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Sample records for transverse rupture strength

  1. Prediction of creep-rupture life of unidirectional titanium matrix composites subjected to transverse loading

    SciTech Connect

    John, R.; Khobaib, M.; Smith, P.R.

    1996-10-01

    Titanium matrix composites (TMCs) incorporating unidirectional fiber reinforcement are considered as enabling materials technology for advanced engines which require high specific strength and elevated temperature capability. The resistance of unidirectional TMCs to deformation under longitudinally applied sustained loading at elevated temperatures has been well documented. Many investigators have shown that the primary weakness of the unidirectional TMC is its susceptibility to failure under very low transverse loads, especially under sustained loading. Hence, a reliable model is required to predict the creep-rupture life of TMCs subjected to different transverse stress levels over a wide range of temperatures. In this article, the authors propose a model to predict the creep-rupture life of unidirectional TMC subjected to transverse loading based on the creep-rupture life of unidirectional TMC subjected to transverse loading based on the creep-rupture behavior of the corresponding fiberless matrix. The model assumes that during transverse loading, the effective load-carrying matrix ligament along a row of fibers controls the creep-rupture strength and the fibers do not contribute to the creep resistance of the composite. The proposed model was verified using data obtained from different TMC fabricated using three matrix compositions, which exhibited distinctly different types of creep behavior. The results show that the creep-rupture life of the transverse TMC decreases linearly with increasing ratio of the fiber diameter to the ply thickness. The creep-rupture life is also predicted to be independent of fiber spacing along the length of the specimen.

  2. Influence of Diamond Particles Coated with TiO2 Film on Wettability of Vitrified Bond and Transverse Rupture Strength (TRS) of Vitrified Bond Composites

    NASA Astrophysics Data System (ADS)

    Song, Dongdong; Wan, Long; Liu, Xiaopan; Hu, Weida; Li, Jianwei

    2016-06-01

    TiO2 films were prepared on the surface of the diamond particles using a classical sol-gel method. The results showed that the TiO2 covered on the diamond surface as a rough and dense film with anatase phase, and tightly combined with the diamond substrates via the Ti-O-C bond. The initial oxidation temperature and compression strength of diamond were improved to 725 °C and 23.8 N with TiO2 film coated. TiO2 film increased the roughness of the diamond surface, promoted its mutual solubility, and formed the chemical bonding (Ti-O-Si) between the vitrified bond and the diamond. Therefore, the TiO2 film decreased the interface energy of the diamond, and promoted the wetting angle of vitrified bond with diamond to 36.7°. As a result, the TRS of vitrified bond diamond composites was increased to 76.3 MPa.

  3. Severe neonatal complication of transverse lie after preterm premature rupture of membranes.

    PubMed

    Van der Kaay, D C M; Horsch, S; Duvekot, J J

    2013-07-08

    Both transverse lie and preterm premature rupture of membranes (PPROM) are associated with neonatal morbidity and mortality. We present a neonate born at 29 weeks gestation with severe birth trauma after PPROM and transverse lie. The patient had extensive swelling and areas of desquamated and necrotic skin of the right lower limb. Neonatal compartment syndrome (NCS) was suspected. Perfusion of the limb improved after decompressing subcutaneous incisions. A fetus in transverse lie may be mechanically damaged in the case of PPROM, especially at an early gestational age. Early recognition is of great interest in the management and prognosis of NCS.

  4. 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.

  5. 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.

  6. 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.

  7. Self-healing slip pulses in dynamic rupture models due to velocity-dependent strength

    USGS Publications Warehouse

    Beeler, N.M.; Tullis, T.E.

    1996-01-01

    Seismological observations of short slip duration on faults (short rise time on seismograms) during earthquakes are not consistent with conventional crack models of dynamic rupture and fault slip. In these models, the leading edge of rupture stops only when a strong region is encountered, and slip at an interior point ceases only when waves from the stopped edge of slip propagate back to that point. In contrast, some seismological evidence suggests that the duration of slip is too short for waves to propagate from the nearest edge of the ruptured surface, perhaps even if the distance used is an asperity size instead of the entire rupture dimension. What controls slip duration, if not dimensions of the fault or of asperities? In this study, dynamic earthquake rupture and slip are represented by a propagating shear crack. For all propagating shear cracks, slip velocity is highest near the rupture front, and at a small distance behind the rupture front, the slip velocity decreases. As pointed out by Heaton (1990), if the crack obeys a negative slip-rate-dependent strength relation, the lower slip velocity behind the rupture front will lead to strengthening that further reduces the velocity, and under certain circumstances, healing of slip can occur. The boundary element method of Hamano (1974) is used in a program adapted from Andrews (1985) for numerical simulations of mode II rupture with two different velocity-dependent strength functions. For the first function, after a slip-weakening displacement, the crack follows an exponential velocity-weakening relation. The characteristic velocity V0 of the exponential determines the magnitude of the velocity-dependence at dynamic velocities. The velocity-dependence at high velocity is essentially zero when V0 is small and the resulting slip velocity distribution is similar to slip weakening. If V0 is larger, rupture propagation initially resembles slip-weakening, but spontaneous healing occurs behind the rupture front. The

  8. 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).

  9. 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.

  10. A comparative study of the stress-rupture lifetimes of high-strength carbon fibers

    NASA Astrophysics Data System (ADS)

    Grimes-Ledesma, Lorie

    Stress-rupture life is the time a composite can survive under load at an assigned risk level. The stress-rupture lifetimes of high-strength PAN-based carbon fibers are important to the development and use of lightweight composite structures such as composite overwrapped pressure vessels (COPVs). To quantify appropriate stress-rupture risk levels based on available models, quantification of single fiber variability and lifetime is necessary to understand the variability observed in larger composite structures. In the present work, three PAN-based carbon fibers commonly used in COPV technology were examined, Hexcel IM9, Toray T700, and Toray T1000. The diameter of each fiber type was quantified by measuring samples in the scanning electron microscope and failure loads were determined by performing tensile tests on single fibers. Weibull statistics were used to describe the results. Fractography was performed on IM9 and T1000 fibers after tensile failure. The fracture surfaces are consistent with crack growth from a volume or surface defect. Stress-rupture testing was completed at two stress levels at each fiber type, 97% and 93% of the mean fiber strength for each of the fiber types. The results indicate that differences in stress-rupture life performance exist between the three fiber types. Differences in stress ratio of between 5 and 10% were observed, which may translate to significant difference in stress-rupture life behavior for larger composite structures. The results indicate that a relationship may exist between strength and stress-rupture life. However, if this relationship exists, it is not a simple one, and the relationship is likely complicated by manufacturing.

  11. 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.

  12. The effect of the addition of different fibres on the transverse and impact strength of acrylic resin denture base material.

    PubMed

    Rahamneh, A; Jagger, D C; Harrison, A

    2003-06-01

    The aim of the present study was to investigate the effect of the addition of different types of fibres on the transverse and impact strength of acrylic resin denture base material. The addition of glass fibres (strand) and polyethylene fibres produced a non significant increase in the modulus of elasticity, compared with the control of conventional heat-cured acrylic resin. The addition of glass fibres (woven and strand), polyethylene and carbon fibres to acrylic resin produced a non significant increase in the modulus of rupture. The addition of carbon, glass (strand) and polyethylene fibres produced a significant increase in the impact strength. Within the limitations of this study the addition of silk fibres did not produce an improvement in the mechanical properties.

  13. 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

  14. Copper, Boron, and Cerium Additions in Type 347 Austenitic Steel to Improve Creep Rupture Strength

    NASA Astrophysics Data System (ADS)

    Laha, Kinkar; Kyono, J.; Shinya, Norio

    2012-04-01

    Type 347 austenitic stainless steel (18Cr-12Ni-Nb) was alloyed with copper (3 wt pct), boron (0.01 to 0.06 wt pct), and cerium (0.01 wt pct) with an aim to increase the creep rupture strength of the steel through the improved deformation and cavitation resistance. Short-term creep rupture strength was found to increase with the addition of copper in the 347 steel, but the long-term strength was inferior. Extensive creep cavitation deprived the steel of the beneficial effect of creep deformation resistance induced by nano-size copper particles. Boron and cerium additions in the copper-containing steel increased its creep rupture strength and ductility, which were more for higher boron content. Creep deformation, grain boundary sliding, and creep cavity nucleation and growth in the steel were found to be suppressed by microalloying the copper-containing steel with boron and cerium, and the suppression was more for higher boron content. An auger electron spectroscopic study revealed the segregation of boron instead of sulfur on the cavity surface of the boron- and cerium-microalloyed steel. Cerium acted as a scavenger for soluble sulfur in the steels through the precipitation of cerium sulfide (CeS). This inhibited the segregation of sulfur and facilitated the segregation of boron on cavity surface. Boron segregation on the nucleated cavity surface reduced its growth rate. Microalloying the copper-containing 347 steel with boron and cerium thus enabled to use the full extent of creep deformation resistance rendered by copper nano-size particle by increase in creep rupture strength and ductility.

  15. The Reinforcement Effect of Nano-Zirconia on the Transverse Strength of Repaired Acrylic Denture Base

    PubMed Central

    ArRejaie, Aws S.; Abdel-Halim, Mohamed Saber; Rahoma, Ahmed

    2016-01-01

    Objective. The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base. Materials and Methods. Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n = 10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P ≤ 0.05). Results. Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P ≤ 0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin. Conclusion. Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers. PMID:27366150

  16. Effects of coating with different ceromers on the impact strength, transverse strength and elastic modulus of polymethyl methacrylate.

    PubMed

    Gül, Esma Başak; Atala, Mustafa Hayati; Eşer, Bekir; Polat, Nilüfer Tülin; Asiltürk, Meltem; Gültek, Ahmet

    2015-01-01

    The aim of this study was to evaluate the mechanical properties of polymethyl methacrylate (PMMA) after coating with different ceromers. For transverse strength and modulus of elasticity tests, specimens of 65×10×2.5 mm dimensions were prepared (5 groups, n=10). For impact strength test, specimens of 60×7.5×4 mm dimensions were prepared (5 groups, n=10). Test group specimens were coated with one of four different types of ceromers, and specimens in the control group were not coated. After specimens were tested for transverse and impact strengths, the data were analyzed with Kruskal-Wallis and Conover post hoc tests (p<0.05). GLYMOTEOS-TiO2 and A174-TEOS significantly increased the transverse strength of PMMA. All ceromers caused a statistically significant increase in the elastic modulus of PMMA. While GLYMO-TEOS-ZrO2 significantly decreased the impact strength, the other ceromers did not cause any statistically significant difference in impact strength. Coating with ceromers substantially improved the mechanical properties of PMMA.

  17. Determination of transverse shear strength through torsion testing

    SciTech Connect

    Marcucelli, K.T.; Fish, J.C.

    1997-12-31

    The in-plane characterization of composite materials is, in general, well understood and widely utilized throughout the aerospace industry. However, the use of composites in structural elements such as fuselage frames and rotorcraft flexbeams place large out-of-plane or through-the-thickness stresses for which there is little data. Efforts to determine the interlaminar shear strength of laminated composites have been hampered due to the nonlinear behavior of test specimens and the limitations of current analysis tools. An inexpensive rectangular torsion test specimen was designed to determine the interlaminar shear strength, s{sub 23}, of composite materials. Six different layups were fabricated of AS4/2220-3 carbon/epoxy unidirectional tape and tested in pure torsion. All of the specimens failed abruptly with well-defined shear cracks and exhibited linear load-deflection behavior. A quasi-three-dimensional (Q-3-D) finite element analysis was conducted on each of the specimen configurations to determine the interlaminar shear stress at failure. From this analysis, s{sub 23} was found to be 107 MPa for this material.

  18. 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.

  19. 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.

  20. Time and temperature dependence on the flexural fatigue strength in the transverse direction of unidirectional CFRP

    NASA Astrophysics Data System (ADS)

    Nakada, Masakazu; Maeda, M.; Hirohata, T.; Morita, M.; Miyano, Y.

    1997-03-01

    A prediction method of fatigue strength of polymer composites for an arbitrary frequency, stress ratio and temperature was proposed. The method is based upon the four hypotheses, (A) same failure mechanism for static, creep and fatigue failure, (b) same time-temperature superposition principle for all failure strengths, (C) linear cumulative damage law for monotone loading and (D) linear dependence of fatigue strength upon stress ratio. Flexural static, creep and fatigue tests at various temperatures were conducted in the transverse direction of two kinds of unidirectional CFRP laminates, which are T300/2500 and T300/PEEK. The validity of the prediction method and the applicability of the hypotheses for the flexural fatigue strength in the transverse direction of unidirectional CFRP laminates were discussed.

  1. Improvement of Transverse Strength in Graphite-Aluminum Composites by High-Strength Surface Foils.

    DTIC Science & Technology

    1982-02-01

    purchased from Material Concepts Incorporated. The precursor wire had Union Carbide’s VSB-32 or VS0054 pitch mesophase graphite fibers in a matrix of...probably valid. The reason for the low strength of these plates, particularly G4407, is not known. Pitch fiber graphite-aluminum composites usually have

  2. The Role of Fault Strength Heterogeneities in Earthquake Sequences and Dynamic Earthquake Ruptures with Enhanced Co-Seismic Weakening

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Lapusta, N.

    2011-12-01

    Natural faults are characterized by geometric complexities, variations in hydraulic and frictional properties, and non-uniform prestress. In simulations of isolated dynamic ruptures, these heterogeneities are used to produce complex earthquake scenarios, and often fault prestress and frictional strength are assigned independently. However, simulations of multiple earthquake cycles (e.g., Lapusta and Liu, 2009) show that fault prestress and strength are physically related through stress redistribution due to prior slip. Considering the interplay of stress redistribution and fault strength heterogeneity is important for understanding earthquake cycle patterns and characteristics of dynamic ruptures. Here we study long-term slip on faults with large-scale heterogeneous fault strength due to non-uniform normal stress and/or frictional properties, which could be related to geometric and/or material complexity. Using BICycle algorithm (Lapusta and Liu, 2009, Noda and Lapusta, 2011), we simulate the entire earthquake cycles, including fully dynamic seismic rupture and aseismic tectonic loading, on faults governed by Dieterich-Ruina rate-and-state friction with enhanced co-seismic weakening due to flash heating and thermal pressurization. Initial shear stresses are pre-assigned and developed into physically-consistent distribution through multiple cycles. In our simulations, incorporation of enhanced co-seismic weakening generally results in events with larger slip and enables the fault to operate at lower average stress level. Increasing heat production, and hence larger co-seismic weakening at the places of higher normal confinement, tends to partially compensate for the effect of heterogeneous static strength. The sequences are characterized by occasional large fault-spanning seismic events and many smaller events that rupture across only part of the fault. Shear stresses evolve and redistribute on the entire fault during the major events, in accordance with the fault

  3. Time-Dependent Stress Rupture Strength Degradation of Hi-Nicalon Fiber-Reinforced Silicon Carbide Composites at Intermediate Temperatures

    NASA Technical Reports Server (NTRS)

    Sullivan, Roy M.

    2016-01-01

    The stress rupture strength of silicon carbide fiber-reinforced silicon carbide composites with a boron nitride fiber coating decreases with time within the intermediate temperature range of 700 to 950 degree Celsius. Various theories have been proposed to explain the cause of the time-dependent stress rupture strength. The objective of this paper is to investigate the relative significance of the various theories for the time-dependent strength of silicon carbide fiber-reinforced silicon carbide 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.

  4. 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.

  5. Effects on stress rupture life and tensile strength of tin additions to Inconel 718

    NASA Technical Reports Server (NTRS)

    Dreshfield, R. L.; Johnson, W.

    1982-01-01

    Because Inconel 718 represents a major use of columbium and a large potential source of columbium for aerospace alloys could be that of columbium derived from tin slags, the effects of tin additions to Inconel 718 at levels which might be typical of or exceed those anticipated if tin slag derived columbium were used as a melting stock were investigated. Tin was added to 15 pound Inconel 718 heats at levels varying from none added to approximately 10,000 ppm (1 wt%). Limited 1200 F stress rupture testing was performed at stresses from 68,000 to 115,000 psi and a few tensile tests were performed at room temperature, 800 and 1200 F. Additions of tin in excess of 800 ppm were detrimental to ductility and stress rupture life.

  6. 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

  7. Glass rupture disk

    DOEpatents

    Glass, S. Jill; Nicolaysen, Scott D.; Beauchamp, Edwin K.

    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.

  8. 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.

  9. Effects of structure on deformation and strength characteristics of transversely isotropic man-made geomaterials

    NASA Astrophysics Data System (ADS)

    Usoltseva, OM; Tsoi, PA; Semenov, VN

    2017-02-01

    The laboratory tests on uniaxial and triaxial (Karman scheme) compression of bedded specimens (made of equivalent man-made geomaterial, meta-siltstone and shale) has allowed deriving relations between the strength and deformation characteristics and the bedding angle of the specimens. The elasticity and strength are assessed in accordance with the theoretical model by Salamon–Tien and the Hoek–Brown failure criterion. For the bedded geomedia (man-made geomaterial), the Salamon–Tien model yields a satisfactory estimate of the elastic characteristics (elasticity modulus, Poisson’s ratio). Based on the use of the Hoek–Brown criterion, the authors have derived a strength parameter independent of the lateral pressure.

  10. Temperature Dependence on the Strength and Stress Rupture Behavior of a Carbon-Fiber Reinforced Silicon Carbide (C/SiC) Composite

    NASA Technical Reports Server (NTRS)

    Verrilli, Michael J.; Calomino, Anthony

    2002-01-01

    Tensile strengths and stress rupture lives of carbon-fiber reinforced silicon carbide (C/SiC) specimens were measured at 800 C and are compared to previously reported 1200 C data. All tests were conducted in an environmental chamber containing 1000 ppm of oxygen in argon. The average 800 C tensile strength of 610 MPa is 10% greater than at 1200 C. Average stress rupture lives at 800 C were 2.5 times longer than those obtained at 1200 C. The difference in the 800 and 1200 C lives is related to the oxidation rate of the reinforcing carbon fibers, which is the primary damage mode of C/SiC composites in oxygen-containing environments.

  11. Effect of the fiber-matrix interphase on the transverse tensile strength of the unidirectional composite material

    NASA Technical Reports Server (NTRS)

    Tsai, H. C.; Arocho, A. M.

    1992-01-01

    A simple one-dimensional fiber-matrix interphase model has been developed and analytical results obtained correlated well with available experimental data. It was found that by including the interphase between the fiber and matrix in the model, much better local stress results were obtained than with the model without the interphase. A more sophisticated two-dimensional micromechanical model, which included the interphase properties was also developed. Both one-dimensional and two-dimensional models were used to study the effect of the interphase properties on the local stresses at the fiber, interphase and matrix. From this study, it was found that interphase modulus and thickness have significant influence on the transverse tensile strength and mode of failure in fiber reinforced composites.

  12. Comparisons of 76Hz Transverse and Radial Magnetic Field Strength Components Received in Connecticut.

    DTIC Science & Technology

    1986-03-11

    Measurements Made in Connecticut During 1974, NUSC Technical Report 4927, Naval Underwater Systems Center, New London, CT, 1 October 1975. 4 . P. R. Bannister and...Connecticut Radial , lanetic Field Strength \\crsIis GMT, 24 and 25 April 1981 . - 290 Jei [ -- ,. 4 TR 7523 -150 -152 -154 0 0 4 /26/84 -156 0 0 -158 -148 -150...Received in Connecticut Peter R. Bannister Submarine Electromagnetic Systems Department DTIC ~PR1 4 11986L .-- aO?,f Naval Underwater Systems Center

  13. Three-Dimensional Gait Analysis Following Achilles Tendon Rupture With Nonsurgical Treatment Reveals Long-Term Deficiencies in Muscle Strength and Function

    PubMed Central

    Tengman, Tine; Riad, Jacques

    2013-01-01

    Background: Precise long-term assessment of movement and physical function following Achilles tendon rupture is required for the development and evaluation of treatment, including different regimens of physical therapy. Purpose: To assess intermediate-term (<10 years by conventional thinking) objective measures of physical function following Achilles tendon rupture treated nonsurgically and to compare these with self-reported measures of physical function. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Two to 5 years after Achilles tendon rupture, 9 women and 43 men (mean age, 49.2 years; range, 26-68 years) were assessed by physical examination, performance of 1-legged jumps, and 3-dimensional gait analysis (including calculation of muscle work). Self-reported scores for foot function (Achilles tendon rupture score) and level of physical activity were collected. Twenty age- and sex-matched controls were assessed in the same manner. Results: Physical examination of patients with the knee extended revealed 11.1° of dorsiflexion on the injured side and 9.2° on the uninjured side (P = .020), indicating gastrocnemius muscle lengthening. The 1-legged jump distance was shorter on the injured side (89.5 vs 96.2 cm; P < .001). Gait analysis showed higher peak dorsiflexion (14.3° vs 13.3°; P = .016) and lower concentric (positive) plantar flexor work (16.6 vs 19.9 J/kg; P = .001) in the ankle on the uninjured side. At the same time, eccentric (negative) dorsiflexor work was higher on the injured side (13.2 vs 11.9 J/kg; P = .010). Self-perceived foot function and physical activity were lower in patients than in healthy controls (mean Achilles tendon rupture score, 78.6 and 99.8, respectively). Conclusion: Nonsurgically treated patients with Achilles tendon rupture showed signs of both anatomic and functional lengthening of the tendon. Attenuated muscle strength and function were present during walking as long as 2 to 5 years after rupture, as

  14. Transverse carpal ligament: its effect on flexor tendon excursion, morphologic changes of the carpal canal, and on pinch and grip strengths after open carpal tunnel release.

    PubMed

    Netscher, D; Mosharrafa, A; Lee, M; Polsen, C; Choi, H; Steadman, A K; Thornby, J

    1997-09-01

    A three-part study is described that examines postoperative weakness after open carpal tunnel release and investigates the role of the transverse carpal ligament in the digital flexor pulley system. The effect of this ligament on flexor tendon excursion is evaluated in a cadaver study. Magnetic resonance imaging analysis is used to determine whether division of the transverse carpal ligament promotes volar migration of the median nerve and flexor tendons. Finally, the effects of ligament division and various methods of transverse carpal ligament reconstruction on the return of grip and pinch strengths after open carpal tunnel release are evaluated. The authors were able to determine that transverse carpal ligament reconstruction, particularly the transposition flap repair technique, after open carpal tunnel release confers a mechanical advantage and that the transverse carpal ligament is an important pulley for flexor tendon excursion. Based on the magnetic resonance imaging studies, volar displacement of carpal contents is reduced in patients undergoing transverse carpal ligament reconstruction by means of a transposition flap compared with those undergoing no ligament reconstruction and those undergoing reconstruction using the palmar aponeurosis. Postoperative grip and pinch strength values for the transposition flap repair group surpassed those of the other two groups at 12 weeks.

  15. Improved concept of lithospheric strength and earthquake activity at shallow depths based upon the fan-head dynamic shear rupture mechanism

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris G.; Randolph, Mark F.

    2016-01-01

    The typical depth-frequency distribution of earthquake hypocentres (DFDE) demonstrates that, below an upper cutoff, the earthquake frequency increases with depth up to a maximum value and then decreases and ceases at a lower cutoff. Such regular behaviour of earthquakes implies the existence of some fundamental mechanisms responsible for the distribution. Conventional models of lithospheric strength based upon the assumption that the frictional strength along pre-existing faults represents a lower limit on the rock shear strength do not provide any intrinsic logic for the observed DFDE. The paper shows that these models ignore the specific properties of intact hard rocks which can exhibit extremely low transient strength (significantly lower than the frictional strength) during failure under the high confining stresses corresponding to seismogenic depths. The low transient strength is provided by a recently identified fan-head shear rupture mechanism which can be initiated in intact rocks in the proximity of pre-existing faults. The low transient shear strength of intact rock determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The efficiency of the fan-mechanism within the seismogenic layer is variable, with maximum efficiency at the middle range between the upper and lower cutoffs, thus providing minimum transient strength of the lithosphere and maximum earthquake frequency at that depth. We believe that this intrinsic property of hard rocks is responsible for the observed DFDE. Importantly, the formation of new faults in intact rock generated by the fan-mechanism can be accompanied by very small stress-drops (similar to, or lower than, stress-drops for frictional stick-slip instability) combined with abnormally high energy release. The paper proposes an improved concept

  16. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    PubMed Central

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-01-01

    Background: Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Results: Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins. PMID:23946739

  17. Heat-to-Heat Variation in Creep Life and Fundamental Creep Rupture Strength of 18Cr-8Ni, 18Cr-12Ni-Mo, 18Cr-10Ni-Ti, and 18Cr-12Ni-Nb Stainless Steels

    NASA Astrophysics Data System (ADS)

    Abe, Fujio

    2016-09-01

    Metallurgical factors causing the heat-to-heat variation in time to rupture have been investigated for 300 series stainless steels for boiler and heat exchanger seamless tubes, 18Cr-8Ni (JIS SUS 304HTB), 18Cr-12Ni-Mo (JIS SUS 316HTB), 18Cr-10Ni-Ti (JIS SUS321 HTB), and 18Cr-12Ni-Nb (JIS SUS 347HTB), at 873 K to 1023 K (600 °C to 750 °C) using creep rupture data for nine heats of the respective steels in the NIMS Creep Data Sheets. The maximum time to rupture was 222,705.3 hours. The heat-to-heat variation in time to rupture of the 304HTB and 316HTB becomes more significant with longer test durations at times above ~10,000 hours at 973 K (700 °C) and reaches to about an order of magnitude difference between the strongest and weakest heats at 100,000 hours, whereas that of the 321HTB and 347HTB is very large of about an order of magnitude difference from a short time of ~100 hours to long times exceeding 100,000 hours at 873 K to 973 K (600 °C to 700 °C). The heat-to-heat variation in time to rupture is mainly explained by the effect of impurities: Al and Ti for the 304HTB and 316HTB, which reduces the concentration of dissolved nitrogen available for the creep strength by the formation of AlN and TiN during creep, and boron for the 347HTB, which enhances fine distributions of M23C6 carbides along grain boundaries. The heat-to-heat variation in time to rupture of the 321HTB is caused by the heat-to-heat variation in grain size, which is inversely proportional to the concentration of Ti. The fundamental creep rupture strength not influenced by impurities is estimated for the steels. The 100,000 hours-fundamental creep rupture strength of the 347HTB steel is lower than that of 304HTB and 316HTB at 873 K and 923 K (600 °C and 650 °C) because the slope of stress vs time to rupture curves is steeper in the 347HTB than in the 304HTB and 316HTB. The 100,000 hours-fundamental creep rupture strength of the 321HTB exhibits large variation depending on grain size.

  18. Magnetic Field Strength Dependence of Transverse Relaxation and Signal-to-Noise Ratio for Hyperpolarized Xenon-129 and Helium-3 Gas Magnetic Resonance Imaging of Lungs

    NASA Astrophysics Data System (ADS)

    Dominguez-Viqueira, William

    Magnetic resonance (MR) imaging with hyperpolarized noble gases (HNG), 3He or 129Xe, has become a promising approach for studying lung anatomy and function. Unlike conventional MR imaging, the magnetization in HNG MR is independent of the magnetic field strength. This means that no improvement in signal-to-noise ratio (SNR) is expected with increasing clinical field strength above ˜0.25T. Furthermore, it has been predicted that the SNR may decline at clinical field strength due to decreases in the apparent transverse relaxation time (T2*), caused by the increased magnetic susceptibility induced field gradients at the air-tissue interface. In this thesis the magnetic field strength dependence of T2* and SNR in HNG MR is investigated experimentally in rodent and human lungs. For rodent imaging, a novel broad-band (0.1-100MHz) variable field strength MR imaging system for rodents was built. This system permitted imaging of 129Xe, 3He and 1H at low magnetic field strengths (3-73.5mT) to experimentally investigate the field dependence of HNG imaging SNR in rodent lungs. In vivo 129Xe and 3He signals were acquired at 73.5mT and T 2* was estimated to be approximately 180+/-8 ms, in good agreement with previously reported values. At 73.5mT, image noise is dominated by losses originated from the radiofrequency (RF) coils. To address this issue, RF coils were built using different types of copper wire and compared in phantoms and in vivo in rat lungs using hyperpolarized 3He and 129Xe gas. An SNR improvement of up to 200% was obtained with Litz wire compared to conventional copper wire. This improvement demonstrated the feasibility of HNG lung imaging in rodents at 73.5mT with SNR comparable to that obtained at clinical field strengths. To verify the SNR field dependence in humans, hyperpolarized 3He lung imaging at two commonly used clinical field strengths (1.5T and 3T) was performed in the same volunteers and compared. No significant differences in SNR were obtained

  19. Rupture disc

    DOEpatents

    Newton, Robert G.

    1977-01-01

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

  20. 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…

  1. 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

  2. Ruptured eardrum

    MedlinePlus

    ... Avoid swimming or putting your head underneath the water. Your provider may prescribe antibiotics (oral or ear drops) to prevent or treat an infection. Repair of the eardrum might be needed for larger holes or ruptures or if the eardrum does not ...

  3. Complete Achilles tendon ruptures.

    PubMed

    Landvater, S J; Renström, P A

    1992-10-01

    Achilles tendon ruptures can be treated nonsurgically in the nonathletic or low-end recreational athletic patient, particularly those more than 50 years of age, provided the treating physician does not delay in the diagnosis and treatment (preferably less than 48 hrs and possibly less than 1 week). The patient should be advised of the higher incidence of re-rupture of the tendon when treated nonsurgically. Surgical treatment is recommended for patients who are young and athletic. This is particularly true because the major criticism of surgical treatment has been the complication rate, which has decreased to a low level and to a mild degree, usually not significantly affecting the repair over time. Surgical treatment in these individuals seems to be superior not only in regard to re-rupture but also in assuring the correct apposition of the tendon ends and in placing the necessary tension on the tendon to secure appropriate orientation of the collagen fibers. This in turn allows them to regain full strength, power, endurance, and an early return to sports. Surgery is also recommended for late diagnosed ruptures where there is significant lengthening of the tendon. Surgical technique should involve a medial incision to avoid the sural nerve, absorbable suture, and augmentation with fascia or tendon where there is a gap or late rupture. Postoperatively, the immobilization should be 7 to 10 days in a splint. A walking boot with early motion in plantar flexion or a short leg cast with the tendon under slight tension should thereafter be used for 4 to 5 weeks. An early and well-supervised rehabilitation program should be initiated to restore the patient to the preinjury activity level.

  4. Fault branching and rupture directivity

    NASA Astrophysics Data System (ADS)

    Fliss, Sonia; Bhat, Harsha S.; Dmowska, Renata; Rice, James R.

    2005-06-01

    Could the directivity of a complex earthquake be inferred from the ruptured fault branches it created? Typically, branches develop in forward orientation, making acute angles relative to the propagation direction. Direct backward branching of the same style as the main rupture (e.g., both right lateral) is disallowed by the stress field at the rupture front. Here we propose another mechanism of backward branching. In that mechanism, rupture stops along one fault strand, radiates stress to a neighboring strand, nucleates there, and develops bilaterally, generating a backward branch. Such makes diagnosing directivity of a past earthquake difficult without detailed knowledge of the branching process. As a field example, in the Landers 1992 earthquake, rupture stopped at the northern end of the Kickapoo fault, jumped onto the Homestead Valley fault, and developed bilaterally there, NNW to continue the main rupture but also SSE for 4 km forming a backward branch. We develop theoretical principles underlying such rupture transitions, partly from elastostatic stress analysis, and then simulate the Landers example numerically using a two-dimensional elastodynamic boundary integral equation formulation incorporating slip-weakening rupture. This reproduces the proposed backward branching mechanism based on realistic if simplified fault geometries, prestress orientation corresponding to the region, standard lab friction values for peak strength, and fracture energies characteristic of the Landers event. We also show that the seismic S ratio controls the jumpable distance and that curving of a fault toward its compressional side, like locally along the southeastern Homestead Valley fault, induces near-tip increase of compressive normal stress that slows rupture propagation.

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

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-06

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

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

    PubMed Central

    Polzer, Stanislav; Gasser, T. Christian

    2015-01-01

    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

  7. Transversity 2008

    NASA Astrophysics Data System (ADS)

    Giuseppe, Ciullo; Paolo, Lenisa; Marco, Contalbrigo; Delia, Hasch

    2009-04-01

    Purpose and status of the Italian transversity project / F. Bradamante -- Transversity asymmetries / D. Boer -- The transverse angular momentum sum rule / E. Leader -- Measurement of Collins and Sivers asymmetries at HERMES / L. L. Pappalardo (for the HERMES collaboration) -- Review of SSA results on deuteron at COMPASS / A. Richter (for the COMPASS collaboration) -- Single spin asymmetries on a transversely polarized proton target at COMPASS / S. Levorato (for the COMPASS collaboration) -- New preliminary results on the transversity distribution and the Collins fragmentation functions / M. Anselmino ... [et al.] -- Sivers effect in SIDIS pion and kaon production / M. Anselmino ... [et al.] -- Spin-orbit correlations / M. Burkardt -- Correlation functions in hard and (semi)-inclusive processes / M. Schlegel, S. Mei[symbol]ner and A. Metz -- Transversity via exclusive [pie symbol]-electroproduction / G. R. Goldstein, S. Liuti and S. Ahmad -- Estimate of the Sivers asymmetry at intermediate energies with rescattering extracted from exclusive processes / A. Bianconi -- Exclusively produced p[symbol] asymmetries on the deuteron and future GPD measurements at COMPASS / C. Schill (for the COMPASS collaboration) -- Transversity and transverse-momentum-dependent distribution measurements from PHENIX and BRAHMS / C. Aidala (for the PHENIX and BRAHMS collaborations) -- Sivers and Collins effects in polarized pp scattering processes / M. Anselmino ... [et al.] -- Sivers function in constituent quark models / S. Scopetta ... [et al.] -- Sivers, Boer-Mulders and transversity in Drell-Yan processes / M. Anselmino ... [et al.] -- TMDs and Drell-Yan experiments at Fermilab and J-PARC / J.-C. Peng -- Double polarisation observables at PAX / M. Nekipelov (for the PAX collaboration) -- Future Drell-Yan measurement @ COMPASS / M. Colantoni (for the COMPASS collaboration) -- Measurements of unpolarized azimuthal asymmetries at COMPASS / W. Käfer (for the COMPASS collaboration

  8. Mega-earthquakes rupture flat megathrusts.

    PubMed

    Bletery, Quentin; Thomas, Amanda M; Rempel, Alan W; Karlstrom, Leif; Sladen, Anthony; De Barros, Louis

    2016-11-25

    The 2004 Sumatra-Andaman and 2011 Tohoku-Oki earthquakes highlighted gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution: A fast convergence rate and young buoyant lithosphere are not required to produce mega-earthquakes. We calculated the curvature along the major subduction zones of the world, showing that mega-earthquakes preferentially rupture flat (low-curvature) interfaces. A simplified analytic model demonstrates that heterogeneity in shear strength increases with curvature. Shear strength on flat megathrusts is more homogeneous, and hence more likely to be exceeded simultaneously over large areas, than on highly curved faults.

  9. Ruptured abdominal aortic aneurysm.

    PubMed

    Sachs, T; Schermerhorn, M

    2010-06-01

    Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management.

  10. Bilateral Patellar Tendon Rupture

    DTIC Science & Technology

    2009-07-01

    within the tendon or systemic disorders such as lupus erythematosus , diabetes mellitus, chronic kidney disease, rheumatologic disease, and local or...factors for patellar tendon rupture include obesity, male gender, age 30-40, activities that increase patellar stress, systemic lupus erythematosus ...patellar tendon rupture is a rare occurrence usually associated with chronic degeneration of tendon fibers, use of steroids, or systemic illness. Our

  11. Fan-structure waves in shear ruptures

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  12. Biomechanical Rupture Risk Assessment

    PubMed Central

    2016-01-01

    Abdominal aortic aneurysm (AAA) rupture is a local event in the aneurysm wall that naturally demands tools to assess the risk for local wall rupture. Consequently, global parameters like the maximum diameter and its expansion over time can only give very rough risk indications; therefore, they frequently fail to predict individual risk for AAA rupture. In contrast, the Biomechanical Rupture Risk Assessment (BRRA) method investigates the wall’s risk for local rupture by quantitatively integrating many known AAA rupture risk factors like female sex, large relative expansion, intraluminal thrombus-related wall weakening, and high blood pressure. The BRRA method is almost 20 years old and has progressed considerably in recent years, it can now potentially enrich the diameter indication for AAA repair. The present paper reviews the current state of the BRRA method by summarizing its key underlying concepts (i.e., geometry modeling, biomechanical simulation, and result interpretation). Specifically, the validity of the underlying model assumptions is critically disused in relation to the intended simulation objective (i.e., a clinical AAA rupture risk assessment). Next, reported clinical BRRA validation studies are summarized, and their clinical relevance is reviewed. The BRRA method is a generic, biomechanics-based approach that provides several interfaces to incorporate information from different research disciplines. As an example, the final section of this review suggests integrating growth aspects to (potentially) further improve BRRA sensitivity and specificity. Despite the fact that no prospective validation studies are reported, a significant and still growing body of validation evidence suggests integrating the BRRA method into the clinical decision-making process (i.e., enriching diameter-based decision-making in AAA patient treatment). PMID:27757402

  13. 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.

  14. Modeling rupture segmentations on the Cascadia megathrust

    NASA Astrophysics Data System (ADS)

    Yang, H.; Liu, Y.; McGuire, J. J.

    2012-12-01

    The Cascadia subduction zone has produced a series of large to great earthquakes, most recently in 1700 AD. Paleoseismological studies of submarine turbidites suggest a significant difference in recurrence interval between Northern (~500 year) and Southern (~200-300 year) Cascadia. Whether future large ruptures are segmented is very important for estimating hazard in Pacific Northwest, but remains enigmatic from the interpretations of current locking maps. Our approach is to develop rupture scenarios of Cascadia earthquakes by performing numerical simulations using the finite element software, PyLith. Based on the USGS plate interface model of Cascadia, we have constructed a realistic three-dimensional subduction fault model that stretches from Northern California to Central Vancouver Island. We have performed a number of dynamic rupture simulations using a set of artificial friction parameters and uniform stress distributions on the fault governed by a slip-weakening friction law. Preliminary results show that ruptures have initiated from the nucleation zone with higher shear stress than the ambient fault and have propagated on the realistic three-dimensional fault surface. The increase of dip angle with depth has little effect on the rupture propagation because that is governed mostly by the fault strength. The along-strike bend of the fault beneath Washington state and Vancouver Island has not impeded the rupture propagation given the uniform fault strength. To estimate the possible rupture segmentation, we have converted a slip-deficit rate model derived from GPS data into stress change distributions on the fault assuming the entire slip deficit would be released in the next great earthquake. We are also constructing another initial stress map derived from tidal and leveling data, which shows a significant difference in the locking depth beneath Central Oregon. The other important variable, the spatial variation of frictional parameters, however, has to be

  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. Ruptured jejunal artery aneurysm

    PubMed Central

    Costa, Sílvia; Costa, Alexandre; Pereira, Tiago; Maciel, Jorge

    2013-01-01

    Visceral artery aneurysms (VAAs), unlike aortic aneurysms, are very rare, but are also a potentially lethal vascular disease. Jejunal artery aneurysms only account for less than 3% of VAAs, but have a 30% risk of rupture, with 20% death rate, presenting with only few and vague symptoms. We report the case of a 76-year-old man presenting at the emergency department (ED) with a crampy epigastric pain and vomiting. An ultrasound performed diagnosed free abdominal fluid and immediate CT scan diagnosed jejunal artery aneurysm spontaneously rupturing, followed by hypovolaemic shock. Emergent surgery was undertaken, and aneurysmectomy, followed by partial enterectomy with primary anastomosis were performed, because of segmentary jejunal ischaemia. The patient's recovery was unremarkable. High level of suspicion, rapid diagnosis capability and prompt surgical or endovascular intervention, as well as an effective teamwork in the ED are critical to avoid the devastating consequences of ruptured VAAs. PMID:23771962

  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.

  18. Ruptured intracranial dermoid cyst.

    PubMed

    Oursin, C; Wetzel, S G; Lyrer, P; Bächli, H; Stock, K W

    1999-09-01

    Intradural dermoids are rare congenital tumors representing approximately 0.05% of all intracranial lesions. These benign tumors have a typical appearance on CT and MR due to their lipid components. The complication caused by rupture are the spillage of the fatty material into the cerebrospinal fluid. We report a case of a ruptured dermoid cyst showing fat/fluid levels in both side ventricles and fatty material in the subarachnoid space on CT and MR-imaging and the follow-up over four years after incomplete resection of the tumor.

  19. Strong transverse fields in delta-spots

    NASA Technical Reports Server (NTRS)

    Zirin, Harold; Wang, Haimin

    1993-01-01

    Spectroscopic measurements of the strength and direction of transverse magnetic fields in six delta-spots are presented. The field direction is determined by the relative strength of the pi- and sigma-components at different polarizer orientations, and is, with one exception, parallel to the neutral line and as strong as the umbral field. Field strengths determined by line splitting are as high as 3980 G.

  20. Rupture, waves and earthquakes.

    PubMed

    Uenishi, Koji

    2017-01-01

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

  1. Rupture, waves and earthquakes

    NASA Astrophysics Data System (ADS)

    Uenishi, Koji

    2017-01-01

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

  2. Rupture of the plantar fascia.

    PubMed

    Pai, V S

    1996-01-01

    Rupture of the plantar fascia in athletes engaged in sports that require running and jumping has been reported. However, spontaneous degenerative rupture of the plantar fascia is not well documented in the literature. This paper reports a patient with degenerative rupture of the plantar fascia.

  3. Coupling geodynamic earthquake cycles and dynamic ruptures

    NASA Astrophysics Data System (ADS)

    van Zelst, Iris; van Dinther, Ylona; Gabriel, Alice-Agnes; Heuret, Arnauld

    2016-04-01

    Studying the seismicity in a subduction zone and its effects on tsunamis requires diverse modelling methods that span spatial and temporal scales. Hundreds of years are necessary to build the stresses and strengths on a fault, while consequent earthquake rupture propagation is determined by both these initial fault conditions and the feedback of seismic waves over periods of seconds up to minutes. This dynamic rupture displaces the sea floor, thereby causing tsunamis. The aim of the ASCETE (Advanced Simulations of Coupled Earthquake and Tsunami Events) project is to study all these aspects and their interactions. Here, we present preliminary results of the first aspects in this modelling chain: the coupling of a seismo-thermo-mechanical (STM) code to the dynamic rupture model SeisSol. STM models of earthquake cycles have the advantage of solving multiple earthquake events in a self-consistent manner concerning stress, strength and geometry. However, the drawback of these models is that they often lack in spatial or temporal resolution and do not include wave propagation. In contrast, dynamic rupture models solve for frictional failure coupled to seismic wave propagation. We use the software package SeisSol (www.seissol.org) based on an ADER-DG discretization allowing high-order accuracy in space and time as well as flexible tetrahedral meshing. However, such simulations require assumptions on the initial fault stresses and strengths and its geometry, which are hard to constrain due to the lack of near-field observations and the complexity of coseismic conditions. By adapting the geometry as well as the stress and strength properties of the self-consistently developing non-finite fault zones from the geodynamic models as initial conditions for the dynamic rupture models, the advantages of both methods are exploited and modelling results may be compared. Our results show that a dynamic rupture can be triggered spontaneously and that the propagating rupture is

  4. Brittle dynamic damage due to earthquake rupture

    NASA Astrophysics Data System (ADS)

    Bhat, Harsha; Thomas, Marion

    2016-04-01

    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 wide range of strain rates. We then implement this constitutive response to understand the role of dynamic brittle off-fault damage on earthquake ruptures. We show that off-fault damage plays an important role in asymmetry of rupture propagation and is a source of high-frequency ground motion in the near source region.

  5. Premature rupture of membranes.

    PubMed Central

    Poma, P. A.

    1996-01-01

    The management of patients with premature rupture of membranes has changed markedly in the past several years. The basis for this is a combination of a better understanding of newborn physiology, improved neonatal care, refinements in antibiotic therapy, and the widespread use of maternal and fetal monitoring. The best outcome for both mother and infant undoubtedly reflects data based on a combination of factors, among which are gestational age survival, evidence of fetal distress, presence or absence of labor and sepsis, and of course, the cervical condition as it is related to labor-readiness. An important recent advance is the recognition that an active observation management program is associated with less morbidity and mortality than the classic management course of delivery within 12 hours of membrane rupture. The fact that preterm premature rupture of membranes tends to recur in subsequent pregnancies offers an opportunity for prevention. Moreover, advances in perinatal and neonatal care will continue to improve the outcomes of these women and their children. PMID:8583489

  6. Rupture of thin films with resonant substrate patterning.

    PubMed

    Kao, Justin C-T; Golovin, Alexander A; Davis, Stephen H

    2006-11-15

    We study the stability and rupture of thin liquid films on patterned substrates. It is shown that striped patterning on a length scale comparable to that of the spinodal instability leads to a resonance effect and an imperfect bifurcation of equilibrium film shapes. Weakly nonlinear analysis gives predictions for film shapes, stability, growth rates, and rupture times, which are confirmed by numerical solution of the thin-film equation. Film behavior is qualitatively different in the resonant patterning regime, but with sufficiently large domains rupture occurs on a spinodal length scale regardless of patterning. Instabilities transverse to the patterning are examined and shown to behave similarly as disturbances to films on uniform substrates. We explain some previously reported effects in terms of the imperfect bifurcation.

  7. 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,...

  8. 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,...

  9. 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,...

  10. 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,...

  11. 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,...

  12. [Premonitory sign of myocardial rupture].

    PubMed

    Lauten, A; Dittrich, P

    1975-10-01

    It is reported on 14 cases in which a rupture of the myocardium occurred following a myocardial infarction. The moment of the appearance as well as anamnestic and clinical peculiarities are examined. As the only usable symptom of the rupture the symptomatology of the electromechanic dissociation must be taken into consideration. Finally it is referred to the on principle possible operative consequences of the rupture of the myocardium (oversewing or infarctetomy).

  13. 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.

  14. Slow rupture of polymer films

    NASA Astrophysics Data System (ADS)

    Kliakhandler, Igor

    2004-11-01

    Bursting of soap film is a fast and fascinating process. It turns out that certain polymer films rupture in a somewhat similar fashion, but much slower. The slowness of the process allows one to study the rupture of polymer films with details. The rupture process in Hele-Shaw-like fashion shows remarkable properties, and is a very simple system. It turns out that propagation speed of the rupture is a function of the film thickness, and rheologic properties of the polymer. Experimental results will be compared with theory, together with demonstration of the experiment.

  15. Nondestructive Evaluation and Monitoring Results from COPV Accelerated Stress Rupture Testing

    NASA Astrophysics Data System (ADS)

    Saulsberry, Regor L.; Greene, Nathanael J.; Banks, Curtis E.; Madaras, Eric I.; Waller, Jess M.; Forth, Scott C.; Russell, Rick W.

    2010-09-01

    To project objective is 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.

  16. 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.

  17. Transverse Microcracking in Celion 6000/PMR-15 Graphite-Polyimide

    DTIC Science & Technology

    1979-12-01

    strength of a ply is exceeded by the ply’s transverse stress.) The stress- and 83 Table 4. Predicted Transverse Residual Curing Stresses for [0/90]s Gr...strongly influences TVM density. 4. Laminate analysis using stress- and temperature-dependent material properties predicts that the residual curing stresses...Temperature and Curvature of a [03/903Js Lam’ na te 70 3 Material Property Polynomials for Celion 6000/PMR- 15 80 4 Predicted Transverse Residual

  18. Ruptured Intracranial Dermoid Cyst Associated with Rupture of Cerebral Aneurysm

    PubMed Central

    Kim, Ki Hong

    2011-01-01

    Many tumors have been reported to coexist with cerebral aneurysm. However, intracranial dermoid cysts associated with cerebral aneurysm are very rare. We report a case in which rupture of a cerebral aneurysm resulted in a ruptured dermoid cyst. We present this interesting case and review current literature about the relationship between tumors and aneurysm formation. PMID:22259693

  19. TRANSVERSITY SINGLE SPIN ASYMMETRIES.

    SciTech Connect

    BOER,D.

    2001-04-27

    The theoretical aspects of two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions, are reviewed. Issues of factorization, evolution and Sudakov factors for the relevant observables are discussed. These theoretical considerations pinpoint the most realistic scenarios towards measurements of transversity.

  20. 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 μ}ξ{sup μ} = 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.

  1. Stress-rupture behavior of small diameter polycrystalline alumina fibers

    NASA Technical Reports Server (NTRS)

    Yun, Hee Mann; Goldsby, Jon C.; Dicarlo, James A.

    1993-01-01

    Continuous length polycrystalline alumina fibers are candidates as reinforcement in high temperature composite materials. Interest therefore exists in characterizing the thermomechanical behavior of these materials, obtaining possible insights into underlying mechanisms, and understanding fiber performance under long term use. Results are reported on the time-temperature dependent strength behavior of Nextel 610 and Fiber FP alumina fibers with grain sizes of 100 and 300 nm, respectively. Below 1000 C and 100 hours, Nextel 610 with the smaller grain size had a greater fast fracture and rupture strength than Fiber FP. The time exponents for stress-rupture of these fibers were found to decrease from approximately 13 at 900 C to below 3 near 1050 C, suggesting a transition from slow crack growth to creep rupture as the controlling fracture mechanism. For both fiber types, an effective activation energy of 690 kJ/mol was measured for rupture. This allowed stress-rupture predictions to be made for extended times at use temperatures below 1000 C.

  2. 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.

  3. Spontaneous Rupture of Pyometra

    PubMed Central

    Mallah, Fatemeh; Eftekhar, Tahere; Naghavi-Behzad, Mohammad

    2013-01-01

    Spontaneous perforation is a very rare complication of pyometra. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and other causes of acute abdomen. In most cases, a correct and definite diagnosis can be made only by laparotomy. We report two cases of diffuse peritonitis caused by spontaneous perforated pyometra. The first case is a 78-year-old woman with abdominal pain for which laparotomy was performed because of suspected incarcerated hernia. The second case is a 61-year-old woman with abdominal pain for which laparotomy was performed because of symptoms of peritonitis. At laparotomy of both cases, 1 liter of pus with the source of uterine was found in the abdominal cavity. The ruptured uterine is also detected. More investigations revealed no malignancy as the reason of the pyometra. PMID:24024054

  4. 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.

  5. Rheumatoid flexor tenosynovitis and rupture.

    PubMed

    Ferlic, D C

    1996-08-01

    Rheumatoid flexor tenosynovitis at the wrist can cause locking, limitation of motion, nerve compression, and rupture of tendons. To prevent and treat these conditions, a flexor tenosynovectomy, combined with nerve decompression and tendon reconstruction as indicated, is necessary. If tendons are ruptured, the flexor pollicis longus and profundus to the index finger are most commonly affected. On the fingers flexor tenosynovitis can also cause locking, decrease in range of motion and rupture tendons. Flexor tenosynovitis of the fingers should be treated with decompression of the tendons health with preservation of the pulley system.

  6. Elbow tendinopathy and tendon ruptures: epicondylitis, biceps and triceps ruptures.

    PubMed

    Rineer, Craig A; Ruch, David S

    2009-03-01

    Lateral and medial epicondylitis are common causes of elbow pain in the general population, with the lateral variety being more common than the medial by a ratio reportedly ranging from 4:1 to 7:1. Initially thought to be an inflammatory condition, epicondylitis has ultimately been shown to result from tendinous microtearing followed by an incomplete reparative response. Numerous nonoperative and operative treatment options have been employed in the treatment of epicondylitis, without the emergence of a single, consistent, universally accepted treatment protocol. Tendon ruptures about the elbow are much less frequent, but result in more significant disability and loss of function. Distal biceps tendon ruptures typically occur in middle-aged males as a result of an event that causes a sudden, eccentric contraction of the biceps. Triceps tendon ruptures are exceedingly rare but usually have a similar etiology with a forceful eccentric contraction of the triceps that causes avulsion of the tendon from the olecranon. The diagnosis of these injuries is not always readily made. Complete ruptures of the biceps or triceps tendons have traditionally been treated surgically with good results. With regard to biceps ruptures, there continues to be debate about the best surgical approach, as well as the best method of fixation of tendon to bone. This article is not meant to be an exhaustive review of the broad topics of elbow tendinopathy and tendon ruptures, but rather is a review of recently published information on the topics that will assist the clinician in diagnosis and management of these conditions.

  7. 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.

  8. Advancements in identifying biomechanical determinants for abdominal aortic aneurysm rupture.

    PubMed

    Kontopodis, Nikolaos; Metaxa, Eleni; Papaharilaou, Yannis; Tavlas, Emmanouil; Tsetis, Dimitrios; Ioannou, Christos

    2015-02-01

    Abdominal aortic aneurysms are a common health problem and currently the need for surgical intervention is determined based on maximum diameter and growth rate criteria. Since these universal variables often fail to predict accurately every abdominal aortic aneurysms evolution, there is a considerable effort in the literature for other markers to be identified towards individualized rupture risk estimations and growth rate predictions. To this effort, biomechanical tools have been extensively used since abdominal aortic aneurysm rupture is in fact a material failure of the diseased arterial wall to compensate the stress acting on it. The peak wall stress, the role of the unique geometry of every individual abdominal aortic aneurysm as well as the mechanical properties and the local strength of the degenerated aneurysmal wall, all confer to rupture risk. In this review article, the assessment of these variables through mechanical testing, advanced imaging and computational modeling is reviewed and the clinical perspective is discussed.

  9. 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.

  10. Transverse spin and transverse momentum in scattering of plane waves.

    PubMed

    Saha, Sudipta; Singh, Ankit K; Ray, Subir K; Banerjee, Ayan; Gupta, Subhasish Dutta; Ghosh, Nirmalya

    2016-10-01

    We study the near field to the far field evolution of spin angular momentum (SAM) density and the Poynting vector of the scattered waves from spherical scatterers. The results show that at the near field, the SAM density and the Poynting vector are dominated by their transverse components. While the former (transverse SAM) is independent of the helicity of the incident circular polarization state, the latter (transverse Poynting vector) depends upon the polarization state. It is further demonstrated that the interference of the transverse electric and transverse magnetic scattering modes enhances both the magnitudes and the spatial extent of the transverse SAM and the transverse momentum components.

  11. Rupture of the triceps tendon associated with steroid injections.

    PubMed

    Stannard, J P; Bucknell, A L

    1993-01-01

    Rupture of the triceps mechanism is an uncommon injury that has been recognized with increasing frequency in recent years. It has been proposed that such injuries commonly accompany fractures of the radial head and must be actively evaluated in the presence of such a fracture. We present a unique case of isolated rupture of the triceps tendon in an athlete who was lifting weights. This case was complicated by a history of olecranon bursitis that had been treated with numerous local steroid injections, as well as a history of anabolic steroid abuse. Both systemic steroids and local injections may predispose tendons to rupture. Triceps tendon ruptures may result in uniformly good to excellent results if recognized and treated surgically. This case also serves as a reminder of the risks of treating inflamed tissues with local steroid injections, especially in strength athletes who place high demands on their musculoskeletal structures. Finally, this case documents a second case of triceps mechanism rupture in an athlete who has abused anabolic steroids. A study by Hunter et al. suggests that oral steroid abuse may be associated with detrimental effects on the mechanical properties of connective tissue, demonstrating another negative effect of anabolic steroid use in athletes.

  12. 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.

  13. Strength of Multiple Parallel Biological Bonds

    SciTech Connect

    Sulchek, T A; Friddle, R W; Noy, A

    2005-12-07

    Multivalent interactions play a critical role in a variety of biological processes on both molecular and cellular levels. We have used molecular force spectroscopy to investigate the strength of multiple parallel peptide-antibody bonds using a system that allowed us to determine the rupture forces and the number of ruptured bonds independently. In our experiments the interacting molecules were attached to the surfaces of the probe and sample of the atomic force microscope with flexible polymer tethers, and unique mechanical signature of the tethers determined the number of ruptured bonds. We show that the rupture forces increase with the number of interacting molecules and that the measured forces obey the predictions of a Markovian model for the strength of multiple parallel bonds. We also discuss the implications of our results to the interpretation of force spectroscopy measurements in multiple bond systems.

  14. 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

  15. Ruptures of the distal biceps tendon.

    PubMed

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon.

  16. Delayed diaphragmatic rupture presenting with acute gastric volvulus

    PubMed Central

    Macleod, R; Hollowood, A

    2014-01-01

    Gastric volvulus is a rare complication of diaphragmatic rupture. We report the case of an 82-year-old man who presented following an out-of-hospital cardiac arrest. Chest radiography and thoracic computed tomography revealed an acute gastric volvulus and a chronic diaphragmatic hernia containing transverse colon and abdominal viscera. He had complained of retching and associated epigastric pain prior to collapse, and had sustained a motorcycle accident approximately 60 years earlier. Insertion of a nasogastric tube was unsuccessful (completing Borchardt’s diagnostic triad) and his condition prevented both operative and endoscopic reduction of his volvulus. He died soon afterwards. PMID:25245717

  17. Low stress drop earthquakes in the rupture zone of the 1992 Nicaragua tsunami earthquake

    NASA Astrophysics Data System (ADS)

    Bilek, Susan L.; Rotman, Holly M. M.; Phillips, W. Scott

    2016-10-01

    Tsunami earthquakes, events that generate larger than expected tsunami and are deficient in high-frequency seismic radiation, are rare but hazardous to coastal populations. One model for these events is shallow rupture through low-strength materials. We calculate seismic moment, corner frequency, and stress drop for 216 earthquakes (2.1 < Mw < 4.7, November 2005 to June 2006) within and external to the 1992 Nicaragua tsunami earthquake rupture zone to test the hypothesis that differences in fault zone properties defined the limits of the 1992 tsunami rupture zone and continue to produce spatial variations in earthquake source properties. Mean stress drop of events within the rupture area is 1.2 MPa, and 5.5 MPa for events just outside of the rupture zone, with similar magnitude earthquakes in each group. Our results demonstrate different source parameter characteristics for microseismicity in the region of a past tsunami earthquake.

  18. A Molecular Dynamics Simulation of Vesicle Deformation and Rupture in Confined Poiseuille Flow

    NASA Astrophysics Data System (ADS)

    Harman, Alison

    Vesicles are simple structures, but display complex, non-linear dynamics in fluid flow. I investigate the deformation of nanometer-sized vesicles, both fully-inflated and those with excess area, as they travel in tightly confined capillaries. By varying both channel size and flow strength, I simulate vesicles as they transition from steady-state to unstable shapes, and then rupture in strong flow fields. By employing a molecular dynamics model of the vesicle, fluid, and capillary system one is able to rupture the lipid bilayer of these vesicles. This is unique in that most other numerical methods for modelling vesicles are unable to show rupture. The rupture of fully-inflated vesicles is applicable to drug delivery in which the release of the encapsulated medicine needs to be controlled. The deformation and rupture of vesicles with excess area could be applicable to red blood cells which have similar rheological properties.

  19. Spontaneous transverse colon volvulus

    PubMed Central

    Sana, Landolsi; Ali, Gassara; Kallel, Helmi; Amine, Baklouti; Ahmed, Saadaoui; Mohamed Ali, Elouer; Wajdi, Chaeib; Saber, Mannaï

    2013-01-01

    We report a case of spontaneous transverse colon volvulus in a young healthy woman. It constitutes an unusual case since it occurred in a young healthy woman with a subacute onset and no aetiological factor has been found. Its diagnosis is still challenging. Prompt recognition with emergency intervention constitutes the key to successful outcome. PMID:23785565

  20. Spontaneous transverse colon volvulus.

    PubMed

    Sana, Landolsi; Ali, Gassara; Kallel, Helmi; Amine, Baklouti; Ahmed, Saadaoui; Ali, Elouer Mohamed; Wajdi, Chaeib; Saber, Mannaï

    2013-01-01

    We report a case of spontaneous transverse colon volvulus in a young healthy woman. It constitutes an unusual case since it occurred in a young healthy woman with a subacute onset and no aetiological factor has been found. Its diagnosis is still challenging. Prompt recognition with emergency intervention constitutes the key to successful outcome.

  1. Digital transversal filter architecture

    NASA Astrophysics Data System (ADS)

    Greenberger, A. J.

    1985-01-01

    A fast and efficient architecture is described for the realization of a pipelined, fully parallel digital transversal filter in VLSI. The order of summation is changed such that no explicit multiplication is seen, gated accumulators are used, and the coefficients are circulated. Estimates for the number of transistors needed for a CMOS implementation are given.

  2. Rupture work of pendular bridges.

    PubMed

    de Boer, P C T; de Boer, M P

    2008-01-01

    Capillary bridging can generate substantial forces between solid surfaces. Impacted technologies and sciences include micro- and nanomachining, disk drive interfaces, scanning probe microscopy, biology, and granular mechanics. Existing calculations of the rupture work of capillary bridges do not consider the thermodynamics relating to the evaporation that can occur in the case of volatile liquids. Here, we show that the occurrence of evaporation decreases the rupture work by a factor of about 2. The decrease arises from heat taken from the surroundings that is converted into work. The treatment is based on a thermodynamic control-volume analysis of the pendular bridge geometry. We extend the mathematical formulation of Orr et al., solving the meniscus problem exactly for non-wetting surfaces. The extension provides analytical results for conditions at the rupture point and at a possible inflection point and for the rupture work. A simple equation (eq 32) is shown to fit the rupture work for the two cases over a meniscus curvature range of 3 orders of magnitude. Coefficients for the equation are given in tabular form for different contact angle pairs.

  3. [A case of strangulated congenital diaphragmatic hernia with necrosis and rupture of the colon and herniation into a left hemithorax in an adult (author's transl)].

    PubMed

    Sarris, M; Georgoulis, J; Gatos, M; Dariotis, A

    This is a case report of a successful repair of congenital diaphragmatic hernia in a 48 years old male that contained the transverse colon which was strangulated and ruptured in the left thoracic cavity. It was approached in two stages. First through a laparotomy the proximal part of the transverse colon was divided. The side going to the hernial sac was sutured and the proximal stump was anastomosed to the descending colon. In a second stage, two days later, through a felt thoracotomy the strangulated and ruptured colon was resected and the distal stump of the transverse colon was sutured and the hernia repaired.

  4. 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.

  5. 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

  6. Rupture-disk-less shock-tube with compression tube driven by free piston

    NASA Astrophysics Data System (ADS)

    Abe, T.; Ogura, E.; Sato, S.; Funabiki, K.

    A new technique is proposed for a shock tube driven by a freely moving piston. In a conventional free-piston-driven shock tube, a rupture disk is employed between the compression tube and the shock generation tube. In the present method, however, the conventional rupture disk is replaced by a newly developed fast action valve which is activated by the compressed gas generated in the compression tube. The present method enables us to generate high Mach number shock waves of arbitrary strength with good reproducibility. The performance of the new method is demonstrated experimentally. This also enables us to be carefree to scattering of fragments of the rupture disk.

  7. Self-Rupturing Hermetic Valve

    NASA Technical Reports Server (NTRS)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self

  8. Simultaneous bilateral patellar tendon rupture.

    PubMed

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

    2017-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  9. Tunable Microwave Transversal Filters.

    DTIC Science & Technology

    1984-05-01

    GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER AFOSR-TR. 84-0977 S4. TI TLE (and Subtitle) 5. TYP ?FE&T&PEO OEE U!NABLE MICROWAVE TRANSVERSAL FILTERS...this goal through magnetostatic waves MSW propagating at microwave frequency in magnetically biased, liquid phase epitaxial films of yttrium iron...garnet (YIG) grown on gadolinium gallium garnet (GGG). This technology has a number of advantages; low loss (greater than 30db/usec at xband), tunable by

  10. Transverse Spin Physics: Recent Developments

    SciTech Connect

    Yuan, Feng

    2008-12-10

    Transverse-spin physics has been very active and rapidly developing in the last few years. In this talk, I will briefly summarize recent theoretical developments, focusing on the associated QCD dynamics in transverse spin physics.

  11. Spontaneous Splenic Rupture in Melanoma

    PubMed Central

    Oryan, Ahmad; Davari, Aida; Daneshbod, Khosrow; Daneshbod, Yahya

    2014-01-01

    Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin) confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic) rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen. PMID:24795827

  12. 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.

  13. Dissipative Landau-Zener quantum dynamics with transversal and longitudinal noise

    NASA Astrophysics Data System (ADS)

    Javanbakht, S.; Nalbach, P.; Thorwart, M.

    2015-05-01

    We determine the Landau-Zener transition probability in a dissipative environment including both longitudinal as well as transversal quantum-mechanical noise originating from a single noise source. For this, we use the numerically exact quasiadiabatic path integral, as well as the approximative nonequilibrium Bloch equations. We find that transversal quantum noise in general influences the Landau-Zener probability much more strongly than longitudinal quantum noise does at a given temperature and system-bath coupling strength. In other words, transversal noise contributions become important even when the coupling strength of transversal noise is smaller than that of longitudinal noise. We furthermore reveal that transversal noise renormalizes the tunnel coupling independent of temperature. Finally, we show that the effect of mixed longitudinal and transversal noise originating from a single bath cannot be obtained from an incoherent sum of purely longitudinal and purely transversal noise.

  14. Mechanics of Multifault Earthquake Ruptures

    NASA Astrophysics Data System (ADS)

    Fletcher, J. M.; Oskin, M. E.; Teran, O.

    2015-12-01

    The 2010 El Mayor-Cucapah earthquake of magnitude Mw 7.2 produced the most complex rupture ever documented on the Pacific-North American plate margin, and the network of high- and low-angle faults activated in the event record systematic changes in kinematics with fault orientation. Individual faults have a broad and continuous spectrum of slip sense ranging from endmember dextral strike slip to normal slip, and even faults with thrust sense of dip slip were commonly observed in the aftershock sequence. Patterns of coseismic slip are consistent with three-dimensional constrictional strain and show that integrated transtensional shearing can be accommodated in a single earthquake. Stress inversions of coseismic surface rupture and aftershock focal mechanisms define two coaxial, but permuted stress states. The maximum (σ1) and intermediate (σ2) principal stresses are close in magnitude, but flip orientations due to topography- and density-controlled gradients in lithostatic load along the length of the rupture. Although most large earthquakes throughout the world activate slip on multiple faults, the mechanical conditions of their genesis remain poorly understood. Our work attempts to answer several key questions. 1) Why do complex fault systems exist? They must do something that simple, optimally-oriented fault systems cannot because the two types of faults are commonly located in close proximity. 2) How are faults with diverse orientations and slip senses prepared throughout the interseismic period to fail spontaneously together in a single earthquake? 3) Can a single stress state produce multi-fault failure? 4) Are variations in pore pressure, friction and cohesion required to produce simultaneous rupture? 5) How is the fabric of surface rupture affected by variations in orientation, kinematics, total geologic slip and fault zone architecture?

  15. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND 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...

  16. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND 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...

  17. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND 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...

  18. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND 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...

  19. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND 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...

  20. Dynamic Rupture Segmentation Along The Nankai Trough, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Hok, S.; Fukuyama, E.; Hashimoto, C.

    2010-12-01

    ). Inside the barrier, the fracture energy changes in regional scale, via a change of the critical slip distance scaling. The strength remains uniform along the interface. Asperities are produced by the initial stress distribution inferred from slip deficit. Using this model setting, we computed a few different spontaneous rupture scenarios, by changing only the location of rupture initiation. Remarkably, we could reproduce the segmentation of the rupture, as observed during the 1940’s sequence, provided that the rupture initiates close to the Kii peninsula barrier area. However, if the rupture initiate far from the Kii peninsula, close to Tokai or west of Muroto cape for instance, the rupture is more likely to break the full plate interface in a single rupture event, consistently with what has been observed in the past. The rupture segmentation appears to be a consequence of the friction properties off-Kii Peninsula, as well as the rupture initiation position. This work provides a reliable way to enlighten the conditional segmentation process, as a consequence of the earthquake dynamic rupture.

  1. 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.

  2. 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.

  3. 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

  4. [Transverse ectopic testis].

    PubMed

    Jouini, Riadh; Lefi, Mounir; Sami, Chelly; Manef, Gesmi; Mohsen, Belguith; Nouri, Abdellatif

    2002-09-01

    Transverse ectopic testis (TET) is a rare form of ectopic testis. The authors report the case of a 2-month-old infant presenting with right inguinoscrotal hernia and ectopic left testis with an impalpable testis. Opening of the hernia sac revealed two testes with two distally fused vasa deferentes. The contralateral testis was easily descended by translocation through the other inguinal canal. A favourable result was obtained with two testes situated in a normal position. In the light of this case, the authors emphasize the clinical and therapeutic features of this anomaly.

  5. Transverse axis fluid turbine

    SciTech Connect

    Brenneman, B.

    1983-11-15

    A fluid turbine, the rotation axis of which is transverse to the direction of fluid flow, has at least two blade assemblies mounted for rotation about the rotation axis. Each blade assembly includes a streamlined elongated blade having a span parallel to the rotation axis. Each blade is pivotable about a pivot axis parallel to and spaced from the rotation axis. The pivot axis is located circumferentially ahead of the blade center of pressure with respect to the direction of turbine rotation. Each blade assembly is so constructed that its center of mass is located either at its pivot axis or circumferentially at its pivot axis and radially outboard of its pivot axis.

  6. Transverse field focused system

    DOEpatents

    Anderson, Oscar A.

    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.

  7. Effect of Electron Beam Irradiation on Tensile Strength of Polypropylene

    NASA Astrophysics Data System (ADS)

    Yamada, Hiroshi; Ikeda, Masayuki; Shimbo, Minoru; Miyano, Yasushi

    In this paper, the effects of the intensity of electron beam and the variation with time after irradiation of electron beam on the tensile strength of the polypropylene (PP), which is widely used as medicine containers, were investigated. PP with and without colorants were used first and samples irradiated under various intensity of EB. A tensile test on the irradiated samples with elapsed time after the irradiation of the electron beam was carried out. The effects of those factors on the tensile strength were discussed. The following results were obtained (1) The tensile strength of PP decreased due to the influence of the electron beam irradiation, however the rate of the decrease in strength was small compared with the original one. Furthermore, the rate of the decrease in strength was very small owing to the variation with time after the EB irradiation. (2) The tensile rupture strength of PP increased and the rupture strain owing to the influence of the electron beam irradiation compared with the original one. In addition, these rupture strength increased and the rupture strain decreased along with time after the irradiation of the electron beam. (3) The tensile rupture strain energy of PP decreased owing to the influence of the electron beam irradiation compared with the original one. In addition, the strain energy decreases with time after the irradiation of the electron beam. Moreover, the strength characteristics of PP with colorants received greater influence of electron beam compared with the one without colorants.

  8. Energy Partition During In-plane Dynamic Rupture on a Frictional Interface

    NASA Astrophysics Data System (ADS)

    Needleman, A.; Shi, Z.; Ben-Zion, Y.

    2007-12-01

    We study properties of dynamic ruptures and the partition of energy between radiation and dissipative mechanisms using two-dimensional in-plane calculations with the finite element method. The model consists of two identical isotropic elastic media separated by an interface governed by rate- and state-dependent friction. Rupture is initiated by gradually overstressing a localized nucleation zone. Our simulations with model parameters representative of Homalite-100 indicate that different values of parameters controlling the velocity dependence of friction, the strength excess parameter and the length of the nucleation zone, can lead to the following four rupture modes: supershear crack-like rupture, subshear crack-like rupture, subshear single pulse and supershear train of pulses. High initial shear stress and weak velocity dependence of friction favor crack-like ruptures, while the opposite conditions favor the pulse mode. The rupture mode can switch from a subshear single pulse to a supershear train of pulses when the width of the nucleation zone increases. The elastic strain energy released over the same propagation distance by the different rupture modes has the following order: supershear crack, subshear crack, supershear train of pulses and subshear single pulse. The same order applies also to the ratio of kinetic energy (radiation) to total change of elastic energy for the different rupture modes. Decreasing the dynamic coefficient of friction increases the fraction of stored energy that is converted to kinetic energy. In the current study we use model parameters representative of rocks instead of Homalite-100, by modeling recent results of Kilgore et al. (2007) who measured and estimated various energy components in laboratory friction experiments with granite. We are also incorporating into the code ingredients that will allow us to study rupture properties and energy partition for cases with a bimaterial interface and dynamic generation of plastic strain

  9. High-strength iron aluminide alloys

    SciTech Connect

    McKamey, C.G.; Marrero-Santos, Y.; Maziasz, P.J.

    1995-06-01

    Past studies have shown that binary Fe{sub 3}Al possesses low creep-rupture strength compared to many other alloys, with creep-rupture lives of less than 5 h being reported for tests conducted at 593{degrees}C and 207 MPa. The combination of poor creep resistance and low room-temperature tensile density due to a susceptibility to environmentally-induced dynamic hydrogen embrittlement has limited use of these alloys for structural applications, despite their excellent corrosion properties. Improvements in room temperature tensile ductility have been realized mainly through alloying effects, changes in thermomechanical processing to control microstructure, and by control of the specimen`s surface condition. Ductilities of 10-20% and tensile yield strengths as high as 500 MPa have been reported. In terms of creep-rupture strength, small additions of Mo, Nb, and Zr have produced significant improvements, but at the expense of weldability and room-temperature tensile ductility. Recently an alloy containing these additions, designated FA-180, was shown to exhibit a creep-rupture life of over 2000 h after a heat treatment of 1 h at 1150{degrees}C. This study presents the results of creep-rupture tests at various test temperatures and stresses and discusses the results as part of our effort to understand the strengthening mechanisms involved with heat treatment at 1150{degrees}C.

  10. Transverse Compression of Tendons.

    PubMed

    Salisbury, S T Samuel; Buckley, C Paul; Zavatsky, Amy B

    2016-04-01

    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon.

  11. Magnetic field strength in solar coronal waveguides

    NASA Astrophysics Data System (ADS)

    Arregui, I.; Asensio Ramos, A.

    2017-03-01

    We applied Bayesian techniques to the problem of inferring the magnetic field strength in transversely oscillating solar coronal loops from observed periods and damping times. This was done by computing the marginal posterior probability density for parameters such as the waveguide density, the density contrast, the transverse inhomogeneity length scale, and the magnetic field strength under the assumption that the observed waves can be modelled as standing or propagating magnetohydrodynamic (MHD) kink modes of magnetic flux tubes. Our results indicate that the magnetic field strength can be inferred, even if the densities inside and outside the structure are largely unknown. When information on plasma density is available, the method enables to self-consistently include this knowledge to further constrain the inferred magnetic field strength. The inclusion of the observed oscillation damping enables to obtain information on the transverse density structuring and considerably alters the obtained posterior for the magnetic field strength.

  12. Unusual clinical presentation of a partial tibialis anterior rupture.

    PubMed

    Jellad, A; Salah, S; Bouaziz, M A; Bouzaouache, H; Ben Salah, Z

    2012-02-01

    Subcutaneous rupture of the tibialis anterior tendon is rare. Diagnosis is usually clear. The essential clinical symptoms are progressively: footdrop gait, loss of ankle flexion strength, ankle foot pain and claw toes. But the occurrence of an asymptomatic time period between the injury and the onset of clinical signs can make the diagnosis more difficult. MRI is the gold standard examination for tendons injuries and associated bone and joints damages. Surgical exploration confirms MRI findings. It constitutes the treatment of choice for tibialis anterior tendon rupture. Surgical or functional techniques used have an impact on the design of the rehabilitation program, essential step in the care management of these injuries. It avoids postoperative tendon adhesions and their functional consequences. We report here a case of a man presenting with footdrop gait as the only clinical symptom.

  13. Molecular dynamics of interface rupture

    NASA Technical Reports Server (NTRS)

    Koplik, Joel; Banavar, Jayanth R.

    1993-01-01

    Several situations have been studied in which a fluid-vapor or fluid-fluid interface ruptures, using molecular dynamics simulations of 3000 to 20,000 Lennard-Jones molecules in three dimensions. The cases studied are the Rayleigh instability of a liquid thread, the burst of a liquid drop immersed in a second liquid undergoing shear, and the rupture of a liquid sheet in an extensional flow. The late stages of the rupture process involve the gradual withdrawal of molecules from a thinning neck, or the appearance and growth of holes in a sheet. In all cases, it is found that despite the small size of the systems studied, tens of angstroms, the dynamics is in at least qualitative accord with the behavior expected from continuum calculations, and in some cases the agreement is to within tens of percent. Remarkably, this agreement occurs even though the Eulerian velocity and stress fields are essentially unmeasurable - dominated by thermal noise. The limitations and prospects for such molecular simulation techniques are assessed.

  14. Rupture of vertical soap films

    NASA Astrophysics Data System (ADS)

    Rio, Emmanuelle

    2014-11-01

    Soap films are ephemeral and fragile objects. They tend to thin under gravity, which gives rise to the fascinating variations of colors at their interfaces but leads systematically to rupture. Even a child can create, manipulate and admire soap films and bubbles. Nevertheless, the reason why it suddenly bursts remains a mystery although the soap chosen to stabilize the film as well as the humidity of the air seem very important. One difficulty to study the rupture of vertical soap films is to control the initial solution. To avoid this problem we choose to study the rupture during the generation of the film at a controlled velocity. We have built an experiment, in which we measure the maximum length of the film together with its lifetime. The generation of the film is due to the presence of a gradient of surface concentration of surfactants at the liquid/air interface. This leads to a Marangoni force directed toward the top of the film. The film is expected to burst only when its weight is not balanced anymore by this force. We will show that this leads to the surprising result that the thicker films have shorter lifetimes than the thinner ones. It is thus the ability of the interface to sustain a surface concentration gradient of surfactants which controls its stability.

  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. 3D Dynamic Rupture with Slip Reactivation and Ground Motion Simulations of the 2011 Mw 9.0 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Dalguer, Luis; Galvez, Percy

    2013-04-01

    Seismological, geodetic and tsunami observations, including kinematic source inversion and back-projection models of the giant megathrust 2011 Mw 9.0 Tohoku earthquake indicate that the earthquake featured complex rupture patterns, with multiple rupture fronts and rupture styles. The compilation of these studies reveals fundamentally three main feature: 1) spectacular large slip over 50m, 2) the existence of slip reactivation and 3) distinct regions of low and high frequency radiation. In this paper we investigate the possible mechanisms causing the slip reactivation. For this purpose we perform earthquakes dynamic rupture and strong ground motion simulations. We investigate two mechanisms as potential sources of slip reactivation: 1) The additional push to the earthquake rupture (slip reactivation) comes from the rupture front back propagating from the free-surface after rupturing the trench of the fault, a phenomena usually observed in dynamic rupture simulations of dipping faults (e.g. Dalguer et al. 2001). This mechanism produces smooth slip velocity reactivation with low frequency content. 2) Slip reactivation governed by the friction constitutive low (in the form given by Kanamori and Heaton, 2000) in which frictional strength drops initially to certain value, but then at large slips there is a second drop in frictional strength. The slip velocity caused by this mechanism is a sharp pulse capable to radiate stronger ground motion. Our simulations show that the second mechanism produces synthetic ground motion pattern along the Japanese cost of the Tohoku event consistent with the observed ground motion. In addition, the rupture pattern with slip reactivation is also consistent with kinematic source inversion models in which slip reactivation is observed. Therefore we propose that the slip reactivation observed in this earthquake is results of strong frictional strength drop, maybe caused by fault melting, pressurization, lubrication or other thermal weakening

  17. Ground motion hazard from supershear rupture

    USGS Publications Warehouse

    Andrews, D.J.

    2010-01-01

    An idealized rupture, propagating smoothly near a terminal rupture velocity, radiates energy that is focused into a beam. For rupture velocity less than the S-wave speed, radiated energy is concentrated in a beam of intense fault-normal velocity near the projection of the rupture trace. Although confined to a narrow range of azimuths, this beam diverges and attenuates. For rupture velocity greater than the S-wave speed, radiated energy is concentrated in Mach waves forming a pair of beams propagating obliquely away from the fault. These beams do not attenuate until diffraction becomes effective at large distance. Events with supershear and sub-Rayleigh rupture velocity are compared in 2D plane-strain calculations with equal stress drop, fracture energy, and rupture length; only static friction is changed to determine the rupture velocity. Peak velocity in the sub-Rayleigh case near the termination of rupture is larger than peak velocity in the Mach wave in the supershear case. The occurrence of supershear rupture propagation reduces the most intense peak ground velocity near the fault, but it increases peak velocity within a beam at greater distances. ?? 2010.

  18. Correlation of Shear Strength Between Longitudial and Transverse Specimens

    DTIC Science & Technology

    2012-05-17

    working on the capabilities and the  feasibility  of using titanium in the ship building  industry in the future.  All available specimens for this project...due to it being heat  treatable  and stronger than CP while retaining most of  the thermal properties.  The alloy’s chemical composition is formed by 6...observed during the analysis process, these are believed to explain  some of the misrepresenting data found in the later  stages  of the project. Values

  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. Electromechanical behavior of carbon nanotube fibers under transverse compression

    NASA Astrophysics Data System (ADS)

    Li, Yuanyuan; Lu, Weibang; Sockalingam, Subramani; Gu, Bohong; Sun, Baozhong; Gillespie, John W.; Chou, Tsu-Wei

    2017-03-01

    Although in most cases carbon nanotube (CNT) fibers experience axial stretch or compression, they can also be subjected to transverse compression, for example, under impact loading. In this paper, the electromechanical properties of both aerogel-spun and dry-spun CNT fibers under quasi-static transverse compressive loading are investigated for the first time. Transverse compression shows a nonlinear and inelastic behavior. The compressive modulus/strength of the aerogel-spun and dry-spun CNT fibers are about 0.21 GPa/0.796 GPa and 1.73 GPa/1.036 GPa, respectively. The electrical resistance goes through three stages during transverse compressive loading/unloading: initially it decreases, then it increases during the loading, and finally it decreases upon unloading. This study extends our knowledge of the overall properties of CNT fibers, and will be helpful in promoting their engineering applications.

  1. Broadband characterization of large subduction earthquakes through the combination of coherent rupture imaging and kinematic modeling

    NASA Astrophysics Data System (ADS)

    Dionicio, V.; Satriano, C.; Kiraly, E.; Vilotte, J.-P.; Bernard, P.

    2012-04-01

    In recent years the seismic observation has made a huge leap forward in terms of coverage and density of recording stations. This instrumental effort has fostered the development of new approaches to the study of the seismic rupture, which can potentially support and complement the classical finite source kinematic modeling. The availability of dense seismic arrays makes today possible to image the earthquake extended source through the coherent interferometry of the wave radiation emitted during the rupture propagation. One of the advantages of this approach is to deliver images of the source emissivity that do not need a-priori information on the rupture speed or on the fault geometry, while they can constrain these parameters for kinematic inversion. Moreover, coherent interferometry provides intrinsically high frequency images of the rupture, since it works at frequencies that are generally one or two order of magnitudes higher than those used for kinematic slip inversion. The combination and the joint interpretation of coherent imaging and finite source slip modeling opens up new perspectives in the study of the rupture processes, in relation to the geometry and the strength of the fault asperities. We effectively combined coherent rupture imaging and kinematic modeling for the study of the rupture process of two mega-thrust events: the 2010, Mw 8.8 Maule earthquake (Chile) and the 2011, Mw 9.0 Tohoku earthquake. The joint analysis of the rupture images shows, for both the earthquakes, distinctive patterns in the space-time distribution of high-frequency emissivity and low-frequency coherent slip. We interpret these results in terms of their implications on the geometry and mechanical properties of the subduction interface and the dynamical properties of the rupture.

  2. Nucleation and dynamic rupture on weakly stressed faults sustained by thermal pressurization

    NASA Astrophysics Data System (ADS)

    Schmitt, Stuart V.; Segall, Paul; Dunham, Eric M.

    2015-11-01

    Earthquake nucleation requires that the shear stress τ locally reaches a fault's static strength, fσeff, the product of the friction coefficient and effective normal stress. Once rupture initiates, shear heating-induced thermal pressurization can sustain rupture at much lower τ/σeff ratios, a stress condition believed to be the case during most earthquakes. This requires that earthquakes nucleate at heterogeneities. We model nucleation and dynamic rupture on faults in a 2-D elastic medium with rate/state friction and thermal pressurization, subjected to globally low τ but with local stress heterogeneities that permit nucleation. We examine end-member cases of either high-τ or low-σeff heterogeneities. We find that thermal pressurization can sustain slip at τ/σeff values as low as 0.13, compared to static friction of ˜0.7. Background τ (and, to lesser extent, heterogeneity width) controls whether ruptures arrest or are sustained, with extremely low values resulting in arrest. For a small range of background τ, sustained slip is pulse-like. Cessation of slip in a pulse tail can result from either diffusive restrengthening of σeff or a wave-mediated stopping phase that follows the rupture tip. Slightly larger background τ leads to sustained crack-like rupture. Thermal pressurization is stronger at high-τ heterogeneities, resulting in a lower background τ threshold for sustained rupture and potentially larger arresting ruptures. High-stress events also initiate with higher moment rate, although this may be difficult to observe in nature. For arresting ruptures, stress drops and the dependence of fracture energy on mean slip are both consistent with values inferred for small earthquakes.

  3. Complex rupture of the M6.3 2015 March 10 Bucaramanga earthquake: evidence of strong weakening process

    NASA Astrophysics Data System (ADS)

    Poli, P.; Prieto, G. A.; Yu, C. Q.; Florez, M.; Agurto-Detzel, H.; Mikesell, T. D.; Chen, G.; Dionicio, V.; Pedraza, P.

    2016-05-01

    We use seismic waves for a magnitude 6.3 intermediate-depth (160 km) earthquake in the Bucaramanga Nest, Colombia, to infer a complex rupture process with two distinct stages, characterized by different rupture velocities possibly controlled by the evolution of strength on the fault. Our integrated data processing permitted to precisely characterize the multistage rupture and the presence of a strong weakening event. The resulting seismic radiation is interpreted as resulting from an extreme weakening due to a cascading thermal shear runaway, with an initial inefficient radiation process followed by a fast and dynamic efficient rupture. Our results imply dynamic complexity of the seismic rupture deep inside the Earth, and may help to give some new insights about the physical mechanism of intermediate-depth earthquakes.

  4. 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.

  5. Ruptured jejunum following Heimlich maneuver.

    PubMed

    Razaboni, R M; Brathwaite, C E; Dwyer, W A

    1986-01-01

    The Heimlich maneuver, over time, has proved to be a useful resuscitative procedure in the management of cases with airway occlusion secondary to foreign body. Medical treatments, however, can have side effects, and this maneuver is no exception. A previously unreported complication is presented, that of jejunal rupture. The proper application of the maneuver minimizes the number of side effects; however, since they do occur, it is suggested that all persons subject to this maneuver be subsequently evaluated by a physician as soon after the incident as is practicable.

  6. General formulation of transverse hydrodynamics

    SciTech Connect

    Ryblewski, Radoslaw; Florkowski, Wojciech

    2008-06-15

    General formulation of hydrodynamics describing transversally thermalized matter created at the early stages of ultrarelativistic heavy-ion collisions is presented. Similarities and differences with the standard three-dimensionally thermalized relativistic hydrodynamics are discussed. The role of the conservation laws as well as the thermodynamic consistency of two-dimensional thermodynamic variables characterizing transversally thermalized matter is emphasized.

  7. Acute Pectoralis Major Rupture Captured on Video

    PubMed Central

    Valencia Mora, María

    2016-01-01

    Pectoralis major (PM) ruptures are uncommon injuries, although they are becoming more frequent. We report a case of a PM rupture in a young male who presented with axillar pain and absence of the anterior axillary fold after he perceived a snap while lifting 200 kg in the bench press. Diagnosis of PM rupture was suspected clinically and confirmed with imaging studies. The patient was treated surgically, reinserting the tendon to the humerus with suture anchors. One-year follow-up showed excellent results. The patient was recording his training on video, so we can observe in detail the most common mechanism of injury of PM rupture. PMID:27595030

  8. Creep-rupture tests of internally pressurized Rene 41 tubes

    NASA Technical Reports Server (NTRS)

    Gumto, K. H.; Weiss, B.

    1972-01-01

    Weld-drawn tubes of Rene 41 with 0.935 centimeter outside diameter and 0.064 centimeter wall thickness were tested to failure at temperatures from 1117 to 1233 K and internal helium pressures from 5.5 to 12.4 meganewtons per square meter. Lifetimes ranged from 5 to 2065 hours. The creep-rupture strength of the tubes was 50 percent lower than that of unwelded, thick sheet specimens, and 20 percent lower than that of unwelded, thin sheet specimens. Larson-Miller correlations and photomicrographs of some specimens are presented.

  9. Minimally invasive flexor hallucis longus transfer in management of acute achilles tendon rupture associated with tendinosis: a case report.

    PubMed

    Lui, Tun Hing

    2012-04-01

    Chronic tendinopathy is characterized by pain in the tendon, generally at the start and completion of exercise. However, tendinosis may lead to decreased blood flow, increased stiffness of the tendon and reduced tensile strength, and predispose to rupture. Operative treatment is indicated to restore the function of the Achilles tendon and alleviate the prerupture heel cord pain. A case of acute Achilles tendon rupture with extensive tendinosis that was successfully treated with minimally invasive flexor hallucis longus transfer is reported.

  10. 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.

  11. 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.

  12. Fan-head shear rupture mechanism as a source of off-fault tensile cracking

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    This presentation discusses the role of a recently identified fan-head shear rupture mechanism [1] in the creation of off-fault tensile cracks observed in earthquake laboratory experiments conducted on brittle photoelastic specimens [2,3]. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength) and self-sustaining tensile stress intensification along one side of the interface. The variation of tensile stress within the fan-head zone is like this: it increases with distance from the fracture tip up to a maximum value and then decreases. For the initial formation of the fan-head high local stresses corresponding to the fracture strength should be applied in a small area, however after completions of the fan-head it can propagate dynamically through the material at low shear stresses (even below the frictional strength). The fan-mechanism allows explaining all unique features associated with the off-fault cracking process observed in photoelastic experiments [2,3]. In these experiments spontaneous shear ruptures were nucleated in a bonded, precut, inclined and pre-stressed interface by producing a local pressure pulse in a small area. Isochromatic fringe patterns around a shear rupture propagating along bonded interface indicate the following features of the off-fault tensile crack development: tensile cracks nucleate and grow periodically along one side of the interface at a roughly constant angle (about 80 degrees) relative to the shear rupture interface; the tensile crack nucleation takes place some distance behind the rupture tip; with distance from the point of nucleation tensile cracks grow up to a certain length within the rupture head zone

  13. Formability Studies on Transverse Tailor Welded Blanks

    NASA Astrophysics Data System (ADS)

    Bhaskar, V. Vijay; Narasimhan, K.

    2005-08-01

    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.

  14. Spontaneous diaphragm rupture associated with vaginal delivery.

    PubMed

    Hamaji, Masatsugu; Burt, Bryan M; Ali, Syed Osman; Cohen, Daniel M

    2013-08-01

    Spontaneous rupture of the diaphragm associated with vaginal delivery is a rare occurrence, but has high rates of morbidity and mortality. Herein, we present a first uncomplicated case of spontaneous rupture of the diaphragm associated with vaginal delivery, which was treated successfully with surgery via a thoracotomy.

  15. Uterine rupture. A seat belt hazard.

    PubMed

    van Enk, A; van Zwam, W

    1994-05-01

    A case is described of a uterine rupture resulting from a car accident occurring in a woman who was wearing a seat belt as generally recommended. The rupture was initially not recognised and only became apparent after attempts to induce labor which led to expulsion of the fetus into the abdominal cavity.

  16. Fractal avalanche ruptures in biological membranes

    NASA Astrophysics Data System (ADS)

    Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

    2010-11-01

    Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

  17. Urgent arterial embolization of ruptured renal angiomyolipoma

    PubMed Central

    Yilmaz, Feyza

    2015-01-01

    The most undesired complication of renal angiomyolipoma (AML) is bleeding. Because of tumor rupture, the bleeding can spread to the retroperitoneal field and can be severe enough to be life threatening. We report a case of retroperitoneal hemorrhage caused by a ruptured AML that was successfully treated with transarterial embolization with N-butyl cyanoacrylate. PMID:28352700

  18. What does the transverse carpal ligament contribute to carpal stability?

    PubMed

    Vanhees, Matthias; Verstreken, Frederik; van Riet, Roger

    2015-02-01

    Background The transverse carpal ligament is well known for its involvement in carpal tunnel syndrome, and sectioning of this ligament remains the definite treatment for this pathology. Some authors believe that the transverse carpal ligament is an important stabilizer of the carpal arch, whereas others do not consider it to be significant. Several studies have been performed, both in vivo and in in vitro. Sectioning of the transverse carpal ligament does not seem to have any effect on the width of the carpal arch in the unloaded condition. However, patients will load the arch during their activities of daily living. Materials and Methods A cadaveric study was done with distraction of the carpal bones before and after sectioning the transverse carpal ligament. Results With the transverse carpal ligament intact, the carpal arch is mobile, with distraction leading up to 50% widening of the arch. Sectioning of the transverse carpal ligament resulted in a significant widening of the carpal arch by a further 30%. Conclusions Loading of the carpal arch after sectioning of the transeverse carapal ligament leads to a significant increase in intracarpal mobility. This will inevitably influence carpal kinematics in the patient and might be responsible for some complications after simple carpal tunnel releases, such as pillar pain, palmar tenderness, and loss of grip strength.

  19. Normal planar undulators doubling as transverse gradient undulators

    NASA Astrophysics Data System (ADS)

    Jia, Qika; Li, Heting

    2017-02-01

    The transverse gradient undulator (TGU) has important application in the short-wavelength high-gain free electron lasers (FELs) driven by laser-plasma accelerators. However, the usual transversely tapered TGUs need special design and manufacture, and the transverse gradient cannot be tuned arbitrarily. In this paper we explore a new and simple method of using the natural transverse gradient of a normal planar undulator to compensate the beam energy spread effect. In this method, a vertical dispersion on the electron beam is introduced, then the dispersed beam passes through a normal undulator with a vertical off-axis orbit where the vertical field gradient is selected properly related to the dispersion strength and the beam energy spread. Theoretical analysis and numerical simulations for self-amplified spontaneous emission FELs based on laser plasma accelerators are presented, and indicate that this method can greatly reduce the effect of the beam energy spread, leading to a similar enhancement on FEL performance as the usual transversely tapered TGU, but with the advantages of economy, tunable transverse gradient and no demand of extra field for correcting the orbit deflection induced by the field gradient.

  20. Fault roughness and strength heterogeneity control earthquake size and stress drop

    NASA Astrophysics Data System (ADS)

    Zielke, O.; Galis, M.; Mai, P. M.

    2017-01-01

    An earthquake's stress drop is related to the frictional breakdown during sliding and constitutes a fundamental quantity of the rupture process. High-speed laboratory friction experiments that emulate the rupture process imply stress drop values that greatly exceed those commonly reported for natural earthquakes. We hypothesize that this stress drop discrepancy is due to fault-surface roughness and strength heterogeneity: an earthquake's moment release and its recurrence probability depend not only on stress drop and rupture dimension but also on the geometric roughness of the ruptured fault and the location of failing strength asperities along it. Using large-scale numerical simulations for earthquake ruptures under varying roughness and strength conditions, we verify our hypothesis, showing that smoother faults may generate larger earthquakes than rougher faults under identical tectonic loading conditions. We further discuss the potential impact of fault roughness on earthquake recurrence probability. This finding provides important information, also for seismic hazard analysis.

  1. Do buried-rupture earthquakes trigger less landslides than surface-rupture earthquakes for reverse faults?

    NASA Astrophysics Data System (ADS)

    Xu, Chong

    2014-07-01

    Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area.

  2. 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.

  3. Transverse correlations in multiphoton entanglement

    SciTech Connect

    Wen Jianming; Rubin, Morton H.; Shih Yanhua

    2007-10-15

    We have analyzed the transverse correlation in multiphoton entanglement. The generalization of quantum ghost imaging is extended to the N-photon state. The Klyshko's two-photon advanced-wave picture is generalized to the N-photon case.

  4. Performance of the transverse coupled-bunch feedback system in the SRRC

    SciTech Connect

    Hsu, K.T.; Kuo, C.C.; Kuo, C.H.; Lin, K.K.; Ueng, T.S.; Weng, W.T.

    1996-10-01

    A transverse feedback system has been implemented and commissioned in the SRRC storage ring to suppress transverse coupled-bunch oscillations of the electron beam. The system includes transverse oscillation detectors, notch filter, baseband quadrature processing circuitry, power amplifiers, and kickers. To control a large number of transverse coupled-bunch modes, the system is broad-band, bunch-by- bunch in nature. Because the system is capable of bunch-by-bunch correction, it can also be useful for suppressing instabilities introduced by ions. The sextupole strength was then reduced to improve dynamic aperture and hence lifetime of the storage ring.

  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. Method and apparatus for determining tensile strength

    DOEpatents

    Ratigan, Joe L.

    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.

  7. TRANSVERSE OSCILLATIONS IN CHROMOSPHERIC MOTTLES

    SciTech Connect

    Kuridze, D.; Mathioudakis, M.; Jess, D. B.; Keenan, F. P.; Morton, R. J.; Erdelyi, R.; Dorrian, G. D.

    2012-05-01

    A number of recent investigations have revealed that transverse waves are ubiquitous in the solar chromosphere. The vast majority of these have been reported in limb spicules and active region fibrils. We investigate long-lived, quiet-Sun, on-disk features such as chromospheric mottles (jet-like features located at the boundaries of supergranular cells) and their transverse motions. The observations were obtained with the Rapid Oscillations in the Solar Atmosphere instrument at the Dunn Solar Telescope. The data set is comprised of simultaneous imaging in the H{alpha} core, Ca II K, and G band of an on-disk quiet-Sun region. Time-distance techniques are used to study the characteristics of the transverse oscillations. We detect over 40 transverse oscillations in both bright and dark mottles, with periods ranging from 70 to 280 s, with the most frequent occurrence at {approx}165 s. The velocity amplitudes and transverse displacements exhibit characteristics similar to limb spicules. Neighboring mottles oscillating in-phase are also observed. The transverse oscillations of individual mottles are interpreted in terms of magnetohydrodynamic kink waves. Their estimated periods and damping times are consistent with phase mixing and resonant mode conversion.

  8. Dynamic Rupture Simulations Based on the Characterized Source Model of the 2011 Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Tsuda, Kenichi; Iwase, Satoshi; Uratani, Hiroaki; Ogawa, Sachio; Watanabe, Takahide; Miyakoshi, Jun'ichi; Ampuero, Jean Paul

    2017-01-01

    The 2011 Off the Pacific Coast of Tohoku earthquake (Tohoku earthquake, M w 9.0) occurred on the Japan Trench and caused a devastating tsunami. Studies of this earthquake have revealed complex features of its rupture process. In particular, the shallow parts of the fault (near the trench) hosted large slip and long period seismic wave radiation, whereas the deep parts of the rupture (near the coast) hosted smaller slip and strong radiation of short period seismic waves. Understanding such depth-dependent feature of the rupture process of the Tohoku earthquake is necessary as it may occur during future mega-thrust earthquakes in this and other regions. In this study, we investigate the "characterized source model" of the Tohoku earthquake through dynamic rupture simulations. This source model divides the fault plane into several parts characterized by different size and frictional strength (main asperity, background area, etc.) and is widely used in Japan for the prediction of strong ground motion and tsunami through kinematic rupture simulations. Our characterized source model of the Tohoku earthquake comprises a large shallow asperity with moderate frictional strength, small deep asperities with high frictional strength, a background area with low frictional strength, and an area with dynamic weakening close to the trench (low dynamic friction coefficient as arising from, e.g., thermal pressurization). The results of our dynamic rupture simulation reproduce the main depth-dependent feature of the rupture process of the Tohoku earthquake. We also find that the width of the area close to the trench (equal to the distance from the trench to the shallow asperity, interpreted as the size of the accretionary prism) and the presence of dynamic weakening in this area have a significant influence on the final slip distribution. These results are useful to construct characterized source models for other subduction zones with different scale of the accretionary prism, such

  9. 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)

  10. Intersonic shear cracks and fault ruptures

    NASA Astrophysics Data System (ADS)

    Rosakis, Ares J.

    2002-06-01

    Recent experimental observations of intersonic shear rupture events that occur in a variety of material systems have rekindled interest in the intersonic failure phenomenon. Since the early 1990s, engineers and scientists working in all length scales, from the atomistic, the structural, all the way up to the scale of the earth's deformation processes, have undertaken joint efforts to study this unexplored area of fracture mechanics. The analysis in the present article emphasizes the cooperative and complementary manner in which experimental observations and analytical and numerical developments have proceeded. The article first reviews early contributions to the theoretical literature of dynamic subsonic and intersonic fracture and highlights the significant differences between tensile and shear cracks. The article then uses direct laboratory observations as a framework for discussing the physics of intersonic shear rupture occurring in constitutively homogeneous (isotropic and anisotropic) as well as in inhomogeneous systems, all containing preferable crack paths or faults. Experiments, models, and field evidence at a variety of length scales (from the atomistic, the continuum, and up to the scale of geological ruptures) are used to discuss processes such as (1) shock wave formation, (2) large-scale frictional contact and sliding at the rupture faces, and (3) maximum attainable rupture speeds and rupture speed stability. Particular emphasis is given to geophysical field evidence and to the exploration of the possibility of intersonic fault rupture during shallow crustal earthquake events.

  11. Extraneural rupture of intraneural ganglion cysts.

    PubMed

    Shahid, Kameron R; Hébert-Blouin, Marie-Noëlle; Amrami, Kimberly K; Spinner, Robert J

    2011-01-01

    Rupture of simple (extraneural) cysts such as popliteal cysts (Baker's cysts) is a well-known occurrence. The purpose of this report is to introduce the similar occurrence of extraneural rupture of peroneal and tibial intraneural cysts in the knee region, describe the associated magnetic resonance imaging (MRI) findings, and identify risk factors. There was MRI evidence of rupture in 20 of 38 intraneural cases reviewed, mainly in the region of the fibular head and popliteal fossa. Ruptured intraneural cysts and simple cysts share these MRI findings: T2 hyperintense fluid within surrounding intermuscular fascial planes and enhancement with intravenous contrast consistent with inflammation. The mean maximal diameter of the ruptured intraneural cysts was statistically significantly smaller than that of the unruptured cysts. The authors believe that extraneural rupture of an intraneural cyst is due to increased intraarticular pressures transmitted within the cyst and/or elevated extrinsic pressure delivered to the cyst, such as by trauma, akin to the etiology of rupture of extraneural ganglion cysts.

  12. 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.

  13. Prediction of transverse fatigue behavior of unidirectionally reinforced metal matrix composites

    SciTech Connect

    John, R.; Buchanan, D.J.; Larsen, J.M.

    1998-11-03

    Unidirectionally reinforced metal matrix composites (MMC) are targeted for use in many aerospace applications which require high specific strength and stiffness at elevated temperatures. Such applications include blings and disks. The primary weakness of a component made of unidirectionally reinforced MMC is its susceptibility to transverse loads. The strength of the component in the transverse direction is significantly lower than that in the longitudinal direction under monotonic, sustained and fatigue loading conditions. Hence, replacement of monolithic components with MMC components requires that the transverse strength of the MMC should be predicted accurately. This paper discusses the applicability of a net-section based model to predict the fatigue behavior of [909] MMC under transverse loading.

  14. Rupture Following Biceps-to-Triceps Tendon Transfer in Adolescents and Young Adults With Spinal Cord Injury:

    PubMed Central

    Merenda, Lisa A.; Rutter, Laure; Curran, Kimberly; Kozin, Scott H.

    2012-01-01

    Background: Tendon transfer surgery can restore elbow extension in approximately 70% of persons with tetraplegia and often results in antigravity elbow extension strength. However, we have noted an almost 15% rupture/attenuation rate. Objective: This investigation was conducted to analyze potential causes in adolescents/young adults with spinal cord injury (SCI) who experienced tendon rupture or attenuation after biceps-to-triceps transfer. Methods: Medical charts of young adults with SCI who underwent biceps-to-triceps transfer and experienced tendon rupture or attenuation were reviewed. Data collected by retrospective chart review included general demographics, surgical procedure(s), use and duration of antibiotic treatment, time from tendon transfer surgery to rupture/attenuation, and method of diagnosis. Results: Twelve subjects with tetraplegia (mean age, 19 years) who underwent biceps-to-triceps reconstruction with subsequent tendon rupture or attenuation were evaluated. Mean age at time of tendon transfer was 18 years (range, 14-21 years). A fluoroquinolone was prescribed for 42% (n=5) of subjects. Tendon rupture was noted in 67% (n=8), and attenuation was noted in 33% (n=4). Average length of time from surgery to tendon rupture/attenuation was 5.7 months (range, 3-10 months). Conclusion: Potential contributing causes of tendon rupture/attenuation after transfer include surgical technique, rehabilitation, co-contraction of the transfer, poor patient compliance, and medications. In this cohort, 5 subjects were prescribed fluoroquinolones that have a US Food and Drug Administration black box concerning tendon ruptures. Currently, all candidates for upper extremity tendon transfer reconstruction are counseled on the effects of fluoroquinolones and the potential risk for tendon rupture. PMID:23459326

  15. Along-strike Variation in Fault Structural Maturity Dictates Location of Largest Earthquake Slip and Rupture Speed

    NASA Astrophysics Data System (ADS)

    Manighetti, I.; Perrin, C.; Ampuero, J. P.; Cappa, F.; Gaudemer, Y.

    2015-12-01

    We analyzed the slip distributions of ~30 large continental earthquakes for which the long-term propagation of the causative faults is known. The lengthening of faults over their long-term growth induces systematic changes of their structural maturity along their length. We find that, independent of where ruptures nucleated on the faults, largest earthquake slips systematically occurred on the most mature parts of the broken fault sections, whereas coseismic slip systematically tapered linearly over most of the rupture length in the direction of long-term fault propagation, i.e., decreasing maturity. Also, ruptures systematically propagated faster, up to supershear, along the most mature parts of the broken sections. We suggest that earthquake slip asymmetry and rupture acceleration are mainly governed by along-strike changes in fault zone strength, due to evolution of fault segmentation and off-fault damage with increasing maturity. The generic location of largest coseismic slip in the most mature part of a rupture zone is likely a static effect, resulting from the intimate elasto-static relation between stress drop, slip and elastic modulus of the faulted medium; even if stress drop is constant over the rupture, the strong reduction of elastic modulus in the zone of most intense damage off- the most mature fault section leads to significantly larger slip. Additionally, the pinning of fault slip by inter-segments decreases in direction of increasing maturity. The faster rupture speeds along the most mature rupture parts show that earthquake dynamics is also influenced by along-strike changes of fault maturity. The enhancement of rupture speed is likely due to interactions between rupture and trapped waves in the damage zone. Since the direction(s) of long-term fault propagation can generally be determined from geological evidence, it should be possible to anticipate in which direction earthquake slip will increase and accelerate, and possibly become a Big One.

  16. Extracellular matrix content of ruptured anterior cruciate ligament tissue.

    PubMed

    Young, Kate; Samiric, Tom; Feller, Julian; Cook, Jill

    2011-08-01

    Anterior cruciate ligaments (ACLs) can rupture with simple movements, suggesting that structural changes in the ligament may reduce the loading capacity of the ligament. We aimed to investigate if proteoglycan and collagen levels were different between ruptured and non-ruptured ACLs. We also compared changes in ruptured tissue over time. During arthroscopic knee reconstruction surgery 24 ruptured ACLs were collected from participants (10 females; 14 males; mean age 24 years). Four non-ruptured ACLs were obtained from participants undergoing total knee replacement surgery (one female, three males; mean age 66 years). Western blot analysis was used to characterise core proteins of aggrecan, versican, decorin and biglycan and glycosaminoglycan assays were also conducted. Collagen levels were measured by hydroxyproline (OHPr) assays. Significantly lower levels of collagen, were found in ruptured ACL compared to non-ruptured ACL (p=0.004). Lower levels of both small and large proteoglycans were found in ruptured than non-ruptured ACLs. No correlation was found between time since rupture and proteoglycan or collagen levels. Ruptured ACLs had less collagen and proteoglycans than non-ruptured ACLs. These changes indicate either extracellular matrix protein levels were reduced prior to rupture or levels decreased immediately after rupture. It is possible that the composition and structure of ACLs that rupture are different to normal ACLs, potentially reducing the tissue's ability to withstand loading. An enhanced understanding of the aetiology of ACL injury could help identify individuals who may be predisposed to rupture.

  17. Ruptured urinary bladder in a heifer.

    PubMed

    Roussel, A J; Ward, D S

    1985-06-15

    A yearling Holstein heifer was admitted with abdominal pain and bilateral, ventral abdominal distention. Bladder rupture was diagnosed by abdominocentesis and endoscopy. Correction of metabolic derangements was accomplished by volume diuresis, with maintenance of a urethral catheter before surgical repair of the bladder. The cause of the bladder rupture was believed to be related to adhesions resulting from previous surgery for urachal abscessation. Bladder rupture, which usually occurs in bulls or steers secondary to urolithiasis or in cows after dystocia, also should be considered in prepartum heifers with dehydration, abdominal pain, and abdominal distention.

  18. Plantar fascia rupture: diagnosis and treatment.

    PubMed

    Rolf, C; Guntner, P; Ericsäter, J; Turan, I

    1997-01-01

    Two patients with spontaneous medial plantar fascia rupture due to a definite injury with no prior symptoms, were referred to our institution. Clinically, there was a tender lump in the sole, and magnetic resonance imaging confirmed the diagnosis. Nonoperative treatment was sufficient in curing the acute total rupture. Endoscopic release was used on the partially ruptured plantar fascia, but it is probably more optimal in the acute phase. The literature provides no comparative data on operative or nonoperative treatment efficacy for this rare condition.

  19. History of surgery for ruptured disk.

    PubMed

    Patwardhan, R V; Hadley, M N

    2001-01-01

    The history of surgery for ruptured disk of the human spine began approximately a century ago. Advances in the understanding of symptoms and signs of root or cord compression, their relationship to the pathology, and the refinement in imaging techniques have contributed to the present surgical management of rupture disk disease. Historical findings relevant to the cervical, thoracic, and lumbosacral regions of the spine, with relevant pathophysiology, imaging, and surgical treatment, including the evolution of various surgical approaches are discussed. Surgeons and other contributors in the medical field are cited for their respective contributions to the evolution of the present operative approaches for disk ruptures in the cervical, thoracic, and lumbar spinal regions.

  20. Gastric rupture after the Heimlich maneuver.

    PubMed

    Bintz, M; Cogbill, T H

    1996-01-01

    Since 1975, the Heimlich maneuver has been widely applied to relieve upper airway obstruction caused by aspirated material. Life-threatening complications have been documented following this simple procedure. We report two cases of gastric rupture after use of the Heimlich maneuver. Both patients experienced pulmonary and abdominal symptoms. The diagnosis was confirmed in each case by the demonstration of free intraperitoneal air on an upright chest roentgenogram. Full-thickness gastric rupture along the lesser curvature of the stomach was repaired in both patients; one patient died. Abdominal pain or persistent abdominal distention despite nasogastric suction after the Heimlich maneuver should prompt evaluation for possible gastric rupture.

  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. Transverse deformations of extreme horizons

    NASA Astrophysics Data System (ADS)

    Li, Carmen; Lucietti, James

    2016-04-01

    We consider the inverse problem of determining all extreme black hole solutions to the Einstein equations with a prescribed near-horizon geometry. We investigate this problem by considering infinitesimal deformations of the near-horizon geometry along transverse null geodesics. We show that, up to a gauge transformation, the linearised Einstein equations reduce to an elliptic PDE for the extrinsic curvature of a cross-section of the horizon. We deduce that for a given near-horizon geometry there exists a finite dimensional moduli space of infinitesimal transverse deformations. We then establish a uniqueness theorem for transverse deformations of the extreme Kerr horizon. In particular, we prove that the only smooth axisymmetric transverse deformation of the near-horizon geometry of extreme Kerr, such that cross-sections of the horizon are marginally trapped surfaces, corresponds to that of the extreme Kerr black hole. Furthermore, we determine all smooth and biaxisymmetric transverse deformations of the near-horizon geometry of the five-dimensional extreme Myers-Perry black hole with equal angular momenta. We find a three parameter family of solutions such that cross-sections of the horizon are marginally trapped, which is more general than the known black hole solutions. We discuss the possibility that they correspond to new five-dimensional vacuum black holes.

  3. Strength Training

    MedlinePlus

    ... strengthens your heart and lungs. When you strength train with weights, you're using your muscles to ... see there are lots of different ways to train with weights. Try a few good basic routines ...

  4. Subducting plate geology in three great earthquake ruptures of the western Alaska margin, Kodiak to Unimak

    USGS Publications Warehouse

    von Huene, Roland; Miller, John J.; Weinrebe, Wilhelm

    2012-01-01

    Three destructive earthquakes along the Alaska subduction zone sourced transoceanic tsunamis during the past 70 years. Since it is reasoned that past rupture areas might again source tsunamis in the future, we studied potential asperities and barriers in the subduction zone by examining Quaternary Gulf of Alaska plate history, geophysical data, and morphology. We relate the aftershock areas to subducting lower plate relief and dissimilar materials in the seismogenic zone in the 1964 Kodiak and adjacent 1938 Semidi Islands earthquake segments. In the 1946 Unimak earthquake segment, the exposed lower plate seafloor lacks major relief that might organize great earthquake rupture. However, the upper plate contains a deep transverse-trending basin and basement ridges associated with the Eocene continental Alaska convergent margin transition to the Aleutian island arc. These upper plate features are sufficiently large to have affected rupture propagation. In addition, massive slope failure in the Unimak area may explain the local 42-m-high 1946 tsunami runup. Although Quaternary geologic and tectonic processes included accretion to form a frontal prism, the study of seismic images, samples, and continental slope physiography shows a previous history of tectonic erosion. Implied asperities and barriers in the seismogenic zone could organize future great earthquake rupture.

  5. Rupture of lenticulostriate artery aneurysms.

    PubMed

    Heck, Olivier; Anxionnat, René; Lacour, Jean-Christophe; Derelle, Anne-Laure; Ducrocq, Xavier; Richard, Sébastien; Bracard, Serge

    2014-02-01

    The authors report on 3 rare cases of ruptured lenticulostriate artery (LSA) aneurysms that were heralded by deep cerebral hematomas. The hematomas were unilateral in 2 cases and bilateral in 1; in the bilateral case, only a single LSA aneurysm could be identified on the right side of the brain. Because of their small size (≤ 2 mm), fusiform aspect, and deep location within the brain, all of the aneurysms were treated conservatively. There was no hemorrhage recurrence, and follow-up angiography demonstrated spontaneous thrombosis in 2 of the 3 cases. The clinical course was favorable in 2 of the 3 patients. The course in the patient with the bilateral hematoma was marked by an ischemic event after the initial episode, resulting in an aggravation of deficits. The cause of this second event was uncertain. Because our knowledge about the natural history of LSA aneurysms is incomplete, there is no consensus concerning a therapeutic strategy. The authors' experience in 3 reported cases leads them to think that a conservative approach involving close angiographic monitoring may be proposed as first-line treatment. If the monitored aneurysm then persists or grows in size, its occlusion should be considered. Nonetheless, other studies are needed to further strengthen the legitimacy of this strategy.

  6. Dynamic Rupture Modelling of the 1999 Düzce, Turkey Earthquake

    NASA Astrophysics Data System (ADS)

    Tanırcan, Gülüm; Dalguer, Luis; Bekler, Feyza Nur; Meral Özel, Nurcan

    2017-03-01

    The dynamic rupture process and near-source ground motion of the 1999 Mw 7.1 Düzce Earthquake are simulated. The fault rupture is governed by the slip-weakening friction model coupled to a three-dimensional viscoelastic wave equation. The problem is solved numerically by a 3-D dynamic rupture code that uses a generalized finite difference method. Initial parameterization of stress drop (Δ τ ) and strength excess (S_{e}) for dynamic rupture calculations is obtained from the slip velocity distribution of a kinematic waveform inversion (KI) model by solving the elastodynamic equation with the kinematic slip as a boundary condition. Using the kinematic slip distribution and observed ground motion as constraints, a trial and error procedure was followed to define the stress parameterization. Preferred model describes the source in terms of stress with three asperities (located, respectively, at the deep, middle and shallow) and strong barriers between asperities. S_{e} is as high as 19 Mpa at barriers between the three asperities and Δ τ is maximum about 40 Mpa at the deepest asperity. This heterogeneity in stress distribution produces abrupt jumps in rupture velocity, exhibiting locally apparent rupture speed exceeding the P wave velocity at the borders between barriers and asperities, due to sharp changes of fault strength and stress drop at those areas. Overall, consistent with other studies, the rupture propagation is dominated by supershear speed toward the eastern asperities and at shallow surface. Simulated surface rupture at the eastern fault is consistent with other studies; nevertheless, the western shallower parts did not rupture during the simulation, suggesting that those regions may have already broken during the 1999 Kocaeli event, which occurred three months earlier. Ground motion simulation catches the major characteristics of the observed waveforms. Distribution of simulated peak ground velocity (PGV) in low frequency (0.1-0.5 Hz.) inside the

  7. Unusual repair in a rare case of hepatothorax due to right-sided diaphragmatic rupture: case report.

    PubMed

    Quadrozzi, F; Favoriti, P; Favoriti, M; Cofini, G

    2016-01-01

    Intra-thoracic herniation of abdominal organs following diaphragmatic rupture represents an unusual clinical occurrence with great diagnostic difficulty. The authors present a case of right diaphragmatic rupture related to peritonitis due to perforated duodenal ulcer in previous (1 year before) thoraco-abdominal trauma with complete intra-thoracic herniation of the liver, gallbladder, ascending and transverse colon and lung collapse. The preoperative diagnosis has been based on clinical, chest X-ray, and ultrasound examination. The patient, because of very serious respiratory and hemodynamic distress, immediately underwent surgery (thoraco-laparotomic approach) with reduction of the liver, gallbladder, ascending and transverse colon in the abdominal cavity, perforated duodenal ulcer suture and repair of diaphragmatic tear using an unusual repair mode: suture of autologous fascia lata graft to the diaphragm. Postoperative chest radiography showed the normal location of right diaphragmatic border.

  8. Unusual repair in a rare case of hepatothorax due to right-sided diaphragmatic rupture: case report

    PubMed Central

    QUADROZZI, F.; FAVORITI, P.; FAVORITI, M.; COFINI, G.

    2016-01-01

    Intra-thoracic herniation of abdominal organs following diaphragmatic rupture represents an unusual clinical occurrence with great diagnostic difficulty. The authors present a case of right diaphragmatic rupture related to peritonitis due to perforated duodenal ulcer in previous (1 year before) thoraco-abdominal trauma with complete intra-thoracic herniation of the liver, gallbladder, ascending and transverse colon and lung collapse. The preoperative diagnosis has been based on clinical, chest X-ray, and ultrasound examination. The patient, because of very serious respiratory and hemodynamic distress, immediately underwent surgery (thoraco-laparotomic approach) with reduction of the liver, gallbladder, ascending and transverse colon in the abdominal cavity, perforated duodenal ulcer suture and repair of diaphragmatic tear using an unusual repair mode: suture of autologous fascia lata graft to the diaphragm. Postoperative chest radiography showed the normal location of right diaphragmatic border. PMID:27381695

  9. Plantaris rupture: why is it important?

    PubMed

    Rohilla, Seema; Jain, Nitin; Yadav, Rohtas

    2013-01-22

    Plantaris muscle is accessory plantar flexor of calf, a vestigial muscle of triceps surae complex. Its importance lies in the fact that its rupture cans mimic deep vein thrombosis (DVT). Sometimes when there is rupture of Achilles tendon, intact plantaris can still cause plantar flexion at ankle presenting a confusing picture. We present one such case of plantaris rupture confused by radiology resident with DVT. A 51-year-old man had a feeling as if kicked in back of calf along with a snapping sound and severe pain while playing tennis. On seeing fluid between muscle plane and a hypoechoic structure radiology resident labelled it DVT. MRI suggested ruptured plantaris as fluid and muscle stump were seen between gastronemius and soleus. Patient was treated conservatively with rest, ice compression and elevated leg and showed significant reduction in pain and swelling.

  10. Acute Iliac Artery Rupture: Endovascular Treatment

    SciTech Connect

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

    2007-04-15

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

  11. Cognitive frames in psychology: demarcations and ruptures.

    PubMed

    Yurevich, Andrey V

    2009-06-01

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

  12. 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.

  13. A case of traumatic pericardiophrenic rupture.

    PubMed

    Stefani, A; Brandi, L; Ruggiero, C; Lodi, R

    1998-12-01

    An unusual case of traumatic pericardiophrenic rupture is presented. The defect was limited to the central tendon of the diaphragm, with herniation of the stomach into the pericardial sac. A correct preoperative diagnosis was not made because laparotomy was quickly performed for splenic rupture. Successful operative repair of the tear was performed, with interrupted reabsorbable sutures. The case is discussed and the management of patients with these rare lesions is reviewed.

  14. Transversely isotropic elasticity imaging of cancellous bone.

    PubMed

    Shore, Spencer W; Barbone, Paul E; Oberai, Assad A; Morgan, Elise F

    2011-06-01

    , the effects of noise on reconstruction quality is demonstrated and a signal-to-noise ratio (SNR) of 40 dB is identified as a reasonable threshold for obtaining accurate reconstructions from experimental data. This study demonstrates that given an appropriate set of displacement fields, level of regularization, and signal strength, the transversely isotropic method can recover the relative magnitudes of all five elastic parameters without an independent measurement of stress. The quality of the reconstructions improves with increasing contrast, magnitude of deformation, and asymmetry in the distributions of material properties, indicating that elasticity imaging of cancellous bone could be a useful tool in laboratory studies to monitor the progression of damage and disease in this tissue.

  15. Transversely Isotropic Elasticity Imaging of Cancellous Bone

    PubMed Central

    Shore, Spencer W.; Barbone, Paul E.; Oberai, Assad A.; Morgan, Elise F.

    2012-01-01

    of noise on reconstruction quality is demonstrated and a signal-to-noise ratio (SNR) of 40 dB is identified as a reasonable threshold for obtaining accurate reconstructions from experimental data. This study demonstrates that given an appropriate set of displacement fields, level of regularization, and signal strength, the transversely isotropic method can recover the relative magnitudes of all five elastic parameters without an independent measurement of stress. The quality of the reconstructions improves with increasing contrast, magnitude of deformation, and asymmetry in the distributions of material properties, indicating that elasticity imaging of cancellous bone could be a useful tool in laboratory studies to monitor the progression of damage and disease in this tissue. PMID:21744922

  16. Realizing vector meson dominance with transverse charge densities

    SciTech Connect

    Gerald Miller, Mark Strikman, Christian Weiss

    2011-10-01

    The transverse charge density in a fast-moving nucleon is represented as a dispersion integral of the imaginary part of the Dirac form factor in the timelike region (spectral function). At a given transverse distance b the integration effectively extends over energies in a range {radical}t {approx}< 1/b, with exponential suppression of larger values. The transverse charge density at peripheral distances thus acts as a low-pass filter for the spectral function and allows one to select energy regions dominated by specific t-channel states, corresponding to definite exchange mechanisms in the spacelike form factor. We show that distances b {approx} 0.5 - 1.5 fm in the isovector density are maximally sensitive to the {rho} meson region, with only a {approx}10% contribution from higher-mass states. Soft-pion exchange governed by chiral dynamics becomes relevant only at larger distances. In the isoscalar density higher-mass states beyond the {omega} are comparatively more important. The dispersion approach suggests that the positive transverse charge density in the neutron at b {approx} 1 fm, found previously in a Fourier analysis of spacelike form factor data, could serve as a sensitive test of the isoscalar strength in the {approx}1 GeV mass region. In terms of partonic structure, the transverse densities in the vector meson region b {approx} 1 fm support an approximate mean-field picture of the motion of valence quarks in the nucleon.

  17. Cosmology in Weyl transverse gravity

    NASA Astrophysics Data System (ADS)

    Oda, Ichiro

    2016-11-01

    We study the Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology in the Weyl-transverse (WTDiff) gravity in a general spacetime dimension. The WTDiff gravity is invariant under both the local Weyl (conformal) transformation and the volume preserving diffeormorphisms (transverse diffeomorphisms) and is believed to be equivalent to general relativity at least at the classical level (perhaps, even in the quantum regime). It is explicitly shown by solving the equations of motion that the FLRW metric is a classical solution in the WTDiff gravity only when the spatial metric is flat, that is, the Euclidean space, and the lapse function is a nontrivial function of the scale factor.

  18. Probabilities of transversions and transitions.

    PubMed

    Vol'kenshtein, M V

    1976-01-01

    The values of the mean relative probabilities of transversions and transitions have been refined on the basis of the data collected by Jukes and found to be equal to 0.34 and 0.66, respectively. Evolutionary factors increase the probability of transversions to 0.44. The relative probabilities of individual substitutions have been determined, and a detailed classification of the nonsense mutations has been given. Such mutations are especially probable in the UGG (Trp) codon. The highest probability of AG, GA transitions correlates with the lowest mean change in the hydrophobic nature of the amino acids coded.

  19. Indentation of Transversely Isotropic Materials

    NASA Astrophysics Data System (ADS)

    Bhat, Talapady Srivatsa

    Instrumented indentation, as a tool for characterization of mechanical properties, has well been established in the past decades. Studies have been conducted to understand the behavior of isotropic materials under indentation and techniques to accurately predict isotropic material properties have also been reported. Further, within the isotropic regime, work has been done to predict the indentation hardness without having to investigate the area of contact during indentation. Studies have also reported the prospect of utilizing indentation to predict the fatigue behavior of isotropic materials. This dissertation is made with the intent of extending the use of indentation, as a characterization tool, to the anisotropic regime. The effect of transverse isotropy on the indentation response of materials is systematically studied here. Extensive computational analysis is performed to elucidate the underlying deformation mechanics of indentation of transversely isotropic materials. Owing to the anisotropy, indentation may be performed parallel or perpendicular to the plane of isotropy of the specimen. It is observed that the indentation response varies significantly for each of these cases. The two cases are treated as unique and an identical systematic analysis is carried for both. The indentation orientations shall henceforth be referred to as transverse and longitudinal indentation for indentation parallel and perpendicular to the plane of isotropy respectively. A technique is developed capable of extracting the elastic-plastic properties of transversely isotropic materials from interpretation of indentation response in either direction. The technique is rigorously tested for its robustness, accuracy and uniqueness of results. A sensitivity analysis is performed to determine how sensitive the technique is to errors in experimental results. Rigorous studies are performed to understand the variation in pile-up or sink-in during indentation with varying anisotropy in the

  20. Peridynamic Modeling of Ruptures in Biomembranes

    PubMed Central

    Jesorka, Aldo; Bertoldi, Katia

    2016-01-01

    We simulate the formation of spontaneous ruptures in supported phospholipid double bilayer membranes, using peridynamic modeling. Experiments performed on spreading double bilayers typically show two distinct kinds of ruptures, floral and fractal, which form spontaneously in the distal (upper) bilayer at late stages of double bilayer formation on high energy substrates. It is, however, currently unresolved which factors govern the occurrence of either rupture type. Variations in the distance between the two bilayers, and the occurrence of interconnections (“pinning sites”) are suspected of contributing to the process. Our new simulations indicate that the pinned regions which form, presumably due to Ca2+ ions serving as bridging agent between the distal and the proximal bilayer, act as nucleation sites for the ruptures. Moreover, assuming that the pinning sites cause a non-zero shear modulus, our simulations also show that they change the rupture mode from floral to fractal. At zero shear modulus the pores appear to be circular, subsequently evolving into floral pores. With increasing shear modulus the pore edges start to branch, favoring fractal morphologies. We conclude that the pinning sites may indirectly determine the rupture morphology by contributing to shear stress in the distal membrane. PMID:27829001

  1. 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

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

    PubMed

    Chen, Bin; Li, Runguang; Zhang, Sheng

    2012-08-01

    Neglected rupture of the patellar tendon is rare but becomes more difficult to repair the longer it is left untreated. The most common rupture sites are the inferior pole of the patella and distal insertion. Proximal retraction of the patella and extensor mechanism adhesions makes the treatment more difficult than acute tendon rupture. We report two patients with neglected patellar tendon rupture treated by reconstruction and restoration using semitendinosus-gracilis (STG) tendons with preserved distal insertions. Preserved distal insertion provided sufficient blood supply to accelerate healing, while combined fixation with tension-reducing wire, offered the initial stability of the closed-loop sutured tendon. Both patients reacquired near normal strength and stability of the patellar tendon and restoration of function after operation and rehabilitation.

  3. Application of high-velocity friction experiments to the shear rupture of a fault in an elastic half-space

    NASA Astrophysics Data System (ADS)

    Liao, Zonghu; Reches, Zeev

    2013-04-01

    We developed a physics-based model for earthquake rupture by numerically simulating shear rupture along a 2D vertical fault with the dynamic frictional strength of granite under high slip velocity. Recent experimental observations indicated that the steady-state frictional strength of silica-rich igneous rocks (granite, syenite, diorite) alternate between dynamic-weakening under low velocity (V < 0.03 m/s) and dynamic-strengthening under higher velocities (V > 0.03 m/s). This strength alternation was attributed to powder-lubrication (weakening), and powder dehydration (strengthening) (Sammis et al., 2011). We used the dynamic friction law which was determined on samples of Sierra White granite under experimental velocities approaching 1 m/s (Reches and Lockner, 2010). We converted their observed friction-distance-velocity relations into an empirical friction model referred to as WEST (WEakening - STrengthening). For the simulation calculations, we used the spectral element code of Ampuero (web.gps.caltech.edu/~ampuero/software), which computes the spontaneous rupture propagation along an anti-plane shear (mode III) fracture in an elastic half-space. In the present analysis, the WEST friction model is used as the fault strength while keeping all other parameters (crust properties and stresses) the same as Version 3 of the Southern California Earthquake Center (SCEC) benchmark problem (Harris et al., 2004). This approach allows for direct comparison between the WEST rupture and the benchmark rupture with a fault of slip-weakening friction model (Rojas et al., 2008). We found the following differences between the ruptures of the two models: (1) WEST-based rupture occurs earlier at all observation points away from the nucleation zone; (2) WEST-based model has lower (~ 35%) peak velocity and shorter rise-time; and (3) WEST-based rupture shows rich, frequent alteration of slip velocity, and consequently, the simulated rupture is more complex in stress drop, displacements

  4. High-strength iron aluminide alloys

    SciTech Connect

    McKamey, C.G.; Maziasz, P.J.

    1996-06-01

    Past studies have shown that binary Fe{sub 3}Al possesses low creep-rupture strength compared to many other alloys, with creep-rupture lives of less than 5 h being reported for tests conducted at 593{degrees}C and 207 MPa. The combination of poor creep resistance and low room-temperature tensile ductility due to a susceptibility to environmentally-induced dynamic hydrogen embrittlement has limited use of these alloys for structural applications despite their excellent corrosion properties. With regard to the ductility problem, alloy development efforts have produced significant improvements, with ductilities of 10-20% and tensile yield strengths as high as 500 MPa being reported. Likewise, initial improvements in creep resistance have been realized through small additions of Mo, Nb, and Zr.

  5. 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.

  6. 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.

  7. In situ strengths of matrix in a composite

    NASA Astrophysics Data System (ADS)

    Huang, Zheng-Ming; Xin, Li-Min

    2017-02-01

    A major obstacle to achieving reasonable strength prediction of a composite only from its constituent information is in the determination of in situ strengths of the matrix. One can measure only the original strengths of the pure matrix, on the basis of which the predicted transverse strengths of a unidirectional (UD) composite are far from reality. It is impossible to reliably measure matrix in situ strengths. This paper focuses on the correlation between in situ and original strengths. Stress concentrations in a matrix owing to the introduction of fibers are attributed to the strength variation. Once stress concentration factors (SCFs) are obtained, the matrix in situ strengths are assigned as the original counterparts divided by them. Such an SCF cannot be defined following a classical approach. All of the relevant issues associated with determining it are systematically addressed in this paper. Analytical expressions for SCFs under transverse tension, transverse compression, and transverse shear are derived. Closed-form and compact formulas for all of the uniaxial strengths of a UD composite are first presented in this paper. Their application to strength predictions of a number of typical UD composites demonstrates the correctness of these formulas.

  8. Rupture of the cell envelope by induced intracellular gas phase expansion in gas vacuolate bacteria.

    PubMed Central

    Hemmingsen, B B; Hemmingsen, E A

    1980-01-01

    Using a new approach, we estimated the physical strength of the cell envelopes of three species of gram-negative, gas vacuolate bacteria (Microcyclus aquaticus, Prosthecomicrobium pneumaticum, and Meniscus glaucopis). Populations of cells were slowly (0.5 to 2.9 h) saturated with argon, nitrogen, or helium to final pressures up to 100 atm (10, 132 kPa). The gas phases of the vesicles remained intact and, upon rapid (1 to 2 s) decompression to atmospheric pressure, expanded and ruptured the cells; loss of colony-forming units was used as an index of rupture. Because the cell envelope is the cellular component most likely to resist the expanding intracellular gas phase, its strength can be estimated from the minimum gas pressures that produce rupture. The viable counts indicated that these minimum pressures were between 25 and 50 atm; the majority of the cell envelopes were ruptured at pressures between 50 and 100 atm. Cells in which the gas vesicles were collapsed and the gas phases were effectively dissolved by rapid compression tolerated decompression from much higher gas saturations. Cells that do not normally possess gas vesicles (Escherichia coli) or that had been prevented from forming them by addition of L-lysine to the medium (M. aquaticus) were not harmed by decompression from gas saturation pressures up to 300 atm. PMID:7204336

  9. Hemorrhagic Longitudinally Extensive Transverse Myelitis.

    PubMed

    Wu, Chris Y; Riangwiwat, Tanawan; Nakamoto, Beau K

    2016-01-01

    Longitudinally extensive transverse myelitis (LETM) may be associated with viral triggers, including both infections and vaccinations. We present a case of a healthy immunocompetent 33-year-old woman who developed a hemorrhagic LETM 2 weeks after seasonal influenza vaccination. Hemorrhagic LETM has not to our knowledge been reported after influenza vaccination. It may represent a forme fruste variant of acute hemorrhagic leukoencephalitis.

  10. Transverse effects in UV FELs

    SciTech Connect

    Small, D.W.; Wong, R.K.; Colson, W.B.

    1995-12-31

    In an ultraviolet Free Electron Laser (UV FEL), the electron beam size can be approximately the same as the optical mode size. The performance of a UV FEL is studied including the effect of emittance, betatron focusing, and external focusing of the electron beam on the transverse optical mode. The results are applied to the Industrial Laser Consortium`s UV FEL.

  11. A creep-rupture model of filament-wound spherical pressure vessels

    NASA Technical Reports Server (NTRS)

    Dozier, Jan D.; Hackett, Robert M.

    1987-01-01

    The creep-rupture model is that of a quasi-isotropic filament-wound spherical pressure vessel, subjected to internal pressurization. The matrix material of the composite system is assumed to be linearly viscoelastic. Internal damage resulting from the relaxation of the matrix and the corresponding increase in microcracks is represented by a functional relationship between circumferential strain and transverse modulus. The numerical solution to this nonlinear problem is an iterative technique, whereby the elastic-viscoelastic correspondence principle is employed. In the Laplace domain, the associated elastic solution is obtained and this solution is inverted by the multidata method to yield the time-dependent solution.

  12. Transverse force on transversely polarized quarks in longitudinally polarized nucleons

    NASA Astrophysics Data System (ADS)

    Abdallah, Manal; Burkardt, Matthias

    2016-11-01

    We study the semiclassical interpretation of the x3 and x4 moments of twist-3 parton distribution functions (PDFs). While no semiclassical interpretation for the higher moments of gT(x ) and e (x ) was found, the x3 moment of the chirally odd spin-dependent twist-3 PDF hL3(x ) can be related to the longitudinal gradient of the transverse force on transversely polarized quarks in longitudinally polarized nucleons in a deep-inelastic scattering experiment. We discuss how this result relates to the torque acting on a quark in the same experiment. This has further implications for comparisons between the Jaffe-Manohar and the Ji decompositions of the nucleon spin.

  13. Creep-rupture behavior of candidate Stirling engine alloys after long-term aging at 760/sup 0/C in low-pressure hydrogen

    SciTech Connect

    Titran, R.H.

    1984-05-01

    Nine candidate Stirling automotive engine alloys were aged at 760/sup 0/C for 3500 h 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 on current MOD 1A Stirling engine design criteria of a 55% urban - 45% highway driving cycle; CG-27 has adequate 3500 h - 87/sup 0/C creep-rupture strength and SA-F11, CRM-6D, and XF-818 have adequate 3500 h - 775/sup 0/C creep-rupture strength.

  14. 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.

  15. The transverse mechanical behaviour of glass fibre reinforced plastics

    NASA Astrophysics Data System (ADS)

    Wells, Garry Michael

    The importance of transverse cracking in composites technology is highlighted by the use of classical lamination theory to predict the sequential damage process in cross-plied laminates. The literature on transverse fibre carposite behaviour is comprehensively reviewed, with particular emphasis on papers which present quantitative theoretical models. No work reviewed has measured the full range of mechanical properties on a single material necessary to allow a complete assessment of all the models of transverse failure. A resin system, based on epoxy/urethane blends, has been identified which allows production of high quality unidirectional composites with a systematic variation in flexibility. A preliminary experimental programme has identified those test specimens which can provide the necessary stress/strain and toughness properties of the range of flexibilised materials and thereby allow a validation of the theoretical models reviewed. In the preliminary experimental programme, transverse cracks are shown to extend with an increasing fracture toughness due to the formation of a 'tied zone' of fracture face bridging 'stringers' behind the crack tip. The influence of this effect on crack stability is discussed. By modelling the balance between fracture and strain energies, the equilibrium state of individual stringers is predicted. Direct observations of equilibrium stringer angles are seen to correspond with these predictions. A quite general model is developed which predicts, with reasonble accuracy, the observed increase of fracture toughness with crack extension and the geometry dependence of this increase. The literature models of stiffness, strength and failure strain are seen to display a dissappointing lack of agreement with the experimental results over the full range of material flexibilities. The influence of matrix Poisson constraint on these properties is discussed. Fracture toughness results indicate that very large critical defects control

  16. Rupture history of 2014 Mw 6.0 South Napa earthquake inferred from near-fault strong motion data and its impact to the practice of ground strong motion prediction

    NASA Astrophysics Data System (ADS)

    Ji, Chen; Archuleta, Ralph J.; Twardzik, Cedric

    2015-04-01

    The spatiotemporal rupture history of the 2014 South Napa earthquake is constrained using near-fault strong motion records. An aggressive source parameterization with 1372 subfaults is adopted to match the signals in the transverse components up to 4 Hz. The result reveals that the rupture of the Napa earthquake initiated at a depth of 9.84 km and propagated mainly to north-northwest (NNW) and updip on a 13 km long fault patch. A gradual increase in average rise time when the rupture propagates to shallower depth is observed. However, it is the rupture of a small (Mw 4.9), isolated, and high stress drop fault patch that excited the largest ground acceleration at stations south of the epicenter. Such fine-scale rupture heterogeneity shall be considered during seismic hazard analysis.

  17. 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.

  18. Creep-rupture tests of internally pressurized Hastelloy-X tubes

    NASA Technical Reports Server (NTRS)

    Gumto, K. H.; Colantino, G. J.

    1973-01-01

    Seamless Hastelloy-X tubes with 0.375-in. outside diameter and 0.025-in. wall thickness were tested to failure at temperatures from 1400 to 1650 F and internal helium pressures from 800 to 1800 psi. Lifetimes ranged from 58 to 3600 hr. The creep-rupture strength of the tubes was from 20 to 40 percent lower than that of sheet specimens. Larson-Miller correlations and photomicrographs of some specimens are presented.

  19. Ceramic Composite Intermediate Temperature Stress-Rupture Properties Improved Significantly

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Hurst, Janet B.

    2002-01-01

    Silicon carbide (SiC) composites are considered to be potential materials for future aircraft engine parts such as combustor liners. It is envisioned that on the hot side (inner surface) of the combustor liner, composites will have to withstand temperatures in excess of 1200 C for thousands of hours in oxidizing environments. This is a severe condition; however, an equally severe, if not more detrimental, condition exists on the cold side (outer surface) of the combustor liner. Here, the temperatures are expected to be on the order of 800 to 1000 C under high tensile stress because of thermal gradients and attachment of the combustor liner to the engine frame (the hot side will be under compressive stress, a less severe stress-state for ceramics). Since these composites are not oxides, they oxidize. The worst form of oxidation for strength reduction occurs at these intermediate temperatures, where the boron nitride (BN) interphase oxidizes first, which causes the formation of a glass layer that strongly bonds the fibers to the matrix. When the fibers strongly bond to the matrix or to one another, the composite loses toughness and strength and becomes brittle. To increase the intermediate temperature stress-rupture properties, researchers must modify the BN interphase. With the support of the Ultra-Efficient Engine Technology (UEET) Program, significant improvements were made as state-of-the-art SiC/SiC composites were developed during the Enabling Propulsion Materials (EPM) program. Three approaches were found to improve the intermediate-temperature stress-rupture properties: fiber-spreading, high-temperature silicon- (Si) doped boron nitride (BN), and outside-debonding BN.

  20. Transverse shape of the electron

    SciTech Connect

    Hoyer, Paul; Kurki, Samu

    2010-01-01

    We study the charge density, form factors and spin distributions of the electron induced by its |e{gamma}> light-front Fock state in impact parameter space. Only transversally compact Fock states contribute to the leading behavior of the Dirac and Pauli form factors as the momentum transfer tends to infinity. Power suppressed contributions are not compact, and distributions weighted by the transverse size have endpoint contributions. The Fock state conserves the spin of the parent electron locally, but the separate contributions of the electron, photon, and orbital angular momentum depend on longitudinal momentum and impact parameter. The sign of the anomalous magnetic moment of the electron may be understood intuitively from the density distribution, addressing a challenge by Feynman.

  1. Subpatch roughness in earthquake rupture investigations

    NASA Astrophysics Data System (ADS)

    Zielke, O.; Mai, P. M.

    2016-03-01

    Fault geometric complexities exhibit fractal characteristics over a wide range of spatial scales (<µm to > km) and strongly affect the rupture process at corresponding scales. Numerical rupture simulations provide a framework to quantitatively investigate the relationship between a fault's roughness and its seismic characteristics. Fault discretization, however, introduces an artificial lower limit to roughness. Individual fault patches are planar and subpatch roughness—roughness at spatial scales below fault patch size—is not incorporated. Does negligence of subpatch roughness measurably affect the outcome of earthquake rupture simulations? We approach this question with a numerical parameter space investigation and demonstrate that subpatch roughness significantly modifies the slip-strain relationship—a fundamental aspect of dislocation theory. Faults with subpatch roughness induce less strain than their planar-fault equivalents at distances beyond the length of a slipping fault. We further provide regression functions that characterize the stochastic effect subpatch roughness.

  2. Hemorrhagic Longitudinally Extensive Transverse Myelitis

    PubMed Central

    Wu, Chris Y.; Riangwiwat, Tanawan

    2016-01-01

    Longitudinally extensive transverse myelitis (LETM) may be associated with viral triggers, including both infections and vaccinations. We present a case of a healthy immunocompetent 33-year-old woman who developed a hemorrhagic LETM 2 weeks after seasonal influenza vaccination. Hemorrhagic LETM has not to our knowledge been reported after influenza vaccination. It may represent a forme fruste variant of acute hemorrhagic leukoencephalitis. PMID:27847660

  3. 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.

  4. Transverse spin effects at COMPASS

    SciTech Connect

    Pesaro, G.

    2009-03-23

    The COMPASS experiment at the CERN SPS has a broad physics program focused on the nucleon spin structure and on hadron spectroscopy, using both muon and hadron beams. One of the main objectives for the spin program with the muon beam is the measurement of transverse spin effects in semi inclusive deep inelastic scattering. A longitudinally polarized 160 GeV/c muon beam is impinging on a transversely polarized target: from 2002 to 2004 a {sup 6}LiD(deuteron) target has been used, while during 2007 data taking a NH{sub 3}(proton) target was put in place. All measured transverse asymmetries on deuteron have been found to be small, and compatible with zero, within the few percent statistical errors. These results, which are currently used as input for global fits, can be interpreted as cancellation between u and d quark contribution in the deuteron. The first results for the Collins and Sivers asymmetries for charged hadrons from the 2007 proton COMPASS data are also presented and discussed.

  5. Traumatic rupture of the thoracic aorta

    PubMed Central

    Keen, G.; Bradbrook, R. A.; McGinn, F.

    1969-01-01

    Seven patients who had traumatic ruptures of the thoracic aorta are reported. Four of these died within a few hours of admission, allowing no opportunity for diagnosis or treatment. However, three survived long enough for elective surgery to be undertaken. A diagnosis of ruptured aorta was missed in one patient (case 2), and the difficulties of diagnosing this condition, even during thoracotomy, are emphasized. The value of serial chest radiography and forward aortography is discussed. Two of these patients underwent successful aortic repair, using left atrio-femoral bypass. Images PMID:5763507

  6. Rupture of the plantar fascia in athletes.

    PubMed

    Leach, R; Jones, R; Silva, T

    1978-06-01

    Symptoms resembling those of plantar fasciitis were seen in six athletes who were thought to have a partial rupture of the plantar fascia. Treatment, which included the use of crutches, anti-inflammatory agents, strapping of the arch, and ice packs, was successful in all but one patient who had a painful mass in the area of the previous rupture. After surgical excision of the painful mass and release of the fascia, he recovered. Five of the six athletes had been previously treated with repeated local injections of steroid.

  7. Tendon ruptures: mallet, flexor digitorum profundus.

    PubMed

    Yeh, Peter C; Shin, Steven S

    2012-08-01

    Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx.

  8. 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.

  9. On the initiation of sustained slip-weakening ruptures by localized stresses

    NASA Astrophysics Data System (ADS)

    Galis, M.; Pelties, C.; Kristek, J.; Moczo, P.; Ampuero, J.-P.; Mai, P. M.

    2015-02-01

    Numerical simulations of dynamic earthquake rupture require an artificial initiation procedure, if they are not integrated in long-term earthquake cycle simulations. A widely applied procedure involves an `overstressed asperity', a localized region stressed beyond the static frictional strength. The physical properties of the asperity (size, shape and overstress) may significantly impact rupture propagation. In particular, to induce a sustained rupture the asperity size needs to exceed a critical value. Although criteria for estimating the critical nucleation size under linear slip-weakening friction have been proposed for 2-D and 3-D problems based on simplifying assumptions, they do not provide general rules for designing 3-D numerical simulations. We conduct a parametric study to estimate parameters of the asperity that minimize numerical artefacts (e.g. changes of rupture shape and speed, artificial supershear transition, higher slip-rate amplitudes). We examine the critical size of square, circular and elliptical asperities as a function of asperity overstress and background (off-asperity) stress. For a given overstress, we find that asperity area controls rupture initiation while asperity shape is of lesser importance. The critical area obtained from our numerical results contrasts with published theoretical estimates when background stress is low. Therefore, we derive two new theoretical estimates of the critical size under low background stress while also accounting for overstress. Our numerical results suggest that setting the asperity overstress and area close to their critical values eliminates strong numerical artefacts even when the overstress is large. We also find that properly chosen asperity size or overstress may significantly shorten the duration of the initiation. Overall, our results provide guidelines for determining the size of the asperity and overstress to minimize the effects of the forced initiation on the subsequent spontaneous rupture

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

    NASA Astrophysics Data System (ADS)

    Hirauchi, Ken-ichi; Muto, Jun

    2015-02-01

    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 (μ 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.

  11. General planar transverse domain walls realized by optimized transverse magnetic field pulses in magnetic biaxial nanowires

    NASA Astrophysics Data System (ADS)

    Li, Mei; Wang, Jianbo; Lu, Jie

    2017-02-01

    The statics and field-driven dynamics of transverse domain walls (TDWs) in magnetic nanowires (NWs) have attracted continuous interests because of their theoretical significance and application potential in future magnetic logic and memory devices. Recent results demonstrate that uniform transverse magnetic fields (TMFs) can greatly enhance the wall velocity, meantime leave a twisting in the TDW azimuthal distribution. For application in high-density NW devices, it is preferable to erase the twisting so as to minimize magnetization frustrations. Here we report the realization of a completely planar TDW with arbitrary tilting attitude in a magnetic biaxial NW under a TMF pulse with fixed strength and well-designed orientation profile. We smooth any twisting in the TDW azimuthal plane thus completely decouple the polar and azimuthal degrees of freedom. The analytical differential equation describing the polar angle distribution is derived and the resulting solution is not the Walker-ansatz form. With this TMF pulse comoving, the field-driven dynamics of the planar TDW is investigated with the help of the asymptotic expansion method. It turns out the comoving TMF pulse increases the wall velocity under the same axial driving field. These results will help to design a series of modern magnetic devices based on planar TDWs.

  12. General planar transverse domain walls realized by optimized transverse magnetic field pulses in magnetic biaxial nanowires

    PubMed Central

    Li, Mei; Wang, Jianbo; Lu, Jie

    2017-01-01

    The statics and field-driven dynamics of transverse domain walls (TDWs) in magnetic nanowires (NWs) have attracted continuous interests because of their theoretical significance and application potential in future magnetic logic and memory devices. Recent results demonstrate that uniform transverse magnetic fields (TMFs) can greatly enhance the wall velocity, meantime leave a twisting in the TDW azimuthal distribution. For application in high-density NW devices, it is preferable to erase the twisting so as to minimize magnetization frustrations. Here we report the realization of a completely planar TDW with arbitrary tilting attitude in a magnetic biaxial NW under a TMF pulse with fixed strength and well-designed orientation profile. We smooth any twisting in the TDW azimuthal plane thus completely decouple the polar and azimuthal degrees of freedom. The analytical differential equation describing the polar angle distribution is derived and the resulting solution is not the Walker-ansatz form. With this TMF pulse comoving, the field-driven dynamics of the planar TDW is investigated with the help of the asymptotic expansion method. It turns out the comoving TMF pulse increases the wall velocity under the same axial driving field. These results will help to design a series of modern magnetic devices based on planar TDWs. PMID:28220893

  13. General planar transverse domain walls realized by optimized transverse magnetic field pulses in magnetic biaxial nanowires.

    PubMed

    Li, Mei; Wang, Jianbo; Lu, Jie

    2017-02-21

    The statics and field-driven dynamics of transverse domain walls (TDWs) in magnetic nanowires (NWs) have attracted continuous interests because of their theoretical significance and application potential in future magnetic logic and memory devices. Recent results demonstrate that uniform transverse magnetic fields (TMFs) can greatly enhance the wall velocity, meantime leave a twisting in the TDW azimuthal distribution. For application in high-density NW devices, it is preferable to erase the twisting so as to minimize magnetization frustrations. Here we report the realization of a completely planar TDW with arbitrary tilting attitude in a magnetic biaxial NW under a TMF pulse with fixed strength and well-designed orientation profile. We smooth any twisting in the TDW azimuthal plane thus completely decouple the polar and azimuthal degrees of freedom. The analytical differential equation describing the polar angle distribution is derived and the resulting solution is not the Walker-ansatz form. With this TMF pulse comoving, the field-driven dynamics of the planar TDW is investigated with the help of the asymptotic expansion method. It turns out the comoving TMF pulse increases the wall velocity under the same axial driving field. These results will help to design a series of modern magnetic devices based on planar TDWs.

  14. Earthquake Stress Drop in Rupture Patches and Rupture Barriers on Gofar Transform Fault, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Moyer, P. A.; Boettcher, M. S.; McGuire, J. J.; Collins, J. A.

    2014-12-01

    The largest earthquakes on mid-ocean ridge transform faults (RTFs) exhibit the most systematic behaviors known in seismology. On the fast slipping Gofar transform fault on the East Pacific Rise (EPR), Mw ~6.0 earthquakes occur every ~5 years and repeatedly rupture the same asperities (fault patches), suggesting that the intervening fault segments (rupture barriers) stop the propagation of the largest earthquakes. In 2008, an ocean bottom seismometer (OBS) deployment captured the end of a seismic cycle on Gofar transform fault [McGuire et al., 2012]. We determine stress drop for earthquakes recorded during this experiment to investigate how the source properties of moderate sized earthquakes (3.0 < Mw < 5.5) differ between the rupture patch and rupture barrier fault segments. The OBS experiment on Gofar transform fault recorded an extensive foreshock sequence localized within a 10 km rupture barrier, the Mw 6.0 mainshock and its aftershocks that occurred in a ~10 km rupture patch, and an earthquake swarm that was located in a second rupture barrier adjacent to the ridge-transform intersection. Using waveforms recorded with a sample rate of 50 Hz on the OBS accelerometers, we calculate stress drop using the Madariaga [1976] circular crack model, with the corner frequency derived from an empirical Green's function (EGF) method, and seismic moment obtained by fitting an omega-squared source model to the low frequency amplitude of individual event spectra. Results for ~300 earthquakes in the foreshock, aftershock, and swarm zones have a range of stress drops from 0.2 to 50 MPa. Values for the best constrained 10% of earthquakes show a weighted average stress drop in the aftershock zone that is more than twice the weighted average stress drop in the foreshock zone (3.5 MPa and 1.1 MPa, respectively). These variations in earthquake stress drop reflect systematic differences in along strike fault zone properties between rupture patches and rupture barriers on Gofar

  15. Triggered reverse fault and earthquake due to crustal unloading, northwest Transverse Ranges, California.

    USGS Publications Warehouse

    Yerkes, R.F.; Ellsworth, W.L.; Tinsley, J.C.

    1983-01-01

    A reverse-right-oblique surface rupture, associated with a ML 2.5 earthquake, formed in a diatomite quarry near Lompoc, California, in the northwesternmost Transverse Ranges on April 7, 1981. The 575-m-long narrow zone of ruptures formed in clay interbeds in diatomite and diatomaceous shale of the Neogene Monterey Formation. The ruptures parallel bedding, dip 39o-59oS, and trend about N84oE on the north limb of an open symmetrical syncline. Maximum net slip was 25 cm; maximum reverse dip slip was 23 cm, maximum right-lateral strike slip was about 9 cm, and average net slip was about 12 cm. The seismic moment of the earthquake is estimated at 1 to 2 X 1018 dyne/cm and the static stress drop at about 3 bar. The removal of an average of about 44 m of diatomite resulted in an average load reduction of about 5 bar, which decreased the normal stress by about 3.5 bar and increased the shear stress on the tilted bedding plane by about 2 bar. The April 7, 1981, event was a very shallow bedding-plane rupture, apparently triggered by crustal unloading. -Authors

  16. Triggered reverse fault and earthquake due to crustal unloading, northwest Transverse Ranges, California

    NASA Astrophysics Data System (ADS)

    Yerkes, R. F.; Ellsworth, W. L.; Tinsley, J. C.

    1983-05-01

    A reverse-right-oblique surface rupture, associated with a ML 2.5 earthquake, formed in a diatomite quarry near Lompoc, California, in the northwesternmost Transverse Ranges on April 7, 1981. The 575-m-long narrow zone of ruptures formed in clay interbeds in diatomite and diatomaceous shale of the Neogene Monterey Formation. The ruptures parallel bedding, dip 39° 59°S, and trend about N84°E on the north limb of an open symmetrical syncline. Maximum net slip was 25 cm; maximum reverse dip slip was 23 cm, maximum right-lateral strike slip was about 9 cm, and average net slip was about 12 cm. The seismic moment of the earthquake is estimated at 1 to 2 × 1018 dyne/cm and the static stress drop at about 3 bar. The removal of an average of about 44 m of diatomite resulted in an average load reduction of about 5 bar, which decreased the normal stress by about 3.5 bar and increased the shear stress on the tilted bedding plane by about 2 bar. The April 7,1981, event was a very shallow bedding-plane rupture, apparently triggered by crustal unloading.

  17. Dynamic fault rupture model of the 2008 Iwate-Miyagi Nairiku earthquake, Japan; Role of rupture velocity changes on extreme ground motions

    NASA Astrophysics Data System (ADS)

    Pulido Hernandez, N. E.; Dalguer Gudiel, L. A.; Aoi, S.

    2009-12-01

    The Iwate-Miyagi Nairiku earthquake, a reverse earthquake occurred in the southern Iwate prefecture Japan (2008/6/14), produced the largest peak ground acceleration recorded to date (4g) (Aoi et al. 2008), at the West Ichinoseki (IWTH25), KiK-net strong motion station of NIED. This station which is equipped with surface and borehole accelerometers (GL-260), also recorded very high peak accelerations up to 1g at the borehole level, despite being located in a rock site. From comparison of spectrograms of the observed surface and borehole records at IWTH25, Pulido et. al (2008) identified two high frequency (HF) ground motion events located at 4.5s and 6.3s originating at the source, which likely derived in the extreme observed accelerations of 3.9g and 3.5g at IWTH25. In order to understand the generation mechanism of these HF events we performed a dynamic fault rupture model of the Iwate-Miyagi Nairiku earthquake by using the Support Operator Rupture Dynamics (SORD) code, (Ely et al., 2009). SORD solves the elastodynamic equation using a generalized finite difference method that can utilize meshes of arbitrary structure and is capable of handling geometries appropriate to thrust earthquakes. Our spontaneous dynamic rupture model of the Iwate-Miyagi Nairiku earthquake is governed by the simple slip weakening friction law. The dynamic parameters, stress drop, strength excess and critical slip weakening distance are estimated following the procedure described in Pulido and Dalguer (2009) [PD09]. These parameters develop earthquake rupture consistent with the final slip obtained by kinematic source inversion of near source strong ground motion recordings. The dislocation model of this earthquake is characterized by a patch of large slip located ~7 km south of the hypocenter (Suzuki et al. 2009). Our results for the calculation of stress drop follow a similar pattern. Using the rupture times obtained from the dynamic model of the Iwate-Miyagi Nairiku earthquake we

  18. Are rupture zone limits of great subduction earthquakes controlled by upper plate structures? Evidence from multichannel seismic reflection data acquired across the northern Ecuador-southwest Colombia margin

    NASA Astrophysics Data System (ADS)

    Collot, Jean-Yves; Marcaillou, Boris; Sage, FrançOise; Michaud, FrançOis; Agudelo, William; Charvis, Philippe; Graindorge, David; Gutscher, Marc-André; Spence, George

    2004-11-01

    Subduction of the Nazca plate beneath the Ecuador-Colombia margin has produced four megathrust earthquakes during the last century. The 500-km-long rupture zone of the 1906 (Mw = 8.8) event was partially reactivated by three thrust events, in 1942 (Mw = 7.8), 1958 (Mw = 7.7), and 1979 (Mw = 8.2), whose rupture zones abut one another. Multichannel seismic reflection and bathymetric data acquired during the SISTEUR cruise show evidence that the margin wedge is segmented by transverse crustal faults that potentially correlate with the limits of the earthquake coseismic slip zones. The Paleogene-Neogene Jama Quininde and Esmeraldas crustal faults define a ˜200-km-long margin crustal block that coincides with the 1942 earthquake rupture zone. Subduction of the buoyant Carnegie Ridge is inferred to partially lock the plate interface along central Ecuador. However, coseismic slip during the 1942 and 1906 earthquakes may have terminated against the subducted northern flank of the ridge. We report on a newly identified Manglares crustal fault that cuts transversally through the margin wedge and correlates with the limit between the 1958 and 1979 rupture zones. During the earthquake cycle the fault is associated with high-stress concentration on the plate interface. An outer basement high, which bounds the margin seaward of the 1958 rupture zone, may act as a deformable buttress to seaward propagation of coseismic slip along a megathrust splay fault. Coseismic uplift of the basement high is interpreted as the cause for the 1958 tsunami. We propose a model of weak transverse faults which reduce coupling between adjacent margin segments, together with a splay fault and an asperity along the plate interface as controlling the seismogenic rupture of the 1958 earthquake.

  19. 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

  20. 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.

  1. Validation of the rupture properties of the 2001 Kunlun, China (Ms = 8.1), earthquake from seismological and geological observations

    USGS Publications Warehouse

    Wen, Y.-Y.; Ma, K.-F.; Song, T.R.-A.; Mooney, W.D.

    2009-01-01

    We determine the finite-fault slip distribution of the 2001 Kunlun earthquake (Ms = 8.1) by inverting teleseismic waveforms, as constrained by geological and remote sensing field observations. The spatial slip distribution along the 400-km-long fault was divided into five segments in accordance with geological observations. Forward modelling of regional surface waves was performed to estimate the variation of the speed of rupture propagation during faulting. For our modelling, the regional 1-D velocity structure was carefully constructed for each of six regional seismic stations using three events with magnitudes of 5.1-5.4 distributed along the ruptured portion of the Kunlun fault. Our result shows that the average rupture velocity is about 3.6 km s-1, consistent with teleseismic long period wave modelling. The initial rupture was almost purely strike-slip with a rupture velocity of 1.9 km s-1, increasing to 3.5 km s-1 in the second fault segment, and reaching a rupture velocity of about 6 km s-1 in the third segment and the fourth segment, where the maximum surface offset, with a broad fault zone, was observed. The rupture velocity decelerated to a value of 3.3 km s-1 in the fifth and final segment. Coseismic slip on the fault was concentrated between the surface and a depth of about 10 km. We infer that significant variations in rupture velocity and the observed fault segmentation are indicative of variations in strength along the interface of the Kunlun fault, as well as variations in fault geometry. ?? 2009 The Authors Journal compilation ?? 2009 RAS.

  2. Star polymers rupture induced by constant forces.

    PubMed

    García, N A; Febbo, M; Vega, D A; Milchev, A

    2014-10-28

    In this work, we study the breakage process of an unknotted three-arm star-shaped polymer when it is pulled from its free ends by a constant force. The star polymer configuration is described through an array of monomers coupled by anharmonic bonds, while the rupture process is tracked in three-dimensional space by means of Langevin Molecular Dynamics simulations. The interaction between monomers is described by a Morse potential, while a Weeks-Chandler-Anderson energetic contribution accounts for the excluded volume interaction. We explore the effect of the molecular architecture on the distributions of rupture times over a broad interval of pulling forces and star configurations. It was found that the rupture time distribution of the individual star arms is strongly affected by the star configuration imposed by the pulling forces and the length of the arms. We also observed that for large pulling forces the rupture time distributions resemble the dominant features observed for linear polymer chains. The model introduced here provides the basic ingredients to describe the effects of tensile forces on stress-induced degradation of branched macromolecules and polymer networks.

  3. Plantar fascia rupture associated with corticosteroid injection.

    PubMed

    Sellman, J R

    1994-07-01

    A series of 37 patients, all with a presumptive diagnosis of plantar fascia rupture, is presented. All had had prior heel pain diagnosed as plantar fasciitis, and all had been treated with corticosteroid injection into the calcaneal origin of the fascia. One third described a sudden tearing episode in the heel, while the rest had a gradual change in symptoms. Most of the patients had relief of the original heel pain, which had been replaced by a variety of new foot problems, including dorsal and lateral midfoot pain, swelling, foot weakness, metatarsal pain, and metatarsal fracture. In all 37 patients, there was a palpable diminution in the tension of the plantar fascia on the involved side, and footprints often showed a flattening of the involved arch. Magnetic resonance imaging done on one patient showed attenuation of the plantar fascia. From these observations and data, the author concluded that plantar fascia rupture had occurred. Treatment following rupture included supportive shoes, orthoses, and time. The majority had resolution of their new symptoms, but this often took 6 to 12 months to occur. In the remainder, there were persisting symptoms. Corticosteroid injections, although helpful in the treatment of plantar fasciitis, appear to predispose to plantar fascia rupture.

  4. Fatigue crack propagation analysis of plaque rupture.

    PubMed

    Pei, Xuan; Wu, Baijian; Li, Zhi-Yong

    2013-10-01

    Rupture of atheromatous plaque is the major cause of stroke or heart attack. Considering that the cardiovascular system is a classic fatigue environment, plaque rupture was treated as a chronic fatigue crack growth process in this study. Fracture mechanics theory was introduced to describe the stress status at the crack tip and Paris' law was used to calculate the crack growth rate. The effect of anatomical variation of an idealized plaque cross-section model was investigated. The crack initiation was considered to be either at the maximum circumferential stress location or at any other possible locations around the lumen. Although the crack automatically initialized at the maximum circumferential stress location usually propagated faster than others, it was not necessarily the most critical location where the fatigue life reached its minimum. We found that the fatigue life was minimum for cracks initialized in the following three regions: the midcap zone, the shoulder zone, and the backside zone. The anatomical variation has a significant influence on the fatigue life. Either a decrease in cap thickness or an increase in lipid pool size resulted in a significant decrease in fatigue life. Comparing to the previously used stress analysis, this fatigue model provides some possible explanations of plaque rupture at a low stress level in a pulsatile cardiovascular environment, and the method proposed here may be useful for further investigation of the mechanism of plaque rupture based on in vivo patient data.

  5. Musculotendinous infraspinatus rupture and shoulder weakness.

    PubMed

    Lipford, Melissa C; Bond, Jeffrey R; Steinmann, Scott P; Kumar, Neeraj

    2011-12-01

    We report a patient with bilateral simultaneous onset of weakness of shoulder lateral rotation due to musculotendinous infraspinatus rupture that occurred after shoulder steroid injections. Disruption of the musculotendinous junction of the infraspinatus is a rare recently described entity. Electromyography is normal, and magnetic resonance image findings are characteristic.

  6. Bond-rupture immunosensors--a review.

    PubMed

    Hirst, Evan R; Yuan, Yong J; Xu, W L; Bronlund, J E

    2008-07-15

    It has long been the goal of researchers to develop fast and reliable point-of-care alternatives to existing lab-based tests. A viable point-of-care biosensor is fast, reliable, simple, cost-effective, and detects low concentrations of the target analyte. The target of biosensors is biological such as bacteria or virus and as such, the antibody-antigen bond derived from the real immune response is used. Biosensor applications include lab-based tests for the purposes of diagnostics, drug discovery, and research. Additional applications include environmental, food, and agricultural monitoring. The main merits of the bond-rupture method are quick, simple, and capable of discriminating between specific and non-specific interactions. The separation of specific and non-specific bonds is important for working in real-life complex serums such as blood. The bond-rupture technique can provide both qualitative results, the detection of a target, and quantitative results, the concentration of target. Bond-rupture achieves this by a label-free method requiring no pre-processing of the analyte. A piezoelectric transducer such as the quartz crystal microbalance (QCM) shakes the bound particles free from the surface. Other transducers such as Surface Acoustic Wave (SAW) are also considered. The rupture of the bonds is detected as electronic noise. This review article links diverse research areas to build a picture of a field still in development.

  7. Phenomenological extraction of Transverse Momentum Dependent distributions

    SciTech Connect

    Prokudin, Alexei

    2011-10-24

    We discuss phenomenological extraction of Transverse Momentum Dependent Distributions (TMDs) from experimental data. At leading twist spin structure of spin-1/2 hadron can be described by 8 TMDs. TMDs reveal three-dimensional distribution of partons inside polarised nucleon. Experimentally these functions can be studied in polarised experiments using Spin Asymmetries in particular Single Spin Asymmetries (SSAs). We discuss transversity that measures distribution of transversely polarised quarks in a transversely polarised nucleon and Sivers distribution function that describes distribution of unpolarised quarks in a transversely polarised nucleon.

  8. Electron Ion Collider transverse spin physics

    SciTech Connect

    Prokudin, Alexei

    2011-07-01

    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

  9. Electron Ion Collider transverse spin physics

    SciTech Connect

    Prokudin, Alexei

    2011-07-15

    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.

  10. A case report: spontaneous rupture of dissecting aneurysm of the middle colic artery.

    PubMed

    Chino, Osamu; Kijima, Hiroshi; Shibuya, Makoto; Yamamoto, Soichiro; Kashiwagi, Hiroyuki; Kondo, Yasumasa; Makuuchi, Hiroyasu

    2004-12-01

    Aneurysms of the superior mesenteric artery branches are rarely reported, even among them colic artery aneurysms are seldom. We report a case of 78-year-old male with ruptured dissecting aneurysm of middle colic artery. The patient complained abdominal pain and nausea during hospital stay for renal stone. The patient suddenly developed severe abdominal pain, leading to shock. He underwent emergency surgery under a preoperative diagnosis of intraperitoneal hemorrhage. At exploratory laparotomy, a large hematoma involving the mesentery root of the transverse colon was associated with a ruptured aneurysm measuring 15 x 10 mm in size, which was located to the mid-portion of middle colic artery. Right-hemicolectomy was carried out because of ischemic changes in the ascending colon. Histological examination demonstrated a ruptured dissecting aneurysm of the middle colic artery approximately 5 cm in length, associated with destruction of the tunica interna and media. The aneurysm was thought to result from idiopathic segmental arterial mediolysis, because no definitive evidence of atherosclerosis or arteritis was observed.

  11. Vaginal birth after cesarean section: risk of uterine rupture with labor induction.

    PubMed

    Ouzounian, Joseph G; Miller, David A; Hiebert, Christy J; Battista, Leah R; Lee, Richard H

    2011-09-01

    We assessed the rate of uterine rupture in patients undergoing labor induction for attempted vaginal birth after cesarean (VBAC). A retrospective study was performed of data from a computerized database. Deliveries from January 1, 1998, to June 30, 2001, in the Southern California Kaiser Permanente system were reviewed and various perinatal characteristics analyzed. A total of 16,218 patients had a prior low transverse cesarean section. Of these, 6832 (42.1%) had a trial of labor. Successful VBAC occurred in 86% of patients with spontaneous onset of labor and 66% of patients with labor induction ( p < 0.001). The uterine rupture rate was not different between patients with spontaneous or induced labor (1.0% versus 1.2%, p = 0.51). Similarly, there was no significant difference between oxytocin or prostaglandin E2 induction (1.4% versus 1.0%, p = 0.59). In our study, labor induction did not appear to increase the risk of uterine rupture in women attempting VBAC.

  12. Physically Based Failure Criteria for Transverse Matrix Cracking

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Camanho, Pedro P.

    2003-01-01

    A criterion for matrix failure of laminated composite plies in transverse tension and in-plane shear is developed by examining the mechanics of transverse matrix crack growth. Matrix cracks are assumed to initiate from manufacturing defects and can propagate within planes parallel to the fiber direction and normal to the ply mid-plane. Fracture mechanics models of cracks in unidirectional laminates, embedded plies and outer plies are developed to determine the onset and direction of propagation for unstable crack growth. The models for each ply configuration relate ply thickness and ply toughness to the corresponding in-situ ply strength. Calculated results for several materials are shown to correlate well with experimental results.

  13. Investigation of transverse oscillation method.

    PubMed

    Udesen, Jesper; Jensen, Jørgen Arendt

    2006-05-01

    Conventional ultrasound scanners can display only the axial component of the blood velocity vector, which is a significant limitation when vessels nearly parallel to the skin surface are scanned. The transverse oscillation (TO) method overcomes this limitation by introducing a TO and an axial oscillation in the pulse echo field. The theory behind the creation of the double oscillation pulse echo field is explained as well as the theory behind the estimation of the vector velocity. A parameter study of the method is performed, using the ultrasound simulation program Field II. A virtual linear-array transducer with center frequency 7 MHz and 128 active elements is created, and a virtual blood vessel of radius 6.4 mm is simulated. The performance of the TO method is found around an initial point in the parameter space. The parameters varied are: flow angle, transmit focus depth, receive apodization, pulse length, transverse wave length, number of emissions, signal-to-noise ratio (SNR), and type of echo-canceling filter used. Using an experimental scanner, the performance of the TO method is evaluated. An experimental flowrig is used to create laminar parabolic flow in a blood mimicking fluid, and the fluid is scanned under different flow-to-beam angles. The relative standard deviation on the transverse velocity estimate is found to be less than 10% for all angles between 50 degrees and 90 degrees. Furthermore, the TO method is evaluated in the flowrig using pulsatile flow, which resembles the flow in the femoral artery. The estimated volume flow as a function of time is compared to the volume flow derived from a conventional axial method at a flow-to-beam angle of 60 degrees. It is found that the method is highly sensitive to the angle between the flow and the beam direction. Also, the choice of echo canceling filter affects the performance significantly.

  14. Optical Isolators With Transverse Magnets

    NASA Technical Reports Server (NTRS)

    Fan, Yuan X.; Byer, Robert L.

    1991-01-01

    New design for isolator includes zigzag, forward-and-backward-pass beam path and use of transverse rather than longitudinal magnetic field. Design choices produce isolator with as large an aperture as desired using low-Verdet-constant glass rather than more expensive crystals. Uses commercially available permanent magnets in Faraday rotator. More compact and less expensive. Designed to transmit rectangular beam. Square cross section of beam extended to rectangular shape by increasing one dimension of glass without having to increase magnetic field. Potentially useful in laser systems involving slab lasers and amplifiers. Has applications to study of very-high-power lasers for fusion research.

  15. 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.

  16. Quantification of Ground Motion Reductions by Fault Zone Plasticity with 3D Spontaneous Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cui, Y.; Day, S. M.

    2015-12-01

    We explore the effects of fault zone nonlinearity on peak ground velocities (PGVs) by simulating a suite of surface rupturing earthquakes in a visco-plastic medium. Our simulations, performed with the AWP-ODC 3D finite difference code, cover magnitudes from 6.5 to 8.0, with several realizations of the stochastic stress drop for a given magnitude. We test three different models of rock strength, with friction angles and cohesions based on criteria which are frequently applied to fractured rock masses in civil engineering and mining. We use a minimum shear-wave velocity of 500 m/s and a maximum frequency of 1 Hz. In rupture scenarios with average stress drop (~3.5 MPa), plastic yielding reduces near-fault PGVs by 15 to 30% in pre-fractured, low-strength rock, but less than 1% in massive, high quality rock. These reductions are almost insensitive to the scenario earthquake magnitude. In the case of high stress drop (~7 MPa), however, plasticity reduces near-fault PGVs by 38 to 45% in rocks of low strength and by 5 to 15% in rocks of high strength. Because plasticity reduces slip rates and static slip near the surface, these effects can partially be captured by defining a shallow velocity-strengthening layer. We also perform a dynamic nonlinear simulation of a high stress drop M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. With respect to the viscoelastic solution (a), nonlinearity in the fault damage zone and in near-surface deposits would reduce long-period (> 1 s) peak ground velocities in the Los Angeles basin by 15-50% (b), depending on the strength of crustal rocks and shallow sediments. These simulation results suggest that nonlinear effects may be relevant even at long periods, especially for earthquakes with high stress drop.

  17. Floating patella: combined quadriceps tendon, retinacula, and patellar tendon ruptures in a high-performance elite athlete.

    PubMed

    Langer, Phillip R; Selesnick, F Harlan

    2010-09-01

    Simultaneous quadriceps and patellar tendon rupture is rare. To our knowledge, we present the first known case of simultaneous quadriceps tendon, patella tendon, and retinacula rupture in the ipsilateral knee of a high-performance elite athlete. This disabling injury in the active person results in an inability to actively obtain and maintain full knee extension. When the tendons do not heal properly, at the correct length and tension, knee range of motion and strength can become significantly altered, leading to early fatigue, patellofemoral pain, and possibly instability, preventing return to preinjury status. Immediate surgical repair is recommended for optimal return of knee function and power.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. A molecular scale perspective: Monte Carlo simulation for rupturing of ultra thin polymer film melts

    NASA Astrophysics Data System (ADS)

    Singh, Satya Pal

    2017-04-01

    Monte Carlo simulation has been performed to study the rupturing process of thin polymer film under strong confinement. The change in mean square displacement; pair correlation function; density distribution; average bond length and microscopic viscosity are sampled by varying the molecular interaction parameters such as the strength and the equilibrium positions of the bonding, non-bonding potentials and the sizes of the beads. The variation in mean square angular displacement χθ = [ < Δθ2 > - < Δθ>2 ] fits very well to a function of type y (t) = A + B *e-t/τ. This may help to study the viscous properties of the films and its dependence on different parameters. The ultra thin film annealed at high temperature gets ruptured and holes are created in the film mimicking spinodal dewetting. The pair correlation function and density profile reveal rich information about the equilibrium structure of the film. The strength and equilibrium bond length of finite extensible non-linear elastic potential (FENE) and non-bonding Morse potential have clear impact on microscopic rupturing of the film. The beads show Rouse or repetition motion forming rim like structures near the holes created inside the film. The higher order interaction as dipole-quadrupole may get prominence under strong confinement. The enhanced excluded volume interaction under strong confinement may overlap with the molecular dispersion forces. It can work to reorganize the molecules at the bottom of the scale and can imprint its signature in complex patterns evolved.

  3. Strength and conductivity of unidirectional copper composites reinforced by continuous SiC fibers

    NASA Astrophysics Data System (ADS)

    Kimmig, S.; Allen, I.; You, J. H.

    2013-09-01

    A SiC long fiber-reinforced copper composite offers a beneficial combination of high strength and high thermal conductivity at elevated temperatures. Both properties make the composite a promising material for the heat sink of high-heat-flux components. In this work, we developed a novel Cu/SiCf composite using the Sigma fiber. Based on HIP technique, a metallurgical process was established for fabricating high quality specimens using a TiC interface coating. Extensive tensile tests were conducted on the unidirectionally reinforced composite at 20 °C and 300 °C for a wide range of fiber volume fraction (Vf). In this paper, a large amount of test data is presented. The transversal thermal conductivity varies from 260 to 130 W/mK at 500 °C as Vf is increased from 13% to 37%. The tensile strength reached up to 1246 MPa at 20 °C for Vf = 37.6%, where the fracture strain was limited to 0.8%. The data of both elastic modulus and ultimate strength exhibited a good agreement with the rule-of-mixture predictions indicating a high quality of the materials. The strength of the composite with the Sigma fibers turned out to be superior to those of the SCS6 fibers at 300 °C, although the SCS6 fiber actually has a higher strength than the Sigma fiber. The fractographic pictures of tension test and fiber push-out test manifested a sufficient interfacial bonding. Unidirectional copper composite reinforced by long SiC fibers was fabricated using the Sigma SM1140+ fiber for a wide range of fiber volume fraction from 14% to 40%. Extensive tensile tests were carried out at RT and 300 °C. The data of ultimate strength as well as elastic modulus exhibited a good agreement with the rule-of-mixture predictions indicating a high quality of the materials. In terms of the tensile strength, the Cu/Sigma composite turned out to be superior to the previous Cu/SCS6 composite at 300 °C, while comparable at RT, although the SCS6 fiber has a higher strength than the Sigma fiber. Such a

  4. 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.

  5. Delamination behaviour of GdBCO coated conductor tapes under transverse tension

    NASA Astrophysics Data System (ADS)

    Gorospe, A.; Nisay, A.; Dizon, J. R.; Shin, H. S.

    2013-11-01

    The electromechanical property behaviour of 2G coated conductor (CC) tapes fabricated by multi-layer deposition process both in the in-plane and transverse direction should be understood. The CC tapes are used in the fabrication of epoxy resin-impregnated coils. In such case, the Lorentz force due to the high magnetic field applied as well as the thermal stress due to the difference in coefficient of thermal expansion (CTE) among constituent layers during cooling to cryogenic temperature will induce transversely applied load to the surface of CC tapes in coils. Hence, the CC tape should have a good mechanical property in the transverse direction in order to maintain its superior performance under magnetic field. In this study, a test frame which gives precisely aligned transverse load was devised. Using the fixture, the delamination behaviours including the delamination strength of the GdBCO CC tapes under transverse tensile loading were investigated. Large variation on the delamination strength of the CC tapes was recorded and might have resulted from the slit edge effect and the inhomogeneity of the CC tapes. The Ic degradation behaviour under transverse load was related to the location where delamination occurred in the sample.

  6. Advanced analysis of the transverse bulkhead of the a general cargo ship

    NASA Astrophysics Data System (ADS)

    Axinte, T.; Nutu, C.; Stanca, C.; Cupsa, O.; Carp, A.

    2016-08-01

    The paper presents the main strength factors stressing the transverse bulkhead of a cargo ship. The transverse bulkhead is one of the main components of the hull for a general cargo vessel. There are presented the role and the importance of the general cargo vessel's type using an original drawing made in NX 8.0 Software from Siemens. Further on, we are presented the importance of the transverse bulkhead of the general cargo ship's hull. Next there are analysed the formability of the transverse bulkhead's material and then we are determining the shear, normal and von Mises stresses in the traverse bulkhead, using the finite element method. Once the stresses are computed, there are also determined the fatigue life, strength safety factor and fatigue safety factor. The analysis of the transverse bulkhead is important for the safety of the general cargo vessel type because if this component of the ship does not resist to the various stresses and high deformations during bad storms on the sea or if the cargo is stored inappropriately, deformations or even breakage of the transverse bulkhead can occur, thus causing damages of the cargo ship, especially under heavy storm.

  7. Rupture Process During the 2015 Illapel, Chile Earthquake: Zigzag-Along-Dip Rupture Episodes

    NASA Astrophysics Data System (ADS)

    Okuwaki, Ryo; Yagi, Yuji; Aránguiz, Rafael; González, Juan; González, Gabriel

    2016-04-01

    We constructed a seismic source model for the 2015 M W 8.3 Illapel, Chile earthquake, which was carried out with the kinematic waveform inversion method adopting a novel inversion formulation that takes into account the uncertainty in the Green's function, together with the hybrid backprojection method enabling us to track the spatiotemporal distribution of high-frequency (0.3-2.0 Hz) sources at high resolution by using globally observed teleseismic P-waveforms. A maximum slip amounted to 10.4 m in the shallow part of the seismic source region centered 72 km northwest of the epicenter and generated a following tsunami inundated along the coast. In a gross sense, the rupture front propagated almost unilaterally to northward from the hypocenter at <2 km/s, however, in detail the spatiotemporal slip distribution also showed a complex rupture propagation pattern: two up-dip rupture propagation episodes, and a secondary rupture episode may have been triggered by the strong high-frequency radiation event at the down-dip edge of the seismic source region. High-frequency sources tends to be distributed at deeper parts of the slip area, a pattern also documented in other subduction zone megathrust earthquakes that may reflect the heterogeneous distribution of fracture energy or stress drop along the fault. The weak excitation of high-frequency radiation at the termination of rupture may represent the gradual deceleration of rupture velocity at the transition zone of frictional property or stress state between the megathrust rupture zone and the swarm area.

  8. 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.

  9. Detection of supershear rupture in 2013 Craig, Alaska, earthquake

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-01-01

    Seismic ruptures are akin to opening a zipper—a gap in the crust starts in one location and travels along the fault in a particular direction. When a strained fault ruptures in an earthquake, seismic waves also spread out from the epicenter. In some cases, the waves' passage can trigger the initiation of a new rupture ahead of the initial expanding rupture in locked portions of the fault. If the triggered rupture grows successfully, the overall rupture front can then outpace the passage of the shear waves, secondary seismic waves that travel slowly after the earthquake begins and are responsible for the bulk of violent shaking. These earthquakes display what is known as supershear rupture; only seven such earthquakes have previously been recorded.

  10. [Proximal and distal rupture of the m. biceps brachii].

    PubMed

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  11. 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.

  12. Transitions, transversions, and the molecular evolutionary clock.

    PubMed

    Jukes, T H

    1987-01-01

    Nucleotide substitutions in the form of transitions (purine-purine or pyrimidine-pyrimidine interchanges) and transversions (purine-pyrimidine interchanges) occur during evolution and may be compiled by aligning the sequences of homologous genes. Referring to the genetic code tables, silent transitions take place in third positions of codons in family boxes and two-codon sets. Silent transversions in third positions occur only in family boxes, except for A = C transversions between AGR and CGR arginine codons (R = A or G). Comparisons of several protein genes have been made, and various subclasses of transitional and transversional nucleotide substitutions have been compiled. Considerable variations occur among the relative proportions of transitions and transversions. Such variations could possibly be caused by mutator genes, favoring either transitions or, conversely, transversions, during DNA replication. At earlier stages of evolutionary divergence, transitions are usually more frequent, but there are exceptions. No indication was found that transversions usually originate from multiple substitutions in transitions.

  13. Blunt Cardiac Rupture: A Diagnostic Challenge

    PubMed Central

    Kumar, Vineet; Dharap, Satish Balkrishna

    2016-01-01

    Blunt Cardiac Rupture (BCR) is a life threatening injury. Majority of patients do not reach the hospital and in those who reach the emergency department, timely diagnosis and treatment is a challenge. The case is about a patient with multiple blunt injuries who presented in shock. Cardiac tamponade was suspected on clinical grounds and on evidence of mediastinal widening on radiograph. In the absence of songography, the diagnosis was confirmed by subxiphoid pericardial window. Emergency thoracotomy revealed a right atrial appendage rupture which was surgically corrected. The patient also underwent splenectomy for grade IV splenic injury. Liver injury, pubic diastasis and tibial spine avulsion fracture was managed conservatively. He recovered well. Systematic observance of trauma resuscitation guidelines can help salvage patients with life threatening complex injuries even in the absence of specialized imaging investigations. PMID:28050441

  14. Liquid salt environment stress-rupture testing

    DOEpatents

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  15. Rupture rudimentary horn pregnancy at 31 week

    PubMed Central

    Al Qarni, Abdullah A.; Al-Braikan, Nawal; Al-Hanbali, Moh’d M.; Alharmaly, Abdullah H.

    2017-01-01

    Rudimentary horn could be a rare congenital uterine anomalies result from incomplete fusion of the 2 Müllerian ducts throughout embryo-genesis. Pregnancy in an exceedingly rudimentary horn is rare and typically terminates in rupture throughout the late of first or second trimester of pregnancy. We tend to present a rare case of a gravida within the trimester (31 weeks) presented with complain of abdominal pain, nausea, and vomit for 3 days. On presentation, the patient was pale and irritable. Ultrasound scan showed fetus at (30 weeks) with cardiac activity. Cardiotocography reactive. Incision showed horned uterus with pregnancy in rudimentary left horn that was ruptured. Alive fetus was delivered. The rudimentary left horn was excised. The patient was advised to not get pregnant for 3 years. Within one year, the patient came to hospital in active labor at (37 weeks). This case emphasizes the importance of fine antepartum care to avoid morbidity and mortality. PMID:28133695

  16. Rupture rudimentary horn pregnancy at 31 week.

    PubMed

    Al Qarni, Abdullah A; Al-Braikan, Nawal; Al-Hanbali, Moh'd M; Alharmaly, Abdullah H

    2017-02-01

    Rudimentary horn could be a rare congenital uterine anomalies result from incomplete fusion of the two Müllerian ducts throughout embryo-genesis. Pregnancy in an exceedingly rudimentary horn is rare and typically terminates in rupture throughout the late of first or second trimester of pregnancy. We tend to present a rare case of a gravida within the trimester (31 weeks) presented with complain of abdominal pain, nausea, and vomit for 3 days. On presentation, the patient was pale and irritable. Ultrasound scan showed fetus at (30 weeks) with cardiac activity. Cardiotocography reactive. Incision showed horned uterus with pregnancy in rudimentary left horn that was ruptured. Alive fetus was delivered. The rudimentary left horn was excised. The patient was advised to not get pregnant for 3 years. Within one year, the patient came to hospital in active labor at (37 weeks). This case emphasizes the importance of fine antepartum care to avoid morbidity and mortality.

  17. Transverse section radionuclide scanning system

    DOEpatents

    Kuhl, David E.; Edwards, Roy Q.

    1976-01-01

    This invention provides a transverse section radionuclide scanning system for high-sensitivity quantification of brain radioactivity in cross-section picture format in order to permit accurate assessment of regional brain function localized in three-dimensions. High sensitivity crucially depends on overcoming the heretofore known raster type scanning, which requires back and forth detector movement involving dead-time or partial enclosure of the scan field. Accordingly, this invention provides a detector array having no back and forth movement by interlaced detectors that enclose the scan field and rotate as an integral unit around one axis of rotation in a slip ring that continuously transmits the detector data by means of laser emitting diodes, with the advantages that increased amounts of data can be continuously collected, processed and displayed with increased sensitivity according to a suitable computer program.

  18. 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.

  19. Transverse patterning and human amnesia.

    PubMed

    Rickard, Timothy C; Verfaellie, Mieke; Grafman, Jordan

    2006-10-01

    The transverse patterning (TP) task (A+ B-, B+ C-, C+ A-) has played a central role in testing the hypothesis that medial-temporal (and, in particular, hippocampal) brain damage selectively impairs learning on at least some classes of configural (i.e., nonlinear) learning tasks. Results in the animal and human literature generally support that hypothesis. Reed and Squire [Impaired transverse patterning in human amnesia is a special case of impaired memory for two-choice discrimination tasks. Behavioral Neuroscience, 113, 3-9, 1999], however, advanced an alternative account in which impaired TP performance in amnesia reflects a generic scaling artifact arising from the greater difficulty of the TP task compared to the elemental (i.e., linear) control task that is typically used. We begin with a critique of Reed and Squire, countering their conceptual arguments and showing that their results, when analyzed appropriately, support the configural deficit hypothesis. We then report results from eight new amnesic patients and controls on an improved version of the TP task. Despite substantial practice, accuracy of patients with bilateral hippocampal damage due to anoxia reached and maintained an asymptote of only 54% correct, well below the maximum accuracy obtainable (67%) in the absence of configural learning. A patient with selective bilateral damage to the anterior thalamic nuclei exhibited a TP accuracy asymptote that was near 67%, a pattern of two out of three correct consecutive trials, and a pattern of nearly always answering correctly for two of the three TP item pairs. These results are consistent with a set of unique and parameter-free predictions of the configural deficit hypothesis.

  20. 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

  1. Wrapped Wire Detects Rupture Of Pressure Vessel

    NASA Technical Reports Server (NTRS)

    Hunt, James B.

    1990-01-01

    Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

  2. Spontaneous rupture of the plantar fascia.

    PubMed

    Ahstrom, J P

    1988-01-01

    In this study, rupture of the plantar fascia was seen in five feet, of which four had had plantar fasciitis. At the time of the injury, which is an acceleration type of motion, there is severe pain in the heel followed by the development of ecchymosis in the sole and toward the heel of the foot. With conservative symptomatic care, the acute symptoms as well as the plantar fasciitis symptoms subside, generally allowing full activity in 3 to 4 weeks.

  3. [Intradural rupture of an intervertebral disk].

    PubMed

    Paini, G P; Baldi, P G; Barra, N; Pasetti, S

    1978-01-01

    Since the first description of ruptured lumbar disc, erosion of a fragment of disc through the dura mater has been mentioned only rarely. The authros report two cases occurred among 1,078 herniated discs surgically treated in their department over a period of 8 years, from January 1st., 1970 through March 31st., 1978. Various factors that might contribute to this relatively rare complication of disc disease are mentioned, and literature on the subject is summarized.

  4. Incorporating Undrained Pore Fuid Pressurization Into Analyses of Off-Fault Plasticity During Dynamic Rupture

    NASA Astrophysics Data System (ADS)

    Viesca, R. C.; Templeton, E. L.; Rice, J. R.

    2007-12-01

    such pore pressure changes on the fault slip-weakening strength during rupture.

  5. Rupture Forces among Human Blood Platelets at different Degrees of Activation

    PubMed Central

    Nguyen, Thi-Huong; Palankar, Raghavendra; Bui, Van-Chien; Medvedev, Nikolay; Greinacher, Andreas; Delcea, Mihaela

    2016-01-01

    Little is known about mechanics underlying the interaction among platelets during activation and aggregation. Although the strength of a blood thrombus has likely major biological importance, no previous study has measured directly the adhesion forces of single platelet-platelet interaction at different activation states. Here, we filled this void first, by minimizing surface mediated platelet-activation and second, by generating a strong adhesion force between a single platelet and an AFM cantilever, preventing early platelet detachment. We applied our setup to measure rupture forces between two platelets using different platelet activation states, and blockade of platelet receptors. The rupture force was found to increase proportionally to the degree of platelet activation, but reduced with blockade of specific platelet receptors. Quantification of single platelet-platelet interaction provides major perspectives for testing and improving biocompatibility of new materials; quantifying the effect of drugs on platelet function; and assessing the mechanical characteristics of acquired/inherited platelet defects. PMID:27146004

  6. Traumatic Rupture of an Intermediate Tendon in a Patient with Patellar Duplication

    PubMed Central

    Hébert, Mathieu; LeBlanc, Pierre-Alexandre

    2017-01-01

    Patellar duplication is a rare asymptomatic condition. The diagnosis is often made following a traumatic event associated with an injury to the knee extensor mechanism. The treatment is often surgical and consists in removal of the smaller part of the patella with tendon reinsertion. The presence and rupture of an intermediate tendon between the two parts of the patella have not been reported in the modern literature. We present a traumatic rupture of an intermediate tendon in a patient with horizontal patellar duplication. The surgical management consisted of tenorrhaphy protected with a figure-of-eight tension band wire approximating the two parts of the patella. The patient recovered full knee range of motion and quadriceps strength at the last 8-month follow-up. PMID:28255488

  7. Myocardial Bridge and Acute Plaque Rupture

    PubMed Central

    Perl, Leor; Daniels, David; Schwartz, Jonathan; Tanaka, Shige; Yeung, Alan; Tremmel, Jennifer A.; Schnittger, Ingela

    2016-01-01

    A myocardial bridge (MB) is a common anatomic variant, most frequently located in the left anterior descending coronary artery, where a portion of the coronary artery is covered by myocardium. Importantly, MBs are known to result in a proximal atherosclerotic lesion. It has recently been postulated that these lesions predispose patients to acute coronary events, even in cases of otherwise low-risk patients. One such mechanism may involve acute plaque rupture. In this article, we report 2 cases of patients with MBs who presented with acute coronary syndromes despite having low cardiovascular risk. Their presentation was life-risking and both were treated urgently and studied with coronary angiographies and intravascular ultrasound. This latter modality confirmed a rupture of an atherosclerotic plaque proximal to the MB as a likely cause of the acute events. These cases, of unexplained acute coronary syndrome in low-risk patients, raise the question of alternative processes leading to the event and the role MB play as an underlying cause of ruptured plaques. In some cases, an active investigation for this entity may be warranted, due to the prognostic implications of the different therapeutic modalities, should an MB be discovered. PMID:28251167

  8. Ruptured aneurysms of sinuses of Valsalva

    PubMed Central

    Jugdutt, B. I.; Fraser, R. S.; Rossall, R. E.; Lee, S. J. K.

    1974-01-01

    At least one additional cardiac lesion was present in 18 consecutive patients with ruptured aneurysms of the sinuses of Valsalva who were investigated between 1956 and 1973 at the University of Alberta Hospital. Clinical diagnosis was made in 78% (14/18) of the patients. Confirmation at cardiac catheterization, operation or autopsy was obtained in all but one. The main sites of rupture were the right ventricle (seven cases), right atrium (five) and left ventricle (five). Fifty percent (9/18) are alive and well following prompt operative repair, an average of 8.2 years later (range, six months to 15 years). Replacement of the aortic valve was associated with a high mortality (50% early, 13% late, total 63%) which could be explained by the higher operative risk in this group of very ill patients. Eight patients (44.4%) had had bacterial endocarditis prior to presentation and this may have played a significant role in the rupture of the sinus of Valsalva aneurysm. ImagesFIG. 4FIG. 5 PMID:4278257

  9. [Splenic artery rupture in pancreatic pseudocyst].

    PubMed

    Ungania, S; Panocchia, N

    2000-01-01

    Hemorrhage is one of the most threatening complication of pancreatic pseudocyst. It results from erosion of adjacent vessels. Splenic, gastroduodenal, pancreaticoduodenal and middle colic vessels are predominantly involved. Hemorrhage may present different feature: intra and/or extraperitoneal collection, gastrointestinal bleeding. The authors report the rupture of splenic artery into pseudocyst, with the formation of pulsating pseudoaneurysm, increasing progressively until the final rupture. For the diagnosis the authors utilized: ultrasounds (US) which showed the cyst but not its nature and content; the CT scan which disclosed haematic contents; finally the US Color Doppler which proved the dynamic feature of hemorrhage. This technique allows to identify the arterious or venous source of bleeding and the possible presence of arteriovenous fistula. Arteriography was not performed due to circumstances, although it would permit bleeding vessel embolization and the control of hemorrhage. This procedure is not ever achievable, and doesn't exclude the possibility of rebleeding. On surgery, since the intraoperative rupture of the pseudoaneurysm occurred with severe hypovolemic shock, only a timely posterior mesogastric mobilization and the medially displacement of spleen-body-tail pancreatic complex, allowed to clamp the mass and the hemostasis. When such lesion are approached, it is mandatory to be prepared to carry on this maneuver: the severity of bleeding cannot allow intracystic ligature of bleeding vessel.

  10. [Premature rupture of fetal membranes and chorioamnionitis].

    PubMed

    Haram, K; Daugaard, H O

    1994-05-10

    The article presents a survey of preterm rupture of the amniotic membranes at term (more than 1 hour prior to uterine contractions) and preterm (< 37 weeks). The diagnosis of rupture can be suspected from the history alone in 90% of the cases, and confirmed by inspection. In doubtful cases the pH in fluid from the posterior fornix of the vagina is determined and microscopy is performed. Amniotic fluid is alkaline. Microscopy of a dried specimen shows "ferning" when amniotic fluid is present (crystallization test). Staining with Nil blue will reveal orange foetal cells in fresh specimens, usually only late in pregnancy (after the 38 week). The crystallization test is useful, however, in all three trimesters. The cause of membrane rupture and of chorioamnionitis may be infection. Chorioamnionitis is a serious clinical condition, but can be subclinical and may occur with intact membranes. It can lead to preterm delivery. It is important that chorioamnionitis be diagnosed (maternal fever, tachycardia, uterine contractions, abdominal pain, foul smelling vaginal discharge and elevated C-reactive protein). The condition is treated with antibiotics and labour must be induced.

  11. Rupture models with dynamically determined breakdown displacement

    USGS Publications Warehouse

    Andrews, D.J.

    2004-01-01

    The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete numerical calculations. Consistent resolution throughout an evolving rupture is achieved by specifying friction as a function of elapsed time after peak stress is reached. Such a time-weakening model produces Dc and fracture energy proportional to the square root of distance rupture has propagated in the case of uniform stress drop. The second friction law is more physically motivated. Energy loss in a damage zone outside the slip zone has the effect of increasing Dc and limiting peak slip velocity (Andrews, 1976). This article demonstrates a converse effect, that artificially limiting slip velocity on a fault in an elastic medium has a toughening effect, increasing fracture energy and Dc proportionally to rupture propagation distance in the case of uniform stress drop. Both the time-weakening and the velocity-toughening models can be used in calculations with heterogeneous stress drop.

  12. Heating and Weakening of Major Faults During Seismic Rupture

    NASA Astrophysics Data System (ADS)

    Rice, J. R.

    2007-12-01

    The absence of significant heat flow from major fault zones, and scarcity of evidence for their seismic melting, means that during earthquake slip such zones could not retain shear strength comparable to the typically high static friction strength of rocks. One line of explanation is that they are actually statically weak, which could be because materials of exceptionally low friction (smectites, talc) accumulate along fault zones, or perhaps because pore pressure within the fault core is far closer to lithostatic than hydrostatic. Without dismissing either, the focus here is on how thermal processes during the rapid slips of seismic rupture can weaken a fault which is indeed statically strong. (The discussion also leaves aside another kind of non- thermal dynamic weakening, possible when there is dissimilarity in seismic properties across the fault, and/or in poroelastic properties and permeability within fringes of damaged material immediately adjoining the slip surface. Spatially nonuniform mode II slip like near a propagating rupture front may then induce a substantial reduction in the effective normal stress \\barσ.) The heating and weakening processes to be discussed divide roughly into two camps: (1) Those which are expected to be active from the start of seismic slip, and hence will be present in all earthquakes; and (2) Those that kick-in after threshold conditions of rise of temperature T or accumulation of slip are reached, and hence become a feature of larger, or at least deeper slipping, earthquakes. It has been argued that the two major players of (1) are as follows: (1.1) Flash heating and weakening of frictional contact asperities in rapid slip [Rice, 1999, 2006; Tullis and Goldsby, 2003; Goldsby and Hirth, 2006; Beeler et al., 2007; Yuan and Prakash, 2007]. That gives a strong velocity-weakening character to the friction coefficient, which is consistent with inducing self-healing rupture modes [Noda et al., 2006; Lu et al., 2007]. It is a process

  13. 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.

  14. Effects of Apparent Supersonic Ruptures for Strike-slip Rupture: Should We Consider it in the Seismic Hazard Analysis?

    NASA Astrophysics Data System (ADS)

    Barrows, M. B.; Shao, G.; Ji, C.

    2009-12-01

    Recent numerical studies indicated that the supersonic rupture could produce larger off-fault damage at distant sites than the sub-shear rupture, due to the famous "mach cone" effect (Dunham and Archuleta, 2005; Bhat et al, 2007). These results were obtained using the steady-state rupture simulations in a half-space earth. For more realistic layered or 3D earth models, we should also consider the effects of apparent supersonic rupture, i.e., the deep rupture is still in a speed slower than the local shear velocity, but faster than the near surface S or even the P wave velocity. The apparent super-shear rupture could excite the mach effect, but how large it is has not yet been quantitatively addressed. In this study, we explore this possibility by performing numerical simulations for pure strike-slip ruptures on a vertical fault inside various layered earth models.

  15. 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.

  16. Chromaticity and wake field effect on the transverse motion of longitudinal bunch slices in the Tevatron

    SciTech Connect

    Ranjbar, V.H.; Ivanov, P.; /Fermilab

    2007-11-01

    The Transverse turn-by-turn evolution of a bunch slice after an impulse kick is examined considering chromatic and impedance effects. It is found that by fitting the envelope of the beam slice motion to simulated data is consistent with a resistive wall wake field the strength of which can be determined by fitting.

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

    USGS Publications Warehouse

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

    2001-01-01

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

  18. A Prospective Study of Platelet-Rich Plasma as Biological Augmentation for Acute Achilles Tendon Rupture Repair

    PubMed Central

    Zou, Jian; Mo, Xiaolian; Li, Tanzhu; Xue, Jianfeng; Mei, Guohua; Li, Xiaolin

    2016-01-01

    Acute Achilles tendon rupture is one of the most common tendon injuries in adults. We hypothesized that Platelet-Rich Plasma (PRP) can be used as biological augmentation for surgical treatment of acute Achilles tendon rupture. Our study is a prospective randomized controlled trial. Patients with acute Achilles tendon rupture undergoing surgical repair were randomly assigned into either control group or PRP group. End-to-end modified Krackow suture was performed in both groups. In the PRP group, PRP was injected into the paratenon sheath and around the ruptured tissue after the tendon was repaired. Postoperatively we evaluated isokinetic muscle strength at 3, 6, 12, and 24 months. In addition, ankle ROM, calf circumference, Leppilahti score, and the SF-36 score were evaluated at 6, 12, and 24 months after operation. At 3 months, the PRP group had better isokinetic muscle. The PRP group also achieved higher SF-36 and Leppilahti scores at 6 and 12 months. At 24 months, the PRP group had an improved ankle range of motion compared to the control group. Our study results suggest that PRP can serve as a biological augmentation to acute Achilles tendon rupture repair and improves both short and midterm functional outcomes. PMID:28116306

  19. 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'.

  20. 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/α). 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/α ± 0.14 vr/α. 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

  1. Analysis of factors responsible for the accelerated creep rupture of 12% Cr martensitic steel weld joints

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, A. S.; Okhapkin, K. A.; Mikhailov, M. S.; Skutin, V. S.; Zubova, G. E.; Fedotov, B. V.

    2016-06-01

    In the process of the investigation of the heat resistance of a 0.07C-12Cr-Ni-Mo-V-Nb steel of the martensitic-ferritic class, a reduction was revealed in the long-term strength of its welded joints to below the level of the strength of the base metal. To establish the causes for the accelerated failure of the welded joints, an imitation of the thermal cycles was carried out that produce the structure of the heataffected zone using a dilatometer. In the samples with the structure that corresponds to that of the heataffected zone, a local zone of softening was revealed. The investigations of the metal structure using transmission electron microscopy have shown that the reduction in the creep rupture strength was caused by structural changes under the conditions of the thermal cycle of welding upon the staying of the steel in the temperature range between the Ac 1 and Ac 3 points.

  2. [Evaluation of surgical repair of distal biceps tendon ruptures].

    PubMed

    Behounek, J; Hrubina, M; Skoták, M; Krumpl, O; Zahálka, M; Dvorák, J; Fucík, M

    2009-02-01

    PURPOSE OF THE STUDY To present the results of surgical repair of ruptures of the distal tendon of the biceps brachii muscle and thus show the adequacy of this treatment. MATERIAL Between 1987 and 2006, 19 patients had surgery for distal biceps tendon rupture. Only one side was affected in each patient. All patients were men between 28 and 69 years (average age, 47.5 years) at the time of injury (surgery). When the patients were evaluated at the end of 2007, 18 patients were included, because one died a year after surgery. METHODS The surgical repair always included a single-incision anatomical reattachment into the radial tuberosity. In 11 patients, a modified Mac Reynolds method with screw and washer fixation was used; in seven patients the insertion was fixed with Mitek anchors and, in one, it was sutured to the adjacent soft tissues. The average follow-up was 7 years (range, 1 to 20.5 years). The patients were evaluated for the cause of injury, their physical activity, age, dominance of the injured arm, surgical procedure and complications. RESULTS In 18 patients surgical repair was done early and, in one, at 16 days after injury. In all of them the tendon was detached from its site of insertion, but never torn. The intra-operative complications included, in one patient, bleeding owing to iatrogenic damage to a branch of the brachial artery, and difficult separation of the tendon due to its previous healed injury in another patient. Early post-operative complications included superficial skin necrosis in one patient and transient neurological deficit of the dorsal brand of the radial nerve and of the lateral cutaneous nerve of the forearm in two and one patient, respectively. The late complications were heterotropic ossification in three patients and screw migration in the one treated by the Mac Reynolds method. Excellent results were recorded in 11 patients (61 %), and good outcomes with a slight restriction of motion or muscle strength not limiting the

  3. Laparoscopic correction of right transverse colostomy prolapse.

    PubMed

    Gundogdu, Gokhan; Topuz, Ufuk; Umutoglu, Tarik

    2013-08-01

    Colostomy prolapse is a frequently seen complication of transverse colostomy. In one child with recurrent stoma prolapse, we performed a loop-to-loop fixation and peritoneal tethering laparoscopically. No prolapse had recurred at follow-up. Laparoscopic repair of transverse colostomy prolapse seems to be a less invasive method than other techniques.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Transverse Mercator Projection Via Elliptic Integrals

    NASA Technical Reports Server (NTRS)

    Wallis, David E.

    1992-01-01

    Improved method of construction of U.S. Army's universal transverse Mercator grid system based on Gauss-Kruger transverse Mercator projection and on use of elliptic integrals of second kind. Method can be used to map entire northern or southern hemisphere with respect to single principal meridian.

  9. 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

  10. Noninvasive vascular displacement estimation for relative elastic modulus reconstruction in transversal imaging planes.

    PubMed

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

    2013-03-11

    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.

  11. Electrodeposited, Transverse Nanowire Electroluminescent Junctions.

    PubMed

    Qiao, Shaopeng; Xu, Qiang; Dutta, Rajen K; Le Thai, Mya; Li, Xiaowei; Penner, Reginald M

    2016-09-27

    The preparation by electrodeposition of transverse nanowire electroluminescent junctions (tn-ELJs) is described, and the electroluminescence (EL) properties of these devices are characterized. The lithographically patterned nanowire electrodeposition process is first used to prepare long (millimeters), linear, nanocrystalline CdSe nanowires on glass. The thickness of these nanowires along the emission axis is 60 nm, and the width, wCdSe, along the electrical axis is adjustable from 100 to 450 nm. Ten pairs of nickel-gold electrical contacts are then positioned along the axis of this nanowire using lithographically directed electrodeposition. The resulting linear array of nickel-CdSe-gold junctions produces EL with an external quantum efficiency, EQE, and threshold voltage, Vth, that depend sensitively on wCdSe. EQE increases with increasing electric field and also with increasing wCdSe, and Vth also increases with wCdSe and, therefore, the electrical resistance of the tn-ELJs. Vth down to 1.8(±0.2) V (for wCdSe ≈ 100 nm) and EQE of 5.5(±0.5) × 10(-5) (for wCdSe ≈ 450 nm) are obtained. tn-ELJs produce a broad EL emission envelope, spanning the wavelength range from 600 to 960 nm.

  12. Transversity from two pion interference fragmentation

    SciTech Connect

    She Jun; Huang Yang; Barone, Vincenzo; Ma Boqiang

    2008-01-01

    We present calculation on the azimuthal spin asymmetries for pion pair production in semi-inclusive deep inelastic scattering (SIDIS) process at both HERMES and COMPASS kinematics, with transversely polarized proton, deuteron, and neutron targets. We calculate the asymmetry by adopting a set of parametrization of the interference fragmentation functions and two different models for the transversity. We find that the result for the proton target is insensitive to the approaches of the transversity but more helpful to understand the interference fragmentation functions. However, for the neutron target, which can be obtained through using deuteron and {sup 3}He targets, we find different predictions for different approaches to the transversity. Thus probing the two pion interference fragmentation from the neutron can provide us more interesting information on the transversity.

  13. Multi-Scale Effects in the Strength of Ceramics

    PubMed Central

    Cook, Robert F.

    2016-01-01

    Multiple length-scale effects are demonstrated in indentation-strength measurements of a range of ceramic materials under inert and reactive conditions. Meso-scale effects associated with flaw disruption by lateral cracking at large indentation loads are shown to increase strengths above the ideal indentation response. Micro-scale effects associated with toughening by microstructural restraints at small indentation loads are shown to decrease strengths below the ideal response. A combined meso-micro-scale analysis is developed that describes ceramic inert strength behaviors over the complete indentation flaw size range. Nano-scale effects associated with chemical equilibria and crack velocity thresholds are shown to lead to invariant minimum strengths at slow applied stressing rates under reactive conditions. A combined meso-micro-nano-scale analysis is developed that describes the full range of reactive and inert strength behaviors as a function of indentation load and applied stressing rate. Applications of the multi-scale analysis are demonstrated for materials design, materials selection, toughness determination, crack velocity determination, bond-rupture parameter determination, and prediction of reactive strengths. The measurements and analysis provide strong support for the existence of sharp crack tips in ceramics such that the nano-scale mechanisms of discrete bond rupture are separate from the larger scale crack driving force mechanics characterized by continuum-based stress-intensity factors. PMID:27563150

  14. Measuring thermal rupture force distributions from an ensemble of trajectories.

    PubMed

    Swan, J W; Shindel, M M; Furst, E M

    2012-11-09

    Rupture, bond breaking, or extraction from a deep and narrow potential well requires considerable force while producing minimal displacement. In thermally fluctuating systems, there is not a single force required to achieve rupture, but a spectrum, as thermal forces can both augment and inhibit the bond breaking. We demonstrate measurement and interpretation of the distribution of rupture forces between pairs of colloidal particles bonded via the van der Waals attraction. The otherwise irreversible bond is broken by pulling the particles apart with optical tweezers. We show that an ensemble of the particle trajectories before, during and after the rupture event may be used to produce a high fidelity description of the distribution of rupture forces. This analysis is equally suitable for describing rupture forces in molecular and biomolecular contexts with a number of measurement techniques.

  15. 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.

  16. Treatment of Ruptured Vertebral Artery Dissecting Aneurysms

    PubMed Central

    Hamasaki, Osamu; Ikawa, Fusao; Hidaka, Toshikazu; Kurokawa, Yasuharu; Yonezawa, Ushio

    2014-01-01

    Summary We evaluated the outcomes of endovascular or surgical treatment of ruptured vertebral artery dissecting aneurysms (VADAs), and investigated the relations between treatment complications and the development and location of the posterior inferior cerebellar artery (PICA). We treated 14 patients (12 men, two women; mean age, 56.2 years) with ruptured VADAs between March 1999 and June 2012 at our hospital. Six and eight patients had Hunt and Hess grades 1-3 and 4-5, respectively. Twelve patients underwent internal endovascular trapping, one underwent proximal endovascular occlusion alone, and one underwent proximal endovascular occlusion in the acute stage and occipital artery (OA)-PICA anastomosis and surgical trapping in the chronic stage. The types of VADA based on their location relative to the ipsilateral PICA were distal, PICA-involved, and non-PICA in nine, two, and three patients, respectively. The types of PICA based on their development and location were bilateral anterior inferior cerebellar artery (AICA)-PICA, ipsilateral AICA-PICA, extradural, and intradural type in one, two, two, and nine patients, respectively. Two patients with high anatomical risk developed medullary infarction, but their midterm outcomes were better than in previous reports. The modified Rankin scale indicated grades 0-2, 3-5, and 6 in eight, three, and three patients, respectively. A good outcome is often obtained in the treatment of ruptured VADA using internal endovascular trapping, except in the PICA-involved type, even with high-grade subarachnoid hemorrhage. Treatment of the PICA-involved type is controversial. The anatomical location and development of PICA may be predicted by complications with postoperative medullary infarction. PMID:24976093

  17. Surgical repair of a rupture of the pectoralis major muscle

    PubMed Central

    Pochini, Alberto De Castro; Andreoli, Carlos Vicente; Ejnisman, Benno; Maffulli, Nicola

    2015-01-01

    Muscle rupture is rarely treated surgically. Few reports of good outcomes after muscular suture have been published. Usually, muscular lesions or partial ruptures heal with few side effects or result in total recovery. We report a case of an athlete who was treated surgically to repair a total muscular rupture in the pectoralis major muscle. After 6 months, the athlete returned to competitive practice. After a 2-year follow-up, the athlete still competes in skateboard championships. PMID:25716033

  18. Source Rupture Process of the 2005 Tarapaca Intermediate Depth Earthquake

    NASA Astrophysics Data System (ADS)

    Peyrat, S.; Favreau, P.; de Chabalier, J.; Bouin, M.

    2007-12-01

    We investigate the details of the rupture process of the large (Mw 7.7) intermediate-depth earthquake that occurred on 13 June 2005 in the Tarapaca region of the Northern Chile seismic gap, using different data sets and different methods. The high quality and variety of seismic and geodetic data available for this event provided an unprecedented opportunity to study its source in detail. This earthquake is a slab-pull event with down dip extensional source mechanism. The aftershock distribution, determined from a post-seismic temporary array, indicates a sub-horizontal fault plane lying between the upper and lower planes of the double seismic zone. This earthquake was also recorded by a permanent digital strong-motion network operated by the University of Chile. These records have absolute time and high dynamic range so that they contain direct information about the rupture process. We used a systematic, fully nonlinear inversion method based on the neighbourhood algorithm to invert for the kinematic slip distribution using the accelerometric data set. This low frequency inversion provides a relatively smooth image of the rupture history. The kinematic inversion shows that the earthquake occurred by the rupture of two asperities. Based on the kinematic inversion result, we propose dynamic rupture models in order to quantify the dynamic rupture process. We simulate the dynamic rupture process and the strong ground motion using a 3D finite-difference method. In our simulation, dynamic rupture grows under the simultaneous control of initial stress and rupture resistance by friction. We constrain dynamic rupture parameters of the Tarapaca earthquake by simple trial and error. Large intraplate earthquakes in subduction zone are quite common although very few have been studied in detail. These earthquakes occurred at depth where the mechanism by which they are triggered remains poorly understood. Consequently, the determination of source rupture for intermediate

  19. Alliance ruptures, impasses, and enactments: a relational perspective.

    PubMed

    Safran, Jeremy D; Kraus, Jessica

    2014-09-01

    Alliance ruptures, impasses, and transference-countertransference enactments are inevitable in therapy. A growing body of evidence suggests that repairing ruptures in the alliance is related to positive outcome (Safran, Muran, & Eubanks-Carter, 2011). Our research program has led to the development of training methods to enhance therapists' abilities to detect and work constructively with alliance ruptures and negative therapeutic process (Safran et al., 2014). This article outlines relevant theoretical underpinnings, intervention principles, and empirical findings.

  20. Spontaneous rupture of the urinary bladder in the puerperium.

    PubMed

    Kekre, A N; Kekre, N; Nath, V; Seshadri, L

    1997-11-01

    Spontaneous rupture of the urinary bladder in the puerperium is extremely rare. The patient usually presents with acute abdominal pain. Awareness on the part of the treating surgeon that bladder rupture is a possibility will lead to an early diagnosis. Immediate exploration, removing urine from the peritoneal cavity or retropubic space, closing the rupture and securing good vesical drainage, results in resumption of vesical function, and thereby decreases the mortality and morbidity.

  1. 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

  2. Seismic rupture propagation beneath potential landslide wedge

    NASA Astrophysics Data System (ADS)

    Sakaguchi, A.; Kawamura, K.

    2011-12-01

    During 2011 Tohoku earthquake (Mw 9.0), much larger slip and tsunami occurred than expectation at outer-wedge (toe of the trench landward slope) of Japan trench (eg. Ide et al., 2011). Similarly, outer-wedge deformation was pointed out in northern segment of 1986 Meiji-Sanriku earthquake (Ms 7.2), and it was discussed that earthquake-related landslide induced large tsunami (eg. Kanamori, 1972; Tanioka and Satake, 1996). Many landslides and normal faults, potential tsunami genesis, are developed at outer-wedge of Japan trench (Henry et al., 1989). Some steep normal-faults turn to horizon at deep portion, and land sliding may be prevented by basal friction. If seismic rupture propagates to basal fault of the outer-wedge, triggered gravity collapse will enlarge deformation of the outer-wedge to cause large tsunamis. It was considered that seismogenic fault locks at deep portion under inner-wedge of the plate subduction zone, and outer-wedge was classified into aseismic zone classically. Seismic rupture propagation to outer-wedge is still uncertain. Seismic slip at the outer-wedge was found from the drilled core during IODP Nankai trough seismogenic zone drilling project (NanTroSEIZE) in Nankai trough, southwest Japan. Samples were obtained from the frontal thrust (438 mbsf), which connects the deep plate boundary to the seafloor at the toe of the accretionary wedge, and from a megasplay fault (271 mbsf) that branches from the plate boundary décollement. Higher vitrinite reflectance of 0.57 % and 0.37 % than the host rock of 0.24 % were found at splay and plate boundary faults zones respectively. These correspond with 300-400 °C and > 20°C of host rock. Local high temperature zone less than several cm thick may be caused by frictional shear heat at fault zone (Sakaguchi, et al., 2011). Shear velocity and durations can be estimated from thermal property of the sediment and distribution of the vitrinite anomaly (Hamada et al., 2011). This result shows that seismic

  3. 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

  4. Directed assembly and rupture mechanics of colloidal aggregates.

    PubMed

    Pantina, John P; Furst, Eric M

    2004-05-11

    The macroscopic rheological behavior of colloidal gels arises from the micromechanical properties of the gel backbone, which are governed by nanoscale particle interactions. These colloidal interactions have been commonly understood in terms of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Recent work has shown, however, that nonidealities, such as surface roughness and charge nonuniformity, may cause the particle interactions to significantly deviate from DLVO predictions at near-contact separations. Here we present novel techniques for directing the assembly of colloidal aggregates that mimic the gel backbone, based on optical micromanipulation of multiple particles using laser tweezers. This also provides an in situ method for measuring near-contact interactions via single-bond rupture forces. We find that PMMA particles aggregated in the presence of nonorganic salts exhibit interparticle bond strengths more than 10 times greater than those predicted by DLVO theory. However, good agreement is found with DLVO predictions when the anionic surfactant sodium dodecyl sulfate (SDS) is used as the flocculant.

  5. Effects of Along-strike Fault Heterogeneity on Rupture Propagation

    NASA Astrophysics Data System (ADS)

    Weng, H.; Yang, H.

    2015-12-01

    Fault zone materials have been suggested to be heterogeneous, such as along-strike variations of low velocity zone and stress conditions. How these fault heterogeneities affect earthquake rupture propagation is important to advance our understanding of earthquake physics, and yet remains poorly understood. Here we investigate the effects of along-strike fault heterogeneity on rupture propagation through numerical modeling on a strike-slip planar fault governed by a linear slip-weakening friction law. We first implement along-strike variations of fault zone materials based on field observations, which have shown the velocities of P and S waves of the low velocity zones can be reduced up to 50% compared to intact rocks. The rupture speed is decreased if the rupture propagates into materials with lower shear modulus and keeps at a stable speed quickly. In contrast, the rupture speed is increased if the rupture propagates into materials with higher shear modulus and accelerates into a steady speed more slowly. If this material boundary is very close to the nucleation zone, it may inhibit the nucleation process. In addition, there is always a perturbation on the rupture speed near the boundary due to the reflected energy. We then investigate the effects of a patch with elevated effective normal stress (barrier) on rupture propagation. Except for the distance d between the barrier and the nucleation zone, its width w, and the additional effective normal stress Δσn, all other parameters are kept constant for all the simulated models. Our results confirm that the barrier may slow down or stop coseismic ruptures, but may also induce supershear ruptures. Moreover, there is a sharp boundary between stopping the rupture and making very strong supershear ruptures. Furthermore, we demonstrate that the supershear rupture may emerge in a region that is delineated by two approximate linear boundaries for parameters d and w. The duration of supershear ruptures increases as the

  6. Application of Strength Diagnosis.

    ERIC Educational Resources Information Center

    Newton, Robert U.; Dugan, Eric

    2002-01-01

    Discusses the various strength qualities (maximum strength, high- and low-load speed strength, reactive strength, rate of force development, and skill performance), noting why a training program design based on strength diagnosis can lead to greater efficacy and better performance gains for the athlete. Examples of tests used to assess strength…

  7. 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.

  8. Insights into pulverized rock formation from dynamic rupture models of earthquakes

    NASA Astrophysics Data System (ADS)

    Payne, R. M.; Duan, B.

    2017-02-01

    Pulverized rocks (PR) are extremely incohesive and highly fractured rocks found within the damage zones of several large strike-slip faults around the world. They maintain their crystal structure, show little evidence of shearing or chemical alteration, and are believed to be produced by strong tensile forces. Several mechanisms for pulverization have been proposed based on simple qualitative analyses or laboratory experiments under simplified loading conditions. Numerical modelling, however, can offer new insights into what is needed to produce PR and likely conditions of formation. We perform dynamic rupture simulations of different earthquakes, varying the magnitude, the slip distribution, and the rupture speed (supershear and subshear), while measuring the stresses produced away from the fault. To contextualize our results, a basic threshold of 10 MPa is set as the tensile strength of the rock mass and recordings are made of where, when, and by how much this threshold is exceeded for each earthquake type. Guided by field observations, we discern that a large (>Mw 7.1) subshear earthquake along a bimaterial fault produces a pulverized rock distribution most consistent with observations. The damage is asymmetric with the majority on the stiffer side of the fault extending out for several hundred metres. Within this zone there is a large and sudden volumetric expansion in all directions as the rupture passes. We propose that such an extreme tensile stress state, repeated for every earthquake, eventually produces the PR seen in the field.

  9. [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.

  10. Shear rupture of a directionally solidified eutectic gamma/gamma prime - alpha (Mo) alloy

    NASA Technical Reports Server (NTRS)

    Harf, F. H.

    1978-01-01

    Directionally solidified Mo alloys are evaluated to determine the shear rupture strength and to possibly improve it by microstructural and heat treatment variations. Bars of the 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 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 is shown that shear rupture failures are partly transgranular and that resistance to failure is prompted 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. A simulated coating heat treatment appeared to increase the transformation of gamma to gamma prime and raised the average shear life of aligned specimens to 111 hours. However, heat treatments at 1245 C and especially at 1190 C appeared to be detrimental by causing partial solutioning of the gamma prime, and reducing lives to 47 and 10 hours, respectively.

  11. Insights into Pulverized Rock Formation from Dynamic Rupture Models of Earthquakes

    NASA Astrophysics Data System (ADS)

    Payne, R. M.; Duan, B.

    2016-11-01

    Pulverized rocks (PR) are extremely incohesive and highly fractured rocks found within the damage zones of several large strike-slip faults around the world. They maintain their crystal structure, show little evidence of shearing or chemical alteration, and are believed to be produced by strong tensile forces. Several mechanisms for pulverization have been proposed based on simple qualitative analyses or laboratory experiments under simplified loading conditions. Numerical modeling, however, can offer new insights into what is needed to produce PR and likely conditions of formation. We perform dynamic rupture simulations of different earthquakes, varying the magnitude, the slip distribution, and the rupture speed (supershear and subshear), while measuring the stresses produced away from the fault. To contextualize our results, a basic threshold of 10 MPa is set as the tensile strength of the rock mass and recordings are made of where, when, and by how much this threshold is exceeded for each earthquake type. Guided by field observations, we discern that a large (> Mw 7.1) subshear earthquake along a bimaterial fault produces a pulverized rock distribution most consistent with observations. The damage is asymmetric with the majority on the stiffer side of the fault extending out for several hundred meters. Within this zone there is a large and sudden volumetric expansion in all directions as the rupture passes. We propose that such an extreme tensile stress state, repeated for every earthquake, eventually produces the PR seen in the field.

  12. 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.

  13. 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

  14. TRANSVERSE SPIN AT PHENIX AND FUTURE PLANS.

    SciTech Connect

    MAKDISI,Y.

    2005-01-28

    The PHENIX experiment took data with transversely polarized proton beams in 2001-2002 and measured the transverse single spin asymmetries in inclusive neutral pion and non-identified charge hadrons at midrapidity and {radical} s = 200 GeV. The data near X{sub F} {approx} 0 cover a transverse momentum range from 0.5 to 5.0 GeV/c. The observed asymmetries are consistent with zero with good statistical accuracy. This paper presents the current work in light of earlier measurements at lower energies in this kinematic region and the future plans of the PHENIX detector.

  15. Transverse single bunch instability study on BEPC

    NASA Astrophysics Data System (ADS)

    Gao, J.; Sun, Y. P.

    2007-04-01

    In recent years, a lot of experiments were done on ESRF and ELETTRA to study the single bunch transverse instability. To prevent such instabilities on BEPCII in the future, experiments were made on the single bunch transverse instability threshold current versus the chromaticity on BEPC. By analyzing the experimental data based on the theory developed in [J. Gao, Nucl. Instr. and Meth. A 416 (1998) 186 (see also PAC97, Vancouver, Canada, 1997, p. 1605).], the transverse loss factor of BEPC and the corresponding scaling law are obtained.

  16. Transverse Colon Diverticulitis with Calcified Fecalith

    PubMed Central

    Solak, Aynur; Solak, Ilhami; Genç, Berhan; Sahin, Neslin; Yalaz, Seyhan

    2013-01-01

    Left colonic diverticula are common in Western populations, whereas right colonic diverticulosis primarily occurs in Oriental populations. Diverticulitis of the transverse colon is very rare, with very few cases reported in the literature. Herein, we report a case of transverse colon diverticulitis caused by a calcified stone in a 69-year-old female. This was a solitary diverticulum. The signs and symptoms of the disease are similar to acute pancreatitis. To the best of our knowledge, this is the first report describing the MRI findings of a patient with trans-verse colon diverticulitis caused by a calcified stone. PMID:25610254

  17. 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.

  18. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement

    PubMed Central

    Sung, June-Min; Chung, In-Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun-Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo

    2017-01-01

    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture. PMID:27873520

  19. Rupture of Right Ventricular Free Wall Following Ventricular Septal Rupture in Takotsubo Cardiomyopathy with Right Ventricular Involvement.

    PubMed

    Sung, June Min; Hong, Sung Jin; Chung, In Hyun; Lee, Hye Young; Lee, Jae Hoon; Kim, Hyun Jung; Byun, Young Sup; Kim, Byung Ok; Rhee, Kun Joo

    2017-01-01

    Most patients diagnosed with takotsubo cardiomyopathies are expected to almost completely recover, and their prognosis is excellent. However, complications can occur in the acute phase. We present a case of a woman with takotsubo cardiomyopathy with right ventricular involvement who developed a rupture of the right ventricular free wall following ventricular septal rupture, as a consequence of an acute increase in right ventricular afterload by left-to-right shunt. Our case report illustrates that takotsubo cardiomyopathy can be life threatening in the acute phase. Ventricular septal rupture in biventricular takotsubo cardiomyopathy may be a harbinger of cardiac tamponade by right ventricular rupture.

  20. 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.

  1. Novel itinerant transverse spin waves

    NASA Astrophysics Data System (ADS)

    Feldmann, John Delaney

    In 1956, Lev Davidovich Landau put forth his theory on systems of interacting fermions, or fermi liquids. A year later, Viktor Pavlovich Silin described spin waves that such a system of fermions would support. The treatment of the contribution of the molecular field to the spin wave dispersion was a novel aspect of these spin waves. Silin predicted that there would exist a hierarchy of spin waves in a fermi liquid, one for each component of the spherical harmonic expansion of the fermi surface. In 1968, Anthony J. Leggett and Michael J. Rice derived from fermi liquid theory how the behavior of the spin diffusion coefficient of a fermi liquid could be directly experimentally observable via the spin echo effect [24]. Their prediction, that the diffusion coefficient of a fermi liquid would not decay exponentially with temperature, but rather would have a maximum at some non-zero temperature, was a direct consequence of the fermi liquid molecular field and spin wave phenomena, and this was corroborated by experiment in 1971 by Corruccini, et al. [13]. A parallel advancement in the theory of fermi liquid spin waves came with the extension of the theory to describe weak ferromagnetic metals. In 1959, Alexei Abrikosov and I. E. Dzyaloshiski put forth a theoretical description of a ferromagnetic fermi liquid [1]. In 2001, Kevin Bedell and Krastan Blagoev showed that a non-trivial contribution to the dispersion of the ferromagnetic current spin wave arises from the necessary consideration of higher harmonic moments in the distortion of the fermi surface from its ground state [8]. In the chapters to follow, the author presents new results for transverse spin waves in a fermi liquid, which arise from a novel ground state of a fermi liquid-one in which an l = 1 harmonic distortion exists in the ground state polarization. It is shown that such an instability can lead to spin waves with dispersions that are characterized by a linear dependence on the wave number at long

  2. Parametrization of the Transverse Momentum Dependent Light-Front Correlator for Gluons

    NASA Astrophysics Data System (ADS)

    Cotogno, Sabrina

    2017-03-01

    We study the transverse momentum dependent light-front correlator for gluons. At the operator level this is expressed as a matrix element containing nonlocal field strength operators and gauge links bridging the nonlocality. We parametrize the leading (twist-2) gluon-gluon correlator in terms of transverse momentum dependent distribution functions for unpolarized, vector and tensor polarized targets (the latter being relevant for spin-1 targets). For a tensor polarized target there are eleven functions among which two are time reversal odd. We discuss bounds on some functions which might become useful for future applications.

  3. Transverse impedances of cavities and collimators

    SciTech Connect

    Kheifets, S.A.; Bane, K.L.F.; Bizek, H.

    1987-03-01

    Field matching has been used to compute the transverse impedance of simple, cylindrically symmetric, perfectly conducting structures, the subregions of which are separated by radial cuts. The method is briefly described, and some early results are presented. (LEW)

  4. Transversally periodic solitary gravity–capillary waves

    PubMed Central

    Milewski, Paul A.; Wang, Zhan

    2014-01-01

    When both gravity and surface tension effects are present, surface solitary water waves are known to exist in both two- and three-dimensional infinitely deep fluids. We describe here solutions bridging these two cases: travelling waves which are localized in the propagation direction and periodic in the transverse direction. These transversally periodic gravity–capillary solitary waves are found to be of either elevation or depression type, tend to plane waves below a critical transverse period and tend to solitary lumps as the transverse period tends to infinity. The waves are found numerically in a Hamiltonian system for water waves simplified by a cubic truncation of the Dirichlet-to-Neumann operator. This approximation has been proved to be very accurate for both two- and three-dimensional computations of fully localized gravity–capillary solitary waves. The stability properties of these waves are then investigated via the time evolution of perturbed wave profiles. PMID:24399922

  5. Transverse optical forces for manipulating nanoparticles

    NASA Astrophysics Data System (ADS)

    Zharov, Alexander A.; Zharov, Alexander A.; Shadrivov, Ilya V.; Zharova, Nina A.

    2016-12-01

    We study optical forces acting on a subwavelength particle with anisotropic polarizability and discover an optomechanical effect that resembles the Hall effect for electrons. While in the classical Hall effect the transverse Lorentz force and the transverse voltage appear due to the static magnetic field which induces the nondiagonal components of the electric conductivity tensor; in our case the imaginary parts of the nondiagonal elements of the polarizability tensor are responsible for the transverse scattering force. We calculate this force for the examples of the ellipsoidal plasmonic nanoparticles and the spherical particle with gyromagnetic properties, and show that the transverse force depends on the physical origin of the anisotropy of the polarizability, and on the electromagnetic wave structure around the particle. Moreover, this force primarily occurs in the inhomogeneous field only.

  6. Development of Transverse Modes Damped DLA Structure

    SciTech Connect

    Jing, C.; Kanareykin, A.; Schoessow, P.; Gai, W.; Konecny, R.; Power, J. G.; Conde, M.

    2009-01-22

    As the dimensions of accelerating structures become smaller and beam intensities higher, the transverse wakefields driven by the beam become quite large with even a slight misalignment of the beam from the geometric axis. These deflection modes can cause inter-bunch beam breakup and intra-bunch head-tail instabilities along the beam path, and thus BBU control becomes a critical issue. All new metal based accelerating structures, like the accelerating structures developed at SLAC or power extractors at CLIC, have designs in which the transverse modes are heavily damped. Similarly, minimizing the transverse wakefield modes (here the HEMmn hybrid modes in Dielectric-Loaded Accelerating (DLA) structures) is also very critical for developing dielectric based high energy accelerators. In this paper, we present the design of a 7.8 GHz transverse mode damped DLA structure currently under construction, along with plans for the experimental program.

  7. Exploring the transverse spin structure of the nucleon

    SciTech Connect

    D'Alesio, Umberto

    2008-10-13

    We discuss our present understanding of the transverse spin structure of the nucleon and of related properties originating from parton transverse motion. Starting from the transversity distribution and the ways to access it, we then address the role played by spin and transverse momentum dependent (TMD) distributions in azimuthal and transverse single spin asymmetries. The latest extractions of the Sivers, Collins and transversity functions are also presented.

  8. Schwarzschild solution from Weyl transverse gravity

    NASA Astrophysics Data System (ADS)

    Oda, Ichiro

    2017-01-01

    We study classical solutions in the Weyl-transverse (WTDiff) gravity. The WTDiff gravity is invariant under both the local Weyl (conformal) transformation and the volume preserving diffeomorphisms (Diff) (transverse diffeomorphisms (TDiff)) and is known to be equivalent to general relativity at least at the classical level. In particular, we find that in a general spacetime dimension, the Schwarzschild metric is a classical solution in the WTDiff gravity when it is expressed in the Cartesian coordinate system.

  9. Transverse flat plate heat pipe experiment

    NASA Technical Reports Server (NTRS)

    Edelstein, F.

    1978-01-01

    This paper describes a Shuttle-launched flight experiment to evaluate the performance of a transverse flat plate heat pipe that serves as an integral temperature control/mounting panel for electronic equipment. A transverse heat pipe is a gas-controlled variable conductance heat pipe that can handle relatively large thermal loads. An experiment designed to flight test the concept over a 6-9 month period is self-sufficient with respect to electrical power, timing sequences, and data storage.

  10. Acute transverse myelitis complicating breakthrough varicella infection.

    PubMed

    Aslan, Asli; Kurugol, Zafer; Gokben, Sarenur

    2014-11-01

    We report a 10-year-old girl who presented with acute transverse myelitis after breakthrough varicella infection. The diagnosis was based on the development of motor weakness, paraparesis and bladder dysfunction, spinal magnetic resonance imaging findings and detection of anti-varicella zoster virus IgG antibody in the cerebrospinal fluid. This case report highlights that breakthrough varicella can result in serious complications such as acute transverse myelitis.

  11. Chiral dynamics and peripheral transverse densities

    SciTech Connect

    Granados, Carlos G.; Weiss, Christian

    2014-01-01

    In the partonic (or light-front) description of relativistic systems the electromagnetic form factors are expressed in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as the peripheral densities at transverse distances b = O(M{sub {pi}}{sup -1}) and compute them in a parametrically controlled manner. A dispersion relation connects the large-distance behavior of the transverse charge and magnetization densities to the spectral functions of the Dirac and Pauli form factors near the two--pion threshold at timelike t = 4 M{ sub {pi}}{sup 2}, which can be computed in relativistic chiral effective field theory. Using the leading-order approximation we (a) derive the asymptotic behavior (Yukawa tail) of the isovector transverse densities in the "chiral" region b = O(M{sub {pi}}{sup -1}) and the "molecular" region b = O(M{sub N}{sup 2}/M{sub {pi}}{sup 3}); (b) perform the heavy-baryon expansion of the transverse densities; (c) explain the relative magnitude of the peripheral charge and magnetization densities in a simple mechanical picture; (d) include Delta isobar intermediate states and study the peripheral transverse densities in the large-N{ sub c} limit of QCD; (e) quantify the region of transverse distances where the chiral components of the densities are numerically dominant; (f) calculate the chiral divergences of the b{sup 2}-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit M{sub {pi}} -> 0 and determine their spatial support. Our approach provides a concise formulation of the spatial structure of the nucleon's chiral component and offers new insights into basic properties of the chiral expansion. It relates the information extracted from low-t elastic form factors to the generalized parton distributions probed in peripheral high-energy scattering processes.

  12. Spontaneous gastroduodenal artery aneurysm rupture in acute surgery.

    PubMed

    Savage, Jessica; Hsee, Li

    2012-06-29

    Among the rarest of the visceral aneurysms, gastroduodenal artery (GDA) aneurysms often present with spontaneous rupture and are associated with a high mortality rate. Their aetiology is poorly understood. This report describes a case of haemorrhagic shock due to sudden GDA aneurysm rupture in a patient with a significant autoimmune history.

  13. Delayed rupture of renal artery after renal percutaneous transluminal angioplasty

    SciTech Connect

    Puijlaert, C.B.A.J.; Mali, W.P.; Rosenbusch, G.; van Straalen, A.M.; Klinge, J.; Feldberg, M.A.M.

    1986-06-01

    Two cases are reported in which rupture of the renal artery occurred many hours after renal percutaneous transluminal angioplasty. Delayed rupture can be recognized by the angiographic appearance and by the presence of persistent flank pain. The typical angiographic finding is a poorly defined zone of contrast medium at the site of perforation.

  14. The Resolution of Ruptures in the Therapeutic Alliance.

    ERIC Educational Resources Information Center

    Safran, Jeremy D.; Muran, J. Christopher

    1996-01-01

    A rupture in the therapeutic alliance is a deterioration in the quality of the relationship between patient and therapist; it is an interpersonal marker that indicates an opportunity for exploring and understanding the processes that maintain a maladaptive interpersonal schema. Outlines features of a research program on ruptures in the therapeutic…

  15. Comparing two methods of identifying alliance rupture events.

    PubMed

    Coutinho, Joana; Ribeiro, Eugénia; Sousa, Inês; Safran, Jeremy D

    2014-09-01

    This study compared two methods of detecting ruptures in therapy sessions, a procedure based on a self-report measure, the Working Alliance Inventory (WAI), and an observational Rupture Resolution Rating System (3RS). We anticipated that the 3RS would detect more ruptures than the WAI. We examined the longitudinal data of 38 patient-therapist dyads in a cognitive-behavioral therapy condition. The sample included cases that did not complete treatment (dropped cases) as well as good-outcome and poor-outcome cases. At the end of each session, patients completed the WAI self-report questionnaire. Six judges were trained to observe and detect the occurrence of ruptures, and then rated 201 videotaped sessions. Longitudinal statistical models were applied to the data retrieved from the WAI questionnaires completed by patients. We found discrepancies in the ability of the two methods to detect rupture events with the observational 3RS detecting more ruptures than the WAI. Thus, the use of observational systems for the detection of alliance ruptures is crucial for effectively assessing the quality of the therapeutic alliance over the course of treatment. Furthermore, observational systems proven to detect ruptures can be used to improve clinical practice and training of new clinicians.

  16. Spontaneous rupture of a liver hemangioma. A case report.

    PubMed

    Guillén-Paredes, María Pilar; Martínez Fernández, Josefa; Morales González, Álvaro; Pardo-García, José Luis

    2016-07-01

    Spontaneous rupture of a liver hemangioma is a very uncommon disease, but extremely seriousness because it is associated to a 75% of mortality caused by hipovolemic shock. A case of an spontaneous rupture of liver hemangioma, which was previously unknow, is presented.

  17. Diverse rupture processes in the 2015 Peru deep earthquake doublet

    PubMed Central

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-01-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes. PMID:27386585

  18. Diverse rupture processes in the 2015 Peru deep earthquake doublet.

    PubMed

    Ye, Lingling; Lay, Thorne; Kanamori, Hiroo; Zhan, Zhongwen; Duputel, Zacharie

    2016-06-01

    Earthquakes in deeply subducted oceanic lithosphere can involve either brittle or dissipative ruptures. On 24 November 2015, two deep (606 and 622 km) magnitude 7.5 and 7.6 earthquakes occurred 316 s and 55 km apart. The first event (E1) was a brittle rupture with a sequence of comparable-size subevents extending unilaterally ~50 km southward with a rupture speed of ~4.5 km/s. This earthquake triggered several aftershocks to the north along with the other major event (E2), which had 40% larger seismic moment and the same duration (~20 s), but much smaller rupture area and lower rupture speed than E1, indicating a more dissipative rupture. A minor energy release ~12 s after E1 near the E2 hypocenter, possibly initiated by the S wave from E1, and a clear aftershock ~165 s after E1 also near the E2 hypocenter, suggest that E2 was likely dynamically triggered. Differences in deep earthquake rupture behavior are commonly attributed to variations in thermal state between subduction zones. However, the marked difference in rupture behavior of the nearby Peru doublet events suggests that local variations of stress state and material properties significantly contribute to diverse behavior of deep earthquakes.

  19. Tibialis posterior tendon rupture: a cause of rheumatoid flat foot.

    PubMed

    Downey, D J; Simkin, P A; Mack, L A; Richardson, M L; Kilcoyne, R F; Hansen, S T

    1988-03-01

    Flat foot, a major cause of foot pain and disability, may result from rupture of the tibialis posterior tendon. We describe 2 patients with rheumatoid arthritis who developed flat feet secondary to surgically confirmed tendon rupture, and we discuss the anatomy and diagnosis of this condition. In the second patient, we also present the results of tendon imaging with both magnetic resonance and ultrasound.

  20. Tracheal rupture in a cat: diagnosis by computed tomography.

    PubMed

    Bhandal, Jitender; Kuzma, Alan

    2008-06-01

    A cat was presented with a history of worsening generalized subcutaneous emphysema following dental prophylaxis. Tentative diagnosis of tracheal rupture was made. The location and extent of the tear was confirmed with the help of computed tomography. This is the 1st computed tomographic description of tracheal rupture in the veterinary literature.

  1. Transverse structure of the QCD string

    SciTech Connect

    Meyer, Harvey B.

    2010-11-15

    The characterization of the transverse structure of the QCD string is discussed. We formulate a conjecture as to how the stress-energy tensor of the underlying gauge theory couples to the string degrees of freedom. A consequence of the conjecture is that the energy density and the longitudinal-stress operators measure the distribution of the transverse position of the string, to leading order in the string fluctuations, whereas the transverse-stress operator does not. We interpret recent numerical measurements of the transverse size of the confining string and show that the difference of the energy and longitudinal-stress operators is a particularly natural probe at next-to-leading order. Second, we derive the constraints imposed by open-closed string duality on the transverse structure of the string. We show that a total of three independent ''gravitational'' form factors characterize the transverse profile of the closed string, and obtain the interpretation of recent effective string theory calculations: the square radius of a closed string of length {beta} defined from the slope of its gravitational form factor, is given by (d-1/2{pi}{sigma})log({beta}/4r{sub 0}) in d space dimensions. This is to be compared with the well-known result that the width of the open string at midpoint grows as (d-1/2{pi}{sigma})log(r/r{sub 0}). We also obtain predictions for transition form factors among closed-string states.

  2. 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

  3. Control of seafloor roughness on earthquake rupture behavior

    NASA Astrophysics Data System (ADS)

    Bilek, Susan L.; Schwartz, Susan Y.; Deshon, Heather R.

    2003-05-01

    Earthquake rupture complexity is described for three recent large underthrusting earthquakes along the Costa Rican subduction zone, the 1983 Osa, 1990 Nicoya Gulf, and 1999 Quepos events. These earthquakes occurred in regions characterized by distinctly different morphologic features on the subducting plate. The 1990 and 1999 events occurred along linear projections of subducting seamount chains and had fairly simple earthquake rupture histories. Both events are interpreted as failure of the basal contact of closely spaced isolated seamounts acting as asperities. In contrast, the 1983 event occurred along the subducting Cocos Ridge and had a complex rupture history. Comparison of rupture characteristics of these large underthrusting earthquakes with size and location of subducting features provides evidence that seamounts can be subducted to seismogenic depths and that variations in seafloor bathymetry of the subducting plate strongly influence the earthquake rupture process.

  4. 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.

  5. Incidence of plantar fascia ruptures following corticosteroid injection.

    PubMed

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

    2010-12-01

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

  6. Pneumatic Rupture of Rectosigmoid; a Case Report.

    PubMed

    Montazeri, Mohammad; Farhangi, Bahman; Montazeri, Mahmood

    2014-01-01

    Pneumatic rectosigmoid rapture is usually occurred following the inappropriate fun by direct entering a high volume of the air through the pneumatic device to the anus. Such an event was reported for the first time in 1904 by Stone. Diagnosis and treatment of such injuries are often delayed because of some social limitations and preventing the patient form explaining the event. Colon sigmoid rupture and pneumoperitoneum is one of the most dangerous and life treating complications of entering a high volume of the air to the rectum in a short time. There are only a few reports regarding the similar cases. Here, a case of pneumatic rectosigmoid rapture was reported in a 53 year-old male following an inappropriate fun.

  7. Unresponsive primipara after rupture of membranes.

    PubMed

    Buechel, Johanna; Berset, Andreas; Lehmann, Michael A; Lapaire, Olav

    2015-04-16

    Amniotic fluid embolism, also called anaphylactoid syndrome of pregnancy, is a rare but severe problem in obstetrics. It occurs in 8/100,000 births and the maternal mortality is up to 90%. We report the case of a patient with amniotic fluid embolism who was transferred to our hospital. The initial presentation was an unresponsive patient after spontaneous rupture of the membranes. The massive hypotension and coagulopathy as well as fetal bradycardia of 60 bpm led, after stabilisation of the mother, to an emergency caesarean section. The neonate expired hours later, despite neonatological intensive care. During the operation, we had to deal with massive bleeding due to the coagulopathy. Through interdisciplinary teamwork including Bakri postpartum balloon insertion through the obstetrics team, uterine artery embolism by the interventional radiologists and transfusion of blood products, the maternal life was saved and the patient was discharged 9 days after admission.

  8. Behçet's disease with ruptured anterior communicating artery aneurysm following ruptured thoracic aortic aneurysm.

    PubMed

    Ogata, Atsushi; Kawashima, Masatou; Matsushima, Toshio

    2013-01-01

    A 48-year-old Japanese woman with Behçet's disease suffered successive rupture of thoracic aortic and cerebral aneurysms within one year. The patient underwent successful surgical treatment for both aneurysms. Histological examination of the aneurysm walls revealed lymphocyte infiltration into the adventitia with smooth muscle cell hyperplasia in the thickened intima. This is an extremely unusual presentation of Behçet's disease associated with both cerebral and aortic aneurysms.

  9. Permanent disabilities in the displaced muscle from rupture of the long head tendon of the biceps.

    PubMed

    Deutch, Søren R; Gelineck, John; Johannsen, Hans Viggo; Sneppen, Otto

    2005-06-01

    Patients with a displaced muscle belly because of rupture of the long head biceps tendon were investigated for local pain and other disabilities, together with strength and endurance loss. Eleven patients (median age 59 years, minimum follow-up 6 months) were included, and minimum follow-up was 6 months. Magnetic resonance imaging (MRI) of both upper arms allowed investigation of muscle atrophy and evaluation of any other degenerative signs in the displaced muscle. All patients reported pain or disability locally in the displaced muscle in certain situations, and strength and endurance were reduced by 25%. MRI revealed the displaced muscle to be unreduced in size and with no signs of degeneration. Generally, operative reattachment of the displaced muscle is not advocated in middle-aged or older patients. In order to elucidate this subject, we present a retrospective consecutive series of patients with considerable disabilities in the displaced muscle belly independent of shoulder disabilities.

  10. Transverse Reinforcement of Adhesive Joints

    NASA Astrophysics Data System (ADS)

    Sapozhnikov, S.; Shakirov, A.

    2015-05-01

    The shear of single-lap adhesive joints causes significant peel stresses in the adhesive layer, which is a particularly urgent problem for low-modulus polyurethane compositions. An experimental and computational analysis of various methods for increasing the load-bearing capacity of the joints by their strengthening with metallic z-elements was carried out. This strengthening hinders their delamination by the action of peel stresses, which allows one to reduce the overall dimensions and weight of adhesive joints. Two main strengthening methods were considered: with steel tapping screws (of diameter 2.5 mm) and blind aluminum rivets (of diameter 4.0 mm). The peculiarity of the strengthening lies in the fact that z-elements of minimum available diameter were used for reducing the effect of stress concentrations on the strength of the joints. The test of specimens for each type of strengthening showed an average increase in the ultimate load by 40% for the threaded reinforcements and by 10% for the rivets. During an analysis of stress state of the joints by the FEM, the nonlinear behavior of constituent materials and stress concentration in the region of reinforcing elements were taken into account. The mechanical properties of the adhesive layer and the GFRP covering were determined in separate experiments. The analysis showed that the weight of the reinforced adhesive joints could be lowered by 20-25% relative to that of unreinforced ones without reducing their load-bearing capacity. An additional effect caused by using the threaded reinforcing elements was a more than threefold increase in their rigidity as compared with that of analogous nonreinforced ones.

  11. RESEARCH PAPERS : Transition process from nucleation to high-speed rupture propagation: scaling from stick-slip experiments tonatural earthquakes

    NASA Astrophysics Data System (ADS)

    Shibazaki, Bunichiro; Matsu'ura, Mitsuhiro

    1998-01-01

    The process of earthquake generation is governed by a coupled non-linear system consisting of the equation of motion in elastodynamics and a fault constitutive relation. On the basis of the results of stick-slip experiments we constructed a theoretical source model with a slip-dependent constitutive law. Using the theoretical source model, we simulated the transition process numerically from quasi-static nucleation to high-speed rupture propagation and succeeded in quantitatively explaining the three phases observed in stick-slip experiments, that is very slow (1 cm s-1 ) quasi-static nucleation preceding the onset of dynamic rupture, dynamic but slow (10 m s-1 ) rupture growth without seismic-wave radiation, and subsequent high-speed (2 km s-1 ) rupture propagation. Theoretical computation of far-field waveforms with this model shows that a slow initial phase preceding the main P phase expected from a classical source model is radiated in the accelerating stage from the slow dynamic rupture growth to the high-speed rupture propagation. On the assumption that the physical law governing rupture processes in natural earthquakes is essentially the same as that in stick-slip events, we scaled the theoretical source model explaining the stick-slip experiments to the case of natural earthquakes so that the scaled source model explains the observed average stress drop, the critical nucleation-zone size, and the duration of the slow initial phase well. The physical parameters prescribing the source model are the weak-zone size L , the critical weakening displacement Dc , the breakdown strength drop τb , and the rigidity μ of the surrounding elastic medium. In scaling these parameters, we held a non-dimensional controlling parameter μ' = (μDc )/(τb L ) in numerical simulation constant. From the results of scaling we found the following fundamental relations between the source parameters: (1) the critical weakening displacement Dc is in proportion to the weak-zone size

  12. Transverse beam emittance measurement using quadrupole variation at KIRAMS-430

    NASA Astrophysics Data System (ADS)

    An, Dong Hyun; Hahn, Garam; Park, Chawon

    2015-02-01

    In order to produce a 430 MeV/u carbon ion (12 C 6+) beam for medical therapy, the Korea Institute of Radiological & Medical Sciences (KIRAMS) has carried out the development of a superconducting isochronous cyclotron, the KIRAMS-430. At the extraction of the cyclotron, an Energy Selection System (ESS) is located to modulate the fixed beam energy and to drive the ion beam through High Energy Beam Transport (HEBT) into the treatment room. The beam emittance at the ion beamline is to be measured to provide information on designing a beam with high quality. The well-known quadrupole variation method was used to determine the feasibility of measuring the transverse beam emittance. The beam size measured at the beam profile monitor (BPM) is to be utilized and the transformation of beam by transfer matrix is to be applied being taken under various transport condition of varying quadrupole magnetic strength. Two different methods where beam optics are based on the linear matrix formalism and particle tracking with a 3-D magnetic field distribution obtained by using OPERA3D TOSCA, are applied to transport the beam. The fittings for the transformation parameters are used to estimate the transverse emittance and the twiss parameters at the entrance of the quadrupole in the ESS. Including several systematic studies, we conclude that within the uncertainty the estimated emittances are consistent with the ones calculated by using Monte Carlo simulations.

  13. Effect of Noise on DNA Sequencing via Transverse Electronic Transport

    PubMed Central

    Krems, Matt; Zwolak, Michael; Pershin, Yuriy V.; Di Ventra, Massimiliano

    2009-01-01

    Abstract Previous theoretical studies have shown that measuring the transverse current across DNA strands while they translocate through a nanopore or channel may provide a statistically distinguishable signature of the DNA bases, and may thus allow for rapid DNA sequencing. However, fluctuations of the environment, such as ionic and DNA motion, introduce important scattering processes that may affect the viability of this approach to sequencing. To understand this issue, we have analyzed a simple model that captures the role of this complex environment in electronic dephasing and its ability to remove charge carriers from current-carrying states. We find that these effects do not strongly influence the current distributions due to the off-resonant nature of tunneling through the nucleotides—a result we expect to be a common feature of transport in molecular junctions. In particular, only large scattering strengths, as compared to the energetic gap between the molecular states and the Fermi level, significantly alter the form of the current distributions. Since this gap itself is quite large, the current distributions remain protected from this type of noise, further supporting the possibility of using transverse electronic transport measurements for DNA sequencing. PMID:19804730

  14. Theory of Slow Waves in Transversely Nonuniform Plasma Waveguides

    SciTech Connect

    Kuzelev, M.V.; Romanov, R.V.; Rukhadze, A.A.

    2005-02-15

    A general method is developed for a numerical analysis of the frequency spectra of internal, internal-surface, and surface slow waves in a waveguide with transverse plasma density variations. For waveguides with a piecewise constant plasma filling, the spectra of slow waves are thoroughly examined in the limits of an infinitely weak and an infinitely strong external magnetic field. For a smooth plasma density profile, the frequency spectrum of long-wavelength surface waves remains unchanged, but a slow damping rate appears that is caused by the conversion of the surface waves into internal plasma waves at the plasma resonance point. As for short-wavelength internal waves, they are strongly damped by this effect. It is pointed out that, for annular plasma geometry, which is of interest from the experimental point of view, the spectrum of the surface waves depends weakly on the magnetic field strength in the waveguide.

  15. Finite Element Simulations of Dynamic Shear Rupture Experiments and Path Selection Along Branched Faults

    NASA Astrophysics Data System (ADS)

    Templeton, E. L.; Baudet, A.; Bhat, H. S.; Dmowska, R.; Rice, J. R.; Rosakis, A. J.; Rousseau, C. E.

    2005-12-01

    ) a cohesive part, c = c(Δ u) (where Δ u = slip) of the shear strength that is insensitive to compressive normal stress σ, and (2) a frictional part f σ, with friction coefficient f = f(Δ u). The analyses of impact loading, and rupture nucleation and propagation were carried out in a 2D plane stress framework. A set of studies of slip weakening parameters and impact velocity were done to investigate the relationship between the strength of the interface and the speed of rupture propagation. For a branch on the extensional side of the main fault, increasing f(0) decreases the propagation speed on the continuation of the straight main fault while increasing speed on the branch. Whether the rupture is propagating at an intersonic or sub-Rayleigh speed when it reaches the branching junction has a large effect on the nature of rupture propagation along the inclined path. While not achieving perfect agreement with the experimental measurements, principal features observed in dynamic isochromatic line patterns were reproduced.

  16. Targets for Earthscope (USArray) in Southern California: Mid-Crustal Decollements Beneath the Transverse Ranges

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.; Langenheim, V. E.; Howard, K. A.; Catchings, R. D.; Okaya, D. A.; Clayton, R. W.; Nicholson, C.

    2002-12-01

    The Big Bend region of the San Andreas fault, in southern California, promises to be a productive region to investigate the linkage of strike-slip and compressional tectonics using flexible arrays under the USArray component of Earthscope. This region, occupied in large part by the Transverse Ranges, has been investigated recently by two active- and passive-source seismic-imaging surveys approximately 70 km apart (Los Angeles Region Seismic Experiment--LARSE94 and LARSE99). These surveys imaged mid-crustal reflective zones, interpreted as decollements, that originate at the San Andreas fault, extend southward beneath the Transverse Ranges and sedimentary basins of the Los Angeles region, and connect or appear to connect upward to compressional faults, including the exposed Sierra Madre and San Gabriel faults and the blind thrust faults that ruptured in the 1971 San Fernando and 1987 Whittier Narrows earthquakes. In the Transverse Ranges north of the Whittier Narrows epicenter, the reflective zone contains anomalously bright reflections and is subhorizontal (LARSE94); in the Transverse Ranges north of the San Fernando epicenter, the reflective zone contains clear but not anomalous reflections and dips moderately northward (LARSE99). These interpreted decollements may be continuous with one another. To test this possibility, we propose to image the region between the two LARSE surveys, through the vicinity of downtown Los Angeles, where such a decollement may be connected upward to postulated blind thrust faults beneath the Elysian Park anticline. We propose a seismic-imaging survey that begins at the coast, approximately follows the Los Angeles river northward, crosses the Elysian Park anticline, passes through the triple junction of the Hollywood, Verdugo, and Raymond faults, and passes over the Transverse Ranges to the Mojave Desert. In addition to this proposed transect, there are at least two other proposed transects, both east and west of the Los Angeles region

  17. Uterine rupture in pregnancies following myomectomy: A multicenter case series

    PubMed Central

    Kim, Hee-Sun; Oh, Soo-Young; Choi, Suk-Joo; Park, Hyun-Soo; Cho, Geum-Joon; Chung, Jin-Hoon; Seo, Yong-Soo; Jung, Sun-Young; Kim, Jung-Eun; Chae, Su-Hyun

    2016-01-01

    Objective The purpose of this case series was to retrospectively examine records of cases with uterine rupture in pregnancies following myomectomy and to describe the clinical features and pregnancy outcomes. Methods This study was conducted as a multicenter case series. The patient databases at 7 tertiary hospitals were queried. Records of patients with a diagnosis of uterine rupture in the pregnancy following myomectomy between January 2012 and December 2014 were retrospectively collected. The uterine rupture cases enrolled in this study were defined as follows: through-and-through uterine rupture or tear of the uterine muscle and serosa, occurrence from 24+0 to 41+6 weeks’ gestation, singleton pregnancy, and previous laparoscopic myomectomy (LSM) or laparotomic myomectomy (LTM) status. Results Fourteen pregnant women experienced uterine rupture during their pregnancy after LSM or LTM. Preterm delivery of less than 34 weeks’ gestation occurred in 5 cases, while intrauterine fetal death occurred in 3, and 3 cases had fetal distress. Of the 14 uterine rupture cases, none occurred during labor. All mothers survived and had no sequelae, unlike the perinatal outcomes, although they were receiving blood transfusion or treatment for uterine artery embolization because of uterine atony or massive hemorrhage. Conclusion In women of childbearing age who are scheduled to undergo LTM or LSM, the potential risk of uterine rupture on subsequent pregnancy should be explained before surgery. Pregnancy in women after myomectomy should be carefully observed, and they should be adequately counseled during this period. PMID:27896247

  18. Factors Controlling Stress Rupture of Fiber-Reinforced Ceramic Composites

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    The successful application of fiber-reinforced ceramic matrix composites (CMC) depends strongly on maximizing material rupture life over a wide range of temperatures and applied stresses. The objective of this paper is to examine the various intrinsic and extrinsic factors that control the high-temperature stress rupture of CMC for stresses below and above those required for cracking of the 0 C plies (Regions I and II, respectively). Using creep-rupture results for a variety of ceramic fibers and rupture data for CMC reinforced by these fibers, it is shown that in those cases where the matrix carries little structural load, CMC rupture conditions can be predicted very well from the fiber behavior measured under the appropriate test environment. As such, one can then examine the intrinsic characteristics of the fibers in order to develop design guidelines for selecting fibers and fiber microstructures in order to maximize CMC rupture life. For those cases where the fiber interfacial coatings are unstable in the test environment, CMC lives are generally worse than those predicted by fiber behavior alone. For those cases where the matrix can support structural load, CMC life can even be greater provided matrix creep behavior is properly controlled. Thus the achievement of long CMC rupture life requires understanding and optimizing the behavior of all constituents in the proper manner.

  19. 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

    2014-10-08

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

  20. Nucleon Spin Structure: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-02-01

    Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

  1. Studies on Creep Deformation and Rupture Behavior of 316LN SS Multi-Pass Weld Joints Fabricated with Two Different Electrode Sizes

    NASA Astrophysics Data System (ADS)

    Vijayanand, V. D.; Kumar, J. Ganesh; Parida, P. K.; Ganesan, V.; Laha, K.

    2017-02-01

    Effect of electrode size on creep deformation and rupture behavior has been assessed by carrying out creep tests at 923 K (650 °C) over the stress range 140 to 225 MPa on 316LN stainless steel weld joints fabricated employing 2.5 and 4 mm diameter electrodes. The multi-pass welding technique not only changes the morphology of delta ferrite from vermicular to globular in the previous weld bead region near to the weld bead interface, but also subjects the region to thermo-mechanical heat treatment to generate appreciable strength gradient. Electron backscatter diffraction analysis revealed significant localized strain gradients in regions adjoining the weld pass interface for the joint fabricated with large electrode size. Larger electrode diameter joint exhibited higher creep rupture strength than the smaller diameter electrode joint. However, both the joints had lower creep rupture strength than the base metal. Failure in the joints was associated with microstructural instability in the fusion zone, and the vermicular delta ferrite zone was more prone to creep cavitation. Larger electrode diameter joint was found to be more resistant to failure caused by creep cavitation than the smaller diameter electrode joint. This has been attributed to the larger strength gradient between the beads and significant separation between the cavity prone vermicular delta ferrite zones which hindered the cavity growth. Close proximity of cavitated zones in smaller electrode joint facilitated their faster coalescence leading to more reduction in creep rupture strength. Failure location in the joints was found to depend on the electrode size and applied stress. The change in failure location has been assessed on performing finite element analysis of stress distribution across the joint on incorporating tensile and creep strengths of different constituents of joints, estimated by ball indentation and impression creep testing techniques.

  2. Minimum Energy Path to Membrane Pore Formation and Rupture

    NASA Astrophysics Data System (ADS)

    Ting, Christina L.; Appelö, Daniel; Wang, Zhen-Gang

    2011-04-01

    We combine dynamic self-consistent field theory with the string method to calculate the minimum energy path to membrane pore formation and rupture. In the regime where nucleation can occur on experimentally relevant time scales, the structure of the critical nucleus is between a solvophilic stalk and a locally thinned membrane. Classical nucleation theory fails to capture these molecular details and significantly overestimates the free energy barrier. Our results suggest that thermally nucleated rupture may be an important factor for the low rupture strains observed in lipid membranes.

  3. Rupture of all digital flexors following Colles' fracture.

    PubMed

    Iyer, Srinivasan; Basu, Indraneil; Kaba, Rahim; Pabari, Amit

    2012-10-01

    Flexor tendon rupture following a Colles' fracture is a rare complication with only a handful of cases reported since the initial report in 1932. We present a case in which all digital flexor tendons ruptured within 6 months of a Colles' fracture. Previous reported cases have demonstrated rupture of either the radial or ulnar digital flexors but this case is the first in which all the digital flexors have been involved. This case report highlights the clinical implications of this rare occurrence and stresses the importance of accurate reduction and thorough clinical examination following bony injuries to the wrist.

  4. Surviving Right Atrial Rupture From Blunt Thoracic Trauma After Pericardiectomy.

    PubMed

    Lajevardi, Sepehr Seyed; Galougahi, Keyvan Karimi; Nova, George; Marshman, David

    2016-02-01

    Right atrial rupture secondary to blunt trauma is exceedingly rare. We present a case report of blunt chest trauma and right atrial rupture in a patient with a background of pericardiectomy that were successfully managed surgically. Right atrial rupture must be considered as a differential diagnosis in patients with blunt chest trauma. In patients with previous pericardiectomy, this injury may manifest with massive hemothorax, and insertion of a chest drain should be performed with extreme caution. In our experience, urgent exploratory thoracotomy and repair of the defect are the mainstays of acute management.

  5. Acute partial rupture of the common extensor tendon.

    PubMed

    Kachrimanis, G; Papadopoulou, O

    2010-06-01

    Rupture of the common extensor tendon is the most common acute tendon injury of the elbow. The authors describe a case of a patient with a clinical history of tendinopathy caused by functional overload of the common extensor tendon, treated also with infiltrations of steroids, and subsequent partial rupture of the tendon during sport activity. The diagnosis was made clinically and at ultrasound (US) examination; US follow-up after some time showed the healing of the lesion. This case confirms that injections of steroids may be a contributory cause of tendon rupture, and emphasizes the sensitivity and specificity of US in the study of pathologies of the elbow tendons.

  6. Nuclear envelope rupture drives genome instability in cancer

    PubMed Central

    Lim, Sanghee; Quinton, Ryan J.; Ganem, Neil J.

    2016-01-01

    The nuclear envelope, composed of two lipid bilayers and numerous accessory proteins, has evolved to house the genetic material of all eukaryotic cells. In so doing, the nuclear envelope provides a physical barrier between chromosomes and the cytoplasm. Once believed to be highly stable, recent studies demonstrate that the nuclear envelope is prone to rupture. These rupture events expose chromosomal DNA to the cytoplasmic environment and have the capacity to promote DNA damage. Thus nuclear rupture may be an unappreciated mechanism of mutagenesis. PMID:27799497

  7. Bilateral simultaneous infrapatellar tendon ruptures: a case study.

    PubMed

    Noteboom, J T; Lester, M N

    1994-09-01

    This case study reports on a patient with a diagnosis of bilateral patellar tendon ruptures. Bilateral ruptures of the infrapatellar tendons are rare occurrences; approximately 20 cases have been reported in the medical literature. Much of the medical literature concentrates on surgical repair, immediate postoperative follow-up, and final outcome. There is a void in the literature concerning the rehabilitative process of these patients. The subject of this study is a 26-year-old male former collegiate athlete who suffered simultaneous bilateral patellar tendon ruptures while jumping. A rehabilitation model is provided that may assist others treating patients with similar conditions.

  8. [Spontaneous splenic rupture in the second quarter of pregnancy].

    PubMed

    Brocas, E; Tenaillon, A

    2002-03-01

    We report the case of a 33 year-old woman at the second quarter of pregnancy, with known brain aneurysm admitted in intensive care unit for sudden coma. The coma was not related to a rupture of the brain aneurysm but to a serious haemorrhagic shock caused by a spontaneous splenic rupture. This case report illustrates the difficulty of this unrecognized diagnosis and reminds us to suspect a spontaneous splenic rupture in front of any pregnant woman with atypic abdominal pain and haemorrhagic shock.

  9. High strength nickel-chromium-iron austenitic alloy

    DOEpatents

    Gibson, Robert C.; Korenko, Michael K.

    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.

  10. Transverse Spin Relaxation in Liquid X

    SciTech Connect

    Romalis, M. V.; Ledbetter, M. P.

    2001-08-06

    Using spin-echo NMR techniques we study the transverse spin relaxation of hyperpolarized liquid X{sup 129}e in a spherical cell. We observe an instability of the transverse magnetization due to dipolar fields produced by liquid X{sup 129}e , and find that imperfections in the {pi} pulses of the spin-echo sequence suppress this instability. A simple perturbative model of this effect is in good agreement with the data. We obtain a transverse spin relaxation time of 1300sec in liquid X{sup 129}e , and discuss applications of hyperpolarized liquid X{sup 129}e as a sensitive magnetic gradiometer and for a permanent electric dipole moment search.

  11. Transverse Bursts in Inclined Layer Convection: Experiment

    NASA Astrophysics Data System (ADS)

    Daniels, Karen; Wiener, Richard; Bodenschatz, Eberhard

    2002-03-01

    We report experimental results on inclined layer convection in a fluid of Prandtl number σ ≈ 1. A codimension-two point divides regions of buoyancy-driven convection (longitudinal rolls) at lower angles from shear-driven convection (transverse rolls) at higher angles (Daniels et al. PRL 84: 5320, 2000). In the region of buoyancy-driven convection, near the codimension-two point, we observe longitudinal rolls with intermittent, localized, subharmonic transverse bursts. The patterns are spatiotemporally chaotic. With increasing temperature difference the bursts increase in duration and number. We examine the details of the bursting process (e.g. the energy of longitudinal, transverse, and mixed modes) and compare our results to bursting processes in other systems. This work is supported by the National Science Foundation under grant DMR-0072077 and the IGERT program in nonlinear systems, grant DGE-9870631.

  12. Efficient modeling in transversely isotropic inhomogeneous media

    SciTech Connect

    Alkhalifah, T.

    1993-11-01

    An efficient modeling technique for transversely isotropic, inhomogeneous media, is developed using a mix of analytical equations and numerical calculations. The analytic equation for the raypath in a factorized transversely isotropic (FTI) media with linear velocity variation, derived by Shearer and Chapman, is used to trace between two points. In addition, I derive an analytical equation for geometrical spreading in FTI media that aids in preserving program efficiency; however, the traveltime is calculated numerically. I then generalize the method to treat general transversely isotropic (TI) media that are not factorized anisotropic inhomogeneous by perturbing the FTI traveltimes, following the perturbation ideas of Cerveny and Filho. A Kirchhoff-summation-based program relying on Trorey`s (1970) diffraction method is used to generate synthetic seismograms for such a medium. For the type of velocity models treated, the program is much more efficient than finite-difference and general ray-trace modeling techniques.

  13. Quantification of Fault-Zone Plasticity Effects with Spontaneous Rupture Simulations

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Day, S. M.; Cui, Y.

    2017-02-01

    Previous studies have shown that plastic yielding in crustal rocks in the fault zone may impose a physical limit to extreme ground motions. We explore the effects of fault-zone non-linearity on peak ground velocities (PGVs) by simulating a suite of surface-rupturing strike-slip earthquakes in a medium governed by Drucker-Prager plasticity using the AWP-ODC finite-difference code. Our simulations cover magnitudes ranging from 6.5 to 8.0, three different rock strength models, and average stress drops of 3.5 and 7.0 MPa, with a maximum frequency of 1 Hz and a minimum shear-wave velocity of 500 m/s. Friction angles and cohesions in our rock models are based on strength criteria which are frequently used for fractured rock masses in civil and mining engineering. For an average stress drop of 3.5 MPa, plastic yielding reduces near-fault PGVs by 15-30% in pre-fractured, low strength rock, but less than 1% in massive, high-quality rock. These reductions are almost insensitive to magnitude. If the stress drop is doubled, plasticity reduces near-fault PGVs by 38-45% and 5-15% in rocks of low and high strength, respectively. Because non-linearity reduces slip rates and static slip near the surface, plasticity acts in addition to, and may partially be emulated by, a shallow velocity-strengthening layer. The effects of plasticity are exacerbated if a fault damage zone with reduced shear-wave velocities and reduced rock strength is present. In the linear case, fault-zone trapped waves result in higher near-surface peak slip rates and ground velocities compared to simulations without a low-velocity zone. These amplifications are balanced out by fault-zone plasticity if rocks in the damage zone exhibit low-to-moderate strength throughout the depth extent of the low-velocity zone (˜ 5 km). We also perform dynamic non-linear simulations of a high stress drop (8 MPa) M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. Non-linearity in

  14. Evolution of transverse modes in FELIX macropulses

    SciTech Connect

    Weits, H.H.; Lin, L.; Werkhoven, G.H.C. van

    1995-12-31

    We present ringdown measurements of both the intracavity beam, using a low reflection beamsplitter, as well as the hole-outcoupled beam of FELIX, the intracavity measurements being taken at various sets of transverse coordinates. Recent measurements show a significant difference in the decay of the signals at different radial positions, suggesting the presence of higher order transverse modes. The formation of transverse modes depends on the properties of the cold cavity and its losses (i.e. resonator parameters, diffraction and outcoupling at the hole, absorption and edge losses on the mirrors, waveguide clipping), as well as on the gain mechanism. Both simulations with the axisymmetric ELIXER code and previous hole-outcoupled measurements indicated a substantial energy content of the 2nd or 4th Gauss-Laguerre (GL) mode for the 20-30 {mu}m regime of FELIX. Moreover, as FELIX has a phase degenerate cavity, the fundamental and higher order transverse modes can interplay to create a reduced outcoupling efficiency at the hole. For example, in contrast to the decay rate of 13% per roundtrip that we would expect for a pure gaussian beam when we include a loss of 6% for the reflection at the intracavity beamsplitter, recent simulations indicate a decay rate as high as 23% of the hole-outcoupled signal. In this case the 2nd order GL mode contains 30% of the total intracavity power. The effect of transverse modes on subpulses in the limit cycle regime is an interesting aspect. As soon as a subpulse is losing contact with the electrons, its transverse pattern will exhibit an on-axis hole after a few roundtrips, according to the simulations. This process could mean that the subpulses are less pronounced in the hole-outcoupled signal of FELIX 1.

  15. Chatter in a transverse grinding process

    NASA Astrophysics Data System (ADS)

    Yan, Yao; Xu, Jian; Wiercigroch, Marian

    2014-02-01

    In transverse grinding, the wheel moves along the workpiece, which induces unique grinding dynamics. To understand these dynamic phenomena, specifically the grinding chatter, a new dynamical model of the process is proposed, in which the wheel position is assumed to be quasi-static since the transverse wheel velocity is small. From the stability and bifurcation analyses of the chatter vibration, it appears that the dynamics of the process is governed by the quasi-static interactions. Moreover, the obtained results also show that the wheel and workpiece chatters are quite different, having continuous and intermittent characters respectively.

  16. Fractional variational calculus and the transversality conditions

    NASA Astrophysics Data System (ADS)

    Agrawal, O. P.

    2006-08-01

    This paper presents the Euler-Lagrange equations and the transversality conditions for fractional variational problems. The fractional derivatives are defined in the sense of Riemann-Liouville and Caputo. The connection between the transversality conditions and the natural boundary conditions necessary to solve a fractional differential equation is examined. It is demonstrated that fractional boundary conditions may be necessary even when the problem is defined in terms of the Caputo derivative. Furthermore, both fractional derivatives (the Riemann-Liouville and the Caputo) arise in the formulations, even when the fractional variational problem is defined in terms of one fractional derivative only. Examples are presented to demonstrate the applications of the formulations.

  17. [The transversality and health promotion schools].

    PubMed

    Gavidia Catalán, V

    2001-01-01

    The following article shows the evolution of the schools contribution to the Health Education of children and young people. Moving on from the traditional concept of health, today, Health Education has a general and global meaning, which encompasses all of the physical, psychological and social aspects of health. These aspects define the characteristics of the "Healthy School". The need to broach the "transversal subject" offers schools the possibility of developing "transversality" in the Health Education. Finally, the concept of promoting health defines, together with the other subjects, that which we understand by "the heath promotion schools", which attempts to progress the full integration of schools in the society in which they are located.

  18. Transverse dimension and long-term stability.

    PubMed

    Vanarsdall, R L

    1999-09-01

    This article emphasizes the critical importance of the skeletal differential between the width of the maxilla and the width of the mandible. Undiagnosed transverse discrepancy leads to adverse periodontal response, unstable dental camouflage, and less than optimal dentofacial esthetics. Hundreds of adult retreatment patients corrected for significant maxillary transverse deficiency using surgically assisted maxillary expansion (similar to osseous distraction) has produced excellent stability. Eliciting tooth movement for children (orthopedics, lip bumper, Cetlin plate) in all three planes of space by muscles, eruption, and growth, develops the broader arch form (without the mechanical forces of fixed or removable appliances) and has also demonstrated impressive long term stability.

  19. Transverse dune trailing ridges and vegetation succession

    NASA Astrophysics Data System (ADS)

    Hesp, Patrick A.; ‘Marisa' Martinez, M. L.

    2008-07-01

    We describe the evolution of, and vegetation succession on, a previously undescribed landform: transverse dune trailing ridges at El Farallón transgressive dunefield in the state of Veracruz, Mexico. Three-dimensional clinometer/compass and tape topographic surveys were conducted in conjunction with 1 m 2 contiguous percent cover and presence/absence vegetation survey transects at eight locations across two adjacent trailing ridges. At the study site, and elsewhere, the transverse dune trailing ridges are formed by vegetation colonization of the lateral margins of active transverse, barchanoidal transverse, and aklé or network dunes. For simplicity, all trailing ridges formed from these dune types are referred to as transverse dune trailing ridges. Because there are several transverse dunes in the dunefield, multiple trailing ridges can be formed at one time. Two adjacent trailing ridges were examined. The shortest length ridge was 70 m long, and evolving from a 2.5 m-high transverse dune, while the longer ridge was 140 m long, and evolving from an 8 m-high dune. Trailing ridge length is a proxy measure of ridge age, since the longer the ridge, the greater the length of time since initial formation. With increasing age or distance upwind, species diversity increased, as well as species horizontal extent and percent cover. In turn, the degree of bare sand decreased. Overall, the data indicate a successional trend in the vegetation presence and cover with increasing age upwind. Those species most tolerant to burial ( Croton and Palafoxia) begin the process of trailing ridge formation. Ipomoea and Canavalia are less tolerant to burial and also are typically the next colonizing species. Trachypogon does not tolerate sand burial or deposition very well and only appears after significant stabilization has taken place. The ridges display a moderately defined successional sequence in plant colonization and percentage cover with time (and upwind distance). They are

  20. Program Computes Universal Transverse Mercator Projection

    NASA Technical Reports Server (NTRS)

    Wallis, David E.

    1991-01-01

    Computer program produces Gauss-Kruger (constant meridional scale) transverse Mercator projection, used to construct U.S. Army's universal transverse Mercator (UTM) grid system. Capable of mapping entire Northern Hemisphere of Earth (and, by symmetry of projection, entire Earth) accurately with respect to single principal meridian. Mathematically insensitive to proximity to pole or equator and insensitive to departure of meridian from central meridian. Useful to any mapmaking agency. FORTRAN 77 program developed on IBM PC-series computer equipped with Intel Math Coprocessor.

  1. Development of a high strength hot isostatically pressed /HIP/ disk alloy, MERL 76

    NASA Technical Reports Server (NTRS)

    Evans, D. J.; Eng, R. D.

    1980-01-01

    A nickel-based powder metal disk alloy developed for use in advanced commercial gas turbines is described. Consideration is given to final alloy chemistry modifications made to achieve a desirable balance between tensile strength and stress rupture life and ductility. The effects of post-consolidation heat treatment are discussed, the preliminary mechanical properties obtained from full-scale turbine disks are presented.

  2. Effect of water on long-term weakening preceding rupture of crustal faults

    NASA Astrophysics Data System (ADS)

    Masuda, K.; Arai, T.; Fujimoto, K.; Takahashi, M.; Shigematsu, N.

    2010-12-01

    Fault strength is a critical parameter in studies of crustal mechanics and for the prediction of earthquake hazards. The strengths of crustal faults inferred from borehole heat flow measurements and maximum stress orientations in the crust are less than those determined from laboratory measurements. Suggested causes of the weakening of faults include high fluid pressures, dynamic processes, or the presence of weak fault gouge. However, long-term changes of fault strength cannot be directly monitored using geophysical techniques, so an explanation for fault weakening remains an unsolved problem. We provide laboratory evidence that long-term weakening of the frictional strength of faults is caused by micro-fracturing at asperity contacts, which is a result of crack growth at subcritical stress levels. Our model suggests that long-term reductions of fault strength are related to chemical reactions that take place in the presence of water. For our measurements of friction on rupture surfaces in the presence of water, we increased temperatures to accelerate reaction processes so that they were observable at laboratory time-scales. In the presence of water, frictional strength decreased as temperature increased, whereas it changed little in the absence of water. The observed decreases in frictional strength were facilitated by chemical processes, rather than by physical processes governed by the effective pressure law. These observations suggest that chemical processes such as stress corrosion play an important role in long-term fault weakening. In addition to long-term monitoring of fault zones, we need to investigate long-term processes that cannot be observed during a human lifetime if we are to understand earthquake occurrences in the deep crust.

  3. Dynamic Tension Spectroscopy and Strength of Biomembranes

    PubMed Central

    Evans, Evan; Heinrich, Volkmar; Ludwig, Florian; Rawicz, Wieslawa

    2003-01-01

    Rupturing fluid membrane vesicles with a steady ramp of micropipette suction produces a distribution of breakage tensions governed by the kinetic process of membrane failure. When plotted as a function of log(tension loading rate), the locations of distribution peaks define a dynamic tension spectrum with distinct regimes that reflect passage of prominent energy barriers along the kinetic pathway. Using tests on five types of giant phosphatidylcholine lipid vesicles over loading rates(tension/time) from 0.01–100 mN/m/s, we show that the kinetic process of membrane breakage can be modeled by a causal sequence of two thermally-activated transitions. At fast loading rates, a steep linear regime appears in each spectrum which implies that membrane failure starts with nucleation of a rare precursor defect. The slope and projected intercept of this regime are set by defect size and frequency of spontaneous formation, respectively. But at slow loading rates, each spectrum crosses over to a shallow-curved regime where rupture tension changes weakly with rate. This regime is predicted by the classical cavitation theory for opening an unstable hole in a two-dimensional film within the lifetime of the defect state. Under slow loading, membrane edge energy and the frequency scale for thermal fluctuations in hole size are the principal factors that govern the level of tension at failure. To critically test the model and obtain the parameters governing the rates of transition under stress, distributions of rupture tension were computed and matched to the measured histograms through solution of the kinetic master (Markov) equations for defect formation and annihilation or evolution to an unstable hole under a ramp of tension. As key predictors of membrane strength, the results for spontaneous frequencies of defect formation and hole edge energies were found to correlate with membrane thicknesses and elastic bending moduli, respectively. PMID:14507698

  4. 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.

  5. Extensor tendon ruptures after total knee arthroplasty.

    PubMed

    Bonnin, M; Lustig, S; Huten, D

    2016-02-01

    Extensor tendon rupture is a rare but serious complication after total knee arthroplasty (TKA) that impairs active knee extension, thereby severely affecting knee function. Surgery is usually required. Surgical options range from simple suturing to allograft reconstruction of the entire extensor mechanism and include intermediate methods such as reconstruction using neighbouring tendons or muscles, synthetic ligament implantation, and partial allograft repair. Simple suturing carries a high failure rate and should therefore be routinely combined with tissue augmentation using a neighbouring tendon or a synthetic ligament. After allograft reconstruction, outcomes are variable and long-term complications common. Salvage procedures for managing the most severe cases after allograft failure involve reconstruction using gastrocnemius or vastus flaps. Regardless of the technique used, suturing must be performed under tension, with the knee fully extended, and rehabilitation must be conducted with great caution. Weaknesses of available case-series studies include small sample sizes, heterogeneity, and inadequate follow-up duration. All treatment options are associated with substantial failure rates. The patient should be informed of this fact and plans made for a salvage option. Here, the main techniques and their outcomes are discussed, and a therapeutic strategy is suggested.

  6. Design procedure prevents PE pipe rupture

    SciTech Connect

    Grigory, S.C.

    1995-12-01

    A rupture prevention design procedure for plastic gas distribution pipe is nearing completion at Southwest Research Institute (SWRI). Given the pipe size, polyethylene (PE) resin, and minimum operating temperature, the maximum safe operating pressure can be determined for which rapid crack propagation (RCP) cannot occur. A computer program, called PFRAC, has been developed for this purpose and uses Charpy energy as the measurement of fracture toughness of PE. Present efforts, however, involve replacing Charpy energy with a dynamic toughness measurement obtained from the Small Scale Steady State (S4) test that is required in ISO 4437. The program is being financed by the Gas Research Institute, Chicago. RCP events in PE pipe have been rare primarily because operating pressures are low and pipe diameters are small in most gas distribution systems. However, controlled RCP experiments in the US and other countries clearly demonstrate that as the gas industry moves toward higher line pressures and larger diameters, the likelihood of an RCP event increases. Recognizing this, ISO includes a requirement for RCP in its ISO 4437 standard for pipe greater than 10 inches in diameter or operating pressures greater than 58 psig. The S4 test may be used on all pipe diameters. A full scale test or the S4 test can be used on pipe greater than 10 inches diameter.

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

    PubMed

    Öz, Necdet; Kargı, Ahmet Bülent; Zeybek, Arife

    2015-06-01

    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.

  8. Perturbative calculations of quantum spin tunneling in effective spin systems with a transversal magnetic field and transversal anisotropy

    NASA Astrophysics Data System (ADS)

    Krizanac, M.; Vedmedenko, E. Y.; Wiesendanger, R.

    2017-01-01

    We present a perturbative approach for the resonant tunnel splittings of an arbitrary effective single spin system. The Hamiltonian of such a system contains a uniaxial anisotropy, a transversal magnetic field and a second-order transversal anisotropy. Further, we investigate the influence of the transversal magnetic field on the energy splittings for higher integer quantum spins and we introduce an exact formula, which defines values of the transversal magnetic field, the transversal anisotropy and the uniaxial anisotropy where the contribution of the transversal magnetic field to the energy splitting is at least equal to the contribution of the transversal anisotropy.

  9. Creep Deformation and Rupture Behavior of Single- and Dual-Pass 316LN Stainless-Steel-Activated TIG Weld Joints

    NASA Astrophysics Data System (ADS)

    Vijayanand, V. D.; Vasudevan, M.; Ganesan, V.; Parameswaran, P.; Laha, K.; Bhaduri, A. K.

    2016-06-01

    Creep deformation and rupture behavior of single-pass and dual-pass 316LN stainless steel (SS) weld joints fabricated by an autogenous activated tungsten inert gas welding process have been assessed by performing metallography, hardness, and conventional and impression creep tests. The fusion zone of the single-pass joint consisted of columnar zones adjacent to base metals with a central equiaxed zone, which have been modified extensively by the thermal cycle of the second pass in the dual-pass joint. The equiaxed zone in the single-pass joint, as well as in the second pass of the dual-pass joint, displayed the lowest hardness in the joints. In the dual-pass joint, the equiaxed zone of the first pass had hardness comparable to the columnar zone. The hardness variations in the joints influenced the creep deformation. The equiaxed and columnar zone in the first pass of the dual-pass joint was more creep resistant than that of the second pass. Both joints possessed lower creep rupture life than the base metal. However, the creep rupture life of the dual-pass joint was about twofolds more than that of the single-pass joint. Creep failure in the single-pass joint occurred in the central equiaxed fusion zone, whereas creep cavitation that originated in the second pass was blocked at the weld pass interface. The additional interface and strength variation between two passes in the dual-pass joint provides more restraint to creep deformation and crack propagation in the fusion zone, resulting in an increase in the creep rupture life of the dual-pass joint over the single-pass joint. Furthermore, the differences in content, morphology, and distribution of delta ferrite in the fusion zone of the joints favors more creep cavitation resistance in the dual-pass joint over the single-pass joint with the enhancement of creep rupture life.

  10. 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.

  11. An unusual case of cardiac tamponade: ruptured subaortic diverticulum.

    PubMed

    Salemi, Arash; Lee, Ben; Ivascu, Natalia; Webber, Geoffrey; Paul, Subroto

    2010-05-01

    Cardiac diverticula are rare congenital anomalies found as outpouchings from various chambers of the heart. We present a case of a diverticulum arising from the membranous septum with free rupture into the pericardial space and tamponade.

  12. Consequences of a tight squeeze: Nuclear envelope rupture and repair.

    PubMed

    Isermann, Philipp; Lammerding, Jan

    2017-03-13

    Cell migration through tight spaces can induce substantial deformations of the nucleus and cause nuclear envelope (NE) rupture, resulting in uncontrolled exchange of nuclear and cytosolic proteins. These events can cause DNA damage and, in severe cases, nuclear fragmentation, challenging the integrity of the genomic material. Cells overcome NE ruptures during interphase by repairing the NE using components of the endosomal sorting complexes required for transport (ESCRT) machinery. Paralleling the molecular mechanism employed during NE reformation in late mitosis, ESCRT-III subunits and the associated AAA-ATPase VPS4B are recruited to NE rupture sites and help restore NE integrity. While these findings are common to many cell types, they are particularly relevant in the context of cancer metastasis, where nuclear deformation and rupture could drive genomic instability in invading cells and further promote cancer progression. At the same time, inhibiting NE repair may offer new therapeutic approaches to specifically target invasive cancer cells.

  13. Uroperitoneum attributable to ruptured urachus in a yearling bull.

    PubMed

    Baxter, G M; Zamos, D T; Mueller, P O

    1992-02-15

    Ruptured urachus was found to result in uroperitoneum in a yearling Beefmaster bull. The uroperitoneum was initially believed to be attributable to ruptured bladder secondary to urolithiasis; however, catheter decompression of the bladder through an ischiatic urethrotomy did not resolve the uroperitoneum. The persistent urachus was diagnosed and removed through caudal right flank laparotomy with the bull standing. The urachus was attached to the umbilicus, communicated with the lumen of the bladder, and had a mucosal lining. Ruptured urachus is an unusual cause of uroperitoneum, but can cause clinical signs identical to those of ruptured bladder. Persistent urachus is a congenital abnormality in many species, but may be hereditary in Beefmaster cattle. In addition, the bull in this report developed hyperkalemia, which is considered an unusual finding in cattle with uroperitoneum.

  14. Cocaine Use and Splenic Rupture: A Rare Yet Serious Association

    PubMed Central

    Karthik, Nishrutha; Gnanapandithan, Karthik

    2016-01-01

    Cocaine abuse is frequent in patients visiting the emergency department. The knowledge of the cardiovascular complications of cocaine is excellent among physicians. However the awareness regarding its abdominal complications, the most important of which include gastroduodenal perforation, bowel ischemia and splenic rupture is less adequate. We report a 58-year-old with cocaine use who presents with upper abdominal pain and a rapidly worsening clinical status. He was found to have atraumatic splenic rupture causing a hemoperitoneum that was managed by intervention radiology guided splenic artery embolization. Splenic hemorrhage and rupture need timely recognition, as they are difficult to diagnose clinically and can be potentially fatal. In the encounter of patients with cocaine use who present with chest or upper abdominal pain, clinicians should consider imaging to look for splenic rupture as it is often masked or overlooked due to the complicated clinical picture. PMID:27777711

  15. Spontaneous rupture of thinning liquid films with Plateau borders

    NASA Astrophysics Data System (ADS)

    Anderson, Anthony; Brush, Lucien; Davis, Stephen

    2009-11-01

    Spontaneous film rupture from van der Waals instability is investigated in 2D. A thin liquid film between adjacent bubbles in a foam has finite length, curved boundaries (Plateau borders), and a drainage flow from capillary suction that causes thinning. A full linear stability analysis of this thinning film shows that rupture occurs once the film has thinned to tens of nanometers. Whereas, in an unbounded, quiescent, flat free film, rupture occurs when the thickness is hundreds of nanometers. Finite length, Plateau borders and flow are all found to contribute to the stabilization. The drainage flow leads to several distinct qualitative features as well. In particular, unstable disturbances are advected by the flow to the edges of the thin film. As a result, the edges of the film close to the Plateau borders are more susceptible to rupture that the center of the film.

  16. Multi-Canister overpack necessity of the rupture disk

    SciTech Connect

    SMITH, K.E.

    1998-11-03

    The Multi-Canister Overpack (MCO) rupture disk precludes the MCO from pressurization above the design limit during transport from the K Basins to the Cold Vacuum Drying (CVD) Facility and prior to connection of the CVD process piping. Removal of the rupture disk from the MCO design would: (a) result in unacceptable dose consequences in the event a thermal runaway accident occurred; (b) increase residual risk; and (c) remove a degree of specificity from the dose calculations. The potential cost savings of removing the rupture disk from the MCO design is offset by the cost of design modifications, changes to hazard analyses and safety analyses, and changes to existing documentation. Retaining the rupture disk mitigates the consequences of MCO overpressurization, and considering the overall economic impacts to the SNF Project, is the most cost effective approach.

  17. Plantar fascia rupture in a professional soccer player.

    PubMed

    Suzue, Naoto; Iwame, Toshiyuki; Kato, Kenji; Takao, Shoichiro; Tateishi, Tomohiko; Takeda, Yoshitsugu; Hamada, Daisuke; Goto, Tomohiro; Takata, Yoichiro; Matsuura, Tetsuya; Sairyo, Koichi

    2014-01-01

    We report the case of a 29-year-old male professional soccer player who presented with symptoms of plantar fasciitis. His symptoms occurred with no remarkable triggers and gradually worsened despite conservative treatments including taping, use of insoles, and physical therapy. Local corticosteroid injection was given twice as a further intervention, but his plantar fascia partially ruptured 49 days after the second injection. He was treated conservatively with platelet-rich plasma, and magnetic resonance imaging showed regenerative change of the ruptured fascia. Five months after the rupture, he returned to his original level of training. If professional athletes find it difficult to refrain from athletic activity, as in the present case, the risk of rupture due to corticosteroid injection should not be overlooked.

  18. [Subcapsular hematoma and rupture of the liver graft].

    PubMed

    Görög, Dénes; Fehérvári, Imre; Doros, Attila; Nemes, Balázs; Máthé, Zoltán; Kóbori, László; Járay, Jeno

    2008-08-01

    Subcapsular hematoma and/or rupture of the graft is uncommon but serious complication of liver transplantation. It may develop spontaneously or following parenchymal injuries or percutaneous transhepatic invasive procedures. This report describes three cases of subcapsular hematoma and/or rupture of the graft with different courses among 350 liver transplantations. In the first case, the patient died due to graft rupture caused by a pseudoaneurysm after biopsy. In the second case, a small injury of the donor liver resulted in a deep rupture, which required partial resection of the graft. The patient died in sepsis later. The third patient presented with a large subcapsular haematoma during transplantation, which was successfully treated. The authors' strategies developed intraoperatively for the management of hematomas. These involve opening and removing of the haematoma, haemostasis with Argon coagulation, which resulted in an adherent Glisson's capsule to the parenchyma and covering with collagen fleece coated with fibrinogen and thrombin.

  19. Outcome of ruptured uterus at University Teaching Hospital Aleppo, Syria.

    PubMed

    Bakour, S; Nassif, B; Nwosu, E C

    1998-09-01

    A 10-year review of ruptured gravid uterus at the University Teaching Hospital, Aleppo, Syria showed an incidence of one ruptured uterus in 565 deliveries. This is an average figure compared with published studies but is still high compared with developed countries. Sixty-four per cent of the cases of ruptured uterus had no antenatal care. It is no surprise therefore that maternal and fetal mortality was highest amongst the unbooked labouring women. In survivors the morbidity was also higher. Ruptured uterus is therefore a major cause of maternal and perinatal mortality and morbidity in Syria. The overall hospital maternal and perinatal mortalities for the period under review were 4.3% and 2.6% respectively. The main risk factor identified is scarring from previous caesarean sections. Other risk factors are discussed.

  20. Pancreatic rupture in four cats with high-rise syndrome.

    PubMed

    Liehmann, Lea M; Dörner, Judith; Hittmair, Katharina M; Schwendenwein, Ilse; Reifinger, Martin; Dupré, Gilles

    2012-02-01

    Pancreatic trauma and rupture are rare after feline high-rise syndrome; however, should it happen, pancreatic enzymes will leak into the abdominal cavity and may cause pancreatic autodigestion and fatty tissue saponification. If not diagnosed and treated, it can ultimately lead to multiorgan failure and death. In this case series, 700 records of high-rise syndrome cats that presented between April 2001 and May 2006 were analysed, and four cats with pancreatic rupture were identified. Clinical signs, diagnosis using ultrasonography and lipase activity in blood and abdominal effusion, and treatment modalities are reported. Three cats underwent surgical abdominal exploration, one cat was euthanased. Rupture of the left pancreatic limb was confirmed in all cases. Two of the operated cats survived to date. High-rise syndrome can lead to abdominal trauma, including pancreatic rupture. A prompt diagnosis and surgical treatment should be considered.

  1. Spontaneous Posterior Uterine Rupture in Twin-Twin Transfusion Syndrome

    PubMed Central

    Smid, Marcela C.; Waltner-Toews, Rebecca; Goodnight, William

    2015-01-01

    Background The maternal and fetal risks of uterine distension in rapidly progressive twin-twin transfusion syndrome (TTTS) in the setting of prior uterine scar are poorly characterized. Case We present the case of a 42-year-old woman, G4P1201, at 21 weeks gestation with stage-1 TTTS who developed a spontaneous posterior uterine rupture necessitating emergent laparotomy and delivery of previable fetuses, possibly due to prior uterine scar from a displaced intrauterine device. Conclusion TTTS may be a risk factor for uterine rupture, including uterine rupture in atypical anatomic locations. Prior unrecognized uterine scars, including perforations, may magnify the risk for atypical uterine rupture in the setting of excessive uterine distension. PMID:26929874

  2. A ruptured cerebral mycotic aneurysm caused by Abiotrophia defectiva endocarditis.

    PubMed

    Yang, Ya-Sung; Shang, Shih-Ta; Lin, Jung-Chung; Chiu, Chun-Hsiang; Chang, Feng-Yee

    2010-02-01

    We describe a case of ruptured cerebral mycotic aneurysm caused by Abiotrophia defectiva endocarditis in a previously healthy man. The patient underwent craniotomy with clipping of aneurysm and received antibiotic treatment for 6 weeks and survived.

  3. Flexibility and Muscular Strength.

    ERIC Educational Resources Information Center

    Liemohn, Wendell

    1988-01-01

    This definition of flexibility and muscular strength also explores their roles in overall physical fitness and focuses on how increased flexibility and muscular strength can help decrease or eliminate lower back pain. (CB)

  4. Dynamic rupture of megathrust earthquakes with branching on splay faults

    NASA Astrophysics Data System (ADS)

    Somala, S.; Ampuero, J. P.; Lapusta, N.

    2010-12-01

    The accretionary prism of subduction margins generally contains splay faults that approach the surface at steeper angles than the megathrust interface. Rupture propagating onto splay faults during megathrust earthquakes can increase seafloor uplift significantly and contribute to the potential of tsunami. Another key aspect of tsunamigenic earthquakes is their relatively low radiation efficiency, which could be related to slow rupture at shallow depth due to frictionally stable fault properties. We present here results of numerical simulations of dynamic rupture on megathrust/splay fault systems that address the mechanical plausibility and characteristics of coseismic slip on splay faults. As a case study, we consider a possible earthquake scenario for the Nankai subduction zone. Previous dynamic rupture simulations (Wendt et. al., 2009) considered a splay fault that cuts through the overriding crust and reaches the surface more than 100 km away from the trench. We examine instead a model geometry based on seismic reflection profiling in Nankai, in which a megasplay fault branches off at around 50 km from the trench, cuts through the sedimentary wedge and reaches the seafloor at about 25 km from the trench. We first investigate the 2D dynamics of this splay fault system, governed by slip-weakening friction law. We compare rupture propagation on this faulting model using a finite-element code (PyLith) and a spectral element code (SEM2DPACK). We report on the favorable conditions for splay faults to rupture, the degree of slip partitioning and the effects of arresting rupture at different depths on the plate-boundary. We also show how well our work correlates with previous works on branched fault systems. We then select a small set of 3D simulations that illustrates the main aspects. Finally the effect of velocity-strengthening fault properties at shallow depth is studied in the context of rate-and-state friction, with particular emphasis on the conditions to produce

  5. Complications of plantar fascia rupture associated with corticosteroid injection.

    PubMed

    Acevedo, J I; Beskin, J L

    1998-02-01

    From 1992 to 1995, 765 patients with a clinical diagnosis of plantar fasciitis were evaluated by one of the authors. Fifty-one patients were diagnosed with plantar fascia rupture, and 44 of these ruptures were associated with corticosteroid injection. The authors injected 122 of the 765 patients, resulting in 12 of the 44 plantar fascia ruptures. Subjective and objective evaluations were conducted through chart and radiographic review. Thirty-nine of these patients were evaluated at an average 27-month follow-up. Thirty patients (68%) reported a sudden onset of tearing at the heel, and 14 (32%) had a gradual onset of symptoms. In most cases the original heel pain was relieved by rupture. However, these patients subsequently developed new problems including longitudinal arch strain, lateral and dorsal midfoot strain, lateral plantar nerve dysfunction, stress fracture, hammertoe deformity, swelling, and/or antalgia. All patients exhibited diminished tension of the plantar fascia upon examination by the stretch test. Comparison of calcaneal pitch angles in the affected and uninvolved foot showed a statistically significant difference of 3.7 degrees (P = 0.0001). Treatment included NSAIDs, rest or cross-training, stretching, orthotics, and boot-brace immobilization. At an average 27-month follow-up, 50% had good/excellent scores and 50% had fair/poor scores. Recovery time was varied. Ten feet were asymptomatic by 6 months post rupture, four feet by 12 months post rupture, and 26 feet remained symptomatic 1 year post rupture. Our findings demonstrate that plantar fascia rupture after corticosteroid injection may result in long-term sequelae that are difficult to resolve.

  6. Multiple branching rupture of the 2009 Tonga-Samoa earthquake

    NASA Astrophysics Data System (ADS)

    Fan, Wenyuan; Shearer, Peter M.; Ji, Chen; Bassett, Dan

    2016-08-01

    Several source models have been proposed to explain the enigmatic 2009 Tonga-Samoa earthquake. The long-period data require a composite source model and can be fit with a normal-faulting subevent followed by one or more reverse-faulting subevents. The short-period data, in contrast, indicate a more compact rupture pattern around the epicenter. The lack of a unified source model reflects the complexity of the event. We analyze the spatiotemporal evolution of this earthquake with P wave back-projection from globally distributed stations in different frequency bands (low frequency: 0.05-0.2 Hz, high frequency: 0.2-2 Hz) and a multiple moment tensor inversion. The rupture propagation revealed by back-projection exhibits frequency-dependent behavior, with two branches of high-frequency-enriched bilateral rupture around the epicenter and a high-frequency-deficient rupture branch at the subduction interface. A composite source model with one Mw 8.0 normal-faulting earthquake east of the trench axis (seaward) followed by one Mw 8.1 reverse-faulting earthquake along the subduction interface west of the trench axis (landward) can explain the very long period data (200˜500 s). Combined with high-resolution swath bathymetry data, the back-projection images show that the azimuth of rupture branches east of the trench axis were controlled by the geometry of bending-related faults on the Pacific plate and that the rupture branch west of the trench axis may correlate with the along-strike fore-arc segmentation. The rupture along the subduction interface was triggered by the seaward rupture and a partially subducted normal fault may have played a key role in facilitating the triggering. The apparent normal-reverse faulting interactions pose a higher seismic risk to this region than their individual strands at the northernmost corner of the Tonga subduction zone.

  7. First report of splenic rupture following deep enteroscopy

    PubMed Central

    Girelli, Carlo Maria; Pometta, Roberta; Facciotto, Corinna; Mella, Roberto; Bernasconi, Giordano

    2016-01-01

    Splenic rupture is a rare complication of diagnostic and therapeutic gastrointestinal endoscopy procedures. Herein, we report for the first time a case of splenic rupture following therapeutic retrograde double-balloon enteroscopy, which occurred in an 85-year-old man who was treated for recurrent mid-intestinal bleeding that resulted from ileal angioectasia. This patient promptly underwent an operation and eventually recovered. PMID:27170840

  8. A Tuboovarian Abscess Associated with a Ruptured Spleen

    PubMed Central

    Li, Jennifer S.; Sheele, Johnathan Michael

    2016-01-01

    We report the first case of a tuboovarian abscess complicated by a ruptured spleen. Our patient was a 27-year-old female with human immunodeficiency virus (HIV) who presented to the emergency department (ED) with complaints of urinary symptoms and diarrhea. After being diagnosed with a tuboovarian abscess (TOA), she received antibiotics and was admitted to the gynecology service. Shortly thereafter she developed hemorrhagic shock, necessitating a splenectomy and salpingooophorectomy from a ruptured spleen. PMID:26904315

  9. Rupture of benign thyroid tumors after radio-frequency ablation.

    PubMed

    Shin, J H; Jung, S L; Baek, J H; Kim, J-H

    2011-12-01

    Rupture of benign thyroid tumors after RFA is very rare. We experienced 6 cases in 4 institutions. All patients presented with abrupt neck swelling and pain between 9 and 60 days after RFA. Imaging and clinical findings of the ruptured tumors were anterior subcapsular location, mixed composition, large size, and repeated ablations. Conservative treatment was sufficient in 3 cases, whereas surgical management was required in 3.

  10. Rupture of the stomach following mouth-to-mouth respiration

    PubMed Central

    Solowiejczyk, M.; Wapnick, S.; Koren, E.; Mandelbaum, J.

    1974-01-01

    Successful repair and survival after rupture of the stomach in a patient who received mouth-to-mouth respiration is presented. We were able to find only one report in the literature where rupture of the stomach occurred following this manoeuvre—the patient did not survive. The possible aetiological factors and measures designed to avoid this complication are discussed. ImagesFig. 1 PMID:4469046

  11. Dose response of selected solid state detectors in applied homogeneous transverse and longitudinal magnetic fields

    SciTech Connect

    Reynolds, M.; Fallone, B. G.; Rathee, S.

    2014-09-15

    Purpose: MR-Linac devices under development worldwide will require standard calibration, commissioning, and quality assurance. Solid state radiation detectors are often used for dose profiles and percent depth dose measurements. The dose response of selected solid state detectors is therefore evaluated in varying transverse and longitudinal magnetic fields for this purpose. Methods: The Monte Carlo code PENELOPE was used to model irradiation of a PTW 60003 diamond detector and IBA PFD diode detector in the presence of a magnetic field. The field itself was varied in strength, and oriented both transversely and longitudinally with respect to the incident photon beam. The long axis of the detectors was oriented either parallel or perpendicular to the photon beam. The dose to the active volume of each detector in air was scored, and its ratio to dose with zero magnetic field strength was determined as the “dose response” in magnetic field. Measurements at low fields for both detectors in transverse magnetic fields were taken to evaluate the accuracy of the simulations. Additional simulations were performed in a water phantom to obtain few representative points for beam profile and percent depth dose measurements. Results: Simulations show significant dose response as a function of magnetic field in transverse field geometries. This response can be near 20% at 1.5 T, and it is highly dependent on the detectors’ relative orientation to the magnetic field, the energy of the photon beam, and detector composition. Measurements at low transverse magnetic fields verify the simulations for both detectors in their relative orientations to radiation beam. Longitudinal magnetic fields, in contrast, show little dose response, rising slowly with magnetic field, and reaching 0.5%–1% at 1.5 T regardless of detector orientation. Water tank and in air simulation results were the same within simulation uncertainty where lateral electronic equilibrium is present and expectedly

  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

    An extensive data set of teleseismic and strong-motion waveforms and geodetic offsets is used to study the rupture history of the 2008 Wenchuan, China, 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. Sex Education as a Transversal Subject

    ERIC Educational Resources Information Center

    Rabelo, Amanda Oliveira; Pereira, Graziela Raupp; Reis, Maria Amélia; Ferreira, António G.

    2015-01-01

    Currently, sex education is in many countries a transversal subject, in which the school becomes a privileged place for the implementation of policies that aim at promoting "public health." Its design as a cross-cutting subject envisages fostering the dissemination of these subjects in all pedagogical and curricular fields; however, we…

  14. The Effects of Transverse Stress on Magnetization.

    DTIC Science & Technology

    1982-01-01

    move to oppose the field in tension (90-). The contributions of these two types of walls are reversed with the aplication of co.npression((90-) walls...stress and field, whereas this research investigates transverse stress and field. An examination of the thermodynamics involved in the two cases quickly

  15. Measuring transverse shape with virtual photons

    SciTech Connect

    Hoyer, Paul; Kurki, Samu

    2011-06-01

    A two-dimensional Fourier transform of hadron form factors allows to determine their charge density in transverse space. We show that this method can be applied to any virtual photon induced transition, such as {gamma}{sup *}(q)+N{yields}{pi}N. Only Fock states that are common to the initial and final states contribute to the amplitudes, which are determined by the overlap of the corresponding light-front wave functions. Their transverse extent may be studied as a function of the final state configuration, allowing qualitatively new insight into strong interaction dynamics. Fourier transforming the cross section (rather than the amplitude) gives the distribution of the transverse distance between the virtual photon interaction vertices in the scattering amplitude and its complex conjugate. While the measurement of parton distributions in longitudinal momentum depends on the leading twist approximation (-q{sup 2}{yields}{infinity} limit), all q{sup 2}<0 values contribute to the Fourier transform, with the transverse resolution increasing with the available range in q{sup 2}. We illustrate the method using QED amplitudes.

  16. Transverse stability in a Stark decelerator

    SciTech Connect

    Meerakker, Sebastiaan Y. T. van de; Bethlem, Hendrick L.; Vanhaecke, Nicolas; Meijer, Gerard

    2006-02-15

    The concept of phase stability in a Stark decelerator ensures that polar molecules can be accelerated, guided, or decelerated without loss; molecules within a certain position and velocity interval are kept together throughout the deceleration process. In this paper the influence of the transverse motion on phase stability in a Stark decelerator is investigated. For typical deceleration experiments--i.e., for high values of the phase angle {phi}{sub 0}--the transverse motion considerably enhances the region in phase space for which phase stable deceleration occurs. For low values of {phi}{sub 0}, however, the transverse motion reduces the acceptance of a Stark decelerator and unstable regions in phase space appear. These effects are quantitatively explained in terms of a coupling between the longitudinal and transverse motion. The predicted longitudinal acceptance of a Stark decelerator is verified by measurements on a beam of OH (X {sup 2}{pi}{sub 3/2},J=3/2) radicals passing through a Stark decelerator.

  17. The transverse field Richtmyer-Meshkov instability in magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Wheatley, V.; Samtaney, R.; Pullin, D. I.; Gehre, R. M.

    2014-01-01

    The magnetohydrodynamic Richtmyer-Meshkov instability is investigated for the case where the initial magnetic field is unperturbed and aligned with the mean interface location. For this initial condition, the magnetic field lines penetrate the perturbed density interface, forbidding a tangential velocity jump and therefore the presence of a vortex sheet. Through simulation, we find that the vorticity distribution present on the interface immediately after the shock acceleration breaks up into waves traveling parallel and anti-parallel to the magnetic field, which transport the vorticity. The interference of these waves as they propagate causes the perturbation amplitude of the interface to oscillate in time. This interface behavior is accurately predicted over a broad range of parameters by an incompressible linearized model derived presently by solving the corresponding impulse driven, linearized initial value problem. Our use of an equilibrium initial condition results in interface motion produced solely by the impulsive acceleration. Nonlinear compressible simulations are used to investigate the behavior of the transverse field magnetohydrodynamic Richtmyer-Meshkov instability, and the performance of the incompressible model, over a range of shock strengths, magnetic field strengths, perturbation amplitudes and Atwood numbers.

  18. Bending of Beams Subjected to Transverse Impacts,

    DTIC Science & Technology

    1983-04-01

    and rotary inertia effects have been considered by Karunes and Onat [6] Symonds [7] and Jones and Gomes de Oliveira (8]. The main aspects of the...Phys. Sol., Vol. 2, 1954, pp. 92-102. 6. Karunes , B. and Onat, E.T., "On the Effect of Shear on Plastic Deformation of Beams Under Transverse Impact

  19. Barium granuloma of the transverse colon.

    PubMed Central

    McKee, P. H.; Cameron, C. H.

    1978-01-01

    A case of barium sulphate granuloma of the transverse colon following gunshot wounds to the abdomen has been described. Scanning electron microscopy with electron probe microanalysis was used to confirm the presence of barium sulphate and the absence of lead or other elements related to the gunshot wounds. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:740599

  20. Variation of transverse momentum in hadronic collisions

    NASA Technical Reports Server (NTRS)

    Saint Amand, J.; Uritam, R. A.

    1975-01-01

    The paper presents a detailed parameterization of the transverse momentum in hadronic collisions on multiplicity and on beam momentum. Hadronic collisions are considered at energies below the ultra-high energy domain, on the basis of an uncertainty relation and a naive eikonal model with an impact-parameter-dependent multiplicity.

  1. Formulas for Precise Transverse Mercator Projection

    NASA Technical Reports Server (NTRS)

    Wallis, D. E.

    1983-01-01

    Transverse mercator projection, surface of Earth or other spheroid is mapped onto cylinder tangent at meridian of longitude. New method performs mapping by means of mathematical series in which higher order terms correct for deviation from exact sphericity. New method yields precise geodetic maps.

  2. Perfusion computed tomography imaging of abdominal aortic aneurysms may be of value for patient specific rupture risk estimation.

    PubMed

    Kontopodis, Nikolaos; Galanakis, Nikolaos; Tsetis, Dimitrios; Ioannou, Christos V

    2017-04-01

    Abdominal aortic aneurysm (AAA) continues to pose a significant cause of unexpected mortality in the developed countries with its incidence constantly rising. The indication of elective surgical repair is currently based on the maximum diameter and growth rate criteria which represent an oversimplification of the Law of Laplace stating that the stress exerted in a cylinder or sphere is proportional to its radius. These criteria fail to capture the complex pathophysiology of the aneurismal disease thus often leading to therapeutic inaccuracies (treating large AAAs with a very low actual rupture risk while observing smaller ones with a much greater risk). Aneurysmal disease is mainly a degenerative process leading to loss of structural integrity of the diseased aortic wall which cannot withhold the stresses due to systemic pressurization. Moreover aortic wall degeneration has been shown to be a localized phenomenon and rupture depends on the pointwise comparison of strength and stress rather than a global aortic wall weakening. Ex-vivo mechanical studies have related vessel wall hypoxia to loss of structural endurance and reduced wall strength. Therefore a module to capture in vivo variation of aortic wall blood supply and oxygenation would be of value for the evaluation of AAA rupture risk. Perfusion computed tomography (PCT) imaging represents a novel technique which has been already used to estimate tissue vascularity in several clinical conditions but not aneurismal disease. We hypothesize that PCT could be used as an adjunct tool during AAA diagnostics in order to evaluate aortic wall oxygenation in vivo, therefore providing a possible means to identify weak spots making the lesion amenable to rupture.

  3. 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.

  4. Dynamic rupture modeling with laboratory-derived constitutive relations

    USGS Publications Warehouse

    Okubo, P.G.

    1989-01-01

    A laboratory-derived state variable friction constitutive relation is used in the numerical simulation of the dynamic growth of an in-plane or mode II shear crack. According to this formulation, originally presented by J.H. Dieterich, frictional resistance varies with the logarithm of the slip rate and with the logarithm of the frictional state variable as identified by A.L. Ruina. Under conditions of steady sliding, the state variable is proportional to (slip rate)-1. Following suddenly introduced increases in slip rate, the rate and state dependencies combine to produce behavior which resembles slip weakening. When rupture nucleation is artificially forced at fixed rupture velocity, rupture models calculated with the state variable friction in a uniformly distributed initial stress field closely resemble earlier rupture models calculated with a slip weakening fault constitutive relation. Model calculations suggest that dynamic rupture following a state variable friction relation is similar to that following a simpler fault slip weakening law. However, when modeling the full cycle of fault motions, rate-dependent frictional responses included in the state variable formulation are important at low slip rates associated with rupture nucleation. -from Author

  5. Stochastic Earthquake Rupture Modeling Using Nonparametric Co-Regionalization

    NASA Astrophysics Data System (ADS)

    Lee, Kyungbook; Song, Seok Goo

    2016-10-01

    Accurate predictions of the intensity and variability of ground motions are essential in simulation-based seismic hazard assessment. Advanced simulation-based ground motion prediction methods have been proposed to complement the empirical approach, which suffers from the lack of observed ground motion data, especially in the near-source region for large events. It is important to quantify the variability of the earthquake rupture process for future events and to produce a number of rupture scenario models to capture the variability in simulation-based ground motion predictions. In this study, we improved the previously developed stochastic earthquake rupture modeling method by applying the nonparametric co-regionalization, which was proposed in geostatistics, to the correlation models estimated from dynamically derived earthquake rupture models. The nonparametric approach adopted in this study is computationally efficient and, therefore, enables us to simulate numerous rupture scenarios, including large events (M > 7.0). It also gives us an opportunity to check the shape of true input correlation models in stochastic modeling after being deformed for permissibility. We expect that this type of modeling will improve our ability to simulate a wide range of rupture scenario models and thereby predict ground motions and perform seismic hazard assessment more accurately.

  6. A Kinematic Rupture Model Generator Using Irikura's Recipe

    SciTech Connect

    Pitarka, A.

    2016-04-01

    In this project we developed GEN_SRF4 a computer program for generating kinematic rupture models, compatible with the SRF format, using Irikura and Miyake (2011) asperity-­based earthquake rupture model (IM2011, hereafter). IM2011, also known as Irkura’s recipe, has been widely used to model and simulate ground motion from earthquakes in Japan. An essential part of the method is its kinematic rupture generation technique, which is based on a deterministic rupture asperity modeling approach. The source model simplicity and efficiency of IM2011 at reproducing ground motion from earthquakes recorded in Japan makes it attractive to developers and users of the Southern California Earthquake Center Broadband Platform (SCEC BB platform). Besides writing the code the objective of our study was to test the transportability of IM2011 to broadband simulation methods used by the SCEC BB platform. Here we test it using the Graves and Pitarka (2010) method, implemented in the platform. We performed broadband (0.1--10 Hz) ground motion simulations for a M6.7 scenario earthquake using rupture models produced with both GEN_SRF4 and rupture generator of Graves and Pitarka (2016), (GP2016 hereafter). In the simulations we used the same Green’s functions, and same high frequency approach for calculating the low-­frequency and high-­frequency parts of ground motion, respectively.

  7. Fast rupture propagation for large strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, Dun; Mori, Jim; Koketsu, Kazuki

    2016-04-01

    Studying rupture speeds of shallow earthquakes is of broad interest because it has a large effect on the strong near-field shaking that causes damage during earthquakes, and it is an important parameter that reflects stress levels and energy on a slipping fault. However, resolving rupture speed is difficult in standard waveform inversion methods due to limited near-field observations and the tradeoff between rupture speed and fault size for teleseismic observations. Here we applied back-projection methods to estimate the rupture speeds of 15 Mw ≥ 7.8 dip-slip and 8 Mw ≥ 7.5 strike-slip earthquakes for which direct P waves are well recorded in Japan on Hi-net, or in North America on USArray. We found that all strike-slip events had very fast average rupture speeds of 3.0-5.0 km/s, which are near or greater than the local shear wave velocity (supershear). These values are faster than for thrust and normal faulting earthquakes that generally rupture with speeds of 1.0-3.0 km/s.

  8. 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…

  9. 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

  10. Location of largest earthquake slip and fast rupture controlled by along-strike change in fault structural maturity due to fault growth

    NASA Astrophysics Data System (ADS)

    Perrin, Clément; Manighetti, Isabelle; Ampuero, Jean-Paul; Cappa, Frédéric; Gaudemer, Yves

    2016-05-01

    Earthquake slip distributions are asymmetric along strike, but the reasons for the asymmetry are unknown. We address this question by establishing empirical relations between earthquake slip profiles and fault properties. We analyze the slip distributions of 27 large continental earthquakes in the context of available information on their causative faults, in particular on the directions of their long-term lengthening. We find that the largest slips during each earthquake systematically occurred on that half of the ruptured fault sections most distant from the long-term fault propagating tips, i.e., on the most mature half of the broken fault sections. Meanwhile, slip decreased linearly over most of the rupture length in the direction of long-term fault propagation, i.e., of decreasing structural maturity along strike. We suggest that this earthquake slip asymmetry is governed by along-strike changes in fault properties, including fault zone compliance and fault strength, induced by the evolution of off-fault damage, fault segmentation, and fault planarity with increasing structural maturity. We also find higher rupture speeds in more mature rupture sections, consistent with predicted effects of low-velocity damage zones on rupture dynamics. Since the direction(s) of long-term fault propagation can be determined from geological evidence, it might be possible to anticipate in which direction earthquake slip, once nucleated, may increase, accelerate, and possibly lead to a large earthquake. Our results could thus contribute to earthquake hazard assessment and Earthquake Early Warning.

  11. Fetal immune response following prematurely ruptured membranes.

    PubMed

    Cederqvist, L L; Francis, L C; Zervoudakis, I A; Becker, C G; Litwin, S D

    1976-10-01

    Concentrations of immunoglobulins (Ig)A1, and IgA2, IgD, IgE, IgG, and IgM have been determined in cord blood, amniotic fluid, and maternal serum in a group of patients with a history of prematurely ruptured membranes (PRM) prior to the onset of labor and in a control group of patients undergoing normal delivery and without a history of infection during pregnancy. IgA and IgD were determined by sensitive hemagglutination-inhibition tests; IgG and IgM, by radial immunodiffusion; IgE, by a radioimmunoassay. There was evidence for an immune response in 10 of 16 cases of PRM: five of 16 had increased IgA but normal IgM; three of 16 had increased IgA and IgM; two of 16 had high IgM and normal IgA in cord blood. In patients with significantly increased levels of either IgA or IgM or both, there was a decreased level of IgD. These changes are most likely the result of the immune response to ascending infection from the maternal genitals. The sensitive testing method employed could demonstrate the presence of IgD in 53 per cent of normal cord blood samples and 72 per cent of amniotic fluid samples obtained at term. IgE was found in all normal cord blood and amniotic fluid samples tested. By concentrating the amniotic fluid up to 180-fold, IgM was demonstrated in all normal samples tested. The potential importance of IgA determinations in cord blood in addition to IgM determination for detection of intrauterine infections is stressed.

  12. Management of infected carotid artery rupture.

    PubMed

    Liu, Jie; Zeng, Quan; Huang, Jiang-Ju; Hu, Guo-Hua

    2014-06-01

    Carotid artery rupture (CAR) is a life-threatening complication of head and neck cancer, and infection complicates its management. The purpose of this study was to review our experience with the treatment of infected CAR and to summarize the existing literature on this topic. We retrospectively reviewed the medical records of patients treated in our department from 2000 to 2011 and re-analyzed cases reported in the literature during the same time period. We analyzed etiology, anatomic location, treatment, and rates of recurrent hemorrhage for each case. A total of 46 episodes of infected CAR occurred in the four patients in our own records and 27 patients described in the literature. Twenty-eight patients suffered from various head and neck cancers and underwent surgical resection, and 27 of them subsequently received radiotherapy or radiotherapy combined with chemotherapy (the 28th patient died before radiotherapy due to severe blood loss). The most common site of bleeding was the common carotid artery (33/46, 71.7%). Seventeen cases (17/45, 37.8%) were treated with surgical ligation, 20 (44.4%) with stent placement, and 7 (15.6%) with embolization. Surgical ligation had a lower rate of recurrent bleeding (2/17, 11.8%) than stent placement (12/20, 60.0%) when used for the treatment of infected CAR (P = 0.037, Chi squared test). Our results suggest that surgical ligation is an effective option in the management of infected CAR and may be the best choice to prevent recurrent hemorrhage. The complication rates, however, may be high when the common carotid or the internal carotid arteries are ligated.

  13. Behavior Of A Confined Tension Lap Splice In High-Strength Reinforced Concrete Beams

    NASA Astrophysics Data System (ADS)

    Abdel-Kareem, Ahmed H.; Abousafa, Hala; El-Hadidi, Omaia S.

    2015-09-01

    The results of an experimental program conducted on seventeen simply supported concrete beams to study the effect of transverse reinforcement on the behavior of the lap splice of a steel reinforcement in tension zones in high-strength concrete beams are presented. The parameters included in the experimental program were the concrete compressive strength, the lap splice length, the amount of transverse reinforcement provided within the splice region, and the shape of the transverse reinforcement around the spliced bars. The experimental results showed that the displacement ductility increased and the mode of failure changed from a splitting bond failure to a flexural failure when the amount of the transverse reinforcement in the splice region increased, and the compressive strength increased up to 100 MPa. The presence of the transverse reinforcement around the spliced bars had a pronounced effect on increasing the ultimate load, the ultimate deflection, and the displacement ductility. The prediction of maximum steel stresses for spliced bars using the ACI 318-05 building code was compared with the experimental results. The comparison showed that the effect of the transverse reinforcement around spliced bars has to be considered into the design equations for lap splice length in high-strength concrete beams.

  14. [Report on 21 uterine ruptures and the influence of single row uterotomy stitching on rupture prevention (author's transl)].

    PubMed

    Kleissl, H P; Becker, H; Falkert

    1975-07-01

    Wound closure by 1 row of interupted sutures provides optimal healing conditions. As a result scar tissue formation is cut down. This general surgical principle is valid in stitching an uterotomy as well. Increasing frequency of cesarian section could end up in a rising number of scar ruptures. This drawback for a subsequent pregnancy should be met by the single row technique. It was applied in 1434 women from 1962 to 1974. All of them had lower segment cesarian sections. Only 3 harmless ruptures occurred in this group. The clinical course of 12 scar ruptures after terraced uterotomy closure was less favourable. In 6 cases a pregnant uterus ruptured without previous operation. Clinical results are compared. This backs the technique practised. In 5 patients the ruptured uterus could be repaired in the same way as in cesarian section. Hysterectomy, however, was the usual treatment. The risk of rupture after classical cesarian section is lowered by the technique described. This applies to the surgical treatment of uterus duplex as well.

  15. 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

  16. 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.

  17. Repetitive operation of switchless transverse flow transversely excited atmosphere CO2 lasers.

    PubMed

    Patil, Gautam C; Nilaya, J Padma; Biswas, D J

    2011-09-01

    The enhanced preionisation efficiency of a mutually coupled parallel spark preioniser has been exploited to achieve switchless operation of a transversely excited atmosphere (TEA) CO(2) laser in the conventional transverse gas flow configuration. This made the laser more compatible to repetitive operation and the satisfactory performance of a switchless TEA CO(2) laser of ~8 cc active volume is reported here up to a maximum repetition rate of 100 Hz at a gas replenishment factor of ~2.

  18. 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

  19. 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.

  20. Dynamic rupture in a damage-breakage rheology model

    NASA Astrophysics Data System (ADS)

    Lyakhovsky, Vladimir; Ben-Zion, Yehuda; Ilchev, Assen; Mendecki, Aleksander

    2016-08-01

    We present a thermodynamically based formulation for modelling dynamic rupture processes in the brittle crust using a continuum damage-breakage rheology. The model combines aspects of a continuum viscoelastic damage framework for brittle solids with a continuum breakage mechanics for granular flow within dynamically generated slip zones. The formulation accounts for the density of distributed cracking and other internal flaws in damaged rocks with a scalar damage parameter, and addresses the grain size distribution of a granular phase in the slip zone with a breakage parameter. A dynamic brittle instability is associated with a critical level of damage in the solid, leading to loss of convexity of the solid strain energy, localization and transition to a granular phase associated with lower energy level. The continuum damage-breakage rheology model treats the localization to a slip zone at the onset of dynamic rupture and post-failure recovery process as phase transitions between solid and granular states. The model generates sub- and supershear rupture velocities and pulse-type ruptures seen also in frictional models, and additional important features such as strong dynamic changes of volumetric strain near the rupture front and diversity of nucleation mechanisms. The propagation of rupture front and slip accumulation at a point are correlated with sharp dynamic dilation followed by a gradual decay to a level associated with the final volumetric change associated with the granular phase transition in the slipping zone. The local brittle failure process associated with the solid-granular transition is expected to produce isotropic radiation in addition to the deviatoric terms. The framework significantly extends the ability to model brittle processes in complex geometrical structures and allows analysing the roles of gouge thickness and other parameters on nucleation, rupture and radiation characteristics.

  1. Downdip landward limit of Cascadia great earthquake rupture

    NASA Astrophysics Data System (ADS)

    Hyndman, R. D.

    2013-10-01

    paper examines the constraints to the downdip landward limit of rupture for the Cascadia great earthquakes off western North America. This limit is a primary control for ground motion hazard at near-coastal cities. The studies also provide information on the physical controls of subduction thrust rupture globally. The constraints are (1) "locked/transition" zones from geodetic deformation (GPS, repeated leveling, tide gauges); (2) rupture zone from paleoseismic coastal marsh subsidence, "paleogeodesy"; (3) temperature on the thrust for the seismic-aseismic transition; (4) change in thrust seismic reflection character downdip from thin seismic to thick ductile; (5) fore-arc mantle corner aseismic serpentinite and talc overlying the thrust; (6) updip limit of episodic tremor and slip (ETS) slow slip; (7) rupture area associations with shelf-slope basins; (8) depth limit for small events on the thrust; and (9) landward limit of earthquakes on the Nootka transform fault zone. The most reliable constraints for the limit of large rupture displacement, >10 m, are generally just offshore in agreement with thermal control for this hot subduction zone, but well-offshore central Oregon and near the coast of northern Washington. The limit for 1-2 m rupture that can still provide strong shaking is less well estimated 25-50 km farther landward. The fore-arc mantle corner and the updip extent of ETS slow slip are significantly landward from the other constraints. Surprisingly, there is a downdip gap between the best other estimates for the great earthquake rupture zone and the ETS slow slip. In this gap, plate convergence may occur as continuous slow creep.

  2. 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.

  3. 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.

  4. Predictive biomechanical analysis of ascending aortic aneurysm rupture potential

    PubMed Central

    Martin, Caitlin; Sun, Wei; Pham, Thuy; Elefteriades, John

    2013-01-01

    Aortic aneurysm is a leading cause of death in adults, often taking lives without any premonitory signs or symptoms. Adverse clinical outcomes of aortic aneurysm are preventable by elective surgical repair; however, identifying at-risk individuals is difficult. The objective of this study was to perform a predictive biomechanical analysis of ascending aortic aneurysm (AsAA) tissue to assess rupture risk on a patient-specific level. AsAA tissues, obtained intra-operatively from 50 patients, were subjected to biaxial mechanical and uniaxial failure tests to obtain their passive elastic mechanical properties. A novel analytical method was developed to predict the AsAA pressure-diameter response as well as the aortic wall yield and failure responses. Our results indicated that the mean predicted AsAA diameter at rupture was 5.6 ± 0.7 cm, and the associated blood pressure to induce rupture was 579.4 ± 214.8 mmHg. Statistical analysis showed significant positive correlation between aneurysm tissue compliance and predicted risk of rupture, where patients with a pressure-strain modulus ≥100 kPa may be nearly twice as likely to experience rupture than patients with more compliant aortic tissue. The mechanical analysis of pre-dissection patient tissue properties established in this study could predict the “future” onset of yielding and rupture in AsAA patients. The analysis results implicate decreased tissue compliance as a risk factor for AsAA rupture. The presented methods may serve as a basis for the development of a pre-operative planning tool for AsAA evaluation, a tool currently unavailable. PMID:23948500

  5. 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.

  6. Nucleation of slip-weakening rupture instability in landslides by localized increase of pore pressure

    NASA Astrophysics Data System (ADS)

    Viesca, Robert C.; Rice, James R.

    2012-03-01

    We model landslide initiation as slip surface growth driven by locally elevated pore pressure, with particular reference to submarine slides. Assuming an elastic medium and friction that weakens with slip, solutions exist in which the slip surface may dynamically grow, without further pore pressure increases, at a rate of the order of the sediment shear wave speed, a situation comparable to earthquake nucleation. The size of the rupture at this transition point depends weakly on the imposed pore pressure profile; however, the amount of slip at the transition depends strongly on whether the pore pressure was broadly or sharply elevated. Sharper profiles may result in pore pressures reaching the total slope-normal stress before dynamic rupture is nucleated. While we do not account for modes of failure other than pure slip on a failure surface, this may be an indication that additional modes involving liquefaction or hydraulic cracking may be factors in the initiation of shallow slope failure. We identify two length scales, one geometrical (h, depth below the free surface) and one material (ℓ, determined by the frictional weakening rate) and a transition in nucleation behavior between effectively "deep" and "shallow" limits dependent on their ratio. Whether dynamic propagation of failure is indefinite or arresting depends largely on whether the background shear stress is closer to nominal peak or residual frictional strength. This is determined in part by background pore pressures, and to consider the submarine case we simplify a common sedimentation/consolidation approach to reflect interest in near-seafloor conditions.

  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. Relation of Engine Turbine-blade Life to Stress-rupture Properties of the Alloys, Stellite 21, Hastelloy B, Cast S-816, Forged S-816, X-40, Nimonic 80, Refractaloy 26, N-155, and Inconel X

    NASA Technical Reports Server (NTRS)

    Garrett, F B; Yaker, C

    1951-01-01

    An investigation was conducted to relate the engine performance of the heat-resistant alloys, Stellite 21, Hastelloy B, cast S-816, forged S-816, X-40, Nimonic 80, Refractory 26, N-155, and Iconel X to their stress-rupture properties. The engine test consisted of the repetition of a 20-minute cycle, 15 minutes at rated speed and approximately 5 minutes at idle. The results of the investigation indicated a direct correlation between stress-rupture life and blade life for the relatively low-strength alloys. The stress-rupture life and blade life for the relatively high-strength alloys did not correlate because of the effects of the vibratory stresses and the corrosive-gas atmosphere.

  9. Transversal Clifford gates on folded surface codes

    SciTech Connect

    Moussa, Jonathan E.

    2016-10-12

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surface codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. Lastly, the specific application of these codes to universal quantum computation based on qubit fusion is also discussed.

  10. Transversal Clifford gates on folded surface codes

    DOE PAGES

    Moussa, Jonathan E.

    2016-10-12

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surfacemore » codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. Lastly, the specific application of these codes to universal quantum computation based on qubit fusion is also discussed.« less

  11. Quantum interference between transverse spatial waveguide modes

    PubMed Central

    Mohanty, Aseema; Zhang, Mian; Dutt, Avik; Ramelow, Sven; Nussenzveig, Paulo; Lipson, Michal

    2017-01-01

    Integrated quantum optics has the potential to markedly reduce the footprint and resource requirements of quantum information processing systems, but its practical implementation demands broader utilization of the available degrees of freedom within the optical field. To date, integrated photonic quantum systems have primarily relied on path encoding. However, in the classical regime, the transverse spatial modes of a multi-mode waveguide have been easily manipulated using the waveguide geometry to densely encode information. Here, we demonstrate quantum interference between the transverse spatial modes within a single multi-mode waveguide using quantum circuit-building blocks. This work shows that spatial modes can be controlled to an unprecedented level and have the potential to enable practical and robust quantum information processing. PMID:28106036

  12. Optimization of energy extraction in transverse galloping

    NASA Astrophysics Data System (ADS)

    Sorribes-Palmer, F.; Sanz-Andres, A.

    2013-11-01

    A numerical method to analyse the stability of transverse galloping based on experimental measurements, as an alternative method to polynomial fitting of the transverse force coefficient Cz, is proposed in this paper. The Glauert-Den Hartog criterion is used to determine the region of angles of attack (pitch angles) prone to present galloping. An analytic solution (based on a polynomial curve of Cz) is used to validate the method and to evaluate the discretization errors. Several bodies (of biconvex, D-shape and rhomboidal cross sections) have been tested in a wind tunnel and the stability of the galloping region has been analysed with the new method. An algorithm to determine the pitch angle of the body that allows the maximum value of the kinetic energy of the flow to be extracted is presented.

  13. Transverse Instabilities in the Fermilab Recycler

    SciTech Connect

    Prost, L.R.; Burov, A.; Shemyakin, A.; Bhat, C.M.; Crisp, J.; Eddy, N.; /Fermilab

    2011-07-01

    Transverse instabilities of the antiproton beam have been observed in the Recycler ring soon after its commissioning. After installation of transverse dampers, the threshold for the instability limit increased significantly but the instability is still found to limit the brightness of the antiprotons extracted from the Recycler for Tevatron shots. In this paper, we describe observations of the instabilities during the extraction process as well as during dedicated studies. The measured instability threshold phase density agrees with the prediction of the rigid beam model within a factor of 2. Also, we conclude that the instability threshold can be significantly lowered for a bunch contained in a narrow and shallow potential well due to effective exclusion of the longitudinal tails from Landau damping.

  14. Transverse mode imaging of guided matter waves

    SciTech Connect

    Dall, R. G.; Hodgman, S. S.; Johnsson, M. T.; Baldwin, K. G. H.; Truscott, A. G.

    2010-01-15

    Ultracold atoms whose de Broglie wavelength is of the same order as an extended confining potential can experience waveguiding along the potential. When the transverse kinetic energy of the atoms is sufficiently low, they can be guided in the lowest order mode of the confining potential by analogy with light guided by a single mode optical fiber. We have obtained the first images of the transverse mode structure of guided matter waves in a confining potential with up to 65% of atoms in the lowest order mode. The coherence of the guided atomic de Broglie waves is demonstrated by the diffraction pattern produced when incident upon a two dimensional periodic structure. Such coherent waveguides will be important atom optic components in devices with applications such as atom holography and atom interferometry.

  15. Transverse tectonic boundaries near Kodiak Island, Alaska.

    USGS Publications Warehouse

    Fisher, M.A.; Bruns, T.R.; Von Huene, R.

    1981-01-01

    Transverse tectonic boundaries exist at the NE and SW ends of the Kodiak islands, so that the Aleutian arc-trench system is longitudinally segmented in this area. Evidence for the transverse boundaries includes alignments of such geologic features as offset volcanic lineations, terminations of structural trends, and boundaries of discrete zones of earthquake aftershock sequences. The boundaries appear to be broad zones of disruption that began to form during the late Miocene or Pliocene. Although oceanic fracture zones and seamount chains intersect the continental margin near the boundaries, subduction of these features probably did not cause the tectonic boundaries. The fracture zones and seamount chains have swept northeastward along the margin, at least since the late Pliocene, because of the direction of convergence of the Pacific and N American plates. -Authors

  16. Transverse mis-alignments in a driver

    SciTech Connect

    Smith, L.; Hahn, K.

    1988-06-01

    The transverse errors of the beam lines are usually corrected by an appropriate feed back to bring the beam back on axis. In an induction linac, however, the head and tail of the bunch differ substantially in momentum at a given lens location. As a result, the correction has to be time dependent. Such a correction becomes increasingly difficult as the beam energy increases and the time duration of the bunch decreases. As a step towards an understanding of the problem, we have analyzed the extreme case of applying no correction. Since the lattice configuration changes and the transverse oscillations are damped as the ions are accelerated, the rms amplitude does not increase simply as the square root of the number of periods, as one would expect for constant velocity in a uniform channel. 2 refs., 2 figs.

  17. MEASUREMENT OF TRANSVERSE ECHOES IN RHIC.

    SciTech Connect

    FISCHER, W.; SATOGATA, T.; TOMAS. R.

    2005-05-16

    Beam echoes are a very sensitive method to measure diffusion, and longitudinal echo measurements were performed in a number of machines. In RHIC, for the first time, a transverse beam echo was observed after applying a dipole kick followed by a quadrupole .kick. After application of the dipole kick, the dipole moment decohered completely due to lattice nonlinearities. When a quadrupole kick is applied at time {tau} after the dipole kick, the beam re-cohered at time 2{tau} thus showing an echo response. We describe the experimental setup and measurement results. In the measurements the dipole and quadrupole kick amplitudes, amplitude dependent tune shift, and the time between dipole and quadrupole kick were varied. In addition, measurements were taken with gold bunches of different intensities. These should exhibit different transverse diffusion rates due to intra-beam scattering.

  18. Transverse vibration of nematic elastomer Timoshenko beams

    NASA Astrophysics Data System (ADS)

    Zhao, Dong; Liu, Ying; Liu, Chuang

    2017-01-01

    Being a rubber-like liquid crystalline elastomer, a nematic elastomer (NE) is anisotropic viscoelastic, and displays dynamic soft elasticity. In this paper, the transverse vibration of a NE Timoshenko beam is studied based on the linear viscoelasticity theory of nematic elastomers. The governing equation of motion for the transverse vibration of a NE Timoshenko beam is derived. A complex modal analysis method is used to obtain the natural frequencies and decrement coefficients of NE beams. The influences of the nematic director rotation, the rubber relaxation time, and the director rotation time on the vibration characteristic of NE Timoshenko beams are discussed in detail. The sensitivity of the dynamic performance of NE beams to director initial angle and relaxation times provides a possibility of intelligent controlling of their dynamic performance.

  19. Quantum interference between transverse spatial waveguide modes

    NASA Astrophysics Data System (ADS)

    Mohanty, Aseema; Zhang, Mian; Dutt, Avik; Ramelow, Sven; Nussenzveig, Paulo; Lipson, Michal

    2017-01-01

    Integrated quantum optics has the potential to markedly reduce the footprint and resource requirements of quantum information processing systems, but its practical implementation demands broader utilization of the available degrees of freedom within the optical field. To date, integrated photonic quantum systems have primarily relied on path encoding. However, in the classical regime, the transverse spatial modes of a multi-mode waveguide have been easily manipulated using the waveguide geometry to densely encode information. Here, we demonstrate quantum interference between the transverse spatial modes within a single multi-mode waveguide using quantum circuit-building blocks. This work shows that spatial modes can be controlled to an unprecedented level and have the potential to enable practical and robust quantum information processing.

  20. Transverse acousto-electric effect in superconductors

    NASA Astrophysics Data System (ADS)

    Lipavský, P.; Koláček, J.; Lin, P.-J.

    2016-06-01

    We formulate a theory based on the time-dependent Ginzburg-Landau (TDGL) theory and Newtonian vortex dynamics to study the transverse acousto-electric response of a type-II superconductor with Abrikosov vortex lattice. When exposed to a transverse acoustic wave, Cooper pairs emerge from the moving atomic lattice and moving electrons. As in the Tolman-Stewart effect in a normal metal, an electromagnetic field is radiated from the superconductor. We adapt the equilibrium-based TDGL theory to this non-equilibrium system by using a floating condensation kernel. Due to the interaction between normal and superconducting components, the radiated electric field as a function of magnetic field attains a maximum value occurring below the upper critical magnetic field. This local increase in electric field has weak temperature dependence and is suppressed by the presence of impurities in the superconductor.

  1. Damped transverse oscillations of interacting coronal loops

    NASA Astrophysics Data System (ADS)

    Soler, Roberto; Luna, Manuel

    2015-10-01

    Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations. Here we theoretically investigate resonantly damped transverse oscillations of interacting nonuniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. Analytic and numerical results in the specific case of two interacting loops are given as an application.

  2. Transversal Clifford gates on folded surface codes

    NASA Astrophysics Data System (ADS)

    Moussa, Jonathan E.

    2016-10-01

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surface codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. The specific application of these codes to universal quantum computation based on qubit fusion is also discussed.

  3. On the Evolution of Pulsatile Flow Subject to a Transverse Impulse Body Force

    NASA Astrophysics Data System (ADS)

    di Labbio, Giuseppe; Keshavarz-Motamed, Zahra; Kadem, Lyes

    2014-11-01

    In the event of an unexpected abrupt traffic stop or car accident, automotive passengers will experience an abrupt body deceleration. This may lead to tearing or dissection of the aortic wall known as Blunt Traumatic Aortic Rupture (BTAR). BTAR is the second leading cause of death in automotive accidents and, although quite frequent, the mechanisms leading to BTAR are still not clearly identified, particularly the contribution of the flow field. As such, this work is intended to provide a fundamental framework for the investigation of the flow contribution to BTAR. In this fundamental study, pulsatile flow in a three-dimensional, straight pipe of circular cross-section is subjected to a unidirectional, transverse, impulse body force applied on a strictly bounded volume of fluid. These models were simulated using the Computational Fluid Dynamics (CFD) software FLUENT. The evolution of fluid field characteristics was investigated during and after the application of the force. The application of the force significantly modified the flow field. The force induces a transverse pressure gradient causing the development of secondary flow structures that dissipate the energy added by the acceleration. Once the force ceases to act, these structures are carried downstream and gradually dissipate their excess energy.

  4. Ferrimagnetic behaviors in a transverse Ising nanoisland

    NASA Astrophysics Data System (ADS)

    Kaneyoshi, T.

    2016-05-01

    In this paper, the phase diagrams and magnetizations of a magnetic nanoisland described by the transverse Ising model (TIM) are investigated by the use of the effective-field theory (EFT) with correlations. A lot of characteristic behaviors observed in standard ferrimagnetic materials as well as novel phenomena have been obtained, although the system consists of two finite spin-1/2 layers coupled antiferromagnetically with a negative interlayer coupling.

  5. TRANSVERSE MODE ELECTRO-OPTIC MATERIALS.

    DTIC Science & Technology

    electro - optic modulators presently used are crystals such as KDP which exhibit a longitudinal electro - optic effect. It has been demonstrated that a more efficient modulator can be produced when a crystal having a transverse electro - optic effect is employed. Generally these crystals are produced either from the melt or from fluxes. Since melt grown crystals must be cooled through several hundred degrees and often must undergo phase transitions, these crystals are generally highly strained. Flux grown crystals are also

  6. Computed Tomography of Transverse Phase Space

    SciTech Connect

    Watts, A.; Johnstone, C.; Johnstone, J.

    2016-09-19

    Two computed tomography techniques are explored to reconstruct beam transverse phase space using both simulated beam and multi-wire profile data in the Fermilab Muon Test Area ("MTA") beamline. Both Filtered Back-Projection ("FBP") and Simultaneous Algebraic Reconstruction Technique ("SART") algorithms [2] are considered and compared. Errors and artifacts are compared as a function of each algorithm’s free parameters, and it is shown through simulation and MTA beamline profiles that SART is advantageous for reconstructions with limited profile data.

  7. Complementary methods of transverse emittance measurement

    SciTech Connect

    Zagel, James; Hu, Martin; Jansson, Andreas; Thurman-Keup, Randy; Yan, Ming-Jen; /Fermilab

    2008-05-01

    Several complementary transverse emittance monitors have been developed and used at the Fermilab accelerator complex. These include Ionization profile Monitors (IPM), Flying Wires, Schottky detectors and a Synchrotron Light Monitor (Synchlite). Mechanical scrapers have also been used for calibration purposes. This paper describes the various measurement devices by examining their basic features, calibration requirements, systematic uncertainties, and applications to collider operation. A comparison of results from different kinds of measurements is also presented.

  8. Transverse-momentum-dependent parton distributions (TMDs)

    SciTech Connect

    Bacchetta, Alessandro

    2011-10-24

    Transverse-momentum-dependent parton distributions (TMDs) provide three-dimensional images of the partonic structure of the nucleon in momentum space. We made impressive progress in understanding TMDs, both from the theoretical and experimental point of view. This brief overview on TMDs is divided in two parts: in the first, an essential list of achievements is presented. In the second, a selection of open questions is discussed.

  9. Electron in a transverse harmonic cavity

    SciTech Connect

    Honkanen, H.; Maris, P.; Vary, J.P.; Brodsky, S.J.; /SLAC

    2010-10-27

    We employ Hamiltonian light-front quantum field theory in a basis function approach to solve the non-perturbative problem of an electron in a strong scalar transverse confining potential. We evaluate both the invariant mass spectra and the anomalous magnetic moment of the lowest state for this two-scale system. The weak external field limit of the anomalous magnetic moment agrees with the result of QED perturbation theory within the anticipated accuracy.

  10. Transverse Mixing in a Natural River Channel

    NASA Astrophysics Data System (ADS)

    Swick, W. A.; Macmahan, J. H.; Reniers, A. J.; Thornton, E. B.; Brown, J.

    2010-12-01

    Transverse mixing in a river channel is investigated using field observations and a three-dimensional (3D) hydrodynamic model, Delft3D. Six fluorescent Rhodamine dye releases were conducted in a 30 m wide, 500 m long, and 2 m deep relatively straight reach in the Kootenai River, ID on 12-16 August 2010. The study reach contained a number of natural channel features, such as a pool-riffle sequence and bank irregularities, which influence transverse mixing. The dye was released at a constant rate for one hour from a kayak fixed in the center of the channel. River discharge was steady and all releases were conducted in the morning hours to avoid diurnal wind effects. Vertical dye concentrations and velocity profiles were measured near the source and four downstream locations: 25m, 100m, 300m and 500m. In addition to the stationary observations, two different roving dye sampling schemes were performed to increase the spatial dye concentration resolution. The first sampling scheme consisted of 5 evenly-spaced dye sensors being slowly moved upstream. The second scheme consisted of 3 dye sensors moved transversely across the channel at various streamwise channel locations. These observations provide the horizontal and vertical extent of the dye plume and the spatial and temporal variability of the dye concentration. Local flow structures, produced by the separation of flow over riffles and bank irregularities, strongly control the observed local concentration distributions. Qualitative calculations highlight the influence of channel irregularities on the rate of transverse mixing and quantitative inferences shed light on the dominant mixing processes operating within different parts of the channel. 1D analytical and 3D numerical model are used to assess the relative importance of turbulent diffusion and local flow structure on predicted spatial dye concentrations.

  11. 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

  12. Reconstruction of Kuwada grade IV chronic achilles tendon rupture by minimally invasive technique

    PubMed Central

    Miao, Xudong; Wu, Yongping; Tao, Huimin; Yang, Disheng; Huang, Lu

    2016-01-01

    Background: Transfer of a flexor hallucis longus (FHL) tendon can not only reconstruct the Achilles tendon but also provide ischemic tendinous tissues with a rich blood supply to enhance wound healing. This retrospective study aims to investigate clinical outcomes in patients who underwent repair of Kuwada grade IV chronic Achilles tendon rupture with long hallucis longus tendons harvested using a minimally invasive technique. Materials and Methods: 35 patients who were treated for Kuwada grade IV Achilles tendon injuries from July 2006 to June 2011 were included in this retrospective study. The age ranged between 23 and 71 years. The duration from primary injury to surgery ranged from 29 days to 34 months (mean value, 137.6 days). All 35 patients had difficulties in lifting their calves. Thirty two were followed up for a mean 32.2 months (range 18–72 months), whereas three were lost to followup. Magnetic resonance imaging (MRI) showed that the tendon rupture gap ranged from 6.0 to 9.2 cm. During surgery, a 2.0 cm minor incision was made vertically in the medial plantar side of the midfoot, and a 1.5 cm minor transverse incision was made in the plantar side of the interphalangeal articulation of the great toe to harvest the FHL tendon, and the tendon was fixed to the calcaneus with suture anchors. Postoperative appearance and function were evaluated by physiotherapists based American Orthopedic Foot and Ankle Society-ankle and hindfoot score (AOFAS-AH), and Leppilahti Achilles tendon ratings. Results: Results were assessed in 32 patients. Except for one patient who suffered complications because of wound disruption 10 days after the operation, all other patients had primary wound healing, with 28 of 32 able to go up on their toes at last followup. The AOFAS-AH score was increased from preoperative (51.92 ± 7.08) points to (92.56 ± 6.71) points; Leppilahti Achilles tendon score was increased from preoperative (72.56 ± 7.43) to (92.58 ± 5.1). There were

  13. Theoretical Overview on Recent Developments in Transverse Spin Physics

    SciTech Connect

    Yuan, Feng

    2009-01-14

    Transverse-spin physics has been very active and rapidly developing in the last few years. In this talk, I will briefly summarize recent theoretical developments, focusing on the associated QCD dynamics in transverse spin physics.

  14. 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.

  15. 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

  16. Creep rupture of a tropical wood polymer composite

    NASA Astrophysics Data System (ADS)

    Teoh, S. H.; Chia, L. H. L.; Boey, F. Y. C.

    Wood polymer composite (WPC) specimens were produced by impregnating a tropical wood with methyl methacrylate (MMA) and subsequently polymerised by gamma irradiation. Beam specimens of varying weight percentages of polymer were then subjected to three-point-bend creep rupture test under a constant load condition. Results indicated that the impregnation of MMA and subsequent polymerisation by irradiation to form WPC significantly increased the creep rupture resistance of the wood. Two models, namely, a three element non-linear mechanical model derived from an energy failure criterion and a power law model derived from a damage parameter concept, modelled adequately the creep rupture time of the WPC. The energy criterion model was useful because the equation parameters such as elastic modulus, anelastic modulus and resilience of WPC show a general trend of increase with the amount of polymer impregnated into the wood, and also it could predict the upper stress limit where the specimens rupture immediately on application of load and the lower stress limit where the specimens sustain the load indefinitely. Results indicated that the equation parameters increase significantly in the first 20 or 30% polymer loading in agreement with previous work. An interfacial interaction between the polymer and the wood cell wall was used to account for the behaviour of the increase in the creep rupture resistance.

  17. Prehistoric ruptures of the Gurvan Bulag fault, Gobi Altay, Mongolia

    USGS Publications Warehouse

    Prentice, C.S.; Kendrick, K.; Berryman, K.; Bayasgalan, A.; Ritz, J.F.; Spencer, J.Q.

    2002-01-01

    The 1957 Gobi Altay M8.3 earthquake in southern Mongolia was associated with the simultaneous rupture of several faults, including the Gurvan Bulag reverse fault, which is located about 25 km south of the main strike-slip Bogd fault. Our study of paleoseismic excavations across the Gurvan Bulag fault suggests that the penultimate surface rupture occurred after 6.0 ka, most likely between 2.6 and 4.4 ka, and a possible earlier rupture occurred after 7.3 ka. Our interpretation of the stratigraphic relations in one of the exposures suggests that at least five earthquakes have generated surface rupture of the Gurvan Bulag fault since the abandonment of an ancient alluvial fan surface. Luminescence dating of sediment associated with this surface indicates that it formed either 26.6 ?? 2.1 ka or 16.1 ?? 2.0 ka. These data imply that the recurrence intervals for surface faulting on the Gurvan Bulag and Bogd faults are similar, on the order of several thousands of years, but that the penultimate surface ruptures of the two faults did not occur during the same earthquake.

  18. 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.

  19. 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

  20. Influence of Plastic Deformation on Bimaterial Fault Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Templeton-Barrett, E. L.; Dedontney, N.; Rice, J. R.; Dmowska, R.

    2011-12-01

    Material juxtapositions across mature faults are a common occurrence. Previous work has found that this elastic mismatch results in a rupture that will preferentially propagate in the direction of slip displacement on the more compliant side of the fault, with more off-fault damage in the stiffer material. This result has implications for inferring preferred rupture directions based on observations of damage zone asymmetry. We perform a complete numerical investigation of the role of the stress state on the distribution of plastic deformation and the direction of preferred rupture propagation. We show that there are important factors, in addition to the elastic mismatch, which control the preferred direction of propagation as well as the side of the fault in which damage predominately accumulates. The orientation of the most compressive principal stress is the controlling factor in determining the location of plastic deformation. For different orientations, plastic deformation can accumulate in either the stiffer or the more compliant material. For high angles of most compressive stress, the aforementioned preferred rupture direction prediction holds true. However, the off-fault plastic response can reverse that direction for low angles of most compressive stress so that rupture will preferentially propagate in the direction of slip displacement in the stiffer material. Also, as already established in the case of purely elastic materials, when pre-stress is close to static friction (low seismic S ratio) a transition to supershear may take place in the direction opposite to what was the preferred direction.