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Sample records for tube-in-tube slip joint

  1. Avoiding leakage flow-induced vibration by a tube-in-tube slip joint

    SciTech Connect

    Mulcahy, T.M.

    1985-01-01

    Parameters and operating conditions (a stability map) were determined for which a specific slip-joint design did not cause self-excited lateral vibration of the two cantilevered, telescoping tubes forming the joint. The joint design featured a localized annular constriction. Flowrate, modal damping, tube engagement length, and eccentric positioning were among the parameters tested. Interestingly, all self-excited vibrations could be avoided by following a simple design rule: place constrictions only at the downstream end of the annular region between the tubes. Also, overall modal damping decreased with increased flowrate, at least initially, for upstream constrictions while the damping increased for downstream constrictions.

  2. Avoiding leakage flow-induced vibration by a tube-in-tube slip joint

    SciTech Connect

    Mulcahy, T.M.

    1984-10-01

    Parameters and operating conditions (a stability map) were determined for which a specific slip-joint design did not cause self-excited lateral vibration of the two cantilevered, telescoping tubes forming the joint. The joint design featured a localized annular constriction. Flowrate, modal damping, tube engagement length, and eccentric positioning were among the parameters tested. Interestingly, all self-excited vibrations could be avoided by following a simple design rule: place constrictions only at the downstream end of the annular region between the tubes. Also, overall modal damping decreased with increased flowrate, at least initially, for upstream constrictions while the damping increased for downstream constrictions.

  3. Truss Slip Joint

    NASA Technical Reports Server (NTRS)

    Thomas, Frank

    1993-01-01

    Truss slip joint has few parts, strong, and assembled and disassembled easily. Designed to carry axial loads as large as 100,000 lb and to accommodate slight initial axial-displacement and angular misalignments. Joint assembled or disassembled by astronaut in space suit or, on Earth, by technician in heavy protective clothing; simple enough to be operable by robot. Modified to accommodate welding.

  4. Assembly of carbon tube-in-tube nanostructures

    NASA Astrophysics Data System (ADS)

    Su, D. S.; Zhu, Z. P.; Liu, X.; Weinberg, G.; Wang, N.; Schlögl, R.

    2005-09-01

    Tube-in-tube carbon nanostructures were prepared by reorganization of graphitic impurity nanoparticles outside or inside of the pristine carbon nanotubes. Graphitic impurity nanoparticles were first disintegrated into small graphene fragments by a chemical oxidation with nitric acid, which also modifies the graphene fragments with carboxyl and hydroxyl groups at their edges. The functionalized graphene fragments were then reintegrated outside or inside of pristine carbon nanotubes to construct into tube-in-tube nanostructures. The combination of oxidatively functionalized graphene units, their solvate in a polar organic medium allowing for dispersive forces to effect supramolecular organization with carbon nanotubes acting as templates and their polycondensation by acid-catalysed esterification followed by pyrolysis of the oxygen functionalities lead to complex nanostructures inaccessible by direct synthesis.

  5. Conceptual optimization using genetic algorithms for tube in tube structures

    SciTech Connect

    Pârv, Bianca Roxana; Hulea, Radu; Mojolic, Cristian

    2015-03-10

    The purpose of this article is to optimize the tube in tube structural systems for tall buildings under the horizontal wind loads. It is well-known that the horizontal wind loads is the main criteria when choosing the structural system, the types and the dimensions of structural elements in the majority of tall buildings. Thus, the structural response of tall buildings under the horizontal wind loads will be analyzed for 40 story buildings and a total height of 120 meters; the horizontal dimensions will be 30m × 30m for the first two optimization problems and 15m × 15m for the third. The optimization problems will have the following as objective function the cross section area, as restrictions the displacement of the building< the admissible displacement (H/500), and as variables the cross section dimensions of the structural elements.

  6. Stick-slip friction and wear of articular joints

    PubMed Central

    Lee, Dong Woog; Banquy, Xavier; Israelachvili, Jacob N.

    2013-01-01

    Stick-slip friction was observed in articular cartilage under certain loading and sliding conditions and systematically studied. Using the Surface Forces Apparatus, we show that stick-slip friction can induce permanent morphological changes (a change in the roughness indicative of wear/damage) in cartilage surfaces, even under mild loading and sliding conditions. The different load and speed regimes can be represented by friction maps—separating regimes of smooth and stick-slip sliding; damage generally occurs within the stick-slip regimes. Prolonged exposure of cartilage surfaces to stick-slip sliding resulted in a significant increase of surface roughness, indicative of severe morphological changes of the cartilage superficial zone. To further investigate the factors that are conducive to stick-slip and wear, we selectively digested essential components of cartilage: type II collagen, hyaluronic acid (HA), and glycosaminoglycans (GAGs). Compared with the normal cartilage, HA and GAG digestions modified the stick-slip behavior and increased surface roughness (wear) during sliding, whereas collagen digestion decreased the surface roughness. Importantly, friction forces increased up to 2, 10, and 5 times after HA, GAGs, and collagen digestion, respectively. Also, each digestion altered the friction map in different ways. Our results show that (i) wear is not directly related to the friction coefficient but (ii) more directly related to stick-slip sliding, even when present at small amplitudes, and that (iii) the different molecular components of joints work synergistically to prevent wear. Our results also suggest potential noninvasive diagnostic tools for sensing stick-slip in joints. PMID:23359687

  7. Stick-slip friction and wear of articular joints.

    PubMed

    Lee, Dong Woog; Banquy, Xavier; Israelachvili, Jacob N

    2013-02-12

    Stick-slip friction was observed in articular cartilage under certain loading and sliding conditions and systematically studied. Using the Surface Forces Apparatus, we show that stick-slip friction can induce permanent morphological changes (a change in the roughness indicative of wear/damage) in cartilage surfaces, even under mild loading and sliding conditions. The different load and speed regimes can be represented by friction maps--separating regimes of smooth and stick-slip sliding; damage generally occurs within the stick-slip regimes. Prolonged exposure of cartilage surfaces to stick-slip sliding resulted in a significant increase of surface roughness, indicative of severe morphological changes of the cartilage superficial zone. To further investigate the factors that are conducive to stick-slip and wear, we selectively digested essential components of cartilage: type II collagen, hyaluronic acid (HA), and glycosaminoglycans (GAGs). Compared with the normal cartilage, HA and GAG digestions modified the stick-slip behavior and increased surface roughness (wear) during sliding, whereas collagen digestion decreased the surface roughness. Importantly, friction forces increased up to 2, 10, and 5 times after HA, GAGs, and collagen digestion, respectively. Also, each digestion altered the friction map in different ways. Our results show that (i) wear is not directly related to the friction coefficient but (ii) more directly related to stick-slip sliding, even when present at small amplitudes, and that (iii) the different molecular components of joints work synergistically to prevent wear. Our results also suggest potential noninvasive diagnostic tools for sensing stick-slip in joints.

  8. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMINES USING A SPINNING TUBE-IN-TUBE REACTOR

    EPA Science Inventory

    The high purity, high throughput synthesis of a number of imines (Schiff bases) using a spinning tube-in-tube reactor (STT, Kreido Laboratories, Camarillo, CA) has been carried out. The STT reactor allows the high throughput production of high purity imines from a wide variety of...

  9. EPOXIDATION OF SMALL ORGANIC MOLECULES USING A SPINNING TUBE-IN-TUBE REACTOR

    EPA Science Inventory

    The commodity-scale epoxidation of several organic molecules has been carried out using a Spinning Tube-in-Tube (STTr) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Process Intensification, a...

  10. PROGRESS IN PROCESS INTENSIFICATION: SYNTHESIS OF IMIDAZOLE DERIVATIVES USING A SPINNING TUBE-IN-TUBE REACTOR

    EPA Science Inventory

    The high purity, high throughput synthesis of a number of imidazole derivatives using a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California) has been carried out. The STT® reactor allows the high throughput production of high purity imidazole derivativ...

  11. Hysteresis modeling of clamp band joint with macro-slip

    NASA Astrophysics Data System (ADS)

    Qin, Zhaoye; Cui, Delin; Yan, Shaoze; Chu, Fulei

    2016-01-01

    Clamp band joints are commonly used to connect spacecrafts with launch vehicles. Due to the frictional slippage between the joint components, hysteresis behavior might occur at joint interfaces under cyclic loading. The joint hysteresis will bring friction damping into the launching systems. In this paper, a closed-form hysteresis model for the clamp band joint is developed based on theoretical and numerical analyses of the interactions of the joint components. Then, the hysteresis model is applied to investigating the dynamic response of a payload fastened by the clamp band joint, where the nonlinearity and friction damping effects of the joint is evaluated. The proposed analytical model, which is validated by both finite element analyses and quasi-static experiments, has a simple form with sound accuracy and can be incorporated into the dynamic models of launching systems conveniently.

  12. Performance of multi tubes in tube helically coiled as a compact heat exchanger

    NASA Astrophysics Data System (ADS)

    Nada, S. A.; El Shaer, W. G.; Huzayyin, A. S.

    2014-12-01

    Multi tubes in tube helically coiled heat exchanger is proposed as a compact heat exchanger. Effects of heat exchanger geometric parameters and fluid flow parameters; namely number of inner tubes, annulus hydraulic diameter, Reynolds numbers and input heat flux, on performance of the heat exchanger are experimentally investigated. Different coils with different numbers of inner tubes, namely 1, 3, 4 and 5 tubes, were tested. Results showed that coils with 3 inner tubes have higher values of heat transfer coefficient and compactness parameter (bar{h} Ah ). Pressure drop increases with increasing both of Reynolds number and number of inner tubes. Correlations of average Nusselt number were deduced from experimental data in terms of Reynolds number, Prandtl number, Number of inner coils tubes and coil hydraulic diameter. Correlations prediction was compared with experimental data and the comparison was fair enough.

  13. Investigation of Turn-of-Nut Method for Slip-Critical Joints of Aluminum Using A325 Bolts

    SciTech Connect

    Luttrell, C R

    1998-01-01

    Slip-critical bolted joints will be used to join aluminum bridge deck sections by Reynolds Metals Company (RMC). To help ensure that a joint does not slip the proper bolt clamping force to achieve what is known as a friction connection must be determined.

  14. COMMODITY SCALE SYNTHESIS OF 1-METHYLIMIDAZOLE BASED IONIC LIQUIDS USING A SPINNING TUBE-IN-TUBE REACTOR

    EPA Science Inventory

    The continuous large-scale preparation of several 1-methylimidazole based ionic liquids was carried out using a Spinning Tube-in-Tube (STT) reactor (manufactured by Kreido Laboratories). This reactor, which embodies and facilitates the use of Green Chemistry principles and Proce...

  15. Flow chemistry: intelligent processing of gas-liquid transformations using a tube-in-tube reactor.

    PubMed

    Brzozowski, Martin; O'Brien, Matthew; Ley, Steven V; Polyzos, Anastasios

    2015-02-17

    reactive gas in a given reaction mixture. We have developed a tube-in-tube reactor device consisting of a pair of concentric capillaries in which pressurized gas permeates through an inner Teflon AF-2400 tube and reacts with dissolved substrate within a liquid phase that flows within a second gas impermeable tube. This Account examines our efforts toward the development of a simple, unified methodology for the processing of gaseous reagents in flow by way of development of a tube-in-tube reactor device and applications to key C-C, C-N, and C-O bond forming and hydrogenation reactions. We further describe the application to multistep reactions using solid-supported reagents and extend the technology to processes utilizing multiple gas reagents. A key feature of our work is the development of computer-aided imaging techniques to allow automated in-line monitoring of gas concentration and stoichiometry in real time. We anticipate that this Account will illustrate the convenience and benefits of membrane tube-in-tube reactor technology to improve and concomitantly broaden the scope of gas/liquid/solid reactions in organic synthesis.

  16. A comparative study on the lithium-ion storage performances of carbon nanotubes and tube-in-tube carbon nanotubes.

    PubMed

    Xu, Yi-Jun; Liu, Xi; Cui, Guanglei; Zhu, Bo; Weinberg, Gisela; Schlögl, Robert; Maier, Joachim; Su, Dang Sheng

    2010-03-22

    A comparative study of the electrochemical performances of carbon nanotubes and tube-in-tube carbon nanotubes reveals a dependence effect of lithium-ion storage behavior on the detailed nanostructure of carbon nanotubes. In particular, the impurity that graphitic particles or graphene fragments inherently present in carbon nanotubes plays a crucial role in the lithium-ion storage capacity of the carbon nanotubes. Compared to acid-washed carbon nanotubes, the assembly of graphitic impurity fragments in the tube-in-tube structures hinders lithium-ion diffusion, thus drastically decreasing the rate performance of lithium-ion storage. Significantly, our results indicate that the lithium-ion storage capacity of carbon nanotubes as anode electrodes can be improved or controlled by optimizing the microstructure composition of impurity graphitic nanoparticles or graphene fragments in the matrix of the carbon nanotubes.

  17. Automated library synthesis of cyclopropyl boronic esters employing diazomethane in a tube-in-tube flow reactor.

    PubMed

    Koolman, Hannes F; Kantor, Stanislaw; Bogdan, Andrew R; Wang, Ying; Pan, Jeffrey Y; Djuric, Stevan W

    2016-07-01

    The efficient synthesis of cyclopropyl boronic esters in library format using a diazomethane flow reactor has been achieved. A pivotal component of the system is a fully automated tube-in-tube reactor allowing for safe handling of hazardous diazomethane on repeated small scale and for the generation of larger quantities of product. The setup enables the repeated execution of Pd-catalyzed cyclopropanation reactions without compromising its operation over time. PMID:27314279

  18. Tube-in-tube reactor as a useful tool for homo- and heterogeneous olefin metathesis under continuous flow mode.

    PubMed

    Skowerski, Krzysztof; Czarnocki, Stefan J; Knapkiewicz, Paweł

    2014-02-01

    A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications.

  19. Role of individual lower limb joints in reactive stability control following a novel slip in gait.

    PubMed

    Yang, Feng; Pai, Yi-Chung

    2010-02-10

    Instability after slip onset is a key precursor leading to subsequent falls during gait. The purpose of this study was to determine the impact of reactive muscular response from individual lower limb joints on regaining stability control and impeding a novel and unannounced slip during the ensuing single-stance phase. Ten young adults' resultant moments at three lower limb joints of both limbs, initially derived by an inverse-dynamics approach from empirical data, were optimized to accurately reproduce the original motion before being applied as input to the control variables of their individualized forward-dynamics model. Systematic alteration of the moments of each joint caused corresponding changes in the displacement and velocity of the center of mass (COM) and base of support (BOS) (i.e. their state variables, x(COM), x (COM), x(BOS), x (BOS)), and in the COM stability. The model simulation revealed that these joints had little influence on x (COM) but had substantial impact on x (BOS) reduction, leading to improve the COM stability, mostly from knee flexors, followed by hip extensors, of the slipping limb. Per unit reactive increase in normalized knee flexor or hip extensor moments and per unit reactive reduction in commonly observed plantar-flexor moments could lead to as much as 57.72+/-10.46 or 22.33+/-5.55 and 13.09+/-2.27 units of reduction in normalized x (BOS), respectively. In contrast, such influence was negligible from the swing limb during this period, irrespective of individual variability.

  20. Tube-in-tube reactor as a useful tool for homo- and heterogeneous olefin metathesis under continuous flow mode.

    PubMed

    Skowerski, Krzysztof; Czarnocki, Stefan J; Knapkiewicz, Paweł

    2014-02-01

    A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications. PMID:24167003

  1. Catalytic Chan-Lam coupling using a 'tube-in-tube' reactor to deliver molecular oxygen as an oxidant.

    PubMed

    Mallia, Carl J; Burton, Paul M; Smith, Alexander M R; Walter, Gary C; Baxendale, Ian R

    2016-01-01

    A flow system to perform Chan-Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times. PMID:27559412

  2. Erythorbic acid promoted formation of CdS QDs in a tube-in-tube micro-channel reactor

    SciTech Connect

    Liang, Yan; Tan, Jiawei; Wang, Jiexin; Chen, Jianfeng; Sun, Baochang; Shao, Lei

    2014-12-15

    Erythorbic acid assistant synthesis of CdS quantum dots (QDs) was conducted by homogeneous mixing of two continuous liquids in a high-throughput microporous tube-in-tube micro-channel reactor (MTMCR) at room temperature. The effects of the micropore size of the MTMCR, liquid flow rate, mixing time and reactant concentration on the size and size distribution of CdS QDs were investigated. It was found that the size and size distribution of CdS QDs could be tuned in the MTMCR. A combination of erythorbic acid promoted formation technique with the MTMCR may be a promising pathway for controllable mass production of QDs.

  3. The effect of magnesium oxide supplementation to aluminum oxide slip on the jointing of aluminum oxide bars.

    PubMed

    Odatsu, Tetsurou; Sawase, Takashi; Kamada, Kohji; Taira, Yohsuke; Shiraishi, Takanobu; Atsuta, Mitsuru

    2008-03-01

    The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) to create a jointing material for In-Ceram Alumina. Jointed In-Ceram Alumina bars with In-Ceram Alumina slips containing 0-1.0 mass% MgO were examined by a three-point bending test. Joint-free bars were also tested as controls. Fracture surfaces were evaluated by scanning electron microscopy. In addition, linear shrinkage and fracture toughness were assessed. The 0.3 mass% MgO group showed the highest flexural strength among the jointed groups, and there were no statistical differences between the joint-free control groups. The fracture surface of 0.3 mass% MgO group showed increased sintering densification with reduced micropore size. No linear shrinkage was observed with the addition of MgO to the alumina slip. Added MgO was also effective in boosting fracture toughness. The present findings indicate that the MgO-supplemented binding material is useful for clinical applications.

  4. IN-SITU MONITORING OF PRODUCT STREAMS FROM A SPINNING TUBE-IN-TUBE REACTOR USING A METTLER-TOLEDO REACT-IR

    EPA Science Inventory

    A Mettler-Toledo ReactIR system has been used for in-line, real-time monitoring of the product stream from a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California). This combination of a process intensified continuous-flow reactor and an in-situ analytic...

  5. Flow synthesis using gaseous ammonia in a Teflon AF-2400 tube-in-tube reactor: Paal-Knorr pyrrole formation and gas concentration measurement by inline flow titration.

    PubMed

    Cranwell, Philippa B; O'Brien, Matthew; Browne, Duncan L; Koos, Peter; Polyzos, Anastasios; Peña-López, Miguel; Ley, Steven V

    2012-08-14

    Using a simple and accessible Teflon AF-2400 based tube-in-tube reactor, a series of pyrroles were synthesised in flow using the Paal-Knorr reaction of 1,4-diketones with gaseous ammonia. An inline flow titration technique allowed measurement of the ammonia concentration and its relationship to residence time and temperature.

  6. Fabrication of CNT@void@SnO2@C with tube-in-tube nanostructure as high-performance anode for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Tian, Qinghua; Tian, Yang; Zhang, Zhengxi; Yang, Li; Hirano, Shin-ichi

    2015-09-01

    Tin dioxide/carbon composites is an important class of promising candidates for anode materials with superior electrochemical performance and thus have attracted extensive attention. Herein, a tube-in-tube nanostructure, denoted as CNT@void@SnO2@C, has been fabricated by a facile and novel strategy. The possible formation mechanism is also discussed and determined by TEM, XRD and XPS characterizations. As a promising anode material for lithium-ion batteries, the CNT@void@SnO2@C exhibits superior lithium storage properties, delivering a reversible capacity of 702.5 mAh g-1 at 200 mA g-1 even after 350 cycles. The excellent performances should be benefited from the peculiar tube-in-tube nanostructure, in which SnO2 located between CNT and outermost carbon coating layers can sure the structural integrity and high conductivity during long-term cycling, and one-dimensional void space formed between the inner CNT and outer SnO2@C nanotubes, in particular, can provide larger free space for alleviating the huge volume variation of SnO2 and accommodating the stress formed during repeated discharge/charge process.

  7. Synthesis and characterization of a novel tube-in-tube nanostructured PPy/MnO{sub 2}/CNTs composite for supercapacitor

    SciTech Connect

    Li, Juan; Que, Tingli; Huang, Jianbin

    2013-02-15

    Graphical abstract: A novel tube-in-tube nanostructured PPy/MnO{sub 2}/CNTs composite have been successfully fabricated. Its inner tubules are CNTs and the outer tubules are template-synthesized PPy. Most MnO{sub 2} nanoparticles are sandwiched between the inner and outer wall, some relatively large particles are also latched onto the outside wall of the PPy tube. The composite yields a good electrochemical reversibility through 1000 cycles’ cyclic voltammogram (CV) test and galvanostatic charge–discharge experiments at different current densities. Display Omitted Highlights: ► We fabricate a ternary organic–inorganic complex of PPy/MnO{sub 2}/CNTs composite. ► We characterize its morphological structures and properties by several techniques. ► The composite possesses the typical tube-in-tube nanostructures. ► Most MnO{sub 2} nanoparticles are sandwiched between the inner CNTs and outer PPy wall. ► The composite has good electrochemical reversibility for supercapacitor. -- Abstract: Ternary organic–inorganic complex of polypyrrole/manganese dioxide/carbon nanotubes (PPy/MnO{sub 2}/CNTs) composite was prepared by in situ chemical oxidation polymerization of pyrrole in the host of inorganic matrix of MnO{sub 2} and CNTs, using complex of methyl orange (MO)/FeCl{sub 3} was used as a reactive self-degraded soft-template. The morphological structures of the composite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopic (HRTEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), respectively. All the results indicate that the PPy/MnO{sub 2}/CNTs composite possesses the typical tube-in-tube nanostructures: the inner tubules are CNTs and the outer tubules are template-synthesized PPy. MnO{sub 2} nanoparticles may either sandwich the space between the inner and outer tubules or directly latch onto the wall of the PPy tubes. The composite

  8. Influence of the bond-slip relationship on the flexural capacity of R.C. joints damaged by corrosion

    NASA Astrophysics Data System (ADS)

    Imperatore, Stefania

    2016-06-01

    In moderate and aggressive environmental condition, old reinforced concrete structures are often subjected to corrosive phenomena. Corrosion causes cracking, loss of diameter in reinforcement and variation of the bond behavior between steel and concrete. Then, in presence of cyclic actions like the seismic ones, old R.C. elements vary their ultimate drift, ductility, plastic rotation capacity and energy dissipation with the corrosion level. The problem is of current interest: the issue has been introduced in some paragraph of the Model Code 2010 and a committee is now drafting a new document on assessment strategies on existing concrete structures also damaged by corrosion. In this work, a first step on the analysis of the impact of the corrosion on the seismic behavior of R.C. elements is assessed: by mean FEM analyses, of a poor detailed column/foundation joint is analyzed in a parametric way in order to evaluate the influence of the bond-slip degradation by corrosion on the element flexural capacity.

  9. Slip distribution of the 2015 September 16, Illapel (Chile) Mw 8.3 earthquake from joint inversion of tsunami and InSAR data

    NASA Astrophysics Data System (ADS)

    Piatanesi, Alessio; Romano, Fabrizio; Lorito, Stefano; Tolomei, Cristiano; Atzori, Simone

    2016-04-01

    On September 16, 2015 an Mw 8.3 interplate earthquake occurred offshore the Illapel region, Chile, approximately in the area of the 1943 Mw 8.1 earthquake. The epicenter is located at 71.7 °W, 31.6 °S at a depth of ~25 km. In this region the Nazca Plate is subducting under the South America Plate with a convergence rate of ˜74mm/yr. This earthquake generated a tsunami that struck the Chilean coast from ~24 °S to ~38 °S, with particularly severe damages around the area of Coquimbo city where a tide gauge recorded a maximum tsunami wave amplitude of ~4.7 m. The tsunami has been distinctly recorded by several tide gauges distributed along the Chilean coast and also by some DART buoys located in the South Pacific ocean. The inland coseismic deformation has been detected through InSAR processing of Sentinel-1 images, acquired from ascending and descending orbits. In this work we present the slip distribution of the earthquake obtained by jointly inverting the tsunami waveforms recorded by 3 DART buoys and 15 tide gauges, and the ground displacement retrieved by InSAR data. In order to honour the geometry of the subducting plate, we use a fault model that accounts for the variability of the strike and dip angles along the slipping surface composed by 20x20 km subfaults. We use the Green's function approach and a simulated annealing technique to solve the inverse problem. Synthetic checkerboard tests indicate that tsunami and InSAR data well constrain the offshore and onshore part of the slip distribution respectively, whereas the overall target slip distribution is well recovered by jointly using the two datasets. The slip distribution of the Illapel event features a main patch of slip updip of the hypocenter, extending for ~200 km along strike, ~120 km along dip and reaching the trench with a maximum slip of ~9 m; the slip direction is ~110°, pretty consistent with the relative convergence axis between the Nazca and the South America Plates. We also observe a

  10. Experimental investigation of the dynamic installation of a slip joint connection between the monopile and tower of an offshore wind turbine

    NASA Astrophysics Data System (ADS)

    Segeren, M. L. A.; Hermans, K. W.

    2014-06-01

    The failure of the traditional grouted connections of offshore wind turbines has led to the investigation of alternatives that provide a connection between the foundation pile and the turbine tower. An alternative to the traditional joint is a steel-to-steel connection also called a slip joint. To ensure a proper fit of the slip joint a dynamic installation of the joint is proposed. In this contribution, the effectiveness of harmonic excitation as an installation procedure is experimentally investigated using a 1:10 scaled model of the joint. During the dynamic installation test the applied static load, settlements and dynamic response of the joint are monitored using respectively load cells, taut wires and strain gauges placed both inside and outside the conical surfaces. The results show that settlement occurs only when applying a harmonic load at specific forcing frequencies. The settlement stabilizes to a certain level for each of the specific frequencies, indicating that a controlled way of installation is possible. The results show that it is essential to vibrate at specific frequencies and that a larger amplitude of the harmonic force does not automatically lead to additional settlement.

  11. Coseismic slip distribution of the 2015 Mw7.8 Gorkha, Nepal, earthquake from joint inversion of GPS and InSAR data for slip within a 3-D heterogeneous Domain

    NASA Astrophysics Data System (ADS)

    Tung, Sui; Masterlark, Timothy

    2016-05-01

    We derive a coseismic slip model of the 2015 Mw7.8 Gorkha earthquake on the basis of GPS and line-of-sight displacements from ALOS-2 descending interferograms, using Green's functions calculated with a 3-D finite element model (FEM). The FEM simulates a nonuniform distribution of elastic material properties and a precise geometric configuration of the irregular topographical surface. The rupturing fault is modeled as a low-angle and north dipping surface within the Main Frontal Thrust along the convergent margin of the Himalayas. The optimal model that inherits heterogeneous material properties provides a significantly better solution than that in a homogenous domain at the 95% confidence interval. The best fit solution for the domain having a nonuniform distribution of material properties reveals a rhombus-shaped slip zone of three composite asperities. Slip is primarily concentrated at a depth of 15 km with both dip-slip (maximum 6.54 m) and strike-slip (maximum 2.0 m) components, giving rise to a geodetic-based moment of 1.09 × 1021 Nm in general agreement with the seismological estimate. The optimal relative weights among GPS and interferometric synthetic aperture radar (InSAR) are deduced from a new method, MC-HVCE which combines a Monte Carlo search and a Helmert Method of Variance Components Estimation. This method determines the relative weights in a systemic approach which preserves the intrinsic solution smoothness. The joint solution is significantly better than those inverted from each individual data set. This methodology allows us to integrate multiple data sets of geodetic observations with seismic tomography, in an effort to achieve a better understanding of seismic ruptures within crustal heterogeneity.

  12. Spatiotemporal model of aseismic slip on the Hayward fault inferred from joint inversion of geodetic and seismic data time series

    NASA Astrophysics Data System (ADS)

    Shirzaei, M.; Burgmann, R.

    2011-12-01

    Interferometric synthetic aperture radar (InSAR) provides valuable spatiotemporal observations of surface deformation in volcanic and tectonic areas. In this study we generate a long time series of InSAR-measured deformation over the San Francisco Bay Area by combining over 100 ERS1/2 and Envisat SAR acquisitions from 1992 through 2011. We apply an advanced multitemporal processing algorithm that uses multiple-master interferometry and generate about 700 interferograms (ERS-ERS, Envisat-Envisat and ERS-Envisat pairs) with temporal and perpendicular baseline smaller than 4 years and 300 m, respectively. The systematic errors (such as DEM error and atmospheric delay) are estimated and reduced by using a variety of wavelet based filters. The differential displacement measured in each unwrapped interferogram is inverted by using an L1-norm minimization approach to generate time series of the surface displacement for identified stable pixels. Using a Kalman filter, the line-of-sight velocity is estimated, temporal random noise is reduced and the displacement variance-covariance matrix is refined. To solve for the time dependent model of aseismic slip on the Hayward fault, the upper-crustal fault plane is discretized into triangular patches. The size of these patches is optimized in a way that allows estimating the fault slip with maximum precision. Then, we apply an iterated inversion approach, combining static slip inversion and Kalman filtering to model temporal behavior of the slip. For the static inversion we expand the slip to the wavelet base functions and truncate noisy coefficients, which provide a solution equivalent to implementation of the Laplace smoothing operator in conventional slip inversion. This novel approach, however, overcomes the need of choosing a smoothing operator and allows automating the whole inversion step. Since we aim to integrate seismic and creepmeter data sets, the issue of relative weighting of these data sets becomes important, which

  13. Implementing a C++ Version of the Joint Seismic-Geodetic Algorithm for Finite-Fault Detection and Slip Inversion for Earthquake Early Warning

    NASA Astrophysics Data System (ADS)

    Smith, D. E.; Felizardo, C.; Minson, S. E.; Boese, M.; Langbein, J. O.; Guillemot, C.; Murray, J. R.

    2015-12-01

    The earthquake early warning (EEW) systems in California and elsewhere can greatly benefit from algorithms that generate estimates of finite-fault parameters. These estimates could significantly improve real-time shaking calculations and yield important information for immediate disaster response. Minson et al. (2015) determined that combining FinDer's seismic-based algorithm (Böse et al., 2012) with BEFORES' geodetic-based algorithm (Minson et al., 2014) yields a more robust and informative joint solution than using either algorithm alone. FinDer examines the distribution of peak ground accelerations from seismic stations and determines the best finite-fault extent and strike from template matching. BEFORES employs a Bayesian framework to search for the best slip inversion over all possible fault geometries in terms of strike and dip. Using FinDer and BEFORES together generates estimates of finite-fault extent, strike, dip, preferred slip, and magnitude. To yield the quickest, most flexible, and open-source version of the joint algorithm, we translated BEFORES and FinDer from Matlab into C++. We are now developing a C++ Application Protocol Interface for these two algorithms to be connected to the seismic and geodetic data flowing from the EEW system. The interface that is being developed will also enable communication between the two algorithms to generate the joint solution of finite-fault parameters. Once this interface is developed and implemented, the next step will be to run test seismic and geodetic data through the system via the Earthworm module, Tank Player. This will allow us to examine algorithm performance on simulated data and past real events.

  14. Seismic and Aseismic Slip on the San-Jacinto Fault Near Anza, CA, from Joint Analysis of Strain and Aftershock Data

    NASA Astrophysics Data System (ADS)

    Inbal, A.; Avouac, J. P.; Ampuero, J. P.

    2014-12-01

    The San-Jacinto Fault (SJF) is the most active fault in southern California, which together with the southern San-Andreas Fault accommodates a large fraction of the motion across the plate boundary. Seismicity along the SJF is distributed over several fault segments with distinct spatio-temporal characteristics. One of these segments, known as the Anza seismic gap, is a 25 km long strand almost devoid of seismicity. In recent years, four M4-5 events occurred SE of the gap. Despite their moderate magnitudes, these earthquakes triggered rich aftershock sequences and pronounced afterslip that lasted for several weeks, and was well captured by nearby PBO borehole strain meters. A similar transient was remotely triggered by the 2010 El Mayor-Cucapah earthquake. Geodetic and seismic observations following a local M5.4 mainshock indicate that afterslip propagated unilaterally towards the NW at speed of about 5 km/day. We infer the distribution of slip via a joint inversion of the aftershock and strain data. Our approach is based on Dieterich's (1994) model relating the evolution of seismicity rate to applied stresses, within the framework of rate-and-state friction. This approach provides resolution power at depths inaccessible to the surface geodetic network. Moreover, it allows us to gain important insights onto the fault mechanical properties. We apply this inversion scheme to episodes that occurred during 2010. Remarkably, we find that the cumulative moment released post-seismically during the locally triggered transient is 5-10 times larger than the moment of the mainshock. We show that the data favour a model in which deep slip transients, which may develop due to local or remote earthquakes, occur on a weak, close-to-velocity-neutral fault. The transients increase the stress along the Anza gap, and trigger earthquakes outside it through static stress transfer.

  15. Slip Kits.

    ERIC Educational Resources Information Center

    Coombes, S. D.

    1979-01-01

    Discusses the process of developing the Science Lessons from Industrial Processes (SLIP) kits by 16 British science teachers. The content, applicability, and components of these kits (based upon local industries) are also included. (HM)

  16. A tube-in-tube thermophotovoltaic generator

    SciTech Connect

    Ashcroft, J.; Campbell, B.; Depoy, D.

    1996-12-31

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  17. Tube-in-tube thermophotovoltaic generator

    DOEpatents

    Ashcroft, John; Campbell, Brian; DePoy, David

    1998-01-01

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell.

  18. Tube-in-tube thermophotovoltaic generator

    DOEpatents

    Ashcroft, J.; Campbell, B.; DePoy, D.

    1998-06-30

    A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell. 8 figs.

  19. Kinematic Slip Model for 12 May 2008 Wenchuan-Beichuan Mw 7.9 Earthquake from Joint Inversion of ALOS, Envisat, and Teleseismic Data

    NASA Technical Reports Server (NTRS)

    Fielding, Eric; Sladen, Anthony; Avouac, Jean-Philippe; Li, Zhenhong; Ryder, Isabelle; Burgmann, Roland

    2008-01-01

    The presentations explores kinematics of the Wenchaun-Beichuan earthquake using data from ALOS, Envisat, and teleseismic recordings. Topics include geomorphic mapping, ALOS PALSAR range offsets, ALOS PALSAR interferometry, Envisat IM interferometry, Envisat ScanSAR, Joint GPS-InSAR inversion, and joint GPS-teleseismic inversion (static and kinematic).

  20. Electro-optical hybrid slip ring

    NASA Astrophysics Data System (ADS)

    Hong, En

    2005-11-01

    The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

  1. Lower extremity corrective reactions to slip events.

    PubMed

    Cham, R; Redfern, M S

    2001-11-01

    A significant number of injuries in the workplace is attributed to slips and falls. Biomechanical responses to actual slip events determine whether the outcome of a slip will be recovery or a fall. The goal of this study was to examine lower extremity joint moments and postural adjustments for experimental evidence of corrective strategies evoked during slipping in an attempt to prevent falling. Sixteen subjects walked onto a possibly oily vinyl tile floor, while ground reaction forces and body motion were recorded at 350 Hz. The onset of corrective reactions by the body in an attempt to recover from slips became evident at about 25% of stance and continued until about 45% into stance, i.e. on average between 190 and 350 ms after heel contact. These reactions included increased flexion moment at the knee and extensor activity at the hip. The ankle, on the other hand, acted as a passive joint (no net moment) during fall trials. Joint kinematics showed increased knee flexion and forward rotation of the shank in an attempt to bring the foot back towards the body. Once again, the ankle kinematics appeared to play a less dominant role (compared to the knee) in recovery attempts. This study indicates that humans generate corrective reactions to slips that are different than previously reported responses to standing perturbations translating the supporting surface. PMID:11672718

  2. Reconsidering Fault Slip Scaling

    NASA Astrophysics Data System (ADS)

    Gomberg, J. S.; Wech, A.; Creager, K. C.; Obara, K.; Agnew, D. C.

    2015-12-01

    The scaling of fault slip events given by the relationship between the scalar moment M0, and duration T, potentially provides key constraints on the underlying physics controlling slip. Many studies have suggested that measurements of M0 and T are related as M0=KfT3 for 'fast' slip events (earthquakes) and M0=KsT for 'slow' slip events, in which Kf and Ks are proportionality constants, although some studies have inferred intermediate relations. Here 'slow' and 'fast' refer to slip front propagation velocities, either so slow that seismic radiation is too small or long period to be measurable or fast enough that dynamic processes may be important for the slip process and measurable seismic waves radiate. Numerous models have been proposed to explain the differing M0-T scaling relations. We show that a single, simple dislocation model of slip events within a bounded slip zone may explain nearly all M0-T observations. Rather than different scaling for fast and slow populations, we suggest that within each population the scaling changes from M0 proportional to T3 to T when the slipping area reaches the slip zone boundaries and transitions from unbounded, 2-dimensional to bounded, 1-dimensional growth. This transition has not been apparent previously for slow events because data have sampled only the bounded regime and may be obscured for earthquakes when observations from multiple tectonic regions are combined. We have attempted to sample the expected transition between bounded and unbounded regimes for the slow slip population, measuring tremor cluster parameters from catalogs for Japan and Cascadia and using them as proxies for small slow slip event characteristics. For fast events we employed published earthquake slip models. Observations corroborate our hypothesis, but highlight observational difficulties. We find that M0-T observations for both slow and fast slip events, spanning 12 orders of magnitude in M0, are consistent with a single model based on dislocation

  3. Contactless Magnetic Slip Ring

    NASA Technical Reports Server (NTRS)

    Kumagai, Hiroyuki (Inventor); Deardon, Joe D. (Inventor)

    1997-01-01

    A contactless magnetic slip ring is disclosed having a primary coil and a secondary coil. The primary and secondary coils are preferably magnetically coupled together, in a highly reliable efficient manner, by a magnetic layered core. One of the secondary and primary coils is rotatable and the contactless magnetic slip ring provides a substantially constant output.

  4. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Shafting joints. 27.935 Section 27.935... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must...

  5. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Shafting joints. 29.935 Section 29.935... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation...

  6. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shafting joints. 27.935 Section 27.935... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must...

  7. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Shafting joints. 27.935 Section 27.935... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must...

  8. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shafting joints. 29.935 Section 29.935... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation...

  9. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Shafting joints. 27.935 Section 27.935... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must...

  10. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Shafting joints. 29.935 Section 29.935... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation...

  11. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Shafting joints. 29.935 Section 29.935... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation...

  12. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Shafting joints. 29.935 Section 29.935... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation...

  13. SLIP CASTING METHOD

    DOEpatents

    Allison, A.G.

    1959-09-01

    S>A process is described for preparing a magnesium oxide slip casting slurry which when used in conjunction with standard casting techniques results in a very strong "green" slip casting and a fired piece of very close dimensional tolerance. The process involves aging an aqueous magnestum oxide slurry, having a basic pH value, until it attains a specified critical viscosity at which time a deflocculating agent is added without upsetting the basic pH value.

  14. Coseismic Slip Model of the M 7.8 2015 Nepal Earthquake and its M 7.2 Aftershock from Joint Inversion of InSAR and GPS Data

    NASA Astrophysics Data System (ADS)

    Cheloni, D.; Tolomei, C.; Bignami, C.; D'Agostino, N.; Atzori, S.

    2015-12-01

    We derived a coseismic slip model for the M 7.8 2015 Nepal earthquake on the basis of radar line-of-sight displacements retrieved from RADARSAT, ALOS and SENTINEL interferograms and GPS data. We use the surface trace of the Main Himalayan Thrust (MHT) and moment tensor solution to approximate the earthquake rupture plane with a planar thrust fault having a strike of ~295° and a dip of ~10°. Our rupture model suggests that the slip area is about 120 x 50 km, with the most of the moment release limited to a depth between 10-20 km. Therefore the earthquake did not reach the surface suggesting a marked shallow slip deficit in the slip depth distribution. The earthquake released a seismic moment of 7.88E+20 Nm, corresponding to a Mw 7.88. Adopting the same fault geometry we also estimated the slip distribution related to the M 7.2 aftershock that occurred near the eastern end of the main coseismic asperity. The aftershock rupture model shows a more compact slip area of about 30 x 30 km, releasing a moment of 5.49E+19 Nm and corresponding to a Mw 7.13. We calculated the static stress changes on the assumed fault plane due to the mainshock. The result suggests loading of the fault around the main coseismic patch where indeed most of the aftershocks, comprising the M 7.2 event, were primarily distributed. Future researches will be focused on the up-dip locked portions of the MHT that did not break during the 25 April 2015 Nepal earthquake and the monitoring of the post-seismic phase by means of InSAR and GPS data.

  15. Inorganic glass ceramic slip rings

    NASA Technical Reports Server (NTRS)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  16. Quantum phase slip noise

    NASA Astrophysics Data System (ADS)

    Semenov, Andrew G.; Zaikin, Andrei D.

    2016-07-01

    Quantum phase slips (QPSs) generate voltage fluctuations in superconducting nanowires. Employing the Keldysh technique and making use of the phase-charge duality arguments, we develop a theory of QPS-induced voltage noise in such nanowires. We demonstrate that quantum tunneling of the magnetic flux quanta across the wire yields quantum shot noise which obeys Poisson statistics and is characterized by a power-law dependence of its spectrum SΩ on the external bias. In long wires, SΩ decreases with increasing frequency Ω and vanishes beyond a threshold value of Ω at T →0 . The quantum coherent nature of QPS noise yields nonmonotonous dependence of SΩ on T at small Ω .

  17. Universal behavior in ideal slip

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Ferrante, John; Smith, John R.

    1991-01-01

    The slip energies and stresses are computed for defect-free crystals of Ni, Cu, Ag, and Al using the many-atom approach. A simple analytical expression for the slip energies is obtained, leading to a universal form for slip, with the energy scaled by the surface energy and displacement scaled by the lattice constant. Maximum stresses are found to be somewhat larger than but comparable with experimentally determined maximum whisker strengths.

  18. Refining the shallow slip deficit

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohua; Tong, Xiaopeng; Sandwell, David T.; Milliner, Christopher W. D.; Dolan, James F.; Hollingsworth, James; Leprince, Sebastien; Ayoub, Francois

    2016-03-01

    Geodetic slip inversions for three major (Mw > 7) strike-slip earthquakes (1992 Landers, 1999 Hector Mine and 2010 El Mayor-Cucapah) show a 15-60 per cent reduction in slip near the surface (depth < 2 km) relative to the slip at deeper depths (4-6 km). This significant difference between surface coseismic slip and slip at depth has been termed the shallow slip deficit (SSD). The large magnitude of this deficit has been an enigma since it cannot be explained by shallow creep during the interseismic period or by triggered slip from nearby earthquakes. One potential explanation for the SSD is that the previous geodetic inversions lack data coverage close to surface rupture such that the shallow portions of the slip models are poorly resolved and generally underestimated. In this study, we improve the static coseismic slip inversion for these three earthquakes, especially at shallow depths, by: (1) including data capturing the near-fault deformation from optical imagery and SAR azimuth offsets; (2) refining the interferometric synthetic aperture radar processing with non-boxcar phase filtering, model-dependent range corrections, more complete phase unwrapping by SNAPHU (Statistical Non-linear Approach for Phase Unwrapping) assuming a maximum discontinuity and an on-fault correlation mask; (3) using more detailed, geologically constrained fault geometries and (4) incorporating additional campaign global positioning system (GPS) data. The refined slip models result in much smaller SSDs of 3-19 per cent. We suspect that the remaining minor SSD for these earthquakes likely reflects a combination of our elastic model's inability to fully account for near-surface deformation, which will render our estimates of shallow slip minima, and potentially small amounts of interseismic fault creep or triggered slip, which could `make up' a small percentages of the coseismic SSD during the interseismic period. Our results indicate that it is imperative that slip inversions include

  19. Slip flow in graphene nanochannels

    NASA Astrophysics Data System (ADS)

    Kannam, Sridhar Kumar; Todd, B. D.; Hansen, J. S.; Daivis, Peter J.

    2011-10-01

    We investigate the hydrodynamic boundary condition for simple nanofluidic systems such as argon and methane flowing in graphene nanochannels using equilibrium molecular dynamics simulations (EMD) in conjunction with our recently proposed method [J. S. Hansen, B. D. Todd, and P. J. Daivis, Phys. Rev. E 84, 016313 (2011), 10.1103/PhysRevE.84.016313]. We first calculate the fluid-graphene interfacial friction coefficient, from which we can predict the slip length and the average velocity of the first fluid layer close to the wall (referred to as the slip velocity). Using direct nonequilibrium molecular dynamics simulations (NEMD) we then calculate the slip length and slip velocity from the streaming velocity profiles in Poiseuille and Couette flows. The slip lengths and slip velocities from the NEMD simulations are found to be in excellent agreement with our EMD predictions. Our EMD method therefore enables one to directly calculate this intrinsic friction coefficient between fluid and solid and the slip length for a given fluid and solid, which is otherwise tedious to calculate using direct NEMD simulations at low pressure gradients or shear rates. The advantages of the EMD method over the NEMD method to calculate the slip lengths/flow rates for nanofluidic systems are discussed, and we finally examine the dynamic behaviour of slip due to an externally applied field and shear rate.

  20. Small sized slip-ring capsule endurance testing

    NASA Astrophysics Data System (ADS)

    Mondier, Jean-Bernard

    2005-07-01

    Slip-ring capsules are mechanical units used to carry electrical signals or power currents through a rotating joint. They are used either in solar array drive mechanisms (SADM) or in scientific instruments like radiometers. Analyses of the latest missions show that the slip-rings requirements are more and more demanding. For example, the number of in-orbit mechanical cycles keeps increasing. As a result, a signal slip-ring technology, which had been successfully tested for a given need, now has to improve its performances. It was therefore interesting to try to reach the slip-rings technical limits by testing them beyond the required performance of already known space missions. Slip-rings units are currently used in mechanisms such as SADM for the CNES Proteus and Myriade satellite family. They can be also found in the payload instruments of the Megha-Tropiques satellite project, namely Madras and Scarab. A selected hardware was tested at the mechanism endurance laboratory of the CNES, in Toulouse. The typical in-orbit rotation speed was increased in order to limit the test duration to 2 years. The main interest of this work was to provide a continuous slip-ring performance status and a large set of engineering data. The main test results are presented and discussed. The following lines also report a part of the hardware detailed inspection and the lessons learned.

  1. Low-Friction Joint for Robot Fingers

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F.

    1985-01-01

    Mechanical linkage allows adjacent parts to move relative to each other with low friction and with no chatter, slipping, or backlash. Low-friction joint of two surfaces in rolling contact, held in alinement by taut flexible bands. No sliding friction or "stick-slip" motion: Only rolling-contact and bending friction within bands. Proposed linkage intended for finger joints in mechanical hands for robots and manipulators.

  2. A Reduced Order, One Dimensional Model of Joint Response

    SciTech Connect

    DOHNER,JEFFREY L.

    2000-11-06

    As a joint is loaded, the tangent stiffness of the joint reduces due to slip at interfaces. This stiffness reduction continues until the direction of the applied load is reversed or the total interface slips. Total interface slippage in joints is called macro-slip. For joints not undergoing macro-slip, when load reversal occurs the tangent stiffness immediately rebounds to its maximum value. This occurs due to stiction effects at the interface. Thus, for periodic loads, a softening and rebound hardening cycle is produced which defines a hysteretic, energy absorbing trajectory. For many jointed sub-structures, this hysteretic trajectory can be approximated using simple polynomial representations. This allows for complex joint substructures to be represented using simple non-linear models. In this paper a simple one dimensional model is discussed.

  3. Characterizing the Relationship of Tremor and Slip during Recent ETS Events in Northern Cascadia using Strainmeters, GPS, and Tremor Observations

    NASA Astrophysics Data System (ADS)

    Krogstad, R. D.; Schmidt, D. A.

    2014-12-01

    We investigate the relationship between slip and tremor during multiple recent slow slip events in northern Cascadia. While the relationship of geodetically detectable slow slip and nonvolcanic tremor appears to be broadly coincident, the exact spatial and temporal characteristics remain unclear at a finer scale. Typical GPS derived slip distributions tend to be spatially and temporally smoothed and offset slightly updip of tremor distributions. These discrepancies may be real, or they may be a consequence of the resolution of GPS data or an artifact of the inversion methodology. Borehole strainmeters provide additional independent geodetic constraints for characterizing slip, provide greater temporal resolution, and greater precision than GPS. However, various non-tectonic artifacts and other sources of error have limited the number of usable stations and made deriving reliable information from strainmeters during slip events difficult. We utilize strainmeters with low levels of noise and minimal observable artifacts to constrain forward models and to provide additional independent observations in joint geodetic inversions with GPS data. A series of slip distributions are derived by inverting strainmeter and GPS data using the Kalman-filter-based Extended Network Inversion Filter. To compare the tremor distributions to the geodetically derived slip we also construct slip distributions using tremor occurrences as a proxy for localized slip on the plate interface. The magnitude of slip per tremor occurrence is then scaled to best match the observed surface displacements. Separate slip distributions informed by GPS and tremor are then used to predict strain time series. The comparisons between strain predictions and observations produce mixed results. This may indicate that that tremor and slip are not always coincident. This is particularly evident during the Aug. 2010 event, where the peak GPS-derived slip is located in a region with decreased tremor activity

  4. Blood Flow, Slip, and Viscometry

    PubMed Central

    Nubar, Yves

    1971-01-01

    The viscosity of blood, measured by the usual viscometers in which slip is not considered, is found to be flow dependent, varying markedly with shear rate, pressure gradient, and vessel diameter in the lower ranges of these factors. The study postulates, on grounds thought reasonable, that slip may be present in blood flow, as a function of the nature of the wall surfaces, shear stress at the wall, and relative cell volume (RCV) adjacent to the wall. It presumes that blood possesses a specific, flow-independent viscosity, and determines theoretically the viscosity indications of viscometers if blood slipped in the instruments. The study shows that if the slip function is of a certain plausible form, these viscosity indications would exhibit a flow dependence of much the same pattern as the actual indications supplied by the usual viscometers. The slip postulate permits, therefore, an interpretation of the “anomalous” flow behavior of blood, dispensing with the prevailing assumption of an ad hoc variability of its viscosity with flow factors. To the extent that viscometric data for blood may be representative of other non-newtonian fluids, the slip postulate may be applicable to these fluids. PMID:5573368

  5. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  6. Whillans Ice Plain Stick Slip

    NASA Astrophysics Data System (ADS)

    Lipovsky, B.; Dunham, E. M.

    2015-12-01

    Concern about future sea level rise motivates the study of fast flowing ice. The Whillans Ice Plain (WIP) region of the West Antarctic Ice Sheet is notable for decelerating from previously fast motion during the instrumental record. Since most ice flux in Antarctica occurs through ice streams, understanding the conditions that cause ice stream stagnation is of basic importance in understanding the continent's contribution to future sea level rise. Although recent progress has been made in understanding the relationship between basal conditions and ice stream motion, direct observation of the temporal variation in subglacial conditions during ice stream stagnation has remained elusive. The Whillans Ice Plain flows to the sea mostly by way of stick-slip motion. We present numerical simulations of this stick-slip motion that capture the inertial dynamics, seismic waves, and the evolution of sliding with rate- and state-dependent basal friction. Large scale stick-slip behavior is tidally modulated and encompasses the entire WIP. Sliding initiates within one of several locked regions and then propagates outward with low average rupture velocity (~ 200 m/s). Sliding accelerates over a period of 200 s attain values as large as 65 m/d. From Newton's second law, this acceleration is ~ T / (rho H) for average shear stress drop T, ice thickness H, and ice density rho. This implies a 3 Pa stress drop that must be reconciled with the final stress drop of 300 Pa inferred from the total slip and fault dimensions. A possible explanation of this apparent discrepancy is that deceleration of the ice is associated with a substantial decrease in traction within rate-strengthening regions of the bed. During these large-scale sliding events, m-scale patches at the bed produce rapid (20 Hz) stick-slip motion. Each small event occurs over ~ 1/100 s, produces ~ 40 microns of slip, and gives rise to a spectacular form of seismic tremor. Variation between successive tremor episodes allows us

  7. Slow-Slip Propagation Speeds

    NASA Astrophysics Data System (ADS)

    Rubin, A. M.; Ampuero, J.

    2007-12-01

    Combined seismic and geodetic data from subduction zones and the Salton Trough have revealed slow slip events with reasonably well-defined propagation speeds. This in turn is suggestive of a more-or-less well- defined front separating nearly locked regions outside the slipping zone from interior regions that slide much more rapidly. Such crack-like nucleation fronts arise naturally in models of rate-and-state friction for lab-like values of a/b, where a and b are the coefficients of the velocity- and state-dependence of the frictional strength (with the surface being velocity-neutral for a/b=1). If the propagating front has a quasi-steady shape, the propagation and slip speeds are kinematically tied via the local slip gradient. Given a sufficiently sharp front, the slip gradient is given dimensionally by Δτp- r/μ', where Δτp-r is the peak-to-residual stress drop at the front and μ' the effective elastic shear modulus. Rate-and-state simulations indicate that Δτp-r is given reasonably accurately by bσ\\ln(Vmaxθi/Dc), where σ is the effective normal stress, Vmax is the maximum slip speed behind the propagating front, θi is the the value of "state" ahead of the propagating front, and Dc is the characteristic slip distance for state evolution. Except for a coefficient of order unity, Δτp-r is independent of the evolution law. This leads to Vprop/Vmax ~μ'/[bσ\\ln(Vmaxθi/Dc)]. For slip speeds a few orders of magnitude above background, \\ln(Vmaxθi/Dc) can with reasonable accuracy be assigned some representative value (~4-5, for example). Subduction zone transients propagate on the order of 10 km/day or 10-1 m/s. Geodetic data constrain the average slip speed to be a few times smaller than 1 cm/day or 10-7 m/s. However, numerical models indicate that the maximum slip speed at the front may be several times larger than the average, over a length scale that is probably too small to resolve geodetically, so a representative value of Vprop/Vmax may be ~106

  8. The evolution of faults formed by shearing across joint zones in sandstone

    NASA Astrophysics Data System (ADS)

    Myers, Rodrick; Aydin, Atilla

    2004-05-01

    The evolution of strike-slip and normal faults formed by slip along joint zones is documented by detailed field studies in the Jurassic Aztec Sandstone in the Valley of Fire State Park, Nevada, USA. Zones of closely spaced planar sub-parallel joints arranged en échelon are sheared, forming faults. Fracturing occurs as a result of shearing, forming new joints. Later shearing along these joints leads to successively formed small faults and newer joints. This process is repeated through many generations of fracturing with increasing fault slip producing a hierarchical array of structures. Strain localization produced by shearing of joint zones at irregularities in joint traces, fracture intersections, and in the span between adjacent sheared joints results in progressive fragmentation of the weakened sandstone, which leads to the formation of gouge along the fault zone. The length and continuity of the gouge and associated slip surfaces is related to the slip magnitude and fault geometry with slip ranging from several millimeters to about 150 m. Distributed damage in a zone surrounding the gouge core is related to the original joint zone configuration (step sense, individual sheared joint overlaps and separation), shear sense, and slip magnitude. Our evolutionary model of fault development helps to explain some outstanding issues concerning complexities in faulting such as, the variability in development of fault rock and fault related fractures, and the failure processes in faults.

  9. An analysis of a joint shear model for jointed media with orthogonal joint sets; Yucca Mountain Site Characterization Project

    SciTech Connect

    Koteras, J.R.

    1991-10-01

    This report describes a joint shear model used in conjunction with a computational model for jointed media with orthogonal joint sets. The joint shear model allows nonlinear behavior for both joint sets. Because nonlinear behavior is allowed for both joint sets, a great many cases must be considered to fully describe the joint shear behavior of the jointed medium. An extensive set of equations is required to describe the joint shear stress and slip displacements that can occur for all the various cases. This report examines possible methods for simplifying this set of equations so that the model can be implemented efficiently form a computational standpoint. The shear model must be examined carefully to obtain a computationally efficient implementation that does not lead to numerical problems. The application to fractures in rock is discussed. 5 refs., 4 figs.

  10. Study of fault slip modes

    NASA Astrophysics Data System (ADS)

    Adushkin, V. V.; Kocharyan, G. G.; Novikov, V. A.

    2016-09-01

    We present the data of the laboratory experiments on studying the regularities of gradual transition from the stick-slip behavior to aseismic creeping on the interblock boundary. The experiments show that small variations in the material composition in the principal slip zones of the faults may cause a significant change in the fraction of seismic energy radiated during the dynamic unloading of the adjacent segment of the rock mass. The experiments simulate interblock sliding regimes with the values of the scaled kinetic energy differing by a few orders of magnitude and relatively small distinctions in the strength of the contacts and in the amplitude of the released shear stresses. The results of the experiments show that the slip mode and the fraction of the deformation energy that goes into the seismic radiation are determined by the ratio of two parameters—the stiffness of the fault and the stiffness of the enclosing rock mass. An important implication of the study for solving the engineering tasks is that for bringing a stressed segment of a fault or a crack into a slip mode with low-intensity radiation of seismic energy, the anthropogenic impact should be aimed at diminishing the stiffness of the fault zone rather than at releasing the excessive stresses.

  11. Hydrodynamic slip in silicon nanochannels

    NASA Astrophysics Data System (ADS)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-03-01

    Equilibrium and nonequilibrium molecular dynamics simulations were performed to better understand the hydrodynamic behavior of water flowing through silicon nanochannels. The water-silicon interaction potential was calibrated by means of size-independent molecular dynamics simulations of silicon wettability. The wettability of silicon was found to be dependent on the strength of the water-silicon interaction and the structure of the underlying surface. As a result, the anisotropy was found to be an important factor in the wettability of these types of crystalline solids. Using this premise as a fundamental starting point, the hydrodynamic slip in nanoconfined water was characterized using both equilibrium and nonequilibrium calculations of the slip length under low shear rate operating conditions. As was the case for the wettability analysis, the hydrodynamic slip was found to be dependent on the wetted solid surface atomic structure. Additionally, the interfacial water liquid structure was the most significant parameter to describe the hydrodynamic boundary condition. The calibration of the water-silicon interaction potential performed by matching the experimental contact angle of silicon led to the verification of the no-slip condition, experimentally reported for silicon nanochannels at low shear rates.

  12. Wall slip in polymer melts

    NASA Astrophysics Data System (ADS)

    Léger, L.; Hervet, H.; Massey, G.; Durliat, E.

    1997-09-01

    We present a review of the recent characterizations of the flow behaviour of high-molecular-weight polymer melts, with special emphasis on situations in which slip at the wall appears. These characterizations are based on direct measurements of the local velocity of the fluid, in the immediate vicinity of the solid wall, through near-field velocimetry techniques. The results demonstrate the importance of polymer molecules anchored on the solid surface, either by strong adsorption or by chemical grafting, and entangled with the bulk polymer, to produce a strong friction at low shear rates and to lead to a shear rate threshold above which strong slip at the wall and low friction develop. The evolution of the shear rate threshold and of the flow characteristics (the length of the extrapolation of the velocity profile to zero, the critical slip velocity for the onset of strong slip, ...) with the molecular parameters of the system (the molecular weights of the bulk and surface chains, and the surface density of anchored chains) is analysed and compared with the predictions of recent theoretical models.

  13. Slip rate and tremor genesis in Cascadia

    USGS Publications Warehouse

    Wech, Aaron G.; Bartlow, Noel M.

    2014-01-01

    At many plate boundaries, conditions in the transition zone between seismogenic and stable slip produce slow earthquakes. In the Cascadia subduction zone, these events are consistently observed as slow, aseismic slip on the plate interface accompanied by persistent tectonic tremor. However, not all slow slip at other plate boundaries coincides spatially and temporally with tremor, leaving the physics of tremor genesis poorly understood. Here we analyze seismic, geodetic, and strainmeter data in Cascadia to observe for the first time a large, tremor-generating slow earthquake change from tremor-genic to silent and back again. The tremor falls silent at reduced slip speeds when the migrating slip front pauses as it loads the stronger adjacent fault segment to failure. The finding suggests that rheology and slip-speed-regulated stressing rate control tremor genesis, and the same section of fault can slip both with and without detectable tremor, limiting tremor's use as a proxy for slip.

  14. Frictional melt and seismic slip

    NASA Astrophysics Data System (ADS)

    Nielsen, S.; di Toro, G.; Hirose, T.; Shimamoto, T.

    2008-01-01

    Frictional melt is implied in a variety of processes such as seismic slip, ice skating, and meteorite combustion. A steady state can be reached when melt is continuously produced and extruded from the sliding interface, as shown recently in a number of laboratory rock friction experiments. A thin, low-viscosity, high-temperature melt layer is formed resulting in low shear resistance. A theoretical solution describing the coupling of shear heating, thermal diffusion, and extrusion is obtained, without imposing a priori the melt thickness. The steady state shear traction can be approximated at high slip rates by the theoretical form τss = σn1/4 (A/?) ? under a normal stress σn, slip rate V, radius of contact area R (A is a dimensional normalizing factor and W is a characteristic rate). Although the model offers a rather simplified view of a complex process, the predictions are compatible with experimental observations. In particular, we consider laboratory simulations of seismic slip on earthquake faults. A series of high-velocity rotary shear experiments on rocks, performed for σn in the range 1-20 MPa and slip rates in the range 0.5-2 m s-1, is confronted to the theoretical model. The behavior is reasonably well reproduced, though the effect of radiation loss taking place in the experiment somewhat alters the data. The scaling of friction with σn, R, and V in the presence of melt suggests that extrapolation of laboratory measures to real Earth is a highly nonlinear, nontrivial exercise.

  15. Flow-induced vibrations-1987

    SciTech Connect

    Au-Yang, M.K.; Chen, S.S.

    1987-01-01

    This book contains 20 selections. Some of the titles are: Acoustic resonance in heat exchanger tube bundles--Part 1. Physical nature of the phenomenon; Theoretical and experimental studies on heat exchanger U-bend tube bundle vibration characteristics; Experimental model analysis of metallic pipeline conveying fluid; Leakage flow-induced vibration of an eccentric tube-in-tube slip joint; and A study on the vibrations of pipelines caused by internal pulsating flows.

  16. Slipping properties of ceramic tiles / Quantification of slip resistance

    NASA Astrophysics Data System (ADS)

    Terjek, Anita

    2013-12-01

    Regarding the research and application of ceramic tiles there is a great importance of defining precisely the interaction and friction between surfaces. Measuring slip resistance of floor coverings is a complex problem; slipperiness is always interpreted relatively. In the lack of a consistent and clear EU standard, it is practical to use more method in combination. It is necessary to examine the structure of materials in order to get adequate correlation. That is why measuring techniques of surface roughness, an important contributor to slip resistance and cleaning, is fundamental in the research. By comparing the obtained test results, relationship between individual methods of analysis and values may be determined and based on these information recommendations shall be prepared concerning the selection and application of tiles.

  17. Coseismic and postseismic slip of the 2004 Parkfield earthquake from space-geodetic data

    USGS Publications Warehouse

    Johanson, I.A.; Fielding, E.J.; Rolandone, F.; Burgmann, R.

    2006-01-01

    We invert interferometric synthetic aperture radar (InSAR) data jointly with campaign and continuous global positioning system (GPS) data for slip in the coseismic and postseismic periods of the 2004 Parkfield earthquake. The InSAR dataset consists of eight interferograms from data collected by the Envisat and Radarsat satellites spanning the time of the earthquake and variable amounts of the postseismic period. The two datasets complement each other, with the InSAR providing dense sampling of motion in the range direction of the satellite and the GPS providing more sparse, but three-dimensional measurements of ground motion. The model assumes exponential decay of the postseismic slip with a decay time constant of 0.087 years, determined from time series modeling of continuous GPS and creepmeter data. We find a geodetic moment magnitude of M 6.2 for a 1-day coseismic model and Mw 6.1 for the entire postseismic period. The coseismic rupture occurred mainly in two slip asperities; one near the hypocenter and the other 15-20 km north. Postseismic slip occurred on the shallow portions of the fault and near the rupture areas of two M 5.0 aftershocks. A comparison of the geodetic slip models with seismic moment estimates suggests that the coseismic moment release of the Parkfield earthquake is as little as 25% of the total. This underlines the importance of aseismic slip in the slip budget for the Parkfield segment.

  18. Spatial slip behavior of large strike-slip fault belts: Implications for the Holocene slip rates of the eastern termination of the North Anatolian Fault, Turkey

    NASA Astrophysics Data System (ADS)

    Zabcı, Cengiz; Sançar, Taylan; Akyüz, H. Serdar; Kıyak, Nafiye Güneç

    2015-12-01

    We present new data on Holocene slip rates for the eastern end of the North Anatolian Fault (NAF) by using the optically stimulated luminescence ages of the offset terrace deposits at two sites, where a total of four displaced landforms was studied. Each offset feature was analyzed independently, and three different assumptions were made for all the offsets, depending on whether the age of the upper tread (upper tread reconstruction), the lower tread (lower tread reconstruction), or all bounding surfaces (intermediate solution) were used in dating of the terrace risers. The deflected geometry of the risers strongly suggests the use of either the intermediate solution or the upper tread reconstruction. The joint slip rate distributions for the upper tread reconstructions and the intermediate solutions were modeled as 13.0 + 1.8 / -1.4 and 14.3 + 5.8 / -2.4 mm/yr (2σ), respectively. Although the intermediate solution covers the full range of ages for the measured displacements, the curved geometry of the terrace risers suggests that the initiations of the riser offsets are most probably close to the abandonment ages of the upper terrace treads. Therefore, we accepted the joint slip rate of the intermediate solution but suggested that the average rate for the main displacement zone of the eastern NAF should be close to its lower limits. This slower rate with respect to previous estimates suggests that the total deformation is not only accommodated on the main displacement zone but is also distributed along the secondary faults to the south of the easternmost segments of the NAF.

  19. Fault roughness evolution with slip (Gole Larghe Fault Zone, Italian Alps)

    NASA Astrophysics Data System (ADS)

    Bistacchi, A.; Spagnuolo, E.; Di Toro, G.; Nielsen, S. B.; Griffith, W. A.

    2011-12-01

    Fault surface roughness is a principal factor influencing fault and earthquake mechanics. However, little is known on roughness of fault surfaces at seismogenic depths, and particularly on how it evolves with accumulating slip. We have studied seismogenic fault surfaces of the Gole Larghe Fault Zone, which exploit precursor cooling joints of the Adamello tonalitic pluton (Italian Alps). These faults developed at 9-11 km and 250-300°C. Seismic slip along these surfaces, which individually accommodated from 1 to 20 m of net slip, resulted in the production of cm-thick cataclasites and pseudotachylytes (solidified melts produced during seismic slip). The roughness of fault surfaces was determined with a multi-resolution aerial and terrestrial LIDAR and photogrammetric dataset (Bistacchi et al., 2011, Pageoph, doi: 10.1007/s00024-011-0301-7). Fault surface roughness is self-affine, with Hurst exponent H < 1, indicating that faults are comparatively smoother at larger wavelengths. Fault surface roughness is inferred to have been inherited from the precursor cooling joints, which show H ≈ 0.8. Slip on faults progressively modified the roughness distribution, lowering the Hurst exponent in the along-slip direction up to H ≈ 0.6. This behaviour has been observed for wavelengths up to the scale of the accumulated slip along each individual fault surface, whilst at larger wavelengths the original roughness seems not to be affected by slip. Processes that contribute to modify fault roughness with slip include brittle failure of the interacting asperities (production of cataclasites) and frictional melting (production of pseudotachylytes). To quantify the "wear" due to these processes, we measured, together with the roughness of fault traces and their net slip, the thickness and distribution of cataclasites and pseudotachylytes. As proposed also in the tribological literature, we observe that wearing is scale dependent, as smaller wavelength asperities have a shorter

  20. Process for slip casting textured tubular structures

    DOEpatents

    Steinlage, Greg A.; Trumble, Kevin P.; Bowman, Keith J.

    2002-01-01

    A process for centrifugal slip casting a textured hollow tube. A slip made up of a carrier fluid and a suspended powder is introduced into a porous mold which is rotated at a speed sufficient to create a centrifugal force that forces the slip radially outward toward the inner surface of the mold. The suspended powder, which is formed of particles having large dimensional aspect ratios such as particles of superconductive BSCCO, settles in a textured fashion radially outward toward the mold surface. The carrier fluid of the slip passes by capillary action radially outward around the settled particles and into the absorbent mold. A layer of mold release material is preferably centrifugally slip cast to cover the mold inner surface prior to the introduction of the BSCCO slip, and the mold release layer facilitates removal of the BSCCO greenbody from the mold without fracturing.

  1. Multicycle slip distribution along a laboratory fault

    USGS Publications Warehouse

    Chi-Yu, King

    1991-01-01

    Slip distribution along a laboratory fault, which consists of eight spring-connected blocks that are elastically driven to slide on a frictional surface, has been examined for a "long' sequence of slip events to test the applicability of some conceptual models. The distributions of large slip events are found to be quite variable and do not fit the uniform slip or characteristic earthquake models. The rupture initiation points are usually not near the corresponding maximum slip points, in contrast to observations by Thatcher (1990) and by Fukao and Kikuchi (1987) that earthquake hypocenters are commonly near corresponding regions of maximum slip in the fault planes. The results suggest that earthquake prediction monitoring efforts should not be limited to a small region near an asperity but should be spread out to cover the entire fault segment in a seismic gap in order to detect the condition of simultaneous strain buildup. -from Author

  2. Learning to predict slip for ground robots

    NASA Technical Reports Server (NTRS)

    Angelova, Anelia; Matthies, Larry; Helmick, Daniel; Sibley, Gabe; Perona, Pietro

    2006-01-01

    In this paper we predict the amount of slip an exploration rover would experience using stereo imagery by learning from previous examples of traversing similar terrain. To do that, the information of terrain appearance and geometry regarding some location is correlated to the slip measured by the rover while this location is being traversed. This relationship is learned from previous experience, so slip can be predicted later at a distance from visual information only.

  3. Bulk metallic glasses deform via slip avalanches.

    PubMed

    Antonaglia, James; Wright, Wendelin J; Gu, Xiaojun; Byer, Rachel R; Hufnagel, Todd C; LeBlanc, Michael; Uhl, Jonathan T; Dahmen, Karin A

    2014-04-18

    For the first time in metallic glasses, we extract both the exponents and scaling functions that describe the nature, statistics, and dynamics of slip events during slow deformation, according to a simple mean field model. We model the slips as avalanches of rearrangements of atoms in coupled shear transformation zones (STZs). Using high temporal resolution measurements, we find the predicted, different statistics and dynamics for small and large slips thereby excluding self-organized criticality. The agreement between model and data across numerous independent measures provides evidence for slip avalanches of STZs as the elementary mechanism of inhomogeneous deformation in metallic glasses.

  4. Longitudinal wheel slip during ABS braking

    NASA Astrophysics Data System (ADS)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  5. Cycle slipping in phase synchronization systems

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Huang, Lin

    2007-02-01

    Cycle slipping is a characteristically nonlinear phenomenon in phase synchronization systems, which is highly dependent of the initial state of the system. Slipping a cycle means that the phase error is increased to such an extent that the generator to be synchronized slips one complete cycle with respect to the input phase. In this Letter, a linear matrix inequality (LMI) based approach is proposed and the estimation of the number of cycles which slips a solution of the system is obtained by solving a quasi-convex optimization problem of LMI. Applications to phase locked loops demonstrate the validity of the proposed approach.

  6. Development of a liquid metal slip ring

    NASA Technical Reports Server (NTRS)

    Weinberger, S. M.

    1972-01-01

    A liquid metal slip ring/solar orientation mechanism was designed and a model tested. This was a follow-up of previous efforts for the development of a gallium liquid metal slip ring in which the major problem was the formation and ejection of debris. A number of slip ring design approaches were studied. The probe design concept was fully implemented with detail drawings and a model was successfully tested for dielectric strength, shock vibration, acceleration and operation. The conclusions are that a gallium liquid metal slip ring/solar orientation mechanism is feasible and that the problem of debris formation and ejection has been successfully solved.

  7. Bayesian estimation of slip distribution based on von Karman autocorrelation

    NASA Astrophysics Data System (ADS)

    Hooper, A. J.; Bekaert, D. P.

    2014-12-01

    Geodetic observations from techniques such as InSAR and GNSS are routinely used to invert for earthquake fault slip distributions. However, in order to regularize the inversions, extra arbitrary assumptions about the smoothness of the slip distribution are usually included. In previous work we explored a new approach for constraining the slip distribution based on a random vector model following a von Karman autocorrelation function, which has empirical support from a stochastic analysis of seismic finite-source slip inversions. We implemented the random vector constraint in a Bayesian fashion and used a Markov chain Monte Carlo (MCMC) algorithm to derive the posterior joint probability distribution for each of the slipping patches. The von Karman function depends on two parameters: correlation length and Hurst number (related to fractal dimension). In our inversions we used the empirically derived maximum likelihood values for these two parameters, which differ in along-strike and down-dip directions, and with fault mechanism. However, the inversion results depend strongly on the chosen values for correlation length and Hurst number, and the empirically derived histograms show that there is in fact quite some variation between earthquakes with the same mechanism. In our extended approach we treat these two parameters as hyperparameters, with the prior probability distribution constrained by the empirical histograms. The values are thus also allowed to vary in our Bayesian inversion scheme. In this way, the uncertainty in the parameters that define the autocorrelation function is also included in the posterior probability distribution for the slipping patches. To ensure that our MCMC algorithm converges rapidly, we have implemented a variation to the usual MCMC approach, in which the maximum step size for each of the model parameters is initially updated regularly, until optimal values are achieved. In comparisons between our new approach and a more standard

  8. Slipping on pedestrian surfaces: methods for measuring and evaluating the slip resistance.

    PubMed

    Wetzel, Christoph; Windhövel, Ulrich; Mewes, Detlef; Ceylan, Orhan

    2015-01-01

    Tripping, slipping and falling accidents are among the types of accident with a high incidence. This article describes the requirements concerning slip resistance, as well as the state of the art of slip resistance measurement standards in the European Community and the USA. The article also describes how risk assessment can be performed in the field. PMID:26414511

  9. Ice Sheet Stratigraphy Can Constrain Basal Slip

    NASA Astrophysics Data System (ADS)

    Wolovick, M.; Creyts, T. T.; Buck, W. R.; Bell, R. E.

    2014-12-01

    Basal slip is an important component of ice sheet mass flux and dynamics. Basal slip varies over time due to variations in basal temperature, water pressure, and sediment cover. All of these factors can create coherent patterns of basal slip that migrate over time. Our knowledge of the spatial variability in basal slip comes from inversions of driving stress, ice thickness, and surface velocity, but these inversions contain no information about temporal variability. We do not know if the patterns in slip revealed by those inversions move over time. While englacial stratigraphy has classically been used to constrain surface accumulation and geothermal flux, it is also sensitive to horizontal gradients in basal slip. Here we show that englacial stratigraphy can constrain the velocity of basal slip patterns. Englacial stratigraphy responds strongly to patterns of basal slip that move downstream over time close to the ice sheet velocity. In previous work, we used a thermomechanical model to discover that thermally controlled slip patterns migrate downstream and create stratigraphic structures, but we were unable to directly control the pattern velocity, as that arose naturally out of the model physics. Here, we use a kinematic flowline model that allows us to directly control pattern velocity, and thus is applicable to a wide variety of slip mechanisms in addition to basal temperature. We find that the largest and most intricate stratigraphic structures develop when the pattern moves at the column-average ice velocity. Patterns that move slower than the column-average ice velocity produce overturned stratigraphy in the lower part of the ice sheet, while patterns moving at the column-average eventually cause the entire ice sheet to overturn if they persist long enough. Based on these forward models, we develop an interpretive guide for deducing moving patterns in basal slip from ice sheet internal layers. Ice sheet internal stratigraphy represents a potentially vast

  10. Unified slip boundary condition for fluid flows.

    PubMed

    Thalakkottor, Joseph John; Mohseni, Kamran

    2016-08-01

    Determining the correct matching boundary condition is fundamental to our understanding of several everyday problems. Despite over a century of scientific work, existing velocity boundary conditions are unable to consistently explain and capture the complete physics associated with certain common but complex problems, such as moving contact lines and corner flows. The widely used Maxwell and Navier slip boundary conditions make an implicit assumption that velocity varies only in the wall normal direction. This makes their boundary condition inapplicable in the vicinity of contact lines and corner points, where velocity gradient exists both in the wall normal and wall tangential directions. In this paper, by identifying this implicit assumption we are able to extend Maxwell's slip model. Here, we present a generalized velocity boundary condition that shows that slip velocity is a function of not only the shear rate but also the linear strain rate. In addition, we present a universal relation for slip length, which shows that, for a general flow, slip length is a function of the principal strain rate. The universal relation for slip length along with the generalized velocity boundary condition provides a unified slip boundary condition to model a wide range of steady Newtonian fluid flows. We validate the unified slip boundary for simple Newtonian liquids by using molecular dynamics simulations and studying both the moving contact line and corner flow problems. PMID:27627398

  11. Unified slip boundary condition for fluid flows

    NASA Astrophysics Data System (ADS)

    Thalakkottor, Joseph John; Mohseni, Kamran

    2016-08-01

    Determining the correct matching boundary condition is fundamental to our understanding of several everyday problems. Despite over a century of scientific work, existing velocity boundary conditions are unable to consistently explain and capture the complete physics associated with certain common but complex problems, such as moving contact lines and corner flows. The widely used Maxwell and Navier slip boundary conditions make an implicit assumption that velocity varies only in the wall normal direction. This makes their boundary condition inapplicable in the vicinity of contact lines and corner points, where velocity gradient exists both in the wall normal and wall tangential directions. In this paper, by identifying this implicit assumption we are able to extend Maxwell's slip model. Here, we present a generalized velocity boundary condition that shows that slip velocity is a function of not only the shear rate but also the linear strain rate. In addition, we present a universal relation for slip length, which shows that, for a general flow, slip length is a function of the principal strain rate. The universal relation for slip length along with the generalized velocity boundary condition provides a unified slip boundary condition to model a wide range of steady Newtonian fluid flows. We validate the unified slip boundary for simple Newtonian liquids by using molecular dynamics simulations and studying both the moving contact line and corner flow problems.

  12. Analysis of minor fractures associated with joints and faulted joints

    NASA Astrophysics Data System (ADS)

    Cruikshank, Kenneth M.; Zhao, Guozhu; Johnson, Arvid M.

    In this paper, we use fracture mechanics to interpret conditions responsible for secondary cracks that adorn joints and faulted joints in the Entrada Sandstone in Arches National Park, U.S.A. Because the joints in most places accommodated shearing offsets of a few mm to perhaps 1 dm, and thus became faulted joints, some of the minor cracks are due to faulting. However, in a few places where the shearing was zero, one can examine minor cracks due solely to interaction of joint segments at the time they formed. We recognize several types of minor cracks associated with subsequent faulting of the joints. One is the kink, a crack that occurs at the termination of a straight joint and whose trend is abruptly different from that of the joint. Kinks are common and should be studied because they contain a great deal of information about conditions during fracturing. The sense of kinking indicates the sense of shear during faulting: a kink that turns clockwise with respect to the direction of the main joint is a result of right-lateral shear, and a kink that turns counterclockwise is a result of left-lateral shear. Furthermore, the kink angle is related to the ratio of the shear stress responsible for the kinking to the normal stress responsible for the opening of the joint. The amount of opening of a joint at the time it faulted or even at the time the joint itself formed can be estimated by measuring the kink angle and the amount of strike-slip at some point along the faulted joint. Other fractures that form near terminations of pre-existing joints in response to shearing along the joint are horsetail fractures. Similar short fractures can occur anywhere along the length of the joints. The primary value in recognizing these fractures is that they indicate the sense of faulting accommodated by the host fracture and the direction of maximum tension. Even where there has been insignificant regional shearing in the Garden Area, the joints can have ornate terminations. Perhaps

  13. [Evaporating Droplet and Imaging Slip Flows

    NASA Technical Reports Server (NTRS)

    Larson, R. G.

    2002-01-01

    In this report, we summarize work on Evaporating Droplet and Imaging Slip Flows. The work was primarily performed by post-doc Hue Hu, and partially by grad students Lei Li and Danish Chopra. The work includes studies on droplet evaporation and its effects on temperature and velocity fields in an evaporating droplet, new 3-D microscopic particle image velocimetry and direct visualization on wall slip in a surfactant solution. With the exception of the slip measurements, these projects were those proposed in the grant application. Instead of slip flow, the original grant proposed imaging electro-osmotic flows. However, shortly after the grant was issued, the PI became aware of work on electro-osmotic flows by the group of Saville in Princeton that was similar to that proposed, and we therefore elected to carry out work on imaging slip flows rather than electro-osmotic flows.

  14. The role of water in slip casting

    NASA Technical Reports Server (NTRS)

    Mccauley, R. A.; Phelps, G. W.

    1984-01-01

    Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.

  15. Slow slip generated by dehydration reaction coupled with slip-induced dilatancy and thermal pressurization

    NASA Astrophysics Data System (ADS)

    Yamashita, Teruo; Schubnel, Alexandre

    2016-05-01

    Sustained slow slip, which is a distinctive feature of slow slip events (SSEs), is investigated theoretically, assuming a fault embedded within a fluid-saturated 1D thermo-poro-elastic medium. The object of study is specifically SSEs occurring at the down-dip edge of seismogenic zone in hot subduction zones, where mineral dehydrations (antigorite, lawsonite, chlorite, and glaucophane) are expected to occur near locations where deep slow slip events are observed. In the modeling, we introduce dehydration reactions, coupled with slip-induced dilatancy and thermal pressurization, and slip evolution is assumed to interact with fluid pressure change through Coulomb's frictional stress. Our calculations show that sustained slow slip events occur when the dehydration reaction is coupled with slip-induced dilatancy. Specifically, slow slip is favored by a low initial stress drop, an initial temperature of the medium close to that of the dehydration reaction equilibrium temperature, a low permeability, and overall negative volume change associated with the reaction (i.e., void space created by the reaction larger than the space occupied by the fluid released). Importantly, if we do not assume slip-induced dilatancy, slip is accelerated with time soon after the slip onset even if the dehydration reaction is assumed. This suggests that slow slip is sustained for a long time at hot subduction zones because dehydration reaction is coupled with slip-induced dilatancy. Such slip-induced dilatancy may occur at the down-dip edge of seismogenic zone at hot subduction zones because of repetitive occurrence of dehydration reaction there.

  16. Multicycle slip distribution along a laboratory fault

    NASA Astrophysics Data System (ADS)

    King, Chi-Yu

    1991-08-01

    Slip distribution along a laboratory fault, which consists of eight spring-connected blocks that are elastically driven to slide on a frictional surface, has been examined for a "long" sequence of slip events to test the applicability of some conceptual models proposed recently in the literature. The distributions of large slip events are found to be quite variable and do not fit the uniform slip or characteristic earthquake models. The rupture initiation points are usually not near the corresponding maximum slip points, in contrast to observations by Thatcher (1990) and by Fukao and Kikuchi (1987) that earthquake hypocenters are commonly near corresponding regions of maximum slip in the fault planes. This contrast may suggest that either the present observations or theirs are not representative or the teleseismically determined hypocenters may not always be true rupture initiation points as usually assumed. Large slip events are also found to be a stress-roughening process. They are triggered by some small events after the stresses have been adjusted by some earlier small-to-moderate events to be near the critical levels at most locations along the fault. This suggests that earthquake prediction monitoring efforts should not be limited to a small region near an asperity but should be spread out to cover the entire fault segment in a seismic gap in order to detect the condition of simultaneous strain buildup.

  17. Maximum slip in earthquake fault zones, apparent stress, and stick-slip friction

    USGS Publications Warehouse

    McGarr, A.; Fletcher, Joe B.

    2003-01-01

    The maximum slip, observed or inferred, for a small patch within the larger fault zone of an earthquake is a remarkably well-constrained function of the seismic moment. A large set of maximum slips, mostly derived from slip models of major earthquakes, indicate that this parameter increases according to the cube root of the seismic moment. Consistent with this finding, neither the average slip rate for the patches of maximum slip nor the apparent stresses of earthquakes show any systematic dependence on seismic moment. Maximum average slip rates are several meters per second independent of moment and, for earthquakes in continental crustal settings, the apparent stress is limited to about 10 MPa. Results from stick-slip friction experiments in the laboratory, combined with information about the state of stress in the crust, can be used to predict, quite closely, the maximum slips and maximum average slip rates within the fault zones of major earthquakes as well as their apparent stresses. These findings suggest that stick-slip friction events observed in the laboratory and earthquakes in continental settings, even with large magnitudes, have similar rupture mechanisms.

  18. Effective slip-length tensor for a flow over weakly slipping stripes.

    PubMed

    Asmolov, Evgeny S; Zhou, Jiajia; Schmid, Friederike; Vinogradova, Olga I

    2013-08-01

    We discuss the flow past a flat heterogeneous solid surface decorated by slipping stripes. The spatially varying slip length, b(y), is assumed to be small compared to the scale of the heterogeneities, L, but finite. For such weakly slipping surfaces, earlier analyses have predicted that the effective slip length is simply given by the surface-averaged slip length, which implies that the effective slip-length tensor becomes isotropic. Here we show that a different scenario is expected if the local slip length has steplike jumps at the edges of slipping heterogeneities. In this case, the next-to-leading term in an expansion of the effective slip-length tensor in powers of max[b(y)/L] becomes comparable to the leading-order term, but anisotropic, even at very small b(y)/L. This leads to an anisotropy of the effective slip and to its significant reduction compared to the surface-averaged value. The asymptotic formulas are tested by numerical solutions and are in agreement with results of dissipative particle dynamics simulations.

  19. Dynamical Stability of Slip-stacking Particles

    SciTech Connect

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-04

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  20. Dynamical stability of slip-stacking particles

    NASA Astrophysics Data System (ADS)

    Eldred, Jeffrey; Zwaska, Robert

    2014-09-01

    We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We find perturbative solutions for stable particle trajectories. We establish Booster beam quality requirements to achieve 97% slip-stacking efficiency. We show that slip-stacking dynamics directly correspond to the driven pendulum and to the system of two standing-wave traps moving with respect to each other.

  1. Friction of water slipping in carbon nanotubes.

    PubMed

    Ma, Ming D; Shen, Luming; Sheridan, John; Liu, Jefferson Zhe; Chen, Chao; Zheng, Quanshui

    2011-03-01

    Liquid slip is essential in nanofluidic systems, as shrinking channel size leads to a dramatic increase in flow resistance and thus high-energy consumption for driving nonslip flow. Using large-scale nonequilibrium molecular dynamics simulation of water flowing in carbon nanotubes (CNT's), we show that the relationship between the CNT wall-water interfacial friction stress and slip velocity follows a transition-state-theory-based inverse hyperbolic sine function, which remains universally valid regardless of wetting properties, CNT chiralities, and CNT sizes, and holds for all slip velocities from 0 to 1400 m/s. The finding could benefit the research in desalination and other chemical purification techniques.

  2. Slow slip event at Kilauea Volcano

    USGS Publications Warehouse

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford

    2010-01-01

    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  3. Electrostatic precursors to granular slip events

    PubMed Central

    Shinbrot, Troy; Kim, Nam H.; Thyagu, N. Nirmal

    2012-01-01

    It has been known for over a century that electrical signals are produced by material failure, for example during crack formation of crystals and glasses, or stick-slip motion of liquid mercury on glass. We describe here new experiments revealing that slip events in cohesive powders also produce electrical signals, and remarkably these signals can appear significantly in advance of slip events. We have confirmed this effect in two different experimental systems and using two common powdered materials, and in a third experiment we have demonstrated that similar voltage signals are produced by crack-like defects in several powdered materials. PMID:22689956

  4. Slip Development and Instability on a Heterogeneously Loaded Fault with Power-Law Slip-Weakening

    NASA Astrophysics Data System (ADS)

    Rice, J. R.; Uenishi, K.

    2002-12-01

    We consider slip initiation and rupture instability on planar faults that follow a non-linear slip-weakening relation and are subjected to a locally peaked loading stress, the level of which changes quasi-statically in time. For the case in which strength weakens linearly with slip, Uenishi and Rice [2002] (http://esag.harvard.edu/uenishi/research/nl/nl.html) have shown there exists a universal length of the slipping region at instability, independent of any length scales entering into the description of the shape of the loading stress distribution. Here we study slip development and its (in)stability for a power-law slip-weakening relation, giving fault strength as τ = τ p - Aδn where τ p is the peak strength at which slip initiates, δ is the slip, and A is a constant. Such a form with n ≈ 0.2-0.4 has been inferred, for slips from 1 to 500 mm, as an interpretation of seismological observations on the scaling of radiated energy with slip [Abercrombie and Rice, EOS, 2001; SCEC, 2002]. It is also consistent with laboratory experiments involving large rotary shear [Chambon et al., GRL, 2002]. We first employed an energy approach to give a Rayleigh-Ritz approximation for the dependence of slipping length and maximum slip on the level and shape of the loading stress distribution. That was done for a loading stress distribution τ p + Rt - κ x2 / 2 where x is distance along the fault, κ is a constant, and Rt is the stress change from that for which the peak in the loading stress distribution equals the strength τ p. Results show there is no longer a universal nucleation length, independent of κ , when n != 1, and that qualitative features of the slip development are significantly controlled by n. We also obtained full numerical solutions for the slip development. Remarkably, predictions of the simple energy approach are in reasonable quantitative agreement with them and give all qualitative features correctly. Principal results are as follows: If n > 2/3, the

  5. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  6. Slipped epiphyses in renal osteodystrophy.

    PubMed Central

    Mehls, O; Ritz, E; Krempien, B; Gilli, G; Link, K; Willich, E; Schärer, K

    1975-01-01

    Clinical, biochemical, roentgenological, and histological features of slipped epiphyses (epiphysiolysis) in 11 out of 112 children with renal osteodystrophy have been analysed. Characteristic age-related patterns of involvement of different epiphyses are described. Quantitative measurements of iliac bone histology, serum parathyroid hormone levels, and clinical history show the presence of more advanced osteitis fibrosa in children with epiphysiolysis than in those without. A good correlation was found between serum parathormone levels and osteoclastic resorption, endosteal fibrosis as well as osteoid. Histological studies show that the radiolucent zone between the epiphyseal ossification centre and the metaphysis in x-rays is not caused by accumulation of cartilage and chondro-osteoid (as usually found in vitamin D deficiency rickets) but by the accumulation of woven bone and/or fibrous tissue. The response to vitamin D therapy in most cases was good. Parathyroidectomy was required in only one case. Images FIG. 1. FIG. 2. p549-b FIG. 3. FIG. 4. FIG. 5. FIG. 6. FIG. 7. PMID:1167068

  7. Is slow slip in Cascadia tidally modulated?

    NASA Astrophysics Data System (ADS)

    Hawthorne, J. C.; Rubin, A. M.

    2009-12-01

    Several studies have shown that the seismic tremor in episodic tremor and slip is tidally modulated, suggesting a strong sensitivity to the rather small tidal stresses. We address whether the slip is also tidally modulated by examining data from six borehole strainmeters in northwest Washington and southern Vancouver Island. We use the processed data provided by Plate Boundary Observatory (PBO), which is resampled to 5-minute intervals. However, we recompute empirical corrections for tides, a long-term linear trend, and barometric pressure in the 50 days surrounding each slow slip event. We then fit sinusoids at the tidal periods to the processed data as proxies for the tidally modulated component of slip, along with a linear trend as a proxy for the net strain in the slow slip. The data are too noisy to allow detection any tidal modulation using only a single event and station. We therefore simultaneously fit data from multiple stations and from three slow slip events since 2007. This assumes that the phase of the tides at the slipping regions detected by all stations is the same and that the phase of the fault response to the tidal stress is constant. Combining the stations and events both reduces the noise at the tidal periods and creates a longer time series, which allows us to separate energy at the different tidal frequencies. We find significant tidal signals at the 12.4 and 25.8-hour periods which differ from zero at the 1.5 to 2-sigma level. Errors are estimated by bootstrapping the slow slip strain and by considering the tidal signal at times before the slow slip event. The 12.4 and 25.8-hour sinusoids have amplitudes of 23 (10-40 at 2-sigma) and 15 (0-30 at 2-sigma) percent of the maximum amplitude that does not allow the slow slip strain signal to change sign, where the mean strain rate is estimated from the linear trends fit to the slow slip data. In terms of slip rate, the sinusoids at each period could then modulate the slip rate 23 and 15 percent

  8. Slip compensation at fault damage zones along earthquake surface ruptures

    NASA Astrophysics Data System (ADS)

    Choi, J.; Kim, Y.

    2013-12-01

    Surface ruptures associated with earthquake faulting commonly comprise a number of segments, and the discontinuities form tip and linking damage zones, which are deformed regions consisting of secondary features. Stress transferring or releasing, when seismic waves pass through the discontinuities, could produce different slip features depending on rupture propagation or termination. Thus, slip patterns at fault damage zones can be one of the key factors to understand fault kinematics, fault evolution and, hence, earthquake hazard. In some previous studies (e.g. Peacock and Sanderson, 1991; Kim and Sanderson, 2005), slip distribution along faults to understand the connectivity or maturity of segmented faults system have commonly been analyzed based on only the main slip components (dip-slip or strike-slip). Secondary slip components, however, are sometimes dominant at fault damage zones, such as linkage and tip zones. In this study, therefore, we examine slip changes between both main and secondary slip components along unilaterally propagated coseismic strike-slip ruptures. Horizontal and vertical components of slip and the slip compensation patterns at tip and linking damage zones are various from slip deficit (decrease in both slip components) through slip compensation (increase of vertical slip with horizontal slip decrease) to slip neutral. Front and back tip zones, which are classified depending on main propagation direction of earthquake ruptures, show different slip patterns; slip compensation is observed at the frontal tip whilst slip deficit occurs at the back tip zone. Average values of the two slip components and their compensative patterns at linking damage zones are closely related with the ratio of length to width (L/W) of linkage geometry; the horizontal slip is proportional to the ratio of L/W, whilst the vertical slip shows little dependence on the value L/W. When the L/W is greater than ~2, average values of two slip components are almost similar

  9. Subgrain boundaries and slip systems in quartz

    NASA Astrophysics Data System (ADS)

    Kilian, Rüdiger

    2015-04-01

    At elevated temperatures, quartz usually deforms by dislocation glide and dislocation creep. Textures (crystallographic preferred orientations) and microstructures are commonly used to infer the kinematics and physical conditions of deformation. However, it is debatable whether a given texture, represented by a pole figure, is universally indicative of a specific deformation temperature or recrystallization mechanism or e.g. is rather related to strain. Quartz veins in synkinematic, felsic dikes from the footwall of the Mohave Wash detachment fault in the Chemehuevi Mountains are studied by EBSD, CIP and universal stage. Mm-sized quartz grains are homogeneously stretched with aspect ratios of up to 30. Minor recrystallization takes place by subgrain rotation. Three different groups of highly stretched quartz grains can be defined: Grains with peripheral c-axes at a high angle to the foliation (Z-grains), grains with central c-axes perpendicular to the lineation (Y-grains) and grains with c-axes intermediately between the former two (O-grains). The three types of grains do not show a significant difference in their aspect ratios. Bulk pole figures show a kinked single c-axes girdle with a central maximum and an a-axes maximum parallel to the lineation. Misorientation analysis and the orientation of subgrain boundaries are used to make inferences on slip systems. Z-grains are interpreted to be suitable for basal (c)-slip, Y-grains for prism {m}-slip, which is compatible with the bulk misorientation distribution function of entire grains. O-grains could be interpreted as suitably oriented for rhomb {r/z/pi/pi'} slip, however, this is not supported by the bulk misorientation distribution function. Individual subgrain boundaries in Y-grains and Z-grains expected for the 'easy' slip systems {m} and (c) with tilt character ({a} parallel boundaries with [c] or misorientation axes, respectively), are limited to small (< 2°) misorientation angles

  10. Slip-mediated dewetting of polymer microdroplets

    PubMed Central

    McGraw, Joshua D.; Chan, Tak Shing; Maurer, Simon; Salez, Thomas; Benzaquen, Michael; Raphaël, Elie; Brinkmann, Martin; Jacobs, Karin

    2016-01-01

    Classical hydrodynamic models predict that infinite work is required to move a three-phase contact line, defined here as the line where a liquid/vapor interface intersects a solid surface. Assuming a slip boundary condition, in which the liquid slides against the solid, such an unphysical prediction is avoided. In this article, we present the results of experiments in which a contact line moves and where slip is a dominating and controllable factor. Spherical cap-shaped polystyrene microdroplets, with nonequilibrium contact angle, are placed on solid self-assembled monolayer coatings from which they dewet. The relaxation is monitored using in situ atomic force microscopy. We find that slip has a strong influence on the droplet evolutions, both on the transient nonspherical shapes and contact line dynamics. The observations are in agreement with scaling analysis and boundary element numerical integration of the governing Stokes equations, including a Navier slip boundary condition. PMID:26787903

  11. Falls study: Proprioception, postural stability, and slips.

    PubMed

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls.

  12. Falls study: Proprioception, postural stability, and slips.

    PubMed

    Sohn, Jeehoon; Kim, Sukwon

    2015-01-01

    The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls. PMID:26406065

  13. Coseismic slip distribution of the 1946 Nankai earthquake and aseismic slips caused by the earthquake

    NASA Astrophysics Data System (ADS)

    Tanioka, Yuichiro; Satake, Kenji

    2001-04-01

    Coseismic slip distribution on the fault plane of the 1946 Nankai earthquake ( M w 8.3) was estimated from inversion of tsunami waveforms. The following three improvements from the previous study (Satake, 1993) were made. (1) Larger number of smaller subfaults is used; (2) the subfaults fit better to the slab geometry; and (3) more detailed bathymetry data are used. The inversion result shows that the agreement between observed and synthetic waveforms is greatly improved from the previous study. In the western half of the source region off Shikoku, a large slip of about 6 m occurred near the down-dip end of the locked zone. The slip on the up-dip or shallow part was very small, indicating a weak seismic coupling in that region. In the eastern half of the source region off Kii peninsula, a large slip of about 3 m extended over the entire locked zone. Large slips on the splay faults in the upper plate estimated from geodetic data (Sagiya and Thatcher, 1999) were not required to explain the tsunami waveforms, suggesting that the large slips were aseismic. Two slip distributions on the down-dip end of the plate interface, one from geodetic data and the other from tsunami waveforms, agree well except for slip beneath Cape Muroto in Shikoku. This suggests that aseismic slip also occurred on the plate interface beneath Cape Muroto.

  14. Nonlinear dynamical triggering of slow slip

    SciTech Connect

    Johnson, Paul A; Knuth, Matthew W; Kaproth, Bryan M; Carpenter, Brett; Guyer, Robert A; Le Bas, Pierre - Yves; Daub, Eric G; Marone, Chris

    2010-12-10

    Among the most fascinating, recent discoveries in seismology have been the phenomena of triggered slip, including triggered earthquakes and triggered-tremor, as well as triggered slow, silent-slip during which no seismic energy is radiated. Because fault nucleation depths cannot be probed directly, the physical regimes in which these phenomena occur are poorly understood. Thus determining physical properties that control diverse types of triggered fault sliding and what frictional constitutive laws govern triggered faulting variability is challenging. We are characterizing the physical controls of triggered faulting with the goal of developing constitutive relations by conducting laboratory and numerical modeling experiments in sheared granular media at varying load conditions. In order to simulate granular fault zone gouge in the laboratory, glass beads are sheared in a double-direct configuration under constant normal stress, while subject to transient perturbation by acoustic waves. We find that triggered, slow, silent-slip occurs at very small confining loads ({approx}1-3 MPa) that are smaller than those where dynamic earthquake triggering takes place (4-7 MPa), and that triggered slow-slip is associated with bursts of LFE-like acoustic emission. Experimental evidence suggests that the nonlinear dynamical response of the gouge material induced by dynamic waves may be responsible for the triggered slip behavior: the slip-duration, stress-drop and along-strike slip displacement are proportional to the triggering wave amplitude. Further, we observe a shear-modulus decrease corresponding to dynamic-wave triggering relative to the shear modulus of stick-slips. Modulus decrease in response to dynamical wave amplitudes of roughly a microstrain and above is a hallmark of elastic nonlinear behavior. We believe that the dynamical waves increase the material non-affine elastic deformation during shearing, simultaneously leading to instability and slow-slip. The inferred

  15. Comparison of co-seismic and post-seismic slip of large earthquakes in southern Peru and northern Chile

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Ji, C.; Simons, M.; Klotz, J.

    2003-12-01

    We use InSAR, GPS, and seismic data to constrain the location of co-seismic and post-seismic slip on the subduction interface in southern Peru and northern Chile. We focus on the July 30, 1995, {M}w~8.1 and the January 30, 1998, {M}w~7.1 northern Chile earthquakes as well as the November 12, 1996, {M}w~7.7 and June 23, 2001, {M}w~8.4 southern Peru earthquakes. For all four earthquakes, we invert body-wave seismic waveforms and geodetic data (InSAR for all earthquakes and GPS where available) both jointly and separately for co-seismic slip. In northern Chile, we constrain the temporal and spatial evolution of post-seismic after-slip using about 30 interferograms spanning 1995-2000 and GPS data from the German SAGA array (spanning 1995-1997, including vertical displacements). In southern Peru, we use InSAR data, and GPS data from the Arequipa station to constrain post-seismic after-slip. Comparison of these events provides insight into the rupture process of large subduction zone earthquakes and the mechanisms of post-seismic after-slip. The plate tectonic setting for all the earthquakes is similar (convergence rate, plate age, etc.), but the amount of post-seismic after-slip is different. There is significant slip after the 2001 earthquake (equivalent to approximately 20% of the co-seismic moment), but compared to other recent subduction zone earthquakes, there is little slip following the other three events. The different amounts of post-seismic slip are not obviously related to differences in the dynamic ruptures of each event, but might be related to along-strike variations in material properties (like sediment thickness).

  16. Constraining Paleoearthquake Slip Distributions with Coral Microatolls

    NASA Astrophysics Data System (ADS)

    Lindsay, A.; McCloskey, J.; nic Bhloscaidh, M.; Murphy, S.

    2014-12-01

    Key to understanding the threat posed by large megathrust earthquakes is identifying where the potential for these destructive events exists. Studying extended sequences of earthquakes, Slip Deficit and Stress Evolution modelling techniques may hold the key to locating areas of concern. However, as well as using recent instrumentally constrained slip distributions they require the production of high resolution source models for pre-instrumental events. One place we can attempt this longer term modelling is along the Sunda Trench with its record of large megathrust earthquakes dating back centuries. Coral microatolls populating the intertidal areas of the Sumatran Forearc act as long-term geodetic recorders of tectonic activity. Repeated cycles of stress accumulation and release alter relative sea levels around these islands. Growth of corals, controlled by the level of the lowest tide, exploit interseismic rises in sea level. In turn, they experience die-offs when coseismic drops in sea level lead to subaerially exposure. Examination of coral stratigraphy reveals a history of displacements from which information of past earthquakes can be inferred. We have developed a Genetic Algorithm Slip Estimator (GASE) to rapidly produce high resolution slip distributions from coral displacement data. GASE recombines information held in populations of randomly generated slip distributions, to create superior models, satisfying observed displacements. Non-unique solutions require multiple iterations of the algorithm, producing a suite of models from which an ensemble slip distribution is drawn. Systematic testing of the algorithm demonstrates its ability to reliably estimate both known synthetic and instrumentally constrained slip distributions based on surface displacements. We will present high-resolution source models satisfying published displacement data for a number recent and paleoearthquakes along the Sunda trench, including the great 1797 and 1833 events.

  17. The influence of footwear sole hardness on slip characteristics and slip-induced falls in young adults.

    PubMed

    Tsai, Yi-Ju; Powers, Christopher M

    2013-01-01

    Theoretically, a shoe that provides less friction could result in a greater slip distance and foot slipping velocity, thereby increasing the likelihood of falling. The purpose of this study was to investigate the effects of sole hardness on the probability of slip-induced falls. Forty young adults were randomized into a hard or a soft sole shoe group, and tested under both nonslippery and slippery floor conditions using a motion analysis system. The proportions of fall events in the hard- and soft-soled shoe groups were not statistically different. No differences were observed between shoe groups for average slip distance, peak and average heel velocity, and center of mass slipping velocity. A strong association was found between slip distance and the fall probability. Our results demonstrate that the probability of a slip-induced fall was not influenced by shoe hardness. Once a slip is induced, slip distance was the primary predictor of a slip-induced fall.

  18. Kids' Slips: What Young Children's Slips of the Tongue Reveal about Language Development

    ERIC Educational Resources Information Center

    Jaeger, Jeri J.

    2005-01-01

    The study of speech errors, or "slips of the tongue," is a time-honored methodology which serves as a window to the representation and processing of language and has proven to be the most reliable source of data for building theories of speech production planning. However, until "Kids' Slips," there has never been a corpus of such errors from…

  19. Digital slip frequency generator and method for determining the desired slip frequency

    DOEpatents

    Klein, Frederick F.

    1989-01-01

    The output frequency of an electric power generator is kept constant with variable rotor speed by automatic adjustment of the excitation slip frequency. The invention features a digital slip frequency generator which provides sine and cosine waveforms from a look-up table, which are combined with real and reactive power output of the power generator.

  20. Is frictional healing slip-dependent?

    NASA Astrophysics Data System (ADS)

    Bhattacharya, P.; Rubin, A. M.; Ryan, K. L.; Riviere, J. V.; Marone, C.

    2015-12-01

    Frictional re-strengthening of bare rock surfaces at very low stresses and near zero slip rate, as observed in the laboratory, is traditionally interpreted as showing support for purely time-dependent healing as embodied in the Aging law. However, while slide-hold-slide experiments on bare surfaces do show an apparent (purely) time-dependent increase in the static friction upon reslide, we show that the stress minima attained during the preceding holds show a strong slip-dependence which contradict the Aging law. A velocity strengthening Slip law explains such data much better. We also show that, large velocity step decreases, which drive the system far below steady state just like long holds, clearly support the slip-dependent response of the Slip law over the time-dependent healing contained in the Aging law. But, while time-dependent healing has an intuitive physical picture in terms of growth of the 'real contact area' with time, it is more difficult to ascribe one to slip-dependent healing. Here, we explore the possibility that the slip-dependence arises out of an interplay between contact `quality' and `quantity' at the scale of the asperity contacts. First, to further study the slip-dependence of healing, we carry out large velocity step decreases and sequences of long slide-hold-slides on both bare rock and gouge. Secondly, to probe the micro-mechanical origins of healing, we complement our mechanical data with amplitudes and travel time data of ultrasonic P- and S- waves transmitted across the sliding interface. While ultrasonic P-wave transmissivity has been used as a proxy for 'real contact area' in friction experiments by Nagata et al. (2012, 2014) before, the simultaneous use of P- and S-phases in our experiments is designed specifically to probe contact rheology. Initial results show strong correlations between changes in friction, transmitted wave amplitudes and travel times in response to changes in slip rate. We also observe important differences

  1. Fault zone roughness controls slip stability

    NASA Astrophysics Data System (ADS)

    Harbord, Christopher; Nielsen, Stefan; De Paola, Nicola

    2016-04-01

    Fault roughness is an important control factor in the mechanical behaviour of fault zones, in particular the frictional slip stability and subsequent earthquake nucleation. Despite this, there is little experimental quantification as to the effects of varying roughness upon rate- and state-dependant friction (RSF). Utilising a triaxial deformation apparatus and a novel adaptation of the direct shear methodology to simulate initially bare faults in Westerly Granite, we performed a series of velocity step frictional sliding experiments. Initial root mean square roughnesses (Sq) was varied in the range 6x10-7 - 2.4x10-5 m. We also investigated the effects upon slip stability of normal stress variation in the range σn = 30 - 200 MPa, and slip velocity between 0.1 - 10 μm s-1. A transition from stable sliding to unstable slip (manifested by stick-slip and slow slip events) was observed, depending on the parameter combination, thus covering the full spectrum of fault slip behaviours. At low normal stress (σn = 30MPa) smooth faults (Sq< 1x10-6 m) are conditional unstable (stress drops on slow slip events upon velocity increase), with strongly velocity weakening friction. When normal stress is increased to intermediate values (σn = 100 - 150 MPa), smooth faults (Sq< 1x10-6 m) are fully unstable and generate seismic stick-slip behaviour. However at higher normal stress (σn = 200 MPa) a transition from unstable to stable sliding is observed for smooth faults, which is not expected using RSF stability criteria. At all conditions sliding is stable for rough faults (Sq> 1x10-6 m). We find that instability can develop when the ratio of fault to critical stiffness kf kc > 10, or, alternatively, even when a - b > 0 at σn = 150MPa, suggesting that bare surfaces may not strictly obey the R+S stability condition. Additionally we present white light interferometry and SEM analysis of experimentally deformed samples which provide information about the distribution and physical

  2. Discrete Element Modeling of Stick-Slip Instability and Induced Microseismicity

    NASA Astrophysics Data System (ADS)

    Khazaei, Cyrus; Hazzard, Jim; Chalaturnyk, Rick

    2016-03-01

    Using Particle Flow Code, a discrete element model is presented in this paper that allows direct modeling of stick-slip behavior in pre-existing weak planes such as joints, beddings, and faults. The model is used to simulate a biaxial sliding experiment from literature on a saw-cut specimen of Sierra granite with a single fault. The fault is represented by the smooth-joint contact model. Also, an algorithm is developed to record the stick-slip induced microseismic events along the fault. Once the results compared well with laboratory data, a parametric study was conducted to investigate the evolution of the model's behavior due to varying factors such as resolution of the model, particle elasticity, fault coefficient of friction, fault stiffness, and normal stress. The results show a decrease in shear strength of the fault in the models with smaller particles, smaller coefficient of friction of the fault, harder fault surroundings, softer faults, and smaller normal stress on the fault. Also, a higher rate of displacement was observed for conditions resulting in smaller shear strength. An increase in b-values was observed by increasing the resolution or decreasing the normal stress on the fault, while b-values were not sensitive to changes in elasticity of the fault or its surrounding region. A larger number of recorded events were observed for the models with finer particles, smaller coefficient of friction of the fault, harder fault surroundings, harder fault, and smaller normal stress on the fault. The results suggest that it is possible for the two ends of a fault to be still while there are patches along the fault undergoing stick-slips. Such local stick-slips seem to provide a softer surrounding for their neighbor patches facilitating their subsequent stick-slips.

  3. Slip in viscous contact-line movement

    NASA Astrophysics Data System (ADS)

    van Lengerich, Henrik; Steen, Paul; Breuer, Kenneth

    2011-11-01

    The typical continuum fluid dynamics formulation cannot be used to model the spreading of a liquid on a solid because a stress singularity prevents contact-line motion. It is well known that this situation can be remedied by introducing a slip. We perform Stokes-flow simulations with slip and compare these with experiments. In the experiment, liquid (squalane) is forced through two parallel sapphire plates (roughness 0.6nm), and the meniscus shape and its speed are measured. The slip-length for this liquid/solid pair has been measured previously in an independent experiment absent of contact lines (T. Schmatko et. al. PRL 94, 244501). The same geometry is used in a boundary integral method simulation, accurate to within a few molecular diameters in the vicinity of the contact-line. The slip-length in the simulations can be varied such that the meniscus shape matches the experiment. Preliminary results suggest this slip-length is an order of magnitude lower than that reported by Schmatko. Now at the University of Minnesota TC

  4. Breddin's Graph For Fault and Slip Data

    NASA Astrophysics Data System (ADS)

    Célérier, B.

    A simple plot of rake versus strike of fault and slip or earthquake focal mechanism data provides insight into the stress regime that caused slippage on these faults provided one of the principal stress direction is near vertical. By overlaying an abacus on this plot, one can evaluate both the orientation of the horizontal principal stress directions and the stress tensor aspect ratio, (s1-s2)/(s1-s3), where s1, s2, s3 are the principal stress magnitudes ranked in decreasing order. The underlying geometrical properties are that the slip data that are near strike-slip, and that are mainly found on steeply dipping planes, constrain the horizontal principal stress directions whereas the slip data that are near dip-slip and that occur on shallow dipping planes striking away from the principal stress directions constrain the stress tensor aspect ratio. This abacus is an extension of the Breddin's abacus used to analyze two dimensional deformation in structural geology and it is used in a similar fashion. Its application to synthetic and natural monophase data show both its usefulness and limitation. It is not intended to replace stress inversion techniques because of limiting assumptions, but it is expected to provide insight into the complexity of natural data set from a simple viewpoint.

  5. Smoothing and roughening of slip surfaces in direct shear experiments

    NASA Astrophysics Data System (ADS)

    Sagy, Amir; Badt, Nir; Hatzor, Yossef H.

    2015-04-01

    Faults in the upper crust contain discrete slip surfaces which have absorbed a significant part of the shear displacement along them. Field measurements demonstrate that these surfaces are rough at all measurable scales and indicate that surfaces of relatively large-slip faults are statistically smoother than those of small-slip faults. However, post faulting and surface erosion process that might affect the geometry of outcrops cannot be discounted in such measurements. Here we present experimental results for the evolution of shear surface topography as function of slip distance and normal stress in direct shear experiments. A single prismatic fine grain limestone block is first fractured in tension mode using the four-point bending test methodology and then the fracture surface topography is scanned using a laser profilometer. We then shear the obtained tensile fracture surfaces in direct shear, ensuring the original fracture surfaces are in a perfectly matching configuration at the beginning of the shear test. First, shearing is conducted to distances varying from 5 to 15 mm under constant normal stress of 2MPa and a constant displacement rate of 0.05 mm/s using two closed-loop servo controlled hydraulic pistons, supplying normal and shear forces (Davidesko et al., 2014). In the tested configuration peak shear stress is typically attained after a shear displacement of about 2-3 mm, beyond which lower shear stress is required to continue shearing at the preset displacement rate of 0.05 mm/s as is typical for initially rough joints. Following some initial compression the interface begins to dilate and continues to do so until the end of the test. The sheared tensile fracture surface is then scanned again and the geometrical evolution, in term of RMS roughness and power spectral density (PSD) is analyzed. We show that shearing smooth the surface along all our measurements scales. The roughness ratio, measured by initial PSD / final PSD for each wavelength

  6. Evidence for slip partitioning and bimodal slip behavior on a single fault: Surface slip characteristics of the 2013 Mw7.7 Balochistan, Pakistan earthquake

    NASA Astrophysics Data System (ADS)

    Barnhart, W. D.; Briggs, R. W.; Reitman, N. G.; Gold, R. D.; Hayes, G. P.

    2015-06-01

    Deformation is commonly accommodated by strain partitioning on multiple, independent strike-slip and dip-slip faults in continental settings of oblique plate convergence. As a corollary, individual faults tend to exhibit one sense of slip - normal, reverse, or strike-slip - until whole-scale changes in boundary conditions reactivate preexisting faults in a new deformation regime. In this study, we show that a single continental fault may instead partition oblique strain by alternatively slipping in a strike-slip or a dip-slip sense during independent fault slip events. We use 0.5 m resolution optical imagery and sub-pixel correlation analysis of the 200 + km 2013 Mw7.7 Balochistan, Pakistan earthquake to document co-seismic surface slip characteristics and Quaternary tectonic geomorphology along the causative Hoshab fault. We find that the 2013 earthquake, which involved a ∼6:1 strike-slip to dip-slip ratio, ruptured a structurally segmented fault. Quaternary geomorphic indicators of gross fault-zone morphology reveal both reverse-slip and strike-slip deformation in the rupture area of the 2013 earthquake that varies systematically along fault strike despite nearly pure strike-slip motion in 2013. Observations of along-strike variations in range front relief and geomorphic offsets suggest that the Hoshab fault accommodates a substantial reverse component of fault slip in the Quaternary, especially along the southern section of the 2013 rupture. We surmise that Quaternary bimodal slip along the Hoshab fault is promoted by a combination of the arcuate geometry of the Hoshab fault, the frictional weakness of the Makran accretionary prism, and time variable loading conditions from adjacent earthquakes and plate interactions.

  7. Slip rate and slip magnitudes of past earthquakes along the Bogd left-lateral strike-slip fault (Mongolia)

    USGS Publications Warehouse

    Rizza, M.; Ritz, J.-F.; Braucher, R.; Vassallo, R.; Prentice, C.; Mahan, S.; McGill, S.; Chauvet, A.; Marco, S.; Todbileg, M.; Demberel, S.; Bourles, D.

    2011-01-01

    We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, the principal structure involved in the Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Bogd Fault is 260 km long and can be subdivided into five main geometric segments, based on variation in strike direction. West to East these segments are, respectively: the West Ih Bogd (WIB), The North Ih Bogd (NIB), the West Ih Bogd (WIB), the West Baga Bogd (WBB) and the East Baga Bogd (EBB) segments. Morphological analysis of offset streams, ridges and alluvial fans-particularly well preserved in the arid environment of the Gobi region-allows evaluation of late Quaternary slip rates along the different faults segments. In this paper, we measure slip rates over the past 200 ka at four sites distributed across the three western segments of the Bogd Fault. Our results show that the left-lateral slip rate is ~1 mm yr-1 along the WIB and EIB segments and ~0.5 mm yr-1 along the NIB segment. These variations are consistent with the restraining bend geometry of the Bogd Fault. Our study also provides additional estimates of the horizontal offset associated with the 1957 earthquake along the western part of the Bogd rupture, complementing previously published studies. We show that the mean horizontal offset associated with the 1957 earthquake decreases progressively from 5.2 m in the west to 2.0 m in the east, reflecting the progressive change of kinematic style from pure left-lateral strike-slip faulting to left-lateral-reverse faulting. Along the three western segments, we measure cumulative displacements that are multiples of the 1957 coseismic offset, which may be consistent with a characteristic slip. Moreover, using these data, we re-estimate the moment magnitude of the Gobi-Altay earthquake at Mw 7.78-7.95. Combining our slip rate estimates and the slip distribution per event we also determined a mean recurrence interval of ~2500-5200 yr for past

  8. Slip rate and slip magnitudes of past earthquakes along the Bogd left-lateral strike-slip fault (Mongolia)

    USGS Publications Warehouse

    Prentice, Carol S.; Rizza, M.; Ritz, J.F.; Baucher, R.; Vassallo, R.; Mahan, S.

    2011-01-01

    We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, the principal structure involved in the Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Bogd Fault is 260 km long and can be subdivided into five main geometric segments, based on variation in strike direction. West to East these segments are, respectively: the West Ih Bogd (WIB), The North Ih Bogd (NIB), the West Ih Bogd (WIB), the West Baga Bogd (WBB) and the East Baga Bogd (EBB) segments. Morphological analysis of offset streams, ridges and alluvial fans—particularly well preserved in the arid environment of the Gobi region—allows evaluation of late Quaternary slip rates along the different faults segments. In this paper, we measure slip rates over the past 200 ka at four sites distributed across the three western segments of the Bogd Fault. Our results show that the left-lateral slip rate is∼1 mm yr–1 along the WIB and EIB segments and∼0.5 mm yr–1 along the NIB segment. These variations are consistent with the restraining bend geometry of the Bogd Fault. Our study also provides additional estimates of the horizontal offset associated with the 1957 earthquake along the western part of the Bogd rupture, complementing previously published studies. We show that the mean horizontal offset associated with the 1957 earthquake decreases progressively from 5.2 m in the west to 2.0 m in the east, reflecting the progressive change of kinematic style from pure left-lateral strike-slip faulting to left-lateral-reverse faulting. Along the three western segments, we measure cumulative displacements that are multiples of the 1957 coseismic offset, which may be consistent with a characteristic slip. Moreover, using these data, we re-estimate the moment magnitude of the Gobi-Altay earthquake at Mw 7.78–7.95. Combining our slip rate estimates and the slip distribution per event we also determined a mean recurrence interval of∼2500

  9. Ceramic joints

    DOEpatents

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  10. Quake clamps down on slow slip

    NASA Astrophysics Data System (ADS)

    Wallace, Laura M.; Bartlow, Noel; Hamling, Ian; Fry, Bill

    2014-12-01

    Using continuous GPS (cGPS) data from the Hikurangi subduction zone in New Zealand, we show for the first time that stress changes induced by a local earthquake can arrest an ongoing slow slip event (SSE). The cGPS data show that the slip rate in the northern portion of the 2013/2014 Kapiti SSE decreased abruptly following a nearby intraslab earthquake. We suggest that deceleration of the Kapiti SSE in early 2014 occurred due to a tenfold increase in the normal stress relative to shear stress in the SSE source, induced by the nearby Mw 6.3 earthquake, consistent with expectations of rate and state friction. Our observation of an abrupt halting/slowing of the SSE in response to stress changes imposed by a local earthquake has implications for the strength of fault zones hosting SSEs and supports the premise that static stress changes are an important ingredient in triggering (or delaying) fault slip.

  11. Slip, Crystal Orientation, and Damage Evolution During Thermal Cycling in High-Strain Wafer-Level Chip-Scale Packages

    NASA Astrophysics Data System (ADS)

    Zhou, Bite; Zhou, Quan; Bieler, Thomas R.; Lee, Tae-kyu

    2015-03-01

    Wafer-level chip-scale package samples with pre-cross-sectioned edge rows were thermally cycled to study microstructure evolution and damage development. Electron backscattered diffraction (EBSD) and high-energy x-ray diffraction were used to obtain Sn grain orientations and the average coefficient of thermal expansion normal to the board in every joint of the package for samples in the as-fabricated and thermally cycled conditions. The results indicated a near-random distribution of joint orientation. Optical, scanning electron microscopy, and EBSD methods were used to characterize microstructure changes in pre-cross-sectioned samples due to thermal cycling. Slip trace analysis and Orientation Imaging Microscopy™ (OIM) show that slip systems with high Schmid factors (estimated global shear stress based on the package neutral point) are responsible for the observed microstructure evolution during thermal cycling, which provides information about slip systems that are more easily activated. Two joints were analyzed in detail to evaluate slip activity at different stages of their thermal history. The first case showed that a solidification twin grain boundary misorientation deviated from the twin relationship due to slip activity during thermal cycling, which can influence damage development and the path of crack propagation. The second case showed a new grain orientation developing due to gradual lattice rotation about the Sn [110] axis by a continuous recrystallization mechanism. This rotation was correlated with the operation of slip system . Small tin whiskers emerged from the initially polished chip interface and grew with increasing thermal cycles until a crack developed in the solder that relieved the stress. As the local stresses are not known experimentally, this analysis provides observations that can be compared with a crystal plasticity model simulation.

  12. A Bayesian inversion for slip distribution of 1 Apr 2007 Mw8.1 Solomon Islands Earthquake

    NASA Astrophysics Data System (ADS)

    Chen, T.; Luo, H.

    2013-12-01

    On 1 Apr 2007 the megathrust Mw8.1 Solomon Islands earthquake occurred in the southeast pacific along the New Britain subduction zone. 102 vertical displacement measurements over the southeastern end of the rupture zone from two field surveys after this event provide a unique constraint for slip distribution inversion. In conventional inversion method (such as bounded variable least squares) the smoothing parameter that determines the relative weight placed on fitting the data versus smoothing the slip distribution is often subjectively selected at the bend of the trade-off curve. Here a fully probabilistic inversion method[Fukuda,2008] is applied to estimate distributed slip and smoothing parameter objectively. The joint posterior probability density function of distributed slip and the smoothing parameter is formulated under a Bayesian framework and sampled with Markov chain Monte Carlo method. We estimate the spatial distribution of dip slip associated with the 1 Apr 2007 Solomon Islands earthquake with this method. Early results show a shallower dip angle than previous study and highly variable dip slip both along-strike and down-dip.

  13. GREEN REACTION CHEMISTRIES PERFORMED IN THE SPINNING TUBE-IN-TUBE (STT) REACTOR

    EPA Science Inventory

    The U. S. Environmental Protection Agency (USEPA) and Kreido Laboratories have established a Cooperative Research and Development Agreement (CRADA) collaboration, to develop and commercialize green and sustainable chemistries in the area of industrial chemical synthesis. Utilizi...

  14. PROCESS INTENSIFIED GREEN REACTION CHEMISTRIES PERFORMED IN THE SPINNING TUBE-IN-TUBE (STT®) REACTOR

    EPA Science Inventory

    The U. S. Environmental Protection Agency (USEPA) and Kreido Laboratories have established a Cooperative Research and Development Agreement (CRADA) collaboration, to develop and commercialize green and sustainable chemistries in the area of industrial chemical synthesis. Utilizi...

  15. SYNTHESIS OF ORGANIC EPOXIDES USING A SPINNING TUBE-IN-TUBE REACTOR

    EPA Science Inventory

    The U.S. Environmental Protectiion Agency (USEPA) and Kreido Laboratories have established a Cooperative Research and Development Agreement (CRADA) collaboration, to develop and commercialize green and sustainable chemistries in the area of industrial chemcial synthesis. The STT...

  16. Organic Synthesis in a Spinning Tube-in-Tube (STT¢) Reactor

    EPA Science Inventory

    Continuous-flow reactors have been designed to minimize and potentially overcome the limitations of heat and mass transfer that are encountered in chemical reactors and further experienced upon scale up of a reaction. With process intensification, optimization of the reaction i...

  17. Coseismic Dip Slip Distribution of the 1 Apr 2007 Solomon Islands Mw8.1 Earthquake from a Fully Bayesian Inversion

    NASA Astrophysics Data System (ADS)

    Chen, T.

    2009-12-01

    102 uplift and subsidence measurements over the southeastern end of the rupture zone from two field surveys shortly after 1 Apr 2007 Solomon Islands Earthquake provide a unique geodetic constraint in the following inversion of distributed slip. In the conventional inversion of geodetic data for spatial distribution of fault slip the solution is maintained by minimizing the second-order spatial derivative of slip and the smoothing parameter is often selected subjectively at the bend of the trade-off curve of misfit as a function of slip roughness. A fully Bayesian slip inversion method[Fukuda et al.,2008] is used to overcome the deficiency of selecting the smoothing parameter subjectively. The smoothing parameter is estimated with the distributed slip at the same time under a unified theoretical Bayesian framework. The joint posterior probability density function of distributed slip and smoothing parameter is formulated using Bayes’ theorem and sampled with Markov chain Monte Carlo method. I will apply this method to coseismic slip distribution associated with the 2007 Mw8.1 Solomon Islands earthquake and compare the results of this method with conventional method and the coseismic finite fault model of Furlong et al.[2009].

  18. The mechanics of stick-slip

    USGS Publications Warehouse

    Byerlee, J.D.

    1970-01-01

    Physical mechanisms that have been proposed to explain the occurrence of stick-slip motion during frictional sliding have been examined in the light of results obtained from experiments with rocks and brittle minerals. An instability caused by sudden brittle fracture of locked regions on surfaces in contact is the most likely explanation for stick-slip during dry frictional sliding of brittle rocks at room temperature. Areas requiring further study and the uncertainties in applying the results of laboratory experiments to earthquake studies are emphasized. ?? 1970.

  19. Slip length measurement of gas flow.

    PubMed

    Maali, Abdelhamid; Colin, Stéphane; Bhushan, Bharat

    2016-09-16

    In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas. PMID:27505860

  20. Slipping magnetic reconnection in coronal loops.

    PubMed

    Aulanier, Guillaume; Golub, Leon; Deluca, Edward E; Cirtain, Jonathan W; Kano, Ryouhei; Lundquist, Loraine L; Narukage, Noriyuki; Sakao, Taro; Weber, Mark A

    2007-12-01

    Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments. PMID:18063789

  1. Slip length measurement of gas flow

    NASA Astrophysics Data System (ADS)

    Maali, Abdelhamid; Colin, Stéphane; Bhushan, Bharat

    2016-09-01

    In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas.

  2. Slip length measurement of gas flow.

    PubMed

    Maali, Abdelhamid; Colin, Stéphane; Bhushan, Bharat

    2016-09-16

    In this paper, we present a review of the most important techniques used to measure the slip length of gas flow on isothermal surfaces. First, we present the famous Millikan experiment and then the rotating cylinder and spinning rotor gauge methods. Then, we describe the gas flow rate experiment, which is the most widely used technique to probe a confined gas and measure the slip. Finally, we present a promising technique using an atomic force microscope introduced recently to study the behavior of nanoscale confined gas.

  3. Momentum compaction and phase slip factor

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2010-10-01

    Section 2.3.11 of the Handbook of Accelerator Physics and Engineering on Landau damping is updated. The slip factor and its higher orders are given in terms of the various orders of the momentum compaction. With the aid of a simplified FODO lattice, formulas are given for the alteration of the lower orders of the momentum compaction by various higher multipole magnets. The transition to isochronicity is next demonstrated. Formulas are given for the extraction of the first three orders of the slip factor from the measurement of the synchrotron tune while changing the rf frequency. Finally bunch-length compression experiments in semi-isochronous rings are reported.

  4. Slipping processes in residual badlands reliefs

    NASA Astrophysics Data System (ADS)

    Díaz-Hernández, Jose Luis; Yepes, Jorge

    2010-05-01

    We define slips as structures developed by more or less saturated colloidal suspension that slide down the walls of residual reliefs found in badlands. These suspensions seem to originate in the soils crowning gully reliefs and also from rainwater dripping onto the walls of poorly cemented sediments such as siltstone. We call this process slipping and the resulting morphologies represent a group of minor badlands forms, often linked to piping and fluting. Slipping occurs according to the following sequence of forms: 1. Mud droplets. These are irregular linear structures caused by mud droplets sliding down sub-vertical walls. The droplet is usually found at the end of a small channel. These morphologies represent the course of the sliding droplets that become fossilized and not the impact of the droplets on the sediment. 2. Slips sensu stricto. These are uninterrupted surface structures covering sub-vertical walls to a greater or lesser extent. The thickness of this type of covering varies from a few millimetres to 5cm. The inner structure of the slips consists of small laminas (» 100mm) and on the exterior they often present drip channels. A special case of these forms is butterfly structures, which appear in isolation, with repetitive patterns and the appearance of a winged insect stuck to the wall. 3. Pseudo-stalactites. These are free-standing conical regrowths with some similarity to stalactites in a karst cave. They occur when slips grow to over 5cm thick. The growth of these forms is similar to that of slips, with external superposition of fine, concentric layers with no central pore. A variety of these pseudo-stalactites are nodulous stalactites whose genesis is unknown. In this context, we should mention the existence of occasional stalagmites. In other cases, curtains of pseudo-stalactites can be found where these patterns are repeated finely. A more evolved stage of this form is the coalescence of pseudo-stalactites, representing a massive advance of

  5. Temporomandibular Joint, Closed

    MedlinePlus

    ... Oral Health > The Temporomandibular Joint, Closed The Temporomandibular Joint, Closed Main Content Title: The Temporomandibular Joint, Closed Description: The temporomandibular joint connects the lower ...

  6. Asymmetric alluvial fans along strike-slip faults: A potential slip-rate record?

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    We investigate the phenomenon of asymmetric alluvial fan morphology along strike-slip faults. From analysis of high-resolution topographic data, we find that asymmetric alluvial fans are common along several strike-slip faults in the western United States. Affected fans are steeper in the direction of translation of the sediment source, often resulting in stream deflections counter to that expected from the sense of fault slip (e.g. left deflected streams along dextral faults). We hypothesize that fan asymmetry results from lateral translation of the sediment source relative to the depocenter. This relative motion changes the accommodation space in such a way that one side of the alluvial fan continuously progrades while the other is gradually abandoned. Therefore, lateral translation results in radial asymmetry of slopes about the fan apex. As a first approximation, we model this asymmetry as a result of diffusive sediment transport down fan. From this analysis, we predict that the degree of asymmetry of the alluvial fan is controlled by the ratio of sediment flux to fault slip rate. Qualitatively, more rapidly slipping faults should host more highly asymmetric fans; conversely, high sediment flux will obscure asymmetry. By measuring the sediment flux, through catchment-average concentration of cosmogenic isotopes or other means, we show that it is theoretically possible to quantify strike-slip fault slip-rates and alluvial-fan sediment transport rates using alluvial fan morphometry.

  7. Slip development and instability on a nonuniformly loaded interface with power-law slip-weakening

    NASA Astrophysics Data System (ADS)

    Rice, James R.; Uenishi, Koji

    2003-03-01

    We study rupture instability on a planar interface subjected to a locally peaked stress that increases quasi-statically in time. The interface follows a nonlinear slip-weakening relation where the strength drop is proportional to (slip)^n. Such a form with n 0.2-0.4 has been inferred from seismological observations on the scaling of radiated energy with slip (Abercrombie and Rice, 2001, 2002) and similarly abrupt strength drops are found at slips greater than sub-mm range in experiments involving large rotary shear (Chambon et al., 2002; Tullis and Goldsby, 2002). We use a simple Rayleigh-Ritz method and also full numerical simulations. Results show there is no longer a universal nucleation length when n ne 1 and qualitative features of the slip development are controlled by n. If n < 2/3, instability occurs as soon as the peaked value of the loading reaches the strength. This is a prediction based on the power law starting at (slip) = 0^+ whereas the observational results correspond to slips beyond the sub-mm range.

  8. Slip rates across the sinistral slip fault system of the Shan Plateau, northern SE Asia

    NASA Astrophysics Data System (ADS)

    Shi, X.; Sieh, K.; Wang, Y.; Liu, J.; Weldon, R. J.; Feng, L.; Chan, C. H.

    2015-12-01

    The sinistral-slip fault system of the Shan Plateau, arcing around the eastern Himalayan syntaxis and extending > 700 km from northwest to southeast, poses a high seismic hazard in northern SE Asia. Knowing slip rates and earthquake recurrence intervals of these faults is key to better quantification of that hazard. However, estimates of slip rates along the fault system remain poorly constrained. Here we report a preliminary estimate of the slip rate across the fault system from available campaign GPS velocities. We projected the horizontal GPS velocity vectors relative to the Sunda block reference frame perpendicular to the general strike (~ 240°) of the sinistral faults. The velocity profile shows a gradient of ~ 9 mm/yr over a distance of ~ 550 km that crosses 8 faults, from the Dayingjiang fault in the northwest to the Mengxing fault in the southeast. This suggests the average slip rate across each fault in the system is ~ 1 mm/yr. The 9 mm/yr of GPS velocity gradient across the fault system, however, is only half of the long-term rates determined from offsets of major rivers, ridges and plutons. These geological determinations suffer, however, from poor dating constraints. The discrepancy between the geodetic and geological analyses highlights the need of reliable constraints on slip rates along each of the faults. We have begun field work aimed at determining the slip rate of one of these, the Jinghong fault.

  9. Update on slip and wear in multi-layer azimuth track systems

    NASA Astrophysics Data System (ADS)

    Juneja, Gunjeet; Kan, Frank W.; Antebi, Joseph

    2006-06-01

    Many antennas, such as the 100-m Green Bank Telescope, use a wheel-on-track systems in which the track segments consist of wear plates mounted on base plates. The wear plates are typically 2 to 3 inches thick and are case hardened or through hardened. The base plates are usually 3 to 4 times thicker than the wear plates and are not hardened. The wear plates are typically connected to the base plates using bolts. The base plates are supported on grout and anchored to the underlying concrete foundation. For some antennas, slip has been observed between the wear plate and base plate, and between the base plate and the grout, with the migration in the wheel rolling direction. In addition, there has been wear at the wear plate/base plate interface. This paper is an update on the evaluation of GBT track retrofit. The paper describes the use of three-dimensional non-linear finite element analyses to understand and evaluate the behavior of (1) the existing GBT wheel-on-track system with mitered joints, and (2) the various proposed modifications. The modifications include welding of the base plate joints, staggering of the wear plate joints from the base plate joints, changing thickness of the wear plate, and increasing bolt diameter and length. Parameters included in the evaluation were contact pressure, relative slip, wear at the wear plate/base plate interface, and bolt shears and moments.

  10. Geodetic, teleseismic, and strong motion constraints on slip from recent southern Peru subduction zone earthquakes

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Norabuena, E. O.; Ji, C.; Boroschek, R.; Comte, D.; Simons, M.; Dixon, T. H.; Rosen, P. A.

    2007-03-01

    We use seismic and geodetic data both jointly and separately to constrain coseismic slip from the 12 November 1996 Mw 7.7 and 23 June 2001 Mw 8.5 southern Peru subduction zone earthquakes, as well as two large aftershocks following the 2001 earthquake on 26 June and 7 July 2001. We use all available data in our inversions: GPS, interferometric synthetic aperture radar (InSAR) from the ERS-1, ERS-2, JERS, and RADARSAT-1 satellites, and seismic data from teleseismic and strong motion stations. Our two-dimensional slip models derived from only teleseismic body waves from South American subduction zone earthquakes with Mw > 7.5 do not reliably predict available geodetic data. In particular, we find significant differences in the distribution of slip for the 2001 earthquake from models that use only seismic (teleseismic and two strong motion stations) or geodetic (InSAR and GPS) data. The differences might be related to postseismic deformation or, more likely, the different sensitivities of the teleseismic and geodetic data to coseismic rupture properties. The earthquakes studied here follow the pattern of earthquake directivity along the coast of western South America, north of 5°S, earthquakes rupture to the north; south of about 12°S, directivity is southerly; and in between, earthquakes are bilateral. The predicted deformation at the Arequipa GPS station from the seismic-only slip model for the 7 July 2001 aftershock is not consistent with significant preseismic motion.

  11. Inertial aided cycle slip detection and identification for integrated PPP GPS and INS.

    PubMed

    Du, Shuang; Gao, Yang

    2012-10-25

    The recently developed integrated Precise Point Positioning (PPP) GPS/INS system can be useful to many applications, such as UAV navigation systems, land vehicle/machine automation and mobile mapping systems. Since carrier phase measurements are the primary observables in PPP GPS, cycle slips, which often occur due to high dynamics, signal obstructions and low satellite elevation, must be detected and repaired in order to ensure the navigation performance. In this research, a new algorithm of cycle slip detection and identification has been developed. With the aiding from INS, the proposed method jointly uses WL and EWL phase combinations to uniquely determine cycle slips in the L1 and L2 frequencies. To verify the efficiency of the algorithm, both tactical-grade and consumer-grade IMUs are tested by using a real dataset collected from two field tests. The results indicate that the proposed algorithm can efficiently detect and identify the cycle slips and subsequently improve the navigation performance of the integrated system.

  12. Compliant joint

    NASA Technical Reports Server (NTRS)

    Eklund, Wayne D. (Inventor); Kerley, James J. (Inventor)

    1990-01-01

    A compliant joint is provided for prosthetic and robotic devices which permits rotation in three different planes. The joint provides for the controlled use of cable under motion. Perpendicular outer mounting frames are joined by swaged cables that interlock at a center block. Ball bearings allow for the free rotation of the second mounting frame relative to the first mounting frame within a predetermined angular rotation that is controlled by two stop devices. The cables allow for compliance at the stops and the cables allow for compliance in six degrees of freedom enabling the duplication or simulation of the rotational movement and flexibility of a natural hip or knee joint, as well as the simulation of a joint designed for a specific robotic component for predetermined design parameters.

  13. Joint Commission

    MedlinePlus

    ... Sunday 1:00 CST, November 6, 2016 Workplace Violence Prevention Resources The Joint Commission has launched “Workplace Violence Prevention Resources,” an online resource center dedicated to ...

  14. Joint Problems

    MedlinePlus

    ... ankles and toes. Other types of arthritis include gout or pseudogout. Sometimes, there is a mechanical problem ... for more information on osteoarthritis, rheumatoid arthritis and gout. How Common are Joint Problems? Osteoarthritis, which affects ...

  15. Slip casting and nitridation of silicon powder

    NASA Technical Reports Server (NTRS)

    Seiko, Y.

    1985-01-01

    Powdered Silicon was slip-cast with a CaSO4 x 0.5H2O mold and nitrided in a N atm. containing 0 or 5 vol. % H at 1000 to 1420 deg. To remove the castings, the modeling faces were coated successively with an aq. salt soap and powdered cellulose containing Na alginate, and thus prevented the sticking problem.

  16. PRODUCTION OF SLIP CAST CALCIA HOLLOWWARE

    DOEpatents

    Stoddard, S.D.; Nuckolls, D.E.; Cowan, R.E.

    1963-12-31

    A method for producing slip cast calcia hollow ware in which a dense calcia grain is suspended in isobutyl acetate or a mixture of tertiary amyl alcohol and o-xylene is presented. A minor amount of triethanolamine and oleic acid is added to the suspension vehicle as viscosity adjusting agents and the suspension is cast in a plaster mold, dried, and fired. (AEC)

  17. Hydrodynamic slip length as a surface property.

    PubMed

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G P

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems. PMID:26986407

  18. Oblique slip in Laramide foreland arches

    SciTech Connect

    Erslev, E.A.; Selvig, B.; Molzer, P. . Dept. of Earth Resources)

    1993-03-01

    Don Wise was one of the first structural geologists to recognize the complex, four-dimensional (space and time) nature of basement-involved faulting in the Rocky Mountain foreland. His focus on both small scale kinematic indicators and regional tectonic hypotheses has provided a launching point for many Rocky Mountain geologists. The implications of the anastomosing patterns of Laramide foreland arches on models of regional stress and strain have provoked considerable debate. Hypotheses range from those invoking multiple stages of lateral compression from different directions to single-stage models necessitating a component of strike-slip motion in east-west and north-south arches. These hypotheses were tested using slickenline analysis of minor faulting in structures with different orientations. In Wyoming, structures paralleling the dominant northwest structural trend have slickenlines in the NE-SW vertical plane, consistent with shortening and compression in this direction. The east-west Owl Creek and Casper Mountain structures also have NE-SW trending slickenlines, indicating slip oblique to these arches. In Colorado, minor faults in the north-south margin of the northeastern Front Range also indicate oblique slip, with shortening in the NE-SW quadrant. The actual trend of the slickenlines is more easterly, however, suggesting a change of slip trajectory with latitude, not time, possibly in response to identation by the Colorado Plateau.

  19. Hydrodynamic slip length as a surface property

    NASA Astrophysics Data System (ADS)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems.

  20. Slip Dynamics in Small Scale Crystals

    NASA Astrophysics Data System (ADS)

    Maass, Robert; Derlet, Peter; Greer, Julia; Volkert, Cynthia

    2015-03-01

    Classical work showed that dislocation velocities are strongly dependent on applied stress. Numerous experiments have validated this for individual or groups of dislocations in macroscopic crystals by using imaging techniques combined with either mechanical data or time resolved topological data. Developments in small scale mechanical testing allow to correlate the intermittency of collective dislocation motion with the mechanical response. Discrete forward surges in displacement can be related to dislocation avalanches, which are triggered by the evolving dislocation sub-structure. We study the spatiotemporal characteristics of intermittent plastic flow in quasi-statically sheared single crystalline Au crystals with diameters between 300 nm and 10000 nm, whose displacement bursts were recorded at several kHz (Scripta Mater. 2013, 69, 586; Small, available online). Both the crystallographic slip magnitude, as well as the velocity of the slip events are exhibiting power-law scaling as. The obtained slip velocity distribution has a cubic decay at high values, and a saturated flat shoulder at lower velocities. No correlation between the slip velocity and the applied stress or plastic strain is found. Further, we present DD-simulations that are supportive of our experimental findings. The simulations suggest that the dynamics of the internal stress fields dominate the evolving dislocation structure leading to velocities that are insensitive to the applied stress - a regime indicative of microplasticity.

  1. Hydrodynamic slip length as a surface property.

    PubMed

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G P

    2016-02-01

    Equilibrium and nonequilibrium molecular dynamics simulations were conducted in order to evaluate the hypothesis that the hydrodynamic slip length is a surface property. The system under investigation was water confined between two graphite layers to form nanochannels of different sizes (3-8 nm). The water-carbon interaction potential was calibrated by matching wettability experiments of graphitic-carbon surfaces free of airborne hydrocarbon contamination. Three equilibrium theories were used to calculate the hydrodynamic slip length. It was found that one of the recently reported equilibrium theories for the calculation of the slip length featured confinement effects, while the others resulted in calculations significantly hindered by the large margin of error observed between independent simulations. The hydrodynamic slip length was found to be channel-size independent using equilibrium calculations, i.e., suggesting a consistency with the definition of a surface property, for 5-nm channels and larger. The analysis of the individual trajectories of liquid particles revealed that the reason for observing confinement effects in 3-nm nanochannels is the high mobility of the bulk particles. Nonequilibrium calculations were not consistently affected by size but by noisiness in the smallest systems.

  2. Spatial variations in slip deficit on the central San Andreas Fault from InSAR

    NASA Astrophysics Data System (ADS)

    Ryder, Isabelle; Bürgmann, Roland

    2008-12-01

    We use ERS InSAR measurements to record spatial variations in creep rate along the creeping segment of the San Andreas Fault (SAF), California, between 1992 and 2001. Inversion of geodetic data yields a slip rate distribution along the creeping segment, which is used for first-order moment release and deficit calculations. We present a time-averaged spatial picture of surface deformation and associated subsurface creep. An interferometric stack is constructed from 12 interferograms that show good coherence. For the decade of observation, the total right-lateral offset spanned by the data is ~34 mmyr-1. Along most of the length of the creeping segment, this offset occurs within a narrow (<2 km) zone close to the fault trace. In the northern part, a minor part of the offset is taken up by the nearby Calaveras-Paicines Fault. In general, the observed rates of surface creep are consistent with those obtained by several other studies for a longer and/or earlier period of time, using different geodetic methods. This suggests that the average creep rate has been constant over a period of almost four decades. A joint GPS-InSAR inversion implies that the shallow creep rate is variable along strike, reaching up to 31.5 +/- 1 mmyr-1 in the central section of the creeping segment, tapering off along-strike to the south and becoming partitioned across two subparallel faults in the north. The deep slip rate beneath the seismogenic layer is 33 +/- 3 mmyr-1. The difference between shallow and deep slip rates suggests that there is a shallow slip deficit on the creeping segment of the SAF (CSAF). Moment release rate due to aseismic slip is approximately three orders of magnitude greater than seismic moment release. The annual creep on the CSAF is equivalent to the moment released in a M 6 earthquake. The equivalent moment of the slip deficit relative to the deep slip rate is between 4.1 × 1017 and 8.4 × 1017 N myr-1, which is equivalent to a magnitude 5.7-5.9 earthquake. Over a

  3. The structure of slip-pulses and supershear ruptures driving slip in bimaterial friction

    NASA Astrophysics Data System (ADS)

    Shlomai, Hadar; Fineberg, Jay

    2016-06-01

    The most general frictional motion in nature involves bimaterial interfaces, when contacting bodies possess different elastic properties. Frictional motion occurs when the contacts composing the interface separating these bodies detach via propagating rupture fronts. Coupling between slip and normal stress variations is unique to bimaterial interfaces. Here we use high speed simultaneous measurements of slip velocities, real contact area and stresses to explicitly reveal this bimaterial coupling and its role in determining different classes of rupture modes and their structures. We directly observe slip-pulses, highly localized slip accompanied by large local reduction of the normal stress near the rupture tip. These pulses propagate in the direction of motion of the softer material at a selected (maximal) velocity and continuously evolve while propagating. In the opposite direction bimaterial coupling favors crack-like `supershear' fronts. The robustness of these structures shows the importance of bimaterial coupling to frictional motion and modes of frictional dissipation.

  4. Experimental Slip Events as Possible Proxies for Fault Patch Slip During Earthquakes

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2011-12-01

    The slip and strength histories of a fault patch during an earthquake are experimentally simulated with a high-speed rotary apparatus. The experimental fault comprises two solid cylindrical blocks with a raised-ring contact of 7 cm diameter and 1 cm width. Our conceptual model assumes that slip on a fault patch is initiated by the stress increase associated with the passage of an earthquake front, and that this slip is facilitated by dissipation of potential energy stored in the surrounding crust. To simulate this process in the laboratory, we first store kinetic energy by spinning up a 225 kg flywheel that is adjacent to, but not connected to, the locked fault. Then, the flywheel is engaged to the lower fault block via a fast-acting (<0.03 s) clutch, and the drive motor is turned off. This loading procedure produces slip behavior that has many similarities to the slip envisioned to occur along an earthquake patch. (1) In both cases, a finite energy is available to drive slip. (2) The initial dynamic stress rise leading to fault slip is rapid (<< 1 s). (3) Slip history is controlled by spontaneous interaction between fault strength and the stored energy. (4) Radiated seismic energy is probably a small fraction of the energy budget. We refer to our experiments as 'Earthquake-Like-Slip-Event' or ELSE. Direct measurements of slip-velocity, normal and shear stresses, fault-normal displacement, and temperature are recorded at 5 kHz sampling. We present synthesis of 43 ELSE runs with Sierra White granite, and 15 with Kasota dolomite. Samples were axially loaded up to 7 MPa, potential energy up to 25 MJ/m^2, and slip-velocity up to ~1.0 m/s; they produced slip-distances up to 5.55 m, and fault-normal displacement from -300 microns (closure) to 160 microns (dilation). The main ELSE observations and inferences are: (1) In most experiments, the strength drops significantly (~50-70%) during the early slip stage, and this weakening is associated with intense fault wear and

  5. The structure of slip-pulses and supershear ruptures driving slip in bimaterial friction

    PubMed Central

    Shlomai, Hadar; Fineberg, Jay

    2016-01-01

    The most general frictional motion in nature involves bimaterial interfaces, when contacting bodies possess different elastic properties. Frictional motion occurs when the contacts composing the interface separating these bodies detach via propagating rupture fronts. Coupling between slip and normal stress variations is unique to bimaterial interfaces. Here we use high speed simultaneous measurements of slip velocities, real contact area and stresses to explicitly reveal this bimaterial coupling and its role in determining different classes of rupture modes and their structures. We directly observe slip-pulses, highly localized slip accompanied by large local reduction of the normal stress near the rupture tip. These pulses propagate in the direction of motion of the softer material at a selected (maximal) velocity and continuously evolve while propagating. In the opposite direction bimaterial coupling favors crack-like ‘supershear' fronts. The robustness of these structures shows the importance of bimaterial coupling to frictional motion and modes of frictional dissipation. PMID:27278687

  6. Viscous Moment, Mechanism of Slow Slip, and Subduction Megathrust Viscosity

    NASA Astrophysics Data System (ADS)

    Fagereng, A.

    2015-12-01

    Slow slip events (SSEs) represent transient slip velocities slower than earthquakes but faster than steady, average plate motion. SSEs repeating at the same location have characteristic slip magnitude and duration. Contrary to earthquakes, however, average slip relates to neither duration nor area. Variations in duration, slip, and slip rate can instead be tied to variations in effective viscosity, calculated from a viscous definition of moment. In this paradigm, the observation that deep slow slip events are slower and longer, implies a higher effective viscosity than in shallower, colder SSEs. Observed variations in effective viscosity and slip rate can be interpreted in terms of differences in driving stress and shear zone width, and likely arise in anastomosing shear zones containing a heterogeneous mixture of materials.

  7. Development of compact slip detection sensor using dielectric elastomer

    NASA Astrophysics Data System (ADS)

    Choi, Jae-young; Hwang, Do-Yeon; Kim, Baek-chul; Moon, Hyungpil; Choi, Hyouk Ryeol; Koo, Ja Choon

    2015-04-01

    In this paper, we developed a resistance tactile sensor that can detect a slip on the surface of sensor structure. The presented sensor device has fingerprint-like structures that are similar with the role of the humans finger print. The resistance slip sensor that the novel developed uses acrylo-nitrile butadiene rubber (NBR) as a dielectric substrate and graphene as an electrode material. We can measure the slip as the structure of sensor makes a deformation and it changes the resistance through forming a new conductive route. To manufacture our sensor, we developed a new imprint process. By using this process, we can produce sensor with micro unit structure. To verify effectiveness of the proposed slip detection, experiment using prototype of resistance slip sensor is conducted with an algorithm to detect slip and slip is successfully detected. We will discuss the slip detection properties.

  8. Distributed Slip Model for Simulating Virtual Earthquakes

    NASA Astrophysics Data System (ADS)

    Shani-Kadmiel, S.; Tsesarsky, M.; Gvirtzman, Z.

    2014-12-01

    We develop a physics based, generic finite fault source, which we call the Distributed Slip Model (DSM) for simulating large virtual earthquakes. This task is a necessary step towards ground motion prediction in earthquake-prone areas with limited instrumental coverage. A reliable ground motion prediction based on virtual earthquakes must account for site, path, and source effects. Assessment of site effect mainly depends on near-surface material properties which are relatively well constrained, using geotechnical site data and borehole measurements. Assessment of path effect depends on the deeper geological structure, which is also typically known to an acceptable resolution. Contrarily to these two effects, which remain constant for a given area of interest, the earthquake rupture process and geometry varies from one earthquake to the other. In this study we focus on a finite fault source representation which is both generic and physics-based, for simulating large earthquakes where limited knowledge is available. Thirteen geometric and kinematic parameters are used to describe the smooth "pseudo-Gaussian" slip distribution, such that slip decays from a point of peak slip within an elliptical rupture patch to zero at the borders of the patch. Radiation pattern and spectral charectaristics of our DSM are compared to those of commonly used finite fault models, i.e., the classical Haskell's Model (HM) and the modified HM with Radial Rupture Propagation (HM-RRP) and the Point Source Model (PSM). Ground motion prediction based on our DSM benefits from the symmetry of the PSM and the directivity of the HM while overcoming inadequacy for modeling large earthquakes of the former and the non-physical uniform slip of the latter.

  9. Deformation patters above intrusive complexes in strike-slip settings

    NASA Astrophysics Data System (ADS)

    Girard, G.; van Wyk de Vries, B.

    2003-04-01

    Long-lived intrusions below volcanic complexes are weak, ductile zones in the crust. In volcanic areas with strike-slip deformation pull-apart complexes are often associated with volcanoes, especially calderas. The Masaya-Las Sierras volcano in Nicaragua is a basaltic caldera complex situated in a developing pull-apart (Managua Graben). The pull-apart faults are responsible for highly damaging earthquakes (Managua 1931, 68, 72). We raise the hypothesis that pull-apart and caldera intrusive system are interrelated and that joint surveillance of faults and volcano could provide the best monitoring strategy. To test relationships between intrusive complex and tectonics we have run a series of ‘sand-box’ analogue models. Displacement is created by a motor on a basal discontinuity and computer-controlled. The models have a lower ductile crust (silicone layer), an upper brittle crust (sand and plaster), and an intrusion made of silicone or varying density and viscosity. Experiments show that a pull apart always forms around a ductile intrusion, irrespective of its density, however that a non-ductile intrusive complex has no significant influence. Whatever the shape of the intrusion, the fault pattern forms a typical rhombohedral pull-apart shape. Fault patterns spaying out from the models resemble closely the Managua fault pattern. With large displacements two zones of thrusting were observed in the system. Such deformation is not present at Masaya, but may be at other calderas with more active strike-slip activity. We provide one possible example in the Atacama, N Chile.

  10. Downscaling of slip distribution for strong earthquakes

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Oya, S.; Kuzuha, Y.

    2013-12-01

    We intend to develop a downscaling model to enhance the earthquake slip distribution resolution. Slip distributions have been obtained by other researchers using various inversion methods. As a downscaling model, we are discussing fractal models that include mono-fractal models (fractional Brownian motion, fBm; fractional Lévy motion, fLm) and multi-fractal models as candidates. Log - log-linearity of k (wave number) versus E (k) (power spectrum) is the necessary condition for fractality: the slip distribution is expected to satisfy log - log-linearity described above if we can apply fractal model to a slip distribution as a downscaling model. Therefore, we conducted spectrum analyses using slip distributions of 11 earthquakes as explained below. 1) Spectrum analyses using one-dimensional slip distributions (strike direction) were conducted. 2) Averaging of some results of power spectrum (dip direction) was conducted. Results show that, from the viewpoint of log - log-linearity, applying a fractal model to slip distributions can be inferred as valid. We adopt the filtering method after Lavallée (2008) to generate fBm/ fLm. In that method, generated white noises (random numbers) are filtered using a power law type filter (log - log-linearity of the spectrum). Lavallée (2008) described that Lévy white noise that generates fLm is more appropriate than the Gaussian white noise which generates fBm. In addition, if the 'alpha' parameter of the Lévy law, which governs the degree of attenuation of tails of the probability distribution, is 2.0, then the Lévy distribution is equivalent to the Gauss distribution. We analyzed slip distributions of 11 earthquakes: the Tohoku earthquake (Wei et al., 2011), Haiti earthquake (Sladen, 2010), Simeulue earthquake (Sladen, 2008), eastern Sichuan earthquake (Sladen, 2008), Peru earthquake (Konca, 2007), Tocopilla earthquake (Sladen, 2007), Kuril earthquake (Sladen, 2007), Benkulu earthquake (Konca, 2007), and southern Java

  11. Effects of slip, slip rate, and shear heating on the friction of granite

    USGS Publications Warehouse

    Blanpied, M.L.; Tullis, T.E.; Weeks, J.D.

    1998-01-01

    The stability of fault slip is sensitive to the way in which frictional strength responds to changes in slip rate and in particular to the effective velocity dependence of steady state friction ????ss/?? ln V. This quantity can vary substantially with displacement, temperature and slip rate. To investigate the physical basis for this behavior and the possible influence of shear heating, we slid initially bare granite surfaces in unconfined rotary shear to displacements of hundreds of millimeters at normal stresses, ??n, of 10 and 25 MPa and at room temperature. We imposed step changes in slip rate within the range 10-2 to 103.5 ??m/s and also monitored frictional heating with thermistors embedded in the granite. The transient response of ?? to slip rate steps was fit to a rate- and state-dependent friction law using two state variables to estimate the values of several parameters in the constitutive law. The first 20 mm of slip shows rising friction and falling ????ss/?? ln V; further slip shows roughly constant friction, ????ss/?? ln V and parameter values, suggesting that a steady state condition is reached on the fault surface. At V ??? 10 ??m/s, ????ss/?? ln V = -0.004 ?? 0.001. At higher rates the response is sensitive to normal stress: At ??n = 25 MPa granite shows a transition to effective velocity strengthening (????ss/?? ln V = 0.008 ?? 0.004) at the highest slip rates tested. At 10 MPa granite shows a less dramatic change to ????ss/?? ln V ??? 0 at the highest rates. The maximum temperature measured in the granite is ???60??C at 25 MPa and 103.5 ??m/s. Temperatures are in general agreement with a numerical model of heat conduction which assumes spatially homogeneous frictional heating over the sliding surface. The simplest interpretation of our measurements of ????ss/?? ln V is that the granite is inherently veocity weakening (?????ss/??? In V 0 mimics velocity strengthening. These results have implications for the frictional behavior of faults during

  12. What do formal inversions of space geodetic data tell us about fault slip rates? Examples from Southern California. (Invited)

    NASA Astrophysics Data System (ADS)

    Lindsey, E. O.; Fialko, Y.

    2010-12-01

    We use secular velocities from the continuous GPS data provided by the Plate Boundary Observatory (PBO) and Scripps Orbit Permanent Array Center (SOPAC), campaign GPS data (SCEC Crustal Motion Model) and InSAR data from the ERS-1/2 and ENVISAT satellites spanning nearly 20 years (1992-2010) to estimate the contemporaneous slip rates and locking depths on the Southern San Andreas fault (SAF), the San Jacinto fault (SJF) and the Elsinore fault. The model parameter space was interrogated using a Gibbs sampler, a Markov chain Monte Carlo algorithm which naturally approximates the joint probability distribution for the model parameters and allows for a formal evaluation of model uncertainties and trade-offs. We performed joint inversions of all available space geodetic data using the Savage and Burford (1973) dislocation model. Previous geodetic estimates of slip rates in this region based on dislocation models have generally inferred a higher slip velocity on the SAF (21-26 mm/yr), and a lower velocity on the SJF (12-19 mm/yr) (Becker et al. 2005, Fay and Humphreys 2005, Meade and Hager 2005, Fialko 2006). These "geodetic" slip rates are generally higher than geologic estimates representing average slip rates on time scales of 10^4-10^6 years. We investigate implications of fault geometry such as a non-vertical SAF and a "blind" segment of the SJF (Fialko 2006; Lin et al. 2007). Using the fault geometry motivated by these recent studies, we estimate a slip rate of 16(+/-2) mm/yr for the southern SAF, and a combined slip rate of 21(+/-3) mm/yr for the two closely spaced branches of the southern San Jacinto fault (the Coyote Creek fault and the blind southern continuation of the Clark fault). The locking depths are estimated at 7(+/-3) km and 14(+/-6) km for the SAF and SJF, respectively. For the SJF, we note a significant trade-off between fault velocity and locking depth, with the best-fitting values occurring at the lower end of the formally estimated parameter ranges

  13. Phase Slips in Oscillatory Hair Bundles

    PubMed Central

    Roongthumskul, Yuttana; Shlomovitz, Roie; Bruinsma, Robijn; Bozovic, Dolores

    2013-01-01

    Hair cells of the inner ear contain an active amplifier that allows them to detect extremely weak signals. As one of the manifestations of an active process, spontaneous oscillations arise in fluid immersed hair bundles of in vitro preparations of selected auditory and vestibular organs. We measure the phase-locking dynamics of oscillatory bundles exposed to low-amplitude sinusoidal signals, a transition that can be described by a saddle-node bifurcation on an invariant circle. The transition is characterized by the occurrence of phase slips, at a rate that is dependent on the amplitude and detuning of the applied drive. The resultant staircase structure in the phase of the oscillation can be described by the stochastic Adler equation, which reproduces the statistics of phase slip production. PMID:25167040

  14. Phase slips in oscillatory hair bundles.

    PubMed

    Roongthumskul, Yuttana; Shlomovitz, Roie; Bruinsma, Robijn; Bozovic, Dolores

    2013-04-01

    Hair cells of the inner ear contain an active amplifier that allows them to detect extremely weak signals. As one of the manifestations of an active process, spontaneous oscillations arise in fluid immersed hair bundles of in vitro preparations of selected auditory and vestibular organs. We measure the phase-locking dynamics of oscillatory bundles exposed to low-amplitude sinusoidal signals, a transition that can be described by a saddle-node bifurcation on an invariant circle. The transition is characterized by the occurrence of phase slips, at a rate that is dependent on the amplitude and detuning of the applied drive. The resultant staircase structure in the phase of the oscillation can be described by the stochastic Adler equation, which reproduces the statistics of phase slip production. PMID:25167040

  15. Phase Slips in Oscillatory Hair Bundles

    NASA Astrophysics Data System (ADS)

    Roongthumskul, Yuttana; Shlomovitz, Roie; Bruinsma, Robijn; Bozovic, Dolores

    2013-04-01

    Hair cells of the inner ear contain an active amplifier that allows them to detect extremely weak signals. As one of the manifestations of an active process, spontaneous oscillations arise in fluid immersed hair bundles of in vitro preparations of selected auditory and vestibular organs. We measure the phase-locking dynamics of oscillatory bundles exposed to low-amplitude sinusoidal signals, a transition that can be described by a saddle-node bifurcation on an invariant circle. The transition is characterized by the occurrence of phase slips, at a rate that is dependent on the amplitude and detuning of the applied drive. The resultant staircase structure in the phase of the oscillation can be described by the stochastic Adler equation, which reproduces the statistics of phase slip production.

  16. Surface slip during large Owens Valley earthquakes

    NASA Astrophysics Data System (ADS)

    Haddon, E. K.; Amos, C. B.; Zielke, O.; Jayko, A. S.; Bürgmann, R.

    2016-06-01

    The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from ˜1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ˜0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ˜6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ˜7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ˜0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

  17. Slip-trace-induced vicinal step destabilization

    NASA Astrophysics Data System (ADS)

    Coupeau, C.; Camara, O.; Drouet, M.; Durinck, J.; Bonneville, J.; Colin, J.; Grilhé, J.

    2016-01-01

    Gold single crystals were deformed by uniaxial compression tests with the help of an experimental apparatus that allows one to characterize in situ, by UHV scanning tunneling microscopy, the evolution of surface structures under stress. It is demonstrated that the slip traces resulting from the emergence of moving dislocations at the free surface highly modify the organization of the vicinal steps. A model based on energetic considerations is proposed and discussed to explain the observed phenomenon.

  18. IMPROVED MAGNESIUM OXIDE SLIP CASTING METHOD

    DOEpatents

    Stoddard, S.D.; Nuckolls, D.E.

    1963-12-31

    A process for making an aqueous magnesium oxide slip casting slurry comprising the steps of mixing finely ground fused magnesium oxide with water, milling the slurry for at least 30 hours at a temperature of 2-10 deg C (the low temperature during milling inhibiting the formation of hydrated magnesium oxide), discharging the slurry from the mill, adding hydrochloric acid as a deflocculent, and adding a scum inhibitor is presented. (AEC)

  19. Dynamics and wheel's slip ratio of a wheel-legged robot in wheeled motion considering the change of height

    NASA Astrophysics Data System (ADS)

    Ding, Xilun; Li, Kejia; Xu, Kun

    2012-09-01

    The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS-II. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS-II in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified. Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.

  20. Slip length crossover on a graphene surface

    SciTech Connect

    Liang, Zhi; Keblinski, Pawel

    2015-04-07

    Using equilibrium and non-equilibrium molecular dynamics simulations, we study the flow of argon fluid above the critical temperature in a planar nanochannel delimited by graphene walls. We observe that, as a function of pressure, the slip length first decreases due to the decreasing mean free path of gas molecules, reaches the minimum value when the pressure is close to the critical pressure, and then increases with further increase in pressure. We demonstrate that the slip length increase at high pressures is due to the fact that the viscosity of fluid increases much faster with pressure than the friction coefficient between the fluid and the graphene. This behavior is clearly exhibited in the case of graphene due to a very smooth potential landscape originating from a very high atomic density of graphene planes. By contrast, on surfaces with lower atomic density, such as an (100) Au surface, the slip length for high fluid pressures is essentially zero, regardless of the nature of interaction between fluid and the solid wall.

  1. Earthquake slip on oceanic transform faults.

    PubMed

    Abercrombie, R E; Ekström, G

    2001-03-01

    Oceanic transform faults are one of the main types of plate boundary, but the manner in which they slip remains poorly understood. Early studies suggested that relatively slow earthquake rupture might be common; moreover, it has been reported that very slow slip precedes some oceanic transform earthquakes, including the 1994 Romanche earthquake. The presence of such detectable precursors would have obvious implications for earthquake prediction. Here we model broadband seismograms of body waves to obtain well-resolved depths and rupture mechanisms for 14 earthquakes on the Romanche and Chain transform faults in the equatorial Atlantic Ocean. We found that earthquakes on the longer Romanche transform are systematically deeper than those on the neighbouring Chain transform. These depths indicate that the maximum depth of brittle failure is at a temperature of approximately 600 degrees C in oceanic lithosphere. We find that the body waves from the Romanche 1994 earthquake can be well modelled with relatively deep slip on a single fault, and we use the mechanism and depth of this earthquake to recalculate its source spectrum. The previously reported slow precursor can be explained as an artefact of uncertainties in the assumed model parameters. PMID:11242043

  2. Earthquake slip on oceanic transform faults.

    PubMed

    Abercrombie, R E; Ekström, G

    2001-03-01

    Oceanic transform faults are one of the main types of plate boundary, but the manner in which they slip remains poorly understood. Early studies suggested that relatively slow earthquake rupture might be common; moreover, it has been reported that very slow slip precedes some oceanic transform earthquakes, including the 1994 Romanche earthquake. The presence of such detectable precursors would have obvious implications for earthquake prediction. Here we model broadband seismograms of body waves to obtain well-resolved depths and rupture mechanisms for 14 earthquakes on the Romanche and Chain transform faults in the equatorial Atlantic Ocean. We found that earthquakes on the longer Romanche transform are systematically deeper than those on the neighbouring Chain transform. These depths indicate that the maximum depth of brittle failure is at a temperature of approximately 600 degrees C in oceanic lithosphere. We find that the body waves from the Romanche 1994 earthquake can be well modelled with relatively deep slip on a single fault, and we use the mechanism and depth of this earthquake to recalculate its source spectrum. The previously reported slow precursor can be explained as an artefact of uncertainties in the assumed model parameters.

  3. Periodic slow slip triggers megathrust zone earthquakes in northeastern Japan.

    PubMed

    Uchida, Naoki; Iinuma, Takeshi; Nadeau, Robert M; Bürgmann, Roland; Hino, Ryota

    2016-01-29

    Both aseismic and seismic slip accommodate relative motion across partially coupled plate-boundary faults. In northeastern Japan, aseismic slip occurs in the form of decelerating afterslip after large interplate earthquakes and as relatively steady slip on uncoupled areas of the subduction thrust. Here we report on a previously unrecognized quasi-periodic slow-slip behavior that is widespread in the megathrust zone. The repeat intervals of the slow slip range from 1 to 6 years and often coincide with or precede clusters of large [magnitude (M) ≥ 5] earthquakes, including the 2011 M 9 Tohoku-oki earthquake. These results suggest that inherently periodic slow-slip events result in periodic stress perturbations and modulate the occurrence time of larger earthquakes. The periodicity in the slow-slip rate has the potential to help refine time-dependent earthquake forecasts.

  4. Pore sizes and filtration rates from two alumina slips

    SciTech Connect

    Smith, P.A. . Materials Science Dept.); Kerch, H.; Krueger, S.; Long, G.G. . Ceramics Div.); Keller, J.; Haber, R.A. . Dept. of Ceramics)

    1994-07-01

    The relationship between filtration rate and the resultant green body microstructure was examined for aqueous alumina slips cast at two different deflocculation states. The volume loading of both slips was 40%. Slip viscosities of 500 and 60 mPa[center dot]s were produced by different tetrasodium pyrophosphate additions. The filtration rate of these slips varied by a factor of 2; however, mercury porosimetry results showed the same average pore size for both samples. Single and multiple small-angle neutron scattering results showed the specimen cast with the higher-viscosity slip to possess a bimodal pore size distribution. The body cast with the low-viscosity slip showed unimodal porosity and, consequently, the filtration is attributed to the toroidal region between the packed particles. These results showed that mercury porosimetry does not provide a pore size that predicts filtration behavior of slips with different degrees of dispersion.

  5. Periodic slow slip triggers megathrust zone earthquakes in northeastern Japan.

    PubMed

    Uchida, Naoki; Iinuma, Takeshi; Nadeau, Robert M; Bürgmann, Roland; Hino, Ryota

    2016-01-29

    Both aseismic and seismic slip accommodate relative motion across partially coupled plate-boundary faults. In northeastern Japan, aseismic slip occurs in the form of decelerating afterslip after large interplate earthquakes and as relatively steady slip on uncoupled areas of the subduction thrust. Here we report on a previously unrecognized quasi-periodic slow-slip behavior that is widespread in the megathrust zone. The repeat intervals of the slow slip range from 1 to 6 years and often coincide with or precede clusters of large [magnitude (M) ≥ 5] earthquakes, including the 2011 M 9 Tohoku-oki earthquake. These results suggest that inherently periodic slow-slip events result in periodic stress perturbations and modulate the occurrence time of larger earthquakes. The periodicity in the slow-slip rate has the potential to help refine time-dependent earthquake forecasts. PMID:26823425

  6. Relationships among certain joint constitutive models.

    SciTech Connect

    Segalman, Daniel Joseph; Starr, Michael James

    2004-09-01

    In a recent paper, Starr and Segalman demonstrated that any Masing model can be represented as a parallel-series Iwan model. A preponderance of the constitutive models that have been suggested for simulating mechanical joints are Masing models, and the purpose of this discussion is to demonstrate how the Iwan representation of those models can yield insight into their character. In particular, this approach can facilitate a critical comparison among numerous plausible constitutive models. It is explicitly shown that three-parameter models such as Smallwood's (Ramberg-Osgood) calculate parameters in such a manner that macro-slip is not an independent parameter, yet the model admits macro-slip. The introduction of a fourth parameter is therefore required. It is shown that when a macro-slip force is specified for the Smallwood model the result is a special case of the Segalman four-parameter model. Both of these models admit a slope discontinuity at the inception of macro-slip. A five-parameter model that has the beneficial features of Segalman's four-parameter model is proposed. This model manifests a force-displacement curve having a continuous first derivative.

  7. Modeling of rock friction 2. Simulation of preseismic slip

    USGS Publications Warehouse

    Dieterich, J.H.

    1979-01-01

    The constitutive relations developed in the companion paper are used to model detailed observations of preseismic slip and the onset of unstable slip in biaxial laboratory experiments. The simulations employ a deterministic plane strain finite element model to represent the interactions both within the sliding blocks and between the blocks and the loading apparatus. Both experiments and simulations show that preseismic slip is controlled by initial inhomogeneity of shear stress along the sliding surface relative to the frictional strength. As a consequence of the inhomogeneity, stable slip begins at a point on the surface and the area of slip slowly expands as the external loading increases. A previously proposed correlation between accelerating rates of stable slip and growth of the area of slip is supported by the simulations. In the simulations and in the experiments, unstable slip occurs shortly after a propagating slip event traverses the sliding surface and breaks out at the ends of the sample. In the model the breakout of stable slip causes a sudden acceleration of slip rates. Because of velocity dependency of the constitutive relationship for friction, the rapid acceleration of slip causes a decrease in frictional strength. Instability occurs when the frictional strength decreases with displacement at a rate that exceeds the intrinsic unloading characteristics of the sample and test machine. A simple slider-spring model that does not consider preseismic slip appears to approximate the transition adequately from stable sliding to unstable slip as a function of normal stress, machine stiffness, and surface roughness for small samples. However, for large samples and for natural faults the simulations suggest that the simple model may be inaccurate because it does not take into account potentially large preseismic displacements that will alter the friction parameters prior to instability. Copyright ?? 1979 by the American Geophysical Union.

  8. Detectability of slow slip beneath the seismogenic zone of strike-slip faults using borehole tiltmeters

    NASA Astrophysics Data System (ADS)

    Chery, J.

    2015-12-01

    During the last decades, geodetic tools like C-GPS allowed the detection of slow slip events associated with transient motion below the seismogenic zone. This new class of fault motion lead us to revise the standard version of the seismic cycle simply including coseismic, postseismic and interseismic phases. Most of these discoveries occurred on subduction margins in various places like Japan, Cascadia, Chile and Indonesia. By contrast, GPS and strainmeters have provided little evidence of slow slip beneath the seismogenic zone of large continental faults like the San Andreas fault or the North Anatolian fault. Because the detectability of such motions is mostly tributary from instrumental precision, we examine the theoretical capability of tiltmeter arrays for detecting horizontal motion of a buried vertical fault. We define the slipping part of the strike-slip fault like a buried rectangular patch submitted to horizontal motion. This motion provides horizontal and vertical surface deformation as a function of both patch geometry (length, width, depth) and motion amplitude. Using a dislocation buried at 15km depth, we compute the maximum motion and tilt as a function of seismic moment. Assuming yields of detectability of 1mm for GPS horizontal motion and 10 nrad for a tiltmeter, we show that small slip events could be better detected using high resolution and stability tiltmeters. We then examine how tiltmeters arrays could be used for such a purpose. In particular, we discuss how to deal with usual problems often plaguing tiltmeters data like instrumental drift, borehole coupling and hydrological strain.

  9. Slip of polydisperse polymers: Molecular weight distribution above and below the plane of slip

    NASA Astrophysics Data System (ADS)

    Sabzevari, Seyed Mostafa; Strandman, Satu; Wood-Adams, Paula Marie

    2015-04-01

    When strong slip occurs during the drag flow of highly entangled polybutadienes (PBD) in a sliding plate rheometer equipped with stainless steel parallel plates, a thin film of polymer debris remains on the substrate after the slip. This debris is assumed to be formed by the disentanglement process that occurs in strong slip at a distance of about one molecular size from the plate. In order to evaluate the composition of the debris we collected it with tetrahydrofuran and subjected it to gel permeation chromatography. It was found that the molecular weight distribution (MWD) of the debris is significantly different from that of the bulk. Moreover, in mixtures prepared from long and short PBDs with distinctly different molecular weight distributions, the MWD of the debris was found to be richer in low molecular weight components and leaner in the high molecular weight components compared to the bulk. This information is important since it reveals the compositional difference between the bulk and interfacial layer above and below the plane of slip. The difference in MWD is likely a consequence of the strong slip in which some of long chains are pulled away from the surface-adsorbed chains by the flow leaving a debris lean in the high molecular weight component.

  10. Detailed history of slip along the Sunda mega-thrust

    NASA Astrophysics Data System (ADS)

    Simão, Nuno; Lindsay, Anthony; Murphy, Shane; McCloskey, John; Bhloscaidh, Mairead Nic; Nalbant, Suleyman

    2013-04-01

    We undertook a reconstruction of more than 200 years of deformation on the Sunda mega-thrust using the history of vertical displacement recorded in the stratigraphy of coral micro-atolls. This reconstruction gave an unprecedented opportunity to understand the distributions of slip on the recent series of great earthquakes and its relationship with coupling. We have seen with the recent earthquakes that, whilst the slip-coupling relationship may be complex and certainly depends on the pre-stress, the greatest slip generally occurs in areas of high coupling. We have also seen that the spatial distributions of the greatest slip reveals tessellation between earthquakes. Using Monte Carlo techniques, we compare ground deformation produced by different fractal slip distributions with micro-atoll coral data to estimate slip distributions for the 1797 and 1833 historical earthquakes. The resulting slip estimations have a more realistic spatial distribution and provide a better fit to the micro-atoll data than previously published solutions. Preliminary results seem to imply that the 1797 and 1833 ruptures reveal a level of complementarity, where the greatest values of slip tessellate with the greatest slip values observed in the two great earthquakes of 2007 and the earthquake of 2010. In addition, the spatial stacking of all slips from all available earthquake slip distributions reveals a strong correlation with the spatial distribution of the coupling. Discrepancies in the spatial slip-coupling correlation, although strongly influenced by the uncertainties of the slip distributions, and with the 1797 and 1833 earthquakes playing a stronger role, can still be used as a way to pin-point possible areas of slip deficit when compared with the spatial distribution of coupling. This seems to imply that correspondence between the slip probability in 1797 and 1833 and present-day earthquakes slip and coupling appears to show the same basic relationship indicating that the broad

  11. Slow Slip Events on a 760 mm Long Granite Sample

    NASA Astrophysics Data System (ADS)

    Mclaskey, G.; Yamashita, F.

    2015-12-01

    We describe slow slip events and dynamic rupture events generated on a newly constructed large-scale biaxial friction apparatus at Cornell University that provide insights into the mechanisms of aseismic and seismic slip. We find that, under nominally similar experimental conditions, the 760 mm long granite sample sometimes slips in dynamic stick-slip events and sometimes relieves accumulated shear stress through slow slip events. To provide insights into this curious behavior and the underlying mechanisms, fault slip and shear stress are each measured at 8 locations along the 760 mm long fault. This allows us to map slow slip fronts and the nucleation and propagation of dynamic fault rupture. The granite sample is also instrumented with an array of piezoelectric sensors that are the laboratory equivalent of a seismic network. When the sample is loaded relatively slowly, at 0.03 MPa/s, slow slip occurs on large sections of the fault and the slow slipping region soon expands to the sample boundary. In this case, stress is released in a slow slip event with peak slip velocities < 2 mm/s. Alternatively, when one end of the sample is loaded rapidly (4 MPa/s), or the sample is allowed to heal in stationary contact for a few minutes, slow slip initiates near the load point and accelerates to slip velocities exceeding 200 mm/s before the slow slipping region expands all the way to the sample boundary. This produces a dynamic slip event (stick-slip). The dynamic slip events radiate seismic waves equivalent to a M = -2.5 earthquake. In contrast, the laboratory-generated slow slip events are predominantly aseismic and produce only bursts of tiny and discrete seismic events (M = -6) reminiscent of swarms of microseismicity. The experiments illustrate how a single fault can slide slowly and aseismically or rapidly and dynamically depending on stress state and loading conditions. We compare the behavior observed on this Cornell apparatus to the behavior of other large

  12. Seismic Moment and Slip Distribution of the 1960 and 2010 Chilean Earthquakes as Inferred from Tsunami Waveforms

    NASA Astrophysics Data System (ADS)

    Satake, K.; Fujii, Y.

    2010-12-01

    The 27 February 2010 Chilean earthquake generated tsunami and caused significant damage on the Chilean coast. The tsunami was recorded at many tide gauge stations around the Pacific Ocean, as well as bottom ocean bottom pressure gauges of DART system. We inverted tsunami waveform data, recorded at 11 tide gauges in Chile and Peru and 4 nearby DART stations, to estimate the slip distribution on the fault. When we assume 36 subfaults (12 along strike by 3 downdip, size of each subfault is 50 km × 50 km), very large slip is located at the most downdip subfaults beneath coast and land. Tsunami waveforms recorded other DART stations also require such deep slips. However, other geodetic and seismic data do not show such deep slips, and tsunami data have limited resolution for such a deep onshore slip. We therefore used coastal uplift and subsidence data at 36 locations reported by Farias et al. (2010). The joint inversion indicates two asperities, one to the north around Constitucion and the other to the south around Arauco peninsula. While the largest slip is still located beneath the coast, the offshore slips generally become larger than the tsunami inversion. The total seismic moment is about 1.8 × 1022 Nm (Mw 8.8), similar to the value estimated from tsunami waveforms only, and the fault length is 450 km. For the 22 May 1960 Chilean earthquake, we first made an inversion of tsunami data, recorded at 12 tide gauge stations mostly in South America. When we assume 27 subfaults (9 along strike by 3 downdip, size of each subfault is 100 km × 50 km), the total seismic moment is 4.6 × 1022 Nm (Mw 9.0). Again, the largest slip is estimated at the deepest subfault beneath land near the epicenter, which would produce large coastal uplift where the coastal subsidence was reported by Plafker and Savage (1970). Poor station coverage of tide gauges may limit the resolution of slip distribution particularly at the southern part of the source area. We therefore made a joint

  13. A STUDY ON HIGH STRENGTH BOLTED JOINT WITH METAL-SPRAYED CONTACT SURFACES

    NASA Astrophysics Data System (ADS)

    Minami, Kuniaki; Saito, Masamichi; Yokoyama, Hideki; Sugimoto, Ichiro; Nojima, Takao; Masunaga, Toshihiko; Nagasaki, Eiji

    Slip coefficient of high-strength bolt friction joints is well known to depend on the condition of contact surfaces. The coefficient is determined as 0.4 in the Specifications for Highway Bridges and the Design Standards for Railway Structures and Commentary (Steel Structures) in Japan, in the condition of roughened contact surfaces with mill scale removed or painted contact surfaces with inorganic zinc rich paint. However, the slip coefficient with metal-sprayed surfaces is not clear. For the joints with metalsprayed surfaces, hot-dip galvanized bolts are applied and such bolts are tightened by turn-of-nut method. However, it is unclear how much axial force is induced into the bolts in the joints with metal-sprayed surfaces. In order to examine slip coefficient of the bolted joints with metal-sprayed contact surfaces slip tests of high strength bolted joints were carried out. On the basis of above examinations, the slip coefficient with metal-sprayed surfaces is proposed in this paper. To clarify the induced axial force of the bolts, bolt-tightening tests were carried out. Considering bolt diameter, bolt length, induced axial forces and their relaxation, nut rotation angles are proposed in relation to different bolt size.

  14. Long-term slip deficit and the forecasting of slip in future earthquakes

    NASA Astrophysics Data System (ADS)

    McCloskey, John; NicBhloscaidh, Mairead; Simao, Nuno

    2014-05-01

    In the last decade a series of devastating earthquakes have between them killed more than three-quarters of a million people. None of the events were formally forecast and have been repeatedly referred to a seismological 'surprises'. Here we argue that while earthquakes within the wide swath of diffuse deformation comprising the Alpine-Himalayan belt pose a set of particularly difficult set of challenges, earthquakes which are driven by high strain-rates at plate boundaries and which have relatively short nominal recurrence times might be forecast if the data exists to perform long-term slip deficit modelling and stress reconstruction. We show that two instrumentally recorded event on the Sumatran margin in 2007 and 2010 occurred in regions of high slip deficit identified by reconstruction of slip in historical earthquakes in 1797 and 1833 under the Mentawai Islands using more than 200 years of geodetic data recorded in the stratigraphy of coral micro-atolls growing there. In the presentation we will describe the data and a new Bayesian-Monte Carlo slip reconstruction technique. The technique is based on the stochastic forward modelling of many slip distributions each using the same set of elastic Green's functions to estimate, by superposition of contributions from each fault cell, the vertical displacement at the coral locations resulting from each simulated event. Every solution, weighted by its goodness of fit to the data, is added to a stack whose final values contain an estimate of the most likely distribution of slip in the historical earthquakes. Further, we estimate the Kullback-Liebler divergence over the fault area providing a non-arbitrary assessment of the spatial distribution of information gain, identifying regions of low- and high- model confidence. We then model the long-term slip deficit on the megathrust assuming a zero of stress immediately after the 1652 Mentawai Islands earthquake. We use the resulting slip deficit field to compute the entire

  15. Earthquake scaling laws for rupture geometry and slip heterogeneity

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  16. Progressive slippage after pinning for slipped capital femoral epiphysis.

    PubMed

    Sanders, James O; Smith, William J; Stanley, Earl A; Bueche, Matthew J; Karol, Lori A; Chambers, Henry G

    2002-01-01

    The authors retrospectively reviewed seven cases of progressive slipped capital femoral epiphysis after screw fixation. All seven patients initially presented with chronic symptoms, and five had an acute exacerbation of symptoms with the appearance of an acute-on-chronic slip. Of the other two, one had obvious motion at the proximal femoral physis and the other had increased symptoms but did not have an obvious acute slip radiographically. All underwent percutaneous screw fixation. In four patients a single screw was placed, and in three patients two screws were placed. No patient became symptom-free after surgery. Slip progression was noted on average 5 months after treatment. Radiographs in all patients revealed an increase in slip severity and loss of screw purchase in the femoral neck while fixation in the proximal femoral epiphysis remained secure. One patient had hypothyroidism and another Cushing disease, both diagnosed after the slipped epiphysis. Slips occurring in children with underlying endocrinopathies, and unstable slips in children with a history of antecedent knee or hip pain (commonly called an acute-on-chronic slip) may be susceptible to screw fixation failure. In such patients, close radiographic follow-up, particularly in the presence of continued symptoms, is required to document slip progression and fixation failure as soon as possible.

  17. Major and minor slip-events in frictional stick-slip

    NASA Astrophysics Data System (ADS)

    Tsekenis, Georgios; Tatar, Demet; Rubinstein, Shmuel; Weitz, David; Aziz, Michael; Spaepen, Frans

    Several universal phenomena characterize friction that are independent of the materials involved such as the logarithmic aging of the static friction coefficient and the logarithmic velocity weakening of the dynamic friction coefficient. We study dry friction between rough surfaces with programmed statistical profiles. By measuring the displacement field at the frictional interface we observe stick-slip behavior which reveals two kinds of slip: major events that tend to grow large and unbounded and minor events that usually stay small and bounded. Research supported by Harvard MRSEC Program under NSF contracts DMR-0820484, DMR-1420570.

  18. Coseismic slip distribution of the 1923 Kanto earthquake, Japan

    USGS Publications Warehouse

    Pollitz, F.F.; Nyst, M.; Nishimura, T.; Thatcher, W.

    2005-01-01

    The slip distribution associated with the 1923 M = 7.9 Kanto, Japan, earthquake is reexamined in light of new data and modeling. We utilize a combination of first-order triangulation, second-order triangulation, and leveling data in order to constrain the coseismic deformation. The second-order triangulation data, which have not been utilized in previous studies of 1923 coseismic deformation, are associated with only slightly smaller errors than the first-order triangulation data and expand the available triangulation data set by about a factor of 10. Interpretation of these data in terms of uniform-slip models in a companion study by Nyst et al. shows that a model involving uniform coseismic slip on two distinct rupture planes explains the data very well and matches or exceeds the fit obtained by previous studies, even one which involved distributed slip. Using the geometry of the Nyst et al. two-plane slip model, we perform inversions of the same geodetic data set for distributed slip. Our preferred model of distributed slip on the Philippine Sea plate interface has a moment magnitude of 7.86. We find slip maxima of ???8-9 m beneath Odawara and ???7-8 m beneath the Miura peninsula, with a roughly 2:1 ratio of strike-slip to dip-slip motion, in agreement with a previous study. However, the Miura slip maximum is imaged as a more broadly extended feature in our study, with the high-slip region continuing from the Miura peninsula to the southern Boso peninsula region. The second-order triangulation data provide good evidence for ???3 m right-lateral strike slip on a 35-km-long splay structure occupying the volume between the upper surface of the descending Philippine Sea plate and the southern Boso peninsula. Copyright 2005 by the American Geophysical Union.

  19. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  20. Complicated Recurrence of Slip Events on a Uniform Circular Asperity

    NASA Astrophysics Data System (ADS)

    Kato, N.

    2012-12-01

    Numerical simulation of repeated occurrence of slip events on a fault patch (asperity) is conducted to understand the mechanism of irregularity of the events. Seismic and geodetic observations indicate that episodic seismic/aseismic slip events repeatedly occur at almost the same area. For instance, magnitude of about 4.8 earthquakes had repeatedly occurred at intervals of 4.7 to 6.7 years off Kamaishi, northern Honshu, Japan. Quasi-periodic recurrence of episodic aseismic slip events (slow earthquakes) was found at the Nankai subduction zone, southwestern Japan, the Cascadia subduction zone, North America, etc. The recurrence intervals and magnitudes of slip events in each sequence are not constant, but some variability exists. Some researchers suggested that the variation in aseismic slip rate around a patch of slip events causes variation of loading rate. This results in variation of recurrence intervals. In the present study, we focus on irregularity of recurrence of slip events that originates from dynamics of fault slip. A two-dimensional planar fault in an infinite elastic medium is considered. The fault is uniformly shear loaded at a constant rate, and frictional stress acting on the fault is assumed to obey a rate- and state-dependent friction (RSF) law. A circular patch of radius r with velocity-weakening frictional property is embedded on a fault with velocity-strengthening frictional property elsewhere. A numerical simulation is conducted by varying the characteristic slip distance L of the RSF law. The critical radius rc for occurrence of unstable slip can be defined, and rc is proportional to L. When r >> rc, seismic slip events (earthquakes) repeatedly occur at a constant time interval. When r is a little larger than rc, recurrence of slip events becomes complex. We observe a period-2 cycle of slip events, where large and small events alternately occur. The cycle becomes more complex as r approaches rc and finally aperiodic (chaotic) slip pattern

  1. DEM simulation of growth normal fault slip

    NASA Astrophysics Data System (ADS)

    Chu, Sheng-Shin; Lin, Ming-Lang; Nien, Wie-Tung; Chan, Pei-Chen

    2014-05-01

    Slip of the fault can cause deformation of shallower soil layers and lead to the destruction of infrastructures. Shanchiao fault on the west side of the Taipei basin is categorized. The activities of Shanchiao fault will cause the quaternary sediments underneath the Taipei basin to become deformed. This will cause damage to structures, traffic construction, and utility lines within the area. It is determined from data of geological drilling and dating, Shanchiao fault has growth fault. In experiment, a sand box model was built with non-cohesive sand soil to simulate the existence of growth fault in Shanchiao Fault and forecast the effect on scope of shear band development and ground differential deformation. The results of the experiment showed that when a normal fault containing growth fault, at the offset of base rock the shear band will develop upward along with the weak side of shear band of the original topped soil layer, and this shear band will develop to surface much faster than that of single top layer. The offset ratio (basement slip / lower top soil thickness) required is only about 1/3 of that of single cover soil layer. In this research, it is tried to conduct numerical simulation of sand box experiment with a Discrete Element Method program, PFC2D, to simulate the upper covering sand layer shear band development pace and scope of normal growth fault slip. Results of simulation indicated, it is very close to the outcome of sand box experiment. It can be extended to application in water pipeline project design around fault zone in the future. Keywords: Taipei Basin, Shanchiao fault, growth fault, PFC2D

  2. Kalker's algorithm Fastsim solves tangential contact problems with slip-dependent friction and friction anisotropy

    NASA Astrophysics Data System (ADS)

    Piotrowski, J.

    2010-07-01

    This paper presents two extensions of Kalker's algorithm Fastsim of the simplified theory of rolling contact. The first extension is for solving tangential contact problems with the coefficient of friction depending on slip velocity. Two friction laws have been considered: with and without recuperation of the static friction. According to the tribological hypothesis for metallic bodies shear failure, the friction law without recuperation of static friction is more suitable for wheel and rail than the other one. Sample results present local quantities inside the contact area (division to slip and adhesion, traction) as well as global ones (creep forces as functions of creepages and rolling velocity). For the coefficient of friction diminishing with slip, the creep forces decay after reaching the maximum and they depend on the rolling velocity. The second extension is for solving tangential contact problems with friction anisotropy characterised by a convex set of the permissible tangential tractions. The effect of the anisotropy has been shown on examples of rolling without spin and in the presence of pure spin for the elliptical set. The friction anisotropy influences tangential tractions and creep forces. Sample results present local and global quantities. Both extensions have been described with the same language of formulation and they may be merged into one, joint algorithm.

  3. The 2012 Brawley swarm triggered by injection-induced aseismic slip

    NASA Astrophysics Data System (ADS)

    Wei, Shengji; Avouac, Jean-Philippe; Hudnut, Kenneth W.; Donnellan, Andrea; Parker, Jay W.; Graves, Robert W.; Helmberger, Don; Fielding, Eric; Liu, Zhen; Cappa, Frederic; Eneva, Mariana

    2015-07-01

    It has long been known that fluid injection or withdrawal can induce earthquakes, but the underlying mechanisms remain elusive. For example, the 2012 Brawley swarm, which produced two strike-slip shocks with magnitudes larger than 5.3 and surface ruptures in the close vicinity of a geothermal field, started with earthquakes about 5 km deeper than the injection depth (∼1.5 km). This makes the causality between the injection and seismicity unclear. Here, we jointly analyze broadband and strong motion waveforms, UAVSAR, leveling measurements and field observations to reveal the detailed seismic and aseismic faulting behaviors associated with the 2012 Brawley swarm. In particular, path calibration established from smaller events in the swarm allows waveform inversion to be conducted up to 3 Hz to resolve finite rupture process of the Mw 4.7 normal event. Our results show that the 2012 earthquake sequence was preceded by aseismic slip on a shallow normal fault beneath the geothermal field. Aseismic slip initiated in 2010 when injection rate rapidly increased and triggered the following earthquakes subsequently, including unusually shallow and relatively high frequency seismic excitations on the normal fault. In this example, seismicity is induced indirectly by fluid injection, a result of mediation by aseismic creep, rather than directly by a pore pressure increase at the location of the earthquakes.

  4. Shearing along faults and stratigraphic joints controlled by land subsidence in the Valley of Queretaro, Mexico

    NASA Astrophysics Data System (ADS)

    Carreón-Freyre, D.; Cerca, M.; Ochoa-González, G.; Teatini, P.; Zuñiga, F. R.

    2016-05-01

    Slip of nearly vertical faults or horizontal stratigraphic joints has provoked the shearing of at least 16 well casings in a period of over 10 years in the Valley of Queretaro aquifer, Mexico. Evidence integrated from field observations, remote surface-deformation monitoring, in-situ monitoring, stratigraphic correlation, and numerical modeling indicate that groundwater depletion and land subsidence induce shearing. Two main factors conditioning the stress distribution and the location of sheared well casings have been identified: (1) slip on fault planes, and (2) slip on stratigraphic joints. Additionally, the distribution of piezometric gradients may be a factor that enhances shearing. Slip on faults can be generated either by the compaction of sedimentary units (passive faulting) or by slip of blocks delimited by pre-existing faults (reactivation). Major piezometric-level declines and the distribution of hydraulic gradients can also be associated with slip at stratigraphic joints. Faults and hydraulic contrasts in the heterogeneous rock sequence, along with groundwater extraction, influence the distribution of the gradients and delimit the compartments of groundwater in the aquifer. Analogue modeling allowed assessment of the distribution of stress-strain and displacements associated with the increase of the vertical stress. Fault-bounded aquifers in grabens are common in the central part of Mexico and the results obtained can be applied to other subsiding, structurally controlled aquifer systems elsewhere.

  5. Episodic Tremor and Slip: Cycles Within Cycles

    NASA Astrophysics Data System (ADS)

    Creager, K. C.; Wech, A.; Vidale, J. E.

    2009-12-01

    Episodic tremor and slip (ETS) events, each with geodetically determined moment magnitudes in the mid-6 range, repeat about every 15 months under the Olympic Peninsula/southern Vancouver Island region. We have automatically searched for non-volcanic tremor in all 5-minute time windows both during the past five ETS events and during the two inter-ETS periods from February, 2007 through April, 2008 and June 2008 through April 2009. Inter-ETS tremor was detected in 5000 windows, which overlap by 50%, so tremor was seen 2% of the time. The catalog of 5-minute tremor locations cluster in time and space into groups we call tremor swarms, revealing 50 inter-ETS tremor swarms. The number of hours of tremor per swarm ranged from about 1 to 68, totaling 374 hours. The inter-ETS tremor swarms generally locate along the downdip side of the major ETS events, and account for approximately 45% of the time that tremor has been detected during the last two entire ETS cycles. Many of the inter-ETS events are near-carbon copies in duration, spatial extent and propagation direction, as is seen for the larger 15-month-interval events. These 50 inter-ETS swarms plus two major ETS episodes follow a power law relationship such that the number of swarms, N, exceeding duration τ is given by N ˜ τ-0.7. If we assume that seismic moment is proportional to τ as proposed by Ide et al. [Nature, 2007], we find that the tremor swarms follow a standard Gutenberg-Richter logarithmic frequency-magnitude relation, N ˜ 10-bMw, with b = 1.0, which lies in the range for normal earthquake catalogs. Furthermore, the major ETS events fall on the curve defined by the inter-ETS swarms, suggesting that the inter-ETS swarms are just smaller versions of the major 15-month ETS events. Only the largest events coincide with geodetically observed slip, suggesting that current geodetic observations may be missing nearly half of the total slip. Finally, crude estimates of the spatial dimensions of tremor swarms L

  6. Fixed recurrence and slip models better predict earthquake behavior than the time- and slip-predictable models 1: repeating earthquakes

    USGS Publications Warehouse

    Rubinstein, Justin L.; Ellsworth, William L.; Chen, Kate Huihsuan; Uchida, Naoki

    2012-01-01

    The behavior of individual events in repeating earthquake sequences in California, Taiwan and Japan is better predicted by a model with fixed inter-event time or fixed slip than it is by the time- and slip-predictable models for earthquake occurrence. Given that repeating earthquakes are highly regular in both inter-event time and seismic moment, the time- and slip-predictable models seem ideally suited to explain their behavior. Taken together with evidence from the companion manuscript that shows similar results for laboratory experiments we conclude that the short-term predictions of the time- and slip-predictable models should be rejected in favor of earthquake models that assume either fixed slip or fixed recurrence interval. This implies that the elastic rebound model underlying the time- and slip-predictable models offers no additional value in describing earthquake behavior in an event-to-event sense, but its value in a long-term sense cannot be determined. These models likely fail because they rely on assumptions that oversimplify the earthquake cycle. We note that the time and slip of these events is predicted quite well by fixed slip and fixed recurrence models, so in some sense they are time- and slip-predictable. While fixed recurrence and slip models better predict repeating earthquake behavior than the time- and slip-predictable models, we observe a correlation between slip and the preceding recurrence time for many repeating earthquake sequences in Parkfield, California. This correlation is not found in other regions, and the sequences with the correlative slip-predictable behavior are not distinguishable from nearby earthquake sequences that do not exhibit this behavior.

  7. A diary study of action slips in healthy individuals.

    PubMed

    Jónsdóttir, María K; Adólfsdóttir, Steinunn; Cortez, Rúna Dögg; Gunnarsdóttir, María; Gústafsdóttir, Agústa Hlín

    2007-12-01

    Memory complaints following minor head injury or whiplash are common and often bear similarity to absent mindedness or action slips (Reason, 1979). We replicated Reason's study by asking 189 healthy volunteers to keep diaries of their action slips for a week. The mean number of slips was 6.4 (SD = 4.9). Perceived stress did not correlate with number of slips but there was a weak positive correlation between action slips and scores on a memory failures questionnaire. Memory diaries may be clinically useful when assessing individuals who worry about cognitive sequelae of minor injuries. Diaries clarify the nature of the complaints and may have therapeutic value by demonstrating that the memory slips are less frequent than estimated by the patients. PMID:17853144

  8. Slip statistics of dislocation avalanches under different loading modes

    NASA Astrophysics Data System (ADS)

    Maaß, R.; Wraith, M.; Uhl, J. T.; Greer, J. R.; Dahmen, K. A.

    2015-04-01

    Slowly compressed microcrystals deform via intermittent slip events, observed as displacement jumps or stress drops. Experiments often use one of two loading modes: an increasing applied stress (stress driven, soft), or a constant strain rate (strain driven, hard). In this work we experimentally test the influence of the deformation loading conditions on the scaling behavior of slip events. It is found that these common deformation modes strongly affect time series properties, but not the scaling behavior of the slip statistics when analyzed with a mean-field model. With increasing plastic strain, the slip events are found to be smaller and more frequent when strain driven, and the slip-size distributions obtained for both drives collapse onto the same scaling function with the same exponents. The experimental results agree with the predictions of the used mean-field model, linking the slip behavior under different loading modes.

  9. Cascadia tremor polarization evidence for plate interface slip

    NASA Astrophysics Data System (ADS)

    Wech, Aaron G.; Creager, Kenneth C.

    2007-11-01

    New seismic measurements of the repeated phenomenon of Episodic Tremor and Slip in northern Cascadia indicate identical source processes of tremor and slow slip. Predicted polarization directions of upgoing S-waves radiated from shear slip on the plate interface align with the relative motion between the Juan de Fuca and North American plates. Seismic observations from small-aperture array data on the Olympic Peninsula of the Cascadia subduction zone show uncharacteristically stable linear particle motion coincident with the passage of tremor sources beneath the array. The azimuth of this horizontal ground motion matches expected polarizations from slip on the plate interface. This finding suggests that Cascadia tremor is shear slip on the plate interface, implying that, as in Japan, geodetically observed slow slip and seismically observed tremor are manifestations of the same phenomenon.

  10. Slip statistics of dislocation avalanches under different loading modes.

    PubMed

    Maass, R; Wraith, M; Uhl, J T; Greer, J R; Dahmen, K A

    2015-04-01

    Slowly compressed microcrystals deform via intermittent slip events, observed as displacement jumps or stress drops. Experiments often use one of two loading modes: an increasing applied stress (stress driven, soft), or a constant strain rate (strain driven, hard). In this work we experimentally test the influence of the deformation loading conditions on the scaling behavior of slip events. It is found that these common deformation modes strongly affect time series properties, but not the scaling behavior of the slip statistics when analyzed with a mean-field model. With increasing plastic strain, the slip events are found to be smaller and more frequent when strain driven, and the slip-size distributions obtained for both drives collapse onto the same scaling function with the same exponents. The experimental results agree with the predictions of the used mean-field model, linking the slip behavior under different loading modes.

  11. Slip statistics of dislocation avalanches under different loading modes.

    PubMed

    Maass, R; Wraith, M; Uhl, J T; Greer, J R; Dahmen, K A

    2015-04-01

    Slowly compressed microcrystals deform via intermittent slip events, observed as displacement jumps or stress drops. Experiments often use one of two loading modes: an increasing applied stress (stress driven, soft), or a constant strain rate (strain driven, hard). In this work we experimentally test the influence of the deformation loading conditions on the scaling behavior of slip events. It is found that these common deformation modes strongly affect time series properties, but not the scaling behavior of the slip statistics when analyzed with a mean-field model. With increasing plastic strain, the slip events are found to be smaller and more frequent when strain driven, and the slip-size distributions obtained for both drives collapse onto the same scaling function with the same exponents. The experimental results agree with the predictions of the used mean-field model, linking the slip behavior under different loading modes. PMID:25974504

  12. EMG and Kinematic Responses to Unexpected Slips After Slip Training in Virtual Reality

    PubMed Central

    Parijat, Prakriti; Lockhart, Thurmon E.

    2015-01-01

    The objective of the study was to design a virtual reality (VR) training to induce perturbation in older adults similar to a slip and examine the effect of the training on kinematic and muscular responses in older adults. Twenty-four older adults were involved in a laboratory study and randomly assigned to two groups (virtual reality training and control). Both groups went through three sessions including baseline slip, training, and transfer of training on slippery surface. The training group experienced twelve simulated slips using a visual perturbation induced by tilting a virtual reality scene while walking on the treadmill and the control group completed normal walking during the training session. Kinematic, kinetic, and EMG data were collected during all the sessions. Results demonstrated the proactive adjustments such as increased trunk flexion at heel contact after training. Reactive adjustments included reduced time to peak activations of knee flexors, reduced knee coactivation, reduced time to trunk flexion, and reduced trunk angular velocity after training. In conclusion, the study findings indicate that the VR training was able to generate a perturbation in older adults that evoked recovery reactions and such motor skill can be transferred to the actual slip trials. PMID:25296401

  13. An Inexpensive Device for Modelling Strike-Slip and Oblique-Slip Fault Zones.

    ERIC Educational Resources Information Center

    Larter, Richard C. L.; Allison, Iain

    1983-01-01

    Describes construction/use of a device to simulate structures produced in fault zones of dominantly strike-dip motion. Apparatus modifications allow simulation of transtension and transpression as well as pure strike-slip fault motion. Illustrates formation of several structures using the apparatus, comparing them with natural examples. Includes…

  14. Tsunami Modeling to Validate Slip Models of the 2007 M w 8.0 Pisco Earthquake, Central Peru

    NASA Astrophysics Data System (ADS)

    Ioualalen, M.; Perfettini, H.; Condo, S. Yauri; Jimenez, C.; Tavera, H.

    2013-03-01

    Following the 2007, August 15th, M w 8.0, Pisco earthquake in central Peru, Sladen et al. (J Geophys Res 115: B02405, 2010) have derived several slip models of this event. They inverted teleseismic data together with geodetic (InSAR) measurements to look for the co-seismic slip distribution on the fault plane, considering those data sets separately or jointly. But how close to the real slip distribution are those inverted slip models? To answer this crucial question, the authors generated some tsunami records based on their slip models and compared them to DART buoys, tsunami records, and available runup data. Such an approach requires a robust and accurate tsunami model (non-linear, dispersive, accurate bathymetry and topography, etc.) otherwise the differences between the data and the model may be attributed to the slip models themselves, though they arise from an incomplete tsunami simulation. The accuracy of a numerical tsunami simulation strongly depends, among others, on two important constraints: (i) A fine computational grid (and thus the bathymetry and topography data sets used) which is not always available, unfortunately, and (ii) a realistic tsunami propagation model including dispersion. Here, we extend Sladen's work using newly available data, namely a tide gauge record at Callao (Lima harbor) and the Chilean DART buoy record, while considering a complete set of runup data along with a more realistic tsunami numerical that accounts for dispersion, and also considering a fine-resolution computational grid, which is essential. Through these accurate numerical simulations we infer that the InSAR-based model is in better agreement with the tsunami data, studying the case of the Pisco earthquake indicating that geodetic data seems essential to recover the final co-seismic slip distribution on the rupture plane. Slip models based on teleseismic data are unable to describe the observed tsunami, suggesting that a significant amount of co-seismic slip may have

  15. Subduction zone structures and slip behavior in megathrust

    NASA Astrophysics Data System (ADS)

    Kodaira, S.; Nakanishi, A.; Nakamura, Y.

    2014-12-01

    Earthquake, tsunami and geodetic data show that co-seismic slips of a large megathrust earthquakes do not uniformly propagate along a plate boundary. For example, a clear segmentation of slip zones of magnitude-8 class megathrust earthquakes are well recognized in the Nankai Trough. Moreover, a lateral variation of the slips are revealed even in one segment. In the Japan Trench, the most characteristic slip behavior of the 2011 Tohoku-oki earthquake is an extremely large slip reaching to the trench axis, but geodetic, tsunami or teleseismic show the slip was heterogeneous near the trench. In order to examine whether those complex slip distributions are attributed by any distinct structural factor, we have been carried out active-source seismic surveys in the subduction seismogenic. In the Nankai Trough, large-scale subducted seamounts, ridges and doming structure intruded in an overriding accretion wedge are imaged. Comparing co-seismic slip distribution of the 1944 Tonankai and the 1946 Nankai earthquakes with the seismic images, we concluded that those structures are key factors to control the slip distributions. In the central part of the Japan Trench area, we fund a rough basement geometry is overprinted on the horst-and-graben structure. Those complex geometry of basement cause a strong lateral variation of the thickness of subducting pelagic/hemi-pelagic sediment. Many geological studies suggest that properties of the plate-boundary sediment attribute the large slip near the trench. We therefore plan to acquire additional high-resolution seismic data in the entire Japan Trench in order to examine a role of incoming sediment on the large slip to the trench axis. In this presentation we present an overview of the structural factors controlling slips in megathrust earthquakes, including new data acquired in the Nankai Trough and Japan Trench.

  16. Earthquake-Like Slip Events on a Laboratory Fault

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Reches, Z.; Lockner, D. A.; Totten, M. W., Jr.

    2009-12-01

    We generated dynamic slip events with prescribed total energy on an experimental fault. Sliding occurred between granite rings, in a rotary shear apparatus driven by a 100 hp motor and a massive flywheel (225 kg) at normal stress up to 7 MPa (Lockner and Reches, this meeting). In the experiments, the motor first brought the flywheel to a pre-selected angular velocity. Then, the motor was disengaged and the flywheel was connected to one granite block through a fast-acting clutch, initiating slip between the rotating and stationary blocks. The rate- and slip- dependent friction of the simulated fault surface controlled the slip velocity and slip distance until the kinetic energy of the flywheel was consumed. The flywheel kinetic energy density (per unit area of the sliding surfaces) ranges from 75 J/m2, which is insufficient to initiate slip, to 3.6 106 J/m2, which generates slip events with duration of ~2 s, maximum slip velocity 0.6-0.7 m/s, and slip distance 0.6-0.9 m. The main observations are: (1) Rise-time < 0.1s for all events; (2) Fault locked until the shear stress reaches yield stress (sliding friction of 0.65-0.8); (3) Modest drop (5-15%) of shear strength during sliding at slip velocities less than 0.25 m/s. (4) Significant weakening at slip velocity greater than 0.25 m/s, and this weakening is associated with the onset of ‘chattering slip’ (= continuous high-frequency stick-slip events); (5) power law relations between total sliding distance and flywheel energy. The research was supported by NSF grant # 0732715.

  17. [Slipped capital femoral epiphysis associated with hyperparathyroidism. A case report].

    PubMed

    Khiari, Karima; Cherif, Lotfi; Ben Abdallah, Nejib; Maazoun, Imen; Hadj Ali, Insaf; Bentaarit, Chokri; Turki, Sami; Ben Maïz, Hedi

    2003-12-01

    Slippage of the upper femoral epiphysis can occur in association with multiple endocrine imbalances. A case of slipped femoral epiphysis with primary hyperparathyroidism is reported. The patient was an adolescent, 16 Years of age, who presented bilateral slipped epiphysis. Investigation showed that he had hypercalcemia (3.1 mmol/l) related to primary hyperparathyroidism. A parathyroid adenoma was removed. Outcome was favorable and the slipped femoral epiphyses did not require a specific treatment.

  18. Prediction of fluid velocity slip at solid surfaces.

    PubMed

    Hansen, J S; Todd, B D; Daivis, Peter J

    2011-07-01

    The observed flow enhancement in highly confining geometries is believed to be caused by fluid velocity slip at the solid wall surface. Here we present a simple and highly accurate method to predict this slip using equilibrium molecular dynamics. Unlike previous equilibrium molecular dynamics methods, it allows us to directly compute the intrinsic wall-fluid friction coefficient rather than an empirical friction coefficient that includes all sources of friction for planar shear flow. The slip length predicted by our method is in excellent agreement with the slip length obtained from direct nonequilibrium molecular dynamics simulations.

  19. Inverting measurements of surface slip on the Superstition Hills fault

    USGS Publications Warehouse

    Boatwright, J.; Budding, K.E.; Sharp, R.V.

    1989-01-01

    We derive and test a set of inversions of surface-slip measurements based on the empirical relation u(t)=uf/(1 + T/t)c proposed by Sharp and Saxton (1989) to estimate the final slip uf, the power-law exponent c, and the power-law duration T. At short times, Sharp's relation behaves like the simple power law, u(t)~u1tc, where u1 is the initial slip, that is, the slip at 1 day after the earthquake. At long times, the slip approaches the final slip asymptotically. The inversions are designed in part to exploit the accuracy of measurements of differential slip; that is, measurements of surface slip which are made relative to a set of nails or stakes emplaced after the earthquake. We apply the inversions to slip measurements made at 53 sites along the Superstition Hills fault for the 11 months following the M=6.2 and 6.6 earthqakes of 24 November 1987. -from Authors

  20. Slip and flow of hard-sphere colloidal glasses.

    PubMed

    Ballesta, P; Besseling, R; Isa, L; Petekidis, G; Poon, W C K

    2008-12-19

    We study the flow of concentrated hard-sphere colloidal suspensions along smooth, nonstick walls using cone-plate rheometry and simultaneous confocal microscopy. In the glass regime, the global flow shows a transition from Herschel-Bulkley behavior at large shear rate to a characteristic Bingham slip response at small rates, absent for ergodic colloidal fluids. Imaging reveals both the "solid" microstructure during full slip and the local nature of the "slip to shear" transition. Both the local and global flow are described by a phenomenological model, and the associated Bingham slip parameters exhibit characteristic scaling with size and concentration of the hard spheres.

  1. Shear-Dependent Boundary Slip in an Aqueous Newtonian Liquid

    SciTech Connect

    Craig, Vincent S. J.; Neto, Chiara; Williams, David R. M.

    2001-07-30

    We report direct measurements of hydrodynamic drainage forces, which show clear evidence of boundary slip in a Newtonian liquid. The degree of boundary slip is found to be a function of the liquid viscosity and the shear rate, as characterized by the slip length, and is up to {approx}20 nm . This has implications for confined biological systems, the permeability of microporous media, and for the lubrication of nanomachines, and will be important in the microcontrol of liquid flow. We also show that current theories of slip do not adequately describe the experimental data.

  2. Slip to the Trench for Great Subduction Earthquakes

    NASA Astrophysics Data System (ADS)

    Mori, J. J.

    2015-12-01

    The 2011 Tohoku-oki earthquake had the largest ever recorded fault slip (40 to 60 meters) on the shallow portion of the subduction zone close to the trench. This large displacement was largely unexpected for this region and was mainly responsible for the very large and damaging tsunami along the northeast coast of Honshu. We investigate the possibility of large slip to the trench in great earthquakes for other subduction zones around the world. Since the trench region is generally far offshore, it is often difficult to resolve the amount of slip from onshore geodetic and strong-motion data. We use a variety of observations, including slip distribution models, aftershock locations, local coastal deformation, and tsunami heights to determine which events likely had large amounts of slip close to the trench. Tsunami earthquakes, such as 1992 Nicaragua and 2006 Java likely had large shallow slip. Some typical subduction earthquakes, such as 1968 Tokachi-oki and 2003 Tokachi-oki (located in regions north of the source area of the 2011 Tohoku-oki earthquake) likely did not.We will discuss possible factors that influence the slip distribution on the shallow area of subduction megathrusts. Using results from the Japan Trench Fast Drilling Project (JFAST) which sampled the fault in the region of large slip, we can begin to understand the conditions of very large fault slip, such as the characteristic fault zone material and level of friction on the fault.

  3. Observations and Modeling of Temporal Variability in Slow Slip Events

    NASA Astrophysics Data System (ADS)

    Hawthorne, Jessica Cleary

    In this thesis, I investigate short-timescale variations in slow slip events in Cascadia. I use these and other observations to assess whether one of the friction laws proposed to govern the slow slip region can adequately reproduce the observed events. In the first observational component, we use borehole strain data to look for tidal variations in the slow slip moment rate in central Cascadia. We find that slow slip is tidally modulated. On average, the moment rate oscillates 25% above and below the mean at the period of the strongest tide. This modulation implies that slow slip is sensitive to small external stresses. It provides a useful constraint on models of slow slip events. In the modeling component of this thesis, we examine features of slow slip events simulated with a rate and state friction law that is velocity-weakening at low slip rates but velocity-strengthening at high slip rates. This is one of three friction laws that have been proposed to govern the frictional strength in the slow slip region. These models parameterize the slow slip region as an elongate rectangle. This mimics the geometry of observed events, which often extend farther along strike than along dip. The simulated events propagate approximately steadily "along strike," and slip rate and stress decay gradually behind the propagating front. The recurrence interval of large events is controlled by the requirement that the strain energy released by slip equal the energy dissipated by friction. We identify the sets of model parameters that allow for episodic large events with the stress drops, slip velocities, and propagation rates seen in Cascadia. Next, we investigate the effect of applying a tidal load to this model. We find that the slip rate varies quasi-sinusoidally, with amplitude proportional to the applied stress. It is possible to choose model parameters that allow the model to reproduce the observed modulation, but if we do so, the model can match only a subset of the

  4. Slip effects in a dewetting polymer microdroplets

    NASA Astrophysics Data System (ADS)

    Chan, T. S.; McGraw, J. D.; Maurer, S.; Salez, T.; Benzaquen, M.; Raphaël, É.; Jacobs, K.; Brinkmann, M.

    2014-11-01

    A non-equilibrium liquid drop sitting on a smooth substrate will contract or spread depending on the equilibrium contact angle and the initial shape of the drop. Previous studies assume a huge separation of length scales between the drop contact size R and the slip length b (typically b / R = 10-6-10-5). One well known example is that of a drop spreading over a completely wetting surface, which follows Tanner's law. In this study, we experimentally and theoretically investigate contractions of microscopic droplets in regimes where these two length scales are not widely separated (b / R = 10-2-1). These regimes become relevant in micro- and nano-fluidic systems. Instead of a quasi-static spherical shape during the evolution, the profiles display more complex shapes in these regimes. We find that: 1) the interface profile near the contact line evolves in a self-similar way in the early stage; 2) depending on b / R , the profile can develop a characteristic bump shape in the intermediate stage of the evolution. 3) at late times, the radius saturates exponentially with a certain time scale, which depends on the slip length.

  5. Frictional slip of granite at hydrothermal conditions

    USGS Publications Warehouse

    Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

    1995-01-01

    To measure the strength, sliding behavior, and friction constitutive properties of faults at hydrothermal conditions, laboratory granite faults containing a layer of granite powder (simulated gouge) were slid. The mechanical results define two regimes. The first regime includes dry granite up to at least 845?? and wet granite below 250??C. In this regime the coefficient of friction is high (?? = 0.7 to 0.8) and depends only modestly on temperature, slip rate, and PH2O. The second regime includes wet granite above ~350??C. In this regime friction decreases considerably with increasing temperature (temperature weakening) and with decreasing slip rate (velocity strengthening). These regimes correspond well to those identified in sliding tests on ultrafine quartz. The results highlight the importance of fluid-assisted deformation processes active in faults at depth and the need for laboratory studies on the roles of additional factors such as fluid chemistry, large displacements, higher concentrations of phyllosilicates, and time-dependent fault healing. -from Authors

  6. Statistics from granular stick-slip experiment

    NASA Astrophysics Data System (ADS)

    Abed Zadeh, Aghil; Bares, Jonathan; Behringer, Robert

    2015-03-01

    We carry out experiments to characterize stick-slip for granular materials. In our experiment, a constant speed stage pulls a slider which rests on a vertical bed of circular photoelastic particles in a 2D system. The stage is connected to the slider by a spring. We measure the force on the spring as well as the slider's acceleration by a force sensor attached to the spring and accelerometers on the slider. The distributions of energy release and time duration of avalanches during slip obey power laws. We apply a novel event recognition approach using wavelets to extract the avalanche properties. We compare statistics from the wavelet approach with those obtained by typical methods, to show how noise can change the distribution of events. We analyze the power spectrum of various quantities to understand the effect of the loading speed and of the spring stiffness on the statistical behavior of the system. Finally, from a more local point of view and by using a high speed camera and the photoelastic properties of our particles, we characterize the internal granular structure during avalanches. This work is supported by NSF Grant DMR1206351 and NASA Grant NNX10AU01G.

  7. Statistics from granular stick-slip experiments

    NASA Astrophysics Data System (ADS)

    Abed Zadeh, Aghil; Bares, Jonathan; Behringer, Robert P.

    2014-11-01

    We carry out experiments to characterize stick-slip for granular materials. In our experiment, a constant speed stage pulls a slider which rests on a vertical bed of circular photoelastic particles in a 2D system. The stage is connected to the slider by a spring. We measure the force on the spring as well as the slider's acceleration by a force sensor attached to the spring and accelerometers on the slider. The distributions of energy release and time duration of avalanches during slip obey power laws. We apply a novel event recognition approach using wavelets to extract the avalanche properties. We compare statistics from the wavelet approach with those obtained by typical methods, to show how noise can change the distribution of events. We analyze the power spectrum of various quantities to understand the effect of the loading speed and of the spring stiffness on the statistical behavior of the system. Finally, from a more local point of view and by using a high speed camera and the photoelastic properties of our particles, we characterize the internal granular structure during avalanches. This work supported by NSF Grant DMR1206351 and NASA Grant NNX10AU01G.

  8. Combined UAVSAR and GPS Estimates of Fault Slip for the M 6.0 South Napa Earthquake

    NASA Astrophysics Data System (ADS)

    Donnellan, A.; Parker, J. W.; Hawkins, B.; Hensley, S.; Jones, C. E.; Owen, S. E.; Moore, A. W.; Wang, J.; Pierce, M. E.; Rundle, J. B.

    2014-12-01

    Combined UAVSAR and GPS Estimates of Fault Slip for the M 6.0 South Napa Earthquake Andrea Donnellan, Jay Parker, Brian Hawkins, Scott Hensley, Cathleen Jones, Susan Owen, Angelyn Moore Jet Propulsion Laboratory, California Institute of Technology Marlon Pierce, Jun Wang Indiana University John Rundle University of California, Davis The South Napa to Santa Rosa area has been observed with NASA's UAVSAR since late 2009 as part of an experiment to monitor areas identified as having a high probability of an earthquake. The M 6.0 South Napa earthquake occurred on 24 August 2014. The area was flown 29 May 2014 preceeding the earthquake, and again on 29 August 2014, five days after the earthquake. The UAVSAR results show slip on a single fault at the south end of the rupture near the epicenter of the event. The rupture branches out into multiple faults further north near the Napa area. A combined inversion of rapid GPS results and the unwrapped UAVSAR interferogram indicate nearly pure strike slip motion. Using this assumption, the UAVSAR data show horizontal right-lateral slip across the fault of 19 cm at the south end of the rupture and increasing to 70 cm northward over a distance of 6.5 km. The joint inversion indicates slip of ~30 cm on a network of sub-parallel faults is concentrated in a zone about 17 km long. The lower depths of the faults are 5-8.5 km. The eastern two sub-parallel faults break the surface, while three faults to the west are buried at depths ranging from 2-6 km with deeper depths to the north and west. The geodetic moment release is equivalent to a M 6.1 event. Additional ruptures are observed in the interferogram, but the inversions suggest that they represent superficial slip that does not contribute to the overall moment release.

  9. The effect of sliding velocity on the mechanical response of an artificial joint in Topopah Spring Member tuff; Yucca Mountain Site Characterization Project

    SciTech Connect

    Olsson, W.A.

    1994-04-01

    A smooth artificial joint in Topopah Spring Member tuff was sheared at constant normal stress at velocities from 0 to 100 {mu}m/s to determine the velocity-dependence of shear strength. Two different initial conditions were used: (1) unprimed -- the joint had been shear stress-free since last application of normal stress, and before renewed shear loading; and (2) primed -- the joint had undergone a slip history after application of normal stress, but before the current shear loading. Observed steady-state rate effects were found to be about 3 times lager than for some other silicate rocks. These different initial conditions affected the character of the stress-slip curve immediately after the onset of slip. Priming the joint causes a peak in the stress-slip response followed by a transient decay to the steady-state stress, i.e., slip weakening. Slide-hold-slide tests exhibit time-dependent strengthening. When the joint was subjected to constant shear stress, no slip was observed; that is, joint creep did not occur. One set of rate data was collected from a surface submerged in tap water, the friction was higher for this surface, but the rate sensitivity was the same as that for surfaces tested in the air-dry condition.

  10. Initiation of unstable slips-microearthquakes by elastic impulses

    NASA Astrophysics Data System (ADS)

    Sobolev, G. A.; Ponomarev, A. V.; Maibuk, Yu. Ya.

    2016-09-01

    A series of laboratory experiments have been carried out with a model of two granite blocks under biaxial compression loading. The experiments are mainly intended for assessing the possibilities of partially releasing the accumulated potential energy. The model was subjected to calibrated mechanical impacts (strokes) which induced elastic impulses. The mechanical stresses, strains, and acoustic emission were recorded. The strokes caused both large slips releasing the stresses down to their initial level and small slips which reduced the stresses by 5-8%. The small slips mostly occurred after the precursory emergence of the low frequency oscillations having low amplitudes. Before the large slips, the stages of speeding-up of the relative motion of the sides of the block contact was observed, similar to those emerging before the natural slips unrelated to the strokes. This feature was not universal: in some cases, the model recovered to the stationary state of the block contact without a large slip. All the slips occurred with a time delay after the stroke. The time delay was shorter when the energy of the blow was higher. With the shorter time delays, the small slip is more likely to occur. The energy of the impacts was by three orders of magnitude lower than the energy accumulated by the model, which points to the triggering mechanism of slip initiation. The series of strokes resulting in the small displacements partially reduced the accumulated energy and prevented the emergence of large motions such as the stick-slip events. If after a series of such blows a large sliding event still occurred, its energy was higher than in the slips unrelated to the impacts. The experiments revealed the difficulties in solving the problem of earthquake hazard reduction by elastic impacts.

  11. Premonitory slip and tidal triggering of earthquakes

    USGS Publications Warehouse

    Lockner, D.A.; Beeler, N.M.

    1999-01-01

    We have conducted a series of laboratory simulations of earthquakes using granite cylinders containing precut bare fault surfaces at 50 MPa confining pressure. Axial shortening rates between 10-4 and 10-6 mm/s were imposed to simulate tectonic loading. Average loading rate was then modulated by the addition of a small-amplitude sine wave to simulate periodic loading due to Earth tides or other sources. The period of the modulating signal ranged from 10 to 10,000 s. For each combination of amplitude and period of the modulating signal, multiple stick-slip events were recorded to determine the degree of correlation between the timing of simulated earthquakes and the imposed periodic loading function. Over the range of parameters studied, the degree of correlation of earthquakes was most sensitive to the amplitude of the periodic loading, with weaker dependence on the period of oscillations and the average loading rate. Accelerating premonitory slip was observed in these experiments and is a controlling factor in determining the conditions under which correlated events occur. In fact, some form of delayed failure is necessary to produce the observed correlations between simulated earthquake timing and characteristics of the periodic loading function. The transition from strongly correlated to weakly correlated model earthquake populations occurred when the amplitude of the periodic loading was approximately 0.05 to 0.1 MPa shear stress (0.03 to 0.06 MPa Coulomb failure function). Lower-amplitude oscillations produced progressively lower correlation levels. Correlations between static stress increases and earthquake aftershocks are found to degrade at similar stress levels. Typical stress variations due to Earth tides are only 0.001 to 0.004 MPa, so that the lack of correlation between Earth tides and earthquakes is also consistent with our findings. A simple extrapolation of our results suggests that approximately 1% of midcrustal earthquakes should be correlated with

  12. Dynamic Dislocation Mechanisms For the Anomalous Slip in a Single-Crystal BCC Metal Oriented for "Single Slip"

    SciTech Connect

    Hsiung, L; La Cruz, C

    2007-01-11

    Dislocation substructures of high-purity Mo single crystals deformed under uniaxial compression at room temperature to an axial strain of 0.6% were investigated in order to elucidate the underlying mechanisms for the {l_brace}0{bar 1}1{r_brace} anomalous slip in bcc metals [1], which is also known as the violation of Schmid law [2]. The test sample was oriented with the stress axis parallel to a nominal ''single-slip'' orientation of [{bar 2} 9 20], in which ({bar 1}01) [111] is the primary slip system that has a maximum Schmid factor (m = 0.5), which requires the lowest stress to operate among the twelve {l_brace}{bar 1}10{r_brace} <111> slip systems. Nevertheless, the recorded stress-strain curve reveals no easy-glide or single-slip stage; work hardening starts immediately after yielding. Moreover, the result of slip trace analysis indicates the occurrence of anomalous slip on both the (011) and (0{bar 1}1) planes, which according to the Schmid law requires relatively higher stresses to operate. TEM examinations of dislocation structures formed on the (101) primary slip plane reveal that in addition to the ({bar 1}01) [111] slip system, the coplanar ({bar 1}01) [1{bar 1}1] slip system which has a much smaller Schmid factor (m = 0.167) is also operative. Similarly, (0{bar 1}1) [111] (m = 0.25) is cooperative with the coplanar (0{bar 1}1) [{bar 1}11] slip system (m = 0.287) on the (0{bar 1}1) slip plane, and (011) [1{bar 1}1] (m = 0.222) is cooperative with the coplanar (011) [11{bar 1}] slip system (m = 0.32) on the (011) plane. The occurrence of {l_brace}0{bar 1}1{r_brace} anomalous slip is accordingly proposed to be originated from the cooperative dislocation motion of the {+-} 1/2 [111] and {+-} 1/2 [1{bar 1}1] dislocations on the ({bar 1}01) slip plane; the mutual interaction and blocking of {+-} 1/2 [111] and {+-} 1/2 [1{bar 1}1] dislocations not only cause an increase of glide resistance to the dislocation motion on the ({bar 1}01) plane but also render the

  13. Crystal plasticity finite element analysis of deformation behaviour in SAC305 solder joint

    NASA Astrophysics Data System (ADS)

    Darbandi, Payam

    Due to the awareness of the potential health hazards associated with the toxicity of lead (Pb), actions have been taken to eliminate or reduce the use of Pb in consumer products. Among those, tin (Sn) solders have been used for the assembly of electronic systems. Anisotropy is of significant importance in all structural metals, but this characteristic is unusually strong in Sn, making Sn based solder joints one of the best examples of the influence of anisotropy. The effect of anisotropy arising from the crystal structure of tin and large grain microstructure on the microstructure and the evolution of constitutive responses of microscale SAC305 solder joints is investigated. Insights into the effects of key microstructural features and dominant plastic deformation mechanisms influencing the measured relative activity of slip systems in SAC305 are obtained from a combination of optical microscopy, orientation imaging microscopy (OIM), slip plane trace analysis and crystal plasticity finite element (CPFE) modeling. Package level SAC305 specimens were subjected to shear deformation in sequential steps and characterized using optical microscopy and OIM to identify the activity of slip systems. X-ray micro Laue diffraction and high energy monochromatic X-ray beam were employed to characterize the joint scale tensile samples to provide necessary information to be able to compare and validate the CPFE model. A CPFE model was developed that can account for relative ease of activating slip systems in SAC305 solder based upon the statistical estimation based on correlation between the critical resolved shear stress and the probability of activating various slip systems. The results from simulations show that the CPFE model developed using the statistical analysis of activity of slip system not only can satisfy the requirements associated with kinematic of plastic deformation in crystal coordinate systems (activity of slip systems) and global coordinate system (shape changes

  14. Partial slip in mesoscale contacts: dependence on contact size.

    PubMed

    Hanke, Sylvia; Petri, Judith; Johannsmann, Diethelm

    2013-09-01

    Using acoustic resonators, we have studied the occurrence and the magnitude of partial slip between glass spheres and polymer surfaces. The measurement relies on the shifts of resonance frequency and bandwidth, Δf and ΔΓ, induced by the contact as well as the dependence of Δf and ΔΓ on the amplitude of oscillation. One often finds a decrease of Δf at elevated amplitudes, which goes back to partial slip (also "microslip"). Building on two different models of partial slip, we derive the frequency-amplitude relation from the force-displacement relation. In accordance with both models, the bandwidth is found to increase with amplitude in the partial slip regime. For the highest amplitudes and largest spheres investigated, one observes a decrease of bandwidth with amplitude, which is interpreted as a transition to gross slip. Deviating from both models of partial slip, Δf is sometimes found to be independent of amplitude in the low-amplitude range. Constant Δf implies linear force-displacement relations. The critical amplitude for the onset of partial slip depends on the contact radius, where partial slip is more pronounced for larger contacts. This finding can be explained by a smooth stress profile at the edge of the contact with no singularity. The stress at the edge might be lowered by nanoscale roughness, by capillary forces, or by the inability of the two surfaces to reestablish a sticking contact at the turning point of the oscillation.

  15. Slip flow through colloidal crystals of varying particle diameter.

    PubMed

    Rogers, Benjamin J; Wirth, Mary J

    2013-01-22

    Slip flow of water through silica colloidal crystals was investigated experimentally for eight different particle diameters, which have hydraulic channel radii ranging from 15 to 800 nm. The particle surfaces were silylated to be low in energy, with a water contact angle of 83°, as determined for a silylated flat surface. Flow rates through centimeter lengths of colloidal crystal were measured using a commercial liquid chromatograph for accurate comparisons of water and toluene flow rates using pressure gradients as high as 10(10) Pa/m. Toluene exhibited no-slip Hagen-Poiseuille flow for all hydraulic channel radii. For water, the slip flow enhancement as a function of hydraulic channel radius was described well by the expected slip flow correction for Hagen-Poiseuille flow, and the data revealed a constant slip length of 63 ± 3 nm. A flow enhancement of 20 ± 2 was observed for the smallest hydraulic channel radius of 15 nm. The amount of slip flow was found to be independent of shear rate over a range of fluid velocities from 0.7 to 5.8 mm/s. The results support the applicability of the slip flow correction for channel radii as small as 15 nm. The work demonstrates that packed beds of submicrometer particles enable slip flow to be employed for high-volume flow rates.

  16. A Transformational Approach to Slip-Slide Factoring

    ERIC Educational Resources Information Center

    Steckroth, Jeffrey

    2015-01-01

    In this "Delving Deeper" article, the author introduces the slip-slide method for solving Algebra 1 mathematics problems. This article compares the traditional method approach of trial and error to the slip-slide method of factoring. Tools that used to be taken for granted now make it possible to investigate relationships visually,…

  17. Role of Slip Mode on Stress Corrosion Cracking Behavior

    NASA Astrophysics Data System (ADS)

    Vasudevan, A. K.; Sadananda, K.

    2011-02-01

    In this article, we examine the effect of aging treatment and the role of planarity of slip on stress corrosion cracking (SCC) behavior in precipitation-hardened alloys. With aging, the slip mode can change from a planar slip in the underage (UA) to a wavy slip in the overage (OA) region. This, in turn, results in sharpening the crack tip in the UA compared to blunting in the OA condition. We propose that the planar slip enhances the stress concentration effects by making the alloys more susceptible to SCC. In addition, the planarity of slip enhances plateau velocities, reduces thresholds for SCC, and reduces component life. We show that the effect of slip planarity is somewhat similar to the effects of mechanically induced stress concentrations such as due to the presence of sharp notches. Aging treatment also causes variations in the matrix and grain boundary (GB) microstructures, along with typical mechanical and SCC properties. These properties include yield stress, work hardening rate, fracture toughness K IC , thresholds K Iscc, and steady-state plateau velocity ( da/ dt). The SCC data for a wide range of ductile alloys including 7050, 7075, 5083, 5456 Al, MAR M steels, and solid solution copper-base alloys are collected from the literature. Our assertion is that slip mode and the resulting stress concentration are important factors in SCC behavior. This is further supported by similar observations in many other systems including some steels, Al alloys, and Cu alloys.

  18. Slip Flow through Colloidal Crystals of Varying Particle Diameter

    PubMed Central

    Rogers, Benjamin J.; Wirth, Mary J.

    2012-01-01

    Slip flow of water through silica colloidal crystals was investigated experimentally for 8 different particle diameters, which have hydraulic channel radii ranging from 15 nm to 800 nm. The particle surfaces were silylated to be low in energy, with a water contact angle of 83°, as determined for a silylated flat surface. Flow rates through centimeter lengths of colloidal crystal were measured using a commercial liquid chromatograph for accurate comparisons of water and toluene flow rates using pressure gradients as high as 1010 Pa/m. Toluene exhibited no-slip Hagen-Poiseuille flow for all hydraulic channel radii. For water, the slip flow enhancement as a function of hydraulic channel radius was described well by the expected slip flow correction for Hagen-Poiseuille flow, and the data revealed a constant slip length of 63±3 nm. A flow enhancement of 20±2 was observed for the smallest hydraulic channel radius of 15 nm. The amount of slip flow was found to be independent of shear rate over a range of fluid velocities from 0.7 to 5.8 mm/s. The results support the applicability of the slip flow correction for channel radii as small as 15 nm. The work demonstrates that packed beds of submicrometer particles enable slip flow to be employed for high volume flow rates. PMID:23237590

  19. Slip, trip, and fall injuries among nursing care facility workers.

    PubMed

    Bell, Jennifer L; Collins, James W; Tiesman, Hope M; Ridenour, Marilyn; Konda, Srinivas; Wolf, Laurie; Evanoff, Bradley

    2013-04-01

    The objective of this research was to describe the slip, trip, and fall injury experience and trends in a population of nursing home workers, identify risk factors for slip, trip, and fall injuries, and develop prevention strategies for slip, trip, and fall hazards. Workers' compensation injury claims data and payroll data from 1996 through 2003 were obtained from six nursing homes and used to calculate injury incidence rates. Narrative information was used to describe details of slip, trip, and fall events. A total of 86 slip, trip, and fall-related workers' compensation claims were filed during the 8-year period. Slip, trip, and fall claim rates showed a nonsignificant increase during the 8-year period. Most slips, trips, and falls were attributed to hazards that can be mitigated (e.g., water on the floor or loose cords in a walkway). Nursing home workers experience more slip, trip, and fall-related injury claims than workers in other industries. Preventive programs should be implemented and evaluated in this industry. PMID:23521142

  20. Regulating the working properties of porcelain slip

    SciTech Connect

    Karpilovskii, L.P.; Kralinina, L.N.; Makarov, V.A.; Sidorenko, Z.I.

    1986-05-01

    It was decided to introduce changes in the recipe of the clay part of the raw material to provide a reduction in the density and a restoration of the Prosyyanovsk kaolin (PK) slip's fluidity, the volume of the PK batch would be maintained, and the working properties of the body could be insured within the same limits as prevailed before recipe of the stone materials and the chemical composition of the porcelain would be left unchanged. The results indicate the effectiveness of using the analytical method for clay suspensions for operational assessment of the technical properties of raw materials and regulating the working properties of the body. The method of filtration analysis and determination of the elastic properties of the suspension can also be recommended for use in benefication combines. The advantage of the methods consists in the rapidity of carrying out the analysis which means where necessary can operationally intervene in the technological process.

  1. Rolling and slipping motion of Euler's disk

    NASA Astrophysics Data System (ADS)

    Caps, H.; Dorbolo, S.; Ponte, S.; Croisier, H.; Vandewalle, N.

    2004-05-01

    We present an experimental study of the motion of a circular disk spun onto a table. With the help of a high speed video system, the temporal evolution of (i) the inclination angle α , (ii) the angular velocity ω , and (iii) the precession rate Ω are studied. The influence of the mass of the disk as well as the friction between the disk and the supporting surface are considered. Both inclination angle and angular velocity are observed to decrease according to a power law. We also show that the precession rate diverges as the motion stops. Measurements are performed very near the collapse as well as on long range times. Times to collapse have been also measured. Results are compared with previous theoretical and experimental works. The major source of energy dissipation is found to be the slipping of the disk on the plane.

  2. Oscillatory Magnetogasdynamic Slip Flow in a Microchannel

    NASA Astrophysics Data System (ADS)

    Agarwal, Ramesh

    2009-11-01

    The problem of pressure driven Magnetogasdynamic (MGD) slip flow with small rarefaction through a long micro-channel is considered. The flow is driven by steady or oscillatory pressure gradient. The study of MGD flows in microchannels is of great interest since they occur in magnetic thin films and other electromagnetic micro-scale devices. In obtaining the micro-fluidic solutions in the presence of a magnetic field, some additional physical, mathematical and numerical issues need to be considered. These issues deal with the scaling laws for micro-scale MHD flows and the relevant parameters such as Mach number, Reynolds number, Hartmann number, magnetic Reynolds number, and Knudsen number. For planar constant area micro-channel, it is possible to obtain the analytical solutions for both steady and oscillatory pressure driven flows. As physically expected, the higher value of the magnetic field (higher Hartmann number) flattens the velocity profile in the channel.

  3. Laboratory Observations of the Spectrum of Fault Slip Behaviors

    NASA Astrophysics Data System (ADS)

    Marone, Chris

    2016-04-01

    Slow earthquakes, tectonic fault tremor, and low frequency earthquakes represent an important enigma in earthquake science. In the standard model of earthquake physics elastic energy is released catastrophically as the fault weakens and dynamic rupture expands at speeds measured in km/s. The spectral content of the resulting seismic waves is understood in terms of a source model based on elastodynamic rupture propagation. However, faults also fail in slow earthquakes and there is no such understanding of rupture dynamics, seismic spectra, or source scaling relations in these cases. The mechanics of slow earthquakes are poorly understood in part because there are few systematic laboratory observations that can be used to identify the underlying mechanics. Here, I summarize and discuss results from numerical models of slow slip using rate/state friction laws and recent lab studies showing slow slip and the full spectrum of stick-slip behaviors. Early lab studies saw slow slip during frictional sliding or in association with dehydration or ductile flow; however, they did not include systematic measurements that could be used to isolate the underlying mechanics. Numerical studies based on rate/state friction also document slow slip and chaotic forms of stick-slip, however they require special conditions including two state variable frictional behavior. Recent lab work sheds new light on slow earthquakes by showing: 1) that repetitive, slow stick-slip can occur if the fault friction-velocity relation becomes positive during slip acceleration, and 2) that slow slip and the full spectrum of fault slip modes can occur if loading stiffness k matches the fault zone critical rheologic stiffness kc given by the frictional weakening rate and the critical frictional distance. These data show that the key control parameter for stress drop, slip speed, and slip duration is the non dimensional stiffness k' = k/kc, with the spectrum of fast to slow slip mode occurring in a narrow

  4. Slip Distribution and Seismic Moment of the 2010 and 1960 Chilean Earthquakes Inferred from Tsunami Waveforms and Coastal Geodetic Data

    NASA Astrophysics Data System (ADS)

    Fujii, Yushiro; Satake, Kenji

    2013-09-01

    The slip distribution and seismic moment of the 2010 and 1960 Chilean earthquakes were estimated from tsunami and coastal geodetic data. These two earthquakes generated transoceanic tsunamis, and the waveforms were recorded around the Pacific Ocean. In addition, coseismic coastal uplift and subsidence were measured around the source areas. For the 27 February 2010 Maule earthquake, inversion of the tsunami waveforms recorded at nearby coastal tide gauge and Deep Ocean Assessment and Reporting of Tsunamis (DART) stations combined with coastal geodetic data suggest two asperities: a northern one beneath the coast of Constitucion and a southern one around the Arauco Peninsula. The total fault length is approximately 400 km with seismic moment of 1.7 × 1022 Nm (Mw 8.8). The offshore DART tsunami waveforms require fault slips beneath the coasts, but the exact locations are better estimated by coastal geodetic data. The 22 May 1960 earthquake produced very large, ~30 m, slip off Valdivia. Joint inversion of tsunami waveforms, at tide gauge stations in South America, with coastal geodetic and leveling data shows total fault length of ~800 km and seismic moment of 7.2 × 1022 Nm (Mw 9.2). The seismic moment estimated from tsunami or joint inversion is similar to previous estimates from geodetic data, but much smaller than the results from seismic data analysis.

  5. Proposed Cavity for Reduced Slip-Stacking Loss

    SciTech Connect

    Eldred, J.; Zwaska, R.

    2015-06-01

    This paper employs a novel dynamical mechanism to improve the performance of slip-stacking. Slip-stacking in an accumulation technique used at Fermilab since 2004 which nearly double the proton intensity. During slip-stacking, the Recycler or the Main Injector stores two particles beams that spatially overlap but have different momenta. The two particle beams are longitudinally focused by two 53 MHz 100 kV RF cavities with a small frequency difference between them. We propose an additional 106 MHz 20 kV RF cavity, with a frequency at the double the average of the upper and lower main RF frequencies. In simulation, we find the proposed RF cavity significantly enhances the stable bucket area and reduces slip-stacking losses under reasonable injection scenarios. We quantify and map the stability of the parameter space for any accelerator implementing slip-stacking with the addition of a harmonic RF cavity.

  6. Nailing down the slip rate of the Altyn Tagh fault

    NASA Astrophysics Data System (ADS)

    He, Jiankun; Vernant, Philippe; Chéry, Jean; Wang, Weimin; Lu, Shuangjiang; Ku, Wenfei; Xia, Wenhai; Bilham, Roger

    2013-10-01

    estimates of the geodetic and geologic slip rates of the 1500 km long Altyn Tagh fault bordering the northern edge of the Tibetan plateau vary by a factor of five. Proposed reasons for these discrepancies include poor GPS geometry, interpretative errors in terrace morphology, and changes in fault slip rate over time. Here we present results from a new dense GPS array orthogonal to the fault at ~86.2°E that indicates a velocity of 9.0-3.2/+4.4 mm/yr, in close agreement with geomorphologic estimates at the same location. Our estimated geodetic slip rate is consistent with recent geological slip rates based on terrace offsets. The resulting mean combined geological and geodetic slip rate (9.0 ± 4.0 mm/yr) is remarkably uniform for the central ~800 km of the Altyn Tagh fault, significantly lower than early kinematic estimates and consistent with deformation elsewhere in Tibet and central Asia.

  7. The experimentalanalysis of the slip in the rubber belt CVT

    NASA Astrophysics Data System (ADS)

    Grzegożek, W.; Kot, A.

    2016-09-01

    This work deals with the analysis of the speed losses in CVT. The bench tests have been conducted on the scooter CVT equipped with the centrifugal regulation system. This solution is typical for this type of vehicles so the conducted experiments refer to real exploitation conditions. The slip has been defined on the base of the difference between speed ratios obtained from the angular speeds and the belt pitch radii. This approach corresponds with the Dittrich model. The non-linear dependence between the slip and the transmitted torque has been obtained for the constant gear ratio. Also non-linear dependence between the slip and the gear ratio has been received for constant torque. The amount of slip value indicates that this is significant part of the total power losses as it has been described by Bertini. However it clashes with the Chen researches, where the slip corresponds with the marginal part of the overall losses.

  8. Learning and Prediction of Slip from Visual Information

    NASA Technical Reports Server (NTRS)

    Angelova, Anelia; Matthies, Larry; Helmick, Daniel; Perona, Pietro

    2007-01-01

    This paper presents an approach for slip prediction from a distance for wheeled ground robots using visual information as input. Large amounts of slippage which can occur on certain surfaces, such as sandy slopes, will negatively affect rover mobility. Therefore, obtaining information about slip before entering such terrain can be very useful for better planning and avoiding these areas. To address this problem, terrain appearance and geometry information about map cells are correlated to the slip measured by the rover while traversing each cell. This relationship is learned from previous experience, so slip can be predicted remotely from visual information only. The proposed method consists of terrain type recognition and nonlinear regression modeling. The method has been implemented and tested offline on several off-road terrains including: soil, sand, gravel, and woodchips. The final slip prediction error is about 20%. The system is intended for improved navigation on steep slopes and rough terrain for Mars rovers.

  9. Rock mechanics. Superplastic nanofibrous slip zones control seismogenic fault friction.

    PubMed

    Verberne, Berend A; Plümper, Oliver; de Winter, D A Matthijs; Spiers, Christopher J

    2014-12-12

    Understanding the internal mechanisms controlling fault friction is crucial for understanding seismogenic slip on active faults. Displacement in such fault zones is frequently localized on highly reflective (mirrorlike) slip surfaces, coated with thin films of nanogranular fault rock. We show that mirror-slip surfaces developed in experimentally simulated calcite faults consist of aligned nanogranular chains or fibers that are ductile at room conditions. These microstructures and associated frictional data suggest a fault-slip mechanism resembling classical Ashby-Verrall superplasticity, capable of producing unstable fault slip. Diffusive mass transfer in nanocrystalline calcite gouge is shown to be fast enough for this mechanism to control seismogenesis in limestone terrains. With nanogranular fault surfaces becoming increasingly recognized in crustal faults, the proposed mechanism may be generally relevant to crustal seismogenesis.

  10. Comparison of Joint Modeling Approaches Including Eulerian Sliding Interfaces

    SciTech Connect

    Lomov, I; Antoun, T; Vorobiev, O

    2009-12-16

    Accurate representation of discontinuities such as joints and faults is a key ingredient for high fidelity modeling of shock propagation in geologic media. The following study was done to improve treatment of discontinuities (joints) in the Eulerian hydrocode GEODYN (Lomov and Liu 2005). Lagrangian methods with conforming meshes and explicit inclusion of joints in the geologic model are well suited for such an analysis. Unfortunately, current meshing tools are unable to automatically generate adequate hexahedral meshes for large numbers of irregular polyhedra. Another concern is that joint stiffness in such explicit computations requires significantly reduced time steps, with negative implications for both the efficiency and quality of the numerical solution. An alternative approach is to use non-conforming meshes and embed joint information into regular computational elements. However, once slip displacement on the joints become comparable to the zone size, Lagrangian (even non-conforming) meshes could suffer from tangling and decreased time step problems. The use of non-conforming meshes in an Eulerian solver may alleviate these difficulties and provide a viable numerical approach for modeling the effects of faults on the dynamic response of geologic materials. We studied shock propagation in jointed/faulted media using a Lagrangian and two Eulerian approaches. To investigate the accuracy of this joint treatment the GEODYN calculations have been compared with results from the Lagrangian code GEODYN-L which uses an explicit treatment of joints via common plane contact. We explore two approaches to joint treatment in the code, one for joints with finite thickness and the other for tight joints. In all cases the sliding interfaces are tracked explicitly without homogenization or blending the joint and block response into an average response. In general, rock joints will introduce an increase in normal compliance in addition to a reduction in shear strength. In the

  11. Imaging fault slip variation along the central San Andreas fault from satellite, airborne InSAR and GPS

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Lundgren, P.; Fielding, E. J.; Hensley, S.

    2011-12-01

    's flight paths are optimized for fault parallel motion sensitivity, whereas the ALOS satellite data were almost exclusively acquired on ascending paths that looked nearly perpendicular to the fault strike. Joint analysis of UAVSAR and ALOS RPI measurements show clear variability in deformation along fault strike. Initial modeling at selected fault transects from the creeping section using UAVSAR data suggests fault creep increases from the surface to a shallower depth and decreases at lower upper crustal depths (~6-9 km). The fault slip rate at depths greater than 12 km is weakly constrained and subject to long wavelength noise components. We are examining the integrated resolution capability of UAVSAR, ALOS, and GPS for estimating fault slip with the goal of mapping fault slip along the entire length of the CSAF in a systematic imaging effort.

  12. Local tsunamis and distributed slip at the source

    USGS Publications Warehouse

    Geist, E.L.; Dmowska, R.

    1999-01-01

    Variations in the local tsunami wave field are examined in relation to heterogeneous slip distributions that are characteristic of many shallow subduction zone earthquakes. Assumptions inherent in calculating the coseismic vertical displacement field that defines the initial condition for tsunami propagation are examined. By comparing the seafloor displacement from uniform slip to that from an ideal static crack, we demonstrate that dip-directed slip variations significantly affect the initial cross-sectional wave profile. Because of the hydrodynamic stability of tsunami wave forms, these effects directly impact estimates of maximum runup from the local tsunami. In most cases, an assumption of uniform slip in the dip direction significantly underestimates the maximum amplitude and leading wave steepness of the local tsunami. Whereas dip-directed slip variations affect the initial wave profile, strike-directed slip variations result in wavefront-parallel changes in amplitude that are largely preserved during propagation from the source region toward shore, owing to the effects of refraction. Tests of discretizing slip distributions indicate that small fault surface elements of dimensions similar to the source depth can acceptably approximate the vertical displacement field in comparison to continuous slip distributions. Crack models for tsunamis generated by shallow subduction zone earthquakes indicate that a rupture intersecting the free surface results in approximately twice the average slip. Therefore, the observation of higher slip associated with tsunami earthquakes relative to typical subduction zone earthquakes of the same magnitude suggests that tsunami earthquakes involve rupture of the seafloor, whereas rupture of deeper subduction zone earthquakes may be imbedded and not reach the seafloor.

  13. Constraining fault constitutive behavior with slip and stress heterogeneity

    USGS Publications Warehouse

    Aagaard, B.T.; Heaton, T.H.

    2008-01-01

    We study how enforcing self-consistency in the statistical properties of the preshear and postshear stress on a fault can be used to constrain fault constitutive behavior beyond that required to produce a desired spatial and temporal evolution of slip in a single event. We explore features of rupture dynamics that (1) lead to slip heterogeneity in earthquake ruptures and (2) maintain these conditions following rupture, so that the stress field is compatible with the generation of aftershocks and facilitates heterogeneous slip in subsequent events. Our three-dimensional fmite element simulations of magnitude 7 events on a vertical, planar strike-slip fault show that the conditions that lead to slip heterogeneity remain in place after large events when the dynamic stress drop (initial shear stress) and breakdown work (fracture energy) are spatially heterogeneous. In these models the breakdown work is on the order of MJ/m2, which is comparable to the radiated energy. These conditions producing slip heterogeneity also tend to produce narrower slip pulses independent of a slip rate dependence in the fault constitutive model. An alternative mechanism for generating these confined slip pulses appears to be fault constitutive models that have a stronger rate dependence, which also makes them difficult to implement in numerical models. We hypothesize that self-consistent ruptures could also be produced by very narrow slip pulses propagating in a self-sustaining heterogeneous stress field with breakdown work comparable to fracture energy estimates of kJ/M2. Copyright 2008 by the American Geophysical Union.

  14. Lattice Boltzmann Simulations of Skin-Friction Drag Reduction in Turbulent Channel Flow with Slip/No Slip Wall Ridges

    NASA Astrophysics Data System (ADS)

    Rastegari, Amirreza; Akhavan, Rayhaneh

    2011-11-01

    To gain a better understanding of the mechanisms at work in skin friction drag reduction with superhydrophobic surfaces, Lattice Boltzmann simulations were performed in turbulent channels with alternating slip/no slip ridges on the walls. Simulations were performed in turbulent channels of size 5 h × 2 . 5 × 2 h and 10 h × 5 h × 2 h at a base Reynolds number of Reτ ~ 230 . Alternating slip/no slip ridges of width 4 <= w + <= 140 , aligned in the streamwise direction, all with the same fractional area of slip boundary, were studied. Drag reductions of 4%, 8%, 21%, 33% and 47%, corresponding to slip velocities of Uslip /Ubulk = 0 . 05 , 0.1, 0.26, 0.31 and 0.36 were observed for w + = g + = 4, 8, 40, 70 and 140, respectively. The mean velocity profiles display the characteristics of combined slip described by Min and Kim [Min et al. 2004]. The streamwise and spanwise turbulence intensities show large slips at the wall, the magnitude of which increases with increasing drag reduction. Examination of the anisotropy invariant maps shows a shift of turbulence structure towards the one-dimensional turbulence limit near the wall with increasing drag reduction. For z+ > 25 , the turbulence structure returns to the isotropic limit.

  15. Observations of premonitory acoustic emission and slip nucleation during a stick slip experiment in smooth faulted Westerly granite

    USGS Publications Warehouse

    Thompson, B.D.; Young, R.P.; Lockner, D.A.

    2005-01-01

    To investigate laboratory earthquakes, stick-slip events were induced on a saw-cut Westerly granite sample by triaxial loading at 150 MPa confining pressure. Acoustic emissions (AE) were monitored using an innovative continuous waveform recorder. The first motion of each stick slip was recorded as a large-amplitude AE signal. These events source locate onto the saw-cut fault plane, implying that they represent the nucleation sites of the dynamic failure stick-slip events. The precise location of nucleation varied between events and was probably controlled by heterogeneity of stress or surface conditions on the fault. The initial nucleation diameter of each dynamic instability was inferred to be less than 3 mm. A small number of AE were recorded prior to each macro slip event. For the second and third slip events, premonitory AE source mechanisms mimic the large scale fault plane geometry. Copyright 2005 by the American Geophysical Union.

  16. Historic creep rate and potential for seismic slip along the Hayward Fault, California

    USGS Publications Warehouse

    Lienkaemper, J.J.; Borchardt, G.; Lisowski, M.

    1991-01-01

    southern (1868) segment of the fault and ≥ 1.4 m in the northern (1836?) segment. Subtracting surface creep rates from a long-term slip rate of 9 mm/yr gives present potential for surface slip in large earthquakes of up to 0.8 m, with an average of 0.6 m in the northern segment and 0.4 m in the southern segment. We present a simple hypothesis for rupture potential that is compatible with historic creep rate, microseismicity distribution, and geodetic data. If seismic rupture occurs on segments 41 km long by 10 km deep (7 km fully locked, 3 km creeping), today's potential for seismic moment release is 1.4 × 1019 and 1.1 × 1019 N m for both 1836? and 1868 segments, respectively, and 2.5 × 1019 N m for both segments jointly. Converting moment to magnitude gives ML 6.8 in the northern segment, ML 6.7 in the southern segment, and ML 7.0 for simultaneous rupture of both.

  17. Effect of Water on High Pressure Olivine Slip Systems Activity

    NASA Astrophysics Data System (ADS)

    Girard, J.; Chen, J.; Raterron, P. C.; Holyoke, C. W.

    2012-12-01

    Seismologic studies of the Earth's shallow (Z<220 km) upper mantle have observed seismic anisotropy parallel to the direction of plate movement and have related this observation to alignment of olivine [100] due to shearing related to convection. These observations have been reinforced by field-based and experimental investigations which observe evidence that [100] slip is dominant at low pressures and water contents. However, direct evidence of the dominant slip system in the deep upper mantle (Z>220 km) is limited to a few studies of xenoliths which have LPOs consistent with [001] slip. Experimental studies of dry single crystals and polycrystals indicate that [001] slip becomes dominant at pressures > 8 GPa. However, water contents in the mantle are significant (~1000 H/106 Si) and we do not know how the slip systems of olivine are affected by higher water contents at high pressures. In order to investigate the effect of pressure on slip systems activities in olivine deformed in wet conditions, deformation experiments were carried out on single crystals, at pressure ranging from 4 to 8 GPa and temperature between 1373 and 1473 K in the Deformation-DIA apparatus (D-DIA) of the X17B2 beamline of the NSLS (NY, USA). Specimen were deformed in uniaxial compression along [110]c, [011]c and [101]c crystallographic directions, promoting the activation of, respectively, [100](010), [001](010) slip systems, and simultaneously [100](001) and [001](100) slip systems. Talc sleeves about the annulus of the single crystals were used as source of water during deformation. In addition, run products investigation using a micro-focused IR beam at the U2 beamline enables accurate mapping of the water content across the deformed single crystals using FTIR spectroscopy, while specimen deformation microstructures were investigated by TEM. We observe a slip-system transition in wet specimen occurring at lower pressure than that observed by Raterron et al. (2007) in dry specimens. For

  18. Strain Wave during the Transient Process of Fault Unstable Slip

    NASA Astrophysics Data System (ADS)

    Guo, L.; Liu, L.

    2011-12-01

    The "stick-slip" model was proposed as an important mechanism for shallow-focus earthquakes. The study on the transient process of fault unstable slip failure is helpful for understanding the earthquake preparatory process, the mechanism of energy released, the precursor and after shake effect. Double shear frictional experiments are conducted for simulating "stick-slip" phenomenon, and a specially designed multi-channel super dynamic strain field observation system is employed to acquire dada continuously with the sample rate of 3,400 samples/second. The rock deformation process can be recorded in detail, especially in the moment of unstable slip (The unstable slip duration is less than two second in experiments). The strain results from super dynamic strain field observation system show that multi-frequency components and tremendous amplitude fluctuation are included in strain signals along the fault. There are three clear phases during the unstable slip progress: pre-slip (phase I), high-frequency strain vibration (phase II) and strain regulating to stop (phase III). Each phase has its own characteristics on duration, strain rate, frequency, amplitude and energy release. There are strong fluctuations in duration of approximately 70ms in phase II. The frequency and maximum amplitude are 300-400Hz and 150~300μɛ respectively. Main strain energy release takes place at phase II, less than one-tenth of the total slip time, so that the whole course of dislocation or stress drop would not be taken as earthquake simply at least in laboratory. The phase characteristic of the strain wave is probably its inherent attribute of unstable slip process and independent of dynamical loading conditions. The elastic rebound phenomena, considered as one classic earthquake generation model, can be observed clearly by analyzing the rotation of the principal strain axis with strain variation. The rotated angle ranges from 5° to 15° typically. The value and location of precursor slip

  19. Joint x-ray

    MedlinePlus

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  20. Joint Instability and Osteoarthritis

    PubMed Central

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

  1. Rupture dynamics with energy loss outside the slip zone

    USGS Publications Warehouse

    Andrews, D.J.

    2005-01-01

    Energy loss in a fault damage zone, outside the slip zone, contributes to the fracture energy that determines rupture velocity of an earthquake. A nonelastic two-dimensional dynamic calculation is done in which the slip zone is modeled as a fault plane and material off the fault is subject to a Coulomb yield condition. In a mode 2 crack-like solution in which an abrupt uniform drop of shear traction on the fault spreads from a point, Coulomb yielding occurs on the extensional side of the fault. Plastic strain is distributed with uniform magnitude along the fault, and it has a thickness normal to the fault proportional to propagation distance. Energy loss off the fault is also proportional to propagation distance, and it can become much larger than energy loss on the fault specified by the fault constitutive relation. The slip velocity function could be produced in an equivalent elastic problem by a slip-weakening friction law with breakdown slip Dc increasing with distance. Fracture energy G and equivalent Dc will be different in ruptures with different initiation points and stress drops, so they are not constitutive properties; they are determined by the dynamic solution that arrives at a particular point. Peak slip velocity is, however, a property of a fault location. Nonelastic response can be mimicked by imposing a limit on slip velocity on a fault in an elastic medium.

  2. Stick-Slip Friction of PDMS Surfaces for Bioinspired Adhesives.

    PubMed

    Xue, Longjian; Pham, Jonathan T; Iturri, Jagoba; Del Campo, Aránzazu

    2016-03-15

    Friction plays an important role in the adhesion of many climbing organisms, such as the gecko. During the shearing between two surfaces, periodic stick-slip behavior is often observed and may be critical to the adhesion of gecko setae and gecko-inspired adhesives. Here, we investigate the influence of short oligomers and pendent chains on the stick-slip friction of polydimethylsiloxane (PDMS), a commonly used material for bioinspired adhesives. Three different stick-slip patterns were observed on these surfaces (flat or microstructured) depending on the presence or absence of oligomers and their ability to diffuse out of the material. After washing samples to remove any untethered oligomeric chains, or after oxygen plasma treatment to convert the surface to a thin layer of silica, we decouple the contributions of stiffness, oligomers, and pendant chains to the stick-slip behavior. The stick phase is mainly controlled by the stiffness while the amount of untethered oligomers and pendant chains available at the contact interface defines the slip phase. A large amount of oligomers and pendant chains resulted in a large slip time, dominating the period of stick-slip motion. PMID:26903477

  3. Can slip heterogeneity be linked to earthquake recurrence?

    NASA Astrophysics Data System (ADS)

    Chen, Kate Huihsuan; Chen, Iyin; Kim, Ahyi

    2016-07-01

    The rupture process of two M4 repeating earthquake sequences in eastern Taiwan with contrasting recurrence behavior is investigated to demonstrate a link between slip heterogeneity and earthquake recurrence. The M3.6-3.8 quasiperiodic repeating earthquakes characterized by 3 years recurrence interval reveal overlapped slip concentrations. Inferred slip distribution for each event illustrates two asperities with peak slip of 47.7 cm and peak stress drop of 151.1 MPa. Under the influence of nearby M6.9 event, the M4.3-4.8 repeating earthquakes separated only by 6-87 min, however, reveal an aperiodic manner. There is a distinct rupture characteristic without overlap in the slip areas, suggesting that shortening of the recurrence interval by the nearby large earthquake may change the slip heterogeneity in a repeatedly ruptured asperity. We conclude that the inherent heterogeneity of stress and strength could influence the distribution of coseismic slip, which is strongly tied to the recurrence behavior.

  4. Sequence of deformations recorded in joints and faults, Arches National Park, Utah

    NASA Astrophysics Data System (ADS)

    Zhao, Guozhu; Johnson, Arvid M.

    1992-02-01

    Faults and joints in an area of essentially undeformed rocks on a limb of a salt anticline in Utah record a surprisingly complex deformational history. Most of the faults started as widely-spaced zones of deformation bands accommodating a few cm of strike-slip. Some were subsequently opened as joints, then were sheared with a sense opposite that of the original faults. Other faults in the Garden Area are fractures that started as joints, then were subsequently sheared. The sense of shear changes across the area, however, and the pattern of shearing is the pattern that would be produced by bending of joint-bounded slabs about a vertical axis. Slip on the faults and joints produced a total regional strain of about 0.15%. Examination of relations among the structures indicates the following deformational history: first were conjugate, strike-slip faults oriented N30°E or N60°E, reflecting zero vertical strain (and presumably vertical intermediate compression), maximum compression in the NE direction (normal to the axis of Salt Valley), and maximum extension in the SE direction. The faults are of the deformation-band variety and so, presumably formed when the rocks were several kilometers deep. Deformation bands never again formed in these rocks. Subsequent fracturing was mode I, tension cracking. Second, tension in the SE direction (or minimum compression in the SE direction and pore-water pressure exceeding the minimum compression), parallel to the long axis of the Salt Valley anticline, opened joints along some of the weak deformation-band faults, causing them to become jointed faults. The orientation of minimum compression was unchanged, but the orientations of the maximum and intermediate principal stresses are unknown and may have changed. Third, systematic zones of joints formed, cutting across the band faults without deviating in trend throughout most of the Garden Area, but interacting with the open jointed faults locally. The direction of tension (or

  5. Spacesuit mobility knee joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1979-01-01

    Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  6. Spacesuit mobility joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1978-01-01

    Joints for use in interconnecting adjacent segments of an hermetically sealed spacesuit which have low torques, low leakage and a high degree of reliability are described. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics. Linkages which restrain the joint from longitudinal distension and a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli are featured. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  7. Local void and slip model used in BODYFIT-2PE

    SciTech Connect

    Chen, B.C.J.; Chien, T.H.; Kim, J.H.; Lellouche, G.S.

    1983-01-01

    A local void and slip model has been proposed for a two-phase flow without the need of fitting any empirical parameters. This model is based on the assumption that all bubbles have reached their terminal rise velocities in the two-phase region. This simple model seems to provide reasonable calculational results when compared with the experimental data and other void and slip models. It provides a means to account for the void and slip of a two-phase flow on a local basis. This is particularly suitable for a fine mesh thermal-hydraulic computer program such as BODYFIT-2PE.

  8. Local Flow Field and Slip Length of Superhydrophobic Surfaces.

    PubMed

    Schäffel, David; Koynov, Kaloian; Vollmer, Doris; Butt, Hans-Jürgen; Schönecker, Clarissa

    2016-04-01

    While the global slippage of water past superhydrophobic surfaces has attracted wide interest, the local distribution of slip still remains unclear. Using fluorescence correlation spectroscopy, we performed detailed measurements of the local flow field and slip length for water in the Cassie state on a microstructured superhydrophobic surface. We revealed that the local slip length is finite, nonconstant, anisotropic, and sensitive to the presence of surfactants. In combination with numerical calculations of the flow, we can explain all these properties by the local hydrodynamics. PMID:27081981

  9. On the Micromechanisms of Anomalous Slip in BCC Metals

    SciTech Connect

    Hsiung, L L

    2005-09-06

    Dislocation substructures developed in high-purity Mo single crystals deformed under uniaxial compression at room temperature to a total strain of {approx} 0.5% with a strain rate of 1 s{sup -1} have been investigated using transmission electron microscopy (TEM) techniques in order to elucidate the underlying micromechanisms of the anomalous operation of {l_brace}0{bar 1}1{r_brace} slip systems, i.e. Schmid-law violation, in bcc metals. The crystals were oriented with the stress axis parallel to a nominal single-slip orientation of [{bar 2}920], in which the ({bar 1}01)[111] slip system is the only system having a maximum value of Schmid factor (m = 0.5). Nevertheless, the recorded stress-strain curve reveals no single-slip or easy-glide stage, and the anomalous slip occurs in both (011) and (0{bar 1}1) planes. TEM examination of the dislocation structure in the ({bar 1}01) primary slip plane reveals that in addition to the operation of the ({bar 1}01)[111] slip system, the coplanar ({bar 1}01)[1{bar 1}1] slip system that has a much smaller Schmid factor (m = 0.167) is also operative. Similarly, the (0{bar 1}1)[111] slip system (m = 0.25) is cooperative with the coplanar (0{bar 1}1)[{bar 1}11] system (m = 0.287), and the (011)[1{bar 1}1] slip system (m = 0.222) is cooperative with the coplanar (011)[11{bar 1}] system (m = 0.32). The occurrence of {l_brace}0{bar 1}1{r_brace} anomalous slip is accordingly proposed to be initiated from the cooperative dislocation multiplication and mutual trapping and blocking of 1/2[111] and 1/2[1{bar 1}1] coplanar dislocation arrays in the ({bar 1}01) plane. The resulted internal stresses render the propagation of both 1/2[111] and 1/2[1{bar 1}1] screw dislocations from the ({bar 1}01) plane onto the {l_brace}0{bar 1}1{r_brace} planes and subsequently result in the occurrence of anomalous slip.

  10. Micro PIV measurement of slip flow on a hydrogel surface

    NASA Astrophysics Data System (ADS)

    Kikuchi, K.; Mochizuki, O.

    2014-06-01

    Slip flow on a hydrogel surface was investigated in order to clarify the effect of drag reduction on the aqueous surface of living things. Thin-film flow along the hydrogel surface was measured by using a micro PIV (particle image velocimetry) system for comparison with theoretical velocity distribution which satisfied the non-slip condition on a solid surface. The slip flow on the hydrogel was found to be related to the degree of swelling and molecular weight of the hydrogel materials. This shows the possibility of a reduction in wall shear stress as a result of the decrease in the velocity gradient near a wall surface.

  11. A Simplified Lateral Hinge Approach to the Proximal Interphalangeal Joint.

    PubMed

    Bain, Gregory I; McGuire, Duncan T; McGrath, Aleksandra M

    2015-09-01

    Proximal interphalangeal joint replacement is an effective treatment for painful arthritis affecting the joint. However, the complication rate is relatively high, with many of these complications related to soft-tissue imbalance or instability. Volar, dorsal, and lateral approaches have all been described with varying results. We describe a new simplified lateral hinge approach that splits the collateral ligament to provide adequate exposure of the joint. Following insertion of the prosthesis the collateral ligament is simply repaired, side-to-side, which stabilizes the joint. As the central slip, opposite collateral ligament, flexor and extensor tendons have not been violated, early active mobilization without splinting is possible, and the risk of instability, swan-neck, and boutonniere deformity are reduced. The indications, contraindications, surgical technique, and rehabilitation protocol are described. PMID:26230632

  12. A Simplified Lateral Hinge Approach to the Proximal Interphalangeal Joint.

    PubMed

    Bain, Gregory I; McGuire, Duncan T; McGrath, Aleksandra M

    2015-09-01

    Proximal interphalangeal joint replacement is an effective treatment for painful arthritis affecting the joint. However, the complication rate is relatively high, with many of these complications related to soft-tissue imbalance or instability. Volar, dorsal, and lateral approaches have all been described with varying results. We describe a new simplified lateral hinge approach that splits the collateral ligament to provide adequate exposure of the joint. Following insertion of the prosthesis the collateral ligament is simply repaired, side-to-side, which stabilizes the joint. As the central slip, opposite collateral ligament, flexor and extensor tendons have not been violated, early active mobilization without splinting is possible, and the risk of instability, swan-neck, and boutonniere deformity are reduced. The indications, contraindications, surgical technique, and rehabilitation protocol are described.

  13. Real-time inversions for finite fault slip models and rupture geometry based on high-rate GPS data

    USGS Publications Warehouse

    Minson, Sarah E.; Murray, Jessica R.; Langbein, John O.; Gomberg, Joan S.

    2015-01-01

    We present an inversion strategy capable of using real-time high-rate GPS data to simultaneously solve for a distributed slip model and fault geometry in real time as a rupture unfolds. We employ Bayesian inference to find the optimal fault geometry and the distribution of possible slip models for that geometry using a simple analytical solution. By adopting an analytical Bayesian approach, we can solve this complex inversion problem (including calculating the uncertainties on our results) in real time. Furthermore, since the joint inversion for distributed slip and fault geometry can be computed in real time, the time required to obtain a source model of the earthquake does not depend on the computational cost. Instead, the time required is controlled by the duration of the rupture and the time required for information to propagate from the source to the receivers. We apply our modeling approach, called Bayesian Evidence-based Fault Orientation and Real-time Earthquake Slip, to the 2011 Tohoku-oki earthquake, 2003 Tokachi-oki earthquake, and a simulated Hayward fault earthquake. In all three cases, the inversion recovers the magnitude, spatial distribution of slip, and fault geometry in real time. Since our inversion relies on static offsets estimated from real-time high-rate GPS data, we also present performance tests of various approaches to estimating quasi-static offsets in real time. We find that the raw high-rate time series are the best data to use for determining the moment magnitude of the event, but slightly smoothing the raw time series helps stabilize the inversion for fault geometry.

  14. From frictional fingers to stick slip bubbles

    NASA Astrophysics Data System (ADS)

    Sandnes, Bjørnar; Jørgen Måløy, Knut; Flekkøy, Eirik; Eriksen, Jon

    2014-05-01

    Gas intrusion into wet porous/deformable/granular media occurs in a wide range of natural and engineered settings. Examples include hydrocarbon recovery, carbon dioxide geo-sequestration, gas venting in sediments and volcanic eruptions. In the case where the intruding gas is able to displace particles and grains, local changes in granular packing fraction govern the evolution of flow paths, resulting in complex pattern formation of the displacement flow. Here we investigate flow patterning as a compressed gas displaces a granular mixture confined in the narrow gap of a Hele-Shaw cell. We find a surprising variety of different pattern formation dynamics, and present a unified phase diagram of the flow morphologies we observe. This talk will focus on one particular transition the system undergoes: from frictional fingers to stick slip bubbles. We show that the frictional fluid flow patterns depend on granular mass loading and system elasticity, analogous to the behaviour of the well-known spring-block sliding friction problem.

  15. Slip Distribution of the 2011 Tohoku-oki Earthquake obtained by Geodetic and Tsunami Data and with a 3-D Finite Element Model

    NASA Astrophysics Data System (ADS)

    Romano, F.; Trasatti, E.; Lorito, S.; Ito, Y.; Piatanesi, A.; Lanucara, P.; Hirata, K.; D'Agostino, N.; Cocco, M.

    2012-12-01

    The rupture process of the Great 2011 Tohoku-oki earthquake has been particularly well studied by using an unprecedented collection of geophysical data. There is a general agreement among the different source models obtained by modeling seismological, geodetic and tsunami data. A slip patch of nearly 40÷50 meters has been imaged and located around and up-dip from the hypocenter by most of published models, while some differences exist in the slip pattern retrieved at shallow depths near the trench, likely due to the different resolving power of distinct data sets and to the adopted fault geometry. It is well known that the modeling of great subduction earthquakes requires the use of 3-D structural models in order to properly account for the effects of topography, bathymetry and the geometrical variations of the plate interface as well as for the effects of elastic contrasts between the subducting plate and the continental lithosphere. In this study we build a 3-D Finite Element (FE) model of the Tohoku-oki area in order to infer the slip distribution of the 2011 earthquake by performing a joint inversion of geodetic (GPS and seafloor observations) and tsunami (ocean bottom pressure sensors, DART and GPS buoys) data. The FE model is used to compute the geodetic and tsunami Green's functions. In order to understand how geometrical and elastic heterogeneities control the inferred slip distribution of the Tohoku-oki earthquake, we compare the slip patterns obtained using both homogeneous and heterogeneous structural models. The goal of this study is to better constrain the slip distribution and the maximum slip amplitudes. In particular, we aim to focus on the rupture process in the shallower part of the fault plane and near the trench, which is crucial to model the tsunami data and to assess the tsunamigenic potential of earthquakes in this region.

  16. The Slip History and Source Statistics of Major Slow Slip Events along the Cascadia Subduction Zone from 1998 to 2008

    NASA Astrophysics Data System (ADS)

    Gao, H.; Schmidt, D. A.

    2008-12-01

    We estimate the time dependent slip distribution of 16 prominent slow slip events along the northern half of the Cascadia subduction zone from 1998 to 2008. We process continuous GPS data from the PBO, PANGA and WCDA networks from the past decade using GAMIT/GLOBK processing package. Transient surface displacements are interpreted as slip on the plate interface using the Extended Network Inversion Filter. Of these 16 events, 10 events are centered north of Puget Sound, 4 events are resolved around the Columbia River and 1 event is located near Cape Blanco. The February 2003 event is complex, extending from Portland to southern Vancouver Island. Other smaller events beneath Northern Vancouver Island, Oregon and Northern California are not well resolved because of the limited station coverage. We identify two characteristic segments based on the along-strike extent of individual transient slip events in northern Washington. One segment is centered around Port Angeles. Another segment is between the Columbia River and the southern end of Puget Sound. The propagation direction of slow slip events is variable from one event to the next. The maximum cumulative slip for these 16 events is ~ 27 cm, which is centered beneath Port Angeles. This indicates that the strain release by transient slip is not uniform along-strike. In northwestern Washington where cumulative slip is a maximum, the subduction zone bends along-strike and dip of the plate is lower compared to the north and south. We hypothesize that the geometry of the slab plays an important role for focusing transient strain release at this location along the subduction zone. We explore the relationship of source parameters of slow slip using our catalogue of 16 events. The estimated moment magnitude ranges between 6.1 and 6.7. The average stress drop of 0.06-0.1 MPa is nearly two orders of magnitude smaller than that found for normal earthquakes (1-10 MPa). Standard earthquakes follow a scaling relationship where

  17. Independence of slip velocities on applied stress in small crystals.

    PubMed

    Maaß, R; Derlet, P M; Greer, J R

    2015-01-21

    Directly tracing the spatiotemporal dynamics of intermittent plasticity at the micro- and nanoscale reveals that the obtained slip dynamics are independent of applied stress over a range of up to ∼400 MPa, as well as being independent of plastic strain. Whilst this insensitivity to applied stress is unexpected for dislocation plasticity, the stress integrated statistical properties of both the slip size magnitude and the slip velocity follow known theoretical predictions for dislocation plasticity. Based on these findings, a link between the crystallographic slip velocities and an underlying dislocation avalanche velocity is proposed. Supporting dislocation dynamics simulations exhibit a similar regime during microplastic flow, where the mean dislocation velocity is insensitive to the applied stress. Combining both experimental and modeling observations, the results are discussed in a framework that firmly places the plasticity of nano- and micropillars in the microplastic regime of bulk crystals.

  18. GENERAL ELECTRIC SYNCHRONOUS MOTOR, SLIP RING END. NOTE THAT OUTSIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GENERAL ELECTRIC SYNCHRONOUS MOTOR, SLIP RING END. NOTE THAT OUTSIDE FRAME IS ROTATING ARMATURE, AND STATOR IS IN CENTER. ARCH SUPPORTS BRAKE BAND. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  19. View from water showing south facade and adjacent boat slips ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from water showing south facade and adjacent boat slips (Facility Nos. S375 & S376) - U.S. Naval Base, Pearl Harbor, Boat House, Hornet Avenue at Independence Street, Pearl City, Honolulu County, HI

  20. 23. View looking N with former Brooklyn ferry slip in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. View looking N with former Brooklyn ferry slip in foreground. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  1. Slip ring experience in long duration space applications

    NASA Technical Reports Server (NTRS)

    Phinney, Damon D.

    1986-01-01

    Ball Aerospace experience with slip rings in space extends back to 1962. Over 40 multi-ring assemblies have been flown and continuous operating lifetimes greater than 8 years at up to 60 rpm have been demonstrated. Slip rings provide multi-channel transfer of electrical power and signals in assemblies that are small in size and weight, and low in cost. By use of multiple brushes and sufficient copper within the assembly, power transfer efficiency better than 99.95 percent for high voltage circuits can be achieved. A low slip ring failure rate based on actual space operation totalling billions of ring revolutions has been established. Well qualified suppliers who have been making slip rings for space use for over 25 years are available. It is hoped that the suspected problem in SEASAT will not be allowed to prejudice space system designer against these very useful mechanisms.

  2. Multilayer Coextrusion Reveals Slip at Polymer-polymer Interfaces

    NASA Astrophysics Data System (ADS)

    Zhao, Rui; Macosko, Christopher W.

    2000-03-01

    De Gennes (1992) suggested that loss of entanglement in the interfacial region between two incompatible polymers causes slip at interfaces. Goveas and Fredrickson (1998) developed a quantitative model for the lowering of interfacial viscosity. However, to date there appears to be no quantitative experimental evidence for interfacial slip. We coextruded polypropylene and polystyrene with closely matched viscosities into multilayers with 2,32 and 128 layers. Pressure drop of the coextruded multilayer melts through a slit die was measured. The data showed a 40reduction when the number of layers increased from 2 to 128, which indicates interfacial slip. The steady shear viscosity of the multilayer sample was also measured in parallel plates. When the shear stress was higher than a critical value, the viscosity of the multilayers was lower than either of the components. The interfacial viscosity was estimated, and 40 times reduction was observed. Diblock copolymer which spanned the interfaces was shown to able to suppress interfacial slip.

  3. Experimental Characterization of a Flexible Thermal Slip Sensor

    PubMed Central

    Francomano, Maria Teresa; Accoto, Dino; Guglielmelli, Eugenio

    2012-01-01

    Tactile sensors are needed for effectively controlling the interaction between a robotic hand and the environment, e.g., during manipulation of objects, or for the tactile exploration of unstructured environments, especially when other sensing modalities, such as vision or audition, become ineffective. In the case of hand prostheses, mainly intended for dexterous manipulation of daily living objects, the possibility of quickly detecting slip occurrence, thus avoiding inadvertent falling of the objects, is prodromal to any manipulation task. In this paper we report on a slip sensor with no-moving parts, based on thermo-electrical phenomena, fabricated on a flexible substrate and suitable for integration on curved surfaces, such as robotic finger pads. Experiments performed using a custom made test bench, which is capable of generating controlled slip velocities, show that the sensor detects slip events in less than 50 ms. This response time is short enough for enabling future applications in the field of hand prosthetics. PMID:23202209

  4. TV Ratings for Parents Let Violence, Drinking Slip Through

    MedlinePlus

    ... fullstory_160553.html TV Ratings for Parents Let Violence, Drinking Slip Through Industry guidelines often misleading, study ... don't always reflect the true amount of violence, smoking and drinking in TV shows, a new ...

  5. Surface fractionation effects on slip of polydisperse polymer melts

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Marzieh; Ansari, Mahmoud; Inn, Yong W.; Hatzikiriakos, Savvas G.

    2016-09-01

    The slip behavior of several high-density polyethylenes with broad range of molecular weight (MW) including bimodals is studied as a function of molecular weight (MW) and its distribution. A formulation similar to the double reptation theory is used to predict the slip velocity of the studied polymers as a function of MWD coupled with a model of surface molecular weight fractionation. While surface fractionation has a minor effect on slip of narrow to moderate MWD polymers (particularly unimodal), its role is significant for broad bimodal MWD polymers. The entropy driven migration of short chains toward the die wall has a profound effect and should be considered in order to calculate the effective MWD on the boundary layer and thus the correct magnitude of wall slip.

  6. Relaxation in crystal plasticity with three active slip systems

    NASA Astrophysics Data System (ADS)

    Conti, Sergio; Dolzmann, Georg

    2016-09-01

    We study a variational model for finite crystal plasticity in the limit of rigid elasticity. We focus on the case of three distinct slip systems whose slip directions lie in one plane and are rotated by 120° with respect to each other, with linear self-hardening and infinite latent hardening, in the sense that each material point has to deform in single slip. Under these conditions, plastic deformation is accompanied by the formation of fine-scale structures, in which activity along the different slip systems localizes in different areas. The quasiconvex envelope of the energy density, which describes the macroscopic material behavior, is determined in a regime from small up to intermediate strains, and upper and lower bounds are provided for large strains. Finally sufficient conditions are given under which the lamination convex envelope of an extended-valued energy density is an upper bound for its quasiconvex envelope.

  7. Slip Updip of Tremor during the 2012 Cascadia ETS Event

    NASA Astrophysics Data System (ADS)

    Hall, K.; Houston, H.

    2014-12-01

    The interplay between tremor and slow slip during ETS has implications for the slip budget of the Cascadia subduction zone. In particular, it can constrain the downdip edge of the locked zone, which informs the hazard assessments for major cities including Seattle, Tacoma, and Vancouver. As shown by Houston (AGU abstract, 2012), slip inferred from GPS extended updip of the seismically-detected tremor in the 2010 M6.8 ETS event. Following the methods used on the 2010 ETS event, we used the PANGA GPS to measure the displacement vectors for 71 stations to analyze a large ETS event in 2012 that extended from Vancouver Island to Southern Washington. We implemented Principal Component Analysis to automatically select the direction and magnitude of the maximum displacement vector. We then inverted these GPS displacements for slip, using the Okada formulation of buried rectangular faults in a halfspace with a grid of 8 by 8 km subfaults based on the McCrory slab model. We performed inversions with either 0th or 2nd order Tikhonov regularization and found that over the 6 weeks of propagation, the 2012 ETS event released moment corresponding to M6.7, in three high-slip regions. We compared two different inversions, one where slip was allowed on a broad regional grid and a tremor-restricted inversion (TRI) where slip was restricted to grid locations where tremor had been detected in the 2012 ETS. We found that the TRI forced the slip to the updip edge of the grid where it reached above 10 cm, which is physically implausible given that this exceeds the slip that can accumulate in an inter-ETS time period. Additionally, the regional grid inversion indicates that 1 to 2 cm of slip occurred 10's of km updip of the western edge of tremor. This further supports the inference from the 2010 event that in northern Washington, the slow slip during an ETS event extends many kilometers updip of the western edge of tremor.

  8. Foreshocks during the nucleation of stick-slip instability

    USGS Publications Warehouse

    McLaskey, Gregory C.; Kilgore, Brian D.

    2013-01-01

    We report on laboratory experiments which investigate interactions between aseismic slip, stress changes, and seismicity on a critically stressed fault during the nucleation of stick-slip instability. We monitor quasi-static and dynamic changes in local shear stress and fault slip with arrays of gages deployed along a simulated strike-slip fault (2 m long and 0.4 m deep) in a saw cut sample of Sierra White granite. With 14 piezoelectric sensors, we simultaneously monitor seismic signals produced during the nucleation phase and subsequent dynamic rupture. We observe localized aseismic fault slip in an approximately meter-sized zone in the center of the fault, while the ends of the fault remain locked. Clusters of high-frequency foreshocks (Mw ~ −6.5 to −5.0) can occur in this slowly slipping zone 5–50 ms prior to the initiation of dynamic rupture; their occurrence appears to be dependent on the rate at which local shear stress is applied to the fault. The meter-sized nucleation zone is generally consistent with theoretical estimates, but source radii of the foreshocks (2 to 70 mm) are 1 to 2 orders of magnitude smaller than the theoretical minimum length scale over which earthquake nucleation can occur. We propose that frictional stability and the transition between seismic and aseismic slip are modulated by local stressing rate and that fault sections, which would typically slip aseismically, may radiate seismic waves if they are rapidly stressed. Fault behavior of this type may provide physical insight into the mechanics of foreshocks, tremor, repeating earthquake sequences, and a minimum earthquake source dimension.

  9. Modelling Paleoearthquake Slip Distributions using a Gentic Algorithm

    NASA Astrophysics Data System (ADS)

    Lindsay, Anthony; Simão, Nuno; McCloskey, John; Nalbant, Suleyman; Murphy, Shane; Bhloscaidh, Mairead Nic

    2013-04-01

    Along the Sunda trench, the annual growth rings of coral microatolls store long term records of tectonic deformation. Spread over large areas of an active megathrust fault, they offer the possibility of high resolution reconstructions of slip for a number of paleo-earthquakes. These data are complex with spatial and temporal variations in uncertainty. Rather than assuming that any one model will uniquely fit the data, Monte Carlo Slip Estimation (MCSE) modelling produces a catalogue of possible models for each event. From each earthquake's catalogue, a model is selected and a possible history of slip along the fault reconstructed. By generating multiple histories, then finding the average slip during each earthquake, a probabilistic history of slip along the fault can be generated and areas that may have a large slip deficit identified. However, the MCSE technique requires the production of many hundreds of billions of models to yield the few models that fit the observed coral data. In an attempt to accelerate this process, we have designed a Genetic Algorithm (GA). The GA uses evolutionary operators to recombine the information held by a population of possible slip models to produce a set of new models, based on how well they reproduce a set of coral deformation data. Repeated iterations of the algorithm produce populations of improved models, each generation better satisfying the coral data. Preliminary results have shown the GA to be capable of recovering synthetically generated slip distributions based their displacements of sets of corals faster than the MCSE technique. The results of the systematic testing of the GA technique and its performance using both synthetic and observed coral displacement data will be presented.

  10. Refining the Magnitude of the Shallow Slip Deficit

    NASA Astrophysics Data System (ADS)

    Xu, X.; Tong, X.; Sandwell, D. T.; Milliner, C. W. D.

    2014-12-01

    Geodetic inversions for slip versus depth for several major (Mw > 7) strike-slip earthquakes (e.g. 1992 Landers, 1999 Hector Mine, 2010 El_Mayor-Cucapah) show a 10% to 40% reduction in slip near surface (depth < 2 km) compared to the slip at deeper depths (5 to 8 km). This has been called the shallow slip deficit (SSD). The large magnitude of this deficit has been an enigma since it cannot be explained by shallow creep during the interseismic period or by triggered slip from nearby earthquakes. One potential explanation for the SSD is that the previous geodetic inversions used incomplete data that do not go close to fault so the shallow portions of the slip models were poorly resolved and generally underestimated. In this study we improve the geodetic inversion, especially at shallow depth by: 1) refining the InSAR processing with non-boxcar phase filtering, model-dependent range corrections, more complete phase unwrapping by SNAPHU using a correlation mask and allowing a phase discontinuity along the rupture; 2) including near-fault offset data from optical imagery and SAR azimuth offsets; 3) using more detailed fault geometry; 4) and using additional campaign GPS data. With these improved observations, the slip inversion has significantly increased resolution at shallow depth. For the Landers rupture the SSD is reduced from 45% to 16%. Similarly for the Hector Mine rupture the SSD is reduced from 15% to 5%. We are assembling all the relevant co-seismic data for the El Major-Cucapah earthquake and will report the inversion result with its SSD at the meeting.

  11. Wheel rolling constraints and slip in mobile robots

    SciTech Connect

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  12. Wheel rolling constraints and slip in mobile robots

    SciTech Connect

    Shekhar, S.

    1996-06-01

    It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  13. Fault slip during a glacial cycle

    NASA Astrophysics Data System (ADS)

    Steffen, Rebekka; Wu, Patrick; Steffen, Holger; Eaton, Dave

    2013-04-01

    Areas affected by glacial isostatic adjustment (GIA) generally show uplift after deglaciation. These regions are also characterized by a moderate past and present-day seismicity, at seismic moment release rates that exceed those expected under stable tectonic conditions. Several faults have been found in North America and Europe, which have been activated during or after the last deglaciation. Large-magnitude earthquakes have generated fault offsets of up to 120 m. Due to the recent melting of Greenland and Antarctic ice sheets, an understanding of the occurrence of these earthquakes is important. With a new finite-element model, we are able to estimate, for the first time, fault slip during a glacial cycle for continental ice sheets. A two-dimensional earth model based on former GIA studies is developed, which is loaded with a hyperbolic ice sheet. The fault is able to move in a stress field consisting of rebound stress, tectonic background stress, and lithostatic stress. The sensitivity of this fault is tested regarding lithospheric and crustal thickness, viscosity structure of upper and lower mantle, ice-sheet thickness and width, and fault parameters including coefficient of friction, depth, angle and location. Fault throws of up to 30 m are obtained using a fault of 45° dipping below the ice sheet centre. The thickness of the crust is one of the major parameters affecting the total fault throw, e.g. higher values for a thinner crust. Most faults start to move close to the end of deglaciation, and movement stops after one thrusting/reverse earthquake. However, certain conditions may also lead to several fault movements after the end of glaciations.

  14. Geometry, kinematics and slip rate along the Mosha active fault, Central Alborz, Iran

    NASA Astrophysics Data System (ADS)

    Ritz, J.-F.; Pics Geological Team

    2003-04-01

    The Mosha fault is one of the major active fault in Central Alborz as shown by its strong historical seismicity and its clear morphological signature. Situated at the vicinity of Tehran city, this ~150 km long ~N100°E trending fault represents an important potential seismic source that threatens the Iranian metropolis. In the framework of an Iranian-French joint research program (PICS) devoted to seismic hazard assessment in the Tehran region, we undertook a morphotectonic (determination of the cumulative displacements and the ages of offset morphologic markers) and paleoseismic (determination of the ages and magnitudes of ancient events) study along the Mosha fault. Our objectives are the estimation of the long-term slip rate (Upper Pleistocene-Holocene) and the mean recurrence interval of earthquakes along the different segments of the fault. Our investigations within the Tar Lake valley, along the eastern part of the fault potentially the site of the 1665 (VII, 6.5) historical earthquake - allows us to calculate a preliminary 2 ± 0.1 mm/yr minimum left lateral slip rate. If we assume a characteristic coseismic average displacement comprised between 0.35 m (Mw 6.5) and 1.2 m (Mw 7.1) calculated from Wells &Coppersmith’s functions (1994) and taking the moment magnitudes attributed to the 1665 and 1830 earthquakes (e.g. Berberian &Yeats, 2001) the mean maximum recurrence intervals along this segment of the Mosha fault are comprised between 160 and 620 yrs.

  15. Intersegmental coordination elicited by unexpected multidirectional slipping-like perturbations resembles that adopted during steady locomotion.

    PubMed

    Aprigliano, Federica; Martelli, Dario; Micera, Silvestro; Monaco, Vito

    2016-02-01

    This study aimed at testing the hypothesis that reactive biomechanical responses elicited by unexpected slipping-like perturbations delivered during steady walking are characterized by an intersegmental coordination strategy resembling that adopted during unperturbed walking. Fifteen healthy subjects were asked to manage multidirectional slipping-like perturbations delivered while they walked steadily. The planar covariation law of elevation angles related to lower limb segments was the main observed variable related to unperturbed and perturbed strides. Principal component analysis was used to verify whether elevation angles covaried, both before and after the onset of the perturbation, and, if so, the orientation of the related planes of covariation was compared. Results revealed that the planar covariation law of the unperturbed limb after onset of the perturbation was systematically similar to that seen during steady walking. This occurred despite differences in range of motion and intersubject variability of both elevation and joint angles. The analysis strongly corroborates the hypothesis that the planar covariation law emerges from the interaction between spinal neural networks and limb mechanical oscillators. In particular, fast and stereotyped reactive strategies may result from the interaction among activities of downstream neural networks encrypting well-trained motor schemes, such as those related to walking, limb dynamics, and sensory motor information gathered during the perturbation. In addition, our results allowed us to speculate that rehabilitative treatment based on unexpected perturbations and relying on the plasticity of the central nervous system may also be effective in eliciting unimpaired intralimb coordination in neurological patients.

  16. Predicting apparent slip at liquid-liquid interfaces without an interface slip condition

    NASA Astrophysics Data System (ADS)

    Poesio, Pietro; Damone, Angelo; Matar, Omar

    2015-11-01

    We show that if we include a density-dependent viscosity into the Navier-Stokes equations then we can describe, naturally, the velocity profile in the interfacial region, as we transition from one fluid to another. This requires knowledge of the density distribution (for instance, via Molecular Dynamics [MD] simulations, a diffuse-interface approach, or Density Functional Theory) everywhere in the fluids, even at liquid-liquid interfaces where regions of rapid density variations are possible due to molecular interactions. We therefore do not need an artificial interface condition that describes the apparent velocity slip. If the results are compared with the computations obtained from MD simulations, we find an almost perfect agreement. The main contribution of this work is to provide a simple way to account for the apparent slip at liquid-liquid interfaces without relying upon an additional boundary condition, which needs to be calculated separately using MD simulations. Examples are provided involving two immiscible fluids of varying average density ratios, undergoing simple Couette and Poisseuille flows. MIUR through PRIN2012-NANOBridge; Royal Society International Exchange Scheme (IE141486).

  17. Surface mobility and slip of polybutadiene melts in shear flow

    SciTech Connect

    Wise, Geoffrey M.; Denn, Morton M.; Bell, Alexis T.; Mays, Jimmy W.; Hong, Kunlun; Iatrou, Hermis

    2000-05-01

    Surface mobility and wall slip of entangled polybutadiene melts were studied with attenuated-total-reflectance infrared spectroscopy at stresses characteristic of the sharkskin, spurt, and melt-fracture regimes. Small-scale slip, accompanied by an apparent decrease in transverse mobility, occurs in the sharkskin regime, but at a stress above the visual onset of sharkskin in capillary viscometry. Simulations cannot distinguish between a cohesive mechanism and a lubrication mechanism that might follow from a stress-induced phase transition, but an adhesive failure seems to be excluded. The near-surface length scale is of the order of four to six times the equilibrium root-mean-square end-to-end distance, and the estimated slip velocity is insensitive to molecular weight. Strong slip occurs in the spurt regime, either at the wall or within one radius of gyration. Substantial apparent slip occurs with a fluorocarbon surface, but the mechanism does not appear to be an adhesive failure; there seems to be a substantial decrease in the friction coefficient of chains over a distance of order 300 nm or more from the fluorocarbon surface, and the transverse chain mobility in this region appears to be enhanced rather than retarded. Overall, the results of this study indicate that the influence of the wall extends farther into the sheared melt than would be expected from the chain dimensions, except in the case of strong slip. (c) 2000 Society of Rheology.

  18. Biomechanical response to ladder slipping events: Effects of hand placement.

    PubMed

    Schnorenberg, Alyssa J; Campbell-Kyureghyan, Naira H; Beschorner, Kurt E

    2015-11-01

    Ladder falling accidents are a significant, growing and severe occupational hazard. The factors that contribute to falls from ladders and specifically those that influence the motor response from ladder falls are not well understood. The aims of this research were to determine the effects of hand placement (rung versus rail) on muscle activation onset and peak activity timing in response to slipping on a ladder and to sequence the timing of events following slip initiation. Fifteen unexpected slips from 11 experienced ladder climbers were induced with a freely spinning rung under the foot, while subjects were randomly assigned to a rung versus rail hand grasping strategy. EMG onset time and peak activity time from five bilateral muscles (semitendinosis, vastus lateralis, triceps, biceps and anterior deltoid) were analyzed. Results indicated that significantly slower muscle activation onset and peak response times occurred during rail hand placement, suggesting that grasping ladder rungs may be preferable for improving the speed of the motor response. The triceps muscle activated and reached peak activity earlier in the slip indicating that subjects may initially extend their arms prior to generating hand forces. The study also revealed that slips tended to occur around the time that a foot and hand were in motion and there were just two points of contact (one hand and the slipping foot).

  19. Texture and pyramidal slip in Ti, Zr and their alloys

    SciTech Connect

    Pochettino, A.A.; Gannio, N. ); Edwards, C.V. ); Penelle, R. )

    1992-12-15

    Zirconium, titanium and their alloys have a high anisotropic plastic behavior. One way to show this behavior is to analyze the evolution of the Lankford coefficient (R ([alpha]), values of which are obtained from tensile tests along different directions in the sheet plane). The variation of R([alpha]) can be explained from the crystallographic texture and the active deformation mechanisms. Microstructural observations show that prismatic slip is the most active deformation mode in these materials, but no dimensional change in the [lt][bar c][gt] direction of grains is possible by the activation of the (10[bar 1]0) [lt] 1[bar 2]10[gt] slip alone; so deformation along [0001] has to be accommodated either by (10[bar 1]o) [lt]1[bar 2]13[gt] (or [lt][bar c] + [bar a][gt]) pyramidal slip or by twinning. Many transmission electron microscopy (TEM) studies have shown evidence for [lt][bar c] + [bar a][gt] slip activity, and some authors have reported slip on (1[bar 1]01) planes in Ti alloys. The purpose of this paper is to contribute with another analysis of pyramidal slip activity in hcp textured materials, such as Ti and Zr alloys, and of the hardening mechanisms for this deformation mode. This analysis is performed both in a direct way, by means of TEM observations of deformed samples, and in an indirect way, by different mechanical tests.

  20. Effects of slipping-like perturbation intensity on the dynamical stability.

    PubMed

    Aprigliano, Federica; Martelli, Dario; Tropea, Peppino; Micera, Silvestro; Monaco, Vito

    2015-01-01

    Falls are a major cause of morbidity and death in elderly people. Understanding how subjects maintain stability while walking or while being exposed to perturbations is important in order to prevent falls. Here, five healthy subjects were asked to manage unexpected slipping-like perturbations of increasing intensities (i.e., soft, medium and strong) in order to investigate the effects of the perturbation intensity on the biomechanical behavior and on the dynamical stability, described by the Margin of Stability. The lower limb kinematic (i.e., hip, knee and ankle joints angles) was computed before and after the onset of the perturbation. The compensatory time and the Margin of Stability were calculated after the onset of the perturbation. As expected, results showed that the perturbation altered the subjects' kinematic and the modulation of the perturbation intensity was reflected in the dynamical stability: the stronger was the perturbation, the lower was the Margin of Stability describing a lower balance recovery.

  1. Slip zone structure and processes in seismogenic carbonate faults

    NASA Astrophysics Data System (ADS)

    Bullock, R. J.; De Paola, N.

    2011-12-01

    High velocity rotary shear experiments performed at seismic slip velocities (>1 m/s) have shown that experimental faults are weak; with increasing displacement, friction coefficient values decrease from Byerlee's values (μ = 0.6-0.85) to values of ~0.1. In carbonate rocks, experimental studies have shown that fault lubrication is due to the operation of multiple dynamic weakening mechanisms (e.g., flash heating, thermal pressurization, nanoparticle lubrication), which are thermally activated due to the frictional heat generated along localized slip surfaces during rapid slip. This study has set out to investigate whether evidence for the operation of these weakening mechanisms can be found in naturally occurring carbonate fault zones. Field studies were carried out on the active Gubbio fault zone (1984, Mw = 5.6) in the northern Apennines of Italy. Jurassic-Oligocene carbonates in the footwall are heavily deformed within a fault core of ~15 m thickness, which contains a number of very well exposed, highly localized principal slip surfaces (PSSs). Fault rocks are predominantly breccias and foliated cataclasites. Microstructural analyses of the PSSs reveal that slip is localized within very narrow principal slip zones (PSZs), ranging from 10-85 μm in thickness, with sub-millimetre scale asperities. PSZs are composed of very fine-grained, orange-brown ultracataclasite gouge containing a high proportion of nano-sized particles. The ultracataclasite commonly displays a foliated texture and sub-micron scale zones of extreme shear localization. A broader slip zone, up to 1.5 mm wide and containing multiple slip surfaces, is associated with the most evolved PSSs; it is located on the opposite side of the PSS to the PSZ. Here, the host rock material is heavily fractured, abraded and altered, sometimes with an ultracataclasite matrix. The surrounding wall rock often appears to have a porous texture, and calcite crystals within the slip zone have altered rims with lobate

  2. Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis

    PubMed Central

    Klit, Jakob; Gosvig, Kasper; Magnussen, Erland; Gelineck, John; Kallemose, Thomas; Søballe, Kjeld; Troelsen, Anders

    2014-01-01

    Background and purpose — Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE). Methods — We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10–17 years postoperatively. Median age at surgery was 12 (10–14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up. Results — Median preoperative Southwick angle was 22o (IQR: 12–27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade > 1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49–56) and median mental score was 56 (IQR: 54–58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution. Median WOMAC score was 100 (IQR: 84–100). Interpretation — In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise. PMID:25175666

  3. Effects of Tidal Modulation in Heterogeneous Models of Slow Slip

    NASA Astrophysics Data System (ADS)

    Skarbek, R. M.; Rempel, A. W.; Thomas, A.

    2014-12-01

    Since their discovery, numerous models have been put forward to explain the occurance of slow slip and associated tremor. These models invoke a wide array of causal mechanisms and are all successful in reproducing the first-order behavior of slow-slip events. Discriminating amongst the various proposed models requires looking at second-order effects of slow slip and tremor. Here, we consider the effects of tidal modulation on slow slip in subduction zones. A great deal of observational evidence has established that slow-slip and associated tremor are modulated by the small stress perturbations associated with tides and teleseismic events. Recent modeling studies that have examined the influence of tidal stresses (<10 kPa) have focused either on the effects of tidally induced changes in shear stress, or on changes in shear and normal stress that coincide. However, along the Cascadia margin, the relative phase of the tidally induced fault-normal and shear stresses depends on position along the plate boundary fault, and can vary from being in phase, to completely out of phase. We report on the predictions of models designed to examine the sensitivity of slow-slip in subduction zones to the phase shift γ between tidally induced normal and shear stress perturbations. We consider both simple spring-slider and 1-D elastodynamic models that are designed to mimic the effects of geologic heterogeneity by allowing for variations in the rate-and-state frictional parameters. For a given slow-slip event, spring-slider results indicate that the phase lag γv between the peak slip rate and the tidally induced shear stress perturbation depends on both the phase shift γ, and the perturbation amplitude. Models parameterized for Cascadia are capable of producing phase lags γv within the range (15◦ to 30◦) of those reported by Royer et al. (JGR, 2014). Additionally, our models predict that the correlation between tidally induced shear stress perturbations and resultant slip also

  4. Polydimethylsiloxane SlipChip for mammalian cell culture applications.

    PubMed

    Chang, Chia-Wen; Peng, Chien-Chung; Liao, Wei-Hao; Tung, Yi-Chung

    2015-11-01

    This paper reports a polydimethylsiloxane (PDMS) SlipChip for in vitro cell culture applications, multiple-treatment assays, cell co-cultures, and cytokine detection assays. The PDMS SlipChip is composed of two PDMS layers with microfluidic channels on each surface that are separated by a thin silicone fluid (Si-fluid) layer. The integration of Si-fluid enables the two PDMS layers to be slid to different positions; therefore, the channel patterns can be re-arranged for various applications. The SlipChip design significantly reduces the complexity of sample handling, transportation, and treatment processes. To apply the developed SlipChip for cell culture applications, human lung adenocarcinoma epithelial cells (A549) and lung fibroblasts (MRC-5) were cultured to examine the biocompatibility of the developed PDMS SlipChip. Moreover, embryonic pluripotent stem cells (ES-D3) were also cultured in the device to evaluate the retention of their stemness in the device. The experimental results show that cell morphology, viability and proliferation are not affected when the cells are cultured in the SlipChip, indicating that the device is highly compatible with mammalian cell culture. In addition, the stemness of the ES-D3 cells was highly retained after they were cultured in the device, suggesting the feasibility of using the SlipChip for stem cell research. Various cell experiments, such as simultaneous triple staining of cells and co-culture of MRC-5 with A549 cells, were also performed to demonstrate the functionalities of the PDMS SlipChip. Furthermore, we used a cytokine detection assay to evaluate the effect of endotoxin (lipopolysaccharides, LPS) treatment on the cytokine secretion of A549 cells using the SlipChip. The developed PDMS SlipChip provides a straightforward and effective platform for various on-chip in vitro cell cultures and consequent analysis, which is promising for a number of cell biology studies and biomedical applications. PMID:26381390

  5. Quantitative analysis of fault slip evolution in analogue transpression models

    NASA Astrophysics Data System (ADS)

    Leever, Karen; Gabrielsen, Roy H.; Schmid, Dani; Braathen, Alvar

    2010-05-01

    A quantitative analysis of fault slip evolution in crustal scale brittle and brittle-ductile analogue models of doubly vergent transpressional wedges was performed by means of Particle Image Velocimetry (PIV). The kinematic analyses allow detailed comparison between model results and field kinematic data. This novel approach leads to better understanding of the evolution of transpressional orogens such as the Tertiary West Spitsbergen fold and thrust belt in particular and will advance the understanding of transpressional wedge mechanics in general. We ran a series of basal-driven models with convergence angles of 4, 7.5, 15 and 30 degrees. In these crustal scale models, brittle rheology was represented by quartz sand; in one model a viscous PDMS layer was included at shallow depth. Total sand pack thickness was 6cm, its extent 120x60cm. The PIV method was used to calculate a vector field from pairs of images that were recorded from the top of the experiments at a 2mm displacement increment. The slip azimuth on discrete faults was calculated and visualized by means of a directional derivative of this vector field. From this data set, several stages in the evolution of the models could be identified. The stages were defined by changes in the degree of displacement partitioning, i.e. slip along-strike and orthogonal to the plate boundary. A first stage of distributed strain (with no visible faults at the model surface) was followed by a shear lens stage with oblique displacement on pro- and retro-shear. The oblique displacement became locally partitioned during progressive displacement. During the final stage, strain was more fully partitioned between a newly formed central strike slip zone and reverse faults at the sides. Strain partitioning was best developed in the 15 degrees model, which shows near-reverse faults along both sides of the wedge in addition to strike slip displacement in the center. In further analysis we extracted average slip vectors for

  6. Effects of Perturbation-Based Slip Training using a Virtual Reality Environment on Slip-induced Falls

    PubMed Central

    Parijat, Prakriti; Lockhart, Thurmon E.; Liu, Jian

    2015-01-01

    The purpose of the current study was to design and evaluate the effectiveness of virtual reality training in improving recovery reactions and reducing fall frequency in older adults. Twenty-four older adults were recruited and randomly assigned to two groups (virtual reality training and control). Both groups underwent three sessions including baseline slip, training and transfer of training on slippery surface. Both groups experienced two slips, one during baseline and the other during the transfer of training trial. The training group underwent twelve simulated slips using a visual perturbation induced by tilting a virtual reality scene while walking on the treadmill and the control group performed normal walking during the training session. Kinematic and kinetic data were collected during all the sessions. Results demonstrated a reduced incidence of falls in the training group during the transfer of training trial as compared to the control group. The training group was able to transfer reactive control strategies learned during training to the second slip trial. The reactive adjustments included reduced slip distance. Additionally, gait parameters reflective of gait instability (stride length, step width, variability in stride velocity) reduced after walking in the VR environment for 15–20 min. The results indicated a beneficial effect of the virtual reality training in reducing slip severity and recovery kinematics in healthy older adults. PMID:25245221

  7. Regional Slip Tendency Analysis of the Great Basin Region

    DOE Data Explorer

    Faulds, James E.

    2013-09-30

    Slip and dilation tendency on the Great Basin fault surfaces (from the USGS Quaternary Fault Database) were calculated using 3DStress (software produced by Southwest Research Institute). Slip and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by the measured ambient stress field. - Values range from a maximum of 1 (a fault plane ideally oriented to slip or dilate under ambient stress conditions) to zero (a fault plane with no potential to slip or dilate). - Slip and dilation tendency values were calculated for each fault in the Great Basin. As dip is unknown for many faults in the USGS Quaternary Fault Database, we made these calculations using the dip for each fault that would yield the maximum slip or dilation tendency. As such, these results should be viewed as maximum slip and dilation tendency. - The resulting along‐fault and fault‐to‐fault variation in slip or dilation potential is a proxy for along fault and fault‐to‐fault variation in fluid flow conduit potential. Stress Magnitudes and directions were calculated across the entire Great Basin. Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson‐Tait et al., 2004; Hickman and Davatzes, 2010; Davatzes and Hickman, 2006; Blake and Davatzes 2011; Blake and Davatzes, 2012; Moeck et al., 2010; Moos and Ronne, 2010 and Reinecker et al., 2005). The minimum horizontal stress direction (Shmin) was contoured, and spatial bins with common Shmin directions were calculated. Based on this technique, we subdivided the Great Basin into nine regions (Shmin <070, 070140). Slip and dilation tendency were calculated using 3DStress for the faults within each region using the mean Shmin for the region. Shmin variation throughout Great Basin

  8. Reactivated strike slip faults: examples from north Cornwall, UK

    NASA Astrophysics Data System (ADS)

    Kim, Young-Seog; Andrews, Jim R.; Sanderson, David J.

    2001-10-01

    Several strike-slip faults at Crackington Haven, UK show evidence of right-lateral movement with tip cracks and dilatational jogs, which have been reactivated by left-lateral strike-slip movement. Evidence for reactivation includes two slickenside striae on a single fault surface, two groups of tip cracks with different orientations and very low displacement gradients or negative (left-lateral) displacements at fault tips. Evidence for the relative age of the two strike-slip movements is (1) the first formed tip cracks associated with right-lateral slip are deformed, whereas the tip cracks formed during left-lateral slip show no deformation; (2) some of the tip cracks associated with right-lateral movement show left-lateral reactivation; and (3) left-lateral displacement is commonly recorded at the tips of dominantly right-lateral faults. The orientation of the tip cracks to the main fault is 30-70° clockwise for right-lateral slip, and 20-40° counter-clockwise for left-lateral slip. The structure formed by this process of strike-slip reactivation is termed a "tree structure" because it is similar to a tree with branches. The angular difference between these two groups of tip cracks could be interpreted as due to different stress distribution (e.g., transtensional/transpressional, near-field or far-field stress), different fracture modes or fractures utilizing pre-existing planes of weakness. Most of the d- x profiles have similar patterns, which show low or negative displacement at the segment fault tips. Although the d- x profiles are complicated by fault segments and reactivation, they provide clear evidence for reactivation. Profiles that experienced two opposite slip movements show various shapes depending on the amount of displacement and the slip sequence. For a larger slip followed by a smaller slip with opposite sense, the profile would be expected to record very low or reverse displacement at fault tips due to late-stage tip propagation. Whereas for a

  9. Slip distribution, strain accumulation and aseismic slip on the Chaman Fault system

    NASA Astrophysics Data System (ADS)

    Amelug, F.

    2015-12-01

    The Chaman fault system is a transcurrent fault system developed due to the oblique convergence of the India and Eurasia plates in the western boundary of the India plate. To evaluate the contemporary rates of strain accumulation along and across the Chaman Fault system, we use 2003-2011 Envisat SAR imagery and InSAR time-series methods to obtain a ground velocity field in radar line-of-sight (LOS) direction. We correct the InSAR data for different sources of systematic biases including the phase unwrapping errors, local oscillator drift, topographic residuals and stratified tropospheric delay and evaluate the uncertainty due to the residual delay using time-series of MODIS observations of precipitable water vapor. The InSAR velocity field and modeling demonstrates the distribution of deformation across the Chaman fault system. In the central Chaman fault system, the InSAR velocity shows clear strain localization on the Chaman and Ghazaband faults and modeling suggests a total slip rate of ~24 mm/yr distributed on the two faults with rates of 8 and 16 mm/yr, respectively corresponding to the 80% of the total ~3 cm/yr plate motion between India and Eurasia at these latitudes and consistent with the kinematic models which have predicted a slip rate of ~17-24 mm/yr for the Chaman Fault. In the northern Chaman fault system (north of 30.5N), ~6 mm/yr of the relative plate motion is accommodated across Chaman fault. North of 30.5 N where the topographic expression of the Ghazaband fault vanishes, its slip does not transfer to the Chaman fault but rather distributes among different faults in the Kirthar range and Sulaiman lobe. Observed surface creep on the southern Chaman fault between Nushki and north of City of Chaman, indicates that the fault is partially locked, consistent with the recorded M<7 earthquakes in last century on this segment. The Chaman fault between north of the City of Chaman to North of Kabul, does not show an increase in the rate of strain

  10. Butt Joint Tool Commissioning

    SciTech Connect

    Martovetsky, N N

    2007-12-06

    ITER Central Solenoid uses butt joints for connecting the pancakes in the CS module. The principles of the butt joining of the CICC were developed by the JAPT during CSMC project. The difference between the CSMC butt joint and the CS butt joint is that the CS butt joint is an in-line joint, while the CSMC is a double joint through a hairpin jumper. The CS butt joint has to carry the hoop load. The straight length of the joint is only 320 mm, and the vacuum chamber around the joint has to have a split in the clamp shell. These requirements are challenging. Fig.1 presents a CSMC joint, and Fig.2 shows a CS butt joint. The butt joint procedure was verified and demonstrated. The tool is capable of achieving all specified parameters. The vacuum in the end was a little higher than the target, which is not critical and readily correctable. We consider, tentatively that the procedure is established. Unexpectedly, we discover significant temperature nonuniformity in the joint cross section, which is not formally a violation of the specs, but is a point of concern. All testing parameters are recorded for QA purposes. We plan to modify the butt joining tool to improve its convenience of operation and provide all features necessary for production of butt joints by qualified personnel.

  11. Slip Running Reconnection in Magnetic Flux Ropes

    NASA Astrophysics Data System (ADS)

    Gekelman, W. N.; Van Compernolle, B.; Vincena, S. T.; De Hass, T.

    2012-12-01

    Magnetic flux ropes are due to helical currents and form a dense carpet of arches on the surface of the sun. Occasionally one tears loose as a coronal mass ejection and its rope structure can be detected by satellites close to the earth. Current sheets can tear into filaments and these are nothing other than flux ropes. Ropes are not static, they exert mutual ěc{J}×ěc{B} forces causing them to twist about each other and eventually merge. Kink instabilities cause them to violently smash into each other and reconnect at the point of contact. We report on experiments on two adjacent ropes done in the large plasma device (LAPD) at UCLA ( ne ˜ 1012, Te ˜ 6 eV, B0z=330G, Brope}\\cong{10G,trep=1 Hz). The currents and magnetic fields form exotic shapes with no ignorable direction and no magnetic nulls. Volumetric space-time data (70,600 spatial locations) show multiple reconnection sites with time-dependent locations. The concept of a quasi-separatrix layer (QSL), a tool to understand and visualize 3D magnetic field lines reconnection without null points is introduced. Three-dimensional measurements of the QSL derived from magnetic field data are presented. Within the QSL field lines that start close to one another rapidly diverge as they pass through one or more reconnection regions. The motion of magnetic field lines are traced as reconnection proceeds and they are observed to slip through the regions of space where the QSL is largest. As the interaction proceeds we double the current in the ropes. This accompanied by intense heating as observed in uv light and plasma flows measured by Mach probes. The interaction of the ropes is clearly seen by vislaulizng magnetic field data , as well as in images from a fast framing camera. Work supported by the Dept. of Energy and The National Science Foundation, done at the Basic Plasma Science Facility at UCLA.Magnetic Field lines (measured) of three flux ropes and the plasma currents associated with them

  12. Slow slip and tremor search at Kilauea Volcano, Hawaii

    NASA Astrophysics Data System (ADS)

    Montgomery-Brown, E. K.; Thurber, C. H.; Wolfe, C. J.; Okubo, P.

    2013-02-01

    AbstractKilauea Volcano, Hawaii, has hosted a long series of slow <span class="hlt">slip</span> events observed since the installation of the continuous GPS network in 1996. Kilauea's slow <span class="hlt">slip</span> events are inferred to occur on the decollement fault at 8 km depth beneath its south flank, with a location updip of the epicenters of large, regular earthquakes. Fault <span class="hlt">slip</span> typically lasts about two days, and the events have magnitudes equivalent to Mw 5.3-6.0. While slow <span class="hlt">slip</span> events in subduction zones are commonly accompanied by tectonic tremor (also called nonvolcanic tremor), no tremor has yet been reported in association with Kilauea's slow <span class="hlt">slip</span> events. Instead, there are swarms of small triggered earthquakes, which is a characteristic only seen at select subduction zones (e.g., Boso and Hikurangi). A temporary array of seismometers was installed at Kilauea in 2007 in anticipation of a slow <span class="hlt">slip</span> event. Here we use several established methods to perform a systematic search for tectonic tremor during geodetically defined slow <span class="hlt">slip</span> events, as well as searching for tremor triggered by teleseismic surface waves. We do not detect tectonic tremor using any of these methods, although we are able to detect episodes of previously identified deep offshore volcanic tremor at 15-20 km depth and volcanic tremor from Kilauea. Although Kilauea's seismic network may not be adequate to observe tectonic tremor because Hawaii is seismically noisy and its crust is highly attenuating, it is also possible that the specific fault conditions on Kilauea's decollement are not conducive to such tremor generation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70014702','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70014702"><span id="translatedtitle">Nucleation and triggering of earthquake <span class="hlt">slip</span>: effect of periodic stresses</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dieterich, J.H.</p> <p>1987-01-01</p> <p>Results of stability analyses for spring and slider systems, with state variable constitutive properties, are applied to <span class="hlt">slip</span> on embedded fault patches. Unstable <span class="hlt">slip</span> may nucleate only if the <span class="hlt">slipping</span> patch exceeds some minimum size. Subsequent to the onset of instability the earthquake <span class="hlt">slip</span> may propagate well beyond the patch. It is proposed that the seismicity of a volume of the earth's crust is determined by the distribution of initial conditions on the population of fault patches that nucleate earthquake <span class="hlt">slip</span>, and the loading history acting upon the volume. Patches with constitutive properties inferred from laboratory experiments are characterized by an interval of self-driven accelerating <span class="hlt">slip</span> prior to instability, if initial stress exceeds a minimum threshold. This delayed instability of the patches provides an explanation for the occurrence of aftershocks and foreshocks including decay of earthquake rates by time-1. A population of patches subjected to loading with a periodic component results in periodic variation of the rate of occurrence of instabilities. The change of the rate of seismicity for a sinusoidal load is proportional to the amplitude of the periodic stress component and inversely proportional to both the normal stress acting on the fault patches and the constitutive parameter, A1, that controls the direct velocity dependence of fault <span class="hlt">slip</span>. Values of A1 representative of laboratory experiments indicate that in a homogeneous crust, correlation of earthquake rates with earth tides should not be detectable at normal stresses in excess of about 8 MPa. Correlation of earthquakes with tides at higher normal stresses can be explained if there exist inhomogeneities that locally amplify the magnitude of the tidal stresses. Such amplification might occur near magma chambers or other soft inclusions in the crust and possibly near the ends of creeping fault segments if the creep or afterslip rates vary in response to tides. Observations of seismicity rate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18222414','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18222414"><span id="translatedtitle"><span class="hlt">Slipping</span> of the foot on the floor when pulling a pallet truck.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Kai Way; Chang, Chien-Chi; Chang, Wen-Ruey</p> <p>2008-11-01</p> <p>Workers pulling pallet trucks are likely to <span class="hlt">slip</span> when pulling and stepping on a low-friction floor. This study investigated the <span class="hlt">slipping</span> of male participants when pulling a pallet truck, walking backward, and stepping on either a dry, wet, or glycerol-contaminated vinyl surface. The weight of the load on the truck was either low (0 kg), medium (295 kg), or high (568 kg). A motion-tracking system was used to collect the three-dimensional coordinates of the markers on the shoes. It was found that subjects might <span class="hlt">slip</span> either upon landing of the leading foot on the toe (<span class="hlt">slip</span> I) or before taking off of the lagging foot on the heel (<span class="hlt">slip</span> II). The results indicated that the <span class="hlt">slip</span> distances for both types of <span class="hlt">slip</span> were significantly affected by the load and surface conditions and their interactions. Micro-<span class="hlt">slips</span> (<span class="hlt">slips</span> between 0.1 and 3 cm) and midi-<span class="hlt">slips</span> (<span class="hlt">slips</span> between 3 and 10 cm) were more common in <span class="hlt">slip</span> I than in <span class="hlt">slip</span> II. On glycerol-contaminated surfaces, the probabilities of a slide, or a <span class="hlt">slip</span> more than 10 cm, for both <span class="hlt">slips</span> I and II were over 40%. The implications of the results were discussed. PMID:18222414</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820019111','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820019111"><span id="translatedtitle">Pressure suit <span class="hlt">joint</span> analyzer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vykukal, H. C.; Webbon, B. W. (Inventor)</p> <p>1982-01-01</p> <p>A measurement system for simultaneously measuring torque and angular flexure in a pressure suit <span class="hlt">joint</span> is described. One end of a <span class="hlt">joint</span> under test is held rigid. A torque transducer is pivotably supported on the other movable end of a <span class="hlt">joint</span>. A potentiometer is attached to the transducer by an arm. The wiper shaft of the potentiometer is gripped by a reference arm that rotates the wiper shaft the same angle as the flexure of <span class="hlt">joint</span>. A signal is generated by the potentiometer which is representative of the <span class="hlt">joint</span> flexure. A compensation circuit converts the output of the transducer to a signal representative of <span class="hlt">joint</span> torque.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T54B..03E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T54B..03E"><span id="translatedtitle">Hot, Fast Faults: Evidence for High-Temperature <span class="hlt">Slip</span> on Exhumed Faults, and Insights into Seismic <span class="hlt">Slip</span> Processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evans, J. P.; Ault, A. K.; Janecke, S. U.; Prante, M. R.</p> <p>2015-12-01</p> <p>Microstructural and geochemical techniques combined with prior observations of naturally occurring faults provide insights into <span class="hlt">slip</span> rates and <span class="hlt">slip</span> dimensions of seismicity. We review four indicators for high coseismic paleotemperatures in brittle to semi-brittle faults from a wide range of tectonic settings with mm to km of <span class="hlt">slip</span>. Thin, high-gloss, Fe-rich <span class="hlt">slip</span> surfaces indicate high-temperature <span class="hlt">slip</span> occurred on mm- to m-scales. Elliptical and circular zones of concentric iridescence indicate localized sites of elevated temperature that may be caused by heating at asperity contacts. The surface iridescence is associated with changes in Fe oxidation states detected by X-Ray photoelectron spectroscopy. Minimum temperature increases of 300 °C above ambient are supported by geochemical arguments and up to 800 °C are supported by analogs to high-speed friction experiments in steels and ceramics firing in reduced conditions. The presence of clay-rich foliated fault-related rocks, and the presence of nm- to mm-thick clay coatings indicate that syn-kinematic endothermic reactions occur at a range of scales. We suggest these features reflect temperature increases of ≥100-200 °C for activation energy required to drive the clay alteration is sourced from seismic energy and Schleicher-van der Pluijm-type <span class="hlt">slip</span> surfaces to record instantaneous <span class="hlt">slip</span>. Dense, low porosity planar porcelainite zones mm- to cm-thick along fault surfaces are the result of sintering of quartz-clay-feldspar mixtures and indicate T≥1000 °C localized along the surfaces, the result of post-<span class="hlt">slip</span> cooling. Highly indurated, ultrafine fault-related rocks often consists of comminuted grains, vein fragments, and neocrystallized grains that represent retrograde cooling or alteration after peak heating. These observations and those of other recent workers indicate that many naturally occurring exhumed faults record elevated temperatures. In many cases, careful observations can delineate fault <span class="hlt">slip</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=238592&keyword=innovation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68464221&CFTOKEN=66653840','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=238592&keyword=innovation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=68464221&CFTOKEN=66653840"><span id="translatedtitle">Sustainable Chemistry, the Spinning <span class="hlt">Tube-in-Tube</span> (STT(R)) Reactor and GREENSCOPE: Innovation and Industrial Partnerships</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The chemical industry faces environmental, social and health challenges that are common across all economic sectors. From worker exposure to toxic substances, to product design and use, to the cost and handling of waste disposal, the industry must overcome numerous complex hurdle...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.4918R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.4918R"><span id="translatedtitle">Seismic velocity change and <span class="hlt">slip</span> rate during the 2006 Guerrero (Mexico) slow <span class="hlt">slip</span> event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivet, Diane; Radiguet, Mathilde; Campillo, Michel; Cotton, Fabrice; Shapiro, Nikolai; Krishna Singh, Shri; Kostoglodov, Vladimir</p> <p>2010-05-01</p> <p>We measure temporal change of the seismic velocity in the crust below the Guerrero region during the 2006 slow sleep event (SSE). We use repeated cross-correlations of ambient seismic noise recorded at 26 broad-band stations of the MesoAmerica Seismic Experiment (MASE). The cross-correlations are computed over 90 days with a moving window of 10 days from January 2005 to July 2007. To insure measurements independent of noise source variations, we only take into account the travel time change within the coda. For period of 8 to 20s, we observe a decrease in velocity starting in April 2006 with a maximum change of -0.3% of the initial velocity in June 2006. At these periods, the Rayleigh waves are sensitive to velocity changes down to the lower crust. In the other hand, we compute the deformation rate below the MASE array from a <span class="hlt">slip</span> propagation model of the SSE observed by means of the displacement time-series of 15 continuous GPS stations. <span class="hlt">Slip</span> initiates in the western part of the Guerrero Gap and propagates southeastward. The propagation velocity is of the order of 1 km/day. We then compare the seismic velocity change measured from continuous seismological data with the deformation rate inferred from geodetic measurements below the MASE array. We obtain a good agreement between the time of maximal seismic velocity change (July 2006) and the time of maximum deformation associated with the SSE (July to August 2006). This result shows that the long-term velocity change associated with the SSE can be detected using continuous seismic recordings. Since the SSE does not emit seismic waves, which interact with the superficial layers, the result indicates that the velocity change is due to deformation at depth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9545C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9545C"><span id="translatedtitle">Interaction between <span class="hlt">slip</span> events, erosion and sedimentation along an active strike-<span class="hlt">slip</span> fault: Insights from analog models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chatton, M.; Malavieille, J.; Dominguez, S.; Manighetti, I.; Romano, C.; Beauprêtre, S.; Garembois, S.; Larroque, C.</p> <p>2012-04-01</p> <p>Recovering information on past (i.e., last 102-104 yrs) large earthquakes on faults is a challenge. The classical approach -especially used on strike-<span class="hlt">slip</span> faults- consists in searching morphological markers such as river channels, streams, alluvial fans, ridges or terrace risers, etc, that would be offset by the fault, and measure these offsets by reconstructing the original position and shape of the markers. Combined with the dating of the offset markers, this morphotectonic paleoseismological approach may provide information on the <span class="hlt">slips</span> and ages of the most recent earthquakes on the fault under study. Yet, the approach is complex as it depends on the recognition of unambiguous paired markers on either side of the fault. And our capability to recognize similar markers on either side of a fault in turn greatly depends on the 'evolution' that these markers may have sustained subsequently to their very first <span class="hlt">slip</span> disruption. Did the repeating earthquake <span class="hlt">slip</span> events modify their surface appearance? Did their morphology and position (ex: burying, destruction, modification, etc) evolve with the sedimentation and erosion that might have occurred during the fault history? Etc. These questions have rarely been approached for they are difficult to address in natural settings. And as we are unable to answer them in the natural cases that we study, the <span class="hlt">slip</span> reconstructions that we provide are generally uncertain as they are likely based on an incomplete or biased record of the past fault <span class="hlt">slips</span>. Therefore, the objective of our work is to contribute to better understand and document the nature and 'evolution' of the morphological markers that are commonly used in morphotectonic and paleoseismological analyses, especially along strike-<span class="hlt">slip</span> faults. We approach these questions experimentally. We have developed an original experimental set-up made to simulate repeated <span class="hlt">slip</span> events on a strike-<span class="hlt">slip</span> fault placed in a wet environment sustaining sedimentation and erosion. The fault</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T21D..02W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T21D..02W"><span id="translatedtitle">A comparison of <span class="hlt">slip</span> rate, recurrence interval, and <span class="hlt">slip</span> per event on several well-characterized faults (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weldon, R. J.; Lippoldt, R. C.; Scharer, K.; Streig, A. R.; Langridge, R. M.; Madugo, C. M.; Biasi, G. P.; Dawson, T. E.</p> <p>2013-12-01</p> <p>Rapid growth in the application of LiDAR and other modern geodetic techniques has led to an explosion in the number of micro-geomorphic offsets along faults that can be interpreted as displacement in one or several earthquakes. As a result of this new data there are an increasing number of places along faults for which data are available for the <span class="hlt">slip</span> rate (based on the dated offset of a feature that is old enough to average out the seismic cycle), recurrence interval (based on a representative number of dated paleo-earthquakes), and <span class="hlt">slip</span> per event (based on an adequate sample of micro-geomorphic or 3D-excavated offsets). Because these three datasets are largely independent, but related by accumulation and release of strain across the fault, comparing them can provide insight into how faults balance size and frequency of earthquakes. We discuss several examples of faults with closely co-located <span class="hlt">slip</span> rate, recurrence interval, and <span class="hlt">slip</span> per event data, including the Ana River fault, a small normal fault in Central Oregon, and portions of the San Andreas fault, the principal plate boundary fault in California. The Ana River fault offsets more than 11 Pleistocene shorelines different amounts that we have measured using a combination of LiDAR, ground-based surveying, and a DEM generated from a USGS topographic map with 5 foot contours. The ages of ~10 paleo-earthquakes are determined from trenches and other exposures into deep-water lacustrine deposits that contain ~50 dated volcanic ashes. The long-term <span class="hlt">slip</span> rate, 0.05 mm/yr, is known from the total offset of dated late Pliocene basalts. We also use new data from the Santa Cruz segment of the northern San Andreas fault (NSAF) and the southern San Andreas fault (SSAF: Parkfield to Bombay Beach). On the NSAF, earthquakes in 1838, 1890, and 1906 have a total <span class="hlt">slip</span> of 4 - 6 m while the <span class="hlt">slip</span> rate (17 mm/yr) suggests it would take 2 - 3 centuries to accumulate this much strain. Data for the SSAF, which have recently been</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.T54A..02H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.T54A..02H"><span id="translatedtitle">Energy Partitioning during Frictional Sliding at Coseismic <span class="hlt">Slip</span> Rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hirose, T.; Mizoguchi, K.</p> <p>2008-12-01</p> <p>Determination of the energy partitioning during an earthquake is key to understanding the physics of earthquakes (e.g., Kanamori and Rivera, 2006). Observations made on natural faults that have experienced earthquakes suggest that part of the energy dissipates into a volume of rock surrounding the fault though grain crushing processes, forming fault gouge (e.g., Wilson et al., 2005). Thus we performed high-velocity wear experiments using a rotary-shear apparatus, in order to estimate the partitioning of the frictional work into heat and surface energy during frictional sliding at nearly coseismic <span class="hlt">slip</span> rates. In particular, we attempted to test whether the ratio of the energy partitioning varies as a function of <span class="hlt">slip</span> rate. The ratio of dissipated energy as heat to the total frictional work was estimated from the difference between measured temperature around the sliding surfaces and calculated temperature by 2D-FEM on the assumption that all frictional work converts into heat. The surface energy was estimated based on the particle size distribution of the wear materials, which was determined by FE-SEM image analysis. The particles size ranged between 0.03 and 10 μm in average diameter. In the experiments, hollow cylindrical specimens of gabbro were slid at <span class="hlt">slip</span> rates of 0.004 to 0.3 m/s and normal stresses of 0.2 to 5.6 MPa under unconfined and dry conditions. Rock powder (gouge) was continuously produced by abrasive wear of initially bare fault surfaces during sliding. Because the sliding surfaces were not confined in the experiments, the gouge was extruded from the fault surfaces, resulting in shortening of axial length of specimen. In this study, we defined the dimensionless wear rate, given by that an axial shortening rate of the specimen was divided by <span class="hlt">slip</span> rate. Then, we examined how the wear rate and temperature changed as a function of the rate of frictional work per a unit fault area, Ef, determined by shear stress multiplied by <span class="hlt">slip</span> rate. Hereafter, Q and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810412A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810412A"><span id="translatedtitle">Multi-asperity models of slow <span class="hlt">slip</span> and tremor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ampuero, Jean Paul; Luo, Yingdi; Lengline, Olivier; Inbal, Asaf</p> <p>2016-04-01</p> <p>Field observations of exhumed faults indicate that fault zones can comprise mixtures of materials with different dominant deformation mechanisms, including contrasts in strength, frictional stability and hydrothermal transport properties. Computational modeling helps quantify the potential effects of fault zone heterogeneity on fault <span class="hlt">slip</span> styles from seismic to aseismic <span class="hlt">slip</span>, including slow <span class="hlt">slip</span> and tremor phenomena, foreshocks sequences and swarms, high- and low-frequency radiation during large earthquakes. We will summarize results of ongoing modeling studies of slow <span class="hlt">slip</span> and tremor in which fault zone structure comprises a collection of frictionally unstable patches capable of seismic <span class="hlt">slip</span> (tremorgenic asperities) embedded in a frictionally stable matrix hosting aseismic transient <span class="hlt">slips</span>. Such models are consistent with the current view that tremors result from repeated shear failure of multiple asperities as Low Frequency Earthquakes (LFEs). The collective behavior of asperities embedded in creeping faults generate a rich spectrum of tremor migration patterns, as observed in natural faults, whose seismicity rate, recurrence time and migration speed can be mechanically related to the underlying transient slow <span class="hlt">slip</span> rate. Tremor activity and slow <span class="hlt">slip</span> also responds to periodic loadings induced by tides or surface waves, and models relate tremor tidal sensitivity to frictional properties, fluid pressure and creep rate. The overall behavior of a heterogeneous fault is affected by structural parameters, such as the ratio of stable to unstable materials, but also by time-dependent variables, such as pore pressure and loading rate. Some behaviors are well predicted by homogenization theory based on spatially-averaged frictional properties, but others are somewhat unexpected, such as seismic <span class="hlt">slip</span> behavior found in asperities that are much smaller than their nucleation size. Two end-member regimes are obtained in rate-and-state models with velocity-weakening asperities</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S31A2708S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S31A2708S"><span id="translatedtitle">Effective heterogeneity controlling premonitory <span class="hlt">slip</span> on laboratory faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Selvadurai, P. A.; Glaser, S.; Parker, J.</p> <p>2015-12-01</p> <p>Using a direct shear friction apparatus, we characterize factors controlling rheological differences along a PMMA-PMMA fault in the laboratory. Rheological differences on natural faults are believed to be a controlling factor to aseismic transients (slow <span class="hlt">slip</span>) in nature. Asperity sizes and locations were measured using a pressure sensitive film at high (σn = 0.8 MPa) and low (σn = 0.4 MPa) nominal normal stress levels. Faults confined to low and high normal stress experienced lower and higher 'effective heterogeneity,' quantified using a characteristic elastic correlation length λc [Braun and Peyrard, 2012]. The fault was sheared at a constant far-field velocity VLP under constant normal stress σn. Non-uniform premonitory <span class="hlt">slip</span> accumulated along the fault prior to rapid sliding. Slow events (SE), which were characterized as local increases in <span class="hlt">slip</span> rate, were observed when the effective heterogeneity was increased. These events nucleated from the weaker central section of the fault propagating outwards at speeds between 0.84 mm/s to 26.5 mm/s over times 406 s and 11 s. The rupture growth rates were dependent on the load-point velocity VLP driving the system to failure. <span class="hlt">Slip</span> rates, which increased within the SE, were also dependent on the load-point velocity. The evolution of <span class="hlt">slip</span> rates versus time was similar to the 2013-2014 Boso slow <span class="hlt">slip</span> event [Fukuda et al., 2014]. The slow event culminated with rapid <span class="hlt">slip</span> rate deceleration sufficient to generate seismicity measured by an array of acoustic emission sensors. Deceleration of the SE (left panel of figure) shows a lower-frequency event (~ 60 - 350 Hz). In Detail A, we show the smaller, high-frequency events (~ 300 - 500 kHz) were superimposed on the larger, low-frequency signal. These events only occurred at higher levels of effective heterogeneity and demonstrate interactions between larger/slow and localized/fast <span class="hlt">slip</span>. References: Braun, O. M. & M. Peyrard (2012), 'Crack in the frictional interface as a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S21B4441T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S21B4441T"><span id="translatedtitle">Size Distribution of <span class="hlt">Slip</span> Values in Finite-Fault Rupture Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thingbaijam, K. K. S.; Mai, P. M.</p> <p>2014-12-01</p> <p>Understanding statistical properties of earthquake sources is crucial for proper ground-motion predictions. We investigate the size distribution of <span class="hlt">slip</span> values as imaged by finite-fault rupture models. Our analysis utilizes rupture models from the SRCMOD database (http://equake-rc.info/srcmod). To overcome the limitation of variable spatial sampling across different models, we consider combined areas of fault-rupture corresponding to different <span class="hlt">slip</span> bins. The <span class="hlt">slip</span> values in each rupture model are binned according to fractions of the overall maximum <span class="hlt">slip</span>. We refer to the rupture area occupied by a specified <span class="hlt">slip</span> bin as <span class="hlt">slip</span>-area. To eliminate possible spurious small <span class="hlt">slip</span> at the fault edge, we compute the effective source dimensions from the <span class="hlt">slip</span> distribution, accounting for sub-fault size, location of <span class="hlt">slip</span>-asperities, and surface rupture (if present). This procedure includes trimming the model to the smallest dimensions that accommodate the autocorrelation width of the <span class="hlt">slip</span> distribution (Mai and Beroza, 2000). We modify the trimming process to not affect any large <span class="hlt">slip</span> asperity (u ≥ umax/3) where u and umax denote <span class="hlt">slip</span> and maximum <span class="hlt">slip</span> value. In order to look beyond individual models, we develop scaling relationships between seismic moment and <span class="hlt">slip</span>-areas. These relationships are, thereafter, employed to derive average tail distribution (or exceedance) of the <span class="hlt">slip</span> values. Our regression analysis reveals that self-similar source scaling holds for dip-<span class="hlt">slip</span> events while scale invariance breaks down for large strike-<span class="hlt">slip</span> events. We find that the tail distributions of the <span class="hlt">slip</span> values can be described by stretched-exponential functions, with the averaged distribution close to exponential. This characterization of the <span class="hlt">slip</span> distribution agrees with the source scaling laws, and will be useful in generating realistic earthquake rupture scenarios for ground-motion modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.P43B3984S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.P43B3984S"><span id="translatedtitle">Global Morphological Mapping of Strike-<span class="hlt">Slip</span> Structures on Ganymede</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith-Konter, B. R.; Cameron, M. E.; Seifert, F.; Pappalardo, R. T.; Collins, G. C.</p> <p>2014-12-01</p> <p>Many inferences of strike-<span class="hlt">slip</span> faulting and distributed shear zones on Ganymede suggest that strike-<span class="hlt">slip</span> tectonism may be important to the structural development of its surface and in the transition from dark to light (grooved) materials. To better understand the role of strike-<span class="hlt">slip</span> tectonism in shaping Ganymede's multifaceted surface, we identify and map key examples of strike-<span class="hlt">slip</span> morphologies (en echelon structures, strike-<span class="hlt">slip</span> duplexes, laterally offset pre-existing features, and possible strained craters) from Galileo and Voyager images. Here we present the current state of these global mapping efforts, with particular emphasis given to complex structures associated with grooved terrain (e.g. Nun Sulci) and terrains transitional from dark to light terrain (e.g. the boundary between Nippur Sulcus and Marius Regio). These results are being synthesized into a global database representing an inferred sense of shear for fractures on Ganymede. This, combined with existing observations of extensional features, is helping to narrow down the range of possible principal stress directions that could have acted at the regional or global scale to produce grooved terrain. Moreover, these data sets, combined with mechanical models of shear failure and global stress sources, are providing constraints for testing possible mechanisms for grooved terrain formation on Ganymede.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MAR.X1002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MAR.X1002G"><span id="translatedtitle">Measurement of Quantum Phase-<span class="hlt">Slips</span> in Josephson Junction Chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guichard, Wiebke</p> <p>2011-03-01</p> <p>Quantum phase-<span class="hlt">slip</span> dynamics in Josephson junction chains could provide the basis for the realization of a new type of topologically protected qubit or for the implementation of a new current standard. I will present measurements of the effect of quantum phase-<span class="hlt">slips</span> on the ground state of a Josephson junction chain. We can tune in situ the strength of the phase-<span class="hlt">slips</span>. These phase-<span class="hlt">slips</span> are the result of fluctuations induced by the finite charging energy of each junction in the chain. Our measurements demonstrate that a Josephson junction chain under phase bias constraint behaves in a collective way. I will also show evidence of coherent phase-<span class="hlt">slip</span> interference, the so called Aharonov-Casher effect. This phenomenon is the dual of the well known Aharonov-Bohm interference. In collaboration with I.M. Pop, Institut Neel, C.N.R.S. and Universite Joseph Fourier, BP 166, 38042 Grenoble, France; I. Protopopov, L. D. Landau Institute for Theoretical Physics, Kosygin str. 2, Moscow 119334, Russia and Institut fuer Nanotechnologie, Karlsruher Institut fuer Technologie, 76021 Karlsruhe, Germany; and F. Lecocq, Z. Peng, B. Pannetier, O. Buisson, Institut Neel, C.N.R.S. and Universite Joseph Fourier. European STREP MIDAS, ANR QUANTJO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3211984','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3211984"><span id="translatedtitle">Scaling analysis for the investigation of <span class="hlt">slip</span> mechanisms in nanofluids</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2011-01-01</p> <p>The primary objective of this study is to investigate the effect of <span class="hlt">slip</span> mechanisms in nanofluids through scaling analysis. The role of nanoparticle <span class="hlt">slip</span> mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the <span class="hlt">slip</span> mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of <span class="hlt">slip</span> mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of <span class="hlt">slip</span> mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it. PMID:21791036</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011NRL.....6..471S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011NRL.....6..471S"><span id="translatedtitle">Scaling analysis for the investigation of <span class="hlt">slip</span> mechanisms in nanofluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Savithiri, S.; Pattamatta, Arvind; Das, Sarit K.</p> <p>2011-07-01</p> <p>The primary objective of this study is to investigate the effect of <span class="hlt">slip</span> mechanisms in nanofluids through scaling analysis. The role of nanoparticle <span class="hlt">slip</span> mechanisms in both water- and ethylene glycol-based nanofluids is analyzed by considering shape, size, concentration, and temperature of the nanoparticles. From the scaling analysis, it is found that all of the <span class="hlt">slip</span> mechanisms are dominant in particles of cylindrical shape as compared to that of spherical and sheet particles. The magnitudes of <span class="hlt">slip</span> mechanisms are found to be higher for particles of size between 10 and 80 nm. The Brownian force is found to dominate in smaller particles below 10 nm and also at smaller volume fraction. However, the drag force is found to dominate in smaller particles below 10 nm and at higher volume fraction. The effect of thermophoresis and Magnus forces is found to increase with the particle size and concentration. In terms of time scales, the Brownian and gravity forces act considerably over a longer duration than the other forces. For copper-water-based nanofluid, the effective contribution of <span class="hlt">slip</span> mechanisms leads to a heat transfer augmentation which is approximately 36% over that of the base fluid. The drag and gravity forces tend to reduce the Nusselt number of the nanofluid while the other forces tend to enhance it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AIPC.1662c0002O&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AIPC.1662c0002O&link_type=ABSTRACT"><span id="translatedtitle">Biodegradable polymers: Wall <span class="hlt">slip</span>, melt fracture, and processing aids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Othman, Norhayani; Noroozi, Nazbanoo; Jazrawi, Bashar; Mehrkhodavandi, Parisa; Schafer, Laurel; Hatzikiriakos, Savvas George</p> <p>2015-04-01</p> <p>The wall <span class="hlt">slip</span> and melt fracture behaviour of several commercial polylactides (PLAs) and poly(ɛ-caprolactone), (PCLs) have been investigated. PLAs with molecular weights greater than a certain value were found to <span class="hlt">slip</span>, with the <span class="hlt">slip</span> velocity to increase with decrease of molecular weight consistent with wall <span class="hlt">slip</span> data reported in the literature for other systems. The onset of melt fracture for the high molecular weight PLAs was found to occur at about 0.2 to 0.3 MPa, depending on the geometrical characteristics of the dies and independent of temperature. Similarly, sharkskin and gross melt fracture was observed for the case of PCLs depending on the molecular characteristics of the resins and the geometrical details of the capillary dies. It was also found that the addition of a small amount of PCL (typically 0.5 wt.%) into the PLA and vice versa is effective in eliminating and delaying the onset of melt fracture to higher shear rates in the capillary extrusion of PLA and PCL respectively. This is due to significant interfacial <span class="hlt">slip</span> that occurs in the presence of PCL or PLA as well as to the immiscibility of the PLA/PCL blend system at all compositions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012NJPh...14l5009B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012NJPh...14l5009B"><span id="translatedtitle"><span class="hlt">Slip</span> velocity of large neutrally buoyant particles in turbulent flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bellani, G.; Variano, E. A.</p> <p>2012-12-01</p> <p>We discuss possible definitions for a stochastic <span class="hlt">slip</span> velocity that describes the relative motion between large particles and a turbulent flow. This definition is necessary because the <span class="hlt">slip</span> velocity used in the standard drag model fails when particle size falls within the inertial subrange of ambient turbulence. We propose two definitions, selected in part due to their simplicity: they do not require filtration of the fluid phase velocity field, nor do they require the construction of conditional averages on particle locations. A key benefit of this simplicity is that the stochastic <span class="hlt">slip</span> velocity proposed here can be calculated equally well for laboratory, field and numerical experiments. The stochastic <span class="hlt">slip</span> velocity allows the definition of a Reynolds number that should indicate whether large particles in turbulent flow behave (a) as passive tracers; (b) as a linear filter of the velocity field; or (c) as a nonlinear filter to the velocity field. We calculate the value of stochastic <span class="hlt">slip</span> for ellipsoidal and spherical particles (the size of the Taylor microscale) measured in laboratory homogeneous isotropic turbulence. The resulting Reynolds number is significantly higher than 1 for both particle shapes, and velocity statistics show that particle motion is a complex nonlinear function of the fluid velocity. We further investigate the nonlinear relationship by comparing the probability distribution of fluctuating velocities for particle and fluid phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMMR33C2690C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMMR33C2690C"><span id="translatedtitle">How Orogen-scale Exhumed Strike-<span class="hlt">slip</span> Faults Initiate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, S.; Neubauer, F.</p> <p>2015-12-01</p> <p>Orogen-scale strike-<span class="hlt">slip</span> faults present one the most important geodynamic processes affecting the lithosphere-asthenosphere system. In specific subtypes, faulting is virtually initiated along hot-to-cool boundaries, e.g. at such of hot granite intrusions or metamorphic core complexes to cool country rocks. Such fault zones are often subparallel to mountain ranges and expose a wide variety of mylonitic, cataclastic and non-cohesive fault rocks, which were formed at different structural levels of the crust and are stacked within each other ("telescoping"). Exhumation of rocks is, therefore, a common feature of such strike-<span class="hlt">slip</span> faults implying major transtensive and/or transpressive processes accompanying pure strike-<span class="hlt">slip</span> motion. The hot-to-cool thermal structure across the fault zone significantly influences the physical fault rock properties. One major question is how and where a major strike-<span class="hlt">slip</span> initiates and further development. Here, we propose a model in which major continental exhumed strike-<span class="hlt">slip</span> faults potentially evolve along rheologically weak zones such as plutons or margins of metamorphic complexes. As an example, we propose a model for the Ailao Shan-Red River (ASRR) fault, SE Asia, which initiated along the edge of a plutonic belt and evolved in response to India-Asia collision with four tectonic phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26653674','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26653674"><span id="translatedtitle">Generalization of treadmill perturbation to overground <span class="hlt">slip</span> during gait: Effect of different perturbation distances on <span class="hlt">slip</span> recovery.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Anna; Bhatt, Tanvi; Pai, Yi-Chung</p> <p>2016-01-25</p> <p>Treadmill-perturbation training (TM-training) may improve a person׳s fall-resistance, whereby adjusting <span class="hlt">slip</span> distance can be a simple way to manipulate training intensity. The purpose of this study was to determine the effects of different <span class="hlt">slip</span> distances in TM-training (12-cm vs. 18-cm) on its generalization to the recovery from a novel "free" <span class="hlt">slip</span> during overground walking. Generalization here means the ability to apply learned skill from TM-training to <span class="hlt">slip</span> recovery during overground walking. Thirty-six young adults in the TM_12 or the TM_18 group underwent either a 12-cm or an 18-cm <span class="hlt">slip</span> during the treadmill walking for seven times, or in the control group were not exposed to any perturbation. Their responses were also contrasted with previously reported results from overground-perturbation training (OG-training) in which participants received either a 12-cm or an 18-cm <span class="hlt">slip</span> during level walking with the same number of repetitions. Everyone was then exposed to the same generalization test during a novel "free" <span class="hlt">slip</span> in overground walking. Their proactive and reactive control of stability was measured and compared. TM-training displayed a significant training effect in comparison to the control group (p<0.05), while most of the improvements were found in the reactive control of stability and were much-limited in comparison to that of OG-training. Also unlike OG-training, no significant differences were found between the results obtained from the TM_12 and the TM_18 groups (p>0.05). These results underscore the further needs to investigate the potential of the treadmill as a convenient instrument that can effectively deliver perturbation training.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/003742.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/003742.htm"><span id="translatedtitle">Culture - <span class="hlt">joint</span> fluid</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p><span class="hlt">Joint</span> fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of <span class="hlt">joint</span> ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/temporomandibularjointdysfunction.html','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/temporomandibularjointdysfunction.html"><span id="translatedtitle">Temporomandibular <span class="hlt">Joint</span> Dysfunction</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>The temporomandibular <span class="hlt">joint</span> (TMJ) connects your jaw to the side of your head. When it works well, it enables you to ... For people with TMJ dysfunction, problems with the <span class="hlt">joint</span> and muscles around it may cause Pain that ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/874536','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/874536"><span id="translatedtitle">Large displacement spherical <span class="hlt">joint</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bieg, Lothar F.; Benavides, Gilbert L.</p> <p>2002-01-01</p> <p>A new class of spherical <span class="hlt">joints</span> has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these <span class="hlt">joints</span> move freely without singularities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/002975.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/002975.htm"><span id="translatedtitle">Hip <span class="hlt">joint</span> replacement</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... this page: //medlineplus.gov/ency/article/002975.htm Hip <span class="hlt">joint</span> replacement To use the sharing features on this page, please enable JavaScript. Hip <span class="hlt">joint</span> replacement is surgery to replace all or part ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27554487','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27554487"><span id="translatedtitle">[Total temporomandibular <span class="hlt">joint</span> prostheses].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zwetyenga, N; Amroun, S; Wajszczak, B-L; Moris, V</p> <p>2016-09-01</p> <p>The temporomandibular <span class="hlt">joint</span> (TMJ) is probably the most complex human <span class="hlt">joint</span>. As in all <span class="hlt">joints</span>, its prosthetic replacement may be indicated in selected cases. Significant advances have been made in the design of TMJ prostheses during the last three decades and the indications have been clarified. The aim of our work was to make an update on the current total TMJ total <span class="hlt">joint</span> replacement. Indications, contraindications, prosthetic components, advantages, disadvantages, reasons for failure or reoperation, virtual planning and surgical protocol have been exposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/458579','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/458579"><span id="translatedtitle"><span class="hlt">Slip</span> stream apparatus and method for treating water in a circulating water system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cleveland, J.R.</p> <p>1997-03-18</p> <p>An apparatus is described for treating water in a circulating water system that has a cooling water basin which includes a <span class="hlt">slip</span> stream conduit in flow communication with the circulating water system, a source of acid solution in flow communication with the <span class="hlt">slip</span> stream conduit, and a decarbonator in flow communication with the <span class="hlt">slip</span> stream conduit and the cooling water basin. In use, a <span class="hlt">slip</span> stream of circulating water is drawn from the circulating water system into the <span class="hlt">slip</span> stream conduit of the apparatus. The <span class="hlt">slip</span> stream pH is lowered by contact with an acid solution provided from the source thereof. The <span class="hlt">slip</span> stream is then passed through a decarbonator to form a treated <span class="hlt">slip</span> stream, and the treated <span class="hlt">slip</span> stream is returned to the cooling water basin. 4 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870868','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870868"><span id="translatedtitle"><span class="hlt">Slip</span> stream apparatus and method for treating water in a circulating water system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Cleveland, Joe R.</p> <p>1997-01-01</p> <p>An apparatus (10) for treating water in a circulating water system (12) t has a cooling water basin (14) includes a <span class="hlt">slip</span> stream conduit (16) in flow communication with the circulating water system (12), a source (36) of acid solution in flow communication with the <span class="hlt">slip</span> stream conduit (16), and a decarbonator (58) in flow communication with the <span class="hlt">slip</span> stream conduit (16) and the cooling water basin (14). In use, a <span class="hlt">slip</span> stream of circulating water is drawn from the circulating water system (12) into the <span class="hlt">slip</span> stream conduit (16) of the apparatus (10). The <span class="hlt">slip</span> stream pH is lowered by contact with an acid solution provided from the source (36) thereof. The <span class="hlt">slip</span> stream is then passed through a decarbonator (58) to form a treated <span class="hlt">slip</span> stream, and the treated <span class="hlt">slip</span> stream is returned to the cooling water basin (14).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.P31B2067C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.P31B2067C"><span id="translatedtitle">What causes an icy fault to <span class="hlt">slip</span>? Investigating strike-<span class="hlt">slip</span> failure conditions on Ganymede at Dardanus and Tiamat Sulcus.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cameron, M. E.; Smith-Konter, B. R.; Burkhard, L. M.; Collins, G. C.; Seifert, F.; Pappalardo, R. T.</p> <p>2015-12-01</p> <p>Ganymede exhibits two geologically distinct terrains known as dark and light (grooved) terrain. The mechanism for a transition from dark to light terrain remains unclear; however, inferences of strike-<span class="hlt">slip</span> faulting and distributed shear zones suggest that strike-<span class="hlt">slip</span> tectonism may be important to the structural development of Ganymede's surface and in this transition. Here we investigate the role of tidal stresses on Ganymede in the formation and evolution of strike-<span class="hlt">slip</span> structures in both dark and grooved terrains. Using numerical code SatStress, we calculate both diurnal and non-synchronous rotation (NSR) tidal stresses at Ganymede's surface. Specifically, we investigate the role of fault friction and orbital eccentricity in the development of ~45 km of right-lateral offset at Dardanus Sulcus and a possible case of <10 km of right-lateral offset at Tiamat Sulcus. We compute Coulomb failure conditions for these target fractures and consider tidal stress scenarios for both present eccentricity (0.0013) and possible past high (~0.05) eccentricity of Ganymede. We find that while diurnal stresses are not large enough to support strike-<span class="hlt">slip</span> failure at present or past eccentricities, models that include both diurnal and NSR stress readily generate shear and normal stress magnitudes that could give rise to shear failure. Results for a past high eccentricity assuming a low coefficient of friction (μf = 0.2) suggest shear failure is possible down to depths of 1-2 km along both Dardanus and Tiamat. For a high coefficient of friction (μf = 0.6), failure is limited to about 1 km depth at Dardanus and Tiamat, although confined to small episodic <span class="hlt">slip</span> windows for the latter. Moreover, our models predict a right-lateral sense of <span class="hlt">slip</span>, in agreement with inferred offset observed at both regions. Based on these results, we infer that past shear failure on Ganymede is possible when NSR is a driving stress mechanism. We complement this study with a detailed morphological mapping of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED561979.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED561979.pdf"><span id="translatedtitle"><span class="hlt">Joint</span> Enrollment Report, 2014</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Iowa Department of Education, 2014</p> <p>2014-01-01</p> <p>The Iowa Department of Education collects information on <span class="hlt">joint</span> enrollment in Iowa's 15 community colleges. <span class="hlt">Jointly</span> enrolled students are high school students enrolled in community college credit coursework. Most <span class="hlt">jointly</span> enrolled students enroll through Senior Year Plus (SYP) programs such as Postsecondary Enrollment Options (PSEO) and concurrent…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850013263','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850013263"><span id="translatedtitle">Surface-<span class="hlt">slip</span> equations for multicomponent nonequilibrium air flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gupta, R. N.; Scott, C. D.; Moss, J. N.</p> <p>1985-01-01</p> <p>Equations are presented for the surface-<span class="hlt">slip</span> (or jump) values of species concentration, pressure, velocity, and temperature in the low-Reynolds number, high-altitude flight regime of a space vehicle. The equations are obtained from closed form solutions of the mass, momentum, and energy flux equations using the Chapman-Enskog velocity distribution function. This function represents a solution of the Boltzmann equation in the Navier-Stokes approximation. The analysis, obtained for nonequilibrium multicomponent air flow, includes the finite-rate surface catalytic recombination and changes in the internal energy during reflection from the surface. Expressions for the various <span class="hlt">slip</span> quantities were obtained in a form which can be employed in flowfield computations. A consistent set of equations is provided for multicomponent, binary, and single species mixtures. Expression is also provided for the finite-rate, species-concentration boundary condition for a multicomponent mixture in absence of <span class="hlt">slip</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AmJPh..70.1025P&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002AmJPh..70.1025P&link_type=ABSTRACT"><span id="translatedtitle">Does the Euler Disk <span class="hlt">slip</span> during its motion?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petrie, D.; Hunt, J. L.; Gray, C. G.</p> <p>2002-10-01</p> <p>The motion of a disk that is spun on a smooth flat surface slowly damps out due to friction. To help identify the nature of the friction, we test experimentally whether the disk <span class="hlt">slips</span> during its motion. We find that, at least during the early stages, the disk rolls without <span class="hlt">slipping</span>, thus ruling out sliding friction as the cause of the damping. Together with the results of the experiments of van der Engh et al. that rule out air friction, our results establish that rolling friction is mainly responsible for the damping in the early stages of the motion. Student projects are suggested that could establish whether our conclusion of rolling without <span class="hlt">slipping</span> holds for the later stages of the motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005GeoJI.162..406A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GeoJI.162..406A"><span id="translatedtitle">Can observations of earthquake scaling constrain <span class="hlt">slip</span> weakening?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abercrombie, Rachel E.; Rice, James R.</p> <p>2005-08-01</p> <p>We use observations of earthquake source parameters over a wide magnitude range (MW~ 0-7) to place constraints on constitutive fault weakening. The data suggest a scale dependence of apparent stress and stress drop; both may increase slightly with earthquake size. We show that this scale dependence need not imply any difference in fault zone properties for different sized earthquakes. We select 30 earthquakes well-recorded at 2.5 km depth at Cajon Pass, California. We use individual and empirical Green's function spectral analysis to improve the resolution of source parameters, including static stress drop (Δσ) and total <span class="hlt">slip</span> (S). We also measure radiated energy ES. We compare the Cajon Pass results with those from larger California earthquakes including aftershocks of the 1994 Northridge earthquake and confirm the results of Abercrombie (1995): μES/M0<<Δσ (where μ= rigidity) and both ES/M0 and Δσ increase as M0 (and S) increases. Uncertainties remain large due to model assumptions and variations between possible models, and earthquake scale independence is possible within the resolution. Assuming that the average trends are real, we define a quantity G'= (Δσ- 2μES/M0)S/2 which is the total energy dissipation in friction and fracture minus σ1S, where σ1 is the final static stress. If σ1=σd, the dynamic shear strength during the last increments of seismic <span class="hlt">slip</span>, then G'=G, the fracture energy in a <span class="hlt">slip</span>-weakening interpretation of dissipation. We find that G' increases with S, from ~103 J m-2 at S= 1 mm (M1 earthquakes) to 106-107 J m-2 at S= 1 m (M6). We tentatively interpret these results within <span class="hlt">slip</span>-weakening theory, assuming G'~G. We consider the common assumption of a linear decrease of strength from the yield stress (σp) with <span class="hlt">slip</span> (s), up to a <span class="hlt">slip</span> Dc. In this case, if either Dc, or more generally (σp-σd) Dc, increases with the final <span class="hlt">slip</span> S we can match the observations, but this implies the unlikely result that the early weakening behaviour of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.S21E..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.S21E..04A"><span id="translatedtitle">Small Earthquake Scaling Revisited: Can it Constrain <span class="hlt">Slip</span> Weakening?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abercrombie, R. E.; Rice, J. R.</p> <p>2001-12-01</p> <p>We select 29 earthquakes well-recorded at 2.5 km depth at Cajon Pass (Abercrombie, 1995), including some colocated events. We compare spectral and time domain inferences of the source dimension to estimate final <span class="hlt">slip</span> s and static stress drop Δ τ . We measure radiated energy Es by integration of the velocity-squared spectra using simple fits to extend the bandwidth outside the observed range to ensure we do not lose significant energy due to instrumental limits. (The Es estimates of Abercrombie (1995) for earthquakes Mo < 5x 1011 Nm are selectively biased to small stress drops, but otherwise the results are similar.) We compare the CJP results with those from larger California earthquakes including Northridge aftershocks and confirm Abercrombie (1995): for the smallest earthquakes, μ Es/M_o << Δ τ (where μ = rigidity) and Es/M_o increases more rapidly than Δ τ as Mo (and also s) increases. To interpret this we define a quantity G' = [Δ τ - 2μ Es/M_o]s/2 which is the total energy dissipation in friction and fracture minus τ s s, where τ s is the final static stress. If τ s = τ d, the dynamic shear strength during the last increments of seismic <span class="hlt">slip</span>, then G' = G, the fracture energy in a <span class="hlt">slip</span>-weakening interpretation of dissipation, with τ d then identified as the residual shear strength of Palmer and Rice (1973). Otherwise G' = G + (τ d - τ s)s. We find that G' increases with s, from ~103 J/m2 at s = 1 mm (M1 events) to 106 to 107 J/m2 at s = 1 m (M6). An increasing rupture velocity with Mo cannot explain these results because it would imply unreasonably high Δ τ for the small earthquakes. We tentatively interpret these results within <span class="hlt">slip</span>-weakening theory, assuming G' ≈ G (i.e., τ s ≈ τ d). One explanation for these observations within the often assumed linear decrease of strength with <span class="hlt">slip</span>, up to a <span class="hlt">slip</span> Dc, is that either Dc, or the peak to residual strength drop τ p - τ d, or more generally (τ p - τ d) Dc, varies in proportion to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2003/0017/pdf/of03-17.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2003/0017/pdf/of03-17.pdf"><span id="translatedtitle">Preliminary soil-<span class="hlt">slip</span> susceptibility maps, southwestern California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.</p> <p>2003-01-01</p> <p>This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil <span class="hlt">slip</span>-debris flows in southwestern California. As such, the maps offer a partial answer to one part of the three parts necessary to predict the soil-<span class="hlt">slip</span>/debris-flow process. A complete prediction of the process would include assessments of “where”, “when”, and “how big”. These maps empirically show part of the “where” of prediction (i.e., relative susceptibility to sites of initiation of the soil <span class="hlt">slips</span>) but do not attempt to show the extent of run out of the resultant debris flows. Some information pertinent to “when” the process might begin is developed. “When” is determined mostly by dynamic factors such as rainfall rate and duration, for which local variations are not amenable to long-term prediction. “When” information is not provided on the maps but is described later in this narrative. The prediction of “how big” is addressed indirectly by restricting the maps to a single type of landslide process—soil <span class="hlt">slip</span>-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil <span class="hlt">slips</span> were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil <span class="hlt">slips</span>, were used as the basis for soil <span class="hlt">slip</span>-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil <span class="hlt">slip</span> locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-<span class="hlt">slip</span> debris flows were found to be important and others were not. The most important attribute was the mapped bedrock formation at the site of initiation of the soil <span class="hlt">slip</span>. However, because the soil <span class="hlt">slips</span> occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870018512','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870018512"><span id="translatedtitle">Surface-<span class="hlt">slip</span> equations for multicomponent, nonequilibrium air flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gupta, Roop N.; Scott, Carl D.; Moss, James N.; Goglia, Gene</p> <p>1985-01-01</p> <p>Equations are presented for the surface <span class="hlt">slip</span> (or jump) values of species concentration, pressure, velocity, and temperature in the low-Reynolds-number, high-altitude flight regime of a space vehicle. These are obtained from closed-form solutions of the mass, momentum, and energy flux equations using the Chapman-Enskog velocity distribution function. This function represents a solution of the Boltzmann equation in the Navier-Stokes approximation. The analysis, obtained for nonequilibrium multicomponent air flow, includes the finite-rate surface catalytic recombination and changes in the internal energy during reflection from the surface. Expressions for the various <span class="hlt">slip</span> quantities have been obtained in a form which can readily be employed in flow-field computations. A consistent set of equations is provided for multicomponent, binary, and single species mixtures. Expression is also provided for the finite-rate species-concentration boundary condition for a multicomponent mixture in absence of <span class="hlt">slip</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998APS..MAR.G3709A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998APS..MAR.G3709A"><span id="translatedtitle">Quantum Nucleation of Phase <span class="hlt">Slips</span> in 1-d Superfluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arovas, Daniel</p> <p>1998-03-01</p> <p>The rate for quantum nucleation of phase <span class="hlt">slips</span> past an impurity in a one-dimensional superfluid is computed. Real time evolution of the nonlinear Schrödinger equation shows that there is a critical velocity vc below which solutions are time-independent [1,2]; this is the regime of quantum phase <span class="hlt">slip</span> nucleation. We start with the Gross-Pitaevskii model in the presence of an impurity potential, and derive the Euclidean action for a space-time vortex-antivortex pair, which describes a phase <span class="hlt">slip</span> event. The action is computed as a function of the superfluid velocity v and the impurity potential width and depth.l [1] V. Hakim, Phys. Rev. E 55, 2835 (1997).l [1] J. A. Freire, D. P. Arovas, and H. Levine, Phys. Rev. Lett (in press, 1997).l</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S51D..02H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S51D..02H"><span id="translatedtitle">ETS and tidal stressing: Fault weakening after main <span class="hlt">slip</span> pulse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Houston, H.</p> <p>2013-12-01</p> <p>Time-varying stresses from solid Earth tides and ocean loading influence slow <span class="hlt">slip</span> (Hawthorne and Rubin, 2010) and, consequently, the frequency of occurrence and intensity of tremor during ETS episodes (Rubinstein et al., 2008). This relationship can illuminate changes in the mechanical response of the rupture surfaces(s) during <span class="hlt">slip</span> in ETS. I compare the influence of tidal loading when and after the propagating ETS <span class="hlt">slip</span> front (estimated by tremor density in time) ruptures the fault at a given spot. Using estimates of <span class="hlt">slip</span> fronts that I derived from tremor locations, I divide ETS tremor into two groups: that occurring within a day of the start of the inferred <span class="hlt">slip</span> front and that occurring over several days thereafter. The tremor catalog used contains 50K waveform cross-correlation locations of tremor in 7 large ETS in northern Cascadia between 2005 and 2012. I calculate normal, shear and volumetric stresses due to the Earth and ocean tides at numerous locations on the inferred rupture plane of the ETS following the method of Hawthorne and Rubin (2010). The Coulomb stress increment at each tremor time and location is compared with tremor occurrence for the two groups of tremor. Unreasonable results appear if the effective frictional coefficient mu > 0.2, and results are most 'reasonable' when mu is very near or equal to zero. Following passage of the main <span class="hlt">slip</span> pulse, tremor generation is notably more sensitive to tidal stressing. One kPa of encouraging tidal Coulomb stress boosts the occurrence of tremor after the main <span class="hlt">slip</span> pulse by about 50% above the average value, while the same amount of discouraging stress decreases the occurrence of such tremor by a similar factor. The greater the encouraging or discouraging stress, the greater the effect. In contrast, tremor in the main <span class="hlt">slip</span> pulse is much less affected by positive or negative tidal stresses. I interpret the greater sensitivity to tidal stressing of the tremor after the main <span class="hlt">slip</span> pulse as a measure of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/in0212.sheet.00006a/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/in0212.sheet.00006a/"><span id="translatedtitle">Arch & Chord <span class="hlt">Joint</span> Detail; Crossbracing Center <span class="hlt">Joint</span> Detail; Chord, ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Arch & Chord <span class="hlt">Joint</span> Detail; Crossbracing Center <span class="hlt">Joint</span> Detail; Chord, Panel Post, Tie & Diagonal Brace <span class="hlt">Joint</span> Detail; Chord, Panel Post, Tie & Crossbracing <span class="hlt">Joint</span> Detail - Dunlapsville Covered Bridge, Spanning East Fork Whitewater River, Dunlapsville, Union County, IN</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMMR33C2681J&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015AGUFMMR33C2681J&link_type=ABSTRACT"><span id="translatedtitle">Dynamically triggered <span class="hlt">slip</span> and sustained fault gouge instability associated with unique <span class="hlt">slip</span> behavior under laboratory shear conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, P. A.; Carmeliet, J.; Savage, H. M.; Scuderi, M.; Carpenter, B. M.; Guyer, R. A.; Daub, E. G.; Marone, C.</p> <p>2015-12-01</p> <p>We investigate dynamic-wave triggered <span class="hlt">slip</span> under laboratory shear conditions. The experiment is comprised of a 3-block system containing two gouge layers composed of glass beads and held in place by a fixed load in a bi-axial configuration. When the system is sheared under steady state conditions at loads from 3-8 MPa, stick-<span class="hlt">slip</span> exhibiting a characteristic recurrence time is observed. Under these load conditions, we find that shear failure may be instantaneously triggered by a brief dynamical wave if the system is in a critical shear-stress state, near failure. Dynamic triggering is only observed when the dynamic wave amplitude exceeds strains of 10^(-7). Following triggering, the gouge material remains in an unstable state for long periods of time as manifest by unique <span class="hlt">slip</span> characteristics not observed during spontaneous events: the measured physical characteristics—the gouge material strength recovery, the gouge layer thickness, the gouge shear modulus and the stick-<span class="hlt">slip</span> recurrence time recover over many stick-<span class="hlt">slip</span> cycles following triggering. This work suggests that faults must be critically stressed to trigger under dynamic conditions and that the recovery process following a dynamically triggered event differs from the recovery following a spontaneous event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70148036','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70148036"><span id="translatedtitle">Offset of latest pleistocene shoreface reveals <span class="hlt">slip</span> rate on the Hosgri strike-<span class="hlt">slip</span> fault, offshore central California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Johnson, Samuel Y.; Hartwell, Stephen R.; Dartnell, Peter</p> <p>2014-01-01</p> <p>The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐<span class="hlt">slip</span> fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265  m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral <span class="hlt">slip</span> rate of 2.6±0.9  mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This <span class="hlt">slip</span> rate indicates that the Hosgri system takes up the largest share of the strike‐<span class="hlt">slip</span> fault budget and is the most active strike‐<span class="hlt">slip</span> fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S41B2447C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S41B2447C"><span id="translatedtitle">Reduced Aftershock Productivity in Regions with Known Slow <span class="hlt">Slip</span> Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Collins, G.; Mina, A.; Richardson, E.; McGuire, J. J.</p> <p>2013-12-01</p> <p>Reduced aftershock activity has been observed in areas with high rates of aseismic <span class="hlt">slip</span>, such as transform fault zones and some subduction zones. Fault conditions that could explain both of these observations include a low effective normal stress regime and/or a high temperature, semi-brittle/plastic rheology. To further investigate the possible connection between areas of aseismic <span class="hlt">slip</span> and reduced aftershock productivity, we compared the mainshock-aftershock sequences in subduction zones where aseismic <span class="hlt">slip</span> transients have been observed to those of adjacent (along-strike) regions where no slow <span class="hlt">slip</span> events have been detected. Using the Advanced National Seismic System (ANSS) catalog, we counted aftershocks that occurred within 100 km and 14 days of 112 M>=5.0 slab earthquake mainshocks from January 1980 - July 2013, including 90 since January 2000, inside observed regions of detected slow <span class="hlt">slip</span>: south central Alaska, Cascadia, the Nicoya Peninsula (Costa Rica), Guerrero (Mexico), and the North Island of New Zealand. We also compiled aftershock counts from 97 mainshocks from areas adjacent to each of these regions using the same criteria and over the same time interval. Preliminary analysis of these two datasets shows an aftershock triggering exponent (alpha in the ETAS model) of approximately 0.8, consistent with previous studies of aftershocks in a variety of tectonic settings. Aftershock productivity for both datasets is less than that of continental earthquakes. Contrasting the two datasets, aftershock productivity inside slow <span class="hlt">slip</span> regions is lower than in adjacent areas along the same subduction zone and is comparable to that of mid-ocean ridge transform faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMPSo..94..257F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMPSo..94..257F"><span id="translatedtitle">Phase-field <span class="hlt">slip</span>-line theory of plasticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Freddi, Francesco; Royer-Carfagni, Gianni</p> <p>2016-09-01</p> <p>A variational approach to determine the deformation of an ideally plastic substance is proposed by solving a sequence of energy minimization problems under proper conditions to account for the irreversible character of plasticity. The flow is driven by the local transformation of elastic strain energy into plastic work on <span class="hlt">slip</span> surfaces, once that a certain energetic barrier for <span class="hlt">slip</span> activation has been overcome. The distinction of the elastic strain energy into spherical and deviatoric parts is used to incorporate in the model the idea of von Mises plasticity and isochoric plastic strain. This is a "phase field model" because the matching condition at the <span class="hlt">slip</span> interfaces is substituted by the evolution of an auxiliary phase field that, similar to a damage field, is unitary on the elastic phase and null on the yielded phase. The <span class="hlt">slip</span> lines diffuse in bands, whose width depends upon a material length-scale parameter. Numerical experiments on representative problems in plane strain give solutions with noteworthy similarities with the results from classical <span class="hlt">slip</span>-line field theory, but the proposed model is much richer because, accounting for elastic deformations, it can describe the formation of <span class="hlt">slip</span> bands at the local level, which can nucleate, propagate, widen and diffuse by varying the boundary conditions. In particular, the solution for a long pipe under internal pressure is very different from the one obtainable from the classical macroscopic theory of plasticity. For this case, the location of the plastic bands may be an insight to explain the premature failures that are sometimes encountered during the manufacturing process. This practical example enhances the importance of this new theory based on the mathematical sciences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAG...134..159S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAG...134..159S"><span id="translatedtitle">Back analysis of fault-<span class="hlt">slip</span> in burst prone environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sainoki, Atsushi; Mitri, Hani S.</p> <p>2016-11-01</p> <p>In deep underground mines, stress re-distribution induced by mining activities could cause fault-<span class="hlt">slip</span>. Seismic waves arising from fault-<span class="hlt">slip</span> occasionally induce rock ejection when hitting the boundary of mine openings, and as a result, severe damage could be inflicted. In general, it is difficult to estimate fault-<span class="hlt">slip</span>-induced ground motion in the vicinity of mine openings because of the complexity of the dynamic response of faults and the presence of geological structures. In this paper, a case study is conducted for a Canadian underground mine, herein called "Mine-A", which is known for its seismic activities. Using a microseismic database collected from the mine, a back analysis of fault-<span class="hlt">slip</span> is carried out with mine-wide 3-dimensional numerical modeling. A back analysis is conducted to estimate the physical and mechanical properties of the causative fracture or shear zones. One large seismic event has been selected for the back analysis to detect a fault-<span class="hlt">slip</span> related seismic event. In the back analysis, the shear zone properties are estimated with respect to moment magnitude of the seismic event and peak particle velocity (PPV) recorded by a strong ground motion sensor. The estimated properties are then validated through comparison with peak ground acceleration recorded by accelerometers. Lastly, ground motion in active mining areas is estimated by conducting dynamic analysis with the estimated values. The present study implies that it would be possible to estimate the magnitude of seismic events that might occur in the near future by applying the estimated properties to the numerical model. Although the case study is conducted for a specific mine, the developed methodology can be equally applied to other mines suffering from fault-<span class="hlt">slip</span> related seismic events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.S33B2546S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.S33B2546S"><span id="translatedtitle">Along Strike Variations in Episodic Tremor and <span class="hlt">Slip</span> Rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmalzle, G. M.; Creager, K. C.; Delbridge, B. G.; Wech, A.; Khazaradze, G.</p> <p>2012-12-01</p> <p>The geodetic signal due to Episodic Tremor and <span class="hlt">Slip</span> (ETS) along strike of the Cascadia Subduction Zone (CSZ) is much larger in Washington north of ~46°N than in Oregon from 2004 to 2011. Similarly, ETS recurrence in Cascadia increases from two years in Oregon to ~14 months near Puget Sound, Washington. Among the four seismically and geodetically detected ETS events that ruptured northern to central Oregon (June 2011, August 2009, July 2007 and November 2005), only the 2009 event ruptured from southern Puget Sound to central Oregon, crossing ~46°N. Seismically observed tremor and geodetic displacements are used to inspect the August 2009 ETS event. Elastic half-space models indicate interface <span class="hlt">slip</span> north of 45.6+0.3/-0.5°N is large (64 mm at 112° CCW from north) and reduces by ~52% (31 mm at 119° CCW from north) to the south. The moment magnitude is 6.8. We seek to understand why there is more apparent <span class="hlt">slip</span> in Washington than in Oregon for the 2009 event as well as for the average GPS displacement per year (sum of vector displacements of each ETS event since 2004 divided by GPS site duration of operation). We use an elastic half space model with GPS time series from the Pacific Northwest Geodetic Network (PANGA) and the Plate Boundary Observatory (PBO) to invert for the slow <span class="hlt">slip</span> rate and explore key model parameters such as the width of the <span class="hlt">slipping</span> zone, fault dip and depth to try to explain the apparent difference in average GPS displacement per year caused by ETS events. If the <span class="hlt">slip</span> deficit observed in Oregon is real, then how will it eventually be accommodated?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRB..11510301N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRB..11510301N"><span id="translatedtitle">On the transient behavior of frictional melt during seismic <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nielsen, S.; Mosca, P.; Giberti, G.; di Toro, G.; Hirose, T.; Shimamoto, T.</p> <p>2010-10-01</p> <p>In a recent work on the problem of sliding surfaces under the presence of frictional melt (applying in particular to earthquake fault dynamics), we derived from first principles an expression for the steady state friction compatible with experimental observations. Building on the expressions of heat and mass balance obtained in the above study for this particular case of Stefan problem (phase transition with a migrating boundary), we propose here an extension providing a full time-dependent solution (including the weakening transient after pervasive melting has started, the effect of eventual steps in velocity, and the final decelerating phase). A system of coupled equations is derived and solved numerically. The resulting transient friction and wear evolution yield a satisfactory fit (1) with experiments performed under variable sliding velocities (0.9-2 m s-1) and different normal stresses (0.5-20 MPa) for various rock types and (2) with estimates of <span class="hlt">slip</span> weakening obtained from observations on ancient seismogenic faults that host pseudotachylite (solidified melt). The model allows us to extrapolate the experimentally observed frictional behavior to large normal stresses representative of the seismogenic Earth crust (up to 200 MPa), high <span class="hlt">slip</span> rates (up to 9 m s-1), and cases where melt extrusion is negligible. Though weakening distance and peak stress vary widely, the net breakdown energy appears to be essentially independent of either <span class="hlt">slip</span> velocity or normal stress. In addition, the response to earthquakelike <span class="hlt">slip</span> can be simulated, showing a rapid friction recovery when <span class="hlt">slip</span> rate drops. We discuss the properties of energy dissipation, transient duration, velocity weakening, restrengthening in the decelerating final <span class="hlt">slip</span> phase, and the implications for earthquake source dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040013176&hterms=Temporal+Displacement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemporal%2BDisplacement','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040013176&hterms=Temporal+Displacement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemporal%2BDisplacement"><span id="translatedtitle">Possible Stick-<span class="hlt">Slip</span> Mechanism for Whillans Ice Stream</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bindschadler, Robert; King, Matt; Vornberger, Patricia</p> <p>2003-01-01</p> <p>Tidally-induced stick-<span class="hlt">slip</span> motion in the mouth of Whillans Ice Stream provides a unique natural experiment in ice-stream response behavior and from which we might learn a great deal about subglacial till properties and sub-ice-stream conditions. At the IGS Symposium on Fast Glacier Flow (Yakutat, 2002), we reported our observations of stick- <span class="hlt">slip</span> motion and demonstrated its synchronicity with tidal forcing. Recently, we have completed additional processing of our GPS data in differential mode. It reveals more details of the stick-<span class="hlt">slip</span> events and illustrates that within 30 seconds, the temporal interval of our data, the ice stream accelerates to a speed corresponding to a completely lubricated bed. While details of individual events vary, there seems to be strong evidence of an elastic rebound on the time scale of one hour following most events. This suggests the event involves the release of stored elastic strain energy in the ice. The similar displacements of events suggest further that till or subglacial hydrologic properties limit the amount of elastic strain released in any single event. We follow a line of reasoning that dilatant strengthening limits the <span class="hlt">slip</span> displacement and present model of the stick-<span class="hlt">slip</span> process. To match the observed delay between the peak ocean tide and stick-<span class="hlt">slip</span> events, our model includes a propagating pressure wave in the subglacial hydrologic system between the grounding line, where the rising tide first increases the subglacial water pressure and regions upstream where stored elastic strain increases the basal shear stress. This high-tide event is released when the increased water pressure reaches the region of increased shear stress. Dilatant strengthening stops the event by increasing pore volume and lowering the water pressure. Following this event, falling tide increases the normal forces, compresses the till and increases pore pressure again, leading to the second falling-tide event we observe every tidal cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040012981&hterms=Temporal+Displacement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemporal%2BDisplacement','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040012981&hterms=Temporal+Displacement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DTemporal%2BDisplacement"><span id="translatedtitle">Possible Stick-<span class="hlt">Slip</span> Mechanism for Whillans Ice Stream</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bindschadler, Robert; King, Matt; Vornberger, Patricia</p> <p>2003-01-01</p> <p>Tidally-induced stick-<span class="hlt">slip</span> motion in the mouth of Whillans Ice Stream provides a unique natural experiment in ice-stream response behavior and fiom which we might learn a great deal about subglacial till properties and sub-ice-stream conditions. At the IGS Symposium on Fast Glacier Flow (Yakutat, 2002), we reported our observations of stick- <span class="hlt">slip</span> motion and demonstrated its synchronicity with tidal forcing. Recently, we have completed additional processing of our GPS data in differential mode. It reveals more details of the stick-<span class="hlt">slip</span> events and illustrates that within 30 seconds, the temporal interval of our data, the ice stream accelerates to a speed corresponding to a completely lubricated bed. While details of individual events vary, there seems to be strong evidence of an elastic rebound on the time scale of one hour following most events. This suggests the event involves the release of stored elastic strain energy in the ice. The similar displacements of events suggest further that till or subglacial hydrologic properties limit the amount of elastic strain released in any single event. We follow a line of reasoning that dilatant strengthening limits the <span class="hlt">slip</span> displacement and present model of the stick-<span class="hlt">slip</span> process. To match the observed delay between the peak ocean tide and stick-<span class="hlt">slip</span> events, our model includes a propagating pressure wave in the subglacial hydrologic system between the grounding line, where the rising tide first increases the subglacial water pressure and regions upstream where stored elastic strain increases the basal shear stress. This high-tide event is released when the increased water pressure reaches the region of increased shear stress. Dilatant strengthening stops the event by increasing pore volume and lowering the water pressure. Following this event, falling tide increases the normal forces, compresses the till and increases pore pressure again, leading to the second falling-tide event we observe every tidal cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EL.....58..524P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EL.....58..524P"><span id="translatedtitle">Stick-<span class="hlt">slip</span> instability for viscous fingering in a gel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puff, N.; Debrégeas, G.; di Meglio, J.-M.; Higgins, D.; Bonn, D.; Wagner, C.</p> <p>2002-05-01</p> <p>The growth dynamics of an air finger injected in a visco-elastic gel (a PVA/borax aqueous solution) is studied in a linear Hele-Shaw cell. Besides the standard Saffman-Taylor instability, we observe—with increasing finger velocities—the existence of two new regimes: (a) a stick-<span class="hlt">slip</span> regime for which the finger tip velocity oscillates between 2 different values, producing local pinching of the finger at regular intervals; (b) a "tadpole" regime where a fracture-type propagation is observed. A scaling argument is proposed to interpret the dependence of the stick-<span class="hlt">slip</span> frequency with the measured rheological properties of the gel.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/6839267','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/6839267"><span id="translatedtitle"><span class="hlt">Joint</span> custody: preliminary impressions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Awad, G A</p> <p>1983-02-01</p> <p><span class="hlt">Joint</span> custody is currently a popular and debatable issue. It is felt that some of the controversy is due to the lack of agreement on a definition. Following some examples of the differences in personal and judicial definitions of <span class="hlt">joint</span> custody, a classification of custody is offered. Four types of custody arrangements are described: Absolute Sole Custody, Sole Custody, Non-Alternating <span class="hlt">Joint</span> Custody (disputed and undisputed) and Alternating <span class="hlt">Joint</span> Custody (disputed and undisputed). A critical review of the literature follows. Finally, clinical impressions about the two types of <span class="hlt">joint</span> custody are discussed. PMID:6839267</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS33B1055J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS33B1055J"><span id="translatedtitle">Offset of Latest Pleistocene Shoreface Reveals <span class="hlt">Slip</span> Rate on the Hosgri Strike-<span class="hlt">Slip</span> Fault, Offshore Central California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, S. Y.; Hartwell, S. R.; Dartnell, P.</p> <p>2014-12-01</p> <p>The Hosgri fault is the southern part of the regional Hosgri-San Gregorio dextral strike-<span class="hlt">slip</span> fault system, which extends primarily in the offshore region for about 400 km in central California. Between Morro Bay and San Simeon, high-resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by a ~265-m-wide slope interpreted as the shoreface of a relict sand spit that formed during a period of relatively slower sea-level rise (Younger Dryas stadial) in the latest Pleistocene. This sand spit crossed an embayment and connected a western fault-bounded bedrock peninsula and an eastern bedrock highland, a paleogeography similar to modern geomorphology along coastal segments of the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral <span class="hlt">slip</span> rate of 2.6 ± 0.9 mm/yr. Because the Hosgri fault locally includes an active western strand, and regionally converges with several other faults, this <span class="hlt">slip</span> rate should be considered a minimum for the Hosgri fault in central California and should not be applied for the entire Hosgri-San Gregorio fault system. This <span class="hlt">slip</span> rate indicates that the Hosgri system takes up the largest share of the strike-<span class="hlt">slip</span> fault budget and is the most active strike-<span class="hlt">slip</span> fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high-resolution bathymetry in earthquake-hazard characterization of active offshore faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004Tectp.383...45M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004Tectp.383...45M"><span id="translatedtitle"><span class="hlt">Slip</span> sense inversion on active strike-<span class="hlt">slip</span> faults in southwest Japan and its implications for Cenozoic tectonic evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maruyama, Tadashi; Lin, Aiming</p> <p>2004-05-01</p> <p>Analyses of deflected river channels, offset of basement rocks, and fault rock structures reveal that <span class="hlt">slip</span> sense inversion occurred on major active strike-<span class="hlt">slip</span> faults in southwest Japan such as the Yamasaki and Mitoke fault zones and the Median Tectonic Line (MTL). Along the Yamasaki and Mitoke fault zones, small-size rivers cutting shallowly mountain slopes and Quaternary terraces have been deflected sinistrally, whereas large-size rivers which deeply incised into the Mio-Pliocene elevated peneplains show no systematically sinistral offset or complicated hairpin-shaped deflection. When the sinistral offsets accumulated on the small-size rivers are restored, the large-size rivers show residual dextral deflections. This dextral offset sense is consistent with that recorded in the pre-Cenozoic basement rocks. S-C fabrics of fault gouge and breccia zone developed in the active fault zones show sinistral shear sense compatible with earthquake focal mechanisms, whereas those of the foliated cataclasite indicate a dextral shear sense. These observations show that the sinistral strike-<span class="hlt">slip</span> shear fabrics were overprinted on dextral ones which formed during a previous deformation phase. Similar topographic and geologic features are observed along the MTL in the central-eastern part of the Kii Peninsula. Based on these geomorphological and geological data, we infer that the <span class="hlt">slip</span> sense inversion occurred in the period between the late Tertiary and mid-Quaternary period. This strike-<span class="hlt">slip</span> inversion might result from the plate rearrangement consequent to the mid-Miocene Japan Sea opening event. This multidisciplinary study gives insight into how active strike-<span class="hlt">slip</span> fault might evolves with time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8118897','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8118897"><span id="translatedtitle">Temporomandibular <span class="hlt">joint</span> osteoarthrosis and temporomandibular <span class="hlt">joint</span> hypermobility.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dijkstra, P U; de Bont, L G; de Leeuw, R; Stegenga, B; Boering, G</p> <p>1993-10-01</p> <p>For studying the relationship between condylar hypermobility of the temporomandibular <span class="hlt">joint</span> (TMJ) and osteoarthrosis (OA), 13 patients with bilateral condylar hypermobility were evaluated clinically and radiographically, 30 years after non-surgical treatment. The evaluation included range of motion, <span class="hlt">joint</span> and muscle tenderness to palpation, <span class="hlt">joint</span> sounds and masticatory function. Radiographs of the TMJs were evaluated for the absence or presence of degenerative changes. The hypermobile group (HG) was compared with a control group (CG) (n = 13). The CG was evaluated in the same way as the HG. Statistics included t-tests (to compare ranges of motion in the HG over time and to compare ranges of motion in HG and CG), non-parametric tests (to compare tenderness of muscles and <span class="hlt">joints</span>, <span class="hlt">joint</span> sounds, masticatory function and radiographic changes over time in the HG). The tests were also used to compare the same variables between the HG and CG group. The groups' only difference was the presence of radiographic signs of OA. In the HG the number of <span class="hlt">joints</span> with radiographic degenerative changes increased significantly over time and was significantly higher than the CG. Clinically and functionally, the HG and CG did not differ. Therefore, it is concluded that TMJ hypermobility is a subsidiary factor in the development of TMJ OA. PMID:8118897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T42C..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T42C..01T"><span id="translatedtitle">The influence of <span class="hlt">slip</span> velocity and temperature on permeability during and after high-velocity fault <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanikawa, W.; Mukoyoshi, H.; Tadai, O.; Hirose, T.; Lin, W.</p> <p>2011-12-01</p> <p>Fluid transport properties in fault zones play an important role in dynamic processes during large earthquakes. If the permeability in a fault zone is low, high pore-fluid pressures caused by thermal pressurization (Sibson, 1973) or shear-induced compaction (Blanpied et al., 1992) can lead to an apparent reduction of fault strength. Changes in porosity and permeability of fault rocks within a fault zone during earthquakes and the subsequent progressive recovery of these properties may have a large influence on earthquake recurrence (Sleep and Blanpied, 1992). A rotary shear apparatus was used to investigate changes of fluid transport properties in a fault zone by real-time measurement of gas flow rates during and after shearing of hollow sandstone and granite cylinders at various <span class="hlt">slip</span> rates. Our apparatus measures permeability parallel to the <span class="hlt">slip</span> plane in both the <span class="hlt">slip</span> zone and wall rocks. In all cases, permeability decreased rapidly with an increase of friction, but recovered soon after <span class="hlt">slip</span>, reaching a steady state within several tens of minutes. The rate of reduction of permeability increased with increasing <span class="hlt">slip</span> velocity. Permeability did not recover to pre-<span class="hlt">slip</span> levels after low-velocity tests but recovered to exceed them after high-velocity tests. Frictional heating of gases at the <span class="hlt">slip</span> surface increased gas viscosity, which increased gas flow rate to produce an apparent permeability increase. The irreversible permeability changes of the low-velocity tests were caused by gouge formation due to wearing and smoothing of the <span class="hlt">slip</span> surface. The increase of permeability after high-velocity tests was caused by mesoscale fracturing in response to rapid temperature rise. Changes of pore fluid viscosity contributed more to changes of flow rate than did permeability changes caused by shear deformation, although test results from different rocks and pore fluids might be different. References Blanpied, M.L., Lockner, D.A., Byerlee, J.D., 1992. An earthquake mechanism</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7000857','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7000857"><span id="translatedtitle">Analysis of pinnate <span class="hlt">joints</span> in the Mount Desert Island granite: Implications for postintrusion kinematics in the coastal volcanic belt, Maine</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Engelder, T. )</p> <p>1989-06-01</p> <p>The mount desert Island granite is cut by fractures displaying one of four types of surface morphology: (1) smooth to undulatory; (2) stepped in the form of en echelon cracks; (3) striated with linear fibers; and (4) irregular with cataclastic grains. These surfaces belong to <span class="hlt">joints</span>, host fractures with pinnate <span class="hlt">joints</span>, reactivated <span class="hlt">joints</span> or fractures, and deformation bands (shear fractures), respectively. Pinnate <span class="hlt">joints</span>, like striations on slickensides, are structures indicative of the orientation of a the <span class="hlt">slip</span> vector and sense of shear on host fractures. Although fractures in the Mount Desert Island granite cluster into two major sets (N20{degree}W and N45{degree}E), host fractures with pinnate <span class="hlt">joints</span> and shear fractures favor the N45{degree}E orientation. A kinematic analysis of the pinnate <span class="hlt">joints</span> indicates a predominantly dextral strike-<span class="hlt">slip</span> sense of movement on northeast-trending fractures. This result agrees with previous work suggesting that a prominent postintrusion tectonic event in southeast Maine consisted of dextral strike-<span class="hlt">slip</span> motion on northeast-trending faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2649577','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2649577"><span id="translatedtitle">Problems and complications of <span class="hlt">slipped</span> capital femoral epiphysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Canale, S T</p> <p>1989-01-01</p> <p>In summary, epiphysiodesis, by either "pinning" or "pegging," seems to be necessary to further prevent displacement of the SCFE. To minimize complications, aggressive closed reduction, open reduction, pin penetration, and unnecessary drill holes should be avoided. Avascular necrosis and chondrolysis, the most frequent and devastating complications, appear to be related to the severity of the <span class="hlt">slip</span> and the type of treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=kinematics+AND+dynamic&pg=3&id=EJ757905','ERIC'); return false;" href="http://eric.ed.gov/?q=kinematics+AND+dynamic&pg=3&id=EJ757905"><span id="translatedtitle">Dynamic Action Units <span class="hlt">Slip</span> in Speech Production Errors</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goldstein, Louis; Pouplier, Marianne; Chen, Larissa; Saltzman, Elliot; Byrd, Dani</p> <p>2007-01-01</p> <p>In the past, the nature of the compositional units proposed for spoken language has largely diverged from the types of control units pursued in the domains of other skilled motor tasks. A classic source of evidence as to the units structuring speech has been patterns observed in speech errors--"<span class="hlt">slips</span> of the tongue". The present study reports, for…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1152..139W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1152..139W"><span id="translatedtitle">Diagnostics of Apparent Wall <span class="hlt">Slip</span> in Aqueous Polymer Solutions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wein, Ondřej; Tovčigrečko, Valentin V.; Sobolík, Václav; Večeř, Marek</p> <p>2009-07-01</p> <p>Two experimental methods, apparent-wall-<span class="hlt">slip</span> (AWS) rotational viscometry with "Morse-taper" sensors and electrodiffusion (ED) flow diagnostics with auto-calibrated friction probes, are used to study velocity profiles in aqueous solutions of high-molecular polysaccharides. By comparing the velocity data from the both methods, estimates are obtained of depleted layer thickness in dependence on wall shear stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22403213','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22403213"><span id="translatedtitle">Chaotic mixing in a planar, curved channel using periodic <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Garg, P.; Picardo, J. R.; Pushpavanam, S.</p> <p>2015-03-15</p> <p>We propose a novel strategy for designing chaotic micromixers using curved channels confined between two flat planes. The location of the separatrix between the Dean vortices, induced by centrifugal forces, is dependent on the location of the maxima of axial velocity. An asymmetry in the axial velocity profile can change the location of the separatrix. This is achieved physically by introducing <span class="hlt">slip</span> alternatingly at the top and bottom walls. This leads to streamline crossing and Lagrangian chaos. An approximate analytical solution of the velocity field is obtained using perturbation theory. This is used to find the Lagrangian trajectories of fluid particles. Poincare sections taken at periodic locations in the axial direction are used to study the extent of chaos. We study two microchannel designs, called circlet and serpentine, in which the Dean vortices in adjacent half cells are co-rotating and counter-rotating, respectively. The extent of mixing, at low Re and low <span class="hlt">slip</span> length, is shown to be greater in the serpentine case. Wide channels are observed to have much better mixing than tall channels; an important observation not made for separatrix flows till now. Eulerian indicators are used to gauge the extent of mixing, with varying <span class="hlt">slip</span> length, and it is shown that an optimum <span class="hlt">slip</span> length exists which maximizes the mixing in a particular geometry. Once the parameter space of relatively high mixing is identified, detailed variance computations are carried out to identify the detailed features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007JMiMi..17.2108B&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007JMiMi..17.2108B&link_type=ABSTRACT"><span id="translatedtitle">Microscale disk-induced gas displacement with and without <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blanchard, Danny; Ligrani, Phil</p> <p>2007-10-01</p> <p>Displacements of gas flows, both with and without <span class="hlt">slip</span>, are described for rotation-induced flows in a C-shaped fluid chamber passage formed between a rotating disk and a stationary surface, with a height h of 13.3 µm. Included are accommodation coefficients for the stationary smooth wall, smooth disk surface, medium rough disk surface rough disk surface. Flow rate and pressure rise magnitudes deduced using these accommodation coefficients, and simplified forms of the Navier-Stokes equations, are consistent with experimental data over rotational speeds of 200-1200 rpm, pressure increases of 0-400 Pa, net flow rates of 0-100 µl min-1, Knudsen numbers of 0.0056 and 0.0158, average roughness magnitudes of 0.01- 1.1 µm and working fluids of air and helium. All situations investigated consider a large roughness size compared to the molecular mean free path. For a particular normalized fluid chamber pressure rise P*, the normalized volumetric flow rate Q* with <span class="hlt">slip</span> is generally less than the value with no <span class="hlt">slip</span>. Lower P* magnitudes are also generally present at a particular value of Q*, in general, as the working fluid is changed from air to helium and the Knudsen number increases. The slopes of dimensional pressure variations with rotational speed decrease as disk surface roughness levels increase, as values of the accommodation coefficient decrease and, thus, as near-wall <span class="hlt">slip</span> velocity magnitudes increase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3926583','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3926583"><span id="translatedtitle">Micro-Vibration-Based <span class="hlt">Slip</span> Detection in Tactile Force Sensors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fernandez, Raul; Payo, Ismael; Vazquez, Andres S.; Becedas, Jonathan</p> <p>2014-01-01</p> <p>Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, <span class="hlt">slip</span> detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect <span class="hlt">slipping</span>, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect <span class="hlt">slipping</span> in other force sensors based on flexible parts. In particular, we show and compare the <span class="hlt">slip</span> detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor. PMID:24394598</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol4/pdf/CFR-2010-title49-vol4-sec229-115.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol4/pdf/CFR-2010-title49-vol4-sec229-115.pdf"><span id="translatedtitle">49 CFR 229.115 - <span class="hlt">Slip</span>/slide alarms.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel <span class="hlt">slip</span>/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title49-vol4/pdf/CFR-2014-title49-vol4-sec229-115.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title49-vol4/pdf/CFR-2014-title49-vol4-sec229-115.pdf"><span id="translatedtitle">49 CFR 229.115 - <span class="hlt">Slip</span>/slide alarms.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel <span class="hlt">slip</span>/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title49-vol4/pdf/CFR-2013-title49-vol4-sec229-115.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title49-vol4/pdf/CFR-2013-title49-vol4-sec229-115.pdf"><span id="translatedtitle">49 CFR 229.115 - <span class="hlt">Slip</span>/slide alarms.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel <span class="hlt">slip</span>/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1494243','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1494243"><span id="translatedtitle">Technique for Handling Cover <span class="hlt">Slips</span> Used in Cell Culture Systems *</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bowne, J. G.; Jochim, Michael M.</p> <p>1964-01-01</p> <p>A stainless steel, grooved rack was designed to handle large numbers of coverslips used in cell cultures. The rack separated and held the coverslips through the washing process and subsequent manipulations. <span class="hlt">Slips</span> washed by this method allowed consistently good cell sheets to grow with no signs of cytotoxicity to the cultures. ImagesFIGURE 1.FIGURE 2. PMID:17649500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24394598','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24394598"><span id="translatedtitle">Micro-vibration-based <span class="hlt">slip</span> detection in tactile force sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernandez, Raul; Payo, Ismael; Vazquez, Andres S; Becedas, Jonathan</p> <p>2014-01-03</p> <p>Tactile sensing provides critical information, such as force, texture, shape or temperature, in manipulation tasks. In particular, tactile sensors traditionally used in robotics are emphasized in contact force determination for grasping control and object recognition. Nevertheless, <span class="hlt">slip</span> detection is also crucial to successfully manipulate an object. Several approaches have appeared to detect <span class="hlt">slipping</span>, the majority being a combination of complex sensors with complex algorithms. In this paper, we deal with simplicity, analyzing how a novel, but simple, algorithm, based on micro-vibration detection, can be used in a simple, but low-cost and durable, force sensor. We also analyze the results of using the same principle to detect <span class="hlt">slipping</span> in other force sensors based on flexible parts. In particular, we show and compare the <span class="hlt">slip</span> detection with: (i) a flexible finger, designed by the authors, acting as a force sensor; (ii) the finger torque sensor of a commercial robotic hand; (iii) a commercial six-axis force sensor mounted on the wrist of a robot; and (iv) a fingertip piezoresistive matrix sensor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981JGR....86.4949M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981JGR....86.4949M"><span id="translatedtitle">Nonuniform seismic <span class="hlt">slip</span> rates along the Middle America Trench</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McNally, Karen C.; Minster, J. Bernard</p> <p>1981-06-01</p> <p>Revised estimates of seismic <span class="hlt">slip</span> rates along the Middle America Trench are lower on the average than plate convergence rates but match them locally (for example, Oaxaca). Along the Cocos-North American plate boundary this can be explained by nonuniformities in <span class="hlt">slip</span> at points of aseismic ridge or fracture zone subduction. For at least 81 yr (and possibly several hundred years), no major (Ms ≥ 7.5) shallow earthquake is known to have occurred near the Orozco Fracture Zone and Tehuantepec Ridge areas. Compared with the average recurrence periods for large earthquakes (33 ± 8 yr since 1898 and 35 ± 24 yr between 1542 and 1979), this suggests that either a large (M ≥ 8.4) event may be anticipated at such locations, or that these are points of aseismic subduction. Large coastal terraces and evidence suggesting tectonic uplift are found onshore near the Orozco Fracture zone. The larger discrepancy between plate convergence and seismic <span class="hlt">slip</span> rates along the Cocos-Carribbean plate boundary is more likely due to decoupling and downbending of the subducted plate. We used the limited statistical evidence available to characterize both spatial and temporal deficiencies in recent seismic <span class="hlt">slip</span>. The observations appear consistent with a possible forthcoming episode of more intense seismic activity. Based on a series of comparisons with carefully delineated aftershock zones, we conclude that the zones of anomalous seismic activity can be identified by a systematic, automated analysis of the worldwide earthquake catalog (mb ≥ 4).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7008028','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7008028"><span id="translatedtitle">Unified formulation for analysis of slopes with general <span class="hlt">slip</span> surface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Espinoza, R.D.; Bourdeau, P.L. . School of Civil Engineering); Muhunthan, B. . Dept. of Civil and Environmental Engineering)</p> <p>1994-07-01</p> <p>The general availability of computers has provided efficient means of assessing the stability of slopes using several analytical methods. However, the increased use of computers coupled with a lack of unified presentation of the various methods sometimes leads to conflicting results. It is shown that the current analytical methods can be grouped into three categories based on the hypotheses used to describe the internal forces, namely: (1) the direction of the internal forces; (2) the height of the line of thrust; and (3) the shape of the distribution function of the internal shear forces. An analytical framework incorporating this idea is presented to facilitate and unify slope stability analysis with general <span class="hlt">slip</span> surfaces. The study is a generalization of earlier work performed by Espinoza et al. for circular <span class="hlt">slip</span> surfaces. The framework incorporates most current methods of analysis. The analytical model is implemented in a computer program. The program was used to study several case examples. On this basis, key issues associated with the influence of the internal shear forces on the factor of safety, for both circular and general <span class="hlt">slip</span> failure surfaces, are discussed. It appears that for circular failure surfaces, even with heterogeneous soil stratigraphy the factor of safety is not affected by the choice of a particular hypothesis. On the contrary, for general <span class="hlt">slip</span> surfaces this choice may significantly affect the results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26764612','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26764612"><span id="translatedtitle">Wall <span class="hlt">slip</span> across the jamming transition of soft thermoresponsive particles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Divoux, Thibaut; Lapeyre, Véronique; Ravaine, Valérie; Manneville, Sébastien</p> <p>2015-12-01</p> <p>Flows of suspensions are often affected by wall <span class="hlt">slip</span>, that is, the fluid velocity v(f) in the vicinity of a boundary differs from the wall velocity v(w) due to the presence of a lubrication layer. While the <span class="hlt">slip</span> velocity v(s)=|v(f)-v(w)| robustly scales linearly with the stress σ at the wall in dilute suspensions, there is no consensus regarding denser suspensions that are sheared in the bulk, for which <span class="hlt">slip</span> velocities have been reported to scale as a v(s)∝σ(p) with exponents p inconsistently ranging between 0 and 2. Here we focus on a suspension of soft thermoresponsive particles and show that v(s)) actually scales as a power law of the viscous stress σ-σ(c), where σ(c) denotes the yield stress of the bulk material. By tuning the temperature across the jamming transition, we further demonstrate that this scaling holds true over a large range of packing fractions ϕ on both sides of the jamming point and that the exponent p increases continuously with ϕ, from p=1 in the case of dilute suspensions to p=2 for jammed assemblies. These results allow us to successfully revisit inconsistent data from the literature and pave the way for a continuous description of wall <span class="hlt">slip</span> above and below jamming. PMID:26764612</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012DPS....4410102P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012DPS....4410102P"><span id="translatedtitle">Strike-<span class="hlt">slip</span> Faulting On Ganymede, Now And Then</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pappalardo, Robert T.; Smith-Konter, B. R.; Cameron, M. E.; DeRemer-Keeney, L. C.; Nimmo, F.</p> <p>2012-10-01</p> <p>Strike-<span class="hlt">slip</span> tectonism is important to the structural development of Ganymede’s surface, and in the transition from dark to grooved terrain. Three distinct signatures of strike-<span class="hlt">slip</span> faulting are recognized [1]: (1) en echelon structures, (2) strike-<span class="hlt">slip</span> duplexes, and (3) laterally offset pre-existing features. As strike-<span class="hlt">slip</span> faulting progressed, en echelon fractures (in both dark and grooved terrains) merged to define en echelon swaths, which can become distinct tectonic domains. Three morphological categories of strike-<span class="hlt">slip</span> “duplexes” (spindle-shaped lensoid regions bounded by strike-<span class="hlt">slip</span> faults) occur, suggesting an evolutionary sequence from discontinuous fractures in dark terrain, to lensoid bounding structures, to lensoid regions with subparallel internal structure in grooved terrain. Ganymede’s 24 measured duplexes have an average length/width ratio of 2.4, on the low end of the terrestrial range [2]. Lateral offsets of pre-existing features betray the existence of some major strike-<span class="hlt">slip</span> faults: Dardanus Sulcus (13°W, 18°S) is displaced 45 km by a prominent NE-SW trending fault. We model Coulomb shear failure on Ganymede, considering nonsynchronous rotation (NSR), and diurnal stresses both for present (0.0013) and possible past high ( 0.05) eccentricity [3]. We adopt NSR period 0.14 Ma; Love numbers h2 = 1.52 and l2 = 0.38; Young’s modulus 9.3 GPa; Poisson’s ratio 0.33; and fault depth 2 km. NSR shear stress resolved along the Dardanus fault is 0.3 MPa, sufficient to induce failure to 1.4 km for friction coefficient 0.3. For past high eccentricity, diurnal stress would have modulated NSR stress by 100 kPa through Ganymede’s tidal cycle. This could have induced shear heating [4] and tidal walking [5], as modeled for Europa. References: [1] DeRemer and Pappalardo (2003), LPSC, 34, #2033; [2] Aydin and Nur (1982), Tectonics, 1, 91; [3] Showman and Malhotra (1997), Icarus, 127, 93; [4] Nimmo and Gaidos (2002), JGR, 107, 10.1029/2000JE001476; [5</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhDT........19I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhDT........19I"><span id="translatedtitle">Compositional, mechanical and hydrologic controls on fault <span class="hlt">slip</span> behavior</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ikari, Matt J.</p> <p></p> <p>In order to examine the roles of a variety of factors that are likely important in regulating the occurrence or lack of seismic <span class="hlt">slip</span>, I evaluate the results of numerous laboratory studies of fault behavior, focusing on the effects of fault mineralogy, mechanical effects, and interactions between fluids and faulting processes. More specifically, these experiments are designed to investigate the underlying mechanisms controlling the transition from aseismic <span class="hlt">slip</span> at shallow levels in the crust to seismic <span class="hlt">slip</span> at depth, known as the updip limit of the seismogenic zone. Results of laboratory experiments indicate that mineralogy of fault gouge is a major control on fault behavior. The clay mineral montmorillonite (smectite) has been noted for its potential effect on seismogenesis in subduction zones (as well as all faults in general) due to its ability to take up water in its crystal structure. Dehydration of montmorillonite tends to increase its frictional strength as well as increase its propensity for seismic <span class="hlt">slip</span>, as documented by a decrease in the frictional velocity dependence parameter a-b. However, the observed decrease in a-b is assisted by both increasing relative quartz percentage and increasing normal stress, implying that the onset of seismic behavior with increasing depth should not be attributed solely to smectite dehydration. Furthermore, clay-rich gouges in general, including those consisting of montmorillonite, illite, and chlorite, are both frictionally weak (mu < 0.35) and velocity-strengthening (frictionally stable, a-b > 0) at fluid-saturated conditions and effective normal stresses up to ˜60 MPa. Sheared gouges may also exhibit low fault-perpendicular permeability (k < 1x10-18), making them candidates to host high pore pressure. This indicates that faults containing granular, clay-rich gouges are unlikely to show seismic behavior, due their velocity-strengthening nature and stabilizing hydro-mechanical effects resulting from low permeability. In</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090022327','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090022327"><span id="translatedtitle">Airborne Antenna System for Minimum-Cycle-<span class="hlt">Slip</span> GPS Reception</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, C. Wayne</p> <p>2009-01-01</p> <p>A system that includes a Global Positioning System (GPS) antenna and associated apparatus for keeping the antenna aimed upward has been developed for use aboard a remote-sensing-survey airplane. The purpose served by the system is to enable minimum- cycle-<span class="hlt">slip</span> reception of GPS signals used in precise computation of the trajectory of the airplane, without having to restrict the airplane to maneuvers that increase the flight time needed to perform a survey. Cycle <span class="hlt">slip</span> signifies loss of continuous track of the phase of a signal. Minimum-cycle-<span class="hlt">slip</span> reception is desirable because maintaining constant track of the phase of the carrier signal from each available GPS satellite is necessary for surveying to centimeter or subcentimeter precision. Even a loss of signal for as short a time as a nanosecond can cause cycle <span class="hlt">slip</span>. Cycle <span class="hlt">slips</span> degrade the quality and precision of survey data acquired during a flight. The two principal causes of cycle <span class="hlt">slip</span> are weakness of signals and multipath propagation. Heretofore, it has been standard practice to mount a GPS antenna rigidly on top of an airplane, and the radiation pattern of the antenna is typically hemispherical, so that all GPS satellites above the horizon are viewed by the antenna during level flight. When the airplane must be banked for a turn or other maneuver, the reception hemisphere becomes correspondingly tilted; hence, the antenna no longer views satellites that may still be above the Earth horizon but are now below the equatorial plane of the tilted reception hemisphere. Moreover, part of the reception hemisphere (typically, on the inside of a turn) becomes pointed toward ground, with a consequent increase in received noise and, therefore, degradation of GPS measurements. To minimize the likelihood of loss of signal and cycle <span class="hlt">slip</span>, bank angles of remote-sensing survey airplanes have generally been limited to 10 or less, resulting in skidding or <span class="hlt">slipping</span> uncoordinated turns. An airplane must be banked in order to make</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ExFl...57..153J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ExFl...57..153J"><span id="translatedtitle">Direct measurement of wall <span class="hlt">slip</span> and <span class="hlt">slip</span> layer thickness of non-Brownian hard-sphere suspensions in rectangular channel flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jesinghausen, Steffen; Weiffen, Rene; Schmid, Hans-Joachim</p> <p>2016-09-01</p> <p>Wall <span class="hlt">slip</span> is a long-known phenomenon in the field of rheology. Nevertheless, the origin and the evolution are not completely clear yet. Regarding suspensions, the effect becomes even more complicated, because different mechanisms like pure <span class="hlt">slip</span> or <span class="hlt">slip</span> due to particle migration have to be taken into account. Furthermore, suspensions themselves show many flow anomalies and the isolation of <span class="hlt">slip</span> is complicated. In order to develop working physical models, further insight is necessary. In this work, we measured experimentally the wall <span class="hlt">slip</span> velocities of different highly filled suspensions in a rectangular slit die directly with respect to the particle concentration and the particle size. The <span class="hlt">slip</span> velocities were obtained using a particle image velocimetry (PIV) system. The suspensions consisting of a castor oil-cinnamon oil blend and PMMA particles were matched in terms of refractive indexes to appear transparent. Hereby, possible optical path lengths larger than 15 mm were achieved. The <span class="hlt">slip</span> velocities were found to be in a quadratic relation to the wall shear stress. Furthermore, the overall flow rate as well as the particle concentration has a direct influence on the <span class="hlt">slip</span>. Concerning the shear stress, there seem to be two regions of <span class="hlt">slip</span> with different physical characteristics. Furthermore, we estimated the <span class="hlt">slip</span> layer thickness directly from the velocity profiles and propose a new interpretation. The PIV technique is used to investigate the viscosity and implicit the concentration profile in the slit die. It is shown that the particle migration process is quite fast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAESc.124..260Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAESc.124..260Z"><span id="translatedtitle">The 3-D surface deformation, coseismic fault <span class="hlt">slip</span> and after-<span class="hlt">slip</span> of the 2010 Mw6.9 Yushu earthquake, Tibet, China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Guohong; Shan, Xinjian; Feng, Guangcai</p> <p>2016-07-01</p> <p>Using SAR interferometry on C band Envisat descending track and L band ALOS ascending track SAR images, respectively, we firstly obtain two coseismic deformation fields and one postseismic deformation of the 2010 Yushu earthquake, Tibet, China. In the meanwhile, we also obtain the azimuthal coseismic deformation of the Yushu event by Multi Aperture Interferometry (MAI) technique. With the 3 components of one-dimensional coseismic InSAR measurements, we resolve the complete 3-dimensional deformation of the 2010 Yushu event, which shows conformity and complexity to left lateral <span class="hlt">slip</span> mechanism. The horizontal deformation is basically consistent with a sinistral <span class="hlt">slip</span> event; whereas the vertical displacement does show certain level of complexity, which we argue is indicative of local fault geometry variation. Based on the InSAR data and elastic dislocation assumption, we invert for coseismic fault <span class="hlt">slip</span> and early after-<span class="hlt">slip</span> of the Yushu event. Our inversion results show major coseismic left lateral strike <span class="hlt">slip</span> with only minor thrust component. The after-<span class="hlt">slip</span> model fills most of the <span class="hlt">slip</span> gaps left by the coseismic fault <span class="hlt">slip</span> and finds a complementary <span class="hlt">slip</span> distribution to the coseismic fault <span class="hlt">slip</span>, which is a good indicator that future earthquake potential on the Yushu segment has been significantly reduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23598568','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23598568"><span id="translatedtitle">Private middle school parents' perspectives regarding school-located immunization programs (<span class="hlt">SLIPs</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Venkatesh, Sheila R; Acosta, Amy B; Middleman, Amy B</p> <p>2013-08-01</p> <p>The perspectives of parents of private middle school students regarding the use of school-located immunization programs (<span class="hlt">SLIPs</span>) are unknown. Parents of private middle school students in a large, urban setting were surveyed (N = 1,210) regarding their willingness to use <span class="hlt">SLIPs</span>. Analyses included frequencies and chi-square analyses. Data from prior work with public school parents were included for comparison. Of the 1,210 questionnaires, 219 were returned; only 19% of respondents reported they were willing to use a <span class="hlt">SLIP</span>, compared to 41% of public middle school parents. However, 54% of private school parents were willing to consider using <span class="hlt">SLIPs</span> for influenza vaccine, and 6% would use <span class="hlt">SLIPs</span> for human papillomavirus vaccine. Hispanic (Mexican) ethnicity (p = .014) was associated with greater willingness to utilize <span class="hlt">SLIPs</span>. Private middle school parents, in this sample, are relatively unwilling to utilize <span class="hlt">SLIPs</span> compared to public school parents. These data should be considered when implementing <span class="hlt">SLIPs</span> in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.S11E..08T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.S11E..08T"><span id="translatedtitle">Dynamic Mechanochemistry of Seismic <span class="hlt">Slip</span> -Nano Spherules Lubrication</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, H.; Chen, W.; Chen, Y.; Song, Y.; Ma, K.</p> <p>2007-12-01</p> <p>The Chelungpu fault, which was activated during 1999Chi-Chi Earthquake, had been drilled (Hole A, B and C) to recover the earthquake <span class="hlt">slip</span> zone materials. We present here the results of nano-scale observations for identified <span class="hlt">slip</span> zone materials (Ma, Tanaka et al., 2006) by using HR-TEM and TXM technique. Minimum size of grains observed under HR-TEM is 3 nm. The grain size distribution for grains larger than 100 nm in diameter follows the fractal law and grain shape is highly irregular. Grains smaller than100 nm show some specific characteristics, that is, smaller the grains, more the spherical shapes and more equi-granular. Thus, the grains smaller than 100 nm are no longer described by fractal distribution model. By SAD and EDX analysis under HR-TEM, the nano spherules are mainly composed of crystallized quartz associated with minor amounts of carbonates and amorphous materials. Results of observations lead following three conclusions, (1) nano spherules are not generated just by fracturing based on their shapes and grain size distributions. (2) nano spherules would compose viscous materials enveloping larger fractured grains from SEM observations. (3) Mica clay minerals and feldspars are disappeared in ultra-fine grained layer. This implies that chemical process of dissolution - elements dissipation - SiO2 precipitation occurred associated with mechanical fracturing. Therefore nano spherules would be generated through mechano-chemical process during co-seismic <span class="hlt">slip</span>. Dynamic shear strength drop by rapid <span class="hlt">slip</span> experimentsare and formation of gelled materials are recently reported. Large differences of ultra-fine products between previous reports and our observations are existence of nano spherules and their crystallinity. If the nano- spherules are generated during seismic <span class="hlt">slip</span>, dynamic weakening would be expected because mode of friction turns into rolling friction by huge amounts of equigranular and spherical grains. This may be alternative explanations for dynamic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....6898C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....6898C"><span id="translatedtitle">Major power law <span class="hlt">slip</span>-weakening in laboratory gouge friction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chambon, G.; Schmittbuhl, J.; Corfdir, A.</p> <p>2003-04-01</p> <p>We performed gouge-shearing experiments in a large-displacement ring-shear apparatus. The granular gouge (quartz sand) undergoes significant <span class="hlt">slip</span>-weakening over seismic-like distances (0.5 m) and minor velocity-weakening over microscopic length scales (100 μm). The reproducible decrease of gouge effective friction μ with shear displacement δ follows a power law: μ = μ_0 + A δ-β, with β = 0.4. Such a <span class="hlt">slip</span>-weakening process can be accounted for in an extended rate- and state-dependent friction law through a supplementary state variable. However, unlike classical state variables, the evolution law governing this new variable does not involve any characteristic length scale. Accordingly, <span class="hlt">slip</span>-weakening is found independent of gouge grain size. Careful checks were performed to insure that observed weakening constitutes a real rheological property of the gouge. Moreover, microscopic origin of the <span class="hlt">slip</span>-weakening has been investigated by means of a Correlation Image Velocimetry (CIV) technique applied to digital pictures of the sample. Most of the deformation appears localized in a 7 grain-wide, comminuted shear band. Nevertheless, CIV also reveals an intermittent, ongoing deformation outside this zone, whose magnitude slowly diminishes as shear displacement increases. This microscopic relaxation denotes a progressive decoupling between the shear zone and the bulk of the sample. Slow decrease of spatially-averaged shear strain <~ngleγrangle is well modeled by a hyperbolic law in displacement δ, without any characteristic length scale: <~ngleγrangle = γ_0 + a δ-1. We interpret the macroscopic <span class="hlt">slip</span>-weakening as a consequence of the observed decoupling at micro-scale. When extrapolated to faults, this result shows that decimetric weakening distances, frequently reported during earthquakes, can be produced by complex structuring processes inside the gouge layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GGG....17..442S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GGG....17..442S"><span id="translatedtitle">Dehydration-induced porosity waves and episodic tremor and <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Skarbek, Rob M.; Rempel, Alan W.</p> <p>2016-02-01</p> <p>Episodic tremor and <span class="hlt">slip</span> (ETS) along the subduction interface takes place where there is abundant evidence for elevated, near-lithostatic pore pressures, at sufficiently great depths (30-45 km) that chemical dehydration reactions must act as their dominant source. We simulate fluid and heat flow while tracking the location of a vertically oriented, one-dimensional column of material as it subducts through the slow <span class="hlt">slip</span> and tremor zone. The material in the column is transformed through a pressure-dependent and temperature-dependent dehydration reaction that we describe with a generalized nonlinear kinetic rate law. Column deformation is largely dominated by viscous creep, with a closure rate that depends linearly on porosity. This behavior causes the dehydration reaction to generate traveling porosity waves that transport increased fluid pressures within the slow <span class="hlt">slip</span> region. To explore the possibility that the observed periodicity of slow <span class="hlt">slip</span> and tremor in subduction zones can be explained by the migration of such porosity waves, we derive a dispersion relation that accurately describes our numerical results. We also obtain an expression for how the thickness of the dehydrating layer is expected to vary as a function of the parameters in the reaction rate law. Although the amplitudes of pore pressure perturbations rival those that are produced by known external forcings (e.g., tides or passing surface waves), our analysis suggests that given reasonable estimates of rock viscosity, permeabilities in the range 6.5×10-15 to 5×10-10 m2 are required for porosity wave trains to form at periods comparable to those of slow <span class="hlt">slip</span> and tremor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JGRB..11012407F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JGRB..11012407F"><span id="translatedtitle">Fusion by earthquake fault friction: Stick or <span class="hlt">slip</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fialko, Yuri; Khazan, Yakov</p> <p>2005-12-01</p> <p>Field observations of pseudotachylites and experimental studies of high-speed friction indicate that melting on a <span class="hlt">slipping</span> interface may significantly affect the magnitude of shear stresses resisting <span class="hlt">slip</span>. We investigate the effects of rock melting on the dynamic friction using theoretical models of shear heating that couple heat transfer, thermodynamics of phase transitions, and fluid mechanics. Results of laboratory experiments conducted at high (order of m/s) <span class="hlt">slip</span> velocities but low (order of MPa) normal stresses suggest that the onset of frictional melting may give rise to substantial increases in the effective fault strength, presumably due to viscous effects. However, extrapolation of the modeling results to in situ conditions suggests that the efficiency of viscous braking is significantly reduced under high normal and shear stresses. When transient increases in the dynamic fault strength due to fusion are not sufficient to inhibit <span class="hlt">slip</span>, decreases in the effective melt viscosity due to shear heating and melting of clasts drastically decrease the dynamic friction, resulting in a nearly complete stress drop ("thermal runaway"). The amount of energy dissipation associated with the formation of pseudotachylites is governed by the temperature dependence of melt viscosity and the average clast size in the fault gouge prior to melting. Clasts from a coarse-grained gouge have lower chances of survival in a pseudotachylite due to a higher likelihood of nonequilibrium overheating. The maximum temperature and energy dissipation attainable on the fault surface are ultimately limited by either the rock solidus (via viscous braking, and <span class="hlt">slip</span> arrest) or liquidus (via thermal runaway and vanishing resistance to sliding). Our modeling results indicate that the thermally activated fault strengthening and rupture arrest are unlikely to occur in most mafic protoliths but might be relevant for quartz-rich rocks, especially at shallow (<5-7 km) depths where the driving shear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.G52A..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.G52A..03M"><span id="translatedtitle">Rapid kinematic <span class="hlt">slip</span> inversion with regional geophysical data: towards site-specific tsunami intensity forecasts.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melgar, D.; Bock, Y.</p> <p>2014-12-01</p> <p>Rapid kinematic <span class="hlt">slip</span> inversions immediately following earthquake rupture is traditionally limited to teleseismic data and delayed many hours after large events. Regional data such as strong motion is difficult to incorporate quickly into images of the source process because baseline offsets render the long period portion of the recording unreliable. Recently it's been demonstrated that high rate GPS can potentially produce rapid <span class="hlt">slip</span> inversions for large events but is limited to very long periods. With an example of the 2011 M9 Tohoku-oki event we will demonstrate that the optimal on-the-fly combination of GPS and strong motion through a seismogeodetic Kalman filter produces reliable, broadband strong motion displacement and velocity waveforms that can be used for kinematic inversion. Through <span class="hlt">joint</span> inversion of displacement and velocity waveforms we will show that it is possible to obtain a broadband image of the source. Furthermore, we will also show that it is possible to include offshore geophysical observables such as sea surface measurements of tsunami propagation from GPS buoys and ocean bottom pressure sensors into the kinematic inversion. These data better constrain the shallowest part of rupture. We will use the time-dependent deformation of bathymetry predicted from the inversion results as an initial condition for tsunami propagation and inundation modeling. Through a comparison to post-event survey observations we will demonstrate that it is possible to reproduce the inundation pattern along the coastline in great detail and argue that detailed site-specific forecast of tsunami intensity is achievable with current methods and instrumentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70024800','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70024800"><span id="translatedtitle">Triggered surface <span class="hlt">slips</span> in the Salton Trough associated with the 1999 Hector Mine, California, earthquake</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rymer, M.J.; Boatwright, J.; Seekins, L.C.; Yule, J.D.; Liu, J.</p> <p>2002-01-01</p> <p>Surface fracturing occurred along the southern San Andreas, Superstition Hills, and Imperial faults in association with the 16 October 1999 (Mw 7.1) Hector Mine earthquake, making this at least the eighth time in the past 31 years that a regional earthquake has triggered <span class="hlt">slip</span> along faults in the Salton Trough. Fractures associated with the event formed discontinuous breaks over a 39-km-long stretch of the San Andreas fault, from the Mecca Hills southeastward to Salt Creek and Durmid Hill, a distance from the epicenter of 107 to 139 km. Sense of <span class="hlt">slip</span> was right lateral; only locally was there a minor (~1 mm) vertical component of <span class="hlt">slip</span>. Dextral <span class="hlt">slip</span> ranged from 1 to 13 mm. Maximum <span class="hlt">slip</span> values in 1999 and earlier triggered <span class="hlt">slips</span> are most common in the central Mecca Hills. Field evidence indicates a transient opening as the Hector Mine seismic waves passed the southern San Andreas fault. Comparison of nearby strong-motion records indicates several periods of relative opening with passage of the Hector Mine seismic wave-a similar process may have contributed to the field evidence of a transient opening. <span class="hlt">Slip</span> on the Superstition Hills fault extended at least 9 km, at a distance from the Hector Mine epicenter of about 188 to 196 km. This length of <span class="hlt">slip</span> is a minimum value, because we saw fresh surface breakage extending farther northwest than our measurement sites. Sense of <span class="hlt">slip</span> was right lateral; locally there was a minor (~1 mm) vertical component of <span class="hlt">slip</span>. Dextral <span class="hlt">slip</span> ranged from 1 to 18 mm, with the largest amounts found distributed (or skewed) away from the Hector Mine earthquake source. <span class="hlt">Slip</span> triggered on the Superstition Hills fault commonly is skewed away from the earthquake source, most notably in 1968, 1979, and 1999. Surface <span class="hlt">slip</span> on the Imperial fault and within the Imperial Valley extended about 22 km, representing a distance from the Hector Mine epicenter of about 204 to 226 km. Sense of <span class="hlt">slip</span> dominantly was right lateral; the right-lateral component of <span class="hlt">slip</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1136720','SCIGOV-DOEDE'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1136720"><span id="translatedtitle"><span class="hlt">Slip</span> and Dilation Tendency Analysis of the Patua Geothermal Area</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Faulds, James E.</p> <p>2013-12-31</p> <p>Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to <span class="hlt">slip</span> (<span class="hlt">slip</span> tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The <span class="hlt">slip</span> tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). <span class="hlt">Slip</span> and dilation were calculated using 3DStress (Southwest Research Institute). <span class="hlt">Slip</span> and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to <span class="hlt">slip</span> or dilate under ambient stress conditions to zero, a fault plane with no potential to <span class="hlt">slip</span> or dilate. <span class="hlt">Slip</span> and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum <span class="hlt">slip</span> tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to <span class="hlt">slip</span> or dilate. The resulting along-fault and fault-to-fault variation in <span class="hlt">slip</span> or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70000403','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70000403"><span id="translatedtitle">Paleomagnetic and structural evidence for oblique <span class="hlt">slip</span> in a fault-related fold, Grayback monocline, Colorado</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tetreault, J.; Jones, C.H.; Erslev, E.; Larson, S.; Hudson, M.; Holdaway, S.</p> <p>2008-01-01</p> <p>Significant fold-axis-parallel <span class="hlt">slip</span> is accommodated in the folded strata of the Grayback monocline, northeastern Front Range, Colorado, without visible large strike-<span class="hlt">slip</span> displacement on the fold surface. In many cases, oblique-<span class="hlt">slip</span> deformation is partitioned; fold-axis-normal <span class="hlt">slip</span> is accommodated within folds, and fold-axis-parallel <span class="hlt">slip</span> is resolved onto adjacent strike-<span class="hlt">slip</span> faults. Unlike partitioning strike-parallel <span class="hlt">slip</span> onto adjacent strike-<span class="hlt">slip</span> faults, fold-axis-parallel <span class="hlt">slip</span> has deformed the forelimb of the Grayback monocline. Mean compressive paleostress orientations in the forelimb are deflected 15??-37?? clockwise from the regional paleostress orientation of the northeastern Front Range. Paleomagnetic directions from the Permian Ingleside Formation in the forelimb are rotated 16??-42?? clockwise about a bedding-normal axis relative to the North American Permian reference direction. The paleostress and paleomagnetic rotations increase with the bedding dip angle and decrease along strike toward the fold tip. These measurements allow for 50-120 m of fold-axis-parallel <span class="hlt">slip</span> within the forelimb, depending on the kinematics of strike-<span class="hlt">slip</span> shear. This resolved horizontal <span class="hlt">slip</span> is nearly equal in magnitude to the ???180 m vertical throw across the fold. For 200 m of oblique-<span class="hlt">slip</span> displacement (120 m of strike <span class="hlt">slip</span> and 180 m of reverse <span class="hlt">slip</span>), the true shortening direction across the fold is N90??E, indistinguishable from the regionally inferred direction of N90??E and quite different from the S53??E fold-normal direction. Recognition of this deformational style means that significant amounts of strike <span class="hlt">slip</span> can be accommodated within folds without axis-parallel surficial faulting. ?? 2008 Geological Society of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S53C4522C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S53C4522C"><span id="translatedtitle">Nonvolcanic Tremors and Intraslab Fluid Migration in Guerrero, Mexico, During Slow <span class="hlt">Slip</span> Transients</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cruz-Atienza, V. M.; Husker, A. L.; Villafuerte, C. D.; Caballero, E.; Legrand, D.; Kostoglodov, V.</p> <p>2014-12-01</p> <p>Observations in different subduction zones have suggested that overpressured fluids close to the plate interface may be related to the origin of nonvolcanic tremors (NVT) and low frequency earthquakes (LFE). One condition for a causal relationship to exist between fluids and such seismicity is their spatial collocation. Fluids at nearly lithostatic pressures within the top few kilometers of the oceanic crust have been inferred in several subduction zones, including the province of Guerrero, Mexico. However, NVT hypocentral depths in this region have been poorly resolved so that casualty could not even be tested as a hypothesis. In this work, we report NVT relocations from a 3-year-catalog in Guerrero that includes the period of the Slow <span class="hlt">Slip</span> Earthquake (SSE) of 2006. We used a new location technique called the "Tremor Energy and Polarization" (TREP) method (Cruz-Atienza et al., JGR, 2014), which <span class="hlt">jointly</span> determines the source location and focal mechanism of sustained tremor signals by simultaneously inverting (1) the energy spatial distribution, (2) the energy spatial derivatives, and (3) the azimuthal direction of the particle motion polarization ellipsoid. In agreement with previous works, NVT epicentral locations concentrate between 200 and 230 km from the trench and then migrate ~40 km trenchward during the occurrence of the SSE. However, unlike earlier investigations, most NVT hypocenters lie at 43 km depth near the plate interface and have subparallel rake angles to the Cocos plate convergence direction. These results are consistent with independent locations and mechanisms of LFE in the region and allow us to examine the casualty hypothesis mentioned above. Poroelastic modeling of fluid transport during two SSEs in Guerrero (Villafuerte and Cruz-Atienza, AGU, 2014) show that fluids migrate towards the spots where this seismicity occurs with maximum velocities between 10-3 and 10-9 km/day, which are more than 3 orders of magnitude smaller than the LFE</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S31A2711S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S31A2711S"><span id="translatedtitle">Acoustic properties of the full spectrum of stick-<span class="hlt">slip</span> events from stable sliding to dynamic rupture: insights on the mechanics of slow earthquakes and transient fault <span class="hlt">slip</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scuderi, M. M.; Marone, C.; Tinti, E.; Di Stefano, G.; Collettini, C.</p> <p>2015-12-01</p> <p>Seismic and geodetic observations show that fault <span class="hlt">slip</span> occurs via a spectrum of behaviors that include slow earthquakes and tectonic tremor. These phenomena have been observed in a variety of tectonic environments worldwide, however the underlying processes are poorly understood. Here we report on lab experiments on simulated fault gouge. We used the double direct shear configuration and varied the loading system stiffness (k) to produce the full spectrum of stick-<span class="hlt">slip</span> behaviors, with durations ranging from 10-3 to 1 second. We measured frictional rheology and elastic wave properties throughout the stick-<span class="hlt">slip</span> cycle for slow and fast events. When the loading stiffness is greater than the fault zone critical rheologic stiffness (kc) we observe stable frictional sliding. For k≈kc we document emergent slow-<span class="hlt">slip</span> events from steady shear. When kc>k we observe audible stick-<span class="hlt">slip</span>. Stick <span class="hlt">slip</span> stress drop and event duration vary systematically as a function of the ratio k/kc. For slow-<span class="hlt">slip</span> events, p-wave velocity (Vp) begins to decrease prior to the stress drop and the maximum <span class="hlt">slip</span> velocity during failure coincides with the largest drop in Vp. Dynamic stick-<span class="hlt">slip</span> events do not show precursory changes in Vp prior to failure. We find that fault creep and precursory changes in wave properties vary systematically with stick-<span class="hlt">slip</span> event duration, with slower events showing larger precursory changes. In general, Vp begins to decrease prior to failure and drops abruptly as <span class="hlt">slip</span> velocity accelerates to a peak value. The drop in Vp appears to be larger during dynamic stick-<span class="hlt">slip</span> than for slow-<span class="hlt">slip</span> events. Our results suggest that slow earthquakes and transient fault <span class="hlt">slip</span> are governed by the same frictional processes as dynamic stick-<span class="hlt">slip</span> and represent a continuum in the spectrum of fault <span class="hlt">slip</span>. We show that fault gouge elastic properties evolve during the pre-seismic stage of slow-<span class="hlt">slip</span>, which could provide an important means of assessing short term seismic hazard.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27554487','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27554487"><span id="translatedtitle">[Total temporomandibular <span class="hlt">joint</span> prostheses].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zwetyenga, N; Amroun, S; Wajszczak, B-L; Moris, V</p> <p>2016-09-01</p> <p>The temporomandibular <span class="hlt">joint</span> (TMJ) is probably the most complex human <span class="hlt">joint</span>. As in all <span class="hlt">joints</span>, its prosthetic replacement may be indicated in selected cases. Significant advances have been made in the design of TMJ prostheses during the last three decades and the indications have been clarified. The aim of our work was to make an update on the current total TMJ total <span class="hlt">joint</span> replacement. Indications, contraindications, prosthetic components, advantages, disadvantages, reasons for failure or reoperation, virtual planning and surgical protocol have been exposed. PMID:27554487</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70029416','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70029416"><span id="translatedtitle">Constraints on fault <span class="hlt">slip</span> rates of the southern California plate boundary from GPS velocity and stress inversions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Becker, T.W.; Hardebeck, J.L.; Anderson, G.</p> <p>2005-01-01</p> <p>We use Global Positioning System (GPS) velocities and stress orientations inferred from seismicity to invert for the distribution of <span class="hlt">slip</span> on faults in the southern California plate-boundary region. Of particular interest is how long-term <span class="hlt">slip</span> rates are partitioned between the Indio segment of the San Andreas fault (SAF), the San Jacinto fault (SJF) and the San Bernardino segment of the SAE We use two new sets of constraints to address this problem. The first is geodetic velocities from the Southern California Earthquake Center's (SCEC) Crustal Motion Map (version 3 by Shen et al.), which includes significantly more data than previous models. The second is a regional model of stress-field orientations at seismogenic depths, as determined from earthquake focal mechanisms. While GPS data have been used in similar studies before, this is the first application of stress-field observations to this problem. We construct a simplified model of the southern California fault system, and estimate the interseismic surface velocities using a backslip approach with purely elastic strain accumulation, following Meade et al. In addition, we model the stress orientations at seismogenic depths, assuming that crustal stress results from the loading of active faults. The geodetically derived stressing rates are found to be aligned with the stress orientations from seismicity. We therefore proceed to invert simultaneously GPS and stress observations for <span class="hlt">slip</span> rates of the faults in our network. We find that the regional patterns of crustal deformation as imaged by both data sets can be explained by our model, and that <span class="hlt">joint</span> inversions lead to better constrained <span class="hlt">slip</span> rates. In our preferred model, the SJF accommodates ???15 mm yr-1 and the Indio segment of the SAF ???23 mm yr-1 of right-lateral motion, accompanied by a low <span class="hlt">slip</span> rate on the San Bernardino segment of the SAF 'Anomalous' fault segments such as around the 1992 Mw = 7.3 Landers surface rupture can be detected. There, observed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720021232','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720021232"><span id="translatedtitle">The liquid metal <span class="hlt">slip</span> ring experiment for the communications technology satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lovell, R. R.</p> <p>1972-01-01</p> <p>The experiment is designed to demonstrate liquid metal <span class="hlt">slip</span> ring (LMSR) performance in a space environment. An evaluation was made of the features of the LMSR where improvement in performance over conventional <span class="hlt">slip</span> rings was expected. The primary measurements to be made in the experiment will allow a determination of the <span class="hlt">slip</span> ring electrical resistance, between ring insulation and ring cleanliness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70043471','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70043471"><span id="translatedtitle">An integrated perspective of the continuum between earthquakes and slow-<span class="hlt">slip</span> phenomena</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Peng, Zhigang; Gomberg, Joan</p> <p>2010-01-01</p> <p>The discovery of slow-<span class="hlt">slip</span> phenomena has revolutionized our understanding of how faults accommodate relative plate motions. Faults were previously thought to relieve stress either through continuous aseismic sliding, or as earthquakes resulting from instantaneous failure of locked faults. In contrast, slow-<span class="hlt">slip</span> events proceed so slowly that <span class="hlt">slip</span> is limited and only low-frequency (or no) seismic waves radiate. We find that slow-<span class="hlt">slip</span> phenomena are not unique to the depths (tens of kilometres) of subduction zone plate interfaces. They occur on faults in many settings, at numerous scales and owing to various loading processes, including landslides and glaciers. Taken together, the observations indicate that slowly <span class="hlt">slipping</span> fault surfaces relax most of the accrued stresses through aseismic <span class="hlt">slip</span>. Aseismic motion can trigger more rapid <span class="hlt">slip</span> elsewhere on the fault that is sufficiently fast to generate seismic waves. The resulting radiation has characteristics ranging from those indicative of slow but seismic <span class="hlt">slip</span>, to those typical of earthquakes. The mode of seismic <span class="hlt">slip</span> depends on the inherent characteristics of the fault, such as the frictional properties. Slow-<span class="hlt">slip</span> events have previously been classified as a distinct mode of fault <span class="hlt">slip</span> compared with that seen in earthquakes. We conclude that instead, <span class="hlt">slip</span> modes span a continuum and are of common occurrence.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3222R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3222R"><span id="translatedtitle">Jelly Quakes - Characteristics of periodic <span class="hlt">slip</span> events in an analog model of strike <span class="hlt">slip</span> seismotectonics using ballistic gelatin.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rudolf, Michael; Rosenau, Matthias; Oncken, Onno</p> <p>2016-04-01</p> <p>Large lithospheric strike-<span class="hlt">slip</span> faults, such as the San-Andreas Fault, North-Anatolian Fault, or the Tancheng-Lujiang Faultzone, are major sources of seismic hazard. The interplay of complex 3D-geometry and displacement style along the fault, coupled with a varying rheological layering makes it very difficult to model these faults on all relevant timescales. Here we present a novel experimental approach to model intra- and interplate strike-<span class="hlt">slip</span> faults using a physical/ analog model. We model earthquakes as a stick-<span class="hlt">slip</span> process, following a rate-and-state frictional law, with glass beads as granular material within a molded fault zone. Crustal elasticity is introduced by using ballistic gelatin (30 w%, pig skin) as analog material. Furthermore, the low-strength and viscous deep crust below 15 km depth, is modeled using a viscoelastic silicone oil (PDMS-G30M). The layered model crust floats on sugar syrup and is compressed in pure shear vice configuration. We monitor the compressive force along with surface kinematics from optical image correlation. The fault is oriented at 45° to the compression direction imposing ideal strike-<span class="hlt">slip</span> kinematics onto it. After an initial loading phase the model shows periodic <span class="hlt">slip</span> events occurring alongside with creep on the fault. Using digital image correlation, surface displacement maps are obtained which are similar to those of natural earthquakes. Coseismic displacement along strike is showing a similar bell-shaped distribution as for natural faults. Furthermore, the recurrence intervals and stress drops are scalable to the natural prototype. The modeling results are combined with numerical rate-and-state models using physical parameters from the experiment. This enables us to explore a wide range of parameters and to draw connections between the parameters that control the behavior of seismic and aseismic fault systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1136717','SCIGOV-DOEDE'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1136717"><span id="translatedtitle"><span class="hlt">Slip</span> and Dilation Tendency Analysis of the Tuscarora Geothermal Area</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p>Faulds, James E.</p> <p>2013-12-31</p> <p>Critically stressed fault segments have a relatively high likelihood of acting as fluid flow conduits (Sibson, 1994). As such, the tendency of a fault segment to <span class="hlt">slip</span> (<span class="hlt">slip</span> tendency; Ts; Morris et al., 1996) or to dilate (dilation tendency; Td; Ferrill et al., 1999) provides an indication of which faults or fault segments within a geothermal system are critically stressed and therefore likely to transmit geothermal fluids. The <span class="hlt">slip</span> tendency of a surface is defined by the ratio of shear stress to normal stress on that surface: Ts = τ / σn (Morris et al., 1996). Dilation tendency is defined by the stress acting normal to a given surface: Td = (σ1-σn) / (σ1-σ3) (Ferrill et al., 1999). <span class="hlt">Slip</span> and dilation were calculated using 3DStress (Southwest Research Institute). <span class="hlt">Slip</span> and dilation tendency are both unitless ratios of the resolved stresses applied to the fault plane by ambient stress conditions. Values range from a maximum of 1, a fault plane ideally oriented to <span class="hlt">slip</span> or dilate under ambient stress conditions to zero, a fault plane with no potential to <span class="hlt">slip</span> or dilate. <span class="hlt">Slip</span> and dilation tendency values were calculated for each fault in the focus study areas at, McGinness Hills, Neal Hot Springs, Patua, Salt Wells, San Emidio, and Tuscarora on fault traces. As dip is not well constrained or unknown for many faults mapped in within these we made these calculations using the dip for each fault that would yield the maximum <span class="hlt">slip</span> tendency or dilation tendency. As such, these results should be viewed as maximum tendency of each fault to <span class="hlt">slip</span> or dilate. The resulting along-fault and fault-to-fault variation in <span class="hlt">slip</span> or dilation potential is a proxy for along fault and fault-to-fault variation in fluid flow conduit potential. Stress Magnitudes and directions Stress field variation within each focus area was approximated based on regional published data and the world stress database (Hickman et al., 2000; Hickman et al., 1998 Robertson-Tait et al., 2004; Hickman and Davatzes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4999M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4999M"><span id="translatedtitle">Analysis of the slow <span class="hlt">slip</span> events of Guerrero, Mexico: implications for numerical modeling.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maury, Julie; Aochi, Hideo; Radiguet, Mathilde</p> <p>2014-05-01</p> <p>Guerrero, in Mexico, is one of the subduction zones where long term slow <span class="hlt">slip</span> events (SSEs) have been observed recurrently. Understanding the mechanics of these events is important to determine their role in the seismic cycle. SSEs in Guerrero have been found to have the same characteristics, along the interface of subduction, as classical earthquakes but with much longer <span class="hlt">slip</span> time (around a year) and lower stress drop (0.1 MPa). We investigate the <span class="hlt">slip</span> models of the Guerrero SSEs of 2006 and 2009 (Radiguet et al., JGR 2012). The kinematic <span class="hlt">slip</span> models have been determined by inversion of GPS time series using two different methods. From these <span class="hlt">slip</span> histories, the constitutive relation between stress and <span class="hlt">slip</span> (or <span class="hlt">slip</span> rate) on each subfault is determined. Analytical Green functions are used to calculate the shear stress in a homogeneous, elastic, isotropic medium. Whatever the kinematic <span class="hlt">slip</span> modeling method used, a clear <span class="hlt">slip</span> weakening law can be retrieved over the whole <span class="hlt">slipping</span> area. While some spatial variation in the parameters of the <span class="hlt">slip</span> weakening law is observed, a mean value of about 0.1 m for the <span class="hlt">slip</span> weakening distance and 2.5 kJ/m2 for the fracture energy can be extracted on each subfault. Moreover the <span class="hlt">slip</span>-weakening rate seems quite homogeneous (around 1 MPa/m), and this is roughly the same as the value found in coseismic processes. The yield stress is of the order of 0.01 MPa, a low value compared to a stress drop of 0.1 MPa. The stress-<span class="hlt">slip</span> rate relationship presents a loop trajectory coherent with the one observed in classical earthquakes. The results of these analyses are used to numerically model the Guerrero SSEs. The aim is to reproduce the <span class="hlt">slip</span> pattern using the mechanical laws determined in the study of the <span class="hlt">slip</span> model. If a simple <span class="hlt">slip</span> weakening law, with parameters found above, is used, we observe a rapid progress of the crack-like <span class="hlt">slip</span> area. This is different from the observation of the migration of localized <span class="hlt">slip</span>. So a slowing mechanism</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S31A2720H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S31A2720H"><span id="translatedtitle">Spatial and Temporal Comparisons of Tremor and Slow <span class="hlt">Slip</span> in Cascadia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, K.; Houston, H.; Schmidt, D. A.</p> <p>2015-12-01</p> <p>Tremor is often thought to be a proxy for <span class="hlt">slip</span> during ETS events and has been shown to have a relatively abrupt updip boundary, implying an abrupt updip limit of <span class="hlt">slip</span>. However, as shown by Houston (AGU abstract, 2012) and Hall and Houston (AGU abstract, 2014), <span class="hlt">slip</span> inferred from GPS extended updip of the seismically-detected tremor in the 2010 M6.8 and 2012 M6.7 ETS events. If <span class="hlt">slip</span> extending updip of tremor is a persistent phenomena, tremor cannot be directly used as a proxy for <span class="hlt">slip</span>. Following the methods used on the 2010 and 2012 ETS event, we found that the August 2009 ETS around Portland, OR also showed <span class="hlt">slip</span> updip of tremor. Principal Component Analysis was implemented to automatically select the direction and magnitude of the maximum displacement vector. Our Green's functions use the Okada formulation of buried rectangular faults in a halfspace for a grid of 8x8 km subfaults based on the McCrory slab model. We then performed static inversions with 2nd order Tikhonov regularization to find <span class="hlt">slip</span> on the fault surface. We also compared two different inversions for 2009, one where <span class="hlt">slip</span> was allowed on a broad regional grid and a tremor-restricted inversion (TRI) where <span class="hlt">slip</span> was restricted to subfaults in which tremor occurred. We found the 2009 ETS event released the equivalent of a M6.8 in <span class="hlt">slip</span>. We also found that, as in the previous ETSs, the TRI forced up to 10 cm of <span class="hlt">slip</span> to the updip edge of the grid, which is exceeds the amount of plate convergence expected in the inter-ETS periods and is therefore physically unsustainable over several ETS events. The excess <span class="hlt">slip</span> along the updip edge in the TRI models also suggests that the geodetic data prefer <span class="hlt">slip</span> with a larger footprint than the spatial pattern of tremor, and supports our conclusion that tremor does not represent all of the <span class="hlt">slip</span> during an ETS event. We see consistent and clear spatial relationship between tremor and <span class="hlt">slip</span> with some <span class="hlt">slip</span> occurring updip of tremor. Our static inversions show where <span class="hlt">slip</span> is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S23B2282W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S23B2282W"><span id="translatedtitle">Modeling of Slow <span class="hlt">Slip</span> Events at the Hikurangi Subduction Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, C. A.; Wallace, L. M.; Beavan, R. J.; Lohman, R. B.; Ellis, S. M.; Marson-Pidgeon, K.; Eberhart-Phillips, D. M.; Reyners, M.; Henrys, S. A.; Bell, R. E.</p> <p>2011-12-01</p> <p>Slow <span class="hlt">slip</span> events (SSEs) occur along nearly the entire Hikurangi subduction margin adjacent to the North Island, New Zealand. Long duration (1-2 years), deep (40- 60 km depth), large events (equivalent to Mw ~7.0) occur at the southern Hikurangi margin, while shallow (10-15 km depth), short (1-2 weeks), smaller events (equivalent to Mw ~6.5) occur at the northern and central Hikurangi margin. A recently-initiated shallow event (Castle Point) lies further to the south than previous shallow events and appears to be rupturing a portion of the plate interface that was previously thought to be locked. Since 2000, three major slow <span class="hlt">slip</span> events have been identified at the southern Hikurangi margin; the 2003 Kapiti SSE, the 2004/2005 Manawatu SSE, and the 2007/2008 Kapiti SSE (which ended in early 2009). A repeat of the 2004/2005 Manawatu event is presently underway. In some cases, these SSEs may have triggered moderate seismicity within the subducting Pacific plate (e.g., Reyners and Bannister, 2007). To date, all of the inferred <span class="hlt">slip</span> distributions for the SSEs have been obtained using elastic half-space dislocation models. Numerous recent studies of coseismic displacement fields have shown that variations in elastic properties and surface topography can influence the predicted deformation. In our initial work, we used a finite element model to evaluate the influence of material property variations on the predicted surface deformation field. Elastic properties were assigned based on a seismic velocity model, and <span class="hlt">slip</span> distributions inferred from an elastic half-space model were applied. When compared to the elastic half- space model, we found that the heterogeneous models generally predict larger amounts of surface deformation, indicating that the half-space models may be overestimating the amount of <span class="hlt">slip</span>. As the next phase in our study, we are using finite element models that include material property variations and topography to generate Green's functions for use in an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T43A2631L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T43A2631L"><span id="translatedtitle">Patterns of Seismic and Aseismic <span class="hlt">Slip</span> on Heterogeneous Faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, Y.; Ampuero, J. P.</p> <p>2013-12-01</p> <p>Geological studies of exhumed faults and seismological observations reveal interesting aspects of fault heterogeneity. We thus carried numerical studies to explore the implications of fault heterogeneity on the organization of seismicity and transient aseismic <span class="hlt">slip</span>. Our quasi-dynamic, continuum models are based on laboratory derived rate-and-state friction with heterogeneity introduced by spatial distributions of characteristic <span class="hlt">slip</span> distance (Dc). We considered two types of faults, a simple strike-<span class="hlt">slip</span> fault and a typical subduction fault; and two types of spatial distribution of Dc, a model with uniformly random log Dc distribution, and a hierarchical model of asperities with self-similar power-law asperity size distribution and Dc value proportional to asperity size. Our systematic study shows that by varying the distribution of Dc value, we are able to reproduce a wide variety of macroscopic fault behaviors ranging from characteristic seismic events to steady-<span class="hlt">slip</span>. For different combinations of minimum and maximum Dc values on a fault we simulated multiple earthquake cycles with a total duration long enough to characterize the general behavior of the fault: characteristic (regularly repeating events that break the whole fault), non-characteristic (events with a range of magnitudes, in some cases with a complex but repeating pattern), aseismic transients and steady <span class="hlt">slip</span>. We found that non-characteristic seismicity behavior occurs only over a relatively narrow range of Dc distributions. We extended our study in this regime and observed complex sequences of seismic events ranging over two orders of magnitude of seismic moments. We generated a synthetic catalog containing over 10,000 events and studied their source scaling relations. The catalog shows a transition in the moment magnitude (M0) - rupture area (A) scaling, from M0~A3/2 at low magnitudes to M0~A at large magnitudes, controlled by the effect of the finite seismogenic depth. Our modeling provides</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP41C0935M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP41C0935M"><span id="translatedtitle">Mechanics of Sheeting <span class="hlt">Joints</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martel, S. J.</p> <p>2015-12-01</p> <p>Physical breakdown of rock across a broad scale spectrum involves fracturing. In many areas large fractures develop near the topographic surface, with sheeting <span class="hlt">joints</span> being among the most impressive. Sheeting <span class="hlt">joints</span> share many geometric, textural, and kinematic features with other <span class="hlt">joints</span> (opening-mode fractures) but differ in that they are (a) discernibly curved, (b) open near the topographic surface, and (c) form subparallel to the topographic surface. Where sheeting <span class="hlt">joints</span> are geologically young, the surface-parallel compressive stresses are typically several MPa or greater. Sheeting <span class="hlt">joints</span> are best developed beneath domes, ridges, and saddles; they also are reported, albeit rarely, beneath valleys or bowls. A mechanism that accounts for all these associations has been sought for more than a century: neither erosion of overburden nor high lateral compressive stresses alone suffices. Sheeting <span class="hlt">joints</span> are not accounted for by Mohr-Coulomb shear failure criteria. Principles of linear elastic fracture mechanics, together with the mechanical effect of a curved topographic surface, do provide a basis for understanding sheeting <span class="hlt">joint</span> growth and the pattern sheeting <span class="hlt">joints</span> form. Compressive stresses parallel to a singly or doubly convex topographic surface induce a tensile stress perpendicular to the surface at shallow depths; in some cases this alone could overcome the weight of overburden to open sheeting <span class="hlt">joints</span>. If regional horizontal compressive stresses, augmented by thermal stresses, are an order of magnitude or so greater than a characteristic vertical stress that scales with topographic amplitude, then topographic stress perturbations can cause sheeting <span class="hlt">joints</span> to open near the top of a ridge. This topographic effect can be augmented by pressure within sheeting <span class="hlt">joints</span> arising from water, ice, or salt. Water pressure could be particularly important in helping drive sheeting <span class="hlt">joints</span> downslope beneath valleys. Once sheeting <span class="hlt">joints</span> have formed, the rock sheets between</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70047852','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70047852"><span id="translatedtitle">Probabilistic estimates of surface coseismic <span class="hlt">slip</span> and afterslip for Hayward fault earthquakes</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Aagaard, Brad T.; Lienkaemper, James J.; Schwartz, David P.</p> <p>2012-01-01</p> <p>We examine the partition of long‐term geologic <span class="hlt">slip</span> on the Hayward fault into interseismic creep, coseismic <span class="hlt">slip</span>, and afterslip. Using Monte Carlo simulations, we compute expected coseismic <span class="hlt">slip</span> and afterslip at three alinement array sites for Hayward fault earthquakes with nominal moment magnitudes ranging from about 6.5 to 7.1. We consider how interseismic creep might affect the coseismic <span class="hlt">slip</span> distribution as well as the variability in locations of large and small <span class="hlt">slip</span> patches and the magnitude of an earthquake for a given rupture area. We calibrate the estimates to be consistent with the ratio of interseismic creep rate at the alinement array sites to the geologic <span class="hlt">slip</span> rate for the Hayward fault. We find that the coseismic <span class="hlt">slip</span> at the surface is expected to comprise only a small fraction of the long‐term geologic <span class="hlt">slip</span>. The median values of coseismic <span class="hlt">slip</span> are less than 0.2 m in nearly all cases as a result of the influence of interseismic creep and afterslip. However, afterslip makes a substantial contribution to the long‐term geologic <span class="hlt">slip</span> and may be responsible for up to 0.5–1.5 m (median plus one standard deviation [S.D.]) of additional <span class="hlt">slip</span> following an earthquake rupture. Thus, utility and transportation infrastructure could be severely impacted by afterslip in the hours and days following a large earthquake on the Hayward fault that generated little coseismic <span class="hlt">slip</span>. Inherent spatial variability in earthquake <span class="hlt">slip</span> combined with the uncertainty in how interseismic creep affects coseismic <span class="hlt">slip</span> results in large uncertainties in these <span class="hlt">slip</span> estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813519C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813519C"><span id="translatedtitle">Microstructural evolution from stable sliding to fast stick <span class="hlt">slip</span>: insights from rock deformation experiments on quartz</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Collettini, Cristiano; Scuderi, Marco M.; Viti, Cecilia; Marone, Chris</p> <p>2016-04-01</p> <p>Inferring microstructural evolution and associated fault <span class="hlt">slip</span> behaviour along natural and/or experimental faults is a long-standing problem in fault mechanics. For example, does grain-size reduction and shear localization facilitate earthquake <span class="hlt">slip</span> or vice versa? We have sheared granular layers of quartz gouge in a double direct shear configuration using a biaxial apparatus. We varied loading stiffness and applied normal stresses to produce a spectrum of <span class="hlt">slip</span> modes from stable sliding at 10 μm/s, slow stick-<span class="hlt">slip</span> (average <span class="hlt">slip</span> velocity 100 μm/s) and fast stick <span class="hlt">slip</span> (average <span class="hlt">slip</span> velocity 4 mm/s). At the end of the experiments we collected the experimental fault rocks for microstructural investigations. Additional samples were collected from control experiments to investigate shear fabric development and microstructural features before the onset of stick-<span class="hlt">slip</span> instabilities. We investigated the role of normal stress and stick-<span class="hlt">slip</span> properties, including <span class="hlt">slip</span> velocity, in determining fault zone microstructural features. Ranging from stable sliding to fast stick-<span class="hlt">slip</span> we observe a progressive localization of deformation along fault parallel boundary shear planes. Only during fast stick-<span class="hlt">slip</span> is the deformation localized along continuous, thin (1-2 microns wide), boundary parallel shear planes. The shear zones are composed of nanograins dispersed within a patchy matrix. We conducted TEM analyses to characterize these materials. In experiments at the same normal stress, fast stick-<span class="hlt">slip</span> results in localized shear zones and fabric with nanograins whereas for stable sliding the microstructure does not show a significant grain size reduction and localization. Our results indicate that the fault rheological properties and fault <span class="hlt">slip</span> behaviour, ranging from stable to unstable <span class="hlt">slip</span>, plays a significant role in shear localization and fault zone fabric development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.T31F..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.T31F..01S"><span id="translatedtitle">Silicification Strengthening and Non-Localization of <span class="hlt">Slip</span> in Dilational Sites Along Strike-<span class="hlt">Slip</span> Faults, Mt Isa Inlier, Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sibson, R. H.; Ghisetti, F. C.; Begbie, M. J.</p> <p>2006-12-01</p> <p>Sets of late- or post-orogenic brittle strike-<span class="hlt">slip</span> faults disrupt the complex of subgreenschist to amphibolite facies metasediments and metavolcanics intruded by granites that make up the Proterozoic Mt Isa inlier of NW Queensland, Australia. Subvertical dextral faults with offsets <25 km generally strike NE-SW to NNE- SSW and mutually cross-cut a conjugate set of sinistral faults striking NW-SE to NNW-SSE. Together, they define a regional stress field with horizontal maximum compression, σ1, at an azimuth of ~100° and horizontal σ3 trending ~010°. The strike-<span class="hlt">slip</span> faults are recessive except in dilational sites where upwelling hydrothermal fluids have led to silicification of the cataclastic shear zones which then form prominent blade-like ridges sometimes extending for kilometres across the semi-arid terrain. Silicification textures suggest the faults have been exhumed from epizonal boiling environments (<1-2 km depth). The mineralized fault segments include sinuous releasing bends where the fault trace is deflected <10° as well as more abrupt dilational stepovers linking en echelon fault segments. Particularly noticeable is the change from recessive to upstanding wall-like character of the faults as they approach dilational stepovers linking en echelon fault segments. Where recessive, limited outcrop is consistent with standard models of brittle infrastructure with a fault core localized in a damage zone tens of metres in width. By contrast, along the dilational segments the faults are defined by one or more subvertical cataclastic shear zones (CSZ), commonly ranging up to 10 m or so in thickness, made up of silicified microbreccia-cataclasite containing a mixture of protolith and hydrothermal vein fragments. The composite fabric of the CSZ includes: (1) local grain-size banding developed subparallel to margins; (2) irregular quartz-cemented breccias of varying dilation; (3) innumerable subvertical, cm - dm quartz-veins of variable planarity lying</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760000274&hterms=joint+compound&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Djoint%2Bcompound','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760000274&hterms=joint+compound&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Djoint%2Bcompound"><span id="translatedtitle">Compound solder <span class="hlt">joints</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Batista, R. I.; Simonson, R. B.</p> <p>1976-01-01</p> <p>Joining technique prevents contamination, may be used to join dissimilar metal tubes, minimizes fluid and gas entrapment, expedites repairs, and can yield <span class="hlt">joints</span> having leakage rates less than 0.000001 standard cubic cm He/min. Components of <span class="hlt">joint</span> are solder sleeve, two solder rings, Teflon sleeve, and tubing to be joined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870000424&hterms=scaffold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dscaffold','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870000424&hterms=scaffold&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dscaffold"><span id="translatedtitle">Wedge <span class="hlt">Joints</span> for Trusses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wood, Kenneth E.</p> <p>1987-01-01</p> <p>Structure assembled rapidly with simple hand tools. Proposed locking wedge <span class="hlt">joints</span> enable rapid assembly of lightweight beams, towers, scaffolds, and other truss-type structures. Lightweight structure assembled from tubular struts joined at nodes by wedge pins fitting into mating slots. <span class="hlt">Joint</span> assembled rapidly by seating wedge pin in V-shaped slots and deforming end of strut until primary pawl engages it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011IJCEM..12....1D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011IJCEM..12....1D"><span id="translatedtitle">Development of a Specific Finite Element for Timber <span class="hlt">Joint</span> Modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Descamps, Thierry; Van Parys, Laurent; Datoussaïd, Sélim</p> <p>2011-01-01</p> <p>Widely used for light frame structures or for heavy laminated wood structures, dowel-type fasteners are the most commonly used kind of connectors in timber construction. The purpose of this work is to develop a tool for the semi-rigid analysis and design of such <span class="hlt">joints</span>. Firstly, interests and approaches described in literature for the semi-rigid modeling of timber plane frames are summarized. Secondly, for a better understanding of the problem, the main characteristics of wood used as a structural material are presented. Finally, a method for an efficient study of <span class="hlt">joints</span> built with dowel-type fasteners is proposed and developed. This method consists of the introduction of a specific finite element called "Finite Semi-Rigid Element (FSRE)" between the ends of the <span class="hlt">jointed</span> members. This <span class="hlt">joint</span> element consists of two nodes, each with three degrees of freedom. These nodes will be tied with common beamelements during the FE analysis. The stiffness of the FSRE is computed from the geometry of the <span class="hlt">joints</span> and embedding stiffness of all fasteners, along and perpendicular to the grain. The embedding characteristics of fasteners are defined with help of their experimental load-<span class="hlt">slip</span> curves (fitted with Foschi's models) leading finally to the resolution of a FE non-linear problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70018964','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70018964"><span id="translatedtitle">Self-healing <span class="hlt">slip</span> pulses in dynamic rupture models due to velocity-dependent strength</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Beeler, N.M.; Tullis, T.E.</p> <p>1996-01-01</p> <p>Seismological observations of short <span class="hlt">slip</span> duration on faults (short rise time on seismograms) during earthquakes are not consistent with conventional crack models of dynamic rupture and fault <span class="hlt">slip</span>. In these models, the leading edge of rupture stops only when a strong region is encountered, and <span class="hlt">slip</span> at an interior point ceases only when waves from the stopped edge of <span class="hlt">slip</span> propagate back to that point. In contrast, some seismological evidence suggests that the duration of <span class="hlt">slip</span> is too short for waves to propagate from the nearest edge of the ruptured surface, perhaps even if the distance used is an asperity size instead of the entire rupture dimension. What controls <span class="hlt">slip</span> duration, if not dimensions of the fault or of asperities? In this study, dynamic earthquake rupture and <span class="hlt">slip</span> are represented by a propagating shear crack. For all propagating shear cracks, <span class="hlt">slip</span> velocity is highest near the rupture front, and at a small distance behind the rupture front, the <span class="hlt">slip</span> velocity decreases. As pointed out by Heaton (1990), if the crack obeys a negative <span class="hlt">slip</span>-rate-dependent strength relation, the lower <span class="hlt">slip</span> velocity behind the rupture front will lead to strengthening that further reduces the velocity, and under certain circumstances, healing of <span class="hlt">slip</span> can occur. The boundary element method of Hamano (1974) is used in a program adapted from Andrews (1985) for numerical simulations of mode II rupture with two different velocity-dependent strength functions. For the first function, after a <span class="hlt">slip</span>-weakening displacement, the crack follows an exponential velocity-weakening relation. The characteristic velocity V0 of the exponential determines the magnitude of the velocity-dependence at dynamic velocities. The velocity-dependence at high velocity is essentially zero when V0 is small and the resulting <span class="hlt">slip</span> velocity distribution is similar to <span class="hlt">slip</span> weakening. If V0 is larger, rupture propagation initially resembles <span class="hlt">slip</span>-weakening, but spontaneous healing occurs behind the rupture front. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70018612','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70018612"><span id="translatedtitle"><span class="hlt">Slip</span> history of the 1995 Kobe, Japan, earthquake determined from strong motion, teleseismic, and geodetic data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wald, D.J.</p> <p>1996-01-01</p> <p>Near-source ground motions, teleseismic body waveforms, and geodetic displacements produced by the 1995 Kobe, Japan, earthquake have been used to determine the spatial and temporal dislocation pattern on the faulting surfaces. Analysis of the <span class="hlt">slip</span> model indicates that the ground motions recorded within the severely damaged region of Kobe originated from the region of relatively low <span class="hlt">slip</span> (about 1 m) deep beneath Kobe and not from the shallow, higher <span class="hlt">slip</span> regions (about 3 m) beneath Aqaji Island. Although the <span class="hlt">slip</span> was relatively low beneath Kobe, the combined effects of source rupture directivity, a short <span class="hlt">slip</span> duration, and site amplification conspired to generate very damaging ground motions within the city.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27036475','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27036475"><span id="translatedtitle">Soft matter dynamics: Accelerated fluid squeeze-out during <span class="hlt">slip</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hutt, W; Persson, B N J</p> <p>2016-03-28</p> <p>Using a Leonardo da Vinci experimental setup (constant driving force), we study the dependency of lubricated rubber friction on the time of stationary contact and on the sliding distance. We slide rectangular rubber blocks on smooth polymer surfaces lubricated by glycerol or by a grease. We observe a remarkable effect: during stationary contact the lubricant is only very slowly removed from the rubber-polymer interface, while during <span class="hlt">slip</span> it is very rapidly removed resulting (for the grease lubricated surface) in complete stop of motion after a short time period, corresponding to a <span class="hlt">slip</span> distance typically of order only a few times the length of the rubber block in the sliding direction. For an elastically stiff material, poly(methyl methacrylate), we observe the opposite effect: the sliding speed increases with time (acceleration), and the lubricant film thickness appears to increase. We propose an explanation for the observed effect based on transient elastohydrodynamics, which may be relevant also for other soft contacts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144l4903H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144l4903H"><span id="translatedtitle">Soft matter dynamics: Accelerated fluid squeeze-out during <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hutt, W.; Persson, B. N. J.</p> <p>2016-03-01</p> <p>Using a Leonardo da Vinci experimental setup (constant driving force), we study the dependency of lubricated rubber friction on the time of stationary contact and on the sliding distance. We slide rectangular rubber blocks on smooth polymer surfaces lubricated by glycerol or by a grease. We observe a remarkable effect: during stationary contact the lubricant is only very slowly removed from the rubber-polymer interface, while during <span class="hlt">slip</span> it is very rapidly removed resulting (for the grease lubricated surface) in complete stop of motion after a short time period, corresponding to a <span class="hlt">slip</span> distance typically of order only a few times the length of the rubber block in the sliding direction. For an elastically stiff material, poly(methyl methacrylate), we observe the opposite effect: the sliding speed increases with time (acceleration), and the lubricant film thickness appears to increase. We propose an explanation for the observed effect based on transient elastohydrodynamics, which may be relevant also for other soft contacts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.7586S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.7586S"><span id="translatedtitle">A Novel Algorithm for Cycle <span class="hlt">Slip</span> Detection and Repair</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sezen, U.; Arikan, F.</p> <p>2012-04-01</p> <p>Accurate and reliable estimation of ionospheric parameters are very important for correct functioning of communication, navigation and positioning satellite systems. In recent years, dual-frequency GPS receivers are widely used for estimation of Total Electron Content (TEC), which is defined as the line integral of the electron density along a ray path. Since both electron density and TEC are functions of solar, geomagnetic, gravitational and seismic activity, any disturbance along the ray path can be detected using GPS receiver observables. It is observed that, with the development of recent sophisticated receivers, disruptions due to the receiver antenna, hardware or outside obstructions are minimized. Most of the observed sudden disturbances are signal phase lock losses due to ionosphere. These sudden phase shifts are named as cycle <span class="hlt">slips</span> and if not corrected, they may lead to positioning errors or incorrect TEC estimates. There are many methods in the literature that deal with cycle <span class="hlt">slips</span> and their repairs, yet these methods are not matured to detect all kinds of cycle <span class="hlt">slips</span>. Most algorithms require double differencing, and/or complicated Kalman Filters, Wavelet transforms, Neural Network models, and integration of external INS systems. In this study, we propose a fast and efficient algorithm for identifying the cycle <span class="hlt">slips</span> on individual observables, classifying them for future investigations and finally repairing them for more accurate and reliable TEC estimates. The algorithm traces the pseudorange and phase observables and computes the geometry free combinations of L4 and P4. The sudden disturbances on L1, L2, P1, C1 and P2 are classified and noted for further use. Most of the cases, the disruptions are on phase observables, yet for a few occasions, a sudden disturbance is also observed on pseudorange observables. The algorithm, then, checks the epoch section where P4 exists continually. When a disruption on L1 or L2 occurs, it becomes evident on L4. When P4</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987JAP....61.1034Y&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987JAP....61.1034Y&link_type=ABSTRACT"><span id="translatedtitle"><span class="hlt">Slip</span> effect for thin liquid film on a rotating disk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yanagisawa, Masahiro</p> <p>1987-02-01</p> <p>A flow for thin liquid films on rotating disks has been theoretically and experimentally studied. Liquid depletion behavior during a spin-coating process is calculated by solving the Navier-Stokes equation, taking into account interface <span class="hlt">slip</span> between liquid and disk. Excellent agreement is seen between the model prediction and experimental data. According to observed depletion behavior on thin liquid films for various spin-coating parameters, half life falls off at the inverse square of rotational speed, and increases when viscosity increases, although the increasing rate falls off. The interface <span class="hlt">slip</span>, represented as an external friction coefficient, is thermodynamically explained by the different (Δrc) in critical surface tension (rc) values between the liquid and the disk, which will be proportional to the solubility parameter. An infinite external friction coefficient, representing nonslip flow, may be given, when Δrc is zero. Spin-off experiments for liquids of various rc values, prepared by differing surface treatments, support this consideration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.S42C0183R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.S42C0183R"><span id="translatedtitle">Fault Zone Drainage, Heating and Melting During Earthquake <span class="hlt">Slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rempel, A. W.; Rice, J. R.; Jacques, L. M.</p> <p>2003-12-01</p> <p>The expansion of pore water caused by frictional heating during large crustal events provides a powerful weakening mechanism (Sibson, 1973; Lachenbruch, 1980). It may explain the magnitude of seismically inferred fracture energy and aspects of its variation with increased <span class="hlt">slip</span> (Abercrombie and Rice, 2003; Rice et al., 2003; Rice, this section, 2003). The weakening is mediated by the effects of fluid transport, which are sensitive to the permeability structure of the fault zone and its modification by damage induced by the passing rupture front (Poliakov et al., 2002), as well as by the increase in pore pressure itself. Higher permeabilities allow partial drainage to occur, so that enough strength remains for the heat generated to cause partial melting of the fault gouge at large enough <span class="hlt">slip</span>. We use recent field and laboratory data for fluid transport through pressurized fault gouge (e.g. Lockner et al., 2000; Wibberley and Shimamoto, 2003) to motivate models for drainage and melting during earthquake <span class="hlt">slip</span>. A dramatic illustration of the role of drainage is provided by an idealized model in which we assume that a freshly damaged, highly permeable region extends right up to a localized shear zone of thickness ho=5 mm, with fixed porosity n and much lower permeability k. At 7 km depth, for n=0.02 and k=10-19 m2, the <span class="hlt">slip</span> distance required to reach the onset of melting at 750oC is approximately 0.4 m for a constant friction coefficient of f=0.6. At 14 km depth, for n=0.01 and k=10-20 m2, the same temperature is reached after only 0.1 m of <span class="hlt">slip</span>. Yet more efficient drainage might occur due to the permeability increases that accompany reductions in the effective stress, so that even more rapid temperature increases would be predicted. For example, with ten times higher k, melting begins after 0.1 m <span class="hlt">slip</span> at 7 km depth and just 0.05 m at 14 km. At onset of melting the high melt viscosity impedes further drainage and, with increasing melt fraction, inter-particle contact is</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5390..147C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5390..147C"><span id="translatedtitle">Wheel <span class="hlt">slip</span> control of ABS using ER valve pressure modulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Seung-Bok; Cho, Myung-Soo; Kim, Yong-Il; Choi, Young-Tai; Wereley, Norman M.</p> <p>2004-07-01</p> <p>This paper presents a wheel <span class="hlt">slip</span> control via sliding mode controller for a new anti-lock brake system (ABS) of a passenger vehicle using electrorheological (ER) valve pressure modulator. The principal design parameters of the ER valves and hydraulic booster are appropriately determined by considering braking pressure variation during ABS operation. An electrically controllable pressure modulator using the ER valves is then constructed and its governing equations are derived. Subsequently, the pressure control performance of the new pressure modulator is experimentally evaluated. The governing equations of motion for a quarter car wheel model are derived and the sliding mode controller is formulated for wheel <span class="hlt">slip</span> control. Hardware in the loop simulation (HILS) for braking performance evaluation is undertaken in order to demonstrate the effectiveness of the proposed ABS associated with the ER valve pressure modulator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18755967','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18755967"><span id="translatedtitle">Magmatically triggered slow <span class="hlt">slip</span> at Kilauea Volcano, Hawaii.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brooks, Benjamin A; Foster, James; Sandwell, David; Wolfe, Cecily J; Okubo, Paul; Poland, Michael; Myer, David</p> <p>2008-08-29</p> <p>We demonstrate that a recent dike intrusion probably triggered a slow fault-<span class="hlt">slip</span> event (SSE) on Kilauea volcano's mobile south flank. Our analysis combined models of Advanced Land Observing Satellite interferometric dike-intrusion displacement maps with continuous Global Positioning System (GPS) displacement vectors to show that deformation nearly identical to four previous SSEs at Kilauea occurred at far-field sites shortly after the intrusion. We model stress changes because of both secular deformation and the intrusion and find that both would increase the Coulomb failure stress on possible SSE <span class="hlt">slip</span> surfaces by roughly the same amount. These results, in concert with the observation that none of the previous SSEs at Kilauea was directly preceded by intrusions but rather occurred during times of normal background deformation, suggest that both extrinsic (intrusion-triggering) and intrinsic (secular fault creep) fault processes can lead to SSEs. PMID:18755967</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JAP...110a4313L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JAP...110a4313L"><span id="translatedtitle">Ripple dislocation <span class="hlt">slip</span> in wrinkled gold film deposited on polydimethylsiloxane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, C. B.; Chuang, Y. F.; Liu, Y. H.; Lee, Sanboh; Chou, Y. T.</p> <p>2011-07-01</p> <p>The motion of ripple dislocations in a wrinkled thin film of gold deposited on polydimethylsiloxane (PDMS) was investigated. The deposition was made under tensile load along the first direction on the PDMS plate. After the tensile load was released, a ripple pattern and ripple dislocations were formed on the surface. Upon reloading in the second direction, these ripple dislocations were able to <span class="hlt">slip</span>. At a given tensile load, the speed of <span class="hlt">slip</span> decreased as the loading time increased, and finally reached a constant value, which was increasing with the applied load. The measured data were interpreted with a dynamic model based on Newton's law of motion. Interaction of ripple dislocations was also observed. It was shown that a pair of positive and negative ripple dislocations of equal strength could annihilate each other or form a dipole, depending on the magnitude of the applied load.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22337633','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22337633"><span id="translatedtitle">Cytoplasmic streaming in plant cells: the role of wall <span class="hlt">slip</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wolff, K; Marenduzzo, D; Cates, M E</p> <p>2012-06-01</p> <p>We present a computer simulation study, via lattice Boltzmann simulations, of a microscopic model for cytoplasmic streaming in algal cells such as those of Chara corallina. We modelled myosin motors tracking along actin lanes as spheres undergoing directed motion along fixed lines. The sphere dimension takes into account the fact that motors drag vesicles or other organelles, and, unlike previous work, we model the boundary close to which the motors move as walls with a finite <span class="hlt">slip</span> layer. By using realistic parameter values for actin lane and myosin density, as well as for endoplasmic and vacuole viscosity and the <span class="hlt">slip</span> layer close to the wall, we find that this simplified view, which does not rely on any coupling between motors, cytoplasm and vacuole other than that provided by viscous Stokes flow, is enough to account for the observed magnitude of streaming velocities in intracellular fluid in living plant cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PApGe.139..627W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PApGe.139..627W"><span id="translatedtitle">Case history of a <span class="hlt">slip</span>-type rockburst</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, T. J.; Wideman, C. J.; Scott, D. F.</p> <p>1992-09-01</p> <p>First-motion analyses of digital seismic records and an assessment of damage provided conclusive evidence that a fault-<span class="hlt">slip</span> source mechanism was responsible for a Richter magnitude 2 that occurred at the Lucky Friday Mine on April 13, 1990. This event was the first time that movement along an argillite bed had been observed after the macroseismic monitoring system had been installed. The physical evidence of a shear-<span class="hlt">slip</span> type failure established confidence in using double-couple, first-motion analyses for the macroseismic system. The U.S. Bureau of Mines is conducting this research as part of its mission to enhance safety by reducing rockburst hazards in mines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/3852805','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/3852805"><span id="translatedtitle">Strategies for <span class="hlt">joint</span> appointments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Royle, J; Crooks, D L</p> <p>1985-01-01</p> <p>The structure and policies governing <span class="hlt">joint</span> appointments discussed above, are developed primarily through cooperation and collaboration between nursing service and education institutions. The <span class="hlt">joint</span> appointee participates in the process of negotiation of salary, benefits and role responsibilities and exploration of the implications of the appointment for personal career development. Implementation and maintenance of the appointment requires the collaborative efforts of the <span class="hlt">joint</span> appointee with both contracting agencies. Factors influencing the functioning of <span class="hlt">joint</span> appointees have been identified and strategies to facilitate functioning presented. The <span class="hlt">joint</span> appointee must be independent in thought and action yet adaptable to work within the boundaries of two social systems with differing values and expectations. Nursing management, peers and students can provide the support needed to overcome the frustrations and to achieve the rewards inherent in successful implementation of an exciting and innovative role. PMID:3852805</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27562127','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27562127"><span id="translatedtitle">[Approach to <span class="hlt">joint</span> effusion].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Henniger, M; Rehart, S</p> <p>2016-09-01</p> <p>The fundamental components of the differential diagnostics of <span class="hlt">joint</span> effusions are the patient history and clinical examination. In the case of unclear findings, arthrosonography can provide information for the distinction between intra-articular and extra-articular pathologies. In atraumatic <span class="hlt">joint</span> effusions inflammatory parameters in blood are determined in order to differentiate between systemic inflammatory and local inflammatory <span class="hlt">joint</span> effusions. In the case of normal values further diagnostics are carried out using imaging. With elevated inflammatory parameters the main differential diagnoses are gouty arthritis, autoimmune <span class="hlt">joint</span> processes and septic arthritis. When in doubt, a <span class="hlt">joint</span> aspiration and synovial fluid analysis should be performed to rule out septic arthritis or if necessary confirmation of gouty arthritis. PMID:27562127</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22755596','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22755596"><span id="translatedtitle">Interfacial <span class="hlt">slip</span> friction at a fluid-solid cylindrical boundary.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kannam, Sridhar Kumar; Todd, B D; Hansen, J S; Daivis, Peter J</p> <p>2012-06-28</p> <p>Recently we proposed a method to calculate the interfacial friction coefficient between fluid and solid at a planar interface. In this work we extend the method to cylindrical systems where the friction coefficient is curvature dependent. We apply the method to methane flow in carbon nanotubes, and find good agreement with non-equilibrium molecular dynamics simulations. The proposed method is robust, general, and can be used to predict the <span class="hlt">slip</span> for cylindrical nanofluidic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EGUGA..14.6911C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012EGUGA..14.6911C&link_type=ABSTRACT"><span id="translatedtitle">Creep versus Earthquake <span class="hlt">Slip</span>: New insights from rock magnetic data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chou, Y.-M.; Aubourg, C.; Song, S.-R.; Lee, T.-Q.; Song, Y.-F.</p> <p>2012-04-01</p> <p>Pseudotachylyte is generally believed as the best evidence of high-friction heating during earthquake. However, in clay-rich derived gouge, the temperature elevation is limited to large-scale endothermic dehydration reaction (Brantut et al., 2011). In such a context where melting is likely, it has been suggested that the characterization of neoformed mineral may be a diagnostic clue to distinguish between creep process and earthquake <span class="hlt">slip</span> zone. Here we show evidence of neoformed magnetic mineral in the active Chelungpu fault gouge that hosts the Chi-Chi <span class="hlt">slip</span> zone (Taiwan, Mw 7.6, 1999). Thanks to boreholes of Taiwan Chelungpu-fault Drilling Program and the recovery of fresh gouge, we get new evidence of neoformed magnetic minerals. Both rock magnetic investigation and transmission X-ray microscope image show the occurrence of neoformed 5 µm goethite (α-FeOOH) within the Chi-Chi 16 cm thick gouge. Goethite forms post-seismically from the cooling of >350°C fluids. In addition to goethite, we detect occurrence of neoformed pyrrhotite (Fe7S8). The pyrrhotite forms at the expense of pyrite, in response to elevation of temperature >500°C. Within the mm-thick Chi-Chi principal <span class="hlt">slip</span> zone, we do not detect evidence of goethite, nor pyrrhotite. Instead, we detect magnetite (Fe3O4). We suggest that a part of magnetite formed during friction-induced temperature elevation. We propose a simple model of evolution between goethite and magnetite within the entire gouge. If confirmed elsewhere, the recognition of the assemblage of iron oxide (magnetite), iron hydroxide (goethite) and iron sulfide (pyrrhotite) is possibly a diagnostic evidence of earthquake <span class="hlt">slip</span> rather than creep process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4714842','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4714842"><span id="translatedtitle"><span class="hlt">Slip</span> Potential for Commonly Used Inclined Grated Metal Walkways</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pollard, Jonisha P.; Heberger, John R.; Dempsey, Patrick G.</p> <p>2016-01-01</p> <p>Background No specific guidelines or regulations are provided by the Mine Safety and Health Administration for the use of inclined grated metal walkways in mining plants. Mining and other companies may be using walkway materials that do not provide sufficient friction, contributing to <span class="hlt">slip</span> and fall injuries. Purpose The purpose of this study was to determine if there are significant differences in the required friction for different grated metal walkways during walking in diverse conditions. Methods The normalized coefficients of friction were measured for 12 participants while walking up and down an instrumented walkway with different inclinations (0°, 5°, 10°, 15°, and 20°) and with and without the presence of a contaminant (glycerol). Self-reported <span class="hlt">slip</span> events were recorded and the required coefficients of friction were calculated considering only the anterior/posterior components of the shear forces. Additionally, the available coefficients of friction for these walkway materials were measured at the 0° orientation using a tribometer, with and without the presence of the contaminant, using a boot heel as well as Neolite as the test feet. Results The number of <span class="hlt">slips</span> increased when the inclination angle reached 10° and above. Of all materials tested, the diamond weave grating was found to have the best performance at all inclines and when contaminated or dry. A high number of <span class="hlt">slips</span> occurred for the perforated grating and serrated bar grating at 20° when contaminated. Conclusions Results of this study suggest that the diamond weave grating provides significantly better friction compared to serrated bar and perforated gratings, especially at inclines greater than 10°. PMID:26779388</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T33B2242R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T33B2242R"><span id="translatedtitle">Implications of Fault Curvature for <span class="hlt">Slip</span> Distributions, Opening, and Damage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ritz, E.; Pollard, D. D.; Griffith, W. A.</p> <p>2010-12-01</p> <p>In his seminal 1905 paper on the dynamics of faulting, E.M. Anderson idealized faults as planar structures. Although the theory of fault mechanics has developed from this idealization, abundant evidence from geological and geophysical investigations shows that fault surfaces exhibit geometric irregularities on many scales. Understanding the mechanical behavior of non-planar fault surfaces is a fundamental problem for scientists working on the brittle deformation of Earth’s crust and is of practical importance to disciplines such as rock mechanics, geotechnical engineering, and earthquake science. Geologic observations of exhumed meter-scale strike-<span class="hlt">slip</span> faults in the Bear Creek drainage, Sierra Nevada, CA, provide insights into the relationship between non-planar fault geometry and frictional <span class="hlt">slip</span> at depth. These faults have smoothly curving surface expressions which may be approximated as sinusoidal curves. We numerically investigate both the natural fault geometries and model sinusoidal faults. Earlier models for the stress and deformation near a sinusoidal fault assume boundary conditions and fault characteristics that are not observed in nature. The 2D displacement discontinuity boundary element method is combined with a complementarity algorithm to model quasi-static <span class="hlt">slip</span> on non-planar faults, and the resulting deformation of the nearby rock. This numerical technique can provide an accurate solution for any boundary value problem regarding crack-like features in an otherwise homogeneous and isotropic elastic material. Both field and numerical investigations indicate that non-planar fault geometry perturbs the along-fault <span class="hlt">slip</span> form the distribution predicted for planar faults. In addition, both field observations and numerical modeling show that sliding along curved faults at depth may lead to localized fault opening, affecting local permeability and fluid migration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4498895','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4498895"><span id="translatedtitle">Stokes’ Second Problem for a Micropolar Fluid with <span class="hlt">Slip</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Florea, Olivia Ana; Roşca, Ileana Constanţa</p> <p>2015-01-01</p> <p>In this paper is presented the model of an incompressible micropolar fluid flow with <span class="hlt">slip</span> using the initial and boundary conditions when the wall velocity is considered depending on the frequency of the vibration. Regarding the boundary conditions of the velocity at the wall, we remark that there is a discontinuity of the velocity at the fluid-wall interface. The solutions for velocity and microrotation with the given conditions are obtained using the method of numerical inversion of Laplace transform. PMID:26161780</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867866','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867866"><span id="translatedtitle">Composite <span class="hlt">slip</span> table of dissimilar materials for damping longitudinal modes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gregory, Danny L.; Priddy, Tommy G.; Smallwood, David O.; Woodall, Tommy D.</p> <p>1991-01-01</p> <p>A vibration <span class="hlt">slip</span> table for use in a vibration testing apparatus. The table s comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.S53A4476M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.S53A4476M"><span id="translatedtitle">Inversion for <span class="hlt">slip</span> distribution for the 2012 Costa Rica earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCormack, K. A.; Hesse, M. A.; Stadler, G.</p> <p>2014-12-01</p> <p>On 5 September 2012, a major megathrust earthquake (Mw=7.6) ruptured the plate interface beneath the Nicoya Peninsula, Costa Rica. This event was centered 12 km offshore of the central Nicoya coast, at a depth of 18 km. The maximum <span class="hlt">slip</span> exceeded 2 meters, and the rupture spread outward along the plate interface to encompass 3000 km2 of the Nicoya seismogenic zone. More than 1700 aftershocks were recorded within the first 5 days. These aftershocks outlined two distinct rupture patches; one centered on the central coast and the other beneath the southern tip of the peninsula. We formulate a Bayesian inverse problem to infer the coseismic <span class="hlt">slip</span> on the fault plane based on instantaneous surface displacements and changes in well heads in order to image the remaining "locked" patch that has been inferred previously. We compute the maximum a posteriori (MAP) estimate of the posterior <span class="hlt">slip</span> distribution on the fault, and use a local Gaussian approximation around the MAP point to characterize the uncertainty. The elastic deformation is computed using a finite element method that allows for the spatial variation of elastic properties that has been observed in the crust overlying the seismogenic zone. We solve the optimization problem using gradients obtained from adjoints. The linearity of the inverse problem allows for the efficient solution of the optimal experimental design problem for the placement of the GPS stations to monitor the remaining locked patch. In the future, the results obtained here will provide the initial condition for a time-dependent poroelastic model for fault <span class="hlt">slip</span> and fluid migration due to overpressure caused by a megathrust earthquake. This will provide constraints on the crustal permeability structure in a tectonically active region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.3254R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.3254R"><span id="translatedtitle">An aseismic <span class="hlt">slip</span> transient on the North Anatolian Fault</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rousset, Baptiste; Jolivet, Romain; Simons, Mark; Lasserre, Cécile; Riel, Bryan; Milillo, Pietro; ćakir, Ziyadin; Renard, François</p> <p>2016-04-01</p> <p>Constellations of Synthetic Aperture Radar (SAR) satellites with short repeat time acquisitions allow exploration of active faults behavior with unprecedented temporal resolution. Along the North Anatolian Fault (NAF) in Turkey, an 80 km long section has been creeping at least since the 1944, Mw 7.3 earthquake near Ismetpasa, with a current Interferometric Synthetic Aperture Radar (InSAR)-derived average creep rate of 8 ± 3 mm/yr (i.e., a third of the NAF long-term <span class="hlt">slip</span> rate). We use a dense set of SAR images acquired by the COSMO-SkyMed constellation to quantify the spatial distribution and temporal evolution of creep over 1 year. We identify a major burst of aseismic <span class="hlt">slip</span> spanning 31 days with a maximum <span class="hlt">slip</span> of 2 cm, between the surface and 4 km depth. This result shows that fault creep along this section of the NAF does not occur at a steady rate as previously thought, highlighting a need to revise our understanding of the underlying fault mechanics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1251174','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1251174"><span id="translatedtitle"><span class="hlt">Slip</span>-stacking Dynamics and the 20 Hz Booster</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Eldred, Jeffery; Zwaska, Robert</p> <p>2015-03-01</p> <p><span class="hlt">Slip</span>-stacking is an accumulation technique used at Fermilab since 2004 which nearly doubles the proton intensity. The Proton Improvement Plan II intensity upgrades require a reduction in <span class="hlt">slip</span>-stacking losses by approximately a factor of 2. We study the single-particle dynamics that determine the stability of <span class="hlt">slip</span>-stacking particles. We introduce universal area factors to calculate the available phase space area for any set of beam parameters without individual simulation. We show the particle loss as a function of time. We calculate the injection efficiency as a function of longitudinal emittance and aspect-ratio. We demonstrate that the losses from RF single particle dynamics can be reduced by a factor of 4-10 (depending on beam parameters) by upgrading the Fermilab Booster from a 15-Hz cycle-rate to a 20-Hz cycle-rate. We recommend a change in injection scheme to eliminate the need for a greater momentum aperture in the Fermilab Recycler.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6986264','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6986264"><span id="translatedtitle">Spiralling tapered <span class="hlt">slip</span>-on drill string stabilizer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Beasley, T.R.; Teng, C.C.</p> <p>1986-12-23</p> <p>A stabilizer is described for use in a drilling string comprising: a substantially cylindrical body member having a central passageway to accommodate the drill sting, the inside surface of the body member defining a right-hand spiralling thread with a tapered trailing edge which spirals from a starting point on the body member. The thread terminates internally of the body member in an arcuate recess extending around the interior of the body member; a key member is secured to the inner wall surface of the recess of the body member, the key member having a lug extending longitudinally of the body member within the recess; a <span class="hlt">slip</span> member adapted to thread within the body member between the body member and the drill string. The <span class="hlt">slip</span> defines a right-hand thread with a matching tapered trailing edge configured to make up with the right-hand thread on the body member and to wedge between the body member and the drill string. One end of the <span class="hlt">slip</span> terminates in a longitudinally disposed shoulder capable of abutting the lug upon threading of the clip within the body member.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5707559','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5707559"><span id="translatedtitle">Velocity dependence of serpentinite friction promotes aseismic <span class="hlt">slip</span> on faults</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reinen, L.A.; Weeks, J.D.; Tullis, T.E. . Dept. of Geological Sciences)</p> <p>1992-01-01</p> <p>Serpentinite is common on many crustal faults and it has been suggested that the presence of serpentine on these faults may promote aseismic <span class="hlt">slip</span>. Consequently, the authors have experimentally measured the frictional constitutive response of both antigorite and lizardite polymorphs of serpentine to step changes in velocity. This was done at room temperature in rotary direct shear; normal stress was 25 MPa, and velocities ranged from 32 mm/yr to 3.2 [times] 10[sup 5] mm/yr. The frictional behavior of both serpentine polymorphs indicates that the presence of either one on a fault would result in aseismic creep in the shallow crust at typical plate motion rates. In contrast to other rock types, such as granite, both serpentinites display velocity-strengthening behavior at slow sliding velocities: below some transitional velocity, the frictional resistance increases with velocity, thus promoting stable aseismic <span class="hlt">slip</span>. At faster velocities, however, frictional strength has a negative dependence on velocity (velocity weakening), which provides the potential for unstable sliding, leading to earthquakes. The coefficient of friction of the antigorite serpentinite is similar to that of other silicates, while that of the lizardite is much lower. The low frictional strength of lizardite may help explain some geologic observations that serpentine appears quite mobile during deformation in the crust. However, it is the velocity-strengthening behavior observed in both serpentinites at low sliding velocities, and not the frictional strength, that will promote aseismic <span class="hlt">slip</span> on serpentine-bearing faults at typical rates of plate motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.6861S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.6861S"><span id="translatedtitle">Pattern of dynamic displacements in a strike-<span class="hlt">slip</span> earthquake</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saltogianni, V.; Gianniou, M.; Moschas, F.; Stiros, S.</p> <p>2016-07-01</p> <p>High-rate (1 Hz) records from GPS stations uniformly distributed along the fault ruptures of the 2014 Samothraki-Gökçeada Mw6.9 earthquake in the North Aegean Trough, at the extension of the North Anatolian Fault Zone, were analyzed using the Precise Point Positioning (PPP) technique. Computed dynamic displacements shed light to the pattern of dynamic displacements during shallow strike-<span class="hlt">slip</span> earthquakes. The area of near-field static seismic displacements bounds ramp-type, long-period dynamic displacements (fling steps) in the sense of static displacements. Along-fault and normal to fault components of dynamic displacement follow typical attenuation laws, but attenuation is higher in the fault-parallel component hence confined to the area of static dislocations. Forward directivity and local, especially topography-controlled amplification effects, consistent with accelerometer evidence, were also observed. The overall pattern seems to characterize shallow strike-<span class="hlt">slip</span> earthquakes and is expected to prove useful to explain or even predict the near-field damaging potential of strike-<span class="hlt">slip</span> earthquakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JGR...10522617H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JGR...10522617H"><span id="translatedtitle">Distribution of strike-<span class="hlt">slip</span> faults on Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoppa, Gregory; Greenberg, Richard; Tufts, B. Randall; Geissler, Paul; Phillips, Cynthia; Milazzo, Moses</p> <p>2000-09-01</p> <p>Study of four different regions on Europa imaged by the Galileo spacecraft during its first 15 orbits has revealed 117 strike-<span class="hlt">slip</span> faults. Europa appears to form preferentially right-lateral faults in the southern hemisphere and left-lateral faults in the northern hemisphere. This observation is consistent with a model where diurnal tides due to orbital eccentricity drive strike-<span class="hlt">slip</span> motion through a process of ``walking,'' in which faults open and close out of phase with alternating right-and left-lateral shear. Lineaments that record both left-and right-lateral motion (e.g., Agave Linea) may record the accommodation of compression in nearby chaotic zones. Nearly all identified strike-<span class="hlt">slip</span> faults were associated with double ridges or bands, and few were detected along ridgeless cracks. Thus the depth of cracks without ridges does not appear to have penetrated to the low-viscosity decoupling layer, required for diurnal displacement, but cracks that have developed ridges do extend down to such a level. This result supports a model for ridge formation that requires cracks to penetrate to a decoupling layer, such as a liquid water ocean.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17606076','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17606076"><span id="translatedtitle">The dorsal approach to silicone implant arthroplasty of the proximal interphalangeal <span class="hlt">joint</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bickel, Kyle D</p> <p>2007-01-01</p> <p>Silicone implant arthroplasty (SIA) has been an effective alternative in the treatment of arthritic conditions of the proximal interphalangeal (PIP) <span class="hlt">joints</span> since its introduction into surgical practice in the early 1960s. Patients with post-traumatic, degenerative, and rheumatoid arthritis all may be candidates for PIP <span class="hlt">joint</span> SIA. The indications for SIA of the PIP <span class="hlt">joint</span> include pain, limited <span class="hlt">joint</span> mobility, and angular deformity of the <span class="hlt">joint</span> with underlying articular destruction. Contraindications include ankylosis of the <span class="hlt">joint</span> due to bony or soft-tissue restrictions, infection, inadequate soft-tissue support for coverage, absence of flexor and/or extensor tendon function, and considerable periarticular bone loss in the proximal and middle phalanges. Proximal interphalangeal <span class="hlt">joint</span> SIA can be accomplished by dorsal, volar, or midaxial approaches. The dorsal approach has the advantages of relative technical ease, excellent visibility of the articular surfaces for preparation of the implant canals, access to the extensor mechanism for correction of central <span class="hlt">slip</span> abnormalities, and preservation of the collateral ligaments. The surgical technique is outlined and includes handling of the extensor mechanism and central <span class="hlt">slip</span> attachment, mobilization of the collateral ligaments, <span class="hlt">joint</span> surface resection, preparation of the bony canals, implant sizing, implant insertion, and repair of the soft tissues. Pearls and pitfalls of the technique are outlined. Early postoperative mobilization with hand therapy is essential but must include protection of the repaired extensor apparatus. Complications include bony changes, implant failure, recurrent angular deviation or swan-neck deformity, particulate synovitis, and rarely, infection. Complications related to implant failure are most often managed with implant replacement or arthrodesis; those related to poor mobility, angular deformity and tendon imbalance, pain, or infection are managed by arthrodesis. Although SIA of the PIP <span class="hlt">joint</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..736M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..736M"><span id="translatedtitle">Long-term acceleration of aseismic <span class="hlt">slip</span> prior to the 2011 M9 Tohoku-oki earthquake: Constraints from repeating earthquakes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mavrommatis, Andreas; Segall, Paul; Uchida, Naoki; Johnson, Kaj</p> <p>2016-04-01</p> <p>A very long-duration deformation transient that spanned the period 1996-2011, prior to the M9 Tohoku-oki earthquake, was reported from continuous GPS observations in northern Honshu, Japan (Mavrommatis et al., 2014; Yokota and Koketsu, 2015). The transient was interpreted as accelerating aseismic <span class="hlt">slip</span> on the Japan Trench megathrust, i.e. a decadal-scale transient <span class="hlt">slip</span> event. Here we use independent observations of small repeating earthquakes that occurred on the megathrust to test for the GPS-inferred accelerating <span class="hlt">slip</span> and improve its spatial resolution. We test whether sequences of repeating earthquakes exhibit a statistically significant monotonic trend in recurrence interval by applying the nonparametric Mann-Kendall test. Offshore northern Tohoku, all sequences that pass the test exhibit decelerating recurrence, consistent with decaying afterslip following the 1994 M7.7 Sanriku earthquake. On the other hand, offshore south-central Tohoku, all sequences that pass the test exhibit accelerating recurrence, consistent with long-term accelerating creep prior to the 2011 ?9 earthquake. Using a physical model of repeating earthquake recurrence, we produce time histories of cumulative <span class="hlt">slip</span> on the plate interface. After correcting for afterslip following several M˜7 earthquakes in the period 2003-2011, we find that all but one sequence exhibit statistically significant <span class="hlt">slip</span> accelerations. Offshore south-central Tohoku, the estimated <span class="hlt">slip</span> acceleration is on average 2.9 mm/yr^2, consistent with the range of 2.6-4.0 mm/yr2 estimated from independent GPS data (Mavrommatis et al., 2014). From a <span class="hlt">joint</span> inversion of GPS and seismicity data, we infer that a substantial portion of the plate interface experienced accelerating creep in the 15 years prior to the M9 Tohoku-oki earthquake. The large <span class="hlt">slip</span> area of the Tohoku-oki earthquake appears to be partly bounded by accelerating creep, implying that most of the rupture area of the Tohoku-oki earthquake was either locked or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G53A1123C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G53A1123C"><span id="translatedtitle">Comparison of Geodetic and Late Pleistocene <span class="hlt">Slip</span> Rates for the Southern Dead Sea Fault System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cochran, W. J.; Gomez, F.; Abu Rajab, J. S.; Al-Tarazi, E.</p> <p>2012-12-01</p> <p>Comparisons of short-term (geodetic) and Late Quaternary <span class="hlt">slip</span> rates have been used to assess time-variable fault kinematics along various active faults, globally. Differences between such types <span class="hlt">slip</span> rates may have implications for crustal rheology and/or temporal variations in plate motion. This research aims to compare the geodetically-derived <span class="hlt">slip</span> rates with <span class="hlt">slip</span> rates based on Late Pleistocene landforms along the southern Dead Sea fault system (DSFS). The DSFS is an active, left-lateral transform that accommodates differential movement between the Arabian and Sinai plates. A number of <span class="hlt">slip</span> rates have been previously reported ranging from 2 to 6mm/yr. However, comparison of various <span class="hlt">slip</span> rates requires ensuring that associated uncertainties are assessed using a standard. New GPS velocities from Jordan are combined with other available GPS data, and are used to model <span class="hlt">slip</span> rates using elastic block models. Resulting <span class="hlt">slip</span> rates are 4.3 to 5.3 mm/yr with fault locking depths of 8 - 15 km. Late Pleistocene rates are assessed from published observations, as well as new data. New mapping of offset alluvial fans in the southern Wadi Araba was facilitated by multi-spectral imagery and high-resolution digital elevation model. These fans correlate with regional aggradation events, with the resulting Late Pleistocene <span class="hlt">slip</span> rates ranging from 4.2 to 5.1 mm/yr. Statistically, the geodetic and neotectonic <span class="hlt">slip</span> rates are identical. Additionally, a 3-dimensional <span class="hlt">slip</span> vector for the last earthquake in the northern Wadi Araba is constructed using close-range photogrammetry of a faulted Byzantine aqueduct that indicates both horizontal and vertical displacements. Previous studies suggested characteristic earthquake <span class="hlt">slip</span>, so <span class="hlt">slip</span> rates and this <span class="hlt">slip</span> vector provide a means of assessing mean EQ recurrence interval, as well as the role of earthquakes in constructing the long-term topography along this part of the transform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70028963','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70028963"><span id="translatedtitle">Surface <span class="hlt">slip</span> associated with the 2004 Parkfield, California, earthquake measured on alinement arrays</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lienkaemper, J.J.; Baker, B.; McFarland, F.S.</p> <p>2006-01-01</p> <p>Although still continuing, surface <span class="hlt">slip</span> from the 2004 Parkfield earth-quake as measured on alinement arrays appears to be approaching about 30-35 cm between Parkfield and Gold Hill. This includes <span class="hlt">slip</span> along the main trace and the Southwest Fracture Zone (SWFZ). <span class="hlt">Slip</span> here was higher in 1966 at about 40 cm. The distribution of 2004 <span class="hlt">slip</span> appears to have a shape similar to that of the 1966 event, but final <span class="hlt">slip</span> is expected to be lower in 2004 by about 3-15 cm, even when continuing <span class="hlt">slip</span> is accounted for. Proportionately, this difference is most notable at the south end at Highway 46, where the 1966 event <span class="hlt">slip</span> was 13 cm compared to the 2004 <span class="hlt">slip</span> of 4 cm. Continuous Global Positioning System and creepmeters suggest that significant surface coseismic <span class="hlt">slip</span> apparently occurred mainly on the SWFZ and perhaps on Middle Mountain (the latter possibly caused by shaking) (Langbein et al., 2005). Creepmeters indicate only minor (<0.2 cm) surface coseismic <span class="hlt">slip</span> occurred on the main trace between Parkfield and Gold Hill. We infer that 3-6 cm <span class="hlt">slip</span> accumulated across our arrays in the first 24 hr. At Highway 46, <span class="hlt">slip</span> appears complete, whereas the remaining sites are expected to take 2-6 years to reach their background creep rates. Following the 1966 event, afterslip at one site persisted as much as 5-10 years. The much longer recurrence intervals between the past two Parkfield earthquakes and the decreasing <span class="hlt">slip</span> per event may suggest that larger <span class="hlt">slip</span> deficits are now growing along the Parkfield segment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.198..727K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.198..727K"><span id="translatedtitle">Deterministic chaos in a simulated sequence of <span class="hlt">slip</span> events on a single isolated asperity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kato, Naoyuki</p> <p>2014-08-01</p> <p>Numerical simulation of repeated occurrences of <span class="hlt">slip</span> events on a fault patch (asperity) is used to interpret the mechanism of irregular sequences of <span class="hlt">slip</span> events. The fault is uniformly shear loaded at a constant rate, and the frictional stress acting on the fault is assumed to obey a rate- and state-dependent friction (RSF) law. A circular patch with velocity-weakening frictional property is embedded in the fault, which apart from this has velocity-strengthening frictional property. The numerical simulations are conducted using various characteristic <span class="hlt">slip</span> distances L of the RSF law. For small values of L seismic <span class="hlt">slip</span> events (earthquakes) repeatedly occur at regular intervals. With increasing L, the recurrence of <span class="hlt">slip</span> events becomes more complex. A period doubled <span class="hlt">slip</span> pattern, where seismic and aseismic <span class="hlt">slip</span> events alternately occur, multiperiodic patterns and aperiodic patterns occur. At the same time, <span class="hlt">slip</span> tends to become aseismic with increasing L. The distributions of shear stress on the fault just before <span class="hlt">slip</span> events are variable because of variation in the residual stress of the preceding <span class="hlt">slip</span> event and the shear stress generated by aseismic sliding during interseismic periods. These variations in shear stress cause the complex sequence of <span class="hlt">slip</span> events seen here. An iteration map of the recurrence intervals of <span class="hlt">slip</span> events for an aperiodic sequence of <span class="hlt">slip</span> events is expressed by a simple curve, indicating that the timing of an event is predictable from the previous time interval, and the sequence of <span class="hlt">slip</span> events exhibits deterministic chaos. To help interpret these results for a sequence of <span class="hlt">slip</span> events on a velocity-weakening patch embedded in a velocity-strengthening region, a numerical simulation is conducted of <span class="hlt">slip</span> on a velocity-weakening patch enclosed by a permanently locked region. In this case, no complex recurrence of <span class="hlt">slip</span> events is observed. When L is less than a critical value, seismic <span class="hlt">slip</span> events repeatedly occur at a constant interval. Stable sliding</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S31A2719L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S31A2719L"><span id="translatedtitle">Investigate the Spatiotemporal Relationship Between Slow <span class="hlt">Slip</span> Transients and Tremor in Cascadia Subduction Zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Z.; Fu, Y.; Bock, Y.; Jiang, Y.; Moore, A. W.; Owen, S. E.; Kedar, S.</p> <p>2015-12-01</p> <p>Episodic tremor and slow <span class="hlt">slip</span> events (SSE) have been observed in many subduction zones such as southwest Japan and Cascadia. Despite their relatively well-observed nature, the physical mechanism that underlies slow <span class="hlt">slip</span> and tremor remains unknown. Tremor has been thought either to be loaded directly by aseismic <span class="hlt">slip</span>, or to represent the different manifestations of the same physical process as slow <span class="hlt">slip</span>, or be modulated by the stressing and aseismic <span class="hlt">slip</span> rate. In Cascadia, slow <span class="hlt">slip</span> without tremor was observed only recently [Welch and Bartlow, 2014], suggesting a more complex relationship between episodic <span class="hlt">slip</span> and tremor. We use the combined daily position time series from a NASA MEaSUREs project and a time-dependent Kalman filter to examine the spatiotemporal relationship between slow <span class="hlt">slip</span> and tremor in Cascadia. The combined GPS position solutions are based on JPL and SIO independent solutions, using the GIPSY and GAMIT software, respectively, but with a consistent set of a priori epoch-date coordinates and metadata. We remove the outliers and common mode errors from the time series. We visually identify all transient <span class="hlt">slip</span> events and fit the time series with a model that consists of inter-SSE velocity, offsets, annual and semi-annual variation, and slow <span class="hlt">slip</span> transients. A grid-search is applied to estimate optimal duration and center time during the transient fit. The cleaned filtered time series with the inter-SSE velocity removed are then used in the <span class="hlt">slip</span> inversion. Our application to some recent SSEs shows a spectrum of different <span class="hlt">slip</span> and tremor behaviors. For example, despite good space-time correlation between high fault <span class="hlt">slip</span> rate and tremor locations, we see the instances where the tremors locate at the downdip <span class="hlt">slip</span> edge or <span class="hlt">slip</span> front, suggesting possible stressing from the <span class="hlt">slip</span> transient. We find that during the 2014 ETS event a period of high fault <span class="hlt">slip</span> rate and tremor is followed by a short period of tremorless <span class="hlt">slip</span>, indicating tremorless <span class="hlt">slip</span> in Cascadia</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eosweb.larc.nasa.gov/project/misr/joint_as_table','SCIGOV-ASDC'); return false;" href="https://eosweb.larc.nasa.gov/project/misr/joint_as_table"><span id="translatedtitle">MISR <span class="hlt">JOINT</span>_AS Data</span></a></p> <p><a target="_blank" href="http://eosweb.larc.nasa.gov/">Atmospheric Science Data Center </a></p> <p></p> <p>2014-07-21</p> <p><span class="hlt">Joint</span> Aerosol Product (<span class="hlt">JOINT</span>_AS) The MISR Level 3 Products are global or regional ... field campaigns at daily and monthly time scales. The <span class="hlt">Joint</span> Aerosol product provides a monthly global statistical summary of MISR ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940015904','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940015904"><span id="translatedtitle">Improved ceramic <span class="hlt">slip</span> casting technique. [application to aircraft model fabrication</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)</p> <p>1993-01-01</p> <p>A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, <span class="hlt">slip</span> casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous <span class="hlt">slip</span> casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the <span class="hlt">slip</span> material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920012484','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920012484"><span id="translatedtitle">Pressure vessel flex <span class="hlt">joint</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahn, Jon B. (Inventor)</p> <p>1992-01-01</p> <p>An airtight, flexible <span class="hlt">joint</span> is disclosed for the interfacing of two pressure vessels such as between the Space Station docking tunnel and the Space Shuttle Orbiter bulkhead adapter. The <span class="hlt">joint</span> provides for flexibility while still retaining a structural link between the two vessels required due to the loading created by the internal/external pressure differential. The <span class="hlt">joint</span> design provides for limiting the axial load carried across the <span class="hlt">joint</span> to a specific value, a function returned in the Orbiter/Station tunnel interface. The flex <span class="hlt">joint</span> comprises a floating structural segment which is permanently attached to one of the pressure vessels through the use of an inflatable seal. The geometric configuration of the <span class="hlt">joint</span> causes the tension between the vessels created by the internal gas pressure to compress the inflatable seal. The inflation pressure of the seal is kept at a value above the internal/external pressure differential of the vessels in order to maintain a controlled distance between the floating segment and pressure vessel. The inflatable seal consists of either a hollow torus-shaped flexible bladder or two rolling convoluted diaphragm seals which may be reinforced by a system of straps or fabric anchored to the hard structures. The <span class="hlt">joint</span> acts as a flexible link to allow both angular motion and lateral displacement while it still contains the internal pressure and holds the axial tension between the vessels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813167R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813167R"><span id="translatedtitle">Extreme multi-millennial <span class="hlt">slip</span> rate variations on the Garlock fault, California: geomorphology and geochronology of <span class="hlt">slip</span> rate constraints</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rhodes, Edward; Dolan, James; McGill, Sally; McAuliffe, Lee; Zinke, Robert</p> <p>2016-04-01</p> <p>Combining existing paleoseismology with new geomorphic constraints for the same part of the Central Garlock fault in California, USA, allows us to demonstrate pronounced variations in <span class="hlt">slip</span> rate during the Holocene for this left-lateral strike-<span class="hlt">slip</span> system. Our results have basic implications for understanding how faults store and release strain energy in large earthquakes, and for Probabilistic Seismic Hazard Assessment (PSHA). A series of well-preserved fluvial terraces within alluvial fans provide offset markers, and newly developed single grain K-feldspar IRSL dating allows us to constrain depositional ages and subsequent erosion of terrace risers with good precision, using multiple samples from several different locations. This new dating approach has wide applicability for paleoseismology and <span class="hlt">slip</span> rate studies, besides understanding environmental response to climatic events; agreement with independent age control provided by C-14 and Be-10 profiles comes from sites in the USA, Mexico, Tibet and Mongolia. Sediments dominated by a range of grain sizes from silt to boulders can be dated, and the technique is often applicable in locations where quartz OSL does not work well. We examine the interplay and coupling between climate and tectonics at millennial timescales, along with sedimentary and geomorphic responses, and consider how our understanding of fault dynamics can be improved with the benefit of these new approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900000237&hterms=worms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dworms','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900000237&hterms=worms&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dworms"><span id="translatedtitle">Compliant <span class="hlt">Joints</span> For Robots</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kerley, James J., Jr.</p> <p>1990-01-01</p> <p>Compliant <span class="hlt">joints</span> devised to accommodate misalignments of tools and/or workpieces with respect to robotic manipulators. Has characteristics and appearance of both universal-<span class="hlt">joint</span> and cable-spring-type flexible shaft coupling. Compliance derived from elastic properties of short pieces of cable. Compliance of <span class="hlt">joint</span> determined by lengths, distances between, relative orientations, thickness of strands, number of strands, material, amount of pretwist, and number of short pieces of cable. Worm-drive mechanism used to adjust lengths to vary compliance as needed during operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26868932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26868932"><span id="translatedtitle">Total ankle <span class="hlt">joint</span> replacement.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>2016-02-01</p> <p>Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed <span class="hlt">joint</span>, and over time the loss of mobility places stress on other <span class="hlt">joints</span> in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle <span class="hlt">joint</span> replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20552500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20552500"><span id="translatedtitle">Workers' experience of <span class="hlt">slipping</span> in U.S. limited-service restaurants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Verma, Santosh K; Chang, Wen-Ruey; Courtney, Theodore K; Lombardi, David A; Huang, Yueng-Hsiang; Brennan, Melanye J; Mittleman, Murray A; Perry, Melissa J</p> <p>2010-09-01</p> <p>The leading cause of injuries among restaurant workers is same-level falls, a significant proportion of which result from <span class="hlt">slipping</span>. This study examines the experience of limited-service restaurant workers with <span class="hlt">slipping</span>, their use of <span class="hlt">slip</span>-resistant shoes, and their floor-cleaning practices. A total of 475 workers from 36 limited-service restaurants in six U.S. states participated in a 12-week prospective cohort study on <span class="hlt">slipping</span> in the workplace. At baseline, participants completed a survey that gathered information about their demographics, perceptions of floor slipperiness, use of <span class="hlt">slip</span>-resistant shoes, floor cleaning practices, and number of <span class="hlt">slips</span> experienced in the previous 4 weeks. During the subsequent 12 weeks, participants reported their <span class="hlt">slip</span> experience weekly. Restaurant managers reported kitchen floor cleaning protocols and shoe policies. The overall rate of <span class="hlt">slipping</span> during the 12 weeks of the prospective study was 0.44 <span class="hlt">slips</span> per 40 work hours. The mean of the individual rate of <span class="hlt">slipping</span> varied among the restaurants from 0.02 to 2.49 <span class="hlt">slips</span> per 40 work hours, a rate ratio of more than 100 among the restaurants with the highest and the lowest rate of <span class="hlt">slipping</span>. Such a large variation, which is unlikely due to chance alone (p < 0.05), suggests that some restaurants are better able to control <span class="hlt">slipping</span> than others. The highest numbers of <span class="hlt">slips</span> were reported in the sink and fryer areas, which were also identified by restaurant workers as being the most slippery. Liquid and grease were reported as floor contaminants in over 70% of the <span class="hlt">slips</span>. In restaurants where <span class="hlt">slip</span>-resistant shoes were provided by the employer, 91% of participants wore them; whereas if they were neither provided nor encouraged, only 53.5% wore them (p < 0.01). Use of enzyme-based floor cleaners was widespread (25/36). In these restaurants, however, 62% of the participants who were responsible for cleaning floors reported using hot/warm water, thus violating the manufacturer's cold water floor</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015Tectp.638...43Z&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2015Tectp.638...43Z&link_type=ABSTRACT"><span id="translatedtitle">Fault <span class="hlt">slip</span> and earthquake recurrence along strike-<span class="hlt">slip</span> faults - Contributions of high-resolution geomorphic data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zielke, Olaf; Klinger, Yann; Arrowsmith, J. Ramon</p> <p>2015-01-01</p> <p>Understanding earthquake (EQ) recurrence relies on information about the timing and size of past EQ ruptures along a given fault. Knowledge of a fault's rupture history provides valuable information on its potential future behavior, enabling seismic hazard estimates and loss mitigation. Stratigraphic and geomorphic evidence of faulting is used to constrain the recurrence of surface rupturing EQs. Analysis of the latter data sets culminated during the mid-1980s in the formulation of now classical EQ recurrence models, now routinely used to assess seismic hazard. Within the last decade, Light Detection and Ranging (lidar) surveying technology and other high-resolution data sets became increasingly available to tectono-geomorphic studies, promising to contribute to better-informed models of EQ recurrence and <span class="hlt">slip</span>-accumulation patterns. After reviewing motivation and background, we outline requirements to successfully reconstruct a fault's offset accumulation pattern from geomorphic evidence. We address sources of uncertainty affecting offset measurement and advocate approaches to minimize them. A number of recent studies focus on single-EQ <span class="hlt">slip</span> distributions and along-fault <span class="hlt">slip</span> accumulation patterns. We put them in context with paleoseismic studies along the respective faults by comparing coefficients of variation CV for EQ inter-event time and <span class="hlt">slip</span>-per-event and find that a) single-event offsets vary over a wide range of length-scales and the sources for offset variability differ with length-scale, b) at fault-segment length-scales, single-event offsets are essentially constant, c) along-fault offset accumulation as resolved in the geomorphic record is dominated by essentially same-size, large offset increments, and d) there is generally no one-to-one correlation between the offset accumulation pattern constrained in the geomorphic record and EQ occurrence as identified in the stratigraphic record, revealing the higher resolution and preservation potential of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/002974.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/002974.htm"><span id="translatedtitle">Knee <span class="hlt">joint</span> replacement</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... is used to attach this part. Repair your muscles and tendons around the new <span class="hlt">joint</span> and close the surgical cut. The surgery takes about 2 hours. Most artificial knees have both metal and plastic parts. Some ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780009733','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780009733"><span id="translatedtitle">Wrist <span class="hlt">joint</span> assembly</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kersten, L.; Johnson, J. D. (Inventor)</p> <p>1978-01-01</p> <p>A wrist <span class="hlt">joint</span> assembly is provided for use with a mechanical manipulator arm for finely positioning an end-effector carried by the wrist <span class="hlt">joint</span> on the terminal end of the manipulator arm. The wrist <span class="hlt">joint</span> assembly is pivotable about a first axis to produce a yaw motion, a second axis is to produce a pitch motion, and a third axis to produce a roll motion. The wrist <span class="hlt">joint</span> assembly includes a disk segment affixed to the terminal end of the manipulator arm and a first housing member, a second housing member, and a third housing member. The third housing member and the mechanical end-effector are moved in the yaw, pitch, and roll motion. Drive means are provided for rotating each of the housings about their respective axis which includes a cluster of miniature motors having spur gears carried on the output drive shaft which mesh with a center drive gear affixed on the housing to be rotated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19710000482','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19710000482"><span id="translatedtitle">Improved orthopedic arm <span class="hlt">joint</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dane, D. H.</p> <p>1971-01-01</p> <p><span class="hlt">Joint</span> permits smooth and easy movement of disabled arm and is smaller, lighter and less expensive than previous models. Device is interchangeable and may be used on either arm at the shoulder or at the elbow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/003743.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/003743.htm"><span id="translatedtitle"><span class="hlt">Joint</span> fluid Gram stain</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Gram stain of <span class="hlt">joint</span> fluid ... result means no bacteria are present on the Gram stain. Normal value ranges may vary slightly among ... Abnormal results mean bacteria were seen on the Gram stain. This may be a sign of a ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007APS..MAR.B7002M&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007APS..MAR.B7002M&link_type=ABSTRACT"><span id="translatedtitle">Scaling in Columnar <span class="hlt">Joints</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morris, Stephen</p> <p>2007-03-01</p> <p>Columnar <span class="hlt">jointing</span> is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar <span class="hlt">jointing</span> in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rates, we suggest an advective-diffusive system is responsible for the rough scaling behavior of columnar <span class="hlt">joints</span>. This theory explains the order of magnitude difference in scales between <span class="hlt">jointing</span> in lavas and in starches. We investigated the scaling of average columnar cross-sectional areas in experiments where the evaporation rate was fixed using feedback methods. Our results suggest that the column area at a particular depth is related to both the current conditions, and hysteretically to the geometry of the pattern at previous depths. We argue that there exists a range of stable column scales allowed for any particular evaporation rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/007633.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/007633.htm"><span id="translatedtitle">Hip <span class="hlt">joint</span> injection</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... injected so the provider can see where to place the medicine. The steroid medicine is slowly injected into the <span class="hlt">joint</span>. After the injection, you will remain on the table for another 5 to 10 minutes or so. ...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.knowyourteeth.com/infobites/abc/article/?abc=t&iid=334&aid=1351','NIH-MEDLINEPLUS'); return false;" href="http://www.knowyourteeth.com/infobites/abc/article/?abc=t&iid=334&aid=1351"><span id="translatedtitle">Temporomandibular <span class="hlt">Joint</span> Disorder</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... 2008 Previous Next Related Articles: Temporomandibular <span class="hlt">Joint</span> Disorder (TMD) Are You Biting Off More Than You Can Chew? Equilibration May Lessen TMD Pain Fender-benders: Source of TMD? First Comes ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSV...382..140L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSV...382..140L"><span id="translatedtitle">Modeling stick-<span class="hlt">slip</span>-separation dynamics in a bimodal standing wave ultrasonic motor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Xiang; Yao, Zhiyuan; Lv, Qibao; Liu, Zhen</p> <p>2016-11-01</p> <p>Ultrasonic motor (USM) is an electromechanical coupling system with ultrasonic vibration, which is driven by the frictional contact force between the stator (vibrating body) and the rotor/slider (driven body). Stick-<span class="hlt">slip</span> motion can occur at the contact interface when USM is operating, which may affect the performance of the motor. This paper develops a physically-based model to investigate the complex stick-<span class="hlt">slip</span>-separation dynamics in a bimodal standing wave ultrasonic motor. The model includes both friction nonlinearity and intermittent separation nonlinearity of the system. Utilizing Hamilton's principle and assumed mode method, the dynamic equations of the stator are deduced. Based on the dynamics of the stator and the slider, sticking force during the stick phase is derived, which is used to examine the stick-to-<span class="hlt">slip</span> transition. Furthermore, the stick-<span class="hlt">slip</span>-separation kinematics is analyzed by establishing analytical criteria that predict the transition between stick, <span class="hlt">slip</span> and separation of the interface. Stick-<span class="hlt">slip</span>-separation motion is observed in the resulting model, and numerical simulations are performed to study the influence of parameters on the range of possible motions. Results show that stick-<span class="hlt">slip</span> motion can occur with greater preload and smaller voltage amplitude. Furthermore, a dimensionless parameter is proposed to predict the occurrence of stick-<span class="hlt">slip</span> versus <span class="hlt">slip</span>-separation motions, and its role in designing ultrasonic motors is discussed. It is shown that <span class="hlt">slip</span>-separation motion is favorable for the slider velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T13A2354O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T13A2354O"><span id="translatedtitle">Experimental investigation on the effects of normal stress on fracture propagation and <span class="hlt">slip</span> instability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ougier-Simonin, A.; Zhu, W.</p> <p>2011-12-01</p> <p>Recent discoveries of slow <span class="hlt">slip</span> phenomena, from low frequency earthquakes to episodic tremor and <span class="hlt">slip</span> events, create new challenges to our understanding of source processes. High pore pressure is often cited as the likely cause for these slow <span class="hlt">slip</span> events. The working hypothesis is that pore pressure excess reduces effective normal stress on the fault plane thus generates <span class="hlt">slip</span> instability. However, experimental evidence on whether and how different <span class="hlt">slip</span> instabilities results from high pore pressure is still missing. In this study, we conducted triaxial deformation experiments to investigate how the reduction of effective normal stress affects <span class="hlt">slip</span> instability and fracture propagation. Porous sedimentary rocks were deformed at constant strain rates and under fully drained conditions. We designed loading configurations so that brittle failure and frictional instability in samples deformed under decreasing effective stress can be compared to those under increasing effective stress. Our experimental results indicate that, 1) effects of loading configuration and strain rate on the brittle strength is negligible; 2) the <span class="hlt">slip</span> distance during fracture nucleation is sensitive to strain rate and loading path; 3) shear fracture energy released during fracture propagation is a function of <span class="hlt">slip</span>. However, fracture propagation in samples deformed under decreasing effective normal stress tend to be more stable, which bears similar characteristics with slow <span class="hlt">slip</span> events. The observed <span class="hlt">slip</span> instability under decreasing normal stress can be modeled using a theoretical framework proposed by Dieterich and Linker [1992]. Quantitative microstructural analysis was performed on samples undergone different stages of failure to characterize the progressive damage during fracture propagation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9061E..28H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9061E..28H"><span id="translatedtitle">Development of microsized <span class="hlt">slip</span> sensors using dielectric elastomer for incipient slippage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hwang, Do-Yeon; Kim, Baek-chul; Cho, Han-Jeong; Li, Zhengyuan; Lee, Youngkwan; Nam, Jae-Do; Moon, Hyungpil; Choi, Hyouk Ryeol; Koo, J. C.</p> <p>2014-04-01</p> <p>A humanoid robot hand has received significant attention in various fields of study. In terms of dexterous robot hand, <span class="hlt">slip</span> detecting tactile sensor is essential to grasping objects safely. Moreover, <span class="hlt">slip</span> sensor is useful in robotics and prosthetics to improve precise control during manipulation tasks. In this paper, sensor based-human biomimetic structure is fabricated. We reported a resistance tactile sensor that enables to detect a <span class="hlt">slip</span> on the surface of sensor structure. The resistance <span class="hlt">slip</span> sensor that the novel developed uses acrylonitrile-butadiene rubber (NBR) as a dielectric substrate and carbon particle as an electrode material. The presented sensor device in this paper has fingerprint-like structures that are similar with the role of the human's finger print. It is possible to measure the <span class="hlt">slip</span> as the structure of sensor makes a deformation and it changes the resistance through forming a new conductive route. To verify effectiveness of the proposed <span class="hlt">slip</span> detection, experiment using prototype of resistance <span class="hlt">slip</span> sensor is conducted with an algorithm to detect <span class="hlt">slip</span> and <span class="hlt">slip</span> was successfully detected. In this paper, we will discuss the <span class="hlt">slip</span> detection properties so four sensor and detection principle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDE14002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDE14002H"><span id="translatedtitle">A priori models for predicting drag reduction for flow over heterogeneous <span class="hlt">slip</span> boundaries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heck, Margaret; Papavassiliou, Dimitrios</p> <p>2015-11-01</p> <p><span class="hlt">Slip</span> at fluid-fluid/fluid-solid interfaces is a subject of interest for many engineering applications, ranging from porous materials to biomedical devices to separation processes. Despite remarkable effort to include the effects of surface topology and various flow and physical properties in models describing fluid <span class="hlt">slip</span>, the mathematical description of flow over mixed <span class="hlt">slip</span> boundaries is still under investigation. Using similarity theory, which is based on the generalized homogeneity of physical laws governing most systems and takes advantage of similarity in the spatial distribution of characteristics of motion, the equivalent <span class="hlt">slip</span> velocity is shown to be a function of the geometry of a microfluidic system. The results are used to predict the <span class="hlt">slip</span> velocity for flow over surfaces with periodically repeating no-<span class="hlt">slip</span>/free-shear boundaries in the shape of rectangles for 16%-50% solid fractions. The equivalent <span class="hlt">slip</span> velocity for flow over rectangular boundaries can then be related to the those for flow over surfaces with square and circular no-<span class="hlt">slip</span> boundaries using characteristic length ratios. The models developed using this apporach can be directly used to estimate the <span class="hlt">slip</span> velocity for flow over various free-shear/no-<span class="hlt">slip</span> boundaries for Couette, laminar flow conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T23A2245L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T23A2245L"><span id="translatedtitle">Surface Melt Produced on Faults During Laboratory Stick-<span class="hlt">slip</span> Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lockner, D. A.; Moore, D. E.; Beeler, N. M.; Kilgore, B. D.</p> <p>2010-12-01</p> <p>Melt coated most of the fault surface on dry, bare, room-temperature granite faults as a result of stick-<span class="hlt">slip</span> in triaxial loading at 400 MPa confining pressure. Saw-cut surfaces, inclined 30 degrees to the sample axis, were prepared by lapping with 600 grit SiC. Dynamic weakening during stick-<span class="hlt">slip</span> caused total stress drops that ranged from 250-350 MPa shear stress (peak normal stress was 550-600 MPa) with fault-parallel <span class="hlt">slip</span> from 2.0 to 2.8 mm. The resulting melt layers are estimated to be 5-40 microns thick and for multiple stick-<span class="hlt">slip</span> events show evidence of re-worked glassy material. In contrast, repeated stick-<span class="hlt">slip</span> cycles at 50 MPa confining pressure and a cumulative 9 mm displacement produced fine-grained fault gouge but showed no evidence of surface melting. At 50 MPa, stress drops were typically 35 percent, peak shear and normal stresses were approximately 66 and 88 MPa, respectively, and fault-parallel <span class="hlt">slip</span> was about 0.14 mm. With recent interest in determining frictional properties of rock at coseismic <span class="hlt">slip</span> speeds, a variety of high-speed rotary testing machines have been developed that allow for large total <span class="hlt">slip</span>. Since maximum fault surface temperature depends, in part, on the product: (shear stress) x (<span class="hlt">slip</span> speed) x (<span class="hlt">slip</span> duration), these rotary machines can achieve high surface temperatures at modest normal stress. However, evidence for dynamic heating and surface weakening in laboratory stick-<span class="hlt">slip</span> experiments was reported more than 30 years ago using triaxial test machines, although the observations at that time were not conclusive. By operating at normal stresses 10 to 20 times greater that those used in unconfined rotary machines, triaxial stick-<span class="hlt">slip</span> experiments are able to develop high transient surface temperatures that include pseudotachylite formation, even with limited total <span class="hlt">slip</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.tmp..181G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.tmp..181G"><span id="translatedtitle">Slow <span class="hlt">Slip</span> History for the MEXICO Subduction Zone: 2005 Through 2011</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graham, Shannon; DeMets, Charles; Cabral-Cano, Enrique; Kostoglodov, Vladimir; Rousset, Baptiste; Walpersdorf, Andrea; Cotte, Nathalie; Lasserre, Cécile; McCaffrey, Robert; Salazar-Tlaczani, Luis</p> <p>2015-12-01</p> <p>To further our understanding of the seismically hazardous Mexico subduction zone, we estimate the first time-dependent <span class="hlt">slip</span> distributions and Coulomb failure stress changes for the six major slow <span class="hlt">slip</span> events (SSEs) that occurred below Mexico between late 2005 and mid-2011. <span class="hlt">Slip</span> dist ributions are the first to be estimated from all continuous GPS data in central and southern Mexico, which better resolves slow <span class="hlt">slip</span> in space and time than was previously possible in this region. Below Oaxaca, <span class="hlt">slip</span> during previously un-modeled SSEs in 2008/9 and 2010/11 extended farther to the west than previous SSEs. This constitutes the first evidence that slow <span class="hlt">slip</span> accounts for deep <span class="hlt">slip</span> within a previously noted gap between the Oaxaca and Guerrero SSE source regions. The <span class="hlt">slip</span> that we estimate for the two SSEs that originated below Guerrero between 2005 and 2011 agrees with <span class="hlt">slip</span> estimated in previous, mostly static-offset SSE modeling studies; however, we show that both SSEs migrated eastward toward the Oaxaca SSE source region. In accord with previous work, we find that slow <span class="hlt">slip</span> below Guerrero intrudes up-dip into the potentially seismogenic region, presumably accounting for some of the missing <span class="hlt">slip</span> within the well-described Guerrero seismic gap. In contrast, slow <span class="hlt">slip</span> below Oaxaca between 2005 and 2011 occurred mostly down-dip from the seismogenic regions defined by the rupture zones of large thrust earthquakes in 1968 and 1978 and released all of the <span class="hlt">slip</span> deficit that accumulated in the down-dip region during this period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T42A..06M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T42A..06M"><span id="translatedtitle">Disentangling Fault Scarp Geometry and <span class="hlt">Slip</span>-Distribution in 3D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mackenzie, D.; Walker, R. T.</p> <p>2015-12-01</p> <p>We present a new and inherently 3D approach to the analysis of fault scarp geometry using high resolution topography. Recent advance in topographic measurement techniques (LiDAR and Structure from Motion) has allowed the extensive measurement of single earthquake scarps and multiple event cumulative scarps to draw conclusions about along-strike <span class="hlt">slip</span> variation and characteristic <span class="hlt">slip</span>. Present analysis of the resulting point clouds and digital elevation models is generally achieved by taking vertical or map view profiles of geomorphic markers across the scarp. Profiles are done at numerous locations along strike carefully chosen to avoid regions degraded by erosion/deposition. The resulting <span class="hlt">slip</span> distributions are almost always extremely variable and "noisy", both for strike-<span class="hlt">slip</span> and dip-<span class="hlt">slip</span> faulting scarps and it is often unclear whether this reflects <span class="hlt">slip</span> variation, noise/erosion, site effects or geometric variation. When observing palaeo-earthquake and even modern event scarps, the full geometry, such as the degree of oblique <span class="hlt">slip</span> or the fault dip, is often poorly constrained. We first present the results of synthetic tests to demonstrate the introduction of significant apparent noise by simply varying terrain, fault and measurement geometry (slope angle, slope azimuth, fault dip and <span class="hlt">slip</span> obliquity). Considering fully 3-dimensional marker surfaces (e.g. Planar or conical) we use the variation in apparent offset with terrain and measurement geometry, to constrain the <span class="hlt">slip</span> geometry in 3D. Combining measurements windowed along strike, we show that determining the <span class="hlt">slip</span> vector is reduced to a simple linear problem. We conclude that for scarps in regions of significant topography or with oblique <span class="hlt">slip</span>, our method will give enhanced <span class="hlt">slip</span> resolution while standard methods will give poor <span class="hlt">slip</span> resolution. We test our method using a Structure from Motion pointcloud and digital elevation model covering a ~25 km stretch of a thrust fault scarp in the Kazakh Tien Shan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4008576','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4008576"><span id="translatedtitle">Temporal Changes in the Required Shoe-Floor Friction when Walking following an Induced <span class="hlt">Slip</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Beringer, Danielle N.; Nussbaum, Maury A.; Madigan, Michael L.</p> <p>2014-01-01</p> <p>Biomechanical aspects of <span class="hlt">slips</span> and falls have been widely studied to facilitate fall prevention strategies. Prior studies have shown changes in gait after an induced <span class="hlt">slipping</span> event. As such, most researchers only <span class="hlt">slip</span> participants one time to avoid such changes that would otherwise reduce the external validity of experimental results. The ability to <span class="hlt">slip</span> participants more than once, after allowing gait to return to a natural baseline, would improve the experimental efficiency of such studies. Therefore, the goal of this study was to characterize the temporal changes in required shoe-floor friction when walking following an induced <span class="hlt">slip</span>. Two experiments were completed, and each employed a different potential strategy to promote the return of gait to a natural baseline after <span class="hlt">slipping</span>. In the first experiment, extended time away from the laboratory was used to promote the return of gait to baseline. We measured required coefficient-of-friction among 36 young adult male participants over four sessions. The first three sessions provided measurements during baseline (i.e., natural gait) both prior to <span class="hlt">slipping</span> and immediately after <span class="hlt">slipping</span>. The fourth session provided a measurement 1–12 weeks after <span class="hlt">slipping</span>. In the second experiment, an extensive number of walking trials was used to promote the return of gait to baseline. We measured required coefficient-of-friction among 10 young adult male participants in a single session. Measurements were collected during 10 baseline walking trials, immediately after <span class="hlt">slipping</span>, and during 50–55 additional trials. In both experiments, required coefficient-of-friction decreased 12–16% immediately after a single <span class="hlt">slip</span>, increased toward baseline levels over subsequent weeks/walking trials, but remained statistically different from baseline at the end of the experiments. Based on these results, experiments involving <span class="hlt">slipping</span> participants multiple times may not have a high level of external validity, and researchers are encouraged to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173.3445G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173.3445G"><span id="translatedtitle">Slow <span class="hlt">Slip</span> History for the MEXICO Subduction Zone: 2005 Through 2011</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graham, Shannon; DeMets, Charles; Cabral-Cano, Enrique; Kostoglodov, Vladimir; Rousset, Baptiste; Walpersdorf, Andrea; Cotte, Nathalie; Lasserre, Cécile; McCaffrey, Robert; Salazar-Tlaczani, Luis</p> <p>2016-10-01</p> <p>To further our understanding of the seismically hazardous Mexico subduction zone, we estimate the first time-dependent <span class="hlt">slip</span> distributions and Coulomb failure stress changes for the six major slow <span class="hlt">slip</span> events (SSEs) that occurred below Mexico between late 2005 and mid-2011. <span class="hlt">Slip</span> dist ributions are the first to be estimated from all continuous GPS data in central and southern Mexico, which better resolves slow <span class="hlt">slip</span> in space and time than was previously possible in this region. Below Oaxaca, <span class="hlt">slip</span> during previously un-modeled SSEs in 2008/9 and 2010/11 extended farther to the west than previous SSEs. This constitutes the first evidence that slow <span class="hlt">slip</span> accounts for deep <span class="hlt">slip</span> within a previously noted gap between the Oaxaca and Guerrero SSE source regions. The <span class="hlt">slip</span> that we estimate for the two SSEs that originated below Guerrero between 2005 and 2011 agrees with <span class="hlt">slip</span> estimated in previous, mostly static-offset SSE modeling studies; however, we show that both SSEs migrated eastward toward the Oaxaca SSE source region. In accord with previous work, we find that slow <span class="hlt">slip</span> below Guerrero intrudes up-dip into the potentially seismogenic region, presumably accounting for some of the missing <span class="hlt">slip</span> within the well-described Guerrero seismic gap. In contrast, slow <span class="hlt">slip</span> below Oaxaca between 2005 and 2011 occurred mostly down-dip from the seismogenic regions defined by the rupture zones of large thrust earthquakes in 1968 and 1978 and released all of the <span class="hlt">slip</span> deficit that accumulated in the down-dip region during this period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24789299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24789299"><span id="translatedtitle">Temporal changes in the required shoe-floor friction when walking following an induced <span class="hlt">slip</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beringer, Danielle N; Nussbaum, Maury A; Madigan, Michael L</p> <p>2014-01-01</p> <p>Biomechanical aspects of <span class="hlt">slips</span> and falls have been widely studied to facilitate fall prevention strategies. Prior studies have shown changes in gait after an induced <span class="hlt">slipping</span> event. As such, most researchers only <span class="hlt">slip</span> participants one time to avoid such changes that would otherwise reduce the external validity of experimental results. The ability to <span class="hlt">slip</span> participants more than once, after allowing gait to return to a natural baseline, would improve the experimental efficiency of such studies. Therefore, the goal of this study was to characterize the temporal changes in required shoe-floor friction when walking following an induced <span class="hlt">slip</span>. Two experiments were completed, and each employed a different potential strategy to promote the return of gait to a natural baseline after <span class="hlt">slipping</span>. In the first experiment, extended time away from the laboratory was used to promote the return of gait to baseline. We measured required coefficient-of-friction among 36 young adult male participants over four sessions. The first three sessions provided measurements during baseline (i.e., natural gait) both prior to <span class="hlt">slipping</span> and immediately after <span class="hlt">slipping</span>. The fourth session provided a measurement 1-12 weeks after <span class="hlt">slipping</span>. In the second experiment, an extensive number of walking trials was used to promote the return of gait to baseline. We measured required coefficient-of-friction among 10 young adult male participants in a single session. Measurements were collected during 10 baseline walking trials, immediately after <span class="hlt">slipping</span>, and during 50-55 additional trials. In both experiments, required coefficient-of-friction decreased 12-16% immediately after a single <span class="hlt">slip</span>, increased toward baseline levels over subsequent weeks/walking trials, but remained statistically different from baseline at the end of the experiments. Based on these results, experiments involving <span class="hlt">slipping</span> participants multiple times may not have a high level of external validity, and researchers are encouraged to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.S31A2721K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.S31A2721K"><span id="translatedtitle">Assessing the Updip Spatial Offset of Tremor and <span class="hlt">Slip</span> during ETS Events in Cascadia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krogstad, R. D.; Schmidt, D. A.</p> <p>2015-12-01</p> <p>We investigate the updip spatial overlap of tremor and <span class="hlt">slip</span> during recent episodic tremor and <span class="hlt">slip</span> (ETS) events in Cascadia using a combination of forward and inverse models constrained by GPS, strainmeter, and tremor observations. Results from major ETS events in northern Cascadia suggest that, although there is significant spatial overlap, slow <span class="hlt">slip</span> tends to extend further updip than tremor. ETS activity is thought to be dependent on a range of parameters, such as variable fluid pressures, temperature dependent physical properties, and facies changes. A spatial offset would indicant that tremor and <span class="hlt">slip</span> are reflective of different physical conditions. While a clear offset of tremor and <span class="hlt">slip</span> has been observed in multiple other subduction zones, a similar offset in Cascadia has remained difficult to constrain. Here we seek to establish whether the updip spatial offset is real in Cascadia and to quantify its extent. To complement GPS observations in Cascadia, we incorporate high fidelity strainmeter observations into inversions and sensitivity tests of iterative forward models. Tremor distributions are used as a proxy for <span class="hlt">slip</span> and incorporated into <span class="hlt">slip</span> models where parameters affecting the distribution and magnitude of <span class="hlt">slip</span> are allowed to vary. These <span class="hlt">slip</span> models are used to forward predict surface displacements and strains, which are then compared to the geodetic observations and inferred <span class="hlt">slip</span> based on geodetic inversions. Results indicate that, while the tremor-derived <span class="hlt">slip</span> distributions do a good job predicting the broad-scale surface deformation, the best-fit models have <span class="hlt">slip</span> updip of the peak tremor activity. The fine-scale relationship of tremor and <span class="hlt">slip</span> appears to vary on an event-by-event basis, where areas of high tremor density do not always correlate with increased surface displacements and vice-versa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MSSP...76..665B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MSSP...76..665B"><span id="translatedtitle">Estimators of wheel <span class="hlt">slip</span> for electric vehicles using torque and encoder measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boisvert, M.; Micheau, P.</p> <p>2016-08-01</p> <p>For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the <span class="hlt">slip</span> ratio of the electric-powered wheel. A <span class="hlt">slip</span> tracking controller requires an accurate <span class="hlt">slip</span> estimation in the overall range of the <span class="hlt">slip</span> ratio (from 0 to 1), contrary to the conventional <span class="hlt">slip</span> limiter (ABS) which calls for an accurate <span class="hlt">slip</span> estimation in the critical <span class="hlt">slip</span> area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the <span class="hlt">slip</span> ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the <span class="hlt">slip</span> of a wheel, both wheel speed and vehicle speed must be known. Several studies provide algorithms that allow obtaining a good estimation of vehicle speed. On the other hand, there is no proposed algorithm for the conditioning of the wheel speed measurement. Indeed, the noise included in the wheel speed measurement reduces the accuracy of the <span class="hlt">slip</span> estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of <span class="hlt">slip</span> ratio were developed. The first calculates the <span class="hlt">slip</span> ratio with data provided by an observer of vehicle speed and of propeller wheel speed. The second observer uses an original nonlinear model of the <span class="hlt">slip</span> ratio as a function of the electric motor. A sinus tracking algorithm is included in the two observers, in order to reject harmonic disturbances of wheel speed measurement. Moreover, mass and road uncertainties can be compensated with a coefficient adapted online by an RLS. The algorithms were implemented and tested with a three-wheel recreational hybrid vehicle. Experimental results show the efficiency of both methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/in0219.sheet.00006a/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/in0219.sheet.00006a/"><span id="translatedtitle">Panel Post & Diagonal Brace <span class="hlt">Joint</span> Detail; Crossbracing Center <span class="hlt">Joint</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Panel Post & Diagonal Brace <span class="hlt">Joint</span> Detail; Crossbracing Center <span class="hlt">Joint</span> Detail; Chord, Panel Post, Tie Bar, & Diagonal Brace <span class="hlt">Joint</span> Detail; Chord, Tie Bar, & Crossbracing <span class="hlt">Joint</span> Detail - Medora Bridge, Spanning East Fork of White River at State Route 235, Medora, Jackson County, IN</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/143942','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/143942"><span id="translatedtitle">High pressure ceramic <span class="hlt">joint</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ward, M.E.; Harkins, B.D.</p> <p>1993-11-30</p> <p>Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present <span class="hlt">joint</span> when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present <span class="hlt">joint</span> used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present <span class="hlt">joint</span> is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The <span class="hlt">joint</span> and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present <span class="hlt">joint</span> mechanically provides a high strength load bearing <span class="hlt">joint</span> having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869036','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869036"><span id="translatedtitle">High pressure ceramic <span class="hlt">joint</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ward, Michael E.; Harkins, Bruce D.</p> <p>1993-01-01</p> <p>Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present <span class="hlt">joint</span> when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present <span class="hlt">joint</span> used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present <span class="hlt">joint</span> is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The <span class="hlt">joint</span> and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present <span class="hlt">joint</span> mechanically provides a high strength load bearing <span class="hlt">joint</span> having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T44B..07W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T44B..07W"><span id="translatedtitle">Interseismic, coseismic, postseismic, and slow <span class="hlt">slip</span> event deformation above a shallow subduction thrust in the western Solomon Islands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wallace, L. M.; Taylor, F. W.; Bevis, M. G.; Phillips, D. A.; Walter, J. I.; Kendrick, E. C.; Papabatu, A. K.</p> <p>2015-12-01</p> <p>The western Solomon Islands are a remarkable natural laboratory to investigate processes occurring on the shallowest (<10 km depth) portions of the subduction interface. Islands within the New Georgia Group are located <15 km from the San Cristobal Trench, with the subduction thrust located only a few km beneath the southwest coast of islands like Rannonga and Rendova. This offers a globally unique opportunity to use GPS and other land-based methods to monitor deformation processes very close to the trench at a subduction zone. We present results from a campaign GPS network in the western Solomons that has been operated from 1996-present. The data from 1996-2002 indicate interseismic coupling on the shallow portion of the interface, at a rate of nearly 100% of the relative plate motion. Coupling does not appear to extend deeper than ~20 km depth, and the relatively shallow down-dip limit of coupling is consistent with subduction of young (<6 Ma) oceanic crust of the Woodlark Basin. We also show evidence for a slow <span class="hlt">slip</span> event in late 2000, observed at a GPS site near Gizo that was running continuously from 1999-2002. In April 2007, an Mw 8.1 earthquake occurred on the subduction thrust beneath the network, resulting in large coseismic displacements at nearby campaign GPS sites. The earthquake caused widespread coastal uplift and subsidence in the region, as revealed by studies of coral microatolls following the earthquake (Taylor et al., 2008). We invert displacements of the GPS sites <span class="hlt">jointly</span> with vertical displacements of coral microatolls to evaluate the coseismic <span class="hlt">slip</span> during the earthquake. The area of the interface that underwent <span class="hlt">slip</span> in the earthquake matches well with the region that was interseismically coupled just prior to the 2007 earthquake. The data also require large coseismic <span class="hlt">slip</span> on the shallow interface near the trench, which likely contributed to the generation of a large, damaging tsunami following the earthquake. We also show results from a recent</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.S21C2066U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.S21C2066U"><span id="translatedtitle">Experimental Modeling of Dynamic Shallow Dip-<span class="hlt">Slip</span> Faulting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uenishi, K.</p> <p>2010-12-01</p> <p>In our earlier study (AGU 2005, SSJ 2005, JPGU 2006), using a finite difference technique, we have conducted some numerical simulations related to the source dynamics of shallow dip-<span class="hlt">slip</span> earthquakes, and suggested the possibility of the existence of corner waves, i.e., shear waves that carry concentrated kinematic energy and generate extremely strong particle motions on the hanging wall of a nonvertical fault. In the numerical models, a dip-<span class="hlt">slip</span> fault is located in a two-dimensional, monolithic linear elastic half space, and the fault plane dips either vertically or 45 degrees. We have investigated the seismic wave field radiated by crack-like rupture of this straight fault. If the fault rupture, initiated at depth, arrests just below or reaches the free surface, four Rayleigh-type pulses are generated: two propagating along the free surface into the opposite directions to the far field, the other two moving back along the ruptured fault surface (interface) downwards into depth. These downward interface pulses may largely control the stopping phase of the dynamic rupture, and in the case the fault plane is inclined, on the hanging wall the interface pulse and the outward-moving Rayleigh surface pulse interact with each other and the corner wave is induced. On the footwall, the ground motion is dominated simply by the weaker Rayleigh pulse propagating along the free surface because of much smaller interaction between this Rayleigh and the interface pulse. The generation of the downward interface pulses and corner wave may play a crucial role in understanding the effects of the geometrical asymmetry on the strong motion induced by shallow dip-<span class="hlt">slip</span> faulting, but it has not been well recognized so far, partly because those waves are not expected for a fault that is located and ruptures only at depth. However, the seismological recordings of the 1999 Chi-Chi, Taiwan, the 2004 Niigata-ken Chuetsu, Japan, earthquakes as well as a more recent one in Iwate-Miyagi Inland</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.H31A1262B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.H31A1262B"><span id="translatedtitle">River Captures and Erosional Disequilibrium Along Strike-<span class="hlt">slip</span> Faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brocard, G. Y.; Fayon, A. K.; Perg, L. A.; Paola, C.; Teyssier, C.; Whitney, D. L.; Mota, M.; Moran-Ical, S.</p> <p>2005-12-01</p> <p>River captures are internal instabilities of erosion systems and are inherently promoted by strike-<span class="hlt">slip</span> faulting. A capture event can generate a wave of incision that propagates from the capture site upstream and/or downstream, resulting in an increased bulk erosion rate around the capture site. Thus, under steady boundary conditions, drainage diversions trigger pulses of erosion, sediment production, rock exhumation and isostatic rebound. Therefore, a significant part of the erosion in oblique tectonics can be achieved in a state of significant departure from short-term dynamic equilibrium. The frequency, intensity, and duration of these events set the timescale over which their integrated effects can be regarded as the expression of a long-term dynamic equilibrium. We are investigating the effects of a large river capture on the oblique collision between the North American and Caribbean plates in Guatemala. Several thousands of kilometers of strike-<span class="hlt">slip</span> displacement have been accommodated along this boundary during the Tertiary. The deformation is now concentrated mostly along the E-W Motagua strike-<span class="hlt">slip</span> fault. Oblique tectonics is discernable within a 50 km wide topographic belt, north of this fault (Sierra de las Minas - Sierra de Chuacus range). On the northern flank of this range, deformation includes 130 km offset across the Polochic strike-<span class="hlt">slip</span> fault, documented by both geological structures and drainage patterns. Numerous elbows and dry valleys show the progressive transformation of the initial transverse (S-N) drainage crossing the fault into a transverse-parallel (E-W) system that developed during increasing displacement along the fault. The drainage reorganization operates by river lengthening, captures, and avulsions. One of the latest capture sites is surrounded by a large (110x30 km) zone of deeply (1500 m) dissected landscape that coincides with the captured catchment. This zone sharply contrasts with the surrounding areas where large fragments of a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.T53F..06J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.T53F..06J"><span id="translatedtitle">Seismic <span class="hlt">Slip</span> on an Oblique Detachment Fault at Low Angles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janecke, S. U.; Steely, A. N.; Evans, J. P.</p> <p>2008-12-01</p> <p>Pseudotachylytes are one of the few accepted indicators of seismic <span class="hlt">slip</span> along ancient faults. Low-angle normal faults have produced few large earthquakes in historic times and low-angle normal faults (detachment faults) are typically severely misoriented relative to a vertical maximum compressive stress. As a result many geoscientists question whether low-angle normal faults produce earthquakes at low angles. Relationships in southern California show that a major low-angle normal-oblique fault <span class="hlt">slipped</span> at low angles and produced large earthquakes. The exhumed Late Cenozoic West Salton detachment fault preserves spectacular fault- related pseudotachylytes along its fault plane and injected into its hanging wall and footwall. Composite pseudotachylyte zones are up to 1.25 m thick and persists over lateral distances of at least 10's of meters. Pseudotachylyte is common in most thin sections of damaged fault rocks with more than 20% (by volume) of cataclasite. We recognized the presence of original melt using numerous criteria: abundant spherulites in thin sections, injection structures at both the thin-section and outcrop scale, black aphanitic textures, quenched vein margins, variations in microcrystallite textures and/or size with respect to the vein margin, and glassy textures in hand sample. Multiple earthquakes are inferred to produce the layered "stratigraphy" in some exposures of pseudotachylytes. We infer that the West Salton detachment fault formed and <span class="hlt">slipped</span> at low angles because it nearly perfectly reactivates a Cretaceous ductile thrust system at the half km scale and dips between 10 and 45 degrees. The about 30 degree NNE dip of the detachment fault on the north side of Yaqui Ridge is likely steeper than its dip during detachment <span class="hlt">slip</span> because there is local steepening on the flanks of the Yaqui Ridge antiform in a contractional stepover of a crosscutting Quaternary San Felipe dextral fault zone. These relationships indicate a low dip on the detachment</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T43C3014D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T43C3014D"><span id="translatedtitle">Geodetic Measurements of Slow <span class="hlt">Slip</span> and Tremor in Parkfield, CA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delbridge, B. G.; Burgmann, R.; Nadeau, R. M.</p> <p>2015-12-01</p> <p>It has been proposed that large bursts of deep tremor ( >20km depth) near Parkfield, CA are associated with quasi-periodic shear dislocations on the deep extent of the San Andreas Fault. Geodetic studies have shown that slow <span class="hlt">slip</span> accompanies tremor in several subduction zones [e.g. Rogers and Dragert, 2003; Ide et al 2008]. However, prior to this study deformation associated with tremor in a transform fault environment had not been observed despite the ubiquitous presence of tremor and LFEs [Shelly et al, 2007; Nadeau et al 2005] and targeted attempts to observe this deformation [Smith 2009]. In this study we report geodetic measurements of surface strains associated with large tremor swarms that are inferred to be concurrent with slow-<span class="hlt">slip</span> events with moment magnitudes exceeding 5 [Guilhem et al 2012]. The strain rates associated with these events are below the detection level of GPS networks, thus in order to observe this deformation we have utilized two long-baseline laser strainmeters (LSM) located in Cholame, CA. In order to overcome a small signal-to noise-ratio in the strainmeter data, we have stacked the strain records associated with more than 50 large tremor-burst events, each approximately 10 days in duration. The average surface strains associated with these events are on the order of several nanometers and correspond to fault <span class="hlt">slip</span> on the order of 5 millimeters per event (assuming a fault patch extending ~25 km along-strike and ~15km in depth). The measured moment associated with these events is a factor of two smaller than previously proposed based on theoretical estimates [Guilhem et al 2012]. In this study we also explore the deformation associated with a large increase in tremor activity following the August 24, 2014 M6.0 Napa earthquake, the largest observed burst in the Parkfield-Cholame area since the large tremor rate increase associated with the 2004 Parkfield M6 earthquake.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6571597','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6571597"><span id="translatedtitle">Pericollisional strike-<span class="hlt">slip</span> basins in western Cordillera, Canada</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Eisbacher, G.H.</p> <p>1984-04-01</p> <p>The late Mesozoic-Paleogene evolution of the Canadian Cordillera was dominated by accretion of elongate crustal blocks against the North American craton. Geologic and paleomagnetic evidence suggest that these exotic terranes dispersed from volcanic arcs and oceanic platforms and approached North America along anastomosing right-lateral faults with great cumulative displacement. Obduction of oceanic allochthons was followed by transpressive thickening and regional metamorphism of the cratonic margin in the mid-Jurassic. Strike-<span class="hlt">slip</span> motion and emplacement of plutonic rocks continued near relict sutures and reactivated deep faults. Sedimentary basins related to strike-<span class="hlt">slip</span> faults formed by elongation of accreted terranes (''Stikinia'' and ''Wrangellia'') and by shear within the deformed cratonic margin zone (''Rocky Mountain Trench''). Subsidence is reflected by northwest-southeast stretching along pull-apart structures, and by massive influx of turbidites from incipient collision zones and relict are relief. It was interrupted and outlived by rotation of blocks, folding of basin sediments, and vigorous progradation of deltaic-fluvial clastics from rising collision belts. Transition from predominant transtension to prevailing transpression is diachronous from basin to basin. Near the Stikine-Wrangellia collision zone (Bowser basin), it occurred in the Late Jurassic; along the Stikine-Wrangellia border it occurred in the mid to Late Cretaceous. Only small nonmarine basins developed in the Rocky Mountain Trench system, which, in its southern-most part, was closed completely during Paleogene thrust faulting. The strike-<span class="hlt">slip</span> basins of the western Canadian Cordillera were subject to high regional heat flow and also suffered from widespread intrusion of paleogene granitoids. Therefore, they are generally poor oil and gas prospects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002227','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002227"><span id="translatedtitle">Interchange <span class="hlt">Slip</span>-Running Reconnection and Sweeping SEP-Beams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Masson, S.; Aulanier, G.; Pariat, E.; Klein, K.-L.</p> <p>2011-01-01</p> <p>We present a new model to explain how particles, accelerated at a reconnection site that is not magnetically connected to the Earth, could eventually propagate along the well-connected open flux tube. Our model is based on the results of a low-beta resistive magnetohydrodynamics simulation of a three-dimensional line-tied and initially current-free bipole, that is embedded in a non-uniform open potential field. The topology of this configuration is that of an asymmetric coronal null-point, with a closed fan surface and an open outer spine. When driven by slow photospheric shearing motions, field lines, initially fully anchored below the fan dome, reconnect at the null point, and jump to the open magnetic domain. This is the standard interchange mode as sketched and calculated in 2D. The key result in 3D is that, reconnected open field lines located in the vicinity of the outer spine, keep reconnecting continuously, across an open quasi-separatrix layer, as previously identified for non-open-null-point reconnection. The apparent <span class="hlt">slipping</span> motion of these field lines leads to form an extended narrow magnetic flux tube at high altitude. Because of the <span class="hlt">slip</span>-running reconnection, we conjecture that if energetic particles would be travelling through, or be accelerated inside, the diffusion region, they would be successively injected along continuously reconnecting field lines that are connected farther and farther from the spine. At the scale of the full Sun, owing to the super-radial expansion of field lines below 3 solar radius, such energetic particles could easily be injected in field lines <span class="hlt">slipping</span> over significant distances, and could eventually reach the distant flux tube that is well-connected to the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Geomo.244..121I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Geomo.244..121I"><span id="translatedtitle">Experiments on the dynamics and sedimentary products of glacier <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iverson, Neal R.; Zoet, Lucas K.</p> <p>2015-09-01</p> <p>Experimental work in glacial geomorphology is focused almost entirely on processes in the thin shear zone at the beds of sliding glaciers, where ice at its pressure-melting temperature moves over either rigid rock or deformable till. Experiments with rotary shear devices illuminate constitutive behavior there, central to the dynamics of fast-moving glaciers, and provide a foundation for interpreting the sedimentary record of glacier <span class="hlt">slip</span> and associated sediment transport. Results from experiments designed to study ice sliding over a rigid wavy bed, shear deformation of till, and plowing of clasts across the surface of a till bed point to a common conclusion: drag at the bed can decrease with increasing <span class="hlt">slip</span> velocity, thereby concentrating driving stress elsewhere and promoting rapid glacier flow. This rate-weakening behavior at glacier beds is in contrast to the viscous <span class="hlt">slip</span> resistance assumed in ice-sheet models and most efforts to determine distributions of basal drag from glacier surface velocities. Ring-shear experiments in which various basal tills and more idealized materials are sheared to high strains provide quantitative insight into grain size evolution, mixing at contacts between basal tills, microstructure development, particle-fabric development, and development of anisotropy of magnetic susceptibility. Preferred orientations of principal magnetic susceptibilities provide the most dependable and complete description of till shear patterns. When applied to basal tills of the geologic record, magnetic till fabrics measured along thick till sections and calibrated experimentally indicate that deformation of the bed by two lobes of the Laurentide ice sheet was shallow (< 1 m), patchy, and occurred as till progressively accreted. Rates of sediment transport by bed shear were thus significantly less than estimates based on models that invoke deep, pervasive shear of the bed. The lack of an experimental tradition in glacial geomorphology leaves many research</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9439A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9439A"><span id="translatedtitle">Sheath fold development around <span class="hlt">slip</span> surfaces subject to general shear</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adamuszek, Marta; Senderak, Barbara; Dabrowski, Marcin</p> <p>2016-04-01</p> <p>Sheath folds are cone-shaped structures, which typically develop in high-strain shear zones in a variety of geological settings. When observed in the cross-sections perpendicular to the shear direction, sheath folds display characteristic elliptical closed contours. The aspect ratio of the outermost closed contour is commonly used for the classification and quantitative analysis. Alsop and Holdsworth (2006) showed that the outermost aspect ratio observed in the natural sheath folds varies between 1 and 7. Previous work on sheath folds development around <span class="hlt">slip</span> surfaces focused on simple shear deformation (Reber et al., 2013). The aspect ratio developing under such conditions exhibits values larger than the ones observed in nature. Therefore, we investigate sheath fold development around <span class="hlt">slip</span> surfaces under general shear conditions, in which a shortening component acts in the direction parallel to the shearing plane and perpendicular to the simple shear direction. In our models, the out-of-plane shortening is accommodated by 1) extension in the shear direction only or by 2) uniform extension perpendicular to the shortening direction (dilation). On one hand, the pure shear deformation leads to a decrease of the aspect ratio of the outermost closed contour of the developed sheath folds. On the other hand, it also modifies the <span class="hlt">slip</span> surface size and orientation, which promotes development of sheath folds with larger aspect ratios. The numerical simulations show that the latter effect is minor and, for the two tested scenarios, we generate sheath folds with the aspect ratios of the outermost ellipse that favourably compare to the range observed in nature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.T41E..07G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.T41E..07G"><span id="translatedtitle">Determining the causes of fault <span class="hlt">slip</span> rate variability for Northern Apennine thrusts on intermediate timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gunderson, K. L.; Anastasio, D. J.; Pazzaglia, F. J.</p> <p>2012-12-01</p> <p>Documenting fault <span class="hlt">slip</span> rate variability on intermediate (10^4-10^5 yr) timescales is crucial for understanding the process-linkages of short-term (10^1-10^3 yr) and long-term (10^6 yr) patterns of deformation; however, the lack of long records of fault <span class="hlt">slip</span> with 10^4-10^5 yr resolution presents a major barrier to understanding the underlying process responsible for <span class="hlt">slip</span> rate variability at those timescales. Taking advantage of spectacular, continuous exposure of growth strata, we document 10^4-10^5 yr resolution records of unsteady fault <span class="hlt">slip</span> for the past 3.0 myr for three unconnected, shallow blind thrust anticlines growing along the Northern Apennine mountain front, Italy. Fault <span class="hlt">slip</span> rates for these thrusts were determined from progressive restorations of marine and continental growth strata deposited on the anticlinal limbs. These restorations were supported by subsurface corre-lations of the measured growth sections in order to constrain the fold geometries and kin-ematics. Magnetostratigraphy, cyclostratigraphy, cosmogenic radionuclide (CRN) burial dating, and optically stimulated luminescence (OSL) burial dating provided the high-resolution age models for the growth sections. <span class="hlt">Slip</span> histories determined from our pro-gressive restorations indicate that all three of the thrust faults exhibited high-frequency <span class="hlt">slip</span> rate variability. This variability is typically manifest by longer periods of decelerated fault <span class="hlt">slip</span> punctuated by shorter periods of accelerated fault <span class="hlt">slip</span>, typically lasting between 80-200 kyr. During times when <span class="hlt">slip</span> rates were slow, growth strata geometries show ac-celerated <span class="hlt">slip</span> was accommodated by more foreland structures, suggesting <span class="hlt">slip</span> partitioning at 10^4-10^5 yr timescales. This high frequency variability is superimposed on a low frequency <span class="hlt">slip</span> rate variability manifest by an overall deceleration in <span class="hlt">slip</span> on the shallow thrusts since 3.0 myr. Major decelerations in <span class="hlt">slip</span> rates were coincident with the activation of thick-skinned thrusting in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T23E..01R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T23E..01R"><span id="translatedtitle">Earthquake Swarms and Aseismic <span class="hlt">Slip</span> on Transform Faults (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roland, E. C.; McGuire, J. J.; Collins, J. A.</p> <p>2009-12-01</p> <p>Swarms of ordinary earthquakes are common in environments where slow aseismic <span class="hlt">slip</span> events are observed, such as strike-<span class="hlt">slip</span> faults in the Salton Trough and oceanic transform faults. Although in some tectonic settings, the driving mechanisms that cause seismic swarms are well understood (i.e. magma intrusion in regions of volcanism), oceanic transform boundaries currently lack the geophysical data to constrain a distinct driving process. To identify the mechanisms that cause earthquake swarms on strike-<span class="hlt">slip</span> faults, we use relative earthquake locations to quantify the spatial and temporal characteristics of swarms along Southern California and East Pacific Rise transforms. Swarms in these regions exhibit distinctive characteristics, including a relatively narrow range of hypocentral migration velocities, on the order of a kilometer per hour. This rate corresponds to the rupture propagation velocity of shallow creep transients that are sometimes observed geodetically in conjunction with swarms, and is significantly faster than the earthquake migration rates typically associated with fluid diffusion. Each of the swarms we examine also covers a large spatial area relative to its total seismic moment release and fails to decay in time according to standard aftershock scaling laws. Moreover, assuming the Salton Trough faults fail under hydrostatic conditions, the observed migration rate is consistent with laboratory values of the rate-state friction parameter b (0.01). Additionally, we present the first characterization of an oceanic transform fault swarm using data from a local ocean bottom seismometer array. The December 2008 Gofar Transform swarm lasted ~2 days and had at least 12 Mw>4.0 earthquakes. Using the local OBS data, we have detected and located over 5000 microearthquakes that occurred during this episode. This swarm nucleated close to the ridge-transform intersection and rapidly propagated ~10 km towards the center of the transform. The propagation rate (~0</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4794147','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4794147"><span id="translatedtitle">CASTING <span class="hlt">SLIPS</span> FOR FABRICATION OF REFRACTORY METAL WARE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Stoddard, S.D.; Nuckolls, D.E.; Cowan, R.E.</p> <p>1962-09-01</p> <p>A composition is given for <span class="hlt">slip</span> casting tungsten metal. The composition consists essentially of tungsten metal with an average particle size of 0.9 micron, an organic vehicle such as methyl chloroform, o-xylene, n-butyl acetate, isobutyl acetate, and 1, 1, 2, 2-tetrachlorethane, and a suspending agent such as ethyl cellulose, with the approximate ratio of said vehicle to the tungsten metal being 12 cc of a solution containing from 5 to about 20 grams of said ethyl cellulose in 400 cc of said organic vehicle per 100 grams of metal. (AEC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T33E..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T33E..02M"><span id="translatedtitle">The Van Fault, Eastern Turkey: A Preliminary Geological <span class="hlt">Slip</span> Rate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mackenzie, D.; Elliott, J. R.; Altunel, E.; Kurban, Y.; Walker, R. T.; Parsons, B.</p> <p>2014-12-01</p> <p>We present a preliminary quaternary <span class="hlt">slip</span>-rate study on the Van fault, the source of the 2011 Mw7.1 reverse-<span class="hlt">slip</span> earthquake which caused heavy damage to the cities of Van and Ercis, eastern Turkey. From the InSAR solution, we see a strong depth cut-off at 10km depth, above which there was no <span class="hlt">slip</span> on the fault. We have carried out an investigation of the geomorphological expression of the fault in quaternary material, to determine whether the fault reaches the surface and, if so, whether this upper section could fail in an earthquake. On the western segment of the Van fault, we observe quaternary scarps coincident with the surface projection of the fault segment identified by InSAR, which displace quaternary alluvial fan and lake-bed deposits. These are coincident with the observation of fault gouge in quaternary deposits at a road cutting, providing evidence for a fault reaching the surface and suggesting that the upper section is capable of rupturing seismically. We use structure-from-motion photogrammetry, differential GPS and terrestrial LiDAR to determine offsets on two generations of fault scarps, and the creep offsets from the period following the earthquake. Preliminary radiocarbon and OSL dates from two uplifted terrace surfaces allow us to estimate a late quaternary geological <span class="hlt">slip</span>-rate for the fault. Following the GPS and InSAR solution of Dogan et al. 2014 (GRL v41,i7), we also present field evidence and satellite image observations confirming the presence of a splay fault within the northern suburbs of Van city, which experienced creep following the 2011 earthquake. This fault is observed to be particularly evident in the early high resolution satellite imagery from the declassified CORONA missions, highlighting the potential for these datasets in identifying faults in areas now covered by urban sprawl. It remains unclear whether this fault could fail seismically. The fault which failed in 2011 is a north dipping reverse fault, unmapped prior to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUSM.G12A..03C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009AGUSM.G12A..03C&link_type=ABSTRACT"><span id="translatedtitle">Northern Cascadia Episodic Tremor and <span class="hlt">Slip</span>: Cycles Within Cycles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creager, K. C.; Wech, A. G.; Vidale, J. E.</p> <p>2009-05-01</p> <p>Episodic tremor and <span class="hlt">slip</span> (ETS) events, each with geodetically determined moment magnitudes in the mid-6 range, repeat with remarkable regularity every 15 months under the Olympic Peninsula/southern Vancouver Island region. We have automatically searched for non-volcanic tremor in all 5-minute time windows both during the past 4 ETS events and during the inter-ETS period from February, 2007 through April, 2008. Inter- ETS tremor was detected in nearly 3000 windows, which overlap by 50%, so tremor was seen 2% of the time. The catalog of 5-minute tremor locations cluster in time and space into groups we call tremor swarms, revealing 35 inter-ETS tremor swarms. The number of hours of tremor per swarm ranged from about one to 50 hours, totaling 193 hours. The inter-ETS tremor swarms generally locate along the downdip side of the major ETS events, and account for approximately 45% of the time that tremor has been detected during the last entire ETS cycle, which includes the May, 2008 ETS episode. Many of the inter-ETS events are near-carbon copies in duration, spatial extent and propagation direction, as is seen for the larger 15-month-interval events. These 35 inter-ETS swarms plus one major ETS episode follow a power law relationship such that the number of swarms, N, exceeding duration τ is given by N ~ τ-0.6. If we assume that seismic moment is proportional to τ as proposed by Ide et al. [Nature, 2007], we find that the tremor swarms follow a standard Gutenberg-Richter logarithmic frequency-magnitude relation, log10N ~ 10-bMw, with b = - 0.9, which lies in the range for normal earthquake catalogs. Furthermore, the major ETS events fall on the curve defined by the inter-ETS swarms, suggesting that the inter-ETS swarms are just smaller versions of the major 15-month ETS events. Only the largest events coincide with geodetically observed <span class="hlt">slip</span>, suggesting that current geodetic observations may be missing nearly half of the total <span class="hlt">slip</span>. Finally, crude estimates of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFM.S13D..01C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010AGUFM.S13D..01C&link_type=ABSTRACT"><span id="translatedtitle">Slow-<span class="hlt">Slip</span> Scaling Laws Inferred from Cascadia Tremor Swarms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creager, K. C.; Wech, A.; Vidale, J. E.</p> <p>2010-12-01</p> <p>Episodic tremor and <span class="hlt">slip</span> (ETS) events, each with geodetically determined moment magnitudes in the mid-6 range, repeat about every 15 months under the Olympic Peninsula/southern Vancouver Island region. We have applied an automatic waveform envelope cross-correlation and clustering (WECC) algorithm to seven Cascadia-wide subarrays to search for non-volcanic tremor in 5-minute, 50% overlapping, time windows, revealing 70,000 tremor epicenters. The tremor epicenters cluster in time and space into nearly 200 tremor swarms. The number of hours of tremor per swarm ranges from about 1 to 470 hours. The smaller (inter-ETS) tremor swarms generally locate along the downdip side of the larger ETS swarms and occur much more frequently. In northern Washington, which is currently best monitored, the ETS events, as well as the larger inter-ETS tremor swarms initiate downdip and propagate updip. For the large ETS events, tremor swarm duration is proportional to geodetically determined seismic moment. We consider tremor swarms to be a proxy for slow <span class="hlt">slip</span> for the smaller events as well, even though <span class="hlt">slip</span> would be below current geodetic detection thresholds. An interpretation of the observed transition from longer duration, less frequent tremor swarms up dip to smaller more frequent tremor swarms down-dip, in terms of fault strength is the subject of a presentation by Wech. The combined inter-ETS and ETS swarms follow a power law relationship such that the number of swarms, N, exceeding duration τ is given by τ -0.66. If we assume that seismic moment is proportional to τ, as proposed by Ide et al. [Nature, 2007], we find that the tremor swarms follow a standard Gutenberg-Richter logarithmic frequency-magnitude relation, log10 N ≈ -bMw, with b = 1.0, which lies in the range for normal earthquake catalogs. Finally, crude estimates of the spatial dimensions of tremor swarms L suggest that L ≈ τ 1/n where n is between 2 and 3. A value of 2 is consistent with <span class="hlt">slip</span> propagation rates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7275334','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7275334"><span id="translatedtitle">Composite <span class="hlt">slip</span> table of dissimilar materials for damping longitudinal modes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gregory, D.L.; Priddy, T.G.; Smallwood, D.O.; Woodall, T.D.</p> <p>1991-06-18</p> <p>A vibration <span class="hlt">slip</span> table for use in a vibration testing apparatus is disclosed. The tables comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes. 6 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvL.116l7201K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvL.116l7201K"><span id="translatedtitle">Topological Effects on Quantum Phase <span class="hlt">Slips</span> in Superfluid Spin Transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Se Kwon; Tserkovnyak, Yaroslav</p> <p>2016-03-01</p> <p>We theoretically investigate effects of quantum fluctuations on superfluid spin transport through easy-plane quantum antiferromagnetic spin chains in the large-spin limit. Quantum fluctuations result in the decaying spin supercurrent by unwinding the magnetic order parameter within the easy plane, which is referred to as phase <span class="hlt">slips</span>. We show that the topological term in the nonlinear sigma model for the spin chains qualitatively differentiates the decaying rate of the spin supercurrent between the integer versus half-odd-integer spin chains. An experimental setup for a magnetoelectric circuit is proposed, in which the dependence of the decaying rate on constituent spins can be verified by measuring the nonlocal magnetoresistance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1730d0002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1730d0002A"><span id="translatedtitle"><span class="hlt">Slip</span> distribution of the 2010 Mentawai earthquake from GPS observation using least squares inversion method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Awaluddin, Moehammad; Yuwono, Bambang Darmo; Puspita, Yolanda Adya</p> <p>2016-05-01</p> <p>Continuous Global Positioning System (GPS) observations showed significant crustal displacements as a result of the 2010 Mentawai earthquake. The Least Square Inversion method of Mentawai earthquake <span class="hlt">slip</span> distribution from SuGAR observations yielded in an optimum value of <span class="hlt">slip</span> distribution by giving a weight of smoothing constraint and a weight of <span class="hlt">slip</span> value constraint = 0 at the edge of the earthquake rupture area. A maximum coseismic <span class="hlt">slip</span> of the inversion calculation was 1.997 m and concentrated around stations PRKB (Pagai Island). In addition, the values of dip-<span class="hlt">slip</span> direction tend to be more dominant. The seismic moment calculated from the <span class="hlt">slip</span> distribution was 6.89 × 10E+20 Nm, which is equivalent to a magnitude of 7.8.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.429....1V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.429....1V"><span id="translatedtitle">Thermo-mechanical pressurization of experimental faults in cohesive rocks during seismic <span class="hlt">slip</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Violay, M.; Di Toro, G.; Nielsen, S.; Spagnuolo, E.; Burg, J. P.</p> <p>2015-11-01</p> <p>Earthquakes occur because fault friction weakens with increasing <span class="hlt">slip</span> and <span class="hlt">slip</span> rates. Since the <span class="hlt">slipping</span> zones of faults are often fluid-saturated, thermo-mechanical pressurization of pore fluids has been invoked as a mechanism responsible for frictional dynamic weakening, but experimental evidence is lacking. We performed friction experiments (normal stress 25 MPa, maximal <span class="hlt">slip</span>-rate ∼3 ms-1) on cohesive basalt and marble under (1) room-humidity and (2) immersed in liquid water (drained and undrained) conditions. In both rock types and independently of the presence of fluids, up to 80% of frictional weakening was measured in the first 5 cm of <span class="hlt">slip</span>. Modest pressurization-related weakening appears only at later stages of <span class="hlt">slip</span>. Thermo-mechanical pressurization weakening of cohesive rocks can be negligible during earthquakes due to the triggering of more efficient fault lubrication mechanisms (flash heating, frictional melting, etc.).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865726','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865726"><span id="translatedtitle">Method of reducing the green density of a <span class="hlt">slip</span> cast article</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mangels, John A.; Dickie, Ray A.</p> <p>1985-01-01</p> <p>The method disclosed in this specification is one of reducing the green density of an article cast in a <span class="hlt">slip</span> casting operation. The article is cast from a casting <span class="hlt">slip</span> containing silicon metal particles, yttrium containing particles, and a small amount of a fluoride salt which is effective to suppress flocculation of the silicon metal particles by y.sup.+3 ions derived from the yttrium containing particles. The method is characterized by the following step. A small amount of compound which produces a cation which will partly flocculate the particles of silicon metal is added to the casting <span class="hlt">slip</span>. The small amount of this compound is added so that when the casting <span class="hlt">slip</span> is <span class="hlt">slip</span> cast into a casting mold, the partly flocculated particles of silicon will interrupt an otherwise orderly packing of the particles of silicon and particles of yttrium. In this manner, the green density of the <span class="hlt">slip</span> cast article is reduced and the article may be more easily nitrided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70012008','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70012008"><span id="translatedtitle">Variable rates of late Quaternary strike <span class="hlt">slip</span> on the San Jacinto fault zone, southern California.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sharp, R.V.</p> <p>1981-01-01</p> <p>3 strike <span class="hlt">slip</span> displacements of strata with known approximate ages have been measured at 2 locations on the San Jacinto fault zone. Minimum horizontal offset between 5.7 and 8.6km in no more than 0.73Myr NE of Anza indicates 8-12 mm/yr average <span class="hlt">slip</span> rate since late Pleistocene time. Horizontal <span class="hlt">slip</span> of 1.7m has been calculated for the youngest sediment of Lake Cahuilla since its deposition 271- 510 yr BP. The corresponding <span class="hlt">slip</span> rate is 2.8-5.0 mm/yr. Right lateral offset of 10.9m measured on a buried stream channel older than 5060 yr BP but younger than 6820 yr BP yields average <span class="hlt">slip</span> rates for the intermediate time periods, 400 to 6000 yr BP of 1-2 mm/yr. The rates of <span class="hlt">slip</span> suggest a relatively quiescent period from about 4000 BC to about 1600 AD.-from Author</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.G11A0851C&link_type=ABSTRACT','NASAADS'); return false;" href="http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011AGUFM.G11A0851C&link_type=ABSTRACT"><span id="translatedtitle">Coseismic and Postseismic <span class="hlt">slip</span> distribution of the 2007 Solomon Islands Earthquake deduced from A Bayesian Inversion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, T.; Gong, X.</p> <p>2011-12-01</p> <p>In inversion of geodetic data for distribution of fault <span class="hlt">slip</span> minimizing the first or second order derivatives of <span class="hlt">slip</span> across fault plane is generally employed to smooth <span class="hlt">slips</span> of neighboring patches.Smoothing parameter is subjective selected to determine the relative weight placed on fitting data versus smoothing the <span class="hlt">slip</span> distribution.We use the Fully Bayesian Inversion method(Fukuda,2008)to simultaneously estimate the <span class="hlt">slip</span> distribution and smoothing parameter objectively in a Bayesian framework. The distributed <span class="hlt">slips</span>,the posterior probability density function and the smoothing parameter is formulated with Bayes' theorem and sampled with a Markov chain Monte Carlo method. Here We will apply this method to Coseismic and Postseismic displacement data from the 2007 Solomon Islands Earthquake and compare the results of this method with generally favored method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22303844','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22303844"><span id="translatedtitle">Initiation time of near-infrared laser-induced <span class="hlt">slip</span> on the surface of silicon wafers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Choi, Sungho; Jhang, Kyung-Young</p> <p>2014-06-23</p> <p>We have determined the initiation time of laser-induced <span class="hlt">slip</span> on a silicon wafer surface subjected to a near-infrared continuous-wave laser by numerical simulations and experiments. First, numerical analysis was performed based on the heat transfer and thermoelasticity model to calculate the resolved shear stress and the temperature-dependent yield stress. <span class="hlt">Slip</span> initiation time was predicted by finding the time at which the resolved shear stress reached the yield stress. Experimentally, the <span class="hlt">slip</span> initiation time was measured by using a laser scattering technique that collects scattered light from the silicon wafer surface and detects strong scattering when the surface <span class="hlt">slip</span> is initiated. The surface morphology of the silicon wafer surface after laser irradiation was also observed using an optical microscope to confirm the occurrence of <span class="hlt">slip</span>. The measured <span class="hlt">slip</span> initiation times agreed well with the numerical predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2652302','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2652302"><span id="translatedtitle">[Biomechanics of the ankle <span class="hlt">joint</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zwipp, H</p> <p>1989-03-01</p> <p>According to Fick, the tree-dimensional patterns of foot motion are best characterized as jawlike movement. Anatomically and biomechanically, this process represents conjoined, synchronous motion within the three mobile segments of the hindfoot: the ankle <span class="hlt">joint</span>, the posterior subtalar <span class="hlt">joint</span>, and the anterior subtalar <span class="hlt">joint</span>. Foot kinematics can be described more completely if the anterior subtalar <span class="hlt">joint</span> is defined not only as the talocalcaneal navicular <span class="hlt">joint</span>, but as including the calcaneocuboid <span class="hlt">joint</span>, thus representing the transverse <span class="hlt">joint</span> of the tarsus, i.e., the Chopart <span class="hlt">joint</span>. The axes of these three <span class="hlt">joints</span> can be defined precisely. In some parts they represent a screwlike motion, clockwise or counter-clockwise, around the central ligamentous structures (fibulotibial ligament, talocalcaneal interosseous ligament, bifurcate ligament). The individual anatomy and structure of these ligaments provide variations in the degree and direction of foot motion. A precise knowledge of foot kinematics is important in surgical ligament and <span class="hlt">joint</span> reconstruction and in selective foot arthrodeses.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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