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1

Strength of transversely isotropic rocks  

E-print Network

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

Pei, Jianyong, 1975-

2008-01-01

2

Rupture failure and mechanical strength of the electrode wire used in wire EDM  

Microsoft Academic Search

In the application of wire EDM, wire rupture is very troublesome and impedes further increase of cutting speed. Instead of the spark characteristics or the temperature distribution, the rupture mechanism and the mechanical strength of the wire are the focus of this investigation. Wire rupture is a mechanical failure in essence, although the process heat has significant influence on the

Y. F. Luo

1999-01-01

3

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

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

4

Studies on the chemical composition朿reep-rupture strength relation for heat-resistant nickel alloys  

Microsoft Academic Search

The results of creep-rupture data processing for heat-resistant nickel alloys by parametric methods, by the Trunin and base\\u000a diagram methods are presented. The line of investigations to establish the relation between the chemical composition and creep\\u000a rupture strength is considered.

V. V. Krivenyuk; R. I. Kuriat; G. V. Mukhopad; S. G. Kiselevskaya

2011-01-01

5

In Vitro Study of Transverse Strength of Fiber Reinforced Composites  

PubMed Central

Objective Reinforcement with fiber is an effective method for considerable improvement in flexural properties of indirect composite resin restorations. The aim of this in-vitro study was to compare the transverse strength of composite resin bars reinforced with pre-impregnated and non-impregnated fibers. Materials and Methods Thirty six bar type composite resin specimens (3󫎾5 mm) were constructed in three groups. The first group was the control group (C) without any fiber reinforcement. The specimens in the second group (P) were reinforced with pre-impregnated fibers and the third group (N) with non-impregnated fibers. These specimens were tested by the three-point bending method to measure primary transverse strength. Data were statistically analyzed with one way ANOVA and Tukey抯 tests. Results There was a significant difference among the mean primary transverse strength in the three groups (P<0.001). The post-hoc (Tukey) test showed that there was a significant difference between the pre-impregnated and control groups in their primary transverse strength (P<0.001). Regarding deflection, there was also a significant difference among the three groups (P=0.001). There were significant differences among the mean deflection of the control group and two other groups (PC&N<.001 and PC&P=.004), but there was no significant difference between the non-and pre-impregnated groups (PN&P=.813). Conclusion Within the limitations of this study, it was concluded that reinforcement with fiber considerably increased the transverse strength of composite resin specimens, but impregnation of the fiber used implemented no significant difference in the transverse strength of composite resin samples. PMID:22457836

Mosharraf, R.; Hashemi, Z.; Torkan, S.

2011-01-01

6

Metal-induced cell rupture in elongating roots is associated with metal ion binding strengths  

Microsoft Academic Search

Low concentrations of Al, Cu and La rapidly decrease root elongation and cause transverse ruptures to the rhizodermis and\\u000a outer cortex, but it is not known if other trace metals have similar effects. Six trace metals, Ga, Gd, Hg, In, Ru, and Sc,\\u000a decreased cowpea root growth and caused ruptures similar to those caused by Al, Cu and La. Calculated

P. M. Kopittke; B. A. McKenna; F. P. C. Blamey; J. B. Wehr; N. W. Menzies

2009-01-01

7

Rupture Strength of Several Nickel-base Alloys in Sheet Form  

NASA Technical Reports Server (NTRS)

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.

Dance, James H; Clauss, Francis J

1957-01-01

8

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

9

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

NASA Technical Reports Server (NTRS)

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.

Reeder, James R.

2014-01-01

10

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

NASA Astrophysics Data System (ADS)

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.

Grimes-Ledesma, Lorie

11

Creep and Rupture Strength of an Advanced CVD SiC Fiber  

NASA Technical Reports Server (NTRS)

In the as-produced condition the room temperature strength (approx. 6 GPa) of Textron Specialty Materials' 50 microns CVD SiC fiber represents the highest value thus far obtained for commercially produced polycrystalline SiC fibers. To understand whether this strength can be maintained after composite processing conditions, high temperature studies were performed on the effects of time, stress, and environment on 1400 deg. C tensile creep strain and stress rupture on as-produced, chemically vapor deposited SiC fibers. Creep strain results were consistent, allowing an evaluation of time and stress effects. Test environment had no influence on creep strain but I hour annealing at 1600 deg. C in argon gas significantly reduced the total creep strain and increased the stress dependence. This is attributed to changes in the free carbon morphology and its distribution within the CVD SiC fiber. For the as-produced and annealed fibers, strength at 1400 deg. C was found to decrease from a fast fracture value of 2 GPa to a 100-hr rupture strength value of 0. 8 GPa. In addition a loss of fast fracture strength from 6 GPa is attributed to thermally induced changes in the outer carbon coating and microstructure. Scatter in rupture times made a definitive analysis of environmental and annealing effects on creep strength difficult.

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

1997-01-01

12

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

NASA Technical Reports Server (NTRS)

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

Reeder, James R.

2012-01-01

13

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

14

Die separation and rupture strength for deep reactive ion etched silicon wafers  

NASA Astrophysics Data System (ADS)

The work herein analyzes the bending stress required to separate and rupture die from notched silicon wafers. Trenches are formed on the wafers using either a dicing or Bosch deep reactive ion etching (DRIE) process. Weibull distribution parameters are reported for all variations of the fracture experiments. Additionally, the relative defect rate associated with DRIE-based die separation are compared with traditional saw methods for a variety of notch depths. Results indicate that the DRIE-based separation technique offers improved rupture strength over the traditional methods, but can also greatly reduce die strength if performed improperly. Dies completely separated by the DRIE process showed a mean failure stress of 1.16 GPa with a Weibull standard deviation of 682 MPa compared to 452 and 65 MPa mean and standard deviation stress for die completely separated by a traditional dicing saw.

Porter, D. A.; Berfield, T. A.

2013-08-01

15

Transverse tensile and stress rupture properties of gamma/gamma prime-delta directionally solidified eutectic  

NASA Technical Reports Server (NTRS)

Tensile and stress rupture properties were determined primarily at 760 C for specimens oriented at various angles (0 deg, 10 deg, 45 deg, and 90 deg) from the solidification direction of bars and/or slabs of the Ni-20Cb-6Cr-2.5A (gamma/gamma prime-delta) eutectic. Threaded-head specimens yielded longer rupture lives with significantly less scatter than did tapered-head specimens. Miniature specimens are suitable for determining traverse tensile and rupture properties of 1.2 centimeter diameter bar stock. The 300 hour rupture stress at 760 C for specimens oriented at 10 deg from the solidification direction was reduced from 740 to 460 MPa, and to 230 MPa for material oriented at either 45 deg or 90 deg.

Gray, H. H.

1976-01-01

16

Scale effects on the transverse tensile strength of graphite epoxy composites  

NASA Technical Reports Server (NTRS)

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.

Obrien, T. Kevin; Salpekar, Satish A.

1992-01-01

17

Comparisons of 76Hz transverse and radial magnetic field strength components received in Connecticut  

NASA Astrophysics Data System (ADS)

Since June 1970, we have made extremely low frequency (ELF) measurements of the transverse horizontal magnetic field strength, H sub phi, received in Connecticut. Occasionally, we also have measured either the vertical electric field strength, E sub v, or the radial horizontal magnetic field strength, H sub rho. The AN/BSR-1 ELF receivers are located at the Naval Underwater Systems Center (NUSC), at New London, CT. The transmission source for these farfield (1.6-Mm range) measurements is the U.S. Navy's ELF Wisconsin Test Facility (WTF), located in the Chequamegon National Forest in north-central Wisconsin. The results of 136 days of radial magnetic field measurements taken from November 1977 through June 1984 are discussed in this report. The main result is that during disturbed propagation conditions, the radial and transverse magnetic field strength daily plots (versus GMT) are usually dissimilar (in both amplitude and relative phase).

Bannister, P. R.

1986-03-01

18

Size effect on buckling strength of eccentrically compressed column with fixed or propagating transverse crack  

Microsoft Academic Search

The strength and size effect of a slender eccentrically compressed column with a transverse pre-existing traction-free edge\\u000a crack or notch is analyzed. Rice and Levy抯 spring model is applied to simulate the effect of a crack or notch. An approximate,\\u000a though accurate, formula is proposed for the buckling strength of the column of variable size. Depending on the eccentricity,\\u000a the

Zaoyang Guo; Zden?k P. Ba瀉nt

2006-01-01

19

Creep Rupture Strength and Microstructure of Low C-10Cr-2Mo Heat-Resisting Steels with V and Nb  

NASA Astrophysics Data System (ADS)

The new ferritic heat-resisting steels of 0.05C-10Cr-2Mo-0.10V-0.05Nb (Cb) composition with high creep rupture strength and good ductility have already been reported. The optimum amounts of V and Nb that can be added to the 0.05C-10Cr-2Mo steels and their effects on the creep rupture strength and microstructure of the steels have been studied in this experiment. The optimum amounts of V and Nb are about 0.10 pct V and 0.05 pct Nb at 600 癈 for 10,000 h, but shift to 0.18 pct V and 0.05 pct Nb at 650 癈. Nb-bearing steels are preferred to other grades on the short-time side, because NbC precipitation during initial tempering stages delays recovery of martensite. On the long-time side, however, V-bearing steels have higher creep rupture strength. By adding V to the steels, electron microscopic examination reveals a stable microstructure, retardation during creep of the softening of tempered martensite, fine and uniform distribution of precipitates, and promotion of the precipitation of Fe2Mo.

Fujita, T.; Asakura, K.; Sawada, T.; Takamatsu, T.; Otoguro, Y.

1981-06-01

20

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

SciTech Connect

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

Kumar, Sanjeev [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH (United Kingdom); Thomas, K. J. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK and Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Smith, L. W.; Farrer, I.; Ritchie, D. A.; Jones, G. A. C.; Griffiths, J. [Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 OHE (United Kingdom); Pepper, M. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK and Department of Electrical and Electronic Engineering, Torrington Place, London WC1E 7JE (United Kingdom)

2013-12-04

21

Weathering effects on tensile and stress rupture strength of glass fiber reinforced vinylester and epoxy thermoset pipes  

NASA Astrophysics Data System (ADS)

Glass fiber reinforced vinylester (GFRE) and epoxy (GFRE) pipes have been used for more than three decades to mitigate corrosion problems in oil fields, chemical and industrial plants. In these services, both GFRV and GFRE pipes are exposed to various environmental conditions. Long-term mechanical durability of these pipes after exposure to environmental conditions, which include natural weathering exposure to seasonal temperature variation, sea water, humidity and other corrosive fluids like crude oil, should be well known. Although extensive research has been undertaken, several major issues pertaining to the performance of these pipes under a number of environmental conditions still remain unresolved. The main objective of this study is to investigate the effects of natural weathering, combined natural weathering with seawater and crude oil exposure, for time periods ranging from 3 to 36 months respectively, on the tensile and stress rupture behavior of GFRV and GFRE pipes. Ring specimens are machined from GFRV and GFRE pipes and tested before and after exposure to different weathering conditions prevalent in the eastern region (Dhahran) of Saudi Arabia and present under service conditions. The natural weathering and combined natural weathering with crude oil exposure of GFRV specimens revealed increased tensile strength even after 36 months of exposure when compared with that of the as received samples. However, the combined natural weathering with seawater exposure of GFRV samples revealed better tensile behavior till 24 months of exposure, and after 36 months their tensile strength was seen to be below that of the as received GFRV samples. The stress rupture behavior of natural weather exposed GFRV samples showed an improvement after 12 months of exposure and it decreased after 24 and 36 months of exposure when compared with the as received GFRV samples. The combined natural weathering with crude oil and seawater exposure of GFRV sample revealed improved stress rupture behavior after 12 months of exposure. The as received GFRE pipe specimens revealed higher average tensile strength when compared to the as received GFRV sample, whereas the stress rupture behavior was comparatively low. The seawater exposure of the GFRE specimens resulted in drastic reduction in both tensile and stress rupture properties. Fractographic analysis was performed using an optical microscope and SEM in order to explain the possible controlling mechanisms of failure.

Nizamuddin, Syed

22

Abaca Fiber Reinforced Phosphogypsum Concrete Panels (modulus Of Rupture, Toughness, Splitting Tensile Strength)  

Microsoft Academic Search

In this experimental study the possibilities of utilization of phosphogypsum--industrial waste--in concrete, reinforced with abaca vegetable fibers, were investigated. Effects of varying the abaca fiber content and the phosphogypsum content on flexural, tensile and compressive strengths and ductility of concrete were examined. The flexural behavior of abaca fiber reinforced phosphogypsum concrete panels was studied extensively and compared with gypsum wall

Selcuk Yetimoglu

1984-01-01

23

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

NASA Technical Reports Server (NTRS)

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.

OBrien, T. Kevin; Krueger, Ronald

2001-01-01

24

Modeling for fracture in materials under long-term static creep loading and neutron irradiation. Part 2. Prediction of creep rupture strength for austenitic materials  

Microsoft Academic Search

We present some results of prediction of creep rupture strength and plasticity for austenitic materials prior to and after\\u000a irradiation with variable neutron flux rates, based on physicomechanical model as outlined in Part 1. The calculated results\\u000a are compared with the available experimental data.

B. Z. Margolin; A. G. Gulenko; I. P. Kursevich; A. A. Buchatskii

2006-01-01

25

Techniques for Strength Measurement at High Pressures and Strain-Rates Using Transverse Waves  

NASA Astrophysics Data System (ADS)

The study of the strength of a material is relevant to a variety of applications including automobile collisions, armor penetration and inertial confinement fusion. Although dynamic behavior of materials at high pressures and strain-rates has been studied extensively using plate impact experiments, the results provide measurements in one direction only. Material behavior that is dependent on strength is unaccounted for. The research in this study proposes two novel configurations to mitigate this problem. The first configuration introduced is the oblique wedge experiment, which is comprised of a driver material, an angled target of interest and a backing material used to measure in-situ velocities. Upon impact, a shock wave is generated in the driver material. As the shock encounters the angled target, it is reflected back into the driver and transmitted into the target. Due to the angle of obliquity of the incident wave, a transverse wave is generated that allows the target to be subjected to shear while being compressed by the initial longitudinal shock such that the material does not slip. Using numerical simulations, this study shows that a variety of oblique wedge configurations can be used to study the shear response of materials and this can be extended to strength measurement as well. Experiments were performed on an oblique wedge setup with a copper impactor, polymethylmethacrylate driver, aluminum 6061-t6 target, and a lithium fluoride window. Particle velocities were measured using laser interferometry and results agree well with the simulations. The second novel configuration is the y-cut quartz sandwich design, which uses the anisotropic properties of y-cut quartz to generate a shear wave that is transmitted into a thin sample. By using an anvil material to back the thin sample, particle velocities measured at the rear surface of the backing plate can be implemented to calculate the shear stress in the material and subsequently the strength. Numerical simulations were conducted to show that this configuration has the ability to measure the strength for a variety of materials.

Richmond, Victoria Stolyar

26

Small Earthquakes and Pressure Solution in the Central Transverse Ranges: Inelastic Strain Unaccounted for by Large Earthquake Ruptures  

NASA Astrophysics Data System (ADS)

Earthquakes can be used to characterize geometry and kinematics of seismogenic faults. Seismogenically insignificant faults may be important structurally and for strain accumulation. An example is the seismicity triggered by the Northridge mainshock in the hangingwall block of the Santa Susana thrust fault. This seismicity is diffuse and thus involves many faults, yet shows uniform fault kinematics. Abundant and quality-controlled hypocenters and focal mechanisms from our SCEC data set (REF) show slip planes parallel to and kinematically consistent with a major ramp on the Santa Susana thrust fault. We interpret this seismicity to stem from flexural folding of the Santa Susana thrust and its hangingwall block in response to antithetic reverse 1994 faulting event in the footwall block. The seismogenic moment released by flexural-slip in the Northridge aftershocks may represent a small portion of the total strain accounted by this folding. Furthermore, folding structurally coupled with a fault appears to take place in tandem with major ruptures on the fault. The 1994 rupture as imaged by aftershocks matches well the position, shape, and slip-geometry of the rupture modeled from the mainshock. Generally, aftershocks that can be directly associated with the rupture are concentrated at its outer limits, but the densest concentration is at the base of the seismogenic zone. This deep cluster is also unusually stable in rate and slip kinematics. Similar characteristics are noted for deep aftershocks of other large ruptures in California and elsewhere. These aftershocks suggest creep near the brittle-ductile transition and may mark a buffer zone of mixed behavior. They may also therefore account for much more deformation than represented by the seismogenic moment. Pressure solution also accounts for significant aseismic crustal strain. In a survey along the San Cayetano fault we distinguish and assess three components of pressure-solution deformation associated with the current compressive regime: 1) solution at clast or grain boundaries, 9-23% shortening; 2) discrete cleavage planes, 1-32% shortening; and 3) aseismic slip on small (gouge-free) faults, 2-8% shortening. The direction of maximum shortening in folded strata tends to be horizontal for small faults but is bedding-parallel for grain-boundary solution and for cleavage. This suggests that different components of pressure solution strain are significant and dominate in different parts or stages of the compressional orogen.

Seeber, L.; Armbruster, J. G.; Vermilye, J.

2001-12-01

27

The eutectic carbides and creep rupture strength of 25Cr20Ni heat-resistant steel tubes centrifugally cast with different solidification conditions  

Microsoft Academic Search

The eutectic carbides and creep rupture strength of 25Cr20Ni heat-resistant steel tubes centrifugally cast with different solidification conditions were investigated in detail. The results reveal that the eutectic carbides precipitated primarily at the dendrite and grain boundaries show various morphologies from the outer wall to the inner wall along radial direction of the cast tubes, consisting of the thin film-like

X. Q Wu; H. M Jing; Y. G Zheng; Z. M Yao; W Ke; Z. Q Hu

2000-01-01

28

286 / JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING / MARCH 2000 shear strength before reinforcement rupture, which is not sup-  

E-print Network

286 / JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING / MARCH 2000 shear strength before, rather than to the decrease in soil shear strength from peak to residual values due to shear dis soil shear strength for both defining the location of the slip surface and calculating

Zornberg, Jorge G.

29

A Comparison of Creep Rupture Strength of Ferritic/Austenitic Dissimilar Weld Joints of Different Grades of Cr-Mo Ferritic Steels  

NASA Astrophysics Data System (ADS)

Evaluations of creep rupture properties of dissimilar weld joints of 2.25Cr-1Mo, 9Cr-1Mo, and 9Cr-1MoVNb steels with Alloy 800 at 823 K were carried out. The joints were fabricated by a fusion welding process employing an INCONEL 182 weld electrode. All the joints displayed lower creep rupture strength than their respective ferritic steel base metals, and the strength reduction was greater in the 2.25Cr-1Mo steel joint and less in the 9Cr-1Mo steel joint. Failure location in the joints was found to shift from the ferritic steel base metal to the intercritical region of the heat-affected zone (HAZ) of the ferritic steel (type IV cracking) with the decrease in stress. At still lower stresses, the failure in the joints occurred at the ferritic/austenitic weld interface. The stress-life variation of the joints showed two-slope behavior and the slope change coincided with the occurrence of ferritic/austenitic weld interface cracking. Preferential creep cavitation in the soft intercritical HAZ induced type IV failure, whereas creep cavitation at the interfacial particles induced ferritic/austenitic weld interface cracking. Micromechanisms of the type IV failure and the ferritic/austenitic interface cracking in the dissimilar weld joint of the ferritic steels and relative cracking susceptibility of the joints are discussed based on microstructural investigation, mechanical testing, and finite element analysis (FEA) of the stress state across the joint.

Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Goyal, Sunil; Mathew, M. D.

2012-04-01

30

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

PubMed Central

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 (?= 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

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

2013-01-01

31

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

32

Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance  

ERIC Educational Resources Information Center

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

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

2009-01-01

33

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

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

Oborn, B. M.; Metcalfe, P. E.; Butson, M. J.; Rosenfeld, A. B. [Illawarra Cancer Care Centre (ICCC), Wollongong, New South Wales 2500 (Australia) and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia); Illawarra Cancer Care Centre (ICCC), Wollongong, New South Wales 2500 (Australia); Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, New South Wales 2500 (Australia)

2010-10-15

34

What Is an Earthquake?: Fault-Rupture Analogies  

NSDL National Science Digital Library

This activity has two parts: the first part will demonstrate the weaknesses of simple fault models (like block diagrams) in depicting the process of fault rupture accurately; and the second part is centered around a fairly simple animation of rupture propagation, seen by an oblique map view, that attempts to show more accurately what we should envision when we think about fault rupture. This activity provides different analogies for describing the process of fault rupture, with attention paid to the strengths and weaknesses of each.

35

Supersonic Rupture of Rubber  

E-print Network

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

M Marder

2005-04-24

36

Creep-rupture of polymer-matrix composites. [graphite-epoxy laminates  

NASA Technical Reports Server (NTRS)

An accelerated characterization method for resin matrix composites is reviewed. Methods for determining modulus and strength master curves are given. Creep rupture analytical models are discussed as applied to polymers and polymer matrix composites. Comparisons between creep rupture experiments and analytical models are presented. The time dependent creep rupture process in graphite epoxy laminates is examined as a function of temperature and stress level.

Brinson, H. F.; Griffith, W. I.; Morris, D. H.

1980-01-01

37

Shallow Dynamic Overshoot and Energetic Deep Rupture in the 2011 Mw 9.0 Tohoku-Oki Earthquake  

Microsoft Academic Search

Strong spatial variation of rupture characteristics in the moment magnitude (Mw) 9.0 Tohoku-Oki megathrust earthquake controlled both the strength of shaking and the size of the tsunami that followed. Finite-source imaging reveals that the rupture consisted of a small initial phase, deep rupture for up to 40 seconds, extensive shallow rupture at 60 to 70 seconds, and continuing deep rupture

Satoshi Ide; Annemarie Baltay; Gregory C. Beroza

2011-01-01

38

Open re-rupture of the Achilles tendon after surgical treatment  

PubMed Central

The rate of re-rupture of Achilles tendon after surgical treatment were reported to 1.75.6% previously. Re-rupture of Achilles tendon generally occurs subcutaneously. We experienced two rare cases of the open re-ruptures of Achilles tendon with a transverse wound perpendicular to the primary surgical incision. Re-rupture occurred 4 and 13 weeks after surgical treatment. We suggest that open re-rupture correlates more closely with skin scaring and shortening. Another factor may be adhesion between the subcutaneous scar and the suture of the paratenon and Achilles tendon with post-operative immobilization. PMID:24765375

Hanada, Mitsuru; Takahashi, Masaaki; Matsuyama, Yukihiro

2011-01-01

39

Rupture of the diaphragm  

PubMed Central

Christiansen, L. A., Stage, P., Bille Brahe, E., and Bertelsen, S. (1974).Thorax, 29, 559-563. Rupture of the diaphragm. A 23-year series of 25 patients with rupture of the diaphragm is presented. Symptoms, diagnostic procedures, and treatment are mentioned. A high index of suspicion of the diagnosis of ruptured diaphragm is most important in patients with a history of trauma. Familiarity with the signs on the plain chest film is important. Furthermore, we advocate an additional examination, that is diagnostic pneumoperitoneum, in all cases of suspected rupture of the diaphragm. If doubt still exists, we consider the final diagnostic procedure of choice to be exploratory thoracotomy until proof of the complete reliability of diagnostic pneumoperitoneum has been established. Images PMID:4428456

Christiansen, L. A.; Stage, P.; Bille Brahe, E.; Bertelsen, S.

1974-01-01

40

Achilles tendon rupture - aftercare  

MedlinePLUS

Managing Your: Achilles Tendon Rupture. In: Ferri FF, ed. Ferri's Clinical Advisor 2015 . 1st ed. Philadelphia, PA: Mosby Elsevier; 2014: appendix V. Sokolove PE, Barnes DK. Extensor and Flexor Tendon Injuries ...

41

New Empirical Relationships among Magnitude, Rupture Length, Rupture Width, Rupture Area, and Surface Displacement  

Microsoft Academic Search

Source parameters for historical earthquakes worldwide are com- piled to develop a series of empirical relationships among moment magnitude (M), surface rupture length, subsurface rupture length, downdip rupture width, rupture area, and maximum and average displacement per event. The resulting data base is a significant update of previous compilations and includes the ad- ditional source parameters of seismic moment, moment

Donald L. Wells; Kevin J. Coppersmith

1994-01-01

42

Creep rupture behavior of Stirling engine materials  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

43

Achilles Tendon Rupture  

PubMed Central

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 搃njury and 搑isk factors and 揳thletes 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

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

2013-01-01

44

Clinical recovery of two hip adductor longus ruptures: a case-report of a soccer player  

PubMed Central

Background Non-operative treatment of acute hip adductor longus ruptures in athletes has been described in the literature. However, very limited information concerning the recovery of this type of injury exists. This case represented a unique possibility to study the recovery of two acute adductor longus ruptures, using novel, reliable and validated assessment methods. Case presentation A 22-year old male soccer player (Caucasian) sustained two subsequent acute adductor longus ruptures, one in each leg. The injuries occurred 10爉onths apart, and were treated non-surgically in both situations. He was evaluated using hip-strength assessments, self-report and ultrasonography until complete muscle-strength recovery of the hip adductors had occurred. The player was able to participate in a full soccer training session without experiencing pain 15爓eeks after the first rupture, and 12爓eeks after the second rupture. Full hip adductor muscle-strength recovery was obtained 52爓eeks after the first rupture and 10爓eeks after the second rupture. The adductor longus injuries, as verified by initial ultrasonography (10燿ays post-injury), showed evidence of a complete tendon rupture in both cases, with an almost identical imaging appearance. It was only at 6 and 10爓eeks ultrasonographic follow-up that the first rupture was found to include a larger anatomical area than the second rupture. Conclusion From this case we can conclude that two apparently similar hip adductor longus ruptures, verified by initial ultrasonography (10燿ays post-injury), can have very different hip adductor strength recovery times. Assessment of adductor strength recovery may therefore in the future be a useful and important additional measure for determining when soccer players with hip adductor longus ruptures can return safely to play. PMID:23693119

2013-01-01

45

Transversity 2005  

NASA Astrophysics Data System (ADS)

Introduction. Purpose and status of the Italian Transversity Project / F. Bradamante -- Opening lecture. Transversity / M. Anselmino -- Experimental lectures. Azimuthal single-spin asymmetries from polarized and unpolarized hydrogen targets at HERMES / G. Schnell (for the HERMES Collaboration). Collins and Sivers asymmetries on the deuteron from COMPASS data / I. Horn (for the COMPASS Collaboration). First measurement of interference fragmentation on a transversely polarized hydrogen target / P. B. van der Nat (for the HERMES Collaboration). Two-hadron asymmetries at the COMPASS experiment / A. Mielech (for the COMPASS Collaboration). Measurements of chiral-odd fragmentation functions at Belle / R. Seidl ... [et al.]. Lambda asymmetries / A. Ferrero (for the COMPASS Collaboration). Transverse spin at PHENIX: results and prospects / C. Aidala (for the PHENIX Collaboration). Transverse spin and RHIC / L. Bland. Studies of transverse spin effects at JLab / H. Avakian ... [et al.] (for the CLAS Collaboration). Neutron transversity at Jefferson Lab / J. P. Chen ... [et al.] (for the Jefferson Lab Hall A Collaboration). PAX: polarized antiproton experiments / M. Contalbrigo. Single and double spin N-N interactions at GSI / M. Maggiora (for the ASSIA Collaboration). Spin filtering in storage rings / N. N. Nikolaev & F. F. Pavlov -- Theory lectures. Single-spin asymmetries and transversity in QCD / S. J. Brodsky. The relativistic hydrogen atom: a theoretical laboratory for structure functions / X. Artru & K. Benhizia. GPD's and SSA's / M. Burkardt. Time reversal odd distribution functions in chiral models / A. Drago. Soffer bound and transverse spin densities from lattice QCD / M. Diehl ... [et al.]. Single-spin asymmetries and Qiu-Sterman effect(s) / A. Bacchetta. Sivers function: SIDIS data, fits and predictions / M. Anselmino ... [et al.]. Twist-3 effects in semi-inclusive deep inelastic scattering / M. Schlegel, K. Goeke & A. Metz. Quark and gluon Sivers functions / I. Schmidt. Sivers effect in semi-inclusive deeply inelastic scattering and Drell-Yan / J. C. Collins ... [et al.]. Helicity formalism and spin asymmetries in hadronic processes / M. Anselmino ... [et al.]. Including Cahn and Sivers effects into event generators / A. Kotzinian. Comparing extractions of Sivers functions / M. Anselmino ... [et al.]. Anomalous Drell-Yan asymmetry from hadronic or QCD vacuum effects / D. Boer. "T-odd" effects in transverse spin and azimuthal asymmetries in SIDIS / L. P. Gamberg & G. R. Goldstein. T-odd effects in unpolarized Drell-Yan scattering / G. R. Goldstein & L. P. Gamberg. Alternative approaches to transversity: how convenient and feasible are they? / M. Radici. Relations between single and double transverse asymmetries / O. V. Teryaev. Cross sections, error bars and event distributions in simulated Drell-Yan azimuthal asymmetry measurements / A. Bianconi. Next-to-leading order QCD corrections for transversely polarized pp and p痯 collisions / A. Mukherjee, M. Stratmann & W. Vogelsang. Double transverse-spin asymmetries in Drell-Yan and J/[symbol] production from proton-antiproton collisions / M. Guzzi ... [et al.]. The quark-quark correlator: theory and phenomenology / E. Di Salvo. Chiral quark model spin filtering mechanism and hyperon polarization / S. M. Troshin & N. E. Tyurin -- Closing lecture. Where we've been ... and where we're going / G. Bunce.

Barone, Vincenzo; Ratcliffe, Philip G.

46

Transversity 2008  

NASA Astrophysics Data System (ADS)

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. K鋐er (for the COMPASS collaboration) -- Measurement of azimuthal asymmetries of the unpolarized cross-section at HERMES / F. Giordano (for the HERMES collaboration) -- Measurement of transversity via an interference fragmentation function at HERMES / R. Fabbri (for the HERMES collaboration) -- Relating leading and higher twist contributions to nucleon spin structure / P. G. Ratcliffe and O. V. Teryaev -- DIS at low and high transverse momentum: matches and mismatches / A. Bacchetta ... [et al.] -- Pretzelosity distribution function h[symbol] / H. Avakian ... [et al.] -- Transverse momentum-spin correlations / L. P. Gamberg, G. R. Goldstein and M. Schlegel -- Exploring confinement with spin / J. P. Ralston -- SIDIS asymmetries in quark-diquark model / A. Kotzinian -- Parton densities in a spectator model with axial-vector diquarks / M. Radici -- Gluonic pole matrix elements in spectator models / A. Mukherjee, L. P. Gamberg and P. J. Mulders -- TMD measurements at CLAS6 and CLAS12 / H. Avakian (for the CLAS6 and CLAS12 collaborations) -- Nucleon to pion transition distribution amplitudes in a light-cone quark model / M. Pincetti, B. Pasquini and S. Boffi -- Antiproton polarization studies for FAIR (How to polarize antiprotons and what to use them for?) / H. Str鰄er, F. Rathmann and P. Lenisa -- No one can encompass the unencompassable: the highlights of transversity-2008 / N. N. Nikolaev.

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

2009-04-01

47

Quantitative relations between earthquake source properties from dynamic rupture simulations incorporating off-fault plasticity  

NASA Astrophysics Data System (ADS)

High stress concentrations at earthquake rupture fronts may generate inelastic off-fault response around the rupture tip, leading to increased energy absorption in the damage zone. Accounting for off-fault plasticity in earthquake rupture simulations imposes physical limits on extreme ground motion as plastic dissipation limits the rupture speed and peak slip rate of pulses. We present physics-based relations between earthquake source parameters derived from analytic considerations and from a consistent set of 2D dynamic rupture models that incorporate severe velocity-weakening friction and off-fault plasticity assuming homogeneous initial conditions. Specifically, we deduce a non-linear relation between the peak slip velocity and rupture speed, which holds for sub- and super-shear, crack- and pulse-like ruptures. We find that these relations are statistically consistent with the correlation of peak slip rate and rupture speed in 3D dynamic rupture models under linear slip weakening friction and highly heterogeneous initial stress. Furthermore the closeness to failure (CF) parameter introduced by Templeton and Rice (2008) is an adequate predictor of rupture speed for slow ruptures, whereas rupture speeds larger than ~80% S-wave speed have a more complicated dependence on stress orientation and the relative strength of the fault. These relations, combined with the limits on rupture speed imposed by off-fault plasticity, may encapsulate a major influence of plastic deformation on near-field ground motions. Our study captures fundamental processes governing dynamic rupture propagation coupled to self-similar off-fault energy dissipation. Thus, our results may be a suitable starting point to develop new pseudo-dynamic source parametrizations for source inversion and ground motion prediction that account for off-fault plasticity. We will report on the suitability of these relations in the presence of other sources of rupture complexity, e.g. coalescing rupture fronts.

Gabriel, Alice; Ampuero, Jean-Paul; Dalguer, Luis A.; Mai, P. Martin

2013-04-01

48

Creep and creep rupture of strongly reinforced metallic composites  

NASA Technical Reports Server (NTRS)

A creep and creep damage theory is presented for metallic composites with strong fibers. Application is to reinforced structures in which the fiber orientation may vary throughout but a distinct fiber direction can be identified locally (local transverse isotropy). The creep deformation model follows earlier work and is based on a flow potential function that depends on invariants reflecting stress and the material symmetry. As the focus is on the interaction of creep and damage, primary creep is ignored. The creep rupture model is an extension of continuum damage mechanics and includes an isochronous damage function that depends on invariants specifying the local maximum transverse tension and the maximum longitudinal shear stress. It is posited that at high temperature and low stress, appropriate to engineering practice, these stress components damage the fiber/matrix interface through diffusion controlled void growth, eventually causing creep rupture. Experiments are outlined for characterizing a composite through creep rupture tests under transverse tension and longitudinal shear. Application is made to a thin-walled pressure vessel with reinforcing fibers at an arbitrary helical angle. The results illustrate the usefulness of the model as a means of achieving optimal designs of composite structures where creep and creep rupture are life limiting.

Robinson, D. N.; Binienda, W. K.; Miti-Kavuma, M.

1990-01-01

49

Creep Rupture Properties of Welded Joints of Heat Resistant Steels  

NASA Astrophysics Data System (ADS)

In this study, the high-temperature mechanical and creep rupture properties of Grade 91/Grade 91 (Mod. 9Cr-Mo) similar welded joints and Grade 91/Inconel 82/SUS304 dissimilar welded joints were examined. The effects of temperature and stress on the failure location in the joints were also investigated. Creep rupture tests were conducted at 823, 873, and 923 K; the applied stress ranges were 160-240, 80-160, and 40-80 MPa, respectively. The creep rupture strengths of the specimens with welded joints were lower than those of the specimens of the base metal at all temperature levels; in addition, these differences in creep strength increased with temperature. After being subjected to long-term creep rupture tests, the fracture type exhibited by the dissimilar welded joints was transformed from Types V and VII to Type IV. It was estimated that the fracture type exhibited by the dissimilar welded joints after 100,000-h rupture strength tests at 823 K and 873 K was Type IV fracture.

Yamazaki, Masayoshi; Watanabe, Takashi; Hongo, Hiromichi; Tabuchi, Masaaki

50

Neonatal bladder rupture.  

PubMed

Neonatal bladder rupture is rare as a complication of bladder obstruction due to abnormal anatomy or iatrogenic cause such as umbilical catheterization. The present study describes the case of a 27-day old infant with ascites due to bladder perforation secondary to bladder wall necrosis as a result of severe urinary tract infection. The baby was treated aggressively with antibiotics and underwent successful surgical repair of the perforation. PMID:19205633

Tran, Hoang; Nguyen, Ngoc; Nguyen, Tap

2009-04-01

51

Rupture of renal transplant.  

PubMed

Background. Rupture of renal allograft is a rare and serious complication of transplantation that is usually attributed to acute rejection, acute tubular necrosis, or renal vein thrombosis. Case Presentation. LD, a 26-year-old male with established renal failure, underwent deceased donor transplantation using kidney from a 50-year-old donor with acute kidney injury (Cr 430?mmol/L). LD had a stormy posttransplant recovery and required exploration immediately for significant bleeding. On day three after transplant, he developed pain/graft swelling and another significant haemorrhage with cardiovascular compromise which did not respond to aggressive resuscitation. At reexploration, the renal allograft was found to have a longitudinal rupture and was removed. Histology showed features of type IIa Banff 97 acute vascular rejection, moderate arteriosclerosis, and acute tubular necrosis. Conclusion. Possible ways of avoiding allograft rupture include use of well-matched, good quality kidneys; reducing or managing risk factors that would predispose to delayed graft function; ensuring a technically satisfactory transplant procedure with short cold and warm ischemia times; and avoiding large donor-recipient age gradients. PMID:25685589

Baker, Shona; Popescu, Maria; Akoh, Jacob A

2015-01-01

52

Rupture of Renal Transplant  

PubMed Central

Background. Rupture of renal allograft is a rare and serious complication of transplantation that is usually attributed to acute rejection, acute tubular necrosis, or renal vein thrombosis. Case Presentation. LD, a 26-year-old male with established renal failure, underwent deceased donor transplantation using kidney from a 50-year-old donor with acute kidney injury (Cr 430?mmol/L). LD had a stormy posttransplant recovery and required exploration immediately for significant bleeding. On day three after transplant, he developed pain/graft swelling and another significant haemorrhage with cardiovascular compromise which did not respond to aggressive resuscitation. At reexploration, the renal allograft was found to have a longitudinal rupture and was removed. Histology showed features of type IIa Banff 97 acute vascular rejection, moderate arteriosclerosis, and acute tubular necrosis. Conclusion. Possible ways of avoiding allograft rupture include use of well-matched, good quality kidneys; reducing or managing risk factors that would predispose to delayed graft function; ensuring a technically satisfactory transplant procedure with short cold and warm ischemia times; and avoiding large donor-recipient age gradients. PMID:25685589

Baker, Shona; Popescu, Maria; Akoh, Jacob A.

2015-01-01

53

Transverse Myelitis  

MedlinePLUS

... If an individual begins to recover limb control, physical therapy begins to help improve muscle strength, coordination, and ... years and in some cases longer--requiring aggressive physical therapy and rehabilitation. However, if there is no improvement ...

54

Oxidation induced stress-rupture of fiber bundles  

SciTech Connect

The effect of oxidation on the stress-rupture behavior of fiber bundles was modeled. It is shown that oxidation-induced fiber strength degradation results in the delayed failure of the associated fiber bundle and that the fiber bundle strength decreases with time as t{sup {minus}1/4}. It is also shown that the temperature dependence of the bundle loss of strength reflects the thermal dependence of the mechanism controlling the oxidation of the fibers. The effect of gauge length on the fiber bundle strength was also analyzed. Numerical examples are presented for the special case of Nicalon{trademark} fibers.

Lara-Curzio, E.

1997-03-01

55

Effects of Pre-Stress State and Rupture Velocity on Dynamic Fault Branching  

NASA Astrophysics Data System (ADS)

We consider a mode II rupture which propagates along a planar main fault and encounters an intersection with a branching fault that makes an angle with the main fault. Within a formulation that allows the failure path to be dynamically self-chosen, we study the following questions: Does the rupture start along the branch? Does it continue? Which side is most favored for branching, the extensional or compressional? Does rupture continue on the main fault too? What path is finally self-chosen? Failure in the modeling is described by a slip-weakening law for which the peak and residual strength, and strength at any particular amount of slip, is proportional to normal stress. We use the elastodynamic boundary integral equation method to allow simulations of rupture along the branched fault system. Our results show that dynamic stresses around the rupturing fault tip, which increase with rupture velocity at locations off the main fault plane, relative to those on it, could initiate rupture on a branching fault. As suggested by prior work [Poliakov, Dmowska and Rice, 2002, http://esag.harvard.edu/dmowska/PDR.pdf], whether a branching rupture, once begun, can be continued to a larger scale depends on principal stress directions in the pre-stress state and on rupture velocity. The most favored side for rupture transferring on a branching fault switches from the extensional side to the compressive side as we consider progressively shallower angles of the direction of maximum pre-compression with the main fault. Simultaneous rupturing on both faults is usually difficult for a narrow branching angle due to strong stress interaction between faults, which discourages rupture continuation on the other side. However, it can be activated by enhanced dynamic stressing when the rupture velocity is very near the limiting velocity (Rayleigh wave velocity for mode II). It can also be activated when the branching angle is wide because of decreasing stress interaction between faults. Natural examples seem consistent with the simulations we present.

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

2002-12-01

56

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

NASA Technical Reports Server (NTRS)

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.

Saulsberry, Regor

2010-01-01

57

Creep-rupture reliability analysis  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

58

Stress-rupture behavior of small diameter polycrystalline alumina fibers  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

59

Ruptured Intracranial Dermoid Cyst Associated with Rupture of Cerebral Aneurysm  

PubMed Central

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

Kim, Ki Hong

2011-01-01

60

Spontaneous rupture of the oesophagus  

Microsoft Academic Search

Background: The aim of this study was to evaluate the diagnosis, management and outcome of patients with spontaneous rupture of the oesophagus in a single centre. Methods: Between October 1993 and May 2007, 51 consecutive patients with spontaneous oesophageal rupture were evaluated with contrast radiology and flexible endoscopy. Patients with limited contamination who fulfilled specific criteria were managed by a

S. M. Griffin; P. J. Lamb; J. Shenfine; D. L. Richardson; D. Karat; N. Hayes

2008-01-01

61

Plantar Fascia Ruptures in Athletes  

Microsoft Academic Search

Objective: To educate sports medicine practitioners as to length of time for an athlete to return to activity after sustaining a rupture of the plantar fascia.Methods: Athletic patients sustaining plantar fascia ruptures and subsequent treatment were reviewed. Diagnosis was based on clinical findings, although radiographic studies were done. Patients were treated for 2 to 3 weeks with a below-knee or

Amol Saxena; Brian Fullem

2004-01-01

62

Surgical treatment options for patella tendon rupture, part II: chronic.  

PubMed

Patella tendon rupture is a debilitating injury that often occurs in the setting of preexisting tendon degeneration. Prompt diagnosis and treatment is essential to prevent retraction of the patella with subsequent adhesions and quadriceps contractures. In the setting of a chronic rupture, augmentation with hamstring tendons or allograft reconstruction generally is necessary. Patients who undergo delayed repair are at risk for a compromised result secondary to loss of full knee flexion and decreased quadriceps strength, although a functional extensor mechanism is likely to be reestablished. Overall the results of chronic repair are less satisfactory than the acute repair, but still provide an extensor mechanism for the patient and thus provide function. PMID:16119741

Greis, Patrick E; Lahav, Amit; Holmstrom, Michael C

2005-08-01

63

Strength enhancement process for prealloyed powder superalloys  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

64

Long-term creep-rupture failure envelope of epoxy  

NASA Astrophysics Data System (ADS)

An accelerated testing methodology based on the time-temperature superposition principle has been proposed in the literature for the long-term creep strength of polymer matrices and polymer composites. Also, it has been suggested that a standard master curve may be a feasible assumption to describe the creep behavior in both tension and compression modes. In the present research, strength master curves for an aerospace epoxy (8552) were generated for tension and compression, by shifting strength data measured at various temperatures. The shift function is obtained from superposition of creep-compliance curves obtained at different temperatures. A standard master curve was presented to describe the creep-rupture of the polymer under tension and compression. Moreover, long-term creep-rupture failure envelopes of the polymer were presented based on a two-part failure criterion for homogeneous and isotropic materials. Ultimately, the approach presented allows the prediction of creep-rupture failure envelopes for a time-dependent material based on tensile strengths measured at various temperatures, considering that the ratio between tensile and compressive strengths is known.

Melo, Jos Daniel D.; de Medeiros, Antonio M.

2014-02-01

65

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

PubMed

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

Beedholm, Kirsten; Lomborg, Kirsten; Frederiksen, Kirsten

2014-04-01

66

Shallow dynamic overshoot and energetic deep rupture in the 2011 Mw 9.0 Tohoku-Oki earthquake.  

PubMed

Strong spatial variation of rupture characteristics in the moment magnitude (M(w)) 9.0 Tohoku-Oki megathrust earthquake controlled both the strength of shaking and the size of the tsunami that followed. Finite-source imaging reveals that the rupture consisted of a small initial phase, deep rupture for up to 40 seconds, extensive shallow rupture at 60 to 70 seconds, and continuing deep rupture lasting more than 100 seconds. A combination of a shallow dipping fault and a compliant hanging wall may have enabled large shallow slip near the trench. Normal faulting aftershocks in the area of high slip suggest dynamic overshoot on the fault. Despite prodigious total slip, shallower parts of the rupture weakly radiated at high frequencies, whereas deeper parts of the rupture radiated strongly at high frequencies. PMID:21596957

Ide, Satoshi; Baltay, Annemarie; Beroza, Gregory C

2011-06-17

67

Advancements in identifying biomechanical determinants for abdominal aortic aneurysm rupture.  

PubMed

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. PMID:24757027

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

2015-02-01

68

Steam generator tube rupture study  

E-print Network

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

Free, Scott Thomas

1986-01-01

69

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

70

Complex rupture during the 12 January 2010 Haiti earthquake  

USGS Publications Warehouse

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.

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

71

The Principles of Strength and Fatigue in Optical Fibers  

Microsoft Academic Search

Tensile strength is defined as the applied stress (tensile load per unit cross-sectional area) recorded at the instant of rupture for a test specimen. Historically, attempts to catalogue and report the intrinsic strength of glass were frustrated by considerable dispersion in the acquired measurement data. In addition to large variability, typical strength values were found to be one, two or

J. Carr; S. Saikkonen

1986-01-01

72

Ruptures of the distal biceps tendon.  

PubMed

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. PMID:25150334

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

2014-01-01

73

Creep-rupture tests of internally pressurized Inconel 702 tubes  

NASA Technical Reports Server (NTRS)

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.

Gumto, K. H.

1973-01-01

74

Creep and rupture of advanced ceramic fiber reinforcements  

SciTech Connect

For high temperature CMC to achieve technical and commercial success, ceramic fiber reinforcements should display high stiffness, high strength, and good retention of these properties well above 1000{degrees}C. Using recent data for fiber creep and rupture, this paper reviews the advances that have been made in understanding and improving the thermomechanical performance of multifilament and monofilament fibers with compositions based on alumina and SiC. Although basic and technical progress has been significant, research and developmental issues still remain.

Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States); DiCarlo, J.A. [NASA Lewis Research Center, Cleveland, OH (United States)

1995-12-01

75

Shear Strength Model for Lightly Reinforced Concrete Columns  

Microsoft Academic Search

Parameters affecting the shear strength of reinforced concrete columns having a rectangular cross section and light transverse reinforcement are investigated using data from numerous column tests. A new model is proposed to predict the column shear strength based on theoretical formulations and experimental evidence. The proposed shear strength equation includes contributions from the concrete and transverse reinforcement. Primary parameters in

Halil Sezen

2004-01-01

76

Flexor pulley reconstruction after rupture following corticosteroid injections for trigger thumb: a case report.  

PubMed

We report a rare case of limitation of active flexion and subcutaneous bow-stringing as a result of flexor pulley rupture after repeated corticosteroid injections for trigger thumb. Complete rupture of the A1 and oblique flexor pulleys was confirmed during surgery, and the pulley system was reconstructed with a "three-loop technique" using a free palmaris longus autograft. This technique provided enough strength to allow early mobilization and prompt recovery to full range of motion. PMID:24156592

Kimura, Michio; Kuroshima, Nagatsugu; Matsushita, Takashi

2013-01-01

77

A simplified method for repair of distal biceps tendon ruptures.  

PubMed

Repair of distal biceps brachii tendon ruptures is recommended for active individuals desiring maximum return of elbow supination and flexion strength. A 2-incision method of repair has been most popular but carries a risk of radioulnar synostosis. In the past, repair through a single anterior incision required more dissection and risked injury to the posterior interosseous nerve. The authors present a simplified method for the repair of distal biceps tendon ruptures through a single anterior incision. The use of suture anchors provides secure fixation to the radius with minimal volar dissection. This method was used successfully in 16 patients, 8 acutely (<6 weeks) and 8 chronically, with excellent functional results. Patients who received acute repairs regained elbow strength and power; patients who received chronic repairs showed slight deficits of supination strength (16%) and flexion power (14%). Of 10 chronic ruptures treated, only 2 tendons could not be mobilized back to the radial tuberosity and had to be transferred to the brachialis. There were no failures and no complications of radioulnar synostosis or posterior interosseous nerve palsy. The single anterior incision approach in which suture anchors are used is recommended as an alternative to the traditional 2-incision method. PMID:10888168

Sotereanos, D G; Pierce, T D; Varitimidis, S E

2000-01-01

78

Self-Rupturing Hermetic Valve  

NASA Technical Reports Server (NTRS)

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-energizing and requires low force compared to current pyrotechnic-based burst disk hermetic valves. This is a novel design for producing a single-use, self-rupturing, hermetically sealed valve for isolation of pressurized gas and/or liquids. This design can also be applied for single-use disposable valves for chemical instruments. A welded foil diaphragm is fully supported by two mated surfaces that are machined to micron accuracies using EDM. To open the valve, one of the surfaces is moved relative to the other to (a) remove the support creating an unsupported diaphragm that ruptures due to over pressure, and/or (b) produce tension in the diaphragm and rupture it.

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

2011-01-01

79

Spontaneous Forniceal Rupture in Pregnancy  

PubMed Central

Forniceal rupture is a rare event in pregnancy. We report a case of a 26-year-old primigravid woman who experienced a forniceal rupture at 23 weeks of gestation with no inciting cause except for pregnancy. Pregnancy is associated with ureteral compression due to increase in pelvic vasculature with the right ureter more dilated due to anatomic reasons. Hormones such as prostaglandins and progesterone render the ureter more distensible to allow for pressure build-up and an obstructive picture at the collecting system. We will discuss physiologic changes in pregnancies that predispose to this uncommon phenomenon and the most up-to-date management strategies. PMID:25648411

Upputalla, Roshni; Moore, Robert M.; Jim, Belinda

2015-01-01

80

Exploring the Relationship Between Early Rupture History and Final Earthquake Size  

NASA Astrophysics Data System (ADS)

A question of considerable contention in the seismological community is whether earthquakes follow the cascade model or the preslip model of earthquake rupture. In the preslip model, earthquake ruptures are generated by an initial slip distribution in a nucleation zone, which loads the fault in proportion to the magnitude of this early slip. In this model, earthquake size is a deterministic result of the early rupture process, and can be determined through observations while the rupture is ongoing. In the cascade model, the rupture is initiated on a particular asperity on the fault, and that failure applies increased stress to adjacent portions of the fault. Each adjacent patch either propagates the rupture forward or stops its propagation, depending on whether local conditions on each individual patch are favorable to rupture or not. The local geometry of the fault and the strength of the host rock, as well as the local distribution of stresses, all affect how favorable a given fault patch is to rupture. Earthquake size in this model is inherently non-deterministic, as no portion of the rupture front feels the effects of barriers (unfavorable patches) until it has propagated into them and stopped. As a result, this model does not allow for the final size of the earthquake to be known until the rupture has completely stopped propagating. We use a Support Operators (Ely et al., 2007) model to simulate dynamic rupture of a rectangular planar fault with stochastic heterogeneous initial shear stress. By varying the initial shear stress near the point of nucleation we can control the intensity of the early rupture in terms of stress drop, moment release and other parameters. We investigate the effect of different characteristics of early rupture on the final distribution of slip on the fault. Results suggest that under realistic initial stress distributions, earthquake rupture exhibits elements of both cascade and preslip behavior, and that it is possible to alter significantly the final size of the earthquake with comparatively small changes in the character of the early rupture.

Wurman, G.; Oglesby, D. D.; Allen, R. M.

2007-12-01

81

[Proximal and distal ruptures of the biceps brachii tendon].  

PubMed

Proximal ruptures. Ruptures of the long head of the M. biceps humeri are commonly caused by degenerative changes within the tendon. Non-operative treatment gives good results, the loss of power regarding elbow flexion and supination amounts to only 8-21%. Refixation may be indicated for cosmetic reasons and offers a small but evident improvement of flexion and supination power. Deformity of the slipped muscle can be corrected effectively. Residual complaints after conservative treatment often result from associated subacromial problems. Distal ruptures. Ruptures of the distal tendon should be treated operatively. The loss of power after conservative treatment is evident (30-40% for flexion, >50% for supination). Extra-anatomical tenodesis to the brachialis muscle or anatomical fixation to the radial tuberosity can be applied. Flexion power and cosmesis can be addressed by both techniques. If supination strength is to be restored, the tendon has to be fixed anatomically. Preparation of the tuberosity bears the risk of heterotopic ossification or nerve damage. Mini-open techniques, using only a limited anterior approach, may decrease risks. PMID:14959750

Klonz, A; Loitz, D; Reilmann, H

2003-09-01

82

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2010 CFR

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

2010-10-01

83

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

84

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

85

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2014 CFR

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

2014-10-01

86

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

87

Implications of Style-of-Faulting and Loading Characteristics on the Dynamic Rupture Process  

NASA Astrophysics Data System (ADS)

Assuming that shear failure on pre-existing faults of shallow earthquakes is governed by Coulomb friction, the mode of faulting and the loading history in compressional and extensional tectonic regimes play an important role in determining the absolute value of frictional strength (e.g. Sibson, 1991) and the initial stress on the fault prior to rupture. Considering for example a fault system under confining pressure equivalent to the gravitational load, then the tectonic loading in a compressional regime accumulates shear stress on the fault while simultaneously frictional strength is expected to increase due to increasing normal stress. In contrast, the loading in an extensional regime results in a reduction of the shear strength due to decreasing normal stress. In this case, the resulting strength of the fault would not be able to maintain large shear stresses because the normal stress at shallow depth is limited to the gravitational loading. We examine the implications of these loading regimes for the dynamic rupture process by developing a variety of dynamic models on thrust, normal and vertical strike-slip faults. For each class of model we combine stochastic irregularities in initial stress, compatible with seismological observations and findings from previous dynamic rupture simulations, with the external tectonic loading. Due to the nature of the fault systems described above, the normal stress is depth dependent, consequently the frictional strength (static and dynamic sliding strength) is also depth dependent. Our tectonic loading scheme generates uniformly increasing shear stress on the fault plane until a nucleation criterion is met (Ripperger et al 2007). Assuming that the fault rupture is governed by linear slip-weakening friction, we perform spontaneous dynamic rupture simulations to examine the rupture complexity and specific characteristics of these classes of models.

Dalguer, L. A.; Mai, M.

2008-12-01

88

Quadriceps Tendon Rupture due to Postepileptic Convulsion  

PubMed Central

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

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

2014-01-01

89

Distal biceps and triceps ruptures.  

PubMed

Biceps and triceps tendon ruptures are rather uncommon injuries and are most commonly diagnosed clinically. Magnetic resonance imaging can help the clinician to differentiate an incomplete tear and define any degeneration of the tendon. Surgical anatomical repair is typically performed in acute complete ruptures whereas nonoperative treatment can be used for partial ruptures, as well as for patients unfit for surgery. Single incision techniques are associated with a higher rate of nerve injuries, while double incision repairs have a higher prevalence of heterotopic ossification. Although various fixation methods have been applied including bone tunnels, interference screws, suture anchors, cortical button fixation, the current evidence does not support the superiority of one method over the other. A well-planned postoperative rehabilitation programme is essential for a good final outcome. As better fixation devices are being used, more aggressive rehabilitation programmes have been applied. Epidemiology, clinical evaluation, diagnosis, surgical and conservative management of these injuries are presented in this review along with the authors' preferred technique for the anatomical repair of acute complete ruptures. PMID:23352149

Kokkalis, Zinon T; Ballas, Efstathios G; Mavrogenis, Andreas F; Soucacos, Panayotis N

2013-03-01

90

NPR fuel rupture monitor system tests  

Microsoft Academic Search

The fuel rupture monitoring system at the New Production Reactor (NPR) has the following features and innovations which are not present on the rupture monitors at the other Hanford reactors: (1) each process tube is individually monitored for a fuel element rupture, (2) the electronics of the system are completely transistorized, and (3) the process water is monitored for gross

1964-01-01

91

A Retrospective Analysis of Ruptured Breast Implants  

PubMed Central

Background Rupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants. Methods We performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone), duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management. Results Forty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case), microfat graft (2 case), removal only (14 case), and follow-up loss (17 case). Conclusions Saline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs. PMID:25396188

Baek, Woo Yeol; Lew, Dae Hyun

2014-01-01

92

Estimation of Dynamic Rupture Parameters of the 1999 Duzce, Turkey Earthquake  

NASA Astrophysics Data System (ADS)

The 1999 Kocaeli(Mw:7.4) and Duzce (Mw:7.1), Turkey Earthquakes have in common a specific rupture characteristic: Ruptures propagated eastward from hypocenters by supershear rupture velocity. Dynamic rupture properties of the Kocaeli Earthquake have been studied by several researchers. In order to better understand propagation characteristics of the northern branch of the NAFZ as well as judging whether or not the supershear propagation is a systematic feature of this fault zone, rupture dynamics of the 1999 D鼁ce, Turkey Earthquake has been investigated. The parameterization of the dynamic model, that describes the friction law and stress state on the fault, has been constrained with the slip distribution on the fault plane calculated from the kinematic waveform inversion of near field strong motion records. These parameters have been used as input for dynamic code. Dynamic stress drop was calculated by iterative dynamic rupture simulation by assuming an initial stress drop distribution through kinematic inversion results and changing the stress drop distribution until the slip distribution from dynamic model and that of kinematic model match to each other. Strength excess parameter was estimated by a trial and error scheme from a series of dynamic rupture simulation until the total rupture time be equivalent to the total rupture time of kinematic model. Calculation of slip weakening distance and its definition for dynamic simulation is still subject under investigations. Recent investigations showed that Dc varies in rough proportion to the total slip, so it is variable in space. In this sense, critical slip weakening distances is assumed to be between 10- 30% of the total slip of kinematic model and the first time peak slip-velocity of kinematic model correspond to time of the slip-weakening distance. For the calculation a full dynamic rupture simulation code, namely Support Operator Rupture Dynamic Code(SORD) developed by, Ely et.al,( 2008) has been employed. The results of this study will be used for a full dynamic rupture simulation for the generation of low frequency velocity ground motion and are expected to provide important insight into the nature of the rupture-induced directivity and super-shear rupture observed in this earthquake.

Tanircan, Gulum; Dalguer, Luis; Nur Bekler, Feyza; Meral Ozel, Nurcan

2010-05-01

93

A viscoelastic model for axonal microtubule rupture.  

PubMed

Axon is an important part of the neuronal cells and axonal microtubules are bundles in axons. In axons, microtubules are coated with microtubule-associated protein tau, a natively unfolded filamentous protein in the central nervous system. These proteins are responsible for cross-linking axonal microtubule bundles. Through complimentary dimerization with other tau proteins, bridges are formed between nearby microtubules creating bundles. Formation of bundles of microtubules causes their transverse reinforcement and has been shown to enhance their ability to bear compressive loads. Though microtubules are conventionally regarded as bearing compressive loads, in certain circumstances during traumatic brain injuries, they are placed in tension. In our model, microtubule bundles were formed from a large number of discrete masses. We employed Standard Linear Solid model (SLS), a viscoelastic model, to computationally simulate microtubules. In this study, we investigated the dynamic responses of two dimensional axonal microtubules under suddenly applied end forces by implementing discrete masses connected to their neighboring masses with a Standard Linear Solid unit. We also investigated the effect of the applied force rate and magnitude on the deformation of bundles. Under tension, a microtubule fiber may rupture as a result of a sudden force. Using the developed model, we could predict the critical regions of the axonal microtubule bundles in the presence of varying end forces. We finally analyzed the nature of microtubular failure under varying mechanical stresses. PMID:25835789

Shamloo, Amir; Manuchehrfar, Farid; Rafii-Tabar, Hashem

2015-05-01

94

Barriers to faulting in the Basin-Range province: evidence from the Sou Hills transverse block  

SciTech Connect

Transverse structural blocks may inhibit the propagation of fault ruptures in the Basin-Range province. The Sou Hills, between Dixie and Pleasant Valleys, is a block of uplifted Tertiary bedrock transverse to the NNE-SSW trend of the central Nevada seismic belt. Three lines of evidence indicate that offset due to normal faulting is much less in the Sou Hills compared to adjacent segments of the seismic belt. First, estimates of total late Cenozoic offsets of pre-extension basalts show that the total offset is less in the Sou Hills. Second, analyses of landforms that reflect rates of relative uplift show that Quaternary tectonic activity on range-bounding faults declines where faults join the Sou Hills. Third, measurements of late Quaternary fault scarps show that individual rupture segments in the Sou Hills are shorter in length and have smaller displacements compared to the nearly continuous ruptures of several meters offset found along the Tobin and Stillwater Ranges to the north and south. The Sou Hills rupture pattern is distinctive: ruptures are dispersed over a wide zone rather than being concentrated along well-defined range fronts. Normal faulting patterns produced by the 1915 Pleasant Valley, Nevada and the 1983 Borah Peak, Idaho earthquakes indicate that a discontinuous, spatially dispersed faulting style typifies ruptures which die out in transverse bedrock features. These historic analogues support a model for prehistoric faulting in which ruptures have repeatedly died out in the Sou Hills. Transverse blocks such as the Sou Hills appear to present barriers to propagating ruptures.

Fonseca, J.E.

1985-01-01

95

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

SciTech Connect

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.

Cloos, M. (Univ. of Texas, Austin (United States))

1992-07-01

96

Models for earthquake rupture propagation  

NASA Astrophysics Data System (ADS)

The basic processes associated with earthquake rupture propagation are poorly understood. In particular the crack-tip problem is singular when considered in terms of a stress-intensity factor. We introduce the Barenblatt cohesive zone to remove this singularity and consider a uniformly propagating, mode III crack that bisects a strip. Downstream of the crack tip we consider both a stress-free condition and a viscous resistance on the crack surface. The technique of matched asymptotic expansions is used to obtain solutions. However, with a stress-free boundary condition a Griffith energy balance for the initiation of rupture in terms of cohesive forces is obtained but the solution does not determine a rupture speed. The available elastic energy must be greater than the energy required to break the cohesive bond. With a viscous resistance to slip on the crack surface, the tip singularity associated with the outer solution is reduced from {1}/{2} to a smaller value and a velocity of crack propagation is found. The rupture initiation criterion is unaffected by the viscosity while, as the viscous or cohesive forces are decreased, the rupture velocity increases towards the shear-wave velocity. Our results are similar to those obtained by Nakanishi [Nakanishi, H., 1994. Continuum model of mode-III crack propagation with surface friction. Phys. Rev. E49, 5412-5419.] applying a Wiener-Hopf technique to a related problem. We believe that our solution provides an explanation for the observation of Heaton (slip) pulses during earthquakes. We suggest that there are two slip-mode regimes during an earthquake rupture. In the immediate vicinity of the crack tip, slip velocities are very small and cohesive forces dominate. This is the regime that has been studied experimentally in the laboratory; plastic deformation of the surfaces and gouge dominate and the drop in the frictional stress is small. At higher slip velocities, away from the crack tip, there is a second frictional mode with low frictional stresses. This may be due to the fluidization of the granular fault gauge and provides a rational basis for a transition from cohesion to viscous resistance on the crack surface. As the driving stress drops the slip velocity decreases, there is a return to the cohesive mode and the fault locks and heals.

Morgan, J. D.; Turcotte, D. L.; Ockendon, J. R.

1997-08-01

97

Instabilities at frictional interfaces: Creep patches, nucleation, and rupture fronts  

NASA Astrophysics Data System (ADS)

The strength and stability of frictional interfaces, ranging from tribological systems to earthquake faults, are intimately related to the underlying spatially extended dynamics. Here we provide a comprehensive theoretical account, both analytic and numeric, of spatiotemporal interfacial dynamics in a realistic rate-and-state friction model, featuring both velocity-weakening and velocity-strengthening behaviors. Slowly extending, loading-rate-dependent creep patches undergo a linear instability at a critical nucleation size, which is nearly independent of interfacial history, initial stress conditions, and velocity-strengthening friction. Nonlinear propagating rupture fronts梩he outcome of instability梔epend sensitively on the stress state and velocity-strengthening friction. Rupture fronts span a wide range of propagation velocities and are related to steady-state-front solutions.

Bar-Sinai, Yohai; Spatschek, Robert; Brener, Efim A.; Bouchbinder, Eran

2013-12-01

98

Surface transverse waves on langasite  

NASA Astrophysics Data System (ADS)

Surface transverse waves (STW) are numerically simulated on langasite. As our method of investigation, we compute the admittance of an infinite synchronous resonator. The resonance and antiresonance frequencies are evaluated as functions of the crystal cut, temperature, and the thickness of the aluminium electrodes. For optimal parameters, we demonstrate a vanishing first-order temperature coefficient at room temperature and find a coupling strength several times stronger than that for Rayleigh waves in ST quartz. In particular, we find that the sensitivity of the resonance frequency to variations in the thickness of the aluminium electrodes is significantly lower in langasite than in ST quartz.

Koskela, J.; Lehtonen, S.; Plessky, V. P.; Salomaa, M. M.

1998-05-01

99

Spontaneous rupture of the ureter.  

PubMed

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

Eken, A; Akbas, T; Arpaci, T

2015-02-01

100

Influence of initial stress and rupture initiation parameters on forbidden zone rupture propagation  

NASA Astrophysics Data System (ADS)

Well established theoretical and numerical results of 2-D ruptures have been accepted for years to limit the speed of mode II cracks to be below the Rayleigh velocity or above the shear wave speed. However, recent work has numerically produced rupture speeds in this so-called `forbidden zone', that is the region of rupture velocities between the Rayleigh wave speed and the shear wave speed, for 3-D simulations. We verify that finding here and further examine the dependence of that behaviour on initial stress and rupture initiation parameters. Using a 3-D finite element model for dynamic rupture propagation, numerical experiments were performed for different initial stress conditions as well as different size initiation patches and forced rupture velocities. It is shown that the initial stress on the fault has a strong influence on the resulting rupture, specifically with regards to the distance at which the rupture transitions to supershear speeds, the maximum rupture velocity attained on the fault, and how rapidly the rupture passes through the forbidden zone. It is also demonstrated that for the same initial stress, increasing the size of the nucleation patch or the speed of forced rupture can artificially increase the gradient of the rupture velocity within the forbidden zone. This suggests that the rupture is uniquely predetermined by the stress state and material properties of the fault and surrounding medium in these models.

Payne, R. M.; Duan, B.

2015-04-01

101

Creep-rupture tests of internally pressurized Rene 41 tubes  

NASA Technical Reports Server (NTRS)

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.

Gumto, K. H.; Weiss, B.

1972-01-01

102

Method and apparatus for determining tensile strength  

DOEpatents

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.

Ratigan, J.L.

1982-05-28

103

Method and apparatus for determining tensile strength  

DOEpatents

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.

Ratigan, Joe L. (Rapid City, SD)

1984-01-01

104

Investigation of cryogenic rupture disc design  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

105

Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

106

Neck curve polynomials in neck rupture model  

SciTech Connect

The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of {sup 280}X{sub 90} with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.

Kurniadi, Rizal; Perkasa, Yudha S.; Waris, Abdul [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung 40132 (Indonesia)

2012-06-06

107

Quadriceps and patellar tendon ruptures.  

PubMed

The diagnosis of quadriceps and patellar tendon ruptures requires a high index of suspicion and thorough history-taking to assess for medical comorbidities that may predispose patients to tendon degeneration. Radiographic assessment with plain films supplemented by ultrasound and magnetic resonance imaging when the work-up is equivocal further aids diagnosis; however, advanced imaging is often unnecessary in patients with functional extensor mechanism deficits. Acute repair is preferred, and transpatellar bone tunnels serve as the primary form of fixation when the tendon rupture occurs at the patellar insertion, with or without augmentation depending on surgeon preference. Chronic tears and disruptions following total knee arthroplasty are special cases requiring reconstructions with allograft, synthetic mesh, or autograft. Rehabilitation protocols generally allow immediate weight-bearing with the knee locked in extension and crutch support. Limited arc motion is started early with active flexion and passive extension and then advanced progressively, followed by full active range of motion and strengthening. Complications are few but include quadriceps atrophy, knee stiffness, and rerupture. Outcomes are excellent if repair is done acutely, with poorer outcomes associated with delayed repair. PMID:23955186

Lee, Dennis; Stinner, Daniel; Mir, Hassan

2013-10-01

108

Strength Training  

MedlinePLUS

... comfortably perform the exercise for 8 to 15 repetitions. Before you begin any type of strength training ... added weight. Perform three sets of 8-15 repetitions (or reps) of each exercise, starting out with ...

109

Variability of seismic source spectra derived from cohesive-zone models of circular rupture  

NASA Astrophysics Data System (ADS)

Static stress drop of earthquakes is often estimated from far-field body-wave spectra using measurements of corner frequencies, together with seismic moment, which can be computed from the low-frequency part of the spectrum. Corner frequencies are used to infer the source dimension based on a specific theoretical model. The most widely used model is from Madariaga (1976), who considered a bilateral rupture expanding at a constant speed on a circular fault. This model assumes that the rupture front is characterized by an abrupt change of fault strength from a uniform initial prestress to a kinetic frictional stress, and hence the stress is singular at the rupture front. In this study, we investigate variability of source spectra derived from dynamic models of expanding bilateral ruptures on a circular fault with a cohesive zone that prevents a stress singularity at the rupture front. We study the dependence of far-field body-wave spectra on the rate of frictional weakening, rupture speed, and dynamic stress drop. Our results show that P- and S-wave corner frequencies of displacement spectra are systematically larger than those predicted by Madariaga (1976). Well-resolved stopping phases generated at the edge of the slipping zone result in a shorter source duration and hence higher corner frequencies. For ruptures propagating at 90 percent of the S-wave speed, models with the cohesive-zone size much smaller than the source dimension show that the azimuthal average of P-wave corner frequencies is about 20 percent larger than that of Madariaga (1976). Thus for these ruptures, application of the Madariaga model overestimates stress drops by factors of 1.7.

Kaneko, Y.; Shearer, P. M.

2013-12-01

110

Fractal avalanche ruptures in biological membranes  

NASA Astrophysics Data System (ADS)

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.

G鰖en, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

2010-11-01

111

Ruptured abdominal aortic aneurysm after endovascular repair  

Microsoft Academic Search

Objective: The purpose of this study was to present the experience with aneurysm rupture after deployment of Guidant\\/EVT (Guidant) endografts and review previously reported cases with other devices. Methods: Records from Guidant\\/EVT clinical trials and postmarket approval databases from February 1993 to August 2000 were analyzed to identify patients with rupture and to extract pertinent data. Previously reported cases were

Victor M. Bernhard; R. Scott Mitchell; Jon S. Matsumura; David C. Brewster; Maria Decker; Patrick Lamparello; Dieter Raithel; Jack Collin

2002-01-01

112

Free wall rupture after arterial switch operation.  

PubMed

A neonate underwent arterial switch operation, supported on extracorporeal membrane oxygenation for 3 days. Two weeks later, a pseudoaneurysm was seen on an echocardiogram, and a free wall rupture was suggested. Prompt surgery was performed, a free wall rupture assessed, and a patch with BioGlue was applied successfully. One year later, the child is in good condition. PMID:25468102

Gil-Jaurena, Juan-Miguel; Aroca, 羘gel; P閞ez-Caballero, Ram髇; Pita, Ana

2014-12-01

113

Neonatal splenic rupture: an unusual manifestation  

Microsoft Academic Search

Neonatal splenic rupture is relatively rare [4] and is usually associated with a traumatic delivery [3]. The clinical manifestation are those of hemorrhage and hypovolemic shock. We present two unusual cases of spontaneous neonatal splenic rupture whose initial clinical manifestation was a hematocele of the scrotal sac. The clinical presentation, diagnostic approach, and management of such cases is discussed with

David Bader; Jorge G. Mogilner; Anna Berger; Samuel Eldar; Daniel Reich; Leonardo Siplovich

1993-01-01

114

Spontaneous intraventricular rupture of craniopharyngioma cyst  

Microsoft Academic Search

BACKGROUNDRupture of a cystic craniopharyngioma is a rare phenomenon. The rupture of the cyst causes decompression of the adjacent neural structures resulting in spontaneous improvement of the visual symptoms or level of sensorium. The leakage of its contents into the subarachnoid space gives rise to meningismus. We report an extremely rare phenomenon of an intraventricular rupture of a cystic craniopharyngioma,

Vaijayantee Kulkarni; Roy Thomas Daniel; Ramachandra Pranatartiharan

2000-01-01

115

Rupture Velocity of Plane Strain Shear Cracks  

Microsoft Academic Search

Propagation of plane strain shear cracks is calculated numerically by using finite difference equations with second-order accuracy. The rupture model, in which stress drops gradually as slip increases, combines two different rupture criteria: (1) slip begins at a finite stress level; (2) finite energy is absorbed per unit area as the crack advances. Solutions for this model are nonsingular. In

D. J. Andrews

1976-01-01

116

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

NASA Astrophysics Data System (ADS)

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.

Xu, Chong

2014-07-01

117

Transverse instability of dunes  

E-print Network

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

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

2011-09-22

118

Cryogenic insulation strength and bond tester  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

119

Transverse freezing of thin liquid films  

NASA Astrophysics Data System (ADS)

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

Beerman, Michael

120

Probabilistic simulation of uncertainties in composite uniaxial strengths  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

121

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

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

122

Spaghetti Strength  

NSDL National Science Digital Library

In this activity on page 7 of the PDF, learners explore how engineers characterize building materials. Learners test the strength of spaghetti and determine how the number of spaghetti strands affects the strength of a bundle of spaghetti. Use this activity to chemical bonds, mechanical testing, and engineering. Note: The pasta strands can be dipped in water and stuck together to more closely mimic the layers within a piece of plywood. More information about this can be found at the top of page 7, directly underneath the cartoon image. Safety note: Do not eat or drink any of the materials in this activity.

American Chemical Society

2011-01-01

123

Test of Insulation Electrical Strength of LARP Technological Quadrupoles (TQ)  

Microsoft Academic Search

This is a report about measuring the Insulation Electrical Strength of a TQC and a TQS practice coil. Tests were performed under transverse pressure up to 190 MPa at voltage up to 1000 V. Turn-to-turn insulation strength was measured between cables within the inner layer and within the outer layer. Layer-to-layer insulation strength was measured as well.

D. Tooke; G. Ambrosio; N. Andreev; R. Bossert

124

Extraneural rupture of intraneural ganglion cysts.  

PubMed

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. PMID:21838077

Shahid, Kameron R; H閎ert-Blouin, Marie-No雔le; Amrami, Kimberly K; Spinner, Robert J

2011-01-01

125

Metrics for comparing dynamic earthquake rupture simulations  

USGS Publications Warehouse

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 (?爏ee 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抯 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.

Barall, Michael; Harris, Ruth A.

2014-01-01

126

Age at intracranial aneurysm rupture among generations  

PubMed Central

Background: Previous studies have reported intracranial aneurysm (IA) occurring at young ages in subsequent generations. These studies did not correct for duration of follow-up. Second-generation members who would have their ruptured IA late in life may not be detected due to shorter follow-up time than the first generation. We examined families in which ruptured IA occurred in two consecutive generations for the hypothesis that the second generation (F1) was more likely to have a rupture at a younger age than the older generation (F0). Methods: The Familial Intracranial Aneurysm (FIA) Study is a multicenter, international study recruiting families of ruptured and unruptured IA. All available family members are interviewed. Cox proportional hazards regression models and Kaplan-Meier curves were used to examine differences by generation. Results: Although we found that the F1 generation was more likely to have an aneurysm rupture at a younger age than the F0 generation, we found that this was largely because of a lack of follow-up time in the F1 generation. The F1 generation had 50% the rupture rate of the prior generation. When analyzed by Kaplan-Meier curves, we found a tendency to have a slightly later rupture rate in the F1 generation once time to follow-up was included in the analysis model. Conclusions: Families of ruptured intracranial aneurysm (IA) do not appear to demonstrate 揳nticipation. Our finding suggests that genetic epidemiology of ruptured IA should examine all types of variations such as single base-pair changes, deletions, insertions, and other variations that do not demonstrate anticipation. GLOSSARY FIA = familial intracranial aneurysm; IA = intracranial aneurysm; SAH = subarachnoid hemorrhage. PMID:19237697

Woo, D; Hornung, R; Sauerbeck, L; Brown, R; Meissner, I; Huston, J; Foroud, T; Broderick, J

2009-01-01

127

Earthquake Rupturing in Fluid-Overpressured Crust: How Common?  

NASA Astrophysics Data System (ADS)

Whether or not ruptures nucleate in fluid-overpressured crust ( ? v = P f/ ? v > 0.4) is important because pore-fluids overpressured above hydrostatic lower fault frictional strength and may also vary through the earthquake cycle, acting as an independent variable affecting fault failure. Containment of fluid overpressure is precarious because pressure-dependent activation of faults and fractures allows drainage from overpressured portions of the crust. Discharge of fluids through activated fault-fracture permeability (fault-valve action) decreases overpressure so that subsequent failure depends on the cycling of both overpressure and frictional strength as well as tectonic stress. Geometric and mechanical considerations suggest that fluid overpressures are more likely to develop and be sustained in compressional/transpressional regimes as opposed to extensional/transtensional tectonic settings. On the basis of geophysical observations and force-balance analyses, subduction interface shear zones appear to be strongly but variably overpressured to near-lithostatic levels ( ? v > 0.9) over the full depth range of seismogenic megathrusts. Strong overpressuring at seismogenic depths is also documented in active fold-thrust belts and in areas of ongoing compressional inversion (e.g., northern Honshu) where inherited normal faults are reactivated as steep reverse faults, requiring near-lithostatic overpressures ( ? v ? 1.0) at depths of rupture initiation. Evidence for overpressuring around strike-slip faults is less clear but tends to be strongest in areas of transpression. In areas of extensional tectonics coincident with particularly high fluid discharge, there is some evidence of overpressuring concentrated towards the base of the seismogenic zone. In general, because of the limited resolution of geophysical techniques, it is easier to make the case for rupture propagation through overpressured crust than to make a definitive case for the direct involvement of overpressured fluids in rupture nucleation, though in some instances the circumstantial evidence is compelling. An unresolved related issue is the heterogeneity of overpressuring. Do the active fault zones themselves serve as fluid conduits that are locally overpressured with respect to the surrounding crust?

Sibson, Richard H.

2014-11-01

128

Thyroid rupture secondary to blunt neck trauma.  

PubMed

Rupture of the thyroid gland is uncommon in cases of blunt neck trauma. We report a case of thyroid rupture after a motor vehicle accident in a patient without a preexisting goiter. He presented with a painful anterior neck swelling associated with dysphagia and hoarseness of voice. Computed tomographic scans showed lacerations of the right thyroid lobe and isthmus with features suggestive of slow active bleeding. Neck exploration was subsequently performed, and a ruptured right thyroid lobe was found with ongoing venous hemorrhage. A right hemithyroidectomy was performed, and the patient recovered without complications. PMID:23399341

Sow, Yih-Liang; Aziz, Nora Abdul; Ng, Khoon-Leong

2013-04-01

129

CT diagnosis of ruptured abdominal aortic aneurysm  

SciTech Connect

Abdominal computed tomography was performed in six patients with suspected ruptured abdominal aortic aneurysm but in whom an alternate clinical diagnosis was seriously considered. In each patient, a large aortic aneurysm was demonstrated in association with a retroperitoneal accumulation of high-density blood. The retroperitoneal blood was primarily confined to the extracapsular perinephric space. In four of the six patients, a focal area of the aortic wall was indistinct on the side of the retroperitoneal hemorrhage at the presumed site of rupture. Five of the six patients underwent emergency surgery, which confirmed the site of aneurysm, presence of rupture and the location of fresh retroperitoneal blood.

Rosen, A.; Korobkin, M.; Silverman, P.M.; Moore, A.V. Jr.; Dunnick, N.R.

1984-08-01

130

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

NASA Astrophysics Data System (ADS)

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, and friction recovery. We discuss the significant contribution of this experimentally-based friction model to the understanding of rupture models with emphasis on slip-pulse behavior.

Liao, Zonghu; Reches, Zeev

2013-04-01

131

Progression of abdominal aortic aneurysm towards rupture: refining clinical risk assessment using a fully coupled fluid-structure interaction method.  

PubMed

Rupture of abdominal aortic aneurysm (AAA) is associated with high mortality rates. Risk of rupture is multi-factorial involving AAA geometric configuration, vessel tortuosity, and the presence of intraluminal pathology. Fluid structure interaction (FSI) simulations were conducted in patient based computed tomography scans reconstructed geometries in order to monitor aneurysmal disease progression from normal aortas to non-ruptured and contained ruptured AAA (rAAA), and the AAA risk of rupture was assessed. Three groups of 8 subjects each were studied: 8 normal and 16 pathological (8 non-ruptured and 8 rAAA). The AAA anatomical structures segmented included the blood lumen, intraluminal thrombus (ILT), vessel wall, and embedded calcifications. The vessel wall was described with anisotropic material model that was matched to experimental measurements of AAA tissue specimens. A statistical model for estimating the local wall strength distribution was employed to generate a map of a rupture potential index (RPI), representing the ratio between the local stress and local strength distribution. The FSI simulations followed a clear trend of increasing wall stresses from normal to pathological cases. The maximal stresses were observed in the areas where the ILT was not present, indicating a potential protective effect of the ILT. Statistically significant differences were observed between the peak systolic stress and the peak stress at the mean arterial pressure between the three groups. For the ruptured aneurysms, where the geometry of intact aneurysm was reconstructed, results of the FSI simulations clearly depicted maximum wall stress at the a priori known location of rupture. The RPI mapping indicated several distinct regions of high RPI coinciding with the actual location of rupture. The FSI methodology demonstrates that the aneurysmal disease can be described by numerical simulations, as indicated by a clear trend of increasing aortic wall stresses in the studied groups, (normal aortas, AAAs and rAAAs). Ultimately, the results demonstrate that FSI wall stress mapping and RPI can be used as a tool for predicting the potential rupture of an AAA by predicting the actual rupture location, complementing current clinical practice by offering a predictive diagnostic tool for deciding whether to intervene surgically or spare the patient from an unnecessary risky operation. PMID:25527320

Xenos, Michalis; Labropoulos, Nicos; Rambhia, Suraj; Alemu, Yared; Einav, Shmuel; Tassiopoulos, Apostolos; Sakalihasan, Natzi; Bluestein, Danny

2015-01-01

132

Repair of pectoralis major ruptures: single-surgeon case series.  

PubMed

Rupture of the pectoralis major is an uncommon injury that can lead to pain, loss of strength, and cosmetic deformity. The purpose of this study was to analyze the outcome of pectoralis major repairs by a single surgeon. Twenty-four patients who underwent pectoralis major repair by the senior author (M.D.L.) between May 2005 and March 2011 were retrospectively identified. Patients were assessed at least 6 months postoperatively with the use of various questionnaires, including the Penn Shoulder Score, American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form, and Single Assessment Numeric Evaluation (SANE). All patients were men with an injury to the sternal head of the pectoralis. Most (16/24; 67%) patients sustained the injury while bench or incline bench pressing. Nineteen (79%) patients were successfully contacted for follow-up. Of these, an average preinjury bench press of 318 lb (range, 145-525 lb) was restored to an average of 264 lb (range, 100-500 lb) at follow-up. Average preoperative Penn Shoulder Score was 60 points (range, 33-77 points), improving to 94 points (range, 64-100 points) at last follow-up (P=.011). Average postoperative ASES and SANE scores were 96 points (range, 60-100 points) and 93 points (range, 50-100 points), respectively. All but 1 patient were rated excellent (14/19; 74%) or good (4/19; 21%) by the Bak criteria. Operative treatment of pectoralis major rupture yields high patient satisfaction and allows predictable return of comfort, range of motion, cosmesis, and overall limb strength, with a slightly less predictable return of maximum bench press strength. PMID:22868603

Garrigues, Grant E; Kraeutler, Matthew J; Gillespie, Robert J; O'Brien, Daniel F; Lazarus, Mark D

2012-08-01

133

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

NASA Technical Reports Server (NTRS)

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.

Yun, Hee Mann; Titran, Robert H.

1993-01-01

134

Plantaris rupture: why is it important?  

PubMed Central

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. PMID:23345486

Rohilla, Seema; Jain, Nitin; Yadav, Rohtas

2013-01-01

135

Acute Iliac Artery Rupture: Endovascular Treatment  

SciTech Connect

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.

Chatziioannou, A.; Mourikis, D.; Katsimilis, J.; Skiadas, V., E-mail: bill_skiadas@yahoo.gr; Koutoulidis, V.; Katsenis, K.; Vlahos, L. [University of Athens, Radiology Department, Areteion Hospital (Greece)

2007-04-15

136

Effect of shear rupture on aggregate scale formation in sea ice  

NASA Astrophysics Data System (ADS)

A discrete element model is used to study shear rupture of sea ice under convergent wind stresses. The model includes compressive, tensile, and shear rupture of viscous elastic joints connecting floes that move under the action of the wind stresses. The adopted shear rupture is governed by Coulomb's criterion. The ice pack is a 400 km long square domain consisting of 4 km size floes. In the standard case with tensile strength 10 times smaller than the compressive strength, under uniaxial compression the failure regime is mainly shear rupture with the most probable scenario corresponding to that with the minimum failure work. The orientation of cracks delineating formed aggregates is bimodal with the peaks around the angles given by the wing crack theory determining diamond-shaped blocks. The ice block (floe aggregate) size decreases as the wind stress gradient increases since the elastic strain energy grows faster leading to a higher speed of crack propagation. As the tensile strength grows, shear rupture becomes harder to attain and compressive failure becomes equally important leading to elongation of blocks perpendicular to the compression direction and the blocks grow larger. In the standard case, as the wind stress confinement ratio increases the failure mode changes at a confinement ratio within 0.2-0.4, which corresponds to the analytical critical confinement ratio of 0.32. Below this value, the cracks are bimodal delineating diamond shape aggregates, while above this value failure becomes isotropic and is determined by small-scale stress anomalies due to irregularities in floe shape.

Wilchinsky, Alexander V.; Feltham, Daniel L.; Hopkins, Mark A.

2010-10-01

137

Dynamical modeling of earthquake rupture based on the 1D Burridge-Knopoff spring-block model with rate-and-state friction  

NASA Astrophysics Data System (ADS)

We investigate the rupture processes along a one-dimensional fault by means of the Burridge-Knopoff spring-block model with rate-and-state friction. An external driving force is given to trigger the motions of the system for simulating earthquake ruptures. Two parameters, i.e., the spring stiffness and the maximum fault strength (or the breaking strength), control the ruptures. Simulation results show that there is not a clear relation between the driving force and the duration of ruptures. However, a smaller driving force might cause re-ruptures at a block after it moved through the steady state due to low dissipation of energy. A larger spring stiffness will magnify the driving force and cause larger stresses on other blocks and thus trigger the ruptures on other blocks in a shorter time than a small spring stiffness. High fault strengths allow more transition of energy from one block to its adjacent ones. Therefore, the largest slip will not take place on the block to which we give the driving force. Conclusively, the spring stiffness and the fault strength play an important role in controlling the conservation of energy in the system.

Wu, Y.; Wang, J.; Chen, C.

2013-12-01

138

Dynamic rupture activation of backthrust fault branching  

NASA Astrophysics Data System (ADS)

We perform dynamic rupture simulations to investigate the possible reactivation of backthrust branches triggered by ruptures along a main thrust fault. Simulations with slip-weakening fault friction and uniform initial stress show that fast propagation speed or long propagation distance of the main rupture promotes reactivation of backthrust over a range of branch angles. The latter condition may occur separately from the former if rupture speed is limited by an increasing slip-weakening distance towards the junction direction. The results suggest a trade-off between the amplitude and duration of the dynamic stress near the main rupture front for backthrust reactivation. Termination of the main rupture by a barrier can provide enhanced loading amplitude and duration along a backthrust rooted near the barrier, facilitating its reactivation especially with a high frictional resistance. The free surface and depth-dependent initial stress can have several additional effects. The sign of the triggered motion along the backthrust can be reversed from thrust to normal if a deeply nucleated main rupture breaks the free surface, while it is preserved as thrust if the main rupture is terminated by a barrier at depth. The numerical results are discussed in relation to several recent megathrust earthquakes in Sumatra, Chile, and Japan, and related topics such as branch feedbacks to the main fault. The dynamic view on backthrust fault branching provided by the study fills a gap not covered by quasi-static models or observations. A specific examined case of antithetic fault branching may be useful for indicating a barrier-like behavior along the main fault.

Xu, Shiqing; Fukuyama, Eiichi; Ben-Zion, Yehuda; Ampuero, Jean-Paul

2015-03-01

139

Investigation of Stress Rupture Tested Neutron Irradiated Tantalum Alloys  

NASA Astrophysics Data System (ADS)

Irradiation of metals with high-energy particles produces nano-scale defects that act as obstacles to dislocation glide. This paper presents the effects of low-level neutron radiation on the stress rupture and microstructural properties of two tantalum alloys, Ta-10%W and Ta-8%W-2%Hf (T-111), which have been used to encapsulate radioactive fuel for space Radioisotope Power Systems (RPS). Ta-10%W and T-111 test specimens were exposed to a neutron fluence level (1.21015nvt) at temperatures less than <0.2 Tm, which is equivalent to the cumulative fluence associated with the 30-year mission life of a RPS. This fluence level results in an atomic displacement damage of approximately 3.010-7 dpa in both alloys. The atomic displacement damage produces an approximate two-order of magnitude increase in the stress rupture time, and a two-order of magnitude reduction in steady state creep rate. These observations are statistically significant at the 0.05 significance level. Transmission electron microscopy of rupture specimens reveals that the interaction of the irradiation produced defects with ao/2<111> screw dislocations results in a five-fold increase in dislocation density and a pronouncement of the ordering of dislocations into mosaic patterns of cellular or subgranular arrangements. The results of this research are significant because they provide a basic understanding of the strength mechanisms in two tantalum alloys (Ta-10%W and T-111) resulting from neutron irradiation at temperatures <0.2 Tm.

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

2008-01-01

140

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)

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.

Titran, R. H.

1984-01-01

141

Tensile stress rupture behavior of a woven ceramic matrix composite in humid environments at intermediate temperature  

NASA Astrophysics Data System (ADS)

This study focused on moisture and intermediate temperature effects on the embrittlement phenomenon and stress rupture life of the ceramic matrix composite (CMC) made of Sylramic(TM) fibers with an in-situ layer of boron nitride (Syl-iBN), boron nitride interphase (BN), and SiC matrix (Syl-iBN/BN/SiC). Stress rupture tests were performed at 550癈 or 750癈 with moisture contents of 0.0, 0.2, or 0.6 atm partial pressure of water vapor, pH 2O. The CMC stress rupture strengths at 100 hrs at 550癈 with 0.0, 0.2, or 0.6 atm pH2O were 75%, 65% and 51% of the monotonic room temperature tensile strength, respectively. At 750癈, the corresponding strengths were 67%, 51%, and 49%, respectively. Field Emission Scanning Electron Microscopy (FESEM) analysis showed that the amount of pesting by glass formations increased with time, temperature, and pH2O leading to embrittlement. Total embrittlement times for 550癈 were estimated to be greater than 63 hrs for 0.0 atm pH2O greater than 38 hrs for 0.2 atm pH 2O and between 8 and 71 hrs for 0.6 atm pH2O. Corresponding estimated embrittlement times for the 750癈 were greater than 83 hrs, between 13 and 71 hrs, and between 1 and 6 hrs. A time-dependent, phenomenological, Monte Carlo-type simulation of composite failure was developed. The simulated total embrittlement times for the 550癈 cases were 300 hrs, 100 hrs, and 25 hrs for 0.0, 0.2, and 0.6 atm pH 2O, respectively. The corresponding embrittlement times for the 750癈 cases were 300 hrs, 20 hrs, and 3 hrs. A detailed sensitivity analysis on the variables used in the model was conducted. The model was most sensitive to variation in the ultimate strength of the CMC at room temperature, the ultimate strength of the CMC at elevated temperature, and the reference strength of a fiber and it was least sensitive to variation in the modulus of elasticity of the matrix and fiber. The sensitivity analysis showed that the stress ruptures curves generated by variation in the total embrittlement time simulate the trends in the experimental data. This research showed that the degree of stress rupture strength degradation increases with temperature, moisture content level, and exposure time.

Larochelle, Kevin J.

142

Parallel Lines and Transversals  

NSDL National Science Digital Library

In this lab you will review the names of angles formed by transversals. In addition you will discover the unique relationship that these pairs of anlges have when the transversal cuts through two parallel lines. picture We have already discussed many angle relationships in class. For example, we have learned to identify vertical angles and linear pairs. Each of the angles have a special relationship. Vertical angles are congruent, and Linear angles are supplementary. In the following lesson you will review the names of angle pairs ...

Mrs. Sonntag

2010-10-07

143

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

USGS Publications Warehouse

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.

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

2012-01-01

144

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

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

145

Deconstructed Transverse Mass Variables  

E-print Network

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

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

2014-09-09

146

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

147

Creep-rupture tests of internally pressurized Hastelloy-X tubes  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

148

General Considerations of Ruptured Abdominal Aortic Aneurysm: Ruptured Abdominal Aortic Aneurysm  

PubMed Central

Although development of surgical technique and critical care, ruptured abdominal aortic aneurysm still carries a high mortality. In order to obtain good results, various efforts have been attempted. This paper reviews initial management of ruptured abdominal aortic aneurysm and discuss the key point open surgical repair and endovascular aneurysm repair. PMID:25705591

Lee, Chung Won; Bae, Miju; Chung, Sung Woon

2015-01-01

149

Rupture progression along discontinuous oblique fault sets: implications for the Karadere rupture segment of the 1999 Izmit earthquake, and future rupture in the Sea of Marmara  

Microsoft Academic Search

Large earthquakes in strike-slip regimes commonly rupture fault segments that are oblique to each other in both strike and dip. This was the case during the 1999 Izmit earthquake, which mainly ruptured E朩-striking right-lateral faults but also ruptured the N60癊-striking Karadere fault at the eastern end of the main rupture. It will also likely be so for any future large

Jordan R. Muller; Atilla Aydin

2004-01-01

150

Thermal regime from bottom simulating reflectors along the N Ecuador - S Colombia margin: relation between tectonic segmentation, thermal variation and the limit of the seismic rupture zones  

Microsoft Academic Search

In the North Ecuador South Columbian (NESC) convergent margin (0癗) three megathrust events, in 1942, 1958 and 1979, present rupture zones that abut one another. Multichannel seismic (MCS) reflection and bathymetric data acquired during the SISTEUR (2000) and AMADEUS (2005) cruises highlighted that the margin comprises four transverse segments (called, from south to north, the Esmeraldas, Manglares, Tumaco and Patia

B. Marcaillou; G. Spence; J. Collot; K. Wang; A. Ribodetti

2005-01-01

151

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

NASA Astrophysics Data System (ADS)

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 propagation.

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

2015-02-01

152

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

NASA Astrophysics Data System (ADS)

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

Hirauchi, Ken-ichi; Muto, Jun

2015-12-01

153

Hitherto unknown shear rupture mechanism as a source of instability in intact hard rocks at highly confined compression  

NASA Astrophysics Data System (ADS)

Today, frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength for confined conditions corresponding to the seismogenic layer. This paper 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. In the new mechanism, the rock failure associated with consecutive creation of small slabs (known as 慸omino-blocks') from the intact rock in the rupture tip is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance, self-sustaining stress intensification, and self-unbalancing conditions. Due to this the failure process caused by the mechanism is very dynamic and violent. This makes it impossible to directly observe and study the mechanism and can explain why the mechanism has not been detected before. This paper provides physical motivation for the mechanism, based upon side effects accompanying the failure process. Physical and mathematical models of the mechanism presented in the paper explain unique and paradoxical features of the mechanism. The new shear rupture mechanism allows a novel point of view for understanding the nature of spontaneous failure processes in hard rocks including earthquakes.

Tarasov, Boris G.

2014-05-01

154

Acoustic levels of heavy truck tire ruptures.  

PubMed

Transportation vehicles, whether they are passenger vehicles or heavy trucks and transport vehicles, rely upon rubber tires to negotiate the roadways and surfaces on which they are driven. These tires have the potential of sudden rupture resulting from various causes including but not limited to over-pressurization, sidewall failures, or punctures from roadway debris. These rupture events can and do occur while the vehicles are stationary (e.g., during servicing) or are being driven, and often occur without notice. While the phenomenon of sudden tire failure has been documented for several decades, the potential bodily injury which can occur when an individual is in close proximity to such a sudden rupture has only more recently been documented. Aside from anecdotal mention in case studies, there has been little quantitative information available on the acoustic levels during these failures. Our study provides measured acoustic levels as a function of distance for such catastrophic tire failures. PMID:23622472

Wood, Matthew; Woodruff, William

2013-05-01

155

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)

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 estimated the rupture velocity as well as rupture velocity changes distribution across the fault plane based on the procedure proposed by PD09. Our results show that rupture velocity has strong variations concentrated in small patches within large slip areas (asperities). Using this dynamic model we performed the strong motion simulation at the IWTH25 borehole. We obtained that this model is able to reproduce the two HF events observed in the strong motion data. Our preliminary results suggest that the extreme acceleration pulses were induced by two strong rupture velocity acceleration events at the rupture front. References Aoi, S., T. Kunugi, and H. Fujiwara, 2008, Science, 322, 727-730. Ely, G. P., S. M. Day, and J.-B. Minster (2009), Geophys. J. Int., 177(3), 1140-1150. Pulido, N., S. Aoi, and W. Suzuki (2008), AGU Fall meeting, S33C-02. Pulido, N., and L.A. Dalguer, (2009). Estimation of the high-frequency radiation of the 2000 Tottori (Japan) earthquake based on a dynamic model of fault rupture: Application to the strong ground motion simulation, Bull. Seism. Soc. Am. 99(4), 2305-2322. Suzuki, W., S. Aoi, and H. Sekiguchi, (2009), Bull. Seism. Soc. Am. (Accepted).

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

2009-12-01

156

[Ettore Majoran's transversal epistemology].  

PubMed

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

Bontems, Vincent

2013-01-01

157

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

158

Consequences of expansion joint bellows rupture  

SciTech Connect

Expansion joints are used in piping systems to accommodate pipe deflections during service and to facilitate fitup. Typically, the expansion joint bellows is the thinnest part of the pressure boundary, bellows rupture frequencies are typically several orders of magnitude higher than pipe rupture frequencies. This paper reviews an effort to estimate the flow rates associated with bellows rupture. The Level I PRA (probabilistic risk assessment) for the Savannah River Site production reactors made the bounding assumption that bellows rupture would produce the maximum possible leakage - that of a double-ended guillotine break (DEGB). This assumption resulted in predictions of flooding of the reactor building with a high conditional probability that a Loss of Pumping Accident and core melting would follow. This paper describes analyses that were performed to develop a realistic break area and leak rate resulting from bellows rupture and therefore reduce the impact that bellows rupture can have on the estimated total core melt frequency. In the event of a 360 degree circumferential break of the bellows the resulting two sections will separate to the point where the force from the internal pressure acting to push the bellows open is just balanced by the spring force of the bellows itself. For the bellows addressed in this analysis, the equilibrium separation distance is 0.7 inches with normal pump lineup. The opening area is influenced by any initial compression or extension due to installation alignment, and by any operational displacements such as thermal expansion of the adjoining pipe. The influence of such factors is considered and the impact on the flooding rate and, hence, core melt frequency is reviewed.

Daugherty, W.L.; Miller, R.F.; Cramer, D.S.

1992-11-01

159

Consequences of expansion joint bellows rupture  

SciTech Connect

Expansion joints are used in piping systems to accommodate pipe deflections during service and to facilitate fitup. Typically, the expansion joint bellows is the thinnest part of the pressure boundary, bellows rupture frequencies are typically several orders of magnitude higher than pipe rupture frequencies. This paper reviews an effort to estimate the flow rates associated with bellows rupture. The Level I PRA (probabilistic risk assessment) for the Savannah River Site production reactors made the bounding assumption that bellows rupture would produce the maximum possible leakage - that of a double-ended guillotine break (DEGB). This assumption resulted in predictions of flooding of the reactor building with a high conditional probability that a Loss of Pumping Accident and core melting would follow. This paper describes analyses that were performed to develop a realistic break area and leak rate resulting from bellows rupture and therefore reduce the impact that bellows rupture can have on the estimated total core melt frequency. In the event of a 360 degree circumferential break of the bellows the resulting two sections will separate to the point where the force from the internal pressure acting to push the bellows open is just balanced by the spring force of the bellows itself. For the bellows addressed in this analysis, the equilibrium separation distance is 0.7 inches with normal pump lineup. The opening area is influenced by any initial compression or extension due to installation alignment, and by any operational displacements such as thermal expansion of the adjoining pipe. The influence of such factors is considered and the impact on the flooding rate and, hence, core melt frequency is reviewed.

Daugherty, W.L.; Miller, R.F.; Cramer, D.S.

1992-01-01

160

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

NASA Technical Reports Server (NTRS)

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.

Yun, Hee Mann; DiCarlo, James A.

1997-01-01

161

The effect of transient overloads on the stress-rupture of glass fibre reinforced polymers  

NASA Astrophysics Data System (ADS)

Power station cooling water (CW) system components may be subject to water hammer events during their thirty year service life. The immediate and long term effects of such events on glass fibre reinforced polymer (GFRP) structures were hitherto unknown. This study investigates these effects and considers how well design codes address the problem of water hammer. A sequence of model water hammer events were applied to coupons of glass reinforced polyester and vinyl ester laminates ("overloaded" coupons). Damage studies revealed transverse resin cracking but no fibre fractures. The effect of stress/time profile on damage was investigated. CW systems operating from a constant head reservoir were modelled by stress-rupture tests in an aqueous environment at 40 C. Stress-rupture lifetime of overloaded coupons was found to be reduced in comparison to virgin coupons. CW systems operating from a coastal reservoir were simulated by applying a sinusoidal load regime, with an R-ratio of 0.67, at a frequency of 23.15 Hz, to overloaded coupons in an aqueous environment at 40 C. The results were then compared with those from the stress-rupture tests. Genuine water hammer events were also applied to a model component. Glass reinforced polyester pipes of 151mm diameter were subjected to ten water hammer events of the type occurring in a CW system ("overloaded" pipes). Axial cracking resulted. Stress-rupture testing was carried out on virgin and overloaded pipes in an aqueous environment at 40 C. The lifetime of overloaded pipes was reduced in comparison to virgin pipes. This was attributed to enhanced stress-corrosion cracking at sites of water hammer induced cracking.Stress-rupture results for material tested in pipe and coupon form were compared. At a given stress level, longer lifetimes were exhibited by pipe material. This indicated that designing from coupon data might lead to costly overdesign. Design codes were then reviewed in the light of the above experimental results.

Rawles, J. D.

1990-01-01

162

Shock wave theory for rupture of rubber  

E-print Network

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

M. Marder

2004-07-09

163

Thoracic Outlet Syndrome Following Breast Implant Rupture  

PubMed Central

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

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

2015-01-01

164

Biomechanics of the craniocervical region: the alar and transverse ligaments.  

PubMed

In the treatment of spine fractures and fracture-dislocations, stability of the spine is one of the major objectives. In the craniocervical joint, the alar and transverse ligaments provide much of the stability of the healthy spine. Because the anatomy appears well described, the contribution of each of these structures so far has received little attention. The alar ligament restrains rotation of the upper cervical spine, whereas the transverse ligament restricts flexion as well as anterior displacement of the atlas. A lesion in one or both structures can produce damage to the neural structures and/or cause pain. To investigate the possible role of each of these ligaments, a mechanical and histologic study of the upper cervical spine was made. The bone-ligament-bone complex of the alar and transverse ligaments was subjected to uniaxial mechanical testing in seven specimens. The alar ligaments had an in vitro strength of 200 N, and the transverse ligaments had an in vitro strength of 350 N. Histologic analysis revealed a mainly collagenous nature of these ligaments. Clinical evidence (broken odontoid processes) suggests that the transverse ligament is strong enough to withstand physiologic loads. The alar ligament, on the other hand, due to its lower strength and its axial direction of loading, might be prone to injury and therefore require stabilization of the appropriate vertebra more often than normally is assumed. PMID:3357093

Dvorak, J; Schneider, E; Saldinger, P; Rahn, B

1988-01-01

165

Ideas in transverse spin physics  

E-print Network

Three simple ideas about transverse spin observables are presented for the purpose of stimulating discussion. The manuscript is based on a presentation at the "Transversity 2014" workshop in Torre Chia, Sardinia, Italy on June 9-13, 2014 where approximately sixty experts on transverse spin physics had gathered to share recent results in an atmosphere of sun-drenched intensity.

Dennis Sivers

2014-09-08

166

Ideas in Transverse Spin Physics  

NASA Astrophysics Data System (ADS)

Three simple ideas about transverse spin observables are presented for the purpose of stimulating discussion. The manuscript is based on a presentation at the Transversity 2014 Workshop in Torre Chia, Sardinia, Italy on June 9-13, 2014 where approximately sixty experts on transverse spin physics had gathered to share recent results in an atmosphere of sun-drenched intensity.

Sivers, Dennis

2015-01-01

167

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

NASA Technical Reports Server (NTRS)

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.

Dozier, Jan D.; Hackett, Robert M.

1987-01-01

168

Transversely coupled fiber Fabry-Perot resonator - Theory  

Microsoft Academic Search

The theory of output intensities and field strengths of two variants of a four-port fiber-based device called a transversely coupled fiber Fabry-Perot interferometer is presented. The analysis is sufficiently general to consider both input and output from all four arms in both variants. Finesse is calculated for all modes of operation.

Paul Urquhart

1987-01-01

169

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

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

170

Linker Dependent Bond Rupture Force Measurements in Single-Molecule Junctions  

SciTech Connect

We use a modified conducting atomic force microscope to simultaneously probe the conductance of a single-molecule junction and the force required to rupture the junction formed by alkanes terminated with four different chemical link groups which vary in binding strength and mechanism to the gold electrodes. Molecular junctions with amine, methylsulfide, and diphenylphosphine terminated molecules show clear conductance signatures and rupture at a force that is significantly smaller than the measured 1.4 nN force required to rupture the single-atomic gold contact. In contrast, measurements with a thiol terminated alkane which can bind covalently to the gold electrode show conductance and force features unlike those of the other molecules studied. Specifically, the strong Au-S bond can cause structural rearrangements in the electrodes, which are accompanied by substantial conductance changes. Despite the strong Au-S bond and the evidence for disruption of the Au structure, the experiments show that on average these junctions also rupture at a smaller force than that measured for pristine single-atom gold contacts.

Frei M.; Hybertsen M.; Aradhya S.V.; Venkataraman L.

2012-02-16

171

Earthquake Early Warning and the Physics of Earthquake Rupture  

E-print Network

mapping or other) data, and (c) inversions incorporating both seismic andseismic, teleseismic, trilateration, leveling, GPS, InSAR, surface rupture mapping,rupture mapping and other data. In other words, 搒eismic

Wurman, Gilead

2010-01-01

172

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

173

Creep rupture of the joint of a solid oxide fuel cell glass-ceramic sealant with metallic interconnect  

NASA Astrophysics Data System (ADS)

Creep properties of sandwich joint specimens made of a newly developed BaO-B2O3-Al2O3-SiO2 glass-ceramic sealant (GC-9) and a ferritic-stainless-steel interconnect (Crofer 22 H) for planar solid oxide fuel cells (pSOFCs) are investigated at 800牥C under constant shear and tensile loadings. The creep rupture time of Crofer 22 H/GC-9/Crofer 22 H joint specimens is increased with a decrease in applied load for both shear and tensile loading modes. The given metal/sealant/metal joint has a greater degradation of joint strength at 800牥C under prolonged, constant tensile loading as compared to shear loading. The tensile creep strength at a rupture time of 1000爃 is about 9% of the average tensile joint strength, while the shear creep strength at 1000爃 is about 23% of the average shear joint strength. Failure patterns of both shear and tensile joint specimens are similar regardless of the creep rupture time. In general, creep cracks initiate at the interface between the (Cr,Mn)3O4 spinel layer and the BaCrO4 chromate layer, penetrate through the BaCrO4 layer, and propagate along the interface between the chromate layer and glass-ceramic substrate until final fracture. Final, fast fracture occasionally takes place within the glass-ceramic layer.

Lin, Chih-Kuang; Lin, Kun-Liang; Yeh, Jing-Hong; Wu, Si-Han; Lee, Ruey-Yi

2014-01-01

174

Neutron Transversity at Jefferson Lab  

SciTech Connect

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.

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

2005-09-07

175

Progress in the treatment of ruptured abdominal aortic aneurysm  

Microsoft Academic Search

This report summarizes the clinical, pathological, and surgical aspects of ruptured abdominal aortic aneurysm. The significant\\u000a risk of rupture of these aneurysms is well documented. Although large aneurysms are more prone to rupture, the risk of rupture\\u000a of small aneurysms less than 4 cm in diameter is well established. While most aneurysms are a result of atherosclerosis, a\\u000a small number

Gerald M. Lawrie; E. Stanley Crawford; George C. Morris; Jimmy F. Howell

1980-01-01

176

Star polymers rupture induced by constant forces.  

PubMed

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. PMID:25362341

Garc韆, N A; Febbo, M; Vega, D A; Milchev, A

2014-10-28

177

Surgical Resection of Ruptured Fibrolamellar Hepatocellular Carcinoma  

PubMed Central

Fibrolamellar hepatocellular carcinoma (FLH) is a rare primary tumor of the liver, which typically arises from noncirrhotic livers and affects patients below the age of 35. We report on a 29-year-old male patient who presented with a ruptured FLH and was treated with surgical resection. Options for treatment and review of the management are described. PMID:23956918

Minutolo, Vincenzo; Licciardello, Alessio; Arena, Manuel; Minutolo, Orazio; Lanteri, Raffaele; Arena, Goffredo

2013-01-01

178

Laparoscopic splenectomy for atraumatic splenic rupture.  

PubMed

A traumatic splenic rupture (ASR) is a rare clinical entity. Several underlying benign and malignant conditions have been described as a leading cause. We report on a case of ASR in a 41-year-old man treated with laparoscopic splenectomy. Considering ASR as a life-threatening condition, a prompt diagnosis can be life saving. PMID:21675627

Grossi, Ugo; Crucitti, Antonio; D'Amato, Gerardo; Mazzari, Andrea; Tomaiuolo, Pasquina M C; Cavicchioni, Camillo; Bellantone, Rocco

2011-01-01

179

Surface Rupture in Northwest Saudi Arabia  

USGS Multimedia Gallery

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

180

What Is an Earthquake?: Rupture Models  

NSDL National Science Digital Library

In this activity, the learner will watch three animations based on actual data from fault ruptures from the two largest Southern California earthquakes in the 1990s: Landers (1992) and Northridge (1994). In Section 3, the learner will discover more about how such data is collected and analyzed.

181

Entangled transverse optical vortex.  

PubMed

We discuss a new kind of optical vortex with the angular momentum perpendicular to the flow direction and entangled in that it is a coherent combination of different orbital angular momentum states of the same sign. This entangled state exhibits many unexpected physical properties. The transverse optical vortex can be generated from the reflection of an electromagnetic wave off an array of ferrite rods. Its vorticity can be reversed by switching the direction of the magnetization of the rods, which usually takes only a nanosecond. PMID:25360971

Chui, S T; Lin, Zhifang

2014-10-01

182

Transverse field focused system  

DOEpatents

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.

Anderson, Oscar A. (Berkeley, CA)

1986-01-01

183

Intrinsic Transverse Size Effect  

E-print Network

Two recently proposed concepts to improve the perturbative calculation of exclusive amplitudes, gluonic radiative corrections (Sudakov factor) and confinement size effects (intrinsic transverse momentum) are combined to study the neutron magnetic form factor in the space-like region. We find that nucleon distribution amplitudes modelled on the basis of current QCD sum rules indicate overlap with the existing data at the highest measured values of momentum transfer. However, sizeable higher-order perturbative corrections (K-factor) and/or higher-twist contributions cannot be excluded, although they may be weaker than in the proton case.

J. Bolz; R. Jakob; P. Kroll; M. Bergmann; N. G. Stefanis

1994-07-11

184

Rupture Zones of Large South American Earthquakes and Some Predictions  

Microsoft Academic Search

This study attempts to forecast likely locations for large shallow South American earthquakes in the near future by examining the past space-time pattern of occurrence of large (M _ 7.7) earthquakes, the lateral extent of their rupture zones, and, where possible, the direction of rupture propagation. Rupture zones of large shallow earthquakes generally abut and do not overlap. Patterns of

John A. Kelleher

1972-01-01

185

Ruptured rectal duplication with urogenital abnormality: Unusual presentation  

PubMed Central

Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD. PMID:25552833

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

2015-01-01

186

Finite element modelling simulation of transverse welding phenomenon in aluminium extrusion process  

Microsoft Academic Search

Transverse welds occur in the billet-to-billet extrusion process, which is often used in modern aluminium extrusion plants for the purpose of continuous production. The transverse weld introduces a discontinuity at the weld interface in the extruded product and in many structural applications. This is not acceptable because it can severely reduce the strength and is detrimental to the quality of

Qiang Li; Chris Harris; Mark R. Jolly

2003-01-01

187

Creep and rupture of an ods alloy with high stress rupture ductility  

Microsoft Academic Search

The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by ?? precipitates, was studied at 760 癈 and 1093\\u000a 癈. At both temperatures the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation\\u000a and reduction in area. Failure was transgranular, and different modes of failure were observed

Mona E. McAlarney; Richard M. Arons; Tim E. Howson; John K. Tien; Sanford Baranow

1982-01-01

188

Creep and rupture of an ods alloy with high stress rupture ductility  

Microsoft Academic Search

The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma' precipitates, was studied at 760 癈 and 1093 癈. At both temperatures the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed

Mona E. McAlarney; Richard M. Arons; Tim E. Howson; John K. Tien; Sanford Baranow

1982-01-01

189

Posterior communicating artery aneurysm rupture mimicking apoplexy  

PubMed Central

Background: Cerebral aneurysm rupture can lead to devastating neurological complications and present a complex problem to treat. We report a unique case of a ruptured posterior communicating artery (PCoA) aneurysm presenting with sudden and complete vision loss. Case Description: A 39-year-old man presented with the acute onset of severe headache and complete bilateral vision loss. The patient described headaches for several months prior to presentation. However, prior to the day of presentation, he had no visual disturbance. A CT angiogram (CTA) and magnetic resonance imaging (MRI) of the brain revealed a 1.6-cm, non-contrast enhancing suprasellar mass, eccentric to the left side, consistent with hemorrhagic mass. There was no obvious aneurysm or vascular malformation. The sella tursica was normal in appearance. The patient was taken for an immediate endoscopic endonasal transtuberculum approach for optic nerve decompression. Hematoma without an associated tumor was encountered and partially evacuated before aborting with resultant partial improvement in vision. A subsequent cerebral angiogram revealed an irregularly shaped, postero-laterally pointing, 2.5-mm left PCoA aneurysm. The patient was then taken for open clipping of the ruptured aneurysm. A large, fibrinous capsule was found over the superolateral aspect of the aneurysm. The ruptured aneurysm was secured with clips and the surrounding hematoma was evacuated. Conclusion: In the immediate postoperative period, the patient regained vision in the nasal field of his right eye. This case illustrates a unique presentation of a ruptured PCoA aneurysm, and thus must be considered in the differential diagnosis of a suprasellar hemorrhage resulting in visual loss in absence of a recognizable associated tumor. PMID:22145088

Bonfield, Christopher M.; Gardner, Paul A.

2011-01-01

190

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

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

191

Intermediate Temperature Strength Degradation in SiC/SiC Composites  

NASA Technical Reports Server (NTRS)

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'.

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

2001-01-01

192

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

NASA Astrophysics Data System (ADS)

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 癈 and 300 癈 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 癈 as Vf is increased from 13% to 37%. The tensile strength reached up to 1246 MPa at 20 癈 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 癈, 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 癈. 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 癈, while comparable at RT, although the SCS6 fiber has a higher strength than the Sigma fiber. Such a beneficial outcome of the Sigma fiber may be attributed to its smaller radius leading to a larger total interface area for a given fiber content. The fractographic images after tensile rupture and fiber push-out test manifested a solid interfacial bonding via the thin TiC film. The weakest site was identified to be the internal interface between the outer carbon coating and the inner SiC layer. Numerous voids were observed in the plastically ruptured matrix after tensile fracture. The density of the voids was larger at 300 癈 than RT. The distributed voids are the evidence of ductile damage affecting the plastic work of the composite.

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

2013-09-01

193

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

SciTech Connect

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.

Wu, H.F.

1987-01-01

194

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

PubMed Central

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

2013-01-01

195

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

PubMed

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

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

2014-01-01

196

Mixed Adenoneuroendocrine Carcinoma of the Colon Progressed Rapidly After Hepatic Rupture: Report of a Case  

PubMed Central

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

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

2014-01-01

197

SORD: A New Rupture Dynamics Modeling Code  

NASA Astrophysics Data System (ADS)

We report on our progress in validating our rupture dynamics modeling code, capable of dealing with nonplanar faults and surface topography. The method uses a "mimetic" approach to model spontaneous rupture on a fault within a 3D isotropic anelastic solid, wherein the equations of motion are approximated with a second order Support-Operator method on a logically rectangular mesh. Grid cells are not required to be parallelepipeds, however, so that non-rectangular meshes can be supported to model complex regions. However, for areas in the mesh which are in fact rectangular, the code uses a streamlined version of the algorithm that takes advantage of the simplifications of the operators in such areas. The fault itself is modeled using a double node technique, and the rheology on the fault surface is modeled through a slip-weakening, frictional, internal boundary condition. The Support Operator Rupture Dynamics (SORD) code, was prototyped in MATLAB, and all algorithms have been validated against known (including analytical solutions, eg Kostrov, 1964) solutions or previously validated solutions. This validation effort is conducted in the context of the SCEC Dynamic Rupture model validation effort led by R. Archuleta and R. Harris. Absorbing boundaries at the model edges are handled using the perfectly matched layers method (PML) (Olsen & Marcinkovich, 2003). PML is shown to work extremely well on rectangular meshes. We show that our implementation is also effective on non-rectangular meshes under the restriction that the boundary be planar. For validation of the model we use a variety of test cases using two types of meshes: a rectangular mesh and skewed mesh. The skewed mesh amplifies any biases caused by the Support-Operator method on non-rectangular elements. Wave propagation and absorbing boundaries are tested with a spherical wave source. Rupture dynamics on a planar fault are tested against (1) a Kostrov analytical solution, (2) data from foam rubber scale models, and (3) numerical results from other types rupture dynamics codes. We also test the case of a simple kinked fault that has a known analytical solution. SORD has now been ported to Fortran 95 for multi-processor execution, with parallelization implemented using MPI. This provides a modeling capability on large scale platforms such as the SDSC DataStar machine, the various Teragrid platforms, or the SCEC High-performance computing facility. We will report on progress in validating that version of the code.

Ely, G.; Minster, B.; Day, S.

2005-12-01

198

Earthquake ruptures modulated by waves in damaged fault zones  

NASA Astrophysics Data System (ADS)

Faults are usually surrounded by damaged zones of lower elastic moduli and seismic wave velocities than their host rocks. If the interface between the damaged rocks and host rocks is sharp enough, earthquakes happening inside the fault zone generate reflected waves and head waves, which can interact with earthquake ruptures and modulate rupture properties such as rupture speed, slip rate, and rise time. We find through 2-D dynamic rupture simulations the following: (1) Reflected waves can induce multiple slip pulses. The rise time of the primary pulse is controlled by fault zone properties, rather than by frictional properties. (2) Head waves can cause oscillations of rupture speed and, in a certain range of fault zone widths, a permanent transition to supershear rupture with speeds that would be unstable in homogeneous media. (3) Large attenuation smears the slip rate function and delays the initial acceleration of rupture speed but does not affect significantly the rise time or the period of rupture speed oscillations. (4) Fault zones cause a rotation of the background stress field and can induce plastic deformations on both extensional and compressional sides of the fault. The plastic deformations are accumulated both inside and outside the fault zone, which indicates a correlation between fault zone development and repeating ruptures. Spatially periodic patterns of plastic deformations are formed due to oscillating rupture speed, which may leave a permanent signature in the geological record. Our results indicate that damaged fault zones with sharp boundaries promote multiple slip pulses and supershear ruptures.

Huang, Yihe; Ampuero, Jean-Paul; Helmberger, Don V.

2014-04-01

199

Transverse Wobbling in 135Pr  

NASA Astrophysics Data System (ADS)

A pair of transverse wobbling bands is observed in the nucleus 135Pr . The wobbling is characterized by ? I =1 , E 2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model.

Matta, J. T.; Garg, U.; Li, W.; Frauendorf, S.; Ayangeakaa, A. D.; Patel, D.; Schlax, K. W.; Palit, R.; Saha, S.; Sethi, J.; Trivedi, T.; Ghugre, S. S.; Raut, R.; Sinha, A. K.; Janssens, R. V. F.; Zhu, S.; Carpenter, M. P.; Lauritsen, T.; Seweryniak, D.; Chiara, C. J.; Kondev, F. G.; Hartley, D. J.; Petrache, C. M.; Mukhopadhyay, S.; Lakshmi, D. Vijaya; Raju, M. Kumar; Madhusudhana Rao, P. V.; Tandel, S. K.; Ray, S.; D鰊au, F.

2015-02-01

200

Transverse geometry and physical observers  

E-print Network

It is proposed that the mathematical formalism that is most appropriate for the study of spatially non-integrable cosmological models is the transverse geometry of a one-dimensional foliation (congruence) defined by a physical observer. By that means, one can discuss the geometry of space, as viewed by that observer, without the necessity of introducing a complementary sub-bundle to the line bundle of the observer or a codimension-one foliation transverse to the foliation of the observer. The concept of groups of transverse isometries acting on such a spacetime and the relationship of transverse geometry to spacetime threadings (1+3 decompositions) is also discussed.

David Delphenich

2007-11-13

201

Early diagnosis and management of myocardial rupture.  

PubMed

Left ventricular free wall rupture is a catastrophic mechanical complication of myocardial infarction. We present an 82-year-old woman with an anterolateral ST segment elevation myocardial infarction treated with thrombolysis. Because of unexplained hypotension, echocardiography was performed and contrast (Definity; Lantheus Medical Imaging) was used to improve visualization. Findings included a small- to moderate-sized circumferential pericardial effusion without frank tamponade, however, there was significant intramyocardial tracking of the contrast into the epicardial space, localized to the mid to apical portion of the anterior septum, consistent with rupture or disruption of the wall segment. The patient was promptly taken to the operating room where fresh blood and clots were evacuated from the pericardial space with immediate hemodynamic improvement. The patient underwent successful surgical repair. PMID:25547556

Liu, Shuangbo; Glavinovic, Tamara; Tam, James W

2015-01-01

202

Transient gravity perturbations induced by earthquake rupture  

NASA Astrophysics Data System (ADS)

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

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

2015-06-01

203

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

SciTech Connect

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.

Ar Latin-Small-Letter-Dotless-I bas, Bilgin Kadri, E-mail: bilginaribas@hotmail.com; Dingil, Guerbuez [A.Y. Ankara Oncology Training and Research Hospital, Department of Radiology (Turkey); Koeroglu, Mert [Sueleyman Demirel University School of Medicine, Department of Radiology (Turkey); Uenguel, Uemit; Zaral Latin-Small-Letter-Dotless-I , Aliye Ceylan [A.Y. Ankara Oncology Training and Research Hospital, Department of Radiology (Turkey)

2011-02-15

204

Transversally confined, noncausal gluons  

NASA Astrophysics Data System (ADS)

A nonperturbative approach to the gluonic sector of four-dimensional QCD is defined, in which a gap equation is used to generate a mass scale M via dimensional transmutation in an arbitrary axial gauge, using a modification of Halpern's method of replacing conventional functional integration over gauge potentials by integration over equivalent field strengths. A consistency condition is used to show that, without further radiative corrections, the gluonic QCD system is apparently diaelectromagnetic against the insertion of color-electromagnetic fields when the spatial shape of the nonperturbative vacuum state is associated with tubes of color-electric or -magnetic flux. A final Gaussian approximation to the relevant functional integral over field strength leads to an extremely simple result of ``effective gluons'' propagating as ``free particles'' with a matrix-valued mass term, by means of a noncausal ``propagator'' that is effectively confined to the interior of a spatial tube, and that falls off with a large momentum k as [k2]-2. A non-Gaussian extension of this result for the effective gluon propagator (EGP) can be guessed. Either form of EGP may be used to compute a finite, gauge-invariant condensate which corresponds to color-electric flux inside and color-magnetic flux outside the tube, or vice versa. The introduction of quarks leads to a ``modified QED'' in an external, tadpole-generated field, where the EGP replaces the bare photon propagator.

Fried, H. M.

1992-12-01

205

Transversally confined, noncausal gluons  

SciTech Connect

A nonperturbative approach to the gluonic sector of four-dimensional QCD is defined, in which a gap equation is used to generate a mass scale [ital M] [ital via] dimensional transmutation in an arbitrary axial gauge, using a modification of Halpern's method of replacing conventional functional integration over gauge potentials by integration over equivalent field strengths. A consistency condition is used to show that, without further radiative corrections, the gluonic QCD system is apparently diaelectromagnetic against the insertion of color-electromagnetic fields when the spatial shape of the nonperturbative vacuum state is associated with tubes of color-electric or -magnetic flux. A final Gaussian approximation to the relevant functional integral over field strength leads to an extremely simple result of effective gluons'' propagating as free particles'' with a matrix-valued mass term, by means of a noncausal propagator'' that is effectively confined to the interior of a spatial tube, and that falls off with a large momentum [ital k] as [[ital k][sup 2

Fried, H.M. (Physique Theorique, Institut Nonlineaire de Nice, Universite de Nice, 06108 Nice CEDEX 2 (France))

1992-12-15

206

[Volvulus of the transverse colon].  

PubMed

A case of transverse colon volvulus is described. The authors illustrate the procedures adopted for diagnosing the condition, which are mainly radiological consisting in plain film of the abdomen and barium enema, where necessary. The treatment is invariably surgical: detorsion of the volvulus and colopexy, and resection of the transverse colon in the presence of ischaemic lesions or right hemicolectomy. PMID:3690776

Genoni, E; Bonzi, F; Bernieri, A; Boccazzi, G; Ciprandi, G

1987-08-01

207

Transverse Viscoelastic Extension in Nitella  

PubMed Central

Transverse viscoelastic extensibility was measured directly in isolated walls of Nitella internode cells. Cell walls extended transversely exhibit a yield point which is approximately twice the yield point in the longitudinal direction. Walls from young, growing cells are four to seven times more extensible longitudinally than transversely, while walls from mature, nongrowing cells are only two times more extensible longitudinally. Although longitudinal extensibility decreases drastically with the decrease in the growth rate, lateral extensibility is constant through development. There is a discrepancy between the lateral growth rate and transverse creep, since the lateral growth rate is not constant. However, the degree of wall anisotropy observed is consistent with the view that the transversely oriented cellulose microfibrils act as a 搑einforcing filler in Nitella cell walls. ImagesFig. 1 PMID:16660247

M閠raux, Jean-Pierre; Taiz, Lincoln

1978-01-01

208

Transverse spin observables in chromodynamics  

SciTech Connect

Quantum Chromodynamics confronts a harsh series of tests in the attempt to formulate a comprehensive approach to the calculation of transverse spin observables. The basic obstacles to understanding transverse spin can be illustrated by considering the transverse structure function g{sub T}(x, Q{sup 2}) = g{sub 1}(x, Q{sup 2}) + g{sub 2}(x, Q{sup 2}), extracted from deep-inelastic scattering using a polarized lepton and a polarized proton. The inadequacy of the transverse-spin basis for quarks and gluons found there suggests a new approach to the problems of single-spin observables in large-transverse-momentum processes. This approach, presented earlier for single spin production asymmetries, is discussed here. It is shown that the mechanism can also lead to baryon polarization effects at large P{sub T}. 14 refs.

Sivers, D.

1989-12-01

209

Time/temperature dependent tensile strength of SiC and Al{sub 2}O{sub 3}-based fibers  

SciTech Connect

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 Al{sub 2}O{sub 3}-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.

Yun, Hee Mann; DiCarlo, J.A. [NASA Lewis Research Center, Cleveland, OH (United States)

1996-12-31

210

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

211

Synergy and interactions among biological pathways leading to preterm premature rupture of membranes.  

PubMed

Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Impact of PPROM is greatest in low- and middle-income countries where prematurity-related deaths are most common. Recent investigations identify cytokine and matrix metalloproteinase activation, oxidative stress, and apoptosis as primary pathways to PPROM. These biological processes are initiated by heterogeneous etiologies including infection/inflammation, placental bleeding, uterine overdistention, and genetic polymorphisms. We hypothesize that pathways to PPROM overlap and act synergistically to weaken membranes. We focus our discussion on membrane composition and strength, pathways linking risk factors to membrane weakening, and future research directions to reduce the global burden of PPROM. PMID:24840939

Lannon, Sophia M R; Vanderhoeven, Jeroen P; Eschenbach, David A; Gravett, Michael G; Adams Waldorf, Kristina M

2014-10-01

212

Femoral pseudoaneurysm rupturing into urinary bladder: A rare presentation.  

PubMed

Femoral pseudoaneurysm is a common occurrence in intravenous drug abuser due to repeated trauma to the femoral artery causing arterial leak contained by the surrounding tissue and does not contain all the layers of arterial wall. Rupture of these aneurysm to exterior is a common presentation while rupture into surrounding structure deemed an emergency surgical attention. Hence, we report an unusual case of rupture of femoral pseudoaneurysm into urinary bladder who presented us with history of hematuria and was successfully managed. PMID:25887167

Shrestha, Kajan Raj; Luitel, Bhoj Raj; Shrestha, Ujma; Shrestha, Uttam Krishna

2015-01-01

213

Dynamic stress changes during earthquake rupture  

USGS Publications Warehouse

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.

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

1998-01-01

214

Capturing Continental Rupture Processes in Afar  

NASA Astrophysics Data System (ADS)

Both continental and oceanic rifting processes are highly 3D, but the stability of the along-axis segmentation from rifting to breakup, and its relationship to seafloor spreading remains debated. Three-dimensional models of the interactions of faults and magmatism in time and space are in development, but modelling and observations suggest that magmatic segments may propagate and/or migrate during periods of magmatism. Our ability to discriminate between the various models in large part depends on the quality of data in the ocean-transition zone, or, observations from zones of incipient plate rupture. Largely 2D crustal-scale seismic data from magmatic passive margins reveal large magmatic additions to the crust, but the timing of this heat and mass transfer is weakly constrained. Thus, the lack of information on the across rift breadth of the deforming zone at rupture, and the relationship between the early rift segmentation and the seafloor spreading segmentation represent fundamental gaps in knowledge. Our study of Earth's youngest magmatic margin, the superbly exposed, tectonically active southern Red Sea, aims to answer the following questions: What are the geometry and kinematics of active fault systems across the 'passive margin' to zone of incipient plate rupture? What is the relationship between the initial border fault segmentation, and the breakup zone segmentation? What is the distribution of active deformation and magmatism, and how does it compare to time-averaged strain patterns? We integrate results of recent experiments that suggest widespread replacement of crust and mantle lithosphere beneath the 'passive' margin, and explain the ongoing seismic deformation as a consequence of bending stresses across the ocean-continent transition, with or without a dynamic component.

Ebinger, Cynthia; Belachew, Manahloh; Tepp, Gabrielle; Keir, Derek; Ayele, Atalay

2014-05-01

215

Isolated unilateral rupture of the alar ligament.  

PubMed

Only 6 cases of isolated unilateral rupture of the alar ligament have been previously reported. The authors report a new case and review the literature, morbid anatomy, and pathogenesis of this rare injury. The patient in their case, a 9-year-old girl, fell head first from a height of 5 feet off the ground. She presented with neck pain, a leftward head tilt, and severe limitation of right rotation, extension, and right lateral flexion of the neck. Plain radiographs and CT revealed no fracture but a shift of the dens toward the right lateral mass of C-1. Magnetic resonance imaging of the cervical spine showed signal hyperintensity within the left dens-atlas space on both T1- and T2-weighted sequences and interruption of the expected dark signal representing the left alar ligament, suggestive of its rupture. After 12 weeks of immobilization in a Guilford brace, MRI showed lessened dens deviation, and the patient attained full and painless neck motion. Including the patient in this case, the 7 patients with this injury were between 5 and 21 years old, sustained the injury in traffic accidents or falls, presented with marked neck pain, and were treated with external immobilization. All patients had good clinical outcome. The mechanism of injury is hyperflexion with rotation. Isolated unilateral alar ligament rupture is a diagnosis made by excluding associated fracture, dislocation, or disruption of other major ligamentous structures in the craniovertebral junction. CT and MRI are essential in establishing the diagnosis. External immobilization is adequate treatment. PMID:24679079

Wong, Sui-To; Ernest, Kimberly; Fan, Grace; Zovickian, John; Pang, Dachling

2014-05-01

216

Forecasting the Rupture Directivity of Large Earthquakes  

NASA Astrophysics Data System (ADS)

Forecasting the rupture directivity of large earthquakes is an important problem in probabilistic seismic hazard analysis (PSHA), because directivity strongly influences ground motions. We cast this forecasting problem in terms of the conditional hypocenter distribution (CHD), defined to be the probability distribution of a hypocenter given the spatial distribution of fault slip (moment release). The simplest CHD is a uniform distribution for which the hypocenter probability density equals the moment-release probability density. We have compiled samples of CHDs from a global distribution of large earthquakes using three estimation methods: (a) location of hypocenters within the slip distribution from finite-fault inversions, (b) location of hypocenters within early aftershock distributions, and (c) direct inversion for the directivity parameter D, defined in terms of the degree-two polynomial moments of the source space-time function. The data from method (a) are statistically inconsistent with the uniform CHD suggested by McGuire et al. (2002) using method (c). Instead, the data indicate a 'centroid-biased' CHD, in which the expected distance between the hypocenter and the hypocentroid is less than that of a uniform CHD; i.e., the directivities inferred from finite-fault models appear to be closer to bilateral than predicted by the uniform CHD. One source of this discrepancy may be centroid bias in the second-order moments owing to poor localization of the slip in finite-fault inversions. We compare these observational results with CHDs computed from a large set of theoretical ruptures in the Southern California fault system produced by the Rate-State Quake simulator (RSQSim) of Dieterich and Richards-Dinger (2010) and discuss the implications for rupture dynamics and fault-zone heterogeneities.

Donovan, J. R.; Jordan, T. H.

2013-12-01

217

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

NASA Technical Reports Server (NTRS)

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.

Harf, F. H.

1978-01-01

218

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

NASA Technical Reports Server (NTRS)

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.

Harf, F. H.

1978-01-01

219

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

NASA Technical Reports Server (NTRS)

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.

Reeder, James R.

2010-01-01

220

Tendon rupture associated with simvastatin/ezetimibe therapy.  

PubMed

A case of spontaneous biceps tendon rupture in a physician during therapy with the combination of simvastatin and ezetimibe (Vytorin) is reported. Rechallenge produced tendinopathy in the contralateral biceps tendon that abated with drug discontinuation. Tendon rupture generally occurs in injured tendons. Physiological repair of an injured tendon requires degradation and remodeling of the extracellular matrix through matrix metalloproteinases (MMPs). Statins are known to inhibit MMPs. It was hypothesized that statins may increase the risk of tendon rupture by altering MMP activity. In conclusion, statins may increase the risk of tendon rupture by altering MMP activity. PMID:17599460

Pullatt, Raja C; Gadarla, Mamatha Reddy; Karas, Richard H; Alsheikh-Ali, Alawi A; Thompson, Paul D

2007-07-01

221

Complex earthquake rupture and local tsunamis  

USGS Publications Warehouse

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

Geist, E.L.

2002-01-01

222

Traumatic rupture of healed cataract wounds.  

PubMed

Three patients suffered blunt trauma that caused rupture of the site of cataract incision three to 12 years after surgery. Epithelial cells were noted in the old cataract would of a 79-year-old white man. The second patient, a 25-year-old black women, had bilateral ocular toxoplasmosis and loss of vitreous humor at the time of lens extraction. The third patient, a 63-year-old white woman, had open-angle glaucoma treated previously with filtering procedures and cyclocryotherapy. The ultimate outcome was poor in each case. PMID:937423

Kass, M A; Lahav, M; Albert, D M

1976-06-01

223

Rupture of lipid vesicles near solid surfaces  

NASA Astrophysics Data System (ADS)

The behavior of lipid vesicles near solid surfaces, despite its scientific and technological significance, is poorly understood. By simultaneously taking into account (i) the dynamics of spontaneous pore opening and closing in surface bound vesicles; (ii) their volume loss via leakage through the pores; (iii) and the propagation of their contact line, we have developed a simple model that can fully describe the detailed mechanism of and provide the necessary conditions for the rupture of vesicles and the subsequent formation of supported lipid bilayers. The predictions of the model are in qualitative agreement with many of the experimental observations.

Tak醫s-Nyeste, Annam醨ia; Der閚yi, Imre

2014-11-01

224

Exclusive pion electroproduction and transversity  

E-print Network

In this talk it is reported on an analysis of hard exclusive pion electroproduction within the handbag approach. Particular emphasis is laid on single-spin asymmetries. It is argued that a recent HERMES measurement of asymmetries measured with a transversely polarized target clearly indicate the occurrence of strong contributions from transversely polarized photons. Within the handbag approach such gamma_T --> pion transitions are described by the transversity GPDs accompanied by a twist-3 pion wave function. It is shown that this approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment.

P. Kroll

2010-07-16

225

Investigating Earthquake Rupture Processes in a Deep South African Gold Mine (Invited)  

NASA Astrophysics Data System (ADS)

A primary objective of the NELSAM (Natural Earthquake Laboratory in South African Mines) Project was to record the rupture processes in the near field of a mining-induced earthquake of M>3. When this project was initiated, it seemed likely that an earthquake this large would rupture the ancient Pretorius fault where it intersected the gold-bearing reef at a depth of 3600 m, near the bottom of TauTona Mine. To prepare, a small-scale network of borehole seismic and strain instrumentation was installed. Also, much effort was expended in geologic investigations in the immediate environs of the portion of the Pretorius fault where earthquake rupture was expected. Contrary to expectations, the M>3, earthquake never occurred, at least as of this writing. Nonetheless, this project has provided many insights regarding earthquake ruptures because of an opportunity that came up during the initial field investigations of the Pretorius fault. That is, a M2.2 earthquake ruptured the Pretorius fault in December 2004, before the NELSAM borehole instrumentation was installed. This earthquake was, however, well recorded by the mine-wide seismic network and so these seismograms, together with the extensive mapping of the rupture within the Pretorius fault zone, have enhanced considerably our understanding of earthquake source processes and the conditions causing an earthquake. The initial field studies revealed that the Pretorius fault is about 10 km long and dips nearly vertically, on average, with oblique slip up to 200 m. This slip occurred more than 2 billion years ago during the Archean. In the meantime, the Pretorius fault has been inactive until affected by mining operations. This extensive period of inactivity has allowed the fault zone material to recover much of its initial strength; thus, rupture across this fault is probably more like fresh rock fracture than frictional slip. After the M2.2 earthquake in December 2004, a comprehensive study of its effects on the Pretorius fault revealed oblique-normal slip across four non-parallel segments of the fault zone, with a maximum observed slip of 25 mm. The ambient state of stress measured in the environs of this study area is extensional with a vertically oriented, maximum principal stress due to the overburden that is about twice the minimum horizontal principal stress. These ambient stresses were altered substantially by the nearby mining so as to induce this M2.2 earthquake. Analysis of the ground motion data from the mine-wide seismic network indicated a seismic moment tensor with a shear component of 2.3e12 N-m as well as an implosive component, associated with coseismic collapse of the nearby mine stopes. Laboratory rock mechanics results were used to interpret the seismic moment and the maximum slip to infer a failure stress in the seismogenic zone of about 120 MPa. This high failure stress is consistent with the strength of the Pretorius fault zone material measured in the laboratory as well as with the radiated energy, 5.4e8 J, which is quite high for an earthquake of M2.2. In short, the rupture zone of this well-recorded earthquake was studied in detail to reveal many important insights concerning the source mechanics of earthquakes.

McGarr, A.; Fletcher, J. B.; Boettcher, M. S.; Heesakkers, V.; Johnston, M. J.; Reches, Z.

2010-12-01

226

Insight into the rupture process of a rare tsunami earthquake from near-field high-rate GPS  

NASA Astrophysics Data System (ADS)

We investigated the rupture duration and velocity of the October 25, 2010 Mentawai earthquake by examining high-rate GPS displacement data. This Mw=7.8 earthquake appears to have ruptured either an up-dip part of the Sumatran megathrust or a fore-arc splay fault, and produced tsunami run-ups on nearby islands that were out of proportion with its magnitude. It has been described as a so-called "slow tsunami earthquake", characterised by a dearth of high-frequency signal and long rupture duration in low-strength, near-surface media. The event was recorded by the Sumatran GPS Array (SuGAr), a network of high-rate (1 sec) GPS sensors located on the nearby islands of the Sumatran fore-arc. For this study, the 1 sec time series from 8 SuGAr stations were selected for analysis due to their proximity to the source and high-quality recordings of both static displacements and dynamic waveforms induced by surface waves. The stations are located at epicentral distances of between 50 and 210 km, providing a unique opportunity to observe the dynamic source processes of a tsunami earthquake from near-source, high-rate GPS. We estimated the rupture duration and velocity by simulating the rupture using the spectral finite-element method SPECFEM and comparing the synthetic time series to the observed surface waves. A slip model from a previous study, derived from the inversion of GPS static offsets and tsunami data, and the CRUST2.0 3D velocity model were used as inputs for the simulations. Rupture duration and velocity were varied for a suite of simulations in order to determine the parameters that produce the best-fitting waveforms.

Macpherson, K. A.; Hill, E. M.; Elosegui, P.; Banerjee, P.; Sieh, K. E.

2011-12-01

227

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

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皷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抯 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 1:01021 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.

Hartzell, Stephen; Mendoza, Carlos; Ram韗ez-Guzm醤, Leonardo; Zeng, Yuesha; Mooney, Walter

2013-01-01

228

Gluon propagator and transverse vertices  

SciTech Connect

It is shown explicitly that in the axial gauge the Slavnov-Taylor identity contains no useful information for determining the gluon propagator through the Dyson-Schwinger equation; rather, it is the transverse vertex which plays the crucial role.

Zhang, R.B.

1985-03-15

229

GPU Acceleration of Support Operator Rupture Dynamics  

NASA Astrophysics Data System (ADS)

SORD (Support Operator Rupture Dynamics) is an open-source software based on a fourth-order finite-difference method which can simulate 3D elastic wave propagation and spontaneous rupture on hexahedral mesh. It can be used for many kinds of surface boundary conditions, including free surface. The original software is developed by Geoffrey Ely from USC and modified by us for acceleration on GPU with NVIDIA CUDA. Our motivation on accelerating SORD on GPU is inspired by new generation GPU抯 superior ability on general purpose computing and NVIDIA CUDA抯 user-friendly developing environment for academic users. After translating the code from Fortran 95 to CUDA and implementing the transformed CUDA SORD code on the NVIDIA Tesla C1060, we obtained a factor of 6 speedup as compared to the original Fortran 95 version code , which was run on Intel Xeon X5570 2.9GHz. Our 3D wave solutions show explicitly visually in 3D format the different propagating wave fronts associated with the P and S waves according to the appropriate elastic parameter ratios. Because of the limitation of the global memory of NVIDIA Tesla C1060, too many more grid points would slow the calculation. However, by using the new NVIDIA Tesla C2070, which has 6 GBytes global memory, we can increase the simulation data size into 350X350X350.

Zhou, Y.; Dong, T.; Yuen, D. A.

2010-12-01

230

Roles of hypertension in the rupture of intracranial aneurysms  

PubMed Central

Background and Purpose Systemic hypertension has long been considered as a risk factor of aneurysmal rupture. However, a causal link between systemic hypertension and the development of aneurysmal rupture has not been established. In this study, using a mouse model of intracranial aneurysm rupture, we examined the roles of systemic hypertension in the development of aneurysmal rupture. Methods Aneurysms were induced by a combination of deoxycorticosterone acetate (DOCA)-salt induced hypertension and a single injection of elastase into the cerebrospinal fluid in mice. Anti-hypertensive treatment was started six days after aneurysm induction. Aneurysmal rupture was detected by neurological symptoms and confirmed by the presence of intracranial aneurysm with subarachnoid hemorrhage. Hydralazine (direct vasodilator) or the discontinuation of the DOCA-salt treatment was used to assess the roles of systemic hypertension. Captopril (angiotensin converting enzyme inhibitor) or losartan (angiotensin II type 1 receptor antagonist) was used to assess the roles of the local renin-angiotensin system in the vascular wall. Results Normalization of blood pressure by hydralazine significantly reduced the incidence of ruptured aneurysms and the rupture rate. There was a dose dependent relationship between the reduction of blood pressure and the prevention of aneurysmal rupture. Captopril and losartan were able to reduce the rupture rates without affecting systemic hypertension induced by DOCA-salt treatment. Conclusions Normalization of blood pressure after aneurysm formation prevented aneurysmal rupture in mice. In addition, we found that the inhibition of the local renin-angiotensin system independent from the reduction of blood pressure can prevent aneurysmal rupture. PMID:24370755

Tada, Yoshiteru; Wada, Kosuke; Shimada, Kenji; Makino, Hiroshi; Liang, Elena I.; Murakami, Shoko; Kudo, Mari; Kitazato, Keiko T.; Nagahiro, Shinji; Hashimoto, Tomoki

2014-01-01

231

TRANSVERSE OSCILLATIONS IN CHROMOSPHERIC MOTTLES  

SciTech Connect

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.

Kuridze, D.; Mathioudakis, M.; Jess, D. B.; Keenan, F. P. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, Belfast BT7 1NN (United Kingdom); Morton, R. J.; Erdelyi, R. [Solar Physics and Space Plasma Research Centre (SP2RC), University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Dorrian, G. D., E-mail: dkuridze01@qub.ac.uk [Institute of Astronomy and Astrophysics, National Observatory of Athens, Lofos Nymfon, Thiseio, P.O. Box 20048, GR-11810 Athens (Greece)

2012-05-01

232

High strength nickel-chromium-iron austenitic alloy  

DOEpatents

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.

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

1980-01-01

233

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

USGS Publications Warehouse

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

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

1983-01-01

234

Realizing vector meson dominance with transverse charge densities  

SciTech Connect

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.

Gerald Miller, Mark Strikman, Christian Weiss

2011-10-01

235

Material contrast does not predict earthquake rupture propagation Ruth A. Harris  

E-print Network

Material contrast does not predict earthquake rupture propagation direction Ruth A. Harris U) earthquake rupture propagation direction can be predicted from the material contrast, and 2) earthquake (2005), Material contrast does not predict earthquake rupture propagation direction, Geophys. Res. Lett

Day, Steven M.

236

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

E-print Network

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

Rosakis, Ares J.

237

Achilles tendon rupture following coblation for insertional Achilles tendinosis.  

PubMed

Radiofrequency microdebridement for Achilles tendinosis is a relatively new technique. We report a case of Achilles tendon rupture in a patient eight weeks after coblation for his right insertional Achilles tendinosis. We believe that this is the first reported case of Achilles tendon rupture following this new treatment of radiofrequency microdebridement for chronic Achilles tendinosis. PMID:20307450

Akhtar, M A; Montgomery, H; Shenolikar, A

2009-03-01

238

Ruptured diaphragmatic eventration: a rare cause of acute postpartum dyspnea.  

PubMed

Rupture of a maternal diaphragmatic hernia (DH) during pregnancy is a rare but significant complication. We describe a case of a maternal ruptured DH, presenting as acute postpartum dyspnea, which required urgent operative repair. We report our surgical strategy and review the key concepts in the multidisciplinary management of this condition. PMID:22632531

Servais, Elliot L; Stiles, Brendon M; Finnerty, Brendan M; Paul, Subroto

2012-06-01

239

Achilles tendon rupture and sciatica: a possible correlation  

Microsoft Academic Search

The association between Achilles tendon rupture and sciatica was investigated by questionnaire in 138 patients who underwent repair of an Achilles tendon rupture, and in a group of individuals nominated by the patients, matched for age, sex, and occupation. A total of 102 patients (74%) and 128 peer nominated controls (71%) replied to the questionnaire. Of the 102 respondent patients,

N. Maffulli; A. S. Irwin; M. G. Kenward; F. Smith; R. W. Porter

1998-01-01

240

Splenic rupture after diagnostic colonoscopy: a case report.  

PubMed

Colonoscopy is a commonly used diagnostic and therapeutic procedure. Splenic injury or rupture after this procedure is rare. We report a case of splenic rupture and hematoma in a middle-aged man who presented with symptoms of worsened anemia after diagnostic colonoscopy. PMID:16816956

Zenooz, Navid A; Win, Thomas

2006-09-01

241

SECONDARY POSTPARTUM HAEMORRHAGE DUE TO RUPTURE OF UTERUS  

Microsoft Academic Search

We report a very unusual case of secondary postpartum hemorrhage due to uterine rupture. Our case was a 23 years old lady who presented with heavy bleeding per vagina and gave his- tory of home delivery. Rupture was most probably caused by injudicious use of oxytocic injec- tion by a Traditional Birth Attendant at home. Surprisingly, after recovering completely from

Amna Memon; Raheel Sikandar; Fatima Memon; Farhana Saeed

242

Survivors of ruptured abdominal aortic aneurysm: the iceberg's tip  

Microsoft Academic Search

In four and a half years 25 patients in one community suffered a ruptured abdominal aortic aneurysm. Eleven died at home, nine died without operation in hospital, and only five had the aneurysm removed. There were four survivors. A further seven patients might have lived had they had a prompt operation. The average operative mortality for ruptured aneurysms among series

R H Armour

1977-01-01

243

Anterior tibial compartment syndrome following rupture of a popliteal cyst  

Microsoft Academic Search

A ruptured popliteal cyst usually results in calf pain and swelling. We report the case of a patient with rheumatoid arthritis\\u000a who developed anterior compartment syndrome of the leg following rupture of a popliteal cyst. Since acute compartment syndrome\\u000a requires prompt treatment, clinicians should be aware of this rare complication.

Toshio Ushiyama; Taku Kawasaki; Yoshitaka Matsusue

2003-01-01

244

Cutaneous Silicone Granuloma Mimicking Breast Cancer after Ruptured Breast Implant  

PubMed Central

Cutaneous manifestations due to migration of silicone from ruptured implants are rare. Migrated silicone with cutaneous involvement has been found in the chest wall, abdominal wall, and lower extremities. We describe a case of cutaneous silicone granuloma in the breast exhibiting unusual growth mimicking breast cancer after a ruptured implant. PMID:23198167

El-Charnoubi, Waseem Asim Ghulam; Foged Henriksen, Trine; Joergen Elberg, Jens

2011-01-01

245

The physics of strain localization in dynamic earthquake rupture simulations  

E-print Network

) and Jean M. Carlson (UCSB) #12;Goal: improve our understanding of the basic physics of earthquake rupture of the physics governing earthquake rupture. Why? 2nd Problem: Occur at extreme physical conditions (hard in materials similar to faults: Faults contain granular material (gouge) Very finely crushed, no crystal

Daub,Eric G.

246

The relationship between knee strength and functional stability before and after anterior cruciate ligament reconstruction  

Microsoft Academic Search

Functional stability of the knee is dependent on an intact ligamentous system and the timely and efficient contraction of supporting musculature. The aim of this study was to assess the relationship between muscle strength and functional stability in 31 patients pre- and post-operatively, following a unilateral anterior cruciate ligament rupture. All subjects underwent reconstructive surgery using semitendonosis and gracilis tendons.

S. L. Keays; J. E. Bullock-Saxton; P. Newcombe; A. C. Keays

2003-01-01

247

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

SciTech Connect

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

Swindeman, R.W.

1998-03-01

248

Malignant fibrous histiocytoma presenting as hemoperitoneum mimicking hepatocellular carcinoma rupture.  

PubMed

Malignant fibrous histiocytoma (MFH) is a pleomorphic mesenchynal sarcoma. It is uncommonly arises primarily from the intra-peritoneal cavity. Primary peritoneal MFH with tumor bleeding and rupture is rare. We describe the imaging features of a 70-year-old patient presenting with ruptured hemorrhagic peritoneal MFH at subhepatic area, accompanied by massive hemoperitoneum, mimicking a ruptured pedunculated hepatocellular carcinoma. Computed tomography (CT) revealed a large heterogeneous enhanced subhepatic mass with adjacent liver, gallbladder and colon invasion. Tumor hemorrhage and rupture complicated with peritoneal seeding and massive bloody ascites were also detected. Angiography showed a hypervascular tumor fed by enlarged right hepatic arteries, cystic artery and omental branches of gastroepiploic artery. The patient underwent laparotomy for tumor resection, but the tumor recurred one month after operation. To our knowledge, the CT appearance of ruptured intraperitoneal MFH complicated by hemoperitoneum has not been previously described. PMID:18081238

Chen, Hsin-Chi; Chen, Chi-Jen; Jeng, Chin-Ming; Yang, Chan-Ming

2007-12-21

249

Material contrast does not predict earthquake rupture propagation direction  

USGS Publications Warehouse

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.

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

2005-01-01

250

Rupture of right hepatic duct into hydatid cyst.  

PubMed

Echinococcal disease can develop anywhere in the human body. The liver represents its most frequent location. Hepatic hydatid cysts may rupture into the biliary tract, thorax, peritoneum, viscera, digestive tract or skin. We report a rare case with rupture of the right hepatic duct into a hydatid cyst in a woman with known hydatid disease and choledocholithiasis. The increased intra-luminal pressure in the biliary tree caused the rupture into the adjacent hydatid cyst. The creation of the fistula between the right hepatic duct and the hydatid cyst decompressed the biliary tree, decreased the bilirubin levels and offered a temporary resolution of the obstructive jaundice. Rupture of a hydatid cyst into the biliary tree usually leads to biliary colic, cholangitis and jaundice. However, in case of obstructive jaundice due to choledocholithiasis, it is possible that the cyst may rupture by other way around while offering the patient a temporary relief from his symptoms. PMID:22876065

Michalopoulos, Nickolaos; Laskou, Styliani; Papavramidis, Theodossis S; Pliakos, Ioannis; Kotidis, Eustathios; Kesisoglou, Isaak; Papavramidis, Spiros T

2012-08-01

251

Rupture of Right Hepatic Duct into Hydatid Cyst  

PubMed Central

Echinococcal disease can develop anywhere in the human body. The liver represents its most frequent location. Hepatic hydatid cysts may rupture into the biliary tract, thorax, peritoneum, viscera, digestive tract or skin. We report a rare case with rupture of the right hepatic duct into a hydatid cyst in a woman with known hydatid disease and choledocholithiasis. The increased intra-luminal pressure in the biliary tree caused the rupture into the adjacent hydatid cyst. The creation of the fistula between the right hepatic duct and the hydatid cyst decompressed the biliary tree, decreased the bilirubin levels and offered a temporary resolution of the obstructive jaundice. Rupture of a hydatid cyst into the biliary tree usually leads to biliary colic, cholangitis and jaundice. However, in case of obstructive jaundice due to choledocholithiasis, it is possible that the cyst may rupture by other way around while offering the patient a temporary relief from his symptoms. PMID:22876065

Laskou, Styliani; Papavramidis, Theodossis S.; Pliakos, Ioannis; Kotidis, Eustathios; Kesisoglou, Isaak; Papavramidis, Spiros T.

2012-01-01

252

Size and Location of Ruptured Intracranial Aneurysms  

PubMed Central

Objective The aim of study was to review our patient population to determine whether there is a critical aneurysm size at which the incidence of rupture increases and whether there is a correlation between aneurysm size and location. Methods We reviewed charts and radiological findings (computed tomography (CT) scans, angiograms, CT angiography, magnetic resonance angiography) for all patients operated on for intracranial aneurysms in our hospital between September 2002 and May 2004. Of the 336 aneurysms that were reviewed, measurements were obtained from angiograms for 239 ruptured aneurysms by a neuroradiologist at the time of diagnosis in our hospital. Results There were 115 male and 221 female patients assessed in this study. The locations of aneurysms were the middle cerebral artery (MCA, 61), anterior communicating artery (ACoA, 66), posterior communicating artery (PCoA, 52), the top of the basilar artery (15), internal carotid artery (ICA) including the cavernous portion (13), anterior choroidal artery (AChA, 7), A1 segment of the anterior cerebral artery (3), A2 segment of the anterior cerebral artery (11), posterior inferior cerebellar artery (PICA, 8), superior cerebellar artery (SCA, 2), P2 segment of the posterior cerebral artery (1), and the vertebral artery (2). The mean diameter of aneurysms was 5.472.536 mm in anterior cerebral artery (ACA), 6.843.941 mm in ICA, 7.093.652 mm in MCA and 6.213.697 mm in vertebrobasilar artery. The ACA aneurysms were smaller than the MCA aneurysms. Aneurysms less than 6 mm in diameter included 37 (60.65%) in patients with aneurysms in the MCA, 43 (65.15%) in patients with aneurysms in the ACoA and 29 (55.76%) in patients with aneurysms in the PCoA. Conclusion Ruptured aneurysms in the ACA were smaller than those in the MCA. The most prevalent aneurysm size was 3-6 mm in the MCA (55.73%), 3-6 mm in the ACoA (57.57%) and 4-6 mm in the PCoA (42.30%). The more prevalent size of the aneurysm to treat may differ in accordance with the location of the aneurysm. PMID:19242565

Jung, Yong-Tae; Kim, Moo-Seong; Eun, Choong-Ki; Jang, Sang-Hwan

2009-01-01

253

Preliminary evaluation of tensile and stress-rupture behavior of W + 24 at. pct Re + 0.4 at. pct HfC wire  

NASA Technical Reports Server (NTRS)

Results are presented of an evaluation of tensile properties and stress-rupture bahavior of a small-diameter W24ReHfC (W-24Re-0.4(HfC)) wire, which is considered to be an excellent reinforcing fiber candidate for a variety of metal-matrix composites. The results were compared to data of Petrasek (1972) on W4ReHfC (W-4Re-0.4(HfC)) wire. It was found that the room-temperature (RT) tensile strength of the W24ReHfC wire was about 3250 MPa, higher than that of the W4ReHfC (3160 MPa) and WHfC (2250 MPa) wires. Above 1366 K, the W4ReHfC wire had both a greater tensile strength and the stress rupture strength than the W24ReHfC wire.

Yun, H. M.

1993-01-01

254

Strength Training for Girls.  

ERIC Educational Resources Information Center

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

Connaughton, Daniel; Connaughton, Angela; Poor, Linda

2001-01-01

255

Do strengths measure up?  

Microsoft Academic Search

Purpose This paper sets out to draw comparisons and make linkages between strengths and competency methodologies. Whereas some authors have seen the strengths approach as a revolution in human resources (HR), the authors of this paper see it more as a natural evolution. The paper aims to overview the strengths approach as well as presenting a case study of

Nicky Garcea; Stephen Isherwood; Alex Linley

2011-01-01

256

Simultaneous bilateral Achilles tendon ruptures associated with statin medication despite regular rock climbing exercise  

Microsoft Academic Search

IntroductionRuptures of the Achilles tendon are common however simultaneous ruptures occur less frequently. Eccentric loading exercise programmes have been used to successfully treat Achilles tendinopathy.

Michael R. Carmont; Adrian M. Highland; Christopher M. Blundell; Mark B. Davies

2009-01-01

257

Triceps tendon rupture: an uncommon orthopaedic condition.  

PubMed

Triceps tendon disruption is a rare orthopaedic injury that can lead to poor outcomes if misdiagnosed or managed inappropriately. This case report illustrates the importance of early, precise diagnosis of triceps rupture by clinical and radiological examination with appropriate management. A weightlifter who had fallen while riding his bike presented with pain, swelling around the posterior aspect of the left arm just above the elbow. Physical examination revealed ecchymosis and weakness in elbow extension. A radiograph of the elbow showed a small fleck of bone proximal to the tip of the olecranon. The patient was initially stabilised. Early intervention in the form of primary tendon repair was performed within 3?days and rehabilitation was started. The patient improved significantly to his best possible functional status with Mayo elbow score of 85. Early intervention was the key to better prognosis. PMID:25766435

Bunshah, Jamshed Jal; Raghuwanshi, Sagar; Sharma, Deepak; Pandita, Aakash

2015-01-01

258

Multifractal scaling of thermally activated rupture processes.  

PubMed

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

Sornette, D; Ouillon, G

2005-01-28

259

Dihadron Fragmentation Functions and Transversity  

E-print Network

We present preliminary results for an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data for proton and deuteron targets by HERMES and COMPASS allow for a flavor separation of the valence components of transversity, while di-hadron fragmentation functions are taken from the semi-inclusive production of two pion pairs in back-to-back jets in $e^+ e^-$ annihilation. The latter data from Belle have been reanalyzed using the replica method and a more realistic estimate of the uncertainties on the chiral-odd interference fragmentation function has been obtained. After encoding this piece of information into the deep-inelastic scattering cross section, the transversity has been re-extracted by using the most recent and more precise COMPASS data for proton target. This picture represents the current most realistic estimate of the uncertainties on our knowledge of transversity. The preliminary results indicate that the valence up component seems smaller and with a narrower error band than in previous extraction.

Marco Radici; A. Courtoy; Alessandro Bacchetta

2014-09-23

260

Dihadron Fragmentation Functions and Transversity  

NASA Astrophysics Data System (ADS)

We present preliminary results for an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data for proton and deuteron targets by HERMES and COMPASS allow for a flavor separation of the valence components of transversity, while di-hadron fragmentation functions are taken from the semi-inclusive production of two pion pairs in back-to-back jets in e+e- annihilation. The latter data from Belle have been reanalyzed using the replica method and a more realistic estimate of the uncertainties on the chiral-odd interference fragmentation function has been obtained. After encoding this piece of information into the deep-inelastic scattering cross section, the transversity has been re-extracted by using the most recent and more precise COMPASS data for proton target. This picture represents the current most realistic estimate of the uncertainties on our knowledge of transversity. The preliminary results indicate that the valence up component seems smaller and with a narrower error band than in previous extraction.

Radici, Marco; Courtoy, A.; Bacchetta, Alessandro

2015-01-01

261

[New clinical grading in ruptured cerebral aneurysm].  

PubMed

A new clinical grading of subarachnoid hemorrhage (SAH) due to ruptured aneurysm, classified by the presence or absence of vomiting, and by the duration of initial unconciousness at the time of bleeding, is proposed. Grade I: headache without vomiting, Grade II: headache, vomiting, and/or loss of consciousness lasting less than one hour, Grade III: loss of consciouness for over one hour. Grade IV: permanent unconsciousness or cerebral herniation signs. Based on the clinical records, 142 cases of ruptured cerebral aneurysms directly operated on in phases varying from peracute phase (within 72 hours) to delayed phase (22 days or over) were retrospectively analyzed. They included 99 cases which were operated on under microscope. The Hunt & Hess grading was applied just before surgery. Outcome at the 6 month to 1 year follow-up was rated as good, fair, poor and dead. Correlations between the severity and the outcome were calculated using the chi-square test and the levels of significance were compared with those between the recent Hunt and Hess grading and the outcome. In the total of 142 cases, correlation between the clinical severity and the outcome was significant (P less than 0.0005), whereas correlation between the Hunt & Hess grading and the outcome was not significant. In the analysis of cases classified by the operative timing, the clinical severity showed good correlation in the peracute (within 72 hours after SAH) (P less than 0.05) alone, while Hunt & Hess grading showed correlation in delayed phase alone. Neither of the gradings was significant in the acute phase or subacute phase.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3785560

Sato, J; Masuzawa, H; Shiraishi, K; Kanazawa, I; Kamitani, H

1986-09-01

262

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

NASA Astrophysics Data System (ADS)

The study of dynamically propagating shear cracks along geometrically complex paths is important to understanding the mechanics of earthquakes. Recent laboratory fracture studies of Rousseau and Rosakis examined a branched configuration, analogous to their study of rupture along a bent fault path [Rousseau and Rosakis, JGR, 2003], to enhance understanding of the behavior of a shear rupture approaching the intersection of two paths. Whereas crack motion along a simple bent path is readily explained by means of the energy available to sustain the propagating crack, or through a crack tip stress field criterion, the behavior of multiple paths displays more intricate variations featuring the inability of the crack to extend along secondary paths situated at shallow angles with respect to the initial direction of propagation. Secondary paths located at larger angles, on the extensional side, generally promote simultaneous extension along both paths beyond the junction, in contrast to preferred motion along the straight path, which is favored when secondary paths are situated on the compressional side. The experiments involve impact loading of thin plates of Homalite-100, a photoelastic polymer, which are cut along branched paths and weakly glued back together everywhere except along a starter notch near the impact site. High-speed photography of isochromatic fringe patterns (lines of constant difference between in-plane principal stresses) characterized the transient deformation field associated with the impact and rupture propagation. We adapted the ABAQUS/Explicit dynamic finite element program to analyze the propagation of shear cracks along such branched weakened paths. Two configurations for weakened paths, branches at 35 to the compressional side and the extensional side, were analyzed. We implemented a linear slip-weakening failure model as a user-defined constitutive relation within the ABAQUS program, where weakening could be included in either or both of (1) a cohesive part, c = c(? u) (where ? u = slip) of the shear strength that is insensitive to compressive normal stress ?, and (2) a frictional part f ?, with friction coefficient f = f(? 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.

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

2005-12-01

263

Missing transverse energy significance at CMS  

E-print Network

Missing transverse energy significance may be used to help distinguish real missing transverse energy due to undetected particles from spurious missing transverse energy due to resolution smearing. We present a description of the missing transverse energy significance variable, and assess its performance in Z$\\rightarrow\\mu\\mu$, dijet, and W$\\rightarrow e\

Nathan Mirman; Yimin Wang; James Alexander

2014-09-10

264

Magnetic field strength of active region filaments  

NASA Astrophysics Data System (ADS)

Aims: We study the vector magnetic field of a filament observed over a compact active region neutral line. Methods: Spectropolarimetric data acquired with TIP-II (VTT, Tenerife, Spain) of the 10 830 spectral region provide full Stokes vectors that were analyzed using three different methods: magnetograph analysis, Milne-Eddington inversions, and PCA-based atomic polarization inversions. Results: The inferred magnetic field strengths in the filament are around 600-700 G by all these three methods. Longitudinal fields are found in the range of 100-200 G whereas the transverse components become dominant, with fields as high as 500-600 G. We find strong transverse fields near the neutral line also at photospheric levels. Conclusions: Our analysis indicates that strong (higher than 500 G, but below kG) transverse magnetic fields are present in active region filaments. This corresponds to the highest field strengths reliably measured in these structures. The profiles of the helium 10 830 lines observed in this active region filament are dominated by the Zeeman effect.

Kuckein, C.; Centeno, R.; Mart韓ez Pillet, V.; Casini, R.; Manso Sainz, R.; Shimizu, T.

2009-07-01

265

Fracture morphology of tensile cracks and rupture velocity  

NASA Astrophysics Data System (ADS)

Desiccation cracks in starch-water mixtures are studied with respect to morphological features, mainly plumose structures, on their faces. Specimens have diameters of 50-100 mm and thicknesses of 2-40 mm. Structures similar to those on joints in rocks are found. Rupture velocities are measured from videos and estimated from photos. Rupture covers the range from spontaneously nucleating, dynamic cracks with velocities of 100-200 mm/s to quasi-static cracks with velocities of 0.1 mm/s and less. Plumose lines give the rupture direction, and their relation to rupture velocity is similar to the relation between seismic rays and seismic wave velocity. A ray-tracing method from seismology is used to calculate plumose lines for depth-dependent rupture velocity. Moreover, an inverse method, based on finite difference travel times and conjugate gradients, is developed to invert a set of measured plumose directions into a rupture-velocity distribution which can also depend on the horizontal coordinate on the rupture surface. The main results of this paper are as follows. (1) Plumose lines can successfully be inverted into relative rupture velocity. (2) In thin starch layers (thickness less than 0.2 times diameter), rupture velocity decreases from top to bottom by a factor of 2-5, following a decrease of tensile stress due to the increase in water concentration. (3) Horizontal variation of rupture velocity reflects horizontal variation of stress, including stress relaxation due to the propagating crack, and ranges from dynamic to quasi-static velocities. (4) In thick starch layers (thickness about 0.5 times diameter), rupture is predominantly quasi-static. (5) Starch cracks sometimes have a fringe zone where topographic amplitudes are higher and rupture velocities lower than on the main part of the crack; this probably also applies to joints in rocks and their fringe zones. (6) Starch-water mixtures at rupture have a Poisson ratio close to 0.5. Cracks in starch are closest to subsidence or diagenesis joints in sedimentary rocks.

M黮ler, Gerhard; Dahm, Torsten

2000-01-01

266

Transverse wakefields at high dispersion  

SciTech Connect

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

Decker, F.J.

1992-03-01

267

Flutter analysis using transversality theory  

NASA Technical Reports Server (NTRS)

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.

Afolabi, D.

1993-01-01

268

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

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

269

Strength Modeling Report  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

270

Rupture geometry of microearthquakes inferred from analysis of multiple events  

NASA Astrophysics Data System (ADS)

Complicated waveforms of some swarm earthquakes in West Bohemia, Central Europe indicate complicated rupture history and possible space separation of several subruptures. I obtained the position and timing of the subevents building up the multiple event by waveform modeling with the use of empirical Green's functions. In total 18 multiple events were successfully modeled as double or triple events with separate rupture positions. The separation of subsources reached 100 ms in time and 320 m in space. The relative positions of the subevents with respect to the geometry of the fault indicate that most of them occurred very close to the common fault plane that was activated during the swarm. The space-time separation of the subevents corresponds to a speed of 3.0 km/s, a value typical for rupture propagation of large earthquakes. The later subevents occur farther than the nominal rupture radius of the first subevent, and their mutual distance scales with magnitude. These observations suggest that the analyzed multiple-events share a common fault surface and that their subevents represent individual rupture episodes. The angular distribution of the position vectors of later subevents indicates that many of them result from a slip-parallel rupture growth, while some of the ruptures propagate upwards. The hypocenters of the multiple events are not distributed uniformly on the fault plane; their clustering indicates that some patches of the fault are more likely to generate a stick-slip failure than the others.

Fischer, T.

2005-12-01

271

A novel indirect tensile test method to measure the biaxial tensile strength of concretes and other quasibrittle materials  

SciTech Connect

A novel indirect tensile test method, the biaxial flexure test (BFT) method, has been developed to measure the biaxial tensile strength of concretes. The classical modulus of rupture (MOR) test has been generalized to three dimensions. In this method, we use a circular plate as the new test specimen. This plate is supported by an annular ring. We apply an external load to this specimen through a circular edge. The centers of the specimen, the loading device and the support are identical. The biaxial tensile strength measured by this new method is about 19% greater than the uniaxial tensile strength obtained from the classical modulus of rupture test as reported by other researchers. However, at the same time, we also found that the stochastic deviation of the biaxial tensile strength is about 63% greater than the uniaxial strength.

Zi, Goangseup [Department of Civil, Environmental and Architectural Engineering, Korea, University, 5 Ga 1, An-Am Dong, Sung-Buk Gu, Seoul, 136-701 (Korea, Republic of)], E-mail: g-zi@korea.ac.kr; Oh, Hongseob [Department of Civil Engineering, Jinju National University, 150 Chilam Dong, Jinju, Kyongnam, 660-758 (Korea, Republic of); Park, Sun-Kyu [Department of Civil Engineering, Sungkyunkwan University, 300 Cheoncheon Dong, Jangan Gu, Suwon, Gyeonggi, 440-746 (Korea, Republic of)

2008-06-15

272

Effects of Porosity on Strength of Carbon-Carbon Composites  

Microsoft Academic Search

Filament wound\\/CVD (Chemical Vapor Deposition) carbon-carbon composites have received considerable attention and application within the past few years because of their desirable characteristics such as high heat of ablation, thermal shock resistance, high strength at elevated temperatures, and chemical inertness. However, poor mechanical properties in the transverse direction have hampered the total effectiveness of these composites in some applications and

Gilbert William Brassell; James A. Horak; Barry Lynn Butler

1975-01-01

273

Blunt traumatic cardiac rupture. A 5-year experience.  

PubMed Central

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

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

1990-01-01

274

Interaction of dynamic rupture with small-scale heterogeneities  

NASA Astrophysics Data System (ADS)

Broadband ground motion simulations, with frequencies up to 10Hz, are important for engineering purposes, in particular for seismic hazard assessment for critical facilities. One problem in such simulations is the generation of high frequency radiation emitted during the dynamic rupture process. Ad-hoc kinematic rupture characterizations can be tweaked through empirical models to radiate over the desired frequency range, but their physical consistency remains questionable. In contrast, for physically self-consistent dynamic rupture modeling, controlled by friction, material parameters and the adopted physical laws, the mechanism that may lead to appropriate high-frequency radiation require heterogeneity in friction, stress, or fault geometry (or even all three quantities) at unknown but small length scales. Dunham at al. (2011) studied dynamic rupture propagation on rough faults in 2D, and described how fault roughness excites high-frequency radiation. In our study, we focus on the interaction of the dynamic rupture with small-scale heterogeneities on planar faults in 3D. We study effects of the interaction of dynamic rupture with 1) small-scale heterogeneities in the medium (that is, randomized 3D wave speed and density variations), and 2) small-scale heterogeneities in the frictional parameters. Our numerical results show significant variations in rupture velocity or peak slip velocity if small-scale heterogeneities are present. This indicates that the dynamic rupture is sensitive to both types of spatial inhomogeneity. At the same time we observe that the resulting near-source seismic wave fields are not very sensitive to these rupture variations, indicating that wavefront healing effects may "simplify" the complex seismic radiation once the waves propagated several wave-lengths away from the fault.

Galis, Martin; Mai, P. Martin

2014-05-01

275

Detachment of agglutinin-bonded red blood cells. I. Forces to rupture molecular-point attachments.  

PubMed Central

A simple micromechanical method has been developed to measure the rupture strength of a molecular-point attachment (focal bond) between two macroscopically smooth membrane capsules. In the procedure, one capsule is prepared with a low density coverage of adhesion molecules, formed as a stiff sphere, and held at fixed position by a micropipette. The second capsule without adhesion molecules is pressurized into a spherical shape with low suction by another pipette. This capsule is maneuvered to initiate point contact at the pole opposite the stiff capsule which leads to formation of a few (or even one) molecular attachments. Then, the deformable capsule is slowly withdrawn by displacement of the pipette. Analysis shows that the end-to-end extension of the capsule provides a direct measure of the force at the point contact and, therefore, the rupture strength when detachment occurs. The range for point forces accessible to this technique depends on the elastic moduli of the membrane, membrane tension, and the size of the capsule. For biological and synthetic vesicle membranes, the range of force lies between 10(-7)-10(-5) dyn (10(-12)-10(-10) N) which is 100-fold less than presently measurable by Atomic Force Microscopy! Here, the approach was used to study the forces required to rupture microscopic attachments between red blood cells formed by a monoclonal antibody to red cell membrane glycophorin, anti-A serum, and a lectin from the snail-helix pomatia. Failure of the attachments appeared to be a stochastic function of the magnitude and duration of the detachment force. We have correlated the statistical behavior observed for rupture with a random process model for failure of small numbers of molecular attachments. The surprising outcome of the measurements and analysis was that the forces deduced for short-time failure of 1-2 molecular attachments were nearly the same for all of the agglutinin, i.e., 1-2 x 10(-6) dyn. Hence, microfluorometric tests were carried out to determine if labeled agglutinins and/or labeled surface molecules were transferred between surfaces after separation of large areas of adhesive contact. The results showed that the attachments failed because receptors were extracted from the membrane. Images FIGURE 1 FIGURE 4 PMID:2065188

Evans, E; Berk, D; Leung, A

1991-01-01

276

TachoSil for postinfarction ventricular free wall rupture.  

PubMed

Despite a decline in the last three decades, postinfarction ventricular free wall rupture still complicates more than 3% of acute ST-elevation myocardial infarctions and remains a surgical challenge. TachoSil (Nycomed, Zurich, Switzerland) is an equine collagen patch coated with human fibrinogen and human thrombin, which has recently been used for haemostasis in cardiovascular surgery, but its potential usefulness in free wall rupture has not been reported. Initial clinical experience with an on-pump sutureless technique without cardioplegia, using wide TachoSil patching to achieve free wall rupture repair, has been described. PMID:22419793

Pocar, Marco; Passolunghi, Davide; Bregasi, Alda; Donatelli, Francesco

2012-06-01

277

TachoSil for postinfarction ventricular free wall rupture  

PubMed Central

Despite a decline in the last three decades, postinfarction ventricular free wall rupture still complicates more than 3% of acute ST-elevation myocardial infarctions and remains a surgical challenge. TachoSil (Nycomed, Zurich, Switzerland) is an equine collagen patch coated with human fibrinogen and human thrombin, which has recently been used for haemostasis in cardiovascular surgery, but its potential usefulness in free wall rupture has not been reported. Initial clinical experience with an on-pump sutureless technique without cardioplegia, using wide TachoSil patching to achieve free wall rupture repair, has been described. PMID:22419793

Pocar, Marco; Passolunghi, Davide; Bregasi, Alda; Donatelli, Francesco

2012-01-01

278

Endovascular Treatment of an Aortic Traumatic Double Rupture  

PubMed Central

Traumatic thoracic aortic rupture is a life-threatening condition; aortic isthmus is the most common site of rupture, but in rare cases traumatic injury can localize elsewhere, such as at aortic arch or at the level of the diaphragm. In the past few years, endovascular treatment of traumatic aortic injury became a safe procedure, with lower mortality and complication, if compared with open surgery. We report a case of a 40-year-old-man admitted to emergency department after a violent car crash in which an aortic traumatic double rupture was successfully treated with two endovascular stent-grafts coverage. PMID:25859315

Attin, Domenico; Buia, Francesco; Russo, Vincenzo; Pilato, Emanuele; Lovato, Luigi; Bartolomeo, Roberto Di; Zompatori, Maurizio

2015-01-01

279

Prophylactic decompression of extensor pollicis longus to prevent rupture.  

PubMed

We present a case of a patient with spontaneous rupture of right extensor pollicis longus (EPL) tendon, who had also developed left wrist pain and weakness in his left EPL that MRI studies confirmed to be caused by tendinosis. Subsequently, decompression of left EPL and reconstruction of right EPL with palmaris longus tendon graft was undertaken. In this case, decompression of the left EPL tendon led to resolution of the patient's symptoms as well as preventing tendon rupture. We advocate the use of ultrasound imaging to evaluate EPL in these cases and prophylactic decompression of EPL tendon to avoid rupture in those patients found to have tendinosis. PMID:23780776

Navaratnam, A V; Ball, S; Eckersley, R

2013-01-01

280

Odd Independent Transversals are Odd  

Microsoft Academic Search

We put the nal piece into a puzzle rst introduced by Bollob as, Erd} os and Szemer edi in 1975. For arbitrary positive integers n and r we determine the largest integer = ( r; n), for which any r-partite graph with partite sets of size n and of maximum degree less than has an independent transversal. This value was

Penny E. Haxell; Tibor Szab

2006-01-01

281

Transverse Magnetic Field Propellant Isolator  

NASA Technical Reports Server (NTRS)

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

Foster, John E.

2000-01-01

282

Longitudinal and Transverse Wave Motion  

NSDL National Science Digital Library

These animations show students the nature of particle motion in longitudinal and transverse waves, and how they combine to form the more complex motions seen in water waves and Rayleigh surface waves, a type seen in earthquakes. The animations are accompanied by written explanations.

Dan Russell

283

Rupture Synchronicity in Complex Fault Systems  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

284

The management of chronic rupture of the Achilles tendon: minimally invasive peroneus brevis tendon transfer.  

PubMed

We hypothesised that a minimally invasive peroneus brevis tendon transfer would be effective for the management of a chronic rupture of the Achilles tendon. In 17 patients (three women, 14 men) who underwent minimally invasive transfer and tenodesis of the peroneus brevis to the calcaneum, at a mean follow-up of 4.6 years (2 to 7) the modified Achilles tendon total rupture score (ATRS) was recorded and the maximum circumference of the calf of the operated and contralateral limbs was measured. The strength of isometric plantar flexion of the gastrocsoleus complex and of eversion of the ankle were measured bilaterally. Functional outcomes were classified according to the four-point Boyden scale. At the latest review, the mean maximum circumference of the calf of the operated limb was not significantly different from the pre-operative mean value, (41.4 cm, 32 to 50 vs 40.6燾m, 33 to 46; p = 0.45), and not significantly less than that of the contralateral limb (43.1 cm, 35 to 52; p = 0.16). The mean peak torque (244.6 N, 125 to 367) and the strength of eversion of the operated ankle (149.1 N, 65 to 240) were significantly lower (p < 0.01) than those of the contralateral limb (mean peak torque 289, 145 to 419; strength of eversion: 175.2, 71 to 280). The mean ATRS significantly improved from 58 pre-operatively (35 to 68) to 91 (75 to 97; 95% confidence interval 85.3 to 93.2) at the time of final review. Of 13 patients who practised sport at the time of injury, ten still undertook recreational activities. This procedure may be safely performed, is minimally invasive, and allows most patients to return to pre-injury sport and daily activities. Cite this article: Bone Joint J 2015;97-B:353-7. PMID:25737519

Maffulli, N; Oliva, F; Costa, V; Del Buono, A

2015-03-01

285

Tensile strength of carbyne chains in varied chemical environments and structural lengths.  

PubMed

Carbyne and carbyne-based low-dimensional structures are promising for several applications including ultra-compact circuits and purification devices. Designing any applied carbyne-based structure requires a fundamental understanding of the mechanical strength of carbyne chains with different lengths at different temperatures and operating chemical environment. Here we use molecular dynamics simulations to investigate the strength of carbyne chains with different lengths at different temperatures. A theoretical framework based on statistical mechanics and molecular dynamics results is presented, proving a fast and insightful method for predicting the rupture force and its physical mechanism. The effect of water molecules' interaction is also studied on the mechanical properties and it is shown that both the tensile strength and rupture strain are improved by the water interaction. The results of this work can be used for designing and analyzing the robustness and reliability of various carbyne-based materials and applied devices for varies working conditions. PMID:25148690

Mirzaeifar, Reza; Qin, Zhao; Buehler, Markus J

2014-09-19

286

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

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

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

1990-01-01

287

Geomorphic Signals for Preferred Propagation Direction of Earthquake Ruptures on North Anatolian Fault System, TURKEY  

Microsoft Academic Search

The North Anatolian Fault ruptured in a sequence of large earthquakes between 1939 and 1999, generally progressing from east to west. The 1943 and 1944 ruptures propagated unilateraly in opposite directions. Preliminary analysis of the geomorphology along these ruptures shows distinct differences that may reflect repeated ruptures with similar propagation directions. A persistent preferred propagation direction should produce asymmetric damage

C. Yildirim; O. Dor; T. Rockwell; O. Emre; Y. Ben-Zion; M. Sisk; T. Duman

2005-01-01

288

Early surgery for ruptured cerebral aneurysms: technical note.  

PubMed

We describe a collection of techniques to be considered in the early clipping of ruptured cerebral aneurysms located in the anterior circulation when dealing with the swollen red and scaring brain many times found after craniotomy. PMID:18345441

Sillero, Rafael de Oliveira; Sillero Filho, Valter Jos; Freire, Sylvio de Barros; Sillero, Valter Jos

2007-12-01

289

Stress heterogeneities in earthquake rupture experiments with material contrasts  

NASA Astrophysics Data System (ADS)

We investigate significant heterogeneous stresses along bimaterial interfaces in laboratory and numerical experiments. These stresses, partially induced by model or experimental configuration, affect the supershear transition length and rupture speed, mode and directivity in uniaxial compression tests and dynamic rupture experiments with bimaterial interfaces. Using numerical simulations we show that normal and tangential stresses at the fault are distorted by the different stress-strain relationships of the materials. This distortion leads to altered supershear transition lengths, higher rupture potencies and amplifies the preference for rupture in the direction of slip of the slower and more compliant material. We demonstrate how this stress-distortion can be decreased in laboratory experiments by using larger specimen samples and in numerical models by using periodic boundary conditions.

Langer, Sebastian; Weatherley, Dion; Olsen-Kettle, Louise; Finzi, Yaron

2013-03-01

290

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

PubMed Central

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

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

2015-01-01

291

Surgical treatment options for patella tendon rupture, Part I: Acute.  

PubMed

Patella tendon rupture is a debilitating injury. Prompt diagnosis and treatment is essential to prevent retraction of the patella with subsequent adhesions and quadriceps contractures. In a young patient with an acute rupture, primary repair usually is possible with various methods described to protect the repair. In acute injuries with inadequate tissue, augmentation with hamstring tendons or allograft generally is necessary. Because of the different types of rupture and the possibility for poor quality tissue, the surgeon should always be prepared to combine different techniques to obtain tthe best repair. Continuous passive motion generally can be initiated early with a secure repair. In patients with a patella tendon ruptured that is promptly diagnosed, securely repaired, and followed closely through their rehabilitation, good results can be expected. PMID:16119282

Greis, Patrick E; Holmstrom, Michael C; Lahav, Amit

2005-07-01

292

[Rupture of the left bronchus during intubation by Carlens tube].  

PubMed

The authors report a case of left main bronchus rupture following endotracheal intubation with a Carlens double-lumen tube. The bronchus rupture occurred during a cure of gastro-oesophageal-reflux and resection of oesophageal diverticula through a left thoracotomy. The patient was a 65-year-old woman treated with corticosteroids for an Addison's disease. The weakness of the bronchial wall initiated by the steroid hormones was an important factor contributing to the perforation. There is also a higher risk of rupture during oesophageal surgery because of surgical dissection and stretch on the tracheobronchial airway. This case demonstrates that such a complication can occur without ventilatory failure. A rupture must be recognized and treated surgically very rapidly. Recommendations regarding the use of double-lumen endotracheal tubes are reviewed in order to decrease the occurrence of such a complication. PMID:8092569

Boulanger, V; Papion, H; Jusserand, J; Testart, J; Winckler, C

1994-01-01

293

Rupture of Cylindrical Ice Model and Tuna Fish during Freezing  

NASA Astrophysics Data System (ADS)

The gape and heave produced on the surface of tuna fish during freezing were confirmed by rupture of cylindrical type ice model. The results of experiment were shown as summarized below; 1) in case of restraining the progress of ice formation of model during freezing,any rupture was produced at not only slow freezing but also quick freezing. It was the same as tuna fish; 2) in case of closing surface of ice model covered perfectly by outside shell ice during slow freezing,it was not ruptured at not only ice model but also tuna fish. On the contrary it was cracked at quick freezing not only ice model but also tuna fish; 3) therefore it was confirmed that the rupture of tuna fish during freezing had been easy to produce at quick freezing.

Ogawa, Yutaka; Uno, Mitsuyo

294

Seafloor changes above the Tohoku-Oki earthquake rupture zone  

NASA Astrophysics Data System (ADS)

After a subduction earthquake like the 11 March 2011 Tohoku-Oki earthquake, Earth's crust continues to deform. Scientists have been monitoring this deformation near the earthquake's rupture zone to estimate further seismic hazards.

Orwig, Jessica

2014-12-01

295

Emergency endovascular repair of ruptured visceral artery aneurysms  

E-print Network

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

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

2007-07-02

296

Controls on earthquake rupture and triggering mechanisms in subduction zones  

E-print Network

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

Llenos, Andrea Lesley

2010-01-01

297

Spontaneous Ureteral Rupture Diagnosis and Treatment  

PubMed Central

Rupture of the urinary collecting system associated with perinephric or retroperitoneal extravasation of the urine is an unusual condition and it is commonly associated with renal obstructing disease. Perforation could occur at any level from the calix to the bladder but it is usually seen at the fornices and upper ureter. It may lead to several serious consequences including urinoma, abscess formation, urosepsis, infection, and subsequent irreversible renal impairment. We report a case of a 69-year-old woman who presented at the emergency department of our institution with severe abdominal pain. Due to symptomatology worsening, complete laboratory evaluation was performed and the patient underwent abdominal contrast enhanced computed tomography (CT) evaluation which showed contrast agent extravasation outside the excretory system without any evidence of renal calculi at basal acquisition. It was decided to perform a double-J stent placement which was followed by complete healing of the ureter and its removal was performed 8 weeks later. Diagnosis and therapeutic approaches are discussed. PMID:24455381

Pampana, E.; Altobelli, S.; Morini, M.; Ricci, A.; D'Onofrio, S.; Simonetti, G.

2013-01-01

298

Determination of closure disk rupture parameters  

SciTech Connect

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

Merten, C.W.; Robinson, M.A. (EG and G Mound Applied Technologies, Miamisburg, OH (USA)); Evans, N.A. (Sandia National Labs., Albuquerque, NM (USA))

1990-01-01

299

Creep and creep rupture of rock salt  

SciTech Connect

A fundamental review is given of creep properties and flow processes of experimentally and naturally deformed rocksalt as background pertinent to waste repository design. Deformational behavior of halite single crystals is discussed first, followed by a brief treatment of experimentally deformed artifically prepared halite aggregates. The results of recent extensive quasi-static compression and creep tests on natural aggregates, especially on southeastern New Mexico bedded salt and on Avery Island domal salt, are then reviewed in some detail. The mechanical behavior of these two very different rocksalts is remarkably similar, an observation that provides some confidence to extrapolations of the results to repository condition. The relatively scarce data for accelerating creep and creep-rupture of rocksalt are reviewed, followed by a general treatment of relevant experiments and observations from the Project Salt Vault demonstration. The question of brine migration is then discussed and pertinent observations from flow of rocksalt glaciers and diapirs are reviewed briefly. Recommendations are made for additional fundamental research in various areas and it is concluded, on the basis of all available information, that dry domal salt deposits would provide nearly ideal media for radioactive waste repositories.

Carter, N.L.

1983-06-01

300

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

PubMed

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

Uzun, G黮ay; Keyf, Filiz

2003-04-01

301

Laboratory investigation of the radiative energy transfer during rupture nucleation  

NASA Astrophysics Data System (ADS)

Triaxial compression experiments were performed on several materials (Glass, Granite, Basalt, Sandstone, Marble and Gypsum) at confining pressures ranging from 10 to 100MPa, and from room temperature to 70 degrees C. During each of these experiments, acoustic waves radiated from damage accumulation and fast crack propagation were continuously monitored thanks to a fast acoustic recorder, which enables to obtain continuous acoustogram of rupture nucleation and propagation, without the limitations of former trigger systems. In our experiments, rupture does not need to be slowed down, and the transition from quasi-static nucleation to dynamic propagation has now been systematically investigated.Comparing each material, three main observation can be drawn : - First, the amount of damage accumulation before the dynamic rupture propagation varies from material to material, and also depends on the pressure and temperature conditions. For instance, glass, granites and sandstones are typically materials where the nucleation involves a large amount of cracking prior to rupture. In contrast, rupture in basalt at low confinement is not preceded by any damage accumulation. Finally, pre-rupture damage accumulation can also be purely aseismic, which is the case of marble for instance. - Second, the brittle-ductile transition does not exactly overlaps the aseismic-seismic transition, at least in the conditions at which we performed our experiments. For example, marble deforms plastically beyond 50MPa, and although the deformation is ductile, a large amount of crack accumulates in the rock, which tends to make it unstable. In the same way, acoustic emissions decrease in gypsum with increasing pressure and temperatures. - Finally, the time during which rupture propagates depends largely on the rheology. For instance, and in the case of ductile failures such as in marble, dislocation and twin accumulation is such that cracks propagation steps are small and/or slow, and thus the radiated energy release rate remains small at early stages of rupture and increases with rupture speed. Put together, our observations clearly highlight the dependence of the radiated acoustic (and microseismic?) energy during rupture nucleation and early stages of crack propagation not only on the rupture propagation speed and the slip velocity but most importantly on the rock抯 lithology and rheology.

Schubnel, A. J.; Brantut, N.; Ougier-Simonin, A.; Adelinet, M.; Fortin, J.; Gueguen, Y.

2009-12-01

302

Acoustic investigation of rupture nucleation in the Laboratory  

NASA Astrophysics Data System (ADS)

Triaxial compression experiments were performed on several materials (Glass, Granite, Basalt, Sandstone, Marble and Gypsum) at confining pressures ranging from 10 to 100MPa, and from room temperature to 70 degrees C. During each of these experiments, acoustic waves radiated from damage accumulation and fast crack propagation were continuously monitored thanks to a fast acoustic recorder, which enables to obtain continuous acoustogram of rupture nucleation and propagation, without the limitations of former trigger systems. In our experiments, rupture does not need to be slowed down, and the transition from quasi-static nucleation to dynamic propagation has now been systematically investigated.Comparing each material, three main observation can be drawn : - First, the amount of damage accumulation before the dynamic rupture propagation varies from material to material, and also depends on the pressure and temperature conditions. For instance, glass, granites and sandstones are typically materials where the nucleation involves a large amount of cracking prior to rupture. In contrast, rupture in basalt at low confinement is not preceded by any damage accumulation. Finally, pre-rupture damage accumulation can also be purely aseismic, which is the case of marble for instance. - Second, the brittle-ductile transition does not exactly overlaps the aseismic-seismic transition, at least in the conditions at which we performed our experiments. For example, marble deforms plastically beyond 50MPa, and although the deformation is ductile, a large amount of crack accumulates in the rock, which tends to make it unstable. In the same way, acoustic emissions decrease in gypsum with increasing pressure and temperatures. - Finally, the time during which rupture propagates depends largely on the rheology. For instance, and in the case of ductile failures such as in marble, dislocation and twin accumulation is such that cracks propagation steps are small and/or slow, and thus the radiated energy release rate remains small at early stages of rupture and increases with rupture speed. Put together, our observations clearly highlight the dependence of the radiated acoustic (and microseismic?) energy during rupture nucleation and early stages of crack propagation not only on the rupture propagation speed and the slip velocity but most importantly on the rock's lithology and rheology.

Schubnel, Alexandre; Brantut, Nicolas; Ougier-Simonin, Audrey; Adeliner, Mathilde; Fortin, Jerome; Gueguen, Yves

2010-05-01

303

Composite impact strength improvement through a fiber/matrix interphase  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

304

Rupture of the pectoralis major muscle: Surgical treatment in athletes  

Microsoft Academic Search

Pectoralis major tendon rupture is a relatively rare injury, resulting from violent, eccentric contraction of the muscle.\\u000a Over 50% of these injuries occur in athletes, classically in weight-lifters during the 慴ench press manoeuvre. We present\\u000a 13 cases of distal rupture of the pectoralis major muscle in athletes. All patients underwent open surgical repair. Magnetic\\u000a resonance imaging was used to confirm

R. G. Kakwani; J. J. Matthews; K. M. Kumar; A. Pimpalnerkar; N. Mohtadi

2007-01-01

305

Early radiographic features in patients with anterior cruciate ligament rupture  

Microsoft Academic Search

OBJECTIVETo determine, in a preliminary cross sectional study of patients with anterior cruciate ligament (ACL) ruptured knees, which of the radiographic features梥ubchondral cortical plate thickness, trabecular sclerosis, and osteophytosis梐ppears before or in association with changes in joint space width (JSW) as a surrogate for articular cartilage thickness in patients with ruptured knees.METHODS19 patients (14 men), mean (95% CI) age 28.7

J C Buckland-Wright; J A Lynch; B Dave

2000-01-01

306

Patellar Tendon Ruptures in National Football League Players  

Microsoft Academic Search

Background: Although knee injuries are common among professional football players, ruptures of the patellar tendon are relatively rare. Predisposing factors, mechanisms of injury, treatment guidelines, and recovery expectations are not well established in high-level athletes.Hypothesis: Professional football players with isolated rupture of the patellar tendon treated with timely surgical repair will return to their sport.Study Design: Case series; Level of

Martin Boublik; Theodore Schlegel; Ryan Koonce; James Genuario; Charles Lind; David Hamming

2011-01-01

307

Continuous microwire patterns dominated by controllable rupture of liquid films.  

PubMed

Controllable microwire patterns are prepared by dominating the rupture of liquid films. Regular rhombic-shaped micropillar arrays serve as wetting defects to pin or depin liquids, yielding continuous, herringbone, bead-shaped polystyrene microwire patterns or bead arrays. The results provide a deeper understanding of the controllable rupture of liquid films and offer a general strategy for the organization of polymers into structures needed for wiring, interconnects, and functional devices for future microfabrication. PMID:23161834

Xin, Zhiqing; Su, Bin; Wang, Jianjun; Zhang, Xingye; Zhang, Zhiliang; Deng, Mengmeng; Song, Yanlin; Jiang, Lei

2013-03-11

308

Rupture of Plantaris Muscle - A Mimic: MRI Findings  

PubMed Central

Calf muscle trauma commonly involves the gastrocnemius and soleus muscles. Plantaris muscle is a vestigial muscle coursing through the calf. Similar clinical features may be seen with injury to the plantaris muscle. It can also mimic other conditions like deep vein thrombosis, rupture of Baker's cyst, and tumors. MRI is helpful in identifying and characterizing it. We report two cases of ruptured plantaris muscle seen on MRI. PMID:22616036

Gopinath, T. N.; Jagdish, J.; Krishnakiran, K.; Shaji, P. C.

2012-01-01

309

Rupture of plantaris muscle - a mimic: MRI findings.  

PubMed

Calf muscle trauma commonly involves the gastrocnemius and soleus muscles. Plantaris muscle is a vestigial muscle coursing through the calf. Similar clinical features may be seen with injury to the plantaris muscle. It can also mimic other conditions like deep vein thrombosis, rupture of Baker's cyst, and tumors. MRI is helpful in identifying and characterizing it. We report two cases of ruptured plantaris muscle seen on MRI. PMID:22616036

Gopinath, T N; Jagdish, J; Krishnakiran, K; Shaji, P C

2012-01-01

310

Ruptured abdominal aortic aneurysm diagnosed through non-contrast MRI  

PubMed Central

Rupture of an aneurysm is a rare complication although it is considered a common cause of death. Some of these patients present with the classic triad of symptoms such as abdominal pain, pulsatile abdominal mass and shock. Most symptoms are misleading and will only present as vague abdominal pain. Here we describe one such patient with an unusual presentation of a misleading abdominal mass which was eventually diagnosed as a ruptured abdominal aortic aneurysm after an emergency MRI. PMID:25003065

Chatra, Priyank S

2013-01-01

311

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

PubMed

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

Okuwaki, Ryo; Yagi, Yuji; Hirano, Shiro

2014-01-01

312

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

PubMed Central

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 (0.52.0?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

Okuwaki, Ryo; Yagi, Yuji; Hirano, Shiro

2014-01-01

313

Physically Based Failure Criteria for Transverse Matrix Cracking  

NASA Technical Reports Server (NTRS)

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.

Davila, Carlos G.; Camanho, Pedro P.

2003-01-01

314

Isolated renal pelvis rupture secondary to blunt trauma: Case report  

PubMed Central

Introduction Isolated rupture of the renal pelvis is a very rare condition and thus causes delays in the diagnosis of the rupture. It is most commonly seen in the setting of obstructive ureteric calculus. Other rare causes include neoplasms, trauma, and iatrogenic procedures. Diagnosis is usually established on computed tomography (CT) which demonstrates the extravasation of the contrast in the peripelvic, perinephric, or retroperitoneal collections. Presentation of case A 27-year-old male patient was admitted to our hospital due to multiple traumas associated with motor vehicle accidents. The patient had clear urine output. A large pelvic rupture was detected by abdominal contrast-enhanced CT and after consulting with other departments, emergency repair of the renal pelvis was performed and a ureteral stent was implanted. Discussion Only a few isolated cases of pelvis rupture with resultant extravasation have been reported in the literature. The treatment of pelvic rupture should be preceded by the removal of underlying causes, followed by conservative management. However, surgical intervention should be warranted in the emergency cases presenting with the symptoms that may impede the decision-making process and in the cases whose diagnosis cannot be clarified by radiological techniques. Conclusion Renal pelvic injury must be considered in the differential diagnosis of blunt trauma. Surgical intervention may be necessary in some cases. We present a case who underwent surgery due to isolated renal pelvis rupture caused by blunt abdominal trauma. PMID:25734319

Taken, Kerem; Onc, Mehmet Re?it; Erg黱, M黶l黰; Ery?lmaz, Recep; G黱e?, Mustafa

2015-01-01

315

Volume Fraction Dependence of Droplet Rupturing in Concentrated Nanoemulsions  

NASA Astrophysics Data System (ADS)

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

Meleson, K.

2005-03-01

316

Dynamic rupture modeling with laboratory-derived constitutive relations  

USGS Publications Warehouse

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

Okubo, P.G.

1989-01-01

317

The temporal distribution of seismic radiation during deep earthquake rupture  

USGS Publications Warehouse

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

Houston, H.; Vidale, J.E.

1994-01-01

318

Evidence for Supershear Rupture During the 1906 San Francisco Earthquake  

NASA Astrophysics Data System (ADS)

The 1906 San Francisco earthquake is perhaps the single most important event in the history of earthquake science. Measurements taken and analyzed for that event led to the demonstration of elastic rebound. Despite the importance of this earthquake, the two most recently published source models, one based on seismic data and the other based on geodetic data, are sharply discordant. We suggest the two source models can be reconciled if rupture in the 1906 earthquake exceeded the shear wave velocity. Observations of super-shear rupture in recent large strike-slip earthquakes suggests that it is possible and may even be typical of large strike-slip events. We find that we can fit the geodetic data and the envelope of the seismic data provided the rupture exceeds the shear wave speed to the north of Point Arena. We are analyzing non-repeated triangulation measurements and solving the joint slip/rupture velocity inverse problem to test this hypothesis more rigorously. If supershear rupture in large earthquakes is common, it would be of fundamental importance for understanding the hazard posed by large strike-slip faults in general, and for our understanding seismic hazard in northern California in particular, because so much of our characterization of the hazard in that region is based on our understanding of what happened in 1906. The prediction of strong ground motion in future large strike-slip earthquakes will be profoundly different if earthquake rupture velocity is routinely supershear.

Song, S.; Beroza, G. C.; Segall, P.

2005-12-01

319

Transverse angular momentum of photons  

SciTech Connect

We develop the quantum theory of transverse angular momentum of light beams. The theory applies to paraxial and quasiparaxial photon beams in vacuum and reproduces the known results for classical beams when applied to coherent states of the field. Both the Poynting vector, alias the linear momentum, and the angular-momentum quantum operators of a light beam are calculated including contributions from first-order transverse derivatives. This permits a correct description of the energy flow in the beam and the natural emergence of both the spin and the angular momentum of the photons. We show that for collimated beams of light, orbital angular-momentum operators do not satisfy the standard commutation rules. Finally, we discuss the application of our theory to some concrete cases.

Aiello, Andrea [Max Planck Institute for the Science of Light, Guenter-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany); Marquardt, Christoph; Leuchs, Gerd [Max Planck Institute for the Science of Light, Guenter-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany); Institute for Optics, Information and Photonics, University Erlangen-Nuernberg, Staudtstrasse 7/B2, D-91058 Erlangen (Germany)

2010-05-15

320

Achievable Transverse Cylindrical Electromagnetic Mode  

E-print Network

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

R. Chen; X. Li

2011-06-04

321

Transversity in exclusive meson electroproduction  

E-print Network

In this talk various spin effects in hard exclusive electroproduction of mesons are briefly reviewed and the data discussed in the light of recent theoretical calculations within the frame work of the handbag approach. For electroproduction of positively charged pions it is shown that there is a strong contribution from photon-pion transitions which can be modeled by the transversity GPD H_T accompanied by the twist-3 pion wave function.

P. Kroll

2009-11-06

322

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

323

Do Surface Fault Ruptures Cause More Destruction of Houses?  

NASA Astrophysics Data System (ADS)

Surface fault ruptures accompanying large earthquakes are commonly thought to cause more destruction of houses. In some regions such as California, Utah, and Taiwan, formal regulations are put in place to restrict building of houses on land with known surface fault ruptures. However, the question of whether surface fault ruptures do actually cause more destruction of houses has never been checked by empirical data. In this paper, we use the spatial distribution of the percentage of totally collapsed houses from two destructive earthquakes in central Taiwan to address this question. The first earthquake took place on April 21, 1935 with a magnitude of 7.1. The earthquake was accompanyed by two segments of surface fault ruptures, the NE-SW striking right lateral strike-slip Tun-tze-chiao fault and the N-S striking reverse Shih-tan fault. The second earthquake took place on September 21, 1999 with a magnitude 7.6. The earthquake was acompanyed by the N-S striking thrust Chelungpu fault. We first obtained the percentage of houses totally collapsed as well as the percentage of people killed in each village (sun-li", the smallest administrative district). Then we plot the data on a map to show the spatial distribution patterns of houses collapsed and people killed. The results are summarized as follows: Fault Zone Houses collapsed People killed 1935 Surface ruptures 58.67% 5.85% Tun-tze-chiao S-E side 46.16% 1.82% (Strike-slip ) N-W side 28.47% 1.04% 1935 Surface ruptures 62.19% 1.89% Shih-tan East side 77.21% 0.46% (Reverse) West side 81.59% 1.52% 1999 Surface ruptures 14.54% 0.24% Chelungpu East side 29.41% 0.55% (Thrust) West side 9.73% 0.11% We can see from the table that the surface fault ruptures of the strike-slip Tun-tze-chiao fault did cause more destruction of houses than the outside zones, respectively. In contrary, the surface fault ruptures of the reverse-slip Shih-tan fault and the thrust Chelungpu fault did not cause more destruction of houses than the outside zones. Thus, the building code regulation to restrict building of houses on land with surface fault ruptures apparently is warranted for strike slip faults, but is not necessarily warranted for reverse and thrust faults.

Tsai, Y.; Yu, T.; Lee, C.

2004-12-01

324

STS-93 SSME Nozzle Tube Rupture Investigation  

NASA Technical Reports Server (NTRS)

STS-93 was launched on July 23, 1999. There was an anomaly at the end of the launch in that the main engines shut down 0.16 second early because sensors detected a low level of oxidizer in the LOX tank (actually the duct from the tank to the vehicle). This resulted in a cutoff velocity for the vehicle that was 16 ft/sec low. It should have been 25872 ft/sec. The OMS engines were subsequently used to achieve the proper orbit. An investigation was immediately initiated into the cause of this LOX tank low level cutoff. It was noticed during the launch that the turbine temperatures for Main Engine 3 (E2019) were approximately 100 F higher than the preflight prediction. Linear Engine Model matching of the data indicated that a nozzle leak best fit the data. Post launch review of the data showed, that at approximately five seconds into the start, numerous parameters indicated small anomalous shifts. These shifts were all consistent with a rupture of nozzle tubes. Post launch review of the films showed that just after Space Shuttle Main Engine (SSME) ignition and just prior to liftoff a streak is seen in the exhaust plume of E2019. Just after liftoff the streak can be seen emanating from the nozzle wall. This photo confirmed that a leak was coming from the nozzle tubes. Based on the photo, the axial location of the leak was estimated to be 28 in. from the aft end of the nozzle and in line with nozzle coolant feed line #1. The streak continued to be visible during the launch.

Romine, W. Dennis

1999-01-01

325

Long-Term Creep and Creep Rupture Behavior of Woven Ceramic Matrix Composites  

NASA Technical Reports Server (NTRS)

Tensile creep behavior of SiC/SiNC ceramic matrix composites at elevated temperatures and at various stress levels have been investigated for turbine engine applications. The objective of this research is to present creep behavior of SiC/SiCN composites at stress levels above and below the monotonic proportional limit strength and predict the life at creep rupture conditions. Tensile creep-rupture tests were performed on an Instron 8502 servohydraulic testing machine at constant load conditions up to a temperature limit of 1000 C. Individual creep curves indicate three stages such as primary, secondary, and tertiary. The creep rate increased linearly at an early stage and then gradually became exponential at higher strains. The stress exponent and activation energy were also obtained at 700 and 1000 C. The specimen lifetime was observed to be 55 hrs at 121 MPa and at 700 C. The life span reduced to 35 hrs at 143 MPa and at 1000 C. Scanning electron microscopy observations revealed significant changes in the crystalline phases and creep damage development. Creep failures were accompanied by extensive fiber pullout, matrix cracking, and debonding along with fiber fracture. The creep data was applied to Time-Temperature-Stress superposition model and the Manson-Haferd parametric model for long-time life prediction.

Haque, A.; Rahman, M.; Mach, A.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

2001-01-01

326

Team physician #2. Peroneus brevis transfer for Achilles tendon rupture in athletes.  

PubMed

We feel peroneus brevis transfer is especially advantageous for patients interested in sports. We have used this technique in 55 athletes, and to date there have been no re-ruptures (Table 1). Two patients had mild superficial wound problems which did not affect the end result. This method has advantages in comparison with nonoperative treatment and other operative techniques. The danger of re-rupture is avoided and loss of strength minimized because the tendon transfer adds power to the injured triceps. In addition, the proximal retracted triceps is restored to length and securely repaired under physiological tension. Postoperative immobilization in a short leg cast at a right angle plus early weightbearing facilitate rehabilitation. A prolonged period of rehabilitation requiring many months of treatment has not been necessary. The extended rehabilitation and prolonged incapacity necessary to recover from immobilization in the plantarflexed position have been avoided. Early weightbearing helps prevent calf weakness and atrophy. Transferring the peroneal tendon has not resulted in any biomechanical functional imbalance to the foot. PMID:3174224

Turco, V; Spinella, A J

1988-08-01

327

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

NASA Astrophysics Data System (ADS)

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 (?, 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.

Viesca, Robert C.; Rice, James R.

2012-03-01

328

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

SciTech Connect

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.

Hybertsen M. S.

2013-07-08

329

QCD Evolution of Helicity and Transversity TMDs  

SciTech Connect

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

Prokudin, Alexei [JLAB, Newport News, VA (United States)

2014-01-01

330

Predicting Tensile Strengths of Boron/Aluminum Composites  

NASA Technical Reports Server (NTRS)

To develop predictive theory to account for time/temperature effect of B/A1 composites, series of deformation and fracture studies was performed on commercial boron fibers over wide ranges of stress, stress application time, and temperature. By combining these single fiber results with fracture theory for metal matrix composites, design formulas were derived that describe B/A1 composite tensile and stress rupture strengths as function of time and temperature. Using derived formulas, calculated and experimental results agree to within 3 percent.

Decarlo, J. A.

1982-01-01

331

Vortex dynamics in ruptured and unruptured intracranial aneurysms  

NASA Astrophysics Data System (ADS)

Intracranial aneurysms (IAs) are a potentially devastating pathological dilation of brain arteries that affect 1.5-5 % of the population. Causing around 500 000 deaths per year worldwide, their detection and treatment to prevent rupture is critical. Multiple recent studies have tried to find a hemodynamics predictor of aneurysm rupture, but concluded with distinct opposite trends using Wall Shear Stress (WSS) based parameters in different clinical datasets. Nevertheless, several research groups tend to converge for now on the fact that the flow patterns and flow dynamics of the ruptured aneurysms are complex and unstable. Following this idea, we investigated the vortex properties of both unruptured and ruptured cerebral aneurysms. A brief comparison of two Eulerian vortex visualization methods (Q-criterion and lambda 2 method) showed that these approaches gave similar results in our complex aneurysm geometries. We were then able to apply either one of them to a large dataset of 74 patient specific cases of intracranial aneurysms. Those real cases were obtained by 3D angiography, numerical reconstruction of the geometry, and then pulsatile CFD simulation before post-processing with the mentioned vortex visualization tools. First we tested the two Eulerian methods on a few cases to verify their implementation we made as well as compare them with each other. After that, the Q-criterion was selected as method of choice for its more obvious physical meaning (it shows the balance between two characteristics of the flow, its swirling and deformation). Using iso-surfaces of Q, we started by categorizing the patient-specific aneurysms based on the gross topology of the aneurysmal vortices. This approach being unfruitful, we found a new vortex-based characteristic property of ruptured aneurysms to stratify the rupture risk of IAs that we called the Wall-Kissing Vortices, or WKV. We observed that most ruptured aneurysms had a large amount of WKV, which appears to agree with the current hypothesized biological triggers of pathological remodeling of the artery walls. Having a good natural ratio of statuses in our IA cohort (55 unruptured vs. 19 ruptured), we were able to test the statistical significance of our predictor to fortify our findings. We also performed a distribution analysis of our cohort with respect to the number of WKV to strengthen the encouraging statistical analysis result; both analyses provided a clear good separation of the status of the aneurysms based on our predictor. Lastly, we constructed a receiver operating characteristic (ROC) curve to analyze the power different thresholds of WKV had in splitting the data in a binary way (unruptured/ruptured). The number of WKV was efficaciously able to stratify the rupture status, identifying 84.21 % of the ruptured aneurysms (with 25.45 % of false positives, i.e. unruptured IAs tagged as ruptured) when using a threshold value of 2. Our novel work undertaken to study the vortex structures in IAs brought to light interesting characteristics of the flow in the aneurysmal sac. We found that there are several distinct categories in which the aneurysm vortex topologies can be put in without relationship to the aneurysm rupture status. This first finding was in contradiction with available already-published results. Nonetheless, ruptured IAs had a statistically significant larger amount of WKV as opposed to unruptured aneurysms. This new predictor we propose to the community could very well clear a new path among the currently controversial WSS-based parameters. Although it needs to be improved to be more resilient, the first results obtained by the WKV-based parameter are promising when applied to a large dataset of 74 IAs patient-specific transient CFD simulations.

Trylesinski, Gabriel

332

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

333

Delamination behaviour of GdBCO coated conductor tapes under transverse tension  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

334

Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifting Philosophy  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

335

Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifing Philosophy  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

336

Hemodynamic-Morphologic Discriminants for Intracranial Aneurysm Rupture  

PubMed Central

Background and Purpose To identify significant morphologic and hemodynamic parameters that discriminate intracranial aneurysm (IA) rupture status using 3D angiography and computational fluid dynamics (CFD). Methods 119 IAs (38 ruptured, 81 unruptured) were analyzed from 3D angiographic images and CFD. Six morphologic and seven hemodynamic parameters were evaluated for significance with respect to rupture. Receiver-operating characteristic (ROC) analysis identified area under the curve (AUC) and optimal thresholds separating ruptured from unruptured aneurysms for each parameter. Significant parameters were examined by multivariate logistic regression analysis in 3 predictive models梞orphology only, hemodynamics only, and combined梩o identify independent discriminants, and the AUC-ROC of the predicted probability of rupture status was compared among these models. Results Morphologic parameters (Size Ratio [SR], Undulation Index, Ellipticity Index, and Nonsphericity Index) and hemodynamic parameters (Average Wall Shear Stress [WSS], Maximum intra-aneurysmal WSS, Low WSS Area, Average Oscillatory Shear Index [OSI], Number of Vortices, and Relative Resident Time) achieved statistical significance (p<0.01). Multivariate logistic regression analysis demonstrated SR to be the only independently significant factor in the morphology model (AUC=0.83, 95% confidence interval [CI] 0.750.91), whereas WSS and OSI were the only independently significant variables in the hemodynamics model (AUC=0.85, 95% CI 0.780.93). The combined model retained all three variables, SR, WSS, and OSI (AUC=0.89, 95% CI 0.820.96). Conclusion All three models梞orphological (based on SR), hemodynamic (based on WSS and OSI), and combined梔iscriminate IA rupture status with high AUC values. Hemodynamics is as important as morphology in discriminating aneurysm rupture status. PMID:21106956

Xiang, Jianping; Natarajan, Sabareesh K.; Tremmel, Markus; Ma, Ding; Mocco, J; Hopkins, L. Nelson; Siddiqui, Adnan H.; Levy, Elad I.; Meng, Hui

2010-01-01

337

Interface oxidation and stress-rupture of Nicalon{trademark}/SiC CFCCs at intermediate temperatures  

SciTech Connect

The effect of oxidation of the carbonaceous fiber coating on the intermediate temperature stress-rupture behavior of a Nicalon{trademark}/C/SiC continuous fiber composite was modeled. The model, that was reduced to the analysis of a general ideal bundle composed of classical fibers subjected to constant loading, predicts that the oxidation of the fiber coating triggers a sequence of processes that can lead, under certain conditions, to composite failure. These processes involve loss of stress transfer between the fiber and the matrix, fiber overloading, and fiber failure. The implications of the model predictions are discussed in relation to experimental measurements at 425 C in air that show that Nicalon{trademark}/C/SiC exhibits time-dependent loss of strength.

Lara-Curzio, E.; Ferber, M.K.; Tortorelli, P.F. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1996-10-01

338

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

NASA Astrophysics Data System (ADS)

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

Fletcher, Jon B.; McGarr, A.

2006-03-01

339

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

USGS Publications Warehouse

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

Fletcher, Joe B.; McGarr, A.

2006-01-01

340

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

USGS Publications Warehouse

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

Heaton, T.H.

1990-01-01

341

Transversity in exclusive vector-meson leptoproduction  

E-print Network

The role of transversity or helicity-flip generalized parton distributions (GPDs) in leptoproduction of vector mesons is investigated within the framework of the handbag approach. The transversity GPDs in combination with twist-3 meson wave functions, occur in the amplitudes for transitions from a transversely polarized virtual photon to a longitudinal polarized vector meson. The importance of the transversity GPDs can be examined in some of the spin density matrix elements and in transverse target spin asymmetries. Using suitable parametrizations of both helicity-flip and non-flip GPDs, which are essentially taken from our previous papers, we estimate these observables and compare the results with available data.

S. V. Goloskokov; P. Kroll

2013-10-05

342

Surgical Versus Nonsurgical Treatment of Acute Achilles Tendon Rupture  

PubMed Central

Background: Surgical repair is a common method of treatment of acute Achilles rupture in North America because, despite a higher risk of overall complications, it has been believed to offer a reduced risk of rerupture. However, more recent trials, particularly those using functional bracing with early range of motion, have challenged this belief. The aim of this meta-analysis was to compare surgical treatment and conservative treatment with regard to the rerupture rate, the overall rate of other complications, return to work, calf circumference, and functional outcomes, as well as to examine the effects of early range of motion on the rerupture rate. Methods: A literature search, data extraction, and quality assessment were conducted by two independent reviewers. Publication bias was assessed with use of the Egger and Begg tests. Heterogeneity was assessed with use of the I2 test, and fixed or random-effect models were used accordingly. Pooled results were expressed as risk ratios, risk differences, and weighted or standardized mean differences, as appropriate. Meta-regression was employed to identify causes of heterogeneity. Subgroup analysis was performed to assess the effect of early range of motion. Results: Ten studies met the inclusion criteria. If functional rehabilitation with early range of motion was employed, rerupture rates were equal for surgical and nonsurgical patients (risk difference = 1.7%, p = 0.45). If such early range of motion was not employed, the absolute risk reduction achieved by surgery was 8.8% (p = 0.001 in favor of surgery). Surgery was associated with an absolute risk increase of 15.8% (p = 0.016 in favor of nonoperative management) for complications other than rerupture. Surgical patients returned to work 19.16 days sooner (p = 0.0014). There was no significant difference between the two treatments with regard to calf circumference (p = 0.357), strength (p = 0.806), or functional outcomes (p = 0.226). Conclusions: The results of the meta-analysis demonstrate that conservative treatment should be considered at centers using functional rehabilitation. This resulted in rerupture rates similar to those for surgical treatment while offering the advantage of a decrease in other complications. Surgical repair should be preferred at centers that do not employ early-range-of-motion protocols as it decreased the rerupture risk in such patients. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. PMID:23224384

Soroceanu, Alexandra; Sidhwa, Feroze; Aarabi, Shahram; Kaufman, Annette; Glazebrook, Mark

2012-01-01

343

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

PubMed Central

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 23 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding. PMID:23478602

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

2013-01-01

344

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

PubMed Central

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

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

2014-01-01

345

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

PubMed

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

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

2014-01-01

346

Strength Difference between Clam-Shell and Long-Reach Excavator Constructed Cement-Bentonite Self-Hardening Slurry Walls  

E-print Network

1 Strength Difference between Clam-Shell and Long-Reach Excavator Constructed Cement-Bentonite Self-b transverse shear walls. The two methods tested were a crane-operated mechanical clam-shell excavator (CS

347

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

NASA Astrophysics Data System (ADS)

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

Wei, Meng; McGuire, Jeffrey J.

2014-09-01

348

Why Strength Training?  

MedlinePLUS

... of heart disease and as a therapy for patients in cardiac rehabilitation programs. Research and Background About Strength Training Scientific research has shown that exercise can slow the physiological aging clock. While aerobic ...

349

Earthquake early warning and the physics of earthquake rupture  

NASA Astrophysics Data System (ADS)

One of the great debates in seismology today revolves around the question of whether earthquake ruptures are self-similar, cascading failures, or whether their size is somehow predetermined at the start of the rupture. If earthquakes are self-similar there is theoretically no way to determine the magnitude of an event until the rupture has completely terminated, while if it is deterministic the magnitude should be immediately discernible. Recent advances in Earthquake Early Warning methodologies provide new insight into the fundamental physics of earthquake rupture and highlight the importance of understanding the answer to this question. Observations of the amplitude and frequency content of early P-wave arrivals suggest that some information about the final size of an earthquake is already present within a few seconds of the initiation of rupture, in agreement with a host of other observations that show a degree of scaling between large and small earthquakes. While this suggests that earthquakes are deterministic, there is likewise a large body of work, both observational and model-based, that indicates that this is not true and earthquakes are self-similar. This work documents the process of calibrating and testing the ElarmS Earthquake Early Warning methodology in northern California on the Northern California and Berkeley Digital Seismic Networks. In the process the work adds to the body of observations which show a dependency on event magnitude of P-wave frequency content and amplitude. These observations are corroborated with a new set of independent observations of kinematic slip distributions. These new observations indicate that the early slip on a fault also scales with magnitude and suggest again that earthquakes are not entirely self-similar cascading events. In an effort to assign a physical mechanism to the observations of scaling, both in P-waves and in kinematic slip inversions, a hypothetical model is tested wherein the intensity of the early rupture imparts more or less energy to the rupture front and affects the likelihood of the rupture continuing or dying out in the face of unfavorable conditions further along the fault plane. The results of testing this hypothesis are somewhat equivocal, but they are suggestive of the likely truth, that earthquakes exhibit aspects of both deterministic and cascading rupture to some degree. Understanding the details of the interplay between these two aspects is crucial to the successful application of Earthquake Early Warning systems, especially in rare large earthquakes for which there is little empirical data on the performance of these systems.

Wurman, Gilead

350

Fe II oscillator strengths  

Microsoft Academic Search

Oscillator strengths of 124 Fe II lines in the wavelength range 220-540 nm were obtained from wall-stabilized arc and hollow-cathode measurements. By a combination of hook and emission measurements it was possible to determine a large set of relative oscillator strengths of Fe II lines without any assumptions concerning the plasma state of the light sources used. The relative f-values

S. Kroll; M. Kock

1987-01-01

351

Spontaneous rupture of hepatic hemangiomas: A review of the literature  

PubMed Central

Hepatic hemangiomas are congenital vascular malformations, considered the most common benign mesenchymal hepatic tumors, composed of masses of blood vessels that are atypical or irregular in arrangement and size. Hepatic hemangiomas can be divided into two major groups: capillary hemangiomas and cavernous hemangiomas These tumors most frequently affect females (80%) and adults in their fourth and fifth decades of life. Most cases are asymptomatic although a few patients may present with a wide variety of clinical symptoms, with spontaneous or traumatic rupture being the most severe complication. In cases of spontaneous rupture, clinical manifestations consist of sudden abdominal pain, and anemia secondary to a haemoperitoneum. Disseminated intravascular coagulopathy can also occur. Haemodynamic instability and signs of hypovolemic shock appear in about one third of cases. As the size of the hemangioma increases, so does the chance of rupture. Imaging studies used in the diagnosis of hepatic hemangiomas include ultrasonography, dynamic contrast-enchanced computed tomography scanning, magnetic resonance imaging, hepatic arteriography, digital subtraction angiography, and nuclear medicine studies. In most cases hepatic hemangiomas are asymptomatic and should be followed up by means of periodic radiological examination. Surgery should be restricted to specific situations. Absolute indications for surgery are spontaneous or traumatic rupture with hemoperitoneum, intratumoral bleeding and consumptive coagulopathy (Kassabach-Merrit syndrome). In a patient presenting with acute abdominal pain due to unknown abdominal disease, spontaneous rupture of a hepatic tumor such as a hemangioma should be considered as a rare differential diagnosis. PMID:21191518

Jr, Marcelo AF Ribeiro; Papaiordanou, Francine; Gon鏰lves, Juliana M; Chaib, Eleazar

2010-01-01

352

Ruptures of the anterior cruciate ligament in soccer.  

PubMed

Ruptures of the anterior cruciate ligament (ACL) are serious, common and costly injuries. The present 12-year investigation was undertaken to examine the frequency of ACL ruptures and identify the game events that may have contributed to the cause of these injuries in male soccer players across a French district. A retrospective questionnaire was used to record the players' age at the time of injury, laterality, standard of play, playing position and injured side. The characteristics of the injury situations were described in detail to investigate the game events involved in each case. A total of 934 ruptures was reported. Significantly more ruptures were sustained in a non-contact versus a contact situation (p<0.01). Of the total number of lesions, 34.5% occurred during a pivot action. The right knee was affected more than the left knee (p<0.001), irrespective of the dominant side of the player. Certain game events reported in the injury situations were shown to be related to player's age, standard and position. While these results have confirmed observations from previous investigations on ACL ruptures in soccer, the analysis of a considerably larger number of injury cases has brought new findings to the literature as well as recommendations for future research. PMID:19199222

Rochcongar, P; Laboute, E; Jan, J; Carling, C

2009-05-01

353

Robustness Tests for Reliably Determining the Earthquake Rupture Process  

NASA Astrophysics Data System (ADS)

Problems related to the determination of the earthquake rupture process details from analysis of body-wave seismograms was first discussed by Kostrov in 1974. We discuss how to use robustness tests to identify the reliable properties of the rupture process obtained from inversion of broadband body wave data (Das and Kostrov, JGR 1990; PEPI 1994). We then interpret the results for the following submarine subduction zone earthquakes: the Mw 8.0 Andreanof Islands earthquake (Das and Kostrov, ibid.), the Mw 8.2 Biak, Indonesia earthquake (Das et al., JGR, 2000) and the Mw 8.4 2001 Peru earthquake (Robinson et al., Science, 2006), in terms of subducting seafloor features and its influence on the earthquake rupture process. In particular, subducting seamounts appear to be affecting the rupture process of all these great earthquakes. The question of how much of a seamount still remains after it is subducted to be able to affect the earthquake rupture on the subduction plane will be addressed.

Das, S.; Robinson, D.

2007-12-01

354

Factors affecting formation and rupture of intracranial saccular aneurysms.  

PubMed

Unruptured intracranial aneurysms represent a decisional challenge. Treatment risks have to be balanced against an unknown probability of rupture. A better understanding of the physiopathology is the basis for a better prediction of the natural history of an individual patient. Knowledge about the possible determining factors arises from a careful comparison between ruptured versus unruptured aneurysms and from the prospective observation and analysis of unbiased series with untreated, unruptured aneurysms. The key point is the correct identification of the determining variables for the fate of a specific aneurysm in a given individual. Thus, the increased knowledge of mechanisms of formation and eventual rupture of aneurysms should provide significant clues to the identification of rupture-prone aneurysms. Factors like structural vessel wall defects, local hemodynamic stress determined also by peculiar geometric configurations, and inflammation as trigger of a wall remodeling are crucial. In this sense the study of genetic modifiers of inflammatory responses together with the computational study of the vessel tree might contribute to identify aneurysms prone to rupture. The aim of this article is to underline the value of a unifying hypothesis that merges the role of geometry, with that of hemodynamics and of genetics as concerns vessel wall structure and inflammatory pathways. PMID:24306170

Bacigaluppi, S; Piccinelli, M; Antiga, L; Veneziani, A; Passerini, T; Rampini, P; Zavanone, M; Severi, P; Tredici, G; Zona, G; Krings, T; Boccardi, E; Penco, S; Fontanella, M

2014-01-01

355

Spontaneous ureteric rupture secondary to an invasive desmoid tumour  

PubMed Central

INTRODUCTION Spontaneous ureteric rupture is a rare entity that presents as an extravasation of urine from the ureter without previous surgery, ureteric manipulation and external trauma of the ureter. We report the case of a desmoid tumour presenting as spontaneous ureteric rupture which was managed in our institution. PRESENTATION OF CASE A 28 years old healthy male presented with a four day history of generalised abdominal pain secondary to spontaneous right ureteric rupture. Patient was initially managed via insertion of nephrostomy tube and antibiotics. After unsuccessful attempts of retrograde and antegrade ureteric stent insertion, patient was subsequently managed via elective surgical intervention. The excised specimen revealed desmoid tumour as cause of the ureteric rupture. DISCUSSION Desmoid tumours are rare benign tumours arising from fascial or musculoaponeurotic structures that do not metastasise, but tend to invade locally. It is often initially managed medically prior to undertaking a definitive surgical intervention. To our knowledge this is the first reported case of ureteric perforation secondary to a desmoid tumour of the mesentery. CONCLUSION Spontaneous rupture of the ureter is often misdiagnosed as other conditions. History taking and examination can be unreliable, hence a high level of suspicion and further investigations should be utilised. Once the diagnosis is made, treatment can be individualised based on aetiology. PMID:25460442

Yoon, Peter Daechul; Ahmadi, Nariman; Strahan, Stephen; Wang, Audrey

2014-01-01

356

Composite Overwrapped Pressure Vessels (COPV) Stress Rupture Test  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

357

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

USGS Publications Warehouse

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.

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

2002-01-01

358

Distal biceps brachii tendon rupture resulting in acute compartment syndrome.  

PubMed

Distal biceps brachii tendon rupture is an uncommon injury. Compartment syndrome of the upper arm is rarely described in the literature. The diagnosis of upper arm compartment syndrome requires a high index of suspicion, and emergent surgical treatment with fasciotomy in the acute setting is necessary to avoid devastating neurovascular complications. This article reports a case of acute compartment syndrome of the anterior compartment of the upper arm after a complete rupture of the distal biceps brachii tendon. A healthy 45-year-old man presented with increasing arm pain; paresthesia in the lateral antebrachial cutaneous nerve distribution; and a tense, swollen anterior compartment of his upper arm. Side port catheter absolute pressure measurement was 83 mm Hg with a diastolic blood pressure of 92 mm Hg. The patient underwent an emergent fasciotomy and was found to have a complete rupture of his distal biceps brachii tendon. He subsequently underwent distal biceps tendon repair and delayed primary closure of his incision. Postoperatively, his paresthesia improved and he has no neurological deficit. There is a paucity of case reports describing compartment syndrome after rupture of either the proximal or distal end of the biceps brachii tendon, and none of the reports describe compartment syndrome of the upper arm after rupture of the distal biceps tendon. This article highlights an unusual complication of an uncommon injury and reviews diagnostic and treatment principles for the management of acute compartment syndrome of the upper arm. PMID:24200459

Grandizio, Louis C; Suk, Michael; Feltham, Glen T

2013-11-01

359

Creep rupture of a tropical wood polymer composite  

NASA Astrophysics Data System (ADS)

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.

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

360

Transverse SSA in inclusive DIS  

NASA Astrophysics Data System (ADS)

We analyze the transverse single spin asymmetry (SSA) in inclusive deep inelastic scattering (DIS), which requires a two-photon exchange to generate a non-zero effect. We present numerical results for the SSA that allow us to comment on the so-called "sign mismatch" issue invloving the Efremov-Teryaev-Qiu-Sterman (ETQS) function TF(x,x). In particular, we discuss how our results indicate a collinear twist-3 Sivers-type effect may not be the main cause of the SSAs seen in proton-proton (pp) collisions.

Pitonyak, Daniel

2013-10-01

361

A Transversely Isotropic Thermoelastic Theory  

NASA Technical Reports Server (NTRS)

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.

Arnold, S. M.

1989-01-01

362

On the transverse Beltrami equation  

SciTech Connect

Let (M, T{sub 1,0} (M)) be a CR manifold (of hypersurface type) where (1) T{sub 1,0}(M) denotes its CR structure (of CR dimension N). Let {mu} be a pointwise C-anti-linear endomorphism of T{sub 1,0}(M). Let (T{sub 1}, ..., T{sub N}) be a (local) frame of T{sub 1,0}(M) and consider the first order PDE (with variable coefficients): T{sub J}{line_integral} = {mu}{sub j}{sup l}T{sub l}{line_integral} where {mu}T{sub j} = {mu}{sub j}{sup l}T{sub l}. This is the Beltrami equation, cf. the terminology of A. Koranyi & H.M. Reimann. Next, assume that P {improper_subset} K er {mu}, so that {mu} descends to an endomorphism of H. Finally, if we restrict ourselves to basic unknown functions {line_integral} {element_of} {Omega}{sub B}{sup 0} (F) i.e. {line_integral} is constant along each leaf of (F) then (1) may be written as (2) {zeta}{sub {alpha}}({line_integral}) = {mu}{sub {alpha}}{sup {beta}} {zeta}{sub {beta}} ({line_integral}). This makes sense for an arbitrary CR foliation (F), of a C{sup {infinity}} manifold M, endowed with a C-anti-linear endomorphism {mu} of its transverse CR structure, and is invariant under a change of admissible frame. We refer to (2) as the (transverse) Beltrami equation of (M, F). We use the theory of CR foliations to show that the components of an automorphism {phi} preserving the transverse contact structure of a given embedded strictly pseudoconvex CR foliation satisfy (2) where {mu} is the complex dilatation of {phi} and conversely. For transversally Heisenberg CR foliations we use the results in sections 2 and 3 to characterize K-quasiconformality of a foliation automorphism. 10 refs.

Barletta, E. [Basilicate Univ., Potenza (Italy)

1996-12-31

363

Optical Isolators With Transverse Magnets  

NASA Technical Reports Server (NTRS)

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.

Fan, Yuan X.; Byer, Robert L.

1991-01-01

364

Transverse Echo Measurements in RHIC  

SciTech Connect

Diffusion counteracts cooling and the knowledge of diffusion rates is important for the calculation of cooling times and equilibrium beam sizes. Echo measurements are a potentially sensitive method to determine diffusion rates, and longitudinal measurements were done in a number of machines. We report on transverse echo measurements in RHIC and the observed dependence of echo amplitudes on a number of parameters for beams of gold and copper ions, and protons. In particular we examine the echo amplitudes of gold and copper ion bunches of varying intensity, which exhibit different diffusion rates from intrabeam scattering.

Fischer, Wolfram [Brookhaven National Laboratory, Upton, New York 11973 (United States)

2006-03-20

365

TRANSVERSE ECHO MEASUREMENTS IN RHIC.  

SciTech Connect

Diffusion counteracts cooling and the knowledge of diffusion rates is important for the calculation of cooling times and equilibrium beam sizes. Echo measurements are a potentially sensitive method to determine diffusion rates, and longitudinal measurements were done in a number of machines. We report on transverse echo measurements in RHIC and the observed dependence of echo amplitudes on a number of parameters for beams of gold and copper ions, and protons. In particular they examine the echo amplitudes of gold and copper ion bunches of varying intensity, which exhibit different diffusion rates from intrabeam scattering.

FISCHER, W.

2005-09-18

366

Micromechanical modeling of fiber\\/matrix interface effects in transversely loaded SiC\\/Ti6-4 metal matrix composites  

Microsoft Academic Search

The transverse tensile behavior of a unidirectional SiC-fiber\\/Ti-6Al-4V-matrix composite is analyzed, with emphasis on the fiber-matrix interface strength, using Nimmer's (1990) model. Idealizing the composite as a regular rectangular array of fibers in an elastoplastic matrix, the transverse tensile stress-strain behavior is predicted assuming an infinitely strong interface as well as an interface without tensile strength. Good agreement was obtained

R. P. Nimmer; R. J. Bankert; E. S. Russell; G. A. Smith; P. KENNARD Wright

1991-01-01

367

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

PubMed Central

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

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

2014-01-01

368

Apple Strength Issues  

SciTech Connect

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

Syn, C

2009-12-22

369

Rupture of latissimus dorsi muscle in a tennis player.  

PubMed

Spontaneous rupture of the latissimus dorsi muscle is a rare injury, and few reported cases were avulsion injuries at their humeral insertion. Seven cases of spontaneous rupture of the latissimus dorsi muscle have been reported, but only 1 occurred at the myotendinous junction. The mechanism of this injury is reported to be forceful resisted arm adduction or extension, and reported injuries were rock climbing and attempting to pull up on an overhead handhold, waterskiing injury during pull-up with ski rope, overuse in golf in the leading arm, and abduction-external rotation with horizontally extended arm during a professional steer wrestling performance. The latissimus dorsi muscle is not a critical muscle for activities of daily living; however, the significance of the muscle is increased in professional or elite athletes. This article presents a case of rupture of the latissimus dorsi muscle at the myotendinous junction that occurred during a sports activity. PMID:19225999

Park, Jin-Young; Lhee, Sang-Hoon; Keum, Jeong-Sup

2008-10-01

370

Rupture Zones of Strong Earthquakes In The Corinth Rift  

NASA Astrophysics Data System (ADS)

Ruptures zones of the strong (M 8805; 6) earthquakes that occurred in the Corinth rift in the last three hundred years have been determined on the basis of aftershock epi- central distributions , intensity distributions and observations regarding seismogenic ground failures and tsunamis. The space U time distribution of the rupture zones indi- cates that (1) for time intervals of about 50yrs the rupture zones do not overlap; over- alpping appear, however, in longer time intervals , (2) there is a trend of the seismic activity to decrease westwards , and (3) particular regions constitute potential seis- mic gaps , like the Kiato UXylocastro region in the south coast of the Corinth Gulf, where the large 1402 earthquake occurred, and the Livadia U Desfina region where the A.D.361 and 551 large earthquakes possibly took place.

Papadopoulos, G. A.; Kouskouna, V.; Plessa, A.

371

A Case of Ruptured Splenic Artery Aneurysm in Pregnancy  

PubMed Central

Background. Rupture of a splenic artery aneurysm is rare complication of pregnancy that is associated with a significant maternal and fetal mortality. Case. A multiparous female presented in the third trimester with hypotension, tachycardia, and altered mental status. A ruptured splenic artery aneurysm was discovered at the time of laparotomy and cesarean delivery. The patient made a full recovery following resection of the aneurysm. The neonate survived but suffered severe neurologic impairment. Conclusion. The diagnosis of ruptured splenic artery aneurysm should be considered in a pregnant woman presenting with signs of intra-abdominal hemorrhage. Early intervention by a multidisciplinary surgical team is key to preserving the life of the mother and fetus. PMID:25574408

Corey, Elizabeth K.; Harvey, Scott A.; Sauvage, Lynnae M.; Bohrer, Justin C.

2014-01-01

372

Evaluating fault rupture hazard for strike-slip earthquakes  

USGS Publications Warehouse

We present fault displacement data, regressions, and a methodology to calculate in both a probabilistic and deterministic framework the fault rupture hazard for strike-slip faults. To assess this hazard we consider: (1) the size of the earthquake and probability that it will rupture to the surface, (2) the rate of all potential earthquakes on the fault (3) the distance of the site along and from the mapped fault, (4) the complexity of the fault and quality of the fault mapping, (5) the size of the structure that will be placed at the site, and (6) the potential and size of displacements along or near the fault. Probabilistic fault rupture hazard analysis should be an important consideration in design of structures or lifelines that are located within about 50m of well-mapped active faults.

Petersen, M.; Cao, T.; Dawson, T.; Frankel, A.; Wills, C.; Schwartz, D.

2004-01-01

373

Transcatheter Arterial Embolization for Spontaneous Rupture of the Omental Artery  

SciTech Connect

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

Matsumoto, Tomohiro, E-mail: t-matsu@koto.kpu-m.ac.jp [Kyoto First Red Cross Hospital, Department of Radiology (Japan); Yamagami, Takuji [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science (Japan); Morishita, Hiroyuki; Iida, Shigeharu; Tazoe, Jun; Asai, Shunsuke; Masui, Koji [Kyoto First Red Cross Hospital, Department of Radiology (Japan); Ikeda, Jun [Kyoto First Red Cross Hospital, Departments of Surgery and Emergency (Japan); Nagata, Akihiro [Kyoto First Red Cross Hospital, Department of Pathology (Japan); Sato, Osamu [Kyoto First Red Cross Hospital, Department of Radiology (Japan); Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science (Japan)

2011-02-15

374

[Diagnosis and treatment of the ruptured Achilles tendon].  

PubMed

The treatment of the recently ruptured Achilles tendon can be conservative or surgical. The conservative treatment may be carried out using either a static cast immobilisation or using a dynamic brace and an early functional rehabilitation. The surgical technique can be either open or mini-invasive. Neglected and ancient ruptures may need to be treated surgically by a tendinoplasty. There is an ongoing discussion about how to manage the recently ruptured Achilles tendon, especially since recent descriptions of conservative-functional treatment procedures and mini-invasive surgical techniques. We present the choice of the different treatment options and the clinical reasoning to identify the best adapted treatment for the individual patient. The ideal treatment option depends on the functional demand and the medical condition of the patient. PMID:22912999

Neumayer, F; Assal, M; Crevoisier, X

2012-07-25

375

Emergency Stenting of a Ruptured Infected Anastomotic Femoral Pseudoaneurysm  

SciTech Connect

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

Klonaris, Chris, E-mail: chris_klonaris@yahoo.com; Katsargyris, Athanasios; Matthaiou, Alexandros; Giannopoulos, Athanasios; Tsigris, Chris; Papadopouli, Katerina ['LAIKON' Hospital, Athens University Medical School, 1st Department of Surgery, Vascular Division (Greece); Tsiodras, Sotiris [Attikon Hospital, Athens University Medical School, 4th Academic Department of Internal Medicine (Greece); Bastounis, Elias ['LAIKON' Hospital, Athens University Medical School, 1st Department of Surgery, Vascular Division (Greece)

2007-11-15

376

[Neglected ipsilateral simultaneous ruptures of patellar and quadriceps tendon].  

PubMed

Neglected patellar and quadriceps tendon rupture is a rare injury, but ipsilateral simultaneous patellar and quadriceps tendon rupture was not described in the literature to our knowledge. In this article, we report a 40-year-old healthy male patient with neglected ipsilateral patellar and quadriceps tendon ruptures treated by peroneus longus tendon autograft. Patient had received some conservative and surgical treatments for patellar fracture before applying to our clinic. After our treatment using peroneus longus autograft and interference nails, patient was immobilized for six weeks in cylindrical cast. Flexion exercises and full weight bearing were started after cast removal. Patient had no complaint at postoperative second year. Patient was a neglected case. Surgical repair and early rehabilitation enabled us to achieve a satisfactory outcome. PMID:25741921

Karahasano?lu, ?lker; Yolo?lu, Osman; Kerimo?lu, Servet; Turhan, Ahmet U?ur

2015-04-01

377

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

NASA Astrophysics Data System (ADS)

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

Suter, Max

2015-01-01

378

Clinical Characteristics and Surgical Problems of Ruptured Globe Injury?  

PubMed Central

Background Ocular trauma is a major cause of vision loss, especially in the young patients, and is the leading cause of unilateral blind in China. Objective The aims of this report are to analyze ciliary and choroidal lesion characteristics and outcomes of a group of patients with ruptured globe injuries and discuss finding a more effective treatment protocol. Here we report our experience treating ruptured globe injuries. Methods Seventy-five patients (75 eyes) with a diagnosis of ruptured globe injuries were selected from 264 patients with open globe injuries at the Shierming Eye Hospital of Shandong Province between January 2009 and December 2011. General information and clinical characteristics such as ciliary and choroidal lesion features were reviewed. Results Of the 75 patients, 85.3% were men, and the average age of the patients was 37.2 years (range, 663 years). The right eye was injured in 52.0%; enucleation was performed in 9 patients. There was no light perception, in the final corrected visual acuity in another 3 patients. The ratio of better visual acuity (better than 0.1) increased from 0 preoperatively to 16.0% postoperatively. Among the 75 patients with ruptured globe injuries, 13 had ciliary injury and 47 (62.7%) had choroidal injuries. Both ciliary and choroidal injuries were detected in 15 patients. Retinal tissue incarceration during sclera suturing was usually the vital point leading to unfavorable results. Conclusions Ruptured globe injury usually results in severe visual acuity damage. Active treatment could help to restore visual acuity in patients to some degree. Some effective treatment protocols for ruptured globe injuries could be followed. Some unsuitable procedures in primary treatment should be avoided to achieve a better prognosis. PMID:24385006

Bi, Hongsheng; Cui, Yan; Li, Yang; Wang, Xingrong; Zhang, Jianhua

2013-01-01

379

Rapid aneurysm growth and rupture in systemic lupus erythematosus  

PubMed Central

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

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

2015-01-01

380

Improved results of surgical management of postinfarction ventricular septal rupture.  

PubMed

Fifty-five patients had surgical repair of postinfarction ventricular septal rupture in Massachusetts General Hospital from 1968 through 1981. In patients operated more than three weeks after infarction, hospital survival has been 93% (14/15). Before 1975 in patients operated less than three weeks after infarction, hospital survival was 41% (7/17). In this same era patents operated for septal rupture with cardiogenic shock present before operation had a hospital survival rate of only 27% (3/11). Before 1975 patients with cardiogenic shock were supported with intra-aortic balloon pumping (IABP) and vasopressors, and operation deferred pending hemodynamic stabilization. Before 1975 patients with anterior septal rupture had a hospital survival rate of 64% (9/14), while patients with posterior septal rupture had a hospital survival rate of only 38% (5/13). This difference in survival according to the location of septal rupture occurred despite comparable numbers of patients in each group requiring early operation, as well as incidence of cardiogenic shock. Since January 1, 1975 patients operated less than three weeks after infarction have had an overall hospital survival rate of 70% (16/23). Of the 10 most recent patients operated early, nine are survivors. In patients with anterior defects 85% (11/13) survived, while in patients with posterior defects 67% survived (10/15). In patients operated with cardiogenic shock present before operation, survival has been 67% (10/15). Changes in management leading to improved results include (1) immediate operation for patients with cardiogenic shock, (2) cold cardioplegic protection of the myocardium, and (3) prosthetic replacement of posterior left ventricular free wall defect, after infarctectomy and septal repair, in patients with posterior septal rupture. PMID:7114934

Daggett, W M; Buckley, M J; Akins, C W; Leinbach, R C; Gold, H K; Block, P C; Austen, W G

1982-09-01

381

Association of Hemodynamic Characteristics and Cerebral Aneurysm Rupture  

PubMed Central

Background and purpose Hemodynamic factors are thought to play an important role in the initiation, growth and rupture of cerebral aneurysms. This report describes a study of the associations between qualitative intra-aneurysmal hemodynamics and the rupture of cerebral aneurysms. Methods 210 consecutive aneurysms were analyzed using patient-specific CFD simulations under pulsatile flow conditions. The aneurysms were classified into categories depending on the complexity and stability of the flow pattern, size of the impingement region, and inflow concentration by two blinded observers. A statistical analysis was then performed with respect to history of previous rupture. Inter-observer variability analysis was performed. Results Ruptured aneurysms were more likely to have complex flow patterns (83%, p<0.001), stable flow patterns (75%, p=0.0018), 66% concentrated inflow (66%, p=<0.0001), and small impingement regions (76%, p=0.0006) compared to unruptured aneurysms. Inter-observer variability analyses indicate that all the classifications performed are in very good agreement, i.e. well within the 95% confidence interval. Conclusions A qualitative hemodynamic analysis of cerebral aneurysms using image based patient-specific geometries has shown that concentrated inflow jets, small impingement regions, complex flow patterns, and unstable flow patterns are correlated with a clinical history of prior aneurysm rupture. These qualitative measures provide a starting point for more sophisticated quantitative analysis aimed at assigning aneurysm risk of future rupture. These analyses highlight the potential for CFD to play an important role in the clinical determination of aneurysm risks. PMID:21051508

Cebral, Juan R.; Mut, Fernando; Weir, Jane; Putman, Christopher M.

2011-01-01

382

Damage-enhanced creep and creep rupture in fiber composites  

SciTech Connect

Creep in fiber composites at high temperatures is an important phenomenon that can lead to accelerated failure in several different ways. For systems with matrix creep rates larger than those of the fibers, creep transfers load onto the fibers and the fibers undergo progressive damage under the increasing load. This leads to enhanced composite creep rates, relative to non-breaking fibers, in both ceramic and metal matrix composites. In metal composites, creep rupture can then occur by excessive damage accumulation even in the absence of explicit high-temperature fiber degradation mechanisms. In ceramic composites, creep rupture occurs following fiber degradation such as slow crack growth, a process accelerated by the enhanced stress on the fibers. Here, these phenomena are discussed within the framework of the composite model of Curtin, which is generalized to include creep and creep rupture. The model generally accounts for the statistical evolution of fiber damage and for the interfacial slip between fibers and matrix that occur in both CMC and MMC materials, both of which can be functions of time at elevated temperatures. Application of the theory to creep rupture in titanium matrix composites reinforced with SiC fibers shows good agreement with experimental results for creep rates and failure times versus applied load. Application to creep rupture in ceramic matrix composites in which the fibers undergo slow crack growth demonstrates the dependence of lifetime on load and crack growth rate. A much longer lifetime for composites, as compared to the lifetime of individual fibers tested in the laboratory, is demonstrated; this is a result of the small effective gauge length of fibers in the composite relative to the typical gauge lengths tested in single fiber stress rupture tests.

Curtin, W.A.; Fabeny, B.; Iyengar, N. [Virginia State Univ., Blacksburg, VA (United States)

1995-12-31

383

The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2)  

USGS Publications Warehouse

California?s 35 million people live among some of the most active earthquake faults in the United States. Public safety demands credible assessments of the earthquake hazard to maintain appropriate building codes for safe construction and earthquake insurance for loss protection. Seismic hazard analysis begins with an earthquake rupture forecast?a model of probabilities that earthquakes of specified magnitudes, locations, and faulting types will occur during a specified time interval. This report describes a new earthquake rupture forecast for California developed by the 2007 Working Group on California Earthquake Probabilities (WGCEP 2007).

2007 Working Group on California Earthquake Probabilities

2008-01-01

384

Early aortic valve cusp rupture in relapsing polychondritis.  

PubMed

Aortic regurgitation associated with relapsing polychondritis usually occurs late in the disease as a result of aortic root dilatation. A case where aortic regurgitation occurred early and was due to cusp rupture with a normal aortic root is reported. The patient required urgent aortic valve replacement within six weeks of developing a murmur despite apparent control of inflammation with immunosuppressive treatment. The possibility of cusp rupture with sudden haemodynamic deterioration should be considered in patients with relapsing polychondritis who develop aortic regurgitation. PMID:1575597

Marshall, D A; Jackson, R; Rae, A P; Capell, H A

1992-03-01

385

Ruptured Valsalva Sinus Aneurysm to Pericardium Simulated Aortic Root Dissection  

PubMed Central

Ruptured valsalva sinus aneurysm to pericardium is a rare condition. Here, we described a case presented with tamponade. Initially, hemopericardium was partially drained and then, imaging evaluations were done. Transesophageal echocardiography showed limited dissection of aortic sinus and CT angiography of the ascending aorta showed deformed dilated right coronary sinus. Besides, surgery showed that windsock tract of the right coronary sinus had ruptured into the pericardium with avulsed right coronary aortic cusp. This case indicated a rare cause of cardiac tamponade and insufficiency of imaging modalities for making an accurate diagnosis. PMID:24936486

Davarpasand, Tahereh; Hosseinsabet, Ali; Abassi, Kumars; Arzhan, Sorya

2014-01-01

386

Spontaneous Liver Rupture After Treatment With Drug-Eluting Beads  

SciTech Connect

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

Ritter, C. O., E-mail: ritter@roentgen.uni-wuerzburg.de [University of Wuerzburg, Institute of Radiology (Germany); Wartenberg, M.; Mottok, A. [University of Wuerzburg, Institute of Pathology (Germany); Steger, U. [University of Wuerzburg, Department of General, Visceral, Vascular, and Pediatric Surgery (Germany); Goltz, J. P.; Hahn, D.; Kickuth, R. [University of Wuerzburg, Institute of Radiology (Germany)

2012-02-15

387

Shock-Wave Theory for Rupture of Rubber  

NASA Astrophysics Data System (ADS)

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

Marder, M.

2005-01-01

388

Spontaneous liver rupture after treatment with drug-eluting beads.  

PubMed

Spontaneous rupture of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is a rare and life-threatening complication. Pathophysiologic mechanisms are not yet fully known; it is suggested that rupture is preceded by reactive tissue edema and intratumerous bleeding, leading to a rapid expansion of tumour mass with risk of extrahepatic bleeding in the case of subcapsular localisation. This case report discusses a sudden, unexpected lethal complication in a 74爕ear-old male patient treated with TACE using DC Bead loaded with doxorubicin (DEBDOX) in a progressive multifocal HCC. PMID:21431968

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

2012-02-01

389

Right atrial free wall rupture after blunt chest trauma.  

PubMed

We report the case of an 18-year-old man, victim of a car accident, presenting with severe hypotension and signs of cardiac tamponade. Transoesophageal echocardiography was suggestive of right atrial free wall rupture. The patient underwent urgent cardiac surgery for repair of right atrial rupture. The immediate clinical outcome was favourable; the patient is in good general condition at 24-month follow-up. The right atrium is rarely involved in cardiac contusion as compared to the right ventricle or other cardiac structures, owing to its anatomical location and direction of physical forces. PMID:17906483

De Maria, Elia; Gaddi, Oscar; Navazio, Alessandro; Monducci, Igor; Tirabassi, Giovanni; Guiducci, Umberto

2007-11-01

390

Renal allograft transplant recipient with ruptured hydatid native kidney  

PubMed Central

Echinococcosis of the kidneys in a renal transplant recipient is extremely rare and its occurrence being related to immunosuppression is a possibility which needs further characterisation. Ruptured renal hydatid in a renal transplant recipient is not reported so far to our best knowledge. We present a 42-year-old renal allograft receipient who presented one year after transplant with left flank pain, palpable left lumbar mass and gross hydatiduria. Investigations revealed a ruptured native hydatid kidney. Patient was managed with a combination of chemotherapy and left native nephrectomy and discharged in a satisfactory condition. PMID:25125908

Bhat, Riyaz Ahmad; Wani, Imtiyaz; Khan, Imran; Wani, Muzaffar

2014-01-01

391

Rupture process at the beginning of the 2007 Chuetsu-oki, Niigata, Japan, earthquake  

NASA Astrophysics Data System (ADS)

The rupture process at the beginning stage of the 2007 Chuetsu-oki, Niigata, Japan, earthquake (MW 6.6) is investigated by analyzing P-wave records from local strong-motion stations. The P-wave portion of the near-source strong-motion records shows about 2 s of small but increasing amplitude arrival (so-called "initial rupture phase") followed by the onset of the main energy release ("main rupture phase"). Two issues are addressed in this paper: (1) where the initial rupture process occurred and (2) where the seismic energy corresponding to the main rupture phase was released at the primary stage of the main rupture. The first issue is addressed by locating the main rupture onset position, and the second issue is then approached by introducing a method for mapping the wave energy onto plausible fault planes. Eventually, the following were revealed. The rupture initiated and propagated on the NW-dipping plane, which is a nodal plane of the focal mechanism solution. At 2.1 s after rupture initiation the subsequent main rupture started at a position of approximately 4 km away, southwestward and updipward from the hypocenter. The main rupture at this stage has two possible rupture planes: the same plane as the initial rupture plane, and the conjugated plane, which shares the main rupture onset point with the initial rupture plane. Although it is difficult to determine which plane was actually ruptured at the primary stage of the main rupture, we found that the possible areas radiating strong wave energy on the two possible planes, which could correspond to the first asperity of this earthquake, are located between the hypocenter and the Kashiwazaki-Kariwa nuclear power plant.

Takenaka, H.; Yamamoto, Y.; Yamasaki, H.

2009-02-01

392

Rupture of a highly stretchable acrylic dielectric elastomer Matt Pharr, Jeong-Yun Sun, and Zhigang Suo  

E-print Network

and are susceptible to rupture. Here we carry out an experimental study of the rupture behavior of membranes availability.1,5,19 Despite its popularity, the only investigation of rupture of VHB is that of by Schmidt et

393

Spontaneous Zone III rupture of the flexor tendons of the ulnar three digits in elderly Korean farmers.  

PubMed

Spontaneous flexor tendon rupture is a rare condition and the aetiology is not clear. We report 12 elderly Korean farmers with spontaneous flexor tendon ruptures. We found the rupture in the dominant hand in ten patients. A rupture in the little finger was found in all 12 patients (seven with both flexor tendons ruptured and five with only the profundus ruptured), in the ring finger in four patients (the profundus ruptured in all and both flexor tendons in two patients), and in the middle finger a partial rupture of the profundus in one patient. The tendons were ruptured close to the hook of the hamate. Repetitive friction between the flexor tendons and the hamate hook may cause the ruptures. The hamate hook was excised and the ruptured profundus tendons were reconstructed with tendon transfers with quite favourable functional recovery at follow-up of 1 to 2 years. The ruptured superficialis tendons were not reconstructed. Level of Evidence IV. PMID:25005564

Lee, G J; Kwak, S; Kim, H K; Ha, S H; Lee, H J; Baek, G H

2015-03-01

394

The impact of Vitamin C supplementation in pregnancy and in-vitro upon fetal membrane strength and remodeling  

PubMed Central

Generation of reactive-oxygen species (ROS) has been suggested as a mechanism of fetal membrane (FM) weakening leading to rupture, particularly with preterm premature rupture of the fetal membranes (preterm PROM). In vitro, FM incubation with Tumor necrosis factor (TNF) mimics physiological FM weakening, concomitant with generation of ROS and collagen remodeling. Proinflammatory cytokines are also postulated to have a role in the development of the FM physiological weak zone where rupture normally initiates in term gestations. We hypothesized that antioxidant treatment may block ROS development and resultant FM weakening. Two studies examining antioxidant effects upon FM strength were conducted, one in vivo and the other in vitro. FM of patients enrolled in a multicenter placebo-controlled trial to determine the effect of Vitamin C (1 gm/day) and Vitamin E (400IU/day) upon complications of preeclampsia were examined for FM biomechanical properties and biochemical remodeling at birth. Separately, biomechanics and biochemical markers of remodeling were determined in FM fragments incubated with TNF with or without Vitamin C pre-incubation. Supplemental dietary Vitamin C in combination with Vitamin E did not modify rupture strength, work to rupture, or MMP9 (protein or activity) either within or outside the term FM physiological weak zone. In vitro, TNF decreased FM rupture strength by 50% while increasing MMP9 protein. Vitamin C did not inhibit these TNF-induced effects. Vitamin C alone had a weakening effect on FM in vitro. We speculate that vitamin C supplementation during pregnancy will not be useful in the prevention of preterm PROM. PMID:20581351

Mercer, Brian M.; Abdelrahim, Adli; Moore, Robert M.; Novak, Jillian; Kumar, Deepak; Mansour, Joseph M.; Perez-Fournier, Marina; Milluzzi, Cynthia J.; Moore, John J.

2010-01-01

395

Transverse-longitudinal integrated resonator  

DOEpatents

A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

Hutchinson, Donald P. (Knoxville, TN); Simpson, Marcus L. (Knoxville, TN); Simpson, John T. (Knoxville, TN)

2003-03-11

396

High strength alloys  

DOEpatents

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

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

2010-08-31

397

High strength alloys  

DOEpatents

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

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

2012-06-05

398

Prestressed Ceramic Coatings for Enhanced Reliability of Silicon Wafer Fracture Strength  

Microsoft Academic Search

The objective of this paper is to investigate thin, solid, prestressed ceramic films as a means of enhancing the reliability of silicon semiconductor wafers stressed in bending. To characterize the effect of thin films on strength, one-micrometer ceramic films were deposited on wafers using plasma-enhanced chemical-vapor deposition. The modulus of rupture (MOR) of the coated wafers was determined from four-point

Karl Yoder; Mike Dwyer; N. D'Souza

2007-01-01

399

Structural and biomechanical characteristics after early mobilization in an Achilles tendon rupture model: operative versus nonoperative treatment.  

PubMed

Acute Achilles tendon ruptures are common sports injuries; however, treatment remains a clinical challenge. Studies show a superior effect of early mobilization and full weight bearing on tendon healing and clinical outcome; however, few data exist on structural and biomechanical characteristics in the early healing phase. This study investigated the histological and biomechanical characteristics of early mobilization and full weight bearing in an Achilles tendon rupture model. Eighty rats underwent dissection of a hindpaw Achilles tendon; 40 rats were treated conservatively and 40 underwent open repair of the transected Achilles tendon by suturing. Early mobilization and full weight bearing were allowed in both groups. At 1, 2, 4, and 8 weeks after tenotomy, tensile strength, stiffness, thickness, tissue characteristics (histological analysis), and length were determined. Dissected Achilles tendons healed in all animals during full weight-bearing early mobilization. One and 2 weeks after tenotomy, rats in the operative group showed increased tensile strength and stiffness compared with the nonoperative group. Repair-site diameters were increased at 1, 2, and 8 weeks after tenotomy. Tendon length was decreased in the operative group throughout observation, whereas the nonoperative group showed increased structural characteristics on the cellular level and a more homogeneous collagen distribution. Surgical treatment of dissected rat Achilles tendons showed superior biomechanical characteristics within the first 2 weeks. Conservative treatment resulted in superior histological findings but significant lengthening of the tendon in the early healing phase (weeks 1-8). PMID:22955406

Krapf, Daniel; Kaipel, Martin; Majewski, Martin

2012-09-01

400

Transverse Mode Evolution in a Free Electron Laser Oscillator.  

NASA Astrophysics Data System (ADS)

Focusing of light by the electron beam in a Free Electron Laser has been predicted for several years. In a high gain system, complete cancellation of diffractive spreading within the interaction region may be possible, resulting in an optical beam that can be guided and amplified for many tens of meters. Until now, no direct experimental evidence for FEL self-focusing has existed in support of the theory. In this dissertation I report measurements made of transverse mode evolution in the Stanford Photon Research Lab Free Electron Laser oscillator--the Mark III. Transverse mode characteristics were obtained by sampling the beam in the far field with small apertures which could be positioned freely in the transverse plane. Time-resolved signals received by the sampling system were analyzed to infer mode changes that occur in the laser between small signal, where the influence of the electron beam is strongest, and saturation, where the gain has fallen to cavity loss levels. The data indicate that intracavity focusing of the light occurs in small signal, and diminishes as the laser approaches saturation. After the light decouples from the electrons at the end of the current pulse, symmetric transverse oscillations are observed in the ringdown, providing evidence of residual focusing in saturation. The data are compared to theory in the form of an FEL simulation code. Agreement between data and theory is found for both the change of the strength of self-focusing between small signal and saturation, and for the characteristics of the ringdown oscillations observed in the Mark III FEL. It is concluded that self-focusing occurs at the level and in the form expected by theory, providing experimental support for the theory of optical guiding.

La Sala, John Edward

1987-09-01

401

The Quadriga Effect Revisited: Designing a 揝afety Incision to Prevent Tendon Repair Rupture and Gap Formation in a Canine Model In Vitro  

PubMed Central

Loss of experimental animals due to tendon repair failure results in the need for additional animals to complete the study. We designed a relief proximal to the flexor digitorum profundus (FDP) tendon repair site to serve as a 搒afety incision to prevent repair site ruptures and maximize safety incision-to-suture strength. The FDP tendons were dissected in 24 canine forepaws. The 2nd and 5th tendons were lacerated at the proximal interphalangeal joint level and sutured using a modified Kessler technique and peripheral running suture. Tendon width was measured where the FDP tendon separates into each individual digit and a safety incision, equal to the 2nd and 5th tendon widths, was performed 3, 4, or 5 mm (Groups 1, 2, and 3) proximal to the separation. The tendons were pulled at a rate of 1 mm/s until either the 搒afety incision ruptured or the repair failed. There was no gap formation at the repair site in Groups 1 and 2. However, all Group 3 tendons failed by repair site rupture with the safety incision intact. An adequate safety incision to protect repair gap and rupture and maintain tendon tension for the FDP animal model should be about 4 mm from where the FDP tendon separates. PMID:20872585

Giambini, Hugo; Ikeda, Jun; Amadio, Peter C.; An, Kai-Nan; Zhao, Chunfeng

2012-01-01

402

14 CFR 25.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

403

14 CFR 25.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2014 CFR

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

2014-01-01

404

14 CFR 23.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

405

14 CFR 25.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

406

14 CFR 25.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

407

14 CFR 23.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

408

14 CFR 23.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

409

14 CFR 25.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

410

14 CFR 23.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

411

14 CFR 23.1453 - Protection of oxygen equipment from rupture.  

Code of Federal Regulations, 2014 CFR

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

2014-01-01

412

ANL/ALCF/ESP-13/8 Using Multi-scale Dynamic Rupture Models to  

E-print Network

under contract DE-AC02-06CH11357. The Laboratory's main facility is outside Chicago, at 9700 South Cass seismic hazard results, including a state-wide extended earthquake rupture forecast with rupture

Kemner, Ken

413

TRANSVERSE POLARIZATION DISTRIBUTION AND FRAGMENTATION FUNCTIONS  

SciTech Connect

The authors discuss transverse polarization distribution and fragmentation functions, in particular, T-odd functions with transverse momentum dependence, which might be relevant for the description of single transverse spin asymmetries. The role of intrinsic transverse momentum in the expansion in inverse powers of the hard scale is elaborated upon. The sin {phi} single spin asymmetry in the process e {rvec p} {r_arrow} e{prime} {pi}{sup +} X as recently reported by the HERMES Collaboration is investigated, in particular, by using the bag model.

BOER,D.

2000-04-11

414

Investigations on bolted connections for high strength steel members  

Microsoft Academic Search

A series of tests on 25 bolted connections have been carried out using 17.5 mm thick plates of widths between 108 and 180 mm cut out of the web of a HE 800 B high-strength steel beam.The two M27 grade 10.9 bolts provided in the transverse direction for all the connections have also been provided with different spacings to observe

R. Puthli; O. Fleischer

2001-01-01

415

Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

416

Simultaneous Endovascular Treatment of Ruptured Cerebral Aneurysms and Vasospasm  

PubMed Central

Objective The management of patients with ruptured cerebral aneurysms and severe vasospasm is subject to considerable controversy. We intended to describe herein an endovascular technique for the simultaneous treatment of aneurysms and vasospasm. Materials and Methods A series of 11 patients undergoing simultaneous endovascular treatment of ruptured aneurysms and vasospasm were reviewed. After placement of a guiding catheter within the proximal internal carotid artery for coil embolization, an infusion line of nimodipine was wired to one hub, and of a microcatheter was advanced through another hub (to select and deliver detachable coils). Nimodipine was then infused continuously during the coil embolization. Results This technique was applied to 11 ruptured aneurysms accompanied by vasospasm (anterior communicating artery, 6 patients; internal carotid artery, 2 patients; posterior communicating and middle cerebral arteries, 1 patient each). Aneurysmal occlusion by coils and nimodipine-induced angioplasty were simultaneously achieved, resulting in excellent outcomes for all patients, and there were no procedure-related complications. Eight patients required repeated nimodipine infusions. Conclusion Our small series of patients suggests that the simultaneous endovascular management of ruptured cerebral aneurysms and vasospasm is a viable approach in patients presenting with subarachnoid hemorrhage and severe vasospasm. PMID:25598688

Cho, Young Dae; Ahn, Jun Hyong; Jung, Seung Chai; Kim, Chang Hun; Kang, Hyun-Seung; Kim, Jeong Eun; Lim, Jeong Wook

2015-01-01

417

Spontaneous postpartum rupture of an intact uterus: a case report.  

PubMed

Rupture of uterus is an obstetrical complication characterized by a breach in the uterine wall and the overlying serosa. We report an unusual case of spontaneous rupture of an unscarred uterus in a 33-year-old woman, a day after her third successful vaginal delivery. A 33-year-old pregnant woman, gravid 3, para 3, was referred to our department at 39 gestational week because of rupture of membranes. Despite tocolysis administration, her pregnancy was delivered vaginally after 2 days, giving birth to a male neonate of 3,020 g with normal Apgar scores at first and fifth minute. Her uterus was intact and gynecological examination after delivery was normal without any potential signs or symptoms of pathology. However, the day following her labor, patient complained of left iliac fossa pain. Her blood tests revealed a CRP value at 27.6 mg/L, whereas the X-rays revealed an extensive impacted fecal mass in the colon. MRI revealed that the left lower myometrial part of the uterus was depicted abrupt, with simultaneous presence of hemorrhagic stuff. The decision of laparotomy was therefore made in order to further evaluate rupture of uterus and properly treat patient. And subtotal hysterectomy was performed. Postoperative follow-up period was not characterized by any complications and patient was finally discharged 4 days after hysterectomy. PMID:25368704

Mavromatidis, George; Karavas, George; Margioula-Siarkou, Chrysoula; Petousis, Stamatios; Kalogiannidis, Ioannis; Mamopoulos, Apostolos; Rousso, David

2015-01-01

418

Anterolateral rupture of popliteal cysts in rheumatoid arthritis  

Microsoft Academic Search

Popliteal cysts occur commonly in both normal and arthritic knees. Most cysts are formed by distension of the medially situated semimembranosus bursa. Popliteus bursa distension occurs uncommonly as a lateral popliteal cyst. Two cases of rupture of lateral cysts which produced symptoms related to the anterolateral lower leg are reported. The difficulty of diagnosing the condition because of this unusual

B Kirkham; M Churchill; B Dasgupta; L Wedderburn; J Spencer; D G Macfarlane

1991-01-01

419

INTERNAL RUPTURE OF BONDED RUBBER CYLINDERS IN TENSION  

Microsoft Academic Search

An unusual rupture process is described. It consists of the sudden ; appearance of internal cracks in bonded rubber cylinders at a well-defined and ; comparatively small tensile load. The cracks occur in all the vulcanizates ; examined, and in particularly weak rubbers are found to cause failure. Their ; appearance may also lead to marked cbanges in the load-deflection

A. N. Gent; P. B. Lindley

1959-01-01

420

Tsunami early warning using earthquake rupture duration Anthony Lomax1  

E-print Network

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

Rawlinson, Nick

421

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

ERIC Educational Resources Information Center

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

Milewski, Patrice

2008-01-01

422

Orthopedic pitfalls in the ED: Achilles tendon rupture  

Microsoft Academic Search

Achilles tendon rupture is a relatively uncommon occurrence in a general ED population. The history can be subtle, and physical findings may not be clear-cut. Prompt diagnosis and treatment of these injuries, however, is important to improved clinical outcome. The emergency physician needs to remain vigilant for this diagnosis to avoid this orthopedic pitfall. This review article examines the clinical

Jacob Ufberg; Richard A. Harrigan; Thomas Cruz; Andrew D. Perron

2004-01-01

423

Spontaneous rupture of intercostal artery after severe cough.  

PubMed

Pleural or abdominal hematomas induced by spontaneous rupture of intercostal artery are very rare but can often cause fatal problems leading to hypovolemic shock. Spontaneous rupture of intercostal artery mostly occurs in association with neurofibromatosis type 1, coarctation of aorta, or trauma. In the absence of these conditions, there are very few cases. We report a 39-year-old man who complained of left flank pain after severe cough for a few days. His final diagnosis was hematoma of the left lateral abdominal wall induced by rupture of the left 11th intercostal artery. He was treated immediately by transarterial embolization. Without any serious problems during hospitalization, he was discharged. This case indicates that, in generally healthy individuals, even mild physical force such as cough can lead to rupture of the intercostal artery. Although it is very rare, injury to the intercostal artery should be considered when patients complain of unexplained chest pain, abdominal pain, or flank pain after strong cough or sneezing. PMID:25085284

Jang, Jee Yong; Lim, Yong Su; Woo, Jae Hyug; Jang, Jae Ho

2015-01-01

424

Complications of splenic artery aneurysm other than intraperitoneal rupture.  

PubMed

Thirty-eight patients with aneurysms of the splenic artery were identified in the records of 11 years, but only one aneurysm was ruptured. Portal hypertension was found in nine patients (24%); in two of these the reaction surrounding the aneurysm prevented the construction of a patent splenorenal shunt or caused compartmented portal hypertension. One aneurysm encountered during the survey period and another encountered just after its conclusion ruptured into the stomach. There was a twofold overrepresentation of multiparous women. Intraperitoneal rupture is rare, except in pregnancy. If elective therapy is considered, angiography should be performed. Exclusion or resection of the aneurysm is advocated only for patients with symptomatic or ruptured aneurysms or (very rare) large aneurysms and for women of childbearing age. The spleen should be preserved, when possible. In high-risk patients occlusion of the aneurysm via an intra-arterial catheter should be considered. If the splenic artery aneurysm causes compartmented portal hypertension, splenectomy is indicated; if portal hypertension is general, the form of portasystemic decompression chosen should avoid the region of the aneurysm. PMID:7058498

de Vries, J E; Schattenkerk, M E; Malt, R A

1982-02-01

425

Ruptured pulmonary hydatid cyst with anaphylactic shock and pneumothorax.  

PubMed

Hydatid cyst is a disease caused by a parasitic tapeworm, Echinococcus granulosus, and most commonly involves liver and lung. Ruptured pulmonary hydatid cyst can present a diagnostic challenge, and radiograph can be inconclusive. Anaphylactic reaction is a rare complication of ruptured pulmonary hydatid cyst. A 22-year-old male came to our emergency department in shock with symptoms of shortness of breath and altered mental status from the previous day. Radiograph showed a thin-walled circular translucent area in the right upper lung field, which was misdiagnosed as pneumothorax, and an intercostal chest tube was inserted. After 5 days, repeat radiograph revealed a cavity with an air/fluid level. The chest tube was removed and contrast-enhanced computed tomogram showed a cavity with water-lily sign, which suggests ruptured hydatid cyst. Immunoglobin-G enzyme-linked immunosorbent assay for Echinococcus was positive. The patient responded well to treatment with crystalloid infusion, supplemental oxygen, and albendazole, and then underwent surgery. Anaphylactic reaction due to rupture of a hydatid cyst is rare, but hydatid disease should be suspected in patients from areas where Echinococcus is endemic. PMID:21333077

Shameem, Mohammad; Akhtar, Jamal; Bhargava, Rakesh; Ahmed, Zuber; Khan, Nafees Ahmad; Baneen, Ummul

2011-06-01

426

Advances in the surgical repair of ruptured abdominal aortic aneurysms  

Microsoft Academic Search

Over the past two decades, the mortality rate for elective repair of infrarenal abdominal aortic aneurysms has improved to an acceptable level (<5%). However, surgical results of ruptured abdominal aortic aneurysms have remained fairly constant with about 50% in hospital mortality rates. Growing experience with the use of the left retroperitoneal exposure for elective aortic surgery allowed the authors to

R. C Darling; J. A Cordero; B. B Chang; D. M Shah; P. S. K Paty; W. E Lloyd; R. P Leather

1996-01-01

427

Anthrax toxin-induced rupture of artificial lipid bilayer membranes  

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

428

Rupture of abdominal aortic aneurysm previously treated by endovascular stentgraft  

Microsoft Academic Search

We describe a case of abdominal aortic aneurysm (AAA) with rupture 16 months after treatment by an endograft. A 76-year-old patient on Coumadin after aortic valve replacement had initially successful exclusion by stentgraft. There was no evidence of an endoleak seven months after stentgraft repair, although a computed tomography scan detected an enlargement of the aneurysm sac. Sixteen months after

Giovanni B. Torsello; Eckhard Klenk; Bernd Kasprzak; Thomas Umscheid

1998-01-01

429

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

SciTech Connect

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

Ham, J.E.

1996-01-04</