and open technique. Soft-tissue tenodesis of coracobrachialis to the intact short head of the biceps, tenodesis of the long head of biceps to the intertubercular groove, and double-row anatomic repair of the subscapularis were performed. The patient did well postoperatively, and ultimately at 6 months follow-up, she was without pain, and obtained 160° of active forward elevation, 45° of external rotation, internal rotation to T8, 5/5 subscapularis and biceps strength. Scoring scales had improved from the following preoperative to final follow-up: American Shoulder and Elbow Surgeons, 53.33-98.33; constant, 10-100; visual analogue scale-pain, 4-0. DASH score was 5. PMID:25937715

  5. The intercalated tendon graft for treatment of extensor pollicis longus tendon rupture.

    PubMed

    Magnell, T D; Pochron, M D; Condit, D P

    1988-01-01

    Twenty-one patients with ruptures of the extensor pollicis longus tendon were treated with a subcutaneously placed free tendon graft. The repair was performed a mean of 6 weeks after rupture, range from 1 to 21 weeks. Data was collected on 19 of these patients, with a mean follow-up of 30 months, range from 6 to 124 months. Near uniform satisfaction was reported. The mean loss of interphalangeal joint extension and flexion and combined metacarpophalangeal-interphalangeal joint motion was 6 degrees, 3 degrees, and 10 degrees, respectively. The mean loss of pinch strength was 7%. All patients were able to elevate their thumbs to the level of the palm. This is a simple, reliable, and effective procedure that avoids the use of an adjacent motor-tendon unit. Muscle contracture appears reversible and this procedure may be used successfully even when treatment has been delayed. PMID:3351213

  6. Slip-pulse rupture behavior on a 2 m granite fault

    NASA Astrophysics Data System (ADS)

    McLaskey, Gregory C.; Kilgore, Brian D.; Beeler, Nicholas M.

    2015-09-01

    We describe observations of dynamic rupture events that spontaneously arise on meter-scale laboratory earthquake experiments. While low-frequency slip of the granite sample occurs in a relatively uniform and crack-like manner, instruments capable of detecting high-frequency motions show that some parts of the fault slip abruptly (velocity > 100 mm s-1, acceleration > 20 km s-2) while the majority of the fault slips more slowly. Abruptly slipping regions propagate along the fault at nearly the shear wave speed. We propose that the dramatic reduction in frictional strength implied by this pulse-like rupture behavior has a common mechanism to the weakening reported in high-velocity friction experiments performed on rotary machines. The slip pulses can also be identified as migrating sources of high-frequency seismic waves. As observations from large earthquakes show similar propagating high-frequency sources, the pulses described here may have relevance to the mechanics of larger earthquakes.

  7. Mixed adenoneuroendocrine carcinoma of the colon progressed rapidly after hepatic rupture: report of a case.

    PubMed

    Ito, Hiromitsu; Kudo, Atsushi; Matsumura, Satoshi; Ban, Daisuke; Irie, Takumi; Ochiai, Takanori; Nakamura, Noriaki; Tanaka, Shinji; Tanabe, Minoru

    2014-01-01

    The rupture of a metastatic mixed adenoneuroendocrine carcinoma (MANEC) has not been previously reported, although the neuroendocrine cell carcinoma is often associated with a high incidence of hepatic metastases. The patient was a 39-year-old male who presented with upper abdominal pain over 3 months. Computed tomography showed multiple tumors in both hepatic lobes, while lower gastrointestinal endoscopy revealed a tumor in the transverse colon. Histopathologic examination of the tumor revealed it to be a neuroendocrine cell carcinoma. After the resection of the primary tumor, hepatic metastases rapidly increased, and one of them in the left lateral segment was ruptured with significant hemorrhage. The rupture led us to undertake the emergency operation to stop the bleeding. Histology showed a high-grade large-cell neuroendocrine carcinoma associated with moderately differentiated tubular adenocarcinoma. The Ki-67 labeling index was 80% (G3). The diagnosis was mixed adenoneuroendocrine carcinoma according to the 2010 World Health Organization guidelines. Hepatic arterial infusion chemotherapy, systemic chemotherapy, and transcatheter arterial chemoembolization did not decrease the tumor progress, and the patient died on postoperative day 110. Reporting this highly malignant case, I hope all doctors can be interested in MANEC. PMID:24444267

  8. Megathrust Properties and Large Earthquake Rupture Processes

    NASA Astrophysics Data System (ADS)

    Lay, T.; Ye, L.; Kanamori, H.

    2014-12-01

    Constraining physical controls on seismic rupture of plate boundary megathrust faults is challenging due to observational limitations, but seismic, geodetic, tsunami, electromagnetic, geologic and hydrologic studies are steadily accumulating data that hold potential of advancing our understanding of subduction fault zones. Very shallow (< 15 km deep) megathrust earthquakes are rare, but intermittently occur as large tsunami earthquakes such as the 2010 Mentawai Mw 7.8 event. This rupture occurred up-dip of prior large interplate ruptures in the Sumatra subduction zone in 2007, and rupture extended all the way to the trench, but with patchy large-slip regions that can only be confidently resolved using tsunami observations. The seismic wave radiation from tsunami earthquakes is now established to be distinct from that of ruptures deeper on the megathrust, but the controlling factors are not well-resolved. Smaller events at shallow depths tend to have diverse rupture processes, but some are also anomalously depleted in short-period radiation, suggesting that the shallow environment has variable scale-lengths of frictional heterogeneity. At the other end of the megathrust, large events deeper than about 35 km tend to have modest enhancement of short-period seismic wave radiation, with somewhat lower slope to their short-period source spectra than typical of shallower events. The controlling process are also not well-resolved for this behavior. These depth-variations of megathrust earthquake source spectra are one class of observations that may relate to pressure- and temperature-dependent evolution of the megathrust from the trench to decoupling depths near 45-50 km. Other attributes of seismic sources, such as static stress drop and moment-scaled radiated energy have large variability, but do not show systematic variations with depth on the megathrust, so some attributes of earthquake processes are not strongly influenced by evolving conditions of the plate boundary. We explore these issues based on a recent seismological study of all large interplate earthquakes from 1990-2014 combined with detailed investigations of several recent large and great earthquakes for which we have unprecedented geophysical data sets.

  9. Isolated Total Rupture of Extraocular Muscles

    PubMed Central

    Chen, Jingchang; Kang, Ying; Deng, Daming; Shen, Tao; Yan, Jianhua

    2015-01-01

    Abstract Total rupture of extraocular muscles is an infrequent clinical finding. Here we conducted this retrospective study to evaluate their causes of injury, clinical features, imaging, surgical management, and final outcomes in cases of isolated extraocular muscle rupture at a tertiary center in China. Thirty-six patients were identified (24 men and 12 women). Mean age was 34 years (range 2–60). The right eye was involved in 21 patients and the left 1 in 15. A sharp object or metal hook was the cause of this lesion in 16 patients, sinus surgery in 14 patients, traffic accident in 3 patients, orbital surgery in 2 patients, and conjunctive tumor surgery in 1 patient. The most commonly involved muscles were medial (18 patients) and inferior rectus muscles (13 patients). The function of the ruptured muscles revealed a scale of ?3 to ?4 defect of ocular motility and the amount of deviation in primary position varied from 10 to 140 PD (prism diopter). Computerized tomography (CT) confirmed the presence of ruptured muscles. An end-to-end muscle anastomosis was performed and 3 to 5?mm of muscle was resected in 23 patients. When the posterior border of the injured muscle could not be identified (13 patients), a partial tendon transposition was performed, together with recession of the antagonist in most patients, whereas a recession of the antagonist muscle plus a resection of the involved muscle with or without nasal periosteal fixation was performed in the remaining patients. After an average of 16.42 months of follow-up an excellent result was achieved in 23 patients and results of 13 patients were considered as a failure. In most patients, the posterior border of the ruptured muscle can be identified and an early surgery can be performed to restore function. Alternatively, a partial tendon transposition should be performed. When muscular rupture is suspected, an early orbital CT is required to confirm this possibility, which can then verify the necessity for an early surgical intervention. PMID:26426604

  10. Spin resonance strength calculation through single particle tracking for RHIC

    SciTech Connect

    Luo, Y.; Dutheil, Y.; Huang, H.; Meot, F.; Ranjbar, V.

    2015-05-03

    The strengths of spin resonances for the polarized-proton operation in the Relativistic Heavy Ion Collider are currently calculated with the code DEPOL, which numerically integrates through the ring based on an analytical approximate formula. In this article, we test a new way to calculate the spin resonance strengths by performing Fourier transformation to the actual transverse magnetic fields seen by a single particle traveling through the ring. Comparison of calculated spin resonance strengths is made between this method and DEPOL.

  11. Neutron Transversity at Jefferson Lab

    SciTech Connect

    Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

    2005-09-07

    Nucleon transversity and single transverse spin asymmetries have been the recent focus of large efforts by both theorists and experimentalists. On-going and planned experiments from HERMES, COMPASS and RHIC are mostly on the proton or the deuteron. Presented here is a planned measurement of the neutron transversity and single target spin asymmetries at Jefferson Lab in Hall A using a transversely polarized {sup 3}He target. Also presented are the results and plans of other neutron transverse spin experiments at Jefferson Lab. Finally, the factorization for semi-inclusive DIS studies at Jefferson Lab is discussed.

  12. Layer- and direction-specific material properties, extreme extensibility and ultimate material strength of human abdominal aorta and aneurysm: a uniaxial extension study

    E-print Network

    Teng, Zhongzhao; Feng, Jiaxuan; Zhang, Yongxue; Huang, Yuan; Sutcliffe, Michael P. F.; Brown, Adam J.; Jing, Zaiping; Gillard, Jonathan H.; Lu, Qingsheng

    2015-04-24

    of extreme extensibility and ultimate material strength of the tissue are important if rupture is to be modelled. Tissue pieces from 11 abdomen aortic aneurysm (AAA) from patients scheduled for elective surgery and from 8 normal aortic artery (NAA) from...

  13. Design prediction for long term stress rupture service of composite pressure vessels

    NASA Technical Reports Server (NTRS)

    Robinson, Ernest Y.

    1992-01-01

    Extensive stress rupture studies on glass composites and Kevlar composites were conducted by the Lawrence Radiation Laboratory beginning in the late 1960's and extending to about 8 years in some cases. Some of the data from these studies published over the years were incomplete or were tainted by spurious failures, such as grip slippage. Updated data sets were defined for both fiberglass and Kevlar composite stand test specimens. These updated data are analyzed in this report by a convenient form of the bivariate Weibull distribution, to establish a consistent set of design prediction charts that may be used as a conservative basis for predicting the stress rupture life of composite pressure vessels. The updated glass composite data exhibit an invariant Weibull modulus with lifetime. The data are analyzed in terms of homologous service load (referenced to the observed median strength). The equations relating life, homologous load, and probability are given, and corresponding design prediction charts are presented. A similar approach is taken for Kevlar composites, where the updated stand data do show a turndown tendency at long life accompanied by a corresponding change (increase) of the Weibull modulus. The turndown characteristic is not present in stress rupture test data of Kevlar pressure vessels. A modification of the stress rupture equations is presented to incorporate a latent, but limited, strength drop, and design prediction charts are presented that incorporate such behavior. The methods presented utilize Cartesian plots of the probability distributions (which are a more natural display for the design engineer), based on median normalized data that are independent of statistical parameters and are readily defined for any set of test data.

  14. Short slip duration in dynamic rupture in the presence of heterogeneous fault properties

    NASA Astrophysics Data System (ADS)

    Beroza, Gregory C.; Mikumo, Takeshi

    1996-10-01

    Recent studies of strong motion data consistently show that the risetime (duration of slip at particular locations on the fault) is significantly shorter than the overall rupture duration. The physical explanation for this observation and its implications have become central issues in earthquake source studies. Two classes of mechanisms have been proposed to explain short risetimes. One explanation is that velocity-weakening frictional behavior on the fault surface causes the fault to self-heal. This possibility is suggested by rate-dependent friction observed in laboratory experiments and by some two-dimensional dynamic numerical simulations of earthquake rupture. It has recently been demonstrated, however, that the velocity dependence of friction observed in the laboratory is too weak to cause faults to self-heal. An alternative explanation for short risetimes is that spatially heterogeneous fault strength (e.g., barriers) limit the slip duration. In this paper we investigate this second explanation for short risetimes by constructing a three-dimensional dynamic rupture model for the 1984 Morgan Hill, California earthquake (Mw = 6.2) using a kinematic model previously obtained from waveform inversion of strong motion data. We assume velocity-independent friction and a critical stress fracture criterion and derive a dynamic model specified by the spatial distribution of dynamic stress drop and strength excess that reproduces the slip and rupture time of the kinematic model. The slip velocity time functions calculated from this dynamic model are then used in a subsequent inversion to fit the strong motion data. By alternating between dynamic and kinematic modeling, we obtain a dynamic model that provides an acceptable fit to the recorded waveforms. In this dynamic model the risetime is short over most of the fault, which is attributable entirely to the short scale-length slip/stress drop heterogeneity required by the strong motion data. A self-healing mechanism, such as strongly velocity-dependent friction, is not required to explain the short risetimes observed in this earthquake.

  15. Rupture directivity of moderate earthquakes in northern California

    USGS Publications Warehouse

    Seekins, Linda C.; Boatwright, John

    2010-01-01

    We invert peak ground velocity and acceleration (PGV and PGA) to estimate rupture direction and rupture velocity for 47 moderate earthquakes (3.5?M?5.4) in northern California. We correct sets of PGAs and PGVs recorded at stations less than 55–125 km, depending on source depth, for site amplification and source–receiver distance, then fit the residual peak motions to the unilateral directivity function of Ben-Menahem (1961). We independently invert PGA and PGV. The rupture direction can be determined using as few as seven peak motions if the station distribution is sufficient. The rupture velocity is unstable, however, if there are no takeoff angles within 30° of the rupture direction. Rupture velocities are generally subsonic (0.5?–0.9?); for stability, we limit the rupture velocity at v=0.92?, the Rayleigh wave speed. For 73 of 94 inversions, the rupture direction clearly identifies one of the nodal planes as the fault plane. The 35 strike-slip earthquakes have rupture directions that range from nearly horizontal (6 events) to directly updip (5 events); the other 24 rupture partly along strike and partly updip. Two strike-slip earthquakes rupture updip in one inversion and downdip in the other. All but 1 of the 11 thrust earthquakes rupture predominantly updip. We compare the rupture directions for 10 M?4.0 earthquakes to the relative location of the mainshock and the first two weeks of aftershocks. Spatial distributions of 8 of 10 aftershock sequences agree well with the rupture directivity calculated for the mainshock.

  16. Transverse Spin Diffusion

    NASA Astrophysics Data System (ADS)

    Mullin, William

    2014-05-01

    Transverse spin diffusion is a relatively new transport coefficient and a review of its history and physical basis will be presented. In NMR spin diffusion is often measured by spin echo techniques, which involve spin currents perpendicular to the direction of the magnetization, in contrast with the usual longitudinal case where the current is parallel to the magnetization. The first indication that this involved new physics was the Leggett-Rice effect (1970) in which spin waves, new spin-echo behavior, and an altered spin diffusion coefficient were predicted in liquid 3He. This effect gave the possibility of the first measurement of F1a, the parameter of the Landau Fermi-liquid theory mean-field responsible for the effect. In 1982 Lhuillier and Laloe found a transport equation very similar to the Leggett equation, but valid for highly-polarized dilute Boltzmann Bose and Fermi gases, and describing the ``identical spin rotation effect'' (ISRE), the analog of a Landau mean field. Coincidentally Bashkin and Meyerovich had also given equivalent descriptions of transport in polarized Boltzmann gases. That a mean-field effect could exists in dilute Boltzmann gases was theoretically surprising, but was confirmed experimentally. At low polarization the basic transverse diffusion constant D? coincides with the longitudinal value D? however Meyerovich first pointed out that they could differ in highly polarized degenerate gases. Indeed detailed calculations (Jeon and Mullin) showed that, while D? is proportional to T-2, D? approaches a constant (depending on polarization) at low T. Considerable controversy existed until experimental verification was achieved in 2004. The importance of ISRE again arose in 2008 as the basis of ``anomalous spin-state segregation'' in Duke and JILA experiments. More recently application of the ideas of transverse spin diffusion to strongly interacting Fermi gases has resulted in the observation of the diffusion constants at the quantum limit where D ~ ? / m .

  17. Transverse field focused system

    DOEpatents

    Anderson, Oscar A. (Berkeley, CA)

    1986-01-01

    A transverse field focused (TFF) system for transport or acceleration of an intense sheet beam of negative ions in which a serial arrangement of a plurality of pairs of concentric cylindrical-arc electrodes is provided. Acceleration of the sheet beam can be achieved by progressively increasing the mean electrode voltage of successive electrode pairs. Because the beam is curved by the electrodes, the system can be designed to transport the beam through a maze passage which is baffled to prevent line of sight therethrough. Edge containment of the beam can be achieved by shaping the side edges of the electrodes to produce an electric force vector directed inwardly from the electrode edges.

  18. Megakaryocyte rupture for acute platelet needs

    PubMed Central

    Stritt, Simon

    2015-01-01

    Circulating platelets were thought to arise solely from the protrusion and fragmentation of megakaryocyte cytoplasm. Now, Nishimura et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201410052) show that platelet release from megakaryocytes can be induced by interleukin-1? (IL-1?) via a new rupture mechanism, which yields higher platelet numbers, occurs independently of the key regulator of megakaryopoiesis thrombopoietin, and may occur during situations of acute platelet need. PMID:25963815

  19. Megakaryocyte rupture for acute platelet needs.

    PubMed

    Nieswandt, Bernhard; Stritt, Simon

    2015-05-11

    Circulating platelets were thought to arise solely from the protrusion and fragmentation of megakaryocyte cytoplasm. Now, Nishimura et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201410052) show that platelet release from megakaryocytes can be induced by interleukin-1? (IL-1?) via a new rupture mechanism, which yields higher platelet numbers, occurs independently of the key regulator of megakaryopoiesis thrombopoietin, and may occur during situations of acute platelet need. PMID:25963815

  20. [Esthetic surgery and psychological rupture states].

    PubMed

    Julliard, F A

    1991-01-01

    Although the psychological profile of patients requesting cosmetic surgery is often similar, the consequences of surgery can be dramatic in certain cases and result in a true state of rupture. The various forms, depression or aggression, and the conditions of onset are analysed. The four essential predisposing factors are: lack of information, result-satisfaction dichotomy, patient-surgeon divorce, and the responsibility of colleagues who, as a result of their inconsiderable comments, destabilize an already fragile psychological state. PMID:1721785

  1. Endovascular Treatment of Ruptured Pericallosal Artery Aneurysms

    PubMed Central

    Ko, Jun Kyeung; Kim, Hwan Soo; Choi, Hyuk Jin; Lee, Tae Hong; Yun, Eun Young

    2015-01-01

    Objective Aneurysms arising from the pericallosal artery (PA) are uncommon and challenging to treat. The aim of this study was to report our experiences of the endovascular treatment of ruptured PA aneurysms. Methods From September 2003 to December 2013, 30 ruptured PA aneurysms in 30 patients were treated at our institution via an endovascular approach. Procedural data, clinical and angiographic results were retrospectively reviewed. Results Regarding immediate angiographic control, complete occlusion was achieved in 21 (70.0%) patients and near-complete occlusion in 9 (30.0%). Eight procedure-related complications occurred, including intraprocedural rupture and early rebleeding in three each, and thromboembolic event in two. At last follow-up, 18 patients were independent with a modified Rankin Scale (mRS) score of 0-2, and the other 12 were either dependent or had expired (mRS score, 3-6). Adjacent hematoma was found to be associated with an increased risk of poor clinical outcome. Seventeen of 23 surviving patients underwent follow-up conventional angiography (mean, 16.5 months). Results showed stable occlusion in 14 (82.4%), minor recanalization in two (11.8%), and major recanalization, which required recoiling, in one (5.9%). Conclusion Our experiences demonstrate that endovascular treatment for a ruptured PA aneurysms is both feasible and effective. However, periprocedural rebleedings were found to occur far more often (20.0%) than is generally suspected and to be associated with preoperative contrast retention. Analysis showed existing adjacent hematoma is predictive of a poor clinical outcome. PMID:26539261

  2. Mechanism of rupture of single adsorbed vesicles

    NASA Astrophysics Data System (ADS)

    Zhdanov, Vladimir P.

    2015-11-01

    Rupture of single adsorbed lipid vesicles is believed to occur via pore formation in the membrane. The latter process is related to the support-induced membrane strain. It includes membrane bending primarily near the rim of the vesicle-substrate contact area and tension distributed over the whole membrane. Herein, the relative role of these two factors is scrutinized from the perspectives of general theory and available experiments. The former factor is concluded to dominate.

  3. Transverse relaxation mechanisms in articular cartilage.

    PubMed

    Mlynárik, V; Szomolányi, P; Toffanin, R; Vittur, F; Trattnig, S

    2004-08-01

    Relaxation rates in the rotating frame (R1rho) and spin-spin relaxation rates (R2) were measured in articular cartilage at various orientations of cartilage layer to the static magnetic field (B0), at various spin locking field strengths and at two different static magnetic field strengths. It was found that R1rho in the deep radial zone depended on the orientation of specimens in the magnet and decreased with increasing the spin locking field strength. In contrast, R1rho values in the transitional zone were nearly independent of the specimen orientation and the spin locking field strength. Measurements of the same specimens at 2.95 and 7.05 T showed an increase of R1rho and most R2 values with increasing B0. The inverse B0 dependence of some R2 values was probably due to a multicomponent character of the transverse magnetization decay. The experiments revealed that the dominant T1rho and T2 relaxation mechanism at B0 < or = 3 T is a dipolar interaction due to slow anisotropic motion of water molecules in the collagen matrix. On average, the contribution of scalar relaxation due to rapid proton exchange in femoral head cartilage at 2.95 T is about 6% or less of the total R1rho at the spin locking field of 1000 Hz. PMID:15261626

  4. Transient gravity perturbations induced by earthquake rupture

    NASA Astrophysics Data System (ADS)

    Harms, J.; Ampuero, J.-P.; Barsuglia, M.; Chassande-Mottin, E.; Montagner, J.-P.; Somala, S. N.; Whiting, B. F.

    2015-06-01

    The static and transient deformations produced by earthquakes cause density perturbations which, in turn, generate immediate, long-range perturbations of the Earth's gravity field. Here, an analytical solution is derived for gravity perturbations produced by a point double-couple source in homogeneous, infinite, non-self-gravitating elastic media. The solution features transient gravity perturbations that occur at any distance from the source between the rupture onset time and the arrival time of seismic P waves, which are of potential interest for real-time earthquake source studies and early warning. An analytical solution for such prompt gravity perturbations is presented in compact form. We show that it approximates adequately the prompt gravity perturbations generated by strike-slip and dip-slip finite fault ruptures in a half-space obtained by numerical simulations based on the spectral element method. Based on the analytical solution, we estimate that the observability of prompt gravity perturbations within 10 s after rupture onset by current instruments is severely challenged by the background microseism noise but may be achieved by high-precision gravity strainmeters currently under development. Our analytical results facilitate parametric studies of the expected prompt gravity signals that could be recorded by gravity strainmeters.

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

    SciTech Connect

    Ar Latin-Small-Letter-Dotless-I bas, Bilgin Kadri Dingil, Guerbuez; Koeroglu, Mert; Uenguel, Uemit; Zaral Latin-Small-Letter-Dotless-I , Aliye Ceylan

    2011-02-15

    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.

  6. Why Strength Training?

    MedlinePLUS

    ... week. Strength training, particularly in conjunction with regular aerobic exercise, can also have a profound impact on ... gained not only strength and flexibility but also aerobic capacity when they did strength training three times ...

  7. Rupture Velocities of Intermediate- and Deep-Focus Earthquakes

    NASA Astrophysics Data System (ADS)

    Warren, L. M.

    2014-12-01

    The rupture velocities of intermediate- and deep-focus earthquakes --- how they vary between subduction zones, how they vary with depth, and what their maximum values are --- may help constrain the mechanism(s) of the earthquakes. As part of a global study of intermediate- and deep-focus earthquakes, I have used rupture directivity to estimate the rupture vector (speed and orientation) for 422 earthquakes >70 km depth with MW ?5.7 since 1990. I estimate the rupture velocity relative to the local P-wave velocity (vr/?). Since the same method is used for all earthquakes, the results can be readily compared across study areas. The study areas --- Middle America, South America, Tonga-Kermadec, Izu-Bonin-Marianas, and Japan-Kurils-Kamchatka --- include some of the warmest and coldest subduction zones: subducting plate ages range from 9-150 Myr and descent rates range from 1-13 cm/yr. Across all subduction zones and depth ranges, for the 193 earthquakes with observable directivity and well-constrained rupture vectors, most earthquakes rupture on the more horizontal of the two possible nodal planes. However, the rupture vectors appear to be randomly-oriented relative to the slip vector, so the earthquakes span the continuum from Mode II (i.e., parallel slip and rupture vectors) to Mode III rupture (i.e., perpendicular slip and rupture vectors). For this earthquake population, the mean rupture velocity is 0.43 vr/? ± 0.14 vr/?. The mean earthquake rupture velocities are similar between all subduction zones. Since the local seismic wavespeed is faster in colder subduction zones, absolute rupture velocities are faster in colder subduction zones. Overall, the fastest rupture velocities exceed the local S-wave speed. The supershear ruptures are associated with earthquakes closer to Mode II than Mode III faulting. This is consistent with theoretical calculations, which limit the rupture velocity to the S-wave speed for Mode III rupture but the P-wave speed for Mode II rupture.

  8. Association between patella spurs and quadriceps tendon ruptures

    PubMed Central

    Ellanti, Prasad; Moriarity, Andrew; Wainberg, Nikita; Fhoghlu, Cliodhna Ni; McCarthy, Tom

    2015-01-01

    Summary Background quadriceps tendon (QT) ruptures are significant injuries that are relatively uncommon. The diagnosis of QT ruptures is frequently missed or delayed. An association between the presence of a patella spur and QT ruptures has been suggested in the literature. Patients and methods the Hospital Inpatient Enquiry system was used to gather data on all patients who sustained a QT rupture over a six year period from 2008 to 2014. A retrospective review of the medical notes as well as radiographs was undertaken. We reviewed 200 knee radiographs of patients without QT ruptures to establish the incidence of patella spurs in our normal population. Statistical analysis was performed using SPSS version 11.5 for Windows®. Results the records of 20 consecutive patients with 21 QT ruptures were reviewed. The mean age was 60.9 yrs (range 44.9–82.1 yrs) and the majority were male (n=17; 85%). There was one bilateral QT ruptures. Patella spurs were noted in 13 cases (62%) which were significantly higher than in patients without QT rupture 19% (P?0.05). Conclusion we noted a significantly higher incidence of patella spurs in patients with QT ruptures compared to those without. The presence of a QT rupture should be ruled out in patients with a knee injury and a patella spur on the knee radiographs. PMID:26261786

  9. Dynamic Rupture along a Material Interface: Background, Implications, and Recent Seismological Observations

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; McGuire, J.

    2003-04-01

    Natural fault systems have interfaces that separate different media. There are fundamental differences between in-plane ruptures on planar faults that separate similar and dissimilar elastic solids. In a linear isotropic homogeneous solid, slip does not change the normal stress on the rupture plane. However, if the fault separates different materials in-plane slip can produce strong variations of normal stress on the fault. The interaction between slip and normal stress along a material interface can reduce dynamically the frictional strength, making material interfaces mechanically favored surfaces for rupture propagation. Analytical and numerical works (Weertman, 1980; Adams, 1995; Andrews and Ben-Zion, 1997; Ben-Zion and Andrews, 1998) have shown that rupture along a material interface occurs as a narrow wrinkle-like pulse propagating spontaneously only in one direction, that of slip in the more compliant medium. Characteristic features of the wrinkle-like pulse include: (1) Strong correlation between variations of normal stress and slip. (2) Asymmetric motion on different sides of the fault. (3) Preferred direction of rupture propagation. (4) Self-sharpening and divergent behavior with propagation distance. These characteristics can be important to a number of fundamental issues, including trapping of rupture in structures with material interfaces, the heat flow paradox, short rise-time of earthquake slip, possible existence of tensile component of rupture, and spatial distribution of seismic shaking. Rubin and Gillard (2000), Rubin (2002) and McGuire et al. (2002) presented some seismological evidence that rupture propagation along the San Andreas and other large faults is predominantly unidirectional. Features (1)-(4) are consistent with observations from lab sliding and fracture experiments (Anooshehpoor and Brune, 1999; Schallamach, 1971; Samudrala and Rosakis, 2000). Cochard and Rice (2000) performed calculations of rupture along a material interface governed by a regularized friction having a gradual response of strength to an abrupt variation of normal stress. Their calculations confirmed features (1)-(3) and showed hints of feature (4). The latter was not fully developed in their results because the calculations did not extend long enough in time. Ben-Zion and Huang (2002) simulated dynamic rupture on an interface governed by the regularized friction between a low velocity layer and a surrounding host rock. The results show that the self-sharpening and divergent behavior exists also with the regularized friction for large enough propagation distance. The simulations of Ben-Zion and Huang suggest that in fault structures having a low velocity layer, rupture initiated by failing of an asperity with size not larger than the layer width can become a self-sustaining wrinkle-like pulse. However, if the initial asperity is much larger than the layer width, the rupture will not propagate as a self-sustaining pulse (unless there is also an overall contrast across the fault). The Bear Valley section of the San Andreas Fault separates high velocity block on the SW from a low-velocity material on the NE. This contrast is expected to generate a preference for rupture to the SE and fault zone head-waves on the NE block. Using seismograms from a high density temporary array (Thurber et al., 1997), we measured differential travel-times of head-waves along with the geometrical distribution of the stations at which they arrive prior to the direct P-wave. The travel-time data and spatial distribution of events and stations associated with headwave first arrivals are compatible with the theoretical results of Ben-Zion (1989). We are now modeling waveforms to obtain high resolution image of the fault-zone structure. To test the prediction of unidirectional rupture propagation, we estimate the space-time variances of the moment-release distribution of magnitude 2.5-3.0 events using a variation of the Empirical Green's Function technique. Initial results for a few small events indicate rupture propagation in both directions. We are

  10. The Energy Budget of Earthquake Rupture: a View From Spontaneous Rupture Modeling and Finite-Source Models

    NASA Astrophysics Data System (ADS)

    Mai, P.; Guatteri, M.

    2003-12-01

    It is a common and frustrating experience of many dynamic modelers to initiate spontaneous rupture calculations that subsequently abort before rupturing to the desired earthquake size [Nielsen and Olsen, 2000; Oglesby and Day, 2002]. Source parameters in such dynamic source models are strongly correlated, but stress drop is the main factor affecting the distribution of the other dynamic rupture parameters. Additionally, the position of the hypocenter exerts a strong influence on the dynamic properties of the earthquake, and certain hypocenter positions are not plausible as those would not lead to spontaneous rupture propagation. To further investigate this last statement, we analyze the energy budget during earthquake rupture using spontaneous dynamic rupture calculations and finite-source rupture models. In describing the energy budget during earthquake rupture, we follow Favreau and Archuleta [2003]. Each point on the fault contributes to the radiated seismic energy Ers = Eel - Efr - Erx, where Eel denotes the elasto-static energy and Efr the fracture energy. In this study we neglect for simplicity the relaxation work Erx spent during the stopping of the earthquake. A rupture can be characterized by locally negative seismic energy density values, but its integral over the fault plane must be positive. The fundamental condition for rupture growth is therefore that the integral of Ers on the rupture area remains always positive during rupture propagation. Based on a simple energy budget calculation, we focus on identifying those target slip/stress distribution in dynamic rupture modeling that for a given hypocenter location fail to rupture spontaneously. Additionally, we study the energy budget of finite-source rupture models by analyzing the integrated seismic energy for the inferred slip maps using also hypocenter positions other than the network location. These results indicate how rupture was promoted for the true hypocenter while randomized hypocenters may not have been able to sustain a large earthquake. Our approach helped us both to speed up the computation of successful spontaneous rupture models, as well as to construct dynamically consistent rupture models for strong motion prediction.

  11. Intermediate Temperature Stress Rupture of Woven SiC Fiber, BN Interphase, SiC Matrix Composites in Air

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Levine, Stanley (Technical Monitor)

    2000-01-01

    Tensile stress-rupture experiments were performed on woven Hi-Nicalon reinforced SiC matrix composites with BN interphases in air. Modal acoustic emission (AE) was used to monitor the damage accumulation in the composites during the tests and microstructural analysis was performed to determine the amount of matrix cracking that occurred for each sample. Fiber fractograph), was also performed for individual fiber failures at the specimen fracture surface to determine the strengths at which fibers failed. The rupture strengths were significantly worse than what would have been expected front the inherent degradation of the fibers themselves when subjected to similar rupture conditions. At higher applied stresses the rate of rupture "?as larger than at lower applied stresses. It was observed that the change in rupture rate corresponded to the onset of through-thickness cracking in the composites themselves. The primary cause of the sen,ere degradation was the ease with which fibers would bond to one another at their closest separation distances, less than 100 nanometers, when exposed to the environment. The near fiber-to-fiber contact in the woven tows enabled premature fiber failure over large areas of matrix cracks due to the stress-concentrations created b), fibers bonded to one another after one or a few fibers fail. i.e. the loss of global load sharing. An@, improvement in fiber-to-fiber separation of this composite system should result in improved stress- rupture properties. A model was den,eloped in order to predict the rupture life-time for these composites based on the probabilistic nature of indin,idual fiber failure at temperature. the matrix cracking state during the rupture test, and the rate of oxidation into a matrix crack. Also incorporated into the model were estimates of the stress-concentration that would occur between the outer rim of fibers in a load-bearing bundle and the unbridged region of a matrix crack after Xia et al. For the lower stresses, this source of stress-concentration was the likely cause for initial fiber failure that would trigger catastrophic failure of the composite.

  12. Rupture process of the Wenchuan earthquake (Mw 7.9) from surface ruptures and fault striations characteristics

    NASA Astrophysics Data System (ADS)

    Pan, Jiawei; Li, Haibing; Si, Jialiang; Pei, Junling; Fu, Xiaofang; Chevalier, Marie-Luce; Liu, Dongliang

    2014-04-01

    On 12 May 2008, the Wenchuan earthquake (Mw 7.9) produced complicated thrust-type co-seismic surface rupture zones, which encompass the dextral-slip thrust of the Yingxiu-Beichuan fault, the approximately pure thrust of the Guanxian-Anxian fault, and the sinistral-slip thrust of the Xiaoyudong rupture zone located between the former two. In order to understand the faulting mechanism, we discuss the rupture process by examining the segmentation and kinematics of the surface rupture zones, together with the co-seismic fault striations at various sites. Based on the two along-strike main displacement peaks (6-6.5 m and 11-12 m) and on the different geometric and kinematic patterns for the southern and northern segments of the surface rupture zones, we find that the Wenchuan earthquake might have consisted of two rupture stages, which is in agreement with seismic wave inversion results. By comparing the kinematics of fault striations occurring in the Bajiaomiao and Beichuan areas, it suggests that during the first stage, thrusting along both the Yingxiu-Beichuan fault and Guanxian-Anxian fault produced the ~ 80-100 km-long Yingxiu-Qingping surface rupture segment and the ~ 80 km-long Guanxian-Anxian surface rupture zone, respectively. Then, faulting was triggered along the Yingxiu-Beichuan fault by the first rupture process, yielding the second rupture stage, which was characterized by dextral strike-slip (or dextral oblique thrusting). Due to the overlap between the two rupture stages, the southern segment (Yingxiu-Qingping) of the Yingxiu-Beichuan rupture zone comprises two different processes while the northern segment (Gaochuan-Beichuan-Shikan) only suggests one rupture phase.

  13. Missed Iatrogenic Bladder Rupture Following Normal Vaginal Delivery

    PubMed Central

    Baheti, Vidyasagar H; Patwardhan, Sujata K

    2015-01-01

    Bladder rupture following caesarian section is well documented complications. Intraperitoneal bladder rupture following normal vaginal delivery is very rare. Hereby, we present a case report of intraperitoneal bladder rupture presented late following normal vaginal delivery. We report a case of spontaneous intraperitoneal urinary bladder rupture following uneventful outlet forceps delivery in a 22-year-old primi gravid woman with gestational diabetes mellitus and fetal macrosomia who presented with large urinary ascites, anuria and renal failure. Emergent exploratory laparotomy with repair of the intraperitoneal bladder rupture helped to prevent its potential complications. Postpartum patients who undergo episiotomy or perineal repair may land up in unnoticed urinary retention which may rarely terminate in spontaneous urinary bladder rupture. Awareness of its manifestations amongst emergency physician would help to initiate appropriate timely management. PMID:26557563

  14. Formability Studies on Transverse Tailor Welded Blanks

    SciTech Connect

    Bhaskar, V. Vijay; Narasimhan, K.

    2005-08-05

    Tailor Welded Blanks (TWB) technology is one of the several approaches that have been used to reduce the weight of the automobile body. TWBs are made up of two or more blanks having different/same properties (geometry, material etc.) prior to forming. The formability of these blanks depends on material and geometric parameters like strength ratio and thickness ratio. The study of these blanks can be classified on the basis of the weld orientation chosen viz. transverse weld or longitudinal weld with respect to the major straining direction.This paper studies the formability issues related to transverse TWB by FE simulation. The formability is assessed by analyzing tensile and Limit Dome Height (LDH) tests. The weld region is assumed to be a line in all the simulations. While modeling the tensile test, ultimate tensile strength (UTS) and elongation are monitored, and in LDH testing, pole height and maximum load (in near plane strain condition) are monitored. LDH testing shows that as thickness ratio increases, the load bearing capacity and the pole height decreases. There is a contribution from both the thicker and the thinner blank to the overall deforming volume. Failure location analysis shows that there is an abrupt change in the location of the failure from punch nose region to weld line region as the thickness ratio reaches a critical magnitude (1.08).The study of material properties shows that as the yield strength ratio (S ratio) and strain hardening exponent ratio (N ratio) between the blanks increases, the maximum load which the blank can sustain without failure (UTS) increases. This becomes constant and comparable to that of single sheet at higher N and S ratios.

  15. Posterior polar cataracts: a predisposition to intraoperative posterior capsular rupture.

    PubMed

    Osher, R H; Yu, B C; Koch, D D

    1990-03-01

    We performed phacoemulsification or planned extracapsular cataract extraction on posterior polar cataracts in 31 eyes of 22 patients and experienced eight cases of posterior capsular rupture (26%). Capsular rupture occurred during removal of the posterior polar opacity or during cleaning of the posterior capsule after the opacity had been removed. We believe that excessive adherence of the opacity to the posterior capsule and unusual thinness of the capsule predisposed these eyes to posterior capsular rupture. PMID:2329471

  16. Rupture of multiple parallel molecular bonds under dynamic loading.

    PubMed

    Seifert, U

    2000-03-20

    Biological adhesion often involves several pairs of specific receptor-ligand molecules. Using rate equations, we study theoretically the rupture of such multiple parallel bonds under dynamic loading assisted by thermal activation. For a simple generic type of cooperativity, both the rupture time and force exhibit several different scaling regimes. The dependence of the rupture force on the number of bonds is predicted to be either linear, like a square root, or logarithmic. PMID:11017316

  17. A Rare Case of Adductor Longus Muscle Rupture

    PubMed Central

    van de Kimmenade, R. J. L. L.; van Bergen, C. J. A.; van Deurzen, P. J. E.; Verhagen, R. A. W.

    2015-01-01

    An adductor longus muscle rupture is a rare injury. This case report describes a 32-year-old patient with an adductor longus rupture. The trauma mechanism was a hyperabduction movement during a soccer game. Nonoperative treatment was initiated. After a follow-up of 4 years, the patient was without pain but a small swelling was still visible. This report describes the anatomy, pathophysiology, and evidence-based treatment of adductor longus rupture. PMID:25918663

  18. [Otogenic brain abscess with rupture into the lateral ventricle].

    PubMed

    Bliouras, K; Skevas, A; Vrettos, X

    1989-07-01

    We present a case of otogenic abscess of the brain that ruptured into the ipsilateral cerebral ventricle. All the diagnostic, surgical and postoperative procedures which led not only to saving this patient but also his complete recovery are described. Because there is a great difference between rupture of a cerebral abscess into a ventricle and rupture of the ventricle into an abscess, particularly with reference to the prognosis, the pathology of the two different complications is reviewed, based on the literature. PMID:2668239

  19. Shear rupture of a directionally solidified eutectic gamma/gamma-prime - alpha /Mo/ alloy. [for aircraft engine turbine blades

    NASA Technical Reports Server (NTRS)

    Harf, F. H.

    1978-01-01

    Directionally solidified gamma/gamma-prime - alpha (Mo) eutectic alloys are being evaluated for application as advanced aircraft engine turbine blades. Their excellent high-temperature strength is partly due to their directionally aligned microstructure. However, alloys with such directional structures may display low shear strength at 760 C, the operating temperature of advanced blade roots. The objective of this investigation was to determine the shear rupture strength of the gamma/gamma-prime - alpha eutectic alloy and possibly to improve it by microstructural and heat-treatment variations. Bars of gamma/gamma-prime - alpha alloy containing nominally 5.7% Al and 33.5% Mo by weight with balance Ni were directionally solidified at rates between 10 and 100 mm per hour. Materials were solidified in furnaces with thermal gradients at the liquid-solid interface of 250 or 100 C per cm. A limited number of longitudinal shear rupture tests were conducted at 760 C and 207 MPa in the as-solidified and in several heat-treated conditions. It was found that the shear rupture failures are partly transgranular and that resistance to failure is promoted by good fiber alignment and a matrix structure consisting mainly of gamma-prime. Well-aligned as-solidified specimens sustained the shear stress for an average of 81 hours, while cellular material failed in one hour or less.

  20. Augmented Repair of Acute Achilles Tendon Rupture Using an Allograft Tendon Weaving Technique.

    PubMed

    Huang, Xiaowei; Huang, Gan; Ji, Ying; Ao, Rong Guang; Yu, Baoqing; Zhu, Ya Long

    2015-01-01

    Achilles tendon rupture is a common injury, especially in those who are physically active. Although open surgery is a widely used option for the treatment of acute Achilles tendon rupture, the optimal treatment is still disputed. In our study, 59 patients with unilateral, closed, acute rupture of the Achilles tendon were treated by open surgery using an allograft weave to augment the repair. All the surgeries were performed within 1 to 4 days after injury. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was recorded as 91.20 (range 88 to 95), 95.34 (range 92 to 98), and 98.27 (range 97 to 99) at the 3-, 6-, and 12-month follow-up visit, respectively. At the final follow-up visit, the mean difference between the mid-calf circumference of the injured and uninjured legs was 0.19 (range -0.03 to 1.50) cm (p = .43). At the final follow-up visit, the mean difference between the vertical distances from the plantar surface of the heel to the ground for the injured and uninjured lower extremities was 0.44 (range -0.03 to 0.5) cm (p = .17). Augmented repair using the allograft tendon weaving technique provided satisfactory tendon strength and functional outcomes and a timely return to the patients' activities. PMID:26015299

  1. [Successive ruptures of patellar and Achilles tendons. Anabolic steroids in competitive sports].

    PubMed

    Isenberg, J; Prokop, A; Skouras, E

    2008-01-01

    Derivatives of testosterone or of 19-nor-testosterone are used as anabolics for the purpose of improving performance although the effect of anabolics is known still to be under discussion. The use of anabolic steroids continues among competitive athletes despite increased controls and increasingly frequent dramatic incidents connected with them. Whereas metabolic dysfunction during anabolic use is well documented, ruptures of the large tendons are rarely reported. Within 18 months, a 29-year-old professional footballer needed surgery for rupture of the patellar tendon and of both Achilles tendons. Carefully directed questioning elicited confirmation that he had taken different anabolic steroids regularly for 3 years with the intention of improving his strength. After each operation anabolic steroids were taken again at a high dosage during early convalescence and training. Minimally invasive surgery and open suturing techniques led to complete union of the Achilles tendons in good time. Training and anabolic use (metenolon 300 mg per week) started early after suturing of the patellar tendon including bone tunnels culminated in histologically confirmed rerupture after 8 weeks. After a ligament reconstruction with a semitendinosus tendon graft with subsequent infection, the tendon and reserve traction apparatus were lost. Repeated warnings of impaired healing if anabolic use was continued had been given without success. In view of the high number of unrecorded cases in competitive and athletic sports, we can assume that the use of anabolic steroids is also of quantitative relevance in the operative treatment of tendon ruptures. PMID:17701152

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

    NASA Technical Reports Server (NTRS)

    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.

  3. Rupture process for micro-earthquakes inferred from borehole seismic recordings

    NASA Astrophysics Data System (ADS)

    Taira, Taka'aki; Dreger, Douglas S.; Nadeau, Robert M.

    2015-09-01

    We investigate the spatial extent of rupture and variability in fault slip for micro-earthquakes by inverting seismic moment rate functions derived from empirical Green's function deconvolution. By using waveforms from an array of borehole seismometers, we determine the spatial distributions of fault slip for M 3+ earthquakes that occurred along the Hayward fault in central California and identify a variety of slip behaviors including subevents, directivity, and high stress drop. The 2013 M w 3.2 Orinda earthquake exhibits a complex rupture process involving two subevents with northwest and up-dip directivity. The two subevents release 43 and 18 % of the total seismic moment (6.7 × 1013 N m), and their inferred peak stress drops are 18 and 8 MPa. The 2011 M w 4.0 Berkeley and 2012 M w 4.0 El Cerrito earthquakes are marked by high stress drop. The inferred peak and mean stress drops are about 100-130 and 40 MPa, respectively, which suggests that there are locally high levels of fault strength on the Hayward fault. Our finite-source modeling suggests that the radiation efficiency determined for these two earthquakes is very low (<0.1) and implies that most energy is dissipated during the earthquake rupture process.

  4. Dynamic stress changes during earthquake rupture

    USGS Publications Warehouse

    Day, S.M.; Yu, G.; Wald, D.J.

    1998-01-01

    We assess two competing dynamic interpretations that have been proposed for the short slip durations characteristic of kinematic earthquake models derived by inversion of earthquake waveform and geodetic data. The first interpretation would require a fault constitutive relationship in which rapid dynamic restrengthening of the fault surface occurs after passage of the rupture front, a hypothesized mechanical behavior that has been referred to as "self-healing." The second interpretation would require sufficient spatial heterogeneity of stress drop to permit rapid equilibration of elastic stresses with the residual dynamic friction level, a condition we refer to as "geometrical constraint." These interpretations imply contrasting predictions for the time dependence of the fault-plane shear stresses. We compare these predictions with dynamic shear stress changes for the 1992 Landers (M 7.3), 1994 Northridge (M 6.7), and 1995 Kobe (M 6.9) earthquakes. Stress changes are computed from kinematic slip models of these earthquakes, using a finite-difference method. For each event, static stress drop is highly variable spatially, with high stress-drop patches embedded in a background of low, and largely negative, stress drop. The time histories of stress change show predominantly monotonic stress change after passage of the rupture front, settling to a residual level, without significant evidence for dynamic restrengthening. The stress change at the rupture front is usually gradual rather than abrupt, probably reflecting the limited resolution inherent in the underlying kinematic inversions. On the basis of this analysis, as well as recent similar results obtained independently for the Kobe and Morgan Hill earthquakes, we conclude that, at the present time, the self-healing hypothesis is unnecessary to explain earthquake kinematics.

  5. [SURGICAL TREATMENT OF PATIENTS WITH URETERAL RUPTURES].

    PubMed

    Komjakov, B K; Guliev, B G

    2015-01-01

    The aim of the study was to analyze the causes of ureteral ruptures and the types surgical procedures used for their management. Over the period from 2006 to 2014, 7 patients with ureteral ruptures underwent surgical treatment in the Mechnikov N-WSMU clinic. All of them were males aged 50 to 71 years. In all cases, the ureter was injured during ureteroscopy and contact lithotripsy. In two patients the right ureter was cut off at the border of the upper and middle third, in four--at 3-4 cm below pyeloureteral segment, one patient diagnosed with a complete separation of the ureter from the kidney pelvis. Patients, who have suffered a detachment of the ureter in other hospitals, previously underwent surgical exploration of the retroperitoneal space, drainage of the kidney by pyelonephrostomy (5) and ureterocutaneostomy (1). In a case of a patient with an injury that occurred in our clinic, laparoscopic nephrectomy with autologous renal transplantation was carried out. Five patients with extended ureter defects underwent ileo-ureteroplasty. The patient with left ureterocutaneostomy underwent nephrovesical bypass. Patency of the upper urinary tract and kidney function were restored in all patients, all of them were relieved from external drains. The duration of the intestinal plastic averaged 160 minutes, laparoscopic nephrectomy with autologous transplantation--210 min and nephrovesical bypass--110 min. Blood transfusion was required only in autologous graft patient. The ureteral rupture is a serious complication of ureteral endourological procedures in upper urinary tract. It requires such complicated reconstructive operations as autologous transplantation of the kidney or intestinal ureteroplasty. PMID:26390553

  6. Isolated ruptures of the supraspinatus muscle.

    PubMed

    Holibka, Radomír; Ditmar, Rudolf; Holibková, Alzbeta; Laichman, Stanislav; R?zicková, Katherine

    2003-12-01

    We rarely encounter isolated ruptures of the supraspinatus muscle. At the Clinic of Orthopedics at the Faculty Hospital in Olomouc, we encountered only 21 cases out of 385 arthroscopic operation cases from October 1998 to October 2003. The patients were examined by USG, 5 patients were examined arthrographically and 3 patients underwent MRI examination. Of these 21 patients, only 3 were operated for acute post-injury haemarthrosis of the shoulder joint. During arthroscopic operation, an isolated rupture of the supraspinatus muscle was discovered in all these patients. The remaining 40 patients were only treated at our clinic for problems associated with impingement syndrome after an interval of 3-11 months and were indicated for operational therapy for the rupture of the supraspinatus muscle, verified sonographically and by MRI. Surgically we performed end to end sutures in 12 patients, in 9 cases we performed refixation using 1-2 titanium MITEK anchors. We supplemented the work by a detailed anatomical study of the supraspinatus muscle on 27 cadaverous anatomical preparations. It was noted that the supraspinatus muscle may be divided into three parts, with a superficial and deep layer of muscle fascicles. An aponeurotic insertion tendon runs through the center, to which part of the superficial muscle fascicles are attached. The muscle fascicles, including the central attachment tendon, run across the superior margin of the shoulder joint and by broad tendon are attached to the superior surface of the greater tubercle of the humerus. Together with the long head of the biceps muscle, they act as a significant shoulder stabiliser. The authors believe that due to the course of the muscle fascicles, this muscle acts as a significant shoulder stabiliser and a powerful abductor and elevator in the shoulder joint. The inferior portion of the muscle fascicles acts as an external rotator of the shoulder. PMID:15037909

  7. Mechanisms of plaque formation and rupture.

    PubMed

    Bentzon, Jacob Fog; Otsuka, Fumiyuki; Virmani, Renu; Falk, Erling

    2014-06-01

    Atherosclerosis causes clinical disease through luminal narrowing or by precipitating thrombi that obstruct blood flow to the heart (coronary heart disease), brain (ischemic stroke), or lower extremities (peripheral vascular disease). The most common of these manifestations is coronary heart disease, including stable angina pectoris and the acute coronary syndromes. Atherosclerosis is a lipoprotein-driven disease that leads to plaque formation at specific sites of the arterial tree through intimal inflammation, necrosis, fibrosis, and calcification. After decades of indolent progression, such plaques may suddenly cause life-threatening coronary thrombosis presenting as an acute coronary syndrome. Most often, the culprit morphology is plaque rupture with exposure of highly thrombogenic, red cell-rich necrotic core material. The permissive structural requirement for this to occur is an extremely thin fibrous cap, and thus, ruptures occur mainly among lesions defined as thin-cap fibroatheromas. Also common are thrombi forming on lesions without rupture (plaque erosion), most often on pathological intimal thickening or fibroatheromas. However, the mechanisms involved in plaque erosion remain largely unknown, although coronary spasm is suspected. The calcified nodule has been suggested as a rare cause of coronary thrombosis in highly calcified and tortious arteries in older individuals. To characterize the severity and prognosis of plaques, several terms are used. Plaque burden denotes the extent of disease, whereas plaque activity is an ambiguous term, which may refer to one of several processes that characterize progression. Plaque vulnerability describes the short-term risk of precipitating symptomatic thrombosis. In this review, we discuss mechanisms of atherosclerotic plaque initiation and progression; how plaques suddenly precipitate life-threatening thrombi; and the concepts of plaque burden, activity, and vulnerability. PMID:24902970

  8. Intracranial Aneurysms: Wall Motion Analysis for Prediction of Rupture.

    PubMed

    Vanrossomme, A E; Eker, O F; Thiran, J-P; Courbebaisse, G P; Zouaoui Boudjeltia, K

    2015-10-01

    Intracranial aneurysms are a common pathologic condition with a potential severe complication: rupture. Effective treatment options exist, neurosurgical clipping and endovascular techniques, but guidelines for treatment are unclear and focus mainly on patient age, aneurysm size, and localization. New criteria to define the risk of rupture are needed to refine these guidelines. One potential candidate is aneurysm wall motion, known to be associated with rupture but difficult to detect and quantify. We review what is known about the association between aneurysm wall motion and rupture, which structural changes may explain wall motion patterns, and available imaging techniques able to analyze wall motion. PMID:25929878

  9. Rupture velocity inferred from near-field shear strain analysis

    NASA Astrophysics Data System (ADS)

    Causse, M.; Cornou, C.; Bécasse, J.

    2014-12-01

    We propose a new technique to determine the rupture velocity of large strike slip earthquakes. By means of simple numerical ground motion simulations, we show that when the rupture penetrates a shallow layer of sediment or fractured rock, shock waves propagate along the surface fault trace in the forward rupture direction. Such shock waves, which are insensitive to the complexity of slip over the fault plane, propagate at a phase velocity equal to the rupture speed. We show that those shock waves can be easily isolated in the frequency domain, and that phase velocity can then be simply obtained from shear strain.

  10. Stress rupture resistance. [of Co and Ni superalloys

    NASA Technical Reports Server (NTRS)

    Freche, J. C.

    1976-01-01

    Principles underlying the design of metallic systems for stress rupture resistance are outlined by considering the specific case studies of cobalt- and nickel-base superalloys. Ways in which superalloys can be designed for high stress rupture resistance are discussed. In describing the alloying procedures, the strengthening mechanisms involved and methods of avoiding phases detrimental to stress rupture resistance are identified. New processing techniques such as controlled solidification, prealloyed powder processing, and autoclave heat treatments are described as further means of achieving increased stress rupture resistance in superalloy and other systems.

  11. Complex earthquake rupture and local tsunamis

    USGS Publications Warehouse

    Geist, E.L.

    2002-01-01

    In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occuring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (N = 100) of synthetic slip distribution patterns, all with identical seismic moment (Mw = 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a factor of 3 or more. These results indicate that there is substantially more variation in the local tsunami wave field derived from the inherent complexity subduction zone earthquakes than predicted by a simple elastic dislocation model. Probabilistic methods that take into account variability in earthquake rupture processes are likely to yield more accurate assessments of tsunami hazards.

  12. Rupture history of the 2008 Mw 7.9 Wenchuan, China, earthquake: Evaluation of separate and joint inversions of geodetic, teleseismic, and strong-motion data

    USGS Publications Warehouse

    Hartzell, Stephen; Mendoza, Carlos; Ramírez-Guzmán, Leonardo; Zeng, Yuesha; Mooney, Walter

    2013-01-01

    earthquake. A linear multiple-time-window approach is used to parameterize the rupture. Because of the complexity of the Wenchuan faulting, three separate planes are used to represent the rupturing surfaces. This earthquake clearly demonstrates the strengths and limitations of geodetic, teleseismic, and strong-motion data sets. Geodetic data (static offsets) are valuable for determining the distribution of shallower slip but are insensitive to deeper faulting and reveal nothing about the timing of slip. Teleseismic data in the distance range 30°–90° generally involve no modeling difficulties because of simple ray paths and can distinguish shallow from deep slip. Teleseismic data, however, cannot distinguish between different slip scenarios when multiple fault planes are involved because steep takeoff angles lead to ambiguity in timing. Local strong-motion data, on the other hand, are ideal for determining the direction of rupture from directivity but can easily be over modeled with inaccurate Green’s functions, leading to misinterpretation of the slip distribution. We show that all three data sets are required to give an accurate description of the Wenchuan rupture. The moment is estimated to be approximately 1:0×1021 N · m with the slip characterized by multiple large patches with slips up to 10 m. Rupture initiates on the southern end of the Pengguan fault and proceeds unilaterally to the northeast. Upon reaching the cross-cutting Xiaoyudong fault, rupture of the adjacent Beichuan fault starts at this juncture and proceeds bilaterally to the northeast and southwest.

  13. Dynamic earthquake rupture simulation on nonplanar faults embedded in 3D geometrically complex, heterogeneous Earth models

    NASA Astrophysics Data System (ADS)

    Duru, K.; Dunham, E. M.; Bydlon, S. A.; Radhakrishnan, H.

    2014-12-01

    Dynamic propagation of shear ruptures on a frictional interface is a useful idealization of a natural earthquake.The conditions relating slip rate and fault shear strength are often expressed as nonlinear friction laws.The corresponding initial boundary value problems are both numerically and computationally challenging.In addition, seismic waves generated by earthquake ruptures must be propagated, far away from fault zones, to seismic stations and remote areas.Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods.We present a numerical method for:a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration;b) dynamic propagation of earthquake ruptures along rough faults; c) accurate propagation of seismic waves in heterogeneous media with free surface topography.We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts finite differences in space. The finite difference stencils are 6th order accurate in the interior and 3rd order accurate close to the boundaries. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. Time stepping is performed with a 4th order accurate explicit low storage Runge-Kutta scheme. We have performed extensive numerical experiments using a slip-weakening friction law on non-planar faults, including recent SCEC benchmark problems. We also show simulations on fractal faults revealing the complexity of rupture dynamics on rough faults. We are presently extending our method to rate-and-state friction laws and off-fault plasticity.

  14. The repetition of large-earthquake ruptures.

    PubMed Central

    Sieh, K

    1996-01-01

    This survey of well-documented repeated fault rupture confirms that some faults have exhibited a "characteristic" behavior during repeated large earthquakes--that is, the magnitude, distribution, and style of slip on the fault has repeated during two or more consecutive events. In two cases faults exhibit slip functions that vary little from earthquake to earthquake. In one other well-documented case, however, fault lengths contrast markedly for two consecutive ruptures, but the amount of offset at individual sites was similar. Adjacent individual patches, 10 km or more in length, failed singly during one event and in tandem during the other. More complex cases of repetition may also represent the failure of several distinct patches. The faults of the 1992 Landers earthquake provide an instructive example of such complexity. Together, these examples suggest that large earthquakes commonly result from the failure of one or more patches, each characterized by a slip function that is roughly invariant through consecutive earthquake cycles. The persistence of these slip-patches through two or more large earthquakes indicates that some quasi-invariant physical property controls the pattern and magnitude of slip. These data seem incompatible with theoretical models that produce slip distributions that are highly variable in consecutive large events. Images Fig. 3 Fig. 7 Fig. 9 PMID:11607662

  15. Ruptured aneurysms of the sinus of Valsalva.

    PubMed

    Mayer, E D; Ruffmann, K; Saggau, W; Butzmann, B; Bernhardt-Mayer, K; Schatton, N; Schmitz, W

    1986-07-01

    From 1964 to 1984, 10 male and 5 female patients with ruptured aneurysms of the sinus of Valsalva (ASVs) underwent surgical correction. These procedures constituted 0.23% of the 6,350 surgical procedures that used cardiopulmonary bypass during this period. Five patients had an inflammatory condition (bacterial endocarditis, 4; syphilis, 1), and 1 had an ASV relapse 5 years after her first operation. Coexistent lesions included aortic valve regurgitation in 5 patients, ventricular septal defect in 3 (1 of whom had mitral insufficiency), patent foramen ovale in 2, and atrial septal defect in 1. Ninety-three percent were symptomatic (sudden onset of symptoms, 5 patients; gradual onset, 9 patients), commonly with shortness of breath, fatigability, chest pain, and tachycardia. The following connections occurred: noncoronary sinus to right atrium (RA) (5 patients); right coronary sinus (RCS) to RA (5 patients); and RCS to right ventricle (5 patients). There were no early or late postoperative deaths. One patient underwent reoperation after an ASV relapse. The mean follow-up period (+/- standard deviation) was 7.9 years (range, 10 months to 20.1 years). Eighty percent of the patients were found to be in New York Heart Association class I, and 20% were in class II. Apart from ASV relapse, late complications are determined by prosthetic valve dysfunction or evidence of valve disease. Early surgical intervention is justified in patients with ruptured ASV. PMID:3729620

  16. TMI-2 lower head creep rupture analysis

    SciTech Connect

    Thinnes, G.L.

    1988-08-01

    The TMI-2 accident resulted in approximately 40% of the reactor's core melting and collecting on the lower head of the reactor pressure vessel. The severity of the accident has raised questions about the margin of safety against rupture of the lower head in this accident since all evidence seems to indicate no major breach of the vessel occurred. Scoping heat transfer analyses of the relocated core debris and lower head have been made based upon assumed core melting scenarios and core material debris formations while in contact with the lower head. This report describes the structural finite element creep rupture analysis of the lower head using a temperature transient judged most likely to challenge the structural capacity of the vessel. This evaluation of vessel response to this transient has provided insight into the creep mechanisms of the vessel wall, a realistic mode of failure, and a means by which margin to failure can be evaluated once examination provides estimated maximum wall temperatures. Suggestions for more extensive research in this area are also provided. 6 refs., 15 figs.

  17. False vs True rupture of membranes.

    PubMed

    Cohain, J S

    2015-05-01

    New medical nomenclature: False rupture of membranes or False ROM and Double rupture of membranes or Double ROM are being introduced into the English language. A single caregiver found about 1% of term births and 10% of term PROM involved False ROM, in which the chorion breaks while the amnion remains intact. Diagnostically, if meconium or vernix is observed, then both the chorionic and amniotic sacs have broken. In the absence of detection of vernix or meconium, an immediate accurate diagnostic test for False ROM is lacking and differentiating between True ROM from False ROM is possible only after leaking stops, which takes hours to days. The obvious benefit of differentiating between 'True' and 'False' ROM, is that in the case of False ROM, the amnion is intact and ascending infections are likely not at increased risk, although research is lacking as to whether False ROM is associated with an increased rate of ascending infection. Three cases of False ROM are presented and avenues for future research are enumerated. PMID:25279443

  18. High strength nickel-chromium-iron austenitic alloy

    DOEpatents

    Gibson, Robert C. (Ringwood, NJ); Korenko, Michael K. (Richland, WA)

    1980-01-01

    A solid solution strengthened Ni-Cr-Fe alloy capable of retaining its strength at high temperatures and consisting essentially of 42 to 48% nickel, 11 to 13% chromium, 2.6 to 3.4% niobium, 0.2 to 1.2% silicon, 0.5 to 1.5% vanadium, 2.6 to 3.4% molybdenum, 0.1 to 0.3% aluminum, 0.1 to 0.3% titanium, 0.02 to 0.05% carbon, 0.002 to 0.015% boron, up to 0.06 zirconium, and the balance iron. After solution annealing at 1038.degree. C. for one hour, the alloy, when heated to a temperature of 650.degree. C., has a 2% yield strength of 307 MPa, an ultimate tensile strength of 513 MPa and a rupture strength of as high as 400 MPa after 100 hours.

  19. Dynamic path selection along branched faults: Experiments involving sub-Rayleigh and supershear ruptures

    E-print Network

    Rosakis, Ares J.

    ruptures Carl-Ernst Rousseau1 and Ares J. Rosakis2 Received 27 October 2008; revised 12 March 2009 of rupture propagation along a branch by the Mach cone, when the initial rupture is supershear driven

  20. The Utility of Bedside Ultrasound in the Detection of a Ruptured Globe in a Porcine Model

    E-print Network

    Chandra, Amit; Mastrovitch, Todd; Ladner, Heidi; Ting, Vincent; Radeos, Michael S; Samudre, Sandeep

    2009-01-01

    identify abnormal eyes with a sensitivity of 79% (95% CI 73%eye,” rupture Identification of a or vitrectomy (CI) ruptured globe (CI) 1st Year Resident Sensitivityeye as a vitrectomy or a CVL as a rupture. The sensitivity

  1. Kinesthetic Transverse Wave Demonstration

    NASA Astrophysics Data System (ADS)

    Pantidos, Panagiotis; Patapis, Stamatis

    2005-09-01

    This is a variation on the String and Sticky Tape demonstration "The Wave Game," suggested by Ron Edge. A group of students stand side by side, each one holding a card chest high with both hands. The teacher cues the first student to begin raising and lowering his card. When he starts lowering his card, the next student begins to raise his. As succeeding students move their cards up and down, a wave such as that shown in the figure is produced. To facilitate the process, students' motions were synchronized with the ticks of a metronome (without such synchronization it was nearly impossible to generate a satisfactory wave). Our waves typically had a frequency of about 1 Hz and a wavelength of around 3 m. We videotaped the activity so that the students could analyze the motions. The (17-year-old) students had not received any prior instruction regarding wave motion and did not know beforehand the nature of the exercise they were about to carry out. During the activity they were asked what a transverse wave is. Most of them quickly realized, without teacher input, that while the wave propagated horizontally, the only motion of the transmitting medium (them) was vertical. They located the equilibrium points of the oscillations, the crests and troughs of the waves, and identified the wavelength. The teacher defined for them the period of the oscillations of the motion of a card to be the total time for one cycle. The students measured this time and then several asserted that it was the same as the wave period. Knowing the length of the waves and the number of waves per second, the next step can easily be to find the wave speed.

  2. Human Fetal Membranes: Their Preterm Premature Rupture1 [Create Reference

    E-print Network

    Bryant-Greenwood, Gillian D.

    Human Fetal Membranes: Their Preterm Premature Rupture1 [Create­1579. Human Fetal Membranes: Their Preterm Premature Rupture1 Gillian D. Bryant-Greenwood, a, 2 and Lynnae K. Millar a aPacific Biomedical Research Center, University of Hawaii, Honolulu, Hawaii 96822 Manuscript

  3. Isolated rupture of teres major in a goalkeeper.

    PubMed

    Maciel, Rafael Almeida; Zogaib, Rodrigo Kallas; Pochini, Alberto De Castro; Ejnisman, Benno

    2015-01-01

    A complete rupture of the teres major is an extremely rare injury and rarely described in the literature. We report the first case of an isolated rupture of the teres major in a professional football goalkeeper. The diagnosis requires a high degree of suspicion and complementation by image examinations. Conservative treatment has a high success rate with early return to sport. PMID:26701915

  4. Non-bleeding Spontaneous Rupture of Hepatocellular Carcinoma.

    PubMed

    Islam, Mahibul; Deka, Pranjal; Kapur, Raj; Ansari, Md Abu Masud

    2013-07-01

    Rupture of hepatocellular carcinoma (HCC) is not uncommon and most ruptured HCC present with hemoperitoneum and hemorrhagic shock. Management of ruptured HCC is different than non-ruptured one. Short- and long-term mortality increases following rupture of HCC with increasing chances of tumor dissemination. We describe a case with non-bleeding spontaneous rupture of HCC. A 62-year-old male patient was admitted to our institute hospital with mild to moderate pain in the right upper part of the abdomen. He lost appetite and weight. Ultrasonography of the abdomen was performed and it suggested HCC and ascites. Triple phase computer tomography revealed HCC in segments 6 and 7 of liver with typical radiological characteristics. Portal vein was thrombosed. No extravasation of dye was seen. Ruptured of tumor through liver capsule was seen with necrosis and hemorrhage in the center of the tumor. Non-bleeding ruptured HCC has not been reported in the literature to the best of our knowledge. We herein describe this rare case. PMID:24497757

  5. Non-bleeding Spontaneous Rupture of Hepatocellular Carcinoma

    PubMed Central

    Islam, Mahibul; Deka, Pranjal; Kapur, Raj; Ansari, Md. Abu Masud

    2013-01-01

    Rupture of hepatocellular carcinoma (HCC) is not uncommon and most ruptured HCC present with hemoperitoneum and hemorrhagic shock. Management of ruptured HCC is different than non-ruptured one. Short- and long-term mortality increases following rupture of HCC with increasing chances of tumor dissemination. We describe a case with non-bleeding spontaneous rupture of HCC. A 62-year-old male patient was admitted to our institute hospital with mild to moderate pain in the right upper part of the abdomen. He lost appetite and weight. Ultrasonography of the abdomen was performed and it suggested HCC and ascites. Triple phase computer tomography revealed HCC in segments 6 and 7 of liver with typical radiological characteristics. Portal vein was thrombosed. No extravasation of dye was seen. Ruptured of tumor through liver capsule was seen with necrosis and hemorrhage in the center of the tumor. Non-bleeding ruptured HCC has not been reported in the literature to the best of our knowledge. We herein describe this rare case. PMID:24497757

  6. Spleen rupture in course of chronic pancreatitis. A case report.

    PubMed

    Luck, O D; Juhl-Jensen, V

    1990-01-01

    Non-traumatic spleen rupture is exceedingly rare. We report case, in which an occlusion of the pancreatic duct induced a fistula from the pancreatic tail to the spleen coursing enzymatic digestion resulting in subcapsular bleeding and rupture of the spleen. The pathogenesis is discussed. PMID:2131568

  7. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    PubMed Central

    Nesselroade, Ryan D.; Nickels, Leslie Connor

    2010-01-01

    Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors. The diagnosis was confirmed using bedside ultrasound. PMID:21079697

  8. 2342 Biophysical Journal Volume 85 October 2003 23422350 Dynamic Tension Spectroscopy and Strength of Biomembranes

    E-print Network

    Heinrich, Volkmar

    membranes to rupture at tensions near hydrocarbon-water surface tension (so/w ; 40 mN/m) by analogy to the disappearance of surface pressure in a lipid monolayer under large expansion at an oil/water interface. However2342 Biophysical Journal Volume 85 October 2003 2342­2350 Dynamic Tension Spectroscopy and Strength

  9. Stainless steels with improved strength for service at 760 C and above

    SciTech Connect

    Swindeman, R.W.

    1998-03-01

    An evaluation was undertaken of modified 25Cr-20Ni stainless steels and a modified 20Cr-25Ni-Nb stainless steel for advanced energy applications at 760 C (1,400 F) and higher. It was found that good fabricability, strength, and ductility could be produced in the modified steels. Stress rupture data to beyond 10,000 h showed that the strengths of the modified steels were more than double that for type 310H stainless steel.

  10. A Three Year Clinicopathological Study of Cases of Rupture Uterus

    PubMed Central

    Rathod, Setu; Swain, Sujata

    2015-01-01

    Introduction Rupture uterus is a life threatening obstetric complication with serious maternal and fetal side-effects. We report a 3 year (2010-2013) retrospective clinical study of pregnancy with rupture uterus cases attending a tertiary care hospital. Aim The aim of the study was to evaluate the incidence of rupture uterus, incidence as per age, parity, clinical presentations, risk factors, complications and management. Materials and Methods Retrospective data of 74 cases of rupture uterus in SCB Medical college, Cuttack was collected from case records of 26,547 deliveries during a 3 year span (2010-2013). Parameters like cause of rupture, type, site of rupture and outcome were recorded. The collected data was analysed by SPSS software v19. Results Out of 26,547 deliveries during the three year period, there were 74 cases of rupture uterus with an incidence of rupture 1 in 359 (0.28%). The mean age of rupture uterus was 27.4 years. 95.8% were multigravida and majority were referred cases from low socioeconomic status. Only 40.5% had the required minimum of four antenatal visits as recommended by WHO (World Health Organisation). A total of 48.6% of cases with rupture uterus had history of previous Caesarean section. Prolonged labour was present in 75.6% of the cases. Only 12.2% of the cases had history of oxytocin use whereas 9.5% had undergone an operative vaginal delivery. Obstructed labour was the cause in 24.3% of cases, 85.1% had complete rupture. Majority had a rupture in the anterior wall (69%) and 81.1% had rupture in lower segment of uterus. Only 17.6% had broad ligament haematoma, 10.8% colporrhexis and 6.8% had associated bladder injury. Repair was possible in only 39.2% of cases, whereas majority landed up in hysterectomy. Internal iliac ligation was done in 2.7% of cases. Perinatal mortality was 90.5% whereas maternal death was seen in 13.5% cases. One patient developed VVF (vesicovaginal fistula). Duration of hospital stay was upto 14 days in 81.1% cases. Conclusion Education and proper care especially of high risk patients like previous caesarean by competent personnal, proper use of oxytocin and early referral may help to reduce the incidence of “rupture uterus”. PMID:26673858

  11. Relaxing Segmentation: Does It Improve Characterization of Fault Rupture Behavior?

    NASA Astrophysics Data System (ADS)

    Schwartz, D. P.

    2014-12-01

    Most faults have not ruptured once historically, let alone repeatedly. Estimating future rupture length of an earthquake source has been a challenge since the 1970s when concepts of full and half fault lengths were employed. In the 1980s paleoseismic event timing and observations of slip, coupled with geometric and other physical fault changes, led to concepts of fault segmentation and it's modeling for hazard. The Uniform California Earthquake Rupture Forecast 3 (UCERF 3, Field et al., 2014) relaxed segmentation, guided by rules in which a separation distance of ?5km and orientation to Coulomb stress changes at fault junctions are prime factors for allowing fault-to-fault jumps. A set of ~350 fault sections produced ~250K ruptures ranging in length from 15 km-1200 km. An inversion provided the rates of these, which range from 102-108 years. Many of the long ruptures have exceedingly low individual rates within the UCERF 3 geologic model but are sufficient in number to release cumulative moment that brings the long-term (Myr) and historical (since 1850) MFDs for the California region into close agreement. Does UCERF 3 have too many multi-fault ruptures? Since 1850 there have been ~260 surface ruptures worldwide in shallow continental crust. 77% are 0-49km; 6% exceed 150km, and the longest is 1906 San Francisco (435-470 km). In California since 1857 there have been 31 surface ruptures. 77% are shorter than 49 km. The longest are 1906, 1857 Fort Tejon (297km), and 1872 Owens Valley (108 km). Most long historical strike-slip ruptures are continuous and geomorphically well-defined traces with limited geometric changes. In contrast, UCERF3 modeling of the south Hayward, as an example, allows it to participate in ruptures that extend to the south ends of the San Andreas or San Jacinto faults (900 km). These include branching (Hayward-Calaveras, San Andreas-San Jacinto) and jumps (Calaveras-San Andreas) on creeping sections of these faults. 5km is the connectivity threshold in UCERF 3 but only 40% of historical ruptures have negotiated this distance. There are other controls of rupture propagation: frictional properties, rupture dynamics, creep, and, as shown by the 2002 Denali-Totschunda rupture, the timing of the prior event and level of stress accumulation on adjacent fault sections. Time will be the tester.

  12. Transverse and longitudinal tensile properties at 760 C of several oxide dispersion strenghened nickel-base alloys

    NASA Technical Reports Server (NTRS)

    Anglin, A. E., Jr.

    1979-01-01

    The transverse and longitudinal tensile properties of the oxide dispersion strengthened nickel base alloys MA-793, MA-754, MA-755E, and MA-6000E were determined at 760 C. Transverse tensile strengths were comparable to longitudinal strengths. Transverse ductility levels generally were less than two percent elongation. Both tensile and yield strengths increased with increasing strain rate over the range 0.001 to 0.05 per second. Ductility was not strain rate sensitive, but related to grain size and grain aspect ratio. The fracture mode of most alloys changed from transgranular for longitudinally oriented specimens to intergranular for transverse specimens. Transverse properties of DM MAR M-200 + Hf were also determined for comparison.

  13. The Influence of TiO2 Addition on the Modulus of Rupture of Alumina-Magnesia Refractory Castables

    NASA Astrophysics Data System (ADS)

    Yuan, Wenjie; Deng, Chengji; Zhu, Hongxi

    2015-08-01

    The addition of TiO2 to alumina-magnesia refractory castables could accelerate the in situ spinel and calcium hexa-aluminate (CA6) formation and change the phase evolution, which will have direct effect on the overall modulus of rupture values. The cold (CMOR) and hot (HMOR) modulus of rupture, thermal expansion, and elastic modulus of alumina-magnesia refractory castables with different amounts of TiO2 were measured. The correlation of CMOR, theoretical strength, fracture toughness, and the fractal dimension of the fracture surface for these compositions were investigated. HMOR data were described using the model based on Varshni approach and Adam-Gibbs theory. The influence of TiO2 addition on the modulus of rupture of alumina-magnesia refractory castables was related to microcracks derived from expansive phase formation and pore filling or viscous bridging due to the presence of liquid phase at high temperature. The contribution of the above factors to the modulus of rupture for castables varied with the temperature.

  14. New procedure to record the rupture of bonds between macromolecules and the surface of the quartz crystal microbalance (QCM).

    PubMed

    Dultsev, Fedor N; Kolosovsky, Eugeny A; Mik, Ivan A

    2012-10-01

    It is shown that an increase in the amplitude of QCM shear oscillations during frequency scanning around the resonance frequency is accompanied (at a definite voltage) by distortions in the amplitude-frequency dependence for QCM. We demonstrated that these distortions are connected to the rupture of macromolecules from the QCM surface. It is shown that the identification of the rupture of particles and macromolecules from the QCM surface can be carried out by relying on the analysis of these distortions of the amplitude-frequency dependence. The distortions were distinguished as a signal. The number of broken bonds can be estimated from the value of this distortion signal, and the threshold voltage applied to the system can be used to estimate the rupture force to high accuracy. Using the proposed method, we estimated the strength of a physical bond, which was 3 pN. This procedure can be useful for studying biological objects and represents an advanced step in the development of the REVS (rupture event scanning) technique. PMID:22973802

  15. The effect of electron beam welding on the creep rupture properties of a Nb-Zr-C alloy

    NASA Technical Reports Server (NTRS)

    Moore, T. J.; Titran, R. H.; Grobstein, T. L.

    1986-01-01

    Creep rupture tests of electron beam welded PWC-11 sheet were conducted at 1350 K. Full penetration, single pass welds were oriented transverse to the testing direction in 1 mm thick sheet. With this orientation, stress was imposed equally on the base metal, weld metal, and heat-affected zone. Tests were conducted in both the postweld annealed and aged conditions. Unwelded specimens with similar heat treatments were tested for comparative purposes. It was found that the weld region is stronger than the base metal for both the annealed and aged conditions and that the PWC-11 material is stronger in the annealed condition than in the aged condition.

  16. Material contrast does not predict earthquake rupture propagation direction

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    2005-01-01

    Earthquakes often occur on faults that juxtapose different rocks. The result is rupture behavior that differs from that of an earthquake occurring on a fault in a homogeneous material. Previous 2D numerical simulations have studied simple cases of earthquake rupture propagation where there is a material contrast across a fault and have come to two different conclusions: 1) earthquake rupture propagation direction can be predicted from the material contrast, and 2) earthquake rupture propagation direction cannot be predicted from the material contrast. In this paper we provide observational evidence from 70 years of earthquakes at Parkfield, CA, and new 3D numerical simulations. Both the observations and the numerical simulations demonstrate that earthquake rupture propagation direction is unlikely to be predictable on the basis of a material contrast. Copyright 2005 by the American Geophysical Union.

  17. Spontaneous diaphragmatic rupture related to local invasion by retroperitoneal liposarcoma.

    PubMed

    Pehar, M; Vukoja, I; Rozi?, D; Miškovi?, J

    2012-01-01

    We report a case of the female patient who was admitted to the hospital because of syncope experienced while climbing stairs. Diagnostic workup raised the suspicion of a right diaphragmatic rupture that was eventually confirmed by surgery (right-sided thoracotomy). Surgery also revealed tissue protruding through the rupture site from within the retroperitoneum that was proven subsequently to be a dedifferentiated liposarcoma. Second surgery was performed to completely remove the liposarcoma tissue and repair a coincident old right lumbar region hernia. The patient recovered fully. Spontaneous rupture of the diaphragm is rare and this is especially true for the right hemidiaphragm. We report the first case of diaphragmatic rupture caused by local infiltration by a retroperitoneal liposarcoma. This and similar reports emphasise that in cases with high clinical suspicion of diaphragmatic rupture, diagnosis should be pursued even in the absence of a preceding traumatic event. PMID:22524913

  18. Transversity and Spin Structure Functions

    E-print Network

    H. E. Jackson

    2004-08-24

    Measurements of single-spin asymmetries for semi-inclusive electro-production of pions and kaons in deep-inelastic scattering with transverse target polarization open a new window on the transverse quark and gluon structure of the nucleon. The first experimental results from such measurements as well as experiments in progress are discussed. Properties of the spin-dependent Collins fragmentation function and prospects for extracting the transversity are reviewed and evidence for nonzero Sivers asymmetries as manifestations of quark orbital angular momentum is evaluated.

  19. Macroscopic Source Properties from Dynamic Rupture Styles in Plastic Media

    NASA Astrophysics Data System (ADS)

    Gabriel, A.; Ampuero, J. P.; Dalguer, L. A.; Mai, P. M.

    2011-12-01

    High stress concentrations at earthquake rupture fronts may generate an inelastic off-fault response at the rupture tip, leading to increased energy absorption in the damage zone. Furthermore, the induced asymmetric plastic strain field in in-plane rupture modes may produce bimaterial interfaces that can increase radiation efficiency and reduce frictional dissipation. Off-fault inelasticity thus plays an important role for realistic predictions of near-fault ground motion. Guided by our previous studies in the 2D elastic case, we perform rupture dynamics simulations including rate-and-state friction and off-fault plasticity to investigate the effects on the rupture properties. We quantitatively analyze macroscopic source properties for different rupture styles, ranging from cracks to pulses and subshear to supershear ruptures, and their transitional mechanisms. The energy dissipation due to off-fault inelasticity modifies the conditions to obtain each rupture style and alters macroscopic source properties. We examine apparent fracture energy, rupture and healing front speed, peak slip and peak slip velocity, dynamic stress drop and size of the process and plastic zones, slip and plastic seismic moment, and their connection to ground motion. This presentation focuses on the effects of rupture style and off-fault plasticity on the resulting ground motion patterns, especially on characteristic slip velocity function signatures and resulting seismic moments. We aim at developing scaling rules for equivalent elastic models, as function of background stress and frictional parameters, that may lead to improved "pseudo-dynamic" source parameterizations for ground-motion calculation. Moreover, our simulations provide quantitative relations between off-fault energy dissipation and macroscopic source properties. These relations might provide a self-consistent theoretical framework for the study of the earthquake energy balance based on observable earthquake source parameters.

  20. Strength Training for Girls.

    ERIC Educational Resources Information Center

    Connaughton, Daniel; Connaughton, Angela; Poor, Linda

    2001-01-01

    Strength training can be fun, safe, and appropriate for young girls and women and is an important component of any fitness program when combined with appropriate cardiovascular and flexibility activities. Concerns and misconceptions regarding girls' strength training are discussed, presenting general principles of strength training for children…

  1. Generation of microcracks by dynamic shear rupture and its effects on rupture growth and elastic wave radiation

    E-print Network

    Yamashita, Teruo

    Generation of microcracks by dynamic shear rupture and its effects on rupture growth and elastic propagating earthquake faults generate a large number of tensile microcracks in their vicinity, which waves will also be affected by the generation of microcracks. We numerically study how such tensile

  2. Multifractal scaling of thermally activated rupture processes.

    PubMed

    Sornette, D; Ouillon, G

    2005-01-28

    We propose a "multifractal stress activation" model combining thermally activated rupture and long memory stress relaxation, which predicts that seismic decay rates after mainshocks follow the Omori law approximately 1/t(p) with exponents p linearly increasing with the magnitude M(L) of the mainshock. We carefully test this prediction on earthquake sequences in the Southern California earthquake catalog: we find power law relaxations of seismic sequences triggered by mainshocks with exponents p increasing with the mainshock magnitude by approximately 0.1-0.15 for each magnitude unit increase, from p(M(L) = 3) approximately 0.6 to p(M(L) = 7) approximately 1.1, in good agreement with the prediction of the multifractal model. PMID:15698332

  3. Creep and stress rupture of a mechanically alloyed oxide dispersion and precipitation strengthened nickel-base superalloy

    NASA Technical Reports Server (NTRS)

    Howson, T. E.; Tien, J. K.; Mervyn, D. A.

    1980-01-01

    The creep and stress rupture behavior of a mechanically alloyed oxide dispersion strengthened (ODS) and gamma-prime precipitation strengthened nickel-base alloy (alloy MA 6000E) was studied at intermediate and elevated temperatures. At 760 C, MA 6000E exhibits the high creep strength characteristic of nickel-base superalloys and at 1093 C the creep strength is superior to other ODS nickel-base alloys. The stress dependence of the creep rate is very sharp at both test temperatures and the apparent creep activation energy measured around 760 C is high, much larger in magnitude than the self-diffusion energy. Stress rupture in this large grain size material is transgranular and crystallographic cracking is observed. The rupture ductility is dependent on creep strain rate, but usually is low. These and accompanying microstructural results are discussed with respect to other ODS alloys and superalloys and the creep behavior is rationalized by invoking a recently-developed resisting stress model of creep in materials strengthened by second phase particles.

  4. Strength Modeling Report

    NASA Technical Reports Server (NTRS)

    Badler, N. I.; Lee, P.; Wong, S.

    1985-01-01

    Strength modeling is a complex and multi-dimensional issue. There are numerous parameters to the problem of characterizing human strength, most notably: (1) position and orientation of body joints; (2) isometric versus dynamic strength; (3) effector force versus joint torque; (4) instantaneous versus steady force; (5) active force versus reactive force; (6) presence or absence of gravity; (7) body somatotype and composition; (8) body (segment) masses; (9) muscle group envolvement; (10) muscle size; (11) fatigue; and (12) practice (training) or familiarity. In surveying the available literature on strength measurement and modeling an attempt was made to examine as many of these parameters as possible. The conclusions reached at this point toward the feasibility of implementing computationally reasonable human strength models. The assessment of accuracy of any model against a specific individual, however, will probably not be possible on any realistic scale. Taken statistically, strength modeling may be an effective tool for general questions of task feasibility and strength requirements.

  5. Shigella subverts the host recycling compartment to rupture its vacuole.

    PubMed

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

    2014-10-01

    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)P? 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. PMID:25299335

  6. How does damage affect rupture propagation across a fault stepover?

    NASA Astrophysics Data System (ADS)

    Cooke, M. L.; Savage, H. M.

    2011-12-01

    We investigate the potential for fault damage to influence earthquake rupture at fault step-overs using a mechanical numerical model that explicitly includes the generation of cracks around faults. We compare the off-fault fracture patterns and slip profiles generated along faults with a variety of frictional slip-weakening distances and step-over geometry. Models with greater damage facilitate the transfer of slip to the second fault. Increasing separation and decreasing the overlap distance reduces the transfer of slip across the step over. This is consistent with observations of rupture stopping at step-over separation greater than 4 km (Wesnousky, 2006). In cases of slip transfer, rupture is often passed to the second fault before the damage zone cracks of the first fault reach the second fault. This implies that stresses from the damage fracture tips are transmitted elastically to the second fault to trigger the onset of slip along the second fault. Consequently, the growth of damage facilitates transfer of rupture from one fault to another across the step-over. In addition, the rupture propagates along the damage-producing fault faster than along the rougher fault that does not produce damage. While this result seems counter to our understanding that damage slows rupture propagation, which is documented in our models with pre-existing damage, these model results are suggesting an additional process. The slip along the newly created damage may unclamp portions of the fault ahead of the rupture and promote faster rupture. We simulate the M7.1 Hector Mine Earthquake and compare the generated fracture patterns to maps of surface damage. Because along with the detailed damage pattern, we also know the stress drop during the earthquake, we may begin to constrain parameters like the slip-weakening distance along portions of the faults that ruptured in the Hector Mine earthquake.

  7. Blunt traumatic cardiac rupture. A 5-year experience.

    PubMed Central

    Brathwaite, C E; Rodriguez, A; Turney, S Z; Dunham, C M; Cowley, R

    1990-01-01

    Blunt traumatic cardiac rupture is associated with a high rate of mortality. A review of the computerized trauma registry (1983 to 1988) identified 32 patients with this injury (ages 19 to 65 years; mean age, 39.5 years; 21 men and 11 women). Twenty-one patients (65.6%) were injured in vehicular crashes, 3 (9.4%) in pedestrian accidents, 3 (9.4%) in motorcycle accidents; 3 (9.4%) sustained crush injury; 1 (3.1%) was injured by a fall; and 1 (3.1%) was kicked in the chest by a horse. Anatomic injuries included right atrial rupture (13[40.6%]), left atrial rupture (8 [25%]), right ventricular rupture (10[31.3%]), left ventricular rupture (4[12.5%]), and rupture of two cardiac chambers (3 [9.4%]). Diagnosis was made by thoracotomy in all 20 patients presenting in cardiac arrest. In the remaining 12 patients, the diagnosis was established in seven by emergency left anterolateral thoracotomy and in five by subxyphoid pericardial window. Seven of these 12 patients (58.3%) had clinical cardiac tamponade and significant upper torso cyanosis. The mean Injury Severity Score (ISS), Trauma Score (TS), and Glasgow Coma Scale (GCS) score were 33.8, 13.2, and 14.3, respectively, among survivors and 51.5, 8.3, and 7.0 for nonsurvivors. The overall mortality rate was 81.3% (26 of 32 patients), the only survivors being those presenting with vital signs (6 of 12 patients [50%]). All patients with rupture of two cardiac chambers or with ventricular rupture died. The mortality rate from myocardial rupture is very high. Rapid prehospital transportation, a high index of suspicion, and prompt surgical intervention contribute to survival in these patients. PMID:2256761

  8. Frictional melting during the rupture of the 1994 bolivian earthquake

    PubMed

    Kanamori; Anderson; Heaton

    1998-02-01

    The source parameters of the 1994 Bolivian earthquake (magnitude Mw = 8.3) suggest that the maximum seismic efficiency eta was 0.036 and the minimum frictional stress was 550 bars. Thus, the source process was dissipative, which is consistent with the observed slow rupture speed, only 20% of the local S-wave velocity. The amount of nonradiated energy produced during the Bolivian rupture was comparable to, or larger than, the thermal energy of the 1980 Mount St. Helens eruption and was sufficient to have melted a layer as thick as 31 centimeters. Once rupture was initiated, melting could occur, which reduces friction and promotes fault slip. PMID:9452378

  9. Irradiation creep and creep rupture of titanium-modified austenitic stainless steels and their dependence on cold work level

    SciTech Connect

    Garner, F.A.; Hamilton, M.L.; Eiholzer, C.R.; Toloczko, M.B.; Kumar, A.S.

    1991-11-01

    A titanium-modified austenitic type stainless steel was tested at three cold work levels to determine its creep and creep rupture properties under both thermal aging and neutron irradiation conditions. Both the thermal and irradiation creep behavior exhibit a complex non-monotonic relationship with cold work level that reflects the competition between a number of stress-sensitive and temperature-dependent microstructural processes. Increasing the degree of cold work to 30% from the conventional 20% level was detrimental to its performance, especially for applications above 550{degrees}c. The 20% cold work level is preferable to the 10% level, in terms of both in-reactor creep rupture response and initial strength.

  10. Rupture Synchronicity in Complex Fault Systems

    NASA Astrophysics Data System (ADS)

    Milner, K. R.; Jordan, T. H.

    2013-12-01

    While most investigators would agree that the timing of large earthquakes within a fault system depends on stress-mediated interactions among its elements, much of the debate relevant to time-dependent forecasting has been centered on single-fault concepts, such as characteristic earthquake behavior. We propose to broaden this discussion by quantifying the multi-fault concept of rupture synchronicity. We consider a finite set of small, fault-spanning volumes {Vk} within a fault system of arbitrary (fractal) complexity. We let Ck be the catalog of length tmax comprising Nk discrete times {ti(k)} that mark when the kth volume participates in a rupture of magnitude > M. The main object of our analysis is the complete set of event time differences {?ij(kk') = ti(k) - tj(k')}, which we take to be a random process with an expected density function ?kk'(t). When k = k', we call this function the auto-catalog density function (ACDF); when k ? k', we call it the cross-catalog density function (CCDF). The roles of the ACDF and CCDF in synchronicity theory are similar to those of autocorrelation and cross-correlation functions in time-series analysis. For a renewal process, the ACDF can be written in terms of convolutions of the interevent-time distribution, and many of its properties (e.g., large-t asymptote) can be derived analytically. The interesting information in the CCDF, like that in the ACDF, is concentrated near t = 0. If two catalogs are completely asynchronous, the CCDF collapses to an asymptote given by the harmonic mean of the ACDF asymptotes. Synchronicity can therefore be characterized by the variability of the CCDF about this asymptote. The brevity of instrumental catalogs makes the identification of synchronicity at large M difficult, but we will illustrate potentially interesting behaviors through the analysis of a million-year California catalog generated by the earthquake simulator, RSQSim (Deiterich & Richards-Dinger, 2010), which we sampled at a dozen fault-spanning volumes. At the magnitude threshold M = 7, the ACDF can be well fit by renewal models with fairly small aperiodicity parameters (? < 0.2) for all fault volumes but one (on the San Jacinto fault). At interseismic (Reid) time scales, we observe pairs of fault segments that are tightly locked, such as the Cholame and Carrizo sections of the San Andreas Fault (SAF), where the CCDF and two ACDFs are nearly equal; segments out of phase (Carrizo-SAF/Coachella-SAF and Coachella-SAF/San Jacinto), where the CCDF variation is an odd function of time; and segments where events are in phase with integer ratios of recurrence times (2:1 synchronicity of Coachella-SAF/Mojave-SAF and Carrizo-SAF/Mojave-SAF). At near-seismic (Omori) time scales, we observe various modes of clustering, triggering, and shadowing in RSQSim catalogs; e.g., events on Mojave-SAF trigger Garlock events, and events on Coachella-SAF shut down events on San Jacinto. Therefore, despite its geometrical complexity and multiplicity of time scales, the RSQSim model of the San Andreas fault system exhibits a variety of synchronous behaviors that increase the predictability of large ruptures within the system. A key question for earthquake forecasting is whether the real San Andreas system is equally, or much less, synchronous.

  11. Isokinetic muscle assessment after treatment of pectoralis major muscle rupture using surgical or non-surgical procedures

    PubMed Central

    Fleury, Anna Maria; da Silva, Antonio Carlos; de Castro Pochini, Alberto; Ejnisman, Benno; de Lira, Claudio Andre Barbosa; dos Santos Andrade, Marilia

    2011-01-01

    INTRODUCTION: Rupture of the pectoralis major muscle appears to be increasing in athletes. However, the optimal treatment strategy has not yet been established. OBJECTIVES: To compare the isokinetic shoulder performance after surgical treatment to that after non-surgical treatment for pectoralis major muscle rupture. METHODS: We assessed 33 pectoralis major muscle ruptures (18 treated non-surgically and 15 treated surgically). Horizontal abduction and adduction as well as external and internal rotation at 60 and 120 degrees/s were tested in both upper limbs. Peak torque, total work, contralateral deficiency, and the peak torque agonist-to-antagonist ratio were measured. RESULTS: Contralateral muscular deficiency did not differ between the surgical and non-surgical treatment modalities. However, the surgical group presented twice the number of athletes with clinically acceptable contralateral deficiency (<20%) for internal rotators compared to the non-surgical group. The peak torque ratio between the external and internal rotator muscles revealed a similar deficit of the external rotation in both groups and on both sides (surgical, 61.60% and 57.80% and non-surgical, 62.06% and 54.06%, for the dominant and non-dominant sides, respectively). The peak torque ratio revealed that the horizontal adduction muscles on the injured side showed similar weakness in both groups (surgical, 86.27%; non-surgical, 98.61%). CONCLUSIONS: This study included the largest single series of athletes reported to date for this type of injury. A comparative analysis of muscular strength and balance showed no differences between the treatment modalities for pectoralis major muscle rupture. However, the number of significant clinical deficiencies was lower in the surgical group than in the non-surgical group, and both treatment modalities require greater attention to the rehabilitation process, especially for the recovery of muscle strength and balance. PMID:21484052

  12. A Strength Model and Service Envelope for PBX 9501

    SciTech Connect

    Stevens, Ralph

    2014-02-05

    An analytical method is proposed for making an assessment of the severity of the response of PBX 9501 in structural response simulations. The approach is based on the coherent use of a strength model and a failure criterion. The strength model is based on a creep rupture function and an associated cumulative damage model. The material's residual strength at any time during a simulation of structural response is determined by taking into account both the actual stress history up to that time, and a hypothetical continuation of the applied stresses that are assumed to grow until material failure results. The residual strength is used by the failure criterion to define the region of safe (non-failed) material response. The Mohr-Coulomb failure criterion is chosen for its general applicability to materials with both cohesive and frictional strength. The combined use of the residual strength model and the failure criterion provides a quantitative method of assessing the severity of the response of PBX 9501 material in structural simulations: the proximity of any evolving, general state of stress to the failure surface (which shrinks due to the cumulative damage caused by the past stress history) can be calculated and used as a measure of margin to failure. The strength model has been calibrated to a broad range of uniaxial tension and compression tests, and a small set of creep tests, and is applicable to a broad range of loading conditions.

  13. Rupture process of a multiple main shock sequence: analysis of teleseismic, local and field observations of the Tennant Creek, Australia, earthquakes of January 22, 1988

    USGS Publications Warehouse

    Choy, G.L.; Bowman, J.R.

    1990-01-01

    On January 22, 1988, three large intraplate earthquakes (with MS 6.3, 6.4 and 6.7) occurred within a 12-hour period near Tennant Creek, Australia. Broadband displacement and velocity records of body waves from teleseismically recorded data are analyzed to determine source mechanisms, depths, and complexity of rupture of each of the three main shocks. Hypocenters of an additional 150 foreshocks and aftershocks constrained by local arrival time data and field observations of surface rupture are used to complement the source characteristics of the main shocks. The interpretation of the combined data sets suggests that the overall rupture process involved unusually complicated stress release. Rupture characteristics suggest that substantial slow slip occurred on each of the three fault interfaces that was not accompanied by major energy release. Variation of focal depth and the strong increase of moment and radiated energy with each main shock imply that lateral variations of strength were more important than vertical gradients of shear stress in controlling the progression of rupture. -from Authors

  14. Co-existence of a rare dyspnea with pericardial diaphragmatic rupture and pericardial rupture: a case report

    PubMed Central

    Karg?, Ahmet Bülent; Zeybek, Arife

    2015-01-01

    Pericardial-diaphragmatic rupture is a rare condition which occurs after blunt trauma and involves the herniation of abdominal organs into the pericardium. A 77-year-old female patient presenting with complaints of palpitation and difficulty in breathing was admitted to the emergency room. Left lateral thoracotomy revealed the herniation of abdominal organs into the thorax. A pericardial-diaphragmatic rupture and a pericardial rupture were found to co-exist. The diaphragm and the pericardium were repaired primarily. The case is presented here because herniation of abdominal organs into the pleural cavity through the pericardium is a rare condition. PMID:26336505

  15. Appendix T--Defining the Inversion Rupture Set Using Plausibility Filters

    E-print Network

    Shaw, Bruce E.

    the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3), California Reference Fault Parameter Earthquake Rupture Forecast, Version 3 (UCERF3) 2 Table T1. Summary of Uniform California Earthquake Rupture.S. Geological Survey. 3 University of Nevada, Reno. 4 Columbia University. #12;Appendix T of Uniform California

  16. Emergency endovascular repair of ruptured visceral artery aneurysms

    E-print Network

    Sadat, Umar; Noor, Nadim; Tang, Tjun Y; Varty, Kevin

    2007-07-02

    Abstract Background Visceral artery aneurysms although rare, have very high mortality if they rupture. Case presentation An interesting case of a bleeding inferior pancreaticduodenal artery aneurysm is reported in a young patient who presented...

  17. Neglected bilateral rupture of the patellar tendon: A case report.

    PubMed

    Cherrad, Taoufik; Louaste, Jamal; Kasmaoui, El Houcine; Bousbaä, Hicham; Rachid, Khaled

    2015-12-01

    Simultaneous bilateral rupture of the patellar tendon (PT) is extremely rare and is generally associated to some chronic diseases. When the rupture becomes chronic, it is more difficult to repair that as it remained untreated. The diagnosis, which is clinical, is often delayed, guided by standard radiography and confirmed by ultrasound or MRI. The management of a bilateral neglected, chronic patellar tendon rupture must address some serious difficulties: the proximally retracted patella, the reconstruction of the patellar tendon, finally, the temporary protection of this repair. We report a case of neglected bilateral rupture of the patellar tendon in a chronic hemodialysis patient, treated with a plastic surgery of the ipsilateral quadriceps tendon. PMID:26566349

  18. Rate dependent rupture of solid-supported phospholipid bilayers.

    E-print Network

    Ng, Sarah S

    2006-01-01

    An experimental study on solid-supported phospholipid bilayers was performed in order to investigate rate-dependent behavior of force and probability of bilayer rupture. 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine ...

  19. Aneurysmal Rupture of a Mesodiverticular Band to a Meckel's Diverticulum

    PubMed Central

    Sommerhalder, Christian; Fretwell, Kenneth R.; Salzler, Gregory G.; Creasy, John M.; Robitsek, R. Jonathan; Schubl, Sebastian D.

    2015-01-01

    Aneurysmal rupture of a mesodiverticular band has not previously been reported in the clinical literature. We are reporting a case of hemoperitoneum in a 51-year-old male after an aneurysmal rupture of a mesodiverticular band. This case demonstrates that in rare instances, a rupture of the mesodiverticular band leading to Meckel's diverticulum can lead to significant hemoperitoneum. This is usually caused by a traumatic injury but in our case was apparently caused by an aneurysm of the mesodiverticular artery. Patients with known Meckel's diverticula should be aware of the possibility of rupture, as should clinicians treating those with a history of this usually benign congenital abnormality. Rapid surgical intervention is necessary to repair the source of bleeding, as massive blood loss was encountered in this case. PMID:25688323

  20. Controls on earthquake rupture and triggering mechanisms in subduction zones

    E-print Network

    Llenos, Andrea Lesley

    2010-01-01

    Large earthquake rupture and triggering mechanisms that drive seismicity in subduction zones are investigated in this thesis using a combination of earthquake observations, statistical and physical modeling. A comparison ...

  1. Experimental investigation of creep rupture of reactor vessel lower head

    SciTech Connect

    Chu, Tze Yao; Pilch, M.M.; Bentz, J.H.

    1997-12-01

    This paper summarizes experiments on creep rupture of reactor pressure vessel (RPV) lower heads under the thermal and pressure loads of a core meltdown accident. Lower head failure (LHF) is of importance to accident assessment and accident management.

  2. Flutter analysis using transversality theory

    NASA Technical Reports Server (NTRS)

    Afolabi, D.

    1993-01-01

    A new method of calculating flutter boundaries of undamped aeronautical structures is presented. The method is an application of the weak transversality theorem used in catastrophe theory. In the first instance, the flutter problem is cast in matrix form using a frequency domain method, leading to an eigenvalue matrix. The characteristic polynomial resulting from this matrix usually has a smooth dependence on the system's parameters. As these parameters change with operating conditions, certain critical values are reached at which flutter sets in. Our approach is to use the transversality theorem in locating such flutter boundaries using this criterion: at a flutter boundary, the characteristic polynomial does not intersect the axis of the abscissa transversally. Formulas for computing the flutter boundaries and flutter frequencies of structures with two degrees of freedom are presented, and extension to multi-degree of freedom systems is indicated. The formulas have obvious applications in, for instance, problems of panel flutter at supersonic Mach numbers.

  3. Transverse wakefields at high dispersion

    SciTech Connect

    Decker, F.J.

    1992-03-01

    In high energy linear colliders the transverse beam emittance has to be preserved in order to achieve small interaction spots. If the beam is off-center in an accelerating cavity, it excites transverse wakefields, mainly the dipole mode, which deflects the tail of the beam leading to an emittance growth. In a high dispersive region, even a well centered beam can excite wakefields of higher order modes since the energy spread of the beam causes a transverse beam size which is comparable with the beam pipe. During the bunch length compression in the ring-to-linac (RTL) section of the Stanford Linear Collider (SLC), the beam pipe of 75 mm diameter is practically filled in the horizontal plane. Especially, if beam losses start to be involved, the very outer parts of the beam excite wakefields at any pipe irregularities like bellows, diameter steps, etc. Measured evidences, theoretical estimates and comparisons to other effects, like higher order magnet optics, are presented.

  4. Soft, Brown Rupture: Clinical Signs and Symptoms Associated with Ruptured PIP Breast Implants

    PubMed Central

    Duncan, Robert T.; Feig, Christine; Reintals, Michelle; Hill, Sarah

    2014-01-01

    Background: Preoperative signs and symptoms of patients with Poly Implant Prothese (PIP) implants could be predictive of device failure. Based on clinical observation and intraoperative findings 4 hypotheses were raised: (1) Preoperative clinical signs including acquired asymmetry, breast enlargement, fullness of the lower pole, decreased mound projection, and change in breast consistency could be indicative of implant rupture. (2) Device failure correlates with a low preoperative Baker grade of capsule. (3) Brown-stained implants are more prone to implant failure. (4) The brown gel could be indicative of iodine ingression through a substandard elastomer shell. Methods: Preoperative clinical signs were compared with intraoperative findings for 27 patients undergoing PIP implant explantation. Results: Acquired asymmetry (P = 0.0003), breast enlargement (P = 0.0002), fuller lower pole (P < 0.0001), and loss of lateral projection (P < 0.0001) were all significantly predictive of device failure. Capsule Baker grade was lower preoperatively for ruptured implants. The lack of palpable and visible preoperative capsular contracture could be secondary to the elastic nature of the capsular tissue found. Brown implants failed significantly more often than white implants. Analysis of brown gel revealed the presence of iodine, suggesting povidone iodine ingression at implantation. Conclusions: Preoperative signs can be predictive of PIP implant failure. Brown-stained implants are more prone to rupture. The presence of iodine in the gel suggests unacceptable permeability of the shell early in the implant’s life span. A noninvasive screening test to detect brown implants in situ could help identify implants at risk of failure in those who elect to keep their implants. PMID:25506532

  5. Rapid Estimates of Rupture Extent for Large Earthquakes Using Aftershocks

    NASA Astrophysics Data System (ADS)

    Polet, J.; Thio, H. K.; Kremer, M.

    2009-12-01

    The spatial distribution of aftershocks is closely linked to the rupture extent of the mainshock that preceded them and a rapid analysis of aftershock patterns therefore has potential for use in near real-time estimates of earthquake impact. The correlation between aftershocks and slip distribution has frequently been used to estimate the fault dimensions of large historic earthquakes for which no, or insufficient, waveform data is available. With the advent of earthquake inversions that use seismic waveforms and geodetic data to constrain the slip distribution, the study of aftershocks has recently been largely focused on enhancing our understanding of the underlying mechanisms in a broader earthquake mechanics/dynamics framework. However, in a near real-time earthquake monitoring environment, in which aftershocks of large earthquakes are routinely detected and located, these data may also be effective in determining a fast estimate of the mainshock rupture area, which would aid in the rapid assessment of the impact of the earthquake. We have analyzed a considerable number of large recent earthquakes and their aftershock sequences and have developed an effective algorithm that determines the rupture extent of a mainshock from its aftershock distribution, in a fully automatic manner. The algorithm automatically removes outliers by spatial binning, and subsequently determines the best fitting “strike” of the rupture and its length by projecting the aftershock epicenters onto a set of lines that cross the mainshock epicenter with incremental azimuths. For strike-slip or large dip-slip events, for which the surface projection of the rupture is recti-linear, the calculated strike correlates well with the strike of the fault and the corresponding length, determined from the distribution of aftershocks projected onto the line, agrees well with the rupture length. In the case of a smaller dip-slip rupture with an aspect ratio closer to 1, the procedure gives a measure of the rupture extent and dimensions, but not necessarily the strike. We found that using standard earthquake catalogs, such as the National Earthquake Information Center catalog, we can constrain the rupture extent, rupture direction, and in many cases the type of faulting, of the mainshock with the aftershocks that occur within the first hour after the mainshock. However, this data may not be currently available in near real-time. Since our results show that these early aftershock locations may be used to estimate first order rupture parameters for large global earthquakes, the near real-time availability of these data would be useful for fast earthquake damage assessment.

  6. Determination of closure disk rupture parameters

    SciTech Connect

    Merten, C.W.; Robinson, M.A. ); Evans, N.A. )

    1990-01-01

    The necessity of decoupling strain rate from burn rate effects for tests designed to characterize closure disks is discussed. A method for simulating the high rates of pressure increase to which closure disks are subjected and which does not employ pyrotechnic material as a means of pressurization is presented. It consists of slowly pressurizing both sides of a closure disk to a high pressure and then rapidly releasing the pressure from one side of the disk. Means of rapidly releasing gas from the downstream side of the closure disk and measuring the pressure differential across the closure disk are discussed in detail. Rates of pressure decrease as high as 335,000,000 psi/sec downstream from the closure disk have been attained. Baseline disks slotted by wire EDM failed at an average pressure differential of 10,150 psi. Disks slotted by chemical etching exhibited a higher burst pressure differential and greater variability. Glass-ceramic closure disks had the lowest average burst pressure and highest variability. An increase in the diameter of a closure disk was found to lower the pressure differential required to rupture the disk. Burst pressure was found to increase linearly with the thickness of the web in the slot. 5 refs., 6 figs., 5 tabs.

  7. Measurement of laser-ion guiding channel strength

    SciTech Connect

    Lauer, E.J.; Caporaso, G.J.; Chong, Y.P.; Prono, D.S.; Rainer, F.; Struve, K.W.; Weir, J.T.

    1986-01-01

    The Advanced Test Accelerator (ATA) beam is guided in a low density ion channel produced in benzene gas by a KrF laser. The strength of the ion channel has been measured by deflecting the electron beam in a steady transverse magnetic field. After emerging from the magnetic field, the beam oscillates transversely inside the channel with a few mm amplitude. The transverse position of the beam is measured at many positions using the wall current monitors. The wavelength of the oscillation is measured from a plot of transverse position vs propagation distance. With a 0.5 J laser pulse and 4 x 10/sup -4/ Torr benzene pressure the wavelength was 1 m corresponding to 90 esu/cm/sup 3/ with ..gamma.. = 84.

  8. Relationship between high-frequency radiation and asperity ruptures, revealed by hybrid back-projection with a non-planar fault model.

    PubMed

    Okuwaki, Ryo; Yagi, Yuji; Hirano, Shiro

    2014-01-01

    High-frequency seismic waves are generated by abrupt changes of rupture velocity and slip-rate during an earthquake. Therefore, analysis of high-frequency waves is crucial to understanding the dynamic rupture process. Here, we developed a hybrid back-projection method that considers variations in focal mechanisms by introducing a non-planar fault model that reflects the subducting slab geometry. We applied it to teleseismic P-waveforms of the Mw 8.8 2010 Chile earthquake to estimate the spatiotemporal distribution of high-frequency (0.5-2.0 Hz) radiation. By comparing the result with the coseismic slip distribution obtained by waveform inversion, we found that strong high-frequency radiation can precede and may trigger a large asperity rupture. Moreover, in between the large slip events, high-frequency radiation of intermediate strength was concentrated along the rupture front. This distribution suggests that by bridging the two large slips, this intermediate-strength high-frequency radiation might play a key role in the interaction of the large slip events. PMID:25406638

  9. Relationship between High-frequency Radiation and Asperity Ruptures, Revealed by Hybrid Back-projection with a Non-planar Fault Model

    PubMed Central

    Okuwaki, Ryo; Yagi, Yuji; Hirano, Shiro

    2014-01-01

    High-frequency seismic waves are generated by abrupt changes of rupture velocity and slip-rate during an earthquake. Therefore, analysis of high-frequency waves is crucial to understanding the dynamic rupture process. Here, we developed a hybrid back-projection method that considers variations in focal mechanisms by introducing a non-planar fault model that reflects the subducting slab geometry. We applied it to teleseismic P-waveforms of the Mw 8.8 2010 Chile earthquake to estimate the spatiotemporal distribution of high-frequency (0.5–2.0?Hz) radiation. By comparing the result with the coseismic slip distribution obtained by waveform inversion, we found that strong high-frequency radiation can precede and may trigger a large asperity rupture. Moreover, in between the large slip events, high-frequency radiation of intermediate strength was concentrated along the rupture front. This distribution suggests that by bridging the two large slips, this intermediate-strength high-frequency radiation might play a key role in the interaction of the large slip events. PMID:25406638

  10. [Spontaneous hepatic rupture during an uncomplicated twin pregnancy].

    PubMed

    Fat, B Chung; Terzibachian, J J; Grisey, A; Houzé, J P; Faller, J P; Leung, F; de Lapparent, T; Maillet, R; Riethmuller, D

    2011-01-01

    Liver subcapsular haematoma and its consequence, spontaneous hepatic rupture, are very rare complications of pregnancy. They are mainly associated with pre-eclampsia. The diagnosis is difficult and the maternal and fetal mortality rates are high. We report the case of a spontaneous hepatic rupture on a normal liver during an uncomplicated twin pregnancy with a favorable outcome for both the mother and the newborns. PMID:21183383

  11. Complex rupture source of the 12 January 2010 Léogâne, Haiti earthquake derived from geologic, geodetic, and seismologic observations

    NASA Astrophysics Data System (ADS)

    Briggs, R. W.; Hayes, G. P.; Sladen, A.; Fielding, E. J.; Prentice, C. S.; Hudnut, K. W.; Mann, P.; Taylor, F. W.; Crone, A. J.; Gold, R. D.; Ito, T.; Simons, M.; Jean, P.

    2010-12-01

    The Mw 7.0, 12 January 2010 Léogâne, Haiti earthquake initially appeared to be a straightforward accommodation of oblique relative motion between the Caribbean and North America plates along the previously recognized Enriquillo-Plantain Garden fault zone (EPGF). Our combined geologic field observations, space geodetic measurements, and seismologic data show that the rupture process of this event involved slip on multiple faults and that slip along the EPGF was minimal or absent. Instead, primary surface deformation resulted from rupture on previously unrecognized blind thrust faults with only minor, deep lateral slip along or near the main EPGF. We quantified uplift along the coast north of the EPGF using vertically displaced coral microatolls. SAR interferograms demonstrate that the observed coastal deformation reflects a broader pattern of uplift and subsidence. Seismologic observations (including body-wave first motions, high non-double couple components of moment tensor inversions, the aftershock distribution and their associated moment tensors) imply that the rupture involved multiple faults. A joint inversion of all data sets yields a preferred model of slip on three faults to explain the principal observations. Moment-release calculations show that this event only partially relieved centuries of accumulated left-lateral strain on a small part of the plate-boundary system. The lack of surface deformation along the EPGF--which shows clear field evidence for Holocene, and probably historic surface rupture--and the predominance of shallow off-fault thrusting implies that considerable shallow shear strain remains to be released in future surface-rupturing earthquakes on the EPGF, including the section adjacent to Port-au-Prince. Because the geologic signature of this earthquake involves broad warping and coastal deformation rather than surface rupture along the main fault zone, the event will not leave a distinct geologic signal that will be easily recognized by standard paleoseismic studies. This suggests that prehistoric earthquake records in transpressive tectonic environments, such as the San Andreas fault through the Transverse Ranges of California, may be missing similarly complex earthquakes.

  12. Incidence and outcome of rupture of the Achilles tendon.

    PubMed

    Cretnik, Andrej; Frank, Aleksander

    2004-01-01

    We determined the incidence of complete rupture of the Achilles tendon in the Maribor region (273,609 inhabitants) between 1991 and 1996. During this period, 116 ruptures were treated at Maribor Teaching Hospital. The average incidence was 7 ruptures per 100,000 inhabitants, with a peak incidence of almost 9 per 100,000. Most injuries (65%) occurred during sports activities, with soccer as the major cause of rupture. The average age of patients was 37 years with a male-to-female ratio of 18:1. All patients underwent open surgical repair of the ruptured Achilles tendon, with a minimum follow-up of two years. 19.8% of cases developed complications and in 10.4% of these the complications were major. 1.9% of patients sustained a re-rupture. The mean AOFAS score was 96 points. The patients were subjectively very satisfied with their treatment in 88% of cases. Good functional results with a return to the usual pre-injury activities were achieved in 96% of patients. PMID:15506308

  13. The temporal distribution of seismic radiation during deep earthquake rupture

    USGS Publications Warehouse

    Houston, H.; Vidale, J.E.

    1994-01-01

    The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period seismic radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is released toward the beginning of the rupture than near the end, whereas for deep events radiation is released symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.The time history of energy release during earthquakes illuminates the process of failure, which remains enigmatic for events deeper than about 100 kilometers. Stacks of teleseismic records from regional arrays for 122 intermediate (depths of 100 to 350 kilometers) and deep (depths of 350 to 700 kilometers) earthquakes show that the temporal pattern of short-period seismic radiation has a systematic variation with depth. On average, for intermediate depth events more radiation is released toward the beginning of the rupture than near the end, whereas for deep events radiation is released symmetrically over the duration of the event, with an abrupt beginning and end of rupture. These findings suggest a variation in the style of rupture related to decreasing fault heterogeneity with depth.

  14. Rupture of a Biomembrane under Dynamic Surface Tension

    E-print Network

    D. J. Bicout; E. I. Kats

    2011-12-19

    How long a fluid membrane vesicle stressed with a steady ramp of micropipette last before rupture? Or conversely, how high the surface tension should be to rupture a membrane? To answer these challenging questions we have developed a theoretical framework that allows description and reproduction of Dynamic Tension Spectroscopy (DTS) observations. The kinetics of the membrane rupture under ramps of surface tension is described as a combination of initial pore formation followed by Brownian process of the pore radius crossing the time-dependent energy barrier. We present the formalism and derive (formal) analytical expression of the survival probability describing the fate of the membrane under DTS conditions. Using numerical simulations for the membrane prepared in an initial state with a given distribution of times for pore nucleation, we have studied the membrane lifetime (or inverse of rupture rate) and distribution of membrane surface tension at rupture as a function of membrane characteristics like pore nucleation rate, the energy barrier to failure and tension loading rate. It is found that simulations reproduce main features of the experimental data, particularly, the pore nucleation and pore size diffusion controlled limits of membrane rupture dynamics. This approach can also be applied to processes of permeation and pore opening in membranes (electroporation, membrane disruption by antimicrobial peptides, vesicle fusion).

  15. Volume Fraction Dependence of Droplet Rupturing in Concentrated Nanoemulsions

    NASA Astrophysics Data System (ADS)

    Meleson, K.

    2005-03-01

    We investigate droplet rupturing by extreme shear in concentrated silicone oil-in-water nanoemulsions stabilized by sodium dodecyl sulfate (SDS) surfactant. According to Taylor's prediction for dilute emulsions, the ruptured droplet radius, a, varies inversely with the viscosity of the continuous phase. If one assumes that the emulsion's effective viscosity controls the average radius of the ruptured droplets, then emulsions that have larger droplet volume fractions, ?s would be ruptured by the same shear flow to smaller radii. In stark contrast to this, we find that the average droplet radius actually rises with as ? approaches the quiescent maximally random jammed value of 0.64. This is evidence that both droplet rupturing and coalescence occur when concentrated emulsions are subjected to extreme shear. We have also observed phase inversion to an oil-continuous emulsion for ? > 0.64. This supports the idea that coalescence occurs as the driving shear breaks thin films between the concentrated oil droplets at high ?. In addition, we find that the ruptured droplet size is relatively insensitive to large changes in the oil viscosity inside the droplets.

  16. Composite impact strength improvement through a fiber/matrix interphase

    NASA Technical Reports Server (NTRS)

    Cavano, P. J.; Winters, W. E.

    1975-01-01

    Research was conducted to improve the impact strength and toughness of fiber/resin composites by means of a fiber coating interphase. Graphite fiber/epoxy resin composites were fabricated with four different fiber coating systems introduced in a matrix-fiber interphase. Two graphite fibers, a high strength and a high modulus type, were studied with the following coating systems: chemical vapor deposited boron, electroless nickel, a polyamide-imide resin and a thermoplastic polysulfone resin. Evaluation methods included the following tests: Izod, flexure, shear fracture toughness, longitudinal and transverse tensile, and transverse and longitudinal compression. No desirable changes could be effected with the high strength fiber, but significant improvements in impact performance were observed with the polyamide-imide resin coated high modulus fiber with no loss in composite modulus.

  17. Strengths of Remarried Families.

    ERIC Educational Resources Information Center

    Knaub, Patricia Kain; And Others

    1984-01-01

    Focuses on remarried families' (N=80) perceptions of family strengths, marital satisfaction, and adjustment to the remarried situation. Results indicated that although most would like to make some changes, scores on the measurements used were high. A supportive environment was the most important predictor of family strength and success. (JAC)

  18. The effect of fiber reinforcement type and water storage on strength properties of a provisional fixed partial denture resin.

    PubMed

    Uzun, Gülay; Keyf, Filiz

    2003-04-01

    Fracture resistance of provisional restorations is an important clinical concern. This property is directly related to transverse strength. Strengthening of provisional fixed partial dentures may result from reinforcement with various fiber types. This study evaluated the effect of fiber type and water storage on the transverse strength of a commercially available provisional resin under two different conditions. The denture resin was reinforced with either glass or aramid fiber or no reinforcement was used. Uniform samples were made from a commercially available autopolymerizing provisional fixed partial denture resin. Sixteen bar-shaped specimens (60 x 10 x 4 mm) were reinforced with pre-treated epoxy resin-coated glass fibers, with aramid fibers, or with no fibers. Eight specimens of each group, with and without fibers, were tested after 24 h of fabrication (immediate group), and after 30-day water storage. A three-point loading test was used to measure the transverse strength, the maximal deflection, and the modulus of elasticity. The Kruskal-Wallis Analysis of Variance was used to examine differences among the three groups, and then the Mann-Whitney U Test and Wilcoxon Signed Ranks Test were applied to determine pair-wise differences. The transverse strength and the maximal deflection values in the immediate group and in the 30-day water storage group were not statistically significant. In the group tested immediately, the elasticity modulus was found to be significant (P = 0.042). In the 30-day water storage group, all the values were statistically insignificant. The highest transverse strength was displayed by the glass-reinforced resin (66.25MPa) in the immediate group. The transverse strength value was 62.04MPa for the unreinforced samples in the immediate group. All the specimens exhibited lower transverse strength with an increase in water immersion time. The transverse strength value was 61.13 MPa for the glass-reinforced resin and was 61.24 MPa for the unreinforced resin. The aramid-reinforced resin decreased from 62.29 to 58.77 MPa. The addition of fiber reinforcement enhanced the physical properties (the transverse strength, the maximal deflection, the modulus of elasticity) of the processed material over that seen with no addition of fiber. Water storage did not statistically affect the transverse strength of the provisional denture resin compared to that of the unreinforced resin. The transverse strength was lowered at water storage but it was not statistically significant. The transverse strength was enhanced by fiber addition compared to the unreinforced resin. The glass fiber was superior to the other fiber. Also the modulus of elasticity was enhanced by fiber addition compared to the unreinforced resin. PMID:12797420

  19. Anisotropy of high temperature strength in precipitation-hardened nickel-base superalloy single crystals

    NASA Technical Reports Server (NTRS)

    Nakagawa, Y. G.; Terashima, H.; Yoshizawa, H.; Ohta, Y.; Murakami, K.

    1986-01-01

    The anisotropy of high temperature strength of nickel-base superalloy, Alloy 454, in service for advanced jet engine turbine blades and vanes, was investigated. Crystallographic orientation dependence of tensile yield strength, creep and creep rupture strength was found to be marked at about 760C. In comparison with other single crystal data, a larger allowance in high strength off-axial orientation from the 001 axis, and relatively poor strength at near the -111 axis were noted. From transmission electron microscopy the anisotropic characteristics of this alloy were explained in terms of available slip systems and stacking geometries of gamma-prime precipitate cuboids which are well hardened by a large tantalum content. 100 cube slip was considered to be primarily responsible for the poor strength of the -111 axis orientation replacing the conventional 111 plane slip systems.

  20. [Effect of fillers on the strength of silicone systems].

    PubMed

    Snejdrová, E; Zelenka, J; Rehula, M

    2002-07-01

    The present paper examines the strength behaviour of addition silicone systems composed of Lukopren A 6200 and three inorganic fillers (Skron SF 600, Cab-O-Sil LM 150, sodium chloride) in different concentrations and particle sizes. The tensile strength sigma (MPa) and the relative lengthening of samples on rupture epsilon (%) were measured. With increasing concentration of the filler in the system relative lengthening of matrices is decreased. This trend corresponds with the theoretical hypotheses and it is understandable also with regard to the fact that the filler, in comparison with silicone rubber, possesses very low ductility. An addition of Sikron increases tensile strength of samples. Dependence of tensile strength on the amount of Sikron in the system is linear. This behaviour is typical of fibrous composites and the composites with high adhesion between the filler and matrix. Concentrations of Cab-O-Sil up to 5% did not exert an effect on tensile strength. An important increase in strength was shown only by the systems containing 10% of Cab-O-Sil. Experimental dependence of tensile strength on the amount of Cab-O-Sil in the system can be described by the equation for composites with Hookean behaviour till destruction. The effect of sodium chloride on tensile strength is more complicated. In the systems with NaCl particles of 20 microns, strength is not practically changed up to a content of 40% of NaCl in the system. In larger size fractions, tensile strength is decreased, and with a change in particle size, shape is probably changed as well. PMID:12183909

  1. An oxide dispersion strengthened Ni-W-Al alloy with superior high temperature strength

    NASA Technical Reports Server (NTRS)

    Glasgow, T. K.

    1976-01-01

    An experimental oxide dispersion strengthened (ODS) alloy, WAZ-D, derived from the WAZ-20 composition was produced by the mechanical alloying process. Cast WAZ-20 is strengthened by both a high refractory metal content, and 70 volume percent of gamma prime. The ODS alloy WAZ-D was responsive to variables of alloy content, of attritor processing, of consolidation by extrusion, and of heat treatment. The best material produced had large highly elongated grains. It exhibited tensile strengths generally superior to a comparable cast alloy. The ODS alloy exhibited high temperature stress rupture life considerably superior to any known cast superalloy. Tensile and rupture ductility were low, as was intermediate temperature rupture life. Very low creep rates were noted and some specimens failed with essentially no third stage creep. Also the benefit derived from the oxide dispersion, far out-weighed that from the elongated microstructure alone.

  2. Transverse Energy Production at RHIC

    E-print Network

    Qun Li; Yang Pang; Nu Xu

    1999-06-18

    We study the mechanism of transverse energy (E_T) production in Au+Au collisions at RHIC. The time evolution starting from the initial energy loss to the final E_T production is closely examined in transport models. The relationship between the experimentally measured E_T distribution and the maximum energy density achieved is discussed.

  3. Transverse Magnetic Field Propellant Isolator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2000-01-01

    An alternative high voltage isolator for electric propulsion and ground-based ion source applications has been designed and tested. This design employs a transverse magnetic field that increases the breakdown voltage. The design can greatly enhance the operating range of laboratory isolators used for high voltage applications.

  4. Determination of Early Age Mortar and Concrete Strength by Ultrasonic Wave Reflections

    E-print Network

    1 , Yilmaz Akkaya2 , Surendra P. Shah3 Keywords: nondestructive tests, ultrasonic tests, compressiveDetermination of Early Age Mortar and Concrete Strength by Ultrasonic Wave Reflections Thomas Voigt strength, concrete, mortars, hydration, wave reflection, transverse waves ABSTRACT The in-situ testing

  5. Fiber-Level Modeling of Dynamic Strength KM2 Ballistic Fabric

    E-print Network

    Grujicic, Mica

    Fiber-Level Modeling of Dynamic Strength of KevlarÒ KM2 Ballistic Fabric M. Grujicic, A. Hariharan between the fabric penetration resistance and various fiber-level phenomena such as fiber-fiber friction, fiber twist, transverse properties of the fibers, and the stochastic nature of fiber strength

  6. Alumina strength degradation in the elastic regime

    SciTech Connect

    Furnish, M.D.; Chhabildas, L.C.

    1997-08-01

    Measurements of Kanel et. al. [1991] have suggested that deviatoric stresses in glasses shocked to nearly the Hugoniot Elastic limit (HEL) relax over a time span of microseconds after initial loading. Failure (damage) waves have been inferred on the basis of these measurements using time-resolved manganin normal and transverse stress gauges. Additional experiments on glass by other researchers, using time-resolved gauges, high-speed photography and spall strength determinations have also lead to the same conclusions. In the present study the authors have conducted transmitted-wave experiments on high-quality Coors AD995 alumina shocked to roughly 5 and 7 GPa (just below or at the HEL). The material is subsequently reshocked to just above its elastic limit. Results of these experiments do show some evidence of strength degradation in the elastic regime.

  7. Single Molecule Junctions: A Laboratory for Chemistry, Mechanics and Bond Rupture

    SciTech Connect

    Hybertsen M. S.

    2013-07-08

    Simultaneous measurement [1] of junction conductance and sustained force in single molecule junctions bridging metal electrodes provides a powerful tool in the quantitative study of the character of molecule-metal bonds. In this talk I will discuss three topics. First, I will describe chemical trends in link bond strength based on experiments and Density Functional Theory based calculations. Second, I will focus on the specific case of pyridine-linked junctions. Bond rupture from the high conductance junction structure shows a requires a force that exceeds the rupture force of gold point contacts and clearly indicates the role of additional forces, beyond the specific N-Au donor acceptor bond. DFT-D2 calculations with empirical addition of dispersion interactions illustrates the interplay between the donor-acceptor bonding and the non-specific van der Waals interactions between the pyridine rings and Au asperities. Third, I will describe recent efforts to characterize the diversity of junction structures realized in break-junction experiments with suitable models for the potential surfaces that are observed. [1] Venkataraman Group, Columbia University.

  8. In-vitro reconstruction of massive rotator cuff ruptures with triceps tendon or coracoacromial ligament.

    PubMed

    Schlepckow, P; Sigg, A

    2001-05-01

    The possibility of reconstructing a massive rotator cuff rupture with a free graft of the triceps tendon or the coracoacromial ligament was tested experimentally in an anatomical and biophysical cadaver investigation. After dissection of the rotator cuff, a section of the supraspinatus tendon was removed to simulate a defect in the cuff. In dissection of the grafts, a bony squama was incorporated by osteotomy. The rotator cuff was reconstructed by suturing the free grafts into the defect. In addition, the bony squama was refixed in a prepared bone groove in the greater tuberosity of the humerus. The tensile strength and the elasticity of the grafts were compared with that of the supraspinatus tendon in rupture tests. The mean value of the maximum load determined (FRm) was greatest for the triceps tendon (706.451 N), while very much lower values were found for the coracoacromial ligament (395.836 N) and the supraspinatus tendon (496.792 N). The mean value of the maximum elasticity (LAm) was lowest for the coracoacromial ligament (4.701%); the supraspinatus tendon (7.047%) and the triceps tendon (8.250%) showed very much greater elasticity. PMID:11409561

  9. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    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 the current hypothesized biological triggers of pathological remodeling of the artery walls. Having a good natural ratio of statuses in our IA cohort (55 unruptured vs. 19 ruptured), we were able to test the statistical significance of our predictor to fortify our findings. We also performed a distribution analysis of our cohort with respect to the number of WKV to strengthen the encouraging statistical analysis result; both analyses provided a clear good separation of the status of the aneurysms based on our predictor. Lastly, we constructed a receiver operating characteristic (ROC) curve to analyze the power different thresholds of WKV had in splitting the data in a binary way (unruptured/ruptured). The number of WKV was efficaciously able to stratify the rupture status, identifying 84.21 % of the ruptured aneurysms (with 25.45 % of false positives, i.e. unruptured IAs tagged as ruptured) when using a threshold value of 2. Our novel work undertaken to study the vortex structures in IAs brought to light interesting characteristics of the flow in the aneurysmal sac. We found that there are several distinct categories in which the aneurysm vortex topologies can be put in without relationship to the aneurysm rupture status. This first finding was in contradiction with available already-published results. Nonetheless, ruptured IAs had a statistically significant larger amount of WKV as opposed to unruptured aneurysms. This new predictor we propose to the community could very well clear a new path among the currently controversial WSS-based parameters. Although it needs to be improved to be more resilient, the first results obtained by the WKV-based parameter are promising when applied to a large dataset of 74 IAs patient-specific transient CFD simulations.

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifing Philosophy

    NASA Technical Reports Server (NTRS)

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, Leigh

    2007-01-01

    The NASA Engineering and Safety Center (NESC) has been conducting an independent technical assessment to address safety concerns related to the known stress rupture failure mode of filament wound pressure vessels in use on Shuttle and the International Space Station. The Shuttle's Kevlar-49 fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar-49 filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of load sharing liners and the complex manufacturing procedures, the state of actual fiber stress in flight hardware and test articles is not clearly known. Indeed non-conservative life predictions have been made where stress rupture data and lifing procedures have ignored the contribution of the liner in favor of applied pressure as the controlling load parameter. With the aid of analytical and finite element results, this paper examines the fundamental mechanical response of composite overwrapped pressure vessels including the influence of elastic-plastic liners and degraded/creeping overwrap properties. Graphical methods are presented describing the non-linear relationship of applied pressure to Kevlar-49 fiber stress/strain during manufacturing, operations and burst loadings. These are applied to experimental measurements made on a variety of vessel systems to demonstrate the correct calibration of fiber stress as a function of pressure. Applying this analysis to the actual qualification burst data for Shuttle flight hardware revealed that the nominal fiber stress at burst was in some cases 23% lower than what had previously been used to predict stress rupture life. These results motivate a detailed discussion of the appropriate stress rupture lifing philosophy for COPVs including the correct transference of stress rupture life data between dissimilar vessels and test articles.

  12. Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifting Philosophy

    NASA Technical Reports Server (NTRS)

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, S. L.

    2009-01-01

    The NASA Engineering and Safety Center (NESC) has been conducting an independent technical assessment to address safety concerns related to the known stress rupture failure mode of filament wound pressure vessels in use on Shuttle and the International Space Station. The Shuttle s Kevlar-49 (DuPont) fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar-49 filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of load sharing liners and the complex manufacturing procedures, the state of actual fiber stress in flight hardware and test articles is not clearly known. Indeed nonconservative life predictions have been made where stress rupture data and lifing procedures have ignored the contribution of the liner in favor of applied pressure as the controlling load parameter. With the aid of analytical and finite element results, this paper examines the fundamental mechanical response of composite overwrapped pressure vessels including the influence of elastic plastic liners and degraded/creeping overwrap properties. Graphical methods are presented describing the non-linear relationship of applied pressure to Kevlar-49 fiber stress/strain during manufacturing, operations and burst loadings. These are applied to experimental measurements made on a variety of vessel systems to demonstrate the correct calibration of fiber stress as a function of pressure. Applying this analysis to the actual qualification burst data for Shuttle flight hardware revealed that the nominal fiber stress at burst was in some cases 23 percent lower than what had previously been used to predict stress rupture life. These results motivate a detailed discussion of the appropriate stress rupture lifing philosophy for COPVs including the correct transference of stress rupture life data between dissimilar vessels and test articles.

  13. Increased 18F-FDG Uptake Is Predictive of Rupture in a Novel Rat Abdominal Aortic Aneurysm Rupture Model

    PubMed Central

    English, Sean J.; Piert, Morand R.; Diaz, Jose A.; Gordon, David; Ghosh, Abhijit; D'Alecy, Louis G.; Whitesall, Steven E.; Sharma, Ashish K.; DeRoo, Elise P.; Watt, Tessa; Su, Gang; Henke, Peter K.; Eliason, Jonathan L.; Ailawadi, Gorav; Upchurch, Gilbert R.

    2015-01-01

    Objective To determine whether 18F-fluorodeoxyglucose (18F-FDG) micro–positron emission tomography (micro-PET) can predict abdominal aortic aneurysm (AAA) rupture. Background An infrarenal AAA model is needed to study inflammatory mechanisms that drive rupture. 18F-FDG PET can detect vascular inflammation in animal models and patients. Methods After exposing Sprague-Dawley rats to intra-aortic porcine pancreatic elastase (PPE) (12 U/mL), AAA rupture was induced by daily, subcutaneous, ?-aminopropionitrile (BAPN, 300 mg/kg, N = 24) administration. Negative control AAA animals (N = 15) underwent daily saline subcutaneous injection after PPE exposure. BAPN-exposed animals that did not rupture served as positive controls [nonruptured AAA (NRAAA) 14d, N = 9]. Rupture was witnessed using radiotelemetry. Maximum standard uptakes for 18F-FDG micro-PET studies were determined. Aortic wall PAI-1, uPA, and tPA concentrations were determined by western blot analyses. Interleukin (IL)-1?, IL-6, IL-10, and MIP-2 were determined by Bio-Plex bead array. Neutrophil and macrophage populations per high-power field were quantified. Matrix metalloproteinase (MMP) activities were determined by zymography. Results When comparing ruptured AAA (RAAA) to NRAAA 14d animals, increased focal 18F-FDG uptakes were detected at subsequent sites of rupture (P = 0.03). PAI-1 expression was significantly less in RAAA tissue (P = 0.01), with comparable uPA and decreased tPA levels (P = 0.02). IL-1? (P = 0.04), IL-6 (P = 0.001), IL-10 (P = 0.04), and MIP-2 (P = 0.02)expression, neutrophil (P = 0.02) and macrophage presence (P = 0.002), and MMP9 (P < 0.0001) activity were increased in RAAA tissue. Conclusions With this AAA rupture model, increased prerupture 18F-FDG uptake on micro-PET imaging was associated with increased inflammation in the ruptured AAA wall. 18F-FDG PET imaging may be used to monitor inflammatory changes before AAA rupture. PMID:24651130

  14. Distribution of stress drop, stiffness, and fracture energy over earthquake rupture zones

    USGS Publications Warehouse

    Fletcher, Joe B.; McGarr, A.

    2006-01-01

    Using information provided by slip models and the methodology of McGarr and Fletcher (2002), we map static stress drop, stiffness (k = ????/u, where ???? is static stress drop and u is slip), and fracture energy over the slip surface to investigate the earthquake rupture process and energy budget. For the 1994 M6.7 Northridge, 1992 M7.3 Landers, and 1995 M6.9 Kobe earthquakes, the distributions of static stress drop show strong heterogeneity, emphasizing the importance of asperities in the rupture process. Average values of static stress drop are 17, 11, and 4 Mpa for Northridge, Landers, and Kobe, respectively. These values are substantially higher than estimates based on simple crack models, suggesting that the failure process involves the rupture of asperities within the larger fault zone. Stress drop as a function of depth for the Northridge and Landers earthquakes suggests that stress drops are limited by crustal strength. For these two earthquakes, regions of high slip are surrounded by high values of stiffness. Particularly for the Northridge earthquake, the prominent patch of high slip in the central part of the fault is bordered by a ring of high stiffness and is consistent with expectations based on the failure of an asperity loaded at its edge due to exterior slip. Stiffness within an asperity is inversely related to its dimensions. Estimates of fracture energy, based on static stress drop, slip, and rupture speed, were used to investigate the nature of slip weakening at four locations near the hypocenter of the Kobe earthquake for comparison with independent results based on a dynamic model of this earthquake. One subfault updip and to the NE of the hypocenter has a fracture energy of 1.1 MJ/m2 and a slip-weakening distance, Dc, of 0.66 m. Right triangles, whose base and height are Dc and the dynamic stress drop, respectively, approximately overlie the slip-dependent stress given by Ide and Takeo (1997) for the same locations near the hypocenter. The total fracture energy for the Kobe earthquake, 3.7 ?? 1014 J, is about the same as the seismic energy (Ea = 3.2 ?? 1014 J.

  15. Evidence for and implications of self-healing pulses of slip in earthquake rupture

    USGS Publications Warehouse

    Heaton, T.H.

    1990-01-01

    Dislocation time histories of models derived from waveforms of seven earthquakes are discussed. In each model, dislocation rise times (the duration of slip for a given point on the fault) are found to be short compared to the overall duration of the earthquake (??? 10%). However, in many crack-like numerical models of dynamic rupture, the slip duration at a given point is comparable to the overall duration of the rupture; i.e. slip at a given point continues until information is received that the rupture has stopped propagating. Alternative explanations for the discrepancy between the short slip durations used to model waveforms and the long slip durations inferred from dynamic crack models are: (1) the dislocation models are unable to resolve the relatively slow parts of earthquake slip and have seriously underestimated the dislocations for these earthquakes; (2) earthquakes are composed of a sequence of small-dimension (short duration) events that are separated by locked regions (barriers); (3) rupture occurs in a narrow self-healing pulse of slip that travels along the fault surface. Evidence is discussed that suggests that slip durations are indeed short and that the self-healing slip-pulse model is the most appropriate explanation. A qualitative model is presented that produces self-healing slip pulses. The key feature of the model is the assumption that friction on the fault surface is inversely related to the local slip velocity. The model has the following features: high static strength of materials (kilobar range), low static stress drops (in the range of tens of bars), and relatively low frictional stress during slip (less than several hundreds of bars). It is suggested that the reason that the average dislocation scales with fault length is because large-amplitude slip pulses are difficult to stop and hence tend to propagate large distances. This model may explain why seismicity and ambient stress are low along fault segments that have experienced large earthquakes. It also qualitatively explains why the recurrence time for large earthquakes may be irregular. ?? 1990.

  16. The Mw 6.5 offshore Northern California earthquake of 10 January 2010: Ordinary stress drop on a high-strength fault

    NASA Astrophysics Data System (ADS)

    Wei, Meng; McGuire, Jeffrey J.

    2014-09-01

    The 10 January 2010 Mw 6.5 earthquake offshore Northern California is one of the first intraplate earthquakes in oceanic lithosphere to be well captured by a GPS network. It presents an opportunity to evaluate rupture mechanics on a high-strength fault. Static inversion of the coseismic displacements shows that the slip peaks at the same depth as the expected strength envelope, where the differential stresses can be as high as 600 MPa. Laboratory experiments on peridotite predict dramatic dynamic weakening at these conditions. The observed ordinary stress drop, 2-20 MPa, may indicate that the lithosphere is much weaker than strength envelope predicts or that the failure mechanisms seen in the laboratory are not occurring during the rupture. The GPS observations show very little postseismic signal indicating that if a shear zone exists beneath the coseismic rupture, it operates at significantly greater stress levels than the coseismic stress change.

  17. Using microearthquakes as probes of larger earthquake rupture

    NASA Astrophysics Data System (ADS)

    Rubinstein, Justin L.

    2006-04-01

    Although they garner very little attention from the public, microearthquakes are an extraordinarily valuable tool that seismologists use to understand better the physics underpinning faulting and earthquake rupture. Microearthquakes may not influence fault behavior on a large scale, but their ubiquitous nature has allowed me to determine precisely the time-dependent behavior of earth materials and to compute detailed descriptions of wave propagation, tasks which have significantly improved our understanding of fault slip and earthquake strong ground motion. The majority of this dissertation is dedicated to understanding nonlinear strong ground motion. To this end, I identify reductions in the near-surface seismic velocity coincident with four moderate and large earthquakes. Applying moving-window cross correlation on multiple repeating earthquake sequences allows me to identify these time dependent changes in seismic velocity. There are multiple lines of evidence that suggest that velocity reductions are evidence of nonlinear strong ground motion induced damage. First, velocity always decreases following earthquakes, which suggests a damage mechanism. The size of the velocity reductions that I observe are correlated with the strength of shaking for the earthquake that caused them, indicating a cause and effect relationship between strong ground motion and velocity reductions. For multiple earthquakes, I also identify a correlation between the size of velocity reductions and site conditions. This is expected; soft rocks are easier to damage with strong ground motion than hard rocks. The healing behavior of these velocity reductions also parallels the behavior of velocity reductions observed in laboratory studies of the recovery of materials from transient nonlinear strain. In the final chapter of this dissertation, I develop a new earthquake location technique. This method takes advantage of the expected similarity of the waveforms of nearby earthquakes to determine wave propagation parameters for many windows of time in a seismogram. This allows me to locate earthquakes that were sparsely recorded. I apply this technique to three medium magnitude earthquakes on the Calaveras Fault near streaks of seismicity. The new locations of these events suggest that streaks represent seismicity induced by the interaction between zones of a fault that accommodate slip differently, i.e., aseismically and seismically.

  18. Dynamics and materials physics of fault rupture and glacial processes

    NASA Astrophysics Data System (ADS)

    Platt, John Daniel

    This thesis focuses on two main topics, the physics governing how faults rapidly weaken during an earthquake and the thermal and mechanical structure of ice stream shear margins. The common theme linking these two projects is the desire to understand how the complicated interactions between stress and temperature control deformation and failure. All of the problems in this thesis are attacked using a combination of analytic and numerical methods, and the interplay between these two approaches provides a powerful way to understand the different physical balances that dominate in different regimes. We also use aspects of materials science to understand how the often complicated rheologies are controlled by underlying physical phenomena such as melting, phase transitions, diffusion, and dislocation motion. With regards to fault mechanics, we begin by showing how co-seismic weakening mechanisms driven by elevated pore fluid pressures lead to micron-scale strain localization during an earthquake. We solve for the localized zone thickness for a range of fault temperatures, test these predictions using numerical simulations, and show how the onset of localization accelerates fault weakening. Next we present the first solutions to account for thermal decomposition reactions during a dynamic rupture, showing that the activation of thermal decomposition may lead to a larger slip duration and total slip. Finally we present a new set of experiments studying flash heating of serpentinite, highlighting the dependence of friction on normal stress and the presence of gouge, and producing the first model to explain the hysteresis commonly observed in flash heating experiments. With regards to ice stream shear margins, we begin by extending the work of Perol and Rice [2011] to study the formation of temperate ice in shear margins, and quantify the total melt that may be generated within the shear margins. We conclude by investigating how the presence of such a channel alters the stress on and strength of the undeforming bed in the shear margin, showing that the transition from a deforming to an undeforming bed across a channel is stable when the water flux in the channel exceeds a critical value.

  19. Synthetic Augmented Suture Anchor Reconstruction for a Complete Traumatic Distal Triceps Tendon Rupture in a Male Professional Bodybuilder with Postoperative Biomechanical Assessment

    PubMed Central

    Nikolaidou, Maria-Elissavet; Banke, Ingo J.; Laios, Thomas; Petsogiannis, Konstantinos; Mourikis, Anastasios

    2014-01-01

    Bodybuilding is a high-risk sport for distal triceps tendon ruptures. Management, especially in high-demanding athletes, is operative with suture anchor refixation technique being frequently used. However, the rate of rerupture is high due to underlying poor tendon quality. Thus, additional augmentation could be useful. This case report presents a reconstruction technique for a complete traumatic distal triceps tendon rupture in a bodybuilder with postoperative biomechanical assessment. A 28-year-old male professional bodybuilder was treated with a synthetic augmented suture anchor reconstruction for a complete triceps tendon rupture of his right dominant elbow. Postoperative biomechanical assessment included isokinetic elbow strength and endurance testing by using multiple angular velocities to simulate the “off-season” and “precompetition” phases of training. Eighteen months postoperatively and after full return to training, the biomechanical assessment indicated that the strength and endurance of the operated elbow joint was fully restored with even higher ratings compared to the contralateral healthy arm. The described reconstruction technique can be considered as an advisable option in high-performance athletes with underlying poor tendon quality due to high tensile strength and lack of donor site morbidity, thus enabling them to restore preinjury status and achieve safe return to sports. PMID:24711944

  20. Synthetic augmented suture anchor reconstruction for a complete traumatic distal triceps tendon rupture in a male professional bodybuilder with postoperative biomechanical assessment.

    PubMed

    Nikolaidou, Maria-Elissavet; Banke, Ingo J; Laios, Thomas; Petsogiannis, Konstantinos; Mourikis, Anastasios

    2014-01-01

    Bodybuilding is a high-risk sport for distal triceps tendon ruptures. Management, especially in high-demanding athletes, is operative with suture anchor refixation technique being frequently used. However, the rate of rerupture is high due to underlying poor tendon quality. Thus, additional augmentation could be useful. This case report presents a reconstruction technique for a complete traumatic distal triceps tendon rupture in a bodybuilder with postoperative biomechanical assessment. A 28-year-old male professional bodybuilder was treated with a synthetic augmented suture anchor reconstruction for a complete triceps tendon rupture of his right dominant elbow. Postoperative biomechanical assessment included isokinetic elbow strength and endurance testing by using multiple angular velocities to simulate the "off-season" and "precompetition" phases of training. Eighteen months postoperatively and after full return to training, the biomechanical assessment indicated that the strength and endurance of the operated elbow joint was fully restored with even higher ratings compared to the contralateral healthy arm. The described reconstruction technique can be considered as an advisable option in high-performance athletes with underlying poor tendon quality due to high tensile strength and lack of donor site morbidity, thus enabling them to restore preinjury status and achieve safe return to sports. PMID:24711944

  1. Growth of Matrix Cracks During Intermediate Temperature Stress Rupture of a SiC/SiC Composite in Air

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.

    2000-01-01

    The crack density of woven Hi-Nicalon(sup TM) (Nippon Carbon, Japan) fiber, BN interphase, melt-infiltrated SiC matrix composites was determined for specimens subjected to tensile stress rupture at 815 C. A significant amount of matrix cracking occurs due to the growth of fiber-bridged microcracks even at stresses below the run-out condition. This increased cracking corresponded to time dependent strain accumulation and acoustic emission activity during the constant load test. However, the portion of the rupture specimens subjected to cooler temperatures (< 600 C than the hot section had significantly lower crack densities compared to the hotter regions. From the acoustic emission and time dependent strain data it can be inferred that most of the matrix crack growth occurred within the first few hours of the tensile rupture experiment. The crack growth was attributed to an interphase recession mechanism that is enhanced by the presence of a thin carbon layer between the fiber and the matrix as a result of the composite fabrication process. One important consequence of matrix crack growth at the lower stresses is poor retained strength at room temperature for specimens that did not fail.

  2. Stress-Rupture and Stress-Relaxation of SiC/SiC Composites at Intermediate Temperature

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurst, Janet; Levine, Stanley (Technical Monitor)

    2001-01-01

    Tensile static stress and static strain experiments were performed on woven Sylramic (Dow Corning, Midland, MI) and Hi-Nicalon (Nippon Carbon, Japan) fiber reinforced, BN interphase, melt-infiltrated SiC matrix composites at 815 C. Acoustic emission was used to monitor the damage accumulation during the test. The stress-rupture properties of Sylramic composites were superior to that of Hi-Nicalon Tm composites. Conversely, the applied strain levels that Hi-Nicalon composites can withstand for stress-relaxation experiments were superior to Sylramic composites; however, at a cost of poor retained strength properties for Hi-Nicalon composites. Sylramic composites exhibited much less stress-oxidation induced matrix cracking compared to Hi-Nicalon composites. This was attributed to the greater stiffness and roughness of Sylramic fibers themselves and the lack of a carbon layer between the fiber and the BN interphase for Sylramic composites, which existed in Hi-Nicalon composites. Due to the lack of stress-relief for Sylramic composites, time to failure for Sylramic composite stress-relaxation experiments was not much longer than for stress-rupture experiments when comparing the peak stress condition for stress-relaxation with the applied stress of stress-rupture.

  3. Reduction of bone strength

    NASA Technical Reports Server (NTRS)

    Bingham, Cindy

    1990-01-01

    Viewgraphs on reduction of bone strength are presented. WEHI 231 B growth rates, experimental chambers used to apply the electric field to the cell cultures, and a mouse suspended by rotating cuff in electromagnetic field are shown.

  4. Strength and Balance Exercises

    MedlinePLUS

    ... Blood Pressure Tools & Resources Stroke More Strength and Balance Exercises Updated:Jun 23,2015 If you have ... second set. Walking Heel-to-Toe Purpose: Improve balance. Starting Position: Stand close to a wall for ...

  5. Earthquake Rupture Complexity Evidence from Field Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.; Fletcher, J. M.; Rockwell, T. K.; Gonzalez-Garcia, J. J.; Teran, O.; Akciz, S. O.

    2010-12-01

    Field observations provide strong evidence for four intriguing aspects of rupture process complexity for the 4 April 2010 El Mayor - Cucapah - Indiviso earthquake. First, the southern “fork” of the rupture exhibits two splays just to the northwest of the event epicenter, both with nearly pure right-lateral faulting. Teleseismic source modeling by others indicates normal slip on deep fault surface preceded the shallow strike-slip faulting, and our field observations from the fork area indicate that the earliest phase of strike-slip faulting did not involve a significant normal faulting component. Second, as rupture propagated to the northwest along the Pescadores fault, slip ended abruptly on this fault and transferred across a complex zone to the Borrego fault (although the Pescadores fault continues farther and would have seemed an easier route to follow). This stepover is called the Puerta Accommodation Zone (PAZ) which extends 11 km along-strike within an elevated portion of the Cucapah massif and accommodates a left step (transpressional) that measures less than 2 km across-strike. Though partly obscured by rockfalls in the steep terrain here, only discontinuous faulting of up to one meter reached the ground surface, yet imagery differencing by others indicates several meters of continuous subsurface slip throughout this section. This 11 km region of reduced and discontinuous slip is one of the longest surface rupture jumps ever observed, with lengthy and continuous surface faulting on either side. The SE end of the stepover coincides spatially with the Canon Rojo embayment where the M7.2 1892 surface rupture propagated onto a second fault forming an abrupt corner in its surface trace. Hence, the surface rupture and slip distribution pattern in 2010 appears to have been influenced by stress changes induced by the 1892 event. Thirdly, from the NW end of the transition section, the Borrego fault continues to the NNW with strong east-down slip obliquity. Along this same reach of fault, the Laguna Salada fault was re-activated with minor west side down slip. Along the Paso Inferior accommodation zone, splays trending NNW to N had strong east-down slip, with right-lateral oblique motion. It was along this portion of the rupture that an eyewitness observed the rupture propagating from N to S, instead of in the expected S to N direction. Back-rupture may have resulted from triggered slip having raced ahead of the slower main rupture front, or may indicate a place where contiguous deep rupture ran out in front of shallow slip, or may result from the involvement here of the detachment fault system. Finally, in the northwestern portion of the rupture, from Paso Superior to the northwest of Cerro Centinela, a pattern of NE - SW oriented “cross faults” and N-S faults broke at the surface, in a manner similar to rupture that occurred in the Elmore Ranch Fault Zone during the Superstition Hills earthquake sequence of 1987. Unlike the Elmore Ranch event, however, there was no known main shock sub-event or any large aftershock that can be readily associated with the extensive cross-faulting that is observed in this case.

  6. Near-Source Shaking and Dynamic Rupture in Plastic Media

    NASA Astrophysics Data System (ADS)

    Gabriel, A.; Mai, P. M.; Dalguer, L. A.; Ampuero, J. P.

    2012-12-01

    Recent well recorded earthquakes show a high degree of complexity at the source level that severely affects the resulting ground motion in near and far-field seismic data. In our study, we focus on investigating source-dominated near-field ground motion features from numerical dynamic rupture simulations in an elasto-visco-plastic bulk. Our aim is to contribute to a more direct connection from theoretical and computational results to field and seismological observations. Previous work showed that a diversity of rupture styles emerges from simulations on faults governed by velocity-and-state-dependent friction with rapid velocity-weakening at high slip rate. For instance, growing pulses lead to re-activation of slip due to gradual stress build-up near the hypocenter, as inferred in some source studies of the 2011 Tohoku-Oki earthquake. Moreover, off-fault energy dissipation implied physical limits on extreme ground motion by limiting peak slip rate and rupture velocity. We investigate characteristic features in near-field strong ground motion generated by dynamic in-plane rupture simulations. We present effects of plasticity on source process signatures, off-fault damage patterns and ground shaking. Independent of rupture style, asymmetric damage patterns across the fault are produced that contribute to the total seismic moment, and even dominantly at high angles between the fault and the maximum principal background stress. The off-fault plastic strain fields induced by transitions between rupture styles reveal characteristic signatures of the mechanical source processes during the transition. Comparing different rupture styles in elastic and elasto-visco-plastic media to identify signatures of off-fault plasticity, we find varying degrees of alteration of near-field radiation due to plastic energy dissipation. Subshear pulses suffer more peak particle velocity reduction due to plasticity than cracks. Supershear ruptures are affected even more. The occurrence of multiple rupture fronts affect seismic potency release rate, amplitude spectra, peak particle velocity distributions and near-field seismograms. Our simulations enable us to trace features of source processes in synthetic seismograms, for example exhibiting a re-activation of slip. Such physical models may provide starting points for future investigations of field properties of earthquake source mechanisms and natural fault conditions. In the long-term, our findings may be helpful for seismic hazard analysis and the improvement of seismic source models.

  7. Composite Overwrapped Pressure Vessels (COPV) Stress Rupture Test

    NASA Technical Reports Server (NTRS)

    Russell, Richard; Flynn, Howard; Forth, Scott; Greene, Nathanael; Kezian, Michael; Varanauski, Don; Yoder, Tommy; Woodworth, Warren

    2009-01-01

    One of the major concerns for the aging Space Shuttle fleet is the stress rupture life of composite overwrapped pressure vessels (COPVs). Stress rupture life of a COPV has been defined as the minimum time during which the composite maintains structural integrity considering the combined effects of stress levels and time. To assist in the evaluation of the aging COPVs in the Orbiter fleet an analytical reliability model was developed. The actual data used to construct this model was from testing of COPVs constructed of similar, but not exactly same materials and pressure cycles as used on Orbiter vessels. Since no actual Orbiter COPV stress rupture data exists the Space Shuttle Program decided to run a stress rupture test to compare to model predictions. Due to availability of spares, the testing was unfortunately limited to one 40" vessel. The stress rupture test was performed at maximum operating pressure at an elevated temperature to accelerate aging. The test was performed in two phases. The first phase, 130 F, a moderately accelerated test designed to achieve the midpoint of the model predicted point reliability. The more aggressive second phase, performed at 160 F was designed to determine if the test article will exceed the 95% confidence interval of the model. This paper will discuss the results of this test, it's implications and possible follow-on testing.

  8. Spontaneous Flexor Tendon Rupture Due to Atraumatic Chronic Carpal Instability

    PubMed Central

    Miranda, B. H.; Cerovac, S.

    2014-01-01

    Background?Spontaneous flexor tendon rupture is considered to be invariably associated with previous hand/wrist injury or systemic disease such as rheumatoid arthritis. Case Description?A 54-year-old man presented with a 4-month history of mild ulnar wrist pain and spontaneous left little finger flexion loss in the absence of distant/recent trauma and systemic arthropathy. Surgical exploration confirmed a zone IV left little finger flexor digitorum profundus (FDP5) attritional rupture (100%), ring finger flexor digitorum profundus (FDP4) attenuation (40%) and a disrupted lunotriquetral ligament and volar-ulnar wrist capsule. Volar subluxation of the narrowed carpal tunnel resulted in flexor tendon attrition against the hamate hook. A side-to-side tendon transfer was performed along with a lunotriquetral ligament repair and temporary Kirschner wire fixation. At 6 months the patient had full active, synchronous flexion of the ring and little fingers and reduced wrist pain. Literature Review?Traumatic flexor tendon ruptures have been reported following distal radius/hamate hook fractures, from carpal bone osteophytes, accessory carpal bones and intraosseous ganglia. Attritional ruptures caused by chronic, degenerative carpal pathology are less common. Clinical Relevance?This case highlights an unusual cause of flexor tendon rupture due to chronic carpal instability. PMID:25032080

  9. Spontaneous Atraumatic Extensor Pollicis Longus Rupture in the Nonrheumatoid Population

    PubMed Central

    Rada, Erin M.; Shridharani, Sachin M.; Lifchez, Scott D.

    2013-01-01

    Introduction: Extensor pollicis longus (EPL) tendon rupture is a well-described phenomenon in patients with rheumatoid arthritis. Mechanisms of EPL tendon rupture in the nonrheumatoid population have also been described and include traumatic rupture, repetitive motion strain, and steroid injection into the tendon. Methods: The operative records for patients undergoing extensor pollicis longus reconstruction by the senior author were reviewed. Patients with a history of trauma to the wrist or inflammatory arthropathy were excluded. Results: We identified 3 patients who presented with spontaneous EPL tendon rupture. These patients reported no risk factors (as listed earlier) or inciting event. All 3 patients had some exposure to local steroids but this exposure was not at the site of subsequent tendon rupture. All patients were operatively repaired and went on to full recovery of EPL function. Discussion: In patients with sudden loss of extension of the thumb interphalangeal joint, a thorough history of steroid exposure including local steroid exposure remote to the affected EPL tendon may be relevant. PMID:23460929

  10. Rupture of an evaporating liquid bridge between two grains

    NASA Astrophysics Data System (ADS)

    Mielniczuk, Boleslaw; El Youssoufi, Moulay; Sabatier, Laurent; Hueckel, Tomasz

    2014-10-01

    The study examines rupture of evaporating liquid bridges between two glass spheres. Evolution of the bridge profile has been recorded with the use of high-speed camera. Geometrical characteristics of the bridge were then used to calculate evolution of the variables during the process: Laplace pressure, capillary force, and surface tension force. For the purpose of reference, the bridge evolution is followed also during kinematic extension. During both processes the diameter of the neck decreases, with an acceleration of about 1-2 ms before the rupture. Two distinct rupture modes are observed, depending on the bridge aspect ratio. After the rupture, the mass of liquid splits, forming two separate oscillating drops attached to the spheres, and a suspended satellite droplet. Just before the rupture, an increasing repulsive Laplace pressure, and decreasing negative surface tension force develop. Capillary force follows the trend of the surface tension force, with an accelerating decline. Duration of the whole process and liquid mass stabilization is from 10 to 60 ms.

  11. Two cases of spontaneous liver rupture and literature review.

    PubMed

    Cozzi, P J; Morris, D L

    1996-01-01

    Spontaneous liver rupture is uncommon, difficult to diagnose and carries a universally high mortality. It has been well documented to occur as a complication of primary or secondary hepatic malignancy. Similarly, there are 28 cases of ruptured haemangiomata described in the world literature. It is also well described in severe pregnancy-induced hypertension and is said to carry a mortality of 18% for patients treated by packing and drainage of the haematoma and 75% for patients treated with liver resection. Two female patients aged 60 and 61 presented to our accident and emergency department. One had a history of hypertension only and the other a history of a bleeding diathesis from the lupus anticoagulant. Both presented with hypotension and abdominal pain and both were diagnosed by abdominal CT scan. One was treated with hepatic artery ligation and tamponade and the other with liver resection and correction of the coagulopathy. Neither had any evidence of a ruptured hemangioma or tumor at laparotomy or on histological examination, and both are alive and well. The conclusions to be drawn from this review and our own recent experience is that the treatment of choice for ruptured haemangiomata is liver resection and, for rupture during pregnancy, is tamponade with packs and evacuation of the haematoma. Hepatic arteriography and embolisation, if possible, is a useful adjunct. Correction of any coagulopathy is essential. We can only speculate that the aetiology in our patients was uncontrolled hypertension in one and coagulopathy in the other. PMID:8809590

  12. Apple Strength Issues

    SciTech Connect

    Syn, C

    2009-12-22

    Strength of the apple parts has been noticed to decrease, especially those installed by the new induction heating system since the LEP campaign started. Fig. 1 shows the ultimate tensile strength (UTS), yield strength (YS), and elongation of the installed or installation-simulated apples on various systems. One can clearly see the mean values of UTS and YS of the post-LEP parts decreased by about 8 ksi and 6 ksi respectively from those of the pre-LEP parts. The slight increase in elongation seen in Fig.1 can be understood from the weak inverse relationship between the strength and elongation in metals. Fig.2 shows the weak correlation between the YS and elongation of the parts listed in Fig. 1. Strength data listed in Figure 1 were re-plotted as histograms in Figs. 3 and 4. Figs. 3a and 4a show histograms of all UTS and YS data. Figs. 3b and 4b shows histograms of pre-LEP data and Figs. 3c and 4c of post-LEP data. Data on statistical scatter of tensile strengths have been rarely published by material suppliers. Instead, only the minimum 'guaranteed' strength data are typically presented. An example of strength distribution of aluminum 7075-T6 sheet material, listed in Fig. 5, show that its scatter width of both UTS and YS for a single sheet can be about 6 ksi and for multi-lot scatter can be as large as 11 ksi even though the sheets have been produced through well-controlled manufacturing process. By approximating the histograms shown in Figs. 3 and 4 by a Gaussian or similar type of distribution curves, one can plausibly see the strength reductions in the later or more recent apples. The pre-LEP data in Figs. 3b and 4b show wider scatter than the post-LEP data in Figs. 3c and 4c and seem to follow the binomial distribution of strength indicating that the apples might have been made from two different lots of material, either from two different vendors or from two different melts of perhaps slightly different chemical composition by a single vendor. The post-LEP apples seem to have been from a single batch of material. The pre-LEP apples of the weak strength and the post-LEP apples with even weaker strength could have been made of the same batch of material, and the small strength differential might be due to the difference in the induction heating system. If the pre-LEP apples with the lower strength and the post LEP apples are made from the same batch of material, their combined scatter of strength data would be wider and can be understood as a result of the additional processing steps of stress relief and induction heating as discussed.

  13. Radiographic Risk Factors for Contralateral Rupture in Dogs with Unilateral Cranial Cruciate Ligament Rupture

    PubMed Central

    Chuang, Connie; Ramaker, Megan A.; Kaur, Sirjaut; Csomos, Rebecca A.; Kroner, Kevin T.; Bleedorn, Jason A.; Schaefer, Susan L.; Muir, Peter

    2014-01-01

    Background Complete cranial cruciate ligament rupture (CR) is a common cause of pelvic limb lameness in dogs. Dogs with unilateral CR often develop contralateral CR over time. Although radiographic signs of contralateral stifle joint osteoarthritis (OA) influence risk of subsequent contralateral CR, this risk has not been studied in detail. Methodology/Principal Findings We conducted a retrospective longitudinal cohort study of client-owned dogs with unilateral CR to determine how severity of radiographic stifle synovial effusion and osteophytosis influence risk of contralateral CR over time. Detailed survival analysis was performed for a cohort of 85 dogs after case filtering of an initial sample population of 513 dogs. This population was stratified based on radiographic severity of synovial effusion (graded on a scale of 0, 1, and 2) and severity of osteophytosis (graded on a scale of 0, 1, 2, and 3) of both index and contralateral stifle joints using a reproducible scoring method. Severity of osteophytosis in the index and contralateral stifles was significantly correlated. Rupture of the contralateral cranial cruciate ligament was significantly influenced by radiographic OA in both the index and contralateral stifles at diagnosis. Odds ratio for development of contralateral CR in dogs with severe contralateral radiographic stifle effusion was 13.4 at one year after diagnosis and 11.4 at two years. Odds ratio for development of contralateral CR in dogs with severe contralateral osteophytosis was 9.9 at one year after diagnosis. These odds ratios were associated with decreased time to contralateral CR. Breed, age, body weight, gender, and tibial plateau angle did not significantly influence time to contralateral CR. Conclusion Subsequent contralateral CR is significantly influenced by severity of radiographic stifle effusion and osteophytosis in the contralateral stifle, suggesting that synovitis and arthritic joint degeneration are significant factors in the disease mechanism underlying the arthropathy. PMID:25254499

  14. Achievable Transverse Cylindrical Electromagnetic Mode

    E-print Network

    R. Chen; X. Li

    2011-06-04

    The system of Maxwell equations with an initial condition in a vacuum is solved in a cylindrical coordinate system. It derives the cylindrical transverse electromagnetic wave mode in which the electric field and magnetic field are not in phase. Such electromagnetic wave can generate and exist in actual application, and there is no violation of the law of conservation of energy during the electromagnetic field interchanges.

  15. Transverse momentum distributions of hadrons

    SciTech Connect

    Jacak, B.

    1990-01-01

    The study of hadron production in heavy ion collisions is essential to the search for effects beyond independent nucleon-nucleon collisions, for example the predicted phase transition to quark matter. Hadron distributions are known over a large range of transverse momenta for p-p collisions, so a careful study of the differences can be made. The transverse momentum distributions of hadrons may provide global information about p-nucleus and nucleus-nucleus collisions, such as the degree of thermalization achieved, and perhaps provide evidence for collective expansion of the highly excited central region. Comparison of the p{sub t} and transverse mass, m{sub t}, distributions of different hadronic species are crucial to extract this kind of information. Hadronic p{sub t} spectra show effects of the collision dynamics, such as hard scattering processes, and possibly rescattering of partons as well as of the formed hadrons. Such modifications have been observed in p-nucleus collisions, and can be expected to be important in nucleus-nucleus reactions. The spectral shape changes arising in this manner cause a background in efforts to extract global information from hadronic p{sub t} spectra. Lastly, there is an excess of pions observed at low p{sub t} in p-A and A-A collisions. the origin of these soft pions is not yet well understood. The phenomenon represents a major difference between p-p and nuclear collisions. 31 refs., 8 figs.

  16. Counter-intuitive Behavior of Subduction Zones: Weak Faults Rupture, Strong Faults Creep

    NASA Astrophysics Data System (ADS)

    Wang, K.; Gao, X.; Bilek, S. L.; Brown, L. N.

    2014-12-01

    Subduction interfaces that produce great earthquakes are often said to be "strongly coupled", and those that creep are said to be "weakly coupled". However, the relation between the strength and seismogenic behavior of subduction faults is far from clear. Seismological and geodetic observations of earthquake rupture usually provide information only on stress change, not fault strength. In this study, we infer fault strength by calculating frictional heating along megathrusts and comparing results with heat flow measurements. We find that stick-slip megathrusts that have produced great earthquakes such as at Japan Trench and northern Sumatra have very low apparent friction coefficients (~ 0.02 - 0.03), but megathrusts that creep such as at Northern Hikurangi and Manila Trench have higher values (up to ~0.13). The differnce cannot be explained by coseismic dynamic weakening of the stick-slip megathrusts, because the average stress drop in great earthquakes is usually less than 5 MPa, equivalent to a coseismic reduction of apparent friction coefficient by less than ~0.01. Therefore our results indicate differences in the static strength of different subduction faults. Why are the creeping faults stronger? We think it is related to their creeping mechanism. Very rugged subducting seafloor tends to cause creep and hinder great earthquake rupture (Wang and Bilek, 2014). In contrast, all giant earthquakes have occurred at subduction zones with relatively smooth subducting seafloor. Large geometrical irregularities such as seamounts generate heterogeneous structure and stresses that promote numerous small and medium size earthquakes and aseismic creep. The creeping is a process of breaking and wearing of geometrical irregularities in a deformation zone and is expected to be against relatively large resistance (strong creep). This is different from the creeping of smooth faults due to the presence of weak fault gouge (weak creep) such as along the creeping segment of the San Andreas fault. The general correlation between subducting seafloor ruggedness, creeping, and greater heat dissipation, if further verified, provides a new perspective in assessing earthquake and tsunami hazards for risk mitigation. Wang, K., and S. L. Bilek. Tectonophysics 610, 1-24 (2014).

  17. Activation of Fault Structures South of the La Habra Earthquake Rupture As Evidenced By UAVSAR Imaging

    NASA Astrophysics Data System (ADS)

    Donnellan, A.; Parker, J. W.; Grant Ludwig, L.; Hauksson, E.

    2014-12-01

    The 28 March, 2014 M 5.2 La Habra earthquake occurred on a northeast striking, northwest dipping left-lateral oblique thrust fault at the northeastern margin of the LA Basin, where regional right-lateral shear is accommodated by major northwest trending faults of the Peninsular Ranges, and north-south shortening is accommodated by north-dipping thrust faults and east-west trending folds of the Transverse Ranges. The La Habra mainshock location and focal mechanism is northwest of but sub-parallel to the Puente Hills thrust fault. Relocated seismicity highlights a northeast-trending rupture plane consistent with the magnitude and focal mechanism of the event. NASA's UAVSAR L-Band radar instrument was flown for north and south looking lines before the earthquake on 22 January 2014. The north looking line was reflown three days after the earthquake on 31 March, 2014, and the south looking line was reflown a week later on 4 April 2014. The UAVSAR Repeat Pass Interferogram (RPI) products show deformation consistent with the location of the mainshock beneath the town of La Habra. The results also show considerable aseismic northward horizontal deformation with minor uplift in the West Coyote Hills, south of the relocated seismicity. Inversion of the combined interferograms is consistent with south dipping low-angle (7°) shallow slip that corresponds to bedding plane attitudes and a mapped unconformity. The entire West Coyote Hills show 37 mm of modeled northward slip with an additional 34 mm of modeled slip concentrated near the Coyote Hills Park northeast of the intersection of Rosecrans Avenue and North Gilbert Street. A narrow band of shortening was also observed with UAVSAR, and confirmed with on-the-ground field observations, at the Trojan Way Kink Band, nearly one fault dimension southwest of the main rupture.

  18. Composite Overwrapped Pressure Vessel (COPV) Stress Rupture Testing

    NASA Technical Reports Server (NTRS)

    Greene, Nathanael J.; Saulsberry, Regor L.; Leifeste, Mark R.; Yoder, Tommy B.; Keddy, Chris P.; Forth, Scott C.; Russell, Rick W.

    2010-01-01

    This paper reports stress rupture testing of Kevlar(TradeMark) composite overwrapped pressure vessels (COPVs) at NASA White Sands Test Facility. This 6-year test program was part of the larger effort to predict and extend the lifetime of flight vessels. Tests were performed to characterize control parameters for stress rupture testing, and vessel life was predicted by statistical modeling. One highly instrumented 102-cm (40-in.) diameter Kevlar(TradeMark) COPV was tested to failure (burst) as a single-point model verification. Significant data were generated that will enhance development of improved NDE methods and predictive modeling techniques, and thus better address stress rupture and other composite durability concerns that affect pressure vessel safety, reliability and mission assurance.

  19. Silent Spontaneous Uterine Rupture at 36 Weeks of Gestation

    PubMed Central

    Woo, J. Y.; Tate, L.; Roth, S.; Eke, A. C.

    2015-01-01

    Introduction. Silent spontaneous rupture of the uterus before term, with extrusion of an intact amniotic sac and delivery of a healthy neonate, with no maternal or neonatal morbidity or mortality is very rare. Very few cases have been reported in literature. Case Presentation. We report a case of silent spontaneous uterine rupture, found during a scheduled repeat cesarean section at 36 weeks of gestation. Patient had history of two prior classical cesarean sections. She underwent cesarean section, with delivery of a healthy male infant. She had a good postoperative recovery and was discharged on postoperative day 3. Conclusion. Silent spontaneous rupture of the uterus before term with extrusion of an intact amniotic sac is rare. A high index of suspicion and good imaging during pregnancy are important in making this diagnosis. PMID:26357580

  20. Spontaneous rupture of a hepatic angiomyolipoma: Report of a case.

    PubMed

    Aoki, Hideki; Arata, Takashi; Morihiro, Toshiaki; Kanaya, Nobuhiko; Takeda, Sho; Sui, Kenta; Shigeyasu, Kunitoshi; Katsuda, Koh; Tanakaya, Kohji; Takeuchi, Hitoshi

    2014-10-01

    A 70-year-old female experienced sudden onset of back pain on the right side and was admitted to our hospital in December 2010. Abdominal computed tomography revealed an S7 hepatic mass measuring 7 cm in diameter accompanied by a subcapsular hematoma. Emergency angiography confirmed the diagnosis of a ruptured hepatic mass, and hemostasis was carried out by embolization of A8 and A7 of the liver. A right hepatic lobectomy was carried out 39 days following transarterial embolization. Although almost all aspects of the tumor were necrotic, residual tumor cells stained positive for HMB-45, and negative for ?-SMA, S-100, CD 34, c-kit, CAM 5.2, and hepatocytes. The MIB-1 index was 2 %. Pathological diagnosis was hepatic angiomyolipoma (HAML). The patient has shown no signs of recurrence at 42 months following surgery. Here, we report on this case of spontaneous HAML rupture and discuss therapeutic strategies for HAML and ruptured hepatic tumors. PMID:26184024

  1. Predictors and clinical outcomes for spontaneous rupture of hepatocellular carcinoma

    PubMed Central

    Zhu, Qian; Li, Jing; Yan, Jian-Jun; Huang, Liang; Wu, Meng-Chao; Yan, Yi-Qun

    2012-01-01

    AIM: To determine the risk factors for hepatocellular carcinoma (HCC) rupture, and report the management and long-term survival results of patients with spontaneous rupture of HCC. METHODS: Among 4209 patients with HCC who were diagnosed at Eastern Hepatobiliary Surgery Hospital from April 2002 to November 2006, 200 (4.8%) patients with ruptured HCC (case group) were studied retrospectively in term of their clinical characteristics and prognostic factors. The one-stage therapeutic approach to manage ruptured HCC consisted of initial management by conservative treatment, transarterial embolization (TACE) or hepatic resection. Results of various treatments in the case group were evaluated and compared with the control group (202 patients) without ruptured HCC during the same study period. Continuous data were expressed as mean ± SD or median (range) where appropriate and compared using the unpaired t test. Categorical variables were compared using the Chi-square test with Yates correction or the Fisher exact test where appropriate. The overall survival rate in each group was determined using the Kaplan-Meier method and a log-rank test. RESULTS: Compared with the control group, more patients in the case group had underlying diseases of hypertension (7.5% vs 3.0%, P =0.041) and liver cirrhosis (87.5% vs 56.4%, P < 0.001), tumor size >5 cm (83.0% vs 57.4%, P < 0.001), tumor protrusion from the liver surface (66.0% vs 44.6%, P < 0.001), vascular thrombus (30.5% vs 8.9%, P < 0.001) and extrahepatic invasion (36.5% vs 12.4%, P < 0.001). On multivariate logistic regression analysis, underlying diseases of hypertension (P = 0.002) and liver cirrhosis (P < 0.001), tumor size > 5 cm (P < 0.001), vascular thrombus (P = 0.002) and extrahepatic invasion (P < 0.001) were predictive for spontaneous rupture of HCC. Among the 200 patients with spontaneous rupture of HCC, 105 patients underwent hepatic resection, 33 received TACE, and 62 were managed with conservative treatment. The median survival time (MST) of all patients with spontaneous rupture of HCC was 6 mo (range, 1-72 mo), and the overall survival at 1, 3 and 5 years were 32.5%, 10% and 4%, respectively. The MST was 12 mo (range, 1-72 mo) in the surgical group, 4 mo (range, 1-30 mo) in the TACE group and 1 mo (range, 1-19 mo) in the conservative group. Ninety-eight patients in the control group underwent hepatic resection, and the MST and median disease-free survival time were 46 mo (range, 6-93 mo) and 23 mo (range, 3-39 mo) respectively, which were much longer than that of patients with spontaneous rupture of HCC undergoing hepatic resection (P < 0.001). The 1-, 3-, and 5-year overall survival rates and the 1-, 3- and 5-year disease-free survival rates in patients with ruptured HCC undergoing hepatectomy were 57.1%, 19.0% and 7.6%, 27.6%, 14.3% and 3.8%, respectively, compared with those of 77.1%, 59.8% and 41.2%, 57.1%, 40.6% and 32.9% in 98 patients without ruptured HCC undergoing hepatectomy (P < 0.001). CONCLUSION: Prolonged survival can be achieved in selected patients undergoing one-stage hepatectomy, although the survival results were inferior to those of the patients without ruptured HCC. PMID:23326137

  2. Transcatheter Arterial Embolization for Spontaneous Rupture of the Omental Artery

    SciTech Connect

    Matsumoto, Tomohiro; Yamagami, Takuji; Morishita, Hiroyuki; Iida, Shigeharu; Tazoe, Jun; Asai, Shunsuke; Masui, Koji; Ikeda, Jun; Nagata, Akihiro; Sato, Osamu; Nishimura, Tsunehiko

    2011-02-15

    We encountered a rare case of spontaneous rupture of the omental artery. A 25-year-old man without any episode of abdominal trauma or bleeding disorders came to the emergency unit with left upper abdominal pain. Hematoma with extravasation of the greater omentum and a hemoperitoneum was confirmed on abdominal contrast-enhanced computed tomography. Bleeding from the omental artery was suspected based on these findings. Transcatheter arterial embolization was successfully performed after extravasation of the omental artery, which arises from the left gastroepiploic artery, was confirmed on arteriography. Partial ometectomy was performed 10 days after transcatheter arterial embolization, revealing that the hematoma measured 10 cm in diameter in the greater omentum. Pathological examination showed rupture of the branch of an omental artery without abnormal findings, such as an aneurysm or neoplasm. Thus, we diagnosed him with spontaneous rupture of the omental artery. The patient recovered and was discharged from the hospital 10 days after the surgery, with a favorable postoperative course.

  3. Acute airway compromise due to ruptured inferior thyroid artery aneurysm.

    PubMed

    Coskun, Zerrin Ozerg?n; Yava?i, Özcan; Durakoglugil, Tugba; Celebi Erdivanli, Ozlem; Ozgur, Abdulkadir; Terzi, Suat; Dursun, Engin

    2015-08-01

    A cervical hematoma secondary to the spontaneous rupture of an aneurysm is an uncommon but catastrophic life-threatening condition because it can potentially obstruct the airway. Inferior thyroid artery aneurysm and rupture is a very rare clinical entity and only a limited number of cases have been reported in the literature. In this article, we present the case of a female patient who suffered from a rapidly enlarging cervical mass followed by a rapid onset of dyspnea as a result of rupture of an inferior thyroid artery aneurysm. The diagnosis was confirmed by magnetic resonance angiography, and delayed surgery resulted in an uneventful outcome. We aim to draw the attention of emergency physicians to this rare condition. PMID:25770593

  4. Emergency Stenting of a Ruptured Infected Anastomotic Femoral Pseudoaneurysm

    SciTech Connect

    Klonaris, Chris Katsargyris, Athanasios; Matthaiou, Alexandros; Giannopoulos, Athanasios; Tsigris, Chris; Papadopouli, Katerina; Tsiodras, Sotiris; Bastounis, Elias

    2007-11-15

    A 74-year-old man presented with a ruptured infected anastomotic femoral pseudoaneurysm. Due to severe medical comorbidities he was considered unsuitable for conventional surgical management and underwent an emergency endovascular repair with a balloon-expandable covered stent. The pseudoaneurysm was excluded successfully and the patient had an uneventful postoperative recovery with long-term suppressive antimicrobials. He remained well for 10 months after the procedure with no signs of recurrent local or systemic infection and finally died from an acute myocardial infarction. To our knowledge, emergency endovascular treatment of a free ruptured bleeding femoral artery pseudoaneurysm has not been documented before in the English literature. This case illustrates that endovascular therapy may be a safe and efficient alternative in the emergent management of ruptured infected anastomotic femoral artery pseudoaneurysms when traditional open surgery is contraindicated.

  5. Ruptured Mycotic Aortic Aneurysm after Bacille Calmette-Guerin Therapy.

    PubMed

    Floros, Nikolaos; Meletiadis, Konstantinos; Kusenack, Ulrich; Zirngibl, Hubert; Kamper, Lars; Haage, Patrick; Dreger, Nici Markus

    2015-10-01

    To report a case of a ruptured mycotic abdominal aortic aneurysm (MAA) after intravesical Bacille Calmette-Guerin (BCG) therapy because of bladder carcinoma. A 57-year-old male patient was admitted to our hospital for follow-up computed tomography 14 months after transurethral resection of a papillary carcinoma of the bladder and intravesical BCG therapy. The CT scan revealed a ruptured MAA aneurysm and the patient underwent an endovascular repair with an aorto-bi-iliac stent graft. A ruptured MAA is a rare but lethal complication after BCG instillation therapy. The standard therapy is the open reconstruction but according to the literature an endovascular therapy in combination with long-term antibiotics should be considered as a bridging or a definite solution. PMID:26119640

  6. Premature rupture of the membranes: a cause for neonatal osteomyelitis?

    PubMed

    Liao, Sui-Ling; Lai, Shen Hao; Lin, Tzo-Yen; Chou, Yi-Hong; Hsu, Jen-Fu

    2005-02-01

    Osteomyelitis is rare in the neonatal period. Many etiologic factors for causing neonatal osteomyelitis have been discussed in the literature; however, premature rupture of the membranes has never been emphasized. We report on a neonate with osteomyelitis of the right humerus infected with an uncommon pathogen, Klebsiella pneumonia. In the absence of any perinatal disease, premature rupture of the membranes was suggested to be the cause of the illness. The infant was initially regarded as having Erb palsy because of the absence of systemic symptoms and lack of perinatal high-risk factors. Antibiotic administration was delayed for 3 weeks. Luckily, nearly complete recovery was noted after 2 months of follow up. We emphasize the importance of considering osteomyelitis in a newborn infant with limb palsy, particularly in the presence of premature rupture of the membranes of the mother. We also discuss the results of the microbial examination and significance of magnetic resonance imaging in neonatal osteomyelitis. PMID:15731982

  7. QCD Evolution of Helicity and Transversity TMDs

    SciTech Connect

    Prokudin, Alexei

    2014-01-01

    We examine the QCD evolution of the helicity and transversity parton distribution functions when including also their dependence on transverse momentum. Using an appropriate definition of these polarized transverse momentum distributions (TMDs), we describe their dependence on the factorization scale and rapidity cutoff, which is essential for phenomenological applications.

  8. 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

    NASA Astrophysics Data System (ADS)

    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.

  9. Rapid aneurysm growth and rupture in systemic lupus erythematosus

    PubMed Central

    Graffeo, Christopher S.; Tanweer, Omar; Nieves, Cesar Fors; Belmont, H. Michael; Izmirly, Peter M.; Becske, Tibor; Huang, Paul P.

    2015-01-01

    Background: Subarachnoid hemorrhage (SAH) due to intracranial aneurysm rupture is a major neurosurgical emergency associated with significant morbidity and mortality. Rapid aneurysm growth is associated with rupture. Systemic lupus erythematosus (SLE) is a multi-system autoimmune disorder whose complications can include cerebral vasculitis and vasculopathy. Intracranial aneurysms are not known to occur more frequently in SLE patients than the general population; however, aneurysm growth rates have not been studied in SLE. Case Description: We present a 43-year-old female with SLE on prednisone, hydroxychloroquine, and azathioprine with moderate disease activity who presented with severe, acute-onset headache and was found to have Hunt and Hess grade II SAH due to rupture of an 8 mm saccular anterior communicating artery (ACoA) aneurysm. The patient developed severe vasospasm, re-ruptured, and was taken for angiography and embolization, which was challenging due to a high degree of vasospasm and arterial stenosis. Review of imaging from less than 2 years prior demonstrated a normal ACoA complex without evidence of an aneurysm. Conclusion: We review the literature and discuss the risk factors and pathophysiology of rapid aneurysm growth and rupture, as well as the pathologic vascular changes associated with SLE. Although SLE patients do not develop intracranial aneurysm at an increased rate, these changes may predispose them to higher incidence of growth and rupture. This possibility-coupled with increased morbidity and mortality of SAH in SLE-suggests that SAH should be considered in SLE patients presenting with headache, and advocates for more aggressive treatment of SLE patients with unruptured aneurysms. PMID:25657862

  10. PIP breast implants: rupture rate and correlation with breast cancer

    PubMed Central

    MOSCHETTA, M.; TELEGRAFO, M.; CORNACCHIA, I.; VINCENTI, L.; RANIERI, V.; CIRILLI, A.; RELLA, L.; IANORA, A.A. STABILE; ANGELELLI, G.

    2014-01-01

    Aim To evaluate the incidence of Poly Implant Prosthése (PIP) rupture as assessed by magnetic resonance imaging (MRI), the prevalence of the detected signs and the potential correlation with breast carcinoma. Patients and methods 67 patients with silicone breast implants and clinical indications for breast MRI were evaluated for a total of 125 implants: 40 (32%) PIP in 21 patients and 85 non-PIP in 46 patients (68%), the latest considered as control group. A 1.5-T MR imaging device was used in order to assess implant integrity with dedicated sequences and in 6 cases a dynamic study was performed for characterizing breast lesions. Two radiologists with more than 5 years’ experience in the field of MRI evaluated in consensus all MR images searching for the presence of clear signs of intra or extra-capsular implant rupture. Results 20/40 (50%) PIP implants presented signs of intra-capsular rupture: linguine sign in 20 cases (100%), tear-drop sign in 6 (30%). In 12/20 cases (60%), MRI signs of extra-capsular rupture were detected. In the control group, an intra-capsular rupture was diagnosed in 12/85 cases (14%) associated with extra-capsular one in 5/12 cases (42%). Among the six cases with suspected breast lesions, in 2/21 patients with PIP implants (10%) a breast carcinoma was diagnosed (mucinous carcinoma, n=1; invasive ductal carcinoma, n=1). In 4/46 patients (9%) with non-PIP implants, an invasive ductal carcinoma was diagnosed. Conclusion The rupture rate of PIP breast implants is significantly higher than non-PIP (50% vs 14%). MRI represents the most accurate imaging tool for evaluating breast prostheses and the linguine sign is the most common MRI sign to be searched. The incidence of breast carcinoma does not significantly differ between the PIP and non-PIP implants and a direct correlation with breast cancer can not been demonstrated. PMID:25644728

  11. Frequency-Dependent Rupture Processes for the 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Miyake, H.

    2012-12-01

    The 2011 Tohoku earthquake is characterized by frequency-dependent rupture process [e.g., Ide et al., 2011; Wang and Mori, 2011; Yao et al., 2011]. For understanding rupture dynamics of this earthquake, it is extremely important to investigate wave-based source inversions for various frequency bands. The above frequency-dependent characteristics have been derived from teleseismic analyses. This study challenges to infer frequency-dependent rupture processes from strong motion waveforms of K-NET and KiK-net stations. The observations suggested three or more S-wave phases, and ground velocities at several near-source stations showed different arrivals of their long- and short-period components. We performed complex source spectral inversions with frequency-dependent phase weighting developed by Miyake et al. [2002]. The technique idealizes both the coherent and stochastic summation of waveforms using empirical Green's functions. Due to the limitation of signal-to-noise ratio of the empirical Green's functions, the analyzed frequency bands were set within 0.05-10 Hz. We assumed a fault plane with 480 km in length by 180 km in width with a single time window for rupture following Koketsu et al. [2011] and Asano and Iwata [2012]. The inversion revealed source ruptures expanding from the hypocenter, and generated sharp slip-velocity intensities at the down-dip edge. In addition to test the effects of empirical/hybrid Green's functions and with/without rupture front constraints on the inverted solutions, we will discuss distributions of slip-velocity intensity and a progression of wave generation with increasing frequency.

  12. Noninvasive Vascular Displacement Estimation for Relative Elastic Modulus Reconstruction in Transversal Imaging Planes

    PubMed Central

    Hansen, Hendrik H.G.; Richards, Michael S.; Doyley, Marvin M.; de Korte, Chris L.

    2013-01-01

    Atherosclerotic plaque rupture can initiate stroke or myocardial infarction. Lipid-rich plaques with thin fibrous caps have a higher risk to rupture than fibrotic plaques. Elastic moduli differ for lipid-rich and fibrous tissue and can be reconstructed using tissue displacements estimated from intravascular ultrasound radiofrequency (RF) data acquisitions. This study investigated if modulus reconstruction is possible for noninvasive RF acquisitions of vessels in transverse imaging planes using an iterative 2D cross-correlation based displacement estimation algorithm. Furthermore, since it is known that displacements can be improved by compounding of displacements estimated at various beam steering angles, we compared the performance of the modulus reconstruction with and without compounding. For the comparison, simulated and experimental RF data were generated of various vessel-mimicking phantoms. Reconstruction errors were less than 10%, which seems adequate for distinguishing lipid-rich from fibrous tissue. Compounding outperformed single-angle reconstruction: the interquartile range of the reconstructed moduli for the various homogeneous phantom layers was approximately two times smaller. Additionally, the estimated lateral displacements were a factor of 2–3 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding. PMID:23478602

  13. Dynamic ruptures in recent models of earthquake faults

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Yehuda

    2001-09-01

    We discuss several problems of dynamic rupture relevant to mechanics of earthquake faults, material sciences, and physics of spatially extended dissipative systems. The problems include dynamic rupture along an interface separating different elastic solids, dynamic rupture on a planar surface governed by strongly velocity-weakening friction, and elastodynamic calculations of long deformation history on a smooth fault in an elastic continuum. These separate problems share a number of methodological and conceptual issues that form recurring themes in the paper. An important methodological issue for computational schemes is dependency of numerical results on the used grid size. This arises inevitably in computer simulations when the assumed constitutive laws do not include a length scale (e.g., of shear or extensional displacement) over which material properties evolve. Such simulations do not have a stable underlying solution, to which they may converge with sufficient grid refinement. However, they may provide rough approximations—lacking at present a rigorous foundation—to the behavior of systems containing elements of discreteness (associated with abrupt fluctuations) at scales relevant to observations of interest. Related important conceptual issues are connections between, or when appropriate separation of, small scale phenomena (e.g., nucleation of rupture, processes at rupture front) and large scale features of the response (e.g., overall space-time dimensions of rupture, statistics of many events). Additional recurring conceptual topics are crack vs. pulse modes of dynamic rupture, the stress under which earthquake faults slip, and the origin of spatio-temporal complexities of earthquakes. These seemingly different issues probably have one or more common origins. Dynamic rupture on an interface between different solids, strongly velocity-weakening friction on a homogeneous fault, and strong fault zone heterogeneities can all produce narrow self-healing slip pulses with low dynamic stress (and low associated frictional heat) during the active part of slip. Strong fault heterogeneities probably play the dominant role in producing the observed earthquake complexities. Improved understanding of the discussed problems will require establishing connections between discrete and continuum descriptions of mechanical failure processes, generalization of current models to realistic three-dimensional dynamic models, and high-resolution laboratory and in-situ observations over broad scales of space and time. These challenging problems provide by their subject matter and involved great difficulties important targets for multi-disciplinary research by engineers, earth scientists, and physicists.

  14. BWH emergency radiology-surgical correlation: intraperitoneal urinary bladder rupture.

    PubMed

    Landman, Wendy; Khurana, Bharti; Briggs, Alexandra; Fairweather, Mark; Cooper, Zara; Riviello, Robert; Sodickson, Aaron D

    2015-12-01

    We describe the radiological and intraoperative correlation of two cases of intraperitoneal bladder rupture: a 23-year-old man involved in a high-speed motor vehicle collision and a 49-year-old man with hematuria and abdominal pain after a night of heavy alcohol ingestion. Both patients underwent urgent exploratory laparotomies and repair of their bladder injuries. The purpose of this article is to emphasize the importance of understanding the different etiologies of bladder rupture and recognizing the imaging findings on computed tomography (CT) and CT cystography to help guide the surgeons in the patient's management. PMID:25998022

  15. Intra-Aortic Balloon Pump Rupture and Entrapment

    PubMed Central

    Jahollari, Artan; Sarac, Atilla; Ozal, Ertugrul

    2014-01-01

    Intra-aortic balloon pump is used frequently to support a failing myocardium in cardiac patients. Due to the invasive nature of this device, usage is accompanied by consistent risk of complications. Balloon rupture, although it occurs rarely, may lead to entrapment if diagnosis delays. A 78-year male who underwent cardiac surgery experienced balloon rupture and entrapment in the right femoral artery during the postoperative follow-up. Surgical extraction under local anesthesia was performed and the patient had an uneventful course. Fast and gentle solution of the problem is necessary to prevent further morbidity or mortality related to a retained balloon catheter in these delicate patients. PMID:24707435

  16. Intra-aortic balloon pump rupture and entrapment.

    PubMed

    Jahollari, Artan; Sarac, Atilla; Ozal, Ertugrul

    2014-01-01

    Intra-aortic balloon pump is used frequently to support a failing myocardium in cardiac patients. Due to the invasive nature of this device, usage is accompanied by consistent risk of complications. Balloon rupture, although it occurs rarely, may lead to entrapment if diagnosis delays. A 78-year male who underwent cardiac surgery experienced balloon rupture and entrapment in the right femoral artery during the postoperative follow-up. Surgical extraction under local anesthesia was performed and the patient had an uneventful course. Fast and gentle solution of the problem is necessary to prevent further morbidity or mortality related to a retained balloon catheter in these delicate patients. PMID:24707435

  17. Spontaneous Liver Rupture After Treatment With Drug-Eluting Beads

    SciTech Connect

    Ritter, C. O.; Wartenberg, M.; Mottok, A.; Steger, U.; Goltz, J. P.; Hahn, D.; Kickuth, R.

    2012-02-15

    Spontaneous rupture of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is a rare and life-threatening complication. Pathophysiologic mechanisms are not yet fully known; it is suggested that rupture is preceded by reactive tissue edema and intratumerous bleeding, leading to a rapid expansion of tumour mass with risk of extrahepatic bleeding in the case of subcapsular localisation. This case report discusses a sudden, unexpected lethal complication in a 74 year-old male patient treated with TACE using DC Bead loaded with doxorubicin (DEBDOX) in a progressive multifocal HCC.

  18. Frontal lobe cerebral aneurysm rupture presenting as psychosis.

    PubMed Central

    Hall, D P; Young, S A

    1992-01-01

    A 23 year old male with acute onset of blunted affect, looseness of associations and auditory hallucinations presented to a tertiary care hospital 10 days after development of symptoms. Before transfer, the patient received a diagnosis of schizophreniform disorder and treatment with haloperidol was started which resulted in moderate improvement. Examination led to detection of a ruptured cerebral aneurysm in the left frontal lobe. Evacuation of the haematoma and repair of the aneurysm resulted in nearly complete resolution of symptoms. The rare incidence of acute aneurysm rupture, presenting in the case described, demonstrates the importance of a complete neurological examination in the evaluation of acute mental status changes. Images PMID:1479403

  19. Rapid Mapping of Surface Rupture from the South Napa Earthquake

    NASA Astrophysics Data System (ADS)

    Trexler, C. C.; Morelan, A. E., III; Oskin, M. E.

    2014-12-01

    Rapid documentation (<1 day) of co-seismic surface rupture location and slip is essential for scientific and emergency response. We demonstrate how social media (text messaging and Twitter) and the emerging 3D data collection technique known as Structure from Motion (SfM), used in conjunction with traditional field reconnaissance, enabled us to rapidly locate and document surface ruptures from the Mw 6.0 South Napa earthquake. On the morning of the event, our field team used information available on social media to identify locations with potential surface rupture. Preliminary observations of surface rupture (measurements and geo-tagged photographs) were texted to the office-based team member who created digital maps of the rupture trace and shared them online via Twitter in near-real time. We documented many ephemeral features (such as offset roads, curbs, and driveways) along the rupture trace within 12 hours of the event, before these features were destroyed by road and infrastructure repair. We were able to return to most sites again within several days, allowing us to document continuing slip and create time-series datasets of offset features. After the collection and re-collection of data at selected sites, we made detailed measurements remotely using 3D models constructed with SfM. The ability to quantitatively project features into the fault plane using these models allows for accurate measurements of small features often difficult to observe and quantify in the field. Traditionally, even preliminary maps of rupture extent and offset magnitudes are not available for several days after an event because office-based processing and compilation is required. Because we were able to compile our data in real time, we distributed our results while they were still valuable for ongoing scientific response. Our work helped other science teams efficiently target fieldwork and instrument deployment; for example, one geodetic survey team used our surface rupture map to adjust their field deployment plans in an effort to capture rapidly-decaying postseismic movement. With social media and rapid, inexpensive data collection methods like SfM in mind, scientific response to future events has the potential to be more efficient and coordinated than ever before.

  20. Left ventricular rupture postmitral valve replacement: surviving a catastrophe.

    PubMed

    Bisoyi, Samarjit; Mohanty, Jitendu; Mohapatra, Raghunath; Nayak, Debashish

    2015-01-01

    One of the dreaded mechanical complications of mitral valve replacement (MVR) is rupture of the left ventricle (LV). This report describes the early diagnosis and successful repair of rupture of posterior wall of LV in an elderly patient who underwent MVR. We have discussed the risk factors and perioperative issues implicated in such complication. The anesthesiologist as an intra-operative echocardiographer can aid in identifying the patient at risk. Though important surgical steps are necessary to prevent the complication; nonetheless, the anesthesiologist needs to take key measures in the perioperative period. PMID:25566717

  1. Shock-Wave Theory for Rupture of Rubber

    NASA Astrophysics Data System (ADS)

    Marder, M.

    2005-01-01

    This Letter presents a theory for the rupture of rubber. Unlike conventional cracks, ruptures in rubber travel faster than the speed of sound and consist of two oblique shocks that meet at a point. Physical features of rubber needed for this phenomenon include Kelvin dissipation and an increase of toughness as rubber retracts. There are three levels of theoretical description: an approximate continuum theory, an exact analytical solution of a slightly simplified discrete problem, and numerical solution of realistic and fully nonlinear equations of motion.

  2. Spleen rupture due to primary angiosarcoma: a case report.

    PubMed

    Koutelidakis, Ioannis M; Tsiaousis, Panagiotis Z; Papaziogas, Basilios Th; Patsas, Aristeides G; Atmatzidis, Stefanos K; Atmatzidis, Konstantinos S

    2007-01-01

    A case of a 79-year-old female with rupture of the spleen due to primary angiosarcoma is presented. Symptoms were non-specific. Diagnosis was based on histology postoperatively. Primary angiosarcoma of the spleen is a very rare and aggressive neoplasm with a high metastatic rate and almost uniformly fatal. Due to small number of reported cases, there are no guidelines concerning adjuvant or palliative treatment or any beneficial protocols of chemotherapy or radiotherapy up to date. Splenectomy prior to rupture seems to have a positive impact on long-term survival. PMID:19016352

  3. Spontaneous rupture of non-parasitic hepatic cyst.

    PubMed

    Poggi, G; Gatti, C; Delmonte, A; Teragni, C; Bernardo, G

    2006-01-01

    Intrahepatic cysts are generally classified as congenital, traumatic, infectious or neoplastic. Non-parasitic hepatic cysts (NPHCs) include simple cysts and adult polycystic liver disease in which the liver is diffusely occupied by cysts. NPHCs usually reach a large size before causing symptoms, unless a complication such as rupture, bleeding, infection, obstructive jaundice or neoplastic transformation occurs. We report the case of a 67-year-old man with spontaneous rupture of simple liver cyst. The clinical pictures and the unusual ultrasound features of this rare condition are discussed. PMID:16409436

  4. Quantum metrology for the Ising Hamiltonian with transverse magnetic field

    NASA Astrophysics Data System (ADS)

    Skotiniotis, Michael; Sekatski, Pavel; Dür, Wolfgang

    2015-07-01

    We consider quantum metrology for unitary evolutions generated by parameter-dependent Hamiltonians. We focus on the unitary evolutions generated by the Ising Hamiltonian that describes the dynamics of a one-dimensional chain of spins with nearest-neighbour interactions and in the presence of a global, transverse, magnetic field. We analytically solve the problem and show that the precision with which one can estimate the magnetic field (interaction strength) given one knows the interaction strength (magnetic field) scales at the Heisenberg limit, and can be achieved by a linear superposition of the vacuum and N free fermion states. In addition, we show that Greenberger-Horne-Zeilinger-type states exhibit Heisenberg scaling in precision throughout the entire regime of parameters. Moreover, we numerically observe that the optimal precision using a product input state scales at the standard quantum limit.

  5. Transverse Force on Quarks in DIS

    E-print Network

    Matthias Burkardt

    2013-11-16

    The interaction dependent part of the $x^2$-moment of the twist-3 polarized parton distribution $g_2(x)$ is related to the transverse force acting on the active quark in deep-inelastic scattering off a transversely polarized nucleon immediately after it has absorbed the virtual photon. Similarly, the $x^2$-moment of the chirally odd twist-3 unpolarized parton distribution $e(x)$ can be related to the transverse force experienced by a transversely polarized quark ejected from a transversely polarized nucleon.

  6. Electron Ion Collider transverse spin physics

    E-print Network

    Alexei Prokudin

    2010-11-26

    Electron Ion Collider is a future high energy facility for studies of the structure of the nucleon. Three-dimensional parton structure is one of the main goals of EIC. In momentum space Transverse Momentum Dependent Distributions (TMDs) are the key ingredients to map such a structure. At leading twist spin structure of spin-1/2 hadron can be described by 8 TMDs. Experimentally these functions can be studied in polarised SIDIS experiments. We discuss Sivers distribution function that describes distribution of unpolarised quarks in a transversely polarised nucleon and transversity that measures distribution of transversely polarised quarks in a transversely polarised nucleon.

  7. High strength alloys

    DOEpatents

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  8. High strength alloys

    DOEpatents

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  9. Spin resonance strength calculations

    SciTech Connect

    Courant,E.D.

    2008-10-06

    In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

  10. Modeling Dynamic Source Rupture with Slip Reactivation and Near-Source Ground Motion of the 2012 Mw 9.0 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Dalguer, L. A.; Ampuero, J. P.

    2012-12-01

    The compilation of seismological, geodetic, bathymetric and tsunami observations as well as source inversion and back-projection studies of the 2011 Mw 9.0 Tohoku earthquake show that this earthquake is mainly characterized by three main features: 1) unusual large slip over 50m; 2) complex rupture patterns with multiple rupture fronts and slip reactivation; 3) distinct depth dependent frequency radiation patterns, in which the shallower part of the fault dominate the low frequency radiation and the deep part dominates the high frequency radiation. Earthquakes with extremely large slip can result from fault melting, pressurization, lubrication or other thermal weakening mechanisms that reduces further the frictional strength to lower levels. Kanamori and Heaton (2000) proposed a friction model in which frictional strength drops initially to certain value, but then at large slips there is a second drop of the frictional strength. We use Kanamori and Heaton's friction model to investigate the features mentioned above in a simple spontaneous dynamic rupture asperity model governed by slip weakening friction. The model is composed of large asperity patches of radius between 30 to 50 km in the intermediate and shallower part, and small patches of asperities at the bottom of the fault to account for the strong high frequency radiation. The very shallow part of the fault is considered as a stable zone that operates during rupture with an enhanced energy absorption mechanism. We model this zone by assuming negative stress drop and large critical slip distance. In our first attempt, we assume a planar fault using a 3D finite difference code, in which we reproduced the main three features mentioned above: rupture initiates propagating toward east and north. After around 40 sec of rupture initiation, the second drop of the frictional strength in the main asperity produces strong slip reactivation capable to break the free-surface with large slip. This slip reactivation also excites the small asperity patches producing burst of high frequency radiation, which in turn produces a third rupture of an asperity propagating southward. Our simulations show that the slip reactivation plays a fundamental role to produce multi type of ruptures, to break the free-surface and to reach a magnitude Mw9.0. In the second part, we evaluate the proposed model described above in a more realistic fault setting that consists of a non-planar fault aligned along the subduction zone. For this purpose, we use the unstructured 3D spectral element open source code SPECFEM3D-SESAME that allows to model geometrically complex fault systems. The effect of the fault geometry on the rupture process and its interaction with the free-surface are evaluated. With this proposed model we aim to reproduce the strong ground motion patterns observed in the Japanese K-NET and KiK-net stations.

  11. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    E-print Network

    Dunham, Eric M.

    Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex simulations of earthquake ruptures and the resulting strong ground motion form a crucial component idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across

  12. Rupture termination at restraining bends: The last great earthquake on the Altyn Tagh Fault

    NASA Astrophysics Data System (ADS)

    Elliott, Austin J.; Oskin, Michael E.; Liu-Zeng, Jing; Shao, Yanxiu

    2015-04-01

    Strike-slip rupture propagation falters where changes in fault strike increase Coulomb failure stress. Numerical models of this phenomenon offer predictions of rupture extent based on bend geometry, but have not been verified with field data. To test model predictions of rupture barriers, we examine rupture extent along a section of the sinistral Altyn Tagh Fault punctuated by three major double bends. We measure 3-8 m offsets and map >95 km of continuous scarps that define the most recent surface rupture. We document the eastern terminus of this rupture within the Aksay bend, where an undeformed Pleistocene alluvial fan we mapped and dated overlaps the fault. We conclude, based on this geomorphologic evidence, that multiple Holocene ruptures have stopped in the Aksay bend. Our field data validate model predictions of rupture termination at a >18° restraining bend and support use of geometric parameters to define expected earthquake sizes in seismic hazard models.

  13. 14 CFR 25.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Protection of oxygen equipment from rupture. 25.1453 Section...Miscellaneous Equipment § 25.1453 Protection of oxygen equipment from rupture. Oxygen pressure tanks, and lines between tanks and...

  14. 14 CFR 25.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Protection of oxygen equipment from rupture. 25.1453 Section...Miscellaneous Equipment § 25.1453 Protection of oxygen equipment from rupture. Oxygen pressure tanks, and lines between tanks and...

  15. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 false Protection of oxygen equipment from rupture. 23.1453 ...Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient...

  16. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Protection of oxygen equipment from rupture. 23.1453 ...Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient...

  17. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 false Protection of oxygen equipment from rupture. 23.1453 ...Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient...

  18. 14 CFR 25.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Protection of oxygen equipment from rupture. 25.1453 Section...Miscellaneous Equipment § 25.1453 Protection of oxygen equipment from rupture. Oxygen pressure tanks, and lines between tanks and...

  19. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 false Protection of oxygen equipment from rupture. 23.1453 ...Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient...

  20. 14 CFR 25.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Protection of oxygen equipment from rupture. 25.1453 Section...Miscellaneous Equipment § 25.1453 Protection of oxygen equipment from rupture. Oxygen pressure tanks, and lines between tanks and...

  1. 14 CFR 23.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Protection of oxygen equipment from rupture. 23.1453 ...Equipment § 23.1453 Protection of oxygen equipment from rupture. (a) Each element of the oxygen system must have sufficient...

  2. 14 CFR 25.1453 - Protection of oxygen equipment from rupture.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Protection of oxygen equipment from rupture. 25.1453 Section...Miscellaneous Equipment § 25.1453 Protection of oxygen equipment from rupture. Oxygen pressure tanks, and lines between tanks and...

  3. A Transversely Isotropic Thermoelastic Theory

    NASA Technical Reports Server (NTRS)

    Arnold, S. M.

    1989-01-01

    A continuum theory is presented for representing the thermoelastic behavior of composites that can be idealized as transversely isotropic. This theory is consistent with anisotropic viscoplastic theories being developed presently at NASA Lewis Research Center. A multiaxial statement of the theory is presented, as well as plane stress and plane strain reductions. Experimental determination of the required material parameters and their theoretical constraints are discussed. Simple homogeneously stressed elements are examined to illustrate the effect of fiber orientation on the resulting strain distribution. Finally, the multiaxial stress-strain relations are expressed in matrix form to simplify and accelerate implementation of the theory into structural analysis codes.

  4. Effect of Hf-Rich Particles on the Creep Life of a High-strength Nial Single Crystal Alloy

    NASA Technical Reports Server (NTRS)

    Garg, A.; Raj, S. V.; Darolia, R.

    1995-01-01

    Additions of small amounts of Hf and Si to NiAl single crystals significantly improve their high-temperature strength and creep properties. However, if large Hf-rich dendritic particles formed during casting of the alloyed single crystals are not dissolved completely during homogenization heat treatment, a large variation in creep rupture life can occur. This behavior, observed in five samples of a Hf containing NiAl single crystal alloy tested at 1144 K under an initial stress of 241.4 MPa, is described in detail highlighting the role of interdendritic Hf-rich particles in limiting creep rupture life.

  5. Strong transverse coupling in the Tevatron

    SciTech Connect

    Annala, G; Carson, J; Edwards, Don; Gelfand, N; Harding, D; Johnson, T; Johnstone, J; Martens, M; Sen, T; Syphers, Mike

    2003-03-01

    The Tevatron was designed with an extensive set of correction and adjustment magnets built into the spool pieces in recognition of the circumstance that a superconducting synchrotron was not as easy to modify as its conventional forebearers. Recently, concern has mounted at the high excitation of the skew quadrupole correctors. The purpose of this note is to account for this situation. When slow extraction was attempted from the Main Ring in the summer of 1970 horizontal-vertical coupling prevented adequate transverse oscillation growth for efficient slow spill. This situation was corrected by an 8 mrad roll of each of twelve equi-spaced quadrupoles [1]. In order to avoid a repetition of this problem in the Tevatron, an extremely strong skew quadrupole circuit was built in at the outset. When the Tevatron was commissioned only 4$ of the capability of this circuit was required. Now, 20 years later, the excitation of this skew quadrupole circuit is approximately 60%. Other skew quadrupole correctors were installed in the neighborhood of the long straight sections, and for a variety of reasons the number of elements in the strong circuit was reduced from 48 to 42. These are relatively minor changes in the present context. Recall that in the normal Tevatron tuning process the skew quad circuits are adjusted to minimize the difference between the horizontal and vertical tunes to the level of {Delta}{nu}{sub min} {approx} 0.003. Normally the horizontal-vertical coupling is not observed directly by orbit measurements during this procedure. it was recognized that the strength of the skew quadrupole settings would imply an uncorrected minimum tune difference of 0.2 units. Clearly, with the skew quad circuit turned off the coupling of the orbital motion should be easily observable. In the following sections, the authors describe the recent Tevatron studies that exhibit the transverse coupling and the analyses that link these observations to the long term development of a skew quadrupole coefficient in the Tevatron dipoles. In brief, their conclusion is that a{sub 1} at the level of one of the traditional units will account for the coupling and is consistent with physical examination of a selection of dipoles in the tunnel.

  6. Improved Data Set for the Frequency of Gaps and Steps in Ground Ruptures

    NASA Astrophysics Data System (ADS)

    Biasi, G. P.; Wesnousky, S. G.; Morelan, A. E., III

    2014-12-01

    Observations of actual ground ruptures from moderate and large earthquakes show a wide range of behaviors, including fault-to-fault jumps, branching topologies, and rupture traces with multi-kilometer gaps between them. Seismic hazard assessments have responded to these observations by including increasingly sophisticated scenarios of possible ruptures in their earthquake rate forecasts. The largest of these to date has been the Uniform California Earthquake Forecast 3 (UCERF3), which explicitly included ruptures with fault-to-fault jumps in its rupture rate estimates. High-level site-specific seismic source characterizations such as for the Diablo Canyon Power Plant have also begun including complicated rupture geometries. Systematic collection of observations from ground rupturing earthquakes provide one way to evaluate these seismic source models. We have expanded an initial collection by Wesnousky (2008) with events post-dating that collection and events for which new information is available. New events increase the strike-slip and normal event set by 50% and reverse events by 35%. New data allow us to revise previous estimates for strike-slip rupture of the probability that a step of 1 km or more in width will arrest rupture. Observationally, 65% of strike-slip ruptures include at least one step of 1 km or greater. The number of steps through which ruptures are observed to rupture through can be modeled by a geometric distribution in which steps are crossed about 59% of the time. Steps are slightly more effective at arresting rupture in normal and reverse faulting cases, being crossed 56% and 50%, respectively. New events were also systematically examined for gaps in the mapped rupture trace. We find gaps of 1 km or more in about half of the ruptures of the new event set. These empirical data will compliment new research into rupture propagation across gaps, exemplified by the 2010 El Mayor Cucapah earthquake, which included a gap measured variously at 7 or 15 km in length.

  7. A New Surgical Repair Technique for Ischemic Total Papillary Muscle Rupture.

    PubMed

    Lee, Sung Kwang; Heo, Woon; Min, Ho-Ki; Kang, Do Kyun; Jun, Hee Jae; Hwang, Youn-Ho

    2015-11-01

    Papillary muscle (PM) rupture is an emergency surgical condition that may occur after acute myocardial infarction. In patients with compete rupture of the PM, mitral valve replacement is preferred or recommended generally because of unstable vital signs or technical difficulties with successful repair, as compared with patients with partial PM rupture. This case report describes the successful repair of a complete anterolateral PM rupture by using the single PM formation technique with subsequent ring annuloplasty. PMID:26522535

  8. High strength composites evaluation

    SciTech Connect

    Marten, S.M.

    1992-02-01

    A high-strength, thick-section, graphite/epoxy composite was identified. The purpose of this development effort was to evaluate candidate materials and provide LANL with engineering properties. Eight candidate materials (Samples 1000, 1100, 1200, 1300, 1400, 1500, 1600, and 1700) were chosen for evaluation. The Sample 1700 thermoplastic material was the strongest overall.

  9. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    NASA Technical Reports Server (NTRS)

    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.

  10. Influence of plastic deformation on bimaterial fault rupture directivity

    E-print Network

    Dmowska, Renata

    Influence of plastic deformation on bimaterial fault rupture directivity Nora DeDontney,1 Elizabeth of the role of the stress state on the distribution of plastic deformation and the direction of preferred in determining the location of plastic deformation. For different orientations, plastic deformation can

  11. Double Passive Cavitation Detection of OptisonTM Shell Rupture

    E-print Network

    Illinois at Urbana-Champaign, University of

    of ultrasonic excitation parameters (driving frequency, pulse duration, and peak rarefactional pressure transducer functioning in the pulse-echo mode. Post-excitation signals were used to detect rupture thresholds. By allowing acquisition of the signals received by the insonifying transducer (pulse-echo during

  12. Mechanics of shear rupture applied to earthquake zones

    NASA Technical Reports Server (NTRS)

    Li, Victor C.

    1986-01-01

    The mechanics of shear slippage and rupture in rock masses are reviewed. The essential ideas in fracture mechanics are summarized emphasizing the interpretation and relation among the fracture parameters in shear cracks. The slip-weakening model is described. The general formulation of the problem of nonuniform slip distribution in a continuum is covered.

  13. The Rupture and Repair of Cooperation in Borderline

    E-print Network

    Zeki, Semir

    The Rupture and Repair of Cooperation in Borderline Personality Disorder Brooks King-Casas,1 individuals afflicted with borderline personality disorder (BPD) to play a multiround economic exchange game group of individuals diagnosed with borderline per- sonality disorder (BPD), a psychiatric disorder

  14. Rupture Loop Annex (RLA) ion exchange vault entry and characterization

    SciTech Connect

    Ham, J.E.

    1996-01-04

    This engineering report documents the entry and characterization of the Rupture Loop Annex Ion Exchange (RLAIX) Vault located near the 309 Building`s Plutonium Recycle Test Reactor (PRTR). Twelve ion exchange columns were found in the vault. Some of which contained transuranics, Cs 137, and Co 60. The characterization information is necessary for future vault cleanout and column disposal.

  15. Depth-varying rupture properties of subduction zone megathrust faults

    E-print Network

    Cerveny, Vlastislav

    ­45 km in subduction zones where relatively young oceanic lithosphere is being underthrust with shallowDepth-varying rupture properties of subduction zone megathrust faults Thorne Lay,1 Hiroo Kanamori,2] Subduction zone plate boundary megathrust faults accommodate relative plate motions with spatially varying

  16. Prediction of Cerebral Aneurysm Rupture using Hemodynamic, Morphologic and Clinical

    E-print Network

    Riera, Jesús Bisbal

    Prediction of Cerebral Aneurysm Rupture using Hemodynamic, Morphologic and Clinical Features¸cats (ICREA), Barcelona, Spain jesus.bisbal@upf.edu Abstract. Cerebral aneurysms pose a major clinical threat of the patient and characteristics of the aneurysm. The dataset used included 157 cases, with 294 features each

  17. "The Little Gray Book": Pedagogy, Discourse and Rupture in 1937

    ERIC Educational Resources Information Center

    Milewski, Patrice

    2008-01-01

    In 1937, the Ministry of Education in Ontario published a document entitled "Programme of Studies for Grades 1 to VI of Public and Separate Schools" that became known amongst teachers as the "little gray book". The curriculum and pedagogy in the document enunciated a rupture or mutation in pedagogical discourse that broke with previously existing…

  18. On the theory of the rupture of black films

    NASA Astrophysics Data System (ADS)

    Derjaguin, B. V.; Prokhorov, A. V.

    1994-04-01

    The present work covers the solution of a problem on the fluctuation rupture of black films [Derjaguin, B.V., and Gutop, Yu. V., Kolloid. zh.24, 431 (1962); Dokl. AN SSSR153, 859 (1963); “Research in Surface Forces,” Vol. 2, p. 36. Consultants Bureau, New York, 1966], which is interpreted as a two-dimensional analog of the homogeneous boiling of fluid. Such a two-dimensional mechanism of rupture must be realized first of all for secondary black and lipid films. Using the solution of the stationary Kramers-Zeldovich equation as the basis, we have derived a general expression for the probability of the isothermal rupture of a stretched film of the given area per unit time. The use of Gibbs Grand Ensemble [Derjaguin, B.V., Zh. eksp. teor. fis.65, 2261 (1973); J. Chem. Phys.61, 3665 (1974)] enabled us to calculate accurately the pre-exponential factor in that expression. Criteria of the applicability of the results obtained have been determined. A possibility is discussed for applying the abrupt dependence of the rupture probability of a film on its linear tension, to the accurate measurement of the latter.

  19. Axial creep-rupture time of boron-aluminum composites

    SciTech Connect

    Goda, Koichi; Hamada, Jun`ichi

    1995-11-01

    Axial creep tests of a 10vol% boron-aluminum hotpressed monolayer composite were carried out under several constant loads at 300 C in air. The composite behaved with slight primary creep, but did not show appreciable secondary creep. Several specimens encountered a momentary increase of strain during the creep test which separated the creep curve into two regions, because of the individual fiber breaks in the composite. And then, almost all the specimens suddenly fractured without tertiary creep. From the viewpoint of reliability engineering the statistical properties of the creep-rupture time were investigated. The average creep-rupture time decreased with an increase in the applied stress, and the relatively large coefficient of variation was estimated in every case, being around 1,000%. However, these scatters were estimated to be smaller than the scatter of creep-rupture time in the boron fiber itself. That means, the reliability of the fiber`s creep-rupture time is improved by compositing with matrix material.

  20. Diagnosis of splenic rupture in malignant lymphoma using radionuclides

    SciTech Connect

    Wallace, J.C.

    1985-01-01

    The case of a 59-year-old woman with malignant lymphoma who was investigated for fever and left upper quadrant abdominal pain is presented. A combined spleen/lung scan showed marked medial displacement of an enlarged spleen and a gallium scan showed increased splenic uptake consistent with lymphomatous infiltration. The diagnosis of prior splenic rupture with subphrenic hematoma was confirmed at laparotomy.

  1. Correlation of earthquake source parameters inferred from dynamic rupture simulations

    E-print Network

    Archuleta, Ralph

    authors. This database contains ruptures computed using different models of initial stress, peak stress of the physics of the earthquake process or at the very least, a reasonable approximation to the physics. Two the initial state of stress is given together with a friction law that describes how the shear stress evolves

  2. Preterm Delivery in the Setting of Left Calyceal Rupture

    PubMed Central

    Hanson, Brent; Tabbarah, Rami

    2015-01-01

    Spontaneous rupture of the renal collecting system is a rare but serious complication of pregnancy. We report a case of nontraumatic left renal calyceal rupture in a pregnancy which ultimately progressed to preterm delivery. A 29-year-old primigravida with a remote history of urolithiasis presented with left flank pain, suprapubic pain, and signs of preterm labor at 33 weeks of gestation. The patient was believed to have urolithiasis, although initial renal ultrasound failed to demonstrate definitive calculi. After a temporary improvement in flank pain with medication, the patient experienced acute worsening of her left flank pain. Urology was consulted and further imaging was obtained. Magnetic resonance imaging (MRI) was consistent with bilateral hydronephrosis and rupture of the left renal calyx. Given the patient's worsening pain in the setting of left calyceal rupture, the urology team planned for placement of a left ureteral stent. However, before the patient could receive her stent, she progressed to active labor and delivered a viable female infant vaginally. Following delivery, the patient's flank pain resolved rapidly and spontaneously, so no surgical intervention was performed. A summary of the literature and the details of this specific clinical situation are provided. PMID:26483981

  3. Rupture of a left internal mammary artery during cardiopulmonary resuscitation

    PubMed Central

    Metting, Austin; Curtis, Brydan; Mixon, Timothy

    2016-01-01

    We present a rare case of a left internal mammary artery rupture during cardiopulmonary resuscitation (CPR). This case demonstrates that intrinsic cardiac/vascular injuries can occur even with manual CPR, and each patient should be monitored closely, considering the very subtle signs that can clue the physicians into the diagnosis. PMID:26722182

  4. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    PubMed Central

    Cetinkaya, Engin; Aydin, Canan Gonen; Akman, Yunus Emre; Gul, Murat; Arikan, Yavuz; Aycan, Osman Emre; Kabukcuoglu, Yavuz Selim

    2015-01-01

    Introduction Quadriceps tendon injuries are rare. There is a limited number of studies in the literature, reporting partial quadriceps tendon ruptures. We did not find any study reporting an isolated vastus intermedius tendon injury in the literature. Presentation of case A 22 years old professional rugby player with the complaints of pain in the right lower limb, decreased range of motion in right knee and a mass in the mid-anterior of the right thigh applied following an overloading on his hyperflexed knee during a rugby match. T2 sequence magnetic resonance images revealed discontinuity in the vastus intermedius tendon and intramuscular hematoma. The patient has been conservatively treated. Discussion Quadriceps tendon ruptures generally occur after the 4th decade in the presence of degenerative changes. Our case is a young professional rugby player. Isolated vastus intermedius tendon rupture is unusual. Conservative treatment is performed as the intermedius tendon is in the deepest layer of the quadriceps muscle. Conclusion We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy. PMID:26298093

  5. Tsunami early warning using earthquake rupture duration Anthony Lomax1

    E-print Network

    Rawlinson, Nick

    Tsunami early warning using earthquake rupture duration Anthony Lomax1 and Alberto Michelini2] Effective tsunami early warning for coastlines near a tsunamigenic earthquake requires notification within 5, greater than about 50 s. Here we show that T0 gives more information on tsunami importance than moment

  6. Theory of time-dependent rupture in the Earth

    NASA Technical Reports Server (NTRS)

    Das, S.; Scholz, C. H.

    1980-01-01

    Fracture mechanics is used to develop a theory of earthquake mechanism which includes the phenomenon of subcritical crack growth. The following phenomena are predicted: slow earthquakes, multiple events, delayed multiple events (doublets), postseismic rupture growth and afterslip, foreshocks, and aftershocks. The theory predicts a nucleation stage prior to an earthquake, and suggests a physical mechanism by which one earthquake may 'trigger' another.

  7. Stretching and Rupture of Suspension Bridges, of the Fluid Variety

    NASA Astrophysics Data System (ADS)

    Connington, Kevin; Miskin, Mark; Lee, Taehun; Shattuck, Mark; Morris, Jeffrey; Jaeger, Heinrich

    2013-11-01

    A ``suspension bridge'' is similar to a liquid bridge but contains solid particles suspended in the liquid. In this work, experiments and numerical simulations are performed to examine the dynamics of the stretching of a suspension bridge, and the eventual rupture. The experiments are performed using a suspension density matched with the surrounding immiscible liquid to minimize gravitational effects; the simulations are performed using a multi-component lattice-Boltzmann(LB) method coupled with an established method for LB simulation of suspended solids. The focus is on particle rearrangements and rupture dynamics, as well as the force required to stretch the bridge, with comparisons made between the case of a suspension bridge and simple liquid bridge. It is found that even under dilute particle loading, the rupture dynamics are significantly altered by the influence of particles. Under concentrated conditions, the rearrangements of the particles are associated with significant distortion of the interface, and a simpler simulation tool which balances particle interactions with the capillary forces from the boundary appears to capture salient features of the dynamics. The ultimate rupture dynamics are compared to the pinch-off behavior in drop formation from suspensions.

  8. Percutaneous and Endovascular Embolization of Ruptured Hepatic Artery Aneurysm

    SciTech Connect

    Little, Andrew F.; Lee, Wai Kit

    2002-06-15

    A 72-year-old woman presented with an intraperitoneal hemorrhage from a ruptured intrahepatic arteryaneurysm, with an associated pseudoaneurysm developing a high-flow arteriovenous fistula. Persistent coagulopathy and a median arcuate ligament stenosis of the celiac axis further complicated endovascular management. Aneurysm thrombosis required percutaneous embolization with coils, a removable core guidewire and polyvinyl alcohol particles.

  9. Spontaneous rupture of the liver in severe preeclampsia. Case report.

    PubMed

    Ghosh, T S; Kwawukume, E Y

    1993-01-01

    Uncontrolled haemorrhage is the most common cause of death after spontaneous rupture of the liver in pregnancy. This severe complication of pregnancy-induced hypertension is associated with a high rate of both maternal and fetal mortality, and aggressive therapy should be instituted including treatment of haemorrhagic shock, control of hepatic bleeding, and delivery. PMID:8312216

  10. [Spontaneous liver rupture in pregnancy-induced hypertension].

    PubMed

    Perucca, E; Cazenave, H; Gutiérrez, I; Barrera, C; Fuenzalida, J P

    1991-01-01

    Spontaneous rupture of liver during pregnancy is associated with a very high maternal mortality. This lesion is an unusual complication of the preeclampsia-eclampsia syndrome. We report the case of a 34 years old woman who suffered this complication; responding satisfactorily after conservative surgical treatment. PMID:1845200

  11. Ultrasound evaluation of a spontaneous plantar fascia rupture.

    PubMed

    Louwers, Michael J; Sabb, Brian; Pangilinan, Percival H

    2010-11-01

    Plantar fascia rupture is an occasional complication in patients with chronic plantar fasciitis or in patients with plantar fasciitis treated with steroid injection. Very few cases of spontaneous plantar fascia rupture have been reported in the literature (Herrick and Herrick, Am J Sports Med 1983;11:95; Lun et al, Clin J Sports Med 1999;9:48-9; Rolf et al, J Foot Ankle Surg 1997;36:112-4; Saxena and Fullem, Am J Sports Med 2004;32:662-5). Spontaneous medial plantar fascia rupture in a 37-yr-old man with no preceding symptoms or steroid injections was confirmed with diagnostic ultrasound, which revealed severe fasciitis at the calcaneal insertion with partial tearing. After conservative treatment, the patient returned to full activities. We discuss the anatomy, risk factors, examination findings, and treatment for this condition, as well as the unique benefits that ultrasound offers over magnetic resonance imaging. It is important to consider plantar fascia rupture in patients with hindfoot pain and medioplantar ecchymosis, particularly if an injury occurred during acceleration maneuvers. Ultrasound in these cases can be used to diagnose a plantar fascia tear quickly, accurately, and cost-effectively. PMID:20962604

  12. Anthrax toxin-induced rupture of artificial lipid bilayer membranes

    NASA Astrophysics Data System (ADS)

    Nablo, Brian J.; Panchal, Rekha G.; Bavari, Sina; Nguyen, Tam L.; Gussio, Rick; Ribot, Wil; Friedlander, Art; Chabot, Donald; Reiner, Joseph E.; Robertson, Joseph W. F.; Balijepalli, Arvind; Halverson, Kelly M.; Kasianowicz, John J.

    2013-08-01

    We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm.

  13. The Strength of Varying Tie Strength

    E-print Network

    Bruggeman, Jeroen

    2012-01-01

    "The Strength of Weak Ties" argument (Granovetter 1973) says that the most valuable information is best collected through bridging ties with other social circles than one's own, and that those ties tend to be weak. Aral and Van Alstyne (2011) added that to access complex information, actors need strong ties ("high bandwidth") instead. These insights I generalize by pointing at actors' interest to avoid spending large resources on low value information. Weak ties are well-suited for relatively simple information at low transmission and tie maintenance costs, whereas for complex information, the best outcomes are expected for those actors who vary their bandwidths along with the value of information accessed. To support my claim I use all patents in the USA (two million) over the period 1975-1999. I also show that in rationalized fields, such as technology, bandwidth correlates highly with the value of information, which provides support for using this proxy if value can't be measured directly. Finally, I show ...

  14. Transverse excitations in liquid metals

    NASA Astrophysics Data System (ADS)

    Hosokawa, S.; Munejiri, S.; Inui, M.; Kajihara, Y.; Pilgrim, W.-C.; Baron, A. Q. R.; Shimojo, F.; Hoshino, K.

    2013-02-01

    The transverse acoustic excitation modes were detected by inelastic x-ray scattering in liquid Ga, Cu and Fe in the Q range around 10 nm-1 using a third-generation synchrotron radiation facility, SPring-8, although these liquid metals are mostly described by a simple hard-sphere liquid. Ab initio molecular dynamics simulations clearly support this finding for liquid Ga. From the detailed analyses for the S(Q,?) spectra with good statistic qualities, the lifetime of less than 1 ps and the propagating length of less than 1 nm can be estimated for the transverse acoustic phonon modes, which correspond to the lifetime and size of cages formed instantaneously in these liquid metals. The microscopic Poisson's ratio estimated from the dynamic velocities of sound is 0.42 for liquid Ga and about -0.2 for liquid transition metals, indicating a rubber-like soft and extremely hard elastic properties of the cage clusters, respectively. The origin of these microscopic elastic properties is discussed in detail.

  15. Assessment of Aortic Aneurysm Rupture Risk Rafael Izbicki, Ann B. Lee and Ender A. Finol

    E-print Network

    Assessment of Aortic Aneurysm Rupture Risk Rafael Izbicki, Ann B. Lee and Ender A. Finol Carnegie Mellon University May 2011 Abstract The rupture of an abdominal aortic aneurysm (AAA) is associated, it is important to find good predictors for immediate risk of rupture. Clinically, the size of the aneurysm

  16. Similarity solutions for van der Waals rupture of a thin film on a solid substrate

    E-print Network

    Gardel, Margaret

    . INTRODUCTION Van der Waals forces can cause a thin liquid film on a solid substrate to rupture and form a dry. Van-der-Waals-driven film rupture is an important step in the collapse of a foam and in dropletSimilarity solutions for van der Waals rupture of a thin film on a solid substrate Wendy W. Zhang

  17. Earthquake Early Warning and the Physics of Earthquake Rupture Gilead Wurman

    E-print Network

    Allen, Richard M.

    Earthquake Early Warning and the Physics of Earthquake Rupture By Gilead Wurman 2010 #12; #12; 1 Abstract Earthquake Early Warning and the Physics of Earthquake Rupture of whether earthquake ruptures are self-similar, cascading failures, or whether their size is somehow

  18. Incorporating Micro-Mechanics Based Damage Models into Earthquake Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Bhat, H.; Rosakis, A.; Sammis, C. G.

    2012-12-01

    The micromechanical damage mechanics formulated by Ashby and Sammis, 1990 and generalized by Deshpande and Evans 2008 has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated new crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative. Incorporating this feature produces additional strain-rate sensitivity in the constitutive response. The model is also experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over a wide range of strain rates. Model parameters determined from quasi-static experiments were used to predict the failure strength at higher loading rates. Agreement with experimental results was excellent. After this verification step the constitutive law was incorporated into a Finite Element Code focused on simulating dynamic earthquake ruptures with specific focus on the ends of the fault (fault tip process zone) and the resulting strong ground motion radiation was studied.

  19. Ruptured pericardial perivascular epithelioid cell tumor (PEComa) leading to sudden death: an autopsy case report and review of the literature.

    PubMed

    Zhang, Lingxin; Carpenter, Danielle; Dehner, Louis P

    2016-01-01

    A 30-year-old man with past medical history of atrial fibrillation/flutter passed away after presenting with sudden-onset cardiac dysfunction. The postmortem examination revealed cardiac tamponade secondary to rupture of a 7.2-cm pericardial perivascular epithelioid cell tumor (PEComa). The tumor grossly appeared to arise from the transverse pericardial sinus and focally penetrated the epicardium of the right atrium. Microscopically, it was composed of predominately spindle cells with low nuclear grade, no pleomorphism, or readily apparent mitoses. Immunohistochemistry revealed cytoplasmic reactivity for HMB-45, desmin, and smooth muscle actin. Electron microscopic findings were characterized by melanosome-like structures intermixed with intermediate filaments and abundant stacked endoplasmic reticulum. The present case is unique among previously reported pericardial/myocardial PEComas as a first example resulting in unexpected cardiac tamponade and sudden cardiac death. PMID:26386746

  20. Anicteric gallbladder rupture in dogs: 5 cases (2007-2013).

    PubMed

    Guess, Sarah C; Harkin, Kenneth R; Biller, David S

    2015-12-15

    Objective-To describe clinical, laboratory, and surgical findings in dogs with confirmed gallbladder rupture and in which serum total bilirubin concentration was within reference limits. Design-Retrospective case series. Animals-5 dogs. Procedures-Medical records were searched to identify dogs with gallbladder rupture that underwent treatment at the Kansas State University Veterinary Health Center from November 2007 through November 2013. Dogs were included if they had undergone abdominal ultrasonography, serum total bilirubin concentration was ? 0.4 mg/dL, and abdominal exploratory surgery confirmed the presence of gallbladder upture. Results-An exploratory celotomy was performed in all dogs because of ultrasonographic findings of mild to marked abdominal effusion and either an unidentifiable gallbladder (n = 1 dog) or a distended gallbladder with a suspected gallbladder mucocele (4 dogs). Serum total bilirubin concentration was within reference limits (median, 0.2 mg/dL; range, 0.1 to 0.4 mg/dL; reference range, 0.1 to 0.4 mg/dL) in all dogs before surgery. In 1 dog, bile acids concentrations in serum and in peritoneal fluid were compared and the results (48 ?mol/L and 1,070 ?mol/L, respectively) were supportive of the diagnosis of gallbladder rupture. Conclusions and Clinical Relevance-Results indicated that even when serum total bilirubin concentration is within reference limits, gallbladder rupture should be considered in dogs with acute signs of abdominal pain when a mucocele is suspected on abdominal imaging and free abdominal fluid is present. Results suggested that a comparison of serum to peritoneal fluid bile acids concentrations may provide additional support for a diagnosis of gallbladder rupture. PMID:26642136

  1. Dynamic Rupture Benchmarking of the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    Pelties, C.; Gabriel, A.

    2012-12-01

    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

  2. Dynamic Rupture Benchmarking of the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    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

  3. Creep rupture testing of alloy 617 and A508/533 base metals and weldments.

    SciTech Connect

    Natesan, K.; Li, M.; Soppet, W.K.; Rink, D.L.

    2012-01-17

    The NGNP, which is an advanced HTGR concept with emphasis on both electricity and hydrogen production, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 750-1000 C. Alloy 617 is a prime candidate for VHTR structural components such as reactor internals, piping, and heat exchangers in view of its resistance to oxidation and elevated temperature strength. However, lack of adequate data on the performance of the alloy in welded condition prompted to initiate a creep test program at Argonne National Laboratory. In addition, Testing has been initiated to evaluate the creep rupture properties of the pressure vessel steel A508/533 in air and in helium environments. The program, which began in December 2009, was certified for quality assurance NQA-1 requirements during January and February 2010. Specimens were designed and fabricated during March and the tests were initiated in April 2010. During the past year, several creep tests were conducted in air on Alloy 617 base metal and weldment specimens at temperatures of 750, 850, and 950 C. Idaho National Laboratory, using gas tungsten arc welding method with Alloy 617 weld wire, fabricated the weldment specimens. Eight tests were conducted on Alloy 617 base metal specimens and nine were on Alloy 617 weldments. The creep rupture times for the base alloy and weldment tests were up to {approx}3900 and {approx}4500 h, respectively. The results showed that the creep rupture lives of weld specimens are much longer than those for the base alloy, when tested under identical test conditions. The test results also showed that the creep strain at fracture is in the range of 7-18% for weldment samples and were much lower than those for the base alloy, under similar test conditions. In general, the weldment specimens showed more of a flat or constant creep rate region than the base metal specimens. The base alloy and the weldment exhibited tertiary creep after 50-60% of the rupture life, irrespective of test temperature in the range of 750-950 C. The results showed that the stress dependence of the creep rate followed a power law for both base alloy and weldments. The data also showed that the stress exponent for creep is the same and one can infer that the same mechanism is operative in both base metal and weldments in the temperature range of the current study. SEM fractography analysis indicated that both base metal and weldment showed combined fracture modes consisting of dimple rupture and intergranular cracking. Intergranular cracking was more evident in the weldment specimens, which is consistent with the observation of lower creep ductility in the weldment than in the base metal.

  4. Does Earthquake Rupturing Initiate in Fluid-Overpressured Crust? - The Case for Scientific Drilling in NE Honshu

    NASA Astrophysics Data System (ADS)

    Sibson, R. H.

    2009-12-01

    Inland earthquakes in Japan arise from rupturing within an upper crustal seismogenic zone that is typically 10-20 km deep. Because such events may occur in close proximity to cities or critical facilities, giving rise to particularly intense ground motions, they contribute significantly to the aggregate seismic hazard. Since 2003, five strong crustal earthquakes (6.3 < M < 6.9) have ruptured steep reverse faults (dips > 45°) both west and east of the Ou Backbone Range hosting the volcanic front in NE Honshu. The earthquakes generally nucleated within the lower seismogenic zone at depths of 5 - 15 km. Several earlier events in the region (e.g. 1964 M7.5 Niigata earthquake) are of similar character. These steep reverse ruptures appear to be part of the ongoing compressional inversion of Miocene rift basins associated with arc-normal shortening that began at c. 3.5 Ma. Hazard from such compressional inversion earthquakes is difficult to assess because potential seismogenic faults (often with low net displacement) tend to be blanketed by post-rift deposition within sedimentary basins (e.g. the 2004 M6.6 Mid-Niigata and M6.6 Niigata-Chuetsu earthquake sequences). The compressional regime of NE Honshu is an optimal setting for ‘holding-in’ fluid overpressure. Frictional mechanics suggests that reactivation of inherited normal faults as steep reverse faults requires pore-fluid pressure elevated above hydrostatic to near-lithostatic pressures at the depth of rupture initiation. Oil-field drilling has shown that aqueous overpressures above hydrostatic exist at depths > 2-3 km in the Niigata sedimentary basin which has hosted several of the rupture sequences. In addition, local geophysical anomalies (high electrical conductivity, seismic low velocities, bright-spot S-wave reflectors, Vp/Vs) in NE Honshu point to heterogeneous fluid overpressuring in the vicinity of the active faults in the lower seismogenic zone. Whether or not earthquake ruptures initiate in fluid overpressured crust is important because cycling of fluid-pressure and fault frictional strength through fault-valve action (postseismic discharge along rupture zones from overpressured portions of the crust) likely affects the nucleation and recurrence of successive earthquakes. A program of investigatory scientific drilling coupled to high-resolution geophysical investigations is proposed to target the lower seismogenic zone at depths of 5-10 km where larger inland earthquakes commonly initiate. It would aim to establish: (1) whether overpressuring extends throughout the full depth of sedimentary basins adjacent to active fault structures; (2) whether overpressures also exist in underlying basement assemblages; (3) whether overpressures are localized around the active fault structures; and, (4) the calibration of physical conditions responsible for observed geophysical anomalies. Unequivocal demonstration of overpressured pore fluids in basement rocks adjacent to an active fault would highlight the role of fluids in fault processes, providing important insights into the balance between stress-driven and fluid-driven failure, and critical variables affecting rupture nucleation and recurrence. Borehole measurements would also help to calibrate geophysical anomalies attributed to fluid overpressuring.

  5. Transverse shear stiffness of laminated anisotropic shells

    NASA Technical Reports Server (NTRS)

    Cohen, G. A.

    1978-01-01

    Equations are derived for the transverse shear stiffness of laminated anisotropic shells. Without making assumptions for thickness distribution for either transverse shear stresses or strains, constitutive equations for the transverse shear deformation theory of anisotropic heterogeneous shells are found. The equations are based on Taylor series expansions about a generic point for stress resultants and couples, identically satisfying plate equilibrium equations. These equations are used to find statically correct expressions for in-surface stresses, transverse shear stresses, and the area density of transverse shear strain energy, in terms of transverse shear stress resultants and redundants. The application of Castigliano's theorem of least work minimizes shear strain energy with respect to the redundants. Examples are presented for several laminated walls. Good agreement is found between the results and those of exact three-dimensional elasticity solutions for the cylindrical bending of a plate.

  6. Cesium oscillator strengths measured with a multiple-path-length absorption cell

    NASA Technical Reports Server (NTRS)

    Exton, R. J.

    1976-01-01

    Absorption-oscillator-strength measurements for the principal series in cesium were measured using a multiple-path-length cell. The optical arrangement included a movable transverse path for checking the uniformity of the alkali density along the length of the cell and which also allowed strength measurements to be made simultaneously on both strong and weak lines. The strengths measured on the first 10 doublets indicate an increasing trend in the doublet ratio. The individual line strengths are in close agreement with the high resolution measurements of Pichler (1974) and with the calculations of Norcross (1973).

  7. Transverse-longitudinal integrated resonator

    DOEpatents

    Hutchinson, Donald P. (Knoxville, TN); Simpson, Marcus L. (Knoxville, TN); Simpson, John T. (Knoxville, TN)

    2003-03-11

    A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

  8. Transversal magnetoresistance in Weyl semimetals

    NASA Astrophysics Data System (ADS)

    Klier, J.; Gornyi, I. V.; Mirlin, A. D.

    2015-11-01

    We explore theoretically the magnetoresistivity of three-dimensional Weyl and Dirac semimetals in transversal magnetic fields within two alternative models of disorder: (i) short-range impurities and (ii) charged (Coulomb) impurities. Impurity scattering is treated using the self-consistent Born approximation. We find that an unusual broadening of Landau levels leads to a variety of regimes of the resistivity scaling in the temperature-magnetic field plane. In particular, the magnetoresistance is nonmonotonous for the white-noise disorder model. For H ?0 the magnetoresistance for short-range impurities vanishes in a nonanalytic way as H1 /3. In the limits of strongest magnetic fields H , the magnetoresistivity vanishes as 1 /H for pointlike impurities, while it is linear and positive in the model with Coulomb impurities.

  9. Rupture process of the Wenchuan earthquake (Ms8.0) indicated by the characteristics of the surface rupture zones and the fault striations

    NASA Astrophysics Data System (ADS)

    Pan, J.; Li, H.; Si, J.; Pei, J.; Fu, X.

    2012-12-01

    On 12 May 2008, the Wenchuan earthquake (Ms 8.0) produced the most complicated yet longest thrust-type co-seismic surface rupture zone, which comprising the dextral-slip thrusting Yingxiu-Beichuan fault, the approximately pure thrusting Guanxian-Anxian fault, and the sinistral-slip thrusting Xiaoyudong rupture zone between the former two. Aiming at understanding the focal mechanism, here we discuss the rupture process by examining the segmentation and kinematic feature of the surface rupture zones, together with the co-seismic fault striations occur in various sites. Basing on the two displacement peaks, the different geometric and kinematic patterns for the southern and northern segment of the surface rupture zone, it is implied that the Wenchuan earthquake might consist of two rupture events, which is in agreement with the seismic wave inversion results. By comparing the kinematic feature of fault striations occur in the Bajiaomiao and Beichuan area, it is suggested that at the first stage, thrusting along both the Yingxiu-Beichuan fault and Guanxian-Anxian fault produced the about 80-100km long Yingxiu-Qingping surface rupture segment and Guanxian-Anxian surface rupture zone. Then, Beichuan fault was triggered by the first rupture process, causing the second rupture event, which was characterized by dextral strike-slip (or dextral oblique thrusting). Due to the overlap of the two rupture stages, the southern segment (Yingxiu-Qingping) of the Xingxiu-Beichuan rupture zone shows two different processes while the northern segment (Leigu-Beichuan-Nanba-Shikan) only suggests the second one. That is the reason why the Yingxiu-Beichuan surface rupture zone indicates both the thrusting and the dextral strike-slip, while the Guanxian-Anxian rupture zone is approximately pure thrusting. Considering that the earthquake is a dynamic and complicated physical process, though it can explain the development of the two different rupture zones, whether the model we discussed here is agree with the actual rupture process still need to be verified by the precise local seismic wave inversion.

  10. Transversal equalizer for the TDMA Intelsat services

    NASA Astrophysics Data System (ADS)

    Farell, E.; Riczker, L.; Kneve, H.; Berard, R.

    The considered transversal equalizer applies to a quadraphase shift keying (QPSK) system. Attention is given to the principle of operation, a block diagram of the transversal equalizer, the delay lines, an equivalent baseband model for a linear QPSK systems, an equivalent baseband model for a transversal equalizer component, aspects of RF summing, and test results. The tests performed in a fully-developed engineering model of the equalizer provide a verification of the desired features established as design goals.

  11. Environmental influence on the near-threshold fatigue crack propagation behaviour of a high-strength steel

    NASA Astrophysics Data System (ADS)

    Henaff, G.; Petit, J.; Bouchet, B.

    1992-07-01

    The near-threshold fatigue crack propagation behavior of a high-strength low-alloy steel has been investigated in ambient air and in vacuum so as to determine the role of the environment precisely. The analysis of the results is conducted by taking crack closure effects into account. It is concluded that fatigue crack growth rates measured in ambient air depend upon three processes: intrinsic fatigue crack propagation as observed in vacuum, adsorption of water vapor molecules on freshly created rupture surfaces, which enhances crack propagation, and a subsequent step of hydrogen-assisted cracking. The appearance of intergranular ruptures and oxide layers on rupture surfaces in ambient air is also discussed.

  12. SHOULDER STRENGTH PROFILES IN CHILDREN WITH AND WITHOUT BRACHIAL PLEXUS PALSY

    PubMed Central

    BROCHARD, SYLVAIN; ALTER, KATHARINE; DAMIANO, DIANE

    2015-01-01

    Introduction We characterized bilateral shoulder strength and the balance of antagonist/agonist muscle pairs in children with brachial plexus palsy (BPP) and with typical development (TD). Methods In 15 children with unilateral BPP and 11 with TD, bilateral maximal isometric shoulder strength in flexion/extension, internal/external rotation, and abduction/adduction was recorded using a hand-held dynamometer. Correlation between strength and active range of motion were evaluated using the Mallet score. Results Children with BPP had strength asymmetry in all muscles, whereas children with TD had significant strength asymmetry for flexors and abductors. In children with BPP, extensors and external rotators were the weakest muscles, leading to sagittal and transverse plane muscle imbalances. Higher strength values were related to better active range of motion. Conclusions This study highlights the importance of documenting shoulder strength profiles in children with BPP which may help predict deformity development. PMID:24307245

  13. Proximal Hamstring Repair Strength

    PubMed Central

    Harvey, Margaret Ann; Singh, Hardeep; Obopilwe, Elifho; Charette, Ryan; Miller, Suzanne

    2015-01-01

    Background: Proximal hamstring repair for complete ruptures has become a common treatment. There is no consensus in the literature about postoperative rehabilitation protocols following proximal hamstring repair. Some protocols describe bracing to prevent hip flexion or knee extension while others describe no immobilization. There are currently no biomechanical studies evaluating proximal hamstring repairs; nor are there any studies evaluating the effect of different hip flexion angles on these repairs. Hypothesis: As hip flexion increases from 0° to 90°, there will be a greater gap with cyclical loading. Study Design: Controlled laboratory study. Methods: Proximal hamstring insertions were detached from the ischial tuberosity in 24 cadavers and were repaired with 3 single-loaded suture anchors in the hamstring footprint with a Krakow suture technique. Cyclic loading from 10 to 125 N at 1 Hz was then performed for 0°, 45°, and 90° of hip flexion for 1500 cycles. Gap formation, stiffness, yield load, ultimate load, and energy to ultimate load were compared between groups using paired t tests. Results: Cyclic loading demonstrated the least amount of gap formation (P < .05) at 0° of hip flexion (2.39 mm) and most at 90° of hip flexion (4.19 mm). There was no significant difference in ultimate load between hip flexion angles (326, 309, and 338 N at 0°, 45°, and 90°, respectively). The most common mode of failure occurred with knot/suture failure (n = 17). Conclusion: Increasing hip flexion from 0° to 90° increases the displacement across proximal hamstring repairs. Postoperative bracing that limits hip flexion should be considered. Clinical Relevance: Repetitive motion involving hip flexion after a proximal hamstring repair may cause compromise of the repair.

  14. Creep and creep rupture of laminated graphite/epoxy composites. Ph.D. Thesis. Final Report, 1 Oct. 1979 - 30 Sep. 1980

    NASA Technical Reports Server (NTRS)

    Dillard, D. A.; Morris, D. H.; Brinson, H. F.

    1981-01-01

    An incremental numerical procedure based on lamination theory is developed to predict creep and creep rupture of general laminates. Existing unidirectional creep compliance and delayed failure data is used to develop analytical models for lamina response. The compliance model is based on a procedure proposed by Findley which incorporates the power law for creep into a nonlinear constitutive relationship. The matrix octahedral shear stress is assumed to control the stress interaction effect. A modified superposition principle is used to account for the varying stress level effect on the creep strain. The lamina failure model is based on a modification of the Tsai-Hill theory which includes the time dependent creep rupture strength. A linear cumulative damage law is used to monitor the remaining lifetime in each ply.

  15. Fault slip and rupture velocity inversion by isochrone backprojection

    NASA Astrophysics Data System (ADS)

    Festa, Gaetano; Zollo, Aldo

    2006-08-01

    A new technique is proposed here for the retrieval of slip images from the backprojection of high-frequency displacement records. When direct S waves are seen to be dominant in the near-source data, Green functions can be approximated by the far-field terms, as described by ray theory. Assuming that the slip rapidly reaches the final value (i.e. short slip duration), the measured displacement can be ascribed to the slip contributions lying on the corresponding isochrone on the fault plane. Here we use the far-field representation theorem to backproject on the fault plane the displacement amplitudes measured along the seismogram. Through the weighted stack of amplitude maps obtained from different stations we recover high slip zones on the fault. The resolution analysis of the backprojected images is realized with spike tests (that we refer to as `image Green functions'), which revealed to be an useful tool for detecting and locating artificial distortions of high slip patches, due to a poor data coverage. However, when the slip is uniformly spread along the isochrones, energy is scattered everywhere on the fault, leading to defocusing effects on the final images. A partial deconvolution technique is proposed by reiterating the backprojection. An important implication of this study is that slip maps can be obtained as functions of the rupture time on the fault, that is, the method can be used to retrieve variable rupture velocity kinematic models. Since the latter parameter is not known a priori, we suggest that a data set of coupled rupture velocity and slip maps is built up and the optimal model is chosen according to a waveform fitness criterion. This procedure allows the slip inversion to be separated from the rupture velocity inversion, significantly reducing the number of parameters to be estimated. Additionally, the parametrization of the rupture velocity is done on a less dense grid than the slip. By way of example, the technique is applied to estimation of the kinematic rupture model of the 2000 Tottori earthquake (M = 6.8), based on the inversion of near-source strong-motion data.

  16. Barrier-induced supershear ruptures on a slip-weakening fault

    NASA Astrophysics Data System (ADS)

    Weng, Huihui; Huang, Jinshui; Yang, Hongfeng

    2015-06-01

    Here we investigate the effects of a patch with elevated effective normal stress (barrier) on two-dimensional in-plane supershear rupture propagation on a planar fault from numerical experiments. Our results confirm that the barrier may slow down or stop coseismic ruptures but may also induce supershear ruptures. We demonstrate that the supershear rupture may emerge in a region that is delineated by two approximate linear boundaries. If the barrier size is below the lower boundary, ruptures can overcome the barrier and propagate at subshear speeds. If the barrier size is larger than the upper boundary, ruptures are always stopped by the barrier. Furthermore, we find that the barrier-induced supershear ruptures may eventually slow down into subshear speed, depending on the size and the location of the barrier. The duration of supershear ruptures increases as the barrier sizes grow from the lower to the upper boundary, which are proportional to the reduction in rupture speeds caused by the barrier. These results indicate that a barrier on the fault may not stop coseismic ruptures. Rather, the barrier may induce ruptures propagating at supershear speeds that play important roles in near-field ground shaking and damage.

  17. Rupture process of the 2013 Okhotsk deep mega earthquake from iterative backprojection and compress sensing methods

    NASA Astrophysics Data System (ADS)

    Qin, W.; Yin, J.; Yao, H.

    2013-12-01

    On May 24th 2013 a Mw 8.3 normal faulting earthquake occurred at a depth of approximately 600 km beneath the sea of Okhotsk, Russia. It is a rare mega earthquake that ever occurred at such a great depth. We use the time-domain iterative backprojection (IBP) method [1] and also the frequency-domain compressive sensing (CS) technique[2] to investigate the rupture process and energy radiation of this mega earthquake. We currently use the teleseismic P-wave data from about 350 stations of USArray. IBP is an improved method of the traditional backprojection method, which more accurately locates subevents (energy burst) during earthquake rupture and determines the rupture speeds. The total rupture duration of this earthquake is about 35 s with a nearly N-S rupture direction. We find that the rupture is bilateral in the beginning 15 seconds with slow rupture speeds: about 2.5km/s for the northward rupture and about 2 km/s for the southward rupture. After that, the northward rupture stopped while the rupture towards south continued. The average southward rupture speed between 20-35 s is approximately 5 km/s, lower than the shear wave speed (about 5.5 km/s) at the hypocenter depth. The total rupture length is about 140km, in a nearly N-S direction, with a southward rupture length about 100 km and a northward rupture length about 40 km. We also use the CS method, a sparse source inversion technique, to study the frequency-dependent seismic radiation of this mega earthquake. We observe clear along-strike frequency dependence of the spatial and temporal distribution of seismic radiation and rupture process. The results from both methods are generally similar. In the next step, we'll use data from dense arrays in southwest China and also global stations for further analysis in order to more comprehensively study the rupture process of this deep mega earthquake. Reference [1] Yao H, Shearer P M, Gerstoft P. Subevent location and rupture imaging using iterative backprojection for the 2011 Tohoku Mw 9.0 earthquake. Geophysical Journal International, 2012, 190(2): 1152-1168. [2]Yao H, Gerstoft P, Shearer P M, et al. Compressive sensing of the Tohoku-Oki Mw 9.0 earthquake: Frequency-dependent rupture modes. Geophysical Research Letters, 2011, 38(20).

  18. Telescoping of sheaths-an easy technique to facilitate the removal of a stuck ruptured transluminal angioplasty balloon.

    PubMed

    Sequeira, Adrian; Artikov, Shukhrat

    2014-01-01

    Balloon rupture during angioplasty is an uncommon event. The ruptured balloon usually is removed through its introducer sheath without any problems. However, there may be occasions when a ruptured balloon cannot be withdrawn from an access. We describe a simple technique that can be used to extricate a stuck ruptured angioplasty balloon. PMID:25250769

  19. Management of Hepatic Rupture Diagnosed after an Emergency Cesarean Section

    PubMed Central

    Damiani, Gianluca Raffaello; Merola, Viviana; Barnaba, Mario; Landi, Stefano; Cormio, Gennaro; Pellegrino, Antonio

    2014-01-01

    A careful management of hepatic capsular rupture, with massive hemoperitoneum which occurred 14 hours after an emergency cesarean section at 36 weeks of gestation, is meticulously reported. The grade of hepatic involvement varies from minor capsular laceration to extensive parenchymal rupture. Our management involved a combination of surgical interventions and aggressive supportive care. The patient was discharged after 53 days and 4 laparotomies and an unsuccessful attempt of superselective artery embolization. Ultrasound after 40 days from the last surgery showed uniform hepatic parenchyma free of focal lesions. Due to the rarity and the unpredictability nature of this devastating event we believe necessary to report our experience, reinforcing the importance of the postsurgery management. PMID:25254049

  20. Isolated posterior capsular rupture following blunt head trauma

    PubMed Central

    Mansour, Ahmad M; Jaroudi, Mahmoud O; Hamam, Rola N; Maalouf, Fadi C

    2014-01-01

    Closed-globe traumatic cataract is not uncommon in males in the pediatric age group. However, there is a relative paucity of literature on isolated posterior lens capsule rupture associated with closed-globe traumatic cataract. We report a case of a 6-year-old boy who presented with white cataract 1 day after blunt trauma to the forehead associated with posterior capsular rupture that was detected by B-scan ultrasonography preoperatively. No stigmata of trauma outside the posterior capsule could be detected by slit-lamp exam, funduscopy, and optical coherence tomography. Phacoemulsification with posterior chamber intraocular lens implant was performed 24 hours after trauma, with the patient achieving 6/6 visual acuity 1 week and 6 months after surgery. Our case is unique, being the youngest (amblyogenic age) to be reported, with prompt surgical intervention, and with no signs of trauma outside the posterior capsule. PMID:25506201

  1. Spontaneous Rupture of Uterine Vein in Twin Pregnancy

    PubMed Central

    Doger, Emek; Cakiroglu, Yigit; Yildirim Kopuk, Sule; Akar, Bertan; Caliskan, Eray; Yucesoy, Gulseren

    2013-01-01

    Objective. Aim of our study is to present a case of a twin pregnancy following invitro fertilization cycle complicated with hemoperitoneum at third trimester. Case. A 26-year-old nulliparous pregnant woman at 32 weeks of gestation with twin pregnancy following invitro fertilization cycle complained of abdominal pain. After 48 hours of admission, laparotomy was performed with indications of aggravated abdominal pain and decreased hemoglobin levels. Utero-ovarian vein branch rupture was detected on the right posterior side of uterus and bleeding was stopped by suturing the vein. Etiopathogenesis of the present case still remains unclear. Conclusion. Spontaneous rupture of the uterine vessels during pregnancy is a rare complication and may lead to maternal and fetal morbidity and mortality. Diagnosis and treatment are based on the clinical symptoms of acute abdominal pain and laboratory tests of hypovolemic shock signs. PMID:24455353

  2. [Traumatic Testicular Rupture Complicated with Hydrocele: A Case Report].

    PubMed

    Yamamichi, Gaku; Tsutahara, Koichi; Okusa, Takuya; Taniguchi, Ayumu; Kishimoto, Nozomu; Tanigawa, Go; Takao, Tetsuya; Yamaguchi, Seiji

    2015-10-01

    A 17-year-old man presented with right hydrocele because of an athletic injury. His scrotum was hit with a ball 2 months ago while playing baseball. He was diagnosed with post-traumatic hydrocele and underwent needle puncture at another hospital 1 month after the trauma. However, the hydrocele did not improve. Therefore, he was referred to our hospital for surgical treatment. For diagnosis of the traumatic hydrocele testis, a hydrocelectomy was scheduled. When we opened the tunica vaginalis, we realized that the tunica albuginea had been ruptured and the testicular parenchyma had gushed out. We tried to replace all the escaped testicular parenchyma into the tunica albuginea, but it was impossible. Therefore were moved some of the redundant testicular parenchyma, and replaced the remnants into the tunica albuginea. After the operation, right hydrocele and testicular atrophy did not occur. Traumatic testicular rupture complicated with hydrocele is rare. PMID:26563625

  3. Effect of heating method on stress-rupture life

    NASA Technical Reports Server (NTRS)

    Bizon, P. T.; Calfo, F. D.

    1977-01-01

    The effect of radiant(furnace), resistance(electric current), burner(hot gas stream), and a combination of resistance and burner heating on intermediate time (100 to 300 hr) stress-rupture life and reduction of area was evaluated. All heating methods were studied using the nickel-based alloy Udimet 700 while all but burner heating were evaluated with the cobalt-based alloy Mar-M 509. Limited test results of eight other superalloys were also included in this study. Resistance heated specimens had about 20 to 30 percent of the stress-rupture life of radiant heated specimens. The limited burner heating data showed about a 50 percent life reduction as compared to the radiant heated tests. A metallurgical examination gave no explanation for these reductions.

  4. Effect of salicylhydroxamic acid on endosperm strength and embryo growth of Lactuca sativa L. cv Waldmann's Green seeds

    NASA Technical Reports Server (NTRS)

    Brooks, C. A.; Mitchell, C. A.

    1988-01-01

    Salicylhydroxamic acid (SHAM) stimulated germination of photosensitive lettuce (Lactuca sativa L. cv Waldmann's Green) seeds in darkness. To determine whether SHAM acts on the embryo or the endosperm, we investigated separately effects of SHAM on growth potential of isolated embryos as well as on endosperm strength. Embryo growth potential was quantified by incubating decoated embryos in various concentrations of osmoticum and measuring subsequent radicle elongation. Growth potential of embryos isolated from seeds pretreated with 4 millimolar SHAM was equal to that of untreated controls. Rupture strength of endosperm tissue excised from seeds pretreated with SHAM was 33% less than that of controls in the micropylar region. To determine if the embryo must be in contact with the endosperm of SHAM to weaken the endosperm, some endosperms were incubated with SHAM only after dissection from seeds. Rupture strength of SHAM-treated, isolated endosperms in the micropylar region was 25% less than that of untreated controls. There was no difference in rupture strength in the cotyledonary region of endosperm isolated from seeds treated with SHAM in buffer or buffer alone. SHAM therefore stimulates germination not by enhancing embryo growth potential, but by weakening the micropylar region of the endosperm enclosing the embryo.

  5. Ruptured Baker's cyst with compartment syndrome: an extremely unusual complication.

    PubMed

    Hamlet, Mark; Galanopoulos, Ilias; Mahale, Avinash; Ashwood, Neil

    2012-01-01

    A 69-year-old man presented with sudden onset of pain with acute tense swelling of his left leg. Initially he was treated empirically with antibiotics for cellulitis while the possibility of deep vein thrombosis was ruled out. His symptoms gradually worsened with progressive distal neurological deficit and increasing pain. Further investigations suggested that he had a ruptured Baker's cyst in the calf with development of compartment syndrome. PMID:23264161

  6. The dependence of the dry friction threshold on rupture dynamics

    E-print Network

    Ben-David, Oded

    2011-01-01

    The static friction coefficient between two materials is considered to be a material constant. We present experiments demonstrating that the ratio of shear to normal force needed to move contacting blocks can, instead, vary systematically with controllable changes in the external loading configuration. Large variations in both the friction coefficient and consequent stress drop are tightly linked to changes in the rupture dynamics of the rough interface separating the two blocks.

  7. Analysis of uterine rupture at university teaching hospital Pakistan

    PubMed Central

    Aziz, Nousheen; Yousfani, Sajida

    2015-01-01

    Objective: To determine the risk factors, management modalities, fetomaternal outcome of uterine rupture cases at University teaching hospital in Pakistan. Methods: This retrospective descriptive study was conducted at the Department of Gynaecology and Obstetrics Liaquat University of Medical and Health Sciences (LUMHS) for a period of one year from January 1st to December 31st 2012. Main outcome measures were frequency, age, parity, booking status, risk factors, management modalities, fetal and maternal mortality associated with uterine rupture. The data was collected on pre-designed proforma analysed using SPSS Version 16 statistical package. Results: The frequency of ruptured uteri was calculated to be 0.67%, giving a ratio of 1:148 deliveries. Highest incidence was found in age group 25-30 (44.26%) with mean age of 30.36 years. and parity group 2-3 (57.37%) with mean parity 4.08. The risk factors for ruptured uterus include Caesarean section 43(70.49%), injudicious use of oxytocin 33(54.09%), obstructed labour 15 (24.59%) and multiparty 18 (29.50%). Repair of uterus was performed in 47(77.04%) cases. Maternal case fatality was 5(8.19%), while foetal wastage was 51 (83.60%). Conclusion: This study confirms the existence of a serious preventable obstetric problem, with significant maternal mortality and foetal wastage. Integrated efforts include Health education, focused antenatal care, skilled attendance, avoidance of injudicious use of oxytocin, and need of hospital based deliveries in patients with caesarean section which should be intensified to reduce this drastic obstetrical complication. PMID:26430430

  8. Bilateral Wünderlich Syndrome Caused by Spontaneous Rupture of Renal Angiomyolipomas

    PubMed Central

    Sotošek, Stanislav; Marki?, Dean; Španjol, Josip; Krpina, Kristian; Kneževi?, Siniša; Mari?i?, Anton

    2015-01-01

    Wünderlich syndrome (WS) is a urological emergency characterized by retroperitoneal hemorrhage. In most cases, bleeding occurs from a renal angiomyolipoma (AML) and may be the first manifestation of the disease. We report a female patient with bilateral WS due to the metachronous rupture of renal AMLs. Because the patient was stable and the tumor was not malignant, treatment was conservative. Follow-up revealed the full recovery of kidney function and the resolution of the hematoma. PMID:25793141

  9. Atraumatic splenic rupture and ileal volvulus following cocaine abuse.

    PubMed

    Ballard, David H; Smith, J Patrick; Samra, Navdeep S

    2015-01-01

    We present the case of a 38-year-old male with an atraumatic splenic rupture, hemoperitoneum, and ileal volvulus following acute cocaine intoxication. Computed tomography showed a "whirl sign", a subcapsular splenic hematoma with suspected peripheral laceration, and diffuse hemoperitoneum. At laparotomy, the spleen was confirmed to be the source of bleeding and was removed. A nonreducible volvulus was found at the distal ileum, and this segment of small bowel was removed. The patient had an uneventful postoperative recovery. PMID:26324218

  10. Choriocarcinoma with Uterine Rupture and Shock: A Rare Case Report

    PubMed Central

    Agarwal, Manika; Pyrbot, Jupirika; Singh, A.S.

    2015-01-01

    Choriocarcinoma is a rare neoplasm and a malignant form of gestational trophoblastic disease. Choriocarcinoma is frequently preceded by a complete mole, ectopic pregnancy, nonmolar intrauterine abortion, and uncommonly by a partial mole. It is treated medically with chemotherapeutic drugs usually. However, we managed to save a life with appropriate and timely surgical intervention in a case of choriocarcinoma who presented with uterine rupture, haemoperitoneum, anaemia and hypovolemic shock. The patient underwent exploratory laparotomy and hysterectomy followed by systemic chemotherapy. PMID:26557535

  11. Management of hepatocellular carcinoma rupture in the caudate lobe

    PubMed Central

    Hong, De-Fei; Liu, Ying-Bin; Peng, Shu-You; Pang, Jin-Zhong; Wang, Zhi-Fei; Cheng, Jian; Shen, Guo-Liang; Zhang, Yuan-Biao

    2015-01-01

    AIM: To demonstrate that caudate lobectomy is a valid treatment in cases of hepatocellular carcinoma (HCC) rupture in the caudate lobe based on our experience with the largest case series reported to date. METHODS: A retrospective study of eight patients presenting with spontaneous rupture and hemorrhage of HCC in the caudate lobe was conducted. Two patients underwent ineffective transarterial embolization preoperatively. Caudate lobectomy was performed in all eight patients. Bilateral approach was taken in seven cases for isolated complete caudate lobectomy. Left-sided approach was employed in one case for isolated partial caudate lobectomy. Transarterial chemoembolization was performed postoperatively in all patients. RESULTS: Caudate lobectomy was successfully completed in all eight cases. The median time delay from the diagnosis to operation was 5 d (range: 0.25-9). Median operating time was 200 min (range: 120-310) with a median blood loss of 900 mL (range: 300-1500). Five patient remained in long-term follow-up, with one patient becoming lost to follow-up at 3 years and two patients currently alive at 7 and 19 mo. One patient required reoperation due to recurrence. Gamma knife intervention was performed for brain metastasis in another case. Two patients survived for 10 and 84 mo postoperatively, ultimately succumbing to multiple organ metastases. CONCLUSION: Caudate lobectomy is the salvage choice for HCC rupture in the caudate lobe. Local anatomy and physiologic features of the disease render caudate lobectomy a technically difficult operation. Postponement of surgical intervention is thus recommended while the rupture remains hemodynamically stable until an experienced surgeon becomes available. Prognosis is confounded by numerous factors, but long-term survival can be expected in the majority of cases. PMID:26185390

  12. Evolution of the helicity and transversity Transverse-Momentum-Dependent parton distributions

    SciTech Connect

    Prokudin, Alexey; Bacchetta, Alessandro

    2013-10-01

    We examine the QCD evolution of the helicity and transversity parton distribution functions when including also their dependence on transverse momentum. Using an appropriate definition of these polarized transverse momentum distributions (TMDs), we describe their dependence on the factorization scale and rapidity cutoff, which is essential for phenomenological applications.

  13. Evolution of the helicity and transversity Transverse-Momentum-Dependent parton distributions

    SciTech Connect

    Prokudin, Alexei; Bacchetta, Alessandro

    2013-07-01

    We examine the QCD evolution of the helicity and transversity parton distribution functions when including also their dependence on transverse momentum. Using an appropriate definition of these polarized transverse momentum distributions (TMDs), we describe their dependence on the factorization scale and rapidity cutoff, which is essential for phenomenological applications.

  14. Prepubescent Strength Training. Some Considerations.

    ERIC Educational Resources Information Center

    Priest, Joe W.; Holshouser, Richard S.

    1987-01-01

    Under the careful supervision of a trained fitness professional, the benefits of prepubescent strength training (improved strength, power, muscular endurance, bone density) outweigh the risks (acute and chronic musculoskeletal injuries). (CB)

  15. Acute transverse myelopathy complicating systemic lupus erythematosus.

    PubMed Central

    Propper, D J; Bucknall, R C

    1989-01-01

    A sixteen year old girl with systemic lupus erythematosus developed acute transverse myelopathy. She was treated with high dose steroids, cyclophosphamide, and plasma exchange and regained partial neurological function. Previous descriptions of transverse myelopathy complicating systemic lupus erythematosus are reviewed, with particular reference to the efficacy of high dose steroid treatment. PMID:2662918

  16. W Boson production at large transverse momentum.

    E-print Network

    Kidonakis, Nikolaos; Sabio Vera, Agustin

    The production of W bosons at large transverse momentum in p¯p collisions is studied. The next-to-leading order cross section in this region is dominated by threshold soft-gluon corrections. The transverse momentum distribution of the W...

  17. Transverse instability at the recycler ring

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2004-10-01

    Sporadic transverse instabilities have been observed at the Fermilab Recycler Ring leading to increase in transverse emittances and beam loss. The driving source of these instabilities has been attributed to the resistive-wall impedance with space-charge playing an important role in suppressing Landau damping. Growth rates of the instabilities are computed. Remaining problems are discussed.

  18. Cladding For Transversely-Pumped Laser Rod

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  19. Transverse impedance localization using intensity dependent optics

    SciTech Connect

    Calaga,R.; Arduini, G.; Metral, E.; Papotti, G.; Quatraro, D.; Rumolo, G.; Salvant, B.; Tomas, R.

    2009-05-04

    Measurements of transverse impedance in the SPS to track the evolution over the last few years show discrepancies compared to the analytical estimates of the major contributors. Recent measurements to localize the major sources of the transverse impedance using intensity dependent optics are presented. Some simulations using HEADTAIL to understand the limitations of the reconstruction and related numerical aspects are also discussed.

  20. Vortex dynamics in ruptured and unruptured intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Trylesinski, Gabriel; Varble, Nicole; Xiang, Jianping; Meng, Hui

    2013-11-01

    Intracranial aneurysms (IAs) are potentially devastating pathological dilations of arterial walls that affect 2-5% of the population. In our previous CFD study of 119 IAs, we found that ruptured aneurysms were correlated with complex flow pattern and statistically predictable by low wall shear stress and high oscillatory shear index. To understand flow mechanisms that drive the pathophysiology of aneurysm wall leading to either stabilization or growth and rupture, we aim at exploring vortex dynamics of aneurysmal flow and provide insight into the correlation between the previous predictive morphological parameters and wall hemodynamic metrics. We adopt the Q-criterion definition of coherent structures (CS) and analyze the CS dynamics in aneurysmal flows for both ruptured and unruptured IA cases. For the first time, we draw relevant biological conclusions concerning aneurysm flow mechanisms and pathophysiological outcome. In pulsatile simulations, the coherent structures are analyzed in these 119 patient-specific geometries obtained using 3D angiograms. The images were reconstructed and CFD were performed. Upon conclusion of this work, better understanding of flow patterns of unstable aneurysms may lead to improved clinical outcome.

  1. Ruptured aneurysms of the aortic sinus of Valsalva.

    PubMed

    Chia, B L; Tan, N C; Lim, C H; Tan, L K; Toh, C C; Johan, A

    1975-01-01

    Aneurysms of the aortic sinus of Valsalva (ASV) are uncommon. This study describes eight cases of ruptured aneurysms of the congenital variety observed over a 10-year period in Singapore. Although ASV is classically diagnosed at the time of rupture, only one patient in this series presented with acute chest pain and dyspnea. All eight patients had continuous murmurs. The clinical diagnosis was confirmed by cardiac catheterization and angiography in eight patients and by thoracotomy in six. In six patients, the aneurysm had ruptured into the right ventricle and in two into the right atrium. In the five patients where the site of the aneurysm could be definitely determined, four arose from the right coronary and one from the noncoronary sinus. This marked preponderance of right coronary sinus over noncoronary sinus aneurysm in Singapore is more in accordance with the Japanese rather than the Western experience. A systolic gradient due to the aneurysm pressing on the right ventricular outflow tract was established in four patients during cardiac catheterization and angiography and confirmed in three patients at thoracotomy. Six patients underwent operation and were alive and well from 7 months to 3 years later. PMID:1220871

  2. The Rupture Behaviour Of Woven Fabrics Containing Kevlar Fibres

    NASA Astrophysics Data System (ADS)

    Mao, N.; Qu, J.; Darley, M.; Lingard, S.

    2012-07-01

    Woven fabrics containing high performance fibres are frequently used in spacecraft structures and the rupture behaviour of these fabrics heavily influences the performance of its final products. However, the initiation and propagation of a ruptured fracture in the woven fabrics is not clear and the interpretation of the results from different tear testing methods varies. Currently there is a lack of knowledge about both the characteristics of tear propagation woven fabrics containing high performance fibres such as Kevlar and the influence of the fabric structural parameters on the rupture behaviour of the fabrics; this knowledge gap creates difficulties for the engineering design and selection of suitable fabric materials to meet specific requirements in each application case involving such woven fabrics. In this paper, the tear propagations in a polyurethane-coated woven fabric containing Kevlar fibres based on two different tear testing standards are examined; the mechanism of tear propagation in woven fabrics and the influences of tear testing design on the interpretation of the results from different tear testing methods are discussed. It is expected that the results will guide both the engineering design of Kevlar woven fabric structures and the evaluation of the fabric performance.

  3. Acute pancreatitis complicated with splenic rupture: A case report

    PubMed Central

    Hernani, Bruno L; Silva, Pedro C; Nishio, Ricardo T; Mateus, Henrique C; Assef, José C; De Campos, Tercio

    2015-01-01

    Atraumatic splenic rupture is an uncommon complication of acute pancreatitis. This report describes the case of a 30-year-old man with acute pancreatitis and splenic vein thrombosis complicated by splenic rupture. The patient was admitted to the emergency department with pain in the upper abdomen that had been present for six hours and was associated with vomiting and sweating. He was diagnosed with acute pancreatitis of alcoholic etiology. Upon computed tomography (CT) of the abdomen, the pancreatitis was scored as Balthazar C grade, and a suspicious area of necrosis affecting 30% of the pancreas with splenic vein thrombosis was revealed. Seventy-two hours after admission, the patient had significant improvement in symptoms. However, he showed clinical worsening on the sixth day of hospitalization, with increasing abdominal distension and reduced hemoglobin levels. A CT angiography showed a large amount of free fluid in the abdominal cavity, along with a large splenic hematoma and contrast extravasation along the spleen artery. The patient subsequently underwent laparotomy, which showed hemoperitoneum due to rupture of the splenic parenchyma. A splenectomy was then performed, followed by ultrasound-guided percutaneous drainage. PMID:26425272

  4. Monatomic metal nanowires: Rupture kinetics and mean lifetime

    NASA Astrophysics Data System (ADS)

    Michailov, Michail; Kashchiev, Dimo

    2015-06-01

    We present a model for the kinetics of spontaneous (unforced) rupture of monatomically thick metal nanowire on atomically smooth crystal face. The nanowire breaks down spontaneously solely because of the thermal motion of the atoms in it and the underlying crystal. Our model describes the nanowire rupture as a three-step process involving (i) appearance of atoms active in vacating their positions, (ii) generation of atomic vacancies, and (iii) formation of holes (vacancy dimers) in the nanowire. The model is based on Monte Carlo simulation results for the temporal evolution of initially straight monatomic chain of Cu atoms on Cu(111) crystal face. The simulation provides data for the time dependence of the number Nv of vacancies and the number Nh of holes in the nanowire, as well as for the probabilities Pv and Ph to form, respectively, at least one vacancy and at least one hole until time t. We describe the nanowire rupture kinetics by using rate equations and obtain expressions for the nanowire mean lifetime and the Nv(t), Nh(t), Pv(t), and Ph(t) dependences. These expressions are found to conform well to the simulation data, which implies a Poissonian random appearance of the first few vacancies and holes in the nanowire.

  5. Internal carotid artery rupture caused by carotid shunt insertion

    PubMed Central

    Illuminati, Giulio; Caliò, Francesco G.; Pizzardi, Giulia; Vietri, Francesco

    2015-01-01

    Introduction Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. Presentation of case A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Discussion Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Conclusion Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. PMID:26255001

  6. Accelerated stress rupture lifetime assessment for fiber composites

    SciTech Connect

    Groves, S.E.; DeTeresa, S.J.; Sanchez, R.J.; Zocher, M.A.; Christensen, R.M.

    1997-02-01

    Objective was to develop a theoretical and experimental framework for predicting stress rupture lifetime for fiber polymer composites based on short-term accelerated testing. Originally a 3-year project, it was terminated after the first year, which included stress rupture experiments and viscoelastic material characterization. In principle, higher temperature, stress, and saturated environmental conditions are used to accelerate stress rupture. Two types of specimens were to be subjected to long-term and accelerated static tensile loading at various temperatures, loads in order to quantify both fiber and matrix dominated failures. Also, we were to apply state-of-the-art analytical and experimental characterization techniques developed under a previous DOE/DP CRADA for capturing and tracking incipient degradation mechanisms associated with mechanical performance. Focus was increase our confidence to design, analyze, and build long-term composite structures such as flywheels and hydrogen gas storage vessels; other applications include advanced conventional weapons, infrastructures, marine and offshore systems, and stockpile stewardship and surveillance. Capabilities developed under this project, though not completed or verified, are being applied to NIF, AVLIS, and SSMP programs.

  7. Acute pancreatitis complicated with splenic rupture: A case report.

    PubMed

    Hernani, Bruno L; Silva, Pedro C; Nishio, Ricardo T; Mateus, Henrique C; Assef, José C; De Campos, Tercio

    2015-09-27

    Atraumatic splenic rupture is an uncommon complication of acute pancreatitis. This report describes the case of a 30-year-old man with acute pancreatitis and splenic vein thrombosis complicated by splenic rupture. The patient was admitted to the emergency department with pain in the upper abdomen that had been present for six hours and was associated with vomiting and sweating. He was diagnosed with acute pancreatitis of alcoholic etiology. Upon computed tomography (CT) of the abdomen, the pancreatitis was scored as Balthazar C grade, and a suspicious area of necrosis affecting 30% of the pancreas with splenic vein thrombosis was revealed. Seventy-two hours after admission, the patient had significant improvement in symptoms. However, he showed clinical worsening on the sixth day of hospitalization, with increasing abdominal distension and reduced hemoglobin levels. A CT angiography showed a large amount of free fluid in the abdominal cavity, along with a large splenic hematoma and contrast extravasation along the spleen artery. The patient subsequently underwent laparotomy, which showed hemoperitoneum due to rupture of the splenic parenchyma. A splenectomy was then performed, followed by ultrasound-guided percutaneous drainage. PMID:26425272

  8. Mécanismes de rupture d'interfaces sous sollicitation dynamique rapide

    NASA Astrophysics Data System (ADS)

    Bolis, C.; Berthe, L.; Boustie, M.; Arrigoni, M.; Jeandin, M.; Barradas, S.

    2003-03-01

    Le test d'adhérence par choc laser (LASer Adhesion Test : LASAT) est développé afin de devenir une mesure non destructrice de l'adhérence à l'interface entre deux matériaux. Cette technique utilise un laser impulsionnel de forte puissance pour générer une onde de choc se propageant dans le substrat puis dans la couche. Des contraintes de traction peuvent ainsi être induites entre la couche et le substrat par le jeu des réflexions sur les différentes interfaces du système. La rupture peut être détectée sur l'historique de la vitesse de la face opposée au laser. Celle ci est mesurée par vélocimétrie Doppler de type VISAR (Velocity Interferometer System for Any Reflector). Les résultats expérimentaux obtenus sur un système (substrat : aluminium, couche : cuivre) déposé par projection plasma permettent de valider cette nouvelle technique. En particulier, le test permet d'étudier l'influence des paramètres de projection sur l'adhérence entre le cuivre et l'aluminium. Par ailleurs, une première interprétation numérique des mécanismes de rupture sous sollicitation dynamique est donnée grâce à l'utilisation de différents critères de rupture dans un code de propagation des chocs.

  9. Near-field tsunami edge waves and complex earthquake rupture

    USGS Publications Warehouse

    Geist, Eric L.

    2013-01-01

    The effect of distributed coseismic slip on progressive, near-field edge waves is examined for continental shelf tsunamis. Detailed observations of edge waves are difficult to separate from the other tsunami phases that are observed on tide gauge records. In this study, analytic methods are used to compute tsunami edge waves distributed over a finite number of modes and for uniformly sloping bathymetry. Coseismic displacements from static elastic theory are introduced as initial conditions in calculating the evolution of progressive edge-waves. Both simple crack representations (constant stress drop) and stochastic slip models (heterogeneous stress drop) are tested on a fault with geometry similar to that of the M w = 8.8 2010 Chile earthquake. Crack-like ruptures that are beneath or that span the shoreline result in similar longshore patterns of maximum edge-wave amplitude. Ruptures located farther offshore result in reduced edge-wave excitation, consistent with previous studies. Introduction of stress-drop heterogeneity by way of stochastic slip models results in significantly more variability in longshore edge-wave patterns compared to crack-like ruptures for the same offshore source position. In some cases, regions of high slip that are spatially distinct will yield sub-events, in terms of tsunami generation. Constructive interference of both non-trapped and trapped waves can yield significantly larger tsunamis than those that produced by simple earthquake characterizations.

  10. Silicone breast implant rupture presenting as bilateral leg nodules.

    PubMed

    Sagi, L; Baum, S; Lyakhovitsky, A; Barzilai, A; Shpiro, D; Trau, H; Goldan, O; Winkler, E

    2009-07-01

    Gross migration of silicone gel from ruptured breast implants is a rare event. It is associated with extravasation of gel into the breast parenchyma, and to distant locations such as the abdominal wall and inguinal areas. This silicone deposits present as subcutaneous nodules and cause a local reaction known as siliconoma. We evaluated a 56-year-old woman who presented with a 2-year history of painful, firm and ill-defined subcutaneous nodules on the medial aspect of the shins and ankles. Her medical history was notable for bilateral breast augmentation with silicone implants 30 years before presentation. Although there were no signs or symptoms on breast examination, ultrasonography and magnetic resonance imaging confirmed that both implants had ruptured. Histological examination of a punch biopsy from a nodule on the shin found lobular granulomatous panniculitis. An excisional biopsy of the lesion was analysed by scanning electron microscopy and was found to contain silicone. This is a rare case of gross migration of silicone to the shins, originating from ruptured breast implants. To our knowledge, there is no previous report of silicone migration to such a distant location. We discuss the common presentation of silicone migration and highlight the importance of awareness among dermatologists and plastic surgeons about this unusual occurrence. PMID:19438562

  11. Endovascular Repair of Contained Rupture of the Thoracic Aorta

    SciTech Connect

    Morgan, Robert; Loosemore, Tom; Belli, Anna-Maria

    2002-08-15

    Purpose: To assess the efficacy of stent-grafts for the treatment of acute rupture of the thoracic aorta. Methods: Four patients with acute contained ruptures of the thoracic aorta were treated by insertion of stent-grafts. The underlying aortic lesions were aneurysm, acute aortic ulcer, acute type B dissection and giant cell aortitis. The procedures were performed under general anesthesia in three patients and local anesthesia in one patient. Results: All stent-grafts were successfully deployed. All patients survived the procedure and are now alive and well at follow-up (mean 6.3 months, range 44 days-16 months). One patient underwent a second stent procedure 10 days after the first procedure because of a proximal endoleak. All hemothoraces have resolved. There were no complications. Conclusion:Treatment of acute contained ruptures of the thoracic aorta by the insertion of stent-grafts is feasible. The technical success rates,complication rates and patient survival compare favorably with emergency surgery.

  12. Flow and rupture of vesicles in narrow channels

    NASA Astrophysics Data System (ADS)

    Harman, Alison; Bertrand, Martin; Joos, Bela

    2012-02-01

    Small lipid bilayer vesicles, also known as liposomes, are used for drug delivery systems in vasculature. Consequently how they deform and when they become unstable and rupture (lose their inner contents) under capillary flow is of great interest. In addition vesicles with a filling fraction of 0.6 can be considered as a simple mechanical model of red blood cells. We use coarse-grained molecular dynamics (CGMD) simulations with explicit solvent to study lipid bilayer vesicles in 3D capillary flow with filling fractions of 1.0 and 0.6. The shapes of the vesicles obtained in these simulations compare well to other experimental and theoretical studies. Using CGMD allows the study of rupture. This is in contrast to the majority of other approaches which model the bilayer as a purely elastic surface and only allow the investigation of deformation. We look at the stress profiles of these vesicles as measured by the area expansion per lipid along the membrane, and determine the location and pressure of rupture for a given confinement ratio (diameter of the vesicle divided by diameter of the channel). We also discuss the subsequent loss of inner fluid content.

  13. Seismotectonics of the easternmost transverse ranges, California: Relevance for seismic potential of the southern San Andreas Fault

    NASA Astrophysics Data System (ADS)

    Williams, Patrick L.; Sykes, Lynn R.; Nicholson, Craig; Seeber, Leonardo

    1990-02-01

    Earthquake locations, depths and focal mechanisms from the Southern California Regional Network (1977-1985) are used to identify the orientation and sense of slip of active subsurface faults in the Easternmost Transverse Ranges (ETR). The ETR are separated from the Salton Trough province by the southernmost strands of the San Andreas fault (SAF). Much of the seismicity in the ETR is concentrated well northeast of the SAF at relatively shallow depths under the Little San Bernardino Mountains. Many of these earthquakes reflect slip on steeply dipping, left-lateral faults striking northeast to east, at relatively high angles to the adjacent SAF. Focal mechanisms in the ETR show predominantly strike-slip, normal, or oblique-normal faulting, and share common near-horizontal T axes striking WNW. P axes range from near vertical to near horizontal and strike mostly NNE. In contrast, reverse and strike-slip focal mechanisms that exhibit persistent north trending, near-horizontal P axes characterize the San Gorgonio Pass area immediately to the west. These different patterns of strain geometries are inferred to represent changes in local stress regime and clearly establish a boundary between contrasting tectonic styles of contemporary secondary deformation along the SAF. This boundary, which in the Coachella Valley may be the Mission Creek fault, is also distinguished by abrupt changes in (1) rate and depth of seismic activity; (2) topography; (3) Quaternary vertical deformation; (4) strikes and dips of major branches of the SAF; and (5) seismic velocities in the crust and upper mantle. The preponderance of secondary normal faulting in the ETR versus secondary reverse faulting in the San Gorgonio Pass region suggests that fault-normal stress is much less across the SAF adjacent to the ETR. If a friction law where strength is proportional to normal stress applies to the SAF, then a smaller tectonic shear stress would be required tor slip in large earthquakes along the Salton Trough segment. In this case, the southernmost SAF may have shorter repeat times, smaller average displacements, and lower moment release rates than earthquakes that rupture through the major restraining bend in San Gorgonio Pass.

  14. TOT: the association strength heuristic 

    E-print Network

    Choi, Hyun

    2005-11-01

    that the frequency and strength of TOTs linearly increased as a function of number of co-occurrences; the correlation between TOT strength and the participants?? subjective estimation of number of co-occurrences was greater than the correlation between TOT strength...

  15. Strength Development for Young Adolescents

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; Jackson, Allen; Gaudet, Laura

    2009-01-01

    Participation in strength training is important for older children or young adolescences who wish to improve fitness or participate in sports. When designing strength training programs for our youth this age group is immature anatomically, physiologically, and psychologically. For the younger or inexperienced group the strength training activities…

  16. Strength Training and Children's Health.

    ERIC Educational Resources Information Center

    Faigenbaum, Avery D.

    2001-01-01

    Provides an overview of the potential health benefits of strength training for children, discussing the role of strength training in preventing sports-related injuries and highlighting design considerations for such programs. The focus is on musculoskeletal adaptations to strength training that are observable in healthy children. Guidelines for…

  17. Strength Training for Young Athletes.

    ERIC Educational Resources Information Center

    Kraemer, William J.; Fleck, Steven J.

    This guide is designed to serve as a resource for developing strength training programs for children. Chapter 1 uses research findings to explain why strength training is appropriate for children. Chapter 2 explains some of the important physiological concepts involved in children's growth and development as they apply to developing strength

  18. A nonlinear criterion for triaxial strength of inherently anisotropic rocks

    NASA Astrophysics Data System (ADS)

    Singh, Mahendra; Samadhiya, N. K.; Kumar, Ajit; Kumar, Vivek; Singh, Bhawani

    2015-07-01

    Rocks encountered at many underground construction sites are laminated and exhibit direction-dependent strength behavior. It is also a well-established fact that the strength varies in a nonlinear manner with confining pressure. There is a need of strength criterion which could capture the nonlinearity as well as the anisotropy in the triaxial strength behavior of the rocks. It is essential that the criterion should be simple and must involve minimum testing to the extent possible. Further, the parameters of the criterion should have wide acceptability among the geotechnical fraternity. In the present study, a nonlinear strength criterion for transversely isotropic rocks is presented. Critical state concept Barton (Int J Rock Mech Mining Sci Geomech Abstr 13(9):255-279, 1976) has been used to define the curvature of the criterion. With a correctly defined curvature and starting from a reference point (UCS), it is possible to accurately assess the triaxial strength for given confining pressure. An experimental study conducted on triaxial strength behavior of three types of anisotropic rocks namely phyllite, slate and orthoquartzite has been discussed. A data base comprising more than 1140 triaxial tests conducted worldwide on anisotropic rocks has been compiled. Statistical evaluation of goodness of fit of the proposed criterion to the data base has been carried out. Further, the predictive capabilities of the proposed criterion have been evaluated by determining the error in estimation of triaxial strength if only few triaxial test data are available for determining the criterion parameters. The data base has also been back analyzed to assess the critical confining pressure for anisotropic rocks. Statistically, the critical confining pressure for anisotropic rocks can be taken nearly equal to 1.25 times the maximum UCS (obtained by applying load either parallel or perpendicular to planes of anisotropy). It is concluded that reasonable estimates of the triaxial strength of anisotropic rock can be made through the proposed criterion using minimum amount of triaxial test data available.

  19. Water's Hydrogen Bond Strength

    E-print Network

    Martin Chaplin

    2007-06-10

    Water is necessary both for the evolution of life and its continuance. It possesses particular properties that cannot be found in other materials and that are required for life-giving processes. These properties are brought about by the hydrogen bonded environment particularly evident in liquid water. Each liquid water molecule is involved in about four hydrogen bonds with strengths considerably less than covalent bonds but considerably greater than the natural thermal energy. These hydrogen bonds are roughly tetrahedrally arranged such that when strongly formed the local clustering expands, decreasing the density. Such low density structuring naturally occurs at low and supercooled temperatures and gives rise to many physical and chemical properties that evidence the particular uniqueness of liquid water. If aqueous hydrogen bonds were actually somewhat stronger then water would behave similar to a glass, whereas if they were weaker then water would be a gas and only exist as a liquid at sub-zero temperatures. The overall conclusion of this investigation is that water's hydrogen bond strength is poised centrally within a narrow window of its suitability for life.

  20. The fracture strength and frictional strength of Weber Sandstone

    USGS Publications Warehouse

    Byerlee, J.D.

    1975-01-01

    The fracture strength and frictional strength of Weber Sandstone have been measured as a function of confining pressure and pore pressure. Both the fracture strength and the frictional strength obey the law of effective stress, that is, the strength is determined not by the confining pressure alone but by the difference between the confining pressure and the pore pressure. The fracture strength of the rock varies by as much as 20 per cent depending on the cement between the grains, but the frictional strength is independent of lithology. Over the range 0 2 kb, ??=0??5 + 0??6??n. This relationship also holds for other rocks such as gabbro, dunite, serpentinite, granite and limestone. ?? 1975.

  1. Kinematic Rupture Process Of Karakocan-Elazig Earthquake, Eastern Turkey

    NASA Astrophysics Data System (ADS)

    Bekler, F. N.; Ozel, N. M.; Tanircan, G. B.

    2012-04-01

    An earthquake (Mw=5.9) hit Elazig in the eastern part of Turkey on March 8, 2010 at 02:32 (GMT). It is located midway between the provincial capital of Elaz?? and Bingöl with coordinates reported as 38o48.42N and 40o5.99E by Bogazici University Kandilli Observatory and Earthquake Research Institute (KOERI). Source characterization and slip history were estimated the main and four moderate size earthquake almost at the same location. The earthquake occurred at one of the tectonically very active East Anatolian Fault zone starts at the Karl?ova triple junction, where it meets the North Anatolian fault to the NE. Multi time-window linear waveform inversion technique (MTWIT) was applied to strong ground motion (SGM) data. Theoretical Green's functions between subfaults and stations were calculated by a Discrete Wave Number Method (DWNM) using 1-D velocity structure. Inversion technique used in this study yields a non unique solution. Therefore various rupture models have been tried until both observed and synthetic data were matched. Results show simple patterns in slip distributions. Maximum slip is 0.78 and seismic moment is 1.435E+25 dyne.cm from the kinematic rupture process of the strike slip faulting. In this study, we searched a stable 1-D crustal velocity model with low RMS misfit to construct the theoretical Green's function between each sub-fault and each station among the 4 different models. These are Preliminary Reference Earth Model (PREM; Dziewonski and Anderson, 1981), International Association of Seismology and the Physics of the Earth's Interior (IASP91) (Kennett and Engdahl, 1991), Kandilli Observatory and Earthquake Research Institute (KOERI) earthquake location model, explosion model (Gurbuz, 2004). We have collected previous studies Rebollar et al., (2001), Ichinose et al., (1997), Abdel-Fattah (2002), Somerville et al., (1999), Wells and Coppersmith (1994) on source information of moderate size earthquakes occurred worldwide and compared with our results. Results were compared with those of similar size earthquakes around the world and a new empirical relationship was proposed between seismic moment and rupture area. We expect our findings provide usefull information to resolving rupture mechanisms and triggering of the events in Eastern Anatoion Region. Key Words: Rupture Process, Elazig Earthquake, Eastern Turkey

  2. Blood flow characteristics in a terminal basilar tip aneurysm prior to its fatal rupture

    PubMed Central

    Sforza, D.M.; Putman, C.M.; Scrivano, E.; Lylyk, P.; Cebral, J.R.

    2010-01-01

    Background and Purpose The development and validation of methods to stratify the risk of rupture of cerebral aneurysms is highly desired since current treatment risks can exceed the natural risk of rupture. Because unruptured aneurysms are typically treated before they rupture, it is very difficult to connect the proposed risk indices to the rupture of an individual aneurysm. The purpose of this case study was to analyze the hemodynamic environment of a saccular aneurysm of the terminal morphology sub-type that was imaged just prior to its rupture and to test whether the hemodynamic characteristics would designate this particular aneurysm as at high risk. Methods A patient-specific computational fluid dynamics model was constructed from 3D rotational angiography images acquired just hours before the aneurysm ruptured. A pulsatile flow calculation was performed and hemodynamic characteristics previously connected to rupture were analyzed. Results It was found that the aneurysm had a concentrated inflow stream, small impingement region, complex intra-aneurysmal flow structure, asymmetric flow split from the parent vessel to the aneurysm and daughter branches, and high levels of aneurysmal wall shear stress near the impaction zone. Conclusions The hemodynamics characteristics observed in this aneurysm right before its rupture are consistent with previous studies correlating aneurysm rupture and hemodynamic patterns in saccular and terminal aneurysms. This study supports the notion that hemodynamic information may be used to help stratify the rupture risk of cerebral aneurysms. PMID:20150312

  3. Transverse and longitudinal tensile properties at 760 C of several oxide dispersion strengthened nickel-base alloys

    NASA Technical Reports Server (NTRS)

    Anglin, A. E., Jr.

    1979-01-01

    The transverse and longitudinal tensile properties of the oxide dispersion strengthened nickel-base alloys were determined at 760 C. The alloys with small amounts of gamma prime have strength levels suitable for turbine vane applications, while other highly alloyed, gamma prime strengthened superalloys have strengths typical of turbine blade materials. These alloys were produced by mechanical alloying and extrusion and the turbine blade alloys were also directionally recrystallized. Resultant grain aspect ratios varied from 1:1 to over 20:1. Longitudinal tensile strengths ranged from 285 to 1175 MPa, while longitudinal elongations were in excess of 4 percent for all alloys. Transverse tensile strengths were comparable to longitudinal strengths, but transverse ductility levels were generally less than 2 percent elongation. Tensile and yield strengths increased with increasing strain rate over the range 0.001 to 0.05 per second. Ductility in both orientations was not strain rate sensitive but could be related to grain size and grain aspect ratio.

  4. Splay fault surface rupture triggered by the 2010 Chile earthquake

    NASA Astrophysics Data System (ADS)

    Melnick, D.; Moreno, M.; Motagh, M.; Cisternas, M.

    2010-12-01

    Faults that splay from megathrusts have been imaged at several active plate boundaries and observed on exposed fossil sections. Due to their steep dip, slip along such structures triggered by a megathrust earthquake may enhance near-field tsunami waves and shorten arrival times. However, motion of splay faults and their role on seismotectonic segmentation has remained elusive due to their predominant offshore location and few historical accounts. Though splay fault slip has been inferred during the 2004 Sumatra and other events, surface ruptures triggered by the 1964 M9.2 Alaska earthquake have been the only documented so far. Here we use field, geodetic and InSAR data to document surface fault rupture and coastal tilting at Isla Santa Maria (ISM; 37S) during the M8.8 earthquake of February 27, 2010. We integrate the observed deformation with previous knowledge of the regional structure to propose triggering of a splay fault. ISM is 75 km inland from the trench, at the intersection of the Arauco Bay and Santa María fault systems (SMFS), both consisting of blind reverse faults that propagate folds. The SMFS is associated to a cluster of microseismicity extending from the plate interface at 15 km to 2 km depth. An offshore seismic reflection profile across this cluster images a main reverse fault with a flat-ramp-flat structure shortcutting to the footwall. The 2010 surface breaks extend across the entire northern part of the island for 900 m, divided in two domains of ENE-WSW oriented structures separated by an E-W striking transfer zone. Each domain consists of faults and fractures with en echelon patterns, with a maximum normal vertical displacement of 80 cm. The geometry of surface ruptures is consistent with dextral transtensional kinematics. We associate the surface breaks to transpressional growth of the fault-cored anticline northeast of ISM; transtension at the surface relates to fold bending. Surface rupture was accompanied by 1.6-2.2 m of coastal uplift and a northward tilt revealed by ALOS InSAR data, biomarkers, campaign GPS, and leveling of a benchmark. This pattern of tilting mimics that of emerged late Holocene beach ridges, and is rather associated to motion along the Arauco Bay fault. Both systems may have been triggered by the megathrust event. Alternatively, it could arise at the sharp edge of a patch of high megathrust slip. Prominent rush of fluids from the rupture started during the Maule earthquake and continued for weeks. A small lake adjacent to the rupture, dry during summer droughts, became filled by the offspring. The flat morphology leads to small drainage basins with barely sufficient water to supply inhabitants during dry summer months suggesting that fluids rose through the fault from deeper levels in the crust. The SMFS is associated to the position of a paleo backstop structure, which limited an older deformable domain from the stable continental framework. The SMFS branches upward near the updip limit of the seismogenic zone, where fluids are expelled from mineral transformations. The Maule earthquake may have released trapped fluids at depth, which migrated through the splay fault reducing its friction and facilitating fault slip and surface rupture.

  5. Development of high strength and high ductility nanostructured TWIP steel

    NASA Astrophysics Data System (ADS)

    Kou, Hong Ning

    Strength and ductility are two exclusive mechanical properties of structural materials. One challenge for material research is to develop bulk nanostructured metals with simultaneous high strength and good ductility. To meet this objective, steels with twinning induced plasticity (TWIP) effect are selected for surface mechanical attrition treatment (SMAT) in this study. Tensile tests reveal extremely high yield strength and simultaneously sufficient ductility in these SMATed TWIP steel samples. With the duration increase of SMAT, both yield strength and tensile strength firstly monotonically increase to a maximum value of 2.25GPa with 18% total elongation. However, further increase of SMAT duration results in decreases of both strength and elongation. The excellent ductility of coarse-grained TWIP steels is attributed to the instantaneous generation of deformation twins in tension. Based on this, an interesting hierarchically tertiary twinning system is revealed by TEM/HRTEM in SMATed samples, composed of multi-scale twins respectively produced by annealing treatment, SMAT and tensile deformation. On one hand, boundaries of hierarchical twins with different orientations form three-dimensional networks that restrict each other and act as strong barriers to dislocation motion, leading to ultrahigh strength. On the other hand, stress concentration is relieved due to deformation transfer caused by twinning from grain to grain, resulting in large plasticity. Therefore, the hierarchical twinning structure is regarded as the most effective element that induces both extraordinary ultrahigh strength and good elongation in SMATed TWIP. The stable austenite also contributes to the preservation of good ductility. Martensite is only observed in SMATed TWIP by longest SMAT duration. Another route of fabricating nanostructured TWIP is performed by combining SMAT and thermomechanical treatment. The interval heat treatment between double SMAT benefits the total elongation to over 50%, with 980 MPa yield strength. Nanograins are observed at 60mum depth, different from their usual emergence on top surface. Martensitic phase transformation is discovered. Most nanostructured SMATed TWIP samples demonstrate typical ductile fractures with large quantities of dimples in different sizes, following the same trend of gradient grains. Long SMAT duration produces slight brittle crack with tearing ribs. Microvoids coalescence with manganese carbides leads to final rupture.

  6. Rupture testing for the quality control of electrodeposited copper interconnections in high-speed, high-density circuits

    NASA Technical Reports Server (NTRS)

    Zakraysek, Louis

    1987-01-01

    Printed Wiring Multilayer Board (PWMLB) structures for high speed, high density circuits are prone to failure due to the microcracking of electrolytic copper interconnections. The failure can occur in the foil that makes up the inner layer traces or in the plated through holes (PTH) deposit that forms the layer to layer interconnections. It is shown that there are some distinctive differences in the quality of Type E copper and that these differences can be detected before its use in a PWMLB. It is suggested that the strength of some Type E copper can be very low when the material is hot and that it is the use of this poor quality material in a PWMLB that results in PTH and inner layer microcracking. Since the PWMLB failure in question are induced by a thermal stress, and since the poorer grades of Type E materials used in these structures are susceptible to premature failure under thermal stress, the use of elevated temperature rupture and creep rupture testing is proposed as a means for screening copper foil, or its PTH equivalent, in order to eliminate the problem of Type E copper microcracking in advanced PWMLBs.

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

    PubMed Central

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

    2015-01-01

    Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3MJ and a 6.3MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers. PMID:26230392

  8. Ability to perform a single heel-rise is significantly related to patient-reported outcome after Achilles tendon rupture.

    PubMed

    Olsson, N; Karlsson, J; Eriksson, B I; Brorsson, A; Lundberg, M; Silbernagel, K G

    2014-02-01

    This study evaluated the short-term recovery of function after an acute Achilles tendon rupture, measured by a single-legged heel-rise test, with main emphasis on the relation to the patient-reported outcomes and fear of physical activity and movement (kinesiophobia). Eighty-one patients treated surgically or non-surgically with early active rehabilitation after Achilles tendon rupture were included in the study. Patient's ability to perform a single-legged heel-rise, physical activity level, patient-reported symptoms, general health, and kinesiophobia was evaluated 12 weeks after the injury. The heel-rise test showed that 40 out of 81 (49%) patients were unable to perform a single heel-rise 12 weeks after the injury. We found that patients who were able to perform a heel-rise were significantly younger, more often of male gender, reported a lesser degree of symptoms, and also had a higher degree of physical activity at 12 weeks. There was also a significant negative correlation between kinesiophobia and all the patient-reported outcomes and the physical activity level. The heel-rise ability appears to be an important early achievement and reflects the general level of healing, which influences patient-reported outcome and physical activity. Future treatment protocols focusing on regaining strength early after the injury therefore seem to be of great importance. Kinesiophobia needs to be addressed early during the rehabilitation process. PMID:22716232

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

    PubMed

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

    2015-01-01

    Power transformer rupture and fire resulting from an arcing fault inside the tank usually leads to significant security risks and serious economic loss. In order to reveal the essence of tank deformation or explosion, this paper presents a 3-D numerical computational tool to simulate the structural dynamic behavior due to overpressure inside transformer tank. To illustrate the effectiveness of the proposed method, a 17.3 MJ and a 6.3 MJ arcing fault were simulated on a real full-scale 360MVA/220kV oil-immersed transformer model, respectively. By employing the finite element method, the transformer internal overpressure distribution, wave propagation and von-Mises stress were solved. The numerical results indicate that the increase of pressure and mechanical stress distribution are non-uniform and the stress tends to concentrate on connecting parts of the tank as the fault time evolves. Given this feature, it becomes possible to reduce the risk of transformer tank rupture through limiting the fault energy and enhancing the mechanical strength of the local stress concentrative areas. The theoretical model and numerical simulation method proposed in this paper can be used as a substitute for risky and costly field tests in fault overpressure analysis and tank mitigation design of transformers. PMID:26230392

  10. Gaussian discriminating strength

    NASA Astrophysics Data System (ADS)

    Rigovacca, L.; Farace, A.; De Pasquale, A.; Giovannetti, V.

    2015-10-01

    We present a quantifier of nonclassical correlations for bipartite, multimode Gaussian states. It is derived from the Discriminating Strength measure, introduced for finite dimensional systems in Farace et al., [New J. Phys. 16, 073010 (2014), 10.1088/1367-2630/16/7/073010]. As the latter the new measure exploits the quantum Chernoff bound to gauge the susceptibility of the composite system with respect to local perturbations induced by unitary gates extracted from a suitable set of allowed transformations (the latter being identified by posing some general requirements). Closed expressions are provided for the case of two-mode Gaussian states obtained by squeezing or by linearly mixing via a beam splitter a factorized two-mode thermal state. For these density matrices, we study how nonclassical correlations are related with the entanglement present in the system and with its total photon number.

  11. Strength in numbers.

    PubMed

    Lakkis, S

    1999-03-01

    A case study showing the attitudes and actions reinforcing discrimination against women's rights in Lebanon is presented. The study illustrates the way in which the public¿s views and the interests of families and local dignitaries can manipulate opinions. Organizations aimed at protecting women's rights have found strength in working together. The Lebanese League, an organization comprised of 17 women's and human rights associations, has established a center and a telephone hotline to encourage abused women to disclose and discuss their situation. The center provides support in the form of legal, psychological and medical assistance. Another organization working with the Lebanese League towards the same vision is the Lebanese Physically Handicapped Union. Efforts to lobby around a Lebanese legislation discriminating against women so far had no success, but all organizations involved are aware of the need to work through a range of interventions, and to take a long-term view, before they can count on any success. PMID:12295032

  12. [The strength of fragile].

    PubMed

    Lagrée, J

    2015-02-01

    Chronic disorder not only modifies the patient's health status; it affects the body relationship and its potential; it decreases its power to act, changes its relation to time, to its relatives, in shortcut it affects all dimensions of the relationship with oneself, with others, and the world. However, if we assume that a patient cannot be reduced to his/her illness but must always be treated with the respect of a person, we also understand how chronic and debilitating disease affects both freedom (or autonomy) and perfectibility (or creativity). By analyzing the different forms of freedom of the patient, this paper intends to rehabilitate the fragile own strength which is fortitude. It manifests itself in attitudes and virtues such as gentleness, patience, attention to the present, hope, power of thought. It also intends to show that it is supporting fragile and allowing them to develop their own way of acting and living as humanity became intelligent and creative. PMID:24721121

  13. Tensile and creep rupture properties of Co + Co{sub 3}AlC{sub 0.5} two-phase alloys

    SciTech Connect

    Ishibashi, R.; Nakamura, S.; Aono, Y.; Miura, S.; Mishima, Y.

    1999-07-01

    It is expected that the {kappa}-phase of the intermetallic compound Co{sub 3}AlC{sub 0.5} would strengthen Co-base alloys used at high temperatures like the {gamma}{prime}-phase of Ni-base superalloys. Tensile and creep rupture properties of Co+{kappa} two-phase alloys with {kappa}-phase volume fractions up to 0.75 were investigated. Alloy samples made by directional solidification casting were annealed at 1,573K for 3.6 ks and at 1,373K for 28.8 ks in vacuum, followed by Ar gas cooling. Tensile tests at RT and 1,073K and creep rupture tests at 1,089K under a stress of 172 MPa were conducted with the tensile axis parallel to the solidification direction. In alloys with low {kappa}-phase volume fraction, cuboidal {kappa}-precipitates with average particle diameters of 0.4 to 1.0 {micro}m were observed. They were coherent with the Co(fcc) matrix with misfits of about 3%. As the {kappa}-phase volume fraction increased, tensile strength also increased. The alloy with {kappa}-phase volume fraction of 0.4 had a 0.2% proof stress of 817 MPa, tensile strength of 1,047 MPa at RT, creep rupture life of 1.43 Ms, and tensile strain higher than 10%. These strengths are better than those of the conventional Co-base alloys. However, ductility of alloys with {kappa}-phase volume fraction larger than 0.4 decreased due to large eutectic and primary {kappa}-phase particles.

  14. Single-knob beam line for transverse emittance partitioning

    NASA Astrophysics Data System (ADS)

    Xiao, C.; Kester, O. K.; Groening, L.; Leibrock, H.; Maier, M.; Rottländer, P.

    2013-04-01

    Flat beams feature unequal emittances in the horizontal and vertical phase space. Such beams were created successfully in electron machines by applying effective stand-alone solenoid fringe fields in the electron gun. Extension of this method to ion beams was proposed conceptually. The present paper is on the decoupling capabilities of an ion beam emittance transfer line. The proposed beam line provides a single-knob tool to partition the horizontal and vertical rms emittances, while keeping the product of the two emittances constant as well as the transverse rms Twiss parameters (?x,y and ?x,y) in both planes. It is shown that this single knob is the solenoid field strength.

  15. Ferroelectric Cathodes in Transverse Magnetic Fields

    SciTech Connect

    Alexander Dunaevsky; Yevgeny Raitses; Nathaniel J. Fisch

    2002-07-29

    Experimental investigations of a planar ferroelectric cathode in a transverse magnetic field up to 3 kGs are presented. It is shown that the transverse magnetic field affects differently the operation of ferroelectric plasma cathodes in ''bright'' and ''dark'' modes in vacuum. In the ''bright'' mode, when the surface plasma is formed, the application of the transverse magnetic field leads to an increase of the surface plasma density. In the ''dark'' mode, the magnetic field inhibits the development of electron avalanches along the surface, as it does similarly in other kinds of surface discharges in the pre-breakdown mode.

  16. Transverse Emittance Reduction with Tapered Foil

    SciTech Connect

    Jiao, Yi; Chao, Alex; Cai, Yunhai; /SLAC

    2011-12-09

    The idea of reducing transverse emittance with tapered energy-loss foil is proposed by J.M. Peterson in 1980s and recently by B. Carlsten. In this paper, we present the physical model of tapered energy-loss foil and analyze the emittance reduction using the concept of eigen emittance. The study shows that, to reduce transverse emittance, one should collimate at least 4% of particles which has either much low energy or large transverse divergence. The multiple coulomb scattering is not trivial, leading to a limited emittance reduction ratio. Small transverse emittances are of essential importance for the accelerator facilities generating free electron lasers, especially in hard X-ray region. The idea of reducing transverse emittance with tapered energy-loss foil is recently proposed by B. Carlsten [1], and can be traced back to J.M. Peterson's work in 1980s [2]. Peterson illustrated that a transverse energy gradient can be produced with a tapered energy-loss foil which in turn leads to transverse emittance reduction, and also analyzed the emittance growth from the associated multiple coulomb scattering. However, what Peterson proposed was rather a conceptual than a practical design. In this paper, we build a more complete physical model of the tapered foil based on Ref. [2], including the analysis of the transverse emittance reduction using the concept of eigen emittance and confirming the results by various numerical simulations. The eigen emittance equals to the projected emittance when there is no cross correlation in beam's second order moments matrix [3]. To calculate the eigen emittances, it requires only to know the beam distribution at the foil exit. Thus, the analysis of emittance reduction and the optics design of the subsequent beam line section can be separated. In addition, we can combine the effects of multiple coulomb scattering and transverse energy gradient together in the beam matrix and analyze their net effect. We find that,when applied to an electron linac or electron beam line, the energy spread increase and angular growth due to multiple scattering are not trivial; as a result, the transverse emittance can only be reduced with a limited ratio, e.g. down to about 65% the original value. The contents of this paper are arranged as follows. In Sec. II, we build the physical model of the tapered foil, derive the transverse eigen emittance and discuss the emittance reduction criteria. In Sec. III, we implement numerical simulations to verify the physical model; and in Sec. IV, we present numerical experiments and subsequent beam line to remove the transverse energy gradient to demonstrate the applicability of such method. Conclusions are given in the last section.

  17. Two unusual case histories of brittle ruptures in fossil fuel boiler tubes

    SciTech Connect

    Port, R.D.

    1987-01-01

    The common causes of brittle rupture in boiler tubes, such as hydrogen damage, corrosion, fatigue, and creep rupture, have often been presented in the corrosion literature. Because ruptures by such modes are anticipated, appropriate remedial measures can be taken. However, when all anticipated problems have been addressed, the only problems remaining are those which are unanticipated. Examples of such unanticipated problems are presented here in a pair of case histories which trace the causes of disabling, brittle ruptures to their origins. In each case, an unforeseen condition or circumstance led to the failure. The first case involves what may be an unprecedented brittle rupture in tubes which had been deslagged through the use of shotguns. This failure is traced to liquid metal embrittlement. The second case concerns a massive tube rupture which is linked to a manufacturing defect, and secondary severe erosion of an adjacent tube.

  18. Time-resolved observation of thermally activated rupture of a capillary-condensed water nanobridge

    SciTech Connect

    Bak, Wan; Sung, Baekman; Kim, Jongwoo; Kwon, Soyoung; Kim, Bongsu; Jhe, Wonho

    2015-01-05

    The capillary-condensed liquid bridge is one of the most ubiquitous forms of liquid in nature and contributes significantly to adhesion and friction of biological molecules as well as microscopic objects. Despite its important role in nanoscience and technology, the rupture process of the bridge is not well understood and needs more experimental works. Here, we report real-time observation of rupture of a capillary-condensed water nanobridge in ambient condition. During slow and stepwise stretch of the nanobridge, we measured the activation time for rupture, or the latency time required for the bridge breakup. By statistical analysis of the time-resolved distribution of activation time, we show that rupture is a thermally activated stochastic process and follows the Poisson statistics. In particular, from the Arrhenius law that the rupture rate satisfies, we estimate the position-dependent activation energies for the capillary-bridge rupture.

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

    NASA Technical Reports Server (NTRS)

    Rubin, C. M.

    1996-01-01

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

  20. Contrasting décollement and prism properties over the Sumatra 2004-2005 earthquake rupture boundary.

    PubMed

    Dean, Simon M; McNeill, Lisa C; Henstock, Timothy J; Bull, Jonathan M; Gulick, Sean P S; Austin, James A; Bangs, Nathan L B; Djajadihardja, Yusuf S; Permana, Haryadi

    2010-07-01

    Styles of subduction zone deformation and earthquake rupture dynamics are strongly linked, jointly influencing hazard potential. Seismic reflection profiles across the trench west of Sumatra, Indonesia, show differences across the boundary between the major 2004 and 2005 plate interface earthquakes, which exhibited contrasting earthquake rupture and tsunami generation. In the southern part of the 2004 rupture, we interpret a negative-polarity sedimentary reflector approximately 500 meters above the subducting oceanic basement as the seaward extension of the plate interface. This predécollement reflector corresponds to unusual prism structure, morphology, and seismogenic behavior that are absent along the 2005 rupture zone. Although margins like the 2004 rupture zone are globally rare, our results suggest that sediment properties influence earthquake rupture, tsunami hazard, and prism development at subducting plate boundaries. PMID:20616276

  1. Time-resolved observation of thermally activated rupture of a capillary-condensed water nanobridge

    NASA Astrophysics Data System (ADS)

    Bak, Wan; Sung, Baekman; Kim, Jongwoo; Kwon, Soyoung; Kim, Bongsu; Jhe, Wonho

    2015-01-01

    The capillary-condensed liquid bridge is one of the most ubiquitous forms of liquid in nature and contributes significantly to adhesion and friction of biological molecules as well as microscopic objects. Despite its important role in nanoscience and technology, the rupture process of the bridge is not well understood and needs more experimental works. Here, we report real-time observation of rupture of a capillary-condensed water nanobridge in ambient condition. During slow and stepwise stretch of the nanobridge, we measured the activation time for rupture, or the latency time required for the bridge breakup. By statistical analysis of the time-resolved distribution of activation time, we show that rupture is a thermally activated stochastic process and follows the Poisson statistics. In particular, from the Arrhenius law that the rupture rate satisfies, we estimate the position-dependent activation energies for the capillary-bridge rupture.

  2. Guide to transverse projections and mass-constraining variables

    SciTech Connect

    Barr, A. J.; Khoo, T. J.; Lester, C. G.; Konar, P.; Kong, K.; Matchev, K. T.; Park, M.

    2011-11-01

    This paper seeks to demonstrate that many of the existing mass-measurement variables proposed for hadron colliders (m{sub T}, m{sub eff}, m{sub T2}, missing p-vector{sub T}, h{sub T}, {radical}(s-circumflex){sub min}, etc.) are far more closely related to each other than is widely appreciated, and indeed can all be viewed as a common mass-bound specialized for a variety of purposes. A consequence of this is that one may understand better the strengths and weaknesses of each variable, and the circumstances in which each can be used to best effect. In order to achieve this, we find it necessary first to revisit the seemingly empty and infertile wilderness populated by the subscript 'T' (as in 'pe{sub T}') in order to remind ourselves what this process of transversification actually means. We note that, far from being simple, transversification can mean quite different things to different people. Those readers who manage to battle through the barrage of transverse notation distinguishing 'T' from 'v' or or from 'o', and 'early projection' from 'late projection', will find their efforts rewarded towards the end of the paper with (i) a better understanding of how collider mass variables fit together, (ii) an appreciation of how these variables could be generalized to search for things more complicated than supersymmetry, (iii) will depart with an aversion to thoughtless or naieve use of the so-called 'transverse methods' of any of the popular computer Lorentz-vector libraries, and (iv) will take care in their subsequent papers to be explicit about which of the 61 identified variants of the 'transverse mass' they are employing.

  3. Guide to transverse projections and mass-constraining variables

    NASA Astrophysics Data System (ADS)

    Barr, A. J.; Khoo, T. J.; Konar, P.; Kong, K.; Lester, C. G.; Matchev, K. T.; Park, M.

    2011-11-01

    This paper seeks to demonstrate that many of the existing mass-measurement variables proposed for hadron colliders (mT, meff, mT2, missing p?T, hT, s^min?, etc.) are far more closely related to each other than is widely appreciated, and indeed can all be viewed as a common mass-bound specialized for a variety of purposes. A consequence of this is that one may understand better the strengths and weaknesses of each variable, and the circumstances in which each can be used to best effect. In order to achieve this, we find it necessary first to revisit the seemingly empty and infertile wilderness populated by the subscript “T” (as in “p?T”) in order to remind ourselves what this process of transversification actually means. We note that, far from being simple, transversification can mean quite different things to different people. Those readers who manage to battle through the barrage of transverse notation distinguishing “?” from “?” or from “?,” and “early projection” from “late projection,” will find their efforts rewarded towards the end of the paper with (i) a better understanding of how collider mass variables fit together, (ii) an appreciation of how these variables could be generalized to search for things more complicated than supersymmetry, (iii) will depart with an aversion to thoughtless or naïve use of the so-called transverse methods of any of the popular computer Lorentz-vector libraries, and (iv) will take care in their subsequent papers to be explicit about which of the 61 identified variants of the “transverse mass” they are employing.

  4. Stability and conductivity of self assembled wires in a transverse electric field

    PubMed Central

    Stephenson, C.; Hubler, A.

    2015-01-01

    Self assembling wire networks typically evolve to minimize the resistance across electrical contacts which are frequently used in a manner comparable to Hebbian learning. In this work, we demonstrate that electrical fields can also be used to cause an increase in the resistance of the wire network. We show that if such a wire is exposed to a transverse electric field, the wire is deformed in a way that depends on it’s tensile strength. We measure the wire resistance as a function of transverse field for several field strengths and show that by deforming the wire, the amplitude of the resulting shape can be modified in a controllable fashion. At a critical value of the transverse field, we show that the wire loses stability. At this point we observe thresholding behavior in that the resistance increases abruptly to a maximum value and the wire is destroyed. This thresholding behavior suggests that self assembled wires may be manipulated via an transverse electric field and demonstrates that a mechanism exists for the destruction of undesirable connections. PMID:26463476

  5. Stability and conductivity of self assembled wires in a transverse electric field

    NASA Astrophysics Data System (ADS)

    Stephenson, C.; Hubler, A.

    2015-10-01

    Self assembling wire networks typically evolve to minimize the resistance across electrical contacts which are frequently used in a manner comparable to Hebbian learning. In this work, we demonstrate that electrical fields can also be used to cause an increase in the resistance of the wire network. We show that if such a wire is exposed to a transverse electric field, the wire is deformed in a way that depends on it’s tensile strength. We measure the wire resistance as a function of transverse field for several field strengths and show that by deforming the wire, the amplitude of the resulting shape can be modified in a controllable fashion. At a critical value of the transverse field, we show that the wire loses stability. At this point we observe thresholding behavior in that the resistance increases abruptly to a maximum value and the wire is destroyed. This thresholding behavior suggests that self assembled wires may be manipulated via an transverse electric field and demonstrates that a mechanism exists for the destruction of undesirable connections.

  6. A Numerical Solution Routine for Investigating Oxidation-Induced Strength Degradation Mechanisms in SiC/SiC Composites

    NASA Technical Reports Server (NTRS)

    Sullivan, Roy M.

    2015-01-01

    The stress rupture strength of silicon carbide fiber-reinforced silicon carbide (SiCSiC) composites with a boron nitride (BN) fiber coating decreases with time within the intermediate temperature range of 700-950 C. Various theories have been proposed to explain the cause of the time dependent stress rupture strength. Some previous authors have suggested that the observed composite strength behavior is due to the inherent time dependent strength of the fibers, which is caused by the slow growth of flaws within the fibers. Flaw growth is supposedly enabled by oxidation of free carbon at the grain boundaries. The objective of this paper is to investigate the relative significance of the various theories for the time-dependent strength of SiCSiC composites. This is achieved through the development of a numerically-based progressive failure analysis routine and through the application of the routine to simulate the composite stress rupture tests. The progressive failure routine is a time marching routine with an iterative loop between a probability of fiber survival equation and a force equilibrium equation within each time step. Failure of the composite is assumed to initiate near a matrix crack and the progression of fiber failures occurs by global load sharing. The probability of survival equation is derived from consideration of the strength of ceramic fibers with randomly occurring and slow growing flaws as well as the mechanical interaction between the fibers and matrix near a matrix crack. The force equilibrium equation follows from the global load sharing presumption. The results of progressive failure analyses of the composite tests suggest that the relationship between time and stress-rupture strength is attributed almost entirely to the slow flaw growth within the fibers. Although other mechanisms may be present, they appear to have only a minor influence on the observed time dependent behavior. XXXX The time dependent strength of Hi-NicalonTMfiber reinforced composites has been shown to be largely due to the intrinsic time dependent strength of the fibers. Other mechanisms (e.g. fusing and embrittlement) may have a small effect at later times. center dotBest agreement with the measured time-to-failure versus composite stress was obtained with progressive failure analyses solutions using multiple matrix crack formulation and with a combination of shear stress values between 3.5 -5 MPaand fiber damage values of < 9%. center dotIf slow crack growth in fibers requires oxidation of inter-granular interface, what is the source of oxygen? Does it flow from the surrounding atmospheredown a matrix crack or is there enough present in the constituents? SiCfibers? BN fiber coating?

  7. Event-by-event fluctuations of transverse-momentum and multiparticle clusters in relativistic heavy-ion collisions

    E-print Network

    W. Florkowski; W. Broniowski; B. Hiller; P. Bozek

    2006-10-10

    We analyze the event-by-event fluctuations of mean transverse-momentum measured recently by the PHENIX and STAR Collaborations at RHIC. We argue that the observed scaling of strength of dynamical fluctuations with the inverse number of particles can be naturally explained by formation of multiparticle clusters.

  8. Influence of cold work level on the irradiation creep and creep rupture of titanium-modified austenitic stainless steels

    SciTech Connect

    Garner, F.A.; Hamilton, M.L.; Eiholzer, C.R.; Toloczko, M.B.; Kumar, A.S.

    1992-06-01

    A titanium-modified austenitic type stainless steel was tested at three cold work levels to determine its creep and creep rupture properties under both thermal aging and neutron irradiation conditions. Both the thermal and irradiation creep behavior exhibit a complex non-monotonic relationship with cold work level that reflects the competition between a number of stress-sensitive and temperature-dependent microstructural processes. Increasing the degree of cold work to 30% form the conventional 20% level was detrimental to its performance, especially for applications above 550{degrees}C. The 20% cold work level is preferable to the 10% level, in terms of both in- reactor creep rapture response and initial strength.

  9. Rupture de la rate au cours de l'accouchement: à propos d'un cas

    PubMed Central

    Elbahraoui, Houda; Bouziane, Hanane; Akrouch, Jamila; Lakhdar, Amina; Ferhati, Driss

    2011-01-01

    La rupture de rate est une extrême urgence chirurgicale abdominale qui met très rapidement en jeu le pronostic vital. Les étiologies fréquemment retrouvées sont les traumatismes abdominaux par contusions ou plaies pénétrantes. La survenue d'une rupture de rate au cours de l'accouchement est un événement rare. Nous rapportons dans cette observation le cas d'une rupture splénique suite à des expressions abdominales survenue au cours d'un accouchement dystocique. PMID:22355431

  10. The rupture process of the Manjil, Iran earthquake of 20 june 1990 and implications for intraplate strike-slip earthquakes

    USGS Publications Warehouse

    Choy, G.L.; Zednik, J.

    1997-01-01

    In terms of seismically radiated energy or moment release, the earthquake of 20 January 1990 in the Manjil Basin-Alborz Mountain region of Iran is the second largest strike-slip earthquake to have occurred in an intracontinental setting in the past decade. It caused enormous loss of life and the virtual destruction of several cities. Despite a very large meizoseismal area, the identification of the causative faults has been hampered by the lack of reliable earthquake locations and conflicting field reports of surface displacement. Using broadband data from global networks of digitally recording seismographs, we analyse broadband seismic waveforms to derive characteristics of the rupture process. Complexities in waveforms generated by the earthquake indicate that the main shock consisted of a tiny precursory subevent followed in the next 20 seconds by a series of four major subevents with depths ranging from 10 to 15 km. The focal mechanisms of the major subevents, which are predominantly strike-slip, have a common nodal plane striking about 285??-295??. Based on the coincidence of this strike with the dominant tectonic fabric of the region we presume that the EW striking planes are the fault planes. The first major subevent nucleated slightly south of the initial precursor. The second subevent occurred northwest of the initial precursor. The last two subevents moved progressively southeastward of the first subevent in a direction collinear with the predominant strike of the fault planes. The offsets in the relative locations and the temporal delays of the rupture subevents indicate heterogeneous distribution of fracture strength and the involvement of multiple faults. The spatial distribution of teleseismic aftershocks, which at first appears uncorrelated with meizoseismal contours, can be decomposed into stages. The initial activity, being within and on the periphery of the rupture zone, correlates in shape and length with meizoseismal lines. In the second stage of activity the aftershock zone expands and appears to cluster about the geomorphic and geologic features several tens of kilometres from the rupture zone. The activity is interpreted as a regional response to quasistatic stress migration along zones of tectonic weakness. The radiated energy of the main shock and the estimate of seismic moment yields an apparent stress of 20 bars. High apparent stress may be typical of strike slip earthquakes occurring in intracontinental environments undergoing continental collision.

  11. Premonitory activity, rupture speed, radiation pattern and energy budget during stick-slip experiment in Westerly granite

    NASA Astrophysics Data System (ADS)

    Schubnel, A.; Passelègue, F. X.; Nielsen, S. B.; Bhat, H.; Madariaga, R. I.

    2013-12-01

    Since the proposal by Brace and Byerlee [1966] that the mechanism of stick-slip is similar to earthquakes mechanics, many experimental studies have been conducted in order to improve the understanding of earthquakes. Here we report macroscopic stick-slip events in saw-cut Westerly granite samples deformed under controlled upper crustal stress conditions in the laboratory. Experiments were conducted under triaxial loading (?1>?2=?3) at confining pressures (?3) ranging from 10 to 100 MPa. The angle between the fault plane and the maximum stress (?1) was imposed to be equal to 30°. Usual a dual gain system, a high frequency acoustic monitoring array recorded particles acceleration during macroscopic stick-slip events and premonitory background microseismicity. Here, we show that the macroscopic friction coefficient of the fault plane continuously increases with normal stress. At low friction (?<0.6), no background seismicity is recorded. At higher friction however, premonitory activity is systematically observed. An abrupt increase is observed in the second prior to the main shock and the cumulative moment release rate of the premonitory follows Omori's law. These results suggest that the macroscopic friction also controls the intensity of the premonitory activity in our experiments. In these conditions, Passelègue et al. 2013 have shown that supershear ruptures were achievable, at high normal stress. Here, we show that the high frequency content of the particles acceleration spectra also increases with the initial normal stress. The appearance of a peak around 0.1 MHz corresponds to the propagation of a conic wavefront at supershear velocities. In addition, a second high frequency peak, centered around 0.3MHz, appears with increasing cumulative number of stick-slip events. This high frequency radiation could be related to the gouge production and off-fault damage during rupture propagation. For the first time, we also record the stress drop dynamically, and show that the dynamic stress drop, measured locally close to the fault plane, is almost total ?<0.15 in the breakdown zone, while the strength recovery to values of ?>0.4 takes a few tens of microseconds only. Our measurements are consistent with flash heating, while stress drops measured at higher normal stress generally reveal a second frictionnal drop, consistent with the onset of melting, which was confirmed by our post-mortem microstructural analysis. Relationships between initial friction, rupture velocities, high frequency radiation and stress drop suggest that at high normal stress (i.e. at supershear velocities), the rupture processes become more dispersive. This result seems in agreement with seismological observations

  12. Strain Measurement Using FBG on COPV in Stress Rupture Test

    NASA Technical Reports Server (NTRS)

    Banks, Curtis; Grant, Joseph

    2007-01-01

    White Sands Test Facility (WSTF) was requested to perform ambient temperature hydrostatic pressurization testing of a Space Transportation System (STS) 40-in. Kevlar Composite Overwrapped Pressure Vessel (COPV). The 40-in. vessel was of the same design and approximate age as the STS Main Propulsion System (MPS) and Orbiter Maneuvering System (OMS) vessels. The NASA Engineering Safety Center (NESC) assembled a team of experts and conducted an assessment that involved a review of national Kevlar COPY data. During the review, the STS COPVs were found to be beyond their original certification of ten years. The team observed that the likelihood of STS COPV Stress rupture, a catastrophic burst before leak failure mode, was greater than previously believed. Consequently, a detailed assessment of remaining stress rupture life became necessary. Prior to STS-114, a certification deviation was written for two flights of OV-103 (Discovery) and OV-104 (Atlantis) per rationale that was based on an extensive review of the Lawrence Livermore National Laboratories, COPV data, and revisions to the STS COPV stress levels. In order to obtain flight rationale to extend the certification deviation through the end of the Program, the Orbiter Project Office has directed an interagency COPV team to conduct further testing and analysis to investigate conservatism in the stress rupture model and evaluate material age degradation. Additional analysis of stress rupture life requires understanding the fiber stresses including stress that occurs due to thru-wall composite compression in COPV components. Data must be obtained at both zero gauge pressure (pre-stress) and at the component operating pressure so that this phenomenon can be properly evaluated. The zero gauge pressure stresses are predominantly a result of the autofrettage process used during vessel manufacture. Determining these pre-stresses and the constitutive behavior of the overwrap at pressure will provide necessary information to better predict the remaining life of the STS COPVs. The primary test objective is obtaining data to verify the hypothesis of a radially oriented thru-thickness stress-riser in the COPV composite whose magnitude is a function of the applied pressure and the load history. The anticipated load dependent response follows from the constitutive behavior of the composite overwrap so data to quantify its nonlinear and time dependent response will be sought. The objective of the Fiber Braggs Gratings (FBGs) were to advance the state-of-the-art by developing techniques using FBG sensors that are capable of assessing stress-rupture degradation in Kevlar COPVs in a health monitoring mode (1). Moreover, they sought to answer questions of how embedded sensors affect overall integrity of the structure. And lastly, they sought to provide an important link in the overall stress rupture study that will help close the loop on the COPV fabrication process. NDE inspection methods will be used from start to finish and FBG will be an integral link within the overall chain.

  13. A Simple Experiment to Demonstrate the Effects of Cracks on Materials Strength

    ERIC Educational Resources Information Center

    Sauls, Frederick C.

    2011-01-01

    A simple in-class experiment was designed to expose students to an aspect of materials science dealing with defects. Students break a series of paper strips to gauge the breaking strength. A precut transverse "crack" weakens the paper strip by a surprising amount. Adding a precut "crack stopper" greatly reduces the effect of the original "crack".…

  14. Fault Roughness Records Strength

    NASA Astrophysics Data System (ADS)

    Brodsky, E. E.; Candela, T.; Kirkpatrick, J. D.

    2014-12-01

    Fault roughness is commonly ~0.1-1% at the outcrop exposure scale. More mature faults are smoother than less mature ones, but the overall range of roughness is surprisingly limited which suggests dynamic control. In addition, the power spectra of many exposed fault surfaces follow a single power law over scales from millimeters to 10's of meters. This is another surprising observation as distinct structures such as slickenlines and mullions are clearly visible on the same surfaces at well-defined scales. We can reconcile both observations by suggesting that the roughness of fault surfaces is controlled by the maximum strain that can be supported elastically in the wallrock. If the fault surface topography requires more than 0.1-1% strain, it fails. Invoking wallrock strength explains two additional observations on the Corona Heights fault for which we have extensive roughness data. Firstly, the surface is isotropic below a scale of 30 microns and has grooves at larger scales. Samples from at least three other faults (Dixie Valley, Mount St. Helens and San Andreas) also are isotropic at scales below 10's of microns. If grooves can only persist when the walls of the grooves have a sufficiently low slope to maintain the shape, this scale of isotropy can be predicted based on the measured slip perpendicular roughness data. The observed 30 micron scale at Corona Heights is consistent with an elastic strain of 0.01 estimated from the observed slip perpendicular roughness with a Hurst exponent of 0.8. The second observation at Corona Heights is that slickenlines are not deflected around meter-scale mullions. Yielding of these mullions at centimeter to meter scale is predicted from the slip parallel roughness as measured here. The success of the strain criterion for Corona Heights supports it as the appropriate control on fault roughness. Micromechanically, the criterion implies that failure of the fault surface is a continual process during slip. Macroscopically, the fundamental nature of the control means that 0.1 to 1% roughness should be ubiquitous on faults and can generally be used for simulating ground motion. An important caveat is that the scale-dependence of strength may result in a difference in the yield criterion at large-scales. The commonly observed values of the Hurst exponent below 1 may capture this scale-dependence.

  15. Interleukin-6 as a Prognostic Biomarker in Ruptured Intracranial Aneurysms

    PubMed Central

    Kao, Hung-Wen; Kuo, Chen-Ling; Huang, Ching-Shan; Tseng, Wan-Min; Lin, Ching-Po

    2015-01-01

    Background Interleukin-6 (IL-6), a proinflammatory cytokine, was found to surge in the cerebral spinal fluid after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that the plasma level of IL-6 could be an independent biomarker in predicting clinical outcome of patients with ruptured intracranial aneurysm. Methods We prospectively included 53 consecutive patients treated with platinum coil embolization of the ruptured intracranial aneurysm. Plasma IL-6 levels were measured in the blood samples at the orifices of the aneurysms and from peripheral veins. The outcome measure was the modified Rankin Scale one month after SAH. Multiple logistic regression analyses were used to evaluate the associations between the plasma IL-6 levels and the neurological outcome. Results Significant risk factors for the poor outcome were old age, low Glasgow Coma Scale (GCS) on day 0, high Fisher grades, and high aneurysmal and venous IL-6 levels in univariate analyses. Aneurysmal IL-6 levels showed modest to moderate correlations with GCS on day 0, vasospasm grade and Fisher grade. A strong correlation was found between the aneurysmal and the corresponding venous IL-6 levels (? = 0.721; P<0.001). In the multiple logistic regression models, the poor 30-day mRS was significantly associated with high aneurysmal IL-6 level (OR, 17.97; 95% CI, 1.51–214.33; P = 0.022) and marginally associated with high venous IL-6 level (OR, 12.71; 95% CI, 0.90–180.35; P = 0.022) after adjusting for dichotomized age, GCS on day 0, and vasospasm and Fisher grades. Conclusions The plasma level of IL-6 is an independent prognostic biomarker that could be used to aid in the identification of patients at high-risk of poor neurological outcome after rupture of the intracranial aneurysm. PMID:26176774

  16. A rare case of oesophageal rupture: Boerhaave's syndrome

    PubMed Central

    2014-01-01

    A 70-year-old patient was referred to our emergency department with severe retrosternal pain after forceful vomiting. Computed tomography (CT) scan revealed a left-sided oesophageal rupture with accompanying pneumomediastinum and bilateral pleural effusions. Conservative treatment with cessation of oral intake, intravenous broad-spectrum antibiotics, parenteral fluids and nutrition and left sided tube thoracostomy was initiated initially. After 5 days, however, the patient deteriorated. Follow-up CT scan demonstrated a mediastinal fluid collection as well as loculated pleural empyema. Open thoracotomy with mediastinal debridement and pleural drainage was performed, after which he made a slow but full recovery. Spontaneous oesophageal rupture due to an abrupt rise in intraluminal pressure caused by vomiting is also known as Boerhaave's syndrome. It is a rare but potentially life-threatening condition. Many patients present with atypical symptoms, and therefore, physicians should have a high index of suspicion in any patient presenting with vomiting and retrosternal pain. When Boerhaave's syndrome is suspected, a CT scan of the thorax and upper abdomen should be performed since treatment depends on clinical and radiological findings. Conservative management (cessation of oral intake, nasogastric decompression, administration of intravenous fluids and parenteral nutrition, intravenous broad-spectrum antibiotics and proton pump inhibitors and tube thoracostomies) may only be considered in patients with a contained rupture without systematic symptoms of infection. In these patients, endoscopic bridging of the tear with a self-expandable stent is also an option. Primary surgical repair (either by thoracotomy or by video assisted thoracoscopy (VATS)) should be considered when patients present with sepsis and/or large non-contained leaks or with severe mediastinal decontamination. PMID:25364474

  17. Risk of rupture of unruptured cerebral aneurysms in elderly patients

    PubMed Central

    Date, Isao; Tokunaga, Koji; Tominari, Shinjiro; Nozaki, Kazuhiko; Shiokawa, Yoshiaki; Houkin, Kiyohiro; Murayama, Yuichi; Ishibashi, Toshihiro; Takao, Hiroyuki; Kimura, Toshikazu; Nakayama, Takeo; Morita, Akio

    2015-01-01

    Objectives: The aim of this study was to identify risk factors for rupture of unruptured cerebral aneurysms (UCAs) in elderly Japanese patients aged 70 years or older. Methods: The participants included all patients 70 years of age or older in 3 prospective studies in Japan (the Unruptured Cerebral Aneurysm Study of Japan [UCAS Japan], UCAS II, and the prospective study at the Jikei University School of Medicine). A total of 1,896 patients aged 70 years or older with 2,227 UCAs were investigated. The median and mean follow-up periods were 990 and 802.7 days, respectively. Results: The mean aneurysm size was 6.2 ± 3.9 mm. Sixty-eight patients (3.6%) experienced subarachnoid hemorrhage during the follow-up period. Multivariable analysis per patient revealed that in patients aged 80 years or older (hazard ratio [HR], 2.02; 95% confidence interval [CI], 1.16–3.49, p = 0.012), aneurysms 7 mm or larger (HR, 3.08; 95% CI, 1.35–7.03, p = 0.007 for 7–9 mm; HR, 7.82; 95% CI, 3.60–16.98, p < 0.001 for 10–24 mm; and HR, 43.31; 95% CI, 12.55–149.42, p < 0.001 for ?25 mm) and internal carotid–posterior communicating artery aneurysms (HR, 2.45; 95% CI, 1.23–4.88, p = 0.011) were independent predictors for UCA rupture in elderly patients. Conclusions: In our pooled analysis of prospective cohorts in Japan, patient age and aneurysm size and location were significant risk factors for UCA rupture in elderly patients. PMID:26511450

  18. Evaluation and establishment of a canine model of delayed splenic rupture using contrast-enhanced ultrasound.

    PubMed

    Tian, Jiangke; Xie, Xia; Lv, Faqin; Yu, Tengfei; Wu, Rong; Zhang, Xinghua; Wang, Dong; Tang, Jie

    2012-09-01

    The aim of the present study was to establish a canine model of delayed splenic rupture (DSR). A total of 15 mongrel dogs were anesthetized and laparotomized. The hematomas were observed following an injection of heparin. The hematomas were ruptured. The severity of the spleen rupture was evaluated and the intra-abdominal free liquid was measured. The splenic hematomas in the dogs continued to form and the hematoma area gradually increased. The hematomas were ruptured after impacting the abdominal wall. The spleens were damaged, and conventional ultrasonography showed intra-abdominal free liquid. These conditions were demonstrated via computed tomography scanning. A DSR canine model was established successfully. PMID:22710316

  19. Linear stability analysis of transverse dunes

    E-print Network

    Hygor P. M. Melo; Eric J. R. Parteli; José S. Andrade Jr; Hans J. Herrmann

    2012-02-16

    Sand-moving winds blowing from a constant direction in an area of high sand availability form transverse dunes, which have a fixed profile in the direction orthogonal to the wind. Here we show, by means of a linear stability analysis, that transverse dunes are intrinsically unstable. Any along-axis perturbation on a transverse dune amplify in the course of dune migration due to the combined effect of two main factors, namely: the lateral transport through avalanches along the dune's slip-face, and the scaling of dune migration velocity with the inverse of the dune height. Our calculations provide a quantitative explanation for recent observations from experiments and numerical simulations, which showed that transverse dunes moving on the bedrock cannot exist in a stable form and decay into a chain of crescent-shaped barchans.

  20. Linear stability analysis of transverse dunes

    E-print Network

    Melo, Hygor P M; Andrade, José S; Herrmann, Hans J

    2012-01-01

    Sand-moving winds blowing from a constant direction in an area of high sand availability form transverse dunes, which have a fixed profile in the direction orthogonal to the wind. Here we show, by means of a linear stability analysis, that transverse dunes are intrinsically unstable. Any along-axis perturbation on a transverse dune amplify in the course of dune migration due to the combined effect of two main factors, namely: the lateral transport through avalanches along the dune's slip-face, and the scaling of dune migration velocity with the inverse of the dune height. Our calculations provide a quantitative explanation for recent observations from experiments and numerical simulations, which showed that transverse dunes moving on the bedrock cannot exist in a stable form and decay into a chain of crescent-shaped barchans.